Aliens voting in Federal elections

Question: I've read that a Federal law prohibits non-citizens from voting in Federal elections. I'm not a lawyer, but from reading the original Constitution and all the amendments, I don't see anything that empowers Congress to enact such a law. I would have thought that allowing resident aliens to vote would be up to the individual states. What is the Constitutional basis for this law?
Answer: TL;DNR: Madison, Hamilton, Justice Harlan & Justice Scalia agree with you. Justice Black does not.
You raise an interesting question. As you point out, the Qualifications Clause, Art I, § 2.1, (those who vote for the House of Representatives "in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature") gives states the power to establish voter qualifications. Yet 18 U.S.C. § 611, passed as part of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, (the IIRIRA) makes it illegal for most aliens to vote in federal elections. What gives?
First, the IIRIRA is purely symbolic. It literally has no effect on who can vote in the US. For almost a century, every state has prohibited aliens from voting in state elections. Under the Qualifications Clause, this means no aliens can vote in federal elections. (Before WWI, many states allowed aliens to vote.)
Second, some people argue Congress has control over voter qualifications under the "Elections Clause," Art. I, § 4.1, which gives Congress the power to regulate the "Times Places and Manners of holding elections." Like Dale M, these people read, "Manners of holding elections" to include the qualifications for voting.
This reading of the Elections Clause is inconsistent with several of the sources of constitutional authority Americans typically consult, including the text, the intent of the Founder and precedent. All of these support the "Qualifications Clause" reading of the Constitution.
1) Constitutional Text: Reading the Elections Clause as giving Congress control over voter qualifications, renders the Qualifications Clause almost completely meaningless. Yet everyone agrees the Constitution should be read so that all its parts mean something – no part should be rendered superfluous.
2) Intent of the Founders: When the Founders debated voting qualifications, they were clearly worried that politicians would manipulate the electoral rules to favor them. The Founders believed the Qualifications Clause kept both national and state politicians from stacking the electoral deck. First, by giving the power of deciding who could vote to the states, the Clause prevented national politicians from choosing their own electorate. Secondly, by requiring the states to use the same qualifications for voters in state and national elections, the Clause prevented state politicians from manipulating the rules in national elections.
As for the Electoral Clause, in Federalist 60, Hamilton was clear who controlled voter qualifications: "The qualifications of the persons who may choose or be chosen…are unalterable by the [federal] legislature…"
3) Precedent and practice: For most of our history, people acted consistently with Hamilton's statement. They tolerated a wide variation in who was allowed to vote across states. As noted above, many of those states specifically allowed aliens to vote. (And, starting in 1787 with the passage of the Northwest Ordinance, Congress passed a series of laws allowing aliens to vote in territories.) When Americans did make nationwide changes to voting qualifications, they did so by amending the Constitution.
There are only a handful of Supreme Court decisions involving federal control over voting qualifications. In 1970 the Supreme Court upheld a federal law changing the voting age to 18. The opinion of the Court, written by Justice Black, relied on the Elections Clause to say that Congress had the power to change voting requirements. None of the other Justices shared Black's views on the Elections Clause. Instead, they agreed with Justice Harlan, who said, "nothing" in the Constitution, "lends itself to the view that voting qualifications in federal elections are to be set by Congress." (These Justices used the Equal Protection Clause as the basis for federal control over voter qualifications.)
Since then, no Justice has followed Justice Black. Instead, they have followed Justice Harlan. For example, in 2013, Justice Scalia, (in an opinion joined by Breyer, Ginsburg, Kagan, Kennedy, Roberts, and Sotomayor) said, "the Elections Clause empowers Congress to regulate how federal elections are held, but not who may vote in them."
From this evidence, I'd say you were right to be puzzled about the constitutional authority for the IIRIRA. A federal law preventing aliens from voting in federal elections undermines the text of the constitution by rendering the Qualifications Clause superfluous, goes against the clear intent of the Founders, and is inconsistent with 200+ years of history and precedent. It only survives because it has no practical effect on voting in the US.
Comment: Many thanks for your remarkably thorough and lucid answer.
Comment: @bof You are welcome. Honestly, I should thank you. My answer was inspired by my (mis)reading of your comment on Dale's post. I was so sure you were wrong that I looked at the Constitution to see exactly how you'd screwed up. Instead, I saw that you were right, and I was wrong. So my answer is just a commentary on your comment, which is spot on.
Answer: You asked whether 18 U.S.C. § 611 prohibits aliens from voting for state legislators.
As usual, the answer is: It depends.
In this case, it depends on whether there are candidates for federal office on the ballot. 18 U.S.C. § 611 prohibits aliens from voting in elections that include candidates for a federal office. So if there is no federal candidate on the ballot, this law does not apply.
Even if there is a federal candidate on the ballot, aliens might still be able to vote on state or local candidates or issues.  Aliens who are allowed to vote by state or local law, can vote for these candidates or issues in "mixed" elections as long as voting for them:

"is conducted independently of voting for a candidate for such Federal offices, in such a manner that an alien has the opportunity to vote for such other purpose, but not an opportunity to vote for a candidate for any one or more of such Federal offices."

In English: Aliens can vote as long as they get a ballot that cannot be used to vote for federal candidates.
Of course, this all assumes state law allows aliens to vote. Since no states currently allow aliens to vote, this law has no effect.
You can read the statute, which is atypically short, here:
https://www.law.cornell.edu/uscode/text/18/611
Comment: Thanks again. My question about voting for state legislators was meant as a *reductio ad absurdum*. Seeing as the act is blatantly unconstitutional, I'd prefer to say that it *pretends* or *purports* to prohibit this or that.
Comment: A vaguely related question occurred to me. Since the relevant amendments apply only to citizens ("The right of citizens of the United States to vote shall not be denied or abridged . . ."), there is apparently nothing to prevent a state, which lets aliens vote, from allowing only those aliens to vote who are white, male, and over 25. But that would be another question, and I'm not going to ask it because it's too silly.
Comment: And thanks for the link. As a non-lawyer, being not at all in the habit of reading statutory language, I had somehow imagined that an Act of Congress would start with a preamble explaining how it is authorized by the Constitution. I guess I dreamed that up.
Comment: @bof "there is nothing to prevent a state..from allowing only those aliens to vote who are white, male, and over 25." Well there is the Equal Protection Clause. In Graham v. Richardson, 403 U.S. 365 (1971), the Court held that denying legal aliens access to welfare benefits violated EP.
Comment: @bot 18 U.S.C. § 611 was part of the IIRIRA, which was part of Public Law 104-208, an Act "Making omnibus consolidated appropriations for the fiscal year ending September 30, 1997, *and for other purposes*." PL 104-208 is 749 pages long. In addition to the IIRIRA, it includes funding for DOD and the Capitol Police, amendments to the Small Business Act and authorization for an NAS "study of the tagging of smokeless and black powder by any viable technology for purposes of detection and identification..." https://www.govinfo.gov/content/pkg/PLAW-104publ208/pdf/PLAW-104publ208.pdf
Answer: Clause 1

The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing [sic] Senators.

It'd be this one.
Comment: I suppose you're a lawyer, so I'll have to take your word for it that "Times, Places and Manner" includes voting qualifications. But what about the clause that says "The House of Representatives shall be composed of Members chosen every second Year by the People of the several States, and **the Electors in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature"?**  Does the Act of Congress I was asking about also prohibit the States from letting resident aliens vote for State Legislators?

Aliens voting in Federal elections


sslstrip vs. privoxy redirect rule on clients

Question: I watched this video: http://www.securitytube.net/video/193 Now I'm thinking about an example.

Suppose I have a privoxy proxy on my PC:

user.action file (just part of it):
{ +redirect{s@http://@https://@} }
.foo.org

then I visit http://foo.org and get redirected to https://foo.org.

The big question: Am I protected against sslstrip?
What will happen? Will the page fail to load? Will using this kind of redirection keep my browsing safe?

Thank you!
Answer: This won't work very well.  If you try it, you'll probably find that you are unable to browse most sites, because most sites don't offer their site through SSL (https:).
The right way to defend yourself: install the HTTPS Everywhere extension for Firefox.  Any time you visit a web site that is known to support https, HTTPS Everywhere will automatically redirect your browser to use the https version.  It's great!  I use it and highly recommend it.
Important caveat: You will still be vulnerable to sslstrip / Firesheep style attacks when browsing sites that don't support https.  There's not much you can do about that, except ask those sites to support https, or avoid using unencrypted wireless networks.  (Or, buy a secure encrypted VPN service to route all your communications through: but that is inconvenient and expensive.)
Comment: @Rook, the reason for using HTTPS Everywhere instead of privoxy is not that HTTPS Everywhere is safer.  The reason is that HTTPS Everywhere actually, you know, works and doesn't break your web browsing experience.  If you use privoxy, then as I explain in the first paragraph of my answer, it won't work very well, because many sites don't offer their site through https.  HTTPS Everywhere has put considerable effort into devising a list of sites that do offer their site through https, so it's about as good a whitelist as you're going to get.
Comment: i'm only asking sites that has been whitelisten in a redirect rule, so only the sites that support https. so if a site supports https+i write a redirect rule, then i'm fully protected?
Comment: i think using a redirect rule with privoxy will save me from an ssltrip attack, because the page just wont load on http, because the redirection, but i need a fixme for this, that's why i asked! :P
Comment: -1 HTTPS Everywhere  has the **exact same problem** as using privoxy,  it is no more or less safe.  Either way a DigiNotar style compromise will not help.
Answer: Yes, this Privoxy rule set will prevent just a plain SSLStrip attack.  But it can't prevent against all attacks. Recently a certificate authority by the name of DigiNotar was compromised. DigiNotar knew they have been comprised but failed to notify the public leading to Mozilla removing them as a trusted CA.  This hacker has claimed to compromised 4 other CAs.  These forged certificates have been used in iran to MITM Gmail and Facebook.
The author of SSLStrip, Moxie Marlenspike, was able to use it in conjunction with other attacks,  such as null byte poisoning, to produce forged certificates.  This attack was covered in More Tricks For Defeating SSL.
In both of these cases HTTPS Everywhere and Privoxy fall to the same problems.  The certificate appears to be absolutely valid from the browser's perspective.
In 2011, Moxie Marlenspike gave the talk The Future of Authenticity. In this talk he details why Convergence can solve these problems. If you are in Iran or China and you are worried about your state sponsored ISP performing MITM attacks on you with forged certificates then you can use Convergence to detect this attack. However, in order to access the website safely you have to use The Tor Project.
Answer: The other 2 answers are excellent, but I thought I would throw this log onto the fire, too:
If you are at work (or anywhere where you are using a computer that isn't 100% under your control), then you shouldn't assume any safety at all, even when using SSL.
I know many large organizations that distribute their own root certificates and have an SSL intercept device on their network. These devices can MITM your SSL traffic by generating a fake certificate on the fly and signing it with their own root. These organizations install the root cert on all of their equipment, so if you are using a company laptop, for example, it already trusts this root.
If you are particularly cynical, you may believe that large CAs and government-sponsored CAs (such as China's information ministry) are offering fake certificates to law enforcement, intelligence, and/or military for exactly this purpose.
The only way to avoid this type of SSL sniffing is to be picky about which CAs you trust (I have removed many CAs on my personal laptop) and to use a certificate tracking plugin such as Certificate Patrol. Certificate Patrol will keep track of certificates you've seen in the past (a kind of first trust policy) and will notify you if a certificate unexpectedly changes.
Comment: I want to clarify when you are at risk from the kind of attack mentioned here.  You are at risk if you are using a work machine, or a machine that has work software on it, or if you click through SSL warning messages.  These SSL intercept devices all require the client-side machine to be configured specially to add their root cert to the cert store.  If your client machine hasn't been configured that way, you'll get SSL warning messages -- because the SSL intercept devices all involve running a MITM attack, which is exactly what SSL is designed to detect.
Comment: the Zorp Proxy can do this - generate own cert/replace with the original one.


12.04 on Mac Mini 4,1?

Question: Is Ubuntu 12.04 usable on Mac Mini 4,1 machines? The Ubuntu Mactel support pages seems to be rather out of date (they list 10.04 as the latest supported, but 11.10 runs just fine).
Answer: I've got 32 bit Ubuntu 12.04 running on a Mini in dual boot config.  The mini is from mid 2011 or so.  Mountain Lion is on the Mac side.  I use Ubuntu to serve regions on OSGrid. I actually installed the 32 bit version by mistake and intend to upgrade it to the 64 bit version real soon now.
Answer: It is usable on the version before. So I think it should work.
I have tried 10.04 11.10 and 12.04 on a Mac mini 3.
Comment: Any notes / useful resources, or was the entire thing without a hitch?
Answer: I have been using it as a media centre for a while now. I could never get the Apple Trackpad or the Apple wireless keyboard working reliably. I gave up and used a Microsoft Wireless mouse and USB Keyboard. The battery on the Trackpad last like a few days and I resorted to removing the battery to maintain the charge. But as I mentioned the Microsoft Wireless Mouse works fine and has so for 3 months and still running.
The Apple wireless keyboard was iffy to activate out of resume mode so I stuck with a USB keyboard which is black and matches my Home Entertainment Centre so its near invisible.
It is very quiet so its great for watching youtube and my other media on external drives.
It's also acting as a Minecraft server and web server with no issues. It's a great little server and media centre and highly recommend it. The native OSX is just to clumsy for my needs so I'm not even dual booting.

12.04 on Mac Mini 4,1?


Keeping a US phone number

Question: I'll be abroad for a few years and I want to keep my mobile number till I come back. What would be the least expensive way to do this?
Answer: You can also port your number to Google Voice for a one time fee of US$20. This will be signficantly cheaper than most other options, and you have the ability to port your number out of Google Voice for free. (If you brought your number into Google Voice, Google waives their US$3 fee.)
The benefit to this is that you can continue to receive text messages that deliver to your Google (Gmail/Google Hangouts) account on that number while you are gone.
Comment: Thank you very much! Sounds like a very sweet deal. I wonder about the timing of transition, though... I want to use my phone till the last minute here, or maybe till I get a new sim over there. Hope Google is willing to handle a request made from abroad.
Comment: It shouldn't be a problem. The only potential problem is your local carrier. Also, you could start early and just have Google Voice forward your calls to your "new" number on your existing phone.
Comment: Google's website says that Google Voice is only for the US. I assume that this means it can only be used in the US. Unless it means only US based customers can initially join with a US phone number, but can live in another country afterwards.
Comment: I was a US-based customer. I am using it in South Korea right now. (Google, please don't cancel it.)
Answer: Verizon, and probably all the major carriers, offer prepaid sim only deals where $100 will keep your number for a year. At $8.50 or so a month it is probably cheaper any other plan you will find. As you only need to keep a few pennys worth of credit to keep the number, you might be able to resell, at a loss, some of the time by letting friends make calls or surf the web from your account. I am not aware of anyway to suspend your account for long periods of time.
Comment: Thanks. I guess I can renew the one year deal every summer...
Answer: I've got two extra lines, for visiting friends & family. They're used every few months. I keep them on T-Mobile Pay-As-You-Go, which is currently $3/month.
Answer: You can port your number to Twilio, then pay $1/month to keep it active there. You can also get crafty with forwarding and voicemail and such.
Comment: it is more technical @lswank - but the original question didn't say anything needed to be *done* with the number. Doing simple things (like "say a message about how I'm out of the USA and how to get ahold of me") are pretty easy. In fact, there's a section for nonprogrammers on their ["quickstart" page](https://www.twilio.com/docs/quickstart).
Comment: That certainly works, although it's a much more technical option. Is there an easy, out-of-box solution for that?
Answer: You can use an unlocked VoIP SIP service like Anveo.com, where the cost of keeping a US/Canada phone number on the Personal Unlimited rate plan is 2 USD per month, which includes an unlimited number of incoming voice calls for personal use, plus they even support SMS (most unlocked VoIP providers don't).  The normal cost to port a number is 15 USD, but they often run a porting promotion in that they'll do the porting for free if you prepay Personal Unlimited for 12 months, e.g. it'll cost you a total 24 USD for first year, then 2 USD per month thereafter, to have an unlimited use of your phone number for incoming phone calls anywhere in the world for as long as you please.  There are also other alternative SIP providers, but most of them don't support SMS.
You can use the service with any software or hardware that supports SIP.  E.g., you can buy one of the many hardware phones like Cisco SPA303, or you can you an unlocked softphone on your mobile phone like Acrobits Softphone (or, if you're using Android, it may even have integrated SIP support out of the box directly within the Phone app).

Keeping a US phone number


compatibility of lens hoods and lens filters with step up ring

Question: I have never owned a lens hood, but I have owned a lens filter for my kit lens. I now have a new lens, a Canon 50mm F/1.8 STM, and I want to buy a lens hood. I read that lens hoods are made specifically for the lens, not necessarily the lens size. Will putting on a regular sized lens filter make it incompatible with a lens hood? I also own 67mm lens filters for my kit lens and would like to use a step up ring to make them compatible with my 49mm diameter lens. Will a lens hood still fit with a step up ring in the way? If not, can I buy a lens hood that is compatible with my kit lens so it will fit on the step up ring?
Comment: Be aware of potential vignetting. Some lenses are so close to their vignetting limits that eg two filters stacked or an (usually nasty) aftermarket hood that screws onto the filter thread will cause vignetting at the corners. This may be subtle enough to be unnoticed until specifically looked for but still enough to lower quality markedly.
Answer: I've never seen a conventional hood that will allow use of step-up rings. About the closest you might come to that for most lenses would be a filter system with a holder, such as the Cokin P-series system, that uses various step up rings for each of your lenses and offers attachments to the filter holder that shade the front of the lens from off-axis light. They are sometimes referred to as matte boxes.

In the case of the EF 50mm f/1.8 STM, though, the specific design might let you get by with something such as you envision.
The Canon hood specified for the lens is the ES-68 that attaches in a bayonet style on the outside barrel of the lens. The filter threads for the lens are on the inner barrel that extends and retracts with focusing movements. There is a larger than typical difference between the diameters of the filter threads and the inside of the lens hood. You may be able to squeeze a step up ring in there and attach a larger filter, but I doubt you'll be able to go from 49mm to 67mm because the difference in the thread and outer barrel radiuses appears to be less than 9mm. You could measure your lens to be sure, though.
Another option might be to use an aftermarket screw in hood that attaches to the lens' filter threads. You would then attach a step up ring and filter to the the threads on the front end of the spin-on hood if the hood has them. The front threads are probably in the 52-55mm range but might be large. Just measure before you get a step up ring.
Answer: A 49mm filter will work just fine when using  the ES-68 hood. So willl a 58mm filter.
I use my 50mm STM with an ES-68 hood and always keep a 49-58mm step up ring attached.  I prefer the larger 58mm lens cap and occasionally use a 58mm CPL as well.
I tried adding a 58-67mm step up ring but found that the ES-68 hood will not fit over the step up ring.


Mold in S-Shaped Airlock

Question: I'm new to homebrewing, and I've recently encountered a problem with an s-shaped airlock. I clean it out with water after use, but it takes forever to dry on its own. This time, it's started growing mold inside after washing it out. Is there some way to dry out the airlock to prevent this sort of mold growth? I imagine if I cleaned it out with vodka or something similar, it would prevent such growth, but I'd prefer to clean with water, because it's essentially free.
Comment: Chuck it and buy a new one. Why risk it?
Comment: Cheap vodka is *almost* essentially free. And so is a bleach solution.
Answer: Couple of things if you plan to keep using these air locks it's fine to rinse everything with water but run sanitizer through it. I keep sanitizer on hand in a spray bottle for all sorts of things. Try spraying a generous amount in the air lock after rincing gunk out of them. It might not be "free" but throwing out a bad batch because of an infestation is way more expensive.
If however you can see any gunk in there you need to get it out of the airlock before storing and you'll need to use a cleaner. I like oxyclean because it's cheap and works well. Fill a small container and emerge the lock in there.
A second suggestion would be to switch to a blow off tube or 3 piece airlock as IMO they are easier to clean as their are no s traps for crud to be trapped in. I prefer the s shaped locks for secondaries only.
Answer: You can get very close to free with using a little diluted dollar store bleach. When you rinse it, rinse it well, then take a blow dryer and run it through the airlock for a few minutes and it will be dry.
Answer: It's ill-advised to take any shortcuts with cleaning or sanitation, even with an airlock.  Clean it with PBW (powdered brewery wash) or OxiClean solutions prepared according to the directions on either package; alternatively, use un-scented chlorine bleach.  Whatever is used, soak for a couple hours, and rinse thoroughly with clean water.

Mold in S-Shaped Airlock


Lower lat/ribcage pain while Deadlifting

Question: For the last year or so I've been taking the deadlift seriously. Every time I near my max, we'll say my 3-rep max, I feel a what can best be described as a pressure / pain on my lower rib cage. It feels like it could be deep muscle, as the pain fades quickly (1 or 2 seconds) after I set the weight down. Anyone else experience this? Anyone know the cause/how to remedy it? Thanks.
Answer: This may be an indication of an imbalance in the supporting muscles. Namely, the core and posterior chain. You might consider some accessory work on your core and lower back to bring them up to speed with your DLs.
Answer: Deadlifting is a great exercise, but without understanding what else you are doing I'm going to be working off of assumptions.

I'm assuming you are pulling heavy (90+%) often, with 1-3 reps at a time.
I'm assuming that your assistance work is probably lacking.

However, before I get into that, have you ever had chicken pox?  Last year, it felt like I strained my back, only to find out it was shingles.  A combination of getting sick and training hard for competition depressed my immune system enough that I had a flare-up of shingles.  Before that after heavy 90+% pulls the same area felt like it was on the verge of a strain.  Anyone who has had chicken pox potentially has the shingles virus waiting for your immune system to get depressed enough to let it cause pain.
If you are not dealing with shingles, and have never had the chicken pox, then you may be dealing with a minor lat strain.  If you suspect this is the case, then my recommendation is:

Lower the intensity on deadlifts for a while.
Incorporate high rep low weight assistance work to help you lats heal.

Low-weight, high rep work helps get blood flowing through the affected area which speeds recovery.  While pull ups are great at working the lats, they will likely be too heavy to get the work you want done.  Potential lat exercises can be:

Straight arm lat pull downs
Leverage ISO Row

You can use any of several alternatives, but you want to work with a weight you can do 3x15 (3 sets of 15 reps each).  Feel free to drop 5-10lbs each set if necessary to keep the rep work going.  If one variation of exercise causes the pain or makes it get worse, choose a different alternative or lower the weight.
Do the lat work every time you are in the gym and try to increase the weight no more often than weekly.  After 2 weeks of this, you can start to slowly increase the weight on the deadlifts--staying below the weights that cause pain.  By the end of 6 weeks you can taper the lat work down to only being done after deadlifts.  By that time you will have built up the work capacity of your lats and repaired the strain.
I recommend that even after the 6 week rehab work is done, you don't just jump right in to 90+% work on the deadlift again.  Build up from 80-90% again.


Non-western music with tonic/predominant/dominant (or something like it)

Question: Are there any examples of non-Western music which have the equivalent of predominant and dominant passages as well as tonic passages, or even just the notion of dominant vs tonic?  If not, are there any close analogies?  To be specific, are there other cultures where there are ways of grouping scale degrees or classifying chords with a much smaller number of labels)?  Are there other cultures which have particular scale degrees associated with strong tendencies towards another scale degree? I have heard many times that Western music is the only source of functional harmony, but since "functional" is so ill-defined I didn't know if that actually means no concept of dominant-tonic relationship.
Answer: I would assume that the concept of scale degrees is present in all cultures. Notes sound good together when they have higher harmonics in common (e.g. the third harmonic of C coincides with the second harmonic of G) -- a concept universal to all humans.
"Harmony" however is the occurrence of these notes at the same time, as opposed to in succession, which is the case in some other melody-based music cultures. Western music is harmony-heavy in this sense.
An example from Indian Classical music : most Ragas (scales of 5-7 notes on which the entire piece is based) have "Vaadi" (most important/frequent) and "Samvaadi" (second-most important/frequent) notes. They must have a dominant-tonic relationship with each other.
Harmonic relationships also play a role for determining which microtones are supposed to be present in the Raga
Answer: The meaning of "functional harmony" is pretty clear..
https://en.wikipedia.org/wiki/Function_(music)
...but that particular label should be distinguished from a general use of the word "function."
Sure, other musical cultures will have tonal systems, and you could talk about how elements function, but it won't be "function" in the Riemann sense.
No one should misconstrue that to mean one musical culture is superior to another.


Is commutation relation an equivalence relation?

Question: I'm now learning quantum mechanics with Liboff. In the book it deals with "a compete set of mutually compatible observables" in order to make a state maximally informative. How can one find such set? It seems very hard unless commutation relation is an equivalence relation. Is commutation relation an equivalence relation? That is, if $A, B, C$ are Hermitian operators, then does $AB=BA, BC=CB$ imply $AC=CA$?
Answer: Commuting is not an equivalence relation. All components of angular momentum commute with $J^2$ but they don't commute with each other.
How to find a complete set of mutually commuting observables is a difficult problem and I don't think you can give an algorithmic answer. It depends very much on  the specific problem. An observable that commutes with the Hamiltonian is conserved, this can be a good starting point. For example, angular momentum
is conserved when the Hamiltonian is rotationally symmetric.
Answer: No, it does not! Let me give you a counterexample:
Consider the Hermitian operators $\mathsf{1}$ (identity operator), $p$ (momentum) and $x$ (position) in 1D.
Now, the trivial commutation relations $[\mathsf{1},x]=0$ and $[\mathsf{1},p]=0$ do not imply $[x,p]=0$ as the correct relation is $[x,p]=\mathrm i\hbar\neq 0$.
Answer: As everyone points out commutation is not a shorthand for equivalence, as, given your relations, the Jacobi identity, [A,[B,C]]+[C,[A,B]]+[B,[C,A]]=0 dictates that when the first two terms vanish, the third must too, so that B must commute with [C,A], non vanishing in general, as remarked repeatedly.
Lie algebra commutators do, nevertheless, parameterize conjugacy, that is
$~A^{-1} B A - B= A^{-1} [ B,A] $, so an observable commuting with everything collapses to its very own conjugacy class.
Answer: Commutation does become transitive, and thus an equivalence relation (reflexive and symmetric are trivial), when you impose an extra condition: nondegeneracy.
If $A$, $B$, $C$ are Hermitian operators, and each of them has only unique eigenvalues, then $AB\! =\! BA\, \cap\, BC\! =\! CB$ implies $AC = CA$.
Proof: for a nondegenerate operator, the eigenbasis is well-defined, so if $A$ and $B$ share an eigenbasis $E^{AB} = \{|\Psi^{AB}_i\rangle\}$ (as commutating operators do), and $B$ and $C$ share $E^{BC} = \{|\Psi^{BC}_j\rangle\}$, then $E^{AB} = E^{BC}$, and it is a shared eigenbasis of $A$ and $C$. Therefore, $A$ and $C$ commute.

Just to avoid confusion: Of course, that does not mean a system of degenerate operators never commutes; for instance, consider projectors onto 3 orthogonal states $|\Phi_A\rangle$, $|\Phi_B\rangle$, $|\Phi_C\rangle$, i.e.
$$
A |\psi\rangle = |\Phi_A\rangle \langle\Phi_A| \psi \rangle
$$
etc.. Because the states are orthogonal, $AB = BA = AC = CA = BC = CB = 0$, so the operators trivially commute though they all have the degenerate eigenvalue 0.


Can you wear a robe over armor?

Question: More specifically: Can you wear a robe of eyes over plate armor?
Does it say so in the rules? I thought you can if the other clothing does not provide any AC.
Comment: Hello, just so you know, it's generally considered good manners to wait about a day before you accept an answer. This helps ensure that all users have gotten a chance to contribute with their answers and vote on the existing ones, regardless of their timezone. When you accept an answer you discourage users from contributing potentially better answers, so we advise you to wait at least a day before you click the check mark.
Answer: Yes*.
While none of the rulebooks come out and explicitly say you are allowed to wear robes over your armor (although it may be more realistic to wear your armor over your robes from a practical standpoint), there is circumstantial evidence to support it.

In the PHB, the default starting equipment for the Cleric includes both armor (your choice of Chain Mail, Scale Mail, or Leather Armor) and the possibility of clothing (the Priest's pack comes with vestments, and vestments typically include a special kind of robes called a cassock). It would not make sense for a Cleric to be unable to wear his vestments and his armor simultaneously, especially if the Cleric in question takes the particularly active role among his flock that an adventuring Cleric like a PC probably would.
As you yourself mentioned, non-magical robes in and of themselves do not provide any protection above and beyond armor, and do not conflict with armor's changes to AC. Even if robes did affect your AC (such as via a magical enchantment), the PHB clearly states that if you have more than one thing which changes the way you calculate your AC, you must choose which one applies.
As a consequence of #2 above, the only scenario in which I can imagine there might be potential for abuse is if you are trying to wear magically enchanted robes along with your armor. However, the DMG considers armor to be "Armor" and robes (along with other clothing items) to be "Wondrous Items." No reasonable person would raise the question of whether or not you could, just as examples, wear Gauntlets of Ogre Power with armor, Boots of Elvenkind with armor, or a Cloak of Protection with armor.
Expanding on #3, the DMG further has this to say:

Multiple Items of the Same Kind
Use common sense to determine whether more than one kind of a given magic item can be worn. A character can't normally wear more than one pair of footwear, one pair of gloves or gauntlets, one pair of bracers, one suit of armor, one item of headwear, and one cloak. You can make exceptions; a character might be able to wear a circlet under a helmet, for example, or be able to layer two cloaks.

So, even if you don't buy the argument that armor and robes are not the same kind of item (even though they clearly aren't, despite covering the body in largely a similar fashion), the rules provide for the possibility that they can still be combined if your DM chooses to allow it.
Olorin's answer provides further evidence that this is a valid approach to your particular situation, and references a statement of opinion given by one of 5th Edition's lead designers: Mike Mearls. It is important to note, however, that the official arbiter of the rules-as-written is Jeremy Crawford. While the words of Mearls carry significant weight, they are still merely his personal opinion on how the game works at his table.
*The Standard Caveat: D&D 5th edition empowers the DM in ways that 3rd, 3.5, and 4th did not. While rule zero has always applied, 5th Edition chooses not to explicitly codify many things. If your DM says you can't, you can't.
Comment: In general I agree with this answer, but not with "It would not make sense for a Cleric to be unable to wear his vestments and his armor simultaneously". Vestments are normally for formal ceremonies. A modern analogy would be that a marine may have both a dress uniform and body armour, but won't typically wear them together.
Comment: @tardigrade Perhaps so, but it's nevertheless normal to wear non-armour clothing under armour. Without it, the armour chafes like you wouldn't believe.
Comment: Ah, now *that* I would certainly accept as a logical argument for it being implied that you can wear both :)
Comment: @tardigrade Wearing robes under armour for anti-chafing would make even less sense from a real-life point of view - there are garments especially designed for that that also function as protection.
Comment: @Olorin less sense than *nothing*? I'd certainly dispute that. And if there are no other clothing items listed in the starting equipment, there are no other clothes to use...
Comment: @tardigrade Less sense than not being able to wear vestments and armour simultaneously. And I did mean strictly from a real-life/realism point of view, not in-game equipment.
Answer: Yes
The rules
Armor and magical robes are different categories of items, so they can be worn freely together. While plate armor is categorized as Armor, robes are classified into the catch-all category of Wondrous items (DMG p. 140).
However, should the robes give you a different way to calculate your AC (like the Robe of the Archmagi - DMG p. 194), you have to choose which to use (the sane choice being the one that yields the highest result).

Armor Class (PHB p. 14)
Some spells and class features give you a different way to calculate your AC. If you have multiple features that give you different ways to calculate your AC, you choose which one to use.

The wisdom of the sages
Mike Mearls voiced his opinion on this matter (coincidentally, exactly regarding wearing the Robe of eyes over platemail) in a sage advice:

charles @alfabetsoupe
@mikemearls Can magic items such as Robe of Eyes be worn over armor, such as Platemail? Or does the robe occupy a sole "torso slot"?
Mike Mearls @mikemearls
@alfabetsoupe you can wear it - only limit is attunement cap
Comment: In 2e Robe of Eyes is limited to the Wizard class group .. is that no longer the case in 5e? Or can wizards now wear platemail?
Comment: @Erics you should search for a question answering that, as it has been asked before, or ask it again yourself. But the short answer is yes and yes.

Can you wear a robe over armor?


Checking for gaps in Postgres WAL files

Question: I want to write a script to check for gaps in my archived WAL files, but I can't find any documentation of the numbering scheme. It looks fairly straightforward, but I'd like to base my script off of some official documentation so that I don't miss any hidden complexity with rolling over, etc.
Answer: This is not really easy to do from the filesystem.  The file name is actually three parts (8-characters each, hex values): Timeline, Logical XLOG, Physical Segment.  In order to know what the "next" file is you really need to know what's happened to the underlying database (new xlog, new timeline, etc.).
A better solution if you're archiving transaction logs is to have your archive command also append the name of the file being archived to a list somewhere -- Postgres passes the name to your archive script so you don't have to worry about figuring it out yourself, and if all the files on that list are present you have no gaps.
(This doesn't solve the problem of being sure you have no gaps before you implemented this solution, so you should take a base backup in accordance with 24.3.2 in the Postgres manual after you implement this solution...
Answer: There's no documentation outside of the source code.  There's a walkthrough of that code that explains it as well as anything I know of, trying to solve the same problem you are.  Count the last two digits upward in hex until they reach FE, then rollover to 0 and increment the second log number field in the middle.  The notes at Understanding WAL nomenclature are helpful here too.
One of the reason it's not documented is that you can change it at compile time; in practice no one does.  The other problem is that once you active a standby system or do something else to change the timeline id, all guarantees of sequence are gone.  That's also not a problem in practice for most people.  If that happens, you'll want to check the monitoring, too, anyway.

Checking for gaps in Postgres WAL files


Why is hotfix KB973869 on x64 versions of 2003/XP not working?

Question: I've applied the new KB973869 hotfix multiple times on my x64 2003 and XP systems and Windows Update keeps saying it needs to be re-applied.  What's going on?
Answer: I think there's a bug in the hotfix's detection routine that determines whether it needs to be applied or not.  The hotfix article describes a single ocx file being updated depending on your OS and service branch.  For Server 2003, it's wdhtmled.ocx being updated to version 18.104.22.16847.
Doing a filesystem search on my root partition reveals 5 copies of that file.  2 of them are just the patched versions from the downloaded hotfix.  The other three are in
<code>%SystemRoot%\ServicePackFiles\i386
%SystemRoot%\system32\dllcache
%SystemRoot%\$hf_mig$\KB973869\SP2QFE\wow
</code>
The one in ServicePackFiles is the only one that is unpatched and I don't think it's supposed to be patched since that folder is just an expanded cached copy of SP2 that was applied to the system.
In any case, I don't think there's anything to worry about.  The only still vulnerable file isn't the one used by Windows.  I'm guessing Microsoft will release a fixed version of the patch soon enough and the nagging will go away.
Comment: Nice, patches for their patches :-)
Answer: Bug confirmed:  WSUS Blog
If you are running WSUS and find that that your server never syncs, check for failed downloads (by selecting "file status" in the updates view), and decline the associated updates.  There is a corrupted Exchange Antispam update out there.


How to hide date in elementary top bar?

Question: I just want to display the hour, because It looks more clean, this option was removed and I can't find a way to just hide the day/date from the options, even elemetary-tweaks cant do that, do you guys know where is the file that contains the code of this ?, maybe I can change it by myself
Answer: You can download the indicator source with
apt source wingpanel-indicator-datetime

I would start at the source file src/Widgets/PanelLabel.vala: it seems that removing (all occurences of) the date_label variable does the trick.
After you can build and  install the package
debuild -us -uc
sudo dpkg --install ../wingpanel-indicator-datetime*.deb

Comment: I think that you should ask a new question: how to compile a (debian) package? :)
Comment: I commented inline 54`/// this.add (date_label);`
I think will work but how I compile this? or add to the system?
Answer: clone the component:
git clone https://github.com/elementary/wingpanel-indicator-datetime.git

as of 5.1 (Hera), I followed @Egon Stetmann's lead and commented out in src/Widgets/PanelLabel.vala:
//        add (date_revealer);

per @lemonslice's suggestion, follow these instructions to compile and install changes to Elementary.
voila!  enjoy not having to stare at a date all day! :)

How to hide date in elementary top bar?


Should we allow questions about commonly used gaming terminology?

Question: For example, this question: What does the term "carebear" mean in Eve Online?, or a hypothetical question about what "gg" means. Do they fall under this site's purview?
Answer: Jeff has stated - in the context of other sites - that "there is no such thing as a stupid question". And like they say on "Who Wants To Be A Millionaire" a question's only easy if you know the answer.
Someone who is new to a game won't know the "common" terminology, especially if it's used by everyone else with little or no context. So rather than showing yourself up as a complete noob on the game you need to ask the question somewhere else.
Here would seem a good place.
Answer: Why not? These are concrete questions that are not really subjective and are very answerable - most likely they can all have a "most correct single answer".
And it's very gaming related, obviously.
Comment: All these points are good, but I want to bring attention to the last point, which I find the most important thing for asking these questions on this site - being game related. "GG" narrowly skirts about this one, as it technically is game-related. However, we'd have to be careful about ending up as a lexicon for all manner of netspeak used by people in gaming communities, regardless of whether the terms are actually related to gaming. Not saying that we will become one, but saying we should be observant.
Answer: It depends on the term being discussed. Some definitions are very clear (What is frag in FPS?) but some terms might be considered subjective.
 For example I strongly disagree with the second definition of carebear on UrbanDictionary (the one about Eve-Online)


Why Job was subjected to pain and misery despite he was a pious man?

Question: What was the rationale of subjecting Job to pain and misery though he was a pious man of G-d. Please explain with logical reasons.
Comment: A medrash says he was one of Pharoah's advisers and he held counsel with Bilaam, Job and Yitro. Bilaam suggested enslaving the Jewish people and drowning the boys in the river, Yitro tried to protest and ran out but Job just remained silent, and was punished for this.

I don't know why his sons died then as they could only die for their own sin.
Comment: רבי ינאי אומר אין בידינו לא משלות הרשעים ואף לא מיסורי הצדיקים  (Rabbi Yannai says, it is not in our hands to understand neither the peace of the wicked, nor the sufferings of the righteous.
Comment: @ephraimhelfgot But why?On what basis does the Rabbi has said that?
Answer: here's one reason from Rabeinu Bachye in Chovos Halevavos gate 4.

If one asks: Behold we see some tzadikim (very righteous people) which
do not receive their livelihood except after hard and strenuous toil,
while many transgressors are at ease, living a good, pleasant life? We
will say: The prophets and the chasidim already
investigated this matter. One of them said "[Righteous are you, O
L-rd, when I plead with You: yet let me talk with You of your
judgments:] Why does the way of the wicked prosper? why are all they
happy that deal very treacherously?" (Yirmiyahu 12:1), and another
"Why do You show me iniquity and look upon mischief; and plunder and
violence are before me; and the one who bears quarrel and strife
endures." (Chavakuk 1:3), and "for a wicked man surrounds the
righteous; therefore, justice emerges perverted." (Chavakuk 1:4), and
"Why should You be silent when a wicked man swallows up one more
righteous than he?" (Chavakuk 1:13), and another one said "Behold
these are wicked, yet they are tranquil in the world and have
increased wealth." (Tehilim 73:12), and "But for naught I cleansed my
heart and bathed my hands with cleanliness" (Tehilim 73:13), and
another said "And now we praise the bold transgressors, those who work
wickedness are built up, they tempt G-d, and they have, nevertheless,
escaped." (Malachi 3:15), and many more like this.
But the prophet refrained from giving an answer because each specific
case has its own particular reason . Therefore Moshe Rabeinu commented
on this in the torah saying (Devarim 29:28) "the hidden things belong
to G-d"..and the wise man said in connection to this "If you see the
oppression of the poor, and perverting of justice and righteousness in
a province, marvel not at the matter" (Koheles 5:7), and the verse
says: "the Rock, His deeds are perfect for all His ways are justice"
(Devarim 32:4).
WHY THE RIGHTEOUS SOMETIMES SUFFER
Nevertheless, I saw fitting to attempt to clarify this matter that
should be to some extent satisfactory . The possible reasons why a
tzadik is prevented from obtaining his livelihood without effort and
must instead exert himself for it and be tested by it is as follows.

A previous sin for which it is necessary to pay him for it, as written "the tzadik will pay in the land" (Mishlei 11:31)

In the way of exchanging, to pay him more good in Olam Haba (the afterlife), as written "to benefit you in your end" (Devarim 8:16)

3. To demonstrate his good bearing and good acceptance of suffering in the service of G-d, so that others will learn from him, as you know
from the matter of Job.

Due to the wickedness of his generation, G-d tests him with poverty, hardship, or sickness to demonstrate/contrast his piety and
service of G-d unlike them, as written "Indeed, he bore our illnesses,
and our pains he carried them" (Yeshaya 53:4).

Due to his not being sufficiently zealous in standing up for G-d, and exacting justice from men of his generation, as you know from the
story of Eli and his sons, as the verse says "And it will be that
everyone who is left in your house, will come to prostrate himself
before him for a silver piece and a morsel of bread" (Shmuel 2:36).

commentaries there on #3

Marpe Lenefesh: That he receives everything with a good countenance,
and he does not rebel in sufferings so that others will learn from him
and see him and notice him and desire to serve G-d even though they
don't have all their lusts, and even though they are in poverty,
hardship or in painful sicknesses as we find with Iyov (Job) and many
other sages, who were in suffering yet did not stop from torah and
service, and as is known of Hillel who was extremely poor, and others
who needed to labor for their livelihoods and nevertheless studied the
torah.
Pas Lechem: To show the world that the Tzadik bears the bad of this
world, with good patience and a good countenance, and despite his
suffering, he does not budge from the service of his Creator in order
to ease the bad. Unlike the wicked, that even for something he is
forced to bear, he bears it with an angry heart, and therefore he
throws off the yoke of service in order to ease his troubles.
Tov Halevanon: He bears his sufferings and is not begrudging towards
G-d and accepts them with a good countenance
Answer: You're assuming that Job was a completely pious individual. The Talmud seems to think otherwise.
As CashCow explains, The Gemara (Sotah 11a) says that he was one of Pharaoh's advisers who didn't try helping the Jews:

א"ר חייא בר אבא א"ר סימאי שלשה היו באותה עצה בלעם ואיוב ויתרו
Rabbi Ḥiyya bar Abba says that Rabbi Simai says: Three noteworthy people were consulted by Pharaoh in that counsel where Pharaoh questioned what should be done with the Jewish people. They were Balaam, and Job, and Yitro.
בלעם שיעץ נהרג איוב ששתק נידון ביסורין יתרו שברח זכו מבני בניו שישבו בלשכת הגזית שנאמר (דברי הימים א ב, נה) ומשפחות סופרים יושבי יעבץ תרעתים שמעתים סוכתים המה הקנים הבאים מחמת אבי בית רכב וכתיב (שופטים א, טז) ובני קיני חתן משה וגו'
Rabbi Ḥiyya bar Abba teaches what occurred to each of them: Balaam, who advised Pharaoh to kill all sons born to the Jewish people, was punished by being killed in the war with Midian (see Numbers 31:8). Job, who was silent and neither advised nor protested, was punished by suffering, as detailed in the eponymous book in the Bible. Yitro, who ran away as a sign of protest, merited that some of his children's children sat in the Sanhedrin in the Chamber of Hewn Stone, as it is stated: "And the families of scribes who dwelt at Jabez, Tirathites, Shimeathites, and Sucathites, these were the Kenites who descended from Hammath, the father of the house of Rechab" (I Chronicles 2:55). And it is written: "The children of the Kenite, Moses' father-in-law" (Judges 1:16). This teaches that the Kenites, descendants of Yitro, the father-in-law of Moses, dwelt at Jabez [Yabetz], referring to the place where the Jewish people go for advice [eitza], i.e., the Chamber of Hewn Stone.
Comment: @Maxood Considering that the Gemara ([Bava Basra 15a](https://www.sefaria.org/Bava_Batra.15a)) debates when (and if!) he lived, there isn't much of a first hand evidence either way. But considering that the Talmud is part of the [Oral Torah](https://en.wikipedia.org/wiki/Oral_Torah), it's as good as your going to get.
Comment: And may I know what is the authenticity of this allegation on Job? I meant to seek the original or first hand evidence.
Answer: What these commentators seem to overlook or address is what we find in the opening of Job: This good man's misery is instigated entirely from a bet, if you will, between G-d and the Accuser (Satan). Were there verses that communicated HaShem's intention to use Job as an important lesson for others that we must all bear the miseries of life with continued faith despite those miseries, or some such lesson, I could be more satisfied. Instead the book tells us that HaShem entered into this wager simply to satisfy the Accuser's accusation. HaShem's treatment of Job reminds me of a passage in Shakespeare's KING LEAR: "As flies to wanton boys are we to the gods: They kill us for their sport."
Comment: I don't see how this answers the question. It seems to just strengthen the question. Consider editing to clarify.
Comment: Welcome to Mi Yodeya David!
Comment: I think my comment does answer the question. If the question is "Why was Job subjected to pain and misery despite his being a pious man," the answer is "Because it was HaShem's pleasure to do so." More specifically HaShem had a bet to win, so he felt justified in toying with a pious man to prove his point. In my example, HaShem is the wanton boy, and we humans are the expendable flies.
Comment: The OP said "Please explain with logical reasons." - Your answer is Gcdly but not logical.
Comment: I see your point. My only answer to that request is that no logical answer exists. There is often no logic to the happenstance events that fall our way. We can make choices that sometimes result in logical outcomes. But often, as is the case with Job, we find no logical cause-and-effect outcome. Life does not always make logical sense. As my parents, and many like them, were fond of saying when I was a child and complained that something was not fair, "Life's not fair." Still, we have something inside us that craves justice. But justice suggests logic, and sometimes we get neither.


.NET Remoting server-side hanging

Question: We have a .net remoting application sitting in between web app and database. Occasionally we get strange problem. The remote call simply hangs and never returns. We used package sniffer to check the traffic. It seems to be the server side problem. If we stop the server app, a network exception will be thrown immediately. However when we debug the server code, it does not hit any code. It seems the request is blocked somewhere inside the remoting stacks. Does anyone have similar experience?
Answer: I did experience a similar issue in .Net remoting quite awhile ago, using IPC.  I do not remember all the specifics, so forgive me.  The problem that I discovered was that my client application was making a remote call to the server application which took a long time (minutes) to complete.  After hooking both the client and the server up to the debugger, and catching all thrown exceptions, I discovered that the remote call actually ended up throwing a timeout exception of sorts (my memory wants to say the internal message was COM-related) since no activity was occurring over the IPC channel for the timeout period.  Apparently when these remoting connections time out, the links on both sides are essentially dead-men-walking.  Strangely, I was only ever able to see this exception through the debugger - in release mode, my application just hung like yours, without any indication as to why.  I found the remoting Timeout settings, and simply turned off the Timeout (or made it ridiculously large, again I don't remember exactly), which fixed the problem.
Answer: It turns out to be the CMS system we are using also uses .NET Remoting and it overwrites our security settings. We turned off the security settings on our remote app and everything works okay now.

.NET Remoting server-side hanging


Worldwide Dissertation Database? or French, German, Italian ones?

Question: Is there a global/worldwide database of dissertations? If not, how can I access French, German, Italian, etc. dissertations online?
Comment: For French ones, a good starting point is http://theses.fr run by [ABES](http://en.abes.fr/Theses/Applications-dedicated-to-theses/theses.fr). Many universities also keep online repositories of submitted theses. You can find more information on http://en.abes.fr/Theses/Applications-dedicated-to-theses
Comment: Possible duplicate of [Some collection of students' theses or dissertations](http://academia.stackexchange.com/questions/19575/some-collection-of-students-theses-or-dissertations)
Answer: I am not aware of an international database, but basically all german dissertations have to be submitted to the German National Library (Deutsche Nationalbibliothek), so if they exist in physical form they can be accessed at the libraries in Frankfurt and/or Leipzig. If they only exist in electronical form, they are still registered at the library. The following link is going to give you a list of all german dissertations that are freely available online:
DNB search
The DNB also has a manual about searching for dissertations, however I could only find a german version that is available here
Comment: According to DNB, only dissertations since 1998 are available. I find difficulty to find any clues to get access to one dissertation before that time.
Answer: For French PhD thesis, the most important repository is TeL. Many university now make it mandatory to deposit one's thesis there, so it has a very good coverage for recent years.
Comment: Also [link](https://www.theses.fr/).
Answer: Dutch doctoral theses can be found at:
http://www.narcis.nl/search/genre/doctoralthesis/coll/publication/Language/en
Answer: Italy
In the past, all PhD dissertations in Italy were to be sent in printed form to the Biblioteca nazionale centrale di Roma. It appears, however, that those dissertations can only be read there. The library has an online catalog which, however, doesn't seem to index the dissertations (from the library's website it appears that the PhD dissertations catalog is only in paper form).
For further information about dissertations deposited there, I suggest you to contact the library directly. There is also an international interlibrary loan service (Prestito Interbibliotecario Internazionale).
Nowadays, instead, all universities in Italy have online repositories, and many recent dissertations should be available from these repositories.
Answer: For German dissertations it is often a requirement that the dissertation is "published", which used to mean published by a publisher, though many universities have made this requirement less strict to allow for the new possibilities of the internet. However, publishing with a publisher is still common practice in many disciplines. This means that many German dissertions are not downloadable from the internet. If you have a concrete dissertation you want to read it can help to contact the author directly, they may be willing to sent you a copy.
Comment: I think at least in natural sciences, these days they are usually "published" as a PDF on the university library's website, so most university libraries will have a database with PhD theses.
Answer: In Spain the dissertations are listed on the website of the Ministry of Education, and the Network of Spanish University Libraries.
Most theses of Catalan universities can be found in digital form on tdx.cat.
Answer: There is also DART-Europe https://www.dart-europe.org/basic-search.php which aggregates info about openly available  European PhDs.
Answer: Some university thesis databases are registered and indexed by the international Open Archives Initiative organization. So you can find links to many theses via their search engine OAIster.
Answer: You can find both master and phd thesis in Turkey from the following website:
https://tez.yok.gov.tr/UlusalTezMerkezi/giris.jsp


How to Pick a Journal for Publishing a Research Work?

Question: I got my MS in EE way back in 1994 and have not presented at a conference, or published in a journal before, but I had and still have an intense interest in the applied math that I learned. I have been working my own research project for a few years, and I want to publish a paper on my work. What I did is develop an algorithm similar to a discrete Kalman fiter, and it gives better estimates under certain conditions. I am looking for advice on what journal would a good choice. It would take to long for me to learn LaTeX (is that what it's called), and I don't have the education needed to develop the sophisticated math that I see in many journals.
Comment: Microsoft Word is easier than LaTeX, can do pretty equations, has edit tracking for collaboration and review, and is accepted by most journals.
Answer: Getting work published in a high impact factor journal is quite a slog. If you're starting from not having presented at a conference etc. before, that's going to be an even bigger ask.
However, it's not impossible.
For IEEE journals, short notes about signal processing topics can be sent to the IEEE Signal Processing Letters journal.
However, starting there might be too much.
What I'd suggest is to look at starting with an online journal such as arxiv or PLOSone.
Even before submitting there, I'd suggest posting a question here that might be relevant to the situations where the algorithm might be better than others, and also posting an answer with your algorithm.
The aim with any of these submissions is to get feedback about your work and improve it or its presentation.
Answer: Could you please elaborate on why you would like to publish in a journal? One reason is that your work will be checked (hopefully) by competent reviewers and could be strengthened. @Peter K IEEE Signal Processing Letters suggestion is excellent, as per publication you can as well apply with the same paper to conferences like ICASSP or GlobalSIP (see section Scope in the above link). IET Signal Processing is another option, possibly less selective. There are many other choices, depending on your goal.
You can as well find a neat application, and publish in an applied journal instead of a pure signal processing that may require proofs.
A well written technical note with clean code is a final option, and can be cited as well.
Comment: I am open to presenting at a conference. What are the pros & cons of a conference vs a journal. One thing I want to do is make it easy for others implement & evaluate my algorithm while getting credit for it.
Comment: The real question is why (since you do not publish on a standard basis): share, develop collaborations, get credit, earn fame, be recognized, prove something, improve...? And at what price: time, work, money (I understand no LaTeX, and no maths)? Depending on the order of priorities, a strategy could be devised.


printer recommendations

Question: I recently returned to using a DSLR after several years of just using a point-and-shoot. I would like to get a home printer that's good enough that, when I'm not satisfied with the photo, I can rule out the printer and concentrate on the 101 other variables that contribute to photo quality. I'm a bit overwhelmed right now and just want to find some systematic way to start improving my work. I kind of broke the bank buying this gorgeous Nikon D5200 and a couple of good lenses. I already had a Mac and Photoshop CS6. Is there any relatively inexpensive printer that has both good inks and a straight paper feed? Don't laugh, but, say $300 or less? The photos don't have to be archival and don't have to be larger than 8.5x11 (though it would be nice if they were). I don't care about bells and whistles like wifi or in-printer photo fixing. It doesn't have to be a multifunction printer. I mostly want something that's good enough to experiment and learn on. I suppose for the occasionally really special photo I could have it done professionally somewhere. Thanks very much for any suggestions.
Comment: Oh, and PS -- you guys were great when I was shopping for a telephoto lens.
Comment: Have you considered printing done by a shop? Isn't that going to be cheaper?
Comment: Unapiedra, good point, but I am also trying to learn Photoshop + to be as self sufficient as possible. May have bitten off more than I can chew, we'll see, but still exploring it for now. And by the way, thanks everybody -- not sure what the etiquette is here but I'm not marking any one answer as "accepted" because they're all very helpful.
Answer: I'd recommend either the PIXMA Pro 100 that DavyCrockett mentioned or if you want something cheaper and don't mind being limited to 4x6, one of the Canon Selphy die-sub printers will give really nice quality and a fixed cost per print of around 25 cents.
For the cost, the Selphy is the best bang for your buck, though if you use good papers, the Pixma will do a better job, particularly if you calibrate it, but also will cost more (the paper alone for a similar 4x6 will run you more than the $.25 for the Selphy print, even without ink which is typically similar in cost to the paper.)
I personally was using a Selphy as my primary photo printer until I upgraded to a PIXMA Pro 1 (which is the big, big brother of the Pro 100, but I seriously considered the Pro100 as well).  I'd also suggest that before you pick up a Pro100 if that's what you think you want, check out TryMyPhoto where you can give Canon a photo and they will send you a print from the Pro 100.
Answer: This printer is not $300 or less considering the original price tag, but it comes with a $200 rebate, and up to $300 rebate when buying photo paper. And since you are trying to find a deal I think this could be appropriate as an answer.
Canon PIXMA PRO 100 printer @ Adorama for $389 with a mail in rebate of up to $300 depending on what else you buy.
Pixma Pro 100 @ adorama
The best deal in my opinion and for someone looking for a printer is to buy the Pro Luster photo paper (9"x13") 50x sheets for $69.99.
Pro Luster paper @ adorama
Read the rebate carefully first, for instance everything must be purchased from Adorama.
The printer is rather large (which is a good thing) and I imagine the shipping alone would be at least $50, but Adorama has free standard shipping to make the deal even more sweet.
Pair this printer with high quality paper like the Canon Pro Luster and learn a thing or two in the fantastic How do I generate high quality prints with an ink jet printer? and you could really go above and beyond the level you were hoping to achieve.
Comment: It is worth adding that said rebate is also available from a few other online retailers other than just Adorama, but they all have pretty much the exact same price so it doesn't particularly matter which you choose.  You do need to make sure that whatever retailer you look at has the rebate offer though.  I'm pretty sure B&H does.
Answer: Today just about any printer is good enough, even my cheap office fax/scanner/printer combo has pigment-based "ink" and prints amazing photos if you feed it high quality photo paper.
An actual photo printer like the PIXMA is better than a random printer designed for office use, obviously, but I believe normal people (that is, not photographer or people who work in print) wouldn't be able to tell the difference.
Don't laugh but I recommend you just go into a large office supply store and ask for the cheapest inkjet that has a strait paper path and pigment based ink, I wouldn't suggest this for professionals or for producing museum pieces but it's good enough for learning and you can spend the money you save somewhere else (like a screen and printer calibration device or ink and paper).
By the way, while I do think just about any modern junk inkjet in good enough you do need high quality ink and paper - use only original ink and only good photo paper, also, don't forget to set your printer quality setting to high quality photo.
Comment: I don't know about printers in the last couple years, but the difference is very noticeable in greys and blacks for my few year old multifunction.  The paper gets over-saturated trying to produce detail in dark portions of the image and it becomes pure black.  For photo printing, I'd recommend something with a grey cartridge at a minimum and if it is pigment based, it also really needs a red cartridge since red is more subdued in pigment inks.

printer recommendations


Can I travel to Europe from the US and back to the US on a Mexican passport?

Question: I am a high schooler about to graduate and going on graduation a trip to Europe. I live in the US and am a dual citizen of Mexico and the US. My parents thought my American passport expired in 2020, but after checking, it expires in August of this year, so I need to get my passport renewed to travel. I am afraid it will not get here because I am scheduled to go to Europe in about a month so my American passport might not get here on time. I have a Mexican passport that is not expired yet, and I was wondering if I could use it to travel to Europe from the US? Would I be denied entry upon return to the US? Would I have to get a visa? Even if I am a U.S citizen and resident?
Comment: Are you returning from your trip before or after your US passport expires in August?
Comment: You should get an expedited passport renewal, if you have not already submitted the renewal.
Comment: Fatima, you can very easily get your US passport renewed very quickly - unfortunately you just ahve to pay an extra fee / visit a certain office.  Good luck!
Answer: First, you can apply for an expedited passport, as noted in comments.  Even regular service is quite prompt.  The last time I renewed my passport was nearly ten years ago, but I did not take the expedited service and it arrived in just over two weeks nonetheless.  The passport service is fairly prompt, though things may be different now, I suppose.
If you will be returning to the US before your US passport expires then you might want to postpone getting a new passport.  You can travel to Europe with your Mexican passport.  The Schengen area requires your passport to be valid for at least three months after your anticipated departure from the Schengen area.  Your US passport does not meet this requirement, but your Mexican passport does (or so I assume).
You must, however, return to the US using your US passport.  A US citizen can use a US passport to fly to the US as long as it is valid.
If you do this, you would show your US passport only two or three times:

When you check in for the flight to Europe, show your Mexican passport.  If they ask about your immigration status in the US, show the US passport as well, but point out that you'll be using the Mexican passport in Europe because of the validity limit.
When you check in for your flight to the US
When you arrive in the US

Everywhere else, that is, to European immigration officers, show your Mexican passport.

Would I be denied entry upon return to the US? Would I have to get a visa? Even if I am a U.S citizen and resident?

You cannot fly to the US using (only) your Mexican passport, because no airline will allow you to board the plane with that passport unless it has a US visa in it.  But you cannot get a US visa because you are a US citizen.
Having said that, you cannot be denied entry to the US because you are a US citizen.  If you were to find yourself in Europe after your US passport expired, you could do one of a few things, including:

Fly to Canada or Mexico with your Mexican passport and then apply for entry at the land border using your expired US passport and any other evidence of US citizenship you might have.
Apply for a US passport at the nearest US embassy or consulate.
Wait for your new passport to arrive at home and have someone send it to you.
Answer: From EEA (Europe) website (link below0 "There are thirty-nine countries, including Mexico, whose citizens do not require a visa to visit the EU for a period of up to three months." The same applies to the UK.
Remember to bring evidence that you'll be leaving Europe at the end of your trip, such as return ticket. Be able to demonstrate that you have access to sufficient funds to support yourself. Bring evidence of medical insurance/travel insurance. Have some accommodation booked and if staying with friends/family write down their addresses and phone numbers, 'cos some airport wifi signals are poor and it's tricky if you can't easily provide this info to the Immigration Officer.
 Link
https://eeas.europa.eu/delegations/mexico/14899/travelling-and-studying-eu-mexico_en
Comment: That's true, but it doesn't address the other half of the OP's question, which is returning to the US using a Mexican passport, which isn't going to work assuming the plan is to return to the US by air.


Interpolation formula for two dimensional signal reconstruction in the frequency domain from polar samples

Question: In the book, Advanced Topics in Shannon Sampling and Interpolation Theory by Robert J. Marks II, one may find an interpolation formula for reconstructing a two dimensional signal from regular polar samples in the frequency domain:

Let $f(x,y)$ be space-limited to $2A$. Let its Fourier transform in polar coordinates $F(\rho,\phi)$ be angularly band-limited to $K$. Then $F(\rho,\phi)$ can be reconstructed from its polar samples via
$$F(\rho,\phi)=\sum_{n=-\infty}^\infty\sum_{k=0}^{N-1}\widetilde{F}\left(\frac{n}{2A},\frac{2\pi k}{N}\right)\operatorname{sinc}\left[\frac{2A(\rho-n)}{2A}\right]\frac{\sin\left[\frac{1}{2}(N-1)\left(\phi-\frac{2\pi k}{N}\right)\right]}{N\sin\left[\frac{1}{2}\left(\phi-\frac{2\pi k}{N}\right)\right]},$$
  where $N$ is assumed even and
  $$\widetilde{F}\left(\frac{n}{2A},\frac{2\pi k}{N}\right)=\begin{cases}F\left(\frac{n}{2A},\frac{2\pi k}{N}\right),&n\ge 0,
\\
F\left(-\frac{n}{2A},\frac{2\pi k}{N}+\pi\right),&n<0.\end{cases}$$

I figured that the argument of the cardinal sine function contained a typo, since the $2A$ in the numerator and denominator would appear to cancel. Thus I would guess that the author actually had
$$\operatorname{sinc}\left[\frac{\rho-2An}{2A}\right]$$
in mind. Correct me if I'm wrong?
Then the last quotient with the sine functions looks very similar to the Dirichlet kernel:
$$D_N\left(\phi-\frac{2\pi k}{N}\right)=\frac{\sin\left[\left(N+\frac{1}{2}\right)\left(\phi-\frac{2\pi k}{N}\right)\right]}{\sin\left[\frac{\phi-\frac{2\pi k}{N}}{2}\right]}$$
but is not quite the same.
Incidentally, my attempts to implement the interpolation formula in the theorem via Matlab for specific examples have failed completely with regards to reconstructing a signal. Perhaps someone can point me in the direction of a correct formula for signal reconstruction in the frequency domain from polar samples?
Answer: I haven't worked through the algebra, but this page just before that equation:

suggests that
$$
\operatorname{sinc}\left[2A(\rho-\frac{n}{2A})\right]
$$
might be the correct form of the $\operatorname{sinc}$ term.
Comment: Then this is the same as $$\operatorname{sinc}\left[\frac{\rho-n\Delta\rho}{\Delta\rho}\right],$$ with $\Delta\rho=\frac{1}{2A}$. Interestingly I also tried to implement this formula on Matlab too, but with no success.


Moen Bathroom Faucet Handle Removal?

Question: I'm trying to change the cartridge on a Moen bathroom faucet but can't get the handle off.  The handle base will turn counter-clockwise but reaches a certain point and stops.  You can also unscrew the part of the handle that sticks out and remove it but I don't see a set screw to turn.  I'm the original owner but I don't have a model number or instruction manual.
Comment: Try gently to pry off the the round cap on top, or perhaps the little round nub on the side/back of the handle, or  rotate the handle itself counter clockwise to see if it comes off.
Comment: https://www.moen.com/customer-support/cartridge-replacement
Answer: I have that exact one. Yes, there is a little screw under the cap that is on the top. You will need something with a fine edge on it to begin prying that up, I use a box knife, then once it is up a little, you can get a flat screwdriver tip under the lip and finish getting it off. Loosen that screw and the HANDLE comes off, but you still have to unscrew another nut underneath, and that needs a socket wrench. If you don't have one, plumbing stores and home centers sometimes sell inexpensive tubular steel sockets specially designed for this (they are no good for working on your car, but they are OK for these). Here is a picture of a set that covers all of the possible sizes, it sells for around $8 in most places (assuming USA). You only need one size but it's hard to know WHICH size as they are all different from one another by 1/32nd of an inch increments.

Just make sure your water is off BEFORE loosening that nut!
Once you get there, these stems are usually "washerless" in that they have a little O-ring that slides along a brass plate and over time that O-ring wears down. Sometimes all you need do is TIGHTEN that nut to squeeze that O-ring down a little harder. Try that first. If it still drips, then remove the nut and back out the stem, you will see where the O-rings sit. Get and install replacements, they sell them in kits.
Comment: Yes, that did it!  I couldn't commit to prying that cap off without knowing it actually came off.  Thank you!

Moen Bathroom Faucet Handle Removal?


When you read sheet music do you read the notes or the intervals?

Question: I have found myself doing both but not sure which is the right way. Sometimes I see a note then I can see the next note is a 4th above it so I play it but I actually don't know what note I just played if that makes sense. I only know it was a 4th up from the last note. Is this wrong?
Comment: Would be helpful to clarify what instrument you're asking about, and whether you're talking about melodic intervals are harmonic.  For piano, I find myself thinking in terms of notes for horizontal reading (melody), but intervals for vertical (harmony/chords)
Comment: in a lot of cases, I recognize shapes I've seen before and I read the lowest not to see where it starts
Comment: If you're playing the right music, I don't see how it's wrong.  There's a degree to which this question is like asking people if they read the letters when they read text.
Comment: I used to read the intervals and try to understand the harmony vertically, but as I got better I read just the actual notes. It's far quicker.
Comment: "the right way" is the way that works best for you.
Answer: We get to a point where we do NOT look at a dot, think 'that's a D', then find it on the instrument. And it could be any instrument.
We often see how many lines or spaces (or combinations thereof) separate notes, and play accordingly.
Sometimes we even second guess where we think the tune may go, and stab at that note.
There are many tricks we use, and intervals is one of them.
EDIT: just to add that having the scale notes of the key on high alert makes life that little bit easier - partially because when accidentals occur, it's clear that those notes will be among the five we've avoided - until now!
Comment: In other words, the way I usually work out what some music is supposed to sound like, is to play it.
Comment: Indeed. Usually when reading+playing a note I don't think "D", nor do I think "this fingering and embouchure". Instead I simply adopt the physical position required to produce it. How? Practice. Reading without playing is a different matter, and I'm usually (with wildy varying degrees of success) imagining the sound in my head based on relative spacing and intuition of the tune.
Comment: @OrangeDog and Tim: I agree. It even extends "In To The Future": Not only do I see that there's a D note coming, my "look ahead buffer" also sees (and recognizes) a couple of notes to be played in the same-or-very-shortly-thereafter time. I tend to auto adjust my fingering (I play guitar) to the most likely place this can be done without a hassle, and I'd say I'm right at least 70% of the time. For fingerings that just leave one option it mostly happens just automatically: My fingers just keep me out of the loop, and do what they know they should be doing ;)
Comment: Agreed.  One has to become trained enough, similar to "muscle memory," that you don't even consciously think "this note"  or "this interval."  You just go.
Answer: I don't think this is wrong at all; my sight reading is a mixture of these components, as well.
The fact is that part of sight reading is based on common patterns. This is one of the many reasons why we work on scales and arpeggios and the like: when we encounter them while sight reading, we can call upon that ingrained memory to easily perform the task.
And some of these common patterns are interval based, which allows us to sight read larger portions of music without knowing every single note that's being played. Seems perfectly fine to me!
Answer: Perhaps both are good, and there are other options.  How one reads is instrument dependent.  On the guitar for example we eventually learn to read chords.  This can pose a problem for beginners as they feel like they need to stop at the chord and climb up it, reading each note one by one and finding it.  In fact this is not a good way to read chords.  One is much better off identifying the intervals and then grabbing the them with the hand.  Good guitar books teach one how to identify the chord shape (what the hand needs to do to get the chord in standard tuning) with the stack of dots on the sheet music.  If taught correctly, and practiced, one can learn to read chords on SMN with no problem.
Sometimes I look for geometric shapes in the music and relate them to scales arpeggios and intervalic leaps.  My hand knows what to do.  This also makes transposition on the fly easier.  There is no need to force yourself to read by note name identification.
Comment: Guitar is a hard instrument to sight-read on. So many notes can be played in different positions. On the piano there are more notes but at least they're always in the same place!
Comment: @OldBrixtonian: If played with a scordatura E2 => D2: Most definitely ;).
The only other option would be very awkward, or at least it would be for me. Not something I'd comfortably switch to at speed (on a classical guitar).
Comment: There is a logic to it.  With the right guidance and practice it becomes pretty easy.
Comment: It's beyond me! But I barely play the guitar. I just use it to work out if something I'm writing is possible. (I'm currently trying to decide whether the chord D F A C# E is useable. Is it? I can't keep my finger clear of that open E string!)
Comment: @Willem van Rumpt Thank you! Sorry - I only just saw your message. That's a solution I hadn't thought of. The session was a few days ago and we had to drop those bars in later to give the guitarist time to position his fingers. Even HE didn't think of tuning the top E down! Damn! We could have done it. It would have sounded better. That top note never did ring properly. Electric guitar, by the way. And there was no question of me re-writing it in a better key, as it was all being grafted onto some orchestral thing I'd already recorded. I really appreciate your help, Willem.
Answer: There is a big gap from a beginner's sight-reading to an experienced musician's sight-reading.
Sight-reading consists of reading the notes, the intervals, rhythm patterns, scale patterns, chords patterns, broken chord patterns, key signatures, tempo indications, articulations, dynamics and any other indications that might appear in the sheet music.
The beginner reads one note at a time, a skilled sight-reader reads many notes at the same time as well as the relation between the notes, and that relation is composed of intervals and all those patterns mentioned above.
A good sight reader can read a whole bar with just one glance at the bar, well dependning on how complicated the bar is of course. Some bars need a close look at details, others are simple and easy to read.
There can be differences on how you read depending on which instrument you play. I play both the violin and piano myself and the sight reading are different on those two instruments although the points I wrote above are valid for both of them. But the way you read is related to the instrument you play in that you relate the notes to the instrument. You see a note and immediatly think of that particular place on the instrument. This means that despite that playing technique is a different subject you do relate what you read to the playing technique. You are of course concerned about how to play it.
Here are some examples:
Answer: This is not wrong, and it may be individually better for a singer or violinist.
But:
Identifying the notes, realizing their position in the staff, their function in the scale, their value, position and function in the chords, recognizing motifs, Melodic patterns, sequences, keys ... everything is helpful, useful, everything makes sense, also the interval to the previous note, but this latter is the less important to me, only regarding other aspects like solfege and harmony.
Comment: @RedSonja - vox and Theramin both have that same problem - there's really nothing tangiable to work with. Intervals is about all we have.
Comment: String instruments (particularly fret-less ones like the violin or cello) have the added complication that the space between intervals is not constant along the length of the string.  You can tell when looking at one with frets like a guitar that the notes are much closer together near the sounding board than at the far end of the neck, and this is equally true of fret-less, you just don't have the convenient markings, so it's just something that comes with practice.
Comment: Right; on sax or clari I know where the notes are. I see a D, my fingers make a D. But when singing, after a few bars I have no idea "where I am", tone-wise. it only works out with intervals.
Answer: On the piano:
In chordal passages I think it's the shapes of the chords I take in. Like which inversion. If the note-heads are all on the same side of the stem it's going to be a simple chord. If one of the note-heads is on a different side from the others, its position on the stem tells me it's going to be this type of chord, or this type.
In fast passages where the hands are jumping between registers and I can't afford to take my eyes off the music, I think my fingers slightly trail along the black note groups to find the right location. Sounds ridiculous when I describe it, but I think a slowed-down film would show that.
With runs of notes I think I think(!): 'Looks like a scale. Yes, with an accidental. Where does it end up?'
Then, 'Here comes another one. Looks like the same length.'
As Tim said, it often involves guessing. 'It's likely to be this'.
In easy passages I think I glance ahead at any difficult bits coming up.
Answer: My recommendation is to read as many notes as possible and practice it this way if you are beginner specifically. You can get away reading a few intervals but if one is wrong the others automatically become wrong, so avoid it as much as possible.
In short: Read the notes, read the intervals to get by only (If you are a beginner).
BOTH. (If you are intermediate.)
Once you start getting bette, notes and positions on the instrument get more ingrained into your mind and you will make less mistakes in their judgement, then you can start noticing the intervals on the sheet music and on the instrument.
Also don't forget to not overlook the key signatures.
Answer: With experience, and when a piece lies within your comfort zone, you read the patterns.  Like 'look and say' in reading a book. When an unfamiliar pattern presents itself, you may have to stop and look at it in a more analytical way.
There's another stage, particularly when playing non-classical (for want of a better term) music like a song copy or a lead sheet, where you just read the music. Easier to do than to describe!  You take in what the music DOES rather than the specific notation, and you play something appropriate.
There can be a danger of doing this too much.  Sometimes I have to pull myself back with 'Hey, this looks like quite a neat piano part!  Perhaps I should try playing what it SAYS...'


ROS + SLAM + kinect. which platform to use?

Question: I am doing a project where I've robot which will be using kinect + ROS for Simultaneous Localization and Mapping. Which board should I use? I've heard that Raspberry pi , beaglebone are not sufficient.
Answer: There are several platforms possible, depending on your experience level and needs.
If you are comfortable working with the Raspberry Pi or the Beagle Bone... the next step up might be the Jetson TX1 or TX2 from Nvidia.  Please note that the default install of OpenCV4Tegra does not include the slam modules, so you will have to install OpenCV from source if you plan on using that library for SLAM/SIFT.  ROS can be installed on the Jetson following this guide.
Qualcomm also makes the snapdragon line or processors and there are many other chips out there, too.
Please review the guidelines for your question since it seems highly opinion based.  Consider rephrasing/asking a more specific, technical question.
Answer: Nvidia Jetson TX2, I have one and it is pretty fast. There are so many boards, I prefer ARM for prototyping, but you can use notebooks, Intel IoT boards, Mbed like Nucleo, small motherboards. It is huge the number of possibilities.
Kinetic does not need much processing for create a point cloud so you don`t need nothing fancy.


Expectation of function of stochast

Question: I've got a general question regarding a certain sticking point I often encounter. When tackling questions where for example an UMVUE (uniformly minimum-variance unbiased estimator) has to found I get stuck at the part where an expectation has to be determined. Maybe I'm overlooking certain theorems.
Example 1.  Consider a random sample of size $n$ with $X_i\tilde{}Poi(\mu)$.
I am able to find the UMVUE of $\mu$ and the MLE (Maximum Likelihood Estimator) of $\theta=e^{-\mu}$. But then for example follows the question: is this MLE unbiased for $\theta$?
If I want to determine the expectation, should I just write out the sum as follows from the definition of the expected value of a discrete distributed variable? This seems to lead to quite an ugly expression...
(For this particular problem I found that Jensen's Inequality could come in handy to show biasedness (or actually non-unbiasedness))
But if I could summarize the problem I've got: how to rewrite expected values of functions of stochast in general?
Which theorems or properties should I use... for example I do use $E(aX)=aE(X)$ for $a$ a constant and $var(X)=E(X^2)-E(X)^2$ to rewrite certain expectations to a combination of simpler/known ones.
Example 2. Take a random sample $n$ of a distribution with pdf $f(x;\theta)=\theta x^{\theta -1}$ if $0<x<1$ and else $0$ and with $\theta > 0$.
Find the UMVUE of $\theta$
Here I get stuck again at the expectation. I've got a sufficient and complete statistic in
$\sum ln(X_i)$.
The expected value, i'd figure, is equal to $nE(ln(X_i))=-n/ \theta$  $\,\,\,\,$(where $[-ln(X)]=\frac{1}{\theta}$ was given as a hint).
But what if I want to determine the expected value of $\frac{1}{\sum_{i}ln(X_i)}$ ?

In general: how to determine the expectations of functions of stochasts?
For example $E[ln(X)]$or $E[e^{\bar{X}}]$...?
Answer: If $X$ has density $f_X$, then for every function $u$, $E[u(X)]=\displaystyle\int u(x)f_X(x)\mathrm dx$. For example, in your last case,
$$
E_\theta\left[\frac1{\sum\limits_i\ln X_i}\right]=\iint\cdots\int\frac1{\sum\limits_i\ln x_i}\prod_if(x_i;\theta)\prod_i\mathrm dx_i.
$$
If $X$ is discrete and $p_x=P[X=x]$ for every $x$, this should read
$E[u(X)]=\displaystyle\sum\limits_xu(x)p_x$.

Expectation of function of stochast


Guarenteed patenting service, free for failed cases

Question: Are there attorneys who charge no fees if patent is not granted?
Comment: This would have to be a yes or no question, or perhaps describing how you would find such a service, but please note that we do not allow personal solicitations for legal services on this site.
Comment: Yes looking  where  credible patent professionals advertise, there is no tag.
Answer: Its a situation dependent solution, single one time inventor or educational institute may get pro bono services from various attorney firms (screen their respective websites).
How to search is tricky as these kind of services are not reported in any patent database, but any search engine boolean search may lead you to some hits Example.
If its a commercial applicant then this may further require:-

under contract of revenue share on IP licensing.
selling of IP right to firm.
First upfront payment fee for accepting a case or evaluation of case.
Answer: That is between you and the patent attorney of course, but you might want to consider the quality of work done by an attorney prividing a money back guarantee. Even if he or she gets your invention patented (thereby earning their fee under the proposed arrangement) it may very well be drafted poorly such that your patent offers narrow protection and a smart inventor or company can easily work around your patent. Many perfectly valid patents fall under this category and are not worth as much as a broader, well crafted patent.
But you should also take into consideration the USPTO fees, all of which are nonrefundable. See fees here: http://www.uspto.gov/learning-and-resources/fees-and-payment/uspto-fee-schedule


GPS for WiFi only MiPad

Question: I have a MiPad which works only with WiFi. How do I use it as a GPS device? Google map isn't able to access my location and my MiPad doesn't support tethering.
Answer: I found the solution on MIUI website here:
(Click image to enlarge)

Prerequisites:

Have a device that has GPS built-in and tethering/hotspot.  In my case, I'm using the Xiaomi Mi 3.
Download and install TetherGPS Lite on both the Xiaomi Mi 3 and Xiaomi Mi Pad.

How it works:

In the Xiaomi Mi Pad, enable Settings-Developer Options-Allow mock locations.

GPS location must be enabled on both devices.

On the Xiaomi Mi 3, enable Settings-Wireless & networks-Tethering & portable hotspot-Portable hotspot.

On the Xiaomi Mi Pad, enable Settings-WLAN and I connect to my Xiaomi Mi 3 hotspot.

Start TetherGPS on both devices.

On the Xiaomi Mi 3, click on Start Server.
On the Notifications bar, you will see the IP of the TetherGPS Server.  Note it down.

You will also see that your device will be searching for the location until it is found.
On your Xiaomi Mi Pad, click on Start Client.

Under the Notifications bar, if you find that TetherGPS Client is not working, go into the TetherGPS app.  Uncheck "Automatic Broadcast IP" and key in the IP you noted down earlier.  Click on "Stop Client" and on "Start Client" again.

If the setup is working, you will notice that both Notifications bar will show the connection time of TetherGPS.
Start your Google Maps or any other navigation apps and enjoy driving from point A to point B using your big 7.9" screen.
Comment: Hi! I added the images from that thread. They are important, so I believe they mustn't be left behind. Please make sure of this fact from the next time. :)
Answer: The solution for one of your problem is here .
You can enable hotspot on your MI Pad
https://m.youtube.com/watch?v=w0DLbEnHspw
Yes you can do it.
Ie is what you want if you use xender, interconnected games or shareit.
Have a happy time from here after

GPS for WiFi only MiPad


Are the digits of irrational/transdental numbers random?

Question: If I were to look at the decimal representation of some irrational
or even transdental number,
and if I choose a natural number at random
can I expect that it is some digit with probability $0.1$ ?
Comment: Look at normal number http://en.wikipedia.org/wiki/Normal_number. Almost all numbers are normal.
Comment: Concerning the question from the title see [Liouville number](http://en.wikipedia.org/wiki/Liouville_number).
Answer: In general all digits of an irrational number do not have to occur with equal probability.  A quick example would be the number $$0.1011011101111011111...$$
Here, the number is composed of only $1$'s and $0$'s, so the probability for digits 2-9 is zero.  In fact, depending on how you define the probability of finding a digit, the probability of randomly selecting $0$ from the digits might also be zero.  This is the case if you define the probability for the infinite decimal representation to be the limit  as $n\rightarrow\infty$ of the probability of finding the digit in a truncated approximation of the number with $n$ digits.
Even with this definition, you could get irrational numbers where this limit doesn't exist for some digits.  An example would be something like
$$0.101100111111000000...$$
where after each run of $0$'s you keep appending a $1$ until the probability of finding zero in the truncated representation is less than $1/4$, and then you go back to appending $0$'s until the probability of finding a $0$ has gone back up to $1/2$.  In this case, our definition for the probability of finding $1$ or $0$ in the infinite decimal representation doesn't give an answer, because the limit doesn't exist.
So I guess the point is that probabilities are a bit tricky to define for infinite sets of numbers, but in general irrational numbers do not have to have equal probabilities for each digit.
Answer: Presumably by "at random", you mean "uniformly at random". There is no uniform distribution on the natural numbers; see Probability of picking a random natural number.