can we have a REAL terminal connected to an Ubuntu PC now-days
What is a virtual terminal for?
for any ring $A$ the matrix ring $M_n(A)$ is simple if and only if $A$ is simple Let integer $n\geq 1$. I have obtained that for any field $k$, the matrix ring $M_n(k)$ is simple, i.e., $M_n(k)$ contains no nonzero proper two sided ideals. Now I want to prove that: for any ring $A$ (not necessarily commutative), the matrix ring $M_n(A)$ is simple if and only if $A$ is simple.   How to prove? Inserting an image in plain TeX I used the OzTeX implementation of TeX, also I used to typeset my docs in plain TeX, not LaTeX for me, so I had no problem to insert an image using the OzTeX, now I'm back to TeX docs, am using the TeXWorks frontend, but I can't insert an .eps image file, it seems the \includegraphics macro its only for LaTeX, so I can't use it, any idea on how to insert an image when using plain TeX? I'm cooking two different dishes in the oven at the same time that each require different temperatures. One is a roasted vegetable dish that says to cook at 475 for 35-40 minutes and the other is parmesan crusted pork chops at 350 for 40-45 minutes. What do you suggest I do? $f_n:[0,1]\to [0,1]$ continuous, $f_n\to f$ uniformly, prove: ${\frac1n}\sum_{k=1}^{n}{f_k} \to f$ uniformly I was able to prove, hopefully correctly, that the sum converges uniformly. But, I'm not sure how to show it converges uniformly specifically to $f$.  The way I proved it converges uniformly was by using the Dirichlet convergence test, by taking $a_k(x) = \frac1n$ and $b_k(x) = f_k(x)$. $\sum_{k=1}^n{b_k(x)}$ is uniformly bounded on $[0,1]$ by $n+2$ for instance, and $a_n$ is monotone and uniformly convergent to 0 because it does not depend on the value of $x$.  I got rather stuck after this. I guess I have to use the continuity of the functions and the uniform convergence of both, but I can't figure out how to show that they converge to the same thing. Any help will be greatly appreciated. Bridged adapter in Virtual Box - cannot obtain IP I have virtual box with RHEL installed. My virtual box is running on windows 7 64 -bit. I configured bridged connection, but when I am restarting network interfaces, I receive following error:  Determining IP information for eth1... failed   On Windows XP it works without problems. I disabled Windows Firewall and installed latest Virtual Box, still without success.   NAT is working without any problems. What did I missed?  UPDATE  Ouput of ifconfig -a is:  eth0      Link encap:Ethernet  HWaddr 08:00:27:B6:FC:69           inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0           inet6 addr: fe80::a00:27ff:feb6:fc69/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:430 errors:0 dropped:0 overruns:0 frame:0           TX packets:346 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000           RX bytes:36520 (35.6 KiB)  TX bytes:31455 (30.7 KiB)  eth1      Link encap:Ethernet  HWaddr 08:00:27:C3:84:4A           inet6 addr: fe80::a00:27ff:fec3:844a/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:1464 errors:0 dropped:0 overruns:0 frame:0           TX packets:17 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000           RX bytes:135419 (132.2 KiB)  TX bytes:4230 (4.1 KiB)  lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)   Output of route -n  Kernel IP routing table Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 10.0.2.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0 169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0 0.0.0.0         10.0.2.2        0.0.0.0         UG    0      0        0 eth0   Output of dhclient -v eth1 is:  Listening on LPF/eth1/08:00:27:c3:84:4a Sending on   LPF/eth1/08:00:27:c3:84:4a Sending on   Socket/fallback DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 6 (xid=0x6afb6c4c) DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 9 (xid=0x6afb6c4c) DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 15 (xid=0x6afb6c4c) DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 18 (xid=0x6afb6c4c) DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 13 (xid=0x6afb6c4c) No DHCPOFFERS received. No working leases in persistent database - sleeping.   Moreover the same machine with the same configuration works well on Windows XP. The problem is only on Windows 7. How do I open a terminal? Possible Duplicate:             I just got ubuntu running on my computer and now I am ready to write a program...but I can't figure out how to open a command terminal. I guess I don't know where to find which version I am running either. Any help would be appreciated. Thank you. Dynamic google-code-prettify doesn't work Blender Internal glossy BSDF equivalent? How do you configure an OpenFileDialog to select folders? In VS .NET, when you are selecting a folder for a project, a dialog that looks like an OpenFileDialog or SaveFileDialog is displayed, but is set up to accept only folders.  Ever since I've seen this I've wanted to know how it's done.  I am aware of the FolderBrowserDialog, but I've never really liked that dialog.  It starts too small and doesn't let me take advantage of being able to type a path.  I'm almost certain by now there's not a way to do this from .NET, but I'm just as curious how you do it from unmanaged code as well.  Short of completely reimplementing the dialog from scratch, how do you modify the dialog to have this behavior?  I'd also like to restate that I am aware of the FolderBrowserDialog but sometimes I don't like to use it, in addition to being genuinely curious how to configure a dialog in this manner.  Telling me to just use the FolderBrowserDialog helps me maintain a consistent UI experience but doesn't satisfy my curiosity so it won't count as an answer.  It's not a Vista-specific thing either; I've been seeing this dialog since VS .NET 2003, so it is doable in Win2k and WinXP.  This is less of a "I want to know the proper way to do this" question and more of a "I have been curious about this since I first wanted to do it in VS 2003" question.  I understand that Vista's file dialog has an option to do this, but it's been working in XP so I know they did something to get it to work.  Vista-specific answers are not answers, because Vista doesn't exist in the question context.  Update: I'm accepting Scott Wisniewski's answer because it comes with a working sample, but I think Serge deserves credit for pointing to the dialog customization (which is admittedly nasty from .NET but it does work) and Mark Ransom for figuring out that MS probably rolled a custom dialog for this task. Movie with humans battling aliens piloting giant animalistic, water-walking robots or sea warships I have memories of watching it a few years ago (I was a kid then) in the early 2000s probably; before 2010 I think. It was a movie with giant robots, and the enemies were aliens piloting what I remember as giant, more animalistic robots. I remember those animalistic ones running on water. The aliens themselves were a little taller than humans but mostly humanoid. I remember what the aliens look like a bit; most of the movie they were clad in some kind of armor, but the scene I mentioned showed one's face, if I remember well, grey skin, vividly green eyes, a beard made of some kind of quills, bald. I have this one scene that stayed crystal clear in my memories. The heroes had captured an injured alien, and other aliens attack to, in the end, just retrieve the injured one, leaving with this one without attacking further this time. I also remember the aliens going through a city in some machine (I'm actually not sure this one was piloted though) and destroying anything it perceived as a threat, from cars to security cameras. My memories are coming from years ago, so I might be wrong in a bunch of things there, but this one scene, I can assure is correct. This might remind a bit of Pacific Rim, but it isn't. (It's watching Pacific Rim that reminded me of this movie.) It doesn't seem to show up on any giant robot movie list on internet, weirdly, so I hope you can help me. And now I'm starting to wonder if there was really robots on the heroes' side. Maybe it was warships (sea ones, not spaceships). As I said it was some time ago and I was young, so bad memories are likely. Transfer Clash of Clans account from one G+ to another G+ account? Java function for arrays like PHP's join()? What exactly are genes, DNA and chromosomes. How do they relate to each other and what is their function? So I am new to biology and I have been reading, and searching the web, but I couldn't understand the whole framework of a cell. So as I understood:    A DNA, is a double chain of Nucleotides (A,T,G,C and a sugar) and a phosphate residue. Some parts of a DNA code a gene and some do not, exons and introns accordingly. As I understand it these the sequences of exons hold genes and the whole sequence is called genome. Now I read in the book Introduction to Computational Molecular Biology by J. C. Setubal and J. Meidanis. that I cite Each cell of an organism has a few very long DNA molecules. Each such molecule is called a chromosome. So each X shaped thing called a chromosome holds one DNA molecule?   Or is each "hand" of the chromosome one complete double helix of DNA so we have 23 pairs of such chromosomes? or is it that each we 23 pairs Xs?   Shouldn't we have just one uniquely identifiable DNA sequence? I am asking this, because I have also read that each chromosome encodes a different part of one's genome. Does this mean we have several DNA sequences?   This is really bothering me, since I can't figure out the correct structure of a cell.   EDIT: Now if each chromosome contains a pair of DNA helices. We have 46 chromosomes so overall within the cell there are 92 DNA sequences? All of which are the same? Or are they different? If they are different how do they code for different aspects of one's genome? Why didn't (or did) I or some other user get a hat although the requirements were (or weren't) fulfilled? GPS PPS signal corresponds to data time? I currently have an Adafruit Ultimate GPS connected to an Arduino that outputing GPS data (nmea sentences) once per second.  There is also a pin on the GPS outputting 1 PPS signal.    My question is whether the pulse of the PPS suppose to match the time that the GPS data is coming in i.e are they are coming in at the same time?    Also does PPS pulse come in at the beginning of a UTC second or is it random and simply once a second? Why do different humans look different? Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trait across the animal kingdom: one individual of one animal species looks much like another.  Why do human facial and body shapes vary so much?  I understand that human beings live in many different environments (e.g. hot and cold) and have adapted to these (e.g. through lighter or darker skin color), but there seems to be much variation that has no apparent evolutionary purpose. So does the difference have a purpose in itself? That is, did we evlove to vary in appearance, and what is the purpose of this variation? Book where human thoughts are affecting the universe Basically our thoughts are ruining everything. Like when humans are taught stars are giant balls of gas. To the rest of the universe they aren't but humans think it and destroy alien planets. I think they come to seal us off from the rest of the universe. Is liquid cooling necessary for high CPU performance over extended periods? I'm planning on building a system for high CPU and memory performance.  Graphics performance is not a major concern, as I do not plan to use it for gaming.  I noticed that liquid cooling seems to have become common since my last build, and I am wondering if it is needed in my case.  I do not plan to overclock any of the components.  The intended use for the system is primarily development and occasional compute-intensive tasks that will run on all cores continuously for several days to a week.  The system will not normally be in continuous usage like this, but it needs to be capable of occasional extended periods of continuous use at full capacity.  I have included the main components below.  CPU: i7-5960X  Memory: 64GB DDR4  Graphics card: Nvidia GeForce GT 730 2GB  Drive 1: 1TB SSD  Drive 2: 4TB 7200RPM HDD  Power supply: 700W  Is liquid cooling needed for the above build?  If not, is there any advantage in using it?  I have read reviews that mentioned liquid cooling unit failures that resulted in leaks, so I would rather not use it if it is not necessary.  Thanks! How do electrons jump orbitals? My question isn't how they receive the energy to jump, but why.  When someone views an element's emission spectrum, we see a line spectrum which proves that they don't exist outside of their orbitals (else we would see a continuous spectrum).  Electrons can be released in the form of beta decay, thus proving that they are capable of traveling outside of orbitals contrary to the statement my teacher said that they stay within orbitals. Then, to add to the confusion, the older model of rings floating around a nucleus has, from what I can tell, been outdated, which would support this model. My teacher's explanation was that the electrons made a quantum jump of some kind. How do electrons move between orbitals or do we know how they jump, excluding the reason that energy causes them to jump, and why are positrons formed sometimes instead of electrons in Beta decay?  When I'm asking "how do electrons jump" I would like to know how an electron can jump between each orbital such as how it moves and how it knows where to jump since it appears to be a jump where the electron doesn't slow into a orbital position. Specifically how they jump what is this Atomic electron transition, I understand that they jump and that they do this through absorbing and releasing energy but what is this Atomic electron transition other than what is already on the wikipedia article . A rearrangement of an absolutely convergent complex series is also absolutely convergent I just completed the following proof.  Is it valid?   Let $\sum_{k=1}^{\infty} a_k$ be an arbitrary convergent series that also converges absolutely.  Then $\sum_{k=1}^{\infty} a_k \in \mathbb{C}$ and $\sum_{k=1}^{\infty} |a_k| \in \mathbb{R}$. Let $\{b_k\}$ denote a rearrangement of the $\{a_k\}$.  That is, we have that $\{a_k\} = \{b_k\}$ yet $a_i = b_i$ needn't hold. We will first show that $\sum_{k=1}^{\infty} b_k$ converges absolutely (immediately implying it converges non-absolutely).  We will use the Cauchy Criterion on the partial sums of $\sum_{k=1}^{\infty} |b_k|$ to demonstrate this. First let $\epsilon &gt; 0$. Consider that since $\sum_{k=1}^{\infty} |a_k| \in \mathbb{R}$, we have that $\exists N_1 \in \mathbb{N}$ s.t. for all $N_1 &lt; m &lt; n$ we have   $$ \sum_{k=m}^n |a_k| \le \epsilon. $$ Now let $0 &lt; N_2$ be large enough s.t $\{a_1, \ldots , a_{N_1}\} \subseteq \{b_1, \ldots , b_{N_2}\}$.  Let $M &gt; max\{N_1, N_2\}$.  Let $M &lt; m' &lt; n'$.  Then since $\{b_k\} - \{b_1, \ldots , b_{m'}\} \subseteq \{a_{N_1}, a_{N_{1}+1},  a_{N_{1}+2} \ldots\}$, we will have that   $$ \sum_{k=m}^n |a_k| \le \epsilon \implies \sum_{k={m'}}^{n'} |b_k| &lt; \epsilon. $$ Then we have that   $$ \left| \sum_{k={m'}}^{n'} |b_k| \right| = \sum_{k={m'}}^{n'} |b_k| &lt; \epsilon $$  so that since $\epsilon$ was arbitrary, we have obtained that   $$ \left| \sum_{k=1}^n |b_k| - \sum_{k=1}^m |b_k|  \right| = \left| \sum_{k=m}^n |b_k|  \right| \rightarrow 0 $$  so that via the Cauchy Criterion for Convergence  we have that $\sum_{k=1}^{\infty} |b_k|$ converges to some  value in $\mathbb{R}$ as desired. Then it follows that $\sum_{k=1}^{\infty} b_k$ is absolutely convergent (and hence also just convergent).   $\square$