I'm trying to separate common concepts of time from the use of time as a standard measurement in physics.  One thing I'm struggling to define is the "rate of the passage of time". For example, commonly we might say that something happens, or has the rate of, "every day". But "every day" isn't a rate "of time".  Let's use the example of a CPU clock "speed". "Speed" is loosely defined in physics as the distance traveled per unit of time. In the case of CPU clock speeds, the speed is the number of clock cycles the CPU can perform per second. But a second isn't a measurement of time. A second is a measurement of the rotation of the Earth. Therefore, the CPU clock speed is more accurately defined as, "the number of clock cycles the CPU can perform in 1/86,400th rotations of the Earth". It's simple substitution. The second is a portion of a minute, is a portion of an hour, is a portion of a day. A day is defined as 1 rotation of the Earth. Any relationship that the rotation of the Earth has to another "dimension" or "force" called "time", seems to be an assumption.  According to my understanding of physics, the current belief is that "time" is passing at varying rates "all the time" depending on different circumstances. "Time is passing more slowly" for objects that are larger (or vice-versa) or time is passing more quickly for objects that are experiencing more gravity (or vice-versa). So, if we've had this assumption that the Earth's rotation happens at a constant rate of the passing of time, which rate of passing time have we been... standardizing the Earth's rotation against? If 1 rotation of the Earth is equal to x units of a force called time "passing by", then are we using the rate at which time passes when it's experiencing more gravity or less gravity?  So, my conclusion thus far is that we've just been confusing time with the relatively constant motion of physical objects. Like two lights blinking at different but consistent rates. They don't blink in rates of time, they blink in rates of each other, because each of them is relatively constant. The fast light blinks 3 times for every 1 blink of the slow light. And somehow we've assumed that there's a third underlying force which is also passing by at a consistent rate where really none exists.  So, what instrument have we used to measure the rate at which a fourth dimension passes by? We have devices that compare the rates of one object in the three dimensional world with the rates of other objects in the physical world, but as far as I can tell we're always comparing the rate of one object in the three dimensional world against the rate of another object in the three dimensional world. I can't tell where a 4th dimension fits into the equation. Examples:  Carbon 14 has a half life of 5,730 revolutions of the Earth around the Sun.  The gestation period for a human baby is approximately 252 rotations of the Earth.  2,091,450 rotations of the Earth is approximately the half life of a Carbon 14 atom.  At this point Microsoft Excel would throw a "Circular Reference" error. What is physics doing differently?

This is an attempt to gather together the various questions about time that have been asked on this site and provide a single set of hopefully authoritative answers. Specifically we attempt to address issues such as:   What do physicists mean by time? How does time flow? Why is there an arrow of time?


I have a problem with my brightness setting. When I decrease brightness to 1 and I reboot the computer, it reset to maximum brightness value. I tired to adjust it and decrease it again to 1. Why the setting doesn't save the last brightness setting for me? How can I save the current value and restore it after reboot via programming?  I also tried to add echo 0 > /sys/class/backlight/intel_backlight/brightness in /etc/rc.local file, but after rebooting, it reset to the maximum again.   My laptop model is Vaio SVF1521DCXW.

The brightness of my laptop is reset to max on every restart. I tried the solution provided at  but had no luck.   This command   cat /sys/class/backlight/acpi_video0/max_brightness   Returns   cat: /sys/class/backlight/acpi_video0/max_brightness: No such file or directory   Then I found that I don't have a folder named acpi_video0, but a folder called intel_backlight:    Every time I increase or decrease the brightness using the brightness control keys, the values in brightness and actual_brightness get updated.  Is there any method I could follow to set the brightness to a fixed value on every boot and vary it as and when I need it using the brightness control keys?


I need certain patterns on a particular texture to be glossy while everything else remains rough. Any ideas? It more like a golden yarn embroidered on a black linen.

I have a skyscraper building but I only want the glass in the texture to be glossy.  How would I accomplish this?    Ok, I have done a test and here are the results.  Here is the original:   here is an adjusted image


How do I delete secure search (AVG virus) malware?  I am using Firefox as my browser. I am able to bypass it when it appears on start up, but I cannot find and completely remove this irritation?

I am running a Dell laptop computer with a Windows 7 Professional operating system.  I have Google Chrome and Internet Explorer installed.  When I open Internet Explorer the home page I get is a website that says 'AVG Secure Search'.  I want to delete this.  How can I do so?  I had this problem once before, maybe six months ago, and was able to solve it myself after several hours of effort.  This time I cannot find a solution.  If I type 'remove AVG Secure Search' into Google I find a lot of websites describing this problem, but none offer a clear and effective solution.  Many of those websites are by AVG themselves, but their proposed solutions are not helpful to me.  For example,  says:  Step 1. Open Internet Explorer  Step 2. Click 'Tools' on the top menu, and then click on 'Manage Add-ons'.  Step 3. In the opened window, click on 'AVG Security Toolbar', and then click on 'Disable' at the bottom right corner.  However, on my computer AVG does not appear in the opened window.  The default open window is for 'Toolbars and Extensions', which has a small red circle with a red diagonal line in it, suggesting to me that something is disabled.  If I click on 'Search Providers' instead of 'Toolbars and Extensions', then 'AVG Secure Search' is listed.  If I click on 'AVG Secure Search' then a 'Remove' button appears in the lower right corner of the window, but this 'Remove' button is grayed out and I cannot click on it.   I have explored other websites purporting to provide assistance in removing AVG Secure Search, but these other websites often seem to recommend downloading and installing various applications with which I am not familiar.  Nor does 'AVG' appear anywhere in the listing under 'Programs and Featured' under the 'Control Panel'.  I have also checked other posts here on SuperUser that mention AVG, but have not found a post that provides clear instructions on how to remove AVG Secure Search.  Thank you for any advice.  If I locate a way to remove this search engine myself, I will post the solution here.  (I am using the AVG-antivirus tag, although as far as I know I do not have AVG antivirus software on my computer.  At least, I never knowingly installed it to the best of my recollection.)


I use Heroku as my hosting solution. So, if some bad man attacks my site with DDoS, what should I do?

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


I have multiple files in a directory:  $ ls -1 04PD.001 04PD.002 04PD.003 04PD.004 04PD.005   Now I'd like to change the name of each file to something like 04PD.7z.0*  Can someone tell me what's wrong with that command:  $ find 04PD* -type f -print -exec mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \;   The result is utmost strange:  $ find 04PD* -type f -print -exec mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \; 04PD.001 mv: '04PD.001' and '04PD.001' are the same file 04PD.002 mv: '04PD.002' and '04PD.002' are the same file 04PD.003 mv: '04PD.003' and '04PD.003' are the same file 04PD.004 mv: '04PD.004' and '04PD.004' are the same file 04PD.005 mv: '04PD.005' and '04PD.005' are the same file    To test the command I changed the command to simple echo:  $ find Pop*04PD* -type f -print -exec echo mv \{\} `echo \{\} | sed "s/04PD\.0/04PD\.7z\.0/"` \; 04PD.001 mv 04PD.001 04PD.001 04PD.002 mv 04PD.002 04PD.002 04PD.003 mv 04PD.003 04PD.003 04PD.004 mv 04PD.004 04PD.004 04PD.005 mv 04PD.005 04PD.005   Note: I've already found a very nice & simple solution with a loop, so please focus on what's wrong with this command, rather that proposing another solution.  I am pretty curious where the error is.

It looks like 'find', 'bash' and 'sed' in some cases does not work as one expects.  The following example should first create file 'sample.txt', then find the file and finally process it by '-exec' command. The executed command prints found filename, test specimens, and modified filename. The 'sed' command itself is used to replace 'txt' to 'TXT'.  touch sample.txt find ./ -maxdepth 1 -name "*.txt" -exec echo {} $(echo Specimen_before.txt {} Specimen_after.txt |sed -e "s/txt/TXT/g") \;   The expected output is:     ./sample.txt Specimen_before.TXT ./sample.TXT Specimen_after.TXT   Instead it produces:     ./sample.txt Specimen_before.TXT ./sample.txt Specimen_after.TXT   (the example has been tested also with old-school command substitution through backquotes '`' with the same result)  What am I doing wrong?


Is there a simple way to flatten a list of iterables with a list comprehension, or failing that, what would you all consider to be the best way to flatten a shallow list like this, balancing performance and readability?  I tried to flatten such a list with a nested list comprehension, like this:  [image for image in menuitem for menuitem in list_of_menuitems]   But I get in trouble of the NameError variety there, because the name 'menuitem' is not defined.  After googling and looking around on Stack Overflow, I got the desired results with a reduce statement:  reduce(list.__add__, map(lambda x: list(x), list_of_menuitems))   But this method is fairly unreadable because I need that list(x) call there because x is a Django QuerySet object.  Conclusion:   Thanks to everyone who contributed to this question.  Here is a summary of what I learned.  I'm also making this a community wiki in case others want to add to or correct these observations.  My original reduce statement is redundant and is better written this way:  >>> reduce(list.__add__, (list(mi) for mi in list_of_menuitems))   This is the correct syntax for a nested list comprehension (Brilliant summary !):  >>> [image for mi in list_of_menuitems for image in mi]   But neither of these methods are as efficient as using itertools.chain:  >>> from itertools import chain >>> list(chain(*list_of_menuitems))   And as @cdleary notes, it's probably better style to avoid * operator magic by using chain.from_iterable like so:  >>> chain = itertools.chain.from_iterable([[1,2],[3],[5,89],[],[6]]) >>> print(list(chain)) >>> [1, 2, 3, 5, 89, 6]


$$f(x,y)=\begin{Bmatrix} 0 & (x,y)=(0,0)\\   \frac{xy}{x^{2}+y^{2}}&(x,y)\neq (0,0)  \end{Bmatrix}$$   How to find out if this is continuous?  And do the partial derivatives exist at $(0,0)$?

I am aware there are many questions similar to this on MSE but I am having trouble following any of the solutions given.   I have the function given by   $f(x) = \dfrac{xy}{x^2+y^2}\;$ for $(x,y)\neq (0,0)$ and $f(0,0)=0$  I have calculated the partial derivatives and found:   $$\frac{\partial f}{\partial x} = \frac{y(-x^2+y^2)}{(x^2+y^2)^2}, \quad \frac{\partial f}{\partial y} = \frac{x(-y^2+x^2)}{(y^2+x^2)^2}$$  Now I need to show the partial derivatives exist for $(x,y) = (0,0)$.  I am also asked to show it is not continuous at $(x,y)=(0,0)$, based on other answers I've seen it seems like this follows from solving the first part but I fail to see how that follows through as well.   I could just copy the solutions with my function in place as I have seen a lot of answers using the definition of the derivative, but realistically I do want to understand what the thinking behind this is.   Any help would be appreciated.


Which one would be better to use in the following sentence? How can I know in the future which of these I should use?  The study deals with the principles of a probabilistic decision support system which-that handles the problem of warning before users are trapped with the attackers’ first move.

Excuse me if this topic has been brought up before though I couldn't find it. It seems that there are many similar topics related to both defining and non-defining clauses but there is still one question that bothers me. I want to know about the difference between wh- pronouns (who, which, what...) vs. that in restrictive relative clause.   For example: The man that I saw at the mall looked puzzled.  The man who I saw at the mall looked puzzled.  I omitted commas intentionally, as I'm willing to talk about defining clauses only.   The Cambridge Grammar of the English Language gives quite vague description on that and I cannot think about actual examples:  "Relative clauses are so called because they are related by their form to an antecedent. They contain within their structure an anaphoric element whose interpretation is determined by the antecedent. This anaphoric element may be overt or covert. In the overt case the relative clause is marked by the presence of one of the relative words who, whom, whose, which, etc., as or within the initial constituent: clauses of this type we call wh relatives. In non-wh relatives the anaphoric element is covert, a gap; this class is then subdivided into that relatives and bare relatives depending on the presence or absence of that." Thanks in advance!   UPD: I know that it seems that in general there is no need to dig for this information but still I need this for my research.


My passport's cover's text is fading: the name of the country is still readable but the coat of arms has almost disappeared.  The rest of the passport is fairly okay--you can see I bring it around quite a lot, but it's not wet or broken and the personal information page is completely legible.  I have visa-free access to both Russia and China, so I wonder if they will be extra strict on me because of this. Noteworthy, I reside in Germany. Also, I will be entering by train to both countries.  Any (bad?) experiences?

My friend's passport is a bit worn out.  The passport is biometric and valid for five years(three left). The country's coat of arms, that should be on the cover is no longer visible. And the passport is a bit bent.  The first page with all the details about the person and all the pages inside are intact, no damage whatsoever.


Let $A$ be a complex $n×n$ matrix with $tr(A) = 0$. Show that there exists an invertible $n×n$ matrix $B$ such that all diagonal entries of $BAB^{-1}$ are zeros.  $\bf Edit:$ Is the fact that $\forall A\in M_{m\times n}(D)$, $D$ is $PID$, then $A$ is equivalent to a matrix which has the diagonal form $diag\{d_1,...,d_2,0,..,0\}$ where $d_i|d_j, i\leq j$and the other entries are zeros, applicable in this question?

Prove that if $A$ is a square matrix and $\mathrm{Tr}(A)=0$, then there exists an invertible matrix $R$ such that the matrix $T=R^{-1}AR$ has all entries on its main diagonal equal to $0$.   It seems like the formula $A=S\Lambda S^{-1}$, but maybe it does not help.  Thanks so much.


I would like to include another \partial sign, for example the one from mathpazo. i found a way to do it but i'm not sure wether it will change other things as well, so is this the right approach?  \documentclass{article} \DeclareSymbolFont{operator}{OML}{zplm}{m}{it} \DeclareMathSymbol{\p}{0}{operator}{"40}  \usepackage{commath}  \newcommand*{\pfrac}[2]{\dfrac{\p #1}{\p #2}} \begin{document} $\pfrac{^2 F}{x^2} =\dfrac{\partial^2 F}{\partial x^2}$ \end{document}   Best regards

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


There was a small  (150 pg paper back) book I read 20+ years ago in an college anthropology class.   I think the anthropology class was about race & ethnic relations and this book was some reading assignment I had.   The story line had something to do with some people going to moon and encountering different species of moon beings.    Each species was distinct and somewhat separate but never had conflicts with each other and even cooperated by using distinct abilities of each species.    I vaguely recall that the main human character(s) may have actually been a stow-away on the moon mission and there may have been a murder of either some of the moon beings or some of the human characters in book.   What is this book?

I know this is going to be a long shot but my father read a book around 1965-1967 about a space explorer who goes to a planet (he believes it is Mars) where he meets two warring alien tribes. One tribe is short and fat and one tribe is tall and skinny. He also remembers part of the story where the explorer believes one alien is urinating into the water supply and contaminating it but the alien is actually purifying it. Does this sound familiar to anyone? Thank you in advance.  ETA: He says this is not the novels with John Carter in them.


Given the simple linear regression y = Beta0 + Beta1x + e (epsilon) and e~N(0,sigma^2), to prove y is a multivariate normal I must show that it is a linear combination of multivariate normals correct?   So since I was given e~N(0,sigma^2), I let zi = ei/sigma and then e = sigma * I * zi. Therefore e = (e1, ..., en) is a MVN. Now do I simply set e = y - Beta0 + Beta1x and then state simply it must be a MVN since e is? I am lost at this help and any help or suggestion would be greatly appreciated! Thanks

I have a simple linear OLS regression $Y_i = \alpha+ \beta_1 X_{1i} + \beta_2 X_{2i} + e_i$ where $e_i \sim N(0,\sigma)$. I have estimated the regression from the data and obtained estimates for my coefficients as well as the corresponding covariance matrix. Assume my dataset is large (>500)  Now I would like to construct the 95% confidence interval for $Z = a_1 \beta_1 + a_2 \beta_2$. My first thought was that I could assume that Z follows a normal distribution because my regression coefficients are approximately normal and a linear combination of normal variables is also a normal variable. I do find some sources where they treat $Z$ as a normal random variable.  But now I am in doubt because I found that a linear combination of normal random variables is only normal if they are independent. So is it still save to assume $Z$ is random?


I know that it auto syncs between devices but I have 2 account and I'd like to export the custom search engines under chrome://settings/searchEngines and maybe import it in another account.  I know that this doesn't seem possible by default but maybe someone created a script or an extension to do it :)

I have created some search entries in Google Chrome using 'Edit search engines'.  How can I share some of these entries with my colleagues?


I'm teaching a class in which I want to demonstrate to my students that queries are not guaranteed to return results in a specific order without an explicit ORDER BY. I've observed that SQL Server seems to return ordered results even when ORDER BY is not present in the query. This is a problem because I'm concerned that my students will become confused on this point.  Examples of observed behaviour:   By default, data appears to be ordered in primary key order, even if the primary key is nonclustered. If I use GROUP BY, the result set appears to be in order of the last column. For example GROUP BY this, that ends up with the data in order of that, which is weird, especially if there is no index on it.   I haven't observed this behavior in other databases such as MySQL, PostgreSQL and SQLite. Is there something fundamentally different about SQL Server which causes it to order results for some queries even without an ORDER BY?   Now it seems to me that ordering the data when not asked is an extra unnecessary step which wastes processing time. Is that true?  And is there some kind of global setting that disables this behavior? Is there a way to get SQL Server to stop ordering data?  It also makes it harder to demonstrate to students that data is not automatically ordered.  Can anyone give me a simple demo script that shows the order of the results changing from execution to execution?

We all know that a simple statement such as:  SELECT * FROM stuff;   should not produce an ordered result. However, when I try to demonstrate this, it always comes out in primary key order.  Moreover a statement such as:  SELECT thing,whatever FROM stuff GROUP BY thing,whatever;   always appears to sort thing by the last field in the GROUP BY clause, which is not at all helpful.  The question is, under what circumstances does SQL SERVER order the result even if unasked, and what can I do to stop this?  I am trying to demonstrate to my students that order is indeterminate unless specified, but this is not helping my case.  I admit that I am working with a small set of sample data.  Thanks


I have tried in  but couldn't get exactly what I need.   Could somebody explain the difference between sudo su - & su -  Thank you.

I already read it from manual but I can't see difference..  su - change user ID or become superuser  sudo -s [command]   The -s (shell) option runs the shell specified by the SHELL environment variable if it is set or the shell as specified in passwd(5).  If a                    command is specified, it is passed to the shell for execution.  Otherwise, an interactive shell is executed.  sudo -i disappear description in manual


I intend to get into some serious study of Statistical Physics. I was hoping if you could tell me the best books in that field? I've heard Reif and Pathria are great. But for now, I can only afford one book. Any suggestions bw the two, or some other book idk of?

I learned thermodynamics and the basics of statistical mechanics but I'd like to sit through a good advanced book/books. Mainly I just want it to be thorough and to include all the math. And of course, it's always good to give as much intuition about the material.  Some things I'd be happy if it includes (but again, it mostly just needs to be a clear book even if it doesn't contain these) are:   As much justifications for the postulates if possible, I'm very interested in reading more about how Liouville's theorem connects to the postulates. Have examples of calculating partition functions, hopefully not just the partition function for the ideal gas.


I seem to be having a little issue with connecting to a remote server, to rsync my backups  what i have done so far  run    ssh-keygen created public and private key   run    ssh-copy-id -i my.key.pub 100.0.0.01  it all connected ok, i even went to remote server and checked     .ssh/authorized_key and confirmed the key was there  but when i run ssh 100.0.0.01 it still asks for a password, plus when i run a cron job to rsync it fails with permission denied.  Does anybody have any ideas as to why it wont connect?

I have Linux mint on my pc.   I have a public/private key pair to ssh into my router without having to type the password.  It works on Windows using putty, but Mint isn't when I run it from terminal.  ssh -i privkey.ppk root@10.12.1.1


Like the title says I'd like to do the memory test but there is no memory test in the GNU GRUB menu.

After having installed the 64bit version of Ubuntu 12.04 on my Lenovo B570 I ran into the same problems I had when installing 11.10 with Grub not playing nicely with a uEFI system. I used the same technique as last time to solve the problem (using a Super Grub Disc LiveCD session to repair Grub) and my system happily dual boots between Ubuntu and Windows 7  However now when I boot up the Grub menu only displays   Ubuntu, with Linux 3.2.0-24-generic Ubuntu, with Linux 3.2.0-24-generic (recovery mode) Previous Linux versions Windows 7 (loader) (on /dev/sda1) Windows Recovery Environment (loader) (on /dev/sda4)   I no longer see the option to use Memtest86+ which was there previously, having checked in the Ubuntu Software Center I can see that the package is installed, but how to I make the option to run it once again appear in the Grub menu?  I've tried:  sudo update-grub    which doesn't make any difference.  sudo chmod +x /etc/grub.d/20_memtest86+    results in:   chmod: cannot access /etc/grub.d/20_memtest86+': No such file or directory   and entering  ls /etc/grub.d/   results in:  00_header        10_linux      30_os-prober  41_custom 05_debian_theme  20_linux_xen  40_custom     README


I am a member of a level 7 gym. There are 2 Lapras, 2 Snorlax, 1 Arcanine, 1 Vaporeon, and 1 Pidgey. The current prestige of the gym is 25,432 / 30,000. The Arcanine joined and left the prestige at about 20,500. I trained (even though I'm already a member) to push the prestige to 25,432 so far. This sets a higher bar for someone who tries to conquer this gym, right? I'm not quite sure how it works.  Does this make sense? If I continue training and can push prestige above 30,000, then I've opened an extra defender slot, but I can't control who fills it. Someone walking down the street could notice this extra slot and join. I'd hope for a Dragonite, but I'll take any extra person to help defend.  So, does training a gym that I'm a member of help defend it?

How do gyms work in general? Do my Pokemon battle others there? How are the stats taken into consideration if they do battle?  If I leave my Pokemon in a gym that I will not be returning to, can I get the Pokemon back?


Does anyone know of a successful way to discover open UDP ports without using third party applications. So either by netstat or other method?

I have trouble identifying the application using port 25 on my Windows-10 system. Any useful hints to list used ports and using applications without 3rd party applications ?


I want to deploy a war file, to my tomcat manage, and the path is quite long, so I want to enter the path, but whenever I go into open file, I can only select the files manually, by going through the folder. Is there a way to enter the file path, I have attached a picture to show the UI I get  (BTW I'm using 16.04)

After running software updater, the path bar in the file dialog (for example the one you get when choosing Open File in in Google Chrome or Firefox) is missing. This is frustrating since it's no longer possible to copy a path from the terminal (for example) and paste it into the file dialog. Here is a screenshot of the dialog:     How can I get back the path bar?


Say you wanted a ship to have a bubble of atmosphere around it, 800m in diameter with the ship at the center. What sort of gravity (and perhaps magnetic field) would be needed? Would either of these make it impossible for habitation by living plants & animals?

If astronauts could deliver a large quantity of breathable air to somewhere with lower gravity, such as Earth's moon, would the air form an atmosphere, or would it float away and disappear? Is there a minimum amount of gravity necessary to trap a breathable atmosphere on a planet?


I've got an iPhone 5s with Camera + app. Even though it's aperture is fixed 2.2 I'm unable to take nice sharp portraits ( subject sharp and background blurred). I think this is due to the small sensor (?).  I wonder what would be the best option available to take photos like below? I don't mind to use an extra accessory.

I have wondered how to get some parts of the image out of focus when using smartphone cameras (or if it can even be done). Recently found out about the concept of bokeh, and am interested in techniques to use it in image composition for cell phone cameras (the typical 8MP low aperture size digicams prevalent in recent Android devices).


Call me odd, but I've come to enjoy the occasional encounters with female bards in certain bars around Skyrim.  Something about their songs just seems to add a bit of coziness to the environment.  I'm aware that you can be married in Skyrim (I already have an Amulet of Mara), but only to a certain sub-set of the single women in the world.  Are any of these eligible bachelorettes Bards?  If so:   Which ones?   If I marry one and ask her to move in with me, will she sing and play her songs in my house?

In the vein of  - Pete Hines, Bethesda's VP of PR and Marketing, when asked if Skyrim would support gay marriage :     You can marry anyone...Not any NPC, just mean any male or female.   So obviously some NPCs are off the list.  I assume I can't marry Jarl Balgruuf, but what about Irileth?  What about the Graybeards?  What about already-married NPCs?  Is it any "important" NPC, or is it more or less than that?  Has the Skyrim Creation Kit shed any light on how to determine this?


I have to prove that the series $\displaystyle\sum_{n=1}^\infty {\ln(n^2) \over n^2 }$ converges. The ratio test is inconclusive, so I should use the comparison test, but which series should I compare it with? I tried ${1\over n}$, ${1 \over n^2 }$, but I need a bigger series which converges to prove that this one converges.

I tried to demonstrate the convergence of the following series by root and ratio test but they failed.  $$\sum_{n=1}^{\infty}\frac{\log(n)}{n^2}$$  Then I used Wolfram Alpha, which answered "By the comparison test, the series converges".  How can I do it?


I have a question about existential instantiation. So, I am familiar with statements like "Let $x$ be an integer" or "Let $x$ $\in$ $\mathbb{Z}$". These statements define $x$ to represent a particular, but arbitrarily chosen integer. My question is, are we doing a similar thing when we do existential instantion? For example, lets start with the existential statement $P$ = "There exists an integer $x$ such that $x^2 = 4$". When we do existential instantiation on $P$, are we saying "Let $a$ be an element of the set of integers that make $P$ true?"

Before explaining my issue, I wanted to first explain what things do make sense to me. So, statements (used at the beginning of proofs) like "Suppose $x$ is an integer" or "Assume $x$ is an integer" make sense to me. The way I read them is like: "Let's just pretend that the symbol $x$ happens to represent an integer". Statement (also used in proofs) like "Let $x$ be 3" or "Let $x$ equal 3" also make sense to me. The way I read them is like: "Let's just temporarily name 3 with the symbol $x$. My issue comes with statements like "Let $x$ be an integer" or "Let $x$ $\in$ $\mathbb{Z}$". I really do not know how I should intuitively interpret such a statement. I can't interpret it in the same way as like "Let $x$ be 3" because there is not a specific object being assigned like 3. Should I interpret it like how I interpret "Suppose $x$ is an integer"?  EDIT: So, from what I gathered from the responses, I think I understand now how I should think of "Let $x$ be an integer". I could think of it as "Assume a newly created symbol x happens to represent an integer". However, this can cause issues as then "Let $x$ be an element of the empty set" is also completely valid. Instead, I should not think of "Let $x$ be an integer" as an assumption, but an assignment/declaration, just like "Let $x$ be 3". One tangible way to think about this is to imagine myself assigning the newly created symbol $x$ to an integer chosen in secret by a friend. With this mindset, $x$ is not assumed to be an integer - it is an integer. It is just unknown to me what integer it is. I hope this made sense to anybody with similar questions. If anyone thinks I have made an incorrect finding, please feel free to correct me.


The integral to be evaluated is  $$\int \frac {x^7-1}{\log x}dx$$  The actual question was to find the definite integral of the above in the limits $0$ to $1$. I could not apply any of the usual tricks to find that integral, hence I thought finding the indefinite integral first and then applying the limits would be the best way to evaluate the same.  I tried applying trigonometric substitution, which did'nt work. I also tried putting $x=e^t$, hoping to simplify the integral but that did not give me any results either.   How should I proceed to evaluate this integral?

/A problem from the 2012 MIT Integration Bee is $$ \int_0^1\frac{x^7-1}{\log(x)}\mathrm dx $$ The answer is $\log(8)$. Wolfram Alpha gives an indefinite form in terms of the logarithmic integral function, but times out doing the computation. Is there a way to do it by hand?


I have been wondering the real use of interface. please check the below code.  interface Animal {     public void eat();     public void travel(); }   public class MammalInt implements Animal{      public void eat(){         System.out.println("Mammal eats");     }      public void travel(){         System.out.println("Mammal travels");     }       public int noOfLegs(){         return 0;     }      public static void main(String args[]){         MammalInt m = new MammalInt();         m.eat();         m.travel();     } }    in the above code if i remove implements Animal from class declaration still the code works fine without any difference. So what is the actual use of interface. ?

I understand that they force you to implement methods and such but what I cant understand is why you would want to use them. Can anybody give me a good example or explanation on why I would want to implement this.


I am writing a text where the editor suggested to close all the definitions with a diamond.  So I was wondering, is there a easy way to automatically add a command to all the \end{definition} ? I looked the documentation of \theoremstyle, but it does not really seem to help.  Here is a working example where I did it manually...  \documentclass{article}  \usepackage{amssymb} \usepackage{amsthm} \theoremstyle{definition} \newtheorem{definition}{Definition}[section]  \newcommand{\xqed}[1]{%    \leavevmode\unskip\penalty9999 \hbox{}\nobreak\hfill    \quad\hbox{\ensuremath{#1}}} \newcommand{\Endofdef}{\xqed{\lozenge}}  \begin{document}  \begin{definition} (Stack Overflow) Stack Overflow is a privately held website, the flagship site of the Stack Exchange Network, created in 2008 by Jeff Atwood and Joel Spolsky, as a more open alternative to earlier Q\&A sites such as Experts Exchange.\Endofdef \end{definition}  \end{document}

What is the etiquette to denote the end of an example or remark? For proofs, it's the QED symbol (white box). I know it's not necessary for everyone, but I would like to use it to break up the text a little. What should I use? A circle or filled box or what?


I have received only one answer during the bounty period. The answer is good enough in the sense that I'll choose that path if that's really the last thing in the world I can do about it. Should I award the bounty to that guy?  (I'm still in the grace period. Should I wait or what)?

I asked a question and added a 50 point bounty (my first bounty question) but none of the answers actually provided anything solid and only tried to point me in the right direction with links I had already found myself.  I ended up solving the problem on my own and posted my code as an answer and accepted it.  I don't feel like either of the other answers showed significant knowledge or research and doubt they would be helpful for anyone in the future.  Since I can't award myself the points should I pick one of the other answers or just let them go into the void?  The question:


I am on read only on my microSD card, that previously I was able to read/write on. I've tried using different adapters, tried locking then unlocking those adapters (as well as putting the toggle in the middle), I've also tried reading the card on different computers, to no success. I've also tried to "overwrite" on the SDFormatter app (that I previously used when I was able to edit the card), but the SDFormatter also says that they cannot make changes unless the write protection is off. Any suggestions on how to fix this?

When I plug in my USB flash drive, it shows up on my computer as write-protected or read-only. I am unable to transfer data to it, nor can I modify or delete any files already stored on it. I also cannot repartition or reformat the drive using Windows Disk Management, DiskPart, GParted, or other tools. The drive does not have a write-protect switch.  Why did this happen and what can I do about it? Is there a way to remove the write protection?  (Note that this can happen with some memory cards, too, as they often use controllers similar to those used in flash drives. In some cases, the system may report that the drive or card was formatted successfully even though it was never actually formatted; the original data reappears when the device is reinserted.)     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this problem. Feel free to edit the answer to add additional details.


I believe I saw this done in a few plugins before, but it has been awhile and I have no clue what plugins offered this or how they offered it, but what I am trying to achieve is this...   I want offer a developer mode for my custom theme I'm creating.   I am running a function that if enabled will load the prettified files instead of the minified files for developers. But, I also want to load the prettified files if WP_DEBUG is enabled.   Is there a way I can check if a user has WP_DEBUG enabled?

I'm needing to debug one of my themes and I want to be able to switch on a debug mode so I can output more information or switch off debug mode and not see any information.   I noticed there is a debug variable defined in wp_config.php. I can easily set this to true or false. Is it OK to use this variable for my own debugging purposes or should I create my own?   Also, how do I check for if debug is true? My PHP is a bit rusty. Is this correct:   define('WP_DEBUG', true);  if ($WP_DEBUG) {    // do something }   My question is different.


I have 4 different web sites (A/B/C/D) and need to predict whether a user will rather convert on A/B/C or D or not convert at all. My data set has 100000 rows and only 100 of those are converted user (A/B/C), so very unbalanced. My explanatory variables are user session length, device type, refferal ect (most of them are factors). In case I had only one web site it would be quite easy, because I could have used logistic regression. Which statistical technique would you recommend for this type of question.

We already had multiple questions about unbalanced data when using , , ,  and a number of other similar questions, what makes it a very popular topic! Unfortunately, each of the questions seems to be algorithm-specific and I didn't find any general guidelines for dealing with unbalanced data.  Quoting , dealing with unbalanced data     (...) heavily depends on the learning method. Most general purpose   approaches have one (or several) ways to deal with this.   But when exactly should we worry about unbalanced data? Which algorithms are mostly affected by it and which are able to deal with it? Which algorithms would need us to balance the data? I am aware that discussing each of the algorithms would be impossible on Q&A site like this, I am rather looking for a general guidelines on when it could be a problem.


I want to split a List to several List according to some expression.   For example:  for elem in elemList:      if elem>0 and elem<=3   add element to Partition1      if elem>3 and elem<=6   add element to Partition2      else                    add element to Partition3   How to do it efficiently? Is there something like erase and push_back in list in C++ whose complexity is O(1)?  Or are there some other collections that can do it?

I haven't been able to find an understandable explanation of how to actually use Python's itertools.groupby() function.  What I'm trying to do is this:  Take a list - in this case, the children of an objectified lxml element Divide it into groups based on some criteria Then later iterate over each of these groups separately.  I've reviewed , but I've had trouble trying to apply them beyond a simple list of numbers. So, how do I use of itertools.groupby()?  Is there another technique I should be using?  Pointers to good "prerequisite" reading would also be appreciated.


the below integral is coming from M.Stein's complex analysis. chapter 3 exercise 9.  Show that $$\int_0^1\log(\sin \pi x)\text{d}x=-\log 2$$ use the contour shown in the above figure  Then I recall the definition of $\log(z)$,it must be defined on a simply connected domain $\Omega$ with $1\in \Omega$ and $0 \not\in \Omega$. In order to use the above contour to computer the integral. maybe consider $\int_{\gamma}\log(\sin \pi z)\text{dz}$,where $\gamma$ is the contour. but for $z=0$, there is no definition.   I think the author arrange the exercise here must expect the reader use residue formula to computer it. but I don't know how to. thanks very much

I need help with a textbook exercise (Stein's Complex Analysis, Chapter 3, Exercises 9). This exercise requires me to show that $$\int_0^1 \log(\sin \pi x)dx=-\log2$$ A hint is given as "Use the contour shown in Figure 9."    Since this is an exercise from Chapter 3, I think I should use the residue formula or something like that. But the function $f(x)=\log(\sin \pi x)$ becomes singular on $x=0$ and $x=1$, which makes the contour illegal for the residue theorem. Can anyone give me a further hint on this problem? Many thanks in advance!  P.S. This is my first time on Math Stack Exchange. If you find my post ambiguous, let me know.


When you want to leave a comment in the full site, initially there is the text:  enter at least 15 characters   However, in the mobile version of the site, it shows:  enter at least undefined characters  See an image:

When I open a new comment field, but before I have entered anything, next to the Add Comment button it says "enter at least undefined characters". When entering something then deleting all of it, the same message appears. This occurred on the page  but seems to happen regardless which page I use.  This is on Mozilla Firefox 68.0.2 on Android 9. No userscripts I'm aware of. By next to I mean that below the comment field, on the left hand side there is the Add Comment button, and in the middle (to the right of the button) there is the status message indicating either what I reported or (eg now) "267 characters left".  Screenshot:


I use a  and exile a  from my opponent's deck. I cast Kroxa, but then of course would have to sacrifice it because it wasn't escaped. Would it go back into my opponent's graveyard or mine? Am I able to escape it without the correct mana still?

If I were to cast  on one of my opponent's creatures then, while that creature is under my control for the turn, I cast  choosing to sacrifice the creature I took from him/her, does that creature go into my graveyard (since I control the permanent), or does it go into my opponent's graveyard?   This happened recently while playing with friends and we just decided to put it in the original owner's graveyard.


I have a simple question about static variables. If I declared a static variable in a function:  void main() {     int k = 0     while(k<=4)     {         fun();         k++;     } } int fun() {     static int i=5;     i++;     printf(Value %d\t", i);     return 0; }   As I know, the function will deallocate after returning. But where is the i value stored. Is a static variable like a global variable.

I've seen the word static used in different places in C code; is this like a static function/class in C# (where the implementation is shared across objects)?


I recently started learning Java and the first doubt I encountered is main is declared static in java so that JVM don't have to initialize the class for accessing main. But my question is why JVM avoid initializing the class which has main? What cost does it incur if we declare main as non-static?

The method signature of a Java main() method is:  public static void main(String[] args){     ... }   Is there a reason for this method to be static?


So i have a fresh new 1TB hdd and I don't want to install windows now because i don't have installation key. I want to install linux on a 200gb partition and leave rest as unallocated space for Windows installation Is there any harm keeping space unallocated Whenever I install windows, will i still be able to use GRUB or windows analogue of it? I want my pc to boot windows by default how do I do that?

I have Ubuntu on my laptop. Now I want install Windows 7 in a dual-boot. How can I do this? I can't lose my Ubuntu files, and I'm afraid that I might break . Go  for UEFI only!


I am an awards member with both American Airlines and British Airlines. I work in the Middle East and every month I'm either flying to the Middle East or flying home.   My company only has an account with BA and for the last 3 years after my flights are over I request miles to my AA account and have received them. So in fact I'm actually earning double miles. I don't know why but I have never requested miles for flights I fly with AA on my BA account.  This week I tried to add miles from my recent flights with AA to BA and they were rejected. When I called BA to find out why they had been rejected they told me they had already been credited to my AA rewards account and BA couldn't award me because that would be "double credit"...    I don't want to make too much of the issue if this will hurt me with my AA rewards. But is this correct? Any one else have this issue or could you help me ?

For example, I flew British Airways LAX-LHR. I wanted to get miles on Alaska Airlines so I sent in the boarding pass, etc and received credit.   I also have a mileage plan with American Airlines. Since British Airways is part of the Oneworld Alliance, can I also request to receive miles to my American AAdvantage account for this same flight? If so, will I lose the miles already credited to my Alaska account?  I'm not trying to be greedy.. just don't want to miss out on any miles.


Is there an svn command to check which files would be downloaded from the remote repository if one should issue an svn update?

I've committed changes in numerous files to a SVN repository from Eclipse.  I then go to website directory on the linux box where I want to update these changes from the repository to the directory there.  I want to say "svn update project100" which will update the directories under "project100" with all my added and changed files, etc.  HOWEVER, I don't want to necessarily update changes that I didn't make. So I thought I could say "svn status project100" but when I do this I get a totally different list of changes that will be made, none of mine are in the list, which is odd.  Hence to be sure that only my changes are updated to the web directory, I am forced to navigate to every directory where I know there is a change that I made and explicitly update only those files, e.g. "svn update newfile1.php" etc. which is tedious.  Can anyone shed any light on the standard working procedure here, namely how do I get an accurate list of all the changes that are about to be made before I execute the "svn update" command? I thought it was the "status" command.


I am currently working on a java project(design a card game) and there is a method to choose the suitable card in a player's hand. But A fatal error happend irregularly (not in a fixed time). Here is the header of the log *  # # A fatal error has been detected by the Java Runtime Environment: # #  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007fffd58ba714, pid=5604, tid=0x0000000000004314 # # JRE version: Java(TM) SE Runtime Environment (8.0_212-b10) (build 1.8.0_212-b10) # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.212-b10 mixed mode windows-amd64 compressed oops) # Problematic frame: # C  [zip.dll+0xa714] # # Failed to write core dump. Minidumps are not enabled by default on client versions of Windows # # If you would like to submit a bug report, please visit: #   http://bugreport.java.com/bugreport/crash.jsp # The crash happened outside the Java Virtual Machine in native code. # See problematic frame for where to report the bug. #   * It seems like the problem happends in native C (# C  [zip.dll+0xa714]).How can I fix it? BTW, I have tried deploy a larger memory to JVM. It still happends sometime.

When a Java VM crashes with an EXCEPTION_ACCESS_VIOLATION and produces an hs_err_pidXXX.log file, what does that indicate? The error itself is basically a null pointer exception. Is it always caused by a bug in the JVM, or are there other causes like malfunctioning hardware or software conflicts?  Edit: there is a native component, this is an SWT application on win32.


This is probably a duplicate but I m too dense to make this work. I m trying to learn capture groups etc but I cant make this one work, I get the right matches but only the last digit gets matched.      class Program    {      static void Main(string[] args)     {         string testTxt = "sadsadas168.asdsad";         string asdf = "wrongwrong";         string abc = "abc.png";         string bsdf = "100";         string lolol = "155abx.text";         string another = "sasd199.ong100";          TryMatch(testTxt);         TryMatch(asdf);         TryMatch(abc);         TryMatch(bsdf);         TryMatch(lolol);         TryMatch(another);          Console.ReadLine();      }      private static void TryMatch(string txt)     {         var rgx = new Regex(@"\w*(?<t>\d+)\w*\..*");         var m = rgx.Match(txt);          if (m.Success)         {             int mainID = int.Parse(m.Groups["t"].Value);             Console.WriteLine(m.Groups["t"].Value);         }         else         {             Console.WriteLine("Did not match " + txt);         }     } }

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


Just do not know how to write the average of a function. The symbol look like a integral sign with a short bar in the middle. It means integral of a function over a ball divide by the measure of the ball, and let the radius of the ball goes to 0+.

Is there in LaTeX a symbol or a macro for the average integral with a horizontal slash? I know about \strokedint, but I'd prefer the dash to be horizontal.


I have found some answers for this, but they were all outdated and didn't work. So I'm making a kind of battle royale type minigame in vanilla minecraft, and all I have left is seeing how many players are left. So I need to emit a redstone signal once only 1 player is in adventure mode. Currently, I am putting dead players in spectator mode.

I want to run a command when there are only 10 entities left. I know you can use /execute unless entity to detect when all matching mobs have died, but it doesn't work if you want to run a command when there are for example 10 entities left.  A command like /execute if entity @e[limit=10] does not work, it also triggers if there is only one entity.  Such a counting system could also be used to determine once there is only one player left in an arena, meaning they have won a battle or similar.


Everyone is familiar with the gold shirts of TOS and the red shirts of DS9/TNG, the ‘command track’ officers, but I’m somewhat confused about how their responsibilities contrast with ‘operations’, ‘engineering’, security, etc.  Were there roles that command track officers could occupy that other tracks could not? Obviously, all the main captains of the various shows have been in command colors, but is that coincidence, part of a captain’s uniform, or something else? Were there bridge positions that could not be occupied by a command track officer?

There are three division in Starfleet as evidenced by the three uniform colors:  Command Red (Gold in TOS era): Command decides what to do  Operations Gold (Red in TOS era):  includes security, operations and engineering.  In the greater sense Operations means accomplishing that which Command decides, so it includes scheduling, and keeping things safe, running, and working.  Science Blue: includes medical.   Science is science.  It means acquiring and using knowledge.  So (TNG-era) red for commanders, captains and admirals makes sense:  their job is to decide what the missions are and what the crew should do to accomplish the mission.  Helmsmen and "the conn" are generally manned by junior officers in red (TNG era).   This makes sense because they are carrying out orders and "commanding the ship".  But there are junior officers all over the place in red (TNG).  They are obviously not making decisions and giving orders all day long.   And there clearly don't need to be very many helmspeople on the ship.  What jobs do all these officers in red have?  (TNG era -- for TOS era, read as gold)    Everyone seems to be pointing out the things they have seen them do.   Helm, escorts, bridge relief.   Possibly, 'lesser management tasks'.   But none of these assertions explain how there can be so many of them.   It would require only a few officers out of a crew of a thousand -- maybe a hundred -- especially since we know that most management personnel in ops and science are wearing gold or blue uniforms.  If it was like people are saying, you would expect the sight of extras in red to be relatively rare.   If we have no in-universe explanation, okay -- that's an answer.


Unity brings up a window with shutdown/reboot options when pressed my pc power button. But how to do that with a command?

I want to create a shutdown icon for the launcher in 13.04. In former versions of Ubuntu I used this desktop file and put it in the launcher:  .local/share/applications/indicator-session-shutdown.desktop  [Desktop Entry] Name=Shut Down TryExec=/usr/lib/indicator-session/gtk-logout-helper Exec=/usr/lib/indicator-session/gtk-logout-helper --shutdown Icon=system-shutdown Terminal=false Type=Application OnlyShowIn=Unity; Categories=System; Version=1.0 X-Ubuntu-Gettext-Domain=indicator-session   I wonder if  /usr/lib/indicator-session/gtk-logout-helper --shutdown   is still the correct command in 13.04.  Here is a screenshot with old shutdown dialog:     Here is a screenshot with new shutdown dialog:


I am trying to make a glossary list and there is something weird going on: the spacing between entrances is uneven for no obvious reason. The minimal example of the code is below:  \documentclass{article}  \usepackage[nonumberlist,acronym]{glossaries-extra}  \setlength{\glsdescwidth}{6.5in}  \newglossarystyle{acronyms}{%acronymsandsymbols     \setglossarystyle{long}% based on the list style     \renewcommand*{\arraystretch}{1}     \renewcommand*{\glossarypreamble}{\vspace{4ex}     \glsresetentrycounter} % }  \makeglossaries  \newacronym{ASR}{ASR}{angular spectrum decomposition    (representation)} \newacronym{TAM}{TAM}{total angular momentum (TAM) vector} \newacronym{OAM}{OAM}{orbital angular momentum} \newacronym{SAM}{SAM}{spin angular momentum} \newacronym{QM}{QM}{quantum qechanics} \newacronym{QFT}{QFT}{quantum field theory} \newacronym{QED}{QED}{quantum electrodynamics}  \begin{document} \printglossary[style=acronyms,type=\acronymtype] \newpage  Hello here  \glsaddall  \end{document}   Output:   Thanks in advance!

I did the following glossary. However, when adding it in my document, the space between items isn't always the same (see pictures).  \documentclass[french]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{babel} \usepackage{graphicx} \usepackage{geometry} \usepackage{multirow} \usepackage{fancyhdr} \usepackage{drawstack} \usepackage{nameref} % For reference \usepackage{hyperref} % url reference \usepackage{tikz} % State diagram \usepackage{amsmath} % For matrix in state machine \usepackage{xcolor} \usepackage{wrapfig} \usepackage{amsthm} \usepackage[justification=centering]{caption} \usepackage{lastpage} % To add lastpage référence. \usepackage{siunitx} % For microsecond \usepackage[explicit]{titlesec} \usepackage{booktabs} \usepackage{tabularx} \usetikzlibrary{chains} \usepackage{epstopdf} \usepackage{lmodern} \usepackage{booktabs} \usepackage{etoolbox} \usepackage[most]{tcolorbox} \usepackage[toc, numberedsection,nonumberlist]{glossaries} \usepackage{chngcntr} % For table of figures section number  \makeglossaries  \begin{document}  \newglossaryentry{RIP}{ name=RIP, description={Routing Information Protocol, un protocol de routage dynamique} } \newglossaryentry{OSPF}{ name=OSPF, description={Open Shortless Path Finder} } \newglossaryentry{Hop}{ name=Hop, description={De l'anglais, saut. Décrit le nombre de passage au travers d'un routeur} } \newglossaryentry{vlsm}{ name=VLSM, description={Variable Length Subnet Mask, sous réseau de taille variable} } \newglossaryentry{RFC}{ name=RFC, description={Request for Comment, série de documents établis par l'IETF et l'ISOC   décrivant les aspects techniques d'Internet ou de différents matériels informatiques} } \newglossaryentry{IETF}{ name=IETF, description={Internet Enginnering Task Force, organisation développant des   standards pour Internet} } \newglossaryentry{ISOC}{ name=ISOC, description={Internet Society, organisation pour promouvoir et coordonner le   développement des réseaux} }  \newglossaryentry{sa}{ name=SA, description={Système autonome (Autonomous System). Ce dit d'un réseau avec   une administration commune, comme le réseau Switch} } \newglossaryentry{IGP}{ name=IGP, description={Interior Gateway Protocol, type de protocole utilisé dans un   système autonome} } \newglossaryentry{EGP}{ name=EGP, description={Exterior Gateway Protocol, type de protocole utilisé entre des   réseaux autonomes} } \newglossaryentry{NDP}{ name=NDP, description={Neighbor Discovery Protocol} } \newglossaryentry{ARB}{ name=ARB, description={Area Border Router, routeur reliant deux zones différentes dans un système autonome utlisant OSPF comme protocole de routage dynamique.} } \newglossaryentry{ASBR}{ name=ASBR, description={AS Boundery Router, routeur échangeant des informations avec   des sources en dehors du système autonome.} } \glsaddall \printglossaries  \end{document}


Supposing I wanted to send a one-time pad to a friend. What would be a good way to do that, supposing that it could be intercepted? At first blush, encrypting it would seem safe, because the encryption would seem impossible to crack, given that what it encodes is random (result of unsuccessful decryption is not obviously indistinguishable from successful deception). Yet perhaps there is still a risk is if the encrypted one time pad and a message encoded with it were intercepted.

It seems that OTP encryption is unbreakable. I have read some articles (Wikipedia, Blogpost, etc.), but I could not find any information about how they are used.  If I wanted to create a messenger service, how would I distribute the OTP keys? Both the sender and the receiver need this key before the message is sent, right?   And how do I make sure no one else gets these keys?


I have set up 2 ubuntu instances in aws. How do I sync /usr/ubuntu in both the machines?

I would like to transfer files between two remote hosts using on local shell, but it seems rsync doesn't support synchronisation if two remotes are specified as follow:  $ rsync -vuar host1:/var/www host2:/var/www The source and destination cannot both be remote.   What other workarounds/commands I could use to achieve similar results?


I was reading the  and in this paragraph,      We could consider whitening activations at every training step or at   some interval, either by modifying the network directly or by changing   the parameters of the optimization algorithm to depend on the network   activation values (Wiesler et al., 2014; Raiko et al., 2012; Povey et   al., 2014; Desjardins & Kavukcuoglu). However, if these modifications   are interspersed with the optimization steps, then the gradient   descent step may attempt to update the parameters in a way that   requires the normalization to be updated, which reduces the effect of   the gradient step. For example, consider a layer with the input $u$ that   adds the learned bias $b$, and normalizes the result by subtracting the   mean of the activation computed over the training data: $\hat{x} = x − E[x]$   where $x = u + b$, $\mathcal{X} = \{x_{1 \ldots N} \}$ is the set of values of $x$ over he   training set, and $E[x] = \frac{1}{N} \sum_{i=1}^N x_i$ . If a gradient descent step   ignores the dependence of $E[x]$ on $b$, then it will update $b \leftarrow b + \Delta b$,   where $\Delta b \propto −\partial l/ \partial \hat{x}$. Then $u + (b + \Delta b) − E[u + (b + \Delta b)] = u + b − E[u + b]$. Thus, the combination of the update to $b$ and subsequent change in normalization led to no change in the output of the layer nor,   consequently, the loss. As the training continues, $b$ will grow   indefinitely while the loss remains fixed. This problem can get worse   if the normalization not only centers but also scales the activations.   We have observed this empirically in initial experiments, where the   model blows up when the normalization parameters are computed outside   the gradient descent step.   What's the point of having $b$ anyway? (Later in the paper, it says that b is removed during batch normalization, so what's the aim of the math shown in this picture and how is this* math different from the one that we do during actual batch normalization).  This happens later in the paper,     Note that, since we normalize Wu+b, the bias b can be ignored since   its effect will be canceled by the subsequent mean subtraction (the   role of the bias is subsumed by β in Alg. 1). Thus, z = g(Wu + b) is   replaced with z = g(BN(Wu))

In the paper Batch Normalization: Accelerating Deep Network Training b y Reducing Internal Covariate Shift () Before explaining the process of batch normalization the paper tries to explain the issues related with (I am not getting what the exact issue addressed here is).  excerpt from section 2, para 2:     We could consider whitening activations at every training   step or at some interval, either by modifying the   network directly or by changing the parameters of the   optimization algorithm to depend on the network activation   values (Wiesler et al., 2014; Raiko et al., 2012;   Povey et al., 2014; Desjardins & Kavukcuoglu). However,   if these modifications are interspersed with the optimization   steps, then the gradient descent step may attempt   to update the parameters in a way that requires   the normalization to be updated, which reduces the effect   of the gradient step. For example, consider a layer   with the input u that adds the learned bias $b$, and normalizes   the result by subtracting the mean of the activation   computed over the training data: $\hat x= x − E[x]$ where   $x = u + b, X = {x_{1...N}}$ is the set of values of $x$ over   the training set, and $E[x] = \frac 1 N(\sum_{i=1}^nx_i)$   .       If a gradient   descent step ignores the dependence of E[x] on b, then it   will update $b ← b + ∆b$, where $∆b ∝ −\partial l/\partial\hat x$. Then   $$u + (b + ∆b) − E[u + (b + ∆b)] = u + b − E[u + b] \tag 1$$.      Thus, the combination of the update to b and subsequent   change in normalization led to no change in the output   of the layer nor, consequently, the loss. As the training   continues, b will grow indefinitely while the loss remains   fixed. This problem can get worse if the normalization not   only centers but also scales the activations.   here is my understanding of the literature:   We have a batch of size N (One training batch) Let there be two arbitrary hidden layer connected to each other (L1 and L2) connected by parameters $W$ and $b$ output coming out of L1 is x1  $u = x1W$ (this is where the literature above starts. dimension of u is MxN)(M is the number of units in L2) $x = u+b$ (dimension b = dimension x = dimension u = MxN) Now before feeding x into L2 we centre it by subtracting the mean of $x$ from each entry in $x$ ($\hat x= x − E[x]$) We compute the loss and backpropogate the gradient and update just this layer's $b$ in order to give it a sanity test. New $b$ = $b + \Delta b$ We run it again on the same batch with updated $b$ repeat 3 and 4 $x_{new} = u+b + \Delta b$ (dimension b, $\Delta b$ = dimension x = dimension u = MxN) Now before feeding x into L2 we centre it by subtracting the mean of $x$ from each entry in $x$ ($\hat x = x + \Delta b − E[x + \Delta b] = x - E[x]$). which is the same as what was calculated before updating b and hence updating b had to effect on the training   My question is with this part of the excerpt:  "If a gradient descent step ignores the dependence of E[x] on b, then it will update $b ← b + ∆b$, where $∆b ∝ −\partial l/\partial\hat x$. Then $$u + (b + ∆b) − E[u + (b + ∆b)] = u + b − E[u + b] \tag 1$$."  Why is   " $$u + (b + ∆b) − E[u + (b + ∆b)] = u + b − E[u + b] \tag 1$$." dependent upon what comes before it? What is even the point of that bit? Please also note the useage of word "Then" (made bold) implying the statement necessarily draws causality from what comes before


Assume we have a calculator with the following flaw. The only operations can be done by it are $+$ and $-$ and $\dfrac{1}{x}$ i.e. you only can add or subtract two numbers and also calculate the reciprocal but you can't multiply or divide. Using this calculator how can you multiply two numbers?   I twiddled with lots of formulas but I got nowhere. Sorry if  I can't add any further information or idea. I appreciate any solution on this....

Can the product of $A, B$ be computed using only $+, -,$ and reciprocal operators using a calculator? You can use calculator's memory function (multiply and divide are broken though).  Additional: I should have mentioned earlier, in addition to the 3 operators, the numberpad of the calculator can be used so yes 1 can be used.


I have to serialize around a million items and I get the following exception when I run my code:  Exception in thread "main" java.lang.OutOfMemoryError: Java heap space     at java.util.Arrays.copyOfRange(Unknown Source)     at java.lang.String.<init>(Unknown Source)     at java.io.BufferedReader.readLine(Unknown Source)     at java.io.BufferedReader.readLine(Unknown Source)     at org.girs.TopicParser.dump(TopicParser.java:23)     at org.girs.TopicParser.main(TopicParser.java:59)   How do I handle this?

I am writing a client-side Swing application (graphical font designer) on Java 5. Recently, I am running into java.lang.OutOfMemoryError: Java heap space error because I am not being conservative on memory usage. The user can open unlimited number of files, and the program keeps the opened objects in the memory. After a quick research I found  and others saying on Windows machine the JVM defaults max heap size as 64MB.  Given this situation, how should I deal with this constraint?  I could increase the max heap size using command line option to java, but that would require figuring out available RAM and writing some launching program or script. Besides, increasing to some finite max does not ultimately get rid of the issue.  I could rewrite some of my code to persist objects to file system frequently (using database is the same thing) to free up the memory. It could work, but it's probably a lot work too.  If you could point me to details of above ideas or some alternatives like automatic virtual memory, extending heap size dynamically, that will be great.


We are out to setup a Windows 2012r2 server with Exchange 2013. It is just to be a simple single domain at one site with about 25 users. So my boss want something that is fault tolerant, if the hardware or software fails we can come up within a day. My boss is talking of buying two Server boxes just to have hardware redundancy in the coming years,  but I am unsure because I do not think we also want to buy addition server licenses?  Would we need to buy 2 copies of the software? So the question is what kind of simple server setup do you advise for this?

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


In Dungeons and Dragons if a monster attacks and hits what happens with this damage: 4(1d4+2)? Do you add inside the parenthesis then multiply by 4?

My friends and I are very new to D&D, played like 3 times. In a monster's stats next to weapon damage it says stuff like "+11 to hit" and "Hit: 5 (1d8+1)". For the premade characters it just says things like "+4, 2d6 + 2 slashing", though. Why are there two "hit" numbers for monsters? Which do I use for the d20 roll to hit against a target's AC?  I mean for example like in the Ogre entry in the "" article on monsters.


I am making program where user can choose image with FileChooser and display it in program. But i want to save all the images in my folder. I want to store all the images there. So is there any option if user choose image which is on desktop to make a copy of that image and paste it in my folder?

It has always bothered me that the only way to copy a file in Java involves opening streams, declaring a buffer, reading in one file, looping through it, and writing it out to the other steam.  The web is littered with similar, yet still slightly different implementations of this type of solution.  Is there a better way that stays within the bounds of the Java language (meaning does not involve exec-ing OS specific commands)?  Perhaps in some reliable open source utility package, that would at least obscure this underlying implementation and provide a one line solution?


I have two array list, the first  called que and the second list shuffledQue which is a shuffled que.I have an integer indicating to the current position of the item in the que called currentTrackIndex, so when I assign the que to shuffledQue and shuffle the list I look for the new position of the current item and assign it to currentShuffledTrackIndex. But what I get afterwards is that que changes the position of it's items.                      List<TrackModel> que = new ArrayList<>();                     List <TrackModel> shuffledQue = new ArrayList<>();                     /*                      some code where I add items to the que                      */                         boolean shuffle = intent.getBooleanExtra("isOn", true);                         TrackModel currentTrack3 = que.get(currentTrackIndex);                         if(shuffle) {                             for(int i =0; i < que.size(); i++){                                 TrackModel model = que.get(i);                                 String trackname = model.getaName();                                 Log.i("TAG", "que " + trackname);                             }                             shuffledQue = que;                             Collections.shuffle(shuffledQue);                             for(int i = 0; i < shuffledQue.size(); i++)                             {                                 TrackModel trackModel = shuffledQue.get(i);                                 if(trackModel.getID() == currentTrack3.getID()){                                     currentShuffledTrackIndex = shuffledQue.indexOf(trackModel);                                 }                             }                              for(int i =0; i < que.size(); i++){                                 TrackModel model = que.get(i);                                 String trackname = model.getaName();                                 Log.i("TAG", "que2 " + trackname);                             }                             preferences.edit().putInt("selected_track", currentShuffledTrackIndex).apply();                             json = gson.toJson(shuffledQue);                             preferences.edit().putString("shuffledQueJSON", json).apply();                         }   logcat     12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que Frank Sinatra Fly Me To The Moon 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que Marshmello - Alone (Official Music Video) 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que [Electro] - Laszlo - Supernova [Monstercat Release 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que Louis Armstrong - What A Wonderful World [HQ] 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que Chris Brown - Turn Up the Music 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que Vangelis - Alpha 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que2 Louis Armstrong - What A Wonderful World [HQ] 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que2 [Electro] - Laszlo - Supernova [Monstercat Release 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que2 Vangelis - Alpha 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que2 Chris Brown - Turn Up the Music 12-19 21:11:34.277 14704-14704/com.sparidapps.musicplayer I/TAG: que2 Frank Sinatra Fly Me To The Moon 12-19 21:11:34.278 14704-14704/com.sparidapps.musicplayer I/TAG: que2 Marshmello - Alone (Official Music Video)   As you see in the logcat the items of the que list change their position, and I couldn't figure out why. Thanks in advance!

How can I clone an ArrayList and also clone its items in Java?  For example I have:  ArrayList<Dog> dogs = getDogs(); ArrayList<Dog> clonedList = ....something to do with dogs....   And I would expect that objects in clonedList are not the same as in dogs list.


What ever I go to the material viewer my texture doesn't show but instead shows grey out texture. Also what ever I move the view the grey texture just moves outside the model. Are there some ways I could fix that?

I don't know why but now, when i go in material preview or rendered (in solid mode it works fine), my object is entirely gray, or invisible idk, because it has the same color of the background. I've been working for days on this project without having this issue, it suddenly showed up. I tried opening other old projects and suddenly they all do the same so i guess it is some blender program setting that applies for all the projects, but idk how it happened cuz i didn't change anything :/, anyone got any tips?


I would like to reproduce the file as shows the picture attached to this message, specially the part circled in red color. Thank you in advanced.  This is the minimal working example code:  \documentclass{beamer} %slides \usepackage[utf8]{inputenc} \usepackage[french]{babel} \usepackage {textcomp} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{url} \usepackage{graphicx} \usepackage{xcolor} \usepackage{topcapt} \usepackage{setspace} \usepackage{bbding} %Checkmark \usepackage{lmodern} \usepackage{subfig}  \usetheme{Warsaw} \useinnertheme[shadow=true]{rounded}  \setbeamercovered{transparent}  \date{\today}  \title[Titre]{Titre} \institute{Université}  \author[author1]{Student\inst{1}\\[1ex]  {\small supervisor1\inst{1} supervisor2\inst{2}}}  %%%%%%%%%%%%%%Insertion numéros de page et courte version du titre \expandafter\def\expandafter\insertshorttitle\expandafter{%   \insertshorttitle\hfill%   \insertframenumber\,/\,\inserttotalframenumber}  \begin{document}      \maketitle  \end{document}

I want to make a cover page as the attached figure. The problem is that the beamer has, by default, the macros predefined: \author{} \title{} ', ... and their location is fixed by default. Could you help me?  Here is my code:  \title[Short Paper Title]   {presentation}  \subtitle {About some things}  \author   { Author}   \institute  { Department of Computer Science\\ University of Somewhere }  \date  {\today}


Can I say something like, ∀ x,y ∈ B, x + (-y) ∈ B ⇒ x - y ∈ B by definition of subtraction?? I'm lost

Let $G$ be a group. Show that a nonempty subset $H$ is a subgroup of $G$ if any only if $ab^{-1} \in H $ for any $a,b \in H$.  The forward direction is quite easy. Suppose $H$ is a subgroup. Then by closure, $ab \in H$ for any $a,b \in H$. Every element has an inverse. Hence, if $b \in H $, then $b^{-1} \in H$. Hence, by closure again, $ab^{-1} \in H$.   Backward direction, suppose $ab^{-1} \in H $ for any $a,b \in H$. Let $a=b$. Then we have $bb^{-1}=1_H\in H$. Let $a=1_H$ , we have $1_Hb^{-1}=b^{-1} \in H$. I don't know how to show closure.  Reference: Fraleigh p. 58  Question 5.45 in A First Course in Abstract Algebra


This might seems off topic or something, but I am a middle school student and i'm really into Quantum Field Theory and String theory and every video on youtube or article on the internet shows only the concept and Intro to these theories but I want to know about the maths envolved and do the maths myself as well , so i would love it if you guys would be suggest me a site or anything else where i can learn from scratch all the maths involved in Quantum Mechanics and maybe Einstein's Relativity as well.

What are the best textbooks to read for the mathematical background you need for modern physics, such as, string theory?  Some subjects off the top of my head that probably need covering:   Differential geometry, Manifolds, etc. Lie groups, Lie algebras and their representation theory. Algebraic topology.


Not sure if this was brought before but I noticed on several occasions that code containing HEREDOC syntax will not be correctly highlighted. Example at

I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange?


I am executing below code after overriding hashcode method of an object (BookMe). Aim is to override hashcode of the object which i will be using as a key in my map (hashmap). But, after executing I see null values. The is no problem with the actual size of map. below is the code. If I don't override hashcode method I get correct output (i mean all three values).  `  class BookMe{ private String isbn ; static int i = 0; public BookMe(String isbn) {    this.isbn = isbn;      } public String getIsbnValue() {     return this.isbn; } @Override public boolean equals(Object o) {     if(o instanceof BookMe && ((BookMe)o).getIsbnValue() == this.getIsbnValue())     {         return true;     }     else{         return false;     } } @Override public int hashCode() {     return this.isbn.toString().length() + (++i); }   }  public class HashMapTest {  public static void main(String[] args) {      Map<BookMe, Integer> map = new HashMap<BookMe, Integer>();      BookMe b1 = new BookMe("Graham");     BookMe b2 = new BookMe("Graham");     BookMe b3 = new BookMe("Graham");     map.put(b1, 19);     map.put(b2, 33);     map.put(b3, 22);      System.out.println("----444444--------");     System.out.println(map.size());      Set <BookMe> set = map.keySet();     System.out.println("------*****------");       for(BookMe bk : set)     {         System.out.println("bk : "+ bk);         System.out.println(map.get(bk));     }        }   } `

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I am trying to generate divs with Javascript dynamically. What I mean: in the first div there will be a button with a .click event and when it will be clicked I want a new div to be generated. Inside the new div there must be another button with a .click event which will act as the first one. My problem is that in the div that is generated that button does not create a new div. This is my js function: $(function() {         $('#openFirstTab').click(function(){             var newDiv = $('

A modern responsive front-end framework based on Material Design
<button id="openSecondTab">Add Div</button>
');           $('.row').append(newDiv);         });         $('#openSecondTab').click(function(){             var newDiv = $('

A modern responsive front-end framework based on Material Design
<button id="openSecondTab">Add Div</button>
');           $('.row').append(newDiv);         });     });  and the HTML:

Starter Template

A modern responsive front-end               framework based on Material Design
         <button id="openFirstTab">Add Div</button>

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.


So I was reading a book, and came across a statement that out of objects like $1$ kg of steel, $1$ kg of water and $1$ kg of feathers, a hydrogen balloon would find it easier to lift up with the feathers. I am guessing it is due to the fact that feathers are the least dense of the given substances. Am I right in thinking so. I mainly got this doubt, because the masses of all three substances are same, and so, it would require same force.

if i have a block of cotton and a block of iron each containing a weight of 100 kg when measured on a weighing machine, in reality which one is heaver than the other, which one is heavier and why?  This question was in my physics worksheet. The teacher gave the following answer: the apparent weight of both of them is the same, but the buoyant force of cotton is high since the volume of cotton is more than iron. Therefore, true weight of cotton is more. Does this answer make sense? What is the right answer?


static void sort(int array[]) {     //int array[]={20,40,30,60,70,80,50,90};     if(array.length==1)         return;      int mid=array.length / 2;     int part1[]=new int[mid];     int part2[]=new int[array.length-mid];      for(int i=0; i<array.length; i++)     {         if(i<mid)         {             part1[i]=array[i];         }         else         {             part2[i-mid]=array[i];         }     }      sort(part1);     sort(part2);      merge(part1,part2,array);     //for(int x=0; x<part1.length; x++)         //System.out.print(part1[x]+" ");      //for(int x=0; x<part2.length; x++)         //System.out.print(part2[x]+" ");  }   i know recursion is method(function) that call it self. im confused in this code why that program stop, when the sort() method execute and call itself sort(part1)method then the sort(part1) is executed again and again and how sort(part2) and merge(part1,part2,array) is executed, why this code is not infinite and how the program stop.  sorry im new in java

One of the topics that seems to come up regularly on mailing lists and online discussions is the merits (or lack thereof) of doing a Computer Science Degree. An argument that seems to come up time and again for the negative party is that they have been coding for some number of years and they have never used recursion.  So the question is:   What is recursion? When would I use recursion? Why don't people use recursion?


I currently have a question with (what I feel is) a very large bounty.  While the question has received some excellent attention, there is only one answer of (in my opinion) somewhat low quality.  As the only answer, I believe it will receive the bounty when it auto-awards.  I feel as though the answer was only posted in order to obtain the bounty auto-award by default.  I have no problem forfeiting the reputation from the bounty, but I'd prefer it to go on an answer of semi-quality, and not have it auto-award to what amounts to an answer for the sake of answering.  I feel that this "bounty sniping" constitutes an actual problem with the system's (ostensibly fake and worthless) currency.  Is there a way to circumvent the auto-award and just have the bounty get discarded?

I recently put a bounty on a question regarding the . I did this as the only two answers on that page are not satisfactory and I wish to encourage a tractable answer.  I am concerned that when the bounty period expires, if I do not select an answer for the bounty that it may be awarded automatically to one of these speculative and unsatisfactory answers. How might I prevent that? I could put an answer of my own stating "no satisfactory sources are available" and award the bounty to that, however I feel that there should be a better way.  I stress that I put the bounty on the question specifically because the current answers are not satisfactory and I do not want to award them.


Suppose we want to do simple linear regression. Before we do simple linear regression, we need to check these following assumptions (please correct me if I'm wrong):   Linear relationship Normality of residual Homoskedasticity of residual No autocorrelation   My question is: When the data doesn't follow several or even all of the assumption, which one should be handled first?  I have several data that have one variable independent (X) and one variable dependent (Y).   My first data violates normality and autocorrelation assumption. When I handled the autocorrelation using Cochrane-Orcutt transformation, the data became normally distributed. In this case, did I only need to handle the autocorrelation issue? My second data violates autocorrelation assumption. I handled it with the same method, but the data became non-normally distributed. What should I do? My third data doesn't follow linearity and normality assumption. I tried to handle the normality issue first by transforming the orginal data to sqrt(X) and sqrt(Y) (I'm not sure this is right to do), then did linearity test again, and the result said that the data was linear. My fourth data violates normality, heteroskedasticity, and autocorrelation assumption. Since transformation method will affect result of the other assumption test, which issue should be handled first to get right conclusion?

In linear regression analysis, we analyze outliers, investigate multicollinearity, test heteroscedasticty.   The question is:  Is there any order to apply these? I mean, do we have to analyze outliers very firstly, and then examine multicollinearity? Or reverse?    Is there any rule of thumb about this?


When I try to lunch my virtual machine, it gives me this error: The VirtualBox Linux kernel driver is either not loaded or not set up correctly. Please reinstall virtualbox-dkms package and load the kernel module by executing  'modprobe vboxdrv'  as root.  If your system has EFI Secure Boot enabled you may also need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system's documentation for more information.  where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.   When I write modprobe vboxdrv, it gives me this output: modprobe: ERROR: could not insert 'vboxdrv': Operation not permitted  Any suggestions?  when I search for vboxdrv I can't find it on my computer, but also udo vboxconfig seems not to be in sbin folder.  There is also another message about the kernel problem, that is this one: Failed to start LSB: VirtualBox Linux kernel module.

I upgrade from Ubuntu 15.10 to 16.04 and since then VirtualBox 5.0.18 isn't starting my VMs anymore. It complains that 'vboxdrv' isn't loaded. So I try to load it and get the following error:  $ sudo modprobe vboxdrv modprobe: ERROR: could not insert 'vboxdrv': Required key not available   I believe it is related to secure boot which I use and which I want to continue using. Actually with Ubuntu 15.10 secure boot and VirtualBox were working just fine.  Also I tried $ sudo apt-get --reinstall install virtualbox-dkms which built the kernel module successfully but didn't solve this issue.  Any idea how to get vboxdrv loaded while keeping secure boot enabled?  Update 2: Also I tried executing sudo mokutil --disable-validation. When executing this command, during the next boot I get prompted to disable secure boot, add a key or hash from disk. Since I don't want to disable secure boot, it seems that this doesn't solve my issue either. Also I want to keep UEFI activated for a parallel Windows installation.  Note: If you don't mind disabling secure boot, see  instead.


I can't see this as an option so is there a way to select faces or islands and have them show up as selected faces on the object in 3D view.  In programs such as maya it is possible to work from either view and makes selection and mapping a little more user friendly.  I suspect it isn't possible in Blender but welcome your feed back.  Edited as flag as already answered, although the question was not asked in the other post in a way that showed in my search.  I was looking for face and island selection to show in both views. The other asked about unselected vertices this obviously did not appear in the results.

Is there a way to show all vertices (even if they're unselected in the 3D view) in the UV editor?


I have two VM machines (with exact hardware-software configuration on two ESXI Servers in same rack and same subnet too) that is running with nginx + PHP-FPM + and MariaDB 10.4. in each ESXI server I have just 1 VM with 24G RAM, 24 Core CPU On standalone nodes the TPS is 8000 avg. But when I switched to galera Master-Master replication mode with below conf, The TPS is decrease into 1100 avg! each server's app using It's local DB. here is my.cnf  [mysqld] skip-name-resolve binlog_format=ROW wsrep_on=ON wsrep_replicate_myisam=ON wsrep_provider=/usr/lib64/galera-4/libgalera_smm.so wsrep_cluster_address="gcomm://192.168.7.11,192.168.7.12" wsrep_cluster_name="my_cluster" wsrep_node_address="192.168.7.11" wsrep_node_name="node1" wsrep_sst_method=rsync wsrep_slave_threads=16 innodb_flush_log_at_trx_commit=2 innodb_flush_method = O_DIRECT   What am I missing?

I am running an application which inserts a lot of rows and we were experiencing some low performance. So i started benchmarking the Galera Cluster with sysbench and oltp_insert.lua (practically inserts with random key).  The performance of the cluster is really bad.   With the same test:    As a standalone DB i can perform about 35000 tps  With Galera multi-master the performance is: 350 tps   The table structure is this one:         Table: sbtest1 Create Table: CREATE TABLE `sbtest1` (   `id` int(11) NOT NULL,   `k` int(11) NOT NULL DEFAULT '0',   `c` char(120) NOT NULL DEFAULT '',   `pad` char(60) NOT NULL DEFAULT '',   PRIMARY KEY (`id`),   KEY `k_1` (`k`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1   What i tried so far (with no success):   increase wsrep_slave_threads=16 no matter how many client threads i use, the TPS is still 350 (looks like the transactions are serialized somehow by the DB) set wsrep_sync_wait=0 (although i perform no reads) the db does not use binlog, its not enabled.   Configuration:  [mysqld]    binlog_format=ROW    innodb_autoinc_lock_mode=2     bind-address=0.0.0.0    datadir=/var/lib/mysql  innodb_buffer_pool_size = 300MB innodb_large_prefix=1 innodb_file_format=Barracuda  transaction-isolation = READ-COMMITTED  wsrep_on=ON   wsrep_provider=/usr/lib64/galera/libgalera_smm.so            wsrep_slave_threads = 16          wsrep_max_ws_rows=131072     wsrep_max_ws_size=1073741824     wsrep_convert_LOCK_to_trx=0     wsrep_causal_reads=OFF wsrep_sst_method=xtrabackup-v2


Consider:  int a = Convert.ToChar(textBox3.Text);   The textbox contains a string of elements like abcd. From the above syntax I am not able to convert the entire string of elements and the error is like string must be exactly one character long. Whereas if the textbox is having only one element it is working fine.

I want to get the ASCII value of characters in a string in C#.  If my string has the value "9quali52ty3", I want an array with the ASCII values of each of the 11 characters.  How can I get ASCII values in C#?


Given $A$ is a subset of grouo $G$ and $|A|>|\frac{G}{2}|$. How do i prove that each element  of $G$ is product of rwo elements of $A$? I don't know where to begin, a hint would be very helpful.

I'v found this proposition.  If $G$ is a finite  group , $ A \subset G $ a subset and $|A| > \frac{|G|}{2} $ then $AA = G $.  Why this is true ?


Could dark matter or dark energy be explained by a massive amount of 'mass' creating far reaching gravity far beyond our galaxy? Pulling things away from us at an accelerated rate?  Or maybe a 'sucking' effect of nothingness pulling space/mass?

This may be a silly question, but is it possible that dark energy and gravity are related to each other?   Space-time is deformed everywhere in space by objects with mass. The more massive the object, the more deformation in the local area, and, as a result, the more concentrated space-time is within that deformation. However, where is the "extra" space-time coming from to be able to form these super-concentrated regions of space-time? Is that what we observe as dark energy?  Is it possible that at great enough distances, gravity could be pulling space-time apart due to the lack of mass in the great voids of space? Not only that, but if there was enough mass in a part of space to have a little more gravity than the surrounding area, it could prevent that area of space from being "stretched out." Thus, might dark matter just be regions of space where space-time is denser than the surrounding regions?  I'm sure these aren't new ideas, but I'd like to know what premises and assumptions are incorrect.


I have a hard time verbalizing how shocked and horrified I am to learn that questions can be and actually are deleted.  The only reasonable use case I see is spam or very clear abuse.  But anything else should not be put to death. At the age of 6, in my first school year, I learned: "Every question has value." "There are no bad questions."  I still consider this true to this day.  Deleting questions is so senseless. Why delete information? What seems unimportant to you might be important to someone else! You can't objectively measure that.   That's what we have the voting system for. Popular questions rise to the top automatically. Very unpopular ones drop to the bottom.  I have been a passionate contributor until now, but if I know that my questions can be deleted anytime, (as well as my answers to deleted questions) I don't see any point in contributing my work. If I spend my time and it gets deleted, my work was completely in vain. There are few things I despise more in this world than senselessness. And creating something that is destroyed is the the ultimate senselessness.  I would recommend treating all work respectfully. Preserve information. This is like burning books. Please stop that, this is horrible. Thank you.  Questions are being deleted . Or for .

The system should search posts for the word "please" in proximity to the phrase "don't close" or "do not close", and if found together disable the close link for the following reasons:   They asked nicely They knew enough about the system to understand that posts can be closed, and thus are experienced enough to know when their own question is perfectly valid and reasonable   Please consider this question an opportunity to consider the issue carefully.  I'll convert it to a feature request when abs(votes) > 100, until then it'll merely be a discussion.