Ubuntu system totally freezes 12.04 12.10 13.04
What should I do when Ubuntu freezes?
I have a cheap Chinese made tablet from Dubai called the Crony Dubai (www.cronydubai.com). It has a micro B, mini HDMI and a USB labeled as "Host" as well as a micro SD slot. It came with a micro B to USB adapter in box, and its running Ice Cream Sandwich. Is there a way to load Ubuntu on it? Also the tablet is very buggy and crashes often, would that be due to the tablet or the OS? How does atan2 work when getting angle of a vector? I know that atan2 gives me the absolute angle of any vector. But it doesn't give a value from 0 to 360 degrees. Instead, it gives a value (if I'm not mistaken), between 0 and 180, or between 0 and -180. For example, instead of giving angle 270, it will say -90.  This is a little confusing for me. Let me try to describe how I think this works, and please tell me if I'm correct. Actually, I'll draw it.    Is this correct? I'm having a little trouble understanding this. Thanks Cancel misclicked flags How to prove the following expression does not depend on x? I'm not sure how to approach this question, but I know it has something to do with taking the derivative of this. Can anyone please help me out?  Let x > 0. Prove that the value of the following expression does not depend on x: $$\int_{0}^{x}\frac{1}{1+t^4} dt + \frac{1}{3}\int_{0}^\frac{1}{x^3} \frac{1}{1+t^\frac{4}{3}} dt$$ Show that f(x) = inf{g(x1)+h(x2)} is convex subject to x1+x2=x and where g(.) and h(.) are convex functions.  Can I just go about this by using the regular definition of a convex function or which properties should I use? I know that the sum of convex functions is convex, but the infimum part confuses me. Thank you Spaces in which "$A \cap K$ is closed for all compact $K$" implies "$A$ is closed." Let $X$ denote a topological space. For any $A \subseteq X$, consider two possible conditions on $A$.   $A$ is closed $A \cap K$ is closed, for all compact $K \subseteq X$.   If $X$ is Hausdorff, then clearly (1) implies (2). If $X$ is metrizable, then the converse holds; see .     Questions.         What are some Hausdorff topological spaces in which (2) does not   imply (1)?   For Hausdorff topological spaces: what weaker conditions than metrizability are known to imply that (2) implies (1)? Are there any interesting characterizations of those Hausdorff spaces in which (2) implies (1)? Getting javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher? Get exit status of process that's piped to another I have two processes foo and bar, connected with a pipe:  $ foo | bar   bar always exits 0; I'm interested in the exit code of foo. Is there any way to get at it? How does time work in The Matrix? If a PC's ability score increases due to an item, does it increase the corresponding modifier for the ability score or any skills/attacks? How to get the type of T from a member of a generic class or method Let's say I have a generic member in a class or method, like so: public class Foo&lt;T&gt; {     public List&lt;T&gt; Bar { get; set; }          public void Baz()     {         // get type of T     }    }  When I instantiate the class, the T becomes MyTypeObject1, so the class has a generic list property: List&lt;MyTypeObject1&gt;. The same applies to a generic method in a non-generic class: public class Foo {     public void Bar&lt;T&gt;()     {         var baz = new List&lt;T&gt;();                  // get type of T     } }  I would like to know what type of objects the list of my class contains. So what type of T does the list property called Bar or the local variable baz contain? I cannot do Bar[0].GetType(), because the list might contain zero elements. How can I do it? How to change the output redirection of a running process? I know how to redirect output and how to  in bash. Now, suppose I accidentally forgot to append the output redirection part to the command (e.g. 2&gt;&amp;1 or &gt; /tmp/mystdout) and my background process is already running for a while, can I still change to where stdout and stderr are being written to? I really would like not to kill and restart the application.  To be more specific as asked by  in his comment, I would like to fiddle with it in these scenarios in specific:   wrong output file forgot to redirect stderr to stdout   or a combination of both  E.g. I have Apache running and I can see the file descriptors:  /proc/8019/fd/0 -&gt; /dev/null /proc/8019/fd/1 -&gt; /dev/null /proc/8019/fd/2 -&gt; /var/log/apache2/error.log I'm having problems with an exercise from Apostol's Introduction to Analytic Number Theory.     Given $x$ and $y$, let $m=ax+by$, $n=cx+dy$, where $ad-bc= \pm 1$. Prove that $(m,n)=(x,y)$.   I've tried to give a proof, but I suspect it's wrong (or at least not very good). I would be very thankful for any hints/help/advice!  My proof:     We observe that since $ad-bc= \pm 1$, $ad=bc \pm 1$, and $(ad,bc)=1$.   Now, $(a,b) \mid m$ and $(c,d) \mid n$ but      $$(a,b) = ((d,1)a,(c,1)b)=(ad,a,bc,b)=(ad,bc,a,b)=((ad,bc),a,b)=(1,a,b)=1.$$      Similarly, we determine $(c,d)=1$. So, $1=(a,b) \mid m$ and $1=(c,d) &gt; \mid n$. But $(x,y)$ also divide $m$ and $n$. Since $(x,y) \geq (a,b)=(c,d)=1$, this implies that $(x,y)=m,n$. Hence   $(m,n)=((x,y),(x,y))=(x,y)$. This works:   This does not (blank image):   Notice the 1.1.1 -> 1.3.0 and SRS->CRS are the only changes.  Is this a problem with the service or is my second URL incorrect?  I've observed the same issue with other WMS services:  Works:   Does not work (blank image):   So I'm assuming it's an issue with my 1.3.0 URLs. What's the purpose of two capacitors in parallel? What's the purpose of the two capacitors in parallel on each side of the regulator in      I've seen similar setups in other similar circuits and can guess that it's related to one being polarized an one not, but I don't really understand what's going on there. Graph with Cycle and Two-Colorable i think if the graph G has an odd cycle, it's not two-colorable, otherwise it can be two colorable.   i read in one notes that the following is True: we couldent two-colorable any graph G that has cycle.    anyone could clarify me ? I often hear people saying that "I am" is the shortest sentence in the English language.  I know that there are also discussions about sentences using the imperative mood such as "Go." that would be shorter, but my question is this:  Why would we (the people saying "I am" is a full sentence) not accept "I'm" as a complete sentence?  Is there some unwritten rule about contractions that says "I'm" wouldn't be correct? Solve $\lim_{x\to 0} \frac{\sin x-x}{x^3}$ Why can a discontinuous function not be differentiable? /ə/ in a stressed syllable? According to , the schwa /ə/ doesn't occur in stressed syllables. But , Oxford Advanced Learner's Dictionary and Longman Pronunciation Dictionary say otherwise: the word "because" has been variously transcribed as /bɪˈkəz/ or /bəˈkəz/. So in which source should I believe? Or is there any error in transcription going on here? Or is "because" the only exception? And are there others?