Which one is good Java or Json in GWT client?

Question: I have a GWT client project and REST is my web service. I have a class Student and I want to save it in data base which is in web service. I am converting student to json and sending to Server. Is it right method? My doubt is In client side am I have to use Json object instead of Student?(because it will not need any conversion for sending to server) And if i am using Json it will give good performance like java?
Comment: If you are still confused between `java` and `javascript` and  `json` then probably its not the right time yet to ask this question
Answer: Json (in this case) is used to serialize your student object. This means that it is used to pick out the parts of your student object that differentiate it from other objects (such as name, age, sex ...) in order to transport this information elsewhere. If you won't be needing the student object server-side then fine, just dump it into the db. On the client side however you should have a class or method that creates json objects from student objects and also creates student objects from json objects. Do not treat a json object as a student object
Answer: JSON or JavaScript Object Notation, is a text-based open standard designed for human-readable data interchange.
So if you are using it to transfer data between your rest service and GWT front-end then its fine.
To save Student JSON notation you can convert it to POJO using many available library like jersey or GWTJsonizerand can store easily that to DB.
To summarise. JSON and Java object are two different things, use JSON to transfer information,
convert JSON to java object and use this java object for further processing in you web service
Comment: My doubt is I want java class to bind with GWT components(Student). Can I create a model using json for binding with Gwt components instead of student.? Means is it right if i am making a model using json like student?


Avocado plant leaves drooping ** still in water**

Question: The leaves on my avocado plant are drooping, the difference is, mine is still in the water cup I used to pop the seed. I was waiting to see wilting or burn on the leaves to indicate the time for transplant but the leaves are still green and there is new growth. however, this last week the leaves are drooping and looking sad.
It's kept indoors near heat and I use blue spectrum LED grow lamps (Nov in washington).
Possible problems:
Time to transplant?
too much light? I often leave it 24hrs/day
algae or fungus? its kinda slimy down there at the roots. I refreshed the water a couple times but no help this time.
Could it be the tap water? should I use distilled or bottled water?
Help! I am several months into this thing. Thanks
Comment: Don't forget the red light: http://faculty.southwest.tn.edu/rburkett/GB-1%20p24.jpg
Answer: Gus, my guess is that at some point your roots ran out of oxygen in the water. Here's a story - you have a fixed amount of water and suppose it is well oxygenated, unlikely but possible. While the plant root volume is small the air lasts a long time, but as the roots grow larger they eat that O2 at an accelerating rate. Then a point comes where there is no more and root tissue starts to die. When this happens in soil there are various organisms in the soil to help deal with that situation, but in plain water you are out of luck.
If this is right, and be aware there might be alternative narratives, the conclusion is to get the plant into fresh aerated and watered soil ASAP. We know that due to its soft leaves the avocado can get out of balance with its roots very quickly, so no delays. It might look sad for a while, but treat it well with moist but not wet soil and you might come out on the sunny side. Try very hard to do as little damage as possible to the root system when you transfer.
Comment: Thanks for the insight. It is possible as there has been new growth at the top recently. Perhaps the new growth is causing more consumption. seems to happen all at once
Comment: It only takes a tiny bit of oil to interfere with Oxygen crossing the air/water interface. Changing water regularly can help with this.


Are ties still worn with suits?

Question: I live in Melbourne Australia, and one day I wore a suit and tie to work because I had to do my corporate photo. Whilst I was having lunch I took a look around (this is in the city) and I couldn't see one solitary person other than myself wearing a tie with their suit, out of literally hundreds of people (this wasn't Friday either). There were people with suits, but they didn't have ties. I then felt like I was sticking out like a sore thumb because I was wearing a tie. Although the instructions were to wear a tie for the photo shoot, I suspect they had not been updated for a long time, and it may have been acceptable not to have a tie. So my question is, are people still wearing ties with their suits? Or now that big corporations are moving to be more casual (at least here in Australia) are ties a thing of the past?
Comment: Depends on the country, In Japan the majority wears ties. And I heard( I am not Japanese but I am in Japan)  that " You can never overdress ". If you don't know how formal it is, better be more formal then less.
Comment: Yeah, the trend in Australia has been to move away from the business suits and ties - it depends a bit on local or office culture, but the typical clothing is smart casual these days: https://www.google.com.au/search?tbm=isch&q=australia+smart+casual+men
Answer: I have seen both, but it usually depends on the crowd.  Like around Gov. folks ties seem like a staple, but around more commercial the classic button up shirt with a blazer is in style and even jeans with that sometimes.  I think it varies with country and business type too, so I'd expect a variety of answers to this one.  In general though I think the more formal business attire is being relaxed from where it used to be.
Comment: Gov. in particular seems a land of extremes: either suit and tie, or no suit at all. Plenty of casualwearers there too.

Are ties still worn with suits?


Austria: partial expenses refund for training / education courses

Question: I've heard that in Austria (Tirol) the government provides a 30% refund for training / education courses useful for work. Is it true? Where can I find more details?
Comment: Formative/Formation do you mean formal?
Comment: @Karlson: something like a language course or development course or something like that. I've edited the question.
Comment: For starters, "Bei Selbstständigkeit" means "In case of self-employment". Are you self-employed?
Comment: @GaëlLaurans: thanks for the translation! No, I'm not. Now I will edit the question for acknowledge people who expatriates in austria of this refund possibility.
Answer: Yes, it's correct. Here it's possible to read the additional information: link
It's also possible to fill the module online but it's strictly mandatory to fill in the form in 15 days from the beginning of the course. So read the information carefully. According to other collegues' experiences, the refund should arrive in a short time (1 month?) after the end of the course.
In Austria, also, some kinds of expenses for work (i.e. training course) are also deductible from the taxes at the end of the year. So I think, but I'm not sure, that it's possible to deduct from taxes the remaining expenses.
To make an example the cost of my German course was 280€. I will get 30% refund in some months, about 85€. At the end of the year I will write in my tax document that I've payed 195€ for a training course and ask the government if I can get back other money.
My impression is that the burocracy here works. You can also fill a lot of forms online (not as many as in England, but not so bad as in Italy).


Software to play music through two audios systems on two different computers in the same house!

Question: I have two audio systems on two separate computers and I want to be able to play them with the same songs but synchronized and without having any lag. Can you help me with software (Windows 7) that does just that ?
Answer: You can use VLC to broadcast a scheduled list of media, (audio and video), onto your LAN, see here, then each computer that you would like to listen on can use either vlc, media player or any player capable of connecting to a network stream to "play" the broadcast.
NOTE: They will never be 100% in step due to a number of issues: network rates, buffering, etc., but even if they were if you are a location where you can hear both they will sound out of step unless you are exactly the same distance from both, due to the speed of sound delays.

The server should work on any of Linux, Windows or OS-X
You should be able to play with any network device that has the capability to consume such streams, i.e. Linux, Windows, OS-X, iOS, Android, RaspberryPi, Internet aware TV or Stereo.
VLC is free (Gratis and FLOSS)
Answer: VLC is probably the best option if you simply play a track or a movie. However, if you want to send any audio to other computers I don't think this can be done with VLC (could anyone confirm or refute?). For that use you might be interested in Airfoil:

Windows and Mac
non-free: 25 USD (noise is overlaid on all transmissions longer than 10 minutes in the free version.)
Send any audio from your PC to AirPort Express units, Apple TVs, iPhones and iPods Touch, and other PCs and Macs.
Comment: I asked the question there: [Streaming music across your local network with VLC: choosing which application I want to stream the music from?](http://superuser.com/q/828600/116475)


weather causing power loss

Question: Why would my engine lose power when the weather temperature gets warmer. While driving the vehicle will not have as much power when it gets warm or hot.
Comment: Can you give us some information about the car (year/make/model/mileage)? Also, if you could give us an idea of what you mean by warm/hot v. what cold is? Someone in Alaska will surely have a much different idea of what hot/cold is compared to someone who lives in Egypt. Do you usually fill up at the same place? What maintenance have you done to the vehicle. All of this stuff will help us help you. :D
Answer: To some extent, all combustion engines lose power in warmer conditions. Cold air is denser, and contains more oxygen, so more fuel can be burned, resulting in more power.
Is it an incremental change in power, or do you notice that over a certain temperature, there is a large noticeable drop in power?

weather causing power loss


Why is luggage required to be loaded in containers?

Question: Luggage is loaded into containers, in Wide Body airliners (as mentioned here). Why is this required to be done? Why don't they simply keep the luggage in the luggage compartment? Why is loading the luggage piece-by-piece time consuming, and at the end, in second photo mentioned there, the luggage is being loaded piece-by-piece. What is that?
Comment: The link in this question already explains almost all points of the question. The only thing possibly unanswered is why some pieces of luggage (shown in the second photo) were _not_ put in ULDs. The airline can easily manage a _few_ pieces of luggage handled this way (compare the two photos: five ULDs on one conveyor vs. six individual pieces on the other!). But the added cost of handling _all_ the luggage that way is well worth avoiding.
Comment: @DavidK The photos in the linked answers clearly show two different planes, not one plane being loaded partly with containers and partly with loose baggage. The first is a Japan Airlines 747 (actually being unloaded); the second appears to be a 737, in the livery of some airline that I don't recognize.
Comment: @DavidRicherby Good point; [according to information from Boeing](http://www.boeing.com/resources/boeingdotcom/company/about_bca/pdf/CargoPalletsContainers.pdf), passenger 737s don't use ULDs. Those are not just gate-checked bags, then. As far as I can tell, however, the answers below did not pick up on the difference between aircraft.
Answer: The central cargo hold is usually pretty big and open, if cargo was placed in loosely then it might shift in flight which can cause the center of mass to shift or damage the walls of the hold. Putting them in containers and fixing those down will prevent that.
The containers can also be weighed before hand and their position set to ensure the center of mass ends up where it should be. With loose cargo the pilot would need to rely on the intuition and experience of the loaders to ensure that they don't put all the heavy stuff on one side.
Loading loose luggage requires that the loader in the cargo hold handles each bag while stacking them. The hold also needs to be full enough that the luggage can't shift around.
The smaller forward and rear cargo holds (or on smaller planes) can still accommodate loose luggage (or more precisely they are too small for the containers to fit). They will also have netting to provide barriers against shifting.
Comment: If you want to see some tragic footage of what happens  when a load shifts: https://www.youtube.com/watch?v=lksDISvCmNI
Comment: You are right. Any steep takeoff at full power would send everything towards the back, leading to a rapid tail-heavy condition, stall, and crash.
Comment: @WayneWerner Sure but when your cargo is five military armoured vehicles, the effects aren't really comparable to a passenger plane full of people and their luggage.
Answer:
Why is this required to be done?

As far as I know, this is not required by law, it is an operational practice by airlines. According to Wikipedia "It allows a large quantity of cargo to be bundled into a single unit. Since this leads to fewer units to load, it saves ground crews time and effort and helps prevent delayed flights."

Why don't they simply keep the luggage in the luggage compartment?

baggage can be loaded into ULDs while the aircraft they are intended for is still in flight. This reduces turn-around time. Aircraft only earn money when they are in the air, on the ground they bleed money from the airline's shareholders. Airlines try to keep aircraft in the air and avoid having them on the ground as much as possible.

Why is loading the luggage piece-by-piece time consuming

Because luggage is not of uniform size, shape and strength. Therefore it is a labour-intensive process not especially amenable to full mechanisation.
It simply takes longer to load 50 (say) randomly shaped objects than it does to load one object of standardised shape and size.

at the end, in second photo mentioned there, the luggage is being loaded piece-by-piece. What is that?

I don't know, but it seems plausible that some passengers are willing to pay for their luggage to be carefully hand loaded. I.e. first-class. This allows those passengers to pay for an express boarding process and spend less time in the airport.
Comment: `baggage can be loaded into ULDs while the aircraft they are intended for is still in flight.` That. Keeping aircraft on the ground costs money. Loading the cargo in larger containers up front saves time while loading the aircraft.
Comment: It's hard to tell but it looks like the second photo shows a B737 which is not a wide body and therefore does not have accomodation for ULD's in the belly.
Comment: @Mast then why do LCCs not universally use ULDs (or other containerised storage to include 737s here!), given they almost always have shorter turn-arounds than most wide-body aircraft?
Comment: @gsnedders Ask them, or ask a separate question on this SE. I don't know.
Answer: Well there are several advantages of loading the luggage in unit load devices (ULDs) such as:

In ULD, the luggage suffers much less shock than it would, if left alone. Else, the incidence of baggage manhandling would increase several times. We are already losing \$2.58 bn/year  due to this.
ULDs lead to better use of aircraft cargo space. Stacking the luggage one over the other would be a very time consuming and tiring job, and if it is not done, then a lot of cargo space of aircraft would be wasted. ULDs help prevent this.
ULDs are cost effective. Compare the cost of 100s people busy in stacking the luggage, and one conveyor belt doing the job.
ULDs are safer, in the way they prevent unauthorized access to the luggage.

And, in the second picture shown there, the luggage is being loaded into luggage hold. Which has several Pallets/Nets for storing small ammount of luggage. Usually, they are used to store some small cargo belonging to first class passengers.
Comment: I removed the mathjax to avoid unnecessary calls when loading the page.
Comment: I missed the 's' there! By CS, it's less time consuming because machines are doing the work while handling ULDs, and at last I am sorry because I can't provide you with any numbers regarding people needed to fill and load the ULDs.
Answer: Think about the benefits of containerisation.  Ships could take days to unload if they carried many different items like lumber, sacks of corn etc.  Along came containers and now you can unload a ship in hours.  The labour intensive part of loading/stacking is distributed toward the containers themselves, and thus frees up the expensive capital item such as a ship or plane to be turned around more quickly.  It all makes economic sense.  so is it required?  yes, if you wish to stay competitive and in business it is.
Answer: There are some safety and security aspects to containing luggage within containers. When content leaks, goes bad, or even explodes, the container may serve to limit the damage to other luggage within the aircraft, along with the aircraft itself.
Comment: The link is now dead but I'm skeptical about it mitigating explosions: explosions usually become _more_ of a problem when they're confined.
Answer: Also, if the airline is feeding flights to other destinations, baggage can be pre-sorted. For example, a flight into CMB (Colombo, Sri Lanka) is commonly used as a feeder service for onward travel to MLE (Male, Maldives). If all the MLE-destination bags are separated from the CMB-destination bags at the time of loading and are in their own ULDs, those ULDs can be simply moved into the MLE aircraft, saving the time to offload all bags, re-sort and separate the MLE ones, and then reload.


Bitcoin consensus and server of miners

Question: I know consensus is what 51% thinking.My questions is where miners communicated?On what server,what port??Where??The must push own api (copy of blocks) for thinking of consensus.So where BTC miners pushing api,for where blockchain explorer used it,where?
Answer: The Bitcoin Network is a P2P network made up of independently operating nodes from all over the world. Miners will connect to this network in order to maintain a view of the network's state, which is crucial to their participation as a miner.
By connecting to the network, a node (and/or miner) will receive and relay information from its peers, about new transactions and blocks. Nodes communicate using TCP, and the standard port is 8333. For a deeper dive into the specifics of the gossip protocol, see this question.
Comment: Thanx.That's help me,because i dont understand P2P network,for comunicate they must have some server,some http or https address where they can use info(broadcast),and where they can push info to other nodes/miners.
Answer:
The must push own api (copy of blocks) for thinking of consensus

If I understand your question correctly, you are looking for an API specifically for managing consensus.
I believe consensus is a kind of emergent property that arises naturally from the ordinary communication between Bitcoin nodes, the sharing of blocks of data.
It is intentional that consensus arise but so far as I know, there is not a specific separate consensus protocol whose job is only to create consensus.
Consensus means that virtually all Bitcoin nodes have the same data, the same view of which blocks are valid. This arises because they all apply the same rules concerning block validity and they all actively share information about blocks they know of.
There is no API for consensus specifically. The API needed for obtaining new blocks in order to find out receipt of payments etc is also sufficient for a node to compare its own copy of the blockchain with another's (or to compare several other nodes' copies with each other). The node can then apply standard rules about which blocks to save and which to discard.
It probably does require some careful thought to design a data sharing protocol in which the accumulation of data at nodes acts in a convergent rather than divergent fashion. It evidently does not need a separate "consensus" API.

Bitcoin consensus and server of miners


How to prevent alt-f1 from selecting Dash

Question: I am running Ubuntu 12.04. Alt+F1 gets intercepted by Unity (I'm guessing) and highlights the Dash icon. I don't want it to do that, as I want Alt+F1 for other purposes. I have scoured google and tried everything I could find, to no avail. How can I prevent Unity from handling Alt+F1?
Comment: You seem to be giving up at this point, but if you post some screenshots of what CCSM looks like for you, it might help.
Comment: Thanks, but I'm back on gnome classic, and it's working fine for me.
Answer: You'll need the CompizConfig Settings Manager (which you can install via the Software Center).
Once open, click on Ubuntu Unity Plugin (in the Desktop section). Under the Behavior tab, you'll see Key to put keyboard-focus on launcher. Simply change the keybinding there.
Note that in later versions of the Unity plugin, the tabs in that plugin have changed (as the comment below by Carlton mentions). The Key to put keyboard-focus on launcher stting is now under the Launcher tab.
Comment: Thanks AibaraIduas, works perfectly although I would add that the option is now in a tab called "Launcher".You can also use the filter to find the option.
Comment: I don't see "Key to put keyboard-focus on launcher" in that app. In any case, CCSM does not have that plugin enabled.
Comment: Note that there is no checkmark by the Unity Plugin, but it is enabled if you are using Unity 3D (since that's what Unity is, a Compiz plugin). Maybe you are using 2D, though I can't even get CCSM to start in Unity 2D. See here to check: http://askubuntu.com/questions/62001/am-i-using-unity-or-unity-2d
Comment: This works :) and both the question and answer still applies in Ubuntu 16.04. @JackOrenstein: why have you not accepted this answer?
Comment: This is just ridiculous. I'm trying out Unity after many years of using Xfce and I have to say, having to  install a program to change a keyboard shortcut is Windows level BS. It even tells you that it's an advanced tool and you may break your system with it. Why the F do I have to use it then for the simplest task? And why do we need more than one place for keyboard shortcut settings?
Answer: The above answer works for me on 12.04LTS Unity 3D. If it's not working for you I wonder, are you using Unity 2D?  If so you may not be able to change settings with CCSM.
In any case see here for several alternative fixes (the question is for 11.10 but many of these still work in 12.04):
How do I deactivate F1 and F10 keybindings in gnome-terminal?
If CCSM is not working for you, you might try the gconf-editor fix (or alternatively dconf)
Commentary: It's really too bad that this particular keybinding can't be changed simply through the system settings interface, as most others can.  I haven't heard that this has been changed in 12.10 but I hope it is in the future.  Far too many programs use Alt-keybindings for the OS to make it so difficult to change.  (And I'm pretty sure Emacs mapped that keyboard real estate first, Ubuntu.)
Comment: Hmm, how do I tell if I'm using 2d or 3d? I tried gconf-editor and disabled every use of Alt-F1 I could find. Still no luck. (And I'm exiting X, logging out, logging back in, and starting X each time I tweak something.) I have to say that I'm really hating Unity. E.g., adding an item to the launch bar required a trip to google.
Comment: Looks like Aibara Iduas commented to provide the link for checking Unity version.  But if disabling through gconf-editor didn't work either...hoo, good luck man.  Though...just to be sure, are you sure it's the Dash that's being opened?  Tapping Alt (without function keys) also opens the HUD in unity.  If I'm on the Desktop this does in fact bring up a highlighted Dash icon.  If that's the case it's Alt alone that's causing the problem, not Alt-F1.  (Same methods for changing the keyboard mapping apply.)
Comment: I'm not sure if it's 2d or 3d. I tried disabling alt. I tried everything in previous comments. I've had it -- I'm back on Gnome Classic, and much happier. Much easier to customize the things I care about, and things just work. Thanks to everyone who helped out with suggestions.


Problems with Blockchain API

Question: Im having problems because when a user pay to a forwarding address, the forward address receives bitcoins instantly, but takes nearly 1 hour to send those bitcoins to the destination address, the real one, and it only calls the API when it transfers to the real one. How can a user deposit the btc instantly? or faster? Thank you!
Comment: Welcome to the Bitcoin Stack Exchange, Christian. Check out the [tour](http://bitcoin.stackexchange.com/tour) and the [help center](http://bitcoin.stackexchange.com/help) if you haven't already. I think your question suffers from a lack of detail. Start from the beginning, what are you trying to do? What API calls are you using? A good question will attract good answers!
Comment: What kind of answer do you want to see? OK, do not use this API and use something else. Seems to me that you should have our own engine and do not rely on third-party services. Wanna hire me for this job? :)
Comment: I would like a solution thats the kind of answer I would like to see.
Comment: I have a stand-alone program which transfers all deposits to a bunch of addresses to one another address immediately. But I am not sure that this solution is acceptable for you. This is just a C++ program for windows, not a web-service. My email is in profile.
Answer: Blockchain.info's receive API has been all wonky for the past month or two. The forwarding used to be almost instant, but lately it has been taking up to 24 hours for the payment to be forwarded.
Remember that THEY pay the transaction/mining fee for you, so they pay as little as possible which can cause a delay in transactions.
In my opinion you should try another forwarding service that is not free. I suggest you try Blockcypher's payment forwarding service. It's very similar to Blockchain's however the mining/transaction fee will be taken from the funds received and you will need to register and create a token.

Problems with Blockchain API


Chromatic vs Non-diatonic vs Accidental

Question: I was wondering if all three of these terms: chromatic, non-diatonic, accidental, all mean the same thing?
Comment: "Chromatic scale" is a legitimate term. "Accidental scale" isn't.
Comment: And there can be "chromatic music" and "non-diatonic music," but we don't have "accidental music" unless we're talking about wind chimes or dogs howling in the neighborhood because an ambulance goes by.
Answer: The three terms may refer to the same note in a piece but they do not really mean the same thing.
Chromatic refers to out-of-scale half-step movement. For example F to F# in the key of C or to notes that are not within that scale. Chromatic may refer to several notes in a row, C-C#-D-D#-E for example.
Non-diatonic generally refers to notes not in a given major key. The term isn't quite as useful in a minor key piece as the 6th and 7th scale steps are mutable and both versions are often referred to as diatonic (leaving only two notes as non-diatonic in even-temperament).
Accidental refers to the flat or sharp sign attached to a note. A note with such a sign may be called an accidental for short. However, such a note may be diatonic as in the key of D-major, one might have an F-natural followed by an F# (no natural sign on my character set.) Both notes have an accidental applied.
Comment: Chromatic doesn't have to be a half-step movement.  An F# in the key of C is chromatic even if the note preceding it is an A and the note following it is a D.  Such voice leading is not a chromatic *scale,* but it is chromatic.
Comment: This seems basically good to me, but in addition to @phoog's quibble,  I have another, which is that I believe "diatonic" can be used to refer to a scale built on the diatonic pattern of half- and whole-steps, regardless of whether there is a major key. For example, I think a melody that goes BCDFGEAFEDCABCD is considered diatonic, regardless of whether the tonality is C major, A minor, some church mode, or no key center at all.
Comment: I've tried to give also an answer. But the question and terms are confusing me more and more: are the signs following the clef accidentals too? Is the sign for the natural note, that resigns an accidental also an accidental?  Is a natural g in E a chromatic note or is the g# chromatic? Or both? Or any? What about the blue notes? They are altered down, belong to a definf scale, are they chromatic, or accidentals or non-diatonic? How about enharmonic changes? An f as enharmonic change of e# is it what? So I had to delete my answer not confusing others? Stiil some clearing needed to remove?
Comment: a bit confused by the last paragraph. I thought that accidentals were non-diatonic by definition. If I'm in the key of D-major you'd flatten the F# to get to F, but flattening it (ie using an accidental) would now make it non-diatonic.
Comment: @foreyez: I think the last paragraph is right. For example, say you have a piece that starts in G, but later modulates to D The person notating the music can choose whether to notate the later section using accidentals or introduce an explicit change in the key signature. If they notate it using accidentals, then that section is full of C# notes that are accidentals as a matter of notation, but are diatonic in the key of D.
Comment: @BenCrowell thanks for that comment , a light bulb went off in my head.
Answer: Diatonic - belonging to a specific key - as in those notes played in a scale in that key.
Non-diatonic - any other notes which are not diatonic! As in they are not part of the set of notes which constitute a specific key.
Accidental - a sign which changes a note from the original, but retains the same letter name, E.g. B♭ appearing in the key C. It's non-diatonic, so the B gets changed with an accidental into B♭; F ♯ appearing in the key C. It's non-diatonic, so the F gets changed into F♯; Bnat. needs a natural sign in the key F, as diatonically, there's B♭. On certain occasions, ♭♭ and x are used to denote doule flat and double sharp. They also are know as accidentals.
Chromatic - any note which is non-diatonic, and will need an accidental sign to qualify it in a key.
Note (!) the signs at the beginning of a piece which we call the key signature are not accidentals - they're there on purpose! Called - the key signature.
Answer:
Accidentals are signs as flats (b) and sharps (#) usued for alteration of the tone pitch, also the sign for a natural tone. The altered notes may also be called accidentals.
Non-diatonic are the tones that are outside of a given scheme (scale) of whole tone - and half tone steps. Sometimes they can be identified by the accidentals.
The chromatic scale consists of 12 half tone steps. Notes that don't belong to a defined scale are chromatic.
Altered tones, notes with accidentals, can be  chromatic tones or non-diatonic or both. The term "chromatic" describes the new color given by an alteration.
The more I know ...  the more I know that I know nothing!
Comment: but the moment I see an accidental, I can assume the resulting pitch is non-diatonic?

Chromatic vs Non-diatonic vs Accidental


Example of film/tv scene where visual triggers audio only flashback?

Question: I am planning a scene where the lead character sees a mother and child, it triggers a memory from his childhood. Instead of flashing back showing him as a child with his mum, we thought just have the audio over the top would work with an echo or other effect etc.  Does anyone know of any examples of this in other movies, as our DOP is
struggling to visualise how the final would work? I am sure I have seen it in other movies.
Answer: I can't think of specific examples, but what I can "see and hear in my mind" is:

a single shot of the character who's having the flashback
the actor's face is reacting to the audio in the flashback
the camera slowly zooms or trucks in on the actor's face
sounds in the present-time scene have become quieter and/or muffled
the audio flashback may have an echo or reverb added to it
there may be visual flashbacks subtly transposed over the present-time shot
Answer: I guess that this all depends on the nature of the flashback.
If it's something sort of happy or sinister that we're going to dwell on (as a viewer), then (as Brett said) slow is the way to go (really play on those reactions - dolly zoom if you want to play the Spielberg card).
If you're going for maximum impact and a shocking/scary reaction from the character, I'd play this out quicker - smash cut from the character's face to a CU/XCU of the parent & child then back again (throw some Dutch in there for memes), perhaps some flashes of light and the character visibly moves their head/flinches when they hear the sound, as though it's disorienting. Make the memory noises nice and loud or cutting - again, as Brett said, you'll need to keep them higher in the mix, probably by lowering other noises or having them combine.
I think Sherlock does stuff like this when he's in the throes of cogitation, perhaps some scenes from Hannibal... I'll try and think of some more examples.
Answer: @Jamie & @Brett have very insightful answers. From the perspective of script writing and production notes, I have nothing to add.
It seems to me that your question is more about "what it would look like to the audience" instead of on a script.

Have a look at this youtube video.
Interview: Catatonic Schizophrenic

this is a WA shot up to about 2:07. Notice how his body is very still, but his eyes move during the pauses.
After 2:07, it's a CU of his head. Notice his face & eyes during his pauses before answering a question.

What I see:
Your character, during the "auditory flash back" would be, effectively catatonic. As (s)he remembers the past experiences, this is the kind of behavior the body would naturally do. Eyes darting about & focused on infinity, slight head movements & facial expressions. It is even possible that (s)he would mimic the posture of the Mother and then mimic the child. Perhaps even mouthing the words.
As you can see, though, it could be a bit boring for the audience if the flashback lasted for more than several seconds, so something needs to happen visually.
$0.02


Subdivide Surface Modifier messes up concave shape

Question: I encountered a problem while modelling a toothed shape. When I applied the Subdivision Surface Modifier and added the supporting geometry so it doesn't look all that distorted, two additional pieces of surface stretched over the spaces between the teeth.
It seems there is a connection between the left and right edge and the middle vertex which I can't select and edit.
Comment: this is due to the fact that your top face is a concave polygon. Subsurf does not differentiate between concave and convex polys so when the new verts get smoothed you end up with this kind of errors. To fix this you will have to either triangulate your concave poly (easy fix, not recommended), or retopologize it manually (it takes some time but it is worth it). Cheers.
Comment: When using the subsurf modifier try to avoid ngons (polygons with more than 4 vertices)
Answer: I'd try to recreate your mesh, as it's easier to do so as fix your mesh.
Create a rectangular plane and use loop subdivide, using ctrl-R + Mousewheel.

With this basic mesh, consisting only of quads, and the loop subdivide technique, it should be easy for you to use the subsurf modifier.
Comment: It might not be as easy as expected as spikes made of 1 vertex will be smoothed and become a bulge. When subsurf is present supporting geometry should be as well, so those spikes should be beveled (Ctrl+Shift+B) and then the supporting loop to appear all around the spikes (like inset does), then once smoothed the object will preserve the form.
Comment: Yes exactly, although I guess it's only ctrl+B, but nevermind. Another possibility would be to set loop subdivides close to the verticies that shouldn't be smoothed, both should work


Adobe scripting compatibility for different products

Question: I am trying to understand scripting for adobe products using extendscript and I have a doubt whether I can re-use a script between different adobe products like ai, ps, pp and ae? Will there be some kind of granular level modifications between each of these product's apis?
Comment: I'm not sure if there is a proper answer for this question. On the surface level, yea, you can write a script that works in all of those applications, but in the end it depends a lot on what the script does. Every application has their own specific properties and methods that the other apps don't have. You can do a conditional check which app the script is being run in and use different methods based on that, but like I said... it super depends on what the script does. You'll find out at some point if you start writing the script.
Comment: @Joonas At this moment, I am trying to create a panel in which the user can fill out certain details and select a file. Once he hits submit, I want to upload the file along with the details to my server using my API. Also, Is scripting for CS different from CC?
Comment: Scripted panels work really badly in illustrator, hardly worth doing at all. Not sure about socket programming.
Comment: I haven't done file uploads from a CEP extension myself and I don't know if there are any specific quirks there to watch out, but it sounds general enough that it could work. Scripting in general (Extendscript) is pretty much the same in CS and CC, but extensions may have a few hurdles. I don't really know though.
Answer: They are like if they were separate programs from different companies (because that is what the separate divisions kindof are). They have some similarities but not that much (mainly because they use a similar unerlying module). AE is very different from PS and AI that are closer. But AI has the least mature scripting interface, PS has a tool to turn unscripted action to mystical calls. AE and InDesign have much more mature scripting interfaces. After effects is the most different one scripting wise.


What happens after one's credit card transaction was declined after he has received the service?

Question: Assume someone received some service (for example, had his hair cut) and had made the payment using his credit card. What if this transaction was declined later? Does he still owe the money that he was supposed to pay? From the shop's point of view, how can the shop charge this customer then, after he has left?
Comment: Where is this taking place?  In the US, it would be really unusual for the transaction to be processed after the customer had departed.  The authorization would normally be done online.  If you're somewhere else, procedures and laws may be different.  It seems highly unlikely that any country would say that the customer didn't legally owe the debt in that case though the shop's practical ability to collect might be limited.
Comment: The service receiver still owes the merchant money. Bear in mind that, this is no different than getting food served when you dine inside a restaurant.  The merchant has the rights to negotiate a term of payment or calling the police.
Answer: If the service was provided, you must pay for it. A declined credit card is like a bounced check in this regard: the service provider is still owed payment.
From the shop's point of view, they are probably out of luck. The amount is likely too small to bother to pursue in small claims court, and their only recourse is to dispute the chargeback with the credit card company.
I'm not sure if you represent the shop or the customer, but the right thing to do (regardless of jurisdiction and law) is to pay for the haircut! If you're the shop owner, I'd recommend figuring out how the charge was declined after the fact and look for ways to avoid similar situations in the future. If you're the customer, please realize that you need to pay and make it right. Just because you can get away with something doesn't mean you should.
Comment: In fact, the merchant has the rights to call the police if the customer refuses to pay.
Comment: Thank you for your answer! I represent neither; I am just curious about this scenario.
Answer: The purpose of running the card through the reader is to get authorization from the network. If the transaction is later denied, then that is a dispute that the business owner has to make with the network.
This has to be a very rare situation, or the business owner would never accept a credit card/debit card. The fee that is charged by the network is to cover the risk that the network has in addition to their costs.
A few years ago in the US as we were changing to using cards with chips, the carrot that the networks used was how the risk of a fraudulent transaction would be assigned if the store didn't install the new readers. No new reader meant that if there was some kinds of fraud, then the store would cover the loss. But if they installed the new readers, then the network covered the risk.
For some businesses they can contact the individual because they have more information about the customer, but in some cases the transaction is essentially anonymous. In those cases the only info they have is related to the info on the card that was ultimately denied.
Ultimately the customer is responsible, so the denied transaction doesn't absolve them of the debt.
Comment: "if they installed the new readers, then the network covered the risk." Basically the issuer of the card ( the bank/Credit union) or the MasterCard, Visa or American Express should be paying. Banks want it both ways, if a charge is authorized by running through chip reader, after that it should not be an issue with customer ( unless customer has called the bank to stop payment)


How do I copy old emails into a new IMAP account

Question: I am a novice. How can I copy my old emails stored in Outlook 2010 via a POP account onto a new IMAP account that I have setup to replace the old POP account so that I can see all my old emails through a single IMAP account
Answer: There might be easier ways depending on you control over the mail servers. But have you tried configuring the new account in outlook and copying messages from the old one to the new one. Haven't used outlook really but if you have troubles with it, you could try thunderbird and copy messages in bulks if single operation for all messages fails.
Answer: You can export all your local E-mails to an external PST file. Then switch your configuration to IMAP and import all exported E-Mails into the IMAP folder structure.
Answer: You should be able to just create a new IMAP account (with a new PST file) then drag your emails from your old PST file into a folder in the IMAP PST. It'll sync them automatically.


Confidence interval for expected prediction error from cross-validation

Question: I am using a support vector machine for binary classification on a sample of size 150 (75 of each class). I am using 5-fold stratified cross-validation to estimate the expected prediction error, i.e. the expected generalization error for a random (stratified) training set of size 120. I am using 0-1 loss for the prediction error. My estimate for the expected prediction error from the cross-validation is unbiased, however since the training and test sets are not independent I don't see how to calculate confidence intervals (standard errors). However I need confidence intervals in order to show that my good result is not just a peculiarity of my dataset. Can anyone give a good method to estimate confidence intervals?
Answer:
My estimate for the expected prediction error from the cross-validation is unbiased, however since the training and test sets are not independent

If training and test set are not independent, how can you be sure the estimate is not biased?
Assuming with "not independent" you refer to the fact that between each pair of surrogate models of the cross validation $\frac{n (k - 2)}{k}$ of the training cases are shared:

I need confidence intervals in order to show that my good result is not just a peculiarity of my dataset

If I understand you correctly, this is not possible if you want to generalize to other data sets of the same type and your modeling alogrithm. See Bengio, Y. and Grandvalet, Y.: No Unbiased Estimator of the Variance of K-Fold Cross-Validation Journal of Machine Learning Research, 2004, 5, 1089-1105
In contrast, if you want to generalize to prediction of unknown cases by the particular model you trained on that particular data set (i.e. the "peculiarities" of the training data should be included, just not of those of the test cases), binomial confidence intervals with $n$ = total number of cases account for the uncertainty due to testing only $n$ cases.
This assumes your model (and surrogate models) are stable, otherwise you'd need to account for the instability variance.

Update: where does that difference come from / what variance is missing wrt. the Bengio question?
The difference is that for estimating the performance of the training algorithm you need to know how much the estimated model or its predictions vary wrt. to the actual training set (model stability). In order to decompose these sources of variance, you'd need to measure performance for a number of disjunct training sets. Unfortunately, you typically don't have enough cases to look at the variance in predictions of disjunct training sets.
Iterated CV allows you to have a glimpse at this by measuring the stability while not with respect to a completely new training set, but at least with respect to exchanging a few cases.
Comment: Thank you for you answer.With unbiased, I mean that the expectation of the cross-validation over all possible datasets of size 150 is the expected prediction error for a training set of size 120. Of course we can't converge to that value as long as we have only one dataset. The article you are citing says so as well: "While it is known that cross-validation provides an unbiased estimate of EPE, it is also known that its variance may be very large (Breiman, 1996)."
Comment: As there is no unbiased estimator, does anyone know an estimator with small bias?


Decrypting ciphertext produced by the Trivium stream cipher

Question: Given a message that is encrypted using a Trivium and the key that was used to encrypt it, how does the receiver decrypt the message?
Comment: That's two rather different questions, please split the question in two separate questions (I can easily answer one of them, the other not so easy).
Comment: Edited out "I am also wondering why the three registers in a Trivium were chosen to be of different lengths."...
Answer: Trivium is a synchronous stream cipher. For synchronous stream ciphers the key stream is independent of the plaintext and ciphertext.
The key stream (which is not the key itself, but the output of the cipher construction) is then combined in a reversible way with the plaintext to for the ciphertext (commonly byte-by-byte). The reverse operation with the same key stream and the ciphertext brings back the plaintext.
Usually XOR is used, which allows you to use the exact same construction for both encryption and decryption (as $PT \oplus KS = CT$ and therefore $CT \oplus KS = PT$).


Salesforce1 Mobile Navigation settings Custom object tab not appearing

Question: I am planing to add one of our custom object tab under APP section in salesforce1 navigation menu. To do this I need to place custom object tab below smart search in Mobile Navigation settings. But my custom object tab is not listed under available section inside Mobile Navigation settings. The tab is already created and added to my available tab in  full sales force. Anything missing or something else has to be done ? Or is it a restriction the standard and custom objects will appear only inside the smart search Items.
Comment: Permission issue for object or tab on the logged in user profile ?
Comment: No the user is having enough permissions
Answer: The smart search items will by default show all objects (both standard and custom) to which a user has access too.
The user himself can control in which order he sees the objects by pinning objects after doing a search in regular Salesforce.
I have explained about this pinning mechanism in more detail here:
Change order of tabs in Salesforce1
Also mentioned in my answer there, if the way the smart search items with the pinning isn't acceptable for your business you can have more control over your menu and which objects appear or not by working with flexipages.
I have written an article about that which you can find here:
Flexipages: The Hidden Gem in Saleforce 1


Does more acidity = better electrolyte?

Question: I am trying to figure out what makes an electrolyte better than another. I originally thought it was acidity, but a potato produces more voltage than a lemon. When I tried this same thing with acetic and muriatic acids, I found that acetic acid produced a constant voltage of a little under 1, while the muriatic (hydrochloric) acid started at about .60v and rapidly dropped into a negative voltage. So if acidity is not an indicator of a good electrolyte, what is?
Comment: The key terminology you want to look up is [van't Hoff Factor](https://en.wikipedia.org/wiki/Van_%27t_Hoff_factor).
Answer: Essentially, 'how good of an electrolyte' something is depends on how many particles the substance dissociates into. Let us discuss acidity. Now, from experimental evidence, it may seem that 'stronger' acids and mixtures, such as HCl, $\ce{H2SO4}$, Muriatic, are all good electrolytes. These are not because of their relative acidities. You will notice that in my last sentence, I put 'stronger' in quotes. This is because when talking about acids, 'stronger' has a different meaning than the one you are used to. A strong acid is one that dissociates virtually 100%. In other words, when you put a strong acid in water, all of it turns into ions, and you have none of the original acid left over. Similarly, a weak acid is one that does not completely dissociate into ions. By the definition of an electrolyte, stronger acids are better electrolytes (more ions in solution). This leads to our next point, ions in solution. As mentioned by Zhe above, the 'Van't Hoff Factor' is important. Essentially, it is just a measure of how many particles a substance dissociates into, for example NaCl has a VHF of 2, whereas $\ce{CaCl2}$ has a VHF of 3. The higher a substances VHF, the better of an electrolyte it is, the reasoning being that with an increase in number, there is an increase in dissolved particles, and therefore an increase in the state of being an electrolyte. Now, going back to acids for a moment, you may be wondering which acids are strong. There are 6, and they are HCl, HBr, HI, $\ce{HClO4},\ \ce{H2SO4},\ \ce{HNO3}$. Weak acids are everything else. These strong acids will have the best electrolytic results if you use them as such, much better than lemon juice (citric acid) or vinegar (acetic acid). In your example, you used muriatic acid (HCl) as one of your ion-producers, which explains the rapid voltage change, occurring from the dissociation of a strong acid.
$$\text{In essence, the answer to your question is:}$$ $${\text{How many particles a substance dissociates into determines how good of an electrolyte it is.}}$$
Comment: Which better electrolyte : $\ce{CaCl2}$ or $\ce{HCl}$ ?

Does more acidity = better electrolyte?


Underwater technology?

Question: How would aquatic aliens create technology? ( Think late 90's style, and by that, I mean: Phones, metallurgy, electricity, public transportation (think trains), books (and ink that would not just dissolve in water), oven and stoves, (maybe even a tv like thing?), even the building themselves). Suppose that they have no access to land whats so ever, and that the water that they live in is not really water, but a liquid that can with no problem at all, have sufficient amount of oxygen to sustain hot-blooded mammalian creatures through reasonable sized gills, and the planet is mainly made of shallow (around under 150 meters deep) oceans, and very little of it is a desert.
Comment: This question is too broad. I'd focus more on the most basic, underlying and critical issue: how does an aquatic species develop _any_ kind of technology beyond the stoneage, given the almost unsurpassable hurdles that need to be cleared to discover fire, which is a prerequisite for metalwork and all the rest?
Comment: Can mammals have gills?  I think a diaphragm and a four-chambered heart are a common characteristic of all mammals, whether terrestrial or watery
Comment: Oh... Well... I think you are rigth... My bad...
Comment: Agree on the duplicate. The answer in that thread is spectacularly comprehensive.
Answer: Your aquatic species could develop any level of technology we Telurians (People of Earth) have developed using the same processes we've developed but they might have different motivations.
How they interact with their world will determine the form of their technologies.  Do they have two arms or twenty?  Do they have fingers or suckers?

Assuming they have a way to manipulate the things in their undersea world, they have to have culture, which gives rise to language, which gives rise to what we consider thought.  Thought gives rise to questions, which engender answers and disagreements.  All this, obviously, leads to war.
War means better weapons and defenses than the other clams or guys. This means they learn how to construct defensible enclosures out of seaweed, hermit crabs and coral reefs.  Which means they figured out how to make tools out of things that can cut seaweed, hermit crabs and so on.
Once they've learned to fight and survive and have time to start questioning why coral is like coral, they can begin to explore the concepts we know as chemistry, physics, and mathematics.  Once intelligence and sapient creatures start on that path, there is no turning back since more and more of the world starts making sense, at least until some nabob invents economics and messes everything up for a while.  But, that is a different discussion.
Once minds start trying to figure out the world around them using science, they then can figure out to make things they need or want to make their lives longer, safer, healthier, etc.  Given their world, they may find ways to create biological solutions were we Telurians depend on physics-based solutions.  But, once they have a need, they can find a solution whether how to make electricity or how to melt and purify silicon.
The long and the short of it, pretty soon you have Facebook and StackExchange and sneakers.
Albeit, it's very different from what we would know since they have a very different world than we do, and have different motivations as a result of their environment.
Comment: Oh... This is a nice answer,  I like how you compare humans and those alien things...
Answer: Biology first
Human technology began with fire. Once we learned to make fire, we learned how to melt and shape metal. Chemistry, too, stems mainly from fire; heating and burning things to figure out what they were made of.
An aquatic species is going to have a hard time going this route, but they have an advantage that land-dwellers lack - the richness of undersea life. Aquatic organisms are far less restricted morphologically than terrestrial ones, and many of them have exotic chemistry and hard shells, both of which could prove potentially useful to a budding sapient species.
Instead of forging metal weapons, an aquatic species may grow them by domesticating creatures like snails and clams, and breeding them to produce shells in the shapes that are needed, ranging from sharp speartips and knives to shovels, bowls, and armor.
There is a species of sea snail that actually incorporates iron into its shell (it lives near deep-sea vents and eats iron sulfide, chemically separating the iron and using it for protection).  If a similar species could be domesticated and bred, this could produce more advanced tools.
As the species grows more advanced, it could begin exploring the various different poisons and other chemicals produced by species in its environment, and by studying how they interact it could develop theories of chemistry without the use of fire.
This could lead to a more advanced understanding of physics and ultimately produce technology not unlike our own, although it is likely that they would be far more inclined to use biotech rather than metallurgy, since they'd be building off of thousands of years of experience working with living things.

Underwater technology?


Chromium enable seccomp-BPF sandbox on Debian 7

Question: I discovered that my version of Chromium (Version 29.0.1547.57 Debian 7.1 (217859)) does not have all the sandbox features turned on by default. Navigating to chrome://sandbox/ gives results:
Sandbox Status
  SUID Sandbox  Yes
  PID name spaces   Yes
  Network namespaces    Yes
  Seccomp-BPF sandbox   No
You are not adequately sandboxed!

Can I turn on the Seccomp-BPF sandbox? My OS stats are:
$ uname -a
Linux compname 3.2.0-4-amd64 #1 SMP Debian 3.2.46-1+deb7u1 x86_64 GNU/Linux

And since I have uninstalled my desktop manager, I normally start Chromium from the commandline like so:
nohup chromium >> /tmp/chromium.nohupout &
However, I have also tried starting Chromium with the --enable-seccomp-sandbox flag, and the sandbox still remains off. When I do this, I get the warning message in stderr:
ATTENTION: default value of option force_s3tc_enable overridden by environment.

Solutions which do not involve me recompiling chromium from source are preferable.
Answer: Sandbox of that type aren't supported on kernel 3.4 or lower; you can use the debian backport to obtain a more recent kernel but keep in mind it'll be less stable.


Byte[] to InputStream or OutputStream

Question: I have a blob column in my database table, for which I have to use byte[] in my Java program as a mapping and to use this data I have to convert it to InputStream or OutputStream. But I don't know what happens internally when I do so. Can anyone briefly explain me what's happening when I do this conversion?
Comment: Shouldn't the title be "array of bytes ..." or "byte array..." or "byte[]..." instaed of "byte of array..."?
Comment: See the reverse here: http://stackoverflow.com/questions/1264709/convert-inputstream-to-byte-in-java
Answer: You create and use byte array I/O streams as follows:
byte[] source = ...;
ByteArrayInputStream bis = new ByteArrayInputStream(source);
// read bytes from bis ...

ByteArrayOutputStream bos = new ByteArrayOutputStream();
// write bytes to bos ...
byte[] sink = bos.toByteArray();

Assuming that you are using a JDBC driver that implements the standard JDBC Blob interface (not all do), you can also connect a InputStream or OutputStream to a blob using the getBinaryStream and setBinaryStream methods1, and you can also get and set the bytes directly.
(In general, you should take appropriate steps to handle any exceptions, and close streams.  However, closing bis and bos in the example above is unnecessary, since they aren't associated with any external resources; e.g. file descriptors, sockets, database connections.)
1 - The setBinaryStream method is really a getter.  Go figure.
Answer: I'm assuming you mean that 'use' means read, but what i'll explain for the read case can be basically reversed for the write case.
so you end up with a byte[]. this could represent any kind of data which may need special types of conversions (character, encrypted, etc). let's pretend you want to write this data as is to a file.
firstly you could create a ByteArrayInputStream which is basically a mechanism to supply the bytes to something in sequence.
then you could create a FileOutputStream for the file you want to create. there are many types of InputStreams and OutputStreams for different data sources and destinations.
lastly you would write the InputStream to the OutputStream. in this case, the array of bytes would be sent in sequence to the FileOutputStream for writing. For this i recommend using IOUtils
byte[] bytes = ...;//
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
FileOutputStream out = new FileOutputStream(new File(...));
IOUtils.copy(in, out);
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);

and in reverse
FileInputStream in = new FileInputStream(new File(...));
ByteArrayOutputStream out = new ByteArrayOutputStream();
IOUtils.copy(in, out);
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);
byte[] bytes = out.toByteArray();

if you use the above code snippets you'll need to handle exceptions and i recommend you do the 'closes' in a finally block.
Comment: didnt you mean  - ByteArrayOutputStream out = new ByteArrayOutputStream();  instead ByteArrayOutputStream out = new ByteArrayInputStream();
Comment: CloseQuietly should probably be in a finally clause.
Answer: we can convert byte[] array into input stream by using ByteArrayInputStream
String str = "Welcome to awesome Java World";
    byte[] content = str.getBytes();
    int size = content.length;
    InputStream is = null;
    byte[] b = new byte[size];
    is = new ByteArrayInputStream(content);

For full example please check here http://www.onlinecodegeek.com/2015/09/how-to-convert-byte-into-inputstream.html
Answer: There is no conversion between InputStream/OutputStream and the bytes they are working with. They are made for binary data, and just read (or write) the bytes one by one as is.
A conversion needs to happen when you want to go from byte to char. Then you need to convert using a character set. This happens when you make String or Reader from bytes, which are made for character data.
Answer: output = new ByteArrayOutputStream();
...
input = new ByteArrayInputStream( output.toByteArray() )

Answer: I do realize that my answer is way late for this question but I think the community would like a newer approach to this issue.
Comment: Circular buffers do not solve the OP's problem.  In the Question as written, the OP needs the *entire* content in a single byte array.
Answer: byte[] data = dbEntity.getBlobData();
response.getOutputStream().write();

I think this is better since you already have an existing OutputStream in the response object.
no need to create a new OutputStream.
Answer: String info = "somedata";
OutputStream os=new FileOutputStream("mydata.bin");
        byte [] datas= info.getBytes();
        os.write(datas);

InputStream is=new FileInputStream("mydata.bin");

        datas=new byte[1000];
        int counts = is.read(datas); //reads all data from bin to datas then returns size

        info = new String(datas,0,counts); //
        is.close();;

        System.out.println("From Binary File: " + info);

Byte[] to InputStream or OutputStream


Measuring Vibration

Question: I want to measure the vibration in an environment so that I can isolate some equipment. What is the standard way of measuring this? Basically, I want to mitigate the effects of a nearby train. More important than the loud horn, I need to isolate the equipment from vibrations in the ground. I am looking at some products from newport, but they show resonance around 6Hz. Would vibrations produced by the train be incompatible with these? How can I measure such vibrations? I have some audio microphones and software that shows a spectral distribution, but I don't want to know about the vibrations transmitted through the air as much as I want to understand how much noise is traveling through the concrete floor. I tagged this experimental physics, because it is likely that an experimentalist would have a good answer.
Comment: You could use a seismometer for ground vibrations: https://en.wikipedia.org/wiki/Seismometer#Teleseismometers.
Comment: The resonance peak is an inevitable consequence of the way these passive isolators work. The more important fact is that *below* the resonance frequency, they don't do anything - the transmissibility plot is a flat line at $1.0$. The resonance frequency will depend to some extent on the load that is being supported. As the answer says, first *decide what frequencies need to be attenuated* and *how much attenuation you need.* This http://www.minusk.com/content/technology/vc_curves_minus_k_vibration_isolation.html might be useful (and explore the rest of that website).
Answer: There is no need to measure the vibration. The unwanted vibrations must be having some undesirable but detectable effect on the output of your experiment. The effect you are getting compared with what you expect from ideal conditions is a measure of the noise. The improvement in your output signal will tell you what effect anti-vibration materials or techniques is making.
Ground vibrations from trains peak between 4 and 50 Hz. Your anti-vibration strategy should focus on eliminating these frequencies. If your output signal is far from this range, it is unlikely to be affected by railway noise.
A useful exercise is to look at the frequency spectrum of your output signal, using a spectrum analyzer. Some digital oscilloscopes perform this function. The sidebands on the strongest peaks in the signal spectrum will suggest what the frequencies of the major noise sources are. Narrowing of the peaks in the frequency spectrum also shows improvement in your signal.

Measuring Vibration


Deny access to one database, allow all the rest

Question: How can I deny access to specific databases from a login?  I know that I can walk through and make the login a db_owner on all the ones I want the login to have access to, but how do I do the opposite?  I want the login to have access to everything but the ones that I specify
Answer: I would highly suggest you not assign a login to db_owner just "to have access to" a database unless you want them to have "admin" privileges in that database.
You also have to consider what permissions the login has at the instance level first. Assigning a user to db_denyXXX will have no affect if the login is sysadmin or securityadmin privileges.
If we are talking about a "regular" login on the instance you prevent them from accessing the database by not mapping that login to a user in the database. If no database user exist in the database for the login then they cannot connect to it, as long as they do not have higher privileges at the instance level.
Answer: You can explicitly map the user to db_denydatareader and db_denydatawriter for that database, either through SSMS or the relevant tsql statements. For paranoia's sake you could also loop through every object and deny that user select/update/exec rights too.
Comment: I think you meant db_denydatawriter and db_denydatareader :-)
Comment: @Kin: Good catch! Fixed.
Answer: You can also use LOGON TRIGGER to achieve this if you dont want to explicitly map user to    db_denydatawriter and db_denydatareader.
This way you just have to change (update or delete) users in a table that is used for logon trigger.
Refer to my script at : https://dba.stackexchange.com/a/37382/8783
Note: Existing sessions won't have to go through the trigger. But you can over come that by first killing all the sessions and then enabling the trigger so that all the new incoming connections have to go through the trigger.


How do I stop my note 4 from activating the screen when it is done charging?

Question: When I charge it at night and its finished the screen will stay on all night unless I plug it out. How do I stop this from happening.
Answer: Do you have the Developer Options settings enabled on your phone? If you do, go to Settings >> Developer Options >> Stay Awake. If that option is checked, then your phone will never sleep while charging. Uncheck it.
Also, in Settings >> Display >> Daydream >> When to Activate (at bottom),do  you have Daydream set to activate while charging? It's possible Daydream is triggering.
Answer: Change the screen timeout option, or the 'Never sleep on charging' option
Comment: How does someone do this? Needs more detail.


LaTeX for netbook OSes

Question: I'm considering buying a netbook for the express purpose of writing maths notes/articles (so as to not heft my Macbook around), hence (La)TeX is a must. The most obvious choice is to work with Linux, but failing that I was wondering if there is a LaTeX distribution for Chrome. And as I'm unfamiliar with the version/s of windows that appear on netbooks, would the usual distributions (MikTeX, say) work for them?
Comment: @Caramdir Chrome is (apparently) also an [operating system](http://en.wikipedia.org/wiki/Google_Chrome_OS)
Comment: Not too realistic a solution, but in the worst case a simple text editor should suffice: you can always build the documents on your Macbook when you get home.
Comment: Why this insistence on "netbook-suitable" distribution of linux? Netbooks are perfectly capable running "normal" distributions of linux, even ones compiled from source. (Disclaimer, I run Gentoo on my netbook, and texlive works just fine.)
Comment: Does http://tex.stackexchange.com/questions/3396/what-useful-web-services-are-out-there answer your question?
Comment: I want to be able to work offline, so google docs is not the solution I'm looking for!
Comment: What exactly do you mean by distribution for Chrome. Google Chrome is a browser, not an operating system, so it is generally not used for doing stuff offline.
Comment: In my experience writing on netbook is much slower than on a normal computer: the keyboard is smaller, the screen is slower, the processor is weaker. So, unless you can postpone writing until you are at the office, it is probably better to avoid doing it on a netbook.
Comment: Acer Aspire One (single core Atom prosessor) with Windows XP and MikTeX compiles 10 seconds. It is awful if you like compiling after every change. LyX might work.
Comment: @Caramdir - Will is right, Chrome OS is forthcoming, but I should have done my homework as to how it will work! Apparently it is just a lite OS designed for working almost exclusively online.
Comment: @Charles - A mac mini on the train?? I'm thinking either cafe or train use, and I've had a mini for 5 years, and this never occurred to me. :P
Comment: @David As far as I know, no hardware with Chrome OS is announced yet. And according to Wikipedia, "Chrome OS will not be available as a download to run and install."
Answer: Google Chrome OS is just a basic basic stuff that is needed to start the web browser, not much more.
My guess is to use something like the netbook edition of Ubuntu, that one has a gui that may fits those smaller screen quite well.
And the goodie is then that you can apt-get all the normal LaTeX packages that is present in the normal Ubuntu dist.
Comment: One thing about using apt is that the packages tend to come in chunks of several hundred megabytes.  You end up with a lot of stuff you don't use and netbook drives tend to be on the small side.  Installing TeX live and managing things with `tlmgr` may save space and keep version numbers fresher than what you find in the Ubuntu and Debian repos.
Comment: Thanks, Johan. These are all great answers, but as one commenter pointed out, real estate is a key issue for netbooks, so a purpose built gui is preferable, so your answer fits best for what I am looking for. And thanks for the (embarrassingly obvious) fact about Chrome - for some reason I thought it was a full-blown OS. :S
Answer: Even if Google Chrome is just a browser, the idea that you can use your netbook as a frontend to a web-based editor and a cloud-backed LaTeX compiler might be tempting, given that the resources of those machines are limited.
I know two of such services:

ScribTeX
LaTeXLab

Both allow you to compile the PDF "on the cloud" and will let you download the PDF.
I don't know how they behave with custom macros and such, but it could be a good idea for smallish and not-so-important projects.
Comment: You can add hyperlinks now. :)
Comment: More options for online compilation can be found under [http://tex.stackexchange.com/questions/3/compiling-documents-online](http://tex.stackexchange.com/questions/3/compiling-documents-online).
Answer: As far as I know, there is no special version of Windows for netbooks. Indeed I am told that the only reason to use Windows on netbooks is because you can use all your regular Windows application. So yes, you will be able to use MikTeX and your favorite text editor.
For Linux based netbook operating systems, TeX Live should install fine.
There even seems to be a port for the N900 phone, no luck for Android based devices though.
(Note that this only applies as long as the netbook is not completely locked down (like iDevices). I do not know if there are currently any lock down netbooks on the market.)
Comment: By the way, TeX Live does work on windows, too.
Comment: Cool to use the N900, that phone is so great :)
Answer: If you are comfortable with a delayed compile, you can write it on one machine and compile on another later. If you are coding LaTeX, presumably you don't need WYSIWYG.
If you want the PS/PDF now, and are online, you can install Dropbox, set up a remote compile script, and therefore let LaTeX reside on a different computer.
Answer: Linux runs flawlessly on my asus 1005ha 10 inch netbook :P So do the ConTeXt minimals.
MikTeX is excellent and will run on Vista/7/XP
TeXLive is available from the ubuntu package manager,
or you can install TeXLive on your own.
WINDOWS is not your only option on a netbook!
Answer: Chrome is essentially a linux distribution, so with some hacking you will be able to get a linux distribution of latex working on ChromeOS. This however, will be without the blessed wonders of a package manager, so you will have to keep track of everything yourself, and download all the extra (non-latex2e) packages yourself. Personally I would just install Ubuntu netbook remix.
Answer: texlive works fine on my netbook (acer aspire one) with different Linux distributions. There is no need to install a special netbook edition. I had no problems with kde4 or gnome.
I installed TexLive via DVD, not via package manager and do my TeX-Works with vim. Maybe you'll like kile more (kile is an LaTeX-IDE, comparable with TeXniCenter).
Answer: You can use virtually any OS supported by the hardware and compatible with TeXLive to get good results. Your choices range from Windows to Linux and also the BSDs. Even though you have limited screen real estate, a good TeX aware editor like TeXWorks can be a very good choice to use as well as TeXLive. The entire TeXLive distribution on my system (TeXLive2010-amd64-FreeBSD) is about 2 GB, so it doesn't eat the entire disk on a newer netbook.
Answer: I just downloaded a small app for android, called VerbTex from Verbosus (verbosus.com)
I allows to write/compile tex documents. Those documents can be stored locally (for free) or in verbosus host (small or unlimited -for a charge-).
local documents can be edited locally but compilation is done only remotely.
One good plus is that packages are already installed.
Answer: I've had great success with a netbook-suitable distro of Linux (Ubuntu Netbook Remix, specifically) and texlive from the repos. You can also set up a source control system (e.g. git, cvs, etc.) or dropbox and keep your notes synced across your netbook, laptop, home computer, server, etc.
Answer: If you decide to go on the windows side you could use a portable installation on a pendrive

LaTeX for netbook OSes


Can you swim to the island on Animal Crossing New Leaf

Question: Can you swim to the island on New Leaf? Is It possible to? I don't know! All I saw was ropes! Can you cut the rope or not?
Answer: No, you cannot swim to the Island in Animal Crossing: New Leaf. The only way to get to the Island is by booking a ride with Kapp'n for 1,000 Bells. The exact requirements for unlocking the Island can be found here. They are:

Get your house built.
Pay off your mortgage.
Wait a day for Tortimer to show up and give you the invite to the island.
The day after that you can go to the island.
Comment: How does HE get through. AND I KNOW!
Comment: @user68528 They probably just lift the ropes up?
Comment: _Through the magic of television..._
Comment: _I_ _know_ _that_... lifting is not possible!
Comment: @animalcrossingrocks24 For you, but not for an NPC. If you're asking us for the way in which Kappa gets out then that's impossible for us to answer because there is no way to know, nor does it really matter. Paths which are blocked off to the player but which NPC can go through have existed since the earliest days of gaming, it's nothing new. The reason for it is that devs often need to restrict the gamers playing area and walls are how that's done, but don't always need to restrict the NPCs.
Answer: No, you cannot swim to the island. You must meet the requirements to unlock it, then once you meet all requirements, after Isabelle loads up your game, Tortimer will talk to you and tell you to meet him at the dock on the beach. When you meet with him, he tells you he has retired and is on this island. He invites you to come, and starting the next day, Kappn will be at your dock in his boat, asking for only 1,000 bells to take you to the island. You can play games and buy island exclusive furniture. When you want to leave, you just talk to the girl at the desk, and tell her you want to go home. Have fun!
Answer: You can't swim to the island.

Before heading to the island, you must pay your 39,800-bell mortgage to trigger access to the ferry service from the dock of your town. Tortimer, sporting tropical wear, will appear "under the spotlight" in the "dark room" as you load your game. That day, speak to him at the dock.
The following day, you can travel to the resort island (AKA Tortimer's Island)! At the dock, speak to Kapp'n to go to the resort island. The trip costs 1,000 bells, and Kapp'n will serenade you twice during the voyage (with sometimes bizarre lyrics). When he starts to sing, you can tap the "A" or "B" buttons or the touch screen to speed the voyage and immediately arrive. He doesn't seem offended. If multiple players are making the trip, Kapp'n will specifically ask whether you all want to listen to his serenade.

Source
Answer: sorry but you have to unlock the island and ride a boat with kapp'n. To unlock the island get 10,000 bells and talk to tom nook while his store is open. Then pay off your next home loan in the post office ATM which is in the bottom left hand corner. After you pay off that the next day Mayor Tortimer will say he retired and went to an island. He will give you an invite to his tropical paradise. Once you start the game go to the dock and talk to Mayor Tortimer. The next day Kapp'n will be there asking you if you want to go to the island for 1,000 bells. Hope this helps! :)
Answer: You cannot swim to Tortimer Island. According to Animal Crossing wiki,

The player must complete several tasks before the option is made available but it can be reached as early as day four. When the player has upgraded from the tent to the house, and then upgraded once after that, Isabelle will introduce Tortimer the next day when the player starts the game. He will ask the player to meet him by the dock. Once at the dock, Tortimer will tell the player about the island. However, it is not until the next day that Kapp'n will appear with his new motorized boat at the dock, which will be ready to take the player to the island for a fee of 1,000 Bells per round-trip.
Comment: What does this answer provide that the existing answers do not?
Comment: ?????????????????????????????
Comment: I don't see any information in this answer that was not already stated in Wipqozn's answer.
Comment: ok i saw ur(your) comment


Suitability of high-level languages for embedded systems

Question: Low-level languages have for a long time dominated the field of embedded systems due to their rapidity and flexibility. As high level languages are becoming faster and faster, might the situation get reversed soon? Can high-level languages become frequent in embedded systems in a near (or not so near) future? What would it take for a high-level language to be suitable for embedded systems?
Comment: I took the liberty of editing your question, which was [not answerable](http://cs.stackexchange.com/help/dont-ask) since you were asking us to predict the future, to a question that, while still opinion-based, calls for answers that back these opinions with facts and experience and calls on computer science expertise.
Comment: I'm not sure how reading the glass ball makes for a good SE question. Community votes, please: subjective?
Comment: To the point of your question, I guess there will always be use cases for low-level languages, those that ride the border of "impossible" and "we can just so do it". Once you have more resources (and tools), you can use higher-level languages. I expect that there is a dependable flow of "impossible" -> "do it with bit-tinkering" -> "many platforms, many languages" -> "Python runs on there" -> "there's an app for that".
Comment: @Raphael That's what I thought first. But who knows SE might be an exception to the rule (like operating systems). I wanted to have a more experienced and more refined opinions on the matter hence my question.
Comment: I can at least tell you anecdotally that the languages for [PLCs](https://en.wikipedia.org/wiki/Programmable_logic_controller) have been gaining more and more high-level functionality over the years.  Programming started as a rough analogy of relay logic systems (so engineers used to designing relay logic could 'easily' program the controller) and have since taken on some aspects of object-oriented programming (in the form of instantiable 'function blocks'.)  Also, previously you had to explicitly specify the memory location for all your 'variables' and now it's usually automatically assigned.
Answer: What is a high level language? What is an embedded system? Once upon a time C was a high level language and a Raspberry Pi would have changed the outcome of major wars, now almost every microcontroller can be programmed with C and we use Pis that run a full-blown desktop OS to turn servo motors. Let's say a high level language is a language that has strong abstraction mechanisms and an embedded system is a system with very limited memory and a processor with few features.
That alone is not enough to say whether this language is suitable for embedded programming or not. The important part is how the programs in the language can be compiled. Many languages (have to) add something called a runtime to the programs. For Haskell for example the runtime added by GHC is about 50k LOC and includes a garbage collector, a scheduler and a bunch of other stuff. That is quite a lot of code for a small chip to handle and might require processor features that aren't present.
Rust is another language that I'd call high-level, but it is possible (in theory at least) to run Rust on many embedded systems. This is because Rust has the possibility to use a much smaller runtime that can be handled by simpler processors and doesn't add as much overhead.
So in summary, the important part is not the features of the language, but how much of those features need support at runtime as opposed to a clever compiler. Garbage collection is typically too difficult for embedded systems, but a surprising amount of abstraction power can be provided without any extra costs at runtime.
Note that in practice you're still limited to C or Assembler in many cases, because you need a compiler that supports your target architecture. Unfortunately it is often the case that the architecture is proprietary and you're limited to using the compiler provided by the manufacturer. That is typically a compiler that supports some flavor of C.
Comment: An important characteristic of C is that number of reserved keywords is small, something like 32 for a simple K&R type of compiler, and functionality such as I/O is through a library rather than built into the language itself. And the technology is well known. A C runtime can be pretty simple and primitive and C cross compilers are pretty common so you can compile your C code on a PC to generate an image and then download the image into the target device.
Answer: There is metaprogramming exists many years ago, so you can do hardware/software codesign in any programming language including Python, Prolog, Lisp or anything you want to use.
Take code generation as a base principle, wrap C code writing to files, or wrap LLVM which can cross-compile directly to your system object code. Implement some class tree represents both source code elements (modules, functions, control structures), and your target model components (finite automata, DSP processing elements,..).
You can construct the target software you want to build by interconnecting these like objects and transform model object to source code objects by your metaprograms. And finally, call code generation method in a recursion starting from the top-level  object, which will generate files with C source code, or directly call LLVM.
Of cause, it is not an easy or well-described method, but it works at least at the level of parametric code snippets composition. As an example, look on CodeMX init code generator suite provided by STMicro. It is a closed-source vendor-provided system, but you can brew your own analog maybe not GUI but script-driven.
Also look on knowledge representation and reasoning, it will give you an idea of how it can be implemented.


Is there an inverse relationship between (future-spot) price and yield?

Question: If the difference between futures and spot prices rises will the yield for the current bond increase as well?
Answer: The difference between futures and spot is related by the carry. Assuming a positive carry environment where the yield curve is upward sloping, then the spot price is less than the futures price.
If prices rise, the yields will change.
Comment: Can you assume that at t-1, if the difference between futures and spot prices enlarge, then at t, the yield for that spot bond will rise? Is this pattern something that is observed regularly?
Answer: The cause-effect relation is the other way round.
The driver is the change in yields, and the effect is the change in the difference between futures and spot.
The fixed income markets (specifically the government bond markets) are among the deepest (i.e. highest volumes and notional balances) and most liquid.
I do not believe anyone tracks the difference between futures and spot (for any underlying security - stocks, FX or commodities) to take a cue that risk-free yields (govie bond yields) to react to a change in future-spot difference.
It is quite possible, for a variety of reasons that the future-spot difference changes while yields show no related changes - because the futures/spot difference can change to due to limitations in the liquidity of the underlying so that any arbitrage opportunity cannot be effected due to large transaction costs.
Lastly, when you say yields you need to be more specific as interest rates come is quite a few flavours.
The interest rate most relevant to spot-futures arbitrage argument is the repo rate. This is the rate which is likely to be most responsive to the change in the difference between futures and spot.
And one more really last thing, the arbitrage argument is really for the spot-forward-repo rate trinity. For futures, a convexity adjustment (on top of the forward price) is also relevant. So a change in underlying volatilities could theoretically increase the futures price (while spot and repo rates remain unchanged). Although, to my best understanding is will normally be quite small to bother.


Hiding job title on blogs using Facebook comments

Question: On Techcrunch or other blogs using Facebook comments, I noticed that your job title displays next to your post. Is there any way to limit the privacy settings so it only displays to friends versus public and does not show up outside Facebook?
Comment: The only thing I was able to do was delete my job and my schooling. But I don't like it. Anyone have another solution?
Comment: This has been bothering me for the better part of a day- kept thinking I fixed it, only to make a new comment and still find my job/employer info (which I'd listed as "only me" privacy). Note the key in the instructions above: after you post the comment, log-out of Facebook and then view your comment. You will notice the personal info is gone (mine just lists my city now). My employer IS INDEED available to "only me"- I just happened to be ME everytime I viewed it.
Answer: Sure.  Just edit your profile (or timeline) and change the privacy setting next to your work info to "Friends".  The same setting controls its visibility both on your profile and on third party sites that use Facebook Connect.
Check the comment when you're not logged in to Facebook (or from a different browser), and you'll see that the sensitive info isn't displayed.
Comment: That did not work. I even tried to set it to "me only" and it still shows my title and employer in my posts. Anyone else know how to fix this? There has to be a way. I see other posters that just show city and state.
Comment: Could it be a caching issue?
Comment: It may not change immediately; try checking it the next day after changing the privacy setting.
Comment: Thank you. This works. If your information is set to friends, only you and your friends who visit that comment on an outside website would see the information. It is a little disconcerting, but I am glad I am the only one who can see it.
Comment: This no longer work anymore ??
Answer: As mentioned by @mark4o, the privacy settings within the info section indeed takes care of managing your identity.
Be sure to first check whether your info is available by using the "view as" feature.
A second place to do testing is the comments plugin documentation page. Have two windows open, one as logged into Facebook the other not.
For example here is my profile set for public

where as to friends,

Now writing a comment to TechCrunch

Notice I am logged into Facebook so it is pulling all the information as it would be silly to hide information from myself when logged in.
Watching the same page incognito.

You can see the comment for yourself.
Answer: I like adding a fake job description, simply to describe yourself.
I currently have something like, "all-round nice guy @ Earth", although that might come across as awfully smug. :)
Answer: Just noticed it myself. You can indeed check this in incognito modus (chrome), check what info you still see (like town, or company/work), then goto your ABOUT section in facebook and change the setting of privacy (url is https://www.facebook.com/YOURUSERNAME/info ) and change setting from 'public' into 'friends' or whatever. Then refresh the screen in chrome incognito and check what's still shown. Also change that in the ABOUT section and so on.. Mine only shows my name now!


Kivy: config.ini [Input] section: My touchscreen settings don't apply

Question: I am trying to use an Elo Touch monitor to work with kivy. At first i calibrated the monitor with xCalibration wich worked fine:
Calibrating EVDEV driver for "EloTouchSystems,Inc Elo TouchSystems 2216 AccuTouch® USB Touchmonitor Interface" id=6
    current calibration values (from XInput): min_x=315, max_x=3699 and min_y=3627, max_y=459

Doing dynamic recalibration:
    Setting new calibration data: 309, 3686, 3641, 457

--> Making the calibration permanent <--
  copy the snippet below into '/etc/X11/xorg.conf.d/99-calibration.conf'
Section "InputClass"
    Identifier  "calibration"
    MatchProduct    "EloTouchSystems,Inc Elo TouchSystems 2216 AccuTouch® USB Touchmonitor Interface"
    Option  "Calibration"   "309 3686 3641 457"
EndSection

Now I am trying to set up the Touchdisplay for Kivy.
Touch seemed to be working, but on the lower screen there was some kind of offset.
I think I need to change the setting in the kivy/config.ini at [input].
I changed it to this:
[input:]
mouse = mouse
mtdev_%(name)s = probesysfs,provider=mtdev
hid_%(name)s = probesysfs,provider=hidinput, min_abs_x=300,max_abs_x=3000,min_abs_y=3636,max_abs_y=472

My Problem is now, that these changes don't apply. While i start my Kivy App the logger tells me:

[INFO   ] [ProbeSysfs  ] device match: /dev/input/event0
[INFO   ] [HIDInput    ] Read event from </dev/input/event0>
[INFO   ] [HIDMotionEvent] using <EloTouchSystems,Inc Elo TouchSystems 2216 AccuTouch® USB Touchmonitor Interface>

And most important:
[INFO   ] [HIDMotionEvent] <EloTouchSystems,Inc Elo TouchSystems 2216 AccuTouch® USB Touchmonitor Interface> range ABS Y position is 184 - 3932

What am I doing wrong and why wont my changes apply to my app?
Answer: Have you tried applying your changes to root?
sudo cp ~/.kivy/config.ini /root/.kivy/config.ini


How can I clean stained garden rocks?

Question: I have some white garden pebbles which  are now  yellow with trace of rust. I have tried to soak them in bleach diluted with water without success.  Could I receive suggestions of an appropriate material to remove the rust?
Comment: Bleach is no good against rust. Use acid.
Answer: The iron oxide from rust is not soluble in high pH (basic) solutions such as bleach. If you want to remove the the rust, you need an acid such as muriatic acid (wear PPE, follow label instructions). I would recommend an oxalic acid based product such as Bar Keepers Best Friend (I have no affiliation).  In my (pseudoscience) experience, oxalic acid its more effective at sequestering rust (when scrubbed) than anything else I've used including nitric, muriatic, and sulfuric acid. I would be cautious if the white rocks are marble as acid can disslove marble into oblivion.
Comment: Marble can also become quite porous with exposure to the elements, so the yellow color may not just be on the surface.
Answer: One of the best rust removers is very strong reducing agents such as sodium hydrosulfite and sodium bisulfite. Many commercial rust removers are based on it such as Iron Out. It takes a few minutes and no acid are involved. Read instructions on the label and follow manufacturers directions.
Answer: You don't. You need acid to remove the rust, but since your pebbles are white they are very likely to be limestone or marble. They will dissolve in the acid faster than the rust.
Your best solution is to try and scrub it off mechanically, get new pebbles, or just learn to live with the rust.
Answer: H2O2 (3%, from the drugstore) alone might do the trick, but adding a little vinegar should react with the iron oxide and keep it in solution without dissolving much of the pebble.
Answer: As mentioned from A.K. something containing oxalic acid should do the trick.
That can be explained by oxalate acting as a chelating ligand. The structure of oxalate is basically two carboxylate functions covalently bound to each other, if deprotonated a bidendate ligand results. As the dianion coordinates to the iron a soluble complex will be formed which should be easily washed off.

How can I clean stained garden rocks?


I bought Bit Coins while on a Bidding site. They were bought with my Credt card. How do I trace them?

Question: I bought Bit coins on a Bidding site that only used Bit Coins. I never used them. How can I find them?  This was almost 6 years ago. It was $10.00 worth and that bought 10 bitcoins... Thanks
Comment: do you remember the website you bought it from ? or your private key ? or did you buy it from an exchange ? if yes, which exchange ? you can log back in to exchange if you still have the login details
Answer: You can go back and check your credit card records for the purchase.  That should at least give you a name of a company.  Contact that company (if they still exist), and see if they can give you access (assuming you lost your credentials).  If they can, and they were storing your bitcoin for you, then you can transfer it to a wallet you control.  If you already transferred then out when you bought them, but lost the key/password/data to your wallet...then you are just out of luck.


Does the FAA allow a jet bridge to approach an aircraft that has engine #2 running?

Question: Does the FAA allow a jet bridge to approach an aircraft that has engine #2 running?
Answer: On a two engine airplane, Engine #2 will be on the opposite side from the jetway, and keeping the engine running while the bridge is connected on the other side is not an issue.
(see related question: How are engines numbered?)
On a 4 engine airplane, Engine #2 will be directly behind the jet bridge, and should be shut down before the bridge is extended.  This is for the safety of the engine, to avoid ingesting any debris from the jet bridge, or debris dropped by people, rather than for the safety of the people (who are unlikely to be sucked in by an engine at low power).
Comment: If the engine is running at a low / idle power, it would not suck in a person.  But if a passenger / crew dropped anything small: pocket change, pens, keys, etc, those could be sucked in and damage the engine. (edited for clarity)
Comment: Many thanks!!!!!