How should swordfish be prepared?

Question: I just purchased one pound of swordfish filet and never cooked swordfish before and have minimal experience cooking fish. Any suggestions on preparation? Also what should I look for while cooking it?
Comment: Swordfish is on the red list of fish to avoid due to over fishing. In the old days I would have rubbed with muscovado (raw brown sugar) and some dried oregano and rosemary, gentle BBQ with the lid on
Answer: I love swordfish grilled with a little olive oil and Montreal steak spice.  All the firm fish are great on the grill.
Firm fish like ahi tuna and swordfish can pretty much be treated like really good steak, just cook them carefully because you want them left on the very-rare side of things.
If you do it in a pan make sure there's hot oil or butter (or both) before you add the fish and don't move it around too much.  If you fuss too much with the fish it will fall apart.
As delicious as swordfish is a lot of the fish on the market isn't being sustainably caught.  Make sure to ask where its coming from.  Most of the US and Canada fisheries are pretty good.
Comment: It is from the US and Canada, I forget where specifically. Whole foods had "wild swordfish steaks" on sale for $11.99 lb, so I had to pull the trigger on it
Comment: all swordfish is wild. I don't think you would want to try keeping one in any form of enclosure...
Answer: Olive oil, salt and pepper and grilled (on a flame broiler or outside Bar-B-Que) to perfection.  Then, when done, squeeze some lemon (or, in my case, lime) on top and enjoy...  Most fishes, I think, taste best with the simple additions, but others will disagree because it's a matter of taste.  One spice mix, therefore, I personally love on any fish, including sword fish is a nice mix I got on Orcas island: chipotle, ancho, cumin, some green herbs (dried) and salt and pepper...
Answer: Ginger+garlic paste+red chilli powder+olive oil+salt+lemon & grill it..
Answer: When caught we normally gut them. stuff with lemon grass & pit roast.

How should swordfish be prepared?


Is there a way to force open a new browser window from MOzilla to IE by Onclick function?

Question: Iam getting new window pop up by using window.open(), but need When i click button in Mozilla browser, a new pop window should open in Internet Explorer, Is it possible......
Answer: What about non-Microsoft operating systems? Internet Explorer is not available on e.g. Linux. As such this is not possible. Executing arbitrary external applications should not be possible, at least not without the user's explicit permission. That would be a serious security risk.
Why do you want to do this? Does you website not render properly on anything other than IE? If that is so, then you may want to improve the HTML/CSS/Javascript to make it more standards/cross-browser compliant.
Of course, you could just ask or advice the user to view your website in IE. Not a fancy solution, but it has been done that way for ages. Firefox has the IE Tab add-on, which allows users to render pages using IE's render engine inside the Firefox GUI. This makes things slightly more convenient, but it's still a manual process which requires the user's explicit consent.

As a side note, something akin to what you want is possible with the combination IE/Google Chrome Frame. If you add the following meta tag in the target page, then IE with Google Chrome Frame installed will use Google's instead of IE's rendering engine (source):
<code><meta http-equiv="X-UA-Compatible" content="chrome=1">
</code>
I am not aware of any other browser/plugin combination with this feature.
Comment: `Does you website not render properly on anything other than IE?`. Please let me know if you know that kind of website :)
Answer: No. Not possible.
Answer: If it was possible to run other applications straight from the web, you would already have tons of malware on your computer. Of course this is impossible and not everyone has Windows.
Answer: It might be possible if you have control over clients PC (like e.g. company network). There are handlers for special urls in Firefox that allow you to open external application. It requires approval from user. I saw such links for Skype or other IM clients. And one another example is mailto: link.
Answer: Well, there are no such compatibilities in DOM, niether there's access necessary for JS to know system capabilities... but I just found this add-on, IE View, that let's you load pages in IE with a right click (using context menu) and mark certain sites to be loaded from IE only.


How can I make an index covering a ts_vector expression and also an integer?

Question: I am using the ruby pg_search gem, where code like this: Food.search("orange") produces a query like this.
SELECT "foods".*
FROM "foods"
INNER JOIN
  (SELECT "foods"."id" AS pg_search_id,
          (ts_rank((to_tsvector('simple', coalesce("foods"."name"::text, ''))), (to_tsquery('simple', ''' ' || 'orange' || ' ''' || ':*')), 0)) AS rank
   FROM "foods"
   WHERE ((to_tsvector('simple', coalesce("foods"."name"::text, ''))) @@ (to_tsquery('simple', ''' ' || 'orange' || ' ''' || ':*')))) AS pg_search_d4392ced9dff0647fed4ed ON "foods"."id" = pg_search_d4392ced9dff0647fed4ed.pg_search_id
ORDER BY pg_search_d4392ced9dff0647fed4ed.rank DESC,
         "foods"."id" ASC;

Ive created this index, which seems to work quite well
CREATE INDEX concurrently foods_gin ON foods USING gin
(to_tsvector('simple', coalesce("foods"."name"::text, '')));

I have another column, category. there are 9 categories. For a given search as shown above for name, I want to show results from category 9 first, and then all the other categories (order doesn't matter).
ideally the results could be paginated, so a perfect query/index combo would be great.
is this possible to do, and/or will it be a truly gigantic index?
p.s. suggestions for a better name for the question are welcome
Answer: With the help of the btree_gin extension, you can include an int column into your index, but doing so will not offer you an advantage.  The way gin indexes work, it can't be used for ordering.
You should write your query first, and worry about optimizing once you have something to optimize.


Engine dies and positive wire starts bubbling after splashed with water

Question: I had made a turn and as I turned a big puddle of water covered my front window / hood. As I completed my turn my truck died so I figured it was something basic. I popped the hood and tried starting the ignition. As I turned the ignition the positive wires on the battery start bubbling and smoking, even just with the key back ... what is my problem?
Comment: How long did you try to start and did the engine turn over? If the engine sucked up a lot of water it could be hydrolocked and cannot move. If you try to do it anyway the starter motor will draw a very big current because it cannot turn. If you keep doing this for several seconds the battery cables could get quite hot.
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Comment: Are you sure it was smoke and not steam coming off the cable? And when you say the cables started *"bubbling"* what do you mean? Was the cable visibly moving around? Or was the insulation moving? Or were there bubbles popping off of the battery terminal?
Answer: It sounds as though either the connection at your battery needs to be cleaned up (the positive side), or the cable itself is bad. If there is any corrosion around the terminal, clean it up and put some grease on it after you've got it back together. If you see any bulging in the positive wire, replace it. While you're at it, clean/check the negative as well. You'll want to clean the ground where it connects to things to ensure you have a good connection.
After you've got everything cleaned and back together, check the voltage on the battery. It should be around 12.5-13.1vdc. After that, start up your truck and check the voltage at the battery. It should be in the 13.5-14.1vdc arena. If these ring true, you should be good to go.


Differentials to compute the maximum errors

Question: Question: The radius of a circle was measured and found to be 10 cm with a possible error in measurement of +0.02 cm. Use differentials to compute the maximum error in using this radius to compute the area of the circle.
Okay, so I know that I have to find the derivative of the line so i can get my slope but Im not sure how to complete the rest of the problem. Please help!!
Answer: You have $$A=\pi r^2\implies \frac{dA}{dr}=2\pi r\implies dA=2\pi r\, dr\implies \Delta A=2\pi r\, \Delta r$$


Detrimental impact of magnetic field on PCB and battery?

Question: We are developing a small consumer electronics product consisting of a small 4-layer PCB along with a few PDM microphones and BLE chip/ an antenna, as well as a LiPo battery. We are locating a small but pretty strong magnet next to these components in the enclosure. It is an N52 (Surface Field: 3032 Gauss, \$B_{r_{max}}\$: 14,800 Gauss, \$B_{H_{max}}\$: 52 MGOe). Are there any long term effects of the magnet which may be detrimental to the battery or PCB electronics?
Comment: The magnet may affect the antenna, simply by being a conductive object in its vicinity, thereby altering the radiation pattern. If much smaller than the wavelength, the effect will be as a capacitor; if the magnet is larger, than it may act as a reflector. In either case, this has nothing to do with a static magnetic field.
Comment: One of those "probably not" questions that still needs an authoritative answer. I suggest you post details about the microphones, they _could_ use magnets.
Answer:
LiPo Battery - The battery will be fine.  A good way to verify this is to see if your magnet is attracted to the battery at all.  There can be some weird variations on LiPo chemistry, but as far as I know, there aren't any ferromagnetic materials in most, if not all, LiPo cells.  High strength (even N52 grade) magnets are frequently used to attach LiPo batteries in hobbyist RC products, and many other consumer products.
Magnetic Cores - I know you didn't mention this, but this is really the only thing you need to worry about.  Static magnetic fields generally won't impact how the circuit itself behaves (ignoring magnetic cores, of course), but static magnetic fields will impact any bulk magnetic material used in the circuit.  This includes any inductors that don't use an air core and ferrite beads.
All magnetic core materials can saturate.  With inductors, this is usually specified as saturation current, which is the current through the inductor that, if you exceed, will cause a rapid drop in inductance.  Measuring it as current is just for our convenience, and what is really occurring during saturation is that the magnetic field in the core has reached saturation.
Any nearby static magnetic fields will cause some degree of magnetization in the core material, and any current or ripple current through the inductor will be another field superimposed on the core material.  Depending on the exact properties and geometry of the core, this can potentially lower the saturation of the core well below spec, or increase losses in the core.
So this is very much worth considering, especially if you are using any power inductors (like in a buck or boost converter) that you're running near saturation.
That said, the saturation field for power ferrites is usually in the range of 300mT (conservatively).  So that is already equal to the surface field of your magnet. Considering that magnetic fields fall off at distance cubed (as opposed to squared), so you can be extremely close to a magnet and experience almost negligable field strength from it.
Case in point: assuming your magnet is an N52 square 10mm x 10mm x 2.5mm (which would yield a surface field of about 3000 gauss, give or take.  Unless the dimensions are different by a huge amount, numbers will be similar), the static magnetic field just 2mm away from the center, in the direction of the poles, will be ~2140 gauss or 214mT.  5mm, and it is down to 993 gauss.  This is low enough that I would not be concerned.

So the short answer to if it will affect your circuit is: maybe.  But probably not, especially if you put even the tiniest amount of distance between the magnet and inductors that might present on board or inside the bluetooth module.


STM32F407 fallback to Internal Osc

Question: I wonder if it is possible at run time to detect that an external Oscillator has gone bad and the application now falls back to internal Oscillator.. specially for the case of STM32F407 MCU?
Comment: How do you plan to run the code which changes the clock source whilst there is no clock?
Comment: The clock security system, if enabled, will switch to an internal clock so you can still recover from that and shut down things gracefully, or continue at reduced speed or reduced accuracy if necessary. In this case, it falls back to the 16MHz HSI RC, and triggers a clock fail interrupt. User code can then do whatever it likes, like reconfigure it via PLL to get 168 MHz core clock again, or just run at the 16 MHz directly, or wait for the external clock to start again. The internal oscillator is only factory calibrated to 1% which may not be accurate enough for some interfaces like Ethernet.
Comment: Thats a good question ;)  Possibly by some smart hardware move instead of under software control.
Comment: The reason to use a crystal over an internal oscillator are numerous but generally it comes down to precision/consistency. If your project can happy work with the internal oscillator why bother with the crystal in the first place?
Answer: From the datasheet you link,

2.2.12 Clocks and startup
On reset the 16 MHz internal RC oscillator is selected as the default CPU clock. The
16 MHz internal RC oscillator is factory-trimmed to offer 1% accuracy over the full
temperature range. The application can then select as system clock either the RC oscillator
or an external 4-26 MHz clock source. This clock can be monitored for failure. If a failure is
detected, the system automatically switches back to the internal RC oscillator and a
software interrupt is generated (if enabled).

There is already hardware in the chip, and a system in place to do what you want.
Answer: Read the manual instead of some "datasheet". Manual chapter 6.2.7

6.2.7 Clock security system (CSS)
The clock security system can be activated by software. In this case, the clock detector is
enabled after the HSE oscillator startup delay, and disabled when this oscillator is stopped.
If a failure is detected on the HSE clock, this oscillator is automatically disabled, a clock
failure event is sent to the break inputs of advanced-control timers TIM1 and TIM8, and an
interrupt is generated to inform the software about the failure (clock security system
interrupt CSSI), allowing the MCU to perform rescue operations. The CSSI is linked to the
Cortex®-M4 with FPU NMI (non-maskable interrupt) exception vector.

As explained in another answer, the internal RC oscillator will kick in to let you continue executing code dealing with the failure. This is sometimes referred to as "limp home mode" and is pretty much standard on modern MCUs.

STM32F407 fallback to Internal Osc


What's the law of Bittul and powdered milk?

Question: Suppose someone took a tea-spoon of powdered milk, reconstituted it into normal milk, and accidentally dropped some of it on meat. Do we measure the bittul of the resulting mixture against the powder or against the "reconstitution"?
Comment: @Double Who tastes food nowadays to see if its batul?
Comment: @Double And by nowadays I mean more than just post Maharam Padowa as brought in the Ramma saying we don't do this anymore. I mean post Kaf HaChaim saying that even Sfardim can't do taste tests anymore, and even Chacham Ovadia who thought that was too 'Ashkenized' of a psak, still agreed that unless its a hefsed meruba, one should not do it.
Comment: @Double why would you say something like that?
Comment: You taste it...
Comment: @user6591 To see if it's batel?
Comment: That should have said Kaf HaChaim quoting Ben Ish Chai
Answer: The OU says that powdered milk, when evaluating bittul, they look at the powdered form, not the reconstructed amount (unlike grape juice concentrate where they look at the volume when reconstructed).
However, in the case you present, the milk was reconstructed prior. That is more a case of Chanan, which does not apply here because it only applies to Issur (which youre case is ostensibly not) and even if the milk was not Cholov Yisroel, according to the OU anyway.
Comment: Why is not like a _tavlin_? (or from the other perspective, why not always evaluate milk by it's powered equivalent?) I don't know why you have to get into Chanan. The added water doesn't add any flavor at all. Even if the water becomes chanamilchig it's batel berov.
Comment: @DoubleAA, re: *Tavlin*, the OU compares it to cheese - the fact that it is more concentrated doesn't change the bittul calculations. Re the other perspective, all estimates of 60 are on the thing, not some theoretically concentrated but of equal potency equivalent. I don't understand why you think the water is bottul.
Answer: I'd say the reconstitution. "Foodstuffs" are batel 1:60 by volume. "Flavorings" aren't batel until you really can't taste them. The question is which way concentrates go -- and I assume powdered milk is stronger than a "foodstuff."
The question came up with regards to some beer that was being run on the same line as ... clam juice, I think? Some of the ingredients were concentrated, so the question of bitul came up there.


Do stocks made with less water lack the same flavor as a stock made with lots of water?

Question: I am interested in knowing whether there is a difference in flavor between a stock made in a small pot, with just enough room to cover the ingredients, vs a large pot with the same amount of ingredients and double (or more) water. For the sake of comparability, they cook for the same amount of time, same heat, same yield (adding water to the smaller pot as it evaporates, but not doing so for the larger pot).
Comment: if they cook the same time, the pot with more water will be more diluted.
Comment: @Max even if the yield is the same?
Answer: The less water you use the more concentrated the flavor of the stock. Adding lots of water doesn't extract more flavor from the ingredients, it just dilutes it.
If you add too much water to the pot you'll have to cook it down much more to concentrate it, there's two effects to this:

It will waste energy, therefore money and be bad for the environment
The extra cooking time will cause a loss of flavor. The longer you expose it to heat the more volatile organic compounds will break down or evaporate

So, use only the amount of water you need.
Comment: All things being equal, I'd guess that concentrating a stock down from a dilute base would extract more of whatever you're trying to get out of whatever is supplying your flavour - compounds will leave down a concentration gradient, so a dilute stock will provide a greater "pull" out of the chicken carcass or whatever you're using. That may not be worth the extra work, and depends on how thermo stable whatever you're trying to extract is.
Comment: Have you tried this experimentally? Your statement, "Adding lots of water doesn't extract more flavor from the ingredients" contradicts the chemistry of extraction processes - more water always extracts more "stuff". I don't actually know what the final result is in practice, so do you have observations or sources to confirm that the final effect in stock is not better with more water and then concentrating?
Comment: @AlexMA My instinct (hence my answer) is that the difference in concentration between the ingredients and stock is so big that changing the amount of water can't make much of a difference to the extraction. As heuristic evidence, I've heard of chefs using a pressure cooker and lots of time to make better stock, but I've never heard of someone advising a huge amount of water, or to change the water half-way through in order to extract more flavour compounds, which is what I'd expect high-end chefs to do if that worked.
Comment: @lupe and rumtscho yes, you both have identified the essence of my question. It is not about yield but about the pull/extraction process of a dilute medium vs a concentrated one.
Comment: @dbmag9 thanks. if you're inclined, I would suggest folding this comment into your answer and suggesting the pressure cooker method as well. That would result in a comprehensive answer. The evidence you shared (what high-end chefs do) is also highly relevant.
Comment: @AlexMA I've done so.
Answer: I would expect the water to extract the same quantity of flavour compounds from the ingredients, if it is simmered for the same time at the same temperature. If the amount of water was very small it might extract less, but if there is enough water to cover the ingredients then additional water won't extract more.
My reasoning (armchair speculation, not experimental evidence) is that the difference in concentration between the ingredients and stock (however strong it is) is so big that changing the amount of water wouldn't make much of a difference to the extraction. As heuristic evidence, I've heard of chefs using a pressure cooker and lots of time to make better stock, but I've never heard of someone advising a huge amount of water, or to change the water half-way through in order to extract more flavour compounds, which is what I'd expect high-end chefs to do if that worked.
Therefore, the stock with double the water will be more dilute than the stock with less water: the flavour will be less strong because the same quantity of flavour compounds will be spread across a greater volume. You can concentrate it more by allowing water to evaporate over time depending on the strength you want at the end.
Comment: I've always wondered if evaporation occurs to water AND some of the extracted flavors (therefore losing some flavors with the evaporation). If so, wouldn't it be better to add the correct amount (or less) of water, put a lid, and add more if needed? Not only for stocks but also stews? In my head, it will cook better and have more flavor as less water is used and there is more concentration of heat and flavors.
Comment: @M.K I think there probably is some loss of flavour as volatile compounds float away with the steam, and I've always seen it advised to use a lid when making stock. Having said that, I think stock generally focuses on the flavours that survive long simmering; the flavours that are more volatile are best added at the end (think of fresh herbs for example) anyway.


What are techniques to analyze requirements in order to write test cases?

Question: Can you please share your techniques that you had used to analyze requirements in order to write test cases? May be a lot of it comes with experience, in my case I remember I had struggled with financial projects but not so much with application /web testing projects.
The biggest one was coming up with negative test cases. I googled and found most of the results were about gathering requirement: for BA.
Don't forget to post a good link if you have found one.
Answer: There are three ways to design the test cases

Behavioural, As over the period of time a tester develops a sense to figure out the areas of issue.
Look at the functionality and the specification
Use the BVA and ECP concepts

For more details you can navigate to this page: http://prelrik.wordpress.com where you'll find more useful links and topic and out of all I'll suggest you this where you can understand that how all the testing types can be implemented for a sample signup form.
Answer: In my experience this is what I have seen as the most effective way.
The starting point will be Business Requirements and Product Requirement documents. This helps to derive test cases and then drill down to Solution design documents and detailed designs.
E.g. from a Web Application testing project.
Product Requirement A. As a Product owner the company's logo must be visible on the Login page in Arial Font size 10.
Business Requirement a. The application when accessed via PC/Mac must display a login prompt to the user just below the company logo on Welcome screen.
Solution Design : When referenced the solution design will give more insight to the flow from the login page to the subsequent components
Detailed design of the Login component will emphasise whether it uses http/https. How it is hosted and triggered. API detail, etc.
Assuming you/your team is responsible for entire testing, you will need to refer to all the documents to ensure all the areas are covered in test including negative tests.
In larger organisations where there are multiple teams and vendors are involved the responsibilities may change and accordingly documentation to be referred changes as the test scope changes.


How to install and wire up a 30 amp breaker box acceptable to plug my RV in

Question: I'm trying to put my RV into the breaker box I've got a 30 amp breaker double pole I've got10/2 wire, do I use a single pole or double pole 30 amp breaker hand my RV plug is a 4 prong plug how do I make this work
Comment: Are you saying your RV has a NEMA 14-30? (think "plugs into the dryer outlet in a brand new house")
Comment: The typical 30A plug on an RV is a special TT-30 (TT=Travel Trailer). Since he said it has a 4 pronged plug, I bet his RV takes 50A service and plugs into a 14-50R.
Comment: Is this a modestly sized RV or is it one of those huge greyhound bus sized things with the pop-outs that tows an SUV and costs well into 6 digits?
Answer: RV's typically take 120VAC with an oddball 30 amp receptacle: this.

Note the center hole is not a terminal.
It will work fine with your 10/2 wire, but your breaker is 2-pole unnecessarily - a single-pole breaker would do.  (Though, a single pole 30A breaker is kind of an orphan, hardly used for anything - the 2-pole breaker is commonly used for several purposes.)
Neutral goes to your neutral bus, ground goes to your ground bus.  Hot goes to one side of the 2-pole breaker, the other side is unused.

If you wanted to use a NEMA 14-30 connection, you bought the right breaker but the wrong wire.  But it would surprise me if you wanted that since 240V/30A is not common with RVs, usually it's 50A if it's 240V.
Comment: Then he has the wrong *everything*.  Which would surprise me.  People usually don't go off the rails that bad.  Also, call it stereotyping but I assume anyone who can afford one of the monster RVs just picks up the phone and *has someone* do his electric.
Comment: Since he said his RV has a 4 pronged plug, I suspect that it has a 50A cord, which would typically plug into a 4 prong 14-50R.
Comment: Wouldn't be that surprising, 30A service is very common among RV's (many parks only provide 30A service), and once the 50A label fades off the side of the RV, it's not always obvious whether the RV is configured for 30A or 50A service. He's probably got a TT-30 to 14-50R adapter cable that he uses when he can't find 50A service.


'Every two' as synonymous with 'every other'

Question: In the sentence "a copy for every two people", i.e. 'to share", would every two be synomymous with every other, where the latter would be used in the same sense as it is used in "I used to visit her every other week"?
Comment: _Every other_ means 'in sequence'. If you give a copy to every other person, you give one to the first person you approach, none to the second, one to the third, none to the fourth, and so on. Sharing is up to them. If you provide a copy for every two people, you simply provide one-half as many copies as people. Again, without explicit information, sharing is up to the recipients.
Comment: In practice, *I go every other week* and *I go every two weeks* are equivalent. I suppose that's really just because the Arrow of Time dictates that there's *always* a natural sequence (and concept of "consecutive") for weeks, but there's no such equivalent for "people" (who might want a printed copy of something).
Comment: As it is, this question belongs on the [English Language Learners](https://ell.stackexchange.com/) StackExchange. However, if you rephrase it as a question about **when** the two constructions are equivalent, and when not, and if you show a bit of preliminary research, then you'd have a nice on-topic question.
Answer: No, they are not synonymous.
In common usage:

with "a copy for every two people", two people share one copy, as you indicate; whereas
with "a copy for every other person", one person from each pair gets a copy and the other misses out.

There is no sharing implied in the "every other person" case.
Comment: Interestingly, however, they **are** interchangeable in such constructions as *we are getting paid [every other week] /[every two weeks].*
Comment: @linguisticturn Interesting, indeed - something's happening there that doesn't translate to the *copy* example. However, I think the "for" is important - getting paid "*for* every other week" isn't the same as getting paid "*for* every two weeks". Including the 'for' changes the sense of the *paid* example to parallel the *copy* example.


Canada certificate program

Question: I did my UG in engg from India and worked as media specialist for 1.5 years. Is it advisable to do a post graduate certificate program on Advertising - Creative & Digital Strategy from centennial or should I do masters. Will I get work permit after that. How about job opportunities.
Comment: What's your ultimate goal? Do you wanna settle down in Canada? or do you just want to study more? If you have want to settle down you might be able to qualify under the **Express Entry program**.
Comment: I would like to settle down in Canada.
Comment: Consider the express entry program that government of Canada provides. If you have enough points you might qualify for permanent residence in Canada. I'll post an answer in sometime giving you more details about this
Answer: Based on your comment, I think you have a couple options.
Option 1
You can apply for permanent residence under Express Entry.
It works on a Comprehensive Ranking System (CRS). Under this system, there are various factors considered to award you points. And based on this point system, CIC does 2 draws every month. If your points are over the cut off points, you will get an invitation to apply for permanent residence to Canada.
In this factors like age, level of education, official languages proficiency, Canadian work experience are considered. Moreover you can score extra points if you have a spouse or common law partner. The average points have been around 450-500 points recently. But its never sure.
I think your current job experience puts you in the category 1123 Professional occupations in advertising, marketing and public relations or 0124 Advertising, marketing and public relations managers category. However I am not too sure about this. Take a look at the link for more details.
Option 2
This is a long journey to go but it is still an option. You can consider taking a masters program or a 2 year diploma program. I leave that decision to you. But after graduating you will be able to get a work permit and get a job in Canada. If everything works out for you, you can apply under provincial nomination which will give you 600 points in the CRS system. This is going to be a lengthy process because you will be studying and working for atleast 2 years. In any way you will need to apply under Express Entry to immigrate ASAP to Canada.

Canada certificate program


Can two planning PDDL actions be taken simultaneously?

Question: We are discussing planning algorithms currently, and the question is to describe the steps to check if actions could be taken simultaneously. This is a really open-ended question so I'm not sure where to start.
Answer: First place to look is how the preconditions/effects of different actions interact.
Comment: We expect answers to provide more details. So, I would suggest that you review this answer to make it more complete.
Answer: I don't see any principal problem with that. The way I would approach it is to have a resource model and durations attached to actions.
For example, movement would put a lock on your legs. You can't have another movement at the same time, as your legs are already busy. But your attention might only be partially occupied, so you can make a phone call while you're moving. You won't be able to read a book, because your eyes might be partially busy monitoring the walking action. This can be encoded in pre- and post-conditions.
What will probably be easier is to parallelise the execution of the plan. Once the plan has been created, organise the actions in a Gantt-chart like structure. You can have mutual exclusion in there, so all 'movement' would be restricted to one single row, so no more than one movement can take place at the same time. But 'making a phone call' could be in a separate row, and thus execute in parallel. The details depend on the requirements of the actions.
I can't easily think of a way that it would impact the planning process itself; unless there are critical timings involved. So leaving the planner to do its thing might keep it simpler, and then the optimal execution could be a post-processing step.


Is "How you feel about it" a correct sentence?

Question: You can see many sentences like: "How you felt when you were in love", "How you can't sleep", "How you feeling" in friends series.
My question is that are these sentences correct?
They shouldn't be "How did you feel....", "How can't you sleep", "How are you feeling" ?
Comment: 'How' does not always start a question.
Answer: "How you feeling" is "How're you feeling" but the "'re" is very similar in sound to the "ow" of how and tends to be reduced in speech, to the point of being inaudible, and sometimes omitted when written.
The other phrases are not questions. They are noun phrases:

How I felt when I was in love was happy and dizzy.

You can form these noun phrases that start with How, What, Where etc. Phrases starting "How" mean "the way that (you felt when you were in love)"
These could also be errors, (for something like "how is it that you can't sleep") We couldn't decide if they are errors without some more context.


Manga where the male lead has to team up with a female, and for their power to be stronger she needs to be intimate, and they fight these creatures

Question: The manga from what I remember is about a male lead who is the son or grandson of a male who leads this division of powerful females that power up into this armour to battle these giant creatures which occur every now and then. One thing I remember is for them to be more powerful, they need to be intimate with their partner but that doesn't happen for a while.
Comment: Hi, welcome to the site. Was this in full colour or mostly black & white? What sort of time period was the story set in? And do you recall the hair colour of any of the main characters?
Comment: Does this take place in modern times? Do all the women live with the guy? Is the guy a late high school student/early college student (i.e. not a working adult)? Does the powerup come from non-sexual intimacy like going on dates? I've read a story similar to this, but the powerups start immediately, even in the first chapter.
Comment: Can you clarify if the male lead is partnered with a single woman, or if he's responsible for powering up several women? If he's the son/grandson of someone in a similar situation, is this father/grandfather still around in this story, or is that just a background detail?
Answer: This is likely Val x Love. There are a number of differences from the question, but the basic structure is a match.

High schooler Takuma Akutsu is terrified of human contact and just wants to live a quite life. Too bad he doesn't have a choice in the matter when nine Valkyrie sisters come barging into his home! They've tasked him with raising their level to fight off the monsters threatening humanity--and how will he do that, exactly...? By gettin' down & dirty to the max!!!

The demons would be the akuma - giant monsters that randomly show up. The designs are varied but in general they're huge and monstrous.

As mentioned in the synopsis, the main character needs to "power up" the girls by being intimate with them, e.g. by holding hands while shopping together, studying together, or otherwise acting like lovers. This is complicated by the main character's anthropophobia and the fact that most of the girls dislike the main character.

Powering up allows them to transform - not into armor, but they do get special uniforms.

The other major difference is that neither the main character's father nor grandfather shows up. However, Odin is referenced multiple times and referred to as the girls' father.


What kind of phases nanoparticles have (gas-solid-liquid)?

Question: If a phase transition requires a number of particles that is in the TD-limit, can nanoparticles (~10 atoms) have phase transitions? What kind of phases and transitions nanoparticles have?
Comment: While I appreciate that this is indirectly related to your question, nanoparticles can have thousands of atoms, since volume goes as the cube of the radius. When the number of atoms is in the thousands, you can have as many transitions as bulk matter.
Comment: (Volume goes as the third power of the radius)
Comment: When a nanoparticle melts, you stop calling it a nanoparticle...
Answer: We can't really talk generally about the phase of an individual nanoparticle, as we aren't in the thermodynamic limit, as the question you linked to suggests.
Think about what a gas is, for example: gases have a higher average kinetic energy than a liquid, which causes it to be less dense and occupy a greater volume than liquid. But if we look at the particles comprising the gas at a microscopic level, we see a distribution of velocities - there will be some proportion of the molecules that have less kinetic energy than the average energy of, say, a liquid. But in a liquid, there will be some small proportion of molecules that have more kinetic energy than the average kinetic energy of a gaseous phase. So it makes sense to talk about phases in terms of an average over a large number of particles and not in terms of an individual particle. The number of particles comprising a nanoparticle is many orders of magnitude less than that required for the thermodynamic limit.
I suppose you could describe a single nanoparticle in a Bose Einstein Condensate state, since the BEC phase is described by all particles taking on a common wavefunction which is a different requirement than some sort of average over many particles.
You can, however, talk about the phase of a large collection of nanoparticles; this is no different than how we describe the solid, liquid, or gaseous state of any other material.


Is background lore considered worldbuilding or storytelling?

Question: I'm hoping to ask a question related to a funny narrator anecdote similar to what you find in Hitchhiker's Guide to the Galaxy, though with some interaction with the main character. However, I'm not entirely sure if anecdotes like that are considered worldbuilding or storytelling. In case it's relevant, the anecdote is about a chef with germophobia who does not want to have any utensils or cooking wear or surfaces to contact the food he's preparing, not even when the guests are eating it, and who does everything with lasers for cutting and magnets for manipulating the food. The question I wanted to ask is what cooking techniques he wouldn't be able to use (although if this is too broad, let me know and I'll jump by in chat or the sandbox to see if I can get something with a narrower scope put together). Is this considered worldbuilding with regards to the scope of the site?
Comment: We have a sandbox for this, so that meta doesn't get clogged with "is this question in scope?"
Comment: Nzall it may not be a good fit for the main site but if you jump in our [chat room](https://chat.stackexchange.com/rooms/17213/the-factory-floor) people are generally happy to discuss stuff like this.
Answer: Thanks for clarifying before opening a question. You may also use the Sandbox to see whether a question is fit for the site, and get help on how to improve it.
As it stands, there is not much about the building of a world there - you wish to discuss what a character would do, not how a world would work. That is story based.
There is a stack that is scoped towards writing stories. However, writing.SE helps users on questions related to how to write, never what to write.
It seems to me that you wish to refine a joke. While I collect comedy sci-fi and I would love to help, ultimately you are seeking for a creative solution for a scene. I do not think there is a site at Stack Exchange that can be of much help, but I do wish you think of something clever that you end up liking for your novel.


Summation of Greatest Integer $ \sum_{k=1}^{n} \left \lfloor{\sqrt{k}}\right \rfloor $

Question: I want to know the concept behind summing up a Greatest Integer function like $\sum_{k=1}^{n} \left \lfloor{x}\right \rfloor $ can be evaluated by simply writing the series but something like $$ \sum_{k=1}^{n} \left \lfloor{\sqrt{k}}\right \rfloor $$ This is creating problem by simply writing the series it came out to be $$ S=1\times3 +2\times4+3\times5+4\times6+... $$
The sum of this can be written as $$ \sum_{r=1}^{n} (r)(2r+1)  $$ but then i am not able to relate $r$ and $k$ to each other.
Answer: For any given $m\geq0$, we have $\lfloor\sqrt{k}\rfloor=m$ if and only if $m^2\leq k<(m+1)^2$. So the number of times $m$ occours in the sum is
$$(m+1)^2-m^2=2m+1.$$
Setting $\ell:=\lfloor\sqrt{n}\rfloor$ this indeed leads to the simplification you already found:
$$\sum_{k=0}^n\lfloor\sqrt{k}\rfloor=\ell\cdot(n+1-\ell^2)+\sum_{m=0}^{\ell-1}m\cdot(2m+1),$$
where the term $\ell\cdot(n+1-\ell^2)$ comes from the fact that we're not summing over all integers $k$ for which $\lfloor\sqrt{k}\rfloor=\ell$, but just the first $n+1-\ell^2$ such integers. Now we can write the sum out as
\begin{eqnarray*}
\ell\cdot(n+1-\ell^2)+\sum_{m=0}^{\ell-1}m\cdot(2m+1)
&=&\ell\cdot(n+1-\ell^2)+2\sum_{m=0}^{\ell-1}m^2+\sum_{m=0}^{\ell-1}m\\
&=&\ell\cdot(n+1-\ell^2)+\frac{1}{3}\cdot\ell(\ell-1)(2\ell-1)+\frac{1}{2}\ell(\ell-1)\\
&=&-\frac{1}{3}\ell^3-\frac{1}{2}\ell^2+\left(n+\frac{5}{6}\right)\ell\\
&=&n\ell-\frac{1}{6}\ell\left(\ell-1\right)\left(2\ell+5\right)
\end{eqnarray*}
Comment: Thanks for the help. Kindly elaborate the part $ l\times (n+1-l^2) $?
Comment: Each value $m<\lfloor\sqrt{n}\rfloor$ is summed precisely $2m+1$ times, as explained in my answer. The last value $\ell=\lfloor\sqrt{n}\rfloor$ might be summed fewer times, depending on $n$. The number of times it is summed is precisely $n+1-\ell^2$, so this sums to $\ell\cdot(n+1-\ell^2)$.


What is the Biblical basis for the idea that spiritual gifts are no longer relevant?

Question: There is a verse that some denominations use to say that the gifts are not operative since the days of the Apostles. Where is that verse?
Comment: I have updated your title to both match your question, and to be on-topic and less opinion-based. And welcome to our site!
Answer: 1 Corinthians 13 8 is a verse sometimes referred to as supporting the theory that some spiritual gifts no longer operate.

Love never fails: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away.

This  article discusses the question from the perspective of Grace Community Church California, concluding that some gifts no longer operate.
Comment: Good link, the only difficulty in the article is the "absence of evidence /= evidence of absence" issue (in terms of where in Scripture evidentiary issues end) but that should be taken up with the author rather than here.  Very helpful.
Answer: The verse is 1Corinthians 13:8.
In this article
http://wol.jw.org/en/wol/d/r1/lp-e/2009334#h=11
produced by Jehovah's Witnesses the cessation of gifts like healing is discussed: the salient points are pretty much contained in the paragraphs below :

"During the first century, miraculous healings were performed by Jesus Christ and his apostles. At that time in Christian history, the gifts of the spirit, including the ability to perform healings, were for the glory of God and were a sign of Jehovah's approval and blessing on the young Christian congregation. But once mature or fully established, rather than pointing to special gifts, the Christian congregation would point to its display of unswerving faith, hope, and love as evidence of God's approval. (John 13:35; 1 Corinthians 13:13) Thus, about the year 100 C.E., miraculous healings as a mark of God's favor ceased"
Evidently, with the death of the apostles, the transmittal of the gifts ended, and the miraculous gifts of the spirit ceased altogether as those who had received these gifts died.

So it would be wise for Christians to ask:  Is it possible for other spiritual creatures to enable humans to appear to have a gift like healing that would in fact be demonic at its source?
1 Corinthians 11:14&15 (NIV)

14 And no wonder, for Satan himself masquerades as an angel of light.
15 It is not surprising, then, if his servants also masquerade as servants of righteousness. Their end will be what their actions deserve.


Connect to Sharepoint Database through PHP

Question: I am not familiar with Sharepoint. I would like to query or read Sharepoint database using PHP.
Is there a way I can do that?
Thank you in advanc. Any help is greatly appreciated.
Comment: [link](http://stackoverflow.com/questions/3565845/sharepoint-access-sql-sharepoint-files)Try this
Answer: i highly recommend using the SharePoint WebServices instead... unless there are valid reasons (i.e. performance) i would not touch the database. Quote from this answer:

This is completely unsupported by the EULA you agreed to when you
  installed SharePoint.
Your queries are not guaranteed to work after
  applying any patches or service packs to SharePoint since Microsoft
  could change the database schema anytime.
Directly querying the  database can place extra load on a server and hence performance
  issues.
Direct SELECT statements against the database take shared
  read locks at the default transaction level so your custom queries
  might cause deadlocks and hence stability issues.
Your custom
  queries might lead to incorrect data being retrieved.

If you want to know more about why you shouldn't query the database, here is a really great article
Query A SharePoint WebService with PHP
Answer: You should consider using the Camelot PHP Tools for SharePoint, it's a well documented php framework for the Camelot XML format specially constructed for SharePoint lists.
Documentation and download

http://docs.bendsoft.com/camelot-php-tools/
http://www.bendsoft.com/downloads/sharepoint-php-tools/

You will also need the Camelot SharePoint Integration Toolkit, http://camelottoolkit.codeplex.com/ and the Camelot .NET Connector (http://www.bendsoft.com/net-sharepoint-connector/).
Install the Connector on a box that can reach the SharePoint server, this may be the same server as the SharePoint server, then install the Integration Toolkit on the same server as the Connector. Set up the integration service that is included in the integration toolkit (follow the instructions) and then you are done. There are a few instruction videos on the websites as well.
The upsides of using this is that you will be able to talk to SharePoint lists and libraries through the API by using common SQL queries, the underlying mssql database is never used.
Selecting data from SharePoint with SQL
$SharePointQuery = new SharePointQuery(array(
    'sql' => "SELECT * FROM Tasks WHERE ID > 10",
    'connection_name' => 'SharePointConnection1'
));

Selecting data from SharePoint by list and view name
$SharePointQuery = new SharePointQuery(
    array(
        'listName' => 'Tasks',
        'viewName' => 'All Tasks',
        'includeAttachements' => false,
        'connection_name' => 'SharePointConnection1',
        'columns' => ''
    )
);

Insert data in SharePoint with SQL and SharePointNonQuery
$SharePointNonQuery = new SharePointNonQuery(array(
    'sql' => "INSERT INTO Tasks (Title,AssignedTo,Status,Priority,DueDate,PercentComplete) VALUES ('Test task from PHP',1,'In Progress','(1) High', '".  date('Y-m-d H:i:s') ."',0.95)",
    'method' => 'ExecuteNonQuery',
    'connection_name' => 'SharePointConnection1'
));

There are also stored procedures to help you with some operations, like advanced handling of document libraries
Download a file
$download = new CamelotDownloadFile(array(
    "file" => $_GET["file"],
    "listName" => 'Shared Documents',
    "connection_name" => 'SharePointConnection1'
));

$download->download_file();

Upload a file
$args = array(
    "file" => $_FILES,
    "listName" => 'Shared Documents',
    "folder" => 'Folder/',
    "connection_name" => 'SharePointConnection2'
);

$UploadFile = new CamelotUploadFile($args);

Answer: It's just a database - as long as you have the name of the server/database and the proper permissions, there is nothing that can stop you. However - the schema is pretty involved, so figuring out from there what you need can be tricky - depending on what you really want to do, you may be better off using the web services to access the Sharepoint OM.
In case you want to write to the database directly - don't. There is no practical way to do that without getting yourself into deep trouble farther down the line, and support won't be able to help you out.
Comment: MS policy on direct SharePoint database access is... Don't. http://msdn.microsoft.com/en-us/library/bb861829(v=office.12).aspx you will be much much better off using the Web Services interface - see @Andreas's answer.
Answer: Sharepoint database is nothing but MS SQL Server. If you know the server name, you can connect to it as same as how you can connect to MSSQL server from PHP.
Answer: The easiest way to get SharePoint data from PHP is probably via the REST API.
Answer: I have used this in API to connect my PHP web application with SharePoint and transferring data From PHP to SharePoint, it worked 100% for me:
Usage Instructions:
Installation
Download the WSDL file for the SharePoint Lists you want to interact with. This can normally be obtained at:sharepoint.url/subsite/_vti_bin/Lists.asmx?WSDL
If you are using composer, just add thybag/php-sharepoint-lists-api to your composer.json and run composer.
    {
    "require": {
        "thybag/php-sharepoint-lists-api": "dev-master"
    }
    }
If you are not using composer you can download a copy of the SharePoint API files manually and include the top "SharePointAPI.php" class in your project.
Creating SharePointAPI object
In order to use the PHP SharePoint Lists API you will need a valid user/service account with the permissions to the required list.
For most SharePoint installations, you can create a new instance of the API using:
    use Thybag\SharePointAPI;
            $sp = new SharePointAPI('', '', '');
If your installation requires NTLM Authentication, you can instead use:
    use Thybag\SharePointAPI;
    $sp = new SharePointAPI('', '', '', 'NTLM');
SharePoint Online users must use:
    use Thybag\SharePointAPI;
    $sp = new SharePointAPI('', '', '', 'SPONLINE');
All methods return an Array by default. SetReturnType can be used to specify that results should be returned as objects instead.
Reading from a List.
To return all items from a list use either
    $sp->read('');
or

    $sp->query('')->get();
To return only the first 10 items from a list use:
    $sp->read('', 10);
or
    $sp->query('')->limit(10)->get();
To return all the items from a list where surname is smith use:
    $sp->read('', NULL, array('surname'=>'smith'));
or
    $sp->query('')->where('surname', '=', 'smith')->get();
Querying a list
The query method can be used when you need to specify a query that is to complex to be easily defined using the read methods. Queries are constructed using a number of (hopefully expressive) pseudo SQL methods.
If you, for example, wanted to query a list of pets and return all dogs below the age of 5 (sorted by age) you could use.

    $sp->query('list of pets')->where('type','=','dog')->and_where('age','sort('age','ASC')->get();
If you wanted to get the first 10 pets that were either cats or hamsters you could use:
    $sp->query('list of pets')->where('type','=','cat')->or_where('type','=','hamster')->limit(10)->get();
If you need to return 5 items, but including all fields contained in a list, you can use. (pass false to all_fields to include hidden fields).
    $sp->query('list of pets')->all_fields()->get();
If you have a set of CAML for a specific advanced query you would like to run, you can pass it to the query object using:
    $sp->query('list of pets')->raw_where('Hello World')->limit(10)->get();
Adding to a list
To add a new item to a list you can use either the method "write", "add" or "insert" (all function identically). Creating a new record in a List with the columns forename, surname, age and phone may look like:
    $sp->write('', array('forename'=>'Bob','surname' =>'Smith', 'age'=>40, 'phone'=>'(00000) 000000' ));
You can also run multiple write operations together by using:
    $sp->writeMultiple('', array(array('forename' => 'James'),array('forename' => 'Steve')));
Editing Rows
To edit a row you need to have its ID. Assuming the above row had the ID 5, we could change Bob's name to James with:
    $sp->update('','5', array('forename'=>'James'));/code>
As with the write method you can also run multiple update operations together by using:
    $sp->updateMultiple('', array(    array('ID'=>5,'job'=>'Intern'),array('ID'=>6,'job'=>'Intern')));
When using updateMultiple every item MUST have an ID.
Deleting Rows
In order to delete a row, an ID, as well as list name, is required. To remove the record for James with the ID 5 you would use:
    $sp->delete('', '5');
If you wished to delete a number of records at once, an array of ID's can also be passed to the delete multiple methods
    $sp->deleteMultiple('', array('6','7','8'));
Helper methods
The PHP SharePoint API contains a number of helper methods to make it easier to ensure certain values are in the correct format for some of SharePoint special data types.
dateTime
The DateTime method can either be passed a text-based date
    $date = \Thybag\SharepointApi::dateTime("2012-12-21");
Or a unix timestamp
    $date = \Thybag\SharepointApi::dateTime(time(), true);
Troubleshooting
Unable to find the wrapper "https"
If you are getting this error it normally means that php_openssl (needed to curl https URLs) is not enabled on your web server. With many local web servers (such as XAMPP) you can simply open your php.ini file and uncomment the php_openssl line (ie. remove the; before it).
Note: If you are using SharePoint Online and having SSL errors, please pull the latest version which has changed from SSL v3 to TLS for SharePoint online connections.
Add this line to your composer.json file    thybag/php-sharepoint-lists-api: dev-develop
You can perform CRUD (Create/Read/Update/Delete) operation with above SharePoint API.
Reference URL link: https://github.com/thybag/PHP-SharePoint-Lists-API


How to become vegan if I belong to sub-arctic region?

Question: I want to become vegan but my environment doesn't allow me as I belong to Oymyakonsky district, Sakha Republic. We people of Oymyakonsky eat lot of meat and fish to keep ourselves warm and also because there's no vegetation here. Is there any way so that I can become vegan?
Comment: Welcome! I often wonder how people might avoid eating animal foods in regions with little vegetation. I imagine it would be a great challenge and disruption to one's way of life. I am very interested in your findings.
Comment: Himalayan regions are full of vegetarians although cut off from rest for several months during winter. They survive on storage of food items, milk from mountainous cows n animals , essential supplies during winter etc. Where there is a will, there is a way.
Comment: @sbharti Himalayan regions have bit vegetation. Oymyakons are unable to grow crops, therefore our diet basically consists of reindeer, fish and horse meat.
Comment: Yes it's going to be difficult. You'd need to rely on imports. You'd not get fresh vegetables. But sun dried or boiled and dried ones are common practices. Grains and lentils could be your staple diet. If you get fresh supplies during winter then it's great. I'd also advise to add dairy, although you mentioned vegan. Because it's a practical problem and one solution may not fit all, you'd have to try and test. Cost could be another problem. In usa ppl keep packaged cooked food refrigerated which lasts for months. If you write, would love to hear your experience with veganism in Sakha.
Answer: If you help create a demand for vegan products, then the supply stores around will respond. However, it may take a village. I live in Scandinavia, and have noticed the uptick in vegan/vege products in the past five years as the demand from consumers has increased.
You can also make the argument that vegan products store better in your environment. Dried beans last years in storage, and can be made without heavy salting or other preservatives with a few days prep. It is also much cheaper to buy and store beans than it is cured meats (at least from my perspective). Try to encourage others to diversify their protein intake for both health and economic reasons, which will increase the demand for vegan products in your stores.
Answer: If you cannot become vegan in practice by not eating aminal products, then you can become vegan in spirit by fighting for animal rights.  By fighting for humane treatment of the animals that you have to consume in order to survive.
There are many activities on the internet that you can participate in, that promote animal welfare and that try to stop animal cruelty.
Comment: Will it not be hypocrisy? I tried to register myself for campaign to protect animal lives. The authority rejected my application stating reason that I'm non-vegetarian.


ConnectTransportException in Elastic Search

Question: I am new to Elastic Search and just configured it on my Ubuntu 12.04 . Now whenever I start elastic search it starts normally but after 5 to 8 seconds it throws the following exception.

I have not changed anything in configuration files but yet they are as follows:
logging.yml:
<code># you can override this using by setting a system property, for example -Des.logger.level=DEBUG
es.logger.level: INFO
rootLogger: ${es.logger.level}, console, file
logger:
  # log action execution errors for easier debugging
  action: DEBUG
  # reduce the logging for aws, too much is logged under the default INFO
  com.amazonaws: WARN

  # gateway
  #gateway: DEBUG
  #index.gateway: DEBUG

  # peer shard recovery
  #indices.recovery: DEBUG

  # discovery
  #discovery: TRACE

  index.search.slowlog: TRACE, index_search_slow_log_file
  index.indexing.slowlog: TRACE, index_indexing_slow_log_file

additivity:
  index.search.slowlog: false
  index.indexing.slowlog: false

appender:
  console:
    type: console
    layout:
      type: consolePattern
      conversionPattern: "[%d{ISO8601}][%-5p][%-25c] %m%n"

  file:
    type: dailyRollingFile
    file: ${path.logs}/${cluster.name}.log
    datePattern: "'.'yyyy-MM-dd"
    layout:
      type: pattern
      conversionPattern: "[%d{ISO8601}][%-5p][%-25c] %m%n"

  index_search_slow_log_file:
    type: dailyRollingFile
    file: ${path.logs}/${cluster.name}_index_search_slowlog.log
    datePattern: "'.'yyyy-MM-dd"
    layout:
      type: pattern
      conversionPattern: "[%d{ISO8601}][%-5p][%-25c] %m%n"

  index_indexing_slow_log_file:
    type: dailyRollingFile
    file: ${path.logs}/${cluster.name}_index_indexing_slowlog.log
    datePattern: "'.'yyyy-MM-dd"
    layout:
      type: pattern
      conversionPattern: "[%d{ISO8601}][%-5p][%-25c] %m%n"
</code>
elasticsearch.yml:
<code>##################### Elasticsearch Configuration Example #####################

# This file contains an overview of various configuration settings,
# targeted at operations staff. Application developers should
# consult the guide at <http://elasticsearch.org/guide>.
#
# The installation procedure is covered at
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/setup.html>.
#
# Elasticsearch comes with reasonable defaults for most settings,
# so you can try it out without bothering with configuration.
#
# Most of the time, these defaults are just fine for running a production
# cluster. If you're fine-tuning your cluster, or wondering about the
# effect of certain configuration option, please _do ask_ on the
# mailing list or IRC channel [http://elasticsearch.org/community].

# Any element in the configuration can be replaced with environment variables
# by placing them in ${...} notation. For example:
#
#node.rack: ${RACK_ENV_VAR}

# For information on supported formats and syntax for the config file, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/setup-configuration.html>

################################### Cluster ###################################

# Cluster name identifies your cluster for auto-discovery. If you're running
# multiple clusters on the same network, make sure you're using unique names.
#
cluster.name: jamil_search_cluster

#################################### Node #####################################

# Node names are generated dynamically on startup, so you're relieved
# from configuring them manually. You can tie this node to a specific name:
#
#node.name: "Franz Kafka"

# Every node can be configured to allow or deny being eligible as the master,
# and to allow or deny to store the data.
#
# Allow this node to be eligible as a master node (enabled by default):
#
#node.master: true
#
# Allow this node to store data (enabled by default):
#
#node.data: true

# You can exploit these settings to design advanced cluster topologies.
#
# 1. You want this node to never become a master node, only to hold data.
#    This will be the "workhorse" of your cluster.
#
#node.master: false
#node.data: true
#
# 2. You want this node to only serve as a master: to not store any data and
#    to have free resources. This will be the "coordinator" of your cluster.
#
#node.master: true
#node.data: false
#
# 3. You want this node to be neither master nor data node, but
#    to act as a "search load balancer" (fetching data from nodes,
#    aggregating results, etc.)
#
#node.master: false
#node.data: false

# Use the Cluster Health API [http://localhost:9200/_cluster/health], the
# Node Info API [http://localhost:9200/_nodes] or GUI tools
# such as <http://www.elasticsearch.org/overview/marvel/>,
# <http://github.com/karmi/elasticsearch-paramedic>,
# <http://github.com/lukas-vlcek/bigdesk> and
# <http://mobz.github.com/elasticsearch-head> to inspect the cluster state.

# A node can have generic attributes associated with it, which can later be used
# for customized shard allocation filtering, or allocation awareness. An attribute
# is a simple key value pair, similar to node.key: value, here is an example:
#
#node.rack: rack314

# By default, multiple nodes are allowed to start from the same installation location
# to disable it, set the following:
#node.max_local_storage_nodes: 1

#################################### Index ####################################

# You can set a number of options (such as shard/replica options, mapping
# or analyzer definitions, translog settings, ...) for indices globally,
# in this file.
#
# Note, that it makes more sense to configure index settings specifically for
# a certain index, either when creating it or by using the index templates API.
#
# See <http://elasticsearch.org/guide/en/elasticsearch/reference/current/index-modules.html> and
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/indices-create-index.html>
# for more information.

# Set the number of shards (splits) of an index (5 by default):
#
#index.number_of_shards: 5

# Set the number of replicas (additional copies) of an index (1 by default):
#
#index.number_of_replicas: 1

# Note, that for development on a local machine, with small indices, it usually
# makes sense to "disable" the distributed features:
#
#index.number_of_shards: 1
#index.number_of_replicas: 0

# These settings directly affect the performance of index and search operations
# in your cluster. Assuming you have enough machines to hold shards and
# replicas, the rule of thumb is:
#
# 1. Having more *shards* enhances the _indexing_ performance and allows to
#    _distribute_ a big index across machines.
# 2. Having more *replicas* enhances the _search_ performance and improves the
#    cluster _availability_.
#
# The "number_of_shards" is a one-time setting for an index.
#
# The "number_of_replicas" can be increased or decreased anytime,
# by using the Index Update Settings API.
#
# Elasticsearch takes care about load balancing, relocating, gathering the
# results from nodes, etc. Experiment with different settings to fine-tune
# your setup.

# Use the Index Status API (<http://localhost:9200/A/_status>) to inspect
# the index status.

#################################### Paths ####################################

# Path to directory containing configuration (this file and logging.yml):
#
#path.conf: /path/to/conf

# Path to directory where to store index data allocated for this node.
#
#path.data: /path/to/data
#
# Can optionally include more than one location, causing data to be striped across
# the locations (a la RAID 0) on a file level, favouring locations with most free
# space on creation. For example:
#
#path.data: /path/to/data1,/path/to/data2

# Path to temporary files:
#
#path.work: /path/to/work

# Path to log files:
#
#path.logs: /path/to/logs

# Path to where plugins are installed:
#
#path.plugins: /path/to/plugins

#################################### Plugin ###################################

# If a plugin listed here is not installed for current node, the node will not start.
#
#plugin.mandatory: mapper-attachments,lang-groovy

################################### Memory ####################################

# Elasticsearch performs poorly when JVM starts swapping: you should ensure that
# it _never_ swaps.
#
# Set this property to true to lock the memory:
#
#bootstrap.mlockall: true

# Make sure that the ES_MIN_MEM and ES_MAX_MEM environment variables are set
# to the same value, and that the machine has enough memory to allocate
# for Elasticsearch, leaving enough memory for the operating system itself.
#
# You should also make sure that the Elasticsearch process is allowed to lock
# the memory, eg. by using `ulimit -l unlimited`.

############################## Network And HTTP ###############################

# Elasticsearch, by default, binds itself to the 0.0.0.0 address, and listens
# on port [9200-9300] for HTTP traffic and on port [9300-9400] for node-to-node
# communication. (the range means that if the port is busy, it will automatically
# try the next port).

# Set the bind address specifically (IPv4 or IPv6):
#
network.bind_host: localhost
script.disable_dynamic: true

# Set the address other nodes will use to communicate with this node. If not
# set, it is automatically derived. It must point to an actual IP address.
#
#network.publish_host: 192.168.0.1

# Set both 'bind_host' and 'publish_host':
#
#network.host: 192.168.0.1

# Set a custom port for the node to node communication (9300 by default):
#
#transport.tcp.port: 9300

# Enable compression for all communication between nodes (disabled by default):
#
#transport.tcp.compress: true

# Set a custom port to listen for HTTP traffic:
#
#http.port: 9200

# Set a custom allowed content length:
#
#http.max_content_length: 100mb

# Disable HTTP completely:
#
#http.enabled: false

################################### Gateway ###################################

# The gateway allows for persisting the cluster state between full cluster
# restarts. Every change to the state (such as adding an index) will be stored
# in the gateway, and when the cluster starts up for the first time,
# it will read its state from the gateway.

# There are several types of gateway implementations. For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-gateway.html>.

# The default gateway type is the "local" gateway (recommended):
#
#gateway.type: local

# Settings below control how and when to start the initial recovery process on
# a full cluster restart (to reuse as much local data as possible when using shared
# gateway).

# Allow recovery process after N nodes in a cluster are up:
#
#gateway.recover_after_nodes: 1

# Set the timeout to initiate the recovery process, once the N nodes
# from previous setting are up (accepts time value):
#
#gateway.recover_after_time: 5m

# Set how many nodes are expected in this cluster. Once these N nodes
# are up (and recover_after_nodes is met), begin recovery process immediately
# (without waiting for recover_after_time to expire):
#
#gateway.expected_nodes: 2

############################# Recovery Throttling #############################

# These settings allow to control the process of shards allocation between
# nodes during initial recovery, replica allocation, rebalancing,
# or when adding and removing nodes.

# Set the number of concurrent recoveries happening on a node:
#
# 1. During the initial recovery
#
#cluster.routing.allocation.node_initial_primaries_recoveries: 4
#
# 2. During adding/removing nodes, rebalancing, etc
#
#cluster.routing.allocation.node_concurrent_recoveries: 2

# Set to throttle throughput when recovering (eg. 100mb, by default 20mb):
#
#indices.recovery.max_bytes_per_sec: 20mb

# Set to limit the number of open concurrent streams when
# recovering a shard from a peer:
#
#indices.recovery.concurrent_streams: 5

################################## Discovery ##################################

# Discovery infrastructure ensures nodes can be found within a cluster
# and master node is elected. Multicast discovery is the default.

# Set to ensure a node sees N other master eligible nodes to be considered
# operational within the cluster. This should be set to a quorum/majority of
# the master-eligible nodes in the cluster.
#
#discovery.zen.minimum_master_nodes: 1

# Set the time to wait for ping responses from other nodes when discovering.
# Set this option to a higher value on a slow or congested network
# to minimize discovery failures:
#
#discovery.zen.ping.timeout: 3s

# For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-discovery-zen.html>

# Unicast discovery allows to explicitly control which nodes will be used
# to discover the cluster. It can be used when multicast is not present,
# or to restrict the cluster communication-wise.
#
# 1. Disable multicast discovery (enabled by default):
#
#discovery.zen.ping.multicast.enabled: false
#
# 2. Configure an initial list of master nodes in the cluster
#    to perform discovery when new nodes (master or data) are started:
#
#discovery.zen.ping.unicast.hosts: ["host1", "host2:port"]

# EC2 discovery allows to use AWS EC2 API in order to perform discovery.
#
# You have to install the cloud-aws plugin for enabling the EC2 discovery.
#
# For more information, see
# <http://elasticsearch.org/guide/en/elasticsearch/reference/current/modules-discovery-ec2.html>
#
# See <http://elasticsearch.org/tutorials/elasticsearch-on-ec2/>
# for a step-by-step tutorial.

# GCE discovery allows to use Google Compute Engine API in order to perform discovery.
#
# You have to install the cloud-gce plugin for enabling the GCE discovery.
#
# For more information, see <https://github.com/elasticsearch/elasticsearch-cloud-gce>.

# Azure discovery allows to use Azure API in order to perform discovery.
#
# You have to install the cloud-azure plugin for enabling the Azure discovery.
#
# For more information, see <https://github.com/elasticsearch/elasticsearch-cloud-azure>.

################################## Slow Log ##################################

# Shard level query and fetch threshold logging.

#index.search.slowlog.threshold.query.warn: 10s
#index.search.slowlog.threshold.query.info: 5s
#index.search.slowlog.threshold.query.debug: 2s
#index.search.slowlog.threshold.query.trace: 500ms

#index.search.slowlog.threshold.fetch.warn: 1s
#index.search.slowlog.threshold.fetch.info: 800ms
#index.search.slowlog.threshold.fetch.debug: 500ms
#index.search.slowlog.threshold.fetch.trace: 200ms

#index.indexing.slowlog.threshold.index.warn: 10s
#index.indexing.slowlog.threshold.index.info: 5s
#index.indexing.slowlog.threshold.index.debug: 2s
#index.indexing.slowlog.threshold.index.trace: 500ms

################################## GC Logging ################################

#monitor.jvm.gc.young.warn: 1000ms
#monitor.jvm.gc.young.info: 700ms
#monitor.jvm.gc.young.debug: 400ms

#monitor.jvm.gc.old.warn: 10s
#monitor.jvm.gc.old.info: 5s
#monitor.jvm.gc.old.debug: 2s

################################## Security ################################

# Uncomment if you want to enable JSONP as a valid return transport on the
# http server. With this enabled, it may pose a security risk, so disabling
# it unless you need it is recommended (it is disabled by default).
#
#http.jsonp.enable: true
</code>
Can anyone tell me that what is the root cause of this exception?
Regards
Answer: Elasticsearch is relying on port 9301 on 192.168.0.7 interface to send out and receive multicast requests to search and add cluster members. In this case, the requests are being blocked. This is most probably to do with your firewall setup. This is being blocked as it is not on the loopback interface but on your nic interface and the firewall is blocking it. if this is a single dev machine, do this:
In elasticsearch.yml:
discovery.zen.ping.multicast.enabled: false
discovery.zen.ping.unicast.hosts: ["localhost"]
This should sort your problem out.


A variation of Lévy's characterization of Brownian motion

Question: It is shown here, without using stochastic calculus, that if $W_t$ is a standard Brownian motion, then
$$
f(W_t)-\frac{1}{2}\int_0^t f''(W_s)ds
$$
is a martingale, where $f\in C^2$ and compactly supported. According to Problem 4.4 in Chapter 5 of Karatzas and Shreve's Brownian Motion and Stochastic Calculus, the converse is also true. Namely, if $W$ is a continuous adapted process with $W_0=0$ such that
$$
f(W_t)-\frac{1}{2}\int_0^t f''(W_s)ds\tag{1}
$$
is a martingale whenever $f\in C^2$ and compactly supported, then $W$ is a standard Brownian motion. This is essentially part of the proof of Lévy's characterization of Brownian motion.
Answer: Step 1:

The assumption holds for all $f \in C_b^2$, i.e. functions which are twice differentiable and have bounded continuous derivatives.

To this end, pick a function $\chi \in C^2_b$ such that $0 \leq \chi \leq 1$, $\chi(x) = 1$ for $x \in (-1,1)$ and $\chi(x)=0$ for all $|x|>2$. Then the function
$$f_n(x) := f(x) \cdot \chi \left( \frac{x}{n} \right), \qquad x \in \mathbb{R}, \tag{1}$$
is twice differentiable and has compact support. By assumption,
$$\mathbb{E} \left( f_n(W_t) - \frac{1}{2} \int_0^t f_n''(W_r) \, dr \mid \mathcal{F}_s \right) = f_n(W_s) - \frac{1}{2} \int_0^s f_n''(W_r) \, dr$$
for all $s \leq t$. Definition $(1)$ implies that $$\|f_n\|_{\infty}+ \|f_n'\|_{\infty} + \|f_n''\|_{\infty} \leq C$$ for some constant $C>0$ (which does not depend on $n$). Therefore, it follows from the continuity of $f,f''$ and the (conditional) dominated convergence theorem that
$$\mathbb{E} \left( f(W_t) - \frac{1}{2} \int_0^t f''(W_r) \, dr \mid \mathcal{F}_s \right) = f(W_s) - \frac{1}{2} \int_0^s f''(W_r) \, dr.$$
Step 2:

$(W_t)_{t \geq 0}$ is a Brownian motion.

The claim is proved in this answer (note that, by the first step, the assumptions in the linked question are satisfied). Don't hesitate to ask if you don't get along with it (notation is a bit different there).
Comment: Thanks a lot for your answer and comment. mookid actually provided a link which showed how to complete the argument and obtain independence. So it remained to approximate $f$ as you did, which I was actually fine with. But I definitely appreciate your careful answer, which I'm sure will also help others on this site.
Answer: A martingale is characterized by its characteristic function.

apply the property with $f(x) = x$ proves that $W$ is a martingale
fix $u$ and apply with $f(x) = \exp(iux)$; define
$g(u, t) = \mathrm E(\exp(iuW_t)); M(t) =
f(W_t) - \frac 12\int_0^t f''(W_s) ds$
and you get
$$
1 = M(0) = \mathrm EM(t)
= g(u,t) + \frac 12 u^2\int_o^t g(u, s) ds
$$

whose solution is
$$
g(u, t) = \exp\left(-\frac 12 u^2 t\right)
$$
From this, you get that $W$ is a brownian motion.
Comment: you didn't show independence of increments of BM.
Comment: @mookid Of course I will, but could you please complete your chosen method of proving this, by showing that the increments are stationary and independent?
Comment: @theLowerCrust I think that you can find quite a complete proof here: http://www.imada.sdu.dk/~njn/MM24/levy.pdf
Comment: The second characterisation is easy: take $f(x) = x^2$.
Comment: @mookid The functions $f(x) := x$ and $f(x) := x^2$ don't have a compact support. And in the question it is only assumed that the martingale property holds for compactly supported functions $f$. Moreover, your answer doesn't show that the process is a Brownian motion; the only thing you prove is that $W_t \sim N(0,t)$.


Why are these 'counter' examples in topology?

Question: In Counterexamples in Topology from Steen & Seebach I found the following compact and Hausdorff counterexamples with some properties:
- Lexicographically ordered square: 1st-countable, not separable, not 2nd-countable, not metrizable, connected, not path-connected.
- Concentric circles: 1st-countable, completely normal, not separable, not 2nd-countable, not metrizable.
- Helly Space: Separable, 1st-countable, not 2nd-countable, not metrizable, sequentially compact.
- Double Arrow: Separable, 1st-countable, not 2nd-countable, homogeneous, not metrizable.
I am trying to see exactly why these spaces behave differently from compact metric spaces, but because of a lack of intuition in the properties of compact metric spaces, I can not see why these topological examples are special.
Could you please give me some theorems/properties which compact metric spaces do behave like, but these examples don't?
Comment: @HagenvonEitzen Thanks for your comment. You forgot the word 'metric' in the quote though. I am searching for theorems/properties which metric compact spaces do behave like, but these topological compact spaces do not behave like. Being not separable is indeed a good example, thank you!
Comment: The listed spaces *are* compact. Hence there is no "theorem/properties which compact spaces do behave like, but these examples don't". However, a common intuition is that compact spaces are almost as good as finite sets. Then properties like not separable might by counter-intuitive ...
Answer: Metric spaces are 1st countable.
Compact metric spaces are 2nd countable.
Answer:
All metric spaces are $T_6.$ The lex-order-topology on $[0,1]^2$ is $T_5,$ as are all linear spaces, but this one is  not $T_6$: Singleton subsets are $G_{\delta}$ but the closed set $[0,1]\times \{0,1\}$ is not a $G_{\delta}$ set.
Separable metric spaces are 2nd-countable. Compact metric spaces are separable. The Helly Space and the Double-Arrow space are separable but not 2nd-countable.
I may have seen the Two Circles Space but by a different name.
Comment: The Two Circles example is just the Alexandroff/Aleksandrov double of the circle (inner circle points have usual neighbourhoods unioned with the punctured copy of that neighbourhood in the outer circle, outer circle points are all isolated). All three spaces come from the same Aleksandrov/Urysohn paper on compacta from the early  1900's, they're true classics.


How to add kernel module parameters?

Question: How to add a kernel module parameter in Ubuntu 11.04?
Can I use the /etc/module file? If yes, how?
Comment: Do you mean parameters like `i915.modeset=1`?
Comment: I mean 'options thinkpad_acpi fan_control=1' in a file under /etc/modprobe.d/ or 'thinkpad_acpi fan_control=1' in /etc/modules ?
Answer: /etc/modules seems to be loaded by /etc/init/module-init-tools.conf. The first argument is the module name, other arguments are the parameters. Adding the following to /etc/modules seems fine:
thinkpad_acpi fan_control=1

To load this module and set these parameters in the very early stage of boot, add the previous line to /etc/initramfs-tools/modules file. After a change in that file, you need to regenerate the ramdisk:
sudo update-initramfs -u

As a possible alternative, you can try to add the options to the kernel line (I haven't tested it myself, but it seems to work for settings like i915.modeset=1. Edit /etc/default/grub and find the line with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash". Replace it by something like:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash thinkpad_acpi.fan_control=1"

To get a list of options for a kernel module:
modinfo -p thinkpad_acpi

This did not work for i915, for that I had to run:
modinfo i915 | grep ^parm

To get the current value of a module parameter, run:
sudo cat /sys/module/MODULE/parameters/PARAM

For the fan_control parameter of the thinkpad_acpi module, you have to run:
sudo cat /sys/module/thinkpad_acpi/parameters/fan_control

If this function returns an error, check if the module was loaded and whether the option exist or not.
Comment: How to know a parameter of module have took effect ? thanks
Comment: @waterloo2005: You can use `/sys` for that. See the revised answer.
Comment: I find I do not add parameter in /etc/modules. I only need to add them in /etc/modprobe.d/ .
Thanks
Comment: The distinction between `/etc/modules` and `/etc/modprobe.d`: the first applies to modules loaded in the early stage of boot (right after Plymouth starts), the latter is loaded later (by initscripts)
Comment: Where can I find official instructions about it ? thanks
Comment: I found it out by analysing the source code, you can confirm that modules in modprobe.d is loaded as initscript in `/etc/init/module-init-tools.conf` and `/usr/share/initramfs-tools/scripts/functions` line 339 (`load_modules`, this script is called from `/usr/share/initramfs-tools/init` which is copied into a initrd). Manual pages: `man mkinitramfs`, `man modules`
Comment: 'sudo cat /sys/module/thinkpad_acpi/parameters/fan_control' gives me 'N' .  How to open this function ?
Comment: What do you mean by "open"? Make it 1?
Comment: Which function? Fan control? What do you want to achieve?
Comment: Yes , I mean if I need to add 'echo Y > /sys/module/thinkpad_acpi/parameters/fan_control' in my rc.local to make it work.
Comment: Have you added `thinkpad_acpi fan_control=1` to `/etc/modules` and executed `suo update-initramfs -u` afterwards?
Comment: Thanks, A few days ago I install ubuntu11.10 . And forgot to add the line to /etc/modules. Now cat /sys/module/thinkpad_acpi/parameters/fan_control gives Y.
Answer: Setting module options using files in /etc/modprobe.d/
Files in /etc/modprobe.d/ directory can be used to pass module settings to udev, which will use modprobe to manage the loading of the modules during system boot. Configuration files in this directory can have any name, given that they end with the .conf extension. The syntax is:
/etc/modprobe.d/myfilename.conf
---------------------------------------------------------
options modname parametername=parametervalue

For example:
/etc/modprobe.d/thinkfan.conf
---------------------------------------------------------
# On ThinkPads, this lets the 'thinkfan' daemon control fan speed
options thinkpad_acpi fan_control=1

Source:Kernel modules - ArchWiki

As far as I know, you can use the mentioned method for modules that are automatically loaded at boot time (to avoid unloading and reloading modules with special parameters, as this might be the case for driver modules), and the /etc/modules file for modules that are not automatically loaded at boot time.
Answer: With Ubuntu 16.04 one can no longer include kernel module parameters in /etc/modules. An error is generated in the boot log saying it can't find "my_kernel_mod myparam=x".
Instead one needs to put only the kernel module name in /etc/modules and put the options in /etc/modprobe.d/myfilename.conf (as suggested above).

How to add kernel module parameters?


Perturbations in FRW metric

Question: Considering the FRW metric with perturbations; how can I calculate the Einstein tensor (without a very very disgusting expression which comes from the variation of the difference between the Ricci tensor minus the metric tensor times the curvature)?
Comment: Have you read anything on the cosmological perturbation theory? What "disgusting expression" you don't like?
Comment: The disgusting expression is the straight forward try to solution- $\delta (R_{\alpha \beta}-g_{\mu \nu} R)$
Comment: Sorry, but that doesn't tell me anything about your standards of beauty=) neither about how exactly you tried to perform those perturbations and how far have you simplified that expression. Usually in the cosmological perturbation theory you separate different transverse and longitudinal components. So again, have you read anything on that? There are textbooks and lectures available...
Answer: The problem concerns standard gravitational perturbation theory. Instead of expanding around say Minkowski space, one expands around the FLRW background.
Using the gauge symmetries and scalar-vector-tensor decomposition, one can reduce the form of the perturbed metric to an incredibly simple form, namely,
$$g_{\mu\nu} = g^{\mathrm{FLRW}}_{\mu\nu} + h_{\mu\nu}= a(t)^2 \begin{pmatrix}
1+2\Psi & 0 & 0 & 0\\
 0& 2\Phi -1 & 0 & 0\\
 0& 0 & 2\Phi -1 & 0\\
 0&  0& 0 & 2\Phi -1
\end{pmatrix}$$
One approach to finding the Einstein equations is noting to first order $\delta R_{\mu\nu} = -\frac12 \Delta_L h_{\mu\nu}$ where $\Delta_L$ is the Lichnerowicz operator. Alternative, one can in this case simply plug in the perturbed metric.
Defining the Hubble parameter, $\mathcal H = \dot a a^{-1}$, we have $G_{00} = 3\mathcal H^2 + 2\nabla^2 \Phi - 6\mathcal H \Phi'$. The spatial part mixed with the time component is,
$$G_{0i} = 2\partial_i(\Phi' + \mathcal H \Psi)$$
and finally the spatial part - the messiest - is,
$$G_{ij} = -(2\mathcal H' +\mathcal H^2)\delta_{ij} + \partial_i \partial_j (\Phi - \Psi)$$
$$ + \left[\nabla^2 (\Psi - \Phi) + 2\Phi'' + 2(2\mathcal H' + \mathcal H^2)(\Phi + \Psi) + 2\mathcal H \Psi' + 4\mathcal H \Phi' \right]\delta_{ij}.$$
Compared to the perturbation equations in full generality, even with gauge fixing, this is a relatively manageable expression.
It can be further simplified depending on the scenario. Ignoring anisotropic stress, $\Phi = \Psi$ which greatly reduces the equations and in some instances gives us only a Laplace equation to solve.
The situation doesn't get any better than this. In fact, having done perturbation theory of solutions to string theory, I can say the situation can be a lot worse. General relativity is horrendously non-linear, there's no avoiding that.
Comment: Well, as you mention scalar-vector-tensor decomposition would be good to als onote that here you consider only scalar sector and omit gravitational waves
Comment: Just in case, I know, they decouple at linear level. Simply saying the tensor perturbations exist too=)
Comment: @OON Yes, didn't want to scare the OP any more :)
Comment: And $\delta G$ is the difference between the perturbed G and the unperturbed one?

Perturbations in FRW metric


Ubuntu 13.04 stuck on the home screen and not able to display any wallpapers and have problem closing down the appplications

Question: I upgraded from 12.04 to 12.10 then on the same day to 13.04. The up-gradation happened successfully from 12.04 to 12.10 but while from 12.10 to 13.04 everything happened fine until the system got restarted. Unity is gone as well as not able to make any changes in the wallpaper, also most of the times the application gets stuck when I try to close it down. Trying to get icons display but am not able to.
 Tried using system settings but to no avail. Referred to the article Unity does not start in Ubuntu 13.04. But no changes in the system. Compiz is also not being very useful and does not do anything now. Need help. Thanks in advance for your thoughts.
My systems configuration -  core i5 2320 3.00 GHz 64 bits Architecture
Comment: Could you specify which graphic card do you have?
Comment: i dont have a graphic card installed
Comment: How do you use a graphical environment then?
Comment: i use the default. Unity is not working and for tweaking I use compiz.
Answer: It seems like you did a messenger game upgrade. If so, you can backup your personal files and start over with a clean install.
Comment: Any other options apart from clean install?
Answer: First thing, did you use proprietary drivers? If so, you had to purge them before upgrading to don't experience issues, purging them now should solve the issue if this is the case.
If you didn't installed proprietary drivers you can try to re-install core packages that seem to be broken and reconfigure Xserver, assuming you have access to a terminal with internet connection, run these commands:
sudo apt-get update
sudo apt-get install --reinstall ubuntu-desktop
sudo apt-get install  unity sudo apt-get install xserver-xgl
sudo dpkg-reconfigure xserver-xorg

Now if your problem still persists you can try a last shot, reinstalling Xserver:
sudo apt-get install --reinstall xserver-xorg

If none of these worked, you'd better backup your files and do a clean install.


When the velocity on both $x$ and $y$ axes change with respect to time, can the movement of an object called projectile motion?

Question: In many books, I see projectile motion caused by gravity when the object is in a state of free fall, so the velocity on the $y$ axis changes with respect to time and the velocity on $x$ axis is constant. But when the velocity on both the $x$ and $y$ axes change with respect to time, can the motion still be called projectile motion?
Answer: An example of the type of motion you mention is the projectile motion with air resistance taken into account. In this case both vertical and horizontal components are functions of time.
So this type of motion is of course possible and it is actually closer to the real behavior of a projectile.
Your question is about the name of this type of motion. The name is just a matter of convention. If you look up "projectile motion with air drag" you will see that it is pretty common to call this motion "projectile motion".
So I would say that you can call it without danger of using an unusual terminology.
Answer: Yes, it could be. The choice of axes is arbitrary.
Comment: +1, but it might be helpful to explicitly point out a simple example — like where you just rotate the axes a little bit, so that the force of gravity has both $x$ and $y$ components.
Answer: Yes and no. Projectile motion occurs when a single constant force is applied to a moving object. The force must be constant in magnitude as well as direction.
It is convenient to decompose the motion about two axes, one along the force and one perpendicular in order to simplify the solution, but you don't have to.
The resulting motion is a parabola, which we call projectile motion. The solution in vector form is:
$$ \boldsymbol{a} = \frac{1}{m} \boldsymbol{F} $$
$$ \boldsymbol{v} = \boldsymbol{v}_0 + \boldsymbol{a}\,t $$
$$ \boldsymbol{p} = \boldsymbol{p}_0 + \boldsymbol{v}_0 \,t + \frac{1}{2} \boldsymbol{a} t^2 $$
If along a particular direction the force (and hence the acceleration) is zero, then the position along that direction would be a result of constant motion.
Comment: I take the OP to just mean that the velocity in the x-direction is changing rather than being constant (i.e. a horizontal force is acting on the object). It seems like you take it more to mean you take the basic projectile motion and then rotate your axes so that gravity has a component in both directions. Am I understanding your answer correctly?
Comment: @AaronStevens - yes, because the two scenarios are equivalent. Put a horizontal constant force in the regular projectile and it acts like a single (combined) force acting in a skew dimension. This would be consistent with my answer which describe the _necessary_ conditions for projectile motion.
Answer: Combining the answers of Chase Ryan Taylor and nasu:
Physicists usually consider coordinate systems a matter of choice, being unrelated to what actually happens, and only useful in describing and analysing it conveniently. Therefore the same "classic projectile motion" could be viewed from a coordinate system rotated with respect to the one usually used for this problem: for example the x axis could be paralel to the initial velocity of the projectile, or point in any arbitary direction. One could even use a 3D system (though this would usually be of little use (expect perhaps as  a vector manipulation exercise))
However, interpreting the question the way you probably meant it (that the y axis is paralel with the local gravity vector, while x is perpendicular to it, being horizontal) the answer is still yes. If there is a horizontal force acting on the projectile so it is decelerating in this direction, it is still useful to label it "projectile motion", since this motion is also observable in projected (launched) objects (which move in some fluid)
Answer: The necessary sufficient and only conditions for projectile motion to occour are-:
1)Velocity should remain constant along one of the axis
2)A constant acceleration must act along or opposite to the other axis.
Hope that answers your question.
Comment: [citation needed].
Comment: In case of air resistance the acceleration becomes a function of velocity and the equation of trajectory no longer is parabolic. What the textbooks mean by projectile motion is a parabolic trajectory.If there is acceleration (no matter whether it is constant or not) on both the axis instead of just being on 1 axis the trajectory of particle deviates from being parabolic. U can check it for yourself by taking constant accelerations a and b on both axis and writing the equation of trajectory. It won't be parabolic.
Comment: I have seen (French) textbooks speaking of projectile motion in presence of friction, and showing it is not parabolic.
Comment: The english Wikipedia page on [projectile motion](https://en.wikipedia.org/wiki/Projectile_motion) agrees with your terminology, so I withdraw my (implicit) critics. It seems to be a country dependent terminology problem.
Answer: If you want to change the $x$ component of your velocity you would need to go in a different world. Anyway if you can do this we have three cases. The $x$ component becomes 0 before falling creating an increasing slope projectile  it will fall of straightly after achieving zero velocity. Now it still has some deceleration on $x$ axis before falling to ground. Then it'll back off to it's throwing point same as a projectile. If it does fall before the $x$ velocity being zero then it'll be still a projectile. But while falling it'll have great slope. And through out it's journey it's slope will gradually increase. Now about equations if I think that gravity also acts in $x$ axis. $x= v\cos\theta t -gt^2/2 $ and $y= v\sin\theta t- gt^2/2$ $y-x= vt (\cos\theta -\sin\theta)$ so it's a straight line whose slope increasing or decreasing with the value $\theta$ with time.It also seems if $\theta = 45° $ then it'll get back to it's throwing point .
Comment: The OP does not specify what force is changing the x-component of the velocity. It definitely is not gravity though.
Comment: @AaronStevens: it could be gravity, if you do not neglect Earths curvature. Of course, neglecting friction and not neglecting planetary curvature implies quite literally you're on another world ;-)


How to increase text size on Lubuntu?

Question: My O.S. is Lubuntu 12.04. And I'm having some problems to read the text of my screen, because it appears very small. I've read How to increase text size?, but it only explains how to increase text size in Ubuntu and as Lubuntu uses another desktop environment I'm not being able to follow that question.
Answer: Tutorial

Go to Lubuntu Menu > Preferences > Customize Look and Feel

To change the Default Font:

To change the Title Bar Font:

After customizing the settings the way you want just click "Apply"
Comment: I've followed these steps, and set all of these to a very distinctive font, but the desktop, the start menu, and application fonts (eg nvidia-settings) fonts are all unchanged.
Comment: How to do it in Lubuntu 20? I cannot find this menu on this version
Answer: looked for a way to change the panel's font size the only thing that was available is the
lxpanelctl config
but when i came to change the font size it only gets up to 20 ( which is nearly enough on big screens ) so found the xml file related :
sudo gedit /usr/share/lxpanel/ui/panel-pref.u
after editing this file and changing the 20 parameter to 100 (just serach for 20 and you'll see it),
i was able to go back to the lxpanelctl config and up the font size to what was best for me
Answer: In addition to the accepted answer:

Right-click the desktop, go to Desktop Preferences > Appearance and set the "Font of label text" there.
Right-click the Panel (Application/Start Bar), go to Panel Settings > Appearance and set the Font size. This one only goes up to 20, but it's much better than before.

How to increase text size on Lubuntu?


Is there anywhere I can download the new USGS Topo TIFS?

Question: Is there anywhere I can download USGS Topo TIFS?  The new ones?  The USGS site just gives me GeoPDF and their web service restricts the scale you can see them at.
Edit : I am looking for the the new USGS Topo maps (c 2012).
Answer: The Libre Map Project (through archive.org) has the digital DRGs (tiffs) for all 50 states for free. Only thing is, they are still collared. Go to the Data section for a state and there is a link on the top for the DRGS, here is Ohio for example.
Comment: Not the same product the OP is asking for. Good source of data though.
Answer: GDAL can read the pdf and make it an image format. http://www.gdal.org/frmt_pdf.html
GlobalMapper will do the same.
The national map allows you to download the imagery (USTOPO uses NAIP).
http://viewer.nationalmap.gov/viewer/
Comment: Is the GDAL output PDF georeferenced?
Comment: On the page it states "GDAL supports reading Geospatial PDF documents, by extracting georeferencing information and rasterizing the data." So my assumption is yes.
Answer: ESRI offers the seamless USA Topographic base map, freely through a Map Service named USA_Topo_Maps. As you zoom-in, more detailed maps display. The 7.5 minute quads or 1:24000 scale are the most detailed.