I'm having trouble figuring out what I'm doing wrong.  If i use this set of code I get the result I intend:  $x =  $db->prepare('SELECT * FROM table LIMIT 2'); $x->execute(); print_r($x->fetchALL());   When I use this set of code I don't get anything in return:  $a = "table"; $b = "2"; $x =  $db->prepare('SELECT * FROM ? LIMIT ?'); $x->execute(array($a,$b)); print_r($x->fetchALL());   Is there something I'm missing?  Thanks in advance.


Installing Ubuntu Server 18.04 on old PC "no bootable device"

I'm trying to install Ubuntu Server 18.04 on a PC with an old Intel motherboard. The installation finished ok, but at restart it says  no bootable device   I suppose that Ubuntu was installed in UEFI mode and the motherboard only boots in legacy mode.  What should I do?


Both the fundamental constants $\hbar$ and $c$ have dimensions. In particular, $[\hbar]=ML^2T^{-1}$ and $[c]=LT^{-1}$. But in natural units, we make them dimensionless constants of equal magnitude. How is this possible? This means length is measured in the same units as time which is measured in the units of inverse mass! Am I measuring the distance between two points in seconds??? Can we do that?  I cannot make myself comfortable with it :-( Also why is it not possible to make $\hbar=c=G=1$ simultaneously?


Does British English use a dash in between third-party, or is that for American English?


For which $n\geq2$ does there exist $\sigma \in A_n$ with $|\sigma|>n$?  I have found this same question , But I have not been able to understand how it works. On my own I came to the conclusion that for $n$ less than $8$ the result is not satisfied, but for $n = 8$, I found the permutation $\sigma$ formed by a $5$-cycle and a $3$-cycle. Which is in $A_n$ and $|\sigma|=15>8$. In particular, I cannot understand how the proof follows, to conclude that the result is true for all $n\geq 8$. Could you help me? If there is an easier way to see this, please, I would appreciate if you shared it.


How do I use Cayley's Theorem to find a subgroup that is Isomorphic to a Group?

Let $G = \mathbb Z/2\mathbb Z × \mathbb Z/2\mathbb Z$. Use Cayley’s theorem to determine explicitly a subgroup of $S_4$ that is isomorphic to $G$.


How to access my wife's Outlook calendar

My wife and I both have Outlook 2007 and are networked in our SOHO. We nave no server. Is there a way I can access her calendar from my desktop to make appointments for her, or to check her bookings?


How do I choose between the D7200 and D610 for sports and all-round shooting?

I am having trouble deciding between the D7200 and the D610. I am upgrading from the D3200, so both camera would make a great difference.  At the moment, I have four lenses. The 70-200mm f2.8 (tamron) and 50mm f1.8G. The other two are for dx and I don't use them anymore.  Next year, I will be the photographer for sports at my local college. Which are ice hockey, football, soccer, basketball, and volleyball. I also want to shoot music shows and open a little studio to do headshots at home.   I would like to go full frame for everything other than sports, but I feel like the D7200 would be better for sports than the D610.   What do you think would be better? Could the D610 be enough for sports?  I am really having hard time choosing.  Edit: The two other lenses are: 18-55mm f3.5-5.6 and the 55-200f4-5.6 (both for DX)  Ialso do not plan on selling my D3200, I will use it as a backup/second camera


I have an array like this: const arr = [1,2,3,4,5]  I want to achieve something like this: let answer = 1,2,3,4,5  I want the typeof answer to be a number.


Evaluating the complex integral $\int_{|z|=2}^{}\frac{1}{z^2+1}dz$

I tried finding the integral of $\int_{|z|=2}^{}\frac{1}{z^2+1}dz$ but not sure whether it is correct. $\gamma(t)=2e^{it},t\in[0,2\pi]$  $$\int_{|z|=2}^{}\frac{1}{z^2+1}dz=\int_{0}^{2\pi}\frac{2ie^{it}}{4e^{2it}+1}dt$$  I cannot seem to take it forward from here. Is it possible to use Cauchy's integral formula to get an answer? Thanks


Can someone help me understand in basic terms why $$\frac{1}{\frac{1}{X}} = X$$  And my book says that "to simplify the reciprocal of a fraction, invert the fraction"...I don't get this because isn't  reciprocal by definition the invert of the fraction?


Amazing issue with a string read from a file

I want to read a string from a file which is in the asset folder. I can read wihtout problem but I have a strange problem when I try to manipulate these string.  Content of my data file  [001] [SCA]   23 [NBT]   2 [END]  public static String readLevelFromFileAsset(String filename, Context ctx, String levelID)  {     String Content = null;     try {         AssetManager am = ctx.getAssets();         InputStream is = am.open(filename);          if ( is != null )         {             InputStreamReader inputStreamReader = new InputStreamReader(is);             BufferedReader bufferedReader = new BufferedReader(inputStreamReader);             String receiveString = "";             StringBuilder stringBuilder = new StringBuilder();              while ((receiveString = bufferedReader.readLine()) != null )              {                 Log.d(TAG, receiveString + " : " + receiveString.length());                  byte[] bytes = EncodingUtils.getAsciiBytes(receiveString);                 for(int i = 0; i < bytes.length; i++)                 {                     Log.d(TAG,String.valueOf(bytes[i]));                 }                  if(receiveString == "[001]")                 {                     Log.d(TAG, "Hello");                     stringBuilder.append(receiveString);                 }             }              is.close();             Content = stringBuilder.toString();         }      }     catch (FileNotFoundException e) {         e.printStackTrace();     }     catch(IOException e){         e.printStackTrace();     }     catch(Exception e){         e.printStackTrace();     }     finally     {         Log.d(TAG, Content);     }       return Content; }   Ce content of the logs: [001] : 5 91 48 48 49 93  My question is : WHY the word 'Hello' is not written in the log ?  it seems that in the 'IF' the receivestring is unknown !


How to search for files modified after a particular time?

OS: Windows 7 64-bit  Here's a hypothetical problem: there's a folder with multiple sub-folders (which themselves may have sub-folders and so on). A program creates/modifies files in any of these folders say at time t=YYYYMMDDHHMM. Is there are simple command to search for all the files created/modified after time t?


Disk ejected but still show up in Disk Utility?

I have this external (USB) drive that can't seem to be disconnected correctly.  Whenever I eject the drive, it won't disappear from Disk Utility.  Afterwards when the drive gets re-connected again, it cannot be mounted. At this stage, I would need to reboot the Mac to get the drive to mount again.    Ejecting from the Terminal via diskutil eject /dev/disk2 returns a Disk /dev/disk2 ejected message and unmounts the disk.  However the disk still shows up both in Disk Utility and diskutil list.   Furthermore even after the USB cable is disconnected, the disk still shows in both Disk Utility lists — GUI and command line.   How can I solve this?  OS: macOS Mojave 10.14.1 (18B75)


What is the remainder when $5 000 000^{500 000 000 000}$ is divided by the prime number $10^{6}+3$?

What is the remainder when $5,000, 000^{500 ,000 ,000 ,000}$ is divided by the prime number $10^{6}+3$?  I tried to use Fermat's Little Theorem but the exponent is still pretty high.


Omitting public modifier in java methods

I am learning Java and there's something bothering me and the textbook doesn't explain it. I understand that you use modifiers to declare methods inside classes and all. But I suddenly got to a class declared like static void(){ }  Why is there no public or private modifier and it still works? Can I avoid using the public modifier everywhere else or how does that work? I understand that static means member of the class and void that it doesn't return a value. Yet why not public or private for that matter.


Let $f: (-1,1) \to R$ and $f'(0)$. Suppose that $-1 < a_n < 0 < b_n < 1$ and $a_n \to 0, b_n \to 0$ Show that $$D_n = \frac{f(b_n) - f(a_n)}{b_n - a_n}$$ goes to $f'(0)$. This is a specific case where we need to show that $f'(0)$ is the result, not a general point where the derivative is evaluated at. I'm not quite sure where to start. I'm not sure what $f'(0)$ is, all I'm told is that it exists. So I'm trying to show this quantity goes to that, when I don't even know what $f'(0)$ is equal to. That is throwing me off. I'm also not sure the relation to $f'(0)$ that $D_n$ has. Can anyone clarify the question for me and maybe get me started? Thank you!


How can I vertically align the numerators of two fractions?

I am writing the following formula:  % arara: lualatex  \documentclass{article} \usepackage{mathtools} \usepackage{unicode-math}  \begin{document} \[y_\mathup{COG}=\frac{h}{3}\frac{l_\mathup{c,a}+2l_\mathup{c,i}}{l_\mathup{c,a}+l_\mathup{c,i}}\] \end{document}   which yields:    I don't like the way, the h and l_\mathup{index} is vertically aligned. Is that typical behavior? Good style? Could I avoid that?


How does the brain know where a signal came from? What is the addressing system

I am an electronic engineer so I am thinking about this from an electronics outlook.  How does the addressing system work, As I see it, the nervous system is small parallel branches attached to larger "serial" lines (spinal cord).  The serial line is then attached to the brain, but how does it then figure out where the message came from and then get the message back to the place it came from.  If I were to build a robot I would have an addressing system with each message and maybe some kind of error checking to make sure the messages don't become corrupted, but as it's not an electronic system I don't see how the brain could possibly do this. unless it is a fully parallel system and there is a single wire going from every sensor back to the CPU..


How can i get the object of BeanFactory without using XmlBeanFactory & ClassPathXmlApplicationContext in spring?

Hello i'm new to spring framework and i have some doubts..  When i'm creating the object of BeanFactory using its implemention class XmlBeanFactory, it shows XmlBeanFactory is depricated.   BeanFactory ref = XmlBeanFactory(resource);  ApplicationContext is a sub-interface of BeanFactory and i found this solution:  BeanFactory ref =  new ClassPathXmlApplicationContext("applicationContext.xml");  Q1. Is there  any other sub class of BeanFactory except XmlBeanFactory or ClassPathXmlApplicationContext, So that we can get the object of BeanFactory? Q2. Then what is the purpose of BeanFactory if we are using its implementation interface(ApplicationContext) sub class(ClassPathXmlApplicationContext)? Q3. When should i use BeanFactory or ApplicationContext or should i never use BeanFactory?


Why does xelatex produce a different binary of the pdf each time?

This is doc.tex  \documentclass{article} \begin{document} a \end{document}   Then I xelatex doc.tex and md5 doc.pdf, so I get a unique md5  code. If I run xelatex again on the same tex file it produces a diff pdf (diff md5).  What can I do for xelatex to procude the same md5 result for the same tex file?


Draw a bivariate normal distribution in TikZ

For a small class I want to draw a bivariate normal distribution and show where the means from the two variables meet in the space. Has anyone done this in TikZ?


In the following proof that square root of 2 is non-terminating, where does the expression for q come from?

I understand the following proof but how did the author come up with the following expression? $$q = p - \frac{p^2 -2}{p + 2}$$ $q$ being defined that way is crucial for the proof but what's so special about that choice of $q%$? Why choose that?   The expression for $q^2 - 2$ follows from the first part but I don't understand how to get $q$ itself. The best I could do was realize that, for this particular case, $q = \sqrt{2} + 1$ but I can't see how that's significant and ow that could have led to the expression I'm curious about.  Also what if I need to do the same thing for an arbitrary root $\sqrt{n}$. How do I come  up with such a $q$?  P.S.: I'm talking about the second part of the proof- not where he proves that $\sqrt{2}$ is irrational but the part "... A contains no largest number and ...".


I want to know the meaning of \fi in LaTeX. I don't understand the use. And don't find an easy definition online.


I am laying my floor but I have a transition that I need help with, I am going from laminate to tile but the tile is much bigger. I have attached a drawing of the 2 different materials and I am looking to see what people might recommend on doing


I have looked everywhere for confirmation of this proof of the triangle inequality with no success.  Prove the triangle inequality:  $$\vert x + y \vert \leq \vert x \vert + \vert y \vert.$$  Proof:  Given the definition of $|x|$ to be $|x| = \max\{-x, x\}$. We know that $x \leq \vert x \vert$ and $y \leq \vert y \vert$.  So:  $$\vert x + y \vert \leq \vert \vert x \vert + \vert y \vert \vert = \vert x \vert + \vert y \vert.$$  Thus, we have proven the triangle inequality:  $$\vert x + y \vert \leq \vert x \vert + \vert y \vert.$$  What is wrong with it? If nothing is wrong with this proof, why is it not readily used as it seems to be quite concise.


Nested roots sequence, how to prove it's monotone and bounded?

Let $a\ge1$ and define the sequence $(x_n)$ recursively by: $$x_1 = \sqrt{a}$$ $$x_{n+1}= \sqrt{a+x_n}$$  Here's what I did:  Plugging in some values makes it seem as if the sequence is increasing. I first solve the equation $t=\sqrt{a+t}$, equivalently $t^2 -t -a =0$, to get an idea what's going on. The roots are $$t_{1,2}= \frac{1 \pm \sqrt{1+4a} }{2}.$$ Therefore, between the roots, that is for $$t\in \left( \frac{1 - \sqrt{1+4a} }{2}, \frac{1 + \sqrt{1+4a} }{2}\right)$$  we have $t^2-t-a \le 0 \iff t \le \sqrt{a+t}$. Here's my attempt at showing inductively that $$\forall n\in \mathbb{N}, \ x_n \le \frac{1 + \sqrt{1+4a} }{2}$$  For $n=1$, the statement is true (simple arithmetic). Suppose it's true for $n$. Consider  $$x_{n+1}= \sqrt{a+x_n}\le \sqrt{a+\frac{1 + \sqrt{1+4a} }{2}}=\frac{1 + \sqrt{1+4a} }{2},$$  because $\frac{1 + \sqrt{1+4a} }{2}$ satisfies $x=\sqrt{x+a}$.  So this establishes the sequence $(x_n)$ is bounded. Now, by induction again, I try to show it's monotonically increasing. The base case $x_1\le x_2$ is obvious. Assume (strong induction) $x_{n-1}\le x_n$ for all $n>1$. But since we have $$x_1\le x_n \le \frac{1 + \sqrt{1+4a} }{2}, $$   then $x_n$ lies in the appropriate interval, so $x_n \le \sqrt{a+x_n}=x_{n+1}.$  Is this proof correct? Can the condition on $a$ be relaxed to $a>0$? Maybe even small negative $a$? And could someone provide me with another proof of convergence of $x_n$? I absolutely hate this one!


How to use custom metadata in validation rule?

How to use a custom metadata records checkbox field in validation rule over a custom Object?  Is there any way?


Assume I have to use a Roman numeral to denote an ordinal number. Is it more correct to affix “-th” to it or not? That is, should I write “XIX century” or “XIXth century” to mean “nineteenth century”?


Meaning of a product of two physical units

I am having a hard time to understand the meaning of measurements that involve a product of physical units, like $10\, \rm  N\cdot m$ ($10$ Newton-meters), $3.33\, \rm J\cdot s$ ($3.33$ Joules-second), and so on. When I have a quocient of physical units, everything is simple: $10\, \rm m/s$ (meters per second) means that in every one second, I travel a distance of $10$ meters. $25\, \rm N/m^2$ (Newtons per square meter) means that in every square with side equal to $1\, \rm m$ in a surface, I have a force of $25\, \rm N$. But what does the product $10\, \rm m\, s$ ($10$ meters-second), $25\, \rm N\, m$ (Newton-meters) mean? I just can't figure out the meaning of this even after many online searches.


Rudin $L^p$ exercise with a sequence of norms

Let $(X,M,\mu)$ be a measure space , with $\mu (X)<\infty$, and let $f:X \to R$ be a M-measurable function such that $0<||f||_\infty <\infty$  Define $\alpha_n:= ||f||_n ^ n$  Prove that $\lim_{n\rightarrow\infty} \frac {\alpha_{n+1}}{\alpha_n }= ||f||_\infty$


Diagonal argument applied to computable numbers

Upon applying the Cantor diagonal argument to the enumerated list of all computable numbers, we produce a number not in it, but seems to be computable too, and that seems paradoxical.  For clarity, let me state the argument formally. It suffices to consider the interval [0,1] only. Consider $0 \leq a \leq 1$, and let it's decimal representation be found as $$ a =\sum_{n=1}^\infty 10^{-n} a^{(n)} $$ We say that $a$ is computable, if there is a Turing machine $T_a$ which receives $n$ and outputs $a^{(n)}$ in finite time, i.e., it always halts.  Let $A$ be the set of all computable numbers. A moment's reflection shows that $A$ is countably many. For example, we can implement $T_a$ in (say) Python, always choosing the program with the shortest string length, and we sort $T_a$ by their program according to the ASCII characters' dictionary order. If two programs, which both implement $T_a$, have the same string length, choose the one with foremost dictionary order. This gives a sorting function of $A$.  Let $A$ be enumerated with $a_1, a_2, a_3 \dotsc$. Now, construct a number $b$ so that: $$ b =\sum_{n=1}^\infty 10^{-n} b^{(n)} \\ b^{(n)} =\begin{cases} 4,\quad a_n^{(n)} =3 \\ 3,\quad \rm{otherwise} \end{cases} $$ We see $b \notin A$. Moreover, $b^{(n)}$ is obtained within finite time, since we only need to know $a_n^{(n)}$'s value. Thus $b \in A$, but $b \neq a_n$ for all $n =1,2,3, \dotsc$, a contradiction.   is related, but I don't think it's a duplicate. The post applies the diagonal argument on the reals, rather than the computable numbers.


My service is working fine for single record insert when i send bulk records at that time it showing soapenv:ClientSystem.ListException: Duplicate id in list: 01ti0000002gUP1AAM Class.Sample.behaviourOfWebService: line 235, column 1  the error line is Database.upsert(pList)     p.productCode = pCode;    p.name =pName;    pList.add(p);  }


PregMatchAll always returns 0 even while regex matching

I have been doing this:  preg_match_all('!
\s*?(.*?)\s*<\/div>!', $result, $match);   for my this block

Sex

Sex

   But my match always returns zero while doing  print_r($match[1]);   What might be the problem?


Why isn't my text file reading in Java Eclipse as a String?

I'm a beginner in Java Eclipse. I am trying to read a .txt file, and use the data as a String value. However, when I use an if statement, the condition is not registering the value as a String and is therefore not meeting any conditions and I am only getting the final else. The purpose of my code is to read in a text file and determine the required value: i.e. if the line starts with "avg" , the program must display the average of the following numbers. My .txt file contents is this: min:1,2,3,4,5,6\n max:1,2,3,4,5,6\n avg:1,2,3,4,5,6 Here is a part of my code: public static void main(String[] args) throws IOException {          //declare variables     String line, operation;     int min, max, sum, num;     double avg;     List<String> lineArray;     String outputPath = "C:\\output.txt";       //these are not the actual file paths, i just didnt      String inputPath = "C:\\input.txt";         //want to give personal information.      //try open file     try {                  //create File instance           File text = new File (inputPath);            Scanner scnr = new Scanner(text);                                         //loop until end of text file         while ( scnr.hasNextLine() ) {                                          line = scnr.nextLine();                  //read line from text file             operation = line.substring(0,3);         //get operation from String data                          line = line.substring(4);                //get String value of numbers                           lineArray = Arrays.asList(line.split(","));     //separate string into array elements              //setup initial values             sum = 0;             min = Integer.parseInt(lineArray.get(0));     //convert to Int             max = Integer.parseInt(lineArray.get(0));                          //loop through line array and determine min, sum and max of each             for (int i = 0; i < lineArray.size(); i++ ) {                                  num = Integer.parseInt(lineArray.get(i));                 sum += Integer.parseInt(lineArray.get(i));                 if (num > max)  max = num;                 if (num < max)  max = num;                              }                          avg = sum / lineArray.size();                             //the IF condition statement that is not working                             if (operation  == "min") {                 System.out.println(min);             }                          else if (operation == "max") {                 System.out.println(max);             }                          else if (operation == "avg") {                 System.out.println(avg);             }                          else System.out.println("Error");                      }   //end of while loop                  scnr.close();                                                       //close scanner              }   //end of try          catch ( FileNotFoundException e ) {     }      }   //end of "main" class  When I manually set operation as "min" or "max" or "avg" the program works as it should.


Proficiency with specific weapons vs 'simple and martial'?

In the PHB on pg. 146 it states that there are two weapon categories in which the players can be proficient: simple and martial.  As per  answer to another question, being proficient in either category makes the players character proficient in using all weapons of the respective category.   However in the race descriptions the players are given proficiency for specific weapons. Dwarfs, for example, have the trait Dwarven Combat Training giving proficiency with battleaxes, handaxes, throwing hammers and warhammers.   How do the two types of proficiencies interact with each other?


Will installing wine will allow the hackers to hack into my Ubuntu computer just like what happens in Windows?

What if I installed an .exe game with a trojan using wine on my Ubuntu? Would this allow the hackers to hack into my device just like what happens usually on Windows? What about the viruses that work behind the scenes in the background, backdoors, the trojans that store a file inside the registry, startup folder and I don't know what else -- will my Ubuntu be hacked just like what happens in Windows?   Extra question: Should I install anti-virus on my Ubuntu?


What is the use of the ideal on algebra I can't understand, can someone explain to me the general use and the idea of it. The definition of an ideal is let $R$ be a ring, a non-empty subset $I$ of $R$ is called ideal if $a-b$ belongs to $I$ and $ra$, $ar$ belongs to $I$, $r$ belongs to $R$ $a,b$ belongs to $I$.


Diophantine equation: $2 a^2 + 2 b^2 = c^2 + d^2$

I am looking for integer solutions of the following equation:  $$ 2a^{2} + 2b^{2} - c^{2} - d^{2} = 0 $$ Preferentially the solutions should obey $a+b+c+d=0$.   By inspection I found the solutions: $(a,b,c,d)=(1,0,1,1)$, and $(a,b,c,d)=(1,1,2,0)$. Additional solutions can be generated by changing the signs of $a,b,c,d$, or by scaling by an integer, or by swapping $a$ and $b$, and $c$ and $d$.  As a theoretical physicist I am rarely working with diophantine equations, and hence I am wondering what other solutions exist that I have not taken into account.


No matter where I look, I haven't seen almost any indications of which characters unlock which scenes.    Put plainly: Which character/level combinations unlock a scene?


Existence of a continuous function which does not achieve a maximum.

Suppose $X$ is a non-compact metric space. Show that there exists a continuous function $f: X \rightarrow \mathbb{R}$ such that $f$ does not achieve a maximum.   I proved this assertion as follows:  If $X$ is non-compact, there exists a sequence which has no converging subsequence. Therefore, the set $E$ of elements of this sequence is infinite and has no limit points. Therefore, in the induced topology, $E$ is a countable discrete space. Let $e_n$ be a enumeration of $E$. Define $f: E \rightarrow \mathbb{R}$ as $f(e_n)=n$. Since $E$ is discrete, $f$ is continuous. By Tietze (note that $E$ is closed in $X$), there exists a continuous function $g: X \rightarrow \mathbb{R}$ which extends $f$. But $f$ is unbounded, then so is $g$, and $g$ does not achieve a maximum. $\square$  My first question is: Is everything in the proof fine?  Now, my second question is: Can you provide me a proof which is more elementary? (Not using Tietze, for example. This exercise is just after the definition of compactness. I suppose this proof is not what was intended.)  And my third question is: Does the proposition hold for arbitrary topological spaces? If not, can you provide a counter-example?


I had a linux plain text document file with close to 100000 lines, a size of 10 Mb. I accidentally overwrote the file via python code. But I got an exception in the middle of the code and think the file socket did not get closed properly. The new file has a few new lines (250) ,BUT the size of the file corresponds to the old one. I was wondering if the old content will still be there within the file and any chances of recovering the same. I tried using TestDisk and poked around a little bit. But it did not have any option for working on a particular file or maybe I am doing it wrong. I dont have any expertise in file systems and would really appreciate any pointers on how to proceed. Thanks


Coloring the integers with red, blue, and green

Can all integers can be painted either red, blue, or green such that there exists at least $1$ integer of each color, and if any $3$ integers $a$, $b$, and $c$ have the same color then $a+b$, $a+c$, $b+c$, and $a+b+c$ also have the same colour?


"AT TIME ZONE" with zone name PostgreSQL bug?

I was answering this  question and found strange result:   select * from  pg_timezone_names where name = 'Europe/Berlin' ;      name      | abbrev | utc_offset | is_dst  ---------------+--------+------------+--------  Europe/Berlin | CET    | 01:00:00   | f   and next query  select id,    timestampwithtimezone,    timestampwithtimezone at time zone 'Europe/Berlin' as berlin,    timestampwithtimezone at time zone 'CET' as cet  from data ;  id  | timestampwithtimezone  |       berlin        |         cet           -----+------------------------+---------------------+---------------------  205 | 2012-10-28 01:30:00+02 | 2012-10-28 01:30:00 | 2012-10-28 00:30:00  204 | 2012-10-28 02:00:00+02 | 2012-10-28 02:00:00 | 2012-10-28 01:00:00  203 | 2012-10-28 02:30:00+02 | 2012-10-28 02:30:00 | 2012-10-28 01:30:00  202 | 2012-10-28 02:59:59+02 | 2012-10-28 02:59:59 | 2012-10-28 01:59:59  106 | 2012-10-28 02:00:00+01 | 2012-10-28 02:00:00 | 2012-10-28 02:00:00   I'm using PostgreSQL 9.1.2 and ubuntu 12.04. Just checked that on 8.2.11 result is the same.  According to  it doesn't matter if I use name or abbreviation.  Is this a bug? Am I doing something wrong? Can someone explain this result?    EDIT For the comment that CET is not Europe/Berlin.  I'm just selecting values from pg_timezone_names.  select * from  pg_timezone_names  where abbrev ='CEST';  name | abbrev | utc_offset | is_dst  ------+--------+------------+--------   and  select * from  pg_timezone_names  where abbrev ='CET';         name         | abbrev | utc_offset | is_dst  ---------------------+--------+------------+--------  Africa/Tunis        | CET    | 01:00:00   | f  Africa/Algiers      | CET    | 01:00:00   | f  Africa/Ceuta        | CET    | 01:00:00   | f  CET                 | CET    | 01:00:00   | f  Atlantic/Jan_Mayen  | CET    | 01:00:00   | f  Arctic/Longyearbyen | CET    | 01:00:00   | f  Poland              | CET    | 01:00:00   | f  .....   During winter Europe/Berlin is +01. During summer it is +02.  EDIT2 In 2012-10-28 timezone has change from summer time to winter time at 2:00. This two records have the same value in Europe/Berlin:  204 | 2012-10-28 02:00:00+02 | 2012-10-28 02:00:00 | 2012-10-28 01:00:00 106 | 2012-10-28 02:00:00+01 | 2012-10-28 02:00:00 | 2012-10-28 02:00:00   This suggest that if I use one of abbreviations (CET or CEST) for big data range (summer time and winter time) result will be wrong for some of records. Will be good if I use 'Europe/Berlin'.  I changed the system time to '2012-01-17' and pg_timezone_names has changed also.  select * from  pg_timezone_names  where name ='Europe/Berlin';      name      | abbrev | utc_offset | is_dst  ---------------+--------+------------+--------  Europe/Berlin | CEST   | 02:00:00   | t


Why do websites tend to show the content to the left?

I've noticed a trend in content positioning on popular websites such as facebook, youtube, 9gag and many more.. they all have their main content to the left side of website. Why is this? Or is it just random?


Why is the domestic power supply almost universally supplied at 230V?

Most domestic power in the developed world is supplied at 230V (±10V).  I presume it's a "sweet spot" for something, perhaps:   the highest voltage that won't jump certain insulators a balance of voltage vs lethal danger the highest voltage that won't fry various components   Why has that voltage been chosen just about everywhere?


Run a command before any terminal command

Is there a way to run one command before any terminal command gets executed?   For example:   > ls -ltr > "Hello you ran ls -ltr" //this is what I would like to achieve > ..output of ls -ltr will be here   Is it possible to run make sure an echo runs before any command is executed?  Thanks


Place for indie developers to promote their own software

Within the Stack Exchange ecosystem, is there a place for indie developers to post links to their software? Promote, test, discuss, and brag about it? If no, then why not?


Ability to add files to a directory but not remove existing files

Is there some permissions setup that would allow a user, say, john, to add a file to a directory d, but not be able to remove an existing file owned by another user, say, root?   My understanding is that this is not possible, since one needs execute permissions to add a file to the directory, but this also gives on the power to unlink any file in the directory.  (I'm using Mac OS 10.9, but this question presumably applies to all POSIX-ish systems.)


Sci fi movie where a killer robot wears the face of the main character

There's a movie, that I watched in the mid 90's, with a scene where a killer robot wears the face of the friend of the main character.  The scene I remember is on a planet e.g. the moon, and that the main character is in a white dome like structure hiding from the robots. The robot walks by with the friend's face on and peers through the little window on the door of the dome. The robot was a metal structure with long metal legs and only the face was human.  I thought it was Screamers, with Peter Weller, but I've just watched the whole thing and it did not happen.


Will this Garbage Disposal to P Trap height work?

Recently purchased a retrofit farm sink and went to hook the garbage disposal back up. After roughing everything back up because the farm sink sets much lower I am wondering about drainage and if this setup is acceptable. What do you think?


How do I print with the screen stylesheet?

A number of websites that I use have really bad stylesheets for the print media, but their screen stylesheets are quite good.  Is there any way to tell my browser to ignore the print stylesheet and just print with the screen stylesheet?  I’d also like to do this when I want to show clients the difference between the two.


Error occurred while trying to create a custom object using SalesForce SOAP API

HAVE A SMALL REQUIREMENT   am trying to create a custom object using salesforce rest api ..here is my code   req=new Httprequest();  req.setEndpoint('https://ap1.salesforce.com/services/Soap/u/22.0/xxxxx') string b ='      <?xml version="1.0" encoding="UTF-8"?>'+     '<CustomObject xmlns="http://soap.sforce.com/2006/04/metadata">'+         '<deploymentStatus>Deployed</deploymentStatus>'+         '<description>just a test object with one field for eclipse ide testing</description>'+         '<fields>'+             '<fullName>Comments__c</fullName>'+             '<description>add your comments about this object here</description>'+             '<inlineHelpText>This field contains comments made about this object</inlineHelpText>'+             'Comments'+             '<length>32000</length>'+             '<type>LongTextArea</type>'+             '<visibleLines>30</visibleLines>'+         '</fields>'+         'MyFirstObject'+         '<nameField>'+             'MyFirstObject Name'+             '<type>Text</type>'+         '</nameField>'+         '<pluralLabel>MyFirstObjects</pluralLabel>'+         '<sharingModel>ReadWrite</sharingModel>'+     '</CustomObject>';   req.setHeader('Authorization','OAuth '+SESSION_ID);  req.setMethod('POST'); req.setHeader('Content-Type', 'text/xml;charset=UTF-8');  req.setHeader('SOAPAction', '""');  req.setbody(b); p =new Http();  res=new Httpresponse();  res=p.send(req) ;   here is my error message   <?xml version="1.0" encoding="UTF-8"?> <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">     <soapenv:Body>         <soapenv:Fault>             <faultcode>soapenv:VersionMismatch</faultcode>             <faultstring>The SOAP request must use SOAP 1.1, did not recieve a SOAP 1.1 Envelope as the document root</faultstring>         </soapenv:Fault>     </soapenv:Body> </soapenv:Envelope>


How to make "xinput --set-prop 11 "Synaptics Finger" 10 15 100" permanent?

Title says it all, every time I shut down I have to rerun xinput --set-prop 11 "Synaptics Finger" 10 15 100 again is there any way to fix this?


Time is not properly synchronised with Ubuntu

I select the option Automatically from the Internet in Ubuntu. But the time is not the real time as it should be. I am attaching a screen shot. Could anyone give me a solution for that. Thanks in advance.


I just installed phpMyAdmin on a clean Ubuntu Server 13.04 installation. Everything in the application works, except for the "Settings" page. This one page is blank when I click on it and when I attempt to view the source code there is nothing in the source. If I cat the file I can see that the file is not empty. The error log is not helpful - nothing is logged when attempting to view the page. How can I debug or fix this?


Is there a difference between  int[] array = new int[10];   and  int array[] = new int[10];   ?  Both do work, and the result is exactly the same. Which one is quicker or better? Is there a style guide which recommends one?


How do I start my own taint infestation in Minecraft?

I've tried placing tainted blocks, fibrous taint, all of it. What do I do?


I'm trying to learn how to programming in Latex. I want to make an if-else-statement. What I will do is something like this:  \def\x{2} { \if x =2 Yes \else no \fi }   But it doesn't work exactly how I imagine it would be. Any suggestions how to fix this minimal example?


How do I cite a source from a another source?

Suppose I'm writing an article about topic X. During research I come across a related article in which the author has made statement Y and referenced publication Z. For one reason or another, I haven't read Z. Perhaps it is an expensive textbook or I'm just lazy. Can I in my article also make statement Y and reference Z, bypassing the middle author, or is that wrong?


SELECT statement with IN and input variable in SQL server

Having a table (Table1) with Columns -> Column1 int, Column2 int, Column3 varchar(128), Column4 char(11) Need to create a stored procedure to get the details from Table1 based on the input parameter. Input parameter holds values with comma-separated. It has to be mapped with Column1 Create Procedure ProcedureName(@InputParams VARCHAR(MAX)) AS BEGIN     SELECT  Column2             ,Column3              ,Column4     FROM Table1     WHERE Column1 IN (@InputParams)     ORDER BY Column2 END  The below statement is throwing conversion error  "Conversion failed when converting the varchar value '123, 456, 789' to data type int."  EXEC ProcedureName @InputParams = '123, 456, 789'  Converting the SELECT statement to the dynamic query will work fine but will we able to fix the conversion issue in the static query. Please help me.


Reduce the empty space on each side of pages

Presently, the two main content <DIV>s on a SO page, #mainbar & #sidebar, have fixed widths hard coded into the CSS.  This means that even if you make the browser very wide (say, streching over two monitors), the only parts of the page that get bigger are the empty white space on either edge.  Meanwhile, if the page contains a code sample with long lines, it will have the most heinous sin of design: horizontal scrollbars.  This is even worse when trying to print, as the #sidebar is (properly) hidden, but its space is not reclaimed -- the right margin is just bigger, all while the code sample is now printed with the scroll bars.  A trivial change to the CSS, making the width of the #mainbar DIV a high percentage instead of a fixed amount, will allow us to have useful print-outs.  UPDATE:  In response to the commentors who prefer narrow columns, my suggestion of completely compatible with that --- all you have to do is make your browser window narrower! (Windows are not required to be maximized)


How can I calculate the minimum and maximum frequency in a medium?

I know that Ultrasonic frequencies around 1 MHz cannot travel in air. Why is that? How can I calculate the range of frequencies in a medium?


Given $\lim _{n\to \infty} a_n = L$ ($L>0$), how to prove that $\lim_{n \to \infty} 1/a_n = 1/L$ without knowing the expression of $a_n$?

Given positive sequence $a_n$ where $\lim _{n\to \infty} a_n = L, L >0$, prove using the  that $$\displaystyle{\lim _{n\to \infty}}\frac{1}{a_n} = \frac{1}{L}.$$     My thoughts:  How can I do this if I don't know how $a_n$ is defined? I can use the given limit to get the range of $a_n$ in terms of $L$, but I lack the direction to complete the proof.


Pgfplots: How to fill area under a curve in a 3d plot similar to \closedcycle in 2d

How can I fill the area under a curve in a 3d plot, similar to the \closedcycle command in ordinary 2d plots? Applying this command does a filling which is not rotated.  Minimal working example:  \documentclass{article}  \usepackage{tikz} \usepackage{pgfplots} \begin{document}   \begin{tikzpicture}      \begin{axis}[     xmin=0,xmax=3,     zmin=0,zmax=2     ]         \addplot3[red,domain=0:1,fill=blue,opacity=0.5,samples y=0] (2,x,x^2) \closedcycle ;      \end{axis}   \end{tikzpicture} \end{document}   In 2D it looks like this  \documentclass{article} \usepackage{tikz} \usepackage{pgfplots} \begin{document}   \begin{tikzpicture}   \begin{axis}[domain=0:1     ]         \addplot[red,domain=0:1,fill=blue,opacity=0.5,samples y=0] {x^2} \closedcycle ;   \end{axis}   \end{tikzpicture} \end{document}   How can I easily apply this to a 3D plot?


For all $X \geq 1$,$\sum\limits_{1 \leq n \leq X} \mu(n) \left[\frac{X}{n}\right] = 1.$

I'm currently sitting with the following number theory problem:  Prove that for all $X \geq 1$, $$\sum_{1 \leq n \leq X} \mu(n) \left[\frac{X}{n}\right] = 1.$$  A few ideas I have tried: Using that $[x]=x - \{x\}$ which I couldn't make out to bring anything. Switching around on the summation variables, like $$\sum_{d \leq N} \mu(d) f\left( \frac{n}{d} \right) = \sum_{d \leq N} \mu \left( \frac{d}{n} \right) f(d)$$ but that didn't seem to bring anything.  I tried writing out the first few terms, which give $$\mu(1) [X] - \left[\frac{X}{2}\right] - \left[\frac{X}{3}\right] - \left[\frac{X}{5}\right] + \left[\frac{X}{6}\right] - \left[\frac{X}{7}\right] - \left[\frac{X}{8}\right]$$ but I can't seem to find a system where it simply reduces to one!  What do you think?


Why can't you update a value of a nested property in an object directly?

I was playing around in React Native and came across this error. I don't understand why the first snippet throws an error, while the second one runs fine. This does not work: let newContent = { ...oldContent }; // <-- oldContent is a 'const' newContent.value = newValue; // <-- property at 'root level' can be modified newContent.nested.a = b; // <-- throws 'You attempted to set the key with the value on an object that is meant to be immutable and has been frozen.'   But this works fine: let newContent = { ...oldContent }; newContent.value = newValue; newContent.nested = {    a: b, }  The value of nested.a is defined on oldContent. Is this expected behaviour or am I doing something wrong in the first snippet?


When I studied how AC mains power works, I learned that one of the wires is connected to the ground or a body of water so that it can get back to the power station. The concept baffles me. Every source of information I've come across fails to explain how it works or quickly glosses over it as if it is self explanatory.   If power can travel through the water or the earth back to the power station, then why aren't we getting vaporized when we walk on the ground near power lines?  Also, how does an isolation transformer prevent you or your equipment from getting fried? If I touch both terminals of the secondary, am I going to get fried?


In a TV programme, the host asked a person about the literacy rate of his city. The person replied 96%. The host then looked at the camera and said, "Wow, can you believe that?"  My question is about the use of that; if he had used this instead of that, would it be wrong?


I recently corrected  "ghettos, such as the ones found..." to "ghettos, such as those found..."  Was I correct, or are both versions right?


Why is Intel Turbo Boost Not Working On My Laptop?

Investigation continued      Dell Latitude E6420 is my laptop with Windows 7 Enterprise. Turbo Boost is enabled in BIOS but is disabled in OS according to AIDA64. I managed to install Intel Turbo Boost Monitor but it says that Turbo Boost is not enabled. Although I still see standard speed but I also see "Energy Saver" appears when CPU runs at less than standard speed.  What is interesting is that Turbo Boost gets enabled in OS only when SpeedStep is enabled as well in BIOS. This slows down CPU to ~700Mhz and stays there no matter what. Enabling\Disabling C-State did not do anything and there is no multiplier.  Intel Chipset Utility is the latest version and I did not find any Turbo Boost driver, nor any service in Administration.  I have found drivers package for my model . The problem is that i do not know what is responsible for Turbo Boost.


Did Voldemort know that Snape was trying to save Harry, since Quirrell certainly knew?

In , a good answer is given regarding how Snape shot down suspicions that he was a double-agent by explaining his opposition to Quirrell in the matter of the Philosopher's Stone. Snape didn't know that Voldemort was back (possessing Quirrell), and he was opposing Quirrell, not Voldemort. Snape was brilliant.  But it doesn't seem to me that this would also explain why Snape would stop Quirrell killing Harry Potter during the Quidditch match. In the movie, Quirrell tells Harry what happened and of course Voldemort's right there hearing it all from the back of Quirrell's head -- if he didn't know from the start, or perhaps even directed Quirrell's efforts to kill Harry in the first place.  Wouldn't Snape's defense of Harry raise a second suspicion that could not be as easily answered as the first?


"The queen of England's crown" or "The queen's of England crown"?

Possible Duplicate:          What is the correct way of these two sentences?   The queen of England's crown The queen's of England crown   Strictly linguistically, sentence 2 should be the correct one, since the crown belongs to the queen and not to England but it sounds really awkward to pronounce.


Why shouldn't we call it UX design or us UX designers?

I came across multiple different reasons why UX design should not be called design or why a UX designer is not really the designer of user experiences.  For example:  User experience (UX) cannot be designed or crafted because:   UX depends on the user and each user is different UX depends on the context in which the product is used UX evolves over time ... (add reasons yourself)   Can it be that the above reasons make it very hard for us to design a good user experience but not necessarily make it impossible to do so?  Let's consider it is not possible to design, but can we influence it?  UX design/designer is a buzzword. But isn't this a good thing? Buzzwords get things sold (see cloud-computing) and is giving the field a lot of positive intention.  If we are aware of our limitations, for example: that a user's experience depends on a lot factors which we cannot directly influence), should we be concerned about using the right terms?  What other terms are available to pick from? (for field (UX design) and function (UX designer)  N.B.: I know a lot of different subquestions are included, but they all relate to my first questions. Feel free to pick all or just a few to answer.  Reference  on Smashing Magazine  Not sure of the date, but similar  from the people at Zurb


Why cant I input an array directly into a print statement?

I have the following code.  import java.util.Arrays;  public class Practice {        public static void main(String[] args) {         System.out.println(checkEquality({1,2,3},{1,2,3}));     }      public static boolean checkEquality(int[] a, int[] b) {         return  Arrays.equals(a,b);     } }   I am trying to write a method that checks for equality between two arrays of type int. The code as written doesn't compile, giving me an illegal start of expression error for line 11 (the one which has the print statement). However if I first define two arrays in the main method  int[] a= {1,2,3}; int[] b= {1,2,3};   and then change   System.out.println(checkEquality({1,2,3},{1,2,3}));   to System.out.println(checkEquality(a,b));  the code compiles and works as it should, giving me true.   My question: why can't I input the two arrays that I want to check for equality directly into the print statement? This has worked with all other methods that didn't have array, ex expressions involving integers and strings.  Am I doing something wrong here or is this generally not possible? If so, why?


evaluate the limit as $x$ approaches $0$ of $(\cos x-1)/x$ without l'Hopital's rule

I know with l'Hopital's rule it becomes $-\sin(x)$ which has the limit $0$. However, I have been wondering how to evaluate this limit without l'Hopital's rule.


$$\int_0^1 \frac{\arcsin(x)}{x}dx$$  This is a proposed for a Calculus II exam, and I have absolutely no idea how to solve it. Tried using Frullani or Lobachevsky integrals, or beta and gamma functions, but I can't even find a way to start it. Wolfram Alpha gives a kilometric solution, but I know that cannot be the only answer. Any help appreciated!


I recently deleted all of my pictures by mistake from my samsung galaxy s4. I went into my files and documents and deleted not realising it would delete all my pics!    Is there a way for me to recover them?    My phone is not rooted. I have not taken any pictures since but have received pictures through whatsapp?


I'm trying to create a table with dashed separators between my subcolumns. This is the kind of result I need (with | representing continuous separators and ╎ representing dashed separators): +----------+-------------------+ |Data group|Stats              | +----------+-------------------+ |A         |Q1   ╎Med    ╎Q3   | +----------+-------------------+ |B         |Q1   ╎Med    ╎Q3   | +----------+-----+-------+-----+  Is there a way to do it? A specific column separator to use in the \begin{tabular}{|l|l|l|l|}?


Why do LaTeX internal commands have an @ in them?

Does the @ mean anything specific? For example, is it substituted? Does it split the command into parts, like \s@foo could internally mean "foo of type s"? Is the purpose of the @ only to make internal commands break when used outside a class definition or a package? If so, how is that a Good Thing?


Jacobson radical in $A[x]$ where $A$ is a ring.

Let $A$ be a commutative ring, and $A[x]$ be the ring of polynomials in an indeterminate x, with coefficients in A. I found several proofs online that in this case the Jacobson radical equals to the nilradical, and to prove the non-trivial direction (Jacobson radical included in the nilradical), they all used the fact that if $f=a_0+a_1x+...+a_nx^n$ is an element of the Jacobson radical, then $1+fx$ is a unit, but I couldn't see why. Can anyone please clarify that for me?  I'm not looking for a proof, I'm just looking for an explanation about why $1+fx$ is a unit.


How to tell Drupal to look for templates in module directory?

I'd like to provide template implementation in my module and allow themes to override it. Basically, I add a suggestion by this simplified code:  function attach_preprocess_node(&$vars) {   $vars['theme_hook_suggestions'][] = 'node__test'; }   (I don't want to use hook_theme to add a new theme because I want to reuse preprocess node functions. The theme name are awkward but I don't want to write node_attach_% to avoid confusion with node type.)  Then I use hook_theme_registry_alter() to add module path:  function attach_theme_registry_alter(&$theme_registry) {   $path = drupal_get_path('module', 'attach') . '/themes';   $theme_registry_copy = $theme_registry;   _theme_process_registry($theme_registry_copy, 'phptemplate', 'theme_engine', 'node', drupal_get_path('module', 'node'));   $theme_registry += array_diff_key($theme_registry_copy, $theme_registry);   if (!isset($theme_registry['node']['theme paths'])) {     $theme_registry['node']['theme paths'] = array();   }   if (!isset($theme_registry['node']['theme paths'])) {     $first_element = array_shift($theme_registry['node']['theme paths']);     if ($first_element) {       array_unshift($theme_registry['node']['theme paths'], $first_element, $path);     }     else {       array_unshift($theme_registry['node']['theme paths'], $path);     }   } }   However it does not work. That means: the file themes/node--super.tpl.php is not used. It is used only if I copied it to the theme folder.


Is there any integer $p$ such that $p > 1$ and all three numbers $p$, $p+2$ and $p+4$ are prime numbers? If there are such triples, prove that you have all of them; if there are no such triples, prove why not. Apart from this, I am given the following information: if $a$ is an integer, then precisely one of the following holds: either $a = 3k$ for some integer $k$, or $a = 3k+1$ for some integer $k$, or $a = 3k+2$ for some integer $k$. I have observed that, when you sum $p$, $p+2$ and $p+4$, you get $3(p+2)$. But from that, I don't know how to proceed.


Why can't we calculate the absolute velocity of the Earth using the speed of light?

We know that the speed of light is always constant in space no matter the speed of the object emitting light, right?    Now consider this. An object is moving at half the speed of light and shined 2 beams of light; one in the direction it is moving and one in the opposite direction. If it was possible to see the beam of light, it would appear from the perspective of the object, that the beam of light moving in the same direction as its moving would appear to be moving at half the speed of light, and the beam of light opposite of the direction of the object would appear to be moving at 3/2 the speed of light.    Now, to apply this concept to something more possible. In theory, a device consisting of 3 laser beams, and 3 sensors could be able to calculate the absolute speed and direction it is moving in the universe. Say we made a device with 3 lasers set up so that they are all perpendicular to one another and sensors with known distances from the lasers, and all of this is occurring in a vacuum, then all at the same time the lasers would shoot at their respective sensors, and the times it took for the light to reach the sensors were recorded. The velocity of the lasers from the perspective of the device could then be calculated by using distance over time. Using the apparent velocity of the laser, the velocity of the object in the direction of the laser could be calculated by subtracting the apparent velocity from the speed of light. Then using these 3 velocity measurements, you could measure the speed that the device is moving through space itself. Using this device, it would be possible to measure the velocity of Earth at any point in time.    After researching the speed the Earth is moving, I saw that the method of figuring this out involves background radiation in the universe. Why would my method be discarded and the background radiation method be used instead. Surely I am not the first to think of this. Why would my method not be used?  Edit: I am aware that the speed of light is constant no matter what. Just it can seem to be going at 3/2 or 1/2 the speed of light from the perspective of something also in motion in the same way that a car going 60mph views a car going 90mph as going 30mph faster than it, or just 30mph in the perspective of the 60mph car.


How to know what size of bike is suitable for your height and weight?

There are many parameters when buying a bike, but the important one is the bike size. I want to know how to get the specs for the bike. Any good websites that help you in this regard?


i am using asus k501u and i lost my password

My Asus K501U was running Win10 and i forgot my password and could not login. I do not know how to setup the laptop to bootup from the external CD ROM. The external CD Drive is SAMSUNG. I had done the below:  Secure Boot menu - Secure Boot Control [Disabled] Launch CSM [Enabled] Plug in the Samsung CD drive with the Win10 bootup disk. Power on and pressing 'esc' On the screen can only see 'Windows Boot Manager' Selected 'Enter Setup' Selected 'Boot' ---> Add New Boot Option' ---> 'Please advise me what i should type here'  Thank You Ken Cheong


Is it ok to put old papers on the arXiv?

In my field (I am a condensed-matter theoretical physicist) it is such a normal thing to put papers on the arXiv, that people sometimes look at other people's arXiv list of papers instead of their publication record to get to know what they do, etc.  It just so happens that a few years ago I did a PhD with a supervisor that does not like the arXiv that much (he apparently had some conflict with some authors of a paper that was very similar to one of his papers, but one was already published while the other was just an arXiv preprint -or something like that). As a result, from my list of less than 20 publications, there are four of them from my PhD that are missing on the arXiv.  I was thinking of submitting the latest versions I have of them as arXiv preprints now, four years after their publication. For this I already have the agreement of all co-authors (including my supervisor), and all the journals involved seem to allow to put preprints of the material they publish. Do you see any problem with this? I fear that some people might take it as a way to advertise as new something that was already published a long time ago (though I would of course give the full reference to the published version). There may be other issues I am not aware of. The reason why I would like to do this is that I am applying for fellowships, positions, etc. and I am afraid some of my (best) publications may go unnoticed if somebody looks me up on the arXiv.  Thank you, Stephen


Dash to dock in ubuntu 20.04 appears twice

In ubuntu 20.04 dash to dock extension the dock appears twice after lock or suspend.


How to combine two different raster by replace its raster value at their overlap space?

I have two different raster data :   First data :  Second data    How to combine those raster data? so the output data will be like this :    Where the overlap space between First data and second data (the green one) will contains the value of second data and the other will be refer to first data. So there will be two value in one raster data. A solution by using ArcGIS will be more preferable.


Removing additional middle name with biblatex

i'm using biblatex with apa style. I have some authors that have too many middle names. It give me something like this :     Licht, C. M. M., de Geus, E. J. C., van Dyck, R., & Penninx, B. W. J. H. (2009). Association be- tween anxiety disorders and heart rate variability in The Netherlands Study of Depression and Anxiety (NESDA). Psychosomatic medicine, 71(5), 508–518   instead I would like to have something like this with a maximum of two middle name :     Licht, C. M., de Geus, E. J., van Dyck, R., & Penninx, B. W. (2009). etc...   I can't find any nice way of doing that (without deleting the additional names from my bib entry). Hope you can help me.  This is the MWE :  \documentclass{article} \usepackage{filecontents}  \begin{filecontents*}{demo.bib} @article{Licht2009, abstract = {}, author = {Licht, Carmilla M M and de Geus, Eco J C and van Dyck, Richard and Penninx, Brenda W J H}, doi = {10.1097/PSY.0b013e3181a292a6}, issn = {1534-7796}, journal = {Psychosomatic medicine}, number = {5}, pages = {508--518}, pmid = {19414616}, title = {{Association between anxiety disorders and heart rate variability in The Netherlands Study of Depression and Anxiety (NESDA).}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/19414616}, volume = {71}, year = {2009} } \end{filecontents*}  \usepackage[backend=biber,style=apa,citestyle=authoryear,natbib=true,uniquelist=minyear,doi=false]{biblatex} \bibliography{demo}  \begin{document}     A reference to : \cite{Licht2009}  \printbibliography \end{document}   Thanks. br.


What is the adjoint of an inverse matrix? Is $(T^{-1})^{*} = (T^{*})^{-1}$?


I am trying to use the Blender cycles standalone plugin with the xna app to render scene. But I am stuck as I don't know the structure of the camera matrix. In xna view matrix structure is  . Can somebody explain the same for  Blender?


Electricity takes the path of least resistance?

Electricity takes the path of least resistance!   Is this statement correct?    If so, why is it the case?  If there are two paths available, and one, for example, has a resistor, why would the current run through the other path only, and not both?


How to add a Japanese name that does not appear in the Kotoeri registry? (OS X 10.11)

On OS X 10.11 El Capitan, I am trying to add a word to the Kotoeri lookup dictionary. It is a name that does not come up when you type the Hiragana. The way to do it pre-10.10 no longer works. How can I add the word?


Are relationships allowed between students and faculty?

What sorts of restrictions do universities place on romantic or sexual relationships between faculty and graduate students, and what are the underlying issues that motivate these restrictions?  For example, suppose the student has previously taken a class from the professor but has no plans for further academic contact.  What other factors could help determine whether a relationship would be allowed or considered appropriate?


what does #!/bin/bash at the 1st line mean ? Is it just a comment and ignored by the shell like all other comments in program   OR  Only this line is interpreted by the interpreter and all the other lines starting from # are ignored except #!/bin/bash.


Windows 10 recovery without local administrator

I have a company laptop (a Lenovo T540) running Windows 10. I am using a domain user to access the computer. That user has administrator privileges. A few days ago, Windows did a Windows Update, rebooted and then failed to start. After the Lenovo splash screen the screen stays black with no further progress.  Holding Shift+F8 during boot shows the Windows 10 recovery menu. However, trying to do any action gives the following error:     You need to sign in as an administrator to continue, but there aren't any administrator accounts on this PC.   Using a recovery USB created from another Windows 10 machine does allow all of the actions from the recovery menu to start, but they all give an error.  At best I would like to use the System Restore to go back to before the Windows Update was installed.  I have some important files still on the drive of the laptop, and would rather not have to do a clean reset of the Windows 10. Is there a way to work around that error?


Finding the limit of $a_{n} = \frac{1}{2}(a_{n-1}+a_{n-2})$ for arbitrary $a_{0}$ and $a_{1}$.

Here is the problem statement:  Let $a$, $b$ $\in$ $\Bbb{R}$. A sequence $(a_{n})_{n \in \Bbb{N}}$ is defined recursively by $$a_{0}:=a, \qquad a_{1}:=b, \qquad a_{n} = \frac{1}{2}(a_{n-1}+a_{n-2}) \quad \text{for} \quad n \geq 2.$$ Prove that $\lim_{n\to\infty}a_{n}$ exists and compute its value.  Now I have proved that the limit exists. My idea was to use the Monotone Convergence Theorem as follows: Proof: Without loss of generality, assume $a<b$. By inspection of the first two terms of $a_{n}$, we see that $$a_{3} = \frac{1}{2}(a_{2}+a_{1})=\frac{1}{2}\left[\frac{1}{2}(a_{1}+a_{0}) + a_{1}\right] = \frac{1}{2}(a_{1}+a_{0})+\frac{1}{4}(a_{1}-a_{0})=a_{2}+\frac{1}{4}(a_{1}-a_{0})>a_{2} \quad (\because a_{1}>a_{0}).$$ Therefore we need to show that the sequence is increasing, so our inductive hypothesis is $a_{n}<a_{n+1}$. $$a_{n}<a_{n+1}\implies a_{n+1}=\frac{1}{2}(a_{n}+a_{n-1})<\frac{1}{2}(a_{n+1}+a_{n})=a_{n+2}.$$ Thus $a_{n}$ is increasing for $n\geq 2$. Now we need to show that it is bounded. By inspection, $a_{3}=\frac{1}{2}(a_{2}+a_{1})<\frac{1}{2}(a_{1}+a_{1}) = a_{1}$, and $a_{4}<a_{1}$ and so on. So again assume by induction $a_{n}<a_{1}$ and we have $$a_{n+1}=\frac{1}{2}(a_{n}+a_{n-1})<\frac{1}{2}(a_{1}+a_{1}) = a_{1}.$$ Thus $a_{n}$ is bounded above. Hence by the Monotone Convergence Theorem, sequence is convergent and $\lim a_{n}$ exists.$\quad\square$ However, I'm stuck in finding the limit. Any hints would be appreciated.


How to calculate: $\sum_{n=1}^{\infty} n a^n$

I've tried to calculate this sum:  $$\sum_{n=1}^{\infty} n a^n$$  The point of this is to try to work out the "mean" term in an exponentially decaying average.  I've done the following:  $$\text{let }x = \sum_{n=1}^{\infty} n a^n$$ $$x = a + a \sum_{n=1}^{\infty} (n+1) a^n$$ $$x = a + a (\sum_{n=1}^{\infty} n a^n + \sum_{n=1}^{\infty} a^n)$$ $$x = a + a (x + \sum_{n=1}^{\infty} a^n)$$ $$x = a + ax + a\sum_{n=1}^{\infty} a^n$$ $$(1-a)x = a + a\sum_{n=1}^{\infty} a^n$$  Lets try to work out the $\sum_{n=1}^{\infty} a^n$ part:  $$let y = \sum_{n=1}^{\infty} a^n$$ $$y = a + a \sum_{n=1}^{\infty} a^n$$ $$y = a + ay$$ $$y - ay = a$$ $$y(1-a) = a$$ $$y = a/(1-a)$$  Substitute y back in:  $$(1-a)x = a + a*(a/(1-a))$$ $$(1-a)^2 x = a(1-a) + a^2$$ $$(1-a)^2 x = a - a^2 + a^2$$ $$(1-a)^2 x = a$$ $$x = a/(1-a)^2$$  Is this right, and if so is there a shorter way?  Edit:  To actually calculate the "mean" term of a exponential moving average we need to keep in mind that terms are weighted at the level of $(1-a)$. i.e. for $a=1$ there is no decay, for $a=0$ only the most recent term counts.  So the above result we need to multiply by $(1-a)$ to get the result:  Exponential moving average "mean term" = $a/(1-a)$  This gives the results, for $a=0$, the mean term is the "0th term" (none other are used) whereas for $a=0.5$ the mean term is the "1st term" (i.e. after the current term).


Ubuntu 16.04.1 has appeared as .rar file. How do I burn it to a disk to use to install Ubuntu?

I am interested in using Ubuntu for the fist time, so I went to the Ubuntu download page (), to get the download file. When the file downloaded he file, it appeared in WinRAR, so I cannot burn the file to a DVD. Can anybody point me in the right direction as to how to burn this file to a DVD when the file appears as a WinRAR file? Any help would be great appreciated. Thanks :)


In which comics did Batman become a murderer or a psychopath?

List of comics in which Batman became a murderer or a psychopath? That is someone else had to stop Batman.


Let <A,≺ > is a linear ordered set which does not have a largest element. For a set X, X ⊆ A, is said to be cofinal with A, if: (∀a ∈ A)(∃x ∈ X)[a ≺ x]. Prove that there exists B, B ⊆ A, which is cofinal with A and <B,≺> is well ordered set. My attempt: Will use recursion,namely if we define a property φ, such that for ∀x∃y(φ,x,y). Then for every A there exists set B, such that:∀y(y∈B)↔(∃x|x∈A & (φ,x,y) ). But this property φ,x,y I will use to define a surjection over an ordinal α-the largest limit ordinal which I will consider to be Limit(α), here I use the fact that ¬max α'∈A. This surjection will be: f:α ↦A. Which for an arbitrary x∈α will return s(x)≤α,namely f(x)=s(x). If however x>a, then x=α+n. Hence we have showed the existence of such x:a ≺ x. Then this says that for this defined operation and the set A, there exists other set B(unique) satisfying the property. However I do not know what else I need to do to get further.


Kernel and Image of a group homomorphism

let $G$ be   a multiplicative group of non-zero complex analysis.consider the group homomorphism $\phi:G\rightarrow G$ defined by $\phi(z)=z^4$.  1.Identify kernel of $\phi=H$.  2.Identify $G/H$  My try:  let $z\in \ker \phi$  then $\phi(z)=1\implies z^4=1$ let $z=re^{i\theta}\implies r^4\cos 4\theta =1;r^4\sin 4\theta =0$   then $r=1$ and $\tan 4\theta=0\implies 4\theta=0\implies \theta=\frac{n\pi}{2}$  Is it correct?  I cant proceed in the 2nd problem.  Any hints in this regard.


How to obtain the optimum model using Keras? Deep Learning

There are too many parameters while building an artificial neural network. Some of which that comes to my mind are:  Number of layers Types of layers Number of nodes in each level of layer Activation functions in each layer Ordering of the layers Different types of optimizers Different types of loss functions Batch size while fitting Epochs while fitting  The lone fact that the number of layers might be in the order of tens and the number of nodes might be in the order of thousands implies that we can end up with billions of different combinations. Considering all the parameters in the list above, how can one know that their model is close to the optimum ? The cases I study on does not require me to be too precise in terms of r2_score. In other words, it would not make a huge difference if the r2_score is 0.85 or 0.87. But the question is how do I know if I am real close to the saturation point of the r2_score for the given data, i.e. the optimum model would yield an r2_score of 0.90 and I am not stuck at 0.80?


How to install Ubuntu 20.04 LTS with a USB, on Windows 10 for a DualBoot?

Unebootin just doesn't work for me. Is there any other way?


A person holds a bundle of grass over his head for 30 minutes and gets tired. Has he done some work or not please explain me?


Remember English keyboard layout in browser address bar (Ubuntu GNOME)

How to automatically prevent typing in browsers address bar for non English keyboard layout?


Tracing a monochrome image into a 3D, extruded object with a script

Say I want to automate making extruded-text or a 3d logo from an image.    An answer that uses extruding a monochrome image of the ubuntu logo to an arbitrary number of units with a python script taking only the number of units and the monochrome image as a starting point will receive extra this was awesome re-posts from me.  This could be useful for lots of things.


Check and Retrieve those results where a cell(row) contains atleast one value from many values in a column

Let me give you an example :  I have a table (name = posts) which contains following rows:    id    |    title   | .... |  names     1    |      .     |   .  |     .    |      .     |   .  |     4    |     ABC    |   .  |  joe  , nash  , brad     5    |     XYZ    |   .  |  jeff , michael ,gerard, pique     6    |     JKQ    |   .  |  archeo , michael ,neymar, schultz   Another table (name = followed) containing rows:    id    |  names     1    |  jeff     2    |  michael     3    |  cheryl     4    |  zohan    Given : Two tables To fetch : Titles from posts table where names.posts contains atleast one name from names.followed in followed table Result I should get in the above example : XYZ , JKQ query form : mysql , PDO   I dont know if its possible .The reason I am storing values in cells with names concatenated with commas is to reduce redundancy. I have basic query knowledge only .If its possible it will be great if some one can answer me a query/queries to get asked result . If not possible just give me an alternative method with a different table structure and an explanation why its the best alternative solution . Big Thanks to all who can help me in any way possible


I am looking to be able to tell how many records, i.e., db-table rows, a jdbc query returns without iterating through the resultset.   I tried -- however didn't work the way I thought it would:          if (rSet.getFetchSize()==0)          System.out.println("no results returned");         while (rSet.next())             System.out.println(rSet.getString("transactionID"));         rSet.next();   The above code snippet prints the first console message, then gets into the loop and iterates to execute the second console message on 1+ results.   How to tell the number of records fetched? what's ResultSet.getFetchSize() for?  //-----------------------------------  EDIT: looking to tell this count without any iterations on the ResultSet. convinced that this isn't possible though. the answers to the referred Q are saying so.


Our development environment consist of JBoss 5.0.1 DB Server, SQL Server 2008, Oracle IDM. Hardware is Win 2008 32 bit, 4GB RAM. We have reached stage where our environment can not handle application resulting in JBoss shut down throwing out of memory errors and CPU reaching to 90% usage. I am looking methodology to calculate correct server sizing where I input TPS, max number of concurrent users, max CPU utilization etc.. to give me number of servers, RAM size, number of cores. I am expecting application to grow 10% annually. Load Balancer and Failover should also be taken in account while sizing.


Integration by parts, trig substitution u or dv?

I have been attempting to solve an integration expression.  The exression I am attempting to solve:  $$\int_0^1 {\frac{3x^3-x^2+2x-4}{\sqrt{x^2-3x+2}}}\mathrm{d}x.$$  I have approached the problem from a few different angles, but I'll only touch on the solution that seems promising.    It appears to be an integral of the product of two functions of x, so integration by parts is currently the most favorable approach (versus simple substitution/partial fractions).     $$\int {u\mathrm{d}v} = uv - \int {v\mathrm{d}u}$$  We only need now to define $u$ and $\mathrm{d}v$ appropriately.  For now, I will ignore the polynomial in the numerator as this is a straight forward function to integrate or find the derivative.    Let's turn our attention to the second function of $x$ in this integrand, which will for now be considered to be $\mathrm{d}v$:  $$\mathrm{d}v = \frac{1}{\sqrt{x^2-3x+2}}\mathrm{d}x$$  Unfortunately, this is not a perfect square, but I do see were are able factor $(x-1)^2$ providing us with a classical trig substitution possibility.  $$\mathrm{d}v = \frac{1}{\sqrt{(x-1)^2-1}}\mathrm{d}x$$  If we substitute $(x-1) = \sec(w)$, then $\mathrm{d}x = \sec(w)\tan(w)\mathrm{d}w$ and our equation solves to:  $$\mathrm{d}v = \frac{1}{\sqrt{\sec^2 w-1}}\sec{(w)}\tan{(w)}\mathrm{d}w = \frac{1}{\sqrt{\tan^2{(w)}}}\sec{(w)}\tan{(w)}\mathrm{d}w$$  $$\mathrm{d}v = \sec{(w)} dw$$  which then gives   $$v = \ln{|\sec{(w)} + \tan{(w)}|}$$  This is where I can't seem to finish this off.  I need to convert this back to a function of $x$, not $w$ otherwise I end up with a strange integral involving the polynomial derivitive, $du$ as a function of $x$ and then as a function of $w$.     I can obviously handle the $\sec$ function, but the $\tan$ I can not convert back to a simple function of $x$.    And unless there is a trig trick here, I don't see how this can be used in the remaining integral $\int{v\mathrm{d}u}$  Conversely, we could say that  $u = \cot{w}$ and $\mathrm{d}u = -\sec^2{(w)}\mathrm{d}w$  and again, I don't see how to use this in the remaining integral.  $$(x-1) = \sec{(w)}$$  $$\mathrm{d}x = \sec{(w)}\tan{(w)}\mathrm{d}w$$  thus  $$\mathrm{d}u = \frac{-(x-1)^2}{\sec{(w)}\tan{(w)}}\mathrm{d}x$$  I am not sure how to convert back to a single function of $x$. Maybe I'm spacing on a tangent identity that would help me.    Just to clarify, I've tried factoring out polynomials in the numerator such as $(x-1)$, $(x-2)$ which do factor, but not both of them, as well as $2x-3$ (perhaps making substitution possible) but to no avail.  I haven't been able to simplify the problem more than this.  Any thoughts?  EDIT-  I guess I made a mistake with my denominator factoring.    All thing considered, the integral seems to simplify to:  $\int_0^1 {\frac{3x^2+2x+4}{\sqrt{\frac{(x-2)}{(x-1)}}}}$  I will try a few things from this.


I'm a entry-level graphic designer. My skills in Illustrator and Indesign are pretty strong but my skills in Photoshop are not great and I have no drawing skills either. Will this affect my career?


How can an author get assurance that his work will not be stolen by journal staff or reviewers?

Suppose some author provides his original research article to a journal for publication. In this way, he is disclosing or revealing his confidential research work to that journal. Now, consider the case that his article gets rejected. So, is it not possible that whoever reviews that article can publish that kind of work and say that it's theirs? Since the original author's work has not been published and he is disclosing his confidential work to somebody, how could the author get assurance that if his article is rejected, his work will not be leaked by the journal staff in any form? What happens if this kind of thing happens?


How to add self defined environment to verbatim environments

Using the following code in emacs configuration file makes the listed environment as verbatim.  (setq LaTeX-verbatim-environments-local '("Verbatim" "lstlisting"))   How can I add following environment to this list.  \lstnewenvironment{code}[2][]{%  \lstset{#1}%  \mdframed[style=lstlisting,title={#2}]% }{\endmdframed}   I have tried the following but its not working  (setq LaTeX-verbatim-environments-local '("Verbatim" "lstlisting" "code"))


What does * next to the file name mean in the output of ls?

I have a doubt related the output of ll command.  When, in my shell, I execute the ll command I obtain this output:  -rwxrwxr-x 1 andrea andrea 104215 ott 15 15:56 atmosfs*   Why I have the * next to the file name atmosfs? What does it mean?


Is $\exists x(P(x)\rightarrow\forall y P(y))$ a tautology?

This is from the book by D.J. Velleman-"How to prove it?" Sec 3.5 Excercise 31:  Prove $\exists x(P(x)\rightarrow\forall y P(y))$  Suppose the universe of discourse is set of all men.   Let statement P(x) $:=$ $x$ is married. Then $\forall yP(y)$ means all men are married. Thus, there exists a man, if his marital status is married that means are all men are married. Am I interpreting the statement correctly? It is not abvious to me why this statement is true at all.


Is there an Java equivalent to the WPF platform?


Very basic question: how do I write a short literal in C++?  I know the following:   2 is an int 2U is an unsigned int 2L is a long 2LL is a long long 2.0f is a float 2.0 is a double '\2' is a char.   But how would I write a short literal?  I tried 2S but that gives a compiler warning.


Sampling data to have specific mean and standard deviation

I have a data that I want to sample such the resultant distribution of values should have specified mean and standard deviation. I can think of rejection sampling to achieve this however that seems to be overkill as rejection sampling tries to match complete distribution while I need only first two moment to be equal to specified value. There have to be easy way to do this and also multiple ways.   The current data have distribution    Min.    1st Qu.     Median     Mean     3rd Qu.    Max.    0.0020  0.2120      0.3880     0.4298   0.6040     1.0000    I want it to have mean of 0.2236  and standard deviation of  0.3180463.


I know that $100!$ is $100\times99\times98\times...2\times1$ but I don't get how to get all the factors of three from this. Help!


Indefinite integration of a function with a trigonometric function raised to a high power

I need to integrate indefinitely the expression  $$      \frac{\csc^{2}x - 2017}{\cos^{2017}x}  $$  I am unable to handle this high power of $\cos(x)$ . A hint would be useful for me.


how to format my computer, wipe out windows, and set it with only ubuntu?

I am absolutely new to linux and don't know a whole lot about this, but I'm trying to learn!    I already looked through old questions and it seems that usually the installation of Ubuntu offers the option of replacing the old windows instead of running Ubuntu alongside it, but I never got that option.  Because my computer is a two year old netbook and is getting super slow, I would like to format it and run only one OS, just need it for the basics (School, email, music...).    So now, I have both Ubuntu (I think its 12.04.3 LTS) and Win 7 Starter on my computer, how should I go about this?


How do I fix "Unable to correct problems, you have held broken packages"?

I have problems downloading and installing several software packages.  This is what I get every time: some broken packages.  $ sudo apt install i3 Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  i3 : Depends: i3-wm (= 4.16.1-1~~xenial1) but it is not going to be installed       Recommends: i3lock (>= 2.2) but it is not going to be installed       Recommends: suckless-tools but it is not installable       Recommends: i3status (>= 2.3) but it is not going to be installed       Recommends: dunst but it is not installable E: Unable to correct problems, you have held broken packages.   My Ubuntu version is 16.04.  As asked for, the contents of /etc/apt/sources.list.d/sur5r-i3.list:  deb https://debian.sur5r.net/i3/ xenial universe


Why does Java throw NullPointerException using HashMap with Dagger?

First I create Dagger Component and Module. @Singleton @Component(modules = {UploadModule.class}) public interface UploadComponent {     void inject(UploadS3ToMap requestHandler); }  Module: private Map<String, String> uploadMap = new HashMap<String, String>();  @Singleton @Provides Map<String, String> getUploadMap() {     return uploadMap; }  And than trying to use it in my Class: @Inject Map<String,String> getUploadMap;  getUploadMap.put("test", "testIssue"); return getUploadMap.toString();  And I have an Exception: nulljava.lang.NullPointerException What is wrong with it?


Does Change Data Capture (CDC) work in a SQL Server 2012 AlwaysOn Failover Cluster Instances setup?

Does  work in a  setup?  There would be two nodes in the AlwaysOn Failover Cluster Instances setup and two Domain Controllers.  We are not using AlwaysOn Availability Groups.  Will CDC work? and will it failover?


How would you solve the next ODE?  $$\frac{dy}{dt} = \frac{at + by + m} { ct + dy + n},$$  where $a, b, c, d, m, n$ are constants and $ad = bc$.  Corrected.


For a given plaintext-ciphertext pair, how many valid AES keys are there?

For $PT\in \mathbb{M}$ and $CT\in \mathbb{C}$, let $\mathbb{F}=\{f|f:\mathbb{M}\rightarrow\mathbb{C}\}$ be the collection of all functions from $\mathbb{M}$ to $\mathbb{C}$. Then AES encryption under key $k$ is one of these functions, say $f_k$, such that $f_k(PT)=CT$. Then,   Is there any key $k'$ such that $k\neq k'$, but $f_k(PT)=f_{k'}(PT)$? If so then is there any fixed cardinality of such sets of keys?


Is it scientifically valid to compare landcover/use generated from different types of spatial resolution products

This question is mainly for the validity of the comparison of the classification product of different types of spatial resolution.  Is it scientifically valid to compare very high-resolution image analysis product with that of moderate resolution. Say I have RapidEye image classification(8 class) of 2011 and forest loss pixels(just 3 class:forest loss, no forest loss, not applicable) of 2010 from landsat image products. Now I want to see what forest loss pixel of 2010 is converted to what in 2011.  Is it scientifically valid or not to compare product of different spatial resolution?


Does the article "a/an" apply to the parenthetical or the word that follows?

I just asked a question a moment ago, the subject of which was "Is there a word for taking an (possibly undeserved) authoritative tact?"  And I immediately had the follow up question of "was that sentence grammatically correct?" Namely, does the article a/an connect to what's in the parentheses (in which case I should have used "a") or to the adjective that follows, which the article actually refers to (in which case I did the right thing).


Question on practical quantum computing programming code

Has anyone tried any quantum computing programming code that shows or demonstrates the advantage of a quantum computer over classical computers? Thanks a lot.


What's a word for someone with low level of knowledge in an area, and no intention of going further?

Over on , people often describe themselves as "beginners" or "newbies". Nothing at all wrong with that — in fact, it's great. Both of these terms have the implication of starting at a low level now, but with the general expectation of gaining knowledge.  I want to distinguish this from someone who doesn't really want to begin at all. In photography, they may just want to take a decent picture for social media but don't actually want to learn anything or, heaven forbid, practice. But I also don't (always) mean this negatively: if that's not your interest, you're just needing to do this thing in the course of something you do care about, why should you become an actual beginner?  The same could apply to computers — I may be not very skilled at spreadsheets, but, also I don't consider myself a beginner, because I have no intention of getting better. I just sometimes find myself needing to edit them and send them around to people for my job.  Is there a word for this concept? I was thinking "tourist" — but, hopefully something less metaphorical. Sometimes people say "not a professional" or "just an amateur" with this kind of meaning, but particularly in photography that's really not the right distinction — an amateur may in fact be an expert.  This also isn't the same as "dilettante" — which does seem a perfect match for the full text of the question , because that has a) an implication of showiness I don't mean to imply and b) doesn't apply very well at all to the case of someone just wanting a basic question answered so they can get a different job done. A dilettante has — or feigns — interest in a topic (and even may pretend expertise), but doesn't really have the will to learn. I'm looking for a word for someone who doesn't even have the interest or pretense of one.  In usage: "I just want a camera that will do everything for me — I don't want this as a hobby... I'm just a _____".


A space is Hausdorff iff the diagonal is closed

Let X be a topological space. Prove that X is a T2-space if and only if $A = \{ (x,x) : x \in X \}$ is closed in $X \times X$.  I've been able to prove first part of the result but not the converse.  For the first part,  We have X is T2. hence X x X is also T2. Hence X x X is T1.  Then for any z belonging to A and y not belonging A, there exist an open set U in X x X such that y belongs to U but z doesn't belong to U.  Hence for every z belonging to A and for a fixed y not belonging to A , there exists an open set V(y) in X x X such that "V(y) intersection A" is empty.  hence (X x X) - A = Union of all V(y)'s such that y doesn't belong to A.  since arbitrary union of open sets is open, hence (X x X) - A is also open in X x X , Implying that A is closed in X x X. ( Is this proof valid ? )  Now how to prove the converse part ?


Used apt-get to install chromium but how to start it?

I am new to Ubuntu. I have installed chromium by using:  sudo apt-get install chromium-browser   Its installed but where does it go? No icon for starting it from desktop.and no icon in Applications-Internet  Please tell me how to run the program and create an icon for it and other applications which I install in future.


Bibliography only compiling for apstemplate.tex

I'm using the APS template, apstemplate.tex (found ).  I have a bib file called refs.bib file located in the same folder, and in the tex file if I call   \bibliography{refs}   all the references are generated fine (pdflatex, bibtex, pdflatex x2 yada). Great!  However, once I change the name of the tex file from apstemplate.tex to something else, like "SomeOtherName.tex", then the bibliography is not created in the output!  That is really surprising and weird, why should the ability to create a bibliography be linked to what I call the main tex file? Everything else in the tex file is unchanged.  Here's what's in the body, if it's of any relevance:  \documentclass[aps,prl, reprint, superscriptaddress]{revtex4-1} \pdfoutput=1  % You should use BibTeX and apsrev.bst for references % Choosing a journal automatically selects the correct APS % BibTeX style file (bst file), so only uncomment the line % below if necessary. %\bibliographystyle{apsrev4-1}   \usepackage{graphicx} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{color} \usepackage{soul}  \usepackage{amssymb} \usepackage{wasysym} \usepackage{dsfont} %\usepackage[pstarrows]{curve2e} \usepackage{multirow} \usepackage{epsfig} \usepackage{bm} \usepackage{amsmath,amsthm,amssymb} %\usepackage{mathtools} \usepackage{array,booktabs,longtable} %\usepackage{abstract} \usepackage{mathrsfs} %\usepackage[draft]{fixme} %\usepackage[numbers]{natbib} %\usepackage{caption} \usepackage{subfigure} \usepackage{color} \usepackage{tikz} \usetikzlibrary{decorations.markings} \usetikzlibrary{calc,shapes,positioning,arrows,snakes} \usepackage{array} \usepackage{verbatim} %\usepackage{bbold} \usepackage{dsfont} \usepackage{ifthen} %\usepackage{hyperref}   \DeclareMathOperator{\Tr}{Tr}   \makeatletter \newcommand{\thickhline}{%     \noalign {\ifnum 0=`}\fi \hrule height 1.25pt     \futurelet \reserved@a \@xhline } \newcolumntype{"}{@{\hskip\tabcolsep\vrule width 1.25pt\hskip\tabcolsep}} \makeatother   \begin{document}  %Title of paper \title{Test} \author{test name} \begin{abstract} ... \end{abstract}  \maketitle  \section{Section1} I refer to Reference \cite{SomeArticle}.  \bibliography{refs} \end{document}


Do I need a passport to visit Edinburgh in Scotland from elsewhere in the UK?

I'm visiting Scotland for the first time this week, Edinburgh. I've lived in the UK for over 10 years but my nationality is Spanish. I only have a Spanish passport.  I'm also traveling by train.  Do I need a passport to enter Scotland and stay in my booked hotel?


Recently I'm facing a problem on derangement. The problem I'm facing is asked in the link:   An answer is also given in that link. But I can't understand the answer.  Can anyone tell me the solving way with better explanation and great details.I again asked the question in the following.  A derangement of $n$ numbers is a permutation of those numbers in which none of the numbers appears in its original place.   For example, the numbers $\{1,2,3\}$ can be deranged into $\{2,3,1\}$ and $\{3,1,2\}$. We can modify this slightly for $n$ numbers that are not necessarily distinct by saying that no number in the derangement can be in the place that a number of the same value was in in the original ordering. So the numbers $\{1,1,2,2,3\}$ could be deranged into $\{2,2,1,3,1\}$, $\{2,2,3,1,1\}$, $\{2,3,1,1,2\}$, and $\{3,2,1,1,2\}$.  How can I find out the number of above derangement if a set like above is given?


What happens to the Shield Gate in the Rogue One novel?

How is the deflector shield above Scarif destroyed or temporarily disabled in the Rogue One novel? How are people able to pass through before the Death Star fires?


How will Andromeda collide with Milky Way in spite of Hubble's law?

According to Edwin Hubble our Universe is expanding because he noticed that other galaxies are moving away from us. But then how Andromeda galaxy will collide with Milky Way in ~4.5 billion years, as it should also move away from us?     I am some bit confused, please help me.


The problem says this:  Let $\sim$ be an equivalence relation in $X$ and consider the quotient space $X/\sim$. Prove that:   $X$ connected $\Rightarrow$ $X/\sim$ connected. If $X/\sim$ is connected and every equivalence class $[x] = \left \{ y\in X : y \sim x \right \}$ is connected then $X$ is connected.   Proof 1) is easy and I know how to do it. But I'm stuck in the proof 2). That's what I have tried:  Let's suppose $X$ isn't connected. Then, $X=U\sqcup V$ with $U$ and $V$ open.   Let $\pi : X\rightarrow X/\sim$ be the application that sends every $x\in X$ into his class. I want to see that $\pi (U)$ and $\pi(V)$ are open and that $\pi (U)\cap\pi (V)= \varnothing$ to conclude that $X/\sim$ isn't connected (because $\pi$ is surjective). But that is absurd, so $X$ must be connected.  I know how to prove that $\pi (U)\cap\pi (V)= \varnothing$, but I don't know how to show that $\pi (U)$ and $\pi(V)$ are open. Any advice?  Thanks!


Why not raise the individual number of Close Votes?

I'm seeing for a long time that the review for Close Votes just raises every hour, is at least 1k per day. This is out of control. I have some old flags that never was reviewed and in this way never will be reviewed.  So, why not raise the maximum number of individual reviews of 40 to 100 for example? I think this is bad for the community stay the way it is.  Someone have some other idea? Already have some ideia to make it better?


Repository does not have a Release key and public key

I'm using Ubuntu 18.04 and I'm new to this OS. After formatting my Laptop with Ubuntu OS, I installed Wine application, as well as I'm using gpg key-ring. I even have my public key and secret key and now when I want to update, it shows me many errors for example:   GPG error: http://ppa.launchpad.net/remmina-ppa-team/remmina-next/ubuntu bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8A993C2521C5F0BA   I tried to update the file sources.list and its directory from another Ubuntu system but still the same problems.


I'm new to blender and trying to model the blade of my helicopter and can't figure out how to make an edge curved (for the red tip and selected edge). The object is a plane, with one loop cut. I attempted making a bevel Ctrl B, but nothing happens (A dotted line appears attached to the cursor, moving does nothing, left-clicking does nothing).  also I cant add a curve modifier, just says its disabled. What is the correct way to model this?


I am trying to work with inner classes and I some questions about them I have a gameObject class as follows   import java.io.*; public abstract class GameObject implements Serializable {     protected enum GAME_OBJECT_TYPE {SNARK, HINT, BONUS_ITEM, INVALID};     protected GAME_OBJECT_TYPE eGameObjectType;     protected GameObject() {         eGameObjectType = (GAME_OBJECT_TYPE.INVALID);         System.out.println("SOMETHING WENT WRONG");     }     public class Snark extends GameObject implements Serializable {         public Snark() {             eGameObjectType = (GAME_OBJECT_TYPE.SNARK);             System.out.println("SNARK LIVES HERE");         }     }     public class Hint extends GameObject implements Serializable {         public Hint() {             eGameObjectType = (GAME_OBJECT_TYPE.HINT);             System.out.println("HINT LIVES HERE");         }     } }   With this GameObject class structure I get no errors but the only way I can instantiate a Snark in my GameFrame without errors is  GameObject mySnark = new GameObject.Snark();   // all good GameObject mySnark = new Snark();   // cannot be resolved   However when I change the gameObject class to   import java.io.*; public abstract class GameObject implements Serializable {     protected enum GAME_OBJECT_TYPE {SNARK, HINT, BONUS_ITEM, INVALID};     protected GAME_OBJECT_TYPE eGameObjectType;     protected GameObject() {         eGameObjectType = (GAME_OBJECT_TYPE.INVALID);         System.out.println("SOMETHING WENT WRONG");     } }     public class Snark extends GameObject implements Serializable {   // The public type Snark must be defined in its own file     public Snark() {         eGameObjectType = (GAME_OBJECT_TYPE.SNARK);         System.out.println("SNARK LIVES HERE");     } }     public class Hint extends GameObject implements Serializable {     public Hint() {         eGameObjectType = (GAME_OBJECT_TYPE.HINT);         System.out.println("HINT LIVES HERE");     } }   I can now instantiate a Snark in my GameFrame as  GameObject mySnark = new Snark();   // no errors   I can re-split each object into its own class again but it thought this may be a way to greatly reduce the number of classes that I currently have.  Can someone help me understand what I have got wrong?  Thank you


error LNK2019: unresolved external symbol "public: __thiscall list::~list(void)" (??1?$list@H@@QAE@XZ) referenced in function _main

I am trying to develop a linked list class similar to that provided in C++ STL by using doubly linked list. Everytime i run the code it gives me this error. When  calling the default constructor there is no error but when i call the paramtrized constructor it gives me this error. Header file 'list.h'   #pragma once #include<iostream> using namespace std; template<class T> class list { public:     struct Node      {     public:         T value;         struct Node* prev;         struct Node* next;     };     // deafult constructor     list();     //paramtrised constructor     list(int value, int initial_size); private:     Node* head;     Node* tail; };  'list.cpp' #include "list.h" #include<iostream> using namespace std;   template<class T> inline list<T>::list() {     head = NULL;     tail = NULL; } template<class T> list<T>::list(int value, int initial_size) {       for (int i=0; i<initial_size;i++)     {         Node* node = new Node();         node->value = value;         if (head == NULL) //list is empty         {             head = node;             tail = node;         }         else         {             tail->next = node;             node->prev = tail;             tail = node;             tail->next = NULL;         }              }           }  'Source.cpp' #include<iostream> using namespace std; #include "list.cpp" #include"list.h" int main() {     list<int> l(5,1);     return 0; }  Any help would be apprciated , thanks in advance.


Why is $\log_e(x)'=\ln(x)'= 1/x$? how to prove the differentiation rule. ofc that means also $\int(1/x)dx=\ln(x) + c$  I think that the derivative of the $\ln$ of a variable with respect to the variable being 1/x is an axiom to prove that the limit of   $(1 + 1/(ax))^{bx}$ as $x \to \infty$  is $e^{b/a}$  How to prove one without using the other and any theorem following from them ?  Or at least can we prove one of them without the other and the other should follow?


"Is not he calling me?"  "Isn't he calling me?"    Why is #1 not correct while #2 is correct? And what about the below:   "Is he not calling me?"   Does #3 always mean the exact same thing as #2 "Isn't he calling me?"


What is the number of ways to divide a rectangle into $n$ smaller rectangles line by line?

The original problem was to consider how many ways to make a wiring diagram out of $n$ resistors. When I thought about this I realized that if you can only connect in series and shunt. - Then this is the same as dividing an area with $n-1$ horizontal and vertical lines. When each line only divides one of the current area sections into two smaller ones.  This is also the same as the number of ways to make a set of $n$ (and only $n$) rectangles into a bigger rectangle. If the rectangles can be drawn by dividing the big rectangle, line by line, into the set of rectangles without lose endpoints of the line. - Can someone come to think of "a expression of $n$" which equals this amount, independent of the order of the rectangles or position?  (It is only the relations between the area sections that matters and not left or right, up or down. However dividing an area with a horizontal line is not the same as dividing it with a vertical line.)


The functions $s_1=x_1+x_2+\cdots +x_n$, $s_2=\sum_{i<j} x_ix_j$, $\cdots$, $s_n=x_1x_2\cdots x_n$ are elementary symmetric functions in $x_1,x_2,\cdots,x_n$ (or more precisely, elementary symmetric polynomials).  There are other natural symmetric functions in $x_1,x_2,\cdots,x_n$: $$t_1=x_1+\cdots + x_, \hskip5mm t_2=x_1^2+x_2^2+\cdots + x_n^2,  \cdots ,t_n=x_1^n+x_2^n+\cdots+x_n^n.$$ The two sets of symmetric functions are related by some identities, known as .  What are the simple proofs of these Newton identities? How do we prove them with some intuition or motivation?