What is the correct phrase to be used among these two:   Too short a time Or Too short of a time   Which one is correct for daily English usage?

Recently, when writing an email, I used the following phrase:  'I hope this does not cause too big of an issue'  However, in their response, the recipient (an English teacher) said that he was 'not too sure about the grammar of "too big of an issue"' (with no further comment). However,  seems to suggest otherwise. What could he have possibly picked out as incorrect in my usage of the phrase, and is it really significant enough of an issue to remark on in a response?  This question is not a duplicate because I'm asking about whether the phrase itself is correct, not the etymology of it. Further, it's considering the whole phrase (e.g can an issue be 'big', or should it be 'significant'?), and not just that one part.


There are many things with different textures that appear white – salt, beer foam, paper, shaving cream, snow, talcum powder, white paint, etc. The most common answer is all of the frequencies must be reflected in order for us to perceive white, which I already know. There must be more underlining details why such a huge variety of things are white. Furthermore, if you wet paper, snow or talcum powder, they appear off-white or gray. Why is this?

When something gets wet, it usually appears darker. This can be observed with soil, sand, cloth, paper, concrete, bricks...  What is the reason for this? How does water soaking into the material change its optical properties?


Is it the following correct to say?      May I kindly request ..."    As when calling a celebrity onstage during an event Would it not be better to say,     May I request so and so to kindly come ...

I just want to know I would like to kindly ask you could you check......? could be a right structure for asking question?  regards


Class jquery hover function are  working after scroll.   $(document).ready(function() {     $('img').hover(function(){         alert('hello');     },function(){         alert('hello not');     }); });   on hovering images loaded on first site are showing alert hello but after scroll images load(lazzy loading). On hovering those images alert is not showing.

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.


$$ \lim\limits_{(x,y) \to (0,0)} \frac{2x^2y^3}{x^4+y^6} $$ My reasoning after reading the textbook: Direct substitution wouldn't work since it would lead to the indeterminate form $0/0$. We can examine the values of $f$ along parabolic curves that end at $(0,0)$. Along $y=kx^2, x\neq0$, the function has the value $$ \frac{2k^3x^4}{1+k^6x^8}. $$ So, if $(x,y)$ approaches $(0,0)$ along $y=x^2$, then $k = 1$, and the limit is $\frac{2x^4}{1+x^8}$. If $(x,y)$ approaches $(0,0)$ along the $x$-axis, then $k=0$, and the limit is $0$.Is this correct and/or is there another way to go about this? Thanks.

I want to determine $$\lim\limits_{(x,y) \to (0,0)} \frac{x^2·y^3}{x^4+y^6}$$  I'm sure the limit exists, it's zero because I tried to find other different limits in line and parabola points ($(x,mx)$ and $(x,mx^2)$) but every time I got zero. So, I have to use the definition or sequences to confirm.


I've been trying to write a formal proof of the following, but it's been rather annoying. any help is appreciated Prove that for every 3 consecutive numbers n,n+1,n+2. there exists a x = {n,n+1,n+2} number, such that |sin(x)| >= 1/2

How to prove that at least one of the absolute values of sin(n) ,  sin(n+1),sin(n+2) is greater than 0.5. I tried to split it to cases but i cant handle sin(1),...sin(29) maybe i should work with radians. In the first section I proved that the series sin(n)/sqrt(n) converges in condition. Can anyone help how to prove it? Thank you in advance.


I faced strange issue, as usual after wake up (during work), every popup window  (menu, list and etc) appeared with with a border like on the picture. Ubuntu 16.04. Only relogin or restarting helps. It never happened before this week.

NB: Nvidia has released an official fix; please see ,  and/or .  Upon waking up Ubuntu 16.04 from Suspend, the following graphical glitches appear around all windows, context menus, and similar:      This is currently known to affect the following NVIDIA cards running the proprietary drivers:  NVIDIA GeForce 610M, driver version 375.39, 340.102 NVIDIA GT 630M, driver version 375.39 NVIDIA GTX 650, driver version 375.39 NVIDIA GT 740M, driver version 378.13 NVIDIA GTX 745, unknown driver version NVIDIA GTX 850M, driver version 375.39, 378.13 NVIDIA GT 940M, driver version 375.39 NVIDIA GTX 950M, unknown driver version NVIDIA GTX 960M, driver version 378.13 NVIDIA GTX 970, driver version 375.39 NVIDIA GTX 970M, driver version 375.39 NVIDIA GTX 980 TI, unknown driver version NVIDIA GTX 1060, driver version 375.26, 375.39, 378.09 NVIDIA GTX 1070, driver version 378.09  The above above list has been sourced from reports from other users here on AU,  thread, and  thread. NB: This is be no means an exclusive list. It probably effects nearly all Nvidia cards.  Furthermore, this issue has been replicated on a clean install where the only change was a software update and the installation of the latest NVIDIA drivers.  What is going on, and how can it be resolved?


My side project got accepted to a conference and my advisor is not involved in the project. How can I find travel funding?  My advisor has kind of discouraged me from having side projects (but doesn't forbid me), and doesn't have a lot of money in general, so I would be afraid to ask him.  The main person I am working with on the side project is no longer at the university (he is now at a different university).

I am an undergraduate student doing independent research. My research work is selected for presentation at a very reputed conference in the US. I am from India. I cannot afford to attend the conference at all. How should I fund my trip? The travel grant for students available from the conference is very low. It can hardly buy me a one way ticket. What are my options?


How does Community have a hat on? On site to site, it changes, but how?

On English Language & Usage, I noticed that even the  user has hats.    In its case, how is the hat it is wearing selected?


Using residue theorem, find the value of $$~\int_0^{2\pi}\dfrac{d\theta}{1-2a\cos\theta + a^2}$$ for $~|a|<1~.$  I know that the value of the integral is $~\frac{2\pi}{1-a^2}~$(I found it by using the rule of normal definite integral), but don't know how to find the same by using residue theorem. Any one please provide me a complete solution by using residue theorem.

So I have some troubles for the following question: Using the residue theorem, calculate :  $\int_{0}^{2\pi}\frac{1}{1-2a\cos{\theta}+a^2}d\theta$ with  i. $|a|$ < 1 , ii. |a| > 1  I guess that i. and ii. would give us different residues to calculate given that the surface isn't the same.  First I solved for a in the denominator. I get a= $\cos{\theta}\pm\sin{\theta}$. Now I could use the fact that $\cos{\theta}=\frac{e^{i\theta}+e^{-i\theta}}{2}$ but I don't really see what to do next. I have seen other questions like  but the conditions and the function aren't exactly the same and I'm still stuck.  Thanks for your help !


I'm stumped on a line of code in Python that I'm supposed to translate. Most websites don't have a clearer example of my situation now.          output_qr_dim, and i are just integers      output_r[output_qr_dim * i:output_qr_dim * i + output_qr_dim, output_qr_dim * j:output_qr_dim * j + output_qr_dim] = ra   At first I thought it means you just complete the operations on either sides of the :, then only perform the slicing. But according to this website, , the slicing takes precedence over the other operations, so I'm rather confused at the moment.  Any help would be appreciated

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


I'm trying to grab a text enclosed between two words, but the problem is that I can make the regex grab all the text including especial character. Here is an example of what i'm trying to grab:  Example:     Part. 23.00.  Random.  In this chapter:      (1)Hello 1.      (2)"Hello"2.      Action 10 5th.      I don't want to grab this      Part.12 Hello      Action 12.   I need to grab everything from Part.23 to Part.12 except the "I don't want to grab this" text.  Thank's in advance for the help.  This is my regex:   (Sec\.\s*\S+.*\n.*\D.*\D.*|Acts*\D\s.*)

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


Let $f:D(0,1)\longrightarrow \mathbb{C}$ be a holomorphic function  such that $f(z)\in\mathbb{R} \Longleftrightarrow z\in \mathbb{R}$. How to prove that $f$ has at most one zero on the disk.    By hypothesis the zeros of $f(z)$ are real and $\displaystyle f(z)=\sum_{n=0}^\infty a_nz^n$ , $a_n\in\mathbb{R}$ since $f(z)=\overline{f(\overline{z})}$.  Any help would be appreciated.

Could someone advise me on how to approach this problem:  without  the use of argument principle ?    Here is my attempt: Suppose $f(z)$ has two zeroes at $z=a.$ Let $f(z) = \sum^{\infty}_{n=0}a_n(z-a)^n, \forall z. \ $   Then $f(z)=(z-a)^2 \left(\dfrac{a_{0}}{(z-a)^2} +\dfrac{a_1}{z-a}+a_2+a_3(z-a)+...\right)$   $\implies a_0=a_1=0.$  $\implies f(z)= (z-a)^2\left(a_2+a_3(z-a)+a_4(z-a)^2+...\right)$  $\implies .... ?$  Thank you.


I have just noticed that we have had 25 reopen votes in the review queue all of a sudden. I was doing reviews, it was zero when it got bumped all. I am wondering why this may have happened. See the screenshot below.  This is similar to my  an the one referred inside that, where the root causes ware a bug that had been fixed and a workflow. I am wondering if that bug is recurring or it is due to something else?  Thank you in advance.

I have just noticed that we have had 63 reopen votes in the review queue all of a sudden. I was doing reviews, it was zero when it got bumped all. I am wondering why this may have happened. See the screenshot below.    I have  thread where the root cause was a change in the workflow, so I wonder if there is similar here again, or it is because of something else?  Thank you in advance.


If we launch an object on one side of the moon (the velocity being tangent to the surface of the moon), how big must the velocity be to let the object arrive at a position on the moon diametrically opposite to the launching site (in some device to catch the mass)? The mass is very, very small compared to the moon's mass.  The acceleration due to the moon's gravitation is, of course, dependent on the distance to the moon (inverse square law).  Because of this dependence on the distance of the acceleration, it's more difficult to compute a trajectory, especially this particular one that also involves the curvature of the moon. I guess integration is involved, but I don't see how. For sure the velocity has to be higher than the velocity (which is easy to calculate) to let the mass make a circle around the moon. If we didn't catch the mass on the other side, the trajectory would resemble something that looks like an ellipse. This trajectory doesn't consist of two (opposite) parabola's because the trajectory in the question isn't a parabola, again because the acceleration depends on the distance of the mass to the moon.  Is there someone who knows how to do the calculation?

We know the optimum angle for greatest horizontal displacement when launching an object with projectile motion is 45 degrees.  How to solve the angle when it is real long distance around the earth where we cannot assume that gravity is constant but is given by $F=\frac {-GMm}{r^2}$. I use differetial equation to solve it and obtain 45 degrees.   First, for the vertical distance $y$, change $v=u-gt$ to $y'=u-y''t$. Then solve it to obtain a function $y(t)$. When $y'(t)=0$ we have the time for maximum vertical distance. Then insert the value to horizontal equation.   Can anyone guide me through this problem because I am not confident with my working


(inspired by )  In the movies the pilots of TIE Fighters are shown wearing the same (or at least similar) masks like the Stormtroopers.   Are they clones too? The Stormtrooper clones are "programmed" for grunts but programming a clone for a pilot would be much more difficult.

Reading this article about , my nerd-rage started flaring as they claimed that Stormtroopers were still Fett-Clones 20 years after the rise of the Empire.  As I started thinking about it, I realized that everything I had read saying that Modern-Day Stormtroopers not being clones was from the EU - C Level books or games.   One of the quotes often cited for backing the idea that the Stormtroopers are clones comes from Princess Leia:     Aren't you a little short for a Stormtrooper?   But through the movie, paying close attention, Stormtroopers are often shown to be slightly different heights. One even hits his head in the doorway while others walk through uninjured.                                  Is there any G Canon fully canon (non-Legends/Infinities) evidence to support the idea that Stormtroopers are, or are not still clones at the time of Episode IV?


In the opening scene of Star Wars:  Episode IV:  A New Hope, as 3P0 and R2D2 are scuttling about the ship, 3P0 says:     "There'll be no escape for the Princess this time".     Obviously, he knows who Leia is.  But later, when Luke removes R2's restraining bolt, inadvertently causing him to play back part of Leia's secret message, Luke asks who the woman in the hologram is, and 3P0 says:     "I'm afraid I'm not quite sure, sir... I think she was a passenger on our last voyage. A person of some importance, sir -- I believe."   Now, R2 doesn't trust Luke yet, and deliberately avoids playing the full message for him.  But 3P0 trusts Luke immediately, and actually chides R2 for his insolence, reminding him that Luke is now their master, and therefore deserves their obedience and respect.  So why does 3P0 hide the princess' identity from Luke?  Even more important, why does he actively lie to Luke?      Note:  I know that some people will claim that 3P0 knew that Leia was important, and that there was a princess onboard the Tantive IV, but he didn't necessarily know that Leia was the princess.  This is extremely unlikely.  Wookieepedia says that the Tantive IV held about 85 passengers and crew, a relatively small number, which makes it very likely that 3P0 would have known who the princess was.  It also seems unlikely that 3P0 would show such concern about someone he has never met.  If he doesn't know the princess, why single her out as a special cause for concern, as opposed to all the people he does know?  He apparently belongs to Captain Antilles - if he didn't know the princess, wouldn't he say "There'll be no escape for Captain Antilles this time"?

At the start of A New Hope, when the corvette is being attacked, C3PO says something to the effect of:     There'll be no escape for the princess this time.   But when Luke stumbles onto Leia's message in R2D2, C3PO seems to not know who the figure in the message is:     I'm afraid I'm not quite sure, sir. I think she was a passenger on our last voyage. A person of some importance, sir - I believe.   Is C3PO feigning ignorance to protect her, or does he really not recognize her?


I am trying to attach a custom js library to the contact module. Here is the content of my js/custom.js file: function myFunc(){    console.log('hello toto'); }  document.addEventListener('click', myFunc, false);  Here is the content of contact.info.yml: name: Contact type: module description: 'Provides site-wide contact forms and forms to contact individual users.' package: Core # version: VERSION core: 8.x configure: entity.contact_form.collection  # Information added by Drupal.org packaging script on 2020-10-07 version: '8.9.7' project: 'drupal' datestamp: 1602100551 libraries:   - contact/custom  and contact.libraries.yml: custom:   version: 1.x   js:     js/custom.js: {}  However, the custom.js library is not listed in js files when I open the contact page... Can someone please help?

I created a custom module in drupal 8. And I am trying to add js and css file in  my_module.libraries.yml file using this   lrv_key:   version: 1.x   js:     js/lrv.js: {}        dependencies:       - core/jquery       - core/drupalSettings   css:     theme:       css/lrv.css: {}   But it doesnt work.


Is it possible to change the toolbar icons in gVim (without patching the exe)?  It seems like you can change everything else, and they are so ugly...

I'd like to remove some of the default icons and maybe add one or two icons of my own. For example, it would be nice if there were icons for the NerdTree and the Taglist.


The purpose of this exercise is to prove that $\lim \frac{n}{(n!)^{1/n}}=e$ when $n$ goes to infinity.   In order to find the limit, the following inequality is used when $n$ goes to infinity with ${a_n}$ a sequence of positive terms:   $$ \liminf \frac{a_{n+1}}{a_n} \le \liminf (a_n)^ {1/n}\le\limsup (a_n)^ {1/n}\le \limsup \frac{a_{n+1}}{a_n}$$  What is the proof of this inequality?

This may have been asked before, however I was unable to find any duplicate. This comes from  of "Mathematical Analysis: An Introduction" by Browder. Problem 14:     If $(a_n)$ is a sequence in $\mathbb R$ and $a_n > 0$ for every $n$. Then show:   $$ \liminf(a_{n+1}/a_n) \le \liminf((a_n)^{(1/n)}) \le \limsup((a_n)^{(1/n)}) \le \limsup(a_{n+1}/a_n)$$   The middle inequality is clear. However I am having a hard time showing the ones on the left and right. (It seems like the approach should be similar for each). This is homework, so it'd be great if someone could give me a hint to get started on at least one of the inequalities.  Thanks.


I have friend that is working with a travel agency in Russia to visit me here in the US. She informed me that the travel agent told her she will have to prove solvency of 4500$ to get the visa or she would be denied. She has gotten her passport and the visa office in Russia has called and spoke with me and had me answer some basic questions. I very weary at this point cause she says she doesn't have the 4500$ and that she about 1900$ short of the 4500$. I would like to know if the solvency check is an actual thing?

On Travel.SE we often see questions about a person (usually a love interest) asking for money to pay for airfare, visas, permits and other expenses. For example        What general advice can be given in such situations to the person asking the question? Is it all a scam or can there be legitimate situations in which an online friend could be asking for money?


$$ \sum_{i=0}^n {2n \choose 2i} = 2^{2n-1} $$  I know what this sum is supposed to equal.  I also have a hint that I am supposed to use ${n \choose r} = {n-1 \choose r-1} + {n-1 \choose r}$    I was just wondering if someone could help me with where to start.   Do you start with:   $$ {2n-1 \choose 2i-1} + {2n-1 \choose 2i}$$ $$={(2n-1)! \over (2i-1)!(2n-1-(2i-1)!}+{(2n-1)! \over 2i!(2n-1-2i)!}$$

I'm repeating material for test and I came across the example that I can not do. How to calculate this sum: $\displaystyle\sum_{k=0}^{n}{2n\choose 2k}$?


How do you rename all files/subdirs in the current folder?  Lets say, I have many files and subdirs that are with spaces and I want to replace all the spaces with an underscore.  File 1 File 2 File 3 Dir 1 Dir 3   should be renamed to  File_1 File_2 File_3 Dir_1 Dir_3


I wanted to move some space from sda2 to sda5, but when I reduced space in sda2 there appeared an unallocated space which I couldn't use when I tried to resize sda5 (sda5 was unmounted) in gparted. What am I missing?

How can I expand/resize my extended partition (sda3) with unallocated free space to the left of it? I want this to be able to expand my / partition (sda5).


In my app I am running a method that takes few seconds to run and I need to fire that multiple times with different parameters to achieve what I want. Later on I started having performance problems and decided to fire those actions in multiple threads to reduce the time spent for running it. I implemented everything as expected, but when it comes for firing that thread it just freezes. It says threads are running, but never finishes. I thought maybe my methods that I am calling in threads are locking the same object and that is causing the threads to freeze, but it seems that is not the issue.   Here is a sample code:    public abstract class ModelBase {     public static void RunInMultiThread(List<Action> actions)     {          Action testAction = new Action(() =>         {             Console.WriteLine("Other test");         });         List<Thread> threads = new List<Thread>();         foreach (Action action in actions)         {             ThreadStart dlg = () => { action(); };             Thread thread = new Thread(dlg);             thread.Start();             threads.Add(thread);         }          bool anyAlive = true;         while (anyAlive)         {             anyAlive = threads.Any(t => t.IsAlive);         }     } }  /// <summary> /// This class is autogenerated /// </summary> public class Model : ModelBase {     public void FireActions()     {         List<Action> actions = new List<Action>();         for (int i = 1; i <= 100; i++)         {             Action action = new Action(() => { DoSomething(i); });             actions.Add(action);         }          RunInMultiThread(actions);     }      public void DoSomething(int a)     {         Console.WriteLine("Test " + a);     } }   I am creating the new instance of the Model class and calling the FireActions method. I can see the list of threads in the RunInMultiThread() method and it says all the tasks are running. I don't see anything in the output.  To make it simpler, I passed the testAction action to the ThreadStart and that worked. I am very surprised why it doesn't work if I pass the actions that came in the list?  NOTE: The Model class is actually autogenerated and located on another library and it's .NET version is 4.0. That library is built using the System.CodeDom.Compiler. ModelBase class is on another project and it's .NET version is 4.7.1.   Any ideas why it won't run my actions that is passed though the list??

I've been learning C#, and I'm trying to understand lambdas.  In this sample below, it prints out 10 ten times.  class Program {     delegate void Action();     static void Main(string[] args)     {         List<Action> actions = new List<Action>();          for (int i = 0; i < 10; ++i )             actions.Add(()=>Console.WriteLine(i));          foreach (Action a in actions)             a();     } }   Obviously, the generated class behind the lambda is storing a reference or pointer to the int i variable, and is assigning a new value to the same reference every time the loop iterates.  Is there a way to force the lamda to grab a copy instead, like the C++0x syntax  [&](){ ... } // Capture by reference   vs.  [=](){ ... } // Capture copies


Considering that all frames are equivalent, isn't it up to the observer to say "The earth turns around the sun" or "The sun turns around the earth"? Isn't this more or less like arguing about which meridian should be considered the null-meridian, or whether time should be counted according to years before/after Jesus Christ or the conquest of Mecca?

In history we are taught that the Catholic Church was wrong, because the Sun does not move around the Earth, instead the Earth moves around the Sun.  But then in physics we learn that movement is relative, and it depends on the reference point that we choose.  Wouldn't the Sun (and the whole universe) move around the Earth if I place my reference point on Earth?  Was movement considered absolute in physics back then?


I've seen many different ways to represent an object on a page as being draggable, but I was the most effective way in your experience of doing so?

My web application contains a list of elements, which can be sorted by drag'n'drop. How should this feature be visually represented to users?


My poster has a black background with text and images (font in colour white) on the top. When i save the poster only the images appear and the background has turned white, subsequently the font which was white over the top disappears. How do i save the illustrator poster with a black background? Thank you

I changed the background colour of my pdf through:  Document Setup -> changing color under "transparency" (grid color) -> checking "Simulate Colored Paper"  This changes the background in Illustrator as it should. The problem is: if I save the file as a pdf, the background if my pdf is white again :-(  Any idea how to solve this problem? Many thanks in advance!


This happened to two programs of mine now and makes absolutely no sense. It usually comes about when I'm adding a resource file (in this case, a menu). In the package explorer: -the project name has a small red x, indicating that there is an error in one of its files -none of the sub-folders or files have an x or show any red highlights  None of my code has errors! Ocasionally, I see this:  [2010-09-02 16:09:20 - FallDown] 'default' is not a best match for any device/locale combination. [2010-09-02 16:09:20 - FallDown] Displaying it with 'Normal, Not Long, Landscape, Medium Density, Finger, Soft, Qwerty, Trackball, 480x320'   What is going on?

I'm using Eclipse for Java development. All my sources compile fine and the resulting application compiles fine. However, I keep getting an "red-x" error notification in the Package Explorer.  All my sources in this source directory (too long for the snapshot) compile fine, none of the show the "red-x" error icon.  Any suggestions on how to fix the problem would be highly appreciated.


I'm a Kenyan citizen. I have lost my stepfather, who is a British citizen. Is it possible for me to get an emergency visa to come and attend his funeral? Thank you.

I'm a British national. My grandmother just passed. My wife is Chinese. In general it's a major pain to get my wife a visa to visit the UK, we have never been before.  Is there any way to get an emergency visa to attend the funeral?  What sort of documents would we need?


Current in a series circuit are the same everywhere, but when there is a bulb creating a potential difference, wouldn't the rate of the same number of electrons flowing, coming out from the bulb change as electrons lose energy or voltage to the bulb as voltage is what makes current flow at some rate? Could you explain this without using the analogies?

I have read in the internet that the charges do not have any other path to go and they must go through the same in a series circuit,hence the current is same.  It was quite convincing but what confused me was: "A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Resistors act to reduce current flow..."(according to the Wikipedia). This means that the resistors slow down the rate of flow of charges. By definition, electric current is the rate of flow of charges. Then must not the current be reduced in a resistor even when the amount of charge is same?


Modern CPUs employ a hierarchy of memory technologies. Registers, built into the chip have the lowest access times, but are expensive and volatile. Cache is a middle-man between RAM and registers to store data structures to reduce latency between RAM and registers. RAM holds, for the scope of this query, active program code and their data structures. Non-volatile storage is used by programs to save their data and hold the OS and its programs.   The latency of accessing data in memory has been a major bottleneck to creating faster CPUs that do not sit idle, awaiting further instruction. As such, various methods have been designed to parallelize workloads, CPUs to predict branching to hide memory access overhead, and more. However, the complexity of this has seemingly ignored another possibility: a whole-memory register file.  Such a CPU is built with 4, 8, 16, 32 GB or more, made of registers. No cache. No RAM. Just the CPU, the registers on the chip, and external non-volatile storage (SSD/Flash, HDD, etc.).  I understand that the demand for such a chip is unlikely to be sufficient to justify the cost, but I remain surprised that no one seems to have designed a simple device, such as a high-performance MCU or SoC with a small amount of register-only memory. Are there other (perhaps, engineering) challenges to the design and construction of such a chip?  EDIT to Clarify. I am not referring to a CPU in which all memory (DRAM technology) is integrated onto the CPU die, nor am I referring to a cache that is expanded to multiple Gigabytes. I am asking about a design in which the registers remain their existing technology... just expanded by a few orders of magnitude to be able to hold multiple gigabytes of data.

Modern CPUs are very fast compared to all things external, including memory (RAM).   It is understandable, since CPU clock frequency has reached a point where it takes several clock ticks for an electric signal simply to run from from the CPU through the bus to RAM chips and back.   It also complicates life on many levels: multi-level cache hierarchies are built to deliver data closer to the CPU, which in turn require complex synchronization logic in the chip. Programs must be written in a cache-friendly way to avoid wait cycles while data is fetched.   Many of these problems could be avoided if a significant amount of RAM was located directly on the CPU chip. It doesn't have to an exclusive arrangement: maybe put 1-4 GB on the chip, depending on its class and allow additional memory installed separately.   I'm sure there are good reasons Intel, AMD and the like are not doing this. What are these reasons? Is it that there's no room to spare on the chip?


Case I followed this  to create an effect that I want (being able to see a completely different world through an object (a shield in this case). I got this to work in blender 2.8+. The problem is that I have to render in cycles due to some nodes being used and these are only available in cycles. At the moment blender renders all 3 layers and smacks them together to generate the desired result which takes 3x as long. so my question is:  How can I preview this effect without having to render it? How can I tell blender to only render 1 layer to preview other effects?  Here are some screenshot of my project, hope it helps.  Shiled being used as mask  other dimension I want to capture by watching through the shield

Perhaps a reference video would be needed to show this, but to clarify, merely the portal and its animations appear nearly impossible to create, the frame itself is simple diffusion and optional reflection. Mind this is using cycles.   I though the best way to attain this would be to have the position of the camera changing cause a movement of the portal textures however it has proven futile.  And so I ask, is this possible in Cycles?  EDIT:  My original plan was to use the UV Warp modifier to create the movement effect, with several planes underneath each other to create the depth. However, the way it appears to be a void, another area is the piece I lack.   The frame of the portal, again, is not a problem.  In reference to a comment that referenced a similar concept using a Nether portal that showed the Nether upon the other side, is similar, however there is no need to create another world on the other side, as I want to stay true to the visual mechanics of Minecraft.  Here is an example of the in-game version of what the goal is.


I have a matrix of 32-by-32 LEDs that I need to control using a driver. The largest driver that I found was a 16-by-16 driver by Linear Technology, and there is no driver that goes higher than 16-by-16.  Here are the requirements:   monochrome LEDs (color not needed) LEDs just need to go on or off, no greyscale required pixels cannot be addressed individually, need to use column/row method   Is it possible to use two or more drivers together for this purpose? How? If not, what could be the alternative?

I would like to be able to control around 100 independent LEDs using an Arduino.  The problem is that the Arduino does not have nearly enough pins that can be configured for this.  What would be a way to solve this problem?  Is there a chip that can demux a more complex signal from the Arduino that could then control the LEDs?  Or is there another solution?


hello my var directory is full and i want to add space to directory but i can't. I have a lot of space in the /home and root directory and I want to give it to /var I used GParted as a live CD but it did not allow me to increase or decrease and I do not know what to do and i'm not professional please help me

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


If we use the MLE methhod to find the estimator of the variance we get:  $\hat\sigma ^2 = \frac{\sum(x_i - \mu)^2}{n}$  Where we can plug the MLE estimator for $\mu$ and get:   $\hat\sigma ^2 = \frac{\sum(x_i - \bar x)^2}{n}$  But we know that this estimator is biased, and in order to correct for the bias, we need to use $n-1$ instead of $n$:  $S ^2 = \frac{\sum(x_i - \bar x)^2}{n - 1}$  My question is why do we care more for bias than for the likelyhood? Subquestion - how much is the unbiased estimator less likely to appear given an (arbitrary) sample ?  Update:  I don't see how this is a duplicate. I understand that this estimator is biased. I completely agree with the answer given in the linked "duplicate". I'm asking something completely different. I'm asking why do we care more about correcting the bias, than we care about maximizing the likelihood.   In the normal example, the MLE estimators are what maximizes the likelihood function of our sample. So say we got $(\hat\mu, \hat\sigma^2) = (100, 25) $ for n of 100. Then correcting the bias will give us $(100, 25*\frac{100}{99} = 25.25)$ which will not maximize the likelihood. i.e. it is not the maximum anymore.   So why do we care about fixing the bias more than maximizing the likelihood? I guess the answer is that the likelihood is less important than the bias, though I wonder - why?

While reading , I ran into the following explanation for why there is an error in estimating the variance of Gaussian distribution using Maximum Likelihood. On ,      Illustration of how bias arises in using maximum likelihood to   determine the variance of a Gaussian. The green curve shows the true   Gaussian distribution from which data is generated, and the three red   curves show the Gaussian distributions obtained by fitting to three   data sets, each consisting of two data points shown in blue, using the   maximum likelihood results (1.55) and (1.56). Averaged across the   three data sets, the mean is correct, but the variance is   systematically under-estimated because it is measured relative to the   sample mean and not relative to the true mean.   I'm pasting figure 1.15 and the required equations (1.55, 1.56) here for convenience.  $\mu_{ML} = \frac{1}{N}\sum_{n=1}^{N}x_n$   $\sigma_{ML}^2 = \frac{1}{N}\sum_{n=1}^{N}(x_n - \mu_{ML})^2$    I can imagine how maximum likelihood estimation would look pictorially. However, I'm not able to understand the figure or the explanation. I would appreciate if someone could label the figure or explain what points are considered in each part of the figure and why the curve could look like that in each case.  I looked up , and I'm able to understand why there is a factor of $\frac{N-1}{N}$ between the true $\sigma^2$ and $\sigma_{MLE}^2$.  ${\rm I\!E}[\sigma_{MLE}^2]= (\frac{N-1}{N})\sigma^2 $


A lot of functions don't have elementary antiderivatives. Quite often I observed new special functions were defined that many of them are written in form of these special functions. Example: the dilogarithm, the airy functions, etc... When I looked up the some information I found that there special functions are defined by these integrals themselves. What is the use of such functions? How do they help us in developing "mathematics"? I am not asking for applications in other fields of science.

If you read enough mathematics, you eventually come across several so-called "special functions". I'm always left wondering what on Earth these things are actually for.  We have the Euler Gamma function, the Beta function, the infamous Riemann zeta function, the Airy functions, the Möbius function, the Bessel functions, the Jacobi theta functions, the digamma and polygamma functions, the polylog, the Chebyshev polynomials, Weierstrass's elliptic functions, the Dedekind eta function, the hypergeometric functions, etc etc etc.  If you try looking any of these functions up, you generally get a huge page of dense, complex-looking formulas recounting the sixteen different ways to define the function, the myriad of properties and identities it has, and so on and so forth. But nowhere does it mention why this is useful.  I have just about figured out that the Euler Gamma function extends the factorial to non-integer values. I still don't know how that's "useful" in some way. Bessel J somehow appears at random in a few unrelated contexts, as do the Chebyshev polynomials. And that's about as far as I've got.  Obviously, I'm not expecting anyone to give an exhaustive explanation of what every single special function ever invented actually does. I suppose that if you don't know what a function does, that means you probably don't need it yet. But I would like to have some basic intuition as to why all these millions of functions have been defined, and what people use them for.


In Linux Mint pressing the Alt+LMB moves windows. How would I select an edge loop in this situation?

I am trying to use the Alt+Right Click to select edge loops in Linux Mint but this shortcut doesn't work it is already used for Linux to reduce a window. I have checked the keyboard shortcut but it doesn't appear.


Existence of inertial frames is an empirical fact.    What observations conclude that the existence of inertial frames is an empirical fact?

Newton's first law states that in an inertial frame, a body at rest continues to be at rest, and a body in constant rectilinear motion continues its motion, unless an external force is applied upon the bodies. My question is how far have these assertions been tested experimentally? More precisely, is there any need to test this statement, or is it taken as a "definition" of sorts?  I assume the body at rest is a trivial case. On the other hand the case of the body in constant motion would be considerably harder to test, since no external force on a body is an idealization. But I am still curious whether there have been any attempts to test the case of the moving body.


I prepared the chicken marinade and forgot to keep it in refrigerator and it's been quite a couple hours that I realised and kept in fridge but I don't know if it's still good or gone bad. Please help. Also I can see something watery thing that's released. if it has pls help and tell me how can I correct it.

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


Let $f: X \rightarrow Y$ and $g: Y \rightarrow X$  If $f \circ g$ is injective and $g$ is surjective - is $f$ injective?  I am trying to learn the way of prooving things. So I'll give it a try and please correct at every wrong step.   I assume that the given statement ist true.   So first I give the condition that $g$ is surjective:  $\forall y \in Y : \exists x \in X:g(y)=x$  So two different $y$-values can point to the same $x$-value:  Let $y_1, y_2 \in Y, y_1 \neq y_2 : \exists x \in X : g (y_1)=x $ and $g (y_2)=x$  Next I want to connect the fact that $f \circ g$ is injective with the surjective condition of $g$:  Let $z_1, z_2 \in X \quad$ Because $z_1, z_2 \in X$ it is true that $z_1, z_2 \in g(y)$ thus: $$f \circ g(y_1) = f \circ g (y_2)$$ $$f(z_1) = f(z_2)$$ $$z_1 = z_2$$  So $f$ is injective.

If $g \circ f$ is injective, so is $g$   I don't think this is true. I think that $f$ has to be surjective.  So I am going to try to prove that:     If $g \circ f$ is injective, and $f$ is surjective, then $g$ is injective.   First off, $g \circ f$ means that $(g \circ f)(a) = (g \circ f)(b)$ then $a=b$.  And $f$ being surjective means that $\forall b \in B, \exists a\in A$ such that $f(a)=b$  Proof  Suppose that $g$ was not injective.  $g(f(a))= g(f'(a))$ and $f(a)\ne f'(a)$  But $g(f(a)) = g(f(b)) \to a=b$ $g(f(a))= g(f(b)) \to f(a)=f(b) \to a=b$ Hence contradiction, since $g$ is not injective.  So $g$ is injective.  Is this an acceptable proof, I think my logic is iffy around the second last paragraph.


I have configured Vhost on apache2.it is a name based configuration. First domain is ssl-secure and second one is non ssl-secure site.All are working fine if hit in browser address bar  and  . but if i try to access  and try to load with unsafe page1 is open while it not available on domain2.com.  if I check from ssl checker domain2 also get a same ssl certificate   My expectation is it should not load page1 because it is not exists.and also if check from ssl checker should not found ssl-certificate any more.How to prevent this please any one can guess. thanks in advance.  my configration is in available in folder "/etc/apache2/sites-available" example below domain1.com.conf  <VirtualHost *:80>      ServerName  domain1.com      ServerAlias www.domain1.com      DocumentRoot /var/www/domain1.com/public_html  </VirtualHost> <VirtualHost *:443>      ServerName  domain1.com      ServerAlias *.domain1.com      DocumentRoot /var/www/domain1.com/public_html      SSLCertificateFile "path/domain1_com.crt"      SSLCertificateKeyFile "path/domain1_.key"      SSLCACertificateFile "path/domain1.ca-bundle" </VirtualHost>   domain2.com.conf  <VirtualHost *:80>      ServerName  domain2.com      ServerAlias *.domain2.com      DocumentRoot /var/www/domain2.com/public_html  </VirtualHost>

Previously I asked a question here:  about setting up secure and non-secure domains on a single IP.  Opinions were mixed, but it appears SNI hold the solution. Unfortunately I cannot get it work as required.    — Works as expected  — Presents domaina.com certificate, not as expected. I would like it to not respond to SSL requests.   I would like my server to only send the certificate for domaina.com and no other host names, even if this means sending a 403 error to non-SNI clients. My current configuration on vanilla Ubuntu Server 12.04 LTS is below:  Ports.conf  … <IfModule mod_ssl.c>     NameVirtualHost *:443     Listen 443 </IfModule> …   Domain A Virtual Host  <VirtualHost *:80>     ServerName   domaina.com     ServerAlias  www.domaina.com     DocumentRoot /var/www/domaina.com/public     ErrorLog     /var/www/domaina.com/logs/error.log     CustomLog    /var/www/domaina.com/logs/access.log combined </VirtualHost>  <IfModule mod_ssl.c> <VirtualHost *:443>     ServerName   domaina.com     ServerAlias  www.domaina.com     DocumentRoot /var/www/domaina.com/public     SSLEngine on     SSLCertificateFile      /etc/apache2/ssl/domaina.com.crt     SSLCertificateKeyFile   /etc/apache2/ssl/domaina.key     SSLCertificateChainFile /etc/apache2/ssl/domaina.com.ca-bundle </VirtualHost> </IfModule>   Domain B Virtual Host  <VirtualHost *:80>     ServerName   domainb.com     ServerAlias  www.domainb.com     DocumentRoot /var/www/domainb.com/public     ErrorLog     /var/www/domainb.com/logs/error.log     CustomLog    /var/www/domainb.com/logs/access.log combined </VirtualHost>   apache2ctl -S  VirtualHost configuration: wildcard NameVirtualHosts and _default_ servers: *:443                  is a NameVirtualHost          default server domaina.com (/etc/apache2/sites-enabled/domaina.com:12)          port 443 namevhost domaina.com (/etc/apache2/sites-enabled/domaina.com:12) *:80                   is a NameVirtualHost          default server domaina.com (/etc/apache2/sites-enabled/domaina.com:3)          port 80 namevhost domaina.com (/etc/apache2/sites-enabled/domaina.com:3)          port 80 namevhost domainb.com (/etc/apache2/sites-enabled/domainb.com:1) Syntax OK   How can you get rid of the defaults?


One of things SE can do with our profiles is syncing. In fact there's a box called "Save And Copy Profile To All Stack Exchange Accounts". Why isn't the keyboard shortcuts part of this functionality? Is there any technical problem that can't be solved?

Following a global preference for , as of now, the preferences for enabling keyboard shortcuts and disabling the fixed topbar are network-wide* as well.  If you had either checked off on any site in the network, that setting has been preserved and applied to the whole network for your account already. Future changes will also apply to all* Q&A sites.  Find them in their usual spot as previously on the  pages.    * With the exception of , which will support the fixed topbar after the .


How does it follow from $\kappa < \kappa^{cf \kappa}$ that continuum $2^{\aleph_0}$ cannot be $\aleph_{\omega}$?   It is mentioned everywhere that it is obvious.

Question  Let $f:\;\mathbb{R}\to\mathbb{N}$ and let $X_n$ be the set of reals mapped to the integer $n$. Show that for some $n,\;X_n$ has cardinality of the continuum.    This is straightforward if we use König's theorem: assuming the contrary, i.e. $\left|X_n\right|<2^{\aleph_0}$ for all $n$:  $$2^{\aleph_0}=\left|\bigcup_{\mathbb{N}} X_n\right|=\sum_{\mathbb{N}}\big|X_n\big|\overset{\text{K.T.}}<\prod_{\mathbb{N}}2^{\aleph_0}=\big(2^{\aleph_0}\big)^{\aleph_0}=2^{\aleph_0}$$ a contradiction.    This feels overkill, but perhaps it is not. Am I missing a more elementary solution to this problem?


I am new at Latex, so Im sorry if I made things too complicated. I want to cite a website and @article probably isn't the best option for this, but here is what I tried:  @article{struers,   title={About Grinding and Polishing},   author={Struers - Ensuring Certainty},   isbn={},   url={https://www.struers.com/en/Knowledge/Grinding-and-polishing#},   year={2020}}  There wasn't a specific author mentioned in the website, but I want the name of the website to appear in references instead. Therefore I tried to put it as it was the author, but then it appears as this in the bibliography page: [2]  S. E. Certainty.  About grinding and polishing.  2020  while using: \bibliographystyle{abbrv}  So the question is, how can I make the websites name appear fully in references without messing up my other citations? Thank you :)

I want to list a company name in the author field of a bibliographic entry:  @book{CUDA,   author    = {NVIDIA Corporation},   title     = {NVIDIA CUDA Compute Unified Device Architecture Programming Guide},   publisher = {NVIDIA Corporation},   year      = {2007} }   But the entry keeps showing up "N. Corporation".  Is there a way to get the full author name to show up?  I'm currently using the siam BibTEX style.


Feynman writes:     One very important feature of pseudo forces is that they are always proportional to the masses; the same is true of gravity. The possibility exists, therefore that gravity itself is a pseudo force. ... It might seem all right to consider gravity to be a pseudo force, to say that we are all held down because we are accelerating upward... Einstein found that gravity could be considered a pseudo force only at one point at a time...   Now, how can gravity be a pseudo force? What did Feynman meant by saying this statement? Is gravity really a pseudo force? If so, why?

Einstein said that gravity can be looked at as curvature in space- time and not as a force that is acting between bodies. (Actually what Einstein said was that gravity was curvature in space-time and not a force, but the question what gravity really is, is a philosophic question, not a physical one)


Given two infinite series $A(x):=\sum_na_n(x)$, and  $B(x):=\sum_nb_n(x)$, suppose they have radius of convergence $r_1$ and $r_2$ respectively, then what is the radius of convergence of $\sum_n a_n(x)+b_n(x)$?  Is the region of convergence the intersection of the region of convergence of $A(x)$ and $B(x)$? I doubt that this is true by the ratio test.

I have  two series  $\displaystyle\sum_{n=1}^{\infty} a_n x^{n}$   $\displaystyle\sum_{n=1}^{\infty} b_n x^{n}$  with radius of convergence $2$ and $3$ respectively.  How can I find the radius of convergence for the following?     $\displaystyle\sum_{n=1}^{\infty} (a_n +b_n)x^{n}$   Can anyone help me?


I've never quite gotten this down. I think what this if statement does is allow a function to be run when it is called and not when the module that it is written in is imported. Take this code for example:  # Finds duplicate values in a specified feature class field and populates those reords with a 'Y' in another field  import arcpy  # enter program inputs def findDupes(inFeatureClass, checkField, updateField, countRec = 0):     with arcpy.da.SearchCursor(inFeatureClass, [checkField]) as rows:         values = [r[0] for r in rows]      with arcpy.da.UpdateCursor(inFeatureClass, [checkField, updateField]) as rows:         for row in rows:             if values.count(row[0]) >= 2:                 row[1] = 'Y2'                 print "yes"             rows.updateRow(row)             countRec += 1             print countRec if __name__ == '__main__':     fc = raw_input("paste input feature class path from ArcCatolog: ")      fld = raw_input("duplicate field values: ")     up = raw_input("update field: ")      findDupes(fc, fld, up)   the module arcpy is irrelevant for this question; however, the way I'm seeing things, if I put the raw inputs at the top of the script it would still run but if I imported the script with this function as a module (import CheckforDupes) it would run upon the import statement instead of when the function was called if the __name__ == "__main__" wasn't there. Is that right?

Given the following code, what does the if __name__ == "__main__": do?  # Threading example import time, thread  def myfunction(string, sleeptime, lock, *args):     while True:         lock.acquire()         time.sleep(sleeptime)         lock.release()         time.sleep(sleeptime)  if __name__ == "__main__":     lock = thread.allocate_lock()     thread.start_new_thread(myfunction, ("Thread #: 1", 2, lock))     thread.start_new_thread(myfunction, ("Thread #: 2", 2, lock))


I know how to build a rotation matrix around the x, y or z axis, but i'm not sure how to do it around an arbitrary vector.  For example, in R3, how should i build a rotation matrix with axis (111)? I read i should pick an orthonormal basis but i dont get why it cant be any R3 basis.  Also, i dont understand if a rotation matrix should always be an orthogonal (or hermitian) matrix. I mean, what if i define a linear transformation R as a rotation around the z axis, and apply a change of basis:  [R]b = Ceb.[R]e.Cbe  with R being the rotation matrix and Cbe the change of basis matrix from basis e to b. The resultant matrix wont be orthogonal but still is a matrix defining a rotation, isn't it?  Thanks!

Why does the following image equal what it equals?    Why does x,y,z equal that? 1/sqrt(3),1/sqrt(3),1/sqrt(3)


I am trying to add an image tag dynamically    var img = $('<img id="dynamic" class="removed">'); //Equivalent: $(document.createElement('img'))             img.attr('alt', "remove");             imageForm.append(img)   and where ever I have appended this one I want a click function  so I have written  $('.removed').on('click', function (e) {     console.log("e", e);     e.preventDefault(); });   But the event is not getting triggered. what should I do to fix this?

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.


I am wondering about the meaning and use of DO in "I do love you". Is it just an emphatic use that means "I really love you! I love you so!" or a contraditory statement:   You don't love me! You're wrong, I do love you!

Reading some books and posts I noticed that there are some semantice differences between constructions described in the title of this post. Could someone help me to find out what are the real difference and in which situations are better to use appropriate constructions?  I would be very grateful to hear the correct answer.


I'm trying to play with my sister. I have tried the same version, same WiFi and Ethernet cable, firewall changes, nothing works. I hope someone has an answer.

My LAN server won't let my cousin join me or me join my cousin. It won't show up on the multiplayer screen - it keeps saying "scanning for LAN servers" but it never finds it. I am at his house and we use different computers but it won't connect. How can I fix this?


I want to keep a few edges of my mesh straight and flat while making other parts of the mesh smooth and curved. How do I do that? I tried using catmull-clark but I can't choose what to subdivide and what not

How can I use the subdivision surface modifier to create more high poly meshes without ruining sharp edges? For example this mesh  The sphere should be subdivided but the rim of the cylinder should stay the same because it is a sharp edge. This is the result of the subdevision  How can I get sharp edges to not be affected by the sub surf mod?


I know with XP it was possible to remove Internet Explorer as a component, and it looks like Windows 8 made that even easier.  How is IE removed from Windows 10 and what are the ramifications?  see also:

Is there any possibility to completely disable the new Edge browser? The old IE could be disabled in Settings → Default Programs, but in Windows 10, the checkbox is missing for Edge.  Is there any way to get rid of Edge, or at least to disable all entry-points?


gcd$(x,y) = 1$ how can i prove that there exist $m, n \in \mathbb{Z}: mx+ny = 1$ I'm studying abstract algebra - cyclic group part, and wondering how $<d>$ is same group with $<r,s>$.

Given $a_1, a_2, a_3, \ldots , a_n$ not all zero, show $\gcd(a_1, a_2, a_3, \ldots , a_n)$ is the least positive integer that can be expressed in the form $a_1x_1+a_2x_2+ \ldots +a_nx_n$. Also deduce $a_1x_1+a_2x_2+ \ldots +a_nx_n = b$ has solutions $\iff \gcd(a_1, a_2, a_3, \ldots , a_n)|b$.   I know that $ax+by=n$ has integer solutions $\iff \gcd(a,b)|n$. I'll need to use induction to show $a_1x_1+a_2x_2+ \ldots +a_nx_n = \gcd(a_1, a_2, a_3, \ldots , a_n)$ has solutions, and then I will be able to say that as $\gcd(a_1, a_2, a_3, \ldots , a_n) | a_1x_1+a_2x_2+ \ldots +a_nx_n $ for any $x_1,x_2, x_3 \ldots x_n$ then $c \leq \gcd(a_1, a_2, a_3, \ldots , a_n)$ and $c \geq \gcd(a_1, a_2, a_3, \ldots , a_n)$, and thus $c=\gcd(a_1, a_2, a_3, \ldots , a_n)$.


I read that some of the portals that exist in Ingress are Pokéstops or Gyms in Pokémon GO. But are we talking only about the blue portals, or are the Neutral Portals (the grey ones) also Pokéstops/Gyms?

Pokemon go and ingress are both developed by the same company. Does Pokemon Go have same points (pokestops and gyms - portals etc.) as Ingress?


Claim: Prove that for every integer $n \geq 8$, there exist nonnegative integers $a$ and $b$ such that $n = 3a + 5b.$      Proclaimed solution : Let $n ∈ \mathbb{Z}$ with $n ≥ 8.$ $\text{ Then } n = 3q, \text{ where } q ≥ 3, \quad \text{ or } n = 3q+1, \text{ where } q ≥ 3, \quad \text{ or } n = 3q+2, \text{ where } q ≥ 2.$   We consider these three cases. (Rest of proof omitted)   I do not apprehend the above parts of the proof BEFORE (Rest of proof omitted). However, I understand and completed the rest of the proof that I omitted. I recognise that it uses the result that division of any integer by $n$ must yield a remainder of $0, 1, 2, ..., n - 2,  \text{ or } n - 1$.   $1.$ However, what is the idea or strategy of the proof?   $2.$ What motivates or propounds the claim?  $3.$ Is there a more natural or easier proof?  I referenced . Source: P102, Problem 4.9 on P101 (related to P90, Result 4.8) of Mathematical Proofs, 2nd ed by Chartrand et al.

I want to determine the set of natural numbers that can be expressed as the sum of some non-negative number of 3s and 5s.  $$S=\{3k+5j∣k,j∈\mathbb{N}∪\{0\}\}$$  I want to check whether that would be: 0,3, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and so on.  Meaning that it would include 0, 3, 5, 8. Then from 9 and on, every Natural Number. But how would I explain it as a set? or prove that these are the numbers in the set?


I created a responsive form which changes to two columns when the screen size is resized. It mostly works the way I want it to.   However the label for textarea keeps showing incorrectly. I want it to display on a new line, but it keeps showing in the area of radio buttons.   There is also an issue with radio buttons where both can be selected at the same time. I have been trying to figure out what I did wrong but I can't find a solution.      /* CSS */  .myForm {   padding: 40px 20px; }  .myForm h2, .myForm p {   text-align: center;   padding: 0 10px; }  .myForm h2 {   margin-bottom: 20px;   font-size: 20px;   font-weight: bold;   font-family: sans-serif; }  .myForm p {   margin-bottom: 20px;   font-size: 12px; }  .myForm label {   font-size: 14px; }  form input {   border: 1px solid #a9a9a9;   border-radius: 3px;   height: 25px;   width: 96%;   margin: 10px 0;   font-size: 14px;   padding: 5px; }  .label, .radio input[type="radio"] {   display: inline;   float: left;   width: auto;   margin: 10px 0;   padding: 0 10px; }  input[type="radio"], input.radio {   vertical-align: text-top;   width: 13px;   height: 13px;   padding: 0;   margin: 0;   position: relative;   overflow: hidden;   top: -8px;   right: 5px; }  .msg textarea {   width: 96%;   border: 1px solid #a9a9a9;   border-radius: 3px;   margin: 10px 0;   font-size: 14px;   padding: 5px; }  form button {   background-color: #a9a9a9;   color: #fff;   width: 100%;   text-transform: uppercase;   padding: 10px;   border: none;   border-radius: 3px; }  @media only screen and (min-width: 768px) {   /*Left form column*/   .left {     display: block;     float: left;     width: 48%;   }   /*Right form column*/   .right {     display: block;     float: right;     width: 48%;   }   .label,   .radio input[type="radio"] {     padding-right: 30px;     padding-left: 30px;   } }  <form class="myForm">
Lorem ipsum

text

     First Name               <input type="text" name="other">     Last Name               <input type="text" name="other">     text               <input type="text" name="other">     text               <input type="text" name="other">     text               <input type="text" name="other">     text               <input type="text" name="other">     text               <input type="text" name="other">
       Some text
                        <input type="radio" name="phone" value="phone">Phone                          <input type="radio" name="email" value="email">Email

       Message       <textarea rows="5"></textarea>

   <button type="button" name="button">Send</button> </form>

I have the age-old problem of a div wrapping a two-column layout. My sidebar is floated, so my container div fails to wrap the content and sidebar.

   There seem to be numerous methods of fixing the clear bug in Firefox:
 overflow:auto overflow:hidden   In my situation, the only one that seems to work correctly is the
 solution, which is a little bit scruffy. overflow:auto gives me nasty scrollbars, and overflow:hidden must surely have side effects. Also, IE7 apparently shouldn't suffer from this problem due to its incorrect behaviour, but in my situation it's suffering the same as Firefox.  Which method currently available to us is the most robust?


On my new computer, I didn't want to have /home on the system SSD but rather on the secondary drive which is a conventional hard drive.   I followed these instructions for moving /home to the other disk:   (actually )  But now I realize that the disk is NTFS format.    Will running home from NTFS be a problem, or perhaps a performance killer?   Can I convert the HDD from NTFS to ext3 (or ext4?!) without losing all the files, and how?

I use wubi to install Ubuntu 10.10 on my ntfs partition. So I want to change the home folder to a folder on the ntfs partition. I could keep the personal configuration, software and so on after reinstalling the Ubuntu.  So I use ntfs-config to manage the disk partition, it's mounted when system is startup. And the permission of all files and directories are 777.  Then I modified the /etc/passwd to set the home folder to the folder on the ntfs partition. I can successfully login the account, however it looks like the .bashrc and .profile are not loaded correctly. I can't use the input method(even can't configure ibus), no sound device. However everything works well after changing the home folder back to /home/.  Could anybody give me a hint to make it work? Thanks.


I may soon get enough reputation on Stack Overflow to see deleted posts. However, I don't want to see them! They probably were deleted for a good reason, and having them visible (e.g. while browsing through the answers for a question) is annoying. I got that feeling from another site where I have enough reputation to see deleted answers.  The pain is mostly (only?) about deleted answers; I don't remember seeing an annoying deleted question. But maybe these are annoying too (people with enough reputation will know).  Some users even try  to ease that pain for everyone.  Would it be good to not show the deleted posts by default, and provide some way for the users to "unhide" each post they want to see? Like show a small "unhide" button instead of the full answer.  (I am not making this into a [feature-request] because I don't have the details of the presentation that I want to suggest, just a general idea).

Today I exceeded 10K reputation on Stack Overflow, and I see deleted answers.  I am now faced with pages like  where half the answers are "deleted."    Among these are many non-answers deleted by diamond moderators, and a self-deleted answer deleted on Nov 25 '09.  I find this very distracting, especially in my chosen sort order of "oldest" where these deleted answers are NOT displayed at the bottom.  I wish to be able to hide deleted answers based on combinations of characteristics such as:   age since deletion deleted-by-owner deleted by diamond moderators zero undelete votes   This would be a setting every user could enable for himself.    Here are HTML excerpts that may be useful for userscript filtering.  This shows the code that appears for a moderator deletion, as well as the date stamp.
deleted by Dori♦ Jun 26 at 9:13
   Here is the same class for deleted by owner:
deleted by owner Nov 25 '09 at 19:12


I created a program in java and I want to know its CPU usage when it is being run. Is there any function? Can you help me please?  Thank you in advance!

I would like to monitor the following system information in Java:   Current CPU usage** (percent) Available memory* (free/total) Available disk space (free/total)  *Note that I mean overall memory available to the whole system, not just the JVM.   I'm looking for a cross-platform solution (Linux, Mac, and Windows) that doesn't rely on my own code calling external programs or using JNI. Although these are viable options, I would prefer not to maintain OS-specific code myself if someone already has a better solution.  If there's a free library out there that does this in a reliable, cross-platform manner, that would be great (even if it makes external calls or uses native code itself).  Any suggestions are much appreciated.  To clarify, I would like to get the current CPU usage for the whole system, not just the Java process(es).  The SIGAR API provides all the functionality I'm looking for in one package, so it's the best answer to my question so far. However, due it being licensed under the GPL, I cannot use it for my original purpose (a closed source, commercial product). It's possible that Hyperic may license SIGAR for commercial use, but I haven't looked into it. For my GPL projects, I will definitely consider SIGAR in the future.  For my current needs, I'm leaning towards the following:   For CPU usage, OperatingSystemMXBean.getSystemLoadAverage() / OperatingSystemMXBean.getAvailableProcessors() (load average per cpu) For memory, OperatingSystemMXBean.getTotalPhysicalMemorySize() and OperatingSystemMXBean.getFreePhysicalMemorySize() For disk space, File.getTotalSpace() and File.getUsableSpace()   Limitations:  The getSystemLoadAverage() and disk space querying methods are only available under Java 6. Also, some JMX functionality may not be available to all platforms (i.e. it's been reported that getSystemLoadAverage() returns -1 on Windows).  Although originally licensed under GPL, it  to , which can generally be used for closed source, commercial products.


My friend adoptive father's application has been refused:  You have applied to visit the UK for 3 days to visit your son. You state your named son is currently in the UK as a student. You have submitted adoption papers in support of your relationship, however Home Office records show in your named son’s most recent application for a UK visa, his father’s name is different to yours. The supporting information provided does not demonstrate your UK contact is expecting you on this visit or provide further detail on your relationship. You state you intend to spend £1000 (179,993DZD at £1 = 179.99DZD –  as of 31/12/2020) on this visit out of your own expense. You have submitted a bank statement in your name with account number ending 8886 with a balance of 32,661.73DZD (£181.46). I note deposits supporting a monthly pension income, however given the funds evidenced available I am not satisfied you have sufficient disposable funds to cover the costs of this visit. Given the above I am therefore not satisfied you have demonstrated that your circumstances are as declared or are as such that you intend to leave the UK at the end of your visit. This also leads me to further doubt your intentions in travelling to the UK. I am also not satisfied that you have sufficient funds to cover all reasonable costs in relation to your visit without accessing public funds. Your application for a visit visa has therefore been refused under paragraphs V4.2 (a), (c) & (e).  I now will write an explanation letter to explain that back to our home country we don't grant the family name to the adopted child due to some religious and traditional reasons. please can you give more ideas or solutions ?? and regarding the bank statement, he has created a bank letter and has put all his savings. Is this a good idea ?? Thank you so much

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


So I want to start a small Minecraft server to raise money toward a bigger one, so I download a Spigot server (and I have owned some servers in the past so I knew how to set it up). When I finish setting up port forwarding and all that crap, then when I start it up it says this:  **** FAILED TO BIND PORT!   So I went online to find how to fix it and I was met with a number of different methods. I tried changing the port, changing the IP, using the cmd, using task manager, closing Java, and then started it back up. I was met with the same message. I tried to fix again, but it still gave me the error.

I made a server and used my IPv4 address for the IP. I decided to scratch that server and make a Bukkit server so I can use plugins. I tried to use my IPv4 address which I used for my other server but I keep getting the message [17:31:15 WARN]: ****FAILED TO BIND TO PORT!  Is there any thing I can do to get a new address to use or is there a way to delete the old server? Do I need to use a different computer? Please help! I've don't know how to fix this problem. If you have any suggestions please tell me and I'll give it a try.


Experiment: flip a coin until you get Heads. I would like to understand better why $E=(T,T,T,....)$, the event where heads is never flipped, is part of the sample space.   Isn't the experiment going on forever unfinished in that case? Whereas if someone asked if $(T,T,T)$ were an element of the sample space, the answer would be no, because elements of the sample space must look like $(T,T,...,T, H)$ or  by exactly $E$.   To clarify, is $E$ an element of the sample space of this experiment (I claim it is). If so, can you explain why?  Thanks.

Suppose we're considering the problem of flipping a coin until "heads" comes up.  The sequences H, TH, TTH, TTTH, ... are all part of the sample space we need to consider.  But what about the sequence TTT... (infinitely many tails)?  I would think that this "event" should be excluded by definition, because our experiment doesn't end until "heads" comes up.  Nonetheless, one could imagine a scenario where "heads" never comes up.  So when should we include TTT... in our sample space, and in doing so, what does that "buy" us?


i have a site, nartrade.az which is indexed by google. it appears on google search in my country(Azerbaijan). but when i search from different countries(i.e Turkey) on google, it doesn't appear on google search. what could cause this issue? and how can i solve this issue?

I have a sight hosted on .ie domain but it is near the NI(Northern Ireland) border and the business has a lot of NI traffic. So when someone searches in NI with certain key words I would like the site to appear in the results, it currently doesn't.   I have seen this post    But was wondering the best way around this. Would it be to create a .co.uk version that redirects to the .ie site? Or would I have to create a separate .co.uk site?  Any help appreciated thanks.


I am on the latest Ubuntu and I’ve looked at similar questions and tried everything they’re saying and nothing is working for me and my cpu is kinda old tho

Basic System specs:   Samsung SSD 500GB CPU: Intel i5-7500  RAM: 16GB GPU: NVIDIA GeForce GTX1080 Currently configured to Dual Boot with Windows 10 64bit, but Windows boots without any havoc.   Issue:  Ubuntu 16.04 hangs in boot splash screen indefinitely, but after trying to fix it, now it successfully boots into shell mode. In addition, even pressing on ESC when it hangs doesn't display any logs.  So I couldn't see the boot log other than SSHing into my desktop, and open /var/log/boot.log  Here's what I got, while it was hanging:  [  OK  ] Started Network Manager Wait Online. [  OK  ] Reached target Network is Online. [  OK  ] Started Daily apt download activities. [  OK  ] Started Daily apt upgrade and clean activities. [  OK  ] Reached target Timers. [  OK  ] Started crash report submission daemon.          Starting /etc/rc.local Compatibility... [  OK  ] Started /etc/rc.local Compatibility.          Starting Terminate Plymouth Boot Screen...          Starting Hold until boot process finishes up...   I also tried dmesg | less after numerous googling to view the boot logs, and encountered into this at the end of it:  [    2.604476] random: crng init done [    2.631750] IPv6: ADDRCONF(NETDEV_UP): enp2s0: link is not ready [    2.651404] r8169 0000:02:00.0 enp2s0: link down [    2.651432] r8169 0000:02:00.0 enp2s0: link down [    2.651488] IPv6: ADDRCONF(NETDEV_UP): enp2s0: link is not ready [    2.691320] NVRM: Your system is not currently configured to drive a VGA console                on the primary VGA device. The NVIDIA Linux graphics driver                requires the use of a text-mode VGA console. Use of other console                drivers including, but not limited to, vesafb, may result in                corruption and stability problems, and is not supported. [    2.861207] input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input14 [    2.861248] input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input15 [    2.861281] input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input16 [    2.861312] input: HDA NVidia HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input17 [    5.426350] r8169 0000:02:00.0 enp2s0: link up [    5.426356] IPv6: ADDRCONF(NETDEV_CHANGE): enp2s0: link becomes ready   It seems like there is an issue with the NVIDIA card as I initially thought.  What I have done to fix this problem:   Update GRUB   Went to recovery mode and open terminal Changed the boot mode from quiet splash to acpi=force to force the boot into shell, now I rolled that back. cat /etc/X11/default-display-manager reveals lightdm as the default.  Update Intel video card driver I tried using boot-repair to fix grub issues, and the results are as such on pastebin:    What I might have done to cause this problem:   sudo service lightdm stop   In an effort to attempt controlling the GPU fan headlessly. But I ran sudo service lightdm restart Now I believe lightdm doesn't start up at boot. Here is the  I followed to control GPU fan remotely  sudo service lightdm restart   I tried restarting lightdm, and it does give me some positive output which is the login screen, but I can't do anything here as it is still frozen.  I try typing stuff on the keyboard but nothing shows up.    Can someone please help me figure this out??? I am really clueless and about to cry....


I plan to go US, Can I take my portable charger( lilon battery, portable power bank) to the airplane? the capacity is .Different countries make rules about whether Power Banks are allowed to be used on flights or not so please tell me.

When flying, are you allowed to bring battery packs / power banks? I'd like to bring my ACC 10400mAh Power Bank on several flights.


How do I factorize this thing? $x^4+x^2+1$ I tried to solve the integral $\int{\frac{1}{x^4+x^2+1}}$ and after trying some substitutions that did not work, I plugged the integral into an integral calculator and it turns out that $x^4+x^2+1$ can be written as $(x^2-x+1)(x^2+x+1)$ and at first I thought it was factorized using the formula $(a-b)(a+b) = a^2 - b^2$ where $a = x^2$ and $b = x+1$ but after trying that I realized it is wrong because $b = -(x-1)$ in the first parantheses and in the second $b = x+1$.  So what is the intuition behind this factorization?

By viewing the polynomials as a difference of two squares, factorise the following polynomial: $$x^4+x^2+1.$$ I searched but couldn't find a way to solve this  Edit: By using Hans Lundmark hint, I get:  $$(x^2+1)^2-x^2$$   Is it fully factorized?


I know that there is  question on here about the theory of R+L=J, but there ought to be a question on here for the arguments against. (Spoilers all, to be safe)  What evidence from ASOIAF suggests that Rhaegar and Lyanna are not the parents of Jon Snow?

I've heard speculation that Jon Snow's actual parents may be Rhaegar and Lyanna Stark, but in reading the books I'm not sure what evidence could be used to support this conclusion.  I thought there might have been something in the conversation Davos had before being smuggled into White Harbor, but I couldn't stretch anything that far.  What evidence do proponents of this theory cite?  Does any of it involve stuff in the texts or just sweeping generalizations of the characters' personalities (e.g. "Ned Stark is too honorable to father a bastard").


If we taste with our smelling sense, and in the process of cooking aroma is being released into the air - does that mean that the more smell you fill your kitchen with, the more flavor you lose?  Is the iconic experience of aroma filled kitchen actually counterproductive to cooking flavorful food?

This is a maxim that I hear frequently, especially as a defense of cooking methods that don't produce a lot of aroma: if the aroma is in the air, it means it's left the food.  As an example, some people complain about the lack of aroma produced in sous vide cooking, to which the sous vide advocates retort that this is evidence that more flavor is in the food.  Likewise, I recently saw , where he went for a low-and-slow approach that produces little aroma: here, too, he claimed the flavor-retention defense to its lack of appeal. "Don't be disappointed, but my roasting technique doesn't flood your kitchen with good Sunday roast smells. This is a good thing, because smells are lost flavor" he said, while "SMELL = LOST FLAVOR" popped up on the screen.    I suppose it stands to reason, and that's the appeal of this explanation, but is it the truth? Does smelling a food necessarily imply that the final product will be less flavorful, and is it strictly because the aroma is escaping?


I have a problem in installing SharePoint foundation 2013 on my Window Server 2012 R2. When i run SharePoint Product Preparation tool , i am getting error like "the tool was unable to install application server and web server (IIS) role.". please someone help me to out of these problem

I'm trying to install the Prerequisites by running the prerequisiteinstaller.exe but i'm stuck at this Application Server Role, Web Server (IIS) Role: configuration error    I have tried the following:   Do windows update (done with about 60 somthing MB) Adding the roles manually through Server Manager but it turns out that they already been added! Failed with installing KB 2771431, got this msg The update is not applicable to your computer. Tried to do the alternative method Method 2 as mentioned  and also nothing happened    I'm running this test environment on VMWare with 8 G.B of RAM and 120 G.B Hard drive capacity  Please suggest.


I sell bread at farmers markets. It gets moldy very fast. How can I get them to last longer?

I love making our own bread - we rarely buy shop bought, but it tends to go off very quickly. Part of the appeal is that it doesn't have any "junk" in it - artificial preservatives - which I'm sure contributes to the lovely flavor. Is there anything natural I can add to it to stop it going moldy so fast?


I am not a scientist, so that's why I've come here...to hopefully find out if this would be possible.  Ok, so I started learning about quantum entanglement and I stumbled upon an idea for instant data transmission through space.  The idea is fairly basic,  because quantum entangled particles are dependent on each other to create 1 shared state...(I think) we could separate two entangled particles and then modify one to create an instant change on the other particle.  This change would be read and computed as binary code 1-0-0-1-1-0-1-0 for example.  Here's the best way i can explain my theory,     Simply put as one question, is instant data transmission possible in this way? Or at least faster than light (laser arrays)?

Quantum entanglement is 2 atoms that are paired together and when you stop one from spinning the other also stops with the same spin. Can you use these pairs to have faster-than-light (FTL) communication between 2 computers?


This book featured something called "The Labyrinth" that was a kind of maze that opened into other worlds.  There was one world where all the men were stupid and used as sex objects.  There was a drug that had to be taken regularly by pressing/popping a bead of it onto your skin, and it got into one woman's brain and corrected her eyesight.  I read this book in about 2005.  Does anyone recognise this book?

Looking for a book. A series,  actually.  The main characters were a Jewish man and a black woman who was his wife. There was a running gag when she would tell people her last name and they thought it was unusual that a black woman would have a Jewish name.    They went on adventures in parallel dimensions. I believe that each book had a word repeated in the title, maybe "mirror?" Or "maze?" Or "page..."  it seems they jumped into worlds through a tool like a mirror or a book.   The parallel universes were like pages, and the pages closest to you were most similar but the further you got the further they were from your life.  One page over might be that you had something different for breakfast and so now you have a tummy ache, a few more pages over you might have become a prostitute, too far and it was theorized that humans had evolved differently altogether, I didn't get that far in the series.  For adults, and humorous.  I read them about 15 years ago, so they are not new. I would love to find them again.


Dear all,  I have a problem with justifying text. The last word in a sentence, for example "Keynesian" is cut into "Key-" at the end of the first sentence and "nesian" at the beginning of the following sentence.   As I send the paper for review, some reviewers do not agree with this presentation. How can I still justify the text but keep the whole word?   Thanks for your comments. Another example to illustrate the problem. If I add some letter before "Keynesian", as you can see, the word "Keynesian" jumps to next line without being splitting.

I can't find where I can remove any kind of hyphenation and just have LaTeX just do a line break.  edit: Honestly speaking I just don't like to read hyphenation anywhere and that's the only reason why I wanted to remove it. It is a matter of style, probably unexpected in LaTeX.  The document has only a summary in a different language and I used the language packages to hyphenate properly.


A neutral hydrogen atom is composed of a proton and an electron.  The overall charge on the atom is zero but there are local charges within the atom as the negative and positive charge is not evenly distributed.  If a neutral hydrogen atom were placed in an electric field the electron and the proton would experience a force in opposite directions.  Could a strong enough electric field tear the electron and proton apart?

I was thinking one day and came up with a theory after reading about how scientists were studying anti-matter by using electro magnetic fields to separate matter from the anti-matter they made.  It got me thinking would it be possible to use very powerful electromagnetic fields to break down the atomic structure of objects or build things in this way?  Is this atomic reconstruction with electromagnetic fields theoretically possible? That is, is it theoretically possible to use electromagnetic fields generated by a machine to separate the parts of an atom thereby deconstructing an object on the atomic/subatomic level?  I'm not asking about breaking molecular bonds but rather actual atoms apart.  If it's possible to break atoms apart with electromagnetic fields, is it also possible to use a similar process to assemble them?


Is it wrong to say $$ \sqrt{x} \times \sqrt{x} =\sqrt{x^2}= \pm x$$ I am quite sure that  $\sqrt{(x)^2} = \pm(x)$  But, does $\sqrt{x } \times \sqrt{x} =- (x)$ doesn't holds in $\mathbb{R}$ but if we assume $\mathbb{C}$ it holds right?


I am running multiple (37) Kruskal wallis tests to check if there is a difference between three disease groups. I do this using groupby in R to group all the 37 groups. Then for each group I check the p-value of the Kruskal wallis and then decide to do a post hoc. Do I need to correct for these 37 tests (representing 37 groups) or do I just carry out the correction in my post hoc tests - ie a BH adjustment in the Dunns test?

I am running a kruskal wallis test a number of times (37) and wanted to know if I have to adjust the p-values of the kruskal tests before I look any further into the post hocs?


Is there any way to write a binomial coefficient that has brackets in place of parenthesis?  Another way to write what I want would be to get a fraction without the horizontal bar between the denominator and the numerator, and then surround it with big brackets, but is this possible?

What is the best way to write a ? Isn't there any standard command in LaTeX? For example, a command \binom is for binomial coefficients.  In the wikipedia article on Stirling number of the second kind, they used \atop command. But people say \atop is  recommended.


Write a query to display the student names and the maximum mark scored by them in any subject, ordered by name in ascending order. Give an alias to the maximum mark as MAX_MARK. I am not able to find the logic for this. Kindly help me with it. Do it in oracle SQL I am at beginner level in SQL. SELECT MAX(M.VALUE), S2.SUBJECT_ID,M.STUDENT_ID, S2.SUBJECT_NAME,S2.SUBJECT_CODE from Mark M INNER JOIN SUBJECT S2  ON M.SUBJECT_ID=S2.SUBJECT_ID group BY S2.SUBJECT_ID,  S2.SUBJECT_CODE, S2.SUBJECT_NAME;  I am getting error with this query if I get this student id with the help of the above query then I can easily solve this question using subquery concept.

Table:   UserId, Value, Date.   I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL? (Preferably Oracle)  Update: Apologies for any ambiguity: I need to get ALL the UserIds. But for each UserId, only that row where that user has the latest date.


I received an error message when I tried to join the Super User community.  I followed some instructions  and fixed the issues with my profile. However, I'm still with only 1 reputation point on Super User.  Unlike the linked question, the issue I'm mentioning didn't happen at any point when several users were having this problem. So after 24 hours I don't have much hope that my reputation issue will be solved automatically.  What should I do to get SE to give me the 100+ rep bonus on Super User?  (By the way, I'm aware that issues should be addressed first in the respective communities, but I don't have enough reputation to bring this issue in the Super User meta.)

I'm a long time user with more than 1500 rep on the main site I visit. I have recently joined the physical fitness beta site and .   I believe this is a bug in the beta portion of the site. I have gotten the association bonus on all other sites I have joined.


Given a differentiable function $f$ such that  $$ \lim_{x \to +\infty}f'(x) = 0 $$ what can we say about $$ \lim_{x\to\infty}(f(x+1)-f(x)) \text{ ?} $$ My first thought was to use mean value theorem on $[x,x+1]$, and I will get that the limit is $0$, is this true? Thank you for your help.

Having some trouble proving this:     If $f:\mathbb{R}\rightarrow \mathbb{R}$ is differentiable and $\lim_{x\to \infty } f^\prime(x)=0$ show: $\lim _{x\to \infty } (f(x+1)-f(x))=0$   Attempt: from $\int \lim _{x\rightarrow \infty } f^\prime(x) \mathrm{d}x=0$ we can say that $f^\prime(x)=const$ would we then have to show that  $\lim _{x\to \infty } (f(x+1))$ is also a constant? From there if we show that both are equal then the difference is zero. I am on the right track?  Thank you for the help.


You have a standard deck of cards and randomly take one card away without looking at it and set it aside. What is the probability that you draw the Jack of Hearts from the pile now containing 51 cards?      I'm confused by this question because if the card you removed from the pile was the Jack of Hearts then the probability would be zero so I'm not sure how to calculate it.    Edit: I asked this question about a year ago because I was struggling to get an intuitive understanding of an important concept in probability, and the comments and answers were really helpful for me (especially the one about "no new information being added so the probability doesn't change").

I have this task about cards:     Consider choosing a card from a well-shuffled standard deck of 52   playing cards.           Suppose that, after the first extraction, the card   is not reinserted in the deck. What is the probability that the second   card is an ace?   Suppose that, after the first extraction, the card   is reinserted in the deck. What is the probability that the second   card is an ace?      For the first case, I've been thinking about $$\left(\frac{4*3}{52*51}\right) + \left(\frac{48*4}{52*51}\right)$$ Where I counted two examples: a)the ace was drawn already, and b) it wasn't. For the second part of the task, would it be $$\left(\frac{4*4}{52*52}\right) + \left(\frac{52*4}{52*52}\right)$$ I'm pretty sure that I'm assuming wrong, but I can't come up with anything else. Any help would be great!


I am experiencing a rather weird issue. I am using some citations in a document and surprisingly some items are not parsed. My code is  \RequirePackage{filecontents} \begin{filecontents*}{cite.bib}  @article{Chiari,     author    = "M. Chiari, L. Giuntini, P.A. Mando, N. Taccetii",     title     = "Proton elastic scattering cross-section on boron from 0.5 to 3.3 MeV",     journal   = "Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms",     volume    = "184",     number    = "3",     pages     = "309-318",     year      = "2001",     month     = "November", hyphenation={english}  }  @article{Mayer, title = "The $^{11}B\left(p,\alpha_0\right)^8Be$ nuclear reaction and $^{11}B(p,p)^{11}B$ backscattering cross sections for analytical purposes ", journal = "Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms ", volume = "143", number = "3", pages = "244 - 252", year = "1998", note = "", issn = "0168-583X", doi = "http://dx.doi.org/10.1016/S0168-583X(98)00383-8", url = "http://www.sciencedirect.com/science/article/pii/S0168583X98003838", author = "M. Mayer and A. Annen and W. Jacob and S. Grigull", hyphenation={english} }  @article{Rihet, title = "States in $^{12}C$ from resonant proton scattering ", journal = "Journal de physique ", volume = "38", number = "1", pages = "17 - 19", year = "1977", % note = "", issn = "0168-583X", doi = "http://dx.doi.org/10.1051/jphys:0197700380101700", url = "http://jphys.journaldephysique.org/articles/jphys/abs/1977/01/jphys_1977__38_1_17_0/jphys_1977__38_1_17_0.html", author = "Y. Rihet, A. Genoux-Lubain, H. Beaumevieille, R. Seltz, C. Gerardin,  D. Magnac-Valette ", hyphenation={english}  }  \end{filecontents*}  \documentclass[11pt,a4paper]{book} \usepackage[english,greek]{babel} \usepackage[utf8]{inputenc} \usepackage{kerkis} \usepackage[bibencoding=auto,backend=biber,babel=other]{biblatex} \addbibresource{cite.bib} \renewbibmacro{in:}{} \newcommand{\eng}[1]{\latintext#1\greektext} \newcommand{\gre}[1]{\greektext#1\latintext}  \begin{document}  το ενεργειακό και γωνιακό εύρος(\cite[\eng{Chiari}]{Chiari}) καλύπτουν για την γωνία των $120^\circ$ τις ενέργειες $2250,2800\;keV$ για το $^{11}Β$ (\cite[\eng{Mashkarov}]{Mashkarov}, \cite[\eng{Dejneko}]{Dejneko}) και όλο το ενεργειακό εύρος  για το $^{10}Β$ (\cite[\eng{Overley}]{Overley}). στην ενέργεια των $3300keV$(\cite[\eng{Rihet}]{Rihet}). Τέλος, λόγ $2250\;keV$(\cite[\eng{Mayer}]{Mayer}). Η επιλογή των εν λ \cite[\eng{Mayer}]{Mayer} και \cite[\eng{Chiari}]{Chiari}, οι οποίες είναι πειραματικές, η απόδειξη της μη έντονης  γωνιακής εξάρτησης φαίνεται από τα δεδομένα του \cite[\eng{Chiari}]{Chiari}. \printbibliography \end{document}   and my output is    My compilation process is   pdflatex -shell-escape file.tex biber file pdflatex -shell-escape file.tex   Any idea on why is this happening and how can it be fixed?

I'm using Jabref to manage my Bibliography.  Sometimes, I put directly:     First Author et al.   when adding the article author's name in Jabref.  When compiling my .tex file, LaTeX doesn't recognize the et. al as more names. It takes it as a name/surname.  This is an example of a Bibliography entry in Jabref.  @ARTICLE{Wolf2003,     author = {Wolf, K.et al.},     title = {Compensation mechanism in tumor cell migration: mesenchymal–amoeboid     transition after blocking of pericellular proteolysis},     journal = {J. Cell Biol.},     year = {2003},     volume = {160},     pages = {267–277},    }   This is a .texMWE with the bib entry mentioned:  \documentclass[11pt]{book}   \usepackage{cite}   \bibliographystyle{unsrt} \begin{document}   Here is the bib entry mentioned\cite{Wolf2003}    \bibliography{bibfile}  \end{document}   Here's the output:   How can I solve this problem?


I'm trying to write a "ClickerGame" that the user need to click on a button as much as he can in 1 min.  Can you help me to improve the functionality of this program? it's not really working.  import javax.swing.*;  import java.awt.FlowLayout; import java.awt.event.*; import java.awt.*; import java.lang.*; import java.util.Date;  public class ClickerGame extends javax.swing.JFrame {     int i,j;     JPanel panel;     JFrame frame;     JButton start;     JButton stop;     JButton click;     JTextArea text;     JLabel label;     public static void main(String[] args){         ClickerGame a = new ClickerGame();         a.go();     }      public void go(){          frame = new JFrame();          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);           JPanel panel = new JPanel();           click = new JButton("Click");          click.addActionListener(new ClickListener());           start=new JButton("Start");          start.addActionListener(new StartListener());           stop=new JButton("Stop");          stop.addActionListener(new StopListener());          panel.add(start);          panel.add(click);          panel.add(label);          frame.getContentPane().add(BorderLayout.CENTER,panel);           frame.setSize(500,500);          frame.setVisible(true);     }     class ClickListener implements ActionListener{         public void actionPerformed(ActionEvent event){              click.setText("Number of clicks: "+i);             i++;         }          }      Timer timer = new Timer(1000,new ActionListener(){         public void actionPerformed(ActionEvent e){             Date currentTime = new Date();             label= new JLabel(currentTime.toString());           }     });      class StartListener implements ActionListener{         public void actionPerformed(ActionEvent event){             timer.start();         }     }     class StopListener implements ActionListener{         public void actionPerformed(ActionEvent event){             timer.stop();         }     }  }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?