 So, we are we are ready to start now. So, good afternoon and welcome to this first experiment in IIT of conducting a regular class of a course in different classrooms where the teacher is present only at one place. I would like to very briefly interact with the students in the other hall. So, currently I can project the view of the students from hall 3 can somebody in the front seat with the red t-shirt can raise his hand please in hall 3 yeah you yes thank you all of you can see him fine. The problem is he cannot see you, but he is seeing me. So, he is seeing you via me also I suppose I am audible if all of you in hall 3 can listen to my voice clearly please raise your hands hall 3 the students who are sitting in the other hall can they listen can they hear my voice clearly if they can please raise your hands now they heard me ok fine. So, we start this class as I said this is an extra session devoted entirely to discussions and quizzes. The the schedule for the day is that we will first see how quizzes are conducted using Akash then we will have some very brief discussion on string processing and conduct a few quizzes on string processing then we will have some question answer session then we will break for 15 minutes during which time all students sitting in this hall will go to the other hall and students from that hall will come here you must of course move with your baggage and particularly your Akash tablets they will swap the databases. So, that the quizzes can be conducted for you when you are in that room as well would you like to instruct them how that quizzes are to be conducted are you ready or you are you will take some 5 minutes yeah. So, where is the pdf have you given it to him unless it is loaded here what and this all also people have seen, but then there are two classes suppose there are four the pdf file should have been cyclostyl heroes then given to all of them that is all. All three students have you all seen the pdf which describes how to conduct classes you get that pdf here and call this pdf has to be uploaded here. So, basically I am back again in communication with both the classrooms since we are going to experiment with conduct of quizzes on Akash tablets all of you would have ordinarily a preloaded clicker application. However, our clicker team has upgraded that software. So, each Akash tablet needs to install the new version of the software. Obviously, the process has to be simplified because we cannot waste 2 hours in installing those things. So, what let me introduce Rajesh Khushalkar Rajesh can you come in front of camera he Rajavail and the entire team has worked on the clicker device earlier and the clicker software which they have implemented here. Now, what they have done is they have prepared a new APK file which they have already loaded on the back end servers and you have to download that file. So, there is a piece of software which will automatically download that file and it will install it on your Akash devices as well, but you need to do something to facilitate such installation. Understand that in the other classroom people have already my colleague Dr. Rajesh Khushalkar tells me that many of the students have not charged their Akash tablets and therefore they are not working. You probably banked on the fact that you will have a power supply on your table here that is right. Welcome to the discovery of technology not working. So, the complicated technology such as back end servers, the tablets everything is working but the simple technology of power supply is not working. That is unfortunate it only tells you that in the next semester when the issue starts using Akash devices for conduct of graded quizzes then you better come from home with your Akash tablets charged. Today those of you who have not charged their tablets unfortunately will not be able to participate in this quiz, but you will see the interaction and see what is happening. If how many of you do not have their Akash tablets charged can you raise your hands ok 5 or 6 that is ok. You look at your neighbour's tablet then to figure out what is that fine. Some silence from the other classroom as well I can see all of you and I can hear all of you. So, now here is the procedure to download the new APK file. First of all you have to open your browser on the Akash tablet. One second there is a I am being prompted that they have missed step 0. The step 0 is that your Wi-Fi should be switched on. The Wi-Fi should be switched on and it should be connected to an access point called Akash workshop. How many of you have been able to find out Akash workshop and your tablet is connected to Akash workshop? Fine. All of you should do that. So, this is the IP address in case you cannot find that Akash workshop title. So, all of you are connected to Akash workshop. Now, you open the browser and they should do this. Please type the IP address in the address box which is 192.1 ok. I apologize to all of you. There is some confusion what my team has done is they have been using this to show these steps to about 18000 students who attended this workshop and gave quizzes on Akash tablet from 250 colleges simultaneously. So, unfortunately the PDF file is still same, but some of the addresses are different now for this particular thing. Has this address been written in the other room as well? In bold. So, can you tell me the steps now? First step is open the browser. So, you just open the browser. All of you open the browser. Now, the next step is to insert an IP address in the address box, but do not insert the IP address which you see on the projected slide. You insert the IP address which is written on the blackboard which is 172.16.1.10 172.16.1.10. All of you have inserted this IP address. Now, you have to download when you click there itself it will download the clicker APK. Are you seeing this icon? Remote APK. Click on that icon it will download and click on the IITB clicker APK which one they have to. So, both APKs you have to download. So, all of you have got these two applications. Can you see the clicker APC clicker APK? Have you entered the correct IP address? When you when you press return on that IP address what do you see? It says web page not available. Is Wi-Fi connected? How many of you have got Wi-Fi connected and have downloaded these APKs? In the other class hall 3, can you zoom out please? Now, I am I am asking this question to the students from other class. How many of you have been able to connect to Wi-Fi? Put in the right address and have been able to download the APKs. Please raise your hands. Can you check if the Wi-Fi is connected? Deepthi is your Wi-Fi getting connected. Deepthi, can you raise your hand if you can hear me? So, is Wi-Fi getting connected or not getting connected? Please report back the problem. Sir, Wi-Fi is getting connected, but like few systems like few tablets are able to one left. Can you define few as in 1, 2, 10, 20, 50? Sir, it is around like 30 to 30. Those who have connected to Wi-Fi. Okay. Now, have those 30 people downloaded the APKs? No sir, they are getting some login access error. Sir, only few of them have downloaded. So, in my class of about 170 students, you want only 2 students to give the quiz, is it? What I can do is, I will take the average marks obtained by these 2 students and allow them to all the students. Okay, here, how many of you have been able to download the APKs? Can you raise your hands? Wow, not bad. My class is doing better, Deepthi. There are about 40 people who have downloaded all the apps. We are also trying here to like get it done. Have you discovered a mechanism to speed up the Wi-Fi access? Okay, fine. So, those of you who are downloading should see this screen after the download is complete. You will see on the right hand side, a series of IITB clicker to APK, etcetera, etcetera, etcetera. What are they supposed to do next? Now, when you have got this, you have to install only one application. So, click on the remote APK for installation and when it asks for install, install the application. Those of you already downloaded the APKs on each APK, click on that APK and then say install. Have you finished installation? Okay, how many of you have been able to install both the apps? Can you raise your hands? Yes. Fairly large numbers. So, both the APKs are installed now in the other classroom. By the way, keep the classroom zoomed out. Please do not pan, please do not zoom in. I would like to see the entire class. All three, all three cameraman, I want to see the entire class please, not just one row. Please zoom out. Okay, okay. Okay, out of students in hall three, how many of you have been able to install APKs? Please raise your hands. If your installation is complete, not just download. Can Deepthi tell me the approximate number of students who have been able to install the apps? Over to you, Deepthi. How many have installed the APKs? I can see one percent. It's around 9, 10 sir. Okay, that's fine. Clicker team, can you conduct a sample general knowledge quiz here please? Hello. At this stage, we will stop all attempts to any more download and install temporarily. Please stop any more attempts of downloading and installation. I want the clicker team to conduct one sample clicker quiz. What do they have to do to conduct the quiz? They have to run? They have to open that APK, this one. They have to, after this, they have to click this one. So, they have to open R clicker. Okay. It will be available in that screen, main menu. Okay, now go back to the main menu and start the application R clicker. The R clicker application is the one which will permit you to get quizzes and answer them. So, please start the R clicker. Okay. How many of you have started R clicker application? All of you. In the other classroom, they have also started. You have to, it will ask for Enrollment ID. Enrollment ID, which is actually your roll number. So, there are two data points that you have to insert. One is your roll number because in the backend database, we have the roll numbers that, as the database entity for you. So, you have to enter your roll number and you have to then enter an IP address, which is the one which is written on the board, which is same for both. Yeah. So, there is an IP number written on the board. In hall number 4, it is 172.16.1.10 and in hall number 3, there is a different number which is written on the board. So, please, hall number 3 students enter that number after entering your roll number. All of you have done that and then you have to press connect. You will then connect to the main quiz server. When you say connect, it should show waiting for quiz. Connection timed out. Try it again. How many of those who had correctly downloaded the application started the application and have been able to now connect to the backend system where you are getting waiting for quiz? So many people are waiting for quiz. Not a bad thing at all. In hall number 3, how many of you are waiting for quiz? Can you raise your hands please? 1. I said hall number 3. I said not hall number 4. 2, 3, 4. Fine. We will very quickly do an experimental quiz. Where is my quiz master? So, I am launching this quiz. Those of you are waiting for quiz should get this quiz downloaded. Somebody has to do something in the other classroom. So, have you got this quiz on your tablets? It will come in due course, but you can see the quiz on the screen. So, I would like to know who are these two friends who have pressed 1 and A and B in the other classroom. But there are 10 people who gave right answer. So, you can see these two rule numbers. By the way, this is just to tell you that automatically, hello may I have your attention please. It is important because this is a methodology that you will be using for all the remaining years in this institute. So, you better understand and make suggestion. Hello, can I request for a pin drop silence please? Since we have spent enough time in trying to install APKs on Akash devices and trying to connect to a quiz and the first attempt did not yield the desired results. So, what we will do is I will spend just 10 minutes in discussing a few aspects of string processing on which we will attempt another quiz later. As I said, there are quizzes on character string handling and some question answers. Since we have spent enough time in just trying to connect our Akash tablets to the quiz server, we will cut short the actual discussion which is important which is related to string processing. I will just assume that whatever we discussed in the classroom last time, you have all understood. And those who were absent or did not understand it properly had the time in the morning today to look at the slides which I have uploaded already. In which case you should be familiar with the basic string processing problem. What I am going to do is to discuss just one or two. So, no audio from your side. Yes, I have decided to cut short the discussion on string processing by assuming that all of you have understood what I discussed during the regular class. And others including those who were absent have seen the slides today morning which I had uploaded last night on the model. What I will do now is just describe a few issues which are related to string processing which you should generally be aware of. This will be in the nature of revision. Instead of using the whiteboard on my slides, I will be using the whiteboard of the AVU system. Incidentally, AVU system which we are using for conducting this class permits me to look at the other classrooms. You can see this is the other classroom. If there were three or four more, I could have seen them like this. You as well as all of them can see this video of the teacher and they can see this whiteboard. So, whatever is shown here, they can see it here. These are the screens. This is the document. So, for example, this was my first slide. This is my next slide and so on. What I am going to do now is temporarily remove the slides and use the whiteboard which is the whiteboard of this AVU system. AVU system incidentally is a software which has been developed by Amrita University. It has been a large effort for several years and we should all be proud that a world class industry great product has come out of another sister academic institution after years of work. We and their partners in the national mission projects, we use exactly the same mechanism not to connect to two classrooms or three classrooms, but up to 200 classrooms across the country and people attend classes from those places. So, this is just an experiment to see whether we can meaningfully deploy the same methodology to conduct our regular courses. This side or this side. All of you are familiar with this declaration. This declares two strings S1 and S2 of an arbitrary length 100, which means you can have up to 99 valid characters and a backslash 0 at the end or smaller string. We already know that the characters are internally ASCII code numbers and the values are such that for example, the value for A is smaller than value for B is smaller than value for C and so on. This order is called lexicographic order. So, this is the order which is used in listing words for example, in any sorted order such as dictionary. So, you will find all words beginning with A come first followed by words beginning with B. All the words beginning with B will be ordered as per the second later and then third later and so on. So, it is possible for example, to say that if I have two words book and a word boat, which word will come first in the dictionary and which will come later. Now, the power has gone in the other classroom. Words will come first which will come next in a dictionary. So, can we say book is greater than boat? Book is greater than boat because B and B is same, O and O is same, but the third character O is larger than the third character A. This is what is lexicographic order. What about if I had the word boating? So, boating is larger than book, it has more number of characters. So, number of characters in the string do not matter. The number does not matter. What matters is each word compared to the corresponding, each character compared to the corresponding character. If one is greater than the other that string is greater than the other string independent of how many characters it has that is how dictionary is ordered right. So, this sort of facility needs to be preserved in any processing of string that we do. It looks like the use of modern technology instead of speeding up things is making things very very slow. Ordinarily we would have discussed at least two or three big programs in the class right. Well, believe me that happens when the technology works. It works exactly as it works in a single classroom. You just wait for three or four minutes and I will announce the swap and hopefully after the swap thing will work well. But in the meanwhile we can distribute the background material for the quizzes. Has somebody given us the Xerox sheets that I have got?