Water and Electronics?

Question: I've read a lot about people cleaning keyboards in the dishwasher. But how does the water damage electronics? Does it cause shorts on the ICs on the internal circuitry or physically get in the IC(which I can't see happening). So what actually happens?
Comment: There are actually purpose-built circuit board washers used to clean excess flux.  An example can be seen at this [link](http://www.stoelting.com/cleaning-equipment/electronic-assembly-cleaning-systems/batch-stencil-cleaner.php)
Comment: The bad stuff happens if the circuit is powered up while being submerged. Also, immersion for extended periods in water that is dirty, or excessively acidic or alkaline. I mean if you toss a circuit board into a river and then find it on an ocean beach somewhere, all bets are off.
Comment: By the way, in high school, I took apart a floppy disc (removed it from its plastic casing), and washed finger prints from it with soap and running water, then dried and resassembled. All data read perfectly.
Answer: Many electronic assembly lines have a water cleaning machine in them.  Basically it runs the PCB through it on a conveyor belt while spraying it with water.  One smaller contract manufacturer I visited actually used standard dishwashers to clean PCB's (but had a closed water system, so no bad stuff made it into the sewer).  In my lab, we use water soluble flux that must be cleaned with water, as the flux itself is very conductive.  I simply rinse the PCB in the sink and dry it.
There are several important things to note when washing a PCB with water:

The PCB should not be powered.  This seems obvious, but people often forget about batteries for the real-time-clock and stuff.  Sometimes the batteries will survive the washing step, but it's best to not tempt fate.
The PCB should be completely dry before powering it up.  This is the tricky one, since there are many small nooks and crannies for water to go into, and it doesn't evaporate quickly in those tight spaces.   I'm in Colorado, where the humidity is often less than 30%, and I will either let the PCB drip dry for more than 24 hours or use a heat gun to speed things up.  If you're in a more humid climate then extend the drying time accordingly.
Some parts don't survive washing.  Speakers, buzzers, and microphones are the big ones.  Some switches and buttons don't like being washed either.  Of course there are always exceptions.
If your water has a high mineral content then you might want to do a "spot free rinse" using deionized or reverse-osmosis-ized water.

The #1 way water damages the electronics is by shorting things out while the power is on.  The #2 way is by corrosion.  Interestingly enough, it's not the water that does the damage but all the impurities that are dissolved in the water.  Pure water doesn't do much (but look at it wrong and it'll get impurities).  Of course, not powering on the device and drying it relatively quickly will prevent both of these problems.
Comment: Compressed air is also a great way to dry wet, populated PCBs. Of course, it does require a compressor, but if you already have one, it's a great way to get everything really dry.
Comment: Also, interesting fact: *Pure* water is actually a *very good* insulator (>18MΩ/cm, better than mineral oil, IIRC). However, pure water will actually fairly aggressively scavenge ions from whatever container it is in, so it is very hard to *keep* it pure.
Comment: @Fake Name  You have to be a bit careful with compressed air, as it can create static zaps.  Still, it can be quite useful.
Comment: Any dry air flow can create static (there are ionisers to mitigate this) and it can also mechanically damage fragile parts or force water into places it usually would not go.  Shop air may also contain oil vapour or aerosols that could cause a dust attracting film.  Clean dry warm air from a dehumidifier unit is probably the fastest for drying.
Answer: If the device is off and you are just using plain water it's not going to harm the device as long as you dry it off again before turning it on. Dishwashers work quite well for this, but you shouldn't put much soap into it (too much and the residue could stick to the PCB and cause problems.
If you run electronic equipment while it's wet then yes, it will short out. While water itself is not a conductor, any dissolved minerals/salts will make it very conductive. Since there are minerals in every form of tap or natural water it can be very bad for a computer.
That being said I've literally spilled an entire glass of water onto a working motherboard and it continued to work for the next 5 minutes while I saved my work and shut down. Dried it off and there was no damage.
Comment: Note: Do **not** so this in a dishwasher that you also use for food.
Comment: @Fake Name  Doing this once in a while isn't too bad.  But I do run the dishwasher empty after, to clean it out.
Comment: I wouldn't use the dishwasher for cleaning flux or anything similar - just the grease and dirt in your keyboard. I don't see a problem with this, especially since it isn't a regular event.
Answer: Years ago a friend asked me for a way to slightly illuminate a small river in a miniature diorama. There was almost no space to hide the little circuit (it was a PIC with internal oscillator that handled 3 red leds) and no time to rebuild that diorama part, so with just 3V of supply (to limitate water electrolysis) we simply submerged the circuit in the water reservoir. And as all provisional hacks, it worked for years without problems :-)
Comment: Low voltages are the least likely to cause electrolytic problems.  Gold and lead are also pretty resistant in the absence of reactive ions. In such situations a decent coat of clear paint would add to the protection.

Water and Electronics?


Create unique ID's in VFP

Question: I need to create unique record id's in VFP based on mailing information: zip5, address, lastname, firstname.  Once created, relational tables will be loaded in SQL server 7 with the unique ID's. Any suggestinos?
Answer: You can use a GUID: GUID entry at FoxPro Wiki.
And here are some examples.
Easiest one using WSH...
<code>   * VFP 7+
   oGUID = CreateObject("scriptlet.typelib")
   cGUID = Strextract(oGUID.GUID, "{", "}" )

   * Other VFP
   oGUID = CreateObject("scriptlet.typelib")
   cGUID = substr( oGUID.GUID, 2, 36 )
</code>
Answer: VFP does have support for unique IDs - in that it has Primary Indexes (which can be based on multiple fields - but make sure the key length is fixed, so if your VFP table uses varchars you will need to pad the fields) and a table can also have Candidate Indexes (where the indexed field(s) must be unique, just like a primary key, but you can have multiple candidate indexes per table).
Either of these will enforce uniqueness in your fields, but generating a primary key based on zip5, address, lastname and firstname will be inefficient. The suggestion of GUIDs will work nicely, or if you have VFP8 or later you can use an Autoinc column, which is analogous to an Identity column in SQL Server.
Incidentally, unique indexes are only used for backward compatibility..
Answer: I created my own function for that purpose to return a unique identifier. When I have a new record I just scan the database and have the function replace the unique identifier field (I call mine UID) in the database with a new uid if the record does not have one.
<code>FUNCTION UIDgenerator()
   LOCAL c_UID
   LOCAL c_dump

   c_UID = STRTRAN(SYS(2015),"_","") + [-]

   c_dump = STRTRAN(SYS(2015),"_","")
   c_dump = STRTRAN(SYS(2015),"_","")
   c_dump = STRTRAN(SYS(2015),"_","")

   c_UID = c_UID + STRTRAN(SYS(2015),"_","")

   RETURN c_UID

   endfunction() &&UIDGenerator
</code>
You don't have to do c_dump 3 times, but I wanted the identifiers to be a little more further apart.

Create unique ID's in VFP


Patankar's algorithms for Numerical Heat Transfer and Fluid Flow

Question: I am looking for the algorithm of Patankar (for example, SIMPLE, SIMPLER, SIMPLEC and PISO) written in Fortran for the simulation of heat transfer and fluid flow.
Answer: Probably the best thing is to use codes from a book by J.Ferziger and M. Peric "Computational Methods for Fluid Dynamics", available from Springer ftp site. site.
There you will find F77 codes for 2D Navier-Stokes equations. I suggest starting from 2dc folder and pcol.f code which uses collocated variable arrangement, instead of staggered which was explained in Patankar's book.
Personally I think the Patankar's book appeared three years too early, and it therefore didn't include Finite Volume Method version using collocated variable arrangement enabled after introduction of Rhie-Chow interpolation in 1983. Also Patankar gives a sketch of what is vertex-based median-dual approach, also very important for unstructured meshes, and doesn't go into detail.
I think there is a need for a new book on FVM using general unstructured cells from the start and not using square cells that reduce calculations to something similar to finite differences.
My advice-learn from the codes above, and start reading papers as soon as possible. There are good papers explaining FVM for fluid flows in a comprehensive and modern way.
References that I recommend are:

S. Muzaferija and D. Gosman, Finite-Volume CFD Procedure and Adaptive Error Control Strategy for Grids of Arbitrary Topology, Journal of Computational Physics,138, pp.766-787 (1997) (discretization procedure, least-square cell-centered gradients, adaptive grids)
I.Demirdzic, S. Muzaferija, Numerical method for coupled fluid flow, heat transfer and stress analysis using unstructured moving meshes with cells of arbitrary topology, Comput. Methods Appl. Mech. Engrg, 125, pp.235-255 (1955) (both of these papers are written by CD-Adapco people)
D. Kim, H. Choi, A Second-Order Time-Accurate Finite Volume Method for Unsteady Incompressible Flow on Hybrid Unstructured Grids, JCP, 162, pp.411-428 (2000)
M.Darwish, I. Sraj, F. Moukalled, A coupled finite volume solver for the solution of incompressible flows on unstructured grids, JCP, 228, pp.180-201 (2009) (!!!)
F.-S. Lien, A pressure-based unstructured grid method for all-speed flows, Int. J. Numer. Meth. Fluids, 33, pp.355-374 (2000)
S.R. Mathur and J.Y.Murthy, A pressure-based method for unstructured meshes, Numerical Heat Transfer, Part B: Fundamentals, 31(2),pp.195-215 (1997) (Fluent people)
B. Basara, Employment of the second-moment turbulence closure on arbitrary unstructured grids, Int. J. Numer. Meth. Fluids, 44, pp. 377-407 (2004) (AVL-Fire\Swift developer)
H.Jasak, H.G.Weller and A.D.Gosman, High resolution NVD differencing scheme for arbitrary unstructured meshes, Int. J. Numer. Meth. Fluids, 31, pp. 431-449 (1999) (introducing Gamma differencing scheme for convection terms, OpenFOAM developers)

The list may extend to PhD theses. In OF community H. Jasak's PhD thesis is often cited and is a good reading.
Comment: Any suggestions on good papers explaining FVM for fluid flows?
Comment: I'll edit the answer to include some references.
Comment: Thank you very much sir `Johntra Volta` for all the interest you have given to my question. I think that the book `"Computational Methods for Fluid Dynamics"` is very interesting for me. But, since I am a beginner in the field of simulation with Fortran 1990, what books can explain how to pass from the theory of FVM for fluid dynamics to the programmation in the Fortran and especially f90 ? Books in the kind of `"Numerical Recipes in Fortran 90. The Art of Parallel Scientific Computing. by William H. Press, Saul A. Teukolsky, William T. Vetterling and Brian P. Flannery."`
Answer: If you still need help, you can refer to this Github
https://github.com/xuaoxiqi/Computational-Fluid-Dynamics
It has lid driven cavity flow solved using SIMPLE and is quite explanatory.


Dapper return result fails after enumeration

Question: I have a dapper query multiple function that outputs a number of different lists except for the very first list. While debugging I discovered that when the code gets to the following line in Dapper the results disappear:
public IEnumerable<T> Read<T>....
    var result = ReadDeferred<T>(gridIndex, deserializer.Func, typedIdentity); //result has correct db values here
    return buffered ? result.ToList() : result; //result = Enumeration yielded no results

The ReadDeferred function does not process any code in the try or finally clause. Why is the value of result being lost in enumeration?
Here is my code that calls dapper:
var results = con.QueryMultiple("GetInspections", p, commandType: CommandType.StoredProcedure, commandTimeout: 5000);
var inspectionDetails = new Inspection
{
    InspectionDetailList = results.Read<Inspection>().ToList(), <-- this one does not popuplate
    SOHList = results.Read<SOHPrograms>().ToList(),
    BuildingList = results.Read<Building>().ToList(),
    AdministratorList = results.Read<Employee>().ToList(),
    NotAdminList = results.Read<Employee>().ToList(),
    InspectionList = results.Read<InspectionList>().ToList()
};

return inspectionDetails;

I have verified that there are result sets being returned for each list from the sql query.
Answer: This problem had a two part answer, because I had two problem errors. The first was that I was calling the InspectionDetailList as a list from inside the Inspection object which I removed and the second was to change the code that calls dapper to use a using statement and call the pieces individually. Thanks goes to a friend and one of the overflow posts found here.
using(var results = con.QueryMultiple("GetInspections", p, commandType: CommandType.StoredProcedure, commandTimeout: 5000))
{
    var inspectionDetails = results.Read<Inspection>().First();
    inspectionDetails.OshList = results.Read<SOHPrograms>.ToList();
    inspectionDetails.BuildingList = results.Read<Building>.ToList();
}


Arduino power sources

Question: Is it safe to connect a USB input to an Arduino (Nano) at the same time as an external regulated 5V supply to its 5V pin is connected, assuming the supplies have common grounds ? Will (I hope) the external 5V be used so as to not draw too much current out of the USB supply ?
Answer: From the Arduino Nano at Arduino.CC:

The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.

Or, take if from the schematic:
Answer: OK, I see a section labelled +5V auto selector, with a Schotky diode between +5V and the VUSB rail, I don't understand enough about electronics to see what this does though. I get that if I supply 7V, say, to Vin then the Nano will use that as the 'highest voltage source'. I could perhaps use a variable voltage source fed from the batteries and set it to, say, 5.2V and force the Nano to use that? The reason for all this is that the Nano will be connected to a Raspberry Pi via USB for communicating with the ros system, and the Pi is unable to supply much from its USB ports, it cant run, for example, a WiFi dongle, mouse and keyboard at the same time.

Arduino power sources


Google crawl speed -- how fast can it go?

Question: I have a huge website with 5 million pages. Currently Google indexes about 10,000 pages per day. This is very slow, I still have lots of pages that I can't get indexed. Does anyone know what is the upper threshold for crawl speed?
Comment: In general, 5 million quality pages don't just suddenly appear on the web. Have they been moved from somewhere? If they are low quality pages, Google will not be interested in crawling and indexing.
Comment: When you say that 10,000 pages per day are "indexed" how do you know?  Is this the number that is crawled, or is this how much the number of indexed pages is increasing in webmaster tools each day?
Comment: It is shown in the crawl graph.
Answer: The maximum speed of indexing is 10 times per second. This is the speed of StackOverflow indexing by Google (read this).
Comment: That isn't an absolute upper bound.  Just what is available to a site with stackoverflow's pagerank.  I've worked with higher PR sites that have higher crawl rates available.
Answer: Google's crawl rate is a function of:

Pagerank -- the more reputation and inbound links your site has, the more it will be crawled.  Within your site the most prominent pages (like the home page) will get crawled more often because they have higher pagerank.
How often your pages change -- pages that change frequently will get re-crawled more often that pages that don't.
How fast your server is -- rather than having a number of pages per day that Googlebot downloads, it appears that it is limited by the amount of time spent downloading pages.   Making pages smaller and increasing the speed of the server can both let Googlebot crawl faster.

In addition, Googlebot has several different crawl modes.

Re-crawl mode -- it will come back and visit pages that it has visited before.
Fresh crawl mode -- it will crawl lots of new pages in a new section of a site.  The higher the pagerank of the site, the more pages get crawled.
Stale pages mode -- Googlebot finds a box of old links in the basement and plows through them just for "fun".  These pages are often all pages that no longer exist and are redirected to other pages.  They often have no pagerank and are crawled in URL-length order.

The upshot of this is that the best way to get your site crawled faster is to get inbound links and increase the pagerank.
Answer: Many of the mentioned above is true, although an important remark - scanned and indexed are not the same. So when you think it's 10,000 links per day, in fact it's a big question how many of them did it really manage to open.
Google and Yandex determine the speed based on the value of the website as they see it, but till a certain extent you can interfere in it manually.
There might be though a workaround* to get out of this cycle:

Try changing the GSC Crawl rate settings - it may rescan your website much faster
If you're using a dynamic sitemap.xml file, you may try:

2.1. Adding all the sub-sitemap files directly into the Sitemap section in Google Search Console
2.2. Adding all the sub-sitemap files directly into the robots.txt file, so the search engine will read them not only via the index file but will get referred via robots file (might be quite efficient)
*An important issue to mention about the crawl speed - if your speed settings will be too fast for what in practice your server can handle, a result of this change will be many 4xx/5xx responses, which will disappoint Google even more or just not help much (Google will start saving crawling budget on your website).
So make sure you set the right speed to avoid empty calls - this way you can indeed rescan your website much faster than it normally happens.
Answer: If they're crawling your pages and they're not being found in the search results then the crawl rate is not an issue. This sounds like your website is full of low quality content that Google does not want in its index. Is this original content? Is it quality content? Google not listing your pages indicates that it is not.
Answer: I've found out that it is possible to achieve 2 pages/second crawl speed by improving server responce time. Each page should responce as fast as possible. This may require garbage collector tuning, db tuning and code tuning. If average responce time is better then 50ms per second, then google would index at 2pages/sec, this is experimental fact.


what to do if you commit a sin in ramadan?

Question: what to do if you commit a sin in ramadan and then you feel so ashamed to Allah that you can't even face him. like I cant bring myself to pray and ask for forgiveness because I asked Allah for forgiveness multiple times for same sin I make. I don't know what to do and how to bring myself to pray again. Are not devils locked up in ramadan than why am I making a sin even though I read Quran and pray 5 times a day but I still Made that sin made me hate myself. now I am avoiding salah thinking will Allah forgive me again? and feeling bad and ashamed in front of Allah.
Comment: How about asking Allah for forgiveness and repent?
Answer: Whenever we commit a sin, whether it's Ramadan or not, we should turn to Allah in repentance and beseech His forgiveness. We should never lose hope of His mercy. He is the All-Compassionate the All-Merciful. He is the Rahman Raheem. The Forgiving and The All-Forgiving, Ghafaar and Ghafoor. He loves forgiveness. It's the shaitaan that makes one feel such ashame that they will no longer turn to Allah for forgiveness or repent to Him because the shaitaan doesn't like it when we turn to Him in repentance. He doesn't want Allah to forgive us. He doesn't want us to enter Paradise. So he makes us feel hopeless of Allah's mercy. Yet Allah makes clear that we should never give up on His mercy and no sin is too great that He cannot forgive it. If we meet 4 conditions when we repent and ask for His forgiveness so we are doing it sincerely and with regret doing everything to not commit that sin again then there's absolutely no reason why He wouldn't forgive us, even if we fell into that sin again due to human weakness so long as the same 4 conditions are yet again met, as it's a part of His mercy. So long as we worship Him alone without any partners. That's the only sin, that if we die within without repentance and belief thereafter, He will never forgive. All other sins however bad they may seem; He will forgive.

Do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful (The Qu'ran 39:53)

Will they not turn to Allah in repentance and seek His forgiveness? And Allah is All-Forgiving, Most Merciful (Qu'ran 5:74)

Whoever constantly seeks forgiveness from Allah, Allah will appoint for him a way out of every distress and a relief from every anxiety, and will provide sustenance for him from sources he does not expect (Abu Dawud Book 20, Hadith 1873 Riyad as-Salihin)

... And do not lose hope in the mercy of Allah; indeed none lose hope in the mercy of Allah except the most ungrateful people (Qu'ran 12:87)

Satan threatens you with poverty and orders you to immorality, while Allah promises you forgiveness from Him and bounty. And Allah is all-Encompassing and Knowing (Qu'ran 2:268)

The shaitaan makes people focus on hopelessness so they would overlook the immense hope that is there of Allah's mercy.
Following a sin up with goodness also wipes out the bad deed.

And establish prayer at the two ends of the day and at the approach of the night. Indeed, good deeds do away with misdeeds. That is a reminder for those who remember (Qu'ran 11:114)

And return [in repentance] to your Lord and submit to Him before the punishment comes upon you; then you will not be helped. (Qu'ran 39: 53-54)

Now, as for sinning during Ramadan, only the main Shaitaan is chained up. The jinns are still there. Also, evil can derive from other sources too (e.g. a evil from one's own soul)
Al-Bukhaari (1899) and Muslim (1079) narrated from Abu Hurayrah (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said:

"When Ramadaan comes, the gates of Paradise are opened, the gates of Hell are closed, and the devils are chained up."

And Allah knows best
Answer: It is said in the month of ramadan,the doors of heaven are open,hell closed and the devils chained according to a saying of the prophet muhammad pbuh.
This could mean that people are chaining devils by praying extra and entering heaven and being saved from hellfire.Or it could mean that the devil's evil whispering has stopped and we are doing it ourselves.There are many possibilities.
If you do a sin repent as you would normally as the prophet told us the person who repents is like the one who hasnt sinned and the intention of doing a task is better than the task itself.


A question about a line from World's Greatest Dad

Question: in the movie World's Greatest Dad, we learned the fact that Andrew has asthma, then Robin Williams said: "Then he shouldn't be having milk products." Is this true or is it just a joke?
Answer: Some parents have concerns about the amount of mucus created when their children drink milk, and its affects on the child's asthma.
There's an article from the Canadian Family Physician Journal that directly addresses this question:

Many parents of children with asthma are becoming increasingly reluctant to add milk to their children's diet because they believe it will worsen their children's asthma owing to increased mucus secretion. Recognizing the importance of milk as part of a healthy diet in supporting growth and calcium consumption, is it advisable to restrict milk in the diet?
Answer: Maybe it's a joke because "Is milk good or bad for you?" is question open for polemic like many other food products.
If you aren't allergic milk can only help, but if you are, like 2% of children then it's bad for you.
A recent study published in the medical journal Thorax suggests that full fat milk and butter might be the key to preventing asthma. In a study of 3000 three year olds, it was found that those who consumed most dairy products could be up to 4 times less likely to develop asthma symptoms. This may be attributed to the fatty acids found in full fat dairy products.
Asthma attacks (worsening of asthma symptoms) can be triggered by allergies. There are some food additives or preservatives that people have reported as triggering asthma symptoms.
However many people with asthma also have allergies, and allergic reactions to food can cause symptoms similar to asthma. It is known that around 2% of babies are allergic to cow's milk.


Why is my homemade pork sausage rubbery?

Question: We just made some pork sausage and fryed up a patty to check the spicing.  The taste is fine but the patty is rubbery in texture.  What did we do wrong or not add to the mix?
Comment: Would you describe it also as "dry" rather than "juicy"? What cut did you use? What was your fat/lean proportion?
Comment: We definitely need more information. Can you edit and add your recipe? Perhaps then we can find an answer or some suggestions for you.
Answer: You may have ground your pork too fine (or over mixed it) -- you want to use a relatively coarse grind with a lot of fat when you are making pork sausage.
Comment: agreed. texture needs to be course and cooking time not too long.
Answer: I agree with what has been said above. Over working meat can really have an adverse effect on the texture. There are a few ways I avoid this problem. First, make sure everything your working with is very cold (i.e. meat, seasonings, grinder itself, bowl). The colder it is the less the fat will melt and make a sticky mess that I find makes me more prone to over mixing. Second, I always season the protein first before grinding so that i don't have to mix rigorously to incorporate seasoning post-grind and make the texture poor.
Also, if your cooking from fresh, i find it best to just take a portion of meat from the ground mix and gently shape it into whatever shape you would like and then using a spatula compress it in the pan while it's cooking, this, I find, give me the nice crumbly texture of ground meat rather than the rubbery, spongey texture you are encountering.
Answer: Part of the problem I've encountered with rubbery meat is the terrible quality you find at the stores such as Hy-Vee, Walmart, Target, Aldi, etc.  They are using pork that is mixed with 11% "added ingrdients".  Most of it is made by Hormel.  I hate the stuff.  It won't brown right, tastes salty, and has a nasty, overprocessed texture that is rubbery.
I now buy pork at the Fareway grocery store - they use only all natural meat and it cookes up a lot better. The local meat locker (where farmers have their animals processed) also has much better quality pork - not pumped full of salt water.  The texture and flavor is delicious.
I used Hormel ground pork last night and the results were horrible - it had the texture of a cheap turkey roast, rubbery and grainy.  I wrote to Hormel and told them how bad the product was.  They responded by telling me they're sending free coupons. Puke!
Comment: You've got some good information about meat quality, but it feels like a more of a rant against specific brands. It would be a better answer if you just left that out.


Who were the physical models and the voice actors used for each party member in Dragon Age?

Question: Many of the party members had face models assigned to them in the design phase. I would like to know who the model each party member is based upon is in all three games and also the voice actor for each party member as well. Links would be helpful.
Comment: I could see this being debated as being too broad.. That said, I'm going to provide a list of party members. Hopefully users can edit the 'model actor' with appropriate links, as names can be confirmed. For completion sake, I'll list the few that would not have used human models, as they may have still had human voice actors.
Comment: Though broad, I thought this was an ok question. It is not vague and does have an answer.
Comment: Would you consider changing the question to "who are the associated actors" to include voice acting? Would make it easy for me to fill out this list, and eventually hope to have a more detailed list including physical models, which might in turn ease the opinion of this being too broad
Answer: Dragon Age: Origins

Alistair : inspired by the characters Xander Harris of Buffy the Vampire Slayer and Mal Reynolds of FireFly, voiced by Steve Valentine.
Dog : animal; No actor or voice actor.
Leliana : Modeled by  Alexandra Stein AKA "Alleykatze
Morrigan : Modeled by Victoria Johnson, voiced by Claudia Black.
Oghren : Voiced by Steve Blum
Shale : Voiced by Geraldine Blecker.
Sten : Voiced by Mark Hildreth
Wynne : Voiced by Susan Boyd Joyce
Zevran Arainai : Voiced by Jon Curry

Dragon Age II

Anders :
Aveline Vallen :
Bethany Hawke :
Carver Hawke :
Fenris :
Isabela :
Merril :
Sebastian Vael :
Varric Tethras :
Tallis :

Dragon Age: Inquisition

Blackwall :
Cassandra Pentaghast :
Cole :
Dorian Pavus :
Iron Bull :
Sera :
Solas :
Varric Tethras :
Vivienne :
Comment: Some characters simply will not have face models, as the developer uses several 'models' for inspiration. Alistair appears to be a good example.
Comment: Thanks, it's a start. Please fill in the name of the face model used for each character.
Comment: Good point, you could just write in "no model" or something if you have confirmation on that.
Comment: Leaving the extra information in. Still relevant, and it might be of more use to future readers. In the case of Alistair, there is no specific model. But the developer used the inspiration of other characters in its creation, so they would become 'partial models'... if that makes sense


Linter for Google shell style guide?

Question: Does anyone know of a Bash linter for the Google shell style guide? I have been using shellcheck as my linter with flycheck but it doesn't conform to this standard.
Comment: Is this question about the linter itself, or `flycheck`?  If the former, it's not really an Emacs question, and we should migrate the post to a sister site.
Comment: I'm asking if anyone knows of something that specifically will work in Emacs - I used flycheck as an example for the package I use to handle linting but if another package would handle it that is fine too.
Comment: Maybe it is better to ask the question in other place, since it is about Shell, not Emacs.
Answer: You can use shfmt to format shell/bash code. It is configurable, so you should be able to get the Google style with something like shfmt -i 2 -ci.
It's a standalone tool, but it should be easy enough to integrate with editors and IDEs. There are plugins for vim, atom, and vscode already.

Linter for Google shell style guide?


Trying to get in shape

Question: I'm 5'1 and 90 pounds. For my age (I'm 13 years old), I'm underweight. Some of you may be like don't worry about this, you're so young but I still will worry about it. For those of you who say "eat more" it doesn't work that well for me, I have a small appetite. In 3 weeks I only gained around 1 pound which really concerns me. I wanna get in shape, to gain more muscle.
Comment: Have you hit your growth spurt yet? If not, you may simply not have hit your stride. I was about your weight, and a bit taller, at your age. By 9th grade, I was up to my full adult height of 5'9" and had gained a good 30-40 pounds. I know, you said not to dismiss your concerns, but it just might not be time for you yet.
Answer: Gaining weight as an underweight person (and I know this from experience) is having the balls to eat even though you're not hungry. This does not mean binging, but rather eating healthy food 5-6 times per day, in moderate portions.
But you can help yourself get a bigger appetite by joining a sport. I wouldn't recommend weightlifting just yet, but a form of martial arts or gymnastics is one of the best choices you could possibly make right now. It will make sure that as you grow, you grow in the right ways. It will make you both look good, and feel good.
Obviously, I'm not discounting other sports, and you should go for whatever sport you really want to partake in. Martial arts or gymnastics are suggestions that I know will give you a strong and lean body whether you want one or not.
Answer: You do not necessarily need to eat more, but you have to get correct nutrition:

Six smaller meals a day containing 20-25g protein each time (this is much harder to plan than you think - use a kitchen scale and nutrition tables to check the amount of protein)
Healthy food: Fresh fruit rather than dried or canned fruit. Raw or
slightly cooked vegetables. No fast food.
Slow carbohydrates: Prefer whole grain products and avoid sugar.

Choose some sports, which makes you feel happy and that you have fun. Good feeling is usual the best motivation for using your body and gain muscles mass.
Comment: I would actually discourage eating too much raw vegetables if he wants to gain mass. Cooking releases more calories in the food. The reason why the "raw food" diet works so well in losing weight is that the body can digest so little of it. Overstewing can leech out vitamins and minerals, but no cooking reduces bioavailability.
Comment: I agree. In many cases, the overall nutrition value of slightly cooked vegetables is better than in raw ones. Just think of cooked carrots, which gives you five times the amount of beta-carotene compared to raw ones. My point was to avoid fried and industrial processed vegetables. **Strange stuff in fast-food burgers does not count.**
I need to gain weight too, and I have chosen to get about 50% cooked and 50% raw.

Trying to get in shape


Application as desktop background in Ubuntu

Question: I was thinking, if there is any way to set, for example, a java application as my desktop background? I'd love to see Lotka-Volterra Predator-Prey Model visualization on my desktop.
An example of this program:
http://en.alife.pl/predators-and-prey-the-Lotka-Volterra-model
Answer: I think this answer can be the beginning of an answer for you :)
If I understand correctly, you basically want ot create a live wallpaper
Here are a few live wallpapers you might like.
Isearched quickly, but couldn't find any ressource to create your own though.


I have characters, no plot

Question: I'm trying to write a story with characters that I already designed long ago and also have planned the world for them a bit, but I cannot come up with an interesting plot. What do you suggest I can do to come up with a plot?
Comment: Hey, Andrew! Welcome to Writer SE. Sorry, but this isn't an idea generating forum. Your questions is likely to be closed for this reason, and frankly there is no right answer to it. Maybe they're just a group of friends hanging out, and the reader follows their wacky (but otherwise mundane) adventures? Maybe they're secretly serial killers, and the reader needs to figure out who? There's no way to narrow down all the possibilities, and even less of a method of judging which answer fits based on what's given. (too broad, too story-based, opinion-based. all worth closing your q over).
Comment: Definitely check out our older question [How to derive a storyline from a beginning?](https://writing.stackexchange.com/q/33110/2533), of which this *might* be a duplicate.
Comment: @Fayth85 - I see what you mean (and "broad" certainly fits), but it was a "can do to come up with a plot" rather than a "gimme a plot". Dan and Galastel seem to have made something worthwhile of it. I'm inclined to let it run.
Comment: @ItWasLikeThatWhenIGotHere I am inclined to agree, hence why I didn't VTC. I like the answers given as well.
Answer: You've got characters, you've got a world. What you need is conflict: it is conflict that makes a story. This can be conflict between characters, conflict with some other force ("antagonist" or nature), even internal conflict. Your characters want something, and for some reason they can't have it - they have to struggle for it.
So how do you generate conflict? Consider what isn't right in your world that the characters might want to fix (from helping a homeless person to overthrowing a Dark Lord)? What isn't right and they just have to struggle through (desert, sickness)? If you have a group of friends, what can strain their friendship? If you have a group of enemies, what can bring them together? For each character, what do they need to learn? What are their goals, and what stands in their way?
Consider also what your characters' strong suits are. What events would make those traits shine? When would those traits be a hindrance? How do they clash with other characters' traits? How do they complement each other? Many things could happen to your characters. Which ones would change them? Which ones would be meaningful? Which ones would be funny?
Once you've done this, you've got a hundred ideas, if not for a complete story then for parts of it. Shake those ideas about, see which ones can merge into something larger, what works, what doesn't. That should give you a start. From that start, you can proceed with a story, whether discovery-writing it, or planning meticulously, or something in between.
Answer: There are not that many plots available. Pick one and see what your characters do with it. Your main character(s) can attempt to:

Go (or escape from) somewhere (and maybe come back?)
Get or find (out?) something (that may or may not have previously been lost)

or

Beat (destroy, or drive out) someone/something

The character(s) can fail or succeed, do it together or alone, change along the way or not.
There are many, many, clever variations, and the fun is in figuring out how the thing is accomplished (or not accomplished) along the way. Pick one, don't fret about it, and start writing. If your characters are well defined, with good strengths, flaws, and drives, you can just start them on their way and then let them figure out the rest. Conflicts and obstacles will present themselves before you know it.
Answer: I actually agree with Galastel's answer, but maybe this will also help.
Orson Scott Card came up with his M.I.C.E. Quotient – the idea is that stories fall into 4 broad categories (with overlap), and each has a different kind of character/story focus.
http://www.sfcenter.ku.edu/Workshop-stuff/MICE-Quotient.htm
The four factors are milieu, idea, character, and event.
A summary:
MILIEU: A milieu story concerns the world surrounding the characters you create.
IDEA: An idea story concerns the information you intend the reader to uncover or learn as they read your story.
CHARACTER: A character story concerns the nature of at least one of the characters in your story. Specifically, what this character does and why they do it.
EVENT: An event story concerns what happens and why it happens.
Answer: Discovery Write.
Discovery writing doesn't require a plot, exactly. It does require a problem, undesirable situation, or confrontation to get started; all of these are under the banner of "conflict", and I +1 Galestel for describing how to find some conflict for your characters.
I won't repeat that; but I will note conflict is not necessarily a fight (physical or verbal), it is any problem the MC must deal with. It can even be an entirely mental conflict: guilt (e.g. over cheating), misunderstandings, lost love, urges they cannot control but wish they could, an important scientific problem they are struggling to solve. Anything requiring a struggle and work to overcome, even if the struggle is just in understanding.
Conflict can be external and environmental; the setting can the villain. The power has gone out. The coffee maker doesn't work. There has been an earthquake. The ship has malfunctioned and our heroes are on a strange and dangerous planet with no way home. (e.g. Tom Hanks in "Castaway", no evil person sabotaged the aircraft he was on.)
On to Discovery Writing: The trick here is to understand, up front, you will likely write many pages you intended for publication but will scrap, but that writing serves a purpose: clarifying your characters and your plot. This is how you do the work to understand, for the characters you have defined, what their story must be.
I believe if you have a few cool characters, subconsciously you have the story in you; how they interact will define what their conflict must be, and what their setting must be.
SETTING Character personalities, skills, even dress and attitudes towards each other imply the setting. A super-hacker doesn't exist with computers to hack, students do not exist without a school, sword fighting warriors likely do not exist if there are guns and bullets. Attitudes and actions of people toward others of different gender, race, physical maturity imply a culture in which this is not severely punished.
Work from your characters to a plausible setting that could have produced all of them. If you have to tweak your characters, to arrive at both characters that please you and a plausible "normal world and culture" they come from that pleases you; do it: That is rewrite. Get used to it! Note that where they come from does not have to be where the story takes place, but where they come from can influence whether it is plausible they wound up where the story takes place, and will definitely influence their interactions throughout the story.
Pick a conflict. Any conflict. You want to write a scene with one or more characters in it, something to help you understand the characters you have until now only engineered. Think of this as a field test, we are going to write some prose, an actual fictional scene, to see how this character works, and how their personality plays into their actions.
I usually pick two characters I think are most likely central to the story, and try to write their first meeting as a conflict. How do they get together? What excuse can I come up with for them to get together? Why does A need B's cooperation; or did A save B, or inadvertently harm B, or what exactly happened? You've got some back stories, which two, when you rub them together, create the most sparks?
I have written such meetings that never get into the final story; but when I write them I write as if they will. This field test helps me discover the characters and flaws in my own thinking about them. I write several such field tests; often to see how my characters act in their normal life (which is where the reader expects to meet them). Your character design is a lot of "telling", you need to transition to "showing" how those traits influence your character's behavior and interactions with others. The process of doing that, these field tests, will inevitably (in my case) change the design, smooth out the rough edges and make the character more "real".
Eventually my goal is to have characters feel to me like they think for themselves, more like actual people I know, so when I write them what they do in response to various kinds of provocations is not really up to me.
For example, I find my character, Diane, will not ignore some lout grabbing her ass, nor will she laugh it off or walk away; and I can't make her do that to serve some plot point, it feels unnatural to me, inconsistent with her character. She's going to hurt somebody! Now I might have designed that into her, or discovered this trait through writing, but it begs for a field test: A scene where hurting somebody for playing grab ass is not going to be easy; a boardroom meeting, in a courtroom, an important client, the principle of the school threatening to expel her child. What does Diane do then? Follow through? escalate? De-escalate? I have to write a scene to figure that out, one where I consider her dialogue and conflicting emotions carefully.
I believe the right full-story central conflict for the characters is something you will discover as you develop them in prose and develop, as an author, coherency in the parts you can't really cover in design.
The Plot.
As Stephen King (a discovery writer) says, all stories have to turn out somehow. Once you have a clue as to the central conflict, your field tests are done. Discard them or revise them as needed to make them consistent with your characters, and put them aside until you need them. Now is the time to write your opening scenes to introduce these characters to the readers, each in their normal world, dealing with normal everyday conflicts or problems, together or separately.
You invent these everyday conflicts and they won't matter too much; they are a vehicle to carry reader interest, following a character doing something that reveals elements of their character so the reader will care about them (in a good way or bad way). Later, you may revise them, perhaps even to different events: You will be discovering many more things in writing, about the plot and characters, and when you do, you can use these opening scenes to foreshadow future events, or act as metaphors or plant hints about future conflicts. Don't worry about that now; that is something for much later.
For now, just focus, one link at a time, on a kind of chain reaction, like dominoes falling. A conflict for a character is resolved by their actions and taking steps, but the consequences create another conflict, to be resolved but create a bigger conflict. Force the characters to interact, and conflict. Write what they would do then, what is in character for them? Don't force them to adhere to your preconceived notions of what should happen. But also, don't let them walk away for long.
To this end, a writing device called The Crucible is very handy: The nature of the conflict means the characters cannot really just walk away from each other or the conflict; the stakes are so high they have to solve it.
Without a crucible, you must rely on strong character traits or extreme circumstance that would make a character endure suffering rather than violate their own belief system. Joe will risk his life and die before he abandons the search for his sister. Mary will literally kill her rich child-molesting ex before she lets the court give him her daughter.
Discovery writing will discover your plot. It is still important to understand plots and ACT structures to know how stories progress: This will help you see what you are discovering, and then refine it. Things cannot escalate forever, sooner or later your characters will reach breaking points, ultimately they will fail or succeed.
The End: The biggest problem with discovery writing tends to be the endings. To fix that for myself, I begin with some rough ending in mind, not prose but notes on how it must end. Whenever my characters start taking actions that will prevent that ending, I have to come up with a better ending, or scrap what I wrote and have them make different decisions consistent with my notion of the ending. Thus far, I typically scrap two or three endings for better endings. When I go back through the book for the second draft, I know the ending and the characters and rewrite for consistency, foreshadowing, a consistent "voice" for the characters. My third draft deals with under-imagined scenes (blocks of dialogue, blocks of exposition). My fourth is for polish; better words, better descriptions, more concision.
The biggest complaint about Discovery Writing I hear is that it is inefficient; I probably write 200 pages for every 100 finished pages. But as an author I am not devoted to efficiency, but quality, and IMO discovery writers produce better characters and better stories. To me, meeting reader expectations for a plot (including being consistent, avoiding deus ex machina, avoiding contrivance) is important, but the exact details are not. Readers come away from Harry Potter loving the characters, and hardly remember the details of the plot. Harry is a hero and wins!
To me, a serviceable plot is important but characters are what make a story loved; we love people more than we love clever situations. To me, discovery writing makes the best characters, that feel the most real, because the author built them that way from the start; letting their actions at each point be a highly plausible action for that character as far as we know that character at this point in the story. The characters end up unforced by the author, and the plot and outcome seems inevitable. I don't force my characters, exactly, I give them traits that naturally put them in conflict with each other, and I use crucibles and the 'butterfly effect' to have small conflicts escalate into larger ones: e.g. She woke up with the power out and late for work; so that could have anywhere from zero consequence to the worst consequences; pick something plausible in the middle that becomes the next issue for her to deal with and can be an escalation: a discovery, a meeting with somebody new, a new task or setback that will lead her into new territory.

I have characters, no plot


Students working on lab software

Question: I was wondering if any could give me some pointers on the issue of having students working on software that's being developed in the lab. What's the standard procedure on this issue? Is there some sort of agreement that's better for the student to sign before he/she starts contributing to this software? Are there any standard conditions that I can use to set up the agreement?
Comment: What kind of issues are you foreseeing? Copyright or confidentiality (or both)?
Comment: Just copyright.
Answer: By and large, taught students (ie, ones who are not paid a stipend or salary) by default retain the copyright to their own work (in contrast to employees, who generally agree to assign it to whoever they are working for). Therefore, you should probably have then sign an agreement to assign the copyright to the lab or university, and you should certainly do this before they do any work. This will ensure you can continue to do what you want with the source code without having to ask permission from the students in question.
For research students, it varies from country to country, so the copyright on their work may be assigned to them, or it may be assigned to the university. If it is already assigned to the university, you don't need to do anything else.
You should probably speak to your university's legal department about this and especially if you do need to write up a contract to assign the university copyright. You may also find this question on programmers.se useful.
Comment: +1 for the last paragraph. I think it's likely that even students who are not employees may be subject to jurisdiction-specific rules that you are not necessarily aware of.
Comment: Right. I think in the US, some universities require copyright assignment for all students? But it is best just to ask someone at your university whose job it is to know these things.

Students working on lab software


Who should be set to authorizing_account when creating an account?

Question: Who should be set to authorizing_account when creating an account using 'cleos system newaccount' on the main net?
Answer: The authorizing account should normally be an account you own and have control over it. Think of it as a "parent" of the new account. It can be used to split your account to several different accounts each one with its own funds and dapp.
Answer: Any existing account can create a new account. Once created, the new account is not owned by or controlled by the existing one. If you need one account to control another, use cleos set account permission after creation.


When is it necessary to consult a university lawyer?

Question: A comment on this answer of mine about e-book lending suggested that it would be better to talk to a lawyer. The situation is as follows: My head of school asked me to explore means of providing our core text books in electronic form to our students. I talked to Library services and IT services and they recommended iPads with standard consumer licensed e-book versions installed. I passed this information on to my head of school, who instructed the school manager to buy the iPads, copies of the books, and other associated hardware needed for running an iPad lending service. Have I, my head of school, or my school manager been negligent for not consulting a lawyer in this manner? Should academics really be consulting university lawyers on a regular basis?
Comment: @JessicaB our students asked for them and the university presumably thinks it makes us look cutting edge. No way they would give us money to buy textbooks for our students, but they didn't hesitate when we asked for money for iPads.
Comment: I know this isn't really about the question, but I'm really curious how you find it worthwhile to pay for iPads to put the textbooks on. It seems to me that ebooks aren't usually that much cheaper than physical ones.
Answer: Well, first of all it's good to check the license yourself. Here you will find that it says that

(i) You shall be authorized to use the iBooks Store Products only for personal, noncommercial use.

So, in this case it wouldn't even have been necessary to contact a university lawyer for the simple reason that the license is incredibly clear. In cases where it isn't you should at all times contact a university lawyer or contact the company in question itself, because in general IT and library personnel are not trained in legal matters (I just dropped by the library to ask). Now a valid argument could be made that it's the libraries responsibility to ask the university lawyer instead of you, but that's up to the mechanisms within your institution, the core issue remaining that one should be consulted somewhere down the line.
As to the question of negligence, I think (as a non-lawyer) you might be attributed negligence for not reading the license yourself, but not for not consulting a lawyer and just asking library/IT personnel. Still, it all depends on who was technically responsible for what and how the question towards the library people was phrased.
Additionally for future reference in case people find this through Google, the license also says

You acknowledge that you are purchasing the content made available through the iBooks Store Service (the "iBooks Store Products") from the third-party provider of that iBooks Store Product (the "Publisher"); Apple is acting as agent for the Publisher in providing each such iBooks Store Product to you; Apple is not a party to the transaction between you and the Publisher with respect to that iBooks Store Product; and the Publisher of each iBooks Store Product reserves the right to enforce the terms of use relating to that iBooks Store Product. The Publisher of each iBooks Store Product is solely responsible for that iBooks Store Product, the content therein, any warranties to the extent that such warranties have not been disclaimed, and any claims that you or any other party may have relating to that iBooks Store Product or your use of that iBooks Store Product.

So not only would you need permission from Apple, but also from the third party selling every single individual book.
Comment: Note that not everything forbidden by a licence is actually forbidden. Some clauses can be overruled by courts declaring them abusive, or institutions may be special cases in the law for certain activities.
Comment: You keep saying "you", who is the "you" you are referring to? Is it the person in IT services, Library services, myself, head of school, the school manager, or the person in the school office who hands out the iPads.
Comment: @StrongBad Whoever was assigned this task was the you I was referring to. Either way, just before your comment I added some in on the topic of negligence.
Comment: @Davidmh: True that, if I remember I will edit that into the answer next time I have access to a computer. Over where I live we indeed have some laws regarding physical books and public libraries (which state funded libraries normally but not always are), but no such thing for digital content, however this could well be different in other countries (although I have never heard of such a thing in any of the major countries).


Is question share popup on question upvote by design?

Question: On each question upvote (but not answer) I'm getting a link share window popped up. Is it by design?
Answer: Yes, and it's happening across the network.
The idea is that you think the question is great (you've up voted it) and now you might like to share it with your followers/friends so the site gains more users, and you get the chance to gain a couple of badges.
I guess the issue is we're at a low question count at the moment so any question becomes "hot" as soon as it's voted up.


Is it ethical to express thanks and gratitude to a reviewer in the reply to the review text?

Question: I want to know whether is it ethical to express thanks and gratitude to a reviewer
in the reply to review text. I feel we should express thanks to reviewers who spent valuable time to review our work.
Comment: IMHO it is more common to thank the reviewer in the Acknowledgments of your article, but of course you can *also* thank her/him in your response.
Comment: @O.R.Mapper: That's interesting. I wonder which fields have *that tight* article length restrictions.
Comment: Once i wanted to add the anonymous reviewer as a _coauthor_
Comment: @just-learning: CS conference papers are often restricted to either 8, 10, or 12 pages. Which invariably means that the last few days of writing a paper are not so much about adding text, but about "fighting" for single lines (line breaks that will result in one page less) by removing content without losing any crucial information. When possibly useful, but essentially redundant information such as the full addresses of authors' affiliations, or DOIs in the bibliography, is among the first things to be removed, there is no space left for polite, but essentially uninformative statements.
Comment: @just-learning: That is probably quite field-dependent. Fields that usually have very tight restrictions on paper length try to reduce everything to the absolute minimum (which, in case of the Acknowledgments, usually means that they contain a note about the grant number and little to nothing else) may rather tend to not do that.
Answer: Yes, how could it possibly be unethical to thank someone? This is very common.
Answer: It is not a question of ethics, it is a question about being courteous. Reviewers spend time to read and comment on your manuscript. Regardless of the type of comments you receive there will be significant voluntary work involved. It is only fair to show some gratitude. One way to think about this is that it is no different from any other type of professional correspondence.
Comment: And you should still thank them even when you wish you could yell at them instead...
Answer: It's very common and standard courtesy. Correctly reviewing a manuscript takes quite a lot of time and is no small effort. And in most cases, a thorough review will help make your manuscript better, so it's not strange to thank someone for helping you improve your work.


If I want to make a project for image patent, what should I learn?

Question: I'm new to Ethereum. Such as title, I want to make a project for image patent. I think it's a PoA project. Now I am studying Parity. And I have tried some tutorial, too. I can run a private chain in Docker with Parity and make some simple transaction now. But I don't know what should I do next. Maybe I need to study about how to write an GenesisBlock,
or how to use Web3?
I'm very confused now. Could you give me some advice or some tutorials?
And I want to know which client is most suitable for my project? There are so many client, I don't know choose which one to start... :(
Thanks a lot!!
Answer: I think this course is really good https://www.udemy.com/ethereum-developer/learn/v4/overview . Unfortunately it's paid but atm it's only 10usd. Disclamer: I'm not related to the guys who did it, I've just taken it some time ago
In terms of what you need to get started, I can recommend:

Investigate some basics about how ethereum works (accounts, ether, gas, web3js). So you can have an idea about how do you want to model your solution. (For example, a super naive implementation could be a smart contract to store a set of (owner address, image hash and timestamp) and a method to allow a user to check if it exists or not and who's the owner.
Setup a test node using Parity or Geth (they are both great clients, you can try Geth as it has a great javascript console to play).
Download Mist wallet and try to play with a test chain.
Learn about solidity which is the most common language used to write Smart Contracts
Check out Truffle. It's a great tool that will allow you to write and test the smarts contracts you create

Hope it helps.
Comment: Wow! That's so detailed! It helps me a lot! I'm studying about Truffle now. Hope I can know more about contracts. Thanks!! :)
Answer: I'm assuming you are trying to put a proof that certain image was created by someone at a certain time by putting it on a Blockchain?
If that's the case, then you should start with how to hash images (Backend of choice) and design a Solidity Smart Contract to put the hash in a Blockchain.
PoA and Parity are on the network type layer and you can worry about that later. Start with testrpc and Remix IDE. Then, you can try interacting with your contracts via web3.js
testrpc: https://github.com/ethereumjs/testrpc
Remix IDE: https://github.com/ethereum/remix
Web3: https://github.com/ethereum/web3.js


Do two compatible tRNA codons bond together?

Question: Can two tRNA with complementary anti-codons link together?  For instance UUU with AAA. If not, why not?
Comment: @Ashafix has given an answer to your question which is technically correct, although it relates to artificial conditions rather than cellular ones. Perhaps this is what you are interested in. However I wonder whether you were thinking about such interaction competing with the interaction of the tRNA anticodon and mRNA codon in the cell. If so, you should make that clear so that we can provide an answer addressing that point.
Answer: Yes, tRNA can form dimers. For example it was shown that E. Coli tRNA GCC forms homodimers, i.e. two identical molecules interact with each other. In this case the dimerization occurs between the anti-codon loops (what was probably meant with UUU and AAA).
References:

Sequence and structure of naturally-occurring tRNA transcripts and site-directed variants are significant barriers to forming oligomers beyond dimers.
(Harold S. Bernhardt, Warren P. Tate, Advances in Bioscience and Biotechnology, 2013, 4, 1-16 ABB)
Anticodon-anticodon interaction induces conformational changes in tRNA: yeast tRNAAsp, a model for tRNA-mRNA recognition.(D Moras, A C Dock, P Dumas, E Westhof, P Romby, J P Ebel, and R Giegé, Proc Natl Acad Sci U S A. 1986 Feb;83(4):932-6)

A naturally occuring mutation, A3243G in human tRNA(Leu(UUR)), causes dimerization via a motif which is not in the anti-codon loop.
Reference:

Wittenhagen LM1, Kelley SO., Nat Struct Biol. 2002 Aug;9(8):586-90.,
Dimerization of a pathogenic human mitochondrial tRNA.
Comment: Link-only answers are generally not acceptable on Stack Exchange sites. The link may change or become unreachable in the future, and without a summary of what the link contains this answer would be useless. Please summarize what is in the link (**don't** just copy and paste) and use the link solely for reference. If you remove the link and the answer cannot stand on its own, it is not a good answer.
Comment: Thanks for the info! I will update the answer later. I thought that giving a reference to a published scientific article would be safe even if the link is dead.
Comment: The reference is fine, and while I only skimmed the article it looks like it may be useful for the OP. We (as in the Stack Exchange community) don't like link-only answers as the link may change or die, but also because it requires you to go to another site and attempt to interpret the research (in this case), which may not be possible for some readers  given the level of their scientific education. Just summarizing the abstract should be fine. One question though - it seemed like the paper only talked about dimers, and couldn't find multimers. You may want to change your answer.


Which of the TLS protocol versions are secured for enabling in Internet Explorer

Question: Which of the versions of the TLS(TLS 1.0,TLS 1.1,TLS 1.2) should be enabled in the Internet Settings of Internet explorer for access of HTTPS sites and secured broswing. Is only one of them enough or which of these are better ones.
Answer: Technically, you should only enable TLS 1.2. Unfortunately, that won't work so you'll need them all checked at the moment. This is supposed to tell a server you want the highest they'll support. Even then a few broken HTTPS servers will fail but it should be very rare.


Late night buses from Helsinki airport to Turku in December?

Question: I'm traveling in December.  I arrive at Helsinki airport (HEL) at 9pm and would like to get to Turku as soon as possible.  What is the latest night bus available?  Alternatively, how early can I take one the next morning?
Comment: From a quick exploration on Google Maps it appears that buses run all night and stop at Terminal 1 and Terminal 2, though Google seems to want to tell me to walk 550m to a farther stop (not happening).
Answer: According to the Matkahuolto.fi central bus schedule search, the last connection from Helsinki-Vantaa airport T2 to Turku leaves the airport at 22:50, arriving in Turku at 01:30.  (There's also an earlier bus at 21:50 which you'll likely make if your flight is on time.)  Both also serve T1 (leaving 10 minutes earlier) and involve a change of bus at Espoo's Ikea along the way, but the buses are run by the same company (Pohjolan Liikenne) as a guaranteed service, so this should be pretty painless.
Should you miss the 22:50, the next services are at 0:30 AM, 01:25 AM and 03:45 AM.  So you're definitely not going to get stuck at the airport for the night!
There are also other options if you detour via central Helsinki, eg. transferring to a VR train at Helsinki Central (last departure 23:00, but arriving slightly earlier at 01:00) and the supercheap Onnibus service (last bus from central Helsinki at 22:45).  But if it's your first time in Helsinki and/or you're tired after a long flight etc, the direct bus is the easiest option.
Comment: i could only find the information to August 2015 - do you live nearby to know that it is the same or similar in December?   (I'm traveling on 19 December).   Awesome reply and really fast too - thanks mate, really appreciate it.
Comment: I don't think they publish schedules that far in advance, but that bus service has been running through the night as long as I can remember. The exact times may change but they're not going to cancel it.
Comment: Thanks so much - really appreciate your insight jpatokal.  cheers


GraphQL mutation or query, how to target specific site?

Question: Is there a restriction on graphQL that only allows it to work on the primary site?
My system has for unknown reason switched primary (and I can't change it back due to a bug), and ever since then my graphQL mutation fails claiming there is no such entry (switching primary in my dev env fizes the problem).
I figured that the base URL of the api request controlled which site it was querying, but that doesn't seem to be the case either?
I'm using the mutation save_sectionHandle_entryTypeHandle_Entry(). The ID I send in seems to be the same across different sites, so I need some way to distinguish between them to edit the right entry it seems, or in my case, allowing the call to even find the entry...
Answer: Aha, it was merely sending in siteId as well when updating, in addition to id. If siteId is missing, it will default to primary site it seems.


Should we take a meta consensus as site policy

Question: Meta is used to decide site policy how should we use the results of questions? Is the highest voted answer immediately taken as a rule or is it a suggestion? If it is a rule then what consensus is needed to set a new rule? Would a vote of 1 on an answer be enough or does there have to be a large number of up votes? How large is that number?
Answer: It depends, and it's necessarily vague.
Suppose a site's community, via meta, voted overwhelmingly to, say, outlaw question closure.  That would be interesting, but it wouldn't change anything.  At the other end of the spectrum, if a site's community votes to change the name of its chat room, or to define a tag synonym, or to reopen a question, there's probably no reason not to do that.
A community's custodians, including its moderators, cannot have their hands tied by a meta consensus if there are reasons to not implement it.  But, by the same token, it would be unwise to ignore that meta consensus -- something is driving it, and chances are there's an underlying issue that we need to address.  So maybe it's not even about the specific proposal; perhaps that's a symptom of something else and we need to talk about that.
Sometimes meta is data not democracy.  Other times it's democracy, and if there's clear consensus and no objection on a site-internal matter, then it'll probably happen when meta activity has died down (people have had a chance to object) and somebody gets around to doing whatever the thing is (merge those tags, update the sandbox rules, start the monthly challenges, whatever).
I can't give you a set of rules.  I think our community has been pretty good at both reaching consensus and reaching consensus that we've reached consensus.  If you see something that seems to be languishing but also seems to have consensus, bring it up somehow -- comment on the post, bring it up in chat, etc.
Comment: Ah, but have we ever reached consensus about reaching consensus on having reached consensus?
Comment: @Frostfyre I don't think we have reached consensus on the necessity of reaching consensus about reaching consensus on having reached consensus. I propose a Meta debate to clarify the need for such consensus, but because there is as of yet no consensus on such a need, maybe we need to discuss that latter first.
Answer: As Monica already said, it depends. I've certainly seen it go both ways on Meta Stack Overflow and Meta Stack Exchange...
Some proposals are incredibly popular, yet never really get full support or implementation, while others seem to make the grade and are eventually added as policy.
One workflow that seems to work well for a lot of issues and one that I support would look something like this:

Ask a general discussion question to see if the community recognizes that this is an issue that needs addressing.
If it looks like people generally agree that there's a problem ask a question about potential solutions.
If there seems to be a well supported solution escalate to a feature-request or  faq-proposed
If the feature gets implemented or the faq added then you have solid confirmed consensus.

It's a little harder to gauge community consensus here than it is on some of the larger sites where you tend to see a little more Meta traffic... I think we should be careful to keep in mind that some of our higher voted posts here on Worldbuilding's meta only tend to see a handful of votes and may not always be fully representative of the larger community. Honestly I think we could do more to encourage people to get involved in the process, but even then a slow steady work flow should keeps things on track.
Perhaps adding  faq-proposed to the featured on Meta list could draw some more eyes before we move forward with new FAQs?
Comment: I think #1 and #2 can be readily combined into one, with just some careful phrasing of the question. For example, instead of first asking "is X a problem" and then later asking "what should we do about X", consider asking both at the same time on a form like "how should we handle X". If you phrase it in a way that allows answers including "X is perfectly fine" or "X should be killed with fire and brimstone", then the community can express their feelings about the subject *and* propose ways to handle it at the same time. This also ensures that you don't get different people voting on the two.
Comment: @MichaelKjörling I thought about that, but often people trip over that careful wording part. Ideally I would prefer to see the two combined.
Comment: I don't see any problem with being explicit about allowing both, if that's preferred.
Answer: What if the highest voted answer has 3 votes?
I think there should be some sort of minimum (overall) participation before a policy decision is made and perhaps some special tag for "imminent policy change" that we can monitor.
When there is such a policy change vote on the board, one of the answers could be "ABSTAIN", so we can at least see people have seen the imminent policy change and don't care -- thus knowing we have reached a sufficient level of exposure to conclude that a consensus has been reached.
Comment: The views count on the question can be useful there. A question where the highest voted answer is voted +3 and the question has ten views probably can't be taken for much; a question that has a views count in the thousands can probably be taken to mean *something* even if the votes are few and far between. Exactly *what* it means would obviously be very context-dependent.
Comment: *"To be stable, change should require at least 60% with hundreds of voters; to reduce the likelihood of a majority reversal."* I kind of doubt even Meta Stack Overflow has hundreds of active users, let alone what we have here.
Comment: @MichaelKjörling It becomes a question of political philosophy: What does it mean we should do, if nobody really cares enough to vote? Is that equivalent to assent either way? Who knows. Close ties, likewise: Suppose irreconcilable answers are 999 to 1000? Mathematically, implementing either option is unstable; Majority opinion could change by 3% or more within a month (esp. if one is implemented and some outcomes unexpected). But we cannot poll and change every month. To be stable, change should require at least 60% with hundreds of voters; to reduce the likelihood of a majority reversal.
Comment: @MichaelKjörling I am unaware. If that is the case, we should have 30, or if that is still less than 5% of the pop, perhaps move to the Student's t-Distribution and increase the % of votes that constitutes a super-majority. In any case, I think the gist of my argument holds; that probabilistically speaking, a vote to make a change should be expected to remain stable for at least a year or so. Votes and views give us the probability of someone holding a categorical stance, and what is too evenly divided to be long-term stable, or if too many don't care enough yet to warrant a permanent change.


Clipping line layer to every feature of polygon layer in QGIS?

Question: I have a line layer (roads) and a polygon layer which represents districts/counties. I want to clip the roads according to every one different county. That means that I must repeat the procedure sixty times as the total count of districts is 60. (I must select one different district (feature of polygon) every time and then Vector -> Geoprocessing -> Clip). Is there any possible way this procedure to become automatic? I work in QGIS (and ArcGIS).
Answer: You can create a model from the Processing Toolbox which allows you to automate a number of tasks.
You can create one by going to the menubar:
Processing > Graphical Modeler...

From the Inputs tab (shown in the red box), you will need two Vector layer parameters (shown in the blue box) for both your line and polygon layers.

Then from the Algorithms tab (shown in the red box), type in "clip" to search for your Clip tool.  Then select the relevant options:

Don't forget to type a name for the model and group shown in the green box. Save it and load the Processing Toolbox interface which can be enabled from the menubar: Processing > Toolbox.
Then find your model from the toolbox which should be under Models (or you can type in the name of your model in the search box). Now when you run it, click the green round-arrow button next to the polygon input layer to iterate through each polygon feature:

When you run it, the road layer will clip onto each polygon feature and the results will be loaded.

Note: I have tested this on a simple example and it worked fine. Tested with QGIS 2.16.0-Nødebo with Processing plugin v2.12.2, Win7 64-bit..
Comment: Yes, it worked. Thaks a lot for your detailed instructions. Is there anaway the names of these output files (clipped .shp) to be taken of a specific field of the polygon layer?
Comment: Most welcome, glad it did! Hmm, only through the **Batch Process** of the modeler I believe, however this works on a layer-by-layer basis so will not iterate through each feature. I think the only way would be to create **custom script** and write some python logic to loop through each output, get the value from a specific field and rename the file.
Answer: Python would be the best way to do this. If you perform one clip you can copy the python snippet from the Geoprocessing results and 'build' code snippets for the remaining 59 using concatenate in excel
Comment: What is the python snippet from the Geoprocessing Results? Do you refer in ArcGIS environment? Could you give more details? Thanks in advance.
Comment: Yep sorry, within ArcMap. If you run one then go to Geoproccesing > Results you will see your completed clip function. If you go to right click and copy Python snippet it will give you the code that was used to perform it.

I usually use command prompt to generate a list of files in a directory to get the list of shapefiles (copy into excel and remove any non .shp).
Answer: Using ArcGis, no programming needed:
1 - Apply intersect, so all your network will take a unique cod for each district.
2 - Open model builder, under menu insert chose "Iterators\Row Selections"
3 - Right click on row selection and create two Model Variable (1-Input Table 2-Group By Field)
4 - Double click on Input table and chose created shapefile from Intersect command.
5 - Double click on group by field and chose the unique key of districts.
6 - open toolbox under Data management\Feature chose copy feature drag and drop it into model space.
7 - Link your selected feature of "Row Selections" with "Copy Feature" as input feature.
8 - On output chose your geodatabase where u want to save your shapefile dont forget to rename it "....your path.gdb\yourname_%VALUE%". %VALUE% is very import to rename all your new shape file with your unique code.
Your model would look like.
Comment: I tried this but it returned only one shape file instead 62. The only one difference is that I didn't run intersect as there is a field (in roads shape file) which contains the name of district in which every road segment is located. Thanks in advance.
Comment: No worry about intersect was just for taking the district code. I just tested it and it works fine, the logic is simple "Group by code than export grouped row to new feature". Be careful on field you choose for group and be sure for the last Output it should be renamed "yourname_%VALUE%" if dont the next shape will replace the past, so iterating all district you will take just the last district couse  they were raplaced.
Answer: To add on to Joseph's answer, in newer versions of QGIS (I'm on 3.10) to use the "Iterate" button you need to use "Vector Features" in the input instead of "Vector Layer"
Related Question: Modeling iterative processes in QGIS 3


How do I stress test a website?

Question: How do I stress test a website by logging in 200+ accounts at the same time?
Basically I have my website deployed on AWS and I would like to make sure that it will be able to handle 200+ users load on that day. I understand I can enable automatic scaling but I would like to know if it's possible for one instance to handle it.
Answer: Perform a load-test on the website:

Write a load-test script
Ramp-up users from 1 to 200
Let them click around the website with the script
Monitor

Response times
Error on backend and frontend
CPU/Memory/Disk usage

If the response times stays the same for all users, or at-least comfortably low, it probably will be fine.
If your script doesn't have a wait time between actions and you keep hammering the website continuously it could be that 200 concurrent users represent 2000 actual users or more, because real users click then read and then after some seconds click again.
Some common tools to load-test with:

https://jmeter.apache.org/ (Java)
https://artillery.io/ (JavaScript, used for API load testing)

Do also read the AWS Testing Policy to prevent your account to get blocked for abuse.

How do I stress test a website?


Understanding full set of sections as in Katz-Mazur

Question: I was reading this question, specifically Brian's answer. In particular I am having a bit of trouble digesting the following sentence:

Being a "full set of sections" of $Z/S$ is something which is sufficient to check using the constituents of a single open affine cover of $S$, and also a finite generating set of the coordinate ring of $Z$ over each such open.

Unfortunately, in my mind there are several ways in which to interpret this statement. Let's assume that finite generating set refers as a module (not as an $R$-algebra). One interpretation that I tried and gives me trouble is the following:
For simplicity, take $S$ to affine, $\newcommand{\Spec}{\text{Spec}}$ $S=\Spec(R)$, and $Z=\Spec(B)$ even with $B$ free as a module over $R$, say of rank $N$ and a basis $b_1,\ldots,b_N$; then I don't think the condition for full set of sections (say in the form (1) of definition (1.8.2) on page 33 of Katz-Mazur) for $b_1,\ldots,b_N$ implies it for every $b\in B$. When trying to prove it, roughly speaking, I ran into the problem that "additivity fails", i.e. if (1) holds for $b$ and $c$, then it doesn't hold for $b+c$ (if this were usual linear algebra over a field, I believe this translates to the fact that $b$ and $c$ viewed as linear maps on $B$ via multiplication, have different eigenvectors).
However, I didn't completely disprove it. It may be possible that the algebra structure on $B$ (or even the Hopf algebra structure) somehow guarantees that all is good? (doesn't seem so to me though, even if the matrices of $b$ and $c$ commute since $bc=cb$).
Or maybe it was meant that even though we work Zariski-locally, say on $\Spec R$ we still require the definition of full set of sections for any $\Spec R'\to\Spec R$. (i.e. I am allowed to pass to $R$-algebras). In this direction, alternatively (and maybe that's what Brian meant, but it doesn't seem exactly 'Zariski locally' anymore) one can pass to the "universal element" $f=\sum T_ib_i\in B\otimes_RR[T_1,\ldots,T_n]$ as on page 38 of K-M and then indeed, it suffices to check condition (1) (or (2)) for this universal element, yielding a big identity but in finitely many variables.
Could anybody help clarify this please? As a bonus, I would appreciate some intuition as to why the condition for full set of sections is so "linear" (in my not-very-developed understanding it seems to barely touch upon the algebra structure of $B$ and almost not at all on the Hopf algebra structure) - it seems a bit strange that it encompasses so much "geometric" information (at least the way I think of level structures).
Thanks!
Answer: The condition that "$P_1,\dots, P_N$ is a full set of sections on $Z/S$" is local on $S$.
For the case you mention in the first interpretation, let $k$ be a field, $S = \operatorname{Spec} k[\epsilon]/(\epsilon ^2)$ and $X = \operatorname{Spec}\mathcal{O}_S(S)[\epsilon ']/(\epsilon'^2)$. Define $P_i:S\to X$ as $\epsilon'\mapsto 0$ for $P_1$ and $\epsilon'\mapsto \epsilon$ for $P_2$. Then, $b_1 = 1$ and $b_2 = \epsilon'$ are a basis of $\mathcal{O}_X(X)$ over $\mathcal{O}_S$(S) whose norms are written as $b_j(P_1)b_j(P_2)$, but the same thing does not hold for $1+\epsilon'$. This example was taken from Takeshi Saito, "Fermat's Last Theorem: The Proof."


Why does iPhone 4 lose its VPN connection on sleep or screen lock?

Question: I've setup a VPN connection using AnchorFree.com on my iPhone 4 which works great, the issue I have is when my iPhone goes to sleep or screen locks the VPN connection appears to auto disconnect and doesn't reconnect unless I manually make it. I saw a thread here on apples forums confirming others are seeing this issue but no real solution.
Comment: Same here. iPod touch. Very annoying.
Comment: A question without question. Amazing ;-)
Answer: I don't know if it will really help you, but the only way I see to walk-around this problem is to set the System Preferences "Auto Lock" to "Never". This will keep you connection alive.
I would do this before every remote work session. Then, reset it to 1 minutes, you're done with it.
Comment: That seems to be a double security hole. First your iPhone won't lock, and then the thief will also have access to the VPN.
Comment: Have you ever used your iPhone as a hand calculator while working for instance ? If you don't turn this autolock during that time, you'll become mad. If there are right : there should be an app for that ! An app that switch the auto-lock on at startup, no ?
Comment: Yes others have mentioned this but I don't want turn off lock mode because it's inevitable that I will forgot to turn it back on leaving me at risk.
Comment: or rather, a way to declare certain apps as "not security-relevant". They could then be accessed without unlocking the phone. The whole thing opt-in, of course.
Answer: It's most likely a battery-saving option. If only it would do that with Wi-Fi connections.... :(
Being connected to a wireless signal besides 2G data eats the battery like mad.
Answer: I have just signed up for VPN service this week and I have been having the same problem. I use it to watch Netflix and listen to Pandora from out of the country. I have been playing around to see if I can get the VPN to stay connected; so far I found a solution that has been working for about an hour or so now.
I have a jailbroken iPhone 4 and I have installed backgrounder from Cydia which keeps programs running even when closed or when the screen is off.
After installing this, I installed Pandora from the App Store and, after launching it, I held down the home button to background it.
So far, it seems to be working because Pandora uses my connection and if I keep it backgrounded, it will prevent the VPN from disconnecting.
I have only been using it for a couple of hours so I'm not sure how good of a permanent solution it will be.


Difference between "seems like ...", "sounds like ..." and "feels like ..."

Question: I want to know if there are differences between the three following sentences, since for me they all have the same meaning:

It seems like an adventure.
It sounds like an adventure.
It feels like an adventure.
Answer: Yes I believe that there are differences.
"Sounds like" implies that the evidence is just words, usually spoken but could be written. "Seems like" could be used with any sort of evidence.  "Feels like" is similar in meaning to "seems like", but suggests a higher degree of subjectivity - like it feels that way to me, but might feel differently to you.
Answer: I agree with David, however in certain situations the actual meaning or sensory route associated with verbs can simply be used to convey degree, for example te degree of truth perceived in the knowledge of the adventure. As such it can be said that

It feels like an adventure

is more definitive than

It sounds like an adventure

and so on in the same order as the sentences were presented.
Answer: At least as I would use it "sounds like an adventure" implies that you've heard or read a description, and imagine that what was described would (probably) be an adventure.
By contrast, "feels like an adventure" implies actual (current) experience, and considering what your experiencing adventurous. While I can certainly believe some people would use it to describe their reaction to a description, I would consider it slightly inaccurate in that context. "Feels like it would be an adventure" would probably be more accurate in that situation.
"Seems like an adventure" could carry either implication, depending on context. In reply to a description, it would be synonymous with "sounds...". In a journal entry from somebody hiking in the Amazon jungle, it would probably be synonymous with "feels like...". Without context, I'd say it's more likely to be synonymous with "sounds like...".
Answer: The expression "it feels like" is, now (06/03/2013), being used too often in the ways that "it seems like," once was used.   It feels like this trendy overuse of "it feels like" does effectively imply "a higher degree of subjectivity" or, at least, ownership of the conveyed perspective, for now.  But, soon, this trendy way of talking, by continued overuse and a broader range of application, will reduce all "its" to a common state.  While "feels like," "seems like" and "sounds like" have long been interchangeable, the current trendy use of "feels like" is being applied across the board to things or "its" that relate to both feelings evoked and personal perspective or observation.  For example,
"Feels like the pitchers curve ball is dipping below the strike zone."
is an observation that really does not imply emotional investment.  Whereas,
"Feels like everyone's picking on me."
is an observation that clearly entails emotional investment.
Not all observations or perspectives entail emotional investment, so I'm wondering about the need to imply feelings.  I'm also wondering why we need to imply, stamp or clarify (even if efficiently) that our observations or opinions are our own by using "feels like" in place of "seems like."  True, sometimes, using "feels like" would be hugely helpful as, for example, when a person seems to state an opinion as though it was fact.


Sorting Flickr photostream

Question: I have been using this great tool (http://sortmyphotostream.michael.tyson.id.au/) to sort my Flickr photostream by the date of the photo rather than the date uploaded. It seems to have disappeared recently. Are there other tools available that will do this?
Answer: There is an app that claims to do this (I haven't tested it myself):
Flickr photostream update - A cool app to sort your photos by taken date instead of upload date
http://flickrstream.webzardry.com/
Comment: Thanks for the link. I remember now seeing that app when I first searched for a solution last year and found Michael Tyson's app. It isn't quite as good because it won't sort photos created before the Flickr account was create (less of a problem for me now) and only does 100 at a time (more of a problem for me now). It is a good alternative though and got the job done, thanks for the answer!
Answer: I'd also noticed the web page was down, so left a message on Michael's blog last night and he's fixed the DNS issue that was causing his SortMyPhotostream page to be unavailable.
If you try it again now hopefully you'll have access again.  See last few comments on his blog post.
http://atastypixel.com/blog/sort-your-flickr-photostream/

Sorting Flickr photostream


Nikon MF-29 date back usage and imprint location

Question: I've pulled my F-100 out of the cupboard to use this weekend and remembered that it has an MF-29 date back.  However I can't remember exactly how the date back works, neither do I have a manual for it, and can't find any information about the MF-29 online (albeit there are some sketchy websites that purport to have a PDF for download)
What I do know about the MF-29 is that it is fairly simple, and there are only 3 buttons on it:

Mode - Cycles through the "display" modes of the unit (Off, and 4 date/time formats - YYMMDD, MMDDYY, DDMMYY and DDHHMM)
Select - Is used to select the current date part (Day, Month, Year, Time) to change
Adjust - Is used to change the selected date part in order to set the current date/time.

And there is an LCD that displays the data that will be imprinted on the film:

Off - (no data imprinted) displays as "------"
YYMMDD - Year/Month/Day, displays as (EG for today) "201127"
MMDDYY - Month/Day/Year, displays as "112720"
DDMMYY - Day/Month/Year, displays as "271120"
DDHHMM - Day, Hour/Minute, displays as "27 2:15"

There is also a bar on the LCD that indicates that a date will be imprinted on the film (linked to the "Print" text printed on the date back itself), and a an indicator that identifies the currently selected date format.  See this example image for the YYMMDD format (the long bar in the top right indicates that the data will be imprinted):

What I can't remember about the MF-29 is where on the film the date information is imprinted. I thought that it was interspersed between frames (I used to have an F-80 with dateback that did that), but in the F-100 manual it states for Custom Setting 18:

18. Data Imprint (year/month/day/hour/minute) on Frame #0
Options:
0 - Disabled (initial setting)
1 - Enabled
With optional Data Back MF-29, data (year/month/day/hour/minute) can
be set to be imprinted on frame #0.  To imprint data on frame #0 only
and not on frame #1 on, cancel the data imprint on the MF-29 after
film is automatically advanced to the first frame

But this implies to me that the data is imprinted on the frame itself.  (and that you can get it to start imprinting before the first user frame - EG frame #0)
So where on the film does the MF-29 imprint the data, and are there any examples online that show this information?
Answer:
So where on the film does the MF-29 imprint the data, and are there any examples online that show this information?

The old listing at B&H says it imprints it within the frame.
So does an old listing at KEH
This discussion thread at Photrio comes to the same conclusion.