What is the basis of the sunk cost fallacy?

Question: Is the so called sunk cost fallacy truly a total fallacy, or does it have some kernel of truth? Certainly it is a widespread instinctive/impulsive form of reasoning. Presumably it must then have had some evolutionary advantage that its application bestowed on organisms who would embrace it. What is this?
Comment: If we go by the dictionary description, "the phenomenon whereby a person is reluctant to abandon a strategy or course of action because they have invested heavily in it, even when it is clear that abandonment would be more beneficial", then yes, it is a "total" fallacy (or rather folly). The problem is that in realistic conditions it is not always "clear" whether abandonment is more beneficial or not. In conditions of future uncertainty, persistence may well have evolutionary advantages, but psychological habits tend to spill over even into situations where they are clearly irrational.
Comment: The idea that any and all characteristic that perdurates through the ages must be beneficial in some way is a gross misconception of evolution. To perdurate a traits does not have to be beneficial, just be not detrimental enough that individuals who have it can live long enough to reproduce. We all have a blind spot because our optic nerve connects to our retina on the wrong face, it has no benefits, and some animals don't have it, sign that it is not some kind of physiological necessity. But it's not enough to kill us before we have kids, so it remains.
Comment: Truly a fallacy?
Answer: I would say it's not a total fallacy. If you're 90% done with something meaningful but you're suffering, quitting might be or might not be a good idea, depending on the activity.
Comment: If you're watching a movie and you're sure you don't like it at all and you're 90% done, it's a good idea to quit.
But if you're 90% done with a college degree and you're suffering, it's a good idea to just push through it and not think of "sunk cost fallacy".
Comment: "Might be or might not be " … can you elaborate or expand on that at all?
Comment: Well, if it is better to continue then it's not a fallacy. If you spent 90% of the money needed, but the value of the result is less than the missing 10%, then continuing is a fallacy.
Comment: People keep arguing scenarios where it is basically a "total fail", that there would not be any reasonable return on the entire investment, not just that the last bit wouldn't pay off. These are scenarios where the project never would have been considered if more information was available earlier. Most sunk cost situations are not that extreme, but unfortunately some are. If you don't like the movie you are watching, maybe decide in the first 10% instead of the last? On the other hand, I got two thirds through a famous book I was enjoying when I hit something that caused me to quit it.
Answer: According to this article (thedecisionlab.com), the sunk cost fallacy stems from the commitment bias. How so?
In the context of cognitive science, a fallacy might be viewed as a defect in reasoning that is prompted by a cognitive bias. For instance, an argument that appeals to popularity might expose a bias to relying on testimony as an epistemological source. Robert Audi, in fact, in his introductory text on epistemology cites five sources: consciousness, perception, memory, reason, and testimony. If we have a psychological susceptibility to conforming to group think, as Solomon Asch's famous experiment tends to confirm, then the susceptibility to selecting testimony over reason is very much in conformance with those in evolutionary psychology and behavioral economics (such as Tversky and Amos) who argue that our biases offer some sort of tradeoff; clearly, in hunter-gatherer societies, where in-group-out-group thinking dominates, one might be able to show that reason is far less important than social conformity. The book On Bullshit would count as evidence towards, that of rhetorical forces, logos may be the least persuasive relative to logos and pathos, if you buy rhetorical theory going back to the Ancient Greeks. (Watch Antz for a playful expose on sociobiological thinking.)
What are the philosophical implications? Well, that psychologism is better than anti-psychologism, and that logic is a subset of the psychological which has certain implications in philosophy of mind, where the question of the metaphysical necessity of a great many things is argued, including what metaphysical necessity itself is. The one caveat that should be published is that this response, this line of reason in philosophy presupposes a naturalized epistemology (SEP) that is heavily indebted to cognitive science. There are philosophical opinions and entire communities who approach the notion of truth and fallacy from a less robust scientific perspective and might rely on more historical philosophical notions.
Answer: It is perhaps worth starting with the question "What is a fallacy?" A fallacy is a connection in a logical argument which does not necessarily follow. There is in fact a wonderfully named "Fallacy fallacy" whereby someone assumes the presence of a fallacy means the conclusion is necessarily false. Most of the informal fallacies are exactly as you allude to; typically helpful rules of thumb. Without making any claim about any genetic basis for thought patterns, you are correct that they are patterns which could "evolve" at least socially. For example, someone who in making a snap decision, appeals to the wisdom of experts or of consensus is likely to do better than someone who doesn't, even though it is logically possible that experts or common understanding may be wrong.
Now, what is the sunk cost fallacy in particular? The Sunk cost fallacy happens when new information reveals that some course of action is not worthwhile, and the person sticks at it anyway. Here are a few reasons that such a pattern may, as you put it, evolve:

Prevarication is costly. That is, continually reevaluating decisions can be so expensive that it can be cheaper to settle on a decision already made. For example, a business with a few employees working on a dead end project may be more efficient than one where all employees are constantly in meetings asking "Are we sure?"
Progress is usually valuable. To be an example of the fallacy, the expected reward must become lower than the expected remaining cost. Let's put some numbers on this for an example: A company starts on a 100k project which they reasonably expect to bring in 300k revenue. 80% of the way through they encounter new information which suggests it will only bring in 50k revenue. It's tempting to say that they "Shouldn't have started" because that revenue is less than their 100k cost (although in fact they made the right decision with the information they had at the time). However, it's probably still the right decision to finish the project and spend the remaining 20k for the 50k return. It's a fallacy to count that they have "80k worth of progress" since the amount originally paid is irrelevant. It is not a mistake to count that they have "80% of progress" and that can swing the balance. Of course if the numbers were different then abandoning it may be the better choice, but it's easy to see how subtle these things can be.
The decision maker may not bear the full cost. In particular, people are notoriously bad at distinguishing "A reasonable bet that didn't work out" and "A bad idea." Because of this, the social cost to a decision maker folding is higher than it should be. While a business may prefer to scrap a project when it becomes clear that it only has a 30% chance of success in terms of expected profit, it may be better for the manager of that project (considering her reputation and personal chance of promotion or dismissal) to hold course.
Almost everything worth doing has some moment where it seems intractable. Perhaps it's the frustration of getting stuck on a critical step in a maths puzzle or the pain of a cramp in the final stretch of a race. A certain amount of raw pigheadedness can be the only thing which gets people through these very visceral obstacles. Perhaps a perfect robotic logician would evaluate differently, but in situations where logic shuts down because "It just hurts" it can be helpful to have a non-analytic faculty capable of going "I don't care. I'm doing this."
Comment: Right, I am a successful programmer mainly because I didn't give up many many times, almost to the point of pigheadedness. There's no benefit to quitting.
Answer: There are situations where you have the choice: Either admit that you made a costly mistake or spend more money on the mistake.
If admitting a mistake is a cost to my reputation and the cost of continuing is paid by someone else (let's say my company, or a customer, or the tax payer), then to me it's a good strategy to continue.
Comment: This pretty much explains the USA.
Answer: From a scientific stance, I think it is a form of "good enough" reasoning, which confers an evolutionary advantage. From a philosophical point of view, I do not consider it a fallacy. There will be a probability that the assumption that the investment cost justifies further investment is correct. Whether any particular decision at any particular time is folly is contingent.
Comment: There is an old saying: "*Better not to begin, but once begun, better to finish.*" I think it was about pursuing self-realization though. I would say it is always good to begin and persist in that.
Answer:
Is the so called sunk cost fallacy truly a total fallacy, or does it have some kernel of truth? Certainly it is a widespread instinctive/impulsive form of reasoning.

Gambling addiction is an excellent example of this fallacy and the outcome dependency.
A gambler keeps pouring money into a slot machine even though the odds are slim because he has already invested and the machine is "ready to payout"
There are two outcomes:

Jackpot - No fallacy.
Out of money, pawned everything - Fallacy.

The sunk cost fallacy is psychological as well which may explain why the behavior persists. Additionally, the belief that winning a Jackpot somehow negates the fallacy helps perpetuate the behavior.
In product development its called "feature creep": the idea that adding new functionality to a losing product will help revive it rather than designing a new product.


What is the best way to write a cron that deletes a very large number old nodes and comments?

Question: I am writing a module the preferably implements a cron job, and possibly a queue, to run sql queries to delete old nodes and their comment. Approximately 20 Million nodes, and about 40 mil comments. I want to run pure mysql queries and bypass the drupal api (as much as I can), for performance reasons. I have already developed the relevant queries and would like to know what would be the best way I could implement this so it does not user Drupal api? This is on drupal 7 by the way.
Comment: Can you be more specific about the queue part?
Answer: I would never think running raw SQL queries is a good idea because that can mess up a lot of things such as site maps, search index, caches, etc.
it's just a node_delete() and shouldn't be much slower that deleting a bunch of rows in multiple tables.
Whatever that is, you will need to implement hook_cron and retrive nodes to be deleted from 'node' table.
If you run a node_delete you won't need to delete comments.
You can limit the number of nodes to delete in a single cron run using LIMIT  keyword.
Update:
You might want to have a look at Delete All module. and there is a patch (which I submitted) to use the Batch API to do the job. From my experience I know even the Batch API can't handle it (or you have to wait several days with the browser open).
You can just use hook_cron to load a bunch of nodes to be deleted, and then delete them in your preferred way (node_delete or raw SQL). Let the cron finish, and in the next run, it will grab some other nodes.
Just get your nodes from node table and limit it with a LIMIT.
Comment: [Just look at this function](http://api.drupal.org/api/drupal/modules%21node%21node.module/function/node_delete_multiple/7) that is used by node_delete. This can kill the system. It runs a query to delete a each node. Using mysql I can run batches.
Comment: see the updated reply.
Answer: I think you should use cron and queue api together with hook_cron_queue_info()
hook_cron_queue_info()

Declare queues holding items that need to be run periodically.
  While there can be only one hook_cron() process running at the same time, there can be any number of processes defined here running. Because of this, long running tasks are much better suited for this API. Items queued in hook_cron() might be processed in the same cron run if there are not many items in the queue, otherwise it might take several requests, which can be run in parallel.
Answer: VBO, or VBO-like functionality.
VBO allows you to specify "entity load capacity", meaning "the number of entities I can load and process at once". The default is 10, but you can easily set it to 100-200 on a system with a bigger memory limit (a gigabyte for instance).
It also allows you to delay execution to cron.
Then, you create a view of 20 million nodes, and use the "select all on all pages" to select them all. VBO will then enqueue them in groups of "entity load capacity" (so each queue item would have 100-200 items, for example), and then on cron each group will be loaded separately, after which entity_delete() will be called for each individual item.
I consider direct db queries in Drupal very unwise. Be very careful if you decide to go that way.
Comment: If mysql is going away then you need to increase max_packet_size, that's a common problem with drupal installations of any size.
Comment: Trust me this won't work very nice with that large dataset.
even though it uses Batch API, it's limited by the number of jobs it can handle. Each batch job has a set of operations - 20m is a large number for that IMO.
Comment: VBO doesn't use Batch API in a "classic" way, so that shouldn't be true. Let us know how it goes, in any case.
Comment: I am having problem deleting one node with this large database. Mysql is going away. It is about 300 GB, views and VBO will break the system.
Answer: Below is what I eventualy ended up doing.
As I mentioned before, with a database with ~20 million nodes and ~90 million comments, all solutions that relies on the drupal API failed because and took way too much time. For example, invoking path delete was taking too much time for with this query SELECT DISTINCT SUBSTRING_INDEX(source, '/', 1) AS path FROM url_alias; for each node. With this query, deleting 1000 nodes did not even finish (queries often timed out). I had to comment out the function responsible for it to be able to finsh on node. I commented out path_delete in path.inc. This took down the average time for deleting 1000 nodes to aporx~ 200 seconds. Still was not good enough to run on a live db.
So I needed to get as close as I could to pure SQL. Here is what I did:
1.Find out all the nodes I am willing to keep and keep their idsin a table.
2. Select all the nodes that I am going to delete based on a criteria and using limits of course.
3. Select all the ids comments of these nodes
4. Delete everything that referecnce them.
The whole operation was then placed in a drush command that takes params and calls the function below.
function _deletes_multiple_from_tables($nids, $cids) {
$transaction = db_transaction();
try {
// fields
db_delete('field_data_body')
->condition('entity_id', $nids, 'IN')
->condition('entity_type', "node", "=")
->execute();

//field_revision_body
db_delete('field_revision_body')
  ->condition('entity_id', $nids, 'IN')
  ->execute();

  if (!empty($cids)) {
    db_delete('field_revision_comment_body')
    ->condition('entity_id', $cids, 'IN')
    ->execute();

    db_delete('field_data_comment_body')
      ->condition('entity_id', $cids, 'IN')
      ->execute();
  }
  // Delete Comments fields

db_delete('field_data_taxonomy_forums')
 ->condition('entity_id', $nids, 'IN')
 ->condition('entity_type', "node", "=")
 ->execute();

  // Delete Comments
db_delete('comment')
  ->condition('nid', $nids, 'IN')
  ->execute();

db_delete('forum')
  ->condition('nid', $nids, 'IN')
  ->execute();

 db_delete('forum')
  ->condition('nid', $nids, 'IN')
  ->execute();

 db_delete('forum_index')
  ->condition('nid', $nids, 'IN')
  ->execute();

 db_delete('node_comment_statistics')
  ->condition('nid', $nids, 'IN')
  ->execute();

db_delete('opengraph_meta')
  ->condition('nid', $nids, 'IN')
  ->execute();

db_delete('print_mail_node_conf')
  ->condition('nid', $nids, 'IN')
  ->execute();

Answer: First thing i would like to mention is the function entity_delete_multiple or the function node_delete_multiple which they both get a bunch of node/entity ids and delete them.
A very good example exist in OG where the module delete nodes referenced to group once it deleted - it use a cron. In the cron worker the module search 250 nodes which need to be deleted.
Another good place to look at is the Message UI module which update in cron/batch massive amount of nodes. You can rely on the code just to get overview on how this need to be done.
Answer: If it were me, I'd create a menu callback function that does a db_query on your nodes.  Then write a cron job on your server that calls that URL.
Comment: Why would you create a menu call back and hit using the URL when you have a nicely implemented system that run crons for you? Whay if a user, robot, hit that url? My site goes down.
Comment: I'd give you code examples, but formatting on this site is near impossible for me.
Comment: This definitely not the way to go. Read about hook_cron.
Comment: I'm familiar with hook_cron.  Why is it not the way to go?
Comment: I think hook_cron isn't a true cron.  It only runs if a user hits the site.  Also, you just use variable_set and variable_get to flag when you're running.  If your fx is called and sees you're running, you just exit.


HTML Unicode Issue: How to display special characters

Question: Currently, I have my webpage set to Unicode/UTF-8.  When trying to display a special character (for example, em dash, double arrow, etc), it shows up as a question mark symbol. I cannot change these characters to the HTML entity equivalent. How can I circumvent this issue?
Comment: What is your source code file encoded in/where does the content come from?
Answer: A question mark in a lozenge, �, indicates a character-level error: the data contains bytes that do no represent any character, according to the character encoding being applied. This typically happens when the document is declared as UTF-8 encoded but is really in iso-8859-1, windows-1252, or some similar encoding. Windows-1252 is a common default encoding used by various programs on Windows platforms. So you may need to open the file in your authoring program and re-save it as UTF-8 encoded.
If problems remain, please post the URL. Posting the code alone is not sufficient, since the character encoding is primarily specified in HTTP headers.
If you see a question mark in a small box, then it might be a font-level problem (lack of glyph in the fonts being used), but this would be very rare for common characters like the em dash. Different browsers have different ways of indicating character- or font-level problems.
Comment: Side note: depending on the font it might also be a white rectangle or a question mark in a rectangle.
Answer: Make sure your document is set to the correct character encoding in the actual code editor, as well as in the doctype. Both are necessary. I spent hours trying to tweak HTML when the only problem was that I needed to set the text setting in Coda.
<code><head>
    <meta charset="utf-8">
</code>
See the following screenshot:
Answer: Make sure your characters are actually UTF-8 characters. They will probably look something like this:
<code>® or U+0020
</code>
http://www.kinsmancreative.com/transfer/char/index.php is a handy site for finding the decimal values of commonly used UTF-8 special characters if you need a reference.


Cannot Publish from ArcMap to ArcGIS Online?

Question: I am attempting to publish an MXD as a map service to ArcGIS Online from ArcMap Desktop 10.3.
I have a home licence and have a Organization account on ArcGIS Online with 60 credits left.  I have published services in the past few months.
When I attempt to Publish a Service from ArcMap, I am requested to create a Connection.  (I already have one working Connection as "User" but nothing as "Publisher".)
I attempt to create a Publish connection to:
http://services.arcgisonline.com/arcgis/services
which I believe is the correct URL, however I get the error message:
"Error: Proxy Server got bad address from remote server(verify the server is running)."
Fiddler shows: [Fiddler] The connection to 'services.arcgisonline.com' failed. Error: TimedOut (0x274c). System.Net.Sockets.SocketException A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 22.214.171.124:8080
I am unsure of where to go from here.  I am not using a proxy server. I have searched for this problem and found suggested solutions. I have applied the Internet Explorer fix and the ArcGIS Administrator fix but these have not worked.
Answer: Solved thanks to ESRI Australia support. I had been setting up connections with my Esri login instead of using my Organizational Name login. This is probably only something that is likely to happen to Home users as only one Organization user is allowed, and that is me.
Other users will only have an Organizational login.
Also, I had to create the connection under My Hosted Services.


Are "prototypical" and "prototypal" different?

Question: I typed prototypal inheritance and got a wavy red underline conveying a alternative word for the same from Google. I am getting the same underline while typing this post. The suggestion is prototypical. Does prototypal exist as a word?
Answer: prototypal inheritance  is a technical term used in computer programming. The adjective indicates that the programming style is based on protypes.

Prototype-based programming is a style of object-oriented programming
  in which behaviour reuse (known as inheritance) is performed via a
  process of cloning existing objects that serve as prototypes. This
  model can also be known as prototypal, prototype-oriented, classless,
  or instance-based programming. Wikipedia

prototypical inheritance  would mean something different. It would indicate that the [mechanism of] inheritance  was itself a prototype.
Answer
Although in everyday English, 'prototypal' and 'prototypical' are synonyms with the former being the rarely used version, in a technical sphere it is permissible to define terms to mean what you want them to mean. The example you give is one such technical use.
Answer: If I had to distinguish between prototypical and prototypal (without referencing a specific domain, such as object-oriented programming), I'd say that prototypal refers to a manner or method involving prototypes, and prototypical applies to  entities (and their behaviors) which are involved in a prototypal scenario.


Can't connect VPN with OpenVPN on Network Manager Ubuntu 14.04 LTS

Question: I would like to connect to my new VPN (HMA) with openVPN and Network Manager on Ubuntu 14.04LTS. I can establish a connection with a VPN server but I can't use Web browsers ("Address not found"). Also I can ping IP addresses but I can't ping domain names.
Comment: @CravateRouge - You have the freedom to post your question and the answer as well. However, posting and accepting an answer to your own question has certain limits where you can refer "[**Can I answer my own question**](http://askubuntu.com/help/self-answer). And not to worry, as we're always here to help/support our users at any time with love & care. :)
Comment: You might want to [edit] your question to explain the exact problem you get when you try to browse from a browser :)
Comment: Browsers I know aren't explicit, they just say "Address not found" or something like that ^^ but you're right I'll add some symptoms that I experienced.
Answer: The issue is DNS settings so you can try this

CHANGING YOUR DNS SETTINGS ON
WINDOWS, MAC, ANDROID, IOS, LINUX

If it didn't work you can modify /etc/resolv.conf and add nameserver "DNSaddress"
But resolv.conf is a dynamic file so to add this line permanently:
sudo nano /etc/resolvconf/resolv.conf.d/tail

and add your DNS servers like this nameserver "DNSadress".
I hope this post could help others.

List item


How is he hiding his pick?

Question:

I've noticed that he's using his thumb to mute, so he's probably not holding his pick in between his index and thumb, which would suggest it's in his palm. Does anyone know this technique, and can explain it? He seems to be able to take his pick out quite quickly.
Comment: Between ring finger & palm?
Comment: When he is tapping with right hand middle and index finger he is holding the pick under his right ring finger between ring finger and palm.  Notice that the ring finger is always curled towards the palm when he is tapping with his other right hand fingers on a 7 string guitar.  Amazing guitarist.
Comment: You may want to skip forward to 2:40 or so...
Comment: @topomorto ok yeah, he seems to be holding it in between his thumb and index at 2:40, but I am almost certain that is not what he is doing at the beginning.
Comment: @Jim Aha, no I was just giving a time hint to others watching the video to a point where you can see him flip it (to save them a minute). You may be right that it's not the same trick!
Answer: As @RockinCowboy pointed out, for most of the tapping sequences he simply tucks the pick into his palm and holds it there with his 3rd finger. Retrieval is simple, as you can see at 0:40, in fact at around 3:10 you can see very clearly how he just uses his 3rd finger.
There is a sequence around 1:35 where he holds the pick normally and taps using his 3rd finger - but this looks to be because of the sequence immediately prior.
(As an aside - he isn't actually muting with his right thumb. For most of this track he is using it to position his tapping fingers accurately.)

How is he hiding his pick?


Unit testing for write_text method in C# visual studio 2008?

Question: Is there a way to do unit test for module which does not return anything. My function is a void function and it formats the output and write it to a text file.
 I am not sure how do unit testing for such a method.
Any suggestions...
Thanks
Answer: Pass in the dependency!
Instead of directly writing to a file, have your method write to a stream instead.
This abstraction allows you to execute the method on a file stream for normal program operation, but for your unit tests you could pass in a memory stream and then verify that the appropriate text has been written to the stream after the method call.
Alternatively you could separate writing to the stream or file from preparing the actual content to write. This would allow you to assert that the correct content is prepared independently from actually writing it out.
Comment: Do you have any example how to d that? I am new to C# and don't know about "Pass in dependency".
Answer: You can write a test checking the existence and the format of a predefined value in the output file.


How do you show long names in mobile apps?

Question: I'm working with a client that has an existing user base with some very long names and usernames. (i.e. Xx_fakenamehere_xX)  I don't want to truncate them (they're already truncated in the current version) so I'm trying to find out ways to solve this.
Answer: I can think of a number of strategies. Also look at Should a username be truncated? and Truncating long text labels - Best Practices? for some related ideas.
Wrap. If the name exceeds a certain length you could switch to a smaller font and wrap the name. Will not save you in all cases though, since you've only got about two lines of space in that header and some people have really long names.
Scale. Decrease the font-size to make the name fit. It's probably best to have a minimum scale though. You could combine this with the wrap strategy. Makes for some complicated code though.
First name, possibly with first letter of last name. If the displayed name is that of the user, this would be sufficient. It is probably not sufficient to identify other users in the system. You also need a way (tooltip perhaps) to display the full name. You also need to know what part of the name constitutes the first name (eg. if you only ever asked for a "name" and not "first name, last name" I don't think you can split the name up correctly).
Truncate. At some point, looking at where and how the name is displayed, you're just going to have to truncate. Make sure you do it right and put an ellipsis at the end and not just cut the last character in half.
Answer: Truncate, but display the complete name on hover using for example an overlay superimposed over the original.
My error: this question is about mobile that has no hover! (thanks @Sheff) And touching the truncated name is not an option, because the finger would obscure the expanded name most of the times.
I'd try a button below the names column (I'm assuming there is one such column) that, when touched and only while touched, would enlarge the names column width allowing the names to be seen in full.
The user might want to see the names in the list, but maybe not the full name all the time.
Also, account for cultural differences when defining the with and the font size of the user names column. Maybe in your culture the names are short and monosyllabic, like "John Doe", while other cultures like in Spain or Colombia have double first names and double family names.
Comment: The question specifically mentions mobile which has no standard hover interaction.
Answer: Other than the obvious solution of suggesting a smaller font size to ensure the name fits in, a suggested design you can go with is to show the first name with a dropdown next the user name which on expansion shows the full name and any other details you would care to show.

download bmml source – Wireframes created with Balsamiq Mockups
An example of a site which does this is Gmail (though I admit they do show the email id signed in)
Comment: Just curious. Why did you blur your email address but leave it still readable (well ok, distinguishable)? Are robots doing OCR now as well? On all images?
Comment: Haha I think I didnt do a good job of it :)
Comment: hmm, you just put an extra step in the process for anyone who loves this answer and would like to contact you about work ...
Answer: Not a solution but a couple of things to consider that may help you define the solution:
1) Typical length
Do you have any idea about the names that will be in the system? You said its an existing user base so if you analyse this data it may give some insight? If you know the "typical" length it could give you a better idea of how to handle the issue.
For example if I can often only see peoples first name, and there are a lot of people with the same first name then its a big issue
2) Use cases
How are people using the name information, are there a lot of names listed next to each other? Or is it like a profile name, 1 per page. Are there other unique identifiers or is name integral to completing whatever the task is?


What is the exact definition of undirected graph, directed graph, unidirectional graph, bidirectional graph?

Question: I've read many literature papers, but I still cannot understand their exact formalization definitions. Is their any difference among them or is there any relationship among them?
Comment: Doesn't Wikipedia tell you all of this?
Comment: The paper you are reading will often give a definition for what a term precisely means in the context of that paper.
Answer: I've only ever heard of directed and undirected graphs, whose definitions can be found in Wikipedia. Rudimentary search reveals the following interpretations of unidirectional and bidirectional graphs; it is possible that these terms also have different interpretations:

A unidirectional graph is another name for an undirected graph.
A bidirectional graph is a directed graph obtained from an undirected graph by replacing each edge $\{x,y\}$ by a pair of edges $(x,y),(y,x)$.
Answer: Well I'll try giving simple definitions, let's hope you get the idea with that:
Directed graphs: Are basically those graphs that have edges with directional arrows marked on them. They show which direction to move between the two vertices they connect.
Undirected graphs: Are just the opposite of directed graphs, as in the edges do not have any associated directional arrows with them.
Unidirectional Graph: Is a graph with edges which are directed only in one direction, like in the case of a directed graph.
Bidirectional Graph: Is a graph in which each edge is given an independent orientation (or direction, or arrow) at each end. Thus, there are three kinds of bidirected edges: those where the arrows point outward, towards the vertices, at both ends; those where both arrows point inward, away from the vertices; and those in which one arrow points away from its vertex and towards the opposite end, while the other arrow points in the same direction as the first, away from the opposite end and towards its own vertex.
Comment: Wikipedia calls your bidirectional graphs *bidirected*.


Will Stack Exchange support SPDY?

Question: SPDY is an alternative protocol to HTTP that is specifically designed to reduce page load times. I heard that Google Chrome, Firefox, and Internet Explorer 11 support it. Google uses it to load pages. Will Stack Exchange sites start supporting it? More info: http://isspdyenabled.com/ (should give YES result on Chrome, Firefox, and Internet Explorer 11 (in Windows 8.1, not Windows 7))
Comment: @RichardJ.RossIII - Hardly the issue here, though true enough. We use IIS on Windows - until Windows supports SPDY natively, we most probably won't. See: http://stackoverflow.com/questions/6210557/spdy-module-for-iis7
Comment: @Oded sure thing, just don't let it become 6-8 weeks! ;)
Comment: @Oded why not make it official response with [meta-tag:status-deferred] then? :)
Comment: @ShaWizDowArd - It is more of an educated guess than an official response - need to talk it over with other team members before making it "official".
Comment: @Oded I guess Nick knows more, can you Summon him? :-)
Comment: The standard SE policy is they don't support things that aren't official standards, same deal with the numerous requests for different HTTP status codes that have popped up.
Comment: @ShaWizDowArd - It is possible that some of our infrastructure can (or already does) support spdy - for instance the HAProxy nodes. I just don't know enough to give an authoritative answer without consulting with some of the more ops devs...
Comment: @ShaWizDowArd - Sunday is the weekend for him (and me, actually). I am sure it can wait for Monday. Most of the Western world doesn't work on Yom Rishon ;)
Comment: It's not an "alternative protocol." It's still HTTP, it just modifies how information is sent over the wire.
Answer: Nope, not in the foreseeable future.
Why? Almost all of the gains from SPDY come from many requests on a single connection - it's designed around removing duplication and advances in compression over HTTP by not doing extra work, mainly:

Spinning up multiple TCP connections (one shared, rather than one per request)

avoiding TCP slow start as a result

Compressing things like headers (including cookies) sent every request (we can only send them once too!)

All of this is good stuff, it's awesome...if you have multiple requests.  However, you don't send multiple requests to us on a page load, we do our best to make sure of that.  You make a single request to us on almost every page, then additional requests to our CDN, but not to us.  Take a look at this page, what do you get from our data center?  The HTML for the page then in the background, later a token that we use to track view counts on questions (but you don't see or feel the load time on this).
If HAProxy implements SPDY support/batching later (not pass through) we'll of course take a look, but as it stands now the protocol itself doesn't really gain us much except another layer to debug and very little to no more performance for our users.  Given that, it's just not a win.
Also, practically speaking SPDY requires SSL (technically it's not required, I'm aware), which we haven't deployed yet.  We're working with the HAProxy author on a bug that causes our load balancer to overload and stop responding suddenly - let's just go ahead and agree it's best we not deploy that until we find the cause.  After that's solved we'll have more to talk about with respect to what's going default SSL - the latency penalty is pretty severe, especially for our non-US users.
When you're as big as google and you're not using a CDN then SPDY makes a lot more sense, not so much for us...at least not yet.
Comment: So, if all of Stack Exchange content came from only the Stack Exchange servers and not from a CDN, SPDY would be implemented earlier?
Comment: @gparyani Not earlier, more of at all...that's when it would make sense.  But that would mean slower content for everyone outside the eastern US, plus we couldn't handle the bandwidth of serving our own static content at peak traffic after a build anymore I'm pretty sure.  In either case that scenario would only result in a slower page load for most of our users.
Comment: So you mean that it would bias those living in eastern U.S.?
Comment: In the end, would this be [meta-tag:status-deferred] or [meta-tag:status-declined]?
Comment: @gparyani It biases towards those by sheer speed of light, yes.  For status: [status-declined] at the moment since it just doesn't make sense, but our architecture shifts to meet our needs all the time.  Will we have data centers all over the world this time next year? Maybe.  We'll be discussing that in a few weeks when the dev and sysadmins teams head to NYC for a meetup.
Comment: So, what were the results of the meetup?
Comment: @gparyani we may do away with the CDN, kinda, sorta :) A global local proxy where SPDY makes sense and moves termination local for example.  We'll be actually putting some changes to the test in a few months - busy wrapping up other things right now.
Comment: So, has the HAProxy bug been sorted out yet?
Comment: @gparyani yep - you can access all our primary domains on SSL now, we'll be working on the mixed content in the coming weeks.  SQL upgrade this weekend is the focus at the moment.
Comment: You should update the answer then.
Comment: MaxCDN just added support for SPDY... http://blog.maxcdn.com/now-serving-spdy-3-1/ You guys are still using them as your CDN provider, right?
Comment: @SteveWortham We are not, we are using CloudFlare which is more than a CDN and actually lets us use SPDY for acceleration when we begin proxying through them (they've had SPDY support for some time).

Will Stack Exchange support SPDY?


PHP WebService Call from other language

Question: If webservices created using PHP,Is that web service can be call from any other language like Intersystems Cache Or GTM..etc.and call from anywhere?
Answer: If it is a true web service, it can been consumed by any language that can access it.
Web services are about inter operating between languages and platform, so they can be consumed by a wide range of those.

PHP WebService Call from other language


how to create a startup script for minecraft

Question: I own a vps in which I run various servers from.
One of those things is a Minecraft server. Recently I also installed a teamspeak server following a tutorial. This server however started up automatically on boot and would run even if I did not have an ssh window open running the process. I then attempted to create a similar start up script for my Minecraft server. However I could not do it successfully. I looked up the formatting codes and instructions on the official help page, but when I boot up the Minecraft server it does not auto start like the team speak server. Note: I know screen is an option however I prefer not to use it. The startupscript for team speak was placed in the init.d folder and now runs as long as the server is up despite if I am connected to it or not.
Answer: I've had the same issue when I was setting up a minecraft server on Debian. The following advice should apply to Ubuntu as well.
There are several scripts available. The minecraft wiki has a list at the bottom linking to some popular scripts. However, I'd personally recommend Athenus' minecraft init script, which also contains some nice features like world backup and log rotation. It uses screen like many other scripts, but to be honest I think that's a good thing, because that way you can always attach to the console of your server if you ever need it.
Alternatively, you can write your own init script, by using something like this as a template. You just need to tweak the start and stop procedures, which shouldn't be that difficult if you have a bit of experience with the terminal.


Custom permission: All but site collection feature" & "manage site feature"

Question: I have sharepoint group with custom permission.
I want this group to all access on site like admin except for "site collection feature" & "manage site feature". Is this possible?
Which access I have to uncheck from custom permission (initial admin access is granted)
Comment: Site collection features can only be managed by site collection administrators and if you are giving that access then you can't control that with permissions. So your question is really: "what permission level can I use to prevent a user from activating/deactivating features?"
Answer: What you're looking for is called Permission Levels.
Permission Levels allows you to specify on a granular level what a user can and cannot do.
Browse to http://YoursiteUrl/_layouts/user.aspx and click on "Permission Levels". Add a new one and select the permissions you want.
You can read more about the subject here: http://office.microsoft.com/en-za/sharepoint-server-help/edit-create-and-delete-permission-levels-HA101805381.aspx
Comment: User already said, he has custom permissions on a group, which states he knows what permission level it :-)
Comment: yes, i am using permission level only.
I have permission level "admin" which is duplicate of full control. Let me know which checkbox I have to uncheck so that user can have everything like full control except "site collection feature" and "manage site feature". User with admin access shoul not manupulate both.


Is it permissible to wear body protection material or gear under the clothing when keeping wickets in cricket?

Question: Can you wear baseball keepers' protective gear under your clothing in cricket?
Comment: Hi, Welcome to Sports Stack Exchange! I really didn't get you clearly. Can you please give more information on what exactly do you asking?
Comment: An image of that material would help us understanding this post..
Answer: AFAIK, yes it is allowed to wear baseball protective gear for cricket.
You are discussing about the protective gears under the clothes in baseball, ie, specifically about the leg-pads.

It looks more or less same as the cricket leg-pads.

Only the wicket-keeper and the fielders in short leg and silly point are allowed to use the leg-pads in cricket, but the leg-pads used by Wicket Keepers in cricket is slightly big and goofy than baseball leg-pads. Since the cricket ball is more hard than baseball. So, that type of pads are preferred  by cricketers. No rules were block them to wear baseball leg-pads.
We can see some of the cricketers using baseball helmets in cricket.
Comment: you have mentioned only wicket keepers can use the leg pads but even fielders who field at short leg use the pads. Are they allowed to use it?
Comment: @suhas, yes the fielders in short leg can wear pads, but those shin pads look very small and wore inside the pants. The legpads worn by Wk is different from Fielders.
Comment: @suhas, edited the answer. And one more thing, the question is specifically about WKs.
Answer: Yes, it is allowed,but after Umpire's consent (according to the law). But under the clothing, I don't think so. Helmets were allowed in a few cases (Dinesh Karthik, McGlashan).
Fielders at forward short leg or any other fielding postion closest to the pitch often wear shin guards(non-cricket gear/generic sports gear).
While, other fielders use a thick layer of bandages/tapes on fingers.
Law 40- Wicket Keeper
Law 41- Fielder


what is cache.cfg file meant for? can we git ignore this file

Question: Why is the magento/downloader/cache.cfg file used for? can I ignore that file in the gitignore file
Answer: Yes it is safe to ignore this in your .gitignore. I normally have the following:
# Ignore downloader cache and configuration files
/downloader/.cache/
/downloader/cache.cfg
/downloader/connect.cfg

As for the cache.cfg file, this contains a gziped, PHP serialized array that contains all the current configuration information for you Magento Connect instance. This is where it stores extension versions.
source: Where does Magento Connect track installed packages and versions?
Answer: It is not safe to ignore cache.cfg if you ever use ./mage upgrade or magento connect to keep track of packages. .gitignore. If you are just rsyncing to a server, then yes, the entire downloader folder can be left behind. But for development, you should share it, just like you would a package.json or a composer.lock.
# Ignore downloader cache, but not cache.cfg
/downloader/.cache/

/downloader/cache.cfg and /downloader/connect.cfg contain configuration details about what version the packages you downloaded are on. While it's easy to recover it, it's better to keep it in version control.
source:
$ ./mage list-installed
Installed package for channel 'community' :
Fooman_SpeedsterAdvanced 0.8.14 beta
Fooman_Common        1.2.8 stable
$ rm downloader/cache.cfg
$ ./mage list-installed
No installed packages


USB SuperDrive Issue

Question: How can I get the USB Super Drive model A1379 to work with my Mac Pro Quad Core computer?  I rebooted my computer, searched for drives - could not locate it on the Apple computer.  Apple support stated bad drive.  I exchanged the drive and started over with reboot.  This operation did not help.
Answer: Unfortunately, the Apple USB SuperDrive will not work with a Mac Pro. Check the System Requirements here.
There are hacks you can try - but it may be better in this case to get a different (3rd party) drive.

USB SuperDrive Issue


Attaching plastic to glass

Question: The people who repaired my wife's car's windshield didn't do a good job, and the little plastic enclosure surrounding the mirror (containing a light and a sunglasses holder) has fallen off. I tried some superglue and it fell off again within a week, presumably because it gets so hot and humid in the car (Georgia summer, parked outside). What's a simple and reliable glue to attach plastic to glass?
Answer: The Glue E6000 is quite strong also but requires a full 24hours to cure and must be untouched in the mean time. It should harden after about 30 mins but it's really best to give it 24hours.  Also its a flexible glue so its less likely to give out from vibration. They also have a "industrial" variant called e6800. I have used it for a few years now and its great. glass is listed but i have no personal experience with that.
Brands like loctite make glue for holding Rear view mirrors to glass so that may be a option.
Hope this helps!
Comment: You really need a glue that's recommended for rear view mirrors due to the extreme heat.+1
Comment: Yup, everything with automotive is harder.
Comment: And any product designed for glueing mirror supports on cars needs *both** surfaces to be super clean and there are products for that as well.
Answer: Frameless fishtanks are held together with 100% silicone. In many cases that's also what's holding the windshield in place on the car, to the best of my recollection. Cure time is moderately long, so the prior suggestion to look at rearview mirror glue is probably going to be easier.
Things need to be very clean (regardless of what type of glue you are using.)
Comment: The product used for car screens never sets solid so the body flexing does not break the glass.

Attaching plastic to glass


Removing sources after building from them

Question: Suppose, we've built some package from sources (configure make install).
May we remove sources directory after successful building? Or it depends? On what, then?
Answer: You don't need anything except the binaries. Those should already be copied to another location by make install. The rest can be removed. If you're unsure make a backup before removal. Remove, test if still working, if still working remove the backup.
Note:
 As ændrük pointed out: Using checkinstall  over make install has the virtue of enabling Ubuntu to track the installation. Later you can revert any changes made using the regular Ubuntu package management.
Answer: If you installed files using make install, the only way to know where they went later on if you want to uninstall them is to inspect the source files. You may want to archive a copy of the source for this purpose.
A better alternative is to use checkinstall instead of make install. This allows Ubuntu's package manager to track each of the installed files in the same way it tracks software from the repositories. When using this method of installation, you don't have to keep any extra files around.
Comment: +1 for checkinstall. Integrated in into my accepted answer so that any who stumbles across will see it.
Answer: Generally once you got your binaries installed you can remove the directory containing source code, unless you want to compile them again, possibly with other compilation options.
Sometimes you could find particularly useful to keep the source directory, for example when upgrading Apache.
You can decide what's your best, in my opinion keep the source directory is a good thing. Obviously if you don't have disk space issues.


How to dedicate a CPU to a process

Question: I've tried to search for a solution, but all I found was how to pin processes to CPU using taskset or sched_setaffinity. But it looks like this won't give the process exclusive access to the CPU, i.e., scheduler may assign some other process on this CPU. Is there any way or command by which we can ensure that the CPU is dedicated to the process? With taskset we can make sure a particular process runs only on particular CPU, but I want it to be other way too, where CPU is binded to that process. I've found questions like How to allocate a process specific amount of CPU power? and How to limit a process to one CPU core in Linux? but they got marked as duplicate of How can I set the processor affinity of a process on Linux? which is not what I want.
Comment: If you pin all processes to other cores, your special process will be the olny one to run on that specific core. But that's probably not what you want. Maybe to need to explain your usage. Applications with a high performance task and guaranteed response times hide a core from the OS and run a bare metal process on that core, for example.
Comment: Hmm... Yeah, something like that. I don't have access to the machine. I want everything to happen automatically with, maybe a shell script or c code of the process
Answer: You Need to exclude one CPU from the Overall scheduling, afterwards you can assign the process to it via
taskset

as you already found out. To exclude a CPU, add the boot Parameter
isolcpus=N

The Number (N) is 0-based.
Comment: Hey, thank you very much. Just a question. Is there any way to achieve this without having to reboot the system? At least something that'll act like this if not being able to completely isolate the core. Thank you.
Comment: Thank you very much for the answer, I think it'll work. What is N? I didn't understand what you wrote. I'm really sorry.
Comment: N is a number from 0 to (number-of-CPUs  -1)
Answer: On systems running systemd you can also configure this in the systemd configuration. Assuming that your system has 4 cores you can add
[Manager]
CPUAffinity=0-2

to /etc/systemd/system.conf to ensure systemd (PID 1) will run on the first three CPUs. By default processes started directly or indirectly by systemd (which is true for all processes) will inherit this setting so the 4th CPU (number 3) will not be used. Just add
[Service]
CPUAffinity=3

to the unit file of the service which you want to run on the 4th core. An advantage of this approach is that you can tweak other real-time related settings like LimitMEMLOCK or LimitRTPRIO in the same spot - no need to fiddle with a bunch of different tools.
Note: You need to reboot your system for systemd to pick up the first change. If you only modified the service configuration restarting the affected service is sufficient:
systemctl daemon-reload
systemctl restart my-service.service

How to dedicate a CPU to a process


arachin: dependance on age and sex

Question: Why is the erech (Vayikra 27:1–8) of a woman less than that of a man? And why does erech depend on age? Sources, please.
Answer: Rabbi Samson Raphael Hirsch's approach, if I recall correctly, is that the number 3 represents the family (father+mother+child), and an additional 2 represents the community. Men are obligated to be involved in both, whereas women are only obligated in the former.
Hence:

mature female = 10 [= completion] x (3 [=family]) = 30 shekels
mature male = 10 [= completion] x ( 3 [=family] + 2 [=community]) = 50 shekels
toddler girl, proportional fraction of adult duties = 3 shekels
toddler boy, proportional fraction of adult duties = 3 + 2 = 5 shekels
young female, working towards completion (10) in the family realm = 10 shekels
young male, working towards completion (10) in both family and public realms (x2) = 20 shekels

(Note that the Torah's stage of "working towards completion" is ages 5 to 20, or 15 years. If we split that in half, we get two stages: 5--12.5, and 12.5--20. That fits well with the concept of bar/bat mitzvah -- half that time is maturing without the technical obligation, and half the time with.)

retired female, back to her prior state of responsibilities = 10 shekels
retired male, given a reduced role of communal responsibilities = 10 (family) + 1/2 * 10 (community) = 15 shekels

The Gemara does observe that retirement age proportionately devaluates a man more than a woman, hence the Talmudic saying:

An older lady in the house is a treasure; an older man in the house is a waste of space.

Which sounds similar to the way one lady described having her retired husband home (I believe this is attributed to the Cosby show):

It's like having a grand piano sitting in your kitchen. It looks good, but it's always getting in the way!
Answer: I don't have a source to cite, but historically speaking, since the ancient world revolved entirely around how to continue living, i.e. earning enough money to feed yourself and your family, and since women didn't need to provide income for the family like the men had to, therefore the monetary value of a working man was worth more than that of women, children, and the old. He had more working potential.
Comment: True, this probably would be connected to the average price of a slave of that age and gender.

arachin: dependance on age and sex


Coupling time series information from sources with multiple spatial resolutions/scales

Question: I have many satellite raster images available from different sensors. From these, the coarser ones have a very abundant temporal resolution. The medium resolution rasters tend to have less acquisition dates but still some degree of information is available. The finer resolution ones have a very low temporal resolution, spanning from 2 to 6 observed dates in under two years. I was wondering if anyone knows of any efforts to study this type of multi-scale time series in any way? I would be interested in predicting future values at the finer scales using the information available from the coarser ones. It makes sense to me that the data must be related (yes the images cover the same regions) but I have no idea how to start coupling this information in a predictive model.
Answer: Spatial Domain:
It seems more like an image processing problem to me. Clustering methods might help but which metric (distance, variance,discontiguity...) and which algorithm (k-means, mean-shift, EM...) is best fit in your case is determined by your image topology and features you are going to use. You may implement the image binning on medium and fine rasters. Then try different clustering techniques to see which one gives you the overall best segmentation accuracy compared with your original medium/fine rasters. Some pre-processing strategies in order to find the scale space hierarchy might help. There is one hierarchy segmentation algorithm shown in Chapter 3 of this report in which you
(1) Build a scale space;
(2) Find the extrema and saddles at every scale level;
(3) Link each critical point at a certain scale level to its corresponding location at the next scale level, and find the critical paths;
(4) Scale space hierarchy determination based on the iso-intensity surface searching.
For the clustering methods that the random initialization is required, such as k-means, you can use the found hierarchy as the initial clusters and centroid for further clustering. Besides, depending on the characters of your image, you may also want to add more features (such as texture changes, other space information than RGB space, etc) in clustering algorithms.
Temporal Domain
Now you have the images with different time scale but the same resolution (hopefully). If your prediction job is estimate the movement of some of the continent, storms, or precipitation, you may try motion estimation with Kalman filter. The motion for each pixel can be weighted inside the corresponding region(cluster) based on its metric compared with the centroid of the region.  You can use neural network for short-term time sequence forecasting (chapter 3 in this thesis). And since Kalman filter is simply a method for implementing Bayes rule, the maximum likelihood can be applied for state estimation. State-estimation procedures can be implemented recursively. The posterior from the previous time step is run through the dynamics model and becomes the new prior for the current time
step. Then this prior can be converted into a new posterior by using the current observation. As a result, iterative parameter re-estimation procedures such as EM can be used to learn the parameters in Kalman filter. Chapter 6 of the same thesis, and the study on Kalman smoothing both include more details on the parameters learning with EM.
Answer: You should look into the literature for super-resolution. This area typically solves the problem of taking in multiple coarse resolution images to create one high resolution image by borrowing strength across multiple images effectively.
I've listed some relevant literature that should be a good starting point.
My favorite approach here uses nonlocal means. This involves splitting all the images up into patches of $5x5$ or $7x7$ pixels, creating better estimates of pixels in the finer resolution image using a weighted combination of pixels in the coarser images.
References
Elad, Michael, and Arie Feuer. "Restoration of a single superresolution image from several blurred, noisy, and undersampled measured images." Image Processing, IEEE Transactions on 6.12 (1997): 1646-1658.
Park, Sung Cheol, Min Kyu Park, and Moon Gi Kang. "Super-resolution image reconstruction: a technical overview." Signal Processing Magazine, IEEE 20.3 (2003): 21-36.
Protter, Matan, et al. "Generalizing the nonlocal-means to super-resolution reconstruction." Image Processing, IEEE Transactions on 18.1 (2009): 36-51.


How to restore the default toolbox windows in GIMP?

Question: I have recently installed GIMP 2.8.6 on Ubuntu 14.04 LTS 64-bit and for the first time when I opened it, two windows along with the main window were available, but now I can only see a single main window. How can I bring those default windows back?
Comment: In the menu there is an option Windows/Single Window mode. Turn that off.
Comment: I have also had the tools disappear, especially when working with email attachments other docs. A stray press of the 'Tab' key makes the tools disappear/re-appear.
Answer: Since you recently installed GIMP and closed the Toolbox window, I would suggest to reset your window preferences because it would also restore the dockable dialogs and the Layers windows which is extremly handy when working with GIMP.
Navigate through Edit menu → Preferences → Window Management → and click the button for Reset Saved Window Positions to Default Values. Then click Ok to close the Preferences dialog and restart GIMP.

I would also suggest to enable the single-window mode so that all these windows would be docked inside the GIMP's main window and ease the workflow when working with it. Enable it through Windows menu → Single-Window Mode.
Comment: @Glutanimate See this question: [How do I create highlights on a screenshot?](http://askubuntu.com/questions/61104/how-do-i-create-highlights-on-a-screenshot) (particularly, the answer given by Takkat).
Comment: Unrelated to the question at hand but may I ask how you did that screenshot highlight? It's really neat and I'd love to use it in the future.
Comment: When I switched to the single-window mode, all of the docks was at right, but I wanted to be the toolbox at one side and the layers and other at the other side. I have not succeded without reset to the default value. I like single-window mode. Thank you for your answer.
Comment: This is terrible advice. I just lost a year's worth of settings trying to restore a single dialog. It doesn't even answer the question, it just assumes that the window OP wants is visible in the factory default.
Answer: To open a new Toolbox, just hit Ctrl+b.
Comment: this is the result, simple, quick and reliable answer. Btw, how to get there without keyboard shortcut?
Comment: Works like a charm.
Comment: This works, but I can not do it on GUI?
Answer: rm -r ~/.gimp-2.8

When gimp starts again it regenerates this directory, and you'll get gimp fresh and clean :)
Comment: But this will remove ALL of your GIMP config
Comment: true. but the context is that you have a fresh gimp installation and you are not yet familiar with it. when I reset my gimp configuration I was still unable to use it properly until I deleted the init directory
Comment: Genious! Saved me a bunch of time.
Comment: Better to just rename it, so 1) Gimp creates a new one and 2) you can copy stuff (brushes, patterns... ) from the old one.
Comment: I believe the relevant file is `.gimp-2.8/sessionrc`, so one could just move that one to avoid losing everything else, and a fresh one will be created. And of course, it's a better idea to keep it as a backup/reference instead of deleting it completely.
Answer: For GIMP 2.10, either:

Click TAB, or
Windows menu → untick 'Hide Docks'
Answer: I have also had the tools disappear, especially when working with email attachments other docs.  A stray press of the Tab key makes the tools disappear/re-appear.
Comment: The TAB key works in GIMP 2.10.30 ,flatpak, on kubuntu 22.04 LTS
Answer: In increasing order of destructive power:

Just hit the Tab key (or use Windows>Hide docks), this toggles the visibility of existing dialogs
See if the dock is still listed in Windows>Recently closed docks>... and reopen it
Windows>Dockable dialogs>Toolbox to get a new one (or reopen the hidden one if it exists)
For the intrepid: edit the sessionrc file in your Gimp profile with a text editor and check the coordinates of the missing dock/dialog, it could be set off-screen (for instance if you used a second screen in the past). If so fix the coordinates. If you break things, see the next two steps.
Edit>Preferences>Windows management>Reset saved windows positions to default values
Erase the sessionrc file in your Gimp profile (this is normally the same as the previous item)
Erase/rename your Gimp profile to make Gimp recreate an all-defaults one. If you rename it you can later copy useful things (brushes, gradients and other assets you added yourself) from the old profile to the new. But this is pretty much the nuclear option, rarely useful for just a missing dialog.


SSL handshake failure modes

Question: In SSL if the handshake is not successful, does it always end with a handshake alert?
Or are there other ways to finish the SSL connection (acceptable by standard).
I am asking this, because in an HTTPS server configured to require client authentication, if the client does not send a certificate, I see (via network packets) a TLS Finished message from server to client; I was expecting an alert.
Comment: which web server is that?
Comment: @john Heh - I just edited out the tag "iis", so I guess that is the one Jim used, but it didn't seem relevant to the question, especially given Thomas' response.
Comment: @nealmcb: I was about to answer when I saw Thomas' response. The reason I asked was exactly as Thomas says, some web servers prefer to first create the connection and then drop it, instead of doing that at the handshake time. IIS is one of them.
Comment: @nealmcb I think knowing which server is used is useful, because IIS seems to have a different interpretation of the word "require" than Apache Httpd. This being said, it's a more general question, so the tag might have been too specific indeed.
Comment: I observed this in IIS 7.0
Answer: A SSL/TLS connection must always end with an alert message of some kind: a connection which is broken (e.g. the underlying TCP socket is closed) without an alert is said to be improperly terminated. The alert message for a normal termination is close_notify.
The handshake is only a part of the connection; a handshake occurs at the start and subsequent handshakes can be played on the same connection. The handshake is usually where errors occur, triggering alert messages, but a fatal alert message does not end only the handshake: it closes the whole connection.
In the case of a server requesting client authentication, the client may respond by sending a certificate and computing a signature; however, this is optional. The client is allowed not to honor the request. The server then chooses what to do. The server may reject the client right away, through an alert message which closes the connection. The server may also decide to continue, and handle the lack of client authentication at another level. A server which sends a Finished message certainly chooses to continue; possibly, the server may decide to report the error as applicative data within the tunnel (e.g., for a HTTPS server, send an HTTP error message once the handshake is finished).
See RFC 2246, section 7.4.6 for details:
   This is the first message the client can send after receiving a
   server hello done message. This message is only sent if the
   server requests a certificate. If no suitable certificate is
   available, the client should send a certificate message
   containing no certificates. If client authentication is required
   by the server for the handshake to continue, it may respond with
   a fatal handshake failure alert.

→ emphasis on "may".
Comment: I see.The only thing to note is that IIS redirects to a web page saying:"403 - Forbidden: Access is denied" and does not specify about certificate failure
Answer: The section on client certificates in the TLS 1.0 specification (RFC 2246) says this:

If no suitable certificate is
available, the client should send a
certificate message containing no
certificates. If client authentication
is required by the server for the
handshake to continue, it may respond
with a fatal handshake failure alert.

The fact that it may respond with a fatal alert doesn't mean that it has to.
You've tagged your question with IIS, but here is a bit of background about other servers.
In Apache Httpd, there are three settings for requesting a client certificate: none, optional and required (and optional_no_ca if you want to disable the certificate verification there).
When the server is configured with optional, when the client doesn't present a certificate, the handshake will still proceed. When the server is configured with required, if there's no client certificate, there will be a fatal handshake failure alert. Java's SSLEngine implements these settings with setWantClientAuth and setNeedClientAuth.
Note that proceeding with the handshake doesn't mean that the server will grant access to the resource or authorize the execution of the request.
The big downside of the fatal handshake failure alert behaviour is that it closes the connection abruptly. At best, it will appear as a "connection closed - handshake failure" message (or something similar) in the browser. No HTTP exchange will have taken place at all, so there is no opportunity to send an HTTP status code and/or an accompanying web page to describe the problem.
From a usability point of view, this can be very confusing, especially for users who are not necessarily familiar with client certificates (there is often a certain learning curve simply for dealing with certificates). For this reason, many servers only require optional client-certificate authentication, so as to be able to send an explanation if authorization is denied.
I must admit I'm not entirely familiar with the settings in IIS, but the documentation seems to suggest there are three options too:

Select Ignore if you do not want to
accept a client certificate even if a
client presents one.
Select Accept to accept client
certificates.
Select Require to require client
certificates. To use Require Client
Certificates, you must enable Require
SSL.

Another document suggests there is an HTTP status code and error message for failing to provide a required certificate: "403.7 Forbidden: Client certificate required".
The fact that there is an HTTP status code for this case implies that it's not a case that causes a handshake failure (otherwise the connection wouldn't be established to send HTTP messages at all). This implies that the "require" mode of IIS behaves like the "optional" mode of Apache Httpd as far as the TLS handshake is concerned, that is, not presenting a client certificate doesn't cause a fatal alert (authorization afterwards is a different matter, of course).
I'm not sure what "ignore" and "accept" are for, then. In SSL/TLS, only the server can request a certificate, by sending a CertificateRequest message. If the server doesn't send this message, the client will simply never send its certificate, again, from RFC 2246:

7.4.6. Client certificate
When this message will be sent:
This is the first message the client can send after receiving a
server hello done message. This message is only sent if the
server requests a certificate.

My guess is that they mean "ignore"/"accept" in terms of account mapping or authorization, further down the line.
EDIT.
As far as I remember, by default, IIS always negotiates client-certificates using re-negotiation: a first handshake is successful, without any client-certificate request, but then, a second handshake is triggered.
This means that you wouldn't be able to see the client-certificate exchange by looking at the packets, since this second handshake would be done within the encrypted session (you could see it with Wireshark in some cases, it it's configured with the server's private key and it supports the cipher suite).
You can configure the client-certificate negotiation to be done within the initial handshake using the clientcertnegotiation=enable option of netsh (which refers to the initial handshake).
Comment: I think what you say explains what I see.The only thing to note is that IIS redirects to a web page saying:"403 - Forbidden: Access is denied" and does not specify about certificate failure
Answer: I will take an example from OpenSSL, which is used by Apache.
There is a mode flag, called SSL_VERIFY_PEER which when set on the server, it will ask for a client certificate at the handshake. The client is free to send it or not.
Then the behavior of the server, depends on another flag:
SSL_VERIFY_FAIL_IF_NO_PEER_CERT
Which is explained as follows

Server mode: if the client did not
  return a certificate, the TLS/SSL
  handshake is immediately terminated
  with a ``handshake failure'' alert.
  This flag must be used together with
  SSL_VERIFY_PEER.

If this flag is not set, no alert is created and the handshake goes on as normal and the server has to check for the certificate afterwards and close the connection if necessary.
EDIT: More information about similar configuration options in IIS 7.0:
https://www.iis.net/ConfigReference/system.webServer/security/access
It seems that there is an sslFlags attribute which can be one of the following

None. This default setting disables SSL for the site or application.
Ssl. The site or application requires SSL.
SslNegotiateCert. The site or application accepts client certificates for authentication.
SslRequireCert. The site or application requires client certificates for authentication.
Ssl128. The site or application requires 128-bit SSL certificate encryption.

I imagine that the behaviour you notice happens because the SslNegotiateCert is configured instead of SslRequireCert.

SSL handshake failure modes


What is ipo issue size and how they decide ipo issue size

Question: What is IPO issue size?
How they decide IPO issue size? I am asking about IPO issue size like 5000 cr. How they decide this size and what can be maximum IPO issue size? Not IPO share price.
Answer: US centric answer:
An investment bank is hired to determine the value of the company.  The IB looks at the inherent business as well as industry comparisons, growth prospects, etc.
After performing this initial valuation, later on in the process the IB does a roadshow where they travel from city to city, giving presentations to large investors (institutional, fund managers, and hedge funds) as well as analysts.
If the roadshow is successful, it generates demand for the IPO.  The greater the demand, the larger the IPO can be.
Answer: If you are talking about the number of shares issued, that is completely determined by the investment bank as Bob Baerker stated. First, the amount of money to be raised is determined by the investment bank. Then, the number of shares issued is determined to be at a level that enough investors would be able to purchase them. Usually, an IPO starts with a share price around $20-$100. To determine the number of shares, simply divide the amount of capital looking to be raised by the proposed initial share price and that gives you how many shares will be issued.


A node can publish any block at any time. How? How to publish?

Question: Can anyone tell me what to do to publish if I mined a block
Answer: Let's assume that you are solo-mining.
If you are a miner you need to run a Bitcoin Full-Node for example Bitcoin Core. If you do this you are a full part of the Bitcoin network.
If you mine a block, you do the following steps:

Putting transaction together and verify them
Doing the Proof-of-Work (Calculating the nounce until the first characters are zeros).
Adding stuff like coinbase and timestamps
Profit from the reward and transaction fees

If this is done you broadcast the block to all nodes in the network the same way as broadcast a transaction. This means that all nodes are receiving this block. They are also checking it like if your block matches the difficulty and if the transaction are valid. Then they are adding it to their own local copy of the blockchain.
The nodes are broadcasting the blocks and transactions under each other. That's how peer to peer work. You should take a look at this
Answer: To actually publish the block onto the Bitcoin network, you can use the bitcoin-cli command submitblock. You would have to serialize all the data in the block into hex format first.


Installing Canon LBP6000 in Ubuntu 12.04

Question: With the release of Ubuntu 14.04, this question may not be relevant any more. This one (Making Canon LBP6000 printer work under Ubuntu 14.04 64-bit) might be more helpful.

This is really frustrating. I am trying to install LBP6000 in Ubuntu 12.04 without any success.
(Well, I had success about a week back when I first bought the printer and finally printed pages after a struggle of several hours. Then today it suddenly stopped working and I uninstalled everything and started from scratch. Now, I seem to have lost the way.)
My steps

Downloaded the latest Canon driver from Canon site. File Linux_CAPT_PrinterDriver_V240_uk_EN.tar.gz
Got the radu script (http://radu.cotescu.com/how-to-install-canon-lbp-printers-in-ubuntu/)
Changed the /etc/modprobe.d/blacklist-cups-usblp.conf file as instructed in,
Official Documentation. (See the section Ubuntu 12.04 Install).  Now this file looks like,
# cups talks to the raw USB devices, so we need to blacklist usblp to avoid
# grabbing them
# blacklist usblp

Rebooted my machine
Changed the port in radu script to 59787 as instructed in the link at step 3. (Again see the section Ubuntu 12.04 Install, or see the comment at How to Install Canon LBP Printers in Ubuntu.
Also put the latest deb files from step 1 in the appropriate directory of this script.
Ran the radu script. A printer, LBP6000 got added. Not two printers, one to be disabled, as appeared in the message on the terminal after running the script.
sudo /etc/init.d/ccpd status shows,
Canon Printer Daemon for CUPS: ccpd: 3142 3139

Results
The printer does not print. Printer state (from System Setting->Printing, or at cups http interface localhost:631/printers/LBP6000) goes from Idle to Processing, a job appears in print queue, and then the job disappears and the printer state goes back to Idle. The actual printer does not even blink.

Diagnostics (got help from the link in step 3, Troubleshooting)

captstatusui -P LBP6000 shows communication error
lsmod | grep usblp did not show anything. After running, sudo modprobe usblp, shows
usblp                  17885  0

However, ls -l /dev/usb/lp0 gives,
ls: cannot access /dev/usb/lp0: No such file or directory
/var/ccpd did not exist, created,
sudo mkdir /var/ccpd
sudo mkfifo /var/ccpd/fifo0
sudo chown -R lp:lp /var/ccpd

Any suggestion will be appreciated. Do not know what to do.
Answer: This may sound odd but has worked for me - "generically" ie not that specific printer.
Your steps seem sound.. Go through them again ie.. purge the driver(s).
Re-install this time WITHOUT the printer plugged in.
reboot or log in/out
Connect printer and try to print.
Good Luck - Mal
Comment: The problem is now solved. All that was missing was to turn the printer off and then on again. So odd for a USB device.
Comment: I find that now I need to run this script at every boot before the printer prints,
#!/bin/bash

pkill -9 -x ccpd

pkill -9 -x captmoncnabc

/etc/init.d/ccpd start

/etc/init.d/ccpd status
Answer: Operates as follows:
Install gs-esp_8.71.dfsg.2-0ubuntu7_all.deb
Then download raducotescu-CanonCAPTdriver-release-2.4-0-gc8ea9f9
Unpack and install
sudo. / canonLBP_install.sh LBP6000

Answer: Just something you need to mention for the LBP6000 with radu script:

If you install the printer x86 with radu script, everything will be ok. But you cannot print (the printing job will be held for a while then, nothing happens).
To fix this problem (it took me several days for figure out what happened), you please install the driver from the Canon side first, for the capt & common package from here:

http://www.canon.co.uk/support/consumer_products/products/printers/laser/i-sensys_lbp6000.aspx?type=download
After that, install the radu script:
http://radu.cotescu.com/how-to-install-canon-lbp-printers-in-ubuntu/
It works for me now.


Can we add the synonym [kanojo-okarishimasu] to the tag [rent-a-girlfriend]?

Question: The tag rent-a-girlfriend for the series "Rent-A-Girlfriend" currently has no synonym. So, can we add a synonym using the Japanese title "Kanojo, Okarishimasu", namely kanojo-okarishimasu? I think this would be in line with the current policy on tagging.
Answer: Done. kanojo-okarishimasu is now a synonym of rent-a-girlfriend.
Answer: There's no use cases of kanojo-okarishimasu, so why would we synthetically create it?  I don't see that there's a need right now.
Comment: I wouldn't want you to artificially create the tag if the Correct™ one exists already.
Comment: As per my reading of the linked policy, the Japanese title should be a synonym of the English title. Am I mistaken?
Comment: You're probably not but I don't see a reasonable way to synonymize a tag that doesn't exist.
Comment: I was under the impression moderators have some magic powers to take care of this. ;) If it would help, I can create the tag [kanojo-okarishimasu] and shoot off a couple of questions under it. :)
Comment: All right-y. :)


Capacitance and Inductance properties of coaxial transmission lines

Question: I'm interested to understand what affect the capacitance (between cable core and shielding) and the inductance have on a signal transmitting down a coaxial cable.
Comment: Have a look [here](http://en.wikipedia.org/wiki/Transmission_line).
Answer: The equation which answers your questions is that of the characteristic impedance of the transmission line, which arises from both inductance and capacitance: $$Z_0=\sqrt{\frac{R+j\omega L}{G+j\omega C}}$$
For a lossless transmission line this is simply: $$ Z_0 = \sqrt{\frac{L}{C}} $$

You should also check out the Telegrapher's Equations. They are one of the first steps in to transmission lines, a scary and wonderful topic.
Comment: Thank you, I'll check those out.

Do you have any info in more simple terms? such as 'a higher the capacitance would affect the signal propagation in this way..'
Comment: @Jenny_the_Argonian Well, we can see it what it does from the equation for characteristic impedance. For instance, if you hold the inductance constant and increase the capacitance the characteristic impedance will decrease. As for signal propagation, that depends on a lot more, like what the impedance is of the signal source and the load. I can't make an accurate statement about the propagation without knowing more about the system.
Answer: Since the op asked for simple infos:

high C means that higher frequencies get cut before, i.e. the cable act as a low pass filter, the higher the C the lower the corner frequency.
high L means pretty much the same thing, higher frequencies are cut before.

That is because the transmission line is modeled as a second order LP filter (series L, parallel C), so the corner pulsation is \$\omega_0=\frac{1}{\sqrt{LC}}\$.
nb
a transmission line is actually modelled with distributed components, so it's not exactly an LP filter


Does crashing during a test mean you have to scrap the roller coaster?

Question: If I'm testing a roller coaster design and it crashes, will I need to scrap it, like you have to when a finished, running coaster crashes? To put it another way, in the eyes of the game/guests is a roller coaster that crashes during testing different from a coaster crashing "Open"?
Comment: Are we definitely talking about the first RCT game?
Answer: Let's do some science to find out! Here's what I did: I created a new coaster specifically designed to crash. Upon testing, of course, it crashes. When I open it up, nobody wants to ride it because it "isn't safe" (note that if I didn't test it, someone probably would have gotten on).
From there, I made all of the changes necessary to make sure it didn't crash ever again, tested it, and re-opened it. To my surprise, the guests were still convinced the ride was not safe, even though it wasn't designed to blow up this time. From this result, we can conclude that yes, crashes during testing do, in fact, matter. But there are a couple of ways to prevent them, or fix the problem after-the-fact if needed.
If you suspect your coaster might crash during testing, hold your mouse over the "close" button, and watch closely, especially in the section you're concerned with. If it starts to fly off the track, double click the "close" button to stop it. If you're quick enough, you'll close and reset the ride before it starts actually crashing (it doesn't count if things haven't exploded).
If you aren't fast enough, and your design is strictly above-ground, you can save that design, remove the whole thing, and replace it. That way, you won't have to start all over.
If your track did have some underground sections, then it gets complicated, since when you place a saved track, it tries to put the lowest point on the ground. At that point, it might be best to start over.
Comment: It depends on what the game defines on THAT coaster.  Its very likely the entire ride must be deleted, but workarounds are possible depending how the game was designed
Comment: @eyeofthehawks I'll try it, but I doubt this will fix things, given guest's behavior upon other construction. It's possible though.
Comment: Did you attempt to delete the station platform to mitigate the problem?  I dont have access to rct at the moment, but i imagine deleting the station platform, pressing test, getting error cause no platform, then readd it may do somrthing
Answer: Yes, At least in RCT3. If the coaster crashes in build mode, it wont have an impact on the guests.
Comment: The difference being that in RCT3 in build mode when you are testing it, it's just a ghost of the coaster and not the actual thing.  If you test in RCT1/2 or 3 out of build mode it runs with the actual train
Comment: RCT3 != RCT1. This doesn't really apply here


What are the main issues concerning the abstractness of the theory set out in The Sound Pattern of English?

Question: The vowel analysis in Chomsky and Halle's (1968) SPE is said to be overly abstract. What are the main issues phonologists have with this abstractness?
Comment: This is rather off-topic, but *The Art of Computer Programming* is roughly that age, and the first edition is still a good read.
Comment: Phonologists no longer pay much attention to SPE, except in history of linguistics classes for a few days. That's 43 years old; who reads 43-year-old physics or computer science research books?
Comment: I'm surprised by the first comment. As a student of English Language and Linguistics, I've been taught that SPE is one of the most influential publications in Phonological Theory.
Comment: It's where it all started, the first attempt at a Generative Phonology. That makes it a landmark for sure, but doesn't make it readable or useful in modern phonology. The notation is awkward and incomprehensible and the theory obsolete. Ask anyone who's gotten a PhD in phonology within the last decade whether they refer to it frequently. And why not.
Comment: As for Knuth, I'll give you that one, @microtherion. But _Software Tools_, to pick another classic, was written in RatFor and is now useless, except for the text. K&P had to bring out another edition in Pascal. And now that's pretty useless. And linguistics theories change much faster.
Answer: There was a feeling at the time that the distance between underlying and surface forms in their analysis was too great, and there must be some absolute limit on how different the two levels of representation could be (say, measured in number of features changed, or whether underlying feature matrices or sequences of matrices had to be a subset of observed matrices). The attempt to articulate any such formal restrictions was quite unsuccessful. With a bit more rational analysis, we came to understand that the issue was not really about the qualitative distance between representations (a.k.a. abstractness), but rather it was about other methodological assumptions that SPE made.
The primary factors that motivated their abstract analysis were (a) their aesthetic desire for symmetry, (b) the wish to formally connect all possibly related word forms, and (c) the desire (prevalent at the time) to capture every generalization out there, even ones that deserve to roam free. Since their formal theory of rules was extremely device-rich, a lot of things would be possible then, that were deemed to be formally impossible in later developments of phonology. (Note how I say nothing about the current state...).
For instance, they wanted to assume that various and variety have a common root, which led them to a certain abstract analysis of the i ~ ai alternation, and similar facts drawn from word pairs like derive ~ derivative and the ɪ ~ ai alternation led to them positing underlying forms that reflect Chaucerian pronunciation. Then they conclude that the English vowel system really has no underlying diphthongs, except for ɔi, so that makes way for a symmetry argument that "coin" has to be underlyingly /kœ:n/ (because of the rules they set up, that derivation comes essentially for free, and now there are no diphthongs).
SPE was an integrated package deal, and great effort was put into accounting for every little fact without having any exceptions, thus a stress puzzle could force a different and more abstract analysis of [ow] (veto ← /ve:tɔ/, motto ← /mɔto/). In their analysis, [ˈraitʃəs] 'righteous' derives from /rixt-i-ɔs/ and [dʒəˈræf] 'giraffe' from /giræffe/, and so on. Oddly and uncharacteristically, they also note 2 pages later (p. 152) that "giraffe" could also come from /ǰVrāf/ which is only two steps away from saying that the surface form is the same as the underlying form. The general reaction was that there was something wrong, and "abstractness" was blamed.
My position is that blame should be placed not on abstractness, but on gratuitous assumptions about morphology esp. the question of whether historically related forms are to be reduced to common roots and affixes in all cases; on their idealizing assumptions about underlying representations; and on the fact that they were trying to operate without an autonomous theory of acquisition (that is, the structure of grammatical theory was supposed to automatically account for all of acquisition).
Answer: The most relevant-seeming tests for how naive speakers understand the structure of their language concern rhyming in poetry and how words are deliberately distorted in secret languages (such as pig-latin).  These tests do not so far seem to support the SPE analysis.  (You could look at articles by David Stampe and Paul Kiparsky for discussion along these lines.)


I can't access my USB device after mkfs.ntfs command

Question: I had used these commands (as root):
umount /dev/sdb1

After,
mkfs.ntfs /dev/sdb1

It took a long time to format it and I couldn't wait it. Before it finished formatting, I had canceled operation.
After I used my usb device for making copy operations, I couldn't use my usb device.
Actually, Maybe it wasn't about mkfs.ntfs command but there is a truth now:
I can't use my flash drive.
I plugged in my flash drive into my computer which uses linux mint. And I opened "Disks" program on Linux Mint. It is screenshot (after plugging in usb device):

It is another screenshot (before plugging in usb device):

As you see, It says "No media" about /dev/sdb although I plugged in usb device.
There isn't any problem about my OS (Linux Mint). The problem is about my usb device. I can see my other usb devices on Linux Mint.
Have I burnt my usb device ?
How can I solve this problem ?
Edit: After intense desires of our participants , I should add it:
I used these commands (there are commands with outputs below):
LinuxMint linux # mkfs.ntfs /dev/sdb1

Failed to access '/dev/sdb1': No such file or directory
The device doesn't exist; did you specify it correctly?

LinuxMint linux # mkfs.ntfs /dev/sdb

Could not open /dev/sdb: no media

So on, It can't recognize my usb device at all.
Look at fdisk output: Command:
fdisk -l

Output:
Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, toplam 625142448 sektör
Units = sektör of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0007bccb

Device              Start         End     Sectors Size   Type
/dev/sda1            2048   251660287   125829120   83   Linux
/dev/sda2       251660288   541255679   144797696    5   Extended
/dev/sda3 *     541255680   619380679    39062500   83   Linux
/dev/sda4       619380736   625141759     2880512   82   Linux swap / Solaris
/dev/sda5       251662336   335548415    41943040   83   Linux
/dev/sda6       335550464   457369599    60909568   83   Linux
/dev/sda7       457371648   541255679    41942016   83   Linux

Comment: Could you [edit] your question and add the output of `fdisk -l /dev/sdb` (as `root`) with your flash drive plugged in? If it shows a partition, try running `mkfs.ntfs` again...
Comment: There is no any output.
Answer: You started creating a filesystem on your device and cancelled the operation. That left your device with no working file system so, of course, you can't use it.
The good news is that, unless you've done something else you haven't told us about, it should be enough to just plug the device in again and running
sudo mkfs.ntfs /dev/sdb1

This time, let it finish!
Important: before running the command above, make sure that the USB device you want to format is indeed /dev/sdb. That command will destroy any data present in /dev/sdb so if that's not your USB drive, you really don't want to run it.
Comment: I edited my question. Look at it.


How does ignore affect interactions with team mates?

Question: Sometimes I'm forced to ignore someone on my team for some reason.  Can a player I've ignored still see my chat/pings?  Can I see their mini-map pings?
Answer: They can still see everything you say in chat, and all of your minimap pings unless they ignore you as well. You will no longer be able to see their minimap pings.
The commands to ignore someone for a single match is: (entered into chat)
<code>/mute playerName
</code>
To ignore someone permanently:
<code>/ignore playerName
</code>

Sources: http://leagueoflegends.wikia.com/wiki/V18.104.22.168 under 'General' for minimap pings.
http://na.leagueoflegends.com/learn/chat_commands for ignore commands.
Comment: As of the time this question was asked and answered, you could not see their pings, but they could see your chat/pings.  They made a change in Feb 2013, and now you see someone's pings even if you have them muted/ignored.  They tried to compensate for this by adding a "ping limiter" which stops them from pinging more than 3-4 times in a row.  Unfortunately, you still get people who will ping random things 3-4 times rapidly every time they're able to.
Comment: He's not asking about latencey; he's asking about minimap pings.
Comment: Ah, I'm not sure about map pings.
Comment: Personal experience, and I've just cited a source for minimap pings. I wasn't sure about those.


How to distinguish the meaning of "repair" and " fix"

Question: Are both the same? When do we use "fix" and when do we use "repair"
Comment: How do the dictionaries define the two words?
Comment: *Fix* is far broader than *repair*, even in its informal usage. http://www.collinsdictionary.com/dictionary/american-cobuild-learners/fix http://www.wordreference.com/definition/fix
Answer: The differences can be subtle. (We'll ignore the meanings of fix that have nothing to do with repair at all.)
At their closest pairing, the two words mean essentially the same thing, the difference being that repair is an "H" word (part of the "high", or more formal, vocabulary) while fix is an "L" word (part of the "low", or less formal, vocabulary). That's the difference that makes a business offer a "repair service" rather than a "fixing service" (or a "mending service", for that matter) even if the people working there would answer What do you do here? with I fix stuff.
At another level, though, the difference is greater. Repairing is pretty much limited to putting things back to the way they were or restoring them to usefulness. Fixing often goes beyond that to include modifications or improvements. One would never speak of repairing something that is brand-new and in perfect working order (it doesn't need to be repaired), but brand-new shiny things can be fixed in order, for instance, to become useful to someone who has a disability that renders the brand-new shiny thing essentially useless to them in practice even though it would meet their needs in theory. You can fix a system that is working as designed but not working as desired; repairing the same system would imply something like eliminating the work-arounds that people have developed to get around the failings of the system.
Comment: @mplungjan - Sadly, I have seen more than a few "craftsmen" who were, perhaps, not at the top of their game "repair" things in exactly that sort of way. It's about intent, not process.
Comment: i appreciate that.
Comment: Also you can fix the leaking faucet with a spanner, but repair it by taking it apart and replacing the broken sealing