What are the criteria for identifying an allusion?

Question: Two recent questions have me wondering whether there are good criteria for identifying an allusion in a biblical text. An allusion seems to be a deliberate reference to another text, albeit in a hidden way. That is, it's meant to call something to mind, but without an explicit reference as in a quotation. The hidden nature of an allusion obviously adds some difficulty to the detection, but are there good criteria that can be used so that the process of detecting an allusion doesn't fall into the pit of subjectivity?
Answer: Christopher D. Stanley says in As it is Written, pages 30-31, the term 'allusion' is used for a figure of speech that makes indirect extra-textual references but has been and remains notoriously difficult to define in specific terms. He cites C. Hugh Holman in A Handbook to Literature, one of the standard handbooks of literary study, as defining allusion such as to include several significant elements:

reference may be to historical or literary entities, including people, events, or objects;
the reference is indirect, as opposed to quotation or paraphrase, both of which are direct;
the allusion is intentional on the part of the author towards the reader;
allusion may occur without the knowledge of the reader;
allusion is most effective when there is a body of shared knowledge between the author and reader

Probably the one element in this that I would first look for, in deciding whether an allusion is present, is whether there is a an intent on the part of the author, then whether there is likely to be a body of shared knowledge between the author and reader.
Stanley also discusses an almost synonymous term, 'echo', which he sees as lacking the specificity of an allusion, but is reserved for language that is thematically related to a more general notion or concept.
Comment: Yes, it as all about "authorial intent"and  reconstructing mental states in what is often nothing more than a hypothetical author is a completely subjective process. In regard to linguistic "evidence" i.e. use of language from the Hebrew/Greek bibles doesn't constitute an allusion. Take for example John of the Apocalypse, his mind is thoroughly saturated with OT language. His narrative is construed with building blocks from OT sources, Theodotian, H-MT, LXX, with Daniel, Isaiah, Ezekiel ... there are genuine allusions but often the OT language is just the way he expresses his ideas.


Why are there restrictions for women in Hindu temples (in general)?

Question: I am here talking in general & not related to a specific temple or place. Why are women not allowed to touch an idol of God or come near it? Is it related to their menstrual cycle? If so, why is it considered impure because of it?
Comment: Related [Why women are not allowed to enter sabarimala?](http://hinduism.stackexchange.com/q/10116/3500) , [Why women are not allowed to offer prayers at Shingnapur Shani Temple?](http://hinduism.stackexchange.com/q/9661/3500) and [Why are menstruating women (at least in the Brahmin community) asked to be separate from the family for three days?](http://hinduism.stackexchange.com/q/8/3500).
Comment: Somewhat similar question [References from scriptures about prohibition of menstruating women from temples, pujas etc](http://hinduism.stackexchange.com/q/10132/3500)
Answer: During menses women are said to have an "irreversible religious impurity".
So it means, no matter what they do (like bathing, or achamana etc) they can't purify themselves in those days.
That's why their visit to temples or worshiping are considered  futile and hence the restriction.
A same kind "irreversible religious impurity" also applies during the period of "Osaucham" to the members of a family where a death (or birth) has taken place.
Members of that family during that period are also prohibited from participating in any kind of religious activities irrespective of whether  they are male or female members.
And, of course the question "why such impurity occurs?" can't have rational answers.
Comment: @Ankit Sharma: What's Osaucham?
Comment: @Varun Krish Asaucham (or Ousacham) is a religious impurity that occurs when somebody dies in a family or even when a birth takes place.When someone died its(the impurity) called-Mritakam  and if someone is born its called-Sutakam.In both cases the family members are prohibited from performing religious duties/activities like Puja etc.
Comment: @VarunKrish I don't know. I am just an editor, ask Rickross.


What causes the localization of myoglobin in turkey to regions of muscle tissue?

Question: I've read that myoglobin localization is responsible for the darker colour of leg muscles in turkeys. Why does this localization occur in terms of any of cell biology, molecular biology, or biochemistry? I'm not looking for bigger picture explanations at the levels of physiology or evolution, although I understand that they'll be connected to this question.
Answer: "Localization" is probably the wrong term, but I think I know what you mean... It more has to do with "expression."  While the exact mechanism to my knowledge is not elucidated, it has to do with the type of motor neuron innvervating the fiber.
This has been demonstrated by studies where they cross-inervated; that is, they took the neurons which usually innervate Type I muscle fibers and innervated Type II muscle fibers with them and vice versa.  The Type I fibers took on fast glycolytic properties, whereas the Type II took on the slow oxidative features (such as higher levels of mitochondria and myoglobin that you're talking about).

Source:
Sherwood L, Kell R. Human Physiology, First Canadian Edition. pp. 282-283.
Comment: "Localization" refers to describing, predicting, or determining the location where something is or occurs. It can also refer to the fact that something is located in particular places. I am referring to the description of where myoglobin typically occurs in turkey muscle tissue.
Comment: I'm mulling your answer over. That's quite interesting.
Comment: I think it qualifies as an answer mainly under cell biology. I'm accepting it.
Comment: Yeah it's just at least in cell bio when we talk about "localization" of a proteinusually we're talking about where it's moved to; the point of the distinction that I was making was that it's not that the myglobin is produced ubiquitously and then localized in certain cells; it's expressed at higher levels in certain types of muscle tissues.  Just semantics; sorry.
Comment: That is semantics, but it is not just semantics. That is jargon within a specific domain. That jargon applies to this context, so I understand your desire to use it here. However, the existence of applicable jargon in a particular domain doesn't invalidate the use of more generic usages. Jargon is a fine tool, but not the only hammer. There's no universally accepted rule for deciding whether to use generic vs domain-specific language, though opinions abound, so I'm sympathic to your clarification.


Retrieving earlier Chrome bookmarks

Question: In preparation for performing a clean install of Windows 7 32-bit, I took an image backup of my existing Windows XP SP3 hard drive. The clean install did away with all my Chrome bookmarks, of course. Is there a way to retrieve the old bookmarks I had in XP? What files would I access in the image backup? And how can I import them into the Windows 7 Chrome bookmark file?
Answer: In Windows 7, your Chrome profile should be located at \Users\{username}\AppData\Local\Google\Chrome\User Data\Default 1. Inside that folder, there should be a "Bookmarks" file. If you have not created bookmarks in the Chrome profile in your clean installation, you could directly overwrite the file in the new profile with your backed up copy.
[1]: See http://dev.chromium.org/user-experience/user-data-directory for information on where Chrome profiles are located in all operating systems.

Retrieving earlier Chrome bookmarks


Is there any water in a korban minchah?

Question: The Maharal (Gevuros Hashem, ch. 48) proves that matzah ashirah is considered matzah from the fact that the korban minchah is called matzah even though it is made with oil. But in the continuation of his discussion, he says that obviously if there is no water in the matzah, it is not matzah at all, (because it cannot become chametz). Does a korban minchah have any water in it?
Answer:
כל המנחות נילושות בפושרין, ומשמרן שלא יחמיצו.
  "All the menahoth are kneaded with lukewarm water..."

מנחות ה,ב, Tractate Menahoth 5:2
This is codified in the Rambam as well (מעשי הקרבנות יב:כא):

כל המנחות הנאפות נילושות בפושרין ומשמרן שלא יחמיצו. הואיל ולישתן ואפייתן בפנים בעזרה אנשי פנים זריזין הן:
Comment: Hello @loewian, and welcome to Mi Yodeya! You could make your answer even more useful by translating and explaining your source, as we try to cater to the largest audience possible. Thanks, and I hope to see you around the site!
Answer: These class notes are on the Sefer HaChinuch Mitzvah #116.

It requires the cohanim to bring minchah sacrifices according to the
  required procedures.  M'nachot were sacrifices consisting of flour,
  sometimes with oil and sometimes with water, and sometimes with
  frankincense.

For a minchah al machvat, water is added and the dough is kneaded.   The person doing the kneading needs to keep kneading it so
  that it does not become hametz.   The dough is formed into cakes and
  placed on a pan that looks something like a cupcake pan turned upside
  down.  The cakes are then placed over heat so that the cakes fry in
  the oil.
A minchah al marcheshet is the same as a minchah al machvat except that the cupcake pan is right side up and the dough is placed
  in the cups.
"Challot" are m'nachot baked in an oven.  All of the necessary oil is added during the first mixing process.  Then water is added and
  the dough is kneaded.  The cakes are baked on the bottom of the oven.
To make "r'kikin" the flour is mixed with the little bit of oil added at first and with water.  Then it is kneaded, made into
  cakes and baked.  After that, the rest of the oil is spread on top of
  the cakes.

So, yes some types of korban minchah have water in them.
Comment: Doesn't look like the Sefer ha-Chinnukh says anything about water but may be so nonetheless http://www.ateret4u.com/online/f_01644_part_116.html

Is there any water in a korban minchah?


Can I connect a Raspberry Pi to the VGA port on my laptop, like a projector?

Question: I have a laptop with a VGA port - can I connect it to a Raspberry Pi using an HDMI to VGA converter, like connecting laptops to projectors?
Comment: Are you trying to use the laptop as a display fro the Pi?  If so is the laptop VGA port an input?
Answer: no, the Raspberry Pi's HDMI connector does not allow for input, try looking at USB dongles that accept video and work with the Pi.
What exactly are you trying to capture?
Answer: Depending on what your laptop is running and how much effort you want to put into it you can tunnel X which allows you to display applications on a different computer than the one they're running on.
I've had some success on both linux-to-linux as well as linux-to-windows. If you really want to get fancy you could actually get a network crossover cable that allows you to create a system-to-system network so you could just connect your laptop and your Pi directly.
Alternatively you could also use something like TinyVNC which should run pretty quickly in this scenario.


How do you make a mortise and tenon joint using hand tools?

Question: I only have hand tools available to make a mortise and tenon joint, could someone please tell me how to do this? Thank you
Answer: Have you got a mortise chisel among your hand tools? If not, you'll have a miserable time. If so, you use your marking gauge to scribe a tenon the width of your mortise chisel, and cut that out with your backsaw (or preferably your tenon saw, which is a smallish backsaw of the rip persuasion) and you scribe around the mortise, then chop it out with your mortise chisel, which is a stout and sturdy beast made to take some serious pounding.

Some wimpier chisels are (mis-)labeled as mortise chisels in the modern trade. One like this will run rings around them.
If need be you use a plane or paring chisel to make fine adjustments to the tenon for fit.
Comment: Chopping a mortise with a normal bench chisel works just fine.  I've cut dozens of them with no problems whatsoever.  They actually make it easier in some ways, as you can use them to crosscut the waste and lever it out more easily.


What metal is along the top of a plaster wall in a 1930s house?

Question: I have a house built in the 1930s with lath and plaster walls. I was planning to install a hook, so I needed to find a stud. My normal stud finder didn't work (as expected), so I used some rare earth magnets. However, I found that there is about 3-4 inches of something metal all along the top of the wall. This seems to extend to every wall on the floor. I am fairly new to this era house - what could be along the top of all the walls that would be made of metal?
Comment: Likely a metal corner.
Comment: Would a metal corner run along all walls? What is the purpose of a metal corner?
Comment: does it extend to the ceiling?
Comment: google `metal lath plaster picture`
Comment: It goes from the ceiling down a few inches. If it was metal lath plaster mesh, I would think it would extend all the way down, no?
Answer: It is likely to be "drywall bead " used to make joins between plasterboard at internal an external corners. It makes it easier for builders or renovators to produce a clean sharp corner.
Comment: Looking at the dimensions of where the metal is (via magnet), this looks about right. Thanks!


Thyroid Peroxidase (TPO) Ab Test- normal or abmormal

Question: I had a variety of test ran on my thyroid and I'm waiting to see the DR. My question is the TPOAb reference rang is 0-34. Mine came back as 9 IU/ml. Is this still considered normal or abnormal? I also have a family history of HyperT and HypoT (not sure if that matters) Thanks.
Comment: Thank you for your post and welcome to Health SE! However, post asking personal medical advice are not usually accepted on the site as we do not have the resources to answer them completely and they are very important as they regard your health. Consulting the proper medical authorities would be the best course of action for you and I am sorry that is all we can do. Thank you!
Comment: Ok....Thanks. Let me see if I can rephrase my question. If a reference range is 0-34, Would 9 be considered negative? (Not sure if its allowed this way) I do see my DR in a few days.
Comment: Not sure what your asking, but as long as its not refering to anyone specific you should be fine. All I and my phrases should be avoided. We can evaluate the question again after editing and if it's within guidelines you should be all set.
Answer: Normal. A result of 9 where the reference range is 0 - 34 indicates that you're within the normal range. For this test, an abnormal result would be a value over 34 because it's not possible to have a result below zero.
Keep in mind that each testing lab can different reference ranges, and they can differ over time too.


Restrict list view visibility to a group

Question: Is it possible to restrict the visibility of a globally visible list view to a group of users. I want certain users not to see several list views that are shared to every user in the system. Thanks in advance.
Answer: If they are global, then you can't. I suggest you edit them and change the global view to one where you select the viewers (leaving out the people/groups who shouldn't have access.
Answer: I think only way is removing "Manage Public List Views" permissions on the profile coz profile permissions will be taken high priority. For more details you can refer to
https://help.salesforce.com/HTViewSolution?id=000187425&language=en_US


Would I have to use a new paint tray liner after only one day of I left it out overnight?

Question: I painted a wall yesterday (blue) with a new roller, pan, and liner. I wrapped the roller in a plastic bag and there was minimal residual paint in the tray. I left it out over night. I put paint in the same pan this morning and noticed as I rolled it onto a portion of the wall that it was a bit whiter than the old coat. I don't remember if it was quite that white when it went on originally. Could this be just because I'm applying the paint onto the new color and not a white wall or is it more that I should have cleaned the liner, or even that I should have replaced the roller? I tried a fresh roller and seemed to get the same response. Heck, maybe I just need to put some more elbow grease into stirring the paint. Any tips? Thanks
Answer: Your suspicion is correct. You've rolled a second coat, which often makes color more bold or intense.
It's common practice to wrap trays, rollers, and brushes as a set overnight. It's not a problem.
Comment: Thanks for the help. I really wasn't sure and I didn't want to assume. A few hours later and it evened right out.
Answer: Fresh paint being applied is usually a slightly different color than a dried coat.  You notice the guy at the hardware store hits his paint sample with a hair dryer before comparing it.
I half wonder if paint companies do this deliberately as an aid to the painter, to help you distinguish dry from wet.
It will also be a different sheen, as most architectural coatings are flattish and wet paint will be a high gloss.
Also, I have never met a pastel that is opaque on the first coat (and almost all architectural coatings are pastels).  If your previous color is at all dissimilar, the second coat will cover better and the old color will bleed through less, which will appear as (and actually be) a change of color.


Prediction Intervals with Heteroscedasticity

Question: I am using R to perform linear regression.  I have seen ways to calculate prediction intervals, but these depend on homoscedastic data.  Is there a way to calculate prediction intervals with heteroscedastic data?
Answer: Nonparametric quantile regression gives a very general approach that allows for both heteroscedasticity and nonlinearity.  See section 9:  http://www.econ.uiuc.edu/~roger/research/rq/vig.pdf
UPDATE:
A reasonable approximation for a 90% prediction interval is the space between the 5th-percentile regression curve and the 95th-percentile regression curve.  (Depending on the details of the curve estimation technique and the sparsity of the data, you might want to use something more like the 4th and 96th percentiles to be "conservative").  Intuition for this type of nonparametric prediction interval is here on wikipedia.
This answer is just a starting point.  A significant amount of work has been done on quantile regression prediction intervals. Or just make nonparametric regression prediction intervals.
Comment: True, but how do you get prediction intervals in quantile regression?
Answer: It would depend on the nature of the heteroskedasticity.  If you wanted a prediction interval, you usually need a parametric specification like:
$$
y_i \sim N(\mathbf{x}_i'\beta,\sigma_i(\mathbf{x}_i,\mathbf{z}_i ))
$$
i.e. $y_i$ is normally distributed with mean $\mathbf{x}_i'\beta$, and standard deviation $\sigma_i(\mathbf{x}_i,\mathbf{z}_i )$, where the standard deviation is some known function of the $\mathbf{x}_i$ or perhaps some other set of variables $\mathbf{z}_i $ , that way you can estimate the standard deviation for each $i^{th}$ observation.
Examples of possible functions include; $\sigma^2_i(\mathbf{x}_i)=\sigma^2x_{i,k}$  (Studies of firm profits, an example from Greene's "Econometric Analysis" 7th edition CH 9), where $x_{i,k}$ is the $i^{th}$ observation of the $k^{th}$ dependent variable, or, if working with time series data, GARCH and/or stochastic volatility specifications.
You can use the estimates $\hat \sigma_i(\mathbf{x}_i,\mathbf{z}_i )$ as the standard errors for your prediction intervals if you like.  I will forgo a formal treatment here because accounting for estimation errors in  $\hat \sigma_i(\mathbf{x}_i,\mathbf{z}_i )$ can be complicated but, with a sufficiently large sample, ignoring the estimation error does not effect the prediction interval that much.  In short, it is not necessary to open that can of worms here. For a more detailed explanation of all this and more examples, see Wooldridge's book "Introductory Econometrics: A Modern Approach", Ch 8.
The problem is that when people refer to heteroskedastic or "robust" regression, they are usually referring to the situation in which the precise nature of the heteroskedasticity (the function $\sigma_i(\mathbf{x}_i,\mathbf{z}_i )$)  is not known, in which case a White or two-step estimator is used.  These offer consistent estimates for $var(\hat \beta)$ but not for the $\sigma_i$, and so you have no naturally way to estimate prediction intervals.  I would argue that prediction intervals are not meaningful in this context anyway.  The idea behind these sandwich type estimators is to consistently estimate the standard error of the coefficients, $\hat \beta$, without the burden of offering accurate prediction intervals for each individual observation, thus making the estimates more "robust".
Edit:
Just to be clear, the above only considers least squares regression.  Other forms of non-parametric regression, such as quantile regression, may offer means of obtaining a prediction interval without parametric specification of residual standard error.
Answer: If the regression of your response on your explanatory variable is a straight line and your variance increases with the explanatory variable, a weighted regression model is needed with  or  (if your nonconstant variance is more extreme) as your weight. This weights your variance by your x value, so that there's a proportional relationship.
Here's code with the weights included in the model and prediction. Notice that you need to add the weights to both your original dataset and your new dataset.
Thanks to @PopcornKing for his original code from  Calculating prediction intervals from heteroscedastic data.
<code>library(ggplot2)
dummySamples <- function(n, slope, intercept, slopeVar){
  x = runif(n)
  y = slope*x+intercept+rnorm(n, mean=0, sd=slopeVar*x)
  return(data.frame(x=x,y=y))
}

myDF <- dummySamples(20000,3,0,5)
plot(myDF$x, myDF$y)
w = 1/myDF$x**2
t = lm(y~x, data=myDF, weights=w)
summary(t)

newdata = data.frame(x=seq(0,1,0.01))
w = 1/newdata$x**2
p1 = predict.lm(t, newdata, interval = 'prediction', weights=w)
a <- ggplot()
a <- a + geom_point(data=myDF, aes(x=x,y=y), shape=1)
a <- a + geom_abline(intercept=t$coefficients[1], slope=t$coefficients[2])
a <- a + geom_abline(intercept=t$coefficients[1],   slope=t$coefficients[2], color='blue')
a <- ggplot()
a <- a + geom_point(data=myDF, aes(x=x,y=y), shape=1)
a <- a + geom_abline(intercept=t$coefficients[1], slope=t$coefficients[2],  color='blue')
newdata$lwr = p1[,c("lwr")]
newdata$upr = p1[,c("upr")]
a <- a + geom_ribbon(data=newdata, aes(x=x,ymin=lwr, ymax=upr),   fill='yellow', alpha=0.3)
a
</code>


Can I fly with my friend on the outbound flight, if we have a separate return flight?

Question: I'm travelling somewhere with a friend, but would like to return on a separate date than my friend. For that reason I suppose I need to buy the tickets together. Is there another way to do that?
Comment: Depending on the airline, you maybe able to pick your seats in advance, so just pick ones next to each other.  If that option isn't available, you can ask the airline to tie the reservations together, which might help.  If all else fails get to the airport early and hope the check in agent can assign you two seats together.
Comment: Not sure why you think you need to "buy tickets together", just because you travel together one way.  The airline will treat the different return dates as reason for separate bookings/tickets.
Comment: I agree with @Tom, and even if you don't sit together, you can still check-in together if you wish for the flight that you're taking together.
Comment: Well, I had been hoping to sit with my friend on the way...
Answer: You can, from a travel agent or by phone to the airline (or at a ticket desk). However, the "PNRs" [passenger name record---the database record of your journey] will be split anyway so you and your friend will be on separate bookings. It is not possible for a single PNR to contain different flights for different people.
The PNRs can be "linked" together so that theoretically if one of you is moved out of your seat the airline know that you are travelling together, but to be honest it doesn't really achieve much and is not a reliable system. You can also ask to link your PNRs after you buy them separately.
Frankly I would not bother, just buy your tickets separately and then arrange to sit together when you choose your seats.
Answer: In the process of flying, there are different steps. The first is the booking, but there are others, mostly checking in and boarding.
If you want to fly with your friend, when booking a flight, you should make sure you book the same flight (i.e. same day, same time, and usually same flight number). At least you will go to the airport at the same time and will fly on the same plane.
For most airlines (all the flights I ever flew), the choice of seats is relatively independent from the booking. There are multiple times it can be possible to pick a seat (at booking actually, between booking and check-in, and at boarding), but the most common is at check-in. At that time, a large share of seats are available. So if your only goal is to sit together, be the first to check in. It could be an online check-in, 24 hours in advance or sometimes earlier, or at the airport (if online check-in is not available).
On a close topic, there are now services that offer to friends who want to fly together (but on the same entire itinerary apparently, so this is not for you) to book together but split payment properly. There is a question on that topic.


Can i travel to Spain?

Question: I was recently deported from the United States. I overstayed there without a visa for a long period of time, I was arrested last year and charged with 6 felonies but all my charges ended up getting dismissed & i was not convicted of anything, but due to my immigration status i was deported back to my home country. I would like to know if i am admissible to travel to Spain? I have a family member that lives in Barcelona and offered me to go stay with her. I have a Honduras passport and have read that it is not necessary to have a visa to travel to Spain for honduran citizens.
Comment: How feasible this is depends on what nation's passport you hold. Do you require a visa to enter Spain? Either way, unless you have a pending job offer in Spain, you cannot stay more than 90 days in any 180 day period.
Comment: The only way to be sure is to apply for a visa if you need one to enter the Schengen area. If you're asked about your immigration history, or the charges you faced (you might be asked if you were **charged** with any offences, in addition to whether you were convicted) you should reply honestly. I wouldn't rate your chances highly, but if you lie and are found out you can be sure of a refusal and probably a lengthy ban.
Comment: Unlike the UK for example, the Schengen visa application form does not ask about non-Schengen immigration history or criminal charges/offences http://www.exteriores.gob.es/ContenidoReutilizable/InformacionParaExtranjeros/Documents/visadoSchengen_EN.pdf
Answer: As a Honduras citizen, you don't need a visa to enter any country of the Schengen area, including Spain. You can stay for a max of 90 days, following the 90/180 rules.
The principal problem you might encounter is that, with a overstay in your historial, and being invited by a familiar to stay with her, the officer at the immigration interview might see you as likely to overstay again, and might deny you entry. To get a better chance of entering, you should bring evidence of strong ties to your country, a good financial situation, and a return ticket.
If, on the other hand, you're planning to stay longer, you'll have to get a residence permit. For that, you need to show that you have no criminal records for 5 years in your previous countries of citizenship, but this shouldn't be a problem, as you were not actually convicted. Note that there are other requisites, and this might not be an easy path even if possible.
Finally, let me echo user90371's comment: if you get asked about your immigration history, tell the officer the truth. Getting caught lying will probably lead to a ban, and many complications in the future.

Can i travel to Spain?


Best potato varieties to use for mashing

Question: I use Maris Piper with butter, milk and seasoning, but I'm wondering if there is a better variety for mashing?
Comment: In the UK, I haven't found a better mashing potato than Albert Bartlett Roosters. But I find any potato works, especially if you use a potato ricer and a dangerous amount of butter.
Comment: I'll be sure to try these ones next time. Thanks for the tip. :)
Answer: The variety of potato used for mashing really is a matter of preference, and the style of product you desire.
Light, Fluffy Mashed Potatoes
The best potatoes for light, fluffy, very smooth and elegent mashed potatoes are starchy varieties, such as the US Idaho.
Dense, Creamy Mashed Potatoes
For dense, creamy mashed potatoes (which also hold longer), a waxy potato like a Red Bliss or a fingerling is more ideal.
Middle of the Road
You can also get excellent results with middle of the road potatoes which are between the starchy and waxy extremes, such as the US Yukon Gold.
Comment: I believe a more specific term for what you are calling "US Idaho" are russet potatoes.
Comment: I invite people to add varieties for other regions besides the US.
Comment: Nearly every county in the world uses different names for the same/similar potato variety. This is unanswerable by name, you need to to use other factors. Like the look and texture of the potato when it is cut and boiled. How do you test for starchy or waxy, what are you looking for? Do all varieties give the same results at throughout the growing season?
Comment: Thanks. Got to say I find that dense and creamy mash tends to sit heavily in my belly, as delicious as it is.


Is this really a good answer?

Question: This answer to this question doesn't seem to seriously address what's being asked, and looks to me like the responder is making a joke (aka a glorified comment). While I don't know much about the finer details of the LOTR series, I can't find myself believing most of what they said, and the comments seem to agree. As of this writing, it has four upvotes, so I was wondering if there was something I'm missing as far as the content or quality of this answer. If not for the positive votes, I'd probably flag it.
Comment: And the answer's score has nosedived since you asked this question. I am now pleasantly un-baffled.
Comment: Now that I've looked at it, I am also baffled. While it probably doesn't qualify for any form of flagging, it definitely should be downvoted rather than upvoted.
Comment: @can-ned_food Which is?
Comment: It appears that this answer was removed. I wish I made a screen grab. Is there any way to get a copy? I can't find it in the wayback machine.
Comment: @Ixrec That was my second option
Comment: I think the essential point is that it is not *wholly* a joke. Answers that are nothing but jokes (even if they could be interpreting as addressing a question) tend to be considered non-answers and deleted (like when someone says that the Flash helped Tyrion get somewhere fast on GoT or something). Answers that are humorous but still seriously address the question (accurately or not) stay up.
Comment: In other words, it looks like a genuine (if humorous and somewhat incorrect) answer, not a mere joke. For example, the bit about the tower collapsing because Sauron built it with the Ring looks like a definite attempt at an answer (and is actually correct).
Comment: @Ixrec The score is back in the positives
Comment: @DCOPTimDowd - And back into the negative again, where it belongs
Comment: Thank you all for your assistance
Comment: When I see these sorts of things, I am reminded of the Wizard's First Rule.
Comment: @DCOPTimDowd: 10k'ers can still see it.  The rest of us will just have to use our imaginations.
Answer: Q. Is it an answer?
Yes.
Is it a good answer?
No.

Why is it a bad answer?
Because it's a bunch of unsourced assumptions, that's why;

which is no longer able to maintain the cohesion necessary to project
  his 'Eye-Form' into our dimension

Says who?

it is assumed he fell the remaining 1.5k (5,000ft) to his death.

"Assumed" by who?

This was caused from the rapid release and detonation of the volatile
  and flammable chemicals being used to maintain the eye-flame,

Huh?

stemming from failure of an O-ring on the anti-backflash device on one
  or both of the nozzles in the 'horns' of the tower used to create the
  effect.

Wut?
Comment: the O-ring / nozzle comment must be a reference to the Space Shuttle Challenger accident - which is.....dark, to say the least.
Comment: Being old enough to remember seeing the only real-world example live, I'm never going to find any passage containing the phrase "o-ring failure" funny. "In bad taste" seems like a gross understatement to me. Anyone at least 20 years old and familiarity with the works for Richard Bachman would probably be equally (well maybe a bit more) disgusted by a supposedly humorous reference to the end of *The Running Man* (the novella).
Comment: That last one gets me every time!
Comment: To offer potential context, this looks like it's from someone who migrated from /r/AskScienceFiction, which has a similar Q&A format, but demands that answers be as in-universe as much as possible.  In the absence of sources, rampant speculation/fan-theories are permitted, so long as it's plausible.  Were this posted on that subreddit, this answer would probably have been well-received.

Is this really a good answer?


Caring for a sealed finish

Question: The walnut table I just finished has one coat of oil based Varathane polyurethane.  In caring for it in the future, is wood oil or any such care product of use,  or will it just float and muddy the surface?
Answer: OK first off one coat of oil-based poly probably isn't enough, but it does depend on what use the piece is put to how much finish does constitute an adequate protective coat. For furniture that sees regular use, handling or wear two full-strength coats should probably be thought of as the minimum necessary for protection (4-6 coats if you're diluting and wiping the finish on).

In caring for it in the future, is wood oil or any such care product of use, or will it just float and muddy the surface?

They are of use in that they can help clean off dust and grime*, and when the finish has dulled they add sheen ....as long as they remain on the surface, but, they're not actually any good for the wood. All manufacturer's claims about how they care for your furniture can be lumped together as hogwash >_<
How should we care for finished furniture?
The primary care step should be regular dry dusting, with wiping using a damp cloth reserved for when the surface is actually dirty (because it is water that will do most to undermine a finish over the years, eventually doing more harm than dust or grime).
Other than dusting the oldest way to care for finished wood I think was waxing and it's still the best option in many ways. Any decent paste wax (like Johnson's venerable Paste Wax in the yellow tins) is a much better option than any spray "furniture polish" that contains oils or silicone.
Note you can easily make your own paste wax at home if you prefer, brief instructions at the end of this Answer.

*But so can a cloth dampened with warm soapy water.
For woodworkers and anyone else who routinely has some mineral spirits (UK: white spirit) or turpentine in the house if a piece gets actually greasy on a regular basis it's much better to degrease the surface with one of these solvents than it is to wash it down with soap and water, it won't harm the finish and you don't risk water getting through to the wood and undermining the finish, particularly at edges or anywhere else it is thin, worn away or otherwise damaged.
Comment: Wish I could upvote this a few more times.
Answer: Finishes do not require "feeding". If you are concerned, put more layers of finish on it now; after that keep it clean and dry and it will do just fine for the next several decades, until it is worn enough to be worth refinishing.

Caring for a sealed finish


How to upgrade storage for Macbook Air?

Question: I'm getting my first Mac, a Macbook Air 2015. My other machine is a PC used for gaming and I thought I could use my external HDD with both. Now I see NTFS is read only in OS X. For now it's unlikely that I'll run out of space on the 128GB SSD because I stream both videos and music and don't save large collections of photos or videos on the notebook but if might need some more space, what would be the best way to upgrade storage? Move the files on the HDD to my PC, format it to another file system and only use it with the Macbook? Does OS X have a utility for that? I heard it's possible to upgrade the SSD but will it void my warranty to have it done?
Comment: Are you looking for ways to add storage by only using the external HDD?  That MacBook has a slot for adding an external storage card and that's how I increased my Air storage.
Comment: Upgrading the internal SSD would be difficult to say the least and would definitely void your warranty.
Comment: Upgrading your internal storage is ***expensive***.  It is not difficult; its about as easy as inserting memory.  It will also **not** void your warranty.
Answer: Your best option is to get a memory expansion module.  I have a 2013 Air and I purchased the PNY 128gb StorEDGE.  It's very fast and would double the available storage on your Air.
As others have indicated, opening the Air to add another/bigger SSD would be more expensive and difficult than just adding an expansion module.
Answer: You can reformat your HDD in FAT or exFAT format (from the Mac or from the PC), so you'll be able to use it with both machines.
BTW the software to use on the mac is Disk Utility, in Applications /Utilities

How to upgrade storage for Macbook Air?


Switch 3550 password default password

Question: What is the Cisco 3550 default password?
I lose the password due some power outage while I was programming.
I did reboot, and try the recovery password but doesnt work.
Comment: Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
Answer: There is no default password. Somebody didn't save the configuration after the last password change. You do a password recovery: Password Recovery Procedures
Specifically, for the Catalyst 3550: Cisco Catalyst Fixed Configuration Layer 2 and Layer 3 Switches
Answer: People sometimes set these up wroth password of cisco or Cisco but there is no out of box default...
1st option start guessing
2nd option... If you have a copy of the config and the password is encrypted with type 5 or 7 enter at this website to get the password.
3rd option is follow the password recovery procedure given by Cisco. Follow it stop by step. I'll put it below.
4th option. If you don't care what's on the switch this may be the way to go from the start. I'll add steps below the recovery

Password recovery my Refrences

After connecting your console cable (9600,8,none, 1) with putty or hyper terminal and test it's "talking" unplug it.
Hold down the mode button and plug switch power in. Release the Mode button after approximately 15 seconds when the SYST LED turns solid green. When you release the Mode button, the SYST LED blinks green.
At the prompt Issue the following commands. Each one followed by enter key.
flash_init

load_helper

dir flash:

rename flash:config.text flash:config.old

boot

(System will reboot and you have a blank config)
Enter n for initial setup

enable

 rename flash:config.old flash:config.text

copy flash:config.text system:running config

config terminal

enable password Cisco (use your password)

enable secret Cisco1  (use your secret)

line vty 0 15

    password Cisco2  (use your telnet password)

    login

line con 0

    password Cisco3  (use your console password)

exit

exit

Write mem

Done with recovery.
If you want to factory reset there are two things that need deleted. Startup config and the vlan database.
Issue these commands and answer no to saving anything.
delete flash:vlan.dat

Write erase

Reload

No to any save questions

Switch will be ready at reboot.

Switch 3550 password default password


Estimation of Two Closely Spaced Frequencies?

Question: What is the best frequency estimation algorithm for two closely spaced frequencies in term of the minimum frequency spacing achieved?
Comment: Under what constraints? I.e. are they the only two tones? How are they sampled? How many samples do you have?
Comment: @MarcusMüller I have the DFT samples, equally spaced , and the two frequencies are distant from other frequencies (higher SNR compared to other tones), not necessarily of the same magnitude.
I'm aware of the trivial 1/T resolution property of the DFT sinc-like behaviour. I'm looking for other methods, especially estimated from the DFT of the signal.
Comment: Are the 2 frequencies the only data in the signal? If not, how far are other frequencies?
Comment: @Royi They are not the only frequencies in the signal, but assume the other frequencies are far enough to have minimal effect.
Comment: If they are far enough relative to the observation time does it mean they can be effectively filtered out?
Comment: @Royi, yes they can be filtered out, but how would that help ?
Comment: Because it means basically you're looking to identify 2 harmonic signals with very close frequencies. That I think I have few ideas for...
Comment: @Royi Yes the problem can be put like that I believe.
Answer: This answer is a consideration of the frequency resolution when using the DFT but does not answer the question specifically in terms of what is the best algorithm. (see comments by Amro).
If the two closely spaced signals are similar in magnitude (and sufficiently stronger than any other signals, i.e. high SNR), then the highest frequency resolution (which is what you are interested in) is achieved with a rectangular window. This means simply take an FFT with no windowing, and the signal bandwidth will be 1 bin wide or similarly equal to 1/T where T is the time length of your composite signal. This relationship holds regardless of what algorithm is used; the frequency resolution is related to the time length of the signal with the best resolution of 1/T. If the two closely spaced signals are not similar in magnitude, you will run into dynamic range issues as the rectangular window has the worst sidelobe levels, which can mask lower level signals. In this case we use windowing; specifically we multiply the time series by a window function prior to taking the FFT, which will significantly reduce sidelobe levels, but will have the drawback of increasing the width of the main lobe (and hence decrease frequency resolution).
See this answer for further related info: Specific frequency resolution
Comment: thank you for you answer.
the 1/T  is the resolution of DFT maximum likelihood estimator. there are other methods with better frequency resolution. like signal subspace approximation method, MUSIC, among others.

see [Karhunen, Juha T., and Jyrki Joutsensalo. "Sinusoidal frequency estimation by signal subspace approximation." IEEE Transactions on signal processing 40.12 (1992): 2961-2972.]
Comment: Yes interesting, thank you- i can picture a phasor diagram of the two tones relative to one of the tones (such as being demodulated to baseband) so that one tone is magnitude 1, angle zero and fixed with time and the other tone therefore is a phasor with it's relative magnitude on the end of that first phasor and spinning at its relative frequency. From this i can visualize how I can measure that frequency with any two consecutive samples in time by deriving the rate of rotation (if spaced less than 1/f), as long as the SNR is sufficiently high with no other signals present.


Vertex Reconstruction Conjecture For Asymmetric Graphs

Question: Is it known whether all graphs having trivial automorphism group are vertex reconstructible? And if so, what is the proof?
Answer: Consider the following passage from [1]:

As pointed out in [22], graphs which are asymmetric should be easier to reconstruct, yet symmetric graphs (even those which are at least regular), which should present a stiffer challenge, are simple to reconstruct.

From that sentence, I would draw the conclusion that the reconstructibilty of asymmetric graphs was still not known to the authors of that survey in 2006.
While it is possible that further advancements have been made in the intervening years (or that the authors of that article were simply unaware of the result), the fact that none of the usual searches (including synonyms of the term "asymmetric graph" like "rigid" or "trivial automorphism group") turns up anything conclusive on the topic is a little suspicious. Of course, the absence of evidence is not necessarily any proof of absence but in my opinion, such a result would be of such significance (a blockbuster result, one might say) that the article that proved it should be very, very easy to find.
A few more recent sources that appear to omit mention of any result regarding the reconstructibility of asymmetric graphs are [2] and [3].

Asciak, K., et al. "A survey of some open questions in reconstruction numbers." Preprint (2006).
Hartke, Stephen G., et al. "Automorphism groups of a graph and a vertex-deleted subgraph." the electronic journal of combinatorics 17.1 (2010): R134.
Lauri, Josef, and Raffaele Scapellato. Topics in graph automorphisms and reconstruction. Cambridge University Press, 2003.
Answer: By a well known theorem of Erdös, the smallest non-trivial asymmetric graphs have V(G)=6. The Reconstruction Conjecture states that all finite graphs with 3 vertices or more are vertex reconstructible. So the vertex reconstructability of nontrivial, finite asymmetric graphs is entirely contingent on this fundamental, and yet unproved, result. The question of wether asymmetric graphs are all vertex reconstructible is essentially an iteration of the Reconstruction Conjecture itself.
Comment: I'm not sure I understand the logic here. The OP is asking if a special case of the reconstruction conjecture is known to be true. That the conjecture in the general case is still unsolved does not mean that it is not solved for this special case.


NP-complete promise problems?

Question: Are there any good examples of promise problems that are NP complete?
Comment: We don't have a strict policy for list questions, but there is a
[general dislike](http://blog.stackoverflow.com/2011/01/real-questions-have-answers/).
Please note also [this](http://meta.cs.stackexchange.com/q/20) and
[this](http://meta.cs.stackexchange.com/q/145/) discussion;
you might want to improve your question as to avoid the problems
explained there.  At minimum the question should identify the criteria for what constitutes an acceptable answer, and it should be possible to produce an acceptable answer that is not too long (no more than a few paragraphs long).
Answer: There's two trivial answers:

No. For a problem to be NP-complete it must be in NP. To be in NP it must be a decision problem and promise problems aren't decision problems (they don't have to answer Yes or No on inputs outside the promise).
Yes. If you want to say informally that something is NP-complete (usually meaning "there's an obvious equivalent decision problem that is NP-complete"), then you can reformulate any decision problem as a promise problem just by taking the promise to be the set of sensible inputs. For example we can make a promise version of Dominating Set by taking the promise $L_{YES} \cup L_{NO}$ to be the set of all simple, undirected, unweighted graphs (so if you give it an input that's not a graph, it doesn't have to do anything in particular).

So there's no list of NP-complete promise problems because either none of them are (the strict answer), or you can just take any NP-complete problem and make a promise version.
Comment: @ABD. Yes, (Halting problem is decidable) $\Rightarrow$ (P = NP). We'd also have (Halting problem is decidable) $\Rightarrow$ (Moon is made of green cheese).
Comment: ( For a problem to be NP-complete it must be in NP. To be in NP it must be a decision problem) So, if we solved the halting problem, then we proved that P=NP ? If so, is there an offical paper or source that states so ?
Comment: All you have to do is to build a model of computation that can simulate a TM => a Universal TM (UTM), then by using a specific encoding scheme, you can halt any input.
Comment: @ABD, the Halting Problem isn't simply to halt on any input, it's a problem where we get the description of a Turing machine and a string and we have to decide whether the given TM halts on the given string. It's provably undecidable, so "solving" it would be a contradiction, and and thus you could derive any result from it (including _both_ P = NP and P != NP).

NP-complete promise problems?


What are the Food sources for an underground city?

Question: Let's assume a city exists underground, either in natural caves or synthetic tunnels.
Are there any food sources underground, and what kind of population can they support?
Answer: The main natural sources of food energy for underground life on Earth are chemical:

Biological material moving down from the surface.
Reactive chemicals, such as hydrogen sulphide gas, moving up from deeper underground. The most studied example of this on Earth is hydrothermal vents, which share a lack of energy input from sunlight with cave systems.
Less-reactive chemical weathering that can be catalysed by creatures that possess the right kinds of enzymes. These are specialised bacteria, and live life in the slow lane. However, they can literally digest rock (or at least some kinds of rock).

Chemo-synthetic bacteria can be the base of a food web supporting more complex creatures. Estimates of the biological mass vary, but could be very large due to the sheer volume of rock. However, there is nowhere near as much free energy around to support life in a given volume, as there is on the surface due to sunlight.
An underground city with enough technology has the option of generating energy to support the base of its food production. On Earth the obvious choice would be artificial lighting to grow plants. However, using e.g. nuclear fuel to generate electricity or heat, and store that energy in feedstock chemicals should work equally well.
Comment: @FlorianPellet Fungus needs some sort of biomass to consume.  Plants, animals, or other fungus.
Comment: What about fungus? Isn't that what many ants eat, living underground?
Comment: @Sheraff and fungi just produce biomatter out of thin air? Nope. Also, there's only  a few ant species that eat/grow funi. and thats Leafcutter ants. Which also spoils how these fungi live: the ants cut up leaves for the fungi to grow  on.
Comment: Thanks, I was going to write up my own answer, but this covered everything I was thinking of.
Comment: Can you cite any sources? This is a hard-science question, and we like seeing sources in our answers.
Comment: There's also geothermal energy from deep underground. Some greenhouses are now heated this way in Holland in winter. You'd need a bit more energy without any sunlight, in order to create enough light for the plants to grow, and you'd needs good ventilation from surface air; but it may work. And you can keep animals that feed on your plants, if you have enough energy and air.
Answer: The main problem in this scenario is the input of energy. Life on earth is fueled from the surface by sunlight. This is then turned into energy by plants, algae, and suchlike and then the entire food chain is built up from that.
Some life can live near the surface of cave networks based on the surface food web (for example it is common for animals to live in caves then emerge to forage or hunt). Cave-dwelling bats would be a classic example of this.
To have a sustained ecosystem underground you need a source of energy. Most novels set in these sort of environments (for example the Forgotten Realm's Underdark) that source of energy is magic, which fuels the growth of fungi, and then the food web grows out from that.
In a science-based universe though that is not an option so you are left with very few options:

Geothermal
Mineral Consumption
Some as-yet-unknown energy source

Reviewing these in reverse order:
Unknown Energy
Since the concept for option 3 would be a core departure from known reality there is no use speculating here. The nature of the energy source would need to be designed for the needs of the narrative world being developed and would likely be a core part of that world.
Mineral Consumption
Some bacteria are capable of living underground and consuming materials from the rock around them. This is a slow and low-energy process though, you could not sustain a complex ecosystem or large animals this way.
Geothermal
There is a well known case of complex ecosystems on earth that are not dependent upon Sunlight. That is Hydrothermal Vents in the deep oceans.
http://www.marine-conservation.org.uk/thermalventlife.html

http://en.wikipedia.org/wiki/Hydrothermal_vent
These vents support ecosystem with bacteria at the start of the food chain, and then a procession of larger creatures all feeding off the bacteria and each other. In theory the same process could be supported underground, either in flooded caves (with non-aquatic animals then feeding off the creatures in the caves) or possibly even in dry caves.
The main hazards though would be the level of volcanic activity required to form the vents which would make caves unstable and prone to collapse. Additionally you would need some form of erosion either by lava, by water, or by some other as yet unknown action to form a cave network.
Comment: How about if you just burned gas or coal or use uranium, in order to create enough light and heat to feed plants in large caverns?


How to mark the output and remove zeros?

Question: This is a program to simulate rolling a dice 20 times and marking the most consecutive number, a dice doesn't have 0 which I don't know how to remove, I'm new to java
package diceroll;

import java.util.Random;

public class Roll {

//public static void main(String[] args) {

private static Random generator = new Random();

public static int[] randomIntArray(int length, int n)
{
    int [] ems = new int [length];
    for (int i = 0; i <ems.length; i++)
        ems[i] = generator.nextInt(n);

return ems;
}
}

package diceroll;

import java.util.Arrays;

public class Dice {

public static void main(String[] args) {

    int[] ems = Roll.randomIntArray(20,7);
    System.out.println(Arrays.toString(ems));
}
}

When it prints it prints something like this:
[4, 2, 2, 5, 2, 0, 5, 0, 5, 5, 1, 3, 3, 3, 1, 4, 3, 1, 4, 4]
How can I make the code not generate zeros and mark the most consecutive numbers like this:
[4, 2, 2, 5, 2, 0, 5, 0, 5, 5, 1, (3, 3, 3), 1, 4, 3, 1, 4, 4]
Answer:
How can I make the code not generate zeros ...

Since Random#nextInt(n) returns a number between 0 (inclusive) and n (exclusive) you might just add 1 to the result to change that to a number between 1 and n (both inclusive). If you want n to be excluded, pass n-1 to nextInt(...).

...  mark the most consecutive numbers ...

You'd have to calculate that yourself and provide your own printing routine.
To calculate the longest row of equal numbers, just iterate over the array once and calculate the length of each sequence (length = 1 if the numbers are different and length += 1 if they are equal). Whenever you discover a new sequence or hit the end of the array, check if the last sequence was longer than the longest before and if so, update the starting index of that sequence and the new max length.
When iterating over the array for printing you then check whether you enter the sequence you calculated before and if so, print (. Then you check whether you leave the sequence again or hit the end and print ).
Answer: To avoid 0 you must add 1 to nextInt output (it starts from 0).
You can mark the most consecutive numbers during array population.
Something like
int length=1;
int defLength=0;
int startIdx=0;
int defStartIdx=0;
int endIdx=0;
int defEndIdx=0;
// Needed in order not to override start index
boolean found = false;
if(efs[i] == efs[i-1]) {
    ++length;
    if(!found) {
        startIdx=i-1;
        found = true;
    }
 } else {
     if(found) {
            endIdx=i-1;
            found=false;
    }
    if(defLength < length) {
           defEndIdx = endIdx;
           defStartIdx = startIdx;
           found = false;
    }
}

Then you need a print method to put your parenthesis before printing efs[defStartIdx] and before efs[defEndIdx]
Comment: I'd put this in your randomIntArray method.
Variable declaration outside for loop, remaining code within the loop.


I want to make two arduino to communicate over different wifi. Is that possible?

Question: I want to make any 2 Arduino module from different places to communicate over wifi. I really need to know if it possible? If yes, advice me more about it. I want send data from sensor module from one Arduino to another and vice versa. That's the basic idea. Do I need a third party services such as cloud services to make it happen? Or simply can send ovee wifi with the help of Ip adress. Sorry, I have less knowledge on this. Help me out. Thank you in advance.
Answer: If they are on the same (wifi) network; then yes.
If you are on a different network, it would be more difficult. You would have to setup port forwarding on your router. Then you would have to somehow know the public IP address of the other router. These addresses can change from time to time with certain ISPs. I wouldn't advice doing this.
Instead I'd go with an third party service. For example Adafruits offers an MQTT server. I'd probably use this even if they are on the same network.


Could Subset Sum Problem Be Solved In linear Time Using Logarithmic Space?

Question: Is there any known lower bound on the complexity of subset sum problem? For example, could it be solved in linear time using logarithmic space?
Answer: No such bound is known; for all we know, it may be possible to solve it in linear time. In fact, for all we know, there might be an algorithm for it that uses $O(\log(n))$ space on its work tape.
We know one thing: There is not an algorithm which uses both linear time and logarithmic space. That is, there is a time-space lower bound! A Subset Sum instance of size $n$ can be reduced to a 3SAT instance of size $O(n^2)$ (perhaps there is a better reduction), and for 3SAT, we know that, if $t(t+s)<2$, then
$$3SAT \not\in TiSp\left(n^{t},n^{s}\right) $$
With $TiSp(t(n),s(n))$ the class of problems solvable in $O(t(n))$ time and $O(s(n))$ space. This is not the strictest bound, see Computational Complexity: A Modern Approach for more details.
But that still leaves open whether there is an algorithm which uses $O(n)$ time and $O(n)$ space. (Of course, the non-deterministic time hierarchy theorem tells us that for every $t(n)\in poly(n)$, there is a problem $L\in NP$ which provably requires $\Omega(t(n))$ time, the question is whether the subset sum problem is one of them.)
So yeah, that bound is not great. It's not the bound we deserve, but it is the bound we have right now.
Comment: you still didn't fix the answer. Could you please do it?
Comment: Would you like to fix the errors you've mentioned?
Comment: First, the reduction should be from 3SAT, not to 3SAT. Second, if the reduction costs $O(n^2)$ then there's no guarantee that subset sum problem needs less than $O(n^2)$ time, and thus, this time-space lower bound (which is less than $O(n^2)$) does not hold in my opinion. Am I wrong?
Comment: @DudiFrid. You're absolutely right. The lower-bound still holds; the theorem is $NTime(n)\not\subseteq TiSp(n^t,n^s)$, but the proof as it stands now has elementary errors. I'll fix them, thanks!


What do you call works in a flat after it has been built?

Question: What do you call works in a flat after it has been built, that include making walls between the rooms, floor covers (parquetry, laminate, linoleum), ceiling, electrical wiring, sewerage, installing sanitary appliances (w.c. pan, washbowl, bath tub, shower cabin) and finishing (plastering, surfacing, wallpapers etc)?
Comment: Are you asking about the work that is done after the "shell" of the building is built, but before the first occupants move in?  Or are you asking about changes that are made after the first occupants have moved in?  Also, are you asking about improvements that are made for the benefit of any (non-particular) user, or about improvements that are made for the benefit of a particular tenant (and their users and guests)?
Comment: @Jasper ...first
Answer: In the UK they are referred to as the 'first fix' and 'second fix'.
The first fix is everything that must be done before the walls are plastered, such as wiring, main plumbing, internal walls, ceiling finish & flooring, but nothing 'above the surface'.
The second fix is sanitary fittings, bath, WC etc & electrical sockets, kitchen units & worktops etc., doors.
There's also increasingly commonly, a third fix, for more intricate installations - electronics & dust-sensitive equipment.
See http://en.wikipedia.org/wiki/First_fix_and_second_fix which has some AmE terms too; but I'd prefer someone more familiar with those to fill in the details.
Comment: Are those terms commonly used outside the trade? I ask because I've never heard them before.
Comment: They're used such programs as Grand Designs etc., so I guess they're permeating outward into public perception
Comment: In the US, I think even people outside the trades would understand (and possibly even use) the term "finishing" to refer to what is called "second fix" in the UK.
Answer: In the US, after the foundation, framing, roof, sub-flooring, stairs, and outer walls are built, the work that comes next (electrical wiring, plumbing, interior walls and ceilings, floors, interior carpentry) is given various names.
plumbing rough-in (waste pipes/vents) but not the sinks, toilets, etc
electrical rough-in (running the wires from the breaker box, through the walls, to the outlets
drywall or plastering
flooring
finish carpentry


Script with path in Filemaker Pro 12

Question: I'm using OS X 10.6 & Filemaker Pro 12; I'd like to have a script in FM to automatically open a .pdf file from a container field using Preview (dumping the file on the desktop) but it has to be using a variable path for whomever is using this particular hosted file in our local (or remote) office network
Answer: I see that this question is a little old, but for anyone who comes across it now looking for help...
It sounds like what you need is the "Get ( DesktopPath )" function, as part of a Set Variable script step.  It would be something like this (in pseudocode):
<code>Set Variable $filepath ( Get(DesktopPath) & "filename.pdf")
Export from field ( FieldWithPDF, No Dialog) {{NB: check the box that says "Specify output file" and set it to "$filepath"}}
</code>
Also, be aware that if you're in a mixed environment (Windows & Mac), you may need a slightly more complicated Set Variable statement to accommodate for different path notations (see http://www.filemaker.com/11help/html/create_db.8.32.html).
Comment: Welcome to SuperUser! We have no rules against answering old questions here. All knowledge is worth having.

Script with path in Filemaker Pro 12


Insulating basement that's already framed with electrical run

Question: First, let me own my novice DIY status and say I screwed up. I bought a new house last year in the Indianapolis area and immediately went to work finishing the basement. The builder attached batts of insulation to the top half of the poured concrete walls to just below grade, but that's all. I framed the walls just off those batts -- so several inches from the foundation. Didn't consider any other insulation as I assumed like a novice that I'd just insulate the stud cavities after everything was done. It's only recently I've become aware that the preferred option is rigid foam attached to the concrete walls for moisture control. I've now got a 2000 sf basement fully framed with electrical run and I'm wondering what my best and most cost-effective course of action is for insulation. Thanks for any advice!
Comment: @isherwood it's a basement in central Indiana. It's guaranteed to have moisture problems. You drill a well around here by hamming a piece of pipe a foot or two into the ground and putting a pump handle on top. (close enough) Reference: 30 year resident. OP & I are darn near neighbors.
Comment: Is there a moisture concern? The foam approach certainly isn't a requirement if you have generally dry soil.
Comment: Thanks for the quick replies, everyone!  To answer some questions: As FreeMan mentioned, there's definitely outside moisture issues.  I've got no specific mitigation system installed.  Just a standard sump pump that does run a good amount after rain.  I've never seen water inside the basement, but it's only been a year.  My dehumidifier keeps the whole space under 50%, though.  Here's a link to photos showing two different walls.  They all pretty much look the same with fiberglass on the top half and also shoved into the rim joists I just noticed.  https://photos.app.goo.gl/1Kq5uGx6XoicXFBJ9
Comment: One additional piece of info I found out is that my builder used a waterproofing membrane outside called Tuff-N-Dri Hydra-Guard or something.  I don't believe they used the insulating board on top of that, but I'm looking into it.  Would a membrane like that make any difference in what I do inside the walls?
Comment: A few pics would help. I have ideas about tipping walls out of the way to get foam in, but it's hard to say with only general information.
Comment: FreeMan, we don't know whether there's an exterior mitigation system installed or anything else. I'd rather hear it from the horse's mouth.
Answer: Just wanted to come back and say my plan is now to remove the fiberglass insulation from the top half of the wall, cover the walls with foam foam board insulation (EPS) by threading sheets through the studs and at the large openings for my egress windows, then reuse the fiberglass in the stud bays (along with more I'll need to purchase).  This approach has been recommended to me on several forums in order to minimize condensation on the cold concrete walls when warmer air from inside hits it -- especially in winter.  For about $1000, it seems the smart thing to do, albeit a bit of a pain to get all that foam delivered and installed.  But this is a large basement that will have a lot of living space, so it's obviously best to do it right.  Thanks for replies all!  Any further input is certainly welcome!


The Hockey Puck and Combat Carl in Toy Story

Question: Was the Hockey Puck in the first Toy Story movie only put in as a gag or only for Mr. Potato Head to say "What are you looking at, you hockey puck?" as we don't see it anymore after that. Also, why is Combat Carl in the first Toy Story movie different from the Combat Carl seen in Toy Story of Terror?
Comment: should this be divided into 2 separate questions?
Comment: Here is the scene in the question, for reference: https://www.youtube.com/watch?v=_WiwOojDTrs
Comment: @miltonaut yes...probably :)
Answer: Regarding the hockey puck reference: definitely.
In Toy Story, Mr. Potato Head is voiced by famous insult comedian Don "Mr. Warmth" Rickles. In the early days of his career, "hockey puck" was one of Rickles' signature insults, typically used to lambast ill-behaved audience members.

Wikipedia


Is honey considered vegan?

Question: I was thinking of following a vegan diet for health reasons. I tried it for a week during a "cleanse" and it wasn't so bad, even though I love steak and eggs. I was just curious though if honey is considered vegan or not. It's an animal (bee) byproduct, right? The only difference maybe is that it's something bee's make naturally, although if we farm them for the honey it's not exactly humane (see A Bee Movie).
Comment: If you're doing it for health reasons, I don't think this is the important question. Yes, it's an animal product - but does it share the nutritional characteristics of other animal products that you're trying to avoid? Corn syrup is vegan, but is it really going to be better for your health than honey?
Comment: To be honest I do not understand the problem. You do not seem to be concerned with the fact of eating animal-derived products, so if your only reason to follow a vegan diet is to eat healthy food, well then honey is quite an healthy food if eaten correctly, pretty much as any other food. *Sola dosis facit venenum* :)
Comment: If there was ever a question tempting to just put a complete answer of "No." .... :)
Comment: Well I don't actually tend to eat that much sugar or sugar substitutes anyway. The question was mainly just a matter of curiosity. Regardless, I think having some kind of strict rule helps me to avoid temptation, so the theory is if I can just pretend to be vegan I'll generally eat better. I grew up on microwave dinners and cheese-filled hot dogs so I'm trying to retrain my diet and I'm trying to become better educated in the nutrition department.
Answer: Honey is not vegan.  In short, the core tenet of veganism is living without exploiting anything in the animal kingdom, and most (if not all) vegans consider taking honey from bees a form of exploitation.
Comment: A direct corollary would be milk. Also, honey can sometimes contain insect parts apparently.
Comment: All vegetable mater has animals or animal parts in it. You try growing something without bugs getting in to it!
Comment: I've met one person who was otherwise vegan who had an exemption for honey. Her reasoning was that bee keepers set up environments that allow the bees to create far more honey than would be 'naturally' possible, with the same amount of work. As a result they produce more than they actually need, so taking the excess is ok and not exploitation but more of a reciprocal relationship (bees obviously cannot be imprisoned - if the conditions are not to their liking they will leave). YMMV, obviously.
Comment: @TFD: There are some ultra-orthodox Jewish and Muslim communities who are actually refusing to eat or serve broccoli, cauliflower, herbs, etc., because they might have tiny insects. Wouldn't be that much of a stretch for the truly obsessive vegans to start doing the same... once they cotton on to the trend.
Comment: +1: If you take anything (other than excrement...Probably) from anything that has eyes or a face, it's not vegan.
Comment: "Most (if not all) vegans consider taking honey from bees a form of exploitation."  I'm calling citation needed.
Comment: @tudor I know this is stackexchange and pedantry is to be expected, but please keep in mind that the way the Vegan Society uses the term is not necessarily the same as the rest of the world; for example the OED says "A person who abstains from all food of animal origin and avoids the use of animal products in other forms." and other dictionaries simply say things like "a vegetarian who omits all animal products from the diet." You're fighting a battle that's already lost.
Comment: @Jefromi This may be a cooking site, but definitions are important.  I've experienced first hand the medical outcomes of people's mistakes in misusing a defined term.
Comment: @tudor That's not what's going on here. Please go to [meta] if you want to discuss further.
Comment: Also, core tenet according to whom?  I know people who are vegan for environmental purposes and are not (very) concerned with whether animals are exploited.
Comment: @djechlin Unlike "vegetarian", the terms "vegan", "veganism", and the "vegan diet" are all defined terms.  The Vegan Society was created at the same time as the term to protect its meaning.  See http://www.vegansociety.com/
Comment: @Jefromi. If you look at the history of the term "vegan" you'll see that it was created to avoid confusion that had occurred with the misuse of the term "vegetarian". It may be pedantic but it's an important distinction to make as the end result is quite different.  I disagree that the battle is already lost.  I have experienced many people's misuse of the word, but that doesn't mean that the definition has changed.
Comment: @tudor I'm just telling you what people here (and a couple dictionaries) are understanding it to mean; we're a cooking site, and we don't really want every question that mentions veganism to turn into a debate about its meaning. Take it to http://english.stackexchange.com if you want to ask what it actually means or debate about whether the definition has changed.
Comment: @Satanicpuppy: [Earthworms aren't vegan either!](http://www.reddit.com/r/vegan/comments/g5gyu/are_garden_worms_vegan/) ;-)
Comment: @TFD: You're right.  We should all just become [freegan](http://en.wikipedia.org/wiki/Freeganism) [fruitarians](http://en.wikipedia.org/wiki/Fruitarianism)!  ;-)
Comment: Honey is food for bees, and bee babies they don't make it for fun... if I was the sort of person who wanted to be a vegan I wouldn't eat it.
Answer: I'm vegan, and don't eat honey,  but I think it very much depends on why you went vegan. If it's for health then I don't think it makes a difference. If you want to get into a moral argument you can make the case that it's closer to using wool than using milk... (I don't make the argument, but I respect that people can)  but the choice is yours - it was a pretty easy choice for me as I didn't like honey to start with... :)
Comment: Um... I was being quite careful *not* to make the argument, I was mentioning it in the context that I've been in the presence of people who used the same reasoning. :)
Comment: As for environmental, economic, and animal cruelty reasons, wool and milk and honey are equivalent. They all rely on support of "exploitive" animal economies. I don't want to come across as argumentative as honey can make for flames with some vegans, but I fail to see your argument contrasting milk and wool, could you expand on that in your answer?
Answer: This is purely a semantics question.  It depends on how you define "vegan."  If you define vegan to mean something like "contains no animal products," then honey is not vegan. Can you be vegan if you eat honey, or can honey be part of a vegan diet?  Those are more slippery questions.  I know many people who identify as vegan and practice veganism for various combinations of health, environmental and ethical reasons, who choose to consume honey.
In my experience, there isn't really a such thing as being a vegan for health reasons, because I do not know of any vegan diets whose purpose is to optimize nutrition.  For instance, the American Heart Association recommends eating fish (particularly fatty fish) at least two times (two servings) a week. I have never met someone who identifies as vegan primarily for health reasons.  The only people I know who never "cheat" on their vegan diets are vegan strongly for ethical reasons. However, it may be a healthy step for you to take in your diet because exposing yourself to the vegan community may lead to you eating a lot more food that is healthy for you and a lot less food that is unhealthy for you.  Would the vegan community accept you if you still consumed honey? Depends on the people, but in my experience with vegan communities as someone who still consumes fish, probably.
Could you identify as vegan if you still consumed honey?  Sure, that's up to you.  Will other people agree that you are vegan or accept you as a vegan?  In my experience, non-vegans will consistently think of a honey-inclusive diet as vegan, partly because they, like you up to before you asked this question, haven't given it much thought.  Strict vegans who don't eat honey might not, but I don't see any reason this should be important to you.
Answer: Semantic question, I subscribe, but I'd like to add a consideration. Let's think to the reason why people became vegan.

Cultural reasons? Surely this is not the case of western vegan movement (on the contrary, not rarely vegans are despised for they choice)
Religion reasons? Surely some eastern religion push to veganism, but in western context religion plays no role in vegan choice. Personally, I'm atheist, like the few vegan I know.
Health reasons? Man is omnivore, why don't eat animal food should be healthier? (normally vegan diet is not dangerous, but evidently this is not a reason to became vegan)
Love for animals? I don't find this plays an important role in vegan movement. Personally, I hate that stupid and smelly being (but not so much to improve torture on them with my food choice)

In most of cases western people became vegan simply because they don't like causing terrible pains (castrations, spending life in a cage big as your body, violent killing, etc., look for example to mercyforanimals investigations and sites) for very frivolous reasons (meat taste, urban legend that veganism is normally dangerous for health, etc.). Maybe there are more important problems in the world, but none with a so simply and not demanding solution. Most of western vegan did this choice after consideration that only for very important reason (medical research, for example) we could eventually cause pain to a living being (I said "pain", so I'm speaking about living being with a complex nervous system, not about vegetables or micro-organisms). So veganism has many roots (economic, ecological, etc.) but fight against useless pain is surely the first one. Now, having said all that... what about honey? The question is: "bees feel pain?", or more precisely: "honey industry cause pain?". I'm vegan and I eat honey, because I suppose the answer is "not" (but I'd like to know biology answer).
Comment: However, for culinary purposes, above recommendation to not consider it vegan is proper. The fact that products with honey or beeswax in them do not usually get labelled vegan by manufacturers that do label their vegan/vegetarian products should paint a clear picture of the accepted norms around that term.
Comment: Of course I agree, product labeled vegan in market doesn't have honey. Anyway I wouldn't use this fact as unquestionable criterion about the meaning of the word vegan. Food producers logically take a decision prudent, that doesn't give any trouble and match all potential buyer. Anyway I suspect that many vegan eat honey. I won't quarrel about this question, simply I think that the meaning of this word, as it is used in society, is a bit ambiguous.
Comment: Most groups advocating veganism will also discourage honey.
Answer: For ethical vegans (i.e. for whom ethical reasons alone are enough to follow a vegan lifestyle) the question of whether honey is vegan largely a question of whether bugs feel pain, and if they do, how much of suffering does a bee life contain.
Since insect sentience is an open question, and knowing the farming industry's usual horrific treatment even of mammals and birds, honey is seldom considered vegan.
Comment: My visiting vegan ate our honey, because he knew for a fact that the bees had set up home in the (stored, empty) hives, and that we had moved the hives out of the shed for them and given them wax frames to store their honey in, saving them all the energy of making that wax, in exchange for which we took half the honey. (I know, they didn't fully consent to the deal, just moved into the hives, but hey, I didn't consent to their moving in.) He considered them volunteers and so ate our honey, but not honey from stores. Your vegans may vary. PS we never hurt our bees and we protected them too.
Comment: Typical bee farmers provide wax frames, insulate the hive to reduce winter kill, medicate to kill mites, and provide sugar water if the fraction of the honey left behind is not enough to sustain the hive. Unlike say dairy farmers (who choose when to breed cows and with what bull, then take away the calves after they're born) apiarists don't interfere in the reproduction process, except that a weak nonlaying queen is typically killed and replaced. My sister does that and has only one hive not kept for money but for the sake of her city ecosystem.
Comment: @KateGregory unfortunately, a typical bee farmer, for whom honey is a primary source of income, seems highly unlikely to be that benevolent toward the honey-producing machines. Personally, I deem irresponsible bringing into existence any sentient being.
Comment: @KateGregory still winter kills, accidents, interspecies conflicts, and just a general expectation from a Darwinian life-form to be vulnerable and conditioned to suffering, make me prefer to not having bees in the first place. Alas, vacant places in nature never stay so for long: freed resources the bees currently consume would allow for more other bugs. Plus, agriculture still largely depends on biological polynators. Thanks for your story, btw.

Is honey considered vegan?


Which recommender system: Content based or Collaborative filtering?

Question: I want to build a recommender system for a coupons website which should do the following:
Given the past purchase behaviour of a user, recommend coupons which the user is likely to buy.
The data does not have any ratings for coupons by the user. It tells if a user bought a certain coupon or not and what is the gender and location of the user who bought these coupons. Between content-based and collborative-filtering what would be the best recommender system to choose from in this scenario. Personally, I think that content based recommender system fits the requirement because I want to look only at user's own historical behaviour. What would you guys advice? Thanks.
Answer: You are right. Content-Based Recommender System is the best approach to tackle such problems using historic information about the users.
Answer: I think it will strongly depend on the details of the content you have for the coupons, but you can always train an hybrid model with different options of selection for the final recommendation, like weighting the results or selecting the top one of each model. The most important thing is that you build a reliable test set and can compare performances between models.
Comment: How can I build or use a hybrid model


J 1 visa issue date= start date?

Question: My issue date for my J-1 visa is 20th of may 2018, the start date on my Ds 2019 form (which is also stated in the visa in my passport) is 30th august 2018. Is it ok for me to enter the US on the 22nd of august? It is within the 30 day period but I am confused since it says 30th of august in the visa
Comment: Please edit to clarify what your visa says? Normally a US visa only shows the "issue date" and "expiration date". If the issue date shows 20 May 2018, where does it say 30th of august in the visa?
Comment: under annotation it says 30th august - 20 december which is the dates in the DS 2019 form
Answer: It's not normal for a J-1 visa to show the DS-2019 program dates, particularly because normally the DS-2019 program dates can be changed and you can still use the same visa. Try a Google image search for "J-1 visa" and you will see that most mention only issue date and expiration date, as well as the annotation regarding whether you're subject to the 212(e) two year home residence requirement.
Normally, when the J-1 visa doesn't show the program dates, you can enter the US up to 30 days before the DS-2019 program start date.  This is probably true in your case as well, but you should check with the consulate that issued the visa to be sure. Be sure to keep your program sponsor (DS-2019 issuer) informed as well.
Comment: for anyone finding this and has the same question I am happy to say that there was no problem for me to get in to the US
Comment: @user15564 you can add that as an answer; it's more likely to survive, and it's searchable, which comments are not.
Comment: thanks for the response, I googled and saw some visas that had the DS 2019 number and program number like I do, and some that hade the dates as well

J 1 visa issue date= start date?


Is it okay to link to live examples?

Question: If a have a question concerning interaction design, and I want to illustrate with a live example - e.g. a quick prototype hosted on http://jsfiddle.net, would that be okay?
Comment: The live example could also perhaps be a screencast video demonstrating the interaction?
Answer: Live examples are extremely helpful, it immediately presents the context of your application or question and may give details you did not or could not give in the wording of your question. At the very least give a screenshot if possible.
Examples using JSfiddle are great, such as this question which involved a specific design. Giving feedback on that case would have been impossible without at least a screenshot. An important reason to give screenshots or JSfiddles is so we can reply with altered mock ups to "show our work", and if one of us can't edit Javascript or figure out JS at the very least we can alter a screenshot of the app in question.
Screencasts are similarly helpful as you could point out the exact problem, though I suspect they could fall prey to the "tl;dr" problem. If you have a specific behavior in an application you want to ask about and JSFiddle can't handle a mockup of your app it's a good visual way to present the issue.
Comment: Thanks! tl;dr = too long; didn't read? The reason for asking is really related to persistence. The author has to be careful to make sure the example stays live for future reference.
Comment: I'm not sure what the philosophy of Stack Exchange says about persistence, but I suppose they favor text over images, because search engines only indexes the first one. Using imgshack as (non-persistent) Image Hosting also sends the signal: We don't want to make too much fuss about it, if it's not popular enough, it will die, so what? The intresting question is here, whether screenshots play an even more important role in UX than in SE?
Comment: @giraff our philosophy seems to support persistence, but mostly for text. We use Imgur instead of hotlinking images and I at least assume those images will persist as long as Imgur does.
Comment: The staying live problem can be resolved by giving enough information in the question for the answers to be understandable, but the live link assists in getting to a correct answer.
Comment: I understand the usability of live examples but oftentimes live example links go dead quickly. On Stackoverflow, such links may get your question or answer closed for that very reason. [This whole quesiton](https://ux.stackexchange.com/questions/111914/html-select-element-dropdown-keyboard-expected-functionality) becomes one big unknown without the links to YouTube. Has anything changed regarding this over the last six years?

Is it okay to link to live examples?


Specific line bundle over complex manifold implies Kähler?

Question: Let $L$ be a holomorphic line bundle on complex manifold $X$, such that it admits a hermitian structure whose Chern connection has positive curvature. Is $X$ then Kähler?
Comment: Yes, by definition of Kahler manifold. Moreover by Kodaira embedding theorem such complex manifold is projective
Comment: My definition of Kahler does not refer to these line bundles.  Sorry if I am overseeing something.
Comment: Matt: Kahler usually means that you have a metric $h_{ij}$ such that
the associated form $\omega = const. \sum h_{ij}dz_i\wedge d\bar z_j$
is closed. You can work backwards to see that any closed positive $(1,1)$-form $\omega$ is a Kahler form. In your case, let $\omega$ be the Chern form of your positive line bundle $L$. Does that make it clearer?
Answer: As Dima said, it is much more: in fact it is projective. But let me give you some more insights on this kind of questions.
I shall give you the definition of four different classes of compact complex manifolds.

Projective manifold: closed submanifold of some complex projective space.
Moishezon manifold: compact complex manifold such that the field of meromorphic functions on it has transcendence degree equal to its complex dimension.
(Compact) Kähler manifold: compact complex manifold carrying a Kähler form, that is a closed positive smooth (1,1)-form.
Manifold in the Fujiki class ($\mathcal C$): compact complex manifold bimeromorphic to a compact Kähler manifold.

A Moishezon manifold can be shown to be bimeromorphic to a projective manifold, so that -in some sense- Moishezon manifolds are with respect to projective manifolds as manifolds in the Fujiki class ($\mathcal C$) are with respect to Kähler manifolds.
It turns out, that one can characterize these four classes in terms of cohomological properties (these characterizations reflect again this relation between projective-Moishezon and Kähler-Fujiki). Here is the characterization for you:

A compact complex manifold is projective if and only if it carries a (1,1) rational cohomology class which can be represented by a positive (1,1)-form (or equivalently if it carries a positive hermitian line bundle). This is the content of Kodaira's embedding theorem.
A compact complex manifold is Kähler if and only if it carries a (1,1) real cohomology class which can be represented by a positive (1,1)-form. This is almost the definition.
A compact complex manifold is Moishezon if and only if it carries a (1,1) rational cohomology class which can be represented by a (1,1) Kähler current, that is a (1,1)-closed positive current which is bounded from below by a (non necessarily closed) smooth positive (1,1)-form (or equivalently if it carries a big line bundle).
A compact complex manifold is in the Fujiki class ($\mathcal C$) if and only if it carries a (1,1) real cohomology class which can be represented by a (1,1) Kähler current. This is the content of a theorem by Demailly-Paun.
Comment: I find myself objecting more and more to the definition of a Kahler manifold as one carrying a hermitian metric with closed Kahler form. It's a very nice characterization for calculations, but it tells nothing about where this property comes from or what it means. I much prefer saying a Kahler metric is one whose Chern connection is torsion free, i.e. the Chern connection is the Levi-Civita connection of the real part of the hermitian metric, because the question of when that happens at least arises fairly naturally.
Comment: ... Now given a hermitian metric $h$ with Kahler form $\omega$, we  write $\tau$ for its torsion tensor. Then we have $h \circ \tau = \partial \omega$, where composition with $h$ denotes raising of indices. This makes clear the equivalence between "Chern connection torsion free" and $d \omega = 0$.
Comment: @Gunnar: Do you have a reference which takes the approach you mention (in particular, shows $h\circ\tau = \partial\omega$)?
Comment: The question did not ask about compact manifolds. You need compactness   as well as a positive line bundle to ensure projectivity.
Comment: Ben, incidentally I know that a projective manifold has to be compact (closed in a compact is compact, right?)... This question did not state either that the manifold had to be non-compact. I just treated one aspect of the question: the compact case.


Reporting Engines used with ArcGIS Server

Question: I'm curious what others are using to build the more elaborate reports out of ArcGIS Web API apps?  By elaborate I mean ones that include lots of dynamic charts and tables, multiple maps/data frames with legends on a single page, etc.  Seems like historically Crystal Reports and SQL Reporting Services are mentioned.  What about ReportLab?  Or with the recent improvements in ArcPy in 10.1 is it possibly better to roll something out independent of a reporting engine?
Answer: I use ReportLab with ArcGIS Geoprocessing Services. It has a syntax that takes some getting used to but works great at 10.0 and 10.1!  Of your desired functions the only one I am not currently doing is charts - because I have not yet had a requirement to investigate it.
Comment: Great answer. I am also going to integrate ReportLab with ArcGIS.Thanks for the answer : )


Magento Product Images in Cache

Question: When I check /pub/media/catalog/product/cache/, there are many folders. Each folder contains the same images with different size. So I'm not sure about why there are same images with different size.
Answer: refer to this Images sizes in magento 2
You have a different size depending on the number of format defined for this image in your template...

Magento Product Images in Cache


How can variable speed be used on a random-orbit sander?

Question: I see some models of random-orbit sanders have a variable speed control. Under what circumstances would I need variable speed while sanding? It's not clear to me what benefit it offers.
Comment: I have several ROS sanders and never use other than on high speed lower speed appears to leave more swirl marks. Use finer paper on finer work. High speed and fine paper leaves no visible sanding marks. Be careful on edges not to round them, unless you want them rounded over. That is my story and I'm sticking to it.
Answer: When you want to sand more aggressively, you use a faster speed. When you want to sand more gently (to take greater care not to sand through veneer or finish for example) you would drop to a lower speed1.
Just to note, final sanding of wooden surfaces should normally be done by hand to help reduce the chance of 'pigtails' or sanding swirls2 and to ensure the best finishing result. This is commonly done using the same grit as the final ROS sanding (e.g. 180-240) with the abrasive backed by a sanding block and following the grain. Alternatively you could do a final scraping, but if you're scraping you might skip the ROS entirely!3

1 Coarser paper and finer paper would normally be used in each case as well of course, but using the same grit there's quite a difference in aggressiveness between a high speed and a lower speed.
2 The random orbit and good technique (do not press hard, move the sander slowly) already reduce this tendency significantly over normal rotary sanders, but it's still quite easy to leave occasional swirls or some indication of cross-grain sanding.
3 See previous Answer for why scraping is better than sanding.
Comment: It's good to know that "Variable speed!!!11!!" isn't _just_ marketing hype.
Answer: The faster it spins, the more material it will remove. When sanding solid wood, I go full speed. But, if I am sanding a coat of poly or a plywood veneer, I go at it with a much slower speed as to not chew through the top layer of material.


Are LED bulbs bad for my inverters?

Question: Are LED bulbs bad for my Power Inverter?
Comment: Hello, and welcome to Stack Exchange. It isn't at all clear what you're asking here, and some more information would help (e.g. what are your inverters used for? make and model?)
Comment: @DanielGriscom I believe the OP is asking about a power inverters in general at his home or work.
Answer: No, LED bulbs are not bad for an inverter. Although LED are Semiconductor devices and work on DC only, the circuitry inside the bulb drives the LED from AC voltage.
The AC voltage coming out of the inverter will eventually be converted to a DC voltage to drive the LED. This will be done internal to the LED bulb unit.
Overall, LED bulbs will benefit inverter by using less current rather than harming it.

Are LED bulbs bad for my inverters?