Are there ANY text strings that will generate the same SHA-512 Hash output?
Are ideal hashes possible to create?
Disallow downvoting other answers if I've posted my own Possible Duplicates:        As Dan Dyer mentioned in his comment on , there is a conflict of interest when you have posted your own answer and are allowed to downvote other answers.  Despite the vote editing window being drastically reduced, the fundamental problem remains: I can downvote the other answers permanently and still benefit - my answer gets upvoted ONCE and wham, I have just made up the rep loss for my 10 other downvotes. The vote editing window fixes part of the problem, but there is a more complete fix that has the extra benefit of not preventing legitimate vote changes: to disallow downvotes on competing answers when you have posted one yourself.  The temptation to wrongfully downvote competing answers is huge. The rep loss is tiny in comparison. It has to be in order for people to continue to legitimately downvote.  Details:   If I have previously voted and then post my own answers, delete my downvotes. Continue to allow me to remove the upvotes - I think this is fully legitimate. If I delete my answer it's probably best to continue to deny downvotes (perhaps even including the question), but I don't have a strong opinion either way. If your visa is on an expired passport but still valid, can you still use it with your new passport, or does the old passport have to have a recent expiration date? If so, how do you transfer your visa to your new passport? Geometric solution to find a Set of totally ordered Subsets of $ \mathbb{N} $ is uncountable My question is, does there exist a set of subsets of the naturals, $S$, such that $S$ is uncountable, where for any two subsets $A,B \in S$ we have either $A \subset B $ or $B \subset A $?  Initially my thoughts were that we could construct a chain $A_{1} \subset A_{2} \subset \cdots $ and find a bijection by picking out one element which is 'new' to each set by axiom of choice and so we have bijected to a subset of naturals, however I'm not convinced this fully works.  Furthermore, I was thinking there may be a nice elegant solution by looking for such a set in either $ \mathbb{Q}^2 $ or $ \mathbb{Z}^2 $ for example, but any attempt seems to fail due to the 'ordering' part of the question. What is a single word for a person who, as a habit, exaggerates a lot when relating information? Simulating data to fit a mediation model I am interested in finding a procedure to simulate data that are consistent with a specified mediation model.  According to the general linear structural equation model framework for testing mediation models first outlined by  and described elsewhere such as , mediation models for outcome $Y$, mediator $\newcommand{\med}{\rm med} \med$, and predictor $X$ and are governed by the following three regression equations: \begin{align} Y    &amp;= b_{11} + b_{12}X + e_1                \tag{1}  \\ \med &amp;= b_{21} + b_{22}X + e_2                \tag{2}  \\ Y    &amp;= b_{31} + b_{32}X + b_{32} \med + e_3  \tag{3} \end{align} The indirect effect or mediation effect of $X$ on $Y$ through $\med$ can either be defined as $b_{22}b_{32}$ or, equivalently, as $b_{12}-b_{32}$.  Under the old framework of testing for mediation, mediation was established by testing $b_{12}$ in equation 1, $b_{22}$ in equation 2, and $b_{32}$ in equation 3.  So far, I have attempted to simulate values of $\med$ and $Y$ that are consistent with values of the various regression coefficients using rnorm in R, such as the code below:  x   &lt;- rep(c(-.5, .5), 50) med &lt;- 4 + .7 * x + rnorm(100, sd = 1)   # Check the relationship between x and med mod &lt;- lm(med ~ x) summary(mod)  y &lt;- 2.5 + 0 * x + .4 * med + rnorm(100, sd = 1)  # Check the relationships between x, med, and y mod &lt;- lm(y ~ x + med) summary(mod)  # Check the relationship between x and y -- not present mod &lt;- lm(y ~ x) summary(mod)   However, it seems that sequentially generating $\med$ and $Y$ using equations 2 and 3 is not enough, since I am left with no relationship between $X$ and $Y$ in regression equation 1 (which models a simple bivariate relationship between $X$ and $Y$) using this approach.  This is important because one definition of the indirect (i.e., mediation) effect is $b_{12}-b_{32}$, as I describe above.  Can anyone help me find a procedure in R to generate variables $X$, $\med$, and $Y$ that satisfy constraints that I set using equations 1, 2, and 3? Note: this post is different to , which just cites part from somewhere else, without any further analysis and thinking. Furthermore, none of the answers to that post answers my question - the situations where &quot;will (going to) be doing&quot; is more appropriate.   I will be participating in IELTS test next Tuesday afternoon.  In an online class, the teacher says the following at the beginning of the lesson.  I will be using NotePod (pointed out by red rectangle) to write relevant points we talk about today.   I guess &quot;will be using&quot; is more appropriate than &quot;will use&quot; there, right?  A  explains  This &quot;tense&quot; is used for reporting a scheduled activity with special focus on its timing— as if one is standing in the future and experiencing the flow of the time. The focus is on the temporary, ongoing, or repetitive nature of the activity.   I understand the grammar rules of those verb tenses and the difference between this group  I am going to drive home tomorrow.   I am going to be driving home tomorrow.  The former is just convey my activity in the near future while the latter probably makes an implication that &quot;don't disturb me as I am driving in that time&quot; However, in the following situations, I don't see the difference between 2 verb tenses.  Welcome back to this class. Today's lesson is for the IELTS students who are going to be taking the IELTS test. it's for everybody to be honest with you. this lesson is useful for anybody who needs to do some writing.   who are going to take the IELTS test ... Credit score just tanked ~50 points and I'm not sure why I check my credit score monthly using a credit tracking app provided by my credit card company. I use a reminder to check on the same day each month, and have been tracking my credit score for almost two years.  In the last year, the app switched from a TransUnion model to VantageScore 3.0. I have TransUnion data for the entire duration, but only about a year's worth of VantageScore data.  I have good credit, and my TransUnion score has increased steadily from ~740 to ~780 in the last two years.  My VantageScore started around ~760 and increased to ~800 last month. This morning when I checked my credit score, it had dropped just over 50 points to ~750.  My TransUnion score has stayed solid at ~780.  My questions are:  Should I be concerned about this sudden change in score?  Is there any way I can determine what changed to account for the sudden change in credit score? Explaining Horizontal Shifting and Scaling User group (company) page that shows summary of all user accounts belonging to the same company/user group Set a polygon's normal's orientation as the objects local rotation orientation (if every polygon is an object) I have read that controlling FDR is less stringent than controlling FWER, such as in :     FDR controlling procedures exert a less stringent control over false discovery compared to familywise error rate (FWER) procedures (such as the Bonferroni correction). This increases power at the cost of increasing the rate of type I errors, i.e., rejecting the null hypothesis of no effect when it should be accepted.   But I was wondering how it is shown to be true mathematically?  Is there some relation between FDR and FWER? I have a third-party library which consists mainly of a large number of static (.a) library files.  I can compile this into a single .a library file, but I really need it to be a single .so shared library file.  Is there any way to convert a static .a file into a shared .so file?  Or more generally is there a good way to combine a huge number of static .a files with a few .o object files into a single .so file? Can one preserve food by periodically heating it? I get that keeping food temperature low will slow down chemical reactions and preserve food, but sometimes my sister preserves food by heating it every 6 hours or so (up to 1-2 days). Does this help preserving the food? If yes, how does it work?  If it matters, the food currently in question is , but I would appreciate a general explanation. In case anyone is wondering, she doesn't store it in the fridge because it is full. Since Ubuntu 11.10 use a new kernel, it's very difficult to have a decent support for virtualization.   VirtualBox doesn't support guest additions for ubuntu 11.10, so I can't copy to and from my ubuntu desktop and windows, which I absolutely require, plus FreeBSD seems not to be able to use DHCP without guest additions.  Virt-manager instead gives an error on launch:  Unable to open a connection to the libvirt management daemon.  Libvirt URI is: qemu:///system  Verify that:  - The 'libvirt-bin' package is installed  - The 'libvirtd' daemon has been started  - You are member of the 'libvirtd' group   unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Permission denied  Traceback (most recent call last):   File "/usr/share/virt-manager/virtManager/connection.py", line 1146, in _open_thread     self.vmm = self._try_open()   File "/usr/share/virt-manager/virtManager/connection.py", line 1130, in _try_open     flags)   File "/usr/lib/python2.7/dist-packages/libvirt.py", line 102, in openAuth     if ret is None:raise libvirtError('virConnectOpenAuth() failed') libvirtError: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Permission denied   The problem is solved by running virt-manager as root, but I don't like that. How do I change permissions to run Virt-Manager as user?  Is there a way to install guest additions on Ubuntu 11.10? Securely erase hard drive using the Disk Utility Adding hyperlinks to pop-up data in qgis2web? Does anyone know if it is possible to add hyperlinks to image fields etc. in the pop-up windows of Qgis2web?  I've had a look in the layers javascript file, but the image source path isn't rendered using html, so I can't simply append &lt;a href" to it.  The image is coming in via the usual method of having a field that contains the path of the image file.  I'd like to achieve linking of the image, like in the example below. Alternatively, I could just populate the 'more info' field with the URL, but if I did that I'd like to avoid just doing it by having a field that contains the entire URL, as some may be quite long (these will only be internal links). How do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office? How can I create an Excel spreadsheet with C# without requiring Excel to be installed on the machine that's running the code? How to disk copy with unreadable sectors? I want to clone a whole disk bytewise, something like  dd if=/dev/$SRC of=/dev/$DST bs=65536 count=$count   There are better tools for the job, which understand the file system (Windows) and work faster (I don't care), but they fail because of unreadable sectors on the old source disk.  There's actually a single invalid block I have to skip. So I thought about using dd multiple times like  dd if=/dev/$SRC of=/dev/$DST bs=65536 count=... dd if=/dev/zero of=/dev/$DST bs=65536 count=... skip=... seek=... dd if=/dev/$SRC of=/dev/$DST bs=65536 count=... skip=... seek=...   with replacing the broken sector data by zeros. Is this a valid approach? I found this  which confuses me. How do I unlock the Dream Suite in Animal Crossing New Leaf? Getting a FILE* from a std::fstream Is there a (cross-platform) way to get a C FILE* handle from a C++ std::fstream ?  The reason I ask is because my C++ library accepts fstreams and in one particular function I'd like to use a C library that accepts a FILE*.