Effects of formatting a laptop

Question: If I format my laptop will software packages such as Microsoft Office (Microsoft Word, Power Point, etc.) be deleted? If so can they be recovered after deletion?
Comment: Your real question seems to be how you can remove all the personal information from the laptop before giving it to a friend.  A factory recovery/restore sounds the most sensible, though some programs would likely still need to be installed.
Answer: In the simplest terms, if you format your laptop's hard drive you will erase all the contents of that drive and your drive will be empty.  All your programs and data will be gone.  Will they be recoverable?  Again, in the simplest terms, no, they cant be recovered.
Now to get more advanced.  Technically speaking, a standard format of a drive does not erase any of your data and programs.  It deletes the information that where operating system says it stored that data is on the drive.  All of your programs and data are still sitting right where they were before you formatted them.  So, technically, it is possible to recover everything, but this is not a trivial task.
There is a lot more to formatting and data recovery that can be discussed, but I believe that would be outside the scope of your question.  And speaking of your question, you left out a lot of information from your question, perhaps you should explain why you want to format your drive.
Comment: I'm formatting the drive so I can give a friend the laptop but I don't want a situation whereby my friend has to get a new OS or basic software packages. I basically want to remove all my saved documents, pictures etc and restore all the factory settings so he can use it with ease
Comment: This is definitely getting beyond the scope of the original question.  If you want to securely erase the drive so your data cant be recovered, use a drive erase utility like DBAN.  However, this would mean reinstalling the OS and applications.  If you have the original installation media, you can easily reinstall the OS and applications.  Of course, you would have the media and license keys to him as well to stay legal...
Comment: @Keltari  DBAN? That is EXTREME.. This is a friend that cannot format a laptop himself, do you really think he's going to be doing data recovery on a formatted drive seeing the old info?  Many people who have fixed computers for 10 years+ haven't ever done that! I doubt his friend is interested in doing data recovery on a formatted drive either
Comment: @barlop it would prevent recovery of old data.  and giving an explanation on scrubbing just the "essentials" is out of the questions scope.
Comment: @Phillip please ask the question more clear. You don't really want to know what happens during a format but how to *wipe personal data only*. This is a completely other topic.
Comment: @ju.kreber let the author tell us what he wants...
Comment: @Ramhound well to look at the first comment here, this sounds different to me than the question
Answer: In simple words:

Formatting a partition just changes some information on the partition table and marks the space as available, deleting it just marks it as free space, but neither actually zeroes it. See this other answer for info on deleting files.
Since the information isn't completely deleted, you can recover it again using recovery tools like undelete.
If you start creating new files on the newly formatted partition, you start using some sectors that previously contained information, and if those sectors contained information you wanted to restore, they're unrecoverable.

But for most cases: once a partition is formatted or deleted, the information is lost.
Comment: This is technically completely correct. But i think you should mention that for a normal user, the files do get deleted and it is certainly not that easy to recover them.
Comment: Sure it is; I could lost 30 program all free that are not very technical at all
Comment: @Ramhound Sorry, I don't understand your comment.
Comment: Well sorry I thought the question was more about restoring the data after a format and not to completely wipe it all. Maybe i missed the questioners intention...
Comment: @arielnmz I said I could lost 30 free programs all that anyone even the most basic computer user could use to recover files.  I was basically saying your answer is fine and saying its hard to recover files is a fallacy ( in other words not true )
Comment: Ok now I get it, and I agree completely with you.
Answer:
If I format my laptop will software packages such as Microsoft Office (Microsoft Word, Power Point, etc.) be deleted?

Yes.

If so can they be recovered after deletion?

No.
Unless you have an old-style hard drive that doesn't erase things you delete. But even then, it's tough to recover the data stored in the registry. It's hard enough that I'd advise you to buy a new copy of Office rather than attempt recovery.
I apologize that this answer conflicts with the 4 existing answers, but many technical users don't yet understand how SSDs reclaim sectors using TRIM, GC, and when formatted. Undelete is a thing of the past.
Comment: So if I want to avoid getting a new copy of Office formatting should be avoided
Comment: Yes;Isn't that what you want to do?
Comment: If you have a retail copy of Office, or some other way of installing Office, you don't need to buy a new copy.
Answer: In very technical terms, No, formatting doesn't delete everything.
But practically, unless he'd doing some advanced data recovery, if he looks on the drive for any files, and the drive is formatted, he won't see any files there. And if it's a 150GB drive, the drive comes up as having 150GB free.
If you want to really wipe the drive so data is unrecoverable even by advanced data recovery techniques, then I suppose writing zeros on the drive will do it. But it's most probably not necessary to do that.
When you format it, then all the programs and files are gone (data recovery aside).
If you want to remove your personal files, and have everything as default, then one option is contact your laptop manufacturer. Sometimes they provide a CD/DVD that has a process that puts the laptop back to how it was when you bought it.  If it didn't have Office originally, it won't have it when you do that.  And if it had junk software on it originally (like McAffee - a bloated anti virus program), then it will have that on there again. Sometimes they have an option at startup to do it.
You could remove personal files manually. You know what your personal files are.
And note that -technically- deleting files doesn't delete them, it just deletes references to them.. So somebody that knows data recovery techniques could 'undelete' them. But I don't think you or your friend are likely to be doing data recovery but there are programs to delete files securely. This program http://eraser.heidi.ie/   but that's really if you want to be paranoid. Many people just delete files and consider them deleted. If you had sensitive info and your friend was very technical and a thief and cunning then you might want to use that program.. or better, not give him your laptop.
Comment: Thanks, the information given was more than enough and I doubt my friend would try to recover info but I'll the program into consideration.
Answer: Formatting your hard drive means erasing every single piece of date written on it. So jep, your software (and your data) will be deleted. For this purpose, there are many backup & restore programs out there (some are free!). Some have the ability to restore only several parts of a backed up archive, your Word and Powerpoint for example.
Also, if you plan to format your hard drive, be sure you have something (a DVD, or a recovery partition) to set up a new Windows installation as this also gets deleted.
[Edit: Well yeah if you have a real close look on it, no data really gets erased, nobody just knows it is there. And it is possible to recover (as long as you don't write new data on it), yet for a normal user this is not useful]

Effects of formatting a laptop


When will a string be garbage collected in java

Question: In Java, when an object has got no live reference, it is eligible for garbage collection. Now in case of a string, this is not the case because the string will go into the string pool and JVM will keep the object alive for re-use.
So that means a string once created will 'never' be garbage collected?
Answer:
Now in case of a string, this is not the case because string will go into the string pool and JVM will keep the object alive for reuse. So that means a string once created will 'never' be garbage collected?

First, it is only string literals and string-valued constant expressions (see notes) that get automatically interned / added to the string pool.  String objects that are created by an application at runtime are not interned ... unless your application explicitly calls String.intern().
Second, in fact the rules for garbage collecting objects in the string pool are the same as for other String objects: indeed all objects.  They will be garbage collected if the GC finds them to be unreachable.
In practice, the String objects that correspond to string literals typically do not become candidates for garbage collection.  This is because there is an implicit reference to the String object in the code of every method that uses the literal.  This means that the String is reachable for as long as the method could be executed.
However, this is not always the case.  If a string literal was defined in a class that was dynamically loaded (e.g. using Class.forName(...)), then it is possible to arrange that the class is unloaded.  If that happens, then the String object corresponding to the literal may then be unreachable, and may ultimately be GC'ed.
See also: When and how are classes garbage collected in Java?

Notes:

A string literal (JLS 3.10.5) is a string that appears in Java source code; e.g.
  "abc"            // string literal
  new String(...)  // not a string literal

A string produced by evaluation of (compile-time) constant expression (JLS 15.28) may also be interned.
   "abc" + 123      // this is a constant expression

Strictly speaking, not all String literals are interned:

If a String literal only appears in the source code as a sub-expression of a constant expression, then the literal may not appear in the ".class" file in any form.  Such a literal won't be interned because it won't exist at runtime.

In Java 9+, string concatenations involving literals and values that are not compile time constants may be handled differently.  Now, at the option of the bytecode compiler, a string concatenation like the following:
 int x = 42;   // not a compile time constant
 String s = "prefix " + x + " suffix";

may result in a string constant like the following being interned:
 "prefix \1 suffix"

At runtime, the above string constant is used as the "recipe" for generating a dynamic concatenation method. The original string literals (i.e. "prefix " and " suffix") would not turn into interned string objects.
Kudos to @Holger for pointing this out.  More details are in JEP 280 and the javadoc for StringConcatFactory.

Prior to Java 7, the string pool was in PermGen.  For some versions of Java, garbage collection of PermGen was not enabled by default if you selected the CMS collector.  But CMS was never the default collector AND there was a flag to enable PermGen collection by CMS.  (And nobody should be developing code for Java 6 and earlier anymore.)
Answer: You are correct; strings in the intern pool will never be GC'd.
However, most strings on not interned.
String literals are interned, and strings passed to String.intern() are interned, but all other strings are not interned and can be GC'd normally.
Comment: "strings in the intern pool will never be GC'd." - That's not correct for a modern Hotspot JVM.  It is more complicated ...
Comment: @Jaskey - the String that you just created with `new` will not be interned.  The String object that represents the string literal *will* be interned.
Comment: @RamanSahasi - It is not obsolete.  It was never completely correct in the first place.
Comment: Keep in mind that "literal strings" occupy storage because they're effectively a part of your program.  They have to be there or your program will be missing something.
Comment: Please note: This answer is obsolete and doesn't apply to modern JVMs.
Comment: But wouldn't that consume a lot of memory? Especially for large programs that use a lot of strings?
Comment: @Eng.Fouad: No, unless they're interned.
Comment: "will HelloWorld" still be interned when we use "new String("HelloWolrd");"?
Answer: String objects which are in the string pool will not be garbage collected. Other String objects will be garbage collected if you don't have reference to it in your program execution.
You may ask which string objects goes to string pool.Objects in the string pool are either:

Compile time literals (e.g.String s1 = "123";)
Interned String objects in the runtime (e.g. String s2 = new String("test").intern();)

Both s1 and s2 reference a string object in the string pool.
Any objects which are created at run time and not interned will act as a normal object and reside in heap memory. These objects can be garbage collected.
An example of this would be: String s3 = s1 + s2;
Here, s3 references a string object which resides in heap memory alongside other objects (not in the String pool).
Comment: *"String objects which are in the string pool will not be garbage collected."* - This is incorrect.  The string pool >>is<< garbage collected, and has been since (I think) JDK 1.1.  (In JDK 1.6 and earlier, if you used CMS you needed to set a JVM option to enable PermGen GC.  But CMS was never the default GC.)
Answer: Before Java 7 the string pool resided in Permanent Generation space. So string literals were never garbage collected (which also led to out of memory issues many a times)
After Java 7, string pool is placed in heap space, which is garbage collected by the JVM. It also reduces the chances of getting Out of memory issues in JVM.
Comment: There are a number of misstatements in this answer.  The reason that string **literals** were (and are) unlikely to be garbage collected is that the classes that declared them normally remain reachable for the application's entire lifetime.  This is true whether or not the string pool is in permgen or the regular heap.  (The permgen >was< garbage collected.)
Comment: And of course ... the permgen was removed in Java 8.  Meaning that the only versions of Java that *did* have a permgen were EOL'd a long time ago.


Nextjs Sitemap not fetch by Google search console

Question: I created a small web application with Next.js and it works fine. Now I need to index that on google. It has dynamic pages too. So I created a dynamic sitemap using Sitemap npm module. But when I tried to add it to the search console it displays an error saying that the sitemap couldn't read. After that, I validated it using this website and it says my sitemap has no issues. What should I do to get rid of this error? I have added a photo of my error below.
Thanks
Comment: Is there something that is blocking Googlebot from accessing the sitemap.xml? Did you find anything in server logs (corresponding to the user-agent that contains Googlebot)?
Comment: I didn't find such a thing as that. But I have hosted this on vercel with their free subdomain. So is that be the problem?
Comment: Maybe. You may have to check with Vercel support on this.
Comment: An XML sitemap is not going to get your site indexed.   It is a common misconception, see my blog: [Myth: An XML sitemap is needed for SEO; it helps rankings](https://blog.ostermiller.org/xml-sitemap-rankings/)  You need to create links to your dynamic pages if you want to get them indexed.  It doesn't matter whether Google is processing the sitemap or not.
Answer: A way to test and find the source of the problem is to generate another sitemap and introduce it to Google Search Console. If that new one submitted successfully, you can conclude the first one really had some sort of issues.
I suggest to use Yoast SEO plugin to generate a new one because of it's easily usage. Hope to be helpful.
Comment: I tried adding sitemaps in a couple of different ways. But none of them are worked. I think the Yoast SEO plugin is for WordPress. Since this is a NEXT.JS project are there any possibilities to use that on NEXT.JS?
Comment: @PasinduPrabhashitha You're right. It's for WP. I suggest using this link to repair it.
https://cheatcode.co/tutorials/how-to-generate-a-dynamic-sitemap-with-next-js


Integration of Heaviside (step) function

Question: Ok, I do not have much experiencing using (or even integrating) Heaviside-step functions, so I am looking for a little help. The integral in question is,
\begin{equation}
6m^2\int_0^\infty d\mu \frac{1}{\mu^3}\sqrt{1 - \frac{4m^2}{\mu^2}}\theta(\mu-2m)
\end{equation}
where $\theta$ is the step-function. Any help direct help or hints is of course appreciated. (The reason it is actually in here in the first place is that without it the integral is divergent). I was thinking about performing integration by parts to turn the step-function into a delta-function $\delta(\mu-2m)$ but then the integral in the end would just give 0 when I know this integral is equal to $1/2$ (I am just trying to show that).
Answer: Notice that
$$
\theta(\mu-2m)=
\begin{cases}
0\,\,\text{if}\,\,\mu<2m, \\
1\,\,\text{if}\,\,\mu>2m.
\end{cases}
$$
Therefore,
$$
\int_0^\infty d\mu \frac{1}{\mu^3}\sqrt{1 - \frac{4m^2}{\mu^2}}\theta(\mu-2m)=
\int_{2m}^\infty d\mu \frac{1}{\mu^3}\sqrt{1 - \frac{4m^2}{\mu^2}}.
$$
Comment: Oh.... Ok, that helps. Then the integration is just $\frac{1}{12m^2}\left(1-\frac{4m^2}{\mu^2}\right)^{3/2}$ which at the bounds becomes just $\frac{1}{12m^2}$ with the factor of $6m^2$ becomes simply $\frac{1}{2}$. Thank you!


Do different ellipsoids have different location of centre?

Question: I wanted to understand how latitude and longitude of a location change by changing the reference ellipsoid. If the location of centre in 2 different ellipsoids is same, and they differ only in the length of minor/major axis, then I don't see how latitude /longitude of a place will differ if any of those 2 ellipsoid is taken as reference.
Answer: If two ellipsoids share the same origin and axes (both use Greenwich and the same North pole), but have different axes lengths, only the geodetic latitude will change between the two. This is true because geodetic latitude is defined as a line perpendicular to the ellipsoid surface.
However, you shouldn't normally think in terms of the ellipsoids, but of the geographic/geodetic coordinate reference system (GeoCRS) AKA geodetic datum. A GeoCRS contains a geodetic datum which is in turn defined partially by an ellipsoid.
Current, modern (GNSS-based) GeoCRS will try to have the ellipsoid centered at the earth's center of mass. NAD83 and its realizations/re-adjustments is not quite there as it turns out and that's part of the reason why it's drifting farther from WGS84 and ITRFxx realizations over time. (it's also due to tectonic plate motion among other reasons)
Older GeoCRS / datums like ED50, NAD27, Pulkovo 1942, etc. were all defined locally. I've always explained this as someone chose an origin point, set the direction of North and then fit an ellipsoid to the set of control points being used. That is, the ellipsoid surface is matched to the earth's surface in a local area, not worldwide. That often means that the ellipsoid's origin is not at the earth's center of mass.
One way to model the differences of an older, local datum and a modern one which doesn't have a surface "origin point". Is to figure out the translation values in XYZ (3D Cartesian) between the two ellipsoid's origins, plus sometimes rotation values because the XYZ axes aren't quite the same, and a scale value.
For modern frames, these values were generally be small, sub-meter at worse, because the two frames are trying to be coincident. For modern/older combinations, the translation values can be hundreds of meters different, a few seconds off in rotation, and several parts-per-million different in scale.
This is for non-Earth data, but check out slide 86 on this SEDRIS presentation.
Disclosure: Esri employee and member of subcommittee that maintains the EPSG registry.
Answer: The combination of an origin, latitude and longitude defines a vector in three dimensions. This then intersects with the surface of an ellipsoid (or geoid) to define a location on it's surface.
Assume you keep the latitude and longitude constant. Imagine the vector as a line from the origin out into space. Then as you change the ratio of the ellipsoid's minor and major axis' the point at which the vector intersects the ellipsoid's surface will change.
If that doesn't work, approach it from the opposite direction. Imagine a location 'A' as a dot on the surface of an ellipsoid that isn't in line with one of it's axis. Now visualise the line connecting this location to the origin, and it's angles to the axis' (i.e. lat and long). If the ellipsoid changes then your dot 'A' will moved in absolute (x,y,z) space. Still with me? This means the angles defining the line connecting the origin to 'A' have also changed.
Looking at these pictures and reading this will hopefully help.
Comment: Suppose, I've got two reference ellipsoids(different major to minor axes ratio). But both have same origin. Will the latitude and longitude of a place differ in any of them? I don't yet see how they will differ since the origin is same and it is the angle we have to see in both the cases i.e. latitude and longitude.
Comment: I can see that the elevation will change in both cases. But I'm not able to understand about latitude and longitude.


Regression or mutual information when we have mix of discrete and continuous variables

Question: I am trying to identify relevant features for a problem. The features are discrete and continuous in [0,1]. The target variable is [0,1]. I have tried linear regression by standardizing(subtract mean and divide by standard deviation) all the features.
For example,
10,4,0.5,0.3 and the target is 0.6.
I have two doubts:
i) do I need to standardize the data for linear regression (I am getting p-value of 0 for most of the features)
ii) Should I use beta regression, mixture model or mutual information regression. Do these methods need standardization.
Answer: The best method for your problem is Logistic Regression, also called Logit Regression.  This is a variation of OLS Regression that specifically caters to a binomial dependent variable (0,1).  Logistic Regression is very flexbible.  While the Y variable has to be (0, 1), the Xs variables can be pretty much anything you want: binomial (0, 1), discretionary, continuous.
When using Logistic Regression, I don't think you will get much benefit from standardizing variables.  That's because it just does not make that much sense when using binomial variables (0, 1).
If you care to standardize variables in your model, I would only standardize the continuous ones, and not the binomial ones.
Comment: Thanks for the reply. I also want to test which variable or feature is important. In linear regression, I can look at regression co-efficient and p-values. Can we do similar analysis for logistic regression?
Comment: Yes, exactly.  Logistic Regression is really just another OLS Regression regressing the log of the odd transformation of a variable.  The log of the odd is called an ogit.  And, that's why it is also called Logit Regression.  You will get regression coefficients, t-stats, p-values as regression output just like for OLS regression.


Tab key does not indent in Powerpoint 2010

Question: I am having the same problem as this question here: Tab key in Microsoft Word does not increase indent in bullet lists. But the answer provided doesn't seem to work in Powerpoint 2010 anymore. This is the option list that I found, but I can't find the option needed:
Answer: PowerPoint behaves the way you'd expect it to re bullets and tabs when you're entering text into a body text placeholder, but not when you're entering text into a regular text shape or other shape.
If it's not a text placeholder, use the Increase List Level and Decrease List Level buttons on the Paragraph group of the Home tab instead of using the tab key.
Comment: Also wont work.
Answer: I found that when I use themes, sometimes I experience this and other strange behavior with bulleted lists. What I do when I encounter this problem is just delete the text box and then insert a new one. It works every time.
Comment: I'm not sure what you are saying? What is "this"? what is the strange behavior, what text box are you deleting, what themes are you speaking of?


View a powerpoint created on a Mac with TIFF images on Windows

Question: I have a few powerpoint lectures that contain TIFF files that cannot be displayed on Windows. The images are blank except for the words "Quicktime and a TIFF (Uncompressed) decompressor are needed to see this picture". It is my understanding that this is as a result of the powerpoint being created on a Mac. Since I have no access to a Mac, is there any way to convert it? Any programs that run on Windows which would allow me to view the slides with the images would also work.
Comment: What happens if you install quicktime on windows. Do you have this possibility (i.e. or do you have to show the presentation on a borrowed computer).
Comment: I strongly suppose that. You can choose the format when you saves the presentation. What happens if you store the presentation in a different format?
Answer: Installing QT on Windows won't help unless things have changed in the latest Windows versions.
This problem occurs when you copy/paste pictures into Mac PowerPoint.  The fix:  Don't Do That.  Use PowerPoint's Insert Picture, From File command to bring the pictures in.
Unfortunately, you have to do this on the Mac in the first place.  You can't fix it on the PC, so you'll have to go back to the presentation's author for a fix.


Is it possible to contribute a native speaker for editing the paper and add him/her as authors? Is there anyone?

Question: I'm working on SIMDization and Optimization. I usually do some great jobs. But writing a good article needs a good knowledge of writing skill. I've implemented many programs. I can write and organize the paper. But editing the article take a lot of time for me, because of some silly grammatical mistakes. I just thought it might be possible to contribute someone who knows English well and add him/her name as the second author. Is It a good Idea? If yes how can I find someone? Preferred from Toronto Ontario.
Comment: So ... you want someone you don't know and is not at all familiar with your work to proofread and edit your paper for free ... respectively for appearing as an author? First, this person won't fit the definition of authorship. Second, if it's not one of your close colleagues where you already implemented a give and take, you should/have to pay for the proofreading.
Comment: I meant to find someone who is interested in researching especially my field as a coworker. Not only edit the paper for free and add the name.
Answer: This may vary in some ways by field, but it is generally not considered sufficient for an individual to be included as an author on a paper if that person's sole contribution to the paper is proofreading and editing. Readers, reviewers, and journal editors expect that each author has made a significant technical contribution to the material presented in the paper. If there isn't a monetary payment involved, credit to someone for editing a paper usually takes the form of written thanks.
Answer: Since you find yourself unable to spend money on editing services by publishers (in chemistry I know only about them by ACS or Wiley) or local proof readers (like this example in Toronto lists 33 names/contacts) maybe there are programmers you know (because their work inspired you, or/and will be cited by you) you may reach out.
Or --- relating in analogy to R, Python, Emacs --- contacting a local usergroup (like this about C++) of a programming language / software you use is an alternative; in contrast to an English student at the university they already know the technical terms of your field, and you could pay them not only by money.


Difference between a mixture model and ensembling

Question: Can someone explain to me the difference between a mixture model and a model ensemble? It seems both of them incorporate multiple models.
Answer: The term "mixture model" typically means a model of a dataset that is thought to contain several subpopulations. The subpopulations may have the same general distributional form but with differences in parameter values such as means or variances. The task is then to find a combination of such subpopulations that best describe the data. This page shows an example of mixture modeling in practice. See the tag for finite mixture models for references.
The term "model ensemble" is used in a situation where you are trying to find the relationship between outcome variables (a continuous variable, known class membership, occurrence/timing of events) and a set of predictor variables. The ensemble combines predictions from several models into a final prediction. Sometimes, as in most of the methods mentioned on this page, the various models are of the same general form (e.g., decision trees) and only provide weak predictions individually, but when combined they provide superior performance. In other types of ensembles even the types of individual models can be different.
As one example of the difference in application, you could use a mixture model to try to identify clusters of related cases within a population. You could use a model ensemble if you already knew the cluster membership and wanted to see how other variables were related to cluster membership.
As often happens, of course, there can be confusing terminology. For example the "mixture of experts" talked about on this page is really a model ensemble, not a mixture model as the term is generally used.
Answer: They are very different, with the most obvious difference of several being in the order of operations such that in ensemble modeling there are two or more processed models, the results of which are then combined, and, for mixture models there is one model with two or more combined terms that is then processed.
Ensemble modeling is the process of running two or more related but different analytical models and then synthesizing the results into a single score or spread in order to improve the accuracy of predictive analytics and data mining applications.
For mixture models, using the simplest example of having only two models for random variables, there is only one model consisting of the arithmetic sum of two scaled models for random variables (Do not confuse the sum of two models for random variables with the pairwise outcome sum of two random variables). For example for two normal distributions, a mixture model is
$$p\;\mathcal{N}(\mu_1,\sigma_1^2|x)+(1-p)\;\mathcal{N}(\mu_2,\sigma_2^2|x)=\\ \frac{p}{\sqrt{2 \pi } \sigma_1 }e^{-\dfrac{(x-\mu_1 )^2}{2 {\sigma_1} ^2}}+\frac{1-p}{\sqrt{2 \pi } \sigma_2 }e^{-\dfrac{(x-\mu_2 )^2}{2 {\sigma_2} ^2}}$$.
Note posted due to comments: 1) This sum is not a joint list sum, there are no paired discrete values in a list, and $x$ is not random, it is simple independent variable defined on $(-\infty,\infty)$. 2) The correct notation for the convolution of two normal distribution models is written as
$$\mathcal{N}(\mu_1,\sigma_1^2|u)\ast\mathcal{N}(\mu_1,\sigma_1^2|u)(x)=\\
\frac{e^{-\dfrac{(\mu_1+\mu_2-x)^2}{2 \left(\sigma_1^2+\sigma_2^2\right)}}}{\sqrt{2 \pi } \sigma_1 \sigma_2 \sqrt{\dfrac{1}{\sigma_1^2}+\dfrac{1}{\sigma_2^2}}}$$
Note the dummy variable $u$,  and the presence of  the convolution operator $\ast$ rather than a '+' sign. Some people use $\star$ with or without the required dummy variable. In any case, it is not a sum, and convolutions are only sums for joint  random variable outcomes undergoing addition, one outcome pair at a time, such that unlike a mixture RV which can have $n\neq m$ and $n+m$ outcomes, a finite sum convolution of two RV's has $2n$ entries and $n$ sums. To turn a continuous process convolution written as an integral into a summation with uncountable many additions is possible in the Riemann sense, but that is not the sense here. 3) A normal distribution does not have to be used as a model for a random variable at all. It might, for example, be used as a model for bacterial density versus linear displacement from the center of bacterial colony in a Petri dish, and bacteria per square mm are just not probabilities.
There appears to be considerable confusion between what density functions are and what random variables are. Note 1) a density function is not always a probability density function and whatever notation is used must allow for both contingencies. 2) Density functions of the continuous type are often used as models for physical situations and in different circumstances are often used as models for random variables. There are many who, at the present time, refer to density functions as if they were all random variables. It is most of the time misplaced terminology in the sense that more frequently a pdf of a random variable, is a model for that random variable, and is not itself random in any sense.
The take home on this, as told to me by my Easter bunny, is that "If a random variable were an egg, a pdf would be a Fabergé egg."
Comment: (-1) In the 2nd paragraph you've confused summing random variables (to give a new random variable) with summing their weighted density functions (to give a new density function, that of the mixture distribution), though the explanation in parentheses is all right. The mathematical expression you've provided is for the density function, given that $\mathcal{N}$ is the normal density function. (Also, I don't know what you mean by "*unpaired* random variables" - "*independent* random variables" perhaps?)
Comment: Sorry, it's the third paragraph where you refer to the "sum of two unpaired random variables"
Comment: Well, to take up your example, the sum of two random variables having normal distributions is another random variable having a normal distribution, not a mixture of two normal distributions.
Comment: Provided they're independent (which I should've mentioned), they do. See [Sum of normally distributed random variables](https://en.wikipedia.org/wiki/Sum_of_normally_distributed_random_variables) & note the 2nd paragraph: "This is not to be confused with the sum of normal distributions which forms a mixture distribution".
Comment: @Scortchi The sum of two scaled density function models for random variables is not random, it is just a function. I have corrected my wording to be more exact and explained the difference.
Comment: @Scortchi The concept of independence of random variables is a *non sequitur* in a context that does not imply random variables. What is relevant is whether data is of coordinate pairs,  which  invokes convolution, or the data entries are unpaired, which does not invoke convolution. In other words, even when a density function points to a probability and is a "pdf", it is still not an RV, just an $f(x)$. I have earned your (-1) based on your confusion, not mine.


If $X$ is a genus $g\geq 2$ curve over a number field $K$, then is there a bound on $X_L(L)$ for $L/K$ that depends only on $X$ and $[L:K]$?

Question: If $X$ is a genus $g\geq 2$ curve over a number field $K$, then $X(K)$ is finite by Falting's Theorem. My question is how does $X_L(L)$ behave for finite field extensions $L/K$? In particular, is there a bound on $X_L(L)$ for $L/K$ that depends only on $X$ and $[L:K]$?
Answer: Assuming the conjecture that varieties of general type cannot have a Zariski dense set of points over a number field (which is a consequence of the more precise Vojta conjectures, for example), Patricia Pacelli [1] proved the following, which is much stronger than what you're asking, since the constant only depends on the genus of $X$:
Theorem Fix $d\ge1$ and $g\ge2$. There is a constant $C=C(g,d)$ such that for all number fields $L/\mathbb Q$ of degree at most $d$ and all smooth projective curves $X/L$ of genus at most $g$, one has $\#X(L)\le C(g,d)$.
Pacelli's result is a generalization of an earlier result by Caparaso, Harris, and Mazur [2] that wasn't quite as uniform, but that really set in motion the use of this conjecture to prove uniformity result of this sort.
But if you want unconditional results, I don't think there's anything known in general, although one might(?) be able to get something like
$$
\#X(L) \le C(X,[L:K])^{1+\text{rank Jac}_X(L)}.
$$
[1] Patricia L. Pacelli, MR 1448017 Uniform boundedness for rational points, Duke Math. J. 88 (1997), no. 1, 77--102.
[2] Lucia Caporaso, Joe Harris, and Barry Mazur, MR 1325796 Uniformity of rational points, J. Amer. Math. Soc. 10 (1997), no. 1, 1--35.
Comment: Thanks!

I am indeed interested in unconditional results. Just to be clear, the rank of the L-points of the Jacobian of X is not known to be bounded by $[L:K]$? Is it flat out false?
Comment: Sorry, I meant bounded by a constant that depends only on $[L:K]$ and $X$.
Comment: @AndrewNC The rank is bounded by a constant depending on $X$ and  $[L:K]$ and the size of the class group of $L$ (or even on, say, $p$ and the $p$-rank of the class group of $L$ for any fixed prime $p$), but that class rank is not known to be bounded by $[L:K]$. There are some current conjectures about uniform boundedness of ranks of abelian varieties, but they are still just conjectures, and somewhat controversial at that.


Can I communicate two separate articles that use identical experimental test procedures but use different materials?

Question: I am working on composite material modification with the combinations X + A + P and X + A + Q (where, X, A, P, Q are different materials). For both works, I used the same testing methodologies (experimental program). Now, I have enough data for two separate research articles on each of the combinations X + A + P and X + A + Q. Is it acceptable if I submit two papers that use the same experimental methodology but different material combinations? Note that providing all of the results for the two combinations in one paper would make it overly long.
Comment: The paper would be overly long because you feel that way, or overly long relative to various journal guidelines?
Comment: Continuing  Jon Custer's point, its also worth considering if the length can be mitigated. If its from the discussion it may be tricky, but if its just the sheer amount of figures and tables, some of these could moved to the Supporting Information if they are just another way of conveying the same info or are interesting, but not the main result of the paper.
Comment: It really depends on the true meaning of your schematic resume above. I think we can't judge. It even depends on the journal you have in mind.
Comment: @Tyberius Thank you for your input! The materials P and Q in the combinations X + A + P and X + A + Q come from distinct sources and behave differently. Also, it is not possible to accommodate the whole discussion in a single article.
Answer: It is possible to write two publications in such a case, no problem. This is a common strategy. Make sure to cite the other work where appropriate.
However, in a paper you have to address a specific research question. It could well be the case that especially the second paper is only an incremental step forward because it does not include too many fundamentally new results. So while I see no ethical issue here, you still could ask yourself if you might be able to write one very strong paper with your data. If that is true, of course, depends very much on your actual results.
Comment: Thank you for your reply! Incorporating all of the results into a single paper would make it excessively lengthy.
Answer: Is it interesting to compare the two compositions? If so, combining the results in a single paper may make for a better, stronger article, as Snijderfrey suggested. If not, separate papers that dive into the specifics of the materials may be preferable.
You say that "providing all of the results for the two combinations in one paper would make it overly long". That's probably true, but invites the question: do you really need to provide all the results? Information dumps of the "here's everything we did" variety rarely make for the best papers. In contrast, if you have a clear story and select results and design figures accordingly, it can make for a more interesting and insightful article. Often less is more. Other results can maybe be included in supplemental material, or left out entirely. Note: I'm not saying this is a route you need to take (you know your results, we don't), just noting that "providing all of the results" shouldn't be the main goal.


Not being able to differentiate between two related but exclusive words?

Question: Is there a term to describe someone that doesn't seem able to differentiate between two words such as "racial" or "racist"? I mean beyond simply overlooking it. Like, you could try to explain the difference but then they just get mad at you. I was thinking stubborn and ignorant, but I feel like there's a more accurate term.
Comment: Usually in cases like this, the explainer is being overly pedantic about meaning without regard to actual usage and probably is ignorant (naively or otherwise) of the ways in which similar or sound-alike words are used as proxies for other words, terms, and concepts.
Answer: I think it is semantic confusion:

Misperceiving or misremembering a word as one that has a similar meaning, as when lamp is perceived or recalled as light.

And it can result in malapropism:

A malapropism (also called a Dogberryism) is the use of an incorrect word in place of a word with a similar sound, resulting in a nonsensical, often humorous utterance.

In general, the person is wrong-headed:

stubborn in adherence to wrong opinion or principles

or obstinate:

Stubbornly refusing to change one's opinion or chosen course of action, despite attempts to persuade one to do so
Answer: Obtuse.


Difference between "cariciar" and "acariciar"

Question: Both words mean "to caress" or "to fondle" according to the dictionaries. Is it really so? Are the exactly the same thing? If not, in what way does adding that "a" change the meaning? My question also pertains to several similar Spanish verbs that have a variant with the "a" prefix.
Comment: Something wrong with the question to warrant a downvote?
Answer: Some Spanish verbs are formed by adding the prefix a- and a verbal ending to nouns or adjectives. The a- prefix derived from the Latin prepositions ab ("agent") and ad ("source").
No precise rules on when to use the prefix, but usually is used when the verb formed means "to do something for..." or "the result of acting with..."
For example:
cabo = "end" ------> acabar = "finish, get to the end"
licor = "alcoholic drink" = ----> alicorar = "get drunk"

But I insist it is not a general rule, in most cases the word is historically formed and the prefix has lost meaning.
More examples:
plazo - aplazar
compañía - acompañar
tormenta - atormentar
provecho - aprovechar
pareja - aparejar
manso - amansar
largo - alargar
seguro - asegurar
cierto - acertar
crédito - acreditar
grato - agradar
firme - afirmar
consejo - aconsejar
breve - abreviar
premura - apremiar

In all these cases is wrong to omit the prefix (plazar, compañar, tormentar...)
The consciousness of etymology is lost in words like apagar, admirar, acostar, abrazar and adorar.
A similar situation occurs with the prefix en- (gancho - enganchar).
Comment: Is used in Colombia, sorry for choosing a rare example
Comment: Sounds like adding liquor to some recipe.
Comment: I never heard of _alicorar_ before. Where is it used? This is a really good answer to the question. You have my +1.
Answer: I don't thin that cariciar exits as a verb. You have the name caricia and the verb acariciar.
I couldn't find cariciar in the DRAE or RAE's Twiter and only this reference for cariciar online. I'm unsure up to which point the Wiktionary could be trusted more than the RAE. Maybe we have cariciar due to regional differences; Maybe is just misspelled somewhere. It seems that cariciar is actually a verb in Portuguese. Maybe somebody made a mistake while editing the Wiktionary?
Acariciar:

Hacer caricias. Tocar, rozar suavemente
Tratar a alguien con amor y ternura

Caricia:

Demostración cariñosa que consiste en rozar suavemente con la mano el cuerpo de una persona, de un animal

Regarding the second part of your question, in Spanish we have for example Rascar:

Refregar o frotar fuertemente la piel con algo agudo o áspero, y por lo regular con las uñas.
Arañar

I have heard people saying "arrascar" for this action although RAE doesn't contemplate it. I don't think that you can just add that "a" or take it for these verbs. Maybe there is an exception, but as a rule of thumb, I would avoid "arrascar", "cariciar", etc. Problably this is some sort of misunderstanding on the spoken language when you have an "a" in from of the verb.

Voy a acariciar al perro.

sounding like it was "Voy a cariciar al perro", and thinking that there is actually a "cariciar" verb.


How to track the state of a window toggle with python?

Question: With bpy I can call the following function:
bpy.ops.wm.window_fullscreen_toggle()

But how can I track the state of the toggle so that I avoid unnecessary calls to the bpy.ops.wm.window_fullscreen_toggle() function?
Answer: You can use the code
size = bpy.context.window.y
if size == 0:
     # it's fullscreen
else:
     # it's not fullscreen

I don't know if that's the proper way to do it, but it works for me
Comment: Will depend on screen setup.  My desktop has only a title bar across the top with a height of 64.  In full screen window y reports as -64 and in max (but not full) as 64.  It's been my experience that blenders `window.y` is dodgy on ubuntu. On toggling out of full screen it sometimes reports as 250 instead.  Found this out trying to overlay a decoration free window over a particular area type. (Text editor).
Answer: Third party window manager.
This may have changed  AFAIK there is no property exposed akin to Window.is_full_screen in blender.  Have resorted to using a third party window manager.
Get Monitor Resolution in Python
Example run on old monitor where 1200 x 1024 is full  screen resolution.
Can get blenders context  window height and width via
>>> C.window.height
1024

or loop over all windows in C.window_manager.windows
I'm on ubuntu and have the lightweight ewmh window manager module available.  The Gtk gi is another I often use for managing windows (focusing, moving workspace, making thumbnails etc)
Running from blender the current window is the active window.
>>> from ewmh import EWMH
>>> wm = EWMH()
>>> win = wm.getActiveWindow()
>>> win.get_wm_class()
('Blender', 'Blender')

Check its geometry
>>> win.get_geometry()
<<class 'Xlib.protocol.request.GetGeometry'> serial = 15, data = {'depth': 24, 'sequence_number': 15, 'root': <<class 'Xlib.display.Window'> 0x0000028e>, 'x': 0, 'y': 0, 'width': 1280, 'height': 1024, 'border_width': 0}, error = None>

Or query its states
>>> wm.getWmState(win, True)
['_NET_WM_STATE_FULLSCREEN', '_NET_WM_STATE_FOCUSED']

Ok looks like in full screen, run the op
>>> bpy.ops.wm.window_fullscreen_toggle()
{'FINISHED'}

>>> wm.getWmState(win, True)
['_NET_WM_STATE_MAXIMIZED_HORZ', '_NET_WM_STATE_MAXIMIZED_VERT', '_NET_WM_STATE_FOCUSED']

Probably worth mentioning, since I am using a window manager can do away with using the operator.
>>> wm.setWmState(
setWmState(self, win, action, state, state2=0)
Set/unset one or two state(s) for the given window (property
_NET_WM_STATE).
:param win: the window object
:param action: 0 to remove, 1 to add or 2 to toggle state(s)
:param state: a state
:type state: int or str (see :attr:`NET_WM_STATES`)
:param state2: a state or 0
:type state2: int or str (see :attr:`NET_WM_STATES`)

So to set full screen using ewmh
>>> wm.setWmState(win, 1, '_NET_WM_STATE_FULLSCREEN')
>>> wm.display.flush()

Comment: Thanks for the help. Too bad the blender doesn't have a built-in property
Answer: For ubuntu users:
import bpy
import subprocess

monitor_width,monitor_height = subprocess.Popen('xrandr | grep "\*" | cut -d" " -f4',shell=True, stdout=subprocess.PIPE).communicate()[0].split(b'x')

if(int(monitor_width)==bpy.context.window.width and int(monitor_height)==bpy.context.window.height):
    print("fullscreen")
else:
    print("not fullscreen")

reference


Mining generates block and the generation of block is rewarded with 25 bit-coins? So from where bit- coin is mined?

Question: I read that Mining of bit coins generate blocks and each block is rewarded with certain bit coins. So, from where bit coins are generated?
Answer: The new bitcoins are generated as a special transaction called a Coinbase transaction, which is the very first transaction in a block. That transaction has special inputs that don't spend previous transactions, so the bitcoins are completely new. The miners create this transaction when they create a block to be mined, paying the block reward to themselves. Thus if they are the successful miners of the block, the transaction pays them and they receive the block reward.
Note that the block reward is currently 12.5 BTC per block not 25, as of the reward halving on 2016-07-09.


Is there a term that covers advantages and disadvantages?

Question: Is there a term that refers to both advantages and disadvantages?  I'm trying to find a succinct name for a section of a report that summarises advantages and disadvantages of a particular product.
Comment: "factors" or "factors for consideration"?
Answer: You might consider consequences or effects or even results.
Answer: "Relative merits". Merits means the advantages, but the phrase "relative merits" is common and suggests a weighing up that would include disadvantages.
Comment: Wouldn't that imply a section comparing, say, the relative merits of two products rather than the good and bad points or a single product?
Comment: Yes, for me too, relative merits means comparing two products, not comparing how good or bad a merit is.
Comment: You're either comparing 2 or more products, or comparing it with the possibility of just not buying it and keeping the money, or comparing 2 or more products **and** the possibility of forgoing them all.


Serverless Framework dynamobd iamRoleStatements modify -> AccessDeniedException

Question: I've inherited an API that uses ddb. Unfortunately, everything is being done on one production table. I am in the process of completing a development setup, so we don't have to experiment on the production table. As it turns out, the new data is much cleaner and our client wants to use it instead. I figured, I could simply update the Resource block of our ddb config to point to the new ddb table resource arn but that's when I ran into trouble.
Part of the config looks like this:
...
iamRoleStatements:
  - Effect: Allow
    Action:
      - dynamodb:DescribeTable
      - dynamodb:Query
      - dynamodb:Scan
      - dynamodb:GetItem
      - dynamodb:PutItem
      - dynamodb:UpdateItem
      - dynamodb:DeleteItem
    Resource:
      - "arn:aws:dynamodb:us-east-1:*:table/${self:provider.environment.PROD_TABLE}"

At first, I simply updated the Resource block to the value below and deployed
 - "arn:aws:dynamodb:us-east-1:*:table/${self:provider.environment.DEV_TABLE}"

After the deploy I received this (redacted) error in CloudWatch:
AccessDeniedException: User: arn:aws:sts::<redacted>:assumed-role/... is not authorized to perform: dynamodb:DescribeTable on resource: arn:aws:dynamodb:us-east-1<redacted>/PROD_TABLE

Note, the arn:aws:dynamodb resource (above) is referencing the old table
A re-deploy does not update the resource for the newly created assumed (lambda) role. I am not sure how to make this happen without a "remove" and "deploy."
Forgoing an exact solution is there an easier way to switch over to a different ddb without causing any major disruption to our users?
Answer: Based in what I can see in the log

AccessDeniedException: User: arn:aws:sts:::assumed-role/... is not authorized to perform: dynamodb:DescribeTable on resource: arn:aws:dynamodb:us-east-1/PROD_TABLE

The configuration has worked as the user now does not have permissions to describeTable over the old table (PROD_TABLE).
Probably somewhere in the code you are still trying to work with the old table instead of the new one.
If you still need this you can give the role permissions for both tables:
iamRoleStatements:
   - Effect: Allow
     Action:
         - dynamodb:DescribeTable
         - dynamodb:Query
         - dynamodb:Scan
         - dynamodb:GetItem
         - dynamodb:PutItem
         - dynamodb:UpdateItem
         - dynamodb:DeleteItem
     Resource:
         - "arn:aws:dynamodb:us-east-1:*:table/${self:provider.environment.PROD_TABLE}"
         - "arn:aws:dynamodb:us-east-1:*:table/${self:provider.environment.ENV_TABLE}"


Looking for a PGN reader and writer for Windows 10

Question: I'm looking for a PGN reader and writer for Windows 10.  I want to be able to modify and write if I want to enter new lines, all while keeping the format in PGN. I've downloaded ChessX, and it would be perfect except that I can't figure out how to make the board bigger. Alternatively, any other program recommendations would be appreciated.
Comment: winboard? (6 characters to go)
Answer: The board size in ChessX can be easily changed. Close the program windows that you don't need and simply click and drag the borders of the board to increase its size to your liking. The left button of the mouse has to be kept pressed while changing the board size as in most programs. The board can be made almost as large as the size of the monitor. Font size, pieces, etc. can also be easily customized. Newer engines can be added to ChessX.
There are also older versions, e.g., ChessX 1.3.2. This older version is also free and available on the Internet, and I prefer it to newer versions, as it seems to have less clutter in the menus and in terms of windows. Still, you'd probably want to customize the board size, looks and various windows anyway.
Other programs for editing PGNs are less convenient and sometimes even buggy. Even Fritz/ChessBase, in my opinion, is inferior for editing PGN files. Therefore, I advise getting the hang of ChessX for working with PGN files rather than using other chess programs for this purpose. That said, Fritz/ChessBase is a far more advanced program with tons of options and customization and it is irreplaceable in my opinion, especially for pro players. Of course, it also allows editing PGN files but I find it far less convenient than ChessX for that purpose. Please note that Fritz/ChessBase is not free.
Answer: To save space, move all the docks to the right.
Then resize the board by grabbing the handle between board and docking widgets and resize the board (see the cursor changing to something like two vertical lines with a two headed arrow). The image below is a sneak preview to ChessX 1.58, but it works the same for all ChessX versions.


Does anyone have any good tips for starting to use emacs?

Question: I have heard good things about emacs and have dabbled in a bit of vim/neovim. I was wondering if anyone has any good tips for starting to use emacs! I am using emacs 27.1 for Windows 10.
Comment: The question is too broad and invites opinion-based answers. This site is about specific Q&A, in particular specific, focused how-to questions. You might want to post such a broad opinion-oriented question on a discussion site such as Reddit.
Comment: @Drew: You may have about thirty answers written by different people indicating their approach to configuring or using Emacs. Therefore, these are not opinions but methods.
Comment: We have had debates about ["big list" questions](https://emacs.meta.stackexchange.com/questions/305/should-we-have-a-big-list-tag-similar-to-tex-se) before.  I do not think we should do big list questions, as they do not fit with SE's format and mission, which is aimed at discrete questions rather than open-ended ones.  I cannot close this question until the bounty expires, but will do so after that.
Comment: OP: sorry you got sucked into a debate about question formatting when you're still a new user.  The main issue is that stack exchange sites are best designed for specific questions with discrete answers rather than open-ended ones.  The latter are answered better at places like [reddit](https://www.reddit.com/r/emacs/), where you will get very extensive answers to more open-ended sorts of questions.
Comment: It's a legitimate question and is useful to new users.  I see no reason to remove it.
Comment: @Dan: I do not share your opinion on the place of *open questions*. In your opinion, are all the answers simply associated with the questions asked? No, this is obviously a biased postulate: "Emacs is a great operating system, just lacking a decent text editor". LOOOL.
Comment: @SxEequals10nminus2n: I'm basing my claim on the materials presented in [the Emacs Stack Exchange site tour](https://emacs.stackexchange.com/tour) and the explanation for [how to ask a good question](https://emacs.stackexchange.com/help/how-to-ask) which explain the sorts of questions that work well on this site.  The way this site is structured does not lend itself well to open-ended questions, for which people can get much better answers in other venues like reddit.
Comment: @Tyler: Have you ever heard of netiquette? More seriously, this question addresses a key issue *faced by every Emacs user*. Anyway, there are other ways to get to the heart of the issue: reviewing the documentation or writing bug reports.
Comment: Just because open questions are useful in general, it doesn't mean they're appropriate anywhere you feel like asking them. If you'd like to participate in a community, a good first step is learning something about the way that community works.
Comment: Having been in the OP's position on another Stack Exchange with a question I really needed help with, I must say that having an early question rejected is very off putting and drives new users away from the community.  Frankly, I find these legalistic discussions about what does and does not constitute a "valid" question to be one of the worst things about Stack Exchange.
Answer: Do you want to jump right in, or want to take your time configuring?
Distros/Starter Kits
If you want to get productive right away, it's highly recommended to start with an Emacs Distro, as it would usually have a lot of saner defaults, with some even geared towards different types of workflows.
Want a batteries-included experience that's highly-optimized for VIM-emulation? Try Spacemacs!
Want something more minimal than that? Prelude!
There's something in there for everyone. Go check them out.
Roll-your-own
If you're the type that can spare the time to learn about the internals of the tools you're using, you're in for a treat, as Emacs is the self-documenting, extensible editor. This graphic by Sacha Chua is a good place to start
Few key things to remember:
The key conventions in Emacs are different, C is for <Ctrl>, M is for <Meta>/<Alt>, etc.
Closing Emacs - C-c C-k | <Ctrl>+c, <Ctrl>+k
Cancelling commands/Emacs is "stuck" - C-g | <Ctrl>+g
Open the help menu - C-h C-h | <Ctrl>+h <Ctrl>+h

Whatever path you choose, I hope you have fun, and happy hacking
Answer: Emacs comes with a comprehensive manual which you can open with C-h r. It also has an interactive tutorial which you can start with C-h t.
Answer: This is one of these topics with no right or wrong answers. Fortunately, you didn't ask which editor is the best one. :-) I myself have been using Emacs for almost 10 years and would still consider myself advanced beginner. As some people say, Emacs isn't an editor, it's a lifestyle. There's truth in this quote, and if you don't get greedy and allow yourself some time to learn things, you will be rewarded with a fascinating piece of software.
There is an awful lot of information, and unless you like to suffer, it's getting overwhelming pretty soon. You can follow these tutorials that explain how to move the cursor in four different ways, but this is probably not what you are looking for. Telling you that there is virtually nothing that you can't do with Emacs won't help you either. Here's how I wished I started years ago.
First, try out some Emacs distributions and stay a while with the one or another. The 'Awesome Emacs' list will give you an overview, have a look at the
Starter Kit section.
Find yourself a use case. What do you want to do? Write texts? Develop software? Let's assume you want to produce elegant presentations or get a bit more organized in your everyday life: then org mode is your friend. (A lot of people came to Emacs just because of org-mode.) At some point you want to export your document, maybe you want to give a presentation. This will lead you to beamer or org-reveal. The more you want, the more you (will have to) learn. The reactions of your colleagues will be priceless when you tell them how you did it.
Allow yourself some time to learn. Using Emacs isn't just about how to do this or that, but to learn how this beast works and how to customize it so that it becomes your everyday tool for a growing number of tasks. This requires some healthy amount of curiosity, because you will have to deal with Emacs Lisp if you want to customize Emacs. Some resources for starters: 'Mastering Emacs' started as a series of tutorials and is a book now: highly recommended. Here's an article for beginners. Xah Lee's website tutorial is perhaps a bit opinionated, but nonetheless helpful. And here's a beautifully designed manual (especially the 'Mini Manual'). If you're into org-mode, try these examples.
The more you learn, the more you'll appreciate sites like Endless Parentheses or Emacs Rocks! Have a look at M-x emacs-reddit - there's always something new. You will learn what this .emacs file (or .emacs.d directory) is used for and you'll discover a lot of cool lisp code.
Emacs is an experience that will keep you busy for a while. There is no shame in failing: but if you really want to use and master it, it will change some of the ways you'll look at and deal with things.
Answer: Note: This answer is a community wiki, everyone is encouraged to contribute.

Stay informed

Emacs is constantly evolving: some features are deprecated, new ideas emerge, new applications are created...

Discover the helper functions

The GNU website has some useful information. The documentation is often available in the Info format: mastering the Emacs Info reader is an undeniable asset. Browsing the built-in documentation is useful to discover some hidden features (see C-h C-h) and become proficient.

Know the key concept for the configuration

One of the major challenges is to be able to launch commands and configure applications while maintaining control over the editor. One can quickly be completly amazed or perplexed by the multitude of functions (and other Lisp concepts), commands, user options (parameters), extensions (packages or libraries). Knowing the key concepts also helps to simplify complexity.

Relativize and keep in mind than nothing is perfect

New features may be developed or existing features may be improved but some are substituted or hard to modify. The pros and cons must also be weighed in order to make wise or essential decisions.
Answer: (I can't believe this question hasn't been closed. It's far too general for this Q&A site. A question here should not just be fishing for general "tips".  Anyway...)
Emacs Wiki is your friend.
Start with the links under Learning Emacs on the first page.
The best link there is Emacs Newbie.
The next-best link there is the page that deals with Emacs Help.
That will get you started, and more. Come back to Learning Emacs for more.
Emacs Wiki will point you to Emacs's own information about learning Emacs, in particular how to "ask Emacs" itself - the Emacs help system and manuals. And how to learn Emacs Lisp.
Comment: I can't believe you're answering this question, which is approving the bad behavior of asking such question. I can't believe I'm writing such a non-constructive comment, which also adds something to this question/post...
Comment: @PanJunjie潘俊杰: If the question is not to be closed then it deserves answers, and this is my answer. In my opinion the question should be closed, but mine is only one opinion.
Answer: Don't get discouraged, it has a very steep learning curve.  If you stick with it, it pays very high dividends.
Start with the manual:
https://www.gnu.org/software/emacs/manual/html_node/emacs/index.html
once you get a bit comfortable (you don't have to get all the way through in one go) you should consider learning how to customize it:
https://www.gnu.org/software/emacs/manual/html_node/eintr/index.html
It is built around lisp, which is well known in academic computer science circles, but, looks a little odd to programmers who only know javascript.  Try to keep an open mind (meta-programming macros will blow your mind).  A great intro to lisp (really scheme, but, they are all related) is:
https://mitpress.mit.edu/books/little-schemer-fourth-edition
The greatest thing about emacs is that you can edit the editor while you are editing (without restarting!).
Comment: Yeah, iv'e heard that! Thanks for the help
Answer: If you are a new user and still have to learn all the key-bindings you should consider doom emacs or the already mentioned spacemacs. Doom emacs and Spacemacs allow you to use vim-keybindings (using evil-mode) instead of emacs keybindings. You can setup everything yourself but I think it is still worth checking out the distros first. To be clear, I use standard emacs keybindings but I tend to believe that vim keybindings are the better choice. The problem is, if you are already used to the keybindings it can be bothersome to learn new ones. Especially if your muscle memory is well trained. Imho the keybinding question is an important one and should be asked in the very beginning (event though you might not find an answer to it).
Emacs keybindings:
In emacs, keybindings are mostly like in many other programs (just a lot more of them). You have the two modifier keys ctrl and alt (meta-key) and you have to use them a lot. For example: C-x C-s to save the buffer, C-x C-f to open a file, C-f move pointer forward, C-b to move pointer backward, C-p to move pointer to previous line and C-n to move the next line. You get the idea. With the constant use of ctrl and also shift there will be a lot of strain on your pinky, which can lead to the infamous emacs-pinky. If you still want to choose classic emacs keybindings consider remapping the ctrl to the capslock button. Also Xah Lee has some additional tips.
If you have already played around with Vim, you'll know it uses the concept of modal editing where you switch between command mode and insert mode. I am not experienced with vim but I do consider switching to evil mode because of the following reasons:

Less strain the fingers. No emacs pinky.
I do not have any prove for this, but from my general understand after reading up on it, is that vim keybinding are more efficient.
vi is installed on every linux machine, so you will always feel at home.

Why then use emacs and not vim?
Well, I bet Vim is great but I cannot tell you how great it is because I never really used it. But I can tell how great emacs is. You can configure emacs to be everything you want. You can use it as an IDE for almost every programming language, you can use it as a Latex-Editor, you have org-mode (which you should definitely check out!), you can use it for reading and writing emails and so on and so on. For me, configuring emacs is kinda a hobby of mine and I think one should see it as that. It is for people who like to play around.
Answer: Read phils's advice: through a simple example (disable the beep) he explains essential concepts.


Boltzmann's original derivation of the Stefan–Boltzmann law

Question: Does anyone here know a source where I can find Boltzmann's original derivation (using primarily thermodynamic arguments) to the Stefan–Boltzmann law (the radiant power emitted by a body in thermal equilibrium is proportional to the fourth power of the absolute temperature)? I have done some research on Google, but I have not found anything much enlightening about this.
Comment: [See here](https://en.wikipedia.org/wiki/Stefan–Boltzmann_law#Thermodynamic_derivation_of_the_energy_density).
Answer: Boltzmann built on two known properties of cavity radiation.
(1) The energy density, $u$, defined as $u = U/V$, depends only on temperature, $T$.
(2) The radiation pressure, $p$ is given by $p= u/3$.
Radiation pressure was given a firm basis c1862 by Maxwell. The factor of 1/3 arises because of the three-dimensionality of the cavity, in which radiation is propagating in all possible directions. [It's easy for us now to derive this equation by considering the cavity as containing a photon gas.]
Boltzmann (1884) used a thought-experiment in which a cavity is fitted with a piston, and we take the radiation inside it through a Carnot cycle. On a $p–V$ diagram the isothermals are just horizontal lines, because $u$ is constant so $p$ is constant. The heat input along the top (temperature $T$) isothermal is $\Delta U + p \Delta V$. This works out to be $4 p \Delta V$. If the lower temperature isothermal is only slightly lower, at temperature ($T - d T$) then the cycle appears as a thin horizontal box, and the net work done during the cycle is simply $dp \Delta V$ in which $dp$ is the infinitesimal pressure difference between the two isothermals. We can then apply the definition of thermodynamic temperature in the form
$$\frac{dT}{T} = \frac{\text{work}}{\text{heat input}} = \frac{dp \Delta V}{4 p \Delta V} = \frac{dp}{4 p}~.$$
This integrates up easily to give the Stefan-Boltzmann law.
A modern thermodynamic derivation would probably start from the fundamental equation (embodying first and second laws of thermodynamics)… $$\text {d}U = T \text{d}S - P \text{d}V. $$ Therefore for an isothermal change $$\left(\frac{\partial U}{\partial V} \right)_T = T \left(\frac{\partial S}{\partial V} \right)_T - p .$$ Using one of the Maxwell relations, this becomes $$\left(\frac{\partial U}{\partial V} \right)_T = T \left(\frac{\partial p}{\partial T} \right)_V - p .$$ But for the radiation, $$\left(\frac{\partial U}{\partial V} \right)_T = \left(\frac{\partial (uV)}{\partial V} \right)_T = u = 3p \ \ \ \ \ \text{and}  \ \ \ \ \ \left(\frac{\partial p}{\partial T} \right)_V = \frac {\text{d} p}{\text{d}T}. $$ Making these substitutions and tidying, $$ 4p = T \frac {\text{d} p}{\text{d}T}.$$ As before, separation of variables and integration gives the Stefan-Boltzmann law.
Comment: How exactly have you written dT/T = Work/Heat input?I get it intuitively, but mathematically?
Comment: @lazearoundall day. Kelvin temperature can be defined by $$\frac {T_1}{T_2}=\frac {Q_1}{Q_2}$$ in which $Q_1$ is the heat input to the Carnot engine at temperature $T_1$ and  $Q_2$ is the heat excreted at temperature $T_2$. Subtracting 1 from both sides of the equation, we can write it as $$\frac {T_1-T_2}{T_2}=\frac {Q_1-Q_2}{Q_2}.$$ Using energy conservation (or the first law of thermodynamics, noting that there is no change in internal energy over a complete cycle), $(Q_1-Q_2)$ is the work output.
Comment: @lazearoundallday Please see above comment.
Comment: @PhilipWood Could you please provide me any source containing the derivation of the relation between radiation pressure and energy density of radiatons?
Comment: @AYM Shahriar Rahman  Reif: *Fundamentals of Statistical and Thermal Physics* (End of scection 9.13), Mandl: *Statistical Physics* (Section 10.4)

Boltzmann’s original derivation of the Stefan–Boltzmann law


How to install Ubuntu with SSD and HDD

Question: I want to install Linux on my main PC but it has an SSD and a 1TB HDD, i want to know how to use the SSD only for the OS and some programs and the HDD for everything else (i use it this way on Windows 10), is this possible? If it is can someone tell me how to install it that way? Thank you
Comment: See these: UEFI/gpt partitioning in Advance:
http://askubuntu.com/questions/743095/how-to-prepare-a-disk-on-an-efi-based-pc-for-ubuntu & http://askubuntu.com/questions/336439/any-problems-with-this-partition-scheme &
http://askubuntu.com/questions/461394/how-to-partition-ssdhdd
Answer: Of course.

create unallocated space on the SSD, 20GB is more than enough.
create unallocated space on the HDD, as much as you feel is needed.
Create a partition on the SSD as ext4 on the unallocated space and name the mountpoint /.
Create a partition on the HDD as ext4 with a mount point you create yourself.
after install open a terminal and set the mountpoint to your user.
after install open a termimal and remove all the visible directories in /home/$USER/ (so not the hidden files).
edit ~./config/users-dirs.dirs and change it to your mountpoint.
put a copy of users-dirs.dirs on your HDD.

This way you keep all system related files and settings on the SSD and all personal data on the HDD.
When you re-install: format / and mount the mountpoint without formatting. Remove dirs in /home/$USER/ and copy users-dirs.dirs  on the HDD to ~./config/
Comment: +1 though depending on how many applications you have installed 20GB is not always more than enough. On my desktop where I have a similar setup / consumes about >30GB
Comment: I have a server with a 10Gb / with apache and a 500Gb+ mysql database: basically user data is stored elsewhere. Just with software that you actually use you will never hardly reach 20Gb.

How to install Ubuntu with SSD and HDD


I Need to force windows to the front So I can dump Hasp Dongle on program that runs at boot

Question: I am trying to dump a hasp dongle on a popular arcade machine. I can only get a portion with the game not running. If I ctrl alt del while game is already running I get a memory crash. What is the best way to proceed? Is there a way to get my dumper or even a cmd window forced to the front? Arcade game uses windows XP sp3.
Comment: what about Ctrl-Shift-Esc?
Comment: can you boot from a cd/usb flash?
Comment: I can boot from hirens boot cd and edit registry. I can even start programs from the registry, but they sit underneath. I need to enter my hasp key and change a drop down then click dump to get my dongles mem dump. (can terminate program while it counts down to start using task manager, but I need dump while its running. when it starts it fills screen) Is there a syntax perhaps to force dumper on top via registry? Ctrl-Shift-Esc is a no go as well.
Comment: Anyone? If i can just get to my window I can do what I need to do.
Answer: If you are able to run an application, this C# example will get you started. It will allow you to change the z-order of the application automatically, by calling SetWindowPos with HWND_BOTTOM as the parameter.
This will send the topmost window to the bottom of the z-order and you should be able to place new windows above it.
You need to identify the window handle of the topmost application (if you know the title of the application window, you can use FindWindow), or you can find the window handle by using EnumWindows and GetWindowModuleFileName
This will require you to be able to execute an application on startup. However since you said you are able to edit the registry you could put this executable on the system and set it to run at user logon, shortly after the launch of the application you are interested in.
Comment: I am not sure how I would run any of this to find the window name, is there a good program that can run in the background and catch the info, and send to a log file?
Comment: Use `EnumWindows` and `GetWindowModuleFileName` to (1) retrieve every Window visible on screen, and then pass that window handle to `GetWindowModuleFileName` to get the path to its executable. Then compare it to the known path to the executable you are expecting. If you have a match, then you know you have the correct Window handle. Then you can pass it to SetWindowsPos with HWND_BOTTOM parameter. You'll have to modify the linked C# example (or write your own application) to accomplish this.
Comment: ok thx, I will download visual studio and give it a go
Comment: I am thinking it will probably crash just like when I ctrl alt del and it looses the focus. Not sure what will prevent that. There is an entry in its registry ForegroundLock Timeout with a hex value of 30d40 might that be of any help?
Comment: Yeah the window method did not work, it simply crashed the game again. I have no issue disabling the game. I was able to dump the dongle key by stoping the game. Problem is I am only getting a partial dump. The stuff thats in the memory that I need is comming up all zero's.. The particular dumper that is working for me is GUI only as far as I can tell. I looked for command line options but did not find any. That would be too easy lol. I will check out this Autoit. If its capable of selecting drop down menus, entering text fields (for keys) and hitting the dump button that would be nice
Answer: This is more of a SuperUser question, but if you can boot from CD and edit the registry the following options come to mind:

boot into a WinPE environment, hopefully it will be enough to run the dumper
Find where the game is started and disable it; this should allow you to run the dumper unimpeded
figure out if the dumper has commandline options for automatic dumping and use them to dump without the UI
use something like AutoIt to manipulate Dumper's UI to perform its work.
Comment: Yeah the window method did not work, it simply crashed the game again with a memory address could not be written error. I have no issue disabling the game. I was able to dump the dongle key by stoping the game. Problem is I am only getting a partial dump. The stuff thats in the memory that I need is comming up all zero's...
Comment: Also, I cannot install anything on the machine directly, It will simply delete it apon reboot, or will fail to install. I can put programs on via another computer, and run them through the registry. Any dumping I do has to be done via a flash drive, or it will not be there
Comment: sounds like you need support from the dumper's author, I don't see how we can help here. It all seems to have very little to do with RE itself anyway.


Positivity of semiclassical pseudodifferential operators

Question: Let me first give some background. (My reference is Martinez's book An introduction to semiclassical and microlocal analysis)
Let $m\in\mathbb{R}$, and $p(x,\xi):\mathbb{R}^n_x\times\mathbb{R}^n_\xi\to\mathbb{C}$ be a symbol in $S_{2n}(\langle\xi\rangle^{m})$. That is, regarded as a function on $\mathbb{R}^{2n}$, $p$ is smooth, and for every multiindex $\alpha=(\alpha_1,\ldots,\alpha_{2n})$, there is a constant $C_\alpha$ such that $|\partial^\alpha p|\le C_\alpha\langle\xi\rangle^m$. Here $\langle\xi\rangle:=(1+|\xi|^2)^{1/2}$. Associate to such $p$ and small parameters $h>0$ we define the (Weyl) semiclassical pseudodifferential operator ($h$-PDO) $$\mathrm{Op}_h^W(p)u\,(x)=\frac{1}{(2\pi h)^n}\int e^{i(x-y)\cdot\xi/h}p(\frac{x+y}{2},\xi)u(y)\,dy\,d\xi\quad(u\in C^\infty_c(\mathbb{R}^n)).$$ I'm concerned with the validity of $\mathrm{Op}_h^W(p)\ge 0$, that is $\langle\mathrm{Op}_h^W(p) u,u\rangle_{L^2}\ge 0$ for all $u\in C^\infty_c(\mathbb{R}^n)$. The following result is well-known.

Sharp Gårding inequality If $p\ge 0$, then there exists a constant $C>0$ such that $$\langle\mathrm{Op}_h^W(p)u,u\rangle_{L^2}\ge -Ch\|u\|_{H^{m/2}}^2\tag{1}$$ for all small enough $h>0$ (i.e. for all $h$ smaller than some positive constant depending on $C$) and for all $u\in C^\infty_c(\mathbb{R}^n)$.

When $m=0$ (in fact, I don't know if this is needed), the Fefferman-Phong Inequality improves the result to $\langle\mathrm{Op}_h^W(p)u,u\rangle_{L^2}\ge -Ch^2\|u\|_{L^2}^2$. However, $\mathrm{Op}_h^W(p)\ge 0$ is still not guaranteed.
On the other hand, the Easy Gårding inequality replaces the assumption $p\ge 0$ by $p\ge p_0\langle\xi\rangle^m$ for some constant $p_0>0$, and the conclusion is $\langle\mathrm{Op}_h^W(p)u,u\rangle_{L^2}\ge C\|u\|_{H^{m/2}}^2$ for every $0<C<p_0$ (the larger $C$ is chosen, the smaller $h$ is required). Thus, $\mathrm{Op}_h^W(p)\ge 0$.

Question. If $p\ge 0$, and there exist constants $p_0>0$ and $R>0$ such that $p\ge p_0\langle\xi\rangle^m$ for $|\xi|\ge R$, is it possible to add some "smallness" assumption on the size of the zero set of $p$ to guarantee $\mathrm{Op}_h^W(p)\ge 0$?

The model example in my mind is $p\in |\xi|^2\in S_{2n}(\langle\xi\rangle^2)$. In this case $p=0$ only at $\xi =0$ (precisely, on $\mathbb{R}^n_x\times\{\xi=0\}$). We cannot apply the Easy Gårding inequality, while $\mathrm{Op}_h^W(|\xi|^2) = -h^2\Delta\ge 0$, since $$\langle-h^2\Delta u,u\rangle_{L^2} = h^2\int |\nabla u|^2.$$
Here are some more concrete questions:

Is it true that $\mathrm{Op}_h^W(p)\ge 0$ if, besides the assumptions given in Question,  $p=0$ only at a single $\xi$?
How about $p=0$ on a small set in $\mathbb{R}^n_x\times\{|\xi|<R\}$, say with small Hausdorff dimension?
If yes, are there generalizations to systems (matrix-valued $p$)?
Or there are counterexamples for these questions?

Indeed, the case of matrix-valued $p$ is crucial for my current research. But any partial answer or relevant references will be appreciated.
Comment: The related question https://mathoverflow.net/questions/99867/criteria-for-positivity-of-pseudoddifferential-operators-on-manifolds and the paper of Fefferman and Phong mentioned there seems to shed some light on some of your questions.
Answer: The Wick quantization has the property you are interested in. This article by N. Lerner about the Wick pseudodifferential calculus may be of interest to you.
Concerning the earlier post mentioned by Dylan, please be warned that the 1982 paper by Fefferman and Phong, which was refered to in the accepted answer to that post, defers the proof of a crucial Geometrical Lemma to a more complete version of their article. Perhaps the completion is contained in the (very long) 1983 paper The Uncertainty Principle by Fefferman, but I am not sure.


External Azure Active Directory

Question: In Azure, I have invited some external users via their corporate email addresses and they are now visible in our AAD, the source being listed as External Azure Active Directory. I do not know if they had to create a new password when they clicked the link in the email invitation.
My question is this: If we add one of these external users to security groups or apps in Azure and they later on leave their job (and have their email accounts closed), will their access to whatever we have granted them access to be terminated as well?
In other words: Are external accounts in AAD dependant on them being active in their own ADs, or are they merely copied to Azure AD upon invitation (our users' full names as they appear in their email accounts' name field are automatically shown in the same way in our Azure AD) and thus active until we actively remove them or restrict their access?
Answer: An external accounts belonging to another Azure AD tenant is dependant on that tenant identity lifecycle i.e. its owner won't have access to that account - and therefore to your tenant - when and if the organization it belongs to terminates the account.
Consumer accounts (hotmail.com, outlook.com) are not subject to an identity lifecycle.

External Azure Active Directory


What incident of theft are the brothers of Joseph referring to in 12:77?

Question: In the story of Joseph (12:77), when the cup is found in Benjamin's bag, the other sons of Jacob say this about him:

"If he steals - a brother of his has stolen before."

Who are they referring to? And what happened in that incident?
Answer: They are talking about Joseph (عليه السلام) as Benjamin was Joseph's full brother, as they both were sons of Jacob (عليه السلام)  and Rachel. While the remaining brothers were his half siblings, their father was Jacob but their mothers were Jacob's other wives and concubines named Leah, Bilhah and Zilpah.  See Tahreer wa't-Tanweer.
The exegetes have narrated the following traditions as explanations for the accusation against Joseph by his brothers:

They were referring to the belt of Isaac (عليه السلام) . This belt was inherited by Isaac's daughter, the sister of Jacob, and who was the paternal aunt of Joseph. She had raised Joseph when he was an infant. When Joseph had grown a little older, Jacob intended to take him back. However the aunt loved Joseph too much and asked to keep him. Jacob refused and so she planned a trick to retain Joseph with herself. She made Joseph wear the belt of Isaac and then pretended that it had been lost or stolen. The family searched for the belt and eventually it was found in Joseph's possession. According to their laws a thief was made the slave of the victim (also seen in verse 75), and hence the aunt gained custody over Joseph for the remainder of her life, which Jacob accepted. A similar trick is later employed by Joseph to keep his brother Benjamin with him in Egypt.

They were referring to the idol owned by Laban, the maternal grandfather of Joseph. Joseph's mother Rachel had instructed him to steal and destroy the idol. Doing this was permissible.

They were alluding to an incident when Joseph had taken some food from the family's table and gave it to a beggar, without seeking his father's permission.

They were lying and their slander had no basis whatsoever.

Ref: Tafsir al-Tabary and Tafseer al-Maawardi
Answer: They are referring to Joseph accusing him also of theft. No such incident occurred with Joseph nor he was involved in any theft. Below explanation from Tafsir Ibn Kathir.

(If he steals, there was a brother of his who did steal before.) They
tried to show themselves as innocent from being like Binyamin, saying
that he did just like a brother of his did beforehand, meaning Yusuf
(peace be upon him)


Get NewForm.aspx Controls and Events (jQuery)

Question: I have been able to hide/show form controls using JavaScript.  Is there a way to capture jQuery events on these controls?  For instance, I want an onclick function to work on my form control.  How would I go about doing something like this?  Is there a similar function like the _spBodyOnLoadFunctionNames where I will be able to trigger events on specific form controls?
Answer: To use jQuery you will need to know the control ID in question so you can add your own handlers.
The simplest way I've found to do this is to examine the DOM of the page in question using the debug console of your browser (F12) and then using the inspector tool to select the control and find the id.
You could then have your jQuery document.ready function associate your own event handlers to the controls in question.
Here is simple example:
$(document).ready(function(){
    $('#button').on('click', function(){
    //do whatever should happen on click
});
});
Where #button is the control ID of a Sharepoint control (I.e. A button, etc.).
Comment: Yay! Good job.  Now if they could all be this quick :)
Comment: I have tried does not seem to work. $('.ms-formbody:input[id $=TextField]').click(function() { alert("clicked")});
Comment: Just to eliminate the obvious go ahead and add the selector in using just the ugly looking id of one of your controls. Also make sure this code runs after the document has loaded (using the document.ready function) by putting an alert in that function (just to make sure document.ready is getting called and not erroring due to some silly javascript error)
Comment: I got it!  Looking for wrong attribute type worked with title!  $(document).ready(function() {

$("input[title *='BEMS ID']").click(function() { alert("clicked")});

});
Comment: Probably will work like you suggested too. I think I might have had a syntex error. Thanks for the help a bunch! Have an upvote and a solved :)


Open record details in a panel within a Visualforce page

Question: I have written a bootstrapped page that has a custom list view panel on the left side of the page and an output panel on the right side of the page. I have the left panel figured out where different list views are shown based on a dropdown. I'm better at front-end development than back-end logic. How can I write my code so that when I click on a record's name in the left panel the record will open in the right panel? Any sample code you could provide would be greatly appreciated.
Answer: You can place an iframe in the right panel and page in the iframe that takes record Id as the parameter.
When a record name is clicked in the left panel you can passe the record Id to the page in right Panel, which will then reload with all the required details for that record


The Requirements of a Cryptographic Algorithm

Question: I remember reading a book on cryptography with a section detailing the objectives that modern cryptography must accomplish, one being that even if the algorithm is known, the method remains secure. I.e. the so-called Kerckhoffs's principle. What are the other standards an algorithm must accomplish and why are they necessary?
Answer: What you are referring to is Kerchoff's Principle. Beside that a couple of formalizations of security criteria (along with very simplified explanations) are:
Ciphers

Indistinguishability under chosen-plaintext attack (IND-CPA)
Indistinguishability under [adaptive] chosen ciphertext attack (IND-CCA1 & IND-CCA2)

These roughly say that ciphertexts should not leak information about the plaintext, and that plaintexts should not allow an adversary to infer anything about their corresponding ciphertexts. Some more details here.
MACs and Digital Signatures

Strong existential forgery under chosen message attack (SUF-CMA)
Weak existential forgery under chosen message attack (WUF-CMA)

See page 11 of this paper. These roughly describe the ability of an adversary to forge a signature for a given message without having knowledge of the signing key.
Hash Functions

Collision resistance
Preimage and second-preimage resistance

These roughly say that given the output of a hash function it should computationally intractable to find the input to the function that produced that output or to find two values that produce the same output when fed through the hash function.
Comment: To round up puzzlepalace's great answer: yes, there are some broad "mantra recommendations" that one should keep in mind at any moment in crypto ("don't roll your own, don't rely on security through obscurity", etc.). Those are important "common sense" recommendations, but the most strict and important requirements usually depend on what you intend to achieve. Integrity and confidentiality have many instances, and there is little benefit in generalizing rules instead of considering each case specifically.
Comment: Your answer has "Strong existential forgery under chosen message attack" twice.
Comment: In both WUF-CMA and SUF-CMA we have access to a "tagging oracle" i.e. we can get valid tags for messages we submit to the oracle. in WUF-CMA we can reuse these tags and and try to to create a message for which one of these tags is valid. For SUF-CMA the tag may not be one of the tags that was returned by the oracle.
Comment: @puzzlepalace :  Your last two sentences have "tag(s)" and "message(s)" backwards.


Adding noise function to a channel model

Question: I have noise function and I want to add it to my own channel model, where can I get more information about the channel model other than the documentation.
Answer: You should check out the "Developing custom channel models" section of the developer's guide. The AbstractAcousticChannel is perhaps your best starting point. You only need to implement 4 methods to customize this class to your needs:

double getRxPower(Reception rx)
double getNoisePower()
boolean detect(Reception rx, double snr)
int decode(Reception rx, double snr)

The first two methods estimate the signal power and the noise power. The second two methods take in an SNR (signal/noise power ratio) and estimate whether the frame can be detected, and how many bit errors the frame will have.
An simple version of this customization realized by delegating some of this functionality is illustrated in "Extending AbstractAcousticChannel" section.
Comment: when I run model it  shows following error    **`  java.lang.NoSuchMethodError: org.arl.unet.sim.channels.UrickAcousticModel: method ()V not found `** @Mandar Chitre
Comment: @DEEKSHITHNS – Did you manage to resolve this? Seems like an incorrect constructor. I saw you have another post on this, which I responded to.
Comment: yes, the answer in the other post solved the problem, thank you, sir.


Sharing Multi-dimensional Arrays across different forms in VB

Question: I have a very simple 2D array, it holds a list of song titles, their genre, and their runtime.
frmMain loads the array from a text file and allows me to manipulate it and boil it down to a desired (implicitly sized) playlist. i want to THEN pass that playlist array to a second form, frmPlaylist
The problem i'm running into....When frmPLaylist calls the Property from frmMain I receive an error that VB cannot convert the string value to a two dimensional array.
Simplified...frmPlaylist is all locked and ready to receive a 2D array, but frmMain seems to only be sending a single string variable.
Here's the code i'm working with if it helps.
on frmMain
Public ReadOnly Property PlaylistOut() As String
        Get
            Return mstrTimedPlaylist(,)
        End Get
    End Property

on frmPLaylist
  mstrTimedPlaylist2 = frmMain.PlaylistOut()

Comment: And `mstrTimedPlaylist` is declared as?..
Comment: Private mstrTimedPlaylist(,) As String
Answer: Public ReadOnly Property PlaylistOut() As String(,)
    Get
        Return mstrTimedPlaylist
    End Get
End Property


Iphone 12 battery

Question: I bought my new iphone 12 from Apple store yesterday and the sales person told me that the battery was charged from the factory and it was ready to use. However when I got home and tried to turn on the phone, I found that the battery was zero charged. Why my new iphone wasn't charged like other mentioned that A new iPhone comes with around 50% charge on its battery before first use? Is there anything need for concern?
Answer: I wouldn't worry. The battery was surely charged, but somehow it got turned on and drained. The device shuts itself down to protect the battery for months, so I would let it charge for an hour and then set it up.
After 2 hours, it should be well past 80% charged and if you notice anything, open a case with AppleCare so they have a receipt and record if it being flat when you opened the box. An unlikely event would be you seek service later, better to have this documented within a week of purchase "officially".
This usually is a total non-event, though.

Iphone 12 battery