Here is thing, I am developing a framework for other companies to use. If my framework and other companies both implement a class "ABC" and class "ABC" in framework is private framework class it wound cause naming conflict warning during runtime:      objc[1326]: Class ABC is implemented in both Some.framework/Some and heTEST.app/heTEST. One of the two will be used. Which one is undefined.   According to the warning, one of the class will be ignored. However, I did a little research and find out both class will be loaded and will not cause problem (Since class ABC in framework is private, any code outside will not be able to retrieve it. The class ABC used outside is the class defined outside by #import "ABC.h")  My questions are:  Shall I ignore this warning or how to avoid?  ps, I am tired of renaming class in framework because my framework is using several open source library(i.e AFNetworking)

Objective-C has no namespaces; it's much like C, everything is within one global namespace. Common practice is to prefix classes with initials, e.g. if you are working at IBM, you could prefix them with "IBM"; if you work for Microsoft, you could use "MS"; and so on. Sometimes the initials refer to the project, e.g. Adium prefixes classes with "AI" (as there is no company behind it of that you could take the initials). Apple prefixes classes with NS and says this prefix is reserved for Apple only. So far so well. But appending 2 to 4 letters to a class name in front is a very, very limited namespace. E.g. MS or AI could have an entirely different meanings (AI could be Artificial Intelligence for example) and some other developer might decide to use them and create an equally named class. Bang, namespace collision. Okay, if this is a collision between one of your own classes and one of an external framework you are using, you can easily change the naming of your class, no big deal. But what if you use two external frameworks, both frameworks that you don't have the source to and that you can't change? Your application links with both of them and you get name conflicts. How would you go about solving these? What is the best way to work around them in such a way that you can still use both classes? In C you can work around these by not linking directly to the library, instead you load the library at runtime, using dlopen(), then find the symbol you are looking for using dlsym() and assign it to a global symbol (that you can name any way you like) and then access it through this global symbol. E.g. if you have a conflict because some C library has a function named open(), you could define a variable named myOpen and have it point to the open() function of the library, thus when you want to use the system open(), you just use open() and when you want to use the other one, you access it via the myOpen identifier. Is something similar possible in Objective-C and if not, is there any other clever, tricky solution you can use resolve namespace conflicts? Any ideas?  Update: Just to clarify this: answers that suggest how to avoid namespace collisions in advance or how to create a better namespace are certainly welcome; however, I will not accept them as the answer since they don't solve my problem. I have two libraries and their class names collide. I can't change them; I don't have the source of either one. The collision is already there and tips on how it could have been avoided in advance won't help anymore. I can forward them to the developers of these frameworks and hope they choose a better namespace in the future, but for the time being I'm searching a solution to work with the frameworks right now within a single application. Any solutions to make this possible?


I have just searched for the usage of "until" and "by", and I was confused by these sentences. I've tried my best to tell the difference between them, and give my understanding in the bracket. Is there anybody who can tell me am I correct?   I've got to pay the money back by the end of the month. 【=pay before the end of the month】   I've got until the end of the month to pay the money back. 【=I don't need to pay it back any more, once I successfully shun the debt】   I put on an extra pair of socks. Until/By then my feet were freezing cold. 【until:my feet were no longer cold after I put on stocks】 【by:several minutes before I put on stocks I felt cold】  I stood outside the cinema for an hour. By then my feet were freezing cold. 【=in the end of the hour, my feet were cold】

Is there difference between "by then" and "until then" in the following sentence?     "I'll call you around 9 o'clock. By then (or "until then"),  sweet dreams!"


Is the following reasoning sound?  Note that $$X^4 - 2 = (X^2-\sqrt{2})(X^2+\sqrt{2}) = (X+i \sqrt[4]{2})(X - i\sqrt[4]{2})(X+\sqrt[4]{2})(X - \sqrt[4]{2}) ∈ ℂ[X],$$ so the zeroes of this polynomial generate $$ℚ(-i\sqrt[4]{2}, i\sqrt[4]{2}, -\sqrt[4]{2}, \sqrt[4]{2}) = ℚ(\sqrt[4]{2}, i) = ℚ(\sqrt[4]{2})(i).$$ Now $X^2 +1 ∈ ℚ(\sqrt[4]{2})$ has $i$ as a root, so $[ℚ(\sqrt[4]{2})(i):ℚ(\sqrt[4]{2})] = \deg(X^2+1) = 2$. Also $[ℚ(\sqrt[4]{2}): ℚ] = \deg(X^4-2) = 4$, so we conclude   $$[Ω^{X^4-2}_{ℚ} : ℚ] = [ℚ(\sqrt[4]{2})(i):ℚ(\sqrt[4]{2})][ℚ(\sqrt[4]{2}): ℚ]= 4 · 2 = 8. $$  (I believe there is a less 'ad hoc' way to do this (not using our knowledge of ℂ, bascially), which I would be interested in seeing.)

I am trying to explicitly compute the Galois group of $x^4-2$ over $\mathbb{Q}$. I found that the resolvent polynomial is reducible and the order of the Galois group is $8$ using the splitting field $K=\mathbb{Q}(2^{1/4}, i)$. Hence I need to find 8 automorphisms. Thus do I just map elements of the same order to each other that fix the base field $\mathbb{Q}$ $2^{1/4}$ to $i2^{1/4}$


Drinking sea water can be deadly as it contains too much salt, basically de-hydrating the body. Normal tap water contains little salt and is good for re-hydration. My question: How much salt needs to be dissolved in water such that it does not hydrate nor de-hydrate? For instance, would a physiologic saline solution (9 grams of salt per liter of water) meet this criterion?

If water has a low salt content, it hydrates us. When water has too high salt concentration, like sea water, it drains water out of us instead when we drink it. At what salt concentration would water leave us completely unaffected?


Is there module that can " Let users follow each others and be informed via mail in case of new items were added " ?

Is it possible to implement a Follow button for authors of posts in Drupal 7, so that users can:   Follow any one they wish, and Be notified about the new posts of those authors.   This sounds like 'Mashable Follow button' for authors.  Do you have any suggestions about how to implement this?


I am trying to draw individual image frames that when pieced together will to give the animation effect of a ball or circular object coming out of a thick (not necessarily sticky) substance or liquid. The idea is for a protruding object to form a circular object as it separates. How can I create these image frames using  illustrator?

I am trying to get an animation effect of a ball moving under a blanket with some resistance or a round object protuding out of a flat surface.  Below is what I've been able to do so far and what I want to achieve. For now I've used a different colour for the ball to make things a more visible.


Recently I've asked a question with a code mistake in C, and I received an answer that the goto statement can be harmful in certain situations. I'd like to know if it's a bad idea to use goto statements and why it's a bad idea.  I generally prefer using goto instead of the rest of the loops because it's generally easier and has never failed me so far. I've been using goto statements for a while in my programs to make them repeat themselves from certain points to help me with debugging, without having to re-open my program many times.   So basically, is the goto statement bad to use? If so, why? What can it do bad exactly?

Everyone is aware of Dijkstra's  (also  .html transcript and  .pdf) and there has been a formidable push since that time to eschew the goto statement whenever possible. While it's possible to use goto to produce unmaintainable, sprawling code, it nevertheless remains in . Even the advanced  control structure in Scheme can be described as a sophisticated goto.  What circumstances warrant the use of goto? When is it best to avoid?  As a followup question: C provides a pair of functions, setjmp and longjmp, that provide the ability to goto not just within the current stack frame but within any of the calling frames. Should these be considered as dangerous as goto? More dangerous?    Dijkstra himself regretted that title, for which he was not responsible. At the end of  (also  .pdf) he wrote:     Finally a short story for the record.   In 1968, the Communications of the ACM   published a text of mine under the   title "The goto statement considered   harmful", which in later years would   be most frequently referenced,   regrettably, however, often by authors   who had seen no more of it than its   title, which became a cornerstone of   my fame by becoming a template: we   would see all sorts of articles under   the title "X considered harmful" for   almost any X, including one titled   "Dijkstra considered harmful". But   what had happened? I had submitted a   paper under the title "A case against   the goto statement", which, in order   to speed up its publication, the   editor had changed into a "letter to   the Editor", and in the process he had   given it a new title of his own   invention! The editor was Niklaus   Wirth.   A well thought out classic paper about this topic, to be matched to that of Dijkstra, is , by Donald E. Knuth. Reading both helps to reestablish context and a non-dogmatic understanding of the subject. In this paper, Dijkstra's opinion on this case is reported and is even more strong:     Donald E. Knuth: I believe that by presenting such a   view I am not in fact disagreeing   sharply with Dijkstra's ideas, since   he recently wrote the following:   "Please don't fall into the trap of   believing that I am terribly   dogmatical about [the go to   statement]. I have the uncomfortable   feeling that others are making a   religion out of it, as if the   conceptual problems of programming   could be solved by a single trick, by   a simple form of coding discipline!"


So my question is: why alternating current produces electromagnetic waves?   There are plenty of answers on google that state it as fact, but none answer why. I  mean what is it about accelerating electrons that generate EM wave? Are the theories for it? Is there lazy explanation?

Let's consider it case by case:  Case 1: Charged particle is at rest. It has an electric field around it. No problem. That is its property.  Case 2: Charged particle started moving (it's accelerating). We were told that it starts radiating EM radiation. Why? What happened to it? What made it do this?  Follow up question: Suppose a charged particle is placed in uniform electric field. It accelerates because of electric force it experiences. Then work done by the electric field should not be equal to change in its kinetic energy, right? It should be equal to change in K.E + energy it has radiated in the form of EM Waves. But then, why don't we take energy radiated into consideration when solving problems? (I'm tutoring grade 12 students. I never encountered a problem in which energy radiated is considered.)


On MS SQL Server 2008, how do I make a select statement, that joins two tables, and return the content of table 2 as a comma-separated list?  Example: Table 1 contains all my orders, and table 2 my order lines. I want to select all fields from orders, as well as a comma separated list of all fields from the corresponding order lines, with each order line separated by semicolon (or something else).  So something like this:  | Orders.custno | Orders.name | Orders.email     | Orders.phone | Order lines                                                         | |---------------|-------------|------------------|--------------|---------------------------------------------------------------------| | 123456        | Dave        | dave@example.com | 1234567890   | “112233”,”Running shoes”,”495.00”;”223344”,”Roller blades”,”699.00” |   Hope this makes sense.  Thanks.

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


So, I tried  /summon spider 100 20 100 {Health:16.0f}{CustomName:Webby} then evreything that I could put in the middle with commas and full stops but it won't work, it'll let me use only one data tag but I am making a map that requires several of them for each mob. Obviously I am using Command Blocks in 1.12.2.  Thank you.

I have two commands I'd like to combine into one, but I'm not sure how to go about combining them. Is this possible?   Here are the commands. They work individually, I just can't seem to get them to work together:  /give @p jukebox 1 0 {CanPlaceOn:["minecraft:melon_block"]}     /give @p jukebox 1 0 {display:{Name:"Box"}}   Can you help me to add one of the commands to the other one?


I am training a CNN and it seems no that matter what I do my validation loss is always much greater than my training loss. To my understanding, this should mean my model is always overfitting my data set. INFORMATION: My model is built in Keras running on tensorflow=1.14. My model is a binary cross-entropy. I Have a data set of about 2500 tagged photos. My tensor board:

I'm training a neural network and the training loss decreases, but the validation loss doesn't, or it decreases much less than what I would expect, based on references or experiments with very similar architectures and data. How can I fix this?    As for question        to which this question is inspired, the question is intentionally left general so that other questions about how to reduce the generalization error of a neural network down to a level which has been proved to be attainable, can be closed as duplicates of this one.  See also dedicated thread on Meta:


I never quite understood why negative feedback is more used than positive feedback.   Using feedback makes it possible to adjust the gain, and thereby specify how much the input should be amplified.   But why is negative feedback more commonly used when we want to amplify small voltages from sensor readings such as photodiodes etc.   The output of the op-amp becomes the negative amplified value of the input (input and output has different polarity), which don't make sense why it should be useful..    Hence would i always use positive feedback, but I can see that the internet disagrees with me, so must be wrong somewhere in my "reasoning" so what am I doing wrong?

We are teaching op amps in a high school class, before calculus.  So we can't use control theory to teach how op amps respond.  All the same, I would like to have an intuitive explanation for how a feedback circuit works.  Take the negative feedback, for instance.  Is there a clear way to show how an initial difference of delta between V+ and V- leads to a very large (G(V+ - V-)) difference in the output, which then leads to ...  I'd like to be able to take that argument and show how the voltage of the output converges in addition to the standard virtual short argument.  Can anyone explain it clearly?


Are these schemes fundamentally different? Are other schemes fundamentally different in the sense that you can do different operations with them (or the same operations, but needing different primitives)?  For instance, Whit Diffie is on record as saying that he originally much preferred RSA because it provided signatures (at the time, things like ElGamal etc were not invented so RSA seemed superior).  RSA is often used as “key transport”, which seems like something Diffie-Hellman cannot do? But in a sense you can do it: Merely compute $k=g^{ab}$ and use $k$ and some symmetric cipher to “transport” your session key $k_s$? This requires the use of a symmetric cipher, whereas RSA key transport does not. Maybe there are other ways of doing it that only require the same primitives as RSA?  In addition, DH schemes like ElGamal seem to all require randomness to produce signatures (I could be wrong?), whereas RSA does not (except for padding I suppose?), but RSA does seem to require a hash function (I could be wrong)? Are they fundamentally different?  So my question is, are there fundamentally different properties of certain public key encryption schemes? Especially RSA and DH?

Is the Diffie-Hellman key exchange the same as RSA?  Diffie Hellman allows key exchange on a observed wire – but so can RSA.  Alice and Bob want to exchange a key – Big brother is watching everything.   Bob makes an fresh RSA key pair and sends his public key to Alice. Alice makes a random session key and sends it to Bob encrypted with Bob's public key. Bob decrypts the session key with his private key.   Alice and Bob have exchanged a key despite the fact that anybody can observe all the traffic. The maths of RSA and Hiffie Hellman are remarkably similar, both involving modular exponentiation.  They both work because $(A*B)^C \bmod N$ can be done in two steps, i.e. by calculating $X = A^C \bmod N$ on one side of the transaction, and $X^B \bmod N$ on the other – this trick is the basis of both Hiffie Hellman and RSA. Which make me wonder: Are they really the same thing?  Can we algebraically prove that the correctness of RSA implies the correctness of Diffie-Hellman?


I know that we need to win 2 of 3 games to rank up, rigth? like form silver 2 to silver 1.  Is it possible to rank down? like silver 1 to silver 2? There any matches that we need to win to stay in that rank?

Is it possible to fall from Platinum to Gold and from Gold to Silver on season 5? Since in every season stuff like that change I would like to know. And if yes, how many games you need to lose in a row in order to get demoted?


Some directories are highlighted green in my ll list so that it becomes unreadable. How can I switch that off?    I tried to upload a screenshot, but it wont show it... I hope my question is still clear  So, I tried to change it following    I went through all the types in the list  di = directory fi = file ln = symbolic link pi = fifo file so = socket file bd = block (buffered) special file cd = character (unbuffered) special file or = symbolic link pointing to a non-existent file (orphan) mi = non-existent file pointed to by a symbolic link (visible when you type    ls -l) ex = file which is executable (ie. has 'x' set in permissions). *.rpm = files with the ending .rpm   but that type did not change. it actually is a directory. for some reasons there seem to be two styles for directories. one is just dark blue no background, the other one has the green background that makes it unreadable. the di option only changes the directories that are dark blue and readable. Ideally I would avoid having a solution that removes all highlighting like ll --color=none. I would prefer to just get rid of that background The unreadable directories have the signature drwxrwxrwx, while the readable ones have drwxr-xr-x

On my console the color for directories is such a blue, that it is hard to read on a dark background.  How can I change the color definitions for ls?


Many  around the internet is using "X-NginX-Proxy"  Nowhere can I find a proper description of its purpose or why one would use it, apart from that it relates to using nginx as a proxy?  Example:  server { listen 80;  server_name forum.example.org;  location / {     proxy_set_header X-Real-IP $remote_addr;     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;     proxy_set_header X-Forwarded-Proto $scheme;     proxy_set_header Host $http_host;     proxy_set_header X-NginX-Proxy true; ...

I am very new to nginx configuration. I want to use it set virtual hosts so that I can run different Node JS apps on different ports on the same server, but have them served at different subdomains. After some searching I found a post on stackoverflow and it works well for what I want to do. Amongst other things, the code involved the following location block  location / {                                                              │     proxy_set_header X-Real-IP $remote_addr;                              │     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;          │     proxy_set_header Host $http_host;                                     │     proxy_set_header X-NginX-Proxy true;                                  │                                                                           │     proxy_pass http://otherapp/;                                          │     proxy_redirect off;                                                   │ }   Now I wanted to understand what the script does. I looked at nginx docs and notes posted by various people, and understood a few things. It appears to me that what I want will probably work even if I remove all the proxy_set_header lines in the above code EXCEPT proxy_pass. I want to learn what the different fields in the above code are doing. Probably they are useful for some things that I don't realize at the moment. Is there a place which lists all the fields for proxy_set_header module and explains them?   Thank you.


I've searched around here and it seems I'm not alone with my frustration towards Griffith's explanation of degenerate perturbation theory. Right from the start, Griffiths claims that some perturbation $H'$ will split a degeneracy (assume 2-fold degeneracy) and if we 'turn off' the perturbation then the 'upper' and 'lower' state will be some mutually orthogonal linear combinations of the degenerate states $\psi_A$ and $\psi_B$. Where did this claim come from? Is this because the linear sum $c_1\psi_A+c_2\psi_B$ is also an eigenstate of the unperturbed Hamiltonian $H^0$?   My intuition so far is that we resort to linear sums because we can now have distinct wave functions to use in the first order correction $E_1^1=\langle \psi_A^0 |H'|\psi_A^0 \rangle$ or $E_1^1=\langle \psi_B^0 |H'|\psi_B^0 \rangle$; I guess it was unclear which wave function we must choose? Is this why Griffiths goes on to solve $H\psi^0=E^0\psi^0$ where $H=H'+H^0$ and $\psi^0=c_1\psi_A+c_2\psi_B$?   I found some more formal mathematical reasoning behind this. I can't understand the explanations as I don't have a very advanced understanding of linear algebra, but from what I get we are trying to change basis? Can I get some clarification on the mechanism and reasoning behind this?

I have for quite some time now tried to find a satisfactory answer to this, but I haven't yet. In perturbation theory, with small parameter $\lambda$, we expand the eigenstate as  $$| E \rangle=| E^{(0)} \rangle + \lambda | b \rangle + ...$$  Where $| E^{(0)} \rangle$ is an eigenstate of the unperturbed Hamiltonian. The problem is that when there is degeneracy, there is a choice of these eigenstates. I know the answer is that they are chosen to be eigenvectors of the perturbing Hamiltonian, but my question is why.


I'm not sure if my site was hacked or there's a server related error. My website was running fine ever since I published it, yesterday I visited it and it said connection refused. I informed my hosting provider and they told me to create a new database connection, when I open phpMyAdmin I get a strange error that says:  Warning in ./libraries/plugins/auth/AuthenticationCpanel.php#629 mysqli_connect(): (HY000/2002): Can't connect to local MySQL server  through socket '/var/lib/mysql/mysql.sock' (2)   When I try to ssh into my server I get the following errors:  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ The RSA host key for [wesocular.com]:60504 has changed, and the key for the corresponding IP address [46.105.40.12]:60504 is unknown. This could either mean that DNS SPOOFING is happening or the IP address for the host and its host key have changed at the same time. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the RSA key sent by the remote host is SHA256:EvplXyAHYO4nP4rmOtJ2j3wc4O04UMUWMvLi9ZpsVuU. Please contact your system administrator. Add correct host key in /c/Users/Game330/.ssh/known_hosts to get rid of this mes   sage. Offending RSA key in /c/Users/Game330/.ssh/known_hosts:1 RSA host key for [wesocular.com]:60504 has changed and you have requested strict    checking.   What could be the problem ?

I've been using ssh to log-in to a remote server I rent for several years. Last week I got a message from them saying they upgraded my account and server. Now when I go to login, I get this message from ssh  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ The RSA host key for mydomain.com has changed, and the key for the corresponding IP address X.X.X.X is unknown. This could either mean that DNS SPOOFING is happening or the IP address for the host and its host key have changed at the same time. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is XXxXXXXXXX Please contact your system administrator. Add correct host key in /home/myaccount/.ssh/known_hosts to get rid of this message. Offending key in /home/myaccount/.ssh/known_hosts:7 RSA host key for mydomain.com has changed and you have requested strict checking. Host key verification failed.   Now, I assume that this has been triggered by my host upgrading my server. So I want to trust this site again. But I can't quite see how.   I looked in known_hosts and all there are there are public-keys. But I can't tell which of these comes from the old version of this particular server. Nor do I know how to get a correct key for the host; the previous time I made contact, I think ssh just confirmed with me and automatically saved it. Now it says I've requested strict checking, but I have no idea when I did this or where to reset it.


I am visually impaired, and find it really difficult to locate the mouse pointer on screen. (I am running Ubuntu 16.04.3 LTS) Other OS's have built-in methods to make the mouse pointer more easily visible. In Windows you can turn on "pointer trails" where moving the pointer will  making it easier to visually track/follow the pointer. (I nicknamed them "mouse droppings" ;-) ) And in MacOS Sierra, Apple added a feature whereby if you jiggle the mouse pointer (move it back and forth rapidly) it will , again to make it easier to see on screen. Is there a similar feature (either built-in or provided by a third-party app) for Ubuntu?

In Windows, it is possible to set pressing Ctrl to display the current location of the mouse pointer, as per .  Is there a way of setting a key or key combination to perform the same action in Ubuntu? Note, this is the opposite of turning this function off, as detailed at .


I live in London and I have been issued a Schengen multiple entry Visa from The Italian Consulate from 18 Aug to 1 Oct. My Holiday to Italy is from 18Aug to 23 Aug. Thereafter I will return to London.   In september I want to visit other countries in Schengen Area like France, Switzerland etc. But this time I will not be going to Italy. Will this be a problem with Port of Entry?

My wife was just issued a multiple entry visa by France, which is good for one year.  Our first trip will be to France, the issuing country.  My question is: after we leave the EU and return, must future trips also start in France? Or may we go directly to (say) Greece from the US on a later visit?


I am running a perl script and basic addition operators seem to be not working. For my code  print $total_charges," 1 \n"; print $payments," payments\n"; $total_charges+=$payments; print $total_charges," 2 \n";   For this code, the output is the following  10192.19 1 -401.99 payments 9790.20000000005 2   If you do the math, this number would be correct except for the extra decimal places. What is going on?  I need these numbers to be accurate. Any suggestions on fixing this, or do I just truncate to 2 decimals each time?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I have this two example string, and I am building a regex for cover both [[CONTENT:Image|||23123123123|||urlClipping|||true]] [[CONTENT:Image|||23123123123|||urlClipping]]  I'm need to separate the inner params from the separators (|||) and the beginning and end ([[,]]) So far I've tried with \[{2}CONTENT:([^\|]*)\|{3}([^\]]*)\|{3}([^\]]*)(\|{3}([^\]]*))?\]{2}  And \[{2}CONTENT:([^\|]*)\|{3}([^\]]*)\|{3}([^\]]*)(?:\|{3}([^\]]*))?\]{2}  But both o them merges two params into one How can I fix this regex?

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


While running   gksu gedit /etc/udev/rules.d/somefile.rules   I am getting this suggestion.  Command 'gksu' not found, did you mean:    command 'gosu' from deb gosu   command 'ksu' from deb heimdal-clients   command 'ksu' from deb krb5-user  Try: sudo apt install <deb name>

I installed Ubuntu 17.10. Now I am having trouble with gksu:  $ gksu -dg synaptic No ask_pass set, using default! xauth: /tmp/libgksu-HgUjgQ/.Xauthority STARTUP_ID: gksu/synaptic/8760-0-alex-XPS-15-9530_TIME4974977 cmd[0]: /usr/bin/sudo cmd[1]: -H cmd[2]: -S cmd[3]: -p cmd[4]: GNOME_SUDO_PASS cmd[5]: -u cmd[6]: root cmd[7]: -- cmd[8]: synaptic buffer: -GNOME_SUDO_PASS- brute force GNOME_SUDO_PASS ended... Yeah, we're in... Unable to init server: Could not connect: Connection refused (synaptic:8767): Gtk-WARNING **: cannot open display: :1 xauth: /tmp/libgksu-HgUjgQ/.Xauthority xauth_env: (null) dir: /tmp/libgksu-HgUjgQ   If I don't use -g, the password dialog is disabled. So looks like a problem with creating a tty for root.  Any advice?


Can I install 64-bit Google Chrome on 32-bit Ubuntu 16.04? My computer has 504mb RAM. The software installer is not able to install Google Chrome 64-bit version.

I have 64 bit core i5 configuration I have installed ubuntu studio 11.04 (32 bit) on it.It's working fine but for eclipse android development it is not working what should I do? Should I download 64 bit eclipse or first I do have 64 bit studio OS and then install the rest development environment


I wrote :     English language learners (ELL) are likely to experience more difficulties as a result of problems in auditory discrimination of speech sounds.   But I feel it may sound better with     English language learners (ELL) are likely to experience more difficulties due to problems in auditory discrimination of speech sounds.   Am I right? As I found in this question  due to could be traditionally used as adjective, and here it may play the adjective role of difficulties. Is there any difference here?

According to the answer key of a SAT preparation book I'm studying, there is an error in the sentence     By the time the bank guard closed the doors, a riot had erupted due to the long lines and shortage of tellers.   and it should be changed to     By the time the bank guard closed the doors, a riot had erupted as a result of the long lines and shortage of tellers.   I disagree with this. Why is the first sentence unacceptable?


I'm trying to add fire and smoke to my scene. I decided to use QuickEffects > QuickSmoke, and then change the flow type to Fire + Smoke on my emitter. It seems that both the fire and smoke appear in the scene view, however only the smoke appears in the render. (using Cycles)  Scene view:    Render:    (the smoke is a bit hard to see on the black background)  If required, I can share the settings of the smoke emitter and the smoke domain.  Thanks in advance.

I am trying to make an explosion in Blender.  I am having a problem with the smoke simulation with the Cycles rendering engine. More specifically, I have been able to render smoke, but flames do not show up. In the viewport however, everything looks perfectly fine.  The render looks like this:    But in the viewport, it is clear that there are flames. Does anyone have any idea what is going on?     This is NOT a duplicate of  because I have Flame Rate set to 1.0


Is it possible to check out a single file from an SVN repository using ?  I have code to checkout a complete directory. But I need only a specific file to be checked out.

"It is not possible to check out a single file. The finest level of checkouts you can do is at the directory level."  How do I get around this issue when using Subversion?  We have this folder in Subversion where we keep all our images. I just want to check out one file (image) from that. This folder is really big and has ton of other stuff which I don't need now.


I was thinking of using Spell damage to knockdown a dead Tree trunk in order for it to land on two/three skeletons and therefore pinning them effectively in place.  Assuming having 1 Torch lit only with an all-human party (and I am Chaotic Evil), I was thinking of aiming my spell on the Torch effectively putting it out and make my quick getaway.   Are these possible scenarios?

During a fight in a semi-flooded room, one of my players wanted to use Shocking Grasp on the water:     Lightning springs from your hand to deliver a shock to a creature you try to touch. Make a melee spell attack...On a hit, the target takes 1d8 lightning damage, and it can’t take reactions until the start of its next turn.   Wanting to reward him for a creative use of the spell, I allowed it, using an attack roll of AC 10 and hitting all creatures within 10ft of the spot (including caster).  Is there any rule for these situations? I want to reward creativity without unbalancing spells that are meant for single-target use.


For example, take the sentence: "Gaussians are widely used in mathematics & statistics". At this point there probably tens of thousands of papers that use Gaussian functions in some way (that's not even counting the papers in other fields like the social sciences that make use of Gaussians). It's impractical to cite them all. The sentence still calls for at least some citations though. How does one choose which papers to cite?

I am an undergraduate student with no experience at all.  If you are writing a research paper, that you are planning to submit for publication, how do you state that a particular statement/fact is commonly known to all and it's dicoverer/inventor is not known, and that there exists no research paper that introduced the concept but there do exist various books/websites that discuss the very concepts and a few derivatives of the concept?  I am not able to cite a particular statement/bunch of statements as I am not able to find any research paper related to that at all.  The particular thing in question is:   What should I do?


The description Einstein gave us about gravity, describes gravity from the perspective of the particle, where it "feels" movement. Instead from that perspective the particle can say space-time it's self is curved and is just following a geodesic trajectory. However, if you want to take space time to be flat, because there is no gravitational force affecting you, is it possible to represent Einstein's field equations as a vector field? Possibly using the geodesic equation?  Even fictitious forces can be described as forces and both the stationary frame and the accelerated frame give the same result of where the ball ends up relative to them? This fictitious force field would need to be approximately equal to Newton's gravitational law at slow speeds, but needs to be relativistic in general. This would need to be described as a four force.  If this field can be constructed from the geodesic equation, what would the acceleration field look like as a four-vector?  If we assume a Schwarzschild metric:  $$ds^2 = - (1-\frac{r_s}{r})c^2 dt^2 + \frac{1}{1-\frac{r_s}{r}} + r^2 d\Omega^2, $$  And substitute the metric into the geodesic equation: $$ {d^2 x^\mu \over d\tau^2} =- \Gamma^\mu {}_{\alpha \beta}{d x^\alpha \over d\tau}{d x^\beta \over d\tau}, $$   Is it possible to get into the form:  $$ {d^2 x^\mu \over d\tau^2} = F(x^\mu)~? $$

Can general relativity be completely described as a field in a flat space? Can it be done already now or requires advances in quantum gravity?


I see lots of articles about preventing a specific computer from writing to a USB flash drive or preventing malware from getting from a USB flash drive to a computer; what I can’t find anything for is how to prevent any system from writing to a USB flash drive.   I work at an I.T. help desk and as such I work with some devices that have some form of malware. From simple adware, to more advanced kinds of infections it varies. I have a USB flash drive with a bunch of tools I use day to day to fix some of the more common issues. I want to lock this USB flash drive down and prevent it from being modified. I know some viruses will try to infect a USB device, and this is exactly what I want to avoid. I don’t want to use a USB flash drive on one users computer and then plug it into the next ones and infect them.   Is there an effective method—that is OS independent—to prevent a USB flash drive from being written to? I could use a disc to do this, and use a USB powered disc drive where optical drives are not present in the laptop, however this is not as convenient of a method, so I’d prefer to use a USB flash drive if possible.

I'm looking for a solution to write-protect the contents of a USB key. The idea is to prevent its contents from being inadvertently removed by the user or changed by malicious programs -- not to restrict the re-cycling of the key for something else.  Here is a summary of my findings so far:   Some keys have a switch which makes them read-only. Unfortunately this is not always the case.  With a FAT32 filesystem the only solution seems to be setting the files "read-only". But this protection is too weak. There is a slightly stronger write-protection available for NTFS, which can be achieved by removing write privileges from "All Users" it will make the files read-only to every account, except "Administrator". Formatting the disk as UDF makes it read-only under Windows XP SP3, but read-write in Windows Vista, Windows 7, Linux and Mac OS X. Formatting as ISO9660/CDFS makes it read-only under Linux and Mac OS X, but unfortunately the contents are not readable anymore from Windows. With microcontroller-specific software is possible (if supported by the chip) to re-partition the key so it displays for example a write-protected and a read-write partition. The problem is that it is very confusing for the users: the write-protected partition can appear as a CD-ROM drive (which it is not), after insertion some drivers are apparently installed on the computer (in fact they are not really drivers), and it can lead to prompting for reboot. Besides, this solution cannot be applied universally because it requires knowing which chip is used in the drive, and the existence of publicly available tools to re-program the device.  John Reasor mentions utilities able to fill all free space on the device, making it impossible to create new files (see below).   Does there exist a general solution to store non-modifiable contents on a USB key?   It protects the contents from modifications typically done from the shell (e.g. delete, rename, move) or from the files and folders being modified by a standard applications (e.g. save-as) It should work with most of the devices The user can still re-format the device into a regular key to re-cycle it for another usage (for example, with )


I have an ajax call that will take long to complete (minutes). During the execution a spinner will be displayed (triggered with AjaxStart and AjaxStop).  What I'd like to do is to add a counter of the progress in the ajax call (something like "X records out of 1000 processed so far" with X updating with a second ajax call). The second ajax call will run with a setInterval every 10 seconds. My question is: how to stop setInterval when the first ajax call has completed? This is the first ajax call:  function ajax_submit(){     var submit_val=$("#stato").serialize();     dest="plan/new_bp1.php";     $.ajax({         type: "POST",         url: dest,         data: submit_val,         success: function(data){              data1=data.split("|");             if(data1[0]=="Successo"){                  $("#spnmsg").fadeTo(200,0.1,                     function(){$(this).removeClass().addClass("spn_success").html(data1[1]).fadeTo(900,1)});                 }else if(data1[0]=="Errore"){                     $("#spnmsg").fadeTo(200,0.1,                     function(){$(this).removeClass().addClass("spn_error").html(data1[1]).fadeTo(900,1)});                   }         },         complete: function(){             setTimeout(function(){ $('.container').load('plan/home.php');},2000);          }     });     setTimeout(function(){counterUpdater();},2000); }   In the end I just call counterUpdater() (waiting a couple of seconds while the counter of all the records to be processed gets updated).  function counterUpdater(){     setInterval(ajax_counter_upload(),10000);    }  function ajax_counter_upload(){     //all the stuffs to get the updated count of processed records }   How can I stop counter_updater() from running each ten seconds when ajax_submit has comlpleted? What do I have to put in success or complete function?  EDIT: I am aware of how to call clearInterval but in this specific case the intervalID will be in the counterUpdater scope only. So how to move it back to ajax_submit?

I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?   I want the user to be able to stop the repeated refresh of data.


It's obvious that $\dfrac{d(x^x)}{dx}=x^x (1+\ln x)$, then what about its integral? Special functions can be used if this integral can't be evaluated with simple functions, e.g. Gamma function $\Gamma(x)$ or Lambert W-function $W(x)$.  Thanks.

I'm trying to find $\int x^x \, dx$, but the only thing I know how to do is this:  Let $u=x^x$.  $$\begin{align} \int x^x \, dx&=\int u \, du\\[6pt] &=\frac{u^2}{2}\\[6pt] &=\dfrac{\left(x^x\right)^2}{2}\\[6pt] &=\frac{x^{2x}}{2} \end{align}$$  But it's certain that this isn't the correct way to evaluate that, and the answer must be wrong.


I started playing on Playstation 4. I created my home and many other things. I do not want to do it again.

I'm mostly wondering if there any way to port or convert minecraft ps4 saves into a format that is compatible with pc minecraft. I only own a ps4 and a pc, but I'm still curious if it's possible to do the same for xbox. Also, are there any legal reasons not to convert files from one platform to another?


The question asks to prove that  $$\|v\|_{1}\|v\|_\infty \leq \frac{1+\sqrt{n}}{2}\|v\|^2_2.$$  I have shown that $\|v\|_1\|v\|_\infty \leq  \sqrt n \|v\|_2 \|v\|_\infty = \sqrt n \|v\|_2^2 \frac{\|v\|_\infty}{\|v\|_2} \leq \sqrt n \|v\|_2^2 $. However, this is not as tight as the desired form. Could someone provide a hint or an answer?

I know that $\|v\|_1\|v\|_\infty \leq (1+\sqrt{n})\|v\|_2^2$, but cannot find a way to refine this bound. Does anyone know where would be a good place to start? Trying out several cases seems to imply that the inequality is true.


Let U, V and W be i.i.d. random variables with uniform distribution on [0,1]. Find the distribution of (U*V)^W.  I tried conditioning on the values of V and W to get a double integral over the unit square but I ended up having to integrate 1/v from 0 to 1 which is clearly wrong.

$X,Y$ and $Z$ are independent uniformly distributed on $[0,1]$  How is random variable $(XY)^Z$ distributed?  I had an idea to logarithm this and use convolution integral for the sum, but I'm not sure it's possible.


Let's suppose I have a base class B: struct B {     virtual void f(); };  and a class derived from B called D: struct D : B {     void f() override; };  Is there anyway to call B::f from within D::f ? void D::f() {    call B's implementation of f  // <-- ???    do other stuff }

Say I have classes Foo and Bar set up like this:  class Foo { public:     int x;      virtual void printStuff()     {         std::cout << x << std::endl;     } };  class Bar : public Foo { public:     int y;      void printStuff()     {         // I would like to call Foo.printStuff() here...         std::cout << y << std::endl;     } };   As annotated in the code, I'd like to be able to call the base class's function that I'm overriding. In Java there's the super.funcname() syntax. Is this possible in C++?


In QGIS Python console, how can I calculate the location of a final point, given a distance and bearing from an initial point? In PostGis I see that it is ST_Project, however I would like to do it with the QGIS python functionality.  In Postgis I used this:   SELECT utrancellid, azimuth, ST_MakePoint(longitude,latitude), ST_MakePolygon( ST_MakeLine( ARRAY[ ST_AsText(ST_MakePoint(longitude,latitude)), ST_AsText(ST_Project(ST_MakePoint(longitude,latitude)::geography, 100, radians((azimuth-30+360)%360))), ST_AsText(ST_Project(ST_MakePoint(longitude,latitude)::geography, 100, radians((azimuth+30)%360))), ST_AsText(ST_MakePoint(longitude,latitude)) ])) FROM sector_location_csv;     As you can see, ST_Project is a closed function, and was looking for something similar in QGIS, as I want to avoid trigonometric functions.

I am plotting witness tree data to calculate pre-settlement tree density. I have a shapefile with points along section lines (square miles) at each half mile. I am making another table that contains tree data - distance, bearing, and diameter - related by survey point to the existing shapefile attribute table. Is there a way to create points on the map for the trees based on the distance and bearing from each survey point?   I'm not necessarily asking for a detailed set of instructions (although if anyone wishes to, I'd be grateful) but rather just if it's possible and a couple key words to continue searching how to do it.


My notebook was shut down and entered automatic repair. But when it loaded it requested an administrator account, which it resolved it was non existent. Nevertheless I had already registered and activated an administrator account using the following command:  net user administrator /active:yes  I guess it should turn the admin on, but it didn't. Does anyone know how can I login and repair my Windows?

I accidentally disabled my admin account.  After I login to another account I found I can not get admin rights, because all admin accounts on my computer are disabled.  I clicked on 'run as administrator' but only see a smart card choice (all the admin accounts are disabled so no choice provided)    I don't want to re-install my OS, help!    Details:  I have account A on my computer.    I got a new computer so I want to give the old one to my mother.    Creating a new user account B for her and disable account A.    Logout and restart.    Successfully login B, now I found I could not get admin rights because no account choice is provided.    More informations about my machine:  OS is Windows 10 and my admin account is a Microsoft Account.  I have an arch-linux installed on my computer and dual-boot it using GRUB, so maybe I can not use safe mode.


Using Drupal 7.61 and Drupal Commerce 7.x-1.14 (+ Commerce Shipping 7.x-2.3 and Flat Rate 7.x-1.0-beta2)  My client has (probably) deleted the shipping line item for an order and he has tried to edit this order to add a new shipping line item (4 shipping services set by Flat rate).  We get the same AJAX error each time we try :   DatabaseTransactionOutOfOrderException: in DatabaseConnection->rollback()(line 1094 of /home/my_website/public_html/includes/database/database.inc).  Where should I look to fix this issue?  First there was also a Rules issue and I managed to fix it with a specific condition but we still can not edit the order to add a shipping line item.  EDIT : after a couple of new tries, it seems like the Rules Collect rate : flat rates fired and failed somewhere... some values are missing when adding a shipping line item through Order edit form, compared to Checkout where everything goes well   EDIT/ANSWER : Thanks to Clive's comments, I found a solution. Actually, multiple savepoints were involved in my process (one to save the new shipping line item in Drupal database and an another one to send it in an external database through a specific Rule). That makes sense when you read documentation on rollback(). So I have changed my Rule with a special condition related to shipping and now it works.

I am working on plugin to Drupal Commerce, and I started getting this error:   DatabaseTransactionOutOfOrderException: in DatabaseConnection->rollback() (line 1058 of /Library/WebServer/Documents/includes/database/database.inc).   Can anyone shed some light on what this error means? If I install a fresh drupal and reinstall my plugin, is that likely to clear things up?   Any advice?   Thanks!


I have to create hundreds of DOM elements for my Electron-based app using JavaScript, and I have found multiple ways of doing that.  I would like to know which one is considered 'standard' or 'most efficient' in terms of design and performance;    While trying to find an answer, I have found the use of   - jQuery:  $('body').html($('
', {class: 'spinner'}));  - JS' createElement:   var element = document.createElement("p");  document.body.appendChild(element);   - JS' innerHTML:  var element = "
hello world
"; document.body.innerHTML += element;   - JS Libraries such as MooTools    Is this choice personal?  Should performance not be considered a problem?   Thank you,

Recently I've been doing a lot of modal window pop-ups and what not, for which I used jQuery. The method that I used to create the new elements on the page has overwhelmingly been along the lines of:   $("

");   However, I'm getting the feeling that this isn't the best or the most efficient method of doing this. What is the best way to create elements in jQuery from a performance perspective?   has the benchmarks to the suggestions below.


I am installing doxygen using    sudo apt-get install doxygen   but getting following unmet dependencies. I tried with google but not getting proper solution for same.  I am getting this while run above code:  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:  doxygen : Depends: libclang1-3.6 (>= 3.2) but it is not going to be installed E: Unable to correct problems, you have held broken packages.   I am also tried with sudo apt-get install -f but no solution.

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


How to make following code completely generic?  Why I'm not allowed to write:  private E[]store = new E[length];  import java.util.Arrays; public class MyArrayList<E> {     private int size = 0;     private int length = 10;      private Object [] store = new Object[length];         public E get(int index){         return (E)store[index];     }      public void add(E item){         if(size >= store.length -5){             increment(store);         }         store[size++] = item;     }      private <T> void increment(T[] store2) {         store = Arrays.copyOf(store2, store2.length * 2);     }      public int size(){         return size;     } }

Due to the implementation of Java generics, you can't have code like this:   public class GenSet<E> {     private E a[];      public GenSet() {         a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation     } }   How can I implement this while maintaining type safety?  I saw a solution on the Java forums that goes like this:  import java.lang.reflect.Array;  class Stack<T> {     public Stack(Class<T> clazz, int capacity) {         array = (T[])Array.newInstance(clazz, capacity);     }      private final T[] array; }   But I really don't get what's going on.


I have this very simple code. I am trying to figure out how I can simultaneously alter the object reference in the array with the object reference that was first placed into the array. I want to know how to bind the two references/values.  In JavaScript, which is very similar to Java in terms of passing by value, the best we probably can do is to use Object.observe() like so:   but with Java, I wonder if there is a good way to do this without writing your own library?   public class ArrayRefVal {      public static void main(String[] args) {         ArrayList<Object> al = new ArrayList<Object>();         Object s = new Object();         al.add(s);         s = null;         System.out.println(al.get(0));     } }   likewise:  public class ArrayRefVal {      public static void main(String[] args) {         ArrayList<Object> al = new ArrayList<Object>();         Object s = new Object();         al.add(s);         al.set(0, null);         System.out.println(s);     } }   turns out JavaScript has the same behavior as Java on this one. How can I somehow bind the element in the array with the object s, such that when I change the element in the array it changes the original object?  Did I mention this already? I want to know how to bind the two references/values.

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Have we practically measured the distances between the variations of electromagnetic radiations in space in nanometers or is it just theoritical because of calculations?  Also the one who have marked duplicate i didn't understand the answer so please anyone who can answer please explain in simple language as well as less mathematical notions.

I'm sure this is a trivial question for someone who knows something about electromagnetic radiation, but: how do experimenters measure the wavelength/frequency of light? For example, how do we know that red light has $650-700~\text{nm}$ wavelength?


I have $GF(2^3)$ generated by $\Pi_1(\alpha)=x^3+x+1$ and $GF(2^3)$ generated by $\Pi_2(\alpha)=x^3+x^2+1$.  $\bullet$ $\Pi_1(\alpha)=x^3+x+1$ $000=0, 100=1,010=\alpha,001=\alpha^2,110=\alpha^3, 011=\alpha^4,111=\alpha^5,101=\alpha^6$  $\bullet$ $\Pi_2(\alpha)=x^3+x^2+1$ $000=0, 100=1,010=\lambda,001=\lambda^2,101=\lambda^3, 111=\lambda^4,110=\lambda^5,011=\lambda^6$  The exampla say that $\alpha$ and $\lambda^3$ both have minimal polynomial $\Pi_1$ and thus $\alpha \iff \lambda^3$ form an isomorphism between the two version.   How can I see in a practical way this fact? Someone can explain me this concept?

Let $\alpha$ be a root of $x^3 + x + 1 \in \mathbb{Z}_2[x]$ and $\beta$ a root of $x^3 + x^2 + 1 \in \mathbb{Z}_2[x]$. Then we know that $$\mathbb{Z}_2(\alpha) \simeq  \frac{\mathbb{Z}_2[x]}{(x^3 + x + 1)} \simeq \mathbb{F}_8 \simeq \frac{\mathbb{Z}_2[x]}{(x^3 + x^2 + 1)} \simeq \mathbb{Z}_2(\beta). $$   I need to find an explicit isomorphism $\mathbb{Z}_2(\alpha) \to \mathbb{Z}_2(\beta). $   I was thinking of finding a basis for $\mathbb{Z}_2(\alpha)$ and $\mathbb{Z}_2(\beta)$ over $\mathbb{Z}_2$.   I let $\left\{1, \alpha, \alpha^2\right\}$ and $\left\{1, \beta, \beta^2\right\}$ be these two bases. Now suppose I have a field morphism $$ \phi: \mathbb{Z}_2(\alpha) \to \mathbb{Z}_2(\beta) $$ which maps $1$ to $1$. how can I show that the image of $\alpha$, i.e. $\phi(\alpha)$, completely determines this map?


Sometimes internal harddrives are available as /dev/sda (with subsequent media located in /dev/sdb etc), and other times available as /dev/hda. What is the difference between the two?  Does it vary between Linux distributions, or is it based on the computer hardware, or perhaps the harddrive type?

Assume that we have two disks, one master SATA and one master ATA. How will they show up in /dev?


I want to expose my API to an external system, and I want to authenticate the user by only username and password. I don't want to use username password OAuth flow while authenticating the user. Can we achieve this?

I feel like this should be really easy to do, but I can't find anything about it on the web. Is there a way, through either javascript or a java web servlet, to skip the subsequent authentication?  We are trying to use the REST Api in production, but the problem is, that each time you refresh the page in javascript, or delete the cookies in java, you have to login again to salesforce.  Is there some way to do an ajax call or the login in the background or whatever, so that you can have your application connecting to salesforce right away?


I created a "Dynamic" VeraCrypt container of size 10 GB, i.e. it will grow when the usage needs it. As it's initally empty, in reality it takes less than 100 MB on disk. Why does it still take a few minutes to copy with Windows Explorer to an external USB HDD (normal time for 10 GB with my USB2 device), rather than a few seconds, as the file in reality takes less than 100 MB? Why does it copy the full 10 GB whereas only < 100 MB are used?

How can I copy or move a sparse file from one NTFS volume to another NTFS volume while maintaining the sparseness using the native tools included with Windows?  If there is no way to do this with the native tools, then what is a free application from a trusted vendor that will do this?  Surely there is a command prompt command or powershell command that will do this.  I have a file that represents 250GiB that is taking up 20GiB of disk space and I would like it to continue only taking up 20GiB when I move it.  Thanks.


Trying to plot the sin(x) function, I get this result:    The MWE is here:  \documentclass{standalone} \usepackage{ pgfplots} \begin{document} \begin{tikzpicture} \begin{axis} \addplot[samples=500]{sin(x)}; \end{axis} \end{tikzpicture} \end{document}   cos(x) looks like an inverted parabola and tan looks just like sin.  I'm using pdflatex and MiKTeX. Any ideas?

I know that the equations (t-sin t, 1-cos t) define a cycloid that looks like this:   However the code  \begin{tikzpicture} \begin{axis}[title={Ciklois}, no markers] \addplot[variable=\t, domain=0:360] ({t-sin(t)}, {1-cos(t)}); \end{axis} \end{tikzpicture}   gives me this:    What's the problem? I know that gnuplot may help me out here, but I don't want to install it unless really necessary.


Evaluation of $$\int^{1}_{0}\frac{\ln^2(1+x)}{x}dx$$   $\bf{My\; Try::}$ Let $$I = \int^{1}_{0}\frac{\ln^2(1+x)}{x}dx = \int^{1}_{0}\ln^2(1+x)\cdot\frac{1}{x}dx$$  Using By parts, We get  $$I = \left[\ln^2(1+x)\cdot \ln(x)\right]^{1}_{0}-2\int^{1}_{0}\frac{\ln(1+x)\cdot \ln x}{1+x}dx$$  So we get $$I = -2\int^{1}_{0}\frac{\ln(1+x)\cdot \ln x}{1+x}dx$$  Now how can i solve above Integral , Help required, Thanks

The definite integral  $$\int_0^1\frac{\log^2(1+x)}x\mathrm dx=\frac{\zeta(3)}4$$  arose in my answer to . I couldn't find it treated anywhere online. I eventually found two ways to evaluate the integral, and I'm posting them as answers, but they both seem like a complicated detour for a simple result, so I'm posting this question not only to record my answers but also to ask whether there's a more elegant derivation of the result.  Note that either using the method described in  or substituting the power series for $\log(1+x)$ and using  $$\frac1k\frac1{s-k}=\frac1s\left(\frac1k+\frac1{s-k}\right)\;$$  yields  $$ \int_0^1\frac{\log^2(1+x)}x\mathrm dx=2\sum_{n=1}^\infty\frac{(-1)^{n+1}H_n}{(n+1)^2}\;. $$  However, since the corresponding identity without the alternating sign is used to obtain the sum by evaluating the integral and not vice versa, I'm not sure that this constitutes progress.


Background  Pinning applications to the taskbar is working fine. When you right-click on a taskbar icon, you see recently-opened and pinned files and folders (e.g. I have Downloads pinned to the File Explorer taskbar icon)  The Problem  Clicking on one of these recent or pinned items should open it, but nothing happens when I click it. Clicking the taskbar icon does open the program.  What I've Tried:   Removing the pinned item, re-opening it, and re-pinning the recent file Recent items and pinned items 8 different taskbar icons, both pinned and recent items

So I have the latest version of Windows 10, and this is a new PC.  File Explorer is in the taskbar.  When I open the context menu (right-click) on it, I get the list of folders as seen in the picture.  When I right click on any of them, I get the blank black box you see in the picture.  If I click on any of the folders, such as Downloads or Update.  Nothing happens.  They don't open.  The only way to use it is to click on the actual File Explorer icon and then navigate from there.  I've tried uninstalling things (not that I have much installed since it's a fresh install) and I've tried scans, etc.  This only happens with File Explorer.  Everything else works fine.  I can't figure it out.


In quantum mechanics complex numbers are absolutely essential because of the relation $$[\hat q_i,\hat p_j]=i\hbar\delta_{ij}.$$ But is complex number also essential anywhere in the formalism of classical physics, except for some convenience of mathematical calculations? Is there any example from classical physics where there is no other way out except to introduce complex variables? Is there any strong reason by which I can say that  complex number are unavoidable in classical physics too?

The use of imaginary and complex values comes up in many physics and engineering derivations. I have a question about that: Is the use of complex numbers simply to make the process of derivation easier, or is it an essential ingredient, without which it would be impossible to derive some results?   I can identify two different settings where the answer may be different:   It doesn't look like it is mandatory for results in Newtonian mechanics, General Relativity and classical electrodynamics. Can we say the same thing about quantum mechanics either way for sure?   Could this be a difference in quantum mechanics over the classical picture?


What I'm trying to do is encrypt 16 byte packets of data using the 128 bit AES-CBC encryption provided by SubtleCrypto.encrypt() in a web browser.  What I expected to find was 16 bytes of encrypted data for 16 bytes of input.  What I actually find is 32 bytes of encrypted data for 16 bytes of input.  Specifically, 15 bytes of input produces 16 bytes of output, 16 bytes of input produces 32 bytes of output, and 17 bytes of data produces 32 bytes of output.  My question is, why does 16 bytes of input data produce 32 bytes of output?  I would have suspected that this might happen only with > 16 bytes of input data, not >= 16 bytes.  Save the following test code to a file and open with a web browser.     <title>WebCrypto encrypt test</title>
See console log.

I'm trying to understand the SSL Poodle Attack and I'm wondering why the last block of a CBC Record can be full of padding? Wouldn't that mean that the useful data was already a multiple of the key size?  Maybe I'm misunderstanding something else here, as it would seem like you can pad by any number of full blocks of padding. Just don't see why an SSL Library would do that.  Thanks!


I'm trying to change the height of a textarea according to its scrollheight.   This works fine the first time i change the height however i got to a scenario where it doesn't work for me, I've made jsFiddle to show what i'm doing and what's going wrong.  Step by step explanation of jsfiddle scenario:  1: Click button1 and check the current scrollheight.  2: Click button3 and then button1 and notice that the scrollheight value has decreased.  3: Click button2 and then button1 and notice that the scrollheight value is back again.  You can switch back and forth between width 50 and 100 before you continue and check its scrollheight, it will change all the time. Now what happens when we continue is what's going wrong for me.   4: Make sure width is 50% by clicking button2 then Click button4 and notice that the textarea height has increased.  5: Click button1 and check its current scrollheight.  6: Now click button3 to change it's width to 100%  7: Click button1 and notice that the scrollheight is still the same even tho we just changed its width from 50% to 100% ??  As you can see here the scrollheight is no longer changing, and not the textarea height either, even though i changed the textarea width, Anyone know why this is happening? Any help or input is highly appreciated, thanks!   $("#b1").click(function(){     var textaraElement =document.getElementById("TextArea");     alert(textaraElement.scrollHeight); });

There was , which I've tried. But there is one problem: the textarea doesn't shrink if you delete the content. I can't find any way to shrink it to the correct size - the clientHeight value comes back as the full size of the textarea, not its contents.  The code from that page is below:  function FitToContent(id, maxHeight) {    var text = id && id.style ? id : document.getElementById(id);    if ( !text )       return;     var adjustedHeight = text.clientHeight;    if ( !maxHeight || maxHeight > adjustedHeight )    {       adjustedHeight = Math.max(text.scrollHeight, adjustedHeight);       if ( maxHeight )          adjustedHeight = Math.min(maxHeight, adjustedHeight);       if ( adjustedHeight > text.clientHeight )          text.style.height = adjustedHeight + "px";    } }  window.onload = function() {     document.getElementById("ta").onkeyup = function() {       FitToContent( this, 500 )     }; }


I'm trying to create my first 3d model with material . so i pick up my radio to be my guide . There is a problem that i cant solve . i tried to create a grid in front of the radio but when i render it for testing i cant see that grid    and im not sure i did the right way to create this grid . I just use plane and then subdivide it 10 time twice ! and then use wireframe modifier to create tiny hold in the grid  AM i doing it right ? Plz give me some advice Thx you :)

I have a model which you can see here (camera perspective).    In the second image, you can see how the render turned out.    I'm at my wit's end trying to figure our why it's not showing up in the render. If anyone needs more information, just ask and I'll get it to you. I've already checked the normals and they're not the cause.


My old passport is in my maiden name and has already expired. My B1/B2 visa to travel to United States is still valid but is stamped in my old passport with my maiden name.   My new passport has my new name (old name got changed after marriage) but has details (like old passport number, father and mother's name) related to my old passport.    Will I be allowed to travel to US as long as I carry the my old as well as new passport?  Or Do I need to again get the visa stamped on my new passport?

I have a valid B1/B2 US visa expiring about a year from now. The passport it's in expired a few years ago, and I recently got a new one.   The passport number does not match, but the national ID number, mentioned in both, does (it used to be the same as your national ID, but not anymore)  Can I travel to the US carrying both passports? Or is it asking for trouble? (I read a few years ago that it was possible, but that might have changed)  Should I just get a new visa to avoid potential complications?


This request was triggered by the very recent blog post , which announced that now, also retroactively, the askers are given as many reputation points (10) as the answerers for each upvote. This does reward the askers, but also takes away from the answerers by diminishing their relative standing. As an arguably extreme example, suppose that Alice has earned a reputation of 1000 points entirely by answering, and Bob has earned a reputation of 600 points entirely by asking; then now Alice will still have 1000 points, while Bob will move ahead of her, now with 1200 points.   Apparently for reasons like that, the mentioned blog post has generated some angry comments (as well as approving ones).   In a comment at , Frank Conijn suggested to      "split the reputation into one for questions and one for answers. Yes indeed, a two-figure reputation."    This seems to be quite a reasonable suggestion, with no apparent downsides. At least two upsides: it will     be more informative;  make the dispute between relative merits of asking and answering completely unnecessary.    A  was asked 10 years ago, which now seems to have acquired new relevance. Most of the objections there were about, again, relative merits of asking and answering, which do not seem relevant.   The only objection there of another kind was this:      "You can't really do it because you can earn a whole bunch of upvotes after you hit the daily rep cap. So any split like this could be really misleading."    I honestly do not understand at all what this problem with the cap is. Whatever it may be, can't it be solved by using caps separately for questions and answers rep points? Or by abolishing the cap altogether?     Added in response to comments and the answer by Glorfindel:  (i) About privileges, we can just use the total, as is done now.   (ii) I cannot imagine that having two numbers, instead of one, can be considered a "mental load". That would be more informative, though. The suggestion by Liam Morris - Reinstate Monica, to have the two numbers only in the profile information, also seems good.   (iii) Edits to questions, as well as to tag wikis/excerpts (which concern tagging questions), would add to the Q rep. Edits to answers would add to the A rep.   (iv) For bounty, it may be left to the users, where to take their points from.     Remark: My question is not a duplicate of , despite the title there. Indeed, that question is actually about a very different matter: namely, whether bugs, feature requests, and discussion eventually get reviewed by a moderator.

I'm creating this because the answer to   says that Jeff periodically reviews things with a "feature-request" tag.   comment from DVK suggests     ... separate Q from A rep ... allow people who do answer question to have a separate   grading curve—see my    ... as to WHY the curve needs to be different.   Yet, I can find no such "feature-request" tagged item.


I've watched "Once upon a time in Hollywood" and it seems to me that Cliff Booth here is one of two main characters. Why is Brad Pitt nominated as a supporting actor?

On what basis,  is considered as a Lead actor in the movie ?  In the movie, both characters have equal importance and both narrated the story in equal measure and occupied same amount of screen space, how come  is a supporting actor in the movie Rush?  I’m very intrigued to know on what basis Leading Actor and Supporting Actor is categorized in Hollywood.


I am using PgAdmin4 3.3, and I am trying to setup a server connection to a database through an SSH tunnel.  My database runs on port 30000 on the host. Setting it to 5432 is unfortunately not possible.  When I tunnel that port manually in the terminal it works perfectly: ssh -L 30000:127.0.0.1:30000 user@host  My server configuration is then to connect to localhost on port 30000.  If I now disconnect the ssh session and try to configure it directly in the pgAdmin UI, it wont work.    After I save the config and try to connect to the database it takes about a minute and then I get a connection lost message.  Thanks in advance!

I installed the latest pgAdmin 4 (v2.1) but I found out that (), for the moment, the only way to establish a connection through an SSH tunneling is using another outside process, an  says:  I setup a tunnel as follows: ssh -f dpage(at)hostname(dot)enterprisedb(dot)com -L 5999: hostname.enterprisedb.com:5432 -N  (...) I was running on Mac, but the same procedure should work on Linux. On Windows, there's a tunnelling app in Putty iirc, but I don't know how to use it offhand.  I have found a simple . The connection is established but it seems, when I try to connect through pgAdmin it fails or is refused (using 127.0.0.1:3306 or 127.0.0.1:5432 as the tunnel's destination). Why?


How can I delete the back of a face from an object in Blender 2.77? Because my object in XNAlara posing studio had backface culling and I want it to be fully shown, not partly hidden.  I want the object to look like this:    But it looks like this if back face culling is enabled:

How do you hide back faces so that you only see faces when its normal is facing the camera? When exporting it for use in a game, the face is rendered in only the direction of its normal, so this would be useful to have something similar.


If I do assign variable x = "189371971441827056" and then  I do,      parseInt(x)   189371971441827070   The value of parseInt(x) changes. I don't understand why?  Thanks in advance...!!

Is this defined by the language? Is there a defined maximum? Is it different in different browsers?


I wanted to ask for some recommendations for JavaScript tutorials on Stack Exchange, when I noticed, that this kind of question is against the rules. Then I found , and I thought that was sort of a place where my question might fit - recommendations are okay there - but then I noticed that such question would be against the rules there too: The  says:  While this includes software libraries for development use, note that recommendations of tutorials, data sources, media libraries (e.g. icon collections) etc. are off-topic  I'm an autodidact learner (as most of the people here, I've heard), and I got really pleased when I found this page. I'd be pretty disappointed if I had to realize that there are some topics I have to find getting answers somewhere else. :( (as you can see in the question I wanted to post, I have problems with googling also. Ohh, damned I be!) So is there a place for such questions? What's the best way to find out which site fits any tech related question I might want to ask? I seem to realize that I had misunderstood the aims of this website, but can you tell me why the rules are this strict? What should I do, when I don't even know the question?  Here's question I was about to ask:  I have some knowledge of ,  and . I've learned about  and I'd like to play around with it. My problem is that before I got into it, I should have some understanding of , I'm looking for a guide for this case. I'm new to web development and I'm not particularly interested in JavaScript. If I could google better, probably I would already have the answer, but all I found when I was looking around  was:  either JavaScript tutorials which takes too much time to explain basic programming ideas Too advanced tutorials which goes way deeper into the topic then I was intended to.  Do you have some good material for this?

Where should I post question like:     Where can I find books on [some programing subject]?   or      Online sources for learning  [some programing technique]?   ? ? Should it be community wiki? or is it a taboo in the ?


I want to speed up my work. How could I get ArcMap to stay at my current zoom level when panning to a new feature?  What I am currently doing is using Ctrl+Enter to move through my attribute table and Ctrl+= to zoom to my point. However, ArcMap will not maintain my current zoom level and no amount of messing around in scale settings has kept it where I need it to be. Even if I have only the scales I want in the drop down it will still put me at 1:7534 anytime I zoom to a new point.

I'm looking for ways to browse through a bunch of points that I have so that I can assign each of them a value. Ideally I would like to be able to use a button on the keyboard to step through each individual point (while keeping the same zoom level) so that I can keep my cursor over my attribute table in order to assign a value to the point. I have used Browse Features before and I know that is an obvious solution but I currently do not have the extension. Data driven pages does work, but it doesn't select the feature so it is easy to get lost where I am when I am in the table when I go to assign a point. I also have to move my cursor to click next page which is slow and clunky and I can't seem to assign a keyboard shortcut to it as well. It also doesn't seem to update the value in the drop down menu to what I have assigned to the name field so I can't keep track of where I am in the table with that either.   Does anyone have any ideas? Being able to stay zoomed in is also important since I need to be able to see the color of the pixel from my imagery that my point is sitting on top of.


In Adventurer's League Season 7, which creatures are PCs allowed to polymorph themselves or others into? Do they have access to the entire SRD, or only a limited set of creatures?

Can a lycanthrope or other shapeshifter be willingly affected by the spell True Polymorph? I know that it can be affected by regular Polymorph, but the text for the enhanced version seems to differ.


I am trying to write a dieresis with TexWorks (version 0.4.5 with Windows 8.1, if needed) with the code:  \"{a}   it should be correct, but this is what I get:

In tex file:     Toks\"{o}z   It produces


Consider an element $X\in\mathfrak g$ of some Lie algebra $\mathfrak g$. I understand that $\mathfrak g$ can be represented via its action on other elements of the same algebra, as $\operatorname{ad}(X)Y\equiv[X,Y]$, so that $\operatorname{ad}(X)\in\operatorname{GL}(\mathfrak g)$.  One often considers things such as the trace of these objects (e.g. when considering the Killing form), or more generally the "matrix elements" of operators such as $\operatorname{ad}(X)$.  However, I usually don't see any direct mention of the inner product with respect to which these things are defined. To properly define what something such as $\operatorname{ad}(X)_{ij}$ is, don't I need to be able to define uniquely the coefficient of the generator $X_i$ in the decomposition of $[X,X_j]$ (denoting with $\{X_i\}$ the elements of some basis for the algebra)?  Is there a canonical choice of such inner product? And on a similar note, do we just usually assume that the basis of the Lie algebra is orthonormal (or at least orthogonal) with respect to this inner product?

$\DeclareMathOperator{\tr}{trace}$ I am reading the  on the trace operator. The section titled Coordinate-Free Definition defines the trace as follows.  Let $V$ be a finite dimensional vector space over a field $F$ and define a bilinear map $f:V\times V^*\to F$ as $f(v, \omega)=\omega(v)$ for all $(v, \omega)\in V\times V^*$. This maps induces a unique linear map $\tr:V\otimes V^*\to F$. Since $\text{End}(V)$ has a canonical isomorphism with $V\otimes V^*$, we have now a notion of trace of a linear operator on $V$.  The Question: The second paragraph of the section in the article says that  This also clarifies why $\tr(AB)=\tr(BA)$.  I can't see how $\tr(AB)=\tr(BA)$ follows from this definition at all. Can somebody give me a hint?


What is the most efficient way to do this ?   I have a  ArrayList list called windowList.   GameWindow is bean having startTime and endTime.  For each object i recieve, I need to check the window of the object belongs to any of this windowList values. I need to do it for millions of values.  Please help me with most effeftive way to do this ....

I have an ArrayList of objects in Java.  The objects have four fields, two of which I'd use to consider the object equal to another.  I'm looking for the most efficient way, given those two fields, to see if the array contains that object.  The wrench is that these classes are generated based on XSD objects, so I can't modify the classes themselves to overwrite the .equals.    Is there any better way than just looping through and manually comparing the two fields for each object and then breaking when found?  That just seems so messy, looking for a better way.  Edit: the ArrayList comes from a SOAP response that is unmarshalled into objects.


I have setup one application 'phanthomjs' that is running of specific port 6423 I wish that it should be accessible to script that are run locally on the box 'localhost', not accessible from outside.  phantomjs--webdriver=6324  my current script make use of TCP and run on same box and we make use server name as localhost for making connection to the application.  Is there any way to in Redhat Linux box to block the access to this port from outside?

I have struggled throughout the years to get a solid understanding on iptables.  Any time I try and read through the man pages my eyes start to glaze over.  I have a service that I only want to allow the localhost to have access to.  What terms (or configuration, if someone is feeling generous) should I Google for to allow only localhost host to have access to a given port?


This has been something that I can't seem to wrap my head around. Just about every modern processor is able to execute more instructions per second than its frequency.  I can understand why lower class processors can execute fewer IPS than its frequency. For instance, the  executes about 16 MIPS at 16 MHZ (or at least that's what I've been told), and the  executes 0.5 MIPS at 4 MHz. But then the Pentium 4 Extreme can execute more than 9 GIPS at only 3.2 GHz. That is about three instructions per clock cycle!  How is this done, and why isn't this implemented in smaller processors, such as  microcontrollers?  I found all of my information, except for the ATmega328, from .

Why, for example, would a 2.66 GHz dual-core Core i5 be faster than a 2.66 GHz Core 2 Duo, which is also dual-core?  Is this because of newer instructions that can process information in fewer clock cycles? What other architectural changes are involved?     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this question. Feel free to edit the answers to add additional details.


I've installed Ubuntu on my laptop, but when I open Ubuntu, it says the following message (initramfs) Unable to find a medium containing a live file system  Can anyone help?

Error message:  (initramfs) unable to find a live medium containing a live file system   I got this error while trying to install Ubuntu 10.10 from a bootable USB stick on to Asus X64J series laptop. After getting this error the installation fails to start.  I have used the same USB stick on some other laptops and the installation started as usual. Any help will be appreciated.


What is the difference between IComparable and IComparer Interfaces? Is it necessary to use this interface always with Array.Sort() method

I'm trying to figure out which of these interfaces I need to implement. They both essentially do the same thing. When would I use one over the other?


How to keep all the features in this template but remove the Elsevier and date at the bottom of pages.  \documentclass[preprint,12pt]{elsarticle} \usepackage[english]{babel}  \usepackage{graphicx} \usepackage{amssymb} \usepackage{cite} \usepackage[superscript]{cite} \usepackage{lineno} \usepackage[colorlinks=true]{hyperref} \usepackage{natbib} \usepackage{footnotebackref}  \begin{document} \begin{frontmatter}  \title{\textbf{what and why}   \begin{abstract} this is abstract \end{abstract}  \begin{keyword} \hspace{-0.5cm} social epistemology, testimony, manipulation, truth, knowledge \end{keyword} \end{frontmatter} \end{document}

I would like to modify the footer used by Elsevier's  without editing the class file directly.  I would like to eliminate the footer on the first page that states "Preprint submitted to Elsevier" (or the journal you specify with the optional \journal{} command).  Obviously I can just delete it from the class file but this change won't carry over to others without me providing an explicit modification of the class file.  I tried adding the modified lines of the class file to my .tex before the documentclass declaration, but they are ignored:  \def\ps@pprintTitle{% \let\@oddhead\@empty \let\@evenhead\@empty \def\@oddfoot{\footnotesize\itshape % line below modified from elsarticle.cls  \ifx\@journal\@empty Elsevier \else\@journal\fi\hfill\today}% \let\@evenfoot\@oddfoot} \documentclass{elsarticle}   Is there any way to remove that footer without editing the .cls file?


Is it possible to use meta+arrowkey+arrowkey as a shortcut?

I want to change the key bindings on some of the keys on my keyboard.  I want some to run commands and others to activate different keys.  What applications can I use to do this?      Index:       (from within System Settings)             I'm still looking for answers using dconf and any other method.


PyCharm (4.0.6) complains when I do a comparison to an empty list using the == operator, but it doesn't when I use the is operator:    I guess this is something related to PEP 8, but the problem is that when I use the is operator, as PyCharm suggests, I have a false negative. Here is a simple example in iPython shell to show that in this case the == operator seems more appropriate, since the is operator returns a false negative:  In[2]: actions = [] In[3]: actions == [] Out[3]: True In[4]: actions is [] Out[4]: False   Could someone please explain why PyCharm complains about the == operator when comparing to an empty lists? Am I doing something wrong according to PEP 8?

For example, if passed the following:  a = []   How do I check to see if a is empty?


This is something I've done 100 times, but I can't spot why it's not binding. I'm creating a itemized list from a TAFFY database.  // get matching data from tfPLdata var ts=""; var match=0; tfPLdata({"vType":{likenocase:vType},"vSubType":{likenocase:vSubType}}).each(function (record,recordnumber) {        match++;     ts+="
";         ts+="
"+record["vTypeName"]+"
";         ts+="
"+record["vPrice"]+"
";     ts+="
"; });        the result looks like this

my corn seed 2

165.00

my corn seed 1

150.00

   then I'm trying to bind CLICK to the class .vWRAP  $(".vWRAP").click(function(){         console.log("test"); });    but it just doesn't fire.  Why?  ========================================  I added the code:  $(function() {       $(".vWRAP").each(function(){         console.log( $(this).attr("id") );         $(this).click(function(){             console.log("test");         });       }); });            and it correctly shows the ID for each .vWRAP. It still won't bind "click" however.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


What happens if a deleted question is nominated for reopening by 5 users?  Why can we vote for reopening if the question is deleted?        (I voted for reopening after the question was deleted. Just for testing.)  Let's test it together .

I've seen .  Voting to undelete will not work because it was deleted by a moderator, but I managed to vote for reopening for some reason.  I doubt this is intentional, perhaps not as important, but still.


I'm trying to add some images, but When i compile it, an error is shown, and in the PDF the images are not showed.  Code I have used:  \begin{figure}[!h] % h-here, t-top, b-bottom \begin{center} \includegraphics[width=0.9\textwidth]{figs/Captura1.jpg} \caption{Figure 1: Screen-shot of a Wireless Follow-me-MP3 Controller} \end{center} \end{figure}   The libraries:  \documentclass{llncs} \usepackage{llncsdoc}         % the original package lncs \usepackage[dvips]{graphicx}  % for images   And the error that returns:    Thanks for all

I'm trying to include graphics in my Latex-file, which I compiled with latex+dvipdf on OS X. Latex however returns this error: "Cannot determine size of graphic"  My graphic is exported from PowerPoint, so I have tried both .pdf and .png. I get the same errors for both.  Sample code that doesn't work:  \begin{figure}[htb] \begin{center} \leavevmode \includegraphics[width=0.8\textwidth]{graph.png} \end{center} \end{figure}   If I have to manually set some measurements of the image, please tell me how I can find out those measurements. I need the image to take up about 80% of text width and be centered. Thanks.


I have a list of market data tables in one of our environments and need to search every column in the list for a certain string. Can anyone point me in the right direction.   1> select @@version 2> go      Adaptive Server Enterprise/15.0.3/EBF 16558 ESD#1/P/Solaris AMD64/OS 5.10/   Thanks

I'm been taxed with the task of creating an application that pulls data from our Micros Point of Sales system. The POS is using a Sybase database running on one of our servers. The database schema is very convoluted. I've been able to figure out most of the schema to gain access to the data I need, however, there are a few things still left to find. I know what they are called in the actual POS, but I can't seem to find them anywhere in the database (although I haven't actually looked through all 200+ tables).  I'm wondering if there's any way to run a query to search for a specific string in all the columns in all the tables. BTW, I'm using the "Interactive SQL" application that comes with the Sybase Database Client software to connect to the database.


Today I tried installing Linux for the first time, and I can't get the Wi-Fi working. The Wi-Fi is built into the laptop, not a dongle.   Firstly, how do I know that Ubuntu is even seeing the card? ip link sho | grep w  gives me a result. Will the result be the Wi-Fi card and not something else like the USB Ethernet dongle?   Based on the output, the card is down. Nothing seems to enable it. e.g. sudo ifconfig <name> up makes no difference sudo rfkil shows this interface is unblocked, both soft and hard trying the command:wpa_passphrase MYSSID passphrase > /etc/wpa_supplicant.conf  results in permission denied, even if I try using sudo      Can someone please suggest what I should try next - or possibly try in the correct sequence.  Edited to add more information:  that I found yesterday before coming here for help:  Martin Thornton gave me the correct syntax to get the wpa_passphrase working. When I run iwlist scan, which is the next step in the walkthrough, it tells me the network is down.  The documentation linked below starts off with "Open the system menu" I don't think I have a menu?  Running lspci tells me the wireless card is an:  Intel Wireless 7260 (8086:08b1) rev 6b   sudo lshw -C network told me the wireless interface was disabled after running sudo ip link set wlp6s0 up, it seems the card is up. But iwlist scan still returns no scan results

I cannot get wpasupplicant, wireless-tools, and also lib, iwconfig (Iget ifconfig) to operate on my Server 18.04 install.  I have Windows 10 on laptop. External HD with 18.04 Desktop and 18.04 Server.  Wireless works fine on the other two OS, but not non-GUI Server CLI. I can’t install packages with no wireless.  I AM ABLE to go to  and get any package I want via search.  I AM ABLE to save these *.deb files on the /home drive of the server partition, reboot into Server, run some sudo dpkg and sudo apt-get install commands (all CLI). Some of it appears to install some but I get a lot of errors too. My guess is it’s trying to reach out over wireless for some of the packages parts but no wireless enabled? I’m not sure what a good order of package installs to enable wireless would be.  It seems that this issue would have a “recipe” for a good method and order of installation of certain packages to enable your intel 7265 network controller (wlo1), if not a basic recipe for installing packages for wireless without wireless or Ethernet access.  Remember, I can surf the net with Desktop and download packages to a server directory.  Right now every package seems to be looking for missing parts. I'm hunting with a blindfold. I'm using WPA encryption.  These are *.deb packages and *.iso files I have access to in server:    @chili555 I can't use iwconfig because I can't install wireless-tools without internet? I can't seem to install packages from my dual accessible drive shown in the picture above? I also get the following with sudo cat /etc/netplan/*.yaml:    Thank you for the welcome.  ipaddr show gives me this:  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: wlo1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000     link/ether e4:42:a6:a0:42:95 brd ff:ff:ff:ff:ff:ff


We know to take a noiseless night landscape/cityscape, we need use a tripod and set a low ISO. For example in a scene I use ISO 100, aperture f/8.0 and exposure time 30 seconds, I get a night cityscape bright enough and very clean.  My question is, in the same scene described above, if I want to take a portrait and have the same image quality for the background cityscape, how to achieve this ? I can use flash, tripod. Don't forget when focus on the person's face and want have a background in focus, I need use aperture f/8.0 or smaller.  I know slow sync flash, but it will set something like shutter 5 seconds and ISO 800, so the background is not as good as the photo taken with ISO100 and the people maybe blurred a little.  Or some ways in post processing ?

How can I take a photo which shows the skyline and the person who is standing around six feet away from the camera with proper lighting at night?   For taking just the skyline I've used long shutter speed and it turned out great, but when including a person on it, the person becomes  blurry because it's impossible for a person to remain static for that long.   Ps.  I do have two flashes, 35mm prime lens as well as 18-300mm zoom lenses as well. The camera I use is Nikon D7200.