Years ago I recall reading a story by, I think, Isaac Asimov. Its central theme was phone exchanges becoming sentient.  Does anyone know what I am thinking about or am I dreaming and should quickly write this story?
I am looking for a short story I read long ago about the phone system 'waking up'. It talks about how the phone system had just reached the number of connections as the number in the human brain. They lead you somehow to wonder (maybe characters speculating?) and it ends with a 'baby cry' of all the phones in the world ringing. I think I read it at least 20 years ago, maybe as many as 30. I think it was after 1978 because I think it was after I went to work at Bell Labs - so the phone connection resonated:-). It was definitely pre-internet.   What was the title? Who was the author? Any more on the plot since my memory is very hazy? I remember really liking the story and this site has got me thinking about my ATF's.
Find the remainder of $\dfrac{2^{2014}}{7}$   I am new to the modular arithmetic, Any suggestions to solve this question? When performing k-fold cross validation, I understand that you obtain the accuracy metrics by pointing all the folds except one at that one fold and make predictions, and then repeat this process $k$ times.  You can then run accuracy metrics on all of your instances (precision, recall, % classified correctly), which ought to be the same as if you calculated them each time and then averaged the result (correct me if I'm wrong).  The end result you want is a final model.  Do you average the models obtained to make your set of $k$ predictions to end up with the model that has the accuracy metrics obtained by the above method? Why is a nonstop flight sometimes more expensive than multiple connections? Usually I find a flight I like that uses one or more connections with the same or different companies. In these cases, if the distance between the first and the second connection is not too large, I prefer to go by bus or train and then take the flight. The problem is that sometimes it is more expensive to take the flight in the second airport than to take the flight from the first one. I mean, I'm wondering why sometimes it is more expensive to take only a flight than to take the same flight and another one.  A practical example (and real, you can check with SkyScanner). Imagine I am in Madrid (Spain) and would like to go to Rio de Janeiro (Brazil) on April 1st. The cheapest flight I have found is this:     TAM airlines: MAD -> GRU -> GIG : 507 €   Fantastic! GRU is one of São Paulo's airports. That's perfect for me! I'll go on to Rio traveling overland. But then, I look for this flight (MAD -> GRU, non-stop):     TAM airlines: MAD -> GRU : 597 €   It's the same flight, 90 € more expensive! I've found this kind of behavior a lot of times and I'm intrigued to know why it happens. Continuous footnote numbering I would like footnote numbering to continue over pages and chapters. In my document it's reset every chapter. I'm using the report documentclass. PostGIS nearest points with ST_Distance, kNN I need to obtain on each element on one table the closest point of another table. The first table contains traffic signs and the second one the Entrance Halls of the town. The thing is that I can't use ST_ClosestPoint function and I have to use ST_Distance function and get the min(ST_distance) record but I am quite stuck building the query.  CREATE TABLE traffic_signs (   id numeric(8,0) ),   "GEOMETRY" geometry,   CONSTRAINT traffic_signs_pkey PRIMARY KEY (id),   CONSTRAINT traffic_signs_id_key UNIQUE (id) ) WITH (   OIDS=TRUE );  CREATE TABLE entrance_halls (   id numeric(8,0) ),   "GEOMETRY" geometry,   CONSTRAINT entrance_halls_pkey PRIMARY KEY (id),   CONSTRAINT entrance_halls_id_key UNIQUE (id) ) WITH (   OIDS=TRUE );   I need to obtain the id of the closest entrnce_hall of every traffic_sign.  My query so far:  SELECT senal.id,port.id,ST_Distance(port."GEOMETRY",senal."GEOMETRY")  as dist     FROM traffic_signs As senal, entrance_halls As port        ORDER BY senal.id,port.id,ST_Distance(port."GEOMETRY",senal."GEOMETRY")   With this I am getting the distance from every traffic_sign to every entrance_hall. But how can I get only the minimun distance?  Regards, Is there a way to get the path for the assembly in which the current code resides?  I do not want the path of the calling assembly, just the one containing the code.   Basically my unit test needs to read some xml test files which are located relative to the  dll.  I want the path to always resolve correctly regardless of whether the testing dll is run from TestDriven.NET, the MbUnit GUI or something else.  Edit: People seem to be misunderstanding what I'm asking.  My test library is located in say      C:\projects\myapplication\daotests\bin\Debug\daotests.dll   and I would like to get this path:     C:\projects\myapplication\daotests\bin\Debug\   The three suggestions so far fail me when I run from the MbUnit Gui:   Environment.CurrentDirectory gives c:\Program Files\MbUnit System.Reflection.Assembly.GetAssembly(typeof(DaoTests)).Location gives C:\Documents and Settings\george\Local Settings\Temp\ ....\DaoTests.dll System.Reflection.Assembly.GetExecutingAssembly().Location gives the same as the previous. Simple example of non-arithmetic ring (non-distributive ideal lattice) Can anyone provide a simple concrete example of a non-arithmetic commutative and unitary ring (i.e., a commutative and unitary ring in which the lattice of ideals is non-distributive)? At  there is this "only in ubuntu" that says "Built in virus protection":  What is the Ubuntu built it protection? What is the program in charge of this and how does it work? Workaround for Android 4.4 not being able to write to SD cards? Jquery .click not firing How to use exclamation marks in Minecraft commands? I know that you can use exclamation marks in Minecraft commands to check for an entity that does not have a specific tag. For example, you can use /kill @e[type=!Player] to kill all entities except for the player. I have, however, encountered two problems with using exclamation marks that I can't find a solution for.  For my first problem, I've set up a series of command blocks to summon shootable fireballs above the player’s head when a certain item is being held;  /scoreboard players add @a Fireball 1 {SelectedItem:{tag:{display:{Name:"Summon Fireball"}}}} /execute @a[score_Fireball_min=1,score_Fireball=1] ~ ~ ~ /summon Fireball ~ ~2.5 ~ {direction:[0.0,0.0,0.0]} /scoreboard players set @a Fireball 0   I used a comparator and a redstone torch so that the last command would activate when the first command would deactivate, that is, when the player is not holding the item.  The problem is, that when I move far away from the setup, the redstone stops working, leaving me unable to summon any new fireballs. Instead, I'm trying to use a command block to check when anything except for item is being held;  /scoreboard players set @a Fireball 0 {SelectedItem:{tag:{display:{Name:!"Summon Fireball"}}}}   I’ve either put it at the wrong place, or you simply can’t use exclamation marks in NBT tags. Could someone tell me where I should put the exclamation mark, or in the latter case, how I can check for anything except for a specific item?  Further, I’ve tried using exclamation marks to set the score of all entities, including the ones with a blank score, but except for the ones with a score of 2 or higher, to 0;  /scoreboard players set @e[score_arrows_min!=2] Arrows 0 /scoreboard players set @a Arrows 1 {SelectedItem:{tag:{display:{Name:"Rain of Arrows"}}}} /scoreboard players set @e[type=Arrow] Arrows 2 {inGround:1b}   The code does change the scores of entities without scores to 0, but it doesn’t exclude the arrows with a score of 2. Could anyone tell me what I’m doing wrong here? What and where are the stack and heap? Programming language books explain that value types are created on the stack, and reference types are created on the heap, without explaining what these two things are. I haven't read a clear explanation of this.  I understand what a stack is. But,    Where and what are they (physically in a real computer's memory)? To what extent are they controlled by the OS or language run-time? What is their scope? What determines the size of each of them? What makes one faster? Is there a known well ordering of the reals? So, from what I understand, the axiom of choice is equivalent to the claim that every set can be . A set is well ordered by a relation, $R$ , if every subset has a least element. My question is: Has anyone constructed a well ordering on the reals?  First, I was going to ask this question about the rationals, but then I realised that if you pick your favourite bijection between rationals and the integers, this determines a well ordering on the rationals through the natural well order on $\mathbb{Z}$ . So it's not the denseness of the reals that makes it hard to well order them. So is it just the size of $\mathbb{R}$ that makes it difficult to find a well order for it? Why should that be?  To reiterate:   Is there a known well order on the Reals? If there is, does a similar construction work for larger cardinalities? Is there a largest cardinality for which the construction works? Is there a free program to (batch) change photo file's date to match EXIF? I want to specify a directory and have the software find all the photos in the directory and its sub-directories, and if they contain EXIF date/time, it sets their filesystem timestamp to match the EXIF. I understand if I boot from a live cd  I can see all the system logs under System > Administration > File Log Viewer   I have a major error with a disk not mounting and I want to trace i tback to the last time it did work and what may have corrupted the ext4 filesystem on it.  So within the File Log Viewer Where do I start examining? I am looking for a correct proof of this statement: If $G$ is a group such that $G/Z(G)$ is cyclic, then $G$ is commutative.  Proof: $G/Z(G)$ is isomorphic to $\operatorname{Inn}(G)$ and is cyclic, and then for every $a$ and $b$ in $G$ the inner isomorphisms $\gamma_a$ and $\gamma_b$ satisfy $\gamma_a \gamma_b = \gamma_{ab} = \gamma_{ba} = \gamma_b \gamma_a$, and therefore for every $a,b \in G$, $ab = ba$.  Is that proof complete, or am I missing something? Thanks a lot for the help. Terminal not displaying colors for directory listings Local polynomial regression: Why does the variance increase monotonically in the degree? How can I show that the variance of local polynomial regression is increasing with the degree of the polynomial (Exercise 6.3 in Elements of Statistical Learning, second edition)?  This question has been asked  but the answer just states it follows easliy.  More precisely, we consider $y_{i}=f(x_{i})+\epsilon_{i}$ with $\epsilon_{i}$ being independent with standard deviation $\sigma.$  The estimator is given by  $$ \hat{f}(x_{0})=\left(\begin{array}{ccccc} 1 &amp; x_{0} &amp; x_{0}^{2} &amp; \dots &amp; x_{0}^{d}\end{array}\right)\left(\begin{array}{c} \alpha\\ \beta_{1}\\ \vdots\\ \beta_{d} \end{array}\right) $$ for $\alpha,\beta_{1},\dots,\beta_{d}$ solving the following weighted least squares problem $$ \min\left(y_{d}-\underbrace{\left(\begin{array}{ccccc} 1 &amp; x_{1} &amp; x_{1}^{2} &amp; \dots &amp; x_{1}^{d}\\ \vdots\\ 1 &amp;  &amp;  &amp;  &amp; x_{n}^{d} \end{array}\right)}_{X}\left(\begin{array}{c} \alpha\\ \beta_{1}\\ \vdots\\ \beta_{d} \end{array}\right)\right)^{t}W\left(y-\left(\begin{array}{ccccc} 1 &amp; x_{1} &amp; x_{1}^{2} &amp; \dots &amp; x_{1}^{d}\\ \vdots\\ 1 &amp;  &amp;  &amp;  &amp; x_{n}^{d} \end{array}\right)\left(\begin{array}{c} \alpha\\ \beta_{1}\\ \vdots\\ \beta_{d} \end{array}\right)\right) $$ for $W=\text{diag}\left(K(x_{0},x_{i})\right)_{i=1\dots n}$ with $K$ being the regression kernel. The solution to the weighted least squares problem can be written as $$ \left(\begin{array}{cccc} \alpha &amp; \beta_{1} &amp; \dots &amp; \beta_{d}\end{array}\right)=\left(X^{t}WX\right)^{-1}X^{t}WY. $$ Thus, for $l(x_{0})=\left(\begin{array}{ccccc} 1 &amp; x_{0} &amp; x_{0}^{2} &amp; \dots &amp; x_{0}^{d}\end{array}\right)\left(X^{t}WX\right)^{-1}X^{t}W$ we obtain $$ \hat{f}(x_{0})=l(x_{0})Y $$ implying that  $$ \text{Var }\hat{f}(x_{0})=\sigma^{2}\left\Vert l(x_{0})\right\Vert ^{2}=\left(\begin{array}{ccccc} 1 &amp; x_{0} &amp; x_{0}^{2} &amp; \dots &amp; x_{0}^{d}\end{array}\right)\left(X^{t}WX\right)^{-1}X^{t}W^{2}X\left(X^{t}WX\right)^{-1}\left(\begin{array}{ccccc} 1 &amp; x_{0} &amp; x_{0}^{2} &amp; \dots &amp; x_{0}^{d}\end{array}\right)^{t}. $$ My approach: An induction using the formula for the inverse of a block matrix but I did not succeed.  The paper  by D. Ruppert and M. P. Wand derives an asymptotic expression for the variance for $n\rightarrow\infty$ in Theorem 4.1 but it is not clear that is increasing in the degree. Do virtual particles actually physically exist? Can you trade Pokemon from 7th gen (Sun/Moon) to 6th gen (XY, ORAS) and back? Title says it all, I don't see confirmation in  and a cursory google search seemed to say assume no and speculate about the pokemon bank.