I recently changed from Windows 10 to Ubuntu, but when I try to boot after installing Ubuntu I only see a white flash and then a black screen. I'm not running Dual Boot, I did a clean install.   My specs are the following: Intel Core I5 4670k Motherboard Gigabyte Z87X-UD3H MSI GTX 750TI 8GB RAM Kingston Hyperx Fury  Before putting the encryption password this appears:  Ivmetad is not active yet,  using direct activation during sysinit Volume group "ubuntu-vg" not found Cannot process volume group ubuntu-vg  I re-installed 3 times to check if it was an error but I keep getting this black screen  If you could help me I would really appreciate it.
I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:
How to deal with variable income in the budget We have a budget planned out for various categories, and in order to make ends meet we count on child support for my wife's child from a previous marriage.  However, lately we have not been receiving this amount.  How do we deal with this in the budget?    My wife has just been "borrowing" it from our savings, but I don't think that is reasonable given that I find it highly unlikely we will ever be able to recover it.  On the other hand, she doesn't think it reasonable to cut out of her budget and cutting it out of the budget for the kids (which is where it really should be going!) isn't reasonable either. If photons have no mass, how can they have momentum? Django set default form values I have a Model as follows:  class TankJournal(models.Model):     user = models.ForeignKey(User)     tank = models.ForeignKey(TankProfile)     ts = models.IntegerField(max_length=15)     title = models.CharField(max_length=50)     body = models.TextField()   I also have a model form for the above model as follows:  class JournalForm(ModelForm):     tank = forms.IntegerField(widget=forms.HiddenInput())       class Meta:         model = TankJournal         exclude = ('user','ts')   I want to know how to set the default value for that tank hidden field. Here is my function to show/save the form so far:  def addJournal(request, id=0):     if not request.user.is_authenticated():         return HttpResponseRedirect('/')      # checking if they own the tank     from django.contrib.auth.models import User     user = User.objects.get(pk=request.session['id'])      if request.method == 'POST':         form = JournalForm(request.POST)         if form.is_valid():             obj = form.save(commit=False)              # setting the user and ts             from time import time             obj.ts = int(time())             obj.user = user              obj.tank = TankProfile.objects.get(pk=form.cleaned_data['tank_id'])              # saving the test             obj.save()      else:         form = JournalForm()      try:         tank = TankProfile.objects.get(user=user, id=id)     except TankProfile.DoesNotExist:         return HttpResponseRedirect('/error/') How to change 'et al' to italic font in citation call-outs, with 'agsm' bibliography style I seem to have clicked on something that changed my display preferences. The main site is now very minimalistic, with fewer controls and different fonts.  I want to change it back, but where is it? How can I start learning about political philosophy? I'm interested in learning about political philosophy. What are the best ways to start? Are there any websites for beginners? Are there any books such as the "For Dummies" series? Are there any audio or video introductions to familiarize myself with the terminology? Reverse (parse the output) of Arrays.toString(int[]) Pluralizing Numbered Items Proving the inequality $\frac{n^k}{k^k}\leq\binom{n}{k}\leq\frac{n^k}{k!}$ involving binomial coefficient. What is the best way of proving inequalities including binomial coefficients in general? Lets look at this example:     $$\frac{n^k}{k^k}\leq\binom{n}{k}\leq\frac{n^k}{k!}$$   What I started with is:  $$\binom{n}{k}\frac{1}{n^k}\leq\frac{1}{k!}$$ $$\frac{n!}{k!(n-k)!}\frac{1}{n^k}\leq\frac{1}{k!}$$ $$\frac{(n-1)!}{(n-k)!n^{k-1}}\leq1$$ This is where I got stuck. How can I prove that is is lower than or equal to 1? Could you give me a hint? Short story about a crew finding an ancient alien ship filled with tons of artifacts from their society How to pivot rows into columns MySQL Been looking to pivot rows (progress_check) into columns check 1, check 2 etc... No sum or totals required, just to display the results hopefully... Can anyone help, Thanks Ad Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux Why does kworker cpu usage get so high? I recently installed Ubuntu 12.04 on my Samsung laptop alongside Windows 7. Whenever I use Ubuntu (even when its idle) kworker uses almost 90% of one of 8-cores. Even though it doesn't really affect my usage, it bugs me and I am afraid of that it might harm my processor. I even tried installing another Linux distro (Linux Mint), and kworker caused the same problem. So I don't know what to do. I would really appreciate your  help. Defining scalable "white curly brackets" {| and |} (⦃ and ⦄) I would like to construct what Unicode calls "white curly brackets" that are in addition scalable. They look like ⦃ (≈{|) and ⦄ (≈|}) and have Unicode codepoints U+2983 and U+2984.  unicode-math has them as \lBrace and \rBrace, but (1) I don't presently use XeTeX or LuaTeX and (2) their design (shown in  on pages 3-4) is not to my liking: the brace part is too fat for my taste, and I would like the vertical bar to not leave any protrusions. I am trying to have them visually match the parentheses \llparenthesis, \rrparenthesis, \llbracket, and \rrbracket from stmaryrd.  Right now I am using a makeshift definition, which is sufficient for now, but the symbols don't scale (in general or with \left/\right). Here is sample code:  \documentclass{article} \usepackage{amsmath} \usepackage[only,llbracket,rrbracket,llparenthesis,rrparenthesis]{stmaryrd} % for comparison with 4 similar parenthesis symbols \usepackage{accsupp} % for ensuring the right Unicode codepoint upon pasting  \newcommand*{\llbrace}{%   \BeginAccSupp{method=hex,unicode,ActualText=2983}%     \textnormal{\usefont{OMS}{lmr}{m}{n}\char102}%     \mathchoice{\mkern-4.05mu}{\mkern-4.05mu}{\mkern-4.3mu}{\mkern-4.8mu}%     \textnormal{\usefont{OMS}{lmr}{m}{n}\char106}%   \EndAccSupp{}% } \newcommand*{\rrbrace}{%   \BeginAccSupp{method=hex,unicode,ActualText=2984}%     \textnormal{\usefont{OMS}{lmr}{m}{n}\char106}%     \mathchoice{\mkern-4.05mu}{\mkern-4.05mu}{\mkern-4.3mu}{\mkern-4.8mu}%     \textnormal{\usefont{OMS}{lmr}{m}{n}\char103}%   \EndAccSupp{}% }   \begin{document}  \noindent ok: \(\displaystyle\llbrace abc \rrbrace\) \(\textstyle\llbrace abc \rrbrace\) \(\scriptstyle\llbrace abc \rrbrace\) \(\scriptscriptstyle\llbrace abc \rrbrace\)  \noindent ok: \(\displaystyle \llbrace \frac{a}{b} \rrbrace\) \(\textstyle\llbrace \frac{a}{b} \rrbrace\) \(\scriptstyle\llbrace \frac{a}{b} \rrbrace\) \(\scriptscriptstyle\llbrace \frac{a}{b} \rrbrace\)  \noindent incorrectly scaled (\verb|\scriptsize|): {\scriptsize\(\llbrace abc \rrbrace\)} (large magnification required)  \noindent incorrectly scaled (\verb|\tiny|): {\tiny\(\llbrace abc \rrbrace\)}  \noindent \verb|\left| and \verb|\right| not possible before \verb|\llbrace| and \verb|\rrbrace|: \\ \indent \(\llbrace \left\llbracket\left\{\left[(a) \cdot bc^{2^3}\right]^4\right\}^5\right\rrbracket \rrbrace\) % Note: This is also not possible with \llparenthesis and \rrparenthesis from stmaryrd.  \noindent for comparison: \(\llparenthesis x \rrparenthesis, \llbracket x \rrbracket, \llbrace x \rrbrace; (x), [x], \{x\}\)  \end{document}   Lines 1 and 2 look just right with the present setup. Lines 3 and 4 demonstrate that my definitions don't scale. Lines 5a/b gives an example of where I would like to be able to use \left and \right. Line 6 juxtaposes different types of parentheses for visual comparison.  Is there an easy way to scale the glyphs I have constructed myself? Or is designing new glyphs the only way? While the vertical part of my glyphs doesn't leave any protrusions, the "brace part being too fat" part of my problem isn't being addressed by my code. With this in mind: I recognize that it might not be that easy to make the brace part of the glyph thinner (though if you can, more power to you), but I think that any solution that addresses the scaling problem for any manually constructed glyph cluster will be a valuable contribution to the community.    For a slightly different setup (original example code) with  \RequirePackage{fix-cm} \documentclass[12pt]{memoir} \usepackage{fixltx2e}[2006/09/13] \usepackage{amsmath} \usepackage{txfonts} \usepackage[only,llbracket,rrbracket,llparenthesis,rrparenthesis]{stmaryrd} \usepackage{accsupp}   in the preamble, one needs \mkern-5.7mu in the fourth argument to \mathchoice for "correct" scaling. To see what goes wrong in that case, it's best to include a line such as discontinuous small symbols in a footnote\footnote{\(\scriptscriptstyle\llbrace \frac{a}{b} \rrbrace\)}. This might help a potential answerer test things out. Could you please help me computing    $\Big\lfloor\underbrace{\sqrt{2017+\sqrt{2017+...+\sqrt{2017}}}}_\text{2017 roots}\Big\rfloor$? Here's a question that I share:  Show that if $D$ is a countable subset of $\mathbb R^2$ (provided with its usual topology) then $X=\mathbb R^2 \backslash D $ is arcwise connected. Let $P(x)$ be a degree $n$ polynomial with distinct roots $r_1, r_2, \cdots r_n$. Prove that   $$\displaystyle\sum_{i=1}^{n}\frac{P''(r_i)}{P'(r_i)}=0$$  My proof: We can equivalently rewrite the polynomial as $(x-r_1)(x-r_2)\cdots(x-r_n)$ and if we plug in the roots in the polynomial, we get that all of them are equal to $0$ so their first derivatives are equal to $1$ and then their second derivatives are equal to $0$ which means that all quotients are equal to $0$ and there for the sum is as well, $Q.E.D$  Don't show the solution please, but if you have a hint, feel free. Thank you. The old advice used to be to double-quote any expression involving a $VARIABLE, at least if one wanted it to be interpreted by the shell as one single item, otherwise, any spaces in the content of $VARIABLE would throw off the shell.  I understand, however, that in more recent versions of shells, double-quoting is no longer always needed (at least for the purpose described above).  For instance, in bash:  % FOO='bar baz' % [ $FOO = 'bar baz' ] &amp;&amp; echo OK bash: [: too many arguments % [[ $FOO = 'bar baz' ]] &amp;&amp; echo OK OK % touch 'bar baz' % ls $FOO ls: cannot access bar: No such file or directory ls: cannot access baz: No such file or directory   In zsh, on the other hand, the same three commands succeed.  Therefore, based on this experiment, it seems that, in bash, one can omit the double quotes inside [[ ... ]], but not inside [ ... ] nor in command-line arguments, whereas, in zsh, the double quotes may be omitted in all these cases.  But inferring general rules from anecdotal examples like the above is a chancy proposition.  It would be nice to see a summary of when double-quoting is necessary.  I'm primarily interested in zsh, bash, and /bin/sh. A Question On Euler's Proof Of the Basel Problem I've studied the proof that Euler gave for the famous , and it would seem that while it is technically correct, he does not justify all of his steps properly. Namely, he assumes that   $$\frac{\sin(x)}{x}=\left(1-\frac{x}{\pi}\right)\left(1+\frac{x}{\pi}\right)\left(1-\frac{x}{2\pi}\right)\left(1+\frac{x}{2\pi}\right)\dots$$  simply because they have the same roots, which is really not a strong enough condition. How do you really show that the equality holds?  He then notices that if you use the above equality, and consider it against the Taylor expansion for $\frac{\sin(x)}{x}$, then you can equate the coefficients of the two infinite expansions at each order, and the result of the Basel problem follows. But how do you know that if you have two different expansions for a function, then their coefficients at each order must be equal?  I would really appreciate if someone could show me how to make these two intuitive, yet informal, steps rigorous. Is there any advantage to using pedal straps over clipless pedals?