My system is not working after updating to kernel 4.15.0-23 System: Lubuntu 18.04 x64  Yesterday I tried updating my system using "Software Updater" and after the update the system wouldn't boot up!  After update it asked my to restart, I restarted and it gave me some messages while booting up but I couldn't read them because they were gone quickly..  When the system was up it couldn't connect to any wifi network.  I tried restarting and it wouldn't boot up again.. It gives me this messages:    (Check the kernel error thing)  After that, this appears:   If I press enter, it gives me the root terminal.  And this is the apt log from /var/log/apt/history.log  Start-Date: 2018-06-12  00:08:08 Commandline: aptdaemon role='role-commit-packages' sender=':1.376' Install: intel-microcode:amd64 (3.20180425.1~ubuntu0.18.04.1, automatic), iucode-tool:amd64 (2.3.1-1, automatic), linux-headers-4.15.0-23:amd64 (4.15.0-23.25, automatic), amd64-microcode:amd64 (3.20171205.1, automatic), linux-modules-4.15.0-23-generic:amd64 (4.15.0-23.25, automatic), linux-headers-4.15.0-23-generic:amd64 (4.15.0-23.25, automatic), linux-modules-extra-4.15.0-23-generic:amd64 (4.15.0-23.25, automatic), linux-image-4.15.0-23-generic:amd64 (4.15.0-23.25, automatic) Upgrade: linux-headers-generic:amd64 (4.15.0.22.23, 4.15.0.23.25), gnupg-utils:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), linux-libc-dev:amd64 (4.15.0-22.24, 4.15.0-23.25), gpg-wks-client:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gnupg-l10n:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), linux-image-generic:amd64 (4.15.0.22.23, 4.15.0.23.25), gpg-wks-server:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gpg:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), linux-signed-generic:amd64 (4.15.0.22.23, 4.15.0.23.25), dirmngr:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gpgv:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gnupg:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gpg-agent:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), linux-generic:amd64 (4.15.0.22.23, 4.15.0.23.25), gpgconf:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1), gpgsm:amd64 (2.2.4-1ubuntu1, 2.2.4-1ubuntu1.1) End-Date: 2018-06-12  00:09:44   My processor is Intel 4710hq and the update operating installed something related to AMD processors.. Maybe it broken something ?  So why my system isn't working? Is it a kernel problem? and how can I fix it?
How can I boot with an older kernel version? The latest kernel is causing problems with my sound, which worked fine with an older version. As I have only Ubuntu installed, Grub is not getting displayed while booting. How can I manually choose my kernel version while booting?
Why is my Nikon 50mm f/1.8 giving me an fEE error? I have a AF Nikkor 50mm f/1.8. When I have the aperture setting on the lens to 22 I can take photos. But when I change the dial to anything other than 22(lowest f/stop) then I get a flashing fEE message and r09 where the number of exposure left is.  I don't have the manual for this lens but am just wondering if anyone knows what the issue is here.  My camera is a Nikon D70S. Today I bought an ibook G4 from a garage sale. The people who sold it to me didn't know the password for the 2 accounts on it. Apparently it was the guys late father's laptop. Any suggestions on how to get into the laptop and set a new admin account and password? What are the criteria for questions to be selected for Hot Network Questions? Can you construct a field with 4 elements? Can you construct a field with 4 elements? can you help me think of any examples? I'm having troubles with rendering my datatable correctly. There are actions added but it seems the datatable is not high enough to view it correctly. Is it something I'm doing wrong? Or is it a bug?    This is the code for the datatable  &lt;div class="slds-text-heading_medium"&gt;Search results&lt;/div&gt; &lt;lightning:datatable data="{! v.persondata }"                      columns="{! v.personcolumns }"                      keyField="id"                     onrowselection="{! c.getSelectedPerson }"                     hideCheckboxColumn="true"  /&gt;   Here is the code for initializing the columns  //init datatable component.set('v.personcolumns', [             {label: 'Last Name', fieldName: 'LastName', type: 'text'},             {label: 'First Name', fieldName: 'FirstName', type: 'text'},             {label: 'Mailing Zip/ Postal Code', fieldName: 'PersonMailingPostalCode', type: 'text'},             {label: 'Mailing City', fieldName: 'PersonMailingCity', type: 'text'},             {label: 'Billing Street', fieldName: 'PersonMailingStreet', type: 'text'},             {label: 'Email', fieldName: 'PersonEmail', type: 'text'},             {label: 'Primary Phone', fieldName: 'PersonHomePhone', type: 'text'},             {label: 'Secondary Phone', fieldName: 'PersonOtherPhone', type: 'text'},             {type: 'action', typeAttributes: { rowActions: actions}}         ]);   And the code for adding data (the response is a list of Accounts)  component.set('v.persondata',response.getReturnValue()); Show that $|f(z_1)|=|f(z_2)|≤|z_1|^2=|z_2|^2$. Let $f\in H(B(0,1))$, $f(0)=0$, $f(B(0,1))\subset B(0,1)$. Suppose there are 2 different points $z_1$,$z_2\in B(0,1)$, s.t. $|z_1|=|z_2|$, $f(z_1)=f(z_2)$. Show that $|f(z_1)|=|f(z_2)|≤|z_1|^2=|z_2|^2$.    I have used the Schwarz-Pick Proposition to prove that $|f(z_1)|=|f(z_2)|≤|z_1|=|z_2|$ directly, but that is not enough. Thank you for help! Why doesn't matter pass through other matter if atoms are 99.999% empty space? The ghostly passage of one body through another is obviously out of the question if the continuum assumption were valid, but we know that at the micro, nano, pico levels (and beyond) this is not even remotely the case. My understanding is that the volume of the average atom actually occupied by matter is a vanishingly small fraction of the atom's volume as a whole. If this is the case, why can't matter simply pass through other matter? Are the atom's electrons so nearly omnipresent that they can simultaneously prevent collisions/intersections from all possible directions? When and where can I find the Tower's exotic item vendor (Xur Agent of the Nine)? How to make this curly 'R' (ℛ)? Which package has a similar looking fancy R or does anyone know how to make one? (Note: the line underneath the R is just the notebook paper... this is from a scanned set of notes). If $f^2$ and $f^3$ are smooth, does it follow that $f$ is smooth? Let $f: \mathbb{R} \to \mathbb{R}$ be given. Assume that the square and cube of $f$ are smooth. Is $f$ smooth? That is if $f \cdot f \in C^{\infty}$ and $f \cdot f \cdot f \in C^{\infty}$, does it follow that: $f \in C^{\infty}$   I got this from another question on SE.   So, $f(x)^2$ is infinitely differentiable, and so is: $f(x)^3$   Also, realize:  $$f(x) = \frac{f(x)^3}{f(x)^2}$$  But what can I do? I want to clear a element from a vector using the erase method. But the problem here is that the element is not guaranteed to occur only once in the vector. It may be present multiple times and I need to clear all of them. My code is something like this:  void erase(std::vector&lt;int&gt;&amp; myNumbers_in, int number_in) {     std::vector&lt;int&gt;::iterator iter = myNumbers_in.begin();     std::vector&lt;int&gt;::iterator endIter = myNumbers_in.end();     for(; iter != endIter; ++iter)     {         if(*iter == number_in)         {             myNumbers_in.erase(iter);         }     } }  int main(int argc, char* argv[]) {     std::vector&lt;int&gt; myNmbers;     for(int i = 0; i &lt; 2; ++i)     {         myNmbers.push_back(i);         myNmbers.push_back(i);     }      erase(myNmbers, 1);      return 0; }   This code obviously crashes because I am changing the end of the vector while iterating through it. What is the best way to achieve this? I.e. is there any way to do this without iterating through the vector multiple times or creating one more copy of the vector? Let's say I have the following class X where I want to return access to an internal member:  class Z {     // details };  class X {     std::vector&lt;Z&gt; vecZ;  public:     Z&amp; Z(size_t index)     {         // massive amounts of code for validating index          Z&amp; ret = vecZ[index];          // even more code for determining that the Z instance         // at index is *exactly* the right sort of Z (a process         // which involves calculating leap years in which         // religious holidays fall on Tuesdays for         // the next thousand years or so)          return ret;     }     const Z&amp; Z(size_t index) const     {         // identical to non-const X::Z(), except printed in         // a lighter shade of gray since         // we're running low on toner by this point     } };   The two member functions X::Z() and X::Z() const have identical code inside the braces.  This is duplicate code and can cause maintenance problems for long functions with complex logic.    Is there a way to avoid this code duplication? How can I "normalize" the scale of what seems to be either an infinitely large or infinitely small object I'm having issues with an obj file I've imported into Blender. At first I thought the import was broken in some way because the import would go smoothly, but there was no model to be seen. Eventually I figured out that I could snap my view to the object by pressing . on the numpad and it was in fact there, just extremely small or large (I can't tell). I've tried scaling, but the sizes are so extreme that it doesn't seem to be working. Also due to the extreme nature of the object I can only see certain parts of it at a time depending on the angle in which im viewing it at it starts to de-render the parts not directly in front of the camera. Different results between individual and batch clip of rasters in QGIS? Last night I took some night sky shots, and I've noticed that with long exposure times (15s, 30s) the time it took to store the images in the camera memory card (jpeg) took roughly as long?  The actual file size is fairly small at 1 to 3MB per file.  Any idea why this is? Suppose $A$ is a general $n \times n$ matrix and $B$ is obtained by interchanging two rows of $A$. Prove that $\det(B) = -\det(A)$ Suppose that $A$ is a general $n \times n$ matrix and $B$ is obtained by interchanging the first two rows of $A$. Prove that $\det(B) = -\det(A)$.  By general $n \times n$ matrix, I mean $$\left[\begin{matrix} a_{11} &amp; a_{12} &amp; \cdots &amp; a_{1n} \\ a_{21} &amp; a_{22} &amp; \cdots &amp; a_{2n} \\ \vdots &amp; \vdots &amp; \ddots &amp; \vdots \\ a_{n1} &amp; a_{n2} &amp; \cdots &amp; a_{nn} \end{matrix} \right]$$ I'm thinking of using the cofactor expansion of the 2nd row of the first matrix, yielding $$ \det(A) = c_{21} a_{21} + c_{22} a_{22} + \cdots+ c_{2n} a_{2n}  $$ which will be positive or negative depending on $n$ and the values of $a_{21}, \ldots,a_{2n}$, and using the same on the first row in matrix $B$ to get $c_{11} a_{21}$ etc. and then use the fact that the power of the $c$ subscripts will alter $\det(B)$ to be the opposite sign, but I'm not sure how to express all of this mathematically in a proof directly. Help please? Is the composition of two injective functions injective? I often see $I(t)\propto |E(t)|^2$. What is the exact form ? Which constants are missing to make this an equality and why are they so often omitted ? Check out the screenshot below, I want to extend my C partition (where Windows is installed) into the unallocated free space shown. This space was cleared up by shrinking the D partition. I can extend the D partition if I want to, but not the C.  Why not? automatically execute an Excel macro on a cell change