This video is going to talk about formulas and how to solve a formula for a variable and then how to work with them in word problems. So the first thing that you want to do is always clear your fractions and then you want to clear the parentheses and then you can apply those addition and multiplication properties. So you look at it and I want to solve for R. I have no fractions but I do have parentheses so I need to multiply everything by that P. I need to distribute the P. So on this side I have A and then P times one is P and then P times RT is just PRT. Well I want to solve for this R so I've got to make sure that I get this R on one side by itself and then if I have to take things away I can't. So I only have one R is on one side so I'm ready to start doing the addition property and the addition property tells me that I want to take this P and take it to the other side. I've got to peel that layer of my onion so we subtract P from both sides. Now remember A and P are different. It's like apples and pears. So I have to say A minus P is equal to PRT. Well now I'm looking at this problem and I want to get to that R again but I've got this P and this T that are being multiplied by it and how do you get rid of something that's being multiplied by your variable? You divide it. So I need to divide this side by PT and I have to divide the whole other side by PT and when you're working with fractions you can just divide the whole side. So the P's and the T's become factors of one and we're just left with R equal to A minus P on the top divided by P over T and I'm good with that answer. You don't have to take it any further than that. Let's try this formula. I'm trying to solve for C. I got a fraction so let's clear the fraction. You wouldn't necessarily have to clear the fraction because I just have a constant in that thing but we were going to follow the rule so we're going to clear the fraction. So if I clear the fraction I need to multiply everything by that denominator of five so I have to multiply. Let's look at it this way. I'm going to distribute the five to everything. I typically don't write it this way because I'll forget and it gets messy. I like to cancel things out but we can rewrite this as 5 times F and then equal to 5 times 9 over 5 times C plus 5 times 32. If I write the 5 times everything then I won't forget. Okay this is still 5F equal to this 5 is a denominator and remember this is like over 1 so it's a numerator and so I have 9C left plus 5 times 32 and 5 times 32 is 160. Now again what are we solving for? We're solving for C so I need to get rid of this 160. It's being added so to peel that layer off I'm going to subtract 160 and I can't combine it literally with my 5F so I just have to rewrite 5F and then subtract that 160 and then is equal to my 9C and I'm trying to go for C so I'm going to divide by 9 because it's being multiplied by 9 and my final answer is 5F minus 160 over 9 is equal to my C. So this example is the same kind of problem except that we have a y equal 1 half x minus 8. It doesn't really look like a formula but this is the kind of equation that we're going to be solving in the next chapter or two. So let's see what we could do for it. We want to solve it for x excess. So here's what we're trying to solve for and to do that then I need to peel this 8 off so I'm going to add 8 to both sides and remember I can't combine my y and my 8 so I have y plus 8 on the left hand side and that's equal to 1 half x. Now we had a fraction here and last time we cleared the fraction but this time since I just had one term with a fraction in it and I figured I would have to clear it. I could just work with it and see what happens. So I had this 1 half x it's being multiplied by x so that means I need to multiply both sides by 2 over 1 and that means both whole sides have to be multiplied by 2. So I have 2y plus 16 when I distribute my 2 and that's going to be equal to the 2 over 2 becomes a 1 and I just have x. So let's look at how we can translate and then use a formula. The area of a triangle with a base of 18 inches and a height of 7 inches we're trying to find that area but we need to know what the formula is and the formula for area of the triangle is 1 half the base times the height. So let's see what we have. We want to find the area so that's a and the base b is 18 inches so I have 1 half times 18 inches times the height h which is 7 inches so 7 inches and I need to figure out what that is. Well we are talking about multiplication here and so that means inch times inch when I'm thinking about my units and remember when you multiply the same thing over and over again we can use an exponent and the exponent tells me that I have two factors of inches so inches squared is going to be our units. So now that we know what the units are going to be we can really just rewrite this as 1 half times 18 times 7 so a is going to be equal to two things at a time 1 half times 18 would be 9 times 7 and 9 times 7 is going to be 63 and from over here we know that that's inches squared is the area. So when you're multiplying your units will have an exponent on it. This one's a little trickier but let's read it. Find the length of a rectangle that's what we're looking for and we're going to call that l of a rectangle if the perimeter that should say the perimeter here we're going to call that p is 64 inches and the width we're going to call that w is 20 inches. Now why did I put all that in there because the formula is perimeter distance around is equal to two times a length plus two times the width. Now let's think about this for a minute we're going to have our length and inches plus our width and inches and if I add inches and inches they're the same unit. I'm not multiplying this time so I don't have factors I'm just this is almost like saying apples plus apples I'm just totaling my inches so if my unit is going to be inches when you add and subtract you keep the unit if you multiply you're going to have an exponent on your unit. So we have p is 64 is equal to two times the length well length is what we're going to be solving for plus two times the width which happens to be 20. So there's our equation and we have one variable so that's nice and if we keep going then 64 expanding this out would be 2l plus 40 and now we know that we need to subtract the 40 to peel off the constant layer and we have 24 is equal to 2l and then if we divide that by two we're going to find out that the length is equal to 24 which means that in a sentence the length is 24 inches.


So, actually we will go ahead with the class network now further and we will now formally proves that in what cases it will be rearrangement non-blocking and how you will actually do the rearrangement that also the answer will come, we will also prove now formally when a switch will be strictly non-blocking in a three stage class network. Intuitively we do have an idea that number of middle stage switches has to be equal to twice the number of inputs per switch minus 1 ok, if it is equal to that or greater than then it will be strictly non-blocking. But before doing that we have to understand the formulism of Paul's matrix that is where I think I left in the previous class ok. So, the Paul's matrix is nothing but it is a matrix it is going to have rows and columns obviously and the number of rows is equal to number of input stage switches not the ports remember it is equal to number of switches in the first stage ok. So, if I am going to have say for example, a switch like this which has four things there might be many number of incoming ports per switch. So, I will only write a, b, c, d and there will be only four rows in this case. So, I will have only row a, row b, row c and row d. Similarly on the output side on the third stage basically I will have number of switches and they need not be same I am not the whatever I am now going to do the formulism is for any kind of class configuration this need not be symmetric number of input ports need not be equal to outgoing ports ok. It has it can be anything arbitrary so I may even end up in having five switches nobody stops me I may end up in having five switches the number of ports here can be different then number of ports per switch there that is also permitted. So, far it is a class network I will be able to deal with it earlier case was I took everything symmetric and then through some rational or logic I was able to derive when the switch will be strictly non blocking. So, it is a general case now. So, if you have for example, now a prime, b prime, c prime, d prime and e prime. So, in this case correspondingly I will have five columns and I call it a prime, b prime, c prime, d prime and e prime. In the middle stage again there will be many switches. So, fundamental rule is if the outgoing ports one thing which is very obvious is these outgoing ports in the first stage has to be more than the incoming ports. So, at the switch itself will not create any blocking is very important so should not create any blocking. So, because if somebody is trying to come in output port is free, but these ports are less you cannot do it. So, blocking happens because of the this n, n 1 is a smaller than m 1 so that condition should not happen. So, n 1 should always be greater than m 1 if that is there and m 2, m 3 is again greater than n 3 then also the blocking will not happen because of the switch it will only happen because of interconnection. Now, what I can do is only thing which I need to manipulate now here is number of switches in the middle stage. If I only keep it one unfortunately there will be only one line coming from that it will be a blocking switch because these ports are less than the input. So, one thing which is sure is if I have this as a input and this as an output and for example, if this number of outputs n 3 I am just going from certain fundamentals now. So, m 1 and n 3 if they are equal it is ok then we know that if the number of outgoing ports is less than m 1 number of incoming ports is less than n 3 it is blocking which actually means when r 2 is going to be less than m 1 or n 3 whichever is the minimum of the two it is going to be blocking in fact, that is what the result which you will get. Now, if I want to set up a connection from here I want to set up a connection from here ok. So, one thing which is sure that r 2 should be greater than or equal to maximum of m 1 sorry not minimum, but maximum this is this has to be ensured so that the blocking does not happen because of the switches it happens because of the interconnection so that is the first condition. So, if you are below this your switch is a blocking switch it cannot be reasonably blocked non blocking it also cannot be in fact, it has to be yeah if r 2 is less than maximum of m 1 n n 3 then switch is blocking 100 percent blocking ok. So, for certain combinations you will find switch cannot get through and blocking is not because of interconnection, but because of switches itself ok because the number of ports will become smaller than the outgoing ports on this side or the incoming ports on this side the first condition. So, this is one of this thing is clear it means now when I am making interconnection going to be in this way there is r 2. So, when you make r 2 is going to be greater than equal to this condition in the beginning r 2 will satisfy something as I keep on increasing r 2 there must be an r 2 after which I should be able to set up all connections all possible connections because r 2 is infinity switch has to be strictly non blocking number of IO ports are limited ok number of IO ports are limited. So, at certain value of r 2 it will become strictly non blocking at certain value of r 2 it should be rearrangeably non blocking and below this it should be blocking, but still I am not sure whether it is going to be rearrangeably non blocking if this condition is satisfied this I am not sure as of now. So, this I do not know about that thing, but at certain value of r 2 it will become rearrangeably non blocking and after certain threshold it has to be strictly non blocking strictly non blocking you are not rearranging any connections you should be able to in every state should be able to set up the connection. In rearrangeably non blocking you have to make the rearrangement of existing connections IO map or IO pairs still are maintained as same and then you can set up the connection intuitively we actually can reduce that rearrangeably non blocking switches will require lesser amount of resources compared to strictly non blocking which is going to be true actually ok. So, that is the case now let us look at how the pulse matrix actually helps us. So, we will now put some number or whatever it is on some symbols actually on this middle list is switches and when a connection is set up. So, when I take for example, this particular port I set up a connection I set up to this particular port between these two ports A prime and D prime I use a switch 9. So, I am going to route the call through 9 I can now put in the cell that I am now set up a call I am not worried about which particular port here because there can be exactly one call which can be set up from there can be multiple, but through 9 only one can be set up. So, if there is another port which is free which also wants to go to D prime I will have to use some other switch it cannot be through 9 because there is only one line here there is only one line here. Now, it is not one by one there are other switches also so, everybody is connecting. So, the number of switches here is R 1 R 3 so, this is R 1 by R 3 switches all middle list switches are R 1 by R 3 they have to be because you cannot leave any port open here every port is connected in the middle list stage all inputs are coming at this port all outgoing ports are on this stage all middle stages have to be connected to somewhere that is as per the clause interconnection thing. So, the next one for example, this same guy wants to set up a call from here through 5 that is the next one this guy A wants to set up a call to say B it can use something like 3 so, I will can put 3 here some other switch wants to set up a call to D prime this can be through this cannot be through this route because this is occupied. So, D can be connected to D prime through 8 that is what the pulse matrix is now what are the validity conditions now one of the very simple thing if I would have like to set up this particular connection this line was free, but could have used this I could not have used this line because this link is already occupied because a connection from A to D prime has been set up. So, which actually means 9 cannot come in the column corresponding to D prime because it is already been occupied because if D to D prime I would have connected through 9 I would have put a 9 here, but 9 cannot repeat in the same column, but if I am in a multicast configuration multicasting is a one input is being connected to multiple outputs I am trying to make copies of the signal to multiple outputs I am not estimating any probability just find out which ever is free and make the connection D to exactly right from here to 9 and from here to you can certainly use whose stops now there is no multicasting because this is setting up one connection this way and one connection this way this is permitted by this cross bar this permitted. So, I can actually put D to B if I want to put it I can put 9 here. So, conditions actually are coming on columns and rows what elements can come whether elements can be duplicated in a row whether they can be duplicated in column or not. So, those are the validity conditions ok. So, I am now coming to a case where this port whatever M was giving to B also wants to send it to somebody else for example, B you forget this part of a connection. So, same input is coming here this is a cross bar I am able to put a copy on this side also that is a multicast case. In that case a to D prime has 9 a to D prime also can have a 9 which actually means I can have duplication of elements in the rows that is possible because is the multicasting. But duplication within column was not permitted I cannot combine this and this signal and send it over single link to D prime that is not possible it will create interference. So, I am trying to emphasize get whether elements can be repeated again in rows or columns or not they can be repeated in rows within rows they can be, but within columns they cannot be and this repetition will only happen if it is a multicast scenario not in unicast case unicast it will be only coming exactly once. Why it is going to come exactly once if you look at a 9 5 has already come there is no multicasting if 9 has already come I cannot use this link to set up any other connection. So, this 9 cannot repeat anywhere in the column in the row similarly in the column I cannot repeat 9 if this link is already being used to set up some path from D prime to some input port if this 9 is already used I cannot also repeat if it is a unicast case. So, now let us write down what will be the legitimate pulse matrix conditions I am formally writing them now I have explained it by example each row will have how many elements tell me that at most number of elements are r 2 r 2 can be larger than I is usually going to be larger or equal to a greater or equal to the number of incoming ports m 1, but how many entries you can make here can you put r 2 entries you cannot set up r 2 connections only m 1 connections at most you can set up. So, m 1 entries from those r 2 possible symbols any m 1 you can use and they can be put in the row. So, that gives a maximum size of elements in the row except if it is a multicast then it will be duplicated, but that actually means there can be exactly only m 1 symbols which will be there the symbols can be repeated in a row if it is a multicast out of r 2 only m 1 symbols will be used and they can be any combination there is no restriction on that it all depends on you are setting up the connection. So, first case is each row can have at most m 1 symbols this actually means m 1 symbols this actually means number of the paths number of paths which can be set up from a switch from a input stage switch can at most be m 1 that is what it means. So, I can write that number of paths can be equal to inputs to the switch input stage switch and which is the stage 1 I write it simply input stage switch actually means only this switch not the whole switch only this switch which is m 1. So, that is the first condition next I have already told you what about column give me the equivalent statement for a column n 3 right exactly it has to be only n 3. So, what I will do is the whole statement is going to be same. So, wherever there is going to be a let me write it down because each column can have at most n 3 symbols and this actually implies that number of paths at the most equal to number of outputs in output stage switch. So, you agree with these two conditions now third condition is the symbols in each row. So, I am not worried about which symbols there will be only m 3 symbol m 1 symbols or n 3 symbols, but they all symbols have to be distinct if it is a unicast case. So, this actually means one edge from each first stage switch to each middle stage switch and no multicasting is allowed in this case. So, this actually means at the most r 2 symbols can be there. So, whatever is the minimum of m 1 and r 2 that has to be here. So, if you do not bother about that condition at most r 2 can be there because only r 2 symbols are there and you are not having distinct thing because there is no multicasting.  They will not be repeated actually that what it means because there is no multicasting, there is no relation they can be independent they can be independent and you can generally you can make a general proof on that. Usually in most of the actual implementation they will all be equal m 1 and n 3 will always be equal r 1 will always equal to r 3 usually symmetricity will be always maintained in actual implementation because this is, but there may be cases where you do not want asymmetry asymmetric cases are possible. So, now let us come to the fourth condition symbols in each column should be distinct only one edge from each second stage switch to each third stage switch and an edge cannot carry signals from two sources and that also implies that at most r 2 symbols if you do not bother about the other statement when you combine you get min max all kind of combination independently at most r 2 symbols can be there distinctness only if the multicast is there condition number 1 and 3 will not be valid, but 2 and 4 will be strictly valid that is a final thing for multicasting 1 and 3 not valid, but 2 and 4 are valid that is only change you can have more than m 1 symbols in the row once it is multicasting and they may not be distinct you can repeat them. So, they will not they will be more than r 2 that actually what it means they can become more than r 2. So, as a consequence if I put everything in a figure I can simply write this thing as. So, in a row you will have minimum of m 1 r 2 symbols at most minimum of m 3 and r 2 symbols that is what it means actually. Now formally writing down the definition for a strictly non-blocking switch and really non-blocking switch I have to define the sets of the ports. So, let me give the definition and then state the statement. So, let t prime be subset of where t is nothing, but set of all transmitting terminals or input ports and there will be r prime this can be any subset where many possible values of t prime and r prime. So, r prime be subset of r where r is set of all receiving terminals and there is a state of the switch. Now state of the switch is nothing, but this that each element of t prime this basically t prime is all ports which are busy r prime set of all ports which are also busy. So, what will do is each element of t prime is connected to. So, connection how we write we write a legitimate multicast tree is there from each element of t prime to elements in r prime that is the way it is being written actually. So, that is only a formal language, but whatever I am saying otherwise is actually means the same thing r prime by a. Now this is legitimate all pulse material conditions are satisfied. So, if it is multicast even those conditions are satisfied. So, multicast, unicast everything is taken care of by this and usually number of members in r prime most of people will think the cardinality of r prime and t prime is going to be same the number of members in that set because one port is connected to one outgoing port, but in multicast this may not be true. So, cardinality may not be equal actually. So, that is why multicast tree actually which has been mentioned that is one important tree that each element in t prime is connected to r prime through a legitimate multicast tree. So, but r prime can be more. So, there should not be any element in r prime we should be left out. So, for that there is another thing that each element in r prime connected to n element in t prime. So, an element in t prime can be connected to multiple elements in r prime, but an element in r prime is always going to connected to only one element in t prime. So, you can only split in the forward direction while doing the you cannot combine actually combination is not permitted, but splitting of signal is permitted that is what it means and that is what the multicasting essentially actually also implies. Now, with this set definitions now let us define what is a strict sense non-blocking network then we will go to the proof of that. So, a strict sense non-blocking and element t which belongs to t minus t prime every incoming port that is what it means. So, symbols and everything looks very dangerous, but it is only means a free incoming ports any free incoming port is what it is implied by this t. t prime is a set of all busy ports t is set of all ports you remove these all busy ports this set of all free ports t is a member of that. t can establish now that is very important it cannot not only establish one to one connection the way I defined is earlier I have told you there was one input port there is one outgoing port both are free I should be able to set up the connection no that is not the only condition if this is a free input port there are many outgoing free ports for in this free ports for any set any subset of the free ports I should be able to set up a multicast tree that is the condition for strictly non-blocking not point to point connection. So, I am now deviating from whatever I have said earlier. So, this is more this will be a much more proper definition of strictly non-blocking network. So, I should be able to set establish a legitimate multicast tree any subset of r minus r prime that is more appropriate definition, but this is still not defined what is a strict sense strict sense now I am defining without changing previously established for and this should be true for all possible t prime, because t prime also can be all various different possibilities which exist for all we have to now qualify it t prime r prime all connection patterns between t prime and r prime this is the I think a complete definition this is a very much complete definition and instead of without changing if you say by rearranging all the existing connections from t prime to r prime. So, that all legitimate existing multicast trees are still maintained, but the connection patterns may be rearranged or may be redone again and then if you are able to do this establish a new legitimate multicast tree all the time then that is a rearrangeable non-blocking switch. And there is something called wide sense non-blocking I do not have a formal definition, but you can try writing it out I will give an example of wide sense non-blocking switch I think later sometime and that is the only example which I am aware of as of now. So, the clause theorem I can now state the clause theorem once I have given this definition. So, the clause theorem a clause network strict sense non-blocking necessary and sufficient only if means it is sufficient if means it is necessary condition. So, both we have to prove necessity as well as sufficiency both this I have not stated earlier I only told this happened this will be there, but is it sufficient condition I have not mentioned that. If number of second stage switches r 2 is greater than or equal to I think you will should be able to appreciate this new expression it is for S C matrix switch remember it is a symmetric is a generalized formulation and I can write in particular that is what I have told you earlier for symmetric network m 1 is equal to n 3 is equal to n if n only if r 2 is greater than or equal to 2 n minus 1. So, that is the definition now formally I can just prove it because I have now pulse matrix I have pulse validity conditions everything there with me. So, let us use that and quickly prove it. So, at least we should be able to close with the clause theorem today. So, proof I am going to write it down I could have only spoken it out, but that is fine. So, let there be an input from switch a who wants to get connected to an output of switch b. So, how you will set up the connection you take the pulse matrix I think I can remove this particular stuff and the figure that will be required. So, there is something which is common here where I have to put the entry right b does not matter or you can put b dash also it is ok I am just putting a b. So, how you will set up the connection is by you take any middle stage switch and that entry has to be put here any middle stage switch I have to put an entry without violating the pulse matrix conditions ok. So, if I am able to find out an element a free element of free symbol from the middle stage switch which can be put without violating the thing I can always set up the connection ok. Now, you have to only figure out that in all possible scenarios you should be able to build up this and you will actually figure out that what I am doing. So, let me just you can actually note it down I think it is better to write because this text is not there anywhere else. So, for the people who are will be looking at the video recording this will be important you have the text other people do not have. So, connection is made by putting a middle stage switch entry in a b cell of pulse matrix that is what has to be done. I am not worried about now duplicated entries because if there is a multicasting entries will be repeated in a row. So, now when I am going to write this statement I will use a word distinct before the entries. So, if they are duplication one is being repeated three times I will still call only one distinct entry. So, that becomes very important ok. So, the previous statements when I have written that distinct word you have to always figure out whenever I write distinct what it means because you are going to even handle for the multicast. So, precision is very important here there can be at most because there is one input in switch A which is free which you are trying to connect. So, worst case scenario m 1 input ports must be busy m 1 minus 1 input ports must be busy. So, that actually means there can be at most m 1 minus 1 I am going to now put a word distinct to take care of multicast scenario now. Earlier I would have said m 1 minus 1 symbols would have been there at most m minus 1 distinct symbols can be there at most because in multicasting the symbols will repeat. So, number of symbols is not important number of distinct symbols is what is important ok. So, I am going to put a word distinct already in row A. So, this is equal to number m 1 inputs minus 1 input which wants to get connected m 1 inputs minus 1 input which wants to get connected using the same logic I can say that column B can have at most m 3 minus 1 symbols and worst to worst case. What can happen is this m minus m 1 minus 1 and this m 3 minus 1 distinct symbols they will always be distinct actually does not matter because there will not be any repetition in the column 2 and 4 conditions for the pulse matrix are always valid irrespective of whether it is unicast or multicast ok. So, total number of symbols in worst case scenario no symbol in m 1 minus 1 in this set and in this set there is no symbol which is common. So, there is a distinctness they are all distinct.  I think you can understand what I am doing because I am just writing whatever I have said earlier in the previous earlier lectures. So, these many total symbols are already occupied or busy if number of available symbols is going to be more than this you will be able to find one symbol one those the symbols which are not consumed here because if the number of available symbols are more than this there will be has to be some symbol which is available now and that symbol can be put in this cell and I can set up the connection and this can always be done this can always be done. Now, as far as the multicastry is concerned what actually probably instead of this I can further say that a has to connected to b and d somewhere. So, I have to put entries here same entry also should repeat here same entry should also repeat here. That is most important and then I can create a multicastry is for to catering for the multicast entries and symbols are same any symbol which is entered there that is what I am talking about otherwise a distinct entered symbol or distinct symbols is also fine not an issue this true even for multicastry closed theorem is true even for multicastry. So, this actually means R 2 has to be greater than m 1 plus n 3 minus 2 first wish to be strictly non-blocking which actually implies that R 2 has to be greater than equal to m 1 plus m 3 minus 1 I have put the equal to condition that is why I did one there and if it is symmetric case it becomes 2 m minus 1 because I am using m not n. So, it is 2 m minus 1. So, this is the same condition which I had told you earlier. So, you find out the worst case offset and then maximum overlap and based on that you find out and since this entry this new entry has not been used by neither in this column or in this column if you look at for D similarly you will be able to find out because D is also free in worst case offset you can find out always some entry which also can be put here. I need not put the same entry here and here remember if I am trying to set up a connection with D. So, whatever number of symbols which are used here and number of symbols which are used here worst case scenario will be m 1 minus 1 and n 3 minus 1 and whatever is missing that actually can be used here. I can even repeat the same symbol if it is available otherwise I will use some other symbol multicasting is enabled repetition is permit repetition actually means that. So, now let us that finishes with the clause theorem only thing the multicasting I will try to elaborate on that in the next lecture slightly more. I have only told about this as for unicast connection. So, let me also look into more into the multicast scenario specifically because that sufficiency and condition has not been still proven for multicast and then we will go for slip and do it theorem rearrange will be non block switch condition. If this condition currently is for unicast I have not told about anything about multicast, but this will be true even for multicast, but I have to formally prove it. So, I have to at least give an argument how it will be because you should actually ask a question m 1 minus 1 are occupied here there is exactly one extra entry which is free which you have used here already. These entries are there now question is it is possible that this particular entry which have been put here have already been used somewhere here, but then in that case the condition of distinctness between this and this will not be maintained there is something which is already common. So, that entry cannot be I have to just actually articulate that that articulation so far has not been done for multicast scenario. So, so far proof this strength only for unicast. So, we have to figure out whether this condition is going to be true for multicast or not. So, I also leave it to you because this is as of now till now whatever we have discussed it is only showing it for unicast multicast I have to give the case that it is always going to be possible. So, we will go further in the next class from here on.


and I realize even though I have not known it that when it comes to my uncle all their fears are the same and all their fears are terrible. Welcome to Church of the Chair where we love stories within stories. I'm your host E and today we're marrying a tiger. Today we're talking about The Tiger's Wife by Tia O'Brett. If I got that name pronunciation wrong I do apologize. The Tiger's Wife takes place over quite a long timeline but it is told in a first person close narrative about this woman who has become a doctor whose grandfather took her to the zoo all the time, shared loads of stories with her who he also was a doctor. There is so much to love about this book but I want to preface this with this is probably not going to be most of my viewers cup of tea. The reason for that is not much happens in the book it's very heavy on theme and it's kind of light on character. I didn't get much of a feel for the characters inner workings their inner thoughts it was more of and they weren't caricatures that's not what I'm getting at. What I'm trying to say is that she doesn't go deep into character development no one really changes throughout the course of the story and while we do follow the grandfather from nine years old all the way up until the point of his death we still don't have a good feel for him other than the way he interacted with other people and I like to get a little more about people than just what other people feel about them so it's not really a criticism for me I'm not taking off any stars it didn't hinder my enjoyment I absolutely love the book I'm going to give it five stars for those of you that don't want to hang around for the rest of the review but it is definitely literary fiction it won the national sorry it was a national book award finalist shortlisted back in 2011 um and it's just one of those books that I'm continuing my journey trying to read all of the national book awards finalists and winners this one this one feels like something special and I'm not quite sure how I'm going to get that across if you're a fan of books like The Gargoyle by Andrew Davidson and you love books with stories inside stories inside stories books that are basically a Russian nesting doll of stories you're going to love this book the reason I say that is not only do we get a first person narrative from the main character Natalia but we also get her grandfather's the flashbacks to her grandfather's uh early childhood his coming of age all the way up until the point of his death and on top of that we get the stories from the other villagers that were in the same little community as the grandfather you have multiple different perspectives but all told by that first person narrator which I really loved it gave this sense that I was just listening to someone tell a story about a story and I love stuff like that I'm a big Stephen King fan I'm a huge fan of The Gargoyle by Andrew Davidson and if you're into those kind of things definitely check this one out now I want to talk a little bit about what happens in the book right out the jump it opens up with Natalia going with her grandfather to the zoo and they see a tiger the tiger becomes a staple of the I don't want to say plot but the but the story revolves around the tiger and it's one point in time the tiger's wife which is not exactly it's not literal there is a woman who is married to a man and it is assumed that that man is killed by a tiger and the tiger hangs around after that so the villagers start calling her the tiger's wife there is also and this is the more important one throughout the entire story we're told about the deathless man a person that Natalia's grandfather had bumped into numerous times in his life they made a bet for a certain item and it's it's one of those things where it feels like death is is following this character and just waiting for its moment now I'm not saying that's exactly what happens but that's what it feels like it feels throughout the book like we are just counting down to the grandfather's death and of course he does pass away that's in the description of the book and that's also right where the book begins after the cold open with the flashback to the zoo that they went to and you the introduction to the tiger we flash forward into the grandfather's death and how no one knows no one knew that he was dying no one knew right off the bat where he had died and we are told through his life story what might have happened to him I really loved and enjoyed the concept and the execution of the death the deathless man I love the way he was put into the story but there's something I need to bring up don't expect too many twists and turns or or too many explanations this one is very much like night film it's going to leave you questioning quite a bit toward the end you can I love stories like this because then you can form your own opinion of what happened and that's what I believe tia o'bret did so well in this one was give you just enough information to put the puzzle pieces together but at the same time not everyone is going to come to the same conclusion as maybe I did or anyone else has I love books like that and that's one of the main reasons I'm giving this one five stars other than the story within a story aspect my personal favorite story within this story is the story of the blacksmith in fact I have a note in the back of the book that says chapter a chapter for the death of the blacksmith lol now even though I just told you that that character dies you're not going to see it coming I promise you that that's why I decided to say it right up front it was very very funny I got a kick out of it and there is a lot of subtle humor in this book especially in the dialogue between the deathless man and Natalia's grandfather crossroads are where the paths of life meet where life changes now while there isn't a lot of character development in this book there there is no growth of the characters it's pretty much a static image of these characters what they've been through stated plainly there is an awful lot of description of people places all of that especially when we enter a new place you get the entire painting of that area while sometimes I'm not in the mood for that type of thing I was definitely in the mood for this this time it's one of those stories that felt magical even though it is rooted in in realism while also having awesome themes and ideas like the deathless man and the tiger's wife at one point in time the villagers think of the tiger as the devil so we're jumping into superstition and all that and by the end of the book you are questioning what is real what is real and what is fable what is what is fiction and I love books like that also this one fired on all cylinders for me and I would love for you guys to read it but at the same time I would completely understand if all of you absolutely hated this book because it is slow there's not a lot of action but the themes are on point and I love a good message and this one had one that it was just chef's kiss in the end all you want is for someone to long for you when it comes time to put you in the ground what we don't get much of in this book is the reflection or the mourning of the grandfather after the main character finds out that the grandfather has passed away again it's not a spoiler it happens it's the it's the second chapter in the book and it's also mentioned in the back of the book so we don't get a whole lot as far as the character's feelings how the characters react to certain things and everyone in the book was rather dry and some some are combative some are you know just pacify the people they are talking to there is also a lot of odd interactions especially between the grandfather and the deathless man my favorite interaction in that vein was the deathless man is imprisoned at one point in time and the grandfather is talking to him through a door and I got I got a kick out of that just their dialogue back and forth so another thing I would say is if you love good dialogue this is this is definitely a book to pick up I loved the diggers every chapter with them in it was what it was very interesting and the little story there about the body that they're trying to find that was another high point for me and the more I think about it the more I talk about it the more once again this book is special to me it is that magic of storytelling when an author can make nothing happening interesting when they can make a story around no action no drama no real character development and kind of iffy pacing when you can keep my attention even though you have none of those things I gotta give the author credit but again I I completely understand if you guys read this book and are mad at me become mad at me because you know I told you to read it but just go in knowing what I have said go in for the themes go in for the mystery and magic of it all and just have a good time well that's all the time I have for you today sorry this review was a little all over the place but when I enjoy a book this much I don't know what to say without just giving you loads of spoilers if you're interested in a spoiler talk for this book I would love to do that for you but only if you guys want it so have you read the tiger's wife by Tia O'bret if you have let me know what you thought of it down there in the doobly-doo but until next time I'll hail the chair


Why today we talk about agriculture? In the near future, we have at least nine billion miles to feed. And the solution comes from farmers. In Asia, it means that small household farmers. There are too many problems in their future. They have to face with lack of infectious, lack of resource, poor support service, etc. And they have also to face with a lot of risks, come from the market, from the natural disaster, come from climate change, etc. How to help them to overcome those problems? What the most needed with the farmers in that region is empowerment for farmers themselves. What kind of power do they need? They need politics and power. They need economic power. They need social power. I think that government needs to support them through suitable policy and environment. Business associations need to help them through the building marketing channel, reduce the risk for them and improve the profit for them. What we have to do is changing the working conditions in rural area to be very attractive for new technology, for better living conditions, for higher income. And by that way, the young educated people can work effectively. I think that is the solution to feed nine billion miles into work with higher quality and also have a better life for our smart farmers.


The least advanced yet persistent threat that we're dealing with on a regular basis. Every time that I go to one of these, I can't tell you how many speakers end up talking about how the human element is the weakest link in our security apparatus. So I wanted to try to flesh that out a little bit. So I worked for an organization called Ideas 42. We were born out of a number of research institutions back in 2008 by academics who wanted to take insights from behavioral economics and psychology and apply them to real-world problems. As you can imagine, this is relevant for things like family planning and reproductive health, as well as energy, as much as it is relevant for cybersecurity. And I know what you must be wondering, why 42? Well, I can tell you, it's not because we only have 42 ideas. It is really because we're just big Douglas Adams fans. So for those of you who love Hitchhiker's Guide, we also love Hitchhiker's Guide. And we've been working over the past year to develop a deeper understanding of how human behavior and behavioral science can actually be applied within cybersecurity. And we've developed a narrative, a piece that pays tribute to Deep Thought, called Deep Thought, A Cybersecurity Story. You see small cards on your seats advertising. But it culminates our research within this space as we're trying to understand how we can bring behavioral science to bear on these significant problems. So before I continue, I want to be able to provide a bit of a framework for thinking about people's behavior and how we think about evaluating that behavior, the models that we use. So the easiest way for me to do this is to compare the way that we think about this to the way that a classical economist might. A classical economist assumes very much that human beings function kind of like this guy, Spock. They're rational beings. They're unemotional. They maximize their utility. They weigh all the costs and benefits before they act. And when they act, they do it with pure intention. We believe that we can impute people's intentions from their actions in this paradigm. But maybe we don't fully agree with this model. Maybe we think people act a little bit differently. Maybe we think people act more like this guy, Homer Simpson. Generally, a lovable doof enjoys donuts, maybe a little bit too much. Probably needs a very strong helping hand and helping him to follow through on the intentions that he may put forth. I would argue that we actually think about people quite differently. It's neither fully Spock nor is it fully Homer. It's more like this guy, Brad Pitt with a really gross beard. It's sort of an odd choice. And I bring this up because I think it's really important. The success of any product, policy, or proposal really rests on the behaviors of end users, the people who are going to be interacting with those products and services. And if we assume that those end users are going to be like Spock, we're going to design that thing in a specific way. If we think they're going to be like Homer, we may give them too much support. In reality, we should really be thinking about them kind of like Brad Pitt with a weird beard, generally smart, but making some strange decisions sometimes, and under certain circumstances. And that brings me to my other really important point about this, which is that it's really about understanding the context in which these actors are acting that's going to lead us to better insights about how we can design our solutions around them. Because the context matters the most, I think. So if we understand that sometimes people have intentions and sometimes they don't follow through, and maybe that has a lot to do with context, then we can start thinking about building better solutions for people. And what does this kind of look like? I think it looks like this. Now, I didn't find this, I didn't take this photograph, I can't take credit for it. But I think it's a really great example of this idea. People seem to want to work out, but in this context, they're going to take the escalator because it's seemingly the easiest path. It's the one of least resistance. But again, it's hard for us to impute what they want. Do they really want to work out or do they want the ease of the escalator? So you may be asking, what does this really have to do with cybersecurity? So let me just take a quick poll. Who believes that updating is a really important and critical way to protect our systems from bugs and persistent threats? Great. Now, keep your hands up if you said yes. Who amongst this crowd of people updates as soon as you get your update? Keep your hand up. So this is weird, right? Because one thing that we would assume about Spock is that if we told Spock that updating is important, that he would do it. And here I'm surrounded by experts in this space. I look around at your computers and you have stickers on your cameras. Some of you have VPNs that you use on a regular basis. And yet updating is still a persistent problem. Why? So we wanted to look at these sorts of problems. And I think that with updating it comes down to a few elements. It's a problem with the user interface. It's a problem with the choice architecture. If you're asked in the middle of something, do you want to update an hour later, you're probably going to say later. And you may do that not just for a few hours or a day, but for weeks on end. And when a threat is imminent, we don't have that time to wait. So what we set out to do is try to understand the vast array of different types of challenges in the space. And to try to understand what about the context is really causing people to do what we see them doing so that we can build better systems around them to get them to do what we want them to do. So as I said, we've been working on this big narrative. It's actually a novella. And as part of this release, we've developed a video which I'd love to show you right now. Are you next? Because in the time it takes you to watch this video, 12 cyber attacks will have occurred. And while many of the recent high profile attacks targeted information like emails, bank account credentials, and government employee data, some have shown how hackers can execute attacks of even greater consequence. Despite billions spent worldwide to build new technologies to prevent these attacks, cyber crime not only continues, but seems to have increased. Why? Well, most investments in cybersecurity go towards building more complex technology and bigger walls. But in doing so, we neglect the human beings who are at the center of these systems. While we might believe that rogue hackers pose the greatest threat to cyber security apparatus, experts estimate that 70 to 80 percent of the costs attributed to cyber attacks are actually the result of human error. Developers who unintentionally build errors into software, end users who procrastinate installing security updates and set bad passwords. IT administrators who neglect to manage access control permissions of employees and vendors, providing pathways to sensitive information. And C-level executives who don't always invest enough at the right time and in the right places. At Ideas 42, we use insights from behavioral science to understand human behavior. We believe the context matters and that awareness does not guarantee action. That we all have predictable biases and that we should focus less on how people should act or how we expect them to act or even how they intend to act, but how they actually act. And when it comes to cybersecurity, it means we realize that human behavioral factors present a rich vein of opportunity for making our system safer, more robust, and more resilient. Take a C-level executive, for instance. Classical economists believe that investment decisions a C-level executive makes comes from a careful weighing of the costs, benefits, and risks using all information available to them. Behavioral economists recognize that's not likely the case. Uncertain about the costs and benefits executives may simplify the question or take mental shortcuts. Instead of ensuring security, they change the question to, are we compliant? In determining whether additional investments need to be made, they may ask, did we have a breach this year? Choosing to invest only if the answer is yes and neglecting to consider they may have just been lucky. To improve investment decisions, we want to build tools that help executives cease our security, not as an investment, but as a key aspect of operations. We may need to reframe finding failures in cybersecurity systems as important successes and elevate cyber risk as a key risk area for organizations. But this is just the start. By turning the lens of behavioral science on various human challenges in cybersecurity, we can identify new opportunities and interventions to improve human behavior and security generally. To learn more about ideas 42 and behavioral science applications and cybersecurity, check out our new cyber novella and reach us at our website, www.ideas42.org. So I don't have a whole lot of time left, but I do want to talk about one other thing. Investment in cybersecurity is a really big issue, making sure that the executives who are making the decisions about provisioning these pieces of software, these infrastructures, they need to be able to do it in a way that's measured and is going to have success. But what we find is that if we just use the classical assumptions about how people make these decisions, we understand they're going to have to integrate a lot of information, calculate risk appropriately, and weigh the costs and benefits in order to decide how much will I invest in and what. But what we find is that it's actually really hard to do this in practice. Oftentimes, organizations, and this is something that we found through our research, don't even know what assets they have or where they exist. And if they don't know what they have and where it exists, how can they go about a measured way of responding? Well, in reality, they still respond, but they probably do it in weird ways. So for instance, they might use incorrect mental models about how to think about their security system. Is it a walled fortress that I'm actually trying to build? Is it a process that I'm trying to enact operationally? Or is it something else? Is it more like a network that I have to think about? They may substitute safety for compliance, thinking that if I just check all the boxes, if I apply this framework, it means that I'll be safe. But they may think about that in a static way, not as a process, not as a way of trying to evaluate on a regular basis, how we can improve that framework, how we can continue to check new boxes. And finally, we may find that some executives think about failure in an improper way. I think that we recognize that in order to be successful in building new cybersecurity infrastructure, we have to be finding failures on a regular basis. But if you've spent your entire career trying to show your successes, that might be a very strange thing to try to do. So what can we try to do to help people? Well, I think a lot of this is about building new tools to help these executives think about cybersecurity in the right kinds of ways. Provide them with mental models that are more true, maybe without boundaries. So they're not thinking about building a castle, but they're trying to manage a network of individuals across an open domain. Maybe we have to help them think about going from a checklist approach to a process-based approach. And maybe it's about actually embedding process in that checklist, so that they can't just check it off once and be done with it. And finally, maybe it's about actually trying to make failures your metrics of success. If you're finding new failures on a regular basis, you're probably doing better than if you aren't. But these ideas are not just to be used to bear on issues of investment and the C-level executive decisions. There are problems across the domain with all different types of users. People who build code, users who don't necessarily update. IT administrators who do have to manage access control permissions on a regular basis and provision these systems. And the C-level executives as well. So I encourage you, if you're interested, to please check us out. At ideas42.org. Today we've released the first two chapters of our novella. It's gonna be a serial release over the next three weeks. So it'll give you an opportunity to enjoy hopefully a good story and get some interesting analysis along the way. And if you're interested in learning more, please feel free to reach out to us. You can reach us at cyber at ideas42.org. I'll be around today. So if you have any questions, let me know. Thank you.


So hey guys welcome to come again if you're new make sure you hit the subscribe button and a little bell Comment below hit the like button. I mean even share with your friends Good job. We have cookies and milk might be seeming not sure All right guys welcome back to come again I'm gonna really reviewing figure that my wife just got me from my birthday Of course my birthday is on Monday the 13th of March So she went ahead and ordered me the Sherlock action figure from the hit BBC series starring Benedict Cumberbatch So as you'll notice the box is Pretty much a collector style box now John had a figure just like this at the shop When it was open however his was factory mistake The Benedict the Sherlock figure actually came packaged Upside down never opened Now however with me. I like to open the boxes. So I Never got it because I knew I was gonna open it. I didn't want to spend that much money on Something I was gonna open anyway So it didn't really make sense. So as you'll notice it has the door to Sherlock's apartment or his his flat as they call it over there 221 B Baker Street I'm a longtime Sherlock Holmes fan Even in grade school. I would read the old Sherlock Holmes books By sir Arthur Conan Doyle. I've just I've always been Intrigued by the character of Sherlock Holmes he's just He's an amazing character to get into we look at the side and you will see Benedict Cumberbatch in his Sherlock attire Pack includes a violin a Skull and a cell phone There's the back of the package The other side the top and the bottom then inside See nice packaging Benedict Cumberbatch as Sherlock Then a close-up of his face here and As quote I need you to maximize your visual memory And then we got John Watson on the side It is five inches tall. I was a little worried. I When I first discovered how tall it was I was a little worried it was going to be too small But I think it is really the perfect size I will get Measuring tape out here once I finish going over this guy and Measure it for sure to make sure it is exactly five inches tall So let's go ahead and take him out of his package and take a look. All right guys So as you can see The you do have to take little sticky tape round circular Tape off of it to open it however, once you do that It is very easy to keep if you want to Keep the box and display him in box You are able to do that nice little window box. I think I might keep this box. Just I Won't keep him in the box, but I will keep the box itself. I do like it secured by Velcro on the little flaps Very nice So let's go ahead and move this out of the way And we'll take a look at the figure. All right, so as you can see there is a little Cardboard piece for the background.  He is secured in by one rubber band and The rest are secured in with tape So let's go ahead and remove that Take him and the accessories out of the package We'll go over the accessories first and then we'll go over Sherlock himself So first things first we have the skull here Very nice detail Let me go ahead and move this change of lighting real quick So we got the skull here as you can see they did not skimp on the detail at all You got hollowed out eye sockets Got the hollowed out nose slightly not completely hollowed out, but you can tell it's got depth Get the mouth and the teeth each tooth is sculpted Very nice sculpt and paint job to the skull got the temple sculpt Done very well got the nice Sculpt from where this skull itself actually fuses together right there Nice sculpt of where the spine attaches to the skull And the jawline Very nice paint job as you can see here It is a brown and darker a light brown and dark brown to give it a very realistic look. I Really like it a lot. Go ahead and set that to the side there We'll take a look at his cell phone now all right Cell phone it Does look like I think it's a blackberry it could be wrong Not a lot of detail. They do have the keypad there and then They could have added a little bit to the screen Maybe a sticker or something on there Would look good But as it stands it just looks like a black flat piece of plastic very thin Probably very easy to lose. I Know I've almost dropped it quite a few times So there's the cell phone and the skull Here is his violin as you can see each string Does appear to be Sculpted on there. They didn't do too good of a job on the branding marks the violin I Know those I don't think they're supposed to be Branding marks. I think those are actually supposed to be openings for the acoustics of the violin But even so Not really as Sharp looking as they could have been very nice brown paint job dark brown With as much detail as they put into the skull I really wish they could have put a little bit more detail into this file in maybe Doing a little bit better paint job on the strings Or for the strings to make them stand out a little bit more but overall not bad It is a softer plastic So you don't really have to worry about breaking it too easily kind of that gummy plastic at least on the neck The body is a little bit thicker, but I think it's the same gummy plastic just thicker Now let's take a look at the bow once again It is that really gummy plastic They could have probably done a little bit better job with this as well it just looks like a Stick pretty much With two different shades of brown So there's that part now. Let's go ahead and take a look at Sherlock himself you will notice he has his scarf It is the blue and striped scarf and it does move. It's not actually a Part of the sculpt. It's actually separate It looks like they put it on and then put the head on The jacket is made up of a softer plastic Very soft very flexible The sculpt just looks amazing they got all that detail in there All the folds increases to the jacket the buttons on the back The sculpt to the hair looks amazing and it does relative look pretty much like Benedict Cumberbatch It does look like the upper part of the jacket is Completely glued on to them so it only it only moves from the waist down Which isn't really a big deal They could have however made it to where you could take the scarf off That would have been nice. I think he could have gotten a lot more rotation out of his head without the scarf as Is his head moves about that far on each side I think if it weren't for the scarf, he might be able to go further But You know what it's a really good likeness, so and his arms do go All the way around there is a bicep swivel But they do not go out and you got the bicep swivel on both sides you got the Elbow joint it is just a single ball joint or a single Standard joint elbow joint. Well, you can see that. Let me bring it close.  However, you don't get too much movement out of it It can move slightly Around like a ball joint It can turn Let's take a look at the sculpt on the hands. The hand sculpt isn't that bad really Very nice hand sculpt. They could have put in a little bit better paint job for shadow casting on the fingers But overall not bad Same way with this side Now we move down to the legs Bring his arms up real quick He does have waist swivel. You can turn all the way around It is just a little bit cumbersome because cumbersome cumber batch is cumbersome But it is very cumbersome because of the jacket Difficult the legs do move all the way out or If the jacket wasn't in the way anyway, let's see here bring the jacket up and The legs do go pretty far out You get that nice blowing motion of his jacket. It doesn't stay up like that though Let me let me put that up again so you can see the Articulation a little bit better. All right, so once again The waist swivel the legs they do go Up that far back that far, but they do go pretty far out Then you got the thigh swivel All the way around on both legs you got a standard knee joint and It looks like no No foot articulation But it does look like they may be a separate piece. So maybe they just glued in there But overall not bad. Let's see how well Put the Ellen in his hand So you can't tell does appear he's right-handed he's got his Violin in his left hand with the bow which I believe Goes like this in his right hand, which I believe is very show accurate In fact, most musicians you will find are Right-handed that's why the majority of instruments are made for right-handed musicians As a musician myself, I play guitar base I can hold my own with drums and I used to be able to play the piano quite well. So There you go. He holds it pretty well I doubt you'd be able to get a whole lot of the Violin motion or violin playing motion out of the other hand Simply because of the articulation Not as bad thing But nonetheless, you're not gonna get You're not gonna get a lot of violin playing motion out of it This will probably just go right up on my shelf with my other collectibles It'll actually probably go on my McFarland shelf because it does remind me of a McFarland toys figure even though it appears It's done by underground toys Yeah Underground toys So now let's see here. Yeah, we did the violin Let's see. He's right-handed. So his cell phone would go in his right hand as well I guess it fits in there. Okay. It slides in. I don't know who would hold their cell phone like that but you know See how it is in the other hand It does not fit in his other hand. He does stand up very well and And yeah, I'm pretty happy with this figure. I really like the details. I I think they did a great job They could have made his articulation a little bit better Like I said, they could have made it to where the scarf was removable so that we'd get a little bit more articulation out of his head The way Benedict Cumberbatch moves on the show they could have done Double elbow joints and double knee joints and could have probably gone with ankle joints and rockers as well but overall I'm pretty happy with it. I can understand why they didn't go with the ankle joints or rockers because the pant legs I Have seen especially on McFarland toys where the ankle Rockers It will be a little bit more flimsier and cause The figure not to stand as well But this figure has no problem standing at all So overall, I'm gonna give this guy probably an eight out of ten Go out to your local comic book shop your local collectible shop Amazon eBay So yeah, there he goes guys BBC's Sherlock action figure. Oh, yeah, I'll be right back. Let me go get my Measuring tape and I will measure him have my handy dandy Measuring tool here he does actually stand About a little over five and a half inches Not exactly five inches tall a little bit more Which is nice because as you can see He'd look very short if he were exactly five inches So I am pleased that he's not exactly five inches tall The box itself Is seven and a half inches tall So it it it's gonna make a nice display piece. It really is it's not gonna be too big It will fit in very well with my McFarlane collectibles my Walking dead Daryl Dixon on his motorcycle as well as my assassin's creep figures. There you have it guys BBC and underground toys Benedict Cumberbatch Sherlock Action figure I'm really glad my wife got this for me for my birthday. Like I said, he's gonna go right up on my shelf And probably gonna stay there so I don't lose any of the pieces and I'll probably put the box In my closet somewhere hang on to it So take care guys. Hope you enjoyed this review. Hit that subscribe button. Make sure you hit the like