body1
stringlengths 20
4.1k
| body2
stringlengths 23
4.09k
|
|---|---|
If I'm playing Rocket League on my account and he's playing Skyrim which is on my account too, can we play at the same time? | My brother owns Skyrim on steam. We use Steam Family Share, but we were wondering how both of us could play it at the same time? |
I'm trying to find the mass of a spherical object with a given density function, and to do so I must solve this integral $$\int_{0}^{\pi}\sin^5{\theta}\cos^2{\theta}\ d\theta,$$ but no matter which method I choose (integration by parts, substitution, etc) I can't for the life of my figure out the anti-derivative. | Suppose $\displaystyle P(x,y)$ a polynomial in the variables $x,y$. For example, $\displaystyle x^4$ or $\displaystyle x^3y^2 + 3xy + 1$. Is there a general method which allows us to evaluate the indefinite integral $$ \int P(\sin x, \cos x) \text{d} x$$ What about the case when $\displaystyle P(x,y)$ is a rational function (i.e. a ratio of two polynomials)? Example of a rational function: $\displaystyle \frac{x^2y + y^3}{x+y}$. This is being asked in an effort to cut down on duplicates, see here: and here: |
When I describe my hobbies, should I write I play piano or I play the piano Are both forms acceptable? And how would you handle the phrase I am an amateur musician, playing the saxophone, guitar and piano. Should there be three "the" or only one? or none? | What is the rule for omitting/including the definite article in the following sentences: I used to play piano. I used to play the piano. I would pick the first sentence, but I've heard people say the second sentence even when they are not referring to a specific piano. Which one is correct? |
Latest Lion update broke a simple Geeklet osascript that used System Events to lookup of Background picture names. Running the associated command from the terminal returns the same name, every time, even though the picture is changing every minute. The code below worked for the primary display on my two headed Mac until this last update: osascript -e 'tell application "System Events" to get value of (property list item "LastName" of property list item "default" of property list item "Background" of property list file ((path to preferences as Unicode text) & "com.apple.desktop.plist"))' The secondary display has a hard-coded id where "default" goes; I've used the numeric IDs, everything I can think of. What is particularly annoying is a dump using just 'property list item "Background' in the above script shows the new file names with the appropriate "LastName". But running the script above always returns the same two names, the initial files shown in the Desktop/Screen Saver preferences. I'm not an AppleScript or System Events/plist guru, and any help would be appreciated. --UPDATE-- and some experimentation with the "defaults" command led to the following (less than ideal due to the embedded ids, but...) workaround: osascript -e 'tell application "System Events" to get value of (property list item "LastName" of property list item "722492885" of property list item "" of property list item "spaces" of property list item "Background" of property list file ((path to preferences as Unicode text) & "com.apple.desktop.plist"))' I'm certainly open to more elegant solutions but they must reflect the changing filename with "Random" set in Desktop Preferences. I'd even like to see a more readable version of what is posted above - all one line. I'm sure there's better ways to lay this out! | Where does OS X store your current desktop picture? I read somewhere else that it was in /Library/Caches/com.apple.Desktop. But I don't have that directory. |
I want to estimate percentile statistics for time-series pairs $(t, y)$ over varying granularities of time (hour, day, month, etc) For example, if I have the following pairs (10:59, 3), (11:01, 2), (11:32, 5), the first point is part of a different hour window, but all three are part of the same day window. When a new point arrives, I am recomputing the hour window statistics directly, by iterating over all data points in the window. Unfortunately, this does not scale to the longer time windows. Is there a way to incrementally update the statistics for the longer time windows? | I want to estimate the quantile of some data. The data are so huge that they can not be accommodated in the memory. And data are not static, new data keep coming. Does anyone know any algorithm to monitor the quantiles of the data observed so far with very limited memory and computation? I find useful, but it does not work very well for my data, which are extremely heavy-tailed distributed. |
I'd like some intuition on a question that has long confused me. Suppose we have a data-generating process $$y_i = x_i' \beta + \varepsilon_i $$ where $\mathbb{E}[\varepsilon_i] = 0$, $\varepsilon_i \perp x_i$, and $\varepsilon_i$ is drawn i.i.d. from a probability distribution $U$. When we regress $y$ on $x$ in a finite sample, we will get a set of residuals $\hat{\varepsilon}_i$. My question is, do these residuals tell us anything about $U$? It seems obvious that the greater the variance of $U$ (i.e. when the DGP is noisier), the greater we can expect the empirical variance of $\hat{\varepsilon}_i$ to be, so clearly they must be somewhat related. Moreover, if you indeed had $y$ and $x$ for the entire population, there would be no estimation error, so the empirical distribution of $\hat{\varepsilon}_i$ would match $U$ exactly. So, for finite samples, what can residuals tell us about the shape of the unknown distribution $U$? | Suppose that we have a model $Y_i = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik} + \epsilon_i$. Regression has a number of assumptions, such as that the errors $\epsilon_i$ should be normally distributed with mean zero and constant variance. I have been taught to check these assumptions using a normal QQ plot to test for normality of the residuals $e_i = Y_i - \hat{Y}_i$ and a residuals vs. fitted plot to check that the residuals vary around zero with constant variance. However, these tests are all on the residuals, not the errors. From what I understand, the errors are defined as the deviation of each observation from their 'true' mean value. So, we can write $\epsilon_i = Y_i - \mathbb{E}[Y_i]$. These errors cannot be observed by us. * My question is this: how good of a job do the residuals do in mimicking the errors? If the assumptions appear to be satisfied on the residuals, does this mean they are satisfied on the errors too? Are there other (better) ways to test the assumptions, like fitting the model to a testing dataset and getting the residuals from there? * Furthermore, does this not require that the model is specified correctly? That is, that the response really does have a relationship with the predictors $X_1, X_2,$ etc. in the way specified by the model. If we are missing some predictors (say, $X_{k+1}\ \text{to}\ X_p$), then the expectation $\mathbb{E}[Y_i] = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik}$ would not even be the true mean, and further analysis on an incorrect model seems pointless. How do we check whether the model is a correct one? |
Randall Munroe posted an interesting in which he claims that you can't use moonlight to light a fire, because it is impossible for reflected light to raise the temperature of an object higher than that of the reflecting surface, which of course is obviously false. I continued thinking about the problem, and read a couple of on the topic, and I'm not asking (as those questions do) whether it is possible, as it clearly is, but how you could do it. So, here is the scenario: You are in an open plane with no obstructions (trees, clouds, buildings etc) between you and the sky. The moon is full. You can magically suspend a lens of any size and shape anywhere between you and the moon (but any sunlight that hits it mysteriously vanishes - moonlight only!). You are attempting to set fire to a piece of paper. How big would the lens need to be to achieve this? | You can start fire by focusing the sunlight using the magnifying glass. I searched the web whether you can do the same using moonlight. And found and - the first two in Google search results. What I found is the thermodynamics argument: you cannot heat anything to a higher temperature using black body radiation than the black body itself, and Moon isn't hot enough. It may be true, but my gut feelings protest... The larger your aperture is, the more light you collect, also you have better focus because the airy disk is smaller. So if you have a really huge lens with a really short focus (to keep Moon's picture small), or in the extreme case you build a Dyson-sphere around the Moon (letting a small hole to the let the sunlight enter), and focusing all reflected light into a point it should be more than enough to ingnite a piece of paper isn't it? I'm confused. So can you start fires using the Moon? |
IDE: Microsoft SQL Server Management Studio Mistakenly I have cleaned a table data using delete from table tblBookData and now it has cleaned that table, please tell me is there any way to get back that data? If yes than please tell me the process, as I have studied there is a way to get back data if we have not closed the session. | I mistakenly deleted around 2,000,000 records from a remote SQL Server 2008 table. The server is not granting me access to the backup files on the server side. Is there any way to get back these records? |
If I generate a Normal and leptokurtotic continuous probability distribution (pdf), how can I measure the mass of these pdf's? If both pdf's have the same number of sample observations, but obviously have different statistical moments, can we expect that the area/mass that these two distributions enclose be different or identical to one another? How does the concept of pdf mass compare to the concepts and estimation of pdf moments and shape? | If we minimize the Wasserstein loss, $$W_1 (P_S, P_T) = \underset{\gamma \in \Pi}{\text{min }} \sum_{x,y} |x-y|\gamma(x,y)$$ which means we are looking for the coupling $\gamma(x,y)$ that minimizes the cost of moving mass from the source distribution $P_S$ to the target distribution $P_T$, Do the masses of the source and target distributions have to be identical? If so or not, how are the masses of $P_T$ and $P_S$ accounted for mathematically in, or when minimizing, the shown formula, or what might be missing/overlooked by the Wasserstein approach overall due to the mass differences? |
In Mathias' paper Hilbert, Bourbaki and the scorning of logic (see ), he mentions Hilbert's $\varepsilon$-calculus (and thus Bourbaki's $\tau$-calculus) is not suitable for incomplete systems. But he did not elaborate if there is any real problem (like inconsistency or incapability) with it. Obviously Hilbert hoped to use $\varepsilon$-calculus to prove the completeness of systems like ZFC, and failed as we know. But this does not means $\varepsilon$-calculus itself has any problems. So, is Mathias' criticism out of his personal flavor of logic and educational reasons, or there is any real problem for $\varepsilon$-calculus in incomplete systems? | In Mathias' paper Hilbert, Bourbaki and the scorning of logic (see ), he mentions Hilbert's $\varepsilon$-calculus (and thus Bourbaki's $\tau$-calculus) is not suitable for incomplete systems. But he did not elaborate if there is any real problem (like inconsistency or incapability) with it. Obviously Hilbert hoped to use $\varepsilon$-calculus to prove the completeness of systems like ZFC, and failed as we know. But this does not mean $\varepsilon$-calculus itself has any problems. So, is Mathias' criticism out of his personal flavor of logic and educational reasons, or there is any real problem for $\varepsilon$-calculus in incomplete systems? |
Your honor, My lord, Your highness, My lady all refer to another person. What are the rules behind that? The striked-out questions are answered by . Thank you guys! Why do we use "Your" while sometimes use "My"? First, let's say, Tom is my friend. I would say "My friend, would you like a coffee?" It would be weird if I say "Your friend, would you like a coffee?" Why don't we use "Your friend" like "Your honor"? Second, I feel it looks like Apposition if I interpret "Your honor" as "You, honor". Why do we use the possessive form? Third, say I'm a loser. I would like to coin an honorable form for other people to call me. Which is more correct, "Your loser" or "My loser"? I'm particularly interested in the usage in the United States if there's any difference. | Why is it "your Majesty", but "my Lord"? |
Dictation provides a great way of entering text. However, the documentation I found so far is scarce, and for instance I do not know what the blue dots underlying some parts of the text: For instance, is it possible to chose an alternate text (solution)? Note: I tried any possibility as , but no luck there... | I know that the dotted blue underlined words during dictation in OS X are supposed to provide alternative suggestions of the voice transcription. However, when I control-click or right-click the blue underlined words, I do not see any suggestions or alternatives. Please help! I am running the GM of OS X Mavericks...been running Mavericks since beta seed 4. Also, I use a magic trackpad, not a mouse (just in case this matters). Is this just a Mavericks bug or am I doing something wrong? |
I was trying to install Ubuntu14.04.1 using Unetbootin. I downloaded the .iso file and followed the steps as outlined in the official tutorial. However after I select the Unetbootin option from the boot options, nothing happens. It gets stuck at this screen , which says Try (hd0,0): FAT16: No UBNLDR Try (hd0,1): NTFS5: _ After searching the web for this issue, I couldn't find anything conclusive. Am I missing something here? Also, the .iso image that I downloaded has the name "ubuntu-14.04.1-desktop-amd64 ". Can this be the cause of this? My system is a Win7 system with Intel Centrino, 3GB RAM. I found a thread where somebody posted about the issue in Vista, and it mentioned setting the boot device correctly. I tried to run the bcdedit command, but I'm not sure how to get the GUID of Unetbootin. I saw another thread with the same issue that is currently unanswered : Can somebody help me here. | I would like to see a full how-to guide on how to install Ubuntu. |
I started 2 new sites at pretty much the same time. They are both small blogs, running the exact same blogging software (even the same template). The content is different, of course. One of them was indexed in Google 3 days after launch. The other one has not been indexed at all. It gets visited by Googlebot 1-2 times a week, but it won't show up in search results, even if I do a "site:www.example.com" search. Is this normal? | This is a general, community wiki question and answer pair intended to address any questions concerning the reasons a site or specific site contents do not appear in search engine results. If your question was closed as a duplicate of this question and you feel that the information provided here does not provide a sufficient answer, please open a discussion on . My site (or specific pages on my site) is not appearing in search engine results. Why isn't my content indexed and what can I do about it? |
<?php $str='表/test.zip'; $str = mb_convert_encoding($str,"SJIS−win","UTF−8"); readfile(str); ?> I got error with character 表. Error message is: Warning: readfile(•\/test.zip): failed to open stream: No such file or directory in check.php on line 22 •\/test.zip Of course 表/test.zip had already existed. I tried with other character except for text 表, all were OK, did NOT have any error. Does anyone have any solution? Thank you very much for your help. Note: It is not error about name of file, but error about name of path, name of folder is in JP. It is difference with | I have the following code <?php if ($handle = opendir('C:/xampp/htdocs/movies')) { while (false !== ($file = readdir($handle))) { if ($file != "." && $file != "..") { echo $file."<br />\n"; } } closedir($handle); } ?> When it does have mb language such as japanese, it doesn't display properly instead it display like kyuukyoku Choujin R ?????~? rather then kyuukyoku Choujin R 究極超人あ～る Anyway to make it display the correct name or make it still download-able by others? Thanks for helping me :) |
When replying to a user in a comment, their name is automatically suggested in a pop-up: But that only works if they have already left a comment. Sometimes I want to notify a user who has made a , but there no pop-up that suggests the name of these users: Does the user still get a notification of the comment if you manually type in their username? Edit I have changed this to a feature request, instead of posting a new question. Is this OK? | @username auto-completion for comments was , and is already active on MSO. However, it only seems to auto-complete the usernames of people who have commented on the post. According to , the list of users who can be explicitly notified also includes: Anyone who edited the post Anyone who started a bounty on the question The ♦ moderator or who cast a binding close vote on the question Why not auto-complete those, as well? |
My textbook says "Let $X$ and $Y$ be sets. We say $X$ and $Y$ have the same cardinality if there is a bijection $f: X \to Y$." I was wondering why the text does not say "if and only if." A bijection implies same cardinality, but does cardinality imply bijection? I would imagine so. | In some books the word "if" is used in definitions and it is not clear if they actually mean "iff" (i.e "if and only if"). I'd like to know if in mathematical literature in general "if" in definitions means "iff". For example I am reading "Essential topology" and the following definition is written: In a topological space $T$, a collection $B$ of open subsets of $T$ is said to form a basis for the topology on $T$ if every open subset of $T$ can be written as a union of sets in $B$. Should I assume the converse in such a case? Should I assume that given a basis $B$ for a topological space, every open set can be written as a union of sets in $B$? This is just an example, I am not asking specifically about this sentence. |
I have set up a model in Blender and started refining material properties, lighting etc. around some imported geometry. It is looking good, but I would like a surface to represent the light scattering of woven carbon fibre. I have found an of a very good approximation, though I haven't yet fully figured out how it works. It works using Cycles renderer. When I switch to Blender's renderer in this project essentially nothing gets drawn (uniform grey). However when I switch my model to Cycles renderer nothing (still uniform grey) also gets drawn. It seems like there is a fundamental difference in modelling strategy bewteen the two renderers. How can I move from one technology to the other? How can I know whether a technology I am trying to use is meant for one renderer or the other? Would it make more sense if there were two versions of Blender built around each renderer and only exposing the features that work with each? Perhaps the differences aren't as large as I'm suggesting. Edit: I think the bigger question here is how I can know whether some tool I'm using is or is not compatible with the chosen renderer. As per the comments it seems that the internal renderer is being deprecated and Cycles or eevee is going to become king, how can I know I'm using the technologies compatible with it, without trial-and-error, use it, change it, render, see what happens? | I know this may be a tough or confusing question, but I have numerous existing materials I created and reuse for a project, which were all prepared for Blender Internal. Now, I want to start the transition to Cycles, but I've hit a roadblock. How can I transition my materials without completely starting over? Or should I just forget it and start with fresh materials? |
So i just purchased a linux (centos) server with /64 IPV6 subnet. I want to use these IP's for outgoing requests especially. How on earth can we add that many IP addresses to the network interface? Are there any workarounds for this? | I know that the ip tool lets you bind multiple addresses to an interface (eg, ). Right now, though, I'm trying to build something on top of IPv6, and it would be really useful to have an entire block of addresses (say, a /64) available, so that programs could pick any address from the range and bind to that. Needless to say, attaching every IP from this range to an interface would take a while. Does Linux support binding a whole block of addresses to an interface? |
I'm in the 11th grade. At the bachelor exam, my main focus will be on mathematics and informatics. I'm a hard working man, but due to the school norms, I can consider myself idiot at math. Why? Because the math that's studied at school is rubbish. It makes you reproduce, and not think. I'm also tutored at math, but with the same results. I want to go on the same way I went with informatics, and this is by learning in private, alone. Could you recommend me some books that can help me understand the whole high-school curriculum? A book/books that takes me from the very below (9th grade) till 12th grade? | I am a student of 11th grade and i have completed the syallabus of both 11th and 12th grade maths with complete understanding and it was possible coz of the love for this subject that i have. I don't want to sound "larger than life" here, but my curiousity has now increased to learn maths at a deeper level. As of now i am reading "Linear algebra done right" by Axler. Thats an amazing piece of work and now i truly understand what "matrix" is all about. I also want to extend my knowledge on the following topics : 1) Algebra (groups,subgroups,homomorphisms etc) 2) Analysis 3) Geometry/Topology Why i am here is because i wanted you guys to recommend a book on each of the above topic that would be appropriate for a beginner like me (I must mention here I have been working on Apostol's volume 1 calculus, thats a great text, but for a beginner, its best if the concept is explained in a broad manner and in as simple and easy words as possible) . I just want a book which explains the concept broadly rather than coming to the conclusion directly (which is not a great sight for a beginner like me) . Having said that, no book is complete i understand. Thats why i am asking your recommendation as you guys are aware which text would be the best to start with for a beginner. I have searched on the net about this, but there are dozens of works available, and out of them all , i want the one which is the best (approximation) for a beginner . Please don't misunderstand me in any way. I am just confused which text to go for, and i understand the books which u may suggest may be for undergraduate level course as these topics are for undergraduate level courses, thats not a problem at all . I need a easy to learn (i mean easy in terms of "broad" explanation) book. I hope you guys don't mind me questioning such a question on this forum . Thanks for all the help you guys have been providing me on this forum . Maths Maths Maths... the world is beautiful coz of u! :)) |
I'm writing a book class document and use the appendix package also. I'm having some problem with the table of contents and the appendix section that appears in the ToC. So, in the table of contents contents I have : 1 chapter_name 2 chapter_name 3 chapter_name A appendix_name B appendix_name What I would like to have is instead : 1 chapter_name 2 chapter_name 3 chapter_name appendix_name appendix_name I'm not able to remove the "A" and "B" letters from the ToC. Maybe because of the book class? Anyone that can please help me with this problem? Thanks very much, Michele. Edit1: I'm my thesis now I solved the problem but with this code the problem still exists. I'm still trying to understand differences between my thesis and the code that follows. Edit2: I was freaking out but I found a workaround to the problem (but now I wouldn't say the problem is 100% solved). The trick is compile the code that follows, than comment the line \backmatter and recompile the code. In this way the first letter "A" and "B" disappeared. If you recompile for a second time the code with %\backmatter the problem of letters magically reappears! \documentclass[a4paper,10pt]{book} \usepackage[utf8]{inputenc} \usepackage[titletoc]{appendix} \usepackage{lipsum} \begin{document} \tableofcontents \cleardoublepage \mainmatter \chapter{Chapter 1} \lipsum \chapter{Chapter 2} \lipsum \chapter{Chapter 3} \lipsum \chapter{Chapter 4} \lipsum \backmatter \appendix \begin{appendix} \chapter[Appendix A]{Appendix A} \lipsum \end{appendix} \begin{appendix} \lipsum \chapter[Appendix B]{Appendix B} \end{appendix} \end{document} | I am a newbie in Latex. My goal is to have the word "Chapter" in the title of any chapter, and the word "Appendix" in the title of appendix. I also want to add "Appendix" in TOC. However, using the following MWE from my university, I end up having "Appendix A" in TOC. How can I remove the letter "A" in TOC. \documentclass[12]{thesis} \RequirePackage{tocloft} \RequirePackage{titlesec} \usepackage[titletoc]{appendix} \newcommand{\spacemultiplier}{1.5} \renewcommand{\baselinestretch}{\spacemultiplier}\normalsize \renewcommand{\frontmatter}{ %TABLE OF CONTENTS \addcontentsline{toc}{chapter}{Contents} {\renewcommand{\baselinestretch}{1}\normalsize \tableofcontents } \newpage \titleformat{\chapter}[display]{\renewcommand{\baselinestretch}{1.5}\LARGE\sc\fillast}{Chapter \thechapter}{0pt}{}[\renewcommand{\baselinestretch}{\spacemultiplier}\normalsize] \titlespacing{\chapter}{0pt}{1.4cm}{20pt} \setcounter{chapter}{0} } % Appendix setup \newcommand{\universityappendix}{ \appendix \titleformat{\chapter}[display]{\renewcommand{\baselinestretch}{1.5}\normalsize \LARGE\sc\fillast}{Appendix}{0pt}{} \titlespacing{\chapter}{0pt}{-30pt}{20pt} \renewcommand{\baselinestretch}{1.5}\normalsize } \begin{document} \frontmatter \chapter{blah blah} This is a chapter \universityappendix \begin{appendices} \chapter{blah blah} this is appendix \end{appendices} \end{document} Thanks |
I´m having some troubles while inserting words with tildes and special characters from a csv in my MYSQL database. That´s what I see in my DB: And I should see this: I put this in my HTML: <meta charset="utf8" /> and this in my PHP: mysqli_query($db_conexion,"SET NAMES utf8"); if (!$db_conexion->set_charset("utf8")) { printf("Error changing the utf8 character set: %s\n", $db_conexion->error); } else { printf("Current character set: %s\n", $db_conexion->character_set_name()); } and it´s returning me "Current character set: utf-8" so I don´t understand why it´s inserting wrong... any help is welcome! | I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1. Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur? This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2. |
What is the difference between the GET and POST form method except one(GET) send data from URL and post send directly ? And if i use SSL then should i choose only post since get wont work ? | What's the difference when using GET or POST method? Which one is more secure? What are (dis)advantages of each of them? () |
There is raw echelon form and reduced raw echelon form: The row echelon form is used to solved the system of linear equations. What is the practical use of reduced raw echelon form? Previous question in the forum was related to row echelon form (and not to reduced row echelon form): Thanks | I have just started auditing Linear Algebra, and the first thing we learned was how to solve a system of linear equations by reducing it to row echelon form (or reduced row echelon form). I know how to solve a system of linear equations using determinants, and so the using row echelon form seems to be very inefficient and an easy way to make mistakes. The lecturer seemed to indicate that this will be useful in the future for something else, but a friend who has a PhD in mathematics said it is totally useless. Is this true? Is this technique totally useless or is there some "higher mathematics" field/ technique where row echelon form will be useful? |
As I asked above is it possible to create template file for specific node id. I now we can create template file for content type, but not clear for node id. E.g. Suppose there are 10 Articles in website, each has node id from 1-10. Now question is I want to create template file for node id 3. When user visit article node id 4, then user will see different page. | I'm trying to define a custom template file for a specific node, using the node ID. I read a lot of topics saying to create a node--X.tpl.php file in the templates folder. That's what I did; unfortunately, even after flushing the theme cache many times, nothing changes. Is there anything more I have to do? I am using Drupal 7. |
Was wondering why Area51 doesn't show rep change like the other sites? 'Tis rather annoying having to go to Area51 to see that you've got a change in rep. | The new Top-Bar does not show reputation changes from Area 51. |
In the past 2 years I was granted 10 Schengen Visas from Belgium, Greece, Portugal, Switzerland and France (in December 2018) In February 2019 I applied for a French Visa in the USA & was denied with the following reason: "not convinced of your intention to return" to the USA. The documents & purpose of the trip was the same in December 2018 and February 2019, no difference at all. First visa was approved and I visited France & returned after 7 days, did not of course overstay my visa. The second visa was refused! Anyone experience the same situation? What was the solution? Should I re-apply? Apply for another Schengen visa (not France)? Appeal the decision? | Over the course of time here on TSE, I have observed individuals whose pattern of visa applications is best described as ''... serial refusals - Two or more consecutive visa refusals issued by the same regime to the same person. Commonly for the same, or nearly the same, reasons. In some visa regimes Serial refusals can have a cumulative effect wherein the applicant's credibility is increasingly eroded, especially when the application pattern suggests a secondary agenda. A common thread appears to be the need to visit the destination country (especially Schengen, the USA, or the UK) with a special sense of urgency. Also common in these cases are the following types of questions... Should I just reapply once again? What are my chances? What can I do to improve my odds in the future? Can I somehow address the previous refusals to avoid them being a burden on all future applications? How can I break the pattern? NB: This question is intended as a canonical about serial refusals. I have never been personally denied a visa. |
When I run sudo apt-get update this is my output: Err:1 http://security.ubuntu.com/ubuntu xenial-security InRelease Temporary failure resolving 'security.ubuntu.com' Err:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease Temporary failure resolving 'us.archive.ubuntu.com' Err:3 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease Temporary failure resolving 'us.archive.ubuntu.com' Err:4 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease Temporary failure resolving 'us.archive.ubuntu.com' Reading package lists... Done W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial/InRelease Temporary failure resolving 'us.archive.ubuntu.com' W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease Temporary failure resolving 'us.archive.ubuntu.com' W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease Temporary failure resolving 'us.archive.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease Temporary failure resolving 'security.ubuntu.com' W: Some index files failed to download. They have been ignored, or old ones used instead. I'm new to servers and have run into this issue. I've managed to get SSH up and running and am attempting to install Apache. Nothing will install. I am new to Linux servers. I have only worked with Windows Servers before. Let me know if any other info would be helpful. | Err http://archive.canonical.com natty InRelease Err http://security.ubuntu.com oneiric-security InRelease Err http://extras.ubuntu.com natty InRelease Err http://security.ubuntu.com oneiric-security Release.gpg Temporary failure resolving ‘security.ubuntu.com’ Err http://archive.canonical.com natty Release.gpg Temporary failure resolving ‘archive.canonical.com’ Err http://extras.ubuntu.com natty Release.gpg Temporary failure resolving ‘extras.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric InRelease Err http://gb.archive.ubuntu.com oneiric-updates InRelease Err http://gb.archive.ubuntu.com natty-backports InRelease Err http://gb.archive.ubuntu.com oneiric Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com natty-backports Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ Reading package lists... Done W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/InRelease W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/InRelease W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/InRelease W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/InRelease W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/InRelease W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/InRelease W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/Release.gpg Temporary failure resolving ‘archive.canonical.com’ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/Release.gpg Temporary failure resolving ‘security.ubuntu.com’ W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/Release.gpg Temporary failure resolving ‘extras.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/Release.gpg Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Some index files failed to download. They have been ignored, or old ones used instead. This is what I'm seeing when I try to run sudo apt-get update. I did an update on my instance yesterday and am now experiencing this. |
I want to find the 25th, 50th, and 75th percentile of this data-set. data-set: Am not sure how one uses the cumulative frequency percentage in order to derive what the 25th,50th, and 75th percentiles are. I am guessing for the 50th, as I know this is generally the median, or middle number but I cannot be sure this is where 50% of the data clusters. But I would guess that p_50 = 36.6% and therefore would be on line 5. So the median would be at 5 or at 36.6% with 605 cumulative frequency Please help | Here is the data-set: I understand that the cum per sums all the previous data up until that point. So 153 / 1655 = 19.8%, or if looking at the cum freq a total of 328 people scored 4 or less on the vocabulary test. But how does one determine if this is the 25th percentile? At what point in the range of cum per would one know it it's the 25th percentile, 50th percentile or 75th percentile? Please help Thank you |
In my training as a Certified Flight Instructor, I am required to teach Lift Theory. While simple explanations have sufficed in the past, as I progress in my training and understanding, I want to be able to understand lift in greater detail. During my last lesson, I stumped my Instructor. I asked about the cause of the increased velocity above an airfoil and he could not explain it so I am trying to research it and come to some clear understanding. I have a hunch described below. Please let me know in semi-layman terms if I am on the right track. Known: As Velocity increases, Pressure decreases and vice versa. (Bernoulli) The air moving across the top of an airfoil moves faster than the air below the airfoil. Some have said that this is because the air above has a farther distance to travel but this has been proven untrue. Higher pressures below the airfoil and lower pressure above the airfoil create a portion of the lifting force of the airfoil. Additional lift forces are created by air being directed down by angle of incidence and the shape of the wing (Newton). This occurs from the air running into the bottom of the wing and being forced downward. Lift is also occurring because the air above is moving at a higher velocity than the air below, and when they meet at the trailing edge, the faster air pushes the slower air downward. (Vortices) From the Cambridge University video (see References) showing time-lapse video, we see that the air above the airfoil moves faster such that it reaches the trailing edge sooner than air below the airfoil. Unknown: This proves that the air over the airfoil moves faster but what is the cause for that air to move faster? My Hypothesis: Because of the angle of incidence and angle of attack to the relative wind, a higher pressure is created upon impact at the separation. This upper airfoil high pressure is considered ‘high’ relative only to the air pressure at other areas of the upper airfoil such as the center of pressure or the trailing edge of the wing. (It is not meant to be considered ‘higher’ pressure than the air under the airfoil. Also due to angle of incidence and angle of attack, an even lower pressure is created at the trailing edge of the wing. Attached is a screen shot of the Cambridge video, with my hypothetical pressures jotted in. Because high pressure air always seeks lower pressure air, the air above the airfoil should get an extra push and accelerate to a velocity faster than that of the air under the airfoil. I found (see attached) a diagram of Pressure Coefficient distribution across airfoil geometry. This diagram is from an unrelated paper treating a separate subject of shapes of trailing edges. It however is the only graph I could find detailing what pressures occurred where on the airfoil. References: 1 Cambridge University video 2 Morphing Trailing Edges with Shape Memory Alloy Rods. November 2002 URL: 1st Silvestro Barbarino 15.46 · Sikorsky Aircraft 2nd Wulf G Dettmer 3rd Michael Ian Friswell 45.16 · Swansea University | I understand the common explanation of lift, which describes the airflow over the top of the wing as moving faster than the air below the wing. However, I don't quite understand why the air moves faster. I've read some explanations citing a circulation effect among others, but haven't found a good, clear explanation for the exact cause. Can someone help me out? |
I have a non-blocking Timer class that: counts down from whatever int the class is instantiated with each new instance of the class waits for any timer that is currently running to first finish before they start counting down Current Design of class: class Timer{ private: std::thread *thread; public: Timer(const int &timer, std::mutex *mutex){ this->thread = new std::thread( [&timer, mutex](){ mutex->lock(); std::cout<<"Counting to: "<<timer<<std::endl; for (int i=0; i < timer; i++) { std::cout<<i<<std::endl; sleep(1); } std::cout<<"Time is up"<<std::endl; mutex->unlock(); }); } ~Timer(){ this->thread->join(); delete this->thread; } }; I am calling it from main with this: int main() { std::mutex mutex; Timer time(3, &mutex); Timer newTime(9, &mutex); //Do something else in the meantime ... return 0; } Quesion: I would like to simplify the main by internalising the mutex as a static variable of the class. Something like this: a simpler main int main() { Timer time(3); Timer newTime(9); //Do something else in the meantime ... return 0; } a more representative Timer class: class Timer{ private: std::thread *thread; static std::mutex timerMutex; public: Timer(const int &timer){ this->thread = new std::thread( [&timer, this](){ timerMutex.lock(); std::cout<<"Counting to: "<<timer<<std::endl; for (int i=0; i < timer; i++) { std::cout<<i<<std::endl; sleep(1); } std::cout<<"Time is up"<<std::endl; timerMutex.unlock(); }); } ~Timer(){ this->thread->join(); delete this->thread; } }; How can I do this ? Current Error: error: linker command failed with exit code 1 | Can anyone explain why following code won't compile? At least on g++ 4.2.4. And more interesting, why it will compile when I cast MEMBER to int? #include <vector> class Foo { public: static const int MEMBER = 1; }; int main(){ vector<int> v; v.push_back( Foo::MEMBER ); // undefined reference to `Foo::MEMBER' v.push_back( (int) Foo::MEMBER ); // OK return 0; } |
Hello we will be travelling onwards from San Francisco on the 30th of June and will return on the 2nd evening. We would like to leave our heavy luggage behind and travel light. What are the options of storing luggage at the airport, as we will be boarding a midnight flight on 2nd to Boston | My plane from SFO back to Germany leaves at 10 p.m. tonight, I thought I'd take an Uber from my Hotel in San Jose to the airport early, lock up my baggage there and then go downtown to explore the city. Are there baggage lockers available at the San Francisco International Airport? If yes, where are they located? My flight leaves at the International Terminal G. |
There are two independent RVs $X \sim \mathcal{U}(-1,5)$ and $Y \sim \mathcal U(-5,5)$. Let $A = \{ X \ge Y \land Y \ge -1 \land Y \le 1\}$ and $B = \{ X \le 1\}$. What is $\mathbb P (A | B)$? My idea is to apply Bayes' rule, i.e. $$ \mathbb P(A|B) = \frac{\mathbb P(B|A) \mathbb P(A)}{\mathbb P(B|A)\mathbb P(A) + \mathbb P(B|\lnot A) \mathbb P(\lnot A)}$$ I understand that this works nicely as long as $\mathbb P(B|A)$ is easier to compute. However, I find that $$ \mathbb P(B|A) = \frac{\mathbb P(A|B) \mathbb P(B)}{\mathbb P(A|B)\mathbb P(B) + \mathbb P(A|\lnot B) \mathbb P(\lnot B)}$$ ... which I feel does not bring me closer to the solution. The unconditional probabilities are fairly straight forward, but the conditional ones keep piling up. How should I procede from there? | Given two independent random variables $X \sim \mathcal{U}[-1,5]$ and $Y \sim \mathcal{U}[-5,5]$, what is $$\mathbb{E}\{Y - X | X \le 1, Y > X, Y \in [-1,1] \}\,?$$ I managed to compute the respective probability $$ \mathbb{P}\{ X \le 1, Y > X, Y \in [-1,1] \} = \mathbb{P}(X \le 1) \mathbb{P}(Y > X) \mathbb{P}(Y \in [-1,1]) = 1/3 * 1/2 * 1/5 = 1/30$$ How do I continue from there? |
In JavaScript, I have dates in an array ( named aLabels) that looks like: /Date(1485703380827)/,/Date(1485703410233)/,.... to 96 entries. How to I convert/ format them so I can use them in a label? I tried: Looping through the array to try to format each date. But for each iteration, before I am able to modify it, I get: Invalid Date. // Create a holding array. var formatttedDateTime = new Array(); // Loop thru the label array to format each entry into a formatted data/time. for (i = 0; i < aLabels.length; i++) { var utcDateVal = new Date(aLabels[i]); // For testing. alert("original date " + utcDateVal); var actualDate = new Date(utcDateVal.getTime() + (utcDateVal.getTimezoneOffset() * 60 * 1000)) // Load the formatted date/time array. formatttedDateTime[i] = actualDate; } | I'm taking my first crack at with jQuery. I'm getting my data onto my page, but I'm having some trouble with the JSON data that is returned for Date data types. Basically, I'm getting a string back that looks like this: /Date(1224043200000)/ From someone totally new to JSON - How do I format this to a short date format? Should this be handled somewhere in the jQuery code? I've tried the jQuery.UI.datepicker plugin using $.datepicker.formatDate() without any success. FYI: Here's the solution I came up with using a combination of the answers here: function getMismatch(id) { $.getJSON("Main.aspx?Callback=GetMismatch", { MismatchId: id }, function (result) { $("#AuthMerchId").text(result.AuthorizationMerchantId); $("#SttlMerchId").text(result.SettlementMerchantId); $("#CreateDate").text(formatJSONDate(Date(result.AppendDts))); $("#ExpireDate").text(formatJSONDate(Date(result.ExpiresDts))); $("#LastUpdate").text(formatJSONDate(Date(result.LastUpdateDts))); $("#LastUpdatedBy").text(result.LastUpdateNt); $("#ProcessIn").text(result.ProcessIn); } ); return false; } function formatJSONDate(jsonDate) { var newDate = dateFormat(jsonDate, "mm/dd/yyyy"); return newDate; } This solution got my object from the callback method and displayed the dates on the page properly using the date format library. |
With high-resolution monitors becoming more popular, does the StackExchange team have any plans to make these websites use more display area when the browser is maximized/fullscreen? Currently, I am using a full HD display (1920x1080). Only about 3/7 of the width of my display is used on StackExchange sites: --------------------------------------------------------------------------------- | || || | | || || | | || || | | || || | | || || | | <---- UNUSED ----> || <------------ 960px ----------> || <---- UNUSED ----> | | || || | | || || | | || || | | || || | | || || | ... --------------------------------------------------------------------------------- In addition, with current 2560w displays and future high-resolution displays, the amount of unused space is greater than the space used to display content. In my opinion, the horizontal layout should be fluid - proportionally adjusting to the width of your browser window to maximize the use of your display. It probably shouldn't expand to fit the entire width of the window, because that would require users constantly turn their heads to view all of the content. This has valid arguments: (1) I like being able to size my browser window to hide the panel on the right without losing question/answer size now and then (mainly when I'm working on two things at once). (2) I like knowing approximately how my answers will look in terms of paragraph size and so forth. (3) I like knowing that syntax highlighter wrapped things correctly. (4) Mostly, I like that this helps encourage brevity in code samples - if the sample is long enough that you're losing code for nesting reasons, it's time to re-focus your thoughts and pare down to just what's relevant to the problem. My counter-arguments: (1) Add a "collapse side panel" feature that remembers your preference. (2) Why does this matter? A high-quality answer will contain only relevant and necessary information. (Maybe restrict post length for new users?) Also, see point (3) below. (3) Never depend on the code formatter correctly wraping/indenting code. You can preview posts below the editor anyway. (4) This will happen in posts regardless of the width of the page. Even with this 960px-wide page, some users constantly dump entire programs into a post. See parenthetical in point (2). Does the community have any thoughts or suggestions on this matter? | When will SO stop wasting real estate of my screen by having static width layout? EDIT It would be very interesting to hear how does Joel, being UI specialist, feel about this. JoelOnSoftware site has fluid layout... |
say we have a fixed table T. Is there a unique normalized version of T, i.e., does the/a correct normalization, say up to 3NF produce a unique table up to some equivalence? Basically, I am trying to find out how many different correct ways of normalizing a table there are. Thanks. | I"m studying normalization and have been reading through descriptions and examples online. One Concept that isn't clear to me is if the process can be automated at any point. I understand that a system can't tell you if you schema makes any real-world sense, but it seems likely to me that if you feed a program some arguments say, the functional dependencies, it would be able to do some steps for you. Say you have a relationship R(A,B,C,D) and you tell your program that A,B->C and A->D and that the primary key is (A,B) Now if my understanding serves me correctly it should be possible for a program to identify that A->D violates 2NF because D depends on A and A is a subset of the primary key. That the proper decomposition would be R1(A,B,C) and R2(A,D). The main book i'm learning from and my instructor indicate these normalization's are done all by hand. Is this correct or can some parts be automated? |
I have Ubuntu 15.04 and windows 8.1 dual booted in my dell laptop, whenever I boot my Ubuntu OS i have to manually click on the drive [say D drive on windows] to mount and open it. So all i have to do is keep those drive mounted permanently and I cannot even unmount or eject them like in windows. | I have two partitions that I want to mount on startup: /dev/sda3 /mnt/devel ext4 defaults 0 2 /dev/sda2 /mnt/excess ntfs defaults 0 2 The ext4 partition mounts fine (owned by me, writable only by me), but the NTFS mounts owned by root with R\W permission for all. How to fix this? drwxr-xr-x 7 amanda amanda 4096 2012-03-14 19:07 devel drwxrwxrwx 1 root root 4096 2012-03-14 22:38 excess |
Why am i getting dents all of a sudden while using subdivision surface modifier? And also i did not use mirror modifier. | I tried to subsurf this model that I mirrored but when I use subsurf it splits the model into two objects. Before Subsurf: After Subsurf: Any help would be appreciated. |
I am somewhat new to Linux networking and running in to a issue with iptables I am just not making any headway on. Two notes before I get in too it. iptables is version 1.4.14, and it is a custom embedded server using custom distro of Linux. The issues I am having is that -j REJECT parameter is unavailable. If I enter something like (as root) "iptables -A INPUT -p tcp --dport 80 -j REJECT" the error "iptables: No chain/target/match by that name." is returned. If I enter the same thing with -j DROP instead iptables accepts it and works without issue. So the question is what is missing in my installation that is causing this? Thanks. | I have recently setup a server with fail2ban, and it is mostly working except I am getting errors whenever this command tries to execute: sudo iptables -D fail2ban-ssh -s xxx.xxx.xxx.xxx -j REJECT --reject-with icmp-port-unreachable The error message is: iptables: No chain/target/match by that name. When I don't use REJECT, it works fine. For example: sudo iptables -D fail2ban-ssh -s xxx.xxx.xxx.xxx -j DROP Will execute just fine. I can't figure out why REJECT is being, er, rejected. |
Is it ok to leave the battery charging while it is being use? Or is it ok to keep the power plugged in with full charged battery while the laptop is in use? Can this shorten battery's lifespan? | When your laptop's battery is 100% charged, should you leave it plugged in so any battery power doesn't get used, or will that cause overcharging, overheating, etc.? Should the laptop be unplugged when the battery level is 100%? I'm asking because my laptop's screen tends to get dim when unplugged, so I don't like to run it on battery. |
I know that it is possible to read the basis for $\operatorname{Null}(A)$ and $\operatorname{Null}(A^T)$ by simply looking at the reduced row-echelon form (RREF) of the matrix $A$. I have only an approximate idea of how to do it. For example, if we $$A = \begin{bmatrix} 1 & 2 & 0 & -1 \\ 0 & 0 &1 &2 \\ 0 &0 &0 &0 \end{bmatrix},$$ then one of the basis vectors for $\operatorname{Null}(A)$ will be $\begin{bmatrix}-2 & 1 & 0 &0\end{bmatrix}^T$, and the other one will be $\begin{bmatrix}1 & 0 & -2 &1 \end{bmatrix}^T$. So, basically we're "going around" over eight digits and alternating signs. But I noticed that this method isn't perfect. Does someone have a better idea of how to read bases for these two spaces from the RREF of $A$? | The following text is written in my textbook and I don't really understand it: If $A = (a_{ij}) \in$ Mat$(m x N, F)$ is a matrix in reduced row echelon form with $r$ nonzero rows and pivots in the columns numbered $j_1 < ... < j_r$, then the kernel ker$(A)$ is generated by the $n-r$ elements $ w_k = e_k - \sum\limits_{1 \le i \le r, j_i \le k} a_{ik}e_{j_i}$ for $k \in {1, \cdots , n} \ {j_1, \cdots, j_r}$, where $e_1, \cdots, e_n$ are the standard generators of $F^n$. There are no computational examples and the notation is a bit overwhelming so I don't know how I can use it. Can somebody give an example of this in practice? |
Let $R$ be a ring. Set $M=\{ x\in R|\forall y\in R\Rightarrow 1-xy\;\; \text{unitary in}\; R\}$ and $J\left( R\right) =\cap \{ I|I\unlhd R, I \text{is a maximal ideal}\}$. How to show that $M\subseteq J\left( R\right)$? | I have in my notes that the Jacobson radical of a ring $R$ is: $J(R) = \cap${$I$ | $I$ primitive ideal of $R$} $= \cap$ {$Ann_R M$ | $M$ simple $R$-module}. I have now seen elsewhere that $J(R) = \{x ∈ R: xy-1 ∈ R^\times \text{ for all } y ∈R\}$ I was just wondering would anyone be able to provide an explanation as to how to get from one definition to the other? Thanks. |
Are there any reasons, apart from subjective visual perception and cases where you have multiple statements on the same line, to use semicolon at the end of statements in JavaScript? It looks like that there's plenty of evidence suggesting that use of semicolons is highly optional and is required in only few of the specific cases. | In many situations, JavaScript parsers will insert semicolons for you if you leave them out. My question is, do you leave them out? If you're unfamiliar with the rules, there's a description of semicolon insertion on the . Here's the key point: If the first through the nth tokens of a JavaScript program form are grammatically valid but the first through the n+1st tokens are not and there is a line break between the nth tokens and the n+1st tokens, then the parser tries to parse the program again after inserting a virtual semicolon token between the nth and the n+1st tokens. That description may be incomplete, because it doesn't explain @Dreas's example. Anybody have a link to the complete rules, or see why the example gets a semicolon? (I tried it in JScript.NET.) is related, but only talks about a specific scenario. |
Let $\Omega$ be any measurable ($\sigma$-finite, if necessary) space. let $1\leq p\leq\infty,x\in L^p(\Omega)$. Then how to proof $\forall\varepsilon>0,\exists\delta>0$，so that for any $1\leq q\leq\infty$, if $|q-p|<\delta$, we have $x\in L^q(\Omega)$ and $\left| ||x||_p -||x||_q\right|<\varepsilon$ | Suppose that $\|f\|_p < \infty$ for all $1\leq p < p'$, I want to know if the the following is true and in that case how to show it $p \mapsto \|f\|_p$ is continuous on $[1,p')$ Or maybe we need to impose some more constraints such as finite measure space. In case of finite measure space, I tried to use . |
There are only two entries, $0$ and $1$, over $\mathbb{Z}_2$. Thus, only $16$ possible $2\times 2$ matrices over $Z_2$, and $6$ of them have full rank: $\begin{pmatrix}0&1\\ 1&0\end{pmatrix} \quad \begin{pmatrix}1&1\\ > 1&0\end{pmatrix} \quad \begin{pmatrix}0&1\\ 1&0\end{pmatrix} \quad > \begin{pmatrix}0&1\\ 1&1\end{pmatrix} \quad \begin{pmatrix}1&1\\ > 0&1\end{pmatrix} \quad \begin{pmatrix}1&0\\ 0&1\end{pmatrix}$ Randomly generate a $n\times n$ matrix over $\mathbb {Z}_2$ (where n is big, say, $1000$). What's the probability that the matrix has full rank? I'd want to talk something regarding to this question. I found the probability is equal to: $\dfrac{(2^n-1)(2^n-2)(2^n-2^2)...(2^n-2^{n-1})}{2^n} \tag{1}$ On other hand, what's difference between $2^n$ and $2^{n^2}$? $\dfrac{(2^n-1)(2^n-2)(2^n-2^2)...(2^n-2^{n-1})}{2^{n^2}} \tag{2}$ Can you tell whether or not I'm wrong? Regards! | What is the probability that a random $\{0,1\}$, $n \times n$ matrix is invertible? Assume the 0 and 1 are each present in an entry with probability $\frac{1}{2}$. Is there an explicit formula as a function of $n$? Does it tend to 1 as $n$ grows large? I'm sure this is all known... Thanks! |
Recently Apple announced the Swift language to be open sourced later this year. I noticed that google prettifier, which is used in eg. stack overflow to post code snippets, is not yet been adapted with Swift language specification. I checked the GitHub project and it seems not present in the source sections. I posted an issue to ask for this extensions I don't know if any one out there already worked on a prettifier extension for Swift but I think it would be nice to have this new language integrated in the prettifier to post correctly coloured Swift snippets. Not only for stack overflow but also as use of personal sites, blogs,... Just got mail today on 04/08/2015 so this can't be duplicated anymore ;-) [code-prettify] Add Swift Support (#383) This pull request adds Swift to the list of languages that can be prettyprinted. It should be noted that it does not support highlighting the contents of string interpolation expressions, due to the high complexity of correctly classifying such structures with just a lexer. You can view, comment on, or merge this pull request online at: Commit Summary Add a file for the Swift language lexer definition. Add support for whitespace and comments Add highlighting for Swift keywords Add highlighting for string literals Add shortcut for string literal detection to Swift Add integer literal support for Swift Fixes and improvements for Swift Add floating point literal support for Swift. Add punctuation support for Swift Add punctuation support for Swift Merge branch 'master' of github.com:chrisrecher/code-prettify Add type support for Swift, to the fullest extent possible in a lexer Remove unnecessary comments File Changes A src/lang-swift.js (59) Patch Links: | 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? |
Lest they do anything before we. Lest they do anything before us. One of my students, for their creative writing coursework, phrased his sentence as shown in quote 1, but I have a confusion as to which (1 or 2) is more grammatically appropriate, and the literary device used in the first sentence, if any. | I have the following sentence: "The swimmer next to Cavic arrives just before he." My question is why can't we write "The swimmer next to Cavic arrives just before him"? Isn't "just before..." an prepositional phrase that modifies "arrives"? Thus, wouldn't what follows be the object of the preposition, and thus one would have to use the objective case "him"? I know that "he" is correct, but why is it correct, and why can we not use "him"? |
I thought the center of mass equation was derived for general forces, $$\sum{\vec{F_{ext}}}=M\vec{a_{CM}}$$ Then suddenly when the external force on the $i$ particle is of the form $m_ig_i$, where $g_i$ varies throughout the body, we have to use this equation: $$\vec{W}=M\vec{a_{CG}}$$ where $CG$ is a different point than $CM$. So, what makes gravity special? EDIT: I'm not asking the difference between them. They have different formulas, so obviously they have different values when $g$ is not constant. I'm asking why doesn't the resultant gravitational force or $W$ can't be thought of as acting on the center of mass when the center of mass equation is derived for any general external force. | My book says: For most of the small objects, both are same. But for mammoth ones, they are really different ones. And in a gravity-less environment, COG is absent; COM still exists. Ok, what's the big deal when things are small and big? How these two : & ? |
I have Ubuntu 16.04 installed. I have an Intel G33/G31 Express Chip in my Foxconn desktop computer. The Ubuntu does not detect my analogic monitor Samsung SB19B300B. This monitor has 1366 x 768 max resolution. In the System setting Display, Ubuntu only shows me the options 1024 x 768 (4:3) and 800 x 600 (4:3) for resolution and shows me "Unknown display" but DOES NOT show me 16:9 relations for 1366 x 768 resolution (60 Hz). When I run the recommendations of "How to set a custom resolution?" I obtain this results: root@tomas-OEM:/home/tomas# cvt 1366 768 60 # 1368x768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz Modeline "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync root@tomas-OEM:/home/tomas# xrandr --newmode "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync root@tomas-OEM:/home/tomas# xrandr --addmode VGA-0 1368x768_60.00 xrandr: cannot find output "VGA-0" root@tomas-OEM:/home/tomas# xrandr | grep -e " connected [^(]" | sed -e "s/\([A-Z0-9]\+\) connected.*/\1/" VGA1 root@tomas-OEM:/home/tomas# xrandr -s 1368x768 Size 1368x768 not found in available modes Use as a temporary solution while finding a better way: I create a script with the commands: xrandr --newmode "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync + vsync xrandr --addmode VGA1 1368x768_60.00 xrandr -s 1368x768 I set it as executable and I add it to the "applications at startup" But I do not think it's good because the start takes more time and works like OS windows performance! | I tried to use xrandr to set 1680x1050 as a new mode to VGA output, but it says: sudo xrandr --addmode VGA-0 1680 X Error of failed request: BadMatch (invalid parameter attributes) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 18 (RRAddOutputMode) Serial number of failed request: 35 Current serial number in output stream: 36 |
Let's $v$ the smallest positive integer > 1 for which $2 ^ {v} - 1$ divisible by $p$. Prove that $2 ^ {m} - 1$ ($m > v$) divisible by $p$ then and only then $v$ divide $m$? There is a hint that enough to divide $m$ into $v$ with the remainder, but it gives me nothing. | I figured we'd have to show $a=qb$ from $2^a-1=r(2^b-1)$ for $q,r\in\mathbb{Z}$ for the first implication and vice versa, how should I proceed from here? |
I know that (I was also ), but, what if the question is really trivial, so trivial it can be found in the manual? Shall I delete it? I would delete it right away but I've heard that by deleting questions you might get penalized. But in no one has invested an effort in my question and probably never will... EDIT: thank you for all your responses, they encouraged me to keep the question there. You are absolutely right it allmost surely will be useful to someone - because many people, as well as myself, when they have problem they start by typing it into google, instead of studying the docs. I've been sometimes downvoted for stating this approach but thats just how are fast society works. Google is faster than searching any docs, especially in combo with Stackoverflow... | Meta appears to have come to a consensus that when a user asks a question that is easily answered with Google that we should not close the question but rather answer it properly. However, what does this mean about asking questions that can be answered easily with a Google search? More specifically, should we encourage or discourage such behavior, and how? Here are some reasons that I can think of for each option. Reasons to Encourage "" And that includes answers easily accessible via Google search Sometimes we want to another answer to a that Sometimes we want to save others the Google searching we did by asking and answering the question ourselves. In this case, we did do the research, but the question by necessity must not show research effort. Reasons to Discourage Question quality may drop, as users will feel less incentive to Google their problem. This will also probably result in a greater quantity of questions as well that have already been answered on StackOverflow, as Google searches often result in StackOverflow answers. |
In order to minimize mouse usage (accessibility and health reasons), how can I pipe the standard out to the OS clip board? That is, I'd like to do something like: $ drush uli | copy-this-to-clipbaord $ drush uli > copy-this-to-clipbaord Possible? | In Windows I used command-line clipboard copy-and-paste utilities... pclip.exe and gclip.exe These were UnixUtils ports for Windows (but they only handled plain text). There were a couple of other native Windows utilities which could write/extract any format. I've looked for something similar in Synaptic Package Manager, but I can't find anything. Is there something there, that I've missed? ... or maybe this is available in Bash scripting? The type of utility I'd like will be able to read/write via std-in/std-out or file-in/file-out, and handle Unicode, Rich Text Format, picture, etc. clipboard formats... NB: I'm not after a clipboard manager. |
When installing Linux, everything went fine until I restarted to go back to windows. GNU GRUB came up and didn’t let me boot to windows. I tried resetting the computer and going to the bios to change boot order. But when I do that everything is locked up and I can’t change anything in it. The only way to get to windows is by going through Linux bootloader first. How do I remove Linux, GRUB and everything from that so I can boot to windows and access my BIOS again. MOBO: ASUS Z73e (I think) | I have had the last Ubuntu distro (10.something) installed for a year and love it. But I have run in to an issue when I tried to upgrade it to the latest one it did not work and there has come some serious issues now with almost everything and I want to remove Ubuntu completely and install the new one. How can I remove the operating system (I don’t mind formatting the whole thing if that’s what’s needed). |
Im new to python and got stuck while processing a .bat file 1) I have a .bat file that contains the following lines: set local_dir=%~d0%~p0 set LVMain_StartAddress=0xfaff set LVMain_EndAddress=0x0f4ff set HVMain_StartAddress=0x01d00 set HVMain_EndAddress=0x095ff set LVMain_StartAddressMerged=0x0D000 set LVMain_EndAddressMerged=0x0fcff set HVMain_StartAddressMerged=0x01001d00 set HVMain_EndAddressMerged=0x010095dd 2) A python script runs through the file to look for the line "set LVMain_StartAddress=0xfaff" 3) When it finds the line, I want to replace the hex address with a new one. Sometimes the new hex address is 5 characters long 4) Below is the python code I wrote to do this: # write LVMain start address in .bat file with open("..\..\..\Tools\Scripts\GenerateRomTestChecksums.bat", "r+") as f: #read lines individually until we find where to write LvMain Start address BatFileLine = f.readline() while( (LVMain_StartPattern in BatFileLine ) == False ): BatFileLine = f.readline() #set marker back to the beginning of the line LineMarker = int(f.tell()) - (int(len(BatFileLine)) + 0x01) f.seek(LineMarker) #split string where address starts to write new address in file name, hex_address = BatFileLine.split('0x') #append new address and carriage return name = name + APPL_End_address + "\n" print(len(name)) contents = f.read(len(BatFileLine)).replace(BatFileLine,name) f.seek(LineMarker) f.write(name) This is part of a larger function and "APPL_End_address" is given as a parameter 5) When I run this code, and the new hex address is 5 hex digits wide, I get the following output: It seems the new hex address is written correctly, but the first character of the next line erased. Any ideas why? | I want to loop over the contents of a text file and do a search and replace on some lines and write the result back to the file. I could first load the whole file in memory and then write it back, but that probably is not the best way to do it. What is the best way to do this, within the following code? f = open(file) for line in f: if line.contains('foo'): newline = line.replace('foo', 'bar') # how to write this newline back to the file |
I just downloaded blender and it says at the top that I am in blender render. I want to make it on cycles render. How can change this? | I'm new to blender. How do you change the render engine? According to this video, the button should be along the top. I've searched google, and the blender documentation with no luck. |
When loading data from my postgres-db (where I can only read from, so not my own db) the field with the point-coordinates like .. 'POINT(390002.1610814564 6001433.406049595)' .. are getting (auto)converted into .. 0101000020E964000022936245FEDA1741A4A29D5E0DE85641 Working with coordinate-systems is rather new to me, so can anyone tell me how this converted coordinate is called or how I can convert it back into the previous format? Don't know if this information is helpful, but I'm using django (python) with the following code: try: with connections['db_second'].cursor() as cursor: cursor.execute("SELECT * from ...") row = cursor.fetchall() except Exception as e: cursor.close() | How can I convert WKB to WKT form? I stored coordinates in WKB but now I want to display it using WKT form. |
I don't quite understand what was the point of closing The question was able to get an answer with 4 up-votes! It was favorited and up-voted. It could bring profit to the community. So I don't see why other people intrusively jump in and say "this is off topic." Who should define what is off topic? I think the people interested in that particular question and answer should! EDIT: The question is about HW, but that's closely related to SW. The reply clearly shows it's not offtopic as it speaks a lot about software and packages - and that's already a good fit for Stack Overflow! EDIT: The answer there has been particularly useful. Don't tell me that this doesn't belong to SO, when SO is site for programmers! "... R appears to be able to use the GPU, see the gputools package and for an introduction. You would probably need to make sure that this works on whatever system you plan to install R on (which needs special attention if you are running on Linux). NVidia tend to be the best choice, as they are supported with Linux drivers (although they tend to propietary)...." | I frequently come across a really useful answer on StackOverflow which has been closed because it doesn't match the Q&A format. Examples include , , , and there are others. Where should this information be exchanged if it's not on stackoverflow? It seems the moderators are often somewhat overzealous... ---edit When I say best, I mean they are informative and useful for someone who's looking for an answer to them. Even if they do become a bit of a discussion, I value other people's opinions on the relative merits of the different JPA frameworks. I come here looking to choose one and the answer helps me. So what if it's not a definitive answer? ---edit I don't care how popular a question is, nor how interesting it is. Users are interested in stuff that's useful to them. Plenty of those were useful (as judged by the upvotes on the answers: 'This answer is useful'), but closed because they didn't have a definitive answer, as far as I can tell. ---edit Seems I'm not the first person to think this: there are various similar questions to mine like this one: In it the user lists lots of other useful questions which have been closed: So isn't there a place on stackoverflow for these questions? A discussion section, maybe? |
typedef enum enumStruc_2 { ENUM_5 = 0xFFFFFFF0, ENUM_6, ENUM_7, ENUM_8 } enumStruc_2; Here, size of enum is 4 bytes(Integer size). How it saves all of its enum member values within 4 bytes? Is always enum size 4 bytes irrespective of value of its member? | I'm creating a set of enum values, but I need each enum value to be 64 bits wide. If I recall correctly, an enum is generally the same size as an int; but I thought I read somewhere that (at least in GCC) the compiler can make the enum any width they need to be to hold their values. So, is it possible to have an enum that is 64 bits wide? |
We have a current setup where we have two SQL 2008R2 database servers in production. Our reporting team requested a single place they could query data from both servers (to avoid both hitting production directly and the performance issues with linked servers). So we set up log shipping where we ship several databases from both sources to a target server. It works great, the databases on the target server are read only during the day and only unavailable when the log shipping restores are scheduled at night. However, the vendor applications for both source servers are going through an upgrade project, and they will unfortunately have to be be different versions (SQL 2014 and 2016 respectively). Most of what I have researched seems to say that you cannot log ship from a different source version, but I've also found information suggesting that you can ship from a lower to a higher version, but am unable to find anything official. So, my question is, is it possible to log ship from both 2016 and 2014 sources into a 2016 destination, AND leave the databases read only when they are not restoring? And is there official Microsoft confirmation of this? | I'm lead to believe that TLS is only appropriate/supported across the same versions of SQL Server. What I'm trying to do is to maintain a reporting (read only) version of a production transactional SQL Server 2005 database (180 Gb) on on a SQL Server 2012 server (and in the case of other clients 2008 R2). I can do simple back up and restore at any time but to improve latency between refreshes of the database, I'd like to see if I can do something like transaction log shipping. If TLS is not available in this scenario what do the panel suggest as an alternative strategy. |
I have a Windows 10 laptop (Lenovo Z570) and I decided to give Ubuntu a try and install it alongside Windows. So I shrank my D: partition using Windows disk management utility, downloaded the Ubuntu ISO image and booted it from USB. During the setup I chose the Something else option (Note: Ubuntu didn't detect Windows and didn't offer me the option to install it alongside Windows so I chose the Something else option) and made 3 partitions for root, swap and home. When I proceeded with the installation process, an error appeared saying The 'grub-efi-amd64-signed package failed to install into an target. without the GRUB boot loader, the installed system will not boot. So I ran the setup again and this time I chose to overwrite the existing Ubuntu installation that wasn't completed and this time the setup succeeded. But when I restarted my laptop, I found out my laptop booted directly into Ubuntu instead of showing me the bootloader. Just when I turn on my laptop and before Ubuntu logo appears, I encounter this error (this error got fixed but GRUB still can't detect Windows 10) System BootOrder not found. Initializing defaults. Things I have tried: Running sudo update-grub and restarting Running boot-repair and restarting and repeating that again (Here's the pastebin for the first time: and the second: Changing the boot order to give Ubuntu the priority Mounting the Windows partition, then running sudo os-prober then sudo update-grub Opening GRUB manually by pressing Esc in BIOS, but i just see Ubuntu listed and Windows isn't there One thing I noticed when changing the boot order is that there were two values called ubuntu not one. Maybe this has to do with the first failed setup I did and then when I did a second setup so maybe it got a little messed up? (This also got fixed and instead it's a single value) | I have installed Ubuntu 15.10 alongside Windows 10 with UEFI. To install Ubuntu, I chose the option install alongside Windows 10 or something similar to this. Then I created a new partition for Ubuntu and installed it. After installation, the boot menu did not show up. Initially I thought Ubuntu has not been installed, but when I plugged in the USB drive and wanted to install Ubuntu I saw an option of reinstalling Ubuntu on my machine. So, I found out that Ubuntu is installed. Pressing F8 and F12 also does not help. Can anyone help me bring up the GRUB boot menu? In Windows, I also entered the command bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi in cmd, but still the boot menu does not show up. Reply (Himanshu) : Just boot in bios and, if you can, add boot option with name say ubuntu and path EFI/ubuntu/shimx64.efi. No need for live PCB or anything. Move the boot option to top. This is for dell GUI bios but I assume it works for all. Or you may want to see or , where you can enable Windows Boot Loader for one boot or forever as you wish, and boot Ubuntu from it. If you want now, you can use the installed Ubuntu terminal to use the commands update-grub to use GRUB instead. (Not enough reputation to answer properly btw.) |
I need something like proof environment from amsthm, but with word "důkaz" (proof in my language) at start of environment. How can I define such environment? Thanks for help. | I want to change the word "Proof" into "Solution". Of course the following works. \begin{proof}[Solution] \end{proof} But it's quite cumbersome to add this additional [Solution] every time. Is there a way to make it automatic? Edit: I'm using amsthm. \documentclass{amsbook} \usepackage{amsthm} \begin{document} \begin{proof}[Solution] This is a solution. \end{proof} \end{document} |
I'm using aptitude as package manager. If one marks packages for removal it calculates the changing in disk usage, i.e. how much space is freed by removing that package and its automatically installed, otherwise unused dependencies. Is there a way (not necessarily within aptitude) to get this number for, say, all packages marked manually installed? | given a package name, I want to find how much space would be freed up if the package, and its dependencies, were deleted. As dependencies might be shared between packages, maybe the right way to put it is: How much space does a package take, including all dependencies that are only beeing used by this package I would prefer CLI solutions, because I would use them in scripts |
For example, lets say there is a hosting company, hostingcompany.com, with nameserver ns1.hostingcompany.com. When I type hostingcompany.com into my browser, my computer contacts a top level .com domain nameserver, which in turn contacts the name server for hostingcompany.com to get the A record for hostingcompany.com or any of its subdomains. Isn't this circular, since the FQDN for the nameserver is a subdomain of the domain name itself? In other words, in order to find the IP address of ns1.hostingcompany.com, we need a nameserver for *.hostingcompany.com, which is itself? What am I missing? | This is a about DNS (Domain Name Service). If my understanding of the DNS system is correct, the .com registry holds a table that maps domains (www.example.com) to DNS servers. What is the advantage? Why not map directly to an IP address? If the only record that needs to change when I am configuring a DNS server to point to a different IP address, is located at the DNS server, why isn't the process instant? If the only reason for the delay are DNS caches, is it possible to bypass them, so I can see what is happening in real time? |
We need to implement custom software analytics to trace the usage of the application. We have a common Command base class so the idea if to trace there something that allows us to know which command has been executed. Consider the following sample code on a WPF Window with 1 Button: public partial class MainWindow : Window { private readonly Command _commandName = new Command(); public MainWindow() { InitializeComponent(); } private void Button_Click(object sender, RoutedEventArgs e) { _commandName.Execute(); } } public class Command { public void Execute() { MessageBox.Show(this.GetCommandName()); // .... } private string GetCommandName() { string commandName = null; MethodBase method = new StackTrace(new StackFrame(2)).GetFrame(0).GetMethod(); Type callingType = method.DeclaringType; if (callingType != null) { IList<FieldInfo> variables = callingType.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.GetField | BindingFlags.Instance).Where(f => f.FieldType == typeof(Command)).ToList(); if (variables.Count == 1) { commandName = variables[0].Name; } } return commandName; } } This code will show the variable name but only if there is one Command variable on the calling type. Is there a way of getting the calling variable name directly without going thru reflection? The output of this code is (and should be) _commandName not Button_Click. | When logging in C#, how can I learn the name of the method that called the current method? I know all about System.Reflection.MethodBase.GetCurrentMethod(), but I want to go one step beneath this in the stack trace. I've considered parsing the stack trace, but I am hoping to find a cleaner more explicit way, something like Assembly.GetCallingAssembly() but for methods. |
If $\gcd(n,a)=1$, and $\gcd(n,b)=1$, prove $\gcd(n,ab)=1$ | If $\gcd(a,n) = 1$ and $\gcd(b,n) = 1$, then $\gcd(ab,n) = 1$. Also... $a,b$ and $n$ are natural numbers. I feel I should begin with EEA to multiply out the gcd's, but I don't know where to go from there... |
I am creating a drain that lets water in but keeps pieces of plastic out. I need to know the size of a standard water droplet. | Assume I have a inverse cone which holds 200ml water. I am going to cut the tip of the cone to create a small hole. How to calculate the maximum radius of the hole that the water will still stay in the container? |
I bumped recently (twice) at following problem - is it possible to find on classpath specific implementation of generic interface? To visualize this please consider these snippets of code: public interface Cleaner<T extends Room> {} public class KitchenCleaner implements Cleaner<Kitchen> {} public class BathroomCleaner implements Cleaner<Bathroom> {} Now - Is it possible to have a following method ?: public static <T extends Room> findCleanerServiceForRoomType(T room) { return ??? } returning KitchenCleaner for Kitchen class and BathroomCleaner for Bathroom class? Of course I would like to have it extensible so that when new Room and Service type is added this method still works... So no switches or ifs :) | Can I do it with reflection or something like that? |
Goal Using the latest LTS server iso (alternate), which at the time of writing is ubuntu-18.04.1-server-amd64.iso, I want to be able to do an installation, using a preseed and a kickstart file hosted on a webserver, however I cannot use DHCP. So I am looking for a way to manually set the IP address when booting up the installer. Steps previously taken I have tried using . I've tried the various forms of it, leaving out some fields and other times leaving them empty – the options are detected during boot-up (see below screenshot), but they do not seem to come into affect. I've also both tried adding it before and after the two dashes. I have tried this with the 16.04 server iso as well. Note It is not possible for me to use TFTF, PXE or anything like that. Also, I do not want to have to make custom installers, I want to be able to use the iso from the mirror. Final remarks If this is simply no longer possible, could someone please refer me to where this change was documented? I can not find any information indicating so. | I would like to customize Ubuntu live CD by installing some additional packages. I have followed but it doesn't seems to work. Can anyone provide clear instructions? Note: I do not prefer Remastersys, manual way will be appreciated. Customization Packages that I want to install: Thunderbird Samba SSH Changes that I need: Remove Games menu from the Application menu Firefox shortcut on Desktop Radiance as the default Theme Different default Ubuntu Wallpaper Configuration file changes I want the panel to be placed at the bottom I want to paste my Samba configuration file instead of default Samba configuration I have few Firefox shortcuts and folders I would like to show that in Desktop Also it will be nice if you say me how to change the icon sets Recent Updates I have customized Ubuntu 10.10 with Firefox shortcuts and few folders on desktops. Everything went smooth. But the installer gets crashes after choosing the timezone. How do i fix this issue? Also setting wallpaper affects the login screen. The wallpaper which i set is displayed on the login screen also. I just want the default one for the login screen. |
I want to replace create_test in the file with #create_test if the next line contains psfxxx_16_pi. How can I do it with sed for the whole file containing this? Input file content: create_test -type hard -outer { 1.0000 } { \ psfxxx_16_pi/psfop/deadline_north_re_0 } create_test -type hard -outer { 0.0000 } { \ psfxxx_16_pi/psfop/deadline_south_re_1 } Output file: #create_test -type hard -outer { 1.0000 } { \ psfxxx_16_pi/psfop/deadline_north_re_0 } #create_test -type hard -outer { 0.0000 } { \ psfxxx_16_pi/psfop/deadline_south_re_1 } | I have one file like: ID_SOUR_CALENDAR BIGINT NOT NULL DEFAULT 0 COMPRESS 0 , UNIQUE PRIMARY INDEX ( CALENDAR_DATE ); ID , ID_SOUR , PRIMARY INDEX ( CALENDAR_DATE ); I want to replace the ',' by ')' in the line just before the line containing PRIMARY. The result should be: ID_SOUR_CALENDAR BIGINT NOT NULL DEFAULT 0 COMPRESS 0 ) UNIQUE PRIMARY INDEX ( CALENDAR_DATE ); ID , ID_SOUR ) PRIMARY INDEX ( CALENDAR_DATE ); |
Preamble: I know that 'give a reason when downvoting' is a very common request, and I assure you that I have read these posts and the discussions in them and my request is very different. This isn't about encouraging people to comment and is more about gathering metrics. I'd like to see a feature whereby people who are downvoted get some better feedback on why they were downvoted, especially given that people rarely leave comments in practice. So my suggestion is that when user clicks on the downvote, they are prompted to pick from a short list (No more than 5) of common reasons. It would be a popup that replaces the existing "Please consider adding a comment" box. The user receiving the downvote would see how many people downvoted them for each reason, but not who did it. It would significantly address the issue of people being too lazy to comment or not wanting to comment (for fear of retaliation or any other reason) while helping to ensure the user gets useful feedback. Perhaps the downvote could also be weighted based on whether or not a reason is picked. For questions the list might look something like: Not a question Not relevant to the subject area Trivial question with no research effort Poorly asked question Other And for answers, this might be: Nonconstructive or not an answer Incorrect or dangerous answer Poor explanation Doesn't answer the original question Other | Note: If you're looking for a simple explanation as to why comments aren't required on downvotes, see . I used to get "upset" (though that is too strong a term) when I got downvoted without comment. If my answer isn't good enough then I'd like to know why. Not only does it improve the answer for the OP but it improves my knowledge too. Where the down-vote has been explained I've found it useful & it has improved my answer, or forced me to delete the answer if it was totally wrong. So is there any way we can encourage people to leave a comment? Perhaps they don't lose rep if they explain their down-vote? I must admit though that I haven't always explained my down-vote either so you could call me a hypocrite. I've also grown a thicker skin over the months of using SO (it seems to have come with the higher rep score ;-)), so I'm less bothered about this now. |
I have read in Zeemansky's physics $dQ=dU+pdV$ for first law of thermodynamics But when I came across another book of thermal physics,it says $δQ= dU +pdV$. So what us the difference ? | I have read the thread regarding , but it does not answer my question. I am confused about the notation for change in Physics. In Mathematics, $\delta$ and $\Delta$ essentially refer to the same thing, i.e., change. This means that $\Delta x = x_1 - x_2 = \delta x$. The difference between $\delta$ and $d$ is also clear and distinct in differential calculus. We know that $\frac{dy}{dx}$ is always an operator and not a fraction, whereas $\frac{\delta y}{\delta x}$ is an infinitesimal change. In Physics, however, the distinction is not as clear. Can anyone offer a clearer picture? |
How to prove that "If $X$ is a Hausdorff space equivalent to $\varDelta \left(x\right),$ it is a closed set in $X\times X$"？ | Let $X$ be a topological space. The diagonal of $X \times X$ is the subset $$D = \{(x,x)\in X\times X\mid x \in X\}.$$ Show that $X$ is Hausdorff if and only if $D$ is closed in $X \times X$. First, I tried to show that $X \times X \setminus D$ is open using the fact that $X \times X$ is Hausdorff (because $X$ is Hausdorff), but I couldn't find an open set that contains a point outside $D$ and is disjoint to it... |
I've been trying to learn Unity and pretty soon in the tutorials I've found this: private Rigidbody rb; void Start () { rb = GetComponent<Rigidbody>(); } I'm not knowledgeable with C# syntax so what I really would like to understand is this function<object>() syntax. Thx | I thought I'd offer this softball to whomever would like to hit it out of the park. What are generics, what are the advantages of generics, why, where, how should I use them? Please keep it fairly basic. Thanks. |
I uploaded a local text file omitting the remote location and can't find the file (Ubuntu 16.04). rsync -chavzP dump.sql user@ip-address It's not in my home directory or anywhere else that I can tell: find / -name dump.sql -print I can re-upload with a remote location, but would like to at least find and remove that 6GB dump that I'm not using. | I accidentally rsynced .thunderbird to user@host instead of to user@host:/home/user. Where is .thunderbird now? Is there a good way to search for the folder? |
So, in the books we see the spell accio being used a few times to bring forth a desired object to the caster. However, we also see that to get the desired effect, one doesn't have to be too accurate in their description of the object (Harry says accio firebolt and his broom alone comes to him), and yet sometimes they get a range of objects that fit the description (Hermione calls for books about Horcruxes, and many of them come to her). So I think that begs two questions. What is the range of Accio? Could I call for something that was on the other side of the country? What about the other side of Hogwarts? How accurate is it? If I said "Accio Notebook" would it bring me my own notebook, or all the notebooks in the room? | We know that Accio spell (aka ) has some limits: It can be blocked (e.g. Harry couldn't Accio the Diadem in RoR in Deathly Hallows). Many more failures are listed on Wikia. But what are the exact full rules and limitations governing the spell in Harry Potter world? Distance? Line-of-sight? Knowing exact or approximate location? Specificity of item (e.g. "Accio Broom" seemed to work for Weasleys in OotP to bring their locked-up brooms - why not just a random broom?) Types of Accio-able stuff? Can you Accio water? Lump of earth? Gases/liquids/etc...? Can you Accio based on jQuery selector (or an SQL where clause), for lack of a better description? E.g. "Accio the book that has the word 'Flammel'"? "Accio biggest green ball from this room"? Can you Accio ALL items of a kind? (the reason I thought of this whole question was seeing "Accio all guns" comment in ). Can you Accio vague stuff? ("Accio meal"). Other rules that can be inferred. NOTE: While Wikia article has some of the info, it is clearly very lacking in details on specific rules based on specific instances in canon. I'm looking for a fully comprehensive, organized ruleset for the charm, not merely 1-2 tidbits in Wikia article. |
This is what happens. I don't understand why. Could anyone help me please? | I used Blender cycles to render an image, but the output has a watermark with some words in the top left hand corner. How can I make it disappear by changing the related setting? |
Is there any grammatical correctness in either of these expressions: "I only have 10 dollar on and "I have only 10 dollar on me" ? | Which is grammatically correct? I can only do so much in this time. or I can do only so much in this time. |
This was one of my first clients. I want to use the work I've done to market myself as a designer & marketer but I'm afraid of legal backlash for using company information. Here's the catch, although I was working "for hire" - there is No legally binding contract (I was sending contracts at the beginning & it became a he said she said with him promising me a bunch of things he didn't follow through with. There's maybe 3 files that he legally owns. All the rest he didn't want contracts for.) I filed taxes as a 1099 independent I provided all of my own equipment and tools (computer, apps, & drive) They didn't provide me with benefits (health) and only provided a workspace. I ended up ceasing work with them because I was being exploited (less than 10k within a year) for all the work I was doing. With all that being said, I know I technically own copyrights since I had spoke briefly with a copyright attorney about it asking for some legal advice. I also looked into laws and work for hire regulations so I'd say I'm in the clear. But now I'm concerned about using the work for my portfolio and marketing myself as the sole designer that practically carried the company. What do I do? Should I remove the logo & company information? Does it matter? | Let's say Designer X worked full time for Company Y. While there, Designer X built an illustration to explain how Company Y's product works. Then, some years later after Designer X left Company Y, a third party requests permission to use said illustration in some educational material it plans to publish, and wishes to cite the author. Who does the third party cite, Designer X or Company Y? |
So I found this bug crawling around near my kitchen sink. There were two others, but not any sort of swarm. I think they're some sort of insect larva, as they don't have a bunch of legs like a millipede or woodlouse, but I have no idea what kind. There also seem to be several shed shells nearby, if that helps. As for location this is in the upper Midwest. Here's the top of the thing, with screwdriver for scale And here's the underside. | What kind of insect can this be? This appears to be just a shell after an insect went through a metamorphosis process. |
Not sure if the picture is visible - if not please ignore posting! These are the capacitors I want to replace but I don't know what type they are. | I'm replacing the capacitors in a very old tape recorder (1957) and I'm ok with the electrolytics but there are 4 with values 0.001 (x2), 0.002 and 0.005 uF i.e. 1, 2 and 5 nF. Two are marked as 250v and two as 750v. Can anyone suggest what to replace them with please? |
Prove that for all $n$, $121\mid n^2+3n+5$. I thought proving $n^2 +3n+5\pmod{121}\equiv 0$ had no solutions would be a good start, so I completed the square of $n^2+3n+5($, and arrived at $(n+62)^2 \pmod{121} \equiv 3718$. Replacing $n+62$ by $x$, I lastly arrived at $x^2 \equiv 88\pmod{121}$. Now, Im stuck. Any hints would be appreciated. | Question: Show that $n^2 + 3n + 5$ is not divisible by $121$, where $n$ is an integer. |
Usually when on Earth we can use as an approximation: g = a = 9.18 $\frac{m}{s^2}$ s = vi + 1/2 a$t^{2}$ However, how would I determine the distance traveled in situations where the the acceleration due to gravity is changing non-negligibly because the distances are so large? I know that the following equation has to be used somehow: a = $Gmr^{-2}$ I am not sure exactly how though. For example, if given the information that an object is at a certain distance and is being attracted by a larger object of a given mass, the method should calculate where the object will be at a given time. | I thought this would be a simple question, but I'm having trouble figuring it out. Not a homework assignment btw. I am a physics student and am just genuinely interested in physics problems involving math, which would be all of them. So lets say we drop an object from a height, $R+r$, it falls toward earth. This height, $R+r$, is far enough away that the $g$ it experiences is a fraction of $g$ at sea-level. Let's just say that air resistance is negligible, and it wouldn't be that complicated to just integrate from $0$ velocity to the terminal velocity piece wise and deal with the rest of it later. So the key here is that acceleration is changing with time. I thought I could simplify this by saying it changes with distance, and it has nothing to do with time, but this didn't really help, my guess is that maybe time is important (doh). I tried integrating acceleration with time, and ended up nowhere. I tried integrating $a=GM/R^2$ with respect to $R$ from $R+r$ to $R$ and ended up with a negative function. I saw somewhere someone tried to expand with taylor series, they even have something similar on hyperphysics, but I can't figure out how to obtain the polynomials that precede the variables. This is the hyperphysics site where they use polynomials to find the distance. Maybe I can't solve this because I haven't taken a course in differential equations yet. What I want to know is how to calculate the distance at any time. |
I'm new in Category Theory and I just learned about epis and monos. I've been doing some exercises so far, but one of them is confusing me: Let $i:\mathbb Z \to \mathbb Q$ be the inclusion of integers to rationals (equipped with the usual ring structure): Show that $i$ an epimorphism Show that it is not surjective I tried to assume $g,h: \mathbb{Q} \to R$ and that $g \circ i = h \circ i$. But now I have no idea how to get $g=h$. It is clear for me that it has something to do with the fact $i$ is an inclusion, but I just can't construct any argument. I attempted proof by contrapositive as well, assuming $g\neq h$, but the difficulty persists. Thanks in advance! | I have two ring homomorphisms $f,g\colon \mathbb{Q}\to X$. I know that $f=g$ on the integers. How can I show that $f$ and $g$ agree on the rationals? My attempt: let $x,y \in \mathbb{Z}$, $y\neq 0$. $$\begin{align*} f(x/y)&=f(x)f(1/y) &&\text{because }f\text{ is a ring homomorphism}\\ &=g(x)f(1/y) &&\text{because }f\text{ and }g\text{ agree on the integers} \end{align*}$$ I do not know how to rewrite $f(1/y)$ so that I can replace it with $g(1/y)$. Any hints will be much appreciated. Thanks. |
Its a question I have read in a book, that, When two surfaces are polished, the frictional coefficient decreases. But if the surfaces are made highly smooth, the frictional coefficient increases and becomes very large. Explain why? My thinking says that with excessive smoothness there is more ease of bond formation between the two surfaces and since friction (modern theory) is because of temporary bond formation, friction increases and hence its coefficient. Is this thinking right? | I read that: If you take a rough surface and make it smooth, the coefficient of friction decreases. But if you make it super smooth, then the coefficient of friction increases. How come? |
Here's my situation: I have one hdd with Ubuntu on it (Drive 1) and and one that is empty/formatted (Drive 2.) What I want to be able to do is install Windows 10 on Drive 2 from using something like gparted, KDE Partition Manager, etc. How would I do so? Everything else I have tried isn't working (Win10 install tool, iso, bootable usb, DVD, etc.). It would be nice if I didn't have to install anything extra. | 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! |
So lately I was speculating why nature choose the number 2 in Coulomb's law like why not 2.$10^{100}$ trailing zeros and then 1 or anything else. I find 2 a bit arbitrary the given explanation being the cancellation of 2 while applying Gauss law in 3d space. So my question is, is there any fundamental explanation for this fact like from QED or something like that? | Coulomb's Law states that the fall-off of the strength of the electrostatic force is inversely proportional to the distance squared of the charges. Gauss's law implies that the total flux through a surface completely enclosing a charge is proportional to the total amount of charge. If we imagine a two-dimensional world of people who knew Gauss's law, they would imagine a surface completely enclosing a charge as a flat circle around the charge. Integrating the flux, they would find that the electrostatic force should be inversely proportional to the distance of the charges, if Gauss's law were true in a two-dimensional world. However, if they observed a $\frac{1}{r^2}$ fall-off, this implies a two-dimensional world is not all there is. Is this argument correct? Does the $\frac{1}{r^2}$ fall-off imply that there are only three spatial dimensions we live in? I want to make sure this is right before I tell this to my friends and they laugh at me. |
In the android app (1.0.58) I have been running into questions where there is no text in the question and or answers. On some questions it is just the answers where nothing is shown on other questions it is both the question and the answer. When the text does not show I can still see comments that have been posted to the question and answers. I have not been able to determine a pattern about which questions this happens to but the latest example would be which I was not able to see the text for the question or answer. I am using a Galaxy S3 with android 4.4.2 and the app is 1.0.58 I am unable to provide a screen shot for this problem Also I don't feel this should be a duplicate of as that is not only from a earlier version of the app (posted almost a year ago), has no answer or solution and also appears to have no developer response at all. | Note: the bug has returned in version 1.0.89 in a somewhat different form. See: This possible bug report is similar to the bug in that was deemed not-reproducible. I can reproduce something similar with more recent app & Android versions. App Version: 1.0.34 (original report; is still present in 1.0.38, 1.0.42, 1.0.58) Android Version: 4.4 (up to 4.4.4) Device: Motorola Droid Maxx In the examples below, you can see some blank answer bodies. These are on different sites, and represent answers with both edited and non-edited text. In the first example, I clicked on the top answer tab to get to the answers, and in the second example I clicked on the bottom "View n Answers" button. (Trying to be a good little tester!) Because I've seen this blank-answer-body intermittently over the past couple weeks (before the May 7 update), my process to test was just to go to the first site I frequent and then systematically click through the question list until I found a question with answers in which at least one answer was blank. For all three sites shown below, it was within the first 5 or 7 questions sorted by newest. Please note that I have seen many questions with several answers, none of which were blank. It is truly intermittent. Example blank answer body at Workplace.SE: Example blank answer body at Programmers.SE: Example blank answer body at UX.SE: And now here's the kicker, which makes me think this is some sort of content-loading latency issue rather than a rendering issue: I returned to the left-side menu, selected the User Experience site, picked the same question as above, and then clicked the top answer tab to view answers again, and lo and behold the text is there: I then went back to the other questions with blank answers, shown above, and the answer bodies were no longer blank. I am happy to go through more tests/paths and do screenshots if it is helpful. The same bug also appears in question bodies. |
I am newbie trying to get a good picture of my friends (contrasting skin color) with snow covered mountain in the background. I tried using aperture priority mode with f/11 and 1/100 sec, 28 mm. People in the picture looked okay, but the background appeared too whitish or the background looked okay but people turned out too dark. After that I came across metering modes online, and I'm wondering which one I should use (spot metering appeared correct). Shot is taken 8 steps away from the people with Canon 60D. What all things should I consider to get a decent picture in this scenario? What mode? TC/AV/Manual. What metering mode? What settings? | I took a picture once in a beautiful location with an awesome background, and a cool location to get the shot. The problem is, the location of the subject had substantially less light then the background, giving a silhouette effect. Without using an external flash, and on a low budget, what could I do to improve this picture? Specifically, I shooting with a DSLR, outdoors. The DSLR has a small pop-up flash. The nearest good light source was maybe 5-10 feet away. Thanks guys! How do I avoid a dark subject when there's bright sunlight from windows? by I recently shot some photos at a friend's wedding. The location was lovely with lots of light — sometimes too much. The sunlight from the windows and skylights seemed to overpower the shot and the subject/people were very dark. What are some ways to avoid this without using fancy equipment? (I'm just starting out, I'm not a wedding photographer or anything!) Here is one example I took — and this is after I've lightened it somewhat with Picasa: I'm using a Nikon D5000 with a standard 18-55mm lens. |
When talking about past experience, what is the difference between these two sentences? Have you gone to Hong Kong? Have you ever gone to Hong Kong? | Both are in the present perfect, but one uses the verb 'to go' and the other 'to be'. Is there a rule for this? Is there any chance that the differences between "I have been" vs. "I have gone", are differences in English dialect (I don't know if this is the right word). Edit Could I say that North American English speakers use "I have gone", and maybe U.K speakers say "I've been"? Or vice versa. |
I'm getting a budget laptop, and I want to make sure it would run ubuntu 20.4 fine. I know the minimum requirement is 2gh dual-core, but I never had experience with this processor before. here are more specs of the laptop: 256 SSD 1080p CPU: Intel celeron_j3455 quad-core CPU frequency: 1.5GHz up to 2.3Ghz Memory: LPDDR3 6GB Thank you! Edit: Usage purpose mainly browser, Spotify, videos, "heaviest" thing would be nodejs for school. | I have a device on which I would like to install Ubuntu. How do I find out if Ubuntu will work on it? |
How do I generalize the equation to be able to plug in any result for $\phi(n)=12$ and find any possible integer that works? | Let $\phi(n) $ is the numbers of number that are relatively prime to n. Then, how could we solve the equation $\phi(n) = k, k > 0?$ For example: $\phi(n) = 8 $ I can use computer program to check all numbers that are relatively prime to $n$, but I think there must be an easier way to approach this problem. Base on this formula: $$\prod_{i=0}^{k} p_{i}a^{a_i} $$ The only thing I can see is n must not have a prime factor > 9, otherwise $\phi(n) > 8 $. I really don't know where to start :( ? A hint would be greatly appreciated. |
I am using as my guidance. I want to know if I understand the following concept of pass by value in java clearly. I have a java object and I pass it by value (so the address of the object, I guess in this case) to a function that calls a class constructor. The address of my main object is 'copied' to the constructor object. Now this constructed object and my main object are at the same address? or are pointing to the same address? void main(){ Result result = new Result(); //empty object Timer timer = new Timer(); timer.schedule(new UpdateResultTask(result); result.getValue(); has some valid values. Is not empty anymore. } public class UpdateResultTask extends TimerTask { private Result result; //Constructor public UpdateResultTask(Result result) { this.result = result; } @Override public void run() { // the local result object gets filled here //where response is some http response result = response.getEntity(Result.class); } } Since the change inside the local function is reflected outside in the main function, i assume that its because that at the time of construction, both the new and the old (main) object have the same address? Do I understand it correctly? In java, pass by value for objects is just passing the copy of the objects address? | I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation? |
I have been recommended to watch Full Metal Alchemist. However, the person who recommended this series to me can't remember the correct order. After googling it, I'm confused as many people have posted different orders. So what is the correct watching order of Fullmetal Alchemist? | I haven't watched Anime in many years, but recently I've had time to get back into it. I've seen that one of my favorite series, Fullmetal Alchemist, has done a series reboot. What I'm wondering is: Does it present a lot of deep variations (plot-wise, character-wise or otherwise), or is it just the same series with updated art? |
I am drawing an arrow with text above it \documentclass[tikz]{standalone} \usetikzlibrary{decorations.text} \begin{document} \begin{tikzpicture} \draw[<-, thick, postaction={decorate, decoration={text along path,text align=center, raise=.7em, text={Process}}}] (0, 0) to [bend left=60] (5, 0); \end{tikzpicture} \end{document} The result cuts off the top of the text of the label. How can I fix the bounding box of the tikzpicture so that it adjusts itself the text of the label? Can I get the decorations to extend the bounding box, the way arrows.meta does for arrows? I would like the bounding box of the tikzpicture to adjust automatically to the contents of the picture, rather than have to fine tune a fixed value. If I put the text in its own node, it doesn't get cut off, but then it doesn't follow the path of the arrow. Of course, I can not raise the text, but then it is too close to the arrow. The accepted answer has nothing to do with my problem, since the arrows.meta package doesn't change the bounding box for decorations. The other answers to that question suggest adding margins, but I do not want to have to fine tune the margin parameter (and then have to change it again, if I move the arrow decoration). | I use \draw[|-|] () to (); to draw a few intervals. I expect that each interval is rendered like |----| (see the 2nd and the 3rd intervals in the figure below). However, the top and the bottom intervals below show only a half of their endpoint lines (i.e., |). Why are these endpoint lines (|) not shown completely? How to show them? \documentclass{standalone} \usepackage{tikz} \begin{document} \begin{tikzpicture} \draw[|-|, red] (0,0) to (1,0); \draw[|-|, red, dashed] (0,1) to (1,1); \draw[|-|, blue, dashed] (0,2) to (1,2); \draw[|-|, blue] (0,3) to (1,3); \end{tikzpicture} \end{document} |
and I usually go out of my way to search for those and edit them, since this seems to be very common with iOS questions, which is where I usually live. What is interesting is that several of the questions using the form "[tag]: Why shouldn't I foo the bar?" or other similar forms aren't even tagged with [tag]. For this particular case, the fix is usually straightforward: Remove the tag term from the title Add it as an actual tag. Would it be possible to figure out the usual patterns in which tags in titles occur and batch edit the ones that fall under those cases? | So we have lots of questions that are titled like this: Specifically, questions that have one of their tags in front of their title. Thankfully, these silly users usually use a hyphen or a colon afterwards, which makes it really easy to . Can we clear up this clutter? Perhaps with a filter that strips off the excess when posting? EDIT: As an added bonus, see for another style of question title that bugs the heck out of me. |
Which is the correct option for below sentence? Who doesn't know that he is ____ universally acclaimed writter? 1) a 2) an Thanks in advance. | In the following example, is it appropriate to use a or an as the indefinite article, and why? He ate __ green apple. I know that in the case of just "apple", it would be "an apple," but I've heard conflicting answers for "green apple," where the noun is separated from the article by an adjective. Also, which is more appropriate in this case: He ate __ enormous Pop-Tart. |
Let $f:[0,1]\mapsto\mathbb{R}$ be a continuous function. Evaluate $\lim_{n\to\infty}n\int_0^1x^nf(x)dx$ | Suppose $f:[0,1]\to \mathbb{R}$ is continuous. Show that $$\lim_{n\to\infty} n\int_0^1 f(x)x^n\,dx = f(1).$$ My answer so far: First I want to assume that $f\in C^1$. Then $$n\int_0^1f(x)x^n\,dx = \left[\frac{n}{n+1}x^{n+1}f(x)\right]_0^1 - \frac{n}{n+1}\int_0^1 x^{n+1}f'(x)\, dx\\ \frac{n}{n+1}f(1) - \frac{n}{n+1}\int_0^1 x^{n+1}f'(x)\, dx,$$ which goes to $f(1)$ because the last integral goes to zero. But approximating $f$ by $\phi\in C^1$ won't necessarily work, because $\phi(1)$ may not equal $f(1)$... how can we finish the argument? |
I am trying to add two different sections to my document, a reference and a bibliography. The difference is basically this: A reference list, generally, contains only sources you have cited in-text in your assignment A bibliography, generally, is a list of all the sources you have used. This means, in addition to listing the sources you cited in-text, you also list resources that you read or referred to generate your ideas about the topic. My question is, how to automatically move references that are not cited in-text to a new section called "Bibliography" and leave the cited in-text in one called "References"? The code I am using to create the references: \bibliographystyle{agsm} \bibliography{references} I am currently using BibTex and have a file .bib, which has these references: @article{einstein, author = "Albert Einstein", title = "{Zur Elektrodynamik bewegter K{\"o}rper}. ({German}) [{On} the electrodynamics of moving bodies]", journal = "Annalen der Physik", volume = "322", number = "10", pages = "891--921", year = "1905", DOI = "http://dx.doi.org/10.1002/andp.19053221004" } @book{latexcompanion, author = "Michel Goossens and Frank Mittelbach and Alexander Samarin", title = "The \LaTeX\ Companion", year = "1993", publisher = "Addison-Wesley", address = "Reading, Massachusetts" } @misc{knuthwebsite, author = "Donald Knuth", title = "Knuth: Computers and Typesetting", url = "http://www-cs-faculty.stanford.edu/\~{}uno/abcde.html" } The latexcompanion is not being cited in-text, so the end goal would be this: | I need your help with references. I have 1 main reference section, and I want to include a second list of references as an appendix. For the main reference I use: \newpage \bibliographystyle{plainnat} \bibliography{library} The problem is that I don't know how to include the second list using a different bib file, and then calling the function \nocite{*} to show every sources inside the file. I have the appendix part workout. I need your help to design the function to call the second bibliography, and that does't interfere with the main reference: \newpage \appendix \section{Other Sources} \label{app:ReferencesB} In addition, I will prefer that the word References is not shown after Other Sources. Thank you so much!! |
I hope you can help me find this book. It's actually a series and the basic premise is that a mysterious impenetrable force field suddenly springs up over the Earth. It causes time to dilate slower inside the shield so that thousands of years pass outside of the shield but inside things remain the same. There was a Mars colony so they continue going through time with all the progress inherent with its passage. It seems there was some type of environmental problem on Earth that they needed assistance with and one day the shield suddenly drops. That's all I can recall about it at this time. Anyone familiar with this series (I think it was a trilogy) or the author? | I'm trying to recall the name of a book I read, probably published after 1990, where alien AI infects satellites and a barrier is established, isolating earth from space that maybe slows down time inside of it, relative to the passage of time outside. Mars or the moon is also colonized in an attempt to flee the now real possibility that the sun will become a red giant and wipe out humanity in the not-too-distant future (as perceived on earth), but the colony gets one of the time barriers as well. I think the name of the novel was short, "The _______" (one word). The story focused more on the human cost and followed one particular family, one member of which was somehow also partially infected by the alien AI, but I don't remember as much about them. |
I want to use thread and close my form after some operations.But I get a cross thread error .solutions? new System.Threading.Thread(s => { Close; }).Start(); | I have a scenario. (Windows Forms, C#, .NET) There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the UserControl_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can) I used a background worker thread which will be loading the data and when done will notify the application that it has done its work. Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl. The pseudocode would look like this: CODE 1 UserContrl1_LoadDataMethod() { if (textbox1.text == "MyName") // This gives exception { //Load data corresponding to "MyName". //Populate a globale variable List<string> which will be binded to grid at some later stage. } } The Exception it gave was Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on. To know more about this I did some googling and a suggestion came up like using the following code CODE 2 UserContrl1_LoadDataMethod() { if (InvokeRequired) // Line #1 { this.Invoke(new MethodInvoker(UserContrl1_LoadDataMethod)); return; } if (textbox1.text == "MyName") // Now it wont give an exception { //Load data correspondin to "MyName" //Populate a globale variable List<string> which will be binded to grid at some later stage } } BUT BUT BUT... it seems I'm back to square one. The Application again become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned. I don't know whether I perceived this right or wrong. I'm new to threading. How do I resolve this and also what is the effect of execution of Line#1 if block? The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread. So only accessing the value so that the corresponding data can be fetched from the database. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.