Safest bet for monthly billing dates when paid bi-weekly

Question: So while the best answer is to budget (along the line of the answers to this question) and use a second, preferably interest-bearing, account to even out the pain of monthly bills, I'm curious if anyone has come up with a programmatic way of determining two days at opposite ends of every month that fall within different paychecks on a given year's bi-weekly (26 pay period) schedule?
Comment: Sure, but are you looking for months that have three paychecks, or just the date ranges for each paycheck?  I did bi-weekly budgeting in Excel for many years but I'm still not cure exactly what you're trying to do.
Comment: I'm not sure what you're asking - can you give a concrete example of what you're looking for and how you intend to use it?
Comment: For example, on a bi-monthly schedule, you knew your first paycheck (or transfer to secondary account) covered bills with dates 1-14 and your second paycheck (or transfer) covered 15-EOM. When you move to bi-weekly, there are two extra paychecks per year, constantly shifting your payday as a date of the month.
Comment: Trying to avoid manual budgeting in Excel ;-)
Comment: Any two days 14 days apart (e.g. 1st and 15th) will be in two different bi-weekly pay periods except when Feb has 28 days.
Answer: This boils down to a cash flow management problem and there are software solutions for this out there.  I am unsure of cost or quality, but that is the gist of the problem you are trying to solve.  The software probably makes use of some operational research math, which is pretty intensive and not well documented in order to maximize cash flow.
There are much simpler, short cut ways of doing this.  One is to always have at least one paycheck in your checking.  Another might be to have the largest series of bills that are due in a single 14 day period in the checking.  There are a few others, but in my opinion they all run too close for comfort.
The reality is that people regularly suffer minor unexpected expenses.  Some refer to these as emergencies, but that word gets used far to freely for things that should be expected.  Rather than turning those emergencies into disasters (by borrowing to solve them) it is better to have cash on hand.  Without that cash on hand it makes it hard for a person to move forward in their financial life.
Additionally there was an academic study that was published recently that showed that cash on hand had a high correlation to a person's financial happiness.  This WSJ article might provide a link to the study I was thinking about.
Some may think that this does not answer the question.  I think it does:  You should not be cutting it that close.  Have some cash on hand.  At least 1000, perhaps more depending on your stage of life.  You will be happier, and you will meet your goals quicker.
Comment: I agree with the spirit of your advice (and would recommend >1000 for any adult) but you're right, this is not the specific answer I was looking for. :-)
Comment: I avoided this advice in my answer, but my own method is to allocate money earned in the current month for spending in the next month. That means I keep 2 paychecks in reserve (I'm paid semi-monthly) in my checking account at all times before moving much of that money to long-term savings when it does finally get allocated in the budget.
Answer: If you're trying to make sure that your big expenses don't fall into the same two-week pay window, just use the 1st and the 15th, that will ensure that your big expenses are separated into the two paychecks. Whether the bill is due early or late in the pay period shouldn't really matter.
Comment: @DStanley, one year the paychecks come on Feb 1, Feb 15, so that second check falls into the same pay period as Mar 1 bill, but the following year the paychecks come on say Feb 2, Feb 16, the bill from Feb 1 falls into Jan 19 paycheck, the bill from Feb 15 falls into Feb 2 paycheck, and the bill from Mar 1 falls into Feb 16 paycheck. This is only a problem roughly every 14th year.
Comment: I like the simplicity here - N+1 where N is the period between paychecks. Will hold for any other answers before accepting. Thanks!
Comment: @DStanley Since the pay could rotate across all the days 1-14, then 15-28, it only happens occasionally. Maybe that's when the emergency fund comes in handy...
Comment: @NathanL I see what you're saying.  I stand corrected.
Answer: Some credit unions (especially ones that serve aerospace workers) offer loans with bi-weekly repayment plans.  These plans are designed for people who receive bi-weekly paychecks.


Different tints (opacities) of a spot colour as separate discrete swatches in the swatch panel?

Question: In Indesign is there a way to setup various tints or opacities of the same Pantone Spot colour as separate discrete swatches? It would be helpful for me as I would like to set up a Data Merge function that would actively search out different tonalities of said spot colour swatch in an automated way.
Comment: What software are you using? I supposed InDesign in my answer becasue that's my app of choice. ^^'
Answer: Select the PMS color that you would like to save a tint of.
Open your Color Palette and set the percent of the swatch to the percent that you would like to save.
Click on on the stacked lines in the upper right of the Color Palette and select Add to Swatches.

The tint will now show up in your Swatches Palette like this:

You can repeat this for as many tints as you want.
Answer: Yes, these are called 'Tint Swatches'. Select your Pantone Swatch, set its tint to a non-100 percentage, then open the Swatches palette's options. You should be able to choose the 'New Tint Swatch' option there.


How is it possible to hear something at 44.1Khz?

Question: Since our hearing range is said to be 20Hz to 20,000Hz. So, how can we possibly hear something at 44.1Khz? Or do we hear only half of the sound produced at 44.1Khz by any audio CDs? What is going on?
Answer: The 44.1kHz it's the sampling frequency, i.e. the frequency at wich the encoder samples the audio data. It has nothing to do to the frequency of the audio data.
You can generate a 1000Hz sine wave, sample it at 44kHz and play it back: what you hear is still the 1000Hz sound. Take a look here.
Actually there is a reason to why CD audio data is sampled at 44kHz, that is slightly more than double the maximum frequency humans can hear.
It's because of the Nyquist-Shannon sampling theorem which states that:
<code>If a function x(t) contains no frequencies higher than B hertz,
it is completely determined by giving its ordinates at a series
of points spaced 1/(2B) seconds apart.
</code>
In layman terms, just sample at double the maximum frequency of the audio to get an "accurate" reproduction of the original signal.
Comment: Yes, I know this, exept for what you call "not just pure sine waves". Do you mean that we percieve soundwaves above 20 000 Hz and even though we can't really hear it, it gives an impact?
Comment: Speaking from experience, recording at 44.1 kHz / 48 kHz is somewhat of a moot point. 48 kHz is used for film and TV due to its (now much) easier synchronisation with video framerates, whole numbers ftw. Professional studios equipped with sufficient quality gear will now opt for a higher bitdepth - 24 bit recording either at 44.1 kHz or 88.2 kHz (if they can capture those frequencies, and it's worth it). They'd only usually opt for 48 kHz / 96 kHz if they knew they were going to be providing an eventual mixdown primarily for film or video.
Comment: @50ndr33 well, professional recordings use sampling rates of 96kHz or more. That's because 2 times the frequency is the *theoretical minimun*. And when you record music you don't have just *pure sine waves*, but lots of harmonics/overtones which colour the sound (think a distorded electric guitar). Take a look at http://en.wikipedia.org/wiki/Oversampling. Also, the quality of the Analog-to-Digital converter has a role. With a professional AD @ 44.1kHz you will record with better quality than with a cheap PC soundcard @ 48kHz or 96kHz.
Comment: Good answer! You said that 44100 hertz is slightly more than double the maximum frequency humans can hear. Why then do you get so much better quality if you record it at 48 000 hertz? (Yes it is strange if you look theoretically at it, but I think for example the drums sound dull and the brighter "air" sounds dull on 44.1 kHz.)
Comment: @50ndr33 well, i really don't know if we "perceive" >20kHz soundwaves but sure they interact with the udible ones contributing to create a "rich" sound. If you play a 440 Hz (that's the A note) sine wave it just sound *sterile*, and surely not as the same A played on a piano or on a violin, or on a guitar, etc..
Comment: Yupp, that's an interesting theory. You're probably right!
Comment: The standardisation on 44.1 kHz is not purely related to the average ear's range of detection, it's also to do with sync with audiovisual equipment. See the Audio CD's Wikipedia article: http://en.wikipedia.org/wiki/Compact_Disc#44.1_kHz_sample_rate. As has been said already, provided the equipment used to record and play back is of sufficient high fidelity, frequencies above 20 kHz will allow for more harmonics and ultrasonics which can improve the imaging and realism of instruments. You 'feel' the sound.
Answer: Good answer Mr Shunz.
The Wikipedia article you included has this passage:

... however in some cases ultrasonic sounds do interact with and modulate the
  audible part of the frequency spectrum (intermodulation distortion).

For an explanation of Intermodulation Distortion (IMD), see
http://en.wikipedia.org/wiki/Intermodulation#Intermodulation_in_audio_applications
In the top-right figure there, the signal at the lowest frequency could fall in the hearable range (< 20 kHz). This peak could be lost in an ADC-process (analogue to digital conversion) if the sampling rate is too low. That is one of the reason hard-core audio-enthusiasts cherish all-analogue audio; from the recording studio, via the LP and to the speakers.
Comment: That's right... but actually the greatest argument against audio CD format is not the 44kHz sampling rate, but the 16bit *depth* which has "not enough headroom". That's why nowadays most digital recording is done at *at least* 24bit resolution.
Comment: @MrShunz: 24bit is useful for recording, because it gives you room to move with effects and mixing. That says nothing about end-user bit depth requirements (which is what CDs are for, if you need more depth than that, for remixing or what ever, get the masters). Do you have any evidence that 16 bit is not enough for hearing? If so, post an answer over at http://avp.stackexchange.com/questions/9039/what-is-the-resolution-of-human-hearing
Comment: @naught101 I'm not saying that 16bit is *not enough*, I'm saying that **criticism** of CD format is towards *bit depth*, not sampling frequency. I.e. 44.1kHz is good enough to reproduce the audible frequencies, but 16bit gives you "only" 93dB of headroom (so compression must be used to keep things from distoring etc etc.)


Can we question about topic in Quran? I mean publicly scholars would say Islam is all about questions bt when we ask they say accept what is written

Question: For eg
Beating of wives is not acceptable..but when i question it they would give me answers unacceptable.
Similarly women not allowed to marry non muslim men when we question it they say accept what it is written
Lastly, of marrying slave women there are no slavery system now so was that verse for that period.who decides that?
If that verse was for that period why can other verses be not for a period?
Comment: Yes, you can ask questions about Islam and what's in the Quran. Even the Sahaba have done so to the Prophet. What many Ulema say is there r some concepts that may not be in our grasp due to lack of knowledge or Iman and that we have to accept what is in the Quran. For eg the Quran is quite accurate in it's description of the stages of an embryo but it is highly unlikely humans 1400+ ago understood the concept like we do today due to advances in medical science There are many instances where all the 3 questions you pointed out above have been asked. Please use the search option on this forum.
Answer: There are different types of questioning.
Firstly, one can question the veracity (truthfulness) of a claim seeking evidence. Did God forbid women from marrying non-Muslim men? He did, and there is much evidence that can be presented. This is the allowed type of questioning, but it is necessary for people to accept the truth after the evidence is presented.
Secondly, one can question something other than the veracity. In modern times, this has usually manifested itself in questioning the ethics of something in light of liberal values.
An example would be: Liberal values indicate that men and women are equal, so anyone who treats them unequally is bad. Islam treats them unequally. How is this acceptable?
This is a type of questioning that is useless and forbidden. It presupposes baseless things (men and women should be treated equally; Why should they be? According to whom?), then questions Islam based on that.
It is not interested in the truth of whether God did command something. It is more interested in trying to force God to command something that conforms to this person's desires.
When scholars say Islam accepts questions, they are talking about the first. Islam accepts and welcomes questions about evidence. How do we know Islam is from God? How do we know this or that command is commanded by God?
No one cares about questions that are not about evidence. Why doesn't Islam treat men and women equally? This is a useless question. Why should it treat them equally in the first place? Because feminism is the flavor of today?

Lastly, of marrying slave women there are no slavery system now so was that verse for that period

The verse is still applicable today even if slaves don't exist right now. If slaves began to exist in the future, it would apply.
The prerequisites for a command to come into play not existing is not the same as the command not existing.
For someone to have a concubine from slaves, slavery needs to exist. But, the concept of having concubines does not cease to exist just because slavery currently does not exist.
I will give an example: Imagine that pork no longer exists in a country. Would it be proper to say the prohibition of pork no longer exists? It wouldn't be proper.

If that verse was for that period why can other verses be not for a period

The verse was not for any time period. It is for all times. If slavery existed right now, the rules of slavery would still apply. Just like that, the rules of marriage apply as long as marriage exists. We do not limit any rules to a certain time period.


Boundary estimation using statistical techniques

Question: Do you know a good methodology to estimate the boundary between two sets? Here are the specifics of the problem:

I am studying a recursion defined as
$$ 2(n+q) x_{n+2}= (r(n+q) +s)x_{n+1}+((2-r)(n+q)-s)x_n$$
with $x_0=0, x_1 = 1$. I am interested in identifying when
$0 < \lim_{n\rightarrow\infty}|x_n| < 1$. More specifically, for which values of $(q, r, s)$ this is occurring. I actually solved this problem here, and the problem itself, even its solution, is irrelevant.
Let's pretend that we observe the points as in the above picture, let's pretend we don't even know how they were generated, and the goal here is to find the boundary between the red dots and the blue dots (red dots correspond to convergence, blue dots to no convergence.) I know the exact shape of the orange border, so this is a good example to benchmark boundary estimation techniques. But let's pretend that we don't know the exact boundary.
My question
What are the modern techniques used by statisticians to solve this problem?
Important notes
If the domain is convex, usually the convex hull is a good estimator. But what if it is not convex (in my example, it is barely convex, and in addition, non-bounded.) If the points were on a grid, there are plenty of techniques available, but here sample points are not on the grid. What about using density estimation techniques, assuming the points are uniformly distributed on some unknown domain to be estimated? Keep in mind that here, the domain is NOT bounded, so rather than a uniform density, one might look at the intensity of a 2-D or 3-D Poisson process on some unknown domain.
This is a actually 3-D problem. I only displayed one slice here (corresponding to $s=2$), but ideally, I am looking for a technique that works in 3-D. One could also treat this as a clustering problem, or better, a regression problem where the goal is to estimate the shape of the orange contour. The regression could be something like $f(q)=a_1 + b_2 r$ after some appropriate transformation $f$ that needs to be identified. Here $f(q) = \frac{1}{q+2}$ but you are not supposed to know it, the physics of my problem suggests that this is the correct transformation. How would you perform such a regression since most of the dots (far away from the border) must be discarded?
Answer: This is called a classification problem, ie to any $(r,q)\in R^2$ we want to assign a most likely label (namely red or blue). With a nonlinear boundary, some of the available methods are $k$-nearest neighbours, support vector machines, or Gaussian process regression (logit or probit typically).


How to access Windows 10 PC from Ubuntu 14.04 using Remote Acess Client like Remmina

Question: I have a laptop with Ubuntu 14.04LTS and my friend has Laptop with Windows 10. How should I configure both these laptop so that I can access Windows desktop from my Ubuntu? Specifically how should I configure Windows so that it can be accessible from Ubuntu and vice-versa?
Answer: I also was initially unable to connect to Windows 10 from Linux, but found a change to the Windows configuration and a reboot fixed it. There are actually several potential clients. You'll probably like remmina since it's friendly and GUI based, but I prefer the scripting friendly command line based xfreerdp because I can set it to reconnect as I prefer and include my credentials. Here's the command I use:
xfreerdp /u:'email@example.com' /p:'mypassword' /sound:sys:alsa /size:1900x1050 /cert-ignore ignore certificate /v:192.168.0.1

See: https://ubuntuforums.org/showthread.php?t=2287213
With reference to: https://cyberarms.net/security-insig...e-desktop.aspx
I changed the registry key
\HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp SecurityLayer

from DWORD Hex '2' to a value of '1'
This reduces the security resilience of the windows machine but allows older software to remote in.
Comment: Do you need Windows 10 PRO for this to work?
Comment: Use https://github.com/stascorp/rdpwrap/ if you are running Home edition - or want multiple connections to a Pro edition
Answer: You can use Remote Desktop connection which is a feature in windows 10 and will let you connect to a computer which is on the same Network as yours, if you want to access his computer through the internet you would need to set up a VPN. You can also use a software like Hamachi to simulate a virtual network between you and your friend which is a very easy to configure and use.
To connect to the Windows machine you can use remmina. To connect from your windows machine to the Ubuntu machine you can use SSH or if you want a Graphical interface, VNC can be used.
You would first need to Enable Windows Remote desktop on the windows 10 PC. If you're on the same network as the PC, open remmina and choose the RDP protocol. Input the WIndows 10 IP and you should be able to connect. If you're trying this over the internet then you would need to setup a VPN like i said previously, which can be easily done with Hamachi.
Comment: Added explanations, guides to setting up Hamachi and VPNs are all over the internet. Also, be sure to use the RDP protocol in Remmina.
Comment: Can you elaborate the procedure? Because I tried with remmina but enable to connect to windows 10 PC
Answer: I accomplished this by installing tightVNC on the Windows computer and connecting with remmina.  You must open a port in the router to allow incoming connections to tightVNC.  The particulars are spelled out in the tightVNC documentation, not elaborating here since it's Windows.
You can then connect through remmina using the VNC protocol.
I cannot answer the Windows->Linux part of the question.  Although I could speculate that if you run vino on your Linux machine and open the appropriate port, your friend could connect with tightVNC.
Comment: Note that this will reuse the existing screen and not create a new session (login).


How to properly strip silicone wire insulation?

Question:
The silicone high temperature double (fiberglass weave?) insulated wire is not getting stripped by wire strippers because it is very soft and seemingly molded onto the wire. How can I remove the insulation properly to prepare for crimping?
Comment: Si jackets can be pulled off with fingernails much easier than with PVC jackets.
Comment: What type of wire strippers are you using?
Comment: I used a self-adjusting wire stripper that typically works well. The issue is that this insulation is very soft. Even with a sharp knife, I can't remove all the insulation; rather, part of the insulation scrapes off like butter, leaving other parts still molded on the wire, between wire strands, etc.
Comment: Looking at that wire it looks like it has been over heated. All the high temp fixture wire I have is smooth and usually strips fine for me, I pull the fiberglass back and then strip I do not use automatic strippers, if yours are adjustable you need to increase the jaw tension. Do not try to use the strippers to cut both the fiberglass and the Teflon.
Comment: @EdBeal Hmm.. it's possible it has been overheated, since the thermal fuse blew. If that softened the insulation and molded it around the wire, it could explain the situation. It really seems stuck onto the wire, not peeling off. Yes, I first carefully cut the fiberglass insulation with a scalpel before trying to strip the silicone insulation.
Answer: Try using the next smaller hole on your wire strippers but make sure you don't score the actual conductor. If that doesn't work, use a utility knife and cut from the tip of the wire back down to the white insulation, going around the conductor. If the strands unravel a bit, don't worry, just twist them back after you've scraped the silicone off.
Comment: @adatum  Try wiping it down with mineral spirits.
Comment: @adatum  Never tried that but should work.
Comment: I used a self-adjusting wire stripper. I also tried cutting or scraping the insulation off with a sharp knife, but it does not come off in one piece or even chunks. The soft insulation practically gets smeared or sliced off, leaving other parts embedded around the wire and between strands.
Comment: Such as lighter fluid?


Can they legally falsify paternity on an obituary?

Question: My boyfriends daughter died. He is her legal father and by blood, he is on the birth certificate. As well as paternity established. Her mother did the obituary and listed her boyfriend the father/parent. Is this legal? I have read its illegal to post a false public document, is an obituary considered a public document? How can we have it changed and his name put on it. The funeral home knows she is lying. The director of said funeral home is dodging my boyfriend calls. What can he do?
Comment: Obituaries lie all the time.  They say what a wonderful, loving person the deceased was, when everyone knows what complete tool they really were :)
Comment: Laws vary around the world. If you would like a specific answer to your question then please add the relevant jurisdiction tag (country, province, state etc). Also, where was this published - in a newspaper or an official document?
Comment: This is not, in my view, a request for specific legal advice (RSLA).  But I will edit it to make it more clearly generic. This should not be closed as a RSLA, in my view.
Comment: Columbus Ohio the funeral home. The funeral director posted the obituary knowing they man on the obituary wasn't the father
Comment: Specific legal advice is off topic here, but you could ask your question or questions more generally.  For example, "is an obituary a 'public document' that is illegal to falsify" (I'm pretty sure that the answer is "no, public documents are things like birth certificates").  You might be able to gain some legal leverage through defamation law, but I doubt it's worth pursuing (the argument might be that the false obituary damages your boyfriend's reputation because he is known by many to be the real father).
Comment: I suppose you could file a lawsuit but to what end?  After a long time and much money you might win and they'd have to publish a correction on the back page of the paper.
Comment: Where is this obituary published? In a printed or online local newspaper of record? Or on the funeral home's business website?
Answer:
My boyfriends daughter died. He is her legal father and by blood, he
is on the birth certificate. As well as paternity established. Her
mother did the obituary and listed her boyfriend the father/parent. Is
this legal?

Realistically, yes. It is probably legal.
The majority rule is that one can't bring claims of defamation or intentional infliction of emotional distress/outrageous conduct, on behalf of the dead. In particular, in Ohio, the Ohio Revised Code § 2311.21 states that actions for libel and slander will end upon the death of the plaintiff. So, no legal relief may be sought on behalf of the deceased daughter.
The mom's current boyfriend presumably consented. There is a fair reading of "father" that includes psychological or god-father figure as opposed to legal parent, under which the statement would not be false.
Nothing is said about the true father so it isn't really an outright defamatory statement about him that harms his reputation.
If the obituary were used as a basis for receiving some sort of economic death benefit, like a social security survivor's benefit or insurance proceeds, it might be a case of common law fraud or something similar, and would also probably constitute criminal fraud or theft. A false statement in a probate court filing would likewise be sanctionable, either by the presiding probate court judge, or in a criminal proceeding (although probably not in a separate civil lawsuit).
Arguably, it might meet the standard of "outrageous conduct/intentional infliction of emotional distress" (whether something meets that threshold if all facts alleged are true is a question of law, rather than a jury question), but generally that would require a calculated intent to harm the true father as opposed to, for example, an intent to make that daughter's funeral go smoothly if she had many friends who assumed that the mother's boyfriend was the father, so probably not. Public policy generally favors not having the courts intervene in obituary omissions or inaccuracies.
It is certainly not a crime.
Not all untruths have legal remedies.

I have read its illegal to post a false public document, is an
obituary considered a public document?

No. An obituary is just a private publication, it has no official status. I would agree with the following source that states that:

There are no legal requirements tied to obituaries. They're a way to
tell the story of a deceased family member, and they only carry
sentimental value. Obituaries are not a legal or financial obligation
under any circumstances.

(Source: Do You Legally Have to Have an Obituary or Death Notice?)

How can we have it changed and his name put on it.

You can't.

The funeral home knows she is lying. The director of said funeral home
is dodging my boyfriend calls. What can he do?

Take out his own obituary in a newspaper or some other medium of his choosing setting forth the true facts. If the original was published in a newspaper, ask the newspaper for a correction or write a letter to the editor commenting upon it.
Generally speaking, the First Amendment is designed to encourage responses by counter-speech, rather than by legal action.
For example, in one notable case, the Texas Supreme Court's ruled upon whether the authors of an obituary about their son could sue for defamation when someone else accused them of including false statements of fact in the obituary. It held that the authors of the obituary could not successfully sue the people making the counter-statement to their obituary. The Dallas Morning News v. Tatum, Case No. 16-00984 (Tex. May 11, 2018) (affirming a summary judgment order dismissing the defamation lawsuit brought by the authors of the obituary).
Footnote
Most of the litigation and notable cases involving false obituaries relate to obituaries for people who aren't actually dead.
Comment: I have read some close to 500 daily newspapers looking for obituaries from 1918 in the last weeks trying to estimate the impact of Spanish Flu in a region, and I must add: Most obituaries are telling just about enough to try and identify a single person with their name and death date, and possibly some kind of cause, job and at times the closest family's names (e.g. parents, wife, siblings), but they are telling nothing compared to a statistic compiled by what is best described as the Medical Examiner of a neighboring city on the topic. And they tell nothing about who a person was.
Comment: News story addressing a similar case (unresolved on the merit): https://www.npr.org/2022/02/15/1081018419/bob-saget-family-lawsuit-records
Answer: An obituary is not a public record under Ohio law, see ORC 149.42. Anyone is free to publish a false statement, up to the point that it constitutes fraud, deceptive advertising, or defamation (I'm not going to give a list of all of the legally-prohibited false statements, these are the most relevant). "Advertising" relates to commerce in goods and services, so has no applicability in this situation. Likewise, "fraud" relates to making a false statement in order to induce a person to do something of value based on a material claim: not demonstrably applicable. Defamation is a false statement that harms the reputation of another. This is the one thinly-possible angle for legal action. A patently false statement would be "Smith is not the biological father of Sally", which could then subject Smith to public humiliation – a classic cause of action in defamation. The statement "Jones is the father of Sally" could arguably imply the patently false statement, but also could have a literally true interpretation (Jones functioned as the father-figure to Sally). The courts would then look all of the facts and determine whether a reasonable person would interpret the obituary as making the patently-false statement. On the face of it, that is not a reasonable conclusion, but that is a determination that would have to be made in court.


Writing free-form versus creating a plot online?

Question: I've always preferred creating short stories, and novels naturally. I don't normally create plot summaries, chapter summaries, and so forth. Is it best to always create a plot summary and chapter summary with at least key plot points before digging into actual writing?
Answer: It is best to do what works best for you (and you will have to try). People (and writers) are different, and what works for one need not work for another.
If you find that what you write without plan is reasonably well structured and without disabling plot holes that make rewriting and cleaning up a nightmare there is no reason why you should insert an unnecessary additional step into your process just to satisfy the authors of how to write books.
If on the other hand you find that the result of you happily writing along falls below your expectations you might profit from however much planning helps you avoid whatever went wrong. You'll need to analyse your works, maybe get feedback from readers, and then find appropriate strategies. These might include defining the end, setting up certain key events, writing a premise or logline, drawing charts, or whatever. I once wrote a novel guided by a series of photographs as landmarks. There is no generally applicable advice, and you'll have to experiment to find your own ideal procedure.
Answer: An outline or summary is planning. As is character profiles, event lists, setting notes, language notes, maps, roleplaying, and anything else you do understand the story before you write it. How much planning is needed varies from none at all to months of planning for hours of writing. Some factors that affect how much planning is needed are length, complexity, abnormality, number of authors, memory and writing speed. The longer the story the more details to be confused, and the same with complicated plots esoteric theories and other complications. If you can't remember the whole story for long enough to write it down, you need notes. If you are working with someone else, you need to plan to make sure everyone has the same plan. Abnormality? The more different a story is from what you know, the more you need to plan.


How do I stop chrome from auto completing search text in the search bar with previously searched text?

Question: I can't figure out how to stop chrome from adding on words to things that i've typed before in the search bar. for example, i have searched for "navy beans nutritiondata.self" previously. Now whenever i start typing "navy bean"... it completes the thing I typed before, "navy beans nutritiondata.self", so I have to press back space in order to just search for "navy beans". I already turned off "use a prediction service to autocomplete text in the search bar, which was found under settings/advanced/privacy. Any help?
Comment: Have you looked at the related questions in the "Related" list (on the right)?
Comment: I just did. I saw a similar topic, but i don't think it was actually resolved, and they are trying to do something a bit different than me.
Answer: It's a common issue but the Chromium team has always refused to provide a way to disable the inline autocomplete "feature":

"the code and UX complexity of this is nontrivial because inline
  autocompletion is the central design feature around which all other
  omnibox decisions are based."
  https://bugs.chromium.org/p/chromium/issues/detail?id=667922#c8

I encourage you to create a report at https://bugs.chromium.org/p/chromium/issues/list (click the "New Issue" button near the logo) to ask for that feature.
Maybe if enough people do that, they'll consider providing that option.


maximum daily reputation and top users score

Question: If I get 30 upvote in answers with a particular tag, does it calculate 30 score for me in top users section  or just 20 score ? ( considering maximum daily reputation of 200 for upvotes )
Comment: Tag scores aren't capped.
Comment: I didn't understood what you meant,sorry, can you explain a little bit more?
Comment: Looks like a diamond moderator specifically notes [here](http://meta.stackexchange.com/a/52792/189840) in the comments that all votes are taken into account, regardless of whether you've hit the cap.
Comment: Im really sorry, but what does **cap** means ?
Comment: Ah sorry. By "cap" I mean the daily reputation limit. Do you want me to pull out the relevant comments into an answer here?
Comment: Well, [this kind of proves](http://english.stackexchange.com/tags/phrase-requests/topusers) what @Dennis said - 117 score for answer posted two days ago. :)
Comment: another question, when exactly in day will top users list update?
Answer: Alright, I'll go ahead and pull out my comment into an answer.
As noted in the comments here:

@yes Only upvotes and downvotes, and only the corresponding score. It
  has no effect to or from reputation, so things such as votes that give
  no reputation due to the reputation cap, they still count. –  Grace
  Note ♦ Jun 1 '11 at 18:19

and a little further down

@yes123 Score is not derived from reputation, as mentioned in my
  previous comment, so it is not affected by the reputation cap. –
  Grace Note♦ Jun 2 '11 at 15:07

Plus, as @ShadowWizard notes, @Gamemorize's score on English Language & Usage in the "phrase-requests" tag, as shown here, is currently 117 (and will be 150+ once it updates again), but the only post with a nonzero score was made just two days ago.
This pretty much definitively shows that the Top Users score is not affected by the daily reputation limit.
Comment: another question, when exactly in day will top users list update?
Comment: so, I got my answer earlier in comments, but as you are the only answerer here, I gonna accept yours ;), thank you


Position of specific value

Question: Let's assume a have an arbitrarily long number, take π for example. Since we know π is infinite, there will at some point be a group of numbers like "2015201620172018...", correct? My question is, for any arbitrarily long number, is there a mathematical way of determining the position of a specified set of numbers in said long number? The only conceivable way I can think of is similar to how we find the coefficient of x using the binomial theorem, but that leaves the problem of determining the number in the format of a binomial expansion.
Comment: $\pi$ is a finite irrational number, so with an non-recurring decimal expression. Not all irrationals have every finite sequence of digits in their decimal expression.  Even so, for most of those which do, there is no shortcut for finding the first location where a given sequence appears (if you think there are an uncountable number of such numbers and a countable number of shortcuts)
Comment: Does this answer your question? [Does $\pi$ contain all possible number combinations?](https://math.stackexchange.com/questions/216343/does-pi-contain-all-possible-number-combinations)
Comment: "*...similar to how we find the coefficient of $x$ using the binomial theorem...*"  That problem and this are completely different and have absolutely nothing to do with one another.
Answer: A string being infinite does not necessarily mean any finite string is included in it. Take for example the decimal expansion
$$\frac{1}{3}=0.333\dots$$
Clearly there are an infinite number of decimals, but that does not mean that you can find any finite string of numbers you want in there. Furthermore, the answer to your question is that no, there is no way to do so for any arbitrary number which satisfies the conditions you need. Indeed even proving that a number has such a property is an extremely difficult thing to do to begin with.
Comment: I should have explained better, I meant to include that I am not talking about rational numbers(because of the problem you have pointed out above) but for any irrational number, there should be sequences that occur due to their infinite nature, sort of like how the library of babel works(every possible combination of every possible character)
Comment: @DéjanVenter That's not necessarily true either. See the answer to [this question](https://math.stackexchange.com/questions/216343/does-pi-contain-all-possible-number-combinations).
Comment: @DéjanVenter $0.10110111011110111110111111\dots$ where we continually append ever-increasing lengths of $1$'s between individual $0$'s is an irrational number and yet it does not have any digits other than $0$ or $1$ appearing... and notably doesn't have even the substring "2" appearing in it, much less "2015201620172018". Go back and revisit the *actual* definition of irrational numbers and do not conflate them with other unrelated concepts like "normal" numbers.

Position of specific value


Is it okay for this wire/cable to be hitting my pedal?

Question:
This little piece is sticking out. This is my first bike and I was wondering if it's a problem or I should try and attach it to the bar or if it's okay to be like that?? Help I'm new to the bike world.
Answer: Your picture isn't exactly clear but it looks like the cable with crimped ferrule from the front derailleur.
If it is hitting your crank arm as you pedal, the cable is too long and needs to be cut shorter with a new ferrule crimped to the end. Any bike shop should be able to do that procedure for little or no money.
Just do not try to cut it shorter with wire cutters; shifting/brake cables are very tightly stranded and need a very sharp, bypass-style, cutter to make a clean cut. The crimped ferrule is paramount to prevent fraying at the cable end.


How do I prolong my family tree and get Generals in Rome Total War?

Question: What increases the chances of having sons in Rome Total War? I need them for heavy generals ( I have 76 daughters and 3 living sons). Is there a "Special" trait that would allow me to have more sons and to continue my family chain?
Comment: Some one sent you daughters when you asked for sons...
Comment: @bwarner probably because ~73 of his sons died.
Answer: Of the available Traits that affect fertility, there are none that are gender specific.
Given that you have so many daughters, you should be getting offers from prospective husbands. That is assuming that your daughters are of age and not already married (or widowed).
Answer: The only reason for having more probability of sons is getting more territories, even if one of your general is Infertile can still have sons.
Fertility trait is believed to increase probability of having children, but only affects the chance of the new child belonging among the living generals of your family.
I have tested many configs on Rome TW, and those are my impressions about this topic. Try also to not lose your generals too often.
Comment: @youngguilo Each game turn all eligible characters have a chance to reproduce. A character with the Infertile Trait, just has a lower chance.
Comment: How can a general receive kids if he is infertile? It would make the game contradict itself.


2006 Daihatsu Terios: What does this button do?

Question: There an image of 4 wheels, the top 2 are tilted and there's a cross between the top set and the bottom set. I pressed it once and it made a noise that was less than pleasant and the car was revving weirdly. It took me 30 minutes to turn it off because pressing it again didn't work.
I'm driving a 2006 Daihatsu Terios
Comment: Welcome to Motor Vehicle Maintenance & Repair! Was there supposed to be an image? Just put the URL in the body of the text and we can help you get it added if it doesn't want to play.
Comment: Updated with link to photo
Answer: That button is for the centre diff-lock.
The "normal" 4wd setting is the engine power is biased 60/40 to front / rear.
Once traction is lost, and any one wheel spins you are stuck.
Locking the centre diff "fixes" the drive to front and rear so if the rear has traction you will move, or if only the front has traction, again you will move.
However, if one front and one rear spin you are now stuck...
This should not be operated at speed on the hard-top and only in slippery conditions.
If it makes lots of noise then get it checked.
Comment: Thank you so much for this, i think it made noise because i was trying to drive normally (50+km/h). Now I know what it is I will probably never need it, but thank you again for answering my question.


Page migrated error in Graph API

Question: In my Facebook application, when I query info about a Facebook page through the open graph API, I regularily see errors like <code>(#21) Page ID 290260024371666 was migrated to page ID 122581454447308.  Please update your API calls to the new ID</code> when querying the open graph API.
What is this migration? How do pages migrate to another? Is that something that can happen anytime?
Comment: https://www.facebook.com/help/?page=213602951994043
Comment: Thanks, but that's not it. This error is about a page (not a profile) migrated to another page.
Answer: Can happen anytime when user merge his fanpage with a other page of similar name.
Happens also for Places movie and many other object.
Would be nice if the Graph Api would return a extra field with new PageID .

Page migrated error in Graph API


Sacrificial Anodes and Pit Corrosion

Question: I have a slab of aluminum and one part of the slab will be exposed to a very corrosive environment. If I put a sacrificial anode elsewhere on the slab will the section that is exposed still be protected from pit corrosion? I guess I'm unsure because the pit corrosion is a result of a localized reaction and if an anode is added will it prevent the local reaction from taking place.
Comment: What this 'corrosive environment' would be?
Comment: Its essentially a small puddle of slightly acidic fluid.
Answer: Generally speaking, there is no protection unless the sacrificial anode is immersed in the electrolyte. It might be better to anodize and seal the aluminum, which should protect it against most acids. There are many aluminum anti-corrosion treatments, but in any case the area under attack would have to be covered. See http://en.wikipedia.org/wiki/Anodizing.

Sacrificial Anodes and Pit Corrosion


Unauthorized access was denied or security settings have expired javax.net.ssl.SSLException: certificate_unknown when creating MobileFirst runtime

Question: I'm installing a v7.0.0 MobileFirst Server with Liberty 22.214.171.124 with Java 1.7.0 on RedHat in Nonadminstrator mode.  Steps I have followed:

Successfully install Liberty, create a server and verify it starts with no errors in messages.log.
Install MFP Server.
Use the MFP Server Configuration Tool to create an MFP configuration using the Liberty server.
Bounce the Liberty server and verify it starts with no errors.
Create an MFP Runtime using the Server Configuration Tool.
Bounce the server and observe SSL errors in the log.

The SSL errors seem to be related to Liberty trying to talk to the JMX REST client - at least that is my assumption since I haven't even invoked an adapter yet.
The WAR file I am using for the Runtime comes from a project that builds and runs fine in the MFP Studio Liberty development server.
The full log can be found at https://www.dropbox.com/s/o1frf7pjszm46n6/messages.log?dl=0, but here's the relevant error:
[8/4/15 18:23:09:400 CDT] 00000050 com.ibm.ws.channel.ssl.internal.SSLHandshakeErrorTracker     E CWWKO0801E: Unable to initialize SSL connection. Unauthorized access was denied or security settings have expired. Exception is javax.net.ssl.SSLException: Received fatal alert: certificate_unknown
at com.ibm.jsse2.o.a(o.java:6)
at com.ibm.jsse2.SSLEngineImpl.a(SSLEngineImpl.java:409)
at com.ibm.jsse2.SSLEngineImpl.a(SSLEngineImpl.java:469)
at com.ibm.jsse2.SSLEngineImpl.j(SSLEngineImpl.java:181)
at com.ibm.jsse2.SSLEngineImpl.b(SSLEngineImpl.java:176)
at com.ibm.jsse2.SSLEngineImpl.a(SSLEngineImpl.java:495)
at com.ibm.jsse2.SSLEngineImpl.unwrap(SSLEngineImpl.java:66)
at javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:23)
at com.ibm.ws.channel.ssl.internal.SSLUtils.handleHandshake(SSLUtils.java:870)
at com.ibm.ws.channel.ssl.internal.SSLConnectionLink.readyInbound(SSLConnectionLink.java:531)
at com.ibm.ws.channel.ssl.internal.SSLConnectionLink.ready(SSLConnectionLink.java:304)
at com.ibm.ws.tcpchannel.internal.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:174)
at com.ibm.ws.tcpchannel.internal.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:83)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.requestComplete(WorkQueueManager.java:504)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.attemptIO(WorkQueueManager.java:574)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.workerRun(WorkQueueManager.java:929)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager$Worker.run(WorkQueueManager.java:1018)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:906)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:929)
at java.lang.Thread.run(Thread.java:796)

Comment: The error is an SSL issie - javax.net.ssl.SSLException: Received fatal alert: certificate_unknown.
at com.ibm.jsse2.o.a(o.java:6). Maybe because the HTTPS port of the Liberty server is used by another server ?
Comment: Still waiting to hear from you.
Comment: Sorry, traveling this week and haven't had a chance to give this much attention.  I did take a quick look and do not see any port conflicts nor firewall issues.
Answer: Solved it.  I went back to a system I knew worked and started looking for differences.  The configuration was all the same, but I noticed the working system used
java version "1.7.0"
Java(TM) SE Runtime Environment (build pxa6470sr7fp1-20140708_01(SR7 FP1))
IBM J9 VM (build 2.6, JRE 1.7.0 Linux amd64-64 Compressed References 20140627_204598 (JIT enabled, AOT enabled)
J9VM - R26_Java726_SR7_20140627_0924_B204598
JIT  - r11.b06_20140409_61252.04
GC   - R26_Java726_SR7_20140627_0924_B204598_CMPRSS
J9CL - 20140627_204598)
JCL - 20140707_01 based on Oracle **7u65-b16**

The system that was throwing the SSL errors was running
java version "1.7.0"
Java(TM) SE Runtime Environment (build pxa6470sr6fp1ifix-20140220_01(SR6 FP1+IX90136+IX90137))
IBM J9 VM (build 2.6, JRE 1.7.0 Linux amd64-64 Compressed References 20140106_181350 (JIT enabled, AOT enabled)
J9VM - R26_Java726_SR6_20140106_1601_B181350
JIT  - r11.b05_20131003_47443.02
GC   - R26_Java726_SR6_20140106_1601_B181350_CMPRSS
J9CL - 20140106_181350)
JCL - 20140103_01 based on Oracle **7u51-b11**

I installed 7u65-b16 on the new system, restarted Liberty under that version of Java and all seems to be well now.
Comment: @William, I'm sorry but I ran into this issue over 5 years ago at another company and haven't worked with MobileFirst Server since. I don't really have any relevant context to give you, sorry.
Comment: Thanks for the update. From the log it seem to be an issue with the SLL certificate of Liberty. Some errors say that the certificate is unknown (could be that the JCL is missing a cypher used by the certificate ?).  But line 2472 it says 'unable to find valid certification path to requested target' so could be a missing authority cert needed by the certificate.
Comment: Yes, these SSL errors threw me off for quite a while.  The resolution to the runtime startup issue was to upgrade to Java 7u65, but later I found that I got "No negotiable cyber suite" errors when my adapter tried to connect to a server over TLS 1.2.  Updated to Oracle Java 7u80 and that was resolved.
Comment: Hi @DSchultz_mo, could you provide more details about the solution ? I am facing the same issue. Do I need to uninstall something before ?
Comment: @DSchultz_mo, Don't worry. Thanks for your reply.


Package files not downloading on an account without privileges

Question: I'm on a uni campus pc which is pretty locked down without admin privileges so when my document requires a particular e.g. <code>\usepackage{enumitem}</code> file it never downloads it. Do I have to manually search the net, find it and put it into the directory where I'm creating my LaTex file? I have many such directories, do I need copies in each?
Comment: missing admin rights is normally not a problem, but time outs due to proxies, firewalls or vpn tunnels etc can disturb the on-the-fly installation. You could try to download the packages manually and setup a local repository: http://tex.stackexchange.com/a/16675/2388
Comment: In MiKTeX, there is a user and a admin package manager, can you use the user one? You might also want to have a look at [MiKTeX documentation: Integrating Local Additions](http://docs.miktex.org/manual/localadditions.html). As a last resort, there is [How can I manually install a package on MiKTeX](http://tex.stackexchange.com/q/2063/35864).
Comment: the `enumitem` package is a pretty "standard" one -- it's included in tex live, miktex, and all other distributions i'm familiar with.  it seems like the tex installation at your uni is either old, or not a full installation.  in that case, it's probably best to talk to the system administrator responsible for the tex installation and at least find out why.  explain that the tex installation doesn't include files that are expected to be part of any good installation, and this will affect more users than just you.  then hope that the sysadmin is sympathetic (not guaranteed).
Comment: @barbarabeeton this looks like the situation. I don't believe the admin knows how it should be installed because I had to prompt them for the installation of the latex.exe and pdflatex.exe files etc. What exactly should I ask for? I've already asked for the full miktex intallation to be installed...
Comment: unfortunately, if you're limited to a uni pc, you're in essentially a hostage situation.  a full miktex installation sounds like the most effective approach here.  even better would be if this could be run from a server, so anyone on the system could benefit.  the miktex distribution is internally consistent, quite complete, and comes (i believe) with convenient installation tools.  (i'm not a miktex user, so can't quote from experience.)  hoping you're not the only latex user at the university, i suggest trying to find a sympathetic faculty member to support your request.  good luck.
Comment: Does a portable installation (e.g. http://miktex.org/portable) help you? Perhaps on a USB flash drive
Answer: I have a similar Problem writing my bachelorsthesis in a company. If you don't need too much packages, the easiest way is to search them manually an store them in the folder of your .tex document.
If you have write access to the program folder, you can store them there:
<code>    C:\Programme\MikTex\tex\latex\... (WinXP example)
</code>
and update the database on:
<code>    Start->MikTex->Maintenance->Settings->Refresh FNDB
</code>
The Packages are only text files, which don't need much space. If you have one folder with your standard packages just copy them in each folder.
If you search them manually, you can use:
<code>    Google: enumitem filetype:sty
</code>
so you don't have to search in all the results.


Best window before FFT ? (for a signal consisting of 2 tones used for phase measurement)

Question: I am doing phase measurments by transmitting and receiving tones (100 kHz and 16 kHz simultaneously). I am transmitting the tones  and receiving them, applying Blackman Harris window and doing FFT for phase measurements.
I feel the Blackman Harris window is not optimal for a signal that has only 2 tones but don't know which windowing function is better for phase measurement for such a signal.
Any Ideas?
Comment: Are you restricted to using the FFT for determining what would be best for measuring rhe phase of the two tones?
Answer: Using an FFT to measure phase for just two tones results in a lot more processing that doing the following alternate approach that can be either streamed or processed in blocks. No windowing is needed:
Apply the received signal as the input to two multipliers. Apply a normalized local copy of one tone as the second input to one of the multipliers and a normalized local copy of the other tone to the other. The low pass filter of each output will be an estimate of the phase given by$A\cos(\theta)$.
For full 360 degree phase resolution, use a complex local tone and two complex multipliers with two outputs (I, Q) with the phase determined using atan2(Q, I).   (This is essentially the operation in two bins of the DFT).
Comment: I considered the complex multiplier approach, but the allowed error is very low, less then 0.01 degrees.
Comment: There is no loss in accuracy with complex multiplier and atan2, and you can average the output for best processing gain assuming stationary input (and weight the average by input envelope if varying to be an optimum matched filter in white noise conditions)
Comment: Your error will be limited by actual noise including your own quantization noise if fixed point.
Comment: @Kurtul Also note due to small angle approximation ($\sin(\theta) \approx \theta$) the SNR required to have less than 0.01 degree rms accuracy is (convert degrees to radians and take -20 log of that) :     $-20 \log10(0.01 (2\pi/360))$ = 75 dB.  From this you can specify your sampling rate, quantization, filtering requirements etc.


What does x sign mean in functions

Question: I came across this cross sign when reading a book. Does anyone know what does this mean in the context of a function?
Comment: Possibly https://en.wikipedia.org/wiki/Cartesian_product
Answer: As @zkutch says, this refers to the cartesian product of two sets.
Its definition has to do with sets, not with functions. The formal definition is as follows:
For two sets $A,B$ we define
$$A\times B:= \{(a,b)\mid a\in A, b\in B\}$$
Which is the set of all tuples from A and B.
In the context of functions, it might be simpler  to think of this as: a function $f:A\times B \rightarrow C$ essentially takes two arguments $a,b$ and spits out a $c$. This will now be written like that:
$$f(a,b)=c$$
Essentially its the same as accepting a tuple $(a,b)$, so you can rest assured this is exactly the formal mathematical definition for set cartesian product here.

What does x sign mean in functions


How do gas turbine engines and turbofan engines keep constant compressor side rpm?

Question: How do the RPMs stay constant in a gas turbine engine? For example in car with piston engine, when you keep pressing the accelerator the rpms keep picking up, to keep the rpms constant you must let off the throttle, if you keep the throttle floored you will reach peak powers rpm and even go higher rpm if engines max rpm isnt limited at peak power. My question is that how do gas turbine engines can stay at peak power rpm while still throttle is fully applied? Shouldnt it keep increasing in rpms like car engine?
Comment: "in car with piston engine, when you keep pressing the accelerator the rpms keep picking up" -> when I do that in my car in highest gear on the Autobahn, the RPMs will eventually stop increasing before reaching peak power and I've reached my top speed. I think your premise is somewhat flawed, probably by always driving your car well below top speed.
Comment: @Bianfable In autobahn its because majority of cars top gear are overdrive. you will reach your top speed way before you reach peak power in top gear because rpms are so low. If you are on 1st and 2nd gear etc you will easily reach peak power rpm and keep going up from there still until you hit the rev limiter. My cars engine makes peak power at 6000 rpm but if i keep pressing accelerator it easily goes to 6500 rpm which is the limit. I added the constant speed prop tag because i thought maybe the answer would be because they are similar but i really dont know
Comment: Modern engines use https://en.wikipedia.org/wiki/FADEC. Here's a video explaining the implemtation that's quite good.  https://nescacademy.nasa.gov/video/135553bc3b7b4171b7c54ee0578489211d
Answer: The reason that car piston engines and turbine engines seem to behave differently is that they're used in different ways.
If ran at full throttle with no load, both types of engine would accelerate to their maximum RPM (limited either by internal friction or by a fuel control unit). However, if you place either type of engine under load, they will both accelerate more slowly, and it will take much longer to reach that point.
Airplane engines and car engines are used differently. During takeoff, the engine is usually accelerated to full throttle as soon as the takeoff roll starts, and is left there until the airplane has sufficient altitude. This is plenty of time for it to reach its maximum RPM, and stay there. On the other hand, cars have a much more restrictive speed limit than planes (relative to what their engines can do), so the driver usually takes their foot off the accelerator long before the engine has enough time to reach its RPM limit.
This is easily seen by looking at the behavior of piston airplane engines. When I take off in a rented Cessna 172 with a piston engine, I advance the throttle to max, and the engine rapidly climbs to its maximum RPM and stays there. It doesn't continue to accelerate, even though the "accelerator" is floored. (And it doesn't have a fuel control unit, or indeed any kind of computerization at all.)
Comment: @TimothyScherer It stays at that RPM because the load on the engine precisely balances the power output. As RPM increases, the wind resistance of the propeller increases. Eventually, you reach a point where the engine can't produce enough power to overcome the resistance, and the RPM stabilizes at that point. A car in first gear presents a very low load to the engine, which would be roughly equivalent to a piston plane engine with no propeller attached. In those situations, the plane engine would behave very much like the car-in-first-gear engine: if you have the throttle up,
Comment: Also, yes, the fact that there's less fuel at max RPM limits the power output of the engine, whether it's a turbine, aviation piston, or car piston. This is, in fact, *why* it limits the amount of fuel, because having less power is preferable to blowing up the engine, and thus having *no* power.
Comment: it would over-rev until it either hits the rev limiter (if it has one) or until it suffers damage (if it doesn't have one). On the other hand, if it does have the propeller attached, it behaves analogous to a car in *high* gear, where the engine will eventually reach a balance point between the load and power before it hits the limiter.
Comment: Yeah but why does it stay there? For example in car if you floor it in 1st gear you will soon reach the max rpm and hit the rev limiter. if rev limiter didnt exist it would keep revving even more and damage the engine. The ecu just cuts off fuel to prevent overrevving but this also means its also no longer making as much power because fuel delivery is now decreased. It will just bounce off the limiter. Do plane engines also limit fuel delivery to keep it at steady rpm? If so, isnt that basically decreasing their power output because now there is less fuel? Sorry my question is a bit confusing
Answer: In a car, you virtually-always operate with the engine far below its power-limited RPM; this is usually not the case in a jet-engined airplane.
In both a piston-engined car and a jet-engined airplane, if you apply a certain amount of power (by pressing the gas pedal a certain distance in a car, and by moving the throttle lever through a certain angle in a jet), the engine will accelerate until it reaches an RPM where the power available at that throttle position is just sufficient to keep the engine spinning at that RPM (i.e., the amount of power needed to counter the forces trying to slow the engine down is equal to the amount of power the engine is currently generating).  Once it reaches this power-limited RPM, the engine will then operate at a constant RPM until either the throttle setting is changed (altering the amount of power available from the engine) or the forces resisting the engine's rotation change (altering the amount of power needed to counter these forces).
You can see this on a car, too, not just on an airplane.  If you sit in a car with its engine idling, and then lightly press the gas pedal, deflecting it by a small amount, and hold the pedal at this deflection, the engine (and car) will accelerate up to a certain RPM and then level off at that RPM, just like how moving a jet's throttle lever to a certain position and leaving it there will cause the plane's jet engine(s) to accelerate to a certain RPM and stay there.
The difference between cars and airplanes in this regard is that most automobile drivers virtually never use maximum throttle for more than a second or two, if that.  This is because, if you floor the gas pedal on a car and then hold it floored, the engine, and the car, will accelerate until the car is far above the speed limits on most roads before the engine stabilizes at its power-limited RPM.  The steady-state throttle setting that corresponds to the car moving at a speed that doesn't earn its driver a speeding ticket is a fairly-small fraction of the maximum throttle setting, and it's fairly-hard to hold a specific fairly-small gas-pedal deflection constant with one's foot (especially since car gas pedals, unlike airplane throttle levers, automatically return to the idle position when released, requiring one to apply a constant fairly-small amount of pressure to the pedal in order to hold a constant fairly-small pedal deflection); it's much easier to allow the engine's power (and its RPM, and the car's speed) to decay somewhat, and then, once the power/RPM/speed's fallen past a certain level, push the gas pedal down to deliver a brief pulse of higher power to reaccelerate the engine (and the car) - a pulse that is brief enough that the engine never reaches its power-limited RPM before you let off the gas pedal again.
In contrast, maximum throttle is frequently used for up to several minutes at a time when flying jets (as it provides the best margins of safety for takeoffs and go-arounds), leaving plenty of time for the engine to stabilize at its power-limited RPM.  Additionally, with jets, even when using less-than-full power, there are two major factors that make picking a certain throttle setting and allowing the engine to stabilize at its power-limited RPM for that throttle setting a much-more-practical course of action in most flight regimes than providing periodic throttle pulses (as in a car):

If you move an airplane's throttle lever to a certain position and then release it, it stays at that position (instead of trying to return to idle, as with a car's gas pedal), making it much easier to keep the throttle in the same position for long enough for the engine's RPM to stabilize.
Gas-turbine engines have much slower throttle response than the piston engines found in most cars; due to the massive rotational inertia of a jet engine's large, heavy compressor and turbine rotors, it takes much longer to speed up or slow down when the throttle setting is changed.  This slow throttle response makes supplying periodic brief pulses of power much less practical than with a piston-engined car.

What all this means:

In a piston-engined car, when you apply high throttle, you generally release the gas pedal long before the engine stabilizes at its power-limited RPM.
In contrast, in a jet-engined airplane, when you apply high throttle, you generally keep the throttle lever at this throttle setting for way more than enough time for the engine to stabilize at its power-limited RPM.
Answer: Pretty early on in the development of jet engines they realized that it was necessary to limit fuel to prevent runaway RPM.  For this reason RPM is governed by a Fuel Control Unit that meters fuel according to certain parameters such as RPM, throttle position, temperature, pressure, etc.  Even at full throttle the FCU is set up to limit top RPM.
Comment: @TimothyScherer I see. I may have misunderstood the question, then. Though, in my defense, if the question really was just "Do jet engines have FCUs?", then I would argue that it was poorly worded.
Comment: This answer isn't correct. The OP was asking about the difference between turbine engines and piston engines. Piston engines are *also* susceptible to runaway RPM if they have no load, and thus *also* have some kind of Fuel Control Unit that limits top RPM.
Comment: @HiddenWindshield, the OP apparently disagrees with you.
Comment: @HiddenWindshield Yeah the ecu just cuts off fuel when you hit the rev limiter. My question was basically how did gas turbines and jet engines etc also coped with this situation of overspeeding and Michael Halls answer provided the answer.
Comment: Thank you, this is what i was looking for. Other answer doesnt make any sense. One thing i am also wondering though, since you cut off fuel supply to limit rpm to not let it overspeed, isnt that also decreasing the maximum power/thrust? For example AGT-1500 gas turbine engine in m1 abrams tank makes 1500hp peak power but if the governor  cuts the fuel to prevent it from overspeeding , would it not make less than 1500hp? Or is 1500hp the advertised hp after rpm settles with the governor cutting the fuel delivery?
Comment: ah yes i think  i have worded it a bit poorly my bad
Comment: @TimothyScherer: can you please update your question to be more precise then? This question/answers exchange will be accessible to many people for many years to come and they also deserve to understand it
Answer: ALL these engines will runaway, if load is abruptly removed
What keeps RPM at sensible numbers is that usable power (load) is kept balanced with the fuel supplied.
There are a number of X-factors depending on the application.
A turbofan is going through thick air, which places considerable load on it.  The fan is directly coupled to the N1 shaft.  It would be extremely unlikely for the fan to unexpectedly start ingesting the vacuum of space, and that's what would be required for the load to suddenly be removed.
Now the N1 shaft could break and you bet that would cause an overspeed event.  Similarly a helicopter or turboprop transmission could snap, or the prop could simply be feathered the wrong direction.   In that case you have some sort of rev limiter, or a proper governor that changes  fuel flow to try to reach and stay at the target RPM.
Most diesels and small engines have these governors built right in.  You don't actually work the throttle on a bulldozer or lawnmower engine, you are telling the governor to seek a different target RPM. The fuel rack sticking wide-open is death to a diesel.
With gas cars, someone could jab the clutch or shift the automatic into neutral. In automobiles you have a simple rev limiter that knocks out the spark, though these days they like to knock out fuel also. You would never have that on an airplane, but absent a feathering mistake a runaway is unlikely due to that thick fluid the prop is always pushing. Same for a marine waterscrew.
With stationary turbine generators like the LM2500, the reactivity of the AC power grid is going to force it to the target RPM no matter what it does. The only option the turbine has is to push, or be dragged lol.  However if it suffered a generator trip where the grid connection was abruptly removed, it will immediately overspeed unless controls cut off the fuel.
In fact, this was seen in The China Syndrome - it started with a generator trip due to a grid issue. To prevent the steam turbine from overspeeding, the turbine tripped (cut off steam), so suddenly there was nowhere for 2.5 gigawatts of thermal energy to go, so the reactor SCRAMmed to stop that at the source. Jack felt a shudder and the story begins.
Answer: With car engines, the connection between car speed and engine speed is stiff, and only changed by changing gears or operating the clutch. So a car engine need to change rpm often to adapt to car speed and load (idling, accelerating, going up- or downhill). If kept on full throttle, rpm rise to a point that depends on the gear, mechanical losses, air resistance and road steepness.
On contrast, a jet engine rpm is connected to the speed of the airflow going through the engine. Even if the plane is standing on the ground, full throttle will result in a high airflow, giving a far less stiff connection between plane speed and engine rpm. The rpm on full throttle will finally depend mostly on air density and intake pressure, which changes with height and airplane speed. But engine exhaust will always be faster than airspeed.
So if full power is needed, full throttle can be applied and the resistance to the engine will not change that much while rolling, takeoff and initial climb.
In contrast, a car engine would go through it's gears, adapting its speed over and over again to match the cars road speed. Otherwise the tires would slip. This adaption is somehow made by soft air for the airplane case.
Today all those engines are computer controlled of course to keep them in safe operating conditions and give better economy.


What's smoother? Acetone treated PLA or ABS

Question: From my understanding, both PLA and ABS can be treated with acetone to make them smoother. So when they are treated with acetone, which is smother PLA or ABS or are they about the same?
When I search online, all I find is how to treat the objects.
Comment: PLA is not soluble in Acetone.
Comment: @TomvanderZanden soluble would indicate that the material dissolves in the liquid.  I've never seen any of the PLA I have dissolve in Acetone and I've not found anything online that shows it dissolving or changing the color of the Acetone.  I have found references to PLA swelling in Acetone but not dissolving.
Comment: @TomvanderZanden Most PLA filament has additives, sometimes including ABS, sometimes just dye. Often, those additives dissolve in acetone. I have never been happier with the result after trying to smooth PLA with acetone than I was before I started. Usually, it just seems to permanently soften and become porous, which is not a good look.
Comment: @tjb1 That is not quite true. I have noticed that a PLA part (which I used as a stand when smoothing ABS parts) did get noticeably smoother after a few uses. I'm not sure if that's due to the PLA being impure, but I'm not convinced PLA is entirely insoluble in acetone.
Comment: Just to clarify, you say `When I search online, all I find is how to treat the objects.` - by *objects*, do you mean the finished printed items? Do you want to smooth the printed items, or something else (i.e the filament itself)? Or are you saying that the articles that you found only describe how to *treat* the prints, but they do not *compare* the smoothness of treated PLA and ABS? I guess you mean the latter. This article [Acetone Finishing on PLA](https://ultimaker.com/en/community/10412-acetone-finishing-on-pla) has some good points raised in the comments about whether PLA can be treated
Answer: ABS filaments will smooth well with using acetone, it's been used for a while now.
For PLA filaments it's a different story, pure PLA will not smooth out in acetone and it will likely only cause structural failure of the product.
However most PLA filaments aren't pure PLA, they contain additives including ABS that react differently when exposed to acetone and the reaction will really depend on the manufacturer of the filament, only a few PLA filaments are known to smooth like ABS when in an acetone vapor bath, it is the case for ColorFabb PLA filaments and it is absolutely not the case for bq PLA filaments that only soften and break when exposed to acetone.
You'll have to make small tests with different brands of filament to see which smooth well and which don't but if you want to go fast either go with ABS or use other smoothing techniques such as sanding + 3D print Smooth On epoxy.


Why Function is not identical to `&` in autocompilation?

Question: Here is the example, copied from here
square = Function[x, x^2];
square1 = #^2 &;

the timing and unpacking status shows
data = RandomReal[{0, 10}, {10000}];

AbsoluteTiming[Developer`PackedArrayQ[Map[square, data]]]
AbsoluteTiming[Developer`PackedArrayQ[tmp1 = Map[square1, data]]]

{0.000771589, True}
{0.000748647, True}

Now we add external variable into these two definition.
a = 1
square = Function[x, x^2 + a];
square1 = #^2 + a &;

and time it again, you got
{0.0336384, False}
{0.0062035, True}

we can see & is still autocompiled, while Function is not. Why? I think the documentation treats them as identical way of writing. This distinction is oddly subtle, I just found it today. What is bad is that without Function, we can not give parameters names, thus less readability.
Comment: `square2 = With[{a = a}, Function[x, x^2 + a]]` would autocompile properly. Maybe `"InlineExternalDefinitions"` is handled differently?
Comment: `SetSystemOptions[
 "CompileOptions" -> {"CompileReportFailure" -> True,
   "InternalCompileMessages" -> True}]` can be used to switch on the generation of an error message.
Comment: It's not just about autocompilation. `square` is slower than `square1` without compilation. You can use `Trace` to see that there is a significant difference in the evaluation. Autocompilation can be switched of with `SetSystemOptions["CompileOptions" -> {"MapCompileLength" -> \[Infinity]}]` and increases the difference in your second case, while it removes the difference in your first case.
Comment: To be precise, it seems that `square = Function[x, x^2 + a];` isn't compared **in `Map`**. I think this can be considered as another evidence that the auto-compilation of pure function is still not that stable currently.
Comment: Hi, @Karsten7. I think it is might not be the point. The goal to use `Function` is to make use of autocompilation. When `&` and `Function` both been autocompiled, they are of same speed. If speed is not of concern, then I  can just use `square2[x_] := x^2;`, and in case of `"MapCompileLength" -> \[Infinity]`, `square2[x_] := x^2` is actually faster than `Function`.
Comment: @Karsten7. What difference in the evaluation do you see? For me `Trace@Map[square1, data]` and `Trace@Map[square, data]` look identical in the sense of the evaluation.
Comment: @Karsten7. good advice on using `With`, thanks!
Comment: @Karsten7. So your setting generate a message "Compilation of Function[x,x^2+a]/@Compile`AutoVar12 failed because a was not a form suitable for the compiler", What does it mean?
Comment: I wouldn't use `Timing`.  Either `AbsoluteTiming` or `RepeatedTiming`. Even if it might not make a difference here, it's unreliable on recent computer systems.  See http://mathematica.stackexchange.com/a/14159/4999
Comment: @MichaelE2. Thanks for reminding. Normally, I use `AbsoluteTiming` too. Since the code is copied, unfortunately, I didn't noticed it. I have fixed it now : )
Answer: The solution, as suggested by Karsten7, in a comment is to use With.
data = RandomReal[{0, 10}, {10000}];

a = 1;
With[{a = a}, square = Function[x, x^2 + a]];
square1 = #^2 + a &

Timing[Developer`PackedArrayQ[Map[square, data]]]
Timing[Developer`PackedArrayQ[tmp1 = Map[square1, data]]]

{0.000578, True}
{0.000528, True}
Comment: The question asks *why*, perhaps we could elucidate the underlying reason.


Trouble with windows permissions

Question: I've a folder, in which there is a file. I want user to have full control on a specific file, and should be denied every access to the other files. The first thing I did was to disable inheritance of permissions for this folder. Then I added Full Control on the specific file. Everything seems good except that the user can't save(Write) to the file, although write permissions are given. Any idea where may be the problem
Comment: If there is a specific error msg when trying to save / write suggest you include it. Suggest you include a screen snap of the file and folder permissions so we know more precisely what the config is.
Comment: The problem was that the folder was in a share, and the user didn't have permissions to do changes on the share. Thanks for trying to help.
Answer: Are your users accessing the file via a share? What are the share permissions set to? Your users will need at least the Modify share permission in order to write to the file.
One thing you can try as well is to use the Effective Access tab in the advanced security options of the file. It will tell you exactly what file permission the users have (but not share permissions).

Trouble with windows permissions


How to fix a C1010 error without turning off precompiled headers?

Question: So,
I have to use precompiled headers in my VS 2005 project.  Now I have a shared source file that does not have a #include "stdafx.h"... How can I include the shared source file in my project without adding stdafx.h to the top of the source file and without turning off precompiled headers??
Answer: File properties -> C/C++ -> Precompiled Headers -> Create/Use precompiled headers -> Not using ...
Comment: oh snap.  I figured it was something simple like that and I'm just being noob.  Thanks... I'm still getting familiar with VS :)
Comment: This turns off PCH, which is exactly what the OP wants to avoid... Use /FI, instead.
Comment: This option allows you to turns off pch for this file - which probably is exactly what the op wants. Where did you get your interpretation of the op wanting to use precompiled headers for the source file from?
Answer: Look in the properties (context menu) for that file, in the C/C++ - Precompiled Header section.
Change "Create/Use Precompiled Header" to "Not Using Precompiled Headers".
Note - I just checked this in VC++2003 - the option might have moved in VC++2005 or 2008, but I doubt it. Even if it has moved, though, it shouldn't be hard to find.
Comment: @Xavier - It turns off PCH for *ONE* *SPECIFIC* cpp file. This is rarely a big deal, and can be beneficial. If every header for the project is included by a single stdafx.h header, which is included by every cpp file (as VC++ encourages), *any* change to *any* header causes *every* cpp file in the whole project to need rebuilding. Of course that suggests explicitly selecting different precompiled header files for different cpp files - but the options are pretty obvious, on the same page as the "Not Using..." option, so why state the obvious - esp as it's not always worth the hassle.
Comment: Yeah I wasn't sure if this was specific to MFC...  I've never used pre-compiled headers before.  Thanks!
Comment: This turns off PCH... Use /FI, instead.
Answer: You could also use the 'Force Include' option: "This option has the same effect as specifying the file with double quotation marks in an #include directive on the first line of every source file specified on the command line, in the CL environment variable, or in a command file."
Very handy to introduce PreCompiled Headers without changing all the source files...


Can "hometown" refer to a place where one did not necessarily grow up, but that feels like home?

Question: Say I was raised in the Philadelphia area. By the traditional reasoning, my "hometown" would be the name of my Philly suburb. But what if that suburb doesn't feel like home anymore? I'm looking to see if the word "hometown" can encompass the feeling of stepping off the plane and feeling like you're home again. So can the term refer to a place where one didn't necessarily grow up, but that feels like home? What if the person in question doesn't even live in this place?
Comment: This is an interesting and nuanced question. 'Hometown', outside of figurative uses, is a more concrete term than 'home'. 'Home', on the other hand, has so often been used in figurative senses that it's use in constructions without an article or possessive is lexically associated with "feelings of belonging, comfort, etc.", or even as a primary definition, "refuge, a sanctuary; a place or region to which one naturally belongs or where one feels at ease". Thus 'hometown', borrowing from the 'home' component, is well-suited to such figurative use.
Answer: Yes, hometown may refer to a place different from the one you grew up in:
hometown:

the town or city that a person is from, especially the one in which they were born and lived while they were young:

He was born in Miami, but he considers New York his hometown since he's lived there most of his life.

(Cambridge Dictionary)
hometown:

the town or city in which a person lives or was born, or from which a person comes.

(Dictionary.com)
Answer: You cannot change your hometown.  Your hometown is not just a location – it includes the time period in which you lived there.  It includes the sights, sounds, smells, tastes; it includes the feeling of the place against your skin.  It includes the changes that flowed through the place when you were there. It includes the people, the river, the buildings, the tree you climbed or the tundra you walked on, the scales of the fish you caught, the way a dog's hair felt against your cheek, the taste of the weeds you put in your mouth, the smell of your first grade teacher, the snot that dripped from your nose, the mystery you felt in everyhing.  It includes the books you read, the conversations you heard, the way your foot slipped in the mud, the voice of the guy across the street as he yelled "If you do that again, I'll skin your alive".  Trying to say someplace else is your hometown is denying part of your true self.


How to generate correlated nominal variables?

Question: I have 15 nominal variables (unordered), and all of them have more than 2 categories. I used Cramer's V to get a correlation matrix. Now I want to create correlated nominal variables by the marginal distributions and correlation matrix. Most answers I viewed are based on Pearson correlation, or using copula method assuming normal or other distributions. But Pearson coefficient can't be used here since all the variables are nominal, and I don't think I could use the normal distribution assumption. Is there a more general solution?
Comment: This qiestion: http://stats.stackexchange.com/q/128899/3277 asks about specifically ordinal variables while you  ask about nominal. However, you might find it relevant as well.
Comment: One possible idea is to use iterative proportional fitting - the algorithm that is used in the form of multivariate re-weighting of categorical data called rim or raking weighting as well as in loglinear analysis. In the rim weighting, we train magrinal frequencies iteratively towards the wanted ones. Now, the (raw) present idea is to train the marginal frequencies towards target bivariate association (such as Cramer or chi-sq) instead. I haven't tried/done it myself, though. So I'm not sure.
Answer: I don't know how you would use Cramer's $V$ to do this.  I assume there is some fancy way to generate such data, but I don't know it.  What I can do is give you a simple fall-back method.
If you can stipulate the joint probability of every combination of levels of your categorical variables (i.e., the probability an observation will fall into the combination of level $i$ of variable 1, level $j$ of variable 2, level $k$ of variable 3, etc., for all levels of all variables), you can simply draw random variates from a standard uniform and compare that value to the ordered set of probabilities to determine which cell it should be in.  Note that if you want to individually create these by hand, it could take you a while: e.g., with fifteen variables with three levels each, that's $3^{15} = 14,\!348,\!907$ individual probabilities that would need to be specified!  If you have a dataset whose proportions you want to serve as a template for the probabilities, you can write simple code to do this for you.  Either way, that does amount to having specified the correlational structure of the population exactly.
To demonstrate this, consider a simpler situation with just two categorical variables with three levels each.  Here I create a simple simulation (coded in R):
<code>##### Here are the joint probabilities I want to use:
#    y
# x      A    B    C
#   a 0.13 0.18 0.11
#   b 0.02 0.11 0.11
#   c 0.18 0.05 0.11
##### here they are in a single row vector:
probs     = c(0.13, 0.18, 0.11, 0.02, 0.11, 0.11, 0.18, 0.05, 0.11)
cum.probs = c(0, cumsum(probs))  # notice I put a 0 at the beginning
cum.probs
# [1] 0.00 0.13 0.31 0.42 0.44 0.55 0.66 0.84 0.89 1.00

set.seed(8982)                # this makes the example exactly reproducible
vals = runif(500)             # generate 500 random values / probabilities
##### cut the random uniform values into cell categories:
cats = cut(vals, breaks=cum.probs,
           labels=c("aA","aB","aC","bA","bB","bC", "cA", "cB", "cC"))
low  = substr(cats, start=1, stop=1)  # extract the 1st letter
up   = substr(cats, start=2, stop=2)  # extract the 2nd letter
##### these are the observed counts:
table(low, up)
#    up
# low  A  B  C
#   a 68 98 54
#   b  7 47 67
#   c 77 25 57
##### this is a reasonable match to the population pattern specified:
prop.table(table(low, up))
#    up
# low     A     B     C
#   a 0.136 0.196 0.108
#   b 0.014 0.094 0.134
#   c 0.154 0.050 0.114
</code>
Now, what if you had data, and you wanted to use those proportions instead of specifying 14+ million combinations by hand?  Then you just get the proportions from your dataset and put them into a single vector.  For example, like so:
<code>props = as.vector(t(prop.table(table(low, up))))
props
# [1] 0.136 0.196 0.108 0.014 0.094 0.134 0.154 0.050 0.114
</code>
Comment: The answer is awesome, thanks. But my actual case is..there are 25 variables and 611,529,523,200 cells to specify...which exceeds R's maximum vector length 2^31-1...I am thinking maybe I could cut variables into several parts and then try your method separately...
Comment: Presumably, @qianw. I bet there is also an existing R method for that kind of problem.  You could ask about that as a pure programming question on [SO], if you wanted.


Why didn't Abraham try to persuade Sodom people to repent and regret for their sins?

Question: It is known that Abraham was strong spiritually and physically. He won the war of the four kings. He was afraid of nothing but G-d. It is also known that Abraham tried to ask for mercy and tried to convince G-d not to destroy Sodom. Why didn't Abraham try to convince Sodom people to repent and regret for what they did. There could have been even a minor chance that the people change their behavior and Sodom could have been saved. Only after failing to convince them he could ask G-d for mercy? In addition, why didn't he ask G-d to give him chance to try to convince them to regret?
Comment: למה אברהם לא החזיר בתשובה את אנשי סדום? https://qarov.org/%D7%9C%D7%9E%D7%94-%D7%90%D7%91%D7%A8%D7%94%D7%9D-%D7%9C%D7%90-%D7%94%D7%97%D7%96%D7%99%D7%A8-%D7%91%D7%AA%D7%A9%D7%95%D7%91%D7%94-%D7%90%D7%AA-%D7%90%D7%A0%D7%A9%D7%99-%D7%A1%D7%93%D7%95%D7%9D
Comment: WOW, an interesting question! You might open a Pandora box here, comparing different leaders' behaviors - why Noah didn't ask, why Abraham and Moses didn't ask, etc. And why Yonah was asked to do the opposite.
Comment: IMHO, I see two contradicting approaches in Jewish tradition: 1. we're the light to the nations and we're obligated to educate them (convert?) 2. we don't care about nations, we care about ourselves and our seclusion from the nations. Abraham's narrative is somewhere in the middle - he askes to withdraw the decree, but if God doesn't, Avraham doesn't care.
Answer: He did try.
It writes in the Midrash Aggadas Bereishis 25 here that Avraham specifically set up camp opposite Sodom and its surrounding cities so that he could receive those that passed by as Sodom and Amorah did not allow guests to enter the city.
Comment: Where does that source indicate that Avraham tried to convince people of Sodom to repent? It merely mentions that by default, he cornered the hospitality market in the region.
Comment: He set up on the outskirts in order to receive people as they passed by - Avraham was the first kiruv professional do you think he just let them come, eat and go? That's why the text continues and says that Avraham reasoned, now that the city was overturned why should he stay
Comment: The OP asked if Avraham tried to convince people of Sodom to repent. Granted, that Avraham likely tried to be "mekarev" the wayfarers, who were unwelcome to lodge in Sodom. However there is no indication that he had any access or interaction, with the residents of Sodom, per se.
Comment: Why then did he specifically set up camp there then?
Comment: It seems that Sodom was a popular place, which is precisely why the Sodomites outlawed hospitality to non-residents; in order to make immigration virtually impossible. Avraham realized that there was an opportunity to corner the hospitality market in the region, since he would be the sole hospitality provider in the area. Moreover his services were needed there the most, since unlike other places, in Sodom, there were absolutely no other options available to a wayfarer. However there is no indication in the Midrash, that Avraham was targeting the residents of Sodom, for "kiruv" purposes.


NodeJS not found after installing

Question: I have this program which needs nodejs to work. So when I install nodejs and test it out, it doesn't work. This is exactly what I did:
    multiplemark@multiplemark-OptiPlex-GX280:~$ sudo -s
    [sudo] password for multiplemark:
    root@multiplemark-OptiPlex-GX280:~# apt-get install nodejs && npm
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    The following packages were automatically installed and are no longer required:
      libmaven-clean-plugin-java libplexus-compiler-manager-java
      libmaven-filtering-java libmaven-shared-io-java libax25
      libmaven-jar-plugin-java libmaven-install-plugin-java
      libplexus-compiler-api-java libmaven-file-management-java
      libplexus-compiler-java libmaven-archiver-java
      libmaven-resources-plugin-java libc-ares-dev node-node-uuid libssl-dev
      libssl-doc libmaven-dependency-tree-java openbsd-inetd zlib1g-dev
      libplexus-compiler-javac-java libv8-dev libmaven-shade-plugin-java libev-dev
      libplexus-digest-java libmaven-compiler-plugin-java
    Use 'apt-get autoremove' to remove them.
    The following NEW packages will be installed:
      nodejs
    0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
    Need to get 0 B/680 kB of archives.
    After this operation, 2,473 kB of additional disk space will be used.
    Selecting previously unselected package nodejs.
    (Reading database ... 186254 files and directories currently installed.)
    Unpacking nodejs (from .../nodejs_0.6.12~dfsg1-1ubuntu1_i386.deb) ...
    Processing triggers for doc-base ...
    Processing 1 added doc-base file...
    Processing triggers for man-db ...
    Setting up nodejs (0.6.12~dfsg1-1ubuntu1) ...
    update-alternatives: using /usr/bin/node to provide /usr/bin/js (js) in auto mode.

    root@multiplemark-OptiPlex-GX280:~# nodejs
    No command 'nodejs' found, did you mean:
     Command 'nodefs' from package 'noweb' (main)
    nodejs: command not found
    root@multiplemark-OptiPlex-GX280:~#

Comment: See http://stackoverflow.com/questions/18130164/nodejs-vs-node-on-ubuntu-12-04
Answer: The correct command to launch nodejs is node

NodeJS not found after installing


why is the signal divided into epochs in EEG classification?

Question: I'm new in EEG signal classification.
Studying the literature on this topic, I wonder why the EEG signals are divided in epochs, so, instead of classifying the whole signal all at once, we usually classify "windows" of signal, splitting the original one. I searched in the literature for a possible explanation, but I find nothing which answers to my question.
Answer: Basically, to perform a spectral analysis. Take a look to this: http://support.ircam.fr/docs/AudioSculpt/3.0/co/Window%20Size.html
I do not know if you refer to some specific approach, but usually, the main EEG classification approaches use frequency analysis (also combined with temporal analysis) to extract the features that will be used to train the classifier or infer the prediction.
Cheers
Comment: If you do a temporal analysis, I guess you can use the whole signal depending on your signal processing techniques.
Comment: ok, but if I decide to do only temporal analysis (so no window is needed)? Why in the literature the epochs are still used?
Answer:
Compute-expense: recordings may be tens if not hundreds of thousands of samples long with multiple channels. One either runs out of memory, or heavily downsamples at layer 1, which loses too much information before the NN can do much with it.
Data augmentation: for e.g. classification, if you have a 10 minute segment belonging to same class, splitting it in two gives you twice as many training samples
Feature localization: small kernel length convolutions are generally preferred, which may better extract time-localized information than global - unless one explicitly increases receptive field with more layers and strided convolutions (like in WaveNet).
Stability with networks that suffer gradient problems for very long sequences, like RNNs. More info doesn't help if a net can't learn from it (see e.g. here).

There's nothing that says we must divide up a signal, however; depending on compute-resources, amount of available data, and architecture design, feeding all at once can outdo divisions (since presumably the network is exposed to more relevant information at once).


Windows 8 hybrid shutdown disables BIOS setup

Question: My Lenovo laptop runs Windows 8 and Linux Mint with GRUB bootloader.
Today, I have deleted Mint partition from Windows and by mistake shut down my laptop instead of rebooting it.
Now I cannot change my boot priority to load from dvd.
Is there any way to unlock BIOS, and boot into any OS?
Answer: Hybrid Boot is basically a Logoff + Hibernation. In Hibernation the access to BIOS is disabled to avoid resume issues. Start the Windows 8 again and select reboot or press Shift and press the shutdown button in the Charms to do a full shutdown.
Answer: I accidentally found the solution when I ejected the battery preparing to disassemble the laptop.
It somehow reseted this shutdown thing.
Then I just booted from disc and restored the MBR.