Multiple instances of same device on I2C bus

I am currently designing a board where I need to include a whole bunch of I2C devices. Since the number is quite high, address clashing is an issue, that of course we can solve implementing different bus segments, or with translators.  There is a particular situation though, where I had an idea.  I have two arrays of 8x, and I want them to be configured in the exact same way. The I2C-compliant solution is to use a bus isolator, or an address translator, and get over it, but I was wondering if it is advisable to just hook them all to the same bus, and hope for the best.  To abstract a bit:  I have two identical devices, with an I2C slave interface, with the same address. I want to send them the same packets, in the same order and so on. Can I just connect SDA and SCL in parallel, and get away with it?  I do not need to read from the devices, and I am aware that a NACK would be hidden. Also, the devices do not support clock stretching.  Edit, to clarify some comments:  Yes, I do not care if a device stops working and understand I have no way of knowing  The master we are using does not resend data on a NACK, but raises the error to the host.  The board we are designing is meant to be used in an electronics lab environment, as a support to evaluate a product that my company is making. We expect to make ~20 boards, no mass production, no board will be sent to a third party.


I am aware of how to make an object glow, however, I am unable to figure out how I make the red part of this sword glow red.


Prove that $\gcd (a, b) = \gcd (a, b + xa)$ for any $x \in \mathbb{Z}$.

is a possible duplicate, but I don't understand the answers.   Let $a, b, c \in \mathbb{Z}$. Prove $\gcd (a, b) = \gcd (a, b + xa)$ for any $x \in \mathbb{Z}$.   This is my definition of the $\gcd$: The greatest common divisor of integers $r$ and $s$ is an integer $t$ such that 1. $t \mid r$ and $t \mid s$ 2. For any integer $u$, if $u \mid r$ and $u \mid s$, then $u \mid t$.   I have a few  questions about proving this. To do it, do I suppose that $t = \gcd (a, b + xa)$ and then show that $t = \gcd (a, b)$. Will I be done then? Or do I need to do that and also suppose $t = \gcd(a, b)$ and then show that $t = \gcd(a, b + xa)$? (I don't think that is necessary, but I want to make sure. I think I am getting confused with proving $A \iff B$)?   I am also confused with the wording "for any $z \in \mathbb{Z}$." Does for any mean for all $z$? Or does it mean that $z$ is fixed?  Here's my attempt: Suppose $t = \gcd(a, b + xa)$. Then $t \mid a$ and $t \mid (b + xa)$ and so $a = tj$ and $(b + xa) = tk$ for some integers $j$ and $k$. Thus $b = tk - xa = tk - tja = t(k - ja)$. Thus $t \mid b$. Suppose $u$ is an integer such that $u \mid a$ and $u \mid b$. Then $a = u \alpha$ and $b = u \beta$ for some $\alpha, beta \in \mathbb{Z}$. Since $t = \gcd(a, b +xa)$, we have that $t = am + (b + xa)n$ for some integers $m$ and $n$. Then $t = am + bn + xan = u \alpha m + u \beta n + u x \alpha n = u(\alpha m + \beta n + x \alpha n)$. Thus $u \mid t$ and so $t = \gcd(a, b)$.   I said earlier that I am not sure if I need to conversely suppose that $t = \gcd (a, b)$ and show that $t = \gcd (a, b + xa)$. I will go ahead and work on that proof so in case it is necessary, I can get some feed back. (Or an explanation on why it is redundant.)  Suppose $t = \gcd(a, b)$. Then $t \mid a$ and $t \mid b$ so $t \mid (yb + xa)$ for all $x, y \in \mathbb{Z}$. Taking $y = 1$, we have that $t \mid (b + xa)$. Suppose $u \in \mathbb{Z}$ such that $u \mid a$ and $u \mid (b+xa)$. Then $a = u \alpha$ and $b + xa = u \beta$. I'm stuck on showing that $u \mid t$. I know I can write $t = am + bn$ for $m, n \in \mathbb{Z}$, but I can't figure out how to show that $u \mid t$.


I need to inspect and repair a Raspberry Pi SD card. This is my main goal. And it should be as simple as possible. It's already bad enough that Windows 10 cannot mount that file system and Android also has no idea about it (but creates random junk on the volume it understands). So I got an Ubuntu disk image and started the live system in VMware. I thought this should be the easiest and quickest solution to get to an environment that can handle a Linux file system.  I plugged in the card reader and it showed up as two volumes on the Ubuntu live desktop as expected. But the file I need to edit belongs to root. The default graphical text editor (it has no visible name) that is started from the default graphical file explorer (also has no visible name) only opens the file as read-only. Saving is not possible.  Smart Windows applications ask me for the required privileges when I want to use them. (Dumb Windows applications still don't.) I thought Linux apps were that smart before. But the editor isn't.  So what are my options to edit that file?  Is going to a terminal and using all the funny text UI tools all I can do now? I'd really prefer a GUI solution because I always forget terminal commands after not using them for a month. And the mount path seems to be unreadable for humans, it's so long I can't see it completely. I found the command gksudo nautilus somewhere around but it's not available on my system.


deleting the specific file in a directory and all sub directories

Am using this code for deleting the specific file in all directories and sub directorates in a drive but its not working. please help me in this regard. If i want to delete the specific file in all drives how to do.      static String refile= "input.txt";       public static void deletemyfile(File directory) {     if (directory.exists()) {            File[] files = directory.listFiles();            if (null != files) {                  for (int i = 0; i < files.length; i++) {                         System.out.println(files[i].getName());                         if (files[i].isDirectory()) {                                deletemyfile(files[i]);                          } else  {                               String temp ;                             temp = files[i].getName();                                                           if (temp==refile){                              System.out.println("name matched and about to delete");                              (files[i]).delete();                           } else{                              System.out.println("name not matched");                         }                            }                  }            }     } else {System.out.println("wrong path");     }   }


I have gfortran installed on my system and the file libgfortran.a can be found at /usr/lib/gcc/x86_64-linux-gnu/4.6/. Using nm I made sure that the function _gfortran_compare_string is defined in there:  $ nm /usr/lib/gcc/x86_64-linux-gnu/4.6/libgfortran.a | grep _gfortran_compare_string   Returns  0000000000000000 T _gfortran_compare_string 0000000000000000 T _gfortran_compare_string_char4   But, the linker of my CUDA-C program throws errors:  /usr/local/cuda-6.0/bin/nvcc --cudart static -L/usr/lib/gcc/x86_64-linux-gnu/4.6 -L/home/chung/lapack-3.5.0 -link -o  "pQP"  ./src/pQP.o   -lgfortran -llapacke -llapack -lcublas -lblas -lcurand nvcc warning : The 'compute_10' and 'sm_10' architectures are deprecated, and may be removed in a future release. /home/chung/lapack-3.5.0/liblapack.a(ilaenv.o): In function `ilaenv_': ilaenv.f:(.text+0x81): undefined reference to `_gfortran_compare_string'   and later on another error, again related to libgfortran:  /home/chung/lapack-3.5.0/liblapack.a(xerbla.o): In function `xerbla_': xerbla.f:(.text+0x49): undefined reference to `_gfortran_st_write' xerbla.f:(.text+0x54): undefined reference to `_gfortran_string_len_trim' xerbla.f:(.text+0x66): undefined reference to `_gfortran_transfer_character_write' xerbla.f:(.text+0x76): undefined reference to `_gfortran_transfer_integer_write' xerbla.f:(.text+0x7e): undefined reference to `_gfortran_st_write_done' xerbla.f:(.text+0x87): undefined reference to `_gfortran_stop_string'   But, again using nm, I found that _gfortran_st_write, etc are defined in libgfortran.a.  Links:  and .  Note: Lapack makes use of libgfortran. I recently installed lapack and ran all the tests and they all passed.


Immortality loop-hole - Hide horcrux inside Fidelus-protected building/place

According to canon, is there anything preventing one from concealing one's Horcrux inside a building/place and then simply protecting it with the Fidelius charm, with one being the one and only secret-keeper?  It seems huge flaw to me that V allowed his Horcruxes to be found (and eventually destroyed) that easily. Especially the ring and locket. They were both in some kind of rooms. Using the Fidelius charm would make them simply unobtainable, thus making big V REALLY immortal.


Deleted .aae files and my photos are gone, how to restore, Help Please

I deleted .aae files by mistake and all of my related photos are gone. How do I recover these missing photos?  iPhone 6, iOS 9.2.1


Why Ridge regularization has the grouping effect

I want to use elastic net (lasso + ridge) method for feature selection process. I can't understand why does the ridge method gives me the grouping effect for correlated variables. Can anyone explain that please?


Vector potential in presence of monopole

In this paper  when Song was explaining dirac string. He said "In the presence of a magnetic monopole, the vector potential cannot be defined everywhere. Thus, to describe the physics of magnetic monopoles, we must use two vector potentials A1 and A2 which are related by a transformation."    Why is it that we must use (at least) 2 vector potentials?  And in what way are they related by a transformation? (P. 52 on the right hand side column)


How often can a U.S. passport holder exit/enter Morocco?

Does anyone how many times a year one can enter and exit and RE-ENTER Morocco as a United States passport holder? For instance, Schengen countries have the 90/180 rule. I've looked everywhere for the information and there is nothing out there, making me think it's a non-issue, but I'd like to make sure!


I am using TreeBidiMap from the  library. I want to sort this on the values which are doubles.  My method is to retrieve a Collection of the values using:    Collection coll = themap.values();   Which naturally works fine.  Main Question: I now want to know how I can convert/cast (not sure which is correct) coll into a List so it can be sorted?   I then intend to iterate over the sorted List object, which should be in order and get the appropriate keys from the TreeBidiMap (themap) using themap.getKey(iterator.next()) where the iterator will be over the list of doubles.


I'm really struggling on this question.  I've thought about it for a long time now but I can't seem to figure it out.  I know I am supposed to use the Mean Value Theorem in $[0,h]$ with $h>0$ and use the Mean Value Theorem in $[h,0]$ with $h<0$.   Attempt: I applied the definition of mean value Theorem for both of these and get:  There exists c such that $f'(c)=f(h)-f(0)/h$.  There exists d such that $f'(d)=f(0)-f(h)/-h$.  $f'(c)$ clearly equals $f'(d)$, which implies c=d=0.  Thus f'(0) exists.  I'm not sure if this is correct, but how would I conclude it equals L?  I know that there is some theorem that $f\in C[a,b],  $  f is differentiable in [a,b).  Then if $\lim\limits_{x \to a+} \ f'(x)\in R$, then $L=f'(a)$.    I think then the fact given in the question that $\lim\limits_{x \to 0} \ f'(x)\ =L$, would imply that $f'(0)$ equals L from this theorem, and hence we are finished.  Is this correct?  I'm not sure if I did it correctly, but have given my best attempt.  Any help would be much welcomed.


How can I keep muted when unplugging headphones?

I have this workflow:   Listen through headphones Press mute button on my keyboard Unplug my headphones to move away   I noticed that at least on GNOME, audio keeps playing.   How can I configure this mute button to keep muted after unplugging headphones?


Are the following two assertions always true, always false or meaningless?  $\exists i \in \emptyset$  $\forall i \in \emptyset$  Because it seems that one encounters expressions of this kind fairly similar in mathematics, especially if we are dealing with degenerate cases of definitions. Let me give an example (in graph theory) of such a case. There, one can formalize the idea the  two vertices are connected in the following way: Let $G=(V,E)$ be a graph and let $v,w\in V $. We define $v$ and $w$ to be "connected" if: $\exists n \in \mathbb{N}, \ \exists \alpha: \left\{ 1,\ldots,n \right\} \rightarrow V, \ \alpha_0=v \ \& \ \alpha_n=w \ \ \forall i\in \mathbb{N}, 0\leqslant i \ \& \ i<n:\  \left\{ \alpha_i, \alpha_{i+1} \right\} \in E$  Now, if we would ask, if every node is connected to itself (a fact which intuitively we would want to be true), we would have to exhibit an $n$ and a sequence $\alpha$, such that [bla bla...]. The obvious choice for $n$ is 0. But for this choice of $n$, no mattter which sequence $\alpha$ we would consider, the set of the $i$'s would be empty, because the set of the $i$'s is actually $\left\{ i\in \mathbb{N} |  0\leqslant j \ \& \ j<n \right\}$. But for $n=0$ this set is the empty set. Thus, because we quantify $\forall i \in \left\{ i\in \mathbb{N} |  0\leqslant j \ \& \ j<0 \right\}=\emptyset$, should the statement be true/false by definition?  EDIT: Sorry, for my unclear formulation and to everybody who on my fault interpreted it wrongly. The way Carl Mummert or Listing interpreted it, was what I meant.


Use shell variable inside a pattern in awk

I have a text file with tab-separated columns which I'd like to process using awk. Here's an example of such a file: size=1\tname=foo\tweight=1.2 weight=2.5\tname=bar\tsize=2  What I want to achieve is to normalize the numeric value in columns whose content is like $field_name=<number> to four decimal places and keep the rest as is. Here, $field_name is a shell variable that is passed to awk and I'd like to use its value inside a regex. Here's a snippet (which is not working of course). I'm particularly interested in fixing line #5 in the following awk script and not solutions using other tools, such as sed, perl, python, etc. $ cat "${file}" \                                       # 1     | awk -F "\t" -v field_name="${external_var}" '     # 2       {                                                 # 3         for (i = 1; i <= NF; i++) {                     # 4           if ($i ~ /$field_name=[0-9]*.?[0-9]+/) {      # 5             split($i, kv, "=")                          # 6             $i = sprintf("%s=%.4f", kv[1], kv[2])       # 7           }                                             # 8         }                                               # 9         print $0                                        # 10       }'


About 2 years ago, I wrote some VERY bad questions which obviously got down voted and one question just got closed off because it was irrelevant or because the question was not clear.   Recently, I wanted to have the privilege to be able to ask questions again. I decided to contribute positively to the community by answering questions where I can and I have been a bit successful. I managed to double my reputation points.   Now what I don't understand is, I want to be able to improve the questions I asked two years back but those questions are relevant to me anymore nor do I remember the problems not I have the code. I just don't know what to do about this. I know I cannot delete them, because it will make it worse.  Can someone please, tell me what I can do about these questions?   I hope I don't downvoted and I am aware there are probably duplicate questions. I just want some help.  MY question is unique because it mentions I am trying to improve my existing posts but they are irrelevant and I dont remember the problems nor do I ahve the code anymore.  Thanks,


Google Chrome 41.0.2272.118, Ubuntu 14.04    This is the second time I have had this error in the last week or so. Is this a bug on my part, or is there something up with the SE security certificate?  I've changed to bug because of :     No, it's something Stack Exchange would have to fix. Chrome is following the rules. But considering the whole meta.*.stackexchange.com dilemma is what's been holding up a lot of the HTTPS support, I doubt they're going to come up with any kind of fix for the www.*.stackexchange.com redirect problem. –  animuson♦


How do I play with my friend in my singleplayer world easily on Minecraft PC?

My cousin and I want to play Minecraft together but I don't want to join a multiplayer server or use mods. How can we do this?


How to create people picker using jquery

How to create people picker in sandbox solutions using jquery?  I need design part also. Any idea?


Proving that in a simple graph with $n$ vertices, two vertices have the same degree

I want to prove this claim using contradiction:     Let $G$ be a simple graph with $n$ vertices. Prove by contradiction that $G$ has two vertices having the same degree (Consider the vertex of smallest degree and vertex of largest degree).    I think I know where to start. The vertex of the largest degree is $n-1$ in this graph and the smallest is 1. How can I use contradiction to prove the statement above? I studied the proof of this using pigeonhole but I wanna use contradiction this time.


Accessing outer function parameters in nested functions giving weird behavior?

I have the following piece of code, it works and gives the correct output:  def msg_before(msg=None):     def actual_decorator(func):         def wrapper(*args, **kwargs):             print(msg if msg is not None else "was none")  # original             result = func(*args, **kwargs)             return result         return wrapper     return actual_decorator   @msg_before("this comes before") def test_func():     print("test")   if __name__ == "__main__":     test_func()      output:  this comes before test       But when I change the wrapper function like this:  def msg_before(msg=None):     def actual_decorator(func):         def wrapper(*args, **kwargs):             msg = msg if msg is not None else "was none"  # changed             print(msg)                                    # changed             result = func(*args, **kwargs)             return result         return wrapper     return actual_decorator   I get the following error:   Traceback (most recent call last):   File "C:/Users/ruohola/Desktop/test.py", line 33, in <module>     test_func()   File "C:/Users/ruohola/Desktop/test.py", line 19, in wrapper     msg = msg if msg is not None else "was none"  # changed UnboundLocalError: local variable 'msg' referenced before assignment       To me both of the codes seem identical, and I just don't understand where the error comes from and why it doesn't occur in the first code?


How can an Indian national get a Jamaica tourist visa?

I'm from India.I want to travel Jamaica.  Can anybody tell me all the formalities?


What job can help bridge me over to graphic design while I study?

I would like to have some kind of creative job role while I teach myself graphic design.   I currently work in a factory on an assembly line that has nothing to do with what I'm studying. So I've recently sent off my CV asking for printing jobs as print design is something I like to study the most but unfortunately no jobs are available.   Does anyone have any ideas of other jobs roles I could look for that would be a good bridge over to graphic design?    Many Thanks


Proving that product of two Cauchy sequences is Cauchy

Given that $x_n$ and $y_n$ are Cauchy sequences in $\mathbb{R} $, prove that $x_n y_n$ is Cauchy without the use of the Cauchy theorem stating that Cauchy $\Rightarrow$ convergence.  Attempt: Without that condition on not been able to use the theorem, the question becomes trivial.  Instead:  For all $\epsilon > 0$ there exists an $N \in \mathbb{N}$ such that for $n,m \geq N, -\frac{\epsilon}{2} \leq x_n - x_m \leq \frac{\epsilon}{2}$ and similar statment for $y_n$. Multiply the above by $y_n$ and the equivalent statement for $y_n$ by $x_m$.  Then add these together.  The result is: $$|x_ny_n - x_my_m| < \frac{\epsilon}{2}(x_m + y_n)$$  I have proved in a previous question that $x_n + y_n$ is Cauchy so could I apply that here and say for $n,m \geq N$, $x_n + y_n$ is Cauchy and hence convergent so tends to a finite limit for $n,m \geq N$.  This would mean my upper bound is a multiple of $\epsilon$ and since $\epsilon$ is arbritarily small, so is this upper bound. Hence Cauchy.  I don't think this would warrant a full proof in any case since by multiplying by $x_m$ and $y_n$, I am assuming they are positive so as to not reverse the inequality signs.  Nonetheless, I would appreciate some feedback on what I have done.   Many thanks


How do I solve mathematical expressions in a file from the terminal?

I have created a file that contains arithmetic expressions, one per line. How can I evaluate the expressions and display the results, from the command line?  The file looks like this:  1 + 2 6 * 4 97 % 12 43215 / 43 * 100   The goal is to output each result, in order, also one per line. I recall there is a way to do this that only requires one command, and that command used might start with w, but I can't remember how.


Does electron orbital theory contradict the Heisenberg uncertainty principle?

The quantum-mechanical model of atoms was derived from Heisenberg's uncertainty principle, which states that the position and momentum of a particle cannot both be determined to an arbitrary degree of accuracy. In order to understand the distribution of electrons in an atom, the momentum of an electron in the uncertainty principle is converted into its energy. The principle becomes "we cannot determine both the position of an electron and its energy to an arbitrary degree of accuracy". The idea that electrons exist in orbitals comes from the solving of the Schrödinger equation, which yields the principle quantum number, the angular momentum quantum number, the magnetic quantum number, and the spin quantum number. For each atom, a combination of the first three Schrödinger parameters specifies a unique electron orbital. It is noticeable that the Schrödinger equation simplifies the uncertainty principle to the extent that we are only uncertain about the position of an electron, but not its energy anymore. Each electron orbital represents a probability distribution map of electrons that fall under it. Theoretically, we can find an electron that falls under a given orbital at any position within the probability distribution map that it specifies. But the problem is, each orbital has a fixed energy value. No matter where in the orbital we find the electron, its energy does not vary. In other words, when we look at an atom and want to determine the position and energy of one of its electrons, we assign it to an orbital. The contradiction is that as soon as the electron is assigned an orbital, we fix its energy, and the only indeterminate variable is its position. So, does electron orbital theory contradict the uncertainty principle, where there are two indeterminate variables? A very concise version of my question: the Heisenberg uncertainty principle implies that we cannot simultaneously determine the position and energy of an electron. But if we divide the outer space of an atom into electron orbitals, like the electron orbital theory does, and assign each electron to an orbital, we wind up being able to determine the energy of each electron!


Will I have to go through Customs at Heathrow?

I will be flying Virgin Atlantic from Boston and then connecting with British Airways to Barcelona.  I don't know if I'll be able to bypass customs and rechecking my bag? I have given myself enough time just in case.  Any help will be great.


Column sorting on lightning:datatable only sorting one way?

I'm trying to implement the sorting functionality on a lightning:datatable. Sorting works one way (descending, clicking the column header again and nothing happens). I have followed the documentation and here's my code below:  <aura:attribute name="selectedAccountId" type="Id" access="public" /> <aura:attribute name="accounts" type="Object"/> <aura:attribute name="mycolumns" type="List"/> <aura:handler name="init" value="{! this }" action="{! c.doInit }"/>  <aura:registerEvent name="AccountFilterChange" type="c:AccountFilterChange" />   <lightning:datatable aura:id="lightningTable"                      data="{! v.accounts }"                      columns="{! v.mycolumns }"                      keyField="Id"                      onrowaction="{! c.handleRowAction }"                      onsort="{!c.updateColumnSorting}"                      hideCheckboxColumn="true" />   Controller:  doInit: function(component, event, helper) {    helper.callServer(component, "c.getAccounts", function(response) {        component.set("v.accounts", response);        })     component.set('v.mycolumns', [         {type: "button", typeAttributes: {             label: '',             iconName: 'utility:add',             name: 'selectRecord',             title: 'selectRecord',             disabled: false,             value: 'edit',             variant: {fieldName: 'variantValue'},         }},         {label: 'Name', fieldName: 'Name', type: 'text', sortable: true},             ]);         },  handleRowAction: function(component, event, helper) {     var account = event.getParam("row")     var action = event.getParam("action");     if (action.name == "selectRecord") {         var event = component.getEvent("AccountFilterChange");          event.setParams({             accountId: account.Id,         });     }  event.fire();  helper.addRow(component, account); },  updateColumnSorting: function(component, event, helper) {     var fieldName = event.getParam('fieldName');     var sortDirection = event.getParam('sortDirection');     // assign the latest attribute with the sorted column fieldName and sorted direction     component.set("v.sortedBy", fieldName);     component.set("v.sortedDirection", sortDirection);     helper.sortData(component, fieldName, sortDirection);     }   Helper:  sortData: function (component, fieldName, sortDirection) {      var data = component.get("v.accounts");      var reverse = sortDirection !== 'asc';      //sorts the rows based on the column header that's clicked      data.sort(this.sortBy(fieldName, reverse))      component.set("v.accounts", data);      },  sortBy: function (field, reverse, primer) {      var key = primer ? function(x) {return primer(x[field])} : function(x) {return x[field]};      //checks if the two rows should switch places      reverse = !reverse ? 1 : -1;      return function (a, b) {          return a = key(a), b = key(b), reverse * ((a > b) - (b > a));      }  }   How would I make this work so both desc/asc will work when clicking the column header?


Can Xdebug be triggered by Drush commands?

I'm running into an issue with my Features modules and installation profile when installing the site with drush si. There are a number of probably related issues in the Features issue queue, but none with good solutions. The interesting part (mentioned in some of the issues) is that it works fine when installing the site through the browser, but fails when installing with drush si.  I have an idea of what's wrong, but need to confirm it. The only way I can think of confirming it is to step through the code with a debugger (Xdebug is what I have set up). So, is it possible to trigger Xdebug from a command run with Drush? Specifically, can I get Xdebug to kick in when I run drush si?


Boots very slowly, once booted, boot.log displays the following:   lvmetad is not active yet, using direct activation during sysinit   Volume group "ubuntu-vg" not found   Cannot process volume group ubuntu-vg   /run/lvm/lvmetad.socket: connect failed: No such file or directory   WARNING: Failed to connect to lvmetad. Falling back to internal scanning.   Reading all physical volumes.  This may take a while...   Found volume group "ubuntu-vg" using metadata type lvm2   /run/lvm/lvmetad.socket: connect failed: No such file or directory   WARNING: Failed to connect to lvmetad. Falling back to internal scanning.   2 logical volume(s) in volume group "ubuntu-vg" now active   How to solve this?  Additional info from /etc/fstab:  /dev/mapper/ubuntu--vg-root /               ext4    noatime,errors=remount-ro 0       1 # /boot was on /dev/sda1 during installation UUID=2728dcfe-e621-4e18-8266-fc4f0057148f /boot           ext2    defaults        0       2 /dev/mapper/ubuntu--vg-swap_1 none            swap    sw              0       0  tmpfs      /var/log        tmpfs      defaults,noatime        0    0 tmpfs      /tmp          tmpfs      defaults,noatime,mode=1777    0    0


Trying to prove (A ∩ B) − C = (A − C) ∩ (B − C)

Trying to prove $(A ∩ B) − C=(A − C) ∩ (B − C)$ Im stuck here on this problem:  $(A∩B)−C=\{x | x ∈ (A ∩ B)∧ x ∉ C\}$  $(A∩B)−C=\{x|(x ∈ A ∧ x ∈ B) ∧ x ∉ C\}$  $(A∩B)−C=\{x|(x ∈ A ∧ x ∉ C) \lor (x ∈ B ∧ x ∉ C)\}$  I'm stuck right about here because how do I change the or (v) sign to the intersection sign (∩).  Please don't link me to the other question like this, I had a typo in it.


Why did Nazgul spare the other hobbits at Weathertop?

In the fight at the Weathertop, the Nazgul injured Frodo and left. They waited for him to pass to the shadow and become a wraith, but they did not kill the other hobbits on Weathertop, Sam, Merry, and Pippin. Moreover, Merry had an enchanted sword which he later used to harm the Witch King during the Battle of the Pelennor Fields. Apparently, the Nazgul did not recognize such a powerful sword.  This negligence allowed Pippin and Merry to get the Ents to march against Isengard and reduce the pressure on the Rohan. By not killing Samwise Gamgee, the Nazgul made it possible for Sam to carry Frodo to Mount Doom. As a result, the outcome of the War of the Ring is affected directly.  While book answers are preferred,  are also welcomed.


Is this good to avoid injection requests

I have to get IP and URL in request parameter and I need to avoid injection specially from url string, here is my code:  if(filterValidIp($ip) && filterValidUrl($url)) {     //it's ok      //code.... }   function for url:  function filterValidUrl($s) {     $s = trim($s);     $valid = filter_var($s, FILTER_VALIDATE_URL);     if(!$valid === false) {         return true;     }     return false; }   url:  ?url=http://google.com?id=ss'+&ip=127.0.0.1   pass as valid


Help understanding manipulation of series

Apologies if this is answered somewhere else.  I am trying to understand how the author manipulated this series to get the general form. Can anyone show me the steps and provide the rules used?  $$S_n = \sum_{i=2}^n\frac{1}{i^2 - 1} = \frac{3}{4} - \frac{1}{2n} - \frac{1}{2(n + 1)}$$  Thank you!


System and compressed memory and system interrupts takes 40% of the cpu

I searched a lot about this online and couldn't find a solution, I turned off fast startup as many answers have suggested. But it didn't work ,  The problem happened after I connected a secondary hard drive to my laptop removing the dvd drive , whenever I remove the secondary hard drive , above processes act normal. I have a SSD as my primary drive , the problem happens only when the secondary drive is connected , I desperately need a solution since this is killing my computer.


Are there nouns that are always plural — have no plural counterpart?

Are there words that have no plural counterpart, because they are, in fact plural? Words like rice or scissors come to mind.


How to store image in SQL Server database tables column

I Have a table named FEMALE in my database. It has ID as Primary Key, it has an Image column.  My Question is how do I store an image using a SQL Query?


Can we calculate the standard error of prediction just based on simple linear regression output?

The standard error of prediction in simple linear regression is $\hat\sigma\sqrt{1/n+(x_j-\bar{x})^2/\Sigma{(x_i-\bar{x})^2}}$.  My question is to calculate the standard error of prediction for $pop=1029$ just based on the following regression output. I can get all except $\bar{x}$. And I also know how to calculate the approximate standard error of prediction based on the standard errors of intercept and coefficient of $pop$, ignoring their correlation.


Is there a way to resurrect yourself with the Glyph of Warding spell?

While looking at the glyph of warding spell, I noticed that the trigger of the glyph  does not really have boundaries. The spell only states "The most typical" triggers with a few examples.  So I am wondering if you make a glyph of warding on the ground with a revivify spell stored in it and set the trigger for someone to die in range, is it possible to revive yourself this way?  And for the specific situation I want to use it for. Can you put the glyph under your bed for if you are being assassinated while you sleep?


#include <stdio.h>   union test {     int test1;     int test2;     int test3;   };   int testC(union test *x, int q, int w, int e) {     (x->test3)=q;         x--;     (x->test2)=w;         x--;     (x->test1)=e;         x--;     return 0;   };   int main() {     union test hi;     testC(&hi,5,6,7);     printf("%i, %i, %i \n", hi.test1, hi.test2, hi.test3);         int x,*y = 0;         x = 1;         x++;         scanf("%i\n", y);   }   The above code is supposed to create an Union and then "initialize" all its components to the inputs, but instead it just initializes itself to the first one. I've tried x++ and moving the values around, but nothing seems to work.


I need to print some SMS messages for a legal action. What tool does Apple provide to print SMS messages with their time stamps and other metadata?  This is similar to , but I don't need to transfer them to a different email account.  I don't want a third party tool or jail broken the device. A third party tool or jail broken device might not produce material that satisfies the  or  rules. If the evidence produced does not satisfy the rules, then it will likely waste time and money in the action.  Does Apple make such a tool for their devices?


Auto Increment Primary Key is being increased in EF when an exception occurs

I'm working with Entity Framework 6 (Code First) and I have for example something like this:      public class User     {         public int Id { get; set; }          [Required]         public string Name { get; set; }          [Required]         [EmailAddress]         [MaxLength(60)]         [Index(IsUnique = true)]         public string Email { get; set; }     }    As you can see I have a unique field called "Email". Let´s create a User:  {     "Name" : "Mario",     "Email" : "test@test.com" }   The Id is an auto-increment field. Now I create a new user with the same E-mail (this shows an exception because the "Email" field is defined as Unique):  {     "Name" : "Juan",     "Email" : "test@test.com" }   The problem is that if I want to insert now a new user, lets say:  {     "Name" : "Raúl",     "Email" : "othermail@test.com" }   This is correctly inserted into the database BUT the Id is 3, not 2. Why the exceptions are increasing the Id field? How can I stop this?


Trying to run sudo apt update and I'm receiving errors

I left the state for a couple weeks, leaving my computer on at home with my home network and router configured so that I could ssh in whenever necessary. It worked fine, I used it remotely constantly. One day though, I go to run sudo apt update  and instead of the usual update running, I get this   Welcome to Ubuntu 16.04.3 LTS (GNU/Linux 4.10.0-30-generic x86_64)  * Documentation:  https://help.ubuntu.com * Management:     https://landscape.canonical.com * Support:        https://ubuntu.com/advantage  0 packages can be updated. 0 updates are security updates.  Last login: Wed Aug  9 09:27:54 2017 from 24.3.15.124 sinux@*******:~$ sudo apt update [sudo] password for sinux: Get:1 http://archive.canonical.com/ubuntu xenial InRelease [2,004 B] Get:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease [2,004 B] Get:3 http://security.ubuntu.com/ubuntu xenial-security InRelease [2,004 B] Hit:1 http://archive.canonical.com/ubuntu xenial InRelease Hit:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease Hit:3 http://security.ubuntu.com/ubuntu xenial-security InRelease Ign:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease Ign:3 http://security.ubuntu.com/ubuntu xenial-security InRelease Get:4 http://security.ubuntu.com/ubuntu xenial-security Release [2,004 B] Get:5 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [2,004 B] Get:6 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [2,004  B] Get:7 http://us.archive.ubuntu.com/ubuntu xenial Release [2,004 B] Err:5 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease   Clearsigned file isn't valid, got 'NOSPLIT' (does the network require  authentication?) Err:6 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease   Clearsigned file isn't valid, got 'NOSPLIT' (does the network require  authentication?) Get:8 http://security.ubuntu.com/ubuntu xenial-security Release.gpg [2,004  B] Get:9 http://us.archive.ubuntu.com/ubuntu xenial Release.gpg [2,004 B] Err:8 http://security.ubuntu.com/ubuntu xenial-security Release.gpg   The following signatures were invalid: NODATA 1  NODATA 2 Err:9 http://us.archive.ubuntu.com/ubuntu xenial Release.gpg   The following signatures were invalid: NODATA 1  NODATA 2 Reading package lists... Done E: GPG error: http://security.ubuntu.com/ubuntu xenial-security Release: The  following signatures were invalid: NODATA 1  NODATA 2 E: GPG error: http://us.archive.ubuntu.com/ubuntu xenial Release: The  following signatures were invalid: NODATA 1  NODATA 2   Can any body help me figure this out? I have tried this several times in a row. What could have happened to cause this?  EDIT  Perfectly good explanation in answer


Why didn't the wildlings from GoT simply use boats to cross southward?

It seems rather silly to go through the whole effort of climbing a 700ft wall when they could simply use boats to go around it. I mean really, even Jon Snow did that when he came to try and rescue some of the wildlings before the got attacked. Are you telling me they couldn't figure out how to build rafts?


Online resources for learning/practicing bridge

Are there any good online resources to learn the game. By learn, I mean learn attain the knowledge that one would by buying/reading a good book.   For example, are there any "puzzles" that are well explained that either explain different bidding systems or strategies for playing with the dummy etc.


Prove that random variable is Poisson Distributed.

Assume in a certain year the number of credit obligors of a bank who are at risk of default is Poisson distributed with intensity $\lambda = 10$. Each individual obligor may actually default in that year with probability $p = 0.2$. Assume mutual independence  of the obligors. Let $X$ be the number of obligors that default in that year. Show that $X$ is Poisson distributed and determine its intensity.   I denote $N$ the number of obligors at risk.  And by using the identity  $$P(X = k) = \sum_E P(X = k\mid N = n)P(N = n)$$ to find the pmf I think I am supposed to arrive at the Poisson distribution.  $P(N=n)$ is already Poisson. I am having trouble figuring out the $P(X = k\mid N = n)$ and coming up with the probabilities of the pmf which need to be summed up to yield the final Poisson.


How did the transdimensional Edo god (Edo lord) come to be the overseer of the Edo?

I guess it's sort of like the way that Q had a vested interest in humanity in general---and Picard's Enterprise in particular. Q wasn't really an overseer, though. He visited the Enterprise mainly to screw around with people and play games. The Edo god clearly desired the Edo as its own---it called one Edo "my child," and so on ("Justice").  Is there anything anywhere which tells us how or why this bizarre relationship started?


How can I hide the /node page in Drupal 8?   This site:  describes the reasons for hiding it and the process for Drupal 6 and 7, though no information for Drupal 8 now  has been removed.


Show that if X is a continuous r.v. and it takes only positive values then $E(X) =\int_{0}^{∞}Z P[X ≥ t] dt $

Show that if X is a continuous r.v. and it takes only positive values then: $$E(X) =\int_{0}^{∞}   P[X ≥ t] dt$$  I am not really sure how to begin this proof. Any help or insight would be appreciated.


how to compare numbers in string with string?

i have array which is:  String[] array= {azem, 1 , soaib, 3}; // a[0]= azem , a[1]= 1, a[2]=soaib, a[3]= 3   My code is not printing any thing. I also saw ascii table and get the values of numbers in string that is from 48 to 57  but no printing.   Mycode:   String input = "1"; // integers as input  //String takeinput; // String input = "48" + takeinput; for(int i=0; i<array.length; i++){     if(array[i]== input){        System.out.print(array[i-1]);        System.out.print(array[i]);     }


Using Bash to display a progress indicator

Using a bash only script, how can you provide a bash progress indicator? For example, when I run a command from bash - while that command is executing - let the user know that something is still happening.


We all know that electrostatic PE between 2 point charges is kq1×q2/r.But what is PE between a hollow uniformly charged sphere of radius R and charge Q ??


Why is the plural form of "house" not "hice"?

The plural of mouse is mice, and the plural of louse is lice. Why is the plural form of house not hice?   According to , the word house is already longer in the language, just as mouse and louse, so it is not because it is a foreign word (loanword).   This question was marked to be a duplicate of  and , but it is actually a duplicate of neither since they handle different words, and also different causes.


How does quantum dynamics explain interference of two light beams

I am a new learner of quantum dynamics. I am puzzled about this. As quantum mechanics implies that photon can only interfere with itself, so what did photons from one light beam do to photons from another to cause the interference? (Photons from different light beams are in the same state and can not be distinguished when interference happens?)


Show that    $$1^{p-1} + 2^{p-1} +\ldots + (p-1)^{p-1} \equiv -1 \mod p$$   So, I use Fermat's little theorem, that is if $p$ does not divide $a$, then $a^{p-1}$ is congruent to $1$ (mod $p$). But I'm still confused. If $1^{p-1}$ is congruent to $1$ (mod $p$), $2^{p-1}$ is congruent to $1$ (mod $p$), and $p$ does not divide $p-1$, so $(p-1)^{p-1}$ is congruent to $1$ (mod $p$). How does that equal $-1$ (mod $p$)?


How can I change camera image details (metadata)?

I want to make my photo editing like a snapshot of my smartphone's camera, but when I check it can't.  When I edit it in Photoshop, the image details become Photoshop, so how can I set it so that the details become the camera of my smartphone?


Dual-boot (Windows/Mac OS X) MacBook Pro HDD replaced with SSD; can no longer boot in Windows on now-external USB HDD

I recently replaced the HDD on my 17-inch MacBook Pro (Early 2011) with a SSD. I did a clean install of macOS Sierra on the SSD and had no intention of copying the old HDD to the new SSD. I put the old HDD in a USB enclosure.  The HDD was partitioned and bootable in Windows 7 before it was removed from the machine. Now, however, if I plug the HDD in via USB and boot the machine holding the ALT key, the HDD is shown as a boot option, but the Windows partition is not.  Is it possible to boot in Windows from that partition any longer?  I tried booting using the HDD and then choosing Windows from the Startup Disk preferences menu, but when it attempted to boot that way, I got a black screen with a "No bootable device -- insert boot disk and press any key" message.  Any ideas?


How to install mpeg4 and h264 in ubuntu offline?

I am not connected with the internet .  So I need to download mpeg4 plugin and h264 plugin for playing videos . Please comment a line for downloading? I am new to ubuntu


Can my server handle 12,000 database requests per-minute?

First of all, Apologies if this is a silly question. I've never really had to manage servers and databases, on a "large-scale", that is.   ANYWAY, on to the question. I am trying to figure out if our current server can handle 12,000 database requests per minute. (once again, I don't know if this a lot. I assume it's mid-range). I am estimating that 2/3 of the 12,000 requests will be simple SELECT queries from super small tables. No more than 20,000 rows in a table-  I've made a point to prune them on a regular basis. LAMP Stack.  Below are the server hardware and software specs:  Processors- Intel Haswell 2095.050 MHz  Memory -  7.45gb useable   Storage - 80GB SSD  OS- Ubuntu, CentOS 7  DB  MySQL  V5.7.25  PHP - 7.2.7  The database is stored on the same server as where files are being served.  If this server is capable of this, how much further can the server be pushed?   Thank you in advance (And sorry if this seems to be a dumb question)


How can I make text appear correctly in an equation?

The basic outline of the equation below is correct but how can I make the text appear correctly right now it appears scrunched up?  \documentclass{report} \begin{document} \begin{align*}  \left.  k_S  = \left\lbrace \begin{array}{l} k_{LW}    \text{if} k_{ICOMP}<k_{LW} \\ k_{ICOMP} \text {otherwise} \end{array} \right. \end{align*} \end{document}


Parametric Equation of a Circle Using a Line

Consider the unit circle  $$ x^2+y^2=1. $$  How can I parametrize it using the line $y=m(x+1)$, where $m$ is its slope?


Studying for a preliminary exam, I came across the following question:     Let $D = \{z \in \Bbb C : \text{Re}( z )> 0\}$ and $f : D \to D $ be a holomorphic function. Prove that $$|f'(z)|\leq\frac{\text{Re}(f(z))}{\text{Re}(z)}\quad \text{for all }z\in D.$$   I thought the best way might be to use the fact that harmonic functions satisfy the maximum modulus principle, too, along with the limit definition of the derivative, but I wasn't able to get it worked out. How should I approach this problem?


What's a word for being disappointed in a surprising manner?

I know the question a bit vague but that's the only plausible inquiry I could come up with. I wanted to what word can be used if someone is disappointed and they are surprised as to the fact that to start with they never thought the subject matter or the person which disappointed them would have such an effect on them.


Indefinite integral involving normal cdf

In , the following integral identity is used, where $\Phi(t)$ is the cdf of the standard normal variable.  $$\int_{-\infty}^{\infty}t\frac d{dt}\Phi(t)^2dt=1/\sqrt{\pi}.$$  I tried to simplify to understand how. \begin{align*} \int_{-\infty}^{\infty}t\frac d{dt}\Phi(t)^2dt=\int_{-\infty}^{\infty}2t\Phi(t)\phi(t)dt=\int_{-\infty}^{\infty}2t\Phi(t)d\Phi(t)=\int_0^12x\Phi^{-1}(x)dx \end{align*}  How do I proceed to get the answer? Is there a simpler way?


What does "it" refer to in, "Strange as it may seem..."?

I have a sentence below and some say it means "the Sahara" but I doubt it as it doesn't make sense if it does. Does anyone have any idea about it?      Strange as it may seem, the Sahara was once an expanse of grassland    supported the kind of animal life associated with the African plains.


Could you win a bounty you offered on a question?

I have asked a question and I have no accepted answer apart from mine.  Is it possible for the owner of the question to win the bounty?  The bad thing is that I have given it to another answer by mistake.  Can anyone help me?


Where does dig additional section nameserver information come from?

I have a client whose website has intermittent issues, which I believe are due to DNS lookup.  When this happens and they do a ping, the host cannot be resolved.  Therefore, I ran:  dig @a.gtld-servers.net autoquarterly.com   I get:  ;; ADDITIONAL SECTION: ns1.hostlatch.com.  172800  IN  A   109.73.173.210 ns2.hostlatch.com.  172800  IN  A   109.73.173.211   but these are not the correct IP addresses.  If I do nslookup on the two nameservers, I get the correct IP addresses.  My question is where are these incorrect nameserver IP addresses coming from?  I was under the impression these were glue records which are registered with the domain registrar.  However, I noticed every domain I look up has the nameserver IP addresses in the ADDITIONAL section even though only domains which use a subdomain of their own domain name for their nameservers need glue records.


I tried the mist effect and the smoke simulation but didn't like the results. What I want to achieve is a static fog like the fog in this picture.   Steady but also moving slowly on the surface of lake.


Why don't we feel the subtle speed change of Earth's elliptical orbit?

Earth's orbit is a slight ellipse, so to conserve momentum its speed increases when it is closest to the Sun. If the speed changes there is an acceleration. If there is an acceleration there is a force. Even if the change is small and gradual, wouldn't we experience a force because the Earth is so massive?


Build Boost with C++11 support for selected libraries

I'm trying to build boost (1.65) on linux with C++11 support to link with my other project (also compiled with C++11 support).  However, I get this kind of error (which seems to happen because my boost is not compiled with c++11):  undefined reference to `boost::filesystem::detail::current_path(boost::system::error_code*)' data_parser.cc:(.text+0xf15): undefined reference to `boost::filesystem::absolute(boost::filesystem::path const&, boost::filesystem::path const&)' data_parser.cc:(.text+0x142e): undefined reference to `boost::filesystem::detail::status(boost::filesystem::path const&, boost::system::error_code*)' data_parser.cc:(.text+0x1790): undefined reference to `boost::filesystem::detail::status(boost::filesystem::path const&, boost::system::error_code*)'   Here is my command line:  ./b2 --prefix=boost-install --with-filesystem --with-system --with-program_options --with-thread link=static variant=release cxxflags='-std=c++11' install   But I noticed during compilation if I compile without any --with- (so with all libraries), I can see this line:  - C++11 mutex              : yes   and some other lines related to c++11, however as soon as I add a --with- (e.g. --with-thread), all lines relative to c++11 disappear.  I also tried to add #define BOOST_NO_CXX11_SCOPED_ENUMS around #include <boost/filesystem.hpp> but it doesn't change anything.  I have no clue what is going on here, if someone can help me.  Thank you.  Update: Here is the command of the linking command:  /usr/bin/c++   -std=c++11 -O3 -DNDEBUG   CMakeFiles/MyProject.dir/MyProject.cc.o  -o MyProject  -L/home/whiteshadow/code/MyProject-build/deps/boost-install/lib  -L/home/whiteshadow/code/MyProject-build/deps/zlib-install/lib  -L/home/whiteshadow/code/MyProject-build/deps/nifticlib-install/lib -Wl,-rpath,/home/whiteshadow/code/MyProject-build/deps/boost-install/lib:/home/whiteshadow/code/MyProject-build/deps/zlib-install/lib:/home/whiteshadow/code/MyProject-build/deps/nifticlib-install/lib: -rdynamic ../deps/zlib-install/lib/libz.a ../deps/nifticlib-install/lib/libznz.a ../deps/nifticlib-install/lib/libnifticdf.a ../deps/nifticlib-install/lib/libniftiio.a -lboost_filesystem -lboost_system -lboost_thread -lboost_program_options DataStructure/libDataStructure.a FileHandler/libFileHandler.a Parser/libParser.a Tools/libTools.a -lpthread FileHandler/libFileHandler.a FileHandler/libFileHandler.a Tools/libTools.a DataStructure/libDataStructure.a    I don't think it comes from a mis-linking issue, because if I remove -lboost_filesystem I have much more linking errors. Here I only have 7, related to only 3 functions (boost::filesystem::detail::status, boost::filesystem::detail::current_path and boost::filesystem::absolute).  Also, in libboost_filesystem.a, I'm able to find symbols for these 3 functions:  (boost::filesystem::detail::status)  00000000000026d0 T _ZN5boost10filesystem6detail6statusERKNS0_4pathEPNS_6system10error_codeE   (boost::filesystem::detail::current_path)  0000000000000c90 T _ZN5boost10filesystem6detail12current_pathEPNS_6system10error_codeE   (boost::filesystem::absolute)  0000000000001100 T _ZN5boost10filesystem8absoluteERKNS0_4pathES3_


`open` command to open a file in an application

Why can't I run this command in my terminal:  open index.html   Wasn't it supposed open this file on my browser? Also can't I run this command: open index.html -a "Sublime Text". The result of these commands are:  $ open index.html Couldn't get a file descriptor referring to the console  $ open index.html -a "Sublime Text" -  open: invalid option -- 'a'  Usage: open [OPTIONS] -- command


Prove that the sequence $a_{n+1} =\frac{1}{2}\left(a_{n}+\frac{c}{a_{n}}\right)$ is convergent and find its limit

Let $c>0$, $a_{1} = 1$, and $$a_{n+1} =\frac{1}{2}\left(a_{n}+\frac{c}{a_{n}}\right)$$  I need to:   Show that $a_{n}$ is defined for every $n\geq 1$ Show that this sequence is convergent. Find its limit.   I proved the first part by showing by induction that this sequence is positive for every $n$. To show that this sequence is convergent I'm thinking of showing that this sequence is a Cauchy series, yet can't figure out how.  For the third part I'm clueless at the moment.


Can an array be the first argument to a function?

I have a function that one of the arguments is an string that has space separated words. E.g. "foo bar ccc" I think this kind of string can be treated as an "array" and loop over each word. My question is if I need to pass this as an argument to a function can it be the first argument or will it create issues? I tried it as a first argument and it works but I am not sure if there are any pitfalls I need to watch out


How to detect idle input in C# console application?

For the sake of learning I'm writing some codes in C# to create an FTP client without GUI. For the connection I'm using the "FluentFTP" module from below link:  I'm wondering how to detect idle user and disconnect them from the server. Should I use Async or Parallel programming? I'm knew to both of them, please refer me to some simple tutorial if that is the solution.  I can provide codes, but won't for now to keep it clean. My app tries to read IP, username, and password of the FTP server and connects to it, then does some regular stuff like upload and download files. Timeout can happen during data entry or at the page user decides what task wants to do, but shouldn't happen when files are being transmitted!


Regarding travelers who have over stayed their visa expiration--

I recently visited Cape Town, SA. and during my stay I pushed my departure date back and eventually overstayed my visa allowance. I have been declared undesirable in South Africa on my American passport for 5 years.   My question is, I am also a German citizen and I have a German passport. Would border patrol overlook my entering the country with this passport, and would a notice of my declared undesirability be seen?   Is it possible for border patrol to cross-reference my dual citizenship passports?


How do I flag/report problematic content on a user's profile page?

Suppose a user has no bad posts, perhaps no posts at all, but their user page consists solely to promote a product or is otherwise problematic.  How would I flag or report this user page?  This situation is not covered by , where the accepted answer recommends to flag the user's content and not the user; in some cases the user has no content.  And I do want to flag content, just the content happens to be on the user page.


Why route air gaps for voltage isolation on PCBs?

Learning about PCB design for power supplies, I frequently see boards with routed gaps to separate low and high voltage sections of the layout.  Why go to the trouble of routing an air gap when etching the copper away should create the same level of isolation? Is the breakdown voltage of air much higher than FR4?  I assume that such gaps are used to avoid situations where copper may not be etched away perfectly.


I've added a sphere into my project and it moves with the other object in my project!    How can I stop this? Now and in the future, as I'm relatively new to Blender.


Why should the primes used in RSA be distinct?

The two primes $p$ and $q$ part of the public key need to be distinct. What's the reason for them to be distinct? Is it because factorization of $p^2$ where $p$ is a prime is relatively easier, or is there some other reason?


Are there any plans to make private Stack Exchange sites for university courses?

The current software that is in use by more and more universities for the purpose of questions & answers in courses is Piazza. Unfortunately, this software has a broken search capability, and is otherwise clunky (such as not allowing multiple student answers).  I think the Stack Exchange system could work very well for courses, and I wonder if the company has any plans to move into the area of education.


I wonder why I cannot charge a capacitor with alternating current?

Why can't I charge the capacitor with AC? How do the plates block the flow of electrons with DC but not with AC.  Somebody told me that the DC is blocked by the capacitor, so the capacitor gets charge, but I could not get the actual concept about it.


Negative energy levels in the diagram for a hydrogen atom

The higher the number of the shell (n), the higher is the energy level of the electron. However, why was it necessary to have negative values. So for example, when $n=1$, the energy could be $5 eV$ and for $n=2$, $6 eV$... having positive values could also have supported the idea that as $n$ increases, energy of electron increases. What is the point of having negative numbers, does it somehow aid calculations?


I have been successfully using xcolor and its \cellcolor command for a while, and produced beautiful results with it. However, I would like to create some more advanced background effects: color the cell with two colors:    The example above is produced using , but this approach falls apart for a number of reasons:    Tikz's matrix command is not nearly as powerful as ordinary tabulars with the array package and others. I have some numeric data that I am happily aligning on the decimal point using dcolumn - I have no idea how I would do this is in a tikz matrix. I would like to emulate booktabs behaviour, but I just can't get it working.  suggests a workaround, but it doesn't work. The coloring falls apart if the width of the columns is not predefined:   and it all falls apart.  I have had a look through other questions;  and  manage to create one-colored bars dynamically;  combines tabularx and tikz in a promising approach, but I did not manage to adapt this to my purpose;  draws lines and manages to stick to a tabular environment - maybe a good starting point?   So ideally I would like to stick to a tabular environment, and be able to specify the cells' background content freely (for the point of this question I would be happy with a solution that gives me the diagonally separated effect as in the top left corner of the two examples), with a command such as \twocolor{blue}{purple}.


Undeleting a question can also undelete blacklisted tags

The  and .  When the question was deleted, we hadn't yet blacklisted .  Once the question was undeleted, the system recreated it.  It probably shouldn't do that.  Probably related:


Is it possible to run APK's on 17.10? I saw the other posts but they were no where near helpful! I don't know what that Twerk application was but the link did not work. Is there anyway to use an android application on ubuntu 17.10? things like bluestacks and whatnot do not work on wine, and all the android emulators like ANbox don't work in 17.10 gnome, wayland or Xorg.


Why does gravity decrease as we go down into the Earth?

We all know that gravity decreases as the distance between the two increases. Hence  $$ F = G \frac{Mm}{r^2}. $$  Hence the acceleration due to gravity  $$ g =\frac{F}{m}= G \frac{M}{r^2} $$   increases as $r$ decreases. Then why does it decrease as we go deep into the earth?


Travelling to India from Chicago via Paris (Charles de Gaulle Airport). I have a valid US visa, and Indian Passport(valid & expired).  Do I really need transit visa?  Looked up online and found this, ""   Foreigners who DO NOT NEED an Airport Transit French Visa, regardless their nationality are the following cases:  holders of the valid US visa.


SharePoint Designer - Hiding fields in a form unless specific condition is met

I'm trying to create a form in SharePoint Designer 2013, I want to be able to hide a specific field in the form unless the answer to another field has been changed to a specific option. Here is my code:
              External Sales?:     	              <SharePoint:FormField runat="server" id="ff438747{$Pos}" ControlMode="New" FieldName="External_x0020_Sales_x003f_" __designer:bind="{ddwrt:DataBind('i',concat('ff438747',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@External_x0020_Sales_x003f_')}" />         <SharePoint:FieldDescription runat="server" id="ff219374description219373{$Pos}" FieldName="External_x0020_Sales_x003f_" ControlMode="Edit" />
 <xsl:if test="@External_x0020_Sales_x003f_ = 'Yes'">
              PPE:     	              <SharePoint:FormField runat="server" id="ff438748{$Pos}" ControlMode="New" FieldName="PPE" __designer:bind="{ddwrt:DataBind('i',concat('ff438748',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@PPE')}" />         <SharePoint:FieldDescription runat="server" id="ff219375description219373{$Pos}" FieldName="PPE" ControlMode="Edit" />
 </xsl:if>   As you can see, I want to be able to make it so when "External Sales?" = Yes, then it shows the field "PPE".  Any help on this matter would be greatly appreciated.


Can anyone explain the difference between observed variables and unobserved variables (preferably in plain English ) ?


Need to hide element only if it's already showing

I'm working on a website and I have created a dropdown menu. The menu opens when you click an "About Me" link, which reveals a few more links (biography, interests, etc.). I'm able to toggle the menu on and off by clicking on the "About Me" link. Here's my question: I want to write some code such that the dropdown menu can only be opened by clicking the "About Me" link, but can be closed by clicking the link or ANYWHERE ELSE on the document (it's kind of annoying to have to click the "About Me" link again in order to close the dropdown). Here's the jQuery code I have so far:   $(".about-me").click(function() {     $(".dropdown-menu").toggle(); });   I tried adding a   $(document).click(function() {     $(".dropdown-menu").hide(); });   but since the "About Me" link is a part of the document as well, this makes it so that clicking the link will never open the dropdown menu in the first place. Any help is much appreciated!


I would like to know if there is a table where accesses to tables are saved, per user or per system.  I'm using both SQL Server 2005 and 2008.


I have used try - except and it works, but I was wondering if we can perform a similar function with for - if and else.  # check for "NA" values, ignore the entries which have them     # index: DeptTime = 4,Deptdelay = 15, Arrtime = 6, ArrDelay = 14     for index in flight_data[1:]:         try:             x_dept.append(int(index[4]))             y_dept.append(int(index[15]))             x_arr.append(int(index[6]))             y_arr.append(int(index[14]))          except ValueError:             pass   For instance, can we do something like this to get the exactly same answer?   # check for "NA" values, ignore the entries which have them         # index: DeptTime = 4,Deptdelay = 15, Arrtime = 6, ArrDelay = 14         for index in flight_data[1:]:             if index[4] =='NA' or index[15] == 'NA' or index[14] =='NA' or index[6] == 'NA':              pass              else:                 x_dept.append(int(index[4]))                 y_dept.append(int(index[15]))                 x_arr.append(int(index[6]))                 y_arr.append(int(index[14]))


TikZ: Draw angle with label between lines

How do I draw an angle with a label between two lines when the lines are not necessarily drawn in the same \draw call?  I need to draw an angle with a label, theta, between the y-axis and the pendulum string (see picture below).  Other suggestions/improvements of my code/diagram are welcome.  Current code:  \documentclass[tikz,border=10pt]{standalone} \usetikzlibrary{calc,patterns} \begin{document} \begin{tikzpicture} \coordinate (origo) at (0,0); \coordinate (pivot) at (1,5);  % draw axes \fill[black] (origo) circle (0.05); \draw[thick,gray,->] (origo) -- ++(4,0) node[black,right] {$x$}; \draw[thick,gray,->] (origo) -- ++(0,-4) node[black,below] {$y$};  % draw roof \fill[pattern = north east lines] ($ (origo) + (-1,0) $) rectangle ($ (origo) + (1,0.5) $); \draw[thick] ($ (origo) + (-1,0) $) -- ($ (origo) + (1,0) $);  \draw[thick] (origo) -- ++(300:3) coordinate (bob); \fill (bob) circle (0.2); \end{tikzpicture} \end{document}   Current output:    For illustration, I want something like this in my diagram:


How to edit location of each vertex in uv map and it's related vertex in 3d view?

I'm new to blender scripting so don't judge me If my question is stupid. I'm trying to make a script for blender 2.79 or 2.83 doesn't matter. The whole idea that I want to make a script for is that I want to have access to all uv vertices and their related vertex in the 3d view. To be exact, I want to get and set the location of each uv vertex and it's 3d view vertex. How can I get access to it and How can I set them to a different value? Thank you in advance!


Contraction mapping in the context of $f(x_n)=x_{n+1}$.

I'm interested in convergence of $f(x_n)=x_{n+1}$ and often hear this term referenced.  What does it mean to be a contraction mapping in the context of the sequence of real numbers given by $f(x_n)=x_{n+1}$? And what does it tell us about such sequence?  A search online gives the answer given by Wikipedia, that it is a function $f$ defined on a metric space $(M,d)$ from $M$ to itself with the property that for some real number $k \in [0,1)$,  $$d(f(x),f(y)) \leq k d(x,y)$$  This definition is quite unhelpful because I barely know what a metric space is. I feel like this definition is to generalized, and I'm interested in in the specific case of recursively defined real sequences $f(x_n)=x_{n+1}$ that there should be a more specific answer to my question.


Difference between >&/dev/null and &>/dev/null

I tried to find information about the operator order in the statement >&/dev/null  Is there any difference between >& and &>?


Detecting outliers in time-series if I don't have a "normal" dataset

I have been trying to detect anomalies in my time-series dataset. What I am trying to accomplish is the following: I have a multivariate dataset, where two columns are of special interest. One tells us the maximum power that should have generated and the other column tells us the actual power generated. What I am trying to do is label a datapoint as "fault" or "fault-free". I am trying to do it through a difference between theoretical maximum and the real power generated. Plotting difference demonstrates that distribution is skewed (see picture).   Most of the methods I have read about, including PCA/Mahal. distance/Neural Nets ask for normal (or fault-free) training dataset, which I cannot provide with certainty. I have also tried control charts but that didn't work.  Are there any methods that you can recommend?  Thank you


How to find files between two dates using "find"?

I have an email account that has passed 60GB of emails, and currently I'm having a lot of trouble using an email client to archive emails of last year (2011).  Via terminal, I am trying to use  to locate the files between 2011-01-01 and 2011-12-31, but no avail.  How can I find files between two dates?  If relevant, the end goal will be a batch that will move each file found, matching the date interval, to a folder.


Examples of PCA where PCs with low variance are "useful"

Normally in principal component analysis (PCA) the first few PCs are used and the low variance PCs are dropped, as they do not explain much of the variation in the data.  However, are there examples where the low variation PCs are useful (i.e. have use in the context of the data, have an intuitive explanation, etc.) and should not be thrown away?


Why are diacritics used in words that apparently don't need them? Is it some sort of poetic license?

In his poem  Gerard Manley Hopkins uses diacritics where one would normally not see them. Does anyone know why?  Here is the poem:     Márgarét, áre you gríeving   Over Goldengrove unleaving?   Leáves   like the things of man, you   With your fresh thoughts care for you,   can you?   Ah! ás the heart grows older   It will come to such   sights colder   By and by, nor spare a sigh   Though worlds of   wanwood leafmeal lie;   And yet you wíll weep and know why.   Now no   matter, child, the name:   Sórrow’s spríngs áre the same.   Nor   mouth had, no nor mind, expressed   What heart heard of, ghost   guessed:   It ís the blight man was born for,   It is Margaret you   mourn for.   Notice, for example, how he wrote "is" in the last line, compared to the one on the line before. Is it some kind of poetic license? Is it to indicate what syllables should be stressed?


I was wondering how can I shift my data that fall between a range lets say [0, 125] to another range like [-128, 128].  Thanks for any help


Will a format/OS reinstall remove viruses?

I have had a couple of run-ins with viruses and malware before, and have found that a format and re-install of the OS is the easiest way of dealing with them.  But, my experience has simply been: PC acting funny > Run scan(s) to find virus/malware > Format & Reinstall > PC no longer running funny; scans don't find anything.  A lot of other guides suggest altering the registry, and deleting any specific .dll files and uninstalling any programs that relate to the virus. But that approach seems to be a more intricate/delicate approach than my "wipe it all and start over" tack.  So, will my approach actually remove a virus/malware? If you need specifics - Conficker and Trojans are the ones I have used this on.


Why moving template method with rvalue reference parameter gives unresolved external symbol error?

This is a simple class to illustrate the problem:  class ClassA { public:     template<typename T>     void Method1(T&& a) {}; };   Then in my main:      double a = 0;      ClassA classA;     classA.Method1(a);   This compiles fine. But when I move the Method1 implementation to a cpp file, like so...  Header:  class ClassA { public:     template<typename T>     void Method1(T&& a); };   Implementation:  template<typename T> void ClassA::Method1(T&& a) {}  template void ClassA::Method1<double>(double&&);   I receive the error message in Visual Studio 2013     error LNK2019: unresolved external symbol "public: void __thiscall ClassA::Method1(double &)" (??$Method1@AAN@ClassA@@QAEXAAN@Z) referenced in function _wmain   Now if in the main I replace the call to Method1 to  classA.Method1(std::move(a))  it compiles fine. Why does the header only version compiles fine without the std::move whereas the version with the implementation requires a std::move to compile?


My knowledge of constructing bijections is very poor and I would really appreciate any clarification or assistance.  The question I am having trouble with is the following:   Let $S$ be an arbitrary set.  Let $F=\{\{0,1\} \xrightarrow{f} S \}$ be the set of functions from $\{0,1\}$ to $S$.  Construct a bijection $F \xrightarrow{\alpha} S \times S$.


13 equal charges, q , are placed at the corners of a 13 sided regular polygon. What is the force on a test charge Q at the centre?   I couldn't figure out from where to start solving it. It would be very messy to do vector addition of 13 forces. So I think, there must be some trick behind it? Can you please help me?


Installing Java 7 Update 25 on 12.04 LTS?

How can I install Java on Ubuntu 12.04?  I have:    Java(TM) SE Runtime Environment (build 1.7.0_21-b11) Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)


Why this strange code compiles and returns 1?

Why this code compiles and returns 1?  int main(int ac, char* av[]) {     return ac[av] == 0; }


Remove Unity And Replace With Something Different

I need to "Safely" remove Unity 12.04 and replace it with something Different. I have looked and I have tried a couple of things (one which caused a complete re-install of Ubuntu). So maybe someone else can help.  I am a Tinkerer! I Love Customization! I get bored and have to constantly change things, and Unity just won't give me that FREEDOM!! Don't get me wrong, I love Unity for something else, and there are a lot of great things about it. But it is just NOT for me...  Any suggestions would be greatly appreciated...  What I am looking for:   "SAFE REMOVAL", of Unity, and install of "Something New"... As much customization as possible... Bells and Whistles!    Please Help!...


Is there a way we can clear all cached items without using the admin page or using Drush?  If we know where the cache is stored can we clear them manually?


Converting Shapefile to GeoJSON. Both OGR and Mapshaper converters give errors

I'm trying to convert a large Shapefile (120 MB) to GeoJSON.  OGR converter gives an error that says process time took over 15 seconds, so process was cancelled.  Mapshaper gives the following error: File size of .shp doesn't match size in header  What can I do now?  I'd prefer not installing any desktop software to do a simple conversion.


Let $X_\alpha$ be connected CW-complexes. Then from Hatcher's book,  $$\pi_{n}(\prod_{\alpha} X_{\alpha})=\prod_{\alpha}\pi_{n}(X_{\alpha}).$$  Is it true in general that  $$\pi_{n}(\bigvee_{\alpha} X_{\alpha})=\prod_{\alpha}\pi_{n}(X_{\alpha})?$$


What are the drawbacks with using UUID or GUID as a primary key?

I would like to build a distributed system. I need to store data in databases and it would be helpful to use an  or a  as a primary key on some tables. I assume it's a drawbacks with this design since the UUID/GUID is quite large and they are almost random. The alternative is to use an auto-incremented INT or LONG.  What are the drawbacks with using UUID or GUID as a primary key for my tables?  I will probably use Derby/JavaDB (on the clients) and PostgreSQL (on the server) as DBMS.


What will be the formula for the following:  $$\int_0^\infty \cos(x)dx.$$


Should I declare a variable inside or outside the main function?

In C++, it is advisable to declare global variables inside the main program, or outside it, before everything else? I mean, what is the difference between  #include <iostream>  int variable;  int main() {    //my program      return 0; }   and  #include <iostream>  int main() {      int variable;      //my program      return 0; }   In which case should I use which one?


How can I show coordinates by grid in TikZ automatically?

I have the following TikZ code which draws a grid and shows the coordinates.  To display the coordinates I am using the loop foreach.  \documentclass[12pt]{article} \usepackage{tikz}  \begin{document} \begin{tikzpicture} \draw[help lines,step=.2] (-2,-2) grid (7,4); \draw[help lines,line width=.6pt,step=1] (-2,-2) grid (7,4); \foreach \x in {-2,-1,0,1,2,3,4,5,6,7}  \node[anchor=north] at (\x,-2) {\x}; \foreach \y in {-2,-1,0,1,2,3,4}  \node[anchor=east] at (-2,\y) {\y}; \end{tikzpicture} \end{document}   Is there a way do simplify the code in this way that I have a key like show coordinates (maybe step coordinates/.initial=step ):  \draw[help lines,step=.2,show coordinates=true] (-2,-2) grid (7,4);   Or a modification of the command grid like  \draw[help lines,step=.5] (-2,-2) gridwithcoordinates (7,4);     By using pstricks it is very simple with the command \psgrid  \documentclass[12pt]{article} \usepackage{pstricks}  \begin{document} \begin{pspicture}(-2,-2)(7,4) \psgrid \end{pspicture} \end{document}   Bonus: How can I set a larger line width for the help lines at the integer coordinates (see picture above)?  (I don't know the correct words ;-) )


Traveling from Phoenix, AZ to Mexicali to Guadalajara

My bf and I are traveling for a wedding in Oct. We planned on driving from phoenix to mexicali and flying from there to Guadalajara.   My questions are: can we use our drivers license to get into Mexicali or should we get the passport card? Trying to avoid getting the book it is expensive for us.   Also, once in Mexicali, do we NEED the passport card to fly to Guadalajara or can we just use our ID and the tourist card? We will be there about 4 days.


What is the literary device where a word holds two meanings in a phrase?

For example,  He showed the strength of his arms and his heart when he pushed the fallen horse out of the mud slide.


I have a Textbox.Text which content is 1+1. How to I convert this into double and store it in i?

I have i = double.Parse(TextBox.Text); but when I enter the + symbol, this error appear "System.FormatException: 'Input string was not in a correct format.'"


How can I lockdown a computer so the user cannot minimize or move the browser window?

I am trying to setup a computer with a browser page. The webpage allows people to enter their email address and submit a form.   However, it is intended to be a kiosk. I don't want people to be able to minimize or move or drag around or visit any other URL.   How can I lock things down? Can I configure local security policy somehow? I am planning on using a Windows XP, or Windows 7.  Thank you,


I saw a video In which the girl says I think I can smell the spiritual  As far as I know articles can not be used with adjectives . No?


Example of compact riemannian manifolds with seccional curvature negative

I need a example of a riemannian compact manifold with seccional curvature negative. The idea is take hyperbolic space and a suitable group that acts proper, free and discontinuously and with quotient compact. But i don't know very much  about groups acting in hyperbolic space.  Thanks in advance.


wireless network adapter supported on ubuntu?

I would like to know if my  is in anyway compatible with Ubuntu.  Dual booting Ubuntu 15.04 with windows 8.1 on an HP Pavilion G6 1d98dx.  I've tried so many different distros but the problem is the same on all of them "wireless disabled by hardware switch" I've tried rfkill unblock all but that did not fix the problem.  Bus 002 Device 002: ID 04f2:b293 Chicony Electronics Co., Ltd  Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 05dc:a20b Lexar Media, Inc.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub 00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h Processor Root Complex 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] BeaverCreek [Radeon HD 6520G] 00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] BeaverCreek HDMI Audio [Radeon HD 6500D and 6400G-6600G series] 00:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 12h Processor Root Port 00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [IDE mode] 00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11) 00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11) 00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11) 00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11) 00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 13) 00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01) 00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11) 00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] FCH PCI Bridge (rev 40) 00:15.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Hudson PCI to PCI bridge (PCIE port 0) 00:15.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Hudson PCI to PCI bridge (PCIE port 1) 00:15.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Hudson PCI to PCI bridge (PCIE port 2) 00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 0 (rev 43) 00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 1 00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 2 00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 3 00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 4 00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 6 00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 5 00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 7 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 05) 07:00.0 Network controller: Ralink corp. RT5390 Wireless 802.11n 1T/1R PCIe 08:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader (rev 01)


Python understanding list comprehension from Java background

I come from a Java background and just started to work on Python. Most of the things are fairly easy to pick up but I am having hard time to understand one thing in the language which I just found out that is called list comprehension. What is this list comprehension in Python? How does this compare with language constructs found in Java? The problem is it's everywhere, nearly all the examples I found here and there use it.  For the following example, allow me to understand how this works.  [x**2 for x in range(10)]   And then there this.  [j + k for j in 'abc' for k in 'def']   Beyond that I also have seen things like this somewhere on Stackoverflow.  (x for x in (0,1,2,3,4))   Also things like this.  total = sum(x+y for x in (0,1,2,3) for y in (0,1,2,3) if x < y)   This started to get messy, could you please help me?


how to protect udp packets from packets loss?


Chrome: middle mouse button overriden on certain web pages?

Normally when I click on a link in Chrome with a middle mouse button, the page open s in a new tab. I find it useful and would like it to always work that way.  But on some sites, specifically SharePoint sites I'm often working with, middle click on certain links opens the page in the same tab. Example can be found on this publicly available  when clicking on "Internet Sites" or "SharePoint resources" links with middle mouse button.    Those menu items seem like a link (they definitely have URL assigned). Why do them open in the same tab instead of a new one, when middle clicked? Can this behavior be changed in Chrome's settings or using some addon?


When can I apply "their" to a singular noun?

At what times can I use plural "their" applying it to a singular noun? For example, I can say:  Every student has his own learning curve and his own natural disposition.  Can I also say  Every student has their own learning curve and their own natural disposition.  ? And if not, can you, please, explain the reason?


Properties possessed by $H , G/H$ but not G

i) Does there exist a group $G$ with a normal subgroup $H$ such that $H , G/H$ are abelian but $G$ is not ?   ii) Does there exist a group $G$ with a normal subgroup $H$ such that $H , G/H$ are cyclic but $G$ is not ?


$\sum a_i \ln(b_i) \leq \sum a_i \ln(a_i)$ with $\sum a_i = \sum b_i = 1$

Okay, this is my another try on the question  which I unfortunately mis-stated and actually asked for a problem different than the one I have to solve. I wish to show that given the constraints $0 < a_i, b_j < 1$ and $\sum_{i=1}^{n} a_i = \sum_{i=1}^{n} b_i = 1$ we have the following inequality: $$\sum a_i \ln(b_i) \leq \sum a_i \ln(a_i)$$ The problem arose when I was trying to compute some topological pressures and $a_i, b_j$ are actually measures of some sets, but this inequality (if, hopefully, true) is purely algebraic. Can anyone provide some suggestions?


Finding the State Space Model of a linearized Equation of satellite

I have been trying for days to find how to convert the linearized Equation of a satellite given by the equation attached in the image to STATE SPACE equation.   Please I have been struggling for days. I am a newbie in control system.   Please do help out.  $$ \ddot\varepsilon+D\,\dot\varepsilon+K\,\varepsilon=B\,u \tag{1} $$  Where  $$ \varepsilon= \begin{pmatrix} r \\ \theta-\omega\,t \end{pmatrix} =  \begin{pmatrix} \text{radial-deviation-from-R} \\ \text{angular-position} \end{pmatrix} $$ $$ u= \begin{pmatrix} u_1 \\ u_2 \end{pmatrix} = \begin{pmatrix} \text{radial-thrust} \\  \text{tangential-thrust} \end{pmatrix} $$ $$ D= \begin{pmatrix} 2\omega\over\ R & 0 \\ 0 & 0 \end{pmatrix} $$ $$ K= \begin{pmatrix} -2\omega^2 & 0 \\ 0 & 0 \end{pmatrix} $$ $$ B= \begin{pmatrix} 1\over m & 0 \\ 0 & 1\over m \end{pmatrix} $$  Want to convert above equation $(1)$ to state space equation of the form  $$ \dot x = A\,x+B\,u $$  Also if $y=\dot\theta$ is observed at the output what will be the transfer function?


Which website to ask question and get suggestions related to programming language (i.e. Laravel) ? )

I want some programming suggestion, say for example, in , I have a question about whether we should or must remove public folder or not for best practices. Shall we remove it or not whether I am on local server and go on to upload on live server.   I am afraid to ask this question on  as I can end up losing my reputation which I do not want as I do not have much.  So where can I ask those need suggestion kind of programming questions? Here on Meta or somewhere else?


How to network two Ubuntu computers using ethernet (without a router)?

How can I network two Ubuntu computers, so that they can "see" each other at an IP address?


Source compiled OpenSSL throws error "libssl.so.1.1: cannot open shared object file" but it libssl.so.1.1 exists in ../lib?

You can see below that when I attempt to invoke openssl without sudo on a source install (), the command fails, but with sudo prefix it does not fail. When I try to check dependencies with ldd, I cannot get any meaningful info. What do I do to correct this?  Log:   toszter@odroid:/usr/local/openssl/bin$ sudo /usr/local/openssl/bin/openssl  /usr/local/openssl/bin/openssl: error while loading shared libraries: libssl.so.1.1: cannot open shared object file: No such file or directory toszter@odroid:/usr/local/openssl/bin$ which openssl  /usr/local/openssl/bin/openssl toszter@odroid:/usr/local/openssl/bin$ sudo openssl  OpenSSL> ^C toszter@odroid:/usr/local/openssl/bin$ ldd openssl      libssl.so.1.1 => not found     libcrypto.so.1.1 => not found     libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb6f47000)     libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb6e5b000)     /lib/ld-linux-armhf.so.3 (0xb6f83000) toszter@odroid:/usr/local/openssl/bin$ sudo ldd openssl      libssl.so.1.1 => not found     libcrypto.so.1.1 => not found     libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb6f10000)     libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb6e24000)     /lib/ld-linux-armhf.so.3 (0xb6f4c000)    And before it is suggested, yes I saw . Not a solution AFAIK.


where are my downloaded google play apps? i cannot find them in apps on my surface

I have downloaded several apps from google play on my surface but they are no where to be found. I have tried search and poked around download files but nothing. Should it really be this hard? Seems ridiculous.


system is in superuser mode how it change to normal mode

how to get superuser mode to normal mode. When i install my system with ubuntu 16.04.3 it is in superuser mode ican't install new softwares how it overcome i try to install from software center and terminal when i open my software center like this,    i try to install from terminal   sudo apt-get install synaptic  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?


Show that $\int_0^\infty \!\frac{e^{-x}-e^{-xt}}{x}\,\mathrm{d}x=\log(t)$

I have tried a lot of different integration methods and I can't solve it.   $$\int_0^\infty\! \frac{e^{-x}-e^{-xt}}{x}\,\mathrm{d}x=\log(t)$$


Meaning of "phase delay" in forced oscillations

I'm currently reading about forced oscillations, and in the book (A course in Classical Physics by Alessandro Bettini) I'm using, they start with the equation  $$\frac{d^2x}{dt^2} + \gamma\frac{dx}{dt} + \omega_0^2 x = \frac{F_0}{m} \cos{\omega t} \, .$$  They then solve for the stationary solution $$x_s(t)=B\cos{(\omega t-\delta)} \, ,$$  where  $$\delta = \arctan \left( \frac{\gamma \omega}{\omega _0^2 - \omega^2} \right)$$  is said to be the "phase delay of the displacement $x$ relative to the instantaneous phase of the force". However, I'm afraid I'm having trouble understanding what this statement means. What exactly do they mean by "phase delay" and how does this term actually relate to the displacement and the driving force?


What is the easiest way of taking Kirlian pictures (photographic techniques used to capture the phenomenon of electrical coronal discharges)?     Kirlian photography, although the study of which can be traced back to   the late 1700s, was officially invented in 1939 by Semyon Davidovitch   Kirlian.  The Kirlian photographic process reveals visible “auras”   around the objects photographed.  These photographs have been the   subject of much myth and controversy over the years.   For clarification, I'm not concerned whether this is a digital or analog solution.


Why do I get "Metadata kept in Windows cache, refused to mount" when I try to mount my NTFS drive?

I have trouble with mounting my hard disk:  Error mounting /dev/sda5 at /media/quetzalcroix/DataSave: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda5" "/media/quetzalcroix/DataSave"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   I forgot to restart my windows 8 before I'm installing Ubuntu and format my C:\ drive. Is there any other options that I could do to mount this? Or I should backup my entire volume to other media and then I format my hard drive?


Finding symmetry from conserved quantity (reversed Noether's theorem)

Is Noether's theorem reversible? For example, given some conserved quantity, can you find the underlying symmetry which leads to the conserved quantity?


There is an appropriate time standard for the display of a splash screen for mobile apps or not?

Or it's depends on each case? I tested here with 2 second and found it very long. But a coworker told me that 2 second is the default. Is it true?


How can I obtain the "Perfect as Tears" and "Like Stars in the Sky" achievements?

These two achievements require crafting a Radiant Star gem of the four original types: topaz, ruby, emerald, and amethyst.  Finding the recipes is no longer an issue because in the 2.0.1 patch, all gem recipes through Marquise were automatically trained (or gained on jeweler levels - mine started at 10 so I can't check).  So, prior to the expansion, one could farm hundreds of Flawless Square gems at level 60 and slowly work their way up to a Radiant Star.  Unfortunately, once you hit level 61, Flawless Squares no longer drop.  Only Marquise and Imperial gems do.  Given the very small window where Flawless Square gems are eligible to drop, the high number of gems required, and the low amount of experience required to get out of this range, is there any reasonable method for acquiring these two achievements in RoS?


I'm working on a synth and I have some code that's going slower than I'd like.  I've narrowed down the culprit to some nested for loops which iterate over a 3 dimensional vector of floats.  Given that this part of my code is the current bottle neck, I'd like to optimize it as best as I can.  My current understanding of 2d C arrays is that they are really just one long linearly-nested array with some fancy syntax.  int* myArray[3][3]; pseudoSetEntriesToRowNum(myArray); for (int i = 0; i < 9; i++) {   cout << myArray[i]; } // output: 000111222   As for vectors, (when 1D) the performance seems to be widely sufficient () with issues arising more from resizing than accessing/setting.  But when 2d, my understanding would suggest that the linearly-nested optimization is lost, and that for each dimension a pointer is being followed.  vector<vector<int>> myVector = pseudoMake2dVectorWithRowNumAsEntries(3, 3); int* myArray = &(myVector[0][0]); for (int i = 0; i < 9; i++) {   cout << myArray[i];  // this should not be okay } // (my guess of) output: 0,0,0, BAD_ACCESS * 6   My question on this topic is first, am I even thinking about this correctly?  And, if I am, would the implication be that 2D+ dimensional vectors are not good for time sensitive operations?  And if 2D+ dimensional vectors are not ideal, what are some good alternatives?


Two-finger scrolling not working since ubuntu 17.10+

I recently upgraded to ubuntu 17.10 and since then I cannot do two finger scrolling, only edge scrolling. Any suggestions how to make the two finger scrolling work again? I use a Lenovo ThinkPad 450s    Output of xinput list-props $(xinput list | perl -ne '/touchpad.*\bid=(\d*)/i && print $1') as requested by @Hi-Angel  Device 'SynPS/2 Synaptics TouchPad': Device Enabled (141):   1 Coordinate Transformation Matrix (143): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000 libinput Tapping Enabled (276): 1 libinput Tapping Enabled Default (277): 0 libinput Tapping Drag Enabled (278):    1 libinput Tapping Drag Enabled Default (279):    1 libinput Tapping Drag Lock Enabled (280):   0 libinput Tapping Drag Lock Enabled Default (281):   0 libinput Tapping Button Mapping Enabled (282):  1, 0 libinput Tapping Button Mapping Default (283):  1, 0 libinput Accel Speed (284): 0.600000 libinput Accel Speed Default (285): 0.000000 libinput Natural Scrolling Enabled (286):   1 libinput Natural Scrolling Enabled Default (287):   0 libinput Send Events Modes Available (261): 1, 1 libinput Send Events Mode Enabled (262):    0, 0 libinput Send Events Mode Enabled Default (263):    0, 0 libinput Left Handed Enabled (288): 0 libinput Left Handed Enabled Default (289): 0 libinput Scroll Methods Available (290):    1, 1, 0 libinput Scroll Method Enabled (291):   0, 1, 0 libinput Scroll Method Enabled Default (292):   1, 0, 0 libinput Click Methods Available (293): 1, 1 libinput Click Method Enabled (294):    1, 0 libinput Click Method Enabled Default (295):    1, 0 libinput Middle Emulation Enabled (296):    0 libinput Middle Emulation Enabled Default (297):    0 libinput Disable While Typing Enabled (298):    1 libinput Disable While Typing Enabled Default (299):    1 Device Node (264):  "/dev/input/event5" Device Product ID (265):    2, 7 libinput Drag Lock Buttons (300):   <no items> libinput Horizontal Scroll Enabled (301):   1


I have a class like   public class KeyNamePair {  public string Key {get;set;}   public string Name{get;set;} }   My code  List<KeyNamePair> list =new List<KeyNamePair>();      list.Add("1", "Day 1");     list.Add("2", "Day 11");     list.Add("4", "Day 5");     list.Add("6", "Day 13");   How can i sort the list to display  >  "Day1", "Day5", "Day 11", "Day 13"   in order?  i tried   var SortedList = source.OrderBy(x => x.Name).ToList();             return SortedList;   this does not do any sort


number of ways, n can be written as a product of k integers

For $k\ge2$, let $d_k(n)$ denote the number of ways of writing $n$ as a product of $k$ positive integers (so that $d_2(n) = d(n)$ where $d(n)$ counts the number of positive integral divisors of $n$). Then prove that as $x\rightarrow \infty$, $$\sum_{n\le x}d_k(n)=\frac{x(x\log x)^{k-1}}{(k-1)!}+O(x(\log x)^{k-2})$$ this is a question from our lecture notes, here's my attempt: I tried induction on $k$. I proved it for $k=2$. Assuming it is true for $k=m$ and proving for $k=m+1$, using abel's partial summation formula for a positive divisor $a$ of $n$ $$\sum_{n\le x}d_k(n)=\sum_{n\le x}\sum_{a|n}d_{k-1}(a)=\sum_{a,b; ab\le n}d_{k-1}(a)$$ $$\sum_{a\le x}[\frac xa]d_{k-1}(a)$$ where square brackets mean greatest integer function. writing $[p]=p-\{p\}$, fractional part gives the Big-Oh part of the expression on the right hand side. Multiplying $\frac xa$ with $d_{k-1}(a)$ and using induction hypothesis to replace $d_{k-1}$ by the formula above, gives $$\sum_{a\le x}\frac{xd_{k-1}(a)}{a}=\frac{x^2{(\log x)}^{k-2}}{(k-2)!}\sum_{a\le x}{\frac 1a}$$ we earlier have proved that as $x\rightarrow \infty$, $$\sum_{a \le x}\frac 1a=\log x + O(1)$$ I know this is to be done using Abel's partial summation formula but can't think of what $a_n$ to use and what $f(x)$ to use to proceed any further. I feel like we need to use $f(x)=x^2$ so that when we differentiate it, we get the $x$ form again but in order to make the fraction of log and factorial into $A(n)=\sum_{n\le x}a(n)$, what should the $a(n)$s be? PS. even tho I need to find a way of doing this using Abel's formula, it would be great to see other methods too so please share if you have one.