Tridion Publishing error Logs

Question: Can we get more information/root cause whenever an item publishing fails apart from error message shown on Tridion UI.
I want to write a custom code to get more information on error rather than checking log files.
Answer: Here are the logs which are helpful during publish and their configuration:
Event Viewer:
Tridion
Tridion Content Manager
Logfiles on CM/Publisher Servers:
%TridionHome%\log\TcmPublisher.log
%TridionHome%\log\cd_transport.log
LogFiles on Deployers:
cd_deployer.log
cd_core.log
Configuring logging level and their locations:
Modify the logback.xml under %TridionHome%\config on CM and Publisher servers to specify logging location and level
Modify the logback.xml under %httpupload%\bin\config on Deployer servers to specify logging location and level
Thus far I haven't felt a specific need to log what Tridion already logs in these logs. The information is sufficient to debug most issues. Also, templating logs are a place where you can hook in logs you want from your TBBs, since you want to log during publish.
Answer: The information about root causes is to be found in various log files. Depending where something goes wrong, you will need to look either in the Windows event logs on the publisher server, the transport log, or in the logs of your upload application, such as the deployer log.
So actually, checking logs is what you'll need to do. The information will most likely be in there, although sometimes it helps to set the logging level to debug if you're troubleshooting something difficult. If you want to check them programmatically, there's nothing to stop you doing that.
Comment: And if you make something funky, take a look at the http://www.alchemywebstore.com/ to write your customization in :)

Tridion Publishing error Logs


Car won't start without a jump

Question: Kia Sedona 2004. Battery was corroded. Car died. Replaced battery. Car started only after jumped, but died very soon. Battery wont keep a charge. When it does start, headlights and gauges won't work. Won't take charge and only starts after jump.
Answer: Give the car a jump start, but let the leads from the donor vehicle stay on the new battery for a period of time. Check the battery to ensure there is sufficient charge in it (at least 12vdc) to keep the vehicle running. Get the Sedona started and then pull the leads from the donor vehicle. Check the voltage at the battery. If the voltage continues to drop at a slow pace while it's running, the alternator is most likely bad. Pull it from the vehicle, take it down to the parts store and get it checked.
Also, ensure the battery posts and leads are completely free of corrosion. If it isn't, the battery won't charge. Your issue lies in the fact the battery, whether completely new or the old one, is not getting charged. It is either the alternator not charging it, or there's no way for the charge to get to the battery.
Comment: If the headlights etc don't work *even when the engine is running after a jump start*, that is a very clear indication the alternator isn't working. Most of the time tThe alternator
Answer: i just replaced my alternator as i had a similiar problem, would firstly recommend checking all leads to and from the battery for any connection issues, as the previous corrosion from the battery may have damaged leads too, then get a mechanic to check your battery voltage, this will tell you if your alternator is in fact charging your battery, it really is as simple as that.
good luck
Answer:
Battery was corroded...replaced battery

Did you clean the wires' connectors to the battery? Replacement battery is new, or used and serviced and charged? Connections needs to be pristine! Battery should be >12VDC

Car started only after jumped, but died very soon

This is common when the engine is running with battery current, instead of battery/alternator pair supplying the current. Could mean a faulting current regulator in the alternator, or the alternator itself.

Battery wont keep a charge.

Can you try charging the battery with an external charger, and measure it gets 13 ~ 13.5VDC? This may not be a good test to decide if the battery is good (current may drop a lot if the battery is bad), but at least will tell you the battery has some juice.
On the other hand: if the current regulator or alternator is in fault, the battery won't get properly charged. Besides, if the battery is low in charge, it needs some time to get charged. Cranking and testing the engine won't supply enough time to charge it to normal operational level.

When it does start, headlights and gauges won't work. Won't take
  charge and only starts after jump.

IMHO, the alternator is faulting or at least the current regulator is not working: your engine is running on battery, the jumping would be adding some little power to it, enough to crank once, but after the engine is running, no power is being supplied to it by the alternator, and in the contrary, the engine is sucking the little power it got by using it for sparks.
My suggestion: charge battery externally and give it a try. If it stills does the joke: check alternator output, check alternator belt is not slipping.
One way to test if alternator is charging: once running the engine: turn on all lights and high beam...if the alternator is good, the engine will still running, if alternator is bad, the load will deplete the battery stalling the engine :) Source? A lot of headache last year with an alternator having intermittent faults!

Car won't start without a jump


How to install Apps through AppCenter on Loki?

Question: I can't find lots of Apps in AppCenter, such as Firefox, How to install them through the AppCenter?
Comment: I have downloaded a `.deb` file of Skype and try to open it in AppCenter, but nothing happened. AppCenter does not list Skype itself.
Answer: You can install .deb files with apt in terminal with...
sudo apt install ./filename.deb
So in the folder of your .deb file open a terminal with mouse right click.
Open in > Terminal and use this command above.
Answer: The app center does not handle deb packages. This is what I did and it works for me.  I installed GDebi Package Installer(Cardboard box one) from the App Center. Which allowed me to install deb packages, but it removed my files manager so I went and installed another files manager called "Files" but in the description it will say its "Nautilus, also known as Files, is the default file manager of the GNOME desktop."
I got Chrome(for netflix), slack, discord, obs, Atom editor, Adobe Brackets, playsonlinux, Steam, and few more key apps installed that are not available thru the App Center.  There are apps on available thru the App Center that do not mesh well with the Loki.  Dolphin Files Manager, Ubuntu's Software Center, and etc.  Confuses me.
Update: Found and Install Firefox thru the App Center no problem and ran it no problem too.
Comment: I can't find any non-elementary app in the AppCenter on Loki Beta2.
Answer: Well ... assuming you know how to find the download (the deb package) for what you want to install ... you download it and them open it with AppCenter ... this will either install the application or add a PPA that them let's you install the application.
BTW PPA is Personal Package Archive ... basically it adds a link to where the package can be downloaded from.
Comment: I don't need to add ppa or download deb package, I want to install the packages like how apt does, but I can't find the packages in the AppCenter.


Why is Java considered more portable than other languages like C++?

Question: What differs between "writing a specific JRE for each platform" for Java developers and "writing a C++ compiler for each platform" for C++ ones?
Answer: Java is compile once run anywhere.
C++ is write once compile anywhere.
Comment: Anyone who claims that C++ is "write once compile anywhere" has never had to port a C++ program...
Comment: @Pubby8 no, portability issues also come from pretty standard code that *makes nonportable assumptions*, like assumptions about endianness (which mind you, you can also suffer from in Java), alignment, and sizeof fundamental types.
Comment: I agree with BlueRaja. Porting a C++ program means so much more than porting the compiler. C++ is most widely present in critical environments where things like the size of an int or the implementation of a file system can make such a big difference. Porting does NOT simply mean recompiling.
Comment: Write once, debug everywhere.
Comment: Well you've obviously not had much experience with GUI development. (Waiting for Qt...)
Comment: @BlueRaja-DannyPflughoeft: truth be told: "Porting" a Java program may not involve recompilation in the good case, but a *badly* written Java program may still encode plenty of assumptions about the platform that may not hold on other platforms.
Comment: This totally doesn't answer the question. Why does it have so many upvotes? Just because it's pithy?
Comment: Portability issues come from nonstandard code and non-free licenses. It's not C++ fault - it's microsoft's & friends.
Comment: @GlennNelson Java has a much more restricted scope when it comes to portability, therefore it is able to provide standardized GUI. C++ has to rely on external libraries, but when you look at the most supported ones, they cover pretty much the same platforms as Java does.
Comment: This answer is true; the important thing to remember is **context**.  It doesn't mean that the program will do what you expect it to each time, just that it'll do what the language has defined each time.  But for it to even do what the language has defined, you do have to recompile the program for different platforms, which is generally a non-issue for Java.
Answer: "writing a specific JRE for each platform" is not something you do everytime. Porting the JRE to a new platform is something you need doing only once. This task is generally done by the core maintainer/developers of the program and/or the platform. A lot of factors may come into play when deciding who and how the JRE would be ported. Among other things, it depends on the licensed it's published under (I hear Java is Open Source, so I guess anyone could do it). Funny anecdote, Steve Jobs made a big deal about not wanting to take care of the porting of Java on Mac, around a year ago.
The point is not how or who ports the JRE, but the fact that once it is ported, every Java application should now theoretically run easily on the new machine. In that sense, the JRE forms an abstraction layer, completely hiding the machine, allowing easy porting.
However, reality is not always pretty like this. I won't go as far as calling portability a "myth", but it's true that it's not so perfect. For instance, Java has a package called JNI that allows sending native calls, bypassing the JRE, thus preventing the perfect seamless portability, what Java fans like to call "Write once run everywhere".
As mentioned in the comments, C++'s approach to portability is different. On the one hand, it's a compiled language, and those binaries are almost always platform specific. So c++ executables will never be portable (unlike Java). On the other hand, porting the compiler can sometimes be enough. The community has found that by porting the compiler as well as some core libraries of the language, source codes (and not binaries) could be portable.
However, C++ is widely used in critical systems like compilers, kernels, real-time systems,embedded systems, ... There's a "low level" aspect of C++ that cannot be overlooked, when talking about portability.
Comment: Portability is not a myth. Perfect portability is.
Comment: "his is where Java is very different from C++, where each application is "machine-specific", and cannot be ported without modifying the code." That's not true, it depends on the dependencies. If you only use the standard library and libraries with sources portable to your targets, you code once and compile on each target. If you code something that can be ported without modifying the code in C++ then the only thing you might need to modify are the build scripts. That's not even true in all cases.
Comment: Let's not forget that C++ can be used as both a high-level and a low level language. A lot of C++ code is used in programs where a 32bit int is very different from a 64-bit int. High-level will always be portable, of course. But it's far from a C++ generalization
Comment: I think you might have misunderstood what I'm saying : you can write correct C++ with int or any standard type without bothering with low-level stuff. Just take a look at boost libraries, most are only high level code, and that's true for a lot of C++ open source project. You "can" go low level, and if you do you can also avoid any specific code until you need to use platform specific API. But if you don't need to, then you can write C++ that works everywhere. Dependency to platform can be avoided and often is in library code.
Comment: Just to be sure I'm clear : I don't say that all C++ code is portable, I'm saying that as is, your statement is wrong. You might want to fix it with something like : "This is where Java is very different from C++, where each application is "machine-specific", and cannot be ported without modifying the code or, if the code really is portable and the build scripts manage the new target, without at least one compilation."
Comment: You are right, I had misunderstood. I corrected the sentence, thanks for the remark.
Comment: I understand that calling portability  a java caracteristic is quite far-fetched
Answer: It's not just the language -- it's the libraries.
Both Java and C++ provide cross-platform libraries. Java provides a richer set.
Comment: Definitely disagree with that. Anything in the Java library is available is already available for use by C++ in some library. I like the fact that Java has it all in one place but to say it is richer is just not true. Maybe the adjective you are looking for is `more integrated'
Comment: Java provides a richer set by default. The same libraries can be found for C++ they are just not part of the standard libraries and you just have to decide which ones to use (which is not trivial especially if they are not installed).
Comment: +1 would upvote again. I think the libraries are the biggest factor in portability. If you're working in C/C++ and doing anything other than pure computation, there will be libraries (in particular, parts of the system library) that are radically different between Windows and Unix, and subtly different between different flavours of Unix. That makes porting hard. Java basically doesn't have that problem.
Comment: @Andy Thomas-Cramer: I am not comparing anything (you seem to be). I am saying your statement is inaccurate. One of the advantages Java has (and we all love it for that) is all the standard libraries in one place. Saying they are richer is just not accurate.
Comment: Comparing the standard libraries of Java to the universe of libraries for C++ is not really a valid comparison. Java provides a richer set, whether you're comparing the standard libraries of each, or you're comparing the universe of libraries of each.
Comment: @Tux-D, you're comparing apples and tractors.
Answer: The difference is that Java will run on any platform without recompiling.  Having a C++ compiler for each platform isn't the same at all.
Answer: All the answers starting with "The difference is...", or anything very similar, are basically wrong (sorry, but such is life). There are really two separate differences between the two.
One (that's been mentioned a lot) is that a compiled Java program can (or least should) run on any conforming implementation of Java, so even after being compiled, you can still move a Java program from one platform to another without re-compiling. C++ (at least normally) requires re-compilation for each target platform.
The other is that Java (at least attempts to) assure that all correctly written Java will be portable. At least in theory, you shouldn't be able to write any code that isn't portable.
C++ allows you to do quite a few things that aren't portable. The C++ standard contains "warnings" about a lot of things that aren't portable (e.g., telling you that you'll get implementation defined behavior or undefined behavior), but it doesn't necessarily try to stop you from doing them at all. Just for example, if you want to write an operating system for hardware that uses a PCI bus, you're probably going to need to read/write the PCI configuration memory. This obviously won't be portable to systems without a PCI bus, but if you're writing an operating system for hardware with a PCI bus, it's pretty much necessary.  C++ allows it even though it obviously won't be portable.
Comment: @Nikko: It knows nothing anything about it, but it allows you to use what *you* know about it.
Comment: C++ doesn't know anything about PCI bus nor hardware though.
Comment: of course it doesn't, those are platform specific things that will have to be included in platform specific libraries. Just as Java can have platform specific libraries if needed.
Comment: @jwenting: The difference being that you can write the platform-specific libraries in C++, but you generally *can't* write them in Java.
Answer: You have misunderstood the premises.  Java programs are very portable, because the JVM provides a standard behaviour guaranteed to be the same.  C++ programs have a less standardized environment closer to the actual hardware, so the program needs to be able to handle the various platform specific details - like size of an int, word alignment etc etc etc.
The JVM itself is not very portable.  It is a herculean task to port a high-performant JVM to another platform or CPU architecture.
Comment: +1 for that last sentence!
Answer: The difference is that Java (it's not an acronym) programs can be distributed in a form that can be run on any computer with a JVM installed, but C++ is normally distributed as either source code, which is very user unfriendly, or as a bunch of different binaries for different platforms.
Comment: Huh? There are C++ compilers which target the JVM and there are Java compilers which target native code. Can you cite the specific section of the C++ language specification which says that C++ programs *must* be distributed as either source code or platform-specific binaries?
Comment: There, I edited my answer to use less definitive language
Answer: One of the reasons Java is considered portable is that it has specific rules for how arithmetic expressions must be valuated and forbids implementations from evaluating them any other way, even when evaluating them in the mandated fashion would require slower code than evaluating them in a more accurate fashion.
For example, given
long thing1(int x) {
  return (x+1)-1L;
}
double thing2(int x, float y) {
  return x/y;
}

The values of thing1(2147483647) and thing2(1123456700,11234567.0f) are required to be -2147483649L and 99.9999923706054688, respectively, even though the arithmetically correct values would be 2147483647L and 100.0, and even though on some platforms code to generate the numerically-incorrect results would be slower than code to generate the correct results (on some 64-bit platforms, forcing the wrapping behavior after (x+1) would require an extra instruction, and on the 8x87 platform, forcing the value of 1123456700 to be rounded to a float would require an extra instruction compared with simply loading it directly to an extended-precision register).
Comment: For once a new answer on an old question that actually adds something of value: Java has very precise arithmetic requirements, and of course the primitive data types have specific sizes and semantics compared to C++. No other answer as of this date mentions this.
Comment: @Snowman: How do you like the particular examples chosen?  Personally if I were designing a language I would not have made the either example return Java's value without the use of narrowing casts to `(int)` for the first example's `(x+1)` subexpression in the first example, to `float` the second example's `x` parameter, but obviously I didn't design the language.
Comment: I think they make sense. The important thing for any language is to have well-defined semantics. Regardless of whether one agrees with a given language design decision, the important thing is being able to look at the code and _know_ how it works. Java generally does that, with few cases of undefined behavior.
Answer: The amount of work for the supporting tools is indeed similar, the difference lies elsewhere. Once a C++ program has been compiled for a platform, you have to compile it again if you want to use it on a different platform. However, when a java program has been compiled, you can move it to any other platform with a runtime environment without having to recompile it.
Answer: Answering the title "Is portability a myth ?", instead of "Which is better at portability, Java or C++", I'll say that partial portability is possible, but full portability it's does a myth.
Something that I insist to write, and it applies to this question, is that developers are not longer working with just programming languages, but, with full programming frameworks.
And those frameworks, include libraries, databases, graphical interfaces.
Which programming language, or which programming framework is more portable ?
Well, it depends, on what your app. is trying to achieve.
Answer: The thing is "you" don't write the JRE you write the Java code which runs on any JRE. "You" do write the C++ code which can require changes by you before it will compile on another platform.
Answer: Many people forget or do not take into account the reality of Java when they say that "it's 100% portable" or phrases like that .
Pretty much all the major Corporations / Software house had at least 1 home-made implementation of Java with an associated JRE in the recent past and some still do maintain it, Microsoft, IBM and Apple for example all had their own version of Java reflecting their own ideas and thoughts on where the industry and such language should go .
How is that for "portable" ? A JRE anywhere you turn .
And this is without considering what Sun/Oracle was doing.
An example on why Java code is not really far from C and C++ in terms of portability are the GUIs and the graphical servers, Apple had a non-standard implementation of the GUI framework for its own JRE, as a consequence there were a lot of headaches and double work for anyone who wanted to create/port a GUI using Java for Apple machines and they were basically forced to deal with Quartz ( how is that in terms of "leverage" and high level languages ?).
Sometimes even the most common used words don't really reflect the meaning that people usually give them, to me the term "portability" in the Java world is more like "outlook" in the common sense; in commercial and financial terms there is a better outlook for you if you adopt Java rather than other languages ( at least at the time when Java was born ) because you have a lot of work already done on one side ( you get a JRE on anything that can be considered a "computer" ) and your codebase is likely to be portable as it is, you need less resources to port your program, that's it, whether said resource is money, time or manpower doesn't matter, it's a lower threshold compared to other technologies and that's what Java is for, it is lowering that threshold .
Of course this is true if you accept the premises of Java, which means a virtual machine with garbage collection, which means it consumes more resources if compared to native languages, if you really want to squeeze the maximum out of your CPU or server farm I don't think that you can adopt Java unless you are really low on resources or your company is really small .
I still have to find a single non-trivial Java application that contains only 1 version for each line of code or functionality ( aka without any platform specific stuff ) and it's 100% portable among all the major JREs.


Is there an equivalent to derandomization for quantum algorithms?

Question: With some randomized algorithms you can derandomize the algorithm, removing (at a possible cost in run time) the use of random bits and maximizing some lower bound on the objective (usually computed using the fact that the theorems are about the expected performance of the random algorithm). Is there an equivalent for quantum algorithms? Are there any well-known results of "dequantization"? Or is the underlying state space too big for this sort of technique?
Comment: Should I make this community wiki? There are so many interesting answers touching on different aspects of the problem that this question doesn't feel like it has to have a single correct answer anymore.
Answer: There are certain classes of quantum gates which can be simulated efficiently with a classical computer. If no entanglement is present, a computation with pure states (i.e. not random states) can be simulated efficiently. Classical gates reversible gates are a subset of quantum gates, and so can obviously be simulated efficiently. These two examples are pretty trivial, however there are a number of non-trivial gate sets known.

Valiant gates as mentioned in Joshua's answer
Clifford group gates (see arXiv:quant-ph/0406196)
Match gates (see arXiv:0804.4050)
Commuting gates, etc.

Basically, most sets of operators which generate only some small subspace of $SU(2^N)$ tend to be simulable, while any that generate $SU(2^N)$ are as hard as general quantum simulation of N qubits.
It seems very unlikely that quantum mechanics is efficiently simulable, and so such a dequantization program will likely be impossible in general. There is however a regime where this has worked, which is with interactive proofs. Several different kinds of interactive proof systems with quantum verifiers have been shown to have the same power if the quantum verifier is replaced with a purely classical verifier. For an example of this, see Jain, Ji, Upadhyay and Watrous's proof that QIP=PSPACE (arXiv:0907.4737).
Answer: There was a blog post by Fortnow on this topic.  It's believed that there's no hope of a "dequantization" program, similar to the derandomization one.
On the other hand, for some specific non-quantum results that were obtained using quantum methods, it has been possible to remove the quantumness in the proof.  For example, Kerenidis and de Wolf (2002) proved the first exponential lower bound for the length of possibly non-linear 2-query locally decodable codes using quantum arguments.  Later, Ben-Aroya, Regev and de Wolf (2007) could remove the quantumness of the proof (although the line of argument still modeled the quantum one).  Similar situations also arose in proving lower bounds for rigidity of Hadamard matrices, and in showing that PP is closed under intersection (though in reverse chronological order :)).  See this survey by Drucker and de Wolf for references and discussion.
Comment: I asked that question at the conference so that Fortnow made that blog post.
Answer: One interesting setting in which to study "dequantization" is communication complexity. Here, an interesting question is whether an upper bound can be put on the amount of entanglement that Alice and Bob need to share in order to achieve an efficient quantum protocol for solving some problem. This would be a quantum analogue of Newman's Theorem from classical communication complexity. Gavinsky has given a relational problem for which this cannot be done, but as far as I am aware this is still open for (total) functional problems.
Also, an addendum to Joe's comment about commuting gates: Bremner, Jozsa and Shepherd have recently shown (arXiv:1005.1407) that a particular notion of commuting circuits is unlikely to be simulable, as this would collapse the polynomial hierarchy to the third level.
Answer: Although in general "dequantization" is unlikely, I believe that this sort of idea helped inspire Valiant's holographic algorithms.  Or, at the very least, you can view his work as some partial dequantization results on restricted classes of quantum circuits.  See, for example: L. Valiant. Quantum Circuits That Can Be Simulated Classically in Polynomial Time. SIAM J. Comput. 31 (4) 1229-1254 (2002).


Hausdorff ultrafilters

Question: I know that Ramsey ultrafilters are Hausdorff ($\mathcal{U}$ is Hausdorff iff for every $f,g:\mathbb{N}\rightarrow\mathbb{N}$ $f(\mathcal{U})=g(\mathcal{U})$ then $f\cong_\mathcal{U} g$ $\;$). So if we assume the continuum hypothesis then there exist Hausdorff ultrafilters. I'm wondering this: if we assume continuum hypothesis then there exists a Hausdorff ultrafilter not Ramsey?
Comment: So an ultrafilter is Hausdorff is whenever two functions, when extended to $P(\mathbb N)$ act the same on $\mathcal U$ it implies they only differ by a null set?
Comment: $f(\mathcal{U}):=\{X\subset\mathbb{N}:f^{-1}(X)\in\mathcal{U}\}\;\;\;\;$ and $f\cong_\mathcal{U} g\;\;$ means that the differ by a null set.
Answer: Under the continuum hypothesis, or even Martin's Axiom, there are Hausdorff ultrafilters that are not selective.  The following is a good survey by Fremlin of many related matters:
http://www.essex.ac.uk/maths/people/fremlin/n09102.pdf
The construction, under CH, of such ultrafilters goes back to Andreas Blass, in the 1970s.
The harder question of whether the existence of Hausdorff ulrafilters can be proved in ZFC was settled not many years ago.  The answer is no.  Shelah is one of the authors.
Comment: Is there an easier article than http://www.essex.ac.uk/maths/people/fremlin/n09102.pdf maybe the Blass one?
The preprint in which Shelah proved the existence of a model withouth Hausdorff ultrafilters contained an error and it has been retired, so it is still an open problem.
Comment: @Jacob Fox: Will try to think of one.  The Shelah paper retraction is new to me!  Am a lot out of touch, my last paper on the subject was about $30$ years ago.
Answer: The paper"On the Existence of Nonprincipal Arithmetical Ultrafilters on ω" was appeared in ACTA MATHEMATICA SINICA CHINESE SERIES Mar.2006,49(2): 283-288.
In this paper it is proved that the statement (Q) implies the existence of nonprincipal arithmetical (i.e. Hausdorff ) ultrafilters on ω.
Statement (Q): If B ⊂ P(ω) has the sfip (strong finite intersection property) and |B| < 2^ω, then there is a Q-point q ⊃ B.
Statement (Q) is strongly weaker than Statement (R).
Statement (R): If B ⊂ P(ω) has the sfip (strong finite intersection property) and |B| < 2^ω, then there is a  Ramsey ultrafilter r ⊃ B.
  Fangting Wang
Comment: I see you have decided not to edit your above answer, even though this appears to be a (somewhat) cleaned up form of it.  I also note that you do not provide a link of any sort to this paper, but only mention a couple of results.  As far as I can tell [this](http://www.ams.org/mathscinet-getitem?mr=2252007) is the MathSciNet review for this paper, and [this](http://www.zentralblatt-math.org/zbmath/search/?q=an%3A1121.03069) is the Zentralblatt review.  I note that this paper appears to be only available in Chinese, which may be less than helpful to most math.SE users.
Answer: On the Existence of Nonprincipal Arithmetical
Ultrafilters on ω
Fangting Wang
Department of Mathematics
University of Science and Technology of China
Hefei, Anhui, 230026 P.R.China
Email: firstname.lastname@example.com
January 8, 2013
Abstract
Each nonprincipal arithmetical ultrafilter p ∈ βω−ω is associated with
a simple arithmetical model Np= {f(p) : f ∈ωω} ⊃ N, and a positive real
number is just an equivalence class of finite fractions made by arithmetical
ultrafilters (instead of natural numbers), just like the ancient Greek's idea.
It is well known that MAcountableimplies the statement (Q):
1
(Q)
If B ⊂ P(ω) has the sfip (strong finite intersection property) and
|B| < 2ω, then there is a Q-point q ⊃ B.
In this paper we will prove that the statement (Q) implies our Hypoth-
esis:
There exist nonprincipal arithmetical ultrafilters on ω.
Key words:
the Stone-ˇCech compactification on ω, Q-point,
arithmetical
ultrafilter, arithmetical model
MR(2000): 03E35, 03E65, 54D80, 54D35, 03C62
1
Introduction
βω, the Stone-ˇCech compactification of the discrete space ω, consists of all
ultrafilters on ω. For p ∈ βω and f ∈
ωω, the image of p in βω under the Stone
extention f : βω → βω is given by
f(p) = {a ⊂ ω : f−1[a] ∈ p}.
For f,g ∈
ωω and p ∈ βω, f =pg means that
{n ∈ ω : f(n) = g(n)} ∈ p.
An ultrafilter p ∈ βω is called arithmetical [1], if for all f,g ∈
ωω,
(1)
f(p) = g(p) ↔ f =pg.
2
(The nonprincipal arithmetical ultrafilter was called ∗-point in [2].)
For all f,g ∈
ωω and all ultrafilters p ∈ βω we always have
(2)
f =pg → f(p) = g(p),
but the converse of (2) may not be true [2]. Because of (2), an ultrafilter p is
arithmetical iff for all f,g ∈
ωω,
(3)
f(p) = g(p) → f =pg.
We are interested in this class of ultrafilters since each arithmetical ulrtrafilter
p is associated with a simple arithmetical model Np:
Np= {f(p) : f ∈
ωω}.
In Npthe operations +,· and h(∈
ωω) are defined naturally:
f(p) + g(p) = (f + g)(p),
f(p) · g(p) = (f · g)(p),
h(f(p)) = (h ◦ f)(p).
Npis a structure of the language L = {0,+,·} ∪ {f : f ∈
ωω}. We have the
Transfer between Npand N (the standard arithmetical model):
Transfer For any L∪ {p} -sentence ϕ(p),
Np|= ϕ(p) ↔ {n ∈ ω : N |= ϕ(n)} ∈ p.
3
Specially, for any L-sentence ϕ,
Np|= ϕ ↔ N |= ϕ.
The proof of the Transfer is completed by a simple induction on the length of
ϕ(p). The first step is the property (1) which the arithmetical ultrafilter p has.
Is there a point in βω − ω which is arithmetical? Our Hypothesis (AR) is:
(AR)
There exist nonprincipal arithmetical ultrafilters on ω.
A point q ∈ βω − ω is called a Q-point, if for every partition (ai)i∈ωof ω into
pairwise disjoint finite subsets there exists b ∈ q with |b ∩ ai| ≤ 1 for all i ∈ ω.
We write sfip for "strong finite intersection property", and let (Q) be the
statement:
(Q)
If B ⊂ P(ω) has the sfip and |B| < 2ω, then there is a Q-point q ⊃ B.
Then we have:
Main Theorem The statement (Q) implies the Hypothesis (AR).
Before we prove the main theorem, we list some well-known results about the
existence of Q-points:
1◦MAcountableimplies the statement (Q), and the word "Q-points" in the
statement (Q) can be replaced by "selective (minimal, or Ramsay) ultrafilters"
4
(cf.[3], Th.2).
2◦If there exists a dominant family (inωω) of cardinality ω1, then there exists
a Q-point [4].
3◦the assumption of the existence of Q-point is weaker than MAcountable, since
MAcountableimplies that the cardinality of each dominant family (inωω) must
be 2ω[5].
2
Lemmas
The following lemma 1 improves the proposition 2 in [2].
Lemma 1
For any f,g ∈
ωω and p ∈ βω , if f(p) = g(p) and (f → g)p,
then f =pg, where (f → g)pmeans that
∃a ∈ p ∀x,y ∈ a (f(x) = f(y) → g(x) = g(y)).
Proof Assume f(p) = g(p) and (f → g)p. It suffices to show that both f  h(ni). Hence
∀ni∈ f[ω]∃k ∈ ω(hk(ni) / ∈ f[ω]).
Now let
A = {ni∈ f[ω] : h(ni) ∈ g[ω] − f[ω]},
B = {ni∈ f[ω] − A : the least k such that hk(ni) / ∈ f[ω] is even},
C
= f[ω] − A − B.
The remaining part is the same as in the case f
Comment: This appears to be a poorly executed copy-and-paste job from an article (of yours, if I am not mistaken).  Please consider editing this to make its connection to the question posed clear (and also to make it readable).

Hausdorff ultrafilters


The data in our relational DBMS is getting big, is it the time to move to NoSQL?

Question: We created a social network application for eLearning purposes. It's an experimental project that we are researching on in our lab. It has been used in some case studies for a while and the data in our relational DBMS (SQL Server 2008) is getting big. It's a few gigabytes now and the tables are highly connected to each other. The performance is still fine, but when should we consider other options? Is it the matter of performance?
Comment: For anything social networking, I would **highly** recommend a graph database like [Neo4j](http://neo4j.org) or [OrientDB](http://orientechnologies.com)
Answer: A few gigabytes is not very "big". It's more like the normal size of an enterprise DB. As long as you go over PK when joining tables it should work out really well, even in the future (as long as you don't get TB's of data a day).
Most professionals working in a big data environment consider > ~5TB as the beginning of the term big data. But even then it's not always the best way to just install the next best nosql database. You should always think about the task that you want to archive with the data (aggregate,read,search,mine,..) to find the best tools for you problem.
i.e. if you do alot of searches in you database it would probably be better to run a solr instance/cluster and denormalize your data from a DBMS like Postgres or your SQL Server from time to time and put it into solr instead of just moving the data from sql to nosql in term of persistence and performance.
Answer: To answer this question you have to answer which kind of compromise you can afford. RDBMs implements ACID. This is expensive in terms of resources. There are no NoSQL solutions which are ACID. See CAP theorem to dive deep into these ideas.
So you have to understand each compromise given by each solution and choose the one which is the most appropriate for your problem.
Answer: Big Data is actually not so about the "how big it is".
First, few gigabytes is not big at all, it's almost nothing. So don't bother yourself, your system will continu to work efficiently for some time I think.
Then you have to think of how do you use your data.

SQL approach: Every data is precious, well collected and selected, and the focus is put on storing high valuable and well structured data. This can be costly, everything is interlink, and it's good for well stuctured system and functionnal data.
Big Data approach: In big data you basically store almost everything, regardless of the value it has, and then do a active analytics process. Things are not linked, they are copied. For example let's say I have a blog entry. In Big Data there will not be a link to its author, but the author will be embedded inside the blog entry. Way more scalable, but require a different and more complex approach.

If your storing "functionnal" data use by your application, I will suggest you to remain on SQL. If your storing data in order to search on them later or to do reporting, and if this amount of data may increase quickly, I will suggest big data.
In my opinion, big data is useful when you are dealing with real data that have to be collect and analyzed continuously.
Answer: I posted a pretty detailed answer on stackoverflow about when it is appropriate to use relational vs document (or NoSQL) database, here:
Motivations for using relational database / ORM or document database / ODM
Summary:

for small stuff, go with whatever tools you are familiar with
a few gigabytes is definitely small stuff: it doesn't get big until it is too big to fit in a single MySQL Cluster with a reasonable number of nodes (16-32), which means maybe 8-16TB data and a few million transactions per second (or a more conventional hard-drive-based database with up to 100's of TB data and a few thousand transactions per second).
if you're stuck with another database (not MySQL Cluster), get more mileage out of it by throwing in FusionIO hardware.
once you have data larger than a few TB and faster than thousands of transactions per second, it is a good time to look at moving to logical sharding in the application code first and then to NoSQL.
Cassandra :)
Answer: Is it the time to move to NoSQL will depends on 2 things:

The nature/structure of your data
Your current performance

SQL databases excel when the data is well structured (e.g. when it can be modeled as a table, an Excel spreadsheet, or a set of rows with a fixed number of columns). Also good when you need to do a lot of table joins (which it sounds like you do).
NoSQL databases excel when the data is un-structured beyond key-value pairs.
Performance wise, you gotta ask yourself one question: is your current SQL solution slow?
If not, go with the "IIABDFI" principle.
Answer: There are different ways for you to proceed.
1): Stay with SQL: If the performance stays ok and your data is structured, there is no need to change. Also, remember that if you change to NoSQL, you are losing the ACID properties meaning that your data is not consistent anymore.

Change to NoSQL: If your performance is getting worse, you should try to scale your database horizontally. That is not possible with SQL databases but with NoSQL or NewSQL databases it is. If your data is not structured then NoSQL is your solution.

Change to NewSQL: If performance is an issue, but you cannot compromise on ACID and have structured, relational data, then NewSQL is the perfect fit. It offers horizontal scalability combined with ACID and a relational schema.


Can I go out of the airport while a layover at Singapore?

Question: I am an Indian citizen and I have a flight to Japan with a 7 hour layover at Singapore. I only have a temporary visitor visa for Japan. I was wondering if I could go out of the airport and visit Singapore, and what additional procedures(if any) I might require for that?
Answer: As stated by Timatic, the database used by airlines:

Visa required, except for Nationals of India who can also
  transit, for up to 96 hours without a visa under the Visa Free
  Transit Facility (VFTF) on either the outbound or return leg
  of the same journey (but not on both). Leaving the transit
  area is allowed.
Warning: Holders of a valid single entry visa (or
     multiple entry visa valid for at least one month) issued by
     Australia, Canada, Germany, Japan, New Zealand,
     Switzerland, USA or United Kingdom to nationals of India
     may use the VFTF mentioned above. After using a single
     entry visa and the VFTF was not used on the outbound leg of
     the journey, the VFTF can only be used on the return leg
     with a direct transit through Singapore from the country
     that issued the visa to the country of residence (e.g.,
     SYD-SIN-PEK).

So yes, you can visit Singapore. Present your passport open at the page with the Japanese visa, and your connecting ticket.
Comment: 7 hours is actually plenty for Singapore, the airport even has free transit tours.
Answer: https://www.mfa.gov.sg/content/mfa/overseasmission/new_delhi/visa_information/overview.html
<code>Indian nationals who are in transit to or from any third country by air, may be eligible for the 96-hour VFTF for one transit in the itinerary (either forward or return leg, but not both) if they:

   i. have a valid onward air ticket departing within the next 96-hours; and

  ii. possess a valid visa/long-term pass (with a validity of at least 1 month from the date of entry into Singapore under the VFTF) issued by any of the following countries**:

          a. Australia
          b. Canada
          c. Japan
          d. New Zealand
          e. United Kingdom
          f. United States of America
          g. Germany
          h. Switzerland

** A visa is considered valid if it is not expired and is good for entry into the third country.
** The VFTF for Indian nationals is for air to air travel only, and is only valid for one transit in the itinerary (either forward or return leg, but not both).
</code>


Are Catholic bishops infallible?

Question: I hear that Catholic bishops being considered 'infallible' is untrue and their words can be contested if they are not speaking truths directly from the Bible/other relevent documents. However, even if that myth is not entirely so, to what degree are Catholic Bishops opinion's viewed as infallible (if at all)? Is an ordinary Catholic able to gain 'official' undebatable answers even if that answer isn't in the relevent Catholic readings?
Comment: I think this would be a lot clearer if you explained how it works in the Anglican Church, or edit the title to take that out since you've got nothing in the question about Anglicans.
Comment: Bishops in the Anglican church are not considered infallible, but then for most Anglicans the church is not considered infallible either.
Comment: What do you mean by 'power'? Whatever theological authority is given to bishops, it may or may not translate into any form of power.
Answer: Bishops in themselves are not infallible.  However, they do participate in some way in the infallibility of the Catholic Church.
Catholic Bishops participate in the ordinary and universal episcopal magisterium of the Catholic Church.  This is a fuzzy set of teachings that are infallible, and come from the authority of the Church to teach The Faith.  What exactly are these teachings?  They are the teachings on faith and morals that all the Bishops of the world, including the Pope, universally hold as definitive and true.  Essentially these are all the true doctrines that all Bishops believe and know to be true, but which haven't been declared to be infallible by a Church Council or the Pope because no one has challenged them in any serious way.
To answer your question somewhat: any Catholic lay person can challenge any Bishop in matters of theology and morals.  But most Catholic people will not pay much attention to the challenger because, for the most part, Catholic Bishops are faithful to their calling of teaching the Faith.  Thus, there is a presumption that the Bishop as opposed to the challenger is correct, and the challenger would be mostly ignored.  In principle, if the challenger happens to be right (and the Bishop wrong), and if the dispute/debate were to gain the attention of the faithful in general and of the majority of Bishops (as well as the Pope), and if the Bishops were to start debating the issue in earnest, some agreeing with the challenger, some with the original Bishop, and if the issue raised and/or the debate surrounding it were causing serious disruptions to the life of Faith, then the Pope (or a Church Council) might be needed to clarify the question.  In principle, then, the challenger might actually succeed against the Bishop: not because he is a better debater, but because he was right --- and the fact that his position attracted successful support among the Bishops is the proof of this.
However, for the most part Bishops know the Faith they are teaching.  And for the most part Catholic theologians who disagree with a particular Bishop are actually disagreeing with the majority (if not the unanimity) of Catholic Bishops.  Therefore their dissent goes nowhere.
Comment: Good answer, could benefit from sources and formatting though! Maybe a few [mitre pictures](https://en.wikipedia.org/wiki/Mitre)
Comment: Of course, [sometimes](https://www.google.com/search?q=martin+luther) it doesn't work out so cleanly :)
Comment: @Benjol: You have that right!  Instances of Reformations and/or Schisms are relatively rare though.  They seem to require a relatively large following of people with at least a few Church leaders and/or strong backing by the arm of the State.

Are Catholic bishops infallible?


How do I Configure Search To Remove Student Results?

Question: Hello I would like to know how I can remove student onedrive Results appearing in search . I am using SharePoint 2013 Online with O365. Staff and Student share same tenancy. Is there way to block students one drive appearing in SharePoint search.
Answer: I think this can be achieved by creating the crawl rules in Search Administration where you can restrict the contents that to be shown as part of search results  .
Please refer this for more info: https://technet.microsoft.com/en-us/library/jj219686.aspx
Comment: I am using SharePoint Online 2013 . I don't have the option to acess Search Administration
Comment: Yes to configure this you should have the access to SharePoint Online Admin page then you can try with configuring the crawl rules, hope your SharePoint Online Admin can help here.
Answer: SharePoint Search does not pick up OneDrive search results if those OneDrive files and folders are private to each user. Same in Delve. Both honor security trimming - which means you only see files you have access to. If students shared their content with others, then it is a different story. Agree with previous comment, you will need to configure/customize search center for this.


RMI, EJB and callback

Question: Is it possible for a client to pass an RMI object as an argument to an EJB so that the
EJB may callback the client?
Answer: You'd need to pass the connection details in the call to the EJB and have the EJB make a connection to the client-side RMI server.
My advise would be to use messaging and a temporary queue for the asynchronous behaviour it sounds like you're trying to achieve...
Answer: No.  Remote objects cannot be serialized and moved to other locations, since the connection to the remote object itself is transient in nature.
It may be possible to use some kind wrapper object that can be serialized and will reestablish the RMI connection once sent to the EJB.

RMI, EJB and callback


Does Visual Studio 2010 work with SharePoint 2007?

Question: Does Visual Studio 2010 work with MOSS 2007?
Answer: No Vs2010 only works with SharePoint 2010. For Moss 2007 you'll need VS2008
Answer: You can however use SPVisualDev that works with VS2010 for SP2007 solutions.
Answer: All of the Templates in VS2010 are designed for SP2010, and likely won't work for SP2007 without modification.
I know of no reason you couldn't create a project for SP2007 and do all the work that VS2010 does for SP2010 manually (Build the WSP, generate various Xml files), OR use WSPBuilder, or another 3rd party tool.
Edit: Johan is correct, SPVisualDev is what I was thinking of.


Incorrect tooltip for suspended users

Question: While trying to accept an answer during suspension gives a tool tip

suspended users can't vote

shouldn't that be

suspended users can't accept answers
Comment: [Accepting is a vote](http://data.stackexchange.com/stackoverflow/query/278573)
Comment: I'd argue that accepting an answer is analogous to a vote.  Perhaps you're right in saying that it should be worded a little better, though.
Answer: Almost everything you can do to a post beyond writing or editing it is technically a vote. Well, less today than it was previously after we overhauled flags quite a bit, but that text is reminiscent of the time that it was. When you flagged something, you basically voted to say a post was [whatever flag said], just like you'd vote to close, reopen or delete. This actually makes a lot of sense when a consensus is meaningful when it comes to the system doing stuff based on a consensus.
I'd be for changing it to:

Suspended users can't vote on or accept answers

But even though we hand out way more than we've ever handed out in the past on Stack Overflow, suspensions are still very much an exceptional situation. The guidance sufficiently conveys "You can't do this because you're suspended".
We're going to be a little more .. selective when it comes to minor copy changes because of the internationalization effort. Every time we add or change a string in English, we task volunteer translators on several sites to review and possibly re-translate it.
I'm not saying no, and I'm tossing this into a sheet I'm keeping of minor copy changes that I'm considering for when we send the next batch of strings to trickle back down to the international sites - as suspensions are confusing enough in English. But, it'll be .. a while.
Answer: Accepting an answer is a special vote you have on a question you asked. Technically makes that the tooltip correct.
However, it seems a small change to make and indeed, an updated wording makes it actually clear what you did. I wouldn't bother too much though.
Answer: Accept practically counted as vote - you can use this vote on an answer that you consider to be correct for you - so I believe the wording is good and I wouldn't change it.

Incorrect tooltip for suspended users


How to be kind when you don't like people or the world?

Question: I'm not sure I make a very good Buddhist. The thing is I really don't like people. They constantly disappoint me. I find most people to be so stupid. Take for example half of America and the idiotic orange leader they have elected. What kind of idiots would elect a bigoted narcissistic fool such as this?? I don't care if it's "wrong speech", I'm not going to be polite about it, the man is a delusional scumbag and such a negative force on the planet.   I cannot feel any compassion or kindness for him or his ignorant redneck believers. If someone killed him I would honestly feel glad. Yet a short distance away in Canada there is one of the most compassionate amazing leaders ever to grace the earth.  Go figure.  America seems like hell on earth to me.
Most of the world seems to currently be controlled by dangerous mentally ill people. A lot of the time I dont even want to be here anymore. The amount of money it costs just to scrape by and survive this life now is another reason that I don't want to be here. A life that is sustained by money feels so meaningless. Sure life is more than about money but let's face it without it you die and nobody cares less. It's all so screwed up.
Comment: Some related topics might include "[How can I become less affected by politics?](https://buddhism.stackexchange.com/q/21336/254)", and "[What is the Antidote for a Hateful Temperament?](https://buddhism.stackexchange.com/q/8735/254)".
Answer: What really matters is whether you follow the noble eightfold path and you understand the four noble truths.
Answer: I have answered before on metta threads (where I usually get downvoted) but it is best to start with equanimity towards the world & then move up to metta (when appropriate). Dhammapada states:

171. Come! Behold this world, which is like a decorated royal chariot. Here fools flounder, but the wise have no attachment to it.
58. Upon a heap of rubbish in the road-side ditch blooms a lotus, fragrant and pleasing.
59. Even so, on the rubbish heap of blinded mortals the disciple of the Supremely Enlightened One shines resplendent in wisdom.

If you are enlightened, kindness is merely a natural emotion that eminates from your own freedom of heart & kindness towards yourself in your cultivation of liberation.
Answer: If the whole world is covered in broken glass, you could either try to wrap the world in leather or you could start wearing sandals. Trying to wrap the world in leather is like trying to change people in  the world. Wearing sandals is like fixing your own mind so the outside factors cannot bother you.
If you are overwhelmed by hate, Metta meditation is the one recommended. Once you have your hate subdued to a degree you could move on to Satipattana meditation which will eventually eliminate anger.
Answer: These opinions you have, what is the source of them? What is the source of any opinion? Have you met either man or did you read an article, hear a report or hear someone talking about them in a bar? If you haven't met them, consider how you have relied on intermediaries to form an opinion of two people you don't actually know. Do you trust these intermediaries (tv companies, newspapers, members of the general public)? Why? Meditate on this.

All the world's a stage,
  And all the men and women merely players;
  They have their exits and their entrances,

Consider the double meaning of entrances and exits. What are the entrances and exits of a human being? What goes into the body and via what channels? What is light? What is sound? What is food and water for? What about air? How long can you go without these things? Why?
Comment: Could the person who marked this down explain why. I would genuinely like to know why this would not be a good answer to the question.


Is it counter productive to accumulate a lot of ideas while meditating?

Question: I'm not particularly into Buddhist style meditation but wasn't sure where else to ask. I tend to accumulate a lot of random ideas that filter in and after my session I jot them down - is this counter productive to an effect meditation? I use the Muse brain sensing headband and still stay in a fairly calm state of mind.
Comment: i did this on retreat and immediately forgot them all. probably best to do so, even if you can't help thinking
Comment: mind and brain are not synonyms.
Answer: There are two types of meditation available in Buddhism. Samatha and Vipassana.
In Samatha, you should concentrate your mind into one target sense. The target sense can be inhale and exhale witch is popular as Anapanasathi. There are more Samatha meditation methods which are targeting difference target senses. Kasina meditation and Asuba meditation are some of them. There you continually get that target sense into mind without allowing any idea, sense or feeling other than that. Then you will feel your mind become more powerful and very high state of calmness. actually Samatha is like sharpening your weapons against a war.
As Buddhists, our main intention is to attain Nibbana. So after performing Samatha we look at the uncertainty of the body and mind. Here what we are doing is not generating ideas. but perform root cause analysis on uncertainty of body and mind. actually wipassana is like use your weapons against enemy.
you cannot get good results if you are not following sila, at least five precepts. My friend, Use five precepts not Headbands.
Answer: Accumulating ideas is what happens when we meditate. When we distance ourselves from the mind, we can watch these ideas in a detached way. For that we have to step back from all the influences inside our mind. When you have reached a place within where you can be quiet, then you can observe these voices to see what they are. Watch them in detachment. If you know Buddha's teaching on not‐self it will be easier for you to step back and do the watching. Not only ideas but feelings of pleasure and pain too will come and go.
Another kind of ideas is perceptions, or thought‐ constructs. You can observe these too, to see the influence they have over the mind.  Then you will know what type of ideas to encourage, and what to get rid of. Again if you know the Dhamma it helps. Dhamma contains all sorts of useful and encouraging ideas. You can broaden on the ideas of loving kindness for example. You can start with goodwill for yourself, then expand into goodwill for other people etc.
What has to be gotten rid of are the burdensome ideas - the burdensome notions the mind,  Such ideas will make you react this way, to think that way. Once you identify them, you can let go of them. You do not have to entertain ideas of greed or anger that come in to the mind. Also never allow lustful or angry or cruel ideas to arise within you. With earnest effort, you can straighten out any crooked and bent and shifty ideas.
Thanissaro Bhilkku once had the following to say about ideas:

"We hold on to ideas even though they have proven themselves again and again and again that they don't work. It's like that famous story about Nasruden eating a whole bushel full of peppers and crying. Someone asked him, "Why do you keep eating peppers when they make you cry?" And he responded, "Because I'm looking for the sweet one."
  You may have some ideas about what should work, but when you find that they don't, you drop them. You're not attached to them. "
Comment: This person (@user8717) is not into Dhamma. That is why I was careful not to mention in a bit more detail about these other meditation types such as...  reflection on the qualities of the Sangha, Meditation on the recollection of death, Nine cemetery contemplations, Meditation on five groups of clinging, Meditation on postures of the body, Altruistic-joy meditation, Meditation on loathsomeness, reflection on the qualities of the Buddha, Loving Kindness Meditation, meditation about heavenly beings, meditation about generosity, meditation about virtue, etc. etc.
Comment: What kind of ideas does Thanissaro Bhikkhu mean? I mean sometimes they work. You can have all the ideas in the world and still not worry about them i.e., attach.
Comment: control your mind..
Comment: @BlackFlam3 It depends on the type of meditation that you do. For Breathing Meditation (Anapanasati) it is counterproductive.  For others – it is about ideas. Eg. Sanghanussati , Dhammanupassana, Maranasati, Asubha, Buddhanussati, Metta, Karuna, Upekkha, Mudita, Ayatana, Walking Meditation, Nava Sivatika, pancha nivarana, Caganussati, Silanussati, Anitya, Dhathu Manasikara, Vipassana, Iriya patha, Devatanussati, panca upadanaskanda, etc. These are about 'Yoniso-manasikara' - thinking through (Contemplation on) Dhamma.
Answer: I looked up Muse Brain Sensing Headband and have to say that you cannot practice Buddhist meditation while using such a device for at least two reasons:

You should always try to be as secluded from sense impressions as possible (in formal meditation). Listening to sounds or music while sitting is counterproductive and not a Buddhist style of meditation.
As I understand it this device generates pleasant sounds when it senses less movement in the head (not in the mind!) and unpleasant sounds when the activity in the head increases. This is problematic! You're reinforcing judgement, thinking it is good to have a calm state of mind, bad to have an agitated state of mind. And also mixing up bodily and mental sensations (by mistaking the activity in your brain with the activity in your mind).

Since you asked about accumulating ideas, I guess that you don't have a clear and comprehensive instruction to follow. And since you asked this question on the Buddhism Stackexchange, you'll get the Buddhist explanation of meditation :). In Buddhism, the meaning of the word 'meditation' may differ from what you associate with it. A common misunderstanding is that you practice meditation in order to get calm. You don't. You practice in order to get wisdom. This can be done by using a calm mind, but only as a means. The following is a good, practical instruction based on the original Buddhist teachings (over 2500 years of people practicing it has proven it works):  How to meditate.
Answer: Talking from a Zen perspective and Zazen meditation, one should just sit and stay with whatever comes up, and accept without judgment whatever rises in consciousness. Having a measure of how good or bad your mental state is, is judging what is coming up in the moment, so not supportive of Zazen.
Also as someone has mentioned and related to what I just said before, judging your mental state will lead to clinging to "good states of mind" and aversion of "bad states of mind" which will lead to suffering, see the 2nd Noble truth:

Dukkha, and repeated life in this world, arises with taṇhā, "thirst,"
  craving for and clinging to these impermanent states and things. This
  craving and clinging produces karma which leads to renewed becoming,
  keeping us trapped in rebirth and renewed dissatisfaction

Citation from Wikipedia
About accumulating ideas, in Zazen the invitation is be aware of thoughts but not to engage with them and let them pass,so I believe there is nothing wrong with jotting them down after the session, some people even keep a log of notes, etc to discuss with the teacher.
Answer: Of course, there is nothing wrong with accumulating ideas, especially if they turn out to be useful. And if the head band helps you do that, why not use it? But there can be no doubt that you are not practicing Buddhist mindfulness meditation as it is described in the Satipatthana Sutta. Indeed, the meditation you describe prevents mindfulness from doing its job. I have just published a book called "How Mindfulness Meditation Works". It will be available in a month or so.


Campagnolo Athena 9 speed compatibility?

Question: I own some NOS shifters, Campy Athena 9 speed, from 1998 i guess.
do you guys know if I can use it with any campagnolo front/rear derailleur?
how do I know what is compatible?
Answer: This page is incredibly useful for figuring this stuff out. Campy shifters with just about any front derailleur should be fine since they have micro trim.
http://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Gear-changing_Dimensions#REAR_SHIFTING_TABLES
Answer: You will need a pre-2000 rear derailleur as the cable pull ratio was changed in MY2001 and the lever / rear derailleur movement artio, if you use a current 9/10s RD will not give you accurate indexing.
You can use and front derailleur from Campagnolo describing itself as "9/10s" compatible but you may find that you need to set it up with more care as the most recent 9/10s FDs have a different movement to cable recovery ratio, too - this is not such a big problem on the FD as it is on the rear, because you are not aiming for such exact index points but it can still be a consideration.
As the main Campagnolo factory-appointed Warranty and Service Centre for the UK, we can assure you that the above answer is correct.


Is there an organic way to remove wild strawberries from a lawn?

Question: We have a variety of areas in our lawn where the wild strawberries are consistently killing our grass. Is there an organic way to control these? We have been fairly successful at tackling other weeds (Dandelions/Crab grass) by letting the grass grow longer and using pre-emergents, but this has been a bit out of control.
Comment: Just a quick question, are you sure they are strawberries? There is a weed called Mock Strawberries and removal is not as simple as getting the rhizomes. The easiest way to tell is the flower. Strawberries have your typical rose flower, with a yellow or green cone in the center, mock strawberries have tiny yellow flowers more reminiscent of sorrel flowers. Both real and mock strawberries produce fruit that look alike, and both are edible, but mock strawberry fruits are rather tasteless.
Comment: This sitehttp://www.gardensalive.com/product/not-so-wild-about-wild-strawberry/you_bet_your_garden gives detailed instructions on manual removal.
Answer: Apart from digging them by hand, either on your hands and knees or use one of the weed diggers available, for use when standing. Depending on your situation/location/size of lawn; would keeping chickens on the lawn be an option for you, they will scratch around and clear the lawn of everything including the grass for you to re seed later.
Rake the lawn to comb the runners and then cut with mower very short.  That will remove the easy bits and expose the rosettes of leaves for you to more easily target the plant for removal.
If it's really bad and you wish to have a lush green sword do you want to go down the root of returfing? In which case, remove and compost the top layer, returf, and then once composted down, your previous top soil and turf, will be a more enriched top soil to be used as a top dressing (hopefully free of strawberry seeds).
Answer: Depending on how big your area is, vinegar (acetic acid) could be a option.  You can test household vinegar in a small area to see how well it works; however, since wild strawberry is a perennial, you will probably need a concentration that's greater than the household 5%. (5% household vinegar works better for small, annual weeds.)
The stronger solutions will be labeled as herbicides - it's required by law to be labeled as such. Follow directions on the label.
Please note:

Vinegar solutions greater than 5% are considered hazardous and
greater than 10% can burn your skin or cause serious damage to your
eyes, so wear protection and follow the directions on the label.
Spray it directly on the plants so that they are completely, I mean
completely, saturated.
The vinegar will kill the grass too.  However, you can take a large
plastic lid or plastic tablecloth or something similar with you
to cover the grass where you might over-spray.
Spray on a sunny, windless day. The hotter the day the better.
Test a small area first to see if it works.
If you want to increase the effectiveness of household vinegar, add salt:
1 cup/gallon vinegar. Keep in mind, a lot of salt in your soil will
change the pH of the soil. (See the tip above.) You can also add 1
tablespoon dishsoap to help the salt and vinegar solution cling to
the plant.

Sources:
Purdue University https://hort.purdue.edu/ext/vinegar.html
University of Illinois Extension: https://web.extension.illinois.edu/cfiv/homeowners/070913.html


Late Payment by employer

Question: I have recently joined an middle -size organisation about 2 months ago.
The employer has not yet paid the amount of my first month.
The salary cycle is from 25th to 25th of every month, with a week salary in advance.
Its going to be 2 months in next 4 days the employer has not paid a single penny.
Since the HR has resigned the month I joined, I have asked the accounts dept. regarding the same, they didn't provided any appropriate response.
I have also asked my manager twice regarding the same. He made some commitments regarding the date the salary will come, but that was untrue.
Please help, What can I do about it?
Comment: What country are you in?
Comment: Is it just you, or have your colleagues had similar experiences? Knowing whether you've slipped through the net, or there's systemic incompetence / financial difficulty, will help determine what's the best line to take.
Comment: Yes, ask your colleagues if they have the same problem with payments. It can mean the difference between finding a mistake in the payroll system and the entire company being entirely in a bad financial state.
Answer: Red light
Actually, your title is incorrect bcause it's not late payment, but no payment.
Assuming the company is not a scam (which happens, but more often by temporary jobs on field), it's a signal of huge financial problems. You were promised to get money on some date, and probably they've meant so, but they were unable to do that.
You should immediately talk to other workers about the issue and talk to the management, and make sure it's a serious talk. If your company will go insolvent, you may never see your money! (the state will collect unpaid tax first, and workers will be paid only if anything is left). While there's no guarantee you'll become money they already owe you, it's still better than working effectively for free the next few months.
Answer: From the details in your post, I'm guessing the company doesn't have enough money to meet pay-roll.  I would do the following.
Either discreetly visit other employee's desk at the office, or contact them via personal email/phone to determine if they have not been paid.  If they have not, round up as many as you can quickly.  If your at the office, get 8 or 10 people together.  If you're not, as many as can be rounded up in an hour.  Visit HR (or the CFO if HR has quit), as a group and explain the situation.
Be polite to the CFO.  Hopefully the company has money and you will all get paid (unlikely), or he or she will find some money to placate a large percentage of the staff (still kinda unlikely).
From here you have 2 options.  Option 1 is simply to look for another job and not show-up again for work.  Do not formally resign as you can answer that you are currently employed during interviews, and formally resigning will make harder to gain access to the building so you can keep the pressure on HR/CFO.
Option 2 is to get as many employee's as possible to "walk out" until they are paid.  If you can get the majority of the "rank and file" folks to walk out, you've essentially shut-down the company.  I don't give this a high probability of working either as I don't think they have money, but you may be able to bargain for a reduced salary, which will give you some breathing room until you find a better job.
Answer: Act now, not later
You should discreetly ask others if they are having problems similar to your own. Typically asking doesn't need to happen. When someone doesn't get paid they tend to be VERY vocal about it. (still I'd ask around)
You might also want to seek legal counsel in case you have protections should this end badly.
I'm alone
If you're the only one with this issue it's best to make it clear, you've been working and have yet to get paid. You've been promised this would be resolved and it hasn't. You want to continue working for the company, but until you're paid you can't reasonably continue working.
You might be fired at this point, if that happens they probably had no intention of paying you and you were getting screwed. If it's been one huge mix up then they'll try to rectify it ASAP.
You should also start job hunting now. A lot of things don't add up here if everything is on the up and up, you have to protect you. If they can get square with you and convince you everything is fine just the HR departure left things a mess, no problem stick around. Anything short of that... I would not stay if were me, just too many red flags.
If there are others
In the event you are not alone this is a HUGE issue! It's also likely a sign your company is in dire straights and can't make payroll! (which is arguably the single most critical operating expense, you fail to pay your people bad things happen, simple as that.)
No matter what plan of action you take from here one thing you should do is start pursuing a new job. Your company is likely on it's last limb before imploding which leaves you unpaid and pissed off. (unless you're REALLY lucky)
Generally speaking things get to this point in one of three ways.

Management is incompetent and were blind sided to find their piggy bank empty
Management is aware of the issue and informed the staff things are tight and is just trying to survive the slow season.
Management is aware of the problem but trying to keep it on the down low

Based on what you've said I'd guess the third with a small chance it's the first. If it's the first probably best to just move on as likely this ship is already beyond saving, therefore; there is no money to pay you with.
If it's the third this means management is probably going to do what they can to save their butts knowing it ends one of two ways. They turn things around and it looks like a payroll "glitch" that was troublesome, or they fail to save this sinking ship and you're left high and dry with months of wasted effort and nothing to show for it...
In the slight chance it's the second... that's a dangerous call with potential... When companies are on their deathbeds and by some miracle manage to climb back into good health those who stick with it tend to do VERY well, however; most of the time when a company reaches this point it's way beyond the point of saving, and once again you lose.
Summary
Take what actions deem necessary to cover your bases and hopefully get paid, but in the way of red flags you've got enough to make a respectable slalom. Probably best to just pursue other opportunities while trying to get whatever compensation you can for time wasted. (hopefully I'm completely wrong and the HR person quitting just caused hell and you're unfortunately just caught in the middle of it)

Late Payment by employer


How much force can the landing gear of a Piper Arrow withstand?

Question: I'm currently working on my CFI-A in a Piper Arrow and i was wondering if anyone knows how much force the landing gear can withstand? The reason I ask is because I have never been asked this question and I know there has to be a concrete answer out there. For example, aircraft in the Navy that need to land on a aircraft carrier have to go through a series of landing gear stress tests.
Comment: Its not a requirement for GA aircraft to test landing gear systems to identify the point of failure. It would be difficult anyway, there are a lot of factors that go into it. Age of the aircraft, corrosion, previous hard landings, etc. There is no magic number here. Navy aircraft have that because they have highly specialized landing systems which are maintained to a high standard.
Answer: The Arrow is certificated under 14 CFR 23, and the landing gear loading limits are specified in the ground loads and landing gear sections. I don't know much about this subject and the regulations are fairly technical, but 23.473 apparently defines the load limit. I don't really understand it myself, but it looks like the landing gear has to support at least 2.67 times the aircraft's weight in a landing:

No inertia load factor used for design purposes may be less than 2.67,
  nor may the limit ground reaction load factor be less than 2.0 at
  design maximum weight, unless these lower values will not be exceeded
  in taxiing at speeds up to takeoff speed over terrain as rough as that
  expected in service.

In reality they should be designed to withstand more than this, as there are manufacturing uncertainties which can affect a component's performance.
Someone who's actually an engineer could probably explain it better (or correct me, as the case may be!).
As for testing, my limited understanding of the certification process is that the manufacturer has to prove to the FAA that the requirements in part 23 have been met, but there's no specific way of doing that. And indeed, 23.721(c) says:

Compliance with the provisions of this section [i.e. the landing gear section] may be shown by
  analysis or tests, or both.
Comment: Thank you so much for this response this was very helpful!.


How does commercial whole grain bread stay fresh for so long?

Question: Every recipe for whole grain bread I have tried has the end result that the bread turns very hard within an hour of baking. I'd like something I could eat over the course of a couple days (breakfast toast and such). The 100% whole wheat bread from the store lasts two weeks - how do they do it?
Comment: There is a BBC show called "E Numbers: an Edible Adventure" which has a section addressing this question (I think in the second episode).
Comment: Can you define "hard"?  Do you mean all the way through the loaf - even if you cut into it?  Just the crust?  My bread machine loaves go stale quickly, but I make up for that by eating it. :-)
Comment: 1. What recipe are you currently using?
2. Have you tried putting fruit or something else moist in there?
Answer: Industrial breads use 'dough conditioners' that soften the dough and make working with it easier. You can buy such mixes online, here for instance, and I've seen them for sale in
natural food stores and the like. Other things that might work are adding a starch or a fat, or heat treating some of your flour in the microwave (a minute for a cup, don't do this to all the flour, it destroys some of the gluten). Guar gum or xanthan gum will help to keep things moist as well.
I've never used these techniques, so some experimentation might be necessary. Store bread in plastic bags as soon as it cools, and don't slice right away.
Comment: For that fats: for me, adding Joghurt works really well! Buttermilk made it a little TOO moist. That's whole wheat bread just from flour, water, yeast, salt and yoghurt, baked in a bread-baking-machine. Also, when having a moist bread finally, be careful about the plastic -> When the read sweats moisture, you invite mold.
Answer: They do it via liberal use of sugar, mainly, as well as a host of industrial techniques that are simply not replicable in the home kitchen. Bear in mind that such breads are made for longevity and not flavour.
If your bread is going that hard an hour after baking, you may well be overcooking it.
Answer: Most bread is made from wheat and / or barley flour. A "hard" flour contains more wheat.
The higher the proportion of wheat flour, the better it tastes (especially the crust) but the poorer its keeping qualities.
Commercial bread that keeps for a long time has more barley flour. In addition, some bakeries add a little vinegar to the dough after proving, which also makes the bread keep longer.
Answer: Another trick is to add more fat. I have been told that harder fats (butter, lard) are better this way, but I normally use olive or rape oil. (About 5% or flour weight.) It impedes the rise a little bit, but not too bad. (I think it interferes with the gluten formation, but I'm not 100% sure how.)
Comment: You probably mean Canola rather than rapeseed, I'm thinking, since true rapeseed can contain up to 54% erucic acid. Canola came from rapeseed (but true rapeseed is toxic, whether or not Canola is; Canola is only allowed to have 2% erucic acid in the USA and 5% in the EU). I'm guessing oil impedes the rise because it's antimicrobiaI (except for microbes that do better with oil; you'll notice that peanut butter, which is high in fat/oil, doesn't ferment on the counter, though; rising bread is pretty much fermenting dough), but I could be wrong about that being why.
Answer: They use ground up bird feathers to make bread stay fresh for longer
Comment: Even if they are using some substance derived from bird feathers, the way you state it is terribly misleading. If you mean cysteine, eating it compares to eating feathers about the same way as eating sugar compares to eating beets. And before you say that everything in bird feathers is icky, let me remind you that your own body, and steaks, and tofu, are all full of cysteine too. It is a very common compound, and as essential to our body as vitamin C.
Comment: Also, cysteine is a reducing agent. It allows gluten-forming compounds to denature and link together faster, it has no effect on the shelf life of the product.


Is there a way to find the direction to land in the middle of an ocean?

Question: Can I find the direction to land when I am in the middle of the ocean and can not see any land?
This is a theoretical question.
Any method that doesn't use over-technical methods such as smartphones and GPS will do.
Example: Ocean current direction, wind direction, fluctuation in temperature, etc.
Answer: Your best bet without modern tools would be a sextant and the proper maps for celestial navigation.  This is a time-tested and old method of navigation no longer in regular use, but it probably doesn't meet your "no over-technical methods" criterion as it requires a tool, maps and knowledge of its use.  If you only had knowledge of the constellations and a few stars (e.g. Polaris, the Sun) you could probably figure out what region of the globe you were on and make a best-guess as to the direction of land.
You might be able to do a similar guess with surface winds, ocean surface flow and temperature to get a rough location but if any synoptic conditions are masked by storms or local anomalies then this will likely not work.  There are some semi-presistent weather features (e.g. the Bermuda high) that you could use along with knowledge of the general circulation that could potentially help you out.  You could make similar estimates with ocean current and temperature (if you have equipment to measure this), but I think this would only provide regional benefits and may not work everywhere you could find yourself.  These would also be marred by tropical convection (e.g. in the wake of a hurricane sea surface temperatures will be cooler than normal) and other storms.
Answer: An experienced Polynesian navigator would be the best person to answer this question but as a qualified ocean yacht master and having taught Coastguard courses including navigation, I believe there is some evidence to show that within the trade wind latitudes, where the winds are often steady and constant for extended periods of time; the refraction patterns in the waves which result from waves combining after passing islands, may be detectable beyond the horizon.  How far that is depends on the height of eye of the navigator and the height of the island. (the horizon at sea level in a typical Polynesian canoe would be around 4 Nm.)
The width of the island as well as the wavelength of the refracting waves would also affect how far the refraction pattern travels or extends beyond the island.  However, I believe Polynesian navigators may well have observed the wave motion and steered their vessels in the direction of the "calm" or flatter wave areas, thereby leading towards a not too distant island. But in my experience, observation of wave motion or direction is very difficult to view from the deck of a small vessel, so I do not believe it is a method that would be useful or possible beyond even as far as 50Nm from even a large islands such as New Zealand.  Besides which, the Polynesian catamarans, are not able to sail close to the wind so following a windward course would require a lot of tacking, to and fro in order to stay in sight of the calmer sea pattern.
Answer: The polynesians used primitive star charts, which is OK for latitude, but tells one nothing about longitude. The latter is the age-old problem that faced sailors for centuries, if not millennia, and which cannot be resolved without sophisticated instrumentation. The Polynesians probably supplemented their navigation with other clues, such as bird migratory tracks, current temperatures and strengths, cloud frequency and, as Tony says, wave refraction features.
Comment: Right, you need to know the time to determine the longitude. Also, over submerged seamounts the water colour could appear different.
Comment: Seamounts are also biological hot spots, attracting birds, dolphins and whales (and fishers). https://en.wikipedia.org/wiki/Seamount#Ecology http://oceana.org/sites/default/files/reports/seamounts_gorringe_bank_eng2.pdf#page=10
Answer: If you know your current position, and the position of the land youʻre headed toward, then you only need to be able to determine direction and keep track of your progress (perform dead reckoning).  You can determine direction from some key stars (the sun rises and sets near east and west, and the exact direction depends on the time of year).  The North star is always north, and Mintaka in Orionʻs belt rises due east and sets due west from every latitude on Earth.  Other starsʻ rising and setting points depend on your latitude to varying degrees.  You can roughly check your latitude by the height of Polaris, the North Star, above the northern horizon, or by the height of the upright Southern Cross above the southern horizon.  There are also certain pairs of stars that point very nearly due north or due south when they are stacked vertically.  For example, Dubhe and Merak when aligned vertically are nearly directly above due north.  They also act as a guide to locating the north star.
If you donʻt know your position, or the position to land, then you need some kind of indicator from the land itself.  In the trade wind belts, there is often a stationary pile of clouds over high volcanic islands, whereas most cumulus clouds float freely downwind.  It is alleged that clouds directly over coral atolls with central lagoons may sometimes reflect a green color from the lagoon.  Seabirds such as the brown noddy and fairy tern that are known to sleep on land at night can be used to locate land, since they head out to sea in the morning to fish and fly back at night to sleep.  That gets more complex when they make multiple fishing trips to feed their young.  Lines of rubbish and organic matter (leaves, sticks) may indicate land is nearby.  If you know the prevailing direction of the swells or can calibrate them with the rising or setting sun or recognizable star, swell directions typically donʻt change quickly in under 24 hours.  If there are multiple swell patterns with the exact same period (time between swells), that may indicate that one of the swells is a reflection off of an island of the other swell, or a refraction of the original swell bent by the shallow water around an island.  This was a mainly Marshallese island technique.  They were noted for their wave pattern stick charts, which were apparently more used for studying and teaching than actual use during a voyage.
We, The Navigators by David Lewis chronicles much of this.


Best way to handle different stakeholders?

Question: There are different stake holders like the quality team,client, peers, sub-ordinates, seniors.
As a manager, do we need to have a strategy to handle different stakeholders? Sometimes we might not be able to be good to everyone. In such a scenario, whom we need to give priority and based on what?
Answer: It is not subjective at all.  It is the result of your stakeholder analysis, a necessary analysis that feeds your communication plans, your training plans, your stakeholder participation plans, and likely many other things.  It is one of the most important things you do for your project and this is not an area where you want to go on the cheap or try to save money or even try to avoid doing.  It is a must.
You need to segment your stakeholders into categories of similar attributes.  Then you need to ask the questions like who are they, what do they need, what do we need from them, how will they be impacted, are they likely supporters or detractors of this project, what do they need to hear, what do we need to hear from them.
You are right that not all stakeholder segments will benefit from the project.  That is very unlikely.  One or more stakeholders are going to get impacted in an unfavorable way and part of your plan needs to include how to manage that, including bulldozing them out of the way (as atrocious as that might sound).
Bottom line is, your stakeholder management activities need to be as complex and diverse as your stakeholder community is.  Anything less you are increasing the odds of failure.
Answer: As part of your project start-up documentation, you can (and should) describe what you will deliver to satisfy each of your stakeholders. I would normally include this in the Project Initiation Document (PID), which must be signed off by the principal stakeholders.
For each stakeholder, you should define the relationship, and what you will deliver to meet their requirements. It will be a short description for some, and a much more extensive write-up for others. In each case, you should be identifying what you will do, and what you won't -and this should include your communication strategy for that stakeholder, as well as "hard" deliverables.
You can also supplement this with a RACI matrix that defines Responsibility, Accountability, Consultation, and Information - see this link or this link for a high level overview.
In terms of priorities, that will vary according to the project. For example, in a defence or medical project, you may have quality as a very high priority, whereas in banking the focus may be more on regulatory matters. In some cases, the customer experience may be highly significant, and in others, cost control may be at the top of the agenda. Discuss this with your project sponsor and gain his or her agreement. That way, you both know what is expected.
Answer: The project sponsor is generally the most important stakeholder to your project. Without the sponsor, the project wouldn't exist (from a funding/empowered to use resources perspective) and the project wouldn't have a reason to exist (the project exists to provide a result for the sponsor -your customer).
If you have trouble working with a particular stakeholder group, identify why that problem exists and address it.
Answer: First of all, go talk with them. How do they wish to be informed about the project? Do they want your regular status report? Do they wish to be informed about scope progress? The lot or only that one feature one of them has requested? Ask, then decide (and document) how to keep each of them in the loop.
Regarding priority, that depends upon their "stake" in the project. But it should be discussed and agreed by your SteerCo how you will handle priority issues.
Answer: For you to prioritize stakeholders you would need to connect them to enabling your project's goals/sub-goals.
Prioritize your project goals and you should have a prioritized list of stake holders
Answer: There are three important things to consider:
<code>What is the formal process?  As mentioned by @lain9688 you should
have some sort of Project Initiation or kickoff document.  This
should include who each party is, and for each activity or
deliverable, what their level of involvement is.  (Own?  Contribute?
Veto?)

What is the real capability?  Many times Statements of Work or
Initiation Documents are written that don't fully capture reality.
As a good project Manager you need to be on top of where the
breakdown is.  Will your client really ever pay for Change Requests?
Will an external Design Authority really be fast enough?  Will there
really be enough time for the project team to analyze all the new
requirements?

Lastly, what is the relative importance of the stakeholders.
Usually the most important is the one that's paying, but sometimes
others have veto power, or aren't cooperative.  Many times someone
will say, "I'm paying for this, my team will honor all the industry
standards" but then their subordinates want a million free
customizations.  This is a big challenge in project management.
</code>
Good luck!


Shading: Phong vs Gouraud vs Flat

Question: How do they work and what are the differences between them? In what scenario should you use which one?
Answer: Flat shading is the simplest shading model.  Each rendered polygon has a single normal vector; shading for the entire polygon is constant across the surface of the polygon.  With a small polygon count, this gives curved surfaces a faceted look.
Phong shading is the most sophisticated of the three methods you list.  Each rendered polygon has one normal vector per vertex; shading is performed by interpolating the vectors across the surface and computing the color for each point of interest.  Interpolating the normal vectors gives a reasonable approximation to a smoothly-curved surface while using a limited number of polygons.
Gourard shading is in between the two: like Phong shading, each polygon has one normal vector per vertex, but instead of interpolating the vectors, the color of each vertex is computed and then interpolated across the surface of the polygon.
On modern hardware, you should either use flat shading (if speed is everything) or Phong shading (if quality is important).  Or you can use a programmable-pipeline shader and avoid the whole question.
Comment: On modern hardware, I'm unaware of hardware-based Phong modes. Also, incidentally, for programmable shaders, which by now are ubiquitous, people almost always use microfacet-based BRDFs.
Comment: My point is that the speed increase of Gourard over Phong isn't enough to justify the loss of quality -- modern computers can (or at least should) be able to do both in realtime.
Comment: The way you phrased it, it sounded like there is fixed-function Phong functionality, while I don't believe there is. Separately, you say you should use Phong "if quality is important", but Phong is actually a poor quality BRDF model. By some measures, worse even than Blinn-Phong, which is what hardware Gouraud shading uses to shade vertices.

Shading: Phong vs Gouraud vs Flat