Put the streamers, inflate the balloons, and pour a glass of champagne. This is episode 25 of my eShop Games Worth Buying series, meaning that I have found on the eShop, downloaded, played, enjoyed, reviewed, and then edited for you to see. With 10 games in each episode, today we're hitting 250 games. That's just a lot of games. I want to thank all of you for watching these videos, watching my content. Thank you to today's sponsor, which we'll get to, for helping me afford to buy this many games. Because you gotta remember, for every game I enjoy, there's two or three I downloaded to try and didn't like. There will definitely be something that you'll want to download and try today, so let me know what your favorite is down below. You can even suggest a game if I haven't talked about it yet. And do I have to say it? And a very early hair flip on that subscribe button. And let's get started. From our friends at Devolver Digital, and yes, I do mean that Devolver Digital, Today is only the beginning, comes Boomerang X. Harness the power of a mystical Boomerang to fling yourself through the air, slicing down arenas, swarming with evil creatures, similar to doom, staying agile and constantly moving is key. As soon as you start to slow down, you're going to get overrun with creatures both small and gigantic. Oh, and when I said friends at Devolver Digital, I meant it. They even sent over the Boomerang from the game. Maybe because I'm Australian, they thought that I would need it, little stereotypical, but you know, don't really love being stereotyped, but it's a cool Boomerang. It says on the back that they only had 50 made, and I have lucky number 13. I really appreciate owning one of the 50. That's pretty cool. Thanks. I really love the flow and movement of Boomerang X, which is good because that's 95% of the game. The game is strictly linear, moving location to location, triggering waves of enemies. It's all about how fun, fast-paced and furious the action is. There's loads of different abilities to use in combat. Obviously, you can just throw this bad boy, but you can also charge it up for a longer shot, and you can instantly recall it at any time, or you can force Paul yourself towards the location of the Boomerang. I use this all the time as my movement around the arenas, getting the advantage of enemies, or just getting out of the way of an attack or for platforming. If you kill multiple enemies with one throw, you get a special ability you can trigger at any time and wipe out entire hordes at once. The variety of enemies is what makes each wave so unique and exciting. Many creatures have specific ways of being killed, like a frog who hides its weak spot on its stomach, or a massive giraffe thing that has multiple spots that need to be destroyed. It's all about timing your moves and abilities, getting control of the battlefield, and staying in motion. Once you get good at the game, you'll spend like 95% of your gameplay in the air, just flying around and killing things. It really is just you and one Boomerang, but it never feels repetitive. And that's good game design. Eugene, back at it for a third time trying to hack your system. Your Express VPN keeps blocking me, but thankfully I developed this. It's a computer program so advanced, not even Express VPN can handle how robust and intense, and oh no! How? Egypt? You know the drill.  Using the internet without Express VPN is like building several giant pyramids. Why would you do that? Express VPN will protect you at home, at work, or anywhere online. Other than your own security, there is a fun side to Express VPN too, like with Netflix and gaming. Streaming services have a ton more content that's regional, but you can take your Express VPN and just put yourself in Australia. And now you have a bunch of new shows to check out, like Rick and Morty or Brooklyn Nine-Nine. And with gaming, you can use it with Steam, for example. When games release, you can download them a whole day earlier, if you're in Australia. Try it out by going to expressvpn.com forward slash beat em ups and find out how you can get three months free. Bet it was aliens. I love when I can feature a $5 game in one of these videos, and with Islanders, I can do just that. It's a relaxing minimalistic strategy game about building cities on colorful islands. It's pretty simple. You start with a small randomized island and choose what you want to build first. You have the freedom to put anything wherever you want, but certain buildings or objects will earn you higher points if they're placed close to or far away from other things. For example, houses and mansions will get a bonus for being close together or near the town center. Sawmills will get a bonus for being close to trees, but will also lose points for being too close to another existing sawmill. Once you get enough points, you can either keep building on the island or move on to the next one in your playthrough. It's all procedurally generated and the goal is to rack up as many points as possible before game over. Then you start again and try to build more and get further next time. It's just so easy to pick up and play with bright visuals and easy controls. It's simple, sure, but it's $5. The devs were even nice enough to reach out to me and send me a code without me asking, but they also sent over an extra one and said it was for Kim if she wanted one too. No one ever does that, so I really appreciated that. It was super nice. So as far as I can tell, the Slime Rancher Portable Edition that just dropped on Switch is the full Slime Rancher experience just on the Switch. It's a little confusing because calling it Portable Edition to me sounds like it's a lesser or downscaled version of the full game. I could only compare it to something like Final Fantasy XV Pocket Edition, but this is the full game. It's even running at 60 FPS and has all the DLC. So not only is it not just a portable edition of the full game, it's the definitive edition. I get the devs were going for a play on words with plot-able as plots is Slime Rancher's in-game currency, but you have to have played the game to get that joke. Maybe I'm overthinking it, but I just worry a little bit that this will scare off potential buyers. Anyway, so now that we know it's the full game, I highly recommend giving this one a shot. It is the perfect game to have portable. Slime Rancher is a little Stardew-y meets Pokemon-y. You play as Beatrix living light years away from Earth on far, far range. Here there are strange and adorable creatures known as Slimes. There's pink slimes, exploding slimes, rocky slimes, and my favorite, the cute little cat slimes. Sorry, I like cats. Actually, there's loads more too, but the fun is getting out there, exploring and finding them all yourself. You'll grow your range as you add more slimes to it and feed them, because once you feed them, they'll poop, and their poop are called plots. Yes, some of you have already put this together. Plots, again, is the in-game currency, so you pay in poop, poop, money.  Different types of plots will be worth way more than others, so that's your motivation to get out there and find all the rare slimes and keep them nice and fed so you can make it rain that sweet, sweet dookie money. There's a sequel to this indie gem on the way, so play the first one now. Okay, Dreamscaper is exactly why I am so glad that Kickstarter exists. This one took me by surprise. I was given a code for it, I downloaded it, and then it just sat there on my Switch for weeks. The icon is kinda boring, I gotta be honest. But then there I was on a Twitch stream and we decided to just find out what it was, and we all loved it. Dreamscaper is an endlessly replayable action roguelike, and if you liked games like Hades or Dead Cells, you're gonna love this too. By night, you delve deep into your subconscious, facing nightmares in an ever-changing world filled with unique items, abilities, and challenges, with these intense and brutally difficult boss battles at the end of each level.  There you can explore the city of Redhaven, build relationships, and unlock permanent upgrades in order to take on the next dream, stronger than ever. The gameplay loop of playing, earning, upgrade materials, dying, then using those materials to grow, jumping back into the game, stronger than before is as addicting as always. You know, I used to think I would never like games like this. The idea of permadeath and loops never interested me, and it's the weirdest thing, but I think it's becoming very clear that this style of game has grown on me, and now, they're some of my all-time favorites. I think it says less about me, and more about the genre itself, having developed and evolved its formula into something really quite impressive. The amount of sheer possibilities in each run, mixed with the satisfaction of absolutely crushing a boss fight that used to wipe you out in one hit. It's an adrenaline rush so exciting, it's almost impossible to not keep giving the game just one more run before you stop. The art style is beautiful, and I vibe with it so well. The soundtrack is magical, and adds so much depth to the world. The combat system is deep, rich, and expansive, rewarding skilled players for mastering positioning, timing, and quick reflexes. There are so many different weapons from bats to yo-yos, and then you have these crazy magical abilities in ranged combat. The combinations and variations just seem limitless. I wish I could go back in time and help support its Kickstarter. It's unbelievable to me that they did all this on a $52,000 budget. That's nothing for a game. I could have become an NPC in the game for $2,000. Is it too late for that? Devs, hit me up. We'll figure something out. Look, I know my audience like I know the back of my switch. Oh, actually, I can't show you that yet.  You play as Concord, a small grape entrusted with the huge responsibility of rebuilding the community and defending it from an unknown force called The Rot. Garden Story is fairly similar to Stardew in the sense that it shares crafting, building, and combat elements. However, where Stardew was mostly focused on the crafting side, Garden Story leaned much harder into the combat, giving you multiple weapons to switch between while battling different types of rock and even throwing big, awesome boss battles at you. A really interesting system in Garden Story is Memories. Along your journey, Concord will form memories of its closest friends and fun moments, or when you complete certain tasks or goals, like the amount of hits taken from enemies. Once unlocked, you can equip the memory to increase Concord's stats or to give buffs. At the start, you can only equip one at a time, but as you progress, you unlock up to nine memory slots. Each memory has a description of what caused it, so not only do you get rewarded for doing more things in the game, but they also act as a great way to look back at fun moments gone by. What's kind of weird though is the whole gardening side of the game doesn't really play a part in the story. Weird for a game called Garden Story. It's not until the tail end that you start to dabble around with planning a few crops and trying to figure out how to craft some stuff. The battling really does take up the focus of the main game, but once you wrap up the story, you can focus on whatever you want. Elder Souls is, shockingly, a Souls-like game. The name might be a bit boorish in that regard, but it's actually more of a case of the developers showing appreciation for From Software's games and the clear inspiration that went into this one. In fact, this is Fallen Flag Studio's first ever game and that in itself is quite impressive. Uh, thankfully, for me, the combat is fast paced. Personally, I'm not a fan of how slow and clunky some Souls-like games can be. This is much quicker while still having things like the stamina bar that depletes as you dash around or use light and heavy attacks. There's three different classes you can choose between an upgrade. Each suit varying play styles, but you can respect them at any time. So there's no harm in trying one out on your playthrough and seeing if it fits. While you're out exploring the world, you'll come across side quests and a cast of unique characters to interact with. But no other enemies or creatures throughout the land. This game is strictly a boss rush experience with these crazy, tough and ruthless boss battles one after another and they are tough. I gotta be honest, I didn't finish this one. Just like with most of the Souls games, I decided my life was better spent doing other things, but I don't make these lists just for me. I make them for you. And I can still tell a fun game when I play it, even if I don't have the stomach for it. The pixelated art style is done wonderfully. The character and bosses look incredible and the world itself is haunting and mystical. I can tell that a lot of you are gonna love this one. That's why it's here. It's called being unbiased, okay? Moving on to something I do love, dodgeball academia. Dodgeball academia is a fast-paced sports RPG set in a world where dodgeball is life. And we will, we will rock you. First up, this vibrant and drawn art style is fantastic and the reason I was drawn to the game in the first place. I mean look at it.  The game is narrative driven, set in a dodgeball school. Yes, a school just for dodgeball. With a large, lovable and charming cast of characters. Look at all these guys. Don't you just need to get to know each and everyone? I really enjoyed the writing, which was nice because there's a fair bit of reading, but there's also a lot of dodgeball playing. It's a real-time dodgeball battle. You have a special bar you can charge by catching balls or just by powering up Super Saiyan style. There are different kinds of dodgeballs too. Ones that drain health or slow speed. Enemies can throw balls at varying speeds too, but none of that is as distracting as cars racing across the match or any of the many other field hazards that pop up game to game. It always felt fresh, doing its best to throw new twists and turns at you all the time. As far as the RPG mechanics, you got a leveling system, a bunch of different party members, equipment, side quests, the whole shebang. I can almost guarantee that somewhere down the line, limited run games is gonna take this, snatch it up, and turn it into a physical release because it just has that vibe and it's a great game. Um... Calculator is a unique Nintendo Switch title that has you using the Switch screen or your TV as a giant calculator. The point of the game is to do math. If you press one of the number buttons, it will add that number into the text field. Then, by pressing other commands like plus or minus, you can add or subtract other numbers respectively.  So be honest though, many of the controls went over my head. I still don't know what the atan or kosh buttons do. The game never really told me and I'm not sure how you win the game. There seems to be a high score system, but I keep accidentally wiping mine by hitting this C button. I guess you guys give it a shot multiplying some numbers together at home and let me know how big you can get your high score. To be honest, I much prefer the sequel. Battle calculator. This one's even pricier at $15, but at least here we have multiplayer. One to four players wait for a number to appear on the screen, then try to be the first person to make that number. It's great stuff, but I gotta say the visuals here are a serious downgrade from the prequel. Really not sure what happened there, but either way, please don't buy either of these. A fantastic switch port always needs to be appreciated because it's so rarely done right, but in the case of Strange Brigade, they nailed it. It's a very arcadey co-op third-person shooter for up to four players and death better playing with a friend or few, but you can still play it solo and have some fun. Each character has a different special ability and starting weapons together. You blast through waves of the undead, mummies, minotaurs, and giant boss battles. You explore the maps, fighting and exploding things as you go, finding puzzles that are actually really fun to solve. Some are relatively easy, but others were real brain teasers. The more optional puzzles you can solve, the more you're rewarded with hidden treasure and upgrades. We always look forward to the next big horde area where you can trigger the wave and it locks you into the location.  I gotta tell you, it's really fun to play. The controls are great, it feels smooth, and there is so much variety in the levels. Laying on Xbox, I can tell you this game is shockingly gorgeous with some expansive, stunning views and vistas, beautiful shadows and reflections.  But they kept a solid 30 FPS while also keeping a lot of those shadows, reflections and lighting elements. Overall, it looks fantastic. They even managed to get tons of the undead swarming your switch at once without too much drain on the system. I honestly don't know how they managed to pull it off, but this is just one heck of a game to have a friend or two next to you as you all sit in handheld mode and just blast through waves of the undead while snacking on some munchies and watching a movie. Like, I don't know, it's just a great arcadey hit. Well, I can't do a list of the best indies on Switch without talking about one of the best indies of all time and one that paved the way for all the others to come. Fez. The creation of Fez is a history lesson longer than I have time for today, but if you have time, there's a great documentary called Indie Games The Movie. It goes into fantastic detail about how Fez and other small indie games managed to take over the gaming world at a time when only AAA big budget titles stood a chance. Fez is a puzzle platformer set in both 2D and 3D worlds. You play on the 2D view but you can rotate that view three-dimensionally around four sides. You use this rotation mechanic to reveal new paths through the levels connecting platforms that were unreachable before. How the game was designed and constructed is beyond me and such a marvel to behold. Like, imagine sitting there designing level after level that each works in this rotating space. I mean, no wonder it took five years to develop. The blueprints alone must have taken most of the time. It's hard to even explain the reaction your brain has when you rotate a thin platform around to see a huge expansive area just out of view on the other side. Or a platform that was so far out of reach is now right next to you allowing you to progress even further or maybe there was just a hidden door or vine that wasn't visible from three other angles. You explore the levels looking for cubes to progress in the main game but if you want an even harder challenge you can seek out the optional anti-cubes and those can be a real pain in the d*** but solving those harder puzzles is so satisfying. Fez both created and perfected this weird 2D, 3D style of game genre and it's as worth playing today as it was in 2012. And that is another nine, I mean 10 really great games on the Switch. Even just these 10 games I feel like they're all so fun they're all worth playing like conjoined if you bought them all you have just endless hours of fun not counting ones like Dreamscape which is actually endless hours of fun and it doesn't stop there there's a ton more eShop games that just released and I haven't even had a chance to play them yet. Making these big videos is the only way I can talk about all the great games I want to. I hope you found something that you're gonna play today and I hope you have a good time playing it. Let me know down below like the video if it helped you out subscribe if you want to and I guess here's to another 25. All right, bye. Oh and uh click the link in the description and support the sponsor of the video. Thank you.


Why is coastal security an important agenda for India's growth? Numerous cases of smuggling, gold, narcotics, explosives, arms, all occurs through coastal areas. Thus safeguarding the coastal areas becomes very important. In this context, the Indo-U.S. Coast Guard Joint Excise, Abhiyas 1 bar 22, was held off the Chennai coast. The focus of the excise is to familiarize the personal off-coast guards with each other's capabilities. This will strengthen the working relationship between the forces. It will enhance interoperability in the area of maritime search and rescue. It also helps in maritime law enforcement duties. One such highlight is hijacking of a vessel was created and the subsequent rescue operation was conducted in a coordinated operation. With this goodwill visit, the U.S. Coast Guard Qatar John Midget ended and to know more about the India-U.S. relationship, click the link in the description.


In the last few lectures, we discussed about the inelastic seismic response analysis of structures. We started with the inelastic seismic response analysis for single degree of freedom system. Then how it is extended for a multi-degree freedom system was discussed. After that, we discussed the effect of the bilinear interaction on yielding and how it is included in the inelastic seismic response analysis of structures. The concepts were then utilized for the analysis of 2D frame and 3D frames. In 2D and 3D frames, we considered again 2 cases. In the first case, the beams were strong and columns were weak. Therefore, the plastic hinges that occur, they are in the ends or at the ends of the columns. And we generally assume the beam to be rigid in the sense that we make the frame a shear frame. For the case when the beam is weak and the columns are strong, then the plastic hinges are formed in the beams. To treat that case is relatively easier compared to the case when the columns are yielding in the case of a 3D frame because they are one has to take into consideration the effect of the bilinear interaction on yielding. Only thing that is to be considered for the case of weak beam strong column system is that after the yield has taken place at a particular cross section in the beam, then from the incremental displacement, we have to compute also the incremental rotation. With the help of that only, we can find out the bending moment at a particular cross section and check whether it is exceeding the value of mp or not. If it exceeds the value, then another thing that we have to compute is the what is the rotational velocity at the plastic hinges and also the amount of rotation. After that, we discussed a very important topic called the pushover analysis in earthquake engineering. The pushover analysis is a very good equivalent static non-linear analysis of structures for earthquake. With the help of pushover analysis, we try to understand the inelastic behaviour of the structure after the yielding during the earthquake and also try to see the performance levels of the structure at different stages of the earthquake loading. And pushover analysis is extremely used for most of the cases where we have a situation where the structure is subjected to a lateral dynamic loading and because of that, the structure goes into the inelastic zone. After this, we want to discuss now two very important aspects in earthquake analysis and design. They are the ductility and inelastic spectrum. I have defined what ductility is before. So, let me define it again. Ductility is for a single degree freedom system is defined as the maximum displacement that the structure undergoes during earthquake divided by the yield displacement. So, that is the definition of the ductility or in other words after the yielding, how much the structure can deform is a measure of the ductility. And in seismic design of structures, we design the structures to have enough ductility. I mentioned this in connection with the design philosophy that we have. In the seismic design philosophy, we have got three very important criteria that is the stiffness, strength and ductility. So, stiffness provides the resistance to the earthquake forces in the elastic zone. The strength denoted by the yield of the yield resistance of the element that decides when the element goes into the inelastic range. And ductility denotes how much the element can deform beyond yielding. Ductility detailing of reinforcement is a very crucial issue in the structural drawings. At every joint, these structures must be detailed properly for earthquake. And so far as the reinforced concrete structure is concerned, there are guidelines given in all codes how one can provide the adequate ductility by way of reinforcement detailing. So, we will look into this aspect of ductility in earthquake resistant design of structures. Along with that, we will discuss another important aspect in earthquake resistant design that is the inelastic response spectrum. And we will see how inelastic response spectrum differs from the elastic response spectrum that we have discussed already. How one can construct an elastic response spectrum from the elastic response spectrum and what are the uses of inelastic response spectrum. As I told you, a structure is designed for a load less than the load which the structure experiences during the design earthquake. And how the equivalent static lateral load is calculated using seismic coefficient method or response spectrum method of analysis. For both cases, the load that is computed or the base shear that is computed is divided by a reduction factor R, so that the effective loading on the structure is reduced. The typical values of R that are considered is between 3 to 4 for ordinary kinds of structures. For different kinds of structures, however, the code specifies the values of the reduction factor that is to be taken. Because of this reduction factor, a reduced load is acting on this structure and we analyse the structures for that reduced load. As a result of that in the case of the actual earthquake, all the structures that we design, they undergo inelastic excursion that is it goes beyond the yield limit. Different elements go into the yield limit to different extent and therefore, there is specific ductility demand which is imposed on the structure not as a overall ductility demand, but a ductility demand which varies from element to element. To cater to all the ductility demands imposed by the earthquake on different elements is very difficult task, but we try to assess what is the ductility demand as such on the structure and for that push over analysis is one of the very important analysis technique by way of which we convert a structure into an equivalent single degree freedom system and look into the ductility demand imposed on that equivalent single degree freedom system. This is done by way of considering that the structure as if is vibrating only in the first mode, but that gives us an idea about the ductility demand and that is imposed on the structure as a whole or because of the earthquake. For finding out the ductility demand for each element, one has to carry out a non-linear dynamic analysis or a non-linear seismic analysis of the structure, find out the maximum displacements or deformations that take place in individual members, divide them by the yield deformation or yield displacement and find out the ductility for each member. So, we want to see now how this ductility is obtained for a structure element wise as well as a single degree freedom system or what we call as overall ductility of the structure. The structure will undergo yielding if it is subjected to the expected design of earthquake and that is what I told you before. The behaviour will depend upon the force deformation characteristics of the section. So, that is one of the again important input for the analysis. We have to provide the load deformation behaviour for each of the elements of the structures that is the cross sections where we expect the plastic hinges to form. For those cross sections, we provide load deformation characteristics or moment rotation characteristics from the designed cross section. The maximum displacements and deformations of the structure are expected to be greater than the yield displacements and that gives rise to the concept of ductility. However, there could be situation where the maximum displacement or deformation in a structure may become less than the yield displacement. That kind of scenario can also happen. How much the structure will deform beyond the yield limit depends upon the ductility? Ductility factor is defined as the equation 6.35a that is mu is equal to xm by xy where xm is the maximum displacement and xy is the yield displacement and this is defined for a single degree of freedom system. For explaining the concept of ductility and understanding how one can understand the effect of ductility on the structure, we consider two single degree of freedom system. One is a elastoplastic system, other is a corresponding elastic system. So, that is shown in this figure. So, this is one system that is the elastoplastic system. The corresponding elastic system is this one. That means in the elastic range both of them has the same stiffness but for the elastoplastic system after the yield force, the system moves on this horizontal line whereas in the elastic system it continues to move on this same inclined line representing the stiffness of the system. We have these definitions of the displacement here. Say xm is the maximum displacement that can take place in the single degree of freedom system, xy is the yield displacement that is well defined with the help of the yield force and the stiffness of the system and x0 is a displacement for a force of level f0 applied to the structure or the single degree of freedom system and it is assumed that the single degree of freedom system is behaving as a elastic system. So, beyond yielding in an elastic equivalent or a corresponding elastic single degree of freedom system, the value of x0 will be obtained through the stiffness of the system and we will have for a particular value of f0 the displacement as x0. In order to make the formulations and the necessary curves for understanding ductility, we make certain parameters or introduce certain parameters into the analysis procedure. First parameter is a bar y, a bar y is a non-dimensional yield force defined by f y divided by f0 that is f y is the maximum force that can occur in the elastoplastic system and f0 is the maximum force that is developed if that particular x0 system were behaving as an elastic system and this is equal to xy by x0 which is shown in earlier figure. So, this f y by f0 will be equal to xy by x0. Now inverse of f bar y is called a factor which may be called as a reduction factor and this reduction factor r y is simply the inverse of f bar y that is r y is equal to 2 means that the strength of the exterior system is halved compared to the elastic system that means this ratio between f y by f0 will be equal to half. Now with these equations 6.35 b one can write down another equation which is given in 6.36 that is x bar xm by x0 that is the maximum displacement that can take place in the elastoplastic system divided by the maximum displacement that can take place in the corresponding elastic system that can be written as mu times f bar y using this manipulation and this can be finally written as mu divided by r y. So, this particular relationship is very useful and will be later on used for drawing certain curves and understanding the meanings of those curves. We can see here that the maximum displacement that takes place for the elastoplastic system divided by corresponding maximum displacement in the elastic system that is finally written as mu divided by r y or the ductility divided by the reduction factor. Therefore, if one knows the value of say mu y mu is given and xm is known x0 is known then one can find out what is the corresponding reduction factor. Similarly, if reduction factor is given and xm and x0 is given then one can find what is the ductility. Now with the above definitions the equation motion of motion of single degree of freedom system is given by equation 6.37 these they are x double dot this is double dot this is a single dot and we write down here since it is not a non-linear system or it is not linear system we have this expression and this expression means that f bar y x comma x that is x dot that is f bar y is a function of both displacement and velocity multiplied by omega n square multiplied by x y where f bar x x dot is written as simple f x dot divided by f y. The entire thing is written in this particular fashion because of certain reason which will be clear little later but here in fact one should have written straight away f x comma x dot that is we have the acceleration we have the damping term and then we have here a function that means instead of writing kx for the linear system one should write down a function of x and x dot which is a general function showing the resistance of the structure at different stages of loading including the elastic phase and the inelastic phase this is equal to minus x double dot g. Now f x y f x dot is a general function one can show that the thing that is written over here is nothing but f x comma x dot so that is shown over here with the help of this derivation if we look at the equation we are writing down the equation we are writing down the equation in this particular form that is f bar y x x dot is written as f x dot divided by f y.  Now if I divide it by x y then the x y automatically goes up over here. So in the denominator we have f y by x y since f y by x y will be the stiffness that is how we are going to write down the elastic stiffness is defined f y is the yield displacement and x y is the yield force and x y is the yield displacement then f y by x y would give the value of k. So this is replaced by a value of k so one can write down omega n square f x comma x dot divided by k since k by n is equal to omega n square then this turns out to be f x comma x dot divided by n. So this entire expression that we have taken thus this expression is simply is equal to f x comma x dot divided by m that is what we should have written over here because we have divided all through by m and m on this side therefore cancels out and the generalized force resistive force restoring force is given by a function general function of x and x dot divided by m. So we deliberately replace this by this particular terms and there is a reason for that. Next we define the value of the mu that is x t over here x t can be written as mu t divided by x y so that is the definition of the ductility at any instant of time t that is how much the displacement can take place over and above the yield displacements. So therefore x t in this particular equation can be written as mu t into x y. So once we have this relationship then this can be substituted into the function of the top equation so that the second equation can be simply written in terms of the not x variable but mu as a variable that is ductility at every instant of time t.  Now this a y is defined again in this particular form a y is equal to f y by m or in other words m multiplied by a y that gives the value of f y or one can say this as if it is an yield acceleration a y yield acceleration multiplied by m gives you the yield force and that can be shown to be is equal to omega n square x 0 divided by f bar y. So this proof again is shown over here in this derivation that is we write down first a y to be is equal to f y by m and this is then manipulated like this f y divided by f 0 multiplied by f 0 by m. So this is equivalent to f 0 by m and this is equivalent to f by multiplied by f bar y further we write down f 0 by x 0 into x 0 into f bar y divided by m. So we multiply here by x 0 and divide by x 0 then it turns out to be now f 0 by x 0 is the stiffness of the elastic system corresponding elastic system. So this becomes k and this is m so k by m becomes omega n square so a y can be written as omega n square x 0 multiplied by f bar y. So that is what is shown here that is a y is equal to omega n square x 0 f bar y. So the equation 6.38 which is written in terms of the ductility as a variable so that is now is this equation now has the following variables omega n, xi and f bar y. So if we wish to now solve this problem that is equation 6.38 we see that mu is the value depends upon 3 factors omega n then xi and f bar y because ay will contain f bar y so that is what we have shown over here. If we now want to find out the value of mu by solving this equation 6.38 the value of mu obviously would depend upon not only frequency and the damping of the system but also by f bar y that is inverse of the reduction factor. The time history analysis for the second equation shows the following important things. First for f bar y is equal to 1 that is the elastic system responses remains within the elastic limit and may be more than that for f bar y less than 1. f bar y less than 1 means that f bar y is less than 1 means the elastoplastic system. For the elastoplastic system that is f bar y 2 counteracting effects takes place first is the decrease of response due to dissipation of energy and increase of response due to decreased equivalence stiffness as the single degree of freedom system goes into the inelastic range. There is a dissipation of energy because of the hysteresis loop that is formed because of the force deformation behavior of the system and second is since the system goes into the plastic state or inelastic state is equivalent stiffness is decreased thus one can see that the first effect tends to reduce the response of the system the second effect tends to increase the response of the system therefore it is very difficult to say whether in the inelastic range the oscillation will be greater or less than the corresponding elastic system. The less the value of f bar y more is the permanent deformation at the end that is obvious because of the more value of f bar y means that the system is having more inelastic effect. Therefore at the end of the earthquake episode we observed that the system has undergone some permanent deformation element wise as well as overall structure. Next mu is known if x m for a f bar y and x 0 can be calculated so that is that follows from the relationship that we have shown before that means this important relationship given by 6.36 equation so it from this equation one can say that provided we know x m f bar y and x 0 one can calculate the value of mu that is one of the equation emerging out of that equation.  So this particular relationship is very important and we will use this relationship later for explaining many figures effect of time period on mu x m x 0 and f bar y are illustrated we on this figure we can see that we have the on this ordinate we are plotting x dot 0 divided by g 0 and divided by x 0 divided by x g 0 and this is x m divided by x g 0. So any one of them are plotted over here that is the normalized displacement elastic displacement and the normalized value of the maximum displacement for the elastoplastic case and this is a on this scale we have got time period the scales are logarithmic scales. The curves are plotted for different values of f bar y or in other words for different reduction factors r y f bar y is equal to 1 that denotes the elastic case and all other denote the inelastic case or elastoplastic case we divide this entire range into 3 ranges that is the displacement sensitive range this is the acceleration sensitive range and in between we have the velocity sensitive range that is for large value of t we call this as a displacement sensitive range for the low value of t we call this as the acceleration sensitive range and in between time periods we call as the velocity sensitive range these definitions and the meaning of them are discussed when we are discussing the tripartite plot for the response spectrum. Now from the figure the following observations can be made first one for long periods that is in the displacement sensitive range zone we find that x m is almost is equal to x 0 or is equal to x g 0 and this the value is independent of f bar y we can see that the here in this particular zone irrespective of the values of f bar y the all the values are more or less the same and here the this is equal to 1 that means x m is equal to x 0 is equal to x x g 0 and therefore in this range the mu simply is equal to r y in velocity sensitive region x m may be smaller or greater than x 0 or greater than the x 0 value and is not significantly affected by f bar y mu may be smaller or larger than r y so we can see that again from the curve this is the velocity sensitive range that is the in between region from here to here and in this range we can see that the value it is not very sensitive again to f bar y and the ductility can be less or more for different values of f bar y and then this range is the acceleration sensitive range here we see some interesting things that is in the acceleration sensitive region x m is always greater than x 0 increase with difference decreasing f bar y and t mu is always greater than r y for shorter period mu can be also very high so this is seen here one can see that in this particular range the values of x 0 divided by x g 0 or x m divided by x g 0 they are very sensitive to the values of f bar y for and we can see that different values for different values of f bar y these ratios non-dimensional displacement ratios they are widely different and specially these difference increases for shorter time period mu value is greater than r y value over here that is one of the important observations the x m by x g 0 plot is separately drawn over here so that we have discussed already in the previous curve next we come to with this understanding of the ductility we come to the inelastic response spectrum or the definition of the inelastic response spectrum and how one can construct the inelastic response spectrum we will see that the inelastic response spectrum and the ductility factor are close related in fact the inelastic response spectrum are drawn for specified values of mu which is a difficult task but we will see that how we can obtain this inelastic response spectrums for a given earthquake let us first try to define the inelastic response spectrum d y that is the displacement response spectrum or displacement inelastic response spectrum is simply is equal to x y that is the if we plot x y that is the yield displacement over entire time period then we will get the displacement inelastic response spectrum similarly the velocity inelastic response spectrum or pseudo velocity inelastic response spectrum is defined as omega n times x y and the way we did for the pseudo velocity spectrum in the case of the elastic response spectrum and acceleration inelastic response spectrum is equal to omega n square into x y that is the displacement inelastic response spectrum is multiplied by omega n square like we have done in the case of the elastic response spectrum. So the plot of these quantities can be made against t n and that would give us the elastic response spectrum we can see that because of the relationship that holds good between d y v y and a y they can be plotted in a tripartite plot like the elastic response spectrum. So that is a very advantageous thing because we will see later that if we know the elastic response spectrum of a single degree of freedom system drawn on a tripartite plot then from that one can obtain inelastic response spectrum for different values of the ductility factor mu for a fixed value of mu and xi plots of d y v y and a y against t m are the inelastic spectra or ductility spectra and they can be plotted in a tripartite plot that is what I told you. So here the parameters are that the mu and xi these are the two parameters which control the inelastic response spectrum as against the elastic response spectrum where we do not have the concept of mu attached to the spectrum only we have the damping ratio xi attached to the spectrum. However mu is equal to 1 and for that if we plot the spectrum then it will automatically become the elastic response spectrum. The yield strength of the elastoplastic system can be written as f y is equal to m into a y that is the yield acceleration multiplied by mass that we have described before yield strength for a specified mu is difficult to obtain but reverse is possible by interpolation technique. So that is a very important statement we want to define the response spectrum for a specified value of mu. However it is very difficult to find out what is the yield strength for a specified value of mu but the reverse thing can be done because of the equation that we had formed before and that was the intent of writing down 6.38 equation. That is converting the x x dot variables into mu mu dot variables. If we solve this equation for different values of a y or different values of f bar y then these for different values of f bar y we can get different values of mu. So that is why we have converted the 486.37 equation into the form of equation 6.38. So for the yield strength is known provided f bar y is known because f bar y is defined as f 0 divided by f y we have seen before. Therefore the yield strength can be immediately obtained provided the value of the mu is known. So what we do is that we go for interpolation technique and an iteration for a given set of T n and xi we obtain the responses for the elastoplastic system for a number of f bar y values. That is we solve the equation 6.38 for different values of f bar y and find out the values of the mu. Each solution gives a value of mu and f 0 is given is equal to k into x 0, x 0 is the maximum displacement of the elastic system. That means the same equation can be solved also considering it to be a absolutely elastic system. So for the same earthquake one can solve the single degree of freedom system considering as if it is a elastic system. So that will give us the value of x 0 and correspondingly one can find out f 0. From the set of the values of f bar and mu find the desired mu and the corresponding f bar y. So if we have a number of combinations of f bar and mu from that one can find out the desired value of mu say for mu is equal to 2 or 3 or 4 what will be the corresponding interpolated values of f bar y. Then what we do that interpolated value of f bar y and the mu this interpolated value of f bar y now is used in the equation 6.38 and it is solved and the value of mu is obtained. And if we find that the value of mu that we have interpolated and the value of mu that we are obtaining from equation 6.38 if they are same then we say that a convergence has taken place otherwise what we do through iterative process we find out the values of f bar y and mu. So through some iteration process one can get a value of f bar y corresponding to a given mu value. So once we know that then it is possible for us to obtain the values of the x y then a y and the d y and the v y or v. So the in the last section we have elastic acceleration in elastic displacement in elastic velocity they can be obtained provided we know the value of in displacement and to know the value of in this in displacement we must know the yield strength and to know the yield strength we must know the value of f bar y. So what we do is that for different values of the time period T n we repeat these entire exercise and we plot the ductility spectrum. So a ductility spectrum which is the acceleration ductility spectrum is shown over here it is not m it will be is equal to mu. So for mu is equal to 1 that means this is the elastic response spectrum. So mu is equal to 1.5 mu is equal to 2 mu is equal to 4 mu is equal to 8 we can see the accelerations or inelastic accelerations and these inelastic accelerations for different values of the mu value is plotted here and one can see that for higher values of mu the value of the spectral acceleration is drastically reduced compared to the elastic response spectrum. So as the system goes into the inelastic range and the effective force that is coming on to the system gets reduced. From the ductility spectrum yield strength to limit mu for a given set of T n, T n and xi can be obtained. So that we can see over here in this particular curve the f bar y and T n that is plotted over here for different values of the mu. So their mu is equal to 1.5 mu is equal to 2 this is not m. So they will be all in mu equal to 1.5 or 2, 4, 6, 10 so on and for this we have these curves plotted and these curves are nothing but f bar y plotted against T n and that is the aim that we had. So for a given value of mu we can find out what is the value of f bar y. So once we do that then you take any time period and for a specified value of mu one can immediately get the value of f bar y and once we get the value of f bar y then from there we can get the value of f y and once we know the value of f y we can get the value of x y and once we know the value of x y then the inelastic response spectrums are defined because the displacement inelastic response spectrum will be equal to x y simply. The velocity inelastic spectrum will be x y multiplied by omega n and the velocity inelastic acceleration response spectrum will be equal to omega n square multiplied by x y or d y. So that is how we finally obtain the value of the or finally plot the spectrums inelastic spectrums for given values of mu. So let me summarize here what we do and then we will proceed with it for constructing the values of constructing inelastic response spectrum. So what we have done over here is that we have essentially solved equation 6.38 for different values of f bar y assumed and each f bar y value provided a value of mu and that is how one can have a collection or a collection of the combination of f bar y and mu for a particular time period t n and xi. Once we have that then from there we say we are wanting to construct the response spectrum inelastic response for spectrum for mu is equal to 2. So we find out from interpolation what is the value of f bar y corresponding to the value of mu is equal to 2 from the set of values that we have got after the analysis. Once we know the value of f bar y then that from that f bar y one can find out the value of f y and once we know the value of f y then one can know the value of x y and inelastic response spectrum ordinary for that particular t n and xi combination is known. So that is how the inelastic response spectrums are obtained.


Merci pour l'introduction. C'est la ligne de l'enjeu. Je vais commencer avec quelques mots d'introduction. Je vais essayer de motiver le sujet, expliquer pourquoi je pense que c'est important. Puis, décrivez ce que je veux dire par l'accès à l'accès à l'accès à l'accès à l'accès à l'accès à l'accès à l'accès à l'accès à l'accès. Et le reste de la taux sera principalement expérimenté. Les simulations, le software protégé, les hardware masques et la conclusion finie. Alors, c'est une histoire. Je pense que c'est une picture que vous savez plus ou moins. C'est un DPA standard. C'est ce que nous faisons quand nous essayons de récover des informations par exemple de l'exécution de l'exécution de blocs cypher. On a un XBox à la première phase. Donc, un XBox à la première phase. Et bien, si vous regardez ces attaques, ce qui est important, c'est qu'il y a beaucoup de détails. Donc, typiquement, vous avez besoin d'une sorte de measurement et de pré-processing, pour que vous achetez de données que ce soit informatif que possible. Et puis, vous avez une sorte de prediction et de modélisation, qui est essentiellement où vous essayez d'arriver quelque chose sur les valeurs internales de votre implementation et de connecter cela avec les liens physiques. Et puis, il y a usually un phase d'exploitation qui est essentiellement comparé à toutes vos predictions avec les liens actuels que vous avez mesurés. Et cela vous donnera des informations sur le subkey. Et si ce n'est pas suffisant, et ce sera le prochain talk, vous pouvez faire post-processing et commencer à faire l'immigration ou l'estimation de l'exécution de blocs cypher. Et dans ce talk, je vais juste vous concentrer sur cette petite partie, qui est la modélisation de la fonction physique. Et je vais d'abord essayer d'arriver pourquoi je pense que c'est important. Et pour ce purpose, je pense qu'on peut commencer par cette notation, qui est la modélisation. Et ce qui est important ici, c'est que quand vous regardez cette modélisation, vous avez un peu de hypothèses que nous faisons. L'une est explicite. Nous faisons une hypothèse sur le key. Et c'est ce que nous voulons récover. Mais il y a un peu d'assumption implique sur le modélisation, sur comment l'exécution physique. Et bien sûr, si nous voulons extraire toute l'information, ou si vous êtes dans l'évaluation de l'app et vous voulez faire une bonne évaluation, vous avez besoin d'une modélisation idéale pour être parfaites, pour que vous puissiez vraiment avoir le maximum perfect, la possibilité d'attaquer. Donc, comment nous dealons avec ça? Pour les clés, c'est facile. Quand vous faites un attaque, vous essayez de les mouler. Parce que c'est généralement un sub-key. C'est quelque chose que vous pouvez tester. Mais je dirais que si vous pensez sur le modélisation, c'est beaucoup plus difficile. Comment pouvez-vous essayer toutes les modèles physiques pour votre implementation? Et ça, je pense, c'est plus ou moins à un point que Matthias Wagner a donné quelques heures auparavant à Cosez, où il a dit que vous avez toutes ces attaques que nous avons publiées dans la littérature et qu'il n'y a pas de manière d'évaluation de l'app, toutes les modèles. C'est juste trop long. Donc, nous devons trouver un moyen de restricter ça. Et ici, essentiellement, nous essayons de contribuer un petit peu à ce problème. Nous essayons de trouver un moyen de ne pas essayer toutes ces modèles physiques mais un couple de plus rélevants. Et bien sûr, si vous faites ça, vous pouvez dire, ok, c'est bien en théorie, c'est une bonne question mais peut-être, ce n'est pas le cas que nous avons un bon modèle et je voudrais argumenter que ça se passe tout le temps. Et je pense que c'est facile de voir. Chaque fois que vous avez un modèle qui s'exprime mieux que l'autre, c'est exactement la situation où nous sommes. Donc, c'était un exemple où j'ai ploté le succès de l'attaque qui était juste une combinaire S-box mais en ce cas, c'est bien, c'est bien, c'est bien, c'est bien, c'est bien, c'est bien, non mais China un rapport qu'on entend, c'est bien, c'était domicile pour la sortage, osoique et aimant, c'est bien, c'est bien. Donc, directional d'였습니다, il est fait, c'est bien. La ascense à tes active� si ça pollutionera, on va se faireathi elevenagert mais si tu prends quelque chose de masque, si c'est juste la preuve de stock, probablement la distribution de liqueur n'est pas juste de Gaussian. C'est une mixture de Gaussian, c'est quelque chose d'autre. Donc, encore une fois, pour être sûr, le modèle est bon. Et si nous pensons que c'est un modèle bon enough, nous pouvons d'abord nous demander ce serait le modèle optimal, et c'est exactement ce que nous ne trouverons pas en réalité. Donc le modèle optimal serait la situation où j'ai une distribution bleue, c'est la chose que je ne sais pas. Je n'ai pas d'analytique formulaire pour ça, mais c'est quelque chose que je peux mesurer. Et je vais utiliser le mot sample. Vous pouvez sample la distribution, obtenir de nouvelles mesures, mais vous ne savez exactement comment ça fonctionne. Et c'est votre modèle estimé en red. Le modèle est parfait, si votre modèle estimé correspond à la vraie distribution de liqueur. Donc, comme je l'ai dit, ce n'est pas going to happen, car nous n'avons pas cette distribution bleue, donc la théorie pourrait dire que ce modèle est epsilon close to optimal if some statistical distance between the estimated model and the true distribution is bounded by epsilon. And in fact that would be very nice. If we had that, that would be extremely convenient because this epsilon would exactly tell us how much do we lose in terms of information or eventually in terms of success rate if we don't use the optimal model. Problem is we didn't change much because I still don't know this blue chip distribution so how can I compute the distance between an estimation and something I do not know. It doesn't look easy. So that was the problem or essentially what we tried to solve with this certification paper. And I think the key idea that we tried to exploit is if we want to see something about this issue we need to distinguish two types of errors that we can have in the model. One is estimation errors you just don't have enough measurements and one is assumption errors. You assume your distribution is Gaussian and it's not. And of course we call that estimation errors they are relatively kind type of errors because this is something that always decreases if you measure more. And now I'll just try to give you some intuition why this distinction between estimation errors and assumption errors tell you something about whether your model is good or not. So imagine this is... Right? So this is a true leakage distribution and this is something we do not know. It's in blue. But what I can do is I can build a model for that and then I can sample the model and the true chip distribution and I find something like that after N0 samples. So in red we have the model samples in blue you have the true chip samples and I'm asking you whether this model is good in predicting the chip. So I don't know for you for me or essentially I don't know why because at this point my number of samples is not sufficient so what happens here is estimation errors dominate and what this tells you is usually you just need to measure more. But if you do and you take N1 samples that are much larger you will eventually end up with this type of thing so my red curve is my Gaussian assumption for the model. The blue curve is my true leakage distribution and I think it's easy to see here what the model is is not exactly predicting what we have so we lose information and that means really if you have this situation you need another model because it's likely that you lose significant amount of information so what's nice is that this reasoning tells us more or less what we could define as a good enough model and essentially it's a model for which the assumption errors are small in front of the estimation errors given the number of measurements that you made. Ok, so concretely how does it work essentially what we will try to do is more or less the same as previously but the very important parameter is this N here. It's essentially telling whether the model is good I'm not able to do but telling whether the model is good given a number of measurements that I make this is now possible so I do the same I'm going to do that taking advantage of cross validation which just means I try to make efficient use of my measurements so each time I take most of the samples to build the model one part of the sample to test the model and I will just do cross validation to exploit all the samples for testing and eventually the important thing is we will output a p-value that depends on N and as usual a small p will indicate that most likely the model that we are looking at is not correct and I think that's pretty much what we want and the very cool thing is that this N it's the evaluation lab limit if you're an evaluation lab and you tell yourself I have money to make one week of measurement this is your N, you have one week of measurement but given this week of measurement you want to be sure that you exploited this information properly and that's what we do here you build a model and you test whether the model is good enough it will never tell you the model is perfect and most likely the model is still incorrect what it tells you is that if you have only one week of measurement you can try to improve the model but it's useless because all the improvements that you can have they will be hidden by estimation errors anyway and there's of course a drawback the big drawback of this approach is it's extremely expensive because we need to characterize all the sampling distributions of the model so doing this approach was quite long at least that was the main criticism that we got so we tried to find a way to simplify this and doing it in a completely sound manner is not very easy so easy certification very simply stated that the idea that we wanted to use is rather than comparing distributions which is long and difficult why not comparing moments and then it's very simple I have my estimated model I pick up n samples from this I estimated a moment of order D I pick up n samples which means I measure n times I estimate the moment and I test the quality between these moments so what is good the big plus is it can be done with very simple univariate tests that probably everybody in the diodens has been using, typically t test if you make a Gaussian assumption or something you can go for higher order testing of the moments but given the number of samples that we usually have this is probably good enough the big minus obviously is this theoretical sound, no because it exists you can find two distributions they are different but their moments are exactly the same so is it a problem I would say maybe conterexamples that we are aware of they look quite involved and I'm not sure they exist in the literature or they will correspond to what we have in practice also if you look at what we do concrètement, most of the time that's exactly what we do we do leakage detection, higher order attacks and that is just based on estimation of the moments which is not a good reason maybe the approach that we use at the moment for our evaluations are not completely sound and we should question ourselves but at least this gives some incentive to look at that ok so as usually when you have something that's not completely sound the best thing that we can do is to look what we can learn out of that that's what we did first with simulations so how does it look this is a simulated example on the top of the figure you have in blue, the sample distribution so this is a chip that we simulate and in red we have a biased model here it's very easy to see you have an error in the means what do we see here on the second line the estimation of all the moments we see that indeed the means are different on the second line the p-values so this guy is telling us very rapidly impossible that this model is actually predicting the true chip distribution because we see there's a big difference in the means and we can do that for the variances we can do that for the skewness we can do that for the kurtosis what's interesting is of course it easily generalizes to mass implementation because typically this type of Gaussian mixtures that we have here this is what we would observe if we have masking ok that's simulation still not reality so the next step was to look at what happens for real and first on protected software because that's exactly what we did 2 years ago at your crypt so we wanted to repeat these experiments and we looked at again and protected a yes implementation in a very kind at Mellivier microcontroller and this is what we get so these figures they are pretty much like the p-values figure so I'll just explain the upper left one this is for Gaussian templates and for the beam the y-axis you have 256 values and these are the 256 templates that we built if we try to attack the output of the s-box so these are our 256 models and the x-axis is the number of measurements that we used in the evaluations and in this case we made an evaluation of 56,000 measurements what do we see is not much for the mean, not much for the variance and that's pretty good news because that's essentially what we concluded 2 years ago Gaussian templates were good enough in explaining this particular implementation and we had a problem with linear regression because with a linear basis the model was not good enough and here again we see clearly big errors this model is not good, we need to change it so good but maybe less good or surprising at least if we look at skewness and kurtosis then we see there's a little bit of something but at some point it seems that for some of the templates we don't predict the full distribution nicely so that's annoying because typically it could be inconsistency between the previous approaches and the simplified one which is totally plausible one case we compare full distributions we are sound in this case we just estimate moments so it's a much simpler problem and we were wondering what happens here and what we wanted to do at this point is of course to say ok maybe we have an error in the skewness or kurtosis but maybe there's just nothing useful in these statistical moments so the question becomes do these errors lead to something and to answer that what we did is an additional test based on something very simple again which is moments correlating DPA so I guess you all know CPA where you do correlation between the mean values and your actual leakage moments correlating DPA you do the same but higher order so you correlate higher order statistical moments with leakage samples here squared to a certain power raised to a certain power and the cool thing in general with correlation is that we have this nice metric intuition the number of samples that you need to attack your implementation is inversely proportional to the square of the correlation coefficient so what do we have first look at the top figure this is the value of the moments correlating DPA for the mean for the variance, skewness and kurtosis and good news we see there's very little information in the skewness and the kurtosis which seems very reasonable for un protected implementation but now we see it the results of your report 2014 so that's nice what we have on this figure is exactly the same moments correlating DPA with Gaussian templates and linear regression the only difference is that the moments are the ones that are produced by these models and here it's nice as well because we see now okay we saw that there was a problem with linear regression and indeed we see that the amount of information that I have in the mean values produced by linear regression is less than the one of the template attacks and obviously I also see there's a little bit of information in the variance and this is lost when I do linear regression because we have this pulled variance or covariance matrix so that's nice and maybe it's still not very surprising or not very useful so we wanted to move to something more challenging and that was the mass hardware implementation so one nice way to implement masking in hardware we took this example and that's what we got I will take this line again so this is Gaussian templates no problems in the mean, no problems in the variance clearly errors detected in the skewness and also in the kurtosis and this time it's interesting because it's a masked implementation so there should be information there so what did we do again moments correlating DPA what do we see oh good news no information at all in the mean first order secure and then we see that we have information in the variance skewness and kurtosis and I don't think we can say that this is negligible information so here we really face a situation where this tool is telling us well you did Gaussian templates but in fact this is not enough you should find something else if you want to extract all the information and again maybe slightly expected because Gaussian templates they only capture mean and variance as we know we have higher order moments if we mask but I think it's still nice to have this incentive now clearly it tells us that for highly protected implementation or just protected implementation we need more complex models to explain what we see and there was just a paper by Tobias Schneider about what is going to happen about exactly that cool so conclusion I think the main conclusion is simple right it's less formal clearly but probably more efficient and more intuitive tool it's more efficient because essentially it's what you need to do with profile CPA many times it's still costly so I don't claim I would do that for all the points of your implementation so I would still combine this with POI detection but if you have a couple of points of interest and you want to test a model there I think it's perfectly feasible with current means and the nice thing is it provides hints about the information loss these moments correlating DPA tells us do we lose a lot, do we lose little which we have not at all as an intuition when we were using full distributions we have a prototype open source code so if you want to try exactly these experiments univariate and so on that's on this web page and of course there are open problems I think the big one is how do we efficiently deal with in the same time highly multivariate attacks just as the previous talk and higher order distributions that's something I don't think we have good tools for this at the moment I think in general it's a hard problem the other thing seems questioning is this question we have model based estimation or moment based estimation we have distribution based estimation is it enough to just look at statistical moments and maybe just a PS nothing like all these assumptions of course it never happens if you do non parametric pdf estimation so if you go for kernels for example then you just have estimation errors maybe it's easier but probably in the cases that we face it's extremely expensive and I just wanted to conclude with this slide which shows that in the end we have a kind of nice separation between engineering challenges like measurements and preprocessing so be sure that what we do is good for this part of the attacks because it's highly heuristic so this we need continuous progress but for all the rest like for prediction for modeling, for key animation we reach the point where we have nice tools that are telling us am I good enough is what I'm doing sound in a certain way and that's it, thank you


Welcome to the Fiji Symposium 2019 here in Cairo, Egypt. We're very pleased to be joining the studio today by Barbara Iyai, who is the Chief Growth Officer, Managing Director of Africa for ELEMENT. Welcome to the studio. Thank you. Now, Barbara, perhaps you could tell us a little bit about ELEMENT and also what brings you here to this symposium. Sure. ELEMENT is an AI company that deploys mobile biometric software. So we deploy this software to help our partners all over the world identify customers in different sectors, banking, telecom, healthcare. We work with governments. I'm here because I want to talk about digital financial services and how our software is helping to revolutionize that right now. Now, an unintended consequence of a digital finance-led financial inclusion program is that it can lead to greater financial data inclusion, but not necessarily increase financial inclusion. I wanted to ask you if you agree with this statement. Absolutely. I think there's a difference between helping people actually obtain financial services and having a lot of data about people and not using a way that gives people financial services. I think one of the important things to lift people out of poverty is to create products and services that make sense for them. Digital identity, which is really what the core of ELEMENT is about, is really to help partners, banks, anybody providing financial services to understand who that customer is and be able to provide products and services that make sense for them. That is truly financial inclusion in terms of giving people the opportunity to not just get affordable financial services but get good quality financial services in an efficient way that makes sense for them. So what's the current landscape at the moment for digital identity? Digital identity takes a whole variety of spectrums. You can think about digital identity in terms of the digital track record of an individual. What ELEMENT focuses on is biometrics. We use machine learning techniques to create the digital abstraction of a person's biometrics, whether it's their face, their palm, their fingerprints, and biometrics is truly the more secure form of understanding who that customer is. So this digital abstraction is really revolutionary because it allows you to create a digital ID of that person using their biometrics and that digital ID unlocks opportunities, financial services opportunities in a digital way for the customer. And are there things that people should be worried about? The biggest thing with biometrics is privacy and security. And we are in the forefront of that as a population, as a global threat. This is not something that's just about biometrics. This is about people's data in general and digital platforms. So biometrics needs to be part of that conversation. How are we making sure people's data stays private and how are we making sure there is true security from end-to-end perspective, from how you deploy the servers and systems to what the customer sees. And part of what we do in ELEMENT is really to solve that problem for a lot of our partners. Let's talk about the Fintech sector. How do you see the Fintech sector reshaping digital financial services? I'm very bold about Fintech and I actually think some bold things are going to happen. As Fintech really came about because of cloud computing, because of open source technology, the barriers to entry to set up a Fintech company is very low. So what I think is going to happen is payments and cost of transactions are just going to get to zero. Because the Fintech company's goal is to keep that digital customer in their platform to continue to transact. So the more they can do that in a cheap way for the customer, the better. Data is also going to be a very important part of a Fintech company in terms of shaping digital financial services. That data is actually going to unlock a lot of opportunities and it's going to create a lot of interesting opportunities for the customer. But my vision and my personal opinion is that we need to figure out a way to marry traditional financial services with Fintech. Because until we really do that, the low income consumer wouldn't be able to really lift themselves out of poverty. They still need mortgages, they still need car loans. That's really what's going to take them out and we need to sort of bring those two worlds together. And finally, what role can governments play, do you think, to enhance the uses of digital financial services at national level? As I mentioned, digital identity is the foundation of a digital ecosystem. And I think governments can be bold in terms of creating digital databases, whether it's on a foundational level or on a functional level. A national ID system that's digital and has an API that companies and government services in the country can access in a digital way. Functional databases.  But it brings that industry together to serve the banking world, to serve the healthcare world. If governments do that, that really can revolutionize that digital ecosystem. Suddenly you can start seeing more digital players coming in and doing what banks should be doing, what healthcare companies should be doing. And just providing better opportunities for their citizens. Well Barbara, thank you very much for joining us in the studio today and we hopefully will catch up with you again some stage in the future. Thank you, happy to be here.


It's very dark because it's only half past five in the morning and I'm awake. I know but it's maths exam day So I've got up. I've got up early. I don't have to be there till 10, but I'm probably gonna get there about half seven because I Don't know just need to be there so early. I need to find where my room is because I'm in room SCT 012 Which I think might be in the new side of the building And we've only ever been in the new side of the building in one room, which is number nine. So I'm guessing It's next to that So anyway, I forget they're for half seven. I've got all that time to figure it out Just nervous even though I'm excited for it because it's one thing out the way It's one step closer to being qualified and I've got faith and confidence that I'm gonna pass it I'm so nervous still Like I'll see you all later Just arrived at uni. It's 20 past seven. I'm two hours early. This is crazy. So I'm at uni. Here it is And I'm gonna just go and do some work and take my mind off the exam and Hopefully it's gonna be right So I was panicking because I didn't know where this room was because it's in the new building And we've only ever had one room in this building before but I found it That's where we're gonna be doing our exam And I've remembered my ID this time remember on my last poster presentation, I forgot my ID I've got my ID this time. I'm really excited now 20 to 6 now actually because I've done my face over here. So just need to get dressed for uni I just wanted to update you about the maths exam yesterday because I didn't have a chance yesterday I was so busy after Um, well as you seen from the videos. So the maths exam In the morning as you saw I was so nervous Even though I was confident and I thought do you know what I can do this because I've been doing the practice tests online And I've been I had 10 out of 10 on the practice test the night before So I felt confident I felt ready But it doesn't take away those nerves and you're always gonna be nervous when you go into an exam If you're watching this and you haven't done an exam at university, you're just going into university It's never I came I'm not gonna lie even though, you know And you feel prepared You're so nervous and there's such an atmosphere in the room and you're going and everyone's feeling nervous And everyone's sat there everyone's quiet everyone's talking absolute nonsense because they're so nervous And it was just anyway So afterwards I felt amazing I during the exam I sat down. I was so nervous that The first I read the first question I was panicking And I was like, oh my god. What's this question? I haven't done a question like this Why is it like this? Um, and it's only because I was so nervous and panicking That I was just reading it wrong and I just had to take myself away from the screen I just looked away took a deep breath said, you know what calm down because you're gonna make stupid mistakes Like you did last year on the maths exam just calm down And I just took some deep breaths and then I looked at it again and I was like, okay I know how to do this question now And then it was fine seven minutes is all it took me to do that drugs calculation exam There was 10 questions you get 30 minutes. I did it in seven. So then I come to the end and I was like, oh, I'm at the end What do I do now? Check my answers So I checked all of my answers about four times I was just going through and through checking it again checking it again and I think As long as I haven't been nervous and I haven't read anything wrong. I think I might have got them all right but I'm worried that I've made stupid mistakes because I haven't read a question right because I've been nervous Or I've put in millilitres and seven milligrams or do you know what? I mean something so small that I haven't picked up on because I've been nervous But I think looking at it. I've got 10 out of 10 But we've got to wait four weeks for the results now and it's going to be it's always the worst is waiting for your exam results So fingers crossed everybody for me. I've got a pass at least I need to get eight out of 10 to pass. I haven't told you that I need to get eight out 10 to pass And the next year for the next one we have to get nine out of 10 to pass So but just to reassure everybody out there these exams They aren't that bad And you'll get practice ones to do online before you do your exam and those practice ones are exactly like the exam So you don't have anything to worry about. You're well prepared at university. They will give it to you on a plate Okay, not give it to you on a plate But the the practice tests are exactly the same as the exam tests So there's no hidden surprises. You know what you're getting yourself into As long as you know the equation to work out drugs calculations, you're going to be fine And I might actually do a video. I'll do a video not this week. Maybe next week or Actually, no, I'll do one next week for you. Um I'll do one on just drug calculations maybe and just the way that I do it And It is going to be just simple layman's terms because that's how I understand things So maybe I'm hoping it's going to help someone And maybe I can just talk you through some of the questions that you might get in a drugs calculation And the equation that you need to work out and then hopefully you'll put your mind at ease I hope and this puts your mind at ease. It's going to be amazing Like I've got no worries about drugs calculations anymore and I am honest to god. I'm the worst at maths. I'm terrible I'm really really bad at maths. I got um, I got an e for maths in my gcse's. I am awful Trust me if I can do this you can do this. So please don't be scared And as long as you just know what you're doing know the equations you're fine. Honestly, don't panic I'm just walking into uni now and it's our last day the last taught sessions of second year I'm so I don't know whether I'm excited or nervous. I can't believe it's our last taught sessions of second year How's that even gone so fast? Um, but I'll let you know how it goes later So I'm home and before I show you the next clip. I just want to update you So this morning we got to university and we were told that we were going to get our poster presentation results today Instead of tomorrow. So then we were all really nervous about this We're all really anxious and just sat waiting checking the emails Over and over until we had the official email to say the results are up and then we were sat in tgi's having a lunch because it's our last day of uni and That's it. We had the email and this is what happened Results are in Okay, just going to log on now How do we log them again? You got this here What do you got? Why is it still loading? I thought I saw 40% and then I was like what? 60 no, that's not even okay This table At least we passed I think that's a really good grade and they think yeah, that's great 60. I mean, that's a good grade, right? But you know what to me my personal goals is not meeting my personal goals So to me, I'm not happy with that grade. I in my head. I thought we were going to get at least 70% for that So when I saw the 60% grade I was just like what? and Anyway, it's not what I wanted, but do you know what it's still a pass you only need 40% to pass so I'm really grateful that I'm still on this course It's one step closer to my end goal which is qualifying because we all want to be qualified and Not only that but this is only half of a whole mark Because the poster presentation and the assignment are joined together for one whole mark at the end So this is only 50% so even though we've got 60% The assignment's going to make up a big portion of that as well. So I worked out I need to get 90% for the assignment if I want a first for this module Am I going to get 90% for this assignment? I don't think I am. That's a really high grade. I'm a last assignment I got 75% and that was a good grade and I was happy with that grade But I just I don't think I'm going to get 90% there's not a chance Yeah, so Excuse this. I'm sorry Whether I post this or not, I don't know but I think I'm going to post it because you know sometimes it's not all Completely positive and sometimes you don't meet those goals And sometimes we have to sort of take a step back and think do you know what? It's okay It's okay that I've got 60% it's okay If I don't get a first I should be so happy that I've got 60% That's An amazing result and I should be happy with that So I need to just stop beating myself up so much about it Um and just be really grateful because Do you know what for other people like my friends they got 60% and I was like, you know what that's a great result And I was telling them I'm really happy for you. It's a great result. So why aren't I taking that? Why aren't I thinking do you know what 60% is good? It's a good grade the pass marks 40% I've got 20 more percent more than I've just to pass And I should be happy with that and I need to stop beating myself up about it. I need to just get over it And fingers crossed. I'll do well in the assignment. I don't I'm just gonna write this one off I think I'm not going to get a first for this module and then I've got the exam So if I do well in the next exam, I do well in the next module I should qualify second year with a first if I get my goal But you know what realistically do your grades count when you qualify? Not really Nobody's going to look at your grades when you're going for a job offer and say, oh, this one's got a first She's better than her because it doesn't make any difference having a first doesn't make you a better nurse So I need to remember that and I need to tell myself that But I am even for a first still But you know what Saying that I feel better now. I've had my little cry I've reflected through the vlog and I feel better.  I'm just I'm speaking about it. So I feel better now. I've said that I don't want anyone sympathy. I don't want any I don't want anyone sympathy. Please don't comment. I don't want any honestly. I promise I'm just I'm venting it out and letting you know and Yeah That's all I've got to say about that So that is it last day of lectures for second year is over Tomorrow apparently we get our placement allocations, which I'm going to do a live video for that too I say live when it posts. It's not going to be live But I'm going to take the video just like I did with my exam results To find out what my placements at and fingers crossed for tomorrow guys Please pray for me. I want a really good placement. So I've just had the Facebook notification that are that someone's oh my god I can't even speak someone's gone into Facebook and they've put on there that our placement allocations have just been released It's quarter past eight at night and I'm trying to log in and it's been really slow And what usually happens is the allocations gets released and then the whole system crashes because everyone's going on to the allocations And this is exactly what's happening So then gone It will just sit on this page loading So it might be a while so I'll be back Still waiting come on Look how slow It's crashed because everyone's got excited and is just trying to jump on the bloody I'll get on it at some point So finally got on the page. I'm on an adult surgical ward and I don't know what type of surgery because it doesn't say so I'm gonna have to look into it and find out So I've just woke up and it's half seven a.m. And it's my day off And last night as you saw I was waiting for my results. I finally got onto my results and I'm at trauma and orthopedics, so I'm quite excited about that because I have been on an orthopedic ward before and I've been into theaters before And I really enjoyed it. It is something I enjoyed. There's gonna be a lot of wound dressings. There's gonna be drains There's gonna be a lot of observations And it's gonna be really good. I'm really excited. I'm not excited for the 4 a.m. Start. That's right I have to get up at 4 a.m. Because of where I live and the traffic and things on the motorway I need to I need to leave early for this placement So I get up at 4. I'm out the house Usually at placement by half 6 6 a.m. Ready to start at 7 So I'm not looking forward to that because it is going to be a tough and I remember last year it was tough I'm going to be so emotionally drained mentally drained. I'm going to be physically drained and It's not going to be pretty Oh, you guys haven't seen me do a ward yet because I only started vlogging in december So you've only seen me on my gpu placement, which was amazing and I really loved that placement Um, so I get to talk to you all about ward life now. That's going to be really exciting for everyone I think I'm actually excited to do that for everybody. So and I just wanted to add I'm so sorry for having a little cry yesterday because I just I watched it back. I thought I need to watch this back and just decide whether I'm going to upload it or not And I look so ungrateful and I'm so sorry to anybody watching this and thinking how ungrateful you've got 60 percent when people are failing They've got 40 percent 50 percent And you should be happy with 60 percent and you're right. I'm fully say you're right I feel ashamed for getting upset because I've got 60 percent And I am chuffed. I'm happy that I've got 60 percent and it is a cheat a still an achievement to me So I just wanted to say that I'm really sorry that I got emotional over it and I am so grateful And you're right people do fail never to become a nurse and I'm so grateful to still be here I'm going to put it up because it's always nice to show a thing that not everything is positive Um, and not everything is happy go lucky You do get those stressful moments and you are going to have a little mini meltdown at some point through nursing Um, but you know what that's very rare and the positives and the benefits clearly outweigh the downs and Because it's very rare that I've had any problems on this course. So Just be mindful of that and when you see negative comments from people and saying how stressed they are and ask them about the good things Ask them. Okay. So what's going right and why are you still here if it's that bad? Because you know what it's not that bad They will be having a bad day. They'll vent about it because that's what we do We are the uk. We are english no offense to anybody. This is just my opinion But we moan we're a nation of moaners Which is why I wanted to create a nurse positivity around nursing because I love nursing and I'm happy in nursing But I just wanted to show the that we do all have mental breakdowns We do all have a cry. I'm the most positive person and I will have a cry every now and then But do you know what it's worth it and I would do this a hundred times over if I could Yeah, so anyway, that's it from me. All of you have a great weekend. It's going to be a beautiful one. I think And I'm not stressed anymore and Don't forget if you haven't watched our Collaboration episodes go back and have a look at it. I'll put the link below And tomorrow for you guys is going to be sunday. So tomorrow at 6 p.m We've got our last final episode of this collaboration and we're going to be talking about What all about nurses and paramedics and how we should collaborate together and how to work effectively and things like that So it's going to be a really good one. I think so tune in for that and I'll see you next week


Good morning. Happy Friday. Today's Friday flop is actually from one of my cases Monday. I had a few of these come in similar to this on pulp therapy. This tube was necrotic at the time when I did a pulpectomy on it. And we tend to try to save second molars and canines. If we lose a canine, we have to extract the contralol or canine to keep symmetry. And then the second molar can help prevent the 16-molar from coming in and taking space away from the premolar. So in this case, this was a one where we didn't have the 16-molar erupted. I was trying to save it. And it ended up not working out and developing an acute aqueous abscess. And this one, looking back, really, really did the bite wing. It's pretty obvious the error here that I did not reduce enough occlusally and we had an open margin. And I think that is why this case failed. So I'll be looking at the back and trying to make sure that I get my crown seated all the way down. And the next time I do one of these, I hope you have a great Friday. And look forward to sharing the rest of them with you next week.