Convert local time to UTC in Delphi 7
How to convert Local time to UTC time in Delphi? and how to convert it back from UTC to local time?
The difference between two periodic functions converges to zero, is this two functions identical? Changing affiliation on publication I am moving from one job to another (postdoc to tenure track) this summer and I have papers in several stages of being written, these go from handwritten notes with all the necessary arguments to under revision at a journal. All the papers will have my new contact information put on them but where is the line for changing affiliation? It seems obvious to me that the one that is still in the handwritten notes stage will get the new affiliation and that the ones under revision won't. So somewhere in between is a line.   Where is it?  There are some similar questions so far (see  and  but they do not seem to be quite the same situation since I am not changing fields and the appointments are not concurrent. Can't login with Stack Exchange OpenID when HTTPS-Everywhere plugin is active - apparent protocol mismatch I can't seem to log in with my Stack Exchange OpenID. When I try, I get the error message:     Unable to log in with your OpenID provider:      The openid.return_to parameter (.) does not match the actual URL (.) the request was made with.   It works if I disable the HTTPS-Everywhere plugin in Firefox, but if I then re-enable the plugin and go to a site on which I am not logged in (in which case login is normally nearly seamless), it fails again with the same error message, or at least something very similar.  I'm not aware of having done anything that might have caused this, although I will admit I don't recall seeing https:// in the address bar on Stack Exchange before (I do now, and that's a good thing IMO!). I was using the site  and it worked fine then, but not now... Missing processing menu in QGIS? I'm sure there is a really simple explanation to this but haven't found any pointers on this forum or elsewhere. I seem to have lost the 'processing' menu from QGIS and can't figure out how/why!? Any ideas what I might have done to make this happen?  I'm running QGIS 2.8 built against GDAL 1.10 on Ubuntu 14.04. Why are symmetric positive definite (SPD) matrices so important? I know the definition of symmetric positive definite (SPD) matrix, but want to understand more.   Why are they so important, intuitively?  Here is what I know. What else?   For a given data, Co-variance matrix is SPD. Co-variance matrix is a important metric, see this  for intuitive explanation. The quadratic form $\frac 1 2 x^\top Ax-b^\top x +c$ is convex, if $A$ is SPD. Convexity is a nice property for a function that can make sure the local solution is global solution. For Convex problems, there are many good algorithms to solve, but not for non-covex problems. When $A$ is SPD, the optimization solution for the quadratic form $$\text{minimize}~~~ \frac 1 2 x^\top Ax-b^\top x +c$$ and the solution for linear system $$Ax=b$$ are the same. So we can run conversions between two classical problems. This is important because it enables us to use tricks discovered in one domain in the another. For example, we can use the conjugate gradient method to solve a linear system.  There are many good algorithms (fast, numerical stable) that work better for an SPD matrix, such as Cholesky decomposition.   EDIT: I am not trying ask the identities for SPD matrix, but the intuition behind the property to show the importance. For example, as mentioned by @Matthew Drury, if a matrix is SPD, Eigenvalues are all positive real numbers, but why all positive matters. @Matthew Drury had a great answer to flow and that is what I was looking for. I have two tables in my database:  NEWS table with columns:   id - the news id  user - the user id of the author)   USERS table with columns:   id - the user id   I want to execute this SQL:   SELECT * FROM news JOIN users ON news.user = user.id    When I get the results in PHP I would like to get associative array and get column names by $row['column-name']. How do I get the news ID and the user ID, having the same column name? Can I include the completion of Udacity and Coursera classes I have attended in an academic CV? Can I include in my academic CV that I have attended and completed the  and  classes I have been taking? I understand that these are not anything major, but the courses definitely gives a good overview and starting formal study on the subject becomes less cryptic. If I can include them without any negative impacts, then under what section should I include them? First appearance of a predominately black cast in a TV show I was watching MeTV the other day, which is a fantastic station chock-full of old-time TV shows.  In one sitting I saw episodes of Superman, Batman, Wonder Woman, The Rifleman and Star Trek (TOS).  So it got me thinking...  None of these shows has many (if any) black actors.  And now I'm curious as to which TV show was the first to feature a predominantly black cast.  Anyone know?  I'm thinking back to What's Happening, Good Times, The Jeffersons...  But were there any before then? Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models? Java Command line arguments I am trying to detect whether the 'a' was entered as the first string argument. How can I use Web.debug.config in the built-in visual studio debugger server? Android: TextView automatically truncate and replace last 3 char of String Output from ls has newlines but displays on a single line. Why? I think I may be overlooking a relatively fundamental point regarding shell. Output from the ls command by default separates output with newlines, but the shell displays the output on a single line.  Can anyone explain this to me? I had always presumed that the output was simply separated by spaces, but now that I see the output separated by newlines, I would expect the output to be displaying on separate lines.  Example:  cpoweradm@debian:~/lpi103-4$ ls text* text1  text2  text3   od shows that the output is separated by newlines:  cpoweradm@debian:~/lpi103-4$ ls text* | od -c 0000000   t   e   x   t   1  \n   t   e   x   t   2  \n   t   e   x   t 0000020   3  \n 0000022   If newlines are present, then why doesn't the output display as:  text1  text2 text3 How do I audit my reputation? If I am concerned that my reputation score is incorrect, how can I audit it, or get a report of a detailed breakdown of my reputation? Chess Piece Combinations I came across a question yesterday about combinations, and I wanted to know what the correct answer was. The question states as follows:  There are 8 spaces that are alternately black and white. There is one king, one queen, two identical rooks, two identical bishops, and two identical knights. The king needs to be surrounded by the two rooks. Then, the two bishops can be put on any of the remaining spaces as long as one is on a black space and the other is on a white space. Finally, the queen and the knights can be placed anywhere in the remaining spaces in relation to the other pieces. How many possible arrangements are there considering these conditions? Question on determinants of matrices changing between integer matrices The following problem came up from a though I had while reading:  Let's say we have $M=\mathbb{Z}^n$ and we have another free $\mathbb{Z}$-module, $N$, inside of $M$ also with rank $n$.  We know we can make a matrix $A$ that changes $N$ to its representation in $M$ (ie has as columns the basis $N$ expressed in coordinates coming from the basis of $M$). If the index of $N$ in $M$ is $m$, I am pretty sure just from tinkering that the determinant of $A$ should also be $m$, however, I have not been able to show this.  It is unclear to me how to proceed. I though maybe I could do something related to the points in $\mathbb{Z}^n$ that are within the unit box of $N$, but I cannot really make sense of this.  Thank you for any help or direction. The default is that clicking on the folder in the unity dock opens the home directory.   Since there are shortcuts for all the sub-folders of the home directory in the sidebar already, I'd prefer the default directory to move to a different location (~/Documents).  How can I achieve this? If I just render the default cube it will look like this:   It is rendered with color depth 16. I can see there are artefacts consisting of visible "line strokes" on some of the cube faces.  The bands seems to not go darker and darker, but alternates between light and dark, or is my eye fooled?  Why?  Edit  Here comes a gradient created by gimp without banding, using the same computer: The last two digits of $9^{9^9}$ I tried to calculate the last two digits of $9^{9^9}$ using Euler's Totient theorem, what I got is that it is same as the last two digits of $9^9$.   How do I proceed further? Moving /var, /home to separate partition I am attempting to move some folders (such as /var and /home) to a separate partition after reading this guide:    I was able to move one folder successfully following guide.  However, it doesn't seem to work for multiple folders, and all my folders are dumped into the partition without proper folders.  I would like to mount /var, /home, and /tmp onto the separate partition; can someone guide me on this?