im trying to show that $D_6  \cong D_3\times \mathbb Z_2$ as groups.  $D_n$ is the is the dihedral of order 2n  I know that it is possible to form all of the points in $D_6$ and in $D_3$ as compositions of $R$ the rotation operation (such that every vertex move one to the left) and T the reflection on one of the symmetry axis, so i tried to write it done and joining point that act the same, but for no use.


When someone asks me, for example, to go with him to the cinema and I want to reply that I can't because I have to go to the doctor's, what should I say?   I'm visiting a doctor  I'm going to visit a doctor  I will visit a doctor..    My question is when we should use  be going to be + present continuous Will ?  Which one is the most correct option in the provided context?


How to calculate Camera “correct” position and distance to Frame all my Scene?

Consider I have N dynamic points on my Scene, I would like to "frame" all them, with my Camera.    How can i calculate (at runtime) Vector3 Position to correctly frame all my scene ?   This is my idea:   Calculate Avarage for all my points Move my Camera "up" / Zoom out to correctly "frame" all my points (i don't know how to calculate ) Use Unity LookAt(myAvaragePoint)   I think i've to use some trigonometryc function to calculate the Y Camera position (to zoom in, zoom out), but i don't know which!  Thanks


I barely made it through the forced battle and he seems to have gotten significantly stronger now that he's just sitting around.  It does seem like I should be able to beat him without doing the actual mission, since he's not invincible, he's just very strong.    Should I just come back after I beat the game or is it feasible much earlier than that?


Why Don't the Weasleys Use Transfiguration to Improve Their House?

I am probably missing something obvious, but why wouldn't the Weasleys use transfiguration spells to improve their shabby house (or get someone to do this for them)?


Is it possible to join these tables a view and combined columns?

I currently have a few tables that look like this:  create table Actors (ActorID    varchar (20) primary key not null, FirstName   varchar (35) null, LastName    varchar(35) null, "Address"   varchar (30) null, Country varchar (30) null, "State/Province"    varchar (30) null, PhoneNumber varchar (15)  null );   go      insert into Actors     values ('A-63','Tom','Hanks','4332 Whalibee Way','US','Washington','555-619-9905') ,     ('A-42','Sandra','Bullock','63 Sharridon Ave.','US','Texas','329-556-3030'); go  create table Director     (   DirectorID  varchar (20) primary key not null,     FirstName   varchar (40) null,     LastName    varchar(40) null,     MovieID varchar(20) foreign key references Movies (MovieID) null,     "Address" varchar ( 30) null,     Country varchar (35) null,     "State/Province"    varchar (35) null,     PhoneNumber     varchar (15) null     ); go      insert into Director values     ('D700','David','Speilberg','MO-57','9000 Cheque St','US','California','432-553-2267'),     ('D-900','William','Bruckheimner','MO-31','68585 lava lane','US','California','519-242-2543'); go  create table Producer     (ProducerID     varchar (20) primary key not null,       FirstName   varchar (40) null,     LastName    varchar (40) null,     MovieID varchar (20) foreign key references Movies(MovieID) null,     "Address"   varchar (30) null,     Country varchar (35) null,     "State/Province"    varchar (35) null,     PhoneNumber varchar (15) null     );     go      insert into producer values      ('P-123','RJ','Abrams','MO-57','45 Canterbelly Cres.','US','California','556-876-4134'),     ('P-82','Malcolm','Brooks','MO-62','678 Undertree rd','US','Arizona','897-332-6633'); go  Create table Movies  ( MovieID varchar(20) primary key not null,     MovieName   varchar (40) null ,     "Type"  varchar (20) null,     Rating  varchar (20) null,     Director    varchar (35) null,     Producer    varchar (35) null,     MainActor1  varchar (35) null,     MainActor2  varchar (35) null,     SupportingActor1    varchar (35) null,     SupportingActor2    varchar (35) null,     ReleaseDate Date null,     Description varchar(500) null     );     go      Insert into Movies (MovieID,MovieName,"Type",Rating,Director,Producer,MainActor1,MainActor2,SupportingActor1,SupportingActor2,ReleaseDate,"Description")     values ( 'MO-150','The Legend Of Zelda','Fantasy','R','','','','','','','July 23 2018',''),     (   'MO-216','The SQL Games:Replication','Science Fiction','PG','','','','','None','','March 20 2020',''); go   current Format: Robert  Downey JR. FirstName| LastName Ben        Affleck Christian    Bale Will         Smith Charlize     Theron Angelina     Jolie Jessica      Alba Cameron     Diaz Jennifer    Anniston Bradley     Cooper Sandra       Bullock Leonardo    DiCaprio Matt        Damon Chris        Hemsworth Tom         Hanks Mila      Kunis Scarlet   Johansson Emma      Stone Julia     Roberts  Now I have a Table for Actors, Directors and Producers as well as a Movie table, all with their own ID columns and a MovieInfo table with foreign keys to link them.   I was wondering if there was a way to make a view that would take the first and last names and put them together in 1 column for the Actors,Producers,Directors and Movies column and have them joined.  So the table would look like this:  Actors(col1)   Producers(col2)   Directors (col3) Movies(col4)  (Sandra Bullock) (RJ Abrams)   (David Speilberg) (Late For Class)  Any help is greatly appreciated. I know if it was possible to do a view as such, it'd probably be very complicated.


Extension of linearly independent set to a basis in an infinite dimensional vector space

Is it always possible to extend a linearly independent set to a basis in infinite dimensional vector space?  I was proving with the following argument: If S is a linearly independent set, if it spans the vector space then done else keep on adding the elements such that the resultant set is also linearly independent, till it spans the vector space . But the problem is how can we guarantee that the process will stop?


Getting Error: "Malformed entry 59 in list file /etc/apt/sources.list"

I am getting this error:  an error occurred please run the package manager from the right click menu or apt-get in terminal to see what is wrong. The error message was; Error:opening the cache(E:Malformed entry 59 in list file /etc/apt/sources.list(Component), E: the list of sources could not be read.) This usually means that your installed packages have unmet dependencies.


Where does the excess positive charge in a conductor reside?

I have read the other questions on the site and my book uses Gauss' Law to prove that the charge would remain on the surface. While for a negative charges I do agree (electrons) that they will remain on the surface due to inter electronic repulsion, I don't understand why for positive charges the whole conductor wont have an uniform positive charge density. I am looking for a physical description of the inner working of the conductor without any mathematics (perhaps along the lines of chemical bonding itself).  My question succinctly would be why not a positive charge density throughout the conductor and not only on the surface?


This question is not being answered because it appears to be a duplicate.  However, the answers provided for the other post on blow outs seem to apply to artisan breads.  I have never added moisture to my oven nor slashed my loaves when baking a yeast bread in a loaf pan nor has it ever been suggested in any recipes I have followed.  Please reconsider my question.  Thank you. I bake yeast(not artisan or sourdough)in a loaf pan on a lower rack in a preheated 375 degree oven.  When I get a lovely oven spring, I also tend to get an ugly blowout.  I think my ingredient ratios are in line as I follow the recipes but also use "feel" to guide the end result:  Not too stiff but slightly on the sticky side.  I use a stand mixer for most of the kneading and then finish with gentle hand kneading.  I shape the loaves gently by hand and make sure the seams are all tucked into the bottom.  I try to adhere to the recommended rise times as well.  What am I doing wrong?


How does spacecraft/rockets accelerate in vacuum while there's no gas present to apply force on in order to accelerate?

I don't know maybe it's a very stupid question I'm asking but that's the question which always disturbed me.


In the Steam Auction, every Steam item (card, booster pack, background and emoticon) has a gem value, which is awarded when the item is "recycled" (user clicks the Turn into Gems... button).  How is that gem value worked out? Is there some sort of biasness for rare items? Valve-made items?    I've noticed that all the sale emoticons/backgrounds are worth 100 gems each, along with items from Valve games^, free-to-play games and sales, while all other games only reach a maximum of 80.  ^CS:GO somehow fits this rule, but Half-Life 2 doesn't.


Finding integral of function involving fractional part of x

The integral given is: $$\int_{0}^{1}\big\lbrace\frac{1}{x}\big\rbrace \big\lbrace\frac{1}{1-x}\big\rbrace \big\lbrace1-\frac{1}{x}\big\rbrace dx$$ where  $\big\lbrace x\big\rbrace$ represents the fractional part of $x$  I first tried breaking it using a piecewise definition but I couldn't figure out how to do it as there wasn't any consistent pattern that I could spot.   I tried graphing it to get an idea but that also didn't get me anywhere.  Finally, I tried using the property of definite integral that $\int_{0}^{a}f(x)dx=\int_{0}^{a}f(a-x)dx$ but the first and seccond terms remained the same and the last term changed but not it did not lead to any noticeable changes.  I am stuck now. Any help would be appreciated.


why can't electromagnetic waves make through holes that are smaller than the waves wavelength

There's this theory that  electromagnetic waves can't make through holes that are smaller than their wavelength its supposed to be how microwaves stop microwave radiation from coming out... But that doesn't make sense. I mean it would make sense if the theory said that em waves couldn't make through holes smaller than the amplitude of the wave but I just don't get how the wavelength affects the passing of the wave through holes. So can anyone explain this to me. It would be great if you could explain it to me using funder mental electromagnetic equations or maxwells equations but Anything would be helpful... Thanx in advance


I'm a stay-at-home person—but who  isn't these days?

Should I be using "who" or "whom" in this sentence? How would I form the deep structure of this sentence? Is it "These days, a stay at home person is not whom"?


18.04 on MSI GE63 - boot hangs at 'Loading initial ramdisk' without `acpi=off`

I've been trying to get Ubuntu 18.04 LTS running on my new MSI GE63 Raider. I can get into the live USB by passing acpi=off and then running the installer. After that, I install the proprietary nvidia driver (nvidia-driver-390). Also I have tried installing nvidia-prime and bumblebee. I've also blacklisted nouveau.  The issue is that I cannot for the life of me get it to boot without passing acpi=off, because otherwise it hangs at a purple screen. When trying in recovery mode with any of the included kernels (4.15.0-20 and 4.15.0-29) I can see it hangs at   Loading initial ramdisk.   In addition to the above I tried passing following parameters in GRUB:   acpi=ht acpi_osi= acpi_osi=! acpi_osi="Windows 2009" acpi_osi=! acpi_osi="Linux" nomodeset nogpumanager   ... and a couple more (I forget after trying so many)  The specs of this laptop are:    intel i7 8750h (6 core) nvidia gtx1060m 16gb of RAM 256gb ssd (which holds the windows 10 partition and the "/" 1000gb hdd (which holds the data for windows and "/home"   The BIOS settings are set to UEFI. Fast boot and secure boot are both disabled. I've also tried switching off Intel speedstep and c-states, both to no avail.  Also, I have tried to install Debian 9, Lubuntu 17.04, Ubuntu 16.04 LTS, Deepin 15.5 and Mint 18, all of which need the added acpi=off flag.  Does anyone have any advice for this?  Thanks in advance!


How can I take a photo using a slow shutter speed without it being overexposed?

When I try to take a picture using a slow shutter speed in daylight it is overexposed. How can I change the settings so it isn't overexposed?


Want to delete a vector from another vector in C++

I am trying to delete a vector list from another vector list but the program stops responding as soon as I reach the specific part of the program.Here is the program:  #include<iostream> #include<vector> #include<iterator> int main(){     using namespace std;     vector<int> a(5);     int ints[3] = {2,3,5};     vector<int> b(ints,ints+3);     for(int i=0; i<5; i++){         a[i] = i+1;     }     vector<int> :: iterator pra;     vector<int> :: iterator prb;     cout << "initial list:";     for(pra = a.begin(); pra!=a.end(); pra++){         cout << *pra << " ";     }     cout << endl;     for(pra = a.begin(); pra!=a.end(); pra++){         for(prb = b.begin(); prb!=b.end(); prb++){             if(*pra == *prb){                 cout << *pra << " ";                 a.erase(pra);                 b.erase(prb);                 break;             }         }     }      cout << " Final List:";      for(pra = a.begin(); pra!=a.end(); pra++ ){         cout << *pra << " ";     }  }


Why " provided $t$ is not in $\theta$ " at the end of the definition of $\forall $ Intro Rule ? ( Shapiro's Entry On Classical Logic in SEP)

Here is the passage :  "The introduction clause for the universal quantifier is a bit more complicated. Suppose that a sentence θ contains a closed term t, and that θ has been deduced from a set of premises Γ. If the closed term t does not occur in any member of Γ, then θ will hold no matter which object t may denote. That is, ∀vθ follows. (∀I)  For any closed term t, if Γ⊢θ(v|t), then Γ⊢∀vθ provided that t is not in Γ or θ".  First point : Something I do not understand is that the preliminary remark suggests that $t$ is contained in $\theta$ while the official statement of the rule requires this  not to be the case. Second point : Also, should we not have : If, for any closed term $t$,  $\Gamma |-\theta(v,t) $, then $\Gamma |- \forall v\theta$ instead of For any closed term t, if Γ⊢θ(v|t), then Γ⊢∀vθ ? I mean, in order the universal statement to be deduced, should it not be required that the substitution works for any closed term? ( It seems to me that in the official rule,  " for any closed term" applies to the whole conditional, not to the antecedent in particular.) Does the alternative reading I suggest make any difference? What do I miss?


Why are the close buttons broken on snap apps?

All snap apps seem to have broken close buttons. This can be seen for the Gnome System Monitor and Gnome Calculator. Apps installed via apt look good (Gedit and Gnome Terminal). Is this a known problem for Ubuntu 19.10?    echo $XDG_CURRENT_DESKTOP  sadf   gsettings list-recursively | egrep "gtk-theme|icon-theme"  org.gnome.desktop.interface icon-theme 'Adwaita' org.gnome.desktop.interface gtk-theme 'Adwaita'


Weird situation - using quotes as nouns and making them plural (APA format)

I'm in a strange situation where I need to take two short phrases and make them into plural nouns.  Here's the context:     His was the destabilizing blow in a long bombardment of Why Latin?’s and waste of time’s.   The "Why Latin's" and "waste of time's" are obviously the problem.  Do I italicize them?  Use quotes?  And how do I make them plural?  Do I use apostrophes?


Element invertible in integral extension of ring implies invertible in ring

Please excuse some minor hiccups in terminology, I am primarily reading this in Swedish so feel free to correct any.     Let $A\subseteq B$ be an integral extension and $\alpha\in A$ an invertible element in $B$. Show that $\alpha^{-1}\in A$.   This is the question I am currently struggling with. I know that $\alpha\in B$ from the question, which means that there exists a monic polynomial $p\in A[x]$ such that $p(\alpha)=0$. I have also considered that $p(x)=x-z=0$ with $z\in A$ would naturally always imply that $x\in A$, but other monic polynomials can also do that, so I feel it doesn't contribute anything of real substance.  So I am primarily struck on how to approach this to reach the answer; any advice?


The expression `\bf{\textbackslash [ formulae \textbackslash ]}`   the result is     The expression ‘[ formulae ]’   (don't mind for not showing the '\' expressions in the result. That's not a problem ;) )  Always the second, or closing single quote being bold.  I don't know why this happens even though the quote is outside of the \bf command :(


How to solve "ima: error communicating to tpm chip" messages during boot

I am getting the following error message as a list of 4 or 5 lines with differing numbers at the beginning of each line during boot for a long while:  ima: error communicating to tpm chip   I am using Ubuntu 19.04 (though this error was existing for a while at the older versions) and my computer is a Toshiba Z930.


Various editors like gedit detect if the file is changed and asks to reload it. Sometimes in vim when I got many files to edit, I sometimes end up opening same file in different tabs for quick look with other files and several other reasons.  So is there anyway I can force to reload the current file before I update anything to it.  I know one option is to exit and reopen it, but I have splitted the screen and I don't want to loose that view.


What is the best word to describe the feeling of being nervous, intimidated, excited etc which may be felt upon meeting a person you greatly admire?

Every time I've had the opportunity to meet a moviestar/rockstar who I idolize and imitate in every way (and call it influence), I always flub it up. Without fail. This is because I get so nervous and I want so badly to strike up a rivetting conversation that I lose my ability to talk, or even think. But still, somehow, I muster up the courage to approach my personal epitome of awesomeness, trusting my social instincts will kick in by the time I actually try talking to him. But the closer I appproach, the blanker my mind grows. Eventually I reach a proximity that forces him to acknowledge my intention to speak to him; and so he makes eye contact with me, waiting. I can't just tell him how much I love his music, being just like every other annoying fan. But still... that'd be better than what I was actually being like: some weirdo who walks up and stares with mouth agape and eyes wide, as if staring into the ark of the covenant, manifested in the form of Cedric Bixler the vocalist of 2 revolutionary post-punk/screamo bands as well as half the reason why hipsters wear skinny jeans. It was the most painfully awkward 30 seconds of my life and it took years of psycho therapy to finally heal from the trauma caused by my Oscar winning portrayal of Captain Awkward. But what I'm really needing to know ASAP would be the perfect word and/or phrase to describe that feeling that left me speechless? It was kind of like an amalgamation of being nervous and feeling privileged to be in the presence of such an amazing human being. It's similar to words like intimidated, overhelmed, daunting, honored, umworthy, nerve wracking, mind-blowing, formidable, impressed, flustered, veneration, revery, dazed, bewildered, dumb-struck, and of course, nervous or privileged.  But I feel like there's yet another pseudosynonym that embodies the precise meaning of this word that is lodged within my subconscious state of awareness, beyond the reach of my self-awareness. Whatever that perfectly descriptive adjective is, I'll know immediately upon hearing it. It will possess all the expected connotations, implications, and inspirations that are conjured when I unsuccessfully attempt to recall this ellusive adjective (presumably. It may turn out to be any variety probably combination of words, but used in such a way to describe a complex emotional state) The reason I'm asking is because I have, by a stroke of luck, become engaged in an online conversation with a member of the royal family of a very rich nation. (it is a long term convo: days or weeks btwn replies) noooo it is not the Prince of Nigeria. I was skeptical at first but he seems to only be interested in the human connection and has said nothing suspicious. But I was trying to be appropriately humble as I suspect civilians are expected to be towards royalty in his culture, and I was trying to say that it made me nervous but immensely grateful at the same time to be in conversation with such a person as his lordship. But I juSt could not find the exact right word. Help me to ingratiate this genuinely regal fellow who may possibly become another one of my many friends in high places. Thank you The exact wording of the sentence that I am planning to use this yet to be determined adjective is as follows: "I must admit it is rather  __________ to be conversing with royalty." I might say "a bit" instead of "rather." If I can not find my perfect descriptor, I will just be forced to describe the 2 juxtaposed emotions separately. I've already written a rough draft as a back up just in case the unimaginable happens and it turns out I'm hunting a word that doesn't exist. Here it is: "I must admi it is a bit intimidating to be conversing with royalty. However, it is also a great honor. I feel very fortunate that..." I think using "a bit" makes it less formal. And I don't wAnt to address him as MY prince, but rather A Prince that I happen to be friends with. So I am trying to maintain a careful balance between formal and casual types of parlance


Does each KVM guest require its own copy of the bootable ISO image? If I'm thinking correctly, the guest only needs to read the .iso, not lock it or anything, so multiple guests should be able to use the same ISO. Or am I approaching the problem the wrong way?  Thanks in advance for your time!


What's the most efficient way to farm Pokemon Dollars/money in Pokemon X & Y? I'd love to be able to have a decently sized wallet so I can show it off to others, but mainly to buy tons of Max Repels when venturing through the wild.  I remember how hard it would be in previous Generations.  For example, in Gen V, I remember repeatedly grinding the Elite Four just to make some serious profit, but it took hours of grinding to reach a decently sized wallet.  What's the most efficient way to do so?


Let there be $A,B$ matrices.  Let $C=A+B$  $Span(Col(C))\subseteq Span(Col(A))$ because C is a linear combination of A . $Span(Col(C))\subseteq Span(Col(B))$ because C is a linear combination of B .   Therefore $Span(Col(C))\subseteq Span(Col(A))+Span(Col(B))$ and $Rank(A+B)\leq Rank(A)+Rank(B)$


This new PC that I have was gifted to me, and I am brand new to Ubuntu, and I would rather use windows because it is something that I am used to because I use it for school 24/7. I have been trying to follow along with tutorials on youtube,but whenever there is a certain command, it says that the file isn't there, and I don't know if I have a dual boot computer or not. And the terminal commands that I have tried are either incredibly long or result in an endless void of language that I don't understand. If there is a simpler way to remove my computer of Ubuntu and replace it with Windows 10, that would be greatly appreciated. Thank you.


Why not indicate the username of the OP when they click on "this solved my problem"?  Instead, only "community"  is shown. .


Difference between generalized linear models & generalized linear mixed models

I am wondering what the differences are between mixed and unmixed GLMs. For instance, in SPSS the drop down menu allows users to fit either:   analyze-> generalized linear models-> generalized linear models & analyze-> mixed models-> generalized linear     Do they deal with missing values differently?    My dependent variable is binary and I have several categorical and continuous independent variables.


To avoid oscilloscope ground short, why not simply unground the scope?

We all know what happens when we ground a regular oscilloscope probe at the wrong place: a short. There are two main points to consider:  1) All channels share the same ground plane, so we can't take 2 or more simultaneous measurements referenced to different "grounds".  2) The scope's ground plane is directly connected to the center pin on oscilloscope's AC power cord, which is probably connected to the ground of the equipment we are probing, preventing us from using any other reference than the "official" ground itself, otherwise we will have shorts and possibly fireworks, in more severe cases.  There's nothing to be done about point 1, but about point 2, why not simply disconnect the center ground pin on scope's AC cord and leave it floating? I personally do that with my older scope. When using channel 1 only, I can freely move my ground hook everywhere in my circuit, and I never had any problems, apart from some 60Hz noise, but this is expected, I guess, since the whole scope is floating and subject of all kinds of noise.  So, apart from the increased noise, is that harmful to leave the scope ground floating? What else am I loosing doing things that way? In which situations my practice will bring me serious trouble? Does that damage the scope in the long term?


After load-shedding when I tried to boot into my Ubuntu 20.10, a black screen with this error message appeared. /dev/sdb1: clean, 670021/4890624 files, 10575973/19537408 blocks


How is it possible that I can password lock my terminal. I do not want anybody but me in the terminal. I want it so like when I start up the terminal, it will ask for a password, and if the password is incorrect, it will exit out, or maybe ask again. What are my possible ways I can do this?


Let $k$ be a field. I want to show that $k[x,y]\ncong k[u,v,w]/(uw-v^2)$ as $k$-algebras, but can't find a way to do it.    The dimension of the $k$-vector space generated by the degree 1 monomials are different on both sides, but then it's possible that an isomorphism doesn't preserve the graded parts, right?  Any help will be appreciated.


Shortcut keys to delete all text to end of line (or all text after cursor)?

Edit: This question was marked as duplicate and closed, but I checked the suggested duplicates before asking mine and found they had different particulars, even if they were about the same topic.  If, however, I missed the exact duplicate, then I stand corrected. When deleting all text before the cursor, you could use the keyboard shortcut CMD + Delete, but what's the opposite equivalent when you want to delete all text after the cusor (or to the end of a line)?


String elements in array with whitespaces in them being splitted?

I'm trying to use the next array's elements to replace some strings in a file:  declare -a replacements=($name, $description, $date, $keywords)   By using the search terms in this array:  declare -a searchs=("a.name", "a.description", "a.date", "a.keywords")   The problem is that some variables (description, for example) have whitespaces in them:  declare description = "My name is Jonah"   Which casuses a weird behaviour on the next piece of code:  for ((i = 0; i < ${#searchs[@]}; i++)) do     sed -i -e "s/${searchs[$i]}/${replacements[$i]}/g" "./${directory}/data.txt" done   The for loops uses every word in the string as a replacement instead of the whole string.  Is there a way to fix this error? Thanks in advance!


I'm trying to edit the brightness of my System76 laptop screen from my window manager i3wm. I've tried the following:  xbacklight -dec 10   does nothing  sudo vim /sys/class/backlight/intel_backlight/brightness   Even with sudo, and chmod 777 I can't edit this file. Vim says "Fsync failed" when I try to write to it, and I have plenty of disk space available so that is not the problem  xrandr --output eDP-1 --brightness 0.5   this works, but it modulates brightness in software and doesn't have the increment/decrement abilities I want.


I am building a battery powered device. Almost all of my logic is running at 3.3v, although I do have a 5v supply for a few hobby servos.  I want to measure the battery voltage, but I can't do so directly with the ADC on my controller because the battery voltage (depending on the cell count of the lithium polymer battery that the user connects to the device) can vary between 6 and 36 volts. (My 5V and 3.3V supplies are fine with this input variation already.) The ADC can't measure anything above its supply voltage.  Obviously I need some sort of amplifier with a fractional gain, about 1/12 or so. Should I just use a simple voltage divider? How do I decide what values to use? Maximizing sleep-mode battery life is a concern, so that votes for using large values. What constrains how large those values can be? (The input impedance of the ADC, right?)  Am I better off using some sort of opamp amplifier circuit for some reason?  What's the usual solution here?


Good reference book for quadratic integer rings?

Could anyone direct me to a good reference book(s) for quadratic integer rings? Ideally, the reference would begin with their elementary properties and then proceed through their ring-theoretic properties: for example, which quadratic integer rings are PIDs, which are UFDs, which are EDs, and which are multi-stage EDs. Also, if the reference could connect the subject material to elementary number theory that would be splendid. For example, connecting the primes of $\Bbb Z[i]$ with the primes of $\Bbb Z$ and solutions to Pell's Equation.  I've only read about these rings through books whose main purpose was to introduce the the fundamentals of abstract algebra, and I want a more specialized reference.  Any input is appreciated.


I saw the latest update of QField 1.18 wherein users are allowed to draw/digitize in freehand lines/polygons geometries. I was wondering how can it be enabled in QField? We badly need it in our fieldwork/geotagging activities of natural resources.


I'm trying to get access to root I use the command sudo su-  and others  for my user and it asks for the passowrd. Then when I type, nothing appears on screen. Then if I press enter, it accepts the empty space as password.


Constructing PHP/MySQL search query with variable options

What I'm Trying to Do  I have a SQL table that has a list of job opportunities for a client's website.  I am trying to create a search form but not all the fields will necessarily be filled in.  The possible values are:  title = the title of the job  location = the location of the job  sal1 = the bottom bracket of the desired salary  sal2 = the top bracket of the desired salary  The Code  $query = 'SELECT * FROM `jobs`';  if($_GET['title']!='') $query.= ' AND `title` LIKE %'.$_GET['title']; if($_GET['location']!='') $query.= ' AND `location`='.$_GET['location']; if($_GET['sal1']!='') $query.= ' AND `sal1`>='.$_GET['sal1']; if($_GET['sal2']!='') $query.= ' AND `sal2`<='.$_GET['sal2'];  $stmt=$dbh->prepare($query.' ORDER BY `date` DESC'); $stmt->execute();   The Issue  On paper this method should work, but I would prefer to use prepared statements. The only method of doing this seems to be using mysql_real_escape_string() on each $_GET variable, as I can't figure out how to use execute(array($val1,$val2...)) when I don't know how many variables are in use.  If possible, how can I utilised prepared statements to sanitize the $_GET variables?


Why is the Earth shaped like a sphere and not any other shape: cube, prism?

Why is the earth shaped like a sphere and not any other shape: cube, prism?


I am writing a document about limits of functions. I need to use notation for the lower limit, which I have as the normal limit sign but with 'lim' underlined. I need the same for the upper limit with 'lim' overlined.  For the overlined I have tried to use  \overline{\lim_{x \to 0^{+}}}   but that overlines all of it, I just want it over the 'lim' part.


How can we be sure if Universe has exploded with big bang? Can't it be implosion?

Why do we say the universe has exploded in the event of big bang? When we talk about big bang there was no concept of outside with the absence of space, so should’t the universe be imploded into the big bang from the single point? Also how can we say there was point as presence of point itself means space was already present, does this imply space was already there when big bang happened?


Why is TV remote's infrared wave shown by a camera as purple light, why not red or something else?

I've always seen that all the old model remotes that is used in DVD players or TVs, it emits electromagnetic waves, having wavelength somewhere in the Infrared region. But when my phone's average quality camera (Moto E) is held between the emitter and my eyes, it converts the infrared into visible ones and shows a whitish purple colour. I don't know why always the purple is shown. I'll be very happy if you explain this to me.  Thank you.


Prove that $\gcd(\det(A),26)=1$ if a $2x2$ matrix $A$ with entries in $Z_{26}$ is invertible

Prove that $gcd(det(A),26)=1$ if a $2x2$ matrix $A$ with entries in $Z_{26}$ is invertible.  We know that $A$ is invertible. Let the inverse of $A$ be $A^{-1}=(det(A))^{-1}A^{*}$, where $A^{*}$ is the adjoint matrix of $A$.  However, this is where I am stuck, I cannot see how the formula for $A^{-1}$ is useful.  Any help is greatly appreciated


Word to define person with bad social skills

How would you define a person without (or with very bad) social skills?  I don't mean a totally anti-social, but one that struggles to behave in a social context, and feels awkward or out-of-place when forced to stay and talk with other people.  Maybe that would be anti-social, but not by choice... Just thinking to be rejected/avoided by others, and that keeps trying to relate to others but fails everytime.  Is there a word that could describe this? Or else, what word would be the closest and more appropriate to help explain this?  Altough some answer overlap my question  differs from mine. This question is not about understanding others and their feelings, but rather at behaving in social context, or being marked as a weird/awkward person that's avoided by others.


Proving $(0,1)$ and $[0,1]$ have the same cardinality

Prove $(0,1)$ and $[0,1]$ have the same cardinality.    I've seen questions similar to this but I'm still having trouble.  I know that for $2$ sets to have the same cardinality there must exist a bijection function from one set to the other.  I think I can create a bijection function from $(0,1)$ to $[0,1]$, but I'm not sure how the opposite.  I'm having trouble creating a function that makes $[0,1]$ to $(0,1)$.  Best I can think of would be something like $x \over 2$.  Help would be great.


As I understand this, firewalls (assuming default settings) deny all incoming traffic that has no prior corresponding outgoing traffic.  Based on  and , reverse SSH tunneling can be used to get around pesky firewall restrictions.  I would like to execute shell commands on a remote machine. The remote machine has its own firewall and is behind an additional firewall (router). It has an IP address like 192.168.1.126 (or something similar). I am not behind a firewall and I know the remote machine's IP address as seen from the Internet (not the 192.168.1.126 address). Additionally, I can ask someone to execute ssh (something) as root on the remote machine first.  Could anyone explain me, step by step, how reverse SSH tunneling works to get around the firewalls (local and remote machines' firewalls and the additional firewall between them)?  What is the role of the switches (-R, -f, -L, -N)?


I was having some troubles when trying to set the on click listerner for
 dynamically. Here is my code to populate the list:  for(var i = 0; i < chatlist.length; i++){         $('

' + contact + '

' + preview + '

').appendTo($('#contacts ul'));     }   On click listener for selected row:      $('#contacts').on('click', 'li', function() {         var index = $(this).index();         console.log(index);    });   I am using . Upon selecting row, I wanted to set the selected
 tag to

   I managed to get the selected row index but I not sure how to set the HTML class for selected
. Any idea?


Two apparent contradictions in SR involving time dilation and length contraction

So I've encountered the site "" – a website proposing "alternative" theories to theories in modern physics. Of course, the site claims that both SR and GR are wrong. To show "why" SR is wrong, the author presents two apparent contradictions in SR, as following:           Two accurate identical clocks, A and B, move with uniform motion along a shared straight-line path but with different constant velocities such that the distance between them steadily decreases with time.      [...]      We wish to know which clock runs more slowly.      (Keep in mind A will eventually catch up to B and you don't need to change reference frame by accelerating in order to measure the times side-by-side)   I can obviously see the apparent contradiction – one can claim that A is at rest and B is experiencing time dilation or equally claim that B is at rest and A is experiencing time dilation, giving two different results when the two clocks "meets" – but I have no idea to actually solve it.  When solving this, please use real numbers of your choosing.  The second "paradox" involves a circular particle accelerator with equally spaced electrons. Now, if we'd would speed them up to relativistic speeds, say $\gamma = 2$, how would the tube look like?   (source: )     (source: )     (source: )     (source: )    My own thought on this is that the electrons have a non-inertial motion and thus alternative A must be right (the electrons shrinking but their spacing staying the same). Is this correct a reasoning?


Cardinality of the set of partintions of $\mathbb N$

Given the set of natural numbers $\mathbb N=\{1,2,3, ... \}$. I am interested in partioning $\mathbb N$ into disjoint sets of $K$ elements whose union is $\mathbb N$.     What is the cardinality of this set? Is it equal to the cardinalty of $\mathbb R$?


Search and replace a pattern containing backslashes

I have a file                                bla bla bla bla bla bla bla bla bla bla bla bla bla bla \newcommand{\datestamp}{20180215} bla bla bla bla bla bla bla bla bla bla bla bla bla bla   I need to search for \newcommand{\datestamp} and want to replace a nearby pattern with a new pattern.                          Required output file   bla bla bla bla bla bla bla                                     bla bla bla bla bla bla bla                                                     \newcommand{\datestamp}{20180218}                               bla bla bla bla bla bla bla                              bla bla bla bla bla bla bla     The backslashes are complicating this task. How do I manage?


What is the exact meaning of the "oh so " idiom?

I routinely find this expression in newspaper, magazines, blogs... My guess is that it's used to report a widely shared opinion, but I couldn't find any confirmation of this. Or maybe it's just used to emphasize the adjective? I'm afraid I might be missing a subtelty here.  Here are a few examples from the first page of googling "oh so *":   Paul Ryan's oh-so-clever jab at Jay Cutler Chivas USA came oh so close to getting the first goal of the match The movie-star-handsome [...] stung with that oh-so-direct comeuppance Robert Pattinson Oh So Lonely: 'No One Ever Calls Or Texts Me!'  An Oh-So-British Affair Projects a Fresh, Antique Charm LaPorta made an oh-so-costly error in the game Finally, the long, oh so very long flight back to Vancouver


I heard that a black hole is not black because it's escape velocity is greater than or equals to the speed of light. But instead it is black because the light that gets emitted from a black hole gets red shifted due to the curvature of space-time near that black hole.     Is it true or not?   If it is true then tell me how does light even escape from a black hole to be red-shifted in the first place?


Can I use reflection to instantiate classes that inherit from a generic base class?

I was wondering if there was a tidy way to use reflection to instantiate a bunch of properties in a class, with a constraint that the property types to instantiate should only inherit from certain classes, and what if one of these classes has a generic type parameter.  For example.....  public class Control {     public string Name => "Test Name"; }  public abstract class BasePage<T> { }  public class HomePage : BasePage<HomePage> { }  public class LoginPage : BasePage<LoginPage> {     public Control Test { get; set; } = new Control(); }  public class LoginLinkPage : BasePage<LoginLinkPage> {     public Control Test { get; set; } = new Control(); }  public class UserPage : HomePage {     public Control Test { get; set; } = new Control(); }  public class Pages {     public UserPage UPage { get; set; }     public LoginPage LPage { get; set; }     public LoginLinkPage LLPage { get; set; } }    Is it possible to instantiate all the properties in Pages in a single method? And allow for more properties to be added and instantiated assuming they inherit from either BasePage<T> or HomePage?  This is what I have so far, but it only checks the subclass of the property type is homepage...  class Program {     public static void InitializeControls<T>(T page)     {         var pageType = typeof(T);          var properties = pageType.GetProperties().Where(p => p.PropertyType.IsSubclassOf(typeof(HomePage)));          foreach (var property in properties)         {             property.SetValue(page, Activator.CreateInstance(property.PropertyType));         }     }      static void Main(string[] args)     {         var pages = new Pages();          InitializeControls(pages);          Console.WriteLine(pages.UPage.Test.Name); // "Test Name"         Console.WriteLine(pages.LLPage.Test.Name); // NullReferenceException         Console.WriteLine(pages.LPage.Test.Name);  // NullReferenceException                 Console.ReadLine();     } }   I can't wrap my head around whether it's possible to also do a check for BasePage<T>, if T could be various different types.  I would be open to design changes that might solve this problem.   Thanks,


Unable to locate package kubuntu-plasma5-desktop on 14.04

I am attempting to install kubuntu-plasma5-desktop on Kubuntu 14.04 amd64, following    sudo apt-add-repository ppa:neon/kf5 sudo apt update sudo apt install project-neon5-session project-neon5-utils project-neon5-konsole  sudo apt-add-repository ppa:kubuntu-ppa/next sudo apt-add-repository ppa:ci-train-ppa-service/landing-005 sudo apt update sudo apt install kubuntu-plasma5-desktop   Unable to locate package kubuntu-plasma5-desktop  How can I fix this error?


python 2 simple for loop high memory usage

Testing with Python 2.7 and 3.5  for i in range(0, 1000000000):     pass   When I'm running this code with python3 everything is fine (less than 3MB memory usage)  But by python2 memory usage is 32GB (my server has only 32GB of ram)  How to fix this for Python 2.7?


Microsoft block email for no apparent reason

I manage a couple of servers and 3 of them got flagged the same week by Microsoft and block all email these servers send and we get these errors :     550 5.7.1 Unfortunately, messages from [xxx.xxx.xxx.xxx] weren't sent.   Please contact your Internet service provider since part of their   network is on our block list (S3140). You can also refer your provider   to .   2 of these server are dedicated servers (with WHM) that host around 70-90 clients and the other server is a VPS (with Plesk) for a single client.  On the servers with WHM, I checked the Mail Delivery Reports and I don't see sign of spam. Our abuse@ accounts only got 4 complaints last month.  I checked the reputation of the servers on talosintelligence.com and all servers got a "Good" email reputation.  I made a blacklist check on mxtoolbox.com and they are not listed on any list.  We contacted Microsoft multiple time and they always return us saying that the "IP do not qualify for mitigation at this time" and that they cannot give us more information.  We made multipe tests on glockapps.com, the test email got received without problem with every mail service expect for the ones from Microsoft. For Outlook, live, hotmail the message are never delivered and for Office365, it get spammed.  We have multiple client that call daily to know what is happening and frankly, I just don't know. Everything seems fine and Microsoft doesn't seem to want to help us.  Thank you  EDIT: Got contacted by OVH, Microsoft blocked a bunch of their IPs, so it was not on our side.


Why would the size of /proc/stat show as zero?

ls -rlth /proc/stat -r--r--r-- 1 root root 0 Feb 21 04:25 /proc/stat   Although if we cat it, its got enough contents.


If I make a forge server with mods, do other people need the mod?

I want to make a Minecraft server with mods in 1.11 but do the players need mods as well because I heard from people that they just need forge.


Change Font for part, section, subsection, ... KOMA scrartcl-class

I am using the KOMA scrartcl-class  \documentclass[listof=totoc,toc=sectionentrywithdots,DIV=14]{scrartcl}   Is there a way to change the font-style of the part, section, subsection and subsubsection globally?


Grouping of Drop down list menu in visualforce

Is there a way to group the selectOptions list values on a visualforce page?   Any help would be appreciated..


Is there a O(N) solution to getting top k most occurring string in List?

The problem is: Given a list of strings and an integer k, return the top k most frequently occurring words in descending order based on frequency. This must be done O(N) where N is the length of the list of strings.  The popular solution is to store (word, frequency) in a hash table, sort the hash table by frequency, and output the top k words. This is not O(N) however because sorting by frequency takes O(NlgN).  I'm wondering if a O(N) solution actually exists. I've thought about quick-select where you get the kth top most occurring word and sort the remaining frequencies but that would be O(N + klgk) which is still O(NlgN) when k is say N.


Voting To Close As A Second Dupe Didn't Add A Second Comment

A question gets a close vote as a possible duplicate of X, and the automatic comment shows up.      I then close vote it as a duplicate of Y, but my "Possible duplicate of [...]" comment doesn't appear.    Question: Is this expected behavior?        Edit:   I want to test it thoroughly here (I might have just gotten mixed up):    But that would mean flagging  as a duplicate of some random question - multiple times!   Is that OK?      Edit:   Maybe it's a duplicate of  , but I am not if that's the same case.   Specifically, my question is:   Was there a different "possible duplicate of.." comment already, when the user tried adding one?   If not, it might be a different bug.


Is it only red, green and blue that can make up any color through additive mixture?

I'm reading about color vision and have some trouble understanding the motivation for why the  was suggested in the first place. The book I'm reading ("Psychgology: The science of mind and behavior") states:     At the beginning of the nineteenth century it was discovered that any colour in the visible spectrum could be produced by some combination of the wavelenghts that corresponds to the colours blue, green and red in what is known as additive color mixture.   From the explanation in the book, it seems like this somehow should be a reason for also supposing that the human retina was composed of cones sensitive to the colors green, red and blue respectively. I guess this would be a valid argument if it was only red, green and blue that, through additive mixture, could make up any color.  Is it only red, green and blue that, through additive mixture, can make up any color?


Get the key with the biggest score in Python

I'd like to know if you know other/better way (without max method) to get a key with the biggest score in a dictionary ? :  report_card = {'french' : 14,             'english' : 12,             'math' : 16,             'chemistry' : 19,             'sport' : 14} max = 0  for subject, score in report_card.items():     if max < report_card[subject]:         max = report_card[subject]  for subject, score in report_card.items():     if max == report_card[subject]:         print(f"The subject with the highest score is {subject} with {score} points")


Hello friends am trying to work on resolving NUllpointer Exception that is being thrown with in this code  public String getInvalidPhoneNumberNotification() {         List<String> errors = getValidationErrors();         String search = "valid phone number";         for (String str : errors) {             if (str.trim().contains(search))              return str;         }         return null;     }  i have read through different ways of how i can get rid of using return null object in order to catch npe but it seems the problem still persits, am using getInvalidPhoneNumberNotification() method reference to handle whether the method is an integer, but the problem is returning null object when its already null, any help will be appreciated


$c\mid ab\Rightarrow c\mid \gcd(a,c)\gcd(b,c),\,$ for integers $a, b, c$

Show that if $a, b$ and $c$ are integers with $c|ab$ then $c|(a,c)(b,c)$.  Now $(a, c)$ and $(b, c)$ would both divide $c$ since it's the gcd, but how would I show $c$ divides their product, and $(a,c)(b, c) \geq  c$ and not the other way around?


Reference style links validating as improperly formatted code

Here's a pickle: reference style links in markdown are fantastic. Numbered footnotes, however, can be a pain. Named references are a beautiful solution, but the editor seems to choke on them in certain contexts, throwing an error:  your post appears to contain code that is not properly formatted as code...  I've looked at a  and tested it out quite a bit and I'm pretty sure line breaking isn't the problem, named references are valid , and I can get multi-word named references to work basically every time (in this post, even). Is there a reason for named references to be seen as improperly formatted code in certain contexts? At the risk of being verbose (but for the sake of completeness), here's the source of the specific question I was trying to post when I encountered the problem: I'm trying to build a [Google Apps Script] that integrates with [Trello], the idea being to use it to push information from spreadsheets and forms into the [Trello API] and create cards on a `pending` list on a certain board.  I found this [question] on here that pointed me in the right direction, and added in OAuth based on the [GAS OAuth Documentation]. The problem is I can't post the the board. I run the script, the OAuth prompt fires, and the script completes with no errors. I can also `GET` data from the private board, so I assume the authorization is working properly.  So, what am I doing wrong that prevents my script from `POST`ing to Trello?  Here's the code I'm working with:      var trelloKey = [Trello API key];     var trelloSecret = [Trello API key secret];     var trelloList = [the id of the list we're posting to];      var oauthConfig = UrlFetchApp.addOAuthService('trello');         oauthConfig.setAccessTokenUrl('https://trello.com/1/OAuthGetAccessToken');         oauthConfig.setRequestTokenUrl('https://trello.com/1/OAuthGetRequestToken');         oauthConfig.setAuthorizationUrl('https://trello.com/1/OAuthAuthorizeToken');         oauthConfig.setConsumerKey(trelloKey);         oauthConfig.setConsumerSecret(trelloSecret);      function createTrelloCard() {        //POST [/1/cards], Required permissions: write       var payload = {'name': 'apiUploadedCard',                       'desc': 'description',                       'pos': 'top',                       'due': '',                       'idList': trelloList};        var url = 'https://api.trello.com/1/cards'       var options = {'method' : 'post',                      'payload' : payload,                      'oAuthServiceName' : 'trello',                      'oAuthUseToken' : 'always'};        UrlFetchApp.fetch(url, options);     }  [Trello]: http://trello.com [Google Apps Script]: https://developers.google.com/apps-script/ [Trello API]: https://trello.com/docs/ [other question]: http://stackoverflow.com/questions/18710641/trello-api-how-to-post-a-card-from-google-apps-script-gas [GAS OAuth Documentation]: https://developers.google.com/apps-script/guides/services/external#making_requests_to_services_with_oauth  If I'm being a complete dunce, please let me know. It seems like one of those errors where it's either a hardcore backend bug or a really stupid user mistake and I'm ready to admit to the latter.


Transiting from Heathrow (LHR) to Newark (EWR) to La Guardia (LGA) to Toronto Pearson International Airport (YYZ)

I have a valid Canadian Study Permit - Visa and will be travelling to Toronto Canada this summer via British Airways and I've booked and paid for my flight ticket, which has 2 connections from Muritala Muhammad Airport in Lagos to Heathrow Airport London and to Newark Liberty International (EWR) to LaGuardia Airport (LGA) in order to board my final flight to Toronto. My question goes thus: do I need a Transit Visa to board the US bound plane from Heathrow to Newark International and transiting from Newark Liberty International to LaGuardia Airport to board my last flights to Toronto?


What happens if a Linux distro is installed with no swap and when it’s almost out of RAM executes a new application?

What happens if a Linux, let’s say Arch Linux or Debian, is installed with no swap partition or swap file. Then, when running the OS while almost out of RAM, the user opens a new application. Considering that this new application needs more RAM memory than what’s needed, what will happen?  What part of the operating system handles RAM management operations, and can I configure it to behave differently?


I am travelling to USA via Kuwait and the layover is 18 hours.   I am Indian citizen and have valid USA Visa B1/B2 valid for the next 10 years.  Please update me I have to book a flight and need some help.


Background worker failing to attach event handler

I am adding a background worker process to my dll to report progress back to the gui. I have the following problem   I am getting the following errror :     Severity  Code    Description Project File    Line    Suppression State   Error   CS0120  An object reference is required for the non-static field, method, or property 'Program.slate_ExportReportProgress(object, SlateExportContext.ProgressArgs)' SlateExportApiTest  C:\Projects\fhsslateexport\SlateExportApiTest\Program.cs    24  Active   This is my implementation  //update the progress to the client   public EventHandler<ProgressArgs> ReportProgress;  // Eventargs to contain information to send to the subscriber public class ProgressArgs : EventArgs {     public int Percentage { get; set; }     public string Message { get; set; } }  public void TransferToSlateBackground() {     var worker = new BackgroundWorker();     worker.DoWork += DTOBackGroundWorker;     worker.ProgressChanged += worker_ProgressChanged;     worker.RunWorkerCompleted += WorkDone;     worker.RunWorkerAsync("input"); }  public void DTOBackGroundWorker(object sender, DoWorkEventArgs e) {     e.Result = e.Argument.Equals("input");     DTOCaseObject(); }  private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { }  public void WorkDone(object sender, RunWorkerCompletedEventArgs e) {     var result = (bool)e.Result; }   The code that raises the ReportProgress event is:  int step = 100 / CaseAssets.Count(); int i = 0;  // Report progress if somebody is listening (subscribed) if (ReportProgress != null) {     ReportProgress(this, new ProgressArgs { Percentage = i, Message = "Exporting to Slate   " + caseid.ToString() }); }   But it is when I am calling the code from the gui / console app i have the problem.  here i wire my event handler   _slateExport.ReportProgress += slate_ExportReportProgress;  public void slate_ExportReportProgress(object sender, ProgressArgs e) { }   But I am getting the error above  Edit 2  I don't believe this is the main problem the problem I am facing is with an event not a property or a form control


Consider this 3D plot:  \documentclass{standalone} \usepackage{pgfplots} \begin{document} \begin{tikzpicture}   \begin{axis}     \addplot3[surf,domain=-4.5:4.5]{(x^2)-(y^2)};   \end{axis} \end{tikzpicture} \end{document}     How can I alter the rendering style of the ticks so that   ticks are only drawn next to their labels, not on the opposite axis? ticks are only drawn on the background faces of the 3D box, not the on the invisible foreground faces?   Here is the resulting picture I have in mind (I erased the unwanted ticks in the bitmap):


How do I get my Realtek wireless USB adapter working? (0bda:0811)

I've tried following along with  and , and tried searching for the correct driver, but I had trouble figuring out which it was. I did not find clear information pertaining to my specific hardware.  The adapter does not show up with sudo lshw -C network.  And lsusb gives:  $ lsusb | grep -i realtek Bus 001 Device 007: ID 0bda:0811 Realtek Semiconductor Corp.   I'm running 16.04, dual booting with Windows 10, and this hardware is working in Windows.  Thanks in advance for any help.


How to cd into a directory with this name "-2" (starting with the hyphen)?

I have a directory named:  -2   I want to cd into it but the cd complains:  bash: cd: -2: invalid option   With no success, I've tried:  cd "-2" cd '-2' cd \-2   Any solution?  Edit: no file browsers like mc, etc. available on the server.


Multilabel classification versus yes/no classification for each class (with label priority)?

NOT A DUPLICATE. These questions are related, but mine is asking about a specific application of classifiers - flagging Stack Exchange posts. I want to know which of the 2 methods is most effective for THIS TYPE OF JOB. This question is different also because the true/false classifiers are run in a specific order (most priority to least priority). UNMARK AS DUPLICATE!   I want to write a program that can automatically review the Stack Overflow Triage queue. It will classify text as "Looks OK," "Requires Editing," and "Unsalvageable." If it's unsalvageable, it will then classify the text into a specific close reason.  I've come up with 2 methods to do this:   Use multilabel classification to classify the text into one of the closure categories. (No category has priority over another) Go through the close reasons individually, in a hardcoded order, and decide if it belongs in the category or not. If it belongs, it flags the question. If it doesn't, it moves to the next close reason and repeats. If it hasn't been identified by the end, the question is determined to be good-quality. (The order in which the program checks the classes is important)   I don't know which way is more effective. I thought of the 2nd way because a question that is both off-topic and offensive should be flagged just as offensive. Therefore, "offensive" has a higher priority than "off-topic."  Priority order:   Offensive? Spam? Very Low Quality? Blatantly Off-Topic? Unclear? Recommendation? Super User/Server Fault Opinionated? Too Broad? Vague Debug? No Repro/Typo? Requires Editing/Looks OK   Which of the 2 algorithms gets the job done better?


Why don't I see infinite images with parallel mirrors?

Sitting on the barbershop, watching myself in the mirror which is parallel to another mirror (so that two mirrors are parallel to each other), I was seeing an infinite number of photocopies. After a moment, I guess that it's really not infinite, I can count the number of copies. But we know from our elementary optics course, that the two parallel makes an infinite number of copies. This leads me to ask, Why it is that parallel mirrors not make infinite images?  Here I think the finite speed of light would play a role, but I think not that significant. I don't if it's due to the fact if the mirror is not that enough parallel or they are not enough flat.


Prove the inequality ${1 \over a^3 (b + c)} + {1 \over b^3 (a+c)} + {1 \over c^3 (a+b)} \ge \frac 32 $ given that $abc = 1$

Prove the inequality $${1 \over a^3 (b + c)} + {1 \over b^3 (a+c)} + {1 \over c^3 (a+b)} \ge \frac 32 $$ So, I know a proof for this, but I basically memorized it without understanding. It's $$ {(\frac 1a + \frac 1b +  \frac 1c)}^2 + {(a(b+c) + b(a+c) + c(a+b))}^-1 = {ab + bc + ac \over 2} \ge {\frac 32} $$ I don't know what inequalities were applied here or how. Another proof would also be appreciated.


Infinite extensions of "finite degree under $\mathbb{Q}$"

Consider an algebraic extension $K$ of $\mathbb{Q}$.  The degree $[K:\mathbb{Q}]$ of $K$ is defined as the dimension of the extension considered as a vector space.  Now, let $\overline{\mathbb{Q}}$ be algebraic closure of $\mathbb{Q}$.  My question is,     Can we built an arbitrary algebraic extension $F$ of $\mathbb{Q}$ such   that $[\overline{\mathbb{Q}}:F]=n$, for any $n\in \mathbb{N}$? How?


Is this sequence convergent for n in natural numbers

Is $a_n = \frac{1}{n}+\frac{1}{n+1}+...+\frac{1}{2n}$ convergent? If so find its limit.  Heres what ive tried:  $... < \frac{1}{n}+\frac{1}{n+1}+...+\frac{1}{2n} < \frac{n}{n} = 1$  What should I put on the left side of the inequality? I tried $\frac{n}{2n}$ but that tends to a half and I cant think of solving this in any other way except the squeeze rule.


How do I find de sum of this serie using the partial sums?  $$\sum_{n=1}^\infty \log\left[\frac{(n+1)^2}{n(n+2)}\right]$$  Thanks!


To evaluate the sum $\frac{1}{5}-\frac{1 \cdot 4}{5 \cdot 10}+\frac{1 \cdot 4 \cdot 7}{5 \cdot 10 \cdot 15}-\ldots$

Right now I am working through archived papers of a math aptitude quiz. For some reason I seem to be haveing a hard time with these series problems. I have managed to write the above series in a compact form but thats as far as I got.   $$\frac{1}{5}-\frac{1 \cdot 4}{5 \cdot 10}+\frac{1 \cdot 4 \cdot 7}{5 \cdot 10 \cdot 15}-\ldots = \sum\limits_{i=0}^\infty (-1)^i\frac{\prod\limits_{j=0}^i (3j+1)}{5^{i+1}(i+1)!}$$  Help please!


Should I use 'the' before the word 'banking system'?

Should I use 'the' before the word 'banking system' when I refer banking system as a whole?


Why did Jar Jar vote differently than Amidala would have?

Padmé Amidala was known to be against the creation of the Republic's Army, stating that raising an army would inevitably lead to war:     Padmé : I warn you, if you vote to create this army, war will follow. I have experienced the misery of war first-hand; I do not wish   to do it again.   But, later on, Jar Jar, acting as a Representative for Naboo moves a vote to grant the Chancellor Emergency Powers including the power to create a Grand Army of the Republic.  Since Padmé was so vocally opposed to this idea, why would Jar Jar vote differently than she would have wanted? Why didn't the opposition group Senators stop him?


Why doesn't House Baratheon/House Durrandon have a Valyrian Steel Blade?

The Stormlands and it's inhabitants seem to have a theme of being the most war-like of the Seven Kingdoms, similar to how the Westerlands theme deals with wealth and trickery, the Vale with honour etc, House Durrandon even have "Ours is the Fury" as their house words so why did they in the hundreds of years when they were independent kings acquire a Valyrian Steel blade ?   You would expect as a more martially oriented house to be even more interested in acquiring one than the Lannisters for example.   I included House Baratheon in the title because as they are in spirit and in blood the modern day successor to the Durrandons.


When rolling a pair of standard six-sided dice, what is the probability that both dice land on the same number?

I know that the formula of probability is the following:  P= FO(favorable outcomes)/PO(possible outcomes)  What I do not understand is what is the number of PO(possible outcomes) ?  If we take into consideration the order of the dice (i,e 2,1 is a different outcome than 1,2)then  there are 36 possible scenarios.  But when we are not interested in the order (in Backgammon game the order is not relevant) there will be only 21 possible scenarios.  In this particular scenario which should be the probability ? 6/36=1/6 or 6/21=2/7 ?


He  Anyone know how to get the same ids here into one row along with the other column after the comma, so group by id where there is another record from other column.     SELECT     CONCAT(p.ID, ', ', '', s.[value]) 'id, OtherColumn'    FROM [Test].[Person].[Name] s   INNER JOIN [Test].[Person].[Nameref] sr ON s.Id = sr.ID   INNER JOIN [Test2].[Test2] p ON sr.Id = p.ID    GROUP BY p.ID, s.value  1, 4GL 1, Web 1, CCS   Needs to be:  1 , 4GL, Web, CCS   Thanks


Why did he say "You are right about him" to Batman?

In Batman v Superman: Dawn of Justice, In a dream sequence a red suit character appears through a portal and it appeared like Flash to me. So why did he (maybe Flash) tell Batman that he is right about him and helps in making Batman's decision against Superman? So why did he want them to fight?


A question on Infinite Series/Sequences.

I am having trouble finding an answer to a question i have. I am pretty sure its a relatively simple question with a simple answer but cannot find it.   What i want to know is if you have two infinite sequences(maybe series not sure which is the correct term) if they are both countably infinite can one be larger than the other if one is a subset of the other. a simple example would be.  since all the odd numbers are a subset of all the natural numbers would the natural numbers contain more elements than the odd numbers since the odd numbers are a subset of the naturals?  I know both these sets are infinite but wouldnt the natural numbers be of a higher order than just the odd numbers. common sense tells me there are exactly twice as many natural numbers than odd numbers. but common sense doesn't work as you approach infinity.  Thanks in Advance


Environment variables. Where are they saved in?

If I do not edit the .bashrc or other config files, the environment variables that I've setted are gone when I logout, or turn off the terminal.   What I'm curious is, where are those 'temporary' env vars saved in?   As I guess, they might be in the memory. That makes sense because they will disappear when the terminal is turned off(equals the terminal I was using is gone from the memory). Am I correct?


So I tried blocking some websites for obvious reasons but I can still keep going to these sites even when I 'supposedly' blocked them.  I've edited the /etc/hosts file so it looks like this (example being Facebook)  0.0.0.0       https://www.facebook.com 0.0.0.0       facebook.com 0.0.0.0       www.facebook.com   Yet I can still access Facebook. What am I doing wrong?     EDIT: Only Chrome seems to block out the website, though I can still   access it trough Safari and Firefox.   I'm running OS X Yosemite


How to tidy and expand my partitions after Windows removal from dual boot

I recently removed the Windows part of my dual boot drive. I now just have Ubuntu 16.04 LTS.  I now want to maximize the amount of disk space my remaining Ubuntu partition has and to tidy things up.  I am looking at Gparted:    I see that:   Ubuntu seems to be installed on sda5 The swap-space is on sda6 and is 15.88 GB. Is this too large? I have RECOVERY on sda7. Is this related to Windows? Do I still need this. I have lots of free space after removing Windows   I want to remove anythings that I don't need and want to maximize the space for my Ubuntu partition.   I'm aware that I need to make any changes while using a bootable USB drive version of Ubuntu.   Any help in the steps to do this would be gratefully received.


How can I find what package provides a missing man page on CentOS?

At the bottom of man pcregrep, there is a message:  SEE ALSO         pcrepattern(3), pcresyntax(3), pcretest(1).   However, when I try to view man pcresyntax I get:  $ man pcresyntax No manual entry for pcresyntax $ man 3 pcresyntax No entry for pcresyntax in section 3 of the manual $ man -k pcre pcre-config          (1)  - program to return PCRE configuration pcregrep             (1)  - a grep with Perl-compatible regular expressions pcre_table           (5)  - format of Postfix PCRE tables pcretest             (1)  - a program for testing Perl-compatible regular expressions   I tried yum info pcresyntax and even yum search pcresyntax and got nothing.  At the suggestion of some comments posted below, I tried yum provides pcresyntax and yum whatprovides pcresyntax and got no results.  (This box is running CentOS 6.6.)  What package includes the man page pcresyntax?  More importantly, how can I find out what package includes a man page that I am missing?  (This is primarily for missing man pages that are mentioned in other man pages, rather than missing man pages for an installed command.  In other words, man pages that are not obviously associated with a given command.)    NOTE: I work with Linux professionally and I am interested in broadly applicable answers, as well as answers specific to any of the major package managers.  pcresyntax is just a specific example of a missing man page, not the end-all of my question.  Currently at work I primarily use yum, mostly on RHEL/CentOS 6, and I asked the title question rather than "where can I find the pcresyntax man page?" because I would like to know as much as possible about how to find and install missing man pages, for professional use both now (RHEL/CentOS) and in the future (Ubuntu/Debian, OpenSUSE, ...?)  Since asking this question I also found the  which answered all my immediate questions about PCRE.  ;)


Makehuman pose broken between 2.69 and 2.7x

I just upgraded from Blender 2.69 to 2.71. I loaded my previous save file and found, to my dismay, that my pose no longer displayed properly. I'm using Makehuman version 1.0.0. It appears that FK still functions as expected, but IK does not. IK hand and foot targets do not affect arm and leg placement. The root bone appeared to work.  Any ideas how I can (preferably) revive my save files with the new version? Alternatively, is there a way I can export the pose from 2.69, save in the neutral position, then re-import the pose in 2.71? I don't see any export options for poses in 2.69.


How to make div take up 100vh height minus the height of the header?

I am trying to set up a hero section where the div takes up 100vh minus the height of the header. I originally set the css height property to calc(100vh - 310px). 310px is the height of the header on my monitor. However I am trying to find a responsive solution, where the height of the header is dynamic and can change based on screen size. Not sure how to go about doing this. I assume it is not possible using css and am fine using javascript/jquery to solve this.

  .heroSection {    height: calc(100vh - 310px) }


A few questions regarding the Horcruxes.   Had Voldemort actually succeeded in using a Horcrux, would he come back the same age (biologically and/or aesthetically) he was when he made the Horcrux, or the age he would biologically be if he had never died (half died)? If Harry was a Horcrux, then in the graveyard, when Wormtail added Harry's blood to the potion to bring Voldemort back, didn't that technically use up the Horcrux inside of Harry? So in Deathly Hallows when Voldemort kills Harry, shouldn't Harry have actually died rather than just have the Horcrux inside him destroyed, seeing as it was technically used in the Goblet of Fire?


Let $W$ be a standard, one-dimensional Brownian motion. Let $T\in(0,+\infty)$. Then $$\lim_{\beta\to+\infty}\sup_{0\le t\le T}\left|e^{-\beta t}\int_0^te^{\beta s}\mathrm{d}W_s\right|=0\quad\text{a.s.}$$ Could someone give some hints or proofs?


This is how I think Linux signals work:  Each process have a default signal handler for each signal, some signals's default signal handler terminates the process, while other signals's default signal handler simply ignores the signal, etc.  The following table shows all the actions that a default signal handler can take (this table is from this ):     Term   Default action is to terminate the process.      Ign    Default action is to ignore the signal.      Core   Default action is to terminate the process and dump core (see          core(5)).      Stop   Default action is to stop the process.      Cont   Default action is to continue the process if it is currently          stopped.   You can override the default signal handler with your own signal handler by using  (which I think is deprecated) or .  Am I correct so far?  Now my question is: Are there some signals that you cannot override their default signal handler?


Angular 6 input file, how to display preview of pdf file

I have simple app where I have input where I can upload pdf file and  <input (change)="upload($event)"        multiple        type="file"/>  <object [data]="file" type="application/pdf">     <embed [src]="file" type="application/pdf" /> </object>   in upload function:  upload(event) { this.file = event.target.files[0]; }   How can I display preview of that file?


Git 1.7.9.5 Upgrade to current release of GIT 2.x on ubuntu 12.04

I'm currently on ubuntu 12.04 and since this is an older version of ubuntu i have git 1.7.9.5 installed and i'm not sure how i can upgrade this to git 2.x.   what do i type to install git 2.x (sudo apt-get install git)? when installing git 2.x, does it overwrite git 1.7? if not how do you choose which one to use? how do i find out where git 1.7 is installed on my system?


The instructions I'm looking at (on how to roll over a 401(k) to an IRA) say that I should open a new traditional IRA account.  I have one that I've used for a rollover in the past (it was created to accommodate the rollover).  Is there any reason I can't use this same one for this rollover, or do I really need to open a new traditional IRA for this?


why the Vitali set has size $2^{\aleph_0}$?

why the Vitali set has size $2^{\aleph_0}$ and therefore there is a bijection between $\mathbb R$ and the Vitali set? thanks


Should I be able to see the first few lines of a deleted post from my flag summary section?

I don't have enough rep to view deleted posts yet. So should I be able to see the first few lines of a post via the tooltip?: (ie. rolling over the titile of a post gives you a tooltip with the first few lines of the post, just like hovering over a question on the main question page)    Yes, it's spam, I know, but there are more legit reasons for flagging - should a low-rep user be able to see a bit of this content??


Can Windows 7 be repaired to run with new motherboard?

I have HP computer and it came with Windows Vista. It also had an option to upgrade to Windows 7 via upgrade disc. I have upgraded to Windows 7 via the special upgrade disc (It is special because it will only allow to install Windows 7 if Vista is already installed.  My motherboard recently died. I just replaced it and Windows 7 will not start up. It reboots and sometimes gives a blue screen of death. Very similar problem as described in this post: . Windows will not boot into normal or safe mode. Start up repair from system repair disc does not fix the problem. However, "" post on superuser describes that it should be possible to run Windows 7 on a new motherboard.  Is it hopeless to find a way to repair Windows 7 and I need to do a clean install? Is there a difference for repair options between OEM and retail versions of Windows 7? I remember doing this type of repair just fine in Windows XP days, so why am I unable to do so with Windows 7 - is it Microsoft or HP's fault? Should I stop buying HP computers or should I switch to Ubuntu?


Difficulty providing a saliva sample for DNA testing

I find it difficult for medical reasons to generate the spit needed to do a genealogy DNA test. What are my options?


Deleting List Entries while iterating through a List

I have the following code  final List<ItemDto> itemDtos = result.getResults(); List<String> deleteItemIds = new ArrayList<String>();  // remove items which have been deleted on the server for(ItemDto itemDto : itemDtos) {   if (itemDto.getIsRemoved()) {     deleteItemIds.add(itemDto.getId());     itemDtos.remove(itemDto);  //  TODO not sure if this works here   } }   I iterate over the itemDtos and remove an ItemDto at the last operation in the for loop. I think that this works if I do not need something like itemDtos.indexOf(o)inside the loop.   Is the code I did correctly working?  Edit: Here is a second variant:   List<ItemDto> itemDtos = result.getResults(); List<ItemDto> tmpList = itemDtos; List<String> deleteItemIds = new ArrayList<String>();  // remove items which have been deleted on the server for(ItemDto itemDto : tmpList) {   if (itemDto.getIsRemoved()) {     deleteItemIds.add(itemDto.getId());     itemDtos.remove(itemDto);  //  TODO not sure if this works here   } }   Is the second variant better?


How to catch only the row you enter in a text area before pressing ENTER key in JS/JQuery?

I am working on an example and want I want to do now is to catch the value of some rows in a text area after pressing ENTER. I have detected the ENTER key press using this JQuery function:  $('#output').keypress(function(event){      var keycode = (event.keyCode ? event.keyCode : event.which);     if(keycode == '13'){         var read_lines = $('#output').val().split("\n");         alert(read_lines);       }  });   and I try to catch the values in the #output text area using this:  var read_lines = $('#output').val().split("\n");     alert(read_lines);   but it catch all the text in the text area not only the one I insert before pressing Enter key.  Can you please help me?  Here is my .


I have a php script on a server to send files to recipents: they get a unique link and then they can download large files. Sometimes there is a problem with the transfer and the file is corrupted or never finishes. I am wondering if there is a better way to send large files  Code:  $f = fopen(DOWNLOAD_DIR.$database[$_REQUEST['fid']]['filePath'], 'r'); while(!feof($f)){     print fgets($f, 1024); } fclose($f);   I have seen functions such as  http_send_file http_send_data   But I am not sure if they will work.  What is the best way to solve this problem?  Regards erwing


Resolution Problem Using Ubuntu on a Dell Monitor

I am having trouble running Ubuntu on a custom made desktop (some specs below). The problem is that at a certain point my monitor shuts off and gives me the message:   The current input timing is not supported by the monitor, Please change your input timing to be 1920x1200@60Hz   Initially I was having this problem during installation, so when the first purple screen would come up I hit the down arrow and set nomodeset and added "vga=0x14d" to the end of the command. This allowed me to continue without getting the above error on my monitor. Once installation was complete I edited /etc/default/grub to include the line:  GRUB_GFXMODE=1920x1200   Then I entered:  sudo update-grub   And restarted the computer. Now when I get to the Grub screen, everything is fine but after the that I again run into the input timing error. I have tried various permutations and combinations in the edit screen but I can't seem to set the resolution properly to actually see Ubuntu once it has started up.  Relevant specifications: Ubuntu version: 16.04 Motherboard: Asus X99-E GPU: Nvidia GTX 1080 Monitor: Dell U2412M  EDIT: The motherboard does not have an integrated graphics card. EDIT2: I tried following the answer for , however setting nouveau.modeset=0 at the end of the line that begins with "linux" does not work, I still get the input timing error above and if I cannot boot into Ubuntu then I am unable to install drivers.


How to create converting constructor in javascript?

I am asking for good practices showing how to create a converting constructor in Javascript with the correct chain of prototypes.  It should: - get the existing object as a parameter - return a new class type object that contains all the properties of the old class - add new properties  - change some of the properties  I want to avoid manually rewrite all properties.  If someone has a reference to examples of good practices creating other types of constructors and their inheritance, this can be helpful.  Right now working (but ugly) solution is here:  //Function from ( https://stackoverflow.com/questions/728360/how-do-i-correctly-clone-a-javascript-object ) function deepClone(obj) {         var copy;          // Handle the 3 simple types, and null or undefined         if (null == obj || "object" != typeof obj) return obj;          // Handle Array         if (obj instanceof Array) {             copy = [];             for (var i = 0, len = obj.length; i < len; i++) {                 copy[i] = deepClone(obj[i]);             }             return copy;         }          // Handle Object         if (obj instanceof Object) {             copy = {};             for (var attr in obj) {                 if (obj.hasOwnProperty(attr)) copy[attr] = deepClone(obj[attr]);             }             return copy;         }          throw new Error("Unable to copy obj! Its type isn't supported."); }    function A() {     this.param1 = {'a': 1};     this.param2 = 'b'; }  A.prototype.getParam1 = function() {     return this.param1; }  function B(objectToCopyFrom) {      //Code to copy all properties from the objectToCopyFrom and inherite prototype.     Object.assign(this, deepClone(objectToCopyFrom));      this.param1.a += 2;     this.param3 = 'c'; }  B.prototype = Object.create(A.prototype);  B.prototype.getParam3 = function() {     return this.param3; }  var a = new A(); a.param1 = {'a': 2};  var b = new B(a);  console.log(b.param3); //Should print: "c" console.log(JSON.stringify( b.getParam1() )); //Should print: "{'a': 4}"  a.param1.a = 8;  console.log(JSON.stringify( b.getParam1() )); //Still should: "{'a': 4}"      Please help me do it in a better, cleaner way without ES6 if it is possible.


Story about colonists of one of jupiters moons, with frail sibling that died during crisis

I'm pretty sure that this was an entire book, written before the 90's, the protagonist was a teenage male, and his family was emigrating to one of the moons of Jupiter. When they got there they found that the younger sibling couldn't take the lack of pressure, so had to live in a sealed room with higher pressure. They were farmers, and he had this plow which broke up the stony surface. There was a crisis, and the sealed room broke and the child inside died. I think the rest of the family went back or left, but the boy stayed to continue the colonization.


How to make the Camera rotate more than one time?

How can I circle the camera around more than one time?    Hope you can help me.


One person with whom I've emailed before said to "drop me [them] a line". I always thought the intention of this phrase is to call the person, specifically by phone (via telephone line). It seems this person means to email them. I do think it's possible they mean to call them. Is it a widely accepted use of this phrase to mean "contact me" in general? Is this usage common among certain groups of people? Am I wrong in associating this with phones in particular?


I used the following code to convert a bytes array to a string:  byte[] saltBytes;  // ... filling the array with some values  for (int i = 0; i < saltBytes.Length; i++) {     builder.Append(saltBytes[i].ToString("x2")); }  string salt = builder.ToString();    Now,  I would like to revert this process and convert my string to a bytes array. I was reading this question: .  The answer mentions:     If you already have a byte array then you will need to know what type   of encoding was used to make it into that byte array.   I'm not sure about the encoding used in the snippet I posted. Does this have to do with the ToString("x2") part?


Smallest subfield containing $F$ and $\alpha$

Let $F$ be a field and let $K$ be an extension of $F$. Show that if $\alpha\in K$ is algebraic over $F$, $F[\alpha]=\{p(\alpha)\mid p(x)\in F[x]\}$ is the smallest subfield of $K$ containing $F$ and $\alpha$.


Pagination go to first page if i'm on last post

I have a custom post type and used get_next_post() and get_previous_post() to create a simple pagination. However i need to create a pagination loop (if that is the correct term). If i'm on the first post i need to browse back to the last post and if i'm on the last post i need to browse to the first post. Is there a simple way to do this that i haven't seen but Google, this site and the codex has not been very helpfull :/  The current code i have is. I've tried to use wp_list_pages and other functions but with little luck.  $next_post = get_next_post(); $prev_post = get_previous_post(); $nav = array(     "next_post" => array(         "url"       => get_permalink($next_post->ID),         "id"        => $next_post->ID,         "titill"    => get_field("vinstri_titill", $next_post->ID)." - ".get_field("vinstri_undirtitill", $next_post->ID)     ),     "prev_post" => array(         "url"       => get_permalink($prev_post->ID),         "id"        => $prev_post->ID,         "titill"    => get_field("vinstri_titill", $prev_post->ID)." - ".get_field("vinstri_undirtitill", $prev_post->ID)     ), );


How can you view your durability on minecraft?

How can you view the durability? When I do F3+H it doesn't work. I have version 1.7.2, and I'm using mods, but not any durability mods. I'm using a Lenovo laptop and an Acer laptop running Windows 8.


If a spell is countered, do on cast effects still get triggered?

If I cast a spell that has an "on cast" effect, does the effect still trigger even if the spell is countered? For example, if I play  and it gets countered by a counter spell, do I still get to exile 2 target permanents?


How do I set up Outlook to send a auto reply during a certain hour of the day every day?

I would like to protect myself from unreasonable demands during my work day.  One of those is telling people that I will not respond to any emails before 3pm.  I'd like to set up a rule in outlook that replies to all emails before 3pm with a specific message. I'd like this to be done every day, no matter the date.  How do I set this up?  I've scoured Google best I can so far, and I think, based on a Exchange forum, that a script might be needed for this.  But what I found so far was only server side scripts. I need something on my own machine.  references:


Find $n$ for which $\frac{n(n+1)}{2}$ is perfect square

Prove there is an infinite amount of natural numbers for which $\displaystyle \frac{n(n+1)}{2}$ is a perfect square.


I've just installed Ubuntu 16.04 LTS on a laptop. This laptop had previously w7. It's a dv6 pavilion, with dedicated radeon graphics card and integrated Intel graphics.  As far as I know, this laptop is 6 years old, and the only problem it had, was that the dedicated graphics don't work anymore. Basically if you install the drivers of this dedicated graphics, it gets blue screens and doesn't work. So since I found it out, I used it with Intel graphics, and no problem.  I put Ubuntu on it, and I just updated files. As soon as I tried to restart, it got completely frozen. Turning off and on the laptop again, every time I try to reboot it, it does the same thing.  SSD 250GB, completely formatted, just with Ubuntu 16.04 LTS on it.  Do you think the OS is trying to communicate with the dedicated graphics and gets frozen? How can I fix this?  Thanks.


RegEx search for X if true then return emty string else return the whole string

I'm struggling to find the correct RegEx for this problem:  I want to search a string for a value. If true, the result should be an emty string, otherwise the whole string.  Example  "We have apples, oranges, and peas"   Check for "apples" -> "  Check for "tomato" -> "We have apples, oranges, and peas"  I have to solve it using a standard RegEx statement. Since it is the only way I can modify the original string in the application.  Basically what I want to do is:  s="We have apples, oranges, and peas"  w="tomato"  IF instr(s,w)>0 then result="" else result=s   The problem is that the only way I can modify the string is by a regex syntax  I believe I have solved it by myself. Have no clue why it works :)   (?(?=.*apples)|.*)|.*   returns nothing as I want   (?(?=.*banana)|.*)|.*   returns We have apples, oranges, and peas  The following regex also works   ^((?!apples).)*$


Is AES-256 a post-quantum secure cipher or not?

We know  speedup brute-force attacks two times faster in block ciphers (e.g brute-forcing 128-bit keys take $2^{64}$ operations, not $2^{128}$). That explains why we are using 256-bit keys to encrypt top secrets. But  on AES shows brute-forcing AES-256 take $2^{100}$ operations. Does this attack work with Grover's search to make AES cipher quantum unresistant?


I have control files which inside will have a count of the expected records in the csv file. Each csv file has an accompany ctl file. My question is what is the best way to match the files with it's counterpart? I think there must be a better way than nested for loops. This is Bash Shellscript.  example content of ctl file:  101   Directory where files are:  /home/user/example   Example file names:  project_example_1998-01-01.ctl project_example_1998-01-01.csv project_example_1998-02-09.ctl project_example_1998-02-09.csv project_example_1999-08-09.ctl project_example_1999-08-09.csv project_example_2000-02-09.ctl project_example_2000-02-09.csv


What would have happened if Thor reached ground before breaking the glass?

In The Avengers, Loki says to Thor, “The humans think us immortal; let’s put that to the test”, and drops the glass chamber.  Loki clearly knows that Thor is an immortal and he is doing this to scatter the Avengers, so what would have happened if the glass chamber reached the ground before Thor could break it??   Would Thor have been killed or injured?


While exploring color codes in the Matplotlib Library of Python, I came across this piece of code: x,y,c=zip(*np.random.rand(30,3))  I looked up the working of the built in function zip() in Python, but I do not seem to undertstand the role of * before the numpy random statement. Thanks in advance.


Simple Fermat's Little Theorem Corollary

I'm probably missing something super simple, but I just can't figure this out. For integers $a,p$ such that $gcd(a,p)=1$ then Fermat's Little Theorem states $$a^{p-1}=1 \mod{p}$$ My textbook then says if $a$ is a primitive root and $x\equiv y \mod{p-1}$ then $a^x=a^y\mod p$. Can someone help me understand this proof?


I have been given a PC operating Windowsxp. Browsing with Maxathon as Internet explorer and Google chrome not supported. I desire to run Ubuntu to replace my OS and have downloaded the file Ubuntu. I cannot open this file. Basic question but cannot find solution through google or in help article. Cannot open ISO file. Help!


There is a document on the web that I want to store in my Google Drive. The only way I know to do this is saving the document on my computer and then upload it again to my Google Drive.  Is there a more straightforward way to do this?


Is it possible to remove an empty white page due to inserting a too large picture?

From searching here, I have understood than when inserting a picture too large for the available space, even on an empty page, the picture will be put on the next page. However, leaving a page empty seems… not very usefull, as the next page will also be too small. Is it possible to prevent the insertion of an empty page?   Here is a code example:  \documentclass[a5paper,11pt]{book} \usepackage[french]{babel} \usepackage[T1]{fontenc} \usepackage{graphicx} \usepackage[top=0cm,bottom=0cm,inner=0cm,outer=0cm]{geometry}  \begin{document} {\includegraphics[width=1.1\textwidth]{C:/OSM/CarnetRando/Cartes/1_Thann_Nord.png}} \end{document}


I have six figures. I want to create a single figure with 6 subfigures each with its own caption and, if possible, a global caption.  I have tried and subflots, subfigure, tables and none of that worked.  With subfigure I can't figure out how to tell it to create three rows of figures instead of the compiler resolving it to a six figures in one column. If I add two figures I get them side by side. I add a third and/or a fourth I get one column.  With tables, I can do what I want however I can't figure out how to add the caption to each subfigure.  With subfloat I get this error:  ! Undefined control sequence.  \sf@counterlist   When using it like in this question:   I know I should be copying code but it is way too large since all pictures are tickzpictures. I was wondering if anywone could provide a minimal working example.


Let $\{a_n\}$ be a sequence of real numbers. Define $\sigma_n = 1/n(a_1 + \dots + a_n)$. Suppose that $\lim a_n = a \in \mathbb{R}$. Show that $\lim \sigma_n = a$.  Here is my work so far...  Fix $\epsilon > 0$. We are given that for $N \in \mathbb{N}$ we have that $|a_n - a| < \epsilon/\alpha$ whenever $n \geq N$, and $\alpha$ will be choosen later. We must find $N \in \mathbb{\widehat{N}}$ so large such that $|\sigma_n - a| < \epsilon$ whenever $n \geq N$. Note that  $$|\sigma_n - a| = |1/n(a_1 + \dots + a_n) - a|...$$  Then I got stuck trying to work out the details. Should I try showing that the $\sigma_n$ is a Cauchy sequence, and somehow use the convergence of the $a_n's$? Thanks for your help.


I have created a dirctory named test. Within this directory I have created a file named test.txt. When I execute the program below, the output for list method on cmd does not show the list of files in test directory.  Following is my code:  import java.io.*;  public class f1{     public static void main(String args[]){     try{         File f = new File("test");                 System.out.println(f.exists());                 System.out.println(f.isDirectory());                 System.out.println(f.isFile());                 System.out.println(f.list());     }     catch(Exception e){      } }   }  Following is the output:   true  true  false  [Ljava.io.File;@15db9742


Derivation of linear discriminant analysis (LDA) decision boundary

I've been reading the Introduction to Statistical Learning and Elements of Statistical Learning by the Stanford professors Hastie and Robert Tibshirani and I've been trying to derive the discriminating function knowing the posterior for LDA, assuming common covariance matrix, p=1 and Gaussian distribution. . If our assumption for normal Gaussian distribution of the likelihood holds we obtain the Bayes Classifier.   In the second picture it's mentioned that we take the log of the posterior but detailed steps of the derivation are not provided and I'm not sure  how to derive it.


Use "ac" for showing the acronym but not the entire definition when called the first time

Apologise for the bad title, I didn't succeed in summarizing what I mean.  I use the acronym package.  I set up a list of acronyms like  \begin{acronym}[AWGN]  \acro{UK}{United Kingdom}  \acro{USA}{United States of America} \end{acronym}   that I recall using, for example:  \ac{UK}   When I use one particular acronym for the first time, it also shows its definition. For example, this text  London is the capital of \ac{UK}.   is shown as     London is the capital of United Kingdom (UK).   But I only want     London is the capital of UK.   How can I do that?


How to take a screenshot of my PC's BIOS?

How can I take a screenshot of my PC's BIOS?


Looking for guidance for the following question: Let $a_n$ a sequence, such that $\left| {{a_{n + 1}} - {a_n}} \right| < \frac{1}{n}$ and $\{5,-5\}$ are partial limits of $a_n$. Show that $0$ is also a partial limit.    I don't see how both conditions can live together. Obviously, the difference between the terms of $a_n$ are getting closer and closer, so how can this sequence have $\{5,-5\}$ as partial limits?     I'd be glad for clarification and guidance :)


Tourist visa to the US but work for foreign country?

My friend is staying with me in the United States for 2 months. He is visiting me from Japan. He wants to work for Japan while being a tourist here to help me pay the bills. He found an online job, which is located in Japan. Can he do this online job while physically present here in the United States, for Japan, get money deposited into his account from the company physically present in Japan, and then use that money here inside the United States without breaking any employment laws?


How would I generate random numbers ranging from -9 to 9?

double random1 = Math.random() * 9 + -9;         double random2 = Math.random() * -9 + 9;   I need randomly generated numbers ranging from -9 to 9 using Math.random. When I use this code I have here it only prints the first number as a negative number.I've ran this multiple times and still the first number is always negative while the second is positive. How can I fix this to be more random? Thanks


In C, how can i get input (integer) without using ENTER?

I cant use scanf() because to receive integer input you need to press ENTER (when you are running the program).


`sudo echo "bla" >> /etc/sysctl.conf` permission denied

Disclaimer: I'm pretty novice at sysadmin stuff.  I'm trying to set up port forwarding in an AWS EC2 instance, this has to be done in the command-line because I don't want to go in and edit anything, it has to be automatic (it's part of a build process).   sudo echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf      Permission denied   The weird thing is I've been (successfully) using sudo for pretty much every command that required su privileges. If I do sudo su before the command (trying it out by hand in an ssh session), then it works.  Reasons behind this? Possible solutions that don't involve sudo su or manual edits?


Do F-1 students need a visa to visit Paris and Amsterdam during layovers?

I am an Indian citizen with F-1 status travelling from the U.S. to India. I am going to have a layover of 12 hours in Paris while on my way to India and another layover of 6 hours in Amsterdam while returning from India. Do I need any visas for sightseeing Paris and Amsterdam during the respective layovers?


When i start blender it makes transparent all objects and i see only just yellow outline

This happens only in EEVEE cycles works fine. I reinstalled Blender 2.8 and 2.9 but problem still appearing.


I have read somewhere that when an object is approaching the speed of light then its relative mass is increasing by the formula $m=\frac{m_0}{\sqrt{1-(\frac{u}{c})^2}}$. Is this true? If yes then why this happens? Does an object really increase its mass when it has bigger velocity or it has to do with the mommentum? I am confused.If here on earth we measure 1 kg and then accelerate it at $u=c/2$ then its mass will be bigger?