tag:blogger.com,1999:blog-9160892212416464442024-03-10T20:13:05.923+01:00Peerdalgwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.comBlogger40125tag:blogger.com,1999:blog-916089221241646444.post-45421032789500957212017-05-09T18:35:00.000+02:002017-05-09T18:35:36.931+02:00Reproducibility in ACM MMSys ConferenceScience is a collective action. A researcher aims at writing papers, which inspire other researchers and eventually help them to also make progresses. We are all part of a large collaborative movement toward a better understanding on how things work. In the case of the Multimedia System community, we deal with animated images, more generally objects that active our senses and more specifically how to encode, transport and process them.<br />
<br />
Despite this evidence, the scientific community is driven by competitive processes, which sometimes lead to secrecy and unwillingness to freely discuss future work. In particular, since exploiting a dataset is a key asset to get papers accepted, the competitive process may conduct researchers to keep a valuable dataset (or a valuable software) to themselves in the fear that other may exploit it better and faster. This (natural) behavior makes the science progress slower than if a collaborative process was in place.<br />
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The “<a href="http://mmsys17.iis.sinica.edu.tw/dataset-track/">open dataset and open software track</a>” is a tentative to fix this issue in the ACM MMSys conference. The track aims at favoring and rewarding researchers who are willing to share. It aims at making science progress faster, still in the competitive process (we accepted only a subset of the submitted datasets for presentation), but with the collaboration in mind.<br />
<br />
The movement for the promotion of reproducible research is ongoing and we are very glad to see that the number of submitted open artifacts has increased since 2011 (the first open dataset track in MMSys history). Previous datasets for MMSys can be found <a href="http://www.mmsys.org/index.php/mmsys-datasets">here</a>. This year, we accepted <a href="http://mmsys17.iis.sinica.edu.tw/accepted-paper-list/#dataset">ten papers, which describe dataset and software</a>.
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<br />
To get one step further, we have embraced the new initiative launched by ACM Digital Library related to <a href="https://www.acm.org/publications/policies/artifact-review-badging">reproducibility badges</a>. In very short, the authors of an accepted paper that let other researchers check the artifact they used can be rewarded by obtaining a badge for their paper. We have implemented badges in two tracks in 2017 ACM MMSys.<br />
<br />
<h3>
Badges for Dataset Track</h3>
In the Open Dataset Track, we have selected the badges "<i>Artifacts Evaluated – Functional</i>", which means that the dataset (and the code) has been tested by reviewers, who had no problem executing, testing, and playing with it, and "<i>Artifacts Available</i>", which means that the authors decided to publicly release their dataset and their code.<br />
<br />
During the selection process, we have acted as usual in academic conference. We have invited a dozen of researchers (who I know are committed to a more reproducible research) to join the committee. Then, we have associated three reviewers to each paper, a paper being a description of a dataset, which is available in a public url. Reviewing an artifact is not the same experience as reviewing an academic paper. To capture a bit more the experience of engaging into the artifact, we have added some unusual questions in the reviewing form, typically:<br />
<b>Relevance and reusability </b>(from 1. Artifact on a niche subject to 4. A key enabler on a hot topic)<br />
<b>Quality of the documentation</b> (from 1. The documentation is below expectations to 3. Crystal-clear)<br />
<b>Artifact behavior</b> (from 1. Bad experience to 3. Everything works well)<br />
<br />
Then, as usual in academic conferences, we selected the dataset papers that got the best appreciation from the reviewers. This year, four of them are related to 360° images and video, the currently hottest topic in multimedia community. Such datasets have been cruelly missing so far, so we are very happy to fill this gap. Two artifacts are related to health, two to transport systems and two to increasingly popular human activity.<br />
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<h3>
Badges for Papers in Research Track</h3>
<div>
In parallel, the organizers of the MMSys conferences have accepted to badge some of the papers that have been accepted in the main "<a href="http://mmsys17.iis.sinica.edu.tw/research-track/">Research Track</a>" of the conference. In this case, the process has been different. First, we waited to know which papers have been accepted. Then, and only then, we have contacted the authors of these accepted papers and proposed them a deal: if you want a badge, you have to first release the artifact in a public website and also to write a more detailed documentation on how to use this artifact. But since we know that this latter instruction could prevent authors to apply for the badge, we authorize those who applied to get extra-pages as Appendix in their papers.</div>
<div>
<br /></div>
<div>
The authors gave us access to a pre-version of the camera-ready version of their papers, then, I contacted another member of the program committee and we both tested the artifact. In that case, we do not have to consider whether the dataset matters for the community or whether it is an enabler. Since the paper has already been accepted, our only mission is to test the dataset and to check if the documentation is enough for any scientist to play with it.</div>
<div>
<br /></div>
<div>
Three papers have followed the process until the end and we are proud to offer them the badges.</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com1tag:blogger.com,1999:blog-916089221241646444.post-49373876757158734612017-01-27T16:06:00.003+01:002017-02-04T11:49:13.324+01:00Attending an MPEG meeting as an academic researcherI recently attended <a href="http://mpeg.chiariglione.org/meetings/117">an MPEG meeting</a> for the first time. I am now used to attending academic conferences (for <a href="http://peerdal.blogspot.fr/2011/08/warm-feedback-from-sigcomm.html">the best</a> and <a href="http://peerdal.blogspot.fr/2011/07/my-disappointing-experience-of.html">the worst</a>) but I had never attended a meeting of a standardization group before. Overall, my feedback is very positive and I will probably embrace a bit more the standard circus in the future (hopefully I will not wait forty years before attending another standard meeting).<br />
<br />
I especially appreciate the commitment of researchers during the MPEG sessions. The attendees are engaged into a "technical/scientific conversation" with the researcher who presents his contribution. It is in no way comparable to the experience of <a href="https://www.youtube.com/watch?v=yL_-1d9OSdk">most academic talks</a>. I identified some of the key differences between a meeting group at MPEG and a standard session in an academic event:<br />
<ul>
<li>The scope of a meeting group is very narrow. For example, I attended the meeting of the ad-hoc group in charge of discussing projections of 360° videos into 2D maps. Every attendee had good reasons to attend this meeting in particular, so free riders were minority. In an academic conference, the Program Chairs tries to schedule the presentations so that papers sharing a similar topic are gathered, but the objectives of these academic papers are often quite different. Instead <b>the contributions during a standard session share the same objectives</b>, which inevitably invite researchers who are experts in the domain to argue about the pros and cons of every contribution, including their owns.</li>
<li>The presentation is not the end, it is the beginning of something wider, which is to eventually contribute to a common (un-authored) document. The chairman is in charge of writing a consensual document after the meeting and a<b> presenter aims at convincing attendees</b> that his contribution is worth being included in this document without reserve. In an academic conference, the motivation of the presenter is to be present so that an accepted paper is not withdrawn from the digital library due to no-show.</li>
<li>When a presenter is invited to introduce his contributions, it is no showtime. He usually stays at his seat and he scrolls over the document that every attendee has previously opened (most people had a look at the contributions beforehand). <b>There is no talk, no slides, no formalism</b>. Only the presenter, his contribution, and engaged attendees. The debate related to a contribution can be two-minutes long or one hour-long. I found it much more lively than well-formatted slide-based talks.</li>
</ul>
<div>
I also appreciate this feeling of being useful as a "public scientist" in a population that is mostly comprised of private researchers. A scientist has various ways to disseminate the knowledge he is supposed to produce with respect to his public funding and salary. Academic conference is the most common way. Some scientists create start-ups. Some scientists develop strong ties with companies and spend most of their energy collaborating in projects. Good reasons to disseminate in standard meetings include:</div>
<div>
<ul>
<li>The contribution from a public academic researcher is (usually) not driven by mercantile private interests. We are supposed to <b>provide something that is closer to The Scientific Truth</b> than what other researchers from competing companies can claim. I understand that one of the missions of a public researcher attending a standard meeting is to ensure that what will eventually become a widely used standard is not an aggregation of patented technologies but rather a scientifically solid and open solution.</li>
<li>Every scientist hopes that the fruit of his research will be eventually exploited, whether indirectly to contribute to a better knowledge or directly by integration into an object that is useful to the society. In applied research topics such as computer science, the academic conferences are not necessarily the best way to convey ideas to the companies that are in capacity to exploit a scientific result. The academic world is mostly fuzzy and closed. <b>A standard group appears as a direct way to enable the exploitation of scientific ideas</b>, without restriction.</li>
</ul>
<div>
Of course, the experience of attending an MPEG meeting also includes annoyances: A lot of time is spent at orchestrating the various standard sub-groups, some guys can ruin a whole meeting by interfering with every presenter, the circus is full of jargon and bizarre usages, which prevent a newcomer to join, political and business games exist ... but the advantages are also numerous (including but not restricted to the above). Overall, the balance is in my opinion positive.</div>
</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-66198541258356984472015-10-02T10:58:00.001+02:002015-10-02T10:58:54.699+02:00Can Multipath Boost the Network Performances of Real-time Media?I would like to emphasize now a paper that deals with multipath networking for video streaming. This paper is:<br />
<i>Varun Singh, Saba Ahsan, and Jörg Ott, “<a href="http://www.netlab.tkk.fi/~varun/2013_MMSYS_Singh_MPRTP.pdf">MPRTP: Multipath Considerations for Real-time Media</a>”, in Proc. 4th ACM Multimedia Systems Conference (MMSys '13), Oslo, Norway, Feb. 2013</i><br />
and it has <a href="https://tools.ietf.org/html/draft-singh-mmusic-mprtp-sdp-extension-04">led to multiple actions in IETF standardization group</a>.<br />
<br />
<div>
There are multiple routes between two hosts in the current Internet. This statement tends to be even truer when considering the flattening Internet topology, where Internet Service Providers (ISPs) have multiple options to reach a distant host. It is also truer with the multiple network interfaces available in the modern mobile devices and the multiple wireless network accesses that co-exist in the urban environment. The question now is about the exploitation of these multiple routes. The network protocols that are in used today stick to the traditional monopath paradigm. Yet, scientists have shown that leveraging multipath can bring many advantages, including better traffic load balancing, higher throughput and more robustness. </div>
<div>
<br /></div>
<div>
This paper, which is already two years old, studies multipath opportunities for the specific case of conversational and interactive communication systems between mobile devices (e.g. Skype). These applications are especially challenging because the traffic between communicating hosts should meet tight real-time bounds. The idea of this paper is to study whether the most widely used network protocol for the applications, namely Real Time Transport Protocol (RTP), can be turned into a multipath protocol. They thus propose a backwards-compatible extension to RTP called Multipath RTP (MPRTP).</div>
<div>
<br /></div>
<div>
In short, this paper presents the MPRTP extension and evaluates its performance in several scenarios. First, the authors comment the main challenges that an extension of RTP protocol must face in order to split a single RTP stream into multiples subflows. Second, the authors present the protocol details as well as the algorithms that are considered to solve these challenges. Third, simulations are conducted to evaluate the performance of the proposal.</div>
<div>
<br /></div>
<div>
Authors point out that a MPRTP protocol should be able to adapt to bandwidth changes on the paths by redistributing the traffic load among them in a smooth way to avoid oscillations. This is especially important in the case of mobile communications where quick capacity changes are common. To guarantee fast adaptation, the authors propose packet-scheduling mechanisms that do not abruptly reallocate traffic among congested and non-congested paths if a path becomes suddenly congested. </div>
<div>
<br /></div>
<div>
Other important issue is the variation on packet inter-arrival time (packet-skew) among the different paths. The fact of having multiple diverse paths make harder to estimate the right buffer size to prevent this issue. To overcome this problem the authors propose an adaptive playout buffer, which individually considers the path skew in each path. They also privilege the selection of paths with similar latencies.</div>
<div>
<br /></div>
<div>
The choice of suitable transmission paths should consider the path characteristics in terms of QoS metrics as losses, latency or capacity. The authors propose several extensions to the RTP protocol, including a new RTP reporting message (where the receiver provides QoS data per sub-flow) and a scheduling algorithm (where the sender uses these reports to decide a traffic distribution among the available paths). </div>
<div>
<br /></div>
<div>
All the aforementioned extensions are always designed to be backwards compatibility, i.e. traditional RTP hosts can interoperate with hosts equipped with MPRTP extensions in single-path scenarios. </div>
<div>
<br /></div>
<div>
An exhaustive battery of simulations is conducted to evaluate the MPRTP performance in a broad range of scenarios: (i) path properties (losses, delays, and capacities) vary along time; (ii) paths share a common bottleneck, and (iii) MPRTP is deployed over mobile terminals using WLAN and/or 3G paths. These evaluations show that (1) the dynamic MPRTP performance is not far from the static performance for single and multipath cases, (2) MPRTP successfully offloads traffic from congested paths to the other ones keeping some proportional fairness among them, and (3) on lossy links multipath is more robust and produces fewer losses with respect to single path.</div>
<div>
<br /></div>
<div>
Overall, this paper addresses a significant problem (how to make a real-time UDP-based protocol multipath) with a comprehensive study. It is one of the first attempts to exploit multipath functionalities in the framework of multimedia communications, and especially with tight real time limitations. This paper thus perfectly completes the works that have been done by the network community on multipath TCP protocols. That being said, many problems related to multipath multimedia protocols are still open. Among others, let us cite rate-adaptive streaming and multiview video in the context of multipath.</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-63354778061202912752015-09-19T17:52:00.000+02:002015-09-19T17:52:16.867+02:00Understanding an Exciting New Feature of HEVC: TilesAs an editor of the <a href="http://committees.comsoc.org/mmc/rletters.asp">IEEE R-letter</a>, I write every now and then some short "letters" (one page long easy-going text) about a recent research article that I found especially interesting. I think it is appropriate to have also these letters put in this blog. Thus, I will publish them also here.<br />
<br />
The paper I'd like to emphasize is:<br />
<i>Kiran Misra, Andrew Segall, Michael Horowitz, Shilin Xu, Arild Fuldseth, and Minhua Zhou, “<a href="http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6547985">An Overview of Tiles in HEVC</a>”, IEEE Journal of Selected Topics in Signal Processing, Vol. 7, No 6, December 2013</i><br />
<br />
<div class="MsoNormal" style="text-align: justify;">
The High Efficiency Video Coding
(HEVC) standard significantly improves coding efficiency (gains reported as 50%
when compared to the state-of-the-art MPEG-4 AVC H264), and thus is expected to
become popular despite the increase in computational complexity. HEVC also
provides various new features, which can be exploited to improve the delivery
of multimedia systems. Among them, the concept of tiles is in my opinion a promising
novelty that is worth attention. The paper "An Overview of Tiles in
HEVC" provides an excellent introduction to this concept.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The goal of a video decoder
(respectively encoder) is to convert a video bit-stream (respectively the
original sequence of arrays of pixel values) into a sequence of arrays of pixel
values (respectively a bit-stream). The main idea that is now adopted in video
compression is the hierarchical structure of video stream data. The bit-stream
is cut into independent Group of Pictures (GOP), each GOP being cut into
frames, which have temporal dependencies with regards to their types: Intra
(I), Predicted (P) or Bidirectional (B) pictures. Finally, each frame is cut
into independent sets of macroblocks, called <i style="mso-bidi-font-style: normal;">slices</i> in the previous encoders. <o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The novelty brought by HEVC is
the concept of <i style="mso-bidi-font-style: normal;">tile</i>, which is at the
same "level" as slice in the hierarchical structure of video stream
data. <o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The motivations for both slices
and tiles are, at least, twofold: error concealment and parallel computing.
First, having an independently parsable unit within a frame can break the
propagation of errors. Indeed, due to the causal dependency between frames, an
error in a frame can make the decoder unable to process a significant portion
of the frames occurring after the loss event. Slices and tiles limit, at least
from a spatial perspective, the propagation of an error on the whole frame.
Second, the complexity of recent video and the requirements of high-speed CPU
speed (which unfortunately requires power and generates heat) can be partially
addressed by parallelizing the decoding computation task across multiples
computing units, regardless of whether these are cores in many-cores
architectures or computing units in Graphics Processing Units (GPUs). The
independency of slides and tiles is expected to facilitate the implementation
of video decoder on parallel architectures.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
Unfortunately, the concept of
slices suffers in practice from serious weaknesses, which tiles are expected to
fix. <o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
In the paper, the authors
introduce the main differences between tiles and slices, which are two concepts
that, at a first glance, can be confused. They focus on the motivation for
parallel computation.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The first part of the paper
explains in details the main principles between both approaches, in particular
the fact that tiles are aligned with the boundaries of Coded Tree Blocks (CTD),
which provides more flexibility to the partitioning. This brings several benefits:
a tile is more compact, which leads to a better correlation between pixels
within a tile when compared to the correlation between pixels in a slice. Tiles
also require less headers, among other advantages.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The authors also introduce the
known constraints to be taken into account when one wants to use tiles today.
The whole Section 3 is about the tile proposal in HEVC, and the main challenges
to be addressed for a wide adoption. Next, the authors present some examples
when tiles are useful. Both parts are written so that somebody being just
familiar with the concepts can understand both the limitations behind the
concept of tiles and how these weaknesses have been addressed in practice.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
<div class="MsoNormal" style="text-align: justify;">
The last part of the paper, in
Section 5, deals with some experiments, which demonstrate the efficacy of HEVC
for lightweight bit-streams and parallel architectures. At first authors assess
the parallelization and the sensibility of network parameters, including the
Maximum Transmission Unit (MTU), on the performances of slices versus tiles. They
finally measure the performances of stream rewriting for both approaches.<o:p></o:p></div>
<div class="MsoNormal" style="text-align: justify;">
<br /></div>
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In short, the paper shows that
tiles appear to be more efficient than slices on a number of aspects. The paper
proposes a rigorous, in-depth, introduction of the main advantages of tiles.
This can foster research on the integration of tiles into next-generation
multimedia delivery systems.<b><span style="mso-ansi-language: FR; mso-fareast-font-family: 宋体;"> <span lang="FR"><o:p></o:p></span></span></b></div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com1tag:blogger.com,1999:blog-916089221241646444.post-45989941138106473302015-09-02T15:47:00.002+02:002015-09-02T17:01:41.621+02:00Uploading innovative engineers: 15 years remaining Four years ago, I wrote <a href="http://peerdal.blogspot.fr/2011/01/computer-science-and-engineers-bad.html">an outrageous post</a> about how "un-geek" are French engineers <i>in average</i>. Since 2011, many things have changed in France: c<a href="http://www.swaven.com/en/2015/05/06/reading-writing-counting-and-coding/">ode is expected to be (soon) taught in elementary schools</a>, <a href="http://www.economie.gouv.fr/files/20140306_100_developpeurs_francais_marquants.pdf">successful geek entrepreneurs are in the spotlight</a>, <a href="http://www.42.fr/">geek-ish schools</a> and <a href="https://wiki.hackerspaces.org/France">co-working hacker spaces</a> flourish, ... It will take time, but, hopefully, France in 2025 will be geek-friendly. <b>Now, what about innovation?</b><br />
<br />
Entrepreneurship has become a cause nationale in France, with <a href="http://www.rudebaguette.com/2014/06/16/paris-need-numa/">a lot of initiatives</a> and <a href="http://www.koudetat.co/">announcements</a>. Analysts try to decipher the structural problems regarding innovation in France, in particular an <a href="https://medium.com/welcome-to-thefamily/qu-est-ce-qu-un-%C3%A9cosyst%C3%A8me-entrepreneurial-86e7644147f3">excellent study</a> (in french) about innovation "ecosystems" was released yesterday. Everything said in this article is 100% true... but it misses a point: <b>how "un-innovative" are the French higher-educated people <i>in average</i>.</b><br />
<br />
As a teacher in <a href="http://www.telecom-bretagne.eu/index.php?lang=en_GB">a high-education engineering school</a>, I have headed an "Innovation & Entrepreneurship" course for 8 years (with some success stories <a href="https://www.sentimy.com/">here</a> and <a href="https://t.co/UnSaArRVZl">there</a>). <b>Every student must follow this course</b>. From my experience of teaching this innovation course to around 180 students every year, I can just recall that the average higher-educated students (usually coming from <a href="https://en.wikipedia.org/wiki/Classe_pr%C3%A9paratoire_aux_grandes_%C3%A9coles">Classes Préparatoires</a>) struggle to:<br />
<ul>
<li><b>Deal with uncertainties.</b> The most brilliant scientific students are those who excel at finding solutions to problems. But what about when there is no clearly identified problem? And what about when any solution to a problem has its pros and cons? Most of the students who would have <i>not</i> enrolled in an Entrepreneurship program if they had the choice are very uncomfortable with uncertainties. They are the right targets for innovation mindset re-formatting.</li>
<li><b>Convince</b>. The French education system does not include any training in talking, debating, arguing, more generally communication skills. When every US kid should defend a point in a <a href="https://en.wikipedia.org/wiki/Science_fair">science fair</a>, the same age French kids are taught how to raise the hand before talking, the quieter the better. Oral debates barely exist at french school. As a matter of fact, it is frequent that students give their very first "public" talk when they are 20 years old. Teaching the art of pitching is necessary for <i>every</i> student.</li>
<li><b>Accept being a failure and a rebel</b>. This is especially true during brainstorming and creativity sessions where it is common that somebody, say Jo, suggests a high-risk or out-of-the-box idea but almost immediately the fear of being judged makes Jo himself overturn his own damned idea. I'd love to put Jo in more creativity training sessions so that he becomes self-confident enough.</li>
</ul>
The percentage of engineers who have these three core competencies (an innovation-friendly mindset) in 2015 is as low as the percentage of engineers who had a geek-friendly mindset in 2011. Solutions like super-hyped incubators or <a href="http://www.bpifrance.fr/Investors-Center"> state-owned VC</a>s are right but they are similar to providing xDSL broadband connections to geeks in 2000s. It is cool for the happy fews, but it does not change the mindset of the others.<br />
<br />
In my opinion, a successful innovation ecosystem is such that everybody in the society (especially every higher-educated worker) has an innovation-friendly mindset. Everybody means here people who do not aim to become entrepreneur and even those who are not directly related to innovation. No society can afford that a majority of higher-educated people have not developed in particular these three key competencies at school. The structural reasons behind this failure <i>for average higher-educated workers</i> are in my opinion more critical than an imperfect innovative ecosystem <i>for a tiny fraction of innovators</i>. Indeed, the lack of inclinations toward uncertainties, communication skills and rebel-attitude is a transmissible disease for any innovative ecosystem.<br />
<div>
<br /></div>
<div>
It is the mission of teachers in high-education institutions to fight the stigmata of twenty years of un-innovative mindset formatting. The special "Entrepreneurship" programs that are commonly offered in other higher-education institutions (or in <a href="http://www.france-universite-numerique.fr/entrepreneuriat.html">online courses</a>) do not contribute to this mission because these programs enroll volunteering students who have already overcome their innovation-related mindset limitations. These students are not the right target. To set up a profoundly innovation-friendly ecosystem in 2030, we have to train <i>all</i> higher-educated students <i>now</i> so that innovation will be pervasive in the society, especially at schools, in community groups and in the traditional companies. Hopefully, the ecosystem will then be friendly to entrepreneurs... </div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-85929076562008415262015-03-24T18:21:00.000+01:002015-03-24T18:21:10.367+01:00Ten years as an academic scientist: preamble of my HdRHere is the preamble of my <a href="http://en.wikipedia.org/wiki/Habilitation">HdR</a>, which I will defend on April the 7th 2015 at <a href="https://www.telecom-bretagne.eu/about/rennes-campus/">Rennes</a>.<br />
<br />
I defended my PhD thesis ten years ago. At that time, my research
domains included peer-to-peer systems, mobile ad-hoc networks and
large-scale virtual worlds. Today, these topics hardly get any
attention from the academic world. Although most papers published in
the early 2000s advocated that centralized systems would never scale,
today's most popular services, which are used by billions of users,
rely on a centralized architecture powered by data-centers. In the
meantime, the open virtual worlds based on 3D graphical representation
(e.g. Second Life) fell short of users while social networks based on
static text-based web pages (e.g. Twitter and Facebook) have exploded.
I do not want to blame myself for having worked in areas that have not
proved to be as critical as they were supposed to be. Instead, I would
like to emphasize that I work in an ever-changing area, which is
highly sensitive to the development of new technologies (e.g. big data
middleware), of new hardware (e.g. smartphone), and of new social
trends (e.g. user-generated content).<br />
<br />
I envy the scientists who are able to precisely describe a multi-year
research plan, and to stick to it. I am not one of them. But I am not
ashamed to admit that my research activity is mostly driven by
short-term intuition and opportunities and that the process of
academic funding directly impacts my work. Indeed, despite all of the
above, I have built a research work, which I retrospectively find
consistent. And more importantly, I have been relatively successful in
advising PhD students and managing post-docs, all of them having
become better scientists to some extents.<br />
<br />
In very short, I have developed during the past ten years a more solid
expertise in (i) theoretical aspects of optimization algorithms, (ii)
multimedia streaming, and (iii) Internet architecture. I have applied
these triple expertise to a specific set of applications: massive
multimedia interactive services. I provide in this manuscript an
overview of the activities that have been developed under my lead
since 2006. It is a subset of selected studies, which are in my
opinion the most representative of my core activity.<br />
<br />
I hope you will have as much fun reading this document as I had
writing it.
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-9798939969666758872014-11-07T16:51:00.001+01:002014-11-07T16:51:52.644+01:00A Dataset for Cloud Live Rate-Adaptive VideoThere is an audience for non-professional video "broadcasters", like gamers, online courses teachers and witnesses of public events. To meet this demand, live streaming service providers such as <a href="http://www.ustream.tv/">ustream</a>, <a href="http://new.livestream.com/">livestream</a>, <a href="http://www.twitch.tv/">twitch</a> or <a href="http://www.dailymotion.com/live">dailymotion</a> have to find a solution for the delivery of thousands of good quality live streams to millions of viewers who consume video on a wide range of devices (from smartphone to HDTV). Yet, in current live streaming services, the video is encoded on the computer of the broadcaster and streamed to the data-center of the service provider, which in most cases chooses to simply forward the video it get from the broadcaster. The problem is that many viewers cannot properly watch the streams due to mismatches between encoding video parameters (i.e. video rate and resolution) and features of viewers’ connections and devices (i.e. connection bandwidth and device display). <br /><br /><div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGI0WeQ5j5dx5gcFFcEGsQcr_1e443PUuylf1o7hqwYV8I_S4FJ2JheHmUf4rksMgUgSk7MOUeKmCTDBxc8EtZsZSSsy82D-lRcIb2wR2Yl9PYz_dHCO9yjW1ZU3KS6IGmjwF0JHNy04/s1600/Screen+Shot+2014-11-07+at+16.36.18.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGI0WeQ5j5dx5gcFFcEGsQcr_1e443PUuylf1o7hqwYV8I_S4FJ2JheHmUf4rksMgUgSk7MOUeKmCTDBxc8EtZsZSSsy82D-lRcIb2wR2Yl9PYz_dHCO9yjW1ZU3KS6IGmjwF0JHNy04/s1600/Screen+Shot+2014-11-07+at+16.36.18.png" width="236" /></a></div>
<div>
To address this issue, adaptive streaming working along with cloud computing could be the answer. Whereas adaptive streaming allows managing the diversity of end-viewers requirements by encoding several video representations at different rates and resolutions, cloud computing provides the CPU resources to live transcode all these alternate representations from the broadcaster-prepared raw video.<br /><br />It is well known that the QoE of an end-viewer watching a stream depends on the encoded video and the parameters values used in the transcoding. But, in this new scenario in the cloud, we also need to consider the transcoding CPU requirements. In the “cloud video” era, the selection of video encoding parameters should take into account not only the client (for the QoE), but also the data-center (for the allocated CPU). To set the video transcoding parameters, the cloud video service provider should know the relations among transcoding parameters, CPU resources and end-viewers QoE, ideally for any kind of video encoded on the broadcaster side.<br /><br />We would like to announce the publication of a dataset containing CPU and QoE measurements corresponding to an extensive battery of transcoding operations in <a href="http://dash.ipv6.enstb.fr/dataset/transcoding/">http://dash.ipv6.enstb.fr/dataset/transcoding/</a> with the purpose of contributing to research in this topic. Most of the credits for this work (and so this post) have to be given to <a href="http://perso.telecom-bretagne.eu/ramonapariciopardo/">Ramon Aparicio-Pardo</a>.</div>
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To elaborate the dataset, we have used four
types of video content, four resolutions (from 224p up to 1080p) and bit rates
values ranging from 100 kbps up to 3000 kbps. Initially, we have encoded each
of the four video streams into 78 different combinations of rates and
resolutions, emulating the encoding operations at the broadcaster side. Then, we
transcode each of these <i>broadcaster-prepared
</i>videos into all the representations with lower resolutions and bit rates
values than the original one. The overall number of these operations,
representing the <i>cloud</i>-<i>transcoding</i>, was 12168. For each one of
these operations, we have measured the CPU cycles required to generate the
transcoded representation and we have estimated the end-viewers’ satisfaction
using the Peak Signal to Noise Ratio (PSNR) score). We depict a basic sketch of
these operations for one specific case where the broadcaster encoded its raw
video with 720p resolution at 2.25 Mbps and we transcode it into a 360p video
at 1.6Mbps.<o:p></o:p></div>
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<span style="mso-ansi-language: EN-US;">We give below an appetizer of how these CPU
cycles and satisfaction decibels vary with transcoding parameters. They show some
examples of the kind of results that you will find in the dataset, here a <i style="mso-bidi-font-style: normal;">broadcaster-prepared </i>video<i style="mso-bidi-font-style: normal;"> </i>of type “movie,” 1080p resolution and
encoded at 2750 kbps. If you wonder how the rest of figures look like, 558
curves and their corresponding 12168 measurements of cycles of hard CPU work
and decibels of viewers’ satisfaction are waiting for you in </span><span lang="FR"><span lang="FR" style="mso-ansi-language: EN-US;"><span lang="FR"><a href="http://dash.ipv6.enstb.fr/dataset/transcoding/">http://dash.ipv6.enstb.fr/dataset/transcoding/</a></span></span></span><span class="MsoHyperlink"><span style="mso-ansi-language: EN-US;"> <o:p></o:p></span></span></div>
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<!-- Blogger automated replacement: "https://images-blogger-opensocial.googleusercontent.com/gadgets/proxy?url=http%3A%2F%2F3.bp.blogspot.com%2F-tFFx8MG2vsc%2FVFznItd0HYI%2FAAAAAAAAAvM%2FDFL8GPtXB3Y%2Fs1600%2FScreen%252BShot%252B2014-11-07%252Bat%252B16.36.18.png&container=blogger&gadget=a&rewriteMime=image%2F*" with "https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGI0WeQ5j5dx5gcFFcEGsQcr_1e443PUuylf1o7hqwYV8I_S4FJ2JheHmUf4rksMgUgSk7MOUeKmCTDBxc8EtZsZSSsy82D-lRcIb2wR2Yl9PYz_dHCO9yjW1ZU3KS6IGmjwF0JHNy04/s1600/Screen+Shot+2014-11-07+at+16.36.18.png" --><!-- Blogger automated replacement: "https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGI0WeQ5j5dx5gcFFcEGsQcr_1e443PUuylf1o7hqwYV8I_S4FJ2JheHmUf4rksMgUgSk7MOUeKmCTDBxc8EtZsZSSsy82D-lRcIb2wR2Yl9PYz_dHCO9yjW1ZU3KS6IGmjwF0JHNy04/s1600/Screen+Shot+2014-11-07+at+16.36.18.png" with "https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGI0WeQ5j5dx5gcFFcEGsQcr_1e443PUuylf1o7hqwYV8I_S4FJ2JheHmUf4rksMgUgSk7MOUeKmCTDBxc8EtZsZSSsy82D-lRcIb2wR2Yl9PYz_dHCO9yjW1ZU3KS6IGmjwF0JHNy04/s1600/Screen+Shot+2014-11-07+at+16.36.18.png" -->gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-37666068051438126412014-10-13T17:43:00.001+02:002014-10-15T09:29:59.236+02:00Toward a new public higher education system<a href="http://peerdal.blogspot.fr/2014/10/the-misconceptions-behind-french-fun.html">My previous post</a> was quite harsh about the way the French government addresses the MOOC phenomenon. I would like now to be more constructive (and also to demonstrate that I am not only a moaner). So, basically, what would I do if I was French ministry of Higher Education! In short:<br />
<ul>
<li><b>I'd shut down FUN</b>. To be competitive, such project requires investment an order of magnitude greater than the planned fundings. When the objective is to attract tens thousands of students, there is no room for small players. </li>
<li><b>I'd stop fundings through call for proposals</b>. These calls grant people who know how to write proposals and who, in the best case, release results years later. Moreover, and most importantly, these calls do not give the sense of responsibility to university managers. French higher education institutions have to learn how to promote their best professors and to make them "MOOC-able" instead of begging to the government as if "make a MOOC" was a right.</li>
<li><b>I'd massively invest on French-friendly start-ups</b>. The focus should be on three main domains where the position of France is today weak: an European-scale portal, tools for scalable learning, online student evaluation. The investment can be leaded by a structure such as BPI France.</li>
</ul>
In the following, I give my personal analysis of the context. I first decompose the traditional functions of a higher education institution, and analyze the challenges.<br />
<ul>
<li><b>Define the topic of the courses</b>. In France, the institutions conceive curriculum, which are then checked by academic accrediting agencies like <a href="http://www.abet.org/accreditation/">ABET</a> in US, or <a href="http://www.cti-commission.fr/-About-us-">CTI</a> and <a href="http://www.aeres-evaluation.com/">AERES</a> in France. Shortly put, the curriculums target young people (named students) and aim at developing their employability. Several courses form a consistent curriculum. As for the MOOCs, students are mainly workers, with a large diversity of motivations. The course is a unit, which should be independent. The topics are focused. It is thus quite different, but not fundamentally challenging.</li>
<li><b>Select the students</b>. This is the main asset of the <i>Grandes Ecoles.</i> However, MOOC are (expectedly) scalable, so you can teach an unlimited number of students. The question is no more to <i>filter</i> the best students <i>before</i> the course. The aim now is to have the right audience for the course: as many students as possible, with a high motivation for the topic and the right background. As said in my previous post, portals like Coursera are far better than any French higher education institution. </li>
<script src="//www.google.com/trends/embed.js?hl=en-US&q=/m/02zd460,+coursera,+/m/01v0m4,+/m/05zl0&date=1/2011+46m&cmpt=q&content=1&cid=TIMESERIES_GRAPH_0&export=5&w=500&h=330" type="text/javascript"></script>
<li><b>Build the course</b>. Every MOOC creators agree that building a scalable online course is quite different from a traditional course for a small, on-site, population. MOOCs require <a href="http://garage21.org/2014/09/08/les-metiers-mooc/">new categories of workers</a>. But the role of the teacher is still prominent. So far, the teachers have worked in traditional higher education institutions.</li>
<li><b>Deliver the course</b>. A building full of classrooms is useless. What is needed is a great, scalable, full-featured learning management tool. Moreover, you need a competitive team of developers to implement online exercices which have an added value and increase the student experience. Here, again, I don't think that any traditional french higher education institution can compete in providing such tool. Only a team of excellent super-committed software developers can do it.</li>
<li><b>Assist students during their learning experience</b>. The challenge of MOOCs is to provide the same kind of assistance as for a traditional course with one professor and a dozen of students, although the number of students is in the order of thousands. The power of community is the lever.</li>
<li><b>Evaluate the students</b>. When students are spread all over the world, it is impossible to organize exams the usual way. Companies like <a href="http://www.proctoru.com/">ProctorU</a> have developed offers, where either exam rooms are available anywhere in the planet, or specific, secured, online tools allow anybody to be monitored as if she was on-site.</li>
</ul>
In the traditional model, all these functions are fulfilled by higher education institutions. In the new model related to MOOC, I foresee that traditional institutions will be outperformed by start-ups on a subset of functions: create a portal to attract students, develop a scalable learning platform, and evaluate students worldwide. These functions require strong skills in software development, in empowering a community of open-source developers, in promotional activities and marketing, in worldwide staff management, in agile development, in reliable online infrastructure, in website design. My claim is that neither universities nor public structures have any of the above skills.<br />
<br />
Instead, I suggest to give a special mission to <a href="http://www.bpifrance.fr/Bpifrance/Notre-mission">BPI France</a> to make sure that funding goes to the most brilliant European start-ups related to education, in particular on the aforementioned functions (attract students worldwide, develop scalable learning platforms, evaluate students). By investing on European SMEs, the emergence of a champion is possible. And if the public force is one of the main investors, it may also ensure some of the "public missions" (e.g. almost free access to knowledge). Examples of such brilliant European start-ups include <a href="http://fr.openclassrooms.com/">OpenClassroom</a>, <a href="https://iversity.org/en/pages/about">Iversity</a> and <a href="https://www.futurelearn.com/about">FutureLearn</a>.<br />
<br />
On their side, the traditional French higher education institutions have to evolve. I like the analogy between MOOC and scientific books. Not all professors write books. Not all institutions ask their teaching staff to write books. Excellent professors (experts in some area, extremely brilliant as teachers) attract editors because the books they may write can become a success. It is thus up to the institutions to decide whether they should promote their excellent professors so that they may be detected by editors. Being "MOOC-able" is now a criteria for hiring professors in EPFL according to its director. This is the kind of shift French institutions have also to embrace.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com1tag:blogger.com,1999:blog-916089221241646444.post-84351257488502774512014-10-08T10:03:00.000+02:002014-10-15T09:44:32.225+02:00The misconceptions behind the French FUN-MOOC portalIt is frequent that bloggers start their controversial posts with a disclaimer about how their personal opinion is not necessarily endorsed by their employers. In the case of this post, it is one step further: I am afraid that my opinion is the opposite of my employers' one.<br />
<br />
I would like to talk about MOOC, you know, this innovation that may disrupt the higher education. My colleagues and I have been quite active in this area for the past couple of years, <a href="http://peerdal.blogspot.fr/2013/05/i-made-mooc-and-i-survived.html">with a MOOC open on Spring 2013</a>, and a contribution to <a href="https://www.fun-mooc.fr/courses/MinesTelecom/04003/Trimestre_1_2014/info">two successful</a> <a href="https://www.fun-mooc.fr/courses/MinesTelecom/04002/Trimestre_1_2014/info">MOOCs</a>.<br />
<br />
One year ago, the French government decided to be pushy in this area, and thus to build from scratch a website named <a href="http://fr.wikipedia.org/wiki/France_Universit%C3%A9_Num%C3%A9rique">France Université Numérique</a> (sorry no english translation for the wikipedia page yet), which aims at gathering MOOC in french from French higher education institutions in a free online portal. I summarize below some of the profound, symptomatic, critical misconceptions about what is innovation and Internet that this project demonstrates:<br />
<ul>
<li>This public (state-funded) project emerges although some private French start-ups (e.g. <a href="http://fr.openclassrooms.com/">OpenClassrooms</a> and <a href="http://www.unow.fr/">Unow</a>) were just kick-starting in the MOOC area. For the set of young entrepreneurs who were trying to gain reputations and to convince universities and Grandes Ecoles to join the MOOC movement, the arrival of such a competitor changed the game. FUN is a de facto incumbent since higher education entities are also funded by government. FUN is a public non-profit action, so it is completely free without need of any business model. These start-up have managed to find their place in a new ecosystem nonetheless, but, in my opinion, FUN-MOOC did not help. When it will be time to cry about the lack of "French Coursera" (like most cry today about the lack of French Google), we shall not forget that the government actually prevents the raise of such a possible French success story by entering the market like a bull in a china shop. </li>
<li>I am always sad when I realize that our political leaders still consider in 2014 that it is trivial to build a popular 24/7 Internet full-featured portal, and that it is trivial to manage a sophisticated professional online tool such as a massive, social, online course platform. It seems that the numerous failures of the public French websites have been quickly forgotten. FUN-MOOC was, and it is still now, a complete disaster. Typically, the portal has been shut down during two<i> entire </i>days in September 2014 for software upgrades. As can be expected from projects that are managed by people who know very few about the Internet and software, numerous shocking mistakes have been done, e.g. considering INRIA and a so-called <a href="http://fr.wikipedia.org/wiki/Entreprise_de_services_du_num%C3%A9rique">SSII</a> as a good team for the development of a software, and forking from the main open source online course platform project although the developer community was vivid and active.</li>
<li>The branding does not look like an important matter for those who initiated this project. The acronym is FUN (I guess there is a couple of references <a href="https://www.google.com/search?q=fun">when you type FUN on google</a>). The full name is French oriented, which is good in France and in some places in Africa, but is bad when you consider any other part of the world. It is hard to know whether it is a consequence, but we have almost <a href="https://www.fun-mooc.fr/courses/MinesTelecom/04001S02/Trimestre_3_2014/26d9ddb6e5704d0d9690da0bd0010371/">no Swiss, nor Quebec students registered in our courses in french</a>. More generally, if one wants to build a popular website, the branding is key. It looks like the government did the same mistake as the creator of lescopainsdavant. When you compete versus Coursera, Udacity and EdX, a FUN name is not a gift.</li>
</ul>
<div>
I was very doubtful about this initiative, and <a href="https://www.linkedin.com/groups/Allez-on-se-l%C3%A2che-on-5044954.S.5796573893615439872">I publicly claimed it</a>. I told some friends that the government would try to shut down FUN-MOOC in less than two years when the MOOC bubble would go down and when our political leaders would realize that FUN-MOOC is expensive and not necessarily good for the economic sector as a whole. Well, I was wrong, it took them only nine months to realize. Unfortunately, we don't have our happy end yet. Indeed, the government asks whether some higher education entities would be happy to maintain FUN-MOOC on behalf of the government. The very sad point about it is that a consortium of various French entities (including Institut Mines-Telecom) is a candidate. Let me continue the misconception list:</div>
<div>
<ul>
<li>When it is time for innovation in general, a consortium of bureaucratic state-funded education entities is not the right vehicle. Exploring new business models, breaking the rules and embracing disruption are not in the DNA of public French universities, are they?</li>
<li>A consortium of universities is no better than a government for managing a 24/7 full-featured online portal nor a sophisticated professional online tool. Universities struggle to have decent websites and learning software. I don't see any reason for a success in such a project, whatever the funding.</li>
<li>The business model is, well, it is complicated, but with high probability it will be to complain that the government is not giving enough money for FUN-MOOC to work properly.</li>
<li>The management is typical of the crazy French higher education system, with consortium of consortiums of entities that do not like each other, a probable series of rebranding operations just to be sure that everybody gets lost, weird processes where nobody really knows who is in charge of what, especially about critical points like the promotion of the portal and the development of new features, and, most of all, the promises of hours-long meetings.</li>
</ul>
<div>
It seems to me that all the main mistakes that a higher education ministry and a set of public universities can do are being done. Hopefully, some will eventually succeed in stoping this crazy bureaucratic counter-productive process. I failed.</div>
</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com4tag:blogger.com,1999:blog-916089221241646444.post-65984234462597604842013-10-16T17:33:00.000+02:002014-07-28T15:19:05.453+02:00What encoding parameters for video representations in adaptive streaming?<a href="http://blog.eltrovemo.com/1218/mpeg-dash-ecosystem-status/">Dynamic Adaptive Streaming (DASH)</a> is a technology that has been implemented and deployed although the scientific literature was inexistent. Simply put, the server offers several <b>representations</b> of the same video ; clients can choose the representation that best fit their capacities. Since 2008, many researchers have deciphered the global behavior of client-based adaptive mechanisms. However, one key piece of the theoretical cake is still missing: what is the optimal set of video representations the server should offer?<br />
<br />
<div class="p1">
As far as we know, there are no commonly accepted rules on how to choose the encoding parameters of each representation (resolution and rate). Providers typically use somewhat arbitrary rules of thumb or follow manufacturers’ <b>recommendations</b> (e.g. <a href="http://goo.gl/fJIwC">Apple</a> and <a href="http://www.microsoft.com/en-us/download/details.aspx?id=17678">Microsoft</a>), which do not take into account neither the nature of video streams, nor the user base characteristics. These parameters can however have a large influence on both user QoE and delivery cost.</div>
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With fellow researchers from EPFL (<a href="http://lts4.epfl.ch/page-88027-en.html">Laura</a> and <a href="http://lts4.epfl.ch/frossard">Pascal</a>), we have recently investigated this topic from an optimization standpoint. The objective is to maximize the average user satisfaction. We formulated an optimization problem with the following inputs, which any content provider hopefully knows:</div>
<div class="p1">
</div>
<ul>
<li>for each video in the catalog, <i>the expected QoE of users for any rate-resolution</i>. This can be easily obtained from a rate-distorsion curve computed on a sample of the video on every resolution.</li>
<li>for each video in the catalog, <i>the characteristics of the population of viewers</i>. I mean here the client device (tablet, TV, smartphone, ...) and the available bandwidth of the network connection (xDSL, fiber, 3G, ...). This requires an "a priori" knowledge of the viewer population, but we guess it can be obtained from previous statistics. </li>
<li><i>the minimum ratio of viewers that must be served</i>, i.e. the users who actually get a video, even at a relatively bad quality.</li>
<li>for the delivery part, <i>the overall bandwidth budget that can be provisioned</i>. Typically, we consider that the cost of the CDN should be bounded, and so the overall used bandwidth is bounded too.</li>
<li>finally, <i>the total number of representations that we want to encode</i>. The idea here is to limit the storage and encoding costs, and to avoid huge, hard-to-administer Manifest files.</li>
</ul>
<div>
We solved the problem on a set of synthetic configurations (the above inputs). Our goal was twofold: (i) measure the "performances" of recommended set of representations, and (ii) provide <b>guidelines</b> for content providers.<br />
<br />
About the former goal, our observation is that recommended sets are not that bad in terms of average QoE but, for a given expected quality, the number of representations in these recommended sets is almost twice the number of representations in the optimal solutions. In other words, the average QoE is obtained at the price of more video representations, which mean more encoders, more storage, more delivery bandwidth in the CDN infrastructure, and more complexity in the management. We also showed that these recommended sets perform poorly for more specific configurations. For instance, <a href="http://www.twitch.tv/">a content provider specialized in live e-sport videos</a> or <a href="https://vine.co/">a content provider targeting mobile phones</a> must absolutely <b>not</b> follow recommendations.<br />
<br />
We also derive from our analysis a series of guidelines. Some of them may be obvious, but it is never bad to recall obvious things, especially when nobody seems to follow them.<br />
<ol>
<li><b>How many representations per video?</b> The repartition of representations among videos needs to be content-aware. Put emphasis on the videos that are the more complex to encode (e.g. sports)</li>
<li><b>For a given video, how many representations per resolution?</b> It mainly follows the distribution of devices in user population. Put a slight emphasis on highest resolutions.</li>
<li><b>How to decide bit-rates for representations in a given resolution?</b> The higher is the resolution, the wider should be the range of rates. Put emphasis on lower rates.</li>
<li><b>How to save CDN bandwidth?</b> Reduce the range of rates for representations in a resolution. Reduce the number of representations at high resolution.</li>
</ol>
These first results are just preliminary tests. We have plenty of new topics to explore. Stay tuned!<br />
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<div>
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<br />gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-10932853394764164942013-07-21T22:59:00.002+02:002013-07-23T21:52:27.937+02:00We forced students to enroll in a MOOC... and they liked it!We made <a href="https://courses.mooc.telecom-bretagne.eu/course/introductions-aux-reseaux-cellulaires/">a MOOC</a>, and it was <a href="http://peerdal.blogspot.fr/2013/05/i-made-mooc-and-i-survived.html">all but easy in backstage</a>. This MOOC was integrated in the regular curriculum of <a href="http://www.telecom-bretagne.eu/index.php?lang=en_GB">Telecom Bretagne</a> students, so we kind of <i>forced</i> students to follow a MOOC. These students were neither volunteers nor MOOC-enthusiasts.<br />
<br />
We just got feedbacks (i) from the traditional survey, which is performed by our administration every semester, and (ii) from <a href="http://fr.surveymonkey.com/s/TBGWW7B">a specific survey</a> we conducted. Here is a short analysis.<br />
<br />
<span style="color: #0b5394; font-size: large;">Students enjoyed videos!</span><br />
Students were unanimously positive for the MOOC although they were unanimously negative for other distant learning experiments, for example watching videos captured during a regular lecture (even with several cameras), or lectures through visioconference. As far as I know, it is the first time that Telecom Bretagne students are positive about a distant learning experiment.<br />
<br />
To be honest, we did not expect feedbacks at this level of enthusiasm, especially with regard to the troubles we experienced during the course preparation. Typically, we received suggestions of replacing all regular lectures by MOOC videos. Some students enrolled in another (traditional) course about cellular networks did not attend that course because they preferred attending the MOOC instead. Less passionate but more useful, students were satisfied with the pace and the clarity of videos. They admitted they have worked more than expected overall but they did not especially complain about it. And students who are not French natives said that their level in French was sufficient to watch the video.<br />
<br />
Of course, these results have to be validated by another experiment, but they confirm the high level of acceptance for KhanAcademy-like short videos.<br />
<br />
<span style="color: #0b5394; font-size: large;">Quizz matters, peer-reviewing does not</span><br />
An MOOC is expected to be something more complex than just a bunch of videos. What we did in this MOOC was nothing spectacular: some quizz after video, a forum, some assignments, and a peer-reviewed system, which allowed students to review the assignments from other students. At the end of the day, how useful are these beyond-videos learning tools?<br />
<br />
From our survey, quizz are what matters the most. The main purpose of these quizz is to offer students a way to check whether they were attentive during a video. In short, if you cannot answer the quizz, then you should probably watch the video again. Intuitively, quizz are not magical learning tools. But, think twice about it and recall when you were student. If you were sure the teacher would ask you a question in say five minutes, you would certainly be very focused on the teacher during these five minutes. Now think about a teacher asking you a question <i>every</i> five minutes! Today's quizz are very simple, but this positive feedback may encourage us to enhance quizz.<br />
<br />
On the contrary, peer-reviewing has not been appreciated. Students did not find useful to review the assignments from other students, and they found even less useful to receive the reviews about their work from other anonymous students. I am disappointed because I had a lot of hopes in this learning tool, which is the most "connectivist" tool we implemented. Well, we have to work further on it!<br />
<br />
<span style="color: #0b5394; font-size: large;">It is not easy to take notes while watching videos</span><br />
When we interviewed (very informally) students, a recurring object of worries was the notes. How to take notes although the videos is played? A video is not a lecture. It is focused and it does not include any time out. Almost any sentence matters and requires a note. Moreover, you cannot only listen, you must watch, at least a bit.<br />
<br />
Students suffered from being unable to follow the videos and to take notes simultaneously. Some of them paused the video regularly. Some other played the video twice, one first time to get the global picture and a second one to take selected notes. From our survey, students playing videos more than twice are rare (less than 10%).<br />
<br />
This feedback emphasizes that students have to acquire new methods in order to follow such video-based courses. Somehow students who have followed our MOOC got some specific skills, which will be useful if they have to follow other MOOC in their life (which is highly probable). Should we include some courses about how to follow a MOOC in the curriculum?<br />
<br />
<span style="color: #0b5394; font-size: large;">Multiple experiences are possible</span><br />
There is not one unique way to follow a MOOC. We got confirmation if you had doubts about it.<br />
<br />
We booked some classrooms with computers and headspeakers in the regular schedule. Some students told us they appreciated. They used to attend these "free" hours because it was for them a guarantee to maintain a regular learning pace. Some others of course worked by bursts, watching several hours of videos in one night when they got assignments. Overall, I like this freedom, which calls for unconstrained MOOC schedules.<br />
<br />
Finally, a group of students told us they used to watch the video together. I can only imagine beers, chips, a TV screen... and MOOC videos! (debates should be lively for the quizz) This way of experiencing MOOC videos is great since it allows students to discuss the learning material. When we give a lecture in amphitheater, we usually ban in-class chats because we assume most of it is not related to the lecture. But chats among students can be useful. This experience is also opening questions about next-generation campuses: dedicated tiny classrooms equipped with a TV screen are options to consider.<br />
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<br />gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com3tag:blogger.com,1999:blog-916089221241646444.post-85959369561437071102013-05-27T11:09:00.000+02:002013-07-08T09:47:40.175+02:00I made a MOOC and I survived!Xavier Lagrange, Alexander Pelov and I made <a href="https://courses.mooc.telecom-bretagne.eu/course/introductions-aux-reseaux-cellulaires/">a MOOC introducing Cellular Networks</a>!<br />
<br />
It is supposed to be a 20-hours course for students having a minimum background on networks. It attracted around 350 students, including 35 students from <a href="http://www.telecom-bretagne.eu/">my institution</a> for which this course is part of the curriculum.<br />
<br />
I do not discuss here our motivations to create a MOOC and the way students have experienced it. I focus on the teacher's standpoint when making this MOOC.<br />
<br />
We decided to make our own MOOC from scratch without using external products (except YouTube to host video). In other words, we did not use third-party companies like Coursera and Udacity, which host content, advertise it, ensure hotline for technical troubles, and so on.<br />
<br />
<span class="Apple-style-span" style="color: #0b5394; font-size: large;">Time Spent</span><br />
On a very rough estimation, we spent 240 hours on this MOOC, including:<br />
<ul>
<li>20 hours preparing the pedagogical material. This part is actually enjoyable for teachers. To transform classic 3 hours-long lectures into 7-minutes-long to-the-point videos (+ quizz) is actually a nice challenge. Though, there is room to do more: we did not change much our exercises. Moreover the only collaborative tool we experimented is peer reviewing for homework. In other words, the transition to <a href="http://tipes.wordpress.com/2012/06/12/differents-types-de-moocs/">c-MOOC</a> would require more time.</li>
<li><i>x</i> hours interacting with students. Since our MOOC was not that crowded, <i>x</i> was close to epsilon but I guess there should be some formulas linking teacher interaction time and number of students.</li>
<li>30 hours installing and testing the MOOC platform. We chose <a href="http://openmooc.org/">OpenMOOC</a> because it was the only available, viable, open-source platform at that time. It is an overall good basis but it is relatively hard to install for people who are not familiar with server administration. Moreover, statistics modules are very incomplete. But, still, OpenMOOC is OK, it provides basic functionalities and the teacher interface is friendly.</li>
<li>180 hours generating the video of courses, including:</li>
<ul>
<li>Warm-up: it is all but easy to write on a tablet while watching a camera, to master all recording elements, to feel comfortable, to find the right tone and the right pace. For each teacher, the first tries recording videos were disastrous.</li>
<li>Recording: we made a lot of errors, for example to speak during twenty minutes with microphones off. Even when everything runs perfectly, speaking for such video is totally different from lectures. Overall, 2 minutes of recorded videos ended up into 1 minute of video that can be actually exploited.</li>
<li>Producing: we discovered how to use a studio software. With <a href="http://www.telestream.net/screenflow/">nowadays tools</a>, it took us in average 10 minutes to deal with each recorded minute, so 20 minutes per each finally online minutes of video. And we had around 90 videos with average 6 minutes. </li>
</ul>
<li>5 hours advertising. We were not affiliated with a well-known platform, so we needed to attract people (despite the aridness of the topic). Clearly, we did not do enough.</li>
</ul>
<div>
<br /></div>
<div>
<span class="Apple-style-span" style="color: #0b5394; font-size: large;">Process</span></div>
<div>
The teacher should first decide how to cut a full course into <i>units</i>, each unit being four to ten <i>chunks</i>, each chunk being a 7-minutes long video. We opted for the format that has been popularized by <a href="http://www.khanacademy.org/">Khan Academy</a>. This format is now widely used all over the platforms: the background is (almost) empty, the teacher speaks in the background, we sometimes see his/her face, and the most important point is that he/she writes on the slide when he/she speaks.<br />
<br />
Our process was to first create the <i>target slides</i>, i.e. what we want to have at the end of the video. Then, we only kept what is actually hard to draw in real time, for example a hexagonal ceiling. This is the <i>background slide</i>. The goal of the video is to start with the background slide, to write on it, and to finish with something that is close to the target slides. During the recording, the target slides were displayed behind the camera so that the teacher does not forget anything (and look at the camera).<br />
<br />
We decided to not use a prompter because we wanted to keep it as natural as possible. We did not write the discourse in advance, but Xavier and Alex master the topic so well that they did not need it. Note that it is also possible to pause during the recording so that teacher can take time to think to the next sentences. It is also possible to repeat something in a better way when the previous sentences were not totally satisfactorily. These pauses and repeated sentences can be cut afterwards.<br />
<br />
To generate the first videos, we used software, cams and microphones that we found in our shelves. We were able to generate some videos but <a href="https://www.youtube.com/watch?v=mdGGdhriJi0">the overall quality was borderline</a>. Then, we got some extra fundings and we were able to get professional materials and to build our own studio. <a href="https://www.youtube.com/watch?v=HEHJYSnOBbE">The quality is far better</a>. Our studio includes a<a href="http://www.wacom.com/products/pen-displays/cintiq/cintiq-24hd"> tablet</a>, a powerful Mac with enough hard-disk (we needed around 1 Terabytes for this MOOC only), some wireless microphones, and a semi-professionnal camera.<br />
<br />
<span class="Apple-style-span" style="color: #0b5394; font-size: large;">Stuff I Would Have Made In a Different Way</span><br />
I put here miscellaneous thoughts:<br />
<ul>
<li>We would have chosen a sexier title. In our case, it would have been appropriate to include a buzzword like LTE, LTE-advanced or femtocells in the title. We identified three ways to attract a large population of students: </li>
<ul>
<li>The MOOC is affiliated with a top-ranked university, which knows how to advertise, or with a highly-visible platform like Coursera. These websites attract millions of visitors, so any course can enroll thousands of students. It is possible that these enrolled people are less committed to complete the course though;</li>
<li>The MOOC is about a very trendy topic, say quantum computing, software-defined networks or any other buzzword. It has to be reminded that the majority of "MOOC students" are professionals who want to keep in touch with new topics they heard about; </li>
<li>You make the buzz about your MOOC. We spent only 5 hours advertising and we are not professional. Press and web buzz campaigns is a way. It is also possible to convince fellows from other universities to make their students enroll your MOOC.</li>
</ul>
<li>We would have found a better video format. Let's be honest: without a dedicated team, it is a indecently long and fastidious to create Khan Academy-like videos. We went too much when it was about videos. Compare <a href="http://www.youtube.com/watch?v=6Wawm1F_TEA">this video</a> and <a href="http://www.youtube.com/watch?v=2SxwsE1AflU">this other video</a>. It took us 20 minutes to produce each minute of the former video while it took us only 4 minutes for the latter. Is it worthwhile? Based on our experience, it is probably possible to divide by at least 3 the overall time spent on video.</li>
</ul>
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<span class="Apple-style-span" style="color: #0b5394; font-size: large;">Conclusion</span></div>
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Overall, it was a great experience. We learned a lot about the potentials of such online courses and we had a lot of fun playing with videos. We developed a lot of nice ideas for the next MOOC, and we significantly improved the process of video recording and editing.</div>
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But it was also a huge investment. Xavier told me that making this MOOC was as demanding as writing a book. I often compare books with MOOCs when I have to explain our motivations to do MOOC. Both are knowledge, both are supposed to be done by experts, both target a wide population… it seems that both require very committed authors.</div>
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gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com6tag:blogger.com,1999:blog-916089221241646444.post-40482577517256384122013-01-29T15:56:00.001+01:002013-01-30T11:12:11.045+01:00MOOC and Grandes Ecoles: surfing the tsunamiIn North-America, the development of Massive Online Open Courses (MOOC) is seen as a panacea, a way to fix <a href="http://www.purdue.edu/president/messages/2013/130118-MED-letter.pdf">some of the multiple flaws of the higher education system</a>. From a buzz standpoint, this belief culminated when <a href="http://www.nytimes.com/2012/05/04/opinion/brooks-the-campus-tsunami.html">Stanford president claimed</a> "<i>there is a tsunami coming.</i>" The debate is less lively in France. Yet, the tsunami would have good chances to affect the French higher education as well.<br />
An originality of the French higher education system is the prominent position of <a href="http://en.wikipedia.org/wiki/Grandes_%C3%A9coles">Grandes Ecoles</a>. I am working in one of them, <a href="http://www.telecom-bretagne.eu/index.php?lang=en_GB">Telecom Bretagne</a>, which is part of the <a href="http://en.wikipedia.org/wiki/Institut_Mines-T%C3%A9l%C3%A9com">Institut Mines-Telecom</a>.<br />
<br />
<h3>
Risks</h3>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
My first claim is that Grandes Ecoles are in danger. Reasons include:</div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
</div>
<ul>
<li><b>Grandes Ecoles have to face new competitors.</b> The emergence of start-ups like Udacity and Coursera has transformed Grandes Ecoles into an oligopoly of dinosaurs. Grandes Ecoles are used to the competition among themselves. In short Grandes Ecoles share the "market" of producing highly-qualified professional students, which is a market that universities do not address accurately. The reality is that all Grandes Ecoles have approximately the same offer: roughly same size, same structure, same diploma, same normalized courses. The aforementioned new competitors are start-ups with limitless ambition and nothing to lose. They have almost no administrative cost, they do not waste money in research, they can fail and revise their strategies on a month basis, they can address students worldwide. These start-ups actually shuffle the cards.</li>
<li><b>Grandes Ecoles' main asset is diploma in a certification world.</b> Companies like <a href="http://en.wikipedia.org/wiki/Cisco_Career_Certifications">Cisco</a> and <a href="http://en.wikipedia.org/wiki/Microsoft_Certified_Professional">Microsoft</a> have developed <a href="http://en.wikipedia.org/wiki/Professional_certification_(Computer_technology)">professional certification systems</a> for years. Students become super-expert in a given specialty and receive a certificate, which demonstrate their employability. Though, these efforts have never disrupted the high-education system. By offering individual courses, MOOCs challenge again the notion of degree, which is commonly seen as a set of certifications (including many useless ones). The companies that are not convinced by the degree system will find in MOOC a great opportunity to revisit their Human Resources processes and to bypass Grandes Ecoles.</li>
<li><b>Grandes Ecoles are not attractive for the targeted students.</b> Grandes Ecoles are very attractive to bright French students, but MOOC's target population is all over the world. Unfortunately, Grandes Ecoles are visible neither in international rankings, nor on the web. Grandes Ecoles have also not demonstrated strong relationships with companies that really matter to students (especially Apple and Google). Finally, the perspective to live in France during three years for courses that are not all considered as worthwhile is a key weakness.</li>
</ul>
<h3>
Opportunities</h3>
My second claim is that Grandes Ecoles are in an excellent position. Here is a selection of advantages.<br />
<ul>
<li><b>Grandes Ecoles are adaptive.</b> These are small institutions, which are directed by managers having a long experience in industry. Grandes Ecoles are far more flexible and reactive than any other institutions. They can re-organize, they can develop strategical plans, they can reinvent themselves and they can embrace new ways to fulfill their missions without delay. MOOC is an opportunity for Grandes Ecoles to develop new businesses and to improve their offers.</li>
<li><b>Grandes Ecoles excel on what complement MOOCs.</b> It is a common understanding that MOOC is about knowledge. A set of MOOCs is not enough to turn students into smart workers. Many other competencies should be developed, including team-working, communication skills, and social networking among classmates. Grandes Ecoles focus on these aspects through project-based pedagogy, personalized and tutored curriculum, campuses designed as learning centers, and good placement in attractive companies. In Europe, Grandes Ecoles excel in all these aspects and find here a way to differentiate in a positive way from other institutions. Grandes Ecoles can leverage MOOC rather than suffering from MOOC.</li>
<li><b>Grandes Ecoles have already a strong relationship with companies.</b> Curricula are typically discussed with companies on a regular basis such that learning matches the requirements of targeted employers. Grandes Ecoles also have developed programs for "continuing education" in relationships with Human Resources. Thus Grandes Ecoles are used to the act of selling learning programs elaborated by their faculties in a business perspective. The diploma is a virtual good that has made sense since the XIXth century, often challenged but never surpassed because companies like employees who are more than just a super-expert in a couple of areas.</li>
</ul>
The next couple of years will be key for Grandes Ecoles. It will be very interesting to observe what the executives of Grandes Ecoles will do. Undoubtedly, executives will have to be brave if they want to transform their institutions. They have to make Grandes Ecoles able to compete at the planet scale, to leverage their assets, to catch up emerging trends, and to focus on what is really making Grandes Ecoles unique learning places. Strong decisions will have to be taken. For example: giving up with academic research to re-focus on education, cutting faculty jobs in departments that have no activities in core scientific domains, developing business related to buying/selling MOOCs...gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com2tag:blogger.com,1999:blog-916089221241646444.post-58287505057461174512013-01-29T02:12:00.001+01:002013-01-29T17:03:02.132+01:00This increasingly frustrating peer review processAcademic people barely share their bad personal experiences related to peer reviewing. But everybody has papers rejected in conferences… and these decisions sometimes generate legitimate frustration since they seem to be due to some "random bad outcome from this plain old flawed reviewing process". On my side, I have the feeling that reviewing process is getting worse and worse. <a href="http://youinfinitesnake.blogspot.ca/2011/08/whats-wrong-with-computer-science.html">I am not alone. </a>Following <a href="http://simplystatistics.org/post/26977029850/my-worst-recent-experience-with-peer-review">this example</a>, I describe below some recent reject notifications that illustrate some of these flaws. And I propose some ways to fix them.<br />
<div>
<br /></div>
<div>
<span class="Apple-style-span" style="font-size: large;"><b>The un-rebutted rebuttal</b></span><br />
In 2012, both ICME and Sigcomm conferences introduced a rebuttal in the reviewing process. I know a lot of scientists who call for such rebuttal process. Unfortunately, my experience of rebuttal was absolutely disastrous on both cases. It is interesting to note that these conferences are definitely not in the same league.</div>
<div>
<br /></div>
For ICME, I suspect one of the reviewer to be a weak graduate student: he gave us a strong reject based on his claim that one of the four proofs of the paper was wrong on a specific equation. Unfortunately his mathematical statement was false. This bad review was the perfect case where a rebuttal can help to fix a clear misunderstanding and a wrong analysis. We spent a significant part of our rebuttal trying to politely fix the mathematical error of this reviewer. Hélas, we received our negative notification. The reviewers did not change any word of their review. And the meta-reviewer gave us this unforgivable remark: "<i>The authors thinks that the reviewer 2 misunderstand the work in this paper. From the comment, the reviewer should be an expert in this field"</i>. This meta-reviewer does not understand rebuttal, does he?
<br />
<div>
<br /></div>
<div>
For Sigcomm, one of the reviewers claimed that our 14-pages long proposal can be done by tweaking another existing system. More precisely, the reviewer "<i><b>believes</b> that with simple changes to your problem, one can use the [other] system to tackle it, <b>probably</b> by just changing the utility function.</i>" We knew well this said other system… and we double-checked again. No, there is no way, both papers share some words, but they are like apples and oranges. However, this was the main strong drawback raised by this reviewer, so we were full of hope that we could make our case by carefully explaining the differences with this previous work. Hélas, triple hélas, one month later, the reviews arrived, unchanged.</div>
<div>
<br /></div>
<div>
In both cases, rebuttals came back without any changes, even when we highlighted some major wrong analysis.</div>
<div>
<br /></div>
<div>
<b>Proposal</b>: I don't believe much in rebuttal, but at least this proposal deserves a better implementation. In particular, reviewers must address the remarks that authors made about their reviews.<br />
<br />
<br />
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<b><span class="Apple-style-span" style="font-size: large;">The anonymous reviewer</span></b></div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
We submitted a reasonable paper to a special issue of IEEE Transactions on Multimedia. One reviewer was vaguely positive, one reviewer was vaguely negative, and then came the third reviewer… This guy did not find any positive comment to do. It looks like none of these 14 pages was worth anything. Moreover, all his negative comments were excessively aggressive and mostly based on wrong self-proclaimed facts. The review was just a piece of harsh and assertive remarks. This paper was not a Nobel Prize, for sure, but it was a honest, valid paper, with a motivation based on a series of observations from well-established measurement systems, some theoretical developments, and a non-trivial simulation. Maybe not worth a publication in this journal, but <i>why so much hate?</i></div>
</div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<br /></div>
</div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
One well-known issue of peer reviewing in computer science is <a href="http://cacm.acm.org/magazines/2010/7/95070-hypercriticality/fulltext">the excessive harshness of reviewers</a>, often young scientists, comfortably protected by the anonymity. In the excellent "<a href="http://www.agu.org/pubs/authors/pdf/PeerReview_Guide.pdf">Guide for Peer Reviewing</a>", it is said that, as far as possible, the first paragraph of a review should summarize the goals, approaches and conclusions of the paper (including positive assessments) while the second paragraph should provide a conceptual overview of the contribution.</div>
</div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<br /></div>
</div>
<div>
<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
<b>Proposal</b>: Some reviewers would be less assertive, and less aggressive if there were any probability that their identity would be revealed. Why not having a "<i>out of the k reviews you do for a conference, one of them will be randomly chosen to be de-anonymized.</i>" Or a "<i>one out of ten reviews are de-anonymized</i>".</div>
</div>
</div>
<div>
<br /></div>
<span class="Apple-style-span" style="font-size: large;"><b>The no-room-for-cold-topics program chair</b></span><br />
We sent a P2P paper to Globecom, although it is well-known that <a href="http://iqua.ece.toronto.edu/~bli/papers/bli-risefall.pdf">P2P is now a very cold topic</a>. We received two clearly positive reviews, and one review slightly more negative in the grades, but with comments like "<i>The addressed problem is relevant, the paper is well-written and technically solid</i>". Globecom has a 37% acceptance ratio, but despite these grades, our paper has been rejected. My first reject at Globecom.<br />
<div>
<br /></div>
<div>
I asked some additional explanations to the TPC chair, and he kindly answered that "<i>in the confidential comments, there was a voiced concern about novelty</i>". In other words, it seems that anonymity is not enough for reviewers, they still require an even more anonymous place to assess the judgements they are the less proud of. According to the guide of peer reviewing, the "confidential comments" are just a bad habit, which affects the overall transparency of the reviewing process. On my side, I never use it, and I don't find any convincing point for using it.</div>
<div>
<br /></div>
<div>
<b>Proposal</b>: ban the confidential comments.</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com2tag:blogger.com,1999:blog-916089221241646444.post-11803195500005041392012-12-05T23:59:00.000+01:002012-12-06T00:01:17.572+01:00Brewing storm on cloud gaming. Are CDNs the saviors?<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif;"><span id="internal-source-marker_0.4453676799312234"><span id="internal-source-marker_0.4453676799312234"><span style="background-color: transparent; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Cloud gaming has the potential to become a revolution in the way games are developed and distributed.</span></span></span><span style="background-color: transparent; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Instead of requiring end-users to buy powerful computers to play modern games, cloud gaming performs the game computation remotely with the resulting output streamed as a video back to the end-users. Cloud gaming is thus expected to meet the demand of both gamers (who want platform independence), and game developers (who want to reduce their development cost and to gain flexibility in game updating). The enthusiasm has however been severely chilled when <a href="http://www.mercurynews.com/business/ci_21735364/onlive-assets-palo-alto-gaming-company-were-sold-4-million">the main actor in the area, namely OnLive, ran out of money</a>.</span></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif; white-space: pre-wrap;"><br /></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif;"><span class="Apple-style-span" style="white-space: pre-wrap;">This debacle is not surprising. M</span><span style="background-color: transparent; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">any of cloud computing’s core design tenets conflict with cloud gaming.</span><span style="background-color: transparent; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: transparent; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Cloud providers only offer general purpose computing resources that are located in a relatively small number of large data-centers. Unfortunately, these architectural decisions are in conflict with the needs of cloud gaming, which are interactive (hence highly latency-sensitive), and require specialized hardware resources, such as GPU and fast memory. </span><span class="Apple-style-span" style="white-space: pre-wrap;">Furthermore, many cloud data-center locations are chosen to minimize cooling and electricity costs, rather than to minimize latency to end-users.</span></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;"><br /></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;">Despite these drawbacks, <a href="http://venturebeat.com/2012/09/21/after-onlive-heres-why-nvidia-believes-cloud-gaming-is-just-getting-started-interview/">many analysts still believe in cloud gaming</a>. In a near future, the number of users served by physical machines should grow, data-centers should include GPUs, game engine should be re-designed… OnLive may just have been too early.</span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;"><br /></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif;"><span class="Apple-style-span" style="white-space: pre-wrap;">Still, the question of the number and the location of data-centers remains. </span>Past studies have found that players begin to notice a delay of 100 ms. However, <a href="http://snsl.cs.ntou.edu.tw/pubs/detail/2013mmsys.php">at least 60 ms of this latency should be attributed to playout and processing delay</a>. Therefore, 40 ms is the threshold network latency that begins to appreciably affect user experience. </span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif;"><br /></span></div>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;">In <a href="http://enstb.org/~gsimon/Resources/edgecloud.pdf">a recent academic paper</a>, which was presented during the <a href="http://netgames2012.lip6.fr/">ACM Netgames conference</a>, we have performed a large-scale measurement study to determine :</span></div>
<ul>
<li style="text-align: justify;"><span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;"><b>the percentage of population that can be served with today's cloud infrastructure</b>. With EC2 infrastructure, less than 40% of population can play highly interactive games (network response time 40 ms), and only two third of population can play the least demanding games (network response time 80 ms). See Figure below.</span></li>
</ul>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><img height="269" src="https://lh5.googleusercontent.com/l2e1wsPkr40NkZ6B6ZmlRiiym3xqDMF8ykVykOT8938ATLX9e-ocFvcc6Qm41RpBGPq9kY5TG8vWWHQzL8gs9zlatkz5e-FaNGbuEe5S1o3nXAH_4huv" style="margin-left: auto; margin-right: auto;" width="320" /></span></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif; font-size: small;">Population covered by EC2 cloud infrastructure</span></td></tr>
</tbody></table>
<div style="background-color: transparent; text-align: center;">
<span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><b id="internal-source-marker_0.9331599865108728" style="font-weight: normal;"></b></span></div>
</div>
<ul>
<li style="text-align: justify;"><span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;"><b>the number of data-centers that are required to have a decent population coverage</b>. Unfortunately even if 20 data-centers are deployed, less than half of population would have a network response time of 40 ms.</span></li>
<li style="text-align: justify;"><span class="Apple-style-span" style="font-family: Verdana, sans-serif; white-space: pre-wrap;"><b>the gain of using a CDN infrastructure</b>. They are significant. Today's CDN servers do not host GPU, and they are not designed to serve a very small number of users (<a href="http://www.amd.com/us/press-releases/Pages/amd-invests-ciinow-2012sep11.aspx">only 8 users per server with state-of-the-art technologies</a>). But who knows what will be CDN next strategical moves? Our study shows that embracing cloud gaming is a very good idea for CDNs, isn't it?</span></li>
</ul>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8L-LkKN8S8PD10W-mu3Ukf1ouu5FvTv5GOCOXnspYMVw_jw646uYx2GqVYugVd3hzijoPvhp49Q8ohxUG4r98_AecIhaCbZ6zNZya7rHUVkWgrStDLkKCe9c65IlztjysotG3dXQLVTY/s1600/Screen+shot+2012-12-05+at+11.44.28+PM.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif;"><img border="0" height="296" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8L-LkKN8S8PD10W-mu3Ukf1ouu5FvTv5GOCOXnspYMVw_jw646uYx2GqVYugVd3hzijoPvhp49Q8ohxUG4r98_AecIhaCbZ6zNZya7rHUVkWgrStDLkKCe9c65IlztjysotG3dXQLVTY/s400/Screen+shot+2012-12-05+at+11.44.28+PM.png" width="400" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span class="Apple-style-span" style="font-family: Times, 'Times New Roman', serif; font-size: small;">Population covered if EC2 is augmented with CDN smart edges</span></td></tr>
</tbody></table>
<div style="text-align: justify;">
<span class="Apple-style-span" style="font-family: Arial, Helvetica, sans-serif;"><span class="Apple-style-span" style="white-space: pre-wrap;"><br /></span></span></div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com2tag:blogger.com,1999:blog-916089221241646444.post-13037343596737970482012-10-30T16:25:00.001+01:002012-10-30T16:30:24.406+01:00Lessons learned at UWaterloo (2nd part): research organizationHere is the second post about my experience at University of Waterloo. After the <a href="http://peerdal.blogspot.fr/2012/10/lessons-learned-at-uwaterloo-first-part.html">ode to the co-operation education program</a>, here is another positive observation related to research organization. All in one, I have the feeling that the time spent in meetings by researchers in North-America is four times less than their European counterparts. I wish statistics could support this claim. Why so? I identified at least two explanations.<br />
<br />
Firstly the <b>structures fundamentally differ between American and European research institutions</b>. It might sound like a caricature, but Americans promote individual successes while Europeans build large corporations. A research department in an American university is an aggregation of independent researchers, who manage their own team of students and research fellows with their own budget, and who develop their own line of research. In Europe, senior researchers should gather into so-called research teams, which are expectedly consistent. European teams should define a strategy, share budgets and generate activity reports to justify they still deserve to exist. They are regularly challenged by numerous "administrative research managers", who are no longer researchers, but whose job is to "organize". Obviously, I think that the model where a department is like an incubator of entrepreneurial researchers is the right model. American researchers focus on their team, spend time on their own activities and are committed to succeed in academy by any mean. European researchers waste their time in meetings and in bureaucratic activities. Furthermore, the former model enables paradoxically better collaborations among researchers because these spontaneous collaborations are not based on any explicit agreement.<br />
<br />
Secondly, <b>research funding target individuals, not collaboration</b>. Europe is crazy about "calls for collaborative projects". Our beloved European funders seem convinced that the only way to do research is to make people work together on a well-defined topic. European companies interested in academic research contribute to research through collaboration in these projects. I will again exaggerate a bit, but collaborative projects are not the norm in America. Researchers get small amounts of money from companies through direct grants, which favor transient, short, focused cooperation. And they also receive <i>individual</i> grants from their public funding agencies. Such model does not force researchers to waste a significant amount of time at collective writing, synchronization meetings and expense justification. Ask American researchers who experienced European projects if they want to do it again. Their answers are likely to be harsh about this crazy administrative nightmare.<br />
<br />
I found this research organization far more efficient since it allows researcher to focus on their core activities. And I am afraid that the situation gets especially worse in France because I see a growing number of "administrative managers" who gravitate around the academic world. They are expected to be "interface" between researchers and funders, but their job (to organize researchers and to set up "calls for projects") actually interfere with researchers.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-19943015369945759632012-10-19T17:40:00.003+02:002012-10-30T23:41:14.914+01:00Lessons learned at UWaterloo (1st part): the Co-operative Education programI spent one year at <a href="http://uwaterloo.ca/">University of Waterloo</a> in the <a href="http://ece.uwaterloo.ca/">Electrical and Computer Engineering department</a>. I will try to extract from this fruitful experience a small set of short lessons. Here is the first one, an ode to the so-called <a href="https://uwaterloo.ca/co-operative-education/about-co-operative-education">Co-operative Education</a> system.<br />
<br />
What Waterloo calls a co-operative education system is a <a href="http://en.wikipedia.org/wiki/Dual_education_system">dual education system</a>, which combines academic studies and professional works. We also have such program at Telecom Bretagne (my employer), <a href="http://www.telecom-bretagne.eu/formations/ingenieur_specialise/">see this link (only in french)</a>. All undergraduate programs are "co-op" at Waterloo. According to rankings based on surveys, it works pretty well for them (<a href="http://www.businessinsider.com/the-worlds-best-engineering-schools-2012-6.html">#29 for Business Insiders</a>).<br />
<br />
In France, dual education system at the graduating level is not the most prestigious curriculum. The "<i>royal way</i>" consists of two harsh years focusing on abstract mathematical concepts, a success in a ultra-competitive exam, then three years in an engineering schools at socializing (i.e. partying) and specializing. Students enrolled in dual education system are not considered as the best because they have not demonstrated outstanding scholar skills at the ultra-competitive exam. <a href="http://peerdal.blogspot.fr/2011/01/computer-science-and-engineers-bad.html">I already expressed</a> serious concerns about such curriculum in a modern (i.e. computer oriented) society.<br />
<br />
On my side, if I had to hire one engineer in my research team or in a start-up, I would definitely hire a "dual education" engineer. As far as I can see at Telecom Bretagne and UWaterloo, students have a lighter scientific background on the fundamental areas. However, they just program well. And they just work well. I have to admit that, like probably most companies, I value "programming well and working well" far higher than "having a strong background on fundamental scientific areas".<br />
<br />
Dual education is an efficient way to teach software programming and project management, since, in general:<br />
<ul>
<li><b>Teachers don't code.</b> You can't count on them to learn programming tricks.</li>
<li><b>Teachers can't catch up all new technologies.</b> Nobody is an expert in MapReduce, Ajax, and ObjectiveC at the same time. You can't expect that from teachers neither.</li>
</ul>
<div>
During academic terms, teachers can focus on the fundamental of programming and they can skip the courses about languages and technologies. During their terms spent in companies, students can discover the latest technologies and code with professionals. Good match, ins't it?</div>
gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-41576964303525182202012-07-11T23:53:00.000+02:002012-07-11T23:53:40.282+02:00On the pivotal role of post-doc in research groupsA sabbatical is a great opportunity to study the internal process of other research groups. For a young European scientist like me, there is much to get from observing what American professors implement for the management of their large teams. In general, academic people are reluctant to apply industry-like management processes, which are supposed to prevent groups to be creative and lively. However, the research is becoming objective-driven, and the raise of grant agencies and project-oriented funding makes that an unexperienced young professor can now receive enough money to hire a large team of researchers. There is a need to address the tabooed topic of research group management.<br />
<br />
A unique characteristic of research groups is the huge gap between a graduate "master" student, who has some scientific background but actually knows nothing, and a senior post-doc, who is supposed to be a peer, fellow researcher. One of the purposes of a research group is to assist the development of new skills… and to let people leave when they are, at last, autonomous and efficient.<br />
<br />
It is my understanding that post-docs are the most challenging to work with. Some of them are super-PhD, while some others are rather mini-professor. Most of them do no longer require to be "tutored", but they still have to acquire some critical skills. In particular post-docs should ideally develop their own ideas from scratch, tutor younger students, actively contribute to industrial collaborative project, and expand their professional network.<br />
<br />
On the one hand, delegating is dangerous for a professor. If a collaborative project fails, the one that will be directly affected in the future is the professor, not the post-doc. If young students spend too much time working on barely publishable ideas, utilize old-school technologies and miss latest exciting papers, it is the professor who eventually has to make the student catch up, not the post-doc. On the other hand, delegating is a real chance to expand the research group, to work on new areas, and to offer the opportunity to the new post-doc to acquire critical skills/experiences she misses.<br />
<br />
For these reasons, the management of a post-doc is very touchy. On my side, I consider the following:<br />
<ul>
<li>before opening a post-doc position, I will clearly define my needs. I identified at least three critical needs that might pop up someday, and that would justify opening a post-doc position:</li>
<ul>
<li>I want to be assisted for tutoring young students</li>
<li>I want to partly delegate the management of a heavy collaborative project</li>
<li>I want to explore a well-identified brand new topic</li>
</ul>
<li>once my needs identified, I hope that finding a matching post-doc will be easier. Compared to my previous experience, I will pay more attention to the actual motivations of candidates, and I will pay less attention to their background or their past achievements. Of course it is important to know whether the candidate can write paper or produce experimental stuff at the expected level of quality for a top academic conferences, but it is even more important to know what is the status of the candidates regarding the need.</li>
<li>then, if objectives are clear and well-understood on both sides, I guess the collaboration shall be more productive.</li>
</ul>
<div>
<br /></div>gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-63980595654675900232012-03-09T21:35:00.000+01:002013-07-24T22:39:07.267+02:00About faculty positions in Europe (and especially in French Grandes Ecoles)I hear a lot of complaints from post-docs and near-end PhD students about the quasi-impossibility to obtain a faculty position in North America today: too few open positions and too many very strong candidates with impressive publication history and dithyrambic recommendation letters. When I ask these frustrated candidates "<i>Do you consider positions in Europe?</i>", they usually look at me strangely. Europe?<br />
<br />
Since we have <a href="http://www.telecom-bretagne.eu/ecole/ressources_humaines/offres_d_emplois/mc-info-eng/">an open <i>tenured </i>faculty position in my lab</a>, I think it is time to explain what a faculty position means in Europe / in France / at Telecom Bretagne.<br />
<br />
<b>Life for faculties in Europe.</b> The vast majority of universities (and research centers) are located in the downtown of major cities. There is no university in the middle of nowhere in Europe. A typical city hosting an university is a major city in the sense that such city concentrates everything you need for a reasonably good urban life: shops in downtown, cultural events, and good public transport (metro, train, airport). In cities inhabited by more than 300.000 people, you can find everything, especially services and jobs. Smaller cities are generally also lively nice places to live. For example, the city of Brest (France, 170.000 people, 300.000 with suburbs) is incomparably more lively than Waterloo (Ontario, aggregated population of 400.000 people with Kitchener and Cambridge).<br />
<br />
There is of course a language issue, since countries like France, Italy or Spain are still not exactly english-friendly. I think it is no longer a major issue for teaching. Most good universities have developed english-based courses, and recruiters prefer now a strong international candidate to fluent ones. Besides, I have three comments: (i) things change, the ratio of people speaking english increases, Europeans themselves travel more and get used to dealing with people from abroad countries. (ii) from my experience, kids are fluent in a new language in less than one year. It might be harder for parents, but people with a decent social life should be able to converse in a couple of years. (iii) multilingualism is one of the key assets of Europe. It is a chance for curious intelligent open-minded people. And faculties are expected to be curious intelligent and open-minded.<br />
<br />
One of the major drawbacks of Europe is that every country has its own recruitment process. Since 2007, <a href="http://en.wikipedia.org/wiki/Bologna_Process">all European universities have the same curriculum</a>. I think it is just a question of time that higher Education policies will be harmonized as well. But it is currently the main issue, typified by the crazy French system.<br />
<br />
<b>Faculty positions in France.</b> All faculty positions in France are tenured: once you get hired, you can stay here forever. Moreover, the life in France is among the very top worldwide (in particular weather, cultural life, infrastructure and service quality). The combination of the above should place France as the first location for young scientists from all over the world. France however suffers from two critical drawbacks.<br />
<br />
The first drawback is the recruitment process, which has been created by French for French. It is a ridiculous Kafkaian system, which actually prevents the development of competitive French research centers, In short, if you are not within the system, you have no chance to get in because you simply cannot know how to apply. There are in France four decent research places: universities (for traditional associate-professor and professor position), <a href="http://en.wikipedia.org/wiki/French_National_Centre_for_Scientific_Research">CNRS</a> (full-research position in fundamental areas), <a href="http://en.wikipedia.org/wiki/National_Institute_for_Research_in_Computer_Science_and_Control">INRIA</a> (full research positions in Computer Science) and <a href="http://en.wikipedia.org/wiki/Grandes_%C3%A9coles">Grandes Ecoles</a> (traditional professor positions but teaching only to small population of graduating students). Each of these places has its own recruitment process, with a lot of specific French acronyms and terms. They all require candidates to dive into websites with no guarantee that the English translated page is accurate and updated. For example, the <a href="http://www.dgdr.cnrs.fr/drhchercheurs/concoursch/informer/default-en.htm">recruitment at CNRS</a> is based on the concept of <i>Sections</i>. Should you be able to know your Section, you might face some terrible issues like understanding <a href="http://www.cnrs.fr/comitenational/calendrier/general/cal_p12_di.pdf">this wonderful PDF</a>. Universities have the worst recruitment process. Go to <a href="https://www.galaxie.enseignementsup-recherche.gouv.fr/ensup/info_recrutement_portailcandidat.html">this portal</a> if you are crazy enough to candidate, but please don't forget that if you want to apply for 2012 recruitment process, you first had to apply before Dec 31st 2011 in order to be authorized to actually apply four months later. No kidding. INRIA has the best <a href="http://www.inria.fr/en/institute/recruitment/offers">recruitment process</a> (with a LaTeX template for the application). Grandes Ecoles are autonomous small entities without much visibility. For the brand new Institut Mines-Telecom, the new <a href="http://www.mines-telecom.fr/p_en_imt_recrut_ensch_395.html">recruitment website</a> is still under construction, with a lot of infamous 404 pages and various links toward webpages in French.<br />
<br />
The second drawback is the salary. <a href="http://www.universityworldnews.com/article.php?story=20120330211434168">In France, you cannot be a rich scientist</a>. For CNRS and traditional university positions, it is even worse. A young scientist with a tenured position in an university cannot live decently at Paris. The salary (around 2000 euros monthly after tax) ruins your chances to find any apartment in Paris and nearby. INRIA and Grandes Ecoles are a bit more reasonable with monthly salary starting around 2500 euros. For example, after five years of experience, my salary is slightly higher than 3000 euros after tax. In all French cities (except Paris and Nice), such a salary allows a comfortable life, but it is still borderline for a family. The comparisons to other countries are not in favor of France. On the one hand, there are still many candidates despite the low salaries. On the other hand, best candidates, especially those who know the US system, are reluctant to apply.<br />
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<b>This particular position at Telecom Bretagne.</b> For young scientists with young (or upcoming) kids, Telecom Bretagne is an outstanding place, with a scenic oceanic coast, a kid-friendly climate (temperatures ranging from 5˚C to 20˚C), and cheap housing (a 4-bedroom house near the beach can be rented for less than 1000 euros per month). Brest is considered as one of the ugliest French city, but, with respect to world standard, it is still a nice lively city with an attractive homogeneous downtown. I would argue that Brest is typically a better place than the majority of cities in US, Germany or Japan.<br />
<br />
Telecom Bretagne is one of these strange typically French "Grandes Ecoles". In short, the best French students go to Grandes Ecoles for graduating as engineers. Since Grandes Ecoles are dynamic small entities, specific partnerships with the best institutions all over the world have also been created in order to attract excellent abroad students (one third of students at Telecom Bretagne are not French). Hence, professors teach to small-size international population of smart students with whom it is possible to experience new pedagogical processes, including active learning and project-based education. However, these students will become engineers (the ratio of students willing to go to PhD is less than 0.1) and they are highly-demanding in average.<br />
<br />
Fifteen years ago, Grandes Ecoles were only about teaching. The recent development of research activities explains the diversity of profiles in the so-called "departments". Professors with academic ambitions are free to develop their own research agenda, but they will have to find grants in order to hire PhD students and post-doc. Fortunately, the school has strong industrial relationships and good connections with major French research centers, therefore it is not that hard to find money if the research activity is within a hot area.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com1tag:blogger.com,1999:blog-916089221241646444.post-32598264103794130002012-02-09T15:43:00.000+01:002012-02-10T20:45:40.010+01:00The day a rejected paper will end up in court<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">
Conferences are no longer nice meetings among gentlemen who care about science. They are the center of <a href="http://www.wisdom.weizmann.ac.il/~oded/on-struggle.html">a huge competition</a> for thousands of scientists. An acceptance in a major conference can change the career of a scientist and the daily life of a laboratory. It is money and it is fame.</div>
<br />
The goal of the peer-reviewing process has naturally shifted from validating the accuracy of a scientific work to selecting a subset of papers. The reviewers have mutated into hunters tracking any reason to crush a paper. All the gentle and polite manners from "<a href="http://www.agu.org/pubs/authors/pdf/PeerReview_Guide.pdf">guides of peer-reviewing</a>" sound so XXth century. In computer sciences, the <a href="http://cacm.acm.org/magazines/2010/7/95070-hypercriticality/fulltext">"hypercriticality" of scientists is well identified</a>.<br />
<br />
Unfortunately, all harsh reviewers are not gifted. Reasons for rejecting a paper frequently come from wrong beliefs, from major misunderstanding or from an obsession for a tiny flaw. These are negative badly-justified reviews, which sometimes make the authors speculate about a possible bias in the reviewing process: the reviewer was a competitor in the same domain, the reviewer was not an expert, the reviewer had personal grievances against the authors, the reviewer was a well-established scientist who does not want to see any newcomer out there...<br />
<br />
What are the options for an angry author with a supposed unfairly-reviewed paper and its negative consequences (the money loss and the degraded career)? Let's call a lawyer.<br />
<br />
The roles of every entity involved in the traditional academic process are well summarized <a href="http://www.ams.org/notices/201101/rtx110100062p.pdf">in this nice paper</a>. Sometimes, the editor of the venue <a href="http://www.sigcomm.org/ccr/papers/2012/January/2096149.frontmatter">describes the process</a> in used. But the reality is that <b>there is no well-defined rule, no engagement</b>. In fact, it is written nowhere that every paper should be <i>fairly</i> reviewed. An author can only <i>hope</i> that the process is fair because the process is <i>usually said to be</i> fair. I have actually no idea what a lawyer could do versus a no-rule process.<br />
<br />
I have always been astonished by Boeing (or Airbus) appealing a decision from an orderer when their bid is rejected. In my naive vision, how can anybody challenge the decision of a private company? When the orderer is the Air Force, there must be rules, for sure, but the idea is the same for a paper to, say, Infocom. But here is the point. There is no Infocom. More precisely,<b> our beloved top-conferences might belong to anybody</b>,<a href="http://gameshelf.jmac.org/2010/02/that-new-official-infocom-web/"> including Infocom</a>. I am not sure to know what a lawyer could do versus a no-entity.<br />
<br />
Is is serious?<br />
<br />
The rebuttal process is probably a good idea, which has the potential to reduce some unfair decisions. But it is still another prehistoric practice based on oral tradition and informal discussions between those who are supposed to be the owner of something that does not exist, except in author's mind. In medicine, some scientists have argued about the creation of a "supreme court" whose role would be to "judge the judges" (<a href="http://qjmed.oxfordjournals.org/content/95/12/769.long">here</a> and <a href="http://jama.ama-assn.org/content/272/2/166.abstract?ijkey=dae18994d7ac3571ed081f07e0b8951d70506707&keytype2=tf_ipsecsha">there</a>). But the motivation is to prevent new scandals related to misbehaving editors. This court would deal with serious cases, not slightly unfair reviews. Maybe academics should look at what has been done in sports to legally organize the structures. Societies like IEEE or ACM could also consider to create a "mediator committee".<br />
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Otherwise a rejected paper will end up in court, then who knows who might be considered as responsible.<a href="http://www.blogger.com/"></a>gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com1tag:blogger.com,1999:blog-916089221241646444.post-47627425751804327932011-11-28T21:40:00.001+01:002011-11-29T16:06:07.112+01:00Incremental improvements for CS conferencesScientists like to debate about the general organization of academic life. Lately, some have called for <a href="http://cacm.acm.org/magazines/2011/10/131405-rebooting-the-cs-publication-process/fulltext">a clean-slate revolution based on open archives</a>. Yet, as for the majority of clean-slate proposals on well-established processes, I am doubtful that such a shift can occur. But in the meantime, nothing is done to actually fix the issues of the current process. In particular, I have the feeling that academic conferences in computer science (at least in my communities, which span networking, multimedia and distributed systems) are getting worse, and it seems that nobody cares because the most active researchers in this area are too busy preparing their utopian clean-slate revolution.<br />
<br />
So, let me try to give below four incremental improvements that every serious conference should implement, for the sake of a better academic life. Two are quite easy:<br />
<ul>
<li><b>no more deadline extension</b>. A deadline extension is the irrefutable proof that a conference is crappy. A deadline extension means indeed that either the conference does not attract enough solid submissions or the scientists who submit in this conference are unable to finish a work on time. In both cases, it would be a shame to be associated with such a conference. Furthermore deadline extensions bring at least three very negative effects.</li>
<ul>
<li>it creates an unfair gap between the happy fews who are in the awareness and the others. A scientist who knows in July 2011 that ICC deadline will be Sep 28 has a different schedule than the other scientist who naively thinks the deadline is Sep 6. </li>
<li>it is now folklore to announce an extension a few hours before the deadline. This is highly irrespecutful for the (unaware) authors. <a href="http://andreweckford.blogspot.com/2011/09/icc-deadline-fiasco.html">Week-ends can be ruined to fulfill a deadline</a>, which you discover on Monday has been extended for two weeks.</li>
<li>the day before a submission is stressful. A (lately announced) deadline extension multiplies the number of deadline-stressful days by two. Deadline extensions are killing me.</li>
</ul>
<li><b>a list of accepted papers on the conference webpage the day of the notification</b>. Why is it so hard? <a href="http://www.cs.tau.ac.il/~iftgam/conflist.htm">An ugly txt-formatted list of accepted papers</a> is just what most scientists want for. From such a list, it is possible to find a link toward an ArXiV or a technical report on the webpages of the authors of accepted papers. Moreover, titles are inspiring, the sooner every scientist can read the titles, the more inspiring it is. And don't forget curiosity of course. Who did pass the cut this year?</li>
</ul>
<div>
Two other improvements are less incremental, but I think their impact would be worth.</div>
<div>
<ul>
<li><b>no blindness at all</b>. The debate about single vs. double blind is a classic. But very few scientists discuss the blindness of reviewers. There is however a raise of complains about the reviews that are <a href="http://ccr.sigcomm.org/online/files/p3-v41n3ed-keshav-editorial.pdf">too harsh</a>, <a href="http://twitter.com/#!/csperkins/status/137329719245934592">scientifically wrong</a> and <a href="http://gumption.typepad.com/blog/2010/12/reflections-on-reviews-rebuttals-and-respect.html">impolite</a>. It is not hard to believe that if the reviews were signed by their authors, they would be written more carefully. Some argue that this would bring potential desires of revenge among scientists. This ridiculous argument assumes that scientists are no better than kids unable to recognize argued criticisms and unable to retain their negative thoughts. If you are not optimistic about human nature, you should notice that research communities are enlarging. So, the revenge desires of a few bad scientists have really few chances to affect you because the probability that these bad guys represent a majority of reviewers for one of your paper is actually very low. Not mentioning that, academic revengers being stupid people, they are probably not in the committees of top-conferences, so you have nothing to lose. And if you face a majority of reviewers who want to unfairly reject your papers because of your previous bad reviews, well it may be time to consider writing better reviews.</li>
<li><b>open access to papers</b>. I have already signed this <a href="http://www.researchwithoutwalls.org/">pledge</a> about open access. I know that <a href="http://matt-welsh.blogspot.com/2011/11/research-without-walls.html">academic professional societies (ACM, IEEE and so) have to re-invent themselves</a> but <a href="http://computational-geometry.org/documents/ACM-Poll.pdf">we will not wait them to do it</a>. We cannot degrade the quality of the scientific activity just because a few jobs are in stake.</li>
</ul>
</div>
I think it is the role of the program committee members to alert their chairmen that the academic life would be far better if conferences stick to these simple rules.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com2tag:blogger.com,1999:blog-916089221241646444.post-21653809646961549002011-11-09T23:18:00.000+01:002011-12-13T21:51:31.392+01:00What's up in networks (3/3): dashThe last post in this mini-series. After <a href="http://peerdal.blogspot.com/2011/10/latest-news-from-networking-area-part-1.html">openFlow</a> and <a href="http://peerdal.blogspot.com/2011/11/whats-up-in-networks-23-hetnet.html">hetnets</a>, here is dash.<br />
<br />
<span class="Apple-style-span" style="font-size: large;">DASH or Dynamic Adaptive Streaming over HTTP</span><br />
Although it is not exactly what the MPEG scientists have promoted for a decade, most of today's video traffic is based on HTTP and TCP (Netflix player, <a href="http://www.iis.net/download/SmoothStreaming">Microsoft Smooth Streaming</a> and <a href="http://osmf.org/">Adobe OSMF</a>). And it works. The video traffic is exploding: <a href="http://arstechnica.com/tech-policy/news/2011/10/netflix-accounts-for-nearly-one-third-of-north-american-web-traffic.ars">adaptive streaming already represents more than one third of the Internet traffic at peak time</a>, and it is expected to prevail, <a href="http://www.cisco.com/en/US/solutions/collateral/ns341/ns525/ns537/ns705/ns827/white_paper_c11-520862.html">even on mobiles</a>. Facing this plebiscite, the MPEG consortium has launched the <a href="http://multimediacommunication.blogspot.com/2010/05/http-streaming-of-mpeg-media.html">process of standardizing DASH into MPEG</a>.<br />
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In short, for a given movie, the video server publishes a manifest file in which it declares several video formats. Each format corresponds to a certain encoding, so a certain quality and a certain bit-rates. All these different videos of the same movie are cut into chunks. A client requesting a movie selects a given video format and then starts downloading the chunks. On a periodic manner, the client tries to estimate whether this video encoding fits the capacity of the network link between her and the server. If she is not satisfied, she considers switching to another encoding for the next chunks. What is the best chunk size, how to estimate the link capacity, what is the best delay between consecutive estimation, how to react to short-term bandwidth changes, how to switch to another encoding… are among the questions that have not received the attention of the scientific community, so <a href="http://www.google.com/url?sa=t&rct=j&q=akhshabi%20begen%20dovrolis%20experimental%20rate%20adaptation&source=web&cd=1&sqi=2&ved=0CCEQFjAA&url=http%3A%2F%2Fwww.cc.gatech.edu%2F~dovrolis%2FPapers%2Ffinal-saamer-mmsys11.pdf&ei=Ddq6Tof8I8fo0QH5xtXeCQ&usg=AFQjCNEeyAx3TLJ5DxNTtFvkUYFGOds11w&sig2=JTzpRcmckVgvBElzkIGdpw">every DASH client implements some magic parameters</a> without any concern for potential impacts on the network.<br />
<br />
Despite the <a href="http://www.sigmm.org/">multimedia scientific community</a> and the <a href="http://www.mpeg.org/">video standardization group</a> are large lively communities, many research issues related to DASH have not been anticipated and sufficiently addressed. Among them, I highlight:<br />
<ul>
<li><b>When several concurrent DASH connections share the same bottleneck, the congestion control mechanism of TCP may be compromise</b>. In fact, a DASH connection is based on TCP, which implements an adaptive congestion control with proven convergence toward a fair sharing of the bottleneck among concurrent connections. By incessantly adapting the flow bit-rate DASH may prevent the convergence of TCP. If network bottlenecks locate on links that are shared by hundreds of concurrent DASH flows, the lack of convergence of the congestion control mechanism is a risk. I may overestimate the impact, but at least understanding the impact of DASH adaptive policy (which seems to use a lot of random parameter settings) on the eventual convergence of a congestion control policy is an exciting scientific topic.</li>
<li><b>When multiple servers store different video encodings of the same movie, the client may incessantly switch from a video encoding to another.</b> A DASH connection works especially well when the bottleneck is always the same, whatever the chosen video encoding. In this case, the adaptive mechanism converges toward the video encoding that fits the bottleneck capacity. But in today's Internet, the content can be located in various distinct locations: CDN servers, Internet proxies, and content routers with caching capabilities. If the links toward the different encodings have different congestion level, the DASH adaptive algorithm may become crazy. </li>
<li><b>A DASH connection does not support swarming</b>. Swarm downloading (one client fetching a large video content from multiple servers) was expected to be enabled by both the multiple copies of the same content and the chunk-based video format. If every chunk comes from a different server, the congestion cannot be accurately measured. In fact, DASH cannot implement a consistent behavior when multiple paths are used to retrieve the video chunks. </li>
</ul>
By the way, DASH is yet another point in favor of HTTP, which is becoming <a href="http://conferences.sigcomm.org/hotnets/2010/papers/a6-popa.pdf">the de facto narrow waist of the Internet</a>. The motivations for using HTTP include its capacity to traverse firewalls and NATs, its nice human-readable names and its capacity to leverage on Internet proxies and CDNs. Somehow, DASH adds congestion control and adaptive content, making the HTTP protocol even more powerful. But the gap between its huge utilization over the Internet and the lack of understanding of its behavior at large scale has the potential to scare network operators. I guess it is the way Internet has always evolved.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com2tag:blogger.com,1999:blog-916089221241646444.post-85374846568654155032011-11-02T17:01:00.001+01:002011-11-02T17:14:11.565+01:00What's up in networks (2/3): hetnet<div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Here is the second chapter of the mini-series about some (not-so-fresh) topics in networking area. After <a href="http://peerdal.blogspot.com/2011/10/latest-news-from-networking-area-part-1.html">openFlow</a>, hetnet.<br />
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<span class="Apple-style-span" style="font-size: large;">Hetnet, or the Heterogeneous Cellular Networks:</span></div><div style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">I am probably not the only one to get bored by GSM cellular networks: they have been created by phone engineers who disliked Internet, they are full of acronyms, they are controlled by an operator, they just works. But cellular networks are now the most common way to access to the Internet. Moreover the devices using these networks are full-featured computers, which are managed by owners who install a lot of applications. <a href="http://www.gsm.org/newsroom/press-releases/2011/6491.htm">The number of devices connected to cellular networks is expected to grow dramatically</a>.<br />
<br />
Next-generation cellular networks have good chances to differ from our plain old GSM networks. Here are two technologies that may change the game:<br />
<ul><li><b>femto base stations</b> are small and cheap base stations that anybody can buy and install on its own wired Internet connection (for example <a href="http://www.sprintenterprise.com/airave/tellMeMore.html">here</a>). It means that the clients of a wireless service provider pay (base stations + landline Internet communication + consumed electric power) to improve the infrastructure of the carrier and to have an excellent quality of service at home. <a href="http://3ginthehome.wordpress.com/2011/10/16/femtocell-launches-continue-through-october/">Carriers are all jumping into this idea</a>. I still don't understand why would a user prefer to buy a base station and connect to Internet through the 4G although she can use wifi. The main argument is that, wifi wireless spectrum being free and badly managed, a local network can have poor performances because <a href="http://in-stat.com/press.asp?ID=2966&sku=IN1004769WS">too many wifi access points compete</a> or because <a href="http://news.idg.no/cw/art.cfm?id=0A5EA494-1A64-67EA-E48D8F32F5BFAF00">too many devices share the pool of wireless channels</a>. The 4G spectrum is licensed and managed by the operator, so some wireless channels can be "reserved" to a user. But if everybody has its own femtocell at home, licensed channels will become scarce too, and nobody will tolerate paying for a femtocell that interfere with the neighbors' ones. In order to tackle this issue, nearby femto base-stations should collaborate to share the wireless spectrum and react to changes in the radio environment (especially when neighbors decide to turn on/off their femto base stations). All scientists interested in peer-to-peer and ad-hoc networks will have fun with the problem of channel allocation: end-users form the infrastructure, ensuring a fair sharing of scarce resources is a challenging objective, clever distributed algorithms should solve the problem, incentives to turn on/off the femtocells should be taken into account. As shown in <a href="http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5876502&tag=1">this article</a>, both deployment and management of femto hetnets are still unclear. Those who are not afraid of acronym orgies can look at <a href="http://www.cwc.oulu.fi/summerschool2011/Femtocells_Hamalainen2011.pdf">these slides</a> for a summary of 3GPP standard and a nice telco-oriented overview of the research problems.</li>
<li><b>direct device-to-device wifi communication</b> is <a href="http://www.wipeer.com/index.html">a long-awaited feature</a>. Hurrah, <a href="http://www.wi-fi.org/Wi-Fi_Direct.php">WiFi Direct</a>, which is the official name of this feature in the WiFi alliance, is <a href="http://developer.android.com/sdk/android-4.0-highlights.html#UserFeatures">included in the new Android OS version</a>. At least, wifi direct transmission between devices is becoming a reality, which means that the thousands of academic papers about mesh networks and hybrid ad-hoc cellular networks are suddenly worth reading. However, things have changed. Extending the coverage area of base stations, which has been the most frequent motivation in previous works related to mesh networks, is no longer the main concern of mobile carriers. It is now <a href="http://www.notava.com/notava/uploads/Whitepapers/Internet_growth_V10.pdf">all about mobile data offloading</a>, that is, avoiding communication via the macro base station. In this context, network operators may combine wifi direct and data caching in devices to reduce the amount of requests sent to the Internet. In other words, strategies related to <a href="http://www.icsi.berkeley.edu/~barath/papers/icn-hotnets11.pdf">information-centric networks</a> may turn out to be useful in the wireless world.</li>
</ul><div>In a broader perspective, the over-utilization of wireless networks for accessing the Internet highlights an interesting paradox: the wireless transmission is inherently broadcasting (all devices near the wireless router may hear all messages) although the Internet applications are usually designed for unicast communication (a message has only one destination). The capacity of a mobile carrier to leverage on the broadcasting feature of base stations in their cellular networks may become a key asset.</div></div>gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com0tag:blogger.com,1999:blog-916089221241646444.post-3770302437568686842011-10-31T03:19:00.001+01:002011-11-02T15:57:24.605+01:00What's up in networks (1/3): openflowI found time to go a bit deeper into several (not-that-fresh) topics. I hope this quick summary will be of interest for those who did not. First of this mini-series: OpenFlow<br />
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<span class="Apple-style-span" style="font-size: large;">OpenFlow, or the Software-Defined Networks:</span><br />
Thanks to <a href="http://www.openflow.org/wp/learnmore/">OpenFlow</a>, I now understand the "<i>control plane vs. data plane</i>" idea, which I thought were mysterious magic words allowing telco engineers to recognize themselves. In <a href="http://www.networkworld.com/news/2011/041411-open-flow-faq.html">the OpenFlow world</a>, there are some dumb switches that route packets according to a routing table, and there is a clever controller, which orchestrates these switches. Switch-Controller communication uses the OpenFlow protocol.<br />
<br />
The first novelty is that the OpenFlow protocol has been designed at Stanford, therefore (i) it is cool, (ii) software engineers have heard about it, and (iii) it is endorsed by a buzz concept, namely <a href="http://www.technologyreview.com/biotech/22120/">software-defined networking</a>. The second novelty, but a noteworthy one, is that the main network equipment vendors integrate OpenFlow API in their switches (at least <a href="http://www.networkcomputing.com/next-gen-network-tech-center/231901753">Juniper</a> and <a href="http://blogs.cisco.com/datacenter/whats-new-with-cisco-and-openflow/">Cisco</a>). So, it is becoming real: software developers will really be able to control a network remotely.<br />
<br />
OpenFlow is both networks and software:<br />
<ul><li>In the network area, there is only one truth: every new concept is something already done twenty years ago. Good news for OpenFlow: it looks like MPLS. Therefore OpenFlow is a networking concept. \qed</li>
<li>Computer scientists are driven by vaporous concepts like model abstraction, composition and semantic. Guess what? <a href="http://www.frenetic-lang.org/">OpenFlow designers dangerously embrace them</a>. Even worse, network scientists have <a href="http://www.cs.princeton.edu/~jrex/publications.html#openflow">started publishing in POPL and ICFP</a>.</li>
</ul>More seriously, OpenFlow meets a demand. More and more "independent" networks have specific needs that cannot been addressed by router vendors. For example the network in a data-center. Private <a href="http://www.bigswitch.com/wp/about-us/">enterprise networks</a> and even <a href="http://gigaom.com/2011/03/23/are-home-networks-destined-for-cloud-based-networking/">next-generation home networks</a> are also complex networks, which would work better if they could be managed according to the wishes of their owner. OpenFlow provides the friendly interface that allow anybody (should (s)he knows programming) to become the network operator for any such network. Needless to say, this perspective brings a lot of excitements and uncertainties (see for example <a href="http://packetpushers.net/openflow-state-of-the-union-reflections-on-the-openflow-symposium/">here</a> and <a href="http://gigaom.com/cloud/forget-cool-openflow-and-networking-is-now-hot/">here</a>).gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com3tag:blogger.com,1999:blog-916089221241646444.post-46414757668147639462011-10-21T05:40:00.000+02:002011-12-22T15:45:28.626+01:00Was P2P live streaming an academic bubble?Or is the academic community just disconnected from the reality?<br />
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In brief, the motivation for peer-to-peer live streaming is that servers are unable to deliver a live video at large-scale. I know, it sounds crazy in a You-Tube world. In peer-to-peer system, clients should help the poor video provider broadcast its video, without much delay nor quality degradation. To have more fun, no server at all is authorized.<br />
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Believe it or not, but <a href="http://scholar.google.com/scholar?q=peer-to-peer++stream">Google finds more than 50,000 <b>scientific</b> documents</a> dealing with this issue or one of its variants. Today, only <a href="http://www.streamingstar.com/download-p2ptv.htm">a handful of systems based on a peer-to-peer architecture</a> are used, mostly to illegally broadcast sport events. As far as I know, these systems (released before the crazy scientific boom on the topic) do not implement one thousandth of the scientific proposals described in these 50,000 articles. It seems that the small teams of developers behind these programs haven't found the time to download/read/understand any of these articles.<br />
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Was this abundant scientific production useless? Probably not. First, scientists made some practical achievements. For example, the <a href="http://www.p2p-next.org/">P2P-Next</a> project has released under L-GPL tons of codes implementing state-of-the-art solutions, including <a href="http://libswift.org/">the multiparty <i>swift</i> protocol</a>. A <a href="http://trac.tools.ietf.org/html/draft-ietf-ppsp-reqs-03">protocol</a> is also in the standardization process at IETF. Consequently, the next generation of peer-to-peer programs should be able to cut down TV media industry as it did for music industry. Second, these studies have produced interesting scientific results beyond the P2P streaming applications, for example the robustness of randomized processes for broadcasting data flows in networks. It reminds me the golden era of ad-hoc networks (2000-2005), where scientists had a lot of funs playing with graphs and information, even if only militaries have found these protocol useful. We do understand networks better now!<br />
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But, did it deserve 50,000 articles? Of course not. <a href="http://news.cnet.com/8301-17939_109-10125447-2.html">Under-the-spotlights start-ups (Joost)</a> and <a href="http://www.bbc.co.uk/blogs/bbcinternet/2008/12/introducing_iplayer_deskto.html">publicly-funded pioneering companies (BBC)</a> switched back to centralized architecture four years ago although they had a decisive technological advance. It looks like there is no bankable application out there. Maybe it was for the beauty of science, but whoever has funded these research works can only hope that randomized processes in networks will eventually find a way to improve human conditions in the world. Or maybe it was just a good idea to occupy people?<br />
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So, yes, P2P live streaming was a bubble. Here are three quick observations, which would deserve a more accurate analysis:<br />
<ul>
<li>An academic bubble starts like a financial bubble. In the latter, no company can take the risk to not invest in an area if all competitors do. In an academic bubble, neither funding agency nor program committee can challenge an abrupt growth in the number of papers in a given area. Therefore scientists obtain quick fundings, publications, and citations, which fuel the bubble. However the academic bubble differs from the financial one because there is no critical damage when the number of papers abruptly drops. The bubble does not hurt when it explodes. So, <b>nobody tries to understand what went wrong</b>. In other words, this bubbling trend can only grow, and the next bubble (content-centric networking?) has good chances to be even bigger.</li>
<li>Tracking the next bubble is attractive. Scientists are rewarded on their impact on the community. In this context, the authors of seminal works in this area, for example <a href="http://en.wikipedia.org/wiki/Chord_(peer-to-peer)">Chord</a> (nearly 9,000 citations despite <a href="http://en.wikipedia.org/wiki/Distributed_hash_table#Applications_employing_DHTs">distributed hash table has found few usefulness</a>) or <a href="http://research.microsoft.com/en-us/um/people/antr/SplitStream/default.htm">SplitStream</a> (more than 1,000 citations for a system relying on <a href="http://en.wikipedia.org/wiki/Multiple_description_coding">a video encoding that has only been used by academics</a>), are rock-stars. <b>Anticipating the sheepish behavior of scientists has become a key academic skill</b>.</li>
<li>Scientists are still incapable to focus their energy toward their right client, who were the aforementioned small teams of hackers in this case. This is <b>yet another motivation for revamping the way scientific results are delivered in computer science</b>. Giving free access to papers, releasing the code that has been used in the paper, participating in non-academic events or finding echoes in other communities are among the solutions. Not only to be meaningful, but also to prevent bubbles.</li>
</ul>
Just an idea: when the bubble is officially there, would it be possible to officially forbid the bullshit motivation paragraphs in the paper? I wish authors would admit that they just want to have fun developing a new model in a useless bubbling scenario.gwendalhttp://www.blogger.com/profile/03218408284183585709noreply@blogger.com5