Die richtigen Meister. Ja, so, as you've been aware with the move to Leipzig, we were entering a whole new area for Congress. Everything obviously is quite large now, everything is bigger now. And just to give you an idea, here's the size of the CCH. And next to it, there's the size of Messer Leipzig. So in this presentation, we would like to give you an insight on the new challenges, which came with the growth and size, like acquiring bandwidth, redesigning our backbone, rolling out access and Wi-Fi on a much larger area than we've ever done before. And all that while adhering to new health and safety regulations. So, given the sheer size of the venue, we needed to radically scale up our network and put our top priority on upscaling safety. So, we started in summer with the summer trip to Messer Leipzig and learned all about the existing infrastructure. We were excited to discover that this venue's impressive fiber network actually includes only single mode cabling, which is our favorite type of fiber. So, as you can see, there was also plenty of free fibers available for us to use, but at the same time, we were overwhelmed by the amount of cabling. So, we needed to find a way to reduce all the information down to a usable and understandable format we could work with. So, obviously, the only sensible choice was to turn to future technology and engrave a digestible cabling diagram onto a plate of lasagna. Having feasted on all this information, we were able to see a clearer picture of the network. We are going to build for 50,000 participants of the new era of Congress. So, finally, we're making new progress with our planning. But we weren't just finished yet. Health and safety regulations are very strict in venues like this. So, lots of thought has to go into fire prevention, emergency escape planning, and other security and safety related stuff. Just like all the other teams, we were also busy ensuring everyone's safety. And, yeah, we need to do our part as well, basically. So, on the network side, this means make sure your data packets have a wide enough escape route towards the Internet. So, we've actually built a fully redundant 100 Gigabit Backbone over three in-house routers. Furthermore, while we were busy working on the on-site network layout, we asked our procurement manager to work on arranging some uplink connectivity. And as an expert in his field, we figured he would be well aware of what kind of connectivity was needed. As you know, we've seen uplink uses in the ballpark of 30 to 40 Gigabits per second in the past. So, the logical thing to do would be to arrange 50 or maybe 60 or even 100 Gigabits just to be on the safe side. Unfortunately, though, while he was beautifully arranging uplinks, we lost track of him and forgot to tell him to stop. So, next thing we knew, he had accidentally arranged 400 Gigabits of uplink capacity, leaving this building in three geographically redundant directions. So, this was possible due to some very friendly providers, some of which even loaned us their lab equipment, so we could field test bleeding-edge technology with futuristic names such as alien wavelengths, allowing us to run 200 Gigabit per second over one single wavelength toward Berlin. And, yeah, so that ended. So, after learning about this, we decided to arol with it, because, who are we to say no to more bandwidth? However, this gave us additional challenges for crying the necessary network hardware, obviously. In the past, we were always worrying that Juniper, one of our main sponsors for the network equipment, might not have the necessary amount So, this year, knowing all the facts, we're going to them early, talk to them early, and told them what we actually needed, big routers, where we connect 100 gigs, stuff like that. Unfortunately, we learned then very last minute that the routers we wanted were not available. The only routers they could give us were three times bigger than the one we were asking for. As a streamlined organization, we were running this obviously through our procurement manager, who enthusiastically agreed with the proposal, because this solves another of our problems. In Hamburg, we were talking about it for quite some time already in the last years, we could only callocate our routers in like fun sized sauners. The patch rooms here, on the contrary, are very big, well air conditioned, and with the small routers we would have in Hamburg, we would fearing that we might be running in danger of losing them in those spacious rooms here in Meise-Leipzig. So, the bigger routers were also serving a double purpose. We are not leaving them here by accident, because we're thinking, oh, there's nothing in there anymore. So, for additional safety, we introduced a triangle routed topology, so your data can still escape in case any one path is blocked by a firewall angel. This means that your data is now around about 150% more secure and safe than ever. So, upscaling was a central theme for everyone in this year's congress, also for Wi-Fi, obviously. As you know, in the CCH, there was no more room for adding more access points, which is maybe why we had to leave. But luckily here in Leipzig, we were able to grow our potential und cover more space with Wi-Fi access than ever. We brought 180 access points to Leipzig, which is the lower bar, and that's about the number we brought to Hamburg. But luckily you helped us out by running a lot of rogue access points, and that's the upper bar. So, thanks for that. Unfortunately, thereby, you ruined everyone's Wi-Fi experience on the congested bands. Yeah, the problem here is that actually SSID spamming is taking away a lot of airtime for everyone in your environment. There are people spawning up to 100, 200 different SSIDs, thus really ruining the Wi-Fi for everyone in their whole neighborhood. We saw things like this, which on paper is funny, but if you're sitting there in your assembly area and you don't get any Wi-Fi anymore, or you don't have your Wi-Fi signal, but you don't get any packets through, this is the reason why. People are starting to spam, starting to spin up their own access points, taking away frequencies, which we could really, really use for our access points. So basically, whoever did this and all the other access points out there war the reason that the Wi-Fi reception wasn't as good as it was in Hamburg. So, the problem is that when you open an access point, it has to broadcast at SSID in Beacons that are transmitted at the lowest possible frame rate, so they take up a lot of airtime, even when there's no data transmitted over them. So, please don't bring your own access points in the future. So, speaking of trolling, at one point we were looking at our traffic graphs and noticed some odd patterns that we couldn't really explain. We thought maybe it's the streaming traffic from the lecture halls, but then we figured it doesn't correlate with the lecture schedule. And then we were wondering what would cause five gigabytes of outgoing IPv6 traffic in such strange patterns. But then it occurred to us, someone was sending us a message. So, when decoded as Morse code, the traffic patterns actually read 34 C3. Yeah, we started a new tradition last year, which was quite popular and very accurate, to summarize for members of our press necessary information. We have put everything basically on one slide. So you just have to take a picture of this and then you can write all the articles you want. You have the right information, you don't need to misquote anyone or just invent some stuff. So, just to go through it real quick. We had a total uplink capacity of 400 Gigabits per second, leaving Messer Leipzig. We were telling you about this already. We had IP capacity here within Messer Leipzig and in Berlin of up to 320 Gigabits per second by diverse Internet providers who were sponsoring us. Of all this traffic bandwidth we are providing here, you were using up to 42.2 Gigabits per second, which can be better. We had a little bit of space left, so you know, next time leave your access points at home, bring some servers, bring some stuff that actually can use the traffic and then everything will be fine. Lee, get a mic if you have one or is there someone on the Internet available with the question? We're not ready yet. We have one more thing. Yeah, yeah, sorry. Actually two more things, but anyways. Yeah, we have some PIP WIFI users of over 7600. We had almost 180 access points deployed and yeah, all this wouldn't have been possible without our sponsors, of course. Thanks for providing helping us. So, so after our sponsors had delivered us 15 pallets of equipment with a great help of knock help desk and amazing amount of motivated and dedicated angels to help us with all the things we'd like to thank, everything worked out fine in the end and we were able to actually give you the networking experience you deserve. But during the planning phase, we accounted one more enormous problem. Yeah, just like in the last years, we wanted to apply our normal recipe for building this CCC network, obviously. But suddenly we ran into all kinds of issues. We couldn't really explain. Something just seemed to be off and we couldn't put our finger on the problem. But then it occurred to us, our vision was still the same as last year. So, obviously, that was the main problem. We upscaled then and secured every last, we upscaled and secured every last bit of the network, obviously, but we forgot to do the same with our vision. So, we hurried to an emergency weekend retreat and soul-searching mission to come up with a way to cope with us, gross neglect.  So, let me present to you our new futuristic upscaled, 100% safe vision. Now, finally, the universe was in harmony again and so we can peacefully rest and go to the long-anticipated questions. Hey, thank you. There are questions. There is one on the Internet to start from. Yes. Which autonomous system did we interact with the most? Sorry, can you repeat? Which autonomous system did we at the Congress interact the most? Do you have that number? I think it was Hetzner, but I don't really know. Yeah, oh yeah, it was probably Hetzner, for whatever reason. Here, microphone number one.  So, my advice would be to send it anywhere, but with a really low time to live so that the packets get dropped soon after the router and it doesn't annoy anyone, but it will show up in our graphs. And I hope this is what they did this year. Microphone number six. Is there any extended metrics or data dumps if somebody wants to dive into the graffing and data that you'll make available? I think we could publish some of them, yeah. Because we have them in our Prometheus database and then we obviously need to check which are sensitive but which aren't. But we could work on, yeah, maybe, for example, the uplink graph, if you want to analyze that in more detail, we could upload that somewhere. Just follow our Twitter account. In case we do, you'll notice it there. Microphone number one. Not really a question, but I couldn't saturate the 10-Gigabit link. I had a server in the yellow color connected to. Was it you? Was it you? I had the server and it had around three gigabits graphic most of the time coming to. All right. Okay, question. Kolo was connected with 100G to the backbone. The backbone had 100G and we had 400G outgoing capacities. So, in theory, capacity was there. Right, question out of space. Will there be a presentation about the alien wave and the test? So, the sponsors, who did that test with us, they have prepared a presentation. I think they are planning to publish that and we might even publish it and that will contain a lot more facts. So, yeah, I suggest follow our Twitter account and then we can upload this presentation. Number four. Or two. What is it? So, the question is about the local network. What tools are you using for automated switch configuration? We have, well, for the configuration itself, we didn't have any tools at all. We had tools for generation of the configuration. So, basically, the configuration would be applied manually, but the configuration itself would come from self-written Python-Tools, which would generate the necessary configuration from our IPAM. Thanks. Great. Here. Sir, please. Map of all the access points. Yes. Can you upload it? Can you upload it? We can probably make some screenshots. I'll talk to the Wi-Fi guys, who have it in their controller and see if ... I'm not sure, it shouldn't contain any sensitive information, but, yeah, we can look at that. Thanks. I follow you to the anyway. Number seven. So, you allowed arbitrary usernames and passwords in the encrypted Wi-Fi. Did you examine those? And if so, was there anything particularly entertaining? Well, we didn't have any statistics this year, because it was basically the same. I mean ... Yeah, we've done so in the past. You can look it up in our previous presentations. I think it'll be similar. We stopped looking at them because it was funny in the first years. Yeah. I think it's basically the same. There's random stuff, and there's a lot of 34C3 and people cursing. Ration from the web. How many turbos did we upload and download? Have you collected this number this year? A lot. A lot, yeah. So, when we publish the raw data for uplink graphs, someone can integrate that and figure it out. I think we should ... Yeah, we may have time for one more question, but then we should handle the other teams. So, regarding the graphs. Will you publish a history of graphs year-wise, on many previous years? Yeah, we haven't really bothered with saving all of that, and each year it bites us, because we need to do the planning on how much capacity do we need where. So, what we have is the presentations, and we always look up the number of the peak values. We're just one of the reasons we have this fact slide in there to help us with next year's planning. Great, guys. Thank you. Give a warm, warm applause. We made it. Now we take the other, Leon. A bit more exotic network, and we had complete different challenges, but this year we have UMTS 3G. And yeah, the whole mobile network is run with free and open source software, OsmoCom, but there was a bit of a difference between because last year and the year before, it was running quite smooth and stable. We had a bit of experience, and the network was a bit simpler. So, this was how our network and how our setup looked like. But with 3G, OsmoCom decided and had to a bit extend the infrastructure, and now it looks like this. And it was quite new for everyone. So, even for the OsmoCom people, we only used it for a small network with one base station and one phone connected to it. Now we have lots of base stations and even more people connected to it. So, it took a lot of time to run of this. And each of the bubbles is really one demon with one separate configuration file and they all have to match else. It doesn't work. But, even if it looks that complicated, it doesn't require a lot of power.  But yeah, the whole GF7 and UMTS network was on this small box. We had to add some small sort of USB-Dungle because we couldn't log enough of the Codems because the things were crashing. So, this is the central part, the main infrastructure and then you need all the base stations. And this is how they look like. They are quite small. We have generally at every location we have one of the small base stations, the GSM, the black ones. And then the UMTS, the white one. We have them at several locations. We also didn't require, I'll explain more later why, we also didn't require too much power. So, this is the installation. We had a bit everywhere, but most of the base stations were really at the arrival in all room, the GSM room because we needed to debug it and in the hack center and in all of the conference rooms. So, this is what we had. We had seven GSM base stations, five UMTS base stations and they were really running with low power. With GSM we could go up to two watts, but the issue is that we have too many people. And our base station can't handle the load. For every base station, for GSM base station for example, you can only have three calls at the same time. So, if we have more subscribers, nobody would be able to call. It was already quite hard to do some calls. A bit of numbers. So, we sold this year 2,500 cards. Thanks to the POC for taking care of selling the cards. This is a huge task. Although we sold that many cards and you could reuse the cards from past year, only 900 of them registered a token or registered an extension at the POC. Everyone else could use the GSM network because you still get an extension and you still can send SMSes and calls send SMSes within the network but not to decks and outside. For the SMSes actually, we had quite a lot because we have spammers but it doesn't require a lot of bandwidth so we don't really care and let the spammers through. It's not really important. We don't know how many subscribers were there in total or how many calls. We didn't do any statistics because we spent a lot of time on setting up the network. For over the year, one of the pain points of GSM and UMTS is the licenses. You need some kind of license to operate the networks and they are also to the big operators. So, while in the past years we didn't have a license for the Bundesnetzagging Tour this doesn't exist anymore because all the frequencies were sold. So, for GSM, Telecom provided us with three channels. Thanks Telecom. And for UMTS, there's quite a bit of trick because we have US base stations and the US band is not used in Europe. So we just could apply for UMTS bandwidth at the Bundesnetzagging Tour but some UMTS phones were not able to join our network simply because this is a kind of weird band which is not the standard European band. But for all newer smartphones they support this band. It works. The GSM and UMTS network works it took a lot of time to start it because we had to install a whole infrastructure and it was starting with day two was really starting to work. GSM had no data to switch all the time in your phone to where I want to be reachable with voice where I want to have some data because sometimes the wifi doesn't work it's up to you. And there were a lot of crashes but that's also the purpose of trying to operate it here is for us to scale up the whole network because when we use the OsmoCom network or all the software we only have one base stations and one phone connected to it and when we have crashes we just use another phone because we don't want to see why and here we have no choice we have lots of data lots of base stations, lots of phones so we traced all the we have quadrums for all the crashes and we will submit it already some tickets and we will submit a lot more tickets so thanks for pentesting our network now we know how it works so next year it will probably a lot faster changing the IPs and we will fix some things so UMTS is quite new there was no voice for UMTS this will be added there will be a lot more UMTS base stations simply because they are smaller so and we have we have a number of them so we can spread even more of them a bit everywhere and maybe we can have LTE because with LTE the advantages the hardware is readily available so we just lack the software so if anyone wants to play with LTE it's a lot simpler than what I showed with UMTS and GSM feel free to join us and have a talk and then we can maybe integrate LTE with GSM and UMTS and have an awesome mobile network at the next congress and that's it so if there are any questions I'm happy to answer them Are there questions? between the congresses how do you test the hardware and software because you said you need a license from the bundesnetzagentour so you don't always need a license for the bundesnetzagentour this is only if you want to operate on licenses which are frequency which are already used if you want to operate on frequencies which are readily available like bind 5 for UMTS only if you want to provide over the air if you just use cables connect your base stations to your phone using a cable you don't require any license you can also put both things in a faraday cage and this way you don't interfere with the other networks or sometimes you just forget and you have a very very small power and it still works so these are the way to do it great is there another question here well what the test slapper is isn't it it's thank you very much really a last applause before we go over to the next topic thank you very much Leon looking forward to the future ok then it's time for the Vock Review stage is yours audience is waiting thank you very much hello so you may have noticed these guys in the audience with the red telly lights and they and a lot of other people bring your video from the video operations center and I might have some details about that so as you may have we where we try to stream our stuff now there has been a lot of technology in the recent years a lot of technology development as to how ago modern streaming and we tried to adapt for that so this year we had a completely new transcoding setup which allowed to basically have one matroshka internal sort of format where we have the video format the three languages so we had three languages in most talks which was awesome and we had a completely new way of playing out the signal in different ways in HLS this time the first year round also with Dash we even could make this 4 day 2 so during operations there were no big problems with that but we had adaptive playing so when you had low band with it would automatically degrade to slide only and audio then to SD and finally and I hope you could all enjoy this thanks to the knock yeah as I said to translation and additionally for everyone here in the rooms we provided low latency ice cast streams so you could hear the translations on site and finally I think for the first time around we had community feeds and we love them like the fryphone community had broadcasted through our infrastructure we had an OB a unit at our assembly which broadcast through our network and finally we had C3TV which you I hope you took an opportunity watching we tried to replay a lot of old congress content hint it's coming to media CCC soon we got a bag of tapes that was suddenly dropped and as way back as I think 9C3 let's see eventually it may emerge on media CCCDE and this was a great sneak peak at this point yeah we hinted to that last year we said we might do 4K because why not so we did as an very experimental setup this time we used the hardware mixer there but we learned a lot of stuff concerning the delivery and the specialties of 4K streaming let's see what next year brings we got a bit of fancy new hardware because without hardware we are geeks it's fairly boring so we rolled out our own layer 1 network on site so that we could not transport us to the external locations we had a layer 2 to the data center to Berlin thanks to the knock and this will allow us to tear down most of the stuff here and have the last talk transcode in the data center so hopefully the talks that are in the end of today will be available to you much sooner than in the recent years and finally next to the 4K streams we had Voktomix in all rooms so our own software defined mixer and we also took the opportunity this year not just this event but over the year to open source all of our components that are required to setup the stuff yourself including Ansible recipes so go do your own stuff use the stuff in your assemblies we want to take on a lot of your assembly streams next year if you want to do this come find us talk to us we are happy to broadcast your stuff great thank you for your fantastic work you're welcome we took we took a bit of we took a bit of well experiments around Voktomix so this year we had camera controls that used the current state of the mixer so these guys can actually see what's going on and if they are alive or not and we had real professional intercoms that were provided to us and this really made it a lot easier to coordinate between camera the guys in the backstage all the mixing so and of course our room in the congress center and for the first time we had an audio control room so what does that mean I mean what we do is not only video but audio so for the first time we have released all talks in stereo so give us reasons please because when we did the slides I was actually and someone said no don't mention anything about this I was like okay why not there's a lot of master people in the audience they definitely have ideas please come find us for why you need 5.1 pardon the other cool thing is this audio control room remotely controlled the hardware mix us in the in the halls and so we had an independent mix that was independent from the PA here and this is really a huge step forward in terms of stream and audio quality because there are simply different things you need for making sure the sound is good in this huge hall and making sure the audio is good in the stream so we could do that and we had real good loudness meters and we tried to hit a target of minus 16 decibel loudness units full scale and this is actually derived from the european broadcasting unions the audio is an audio standard also IP based of course we had casualties encoding and streaming video is no easy business one transcoder died in the process we just sent the remaining to intel we had one encoder throttling CPU Wir haben zu viel Technologie auf den Encodercubes und wir haben gemerkt, dass wenn unsere Monitoring auf 40-something-Schritte ist, nicht gesund wird. Wir hatten ein paar broken Audio-Embedders, aber wir haben noch genug backupchains, um die Situation zu retten. Wir hatten einen Virtualisation-Hos in einem Datacenter, aber wir konnten das auch wiederholen können. So, finally to the part that you like. And I want you to take guesses on each day. What do you think was the highest viewed talk on day one? Keynote and pizza Valhack. Second day was the Arrestwickblick Methodisch-Incorrect on day three. And this is the total amount of almost 7000 viewers. And the pizza Valhack talk had two distinctive peaks. We have no idea what was going on there. Yeah, and what else? I mean, that was really interesting advertisement that popped up during the Snowden Talk. And I tell you, this was totally unplanned for.  And are you really doing this professionally? We tell you, yes, we are professionals. And finally a big hand to our sponsors and to Texak, who was the guy that did all the planning and could be it today. And he did really did fantastic work and to everyone who made this possible. Thank you so much. Questions? Are there questions here? Yes, there, from the web, start with it. The 343 everywhere community would like to thank you very much for making it able to participate in the commerce experience. And they would like to know more about the hardware and software and the vendors that you use for transcoding. So in general, we use donated hardware, we use specific, you know, these small machines that really come in handy because they are really compact and you can easily bring them to events. We also have some, it's usually just standard hardware because everything we built, we built to work essentially on all platforms. So we are quite flexible there. And, well, most of the stuff that actually encodes is FFM-Pack. Right, another question? Still from the web, yes. The question is about the slide stream. Is that a bug or is it intentional that it is such low quality this year? It is, in a way, on purpose, because it's also a way to allow people with, you know, less degraded network connectivity to actually participate. That said, we are trying to make sure that the slides have a certain amount of quality. And that's of course a trade-off. But if you have specific, you know, comments, find us an IRC so we can talk this through. Okay, thank you. Is there another question? Thank you very much for this overview. We still have the part of the assembly to do. First, please to the audience, if you want to leave to Adam, please leave that side. And the other ones try to leave that way because it will be crowded after this lecture. Another message here, there is a call. You know, we have a teardown waiting for us still to go. You know, this is not the last, last bit, but we have to help. So there is a call for angels to do and help in this teardown to make sure that this all ends successfully. Good. Yes, an applause for each other. Come on. Assembly. Im Deutsch. I think again, actually it's not working here. Oh, no problem. Okay, here we go. Hotpatching in alpha, all right. Ja, hallo erst mal.  Irgendjemand hatte gemeint, das ist kein Problem, das auf Deutsch zu halten.  Ich bleib jetzt aber mal bei Deutsch. Wir haben von dieser Halle angefangen.  Da gab es einige nächtliche Planungs-Sessions. Wir mussten uns dann in kürze noch wenige Wochen Formkongress noch mal ein paar Wege umbauen und Ähnliches, um alle Anforderungen gerecht zu werden.  Das nächste Problem, danke. Eine der interessanten Sachen war die Geschichte mit der Anmeldung. Ich persönlich hätte das gerne sehr viel früher gehabt.  Final ging sie dann am 1.11. los. Wir haben sie offiziell bis 15.11. offengelassen.  Wir haben mit der schönen Zahl 256 angemeldeten Assemblies gearbeitet. Nach der erweiterten Deadline haben sich natürlich noch mal weitere Verpeller angemeldet. Und der offizielle Rekordhalter wollte am 26.12. um 14.42 Uhr gerne noch mal so ein paar Tische haben. Die Statistiken gibt es bei uns heute mit ohne Grafiken. Wir hatten so circa 3.000 verfügbare Sitzplätze geplant. 3.500 Anmeldungen hatten wir über das Wikii. Also wir mussten da leider einen kleinen Schäuble polen und mal überall die Kürzungsliste ansetzen.  Aufgrund der Alpha-Planung und so ein paar umgebauten Wegen in der Halle, die eigentlich mal anders geplant waren, ist uns leider doch ein bisschen mehr Platz verloren gegangen. Im Nachhinein aber nicht so ganz wirklich schlimm, weil das Stuhllager ist das. Alles leer, wir haben alles auf der Fläche. Also wirklich nur noch, wer sieht hinten, drei einzelne verlorene Tische, die ich so als Notfall irgendwo mal in der Ecke gepackt habe. Wobei das auch nicht gut so ganz stimmt. Die Messe war so freundlich und hat uns eine Mobiliarliste geschickt und nicht so ganz das geliefert, was da draufstand. Und unter anderem musste ich dann an Tag 2 mal noch ein paar Leuten ihr geheimes Stuhllager zeigen, Tischlager zeigen, unten im CCL ganz versteckt.  Wir werden das jetzt inventarisieren. Was wir dieses Jahr eingeführt hatten, waren die, da gab es ein kleines Naming-Problem. Ich nenne das jetzt mal Centercluster Orbit.  Wir haben davon ein paar größere gehabt, im Vorfeld sehr früh mal gefragt, im Juli. Es kam relativ spät erst Antwort oder Feedback von den meisten. Art and Play habt ihr vielleicht gesehen, direkt, wenn man reinkommt, links, sehr schöne Geschichten passiert. Chaos West mit einer sehr großen Bühne. Kommona mit einigen Workshop-Räumen und einem sehr offenen Struktur. Open Infrastructure Orbit mit viel Freifahrung, viel Internet, einer kleinen Bühne und Workshop-Fläche. Rights and Freedom Center ist leider ein bisschen untergegangen, im CCL in Saal 3. Vielleicht kann man da noch mal ganz kurz vorbeischauen, hallo sagen. Und dann eine groß barben Installation, The Hive durch die Seabass initialisiert, auch mit einigen Bühnen und Workshop-Räumen.  An ganz, ganz, ganz dickes Lob muss sich an das C3-Nav-Team loswerden.  Hey, wo ist unsere Assembly? Und wir konnten sagen, suchen C3-Nav, danke. Wir hoffen, dass das nächstes Jahr ein bisschen runterlaufen wird. Das ist so eins auf unserer Liste.  Liebend gerne aufgerufen, Build More Centers. Für nächstes Jahr tut was, überlegt euch was. Ihr habt gesehen, was hier geht. Wir haben ein bisschen mehr Fläche hoffentlich mal nächstes Jahr. Irgendwo müssen wir mal noch Möbler auftreiben, aber auch das kriegen wir hin.  Ja, war super lieb zu uns. Auch wenn ihr euch im Scheubel-Style doch einiges wegstreichen mussten. Immer mal wieder. Es hat aber sehr gut funktioniert. Dem Assemblies-Team selber natürlich, mit dem ich ganz viel beschäftigt war und allen Aufbauhelfern und Engeln. Vielen, vielen Dank. Great. Thank you very much for this overview. Danke schön. Wie auch so possible in English, if somebody has them. Is there any question? And no, there are no more chairs left, sorry. Oh, the web. Yes, our statistics and maybe pictures available from the kids area. That was not my department. No, the kids base was some kind of a center and self-organized. I can ask the guy if he can make something available, but I don't know yet. I need to ask him. Is someone willing to pay for it or? For the pictures. No. OK, thank you very much. Thank you everybody for this massive event. Great. OK, over to the next step. And that's about translation. Subtitles. Right, which is just taking what is spoken and turning it into words that are displayed on screen. It's not translating. It's just taking the original language and putting that into words. So, right. You might have noticed that this year we didn't have any live subtitles because we just didn't have the time to organize that. And so we focused on what we think is a bit more important and that is having subtitle releases for the talk. And well, so this graph shows the number of seconds of talks in blue and then various stages of subtitles that have been developed during this Congress. So in green are completed subtitles and then we have the yellow ones, which are at some stage of quality control. We have the orange ones that are subtitles currently being timed. So we already have a complete transcript of the talk, but we are still adjusting the timing of when to display which subtitle. And then we also have the red subtitles that is transcripts being written or being corrected. So we're starting from transcripts generated from machine audio recognition techniques and well, those are usually missing punctuation and also contain mistakes. So people have to go through that and basically check that everything matches what is being said. In numbers we have had over 100 Angels working on subtitles throughout this Congress for a total of 336 hours, producing at the point when we wrote the slides, 79 hours of material. So that's about 4.2 hours of work for every hour of material that gets released, which is about the speed difference between spoken word and written text. So, earlier today, when we wrote the slide, we had 16 subtitles released for this Congress. It should be about 20 right now and it's still going on, so more to come. And because there weren't any recordings available for most of day one, we just took subtitles, so talks from last year and started to subtitle those. So, that also got us 10 subtitles for earlier talks. And then we have about 64 hours of material in various stages of being processed. So, we have 30 hours transcribed talks, 22 hours being timed and 12 hours being checked, which probably is also already changed because people are still working on that. So, one of the benefits of having finished subtitles is that you can do funny stuff. So, for example, you get statistics for the speed at which people talk and what words they use the most. This is one talk from last year. I'm not quite sure which one. So, it's about people and bias and language and examples, I'm not quite sure yet. So, it has about 800 strokes per minute, which is not one of the fastest talks we had, but it's still a lot faster than what most people type. And if you want to help make Congress accessible for everyone, then too bad. You can also start writing subtitles with us. It's something you can do the whole year, not just during Congress. Just go to our website and you'll find instructions on how to do that. You can follow us on Twitter. You can come to our IOC chatroom. And you can also follow the SRT Releases Account to just see when new subtitles get released. Thank you. Are there... Great, thank you. So, are there any questions? Is there a question? Okay. None on the Internet? Okay. Hier, microphone 2. Where can you find the subtitles? Right. So, the subtitles are on some link. It's, well, mirrors. Mirror.savnet.de and then somewhere. CCC and Congress and 34C3 and then... Wow. No, not there. Sorry? Pointing up. Yes. Ah, right, yes. Yes, under C3 Subtitles. Yes, 34C3. So, those are currently all the subtitles available. Great. No one else has a question? Someone in the web, maybe? No, not for now. To the next thing, the assemblies. Okay, right, yes. Yes, thank you very much. Give him an applause as loud as you can. Please. Wow. Great, thanks man. Right.


Two of the abducted students of Betel Baptist Secondary School in Chikun, local government area of Kaduna State have been rescued by police operatives. They were rescued on Wednesday evening by police operatives in Rijena area along the Kaduna-Buja Highway. When contacted, the spokesman of the Kaduna State Police Command, Mohamed Jaleegi, told reporters that the two abducted students were taken to a police medical facility where they were currently undergoing medical examination. 121 students of Betel Baptist Secondary School in Chikun, local government area of Kaduna State were abducted from their hostels by bandits on July 8. Last week, the police rescued one of the students inside a forest while two were rescued today, thereby bringing the total number of those rescued to three. Meanwhile, the bandits are demanding the sum of 60 million Naira as ransom for the kidnapped students.


I didn't come from a military family. My like my grandfather's were in World War II and that kind of stuff. Yeah. And you know I was on the uniform side so certainly there were adjustments for me but even the adjusting to military life about life is like on a base and what life is like in that career and for your family and your friends and and that kind of thing that's it's an adjustment so.  I've never I've never known you not to be determined to follow through on something regardless of the challenge. Yes I love a good challenge.


The end of the Cold War completely changed the international security environment. With the demise of the Soviet threat, what was going to be the purpose of the Alliance? Would, indeed, NATO continue to exist, and why? This video will outline the redefinition of the Alliance at the end of the Cold War, while pointing to the main issues that shaped the making of NATO's new role in the post-Cold War era. Following the reunification of Germany in 1990 and the new German state remaining a member of NATO, the debate on the future of the Alliance rotated from the beginning around the issue of potential expansion eastward. NATO expansion, indeed, emerged as a key issue after the end of the Cold War. As US President George H.W. Bush put it, a new world order was taking shape, a new era, freer from the threat of terror, stronger in the pursuit of justice, and more secure in the quest for peace, an era in which the nations of the world, east and west, north and south, can prosper and live in harmony. NATO member countries, far from viewing their mission as finished, sought a new role for the Alliance, a more wide-ranging and active role in the pursuit of peace and stability in Europe and beyond. This test case for NATO's new role came during the Balkan Wars of the 1990s. As war broke out in the former Yugoslavia, the Alliance issued a statement urging all parties to allow the deployment of UN peacekeepers. This was the beginning of a partnership between NATO and the UN in seeking to bring hostilities to an end. NATO then intervened directly in the conflict with airstrikes, authorized by the United Nations. Following the date and accords of 1995, the Alliance first deployed peacekeeping forces, I-S-4, and later a stabilization force, S-4, which remained in the country until 2004. Similarly, when tensions in the Balkans re-escalated in Kosovo, NATO rapidly intervened with an air campaign under UN Security Council mandate, aimed at bringing the violence to an end. A peace support operation, CASE-4, was deployed in 1999 and, under renewed mandate, remains in Kosovo to this day. Clearly, the Alliance had evolved into a new player, seeking to be a force for peace and stability in the new post-Cold War world. Concurrently, the Alliance reached out to non-member states through the Partnership for Peace, launched in 1994. This was and is a program of bilateral cooperation between individual Euro-Atlantic partner countries and NATO. It allows partners to build up an individual relationship with NATO, choosing their own priorities for cooperation. The Alliance's new role was clearly spelled out in the new strategic concept of 1999. The year of NATO's 50th anniversary, Allied leaders adopted a new strategic concept that committed members to common defence and peace and stability of the wider Euro-Atlantic area. It was based on a broad definition of security, which recognised the importance of political, economic, social and environmental factors, in addition to the defence dimension. It identified the new risks that had emerged since the end of the Cold War, which included terrorism, ethnic conflict, human rights abuses, political instability, economic fragility and the spread of nuclear, biological and chemical weapons and their means of delivery. The broader and more global role played by the Alliance was reflected in the successive enlargement rounds, starting in 1999 when the Czech Republic, Hungary and Poland became members of the Alliance, and with an even greater enlargement in 2004, when seven more countries entered the Alliance, NATO almost doubled its membership of 1949. Far from being an alliance in demise, NATO was becoming bigger and bigger and seemed to have a growing importance in the post-Cold War era. The significance and continued relevance of the Alliance was confirmed in the immediate aftermath of the September 11, 2001 attacks on the United States. Confirming the unity and purpose of its members, Article 5 of the North Atlantic Treaty was invoked for the first time in the history of the Alliance on September 12, 2001. An attack on the United States was considered an attack against all member states. The fact that the article had never been invoked during the Cold War, but was invoked in 2001, demonstrated that the Alliance was still needed, or perhaps because of a completely different security environment. The successive role played by NATO in Afghanistan, with the deployment of the International Security Assistant Force, ISAF, which remained in the country until 2014, confirmed the redefinition of the Alliance to include missions outside the territorial scope of the Alliance. The out-of-area dilemma which had plagued NATO during the Cold War had been resolved in favour of an acknowledgement that in the future, NATO had to act outside the Euro-Atlantic area to protect the territory of its member states. The crisis over the annexation of Crimea in 2014 refocused NATO on its more traditional purpose of deterrence and defence in its core territory. The crisis caused the most significant reinforcement of NATO's collective defence since the end of the Cold War, plus confirming that while the new and more global role of the Alliance was a defining feature of NATO's new role, the core mission of defending the Euro-Atlantic area remained at the centre of the Alliance's priorities. Alliance cohesion, particularly given the size of the Alliance, currently at 29 member states, as well as balancing the need to go out of area without undermining the defence of NATO's core territory, are among the main challenges the Alliance faced in the post-Cold War. Moreover, given the successive enlargements eastward to include in the Alliance countries formerly in the Warsaw Pact, raised issues on the uneasy relationship with the Russian Federation. Difficulties that had remained hidden and subdued until the crisis in Crimea dramatically brought them to the forefront. The future of the Alliance will rotate around the delicate balancing of these crucial issues. Alliance cohesion, balancing in and out of area commitments and the relationship with Russia.


Greetings and welcome to this course orientation for popular culture in the U.S. I'm Lance Eaton, the instructor here at North Shore Community College and I'm really excited to teach this course. I find popular culture to be such a fascinating topic. I hope that you will too as you kind of go through the course and learn the different things that we are exploring in this course. So what is this course? It examines popular culture in its many forms in media. You have the opportunity to assess, explain and analyze products of popular culture by connecting them with the overall cultural values, norms and ideologies. We get to explore issues related to popular culture such as consumerism, mass media, technology, viewer participation, etc. And really through this course you become better communicators and interpreters of cultural products. And really it's just a very fascinating and intriguing course. That being said it's also a fairly rigorous course. People think popular culture is effusive, is irrelevant, but we take the topic very seriously here. We do have fun with it. But it does require you to think and analyze to a degree that you might not realize the course is intended to do. So you're going to be challenged in this course and you should be challenged in this course. This is your education. And like every other college course you should expect to spend nine to twelve hours a week of work on this course. Between the course lectures, the discussions, the different assignments. So one really great thing about this course is there's no textbook purchase required. All the readings are made available online in our course shell. And we do watch three films, which I don't require you to buy the films, but you do need to get a hold of them. You may be able to find them online or you can use them for in-library use at the Danvers campus. Those films are Tales from the Crypt, which is a documentary. It's not the TV show. Bamboozled, but I'm a cheerleader. So what do you do in this course? What are some of your assessments and activities? The first is introductory material. That's just material to get you up and started, get you into the course in oriented so that you can do the best throughout the semester. You do an article analysis, which is essentially a review of an academic article. You do discussions each week and we really have some fun, interesting prompts for you to consider and for you to play around with the course materials. You get to blog about popular culture. While we're running a course blog, you'll be able to interact with other students and potentially other people in the world who may be coming to look at what you're saying and what you're doing. Finally, we have what is popular culture project and this is a very fascinating and interesting project that we'll be doing in chunks throughout the semester. So announcements. Announcements really are an important piece of this course. Every time you log into the course, you really want to go to the announcements and see what's being updated. I send out a good amount of announcements. They're just things to be aware of, reminders, reflections on what we've been doing, clarifications about what's been said. So it's a really, really important place to go pretty constantly. You want to be, every time you go into the course, which should be a couple, four to five times a week, you should be going in and checking out the announcements. The course information section, this is everything you need to know about how to succeed in this course. The syllabus course outline, assignment guidelines, all of those things are there to really make sure that you have all the information so when it's time to do the assignments, when it's time to engage in the coursework, you know what is expected of you. The learning modules is where all the content is. Each week will be a different module and that module will have a set of things within them for you to kind of go through a different, you know, a set of information, a set of actions, activities, etc. Every week we have discussions and as I mentioned before, these will be really quirky, interesting, dynamic discussions. And then there's also an open discussion. Whenever you have, you know, you want to share something about popular culture, a new observation, a new understanding, that isn't related to that week's module and its theme. Then you can go to the open discussion and share that out and interact with other students around that. One big thing I really emphasize is that there, you know, you really want to succeed in this course. One of the things you need to do the first is just don't underestimate the course topic. It's an important topic. It's a powerful topic. It's a complex topic. We won't just be describing what Justin Bieber wore to the Emmys. It really is about trying to make sure we understand what goes on as we engage in popular culture. Remember the five rights, which is get the right assignment into the right place at the right time in the right format with the right editing. You really do want to make sure that you follow the directions. I try to make them clear.  With all of your assignments, you really need to connect your thoughts to the course material. Popular culture is a very, very easy course to just shout out opinions all you want, but those opinions need to be grounded and based upon the course material. It's the only way I know that you're actually looking at thinking about and considering the material. Very, very important. Always ask questions. We're going to be seeing some interesting things. We're going to be seeing some confusing things. We deal with theory in this course. That's hard. If you need clarification, if you need help, please, we have a questions forum. Always, always, always ask questions. And on that forum, you can ask them anonymously. If you're afraid of how asking that question may look. Honestly, I love when students ask questions. It helps me to know that they need some help. It helps me to know that I'm not doing my job effectively and should do my best to clarify. And finally, plan for technological failure. It will always happen. This is a course that's entirely in a technological environment online. You really need to make sure you have those backups. Do you have a second computer that you could regularly access if your shuts down? Are you saving your assignments in different, you know, in more than one place?  Really make sure you use or you plan for technological failure because it will happen. So each week, as you get into the module, there's a series of things you need. Each module, there's a series of things you need to do. Typically, modules include objectives and topics. My thoughts, the instructor's thoughts, an assignment listing, additional readings that maybe require supplemental, the discussion forum, your blog post prompt, and then the open discussion forum in any assignments that you might do that week. So you really want to get in there and for each module, you should, you know, read that module, those topics and objectives, read the learning guide, review the read, watch the course readings and videos, fully participate in the discussion, post the course blog, and then on the weeks that are relevant, submit reading selections for the next week and perform any additional assignments. If you're having technical help, you really want to reach out to the help desk at northshore.edu. If you have questions or problems with Blackboard, you want to reach out to Blackboard Learn Help Desk, which is BBlearn at northshore.edu. And if you have questions about the course, you really should be asking, you really should be reaching out to me or be using that questions forum. So you can reach out to me at leaton at northshore.edu or go to the questions forum. In terms of communicating with me, email is the best way. However, if you need to contact me by phone, you can contact me. I have my number up there. I will take texts. You just need to make sure you identify who you are, what class you're in and what your need is, and I'll happily respond. Typically expect about 24 hours turnaround time. It's usually less than that, but just, you know, that's the standard. And if I don't respond within 24 hours, then please send it again. And on the weekends, it might be, you might have to expect to wait a little bit longer. All right, first day of class, when you come into the course, you really should go into that module one, read all the material there, read all of the course information. You want to post your introduction to the Introduction Discussion Board or the module one discussion board. Post a comment on the questions forum, take the syllabus quiz. You have to get 100 for that in order to get credit. Activate your library account, upload the academic honesty assignment, register on the blog, post your first blog post, and look at what's coming up next week. It sounds like a tall order, but these are all the things that you're doing that first week. So the more of them that you can chip away at, the better you're set up to succeed in the class. So there's a lot of stuff that I just went over. I don't expect you to process it all right now. I do expect you to kind of keep coming back into this course during the first week, getting yourself oriented, getting the materials, understanding what you need to do, what you need to plan for in order for your class to, in order for you to succeed in this class. And then finally, once you finish with this orientation, please email me a note that you've completed it. Subject line should be pop culture orientation. And also ask any questions you might have at that time. All right, that's all I have for now. Thank you very much for watching and see you online.


When I first bought my house, it was the first house that I bought, I hated it for like six months and the reason why was because I was worrying about it all of the time and I was thinking what if something goes wrong with it? What if it cost me like $50,000 or $100,000 and I have to clear off my savings and it was just a stressful thing of owning a house and And then what I realized is I was I was driving down the street there was a homeless person on the side of the road and he was holding up a sign and I thought about it and I realized that if everything materialistic was taken away from me if I lost my house if I lost my car if I lost everything at stuff for the clothes that I'm wearing and I was on the side of the road and I was holding a sign No matter what happens all of the materialistic stuff can all be taken away the one thing that can never be taken away from me is the knowledge that I've gained over the past 31 years the 10,000 hours that I put into myself of just trying to make myself better reading Speaking going out and talking to people that can never be taken away from me And so no matter if I were to lose every single thing that I've ever had and thought that I loved about You know materialistically I could I could still get it all back if I wanted to Which really like took all of the stress away of and worry away of what if I lose everything because I was like Oh, I can gain it all back and then what I also realized was this is probably the reason why some people become millionaires They make a mistake they lose all of it but then they get it all back it's because That materialistic stuff can be stripped away, but what made them become a millionaire the Knowledge the mindset all of that stuff the thing that made them become a millionaire can never be stripped away They've already learned that and so it really gave me a lot of Peace and calm knowing that if everything materialistic if I lose all the money in my bank account if I lose my house If I lose everything I can always get it back because the one thing that can never be taken for me is is my personal growth and Everything that I've done to become the person that I am


So this is a joint work with a former PhD student, Luca Benini, who was also a student of Paul Bourgade. And this is about some nonlinear random matrix ensemble. So let me briefly give the plan of this talk. I will first explain where the question we consider come from. And this comes from some new old network questions. And then I will give also some previous existing results. And then I will turn to our results, which is more in random matrix theory and give some ideas for the proof. Okay, so the main motivation I said for studying nonlinear random matrix ensembles comes from new old network. So in this setting we consider an input column vector X, which is our input data. And then the data goes through a first layer of a new old network. So this is a combination of both linear and nonlinear functions. So this is here the linear part, which are given by two p times n matrices. And what is important here is that there is an activation function f, which is applied point-wise. So to each entry of the vector. And it is here to reinforce some neurons. So I give here the example of what is called the relu function, which means that there is a special which is zero here and the which the neuron is not activated. Okay, and then, so you obtain like this an output vector and you can consider multi-stage architecture for a network. So this is just alternated layers with both linear and nonlinear such functionals. So in artificial neural networks, the thing is as follows, you are given say two data sets X and Y, X is the input and Y is the output. And you want to learn the synaptic weights, which are the matrices W1 and W2. So there are different ways. You can try to learn. So I'm using for instance, some gradient descent. I need also to say that the activation function is not unique and there actually one of the problem is to choose the activation function. So one commonly used is the relu function and for some reasons I don't, I cannot explain because I don't understand. It accelerates learning but there is a problem which is that the process can die in the architecture and there are some other examples which are the sigmoid function or some other function. So if one wants to understand how such neural networks work one possible way is to make them random. And this has already been done. I will state in the next slide some results from Roman Couillet and other sources. So the idea is that the weight, the synaptic weights are given by large dimensional random matrix with IID entries. Okay, X, which is the input data set is still deterministic and again it's high dimensional and the output is the random matrix which is given by when we apply the function f point wise to WX. Okay, and so the idea is as follows. So we are given say an input matrix which is a piece sample of photographs with NL and so there are photos of cats and we want to identify the breeds of the cats. So the idea is from the output try to approximate the correct breed on the photo and so the training set comes with D times P matrix which is the target output which is the correct breed for each photograph. Okay, so to do that because we are in the high dimensional setting we commonly use procedure is to use a real machine commonly used procedure is to use a rich regression which is reconsider this approximation for the target matrix Y and the aim is to minimize the error remake when estimating say Y with this matrix Z. Okay, so you try to minimize a loss function. If one makes some computation one can then show that the optimal B here which has to be determined can be expressed like this. Okay, and then what is interesting is that the learning performance can then be expressed in terms of the empirical eigenvalue distribution of a sample covariance matrix which is M star M divided by P. This is a usual covariance matrix, okay? Okay, so this question has been investigated in a series of paper by Roman Couillet I said and for the question in the preceding slide they have shown the following they have actually identified the limiting empirical eigenvalue distribution of this sample covariance matrix. So they consider a sub Gaussian matrix W. F is Lipschitz continuous function and all the dimension grow to infinity at the same speed, okay? So that the ratio are all bounded. So then they show that the limiting empirical eigenvalue distribution of the sample covariance matrix often to rest as the same limit as another spectral measure I will say. So which is given by it's still just transformed here. So this is a equation. I will just explain in a few words. So one important parameter in this equation is the matrix G bar which is the expected value of our sample covariance matrix. And actually this equation has already been encountered in random matrix theory since this is a deterministic equivalent for the limiting empirical eigenvalue distribution of sample covariance matrix with non-identity covariance. Actually if you consider a matrix T such that T, T star is equal to G bar then the limiting spectral measure of M star M is almost the same as T, X, X bar, T bar, T star, sorry. Okay? What is interesting in their result is that the dependence in the activation function is actually hidden in this matrix G bar and it's non-universal. Actually they have shown that there is quite a strong dependence on the first moment of the entries and they use it to study the performance of neural networks. Okay? And they also study a lot of other questions for this model. Okay? And then there is another model which has been proposed by Bennington and Voram who consider the fully random case. So this time the input data set is also random and the weights are random and they consider the simplest case where W and X are Gaussian random matrices. So for ease they are centered on variance one actually they consider a more complicated case where the variance of W and X is something different. So I state the simplest result and the output data set is also random. So we consider exactly the same question. We consider the non-linear matrix F of W X divided by square root of N and the associated sample covariance matrix. Okay, so you're given an input data set, the output, there is a loss function. Okay? I'm coming to this question. You try to minimize the loss function. Okay? You find your optimal B and then the expected value of your loss function can be a measure of your performance and it is expressed in terms of the empirical eigenvalue distribution of this matrix. Okay? And what they show is the following. So there exists a limiting distribution, a limiting empirical eigenvalue distribution provided the ratio of the dimensions of X, W. This ratio converges to some constants. Okay? And they obtain a fixed point equation for the still just transform, which is a quadratic fixed point equation. So the way they prove it is based on some more or less explicit computations because W and X are Gaussian. We can use some analytical tools and some, actually they compute the moments of the spectral measure and use a subtle point argument. Okay? And this was done for Gaussian matrices and actually they describe the limiting spectral measure using some graphs which we could not really understand. So we try to understand how they obtain this result using some more general models than Gaussian random matrices. So the model we consider with Luca is again some random matrices W and X. And we don't assume that the entries are Gaussian but we need some decay assumption here on the tail of the entries. We also consider a class of real analytic functions. I don't give here the all assumption, all the derivatives of F grow at most polynomially on the compact sets. And the important thing is that F is centered with respect to the Gaussian distribution, the N zero one distribution. Okay? And we make the same assumptions, the ratios of the dimension converge to some constants as n goes to infinity. Then we obtain that the limiting empirical eigenvalue distribution of G converges to the same distribution mu F as that of Pennington and Vora. Okay, so I will try to explain what is this distribution mu F. So actually the dependence in F is in two parameters which are theta one. So this is the average of F squared and theta two which is the expected value of F prime to the square and the expected value is always with respect to the Gaussian distribution. Okay, and so this is the variable aquatic equation for the still just transform of mu F. So I will not discuss here this equation. What is important is that the dependence in F lies really in these two parameters, theta one and theta two. And which means that the limiting distribution mu F is universal in this fully random setting in contrast to the case where X was deterministic. Okay, some more now the limits of the ratios here. So what is important is if theta two is zero, mu F is the Marchenko-Pastore distribution. And the other external case is when theta two is equal to theta one. And in this case, the measure mu F is the same as that of a linear random matrix model, WX divided by square root of N. And in the other cases, this is some kind of interpolation. I will come back on this later. Okay, so this could be of interest for applications to neural networks. And this was actually already a question in the article from Pennington and Vora because this can help to determine the activation function. The Marchenko-Pastore distribution is a good limiting distribution because it means that there is not much distortion between the output and the target data sets. A few simulations. So the first one corresponds to the case of where there is no special choice for the parameters theta one and theta two. This is a generic case. The second case is the Marchenko-Pastore distribution. So theta two is equal to zero. And the last one is when theta two is equal to theta one. So we get a linear random matrix ensemble again. And if in addition, the largest, sorry, F is bounded, then the largest eigenvalue sticks to the support of the distribution mu F. Okay, in all cases, the support of mu F is compact. I didn't explain that. Okay, another possible description of this limiting distribution mu F. So because I said this is some kind of interpolation of two linear models. The Marchenko-Pastore one and the product reshort case. So actually one can show that this is a real is a case. So I need to introduce another random matrix C, which is just Gaussian. And W and X here will be again Gaussian random matrices. This is not important for the limit. Then one can show that mu F is also the limiting empirical eigenvalue distribution of an information plus noise sample covariance matrix. So, okay, how can I explain this formula? The information plus noise matrix is Z plus A and Z plus A star. Okay, so you just replace, so Z is Gaussian say, and we just replace A with a product reshort matrix and simply the weights on each part of either Z or A depends on theta two and theta one. Okay, so this result is related to the three convolution which has been already studied by Florent-Bénage. And this is also some kind of similar to the result of N-Carouy who studied the kernel matrices. Okay, and because we are interested in more than one layer, we can consider, I just gave the limiting empirical eigenvalue distribution when there is one input and one output and one goes through one layer. So we would like to consider more than one layer. Actually, we can only consider a fixed number of layers, so at each step we introduce some new random matrices for the rates, so the matrices WI which are independent and they satisfy the same decay assumption as before. And we form the output matrix at each step, except, so we start from the output at layer L minus one and we again consider the output data set except that we normalize here the matrix so that at each step the variance of M is one, okay? This is what is called batch normalization. And we are interested this time in the limiting empirical eigenvalue distribution after step L of our network. So we studied only the case where theta two is equal to zero and F is in addition bounded. And then we can show that at each step, the limiting empirical eigenvalue distribution is the Marchenko-Pastore distribution. Okay, so this finishes the results. All this has been conjectured by Pennington and Vorra. And one of the main problem here that we cannot push L to grow to infinity, okay? This would be the interesting results. Okay, so I will now give some ideas for the proof. So this is a simple moment method and we start with a case where F is polynomial and the easiest case is when F is an other polynomial. So we want to compute the moments of the spectral measure of G and we do as for Wigner's theorem, we develop the whole trace in terms of W and X. Okay, so there are a lot of indices, I, J and L. And because we assume that the matrices W, X are independent, and the entries are independent, we need each entry to arise twice. So we will need to find a way to encode such a cement in order to see how one can compute the moments. Okay, so I and J indices will play a different role than the L indices just, let me explain, because the J and the I's are necessarily repeated, okay? So we encode the cement in the following way. So we first assume that all I and J indices are by rise distinct. So this means that we can draw the I and J indices on a cycle of lens two Q and the blue vertices on this cycle correspond to an L index, okay? And if there is a label L here in this niche here, I want J1, this means that I read W, I, L, X, L, J1 in my expected value, okay? Okay, now I have this constraint that each of the W and X and three need to rise twice, so I need to match the blue points. And the basic idea I would say is that we want to maximize the number of pair rise I, J, L indices, so if I assume that the I and J indices are pair rise distinct, I will try to maximize the number of L indices. And if I want to do so, one can check that the good way to do it is to match L indices inside niches, okay? But then I told that K, the number of blue points inside the niche is odd, so I cannot obtain a perfect matching inside the niche and I need to add a cycle which necessarily has to go along the whole cycle, actually, okay? So this is the case where Q is bigger than one and if one wants to determine the number of ways to perform a perfect matching and also to determine the cycle, so in each niche we have K possible choices for the vertex in the cycle and then a perfect matching for the K minus one remaining blue indices and this gives the parameter seated two, okay? The last case is when Q is equal to one. So in this case we get a simple cycles of lens two and two K blue points which can be matched, matched actually without considering niches and this gives this time the parameter seated one, okay? So now if I remove the assumption that INJ are distinct and I make some identifications, we can obtain in this way cycles of lens two or longer cycles and we can then show that those graphs which contribute in the limit are those for which they are called actually cactus graphs so which mean that one can see them as a tree of cycles, okay? So the black graph is okay but if I add an INJ, I can see them as a tree of cycles, okay? Graph is okay but if I add an identification here, this is not a contributing graph, okay? And so this is my black graph on the INJ indices, a tree of cycles and then inside each cycle so that it contributes in the limit. A typical matching is as before which is if the cycle has lens greater than two, we have a full blue cycle and perfect matching it's inside niches so this gives a seat that two and if the cycle has lens two, we will obtain a contribution of seat that one, okay? So in the end, we obtain this formula for the moment of the probability distribution Mu F, called AQ, this quantity actually is the number of cactus tree, cactus graph sorry, which have been obtained using a certain number of identification and similar for J and with B cycles of lens two, we obtain this formula for the moment of Mu F, okay? And we have done this computation for an odd monomial for the moment but actually the dependence in F is only in seat that one and seat that two if and we recover the expected properties so if seat that two is zero, we obtain the number of fat trees and if seat that one is equal to seat that two, say equal to one for ease, we simply get a sum over the cactus graphs, okay? And then we can do the same for even polynomials and due to the fact we assume F is centered with respect to the Gaussian distributions, this means essentially that we ban perfect matchings inside niches so we need to match blue vertices from one niche to another, at least once. So for long cycles, this will give a negligible contribution and only cycles of lens two will contribute in the limit, okay? And then we go to arbitrary polynomials and the extension to our class of activation functions simply follows from a Taylor approximation, okay? For the largest eigenvalues, this is simply we can push the argument up to Q in the order of log n. So we don't know exactly where the top edge of the support is but the largest eigenvalue cannot exit the support under our assumptions, okay? And I will finish with the extension to multiple layers. Just in the case of two layers, I will just give the ideas, this is far from approved. So after the first layer, our output is matrix M1 so this is different from X because its entries are not independent, okay? So the idea will be to come back to independent matrices. So again, we assume that the I and J indices are distinct and we consider the output after layer two. We cannot say anything about matching the entries of M1 because they are not independent so we simply match the W and trees and consider the induced. So if I match this and trees, this will mean I will forget about the I indices and I consider the induced graph on J and indices, okay? This will give me some moment to be computed, okay? And we can show that the graphs which contribute in the limit are such that, okay, so the green edge will be important here. So there is a single edge linking two niches adjacent to the same I vertex, which is a bridge. Then we can make identifications between bridges. So in the end, this may result into a JL graph which is not connected. And the remaining edges inside the niche match according to a perfect matching which gives here what we call flowers. Okay, so there are K minus one flowers at each step. And when you multiply layers, you multiply at each step the number of flowers. Okay, as a conclusion, so this was a way actually to understand the result of Pennington and Var, because they gave these graphs and we could not understand where they came from. So this works for the fully random case. If W is deterministic, we get nothing interesting. It doesn't work either for f of x. If x is a Wigner matrix, one of the main problem is that it doesn't work for the most commonly used function which is the Roulou function. But for some others which are simpler. And what is funny is that if we consider complex, I didn't say matrices are real, but if we consider complex matrices with the usual assumption that the expected value of W IL squared is zero, then we only obtain a March and Goubert's tour or product result limiting distribution. Thank you for your attention.