Powershell script to display all groups and their users

I'm currently trying to write a script that displays each group and user in the domain.          Import-Module ActiveDirectory  $Groups = (Get-AdGroup -filter * | Where {$_.name -like "**"} | select name -expandproperty name)  $Table = @()  $Record = [ordered]@{ "Group Name" = ""; "Name" = ""; "Username" = ""; }  Foreach ($Group in $Groups) {  $Arrayofmembers = Get-ADGroupMember -identity $Group | select name,samaccountname  foreach ($Member in $Arrayofmembers) {  $Record.Set_Item("Group Name", $Group)  $Record.Set_Item("Name", $Member.name)  $Record.Set_Item("Username", $Member.samaccountname)  $objRecord = New-Object PSObject -property $Record $Table += $objrecord  }  }  $Table | export-csv "C:\temp\SecurityGroups.csv" -NoTypeInformation   It always returns these errors:  New-Object : A positional parameter cannot be found that accepts argument '+='. At C:\Users\tech\Desktop\list.ps1:17 char:14 + $objRecord = New-Object PSObject -property $Record $Table += $objrecord +              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     + CategoryInfo          : InvalidArgument: (:) [New-Object], ParameterBindingException     + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.NewObjectCommand  New-Object : A positional parameter cannot be found that accepts argument '+='. At C:\Users\tech\Desktop\list.ps1:17 char:14 + $objRecord = New-Object PSObject -property $Record $Table += $objrecord +              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     + CategoryInfo          : InvalidArgument: (:) [New-Object], ParameterBindingException     + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.NewObjectCommand   Repeating over and over.  Any help would be greatly appreciated!  BTW This is server 2012 R2


I have read this question where anna v says:  The photon is an elementary particle in the standard model of particle physics. It does not have a wavelength.   And this one where Emilio Pisanty says:  Photon frequency and wavelength are the same as the corresponding classical mode. If the state of the field is such that there is, whenever you look, only one excitation present, then we say the field is in a single-mode, single photon state. This photon then has a well-defined frequency (ν=ω/2π) and wavelength (λ=2π/k).   And if you look on this site, you find numerous occasions where people talk about the wavelength of a single photon.   Naively, I would think that a photon does have energy, and frequency associated with it, and since frequency and wavelength are inversely related (in vacuum), even a single photon could have a wavelength too. But if I interpret it as a point particle defined in the standard model, then the meaning of wavelength is not so obvious. Question:  Does a single photon have a wavelength or not?


E: Type 'echo' is not known mono-xmarin.list issue

can anyone help me with this issue. I have been using Ubuntu for years and never encountered a problem until now. I cannot update because of this error:  E: Type 'echo' is not known on line 2 in source list /etc/apt/sources.list.d/mono-xamarin.list E: The list of sources could not be read. Go to the repository dialog to correct the problem. E: _cache->open() failed, please report.


For all $x$ which are real numbers, prove that $\lfloor 2x\rfloor = \lfloor x\rfloor + \lfloor x+0.5\rfloor.$

For all $x$ which are real numbers, prove that   $$\lfloor 2x\rfloor = \lfloor x\rfloor + \lfloor x+0.5\rfloor.$$   I know that  Let $\lfloor x\rfloor = n$  $n \leq x < n+1$


Closed form solution for slope coefficients in bivariate regression

In a univariate regression, $Y=a+bX+e$, the solution for slope b is given by $COV(X,Y)/VAR(X)$.  Is there a similar expression for a bivariate regression $Y=a+bX+cZ+e$. What is the closed form solution for b and c in this case?


How can I give a specific name to every saved image?  This is the code that I have now    for i in img_list:     im = PImage.fromarray(i)      im.save(dir + '/' + 'img' + str(i) +'.tiff', 'tiff')    The problem is that when they are saved the name of the images is img and the respective numpy array.  I would like to have an output like  img_1.tiff  img_2.tiff  and so on


How to get back to photography after having a long break?

I recently had to take almost a year long break from photography. Not sure how much I've missed, may be a few new equipment releases or some new technologies. However, I think I am willing and ready to get active in photography again but since I've been inactive for quite a while I am struggling with it. The local communities have all new faces and I don't think at this stage I can restart from zero. I bought a new lens hoping it'll kick me active, but nope!  I know this sounds too stupid, but may be someone out there has been in my shoes and can share his experience with me?


jQuery to show alert on form value change

I have a button and a canvas. On button press, a new box can be created. Each box created this way includes a form with two input fields: a select dropdown and an integer input field. I would like to detect any time the value in any of the select dropdowns changes. Imagine that the user has pressed the "New Box" button, hence having created three boxes with the above-mentioned form. Whenever they make any change in any of the select options, an alert should pop up. Since all boxes created have the same indi-box class name, and the select tag has a name attribute of chosen_string, as well as following , I came up with the following jQuery snippet: // check for value change in any of the forms $(document).ready(function(){   $(".indi-box select[name='chosen_string']").on("input", function(){     alert($(this).val());    }); });  However, no alert message pops up. I tried changing my selectors by (1) also including #canvas, and (2) only including select[name='chosen_string'] nothing else but none of these helped. I placed the full functioning code .


When does an infanthood end and toddlerhood begin?

We have a 6 month old little boy.  His baby mattress has a side that's firm (for infants) and a side that is soft (for toddlers.)  He's about 19 lbs (last time weighed) and I am wondering when should I flip his mattress over.  But more generally, for future reference, when does child stop being an infant and becomes a toddler?  [edit]  The reason why I asked this is that I want to know the transition period from when a child stops being an infant and becomes a toddler.  I figured that a toddler stops being a toddler around 3 - 4 years and my kid is nowhere near there.


I have data in MySQL such as "регистрацией в партнерской" but when it comes out in PHP echo'ed out it comes out as ????. My issue here is that I believe I have tried the obvious (see list below), so what else could I be missing?   SET NAMEs is UTF8 in Mysql There is a  header I have tried with/without utf8_encode / utf8_decode I've tried mb_convert_encoding My table (Innodb) charset is utf8 with utf8_general_ci   If this is a direct duplicate please show me but I think I've hopefully covered the initial checks I should have!


I've got zero experience with drawing in real life and I don't have a tablet. Neither do I know anything about human proportions. But I do know my way around Photoshop & Pixelmator. My goal is to draw people somewhat like:    Are there any good tutorials or books out there which I should check out? I don't want to mess with it until it looks good, I'd rather start bit by bit so I get good at it.  (Image from American Presidents by )


I have an iMac with a PowerPC chip in it. Can Ubuntu run on it? I have Mac OS X 10.4.11 running on it right now. The brand is Apple.


Is length matching is necessary on I2C, UART signals, and SPI?

I am currently designing a board where there is a UART, as well as SPI and I2C, should I length match or take care of differential pairs on those interfaces?


Why is darker skin a better defense against sun than lighter skin?

We know from physics that the colour of something comes from the light it reflects.  Dark/Black objects absorb most light while light/white objects reflect most light.  Sunburn is the absorbance of too much light and is bad for your skin's health suggesting that absorbance of light is bad for you.  So why is darker skin better than lighter skin for high sun intesity living conditions? Logically darker skin should absorb more light (and so energy) while lighter skin should reflect most light (and energy).


How long should I leave my poor soul out there to wander the wastelands?  I see that his SPECIAL S & E skills have a blue increase bar - but the status time just keeps going up instead of counting down.  When should I call him back - or will he come back on his own?


CP: max source files number arguments for copy utility

Consider that there are countless number of files under /src/  cp /src/* /dst/   How many files cp will successfully process?


I installed TexLive through Software Center of Ubuntu. However it does not contain tlmgr which is quite useful to update the packages.  Is it possible to use tlmgr with default TexLive? If yes, how can I only install tlmgr (without installing TexLive 2011)? I ran install.pl script in the downloadable TexLive 2011 installer folder, but I could not find a way to install only tlmgr.  Thanks.


How do you raise your dough in cold seasons?

It is winter down here in Australia and I find it challenging to find a warm spot to raise my bread dough. What I have been doing is placing the dough in the oven (not switched on) with a pot of hot water, replacing it once or twice. The oven becomes a warm and moist environment for the yeast to do its magic.   What other alternative spots are there to raise the dough in cold seasons?


Referencing a character's position inside a loop with Python

How can I write a loop in Python that behaves exactly like this JavaScript loop:  for (i = 0; i < cars.length; i++)   That is, I want the variable i to hold the value of the index of the character as I iterate over a string.


Who was the "green-eyes" that Arya was supposed to murder?

We saw Melisandre tell Arya:      "I see a darkness in you. And in that darkness, eyes staring back at me: brown eyes, blue eyes, green eyes. Eyes you’ll shut forever."   and sure Arya      killed Walder Frey (brown eyes) and the night king (blue eyes)   Did the writers include this only to raise theories such as Arya killing Cersei or Daenerys?  What is the plot about the green eyes?


Closure of a certain subset in a compact topological group

Suppose that $G$ is a compact Hausdorff topological group and that $g\in G$. Consider the set $A=\{g^n : n=0,1,2,\ldots\}$ and let $\bar{A}$ denote the closure of $A$ in $G$.  Is it true that $\mathbf{\bar{A}}$ is a subgroup of $\mathbf{G}$?  From continuity of multiplication and the fact that $A\cdot A\subseteq A$ it is clear that $\bar{A}\cdot\bar{A}\subseteq\bar{A}$. therefore, $a,b\in \bar{A}$ yields $a\cdot b\in \bar{A}$. However, I am having trouble showing that inverses of elements in $\bar{A}$ are also in $\bar{A}$.


If $p$ and $q = 2p + 1$ are both odd primes, show that $-4$ and $2(-1)^{(1/2)(p-1)}$ are both primitive roots modulo $q$.   I cannot get heads nor tails of how to even start this let alone finish it


Jackson objectMapper.readValue() not reading the JSON from a string

I followed the tutorial on  and there is no error in the syntex. There seems to be no problem in the code and I have added the JACKSON jar files to the library also in Netbeans using the standard method of adding a library to a Netbeans project. Still I am unable to convert the JSON string to the java object. Here is my code.  class Car {      private int doors;     private String brand;      public int getDoors() {         return doors;     }      public void setDoors(int doors) {         this.doors = doors;     }      public String getBrand() {         return brand;     }      public void setBrand(String brand) {         this.brand = brand;     }      void printCar() {         System.out.println("car.brand = " + getBrand());         System.out.println("car.doors = " + getDoors());     }  }//class Car ends here.   Here is the code using method readValue of class ObjectMapper  import com.fasterxml.jackson.databind.ObjectMapper; import java.io.IOException; import java.util.logging.Level; import java.util.logging.Logger;  public class ObjectMapperExampleWithString1 {      public static void main(String args[]) {         ObjectMapper objectMapper = new ObjectMapper();          String carJson                 = "{ \"brand\" : \"Mercedes\", \"doors\" : 5 }";          Car car = null;         try {             car = objectMapper.readValue(carJson, Car.class);         } catch (IOException ex) {             Logger.getLogger(ObjectMapperExampleWithString1.class.getName()).log(Level.SEVERE, null, ex);         }         if (car != null){             car.printCar();         }else{             System.out.println("Object car of type Car is null. Problem!!!");         }      } }   And here is the exception that I get.     run:   Exception in thread "main" java.lang.NoSuchMethodError: com.fasterxml.jackson.databind.JavaType.isReferenceType()Z       at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findDefaultDeserializer(BasicDeserializerFactory.java:1522)       at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.findStdDeserializer(BeanDeserializerFactory.java:167)       at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:132)       at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:403)       at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:352)       at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:264)       at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)       at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)       at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:461)       at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:3804)       at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3698)       at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2714)       at myJackson.ObjectMapperExampleWithString1.main(ObjectMapperExampleWithString1.java:18)   Java Result: 1   BUILD SUCCESSFUL (total time: 0 seconds)


Move Show Applications menu to the top of the sidebar (dock) menu in 18.04

Right now I'm using Ubuntu 18.04 and there is a Show Applications menu at the bottom of sidebar menu as shown in the screenshot:    In Magento 16.04, the Show Applications menu appears at the top of the sidebar menu and I want to make Ubuntu's menu appear in the same location,  just like the 16.04 version. How can I achieve this?


Searching inside archives for specific files and patterns

Is it possible to grep inside a bunch of archives with regular expressions on both the names of the files they contain and the contents of those files? I would like to know which files in which archives match the pattern. I'm on OS X, if it matters.


Let $f(x)$ be differentiable at $\mathbb R$, s.t $|f^\prime (x)| \le 6$ . Its given that $f(1)=20$, and $f(9)=68$ , prove that $f(7)=56$.

Let $f(x)$ be differentiable ate $\mathbb R$, s.t $|f^\prime (x)| \le 6$ for every $x$ in $\mathbb R$. its given also that $f(1)=20$, and $f(9)=68$ , prove that $f(7)=56$.  I'm thinking about applying  $\text{Mean Value theorem}$ and $\text{Intermediate Value theorem}$, in here but for some reason I miss something and I can't conclude that $f(7)=56$. any kind of help would be appreciated.


Color the space under the ploted line in a pgfplot


Can Ubuntu be installed on an old laptop as an operating system?  Is Ubuntu an operating system or does it operate as a browser only?


Is R-squared value appropriate for comparing models?

I'm trying to identify the best model to predict the prices of automobiles, using the prices and features available on automobile classified advertisement sites.  For this I used a couple of models from the scikit-learn library and neural network models from pybrain and neurolab. The approach I used so far is to run a fixed amount of data through some models(machine learning algorithms) and compare there $R^2$ values which was calculated with the scikit-learn metrics module.   Is $R^2$ a good method to compare the performance of different models? Although I got quite acceptable results for models such as Elastic net and Random forests I got very poor $R^2$ values for Neural network models,so is $R^2$ an appropriate method for evaluating neural networks (or non-linear methods)?


I introduce shift $t^5=2x -3$,but it doesn't help $$\int \frac{2\sqrt[5]{2x-3}-1}{\left(2x-3\right)\sqrt[5]{2x-3}+\sqrt[5]{2x-3}}dx$$


In Ubuntu versions before Gnome Shell, I could set what I wanted to happen when I close the laptop lid depending on whether the laptop is connected to power or not.  Now the default is standby which I can disable in Gnome Tweak Tool. My preferred setting is to only go to standby when on battery and stay on when connected to AC.  Using systemd I only know of options to completely enable or disable lid-actions alltogether. How did Unity solve this in Ubuntu 17.04?


I have the latest firefox os device --the flame-- the developer reference device. I was wondering if it is possible to install android on it.   Given that FirefoxOS is built on top of Android kernel and use the same drivers, albeit with different GUI and less buttons. Would that be possible?  This question is very specific to the flame device, so it's different from


What's the word for speech that talks about someones achievements, their character etc, like you would in a eulogy, except they're not dead.   For example, they might be receiving an award.   What do you call this speech?


Let $f \in \Bbb C[x_1, ..., x_n]$ be a homogeneous polynomial of degree $d$, and assume that $f=gh$, where $g,h \in \Bbb C[x_1, ..., x_n]$. Is it true that $g$ has to be a homogeneous polynomial of degree $k \leq d$.  I tried to write $$f(\lambda x_1,  ...,  \lambda x_n) = \lambda^d f(x_1, \dots, x_n) = g(\lambda x_1,  ...,  \lambda x_n)h(\lambda x_1,  ...,  \lambda x_n) = \lambda^d g(x_1, \dots, x_n) h(x_1, \dots, x_n)$$  for all $\lambda, x_i \in \Bbb C, \lambda \neq 0$. What can I do next?


Why did my question receive many downvotes?

I would like to understand Stack Exchange better and improve my questions' and answers' quality, and this is why I would like to ask the following:  Recently I asked a question here, on Meta, which is received so many downvotes. I would like the understand why, and how can I avoid this? Even better, how can I ask that particular question to receive upvotes? The question is this:   I searched for answers here, on Meta, and I found , but it didn't help me to understand my problem.


Designing an ABBA circuit (3 input, 2 output) inputs: (GND, +V, Logic)

I'm working on a relatively simple Arduino project and want to reach an elegant solution for a circuit. I'm not sure if there is an existing IC for what I want to do, but here is a diagram for what I'm attempting to accomplish.  When googling the solution I found the name to be an ABBA circuit (tagged by minecraft sadly), essentially I have 2 inputs which need to be switched when a 3rd logic trigger is activated. Can I do this with a single device? Or is there a more complex solution?  More stats: +3V line has ~170 mA of current Logic Switch is a +5V line with ~47 mA of current (Digital pin)  Thanks for taking a look and I appreciate any help given.


equivalent of showframe on generic boxes (for debugging)

I have done a lot of searching but cannot figure out how to visualized the box that a piece of content falls into without shifting the content. How do you debug?  Note:  could be a good question if it had answers that worked without lua. But, also that OP is specifically looking to outline all boxes which I am not. If I were able to get that to work, I'd probably have a whole new problem interpreting what I see.


Can use this expression "Couple questions" for more than two questions ?

I mean when we mention couple , we make a reference to two stuffs.   But I want to use it in a title to mean more than that. is this correct ?  To illustrate that: is the following title correct ?     Couple questions about your latest articles   What I want to mean by that :      multiple questions about on of your last article


What is the minimum value of $\operatorname{trace}(AA^T)$

$A_{n\times n}$ be a non singular matrix, could any one tell me what is the minimum value of $\operatorname{trace}(AA^T)$


Clicking the ellipsis between page numbers should prompt for a page number

It's pretty hard to get to page 500 when the navigation tool looks like this: 1 2 3 4 5 … 3896 next If clicking the ellipsis (…) produced a prompt allowing users to type in the desired page, that would be awesome. Editing the URL is not easy on small touchscreens. It's hard to click on the right character position in the URL. EDIT: Since this was closed as a duplicate for another question, I added my suggestion as an  over there.


Why I'm getting "macOS can't repair the disk"

I'm using Macbook Pro Mid 2012 on Sierra. It has two partitions without OS partition. Four times those 2 partitions getting corrupted(can't copy files). And I tried to repair disk, And got this message    After I restart my MBP got this.    So as they said I copied the data and reformat it to "Mac OS Extended (Journaled)". Again in 2 days one partition got corrupted. So then I realize File system was "Mac OS Extended (Journaled)" and now it shows only "Mac OS Extended".    Rashs-MacBook-Pro:~ rashmendis$ sudo gpt -r show disk0 Password:        start        size  index  contents            0           1         PMBR            1           1         Pri GPT header            2          32         Pri GPT table           34           6                    40      409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B       409640   781975184      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC    782384824     1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC    783654360   715947032      4  GPT part - 48465300-0000-11AA-AA11-00306543ECAC   1499601392      262144            1499863536   453399448      5  GPT part - 48465300-0000-11AA-AA11-00306543ECAC   1953262984      262151            1953525135          32         Sec GPT table   1953525167           1         Sec GPT header  Rashs-MacBook-Pro:~ rashmendis$ diskutil list /dev/disk0 (internal, physical):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *1.0 TB     disk0    1:                        EFI EFI                     209.7 MB   disk0s1    2:          Apple_CoreStorage MacOS                   400.4 GB   disk0s2    3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3    4:                  Apple_HFS Backup                  366.6 GB   disk0s4    5:                  Apple_HFS Data                    232.1 GB   disk0s5  /dev/disk1 (internal, virtual):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:                            MacOS                  +400.0 GB   disk1                                  Logical Volume on disk0s2                                  6E77AA56-7B2E-4388-9640-F34D7E92164C                                  Unencrypted   Issues having with disk0s4 and disk0s5.   I need to know is this a problem of my HDD drive or a issue with the OS.


Cannot install Nvidia Driver on Ubunutu 18.04

Hello I am trying to install the official nvidia driver for my Ubuntu 18.04.The error I get is :  You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies:  libnvidia-ifr1-390 : Depends: libnvidia-gl-390 but it is not going to be installed  libnvidia-ifr1-390:i386 : Depends: libnvidia-gl-390:i386 but it is not going to be installed  nvidia-390 : Depends: nvidia-driver-390 but it is not going to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).   After I run apt --fix-broken install as said , and gives me:  (Reading database ... 194729 files and directories currently installed.) Preparing to unpack .../libnvidia-gl-390_390.67-0ubuntu0~gpu18.04.1_i386.deb ... diversion of /usr/lib/i386-linux-gnu/libGL.so to /usr/lib/i386-linux-gnu/libGL.so.distrib by nvidia-340 dpkg-divert: error: mismatch on package   when removing 'diversion of /usr/lib/i386-linux-gnu/libGL.so by libnvidia-gl-390'   found 'diversion of /usr/lib/i386-linux-gnu/libGL.so to /usr/lib/i386-linux-gnu/libGL.so.distrib by nvidia-340' dpkg: error processing archive /var/cache/apt/archives/libnvidia-gl-390_390.67-0ubuntu0~gpu18.04.1_i386.deb (--unpack):  new libnvidia-gl-390:i386 package pre-installation script subprocess returned error exit status 2 Preparing to unpack .../libnvidia-gl-390_390.67-0ubuntu0~gpu18.04.1_amd64.deb ... diversion of /usr/lib/x86_64-linux-gnu/libGL.so.1 to /usr/lib/x86_64-linux-gnu/libGL.so.1.distrib by nvidia-340 dpkg-divert: error: mismatch on package   when removing 'diversion of /usr/lib/x86_64-linux-gnu/libGL.so.1 by libnvidia-gl-390'   found 'diversion of /usr/lib/x86_64-linux-gnu/libGL.so.1 to /usr/lib/x86_64-linux-gnu/libGL.so.1.distrib by nvidia-340' dpkg: error processing archive /var/cache/apt/archives/libnvidia-gl-390_390.67-0ubuntu0~gpu18.04.1_amd64.deb (--unpack):  new libnvidia-gl-390:amd64 package pre-installation script subprocess returned error exit status 2 Errors were encountered while processing:  /var/cache/apt/archives/libnvidia-gl-390_390.67-0ubuntu0~gpu18.04.1_i386.deb  /var/cache/apt/archives/libnvidia-gl-390_390.67-0ubuntu0   I have tried purge, clean install and none of these work.


I am using Linux first time. I have installed Ubuntu 12.04, but after installing it, it is not showing me the drives or my data. In Disk Utility it is not showing any partition.  Actually i just want to know that my data has been lost or not.  I am unable to show you through screenshot because of repuatations.  Output of sudo parted -l:  Model: ATA SAMSUNG HM641JI (scsi) Disk /dev/sda: 640GB Sector size (logical/physical): 512B/512B Partition Table: msdos  Number  Start   End     Size    Type     File system     Flags  1      1049kB  2463MB  2462MB  primary  fat32           hidden, lba  2      2463MB  636GB   633GB   primary  ext4            boot  3      636GB   640GB   4204MB  primary  linux-swap(v1)   will somebody help me to recover my data through remotely..?


Is Ubuntu Phone's GUI going to be ported to desktop Ubuntu?

Now that even cheap laptops are coming with touchscreens I was wondering if Canonical plans to include its new touch version of Unity GUI on regular Ubuntu for use in laptops and desktops.


Why did Snape help Harry in the Philosopher's Stone?

I've read all the books years ago. While I was re watching the movies earlier, some things don't tie up.  In the Philosopher's Stone: Why was Snape helping Harry all the time, and why he was questioning Quirrell on which side he really was? I remember very well that in the Deathly Hallows Snape pretended to the end to be Voldemort's Death Eater.   My question is how did Voldemort trust Snape in book 7 if in book 1 he was trying to stop Quirrell.   And Voldemort was aware about it:     "Yes, Severus does seem the type, doesn't he? So useful to have him swooping around like an overgrown bat. Next to him, who would suspect p-p-poor, st-stuttering P-Professor Quirrell?"   —Quirrell (possibly influenced by Voldemort) on Harry's suspicions about Snape after revealing himself


I have the Windows version of Steam installed on my laptop...since it's a laptop I'll be wanting some of that space back, but I don't know how to uninstall a .exe file. I have the latest WINE-Staging installed and I'm running the latest Ubuntu 18.10.


put text by link style in lightning datatable

I want to put data in lightning datatable by url link style like attached to express the record of relationship.  I tried header type "url", but it showed "http//" in the cells.  How can we put data by url style?  Thank you in advance.


how can I prevent from sql injection I saw a tutorial where the hacker can check if the website was easy to hack by just adding ' to the url and if it was it would display the error and the line where the error was at. this is my sql  $sql = "SELECT * FROM sell_table WHERE 1=1";   if ($names) $sql .= " AND names='" . mysql_real_escape_string($names) . "'";   if ($prices) $sql .= " AND prices='" . mysql_real_escape_string($prices) . "'";   this is a line that make a name in to a link   $strLink = "" .$strName.  "";    how can I prevent this from sql injection


We are shifting our MS windows lab to Linux.  I want to set up a custom ISO with our required software and remove unwanted software from ISO. This may help us in saving internet bandwidth and time in setting the same software for our lab PCs.  Ansible can install all required software but it is using the internet,   thanks


Can you help me regarding the Centre of $GL(n,\mathbb{R})$ $?$  It is easy to see that the diagonals are there. what could be the other elements? It may be an useless question but it came to my mind! Any help will be appreciated.


Installing Ubuntu on my F205TA laptop - a LOT of problems!

I've been using Windows my whole life, and I really want to test Ubuntu out on my Notebook (ASUS F205TA-BING-FD018BS, Windows 10 installed).  I have tried several options in doing so (installing over USB, SD, rEFInd, easyUEFI, you name it...), but nothing seemed to work. My laptop just skips those options, no matter what I do.  Edit: Not a duplicate of , I tried this solution already and it doesn't seem to work.


Schengen visa: appointment not available

I and my husband are traveling to Italy, Switzerland and Netherlands in June. Our period of stay in Italy and Switzerland is almost the same, with 5N/6D in Switzerland and 6N/7D in Italy. Unfortunately, we are not able to find an appointment date at Italy consulate in SFO before our departure. Our flight and hotel reservations are done. We are wondering if we can take up visa appointment at Swiss consulate in SFO. If not, what are the chances of getting an emergency/expedited appointment at Italy consulate within 20 days of departure. Please help us here and let us know if it's possible to do so. Any suggestions would be appreciated. TIA


Calculating the length of the semi-major axis from the general equation of an ellipse

What is the most accurate way of solving the length of the semi-major axis of this ellipse?    $-0.21957597384315714 x^2 -0.029724573612439117 xy -0.35183249227660496 y^2 -0.9514941664721085 x + 0.1327709804087165 y+1 = 0$    The answer should be extremely close to the correct value of the length of the semi-major axis which is equal to $3.073400961177073$    I already tried to rotate the graph so that the major axis will coincide with the x-axis making the xy term equal to zero, then I made it into standard form, in which I was able to calculate the length of semi-major axis. However, the result differs from the true value by about $0.1$ . This difference is not acceptable since this value will be used many times for the orbit propagation formulas and in our final computation, the result has about 5% error. We could not accept this 5% error since our goal is to have an error of at least 2%. Thank you in advance.


How to compute the self-energy of a sphere? Electrostatics

Not just the formula, how to derive it as well, im lost in this topic any help would be great.


Bowling ball on a rubber sheet analogy - what pulls the ball down

Possible Duplicate:          Since I read Cosmos long ago, I see the same analogy about the balls rolling on a rubber sheet used to explain how gravity works. But a ball rolls on a surface because gravity is pulling it down. In space it will follow a straight line and go over any hole on the surface.  So, in the analogy we all know, where the curvature of the rubber sheet is gravity, what is pulling the ball down? If space is curved, what keeps an object attached to that "surface" of space?


The limitations of Elastic-net regularization

I know that Elastic-net regularization is the combination of L1 and L2 regularization.  My question is what are the limitations of Elastic-net regularization?    My question is not related to Elastic-net regularization compared to LASSO or Ridge. Just, I would like to know the possible flaws of Elastic-net regularization.


How to return only the Date from a SQL Server DateTime datatype

SELECT GETDATE()   Returns: 2008-09-22 15:24:13.790  I want that date part without the time part: 2008-09-22 00:00:00.000  How can I get that?


I am trying to convert a time column into datetime but the column looks like this '2020-01-07T22:24:20.000Z'

I scraped data from Twitter and I got my date format as 2020-01-07T22:24:20.000Z. I need to convert it to datetime format.


So I would like to send more than 1 datas from PHP to vb.net how can I do that?  I tried for example this:  PHP:  name=test&password=123456&email=test@gmail.com   But how can I get this data in vb.net into strings?  Dim data = "name=test&password=123456&email=test@gmail.com" Dim name = data("string")   ??  Or how?


Review audit honeypot messes with tags; leads to wrong comments left

showed up in the close review queue for C++:    I was leaving a comment as to the inappropriateness of the c++ tag for this question, when I went to the question and found this:    The question does not have the c++ tag, and has never been revised.  Surely any ninja revision would be over a week old, far too old to influence the close queue filtering.  Diamond mod Oded was able to confirm that the honeypot messes with tags sometimes.  That's bad, because it messes with the quality of the question and you can no longer make a judgement about the user's reaction when you show them an alternate version of the question.  In this case I was leaving a negative comment using the review queue, and it did show up on the real question!  Of course I deleted it because I realized that it wasn't deserved, but if I was only paying enough attention to decide the question was ok (I do know enough Java for that), then I might not have visited the question.  If you're going to make a fake version of a question to show the reviewer, then review actions including commenting need to be disassociated from the real question.  In order to not discard useful comments, you may need to drop the facade if the reviewer tries to leave a comment, and send them to the real question to decide whether it still applies.  Related but different:  (different because there the system recognized that the tag wasn't present, and passed it through the filter anyway)  Edit: Neither of the linked questions, or answers, address comments left on faked answers via the review audit system.  There's a solitary comment that mentions the issue, but nothing is resolved, since it isn't answered.  This bug report is separate from those two.


Why is there not a register that contains the higher bytes of EAX?

%AX = (%AH + %AL)  So why not %EAX = (%SOME_REGISTER + %AX) for some register %SOME_REGISTER?


When a > is encountered in a HTML comment the comment breaks. Take the following markdown source: <!-- Here is an example of this working fine.  And a second line to show that's not the problem. -->  <!-- This isn't visible like you would expect.  > Everything from here is visible. -->  Which renders as:    Everything from here is visible. -->   Here is an example of the above part of the question in the preview screen.    There are two comments, one completely hidden the other partially visible. This means I can't hide some HTML used to get a render. This means if I, or others, need to update the render we either don't have the HTML available or I have to clutter the post.


Under what conditions is \begin{equation*}\frac{\left(n^2-1\right)!}{\left(n!\right)^{n}}\end{equation*} an integer? (It turns out, apparently, that the answer is "precisely when $n$ is non-prime and $\neq 4$". I am interested in whether there is a straightforward proof of this.)


why I could use variable before declared in function

in this code snippet, I could not use obj before declaration    const obj = {      value : 10,      x : obj }    while here I could    const obj = {      func : () => console.log(obj.value),      value : 10, } obj.func();    How could the second compiles but the first fail? actually, I wonder why any of them compiles since I used obj before it was instantiated, as I understand (I may be wrong) first the right side first evaluated, and then assign the result to the variable(obj)


Write $\cos\theta-\sqrt{3}\sin\theta$ in the form $r\sin(\theta-\alpha)$

With this question I got   $\cos\alpha=-\sqrt{3}$ and $-r\sin\alpha=1$   thus $r\sin\alpha=-1$. Both of these are negative, so my solution should be in third quadrant. In the answer however, it is in first quadrant and I don't understand why. I got $\alpha= 210^\circ$ but the answer is $\alpha=30^\circ$.


I get some options which I must select to install lubuntu 19   Start Lubuntu Start Lubuntu (safe graphics) OEM install (for manufacturers) Check disc for defects    I'm sorry, I'm new to Linux, watch tutorials but these options don't come out, they use others that don't come to me. Please help


Let $k$ be an integer. Show that   $$\gcd(3k+2,5k+3)=1$$   I know that I can use the Euclidean algorithm, but the $k$ is bugging me. Should I use induction or something?


Making 256-color AND Line drawing characters both work in PuTTY

I'm having trouble setting up PuTTY with Ubuntu.   I'm trying to get line characters to work in aptitude as well as 256-color support, but can only get one or the other.    Ubuntu Config   Using 64-bit Ubuntu Terminal type xterm-256color or putty-256color gives 256-color, but incorrect line characters.  Terminal type linux gives proper lines in aptitude, but only 16 colors.  PuTTY Config   Using font with Unicode characters. (DejaVu Sans Mono) Received Data is assumed to be in UTF-8. Set to use Unicode line drawing code points.    Output from locale:  LANG=en_US.UTF-8 LANGUAGE= LC_CTYPE="en_US.UTF-8" LC_NUMERIC="en_US.UTF-8" LC_TIME="en_US.UTF-8" LC_COLLATE="en_US.UTF-8" LC_MONETARY="en_US.UTF-8" LC_MESSAGES="en_US.UTF-8" LC_PAPER="en_US.UTF-8" LC_NAME="en_US.UTF-8" LC_ADDRESS="en_US.UTF-8" LC_TELEPHONE="en_US.UTF-8" LC_MEASUREMENT="en_US.UTF-8" LC_IDENTIFICATION="en_US.UTF-8" LC_ALL=


Remove automatically added keyboard inputs and prevent them from coming back (Windows 10)

I have 2 languages installed on my computer, both with a single input method.  I have 2 keyboards: CES-CSQ and ENG-US.    However lately (maybe after the last Win10 update) I started to see 2 additional keyboards in my systray  - namely CES-CS and ENG-CSQ.    Is there there a way to remove those 2 input options (CES-CS, ENG-CSQ) which I do not see in the Control panel's Language options?  Solution described at  question does not apply to my problem because I do not see input options that I want remove in Control panel's Language options.


Convexity with setting $ \lambda=\frac{1}{2}$ implies continuity?

I'm not sure if there is already an answer to this particular question, but here it goes,  (Definition of convexity that is used here:  Let $D \subset \mathbb{R}$ be an (infinite or finite) interval. A function $f:D\longrightarrow \mathbb{R}$ is called convex if for any $x_1,x_2 \in D$ and any $\lambda$ with $0<\lambda<1$,  $$f(\lambda x_1+(1-\lambda)x_2)\leq \lambda f(x_1) + (1-\lambda) f(x_2)$$ is valid )   The following was already proven:   In an interval $I \subset S $ continuous function $f:I \longrightarrow \mathbb{R}$  is then convex if and only if   $(1)$ $$f\bigg(\frac{x+y}{2}\bigg)\leq\frac{f(x)+f(y)}{2} $$ for any $x,y \in I$.  In the proof, the ( -> ) part is almost direct by setting $\lambda=\frac{1}{2}$ into the definition of convexity. But as for ( <- ) I had to use the continuous property of the function, but I wonder if the property $(1)$ stated above actually implies continuity so that the theorem above doesn't need to state the continuity property, as of:   In an interval $I \subset S $ function $f:I \longrightarrow \mathbb{R}$  is then convex if and only if   $(1)$ $$f\bigg(\frac{x+y}{2}\bigg)\leq\frac{f(x)+f(y)}{2} $$ for any $x,y \in I$.  I tried also to find counterexamples but to no avail, as it is for me rather intuitive that the property $(1)$ should imply continuity but I'm not sure, maybe the proof can be similar to the proof of "convexity implies continuity". I would love to see some counterexamples (assuming they exist) or perhaps the proof. Thank you very much in advance!


Apps updated, now I get an unknown lock screen with ads

After finally doing a bunch of updates, suddenly every now and then some random lock screen with ads showed.    Which app is causing this?


I have a multi-paragraph section of tiny-font within a larger document of normal-size text.  The last paragraph within this section seems to get double spacing:    I can fix the problem by putting a blank line before the final \end{tiny} but I don't know why this works.  Can someone tell me what is going on?  Here is the MWE  \documentclass[11pt,oneside]{report}  \begin{document} This is normal size.  \begin{tiny} This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size. This is tiny size.   Why is this paragraph double spaced?  Why is this paragraph double spaced?  Why is this paragraph double spaced?  Why is this paragraph double spaced?  Why is this paragraph double spaced?  Why is this paragraph double spaced?  Why is this paragraph double spaced? \end{tiny}  \end{document}


Migration to version 2016 from versions 2000, 2005, 2008, and 2012

I just accepted a position that has multiple versions of SQL Server, from what I was told during my interview, it ranges from versions 2000 - 2012, the main goal is to centralized these databases to the 2016 version so we can get rid of the Linked Servers and the users would just point to the 2016 instance.    All of these versions have identical databases, logins, etc, for the most part, but there are slight object differences that need to be evaluated.  Most importantly, the data date on these versions are different, for instance, for SQL Server 2000, it contains data up to year 2005.  For SQL Server 2005, it contains data up to 2007, and so on.  The upgrade/migration experience I have are from SQL Server 2008 R2 to SQL Server 2012 which included Always On, but steps should be similar, and btw, this was a team effort.  You cannot upgrade from SQL Server 2000 to SQL Server 2012 as it requires an intermediate step.  I would like to approach it this way as this requires    Upgrade SQL Server 2000 to SQL Server 2008 R2 Upgrade SQL Server 2005 to SQL Server 2008 R2   or this can be upgraded directly to  SQL Server 2012   Upgrade SQL Server 2008 R2 to SQL Server 2012 Upgrade SQL Server 2012 to SQL Server 2016   There are a lot of documents out there but would you know of a good set of documents/whitepaper that includes the details step by step?  From what I mentioned above, would you approach it differently?    Please let me know your thoughts as I know this is tedious work since the versions accumulated.  Also, this is a side-by-side upgrade, thank God!


I thought you should never use triangles?

I was curious on looking to how does an anime topology look like. I've looked into pictures and videos and I thought the best way to learn took into it is to see it for myself. So I used ninja ripper to rip a model from Fate/EXTELLA (cause it's the only game in my machine for now). Her name is Tamamo:  Why does it have triangles here? I thought we should only use Quads?


I'm remove opportunity, case related list from contact layout. After remove I try to pull using sfdx:force:source:pull -u . But, unfortunately I got an error . ERROR running force:source:pull:  Entity of type 'CustomApplication' named 'Contact' cannot be found.


If $X,Y$ are equivalence relations, so is $X \times Y$

If $X,Y$ are reflexive, symmetric, and transitive, then $X \times Y$ is an equivalence relation where ${(a,b):a\in X, b\in Y}$.    I am trying to self learn these topics. I do know what an equivalence relation is. I wanted to know how would someone prove that $X\times Y$ be an equivalence relation?


I know there was a lot of questions about this, but my problem is kind of different.  I have a tablet with Android. On Windows I used to host wifi from my PC. I used an application called connectify. On Ubuntu. I can use the "Use as hotspot" option but it hosts "Ad-hoc" network. Android doesn't see ad-hoc networks.  How can I make a wifi network similar to what connectify did?   My PC is connected to Internet using a cable and I have external adapter.  Sorry for my english, and thanks for the help :)


Searching multiple sub strings with special character as marker

I have a string like :   myStr = "abcd123[ 45][12] cd [67]"   I want to fetch all the sub-strings between '[' and ']' markers. I am using findall to fetch the same but all i get is everything between firsr '[' and ']' last character.  print re.findall('\[(.+)\]', myStr)   What wrong am i doing here ?


I am stuck at "not defined" but it looks defined to me

i am stuck. I dont know where i went wrong. def convert_distance(miles):     km = miles * 1.6  # approximately 1.6 km in 1 mile  my_trip_miles = 55  my_trip_km = km * my_trip_miles  print("The distance in kilometers is " + str(my_trip_km))  round_trip= my_trip_km * 2  print("The round-trip in kilometers is " + str(round_trip))  I keep getting "km" is not defined.


Windows console with ANSI colors handling

Is there any console emulator for Windows that interprets ANSI coloring?   We use rspec and a part of our team use Windows and the special string for coloring are not very useful for them ;).


I currently have a "friend" that has an account on my dedicated server which is running Ubuntu. Not getting into specifics, but he said he will use ~2gb max and he's using ~10gb. On to the question. Is there a way to limit his account to a maximum of say.. 3gb? Killing the process(es) would be fine too.  I've done some googling but still not found a solution :/


Does Class need to implement IEnumerable to use Foreach

This is in C#, I have a class that I am using from some else's DLL. It does not implement IEnumerable but has 2 methods that pass back a IEnumerator. Is there a way I can use a foreach loop on these. The class I am using is sealed.


How do i get those 52 packeges updated?  i give a sudo apt-get update but still it all remains.  Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.4.0-138-generic x86_64)   * Documentation:  https://help.ubuntu.com  * Management:     https://landscape.canonical.com  * Support:        https://ubuntu.com/advantage    Get cloud support with Ubuntu Advantage Cloud Guest:     http://www.ubuntu.com/business/services/cloud  52 packages can be updated. 9 updates are security updates.


Suppose that $f$ is an entire function and that there is a nonempty open ball $B(w_0,r)$ such that $w\notin \mathrm{Range}(f)$ for all $w\in B(w_0,r)$. Show that $f$ is constant.    I'm not sure how to start this. This looks like maybe something to do with Liouville's Theorem, but this is under a topic where we try not to apply other theorems, so I'm not sure if I can use it here if it's even possible.


How much clearance should you include in through-hole component holes?

Is there a general rule as to how much clearance you should add to through-hole components' holes to allow them to fit easily?  For example, if I have a component with 1mm pin diameter, what should the diameter of the holes for it's pads be?   Using my calipers on a PCB I have handy, it looks like about 0.1mm is added to some holes, but I don't know if that's "normal" or not.


E: Sub-process /usr/bin/dpkg returned an error code (1) problem with dpkg?

I wanted to install arm-none-eabi-gcc and I have encountered the above error. I know that the problem is generic and I need to read lines above that message but after analyzing error lines I still do not know what to do to solve that issue. Here are error lines maybe anyone would be able to help me.   Unpacking gdb-arm-none-eabi (7.6.50.20131218-0ubuntu1+1) ... dpkg: error processing archive /var/cache/apt/archives/gdb-arm-none-eabi_7.6.50.20131218-0ubuntu1+1_i386.deb (--unpack):  trying to overwrite '/usr/share/man/man1/gdb.1.gz', which is also in package gdb 7.7.1-0ubuntu5~14.04.2 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Errors were encountered while processing:  /var/cache/apt/archives/gdb-arm-none-eabi_7.6.50.20131218-0ubuntu1+1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)


So once I FaceTimed one of my friends, but this random dude answered

So once I tried to face time my friend, but when it connected it was a random dude that I have never met. This has happend to me three times now. Each time it is a different guy. Help, I don't know if it is my account or hers.


Hello people here is my code below...              #ajax code after success             $.each(obj,function(index,Object) {                 ban_list += '
remove ban
';              })          $('.b_list').html(ban_list).toString();   above code works fine by creating a div with the class=ban_n and id=get1_name get1_name is nothing but Object.To now i have to set onclick for ban_n  $('.ban_n').on('click',function(){ console.log($(this).attr('id')); })   why is the above code does not work.. anyway to fix this??


Installation ERROR(14.04): serious errors were found while checking the disk for /

Everytime when I try to install Ubuntu 14.04 there is a message saying there are serious errors while checking for drive /. It also says some files are not ready yet or no present.  I have tried Ubuntu 13 and that doesn't work too but Ubuntu 12 works. What can I do?


When opting out the Winter Bash the top bar popup related to snowflake looks like this for me:    Is it intentional that there are no horizontal margins for popup content?


How to calculate automatically the number of pages

When I create a page in latex, below everything appears the nº of page: 1 , 2 ...  Its possible to show  the page number above the total page?  For example:   \documentclass[11pt,a4paper]{article}  \begin{document}   Hi % page 1  \newpage  Hi2 % page 2  \end{document}     Thanks.


KVO Notifications for a Modification of an NSArray backed by a NSMutableArray

I am trying to use KVO to listen to collection change events on an NSArray property. Publicly, the property is a readonly NSArray, but is backed by an NSMutableArray ivar so that I can modify the collection.  I know I can set the property to a new value to get a “set” change, but I’m interested in add, remove, replace changes. How do I correctly notify these type of changes for an NSArray?  @interface Model : NSObject  @property (nonatomic, readonly) NSArray *items;  @end  @implementation Model {     NSMutableArray *_items; }  - (NSArray *)items {     return [_items copy]; }  - (void)addItem:(Item *)item {   [_items addObject:item]; }  @end     Model *model = [[Model alloc] init];  [observer addObserver:model        forKeyPath:@"items"           options:(NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld)           context:NULL];  Item *item = [[Item alloc] init]; [model addItem:newItem];   Observer class:  -(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {     if ([keyPath isEqualToString:@"items"]) {         //Not called     } }


Why is Linux reporting "free" memory strangely?

This is a  about how Unix operating systems report memory usage.   Similar Questions:                    I have production server that is running Debian 6.0.6 Squeeze  #uname -a  Linux debsrv 2.6.32-5-xen-amd64 #1 SMP Sun Sep 23 13:49:30 UTC 2012 x86_64 GNU/Linux   Every day cron executes backup script as root:  #crontab -e  0 5 * * * /root/sites_backup.sh > /dev/null 2>&1   #nano /root/sites_backup.sh  #!/bin/bash str=`date +%Y-%m-%d-%H-%M-%S` tar pzcf /home/backups/sites/mysite-$str.tar.gz /var/sites/mysite/public_html/www mysqldump -u mysite -pmypass mysite | gzip -9 > /home/backups/sites/mysite-$str.sql.gz cd /home/backups/sites/ sha512sum mysite-$str* > /home/backups/sites/mysite-$str.tar.gz.DIGESTS cd ~   Everything works perfectly, but I notice that Munin's memory graph shows increase of cache and buffers after backup.  Then I just download backup files and delete them. After deletion Munin's memory graph returns cache and buffers to the state that was before backup.  Here's Munin graph:  Externally hosted image was a dead link.


Why finite structures are uniquely characterized?

Somewhere I read that finite structures can be uniquely described (up to an isomorphism) using a sentence which is a conjunction of all atomic formulas, and their negation, and an another sentence that asserts the finiteness of the structure. Why this is true? How to prove it? What changes when the structure becomes of infinite cardinality?


Conceptually speaking, why does synchrotron radiation arise?

First, a bit of background. I'm a chemist who works with synchrotron-based techniques, but I'm focussed on materials analysis rather than synchrotron physics.  I'm struggling to work out where synchrotron radiation (SR) actually comes from. Why does subjecting an electron to radial acceleration cause it to emit photons? I understand, with Bremsstrahlung radiation that the energy from the decelerating particle has to go somewhere. My first thought was that SR may arise from a similar effect, as my understanding is that you do work when you radially accelerate a particle. I reasoned that, since the magnitude of its velocity remains constant, and the magnitude of the kinetic energy (KE) remains constant, SR must result from conservation of energy (i.e. the work done in the radial acceleration is converted into SR). However, I've since read that emission of SR causes the electrons in the storage ring to lose energy. And, this energy must be resupplied by the inclusion of RF cavities in the ring. This would suggest that SR comes from the KE of the electron, not from the work of the magnet on the electron. (On reflection, I can't see how a permanent magnet could "do work".)  So why is SR emitted?  (Please bear in mind, that as a chemist, I have next to no knowledge of relativity, electrodynamics, Maxwell's equations, etc. I'm really just looking for a conceptual understanding. I don't mind a mathematical answer if you can give one without assuming knowledge of such physics. But, I imagine that's unlikely.)  Edit: Any good textbook recommendations would be helpful too. All the books I've read either gloss over the issue or use physics that goes over my head.


E: Package 'git' has no installation candidate, how to resolve?

I am facing below issue while installation time of git sudo apt-get install git Reading package lists... Done Building dependency tree        Reading state information... Done Package git is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'git' has no installation candidate  Note: I have uninstall and trying to install again. Below is the output of sudo apt update Hit:1 http://ppa.launchpad.net/gezakovacs/ppa/ubuntu xenial InRelease Hit:2 https://download.docker.com/linux/ubuntu xenial InRelease                Hit:3 http://ppa.launchpad.net/maarten-baert/simplescreenrecorder/ubuntu xenial InRelease Hit:4 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu xenial InRelease    Reading package lists... Done Building dependency tree        Reading state information... Done All packages are up to date.


What is "==" in Java ? Why can i only compare numerical data type with it and characters can be compared. But not the string data types. What does it provide when i compare two strings?


So, I don't like proofs.  To me building a proof feels like constructing a steel trap out of arguments to make true what you're trying to assert.  Oftentimes the proof in the book is something that I get if I study, but hard to come up with on my own.  In other words I can't make steel traps, but I feel fine buying them from others.  How does one acquire the ability to create steel traps with fluency and ease?  Are there any particular reference books that you found helped you really get how to construct a proof fluently?  Or is it just practice?


So I am delt with a very bad hand. As Windows user for nearly 10 years  I have an assignment which says  Create 7 users - 2 admin, 2 teachers and 3 students [DONE]  Create folder in Home - Admin Files,Teacher Files,Student Files [Done]  Now I have to be able to do this using terminal   Allow students read-only access to the files in the Student Files folder, and no access to the other folders. Allow teachers full access to all  files except the Admin Files folder, to which they have no access. Allow administrators full access to all files.   How do I change the file permission for the scenario above?  Thanks in Advance


Doing PhD in math/physics after obtaining a bachelor degree in an unrelated field

I want to do a PhD in mathematics (Specializing in algebraic topology or algebraic geometry ) or mathematical physics (String theory). I have a bachelor degree in a totally different field (medicine).  Here's my situation :  I have independently studied mathematics and physics. I have spent a lot of time with hatcher's textbook in algebraic topology and lang's complex analysis among with other topics in math and physics. These are proof-heavy textbooks and I usually do the exercises.   Now , after having studied analysis ,differential topology ,geometry, abstract algebra , quantum mechanics and QFT .  Is this a good preparation for a PhD in math/physics ?   Please note that I have studied from standard textbooks and solved a lot of exercises.   How do I convince PhD committee to accept my application ?   If I apply now , Apart from formal qualifications,my application will be missing one crucial component which is the letters of recommendations. I'm not sure where do I get them ? I don't know any physics or math professors who can evaluate my knowledge.


Like so many others, I am working at home and trying to make my space more comfortable. I have a work-issued Windows laptop and am wondering if there is a way to use my 2018 iMac as a larger monitor. From what I have been reading it seems like "no", but I am hoping someone on here as a suggestion. My neck is killing me!


Conflicting who/whom usage rules in a sentence

Consider the sentence "Please gather information on who can serve as a proctor."  The he/him, she/her test gives conflicting answers here: One would say "Please gather information on her", but "He can serve as a proctor," and the entire sentence can't be accurately replaced with such a pronoun.   Which rule should be used? I know 'who' is acceptable regardless in colloquial English, but would it be valid to use 'whom' as well in this scenario?


I have table with this structure :   IdCity      int  CityName    nvarchar(20)   the data inside it is written in russian like :   +--------+----------------+ | IdCity |    CityName    | +--------+----------------+ |      1 |    Абакан      | |      2 |    Азов        | |      3 |    Александров | |      4 |    Алексин     | +--------+----------------+   I tried to make an easy view to retrieve the rows that have city name = Азов :   SELECT       IdCity, CityName FROM            dbo.City WHERE        (CityName = 'Азов')   It gave me null although the record is in the table.  When I tried to add a row with an english name:cityname = abc, for example and edited the view to select cityname = 'abc', it worked fine.  so how to make the sql query select the russian inputs also?


Java Runnable jar with imageview doesn't show GUI

I am trying to make my project a runnable jar but the problem is that the gui is not showing up. From the error in my cmd i tell it is something about my imageviews.  My project contains imageviews which are located in another folder than the sourcefoler. I have set the buildpath, but it still doesn't seem to work  This is where I add the images to the GUI:  String path = "./imageTest/";         File folder = new File(path);         File[] listOfFiles = folder.listFiles();         for (File file : listOfFiles) { <----- Line 51             ImageView imageView;             imageView = createImageView(file);             tile.getChildren().addAll(imageView);         }   The folder imageTest is added as a sourcefolder in the buildpath  This is the error I get when running the jar through cmd:  "Exception in Application start method Exception in thread "main" java.lang.reflect.InvocationTargetException         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)         at java.lang.reflect.Method.invoke(Unknown Source)         at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58) Caused by: java.lang.RuntimeException: Exception in Application start method         at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)         at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$155(LauncherImpl.java:182)         at java.lang.Thread.run(Unknown Source) Caused by: java.lang.NullPointerException         at application.guifx.MainScreen.mainScene(MainScreen.java:51)         at application.guifx.MainApp.start(MainApp.java:37)         at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)         at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)         at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)         at java.security.AccessController.doPrivileged(Native Method)         at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)         at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)         at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)         at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)         ... 1 more"   This is the MainApp  public class MainApp extends Application {     private Service service;     private Stage stage;     private ScrollPane root = new ScrollPane();      private MainScreen mainScreen;       public MainApp() {         service = Service.getService();         StorageInitializer.initStorage();      }      @Override     public void start(Stage primaryStage) throws Exception {         service = Service.getService();          stage = primaryStage;          mainScreen = new MainScreen(stage);          stage.setWidth(100);         stage.setHeight(100);          primaryStage.setWidth(1000);         primaryStage.setHeight(850);          Scene scene = mainScreen.mainScene();<----- Line 37          primaryStage.setScene(scene);         primaryStage.show();     }      public static void main(String[] args) {         launch(args);      }  }   To be clear... The program works when laucnhing through eclipse, but doesn't when I make it a runnable jar This is how the system looks when opening it from eclipse


How to update ntpd to the latest version to patch the latest vulnerability?

This week  on the Network Time Protocol Daemon (ntpd) was demonstrated, . This could potentially wreak havoc with my HTTPS website or other time sensitive services I am running.  According to the article, to remain safe, clients and servers alike should run at least NTP version 4.2.8p4.  Running ntpd --version on my Ubuntu Server 14.04.3 LTS machine gives me ntpd 4.2.6p5 which is still vulnerable. This is even after running apt-get update, apt-get upgrade and apt-get dist-upgrade.  Apparently I can download the latest version from ntp.org myself. But I am unsure if this will conflict with my existing ntpd install done via apt-get. Also they only offer the download via HTTP and their method of ensuring authenticity is by using an MD5 hash checksum... I am looking forward to my NSA backdoored patch. I really wish people would use GPG signatures.   Does Ubuntu plan to release a security patch to upgrade ntpd to 4.2.8p4 any time soon? What will be needed to get the fix? If I read the code and assumed the 4.2.8p4 version available for download on the ntp.org website was trustworthy, how can I install that without conflicts?


Is it possible that the particles can be brought by some external agency without changing the kinetic energy?

I am a student and I've been studying a physics book. There is one statement in the solution of one question (regarding calculation of Potential energy) which is confusing me. It states that:     If the particles are brought by some external agency without changing the kinetic energy, the work done by the external agency is equal    to the change in potential energy = - 1.0 x 10 -11 J.   Now I want to know how is it possible to bring or move a particle without changing its kinetic energy because in bringing a particle there is some change in the velocity which should change the Kinetic energy?


I am trying to add multiple footnotes in the chapter title but only one of them appears on the bottom of the page. \documentclass[12pt]{report}  \usepackage{tamuconfig} \usepackage{dcolumn}% Align table columns on decimal point     \usepackage{amssymb}% Package to draw a square in the formulas     \usepackage{wasysym}% Package to draw a square in the figures \usepackage{amsmath} % or simply amstext \usepackage{color} \usepackage{mhchem} \usepackage{chemformula} \usepackage{tabularx} % in the preamble \usepackage{longtable} \usepackage{siunitx} \usepackage[numbers]{natbib} \usepackage{booktabs} \usepackage{filecontents} \usepackage[multiple]{footmisc} \usepackage{caption} \usepackage{subcaption} \usepackage[hidelinks]{hyperref} \usepackage[multiple,symbol]{footmisc} \renewcommand{\thefootnote}{\fnsymbol{footnote}} \textheight=80pt% only for the example  \begin{document}  \chapter[nine]{SUMMARY AND CONCLUSIONS\footnote{one}\footnote{two}}  \end{document}  In my tamuconfig.sty file I have a line of code as     \usepackage[rm, tiny, center, compact]{titlesec}  I think that is what messes up with footnote. I appreciate it if anybody knows how can I fix this problem.


Taylor serie of exponential function is not uniformly convergent on R+

Let $E_n(x)=1+x+(x^2/2!)+...+(x^n/n!)$   I'm asked to prove that this function is not uniformly convergent on $\mathbb{R^+}$   I really don't know how to start here, if anyone could give me a hint it would be greatly appreciated.


Can I find the axis of rotation for any single-qubit gate?

Suppose I have an arbitrary qiskit $U_3$ gate: $U_3(\theta,\phi,\lambda)$. Is there a way I can find which axis the gate is rotating around? In other words, given any real numbers $\theta,\phi,\lambda$, can I find the vector $\hat n = (n_x,n_y,n_z)$ that the gate corresponds to, so that I can plot the axis of rotation on the Bloch sphere? I'm thinking about the y-z decomposition, but I'm still unable to find out the elements of $\hat n$. How can I figure that out? Thanks a lot for the help:)


About an hour ago I received a series of upvotes. All on different, unrelated questions and answers, all within a few minutes window. This obviously raised a red flag.  Should I do anything with this or just wait for Community user to sort it out?


Null pointer exception for Guessing game

Hey guys I am sure there is something obvious here that im just not seeing. I need some help with trying to figure out why I am getting a null pointer exception when I set the game.max value in the GuessingGame3 constructor. It seems like no matter what I do the value will not get set. Even when I explicitly set the value it still throws an error. I've tried changing the max variable to static as well and that didnt work either. A lot of people are saying you need to initialize the value which I did and that didnt work. Please help.     package guessinggame3;    import java.util.Random;    //provides methods that return a random integer in                              //the range 0 to 4294967296.    import java.util.Scanner;   //enable the user to input values from the keyboard     public class GuessingGame3     {        public int max;        public int answer;        public int maxGuessesAllowed;        public int numGuessTaken;        public static int currentGuess;        public static int previousGuess;        public boolean gameOver;        public int differential;        public GuessingGame3 game;  public static void main(String[] args) {      GuessingGame3 game = new GuessingGame3();     game.GuessingGame3(); }  public void GuessingGame3() {     Scanner sc = new Scanner(System.in);     System.out.println("Welcome to the Guessing Game.");     System.out.println("Enter the maximum number:");      game.max = sc.nextInt();              // input maximun number of guesses     Random generator;      // New random number generator     generator = new Random();     game.answer = generator.nextInt(game.max); // the randomly chosen answer     System.out.println("Enter the maximum number of guesses allowed:");      maxGuessesAllowed = sc.nextInt();      game.newGame(maxGuessesAllowed); }  public void newGame(int GuessesAllowed) // Given the max,generate answer {  game.maxGuessesAllowed = GuessesAllowed;  Random generator = new Random();     // New random number generator  int answer = generator.nextInt(max); // the randomly chosen answer  System.out.println("The answer is:" + answer);  game.gameOver = false;  game.differential = game.max;  game.numGuessTaken = 0;  game.guess(); }    public void guess()  {   /* Takes in int answer & returns string response */             Scanner sc = new Scanner(System.in);  while(!gameOver)  {   System.out.println("Enter your guess:");    currentGuess = sc.nextInt();   if(answer == currentGuess)     // correct guess branch    {     gameOver = true;     System.out.println("Congratulations! Would you like to play again?");     System.out.println("Enter Y for yes or N for no.");     String again = sc.next();          again = again.toUpperCase();       if(again.equals("Y"))       {        GuessingGame3 game;        game = new GuessingGame3();        game.GuessingGame3(); //Start a new game       }       if(again.equals("N"))       {        System.out.println("Goodbye.");        break;       }    }         if(currentGuess > answer)      //currentGuess is too high      {       System.out.println("Too high");      }      if(currentGuess <answer)       //currentGuess is too low      {       System.out.println("Too low");      }      if(currentGuess > max)         //currentGuess is beyond the max      {       System.out.print("Your guess is beyond the max you set.");       continue;      }      int differential = Math.abs(answer - currentGuess);      if (game.differential != 0 && differential < game.differential)         {                                       // If this is the first guess                System.out.println("Getting Warmer");  // there is differential. So no      }                                       // "warmer" or "colder."      if (game.differential != 0 && differential > game.differential)      {       System.out.println("Getting Colder");         }      game.differential = differential;  } }   }


The Help Center claims that moderators have no abilities

Screenshot (click to enlarge):    I was browsing the Help Center of PPCG when I found this "Moderator Abilities" tab. When I clicked it, .  ... does this mean that moderators no longer have any abilities? Eeeek!


get number of lines of code of a function in python

I have a function in python. Is there a way to get the number of lines of code that the function has in the original source file?  e.g.  # main.py  import f1 from mylib  print(loc(f1)) # 3  # mylib  def f1():   pass   return


Finding all elements in $GL_{2}(F)$ that commute with all other elements in $GL_{2}(F)$

I'm new to group theory.  I'm trying to find which elements of $GL_{2}(F)$ commute with all other elements of $GL_{2}(F)$. I have proved that all diagonal matrices as following $\begin{pmatrix}a & 0\\ 0 & a \end{pmatrix}$, are commute with all other elements in  $GL_{2}(F)$. But how can I prove that there are no other elements that fulfill the condition?


Prove or disprove if bijectivity is kept after set difference with a countable set

I ran into some claims of my own while doing an exercise that I would like to be true for my solution to be correct. Are the following true or false, how to prove or disprove it?  Let $ \varphi : \mathbb{N} \setminus I \rightarrow \mathbb{N} $ with  $I \subseteq\mathbb{N}$,   is it bijective ?  I know it holds for I finite, because by Dedekind's criterion there exist a bijection between an infinite set and some proper subset. But I am not sure if I can say the same for I infinite, because what if for example I is $\mathbb{N} \setminus \{1\}$,then the domain of $\varphi$ would be just $\{1\}$, wouldn't it? and $\varphi$ wouldn't be a bijection . But it might as well be just an ilusion like when one thinks even numbers are half of natural numbers, and then it turns out they are equinumerous 2) If $ \psi : Z  \rightarrow \mathbb{N} $ is a bijection,with $Z$ a subset of $\mathbb{N}$, then $ \psi : Z\setminus I  \rightarrow \mathbb{N}\setminus I$ is also a bijection, $I \subseteq\mathbb{N}$ Same kind of doubt here if I is infinite, but also I guess I have to consider two cases: $I \cap Z \neq\phi$ and $I \cap Z =\phi$


Why fixed design analysis for observational data

Why do we use a fixed design analysis of regression coefficients, even for observational data, where the design is not fixed?  For instance: $Var[\hat \beta]=(X'X)^{-1}\sigma^2$ is conditional on $X$. Since $X$ is random in observational studies, this is an under estimate of the true $Var[\hat \beta]$.   Edit: As pointed out by @christoph-hanck, $(X'X)^{-1}$ cannot be, by definition, systematically smaller than $\mathbb{E}(X'X)^{-1}$. Question remains: why do we use fixed design standard errors, instead of random design standard errors?


How does a book chapter in an edited volume compare to a peer reviewed paper?

I have been invited to write a book chapter in an edited volume, relating to my field of work. I have a paper ready that I have not published and was planning to submit it soon. So, I am wondering is it worth to use that article for the book chapter, as both are on the same topic, or is it in a sense a waste of a journal paper, as book chapters might not be seen to have the same academic value? What should I do? Should I, instead, send the ready paper to a journal for a review and write a book chapter, based on a couple papers I have published, for instance?  Generally speaking, where does a book chapter stand? Is it something between a conference paper and a full-fledged journal article? Or, does does it have the same value as either of the above-mentioned publication types, in your opinion?


I'm not sure if I'm doing this correctly, but the way I have my server set up now is the user send a POST request to /api/login with their username and password. If it's correct, the server send back a JsonWebToken and the client stores it in localStorage by doing localStorage.setItem('auth', token)  Now my question is how do I get the client to send that token to the server every time they go to a new page on the site?   Eg say in the HTML I have  Home    How do I sent the token when they click that link so the server can validate the user and load the appropriate HTML? I'm using NodeJS and Express


How to disable Utility Manager (Windows Key + U)

How do I disable the Windows + U hotkey in Windows XP? Alternatively, how do I stop the utility manager from being active? The two are related. The utilty manager is currently providing a potential security hole and I need to remove it[1]. The system I'm developing uses a custom Gina to log in and start a custom shell. This removes most Windows Key hotkeys but the Win + U still pops up the manager app.  Update:  Things I've tried and don't work:   NoWinKeys registry setting - this only affects explorer hotkeys; Renaming utilman.exe - program reappears next login; Third party software - not really an option, these machines are audited by the clients and additional, third party software would be unlikely to be accepted.   Also, the proedure needs to be reasonably straightforward - this has to be done by field service engineers to existing machines (machines currently in Russia, Holland, France, Spain, Ireland and USA).  [1] The hole is via the internet options in the help viewer the utility app links to.


Is it possible to use a mini USB Bluetooth dongle like in the following picture in order to improve my , so it can comunicate with other Bluetooth devices?    If it is, how can I do that?


Deriving a formula for the number of ways to partition a set

I'm working on a question below:     Let $H(n,k)$ denote the number of ways to partition a set with $n$ elements into $k$ subsets of the same size. Derive a formula for $H(n,k)$.   Thanks in advance for any hints! :D


Can bounties be awarded multiple times by the same person on the same question?

Is there any restriction to prevent multiple bounties ( not simultaneously) being awarded to different answers on the same question ?  i.e., on a question  -  I want to set multiple bounties since I've received 2 awesome answers. Can I set award a bounty on answer A first, and then set the bounty and award it to answer B ?


In calculating the standard deviation, why do we square the difference from the mean, as opposed to cubing?

This question has been bothering me for a while: In calculating the standard deviation, why do we square the difference from the mean, as opposed to cubing the differences (and then taking the cube root at the end)? Is this just a random choice, since eventually you have to choose some exponent, and "2" was sufficient? Or is there a deeper mathematical reason?  Thanks in advance!


Is there a point where harddrive age (Power On Hours) necessitates replacement?

I have several storage arrays where a significant number of the drives have been powered on between 25,000 - 30,000 hours (2.8 - 3.4 years). These drives have no other issues or errors.   What I want to know: is there a point where drive age alone is a significant enough factor to replace a drive, even if the drive is working fine and has no errors?    (I'm curious to see if people tend to run drives until they fail or start throwing errors, or if anyone takes a proactive approach at replacement using Power On Hours as a metric.)  Drive manufactures generally quote MTBF on enterprise drives at 1,000,000 to 1,500,000 hours, but these numbers don't really mean much in the real world.  I did locate this study completed in 2007:  Disk failures in the real world: What does an MTTF of 1,000,000 hours mean to you?    The study suggests a "sweet spot" between 1 year and 5-7 years where you can expect less failures. Drive age before/after these times tended to be considerably higher.


How to restore Win10 TaskView UI to how it was before the April update?

The latest win10 update introduced a timeline in the task view. It's possible to disable this, which I did, but I am still annoyed by the new UI.  How can I a) completely revert to the old UI without having to undo the update and permanently stop installing updates?    or    b) at least move the desktops previews back to the bottom of the taskView Screen instead of the top, where it is now?  There's no reason for this question, apart from the fact that I like the old UI way better and am annoyed that Windows did not ask for permission before changing such a thing.  To be clear, an image where the desktop previews are where I want them ():   Note that this is not a duplicate of , because I am not asking about how to disable the timeline. As mentioned, I have already done that. My taskView screen now looks like this:  Note that the miniature desktops are at the top and I have to scroll to see all open windows, which I did not need to do before the update.


I need to use a JavaScript patch in my Google Sites, but the problem is I don't understand how to place them and use it as Google Gadget.  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml">  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Untitled Document</title>          I'm hoping for specific instructions using the JavaScript code I provided since I've found general Google Sites embedding instructions unfathomable. However with specific instructions I will be able to figure out how to use scripts in Google Sites in the future as well.


Chapter title overlap with content (arsclassica)

I am currently writing my thesis using the arsclassica. I have minor problem where the long chapter title will overlap with the content of the chapter.   This is part in classicthesis.sty which I think responsible for the design of the chapter title.       \newcommand\formatchapter[1]{%  \vbox to \ht\strutbox{  \setbox0=\hbox{\chapterNumber\thechapter\hspace{10pt}\vline\ }  \advance\hsize-\wd0 \advance\hsize-10pt\raggedright  \spacedallcaps{#1}\vss}}  \titleformat{\chapter}[hang]     {\normalfont\LARGE\bfseries\sffamily}     {\textcolor{halfgray}{\chapterNumber\thechapter} %change the color for main title    \hspace{10pt}\vline\ }{10pt}  {\formatchapter}


Prove that $\frac{c}{c+1}< \frac{a}{a+1} + \frac{b}{b+1}$

Let $a$, $b$ and $c$ be positive real numbers such that $c < a+b$. Prove that $$\frac{c}{c+1}< \frac{a}{a+1} + \frac{b}{b+1}.$$


Term for neologisms created to distinguish between new and old technologies

For example: book -> paper book, e-book phone -> telephone, smartphone Term to describe the creation/modification of words because of the advent of technology.


I have a file that contains:  [Settings] gtk-theme-name = Arc gtk-icon-theme-name = Luv   I am trying to replace the 3rd line so that "Luv" will say somethig else. I tried with this command:  sed -r "3 s/.*/gtk-icon-theme-name = $SELECTED/" ~/.config/gtk-3.0/settings.ini   However, the output gets shown in my terminal and doesn't actually change the file at all. The variable is set by a previous command, btw (trying to write a script to change gtk3 icons for *box users).  Thanks a ton to whoever helps!


If $C$ commutes with certain matrices $A$ and $B$, why is $C$ a scalar multiple of the identity?

I'm self studying Steven Roman's Advanced Linear Algebra, and this is problem 10 of Chapter 8.      Let $A,B\in M_2(\mathbb{C})$, $A^2=B^3=I$, $ABA=B^{-1}$, but $A\neq I$ and $B\neq I$. If $C\in M_2(\mathbb{C})$ commutes with $A$ and $B$, then $C=rI$ for some $r\in\mathbb{C}$.   Is there a way to solve this without writing out arbitrary matrices and attempting to solve a huge system of equations? The only thing I observe is that $A=A^{-1}$, so $B\sim B^{-1}$, so $B$ and $B^{-1}$ have the same characteristic polynomial. I'm stymied trying to show $C$ is diagonal, let alone a multiple of $I$. Thanks for any ideas.  I should add that I know that the center $Z(M_n(\mathbb{C}))$ consists of scalar multiples of $I$, but I don't see any reason to assume or prove $C$ commutes with everything.


Giving (part of) credit to someone else for an answer

I suggest allowing an answerer (user A) to give part of credit to another user (user B) for their answer. A would specify the amount of credit as percentage (C). B would appear as a co-author of the answer. The reputation bonuses for the upvotes of the answer would be divided between A and B:   A gets 100% - C% B gets C%   This would be used when A used an idea of B to build upon, B made a valuable improvement (edit) of B's answer, and so on. In these cases A would be able to give a proper credit to B.  This feature may also encourage users to improve existing answers by edits or comments and may even reduce the number of redundant answers (people would improve existing answers instead of posting the improvement as a second answer, rendering the existing answer redundant).


Is it possible to project an image into the eye which appears to be on a focal plane above source, and is larger?

Is it possible to project an image into the eye, without wearing glasses or using a projection screen, which:   Appears to be on a focal plane in front of rather than behind the source Appears larger in width/height than the source   The image doesn't need to be truly volumetric, appear when viewing from the side, appear to anyone other than the user, or display true black. Less ambitious than R2D2 :) Goal: take a smartphone-size device out of my pocket, put it on a cafe table, look down and see a floating image larger than the device.  Side view (image only visible to eye, not visible to person to the side):   Example: smartphone with pseudo 3D using eye tracking and parallax:


Using OpenLayers 3 or 2 to add layers from Google Maps and Mapserver?

I am beginner in OpenLayers and am starting with the www.openlayers.org documents, which use OpenLayers 3 to teach the basics of OpenLayers. Now, I would like to add layers from Google Maps and Mapserver, but I can't find that in the documents.  I have found many site related to my questions, but all of them use different syntax that I guess are related to OpenLayers 2.   for a beginner would you recommend ol3 or ol2 ?  if you recommend ol3, where I can find what's new in ol3 syntax?


I can't get IIS to match a URL with a #. Instead It trims the URL at the # /product name to match #1.html ^seeds/([A-Za-z0-9-_ #]+).html/?$  I've tried escaping it, to no avail. Result from IIS is /product name to match Any ideas? N.B. whoever marked my question as answered elsewhere please read my question again.


Are foreign drivers liable to pay fines proportional to their income when committing driving-related violations in Finland?

In Finland, there is a  (päiväsakko/dagsböter/day-fines) where drivers who commit violations on the road (such as speeding) are punished with a fine proportional to their income.  Does this system also apply to foreign non-resident drivers? Or do they pay some fixed amount since it's hard to determine what they earn abroad?


How to post a "Possible duplicate of [QUESTION]" comment?

I often see someone post a comment saying "Possible duplicate of [another question]" and then a dialog shows right under the title of my question asking me if the supplied question has answered mine. How does such a comment work and how do I post one?


Christopher Columbus discovered America and was the Indians' best friend. He helped the Indians win their war against Frederick Douglass and freed the Hebrews from Napoleon…   This is a part from the famous surrealistic speech by Mr. Garrison from the TV series South Park (quoted according the comic version). I would like to ask why "to" is omitted before the verb "win". Does it have dealings with the differences between American English and British English?


Stack Overflow doesn't accept my answers

While posting answers, why doesn't Stack Overflow accept my answers? The message says that answers from this account cannot be accepted.  What can I do so that I can post answers again?


Is there an example of a ring $A$ (with unity) which is isomorphic as unital rings to $A\times A$?  Any such ring can't have invariant basis number so in particular can't be commutative.


Is the word 'neo-scholasticism' capitalized in academic writing, or not? It is lowercase in the Merriam Webster dictionary, but capitalized in the Collins English dictionary. So in a thesis, which would be correct: Option A: neo-scholasticism Option B: Neo-Scholasticism


I was in Solitude doing a bunch of quests, when I completed one and got the wabbajack. I looked it up online and saw what it could do, but I don't know if I can recharge it. How can I recharge the wabbajack?


How to extract extension from filename string in Javascript?

how would i get the File extension of the file in a variable? like if I have a file as 1.txt I need the txt part of it.


Applying for a Schengen visa in another country than my main destination

I'm travelling to Belgium for 3 days in the summer, but my first point of entry would be Germany and the closest embassy I have is the German embassy.  Will the German embassy issue a Schengen visa? Because I wouldn't actually be staying in Germany.


Perceptron trained on time series always predicting the same answer

Using the model from , I'm training a 3-layers perceptron with log returns over a very large dataset (~55,000 points). The output's layer contains two neurons, one for each of the classes (either the returns are + or -) in which I am trying to cluster my inputs (returns for the past n days).   The machine always predicts the same value, ie the output which has the highest probability over the entire dataset. Has anyone faced a similar problem before? How is this even possible?  Inputs: 100d-array of log returns (quasi normally distributed).  Target Output: sign of consecutive log return (1 or 0).


I would like to create an program like a text module in background. With a shortcut like ALT+A I am going to simulate an double click at the current cursor position (to select a word in a third party application) and use sendkeys CTRL + C to copy the text into my clipboard. But sendkeys does not work to copy the selected text to clipboard. Is it possible to realize an application like this?         //Jump to cursor position         SetCursorPos(xpos, ypos);          //Simulate double click         mouse_event(MOUSEEVENTF_LEFTDOWN, xpos, ypos, 0, 0);         mouse_event(MOUSEEVENTF_LEFTUP, xpos, ypos, 0, 0);         Thread.Sleep(50);         mouse_event(MOUSEEVENTF_LEFTDOWN, xpos, ypos, 0, 0);         mouse_event(MOUSEEVENTF_LEFTUP, xpos, ypos, 0, 0);          //Copy to clipboard         SendKeys.SendWait("^C");                  //Show Clipboard Text         MessageBox.Show(Clipboard.GetText());  Thanks in advance.


How can I rewire a light to use three-way switches?

I have a light that is operated by two switches. One is upstairs, and the other is down stairs. How can I make the light work by either switch? Currently if I turn the light on down stairs, I cannot turn it off upstairs.   Please advise.


Import tax for used TV in Indian airports

Hi I am planning to take my used LED TV 40" from Riyadh to India so do I need to pay taxes at Indian airport for the old TV also? It's almost 10 months old, and I have the bill for it.


My baby girl has completed 5 months yesterday. She doesn't have good head control. And I am worried. When I lift her in my arms, she does not control her head and leans backward from waist. Plz to reply for this:-)


Align math with the items of an enumerate environment

I have some math in an enumerate environment but as you can see in the picture the equations are below the numbers and not aligned horizontally. Why is that and how can I align them?    MWE  \documentclass{article}  \usepackage{amsmath}  \begin{document}  \begin{enumerate}  \item  \begin{equation*}     \sum_{m=0}^{n}a = (n+1)\cdot a \end{equation*}  \item  \begin{align*}     & \delta(n)\ast \delta{n} = \delta(n)\\     & \delta(n) \ast x(n)=x(n) \end{align*}  \end{enumerate}  \end{document}


I am doing Andew Ng's Deep Learning course and he says that ReLU is better than Sigmoid, but it makes no sense to me at all. The biggest advantage of activation functions are too get a non-linear function that means that cascading is non-linear and when stacking layers, we can learn non-linear functions. But I can't understand why ReLU is anybetter since it is still a straight line. Just two straight lines. The function is discontinous at zero too from what I understand? It just makes no sense to me why ReLU would be a good function. Edit: Nothing about ReLU makes sense to me. It is two straight lines made worse by one value being forced to zero and I cannot understand why we'd want to force $g(z)=0  \forall z<0$. I can't see how this is any better than $g(z)=z$


Proving $\mathbb{F}_p/\langle f(x)\rangle$ with $f(x)$ irreducible of degree $n$ is a field with $p^n$ elements

I am attempting to prove what the title says, that $\mathbb{F}_p/\langle f(x)\rangle$ with $f(x)$ irreducible of degree $n$ is a field with $p^n$ elements.  I have already proven that for any field $K$ and polynomial $f(x)$ in $K[x]$, $K[x]/\langle f(x)\rangle$ is a field if and only if $f(x)$ is irreducible in $K[x]$. So I know that $\mathbb{F}_p/\langle f(x)\rangle$ is a field for sure. Where I'm lost is figuring out how to know for sure that there are $p^n$ elements. It's fairly clear if $n\in\{ 0 ,1\}$, but I don't think induction is going to help.  I know from a proposition in class that since $F_p = \mathbb{Z}/\langle p\rangle$ and $F_p = \mathbb{Z}/\langle p\rangle$ is an integral domain, $F_p[x] = (\mathbb{Z}/\langle p\rangle)[x] = (\mathbb{Z}[x])/(\langle p\rangle[x])$, but I'm not sure whether or not that's helpful information.


Difference between ''He wishes it didn't...'' and ''He wishes it wouldn't...''

I was teaching first and second conditionals to an intermediate English class the other day, and then we started with 'wish' statements.   We talked about famous people and their wishes. For example: 'Barack Obama wishes the USA didn't have such a high unemployment rate.'  And then we continued with the lesson and I introduced 'wish' statements with would.  My example was 'I wish my daughter would do better at school'.   Then a student asked me what the difference between 'I wish' with 'did' or 'didn't' and 'I wish' with 'would' or 'wouldn't' was.   I said the difference was tense, if I say 'Barack Obama wishes the USA didn't have such a high unemployment rate', it's present tense.  If I say 'Barack Obama wishes the USA wouldn't have such a high unemployment rate.' It's incorrect, I think it would be better if I said : 'Barack Obama wishes the unemployment rate would improve in the USA.' , future tense.   And with the daughter example,'I wish my daughter would do better at school.', means that I hope she will improve in the future, and when I say 'I wish my daughter did better at school.' does that mean right now she is doing badly, and I want it to change today? Or does it mean that I don't think it will change?


I am a PhD student (mid stage) and my work includes the use of mathematics. I try to learn as much as possible. I am facing a problem: I spent enough time on the mathematics required for my research, and according to my research supervisor I am good at understanding proofs, theorems, etc. at an intuitive level, but in writing I still have some work to do. Many times I try to write things and, although I think I am not that so bad, there is still a problem to be resolved.  Question: Is writing in research so very important? I have seen some research papers of some star people whose writing does seems to be very impressive to me (although I may be wrong).  Edit: Please note that I don't consider myself a star: that's why I am asking this question. I am trying my best to improve my writing skills and it has improved to some extent, but to me it appears that I may not get that much better at writing. Let me tell you a story: once during my PhD I worked with a professor other than my supervisor, and then we got some result so he ask me to write a paper. I took 4-5 days write a paper 8-9 pages long, then he told me that I wrote in a cryptic manner. (This happened in my first year.)


PATH setting. Updating TLMGR via Terminal

I'm trying to update tlmgr via Terminal using the .sh file update-tlmgr-latest.sh. When I hit the enter button i get this error:  Verifying archive integrity... All good. Uncompressing TeX Live Manager Updater...................................................................................................................................................................................... ./runme.sh: Cannot find TeX Live root using kpsewhich --var-value=SELFAUTOPARENT. ./runme.sh: Please set your PATH as needed, otherwise it's hopeless. [omurcia@dhcppc1 ~]$ sh /home/omurcia/update-tlmgr-latest.sh  Verifying archive integrity... All good. Uncompressing TeX Live Manager Updater...................................................................................................................................................................................... ./runme.sh: Cannot find TeX Live root using kpsewhich --var-value=SELFAUTOPARENT. ./runme.sh: Please set your PATH as needed, otherwise it's hopeless.   I don't know how to proceed in this case. Any help is welcomed.


Proof using method of contradiction. Use the method of contradiction to prove that √2 is irrational.

Use the method of contradiction to prove that √2 is irrational. I don't understand how to prove that √2 is irrational using this method. And I feel difficult to form the contradiction.


Should we have the ability to accept multiple answers as solutions and rate their quality?

I found that different answers are sometimes answering a question, even different methods are used and the execution speed is varying.  Did you ever think about the ability to accept more than one answer as a solution?  Could the quality of answers be rated with e.g. a quality scale (0: not useful, 10: excellent solution)?


Is "walking gingerly" the first usage of "gingerly"? And why did it come about?

I've heard "gingerly" used to describe walking, running, and maybe a few other verbs that I can't think of right now. Was the term first used to describe walking, and why? The meaning doesn't seem obvious if you haven't heard it before.