Publish a Google Drive SDK app to Trusted Testers

Question: I have followed the steps described in https://developers.google.com/drive/listing and have created a private Chrome Web Store listing for my app.
The owner of the Chrome Web Store listing (i.e., myself) can see the application and was able to install it in his Google Drive.
However the others trusted testers cannot see the app (it does not appear in search results in the Chrome Web Store, and it does not appear in the "Connect more apps" in their Google Drive).
How can I make the private listing visible to them ?
Answer: ok I found the issue: I was trying another "trusted tester" account in the same Chrome browser as my main account. For some reason, it doesn't work (I can't install the Chrome Web Store application "twice" in the same Chrome).
So I created a new Chrome user for my other tester account, so as to have a clean Chrome environment, and I was able to install the app from the Chrome Web Store again in this new environment.


what uses up less battery, reading an EPUB or reading a PDF?

Question: If you get a PDF and a EPUB of the same document, and read it on the same device with the same version of Android, which would use up less battery power?
Answer: Theoretically ePub should have the advantage over PDF as it is a smaller file that is basially HTML, CSS and image files with a few XML files for defining the books metadata, chapter order and table of contents navigation zipped into 'ePub' format. It is in many ways like a website. The PDF files will often be larger as they have embedded fonts, image optimisation and their own encryption to deal with as overheads.
However, while ePub will reflow text easily it is not very good for more technical things like code and mathematical equations etc, so really what format to have the book in will depend on your need rather than an impact on the battery.
Also the more optimised the eBook reader the less overhead on your battery. The screen is the biggest drain on nearly all mobile devices and will consume far more battery than any eBook reader.
Conversely, an ePub with a LOT of markup and very, very large unoptimised image files could be a bigger overhead to render than a slimmed down, lower image quality PDF.
As per @Chahk 's comments below, the actual saving for a black background is quite low for an AMOLED screen where black is unpowered, and non existant on LCD based technologies.  This XDA user did an experiment  which should be taken as anecdotal evidence and his finding was basically after 1 hour of screen on time he had saved around 6% battery life.
 How to Geek article on black wallpaper and battery which states:

On most computer displays, such as the computer screen you're probably reading this article on, using a black background won't save you any battery life. No matter what color a pixel is – whether it's dark black or blinding white – there's a backlight at the back of your screen and it's constantly outputting light. The black pixels block more of the backlight, but it's still behind the black pixel, using power.
Comment: Honestly, the difference in processing power between various formats is minuscule in comparison with the power drain from having the screen on.  The reading app itself will probably not even register on `Settings -> Battery` graph.
Comment: I second tis very good explanation (+1). Having the choice between ePub and PDF (my favorite reader supports both), I decide based on the book's content. If it's just a good story (novel etc.), or is mainly text with no special formattings, I always pick the ePub. But if special formattings are important, or a lot of graphics are used (mainly with technical references, as RossC pointed out), PDF is the better choice: Even if an ePub theoretically might save some juice, it wouldn't if I need to read the same parts multiple times, as formatting issues (text re-flow) made understanding difficult.
Comment: @Chahk completely right, that's why I had to point out `the screen brightness and having a white background will drain battery far faster than a PDF reader or an ePub reader `  The screen will burn the battery faster than nearly anything on a phone, the only exception is that unoptimised mess in Google Play Services with the location etc, that they are trying to fix.
Comment: @Chahk thanks, I've put the screen part in bold, and elaborated on the Black Screen, which I was incorrect on. Many thanks again, that's great! I think the answer is better now.
Comment: What reader do you use?
Comment: @RossC I saw that (and +1'd the answer for it), but I think it should be emphasized more.
Answer: EPUB uses less battery because pdf files heavy compared epubs. It also depends on what app you are using, CPU speed and RAM of device. Reading EPUB file with black background n white text saves a lot of battery.
Comment: Black backgrounds only have (marginal) impact on battery life on AMOLED screens, where truly black pixels are unpowered. LCD based screens don't have this feature, and so they don't benefit at all from dark backgrounds.
Comment: There is a difference on AMOLED, but it's not as much as one (myself included) would have thought. You raise a good point. This thread: http://forum.xda-developers.com/showthread.php?t=660853 is one person's experiment and he found that after 1 hour of screen time he had a saving of 6% which frankly isn't worth having a dark background. Very interesting. Cheers for the  heads up @Chahk


The star that created our sun

Question: Is the location of the star that would have created our sun known? Meaning our sun's parent star which would have provided the material when it died? If not, has there been any theories on what kind of star it would have been, it's age, mass etc? And would our sun parent star created other near by stars like Proxima Centaurea?
Comment: Also, the nearby stars like Proxima Centauri were probably not nearby 4.5 billion years ago. See https://astronomy.stackexchange.com/q/43425/16685
Comment: Related: https://astronomy.stackexchange.com/q/54577/16685 & https://astronomy.stackexchange.com/q/28077/16685
Comment: @PM2Ring This is great, thanks for these two links. They go some way into answering my questions.
Answer: There is no single progenitor of the Sun. The material that makes up the Solar System (or at least the elements heavier than helium) were made in approximately a billion stars that lived and died before the sun was born. See https://astronomy.stackexchange.com/a/16313/2531 .
The one billion number is an order of magnitude estimate for the number of stars more massive than the Sun that have been born in our Galaxy and died more than 4.6 billion years ago. Mixing processes within the interstellar medium are then quick enough to disperse this material, to a greater or lesser extent, around the Galaxy.
There is speculation that the protosolar nebula may have been seeded with the detritus of one or two nearby supernovae, but that hypothesis is made simply to explain the presence of some short-lived radionuclides in the early Solar System. These events, if they happened, cannot have provided the bulk of the heavier elements in the Sun and planets (or the hydrogen and helium that come mainly from the big bang). On the contrary, there is evidence for many, many progenitors found in the diverse isotopic ratios found inside small mineral grains trapped in meteorites.
The stars that are near the Sun now were almost certainly nowhere near it when the Sun was born. Stars have relative motions of tens of km/s (or tens of pc per million years) and can also migrate radially by thousands of pc during their lives.
Comment: In order to visualize the last point you make, I can encourage to set time to -+100000 years in stellarium. You will not recognizer most constellations
Answer: This supernova exploded about (somewhat before) 4,568.2  million years ago (the likely age of the oldest meteorites dated to time, source).
It was not the only source of the material for the Sun, but the shock front from this supernova has hit the protosolar nebula, causing it to collapse and new stars to form (including the Sun).
Isotopically anomalous material from the supernova might be found in some parts of our Solar system. You can read about this here, even if so far these super-old events may lack evidence. This star contributed much more material than "many other stars", but a big part of it also came from the cloud.

The star that created our sun


Starting out in WoW

Question: Quick scenario before my question(s):  I bought WoW right when the WotLK came out - Toys'R'Us was running a ridiculous Black Friday sale where I nabbed WoW and the two expansions for around $50.  I figured what the heck, I'd give the game a try.  I started with my free month with a Drawf Priest (perhaps not knowing any better) on a RPPvP realm.  It was fun, but I didn't experience as much interaction and party questing as I had figured.  After my month trial I didn't renew and just went on with other games to fill my spare time, it was fun, but not $13-$15 per month fun.  Blizzard, apparently trying to ramp up sales for Cata, offerred me a free 7 days of game time.  So I reinstalled and am deciding to give it another shot:
Questions for the gaming.se crowd who are WoW players:

What advice would you give to someone starting out with WoW in general?  I'm a bit of a casual gamer - getting somewhere between 7-14 hours a week of gaming and just want to have fun.
What's the best place or resource to find other gamers to quest with, both in-game and out-of-game.
Should I play on a PvP or PvE realm?
What should I be reading online to educate myself on WoW, in general?
Answer: This is a good question for the "un-initiated". Just buy a game card and start playing. Cataclysm is coming but it's a few gigabytes of updates. Blizzard's launcher is pretty smart by pre-downloading content ahead of release, so you can just log on and play when it's officially released. So, to avoid disappointment with Cataclysm. Start downloading now.
PVP or PVE?
With PVP realms, there is a thing called "ganking", (Arqade discussion on ganking here), where groups of players just wait in ambush and just smack you senseless whilst travelling between cities or trying to complete quests for no reason apart from bulling players. If you like that sort of stuff, and want to PVP you can go this route. It does waste a lot of time when you want to go questing/farming and generally getting gear, though.
PVE has battlegrounds where you can engage in PVP play. I prefer PVE because you can get into PVP at your choosing, rather than getting ambushed every 10 minutes. PVE it's just you vs the environment. Not other players. PVE also has duelling. So, you can also pick a fight when you want to.
As a casual gamer. There is a built in quest helper, so this can speed up the grind of going around completing quests. If you're not playing constantly, then there is value in logging off in taverns and major cities, because you gain "rested XP" faster in taverns and cities, rather than logging off in the forests/roads. Rested XP basically is worth double the normal XP from kills and quests. You will level faster that way.
Best guides I have found are these:

www.wowhead.com

www.wowwiki.com

www.thottbott.com

Addons
Add-ons are enhancements to your WoW interface that can really improve game play. They have become an industry in itself, although Blizzard discourages people paying for them, you can get them for free.
You can find wow addons on Curse.
I use Auctioneer among others, but a good list of what's popular can be found here. There are class specific addons as well and you can keep them up to date with wowmatrix.
Instances
If you like raiding, I recommend that you get good at the 5 man dungeons (also known as "instances"). The key thing about instances or raids is to know the role you play in the group. It boils down to 3 different types, Damage dealers/Tanks/Healers. They're self explanatory, but Tanks are basically the one player who tries to hold the attention of the big boss you will end up fighting. This is so the damage dealers can kill it, and the healers, well... heal everyone.
Holding their attention, is called "holding threat". As the bosses or any mob you are fighting does a calculation to determine who they should kill, by estimating who presents the biggest threat. So, damage dealers tend to have high threat, because of their DPS (Damage Per Second). Healers can gain threat, because they're keeping everyone very healthy. You can improve your level of threat through talents or buffs. (A buff is like drinking a potion or a beneficial spell that gives you a special attribute for a period of time). You'll learn about which buffs are important to your style of gameplay as you progress. Finally, each instance tends to have anywhere from 3-12 bosses. You don't have to wait til you're level 80 to do raids, you can do them through level ranges of character, but the first one to do would be Stockades in Stormwind (if you're alliance), when you're about level 15, and you should go in with at least one or 2 other players of similar level. You can find dungeon groups through the dungeon finder. There is also a "raid browser". It's all built into WoW. The trade chat channel tends to have lots of offers/requests for player to join raid groups. If you do get hooked on raiding (as I expect you will), better to look for a guild to join because once you start doing 10man or 25 man raids, you need a reliable group of people to run the instances, because random or ad hoc groups can be painful, if you get the wrong group of people together.
Terminology in WoW
Basic dialog/lingo in the trade channel is like this.
LFM = Looking For More.
LFG = Looking For Group.
GS= gearscore
So, someone might say LFM Ony= Looking For More players to do the Onyxia instance. or Say LFM ICC min gs5500 = "Looking for more for Ice Crown citadel, minimum gearscore is 5500". You'll get to know the lingo as chat with people.
Trade chat is global across all cities. But only available in the cities. You can't see trade chat outside of cities.
Also, you might hear about "Gearscore". This relates to the quality of all your gear you wear. Each item you have has an "item level". The higher the item level, the better suited you are for the harder instances. The top item level (pre-cataclysm) is 264.
Gear and Items
You can acquire great gear by making it/buying it/looting it. The auction house can be good in this way to buy gear from other players. You can also buy very exotic gear from special merchants using tokens. There is a large array of currencies for different levels of gear. Blizzard are now unifying it, you got 2 basic "token" currencies, Justice Points and Honor points, (This is different from gold/silver/bronze). You earn them by doing raids or PVP. There is also some gear that you can buy from merchants, by trading other exotic items, but this is the highest level stuff (level 80).
The quality of gear you have determines whether you can do higher level instances. That's what Gearscore works out for you. There is an addon for gearscore. Get it. Players will sometime ask for people who only have a certain level of gear. They're basically trying to keep out the riff-raff, so these can be good raids to get into even though they are ad-hoc. This is common for trying to do ICC (Ice Crown Citadel instance).
At the end of the day, just do whatever you find fun in.
Comment: I'd actually cross-link our own question on Ganking -- I didn't edit it into your post, but you might want to: http://gaming.stackexchange.com/questions/5727/what-is-ganking
Comment: One comment from me - I would NOT recommend Stockades at level 15, as you've written, especially not with only one or two other players. That's pretty much guaranteed death. A level 15 player could queue up with the Dungeon Finder for Ragefire Chasm, and only a few levels after, the next set of dungeons available (roughly level 18) would be Deadmines and Shadowfang Keep. Stockades is just after those and is generally a level 22-25 endeavor.
Comment: A correction: Turning in quests does not consume rested XP.
Comment: I added it .. :)
Comment: @Q. I know what you mean about "certain death". It is possible with 3 level 15's but you gotta do it slow and careful. Good practice in not pulling too many mobs. The mini-bosses are a bit frightening with 3 but it's good fun.. Actually, I found Hogger to be a pain in the butt... But that was when I'd try and pwn him at level 10-11 with a mate..
Answer: I would wait until December 7th for cata to begin playing again. You will be leveling with a fresh batch of players and alts, which will make it much more enjoyable, and the whole old world is getting an overhaul which will streamline quests and reduce boredom and tedium.
1) Play what you want to play
- Tanks and healers can find groups faster, true, but if you don't enjoy what you're doing in a group then what's the point? 7-14 hours a week is plenty to get 95% of what wow has to offer.
2) Your best bet is getting on a server with a large population. Wow will recommend you join a server with a low population. This might be better for them, but it's not so much for you. You can use http://www.warcraftrealms.com/census.php to figure out what realms are most populated during your usual play times. If you have any real life friends or co-workers or anything that play wow, it might be worth it to go to their server and try to join their guild. Finding an active guild will make the difference between an enjoyable wow experience and a boring one. You can also find guilds via the realm forums on worldofwarcraft.com
3) This is mostly a matter of taste. If you enjoy bullying people around and messing with them and don't mind being messed with, play PvP. If any part of that equation does not sound good to you, play PvE.
4) wow.joystiq.com has lots of newbie friendly articles. I would start reading that every day. Elitestjerks.com has most of the science geeks to figure out what specs and rotations and equipment selections are optimal for all the classes and roles.
Comment: Though to be fair, you'll probably want to avoid EJ for the first little bit - it can be rather overwhelming.
Comment: Isn't it our duty to give him advice, so he doesn't have to @GalacticCowboy?
Comment: voted up despite not giving the answer.  thanks for your help and insight!
Answer: There's been some cool things posted here, but I thought I'd add a few thoughts.
1) Take a little time to figure out what type of character you feel like playing.  You might as well play something you like.  Do keep in mind that a Priest isn't likely to be very good at offense, unless you go with a Shadow Priest.  If you want to try a little of everything, try a Druid - their shapeshift lets them slip from a healer, to a damager (cat form) to a tank (bear form).  Choose 'Feral' once you get to 10th level to be able to improve your animal shapes.  (There's also a swim form which can breathe underwater and a 'travel' form that runs fast.)  But these days darn near any character class can work well enough on it's own.
2) Check around any other forums you hang out on for an offtopic section, and then search in there for World of Warcraft - it could be that people who share interests with you may already be playing in Wow, and if you play on the same server as them, you can see if they have a guild you can join.  Guilds often help out new characters with better equipment (read: bags) and the like.  Even if they don't have a guild, it's nice to know some folks on the server who you can chat with.
3) Have some fun with the professions.  Skinner/Herbalist is good for picking things up as you go and turning it into money, but lots of other combinations involve gathering something that a second profession turns into cool items, which works for either crafting armor, weapons, potions, or whichever.
4) Take it easy and enjoy yourself.  These days WoW has some of the most fun gameplay just wandering around and trying things out.  Other than the basic class/race combo, it's pretty easy to change your mind on anything you choose early on - you can retrain professions, you can start a profession when you're level 50 or 70, you can 'respec' and rebuild your character's talents.  And there's tons of guides online to help you play - some of them are going to be a little out of date right now that they just blew up the world, but soon they'll correct themselves and be very useful.
Oh, and get the auctioneer addon.  It's wonderful.
Answer: I know it's a little late to chime in on this topic now... you're either playing it or not at this point.  But I think the biggest thing that will decide how much you enjoy the game is a pvp vs pve server - especially for a casual gamer.
If you're casual, I'd probably go on a PVE server as this will prevent higher level toons/jerks from swooping down from the sky and smacking you dead.  This keeps pvp in the battlegrounds and keeps it there unless you want to run around flagged for kicks.
The only argument I can say for a casual gamer going to a PVP server is if you like that sort of suspense of running into the opposing faction at any given time while you're questing.  And there is a chance that you could run around being the jerk - swooping out of the sky and smacking lowbies dead... but as a casual gamer, this might not happen for a long while.  Plus, I'm not sure how easy that is as a priest.
In short (shorter than all that up there), I'd say plant yourself on a pve server, lvl a toon, and when you get closer to the upper lvls of your bracket (10-19, 20-29, 30-39, etc...) hop in a battleground and have some fun!  Pvp can really be a blast unless you're just trying to lvl and some jerk swoops out from the sky and smacks you dead.
Cheers!
Comment: I love the suspense of pvp servers and occassionally being forced to innovate new tactics. Parachute cloaking off a cliff to avoid a ganker ftw!
Comment: hehe - oh yeah. I have a pally w/engineering.  Nothing like the rocket belt to catch new prey and escape a beating from 6 incoming opponents. Love that thing! Engineering ftw =]
Comment: Sounds like ganking is more prolific than I remember it on PVP servers.. Has Blizz modified the WoW to limit this sort of stuff when it becomes bullying ?
Comment: Really it's not that bad.  Gankings are few and far between. Has Blizz done anything to limit it? Nothing outside of the main cities. Inside the main cities the biggest difference happens to rogues - guards see through vanish now so your only escape is vanish + sprint + run around a corner and then some ={
Answer: One thing not mentioned...look for a casual guild/clan to join to get consistent group questing
Answer: The biggest difference between enjoying your time spent in an MMO or not is the people you are playing with. And the biggest difference maker in finding good people to play with is to find a good guild.
While it is possible to find a good guild in-game, your best bet is to find an established guild outside of WoW itself. Check with any friends or co-workers to see if anyone knows of a good guild. If you are part of an online community, they might have a WoW guild you can join. Having regular people to converse with and get help from can really make a game enjoyable instead of just bearable.

Starting out in WoW


Are all languages in every switch cartidges?

Question: If I buy a Japanese cartridge of a game which is/will be released in Europe, will I be able to play in Eureopean languages?
Comment: Why would region locking have anything to do with languages?
Comment: I didn't mean it that way. Actually I have tested playing with a JP cartridge on my french 3DS (with the tricks to get it region free) and the game actually had french in it (it was with Kirby Plaet Robobot). While the game wasn't release outside of japan, by the way.
Answer: You can change the system language to something else in System Settings -> System -> Languages. The language in games such as Zelda will be defaulted to whatever your system language is.
"If I buy a Japanese cartridge of a game which is/will be released in Europe, will I be able to play in European languages?"
The answer is Depending on the game
Comment: This answer is correct, not sure why the DVs. Whether or not the release of a game on the JP store includes non-Japanese languages will vary from game to game.  There have been examples where English (at least) was included on JP releases, and examples where it wasn't.
Comment: I can confirm that not all cartridges include all languages. At the very least, *Fire Emblem Warriors* has a Japanese voice pack DLC, which is not available (nor necessary or useful) for the Japanese version of the game.


ISO 9001: a company does not store the customer contracts properly. What ISO requirement is being violated?

Question: As a part of my quality improvement activities, I wanted to fix some of the issues in our company (like contracts not being stored properly). I thought there will be a clear requirement/clause in ISO 9001, but I could not find anything relevant that I could use as a reference to our management. Would anyone who knows this standard be able to advise?
Answer: Clause 8.2.1 defines contracts as one element of the broader topic of customer communication. 18.104.22.168 includes reviewing the contract before committing to an agreement to supply products and services. Depending on the contents of the contract, it may be an input containing requirements to the design process. A contract is not explicitly listed in 8.3.3, but I've seen contracts with process requirements in them, either directly or by reference to statutes, regulations, or standards (which are explicitly mentioned in 8.3.3).
Clause 4.4.2 requires that the organization shall "retain documented information to have confidence that the processes are being carried out as planned". Retaining the contract (along with communications about or redlines to the contract) seems to be an easy and straightforward way to demonstrate that contracts are reviewed prior to agreements to supply the products and services and when the contract differs from a previous version (126.96.36.199).
Given those clauses, contracts would likely be documented information that support the "planning and operation of the quality management system", 7.5.3 regarding the control of documented information would apply and the organization would likely be expected to have control over distribution, access, retrieval, use, storage, change control, retention, and disposition of documents.
Unfortunately, ISO doesn't get into the goodness of a process. It's more about following a fairly consistent process and being able to provide evidence of it. I'm sure that an organization can define ways to control documents and records that check all of the boxes of ISO 9001 but would result in what I would consider to be improper control.
Comment: Thank you! One additional thing - I have seen many contracts stores just with the customer signature (not ours), which formally is not correct. However, I am unable to map it into any specific ISO clause
Comment: @JohnV I don't think ISO 9001 will get into that level of detail. ISO 9001 is more about having and following a process, rather than having and following a good process. If your process is that your organization doesn't have to sign the contract before accepting it, then it should pass the baseline for ISO 9001 requirements because you do what you say you do and have evidence of it.


What kind of plant is this ?

Question: It looks like baby tears to me and the vague label said succulent on it.
Answer: It's not Solierolia, common name baby's tears - that is not a succulent plant. This one looks like it might be Peperomia rotundifolia, sometimes known as trailing jade plant. It likes high humidity and bright light - but preferably not direct sunlight. Getting the watering right is critical - this is a succulent plant with very small roots, and it  does not require much water, especially in winter, despite its requirement for high air humidity. Further information here https://www.houseplantsexpert.com/trailing-jade.html

What kind of plant is this ?


How to show that $var(\hat{\mu}) < var(\bar{X}) $for a stationary process ${X_t}$, where $X_t = \mu + Z_t + Z_{t-1} $?

Question: If ${X_t}$ is a stationary time series with mean $\mu$ then the usual estimator for $\mu$ is the sample mean  $\bar{X} = \frac{X_1+...+X_n}{n}$.
Assume we have $X_t = \mu + Z_t + Z_{t-1}$, where ${Z_t}$ is a white noise $WN(0,\sigma^2)$.
Can we find an unbiased estimator for $\mu$ of the form $\hat{\mu} = a_1X_1+...+a_nX_n$ such that $Var(\hat{\mu}) < Var(\bar{X})$?
Comment: What have you tried so far?
Answer: Given the MA(1) model $x_t=\mu + z_t + z_{t-1}$, you can think of your vector of observations $\mathbf{x}=(x_1,x_2,\dots,x_n)$ as coming from an intercept-only regression model
$$
\mathbf{x} = \mathbf{1}\mu+\boldsymbol\epsilon
$$
where $\mathbf{1}=(1,1,\dots,1)^T$, $\boldsymbol\epsilon \sim N(\mathbf{0},\mathbf{\Sigma})$ and $\mathbf\Sigma$ is tridiagonal with $2\sigma^2$ on the diagonal and $\sigma^2$ on the two off-diagonals.
The general least square solution of $\mu$ is then unbiased and efficient and  is given by
$$
\hat\mu =(\mathbf{1}^T \mathbf{\Sigma}^{-1} \mathbf{1})^{-1} \mathbf{1}^T \mathbf{\Sigma}^{-1} \mathbf{x}.
$$
This is simply a weighted average of the observations with weights proportional to the sum of each column of $\mathbf{\Sigma}^{-1}$.  This MLE is also computed by the R arima function (by numerically maximising the likelihood computed via the Kalman filter) when fitting an MA(1) model including an intercept.
A closed form solution can be derived however. The entries of $\mathbf{\Sigma}^{-1}$ are given by
$$
(\mathbf{\Sigma}^{-1})_{ij}=\frac{\sigma^{-2}(-1)^{i-j}}{2(n+1)}
\begin{cases}
(n-i+1)j &\text{for} & j<i \\
(n-j+1)i &\text{for} & j\ge i,
\end{cases}
$$
see Huang & McColl (1997), eqs. (22) and (23).
From this, for odd $n$, one can show that the even columns of $\mathbf\Sigma^{-1}$ sum to zero whereas the sums of the odd columns are all equal so the MLE of $\mu$ is
$$
\hat\mu = \frac2{n+1}(x_1 + x_3 + \dots + x_n).
$$
This estimator has variance $\operatorname{Var}\hat\mu=\frac{4\sigma^2}{n+1}$, whereas the sample average has variance $\operatorname{Var}\bar x=\frac{4\sigma^2}n (1-\frac1{2n})$.
For even $n$ the weights of the MLE have a certain regular oscillatory behaviour. For example, for $n=12$, the MLE is
$$
\hat\mu=\frac1{42}(6 x_1 + 1 x_2 + 5 x_3 + 2 x_4 + 4 x_5 + 3x_6 + 3x_7+ 4x_8 +2x_9+ 5x_{10}+ 1x_{11}+ 6x_{12}).
$$


Where can I find some "must see" game development portfolios?

Question: I am trying to put together a website/portfolio and it would be great to see what others have done.
Comment: I disagree, even something that is not typically a visual, such as AI, can be shown in a way that is pleasing to the eye. Example: http://processing.org/learning/topics/flocking.html
Comment: Showing off code and showing off art or design are very different.  What specifically are you looking for examples of?
Answer: The first thing I'd do is read "Your Portfolio Repels Jobs" by John Jones. He covers what he looks for in a portfolio, and how to ensure people actually get to the content you want them to see. Check it out here => Your Portfolio repels jobs
Don't scrimp on your design. Do. Not. If web dev isn't your thing, jump on wordpress and get a nice magazine theme. It really makes a difference. Google is your best friend here, and no - you don't have to fork out for premium themes to make an impact :)
Here's some examples to get you started - Top 14 Free Wordpress themes 2010 - wpbloghost dot net/free-wordpress-magazine-themes
Rick Pierce's portfolio is what you should aim for. Do not aim lower!
I'm also a massive fan of Pior Oberson's CV (pioroberson dot com). It was good enough to get him a job at Blizzard, so he's done something right.
I hope that helps! It certainly helped me get my foot in the door as a 3D artist.
N.B. Sorry about the spelled-out hyperlinks; new users aren't allowed to post more than one
Comment: I personally did not like Rick Pierce site at all, not sure why, maybe its more artsy then im used to?
Answer: Even though not exactly an example, this discusses some DOs and DONTs of demo reels and portfolios for programming positions. It also discusses a few examples of existing portfolios and what was good about them and what wasn't.
How to Make a Game Programming Demo Portfolio
Answer: John D. Carmack's portfolio :D
Comment: Pretty sure the question was asking about the best way to show off things, not just showing off impressive lists.


Add a UIImage on top of CATiledLayer

Question: Is it possible to draw a UIImage on top of the CATiledLayer. The main idea is to note the position on the view. I have used PhotoScroller example from Apple Library and I am trying to add an UIImage on top of the tileRect. Any help will be appreciated.
<code>- (void)drawRect:(CGRect)rect {

CGContextRef context = UIGraphicsGetCurrentContext();

    /**** Trying to add UIImage on top of CGRect rect. But not working.****/
CGRect pointRect = CGRectMake(100,100,32,32);
UIImage *image = [UIImage imageNamed:@"map-pointer32.png"];
[image drawInRect:pointRect];

// get the scale from the context by getting the current transform matrix, then asking for
// its "a" component, which is one of the two scale components. We could also ask for "d".
// This assumes (safely) that the view is being scaled equally in both dimensions.
CGFloat initialScale = CGContextGetCTM(context).a;

NSString *value = [NSString stringWithFormat:@"%.3f", initialScale];
CGFloat scale = [value floatValue];

CATiledLayer *tiledLayer = (CATiledLayer *)[self layer];
CGSize tileSize = tiledLayer.tileSize;

// Even at scales lower than 100%, we are drawing into a rect in the coordinate system of the full
// image. One tile at 50% covers the width (in original image coordinates) of two tiles at 100%.
// So at 50% we need to stretch our tiles to double the width and height; at 25% we need to stretch
// them to quadruple the width and height; and so on.
// (Note that this means that we are drawing very blurry images as the scale gets low. At 12.5%,
// our lowest scale, we are stretching about 6 small tiles to fill the entire original image area.
// But this is okay, because the big blurry image we're drawing here will be scaled way down before
// it is displayed.)
tileSize.width /= scale;
tileSize.height /= scale;

// calculate the rows and columns of tiles that intersect the rect we have been asked to draw
int firstCol = floorf(CGRectGetMinX(rect) / tileSize.width);
int lastCol = floorf((CGRectGetMaxX(rect)-1) / tileSize.width);
int firstRow = floorf(CGRectGetMinY(rect) / tileSize.height);
int lastRow = floorf((CGRectGetMaxY(rect)-1) / tileSize.height);

for (int row = firstRow; row <= lastRow; row++) {
    for (int col = firstCol; col <= lastCol; col++) {
        UIImage *tile = [self tileForScale:scale row:row col:col];
        CGRect tileRect = CGRectMake(tileSize.width * col, tileSize.height * row,
                                     tileSize.width, tileSize.height);

        // if the tile would stick outside of our bounds, we need to truncate it so as to avoid
        // stretching out the partial tiles at the right and bottom edges
        tileRect = CGRectIntersection(self.bounds, tileRect);

        [tile drawInRect:tileRect];

        if (self.annotates) {
            // [[UIColor whiteColor] set];
            CGContextSetLineWidth(context, 6.0 / scale);
            CGContextStrokeRect(context, tileRect);
        }
    }
}
}
</code>
Answer: Probably the best solution would be to add the image in separate view, without any catiledlayer.
You can add an empty view, and add the view with the the catiledlayer an the uiimageview to that view.

Add a UIImage on top of CATiledLayer


How do I reset the Buffalo AirStation HighPower N600 Gigabit Dual Band Wireless Router WZR-600DHP to factory settings?

Question: This is quite a stupid question; I apologize in advance.  I was trying to configure my Buffalo WZR-600DHP to connect to a VPN and send all traffic through it.  I've managed to completely screw up the routing table, so I want to reset the unit back to factory settings.  Unfortunately, I can't for the life of me find the reset button.  As I am visually impaired, the diagrams in the manual, if any, do not help me.  Can someone please describe the location of the reset button on this type of router?  I've spent all morning trying various buttons and places that look like pin-hole reset buttons, and just haven't had any luck.  This is incredibly embarrassing!
Comment: Those models have the option to firmware-default via web interface. Is it not possible for you to gain web access? Nor telnet or SSH? Even if routing table is screwed, the routr should have any IP address, so you could find it using something like "netdiscover" (Linux).
Comment: Unfortunately, whenever I connect to the router, it tries to send the traffic for 192.168.11.1 through the VPN now, so obviously accessing the administration interface fails.  But I'll try taking off the support stand after lunch; thanks for that idea!
Comment: The accepted answer is correct. Once the stand is off, the button is easy to find. Thanks!
Answer: I had just the same problem with my Buffalo WHR-HP-GN (very similar to your model).
After a long time searching for it, the reset button was behind the support foot, the stand that makes the router remain in vertical position.
In my model removing this stand was not easy, and I finally broke a bit the piece. Good luck for your attempt.
Comment: My model may differ slightly but I noticed there is actually a small hole directly in the center of the support foot allowing you to reset the router without removing the stand. ymmv.


How do you manage dying leaves on young plants?

Question: If a leaf on a plant is shriveling or yellowing, should you cut it off or leave it there? If you do the former, should you only snip off the damaged parts or should you cut off the entire leaf? My question is pertinent to young plants that may have only around 15 leaves, so each leaf is relatively important.
Answer: The only time you usually remove leaves which are slightly damaged or part dead is if the plant is highly ornamental and it's detracting from its appearance, or the leaf is damaged by some kind of infection or invader. Otherwise, just wait for the leaf to shrivel and fall off naturally, or remove it when it's at that stage.
Comment: Are there benefits to leaving dead leaves on the plant? In my observations, once a leaf has yellowed or shriveled, it never rehabilitates. Is rehabilitation even possible?
Comment: @JoJo - no, no benefit as such - but there's much less risk you'll damage the plant if you wait for nature to deal with the leaf than your going in with scissors or snips before its ready to drop off. Cutting it before its dead means exposing interior tissues which may still be live - pulling  it gently, or snipping once its shrivelled doesn't do this.
Answer: There is always a reason for shriveling and yellowing. Taking care of the cause is the best thing for your plants health. If the leaves are dying naturally of old age, on most plants, you can cut off the leaves when the last green fades out. If the plant is disease prone or bleeds badly, wait until the leaf is entirely dry.
Comment: These are the leaf problems that I am personally trying to solve: **1)** Prime Ark Blackberry shriveled after one week of planting. The suckers seemed to be doing better than their parent ([photo](https://pbs.twimg.com/media/BnxQHpXIMAARQwE.jpg)). **2)** Lower leaves on my tropical Century Guava have yellowed, but not shriveled. Once completely yellow, they drop. New leaves are growing in to take their place ([photo](https://pbs.twimg.com/media/BnxQODBIAAEjmbA.jpg)).
Comment: @JoJo Wow... Are you watering the blackberry at all?
Comment: I water my blackberry twice a week. There's a Fall Gold raspberry plant just 6 feet away and I water it with the same amount, except the raspberry is looking lush.
Comment: @JoJo was the blackberry potted?
Comment: It was in a small plastic container in the nursery. I immediately planted it in the ground. I'm wondering if the dead cane is over three years old and died naturally. If something was wrong with the soil or watering, wouldn't all the canes die? But this is not so. The new suckers have recently grown quite rapidly.


Create windows XP's live USB using ubuntu

Question: My hard disk crashed.. I can run Ubuntu using a pendrive by making a live USB of Ubuntu, which I made using Windows 7.
In the similar way, I want to run Windows XP too using another pen drive (without hard disk) and I want to make it from Ubuntu (12.04).
The resources I have are Ubuntu's live USB, Windows XP and Windows 7 installation disk, some blank DVDs but no hard drive.
I have very basic knowledge of Linux.
Thanks
Comment: XP from USB is not an official supported deployment method.  While it is "possible" most solutions that actually do it are for the purposes of piracy.  Voting to close as too localised.
Comment: Installing another OS can not really be done from Ubuntu anyway.
Answer: http://www.iasptk.com/ubuntu-ppa-repositories/16958-ubuntu-and-winusb-a-simple-tool-that-enable-you-to-create-your-own-usb-stick-windows-installer-from-an-iso-image-or-a-real-dvd
WinUSB is a simple tool that enable you to create your own usb stick windows installer from an iso image or a real DVD.
This package contains two programs:
- WinUSB-gui: a graphical interface which is very easy to use.
- winusb: the command line tool.
Supported images: Windows Vista, Seven+ installer for any language and any version (home, pro...) and Windows PE.
Install WinUSB in ubuntu
Open the terminal and run the following commands
<code>sudo add-apt-repository ppa:colingille/freshlight

sudo apt-get update

sudo apt-get install winusb
</code>
Comment: WinUSB not working for XP, yes?
Answer: I've tried various approaches to this in the past, and in the end, there are a few possible ways you can do it, but nothing that is guaranteed to work.
For me, the easiest method is to install Hiren's BootCD which includes a copy of a "windows live" version with it.
Another method would be to create a BartPE install using a VirtualBox Windows VM.
With your given resources, you might install your Windows 7 copy in a VM, and use something like WinBuilder to create a legal live version of Windows 7. You can then boot into a live Windows 7 version from your USB.
For Windows XP, you can use the similar BartPE tool to build a live Windows XP install.


How will lawn tennis ranking be affected by losing earlier than previous year?

Question: Suppose a player has reached a higher stage in a tournament but failed to reach the same stage in the next year.
Can you explain how the ranking will be affected for each stage worse they are placed the next year?
Answer: Points awarded for ATP rankings are dropped after 52 weeks (slightly less than a year). So generally it doesn't matter what your previous performance in tournament X is; only your 'new' performance matters, and the awarded points are documented in various places, e.g. Wikipedia.
Of course, with the pandemic tournaments may be shifted on the calendar and affecting the ranking differently (it's a 24 month ranking right now IIRC), but let's hope that's a temporary situation...


After Effects: How to keep text same width through changes

Question: Using After Effects, I am trying to do a countdown of 5 minutes with a setup like this: 5m 00s, 4m 59s, 4m 58s... I have the countdown already set up with Slider Control. However, I'm trying to use a mask for each character separately, which I also mostly have under control, except I realized that the text moves when the width of the text box changes as the text changes, for example, 2m 00s vs 1m 59s because of the width of the character "1" is smaller than "2" in the font I am using. Is there a way I can make the text box width, specifically each character's placement, not change even while Slider is in use? I have already gotten started on creating changes to the mask each time it changes, but I have a feeling it will be a lot of work.
Answer: Option 1 - use a fixed width font, and make sure the text layer you create is left aligned. You'll need to select the text in your layer before you switch the paragraph to left alignment.
Option 2 -  Do something like this (I'm sure there's a nicer way to do it), but from looking at this script for countdown timers, and this script for finding the right character, I hacked up this:
Make a text layer for each character.
Make sure each text layer is left aligned.
Put this in the source text expression of each character you want to control:
<code>st = 300;
t = st - time;
c = timeToTimecode(t);
c = c.substring(4,8)
output = c.charAt(3);
output
</code>
Change the "charAt" variable for each position. Eg 0 is the furthest right character, and (3) would be the furthest left character (the minute).


If $a,b\in\mathbb R$ with $a<b$, then there is some rational $r$ with $a<r<b$.

Question: How do you prove this question? I was thinking proving contrapositive. But I was stuck..Thanks guys.
Comment: If $n$ is a natural number greater than $(b-a)^{-1}$, then $\frac{1}{n}<b-a$, so one of the numbers in the sequence $1/n,2/n,\ldots$ should work for you.
Answer: Hint: Let $\epsilon = b-a$.  There is an $n\in\Bbb N$ such that $\frac{1}{n}<\epsilon$.
Answer: We have that $b-a>0$. Let $c$ be an integer such that $c(b-a)>1$. Then strictly between $ca$ and $cb$ there is an integer $d$, so $ca<d<cb$, hence $a<\frac{d}{c}< b$, and $\frac{d}{c}$ is rational.
Answer: If $\mathbb R$ is defined in terms of Dedekind cuts, then $a<b$ means that $a\subsetneq b$, meaning there's a rational $r$ in $b$ but not in $a$. Then the set of rationals less than $r$ forms a cut $r'$ which is a strict subset of $b$. Also, since $r\notin a$, we have $a\leq r'$. If the inequality is strict, we're done. If $a=r'$, then if there is no rational strictly between $a=r'$ and $b$, then $r$ is the maximal rational in $b$, which contradicts being a cut. Thus, there is a rational strictly between $a$ and $b$.
Answer:
Lemma 1. For every real number $x$ there is exactly one integer $N$ such that $N \le x < N + 1$. (This integer $N$ is called the integer part of $x$, and is sometimes denoted $N = \lfloor x \rfloor$.)
Lemma 2. For any positive real number $x > 0$ there exists a positive integer $N$ such that $0 < 1/N < x$.

We now show

Proposition 3. Given any two real numbers $x < y$, we can find a rational number $q$ such that $x < q < y$.

Proof. By hypothesis, we have $y -x$ is positive. So exists a positive integer $N$ such that $0 < 1/N < y - x$, by Lemma 2. Since $xN$ is a real number, by Lemma 1, there exists a integer $n$ such that $n - 1 \le xN < n$, i.e., $n/N - 1/N \le x$ and $x < n/N$. Thus $x < n/N \le x + 1/N$. Since $1/N \le y - x$, i.e., $x + 1/N < y$, we have $x < n/N < y$. Thus $n/N$ is rational, the claim follows.
Answer: In fact this rational can be dyadic. Choose $x\in \mathbb{R}$. You can easily find $n, k$ so that
$${{k-1}\over 2^n} \le x < {k\over 2^n}.$$
That puts $x$ within $1/2^{n+1}$ of a dyadic rational.


Run JavaScript code when SPFX app is installing

Question: Is there any way to run JavaScript code when an SPFX app is installing. To be specific - I would like to change the permissions for the lists that are being deployed by the same app. If there is no out of the box way to do this, what is the preferred go-to method of running a piece of code once when the app is being added to a site.
Answer: Unfortunately, that's not possible. The way around it would be to have the code run when the SPFx app (web part/extension) executes and check if it needs to run the setup code or if it can skip it because everything's already in place.


How to detect XSS in GET requests?

Question: How to detect XSS in HTTP/1.1 GET requests? A request can be malicious and I want to know how to detect if the GET request to a server is trying to XSS my website?
Answer: You should not only protect yourself from XSS by scanning HTTP requests for attacks. Such a scan will never be complete, and there will always be some smart tricks that slip through the net. Your first line of defence must always be to properly sanitize untrusted data, so as not to create any XSS vulnerabilities in the first place.
For how to do that, see OWASPs cheat sheat on the topic. If possible, I would recommend you to set the Content Security Policy header strictly, as this will give you a solid defence on modern browsers. It even has a reporting directive that will instruct the browser to inform you about attempted attacks.
That said, for defence in depth it can be good to also scan HTTP requests to filter out any XSS attacks you can detect. Most web application firewalls, like Naxsi for Nginx, will do that. I recommend using an existing WAF here and not try to roll your own - there is no simple regex that will catch all XSS attacks.
So how does Naxsi do it? According to themself:

This module, by default, reads a small subset of simple (and readable) rules containing 99% of known patterns involved in websites vulnerabilities. For example, <, | or drop are not supposed to be part of a URI.
Being very simple, those patterns may match legitimate queries, it is Naxsi's administrator duty to add specific rules that will whitelist those legitimate behaviours.

By the way, it is not only GET request you have to worry about, but also POST or any other HTTP method. XSS attack vectors can be anywhere - in the URL, in the coockies, in the POST data, in the user agent header, etc, etc.
Answer: To be short I'd recommend you to download Arachni from here, start arachni_web (the WebUI) and to open the URL which will be displayed before. You will be able to test any web site for many existing problems inclusive XSS. I find Arachni very helpful.
UPDATED: If Arachni will find some problem that it will provide detailed instruction how you can reproduce the XSS attack on the example of some page of your site. You will see the exact GET or POST request which Arachni send to the server and the response. For example I found in the way an URL with the Searching form (not on my web site of cause) where an <input> field exist. One and type in the input the text ; /bin/cat /etc/passwd ; and the form will display the content of /etc/passwd. Everybody can reproduce the problem directly in web browser without Arachni. I find such practical example much better as long common theoretical description of the ways of XSS attacks.
Comment: I  want to know the logic behind it. not just use a tool and get the work done
Comment: @TilakMadichetti: Do you tried it? It displays very detailed descriptions and the instructions how you simulate XSS manually. It shows all HTTP request and response from your site in details and do many other things. Thus it's not just the tool which would say you: yes you have the problem, but explains XSS attack on example of some your page. Moreover XSS is only one problem. It could be that much more other problem exists too.
Comment: @TilakMadichetti: It could be for example some `` on your page (a searching for with input field), where any user can type `; /bin/cat /etc/passwd ;` and your form will displays the content of `/etc/passwd` file. You can open the form manually in web browser and reproduce the reported problem directly.

How to detect XSS in GET requests?


Why are high values of capacitance in low pass active filters not recommended?

Question: I am  designing low pass active filter (Sallen-Key structure) and I have come to a point where I have to decide what should be the value of C (C1 = C2 = C) and then calculate values of resistances. I know that capacitance can not be very low because then I would have to take into consideration parasitic capacitances of other elements on the PCB. I also know that it is not recommended to take high value of C but I do not know why.
Answer: High values of C would imply low values of R, therefore high signal currents.
In simple circuits (e.g. emitter followers) when the signal current is a large proportion of the quiescent current, you have to consider the device's nonlinearity (i.e. distortion). In op-amp based circuits, as long as the opamp has sufficient bandwidth and drive capability, this is a lesser concern.
In either case, high signal current means high supply current, i.e. heat and wasted power.
However, go too far in the other direction, and low signal currents mean high resistor values, and higher noise (both shot noise from the lower currents, and Johnson noise from the higher resistances).
The right balance depends on the application.
Answer: Define high. Anyway, there is a thumb rule: the bigger is the capacitor, the bigger ESR and ESL it has. Of course, ceramic caps are always better than electrolytes of same capacity, but the rule still works. Maybe i could tell more if i had more info on the application.
Comment: fc = 8 kHz, I have assumed that C1=C2, R1=mR, R2 = R. I have count m based on Q and K (gain). Now I wonder should I use C = 12n and R approx 3k or C approx 1u or maybe 1n.
Comment: 10nF is a nice value, but 1nF or 1uF are OK too. One consideration that i recommend: standard values. Another: if you care, think about output resistance, don't make it to high.
Answer: High value capacitors have lower leakage resistance associated with them. Certainly this depends on the type of capacitor used. If you use paper/mica capacitors their leakage is relatively lesser but they are often too bulky.
So if you want to generate 1 Hz, it is not difficult, but generating 0.001 Hz will be. So the method used to use a digital divider. Similarly row frequency (0.001hz) ramp is generated by digital means. Active filters can amplify the capacitor by miller effect and effectively solve lower frequency issues with not so high a capacitor. Some of the newer Farad capacitors may possibly solve many problems.
I have not tried these. But repeatability of an oscillating frequency will still be a problem due to their tolerance and temperature dependence.
It will be a good exercise to attempt to make a ramp growing from 0 to 10 volt in say 1000 secs. You will have to have a lot of patience to determine the repeatability if you change the temperature!


Radiation due to current

Question: Generally we equate change in potential energy to change in kinetic energy but in case of a charged particle like electron this is inconsistent. Consider a case: An electron(of charge e)from rest is accelerated in potential difference V then the final kinetic energy is given by
    KE=eV
 But we know that accelerating charges radiate energy then why are we not taking into consideration this form of energy when charges accelerate as in simple cases like flow current in wires etc.
Comment: Not sure what (if any) question you are asking - but conservation of energy is valid, even for electrons. It's just that "kinetic" and "potential" are not the only two forms of energy that need to be considered. You need the sum over all forms of energy...
Answer: Although these unbound accelerating electrons do radiate relative to their kinetic energy it is very small in a lot of cases and so can be neglected.  For example if you connect a wire to the input of an oscilloscope, the display of the oscilloscope will, amongst other waveform, show a signal at the frequency of the mains power supply.  Relative to the energies transmitted by the mains supply the energy of these em waves is very small.
Of course there are examples of the amount of em radiation emitted being significant.  Antennas and X-ray tubes are examples of this.
Answer: Conservation of energy is valid, even for electrons.
But when you look at electrons "accelerating in wires", it is worth calculating the relative energy lost due to radiation, to understand whether it's a term worth worrying about.
The Larmor Equation describes the power radiated by a charge $q$ accelerating with acceleration $a$ - it shows that power goes with acceleration squared:
$$P = \frac23 \frac{q^2a^2}{4\pi\epsilon_0 c^3}$$
Let's take an electron that is oscillating at 1 MHz - what fraction of the energy does it lose due to radiation in each cycle?
If the amplitude is $A$ and the frequency $\omega$, then acceleration $a = -\omega^2 A\cos\omega t$, and the mean value of $a^2$ over one cycle is $\frac12A^2\omega^4$. It follows that the energy lost per cycle is
$$E = P\frac{2\pi}{\omega} = \frac16 \frac{q^2 A^2 \omega^3}{\epsilon_0 c^3}$$
For such motion, the maximum kinetic energy is $KE=\frac12 m v^2 = \frac14 m \omega^2 A^2$. The ratio (fraction lost per cycle) is:
$$\frac{E}{KE} = \frac23\frac{q_e^2\omega}{m_e\epsilon_0 c^3}$$
for the numbers above, this evaluates to $7.5\cdot 10^{-16}$ - meaning it would take a really, really long time for these electrons to lose a significant fraction of their power.
Note that the fraction scales with frequency - so as frequency goes up, the fractional energy dissipated per cycle also increases (and the fractional energy per unit time goes as $\omega^2$, so even faster).
What this tells us is that it is hard to elicit bremsstrahlung from accelerating charges; and the fraction of energy used is small. For many problems where you are concerned with the dynamics and equations of motion of an electron, ignoring this effect will make an insignificant difference to the calculation.
Answer: Farcher and Floris have fine answers to this question.
I did want to point out that potential is not potential energy per charge. That kind of fiction can approximately hold in some situations, particularly for static charges and charges that are moved by forces that produce very very small accelerations.
It's like if you assembled some static charges to a particular locations and spent a huge amount of time assembling them. If you accelerated them slowly enough then the energy required to assemble them is really close to the electrostatic potential times the charge. But the actual energy required will depend on exactly how slowly you assembled them.
So you were lied to whenever someone said potential is potential energy per charge. Really, energy is exchanged between electromagnetic fields and charges.

Radiation due to current


Many's the hour - inversion

Question: Is it correct to say "Many's the hour have I spent listening to his fatuous ideas"?
I'm not quite sure if inversion is possible with "many's the..." My gut feeling says "why not?!", but my left hemisphere is dubious about it.
Comment: It works to my ear, though it makes the expression sound very old-fashioned and dramatic.
Comment: Have you googled "Many the hour's have I"? Or investigated usage on Google Ngrams?
Comment: @MikeGraham Neither old-fashioned nor dramatic to me – just completely ungrammatical.
Comment: In addition to it being an ungrammatical construction, two inversions in a row sounds awful, and pretentious.
Answer: With this exact wording, no. It would be ungrammatical. "I have spent..." is a relative clause to "Many's the hour," which is interestingly already inverted itself:
Many is the hour is like saying Fair is my beloved!
And the relative clause should follow as:

Many is the hour (that) I've spent listening to his fatuous ideas.

With its adverbial synonym "Many an hour," though, it would be perfectly fine:
From The Collected Works of John Buchan: Spy Classics, Thrillers, Adventure ... :

Many an hour have I spent by the big fish pond at Rohaine.

From The Visitor: Or, Monthly Instructor:

Many an hour have I and my playmates pelted that tree with sticks and
  stones.

Many's the hour - inversion


Make a cinema box around a video clip

Question: I am new to video editing so if my terminology is wrong, I apologize. I am making a video with output settings : 720p and dimensions 640 x 480. I am inserting a series of video clips but their dimensions are smaller than 640 x 480. Instead of the video clip slide expanding up to 640 x 480, I want it to remain the same size but have a black cinema box or border box around the video clip. How can this be accomplished with a video editor?
Comment: There's a disconnect here between "720p" and "640x480". These refer to different formats. This doesn't affect the answer (which AJ provided) but it could impact what comes out at the end of your process.
Answer: Just import the video and don't scale it.  Any decent NLE should support using clips at their original resolution and placing them within a larger format either scaled or unscaled.  Without knowing your intended NLE, I can't really offer any more advice than that.  Premiere Pro would certainly meet your needs.
Comment: Thanks AJ. I am using Windows Movie Maker (not an NLE?), but I will try Premiere. I solved my question by creating a 640 x 480 document in Photoshop with a black background, importing the video clip as a layer, then exported it as an mp4. This gave me what I needed.
Comment: @Briggs - Windows movie maker is technically an NLE, but it is not a decent one. :)  The problem you may run into is that a lot of consumer level stuff is going to auto-scale for you because they don't expect consumers to understand things like resolution.  You might find one that doesn't, but it'll be more or less default behavior to not auto-scale on any professional level NLEs like Premiere or Final Cut (at least the older versions), though if you are on Windows, Final Cut isn't an option.
Comment: +1 for identifying consumer vs. pro NLE issues.

Make a cinema box around a video clip


In an NFA, what if there are no transitions out of an accept state but there are symbols left in the string?

Question: Let's say I have a string 0110 and after 011 I reach an accept state (let's call the accept state "q") in an NFA. However, there is no transition mentioned in the diagram from q for the symbol 0. Does this mean the computation dies, or does this mean that the string is accepted?
Comment: It dies. Check the [definition](https://en.wikipedia.org/wiki/Nondeterministic_finite_automaton#Recognized_language).
Answer: A string is accepted by an NFA if there is a sequence of moves such that it can reach a final state at the end of the string.
As you said, assume that for $w=0110$ after reading $011$ we are in a final state (called $q$) and there is no transition like $\delta(q,0)$, this is when we encounter a situation called dead configuration. At this point we can't just say the machine stops, because it's not precise.
What we can say here is that no final state can be reached by reading $w$ so the NFA doesn't accept the string.
Answer: Finite automatas (either) DFA or NFA, must be process the entire input string.
DFAs will keep track of a single state while processing a string. Think of it as a pointer to the current state. It will transition (i.e. move that pointer) according to its rules while processing a string. Remember that for a DFA, all states must have a transition for each symbol in the alphabet. Thus, the DFA will have a unique path to the final state after processing the entire input string. If final state is an accepting state after processing the entire input string, the string is accepted; otherwise, it is rejected.
NFAs on the other hand will keep track of a set of states while processing a string. Think of it as having a set of pointers to all possible states for which the NFA could have transitioned to after processing a certain number of symbols. This allows for the NFA to not have all transitions defined, the inclusion of $\epsilon$ on transitions, and having a symbol on more than one transition out of a state. If the set of states contains an accepting state after processing the entire input string, the string is accepted; otherwise, it is rejected.
Take the following example:
$L = \{0,1\}^*00^+1 + \{0,1\}^*01^+0$. The following NFA accepts this language.

We can make a chart that shows how the NFA will process an input string. The left column indicates the current set of states (when we start processing we start with {A}). The middle column is the set of states possible from the current set of states after processing a 0, and similarly for the right column with 1.
              0         1
_________ | ________ | _______
{A}       | {A,B,C}    {A}
{A,B,C}   | {A,B,C,D}  {A,C,D}
{A,B,C,D} | {A,B,C,D}  {A,C,D}
{A,C,D}   | {A,B,C,D}  {A,C}
{A,C}     | {A,B,C,D}  {A,C}

Suppose we have an input string 001. The NFA will process the input:
0 from {A}       -> {A,B,C}
0 from {A,B,C}   -> {A,B,C,D}
1 from {A,B,C,D} -> {A,C,D}

We see that the final set of states is {A,B,C,D} which does contain an accepting state. Thus, $001 \in L$. Notices while processing the string, the NFA did not record the way it got to the accepting state; it just records that it is possible to get to one.
Suppose however we have an input string of 0011. The NFA will process the input:
0 from {A}       -> {A,B,C}
0 from {A,B,C}   -> {A,B,C,D}
1 from {A,B,C,D} -> {A,C,D}
1 from {A,C,D}   -> {A,C}

We see then that the final set of states is {A,C} which does not contain an accepteing state. Thus, $0011 \notin L$.

TL;DR
FAs must process the entire input. For NFAs, if the final set of possible state the machine could end in contains a final state, then the input string is accepted; otherwise, it is rejected.


Can the eldest sibling of three males call his younger brother "my older brother"

Question: Had this conversation with a 26 year old male.  He has finished a degree at Uni and told me I was wrong when I said you cannot call your younger brother your older brother.  He is only older son to your mother who would refer to her three sons as "my youngest son, my older/elder son and  my oldest/eldest son. He was so passionate about this (my three sons also told me I was wrong) I had to stop but at 47 I am wondering what is correct.
Comment: That his mother can say it does not mean he can say it. Nobody could think the sons are older than their mother. He can maybe say "the older of my two brothers" but "my older brother" is a set phrase meaning "my brother who is older than me."
Comment: "The oldest of my two younger brothers" would be explicit, although it leaves open whether or not you have an older brother. "The oldest of my two brothers, who are both younger than I" would be unambiguous.
Comment: Words like 'older' indicate the relation between things or persons, the person using tpsuch a word need not be one of the concerned persons. I agree it is ambiguous.
Comment: @PaddyLandau: Saying "the older of my brothers" would probably be just as good, since if the speaker were the middle child he would more likely say "my older brother", and if he were the youngest he would say "my eldest brother".  If the speaker had some affinity to two people who were brothers to each other but was not their sibling [e.g. he is renting a room to people whom the listener knows to be brothers], he could say "the older brother".  The choice of phrasing implies a lot about the relationships, even without stating it.
Comment: If he had three or more brothers all younger than himself he could say: the second eldest brother; the third eldest etc.
Comment: @supercat: Yes, you are absolutely correct. Context, tone of voice, culture and familiarity are all vital, which is one reason why it is so hard to program a computer to understand speech.
Comment: The key thing here is clarity, not logic. In most contexts if you say "John is my older brother" people would assume John is older than you are; you can't defend misleading people by claiming to be logical.
Comment: This question is language-agnostic and I think it belongs to [linguistics.se]. _Deixis_, which is arguably the one-word answer to this question, is even a tag on Linguistics SE which I only discovered after googling [this](https://english.meta.stackexchange.com/a/707/410969).
Answer: To take it from from a linguistic boffin's standpoint, I guess that "older" is a deictic word: its meaning varies depending on usage. There's a handy illustration at Wikipedia's page for deixis. When you say "my older brother" you put yourself in the deictic centre. Your listener then should figure out the position of your brother relative to that centre.
As WS2 rightfully pointed out, you may with a degree of certainty say "he's my older brother" to an acquaintance who knows that you're the oldest of the flock, but not to just any John Doe.
That's because deictic words require contextual information to be fully understood, and your acquaintance will know that while you're at the deictic centre there's no way for you brother to be at the.. er.. deictic "above", because there's a.. hm.. "deictic ceiling" of the fact of your being the oldest.
Answer: It would depend to whom he was talking. If it was someone who knew the family well presumably he would mention his brothers by name. If it was to someone who just happened to know he was the eldest, 'older brother' might just scrape in as acceptable speech. But if it was to someone who didn't know him or his family from Adam, for clarity's sake he would need to say 'The older of my two younger brothers'.
Comment: Or he could mix age-referents by referring to "my older little brother"...
Comment: +1. Also, I think if he said 'my older brother' meaning the older of his (younger than himself) brothers, it would be most natural for him to stress *older* [and follow up with a clarification!], whereas if he were talking about a brother older than himself, he would not need to stress *older* unless it was in contrast to his younger (than himself) brother.
Comment: I think saying "the older of my brothers" would imply the middle brother in a family of exactly three; "the oldest of my brothers" would imply the second-oldest in a family of at least three, and probably at least four, brothers.  The speaker would have no reason to use such phrasing rather than "My older/oldest" brother unless he was older than the person in question.
Answer: Here's one for you that ensued in a big argument. I have four older brothers. I referred to my next eldest, the third eldest as my youngest brother. I was told that I was dead wrong because he was not younger than me. But I am not wrong. It dosn't matter how you cut it he is still my youngest brother. I never said he was my younger brother, only the youngest of my brothers. Of my four brothers as a group, he is the youngest.
Can anyone out there logically contest this?
Comment: +1 for emphasizing the importance of perspective in this question. It seems to me that there are two ways to approach the analysis. If we take as our starting point the fact that there are five brothers in your family, then you are indisputably the youngest (of the five). But if we take as our starting point the fact that you have four brothers in the family, then the one closest in age to you is unquestionably the youngest (of the four).
Comment: There I would prefer "the youngest of my brothers" to "my youngest brother".
Answer: WS2 beat me to it, but here's another possible explanation...
In this case--you're both right. One can concoct a scenario where it is possible for him to justify calling his clearly younger brother an 'older' brother:
In the meaning you imply in your question, (and that most people expect when siblings use "old" or "young" as a comparative adjective,) older refers to the fact that one sibling has lived longer. So the sibling born first is old*est*, and old*er* than the next, and so on. The sibling born last is young*est*, young*er* than the next, and so on.
There is another meaning for older. In essence, older simply means 'has more age than', and so it is important to specify the frame of reference. What your son could be claiming (although he is really just being a pain) is that if he knew his brother a certain point in time in the past, and he still knows him now, then your youngest is actually, older.
He is "older" in that he has now accumulated more age than his previous self.
Comment: And if you aren't careful you end up as your own grandpa. http://en.wikipedia.org/wiki/I%27m_My_Own_Grandpa
Comment: Yes, very contrived! But he would't say 'my older brother now goes to secondary school'. In that context he would say 'Now that my brother is older he goes to secondary school'.
Comment: @WS2 It depends on how pedantic he wanted to be. I would argue that based on the above, he could indeed say that "my older brother now goes to secondary school."
Comment: Not without sowing confusion. We are into the realm of Christmas-cracker riddles here. If my parents divorce at the same moment as my wife and I. My ex-wife marries my father, they have a child which is the younger brother as well as the uncle of the child she had with me. Or something like that. You know what I mean, if you take it all far enough you end up with someone being the aunt of uncle of themselves.
Comment: @BrianDHall And if you're even more not careful, you could [end up in the Rolling Stones for that](http://en.wikipedia.org/wiki/Bill_Wyman#Personal_life)!
Answer: If Abe, Ben, Cindi, Dave (listed young to old, with Abe, Ben, and Dave being male) are the siblings in a family, then Cindi can unambiguously refer to Abe, Ben, and Dave as follows:

• Abe: "my youngest brother" or "my younger younger brother"
  • Ben: "my older younger brother"
  • Dave: "my older brother".

The phrase "my younger younger brother" is most likely
to be used only facetiously or sententiously, since phrases "my youngest brother" (when there are more than two other brothers) or "the younger of my brothers" (when there are two other brothers) typically serve better.  But phrases like "my youngest younger brother", "my youngest older brother", "my older younger brother", "my younger older brother", and "my oldest younger brother" all serve useful purposes in different cases.
If Cindi refers to Dave as "my oldest brother" rather than "my older brother", the listener isn't told whether Dave is older vs younger  than Cindi; some listeners might assume Cindi is older than all her brothers, some may assume she is younger, and some will realize they don't know.
Answer: It seems to me that it would be correct, provided you've already excluded yourself from the group you're referring to. Like others who've posted here, I agree that it could lead to some misunderstandings and should be refrained from. When I grew up as an only child, I ran across the same sort of situation with the large number of cousins in my family.
Because he made it clear that he was the oldest child, he had already defined boundaries which excluded him from the group of "my younger brothers." However, this could make sentences confusing.
"I'm the oldest of three brothers. We all run a deli. My youngest brother works in the back while my older brother takes orders at the counter."
Saying "the older one" would work better than saying "my older brother." However I believe the statement can still be understood. We could also employ the word elder here to avoid some of the confusion in using older/younger together.
"I'm the oldest of three brothers. My youngest brother works in the back while my elder, younger brother takes orders at the counter."
"The older of my brothers." Comes across as a grammatically awkward statement. It doesn't sound right when I attempt to annunciate it. I could be wrong, since I don't have a PHD and am just an ESL teacher, but it doesn't sound smooth.
I have also heard people differentiate which younger or older sibling they were talking about by using bigger and smaller. "My big, younger brother ate the cake."
Answer: You were right and he was completely wrong. As he is the oldest of three brothers, he can't have any older sibling(s) because he is the oldest. And if he doesn't have any older sibling(s), he can't have an older brother. So it would be grammatically incorrect if he called his younger brother "my older brother". "Older brother" means a brother who is older than you. And in his case, his brother was NOT older than him so he was wrong.
If he argues with you, tell him: "You are the oldest child in your family. You only have two younger brothers. It would be completely wrong and unacceptable if you called him "my older brother" because he is not older than you. In fact, he's younger than you. That's why he is your "younger brother" and not your "older brother."
He can refer his second-youngest brother as "my younger brother", "my second-youngest brother" or "my middle brother." But referring him as "my older brother" is grammatically wrong and unacceptable. It's like saying "I is eighteen years old" instead of "I am eighteen years old."
Comment: No. 'Older' is deictic, and needs a frame of reference. For instance, 'my older uncle' without qualification can mean *either 'the older of my two uncles', 'my uncle who is older than me' (restrictive/defining), or 'my uncle, who is older than me' (non-defining).  One can't be certain whether the speaker themself is included in the comparison. // * The legitimacy of 'either A, B, or C' has been discussed; OED allows it.
Comment: But you can't call your younger brother "your older brother." It's just not correct. Do you know what "older brother" means? If you don't, I'll tell you. Older brother (or elder brother) is a brother who is older than you.
Comment: This is all very confusing. I'd like to see multiple examples of: ages of people, who is speaking (one of the brothers, a sister their mother or someone outside of the family and what their age is), and who they are talking about. Otherwise we're circularly using the same words to describe the words we're trying to explain. I can't figure out what the OP is saying either.
Comment: Are you prepared to listen to the voters many who regard 'If it was to someone who just happened to know he was the eldest, 'older brother' might just scrape in as acceptable speech' (WS2) and CowperKettle's parallel comment on needing to be sure the deictic centre is understood by the addressee as being valid, rather than just trot out 'the most obvious and default usage (or worse, the only one I've come across) is the only one used/acceptable'?
Comment: An older brother is a brother older than the person. He could say "oldest brother" (which is acceptable if the other person knows he's the eldest). It's just like I don't call my younger sister "my older sister".
Answer: Consider:
"My siblings are not so nice to each other. My sister is still very young - it is horrible that she is always being bullied by my older brother. "
First I give a context in which I am comparing my siblings among each other - making the interpretation of 'older' as 'older than me' less likely. Furthermore, I talk about my young sister, to contrast her youth to my brothers relative oldness. Also I talk about my sister instead of my brother, so as to make it more logical to use the phrase "my older brother" instead of "the older one". I think all these factors should lead one to believe that I am calling the brother older in comparison to my sister, and not to myself.
In these circumstances I wouldn't know any other way to make clear that the relative oldness of my brother is in comparison to my sister, instead of me. Therefore, anyone would be justified in interpreting the sentence the way I meant it.
Comment: Actually, I read your statement as indicating that the brother is older than you. It would have made more sense to say that "…she is always being bullied by *her* older brother," to convey the meaning you intend.
Comment: OK, then what about "My siblings behave worse than yours. My sister is still very young - it is horrible that she is always being bullied by my older brother. "
In that case it would make more sense to use 'my', in order to emphasize that I am talking about my siblings instead of yours.
Comment: I guess my principal statement is that it can be correct to interpret 'my older brother' as referring to my brother which is older than someone else as me, whenever the one who uttered the thing did in fact mean that, and was inclined to use this somewhat confusing way of saying it due to context. The empirical question of the existence of such context shouldn't make a difference for answering the question whether it is possible to refer to your younger brother as 'my older brother'. The fact just is that 'older' isn't **necessarily** interpreted as 'older than me'.
Comment: I agree that it's possible to construct a context where "my older brother" successfully coveys the meaning of a brother that's younger than you. I still don't think you've managed to come up with such a one, though.
Answer: Let's keep it nice and simple; and say

"My older younger brother."

Everyone will get the meaning of that phrasing.
Answer: To say "my older brother" puts you at the centre of the group to which you are applying the comparative adjective, and therefore includes you in the comparison (and therefore implies older than you).
To say "the older of my brothers" puts the brothers at the centre of the group, and applies the comparison to the brothers only. There is no implied relationship with you.
This ties in nicely with @CopperKettle's comments.
My main point of comment, though, relates to your

He has finished a degree at Uni...

I seriously hope this doesn't factor into your judgement about his credibility to be authoritative in this matter. If so, I've done a PhD, and I agree with you.
Answer: No, he cannot call a younger brother his OLDER brother. When a male refers to the brother right under him, he can use the phrase "MY OLDEST BROTHER". Because he is not his own brother, he's one of the brothers, but not his own brother.


Are EC gears possible to machine in metal with conventional methods?

Question: See https://www.ec-gearing.com/. I'm wondering if it's possible to CNC machine / mill this at all with very high accuracy.
Comment: Why wouldn't it be? As long as you have the right CNC machine(s). And conventional means different things to different people.
Answer: I have seen videos, and one instance in person, of a multi-axis CNC machining center performing quite complex milling/machining in which the work piece is rotated simultaneously with the tool head. These machining centers can produce work with tolerance of one tenth of one thousandth of an inch.
The difficult part of such a construct is creating the g-code necessary to produce the desired part.
As your title asks, can this be done with conventional methods is more dependent on what you consider conventional. A multi-axis machining center is conventional in that it does not involve additive manufacturing, laser cutting or other somewhat esoteric processes.
There was a successful Kickstarter campaign known as Pocket CNC, a rather compact 5-axis milling machine. I'm not versed in the accuracy/precision of the device, but it also falls back on the ability to generate g-code to make the required parts. I've noted just now that the mill is limited to materials up to the hardness of aluminum.

Image from Kickstarter campaign.
Comment: Damn. That's tiny
Answer: Piece of cake with single point CNC. When I retired years ago very complex threads were being cut on oilfields tubulars. Look up the Hydril wedge thread series of connections: not possible to describe in a reasonable amount of words. These threads may be cut on high strength steel ( 140,000 psi tensile). For a gear they would likely be surface carburized after machining.


Converting HTML5 to XHTML

Question: What do I need to ponder if I want to convert Twenty Eleven theme to XHTML? Is it just the matter of replacing the HTML5 for divs?
Answer: Probably the easiest way to do it is to set the doctype, etc and then use the w3c xhtml validator and just go through one by one and pick off the errors...but that will take A LOT of time, I strongly recommend you leave it as is.
Comment: Since the style is ruled by CSS, if you convert HTML5 to XHTML, the output should be the same, right?
Comment: Yes and no, if you have an `` element and you convert it to a ``, the css will still read `aside {blah}`, and you'll need to apply a class to the div to be able to target it like that. The whole idea of HTML5 is that it adds additional elements, etc to make your HTML read more semantically

Converting HTML5 to XHTML


Sampling frequency range of an discrete signal

Question: Is it possible to detect each and every frequency above the nyquist frequency? Or this can be also discrete Thank you.
Answer: In a simple word no. You can detect the presence of frequencies above the nyquist frequency but you can't categorically "know" what frequency they are. See this: -

This informs you that a sinewave at 0.6 x sampling frequency (or 1.2 x nyquist) can be appear as coming from frequencies of 0.4 Fs, 1.4 Fs or 1.6 Fs.
It's impossible to know which one is correct. Note also this can be extended to frequencies centred around 2.5, 3.5, 4.5 etc of Fs.
Also,exactly at Fs (or integer multiples of Fs) any signal present at those frequencies will be "detected" as zero or a DC level (phase angle dependent).
However it's not all bad news because even though you cannot "know" the frequency you can demodulate any movement on that "out-of-band-signal" and recover a modulating waveform intact. This is useful for software defined radios. It's called "under-sampling".
Comment: I couldnt question it properly. I said that is there any discrete behavior persists in detecting sampling frequency. As an example, if we can detect any signal above with minimum 6 Hz, then over that there are many possibilities. We can detect 6.1 Hz, 6.01 Hz, 6.001 Hz. My question actually whether there is any limit of the rational values. I got my answer, it depends on how much precision can a digital device do. Thank you anyway.
Comment: I don't understand what you are saying.
Comment: I have no idea what you are trying to do. What is a "rational frequency". Maybe we just leave this as (for now) an unanswered question.


How do I increase the voltage limit by connecting same capacitors?

Question: Assume a capacitor's voltage limit be v, and the target voltage limit be V.
What is the way of connecting the capacitors to reach the V?
Answer: ON DC
If you have two 100V rated capacitors in series, you cannot assume that the combination of the two will be 200V. Slightly different leakage currents will mean one cap has more voltage across it than the other.
This can be mitigated by adding resistors across each capacitor that have values lower than the effective leakage resistance of the capacitors. If the cap has a leakage R of (say) 10M\$\Omega\$, go for 1M\$\Omega\$ resistors. Any variation will be reduced by about 10:1 BUT, I'd suggest you wouldn't get better than 1.9 x original voltage rating.
ON AC
This is determined by the capacitor values so if one capacitor is smaller than the other, it will receive more AC volts across it.
Answer: Connecting two identical capacitors in series, each with voltage threshold v and capacitance c, will result into a combined capacitance of 1/2 c and voltage threshold of 2 v.
However, it is far better to get a single capacitor that meets the higher voltage threshold on its own as combining capacitors in series will also lead to a higher Effective Series Resistance (ESR). In the scenario above, you will double the ESR. High ESR can cause unwanted or catastrophic effects on circuits not designed to handle it.
See more here: What are some reasons to connect capacitors in series? and here Can you make a non-polar electrolytic capacitor out of two regular electrolytic capacitors?
Comment: For real life capacitors (not identical ones) You will never get a "voltage threshold of 2" for the reasons outlined in my answer. Despite the OP accepting your answer there is a risk someone may assume it applies to real components so I'm making this comment. In that part of your answer where you have attempted to answer the op, the lack of reality when using real caps means I have to downvote, sorry.
Answer: The hypothetical case of ideal capacitors which are perfectly identical in leakage current and voltage ratings, is well described in existing answers. In practice, things get a bit more complicated.
If the load in the application has a high duty cycle, active balancing of capacitors connected in series is required, to protect the capacitors from an early demise. This can be done with discrete components, but there are also purpose-built, highly integrated capacitor balancing ICs available.
While general-purpose electrolytic capacitors are sensitive to voltages over rating, non-electrolytic capacitors such as mica or ceramic ones are less so. Most sensitive are electric double layer capacitors (supercapacitors), which are also typically rated for fairly low voltages, making the problem more relevant in moderate voltage circuit designs.
Thus capacitor active balancing ICs are most often used for supercapacitor banks, such as  for car audio buffer capacitors. An example is the Texas Instruments BQ33100 Super Capacitor Manager, that can manage from 2 to 5 or even 9 supercapacitors or conventional capacitors in series.
Of course, for conventional electrolytic capacitors, it is simply more cost effective to use a capacitor with a higher voltage rating, or a bunch of high voltage lower value capacitors in parallel.

At a simpler level, for low duty cycle / low load applications, a passive balancing approach can be adopted. This Maxwell Technologies appnote describes the approach, consisting of a resistor in parallel with each capacitor, in a ladder arrangement. The resistors are sized to "dominate the total cell leakage current" by typically 10 times the maximum leakage current of the target capacitors.
From an answer to another question, here is such a passive balancing arrangement:
Answer: Capacitors connected in series add their voltage tolerances. (This is true if their capacitance values are identical.)
Note that the equivalent capacitance value of capacitors in series is smaller than any individual value according to the formula:
$$\frac{1}{C_{eq}} = \frac{1}{C_1} + \frac{1}{C_2} + \frac{1}{C_3} \dotsm$$


pam_tacplus.so and sshd: skip user validation?

Question: I'm trying to implement tacacs authentication on a freebsd box as a client.  The box is actually a network appliance that SHOULD have this config built into its cli/ui but doesn't.  Since it's built on freebsd, it has the pam_tacplus.so library built in.
My problem is that I wish to authenticate to our tacacs server, but I don't wish to configure local accounts on the appliance.  Here's the pam.conf file:
su      auth        sufficient  pam_rootok.so
su      auth        sufficient  pam_unix.so

login   auth            required        pam_unix.so
login   account         required        pam_unix.so
login   password        required        pam_permit.so
login   session         required        pam_permit.so

ftpd    auth            required        pam_unix.so

sshd    auth            sufficient      pam_tacplus.so  template_user=testuser
sshd    auth            required        pam_unix.so
sshd    account         required        pam_unix.so
sshd    password        required        pam_permit.so
sshd    session         required        pam_permit.so

telnetd auth            required        pam_unix.so

passwd  password        required        pam_unix.so     no_warn try_first_pass nullok

other   auth            required        pam_unix.so

The tacacs server's ip address is stored in /etc/tacplus.conf and since I see failures in the tacacs server's log, I believe communication is successful.  Additionally, I can establish TCP session to server on port 49.
When I try to log in via ssh as jimbob, here's what I see in the /var/log/auth.log:
<auth.info> Lab-2 sshd[4952]: Invalid user jimbob from 10.0.0.1
<auth.info> Lab-2 sshd[4952]: input_userauth_request: invalid user jimbob
<auth.info> Lab-2 sshd[4952]: Failed none for invalid user jimbob from 10.0.0.1 port 52069 ssh2
<auth.info> Lab-2 sshd[4952]: Failed publickey for invalid user jimbob from 10.0.0.1 port 52069 ssh2
<auth.info> Lab-2 sshd[4952]: Postponed keyboard-interactive for invalid user jimbob from 10.0.0.1 port 52069 ssh2
<auth.info> Lab-2 sshd[4952]: Postponed keyboard-interactive/pam for invalid user jimbob from 10.0.0.1 port 52069 ssh2
<auth.err> Lab-2 sshd[4953]: error: ssh_msg_send: write

After searching around, this seems to apply.  This, however, talks about NSS, which is controlled by nsswitch.conf, which doesn't exist on this system.  There doesn't appear to be a tacacs plugin for NSS; I'm not sure that it would matter, in my case, if there were.
So, is there a way to skip checking the local passwd file for a user before getting to the pam_tacplus.so library?  I'm guessing that if there were, the template_user= option would kick in and try to use 'testuser,' which DOES exist as a localuser:
pw user show testuser
testuser:*:1003:1003::0:0:User &:/home/testuser:/usr/bin/bash

Answer: You can achieve this easily, as I have.
You are right, you should use the nsswitch.conf file. However you will have to install a third party program , libnss-ato, which stands for All-To-One. It will validate non-local users against a a configured tacacs+ server, then behave exactly as you wished.
You can get that package and its details here:
https://github.com/donapieppo/libnss-ato
Comment: I had the same problem and able to fix with this


Reaction quotient and Gibbs free energy at the start of a reaction

Question:
According to the equation 33 above, shouldn't be all the reactions be spontaneous initially? Because the reaction quotient Q, is zero at the start of the reaction and logarithm of Q makes it a very large negative value and ultimately we'll have ∆G to be a large, negative value which makes the reaction spontaneous?
Comment: Yes, basically this is stated in an answer to this post: https://chemistry.stackexchange.com/questions/115541/if-change-in-free-energy-g-is-positive-how-do-those-reactions-still-occur/115544#115544
Comment: Have you taken the image from which textbook?
Answer: Your interpretation of the equation is correct. $\Delta G^o$ gives you thermodynamic favorability of a reaction under standard conditions (Q=1) and even reactions with positive values of $\Delta G^o$ (unfavored under standard conditions) can be driven to proceed if the concentrations of the reactants and products are made extreme enough.
The best way to think about the process is via a curve of G vs reaction extent $\xi$, this is related to Q and ranges from 0 (pure reactants, Q = 0, #1 on the graph) to 1 (pure products, Q = ∞, # 2 on the graph):

https://chem.libretexts.org/Bookshelves/General_Chemistry/Book%3A_Chem1_(Lower)/15%3A_Thermodynamics_of_Chemical_Equilibria/23.4%3A_Free_Energy_and_the_Gibbs_Function
Any reaction will have an equilibrium point on this curve, corresponding to a most stable composition (# 3 on the graph). The value of the equilibrium constant (K) tells us the x coordinate of the most stable position (i.e. how much reactant vs product we have in the equilibrium mixture).
No matter what the value of K, it will always be in the range $0<K<∞$. If we start the process with pure reactants, $Q = 0$ and we are to the left of the equilibrium point. The system will shift to the right and some of the reactants will convert into products.
This is what you mean by

ultimately we'll have ∆G to be a large, negative value which makes the reaction spontaneous?

you can calculate a negative $\Delta G{_r}$ for the reaction when you have no (or infinitesimal amounts of) products.
Many texts are moving away from the term "spontaneous" for this situation, because the system may not shift to the right (reactants convert to products) if there is a kinetic barrier to prevent this, so the forward reaction may not actually be observed. The term "thermodynamically favored" is often used instead, meaning having a negative $\Delta G{_r}$ under these conditions.
You can find lots more about these concepts at the following posts:
If change in free energy (G) is positive, how do those reactions still occur?
Calculating ΔG at the extremes of reaction extent
Answer: What you write is correct about all reactions proceeding if starting with reactants only, these will decrease in concentration and products increase until equilibrium is reached. How long this takes is a matter for chemical kinetics not thermodynamics. Strictly speaking thermodynamics has nothing to say about this process as it deals only with equilibrium situations.  Think of the word 'spontaneous' in thermodynamics as not having the same meaning as the word used in general language, but describes only that $K_p > 1$ so that $\Delta G^{\mathrm{0}}<0 $.
The graph below shows $\Delta G=\Delta G^\mathrm{0} +RT\ln(Q)$ where for a reaction $\ce{A <=>B}$ at equilibrium $\displaystyle Q\equiv K_p=\frac{p_B}{p_A}$ where $p$'s are the partial pressures. The $\Delta G$  is the gradient of $G$ with extent of reaction $\xi$ which is zero when only reactants are present and is $1$ when $1$ mole of reactants have been converted to products. Thus $\Delta G$ is the slope of the curve shown in the plot in the previous answer.
An alternative way of looking at this is shown in the figure below. You can see that as $Q$ becomes smaller $\Delta G$ becomes larger and negative, and vice versa. The slope of the plot is $RT$.