How to access "Configure" page to set up bridge relay

Question: I downloaded the latest Tor version and now need to configure a bridge relay, as the web site I am trying to view is still banning me (www.godlikeproductions.com). They must have very sophisticated IP identification software. How do I go to the "Configure" page since the Tor browser is now loaded?
Answer: If a site is banning 'you' (they actually ban all Tor exit nodes) then using bridges will not help you.
Bridges are an alternative way to enter the Tor network, which can be useful if your ISP blocks you from connecting to a normal Tor guard relay.
Regardless of whether you use a bridge or not, you still exit the network through the same exit nodes.
In order to visit that site, you can look for a different VPN or proxy service, one that they haven't banned.

(Edit to add, to answer the actual question..)
To setup bridges,

Click on the Tor Button,
Select 'Tor Network Settings',
Check 'My Internet Service Provider (ISP) blocks connections to the Tor network'.


What does recommended for acceptance mean?

Question: I applied to a computer science PhD program and received an email saying the department admissions committee has recommended me for acceptance to the program. What does it mean "recommended"? Isn't it the department making the decision?
Answer: Not always. At some universities (such as the one where I presently work, the official decision to admit a student is made at the dean's level, rather than the departmental level. In such cases, the department recommends admission; such recommendations are almost always accepted, unless something irregular has happened in the admissions process.
Comment: The most common case of not getting accepted at this stage is a low TOEFL score.
Answer: Another reason for careful wording like "recommended" may be that they have not yet received the expected funding that would support you, so they have to wait before they give you more definite wording.
Answer: Yes, what aeismail said is correct. The recommendation for admission means that the department has judged you an eligible candidate, and they are recommending your acceptance to the level that makes the final acceptance (Dean/Admissions Office etc. depending on the context). I've never heard of anyone not being accepted after receiving a recommendation of acceptance.


Version control for database objects

Question: The database our developers are working on is too large (have a lot of database objects). We have to control db objects changes (change management). Our company cannot have a person who would be responsible for db changes only. So we need a source safe for database objects, something like version control for standard code, but more related to database, that can synchronize database and scripts. What is the best one. Reliable, Cheap, Functional - choose the two ones :)
Comment: See: http://dba.stackexchange.com/questions/2/how-can-a-group-track-database-schema-changes
Answer:
Red Gate SQL Server Source Control
Visual Studio Database Projects
Developer discipline
Answer: ApexSQL Version, supports Visual Source Safe, Subversion, Team Foundation Server, SourceGear Vault and MSSCCI compliant versioning systems
Answer:
Usual Database/Server projects in Visual Studio
RedGate SQL Source Control

both are compatible with TFS and SVN/Hg
Answer: Our team uses Visual Studio 2010 Database Projects.  Most of our projects rely on MS Team Foundation Server for source control, which integrates seamlessly, but I found out recently it will work (with only a little pain) on other source systems.  We have one such project on Perforce.  The build and deploy features of VS2010 work very well and can be automated using PowerShell (very useful if for instance you wanted to restore a baseline to test deployments).  Different configurations can be created if for example you want a full or differential deployment target.
You can also include data population or other scripts with your deployment, and those go under version control as well.  Database objects may be managed by checking in scripts you create or you can use the more intuitive schema view.  All of the dependancies are tracked.  You can manage every aspect of your SQL Server DB under source control, including all of the properties, files and file groups, and permissions.  Great for keeping standards and practices in place.  It has a visual database diff tool, I prefer Red-Gate's implemtation of this feature, but you don't use the graphical compare to create deployments in VS2010 and it's become moot as I've grown comfortable with the MS builds and how much they help me keep my DB projects clean.
Unfortunately, I cannot compare at this level of depth with other systems for keeping databases under source control. I've worked quite a bit with "developer discipline", but I no longer consider that a system and never want to go back to that. Also had a brief stint using an SSMS plug-in to SVN but that was quite awhile ago. For that we had to use Red-Gate to generate deployment scripts.
Answer:
SourceAnywhere Standalone

The source control tool is designed to be a replacement of VSS and can integrate with SQL Server Management Studio.
Answer: DB Ghost is a good tool for versionizing your databases.  Sync, compare, delta, copy, build, script...and it can be run via command line for automated jobs.
http://www.dbghost.com/
Answer: SQL Server 2008 R2 (and earlier) Source Control FYI:
Database objects are not directly protected by the source control provider…
Meaning you still have to use a disciplined convention…
Because you can still make changes to database objects using other tools…
http://technet.microsoft.com/en-us/library/ms173550%28v=sql.105%29.aspx
Unlike MS database projects RedGate SQL Source Control connects your databases to your version control system…
http://www.red-gate.com/products/sql-development/sql-source-control/
Answer: We've just released our Database Enforced Change Management solution to MS-SQL.
Yes - I'm biased as I work in DBmaestro
I believe our product answer your needs and I would encourage you to read a comprehensive, unbiased review on Database Enforced Management Solution by veteran Database expert Ben Taylor which he posted on LinkedIn https://www.linkedin.com/pulse/article/20140907002729-287832-solve-database-change-mangement-with-dbmaestro
Answer: Our system Sql Historian removes the need for "developer discipline" by automatically maintaining the latest version of your db objects into SVN or TFS. It was designed to be transparent to your developers' current workflow, so you will have a perfect record in version control without any loss of time or complaints from the staff.

Version control for database objects


Play store error #963

Question: I have a Xiaomi redmi note 4, last week, I flash super su with TWRP, I change the sd mount to EXT4 because I have a problem, but is solved, and I wipe data. When I reboot the phone to system, all is OK, but I can't install any apk from play store, I get the error 903. I try to wipe data, wipe play store cache, uninstall the updates, reinstall play store, wipe data of google play services, etc... But nothing works. Right now im using Aptoide, please help, thanks you.
Comment: Welcome to Android Enthusiasts! For explanations on the 905, please consult our [google-play-store tag-wiki](/tags/google-play-store/info), which already lists this. I've adjusted the title to only point to the 963 (which is also shown in your screenshot), as a question should only address one issue (be welcome to open another one for the 903 if needed).
Answer: When using the methods reported by @Izzy, none of them solved the issue on my Galaxy On7, rooted to work with Android Pie (9), LineageOS 16 flavour -- using an SD Card as adopted storage.
Here is what I did:

After enabling Developer Options, I checked the option "Force Allow apps on external"
Cleared the play store data;
Rebooted the device

Now all apps on playstore, which I had forcibly moved to the sd card with Titanium Backup, are able to be updated with no issues.
Hope this helps
Answer: The complete error message reads:

{App Name} could not be downloaded due to an error (963).

(just writing this for the benefit of those who cannot understand the language in your screenshot). According to this post on Google's product forum, there are multiple approaches to solve the underlying issue:

uninstall updates of the Google Play Store app
clearing cache and data of the Google Play Store app
unmount and remount the SD card
using the sd card as internal storage (see: adoptable-storage)
moving apps which are installed on the card to internal storage
remove the Google account from the device and then add it back

Detailed instructions for each of those methods can be found behind the link above.
Answer: I have found that if you move or delete a large file (or a few small ones) then you should be able to download and install the app. This has worked for me and works for all of the 900-1000 error codes. I have not encountered all of them so it might not work for some but it does work for this one.
To move correctly
Just move a file to a different storage to the instalation storage.
To move a file go into settings》Storage》Applications (or another catagory)》X》Storage
Then press change to successfully move a file
X=File of choice

Play store error #963


What is the difference between currying and partial function application in practice

Question: I understand the difference between partial function application and a curried function (f(X x Y x Z) -> N vs f(X -> (Y -> (Z -> N)))), but I do not see what the consequence of this difference is when developing software.
Answer: Originally, currying was to simplify analysis, rather than a practical programming technique; in lambda calculus, all functions are unary. Currying is often used at the language level for a similar reason: simplifying the computational model.
Partial application is used when a named, useful function can be implemented in terms of another, more general function simply by fixing an argument.
They remain distinct forms, involving different parts of computation. Consider:
x=>y=>z=>f(x,y)
(y,z)=>f(0,y,z)

Note that a curried function doesn't have any values bound to arguments and takes the arguments in a specific order; once you curry a function, you don't curry the result and don't change the order that the function takes arguments (though you could uncurry and curry to do so). A partial function, in contrast, has values bound to arguments and can be further partially applied along any remaining argument.
Applying a curried function is close to partial application (you don't, after all, curry a function and leave it at that; at some point, you're going to apply it), which is where uses begin to cross over. When you do this, currying is only the first of two steps towards partial application.
Answer: I believe that your question can be rephrased as: why do languages have currying?
It is mostly a question of convenience:
In Ocaml, you could code
 let sum3 x y z = x + y + z;;
 let foo xx yy ll = List.map (sum3 xx yy) ll;;

In Scheme you'll need to explicitly make an anonymous function
 (define (sum3 x y z) (+ x y z))
 (define (foo xx yy ll) (map (lambda (zz) (sum3 xx yy zz)) ll))

Languages with partial applications & currying need practically to have an optimization to avoid creating partial closures everywhere; you don't want the implementation to always apply sum3 as if it was defined as
 let sum3 x =
    fun y ->
      (fun z -> x + y + z)

that is, to allocate 2 intermediate closures when computing sum3 1 2 3 (understood and parsed as ((sum3 1) 2) 3 ...). You want the sum to be computed immediately.


Expamples of municipal decisions register published as open data

Question: can anybody give me any examples of municipal decisions register (eg. planned road closures, approval of private use of public spaces, sanctions issued to citizens for not obeying municipal regulations, list of municipal regulations...).
Answer: Do you have a preference on nation?
In the United States:

Eminent Domain: You need the municipality's record of minutes, usually this can be found on the local website depending on your target state's transparency rules (City of Ocoee Planning Agenda & Minutes).
Planned road closures are not made as part of a municipal decision, it is a direct result of roadway decisions; traffic engineering would come up with a Maintenance of Operational Traffic; which includes roadway closures and other actions.
Sanctions for failure to comply with municipal regulations would be found in the code violations department (Hillsborough County has a searchable list), but most of these would require going down to the municipality to do an information request.
List of Municipal Regulations is something that varies wildly from city to city, you can find them listed on each municipality's, website; but there is no particular comparison checklist.


What is different between 日本間{にほんま}、和室{わしつ} and お座敷{ざしき}

Question: Are they same meaning? How to distinguish when using them?
Answer: 日本間
A room created using traditional Japanese architecture, interior design, construction materials. More of an objective/neutral term relating to the style/structure of the physical room. Japanese houses nowadays are more or less westernized. They are built using modern construction techniques and styles but usually there will be one or more rooms that are created using traditional Japanese style or 日本間. Inherently, these rooms serve certain purposes in the context of a Japanese home. Furthermore, in relation to the other rooms in the house, you can refer to a 日本間 as 和室.
和室
This also means Japanese-style room, but is used as a general term to differentiate from a non-和室 room. For example, modern houses in Japan have bedrooms which have wooden/carpet floors and you sleep on a bed. This would be 洋室. Another example is when you stay at an inn or hotel, you can have a 和室 or 洋室.
お座敷
This refers to a gathering place to enjoy drinks or food in the company of others; naturally it is a Japanese-style room but 座敷 itself doesn't refer to the Japanese nature of the room itself but more of the setting. お座敷 is used often to refer to the setting of an event, drinking party 宴{うたげ}, and also commonly heard is お座敷{ざしき}遊{あそ}び or the games/activities played in the presence of 芸者{げいしゃ}.
Now, this is the common/current interpretation of 座敷. But if you want to know the origins of 座敷, it actually refers to the floor: a floor made of 畳{たたみ} as opposed to wooden planks for the purposes of sitting and socializing. So in this sense, there is a connection to a Japanese-style room. You can research the etymology of 座敷 as there is more historical context which I did not explain here.


How do I report an emergency using ham radio?

Question: If I'm in the wilderness with ham equipment but no phone signal, how would I report an emergency? Is there a particular frequency I would use, a particular protocol or suchlike?
Comment: These answers are all\good.  But if there is an "imminent threat to life or property" then you can use any means necessary, including transmitting out of band directly to first responders.  But be ready for a bunch of red tape if you do so.
Comment: Related: [If I hear a distress call, what is the correct procedure for helping the person?](http://ham.stackexchange.com/q/876/29)
Answer: On voice, use "Mayday Mayday Mayday" at the beginning and end of the transmission. This is only for life-threatening emergencies.
http://en.wikipedia.org/wiki/Mayday_(distress_signal)
For other emergency situations, like reporting a wildfire that does not directly threaten you, use "Break Emergency" at the beginning of the call. This is a good guide to making emergency calls:
http://www.dummies.com/how-to/content/operating-your-ham-radio-in-an-emergency.html
The IARU has established global emergency frequencies. They call these "Emergency Centre of Activity Frequencies".
<code>15m  21.360 MHz
17m  18.160 MHz
20m  14.300 MHz
</code>
In the US, 14.300 MHz has an organized group of monitors.
A full list of regional and country-specific emergency frequencies is here:
http://www.iaru-r1.org/index.php?option=com_content&view=article&id=891&Itemid=246
The Wilderness Protocol for VHF/UHF (http://k4jwm.com/wilderness-protocol.htm) is useful if you have line of sight communication. That might not be the case in mountainous terrain. The Wilderness Protocol was started in the US, so I have no idea how often it is used outside the US.
Finally, amateur radio requires practice for effective emergency use. In a group, you need at least two practiced operators, because one of them might be injured. In most situations, a satellite phone is a better and more reliable choice for backcountry emergency communication. I go into more detail on that in this blog post:
https://observer.wunderwood.org/2011/10/12/emergency-communication-in-the-wilderness/
One good way to get practice with back country operating is to participate in Summits on the Air (SOTA). The common SOTA frequencies might also be a good choice for secondary emergency frequencies, because the SOTA "chasers" often monitor those.
Comment: Just a few comments (I'm a extra class ham, callsign WT1J). 14.336 is the mobile emergency and county hunters frequency - if 14.300 doesn't work, try them next. Here's a real-life story: http://www.eham.net/articles/20777 You will have to choose whether you want an HF radio (which will talk aroudn the world) that also does VHF/UHF or a much lighter VHF/UHF radio which will only work line-of-site or with repeaters. VHF is simple and reliable and you'll probably have it with you when the bad things happen. HF antennas are more complex, but you get to talk to the whole world and over mountains.
Comment: +1 for suggesting SOTA frequencies as a backup plan
Answer: Assuming that you have an amateur radio license makes this easier, but it's quite possible that the UK legal language includes provisions that may be applicable and allow transmission without a license. It depends on the specifics of the emergency in question. I would strongly recommend familiarizing yourself with the relevant definitions in the legal code of your country; it's perfectly possible that an emergency situation allows you to transmit on frequencies you otherwise wouldn't be allowed to, even if the emergency situation does not revolve around you directly (for example, you tune your transceiver across the bands without a license and come across an emergency transmission by someone else).
If possible, find a frequency that is actually in use and where you can hear both stations; it makes it much more likely that someone will hear your call. Call mayday mayday mayday (life-threatening emergency) or break break emergency (non-life-threatening emergency) as soon as is practical (on a handover if you can afford to wait that amount of time), and unless the situation is extremely dire wait a few moments for acknowledgement. Hopefully one of the stations will respond with something like Jim, break for emergency, go ahead emergency. As the remote operator making such a go-ahead request, you want to be extremely concise, clear, and unambigiously tell the breaking station to go ahead with its transmission and all others to cease transmission. Ideally, at this point the remote station operators will have grabbed a blank piece of paper and a writing utensil of some kind, and be prepared to take notes. For the receiving stations to be taking notes is absolutely essential; as a receiver you will not remember the details! Also, all stations able to receive an emergency report should copy it down; if the station making the emergency report goes off the air for whatever reason, the chances are much better that even in the case of heavy interference a complete report can be pieced together by the remaining stations.
Then, I would suggest reporting things in logical order. Stay calm. Consider what information is needed to offer assistance. For a wilderness emergency, I'd state:

The kind of emergency (broken leg, vehicle collision, wildfire, ...).
The position, in some unambigious manner (for example "Grothwick national park distance 30 miles east of Tadwick, distance 12 miles direction north from trail head on the length 72 miles trail"). Spell out numbers ("seven two", possibly even "seven two point zero" rather than "seventytwo"). GPS coordinates if available will greatly help, but if it's an actual emergency, I wouldn't wait for the GPS receiver to get a fix; you can always complement later.
The assistance required ("need transportation to nearest hospital", "need fire prevention services", ...)

After that, STOP. Say "any receiving station, confirm complete reception of emergency report" or something equally unambigious. Hopefully someone will acknowledge, or at least ask for a repeat of some missed piece of information. Note that there may be stations listening without transmission capability so a lack of response does not necessarily mean that nobody heard you. The ability for a remote station to acknowledge is why I suggest finding a frequency that is actually in use and breaking into the communications.
With any luck, a remote station will respond with something like "confirming complete reception of emergency report, stand by". This is the kind of answer you want. It means they have received everything and is contacting the proper emergency services through some alternate channel, whether that is radio relay, telephone, or some other means. Respond with a short "emergency, standing by" to acknowledge. Issue repeat "emergency, standing by" every 20-30 seconds or so to make it less likely that anybody thinks the frequency is free for use. Hopefully, a minute or two after the initial acknowledgement, the acknowledging station will get back to report that emergency services have been notified about the emergency. At this point, they may relay questions, instructions or otherwise from the emergency services dispatch center. Answer those to the best of your ability, as clearly as you can, just as if you had been calling them yourself.
You may notice an overall theme in all this: clarity, and the repeat transmission of "emergency". Both those serve to help everyone involved. A panicked report does not help anybody, as well as that a random radio amateur is less likely to be trained to deal with someone panic-struck than an emergency services dispatch operator. Repeatedly transmitting "emergency" informs others that the traffic should have extremely high priority. Clarity, including avoiding the use of jargon, helps non-amateurs copy and possibly relay the message to the emergency authorities. All this helps ensure as speedy a response as possible. The exact wordings are much less important than doing your best to remain calm and to provide the pertient information as soon as possible.
In a real emergency situation, I wouldn't worry too much about identification. Do it early if you have the time, but if not, it's better to wait until all essentials have been taken care of. And certainly don't bother with signal strength reports etc. unless the signal quality is exceptionally poor to the point of being outright hard to copy accurately. This is an emergency report, not a rag-chewing amateur radio contact!
Answer: If this is something you are interested in on an ongoing basis as a volunteer, then you should look into joining RACES and/or ARES in the US, and RAYNET in the UK:
http://en.wikipedia.org/wiki/Radio_Amateur_Civil_Emergency_Service
http://en.wikipedia.org/wiki/Amateur_Radio_Emergency_Service
http://en.wikipedia.org/wiki/Radio_Amateurs_Emergency_Network
http://www.raynet-uk.net/
In fact, during major emergencies and disasters, one or both of these organizations may be the only hams allowed to operate, and it will be a very organized effort.
Outside of that, here are the US regulations for licensed hams:
§ 97.403 Safety of life and protection of property.
No provision of these rules prevents the use by an amateur station of any
means of radio communication at its disposal to provide essential communication
needs in connection with the immediate safety of human life and immediate
protection of property when normal communication systems are
not available.
§ 97.405 Station in distress.
(a) No provision of these rules prevents the use by an amateur station in
distress of any means at its disposal to attract attention, make known its condition
and location, and obtain assistance.
(b) No provision of these rules prevents the use by a station, in the exceptional
circumstances described in paragraph (a) of this section, of any
means of radio communications at its disposal to assist a station in distress.
This basically says that under those circumstances in the US, you can operate in any band, in any mode, in an effort to communicate the distress, including the ones you are not licensed for.
Comment: This answer is for the US, but the question is for the UK.
Comment: @KevinReid I would be surprised if the UK does not have fairly similar legal language, though.
Answer: I used the 14.300 maritime net frequency to undeclare an emergency.  My vessel was dismasted in the Gulf Stream during a Bermuda-Newport sailboat race in 2005.
Had the situation been both urgent and life threatening, a repeated 'mayday' would've been appropriate. If urgent but non-life threatening, then 'pan' or 'break' would have gotten everybody quickly in receive mode, at which point the customary information would be asked for. (location, souls on board, etc)
As this was neither a split second nor a life endangerment issue, I waited a few minutes for net control to issue a callup.  An onboard tracker and another vessel both had reported the situation, and the expected result would have been forced abandonment of my boat and a five figure rescue bill.  Luckily, a gentleman in Florida phone patched me into our home phone, where I requested they call off any rescue. To make sure, I also requested they phone to tell the Race Committee I was still competing under jury rig.
Answer: Check out this website or search for "ham radio wilderness protocol": Ham Wilderness Protocol
There are certain frequencies that should be used but there is no guarantee.
Comment: I didn't downvote, but generally link-only answers (or search suggestions) are frowned upon - you should pull out the important bits from the link and include them in your answer.
Comment: When downvoting, please provide a comment as to why (if it isn't obvious).
Comment: k4jwm.com is a dead site. It currently goes to a Chinese gambling site.
Comment: This is a more reliable link: http://www.mdarc.org/activities/ares-races/wilderness-protocol

But I don't recommend using the Wilderness Protocol. It is just too fussy. I've never heard of a successful use of it.
Comment: The Wilderness Protocol is: ""The Wilderness protocol (see page 101, August 1995 QST) calls for hams in the wilderness to announce their presence on, and to monitor, the national calling frequencies for five minutes beginning at the top of the hour, every three hours from 7 AM to 7 PM while in the back country. A ham in a remote location may be able to relay emergency information through another wilderness ham who has better access to a repeater. National calling frequencies: 52.525, 146.52, 223.50, 446.00, 1294.50 MHz."


Can I permanently waive all my past and future copyrights?

Question: Is it possible to commit a "copyright suicide", for example to show disagreement with the system, by publishing a waiver (such as CC0, digitally signed to confirm it was really me who published it) stating that it applies to all past and future works one creates?
Comment: I am not sure that copyright is not something that can be waived.  By putting something in CC0 you are RELYING on copyright to allow them to be freely used.  If you waived the copyright you would not be able to use CC0, which relies on your copyright to give it force.
Comment: Copyright can be waived in some countries -- CC0 is actually not a license, but a waiver, you can look it up. It does contain a fallback license in case it is not possible to waive the rights under some jurisdictions, but the primary intent is to give up the rights.
Answer: You can certainly release any or all of your existing copyrights under a CC0 or similar license which allows anyone to treat them as essentially public domain works. You could publish a statement of intent to do the same with future works. But I don't think that such a statement would be binding on your future actions, nor that another person could rely on it with assurance as regards works not yet created as of the time of the statement. I think you would need to release each work in turn as you create it to have this effect.


Raspberry Pi Frozen

Question: Hi my Raspberry Pi has frozen, and I am not sure what is the safest way to restart/shut down without doing any damage.
Comment: If it's frozen there's not much you can do, just unplug it and cross your fingers.  You won't damage the hardware that way, you just risk filesystem corruption.
Comment: If it is frozen you should be okay just to pull the plug.  You are advised not to do that if the Pi is writing the SD card but that won't be happening if it's frozen.
Comment: OK thanks. I was a bit worried as I am only new to it.
Comment: @goldilocks Can you post this comment as an answer? For completely 100% frozen this is the only solution (and it is nice to hear that filesystem corruption is the worst possible consequence).
Answer: You did not indicate of you where in the terminal or GUI and what you were doing when the Raspberry Pi became frozen.  Sometimes the GUI or even the terminal can freeze, but the operating system is still running, fully functional.
What you can do is to switch to a "backup" text terminal.  Pressing CTRL+ALT+F1 will switch to one of the "backup" terminals offered by the kernel.
You can then log in and kill the offending process that cause the GUI or terminal to freeze.  In your case you can then do sudo halt or sudo reboot to restart if that is all you want to do.
I opt for this when my Pi freezes an I don't want to risk filesystem corruption.
Be aware, if the CPU is being used 100% the switch may take more than a minute to take effect.
To switch back to the GUI, press CTRL+ALT+F7.
Comment: +1 But please do not call them "backup terminals". There are at least 6 *virtual terminals* that run a login [getty](http://en.wikipedia.org/wiki/Getty_(Unix)) and are accessible with F1-6.
Answer: What worked for me was holding down Alt+PrtSc while pressing R, E, I, S, B.

R = Switch keyboard from raw mode
E = Send the SIGTERM signal to all processes except init
I = Send the SIGKILL signal to all processes except init
S = Sync all mounted filesystems
B = Immediately reboot the system, without unmounting or syncing filesystems

https://en.wikipedia.org/wiki/Magic_SysRq_key
Comment: A simple Alt+SysRq+F in the case of thrashing also works
Answer: If your rpi is hanging then pulling the plug is the only option left. Keep top running so next time it hangs you can see if something ate all your ram or cpu. watch dmesg may show you a crash
Answer: If you have access to SSH or Putty try logging in via this method. If you need to recover your local console I recommend rebooting the pi by calling sudo reboot from the SSH/Putty console. For reference the default user in Raspbian is pi and the default password is raspberry. SSH is on by default.
Answer: YES! I saved my little RPI3 from a CPR.
With me - the CPU is running above %90, I have attached: HDMI, 1 keybaord and 1 USB wireless mouse. I also have SSH opened from my Mac and a 1-hour software install.
My RPI randomly paused, I think the time on the screen moved. I saved it by removing all USB and the HDMI devices. I blew air into the board and chip.
I then tried to see if I could get a light response from the board. I attempted to connect to VNC and SSH simultaneously. Each time I attempted to SSH in terminal, the green light would flicker.
I gave it a few minutes (about 5) and it began to process slow, then back to normal speeds.
BEST of luck!
Comment: Disconnecting HDMI seemed to help in my case as well. I don't believe blowing into it is necessary and may not be a good idea as moisture and electronics don't mix. Even if it is a matter of overheating, allowing it to cool on its own is safer than blowing into it. Thanks for the help though. Good thinking.
Answer: If you are using the gui, you can try control-alt-backspace. depending on your OS and how you set it up this will restart the x-server and return you to the login prompt, giving you the option to login or reboot/shutdown.
Answer: This is too long for a comment, but it was a combination of answers that worked for me. I'm guessing that the processing graphics was taking up a lot of cpu, although I could not confirm since it was frozen. In my case, three browser tabs were open with one containing a higher quality youtube video. In my experience, freezing on the Raspberry Pi 3 is usually a case of having too many browser tabs open with one or more containing youtube videos. It froze so much that the clock did not update and the cursor would not move.
Solution:
Turn off the monitor and remove the HDMI cable, then reinsert the HDMI and turn the monitor on again. This got things moving, but very slowly. Switch to another virtual terminal by holding CTRL+ALT+F1. I have experienced this on other lxde environments as well where you need to hold these keys to succeed in switching the virtual terminal.
In my case, once focus was changed to another virtual terminal, it was still sluggish at first, but after logging in and running htop, whatever process was hogging the cpu was no longer doing so. This is likely because the GUI environment did not need much processing since it was not running in the current virtual terminal. This gave it enough of a break that switching back to tty7 CTRL+ALT+F7 where the GUI desktop is running allowed the environment to continue functioning as normal.

Raspberry Pi Frozen


Project configuration editor - alternatives to kconfig-frontends and cmake-gui

Question: I'm working on an open-source embedded project which requires quite a lot of configuration - distortos - object-oriented C++ RTOS for microcontrollers. When starting a new project you can select the chip you will be targeting from several hundred supported devices, after that you may select the configuration of chip's clock (PLL multipliers, dividers, quartz crystal frequency, ...) and chip's peripherals (whether to enable serial port 1, serial port 2, serial port 5 and so on). During project's evolution you can configure other features of the RTOS (like sizes of stacks, run-time checking and so on).
At this moment the project uses kconfig-frontends, which is a tool used to configure Linux kernel - extracted to be a separate, standalone project. My configuration menus currently look more or less like this:

While kconfig-frontends has quite a lot of nice features, it also has some very serious flaws.

Impossible to build on Windows - one guy created a Windows build of a pretty old 3.12.0 version some time ago, but I never managed to reproduce his results, and his compilation covers only the "mconf" variant (ncurses-bases - pictured above), all other tools are not present in the binary package he uploaded.
Unknown whether it builds on Mac.
In most Linux distros you have to manually build it yourself from source. This is a problem, as people working with microcontrollers (users of my project) are not very used to doing that, and the process is not that easy as you would imagine.
Doing some things is extremely tedious - for example you can "force select" an option, but you cannot "force unselect" it, except hiding it from the user...
Doing some things is impossible - for example dependencies can only be based on bool values, you cannot have some options depend on an exact integer value or a string.
(related to 5.) There are limited possibilities for checking the validity of user's input - for example for integers you can only allow a contiguous range of values, while sometimes a list of valid integers would be more suitable (this can be worked around with a list of bools + hidden integer with default value based on bool, but then see 4. - this is not very practical if there is more than - say - a dozen of allowed values).
I probably forgot about something anyway...

Mainly because of first three items I'm considering moving to some other tool. But the problem here is that I actually only know one alternative - cmake-gui (or ccmake). It nicely solves the most important problems listed above (1-3), but doesn't solve all of them - I'm pretty sure points 4-6 remain in place, maybe affecting some different areas, but still... There are also some more issues with cmake:

With kconfig-frontends the hierarchical structure of the configuration can be freely created - you can have as many levels of menus as you like, arranged anyway you want. With cmake the configuration is flat, with the possibility to group the options by the prefix of each value (more-or-less something like a menu with 2 levels in kconfig-frontends).
There are only strings and bools as "types" of options, having integers with value checking requires some workarounds.
The dependencies among options is very cumbersome. In kconfig-frontends if "option B" depends on "option A" being enabled, then changing value of "option A" results in "option B" being immediately hidden or displayed to the user. In cmake-gui when you have such dependencies, you have to click "Configure" to actually see any effect.

One user of my project created a preliminaty port to cmake and it looks like that:

My question therefore is - are there any other alternatives to kconfig-frontends and cmake-gui? The most important features I'm after are:

easy to use on all major OS platforms;
GUI;

For other features I'm flexible and I may adapt.
I also know that I could write my own configuration tool and ship that with the project, but I'd really prefer not to go that way, unless forced by lack of other options. I prefer to have some GUI tool instead of a typical approach of embedded project - requiring the user to manually edit some header files with all the options. This is because there are way too many things to configure (even though I try to keep the number of options down to a minimum), most of options depending on some other options, and also because some of the options affect the build process, so using .h file for that is not very convenient.
Comment: I have no idea what you're attempting to do, but +1 for the well written and **researched** question!
Comment: @Mawg unfortunately no, I'm going on with CMake and its cmake-gui for now.
Comment: Did you ever find an answer?
Comment: Then perhaps you ought to post that as an answer, and accept it, in order to help others in future
Comment: Latest kernels come with qconf - QT based GUI front-end for kconfig, used for `make xconfig` target. Might be possible to port it on Windows.
Answer: I am just researching the same issue (need a portable configuration option handing tool with UI), and found the Kconfiglib project. It is a kconfig implementation written in python, support console and graphical UI. Please see: https://github.com/ulfalizer/Kconfiglib
(I am in an early phase and did not checked the tool yet. Some may still find Kconfiglib useful.)


What happened to the question "is the mvc software architecture used only in web development"

Question: I had just finished typing a great answer, and It wouldn't let me post?
Comment: @gnat As long as the page was opened in those 6 minutes, he could have spent days on it as long as he didn't close the browser/refresh the page.
Comment: @YannisRizos I've done it myself, you aren't notified until you submit your answer.  (Although if it's entirely through websockets, those don't always work - for example, at work that port is blocked)
Comment: [per screen shot](http://i.stack.imgur.com/q9D7q.png), question has been deleted 6 minutes after being asked, and you managed to think through and type a "great answer" _that_ quickly?
Comment: @Izkata Nope, there's an ajax-y (websocket-y?) notification upon closure/deletion. That said, it's not impossible to write a great answer in 6 minutes or less.
Answer: (10k link - https://softwareengineering.stackexchange.com/questions/219691/is-the-mvc-software-architecture-used-only-in-web-development )
It was deleted by the author of the question - likely when they realized it wasn't going to garner a positive response in its current form.
Comment: both meta and chat require reputation . . . I'm just glad that pse was not my first se site.
Comment: At the time i started my answer it had no score, no answer, and was not marked duplicate. This seems to happen to every question I try to answer here.
Comment: @hildred: Before answering your next question, read http://programmers.stackexchange.com/help/on-topic, and try to get a feel for what we consider good questions here.  Hint:  questions asking us to compile a list of things, or asking for product recommendations, are not what we consider good questions.  Answering such questions decreases your chance of a good outcome.
Comment: And as to it happening again, another screen shot - http://i.stack.imgur.com/Dcnre.png (again, the OP deleted the question)
Comment: I notice how quickly questions get down voted here, even my question which last I checked has a score of 9 had a -2 before it got answered.
Comment: On P.SE, we strive for thorough and complete answers.  Good answers can take a quarter of an hour or longer to think about and properly craft.  Similarly, we appreciate when the person asking the question has put some thought or research into it (rather than a 10 second "I'm wondering about..."). There are sites with even more strict requirements ( http://mathoverflow.net/ and http://cstheory.stackexchange.com/ being two that I can think of off the top of my head and http://networkengineering.stackexchange.com/ doesn't allow home network questions - enterprise only)
Comment: btw: it happened again http://programmers.stackexchange.com/questions/219692/non-animalian-non-vehicular-oop-examples
Comment: The OP deleted the question 1 minute after I posted my comment asking for clarification.  It wasn't through any intervention by anyone else. Your best approach would be to look at ones that show that they've put some thought into asking the question.
Comment: The ratio of people voting on questions to the rate of new questions is rather high (compared to other SE sites). The history of the site has had some tumultuous times and there are people (you'll note my vote) who try to give prompt feedback on questions (that are sometimes down votes) to help people realize they need to work on improving their question (or answer) before we get poor answers on it and it becomes a more difficult thing to fix.  Meta and [chat] are both ways to work on a question before "throwing it to the wolves".
Comment: let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/11717/discussion-between-hildred-and-michaelt)
Comment: @RobertHarvey per your link both questions were on topic.
Comment: The MVC one was a duplicate.  What was the other one?
Comment: @RobertHarvey the other was also likely a duplicate (its in the comment that din't show in the cut) of [What would be the best real example to explain the usefulness of Inheritance ?](http://programmers.stackexchange.com/questions/108148/) (which was a closed question as not-constructive).
Answer: 10k+ only link: This is the question you're asking about
At the time of deletion, it had a suggested duplicate question in the comments.
The owner of the question chose to delete it.


How to use bridges in Orbot?

Question: I am on android 4.4.2. Using Orbot + Orfox. I can connect the Tor network and browse webpages on Orfox when I am connected to a Wi-Fi. But whenever I turn-off wi-fi and try Mobile data, the pages on Orfox does not load. Here, How to make Tor work using mobile data?, they mention that mobile carriers may block access to Tor. And it is suggested that I should use bridges available. How can I do that? Checking "Use Bridges" option on android app does not resolve the issue (I haven't entered any IP address and port of bridges, since I do not know how to do it.)
Comment: @canonizingironize I fetched some bridges from the address you provided. On the android app Orbot, I checked "use bridges". And entered the IP address and port of the bridge. The pages in Orfox still didn't load on Mobile data. I tried two different bridges, but it didn't resolve the issue.
Comment: First you need to fetch some bridges from https://bridges.torproject.org, pick obfs4 bridges
Comment: Did you also add the fingerprint, crt and iat-mode values provided in the bridge line?
Comment: @canonizingironize I haven't added the fingerprint, crt, and iat-mode values. Now, I added them. I just copied and posted whatever the bridges.torproject.org provided me. Now it works. Now, I can connect through Tor network using Mobile data. Thank you.
Answer: 1- Get bridges:
Enter bridges.torproject.org on your mobile browser. On the page opened, click on "Get Bridges" option. Scroll down to the "Advanced Options" box, and select "obfs4" on "Do you need a Pluggable Transport?". I didn't meddle with the "Do you need IPv6 Addresses?" option. By default, I found the "Advanced Options" box already selected as "obfs4" and "Do you need IPv6 Addresses?"  box unchecked. Then, click on get bridges. Do the captcha. Get the bridge IP's and ports and other information.
2- Apply bridge settings on Orbot:
On mobile, click Orbot app. Get to settings in the app. Scroll down to the "Bridges" header. Check "Use Bridges" option. Then go back to your mobile browser and copy all the line that bridges.torproject.org gives you as bridge information. Copy all the line. Then, head back to the Orbot app options, and click "Bridges" option. Paste the copied information in the pop-up. Click "OK".
3- Restart your mobile device:
Now, at first, I wasn't aware that I needed to restart my mobile device. So, the changes didn't have any effect. But, after restarting my mobile device, the changes seem to get applied. Now, I can connect to the internet through Tor network on mobile data.
Comment: You mean the whole line?
Answer: First, you have to get orbot
to get that on your phone there two ways which I know:

using F-Droid
which is accessible from https://f-droid.org but before installing orbot you have to activate Guardian Project Official Releases under F-Droid -> settings -> Repositories.
using Google-Play-Store
which you just type orbot in the search bar and there you go.

After installing Orbot on your device

it's strongly recommended to VPN the whole device traffic through Tor network. so to do that, you have to turn VPN Mode ON in the main page of Orbot.

now you go into settings, come down in settings, and you will see Debug section click on Torrc Custom Config and you will be prompted, you have to enter below lines to use Bridges:
UseBridges 1
ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy

now go up in the settings you will see Bridges Section,

First activate Use Bridges by clicking on it
Then Click on Bridges, and you will be prompted again, and now you have to enter your Bridges - so far so good but now how should I get Bridges?

getting Bridges
use gmail or yahoo mail (I'm not sure about other mail service providers) to compose a mail to firstname.lastname@example.com and fill both subject and mail content with get transport obfs4 (carefull about not having kinda misspelling). now you are done there is a mail back to you from firstname.lastname@example.com in seconds.
Final Step
Now you can enter the bridges you got into obrot -> settings -> Bridges.
below is an obfs4 bridge structure:

obfs4 IP:PORT HASH-OF-YOUR-OBFS4-BRIDGE

now you can come back into the main page and click on onion and turn it on.
as it shows Bootstraped 100%, it should be connected and you can enjoy surfing internet freely. but if it show Proxy Client: unable to connect to IP:PORT ("general SOCKS server failure"), you need to send another mail to firstname.lastname@example.com to get another bridges.

How to use bridges in Orbot?


How should a married person get ordained in Theravada Buddhism?

Question: Can a married person who does not have children ordain if he has the consent of his parents? Does his wife has to give permission? How much contact should he keep with his wife after he ordains?
Answer: A married man need not ask his wife for permission. Even the permission from one's parents was once disregarded by Sariputta (in ordaining Revata).
According to the rules (Pāc. 80), though, a woman has to get permission from her husband. This seems to be a carry-over from patriarchal Indian society. I would suggest that in societies where woman are seen as equals to their husbands rather than property, this rule should be broken. I know this isn't the direction of your question, but just for the sake of completeness, the point of the rule was that angry husbands posed a threat to the sangha (I was almost beaten in modern day Sri Lanka by one such jealous husband for ordaining his wife).
Assuming you are confining your question to men wanting to become bhikkhus, there is no requirement for consent from one's wife. Examples of married men becoming monks (ostensibly without the permission of their wives) are Ratthapāla, Culakāla and Mahākāla, and Yasa.
Note that having children is not a barrier to ordination (for women either).
As for contact between spouses after ordaining, the answer is pretty obvious; the spouse should be treated as any other lay person, though special care should be taken not to fall back into attachment with them. The story of Maha and Cula Kala is instructive in this regard.
Comment: Can you send my the link to (Pāc. 80), I do not find it.
I am the wife and give no permission .
But the family from my husband think just mother need to give permission.
I did not want to but I cried on ordination (hiding)
I thought I am ok with it until it happen.
Comment: Here is a link to (Pāc. 80): http://www.accesstoinsight.org/tipitaka/vin/sv/bhikkhuni-pati.html#pc-part8 -- it says, "*80. Should any bhikkhunī sponsor (the Acceptance of) a trainee without getting permission from her parents or her husband, it is to be confessed.*"
Comment: In most Buddhist countries today it's a matter of law already to need to gain the agreement by ones wife since many used it simply to escape from family responibilities. And to use the holly life deliberated as simply escape from ones responsibilities touches Vinaya as well (in derived manner)
Answer: Married people can ordain. Ideally you should get permission from your wife also though not explicitly required.
You have to limit the relationship to that of any other woman. I.e,

no physical contact or being alone with her
no flirting or anything such talk
you should not get involved in any of her worldly problem like providing for her though you can make the arrangements beforehand

Ideally you should break ties of being your wife or special or significant other but still can be friends treating her like a friend or sister.
If your parents live you have to get their permission.
See the following for more information on the process: http://www.buddhanet.net/e-learning/buddhistworld/ordination1.htm


Does the iPad 2 Support the iPad 1 Dock?

Question: I'm thinking about selling my first generation iPad, but was wondering if I should sell the dock with it. I know that they are coming out with a new iPad dock specifically for the second generation. Will it not fit on the first generation dock?
Comment: I fear you might have to wait until later next week until someone can actually try this :-)
Answer: It's possible to use the first generation dock, but it's a bit difficult to get the iPad 2 connected, because of the tapered edge: See this link.
Answer: Hard to say for sure if the original iPad Dock will work with the iPad 2. Apple is selling an iPad 2 Dock, however, that is different than the original model.
Answer: I would recommend waiting to sell the dock.  I would venture a guess that it will, however, not perfectly. eg, I use my iphone edge dock with my iphone 4 and I think it is great!


What does "hit" mean?

Question: When I meet some phrases with "hit", I often have trouble in understanding the meaning of this word. For example, "hit the bed", "hit the book", "hit the spot", "hit up for" and so on. I know the basic meaning, that means beat, but I can't get these phrases if I don't look them up in the dictionary. The word seems to have no fixed meaning, so how could I feel it's meaning? How to use it to make sentences? I hope someone could help with the problem.
Comment: You need to learn these phrases. Few people explicitly memorize them. Typically you pick them up by reading or listening to enough English material.
Comment: "hit a wall" is another example of an idiom. It means running out of energy or willpower to complete or continue a task. "Hit" is a more versatile verb than it seems, at first, as you can see from the answers below.
Answer: In English, hit is a flexible verb that we use to mean "ask," "act on," "complete," or "do."  More importantly, it implies a certain level of force or the emphatic nature of the action.  It can also carry a slightly negative connotation.
Uses with Emphasis
So you can go to bed, or you can "hit the bed" meaning you are so tired that you're going to basically fall into bed.
When something "hits the spot", it doesn't just fill you up.  It was so good you're not only physically full, but mentally and emotionally.  Something "hits the spot" when it was exactly what you wanted to eat, exactly how you wanted to eat it.  Everything was basically perfect.
If you're going to "hit the books" it means you're going to sit down and study hard.  It implies that you're putting forth a lot of effort to learn something.
If you "hit it off with someone" it means that you not only got along with the person, but you actually connected very well and had a good time.
If you're out to "hit the clubs," you're not just going to a club to hang out.  You're going out to party hard.
And if you're going to "hit the road" or "hit the bricks" you don't just have to go, you had to leave five minutes ago.  One thing is you can say to someone else "Come on, hit the road" or "Go hit the bricks" as a way of telling them to buzz off.  Of the two "Hit the bricks" is a little stronger and more negative.
More Negative Connotations
If someone "hits you up for money," they're not just asking you for a few dollars, they're almost hustling you, or bugging you for money.  It's the difference between "Hey, do you have a few dollars I can borrow" and "Dad, can I have some money please?  please?  please?   please? please?"
Note: you can also "hit someone up for money," and that means you're going to ask them for money, but it still carries a sense being more emphatic in your request.
Someone who is "hitting the bottle" is not enjoying a drink, they are drinking to get drunk, and usually because they have a problem with alcohol or they're in a bad place in life.  You'd never say to a friend "Let's go hit the bottle!"  You'd only ever say "Man, since Jimmy's dog died he's really been hitting the bottle."
Miscellaneous
There's a few other cases, like "taking a hit," which basically means taking a piece of something, usually drugs or alcohol, but that's about it.  And if something "hits you hard" it affected you strongly, either positively or negatively depending on the situation.
There are two songs that jump to mind that have nothing to do with actually beating someone: Pat Benatar's "Hit Me With Your Best Shot," and Britney Spears "Hit Me Baby One More Time."  Benatar's song is saying "No matter what you try, I'm going to be alright."  Spears is saying "I need you, please let me see you again."
The best way to think about hit is it's a way to a shade of meaning in English without having to use a bunch of adverbs.  I hope this has helped!
Comment: This is a stellar answer. I'll make one small addition: sometimes a native speaker will use one of these idioms flippantly, so that the "emphasis" may be conspicuously absent from the reality. For example, my son might say, "Dad, I've gotta hit the books now," but then do some homework for 10 hasty minutes and get right back to his Facebooking. In that case, he was using "hit the books" as an expression for "do a little homework." But I'm not disagreeing with this answer, I'm merely adding a footnote for the learner.
Comment: I'm glad you liked the answer.  Thank you so much!
Comment: I like how Google Translate describes one of the informal meanings of "hit": used to convey that someone is engaging in a particular pursuit or activity with enthusiasm. Example: "we went to Val d'Isère to hit the shops"
Comment: Could you please clarify the meaning of "Hit Me Baby One More Time" more explicitely ?  From my point of view, it means "f### me once more, baby".  I'm 99% sure now, but a doubt remains, and I'd really like to wipe it out. (or know how wrong I am :p)
Answer: Longman DCE has about 15 idiomatic expressions of colloquial level that one has to learn.
Here is a selection. One has to get a feeling for such idiomatic use of to hit in informal language and often it is necessary to consult a larger dictionary.
B books: to hit the books - Mentioned above. To study, to begin learning
B bottle: to hit the bottle - to start drinking too much alcohol regularly
D dirt/deck: to hit the dirt/the deck: When you are shot at, you hit the dirt/ the deck to avoid getting a bullet
H hay: to hit the hay, AmE - to go to bed, to sleep, to turn in
R road: to hit the road - Longman: to begin a journey
Comment: that means the only way to master the word is to learn.but i can't use it flexibly if i just memorize these phrases,it's difficult for me to use it to make authentic sentences by myself, because i can't understand it deeply.
Comment: @christinalee the more you interact with people the better it is for learning. You will hear these phrases over and over again and you will gain an English understanding of what they mean. There are phrases/words that I know what they mean but cannot explain them in my native language
Comment: It's no use trying to invent expressions on one's own.
Answer: As has been said, they're 'stock' phrases that everyone has become accustomed to. They're not really things you make up yourself, unless your intended meaning is very clear.
If I just said, 'I'm going to hit the kettle', it really wouldn't give anyone the immediate impression that I was going to make tea.
Though if it was repeated often enough to become a meme, as the existing ones, then it would become gradually more acceptable.
Someone has to be first to coin one, I guess.
I think your basic error is that you are looking only at the word 'hit' itself & not the complete structure of the idiomatic phrase.
In each of 'hit the sack/bottle/road' etc there is no real sense of 'hitting', but 'using' or 'starting' - 'employing' perhaps [in the sense of use, not offer a job to].
In 'hit the spot' there remains the sense of hitting, like an arrow hitting its target, or intended spot [place].
I think the most confusing of your examples is 'to hit up' because that one is the most idiomatic & the least decipherable. You just have to know what it means. That one is also very definitely US Eng & has as far as I'm aware, only been recently adopted into Br Eng. I can remember not understanding it when I first heard it. Context allowed me to figure it out, the words themselves gave me no clue.
"She hit me up for fifty bucks!" [at this point I have no idea]
"Did you giver her the money?"
"No, I loaned her twenty" [ahh… now I've got it.]
One that doesn't seem to have been mentioned so far is "Hit me" or "Hit me again", which is usually "Give me [another] drink", or in card games, another card.
That one is possibly best to use when there is no opportunity for confusion - less painful, that way ;-)
Comment: I think most uses of "hit" do imply coming into contact with something or using it in an understood purpose.  In "hit the books", you can infer that someone is going to grab a book and "use" it.  I think that's the most essential part of your answer for someone that wants to learn how to interpret a phrase.  Also, one more - to "take a hit" of a drug or alcohol, which would be a swallow from a bottle or a single puff of something that is smoked.  Using one single unit of a drug.
Comment: @Tetsujin you're right .we need context or dialogue to help us understand,not a single word .and i think the best way to understand is through dialogue.but it's a pity that there's few dialogue in our textbook,instead of this,there're a lot of written languages that doesn't apply to oral communication and even are hard for us to understand.
Comment: I'm sure the way a lot of people do it is to watch American TV with subtitles.
Answer: They pretty much exist as set phrases, so you just have to learn them. As you can see, no "hitting" is involved.

There will be a test soon so I will need to hit the books. (I need to study)
  That beer sure hit the spot. (The beer was what I needed and is very satisfying.)
  I heard that she hit him up for 50.00. (She asked him for 50.00.)

I have not heard hit the bed but I imagine it means to flop onto the bed when you are very tired.
(AmE disclaimer)
Comment: I think I have heard _hit the bed,_ but _hit the hay_ or _hit the sack_ are certainly much more common.  OP - keep an eye out for _hit the head,_ which is a fairly common,  informal way to announce that one is going to use the toilet.  I don't know if I have ever heard a woman use the expression.
Comment: I think this answer **hits the nail on the head**. (It's accurate and doesn't contain any erroneous information.)

What does "hit" mean?


ECDH-ECDSA Combination

Question: I am doing research on cryptography primitives at a basic level and I faced a question on encryption methods. I understood that ECDH is an approach to for secure key exchange between two parties before the encryption process begins. It is quite useful in symmetric methods that use the same key for encryption and decryption. But I cannot understand the application of key exchange schemes in public-key encryption methods like ECDSA since only public keys are shared between two parties that does not need secure exchange. But such combination (ECDSA/ECDH) seems to happen in protocols like SSL. In what point does exactly secure key exchange methods like ECDH stands in a public key encryption method specifically ECDSA?
Answer: ECDH and ECDSA are two different cryptographic primitives. The one isn't build directly upon the other. ECDH and ECDSA both rely on the same computationally hard problem of elliptic curve cryptography of course.
ECDH is a method of performing key agreement. Both parties can establish a secret value by sending only the public key of their ephemeral or static key pair to the other party. If the key pair of one of the parties is trusted by the other party then that key pair may also be used for authentication. This is however not that common. ECDH is the elliptic curve form of the Diffie-Hellman protocol (the DH in the acronym).
ECDSA is, as the name implies, a digital signature algorithm (DSA). It's the elliptic curve form of DSA. It can be used to authenticate the handshake of the TLS protocol. This authentication includes the key agreement parameters used to derive the master secret. The authentication therefore includes the correctness of the session key.
As you can see above, the actual ECDH and ECDSA may be used together in the handshake of the TLS protocol. They are however independent of each other with regards to operation. This is also why ECDH and RSA combinations can exist. ECDH and ECDSA just happen to share the same cryptographic principles.
Comment: You can of course take a look at the [answer of SEJPM](http://crypto.stackexchange.com/a/32520/1172) *how* they share those same cryptographic / mathematic principles.
Answer: Your question is not quite not easy to understand, but I'll give an answer to the following interpretation of your question:

How is ECDH used in ECDSA? Or differently formulated: How to build an ECDSA signer and verifier from ECDH?

I'll follow the documentation (and strip) the documentation from Wikipedia here.
First, compute the public key $Q=d_A\times G$. Clearly this is the same as with ECDH where you'd also exchange $Q$ with the other party for later key derivation.
Second, to sign a message, compute $R=k\times G$ (with $k$ chosen uniformly at random and smaller than the group order). Furthermore, cleverly derive $s$ from your private key $d_A$, the ephemeral public key $R_x$, the ephemeral secret key $k$ and the message (hash) $z$.
Lastly, to verify a message, you first cleverly use $R_x$, $z$ and the second signature part $s$ to get $u_1$ and $u_2$ and to calculate $R'=u_1\times G + u_2 \times Q$, where the first summand is a standard "public key generation" and the second is a standard ECDH exchange.
Sadly it is not possible (to my knowledge) to create ECDSA signer solely based on ECDH (say if you have a smartcard supporting ECDH), because $s$ is generated in a way that is not an exponentiation and requires knowledge of $d_A$.
Answer: I am not a math guy, but I wonder if the answer you are seeking is this: the purpose of ECDSA is to assure you that you are talking to the right person, and the purpose of ECDH is to let the two of you come up with a shared session key.
Using DH for the later is important for forward secrecy.  I.e., even if, later, one or both private keys are stolen by the NSA, the session key cannot be regenerated from the decrypted traffic, since the secret DH parameters are lost for good -- they were never stored or transmitted.

ECDH-ECDSA Combination


What is this deception-based party game?

Question: At some point in time I found the rules for a many player party game online and now I'm looking for it again. It involved two teams of players where each player is assigned two English words. Players of the same team would have words in common. The goal was to make contact with the other members of your team by finding other players with words in common with you. I think I discovered this game on the website of some indie designer. Any help finding the title or website of this game would be appreciated.
Answer: This description makes me think of Linq


Does Bitcoin have a physical equivalent like US dollars do?

Question: I can send US dollars electronically and they get recorded electronically at my bank. However I can also get a piece of paper to represent different amounts.  For example, my bank will give me a 'hundred dollar bill' to represent 100 US dollars.  This is the largest amount of US dollars that one US bill can represent.  Billionaires would need a lot of them to carry around their US dollars.  However, at least it is possible in theory.  Does Bitcoin also support using physical paper 'bills' or is it strictly electronic?
Answer: Bitcoin is only stored on the blockchain. Unlike a fiat currency, where the banknote holds inherent value (i.e., the banknote holds its own value - it does not rely on another system to say it has that value, and a $1 banknote will always maintain its value of $1).
Bitcoin is always on the blockchain. A wallet, or paper wallet, only holds the private keys that can spend certain outputs on the bitcoin blockchain. As long as the outputs corresponding to those keys are unspent, a wallet will hold value.
However, once those outputs are spent, a wallet would have no value (unless more transactions created new outputs controlled by that wallet).
Paper wallets allow you to put a private key on a piece of paper. However, if the money controlled by it is spent, the value written on the paper will not be true.
Additionally, Tangem sells banknotes that contain some BTC that cannot be easily spent, making it function more like an actual banknote.
Comment: Tangem looks like an interesting idea, a digital equivalent of a paper wallet.
Comment: Yeah, I haven't had the chance to try one for myself, but I'm going to Singapore soon, so I'll probably stop by and see how it works
Answer: You can easily create a Paper Wallet and transfer any amount of Bitcoin that you like there. Note that for security and privacy the site should be downloaded to your computer and used offline. Also of note, some random generators are not truely random allowing at least theoretical attack. I have seen no reviews for the linked site, good or bad.


Can weil and wegen interchangeably be used?

Question: I know weil is a conjunction and wegen is a preposition, but both reply the question "warum". I would like to know in which conditions they must be used.
Answer: Weil is because, wegen is because of.
Example for because;

Warum ist der Boden nass? (Why is the floor wet?)
Weil es geregnet hat. (because it rained.)

Example for because of

Warum bleiben Sie zu Hause? (Why do you stay at home?)
Wegen des schlechten Wetters. (Because of the bad weather.)

The usage of these words is not limited to these meanings and examples in my answer.
Comment: You should pay attention to what after *weil* and *wegen* come. After *weil*, there is a whole sentence but after wegen, there is only noun (with/without an adjective), which describes the situation.
Comment: FWIW, it is "Wegen des Regen**s**". Wegen comes with a Genitiv, although many people colloquially (but not correctly) use a Dativ ("Wegen dem Regen").
Comment: Wegen des Regnen ist der Boden nass.
Weil es geregnet hat, ist der Boden nass.
Wegen des schlechten Wetters bleiben sie zu Hause.
Weil das Wetter schlecht ist, bleiben sie zu Hause

I can rewrite your sentences using wegen and weil, I would like to know but where can't I a sentence  using weil or wegen paraphrase.
Answer: As you have already noticed yourself, "weil" is a conjunction and "wegen" is a preposition. The answer lies there whithin; You simply use these words as you would with any other of the same class of words.
Thus:
use "weil" to connect sentences, e.g:

Ich lache, weil ich froh bin

an use "wegen" before nouns or pronouns, e.g:

Ich weine, wegen des sauren Weines

And both together in one esentence:

Ich beklage mich nicht, weil er so blöd ist, sondern wegen seiner Dummheit
Comment: Can you please explain the situations "blöd" and "Dummheit" in your language. When somebody is stupid that means this is his lifestyle, I mean he is always stupid(like me :D), but when somebody has Dummheit that is not his lifestyle, he does foolish things very rarely, right?
Comment: @This was only meant tounge in cheek, and as an example of a sentence with both expressions. It might not make sense, but I believe it is grammatically correct.
Answer: Since you seem to want to know in what circumstances you can't paraphrase a phrase containing wegen with a sentence containing weil:
Wegen, being, as you know, a preposition, and therefore only needing a noun afterwards, allows you to be much more ambiguous than weil, which always needs a complete sentence, i.e. usually at least a noun and a predicate. Thus, you can easily substitute weil das Wetter schlecht war for _wegen des schlechten Wetters in

Ich konnte nicht kommen, weil das Wetter schlecht war.

But wegen allows you to be less specific:

Ich konnte wegen eines Unfalls nicht kommen.

This allows you, for example, to conceal whether it was you that had the accident or someone else entirely.
An example would be the sentence you often hear in the underground:

Wegen eines technischen Problems kommt es zu unregelmäßigen Abfahrtszeiten.

Here, the speaker deftly manages to avoid explicitly saying something like

Weil wir ein technisches Problem haben, kommt es zu unregelmäßigen Abfahrtszeiten.

which would sound much worse, because it explicitly links the operating company and the techincal problem.
Comment: Interesting point.
Answer: I will contribute a very obscure additional observation:
In everyday language of the most negligent fashion you may sometimes hear things like this:

Ich konnt' nich' zur Tür weil, der Pudding.

which in standard German would be:

Ich konnte nicht zur Tür kommen wegen des Puddings.

(Imagine somebody cooking a pudding, the door bell rings, but he cannot go and open the door because he has to continue stirring the milk so it does not
burn. Sorry for the prosaic example.)
There is a slight pause betweeen 'weil' and what follows. Therefore the comma here.
Of course, this is pure oral usage. You never will write this.
Now, even more attentive users of German will find the 'correct' way of expressing it too circumstantial, and therefore even they would tend to slur the words.

Ich konnt' nich' zur Tür wegm Pudding. [or wegen-m, both from 'wegen dem']

Again, that's pure oral usage.
Comment: "Der Dativ ist dem Genitiv sein Tod" is the title of a book where your last example is described in detail. A lot of people fail in using the Dativ and Genitiv correctly by saying things like "Ich kann nicht kommen wegen dem Wetter"(Dativ) when it has to be "wegen des Wetters"(Genitiv). But i really never heard anything like your first example in 31 years of my life. At least not from a native german speaker.


How can I reduce the space between icons on wingpanel?

Question: It is possible to remove this wasted space?
Comment: nope you cant, this is not in any config file is compiled from source, for that you must clone the source xode from github change de space, recompile and replace thte file in your system, thus when you computer updates it will erase your file and put the old one again
Comment: @RenatoA This should be an answer (and a good one) instead of a comment.
Answer: I was able to adjust mine.  Not sure if an update will affect it but now that i know where it is at i can reset it back to my liking should an update change it.
First, open files as an administrator.  Do this by right clicking files and selecting open as administrator.  Then you will have to select the root file system folder on the left hand side.  from there, here is the path to the file you will change.
usr/share/themes/elementary/gt-k3.0

The file you are going to change is named apps.css. I opened it with code by right clicking and selecting code from the "open with" selection.
NOTE: If there are lock symbols on the files and folders than you are not in as an administrator. You will not to be able to save your changes unless you are an administrator.
Once into the file, scroll most of the way down until you see:
composited-indicator {
    padding: 0 6px;
}

.composited-indicator > revealer label,
.composited-indicator > revealer image,
.composited-indicator > revealer spinner {

the line that says:
padding 0 6px;

Is the one that you will modify. Change the 6 to a 2. It should then look like:
composited-indicator {
    padding: 0 2px;
}

.composited-indicator > revealer label,
.composited-indicator > revealer image,
.composited-indicator > revealer spinner {

Once done exit and restart your system.
Update:  This answer is not my own, i had found this work around previously here on the site but haven't relocated it in order to provide a link and kudos back to the original poster.  if someone does find it please feel free to post link.
Update 2.0: link to original answer,
How do I decrease the gap between icons in the status tray?
Comment: Only one clarification, the path is: /usr/share/themes/elementary/gtk-3.0
Answer: I will say "you can't" because it's very difficult and useless, what makes that space in Wingpanel isn't in any config file of the system, actually this kind of stuff is compiled from source code.
If you want to try the hard method,

You will never be able to upgrade your system anymore (because it will erase your changes).
You must know Vala very well and look for that line of code here.

Then you must compile the new source file, for finally add it to your system.
Good luck, I think is more easy to teach some UI lessons to the Elementary OS team. Or just hoping that they admit your line of code in Github.
Answer: This method taken from this comment on Github worked for me on 5.1 Hera:

Create a ~/.config/gtk-3.0/gtk.css file
Insert the below contents

/* source: https://github.com/mdh34/elementary-indicators/issues/1 */
.composited-indicator {
    padding: 0 2px;
}

Reboot your system

The other methods above didn't work for me in Hera, as .composited-indicator no longer exists within /usr/share/themes/elementary/gtk-3.0/apps.css. This is probably a better method anyway, because ~/.config user config, and so is less likely to be reverted when Wingpanel or the theme is updated in the future.
Answer: Is there a way to do this on 5.1 Hera? If I go to /usr/share/themes/elementary/gtk-3.0/
and edit apps.css, there is no line containing
composited-indicator {
    padding: 0 6px;
}

Answer: marcussacana solution from https://github.com/mdh34/elementary-indicators/issues/1
Okay, I tried the community fork, and builded by myself, here is the git, and if you don't want build:

Install the wingpanel indicator .deb here (the same deb in
the link of this git)

Download
libayatana_compatibility.so.zip

Go To (with sudo)
/usr/lib/x86_64-linux-gnu/wingpanel/
cd /usr/lib/x86_64-linux-gnu/wingpanel/

Backup your
libayatana_compatibility.so
sudo cp libayatana_compatibility.so libayatana_compatibility.so.copy

Replace the
libayatana_compatibility.so with the zipped one
cd ~
cd Downloads
sudo apt install unzip
unzip libayatana_compatibility.so.zip
sudo cp libayatana_compatibility.so /usr/lib/x86_64-linux-gnu/wingpanel/

Reboot


Are evolutionary mutations spontaneous?

Question: My question is whether mutations which lead to evolution occur by any environmental force or it occur spontaneously? I have read in genetics that x-rays, ultraviolet rays and chemical mutagens are the causes of mutation but how are they responsible for evolutionary mutations?
Comment: Why do you distinguish between "mutation" and "evolutionary mutation"? What do you think is the difference?
Comment: I think all mutations do not lead to evolution and I wrote evolutionary mutation because I wanted to know the variations that contributes in evolution.
Comment: Your comment shows that you do not understand the definition of evolution. I would recommend that you have a quick look at a short intro course to evolutionary biology such as [Understanding Evolution by UC Berkeley](http://evolution.berkeley.edu/evolibrary/article/evo_01) for example.
Answer: Mutations occur spontaneously because all molecular processes are stochastic in nature: DNA replication is an imperfect process. However, certain external factors can increase the probability of a mutation to occur or even cause specific types of mutations.
Both spontaneous mutations and this kind of externally driven mutation contribute to the genetic variability that is the basis for evolution. It is sufficient that variation exist for evolution to be possible, no matter the origin of this variation. X-rays are probably not common in nature, but there is plenty UV on the surface of earth, and there probably exist chemical mutagens that are formed without human contribution.
Comment: @Nathaniel Interesting, sources for that?
Comment: You should also mention that mutation is a highly biologically controlled process. Many experiments have shown that mutation rates themselves can change in response to evolutionary pressures. So at least some mutations are not just the result of "imperfections" in DNA replication but are actually an evolved feature of the replication mechanism.
Comment: [This answer is very related](http://biology.stackexchange.com/questions/29837/what-are-the-major-causes-of-mutations-in-dna/29840#29840)
Answer: Evolution is, by definition, not spontaneous.
Be wary of conflating "mutation" with "new or changed features".
Mutation is only one of many causes for feature change between generations; inheriting traits from parents is another. Changes in nutrition and education can cause population-wide changes in height and IQ, without being based on mutation. All these things can lead to new features without mutation being involved at all.
The term mutation covers a lot of things which can cause inheritable and non-inheritable visible changes in future generations.
A genetic mutation (as opposed to an in-utero developmental mutation, etc) is a change in genes. The mutation may be in a non-functional section of the genome, so may do nothing. Or it may cause cell division to fail and kill the child. Or it may do anything in between.
But it's not evolutionary. No mutation is, since mutations are one-off incidents.
Now, over time, favorable genetic mutations may be selected for, and built upon by other mechanisms of feature change, to the point where everyone has it. Again, this is not instant, and will take many generations to spread through everyone.
Answer: In a sense all mutations "lead to evolution". The genetic make up of the population has changed. Some mutations become "fixed", are persistent in the gene pool. You are thinking of evolution as progressive, it isn't; it is statistically adaptive.
Is melanin depletion (pale skin)"evolution"? In gloomy high latitude places it enhances vitamin D production. In hot low latitude places it makes melanomas more likely.

Are evolutionary mutations spontaneous?


Acer laptop screen broken external monitor suddenly not working

Question: I have an acer aspire laptop that has a broken screen, I have been using it for the last few months connected to an external monitor via VGA. I have never had any issue with this setup until the other day the VGA cable fell out of my laptop I put it back in as I normally would but it won't work. I have tested both the cable and monitor and they are fine I have tried "fn" + "f5" I can see my laptop adjust but not nothing happens on the external. The only time I get anything on the external is occasionally when I log in the monitor show the welcome windows page in poor quality but drops out before going to my desktop. This is leading me to believe that there is something wrong with either my video card VGA output, if this is the case can I get a USB to VGA adaptor?
Thank you your help is appreciated
Answer: While you could indeed get a USB to VGA adapter the chance that it will work without having to configure it is very small, due to this I think you won't be able to install it...
Instead you should contact acer or a computer repair shop to get it repaired.


Should I use an important scene from the middle of my novel as a prologue?

Question: I am a first time novelist with writing experience. I have an idea for my novel that begins with an important scene which actually plays out in the middle of the novel. Should I write this as a prologue? If so, would it be appropriate to start Chapter One with "Two years earlier..."?
Comment: Why do you feel this scene belongs in the middle? You might know certain events predate it in-universe, but it's important to start a story in the narratively right place. But an important scene can belong later because of the story's shape, so I think we need more information first to help you
Comment: Kurt Vonnegut once gave the advice "Start as close to the end as possible." If the scene you have in mind would make a great opening, ask yourself whether the stuff before it needs to be in the novel at all.
Comment: My first instinct was to begin with my protagonist living and navigating life's normal activities, but I don't want to bore the reader with mundane occurrences. My thought was that starting with a pivotal scene might create the hook that will hold a reader. I'm re-thinking that whole approach, based upon answers I've received here, as well as other research. Thank you for your input. Your comments, and other's here, have been extremely helpful.
Comment: I would say, hook the reader with your first chapter, don't rely on a prologue to do that. If you can't write an engaging first chapter, then how will the rest of your story fare when everyone has put the book down? I'm of the belief that prologues are mostly unnecessary. It can be too much information before they have someone to root for and learn about organically. When I pick up a novel, I know nothing, but I learn throughout the story as it progresses. Don't give away your big scene, build the tension towards it.
Answer: It's dangerous.
It can be done well, but there is literary danger in beginning with "An Important Scene", as opposed to an unimportant or even forgettable scene. The danger is in the utter lack of audience engagement.
Before a novel (or movie) begins, the reader knows nothing about the characters. They are willing to learn or they wouldn't open the book, but they don't know who the good guys are, who the bad guys are, what the setting is like (fantasy, dystopic, real-life, etc).
We give them clues; we almost always open on the hero (by "open" I mean the first human or human-like being they see). That gives us something to root for. But they are not invested then, they don't know if they care for this hero, like her or dislike her.
If the author opens on a big important scene there is generally too much going on for the reader to process, and the writing tends to be poor because the author is overloading dialogue and exposition with world building and character building that inevitably interferes with and slows down the big scene.
It can fall flat. This is particularly an error made by writers that have been "living with" their characters for some time already, and already love them through knowing them and their quirks and morals and history. What seems clear and natural to the writer, then, in the way the characters are behaving in this big scene, is not at all clear to the reader. The reader is sitting in his living room and from the East comes a squad with a big "A" on their shirts, from the West comes a squad with a big "B" on their shirts, and they start brawling and killing each other. It's just a confusing mess to the reader, and boring, even though this all makes perfect sense to Team A and Team B from the author's POV.
You do have to open with something, but generally the mechanics of a novel or movie tend to open on "The Normal World" for the protagonist(s) for about 5% of the length. There can be conflict to drive the reader through this 5%, but it can be "throwaway" or forgettable conflict; just day-to-day problems for them to solve. The car won't start. The power went out and they woke up late because their alarm did not go off.
It is in that opening we can do a lot of world-building, setting, and character development; then we toss them on the hot grill. Then the reader cares.
I would suggest, instead of flash back or prologue, You open normally with a character introduction, do the world building; but the first complication (around 15% story mark) is your big important scene. Then, just do what JK Rowling did in her first book: Two Years Later. (Hers was ten years, giving Harry time to grow up).
Presumably your hero was doing something two years ago; even if they need to be tangential to the big important scene. Or there are other ways to handle it; give us a short story (10% to 15% of the novel) in which the hero dies; then drop your "Two Years Later" line and re-open on your new hero and their normal life.
It is generally a mistake, for reader psychology, to start talking about "Two Years Ago". What is in the past is done and over, whatever you write sounds like a history lesson and is a pain to read. It is similar to watching a taped sports match when you've already been told who won and by how much; it feels boring. You could have enjoyed it without knowing how it ends, even though rationally speaking the outcome was predetermined; but we are irrational beings, and knowing the outcome makes a difference.
Write it in present tense, it is happening now, and we don't know how it will turn out. Again, obviously, the book is already printed and how it turns out is not in question. But it makes a difference in reading, and the reader will not mind finishing a chapter, turning the page to find "Two Years Later". They won't skip a beat.
Comment: Thank you very much for your input! Your comments have given me cause to re-think my beginning and to execute a better plan. Thanks again.
Comment: This is another answer of mine, in a similar vein, with more detail on beginning a story. https://writing.stackexchange.com/a/36356/26047
Comment: This is another answer of mine, on how to open a novel. Similar advice, more details on "why". https://writing.stackexchange.com/a/35816/26047
Answer: I feel it would be appropriate to start with the something in the vein of "two years earlier" though you may just want to date both events and let the readers work it out, that's more of a personal style thing than a one size fits all.
The issue I see is that if you put that much story between the telling and the event you're either going to have to tell the tale of that scene twice. You could do this by repeating the passage, writing it from another point of view or paraphrasing it. But if there's that much story between the telling and the actual event you won't get away with simply reference it offhand like a lot of stories do when they're telling multiple interwoven narratives close together in the book structure that were separate in time.
Answer: Don't toss out any literary device you have.
Yes, this can work, and work well. In TV it's called the "How we got here" trope. Some examples are The Emperor's New Groove, Fight Club, Inception, and Matrix Reloaded. I believe one of the Terminator movies did this as well. Memento is a famous example of learning an entire story backwards.
One advantage of this trope in literature is that (in books) it has not been sorely overdone.
The answer to whether this is a good idea for you in your current project will depend on (1) the genre you are writing in, (2) the event, (3) your execution, and (4) probably other factors.
Depending on the execution, the layout of the chapters be almost any which way you prefer. I've heard of a book that directs readers to go to chapter thirteen after reading chapter one. Then to chapter six, then four, then fifteen.
It can also work to leave the important scene in the middle--and that order of events would be more typical.
Writing out of order, and then re-ordering later, can also work.
The answer is yes, but you don't need to be wedded to the idea.