What is the best position for clear filter button in a filter list

Question:
Here I have an example screen for filters in an overlay where clear filter button (which appears only when any of the filters is checked) is below the list of filters. Is it ok to place it here or something is very wrong with this design, UX wise?
Answer: Short answer: It's fine to put the clear-all button in the bottom left.
Long answer: There is not enough info here to talk about the UX of your site, as we would need to know much more about the users, where they have been to get to this screen, what motivates them, etc.
We could talk about the UI, although as this is a simple overlay there is still very little to go on.
Nonetheless, for what it's worth, I would be interested in a couple of points:

Why are the filters are separated by a horizontal line - is it clear to the user what the difference is between those above and those below? Is there a different filtering mechanic that you are trying to signal to the user? If so, this is not clear from your screenshot.
'Delivered' and 'Shipped' are looking a little lonely there! What are they anyway - if I select neither, what data will I get? How about if I select both? Maybe radio buttons would be more appropriate? Or remove the 'Delivery Status' checkbox?
A lot of empty space here - might look better in two columns, rather than two horizontal sections.
I would use 'Clear all' instead of 'Reset all' for clarity (the button doesn't actually do the resetting - that happens when you click 'Apply'), but that is just personal preference - you could speak to your users to see what they prefer.
The position of the clear-all button, after all the above have been addressed, may be better off nearer the apply button, or next to the header, or it may not - again, see what your users think. Either way, I'm pretty sure they will be able to use the button effectively :)

Hope that helps (sorry if not quite what you asked for!)
Comment: thanks for the answer! actually confusion was about the position of clear filter button. data here I showed is edited one actual data is different. horizontal line was to separate all filters when adjacent filters were checked it was difficult to differentiate both of them. thanks again for the feedback will work on that. cheers :)
Answer: Your proposal is clear to understand and will work. However, I was thinking of a different way to layout elements.

The title refers to the whole Dialog so you could place it in the centre
Deliver & shipped checkboxes were breaking the direction of the main checkboxes
"Reset All" acts as a Select/Deselect all checkbox (or just the former), so placing it where this checkboxes usually appear (in the top) might respond to user-expectation

Other notes:

Don't make the button invisible and suddenly appear when a checkbox is selected. Make it inactive (with less opacity) and activate it when it corresponds. This way the user knows, from the start, he has that option.
A useful way of using the button could be "Reset all to default value" rather than "Deselect all". This depends on your case but if there are a set of options that could be considered default, maybe because of their necessity for the table to be understood or because you want to show your recommended fields, it might be good to transmit it to the user.
Answer: The positioning of reset option is in correct position i.e to the left. In case if it's placed on the right with other button and user accidentally clicks on reset instead of Apply. Instead of reset you could replace the text with clear all.
Comment: thanks man for the answer. great relief for me as I was not the only one thinking it is right ;)
Answer: I think the position you have makes sense given that users tend to work from top to bottom. However, I think just as important as placement are visual appearance and transition. The bold / red style calls appropriate attention. You can also use subtle non-annoying animations to call attention.


Pi for Google+ Hangouts

Question: I'm trying to find out if the Pi could work for a Google+ Hangout. I'm guessing no but wondering if anyone is trying to get it to work. Will the new webcam version make it easier? We want to set up a dedicated Pi station for people to do Google hangouts.
Comment: This is an awesome idea.
Comment: It could be possible with HTML5, Video and some Webcam plugin ( i dare say Java) But there needs to be an API or Driver avialble for the video feed. You can try and get something like YAWCAM to work on the Pi? Then you one foot in the door. But that is more a standalone webpage. You still need to integrate into the Googel Hangout API somehow? Good luck
Comment: are you trying to use PI to host your hangouts or be a headless video/audio participant of hosted hangouts? no. 1 is done fairly easy; no. 2 could be a problem. If you attempt to use hangout for the first time with Chrome, it will ask you to install audio/video plugin, given that I am assuming this is not going to be a one-liner to do with HTML5. Besides, USB webcams with RPI will be giving you ~10fps which is far behind most user's expectations so you may want to wait for the RPI camera for smooth picture.
Answer: Just a heads up that the Pi lacks audio in; you'll need a USB sound card. You can pick one up from somewhere like Amazon though - for a G+ hangout, even the really cheap ones will be fine.
Comment: so does it lack video in :) I guess they will be using a web cam anyway and there its mic comes handy.
Comment: Many webcams have mics, too. And there are video digitizers with stereo audio, composite and svideo inputs in one box that you could use to attach analogue kit.
Comment: The question mentioned using the upcoming RPi camera for video in; just pointing out that this solution doesn't allow for sound. I would've posted it as a comment, but apparently I can't post comments yet.
Answer: I spent a day trying to use Google Hangouts. I firstly tried installing Chromium OS V0.5. This booted to a black screen on my RPi2. From all reports I'm not alone with this… it's pretty buggy.
I then installed Raspbian, and the Chromium browser. Hangouts works fine, but I was experiencing ~0.5 second audio lag and asynchronous ~1–1.5 second video lag, so I gave up. Apparently this lag is also common. I'm fairly sure Hangouts is decentralised/P2P, but I experienced this lag even on the same intranet.
As an addendum:

Skype is not available for the Pi. There is no ARM build, and the web version doesn't offer a Linux plugin for video chat.
Jitsi isn't available in Raspbian either (missing dependencies), and it's always been super-glitchy for me on my normal computer anyway.
I trialled Ekiga on my normal computer, and the quality was so terrible that I didn't even trial it on the Pi (although it installed fine).
Answer: Install Google's Chromium Browser on the Raspberry Pi:
apt-get install -y chromium-browser
Then, using this, browse to http://hangouts.google.com
Worked for me after a firmware upgrade (https://github.com/guysoft/OctoPi/issues/267) on a Pi 2 B+.

Pi for Google+ Hangouts


Where do I find monster carapace?

Question: I've been looking everywhere for monster carapace but I cannot find it. Any idea where it's found? I need to to craft mastercraft armour. If you know where it's for me then what monster do I kill for it?
Comment: Always check through your items at a Blacksmith or Armourer in the Dismantle tab to ensure it's not an item which can be got from dismantling another item.
Answer: Similar to my answer here, talking about Monster Hide, you can dismantle materials such as Wyvern Hide into Monster Carapace.

According to other sources, you can also purchase it at high level armorsmiths, though I have not seen that.
You can convert these items into monster carapace:

Basilisk Hide
Forktail Hide
Wyvern Hide
Answer: I was looking for monsters to get monster carapace and monster hide needed for upgrades of Witcher Gear. Unfortunately I had already slain all big monsters, done all quests, destroyed all monster nests, etc (OCD anyone?).
But I found this cave I visited before with a bunch of respawned Devourers close to the entrance, a Harpy or 4 furthermore down the cave and 3 Erynia flying monsters at the bottom. On my first visit to this cave I had looted and killed everything, so imagine my joy that all these monsters respawned in between visits.
And - JAY! – I got me 3 Necrophage hides amongst others. You can find the cave next to the fast travel point of Clan fordarroch Forge – Skellige (south-west of Kaer Trolde).
Comment: Would you mind adding the exact location of this cave, possibly with a screenshot? I think I know the one you mean, but I can't be certain.

Where do I find monster carapace?


iMessage inquiry to ease my mind

Question: I have discovered that at certain times, my iMessages are delivered as SMS instead; which is perfectly ok with me, considering I have it set up to do so.  My question is, under what conditions are the messages sent as SMS with both myself and the recipient does not necessary been in a wifi area to receive or send iMessages...is it that when the recipient has their phone powered down that it is sent as SMS, and if that is the case...why is it that I receive messages sent as SMS instead of iMessages from the same recipient...what exactly does "...when iMessage is unavailable" mean??? Thanks in advance for any/all response(s)...
Comment: It will send as SMS if your side appears to be offline, or on lower quality data network. You're asking multiple questions here, could you summarize them?
Comment: Thank you for your response Robuust...my question refers to the statement that a message will be sent as SMS when iMessage is unavailable. I was inquiring to find out exactly what conditions make iMessaging "unavailable" and was curious if a phone being powered down was a possibility; in addition to wondering why I at times, receive a message as SMS, when I have a very strong wifi and/or cellular signal.
Answer: If the sending phone has no 3G or wifi coverage it will send as an SMS message. Otherwise it gets sent as an SMS. If the receiving phone doesn't acknowledge the message after 30 seconds (because it doesn't have 3G or wifi coverage, or it's turned off) the sending phone will give up on iMessage and send it as an SMS.
If the sending phone has turned off the setting to "Send as SMS" then it won't send as SMS unless the user manually does it.
EDIT: If the receiving user has Messages set up on their Mac running Mountain Lion or Mavericks, and the phone is out of data coverage, the message could be received by the Mac and not the phone.
Comment: Ok thank you for informing me to do so... I found this site on a whim via "google search" trying to find answers to my questions, so I don't really know the ins and outs about how things are done. I will say that I have bookmarked it, to use if I ever encounter another concern that baffles me and I am unable to figure out myself or find an answer to. Thanks again for your help.

iMessage inquiry to ease my mind


How can C# access JavaScript variables in Unity 5?

Question: I have a static public boolean in a JavaScript and I want to access it in a C# script. When I tried the way that you would call a static variable from another script though, it said that the variable and script weren't recognized. Here is my JavaScript code:
public static var ItemPurchased = false;
function OnGUI () {
    if (GUI.Button(new Rect(10, 90, 190, 24), "Click here to collect water.")){
         ItemPurchased = true;
}

I do believe that the JavaScript is correct. On the other hand, here is my C# script:
public static bool itemowned = false;
void Update () {
    if(PurchaseItemScript.ItemPurchased == true){
        itemowned = true;
        PurchaseItemScript.ItemPurchased = false;
    }
}

PLZ HELP!
Answer: Looks like your class is not static. You need to initialize it before using:
public static bool itemowned = false;

private readonly PurchaseItemScript = new PurchaseItemScript();

void Update () {
    if(PurchaseItemScript.ItemPurchased == true){
        itemowned = true;
        PurchaseItemScript.ItemPurchased = false;
    }
}

or, make the PurchaseItemScript class static.


Wireless communication over long distances

Question: Would like to communicate between an Arduino and a PC but over a
distance of 2500+ feet outside in the open, wirelessly. What would be
the best way of doing this? The communcation devices I have found
(xbee,...) dont go the distance.
Comment: There's basically two options I see: get one of those super long range radio modules, like XBee that's rated for 1 mile distance, or get a cellphone module and communicate over the internet using the cellular network.
Comment: related: http://electronics.stackexchange.com/questions/68587/long-range-rf-communication
Answer: What sort of data rate do you need to maintain?
Long range communication is quite possible in open areas with very low power - a project I am currently working on incorporates data transmission over 500 KM using only 25 mW (miliwatts) of tx power - this of course relies on a line of sight, and data transmission is at only 50 baud. Even without line of sight, omnidirectional communications outdoors are quite easily achievable over the range you're looking for.
As others have mentioned, matching your antennas with your intend usage patterns is important - can you give us more detail as to requirements/use patterns?
Comment: Can you recommend a good resource for reading up on appropriate frequencies, antenna types, gain, etc?
Answer: One factor your options depend on is how the data transfer rate you need over that distance.  More of the long range, low power applications reduce in throughput as the distance increases.
For example, the XBee Pro 50mW Series 2.5  operates at 2.4GHz with a range of 1 mile and has a data transfer rate of 250kbps.
The longer range XBee Pro 900 XSC operates at 900MHz and has a range of over 15 miles, but a data transfer rate of only 9.6kbps.
You could also look into directional antennas and signal amplifiers.
Comment: *only*" 9.6kbps... I remember accessing the internet with my 2.4kbps modem back in the day...
Comment: yeah, but did you access the internet from 15 miles away wirelessly with something near the power of bluetooth.
Comment: QRSS lets you transmit 2000 km with 10 mW.  The data rate's a bit low, though, around 0.0001 kbit/s.  :D
Answer: Wifi maybe if you used range extenders for your network, or if you have the funds you can use the cell network with a module like these from sparkfun.
Answer: There are XBees that communicate about 1 mile (~4800 feet?).
http://www.ladyada.net/make/xbee/modules.html
Maybe you can even improve the range with a better antenna.
Comment: If you swap the antenna there are requirements for wire loss to keep from violating FCC. You will get the same max range regardless of antenna. FCC gives a limit for your power radiated in the direction of maximum radiation. So omnidirectional will hit the same boundary as a directive antenna, unless I am mistaken.
Answer: As was mentioned the XBee with the 50mW antenna should do this. You want to make sure
you order the high gain antenna. There is a series of XBees that come with a coax connecter
on the top. IIRC the highest gain antenna is the whip antenna with the coax cable.
The document that discusses the antenna gains is application note XST-AN019a from MaxStream.
Answer: We have successfully pushed this communication more than a mile on our miniature UAVs without ever coming close to loosing communication.
It is a serial modem our buadrate at this time was 9600.
[http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xtend-module.jsp#overview][1]
good luck !
Comment: Will I be able to achieve about 700m range in absence of LOS using this? Or will you suggest me a better solution, if any. (path is not heavily obstructed. there are only 3,4 trees blocking the perfect LOS. otherwise, got a reasonable LOS). Thanks..
Answer: You could use standard Wifi 2.4Ghz or 5GHz radio units with panel, yagi, or parabolic directional antennas. Use an Ethernet shield on your arduino and the ethernet port on the computer (or your network). This distance is completely achievable with this type of setup, and supports high bandwidth.  I have used enGenius and Deliberant brands with no issues over such distances.
For a cheaper solution, you may be able to achieve this with a couple of standard wifi routers like the linksys WRT54GL running DD-WRT or other firmware which allows customization of the ACK timeout, and by using some small directional antennas such as this, or at l-com.com check out their selection of 2.4GHz antennas with TNC connectors.
Answer: I remember a 100 mile link in South America that was reliable with 100 mw on at 14 MHz with a buad rate of of 2 or 4 using a extremely stable oscillator and very narrow filter all built with analog parts.
I should be easy today if you can get a frequency from 3 to !50 MHz. A GPS can be use to synthesize as good a clock as you can find and modern digital signal encoding and decoding messages that can pull signal you can't hear in solid copy. If you put a narrow filter over a stable frequency an amazing amount of noise can be filtered out. The using a phase shift decoding the computer can pull out things I can't see or hear.
Of course the more narrow the filter the lower the baud rate.
In the US and Europe access to frequencies for data radios is difficult to impossible. If you want anything that approaches prompt data access you need 3 to 5 bands scatter over the range from 3 to 30 MHz and their not sure every day. The frequency range of 50 to 150 MHz is relible from 3:00 AM until noon as meteor scatter. It needs at lest a 100 watt radio with an antenna gain 9 dBi. It has been done with and ERP of 100 watts but connections corrode and parts age so you need a safety factor.
It's been 10 years since I worked in Central, South America, Mexico or Africa. Their frequency  allocation at the time were much more flexible. Working as contractor I told my client what I could find out about the law and left it up to him. You can make a great 7 MHz NVIS antenna on a Caboose or over the boiler of engine on a train that will give almost constant location of a train in Africa for 500 miles. Double back on its self and does well on 3.5 MHz at night.
Comment: Nice story, but it doesn't even try to answer the question. Remember that this is not a traditional discussion forum.
Comment: It was late and I got off track. Some ham in California are using WiFi radios for peak to peak  communions for reapers and rebels are building an encrypted system for disaster traffic that can't be transmitter as plain text.


Does an attorney in Germany have to prosecute own relatives

Question: In German penal law, does an attorney (Staatsanwalt) have to prosecute own relatives (parents children, siblings, etc.)?
If no, by what law (I could not find any that would provide them with that right)?
If so, are there some case examples?
Comment: My strong guess is that ordinarily it would be conflict of interest for him to do so, that he or she would be forbidden from doing so, and that a different attorney in the office (or someone assigned from a neighboring office or more central office if no one was available in the office) would be assigned to that case instead. The answer is probably not in the German penal law and is instead probably in the law regulating lawyers or the law and regulations pertaining to prosecutor's office organization.
Comment: Good point. With your hint I could find [this](https://de.m.wikipedia.org/wiki/Verbot_der_Vertretung_widerstreitender_Interessen) in German Wikipedia. Does this also apply to attorneys?
Comment: The material you cite from Wikipedia discusses rules of conduct for attorneys.
Comment: Are you referring to a prosecutor (Staatsanwalt) or an attorney-at-law (Rechtsanwalt)?
Comment: The former, as stated in the question. Unfortunately the translation into English is [ambiguous](https://www.dict.cc/?s=staatsanwalt).
Answer: Attorneys are normal officials (Beamte), so the laws about officials apply to them. So e.g. for North Rhine-Westphalia (there are similar laws in the other states) § 47 Gesetz über die Beamtinnen und Beamten des Landes Nordrhein-Westfalen (Law about officials of the state North Rhine-Westphalia):

(1) Beamtinnen und Beamte sind von Amtshandlungen zu befreien, die sich gegen sie selbst oder Angehörige richten würden, zu deren Gunsten ihnen wegen familienrechtlicher Beziehungen im Strafverfahren das Zeugnisverweigerungsrecht zusteht.
(1) Officials are to excuse of official actions, that are against them or their relatives, if they have the right to refuse to testify against them in criminal proceedings.
(my bad translation)

These relatives are according to § 52 Strafprozessordnung (Code of criminal procedure): fiancée, spouse (even ex-spouse) and any "person who is or was lineally related or related by marriage, collaterally related to the third degree or related by marriage to the second degree."
So attorneys do not have to prosecute their relatives.
In some (but not all) German states this is not only a right of the attorney, but they are forbidden to perform official actions in processes against their relatives. So e.g. in Saxony-Anhalt, § 14 I n. 2, 3 Ausführungsgesetz des Landes Sachsen-Anhalt zum Gerichtsverfassungsgesetz (Law of the state Saxony-Anhalt to implement the Courts Constitution Act)

Ein Beamter, der das Amt der Staatsanwaltschaft ausübt, darf keine Amtshandlungen vornehmen, wenn er
[...]

Ehegatte oder Eingetragener Lebenspartner, Vormund oder Betreuer des Beschuldigten oder Verletzten oder einer Partei ist oder gewesen ist;
mit dem Beschuldigten, dem Verletzten oder einer Partei in gerader Linie verwandt oder verschwägert, in der Seitenlinie bis zum dritten Grade verwandt oder bis zum zweiten Grade verschwägert ist oder war;

[...]
An official, who exercises the office of a prosecutor, is not allowed to perform official actions, if he is or was
[...]

the spouse or registered life partner, guardian or legal curator of the accused or of the injured or of a party;
lineally related or related by marriage, collaterally related to the third degree or related by marriage to the second degree to the accused or to the injured or to a party;

[...]
(my bad translation)


How can i record my digital piano's sound on PC?

Question: I have a roland rp-302 digital piano.I love it's sound the problem is that i have gone sick of the VSTS such as addictive keys,ivory etc. and want to use the real sound of the digital piano itself in my tracks and videos.How can i record it? i am able to connect it my PC speakers and get output but it isn't recording in audacity or any other similar program?
Answer: If you simply want to record the piano with Audacity, you will need a stereo line input on the computer. You connect the OUTPUT stereo phone jack(⅛ inch I think) from the RP-302 to the line input on the computer using a suitable stereo cable.
If your computer doesn't have a line input, you would need to buy an audio interface with the relevant inputs. A dedicated audio interface will always give you better signal quality than using the computer's internal sound circuitry. If you do this regularly, you should think about getting a dedicated audio interface either way.
Note: Using the computer's built-in sound inputs will add a lot of latency(delay) to the signal. This shouldn't really matter for a solo piano, unless you need to monitor(listen to) the piano through the computer while recording. But hopefully, the piano will continue to output the sound itself while connected to the computer.
If you are having problems accessing the input from Audacity or any other audio software, try installing an ASIO driver like ASIO4ALL. This driver will also lower the latency and give you access to some other useful settings.

Useful links
Audacity FAQ:Recording - How To's
SOS - Choosing An Audio Interface
Questions - Computer Line Input
Questions - Audio Interface
ASIO4ALL info

if you have any questions, use the comments below.


How can I prevent invalid clicks on my AdWords campaigns?

Question: I was wondering if there is anyway you can block or exclude people from submitting multiple fake ip's online . For example I have a google pay-per-click campaign set up on adwords. I downloaded a program in minutes which enabled me to hide or give out a fake ip address which also allows you to use a different ip each time. I tried this out on my own link on google which in turn got through adwords and I was charged for the click. My question is how would you be able to counter or block someone who continuosly clicks on your link with a different fake ip each time?
Comment: Are you talking about clicking on your Adwords link?
Comment: My sponsered link on google?
Comment: Restricting visitors from your website would not stop them from clicking on your AdWords advert.
Answer: Fortunately Google is aware of this scenario and will automatically detect fraud patterns like this and declare the clicks invalid. As long as you're not part of the click scheme you should be ok. So don't use that tool to click on your ads anymore or else you run the risk of being considered a fraudulent user.
Answer: What you can't do:

Prevent people spoofing their IPs.
Block IP addresses on sites you don't
control (e.g. Google search results).

What you can do:
Google employs automatic filters to combat click fraud and invalid clicks, but has a number of suggestions for things you can do to monitor and detect invalid clicks yourself:

Track invalid clicks already captured by Google using the Invalid Clicks column.
Monitor the conversion rate of clicks to look for sudden drops or unexpected behaviour.
Enable click tagging and understand how to track clicks to your website.
With enough information, you can request an invalid traffic investigation.
Relax. Click fraud would be a huge threat to Google's business if they ignored it, so it's in their interest to actively counter it and investigate your concerns.
Comment: I believe you can block IPs on search ads using IP Exclusion. If you have access to one of the click fraud programs, you can easily enter the IPs used by the program (probably a bunch of open proxies). If you want to go further, you can send the program itself and data you've collected showing that it works to Google's AdWords division and let them include it in their anti-click-fraud defenses. I'm guessing they probably already track such programs, but the more obscure/newer ones may escape their reach.


How to downgrade to OS Mavericks 10.9.5 from a new pre-installed Yosemite 10.10.1 iMac late 2013?

Question: I need to downgrade to OS Mavericks 10.9.5 from a new pre-installed Yosemite 10.10.1 iMac late 2013, can you help me out? Is it possible considering Yosemite was pre-installed?!
Comment: Duplicate? [Installing Mavericks on a brand new machine that shipped with Yosemite pre-installed?](http://apple.stackexchange.com/q/158587/120171)
Comment: Voting to leave open, as the 2013 is perfectly capable of running Mavericks with no trickery required.
Answer: The first pre-installed OS on the iMac14,1/iMac14,2 was Mac OS X 10.8.4. You may install any OS version newer than that one.
If you have any personal data on this Mac, save it to an external drive.
After creating a bootable thumb drive using the Mavericks installer, boot to the thumb drive, erase the main disk and install Mavericks.
Restore your personal data from the external drive. Some of the data (Photos library, probably your Mail data) - if you had any - is not backward compatible with the apps (iPhoto, Mail) used in Mavericks.
Answer: The short answer is – yes, you can.
The not-so-short answer is, it's messy. You can't downgrade, according to all the problems I had with personally trying to. But then I found a working method which I carried out on my own Mac. Sure, it worked, but my Mac is different from yours. It should work, but there's not 'warranty'. As long as you have all your files backed up to an external hard drive, you should be good.
If you want, you can just try to downgrade using a Mavericks installation package.
Nonetheless, here's my working method. Prepare...
First, find an image of OS X Mavericks that you want to downgrade to. Right click on it and select Show Package Contents >> Contents >> SharedSupport and extract InstallESD.dmg to the Desktop. Now convert it to a bootable image (it's hard, but feasible). Transfer the bootable to an external hard drive.
Then you've gotta back up your Mac using TimeMachine.
Then go into Recovery Mode by restarting your Mac and holding down the Command and R keys before the boot sound.
Now open Disk Utility (from the top menu), select the very top disk on the left (above Macintosh HD), open the Partition tab, and add a partition by clicking the + (plus) icon below. Call it whatever you want, adjust its size to about halfway (for now) and click Apply.
Now insert your external hard drive. In the top menu choose Images >> Convert and find & click on the Mavericks image from the inserted drive. Click Convert and then Cancel (yes, you read that correctly).
Now your image appears in the left bar of Disk Utility. Click on it and now drag the partition which you created earlier (should be below Macintosh HD) to the Destination field. Click Restore (and then Erase if it asks you for confirmation).
Now wait.
Once it is finally over, go back to the very top hard disk and to the Partition tab. Remove the old Macintosh HD partition by selecting it, deleting it using the - (minus/dash) icon, and resizing the newly created Mavericks partition to the maximum size remaining. Apply the necessary changes and wait again.
Now finally reboot. Congratulations, you have successfully downgraded from Yosemite to Mavericks without any hassle (might have understated the difficulty a little).
If the instructions I listed are impractical, then sorry for wasting your time. But be warned in advance, that 'playing around' with disk partitions is a joke of no kind. One f*** up and you might lose the Recovery partition. And that is one thing that no Mac user wants to do.


Is specific circuit debugging questions on topic?

Question: I have a picture of a circuit that is leaking current from 4 double AA batteries. I wish to post a question regarding what procedure to use to debug the circuit to find the current leak. Is this question on topic? If not, how can I frame the question to be on topic? Thanks.
Comment: Don't sweat the whole on/off topic thing. If you haven't already, I'd recommend you frame your question in the form of expected vs actual behavior, along with the schematic (if available). Good luck!
Answer: It's good that you have asked on meta first.  Here's the disposition towards troubleshooting questions.

Questions on the repair1 of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design2 of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?

1 incl. troubleshooting
2 this boils down to having the schematic
p.s.  Troubleshooting usually requires dialog and brainstorming.  StackExchange Q&A format is good for wiki-style information, but the Q&A format is not the most graceful for dealing with troubleshooting requests.


How to fix "QiskitChemistryError:PySCF is not installed"

Question: I'm trying to simulate LiH using VQE. But I keep getting the error
QiskitChemistryError:PySCF is not installed
And I tried several ways to see whether my driver for the molecule was typed wrong. But couldn't find any. I again downloaded the VQE molecule Jupyter notebook from the qiskit documentation and tried running it without any modification. It still gives me the same error.
(Running with the updated qiskit version 0.20.0 on Windows10)
Answer: Typically you would need to install it through pip install pyscf, however I believe pyscf does not support Windows. If you look on their installation guide they give some instructions for installing the library, but on Windows you probably need to either use the ubuntu subsytem for Windows or set up a VM.
Answer: I was able to run PySCF on Windows by first downloading Visual studio installer. After installing it, you have to install desktop development with C++ in there and it'll solve your issue most probably.

How to fix “QiskitChemistryError:PySCF is not installed”


How to check for purchased feature (InApp Purchase) when user delete and reinstall the app?

Question: I am working on a project which include InApp purchase functionality. I am done with it and I store a key in NSUserDefault when user purchase the feature and check for the key to unlock the feature of app if user has already purchased it. But now the problem is that what if user delete the app and reinstall it, then all data of NSUserDefault get deleted. So what is the solution to check for unlocking the feature in that case??  Please tell me the possible solutions.
Thanks!!
Comment: you can use the Restore Inapp Purchase Option
Comment: You have to give the Restore Inapp Purchase Option otherwise your app will get rejected.
Comment: I have already restored the transaction but now the problem is how to check if user has already purchased the feature or not at launch time in order to unlock the feature??
Answer: - (IBAction)RestoreBtnClicked:(id)sender
{

 [[SKPaymentQueue defaultQueue] addTransactionObserver:self];

  [[SKPaymentQueue defaultQueue]restoreCompletedTransactions];
}

// Then this is called

- (void)paymentQueueRestoreCompletedTransactionsFinished:(SKPaymentQueue *)queue {

    NSLog(@"%@",queue );

    NSLog(@"Restored Transactions are once again in Queue for purchasing %@",[queue transactions]);

    NSMutableArray *purchasedItemIDs = [[NSMutableArray alloc] init];

    NSLog(@"received restored transactions: %i", queue.transactions.count);

    UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:
    @"Purchase Restored" message:nil delegate:
        self cancelButtonTitle:@"Ok" otherButtonTitles: nil];
    [alertView show];

  for (SKPaymentTransaction *transaction in queue.transactions) {

        NSString *productID = transaction.payment.productIdentifier;

        [purchasedItemIDs addObject:productID];

        NSLog (@"product id is %@" , productID);

        // example if ([productID isEqualToString: @"youruniqueproductidentifier]){write files} else { nslog sorry}
    }
}

Comment: @Shangari..I have already restored the transaction but now the problem is how to check if user has already purchased the feature or not at launch time in order to unlock the feature??
Answer: When you'll submit your app to the AppStore, most likely it will be rejected since your solution doesn't provide an ability to restore user's IAPs on different devices using the same Apple ID. You are responsible for adding this feature to app. It might happens automatically or on user's demand, based on your UI flow.
Before start to implement, read related Apple Documentation
After you check that user is already purchased a feature you may store it as you proposed to do using NSUserDefaults, that will give you an ability to save app state between launches.
That is a most common and frequently used approach.


I2C receive handler, as seen on I2C for Arduino

Question: When managing smbus/I2C devices using python with the RPi, is there a way to register a handler function so it is called when a byte is available for read, like in Arduino Wire.onReceive()?
Otherwise, is the only way to do this to read periodically from the device (and handle the exception that is thrown if there is nothing to read)?
Thanks!
Answer: The Raspberry Pi I2C drivers only support master mode (i.e. the Pi initiates all I2C transactions).
There is no point in a Wire.onReceive method as the Pi does not accept unsolicited messages.
EDITED TO ADD
Some I2C devices have interrupt lines.  If your device does then this could be connected to a Pi gpio and could be used to trigger a Pi I2C transaction.
EDITED TO ADD
I thought the Raspberry Pi's I2C implementation was well documented. Apparently it isn't or I can't find it.
For I2C see http://en.wikipedia.org/wiki/I%C2%B2C
Do a search for raspberry pi acting in slave mode.  There are no implementations.
Answer: This is in C, and I'm not promising it will get you what you want (see joan's comments below), but it does meet this criteria:

is there a way to register a handler function so it is called when a byte is available for read

If you use the native i2c-dev, ioctl() based interface, you get a regular file descriptor.  You can then use regular old POSIX low levelread() and poll(), etc.   The later is useful in implementing call back functions.1
More information at:

https://www.kernel.org/doc/Documentation/i2c/dev-interface
https://www.kernel.org/doc/Documentation/i2c/smbus-protocol

You may want to go through other things in that directory (Documentation/i2c/) but that's the best place to start.  It's the same path as in a kernel source tarball, if you have one of those.
I've used the native userland interface via C and C++ quite a bit with a bunch of devices.  The only caveat I have is that some of them respond better to plain read() and write() than to the i2c_smbus_ functions; if at first you don't succeed try the same thing only different.

1. If you don't know how to implement a callback with poll(), it is a fairly common practice but you may need a separate thread.  If you just want to wait for other stuff at the same time and handle events as they happen, a single thread is ok; if you want to do unrelated things at the same time, that requires multiple threads.
Comment: Yes, you are quite right.  On the Arduino the [onReceive](http://arduino.cc/en/Reference/WireOnReceive) method is only used when a slave device receives a message from the master.  The Pi's have no provision to be a slave device (although the needed gpios are exposed on the A+/B+ I can't see anyone writing a driver).  As a side note it would be helpful if people mention the model of device they are using when asking for help.
Comment: For a byte to be available to read it must have been already read by the I2C driver during a Pi initiated I2C transaction.  I'm not sure what scenario exists where getting a callback after polling for data is particularly useful.
Comment: @joan The context you are implying (that this is not part of a transaction) is not clear in the question (perhaps it's packed into "Arduino Wire.onReceive()"?) -- in any case, I saw *"When managing smbus/I2C devices...is there a way to register a handler function so it is called when a byte is available for read?"* and the answer is yes.  As to whether that's a useful tactic because of the transactional nature of the interface I can't say -- you might be right.  I haven't found a need for it WRT I2C handles.
Comment: @joan Okay.  I'm unaware of the relevance of slave vs. master devices (the pi is my only i2c experience), so this would not have occurred to me!  Again, it would be great if you could add a few sentences to your answer to make this context a bit more explicit ;) I'd guess the OP lacks the terminology to explain/understand the question better himself.


allogeneic organ transplant and the immune response

Question: What happens when an allogeneic organ transplant is performed on an immunocompetent recipient vs. when it is performed on an immunosuppresed recipient using a donated organ with immunocompetent cells?
Comment: Is this a homework question?
Comment: No, it's a question I saw when reviewing organ transplant
Answer: The situation is just as you'd imagine. In an immunocompetant recipient, a host-versus-graft reaction occurs. This is called transplant rejection. Single episodes (acute rejection) are easy to treat and rarely lead to organ failure. Chronic rejection is the leading cause of organ transplant failure. The organ slowly loses its function and symptoms start to appear. This type of rejection cannot be effectively treated with immunosuppressants. Some people may need another transplant.[1]
In bone marrow and other transplants, T cells in the allografts reconstitute T-cell immunity in the recipient. Unfortunately, these T cells recognize the recipient as 'non-self' and employ a wide range of immune mechanisms to attack recipient tissues in a process known as graft-versus-host disease (GVHD).[2]

Acute GVHD describes a distinctive syndrome of dermatitis, hepatitis, and enteritis developing within 100 days after allogeneic hematopoietic-cell transplantation (HCT). Chronic GVHD describes a more diverse syndrome developing after day 100. In addition to allogeneic HCT, procedures associated with high risk of GVHD include transplantation of solid organs containing lymphoid tissue and transfusion of unirradiated blood products.[3]

GVHD is increasing due to the increasing number of allogeneic hematopoietic cell transplantations (HCT). More than 25,000 allogeneic transplantations performed annually. Given current trends, the number of transplants from unrelated donors is expected to double within the next five years, significantly increasing the population of patients with GVHD.[4] Yet the major complication, GVHD, remains lethal and limits the use of this important therapy.
Long-term immunosuppressants are usually the treatment regimen for chronic GVHD. Fungal, bacterial, and viral infections are a major risk with this treatment since the immune system will be suppressed for a very long time.[5]
[1] Transplant rejection
[2] Graft-versus-host disease
[3] Graft Versus Host Disease
[4] Graft-versus-Host Disease
[5] Graft vs Host Disease: An Overview in Bone Marrow Transplant


Configuring Postfix, Spamassassin and Procmail to put spam in a dedicated folder

Question: I'm not sure if SF is the good place for that, so sorry if it's not the case.
I'm administrating a Debian server for our company's emails and I'm trying to have the emails flagged as spam by Spamassassin to go in a dedicated folder for each user (like Spam/ or Junk/) but I can't manage to do it. I already have Postfix and SpamAssassin running well (SA flags the spam emails in the subject field properly), but now I must set a Procmail filter to put them where I want.
Here is what I have :
In my /etc/postfix/master.cf, I have a SA rule :
spamassassin unix -     n       n       -       -       pipe
    user=spamd argv=/usr/bin/spamc -f -e
    /usr/sbin/sendmail -oi -f ${sender} ${recipient}

I tried to add a rule for my spam filtering :
spamfilter    unix    -       n       n       -       -      pipe
  flags=Rq user=vmail argv=/usr/bin/procmail -Y -m /etc/postfix/procmail-spamassassin.rc

And my /etc/postfix/procmail-spamassassin.rc :
SHELL=/bin/sh
LOGFILE=/var/log/procmail.log
VERBOSE=yes
LOGABSTRACT=all

:0
* ^X-Spam-Level: \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
Junk

But it doesn't work and I can't understand why... I have no output in procmail.log so I can't figure how to debug that (my Postfix log doesn't give more). postfix reload seems to ignore my changes.
I tried many others configurations, like having a mailbox_command in my main.cf to use Procmail, and it isn't better... For information, we use Postfix virtual mailboxes (mailboxes are stored in MySQL, not mapped with Unix accounts).
I know Procmail can run this way cause I have a similar vacation filter in my master.cf and It works :
vacation   unix    -       n       n       -       10      pipe
  flags=Rq user=vacation argv=/usr/bin/procmail -Y -m /etc/postfix/procmail-global-repondeur.rc ${sender} ${recipient}

Can you see what I did wrong ?
Comment: Wild guess, wrong permissions for the `rc` file?
Answer: Why not just have the final mail destination be procmail? There's not need to set up a different transport. Look into the mailbox_command value in main.cf.
Answer: Did you add "spamfilter" in the "transport" table ?


Difference between automated and living labor pertaining to surplus value

Question: In the Marxist concept, animals, machines and slaves are incapable of producing surplus value. They only produce as much as they have to in order to function, and no more. Doesn't this also describe the condition of "wage-slaves"? I have heard that the difference is that the wage-slave sells his labor. But I fail to see how a machine that sells its labor for fuel and spare parts would suddenly be able to produce surplus value. Explain please.
Answer: This question is oddly phrased.
The main marxist thesis about profit is that firms can't profit from technology, but ultimately profit comes from exploitation of human labor, i.e. by extracting surplus value from workers.
In marxism, profit always comes from "living labor", in the sense that the price of a commodity both reflects the technology used to create it and also the human labor congealed in it. However,  a firm can't "pay less" machines because machines have fixed values while a living human being can be paid less than their value of their labor if the value of their labor exceeds the value the worker needs for subsistence (e.g. sufficient for their bills, calories, leisure etc).


How to have any popup in firefox open as a tab instead

Question: I used to have a custom about:config setting that made it so that any popup a page would generate was opened in a new tab instead.
With my new install, I can't remember the name of this setting. Can anyone help me out here?
Answer: It's browser.link.open_newwindow.restriction set to 0.
Answer: I can't tell you the name of the setting, but you mention having a "new install."  If you are trying to configure firefox on a new machine, or if you think you will have to do this in the future, I highly recommend this little java applet.  It is an absolute gem.  Forget importing bookmarks and any reconfiguration.  This program will take your entire firefox profile and convert to a format which it will later use to import to your new machine.
Hope it's at least a little help for the future if not right now! ;)
Comment: That is cool, but isn't really an answer.
Comment: Nifty little thing. I'll be sure to use it.


Difference between 反射(する) and 映る

Question: I've been reading some Murakami and came across 反射(する) and 映る。I've never given them much thought other than that they mean reflection but I was wondering if there's some subtle nuance that I'm not aware of.
Answer: Their uses are different, and they are not interchangeable.
映る is an intransitive verb that means "(for an image) to be reflected/projected (on a mirror/screen/wall/etc)". The subject must be a recognizable "image", and the mirror/screen-like object is marked with に. You can also say テレビに映る. The transitive equivalent is 映す.

顔が鏡に映る。
月が水面に映っている。
映像がスクリーンに映る。
わたしの町がテレビに映っている。

顔を鏡に映す。
映像をスクリーンに映す。

反射する is both transitive and intransitive. When used transitively, the subject is a mirror-like object, and the object is usually a light/radio/sound wave, and sometimes something abstract like "damage". There doesn't have to be an "image".

鏡が光を反射する。
鏡がレーザービームを反射する。
(as a game item description) この盾はダメージの20%を相手に反射する。

When 反射する is used intransitively, the subject is a light/sound/radio wave.

光が鏡に反射する。
月明かりが海に複雑に反射して幻想的な光景を作り出している。

Finally, 反射 can be used only for physical phenomenons. You have to use 反映 for a sentence like "the price reflects the demand". 反射/反映 does not mean "to think back deeply", either.
Answer: Not a native speaker, but since Korean has similar words (both the Sino-Korean word 反射-hada and a native word bichida similar to 映る), probably it is the same in Japanese. The following is same for Korean.
反射 is the literal action of reflecting something. It can be used for visuals, but is not limited to. For example, it can be used for sound, or even some abstract effects.  映る is an action of something is being reflected on some surface, so that the image can be seen by people. It is only used for visuals, unless it is used metaphorically.
And since 反射 is from Chinese, I think it is often more formal than the native words like 映る or bichida.

Difference between 反射(する) and 映る


How are Norse gods of Dark Horse comics related with Marvel comics?

Question: In The Mask franchise of Dark Horse comics, Asgardian mythologies are mentioned. In Son of the Mask (2005) movie, I have seen Loki, Odin & have listened about Thor.
How are they related with Odin, Loki & Thor of Marvel comics? Are they same or from different universe? If they are same, can you locate the events of Son of the Mask on timeline of Thor movie?
Comment: Why would you possibly think they're from the same universe?  If I write a novel in which [Abraham Lincoln](http://en.wikipedia.org/wiki/Abraham_Lincoln) is a reptilian alien, would you ask whether he's also a [vampire hunter](http://en.wikipedia.org/wiki/Abraham_Lincoln,_Vampire_Hunter_(novel\))?
Comment: @jwodder Yes, I can ask that if I am not familiar of whole canon because there's always a possibility that there's tie-in between the stories.. even if they are from different publishers.
Answer: They are not related at all. Consider them beings who share a name, perhaps some behaviors, or historical references but beyond that, each is a unique representation of the Norse mythos and its attendant deities. In recent decades, the Norse mythology has experienced a resurgence in modern media because:

Most people only have a passing knowledge of them. This helps them be mysterious and new to readers/viewers.
The history of the Norse gods is rich with diverse stories, powerful and often capricious entities, just right for storytelling. Odin, Loki and Thor are the most commonly used entities from the Norse mythos.
Odin, is a dark scholar, inscrutable, berserker, warrior, sage, shaman, trickster, he is just a veritable bag of tricks, as liable to kill you as help you. What fun he is to write about.
Loki, best known for being a trickster god, willing to do almost anything for his person aggrandizement or entertainment, a liar and a cheat, no trick is too low, and no victim too innocent for his taste.
Thor is the most well known member of the Norse mythos, with his signature hammer, he is iconic in all the best ways. Not always portrayed as the brightest light, but generally considered a good guy, except when he isn't. Be afraid when he isn't.

Almost every major comic group has a version of these characters, they are simply too rich and interesting to NOT write about.
Answer: The guy who wrote the mask pitched the idea with marvel first before running them on dark horse comics so assuming this it is indeed intended to be the same loki
Comment: Can you provide a source for your answer, it is very interesting.


square wave frequency representation

Question: New to this signals stuff and i'm confused about the frequency representation of the square wave. Correct me if i'm wrong, a periodic square wave is composed of odd harmonics sine waves which are multiples of the fundamental frequency, In the frequency domain this just represents decreasing impulses at every odd multiple of the fundamental frequency . What relation does the sinc function have with the square wave? and which is the correct spectral representation of the square wave? Thanks!
Answer: The transform of a single rectangular pulse is a Sinc function.  Each added translation of that pulse adds a twisted repitition of that Sinc.  The twist will equal 2 pi at all spectral distances that are odd integer multiples of the reciprocal of the repeat period.  Repeat, and eventually all the twisted portions will all cancel out (form circles in the complex plane around zero) except at those points representing the odd harmonics.  Thus an infinite repeating square wave will be left with only non-zero spectrum at odd harmonics in its transform.

square wave frequency representation


Is there a way to fixate the diopter adjust knob on Canon DSLR?

Question: Sometimes, without noticing, probably when pulling the camera out of the bag or inserting it, the diopter knob turns by accident and gets the viewfinder out of focus, and ruins by that the manual focusing for me. Is there a way to permanently disable/fixate the diopter knob on pre-set value? Or it has to be a habit of checking the knob position every time I start shooting?
Thanks.
Answer: I just started having this problem when putting my camera in and out of a Aquatech rain covering. I have a Canon R-5, so they do not make an eye-piece for it. I had to take the stretchy hole where the eyepiece goes and stretch it around the existing eye-piece. When doing that, the diopter moves. I decided to try the tape method. I used a duct tape that is not extremely sticky, and cut it to fit. Another idea would be to put a tiny dot of colored nail polish on the correct setting, so it would be easy to line up if it moves.
Answer: Can you put a small piece of gaffer's tape over it? Should be easy to cleanly remove when you want to. For some controls I've used a dab of hot glue, sometimes with a piece of teflon tape covering the knob surface itself. If you build up some glue against the teflon tape, then remove the tape, you can sometimes create a "semi-protected" state where it can still be actuated if you need to, but doesn't happen accidentally.
Comment: The gaffer tape is a pretty nice hack and I think it will work fine.
https://www.flickr.com/gp/alexbabi/R54E0m
Comment: @alechko It's a good look, welcome to the junkyard club! If the tape seems to get messed up by the inside of the bag, cutting the corners off can help, as well as keeping the edges in low-profile areas generally.
Comment: thanks, it was just a test, I've already re-applied the tape, I did better cuts and cleaned the camera area with a bit of alcohol to make it stick better. works great.
Answer: You could remove it altogether.

Set the diopter wheel at the adjustment you desire.
While holding the adjustment wheel to prevent moving it use a (correct size & type) screwdriver to remove the screw in the center of the wheel.
Lift the wheel straight out of the housing.
Replace the screw to close up the opening.

If you don't want to do anything that drastic and you don't currently have an eyecup attached to the viewfinder get one and place it on the camera. It will partially protect the diopter adjustment wheel from inadvertent movements. Check your User's manual to see which size your particular camera uses. Most Canon EOS DSLRs use either the Eb, Ef, or Eg size and are relatively cheap. You can get third party substitutes at very low cost. Some of the knock-offs have been reported to be larger than the OEM part and completely block the diopter adjustment wheel.
Comment: I tried to remove the diopter knob, but there's a pretty huge empty space left after removing it, there's no way I would return the screw back because it sticks out and it might bend or something when using the camera, I'd rather fill it with half of foam ear plug or something similar, I would not want that empty space to be left exposed.
I do use the original eye cup, I believe it the Eb model.
Answer:
Is there a way to permanently disable/fixate the diopter knob on pre-set value?

I doubt it. The knob seems to be mechanical, and there's nothing like a "locked" setting. I don't think you'd want to remove it entirely because you'd have no way to fix it if it ever went out of adjustment, or if your eyes change. Perhaps the best solution is to arrange your camera bag so that the camera isn't jammed in there too tightly, or change the orientation of the camera in the bag. I've had the same problem you describe, but only when the back of the camera rubs against the wall of the bag. It's never an issue in a messenger-style bag where the camera goes in with the back facing up.

Or it has to be a habit of checking the knob position every time I start shooting?

It's a very quick thing to check -- when you look through the viewfinder, just try to notice if the displayed data (shutter speed, aperture, etc) is sharp or not.
Comment: I have 2 bags, one is snug fit, one is loose fit, it happens to me with both bags, so not sure if changing bag would help me much. I guess I could have another habit of something to check every time, but I was hoping there would be a way to lock it, and if I ever needed to unlock it. I do think the gaffer tape hack suggested by @junkyardsparkle could help me do that.


Does seasoned cast iron still need to be oven dried?

Question: I have a new, twice-seasoned (to 250C), (non-enameled) cast iron pan. Does the seasoning/coating remove the need to have it oven dried at the end of the day? Or it still has to be done no matter the seasoning?
Answer: Any exposed, non-coated part of a cast iron pan will be subject to rusting. Oven drying drives off the water before the reaction can happen to a noticeable amount.
The seemingly smart alec, but actually serious answer is: try to not oven dry it. If it does not generate rust, then it is seasoned enough. If it rusts, then rub again with light oil and oven dry. I tend to lightly wipe all over my cast iron a bunch of times until I get the entire pan nicely seasoned.
Comment: @MarsJarsGuitars-nChars point about rust is important.  Check your pan if you have not used it for a while.
Answer: If you use it every day or so, then no.  There is no need to oven dry your cast iron pans once they have developed that dark coat.  But after rinsing them you need to dry them promptly with a paper towel.  Give them a barely-there coat of oil before storing.  Soap is not recommended. The New York Times had an article on how to take care of your cast iron pan.
If your pan is new, the seasoning may not be complete. You will know you have a well seasoned pan when you can fry an egg on low heat and not have it stick.  Until it is well seasoned, avoid cooking acid ingredients.
To season the pan use unsaturated fats (a vegetable oil like canola oil); they react with the iron better than the animal fats some instructions recommend.  Because a seasoning pan smokes, I suggest doing it in the barbecue.  Let it "cook" for 30 minutes with the temperature at 450˚F.  Let it cool before handling.


Batch test RAW NEF File or command line utility?

Question: I need to test all my raw NEF files to see if any are corrupt. Had a hard drive issue, and while a few folders seem fine, I found one with a number of corrupt raw files. Need to scan my entire catalog to see what is affected.
Comment: As expected (unfortunately). That's why a (command-line) program which 'automatically' detects corrupt files cannot exist because, as I said, **the file** (the header and 'tile' boundaries/structure) can be ok, but **the image** can be damaged because NTFS/ext4/etc. blocks are much smaller that a 'a data tile' in TIFF on which NEF (and almost any Raw format) is based, hence in most cases *the file* is not 'corrupted' but *the data* can have bad (FFFF00FFFF00...) areas/blocks. That's why I gave more stages in detecting the corruption, included the quick visual inspection. To be continued...
Comment: What do you mean by 'corrupt'? You cannot load them at all? Or the files are shown but with wrong colors/patterns etc.? Can you upload a sample somewhere?
Comment: Corrupt -- can't open in Photoshop or Lightroom, I have pink bands across the bottom of the image.
Comment: Aha! Common effect of one (or more) bad sectors. Oh well... Or, to be more precise: You CAN open in Photoshop BUT it has those pink bands on the bottom of the image. (this means that the file structure/header is intact, just data is damaged). I'll update my answer.
Comment: Thanks I will try this at home tonight and accept if all goes well. Cheers
Comment: I am able to convert the files without getting errors, but when I look at the JPGs that are created, they have pink,green,yellow banding across the bottom halves or thirds of the image. But XnViewMP is not showing any errors while reading..
Answer: Ok - because if you didn't answer to my comment I try to give you a general, cross-platform solution.
Download XnView MP for the platform you need (it supports Win, MacOSX and Linux in 32/64bit).

With the Explorer find how many files are in your archive (right-click, Properties etc.)
Go with the browser of XnView MP in the root of your photo archive, being it D:\ , X:\Photos etc.
Select the folders by using

Shift-click in order to select a range ...and/or...
Ctrl-Click in order to select separate folders one by one.  ...or...
Press Ctrl+A (or Edit | Select All...) to select all folders

Now you have selected the folders which you want to check.
Go to Tools | Batch Convert (or press Ctrl+U) (...if you have many files you need to wait a little)
In the Batch Convert dialog which appears go to first tab called 'Input'. You should see something like this:

As you see in the name of the tab is written the number of files ready for the Batch Convert.
First Check: Are all the files present in there?
If not, select fewer folders (half of them) and repeat the steps from 0.
Second Check: Are all thumbnails correctly displayed?
If yes, then the NEF files have the embedded thumbnail/preview ok (hence you can recover something) but this does NOT mean that the RAW data is intact. Hence a simple import in Lightroom/Darktable isn't enough because these programs extract the embedded preview from RAW file.
Now go to Settings tab. There press the Load format settings button and for Camera RAW choose in the "Use" drop-down the 'Full Size' value. We want now to test the integrity of the actual RAW file.
Here is a checkbox saying 'Ignore read errors'. Experiment the next steps with this checkbox disabled and after that, enabled.
Go to Output tab. You should see something like this:

In the Folder field enter a folder path of your choice (be sure to have enough space, if needed!).
EDITED: DO THIS VARIANT: In the Filename leave it as is if you want to see all the raw files converted. This is useful to see if perhaps the NEF file structure is intact but is was altered only one or two blocks inside of it (changed colors, random colored blocks etc.). However doing like this, it will take you disk space to store the output files.
EDITED: THIS VARIANT IS NOT NEEDED: But if you're interested just to see if the NEF files reads correctly then in Filename field write a static text like 'temp' and in the Options pane choose 'Replace' for the 'When output files already exist' drop-down.
EDITED: THIS IS NEEDED: Also in the Options pane, if you check the Keep folder structure check-box, the entire tree structure of your photo archive will be duplicated at destination. Pretty useful if you intend to keep the destination and/or replace the corrupted NEFs.
In the Format pane choose an easy-to-view-and-small file format (usually JPEG) with medium resolution (click 'Settings') but you're free to choose anything else if you want to save disk space and/or time (WebP, JPGXR etc).

Run the Batch by pressing the Convert button. This can be done overnight. Anyway, the Batch engine will tell you in how much time will be ready and, generally, will present you the status of happenings.
At the end you'll see the log:

Have a loot at it to see where are the errors by scrolling / maximizing the window. Alternatively you can copy the log to a word processing program (Notepad/MSWord etc.) to do a Find/Search for 'error' etc.:

Right click and choose Select All (or press Ctrl+A)
Right click and choose Copy (or press Ctrl+C)

And now paste it in your text processing program of your choice and analyze it.
All the above is much more straightforward and simple than it sounds.
EDITED: ADDED: With XnView MP browser go to your destination folder (in my example c:\output\temp) and in the Folders Tree Pane right-click on the folder and choose (if your number of files vs computer memory permits) Show all files (recursive):

This will present you a flattered view of all your subfolders from your temp directory and you can inspect the saved files with ease. Also, if you have two monitors you can put the Preview/FullScreen pane on the 2nd monitor (see Tools | Settings for this).
EDIT 2: If the file structure is ok but the Raw data is damaged, then you have the following options:

Extract the embedded previews which on most modern cameras are 100% Full Quality JPEGs of the actual Raw data (ok, sometimes the previews are a bit 'doctored' by the camera). How to do it: In Batch Convert dialog, go to Settings tab and press Load Format settings button. In Camera Raw tab choose for the 'Use' drop-down the 'Embedded Preview' value. Save the setting and re-run the batch on the files in another destination folder. Perhaps you will use a loseless format like PNG. Now you have two folders: one with the actual raw data and one with the embedded previews from which you can choose the best (least corrupted) image (NOT file - all the files are ok).
Move/Delete/Rename the 'hopeless' NEFs. Go with XnView MP to the corrupted files. Tag them. There is a tag box in the top-left corner, or much better, press 'T' key to tag/untag the selected files. Be sure that in Tools | Settings | Browser | Tag the value for Tag filelist must be cleared has the 'Never' value. Alternatively, you can change the shortcut from Tools | Settings | Interface | Shortcuts. When all your files are tagged, you can go to Filter Pane in the top-left corner of the browser (in the default layout) and choose from there 'Special Items\Tag'. Now you see only the tagged files. You can Select All (Ctrl+A) and Move them (Edit | Move to...) and/or Rename Them (Tools | Batch Rename...) - eg. to append at the end a "_corrupted", and/or delete them. It is up to you.

...boy, I wrote an entire novel here... :) But it is your data and it is pity to lose it.
Comment: Some info added based on your response at my comment at your question. If you find that this is the solution at your problem don't forget to accept it. :)
Comment: Some more info added - how to try to extract all the valid data (because usually the files are ok, just the image data is corrupted) and how to manage the files which contain the corrupted images.
Comment: Wow..great ideas, thanks again. marked as best by a long shot.
Answer: I had face the same problem few times.
My approach was, importing the root folder containing all the sub-folders and RAW files into my RAW processing software(Lightroom/Darktable). Corrupted files appears with a special 'broken' thumbnail.
Comment: This approach, even if it can find problems, isn't bulletproof because usually these program use the 100% embedded JPG preview which resides in the RAW file. Hence, the thumbnail can be ok while the actual Raw data is damaged.
Answer: Before you try messing with the programs below, make a backup of your pictures!!!
You could use

ufraw-batch --out-type=jpeg *.NEF

to create JPEG versions, and quickly review those. (Man page can be found here.)
Alternatively, you could try using exiftool for data manipulation or dumping values and verifying the data you suspect to be damaged. (Man page can be found here.)
E.g.

exiftool -b -JpgFromRaw image.NEF > image.jpg

Both run on Linux, but you can use them in Cygwin or MinGW on Windows.
If some more elaborate finding is needed:

find -iname "filename_with_wildcard*.NEF" -print0 | xargs -0 -I {} exiftool ...

... meaning your command parameters, where you put {} instead of the actual file name. E.g.

find -iname "Cats*.NEF" -print0 | xargs -0 -I {} exiftool  -b -JpgFromRaw {} > {}.jpg

(A bit ugly, because it will emit Cats1.NEF.jpg files, but let's keep to the simple example instead of beautifying shell commands...)
Comment: ufraw-batch is poor in options for this case IMHO. For example, the folders must be done one by one and the output text from console must saved in a file by using redirecting / pipes etc. Also, command line is a little bit scary for a common photographer. (Btw, I should down-vote you for that 'Cats*.NEF' but Linux saved the day :) - FYI, exiftool exists also on Win)
Comment: I'm not afraid of command line, I have experience with Linux. If I wanted to review individual files, I could just review each RAW file. I want an automated option that spits out a list of corrupt files. If there's a command line program that can verify whether a RAW file is valid or not that would be ideal.


How can I find out whether I am permitted to re-use an online questionnaire in my own research?

Question: So, I get this page's link: User Interface Usability Evaluation with Web-Based Questionnaires from my friend. I want to make one of them as Questionnaire for the design I made for Academic Research. But I'm confused, is that only an example, a guideline, or can I use the Questionnaire as it is? Is there any license for those questionnaire? I've tried to read the page, but don't really know if there's something like that.
Answer: The script doesn't seem to have a license but says, "question.cgi is a free script for administering user interface usability questionnaires on the web." In other places on the page you linked to, the authors encourage reuse. If you are unsure or unclear, you can contact the authors.
Answer: Actually, the text on the page is pretty clear:

The script is freely available, AS-IS

So, yes, you can use it as it is.
Combine this with the (slightly) earlier text

allows the online reader to design and create their own questionnaire

and I think there is only one way to interpret this as "Feel free to use this!"
Comment: I thought that statement only applied to the script, or source code, for showing those questionnaire. Like, maybe you want to make an online questionnaire, then you can use that script to show your questionnaire in your web. Hmmm or is the freely use of the script also meant the freely use of the questionnaire 's contents too? Does the script also include the questionnaire's contents too?


Is ASP.Net a technology suitable for high-load sites?

Question: That's the question... Do you think ASP.Net is a technology suitable for high-load sites? Do you know any populer sites -apart from stackoverflow, of course- built with this technology?
Thanks.
Answer: MySpace, Orkut, ASP.NET Forums, Microsoft.com, ...
ASP.NET has great caching and load balancing features that make it suitable for high load Web sites.
It's also a very flexible, well-designed framework. If you don't like part of it, or think its performance intensive for your high load application, you can just throw out that layer and replace it with your own. If you don't like WebControls and Pages due to its overhead, you are able to write your own HttpHandlers.
Basically, I think ASP.NET MVC is going to be a better platform for high load and customized Web sites, since it can be more hand tuned (relative to ASP.NET pages that try to abstract away the resulting HTML, for good reasons) and works better with AJAX applications. WebControls and ViewState are two parts that usually face criticism that are pretty much gone away in MVC.
Answer: ASP.NET gets a bad rap in the "Web 2.0" world. MySpace has 50 million+ users and I'd call that "high load."
I think that, like just about any other web technology, the capability of the tool lies in the hands of the developer creating for it. If ASP.NET developers ignore caching and load balancing, the app won't handle load, and it won't be ASP.NET's fault.
Answer: monster.com, newegg, most news sites, and many more!
Comment: "most new sites" - based on what? Please indicate source of this information.
Comment: missed the best one stackoverflow!
Answer: As well as the above answers, The Code Project is an ASP.NET site.
Answer: The answer is "yes and maybe".  Can it handle it?  Most definitely.  ASP.NET has a lot of features.  With a lot of features, there is a lot that can be done poorly in a site.  A large-volume site needs careful design consideration and planning to make sure that it is both horizontally and vertically scalable.  Chances are, if you just shoot from the hip and are doing any actual processing on the server-side, you will eventually end up in a world of hurt.
We love the .NET Framework, and are thrilled with the flexibility and power of it - ASP.NET, whether backed by C# or VB.NET is a stable and feature-rich platform.  For more of the nuts and bolts around performance concerns, I strongly recommend Microsoft's Improving .NET Application Performance and Scalability.  You can additionally download a completely free ebook of the content, as well.
Answer: ASP.NET is definitely a good platform for high load sites, but keep a wary eye on those "Ajax" extensions. They pretend to do partial page postbacks but they have all the load of a full page postback.
Answer: When people ask if ASP.NET sites can handle large traffic, I often refer them to plentyoffish.com. The site has massive traffic and runs on a handful of servers. It's famous for having operated for years on two servers --- one to serve up images and one to handle everything else.


layout customisation in magento

Question: I have set my homepage layout to 2 columns with right sidebar what i want to do is, I want to put a block just above the footer of my homepage in such a way that it will cover full width of the page. Currently, I can't achieve that because my homepage is 2 columns with right sidebar, so it obviously leaves space at right part. Is there any way I can define block in my homepage which will cover full width? or any link which is helpful to proceed?
Answer: Just follow my answer on this recent thread.
Basically you need to create a structural block that should come just below the content section, but just above the footer section. This way structural block will appear after the content section, which is in 2 column right bar section.
Please note, instead of 2-column-left.phtml that I have used in that answer, you need to call the structural block inside 2-column-right.phtml.
Hope that helps
Edit
It seems that the provided link is not working now. So I am now responsible to add a full solution here. Thanks for my friend @DavidManners to notify me. :-)
Basically we need to add a structural block in between content section and footer section. For this create a local.xml file and add this layout update.
File : app/design/frotend/<package>/<theme>/layout/local.xml
<layout>
    <default>
        <reference name="root">
             <block type="core/text_list" name="block.after.content" as="after_content" translate="label">
                Sub Content Area
            </block>
        </reference>
    </default>
</layout>

By putting this content, we just added a new structural block inside root block. Here root block is what page layout block.  It determines which layout a page holds. So the template file corresponding to root block vary depend upon the layout we need. Suppose if we need a 2 column right layout, then what we need to do is set the correpsponding template to this block. It would be done like this.
   <reference name="root">
        <action method="setTemplate"><template>page/2columns-right.phtml</template></action>
    </reference>

Now I assume your page is 2 column right layout, then in that case, you need to add this content by manually editing the file.
File : app/design/frontend/<package>/<theme>/template/page/2columns-right.phtml

            <?php echo $this->getChildHtml('breadcrumbs') ?>

                <?php echo $this->getChildHtml('global_messages') ?>
                <?php echo $this->getChildHtml('content') ?>

<?php echo $this->getChildHtml('right') ?>

<?php echo $this->getChildHtml('after_content') ?>

Here we are calling our block after_content manually. The position at which the block is calling is very important here. It should be in between the (content, right) blocks and footer block. This way our block will get a full-page-width access.
However the manual addition I have shown above should do in a custom theme. Dont do this in base/default theme. Always use a package theme other than base/default for better extendability. Additionally, if you need to include this block in every page layout, then you need to repeat the second operation in every other page layout template files. ie phtml files that comes inside app/design/frontend/<package>/<theme>/template/page/ directory.
Comment: the link seems to 404 :(
Comment: @DavidManners : oops. I think the questioner deleted that question. So you want to see the solution?
Comment: Yeah think so. Would be great to have the full solution here.
Comment: I will do it now. Give me five min
Comment: @DavidManners : Answer updated. I have recollected my memory as possible I can. Have a look.

layout customisation in magento


Logo design company recommendations

Question: I've been looking at some logo design companies, but have no idea if they are considered reputable or not.
They cost around 250-300$. I would name them, but I'm not sure if that goes against the forum rules or not.
Comment: Hi Eugenia, thanks for your question. What advice exactly are you looking for? Nobody can tell you if a company is reputable or not without knowing who they are. What I can say is that $250 is cheap for a logo, but it's unclear exactly what you are looking for. If you have any questions, please see the [help] or ping one of us in the [chat] once your reputation is sufficient (20). Keep contributing and enjoy the site!
Answer: Good logos can cost anywhere from $5 to $500,000 and probably more. The price does not necessarily equate to the quality of the finished logo (look at the 2012 London Olympics logo!).
Also, someone who has designed a great logo for a banking company might not be able to design a great logo for a community gardening organisation.
You need to approach the company and ask to see their portfolio (as with employing any design service). Ask them to talk you through their examples as case studies; get them to explain their working process and their rationale for making particular design choices.
The idea is to see if their approach to design fits with your business goals.
Answer: It really depends on what you want out of a logo. If you just want a nice graphic then many sources might be good. However there is more to consider when buying a logo.
In the end, a good Logo designer often needs to interview you and access your workers. Likewise, you as a company often need the logo designer to explain logo rationale and usage scenarios. Also, a logo quite often would mean changing the whole look and feel of the company collateral.
That process in general costs more then $300 in most locales, in just lost productivity of meetings, but not all companies are born equal.
Answer: To determine if these companies are reputable, I would suggest asking them for Case Studies and Client Testimonials. Ask if you can speak to any of their past clients for a reference.

Logo design company recommendations


approximately how much compost does a foot of wood chips compost down to?

Question: I'm heavily composting my garden with arborist wood chips, and was wondering how much compost I get from a square foot of wood chips. I'm using Stropharia Rugosoannulata to break down the wood chips.
Answer: I would say the amount of "compost" you will get is precisely zero.
Saprophytes such as Stropharia Rugosoannulata feed by breaking dead organic matter down into simple chemical compounds such as its constituent amino acids and sugars (for example the cellulose in the wood chips is converted into glucose). Those products are not "compost" by any reasonable definition of the word, and they are mostly soluble in water so they won't leave any permanent residue.
When it runs out of wood chips to feed on, the Stropharia will cannibalize itself as it dies of starvation.
Comment: i'm trying to raise the ground in an area for the garden, and I've heard that it attaches itself to nearby roots when it runs out of food. am I wrong with these ideas with worms moving in?


How can I fix a leaking sprinkler valve?

Question: My sprinkler valve leaks water as soon it shuts off. By checking online and going to Home Depot first I installed new inside parts, that didn't solve the problem. then I was told that I had to replace the whole valve, so I did and it's still doing the same thing. Anybody know what's going on or how to fix it?
Comment: Forgot to said that water comes out of the vacuum breaker even on the new valve.
Answer: The most likely issue going on here is that the sprinkler piping down stream from the valve is at the same elevation or higher elevation than the valve itself. Water left in the line is flowing back through the anti siphon air gap in the valve and resulting in what you see as a "leak".
Normally sprinkler valves are meant to be installed so that they are eight to twelve inches above the highest elevation of the watering circuit to prevent this problem.


Sweet pickles for home canning

Question: I want to substitute some natural cane sugar for white sugar, because I don't have enough of the white to make pickle recipe. The recipe calls for 7 cups of sugar, and I have 4 1/2 of refined white sugar so I want to use the rest in natural cane sugar. Will this work?
Answer: Yes, you should be fine with a mixture of sugars as it is mostly for flavoring. The main point is to make sure the sweetener is fully dissolved in your pickling liquid.
One user asked a similar question about using honey, and searching the web also produced recipes for how to use sugar substitutes in place of sugar for pickling.
Comment: thank you, wasn't sure, will know for next time, I have done so many pickles this yr. probably close to 100 jars of all kinds, and my cukes keep coming faster than I can process, I ran to store and got the white, that is the only time I use refined sugar, so didn't want to mess up my recipe for lack of trip to store
Comment: I haven't been canning or pickling for too long, so treat this accordingly, but I routinely use natural sugars as a substitute for the pure-white refined stuff and have seen no adverse effects whatsoever. If anything I think it tastes better.

Sweet pickles for home canning


Why did this flight never depart ? West Jet 1:00 pm on 2/01/19 from Toronto to Montreal

Question: Why has West Jet flight bound for Montreal from Toronto on February 1 2019 at 1:00 pm never departed.
Comment: Why does it matter?
Comment: If it didn't depart, it must have been canceled. That happens, for a variety of reasons that airlines typically don't bother to make public on a flight-by-flight basis.
Answer: This flight was cancelled.
Over the past few days, thousands and thousands of flights have been canceled across North American, especially in the area around Toronto, due to storms and temperatures reaching well below freezing.
These conditions have affected everything from the ability to  takeoff and land, as well as to prepare the aircraft.  For example, in Chicago they were unable to fuel planes due to the fuel pipes freezing shut!
This same flight was also canceled the day before as well, as were hundreds of other flights into and out of Toronto over the past few days.
Comment: Not sure if "uncontrollable" is an aviation term for very bad weather but the reason for the cancellation is indeed given as `1FX CXL WX UNCONTROLLABLE IN YYZ  *1815*HDQOCA` on the GDS
Comment: "CXL WX" means that the flight was canceled (CXL) due to weather (WX).


Is there any other platform to check contract working?

Question: I am trying from past few days but didn't get test ether to test my own contract...is there any other platform where I can test my contract or can you send me some ether
<code>0x0aB6F803A232a9cd595efB9eaf496415Bb7E52e8
</code>
Comment: Test it in a private network
Comment: How to do that ??
Answer: You can download testRCP (repo https://github.com/ethereumjs/testrpc) and run a local node on your PC, then set up Remix to run on your local node.
Setting remix:

On 'Contract' - 'Environment' choose Web3Provider and then set http://127.0.0.1:8545 (http://localhost:8545 won't work)

Once you deployed your contract on your local node just go to MEW (MyEtherWallet) https://www.myetherwallet.com/ and on the top-right you can choose which node MEW should connect to.
Define your own custom node:

Set up the node:

N.B: testRPC must be running on your PC or this won't work.
Now if all went well the account displayed in your testRPC console should be accessible, with the private key, through MEW.

Hope it helps. Come back if you have doubts.
Check this for more info: https://myetherwallet.groovehq.com/knowledge_base/topics/how-can-i-connect-to-a-custom-node
Answer: Remix is an online solidity compiler which lets you deploy contract online and there is another online solidity IDE youn can use that too.


Will soaking chicken in milk hurt the chicken

Question: I'm trying a new recipe and I was told to soak my boneless skinless chicken thighs in milk with a little spices. Let them soak for a while then take them out of the milk and then drop them in seasoned bread crumbs. Cook for about 20 minutes with foil on and another 10 without foil. It sounded good so I am going to try it. Does this sound like it should work?
Comment: It won't hurt the chicken, because the chicken is dead. (SCNR.)
Comment: It's hard to say whether it will work without knowing what "work" means. What's the expected benefit?
Comment: It won't "hurt" it in any way I can think of, so go ahead and try. I like chicken baked in a "breading" from yogurt and ground spices, but haven't run across other dairy-based marinades personally.
Comment: Hurt? Studies show that mixing meat with milk degrades digestive absorption of milk calcium due to abundance of iron in meat. It hurts the milk not the chicken.
Answer: Soaking chicken in milk or buttermilk in the refrigerator overnight is a common practice when making Southern-style fried chicken.  This practice supposedly tenderizes the chicken through the actions of enzymes naturally present in the milk.  Yoghurt is used in a similar way in many Middle Eastern and southern Asian food ways.
The milk can be used alone, but is often seasoned with onions, garlic, or spices.
Answer: I can hear one lone salmonella on a piece of chicken shouting "yipee!" as the chicken lands in the milk marinade, which is pretty clever for something unicellular that doesn't have lungs.
There has to be more control than "a little while" in the milk.
Off the top of my head, I'd suggest no more than a half hour in milk, and then the dunk in breadcrumbs and cooking has to happen in the next few minutes.  If the overnight immersion is wanted, do that in the refrigerator so the temperature does not get over 4 degC .
I don't see anything bad about the procedure, and it might make a big difference to the final dish - but there is not a lot of point in making Southern fried bugs as a by-product.
Comment: I've made numerous recipes that called for overnight soaks in milk or milk products (eg: yoghurt). Is there any reason salmonella rate of production would increase when the chicken is combined with milk? Obviously, this would be done in fridge, covered well, etc... as with ANY chicken marinade.
Comment: Yes, but even if you change the original question to "if I soak my chicken in milk IN THE FRIDGE... will ... ?", which I assume they would do, now knowing the inherent dangers, they're still right where they started not knowing the answer to their question, which is the point of providing "answers".
Comment: The part about milk accelerating growth of salmonella is really good information, but your answer didn't really explain that. I think this disclaimer would be a helpful comment, and that is really good to know. I'll be sure to be even more carefull with such marinades. As it stands though, I think this makes a better comment then a full answer, as it doesn't answer the OPs question of "will this work".
Comment: @talon8 - the whole purpose of the post is to remind people to use the fridge. Salmonella production will increase when the chicken is covered with milk, they are facultative anaerobes, so they like to be covered by the milk and use the small amount of oxygen dissolved in the milk for growth. Chilling stops them growing.
Comment: LOL - the answer is that it will not work, unless care is taken to avoid "laxative bugs", although it has to be said that chicken producers are conscious of the need for care these days. Didn't want to put the OP off the dish.  If you want belt and braces safety, or room temperature marinading, you can quickly sear all the meat surfaces, then score the surfaces lightly to let the marinade penetrate the meat. How easy that is to do depends on how cleanly the meat was cut.


Legality of using album artwork from freecovers.net

Question: I am building an online store for a vinyl company and I want to create an application to help them add cover artwork to their store. Am I legally allowed to use the artwork from freecovers.net on their online store? Will I get sued?
Answer: Am I legally allowed to use the artwork from freecovers.net on their online store?
Maybe.
Will I get sued?
Maybe.
I had a look at their site and when trying to follow the link to the "Terms of Use" page all I got was a broken database query so I can't see whet they say about it. However, reading their FAQ and the way they source their covers there is a very real chance that there are potential copyright breaches involved.
Put simply, the covers are somebody's copyright. In general, they have been uploaded without the copyright holder's permission. The use that FreeCovers.net makes of them may meet fair use/fair dealing provisions in the copyright acts of the relevant jurisdictions (i.e. basically every jurisdiction in the world for online use) or they may not - that is between the copyright holder and FreeCovers.net. It is likely that they would in the USA; in places like the UK or Australia it is likely that they wouldn't - what is fair use/fair dealing depends on jurisdiction.
What you are proposing to do (use the covers in a profit making venture) is extremely unlikely to be considered fair use/fair dealing anywhere and may leave you open to being sued by the copyright holder - whether that suit is successful is a matter for the court.
However, if you are selling the records then it is highly likely that the copyright holder of the music and the cover art are the same organisation i.e. the record company. If you approached them for permission to use the cover art and they agree, then you are home and hosed.
Comment: Good answer, but don't you Aussies know that "[hosed](http://english.stackexchange.com/q/35972/67775)" means pretty much the opposite in the U.S. (at least)?
Comment: I can't be held responsible for the way you Americans break a perfectly good language
Comment: TIL - "home and hosed" = home free


Matching in Blanchard-Diamond (1994)

Question: Setup Blanchard-Diamond (1994) have a model where each unemployed has a single ball (application) that she tosses into urns (vacancies). With probability $a$ the application lands in the urn - the unemployed manages to fill out the form, and his application is "valid".
Vacancies are open for a fixed period and then evaluate their application pool, leading to multiple applications per vacancy. Under some conditions, the distribution of applications per vacancy (denoted as $g(x)$) will be Poisson with expected value $au/v$.
Firm-based job-finding rate The number of matches is hence given by the measure of vacancies that have at least one application, times the number of vacancies
$$M = (1-g(0))v$$
and the job-finding rate is given by
$$ M/u = (1-g(0))v/u$$
Unemployed-based job-finding rate Instead of looking at the firms, one can look at the unemployed. As firms randomly draw from the pool of applicants, the average chance of an unemployed matching is the probability of matching times the inverse of the number of contestants that he will face:
$$ f = a\frac{1}{E[x | x > 0]} \\
= a\frac{1}{\frac{E[x]}{1-g(0)}}\\
= a\frac{1-g(0)}{au/v}\\
= (1-g(0))v/u$$
Which is turns out to be the same job-finding rate as calculated from the firm's perspective. This makes sense, as it needs to be an identity.
Firm-state-based job-finding rate Finally, to the part where I am struggling: An alternative way of computing this job-finding rate should be
$$ \tilde f = a \sum_{x=1}^\infty Prob(\text{applicant matches with firm with $x$ many applications} | \text{ she matched}) \frac{1}{x}$$
Which basically has the same logic, but is more detailed. This is interesting when one wants to analyze the $x$-component to the job-finding rate (i.e.: How relevant are firms with 5 applicants to the job-finding rate). However, the probability appears to be complicated. How do I compute this job-finding rate?
Answer: The total number of matched applications is
$$\sum_{x=1}^\infty g(x)xv = E[x]v$$
The number of applications matched with vacancies with $x$-many applications is
$$g(x)xv$$
Hence
$$Prob(\text{matching with x} | \text{matched} = \frac{g(x)x}{E[x]}$$
Using this in the equation in the question gives
$$ \tilde f = a \sum_{x=1}^\infty \frac{g(x)x}{E[x]}\frac{1}{x}\\
= E[x]a \sum_{x=1}^\infty g(x) \\
= \frac{v}{u} (1-g(0)) = f $$

Matching in Blanchard-Diamond (1994)


Using all votes in Elections

Question: I didn't see anywhere that it specifies whether or not we have to use all of our votes in elections. I know that process for determining winners is STV, under which it is possible to include voters who didn't use all of their votes, but I just wanted to verify that my votes would still be used.
Comment: +1, I was wondering about it as well.
Comment: I agree that this should be stated directly. However notice that using three votes results getting a badge, so it is a tough decision to make (just joking).
Comment: Haha, you can always wait for another election where there are 3 candidates you are actually interested in winning.
Comment: See also [this](http://meta.stackoverflow.com/questions/290805/is-it-okay-to-vote-for-just-two-candidates) in relation to the currect SO election.
Answer: Yes, your votes will still be used.  You may cast just one or just two out of the three you are allowed.
I base this conclusion on having analyzed (in detail) the results of some other elections.  A close look at some of those data summaries and visualizations will show that some voters cast incomplete ballots but their votes contributed to the results.
Comment: excellent snooping whuber
Comment: +1 I've also looked at the votes in previous elections; it's definitely the case that users can vote for fewer than 3 candidates and still have their votes count. I've also just participated in a real-world election that uses a similar system... but has vastly more candidates. It used to be the case in the real-world one that you had to order the entire field of candidates -- well over a hundred of them (but nowadays, fortunately, the requirement is reduced to a smaller number). [Well, there was a shortcut that involved only indicating one thing, but it involved a compromise I could not bear.]
Answer: Just to confirm -- votes that had only one first choice, or only a first and second choice were present in the election that was held ... and were used in the way you would hope.
Here's a little piece out of the (publicly available) data file, with spaces added, some column headings not present in the original (for context) and some added comments:
num   1st    2nd  3rd    terminal
votes choice ch.  ch.      zero

...
1       1     2     3       0       # voted for candidate 1,2 and 3 in that order
1       2     3     4       0       # voted for candidate 2,3 and 4 in that order
1       1     0     0       0       # only voted for candidate 1           (A)
1       1     0     0       0
1       1     2     0       0       # only voted for candidates 1 and 2    (B)
1       1     2     4       0
1       1     3     2       0
...

Who is "candidate 1" and so on is given by the order of the names near the end of the vote file.
The first column is always 1 for SE elections (identical votes are not aggregated,
but the file format supports such aggregation), and the last column is always 0.
That these were used can be seen by the Exhausted vote in round 2 here. That's the votes like
the one I marked "(A)" contributing 38% of their vote toward electing one moderator, but then wasting the remainder of their vote, by then failing to express any opinion about the later candidates in respect of the second open position. While it's possible some of them might have felt there was no way to distinguish the later candidates' suitability, I suspect the main cause for many of those is simply lack of understanding of how single transferrable voting (STV) works.
People who voted "1 2 0" or something like that (such as "(B)" in the above) used more of their vote. There was no third round (but it was possible there could have been one), so the absence of their third choice had no impact at all, and as it happened, no votes other than "1 0 0" were prematurely exhausted.
They all counted as they should for an STV election.

Using all votes in Elections


No more "needs work" categories

Question: Along the lines of "Third excellent...", we now have no more "needs work" categories, having just bumped over the 5 questions/day mark. This is more of an announcement than a question, so it can be removed later if necessary.
Comment: we dropped below 5 again ... I think it is going to take another week or so (hope I am not being too optimistic) before our questions per day says as okay.
Comment: Unfortunately yes. I will note that with over 1000 questions, there are only 11 "unanswered" questions, which is really very good.
Comment: Is it some software error? 1050 q/260 days in beta only makes 4 q/day...
Comment: @Shyam - I think the value is a rolling mean, but I'm not sure for what period. For visitors per day, it's the rolling 2-week median.
Answer: Congrats to all on reaching this nice milestone! (and there's no need to be modest: a lot of SE sites in beta have a hard time maintaining a steady stream of questions after the initial excitement)
Being a newcomer, if I may take this opportunity to give my main impression for my first month here: by increasing our userbase more we will be able to cover more fields of research… and this diversity will bring even more value to the site. Academia is a broad church!

A related reminder (yes, I saw someone say "more like nagging"): we have proposed an ad to run on our sibling Stack Exchange sites, but they need our votes to run. If you have an account on the following SE sites, please go up vote the ad:

TeX: only 1 last vote needed
English L&U: 2 more votes needed
Mathematics: 3 more votes needed
Physics: 4 votes needed

PS: the ad itself is a graphics I created with Daniel's advice… but I am in no way emotionally attached to it, so please consider improving on it or proposing a better design in the relevant meta discussion.
Answer: Thanks for posting, good job to everyone who's participated and made this site as good as it is.

No more "needs work" categories