SSH: su root or sudo?
Does disabling root login enhance security?
Should I normalize word2vec's word vectors before using them? After training word vectors with word2vec, is it better to normalize them before using them for some downstream applications? I.e what are the pros/cons of normalizing them? Massive 404 attack with non existent URLs. How to prevent this? The problem is a whole load of 404 errors, as reported by Google Webmaster Tools, with pages and queries that have never been there. One of them is viewtopic.php, and I've also noticed a scary number of attempts to check if the site is a WordPress site (wp_admin) and for the cPanel login. I block TRACE already, and the server is equipped with some defense against scanning/hacking. However, this doesn't seem to stop. The referrer is, according to Google Webmaster, totally.me.  I have looked for a solution to stop this, because it isn't certainly good for the poor real actual users, let alone the SEO concerns.  I am using the Perishable Press mini black list (), a standard referrer blocker (for porn, herbal, casino sites), and even some software to protect the site (XSS blocking, SQL injection, etc). The server is using other measures as well, so one would assume that the site is safe (hopefully), but it isn't ending.  Does anybody else have the same problem, or am I the only one seeing this? Is it what I think, i.e., some sort of attack? Is there a way to fix it, or better, prevent this useless resource waste?  EDIT I've never used the question to thank for the answers, and hope this can be done. Thank you all for your insightful replies, which helped me to find my way out of this. I have followed everyone's suggestions and implemented the following:   a honeypot a script that listens to suspect urls in the 404 page and sends me an email with user agent/ip, while returning a standard 404 header a script that rewards legitimate users, in the same 404 custom page,  in case they end up clicking on one of those urls. In less than 24 hours I have been able to isolate some suspect IPs, all listed in Spamhaus. All the IPs logged so far belong to spam VPS hosting companies.   Thank you all again, I would have accepted all answers if I could. Referencing bib files with spaces in the filename I use a very custom style (not mine) and very frequently I get a heading  on the bottom of a page and the next paragraph on the top of the next page. Sometimes this paragraph may be a list or similar. The same is true for listings and the listing description.   Is there a general way how I can adjust the "badness" of these events? Or can I adjust when a section heading would be on the last, say, 3cm of a page it should go to the next page? Or can I say, if a *listing description" is on the top 3cm of a page pull 5 more listing lines from the last page onto this page?   The style I use does not use standard structure tags and environments. But lets call them section, subsection, listing and I will try to migrate them to my lingo. I am currently working on a project to create a (not prepaid) postage label.  In java, I would go about doing this by creating a bufferedimage and adding various other images to it to create what I want.  What I want is to put text, converted to an image, onto a template letter, to make a proper postage label.    For example, imagine I was given a document with blank spaces such as:  "Name: _________"  This document is in the form of an image, and I want to use apex and visualforce (the page is already constructed, I am just stuck at the image manipulation part) to add whatever name the user types in onto the image and pack it and email the new image.  The question I have here is: where do I even start?  Java is a little nicer when it comes to image manipulation, as far as I can see.  I've looked into using a web service and sending a soapxml request to return a proper encoded image, but I haven't found a web service that can do this.  Any pointers would be nice. Thanks. My code:  a = '2.3'   I wanted to display a as a floating point value.  Since a is a string, I tried:  float(a)   The result I got was :  2.2999999999999998   I want a solution for this problem. Please, kindly help me.  I was following . So the question is really hard I think. I tried using a simple way by calculating the probability of each combination that makes a sum divisible by six, but it would take forever. Does anyone have any ideas?  Suppose that we roll a six-sided die ten times. What is the probability that the total of all ten rolls is divisible by six? Viewing all my questions from Android app How do I remove snap? apt pretends it's not there but I can still call commands with it.  Trying to rm it says "read only file system"  root@tunnel:/# apt remove snap Reading package lists... Done Building dependency tree Reading state information... Done Package 'snap' is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. root@tunnel:/# snap whoami email: - biblatex: remove commas between last and first names in bibliography When is it okay to exceed the absolute maximum rating on a part? Heartbleed: What is it and what are options to mitigate it? This is a  about understanding and remediating the Heartbleed security issue.   What exactly is CVE-2014-0160 AKA "Heartbleed"? What is the cause, what OSs and versions of OpenSSL are vulnerable, what are the symptoms, are there any methods to detect a successful exploit?   How can I check to see if my system is affected? How can this vulnerability be mitigated? Should I be concerned that my keys or other private data have been compromised? What other side effects should I be concerned about? Should training data in each batch size be resample only one time or at each epoch when using mini-batch I saw some related question regarding to the fact is one should use sampling with resampling or without when using minibatch.  However my question is different.  Let's assume that I use sampling witouth replacement. Meaning that for each epoch one training example can only belong one 'batch size' group.  I want to know if one should only resample the training data (into the different batch size) only 1 time or before to start to update the parameters before each epoch.  For instance suppose I have 20 'batch size' group. Suppose at the first iteration I have sampled picture A in group 2 and picture B in group 4.  If so should picture A always stay in group 2 and picture B in group 4. Or should I resample it before to start a new epoch (e.g. at epoch 2 put picture B in group 6 and picture B in group 20). I have a question about notation specifically square brackets $[$ and round brackets $($.  My textbook doesn't explain any of this and I cannot find a reliable source online to confirm the difference.  So my question is: What is the difference between round brackets and square brackets in terms of notation in Field Theory? For example, I see $F(x)$ and $F[x]$ in my textbook and I've always assumed they were the same thing. But apparently they're not. Is there ever a time they're the same?  I wanted to know the difference, it may be a silly question but it's something I want to make sure I understand. Reference to undeclared entity exception while working with XML I am trying to set the innerxml of a xmldoc but get the exception: Reference to undeclared entity  XmlDocument xmldoc = new XmlDocument(); string text = "Hello, I am text &amp;alpha; &amp;nbsp; &amp;ndash; &amp;mdash;" xmldoc.InnerXml = "&lt;p&gt;" + text + "&lt;/p&gt;";   This throws the exception:      Reference to undeclared entity 'alpha'. Line 2, position 2..    How would I go about solving this problem? I upgraded my Nexus 4 to Lollipop a few days ago but I don't like it. I'll leave out my reasons because they're not relevant here. I wiped my phone and installed a clean stock 4.2.2 version instead. I'm happy with this.  Not long after, Android automatically downloaded the 4.3 upgrade and notifies me with the choices "Later" and "Install". I don't want to do this upgrade.  How do I:   get rid of the notification, and  remove the downloaded update (to free up precious storage space).     I have already tried choosing "Later" but the same notification immediately reappears.    Based on Google search results, I also tried going to Settings &gt; Apps &gt; All &gt; Google Services Framework and unticked "show notifications" but it still appears. Force stop or disable also doesn't seem to help, so I've re-enabled the service including notifications. I didn't see any other apps in this list that sounded relevant - did I just not see it? I have a Java process that opens a file using a FileReader. How can I prevent another (Java) process from opening this file, or at least notify that second process that the file is already opened? Does this automatically make the second process get an exception if the file is open (which solves my problem) or do I have to explicitly open it in the first process with some sort of flag or argument? To clarify: I have a Java app that lists a folder and opens each file in the listing for processing it. It processes each file after the other. The processing of each file consists of reading it and doing some calculations based on the contents and it takes about 2 minutes. I also have another Java app that does the same thing but instead writes on the file. What I want is to be able to run these apps at the same time so the scenario goes like this. ReadApp lists the folder and finds files A, B, C. It opens file A and starts the reading. WriteApp lists the folder and finds files A, B, C. It opens file A, sees that is is open (by an exception or whatever way) and goes to file B. ReadApp finishes file A and continues to B. It sees that it is open and continues to C. It is crucial that WriteApp doesn't write while ReadApp is reading the same file or vice versa. They are different processes. How can I create launchers on my desktop? How can I invest in country A to take advantage of their great interest rate while I live in country B? If I live in the US, for example, where current interest rates are practically nil, how can I take advantage of the fact that ? Notebook computer battery says: plugged in but not charging with no further information. Is the battery bad already? My 1.5 year old Dell Studio 15 notebook computer has a battery and I keep it attached to the notebook but 98% of the time I just plug in the power adapter.  Lately when I unplugged the power adapter, the battery was only good for 10 minutes, and a few days ago, when I unplugged the power adapter, the computer simply turned off.  When clicking on the battery icon on Win 7, it says "Plugged in, not charging":    is the battery dead?  Or can Windows 7 have any option to not charge the battery?  It is a Dell Studio 15, I wonder if in such case, it looks like it can be a manufacture's defect, would Dell replace the battery? (if there was a recall, then they probably would, i think).  The notebook is 1.5 year old.