OFDM Signal and IQ Paths

Question: I understand that we have analog complex signal after it passes DAC after coming out of IFFT in OFDM Transmitter. After that we do orthogonal upconversion on it and send it.
I've question now for OFDM Reciever, suppose i recieved a signal then i separated I & Q component, for processing anything on the signal now I've to do processing separately on I & Q Paths (independent paths) does the orginal OFDM Signal even has any significance until i combine I & Q back at input of ADC ? because before ADC everything is split at recieved end in I & Q path and processing is done on it. Little confused, may be I'm thinking too much, pls guide.
Comment: I guess you know how to down convert the received RF signal to baseband and how to separate I and Q. Then you combine them into a complex signal and do ADC (or you do ADC on each of I and Q and then combine them into a complex signal). After that, do FFT on the combined complex signal to recover original modulating symbols used in the OFDM modulator in the transmitter.
Comment: @user295357 Suppose at the transmitter part, i have following equation x(t) is complex baseband signal and w is rf frequency
x(t) with e^jwt = i(t) cos wt - q(t) sin wt + j q(t) cos wt + j i(t) sin wt, and then i pick real part of it and send i(t) cos wt - q(t) sin wt = r(t). Now at reception end I'll again do the following r(t) * e^ jwt it will yield real part having cos square wt and imaginary part sine square wt, how do we filter real and imaginary part? Can you show the maths pls
Comment: See my response as an **Answer** since it is too long to be a ***comment***.
Answer: @Reddi Suresh
Denote the received RF signal as $r(t)$. In the receiver, do following three things for down-converting and recovering $i(t)$ and $q(t)$.
(1) Multiply $r(t)$ with $2cos(\omega_0t)$, that is,
$c(t) = 2r(t)cos(\omega_0 t)=2i(t)cos^2(\omega_0t)-2q(t)sin(\omega_0t)cos(\omega_0t)$
$c(t)=i(t)[1+cos(2\omega_0t)]-q(t)sin(2\omega_0t)$.
(2) Multiply $r(t)$ with $[-2sin(\omega_0t)]$, that is,
$s(t)=-2r(t)sin(\omega_0t)=2q(t)sin^2(\omega_0t)-2i(t)cos(\omega_0t)sin(\omega_0t)$
$s(t)=q(t)[1-cos(2\omega_0t)]-i(t)sin(2\omega_0t)$.
(3) Passing each of $c(t)$ and $s(t)$ through a low-pass filter to remove all components whose frequency higher than $\omega_0$, you get $i(t)$ and $q(t)$ respectively.
Equivalently, if you like, you can expresse the recovered $i(t)$ and $q(t)$ as a complex signal as
$i(t)+jq(t)=LPF\{2r(t)e^{-j\omega_0t}\}$
where $LPF\{.\}$ stands for low-pass filtering. This can be easily verified based on above equations.
Answer: This answer assumes a clear understanding of "negative frequencies" and how it relates to real and complex signals. If that concept is not very clear, reviewing this post first may be helpful. Please also see this post that is directly related to the OP's question.
I think the confusion is with "Separating into I and Q components". There really isn't a "separation" but using complex representation to represent the signal. For real signals at baseband, the spectrum centered about DC is complex conjugate symmetric: the negative frequencies which represent the lower half of the spectrum is identical to the positive frequencies (which represent the upper half of the spectrum) other than phase reversal. They are completely redundant. Whatever is centered about DC for the baseband signal becomes what is centered about any carrier frequency that we translate the signal to in the up-conversion process. We care a lot about spectral occupancy, so that redundant spectrum if we used a real baseband signal means we use up twice as much spectrum as we need to. This is why most modern waveforms have a complex baseband spectrum: with that the positive and negative frequencies at baseband are completely independent (and therefore the lower half and upper half of the spectrum at any real carrier frequency it is translated to will be as well). This immediately doubles are spectral efficiency, which is a valued trade for the increase in hardware complexity.  To do this just means the baseband signal (when centered at DC) must be complex. That one signal is represented by its real ("I" for in-phase) and imaginary ("Q" for quadrature) components-- it is still one signal, we just need two data paths to represent it. Just as we need two real numbers on paper to represent a complex number using either cartesian or polar coordinates.
A main point is summarized with the graphics below comparing spectrums for real and complex baseband waveforms (centered at DC). In order to have a spectrum that has independent positive and negative frequencies (as we see on the right), the waveform must be complex.

If we frequency translate both of the waveforms given above to a real carrier frequency, we get the resulting passband spectrums shown below (showing the magnitude only for simplification but the phase would also translate accordingly):

The difference in implementation for translating a baseband signal (whether it be real or complex) is shown in the simplified diagrams below (filtering to make this complete is not depicted). This shows translating from baseband to an RF or IF carrier frequency. The reverse process for received (translating from RF or IF to baseband) would be similar in reverse form:

So in short we take an IFFT of the data in the transmitter to get a complex baseband signal. We frequency translate that to a real carrier. In the receiver we do the opposite: we frequency translate the waveform from a real carrier to complex baseband, then with the complex baseband signal we take the FFT to recover the data (simplified as there are a lot of details with framing, carrier and timing recovery etc in the receiver).
Where we do the ADC and DAC in the above process can be anywhere technology allows (we can do baseband sampling with two ADC's or RF/ IF sampling of the real signal at a carrier with one ADC for example), it doesn't change the processing, it just changes whether the signal is represented in analog or digital form.
For further details on quadrature (IQ) frequency translation, this post may be of interest.
Comment: Yes and I totally get yours....there's no "right answer" just different ways of looking at things and what "reality" means to us. I had figured you meant SSB and it was a nice example.
Comment: Anyway, $i(t)$ and $q(t)$ carries independent information, thus at some stages of processing, they have to be separated, otherwise the transmitted information would not be useful to the destined user. As long as $i(t)$ and $q(t)$ finally can be correctly recovered (including being correctly separated) finally in the receiver,  there is no essential difference whether they are viewed as a single complex signal or two independent real signals at each stage. From another point of view, the benefit to express them as a complex signal is to make them separable.
Comment: It is true that with an RF frequency band, if only the cosine carrier is used to transmit a real baseband signal, the band is not efficiently used, since the sine carrier is not used to transmit another independent real baseband signal with the same RF band. Both cosine and sine carriers can be used because they are orthogonal, so that the two real baseband signals can be separated. Another possible way to avoid waste of the bandwidth when only one RF carrier is used is to transmit single-side-band (SSD) signal based on the Hilbert transform theory.
Comment: @user295357 Respectfully I don't see your point (yet). I do note that there is no way to express a complex number without using two real numbers so we always "separate" on paper and implementation- but still it is always one complex waveform and it greatly simplifies are thinking to see it that way (in my opinion).
Comment: Also single-sideband and Hilbert transform theory is all well described with complex numbers, I don't really see it as a different approach. For me using complex number representations greatly simplifies the processing. (We can of course refuse that approach and describe all signal flows as separate paths with sines and cosines; I've done both approaches and am sold on the utility of complex representations-  bottom line is either are just that: the representations we use.  This may help: https://mriquestions.com/uploads/3/4/5/7/34572113/quad_signals_tutorial-lyons.pdf
Comment: In deed, SSD signal is a complex signal, but there are distinct differences compared to, say, the QPSK (or OFDM) like complex signal. In SSD, the imaginary and the real component are not independent but are connected by Hilbert transform, while in QPSK-like signals, the imaginary and real parts are independent. More important, if you exam the instant spectrum of these two types of signals, they are completely different. Of cause, their implementations are also different. In the history of communication development, SSD once was quite popular, such as used in both audio and TV broadcastings.
Comment: In my point of view, in real (physical) word there is no complex waveforms existing. Complex signal is simply a mathematic convenience to express two separable real signals. It provides certain convenience for mathematics operations. Also, if you are working with software coding for signal processing, it do provide convenience. But again, in physical reality, there is no complex waveforms.
Comment: Right, yes I see what you are referring to; SSB being completely one-sided.  As for saying complex signals don't exist and are a mathematical convenience, I have a different perspective. Both "complex" and "real" are math to me. "Complex" signals exist just as much as "real" signals do. Perhaps we don't like having to use two real numbers to represent a complex number but we do that on paper as we do in implementation so how can we say one doesn't exist and the other does? I know it gets philosophical but it's my own choice to treat them both the same in terms of existance :)
Comment: The idea of using complex numbers in physical implementations is one of the motivations for this favorite question of mine; we can use real numbers to represent a waveform we measure with a single scope probe, and we can use complex numbers to represent a waveform we measure with two scope probes - both waveforms have similar "existence" to me and we use math to represent them: https://dsp.stackexchange.com/questions/31394/9-rm-v-battery-with-45-circ-phase   (not saying your point of view is wrong, I understand where that comes from)
Comment: Sorry for I typed "SSD" by mistake for 'Single-side- band' in my above comment. It should be 'SSB'.
Comment: Hi Dan, I understand your point. That is fine. Have a nice day.
Answer: Note that the IFFT sequence for one set of complex numbers (vectors) transmitted through a communications medium is not periodic. So that single transmitted complex time-domain sequence is not going to be 'OFDM' because it is not a periodic sequence. This means that this taught IFFT method for OFDM generation should be taken with a grain of salt. The transmitted sequence is actually just I/Q transmission (quadrature modulation). You would only get 'OFDM' if each IFFT sequence is periodic, and that is not going to be possible due to needing to send lots of different IFFT sequences in succession. So the IFFT transmission does not produce a physical OFDM spectrum at all. That is, the transmitted IFFT 'signal' is not even an 'OFDM' signal as such.

OFDM Signal and IQ Paths


What U.S. constitutional rights do federal/state prisoners have?

Question: Are your constitutional rights limited once you are convicted of a crime and sentenced to prison? Is there any clause in the US constitution that deals with this or is it simply based on crime one has committed?
Comment: As it stands, this question is extremely broad. There is a wide area of litigation dealing with what rights prisoners have and under what standard those rights are evaluated. Is there anything specific about prisoner's rights that you'd want to know?
Comment: Are you talking about the constitutional rights of prison inmates while in prison or the rights of ex-convicts after release?
Comment: More specifically, inmates who are in prison and since it's a broad topic, let's for the sake of time, talk about 1st, 5th, and 8th Amendments
Answer: Yes, many constitutional rights are limited upon conviction and imprisonment.  Most notable among these is the right of liberty.  The major constitutional clause is the "due process" clause of the fifth amendment that requires due process of law for limiting certain rights:

... nor shall any person ... be deprived of life, liberty, or property, without due process of law....

The fourteenth amendment extends this prohibition to the states, along with some others (emphasis added):

All persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
Comment: @lazarusL the fifth and fourteenth amendments explicitly prohibit the deprivation of liberty without due process of law (see edit).  Most constitutional rights are not explicitly described as a "right to X"; rather, they are defined by restrictions on what the government may do.  For example, freedom of speech is effected by a statement that "Congress shall make no law ... abridging the freedom of speech."
Comment: What do you mean by "right of liberty?" I'm pretty sure that phrase isn't present in the US Constitution.
Answer: It would be simpler to list the rights they lose. The most obvious rights lost by people convicted of a felony are the rights to vote, the right to bear arms, and to a degree, the right to be free of unreasonable search and seizure. On occasion, a convicted felon can petition to have some of those rights restored, but said restoration is not automatic.
If you don't like that... don't commit a felony crime.
If one joins the military or gets a security clearance, they agree to give up their right to free speech, at least on subjects related to their military service or security clearance. Arguably, one joining the military gives up their right of liberty and pursuit of happiness... unless someone derives happiness from pushups and swabbing out latrines.
Comment: The only explicit mention of a right to pursue happiness is in the Declaration of Independence, which does not have any bearing on the rights enjoyed by people under US law.
Answer: The accepted answer covered the 5th amendment pretty well, so I'll focus on the 1st and 8th.
First amendment rights, as far as the practice of religion, are somewhat well protected. Prisoners are allowed to practice the religion of their choice, religious texts are often provided and diet restrictions mostly respected. Free speech on the other hand is often limited by institutional rules...
The standard for restricting speech in prison is pretty broad, as established in Thornburgh v. Abbott in the US Supreme Court:

The First Amendment does not prohibit the Federal Bureau of Prisons
  from rejecting certain publications if said publications are
  detrimental to penological interests.

This combined with other case law more or less says that speech, correspondence, and reading materials may be restricted if it can be deemed potentially dangerous.

8th amendment rights are a hotly contested issue and are pretty constantly being challenged in the courts...

Excessive bail shall not be required, nor excessive fines imposed, nor
  cruel and unusual punishments inflicted.

Obviously this is being argued in nearly every bail hearing where a person's ability to pay is in question.
Perhaps more controversial, the meaning of "cruel and unusual" is constantly being challenged and refined. Look into recent debates about solitary confinement and the death penalty.
Cruel and unusual punishment is a charged topic and probably too broad to get into here, but most cases involving the treatment of prisoners are tied to how we define these words. Everything from healthcare, to diet, and even yard time have been informed by how courts have interpreted them.


Why has President Erdoğan threatened UAE when Turkey itself has diplomatic relations with Israel?

Question:
Turkey may recall ambassador in UAE, suspend diplomatic ties, Erdoğan says

Why has President Erdoğan threatened the UAE when Turkey itself has diplomatic relations with Israel?
Comment: Incredible example of hypocrisy on the worldwide politics stage.
Comment: More context will be helpful for anyone bumping into this question in a few months or years...
Comment: If you study the history of Israel and diplomacy, you will notice that nothing about it is really logical and there is obviously a Higher Hand guiding the actions of the countries.
Answer: As the article you link to in the question alludes to, Turkey's conflict with the UAE runs deep. Particularly notable is this bit: "Turkish officials have accused them of offering financial and logistical support to the PKK terror group to carry out attacks in Turkey." So, criticizing the UAE about Israel may not really be about Israel at all.
It's also worth nothing that, Turkey has had relations with Israel since 1949, in a very different world. But the relationship is often tense. It's a lot easier for Turkey to show displeasure with Israel by criticizing UAE then it is to take the more radical step of breaking relations with Israel.
I don't expect you will find anyone in the Turkish government offering any direct explanation for the apparent contradiction, but I think these two points together do make it somewhat easier to comprehend where they may be coming from.


Would it work if I glued a new closet flange to an existing closet flange?

Question: abs closet flange is 1 and half inch lower than floor. the flange inlet is ID 4 inches. I am thinking of use some abs cement to glue a new abs flange into the existing one. (I assume 4x3 flange can go fit snugly into a 4 inch inlet?)  I did some google search but have not found anyone recommending doing this.  Would it work?
Comment: Doubt it would last even it you could get a good bond.
Comment: You can buy spacers and longer closet bolts to overcome the difference. You wouldn't want to add another flange over it.
Comment: so the spacers actually extends the existing flange to the floor level? How is that different from cementing a new flange?  It appears that cementing a new flange provides a water-tight air-tight connection. However I am not sure how the spacer can create a water-tight connection with the old flange.  Maybe put some wax or rubber gasket between the old flange and spacer?
Answer: Usually if the flange is not high enough, a larger wax ring is used or stack two wax rings together. Yours sounds like it is lower than any I have ever encountered. A good plumber with an internal pipe cutter could cut it with out damaging the floor, add a coupler, and with some proper material to hold the flange at the right height, reset a new flange. Seal that to the surrounding finished floor, so if the wax ring DOES leak, it will show on the floor, not go down around the pipe.
Comment: ok if cutting off the old flange then the new flange can be cemented to the pipe.  what would be the difference between cementing to the old flange vs cementing to the pipe?
Comment: Cementing it to an unclean inside diameter of the pipe, unless you can get it clean. A smaller diameter pipe for the actual drain, but that should still work, since 3" drains are the norm too. The real trick will be to get the inside diameter of the old pipe to fit around the outside diameter of the new pipe. I have done that with some success by using a 3" pipe with a coupler to act as a filler. The Joint MUST be tight fitting before gluing up or it will leak. DO NOT let the lettering on the sides of the coupler fool you into thinking you have a tight fit, If it even get you close....
Comment: I just realized there are flanges that fit into the interior diameter of the waste pipe. Pray that it will be tall enough to get your height you need.
Answer: You probably wanted something like what's pictured below.  It's made for cast iron pipe.  You drop it into the old pipe and tighten the internal screws to expand a rubber gasket.  This would guarantee a proper seal:

How you get the required mounting screws to work is up to you.  A plumber will have an internal pipe cutter, and she could cut the pipe, remove the old flange and drop one of these bad boys in its place.


Keeping goats from eating my plants

Question: I have a couple of goats I like to let run around my yard, problem is I have a few flowering plants out there too. The goats seem to target these heavily, I was wondering if there was some way to keep them from eating specific plants/groups of plants? They get all the free choice hay they want at their pen, so I know they're not starving.
Comment: I know goats are terrors for eating just about anything. One thing I know from my keeping my own livestock (though not goats) is that they like variety so just providing abundant tasty high quality hay is unlikely to ever keep them from exploring and even stripping other plants.
Comment: We tried to spray the plants with olive oil and cayenne pepper. It stopped em for a while. Like one second. They licked their lips and continued to eat. Oh well.
Comment: After watching  a goat eat a rag with car polish on it ; I doubt you have a chance.
Answer: Goats are browsers rather than grazers. That means that they prefer to eat woody shoots and stems of trees and shrubs (including your flowering plants) over grasses like hay. In this regard goats are more closely related to deer than to other domestic livestock like sheep or cattle, which are both grazers.
Like Tea Drinker mentioned they also like variety and will try pretty much anything if left to their own devices.
Comment: They're smart too!  They know to sneak back inside the fence just before you come back home.
Answer: Some goats are immune to electric fences.  I usually chase my goats out of the roses and various other plants with a stick. I have also resorted to waving my arms and rather ugly words.  I never touch them (well today I whacked the female for the first time) she had just finished off the last of the newly potted plants, in our enclosed anti-goat terrace.  They are lovely but the male goat pisses on the children's toys.  Yes, he is a goat, not a dog.  I have a 3 foot wooden fence and it is just something fun to jump over.  I also have a four foot electric fence that deters all other animals but goats.
My advice is to love your goats more than the plants because they will eat all your favorites, perch on everything like parrots, bleat early in the morning and their mating habits are not good morning material.
Answer: Sure: a 6-foot high fence.  Preferably with some electrification.
Given that goats will, on occasion, eat things as diverse as cardboard, newspaper, clothing and cat food, nothing you can spray on your plants is going to dissuade them.
Comment: You don't need electric fences that high.  3 feet will do.  We got our poultry and sheep fencing from Premier 1 - (not affiliated - just a customer of 3 years)
Answer: Good quality electric fence will do the trick.  It only needs to be 32 or 36 inches high.  It will also keep them from standing on your car.
Answer: We have goats on our farm.  Larger ones and small, Dwarf Nigerian ones.  One things is true about animals in a fence, they'll test the fences.  Horse, donkey, pig, goat... they'll test the fence and if the fence has a weakness, they'll likely find it.
We use goat/sheep fence to keep the goats within their fields.  This is a woven wire fence with 4" x 4" openings.  The woven wire is more expensive than the welded wire but it is considerably more durable.  Our goat fence is 4' high and that is certainly sufficient to contain a goat as long as there is nothing nearby upon which it can climb.  We utilize electric tape to encourage the larger animals to respect the fence (a horse can put tremendous pressure on fence posts) but the goats tend to be happy with their pasture.
To keep them off of a particular area, I'd think step-in posts with electric netting and a sufficiently powerful solar charger would be a good choice.
Answer: Try applying fresh cow dung or goat dung on leaves. The stinky odor keeps the goats away from them. Check the type of plant before spraying it. Sometimes it might harm the leaves.
Comment: And don't even *think* about that practise in your veggie patch!
Answer: A tea of goat dung has been use since before I was a kid that was 65 years ago and my grandmother told me about that and she passed at 87 abut 40 yrs ago they lived and didn't get diseased and the tea helps the plant to thrive. secondly after raising a herd of over a hundred goats I've found that a 39 inch woven wire fence with two strands of barbed wire with a strand of electric wire between them and one half way up on the woven wire does good also if you can rotate them bi-daily and into areas that has some brush that seems to entertain them and they aren't so apt to want to got out as quick.
Comment: I strongly disagree with the use of barbed wire for animal enclosures. It is not only cruel (because animals can also get tangled by accident, e.g. when frightened or startled), but also can cause nasty infected wounds on the animals. The use of uncomposted dung directly on plants is risky as well (parasites, pathogens!), that your grandmother suffered no ill effects does not make the practise safe.
Answer: Goats can absolutely be trained not to eat your garden! Just blow a puff of air at their face for a small infraction and if you really want to deter them from an area just spray them briefly with a hose. I guarantee they'll learn real quick what you don't want them to eat. I don't even have to fence in my goat. I started early taking him on walks when he was 3 months old and now fences are irrelevant. He knows where I am, his home is and so it doesn't matter if he's in the front yard/back yard. That boy is almost never out of my sight and if he does step out of sight just call his name and he comes running.
Answer: Dog poop does the trick for my sheep. You have to replace the bags regularly or it will contaminate the soil. It does not look pretty but it will do the job.
Comment: That's a bad idea because of the risk of disease/parasite contamination.
Answer: Shooting in the air will work for about 1 hr then they are back again.  I can't afford the chain link fence (don't think that would keep them out) and definitely would not put up a electric fence around my yard with kids around.
Comment: this is a comment, not an answer

Keeping goats from eating my plants


How to properly initiate or use karate( any style that uses the beginning blocks since they're actually grappling techniques)grappling techniques

Question: Not a lot of people know the truth about karate but it is actually a grappling martial art. If you study the beginning blocks you will realise this and you can see it on karate by jessies website. They aren't taught so much because some dojo have become mcdojos and watered karate which is bad. Now I'm wondering how you would initiate these grading techniques.
Comment: I hope you can find some good sources.  The grappling moves are often one of the first things lost in a lot of striking arts, however it usually "hides" in forms or as different moves.  You might have some better options looking at some grappling arts and looking for crossover movements - like a classic standing armbar/break is identical to what is often shown as an inside block with the forearm.
Answer:
but it is actually a grappling martial art

This is not the case at all. Karate was always a complete martial art. Most martial arts began this way, the modern striking/grappling dichotomy is a false one related to sporting rule sets.
i.e. It makes use of all techniques, striking, grappling and everything else that works, including methods that would be considered very much "unsporting".
Yes the katas are chock full of grappling methods; arm locks, wrist locks, chokes, throws, takedowns, even leg locks, eye gouging and pretty much anything else you can think of.
Consider how fluid and fast a punch is. It takes about 1/6 of a second to perform a punch and retract the punching arm. It's faster than normal human reaction times. Now consider how static kata are. Kata don't lend themselves to very fast fluid movement. They don't represent it well at all, and modern striking combat sports like kickboxing or boxing don't make use of kata for that reason. At most they run a couple of combinations together. The methods are simple and don't really need to be recorded in this way.
Now look at grappling techniques. They are far slower, more complex and it's important that the configuration between the attacker and defender; relative position of body, arms, legs etc is recorded in order to execute the techniques correctly. This lends itself to kata or forms rather well though with solo forms only half of the needed information is there.
Striking methods are the most common, they are the easiest to learn, but they are only the beginning. Schools which stop at this point are teaching only maybe about 1/3 of what karate is in toto.
How kata are structured:
http://katapedia.org/wiki/Structure_of_kata
Some tools for analysing the real meaning of kata sequences:
http://katapedia.org/wiki/Bunkai_%28Analysis%29
What Kenwa Mabuni said about the meaning of angles within kata:
http://katapedia.org/wiki/Kenwa_Mabuni
Misc other info:
http://katapedia.org/wiki/Other_rules
And an example of the meaning of the first movements of Pinan Shodan / Heian Nidan:
http://katapedia.org/wiki/Pinan_Shodan_moves_1-3_application_one
i.e. The opening movements of the kata are often described as a double block followed by two strikes. An explanation that makes little sense.
The double block is a figure 4 type arm lock, and the two "strikes" are you dislocating the shoulder of the opponent, using his elbow as a lever. The double strikes are really a push/pull.
How to make use of the grappling methods is dependent on the situation, that's what you need to train, and practise for. That is what kumite is for. In terms of kata, it differs for each kata and often for each sequence. Itosu's kata the Pinan/Heian katas very commonly uses a wrist or forearm grab as the entrance technique for the sequences. He obviously thought it was a reasonable way to begin each drill. And when you look at real violence, you find that untrained attackers very often grab before their main attack. Grab and hit, grab and stab.
e.g. grabbing the shirt with the left hand before punching with the right hand...
Shuto uke was designed for exactly this situation. The upstroke of shuto, catches the elbow of the grabbing arm, the down/out stroke rotates uke away from you and puts him in an arm lock. The other hand traps uke's grabbing hand. The result is that the attacker's strike is blocked, though not as is commonly taught.
Comment: @Sardathrion https://www.reddit.com/r/karate/comments/48ag1w/discovering_kata_against_an_mma_cage/d0jwcps
Comment: Your link to Pinan Shodan application contains no text.
Comment: Is katapedia your own site?
Comment: @TheWudangKid - fixed link .
Comment: @Sardathrion - I created the site, but it's an open access wiki.
Answer: I studied shotokan for 10 years, I got my 1st Dan under Sensei Enoeda. So defo not under a 'mcdojo' And yes, there is a lot of stuff 'hidden' in kata (pressure points, locks Etc.).
It doesn't really matter though, as you don't directly train in grappling in karate, a beginner in judo will easily take apart a 1st Dan under judo rules.
Saying that, there are plenty of other styles of karate that may focus on grappling. But in reality, you want to learn how to grapple, karate is not the art.
Comment: The grappling found in karate is mostly optimized for enabling other attacks, such as strikes to the bones and joints (to break or dislocate them), trapping and joint locks to control your opponent while still hitting him yourself, etc. If "karate is a grappling art", it is one that specializes in the trapping aspect of grappling as an enabling mechanism, but only superficially covers throws or ground fighting. Of course it's gonna lose in a judo competition against opponents that specialize in that sort of combat!
Comment: +1 exactly, my point is that if someone wants to learn to grapple, karate won't cut it for you.
Comment: However it was originally designed, the grappling that karate teaches simply does not appear effective in mixed martial competition. Judo/BJJ have evolved quite a bit in the last century, and are much better suited to teach those techniques.
Comment: But karate was originally a grappling art, or maybe a better description would be an art that teaches arm locks etc
Comment: Given that all the kihon technqiues come from kata, and within the katas most of the techniques are grappling related. Doesn't it behoof all karateka to practice the techniques? Otherwise what's the point? More to the point Funakoshi and all the other old masters included the grappling methods as well as striking.
Answer: The trick is that the initiating move doesn't actually have to be a formal "move" - a simple swipe or parry on an incoming punch is all you need to start execution of the grappling bunkai in a technique.
Take soto uke for example ("inside block" mentioned by Bankuei). The non-blocking arm is extended at the start of the move, but this is not the catch. Wikipedia tells us:

This represents grabbing the attacker's arm

I would emphatically state that is so simplistic it is almost wrong - you cannot just grab the opponents arm and pull it into the path of the block in the fashion described, especially without changing the position of your body. If you don't believe me, try it with a non compliant training partner. Then try it on someone swinging punches at your head (rather than your midsection).
Instead, what that part of the move is telling you is what to do once you have got hold of the opponent. IOW, it doesn't teach you how to grab, it teaches you what to do once you've made the grab.
To make the grab, start with the opponent swinging a haymaker/round punch at your head with their right hand. Then:

parry it with your right palm from the outside and guide the punch across you
continue the parry by bring your left palm up and along the inside of your right forearm (which is currently facing outwards), the left palm should continue the parry once the punch crosses your center line and the right palm should then disengage
once the left palm has parried the punch sufficiently past your center line you should grasp the opponents lower forearm or their wrist as you continue the movement
you now have the grab.
keep the momentum going which will pull the opponent further off balance and further extend their arm
while you do this you should then start to pivot and bring the right forearm round as the soto uke into the back of the opponents punching arm (there are several juicy locations you can strike, don't strike the point of the elbow unless their arm is totally straight).

The double handed parry I detail above is very similar to the "wax on, wax off" move as popularized by the original Karate Kid movie (seriously, no joking), but it is done with soft hands so that you don't stop the opponents momentum. It is very similar to what is described as hiki uke at the 3:40 mark of this video (but you want to keep it closer and softer than this guy, don't try and execute the parry several feet from your body).
These blocks are all at their optimum effectiveness when executed as part of a grapple. Please don't practice this particular block in this fashion - you will get hit. Soto uke was never developed to be used in this way - you would have to have the front punch of an old man to get caught by that block (the punch is straight, the block is executed in a considerably longer and rounder way, making it a lot slower. Additionally the defender is stepping to the inside - straight into the range and path of the attackers other limbs).
This video shows some better applications, these guys are already in a grapple when they use the block. Note the starting point of the blocking hand of the karate demonstrator - it deviates considerably from what would be taught in regular line work or kata. This is because the technical form can describe or suggest many things, but when you go to use it in a real situation you are concentrating on one of the possible options. This means, for example, that the blocking hand doesn't have to start from close to the ear when you use the block on a real attack, but you should still execute it that way when practicing line work, combinations or kata.
Comment: I'm somewhat confused
Comment: @Silverbackgorrila About what, specifically?
Comment: I'm somewhat skeptical of soto-uke. The only place I can find it is in Passai - Bassai Dai. It isn't in any of the earlier katas that quite literally all of the other kihon originates from. In Passai, it's simply a component of a leg scoop and throw. So not really a block, or even a lock as such.
Comment: @css1971 Yeah, soto uke (and some other basic "blocks") are in few katas. It makes for a simple and easy to communicate/understand example though.
Answer: Karate acknowledges and differentiates hard and soft techniques, both requiring slightly different training, kata, style, and mindsets in general. Many grapling techniques in karate initiate from a soft state as a reception (i.e. using the force of the opponent) and then finalize with a hard technique, therefore both states complement each other. You can see the bunkai of many goju-ryu Kata (Seyunchin and Kururunfa are good examples).
Answer: It is my understanding that you'd have to search very far and wide to find a karate school that emphasizes the grappling portions of the karate lexicon. Even quality mainstream karate is kicking and punching with barely any deviation.
If you seek application of grappling moves: either find a karate school that also offers a dedicated grappling art like Brazilian Jiu Jitsu or Judo, or also take grappling from another school concurrent with your karate. As Matt suggested above, learning grappling from a karate teacher is very unlikely to get you to a level you'd reach by learning grappling from a grappling teacher.
I'd recommend BJJ over Judo if you want to learn grappling. Judo schools (in my experience) over-emphasize throwing to the detriment of ground work and joint locks. BJJ tends to focus on groundwork, but includes some throwing and generally teaches a sense of your opponent through touch that strikers tend to lack.
Chin Na is more likely to get to the meat of joint attacks, in my experience. Aikido is pretty good for joint attacks, and I am sure there are other less popular arts that could also fit the bill. If you want great grappling and joint locks, just find a Chin Na teacher.
I started with karate. I had to un-learn a lot of karate as I advanced. If I were doing it all again, I would do BJJ first to gain a strong foundation in non-striking consciousness.
(It goes without saying every school/teacher might offer something outside the norm)
Comment: Do most karate schools just teach striking only today


List entries which have no category assigned

Question: Anyone know how to do this?
Obviously I can pass in a category ID into the channel loop to get entries within that specific category. But I'd like to get a list of all entries that don't currently have any categories assigned to them.
This purely requried as a reference, I've done a massive import and need to generate a working list so my editoiral guys can go in and categorise those entries which aren't assigned to anything.
Answer: Something like this maybe?
{exp:channel:entries category_group="not 1|2|3|4"}
Comment: Damnit, that's so obvious. Thanks!


Will mixing methyl 2-cyanoacrylate and cellulose make the cellulose harden quickly?

Question: The other day I was gluing together cotton fabric with methyl 2-cyanoacrylate (superglue) and the fabric started heating up and then eventually began smoking. I have been working on making a 2-part plastic-like substance for personal reasons for some time now, and I know that ionic liquids pull the individual polymer chains that make cellulose apart and that once they are separated they go into solution easily. This in mind, could I get the dissoluted cellulose and add superglue to create a cheap plastic-like material?
Answer: The working principle of super glue, based on 2-cyano acrylate, is an anionic polymerisation reaction which in principle triggered by any nucleophile.  Water conveniently may be such a nucleophile (the basic anion of water, hydroxyde $\ce{OH^-}$ were even better) which is why the container's mouth originally is not only closed by a cap, but by a thin metal plate.
Cotton consists mainly of cellulose, and cellulose itself

(source)
posesses many hydroxyl groups which like water may trigger the polymerisation.  Since there are so many that are easily accessible, the process is very fast, and proceeds under liberation of much heat (i.e., an exothermic reaction).  Because of this and because the acrylate may generate a strong 3D polymer, one should not wear cloths made of cotton-based fabric, nor gloves of such.
While it is new for me to learn that ionic liquids are able to dissolve cellulose, it might be that such an unmoderated polymerisation "runs away"; i.e. already proceeds at a high rate and, because of the liberated heat and high local concentration of the nucleophiles and monomers, will become even faster, eventually is no longer manageable.  Beside potential splatter of liquid-as-such (thermal threat), the polymerisation reactions could proceed further even on and with the skin of an operator (chemical threat) if not protected properly.  Be warned, as each of the two are potentially dangerous, in addition to the potential hazard that working with ionic liquids, and chemicals in general, represent.
Wikipedia hints to this potentially relevant Critical Review doi 10.1039/C2CS15311D in Chem. Soc. Rev., 2012, 41, 1519-1537.


When translating an article into English, how do I quote the author's quotations of translated versions of English works?

Question: The article which I am translating into English quotes extensively from translated versions of works by English authors (e.g. a Spanish translated version of Philip Pettit's 'Republicanism'). As the translator, do I translate these quotations into English myself, or do I need to find Pettit's original English words? I'm not sure, because the latter would mean quoting from a text (the original, English version of 'Republicanism') which the author of the article I am translating did not read... In which case do I simply do the former but make very clear in the in-text references that I am quoting from a translation?
Answer: In my research I need to cite a work by a Russian author, Gnedenko, say, who, for reasons unknown to me, published in French, in an American journal. There being no published translations of the original French (if he really did write in French, which I doubt), I have translated the French into English. When I need to quote I will use my words followed by  "(Gnedenko [reference] - my translation)".
In practice, in my subject, statistics, Gnedenko's exact words matter much less than his ideas, and if I wished to cite another author who studied Gnedenko in translation it would not matter much which language that author had read the paper in.
If in your subject it really matters what language other writers have read a paper in, then you have no alternative but to quote those words, in whatever language was used. You may provide your own translation, identified as such.
The point is that you must leave no doubt in your readers' minds as to where the words you cite came from.

When translating an article into English, how do I quote the author’s quotations of translated versions of English works?


How to ensure Wine does not auto run .exe files?

Question: I want to install Wine only for running a program, but I don't want to open any other Windows file (for security). Is it possible to ensure Wine does not execute .exe files automatically? Thank you.
Comment: Why do you focus on Windows executables? Any executable file or executable shell script can be run with `/path/to/executable` or `./executable`. Linux executables aren't magically more secure than Windows executables, especially when the latter run on Wine!
Answer: When you install the wine package, it registers itself so that .exe files, if run from the command line, will "auto run via wine" if they match a specific signature and have executable bit set (like via chmod +x).
To prevent accidental direct execution of exes from console like
/path/to/program.exe

you can setup binfmt_misc kernel module with the following command:
sudo update-binfmts --disable wine

This will disable support for direct execution of files with magic MZ.
CAVEAT: this appears to be undone on restart or Wine upgrade.
If you really want to get rid of it (until wine upgrade!), run
 sudo update-binfmts --package wine --remove wine /usr/bin/wine

Comment: This should be the accepted answer
Answer: As far as I know, wine does NOT execute .exe files by default, based on my experience so far with Wine on Ubuntu 13.04.
I'm not sure if previous Ubuntu/Wine versions allowed it automatically run executables, but at least you can be fairly certain that that is not currently the case.
Comment: With 12.10 it certainly does...is there any way to disable it though?
Comment: With 13.04 it also (for me anyway) wine runs an exe files if you double click them in unity file explorer, and also if you run them in the command line like "./a.exe" it automatically invokes wine to run it for you.
Answer: Wine does not run files automatically (poor wording choice on your part).
However, if you want exe files to open with something else by default, you need to change the associated program for exe files to something other than Wine (you can do this from the properties window in Nautilus).
To run your program, you can create a .desktop file or simply use "Open With" from the context menu.
Comment: Ok looks like the binfmt-support in question can be disabled via `sudo update-binfmts --disable wine` (you can see its list via `update-binfmts --display`) thanks for the tip. Finally it doesn't auto run my console exe's, which can be problematic when cross compiling.
Comment: That occurs because wine is set (by binformat support) to run exes when you attempt to execute them. I don't know if that can be disabled without removing wine though. BTW, your question is vague if that is what you mean.
Comment: I wouldn't believe it unless I'd seen it, but if I open a console and cross compile "a.exe" then run it, like $ ./a.exe voila, wine appears and runs it for me.  It is bizarre...
Comment: `update-binfmts` needs the `binfmt-support` package, not installed by default https://packages.debian.org/pt-br/sid/binfmt-support
Answer:
Wine doesn't associate with .exe files by default on most systems, and depending on your installation, it 'may'.
The EASIEST way for you to do this would be to install the program Ubuntu Tweak, this can be downloaded from here: Ubuntu Tweak Download Instructions
Once you have it downloaded you simply open it up, change to Admins tab and then under System choose File Type Manager. Once in here select the file category Text and using shift-click and/or control-click select all of the file types you want, then click Edit on the bottom right.
This will allow you to multi-set the mimetype opener for all of the files.
See screen:

I believe that this is what you need in addition to the above point: How to prevent Wine from adding file associations?

Ref: how can I change file association globally?
Comment: Nice!  I think this does work for the file explorer so that double clicking an .exe file doesn't automatically run it, which is nice, thanks!
Comment: @rogerdpack If it works for you, please accept the answer by clicking the green 'tick' icon so that those who visit the Q in future know what to try first. Thanks. :-)
Comment: Unfortunately I am not the original asker of the question...
Answer: Wine doesn't run .exe files by default unless you add such an association rule. If you did, remove it from Nautilus properties.
Answer: One option is to rename your wine executable, ex:
 sudo mv /usr/bin/wine /usr/bin/wine.disabled

or the like.  Just remember to remove that or rename it if you remove the wine package :)
Sometimes configure scripts will still use "wine64" if it's present (and update-binfmts might not be enough of a work around), so you may need/want to rename that as well.
Answer: I found the best way in the man page for binfmt.d.
To override a rule, create a symlink in /etc/binfmt.d to /dev/null with the same name.
In the case of wine, the package file is at /usr/lib/binfmt.d/wine.conf and can be overridden with
sudo ln -s /dev/null /etc/binfmt.d/wine.conf

This change is permanent and will survive reboots and wine updates.
Comment: Yes that's probably right, but a "sudo" in front of it still would not hurt, so I don't get the "musn't" part.
Apart from that, my comment seems to have disappeared, it was just saying to add sudo.
Comment: I have modified it... relax.


Would it be accurate to say that the economies of most of the countries are capitalistic?

Question: What is the proportion of countries that are capitalistic? What is the proportion of the planet's population who live in such countries? How is this, (somewhat subjective?)
Answer: A nice way to check this is by looking at the economic freedom index
As we can see, this is a scale, there is no perfect capitalistic country and most of the countries are not very free economically


Merging layers into one- QGIS

Question: I have numerous population layers for the Baltic Sea. In the attribute table of each layer, I have population densities, name of towns etc, all the same geometry (points).
I'd like to merge the layers together so that I could have all the population densities of the Baltic inside one layer. I tried to used the "merge vector layers" tool, but when I do so, the information gets all mixed up in the output attribute table. For example, the first 11 columns are linked to Germany (picture 1), but then, the next columns show only zeros and no data (picture 2)

Is there a way to make all this tidier?
Comment: Some more information on your current data would be helpful, e.g. how many layers, if they overlap, etc.
Comment: I have 12 layers, same coordinate system, and they do not overlap. Each country has population points representing towns, villages and cities. Those points contain population densities, employment rates etc. My aim is to merge them all so that I can visually represent the differences between countries, in terms of densities, employment rate etc.
Answer: The issue is that the fields have different names in each layer, so QGIS creates a separate set of fields for each layer.
Slow method: rename the fields in the original layers
You could fix the issue by renaming the fields in the original layers (eg, change "SwedenPo_1" and "GermanyP_1" to "Field_1" or "CountryName"). To do this, open the layer properties, go to source fields, turn on layer editing, double-click on the name of each field and change it. This is pretty slow, because you have to repeat for each field in every layer.

Fast method: change the names in the combined layer
A much faster method is to change the names in the combined layer, using the Field Calculator. The individual steps are a bit longer, but you only have to do it once for each field.

For text columns, use the concat() and replace() functions. This will concatenate all the field values together into one string, then remove any zeros.
 replace( concat("SwedenPo_2", "GermanyPo_2", ...),'0','')

For numerical columns, use the max() function. This will choose the largest value from the list of values, so if only one field has a value greater than 0 it will choose that one.
max("SwedenPo_4", "GermanyPo_4", ...)

Alternatively, the sum() function would work just as well as max() for this dataset.
Repeat for all fields. Delete the original fields.
Answer: Method 1: Try using a virtual and SQL layer and construct: SELECT * from name_table1 UNION ALL SELECT * from name_table2 ...SELECT * from name_table12;
Method 2: Create a new point layer and copy 12 source layers into it.
1) Create a new point layer *.shp tools "layer" - "Create layer" - " Create shape-file..."Give it a name. 2) make your layer active, run "pencil" i.e. allow to edit it. 3) Now activate your first point the source layer and the tool "Select objects by area or click" select the objects, then make active your new layer and run the tool "edit"-"Insert objects" and so another 11 times :-)...Finish editing the new merged layer and see the result...
Comment: in the new layer, create a structure corresponding to your source data in the window using "add field to list"...
Comment: the structure of your 12 tables must be identical, otherwise you will lose the fields ...
Comment: Thanks for your input. However I am unsure of how to conduct method 2. Could you give me additional info?
Comment: The process seems to be working, but I have only one field that is being copied in the attribute table (population densities field). My remaining 7 fields do not appear in the new shapefile. These fields (pop densities, employment rates etc) are joined with an excel spreadsheet for each country (i.e each country has it's own spreadsheet). Could that represent an issue?
Answer: Straightforward way: Name the columns in each shapefile the same, then merge them.
Clumbersome way: In your merged file, create new columns which you fill with the corresponding atrributes of the countries using if-functions.

Merging layers into one- QGIS


How to fade a line out in photoshop

Question: I have 1 RGB layer; the background. Its background is white. There is a solid line on this image. I wish to fade its left end out to white. How can I do this please?
Answer:
Make sure your line is on it's own layer.
"Add Layer Mask" to the layer
Select the gradient tool, make sure it fades from black to white
Click and drag the gradient on the layer mask

This will fade the line to whatever is behind it, as it makes it transparent.
Comment: This is a more powerful option as it gives you the ability to change the background colour at a later time without having to redo anything else
Comment: Oh, what the heck, +1. But my method's good for programs with no [native] support for masks (not mentioning any names, *Paint.NET*, ahem).
Answer: If you are drawing the line, use the gradient tool, and make your right end the color and the left end white.
If you are editing someone else's work, try this:

Use the Selection tool and draw a
marquee around the part you want to
fade.
Go into Quick Mask. It should be on Mask is Selected Area.
Select the Gradient tool.
Draw gradients until you like how it
fades. That is, until you like how the gradient of the Quick Mask color covers your line.
Exit Quick Mask.
Layer → Layer Mask → Hide
Selection.

If you don't like how it looks, back up in your History to the Quick Mask step and repeat as needed.
Answer: Quickly, young hero:

Create a new layer
Draw a line
Select the area around it (the "background")
Invert Selection
Select your gradient tool
Make the primary color the color you want, and the secondary color entirely transparent (Alpha?)
Delete the contents of your selection (delete key?), and draw the gradient from one corner to the other corner of the line
Merge layer into your main layer (or leave it alone, if you want)

May your sword stay sharp!
Answer: Just use a rub of the eraser with a 0 hardness.
Answer: Ways:

Layer mask. (Then i merge it cause i dont want huge layers to be hanging out)
Rasterize>HugeSoftFadingBrushEraser.
Gradient Layer effect//clippingLayer.

How to fade a line out in photoshop


Exploding Kittens- Slap to get out of multiple turns

Question: What I'm trying to find out is:

If you get slapped (let's say triple),
And you play something in-between (you don't currently have a slap in your hand),
e.g. an alter the future and put another slap on top,

Can you now play that slap to push the rest of your turns on to another player?
(now that the alter is between it no longer adds onto the previous slap).
Does that negate both your remaining turns and push the complete slap onto your chosen opponent? or
Do you remove one of those for the 3rd turn? or
Can you not do it at all?
Answer: You have been slapped thrice, so you now have 3 turns to complete.
If you have a slap card as return, you can shift all to another player. But if you don't have a slap card, you can not return.
But if you draw a slap card in an other turn, you can transfer all the remaining turns to another player. see The rules.

Double slap
End your turn without drawing a card and force any other  player to
take 2 turns in a row. This is not the same as drawing 2 cards in a
row! The target of this card should take their first turn (play cards
and/or draw). When their turn is over, it's their turn again. If the
targeted player plays a Slap Card in return, they pick a player to
take ALL remaining turns (4 turns, then 6, and  so on). Play always
continues from the targeted player. If you draw and defuse an
Exploding Kitten during a series  of turns, you must continue taking
your remaining turns.

Example
You are targetted with a tripple slap and you have no slap to return. So you are forced to take the turn(s).

Turn 1, you draw a slap. You now have 2 turns to complete.
Turn 2, you play the slap. You target another player that gets the 2 turns of the card + your remaining turns (2nd and 3rd) for a total of 4.


How do orbital spacecraft calculate reentry?

Question: For a given spacecraft, in a given LEO orbit, assuming you have all the required data, how do you choose the needed burnout speed and timing (or position in orbit), in order to reach a certain point on earth with a ballistic trajectory?
Comment: "How do orbital spacecraft calculate reentry?" Very carefully ;-)
Comment: @uhoh: Well, Voskhod 2 crew did it less carefully but rather urgently, with a marker over the capsule window.
Comment: What are the equations you would need calculated using sensor data to correct in real time :)? Yes- Im actually asking. A list of some used on actual reentry vehicles to maintain trajectory would make a cool answer.
Answer: In reality one re-entry burn would never suffice to reach a specific point. The most you can aim for is within a certain area (e.g. splash down in the pacific) but the uncertainties in your actual impact position will be very large. Either you have to regularly perform corrective manoeuvres or you make sure your spacecraft just burns up and never reaches the ground.
Now assuming you have a VERY accurate model of the atmosphere (including wind) and precise knowledge of the attitude of your satellite, the process of determining the required burn duration and direction is purely numerical optimization. The equations of motion of a satellite re-entering are very non-linear and there is no analytical solution.
In reality it will be a combination of numerical optimization to calculate the re-entry burn and then a sophisticated control system to keep the satellite as close to the reference trajectory as possible.
Edit: In case of spaceplanes this is not valid as they can just glide towards the spot they want to go to and have much more control over their trajectory.
Comment: @OrganicMarble, hmm yeah that's correct! I'll add to my answer that it's not valid for spaceplanes.
Comment: Shuttle did one re-entry burn and managed to land precisely on a runway. Not ballistic though.
Comment: The last 2 Mercury orbital flights, after working out various issues in earlier flights, both got within 5 miles of their target points with no active steering after retrofire. Earlier flights were off the mark due to human error (Carpenter's MA-7 flight) and incorrect calculations (Glenn's MA-6).
Answer: Not really a scientific answer, but it should help with the question:
An uncontrolled re-entry is mostly unpredictable. If a satellite on a low earth orbit experiences drag from atmospheric friction, predicting re-entry is almost impossible. The drag depends on tons of factors, such as sun activity and weather, and changes constantly. Since the satellite orbits around the whole earth once every ~90 minutes, if you are wrong by 45 minutes you're already on the other side of the planet (plus some shift from the earth's rotation). The closer you get the better you can calculate, often based on live measurements. That's why it's impossible to know where a decaying satellite will hit even the day before it crashes.
Controlled is a bit different. Assuming you don't have a strongly elliptic orbit, if you burn retrograde (i.e. against the orbital flight direction - basically "braking"), you create a perigee (i.e. lowest point in orbit) on the exact other side of the object you are orbiting. With a strong enough retrograde burn, you can lower that point deep into the atmosphere or into the planet. Time it right and you can create a point of re-entry by your choosing - it's not very precise, but you can at least reliably hit a specific area of an ocean of your choosing or, say, siberia.
Space Shuttles do that and add control over atmospheric flight to the mix, which gives them enough control to land on a runway.
Answer: The way spacecraft do this is via one reentry burn using the best estimates of the atmosphere, and doing some slight corrections to the path while reentering. The best example of this is the Space Shuttle, which could precisely land due to the aerodynamic surfaces, however, every spacecraft has some ability to steer itself inside the atmosphere. It is very rare to have a purely "Ballistic reentry", however, they were sometimes done, particularly in the early days of the space program.
Basically orienting the capsule will allow it to slightly change its direction. Soyuz can land with a 28 km accuracy. See How does the landing accuracy of Dragon (under parachutes) compare to Soyuz? for some comparisons to Dragon, and some raw values.
Comment: There was a Soyuz ballistic re-entry in 2008. I guess that's early days.
Comment: There was one in 2018 too, for the abort. I said it is rare, but was more common in the early days of the space program.
Comment: 2018 technically wasn't a reentry since they didn't bust the Karman line.
Comment: It didn't? Huh, I thought it had. Well, close enough.


Is there any canonical reference to the fate of the Blue Wizards: Alatar and Pallando?

Question: All I've ever been able to find is that they arrived in Middle-earth and left to go do something outside of the scope of the story. Has anyone ever found any additional information?
Comment: I remember reading a poem by Tolkien which says Gandalf was the only wizard that remained true to his original quest & was the only wizard that returned to Valinor
Answer: In a letter written during the writing of The Unfinished Tales, in which Tolkien first named Alatar and Pallando, also called Morinehtar and Rómestámo, he wrote concerning them:

I think they went as emissaries to distant regions, East and South,
far out of Númenórean range: missionaries to enemy-occupied lands, as it were. What success they had I do not know; but I fear that they failed, as Saruman did, though doubtless in different ways; and I suspect they were founders or beginners of secret cults and 'magic' traditions that outlasted the fall of Sauron.

However, in The Peoples of Middle-earth, written by Tolkien in the last years of his life, he said that the Blue Wizards had succeeded in turning the tides of conflict in the East during the Second and Third Ages. Whether this is a revision of what he previously wrote, or whether they were initially successful and then fell, is not known.
The quote from The Peoples of Middle-earth is as follows:

The other two are only known to (have) exist(ed) [sic] by Saruman, Gandalf, and Radagast, and Saruman in his wrath mentioning five was letting out a piece of private information.
The 'other two' came much earlier, at the same time probably as Glorfindel, when matters became very dangerous in the Second Age. Glorfindel was sent to aid Elrond and was (though not yet said) pre-eminent in the war in Eriador. But the other two Istari were sent for a different purpose. Morinehtar and Rómestámo. Darkness-slayer and East-helper. Their task was to circumvent Sauron: to bring help to the few tribes of Men that had rebelled from Melkor-worship, to stir up rebellion ... and after his first fall to search out his hiding (in which they failed) and to cause [? dissension and disarray] among the dark East ... They must have had very great influence on the history of the Second Age and Third Age in weakening and disarraying the forces of East ... who would both in the Second Age and Third Age otherwise have ... outnumbered the West.
Comment: Thank you SO MUCH for the source of the notion that Blue Wizards had succeeded in their mission, I had read it but never knew where it had come from.
Comment: @NathanC.Tresch I've found a quote, so I'm going to add that to my answer.
Comment: Nice, I never knew of the HoME version.
Answer: In MERP, the Middle-earth Role Playing Game, the Blue Wizards were said to have both fallen in ways similar to Saruman. Alatar became addicted to Hunting and the other Blue Wizard, Pallando developed a fascination with death. While they started as friends, in the end they became rivals and may well have killed each other off.
Gandalf, the only one of the Wizards who first refused the mission, was in the end, the only one to stay true to it.
Comment: It actually was licensed, but frequently stepped beyond the bounds of that license.  Even so, nothing in it should be considered canonical.
Comment: Yeah MERP was licensed and everything right?
Answer: To add to Gabe's answer, there is another work (also written in the final year of Tolkien's life) which mentions the success of the Blue Wizards.
To be more specific, Tolkien says that the interference of the Blue Wizards was the reason that Sauron was not at sufficient strength to be able to resist the Númenor invasion.

Thus it was that though, as soon as [Sauron's] disguise was pierced and he was recognized as an enemy, he exerted all his time and strength to gathering and training armies, it took some ninety years before he felt ready to open war. And he misjudged this, as we see in his final defeat, when the great host of Minastir from Númenor landed in Middle-earth. His gathering of armies had not been unopposed, and his success had been much less than his hope. But this is a matter spoken of in notes on "The Five Wizards". He had powerful enemies behind his back, the East, and in the Southern lands to which he had not yet given sufficient thought.
The Nature of Middle-earth - "Note on the Delay of Gil-galad and the Númenóreans"

"The Five Wizards" is the name of the work where the passage Gabe quoted from The Peoples of Middle-earth comes from. Both writings date from the final year of Tolkien's life and together paint his final view on the fate of the blue wizards.
Answer: The cults that they may have started may have evolved as fictional pre histories of two major faiths: Budhism and Confucianism. Tolkien himself stated that the legendarium is a fictional prehistory to our world so therefore Confucius is obviously an inspiration for one of the two blue ones.
Comment: How is that obvious?
Comment: @Callum McDonald Are you telling that one of the Blue Wizards are the founder of Buddhism  ?


New MAP Sensor with wrong PID on scanner

Question: I've been chasing this problem on a 1997 Jeep Wrangler with a 2.5L L4 engine for some time. Symptoms are very rough idle with occasional backfires immediately after going into closed loop. Approx. 3 minutes into closed loop operation (coolant temp. @ 190*F) the engine smooths out and runs fine. Fuel trims are close to perfect as is timing during and after problem. The only PID reading bad is the MAP sensor. With key on/engine off MAP reading should be 24-25 inHg for my altitude. The PCM is telling me it's only 8 inHg! With engine ON @ idle, MAP is @ 3.0 inHg, Load @ 7%, TP @ 14.9. All of these scanner readings stay about the same throughout, whether engine is barely running during warm up or running fine after warm up. I cannot understand with skewed MAP readings, how this engine runs at all, much less running great after reaching coolant operating temp. This is my only clue... open loop runs fine, @ closed loop it barely runs, when coolant temp reaches approx. 190 it runs great again. I did replace the IAC valve/motor since I was not capable to test it. I've checked voltage and PID for the MAP sensor even after connecting a new signal wire to the PCM. Voltage is slightly off specs. but scanner measurement (inHg) is WAY off. I suspect the PCM is at fault, but would like other mechanics inputs. I've been a Mechanic over 40 years, but am not sure on my diagnosis. Something missing?
Answer: Finally solved! As I watched live readings on the scanner it showed that as soon as the ECM started getting info from the o2 sensor, going into closed loop, the engine would run bad until coolant temp. was 130*F or hotter. I replaced the o2 sensor, coolant temp. sensor and the thermostat for good measure. IT RAN FINE! I then replaced the ECT sensor with the old one and it STILL RAN FINE.
CONCLUSION: The upstream heated o2 sensor was not working correctly.
I had to dismiss all the info. the scanner was giving me, excepting that the ECM still has problems reporting correct PID's, but COULD STILL command the engine correctly. HONESTLY, replacing the o2 sensor was only an educated guess. Sometimes that's all we have. Obviously the scanner readings for the MAP sensor are incorrect, since it should not have EVER run good, relying on that information. The fuel trims too, showed almost perfect 0%, when does that ever happen? It was a true smoke screen. So, there was no guaranty any scanner readings were correct! Therefore, ignoring The upstream heated o2 sensor's excellent PID, was part of the solution. I did use two different scanners that agreed with one another to confirm.
Answer: Have you tried swapping the MAP sensor for a known good one?  Have you tried then disconnecting the battery and forgetting the ECU adaptives? Now for some thoughts on the matter...
In some ways it is even more odd that it runs well in open loop operation.  If the engine is calculating airflow using MAP, and there is no additional MAF sensor, then during the open loop idle this engine will be underestimating the calculated air flow into the engine (manifold pressure is underreading?) and will be putting in way less open loop fuel than is required.  It will only be when the lambda sensor starts to help run the system closed loop that the engine would realise that it is running too lean and attempt to richen up.
Having said all of the above, you mention that the load is about right, load is a function of airflow into the engine at a given speed (in this case idle) and so that coupled with a correct open loop idle.  Maybe the ECU has learnt a correction for dicky MAP?? very odd
I have had a few more thoughts, although the fuel adaptives may be correct, perhaps the air calculation adaptives are way off.  A misfire is suggestive of too much fuel, so when you switch from open loop to closed loop the ECU is overfuelling.  Can you see what the lambda voltage is doing?  It may be reading lean which is what happens when under severely rich misfire conditions.  As things warm up and misfire reduces perhaps the lambda comes good and then the fuelling is properly under control again.
I wonder how it would run if you ran the MAP sensor inside the engine bay (no vacuum).
Comment: I have tried 2 other MAP sensors w/same scanner readings as old one. I've had the battery and computer disconnected a couple times. It is a MAP only system, no MAF. I've tested MAF signal voltage using a vacuum pump with eng. off. The Min. & Max. "specs." were like .5 volts off, giving it smaller range. However what the PCM is reporting to the scanner in inHg for MAP is still way off. I even borrowed a friends scanner with the same results. Has the PCM indeed learned a correction?
Comment: NEW... started engine cold w/o2 disconnected. running in OL. Sitting still, had some hesitation with rev but idled OK. Plugged o2 sensor in again when coolant temp. reached 140*F. It idled and revved fine and soon reached 190*. MAP readings still skewed of course. Is coolant temp too low when going into closed loop? Is closed loop occurring too soon, before coolant has heated enough?   I did put the o2 sensor live readings to a graph. Waveforms from .12 to .86 volts steady. created a vacuum leak w/o any substantial change in range. Will recheck that, hard to pinpoint right waveform.
Comment: Is there a MIL associated with the MAP?
Comment: No MILs. I am about ready to replace the computer, since it does not report what the what the MAP is doing. When the Jeep was brought to me, I hooked up scanner to check live readings for ETC, IAT which both were same temp. (cold/ eng. off). But I noticed The MAP NOT reading Baro. Press. That was the beginning of this whole thing.
Comment: Have you got a pinout for the MAP sensor, I think they usually are 3 wires, 5v power, signal and ground.  Have you checked that the 5V is just that (do that by nicking the wires and measuring them when it is plugged into the vehicle)?  It may be some kind of grounding issue with the loom giving false readings?
Comment: Oh yah, 5.12V. What DID FOOL ME for a day, is 4.9 volts at the signal wire connector as well. BUT, after digging real deep I found there are 3 types of MAP sensors used. GM and most of the world that give a voltage input to the PCM thru the signal wire (analogue). FORD has a digital design with a frequency input to the computer.  THEN, CHRYSLER & HONDA that have a pull-down design MAP or "ceramic disc" design. This one has an output voltage (approx. 5V) from the computer to the map signal. The computer then reads a voltage drop as resistance increases in the MAP sensor.
Comment: Thank you mx5_craig for your help and your interest. I still might try leaving MAP sensor open in the engine bay, since you wondered, just for grins.


IE, FireFox LDAP issues

Question: We have an intranet site, with no known updates pushed to the server over the weekend. This morning, when attempting to validate with LDAP credentials via single sign on in IE, we receive Access Denied due to invalid credentials.   However, FireFox works fine.  And so does Chrome. This is the case for every system on our network.
Are there any known issues that would cause IE8 to stop authenticating with the correct user name and password on an intranet site, while FireFox would continue to work?  To our knowledge, nothing has changed.
What are some things we should check for?  What could possibly cause IE to suddenly stop working?
Answer: The LAN settings might be different for IE. Proxy settings could be set differently for IE.

IE, FireFox LDAP issues


What caused the roselle seedlings to emerge like this?

Question: I had planted some roselle seeds in a seed tray with an old mix of cocopeat, perlite, vermiculite and compost. The seeds were soaked in water before planting for some time.
Now after eight days or so they are sprouting but two of them have one seed leaf rotten. Two of them couldn't break the seed coat. I had washed the seed trays with laundry detergent since I hadn't any sterilising agent available, but it was washed off with water thoroughly.
What could be the cause of this and how do I avoid it since I need to plant new ones?
Answer: Hibiscus (in this case H. sabdariffa) likes slightly acid conditions. Cocopeat (coir pith) is slightly acidic and the vermiculite and perlite are neutral, so this leaves the compost and water you are using. Compost when properly aged and mixed is also acidic but can vary somewhat depending on ingredients. So this brings us to the water you are using - sometimes water can contain various things in solution such as salts, which, though fairly innocent regarding pH, can nevertheless interfere with the functioning of root hairs and could cause seeds to germinate reluctantly. So please see what you can find out about the water you are using, and the history of what was in the potting mix previously.
Another factor is the age of the seed; generally there are few seeds that will germinate effectively after 3-5 years storage unless they were given very special treatment.
Comment: The problem might be the water. It seems to be pretty hard here, with whitish chalk like deposits forming in buckets, etc. The seeds are 1.5 years old. Some of them have germinated well. Should I used filtered water?
Comment: Should I use* filtered water
Comment: Another thing is that the potting mix is not sterilised.
Comment: Also, these were in full sun always.
Comment: @Sam In that case (about the sun), they might be drying out too much too fast, if those containers are as small as I think they could be.


Do I need both a Croatian visa and a Schengen visa?

Question: I am an Indian national and travelling to France and Switzerland for 3 days each, and then to Croatia and Italy for 6 days each. My first destination is France and the last destination is Italy. Since I intend to spend the same time in Croatia and Italy, would I need to apply for a Croatian visa as well?
Answer: Croatia allows holders of still-valid Schengen visa with two or multiple entries to enter Croatia without applying for a Croatian visa.
You seem to imagine that this rule only applies if you would still have applied for the visa from a different Schengen country if Croatia had already been a Schengen member. But there is no such restriction.
When you apply for a visa for the Schengen part of your trip (from the Italian consulate, since that is your main destination within the area), document the entire trip. You should end up with at least a 2-entry visa with a duration-of-stay of 12 days or more, and that will be enough for you to enter Croatia between the two in-Schengen parts.
Comment: @Martian27: Croatia is _not in the Schengen area_, and is therefore not relevant to getting a Schengen visa., You can't **get** a Schengen visa from Croatia, so it would make no sense to say that your application for a Schengen visa should be filed with Croatia instead of with Italy.
Comment: @Martian27 the sentence you quote implies, and would be more accurate if it actually said, "your only destination or your main destination (longest duration of stay) *in the Schengen area* must be Italy."  If the sentence were literally true, it would be impossible for anyone to get a Schengen visa for a trip such as yours.
Comment: Makhlom : The information on the site is as follows "Please note that in order to apply for a travel visa at the Embassy of Italy, your only destination or your main destination (longest duration of stay) must be Italy. In the absence of a main destination (e.g. same duration of stay in two or more countries) you should apply at the country of first entry because your passport will show the entry stamp of your first destination only." I was wondering , since I will enter Croatia before Italy and I am staying for same duration, would the embassy insist on Croatian Visa?
Comment: Thanks I understood now. I will share my whole itinerary with the embassy at the time of application.
Comment: @HenningMakholm: I got VISA today. I agree with you that the information on the website needs to be modified.


Error entries in Watchdog duplicated dozen and hundreds of times

Question: I have seen that the table watchdog in my MySQL database is growing enormously, and after TRUNCATE, I see that for each visit to a single page, it generates hundreds of inserts, and when seeing them, they appear to repeat dozen and dozen of times. How can I trace where the error is, because I would bet this is a misconfiguration or something. I am worry that Drupal is making thousand of redirections, I have no other explanation, the pages load fast but the machine has a lot of RAM and hardware, so maybe I am loosing performance somewhere.
Answer: The best is to check what these entries are and try to fix them, e.g.:

when the warning/error comes from contrib module, consider searching for this specific error and find out what's the solution (sometimes it may be misconfigured module),
when warnings comes from your custom modules or themes, consider fixing it manually.

If you think you cannot fix the source of the issues, you should introduce caching mechanism to your site such as:

Redis/Memcached which will limit enormous number of inserts into cache tables.
Varnish to cache the front end pages.

or limit the entries by:

limiting watchdog entries to warnings only (ignoring PHP notices) or silence all of them.
disabling dblog (database logging) module completely and switch to syslog logging instead.

See also: How do you improve Drupal performance?


Can Raspberry Pi B+ run Kodi efficiently?

Question: Can the Raspberry Pi B+ run Kodi efficiently or should I get the Raspberry Pi 3?
Comment: If you have to buy one or the other I would suggest the Pi3, for the small difference in price, it is a big jump in performance
Comment: I know i just found my B+. I guess I ll give it a try and if not good enough get a Pi 3
Answer: I have Kodi running (as part of OpenELEC) on a Raspberry Pi model B (not the +) and it does just fine, including playing Blue-Ray videos over the network. So the answer is: yes, it will run fine - however, if you install Kodi on a "normal" raspbian installation there is more overhead than running it as part of the immensely tuned OpenELEC.
Answer: I've had various flavours of pi tucked behind my tv running kodi for years now, upgrading whenever a new model turns up. The biggest differences you're likely to notice moving between the pi A/B -> A+/B+ -> pi 2 -> pi 3 are the performance of the graphics (faster, slicker menus), and the performance of the scraping system. The scraping part is a much bigger deal. When you're dealing with fairly large libraries it can get you down waiting the best part of a day for the first pass at identifying all your files. Adding more library content and waiting for it to be scraped, added to your database, and the changes propagated to clients like yatse, is boring. Later models reduce this significantly.
Streaming performance is fine on lower end models, but I'd strongly recommend at least a pi 2 just for the usability bump.
Answer: I know this post is about a year old now but for anyone else stumbling across: i'm running kodi on xbian on my pi b+ and it runs ok but its nowhere near smooth. Loading and menu building times are an issue and if you've got a boy-/girlfriend sitting next to you who is used to watching online streams on a laptop or pc you will have to deal with some criticism x) better get a newer model as suggested and please double check any devices bought on ebay, as that is how i ended up with a model b+ instead of 2b.


SIP Websocket Client implementation in C++

Question: I need to implement a SIP websocket client using c++. I have npm SIP websocket server. I want to test the connection using c/c++. Is there any easy to use libraries available to implement SIP websocket client in c/c++ ?
Answer: If course there is. Have a look at WebSocket++.
As to exactly how to do it - I wouldn't know since I don't know the SIP protocol. But I'll venture a guess that you need to use binary frames in WebSocket. The server, which you say already exists, obviously has implemented it - and its documentation should contain some information on how to interface with it.


Non-Muslims and the Koran

Question: Does the Koran give permission to kill Non-Muslims? Since I read so many reports of Muslims pressuring Christians to take down Christmas trees, destroying Buddhist monuments, Western cultural artifacts it seems that Islam will not tolerate anything that is not Islam. I read that many Non-Muslims are dying (being killed) because they will not give up faith in God that Muslims perceive as wrong. I wonder how the future of humanity will be if Muslims attack Non-Muslims. Where do aggressive Muslims get the right to attack Non-Muslims? Does this permission really exist within the Koran?
Answer: Islam is a relgion of peace and invites everyone to be peaceful towards others.
There are 2 things we could say about it:

Nowadays the medias and politics of the non-Muslim countries can't tolerate the development of islam, so they persuade people that Islam is the religion of war, horror and fight. That's why first Alqaeda then Taleban and now Daesh is created by them to show a horror face of Islam that it never had. If you go deep into the logics of islam and read the holy Quran, its always mentioned to be peaceful and show kindness towards others and other religions.
If you really wanna know who are behind these things then you will never go to see what Muslims do. Instead you will search for what Islam says.
Check out Islam in Turkey, Indonesia, Malaysia and ... countries if you wanna see what muslims are doing.

And talking about Buddhists just as an example. See what have they have done to Muslims in Myanmar? Why isn't anyone taking any action about that? The same way others.
May god open your mind and show you the truth. And hope my words haven't hurt you.
Comment: You neither answered the question nor added references to your answer!
Comment: That wasnt a question that needs a lot of additional references.

Non-Muslims and the Koran


What workflow should I use for managing model releases?

Question: Managing and collecting model releases might become a tiresome job, specially for hobby photographers like me. Asking a stranger to sign a paper might become trick in most cases, specially in a 3rd world country where most people cannot read written english. So, is there any effecient workflow for collecting and managing model releases? Do I ask for the sign before or after the shooting session? Also, in case of a complete stranger in a street how do I approach? Do I need to collect model releases for every person I shoot even without knowing whether I will use their image in a commercial way or not?
Comment: the whole field of model releases unless it's an actual 'model shoot' seems to be a nightmare. ive seen many shots on getty's site that i am pretty/very sure people have no model releases for. people posing in 3rd world countries, sports players, etc etc. i guess it only becomes a problem if they see themsleves in a magazine or on a billboard :-/
Comment: So you're saying its safe to make fake releases as long as the models wont see themselves?
Comment: Getty requires model releases unless the image is editorial. It is not safe to fake *anything*.
Answer: Images used for news or artistic works do not normally require a model release. In the first case, it would be unrealistic to expect a newspaper, for example, to get model releases before publishing pictures of a large group of people in a protest. For artistic purposes, there are a large number of street photographers taking pictures of people on the streets for artistic purposes, again without release. Now, in that case, if there was a desire for the image to be used for commercial purposes, such as stock for Getty (which is where I think you're going based on your previous question), they'd be out of luck.
So, for candid photography, getting a model release does give you some additional flexibility in the use of the image, but it's not actually required if the image isn't going to be used for commercial purposes. As for approaching them, well, that's tough... I'd have a hard time with it, I think, but not everyone does.
For actual working shoots, and I've only done a couple, the answer is sign everything before shooting. This includes any model releases, and possibly the buyer contracts, that stipulates the usage rights and other details, including payment. Never do the work until you have all those figured out, it protects you and it protects the models. Don't worry, people modeling for commercial purposes generally expect the release and they won't be shocked by the contents of it.
Comment: Be careful. Privacy legislation varies wildly from one country to another. For example, in Spain it is OK to shoot at people at a protest/public event without permission, but it is in general forbidden in any other circumstance. Publishing candid shots is definitely illegal without a model release.
Comment: @pau.estalella - There are exceptions in Spain as well, a lot of which depends on whether or not they're the subject rather than incidental. It is true, however, that one should always seek legal advice before use if you're not sure, but by and large the guidelines I listed above are typical in my experience.
Comment: @drewbenn - Good point. Mind you, it's not just hard, it's impossible, so probably a good thing the law has other expectations. :)


How can I construct D-modules over projective space using explicit differential equations?

Question: Over $\mathbb{A}^n$, it is easy to construct D-modules by writing down an explicit linear system of PDE's and then writing a presentation of the associated D-module
$$
\mathcal{D}^n \xrightarrow{} \mathcal{D}^m \to \mathcal{M} \to 0
$$
Is there an analogous process for constructing D-modules over projective space as an explicit system of differential equations?
Answer: You can construct $\mathcal{D}$ modules on projective space (or actually any space) by precisely the same process: write down a system of PDE's (using differential operators on the whole of $\mathbb{P}^n$) and consider the corresponding quotient.  The key caveat is that on a general space, not every $\mathcal{D}$-module will be of this form: some of them can be defined using systems on different coordinate patches which are consistent, but not globally (I think a degree 0 line bundle on an elliptic curve should give a counterexample). However, $\mathbb{P}^n$ is special, and every $\mathcal{D}$-module can be defined this way (by the Beilinson-Bernstein theorem).
Comment: @user251222 Those expressions don't even make sense as differential operators, since they have poles at $\infty$.  The polynomial differential operators are generated by $x_i\frac{\partial}{\partial x_j}$.
Comment: Also take a look at "D-modules on Smooth Toric Varieties" (https://arxiv.org/abs/math/0007099)
Comment: Look at Section 11.3 of Hotta, Takeuchi and Tanisaki (http://www.math.columbia.edu/~scautis/dmodules/hottaetal.pdf).  The essential point is that these vector fields (thought of as functions on $T^*\mathbb{P}^n$) generate all the polynomial functions on the cotangent bundle, since the induced map from $T^*\mathbb{P}^n$ to $(n+1)\times (n+1)$-matrices is a resolution of singularities of the rank $\leq 1$ matrices.
Comment: Will $\mathcal{D}_{\mathbb{P}^n}(\mathbb{P}^n) = \mathbb{C}\left[\frac{\partial}{\partial x_0}, \ldots, \frac{\partial}{\partial x_n}\right]$?
Comment: Oh, why is that true? Do you have a reference?


Is there any reason behind Enterprise wsdl being recommended for Customers over partner wsdl

Question: Is there any reason behind Enterprise WSDL being recommended for Customers over partner WSDL? Is it that Enterprise WSDL is more secure than Partner WSDL?
Please throw some light on the security perspective of both the WSDL types?
Answer: This Knowledge Article might help you for understanding Why Enterprise WSDl is recommended for customers
Differences Between Enterprise and partner WSDl
Answer: Personally, I've never used the Enterprise WSDL for anything other than quick one off integrations that aren't going to be around for very long.
Why?
While it's handy having the strongly typed Enterprise WSDL to generate all the corresponding types into your language of choice it can be a pain as time ticks on. The Enterprise WSDL:

... is tied (bound) to a specific configuration of Salesforce (ie. a specific organization's Salesforce configuration)
... changes if modifications (e.g custom fields or custom objects) are made to an organization's Salesforce configuration.

Source - Salesforce provides two WSDL files, what are the differences?
I've never worked with an org for any period of time that doesn't have configuration and metadata changes. An integration based on the Enterprise API could readily break as changes are made in Salesforce.
So while the Partner API is more work up front it gives much greater flexibility in being metadata driven. You can code around it to adapt to field changes using describeSObjects.
I.e. I'll typically be told of changes that are going to occur in production ahead of them being deployed. I can have code deployed to my integrations that will check the metadata exposed via the Partner API to activate as soon as those Salesforce changes are present.
Allowing for the same behavior with the Enterprise API would be more difficult.
Answer: The security will be the same.
The general rule of thumb is if you are writing code for a specific org, then the Enterprise WSDL will be easier to use.  This is because code generation tools will be able to generate strongly typed objects for you to work with.
If you are writing code that will be used in multiple orgs, then the Partner WSDL offers greater flexibility.  The downside here is that you will have to work with raw values that are sent in the XML <any> tag.  This will require you to manually serialize/deserialize values in your code.
Answer: Enterprise WSDL contains an org's customizations thus any client application integrating with your org must understand and conform to your org's customizations. For example, you want to build a Java-based application that aggregates sales data from your company's in-house eCommerce platform, and upload  them to a set of custom objects that comprise your heavily customized Sales Cloud.
Partner WSDL is for building client applications that can work for any org so it is more "abstract". It does not immediately understand or know the customizations in the org you connect it to, but it gives you tools to understand them. Example apps: data loader, workbench, etc.


What vectorial file format is usually used for working well with both CorelDraw and Illustrator?

Question: I am creating some templates and upload them to my website for people to used them in whatever software they have. The file needs to be vectorial and open the dimensions correctly in every program (page size, guidelines, shapes, etc)
I know that a PDF created in Illustrator could create problems in Corel Draw and I assume could be vice-versa, as PDF being an Illustrator file.
I am using Corel Draw X6 to create this templates.
Answer: The problem is with some specific effects, normally some kind of gradients and shadows that could be rasterized in the PDF file.
If you use just flat "design" you will have less issues.
But in reality there is no universal file format. If you make a template for Corel it would be nice to have well organized layers. A PDF or EPS file format could loose that information. A PDF also trims blocks of text into single lines.
Probably the best option is to provide a zip file with 2 file formats. A Corel file and an AI file.
Comment: So, an AI file exported from CorelDraw you would say that is safe for using in Illustrator? I am refering to flat design file, no effects, no shadows, no gradients. I am asking because I only have Draw to work with.
Comment: The zip file is what I went for, with CDR and AI. Thanks.
Answer: I wouldn't go down the road of trying to support any one particular vector drawing application, because there are so many different apps today. And even any one app may have multiple versions of its format. You would have to buy CorelDraw and Sketch and Graphic and many others to support all of the users who may want your template.
There are three standardized vector graphics formats for sharing: SVG, PDF, and EPS. Note that the standard PDF is not an Illustrator PDF you Save out of Illustrator, it is a standard PDF that you Export out of Illustrator and choose a standardized version of PDF. All three of these formats can be created with the Illustrator that you already have. It is a manageable, practical project to create and share all three.
However, I wouldn't do that either. I would publish just an SVG, for the following reasons:

you can focus all your effort on making (and revising, and maintaining) the very best SVG for each template with exactly the features that you feel are important to share with the user
SVG imports into almost any vector editor, and can even be edited as text in a text editor where a user could replace the boilerplate text with their own text and that might be all they need to do for some templates
SVG supports layers, real drop shadows (not bitmap renders) and other effects, editable text blocks, and other features you expect to be able to share with your users
you don't have to offer a download at all, you can just place the SVG into a Web page and the user can see the native SVG and then just save it like they would a PNG or JPEG that they like — this skips the zip step that is confusing for some and really hard in some situations like on iPads where the user hasn't installed an app that can download and decode zips
your entire published work, including the Web page where you offer these templates, ends up being Web-native and future-proofed — if you make these templates for a year and then stop, you could leave them up and people will still be using them 10 years from now with no further work from you
SVG is a vendor neutral standard that is made for sharing, so you are doing the right thing by sharing in this format, and rewarding software developers who built good SVG support into their apps, enabling people like you to share templates like this broadly with all interested users
SVG file size is very, very small, so you will be able to serve more users with the same server
SVG is made for modern online publishing, not just for print, so it has animation and interactivity features that you might enjoy exploring and sharing with users
Answer: Many stock illustration websites use *.EPS as a format to distribute vector files, but as Rafael mentioned in the other answer, there is no universal option. Make sure to leave your shapes and objects as simple as possible, without resorting to effects and features that you know are unique to a specific program.
Also, consider those files as production files, and always keep your original resources in a native format (such as *.AI in Illustrator and *.CDR in CorelDRAW) to make sure you won't lose any configuration that may be rasterized or transformed with *.EPS and *.PDF conversions.