Display one decimal point after a whole number after divided by 10

Question: I have a slider-controlled source text which I try to sync with the corresponding graph bar. What I need is, to display one decimal point after the value of the slider is divided by 10. That is, if the slider's value is 80, I want to display the value, 8.0 on the source text. Of course I need the zero, after the 8, which is a whole number.
Answer: For recent versions of AE (AE 2019+)
you can use the javascript Intl.NumberFormat object, which does all the formatting for you without any tedious string munging and regex and all that carry-on.
var sliderVal = thisComp.layer("controller).effect("206")("Slider");
Intl.NumberFormat('en-AU', {minimumFractionDigits: 1, maximumFractionDigits: 1}).format(sliderVal/10)

the en-EN part is the locale string, and is your preferred locale, in other words, your culturally specific way of displaying numbers (en-AU is for Australia, and uses . for the decimal separator and , for the thousands separator). This makes it super easy to format, because it handles things like thousands separators, currency symbols and even what characters you want. You want it in Chinese decimals? Sure use 'zh-Hans-CN-u-nu-hanidec' and it will look like
一,六二九.二
The second parameter is the options, and here we get to specify things like minimumFractionDigits and maximumFractionDigits. You can also zero-pad the number with minimumIntegerDigits, so a zero-padded number with 5 digits and one decimal place would be specified thus:
Intl.NumberFormat('en-AU', {minimumIntegerDigits: 5, minimumFractionDigits: 1, maximumFractionDigits: 1}).format(theNumberToFormat);

Read the docs here
It's worth noting that the usual suspect for number formatting someNumber.toLocaleString(), which is much simpler, doesn't work for what you want. For some reason in AE's implementation of JS it always returns two digits and adding maximumFractionDigits as an option doesn't work.
For earlier versions of AE
Here's how to get the 1 decimal place after the number:
var n = Math.round(theNumberToFormat *10)/10;
(n % 1 === 0)? '' + n + ".0": n

The first line rounds off any digits after the first decimal, the second is for when the number is an integer (when n % 1 is 0, % being the modulus operator which returns the remainder of the first number divided by the second), which would normally display with no decimal. If it is, it treats the resulting number as a string and adds '.0' to the end of it. If you want thousands separators you need to do some further trickery, that's a common JS question on SO, e.g. here.
var n = Math.round(theNumberToFormat *10)/10;
n = (n % 1 === 0)? '' + n + ".0": n
n.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");

The last line is fancy regex voodo, I don't know exactly how it works, it's got something to do with lookaheads and whatnot. But it works.
Comment: I'm using Ae 2015 version
Comment: Have you tried it? There were a lot of undocumented goodies in earlier versions, you never know…
Comment: Sorry I'm very new to slider expressions, could you please tell me, that how I use that second line with that thisComp.layer things?
Comment: Ps. Ah I got the result...!! thank you dude!!
Comment: Replace theNumberToFormat with the number you want to format. So if you use the first line of the other expression, it would be n
Comment: PS, don't thank me, mash that tick button. It helps others find the answer too
Comment: Done, and thank you agian :-p


Can I use lethal force to protect myself and others from an on duty officer if he or she starts shooting up the location?

Question: I know that in Colorado we have the castle law for self defense which allows people to protect themselves with lethal force on or inside their property as long as they believe their life and family are in immediate danger. I'm not too keen on other States, but hypothetically, and god forbid, lets say a cop on duty and in uniform decides to commit a mass shooting at a public place. As an innocent bystander who sees no indication of lawful discharge, and witnesses others who did nothing wrong getting shot, if that bystander is armed and afraid of being the next person who gets shot. Could he or she use lethal force to stop the threat without facing legal consequences?
Comment: Off topic, but I think by "keen on" you mean "knowledgable about", but it means interested in or liking it.  https://www.macmillandictionary.com/us/dictionary/american/keen-on-something
Comment: Several years ago, there was [another discussion here](https://law.stackexchange.com/questions/11865/am-i-legally-able-to-use-lethal-force-against-a-police-officer-in-defense-of-ano) about a similar hypothetical scenario.
Answer: The answer provided by Dale M is half right, but there are a few things that I think are wrong.
Firstly, the actual reality of the situation doesn't matter. What matters is that you act in a reasonable manner, performing assessments of the situation as a reasonable person would do.
If you misread the situation, and end up killing a police officer that was acting in a lawful manner, it doesn't necessarily mean you were acting unlawfully yourself.
Because police officers are generally exposed to situations where they would be forced to use their firearm, that obviously would impact how a reasonable person would see the situation, but the test for reasonableness would not go out the window.
In addition, even if you were found to not be acting in a reasonable manner, there is certainly a question if you would be found guilty of a lesser charge of manslaughter rather than murder. It's possible the self-defence claim would be upheld as an imperfect defence.
Comment: So if a would-be mass-shooter acquired a passable fake police uniform, this could be a real problem.  (Doesn't even need to be *that* passable as few people are likely to get close enough to examine it in detail once the shooting starts.)
Comment: @DarrelHoffman like Breivik did. Started shooting, caused panic, went to one harbor leading off the island in passable police uniform, shot everyone who came near him.
Comment: @DarrelHoffman This happened in Nova Scotia almost exactly 2 years ago, except they also had a replica police car.  Also the police response was pretty bad. https://en.m.wikipedia.org/wiki/2020_Nova_Scotia_attacks
Comment: @LorenPechtel it is a moment (or several minutes) of hesitation and confusion that they are counting on. Fake cop is not usually on top of the list people think in any given situation.
Comment: @jo1storm Yeah, it would cause hesitation.  Someone being shot at is not likely to recognize the issue.  I'm seeing the question as someone a bit back that's observing the scene.  "Cop" behaving in an extremely uncoplike fashion = probably a fake cop.
Comment: @jo1storm And if I saw a "cop" apparently engaging in a mass shooting that's what I would think--fake cop.
Answer: Self defense is self defense
It doesn't matter whom you are defending yourself (or others) from.
However, a police officer is allowed to use force in wider circumstances than anyone else. If you misread the situation and the officer was acting lawfully then what you did was murder, not self defense.
Comment: Meh, a jury will understand the concept of "the fog of war".  So it's not as clean-cut as "officer acted lawfully, therefore your action is murder". Happens all the time where neither party is found to be guilty of anything, you usually hear about it when police shoot minorities who, in hindsight, were innocent.
Comment: Self-defense is a subjective, not objective standard. A person having a good-faith, reasonable belief that their life is in danger is allowed to act in self-defense, even if the other person is acting lawfully.
Comment: How could whether something is reasonable or not possibly be objective?
Comment: @JakeRobb Subjective means "Was it reasonable for the defendant to think what they thought, given the mental state, history, etc". In other words: "Do we believe the defendant would have had this belief?". Objective means "Generally speaking, across society, would a reasonable person have this belief."
Comment: Is this one of those cases where the legal system has its own definitions for words which are in conflict with the dictionary definition? By the dictionary definition, both scenarios you gave are unquestionably subjective.
Comment: @JakeRobb It's a little in conflict. Subjective means "according to subject". Objective means "according to known facts". We view the "known facts" through the lens of how a reasonable person would act because it's unfair to hold them to a higher standard that a reasonable person. A jury has the time to sit down, think about all the known facts, assess all possible courses of action, and carefully determine the best course of action. A reasonable person may not take the "best" course of action because they don't get to take a fully scientific approach at the time.
Comment: Okay, and is there an objective definition of "reasonable person"? Without one, nothing that stems from it can be objective.
Comment: @Acccumulation No. The "reasonable" proviso (which you appear aware of) is added by courts explicitly to make the standard objective.
Answer: Self defense doesn't depend upon who you are defending yourself against, it's your state of mind and the facts known at the time, not an after action evaluation with 20-20 hindsight.
Absent shape shifting space-aliens, if you see someone walking around in the premmie icu shooting babies, killing the shooter is going to be self defense no matter what uniform the shooter is wearing or what badges they may be carrying.
More realistic scenarios will be considered on a case by case basis, with a great deal of bias on the side of "reasonable people don't see police officers as mass shooters". Your scenario might be sufficient to keep you from getting into trouble IF the uniformed person was in fact a mass shooter. But no guarantee. If you are on tape dancing around and singing "I shot the sheriff", the fact that the person was not a police officer and was in fact a mass shooter may be insufficient to keep you out of jail. If the shots by the uniformed officer were in fact justified, your ignorance is not going to help you too much. You'll need something better than "I saw a cop shooting people so of course I thought he was a bad guy".
Comment: Self-defense is not *supposed* to depend upon the nature of one's attackers.  On the other hand, people who defend themselves against law-enforcement personnel who are acting in grossly reckless fashion often face extreme uphill legal battles, *even in cases where the law-enforcement personnel deliberately acted to prevent the defendant from being aware that they were cops*.
Comment: @supercat I half-remember one such case where police or prosecutor said, "They were not in uniform, but dressed in such a way that one should know they were police."  I would love to have that clarified!
Comment: @supercat: even facing the legal battle is wrong, but the prosecutor and cops are too tightly entwined in reality for that not to be a potential risk.  There's no such thing as internal affairs for prosecutors, so strategic and outright malicious prosecution is basically almost risk free. In most cases the worst they would face would be losing their job, and that would be something for which there was no political support.
Answer: In pretty much all circumstances (outside your home, if you are in a Castle Doctrine state), before you ask yourself "should I shoot that person?", you should first ask yourself "can I get to safety by removing myself from this situation?"
If the answer to the second question is yes, then I have a hard time imagining that you would succeed in your self-defense argument.
EDIT:  My intent is to offer a perspective that might be shared by members of your hypothetical jury or others. If this is not how Law.SE should be used, please say so, and I'll be on my way.
Otherwise, allow me to elaborate:
Shooting someone should be a last resort. If you have an option that involves no death, take it. If you believe that an on-duty, uniformed police officer is acting unlawfully in the manner described, I would recommend that you:

Seek shelter

Contact authorities

In this case, I would recommend authorities of a different but overlapping jurisdiction. For example, if it's a city police officer, call the county or the state. You don't want the authorities who show up to be buddies with the shooter.

You said:

As an innocent bystander who sees no indication of lawful discharge, and witnesses others who did nothing wrong getting shot

Just because you see no indication of lawfulness does not mean the act is not lawful. Just because you didn't see the victims doing something wrong does not mean they haven't. You are taking your assumptions and betting an awful lot on them.
Your original question was:

Could he or she use lethal force to stop the threat without facing legal consequences?

Without consequences? I can't imagine.
If you shoot a uniformed police officer, justified or otherwise, you had better count on being arrested. If you're lucky, your story gets corroborated, the charges dropped before trial, and you walk. But none of that matters: you now have an arrest on your record, and that will carry legal consequences for the rest of your life.
Comment: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).
Comment: This answer ignores the fact that in all U.S. jurisdictions it is lawful to use lethal force to protect *others* from imminent grave danger.
Comment: @feetwet also that (unless wikipedia is lying to me) the majority of U.S. jurisdictions have so-called "stand your ground" laws that abolish the duty to retreat anyway. (Colorado specifically doesn't have a statute law for that, but apparently does have case law/precedent.)
Comment: @JakeRobb we conspicuously try to avoid giving "advice" on Law.SE.  Presently this post consists of advice (first paragraph) and then speculation (second paragraph), with no discernable legal information.  As such it arguably doesn't qualify as an answer on this Stack Exchange.
Comment: @JakeRobb Remember: Stack Exchange isn't a forum for conversations.  (I'd invite you to take the tour, but I can see that you already have, and that you have been around SE's for a while.)
Comment: @JakeRobb At least in Colorado, the self defence law does not appear to exclude shooting police officers.
Comment: @feetwet, I believe that's not true if said danger is in the form of a police officer acting lawfully. While the question is phrased to lead us to believe that the officer is NOT acting lawfully, I believe it would be wise not to wager a life sentence on that belief if you have other options.
Comment: @feetwet, point taken. I'm not sure how to rephrase my first paragraph to be less advice-y, but my intent was to provide a thought technology for use when wondering whether a self defense argument to murder would hold water. I've also extended my answer significantly. It still contains no discernible legal information, but I believe that it adds value to the conversation.
Answer: An approach to identifying if they were commiting a crime would first need to be established.
How do you know he is 'shooting up the place' and not performing his duties against a gang or alternative bad scenario?
Are they just 'executing' citizens for no apparent reason of course you can use lethal force to prevent the loss of life. Police officers are exactly that. Officers, they are humans who are subject to the law themselves. When they are 'on duty' their personal agenda's are not to be involved in their conduct. If it is then they are no longer a Police officer, just a criminal wearing a costume in the eyes of the law.


Can't get Denim on Lumia 1520

Question: I got a Lumia 1520 from Hong Kong. However, I live in Hungary (maybe that's the problem?)
I should be able to update my phone to Denim, but it doesn't give me the option to update my phone.
Any suggestions?
Comment: What do you mean "it doesn't give you the option to update your phone"? As in it checks for updates, but finds nothing?
Comment: It says my phone is up to date but I should be able to see the denim update according to the MS availablity page
Answer: Please note that I'm posting this answer assuming that your ambiguous statement "it doesn't give me the option to update" means that you go to Settings->Phone Update and every time you check it tells you that your phone is up to date.
First go to this website and see if the update is available for your phone country variant. If it's not, the only things you can do are: wait or flash your phone with different (country variant) firmware. If it is available, read the rest of my answer.
No, the fact where you live or what regional settings you have set should not matter.
If you have enabled the "Preview for Developers" then this is your problem. I've read somewhere that when you enable the PfD program, your phone looks for updates on different servers which do not have the Denim update. You have to go to the "Preview for Developers" app and disable it (you can re-enable it after the update). Then of course go to Settings->Phone Update and use the "Check for updates" button. This has solved my problem.
If both you don't have the PfD and the the website says the update is available for your phone, possibly the only other things you can try are to:

Restore the phone to factory settings (Settings->About and click "Reset your phone" - obvoiusly this will remove everything from the phone).

or if that doesn't work:

Use the official Windows Phone Software Recovery Tool and reinstall your OS (this will also remove everything from your phone).

If this doesn't work I don't know what else will.
Comment: First of all ofc  it says my phone is up to date so I cant update it.
The phone should be available to update denim as the microsoft availablity says (its available for Hong KOng users)
I was not in the PfD (now I joind in, try if it works but still no update for me) and I have tried restoring it with the recovery tool.
How can I update/change my firmware manually? :O
Comment: I most certainly didn't have to disable PFD.
Comment: @Shawn There must be some other dependence. I absolutely had to switch it off temporarily (and it's not just me) and it worked right away.
Comment: @PappDániel I can't really walk you through the process of flashing the phone manually but when I did this with my Lumia 920 over a year ago I had find the firmware and download it and then flash it with software called "Nokia Care Suite". There are some tutorials on the web that make it easy. Usually when you find a website with a firmware to download there are some instructions on how to flash it as well. Fortunately Lumia phones are not as easy to brick as some other brands.

Can't get Denim on Lumia 1520


Upload entire HTML project directory to EE2 possible?

Question: Required to use ExpressionEngine 2.7.3 due to Hudson module (No API either).
We built our site locally in HTML/CSS/JS since that's what we're used to and before we start copying it over we wanted to check if there's a easier way or if it's possible to just upload our current directory to EE?
Answer: You can use all your existing site HTML/CSS/JS to setup templates. Though it's not as simple as just "uploading our current directory to EE." Do you have more specific questions? This is a bit vague to provide a concise answer.


Why won't my RPi 2 won't connect to wifi?

Question: I am using a raspberry Pi 2 with a Realtek wifi dongle using 8188eufw firmware downloaded from here
I have run lsusb and it registered my dongle. The problem is that when I plug the dongle in it disconnects my other usb devices such as my mouse and keyboard. I think this may be a power issue?
Is it or do I have some other issue?
Also I have an issue connecting to the Internet when it doesn't disconnect my mouse and keyboard. It doesn't connect to the Internet possibly because the normal wpa app that comes with raspian wasn't there. I used the network configuration tool in the toolbar but didn't know whether the 'Ip address' it asked for was external or something else. Pls help I'm desperate. Nothing seems to fix it and I've looked through everything.
Comment: This could be power related (especially since you lose the keyboard and mouse). First step to diagnosing this would be to connect the WiFi dongle to the Pi using a powered hub. As for the IP question can you edit your question and include a screenshot.
Comment: How do you have any suggestions for a hub I co use?
Comment: this should help you pick a hub http://elinux.org/RPi_Powered_USB_Hubs
Answer: This is definitely power related. Have you modified the setting in the boot config that gives the USB ports more power? If not then make sure that that's on. I believe the file is /boot/config. It must be something like that. The setting is something like max_USB_current.
Comment: Thanks I think that this might work but will it effect the performance of the Pi? I'm powering from a TV port.
Comment: Everything should be just fine, since you power down correctly.
Comment: max_usb_current is not listed in /boot/config.txt and other sites say it should be. Do I add it in?
Comment: Yes, you should.


Best neural network architecture for object detection without location

Question: I want to build a model which is able to detect the presence of a specific object in the image without caring about the location (i.e. no bounding boxes, just 0/1 output). More specifically, the object is always the same and it is characterized by a specific pattern (e.g. a national flag or a bar code). The algorithm should be robust to scale, rotation and distortion.
What is the best architecture in this case? Is there something better than a generic CNN binary classifier?
Answer: It mostly depends on the amount of data you have available for training.
However, unless you have an extremely limited dataset and you are unable to generate synthetic data, CNNs are currently the best approach for solving your task.  With sufficient data, they are very robust.  To improve their performance, you can augment your dataset by randomly rotating, flipping, brightening, contrasting, scaling, cropping, blurring, and adding noise to the images throughout training.
It also depends on your speed requirements and computational resources.  Traditional methods have the potential to be quite fast, but if you only care about accuracy, a deep network would probably perform better.  Note that some CNNs are also quite fast, such as MobileNets.
There are a few reasons you might go "old school" and use template matching and more traditional approaches as suggested by @TheDjentleman:

You do not have enough data to make a CNN robust AND you cannot generate synthetic data
CNNs do not meet your speed requirements AND the traditional methods do
You do not have sufficient resources to train a deep network, such as GPU(s).  FYI Google developed a cloud computing tool for researchers and developers at a pretty reasonable cost.

If none of those criteria fit your situation, go with a CNN.
Lastly, you do not necessarily need a generic binary classification CNN.  You can use an object detection network or even a semantic segmentation network and just ignore the location data if you do not need it.
Answer: May not really answer you question, but to be honest, if you just want to find one specific object that you know beforehand, I wouldn't use a neural network at all (in my opinion you should use the right tool for a task).
For easier tasks like this, you can use more "old school" methods (boo) like template matching. With such approaches you just take an isolated image of your object and, for example, extract a set of features (e.g. using opencv) and then move a rectangle over images where you want to find that object and just compare features. The advantage of such approaches is that you do not really need training data, like you would for training a neural network.
If you really, really, really want to use a CNN, you could try to just paste an image of your object into thousands of random images and then take even more images to train a classifier that examines if the object is in the image or not.
Comment: Thanks for your answer but I guess template matching is not able to generalize. :)
Comment: I know, but if you just want to recognize one specific object, you don't really have to generalize too much. I agree, that it is a different story if you want your classifier to tell you if there is an object of a specific class (e.g. an apple) in your image
Comment: I forgot to mention that I am looking for a method which is invariant to scale, distortion and rotation. Can I achieve this with template matching?
Comment: I am not too much into this area any more, but I think you can make it invariant to scale and rotation (at least to some degree, at least he did it: https://www.youtube.com/watch?v=1M_JIfPRLao) by building image pyramids and using several templates of the same object. about the distortion, I can't really say anything about that, sorry
Comment: @TheDjentleman I didn't understand your task very well but search for spatial transformers.


Why doing transparent proxy is a bad idea?

Question: I wonder why Tor Browser, Tails or Whonix are the most preferred ways of browsing Tor. What's wrong with manually doing a transparent proxy and routing all traffic over Tor through iptables? Why do it is a bad idea? Assuming, manually routing all traffic through Tor is done by a person who's familiar with Linux, networking, etc. then is doing it still a bad idea?
Comment: Actually it is not as bad idea as you've told. But it may cause privacy issues. For example a script may send your real IP to a server using TOR. The server will see the TOR's exit node IP address while the script leaks your real IP. These kind of privacy issues are tried to be solved in Tor Browser, Tails or Whonix.
Answer: usually yes...

first the easiest one, because of error-proneness:
i'm pretty sure the configuration (and code) of the mentioned projects is reviewed much more often than the configuration of someones single setup.
and its not just about how accessing the network, it is also about the clients and their configuration:
--> the idea is to be not just anonymous (by hiding the IP), but also not traceable/pseudonymous (by vanishing in the masses of homogenous users)...
hence blocking some IPs more or less than the usual Tor user, one not so wide spread addon installed and/or a pretty special resolution of your browser window and you are pretty easily trackable.

e.g. hardening the browser is a huge task! and also the devs of the mentioned projects are also working hard to make the fingerprint of their users look even.


Installing .apk as system app directly (with root)

Question: I'm wondering is it possible to install .apk file as system app directly (with root)? Without converting user app to system app.
Answer: You can simply copy the apk (its name not relevant) into /system/app or /system/priv-app, set the appropriate permissions (rw-r-r, root:root) and then do a reboot. That's it.
Works well on Android 6.0.1.
Comment: Use a file manager app such as Solid Explorer to copy the Apk to the location and to set permissions. If the app is already installed move (not copy) its apk from /data/app directory to the location I mentioned in the answer. A reboot would fix things on its own. @androiddeveloper
Comment: I've now tried the "/system/app mover" app on Nexus 5 with Android 9 (custom rom of course) and BusyBox which it requires for some reason, and it converted an app to be a system app without any issues. Tried again on my Pixel 2 with Android Q, and it still showed an error that it can't do this "could not mount /system" .  Odd
Comment: Can you delete the apk from /system/app folder after reboot, once it's installed?
Comment: The presence of an APK is necessary for the app to be functional, otherwise, after removal, the app won't run, although you would continue to have the app icon in your launcher until you reboot the device.
Comment: How exactly do you "simply copy the apk" ? And what if the app is already installed?
Comment: Solid explorer wrote that it can't copy/move the folder of the APK file. Also tried to do it for the file. It failed. Also tried to either /system/app or /system/priv-app . Tested on rooted Pixel 2 with Q beta 5. Reboot also didn't help, of course.
Comment: @androiddeveloper when I wrote this answer I tested it on a stable release of Nougat, so I suggest you ask a new question for your issue.
Comment: @Firelord Maybe things changed since N ?
Comment: I also have the problem of the mounting the system partition as rw, but still was unable to. Android 10 is having something called overlay filesystem to do something like this, but still not succeeded on it.
Answer: Via ADB: (Copy apk to phone via usb/My computer first)
Example:
<code>adb shell                                           (Get into shell to run beow commands)
su                                                  (Run as root)
mount -o rw,remount /system                         (Mount system read/write since default it read-only)
chmod 755 /system/priv-app/Messaging_SEP81          (Set permissions on folder)
chmod -R 644 /system/priv-app/Messaging_SEP81       (Set permissions on apk file)
ls -l /system/priv-app/Messaging_SEP81              (Check permissions - Should be: -rw-r--r-- 1 root root - not sure what 1 & 2 is)
ls -l /system/priv-app | grep "Messaging"           (Check permissions - Should be: drwxr-xr-x 2 root root)
reboot                                              (Reboot device)
</code>
Comment: What if after `mount -o rw,remount /system` , it shows `/dev/block/sda43 is read-only` ? Also, what's "Messaging_SEP81" ? How can I convert an existing app to be a system app?


Is it possible for wind to break the sound barrier?

Question: I understand that in nature wind would never get high enough, but I am just curious as to whether physics would allow this to occur or not.
Comment: Speed is relative, and the 'sound barrier' speed is usually relative to rest frame of the fluid (air in this case).  So it sounds like you want to measure the speed of the air with respect to itself which is confusing.  Can you clarify what you mean?  Give an example setup maybe.
Comment: "sound barrier" was a silly expression in headlines in the fifties. This barrier never existed, exept for the brains of reporters/journalists. In my alma mater, You could see a piece of the "sound wall" (german for sound barrier) in a exhibition. This was done as an 1st of april joke in early 50ties. Hundreds pf people came to see that pile of bricks.
Comment: Possibly related: http://physics.stackexchange.com/q/1717/71
Comment: Yes, it's possible.  Unfortunately I don't know much, but Wikipedia  can at least get you started. http://en.wikipedia.org/wiki/Aerodynamics#Supersonic_flow
Answer: I think that some confusion is here.
Wind speed is determined by differences in the air pression between two points. The max. limits that we observe must set the max wind speed. Wind is the movement of a mass of air. The Sound speed determines the sound barrier. Sound speed is determined by considerations about density, temperature... and is a property about the relative speed of the wavefront of a sound event (a perturbation of te medium - air, that propagates) in relation to te the air (considered at rest). The speed of sound in relation to the ground is the vector addition/subtraction of the sound speed (+-340m/s) with the speed of wind in relation to the ground. The max wind speed is observed in the jet streams in altitude and in the tornados and hurricanes at surface. Somewhere we can find the max speed of the exhausted air in the jets and determine if air moves trhu the air with a speed superior to the speed barrier. Nothing prevent this from happening with enough thrust. I've no time to search now, sorry.
EDIT add:
There is is need to search. The exhausted mixture of jet engines, not beeing wind but mostly a mass of air, can travel thru the atmosphere at speeds much superior of sound barrier. If it is was no so the jet planes could not cross the sound barrier.
So, inspite of the confusion in the question, I the short answer is a Yes (a mass of air can travel faster than max sound speed).
Answer: Wind is caused by differences in pressure. Wikipedia's discussion of atmospheric Wind is here.
However I suspect that what is requested is whether the velocity can ever exceed the speed of sound for air > Mach 1 ie supersonic wind. Well there is such a thing as a Supersonic Wind Tunnel which is generated by pressure difference ratios of 10 or so. This corresponds to the use of a nozzle with those pressure ratios between input and output streams. There are also videos  of objects in these tunnels.
Comment: In dimensionless units!
Comment: @dmckee :"Nozzle pressure ratio" - not a single word or name though. There are formulae for this topic in the updated links. A mathematical model is possible I suppose.
Comment: *"pressure differences of 10 or so"* ::gets out the Red-Pen-O-Death to mark up offending paper for lack of units::
Comment: Do you have a name for the dimensionless number in question? My first pass at building one was not very convincing.
Answer: The hypothetical Hypercane only has winds of around 800kph, so even this extreme situation is well below the soundspeed.
I'm not so sure that some gas giants might not have local winds in excess of the sound speed, here is wikipedia on Neptune
"Neptune has extremely dynamic weather systems, including the highest wind speeds in the solar system, thought to be powered by the flow of internal heat. Typical winds in the banded equatorial region can possess speeds of around 350 m/s, while storm systems can have winds reaching up to around 900 m/s, nearly the speed of sound in Neptune's atmosphere. Several large storm systems have been identified, including the Great Dark Spot, a cyclonic storm system the size of Eurasia, the Scooter, a white cloud group further south than the Great Dark Spot, and the Wizard's eye/Dark Spot 2, a southern cyclonic storm."
I suspect Gas Giants can have high local wind speed with respect to the local speed of sound, because wind systems may extend to great depth/pressures, where the sound speed is much greater, so that the ratio of soundspeed at depth, versus soundspeed high in the atmosphere can become quite large.
Answer: Pure air sound velocity is very high and is not attainable for the atmosphere pressure differences. However in a two-phase mixture (air-water, for example) the sound velocity can be very low and comparable with the wind velocity.
Answer: Wind speed is the speed of an air current. The laws of physics don't have a privileged rest frame, so it can't have a bounded speed.
Imagine you're in a supersonic jet travelling faster than the speed of sound. From your point of view, you are stationary and the air is moving. Hence, the air appears to be moving at supersonic speeds.
Answer: I would suggest giving the subject matter a platform, obviously atmospheric wind currents bound within its own air pressure constraints could never naturally reach critical mass. However applying this theory to a directed finite point, one could suggest that using frequency adaptation, within a weapons platform similar to haarp technology, a high frequency air pressure canon could induce wind speeds with enough force to cause a sonic boom, good luck holding the weapon.
Answer: of course it's possible since the wind is not a pulse through air, it's air which moves. While in the case of sound you know air doesn't move, the molecules oscillate.


Red wavelengths for everyday photography

Question: I've done a lot of research regarding filters as I'm about to do a modification on my DSLR for astrophotography. I've settled on removing the existing IR filter and replacing it with one the will still allow H-alpha (656 nm) and S-II (672 nm) plus the visible spectrum below that.
  My question is..if the eye can see red to approximately 700nm (before it reaches near-IR), why do most stock IR filters cut off below 650 nm ?
Answer: With few exceptions, data for infrared filters are not published for the region from 700 to 900nm. This is because most infrared filters are offshoots of the Wratten gelatin filters recipe. These were made by dissolving dye in gelatin and then floating the liquid gelatin on the surface of water. The gelatin was then allowed to gel and then lifted from underneath via a wire frame. The dried gelatin filter was then over-coated with lacquer. Often these gelatin filters were sandwiched between two sheets of optically flat glass.
Anyway, infrared radiation is strongly absorbed by matter. Most gelatin filters begin to absorb infrared beginning at about 2000nm and fully absorb at about 3000nm. Most glass infrared filters fare worse. The typical absorption curve is generally published for the region 750nm to 3000nm
To pass the frequencies you need, the filter would likely need to be made of quartz. I think none are available at affordable prices. Perhaps you can find such a filter under "specialized filters for science". I don't think you will find them in the general photographic community.
Comment: Why are you mentioning 2000 and 3000nm? The question was asking up to about 700nm which is fine for glass. Silicon detectors for the most part don't go to 3000nm anyway.
Comment: @ Eric Shain  --
Photographers generally think about colors (frequencies) a filter blocks, and rarely think in terms of frequencies transmitted.  UV filters are used to block ultraviolet but an IR is generally mounted to transmit IR.
Most photographers never venture into scientific imaging (medical, astronomical, etc.) these often image in ranges far from the visual range.
For the most part: Infrared spans 700 900 nm. Since infrared radiation is emitted by warm bodies, by tungsten lamps, by electronic flash, and LED, etc. there are many potential situations to image in this region.
Comment: I completely understand and agree with what you just related, its just that it is not relevant to the question which was about wavelengths within human perception (<700nm).
Answer: Camera imaging sensors are much more sensitive to longer wavelengths than human vision. The normalized response of the "red" sensitive cone cells drops off rapidly above 640nm. A camera without ir filters will be much more sensitive to red light that contains material percentages of photons with longer wavelengths. Digital color cameras have such filters built-in just to prevent overly strong response to images containing high amounts of longer wavelength light. These filters attenuate some long wavelength light that is visible to more accurately render color perception. Such items include flames and red hot embers, but also everyday things such as vegetation. Green leaves typically have high reflectance levels at long wavelenths. Without an IR filter a color camera will produce a yellowish cast to green leaves in daylight.
However, these IR filters have too sharp a cutoff when trying to capture longer wavelengths in astro-photography. Replacing these with filters that pass specifically desired, longer wavelengths allows better capture of this light. It comes at the cost of poorer color rendition for general camera use.
Eric, in the comments, posted a link that discusses a wide range of wavelength issues in color rendition. A good overview which includes graphs of various sensor and filter responses.
Comment: Thanks for the insight guys...makes sense. Spencer photography and LifePixel both do an Astro conversion with a replacement filter that passes visible up to 700nm. That gives me the option to filter for H-beta, OIII, H-alpha , S II  and RGB as needed.
Comment: You link doesn't really compare human perception to silicon detectors very clearly. I think http://www.fen-net.de/walter.preiss/e/slomoinf.html has a pretty good plot.
Comment: @EricShain. Camera sensors, sans filters, have responses that don't vary much between 600nm and 800nm. Some technology becomes more sensitive while others the reverse. But they all are quite responsive in comparison to human vision with it's strong drop above 640nm. Your link contains good info. Here's another than is specific to why color cameras need IR filters. https://www.adimec.com/implementing-a-visible-camera-for-both-daylight-and-lowlight-vision/


Identifying chiral carbons

Question: Looking at this structure, I would say this molecule has five chiral carbons. However, its IUPAC name (3R,4R,5S,6R)-3-amino-6-(hydroxymethyl)oxane-2,4,5-triol suggests that there are only four. Which is it?
Comment: The diagram you drew doesn't indicate the stereochemistry, so I am curious as to how you came up with that IUPAC name.
Comment: It is the hemiacetal carbon atoms. It is chiral but racemization can occur through the open form of the molecules.
Answer: The structure as drawn indeed contains 5 chiral carbon atoms.  However, the one carbon that is bound to two oxygen atoms is called the anomeric carbon.  It is part of a hemiacetal moiety in the structure you have drawn.  That means that at room temperature and in aqueous solution, it will equilibrate reasonably quickly between:

One enantiomer of hemiacetal
An open-chain non-cyclic molecule where the anomeric carbon is an aldehyde moiety and is thus not chiral.
The other enantiomer of hemiacetal.

Thus, for many applications it is probably better to think of this molecule as having only four "fixed" stereocenters.

Identifying chiral carbons


Do fans stop spinning when MacBook Pro's are in sleep mode?

Question: I have a MacBook Pro Mid-2009 running Yosemite 10.10.3, and I installed Macs Fan Control which is similar to smcFanControl. Basically, whenever I put my Mac to sleep the fans stop spinning (I have them set at 6200rpm) and the Mac is asleep but less than a minute into sleep mode the fans start spinning again (I can tell since they start at 6200rpm) but the screen is still off. Is my Mac really going to sleep or does the fact that the fans are spinning mean that it's not asleep. By the way I have wake for network access turned off.
Answer: Fan function is regulated by temperature sensors.
As long the temperature is to high the fan keeps working regardless if you are in sleep mode or not. Since you turned off the heat source that action is usually very short.
Somewhat like you car fan, that continues to spin even if you turn off the engine if the temperature is to high.


Effect of extremely hard water on marine life?

Question: When researching water quality standards, I found that a minimum and maximum was set for water hardness. Several sources also state that water can in fact be too hard. The question is how does hard water harm marine life? I understand that it is required to reduce the toxicity of Hydrogen ions and other trace metals, but cannot find anything concerning the effect of water that is too hard.
Comment: Water hardness refers to the concentration of calcium and magnesium ions in fresh water. Has nothing to do with pH. In salt water, these ions are at much higher concentrations and thus water hardness makes no sense in salt water.
Comment: I don't have any direct adverse effects of extremely hard water but marine organisms have quiet specific ranges of hardness according to http://www.cichlid-forum.com/articles/hardness.php
Comment: [Wiki](https://en.m.wikipedia.org/wiki/Heavy_metals) Found relatively easily on wikipedia. Affects cystein residues in proteins, binds to DNA backbone, affects prostetic groups, etcetc.
Comment: You should define hardness in your question. There a few types of hardness defined. In general, increasing hardness is a result of increasing pH and vice versa; which means hardness (increasing from another reason) may also lead to a n increase in pH. marine water is not just a simple composition of salts... edit for dummies added.
Answer: Hard water helps in direct and indirect ways.
Indirectly, hard water plays an important role in regulation of pH. Respiration and other physiological activities release substances into water that change the water pH and the ions that cause hardness act as buffers and help maintain pH.
Directly, they determine the ease with which osmoregulation occurs. The harder the water, the lesser the influx of water. So the fishes act like an open system and are influenced by the surrounding water.
There are very few fish who absolutely need soft water to survive.
Since your pH and hardness are pretty low, it allows you to raise multiple fish from South America. You could do tetras, dwarf cichlids and New World cichlids, Plecos as well.
Potentially discus and altum angelfish as well if you're up to the huge challenge.
However, livebearers will not tolerate this type of water. That goes the same for African cichlids.
Otherwise hard water is completely fine for marine life and other aquatic species.
Link
Link
Hope this information helped!
-Sartoaster
Answer: If you look at the Wiki text on Hard Water, Marine hard water is not mentioned once. That's because it's a term used mostly to qualify freshwater.
Sea water doesn't vary alot in the oceans, only in inland seas and near estuaries and glacial melt, it's called brackish water, brine, not soft seawater.
Sea water which undiluted is called salty, highly saline, high salinity, water, not Hard Seawater.
Marine life isn't affected by the stone type mineral content of the seawater as much as by the highly reactive salts, both sodium and chloride are very harmful to life compared to most stones a the less soluble mineral salts.
Seawater contains a lot more calcium generally than most river water, even though some river water can be completely saturated in calcium and have very high PH. Some fish can adapt to a wide range of soft water hardness, and some fish can adapt to very salty water, but most fish are specialists who don't live in wildly varying ecosystems, only in the sea and in constant softness freshwater.
Read some aquarium chemistry experiments. they are aquariumabulous and will give you a lot of knowledge about marine biogeochemistry. It's pretty interesting to look at any pond and river and plant and know what chemistry it has, what it needs, and the processes changing it, it's quite simple to learn too, just learn some basic experiments and guides on water and pedology organic and mineral reactions and biology.


What should I use to reassemble single 35mm film negatives into strips for scanning?

Question: I am beginning to scan my negatives. From my early days of photography some 50 years ago I have found in my archives single 35mm negs that I want to reassemble into a strip to scan. How can I reassemble them into 5 or 6 frame strips? What tape should I use?
Comment: which kind of scanner are you using? strip holder for flatbed scanners can easily be fed with (multiple) single negs, too.
Answer: Most systems for scanning film have the provision for scanning mounted slides.
For example, the Nikon slide scanner:

has a slot right in the front for single slides (you can also get attachments for batch slides or rolls of film - but the default is single slides).
Simiarlly, flatbed scanners have a way to scan mounted slides:

Mounting a bit of film is less likely to be destructive to the film if already cut and also makes for easier long term handling of the film.  This also reduces possible issue of deterioration from the parts used in splicing the film together to get a strip back.
Slide mounts themselves are reasonably inexpensive (b&h) especially when compared to the specialized tape (3M 8421 Photo Splicing Tape - 1⁄2" x 72 yards (uline) it appears to be difficult to get it in smaller units (google)) needed for splicing and the risk of damaging the film itself.
Comment: Many of us have leftover slide mounts in the back of the closet.  One might be able to scrounge enough by asking around.
Answer: I wouldn't recommend using tape to put old 35mm back together. Your best bet, if you do want strips, is to get an old 35mm film splicer. These are designed for movie film, but they can be used for normal film stock. Some work by using special tape (which is expensive), others use cement and there are some which use heat (although I wont recommend this). Just search Ebay for either splicer or splice and you should find loads of old splicers and specialty materials for quite cheap. Sadly, areas which are spliced are subject to faster deterioration, which I understand is a worry.
Another option is to use a standard flatbed scanner. You don't need to put the film into strips and don't have to risk damaging them. You just lay them ontop the scanner glass. You do have to use an angled card for it. Instructions:http://www.popphoto.com/gear/2011/07/how-to-scan-negatives-using-standard-scanner-0 . I use a flatbed for my medium format negatives, as you can't get purpose built medium format scanners cheaply.


Help compiling multiple .ino file code with code! (I'm not sure what to name this)

Question: Ok, so i'm trying to make This Project and the code comes all in different .ino files but in the video its all in one program. So how do I compile all of the code onto the arduino? (By the way the code is on step 5 in a .zip file) Thank you!
Answer: One of the .ino files is likely the main code file.  Name the enclosing folder with the name of the .ino file, then compile it as normal.
In this case, AbHhGD.ino is the main file, and its folder should be named 'AbHhGD'
The comments indicate there are missing libraries you likely need to install.
Comment: Ok so I just rename the folder that has everything in it to AbHhGD and then compile abHhGD.ino?


Chocolate chip cookies: too much butter

Question: I made a chocolate chip and snicker cookie batter. But I added double the butter not realizing what I had done I chilled the dough until the next day. The next day when I took the dough out of fridge it was hard like solid hard and I realized I had put to much butter in it.   So my question is can I double the rest of the ingredients and add to already mixed mixture after the mixture softens?   please help
Comment: Can you please tell us the full recipe and method for these cookies? If it uses the creaming method, you may have a difficult time doubling the recipe if the butter's already included.
Comment: Seems like it should work to me
Comment: 3/4 cup butter (1 1/2 sticks) unsalted butter.  3/4 cup light brown sugar, 1/4 cup granulated sugar, 1 egg, 2tsp vanilla, 2cups flour, 2tsp cornstarch, and 1tsp baking soda.    1cup snickers chopped and 1 cup semisweet chocolate chips.      I added 3   (1/2 sticks of butter) I was supposed to add 1 (1/2 a stick butter and a half).  I dnt know what to do with it now.  So i was wondering if i double the rest of ingredients it might work. but since the chocolate chips and snickers are already mix dnt know how that will work.
Comment: If I still have any hope to save this batter any assistance/advise will help.
Comment: That's just the ingredients. You need to state how the cookies should have been assembled (i.e. the whole recipe).
Answer: The hoighty-toighty pastry chef answer would be of course not. Any practical cook's answer is of course.
It will be a bit different, which is why the pastry chef rejects it - everything must always be perfect and waste/cost are irrelevant.
It won't be a waste of ingredients, which is why practical cooks accept it.
You should probably add the sugars to the softened dough, then add egg, then the dry ingredients (previously sifted together) roughly matching the SOP of cream butter and sugar, add egg, add dry. But don't overdo the mixing, since the currently over-buttered dough already has the flour in it. That is the main reason why it's dead to the pastry chef.
Comment: Good observation about practical v. purists. If OP follows your last paragraph he/she would be well served by having the current batch at *almost room temperature,* and the ingredients to be added *at* room temp before remixing. I'm undecided if the added flour should be All Purpose Flour, or Cake Flour. (and I just noticed this is a month old Q)

Chocolate chip cookies: too much butter


what is halting problem?

Question: i have researched it on wikipedia and it produces me an unusual example and stories about Turing,so what i understand is if an program run in loop,an electronic device in cpu or in computer structure would stop that program,or an code will be processed by the input to decide if the program will be executed or will be halted after that.So what is the halting problem actually?
Answer: Consider the set of all possible pairs $ \langle M, w \rangle$, where $M$ is a Turing machine and $w$ is some string on a fixed alphabet. Also note that some $M$ may halt on input $w$, and some may not.
Basically, the Halting problem asks to create a Turing machine that takes a pair $ \langle M, w \rangle$ as input, and eventually halts with answer "YES" if $M(w)$ halts, and "NO" if $M(w)$ does not halt.
If you are familiar with programming you could interpret this problem as following. The Halting problem asks you to write a C++ program which reads another target program together with its input written in C/C++, and always stops and prints "YES" if the target program eventually stops on the input,  and prints "NO" otherwise. Note that your program must work for any finite size of target program and any finite size of input.
As for its history, this is one of famous David Hilbert's 23 questions posed in 1900 at the Second International Congress of Mathematicians in Paris, and later in 1936 was solved by Alan Turing to show that such algorithm deciding on all possible pairs $ \langle M, w \rangle$  cannot exist.
This Wikipedia article provides a formal definition of the problem and sketch of proof.
Comment: @Lan... `while (x > 0) { x=4; }` loops forever, for instance, if initially $x$ happens to be $>0$.
Comment: i'm not familiar with those symbols but i familiar with c  and bash and javascript.But how can an program can run arbitrarily and loop forever?An program(an stream of electric signal bit) will be executed(the processed bits go to cpu and go out RAM and peripheral devices).Now when the program has been sent out,it will have to be repeated by the ROM or RAM and keep take input data.The program can run background and manipulate the other programs but it doesn't mean that that program will run arbitrarily?
Answer: You should be familiar with the concept of coding of a program if we want to explain Halting Problem informally without using formal definition of Turing machine.
Coding of a program contains all instructions that the program follows to process its input. Let's call coding of program $P$ as $<p>$.
Suppose someone gives a $<p>$. Can you understand will $P$ outputs anything and halt if it runs input $w$? You can not unless you run $w$ on $<p>$ and wait to see its result.
The point of this experiment is that if $P$ halts you will understand at a time in future, but you'll never understand if stuck in a loop. Note that you don't know how long you should wait to see its result and this makes the halting problem hard.
Halting problem says there is no program $\mathcal{P}$ that given $<p>, w$ as its input and can determine whether $P$ will halt running $w$ or not.
To better intuition, let's define two languages.
$$L_{halt}=\{(<p>,w)| \text{P halts on w}\}\\
L_{\overline{halt}}=\{(<p>,w)| \text{P  doesn't halts on w} \}. $$
As I explained above you can enumerate $L_{halt}$ but you can't do it for $L_{\overline{halt}}$. Halting problem says you can't write any program that given $(<p>,w)$ and decides whether $(<p>,w) \in L_{halt}$ or $(<p>,w) \in L_{\overline{halt}}$.
Edit: I changed check membership of $L_{halt}$ to enumerate with the subtle point Yuval mentioned.
Comment: "Can you understand will $P$ outputs anything and halt if it runs input w? You can not unless you run $w$ on $\langle p\rangle$ and wait to see its result." Not necessarily. There could be other ways.
Comment: "[Y]ou can check membership of $L_{halt}$ but you can't do it for $L_{\overline{halt}}$." The two problems are equivalent, and none of them is computable. You can *enumerate* $L_{halt}$.
Comment: @YuvalFilmus I can imagine of other ways if, for example, we knew $$ is a C++ code or any other specific programming language.  But I think when we have no idea what is the coding about and we just know that is *a coding*, there is no other way. Would you please name some other ways if you know?
Comment: The problem is that it's hard to prove that there is no other way.
Comment: "Halting problem says there is no program P that given ANY ,w as its input and can determine whether P will halt running w or not". You should mention that the Halting Problem says there is no program "P" that can do that for every other (program,input) pair.
Comment: @doubleOrt My statement isn't wrong, though the statement "there is no program P that given ANY ,w as its input and can determine wheter P will halt running w or not" is correct. The point is even for one pair (program,input) there is no program to DECIDE it.
Comment: @DsD I think I was talking about the fact that it should be mentioned that the Halting Problem is impossible to solve for EVERY program, not just any program. Nevermind.

what is halting problem?


How can you setup auto archiving for a document library?

Question: I have been tasked with finding a way to auto archive documents in a document library after they reach a certain age. Is this possible within SharePoint?
Answer: You could rely on  Information Management Policies and setup a Retention policy to either archive, remove, etc  (http://www.dynamics101.com/2013/03/sharepoint-information-management-policy/ or http://office.microsoft.com/en-001/sharepoint-server-help/create-and-apply-information-management-policies-HA101631505.aspx)
Answer: example is provided step by step.
credit to: Peter Kalmstrom.
Link: https://www.youtube.com/watch?v=ZYj6bhvzYvI.
if link expires, here are the steps that are also credited to Peter Kalmstrom.
Step 1A
1.Open Site Contents.

Sharepoint Add an App IconSelect add an app and create a new Document Library .

3.Open the original library. From the Library tab, go to Create Column to add a new column for status.
Sharepoint Create Column
4.Select the Type "Choice (menu to choose from)" and enter choice values (in this case New, Ongoing and Expired).
Step 1B
1.From Lists and Libraries, open the original library.
2.From the List Settings tab, click List Workflow and create a workflow.
3.Open a summary page for the new workflow.
4.Under Start Options, check all checkboxes.
5.Go to Edit workflow under Customization and set the  Transition to Stage as "End of Workflow".
6.Press Condition and select If value equals value. Now you will get the text "If value equals value" under Stage 1.
7.Click on the first value and set the return field to the newly created column name. Here it is Document Status.
8.At the place of the second value you will get a dropdown with the Choices values that you set while creating the column. Select the value that you want to use as a trigger for the move to another library, here Expired.
9.Press the Action button and select Copy Document. Now you will find the text "Copy Document in  this library to this library" at Stage 1.
10.Click the first this library and set it to Current Item
11.Set the second this library to the Archive library you have created.
Move Docs in SharePoint Workflow

12.Press the Action button and select Delete Item. Now you will find the text "then Delete item in  this list" under Stage 1. Click this list and select Current Item.
13.Click on Publish.
Comment: Please add the steps from that post. If the example is too long, atleast provide a summary. Too many times, these links expire and the question is left unanswered.


Complexity of computing the order of a permutation group

Question: Given two permutations $g$ and $h$ over $n$ elements (i.e., members of $S_n$), what is the complexity of computing the order of the subgroup generated by $g,h$? Or just of deciding whether the subgroup is of order $n!$ (i.e., all of $S_n$)?
Answer: The order of permutation groups can be computed in polynomial-time. In fact, I believe even in $\mathsf{NC}$ and also nearly linear Las Vegas time. See, e.g., the book by Seress.
For reference, subgroups of $S_n$ (and algorithms related thereto) are typically called "permutation groups" rather than merely "subgroups (of $S_n$)". So you can google "permutation group algorithms" etc.
Answer: As a complement to Joshua Grochow's answer:
Computing the order of a permutation group given generators is in P by Schreier–Sims algorithm, see also p. 8-9 of these lectures notes by Luks. Just as membership in permutation groups, the problem was believed to be P-complete by many researchers, but it was finally shown to be in NC by Babai, Luks & Seress.
The complexity of problems for permutation groups was extensively studied and their complexity was gradually settled for abelian groups, nilpotent groups, solvable groups, groups with bounded non-abelian composition factors, and finally groups (see work by Babai, Cook, Furst, Hopcroft, Luks, McKenzie, Mulmuley, Seress and many more).
Comment: When did Mulmuley work on permutation group algorithms? (Other than the Kronecker problem, which is arguably a very different kind of thing...)
Comment: Perhaps I should not have included him in the list, but I was referring to this paper: http://link.springer.com/article/10.1007%2FBF02579205 that allowed results on permutation groups, in particular for this paper of Cook & McKenzie: http://epubs.siam.org/doi/abs/10.1137/0216058.
Comment: Fair enough (it looks like he didn't know he was working on permutation group algorithm, but Cook-McKenzie showed it was equivalent).


Difference between "unto" and "to"

Question: What are the differences between "unto" and "to"? It seems that in many contexts where the word "unto" is used, "to" could be substituted and would be perfectly correct. It reminds me of flammable/inflammable, where "flammable" came into use because the "in" in "inflammable" caused people to think that it meant not inflammable. Is this a similar situation?
Answer: To did not come from unto (if anything, vice versa), so the situation is not the same as with flammable and inflammable.  Though to is an older form, unto was never as prevalent, and is now either archaic, or used in limited contexts, such as shown here (Idiom: unto itself).
Comment: The curious may find examples illustrating the wide range of early senses of *unto* [here](http://quod.lib.umich.edu/cgi/m/mec/med-idx?type=id&id=MED50055⪖=all&egdisplay=open).
Answer: The origin of unto, as reported from the Oxford English Dictionary is the following:

ORIGIN: from until preposition with to preposition replacing northern equivalent till preposition.

Therefore, the relation between to and unto is not the same relation there is, e.g., between touchable and untouchable.

One of the meaning of unto reported from the same dictionary is until, till. The dictionary reports also that unto indicates "regular recurrence within specified units of time, as day unto day."

Doctor Manley…praises Kate unto this day.—I. Maclaren
Comment: Though *to* can replace *unto* anywhere it appears in your examples, so *unto* still sounds a little archaic, even in those contexts.  The only times *unto* is still used are in idioms, where it cannot be replaced by *to* (as in the idiom "it is a [noun] *unto itself*").
Answer: In the King James "unto" seems a bit like placing something like a gift or idea or anything with some kind of substance unto the person, place or thing/idea of acceptance. exp..."the river flows over the banks and unto the road" or "I wrote a letter unto you"
Now the word "to" is more of an expression in grammer in which the person, place or thing/idea is directly or indirectly expressed. exp..."I went into my room to write a letter unto you" I went to write unto you.
Comment: Welcome to English Language & Usage.  I find your answer a bit hard to follow. You might want to reread it and be more precise about your sources.  If you're going to cite to the King James translation of the Bible, why don't you consider using actual verses as examples and then comparing them to more modern translations of the same verses?
Comment: The KJV is the first place where I found `unto` used regularly instead of `to`. I am looking forward this explanation.
Answer: "Unto" is just an older form of "To".
I've never seen anything to suggest that there was a confusion regarding "unto/to" akin to "inflammable/flammable".

Difference between "unto" and "to"


How far ahead can I bake puff pastry?

Question: I'm hosting a party at our home in a couple weeks, cocktails and appetizers. I have a recipe I like for little meatballs in puff pastry. I was wondering if I can bake them all ahead of time and keep them in the warming drawer or oven or if I should bake each batch fresh.
Comment: Welcome! How far ahead -- a day, an hour? Do the meatballs have a lot of sauce and/or grease?
Comment: An hour ahead or so. I serve sauce on the side, but the meatballs are a little fatty. The event last 3-4 hours. It's a neighborhood holiday party and we'll have four large groups come in the house every hour. We hosted last year and I made each batch in between but I'd like to bake them all off. I'm just worried about the pastry getting soggy
Answer: Puff pastry itself holds fine a couple days (and the raw dough can be kept frozen months!); it's normally very dry so there's very little difference between baked fresh and "old". As long as you don't burn it and don't make it soggy when reheating, the pastry will be fine. OTOH if you keep it on heat, it will start getting too dry and unpleasant in some 3 hours or so.
The meat stuffing is another thing you should worry about. 4h on very modest heat will dry it up badly.
Just bake everything ahead of time, leave in the open in room temperature or even refrigerate and reheat every batch before serving.
Answer: It should be fine if you uncover the pan of the meat puffs. It will prevent sogginess. That sounds very stressful to keep baking them after every group. I would rather have them a bit soggy than have to worry about the puffs during the party. Good luck!

How far ahead can I bake puff pastry?


Can you use an Xbox one console without internet?

Question: I am planning on buying an xbox console,
but I have no internet connection.
Am I going to be able to make use of it offline?
out of box set-up will be done at a relatives house where there's a connection.
Answer: Yes you can use your console offline. According to this official page by xbox.com, this is what you can and can't do:

When your Xbox is offline you can:

Watch TV (though you need to be online for OneGuide listings)
Sign in to your profile (if you've signed in online before)
Change console settings (except for profile and family settings; content controls remain in place while offline)
Play games (provided you've set this as your home Xbox or have a game disc)
Save game clips and screenshots
Earn achievements (however, there's limited offline space for game captures and achievements, so you should go online every so often to sync them)

Activities your Xbox must be online for include:

Playing games and apps that require the internet
Syncing game progress and playing saved games from a different Xbox
Using social features like friends, messages, and parties
Shopping for games, add-ons, movies, and so on
Updating games, apps, and your Xbox console

However, the page also specifies that:

You must be online when you set up Xbox One for the first time. Without an internet connection, you can't finish setup. After your Xbox has updated and you've added your profile, you can go offline.

On the page I linked you can find help on how to set up your Xbox to use it offline.
Answer: Yes you can, but the functionality is very limited, as most games of today require an on going connection of some kind. Also with the constant updates required by both the games and the console itself, it would be difficult for you to do much with the console. Also only some games can be played completely offline, so make sure you do your research.
Comment: This is not accurate and doesn't reflect my experience.
Comment: @Eric if that is the case then please leave your own answer.
Comment: Many single player games still require an online connection, so definately research each game you plan to buy ahead of time thoroughly as Parzival suggested. I was caught off guard with how many games I own that I couldn't play when internet was down. I hear it is same with ps4.
Answer: Without an active internet connection, the Xbox One is basically useless - you cannot even connect to your own private network that doesn't even require internet...ie:  you have DLNA streaming content you want to watch but it won't see anything.   If you go to your Xbox One network settings and go offline, it shuts down the network interface so you are toast there.
Never had this problem with the Xbox 360 so Microsoft has pushed people into buying their Live service to use the console.
Comment: The other answers seem to contradict what you have stated.


My fermentation top popped, is it still salvageable?

Question: I started a Belgium style ale, about 1.064 og.  After 2 days I go check on it in the fermentation fridge and see that the lid of the bucket has blown open, blown the fridge door open, and krausen was everywhere. I don't know how long it was like this. I obviously closed it up again and closed the fridge. Is the beer still fine to bottle? How do I prevent this in the future?
https://i.stack.imgur.com/UWj2g.jpg
Answer: I would presume the beer is still good to bottle - but leave it (at least) for a full 14 days before attempting to prime/bottle/keg. I have had the plastic lid blow off the fermentation bucket on previous occasions. I put it back on and continued with the brew. Once the beer was a little more sour than I might have liked but it got drunk anyway... The rest was fine.
2 days after pitching the yeast, the beer should be fermenting vigorously and so the action of the yeast and hops should keep it relatively free of undesirable micro-organisms. In such situations I remember Belgian Lambic ales. They are fermented in open air with the lid of the fermentation vessel (barrel) removed. They are a popular style in Belgium.
Fermenting Belgian ale in a fridge is a novel idea. I am not certain if cooling adds much to the final product but I always approve of experimentation. To prevent the top blowing/flipping again, the gas must be allowed to escape from the fermentation vessel. So either the bubble trap (or vent) got jammed with krausen or there was no bubble trap and the lid of the vessel had snapped shut. Both situations would allow the pressure to build sufficiently to pop the top. Bubble traps often get "plugged" if the air space above the wort is small. The foam/krausen rises and gets forced into the bubble trap often blocking it (sometimes it blows free and the top stays on). In such a case use a bigger fermentation vessel or brew less beer at a time. If no bubble trap is used then consider fitting one. If the "old school" way of leaving the lid unsealed is used as a venting method then make sure the lid does not (somehow) snap back into place - effectively closing any vent for the CO2 produced during fermentation. Sometimes a bubble trap on top is too tall for a specific place (like a fridge) so, if all else fails, drill a few holes in the lid and cover with a plastic sheet/cap using some tape (on one side) to keep it in place. This is an easy way to let gas out and prevent most stuff dropping in.  Good luck!
Comment: In the picture included with the question, I can see that there is a bubble trap (this one: http://www.northernbrewer.com/three-piece-airlock ), but that it is full of wort, and probably clogged. As you say, barking pete, it looks like a bigger vessel or less wort would prevent the problem in the future.
Comment: Cooling Belgian style ales beyond certain point removes flavor, not adds to it.
Comment: "Fermenting Belgian ale in a fridge is a novel idea. I am not certain if cooling adds much to the final product but I always approve of experimentation."

This is an example of "English understatement". "Novel" does not always equal "good" especially if it departs from established practice for the ale type. Being "Not certain if it adds much" is a carefully phrased way of saying "IMHO It doesn't add anything". But who am I to say what is "right" and "wrong" when brewing. I always encourage experimentation even if I am "not sure" it will yield any useful result.


I want to move from Identi.ca to Twitter. Is there a way to map identities between the two?

Question: I've been using Identi.ca but too many of my contacts won't use it and I want to move to Twitter instead.  Is there a way to go through my list of subscriptions/subscribers and match those to tweeters, so I can do a bulk follow?
Comment: How would this be possible?  How would you be able to link the subscribers on Identi to tweeters?
Answer: As Wil has alluded to, that would require that your Identi.ca followers use the same handle as they do on Twitter. While this is likely, it is but by no means a certainty and thus unreliable.
The problem you present suggests that you don't follow that many people on Identi.ca. I would suggest enabling cross-posting from Identi.ca to Twitter, posting to Identi.ca that you're moving, and soliciting @-mentions on Twitter from those people so you can quickly find and follow them.
I don't know of a better solution at this time, I'm afraid.


What's the difference of the Userland vs the Kernel?

Question: I am trying to understand exactly what is userland? everyone that I ask says: "Anything that is not kernel". but it is not tangible for me. When I am reading that kernel can run that driver on the userland or something like that; I can't quite imagine what will happen!. So I will appreciate if someone set me straight in this regard.
Answer: On one conceptual level, the kernel is everything that runs at a "more privileged" level of hardware protection. That would be like ring 0 on x86 processors, system mode on ARM, kernel mode on MIPS, supervisor mode on 68xxx, etc. The kernel is usually interrupt-driven, either software interrupts (system calls) or hardware interrupts (disk drives, network cards, hardware timers).
On that same conceptual level, "user land" is what runs in the least privileged mode (ring 3 on x86 CPUs, user mode on ARM or MIPS, etc.). User land takes advantage of the way that the kernel smooths over minor hardware differeences, presenting the same API to all programs. For instance, some wireless cards might have extra control registers with respect to others, or contain more or less on-board buffer for incoming packets. The driver code accounts for these differences (sometimes by ignoring advanced or unusual features), and presents the same socket API to all programs.
Some processors (e.g. x86, VAX, Alpha AXP) have more than two modes, but the generic Unix architecture doesn't use the intermediate modes.
The programs and processes you see running in Unix or Linux or *BSD are the user land. Since processes are pre-emptible, you actually never see the kernel run, you just see side effects, like a read() system call returning, or a signal handler function running.
To answer your specific question, in Unix, Linux, *BSD a "driver" is usually some smallish piece of software that deals with the specific peculiarities of some piece of hardware: a network card, a disk drive, a video card. The driver software almost always neeeds to run in Ring 0/supervisor mode/kernel space in order to have access to hardware interrupts, or the mapped memory of the hardware or whatever. The driver takes care of specific hardware features, and makes that hardware fit into the kernel code's standardized or conventionalized view of how hardware should work. Therefore, running a driver in user land requires the kernel to show a userland program things like mapped-in memory or device registers or interrupts or other special features. That can be tricky, as the special features a device might require don't easily fit in to the usual Unix-style API presented to user land programs. Also, scheduling is an issue, as user land programs don't typically respond to interrupts all that rapidly.
Comment: @r004 - see edits. I used wireless cards, but driver software makes SATA, SCSI and IDE disks all look the same too, despite vast differences in what they can do.
Comment: "*The programs and processes you see running*" In Linux ps will show kernel threads which don't belong to any userland process. `ps --ppid 2` will only show the kernel threads.
Comment: the kernel smooths over minor hardware differeences. plz expand what you mean by **smoothing over** and **miner difference** if possible
Answer: Most modern CPUs have a kernel or supervisor mode, and a restricted user mode.  This is a hardware feature of the CPU.  "Userland" is another name for code running in user mode.
One big difference between the modes is with regards to how the MMU of most moden CPUs acts under them.
An MMU allows a kernel to rearrange blocks (or pages) of RAM so they appear to code in a different order than they are physically in RAM, and also cause user mode code to trap or "fault" back to kernel mode if certain pages are accessed.  User mode cannot change what the MMU does, only the kernel mode can do that.
So, the MMU allows kernel mode code to do all sorts of cool things, like:

"arrange" or "map" memory to user mode code so such code thinks it has contiguous RAM.
implement a dynamic memory management scheme where a process would need to ask for memory before trying to use it.
stop user processes if they use memory they aren't supposed to.
swap out least-used pages to disk if free memory runs low and swap them back in when a process tries to access them.

You can see that the MMU, along with kernel/user mode, is the cornerstone of a multitasking operating system, and using these tools one can create a system that works with higher-level things like the idea of processes.  A kernel  is maintaining page tables for each process and basically reprogramming the MMU before it switches to user mode and gives control over to a process for its timeslice.  Things like malloc and stuff where a process acquires memory is causing the kernel to modify MMU page tables.
Again, user mode can't do anything to the page tables (and doesn't really need to know they exist), if it needs memory, it needs to call the kernel, which causes a switch from user mode to kernel mode.  CPUs provide a simple mechanism called a software interrupt to do this, and there are other faster ways that the Linux kernel uses.
Because of this protection that exists in user mode, if a program does something like crash or go haywire and overwrite itself, the kernel can stop this process.  In kernel mode, this protection does not exist, so the kernel will stop working and thus your entire system will also stop working. When an unrecoverable error like this happens in kernel mode, it is called a kernel panic. See What is a "kernel panic"? for details.

kernel can run that driver on the userland

The kernel or supervisor mode of CPUs also prevents user mode from directly accessing I/O devices, the idea is that it has to call the kernel to do that. In Linux, code that talks to devices directly (they run in kernel mode) are device drivers (a type of kernel module, you can manipulate them with commands like lsmod, insmod, modprobe, and rmmod).
What happens if your device driver, which would be running in kernel mode under the simplest setup, has a bug and does something nasty like overwrite random stuff in RAM (and since it's in kernel mode, it has unrestricted access to all RAM and can overwrite the kernel itself).  It be nice if we could get the device driver running in user mode, so that it can't do anything to the kernel itself or other processes.
Unfortunately, switching from user to kernel mode (called a context switch) is slow, since basically the entire state of the CPU has to be switched in and out for each process or the kernel itself.  So, we have two things at odds, safety or speed, and thus it's a point of contention and design.
Kernels that try to do as much as possible in user mode are called microkernels, and Linux is the opposite, which is called monolithic.  User-mode drivers do exist for Linux (look into FUSE for an example) and there's even a framework that allows it.
Comment: video drivers run partially in userspace. they ran even more in userspace back in the days before Kernel Modesetting (aka KMS and its brother, DRM/DRI).
Answer: Building on what Bruce said, all code that is provided to the kernel must be trusted.  If there is someway that malicious code can be executed by the kernel, it's game over.  That is where the privilege separation of user executed code and kernel executed code comes into play.   Code that is ran by a user doesn't necessarily have to be 100% free from evil.  It does not  get executed directly by the kernel.
Userland programs simply interact with exposed portions of the kernel, such as APIs and loaded modules.  An example would be iptables.  There are several kernel modules (.ko) or 'drivers' that actually do the work of iptables, they're part of the netfilter framework.  When you execute commands using /sbin/iptables you're using the userland component which in turn communicates with the netfilter modules that are loaded into the kernel.  This allows separation so that user code cannot inadvertently be executed by the kernel.
Answer: One way to get a good and thorough understanding of these concepts would be to go trough a tutorial like those on osdev.org or James Molloy's Tutorial.
Linux has a monolithic Kernel, this means that its code runs entirely in ring 0 on the x86 architecture, as Bruce stated. Thus, having full control of all the resources, the Kernel will manage all requests for them by user level applications (running in the least privilege level 3)
Think of this: if applications from user space had full access to virtual memory - RAM - they could trash everything, from other processes' stacks or heaps to kernel's internal buffers. The kernel maps pages to each process's page directory, and if the application misbehaves by trying to access a location which does not belong to its address space, then it will be forcedly shut down.
Next, think what would happen if each program would have direct access to a printer or some other output device. Two concurrent instances of processes trying to print to the printer would scramble everything up, but if these requests go trough the kernel, then they will be queued and treated separately, resulting in two separate printed pages.
Further, since machines usually have a smaller number of processors than processes currently running, the kernel uses a scheduler to switch between processes, each getting its own finite time to use the processor. When this time expires, it will be moved to the end of a list of active processes, or to a list of inactive ones - if the process has been waiting for data from some device. This way, all processes seem to be running concurrently although only one process, or the kernel gets to use one processor at any given moment. This concept is called pseudo parallelism.
Regarding your last question on drivers on user land: this is possible, still, the kernel keeps full control over the communication with the device. For example, the Kernel may map a region of kernel memory to the user-space driver's memory region, thus giving it access to the device memory. Kernel still has the power to forward changes to the device or not. This user land driver will provide with a nice interface for controlling the device to other user applications, and if somehow the driver crashes, there may still be good chances for it to be reloaded without having to reset the machine. If the driver had been in kernel space, say a module, if the module got stuck and can't be unloaded, then it can't be re-loaded either because it's symbols are already there, so the only chance is to reset the machine.
To conclude, applications like cat top or a "hello world" only run in user space, having access to system's resources ONLY trough the Kernel API, which is a set of functions called system calls. So, when an application issues a read() system call to read from a file, then the kernel takes control of the processor, reads data using the appropriate driver (like HDD driver), and then copies this data back into the address provided by the pointer passed to the read() system call, letting the application continue to run as soon as this data is available.
Answer: In Unix/Linux operating systems, we differ between user space and kernel space. That are just synonyms for userland and where the kernel belongs to.
You can understand it as follows. You can interact with all that goes on in the user space. Which is not the case in the kernel space. Daemons, libraries and applications belong to the user space. All code which runs outside the operating system's kernel belongs to the user space (userland).
The kernel space is where the kernel itself runs. It's a restricted area where not even root has access to. But the root user can manipulate some kernel parameters by an interface, provided by the kernel (procfs, sysfs).
System memory is a good example to explicate the difference between kernel and user space. A daemon (that runs in user space) need some memory to run. The kernel manages all the memory that is available. The daemon gets some "virtual memory" from the kernel, where the daemon is not aware of whether it's physical memory or swap space or whatever. The kernel is the one that determines which kind of memory the process gets. Because memory management happens in the kernel space. Other things that happen in the kernel space are process scheduling, inter-process communication, memory protection and management, system calls...

What exactly is userland?

So, userland is what the daemon does (or can do) when interacting with the operating systems ressouces (I/O, network, memory, cpu time). Those ressources are hidden from the process in the kernel space.
The short answer:
It's what the cockpit of a plane for the pilot is.
Comment: Your plane analogy doesn't quite work. A cockpit may be complex but it gives direct access to flight controls with (usually) no abstraction to the pilot.
Comment: You say, "[kernel space] … is a restricted area where not even root has access to [sic]. But the root user can manipulate some kernel parameters by an interface …" In fact, non-root processes can ask the kernel to modify information held in kernel memory; e.g., changing the process's own umask and working directory, or sending a message into a message queue (or, arguably, writing to a pipe).
Comment: and, root can load kernel modules, should you be on a kernel that is modular.
Comment: Memory protection doesn't happen "in" kernel space, it happens in hardware. The kernel can react to a memory protection fault by taking some action, but it's not the kernel that is responsible for the memory protection. (That the kernel has access to all memory is a different matter. In a microkernel, only the "core" kernel will be running in ring 0 and thus have access to all memory; in a microkernel architecture, kernel services often run in userland and thus do not have access to any memory not their own aside from through defined kernel interfaces.)
Answer: You already got several good answers, but I think there's also value in a short and concise answer:
Modern CPUs allow to restrict what specific code is allowed to do. "Kernel mode" refers to unrestricted code with full access to the hardware. "Userland" is code with restricted permissions. If userland code wants to access anything but its own memory, it has to call the kernel, which then checks permissions before performing the requested action.
Answer: Various layers within Linux, also showing separation between the userland and kernel space
for full image
Source
Answer: At first I will agree that there are here many great answers.
 My contribution will be the shortest definition I found years ago about the kernel in a Linux system administration book: "kernel: the memory resident part of the os".


logic native plugins

Question: i own the complete waves plugins bundle, including some other top-shelf plugins. as much as i love Waves and cannot imagine a workflow without them, i find myself quite a lot using the straight-forward, basic native Logic plugins... especially the compressor, limiter and EQ. am i insane?
Answer: No, you are not insane, I think Logic comes with a large amount of excellent plugins and instruments that stand up well to software far above its price range. Since the price drop a few years ago I think that Logic Studio has to be the best DAW in terms of value for money.
Comment: +1 on bang for your buck from Logic. I personally don't find it the most inspirational environment for composing. I just feel like it does things in a very 1998 way. Then again, I'm a weirdo and prefer to do everything in Audiomulch so take that with a grain of salt. :)

Some of the instruments and effects in Logic are drop dead awesome.
Answer: Whatever works and sounds good is good!
I've often found myself using Logic's compressor over many of the Waves/other plugins. There's nothing wrong. It's all about the sound you are looking for.
Answer: I prefer Logic plugins for Sound Design cause I think they give a more "flat" processing. Waves I always thought give more musicality in their processing!
Also Pro Tools plugins are awesome if you are good with the details!
Answer: I really like the ssl compressor and channels, but what was said before is the truth.  It depends on personal preference and the situation.  A ssl comp would probably not fit a metal mix as well as the logic one, but would be better for jazz rock.  Best to experiment and find what works the best.  Non destructive editing is why digital is great.
Answer: That is probably one of the most common statements about Logic 9 is that the plugins are great.  Other than that people complain about the sound quality in my experience.  I always loved Space Designer but Logic and I got divorced awhile ago, when I found a new woman--Pro Tools.
Answer: This may be a a provoking question, but did you buy all those plugins? (Just curious, because you were asking about pirate samples a while ago)
If I am wrong, I'm sorry about asking.
Comment: no provocation intended :) and yes, i've purchased the complete bundle.
Comment: ok =). So I guess you bought those plugins for a certain reason. EG the Q10 is better than the Logic EQ, since you can do independent L/R EQ adjustments (or M/S ). In my opinion most of those plugins advantages is not 100% about the actual sound of it, but about the handling of the plugin ( for example those ONE Knob plugins by waves.)

logic native plugins


Is sending LinkedIn invitation to top management team a good idea?

Question: Recently I completed my internship at a firm and I was wondering whether it's a good idea to send invitation to connect on linkedIn to the top management including CEO? Or should I send request to only people who I worked directly with? The only interaction I had with top management was I made a 1 minute presentation about the internship that's it.
Comment: Note the country here.  I am sure there are cultural differences between countries on this practice.  I am hesitant to respond not knowing how these relationships work in India.  In the US it is a mixed bag and highly dependent on the person.
Answer: Use the Add Note feature when sending a request. Keep it short and simple. The message can vary for person to person, but you should state your intent about wishing to connect.
If you simply send connection requests, some may accept, some may ignore and some may mark your request as "I don't know this person". If a lot of people choose the last option, you risk getting marked as spammer and getting your account suspended.
Answer: Why not?   Worst that can happen is they ignore or decline your invitation.    I'm connected to lots of people on Linked In that I haven't talked to in years,some I've spoken to, but only know through another connection.
Comment: He's leaving the company.  Not like he'll be fired for it.
Comment: This is a bad idea IMO.  If someone that I don't know attempts to connect with me on LinkedIn I mark them as "I don't know this person".  I also remember them.  LinkedIn is a professional network, and typically you need to at least have had a conversation with them. FWIW
Comment: If enough people mark the *I don't know this person* requests from you, you'll be flagged as a spammer potentially by LinkedIn.
Answer: I wouldn't do that. It makes you look really presumptuous. Unless you worked closely with them or are on 1st name terms (i.e. they know you beyond just "this year's intern").

should I send request to only people who I worked directly with?

I've always stuck to this policy and only added C-level (CTO etc) people that I personally know who have made the request of me.
Answer:
Is sending LinkedIn invitation to top management team a good idea?

If your presentation to management was relatively recent, you could still send invitations with a note thanking them for attending your presentation, so they have some context.
A good strategy in general, for timing a LinkedIn invite, is to send one right after you've had an interaction.
Your LinkedIn network is more powerful and relevant when you add people you personally know or have worked with.
In general though, adding top management for its own sake is counterproductive, and adds more noise to your network. It can also be awkward if shared contacts assume you know them personally.
Comment: Excellent answer, the key here is **after** you have had an interaction with the individual, not just *spamming* people.


See all notes on iOS9

Question: After the update to iOS9 which allowed notes to be in rich text, only the notes "on my iPhone" were converted to this new format. The notes associated with my gmail weren't. Before the upgrade, I could lump all notes together in one list so I didn't even need to worry where they were being stored. But now it looks like half the lists I use frequently are on my iPhone, and half are associated with my gmail. Is there a way in iOS9 I can put them all back in one list (e.g. see all)? Or even just convert all the plaintext gmail notes over to the new style?
Comment: I have the same issue, which is of course how I got here. I'd like a way to go back to the previous notes. I don't want any of the new features and the split folders is just plain annoying. Sigh.
Comment: @sdjuan not sure if this is also valid if you're not on iCloud Notes, but there's a toggle in `Settings → Notes` that says '"On My iPhone" Account' which should allow you to save everything into your preferred account by toggling it OFF.
Answer: If you want the new style, then you need to put your notes into the iCloud Notes account, because it is a must that the server support this rich text format.
Answer: I found that you can move them all together on your phone by clicking edit and on the bottom left there is a Move All link. From each folder you can then move to the folder on your phone so they are all together. Sadly it does not allow you to move from the phone to say gmail, icloud or exchange notes but you can move those all onto your phone in the same folder. That's not what I want but hey at least it gets them together.
UPDATE: Although already on iOS 9 the above was before I upgraded to the new notes. Once on the new notes the move from my phone to icloud seems to have just made a copy as now I have them in both places. I actually wanted to move them all to my exchange account but that iss not an option. OK that is a glith in iOS 9 it just looked as if it was on both by the number of notes shown. When I went into the phone notes they were then empty and on exit from there the number dropped to zero. Still no way to move to exchnage or gmail but you can at least move everything to the cloud or the phone. Those seem to be your two options to have everything together.

See all notes on iOS9


Vehicle Permit at the Mexican Border without owner present

Question: I will be getting a Temporary Vehicle Permit for my dad online and he will have the permit on the vehicle.  My question is do I need to be there will him when he crosses the border?
Comment: Are you referring to a Temporary Import Permit (TIP) to take your vehicle into Mexico?
Comment: From u.s. to Mexico and yes a TIP
Answer: You do not need to accompany your father, and your vehicle, into Mexico, but you will need to document that he has your permission to take your car out of the US.

Customs and Border Protection (CBP) has treaties with Canada and Mexico to prevent the import/export of stolen vehicles.
In order to enforce these treaties, CBP Officers might ask to see documentation that the driver of a vehicle leaving or entering the U.S. is either the lawful owner or authorized driver of that vehicle.
If the car or vehicle is loaned or being brought into or taken out the United States on behalf of a friend or relative, the driver might want to have a notarized copy of a permission letter addressed to the "Officer In Charge of Customs and Border Protection" to drive the car across the border.

In addition to the TIP, he needs the vehicle registration (don't leave it in the car) and proof of insurance that is valid in Mexico. Having photocopies of these documents is a good idea. And, should you have a loan (or lease) on your car, you need an affidavit from any lien holders authorizing temporary importation.
Comment: The car is in his name he just needs me to get a permit for him.
Comment: Even better; no problem; he still has to stop after entering Mexico, but won't need the vehicle title. He will need everything else, of course, so you may want to give him the same checklist you'll need for the online process.