Can deleted answers be hidden by default with something to click to show them?

Question: Usually deleted answers are not particularly useful, which is why they were deleted.  If they were hidden (compacted to the first line) by default with a JS [+] to expand them there would be less noise for 10K users.
Comment: I'd recommend people should have to "opt-in" via a checkbox that appears on their preferences tab.  That way you could set your default and not have to open or close the `[+]` all the time if its default state isn't to your liking.
Comment: If no one has made a GreaseMonkey script for this already, it probably wouldn't take much to make one.
Comment: I'll happily make you a greasemonkey script... first you just need to go to my SO profile & upvote everything I've posted until I reach 10k so I can test it properly.
Answer: I however agree that deleted answers only adds noise. As you see in the Related list on the right column, the same problem was discussed before a lot times. Either by removing them from the view, or just pushing them to the entire bottom. Most of those questions got a lot of votes, so there's certainly support from the community.
Bill made a very good point in his comment: make it a preference. The <10K users already don't see them, so this logic is already implemented in the business/view side. Implementing an extra preference seems little effort for the dev team and big favour for the >10K community.
I personally, however, got used to them. I just scoll ahead. But I can find myself in your problem when I went over 10K some months ago.
Answer: I kind of like seeing the deleted answers, sometimes they're interesting to read and I think if there were a method of expansion I'd be frustrated at having to expand them all the time just to satisfy my own curiosity/nosiness.
The deleted answers are well highlighted, the different colour makes it easy to differentiate between answers worth reading and answers you don't need to bother with.
For those reasons I disagree (-1).


Why did the 11th Doctor hate the War Doctor?

Question: So the Doctor of War broke the promise, because he joined the Time War, but why did the 11th Doctor hate him so much for it until Day of the Doctor?
Comment: I'm not sure why this question was closed. It may be obvious to dedicated fans of the show, but it's eminently answerable based on quotes from *Time of the Doctor*, *Day of the Doctor*, *Night of the Doctor*, and some analysis of the Doctor's character. I've reopened it and may post an answer later if nobody else gets there first.
Comment: @Randal'Thor - I voted to close it because I didn't think it was especially clear what OP was asking. Are they wanting to know what about the War Doctor's actions made the 11th Doctor angry or why the 11th Doctor (having previously *been* the War Doctor) couldn't understand their choices.
Answer: Not only did the War Doctor join the Time War, he finished the Time War by detonating The Moment and wiping out both Daleks and Time Lords.
Or at least that's what he thought, after he regenerated into the Ninth, then Tenth, and Eleventh Doctors. He went for most of his next 3 regenerations actually believing he was guilty of genocide, which broke the promise he made to himself when he chose the name The Doctor.
From The Name of The Doctor Script:

DOCTOR: Look, my name, my real name, that is not the point. The name I chose is the Doctor. The name you choose, it's like, it's like a promise you make. He's the one who broke the promise.
WAR DOCTOR: What I did, I did without choice.
DOCTOR: I know.
WAR DOCTOR: In the name of peace and sanity.
DOCTOR: But not in the name of the Doctor.

From the Day of The Doctor script (I'm writing this from memory, as I've seen it more than 10 times. There could still be mistakes but the message is the same):

CLARA: You told me the name you chose was a promise. What was the promise?
TENTH DOCTOR: Never cruel or cowardly.
WAR DOCTOR: Never give up. Never give in.

Clearly, even though they're the same person, The Eleventh Doctor (and also the Tenth and probably the Ninth) had no choice but to hate the man they were before. We all have regrets, things we wish we could take back, and that was the reason. Only difference is The Doctor being a time traveling alien, actually had the chance to go back and undo his biggest regret.
Answer: Because each doctor even though they are the same have quite different personalities and also being a byproduct of regeneration
There are things the thirteenth doctor would never do that the tenth doctor did
There are things the eighth doctor for example did during the time war that led to the actual creation of the war doctor that all the doctors would hate
The ninth and fourth doctors despised the daleks yet the tenth doctor, the twelfth doctor, the seventh doctor, thirteenth and the eleventh would reason with them with during the building of the empire state building Ten asked the daleks to stop and choose peace meanwhile the fourth and the ninth would try to kill them all and of course the ninth because of the time war wanted to kill them even more and the other doctors dont seem to mind too much either way
Comment: Welcome to SFF! Your first answer here, the Harry Potter one, includes evidence within it to back up your theory. This one here though seems like it needs some quotes or something to back it up. Could you [edit] any in? You have what looks like it could be a good answer but it just needs that little bit more in my opinion!


How to enable support of CPU virtualization on Packard bell(AMD Quad-Core Processor A4-5000)

Question: if a computer CPU doesnt support virtualization(such as AMD Quad-Core Processor A4-5000),is it need to buy new pc  to virtualization?or are there other solutions especially software?
Answer: You may need to enter to the BIOS menu into your PC and enable the virtualization since according to this page http://www.cpu-world.com/CPUs/Jaguar/AMD-A4-Series%20A4-5000.html your CPU AMD supports it.
Here is a guide for how to do that.
Hope this helps


What is the main noise in a helicopter flying by?

Question: If you were to stop the tail rotor blades in forward flight, and presuming the vertical fin could maintain sufficient yaw control, would the noise footprint of the entire helicopter, as heard from the ground, be significantly reduced?
Comment: You are hearing the nominal pressure flux of the blades rotation. That is a set density will be projected through the blades at a density proportional to their rotation. The denomination is the pressure differential you hear as sound, and arises from the bulk modulus.
Answer: The short answer is Yes.
Long answer:
During forward flight Helicopter noise is created by a number of processes.

Thickness noise
Low-frequency harmonic force noise
High-speed Impulsive (HSI) noise
Blade-Vortex Interaction (BVI) noise
Broadband noise

Thickness noise is proportional to the maximum flux of fluid displaced by the blade section, so the main rotor (thicker) is more powerful than the tail rotor (thinner). Likewise, the low-frequency harmonic force noise is proportional to the low-frequency air loads on the rotor that produce lift. (The main rotor is also bigger in this case).
This being said, the main rotor generally produces energy with frequencies from ~10 - 100 Hz, which humans are generally poor at hearing. The tail rotor produces energy from ~60 - 400 Hz, which we are considerably better at hearing.
All of this is to say that stopping the tail rotor, though less of a decrease in energy than stopping the main rotor, is actually more likely to make the event quieter. In fact, many noise mitigations are based on tail-rotor noise, such as the NOTAR or a shrouded tail rotor both minimize such noise. (And also HSI and BVI noise.)
[Much of the information shared here is based off of Harvey Hubbard's "Aeroacoustics of Flight Vehicles, Theory and Practice: Volume 1 Noise Sources"]


How do I stream audio from Android to Windows 8 over bluetooth?

Question: I'm trying to find a way to stream audio from my Samsung Galaxy S3 to my Windows 8 Laptop using bluetooth. The devices are paired, but I cannot find a way to stream music. Is it even possible?
Comment: I think it's a windows thing, I mentioned the phone type just in case it mattered, but I don't think it does.
Comment: I've decided to keep this question here, but if you'd like it migrated to [android.SE], please let me know. I guess it would be equally on-topic there (although it's more of a Windows issue anyway).
Comment: What make is your Windows bluetooth adapter?
Comment: @harrymc Let's go with a "Broadcom BCM20702 Bluetooth 4.0 USB Device".  It's popular. :) Since it's a BT 4.0 device it should support most/all the options...
Comment: Close @Ƭᴇcʜιᴇ007 it's BCM2070 3.0 + HS
Answer: On my computers (both windows 7 and windows 8 and Galaxy S3) it's done the same way:

Turn on Bluetooth on both devices
Pair devices
Allow Windows to install all sorts of drivers for the phone
Connect devices via Bluetooth (you can do it on both S3 and Windows). I can't remember what exactly was it on windows 8, but Windows 7 has a nice button "Connect" with description next to it saying "Listen to audio from your phone through this computer's speakers".
Small window pops up on which I can control the audio (Stop, Play, next, previous) with name of my S3 in bar on top.

I remember that Windows 8 has almost the same process, but all I have on me right now is Windows 7.
Honestly saying here that I don't know if for windows 8.1 it works the same. But I assume. It's part of the Bluetooth functionality of the Windows, looks like.
My Laptop is Dell Latitude E6400 (oldie but goodie), with Dell drivers for Bluetooth. No additional software was ever needed.
Comment: Somehow, my computer seems to be missing the needed drivers. It finds the phone, but it doesn't play audio. What am I missing?
Comment: You need to obtain those drivers. Sorry for the harsh reply, but that what it amounts to. Assuming you can connect to your computer simple bluetooth audio device (headphones, BT speaker etc) and they work ok, the drivers is what you need to get.
Answer: Had the same problem here, my PC wouldn't play audio streamed by my Android 5.0 phone. I've reinstalled Bluetooth drivers on my PC and it worked like magic
Comment: Welcome to Super User. Please be aware you have posted an answer to a question that is very old. Although there is nothing wrong with doing so, just be aware you may not get a response.


Applying four colors theorem in polygon map using ArcMap

Question: I need to apply the four colors theorem in a polygonal shape in a way that I do not need to choose manually each color to put in each region. I wish to knows if there is any extension, plug-in, script or data base that may be used with ArcMap and ArcToolbox to do it mathematically or programatically, so I could use it for now on with every map I come to create.
Comment: I posted a suboptimal solution on [GIS](http://gis.stackexchange.com/a/32228) (with working `R` code) and an optimal solution (which will use three or even two colors if they can be found to work) on [Mathematica](http://mathematica.stackexchange.com/questions/19177/strategies-for-solving-problems-involving-searches). That solution is recursive; the [reply to my post](http://mathematica.stackexchange.com/a/19182) gives a linear programming solution.  Manifold GIS has long had a five-color algorithm built in.  (Four-coloring is hard to do; five-coloring is relatively simple to achieve.)
Comment: If you have no "code so far" my ArcGIS for Desktop recommendation would be to start with the [**Polygon Neighbors**](http://resources.arcgis.com/en/help/main/10.2/index.html#//000800000045000000) tool to get a table listing all neighbours of each polygon.
Comment: @PolyGeo: thanks for the tools (I didn't know it) but I could not use it to solve my problem
Comment: This answer shows how to achieve something similar using built-in QGIS Processing tools (doesn't guarantee 4 colours, but you get a small number of non-touching colours which is good enough for me!) https://gis.stackexchange.com/a/295457/
Answer: Unfortunately, the existing tools were not fully compatible with the latest versions of QGIS and ArcGIS. Therefore I made my own solution using the tool indicated by @polygeo, the QGIS plugin from @Alexandre and the name of the algorithm (four color map) from @Jens.
Here is my code for those interested (for ArcMap but the second part could be used in QGIS as well).
arcpy.MakeFeatureLayer_management(fc, fc[:-4]+ "_lyr" )
try:
    arcpy.AddField_management(fc[:-4] + "_lyr", "color", "SHORT")
except:
    print "field alread exists"
arcpy.CalculateField_management(fc[:-4] + "_lyr", "color",  "10" , "PYTHON")

arcpy.PolygonNeighbors_analysis(fc[:-4] + "_lyr", fc[:-4] + "_tb.dbf" )
graph = []
cursor=arcpy.da.SearchCursor( fc[:-4] + "_tb.dbf" , ("src_FID","nbr_FID") )
for row in cursor:
    graph.append(row)

pols = arcpy.da.UpdateCursor(fc[:-4] + "_lyr", ("OID@","color"))
colored = []
for pol in pols:
    nbrs = [ second for first, second in graph if first == pol[0]]
    usedcolors = []
    for nbr in nbrs:
        usedcolors += [second for first, second in colored if first == nbr]
    pol[1]=[color for color in range(10) if color not in usedcolors][0]
    colored.append(pol)
    pols.updateRow(pol)

Note that the algorithm does not guarantee that only 4 colors are used: though it has been proven that the solution exists, the "brute force" is necessary to achieve it. In my case, I got 7 colors which is small enough. The script could have an additional loop until the solution is found, but I need to do it for hundreds of maps and 7 colors is OK.
Comment: This is brilliant - thanks so much for sharing it. I noticed at ArcGIS 10.2 the field names on the PolygonNeighbors output table have changed slightly - the fields are now called _src_OBJECT_ and _nbr_OBJECT_
Comment: As far as I understood, raw force is needed. As mentioned in my post, you must run it several times to have a chance to reach the 4 colours.
Comment: Is this script optimal i.e. does it ensure that a minimum of colors would be used?
Comment: Still works great! Maybe the src_* and nbr_* field names depend on input type. I ran it now with a geodatabase fc input and Desktop 10.5 and they were named src_OBJECTID and nbr_OBJECTID. The script could be adjusted to list the fields that start with src and nbr so input type (or version of ArcGIS) does not matter.
Answer: There is a VB6 developer sample and an ArcGIS 9.x geoprocessing tool but from the comments on this ArcGIS Idea they don't work at 10.0+.
Perhaps someone would be interested in porting it.
A QGIS solution called TopoColour is given in the comments of this related question: Color polygons so each is distinct from its neighbors
Answer: This is an adaptation of @radouxju's answer into a function. It will add a color field to the input feature layer and calculate. It should work regardless of the field name endings of PolygonNeighbors (they seem to be different for different users/inputs/arcgis versions (?))
def color_me(feature_layer):
    import arcpy
    try:
        arcpy.AddField_management(feature_layer, 'color', 'SHORT')
    except:
        print 'Could not add color field. Maybe it already exists?'

    arcpy.CalculateField_management(feature_layer, 'color',  '10' , 'PYTHON')

    arcpy.PolygonNeighbors_analysis(feature_layer, r'in_memory\neighbor_table' )
    graph = []
    neighbor_fields = [f.name for f in arcpy.ListFields(r'in_memory\neighbor_table') if f.name.startswith(('src', 'nbr'))]
    cursor=arcpy.da.SearchCursor(r'in_memory\neighbor_table' , neighbor_fields)
    for row in cursor:
        graph.append(row)

    pols = arcpy.da.UpdateCursor(feature_layer, ('OID@','color'))
    colored = []

    for pol in pols:
        nbrs = [ second for first, second in graph if first == pol[0]]
        usedcolors = []
        for nbr in nbrs:
            usedcolors += [second for first, second in colored if first == nbr]
        pol[1]=[color for color in range(10) if color not in usedcolors][0]
        colored.append(pol)
        pols.updateRow(pol)
    arcpy.Delete_management(r'in_memory\neighbor_table')

Comment: I'm using this now for viewing storm water catchments.  Those can come out as multi-part polys and can have doughnut holes inside each other, and this appears to work well with those too!  it can lead to more colors used, but still perfect for what I need
Answer: If you are using QGIS, I believe that what you need is the Coloring a map plugin.
Unfortunatly, the plugin is only available for QGIS 1.8 version, but you can always download and see how the code works!


Do we create Test classes for the Handlers or just for the Trigger?

Question: Could you please let me know if we create Test classes for Triggers only? or do we create a test class separately for Handlers too?
Answer: Generally speaking, you'll want to have one test class for every artifact.
Have a trigger? Write a test class for it
Have an Apex class? Write a test class for it
Yes, a single test class can give you coverage for multiple artifacts, but smaller, more focused tests are generally easier to write. Ideally, you'd have "unit" tests which stress a single piece of functionality for a single at a time as well as "integration" tests which aim to ensure that the individual units work as expected when they're chained together (i.e. a triggger calls class A, then feeds the output into class B, which then internally calls class C).
Comment: But my seniors are saying for If the class is getting called from Trigger then we should have a test class only for Trigger not for the called Apex class from Trigger. Are they correct?
Comment: @user91530 No, they are not correct (or at the very least they are not giving you the whole story). Writing a test for a trigger here is closer to an integration test. It'll give you coverage for the other classes it ends up executing, but it is harder to set up such a test (because you likely need to insert a bunch of test records prior to executing the trigger, and must perform DML to cause the trigger to execute). As I said, best practice is to have both unit tests (which stress a single part of a single class) and integration tests (which stresses how things work together).
Comment: @user91530 and because I suspect this is an issue too, the main point of unit tests is not to gain code coverage. Unit tests are useful when you use assertions to verify that the code being tested is producing the output you expect. You should also be testing "negative" cases (where the input is not what you expect it to be, e.g. your method takes an `Integer` argument but you get passed a `null`). You can have 100% coverage of a method called `do2Plus2()`, but if it returns 5 (or anything other than 4), it still has a problem that needs to be fixed.
Comment: Thanks Derek for taking time to explain it so patiently. I really appreciate your time and efforts.


Recent horror movie where paranormal researchers prove ghosts exist and are targeted by those very ghosts

Question: I can't remember anything about the movie except glimpses of its trailer, which showed the paranormal researchers getting spooked by their very findings. The movie seems to be quite recent, probably after the year 2005. There was one shot where the actor is sucked in through the wall, by a whitish looking entity. Very spooky. Please tell me the name of this movie.
Answer:
You're probably looking for "The Apparition (2012)".

When frightening events start to occur in their home, young couple
  Kelly and Ben discover they are being haunted by a presence that was
  accidentally conjured during a university parapsychology experiment.
The horrifying apparition feeds on their fear and torments them no
  matter where they try to run.
Their last hope is an expert in the supernatural, but even with his
  help they may already be too late to save themselves from this
  terrifying force.

Watch the trailer to confirm.
Note: The movie "Grave Encounters 2 (2012)" features a similar scene, where a character gets sucked into the wall. But that's more like a turbulent vortex thingy. Also, the scene's not part of the movie trailer.
Answer: Maybe Insidious? I don't want to describe the movie because I'm afraid it will ruin the fun :x but it kinda fits your description.
Comment: At the very least, you should explain what points match up between the movie and the description in the question. As it stands, the only way for them to really figure it out is to either go read up more and be possibly spoiled, or watch the movie. If you lay out the matching points and discrepancies, they may recognize it or be able to safely confirm that it's the wrong movie without having too much spoiled.


The true meaning of Sol regarding time on Mars

Question: I'm writing a story about Mars and I'm really confused as to how one should use the word 'Sol when talking about the passage of time there. For example, Would one say to a colleague: "Today is Sol 345, Jack"
Answer: From the Wikipedia page on Martian timekeeping:

The term sol is used by planetary astronomers to refer to the duration
  of a solar day on Mars.[7] A mean Martian solar day, or "sol", is 24
  hours, 39 minutes, and 35.244 seconds.[6]

"Sol" is often used as a direct replacement for "Day" when concerning Mars. Mission duration for Mars missions is measured in Sols, so saying "Today is Sol xyz" would be normal, but I'm not sure if anyone would say "what a wonderful Sol tomorrow is going to be".
Comment: Sometimes we say "yestersol" and "solmorrow".
Comment: I could imagine some pedantic conversation like: Team leader: "What a wonderful day it is!". Science Advisor: "Don't you mean 'what a wonderful SOL' ?"
Comment: But is Sol global or local on Mars? Does every lander has its own midnight definition? Does it change as a rover moves? On Earth we have a definition of day for each time zone. When the Sun is on the opposite side of Earth, a new day begins. When does a global Sol begin? Are their timezones on Mars? How many, 24.6, or don't you use 12 h watches to keep track of mission time there? @MarkAdler
Comment: "what a wonderful Sol tomorrow is going to be". Funeee:)
Comment: Local.  Each lander has its own "time zone" with noon defined by the local mean solar time at the location of the landing.  It does not change as the rover moves.  (The variations in the true local noon due to the eccentricity of Mars' orbit is much greater than the change due to the trek of the rover.)  There are 24 Mars hours in a Mars solar day, which are used for rover activity planning.  There are no global time zones in use (though I'm sure someone has defined some for fun).
Comment: Since a Moon day is about our month, and a Venus day is about eight of our months, I don't think that we'll find it very useful to have units for those with some sort of analogy to our day.


How should I configure OS for fuzz testing?

Question: Should I configure my OS in any particular way, if I'm going to be doing some fuzz testing?  Should I turn off ASLR (address space randomization)?  Does it matter?
Comment: Are you evaluating the robustness of the OS or something else?
Comment: Oops, sorry about the ambiguity, @this.josh!  I'm evaluating an ordinary user-mode software application.  Many OS's have security settings that can be configured.  Does it matter how I configure the OS that is running the fuzzing environment?  For instance, will enabling security settings help my fuzzer detect more bugs?
Answer: ASLR is a broad term that encompases many different protections and techniques.
In general, basic forms of ASLR (eg stack randomisation) are used to make development of exploits harder or impossible - but do not prevent the triggering of the bug and a crash of an application. Fuzzing should work the same with aslr enabled or not.
Comment: I just figured that by mistake I was referring to GCC's SSP, not PIE, when talking about variable reordering, sorry about that. To answer your question, some bugs are there because of compiler specifics, not from the actual application code itself. To detect these bugs you should fuzz with the settings the application is shipped with, and aslr shouldn't matter (but SSP would)
Answer: Off the top of my head, I don't think aslr will matter much one way or the other - it seems to me that it's more effective at preventing a bug from turning into a vuln. Anytime your fuzzer gets an out-of-range result, you're safest assuming it can be used against you; not sure aslr would change that since there are plenty of ways of getting around it (depending on settings, platform, yada yada).
Anyway, I'd say you should make the system as loose as possible to give your fuzzer the max chance of successfully finding holes - no firewall, high ulimits, plenty of bandwidth, lots of processors if you're on a multithreaded app to maximize the chance of race conditions, etc.
I'd also recommend fuzzing while running on more than one OS, since libraries may behave differently. That particularly goes for Windows, which has lots of good debugging stuff. Don't know much about osx, but if you can get your stuff running there, you're likely to find a substantially different environment.
Please post results - I'm curious to know how this works out.
Answer: I recommend using a fuzzing framework that has a testing harness like the one foudn in Peach Fuzz.  A testing harness will attach a debugger to your target application and keep track of crash reports and what fuzz test case caused it.  When the target application crashes,  the harness will restart the application and continue testing.
ASLR,NX zones, Canaries, heap cookies, ect, ect, ect, will not cause problems with the fuzzing process.  However these will make it very difficult to exploit the memory corruption vulnerability when you find it.


Can downloaded BBC iPlayer content be replayed abroad?

Question: If I have downloaded BBC programmes from iPlayer on to my computer, will the different broadcast standards between the UK and US prevent their being successfully played on a US TV using HDMI?
Comment: What format are the downloaded programmes in? We have to know that, marking this question as 'unclear', please edit to provide lots of detail, thanks.
Comment: Probably your biggest issue is that iplayer downloads are normally only valid for a short period of time before they expire, and you won't be able to re-download when you're outside the UK....
Comment: If I were british would use a VPN with an exit point in the UK and be done with it.
Answer: If you're using the official BBC application to do this, yes, you can watch programs you've already downloaded even when you're overseas. See official guidance:
http://iplayerhelp.external.bbc.co.uk/tv/watch_outside_uk
You cannot download any further programs, and the programs you've downloaded will only remain for 30 days. This is checked via IP. The idea presumably being that a UK resident (with a current TV license) can download shows and watch them while on holiday.
HDMI is just the method by which you connect your TV to your computer, what you see on the TV is a mirror of your computer screen, and there's no difference between UK and US TVs in that way. So if you have a laptop on which a program was downloaded, and you plug it directly into a TV with HDMI to watch, that should work.


Narrow Phonetic Transcription: Stretching?

Question: I use narrow phonetic transcription in my job. The one symbol I need but can't seem to find is a way to mark stretching of the tongue from side to side. Does this exist? I have made up my own, but I'd rather use a standard symbol if possible.
Comment: I work with non-native speakers of American English. For example, in the word "understand," I have a lot of students from China who slightly broaden the tongue (widening toward the side teeth) when producing the first vowel.
Comment: Is this for transcription of disordered speech, or for some other use? Also, by "stretching the tongue from side to side" do you mean flattening/broadening the lamina, wagging the tip left and right, or something else?
Comment: The way I interpreted it at first glance was "stretching" the sides of the tongue so that the air does not escape, as in [d], unlike in [l], but that of course changes the manner of articulation, thus entirely different symbols would have to be employed.
Comment: @Jane Ah, so flattening the lamina?
Comment: I think widening/broadening probably describes it best, but I think we are talking about the same thing.
Comment: @Jane Doesn't broadening the tongue during a vowel result in a change in the quality of the vowel too? In my attempt broadening the tongue while pronouncing /ʌ/ makes it sound more like [æ].
Comment: Great question. The problem is that for my students, it doesn't fully shift it to another vowel; it is just a slightly distorted version of what the vowel should be. This happens with other vowels as well. For example, the /oʊ/ sound may be produced with less gliding of the lips than we expect to hear in American English, or with the tongue in a slightly lower position than we would expect, but not enough that the vowel is heard as a completely different vowel sound.
Answer: It's not clear what you mean by "stretching the tongue from side to side". You can do that with your fingers (if you have a dry tongue), but otherwise it's not possible -- the tongue doesn't stretch that way. There is no symbol to denote this, since the situation you're describing does not exist. Presumably you mean something else -- we'd have to know what you're referring to.
Based on the comments, it appears that the question is about laminal sounds, which are notated with the diacritic ̻ . Although it is usually added to consonants, nothing in principle prevents using it on a vowel. The Tarama variety of Miyako Ryukyuan is said to have such vowels, and perhaps some Wu varieties of Chinese have them.
Comment: This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - [From Review](/review/low-quality-posts/23266)
Comment: This should be a comment ...
Comment: @jknappen, The question asks "Does this exist?"  The answer is "No."  I don't see a problem with this answer.
Answer: To my knowledge there is no official (or even conventional) symbol to describe that gesture. If I had to pick a symbol to describe "tongue spreading", I might pick U+20E1: combining left-right arrow above. Here it is on a schwa: ə⃡
I would choose that because U+034D (combining left-right arrow below) is used in the IPA extension for disordered speech to describe lip spreading, so there's a natural parallel there.
Comment: U+20E1 is "COMBINING LEFT RIGHT ARROW ABOVE", not below, i.e. the superior version of U+034D. I wouldn't use it to describe a lingual gesture precisely because the inferior version is used to denote lip spreading in extIPA.
Comment: @Nardog thanks for catching the above/below typo, I've corrected it. Not sure I understand your objection though: lots of diacritics have different semantics when superior vs. inferior; extIPA even seems to do this quasi-systematically (e.g. superior/inferior combining "bridge" indicating involvement of upper/lower teeth, respectively).
Comment: I'm having trouble seeing the symbols in your responses (I'm sure it's a problem on my end), but I was able to look up the codes. Thanks so much for the description and information. U+20E1 is exactly what I'm using! Do you have any sites I can look at with more detailed information on diacritics?
Comment: @Jane I use https://r12a.github.io/pickers/ipa/ a lot. Aside from the click-copy-paste functionality, note the tools in the upper right (esp. "show codepoints") and at the bottom ("add code points" and "search for"). If you're looking for *usage* information, though, it won't help.


Heston Discretization dt

Question: I'm trying to figure out the discretization of the Heston model. In the choice of dt, I have seen several ways that people specify this number. Would it not just be 1/n where n is the number time steps? And the paper mentions that the wiener processes should be normally distributed with variance dt, but I often don't see that mentioned and implementations seem to leave that out a lot. If using dt = 0.04, that sounds like a very small variance. Is that correct?
Comment: The size of a time step $dt$ should be as a big as possible (to reduce computational burden) but as small as possible (to reduce the scheme-dependent discrétisation bias). The variance of the increment of a Brownian driver is indeed $dt$ over that interval. But the instantaneous variance of $S_t$ (resp. $v_t$) over $dt$ is given by $v_t dt$ (resp. $\sigma \sqrr{v_t}$)
Answer: I would like to point out some things that might be helpful.

I'm trying to figure out the discretization of the Heston model. In the choice of dt ...

There exists many discretization schemes that could be implemented to simulate a system of stochastic differential equations (SDEs), such as the Heston model. One of them is the EulerMaruyama scheme, which has a $\frac{1}{2}$ strong order or $1$ weak order of convergence. I believe you are referring to this particular scheme.
The Heston model is given by:
\begin{aligned}
  dS(t) &= r \cdot S(t) \cdot dt + \sqrt{v(t)} \cdot S(t) \cdot dW(t), \\
  dv(t) &= \kappa \cdot \left( \theta - v(t) \right) \cdot dt + \sqrt{v(t)} \cdot dZ(t)
\end{aligned}
with:
\begin{aligned}
  S(0) &= S_0, \\
  v(0) &= v_0, \\
  \langle dW(t), dZ(t) \rangle &= \rho \cdot dt.
\end{aligned}
It is important to note that this system of SDEs has actually non-diagonal noise, since diffusion of the stock price dynamics has a non-null derivative with respect to the variance $v(t)$. This has an important impact in which discretization schemes can be applied. Fortunately, the EulerMaruyama is still aplicable in systems with non-diagonal noise. On the contrary, the EulerMaruyama may need more simulation paths and smaller $dt$ than other schemes in order to achieve convergence when pricing an option. I would recommend reading "Numerical Solution of Stochastic Differential Equations" from Kloeden and Platen to get more insight about the discretization schemes for SDEs.

Would it not just be 1/n where n is the number time steps?

Yes, of course: if n is the number of steps per year, you can either specify n and compute dt or specify dt and compute n. The problem is different: which n or dt should I select for my simulation?
In my opinion, the best way to figure out this is by conducting an analysis of the following aspects:

For a System of SDEs with analytical solution, which $dt$ and $N$ (number of trajectories or paths) should I use in order to achieve convergence.

You can compute the price of a derivative numerically (varying $dt$ and $N$) and analytically and check when you achieve convergence (the frontier of convergence).

Check the cost-benefit of increasing trials, diminishing the time step and their consequences on the computational time.

Many other tests can be included, these are just a couple of them. Also, there are discretization schemes that use adaptive time steps! You can think about them by making a comparison with ODE solvers with adaptive time steps.
Hope it helps!
Comment: The problem that I am seeing mostly is that the choice of `dt` affects where the paths converge. Convergence isn't that big of an issue because I can always add more paths. But what choice of `dt` would give a more accurate convergence? It seems that depending on the way you look at it, `dt` could be the total number of steps or the number of steps annually. Say that I have 365 steps per year and the simulation is over 2 years, should `dt` equal $\frac{1}{365}$ or $\frac{1}{730}$?

Heston Discretization dt


IBM x3550 Unrecognised progress code

Question: I have an x3550 M4 in our lab that will not boot past the 'System Initializing...' message. This happened after a power loss. I unplugged for an extended period and have removed/reseated the two different kinds of memory and each of the two CPUs one at a time and an installed memory cache. One thing I'm noticing is the 'Light Path Diagnostics' panel never lights at all where normally a blue 'i' light, only the green power light on the panel works fine. I did push the reset button. The panel cable does have a crease in one spot where rubbed against the frame, but does not look cut.
The memory cache has lit green light. The four board lights behind the power supply show solid green for PWR, slow blinking green light for RTMM Heartbeat, a rapid blinking green light for IMM2 Heartbeat while connected cable to IMM2 port not lit and no light on SYS BRD ERR light. The IMM2 is configured and not responding. The error displayed is:
(0x 2) Unrecognised progress code

What would be my next steps to diagnose this issue? I cannot seem to find an official diagnostics CD or other downloads.
Answer: Forgot about the CMOS battery. After pulling for several minutes and put back, the system is booting. All okay.

IBM x3550 Unrecognised progress code


object reference not set to an instance of object

Question: I have been getting an error in VB .Net

object reference not set to an instance of object.

Can you tell me what are the causes of this error ?
Comment: post the code so we're not shooting in the dark; or at least describe what's going on!
Comment: it would be good if you can post your code file that generates this error
Comment: please add your code
Answer: The object has not been initialized before use.
At the top of your code file type:
Option Strict On
Option Explicit On

Comment: Option Explicit, for those who may not know, forces declaration of variables.  This means that if you fat-finger a variable name, the compiler will not assume you intended to create another variable, and it will complain.  Option Strict means that if you want the type of a variable translated, then you'll do it manually.
Answer: Let's deconstruct the error message.
"object reference" means a variable you used in your code which referenced an object.  The object variable could have been declared by you the or it you might just be using a variable declared inside another object.
"instance of object"  Means that the object is blank (or in VB speak, "Nothing").  When you are dealing with object variables, you have to create an instance of that object before referencing it.
"not set to an " means that you tried to access an object, but there was nothing inside of it for the computer to access.
If you create a variable like
Dim aPerson as PersonClass

All you have done was tell the compiler that aPerson will represent a person, but not what person.
You can create a blank copy of the object by using the "New" keyword.  For example
Dim aPerson as New PersonClass

If you want to be able to test to see if the object is "nothing" by
If aPerson Is Nothing Then
    aPerson = New PersonClass
End If

Hope that helps!
Answer: sef,
If the problem is with Database return results, I presume it is in this scenario:
   dsData = getSQLData(conn,sql, blah,blah....)
   dt = dsData.Tables(0)  'Perhaps the obj ref not set is occurring here

To fix that:
  dsData = getSQLData(conn,sql, blah,blah....)
   If dsData.Tables.Count = 0 Then Exit Sub
   dt = dsData.Tables(0)  'Perhaps the obj ref not set is occurring here

edit: added code formatting tags ...
Comment: You may want to use the code formatting tags for this answer.
Answer: In general, under the .NET runtime, such a thing happens whenever a variable that's unassigned or assigned the value Nothing (in VB.Net, null in C#) is dereferenced.
Option Strict On and Option Explicit On will help detect instances where this may occur, but it's possible to get a null/Nothing from another function call:
Dim someString As String = someFunctionReturningString();
If ( someString Is Nothing ) Then
   Sysm.Console.WriteLine(someString.Length); // will throw the NullReferenceException
End If

and the NullReferenceException is the source of the "object reference not set to an instance of an object".
Answer: And if you think it's occuring when no data is returned from a database query then maybe you should test the result before doing an operation on it?
Dim result As String = SqlCommand.ExecuteScalar()   'just for scope'
If result Is Nothing OrElse IsDBNull(result) Then
    'no result!'
End If

Answer: You can put a logging mechanism in your application so you can isolate the cause of the error.  An Exception object has the StackTrace property which is a string that describes the contents of the call stack, with the most recent method call appearing first. By looking at it, you'll have more details on what might be causing the exception.
Answer: When working with databases, you can get this error when you try to get a value form a field or row which doesn't exist. i.e. if you're using datasets and you use:
Dim objDt as DataTable = objDs.Tables("tablename")

you get the object "reference not set to an instance of object" if tablename doesn't exists in the Dataset. The same for rows or fields in the datasets.
Answer: Well, Error is explaining itself. Since You haven't provided any code sample, we can only say somewhere in your code, you are using a Null object for some task. I got same Error for below code sample.
Dim cmd As IDbCommand
cmd.Parameters.Clear()

As You can see I am going to Clear a Null Object. For that, I'm getting Error

"object reference not set to an instance of an object"

Check your code for such code in your code. Since you haven't given code example we can't highlight the code :)
Answer: In case you have a class property , and multiple constructors, you must initialize the property in all constructors.


How does a magnetic field "push" charges?

Question: I was under the assumption that a magnetic field acts similar to that of the normal force in mechanics; both affect the path of the object, but do no work. So now suppose that we have a rectangular circuit with the left side in an uniform magnetic field that is pointing towards the computer screen and the right side being moved at a velocity $v$ Since the whole circuit is moving with a velocity $v$ there is a magnetic force perpendicular to $v$, but still in the direction of the wire. Therefore the magnetic field pushes the charges along. If we assume the charges to be that of protons and electrons, the magnetic field will separate electrons from protons and cause current to flow. My confusion is on the very fact that the magnetic field is causing the current to flow. I simply thought the magnetic field would change the direction of current flow. How can this be?
Comment: Magnetic fields do no work in free space, but an electron (e.g.) redirected such that it hits the surface of the wire will transfer momentum.  Or maybe you're asking how a magnetic field induces current, in which case a *varying* field is required.
Comment: @CarlWitthoft A varying field induces electric field which can contribute to an emf.  But time varying fields are not required to generate an emf when a circuit is moving.  Though you are correct in the sense that an emf is different than work.
Comment: @carlwitthoft So one needs a varying magnetic field and an external force to make the magnetic field change?
Answer: Magnetism arises from the continuous movement or spin of electric charges. Therefore magnetism does affect electric charges not only of direction but also pulling them to move the same way the electrons causing the magnetic field are and mostly to spin the same way.
Answer: Without the magnetic field the velocity of electrons is v. When the magnetic field is on, the velocity of electrons is v + u.
Velocity and kinetic energy of electrons increases when the wire enters magnetic field. The source of that energy is the force that pushes the electrons to the direction of the velocity vector v.
Electrons in a magnetic field would move around in a circle whose center is at rest relative to to the magnet. But in this case electrons are trapped in a tube that keeps moving on. That tube pushes the electrons in addition to the magnetic field that pushes the electrons to direction perpendicular to vector v + u .


Sharepoint Hosted app update issue

Question: I have deployed my hosted app in test site environment with version 22.214.171.124 In the same version I have one list named Employee. Now I renamed the list name as Employees raise the version 22.214.171.124 and updated the app in same test site environment.
The issue now I am facing is that in updated app there are two lists present named Employee and Employees. I don't understand why this is happening. Suggest some help.
Answer: Your App/Addin upgrade won't wipe out any app web content, that's reason why you still see the Employee list. You might need to retract the app and install again if you want a fresh start on app web contents.
Comment: This solution is not workable in live environment (Client Context) where you already have data in the lists

Sharepoint Hosted app update issue


According to the Church of God (Cleveland), are children sin-free?

Question: I work with children in a day care that is part of the Church of God.  Naturally, all of the employees except me are of the Church of God, which is fine by me.  I am non-denom.  I find it curious that one of my co-workers stated that the children in my toddlers and twos class are "sin-free."  I feel a bit odd asking anyone there about it since they are all COG.  I don't understand how a human born of Adam and fallen short of the glory of God could be free from sin.  I understand there is an age of accountability around 12 or 13, but does the COG teach that young children are "sin-free"?
Comment: You can easily answer that by looking for children that don't sin... I'm surprised your co-worker can conclude that when working with children.
Comment: I agree.  No one teaches them to scream NO! or hit each other or take toys and watch for a reaction just for spite.  It's all pre-programmed.
Comment: Yours is a perfectly good question if put this way: How does the COG explain that young children are "sin-free"? If you revise your question thus, it can be taken off hold.
Comment: What does the CoG teach regarding "original sin"?  Per WIKIPEDIA: "Original Sin of Depravity- the church believes that original sin or depravity is that corruption of the nature of all the offsprings of Adam by reason of which everyone is very far gone from original righteousness or the pure state of our first parents at the time of their creation, is averse to God, is without spiritual life and inclined to evil, and that it continues to exist with the new life of the regenerate until eradicated by the baptism of the Holy Spirit."  Therefore, they are not "sin free".
Comment: Per [CoG Site](http://www.churchofgod.org/resolutions/children-and-youth-1998) "All children and youth are a heritage of the Lord (Psalm 127:3, NKJV), to be cherished, protected, defended, redeemed, and discipled."  Nothing about children being "sin free".
Answer: The Church of God by Faith (not sure if there is a distinction like there is between Churches of Christ) does officially hold to original sin. However, many individual members of all denominations have *'s on that doctrine, if not outright reject it. One of the *'s being  an age of accountability that you mentioned, before which salvation is given without formal repentance, baptism, and so on depending on denomination. For example, many hold that an aborted baby would go to heaven irrespective of the guilt they believe comes by way of original sin.
(As an addition, the doctrine of original sin doesn't come from passages about or addressing the theology of the actual original sin of Adam and Eve. Rather it comes from passages that are poetic in form and are in the context of repenting in extremely serious circumstances. I.E. Psalm 51, where David has been convicted of adultery and murder and is about to face strong consequences. As such, the doctrine of guilt at birth is justifiably debated among believers).


Self Contained Pinax Project

Question: I cloned a basic project. I was wondering which files do i have to copy so it becomes a completely self-contained project? I am referring to the css files, the templates, other apps?
Also, where will these files be located.
Answer: It depends on the layout of the Django project, but these are usually the basic files of a project.

settings.py
manage.py
urls.py

By going into urls.py, you will be able to see their their views are coming from, and those files should also be include. From the views, see what they import, and so on and so fourth until you reach the template files.

Self Contained Pinax Project


Xcode auto-quit in Mountain Lion

Question: On Lion, Xcode quit on its own when it was downloading documentation with no windows open. Is it safe to have Xcode download documentation in Mountain Lion or will it still quit on its own if all windows are closed?
Comment: one thing to be clear about  is that its not Xcode that is quitting itself. Its OS X that is quitting Xcode.
Comment: Auto termination is dependent on how Xcode indicates its status to OS X, which is Xcode version depended if there were changes made, which version of Xcode is this about? An Xcode version that auto terminates on Lion should also auto terminate on Mountain Lion.
Answer: According to OS X Daily, you can disable auto-terminate in Lion and Mountain Lion with the following terminal command:
defaults write -g NSDisableAutomaticTermination -bool yes

This sets the NSDisableAutomaticTermination flag in the defaults database that OS X consults to get various settings.
Note that this will disable automatic termination for all applications, not just Xcode.
Comment: Accepting MrDaniel's answer (because it was the answer) and upvoting this one because it tells me how to disable that stupid functionality. Ta!
Answer: OS X 10.8.1 no longer automatically terminates Xcode 4.4.1 while Xcode is downloading documentation with no windows open. It looks like "they fixed the glitch" of Xcode not properly communicating its "working" status to OS X. Have not tried on Lion, but I would guess that Xcode 4.4.1 no longer is auto-terminated there too when  downloading documentation.

Xcode auto-quit in Mountain Lion


Data Storage in mongodb vs RDBMS?

Question: I have read that mongodb memory maps all the data to RAM or main memory. That is all reads and write are directed to the RAM. And after every 100ms or so, is written to the disk. But even RDBMS uses pages of size 8KB and does the same. SO why do people consider memory mapped files and mongo as an advantage over RDBMS. I am not debating about other features of RDBMS vs mongo just this one storage feature.
Answer:
Why do people consider memory mapped files and mongo as an advantage over RDBMS?

Having your database tables in memory allows for much faster read access.  Writes are also much faster because writes can be batched and postponed for when the database becomes idle.
A disk based relational database will use a memory cache so that repetitive calls for data will access the cache rather than the disk.  However, most databases are much larger than the cache size.
You use a relational database to store relational data.  You use a noSQL database like MongoDB to store non relational data, like documents.
There are relational database engines like HSQLDB that will map all of the database tables to memory.

Data Storage in mongodb vs RDBMS?


Coordinates of the segments of the hair particle

Question: All Hair Particles are based on Vertices. I activated the option in ParticleSystem "Advanced" and switched to Verts. A hair has 4 segments. I would like to read these segments per hair as coordinates. How does that look in Python?
Answer: what is your level in Python? I mean are you able to reproduce code from Blender if this need?
I could share with you an approach for this, but more like workaround instead of direct solution,... because I can't understand the main purpose of your question.
What I understood, is that you want to control a particle hair system resolution, emitted trough vertices ...

Or you can only use the Sphere to control, removing  the previous script note property.

Hope this will help you!


Applying Autotune to a Video

Question: I would like to auto-tune a video, but I do not know how. Please tell me how I can achieve that effect.
Comment: Could you be a little more specific on what exactly you want to do to the video? Align all frequencies to one note and its octaves? Tune to a certain scale or other set of frequencies? Just manipulate certain specific elements?
Answer: 1: Export the audio, you want the audio exclusively, and you want it in lossless format (wav, aiff, flac) (unless your DAW in the next step supports video). You might need a video editing tool for this one.
2: Import the audio to a DAW: protools, live, logic, nuendo, whatever.
3: Apply auto-tune.
4: If your DAW can't deal with video, you need to glue back the video and audio using a video editing tool.
The question is very board as is though, so it's hard to help you further.
Or perhaps there's a video editing tool that supports audio plugins? If this is the case, you just have to load autotune (or other pitch corrector) into the video editing tool and you are done!
Comment: Let's hope it's not polyphonic ;-) I'm not envisioning anyone learning Melodyne in an afternoon ;)
Comment: Might be worth mentioning that, if the file contains multiple tracks, or some encoded 5.1 type sound, there may be a bit more work involved in dealing with the audio.
Comment: @Tetsujin I haven't tried polyphonic features of pitch correction in years! Last time I tried they were somewhat accurate in very narrow, specific, scenarios, and completely off in everything else. Wonder if they are any better now, maybe someone threw machine learning at it or something.
Comment: It's not something I've really played with in a long time either. I used to use Melodyne for some pretty intricate editing - changing phrasing rather than just pitch, but a full-blown re-harm, no. It has been done though - this is probably the most famous example - https://www.youtube.com/watch?v=y6KmiIq2-m8 It takes your ears a minute to get used to it, especially if you already know the original song well.

Applying Autotune to a Video


Outbound Email module buttons stay disabled

Question: I have installed Outbound Email module, all the 4 services(Queue, Tracking, Bounce and mailer) are running, DBs are all installed and have provided Rights and permissions for Mailing Management. Have tested the same some time back. But now, the whole module is coming as disabled. I am trying to figure out the cause for the same. Can somebody help me on this?
Comment: Could you clarify what the issue is? "Coming as disabled" doesn't mean anything to me. What exactly are you seeing and where? Any error messages?
Comment: Peter -- I am not able to see Outbound email folder in any of the publication which means I am not able to add any Mailings/DLs and also the Email Management module in the Top menu is coming as disabled. Let me put an image to clarify the same.
Comment: Consider Peter's answer and please learn to give back to the community as well. So many questions you have asked but lots of them are still marked as unanswered. Would you mind sharing what happened to those scenario - got resolved, still unresolved, none of the answer provided resolved it and you have follow some other path to get it resolved.Please note this is a Give & Take community and not an official SDL Support. Everyone in the community will appreciate your give back to the community
Answer: If all of this used to work for you and now it does not, the most likely scenario is that your Outbound E-mail license has expired (or Audience Manager, which it depends upon). The logs will tell you as much, so check the Event Viewer as well as the OE log files on disk.
Answer: It was a browser issue. Though there was one error but after fixing that too, it was not working on GC. It is working fine on IE and FF.


how to calculate this exponential function integral

Question: how to integrate this function $$\int \frac{1}{\sqrt{2\pi}}e^{-z^{2}/2}dz$$, what would the resulting function be, i tried integrating in wolframalpha but it only gave me this solution $\frac{1}{2}\text{erf}(\frac{z}{\sqrt{2}})+c$, erf stands for error function, which i have no idea what it means, can someone show me what the resulting function is going to be, btw this function is for finding area under the standard normal curve
Comment: There's no closed form expression for the cumulative distribution function of the Normal distribution.
Comment: then how do you evaluate it for the z score to get the probability?
Comment: ok let me ask this then instead, having the Z score value how can i compute the probability without referring to the standard normal table? whats the easiest way of calculating this probability?
Answer: As Sebastian mentionned, there are no closed form expression for this cdf. Many results in Probabilities and Financial Mathematics (for instance) refer to expressions with the $erf$ function.
Should you be interested in numerically approximating it, you may apply the following classical methods :
 - trapezoidal rule
 - quadrature formulas (Gauss-Lobatto among others)
Unfortunately, they will give you a poor approximation (despite the integrand's regularity) in comparison with the classical tailored approximation mentioned in :
https://stackoverflow.com/questions/457408/is-there-an-easily-available-implementation-of-erf-for-python
Watch out for the division by '0.' exception though.
Comment: The `erf` function and the complementary error function, `erfc`, are available in most standard math libraries, including C/C++'s [math.h](http://pubs.opengroup.org/onlinepubs/009695399/functions/erf.html) so I wouldn't implement it myself if possible.
Answer: Showing that this is, indeed, a density function (integrates to 1 over the whole real axis) is a standard example in multivariate calculus: instead of calculating it, we calculates its square, then changes to polar coordinates, which results in an integral we do can solve:
\begin{eqnarray}
    \left( \int_{-\infty}^{\infty} e^{-z^2/2} \; dz \right)^2   \\
     &=& \int_{-\infty}^{\infty} \int_{-\infty}^{\infty} e^{-x^2/2} e^{-y^2/2}\; dx dy \\
     &=& \int_0^{2\pi} \int_0^\infty e^{-r^2/2} r \; dr d\theta  \\
    &=&  2\pi \int_0^{\infty} r e^{-r^2/2} \; dr  \\
    &=&  2\pi \cdot 1 = 2\pi
\end{eqnarray}


QGIS 2.14.1 OpenLayers plugin missing

Question: I have installed QGIS 2.14.1,  I am looking for the OpenLayers Plugin which I could not find under Install Plugins, as well as Web menu.
Comment: Does your Plugin Manager actually manage to connect with the online plugin repository?
Comment: try using quick map services plug in
Comment: Hello  Gerardo,  I am not able to find out Quick map services plug in.
Comment: Hi, Can you please help me, how can I confirm this? as far as I can see, it starts 'Fetching Repositories'.
Comment: If you are behind a proxy or firewall, it might not get further. Also, check taht you have python-qgis installed too if you are on on a linux system.
Answer: After Selecting the Plugin Tab you should be getting

Connected Status for the url
QGIS Official Plugin Repository
http://plugins.qgis.org/plugins/plugins.xml
?qgis=2.14
Check the Enabled button is active
as a test check in your browser you can see
http://plugins.qgis.org/plugins/plugins.xml with all the plugins available.

QGIS 2.14.1 OpenLayers plugin missing


1995 Chevrolet engine swap

Question: I have a 1995 Chevrolet c1500 4.3L. I'm in the process of swapping the engine out for a 1993 350 and I'm just trying to figure out what to do. I'm assuming I'll need a new engine wiring harness for the year of engine and a new ecu. Is that all I'll have to change up? Is there any place you can suggest to find a 350 harness cause I have looked everywhere and I cannot find one
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Answer: I've not done the the swap you're talking about, but I have a good idea of what you're going to need. I'm going to break this down into two separate areas, mainly "needed" and "possibly needed".
Needed:

Engine
ECU for new engine - This could be eliminated if running a carburetor and HEI distributor. An HEI just requires power and provides the timing portion of the ECU ... all in one package.
Wiring harness for new engine - If going carb'd/HEI, much of the old wiring harness could be adapted to get it running
Exhaust connection - Plan on it not mounting to the exact same position as the V6. Welding may be in order to fix this, or possibly getting a V8 Y-pipe to attach to the cat (if using).
Air intake system (air filter) - The two will most likely not be compatible.
V8 radiator - The V6 radiator is not going to be enough.

Possibly Needed:

Transmission & torque converter - Assuming the current is a 4L60e and will bolt up to the new engine. My understanding is the ones used for a V6 weren't built as well as the ones for V8s (if you can consider the V8 ones built  well enough for their intended purpose). The V6 torque converter may not be at the correct stall for the new engine.
Upgraded fuel pump - Not sure if the V6 and V8 have the same fuel pressure requirements.
Motor mounts - Most often, the V6 and V8 do not share motor mounts
Reconfiguration of the K-member - The K-member supports the engine as well is what the front suspension ties to if an independent suspension up front. Quite often, the K-member is different between the two engines, though bolt in of a V8 K-member is usually fairly painless, unless you live in the rust belt (for obvious reasons, lol)
Oil Pan - If the K-member doesn't need to be changed, there is a large chance the oil pan on the V8 may interfere with it and would need a different type (or modification) in order to work.

As far as a wiring harness, if you're still going that route, I can't recommend one for you as we don't do that on this site, but if you look to a company called Painless (no affiliation), they may have what you need.

1995 Chevrolet engine swap


Frequency behavior in the electric grid

Question: Is the frequency behavior equal in very distant interconnected points of the grid? For example, if there is a sudden generation drop in Portugal, is the frequency behavior in Portugal exactly the same as the one in Poland? (Poland and Portugal are interconnected inside the CE power grid).
If not, which are the differences in terms of amplitude and time?
Comment: It may help to consider those two points as being connected by a very long springy shaft. The two generators could go out of synch but the more they do the more torsion will be on the shaft pulling them back into alignment. In practice you'd have multiple units along the shaft and multiple shafts joined in by 1:1 gearboxes as various angles.
Comment: As you've done a little research, perhaps you'd tell us how they are interconnected, AC or DC connection? The former requires synchronisation, the latter doesn't. It's not only physics that dictates how connected systems behave, but politics and commerce control the power flows that would synchronise them.
Comment: The "grid" is really a big "matrix" where the "neighbor's nodes" are more important, for regulation, than the other far nodes. So, frequency and amplitude at two different far nodes can't be easily related. Note that frequency is specified in a "close" interval and that frequency is not the only variable but also the close number of "periods" in a specified lapse of time (for the "old" "mechanical" clocks).
Comment: @Neil_UK it is an AC connection. Yes, for sure there would be a small difference in oscillations between the two parts but, what I wanted to underline is if the frequency behaviors are more or less the same in amplitude and time trend. Probably there would be an oscillation mode with opposite directions between the two countries, but are them the same in amplitude and time trend?
Comment: Power is randomly injected or consumed from the grid. it is therefore impossible for there to be a "direct relationship" between two distant points...
Comment: @Antonio51 They are connected to the same grid, therefore the frequencies in two distant interconnected points are for sure linked. It is not possible to have a frequency of 50 Hz in Portugal and a frequency of 50.6 Hz in Poland at steady state. I just want to know if the equilibrium is reached more or less in the same way between two distant points (for sure it would be opposite the trend for them).
Comment: I would add also that perhaps the **most important variable** of the grid is the **"phase"** of the **generators nodes**, because only the "phase" of these nodes is the key that can control the **flow of reactive power** through the grid.
Answer: The frequency trend is similar but not equal in two different distant points of the network after a perturbation. The trends are different in amplitude and time, and this is due to numerous variables (inertia, control actions, different damping, etc...). To summarize, it is different because the electric grid is a very complex system with several variables and regulatory actions involved. But at steady-state, the frequency will have the same value due to the fact that the electric grid is synchronized.
In the picture, there is an example of 3 different frequency behavior after an imbalance of 1 GW in Spain:
Comment: @LShaver If I had to guess, it's a power source going offline: drop in frequency means it's either more load or less generation, and an abrupt drop in generation (earthquake or wildfire or whatever knocking out the connection from source to grid) seems more plausible than an abrupt jump on the gigawatt scale, but I;m no expert
Comment: @LShaver unfortunatelly I don't know what is the source, I took it from notes of my past course of Electric Power System. It was given by my professor in the slides. I want to find a source to check the frequency too, I cannot find it :( If anyone knows a source to check the frequency please tell us
Comment: Open source paper: https://www.nature.com/articles/s41467-020-19732-7 Open database analysis of scaling and spatio-temporal properties of power grid frequencies.  This paper points to this database: Power grid frequency data base https://osf.io/by5hu/
Comment: Was the 1 GW a change in a load or source? Also, what's the source? I'd love to explore this dataset.
Comment: I would add also that perhaps the most important variable of the grid is the "phase" of the generators nodes, because only the "phase" of these nodes is the key that can control the flow of reactive power through the grid.
Comment: You should read this (with google translate, in french) https://fr.wikipedia.org/wiki/Stabilit%C3%A9_des_r%C3%A9seaux_%C3%A9lectriques and this https://www.mainsfrequency.com/
Answer: No, it's not. Speed of light wouldn't allow for things to be "exactly" the same.
Much more importantly, you need to think about how "frequency adjustment" looks like, even if it happens with two generators standing close to each other: either one is the first to become slower, which means there's a phase difference in currents, linearly growing with time, which means there builds a blind power component between, which grows (trigonometrically related to phase difference), and then that leads to a slow down of the other, which has inertia, so,  which leads to the same process in the other direction, so, there's going to be some oscillations in the frequency.
I'd expect you see frequency "dips" to "swoosh" back and forth through the European grid until they're completely dampened away – it's a distributed control system like any other :)
Comment: I explicitly answered that question in my answer. Please re-read my answer, especially the first sentence.
Comment: Muller, yes for sure some generators will rotate with a certain speed at the beginning and others not, ok, ok also the fact that there would be some oscillations, I know, but what I want to point out is the frequency of the grid electrical components (voltage and current). Is the frequency the same (ok, not exactly the same, but approximately equal in amplitude and time trend) between two very distant points of the grid?

Frequency behavior in the electric grid


Closed curves in 3D

Question: Is $R^3$ a union of disjoint closed curves? (Obviously $R^3$ minus a line is). Is this a classical problem?
Comment: I don't think so. If you add a point at $\infty,$ then yes, this is the Hopf fibration of $\mathbb S^3.$ http://en.wikipedia.org/wiki/Hopf_fibration
Answer: Yes, $R^3$ is the union of disjoint circles. Not just homeomorphs of circles, but actual circles. The following simple construction is quoted from M. Jonsson and J. Wästlund, "Partitions of $R^3$ into curves", Math. Scand. 83 (1998), 192-204 (see Theorem 1.1), where it is attributed to A. Szulkin, "$R^3$ is the union of disjoint circles", Amer. Math. Monthly 90 (1983), 640-641. Here is a link to the Jonsson-Wästlund paper: http://www.mscand.dk/article.php?id=77 You can find out about other results like this, some of them depending on the axiom of choice, by reading that paper.

It is easy to see that it is possible to partition a two-punctured sphere into disjoint circles. Let $(x,y,z)$ be coordinates in $R^3$ and consider the union $C$ of the circles of radius $1$ in the $(x,y)$-plane centered at the points $(4k+1,0,0), k\in Z$. Then any sphere centered at the origin intersects $C$ in exactly two points. By covering each such sphere with disjoint circles, we obtain the desired partition.

Here is a picture: http://www.cut-the-knot.org/proofs/tessellation.shtml
I've been told that a partition of $R^3$ into circles was found independently and earlier, but not published, by William Thurston.
Answer: This is probably not what you wanted, but I can do it trivially: For every $r \in \mathbb{R}^3$, let $$C_{r}:I \to \mathbb{R}^3$$ be the map given by $C_{r}(x) = r$. That is, we let each curve be a trivial one point curve. These are all closed. Then we have that $$\mathbb{R}^3 = \bigcup_{r \in \mathbb{R}^3} C_r$$ and the union is disjoint.
Comment: Thank you. What if curves are homeomorphic to circles?
Comment: Yeah, I do not believe that is true, but have not yet been able to construct a proof. I will keep working on it.

Closed curves in 3D


Is there a way to insert a  in a Rich text column?

Question: We have a List in our Sharepoint that we use for reporting quality assurance issues. One of the columns is a 'Description' column which is defined as a Rich text column, is there anyway to insert something along the lines of a
 tag into this text box? I am attempting to paste information such as a Stacktrace which I'd like to stand out.
Comment: Why not use Enhanced rich text?
Comment: I wondered the same thing myself, is there any disadvantage to converting it to that? This list is quite large (5000+ Entries) and in reality they should be using a bug tracking system as opposed to this sharepoint list, but that is neither here nor there.
Comment: I don't see any disadvantage.
Answer: You can dump HTML into this field as long as you render it without escaping the content. It really depends on the control used to render the content of the field.
Comment: AFAIK this is just a standard control that shipped with sharepoint (nothing fancy?) Attempting to insert a `` did not work as expected (using IE 8 to edit the field). I know that when the sharepoint site is browsed with Firefox I am dumped to the underlying HTML (I assume because its because that editor is an ActiveX Control) I have not attempted to insert a `` there
Answer: If you simply want to format a single column of your list using
, you can do this using XsltListViewWebPart formatting.
To accomplish this, edit your list in SharePoint Designer (Ribbon -> List -> Edit list), and go to code tab:

Find XsltListViewWebPart tag, and add following Xsl tag:
<WebPartPages:XsltListViewWebPart runat="server" ...>

    <Xsl>
        <xsl:stylesheet xmlns:x="http://www.w3.org/2001/XMLSchema" xmlns:d="http://schemas.microsoft.com/sharepoint/dsp" version="1.0" exclude-result-prefixes="xsl msxsl ddwrt" xmlns:ddwrt="http://schemas.microsoft.com/WebParts/v2/DataView/runtime" xmlns:asp="http://schemas.microsoft.com/ASPNET/20" xmlns:__designer="http://schemas.microsoft.com/WebParts/v2/DataView/designer" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:SharePoint="Microsoft.SharePoint.WebControls" xmlns:ddwrt2="urn:frontpage:internal" xmlns:o="urn:schemas-microsoft-com:office:office">
        <xsl:include href="/_layouts/xsl/main.xsl"/>
        <xsl:include href="/_layouts/xsl/internal.xsl"/>

        <xsl:param name="AllRows" select="/dsQueryResponse/Rows/Row[$EntityName = '' or (position() >= $FirstRow and position() <= $LastRow)]"/>
        <xsl:param name="dvt_apos">'</xsl:param>

        <xsl:template name="FieldRef_printTableCell_EcbAllowed.StackTrace" match="FieldRef[@Name='StackTrace']" mode="printTableCellEcbAllowed" ddwrt:dvt_mode="body" ddwrt:ghost="" xmlns:ddwrt2="urn:frontpage:internal">
            <xsl:param name="thisNode" select="."/>
            <xsl:param name="class" />

                <xsl:if test="@ClassInfo='Menu' or @ListItemMenu='TRUE'">
                    <xsl:attribute name="height">100%</xsl:attribute>
                    <xsl:attribute name="onmouseover">OnChildItem(this)</xsl:attribute>
                </xsl:if>

                <xsl:attribute name="class">
                    <xsl:call-template name="getTDClassValue">
                        <xsl:with-param name="class" select="$class" />
                        <xsl:with-param name="Type" select="@Type"/>
                        <xsl:with-param name="ClassInfo" select="@ClassInfo"/>
                    </xsl:call-template>
                </xsl:attribute>

                <xsl:apply-templates select="." mode="PrintFieldWithECB">
                    <xsl:with-param name="thisNode" select="$thisNode"/>
                </xsl:apply-templates>

        </xsl:template>
        </xsl:stylesheet>
    </Xsl>
</WebPartPages:XsltListViewWebPart>

I got following look after these changes:
Comment: While this isn't quite what I want (the description column is a combination of free-form text, comments, stack traces, etc) this could prove useful in other places, thanks for taking the time to write up this excellent answer and including screen shots!
Comment: Thanks! Anyway, XSL transformations have wide capabilities. Of course, you will need to do more code, but with xslt you even can parse bbcode! Check this question: http://stackoverflow.com/questions/1870423/parsing-bbcode-with-xslt-2-0


Can I use the hotel shuttles between McCarran Airport and the Strip without a hotel booking?

Question: There appear to be many free hotel shuttles between McCarran International Airport and the Strip or the downtown. If I don't book a hotel, can I still use the shuttles? Can I also get back from some hotel on the Strip (or in the downtown) to the airport?
Comment: @Max In general from the airport to the hotel there is no name list.  From the hotel to the airport there may be a name list if you have to book a shuttle at a particular time during a busy period.  I also don't know about Las Vegas, but I have previously taken shuttles to hotels at LAX without a room booking.  However I have done so in order to use the gym so I can have a shower (and paid for the privilege)
Comment: Don't hotel shuttles have lists of names ? even if they are free ?
Comment: @Max I don't know about Las Vegas (that's why I asked this question), but in Macau I've taken Wynn shuttles without staying there with no problems.
Answer: No, these shuttles are provided for hotel guests, not for anyone to use. Also, some cursory research by Googling seems to show that most major hotels on the strip do charge their guests for using the shuttle. The hotels that provide free shuttles tend to be not the ones you think of when you want to stay on the strip.
Those that do offer a free shuttle service seem to all include a disclaimer similar to this one (happens to be the first one I found on Google, emphasis mine):

Silver Sevens offers complimentary shuttle service to and from the
  McCarran Airport, exclusively for registered hotel guests.


How much time does a search console take to show mobile and desktop speed(experimental)?

Question: I have submitted my one of the website on google search console in Nov. 2019 but right now(Feb 2020) they not show mobile and desktop speed(experimental) data. why? How much they take a time?

Answer: Google doesn't offer any insight on exactly how long or all the requirements, but through my experience it depends on web traffic. Google does say it depends on real world usage data which also confirms what I'm saying. Once you get sufficient amount of web traffic going to your site it will be enough for it to be indexed and listed in all the various consoles (speed, mobile, logos, coverage, etc).
Comment: How much traffic does it need?
Answer: I think it will update in a week. I keep checking on webmaster insights daily because Google webmaster having always error sometimes here sometimes there. Mobile speed insights only show how many URLs of your websites are slow or fast. Noting else!
See the screenshot I have taken for my website.
Comment: In a week google shows mobile speed data, i think it's not possibe. I have submitted my site in search console in Nov. 2019 but still i am not get(Feb. 2020) mobile and desktop speed data.


Tried to make USB stick from OS X

Question: When trying to make a USB stick for Mac I got this error:
MacBookPro-UserName:~ UserName$ hdiutil convert -format UDRW -o ~/ubuntu/USB-Overdrive-302.img ~/ubuntu/ubuntu.iso
hdiutil: convert failed - No such file or directory

Any help appreciated.
Comment: Add more details and you will get better responses
Comment: Most likely there is no ~/ubuntu/ubuntu.iso what does $> ls ~/ubuntu/ubuntu.iso say?
Answer: You're showing a file missing, which indicates the command had the wrong path to the .iso file
We are only using hdiutil to convert the Ubuntu ISO to an IMG format which mac can use.
Use the hdiutil command to convert the .iso to an IMG file in a directory on your hard drive.
Then use the dd command to actually copy the files over.
How to install Ubuntu on MacBook using USB Stick
Make sure you have the paths right - the tip to drag and drop the file or copy and paste the file into the terminal window is a good one:  It will give you the exact location, not a relative one.
Answer: Try
hdiutil convert -format UDRW -o <distnation-name> <source-name>

This worked for me. Note that the destination comes before the source.
Answer: You are using the wrong syntax. Move the input file name to first argument,
so it's convert input.iso -format UDRW -o output.iso
Answer: If you don't care about what's on the drive, USB boot sticks can be created on most unix based systems without any extra software just run from terminal:
dd if=/path/to/ubuntu.iso of=/dev/usbdevice

It works like a charm but THIS WILL DELETE ANYTHING ON THE USB DEVICE. Also make sure that the path to the actually usb device, not a partition. For example if the usb device was sdb you might see a primary partition, sdb1 in /dev. of=/dev/sdb1 will not work. You must write to the actually usb device with of=/dev/sdb or the usb device will not be recognized as a boot disk.
When you want to use the usb device for anything else, you can make a partition with the remaining space and it will still function as a boot disk or you can reformat the entire disk and use it again for whatever purpose. dd is a real gem that is often overlooked. Keep it simple.
Comment: To add to dwrad's post, u might need to add sudo before, like so… `sudo dd if=/Users/marcel/Downloads/ubuntu64.iso of=/dev/disk2`

Tried to make USB stick from OS X


$L^2$-norm of a solution of the heat equation

Question: Let $u\in\mathcal{C}^{2,1}(\mathbb{R}^n\times (0,\infty))$ be a solution of the heat equation $$\left[\begin{array}{ll}u_t-\Delta u=0& \mathrm{in}\ \mathbb{R}^n\times(0,\infty)\\ u(x,0)=u_0(x),&x\in\mathbb{R}^n\end{array}\right.$$
where $u_0\in\mathcal{C}^0_c(\mathbb{R}^n)$. The boundary conditions above are meant in the following sense: $\lim_{t\to 0, x\to x_0}u(x,t)=u_0(x_0)$ for all $x_0\in\mathbb{R}^n$. If we assume in advance that $|u|\to 0$ as $|x|\to\infty$ then the following relation holds for all $t>0$:
$$\|u(\cdot,t)\|_{L^2(\mathbb{R}^n)}\leq\|u_0\|_{L^2(\mathbb{R}^n)}.$$
How to prove this result? I am required to use an energy method whence I started with $E(t):=\int_{\mathbb{R}^n}u(x,t)^2dx$ and tried to prove that this function is differentiable for $t>0$ with non-positive derivative. Therefore I introduced $\Omega_n:=B_n(0)$ and considered $E_n(t):=\int_{\Omega_n}u(x,t)^2dx$ (although it is not clear to me why the derivative of $E_n$ converges to the one of $E$). Differentiating $E_n$ and using the PDE as well as integratio by parts I arrive at:
$$E_n'(t)=\int_{\Omega_n}2uu_tdx=2\int_{\Omega_n}2u\Delta udx=-2\int_{\Omega_n}|\nabla u|^2dx+2\oint_{\partial\Omega_n}u\frac{\partial u}{\partial\nu}dS.$$
How to proceed? Although I know that the modulus of $u$ converges to 0, I do not know how to conclude something similar for the normal derivative. Is this ansatz reasonable after all? Thank you very in advance!
Comment: Would not passing to Fourier transforms help?
Comment: I guess it is quite difficult. I can't see how you can show that $E$ is finite.
Comment: @Urgje Unfortunately, the Fourier transform was not introduced in my course. I am required to use an "energy method" which brought me to my ansatz above.
Answer: Since $u_0$ has compact support, it follows that $u$ and its derivatives decay at infinity. This justifies your argument.
You can arrive to the same conclussion using that
$$
u=G_t\ast u_0,
$$
where $$
G_t(x)=(4\,\pi\,t)^{-n/2}\,e^{-|x|^2|/4t}
$$
is the heat kernel:
$$
\|u\|_2=\|G_t\ast u_0\|_2\le\|G_t\|_1\,\|u_0\|_2=\|u_0\|_2.
$$
Comment: There is no uniqueness. But the other solutions are "wild", and they are not in $L^2$ for $t>0$. There is uniqueness in the class of functions bounded by a quadratic exponential.
Comment: Ok, I know that $u=G_t\ast u_0$ solves the present problem. But, unfortunately I have no uniqueness result available. Is there a way to prove the decay of the derivatives for an a priori general solution of the problem?
Comment: Ok, this uniqueness result is new to me. So for only having a general solution of the given problem, it appears to be rather difficult to say anything if one does not know that it actually coincides with the convolution of heat kernel and initial data.
Comment: Thank you for your answer! How can one prove the decay of the derivatives at infinity?
Comment: From the formula $u=G_t\ast u_0$. If $u_0$ is not smooth, there will be a dependence on $t$.