I have looked for a solution for some time but not having found any similar case, I'll post it here.   I'm using the latex package pgfgantt to create some gantt charts. It works very well in my pc (both Linux and Windows). But I use overleaf to share my documents and it never compiles there with several errors. The solution I've been using for now is to generate static images for the gantts and import then import them as images but it's a tedious task I do not feel like doing everytime I edit the gantts.  Not sure if it's valid to post links to code, here is a small example:   From among the many errors I get, it appears their version doesn't like some of the options for the ganttchart (expand chart=\textwidth and time slot unit=month).  I'm guessing the problem is a different version of pgfgantt?  Is there a way to workaround it in a smarter way than what I've been doing? or, even better, to solve this issue?  Thanks!  Franco

I am trying to use the \ganttvrule macro from pgfgantt as suggested by Torbjørn T. in response to , but with no success. This is his MWE:   \documentclass[border=5mm]{standalone} \usepackage{pgfgantt} \begin{document} \begin{ganttchart}[   vgrid,   hgrid,   vrule/.style={very thick, blue},   vrule label font=\bfseries ]{1}{8} \gantttitle{2018}{8} \\ \ganttbar{}{1}{2} \\ \ganttbar{}{4}{8}  \ganttvrule{day x}{2}  \ganttvrule[   vrule/.append style={red, thin},   vrule offset=.2,   vrule label node/.append style={anchor=north west}   ]{day z}{6} \end{ganttchart}  \end{document}   This should produce the following:   But I get:    I have also tried to incorporate \ganttvrule in my own code, but with similar results.  I am using Overleaf which complains that this is an "undefined control sequence". (Overleaf also complains about the key \bfseries.)  If there are no coding errors the only thing that comes to mind is that Overleaf is not using the latest version of pgfgantt. I have not tried the code in any other editor.


What will happen if, for example, power goes down during package install(I mean unpacking, not dowloading).  Should I avoid such kind of situations or them make no harm, because package database is in consistent state and package could be installed again? Thanks.

Let's suppose I ssh into my computer and run  sudo apt-get dist-upgrade   and, while apt-get is running and installing the packages, another person who is sitting at the terminal and logged into gnome decides to shut-down the computer via the GUI.  What is the worst that can happen under this circumstance? Are there any mechanism that prevents the packages from being left in a 'dirty' state? If not, how to prevent that?


Since the language is one that I don't understand, and the layout of the 'settings' seems  different to the proposed answer- I cannot guess where to go next. I have changes the language in some individual pages eg Web Store, but it goes back to Dutch on restarting the browser!

Suddenly, my Chrome language has been changed to Tamil. I didn't make this change manually. I don't know how to change this setting to English.


I want to prove that the geometric Hahn Banach theorem implies the analytic one.   Edit:  To avoid confusion I will state the vesion of H.B theorems im familiar with:  Analytic H.B:   Let $X$ be a linear space(over $\Bbb R$) and $Y\subset X$ a subspace. Let $p:X \to \Bbb R$ be a sub-additive function. Suppose $f:Y\to \Bbb R$ is a linear map s.t $f(y) \le p(y)$ for all $y\in Y$ then there exists an extention $g:X\to \Bbb R$ of $f$ s.t. $g(x)\le p(x) $ for all $x\in X$.  Geometric H.B:  Let $X$ be a linear space. $K \subset X$ convex s.t. each point in $K$ is an internal point. Let $D$ be a plane disjoint from $K$ then there exists hyperplane that contains $D$ and disjoint from $K$.  In my problem $X$ is NOT a normed space so there are no open sets.   Given $X$ a linear space and $Y\subset X$ a subspace $p:X\to \Bbb R$ sub-additive, and $f:Y\to \Bbb R$ linear s.t $f(y)\le p(y)$ for $y\in Y$ we need to extend $f$ to $g:X\to \Bbb R $ and $g(x)\le p(x)$ fo r all $x\in X$  So, we look at $X \times \Bbb R $and define $K = \{(x,t) : t>p(x)\}$.  The fact that $K$ is convex is easy. How can I show directly that every point in $K$ is internal? (can't say that $K$ is open).  Now after showing that, we can look at $Graph(f)$ and observe that $Graph(f)\cap K = \emptyset$.  So by the geometric H.B theorem we have a hyperplane (which is a maximal subspace in this case because $(0,0)\in Graph(f)$ ) M containing $Graph(f) $ and disjoint from $K$.  Now my problem is to show that each $x\in X$ has a unique $t\in \Bbb R$ s.t. $(x,t) \in M$.  (I need it in order to extend $f$).  I know that if we take $v_0\notin M$ then each $v \in X \times \Bbb R$ has a unique representation as $v = \alpha v_0 + m$ for $m \in M$ , this is because $M$ is a maximal subspace. not sure if that helps.  Thanks for helping!

I've come across a proof online of the H.B theorem using the goemetric version.   There is a step in the proof which im not sure why is true and it is as follows:   Let $X$ be a linear space and $M \subset X \times \Bbb R$ be a maximal subspace.  Then $M = G(F)$ for $F :X \to \Bbb R$ linear.   Someone can show me why this is true?   Maybe I misunderstood the proof, its the last paragraph of Matrin's answer here -.   Thanks a lot for helping!


My laptop's charger was not working anymore. So I bought a new one. However I couldn't find an exact matching charger, I bought a different one. My question is; Will there be any problems with new charger? Specifications of chargers are below;  Original charger: 65W, input: 100-240V, 1.6A, 50-60 Hz, output: 18.5V, 3.5A  The new one I bought: 90W, input: 100-240V, 1.5A, 50-60Hz, output: 19V, 4.74A

My laptop's cable broke and sadly it seems like I need to buy a new power supply.  What I wonder is, I've found that universal power supplies are much cheaper than the official HP ones. Are they really worth it?  Another question: the original supply has these specs: 65W, 18.5V, 3.5A. However the universal supplies are more powerful (90W, 100W) and come in integer voltages (17V, 18V, 19V, etc). Are they compatible? Should I set them to 18V or 19V?


When I download Instagram and click on "create new account", an email address auto-populates. Where is it gathering this information? How do I make it go away?

Steps to reproduce problem:   Log out of instagram app Close the app click on it to open it and log back in Log-in screen is displayed, with the user name filled in (not yet logged in (i.e. still logged out)) and password field beneath blank   How do you clear all Instagram app settings and what it remembers after you have logged out? So that it doesn't remember (i.e. forgets) your user name so that it doesn't pre-fill in this field at the login screen?  There are options to clear data in the Settings screen, but these are too blanket and coarse in that they clear everything - I only want to clear one thing.  Problem seen on Sep 2010 (4th generation) iPod touch 32Gb. IOS Version 6.1.5 (10B500)  Latest version of Instagram app, as of date 2014 05 18.


I am fairly new to bashrc and am learning about the alias feature.  I am trying to create an alias that will open my java ide without me having to do 2 commands.  This is the commands I usually have to do   >cd idea-IU-143.381.42/bin >./idea.sh   When I try to setup an alias   alias idea= 'cd ~/idea-IU-143.381.42/bin; ./idea.sh'   and restart my terminal I get the following error   bash: alias: cd ~/idea-IU-143.381.42/bin; ./idea.sh: not found HP-Pavilion-TS-15-Notebook-PC:~$    Any help?

So before I reformatted (to get rid of Windows), I simply used this command to open documents by putting it at the end of the ~/.bashrc file:  alias commandless= 'gnome-open ./Documents/the-linux-command-line.pdf; gnome-open ./Documents/linux.odt'   But now everytime I start the terminal, it says:  bash: alias: gnome-open ./Documents/the-linux-command-line.pdf; gnome-open ./Documents/linux.odt: not found   before even typing anything in, and when I run the command nothing happens, not even error messages.


My Disk Utility is showing me some Weird Stuff.  My current startup partition is showing as 155 GB, with (I was shocked to discover) 344 GB of unpartitioned free space:    I can try to resize the first partition by removing the "Free space" section, then hit "Apply", but then I get this error:    Actually, if I try this a few times, I get variously different errors.  Sometimes it even says it succeeds, but the partition size doesn't seem to have changed.  When I retry this same sequence after booting from my recovery partition, basically the same result happens, except that now I have two "Free space" partitions, both showing 344 GB, in addition to the 155 GB startup partition.  What's going on here, and how can I take advantage of my full 500 GB disk?  Or do I not actually have a 500 GB disk??  Here's the Disk Utility info for the physical disk - notice that it says it's 500 GB, but the 155 GB partition takes up the whole blue bar:    I'm using High Sierra 10.13.6, on a Late 2011 MacBook Pro 13".

I bought a new SSD with 750 GB and made two partitions: 600 GB and 150 GB. The smaller one was thought to be a Bootcamp partition one day, but to date it was just another unused partition. When I needed more space, I decided to merge these two partitions. The partition was created with Mavericks, the merge was done with Yosemite.  I opened Disk Utility and the "minus" button. Disk Utility told me both partitions would be merged then. However it miserably failed. My main hard disc suddenly had errors which couldn't be repaired and even two of my other external hard discs could not be mounted any longer.  I eventually restored the hard disc from Time Machine, which worked well.  My second partition is now listed as free:    Unfortunately I can't resize the 600 GB partition nor can I create a new partition using the free space.  Diskutil reveils the following:  ~  diskutil list /dev/disk0    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *750.2 GB   disk0    1:                        EFI EFI                     209.7 MB   disk0s1    2:          Apple_CoreStorage                         599.6 GB   disk0s2    3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3 /dev/disk1    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:                  Apple_HFS Macintosh HD           *599.3 GB   disk1                                  Logical Volume on disk0s2                                  XXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX                                  Unencrypted   Also diskutil brought up this:  ~  diskutil cs list CoreStorage logical volume groups (1 found) | +-- Logical Volume Group 9D2BA4BA-xxxx-xxxx-xxxx-xxxxxxxxxxxx     =========================================================     Name:         Macintosh HD     Status:       Online     Size:         599640592384 B (599.6 GB)     Free Space:   6111232 B (6.1 MB)     |     +-< Physical Volume 29A9A02B-xxxx-xxxx-xxxx-xxxxxxxxxxxx     |   ----------------------------------------------------     |   Index:    0     |   Disk:     disk0s2     |   Status:   Online     |   Size:     599640592384 B (599.6 GB)     |     +-> Logical Volume Family 2FA7892F-xxxx-xxxx-xxxx-xxxxxxxxxxxx         ----------------------------------------------------------         Encryption Status:       Unlocked         Encryption Type:         None         Conversion Status:       NoConversion         Conversion Direction:    -none-         Has Encrypted Extents:   No         Fully Secure:            No         Passphrase Required:     No         |         +-> Logical Volume 7BF42B7B-xxxx-xxxx-xxxx-xxxxxxxxxxxx             ---------------------------------------------------             Disk:                  disk1             Status:                Online             Size (Total):          599282155520 B (599.3 GB)             Conversion Progress:   -none-             Revertible:            No             LV Name:               Macintosh HD             Volume Name:           Macintosh HD             Content Hint:          Apple_HFS   I have tried this:    fsck -fy (The volume Macintosh HD appears to be OK.)   but it wouldn't help. It said I couldn't recover because it wasn't created in a way it would support (sorry for missing the exact message).  I then have learned that Apple_CoreStorage might indicate my disk is encrypted, which might explain why I can't resize it. It doesn't explain why I can't create a new partition to me.  What are my options to make my hard disk available in a single partition with size 750 GB?


My iPod 5 is stuck on voice over, but it's also on lock screen. I do not know how to unlock it and get to settings to turn it off.

My iPhone 4 is in VoiceOver mode. It`s currently locked and not accepting my passcode which is absolutely correct. And now it's saying iPhone is disabled.  Any solution?


Let $X = (X_1,X_2,\dots, X_n)$ be a sample from $N(\alpha\sigma, \sigma^2)$, where $\alpha$ is known real number. Show that the family of distributions of $T(X) = (\sum X_i, \sum X_i^2)$ is not complete for $\sigma$.   I am trying to show some counterexample for $g(X)$ such that $E(g(T))=0$ but $g$ is not $0$ a.e., but could not find any. Thanks for any help.

Let $X_{1},\ldots,X_{n}\stackrel{\text{ i.i.d }}{\sim}N(\mu,\mu^{2})$.  $T=\left(\sum_{i=1}^{n}X_{i},\sum_{i=1}^{n}X_{i}^{2}\right)$ is a sufficient statistic for $\mu$. Also $T$ is minimal sufficient.  However, the question is: Prove that $T$ is not complete, hint: use $f(x,y)=x-2y^{2}/(n+1)$.  To prove that $T$ is not complete, I must find an example of a Borel function, $f$, for which $E_{\theta}(f(T))=0$ does not imply $f(T)=0$. However, I do not know how to interpret the 'hint', since I only can conclude that $f(T)=0$, whenever using $x=\sum_{i=1}^{n}X_{i}$ and $y=\sum_{i=1}^{n}X_{i}^{2}$ and calculating $E_{\theta}(f(T))=0$.


I'm getting the following error on Ubuntu 16.04 server when I try to install anything with apt;  gzip: stdout: No space left on device  But I do have plenty of space as you can see here;  ~ # df -h Filesystem      Size  Used Avail Use% Mounted on udev             32G     0   32G   0% /dev tmpfs           6.3G  8.0M  6.3G   1% /run /dev/md2        437G  186G  229G  45% / tmpfs            32G     0   32G   0% /dev/shm tmpfs           5.0M     0  5.0M   0% /run/lock tmpfs            32G     0   32G   0% /sys/fs/cgroup /dev/md1        488M  469M     0 100% /boot tmpfs           6.3G     0  6.3G   0% /run/user/0   Inodes:  ~ # df -hi Filesystem     Inodes IUsed IFree IUse% Mounted on udev             7.9M   441  7.9M    1% /dev tmpfs            7.9M  2.3K  7.9M    1% /run /dev/md2          28M  395K   28M    2% / tmpfs            7.9M     1  7.9M    1% /dev/shm tmpfs            7.9M     4  7.9M    1% /run/lock tmpfs            7.9M    17  7.9M    1% /sys/fs/cgroup /dev/md1         128K   330  128K    1% /boot tmpfs            7.9M     4  7.9M    1% /run/user/0   What's the problem and how can I fix this?  Note: I tried this answer but it didn't help;

My /boot partition is nearly full and I get a warning every time I reboot my system. I already deleted old kernel packages (linux-headers...), actually I did that to install a newer kernel version that came with the automatic updates.  After installing that new version, the partition is nearly full again. So what else can I delete? Are there some other files associated to the old kernel images?  Here is a list of files that are on my /boot partition:  :~$ ls /boot/ abi-2.6.31-21-generic         lost+found abi-2.6.32-25-generic         memtest86+.bin abi-2.6.38-10-generic         memtest86+_multiboot.bin abi-2.6.38-11-generic         System.map-2.6.31-21-generic abi-2.6.38-12-generic         System.map-2.6.32-25-generic abi-2.6.38-8-generic          System.map-2.6.38-10-generic abi-3.0.0-12-generic          System.map-2.6.38-11-generic abi-3.0.0-13-generic          System.map-2.6.38-12-generic abi-3.0.0-14-generic          System.map-2.6.38-8-generic boot                          System.map-3.0.0-12-generic config-2.6.31-21-generic      System.map-3.0.0-13-generic config-2.6.32-25-generic      System.map-3.0.0-14-generic config-2.6.38-10-generic      vmcoreinfo-2.6.31-21-generic config-2.6.38-11-generic      vmcoreinfo-2.6.32-25-generic config-2.6.38-12-generic      vmcoreinfo-2.6.38-10-generic config-2.6.38-8-generic       vmcoreinfo-2.6.38-11-generic config-3.0.0-12-generic       vmcoreinfo-2.6.38-12-generic config-3.0.0-13-generic       vmcoreinfo-2.6.38-8-generic config-3.0.0-14-generic       vmcoreinfo-3.0.0-12-generic extlinux                      vmcoreinfo-3.0.0-13-generic grub                          vmcoreinfo-3.0.0-14-generic initrd.img-2.6.31-21-generic  vmlinuz-2.6.31-21-generic initrd.img-2.6.32-25-generic  vmlinuz-2.6.32-25-generic initrd.img-2.6.38-10-generic  vmlinuz-2.6.38-10-generic initrd.img-2.6.38-11-generic  vmlinuz-2.6.38-11-generic initrd.img-2.6.38-12-generic  vmlinuz-2.6.38-12-generic initrd.img-2.6.38-8-generic   vmlinuz-2.6.38-8-generic initrd.img-3.0.0-12-generic   vmlinuz-3.0.0-12-generic initrd.img-3.0.0-13-generic   vmlinuz-3.0.0-13-generic initrd.img-3.0.0-14-generic   vmlinuz-3.0.0-14-generic   Currently, I'm using the 3.0.0-14-generic kernel.


For example: $“THHTHTTHHHTHTHTTHHTHT”$ contains 1 run of heads of length 3,  2 runs of length 2, and 4 runs of length 1.   Assuming $P(H) = p$ and $P(T) = (1-p)$, calculate (using properties such as conditional  probability and Bayes’ Rule) the probability of runs of $H$eads of length $n$.  Where: $P(H)$ is the probability of heads $(p)$ $P(T)$ is the probability of tails $(1-p)$  The implication that conditional probability and Bayes' Rule can be used would imply that this solution is much more simple than I am making it. That being said, numerous searches have returned complex solutions containing recursive functions, often the Fibonacci series. Furthermore, none of the solutions I have seen are consistent with one another.     From the derived equation, I know that I can then use the linearity of expectation to quickly solve for the probability of runs of length $k = 1, 2, ... 10$ for a total number of events (flips) $N >> 1$    What I could use assistance with is calculating runs of $H$eads of length n given the probabilities for heads $(p)$ and tails $(p-1)$.

Suppose a biased coin (probability of head being $p$) was flipped $n$ times. I would like to find the probability that the length of the longest run of heads, say $\ell_n$, exceeds a given number $m$, i.e. $\mathbb{P}(\ell_n > m)$.   It suffices to find the probability that length of any run of heads exceeds $m$. I was trying to approach the problem by fixing a run of $m+1$ heads, and counting the number of such configurations, but did not get anywhere.  It is easy to simulate it:    I would appreciate any advice on how to analytically solve this problem, i.e. express an answer in terms of a sum or an integral.  Thank you.


If I get 30 upvote in answers with a particular tag, does it calculate 30 score for me in top users section  or just 20 score ? ( considering maximum daily reputation of 200 for upvotes )

I am trying to test out my wrapper for the API by writing a little test to calculate the score of a user in a particular tag.  I can't seem to make my totals add up to the sites'.  This is most likely caused my a bug in my code, but to be sure I want to know exactly how the 'score' of a user is calculated.  Edit: I was hoping to get some hard and fast facts from one of the staff.  Do y'all know how you are calculating the score?  Is it just upvotes?  Does it count votes that were received before a answer was made wiki?


Well all is in the title. How to be removed from their spam list? We don't use external email provider for now. We respect emails good practices: signed email, unsubscribe link, dest email...  Here are different tests, nothing bad reported:         Can we contact Microsoft for a manuel check?

This is a  about how to handle email sent from your server being misclassified as spam.  For additional information you may find these similar questions helpful:                    Sometimes I want to send newsletters to my customers. The problem is, that some of the emails get caught as spam messages. Mostly by Outlook at the client (even in my own Outlook 2007).  Now I want to know what should be done to create "good" emails. I know about reverse lookup etc., but (for example), what about a unsubscribe link with an unique ID?  Does that increase a spam rating?


I am not an SEO expert but I tought that Google use the <title> to display link in the search results. For a reason that I don't know, It add the domain at the end of the link. Does anybody have an idea why?  Web page source code:  <html xmlns="http://www.w3.org/1999/xhtml"> <head>   <title>     Home | Le Boot Camp - Sleeman   </title>   What Google display:

I'm just wondering how it is possible that IGN.com has this in its title tag:      Video Games, Cheats, Walkthroughs, Game Trailers, Reviews, News, Previews & Videos at IGN   while on Google its title is simply "IGN".   How can one achieve such a thing? Does it use some special meta tag I can't see?


My built-in wireless card doesn't switch on. I have run out of ideas to enable it, or install the driver. When I run rfkill, it shows no hard block or no soft block. I have been trying this for days, and I don't know what to do now. I have also looked for instructions; no help there.  lspci -v returns the following:  03:00.0 Network controller: Broadcom Corporation BCM43228 802.11a/b/g/n  Subsystem: Foxconn International, Inc. Device e04b  Flags: bus master, fast devsel, latency 0, IRQ 19 Memory at f0500000 (64-bit, non-prefetchable) [size=16K]  Capabilities: <access denied> Kernel driver in use: bcma-pci-bridge

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


Here are things that you may need to know:   I first read this in an anthology which was used for a college class ca. 1995. I remember that the cover was a picture of a starscape; nothing fancy, just a background of black with white stars.  And the anthology title, too, was on there, I'm sure.  This anthology also had the story of "In the land of the blind, the one eyed man is king". Aldous Huxley?     The plot goes something like this:  A spaceman from Earth (astronaut) experiences a collision and needs to make repairs.  But he's by himself (it is a "he"), and he needs to time things. To do this, he starts counting in seconds and then does quick math to determine different timers.  Then he needs to keep counting to track numerous things, like objects, processes, and time.  He gets to a point where he realizes after a while that he can't stop counting.  It's automatic and unending.  The story goes on to describe the consequences, good and bad (and terrible) of his ability to do this.   Anybody remember anything like this? Thanks for your time.   Edit 1:  The story I read was in English.   Edit 2:  I do not know the original publication date.  No clue actually, other than before 1995.  Edit 3:  I do not recall anything about the author's name or gender.  Sorry.  Edit 4:  Trying to recall, but I remember that the astronaut returns to Earth and talks with a person from the ground crew involved in the mission; the Director, maybe.  And I think it is the same person that talked to the protagonist right after the collision at the beginning of the story.

I'm looking for a short story about a man who wakes (maybe on a spaceship) after some accident to find that time is running very slowly, so he believes he has all the time in the world to think about puzzles, but then time starts to speed up so he doesn't after all.


When  watching , a claim that the volt and unit of resistance (presumably the ohm) will change by about 1 part in 10 million caught my attention:     [...] I should point out that a volt will actually change by about 1 part in 10 million, and resistance will change by a little bit less than that. And that's because back in 1990, the electrical metrologists decided to stop updating their value of, effectively, plancks constant, and just keep the one they had in 1990. And there was a benefit to that: they didn't have to update their definitions or their instruments. [...] Well, now the electrical metrologists will have to change. But, that's a very tiny change for a very tiny number of people.   Apparently, the reason is that . The kilogram will be redefined using the Planck constant, which, presumably, means that any change in value from the previous definition () would affect derived units depending on it,  and .      Will the volt or ohm change, as Veritasium seemingly claims?   Are any other electrical units (listed above) affected? If so, exactly how much will they have changed after the redefinition?

The metrology world is currently in the middle of overhauling the definitions of the SI units to reflect the recent technological advances that enable us to get much more precise values for the fundamental constants of nature than were possible when the SI was drawn up. This has already happened to the second and the meter, which are defined in terms of a caesium transition and the speed of light, and it is being extended to the other units. Thus, in the new system, known as the ,     four of the SI base units, namely the kilogram, the ampere, the kelvin and the mole, will be redefined in terms of invariants of nature; the new definitions will be based on fixed numerical values of the Planck constant ($h$), the elementary charge ($e$), the Boltzmann constant ($k$), and the Avogadro constant ($N_A$), respectively.   The  gives more details, but it stops short of describing the recommended mises en pratique. For example, for the kilogram, the definition goes     The SI unit of mass, the kilogram         The kilogram, symbol kg, is the SI unit of mass; its magnitude is set by fixing the numerical value of the Planck constant to be exactly 6.626 069 57 10−34 when it is expressed in the SI unit for action J s = kg m2 s-1.         Thus we have the exact relation h = 6.626 069 57 10−34 kg m2 s-1 = 6.626 069 57 10−34 J s. Inverting this equation gives an exact expression for the kilogram in terms of the three defining constants $h$, $\Delta \nu$(133Cs)hfs and $c$:   $$ \mathrm{kg} =\left(\frac{h}{6.626 069 57\times10^{−34}}\right)\mathrm{m}^{2}\:\mathrm s^{-1} =1.475521\ldots\times 10^{40}\frac{h \Delta \nu\left(^{133}\mathrm{Cs}\right)_\mathrm{hfs}}{c^2} $$   The Planck constant is a constant of nature, whose value may be expressed as    the product of a number and the unit joule second, where J s = kg m2 s-1. The effect of this definition is to define the unit kg m2 s-1 (the unit of both the physical quantities action and angular momentum), and thus together with the definitions of the second and the metre this leads to a definition of the unit of mass expressed in terms of the value of the Planck constant $h$.      Note that macroscopic masses can be measured in terms of $h$, using the    Josephson and quantum-Hall effects together with the watt balance apparatus,    or in terms of the mass of a silicon atom, which is accurately known in terms    of $h$ using the x-ray crystal density approach.   However, the brochure is pretty scant as to what the specific realizations through watt balances actually imply in terms of a route from measured physical quantities to values of fundamental constants or to inferred masses. For the specific case of the watt balance, for example, the physical constants at play are much more naturally the  and  constants, $K_J=2e/h$ and $R_K=h/e^2$, if I understand correctly, so there is some re-shuffling of experimental results to be done.  The SI brochure is similarly vague for the other three base unit / fundamental constant pairs.  This brings me, then, to my specific questions. For each of these four base unit / fundamental constant pairs,   what are the proposed experimental realizations, what are the basics of their operation, and what physical effects do they rely on? what other fundamental constants are used to go from experimentally measured values to inferred parameters? (i.e. the meter depends on the second. Does the kilogram depend on the value of the electric charge?) what specific natural constants are measured by the experiment, and how are they reshuffled to obtain final results?   Additionally, what is the dependency tree between the different definitions of the base units? What units depend on what others, either directly or indirectly?


In some PSE questions or answers such as  there appears the notion of "accelerating frame" or (more or less equivalently) "noninertial frame".   What's the definition of this notion?, i.e. How are given participants (or, if you prefer, "point particles"$\,\!^{(*)}$) who "keep sight of each other" supposed to determine whether they (pairwise) belonged to the same "noninertial frame", or not?  $(*$: Cmp. the notion of "inertial frame", in distinction to "inertial coordinate system", of  We should, strictly speaking, differentiate between an inertial frame and an inertial coordinate system, although in sloppy practice one usually calls both IFs. An inertial frame is simply an infinite set of point particles sitting still in space relative to each other.$)$.  Follow-up: The new (follow-up) question to be asked to fully address this question has been submitted as

I'm struggling with the notion of an inertial frame of reference. I suspect my difficulty lies with the difference between Newtonian and relativistic inertial frames, but I can't see it.   I've read that Newton's laws apply in any non accelerating frame of reference, which are called inertial frames. So, if I play pool on a train moving with uniform velocity, the balls behave in the same way as if I were playing pool in a pool hall. So the train is (to a good approximation, ignoring forces caused by the Earth's rotation and movement around the Sun etc) an inertial frame.   I've also read that in an inertial frame, Newton's first law is satisfied. So, if I slide a rock on a sheet of ice and I could somehow eliminate the frictional forces between the rock and the ice, the rock would carry on sliding for ever, as predicted by Newton's first law.   Question 1 - is the  sheet of ice also therefore a good approximation to an inertial frame?  Question 2 - are these two definitions of inertial frames saying the same thing in different ways?  Both these examples occur in gravitation fields, which doesn't seem to matter as both the train and the ice sheet are presumably good approximations to inertial frames.  Question 3 - is gravity irrelevant when defining these two inertial frames?  In special relativity, I've read (Foster and Nightingale) that an inertial frame is also one where Newton's first law holds. But as it's special relativity there cannot be an inertial frame if there's a gravitational field, so I'm assuming the above two examples are not inertial frames in special relativity.  Question 4 - how come you can use the same definition of an inertial frame (satisfied Newton's first law) but in the case of special relativity, the train and the ice sheet aren't inertial frames. Is this to do with not being able to synchronize clocks in a gravitational field?  In general relativity, I've read (Schutz) that a freely falling frame is (on Earth) the only possible (and local) inertial frame. So again the first two examples would not be inertial frames in general relativity.  Question 5 - am I right to think that my two examples aren't even approximate approximations to an inertial frame in relativity?  Question 6 - have I missed anything else that might be useful?  Many thanks  Edit. On reflection, am I right in thinking that because Newtonian mechanics assumes universal, absolute time we don't need to worry about synchronizing clocks in a Newtonian inertial frame. Therefore we don't need to worry about gravity in a Newtonian inertial frame, because in such a frame gravity does not affect time.  This is not the case in spacetime, as here gravity does affect time and the only way to have synchronized clocks in an inertial frame in spacetime is: 1. have no gravitational field, or 2. use a local, freely falling frame.  Am I on the right track here?


I am using Postgres. I have 2 tables. PS : week starts from monday. Time (id (bigInt), startOfWeek (Date), startOfMonth (Date), startOfQuarter(Date), day (Date) ...)  and User (id (bigInt), timeId (FK --> Time), total (Int)).  Given 2 dates (start and end), a dimension (day / week /month / quarter), I need to find out the total for each day / week / month / quarter. Example : Time (id (1), startOfWeek ('07-13-2015'), startOfMonth ('07-01-2015'), startOfQuarter('07-01-2015'), day ('07-13-2015') ...)  Time (id (2), startOfWeek ('07-13-2015'), startOfMonth ('07-01-2015'), startOfQuarter('07-01-2015'), day ('07-14-2015') ...)  //for 22nd july. Time (id (3), startOfWeek ('07-20-2015'), startOfMonth ('07-01-2015'), startOfQuarter('07-01-2015'), day ('07-22-2015') ...)  User (id (11), timeId (1), total (5)). User (id (12), timeId (2), total (10)). ...  Given 2 date values start and end, and dimension 'd' (W /M /Q etc) how can I write a query to fetch values from User table like : '07-13-2015' 100 '07-20-2015' 122 etc  The problem is the startOfWeek field will be same for 7 days. I need to get the value of only the first row in User table where startOfWeek changes.  I could do it using multiple queries :  get all startOfWeeks from Time table  for each startOfWeek, query User table and do first(..)    Is there a better / more efficient solution?

I am using Postgres 9.3.9. I have 2 tables :  f_agent :  CREATE TABLE f_agent (   f_agent__id bigserial NOT NULL,   f_agent__total_users integer NOT NULL,   f_agent__dim_time_id integer NOT NULL,   .... other unnecessary columns );   dim_time :  CREATE TABLE dim_time (   dim_time__id bigserial NOT NULL,   dim_time__date date NOT NULL,   dim_time__month_start_date date NOT NULL,   dim_time__week_start_date date NOT NULL,   dim_time__quarter_start_date date NOT NULL,   dim_time__year_start_date date NOT NULL,   dim_time__guid uuid NOT NULL DEFAULT uuid_generate_v4(), );   Now, f_agent__dim_time_id field in f_agent is FK referencing dim_time__id of dim_time.   My dim_time table has a date and its related week_start_date, month_start_date etc. For example: if dim_time__date is 14-07-2015 then dim_time__week_start_date will be 13-07-2015 (monday is start of week) and start_of_month is 01-07-2015 (always the first).   I have to find  f_agent__total_users from f_agent given a date range and a dimension (week / month / quarter).  What I've tried:   SELECT dim_time__week_start_date, f_agent__total_users  FROM f_agent JOIN dim_time      ON f_agent__dim_time_id = dim_time__id  WHERE dim_time__week_start_date IN (     SELECT generate_series('2015-07-06', '2016-07-03', '7 day'::interval) );   The output:   dim_time__week_start_date   f_agent__total_users "2015-07-13";                      3 "2015-07-13";                     33 "2015-08-10";                     12   But I only need the first value in case 2 week_start_dates are same. The output I am expecting here is:    dim_time__week_start_date   f_agent__total_users "2015-07-13";                      3 "2015-08-10";                     12   How can I do this?


I have a table that shows up after the example and exercises subsection. Is there a way to not anchor it to anything and have it appear in its original position in the code?  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage[margin=1.1in]{geometry} \usepackage{enumitem} \usepackage{multirow} \newtheorem{example}{Example}[section] \newtheorem{exercise}{Exercise}[section] \begin{document} \begin{table}[ht] \centering \caption{Set Identities} \begin{tabular}{ll} $\overline{(\overline{A})} = A$   & Double Negative \\ $A \cap U = A$  & \multirow{2}{*}{Identity Laws} \\ $A \cup \emptyset = A$  & \\ $A \cup U = U$  & \multirow{2}{*}{Domination Laws} \\ $A \cap \emptyset = \emptyset$  & \\ $A \cup A = A$  & \multirow{2}{*}{Idempotent Laws} \\ $A \cap A = A$  &  \\ $A \cup B = B \cup A$  & \multirow{2}{*}{Commutative Laws} \\ $A \cap B = B \cap A$  & \\ $A \cup (B \cup C) = (A \cup B) \cup C$  & \multirow{2}{*}{Associative Laws} \\ $A \cap (B \cap C) = (A \cap B) \cap C$  & \\ $A \cup (B \cap C) = (A \cup B) \cap (A \cup C)$ & \multirow{2}{*}   {Distributive Laws} \\ $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$  & \\ $\overline{A \cap B} = \overline{A} \cup \overline{B}$  & \multirow{2}{*}  {De Morgan's Laws} \\ $\overline{A \cup B} = \overline{A} \cap \overline{B}$  & \\ $A \cup (A \cap B) = A$  & \multirow{2}{*}{Absorption Laws} \\ $A \cap (A \cup B) = A$  & \\ $\overline{A} \cup A = U$ & \multirow{2}{*}{Negation Laws} \\ $\overline{A} \cap A = \emptyset$ & \end{tabular} \end{table}  \begin{example} Find the intersection of $A = \{2k|k \in \mathbb{N}\} \text{ and } B = \{3k|k \in \mathbb{N}\}$.  \smallskip \noindent \textbf{Solution:} The set $A$ represents all natural numbers divisible by $2$ and the set $B$ is the set of all natural numbers divisible by $3$. $A \cap B$ is the set of all natural numbers divisible by $2$ and $3$, therefore $A \cap B = \{6k | k \in N\}$. \end{example}  \subsection*{Exercises} \end{document}

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


I have written a simple script, to copy some files, and change there name:    #!/bin/bash for directory in ./../old_files/*; do     DIR_NAME=$(basename $directory)     for file in $directory/*; do         filename=$(basename -- "$file")         cp -- $file "./${DIR_NAME}_m*${filename}" 1>/dev/null     done done   And it's working great with one problem. If file has an accent or name is escaped with slash, it returns: cp: target 'xxx.pdf' is not a directory  Any ideas how to solve this?

Or, an introductory guide to robust filename handling and other string passing in shell scripts.  I wrote a shell script which works well most of the time. But it chokes on some inputs (e.g. on some file names).  I encountered a problem such as the following:   I have a file name containing a space hello world, and it was treated as two separate files hello and world. I have an input line with two consecutive spaces and they shrank to one in the input. Leading and trailing whitespace disappears from input lines. Sometimes, when the input contains one of the characters \[*?, they are replaced by some text which is is actually the name of files. There is an apostrophe ' (or a double quote ") in the input and things got weird after that point. There is a backslash in the input (or: I am using Cygwin and some of my file names have Windows-style \ separators).   What is going on and how do I fix it?


I'm attempting to write a class that solves a system of nonlinear equations (a root finder). For this, I've written a class that encapsulates all the internal functions needed, as well as the system to solve: a function that takes an Eigen vector and returns an Eigen. The public newt member function takes an Eigen vector (the initial guess), runs the algorithm with that initial guess, and returns the Eigen vector r such that func(r) = {0, 0, ..., 0}. I've written the functions as prescribed : writing template functions that take instantiations of MatrixBase.  The way I've handled taking an arbitrary function to solve was to implement a base class and then have the user extend it, defining func, the function to solve. The class I have is  class Newt { private:     template<typename TR, typename T1, typename T2, typename T3>     tuple<TR,bool> lnsrch(const MatrixBase<T1> &xold, const double fold, const MatrixBase<T2> &g, MatrixBase<T3> &p, const double stepmax);      template <typename TR, typename T1, typename T2>     TR fdjac(const MatrixBase<T1> &x, const MatrixBase<T2> &fvec);  public:     template <typename TR, typename T1>     TR func(const MatrixBase<T1>&);      template <typename TR, typename T1>     tuple<TR,bool> newt(const MatrixBase<T1> &xx); };   The user then inherits from Newt and overrides the func method to the desired function to solve:  struct NewtD : public Newt {     template <typename T1, typename T2>     T1 func(const MatrixBase<T2> &z) {         // Content     }    };   Then he instantiates it and calls the newt member function. However, when I compile this with the following test case:  struct Newt3 : public Newt {     template <typename T1, typename T2>     T1 func(const MatrixBase<T2> &x) {         return (Vectord<3>() <<              z(0),             z(1)*z(2),             pow(z(2)-1,2)         ).finished();     }    };  int main() {     Newt3 solver3;     bool check;     tie(X,check) = solver3.newt<Vectord<3>>(X); }   I get the following linker error, when compiling with g++ 6.2.0  undefined reference to `std::tuple<Eigen::Matrix<double, 3, 1, 0, 3, 1>, bool> Newt::newt<Eigen::Matrix<double, 3, 1, 0, 3, 1>, Eigen::Matrix<double, 3, 1, 0, 3, 1> >(Eigen::MatrixBase<Eigen::Matrix<double, 3, 1, 0, 3, 1> > const&)'   It seems it can't find newt? I have no idea why this is, the signature in the error seems to match my code, everything seems okay. Any idea how to solve this?  PS: Oh yeah, I forgot: Vectord<N> is a shortcut template type simply defined as   template<size_t N> using Vectord = Matrix<double, N, 1, 0>;   PPS: The implementation is in a separate file. I didn't include it because it's quite big, but bottom-line is every function is defined there, including Newt::newt  template <typename TR, typename T1> tuple<TR,bool> Newt::newt(const MatrixBase<T1> &xx) {     // Body }

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


The other day, I read this sentence " I don't like your bossing me around". I was wondering if this sentence should be " I don't like you bossing me around". Shouldn't be?  Would you please explain it to me?   Many many thanks in advance.

I assume that the following sentences are grammatically correct:   He resents your being more popular than he is. Most of the members paid their dues without my asking them. They objected to the youngest girl's being given the command position. What do you think about his buying such an expensive car? We were all sorry about Jane's losing her parents like that.   I'm still getting used to this possessive gerund structure. It sounded so weird to me at first. Is the structure used in both formal and informal contexts? Are there any alternative structures that result in the same meaning and are more frequently used? (Examples taken from )


I am living in London, but moving to a suburb where my commute would take me through a park. Being rainy England, the track can get quite muddy and my current tyres don't seem to be suitable. What features should I look for in a tire for this purpose? The bike in question is am aluminum Trek Checkpoint. I currently have 32mm Continental Gator Hardshell tires, which are slick tires with puncture protection.

How do I determine what factors lead to a good all purpose city commuting winter tire? Does the rim matter?  I'd like to not have to worry too much about looking out for and avoiding black ice, mainly because I'm not sure you can even do that reliably?  I'll be riding on roads and bike paths but if I encounter an unplowed section, I'd want to be able to get thru the snow without too much trouble.  I am interested in NYC so please factor that into your reply if possible, although a general answer would be great. FYI in NYC in January there's 8 inches of snow across 4 days, and 4 inches of rain across 10 days. Average temperature is 26F low, 38F high.


The corollary says if $ f $ is differentiable on $ [a,b] $ then $ f' $ cannot have any simple discontinuities on $[a,b] $.   I just don't how to prove it.  I think it should be proved on both two cases of simple discontinuities(first type and second type of simple discontinuities).  Thanks in advance.

I have a question about the corollary to theorem 5.12 in Rudin's Principles of Mathematical Analysis (page 108):  Suppose $f$ is a real differentiable function on $[a,b]$ and suppose $f'(a)< \lambda < f'(b)$ then there is a point $x \in (a,b)$ such that $f'(x) = \lambda$ Corollary: If $f$ is differentiable on $[a,b]$ then $f'$ cannot have any simple discontinuities on $[a,b]$.  Can someone help me to show how he uses the result in the "main theorem" in the corollary?  (There are two cases of simple discontinuities  $f(x+) = f(x-) \neq f(x)$ and $f(x +) \neq f(x-)$


I have heard that auras can be recorded in photographs, but I don´t know how to do it. Does it have to do with filters?

What is the easiest way of taking Kirlian pictures (photographic techniques used to capture the phenomenon of electrical coronal discharges)?     Kirlian photography, although the study of which can be traced back to   the late 1700s, was officially invented in 1939 by Semyon Davidovitch   Kirlian.  The Kirlian photographic process reveals visible “auras”   around the objects photographed.  These photographs have been the   subject of much myth and controversy over the years.   For clarification, I'm not concerned whether this is a digital or analog solution.


I have a very peculiar problem with my ubuntu 18.04 LTS. I press Ctrl+Alt+F1 to go to tty1 as always. And there is the classic screen that you have to login as always. But when I try to login this happens:  I put my username and click enter. Then the password field shows up but the terminal clicks return automatically before me being able to enter my password. Then of course it asks for password again, and then terminal clicks return again. Then the whole login thing resets and asks for username again but terminal keeps clicking return and at some point it completely resets and it stops as if I had just pressed Ctrl+Alt+F1.  Anyone have any clues?   Thanks

I upgraded from 16.04 to 18.04. When I press Ctrl+Alt+F3 I get the terminal which prompts for the username. When I type my username and press Enter, it doesn't wait for my password (its as if I pressed Enter without entering anything). Even if I enter something, the text shown in plaintext and then it keeps on saying my password is wrong. After few times, the screen is cleared and it prompts for my username again and the same loop goes on.


My question did not get a true answer. Half of my bounty was auto-awarded to an unhelpful answer. How do I dispute that?  Ref:

Auto-selecting answer for rewards is really annoying   had no good answers so I set a bounty on it. It received one new answer that was completely irrelevant, and that was auto-selected. I do understand the policy of losing the points regardless of if an answer is selected, in order to not motivate people to not accept an answer. But I don't see how the auto-selection feature contributes constructively to anything.  I figured this would have been discussed extensively elsewhere but I only found .


It seems that the mysql select parameter is being inserted with double quotes  string strEstablishments = String.Join(",", myEstablishments);   strEstablishments contains (from the VS2019  debug window)    "'1007','3'"   sqlDSselectEstablishment.SelectParameters.Add("Establishments", strEstablishments);  sqlDSselectEstablishment.SelectCommand = "SELECT EstablishID,Description FROM tblEstablishment WHERE EstablishID IN (@Establishments)";   But this doesn't give the result expected it only returns one result that the dropdown is populated with but should return two (establishments 1007 and 3)  It seems to me the double quotes around the string are being injected which would explain the returned results, I've tried removing them using strEstablishments.Replace("\"","") with no joy.  Running the below command from MySQL directly returns the results as expected:  SELECT EstablishID,Description FROM tblEstablishment WHERE EstablishID IN ('3','1007');   Any ideas how I can get the result as expected using asp.net

How do I parameterize a query containing an IN clause with a variable number of arguments, like this one?  SELECT * FROM Tags  WHERE Name IN ('ruby','rails','scruffy','rubyonrails') ORDER BY Count DESC   In this query, the number of arguments could be anywhere from 1 to 5.  I would prefer not to use a dedicated stored procedure for this (or XML), but if there is some elegant way specific to , I am open to that.


Prove that the only prime triple is $3,5,7$.  I tried proving using this method: Multiplication of $3$ jumps back and forth between being an even and an odd number. Thus goes from odd to odd over an interval max size 6, and likewise from even to even. In either case these will have the following types: (even - odd - even - odd - even - odd) and (odd - even - odd - even - odd - even), with 3 being a multiple of the first instance in the combinations. In the both combinations, the first and fourth would be divisible by three, leaving only two possible primes left (two odd numbers). Thus the only triple prime can be a combination where three is considered a prime....  However, is this a formal proof? can anybody tell me how to do a proof for this questions?

Intuitively it's true, but I just can't think of how to say it "properly".  Take for example, my answer to the following question:     Let $p$ denote an odd prime. It is conjectured that there are infinitely many twin primes $p$, $p+2$. Prove that the only prime triple $p$, $p+2$, $p+4$ is the triple $3,\ 5,\ 7$.   And my solution:     Given an odd integer $n$, between the three integers $n$, $n+2$ and $n+4$, one of them must be divisible by $3$... Three possible cases are $n=3k$, $n+2=3k$, and $n+4=3k$. The only such possible $k$ that makes $n$ prime is $k=1$. In this case, given an odd prime $p$, either $p=3$, $p+2=3$, or $p+4=3$. This would imply that $p=3$, $p=1$, or $p=-1$. The only of these three that is prime is $p=3$, therefore the only three evenly distributed primes are $3$, $5$, and $7$.   Is there a "better" way that I can assert that one of the integers is divisible by 3? This feels too weak.


for all prime number $x,y,z$, $x^2 + y^2 \ne z^2$.  I assume $x^2+y^2 = z^2$, then $x^2 = z^2 - y^2$, so we have $x^2 = (z+y)(z-y)$ but I don't know how to continue because I don't know any number theory theorem.

Suppose $a$, $b$ and $c$ are three prime numbers.   How to prove that $a^2 + b^2 \neq c^2$?


I tried to ask this question but some users thought it was a duplicate and closed the question. I explained it in a comment but in any case, I wrote an extension method in C# and it will appear in an answer.

Given a specific DateTime value, how do I display relative time, like:   2 hours ago 3 days ago a month ago


ajax Code:          $('.remove-item').click(function () {                 var iddata = $(this).attr("data");                 var confirmation = confirm("are you sure?");                 if (confirmation == true) {                     $.ajax({                         type: 'POST',                         url: "@Url.Action("_Delete","Item")",                         data: { Id: iddata },                         ajaxasync: true,                         success: function (data) {                             alert(data);                             $('.wrap').html(data);                         },                         error: function () {                             alert("error");                         }                     });                 }             });   Basically after first succesfull attempt to call this ajax, I'm refreshing/replacing partial view with (data) and when I try to delete item from list that is in data.. nothing is happening I don't know what info is neede yet for this.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I have installed Opera browser but an older version. Because, the most recent version does not play Netflix and some more platforms videos. This issue is related with libffmpeg.so file and WidevineCDM. However, I solved this issue using an older version of Opera. Now, I want an exception for Opera. I want it to be not updated when I enter the command sudo apt-get update. How can I do that? Thanks.

Because of  I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package.   How can this be achieved?


I know that Lorentz force acts perpendicularly with the motion of the charged particle and curves the path into a circular one ,but how to show it mathematically?

When an electron moves in uniform external magnetic field, with velocity not perpendicular, I understand that the magnitude of force is only due to the perpendicular component of velocity and is perpendicular to both components of velocity. But this force, though only due to the perpendicular component, acts on the particle. So why is it that the parallel component of velocity is not changed whereas the perpendicular component of velocity keeps changing its direction.   Is there a way to prove that its path is helical, using only vectors, and to show that it does not affect the parallel component? I've tried looking everywhere but haven't found any proof using vectors.


Babies are born with . I heard on The radio that when a child is given antibiotics for the first time unique bacteria in the stomach are destroyed and cannot be replaced. Is this true, and, if so, does this have negative effects on the health of the newborn?  Closely Related, but different:

states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a bacterial infection, her unborn baby risks catching it, too. This would seem to contradict the Scientific American article.  Presumably, when a human egg is fertilized by a sperm, the resulting cell may be free of any bacteria. At some point, bacteria begin to colonize the growing human body. Which bacteria are the earliest to colonize, and at what point in the development cycle does this occur?  In particular: does the health of the foetus depend on the presence of certain bacteria?


I have two UK passports. On one i have a valid ESTA, on the other i have recently travelled to Sudan. Will US CBP know details of travel in both passports? I ask this as from 21/01/16 an ESTA is no longer valid for people to have been to Sudan since 2011.

Now that  is in effect, people who have visited Iraq, Syria, Iran, or Sudan since 2011 are banned from entering the US under the Visa Waiver Program. However it's unclear to me how could the US officials prove one has set foot in those countries, unless:   There's a stamp in one's passport indicating so, which can be side-stepped by getting a fresh passport One mentions the fact on the ESTA application form, which is obviously easy to avoid   Is there any other way the US might be able to identify such individuals?  NB: I'm not eligible for the VWP myself and don't plan to travel to the four countries above, so it's a purely theorethical question


I’ve created a dump of all statistics on all tables in a Production database (based on the three sets returned by DBCC SHOW_STATISTICS). The database has been up and running for several months, and is actively used around the clock.  Reviewing it all, I find that several statistics are not actually set. That is, the statistics entry is there, but “LastUpdated” is null, and there are no steps in the histogram table. I am not able to find a consistent reason for this—some are for indexes, unique indexes, filtered, indexes, filtered unique indexes, and auto-generated stats.  Why is this? I can see a handful of remotely possibly reasons. Many are for where there is no data in the table (this makes sense), but there are many that do have rows (up to 10s of millions), and for any reason that might barely explain it ( “first-column duplicates” of other stats/indexes, unique indexes, filtered indexes, unlikely datatypes such as bit or large nvarchars), I can find something similar in another table/index where statistics are present.  I’m mostly convinced it’s not just one single thing. What are the possible reasons that statistics might not be present for tables under these conditions? How worried should I be about this?

Info  My question relates to a moderately big table (~40GB data space) that is a heap (Unfortunately, I am not allowed to add a clustered index to the table by the application owners)  An auto created statistic on an Identity column (ID) was created, but is empty.    Auto create stats & auto update stats are on Modifications have happened in the table There are other (auto created) statistics that are getting updated There is another statistic on the same column created by an index (duplicate) Build: 12.0.5546   The duplicate statistic is getting updated:   The actual question  To my understanding, all stats could be used and modifications are tracked, even if there are two statistics on exactly the same columns (duplicates), so why does this statistic remain empty?  Stats Info    DB stat info    Table Size    Column Information where the statistic is created on    [ID] [int] IDENTITY(1,1) NOT NULL   Identity column  select * from sys.stats   where name like '%_WA_Sys_0000000A_6B7099F3%';    Auto created  Getting some info on another statistic  select * From sys.dm_db_stats_properties (1802541555, 3)       In comparison with my empty stat:    Stats + Histogram from "generate scripts":  /****** Object:  Statistic [_WA_Sys_0000000A_6B7099F3]    Script Date: 2/1/2019 10:18:19 AM ******/      CREATE STATISTICS [_WA_Sys_0000000A_6B7099F3] ON [dbo].[table]([ID]) WITH STATS_STREAM = 0x01000000010000000000000000000000EC03686B0000000040000000000000000000000000000000380348063800000004000A00000000000000000000000000   When creating a copy of the stats, no data is inside  CREATE STATISTICS [_WA_Sys_0000000A_6B7099F3_TEST] ON [dbo].[table]([ID]) WITH STATS_STREAM = 0x01000000010000000000000000000000EC03686B0000000040000000000000000000000000000000380348063800000004000A00000000000000000000000000     When manually updating the stat they do get updated.   UPDATE STATISTICS [dbo].[Table]([_WA_Sys_0000000A_6B7099F3_TEST])


I know everyone here is big on bulkification..but I've never done it myself. Could somebody give me some pointers on how to bulkify this Trigger? It is a basic duplicate lead trigger.  //Look for duplicate leads based on email //Populate a Dupe_Lead__c field with the Lead if found  trigger DetectDupes on Lead (before insert, before update) {     for (Lead l : Trigger.new)     //Make sure the lead has an email address     {         if (l.Email != null)         {             //Find a duplicate             String leadEmail = l.Email;             String leadId = l.Id;              Date d = system.today().addDays(-7);              List<Lead> dupeLeads = [SELECT Id FROM Lead WHERE Email = :leadEmail AND Id != :leadId AND createdDate >= :d AND Email != 'na@na.na' AND Email != 'na@na.ca' AND Email != 'na@na.com'];              //If a duplicate is found, update the Dupe_Lead__c field. There is a validation rule that will not allow the record to save if this field is populated.             if (dupeLeads.size() > 0)             {                 l.Dupe_Lead__c = dupeLeads[0].Id;             }             else             {                 l.Dupe_Lead__c = null;             }         }             else          {              l.Dupe_Lead__c = null;            }      } }

A general question asked from time to time on stack exchange is question of trigger bulkification.  Therefore I have 2 questions:   Which best practices are you using? What is the best way to handle updates of more than 200 records? (In case of more than 200 records the trigger is executed more than once.)


I've installed XAMPP but I haven't got desktop entry so I created one. I'm using pkexec because it requests authorization. The problem is when I run my new desktop file nothing happens after I enter password. Here's the file:  [Desktop Entry] Name=Xampp GenericName=Localhost Server Exec=pkexec /opt/lampp/manager-linux-x64.run Terminal=false Icon=/opt/lampp/XAMPP.png Type=Application Categories=Programming;Development;   When I execute Exec line in terminal, this is the error I get after entering password:   What is this about?

I made a .desktop file for Androxyde's Flashtool (utility for Sony Xperia devices that I have to open with an executable file in its folder) that requires root privileges to use fastboot utilities. I used to make it work with gksu, but I'm on Ubuntu 15.04 and gksu is now old.  I tried to modify the exec line from Exec=gksu /home/natasha/FlashTool/FlashTool to Exec=pkexec /home/natasha/FlashTool/FlashTool Then, I read about pkexec doesn't allow to run X11 applications and so I override in this way:      The problem now is: It asks me the password but the Flashtool's GUI doesn't start. BUT if I execute that command in terminal, the program starts without problems. What can I do?


So why does the following works i.e. prints out the match:  THE_REGEX='^test\/version[0-9]+([.][0-9]+)+$' if [[ "$SOME_VAR" =~ $THE_REGEX ]]; then     echo "Match!" fi   But the following does NOT:  if [[ "$SOME_VAR" =~ '^test\/version[0-9]+([.][0-9]+)+$' ]]; then     echo "Match!" fi     What is the difference? It is the same regex

I want to determine whether a multi-line string ends with a line containing specified pattern.  These code failed, it doesn't match.  s=`echo hello && echo world && echo OK` [[ "$s" =~ 'OK$' ]] && echo match


Sup, guys. I have a table named 'mains' and 4 columns in it named 'ID', 'Date', 'Adresse' (yea-yea, I know there is mistakes in it) and 'Refills'. I need to INSERT new data if it not exists in table (checking it by ID), or if it exist UPDATE it. Problem is that I getting 'IF syntax error' and I really don't know why. Also, I have some qualm about 'UPDATE' part. Here is my code:  string CommandText = "IF (SELECT '" + Convert.ToInt64(dataGridView2[0, 0].Value) + "' FROM mains IS NULL) INSERT INTO mains (ID,Date,Adresse, Refills) values (" + Convert.ToInt64(dataGridView2[0, 0].Value) + ",'" + Date + "','" + Adresse + "'," + Convert.ToInt64(dataGridView2[3, 0].Value) + ") ELSE UPDATE mains SET Date='" + Date + "', Adresse = '" + Adresse + "', Refills = (Refills + 1) WHERE ID = '" + dataGridView2[0, 0].Value.ToString() + "' END IF";   Without C# (in SQL) it looks like:  IF (SELECT 'numerical id' FROM mains IS NULL) INSERT INTO mains (ID, Date, Adresse, Refills) values (numerical id, 'date converted to string (text)', 'text', number) ELSE UPDATE mains SET Date = 'date converted to string', Adresse = 'text', Refils = (Refils + 1) WHERE ID = 'numerical ID converted to string' END IF

Is there some clever way to do this in SQLite that I have not thought of? Basically I want to update three out of four columns if the record exists, If it does not exists I want to INSERT the record with the default (NUL) value for the fourth column. The ID is a primary key so there will only ever be one record to UPSERT. (I am trying to avoid the overhead of SELECT in order to determine if I need to UPDATE or INSERT obviously) Suggestions?  I cannot confirm that Syntax on the SQLite site for TABLE CREATE. I have not built a demo to test it, but it doesn't seem to be supported. If it was, I have three columns so it would actually look like: CREATE TABLE table1(      id INTEGER PRIMARY KEY ON CONFLICT REPLACE,      Blob1 BLOB ON CONFLICT REPLACE,      Blob2 BLOB ON CONFLICT REPLACE,      Blob3 BLOB  );  but the first two blobs will not cause a conflict, only the ID would So I assume Blob1 and Blob2 would not be replaced (as desired)  UPDATEs in SQLite when binding data are a complete transaction, meaning Each sent row to be updated requires:  Prepare/Bind/Step/Finalize statements unlike the INSERT which allows the use of the reset function The life of a statement object goes something like this:  Create the object using sqlite3_prepare_v2() Bind values to host parameters using sqlite3_bind_ interfaces. Run the SQL by calling sqlite3_step() Reset the statement using sqlite3_reset() then go back to step 2 and repeat. Destroy the statement object using sqlite3_finalize().  UPDATE I am guessing is slow compared to INSERT, but how does it compare to SELECT using the Primary key? Perhaps I should use the select to read the 4th column (Blob3) and then use REPLACE to write a new record blending the original 4th Column with the new data for the first 3 columns?


My answer to this is $8$ choose $3$ because of the non consecutive numbers, the $10$ choices go down to $8$ and we have to pick three digits.

During self-study, I ran across the question of how many ways six numbers can be chosen from the numbers 1 - 49 without replacement, stipulating that no two of the numbers be consecutive.  I can obtain a simple lower bound by saying that, in the worst-case scenario, when you choose a particular number, there are now three numbers that cannot be chosen next.  For example, if I first pick 17, then I can't choose 16, 17, or 18 for the remaining choices.  This gives me the lower bound  $$\frac{49*46*43*40*37*34}{6!} = 6,773,770 \frac{8}{9}$$  This is about 48% of ${}_{49}C_6 =  13,983,816$.  The real answer must be bigger (and an integer).  I haven't found a way to calculate it, though.  The original problem asked to show that the probability of having non-consecutive integers when you choose six is greater than 50%, so if the problem is complicated to count exactly, better approximations that show the answer is above 50% would also be appreciated.   Of course, I can use a computer to do the counting, but I'm interested in learning what methods I'm missing.


My function is defined as: $$f(x,y) =  \begin{cases}        \dfrac{xy^a}{x^2+y^2}&(x,y) \neq (0,0)\\      \ 0&(x,y) = (0,0)    \end{cases} $$   I want to find out for which $a\in \mathbb{R}$ the function is continuous. I am not quite sure how to solve something like this. I know that for $a=1$ the function is definitely not continuous, which can be checked, since $(\frac1n,\frac1n)$ converges to $(0,0)$ but $f(\frac1n,\frac1n)$ does not. Now if I want $f$ to be steady in $(0,0)$, I figured that this is the case if $a>1$. But this is where I get stuck. How to I prove or check, if for $a>1$ the rest of the function is continuous as well? Any help is greatly appreciated!

Consider the function $g:\mathbb{R^2} \rightarrow \mathbb{R}$ defined by   $g(x,y) = \left\{\begin{matrix}  \dfrac{x^3y}{x^2+y^2}& \textrm{if } (x,y) \neq (0,0) \\   0 & \textrm{if }(x,y) = (0,0) \end{matrix}\right.$  How do I prove this is continuous?  I know that I have to:  Consider $x_0 \in \mathbb{R^2}$, and let $\epsilon > 0$ be given. I am confused on how to pick a $\delta$ that will work such that $d(x,x_o) < \delta$.


I read like twenty years ago that the word "church" (clutch, hatch, match) is undoubtedly one syllable when written but that an argument can be made that it's two syllables -- CHUR-ch -- when spoken.  Actually I don't think the book put it in such ambiguous terms as much as I've yet to find anyone who would so much as entertain the notion.  Does anyone know what book I'm talking about (perhaps a Norton's Guide to... type book) or have any insight into this phenomenon?  Like maybe a name for such a word?  Other examples?

Does the word 'hour' have 1 or 2 syllables?


Reading a question on the Worldbuilding SE site a minute ago about a trip to the other side of the galaxy flying by the supermassive black hole in the center of our galaxy, my immediate first thought was: "How silly, how do you plan flying by close and ever again escaping, that's not just some black hole, it's a black hole strong enough to hold together an entire galaxy".  Which led me to say: "Oh, wait a moment...", and here comes the question: Is it (and if it is, how?), from everyday observation, plausible that there is indeed any such thing as Sgr A* at the center of our galaxy at all?  Earth rotates around itself and around the sun, and the sun orbits the center of the galaxy, in some kinda-elliptical but not alltogether trivial way. This means that I (and every object on Earth) rotate in some kind of semi-chaotic way, facing in every possible direction now and then. Inevitably, while standing on Earth's surface I will face "towards" the center of the galaxy at some point, and "away from" it at other times.  Now, that means one day the black hole's gravitation (which is strong enough to hold together a galaxy, so it is not as trivial as e.g. the Moon's or Mars' gravitation) would add to Earth's gravitation, and on another day it would pull the opposite way.  In other words, the weight of a constant-mass object should be very observably different on different days. That's apparently not the case, or someone would have wondered during the last couple of hundred years. What now?

Is it true that the whole galaxy is actually revolving, and powered by a black hole?  Has it been proven, and if it is true, how can our solar systems actually keep up the momentum to withstand the pull?


I'm trying to create an insert method for a trie in Java, where the method takes a string as an input, and checks to see if a node for each letter exists in the trie: I've attempted this once with a simple Array, and once with a HashMap as seen here:  Array Approach  // Simple Array approach public class trieNode {     char value = '\n';     final static int ALPHA_SIZE = 26;     int count = 0;     trieNode[] children = new trieNode[ALPHA_SIZE];     boolean isEnd = false; //signifies the end of a word     static trieNode root;     trieNode parent;      //constructor for the class         trieNode(){         for(int i = 0; i < ALPHA_SIZE; i++) {             children[i] = null;          }         }           //add a node to the trie.         static void trieInsert(String word) {              trieNode search = root;             for( int i = 0; i < word.length(); i++) {                 int index = word.charAt(i) - 'a'; //There doesn't seem to be any problem here, for example when the given char is c, index returns 2.                  if(word.charAt(i) == search.children[index].value) { //WHERE THE ERROR OCCURS                     search.children[index].count++;                     search.children[index].isEnd = false;                     search.children[index] = new trieNode();                 }             }             System.out.println(word + " has been added successfully to the trie.");         }   HashMap Approach:  public class TrieNode {     final static int ALPHABET_SIZE = 26;     char value;     boolean isEndOfWord;     boolean isTrieLeaf;     HashMap<Character, TrieNode> children = new HashMap();     int count = 0;     TrieNode root;     TrieNode parent;       TrieNode(){      }      void trieInsert(String word) {         TrieNode search = root;         for(int i = 0; i < word.length(); i++) {             if(search.children.containsKey(word.charAt(i))) {  //WHERE THE ERROR OCCURS                 search.children.get(word.charAt(i)).count++; //increase the count by one.                 search = search.children.get(word.charAt(i)); //this character must already be in the trie, check the rest of the word             }             else {                 search.children.put(word.charAt(i), new TrieNode()); //create a new node in the map for the character.                 search = search.children.get(word.charAt(i)); //move to the newly created node and start the process again.                  search.children.get(word.charAt(i)).count++; //update the base variables for the Trie.                 search.children.get(word.charAt(i)).isEndOfWord = false;             }                  if((word.length()-i) == 1)                     search.children.get(word.charAt(i)).isTrieLeaf = true; //if it's the last word in the trie, change that value to true.         }      }  }   The problem occurs when I test them (ex trieInsert("cat")), I always get a null pointer exception at each if statement, but I was under the assumption that you could use null as a comparison in this manner, and you could set objects equal to null in this case?  Example Test  public class main {      public static void main(String[] args) {         TrieNode Trie = new TrieNode();          Trie.trieInsert("cat");      }  }   Am I missing something, and if so what can I do to fix it.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Let $(X,d)$ be a compact metric space. Let $f:X\rightarrow X$ be such that $d(f(x),f(y))=d(x,y)$ for all $x,y\in X$. Show that f is onto. Hint: Fix $y\in X $and $ x_1\in X$, define $x_n=f(x_{n-1})$, observe that $d(x_n,x_{n+k})=d(y,x_n)$.  It is easy to show that  \begin{align*}  d(x_n,x_{n+k})&=d(f(x_{n-1}),f(x_{n+k-1})) \\  &=d(x_{n-1},x_{n+k-1})\\  &=d(x_{n-k},x_n) \end{align*} I don't understand how we get  $d(y,x_n)$.Why $y$ must be an element in $x_n$?

Possible Duplicate:          Let $X$ be a compact metric space and $f$ be an isometric map from $X$ to $X$. Prove $f$ is a surjective map.


I am trying to prove without any galois theory that, for a finite field $K$, there exists irreducible polynomials of arbitrarily large degree. There are answers using Galois theory on MSE, e.g.  My current thought is as follows, although I am uncertain as it seems too simple: Suppose all irreducible polynomials are degree $\leq n$, then as our field is finite, we can enumerate all the irreducible polynomials $P_1, ... P_s$. We then consider $G=\prod_{j=1}^{j=s}P_j +1$. Next, as $K$ is a field, $K[X]$ is a euclidean domain, and hence a PID, and therefore a UFD. In a UFD primes and irreducibles are equivalent. Therefore, if $G$ is not irreducible, we can factor it as a product of powers of $P_1, ..., P_s$. Without loss of generality, suppose $P_1$ divides $G$. Then we can write $G=P_1f$, and $1=P_1(f-\prod_{j=2}^{j=s}P_j)$. However, as $K$ is a field, and therefore also an integral domain, clearly $P_1$ cannot have an inverse as by definition an irreducible element is not a unit. (for context, I came across this question in a past paper for our introductory course on Groups Rings, and Modules. We haven't covered Galois theory*, and normally questions for the irreducibility of polynomials we are expected to use eisenstein's criterion, Gauss' lemma and elementary arguments. *for example, terms like 'splitting field' and 'field extension' are not defined in the course. Also for context: I switched into the second year of a maths degree from economics, and am not particularly confident with abstract algebra compared to areas like real analysis and statistics , so apologies if this is an unintelligent question) Thank you very much for your help :)

I can intuitively understand that there are infinitely many irreducible polynomials in $\Bbb{F}_p[X]$, where $p$ is a prime number, but I'm having a hard time actually proving it. What proof strategy should I take for this?


i am not getting the desired regd_num and name i want regd_num as 567 but it shows 67 and similary in case of name i want raj but it shows C can you please help me how to read the strings properly in an union  #include<stdio.h>  union student{     int reg;     char name[20];     int marks[10];  };  int main() {     union student s;     int i;     float avg,sum;      printf("Enter the register number:");     scanf("%d",&s.reg);     printf("\nEnter the name:");     scanf("%s",s.name);     printf("\nEnter the marks:\n");     for(i=0;i<3;i++)     {         scanf("\n%d",&s.marks[i]);     }     sum=s.marks[0]+s.marks[1]+s.marks[2];     if(s.marks[0]>=0&&s.marks[1]>=0&&s.marks[2]>=0)     {         if(s.marks[0]>=40&&s.marks[1]>=40&&s.marks[2]>=40)         {             avg=sum/3;             printf("\nRegd.No:%d",s.reg);             printf("\nName:%s",s.name);             printf("\nPercentage: %0.2f",avg);         }         else             printf("Grade is Failed");     }     else         printf("Invalid mark. Mark should between 0-100"); }

Is there any good example to give the difference between a struct and a union? Basically I know that struct uses all the memory of its member and union uses the largest members memory space. Is there any other OS level difference?


I try to display the help pages of unset command line , i get as a result the following output:  No manual entry for unset  I see  since they are  similar , however , it cannot be solution for this issue . Indeed , that issue has been resolved by installing some packages using this cmd : sudo apt-get install manpages-posix manpages-posix-dev  So , i try to do the same thing ;except modifying posix by unset , so i do this : sudo apt-get install manpages-unset  The result was :  Unable to locate package manpages-unset  The  explicit question is : How to display manual of unset

I use the man command all the time when I want to get information about a specific command. But this doesn't help me too much when that specific command is a shell builtin. For example:  man cd   returns:  No manual entry for cd   My question is: it is possible to make man also work for all shell builtin commands (like cd, alias, history, etc.),  and keywords (like if, while, [[, {, etc.)?


(a) Suppose p and q are points on the unit circle such that the line through p and q intersects the real axis. Prove that if z is the point where this line intersects the real axis, then   $z=\frac{p+q}{pq+1}$  (b) Let $P_1P_2...P_{18}$ be a regular 18-gon. Prove that $P_1P_{10}$, $P_2P_{13}$, and $P_3P_{15}$ are concurrent.   As for (a), I knew that z must be real given that it is on the real axis. Also, I can use the collinearity equation $\frac{v-z}{u-z} = \overline{\left(\frac{v-z}{u-z}\right)}$ and plug in values p, q, and z. Given that z is real, $\overline{z}=z$ so our equation for collinearity is now $\frac{v-z}{u-z}=\frac{\overline{v}-z}{\overline{u}-z}$. Past here I'm not really sure.  As for (b), I believe I need to use something from what is proved in (a) and therefore have not made any progress. Any help would be much appreciated!

(a) Suppose $p$ and $q$ are points on the unit circle such that the line through $p$ and $q$ intersects the real axis. Show that if $z$ is the point where this line intersects the real axis, then $z = \dfrac{p+q}{pq+1}$.  (b) Let $P_1 P_2 \dotsb P_{18}$ be a regular 18-gon. Show that $P_1 P_{10}$, $P_2 P_{13}$, and $P_3 P_{15}$ are concurrent.  I have gotten nowhere on this problem, but I have a hint:  One of those three segments is more interesting than the other two. Which one, and why? And how can you use that fact to make part (a) relevant?  Any help is appreciated!


I used a translator.  Please understand if I wrote the wrong sentence  I think the last question is difficult to understand. So I Attached was a picture.  The problem of the picture 1 and 2. I want to resolve, as the third picture.  And fourth and fifth picture is a way to resolve in a soft image. So I want to know that possible a blender  tool solve same problem.  I'm sorry to bother you. But I'm really need your help.    I used translator.  Photo 1 problem occurred twice.  I want to solve as picture 3  The Softimage picture is 4 to 5 times.  4 Blender 5 times as possible too.  The request help.

Is it possible to draw a line between intersecting objects? With my current setup, it won't draw anything between them.


I've add a constraint on my table named cours a few days ago with mysql. the problem is that i want to delete the constraint and I don't remember the constraint's name I've used. When I want to delete the constraint they ask me to check if it exist  ALTER TABLE cours DROP FOREIGN KEY idEtudiant;   I expect my constraint to be removed but they say that is not exist

In MySQL, how do I get a list of all foreign key constraints pointing to a particular table? a particular column? This is the same thing as , but for MySQL.


How do you show that two matrices are similar? I know that if they are similar, then B=(v^-1)AV, but how do you find V^-1 and V? For example, the matrices {[1,2]T, [3,2]T} and {[0,4]T, [2,2]T}, how would you find the P and P^-1 (if they are similar)? Or would you have to show they are similar in a different way?  Thank you!

I have two $2\times 2$ matrices, $A$ and $B$, with the same determinant. I want to know if they are similar or not.  I solved this by using a matrix called $S$: $$\left(\begin{array}{cc} a& b\\ c& d \end{array}\right)$$ and its inverse in terms of $a$, $b$, $c$, and $d$, then showing that there was no solution to $A = SBS^{-1}$. That worked fine, but what will I do if I have $3\times 3$ or $9\times 9$ matrices? I can't possibly make system that complex and solve it.  How can I know if any two matrices represent the "same" linear transformation with different bases?  That is, how can I find $S$ that change of basis matrix?  I tried making $A$ and $B$ into linear transformations... but without the bases for the linear transformations I had no way of comparing them.  (I have read that similar matrices will have the same eigenvalues... and the same "trace" --but my class has not studied these yet. Also, it may be the case that some matrices with the same trace and eigenvalues are not similar so this will not solve my problem.)  I have one idea. Maybe if I look at the reduced col. and row echelon forms that will tell me something about the basis for the linear transformation? I'm not really certain how this would work though? Please help.


I've installed Ubuntu recently and I've been trying to install some programs using apt-get but it never seems to work, not even apt-get update works, here's what I get when I try to install something, in this case: java's jdk-7 using:   apt-get install openjdk-7-jre-headless   here's what I get:  Reading package lists... Done Building dependency tree        Reading state information... Done The following packages were automatically installed and are no longer required:   linux-headers-3.2.0-29 linux-headers-3.2.0-29-generic-pae Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 24 not upgraded. mkhas@mkhas-Inspiron-3520:~/Downloads$ sudo apt-get install openjdk-7-jre-headless Reading package lists... Done Building dependency tree        Reading state information... Done The following packages were automatically installed and are no longer required:   linux-headers-3.2.0-29 linux-headers-3.2.0-29-generic-pae Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   ca-certificates-java icedtea-7-jre-jamvm java-common openjdk-7-jre-lib tzdata-java Suggested packages:   default-jre equivs sun-java6-fonts ttf-dejavu-extra fonts-ipafont-gothic   fonts-ipafont-mincho ttf-telugu-fonts ttf-oriya-fonts ttf-kannada-fonts   ttf-bengali-fonts The following NEW packages will be installed:   ca-certificates-java icedtea-7-jre-jamvm java-common openjdk-7-jre-headless   openjdk-7-jre-lib tzdata-java  0 upgraded, 6 newly installed, 0 to remove and 24 not upgraded.  Need to get 44.1 MB of archives.  After this operation, 63.5 MB of additional disk space will be used. Do you want to continue [Y/n]? y  WARNING: The following packages cannot be authenticated!    openjdk-7-jre-lib ca-certificates-java tzdata-java java-common openjdk-7-jre-         headless   icedtea-7-jre-jamvm Install these packages without verification [y/N]? y 0% [Connecting to lb.archive.ubuntu.com (91.189.91.13)]    And it just get stuck at 0%  Edit: Yes, the internet is working fine on my system.  One thing I tried is changing the mirror server from which it's supposedly retrieving the packages from lb.archives.ubuntu.com to archives.ubuntu.com in /etc/apt/sources.list but it says that that file is read only and I can't make any changes to it.  I tried updating apt-get through   apt-get update    but I get this whenever I try to do that:  E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied) E: Unable to lock directory /var/lib/apt/lists/ E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   EDIT: Issue resolved, I wasn't using sudo apt-get update and was only using apt-get update

I get this error whenever I try to install programs using the terminal:  home@ubuntu:~$ apt-get install myunity E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   Also I'm unable to install updates using the terminal.


I have a system  $$ \begin{cases} x_1'(t) = -x_2(t) \\ x_2'(t) = -x_1(t) \end{cases} $$  I have found the linearly independent solutions  $$ \begin{split} \vec{x}(t) &= e^{\lambda_1 t} \vec{v}_1 = e^t \begin{pmatrix}-1 \\ 1\end{pmatrix}, \\ \vec{x}(t) &= e^{\lambda_2 t} \vec{v}_2 = e^{-t} \begin{pmatrix}1 \\ 1\end{pmatrix}. \end{split} $$  and the general solution  $$ \vec{x}(t) = c_1 e^t \begin{pmatrix}-1 \\ 1\end{pmatrix} + c_2 e^{-t} \begin{pmatrix}1 \\ 1\end{pmatrix} $$  Is it correct that both all the linearly independent solutions and the general solution are all named $\vec{x}(t)$ or should the linearly independent solutions be named $\vec{x}_1(t)$ and $\vec{x}_2(t)$?  Now I have to find the solution to which $x_1(0) = -1$ and $x_2(0) = 1$. How can I do this? I know I have to choose the correct values of $c_1$ and $c_2$ in order to fulfil the conditions. But I don't know where to substitute $x_1(0) = -1$ and $x_2(0) = 1$.  In my system, I have $x_1'(t)$ and $x_2'(t)$ but these are not vector function although I only have found vector functions as solutions. Is it because my general solution $\vec{x}(t)$ consists of the functions $x_1(t) = -c_1 e^t + c_2 e^{-t}$ and $x_2(t) = c_1 e^t + c_2 e^{-t}$, so I just have to find $c_1$ and $c_2$ such that $x_1(0) = -c_1 e^0 + c_2 e^0 = -c_1 + c_2 = -1$ and $x_2(0) = c_1 e^0 + c_2 e^0 = c_1 + c_2 = 1$, resulting in $c_1 = 1$ and $c_2 = 0$?

I have a differential equation system  $x_1'(t) = -x_2(t)$  $x_2'(t) = -x_1(t)$  I see that I can write $\dot{x} = Ax$ where  $A = \begin{pmatrix}0 & -1 \\ -1 & 0\end{pmatrix}$  The complete real solution will be  $x(t) = c_1 e^{-t} \begin{pmatrix}1 \\ 1\end{pmatrix} + c_2 e^t \begin{pmatrix}-1 \\ 1\end{pmatrix}$  where $c_1,c_2 \in \mathbb{R}$.  It this correct?  Now I need to find the solution such that $x_1(0) = -1$ and $x_2(0) = 1$.  How can I do this?  I think I could split my complete solution in  $x_1(t) = c_1 e^t - c_2 e^{-t}$  and  $x_2(t) = c_1 e^t + c_2 e^{-t}$  and then find $c_1$ and $c_2$ by solving $x_1(0) = -1$ and $x_2(0) = 1$ with respect to $c_1$ and $c_2$ and finally substitute these values in the complete solution $x(t)$.  Is this correct?


I'm working on a laptop running Windows 10 Home.  I'd like to take advantage of the fast internet connection I'm on to download an ISO of Windows 10 Professional to install later on another machine.  The  doesn't offer the option for Professional, only Home.   The  doesn't seem to exist any longer.    I disagree @magicandre1981 that my question is a .  The answer to this post is no longer valid - the solution link ending 'Windows10ISO' now redirects to the media creation tool, and it was apparent from my question that I already knew of the creation tool's existence.  My question related to confusion as to the availability of Windows 10 Pro through this tool.  The user interface in the previous question has since been redesigned (in a bad way) - I notice it used to say 'Windows 10 editions below are valid for both Windows 10 Home and Windows 10 Professional'.  If it still said that in the media creation tool, my question wouldn't have arisen.

I need to repair my Windows 10 installation. Where can I get a clean ISO (with install.wim, no Install.ESD, so that I can run DISM against the WIM) of the specific Windows 10 build required for this?  In my case, I need the Anniversary update (Build 14393), Creators Update (Build 15063) or Fall Creators Update (Build 16299.15).


I am making spell templates for 5th editions standard distance rules, and I am puzzled on cones. How do you map large cones on a grid using the standard diagonal squares = 5ft rule?   I am mostly confused as to when the width equals the distance. The PHB just says "A cones width at a given point along it's distance is equal to that points distance from the origin.". I assume it is either the mid or end point, but either one has issues. If I choose the mid point it makes the cone huge, if I choose the end point the shape is off.   Either way, I know things like this are kept vague on purpose, but this seems a little to vague.

I am trying to get a precise set of measurements for cone-shaped areas of effect so that I can craft a physical template to use as an overlay when playing with miniatures. I want to get it right the first time.  The problem is that the rules for the shape of a cone AoE aren't very precise, and when you start looking at them closely, there are a bunch of inconsistencies. These are “good enough” when playing without a grid, or when , but they are causing me difficulties with crafting an accurate physical template.  There are three incompatible interpretations of the maximum length of a cone (PHB, p. 204; emphasis mine):     A cone's area of effect specifies its maximum length.   … which each lead to slightly different template constructions (using a 30' length as the working example):   You can use the maximum length as the centreline of an isosceles triangle.  This would give a template that has a centreline 30' long, but edges beyond the “maximum” length that are ~33.5' long. The end of the area of effect would be a flat plane. This shape would encourage players to aim off-centre to use the “bonus” length offered by the edges. You can use the maximum length as the edges of an isosceles triangle.  This would give a template with no portion farther than the maximum away, but with a centreline length that is only ~27.8'. The end of the area of effect would be a flat plane. This shape would motivate players to do off-centre aiming in order to get full use of the maximum-length edges of the template.  You can use the maximum length as a radius of a conical section of a sphere (a ).  This would result in a template with a rounded end, with all points on that arc exactly the maximum length away from the point of origin.   Which of these interpretations of the definition of a cone's area of effect is the correct one to base my template design and construction on?


I'm new to using Ubuntu and I've never really heard of the program so I know nothing about it. I had regular windows when I bought this computer, but had a major file corruption and my boyfriend's uncle completely wiped my software replacing it with Ubuntu. All that aside, I really need a program that works just as well as Microsoft Silverlight for work so I can get my schedule to show up through Dayforce. I've googled somethings hoping to help, but it seemed very complicated and I am not very knowledgeable about this stuff. Can anyone explain what to look for and how do I need to install it?

I need Silverlight installed on my Ubuntu system, so that I can see some of the Microsoft websites(mainly videos).  Are there any alternatives to Silverlight in Ubuntu? If so, what are they and how do I install them?


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 am using Windows 10. For a few days now, this keeps happening, even after a few restarts.  There is a window, slightly larger than the default size of cmd, that appears for less than a second, about once every hour. It shows up, but doesn't stay long enough for a name to appear (even if it did, I wouldn't have the time to read it), or for any content (except for the white background) to show up.  This reminds me a lot of C# Console programs lacking any sort of Console.ReadLine() or Console.ReadKey(), that show up and disappear instantly when debugging.  I can't find anything out of the ordinary in the processes (including background and "show processes for all users".  The window is mostly annoying because it takes away my current focus, because as would most pop-ups do, it seems to take focus when appearing, then I have to refocus in what I was doing. This is particularly annoying in some games, like Starcraft II, where the pop-ups forces me out of the game, and I have to alt-tab back in, and that can hurt a match a lot if the timing is bad.  I'm looking for a way to identify which program is creating this window (maybe it's a virus, maybe it's just a bug in something on my computer), in the hopes of figuring out how to stop it.

I have windows 10 home and from time to time I see a command line window popping up for less than a second. I want to find out which process is causing that. It's not very often that this window pops up so I need some tool that can run for a long time.  Does anyone have a good idea?  Regards Tobias


I've never thought about it but now that I  think of it..   In this conversation for example :  Person A : thanks for coming.  Person B : no problem.We fishermen have all the time on our hands right now. There're so few fish these days, you would think the sea was dead.  To who refers the " you would think " ?  The conversation partner (A) ? But that is just what B think why would (A) think that ?   People always use "you" instead of "I" when speaking their minds to someone even if they're talking about themselves. Why?    " A: Why do you you go that place?   B: that place is the best place in the world YOU don't get bored there there's always something to do." Why not I don't get bored?

My wife was discussing pudding consistency this morning and used a sentence along the lines of, "I only like the pudding you make". I blinked and asked if she really liked the pudding I make and she replied, "No, I mean the pudding you make, you know, like if I were to make some pudding". She was using the "you" in a sense of a hypothetical person, I guess, like saying, "That's what you do in a crisis" when commenting on a riot scene in the news. You're not using "you" to refer to the person you're speaking to, but rather a form of general humanity.  Anyhow, is there a term for such a usage such that you might be able to answer, "Oh, sorry, I was using 'you' in the [term] context, not referring to you specifically"?