Change from waterfall to agile

Question: I have been working on different kind of software projects implementation using the water fall methodology. now some of my clients want to shift to agile methodology. what do I need to take into consideration for such a change and what steps needed to start follow up with the new methodology though some client will remain working with using the waterfall way but some clients are insisting on the agile way.
Comment: Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer.
Comment: How big is your team? Is it dedicated to one client?
Answer: A good way to think of the shift from waterfall to agile is:
Waterfall: We plan as much in advance as possible and do the work following that plan
Agile: We anticipate change happening and as a result we want to either have flexibility in our plans or we want to keep our plans short (iterations)
When your customer asks for agile delivery they mean they want to see an incremental delivery that allows them to give feedback as the work is being done.
Answer: Agile and waterfall are not methodologies. Waterfall is a kind of project lifecycle whereas agile refers to a more general approach to organization and productivity using techniques which emphasize practices like iterative, incremental and continuous delivery, self-organizing teams, customer collaboration and responding to change.
I suggest you could start by reviewing some of the practices associated with Scrum and Kanban - two of the most popular frameworks associated with agile ways of working. https://www.agilealliance.org/agile101/
For software development frequent delivery is key. Aim to deliver working software every week or even every day, allow people to use or review it and then use their feedback to improve future iterations of the product.
Comment: Thank you @nvogel for your reply. In my situation i work on implementation of enterprise financial solutions that already developed and it require configuration, parameterization and some additional customizations to satisfy the client business need. the difficulty here is that, this kind of project used to be planned in the following way a business requirement workshop, implement the requirement , UAT acceptance ,then go live. but how to apply that to agile method. how to know that it's the time to go live with the project.

Change from waterfall to agile


Person versus People

Question: When is the proper time to use the word "persons" in a sentence instead of using "people"?
Comment: This article may help you. http://www.dailywritingtips.com/people-versus-persons/
Answer: Michael Swan (Practical English Usage, 2005.524) notes "Persons is sometimes used as a plural of person in official language" (my emphasis added). This supports my own view that we need never use persons in our own personal or business life. Leave it for the lawyers and law-makers to write such titles  as The Value Added Tax (Vehicles Designed or Adapted for Handicapped Persons) Order 2001 (found here).
Answer: I can't provide any sources (at least, not yet) but you might find this anecdote interesting. I can't vouch for its accuracy, but it does make sense.
My wife is a hotelier, currently as a General Manager, and in that industry they often use persons. Naturally, I asked why. The answer I got is that persons is used for individuals. "Twenty persons" is twenty individuals who don't know each other. A single group of twenty would be described as twenty people, but the 'people' is usually dropped so it is "a group of twenty". The reason is that groups and individuals are processed differently so they need different terms.
Answer: I feel the same as Roaring Fish. When individuality is to be emphasized, I will use persons. If the group is homogenous, I will use people.
Comment: Welcome to EL&U. Please note that we are not a discussion forum, but a Q&A site, but you appear to be posting in support of an existing answer instead of attempting to provide a definitive answer of your own. I strongly advise you to take the [site tour](http://english.stackexchange.com/tour) and review the [help center](http://english.stackexchange.com/help) for a better understanding of how the site works, and what goes into an answer.

Person versus People


Criterion for model selection in an AR model?

Question: I would like to smooth some financial time series data under the assumption that the data consists of variable trend and cyclic components plus white noise. I am thinking of applying an AR model to the data, in Octave, for which purpose I have the choice of using the in-built arburg function or code from this github repo.
The model selection criterion available between the two are:

AKICc approximate corrected Kullback information criterion
KIC Kullback information criterion
AICc corrected Akaike information criterion
AIC Akaike information criterion
FPE final prediction error criterion
BIC Bayesian information criterion
CIC - combined information criterion
FIC finite information criterion
FSIC finite sample information criterion
GIC generalized information criterion
MCC minimally consistent criterion

where only AIC and AICc are common to both, which has implications for my choice of which to use.
My intended use is to automatically fit an AR model using one of the above criterion and then use the coefficients on the data to smooth it such that the residuals are as theoretically close to white noise as possible. This fitting would be carried out in a sliding window of fairly short length ( @ 50 data points max? ).
Given this requirement, which criterion would provide the closest fit to my assumed model? Parsimony in the coefficients or their interpretability are of no concern.
Answer: Since you are using small windows it would be better to use criteria that don't overfit (e.g. I know aic overfits sometimes). However, I would recommend to apply all and choose the model order based on the majority vote.
P.s can't you estimate them by yourself? Extract the errors and apply the formulas for each criterion


WebSphere 8.5 Application Installation Directory

Question: Where in the Admin Console can I find an application's installation directory?  I have installed applications but I have no clue where they were installed to.
Answer: I found it after some hunting.  I went to "Applications", "Application Types", "WebSphere enterprise applications".  Then clicked on the application.  Then clicked on "Application Binaries" and it was right there.
Then I took the variables and find the values in "Environment", "WebSphere variables"


Is there a way to programatically create a commerce coupon fixed amount?

Question: I'm using the Commerce Coupon Fixed Amount module to create fixed coupons, which works fine in the interface.  But I'm wondering if there is a way to programmatically create them.
I'm able to create normal commerce coupons with this helpful snippet of code.
Answer: Using this tutorial and the above modules/code It makes making a commerce coupon fixed amount (or in this case, a gift card) easier to see.
The only difference between making a regular coupon and one with a fixed amount is that the product (gift card product) price needs to be loaded before hand and the amount of the coupon being created upon gift card purchase needs to load the price from that gift card:
<code>$coupon->commerce_coupon_fixed_amount[LANGUAGE_NONE][0] = array(
'amount'  => $product->commerce_price[LANGUAGE_NONE][0]['amount'],
'currency_code' => $product->commerce_price[LANGUAGE_NONE][0]['currency_code'],
);
</code>
Answer: This isn't a way to do it programmatically, but you can use the Commerce Coupon Batch module, which quickly allows you to generate a large number of coupons through the UI, which you can then export to Excel, etc.
It integrates with the Coupon Fixed Amount module.
Comment: @FelixEve No problem, I've done that before myself.
Answer: The code i used was :
<code>      $coupon = commerce_coupon_create($type);
      $limit_length = variable_get('commerce_coupon_default_code_size', 8);
      $coupon->commerce_coupon_code[LANGUAGE_NONE][0]['value'] = commerce_coupon_generate_coupon_code($limit_length);
      $coupon->commerce_coupon_number_of_uses[LANGUAGE_NONE][0]['value'] = 1;
      $coupon->commerce_coupon_fixed_amount[LANGUAGE_NONE][]  = array(
        'amount' => 2000,
        'currency_code' => 'EUR',
      );
      commerce_coupon_save($coupon);
</code>


Protecting a finished wood exterior door

Question: I have a solid wood exterior door, that I had stained and finished by the maker.  I was looking for a way to prolong and protect the finish.  I thought about waxing the door (especially the exterior side).  Any have any suggestions on this ?  I thought just a spray automotive wax would do the trick.
Comment: I don't know for sure, but auto wax sounds like the wrong thing. Think porosity, metal vs wood. I'd wait for a good answer. If there isn't a answer on this by this time tmw, I'll my contractor buddy.
Comment: I was thinking of the auto wax cause thats what the SalesPerson mentioned. I wasn't sure on it so I figured I would ask here.
Comment: "*stained and **finished** by the maker*" What exactly did the finishing entail (ask the manufacturer)? If it's stained it should be fine. Don't use automative wax. To be honest I can't think why you would think to use automative wax, its for metal not wood. [further reading](http://en.wikipedia.org/wiki/Wood_finishing#Comparison_of_different_clear_finishes)
Answer: You mention the door is "finished" by the manufacturer. Can you tell me what type of finish ? Most exterior doors that are stained can be sealed with a product such as spar varnish, or marine grade epoxy. Seikens makes some very good marine sealers that work great on exterior wood doors exposed to direct sunlight. If your door is shaded and protected by a storm door, than  it can be sealed with urethane, however urethane is not recommended for direct exposure to the elements or direct sunlight.
Comment: I am going to contact the manufacturer to find out what explain the finish. The door is on the north side of the property and recessed a couple feet so it doesn't get a lot of direct sunlight. Humidity is high though, being in Houston.
Comment: After you find out from the manufacturer what is on there over the stain, you can decide. Ask them if a poly overcoat will be compatible with their final finish. I would go with urethane as long as it doesn't get hit with a lot of water, ie: rain. Being on the north side, you won't have to worry about UV on the urethane. I have used urethane on many north facing doors , however they are protected by a storm door.
Answer: Look for a automotive, paste wax, especially one that contains a LARGE amount of natural waxes, i.e. carnauba !     ( "Blue Coral" )
Follow application instructions on can ....


Isomorphic Lie algebras

Question: If I have two abelian Lie Algebra $L_{1} $ and $L_2$, then they are isomorphic if and only if they have the same dimension. I would a example
of two Lie algebras(not abelian) that have the same dimension but they are not isomorphic.
Comment: Welcome to our site!
Answer: If you are happy with one of them being abelian, take an abelian one, and a non-abelian one.
For instance, in dimension $2$, take $L_{1}$ to have a basis $a, b$, and $[a, b] = b$.
If you want both of them to be non-abelian, go to dimension $3$, and take $L_{1}$ to have a basis $a, b, c$ with
$$
[a, b] = b, [a, c] = [b, c] = 0
$$
and $L_{2}$ to have a basis $a, b, c$ with
$$
[a, b] = c, [a, c] = [b, c] = 0.
$$
The two algebras are not isomorphic, because in the second one every commutator $[[x, y], z]$ is zero, which is not the case with the first one.
Answer: An interesting example consists of the two real $3$-dimensional Lie algebras $\mathfrak{so}(3)$ and $\mathfrak{sl}(2)$. Both are of dimension $3$, and both are simple. However, the second algebra has a subalgebra of dimension $2$, which is not the case for the first one. Hence they cannot be isomorphic. For more details see also this MSE equation.

Isomorphic Lie algebras


Are there "Aces" in the Star Wars universe?

Question: On Earth, when a pilot shoots down 5 or more enemy aircraft, that pilot is called an "Ace". Is the title "Ace" awarded to pilots in Star Wars?
Comment: IIRC, Corran and another pilot in X-Wing series were given ace titles too
Comment: Yes, for example there is Ace Azzameen.
Answer: Yep.  Details on Wookieepedia but here's the relevant info:

The title of ace or space ace was conferred onto any starfighter or combat airspeeder pilot who had achieved five or more kills against enemy forces in combat. The origins of the title were unknown, but the status held equal import regardless of the era in which it was earned. Many pilots throughout the history of the galaxy earned the title of ace, with many of them exceeding the minimum number of victories by considerable margins. Among the Galactic Republic and later the Galactic Empire, particularly exceptional aces could be given the title of "Tan," which would be used before their full name.
Comment: @DVK the whole x-wing series, among others
Comment: @KeithHWeston - would you mind adding the exact references to the answer? It would greatly improve it (I don't doubt that they exist, that wasn't the point of my comment, sorry)
Comment: Gives whole new meaning to "I'm gonna get a *tan*." ;)
Comment: Canon sources??
Comment: Mostly the Roleplaying game sourcebooks; [Galaxy Guide 3](http://starwars.wikia.com/wiki/Galaxy_Guide_3:_The_Empire_Strikes_Back)
Answer: Yes, I can think of at least one instance where the title of "Ace" is given to pilots. The book is "Death Star" by Michael Reaves and Steve Perry.
A TIE Fighter pilot discusses with his girlfriend his conflicting feelings about becoming a "Double Ace" in one day.
Sorry i can't recall the exact quote.
Answer: In the short (canon) story "Grounded" Senior Flight Engineer Nera Kase repeatedly refers to pilots by their squadron designation and their number of kills. More than 5 and they're an "ace", more than 10 and they're a "double ace" and so forth.

Red Squadron was engaging the surface batteries, now, trying to clear
  the way for Gold One's element. Red Three (Biggs Darklighter, 5,874
  flight hours, triple ace, sixteen confirmed kills) called his target,
  Red Six (Jek "Tono" Porkins, 10,499 flight hours, double ace, fourteen
  confirmed kills) following him in and—

And in Before the Awakening, we learn that Poe's mother was a triple-ace.

It wasn't until years later, long after she had passed away and Poe
  had entered the New Republic's service and become a pilot himself,
  that he began to learn the true scope of her heroism—that Lieutenant
  Shara Bey had been awarded the Bronze Nova for Conspicuous Gallantry
  during the Liberation of Gorma; that she had earned her triple ace
  less than a week later, during Operation: Mynock Bite


DBEaver Vs PG Admin

Question: When I ran a query in Postgres database using the Pg Admin tool it took only 2 SECS ( I can see the parallel workers being used in the plan) but when I ran the same query in DBeaver, it took around 3 MINS to complete (the plan is different and I don't see yhe parallel workers being invoked. Can anybody explain why the difference in these tools? Are the drivers causing the different plan and execution time?. What is the driver PG Admin is using to connect to Postgres database?.
Comment: PGAdmin is written in Python but DBeaver is in Java. PGAdmin is especially written for PostgreSQL whereas DBeaver supports any database with a JDBC connection. I think that this question is on-topic - it's not a shopping-list question and it should **not** downvoted IMHO! p.s. welcome to the forum!
Comment: Regarding parallel workers: http://blog.sql-workbench.eu/post/client-performance-considerations/ but I really doubt that the use of parallel workers can make a difference between 2 seconds and one minute. Did pgAdmin retrieve **all** the rows that were returned? Or maybe just the first 50 rows?
Comment: Thanks for the clarification.Is the PG Admin using the psycopg2 adapter to connect to Postgres ?.
Answer: Not knowing DBeaver, I can only guess: it uses a cursor to process statement results.
That has two consequences:

Parallelization cannot be used:

The query might be suspended during execution. In any situation in which the system thinks that partial or incremental execution might occur, no parallel plan is generated. For example, a cursor created using DECLARE CURSOR will never use a parallel plan.

A different execution plan may be used:

cursor_tuple_fraction (floating point)
Sets the planner's estimate of the fraction of a cursor's rows that will be retrieved. The default is 0.1. Smaller values of this setting bias the planner towards using "fast start" plans for cursors, which will retrieve the first few rows quickly while perhaps taking a long time to fetch all rows. Larger values put more emphasis on the total estimated time. At the maximum setting of 1.0, cursors are planned exactly like regular queries, considering only the total estimated time and not how soon the first rows might be delivered.
Comment: Well I did try setting `cursor_tuple_fraction` to 1.0 to see what would happen but after a restart of pg, DBeaver remained stuck unable to launch a parallel query.
Comment: That may well be. Try to get `EXPLAIN (ANALYZE, BUFFERS)` output for both queries, then we can say more.
Comment: Thanks.  I found a trick to get DBeaver over the line which I'll post as an answer
Answer: I do believe that the diagnosis of Laurenz Albe is correct but, at least for me on pg 11, setting cursor_tuple_fraction = 1.0 did not result in a parallel plan for queries launched from DBeaver.  But what did work was setting the ResultSet fetch size in DBeaver to 0.  Note that DBeaver will fetch all of the results for every query with this setting so you may need to make more use of limit N in your queries when you only want some of the results.
Comment: That confirms my first suspicion that DBeaver uses cursors. Using [`setFetchSize()`](https://jdbc.postgresql.org/documentation/head/query.html#fetchsize-example) to a value other than 0 makes the JDBC driver use cursors, which disables parallel query.
Comment: Warning: if you do set ResultSet fetch size in DBeaver to 0 be wary of previewing a table using F4!

DBEaver Vs PG Admin


Difference between signed / unsigned char

Question: So I know that the difference between a signed int and unsigned int is that a bit is used to signify if the number if positive or negative, but how does this apply to a char? How can a character be positive or negative?
Comment: *"So I know that the difference between a signed and unsigned int is that a bit is used to signify if the number if positive or negative"* - Note that this is just one of the ways to to it and not the most usual and practical one.
Comment: [A previous answer](http://stackoverflow.com/questions/75191/unsigned-char) on this topic will help.
Answer: There's no dedicated "character type" in C language. char is an integer type, same (in that regard) as int, short and other integer types. char just happens to be the smallest integer type. So, just like any other integer type, it can be signed or unsigned.
It is true that (as the name suggests) char is mostly intended to be used to represent characters. But characters in C are represented by their integer "codes", so there's nothing unusual in the fact that an integer type char is used to serve that purpose.
The only general difference between char and other integer types is that plain char is not synonymous with signed char, while with other integer types the signed modifier is optional/implied.
Comment: C89 18.104.22.168 "There are three character types, designated as char , signed char, and unsigned char."

C11 6.2.5p15 "The three types `char`, `signed char`, and `unsigned char` are collectively called the *character types*." 6.2.5fn45 "`char` is a separate type from the other two and is not compatible with either"
Comment: @Chiggins: Is it binary? If so, then yes. Your `01011011` is a binary representation of 91. So, it represents whatever character has code 91 on your platform (`[` on PC, for example).
Comment: For a simple proof of the nature of chars being ints try applying `swtich...case`, which can be applied only to integral numeric values.
Comment: Alright, hopefully you'll be able to stay with me here, I'm not that great with bits / C and stuff. So with a signed char, something like "01011011" could represent one character?
Answer: I slightly disagree with the above. The unsigned char simply means: Use the most significant bit instead of treating it as a bit flag for +/- sign when performing arithmetic operations.
It makes significance if you use char as a number for instance:
typedef char BYTE1;
typedef unsigned char BYTE2;

BYTE1 a;
BYTE2 b;

For variable a, only 7 bits are available and its range is (-127 to 127)  = (+/-)2^7 -1.
For variable b all 8 bits are available and the range is 0 to 255 (2^8 -1).
If you use char as character, "unsigned" is completely ignored by the compiler just as comments are removed from your program.
Comment: **This is incorrect**. In C, signed integer types use two's complement, with range `-(2^n-1)` to `(2^n-1)-1`, where `n` is the number of bits and `0` is counted once, not twice. By default, a `char` is unsigned, not signed. Please correct this; it is a simple **but incorrect** explanation.
Comment: I think you did a mistake (correct me if I'm wrong):
"a" is signed char so the range is -128 to 127   and
"b" is unsigned char so the range is 0 to 255.
[similar question](http://stackoverflow.com/questions/75191/what-is-an-unsigned-char)
Comment: You need to change this answer to reflect that signed integers use twos complement and not a sign bit like you say, because as it stands this answer is incorrect.
Comment: wizzwizz4: AFAIK **if char is unsigned or signed by default is defined by the implementation** not by the standard (e.g. see http://stackoverflow.com/a/2054941/138526)
Comment: @wizzwizz4 The C standard does not define the encoding format for signed integers. It is up to the compiler designer to choose between 2s complement, 1s complement and sign & magnitude.
Comment: @wizzwizz4 As far as my understanding of the C11 standard goes, the actual smallest value *is* -127. So you can end up with no -128. See Section 184.108.40.206.1.
Comment: as written above, this is not what the standard says. Being unsigned could in principal only mean "ignore the sign bit". Nothing guarantees that an unsigned type will be able to hold larger positive value than its signed counterpart.
Comment: The signed bit also **does not change the way arithmetic works**, adding the two unsigned numbers 4294967295 and 4294967295 will still give you a signed -2.  Type is **only** for humans and has no meaning at a binary level.
Comment: @Matthew Mitchell read the question again. He didn't want a thesis on that. simple questions deserve simple answers.. I don't over complicating things to impress others!
Comment: @user1251840 : http://stackoverflow.com/questions/3724242/what-is-the-difference-between-int-and-uint-long-and-ulong
Comment: Quick correction to the above: comparisons are changed depending on whether it is signed or unsigned.
Comment: @Garogolun You are right, I think. I've deleted one of my comments, but I'm not sure enough to delete the other.
Comment: I'm here a bit late, but if I remember my undergrad course 2s complement makes the math a bit easier, but doesn't affect the storage capacity of the int. Saying the answer is incorrect only because of that seems a bit pedantic, as the veracity of the answer does not depend on the way you encode your int.
Answer: There are three char types: (plain) char, signed char and unsigned char.  Any char is usually an 8-bit integer* and in that sense, a signed and unsigned char have a useful meaning (generally equivalent to uint8_t and int8_t).  When used as a character in the sense of text, use a char (also referred to as a plain char).  This is typically a signed char but can be implemented either way by the compiler.
* Technically, a char can be any size as long as sizeof(char) is 1, but it is usually an 8-bit integer.
Comment: @Martin It applies to C in even greater degree than to C++
Comment: "There are three char types" - That only applies to C++.
Answer: Representation is the same, the meaning is different. e.g, 0xFF, it both represented as "FF". When it is treated as "char", it is negative number -1; but it is 255 as unsigned. When it comes to bit shifting, it is a big difference since the sign bit is not shifted. e.g, if you shift 255 right 1 bit, it will get 127; shifting "-1" right will be no effect.
Comment: Note that the behavior of a right bitshift on a signed type is actually implementation defined. "Most" compilers will shift `-1` to `/-1` but you could actually also get `10111111`
Answer: A signed char is a signed value which is typically smaller than, and is guaranteed not to be bigger than, a short.  An unsigned char is an unsigned value which is typically smaller than, and is guaranteed not to be bigger than, a short.  A type char without a signed or unsigned qualifier may behave as either a signed or unsigned char; this is usually implementation-defined, but there are a couple of cases where it is not:
If, in the target platform's character set, any of the characters required by standard C would map to a code higher than the maximum `signed char`, then `char` must be unsigned.
If `char` and `short` are the same size, then `char` must be signed.
Part of the reason there are two dialects of "C" (those where char is signed, and those where it is unsigned) is that there are some implementations where char must be unsigned, and others where it must be signed.
Answer: The same way -- e.g. if you have an 8-bit char, 7 bits can be used for magnitude and 1 for sign. So an unsigned char might range from 0 to 255, whilst a signed char might range from -128 to 127 (for example).
Answer: This because a char is stored at all effects as a 8-bit number. Speaking about a negative or positive char doesn't make sense if you consider it an ASCII code (which can be just signed*)  but makes sense if you use that char to store a number, which could be in range 0-255 or in -128..127 according to the 2-complement representation.
*: it can be also unsigned, it actually depends on the implementation I think, in that case you will have access to extended ASCII charset provided by the encoding used
Answer: The same way how an int can be positive or negative. There is no difference. Actually on many platforms unqualified char is signed.


Can PHP sessions be manually edited?

Question: Can PHP sessions be edited like cookies? Or they're stored on the webhost?
Answer: The session key is stored in the client's browser, while the data is stored on the server.
When the user makes a request on the server, their session key is sent across the network and the values associated with their key are retrieved from the specific session file on the server and are made accessible via $_SESSION.
It it possible to hijack another user's session if the key is intercepted, which is why you should have specific values in the session which associate to the user's computer/network connection (IP address, for example).
Comment: I don't want the user to edit the data. He can't edit the data,right?
Answer: Session data cannot be edited by the user, as they are stored on the server. The user can, however, start a new session and ditch whatever session data he previously had. Also, you should be aware of portential security issues, such as session fixation.
Answer: Usually they're stored in the /tmp directory of a webserver if the host isn't careful. This can be changed with session_save_path(), it's something I do with all of my PHP applications that use sessions.
Answer: This works like below:

Browser requests page, submitting your SID or Session ID with help of a cookie or with the URL.
Server finds cookie files inside the session_save_path() and unserializes the array
You access that info with PHP

Alas, the only thing the client knows is the session's ID, but that can be hijacked, for example by using cookie stealers, or other Cross Site Scripting methods. If I, for example, got your SO session, SO wouldn't know better than I was you. Unless they also check my IP or something like that.

Can PHP sessions be manually edited?


Will a coil of wire acting as an antenna improve reception/transmittance?

Question: I thought that a coil of wire might be good as an antenna. If this is valid would using said antenna improve reception and transmittance if used? Would an antenna of this kind be stronger with more turns in its winding?
Comment: Can we know what is your frequency band of interest? This is 1st parameter of importance. 2nd is the dimensions of your coil. Please include in your description. Without this it just hand-waving.
Comment: I'd prefer you post the equations you'd be using rather than me give you parameters.
Answer:
I thought that a coil of wire might be good as an antenna.

There are a lot of antennas that could be described as "a coil of wire", and some of them are pretty good, but there's a lot more to antenna design than just randomly coiling wires.

If this is valid would using said antenna improve reception and transmittance if used?

As opposed to no antenna at all -- maybe.  If the size of the coil is closer to the wavelength of your signal than the antenna terminals on your radio, then probably.  As opposed to an optimal antenna -- no, pretty much by the definition of "optimal".

Would an antenna of this kind be stronger with more turns in its winding?

Only if it didn't have enough turns to begin with.  If it already had enough, or too many, then no.
Answer: Short answer, probably not, no. Radio waves (RF) is a highly complex field of study, separate from traditional electronics; it would take a book to explain even the basics of RF.
In essence, the antenna must be tuned to the frequency of interest. "Tuning" is both a mechanical and electrical property. "Tuning" is only good for a narrow band of frequencies centered around the target frequency (unless multiple antennas are used, but that imposes other issues.) The biggest effect on tuning is the length of the antenna - shorter antennas pickup higher frequencies. At higher frequencies, all sorts of physical and electrical properties change, which greatly compound their design.
So if interested in a specific frequency, it is far easier to just buy an antenna ready-made for that frequency.
If you want to research further, here is a RF Basics document from Maxim to get you started.
Answer: There are at several kinds of antennas which could be described as "coils of wire", with very different principles.
small loop antennas are actual coils (often with ferrite rods), though they are woven differently from power inductors or actuator coils, as self-capacitance must be reduced. These are tuned by a variable capacitor which is used to complete the LC-circuit with a given resonant frequency. Unlike most other antennas, they are coupled to the magnetic component of the EM-field, and are only good for reception.
full loop antennas look like coils, but operate as groups of folded dipoles. They are tuned to a particular frequency by the perimeter of the loop which must match one wavelength.
helix antennas also look like coils or springs, although they are nothing more than quarter-whip monopoles folded into a helical shape to reduce the size. They are (roughly) tuned a frequency by their unfolded length, which must be between one quarter and one half of a wavelength.


Is Synonyms to tables cost effective within SQL Server 2016

Question: For one of our new projects we are thinking of using lots of Synonyms to tables which refer to another Database and we are fully aware on what it does and how we are going to use them. But what we don't know is, are there any hidden overheads on overall SQL server performance? If not at all.
Comment: Can you give a little more insight into how you plan to use the synonyms? We have a large implementation of them in our production DW environment, but depending on how you plan to use them I might be able to provide some real world experience as to what we've seen.
Comment: Basically we are developing a front end real time solution for our clients and  this tool will sit on top of this particular database, now this particular  database doesn't have all the tables to support our front end requirements, hence we are thinking of using synonyms to all the missing tables, which exist in another database and we want avoid any duplication of data and want our front end to add / amend records as well.
Comment: Synonyms are objects within SQL Server, so there is some tiny overhead in terms of larger internal system tables that SQL Server will need to maintain, keep in memory, etc. For any reasonable # of synonyms, no big deal. But just in case "lots of synonyms" could mean hundreds of thousands or more, this question might be relevant: https://dba.stackexchange.com/q/135201/11635
Comment: @PallavHathi - Got it. I will tell you this. If you plan to query the synonyms directly you will be fine. However, if you plan to build views using the synonyms you will run into performance issues, especially if you where clauses in your views. We made this mistake, if you want to call it a mistake, but we've run into a performance hit if the source of the synonym is a large data set (million records or higher) and we are making the call via a view. Hard to explain in a small comment.
Comment: Thanks everyone for your input. We have implemented synonyms as per planned and will share my experiences here.
Answer: According to this post -

As a synonym is an abstraction/alternative name for an already
  existing database object, in the case of a table, index behaviour is
  identical to that of the underlying object i.e. when execution plans
  are generated, the same plan is generated irrespective of using the
  table name or corresponsing synonym.

You can verify the execution plans when using both the regular object and the synonym to see if they generate the same plan.
This post has a similar question:

How does the use of synonyms effect performance?
More specifically, are synonyms replaced with fully qualified names in
  execution plans? It would seem to me that any synonym has to be
  resolved to the actual object so any query or procedure that doesn't
  have a cached plan is going to have an extra step in mapping the
  synonym to an actual object. I'm thinking there would be a very small
  performance hit in this. Perhaps a slightly larger hit when the
  synonym references an object on a different database and slightly
  larger still when on a different server.

The answer given was

They are swapped out in the Bind phase of query execution same as a
  view would be expanded. This happens before the Optimization phase
  where the execution plan is generated so while you'll still see a
  reference to the synonym in the query text you will only see
  references to the objects the synonyms point to in the execution
  plan's operators.
Any performance hit, if you want to even call it that, that might be
  associated with using synonym is not at all worth being concerned
  about.

I'm sure Paul White (or another expert will provide a definitive response).
Answer: When you say "another database", do you mean within the same instance, i.e. database2.schema.tablename?  If so, you should be fine; overhead is negligible.  Watch out for cross-database permissions issues.
Or do you mean another instance, i.e. instance2.database2.schema.tablename?  If so, this can be terribly bad, particular for multiple joins of four part named objects/synonyms.  See https://blogs.msdn.microsoft.com/sqlsakthi/2011/05/08/best-performer-distributed-query-four-part-or-openquery-when-executing-linked-server-queries-in-sql-server/   for a little more detail, but it boils down to use OPENQUERY or similar (EXECUTE AT works find too) to ship entire SQL statements over.
Comment: It's within same instance.


How to put the code google remarketing?

Question: How I can put the Google AdWords Remarketing in my code?
Is there an extension for magento ?
Comment: did you ever include this?
Comment: This extension should help -: https://www.scommerce-mage.co.uk/magento-google-dynamic-remarketing-tag.html
Answer: I start at the beginning to make it all clear.
1. Create a New Macro in GTM
Head over to GTM and create a new data layer variable macro. Name it as google tag params and variable name as google_tag_params and save it.
2. Create a Firing Rule
Create a new firing rule with condition [event equals fireRemarketingTag] and save it.
3. Create a Remarketing Tag
Create a new remarketing tag and fill up your conversion id. Choose firing rule and the datalayer we created in above process and save it.
We are done with GTM. Now we should head over to Magento. Just paste the below codes on the appropriate templates.
4. template/catalog/product/View.phtml
Paste the below code on your product view template. You can find the file inside the catalog folder.
<?php $_product = Mage::registry("current_product");?>
<?php if ($_product && $_product->getId()): ?>

5. template/checkout/Cart.phtml
Paste the below code on your cart template. You can find the file inside the checkout folder.
<?php $items = Mage::getSingleton("checkout/session")->getQuote()->getAllItems();?>

6. template/checkout/Success.phtml
Paste the below code on your success template. You can find the file inside checkout folder.
<?php
$order = Mage::getModel("sales/order")->loadByIncrementId($this->getOrderId());
$items = $order->getAllItems();
$total = $order->getGrandTotal();
?>

Publish your GTM and We are done! Now your dynamic remarketing should be working!
I did it the same way in my Magento installation and it works fine
Answer: Depending on what kind of google tracking you are using you have a few different way to use:
1) If only add a custom code and should be in all the Magento page, use the "Miscellaneous Scripts" value going to admin section, System > Configuration > Design > HTML Head - Miscellaneous Scripts. (This will be included before head closing tag in page HTML.)
2) By native Magento already have Google Analytics tracking code and you can find this configuration going to admin section System > Configuration > Google API - Google Analytics.
3) If you are looking something more complex and use the Google adWords I used the extension magento connect link: https://www.magentocommerce.com/magento-connect/luka-google-adwords-conversion-tracking.html.
I hope this will help you.
Answer: You don't really need an extensions just to add the codes into every page.
You can just add the codes in your Magento Admin under System --> Configuration --> Design --> Footer --> Miscellaneous HTML.
Comment: Thank you very much. to track conversions from its site I have to put the code or?
Comment: I believe the code for remarketing and conversions are different but they can be added at the same place listed above.
Comment: That's path to put one code in all pages.

How to put the code google remarketing?


Output capacitance effect on stability of DC/DC Buck Converter?

Question: How does having more or less capacitance at the output of a DC/DC buck converter contribute to the location of the poles and zeros. Is there a way to crudely make this calculation.
Comment: See: http://www.ti.com/lit/an/slva301/slva301.pdf
Comment: The overall output L and C of a buck will have a gain peak at their resonant frequency and a roll-off beyond that point. Part of a well-designed feedback loop is verification of stability at both the specified minimum and maximum output capacitance.
Answer: It depends on many factors. The load (ohmic or others), the state variables, the operation mode (CCM/DCM) and others. After you decide these factors you can formulate the state matrices (A,B,C,D).
Following is a simple Matlab code may help you studying any converter poles position with different capacitor values. The state formulation is taken from this paper. The capacitor varies between \$5 \mu F\$ and \$50 \mu F\$ with step change of \$5 \mu F\$.
<code>L=1e-3;
R=10;
c=5e-6;
d=0.5;
B=[d/L;0];
C=[1 0;0 1];
D=[0;0];
hold on
for i=1:10
    A=[0 -1/L;1/c -1/(R*c)];
    sys=idss(A,B,C,D);
    pzmap(sys);
    c=c+5e-6;
end
</code>
And the result for this particular case,

So for this particular formulation, the increment of capacitor drag the poles of the system to the right hand side of the poles map.
Comment: Where is ESR in your analysis?  What practical  value is it without component limitations? of ESR in e-caps and DCR in chokes and Ron in switches.
Comment: As I mentioned in the answer, this is a general code to analyse pole placement of any converter. If the user is interested in including ESR or any other practical element, he/she may modify (A,B,C,D) accordingly and run the code.
Comment: My point is without ESR included  any analysis is invalid.
Answer: The output capacitance causes a pole.  However, how relevant this is to stability depends a great deal on the control algorithm.  For example, a pulse on demand system doesn't have a stability issue in the first place, although it can go meta-stable, and the output capacitor and its ESR can affect that.
Before you talk about stability, you have to describe the control algorithm you are using.  Different algorithms have different inherent poles and zeros.
Comment: "Pulse on demand" = hysteretic?
Answer: If you look at the output filter of buck converter it is a simple LC low pass network with a resistive load. It has a bode plot like this: -

As you can see there is a peak in the frequency response at about 16 kHz and this is due to the Q of the circuit.
The Q for this type of circuit is \$R\sqrt{\frac{C}{L}}\$.
With the values I've chosen, Q = 100 and produces a 100x peak at resonance. That's +40 dB on the graph. If I were to increase the capacitance by 100 times Q would become 1000. If I decreased Q by 100 times, Q would be 10.
Next is to understand that a change of Q means a movement of pole position. However, to make a calculation of pole-position it is more useful to use the term "damping ratio" (or \$\zeta\$) instead of Q where \$\zeta\$ = 1/2Q.
So as Q rises, \$\zeta\$ falls. Now take a look at these two pictures below (left and right): -

On the left is a 3D view of the pole-zero diagram and this is for a low pass 2nd order filter exactly like the LC filter on a buck converter. In other words, it is relevant to the question.
In the 3D picture you should be able to see is the bode plot view and how it fits into the bigger picture of the pole zero diagram. On the right is the traditional pole-zero digram i.e. it is looking from above down onto the 3D picture on the left.
One pole is shown for convenience (although there are two symmetrical poles) and its position is determined by only two parameters: \$\omega_n\$ and \$\zeta\$.

Real part is \$-\omega_n\zeta\$
Imaginery part is \$\omega_n\sqrt{1-\zeta^2}\$

However those co-ordinates can be divided by \$\omega_n\$ leaving just \$\zeta\$ as the factor that moves the pole position.
So, if \$\zeta\$ is very small (i.e. the Q is very high and the bode plot peak is correspondingly high) the pole position is much closer to the jw axis. This can cause instability and certainly a lot of transient ringing on the output of a buck converter.
To add a little more meat, if you return to the original bode plot and look at the phase response of the filter you will see that at DC there is no phase lag or lead and this remains largely so until you hit the resonance of the filter. At resonance the phase response inverts to 180 degrees pretty rapidly. So, if this filter is within the control loop of the buck regulator, you need to take additional measures to prevent negative feedback turning into positive feedback at resonance and above.

How does having more or less capacitance at the output of a DC/DC buck
  converter contribute to the location of the poles and zeros. Is there
  a way to crudely make this calculation.

Estimate the load resistance from output voltage and current
Plug values into Q formula
Convert Q to zeta
\$\zeta\$ tells you how close the pole is to the jw axis

If the output capacitor has significant ESR I would want to make a simulation because of the effect it has on the phase response, For instance, here's the same values as used in the original bode plot but with  0.05 ohms in series with C1: -

Now the phase angle doesn't quite reach -180 degrees and therefore some margin of stability has been achieved. However, this will be at the expense of a very slight increase in switching ripple. But remember, in any (if not all) buck converters some form of lead compensation is done in the error amplifier to "pull" the overall phase response significantly away from -180 degrees and back towards higher stability; it doesn't matter that this is a switching converter - you could model it as a linear amplifier with the output filter LC within the feedback loop - without that lead compensation the buck converter will be unstable because it sails just too close to having open loop gain at phase angles close to -180 degrees.
The position of the poles caused by the LC filter are now affected by lead compensation and what might of been a crude way to predict their position becomes less accurate and some form of simulation is what I would recommend.
Comment: that's a nice and heavily invested question. Thank you. Unfortunately we all are too busy to just experiment with some buck EVK and see what happens...
Comment: Analysis looks excellent but neglects ESR which affects results greatly.   for 10uF  e-cap , ESR*C=T ranges from 7us to 500us and Zo=1 ohm so Q will be substantially lower than 100 and as shown will be <2.
Comment: The last part covers ESR @TONY. BTW I worked on Mc phereson street for a while. I'm positive you'll know where.
Comment: give me a clue..
Comment: @tony dunno if still there but they made metal detectors, called goring kerr and more latterly thermo.
Comment: Andy so anything like "you can add 100uF and not be afraid" or "don't play with capacitance at all"?
Comment: @GregoryKornblum I can't be drawn into making sweeping statements like that without a specific design.
Comment: Well... Your example seems specific enough. Maybe you could specify a switching IC or just take some general assumption.
Comment: The question isn't really about that as far as I can tell. I haven't gone into any detail about the switching mechanism or IC and I don't see it as necessary. Basically, be aware of what the filter does and notice the compensation techniques involved is what my answer is about.
Comment: I mean, guy who asked the question (and many others) probably doesn't know the control theory and will not learn it from your post. So talking about poles and zeroes is definitely not effective...
Comment: Poles and zeroes are mentioned in the question so I'm baffled as to why you think mentioning it  in an answer would be ineffective.
Answer: The output capacitance has a non-linear effect on the regulation.  Remember that the buck converter can provide current to drive the output capacitor voltage in the positive direction only.  If the voltage is instantaneously too high from a rapid change in load, inductive kick, or an increase in line voltage, the capacitor can only be discharged through the load current and not by the converter.  So you have different ramp times for charging and discharging the cap, and if your load is varying, the discharge time will vary with it.  You can choose the output cap large enough for reduction in noise and ripple, but if you make the cap too large, the power supply will recover only slowly from overshoot.    In general if you keep the time constant of the output capacitance and minimum load short enough (don't run unloaded), the output capacitance will not dominate.  Similarly, your inductor max current will only charge the capacitor so fast.  So the "crude" answer is to use the smallest output capacitor consistent with your required ripple current and then make sure your loop time constant is timed to make the cap response irrelevant as @Olin Lathrop says above.  It is not a good idea to make the power supply response time constant dependent on the output capacitor, because variation in the load changes its contribution.
Answer: The question is erroneous, because it assumes falsely that the value of Cout is the only contributing factor to stability when it depends on DCM,CCM mode , loop compensation, Cap ESR*C=T values and more directly, chip design if it is internally compensated,  which is better for simple design in the feedback loop.
All e-caps have at least one breakpoint defined by the series ESR or Rs and associated capacitance, C such that T=ESR*C. The design and quality of such caps has a wide range of T values where ultra-low ESR is T < 10us and general purpose e-caps are T > 100us and ceramic/plastic caps have T<< 1us.  Remember that 1/T=ω.
Keep in mind a bigger cap also means bigger ESR in the same family and thus more ripple which also gives more feedback without as much phase shift so it is also more stable but more ripple on the output.  Then adding smaller caps in parallel reduces the high frequency ripple  but at the expense of reducing phase margin which shows up as step load overshoot.
Therefore , although C value has a significant effect on the ripple and stability of the loop, more important is the understanding that it is the ESR*C values of all capacitors for stability and also the choice of internally compensation IC's or not and choice of external loop compensation.
In Op Amp design , unity gain loop stability is possible with internal compensation because we only consider small signal response here, meaning no current limited slew rate. But in a SMPS, each pulse is ramping up towards full current on a pulse to pulse basis with PWM cutoff so the ESR of your switch, inductor and load capacitor as well as load resistance ratios are all interactive in the feedback loop stability of this control system for poles and zeros, unlike simple Op Amps.  So it is much more complex.
See excellent example below which has low ripple 25mΩ//5mΩ//100uΩ  due ultra low ESR from 2 e-caps and 50x ceramic caps all in parallel , yet 60 deg phase margin!
Answer: Reading in IEEE Transactions on Circuits and Systems (the Yellow rag), some years ago the hot topic was Switching Regulators and the Stability thereof.
Problem with switchers is the LARGE # of poles and zeros, as parasitics and silicon sneak paths get modeled.
I recall the # being 8 or 10 or 13 poles+zeros.
And this other perilous problem:
Consider the feedback loop inside some silicon chip, with 1mm * 1mm loop area, being 1mm away from some aggressor magnetic field that may be inside the chip or just outside. What voltage gets induced in this, from 1 amp/1nanosecond current transient?
Using a combination of Biot-Savart and Faraday, written for long straight wire coupling into a loop coplanar with the wire, we have the useful formula
Vinduce = 2e-7 * Area/Distance * dI/dT
In a 1mm cube model of Area/Distance, we get 2e-7H/m * 0.001m * 10^+9 amp/sec, or
Vinduce = 2e-10 * 1e-9 == 2e-1 == 0.2 volts. Can you have a reliable SwitchReg with 0.2 volt spikes injected into the feedback circuits? I think not.
Comment: So what's the conclusion?
Comment: Where do you have 1 amp/nanosecond transients?
Comment: The OP asked a "stability" question. I've explained (1) the model needs to include the higher order parasitics; (2) the model needs to include magnetically-induced feedback, not just the intended voltage-divider feedback.
Comment: OP asks for the effect of output cap when used more or less than calculated.


Global Section Functor Existence for Pre(Co)Sheaves?

Question: I currently have a co-presheaf  F : Top -> Vect. I don't know how to cosheafify it.
It is well-known that the Global section functor for sheaves is a covariant left exact functor (right exact for cosheaves). Is this also defined for a (co) presheaf?
Answer: A (co)presheaf on a space $X$ is the same thing as a (co)sheaf on the space $Y$ whose underlying set is the set of all open subsets of $X$, with a basis for the open subsets of $Y$ being the sets of the form $d(U)=\{V\in Y:V\subseteq U\}$ for each open subset $U\subseteq X$.  In $Y$, no basic open set $d(U)$ can be written as a union of strictly smaller basic open sets (since none of them can contain the point $U$), and it follows that any functor on the poset of basic open sets extends uniquely to a (co)sheaf.  But such a functor is just a (co)presheaf on $X$, so you get an equivalence between the category of (co)presheaves on $X$ and the category of (co)sheaves on $Y$.
So if you know that the global sections functor is left (right) exact on (co)sheaves on any space, you automatically get the same result for (co)presheaves on any space.
(Incidentally, I have not thought about it myself much, but according to the answers to this question on MO, describing the cosheafification of copresheaves (or even proving that it exists) seems to be quite nontrivial.)
Comment: Thanks! Yes the cosheafification business seems very interesting but thankfully not necessary for me...


How can I link from one location to another?

Question: I have a directory of files and accidentally got two versions of the same document under different names, how can I create a symbolic link from one to the other, so that there is only one file, yet keep the duplicate link working since some might be using it?  Ideally the link would be invisible, since it is only for backwards compatibility and not useful for browsing the files in the directory.
Answer: SharePoint does not support symbolic links. An alternative solution would be to create a link from the incorrect location/folder of the files to the correct location/folder of the files.
Comment: Is there a way to hide the link?
Comment: Do I understand correctly that you want to automatically redirect from the old/incorrect location to the new/correct location?
Comment: Yes, but not advertise the old location.
Comment: That's odd.  I thought symlinks operated at Window's file system level.  From SharePoint's perspective I would hope it wouldn't care whether the file is an original or a link.  Not supporting symlinks makes tools like [Capistrano](http://capistranorb.com/) impossible.
Answer: This is how I created a link:

In SharePoint select the folder you want the link to point, go to "Show actions" popup menu (i.e. the three dots icon shown when hovering over the folder) and select "Copy link" and copy the link.

Go to the folder where you want or need the link. From the "New" menu select "Link". In the popup window paste the copied link in the entry box below "Create link to" and press "Enter"

A file type "Link" will appear in the folder where you want or need the link.


First two talents and characteristics question

Question: I have a question on creating a new character. You get two random talents with the starting career....on one of them I rolled Lightning Reflexes, which is +5% to your Agility. Its a Diletante and he only has +5% as a possible advance in agility, the Lightning Reflexes count to that right, even though its random starting talent?
Answer: Lightning Reflexes says:

You gain a permanent +5% bonus to your Agility
  Characteristic. Modify your starting profile to reflect this
  bonus.

So when you get Lightning Reflexes, you add +5% to your starting Agility, not your current Agility. Your current Agility is always calculated by adding any advances you've taken to your starting Agility.
Comment: Thats what I needed to know. Thank You very much=)
Comment: @Elgyn Glad to help!
Comment: This also applies more generally. Stat gains from Talents are *not* advances and do not affect your advance scheme.


NewSequentialId on UniqueIdentifier Clustered Index

Question: I am working on database standards for a new database my company is starting.  One of the things we are trying to define is Primary Key and Clustered Index rules in relation to UniqueIdentifiers.
(NOTE: I do not want a discussion on the pros and cons of using a UniqueIdentifier as a primary key or clustered index.  There is a ton of info on the web about that.  This is not that discussion.)
So here is the scenario that has me worried:
Say I have a table with a UniqueIdentifier as the clustered index and primary key.  Lets call it ColA.  I set the default value for ColA to be NewSequentialId().
Using that NewSequentialId() I insert three sequential rows:
{72586AA4-D2C3-440D-A9FE-CC7988DDF065}
{72586AA4-D2C3-440D-A9FE-CC7988DDF066}
{72586AA4-D2C3-440D-A9FE-CC7988DDF067}
Then I reboot my server.  The docs for NewSequentialId say that "After restarting Windows, the GUID can start again from a lower range, but is still globally unique."
So the next starting point can be lower than the previous range.
So after the restart, I insert 3 more values:
{35729A0C-F016-4645-ABA9-B098D2003E64}
{35729A0C-F016-4645-ABA9-B098D2003E65}
{35729A0C-F016-4645-ABA9-B098D2003E66}
(I am not sure exactly how the guid is represented in the database, but lets assume since this one starts with 3 and the previous ones started with 7 that the 3 ones are "smaller" than the 7 ones.)
When you do an insert that is in the middle of a clustered index, a remapping of the index has to happen.  (At least so my DBA has told me.)  And every time I reboot I run the risk of having my new UniqueIdentifier range be right in the middle of other previous ranges.
So my question is: Since the next set of UniqueIdentifiers will be smaller than the last set, will every insert cause my clustered index to shuffle?
And if not, why?  Does SQL Server know that I am using NewSequentialId?  Does it some how compensate for that?
If not, then how does it know what I will insert next?  Maybe the next million inserts will start with 3.  Or maybe they will start with 7.  How does it know?
Or does it not know and just keeps everything in order.  If that is the case then one reboot could massively affect performance.  (Which makes me think I need my own custom NewSequentialId that is not affected by reboots.)  Is that correct?  Or is there some magic I am not aware of?
EDIT: GUID as a clustered index is strongly discouraged in my standard.  As I said above, there are many reasons that this is a bad idea.  I am trying to find out if this is another reason why.
Comment: "If that is the case then one reboot could massively affect performance." - that is why you want to use an int IDENTITY(), even though you don't want to hear it.
Answer: Normally you will create your indexes with an appropriate FILL FACTOR to leave empty space in all your pages for just such a scenario.  That being said, the clustered index does get reordered once the empty space is filled.
I know you don't want to discuss using GUID as a clustered key, but this is one of the reasons that it's not a recommended practice.
What will happen is that you will have an increasing volume of page splits, which will lead to a very high level of fragmentation as you keep inserting rows, and you will need to rebuild your index at a higher frequency to keep performance in line.
For a full treatment on the topic, there's no better source than
Kim
Tripp's
Blog
As a side note, when you are considering creating your own NewSequentialID creation function, you probably have a design issue and should reconsider your plan.
Comment: I have read several of her posts already.  GUID as a clustered index is strongly discouraged in my standard.  I am trying to build a case for why.  (Hence this question.)
Comment: Once the fill factor is reached, will each and every insert cause a reordering?
Comment: It depends.  Fill factor is by page, so once the page is full then yes.  All subsequent inserts will cause a reorder if the page they need to insert into is full.


Can the federal government withhold money from states that refuse to institute vaccine mandates?

Question: Could Congress pass a law that revoked some of a states funding until they mandate vaccines, or can the federal government not withhold funding to get states to pass laws?
Comment: Maybe we should first ascertain if mandating vaccines pass a constitutional test. Generally there has been a widespread consensus that people do have the right to refuse medical treatments.
Comment: @NeilMeyer It's an open question.  Jacobson is the "controlling" precedent, but it was decided during the eugenics era before Nazis made eugenics unfashionable so a modern SCOTUS could overturn or restrict it.
Answer: Yes, they absolutely can do this as long as they write the rules to allow this and they have done this for other things. There is nothing that prevents congress from deciding how to allocate those funds and what is required to get them though it could always be challenged in court.
A good example of this would be the drinking age of 21 and how federal provided highway funds will get withheld if a state doesn't prevent under 21 from drinking.
https://alcoholpolicy.niaaa.nih.gov/the-1984-national-minimum-drinking-age-act

The 1984 National Minimum Drinking Age Act, [23 U.S.C. § 158], requires that States prohibit persons under 21 years of age from purchasing or publicly possessing alcoholic beverages as a condition of receiving State highway funds.
Comment: I think they did this for the 55 MPH speed limit and "right turn on red", too.
Answer:
Can the federal government withhold money from states that refuse to institute vaccine mandates?

Yes, provided the money withheld is related to paying for vaccinations. (See, Relationship Between the Conditions and the Purpose of the Federal Funds, below.) But, understand that it would not likely happen, because the federal government wants people to be vaccinated. Withholding funds used for vaccinations would make it less likely that people would become vaccinated.
The Federal Government's Authority to Impose Conditions on Grant Funds, March 23, 2017

The Spending Clause
While Congress would generally not be permitted to compel state legislators or executive officials to enforce or administer a federal regulatory program, it could provide federal grants to encourage states to participate in a federal program. Providing federal funds to nonfederal entities has been seen to constitute an exercise of one of Congress's enumerated powers, namely, its power under the Spending Clause of the Constitution (Article I, Section 8, Clause 1). The Spending Clause expressly empowers Congress "to lay and collect Taxes, ... to ... provide for the ... general Welfare of the United States." When Congress uses its Spending Clause authority, it may generally prescribe the terms and conditions under which the federal funds are accepted and used by recipients. These conditions may generally specify that the funds be used for particular purposes or, alternatively, prohibit their use for certain purposes.
Recipients of federal financial assistance in the form of grants may also be required, as a condition of accepting the grant, to perform or refrain from certain actions. Through the  attachment of such conditions to federal funding, Congress may attain federal policy objectives in areas that it lacks the power to regulate directly (that is, the objectives do not fall within "the enumerated legislative fields committed to the Congress" by the Constitution). As the Supreme Court has explained, legislation enacted pursuant to the Spending Clause is one significant way that Congress may influence state behavior without "commandeering" state officials in violation of the Tenth Amendment:

Congress has frequently employed the Spending Power to further broad policy objectives by conditioning receipt of federal moneys upon compliance by the recipient with federal statutory and administrative directives. This Court has repeatedly upheld against constitutional challenge the use of this technique to induce governments and private parties to cooperate voluntarily with federal policy.

Limitations on the Spending Power

Although Congress's power under the Spending Clause is expansive, the Supreme Court articulated certain limitations on the use of federal grant conditions in its 1987 decision in South Dakota v. Dole — which arguably remains the leading decision regarding the use of the federal government's conditional spending power — and in subsequent cases. In particular, these limitations require that any conditions attached to the receipt of federal funds must:

be unambiguously established so that recipients can knowingly accept or reject
them;

be germane to the federal interest in the particular national projects or programs to which the money is directed;

not violate a separate constitutional provision, such as the First Amendment or the Due Process or Takings Clauses of the Fifth Amendment; and

not cross the line from enticement to coercion, such that states have no real choice but to accept the funding and enact or administer a federal program.

...

With regard to item 2, "germaneness",

Relationship Between the Conditions and the Purpose of the Federal Funds
The Supreme Court has also suggested that grant conditions may be improper if they are unrelated "to the particular national projects or programs" to which the federal funds are being directed. The Court has not provided further elaboration on the nature of this "relationship" requirement, other than by noting that grant conditions must "bear some relationship" to the underlying purposes of the funds "otherwise ... the spending power could render academic the Constitution's other grants and limits of federal authority." The Court does not appear to have invalidated a federal spending condition on the basis that it fails this "relatedness" standard, nor has any lower court seemingly done so.
In its 1982 decision in South Dakota v. Dole, the Supreme Court engaged in what is arguably its most notable discussion of the "relatedness" standard to date. The Dole case concerned the National Minimum Drinking Age Amendment of 1984, which authorized the Secretary of Transportation to withhold 5% of federal highway funds from states which permitted persons below 21 years of age to purchase alcohol. The State of South Dakota, which allowed persons as young as 19 years old to purchase alcohol, did not argue that this federal highway funding condition violated the "germaneness" principle, instead conceding that it "ha[d] never contended that the congressional action was ... unrelated to a national concern in the absence of the Twenty-first Amendment." Nevertheless, a majority of the Court opined that although the grant "condition was not a restriction on how the highway funds — set aside for specific highway improvement and maintenance efforts — were to be used," conditioning a portion of a state's federal highway funds on its adoption of a minimum drinking age of 21 years was permissible because it was "directly related to one of the main purposes for which highway funds are expended — safe interstate travel." The dissenting opinion authored by Justice O'Connor, in contrast, would have found that this drinking age condition not to be sufficiently related to the expenditure of federal funds for highway construction. In particular, Justice O'Connor argued that Congress:

is not entitled to insist as a condition of the use of highway funds that the State impose or change regulations in other areas of the State's social and economic life because of an attenuated or tangential relationship to highway use or safety. Indeed, if the rule were otherwise, the Congress could effectively regulate almost any area of a State's social, political, or economic life on the theory that use of the interstate transportation system is somehow enhanced.
Comment: Given Joe's example, I'm not convinced this is the only way the Federal gov't could "punish" such states. Note that the Q does allow for new legislation. It's probably not unconstitutional to tie random other "pork" to vaccine mandates (in new laws). Whether such laws could pass  (filibuster) is another matter...
Comment: The part you've quoted from the Supreme Court does't say they have to be related. Nor does that bit seem to be in the Constitution. "Settled law" is more like what the CRS says the current practice is.
Comment: It should be viewed the other way: If you mandate vaccinations, we'll provide federal dollars to subsidize the program, rather than withholding as punishment for not mandating.
Comment: @Fizz - "Recipients of federal financial assistance ... may also be required, as a condition ..., to perform ... certain actions." There must be a link between the assistance granted and the condition; thus Congress could not withhold unrelated funds as a condition. This is settle law. Drinking age and road construction/repair are related.
Comment: @Barmar - *It should be viewed the other way.* Yes, it should, but its not like that. Going from memory, the CARES Act uses federal funds to pay for all vaccines and their administration. If one is vaccinated at a pharmacy, for example, the pharmacy submits an invoice to the feds. In a few cases, mostly Medicaid and foster care, the state has responsibility for administering vaccinations. Withholding funds for vaccinating those individuals is in no one's interest; but that is where the "leverage" would be.
Comment: @Fizz - *See*, [Relationship Between the Conditions and the Purpose of the Federal Funds](https://www.everycrsreport.com/files/20170323_R44797_36eb380c05663646f82405ecc6d512de9bf7968a.pdf#page=11). "The Supreme Court has also suggested that grant conditions may be improper if they are unrelated 'to the particular national projects or programs' to which the federal funds are being directed. ..."
Answer: I think that FedGov can lawfully use these non-forceful tax incentives to restrict social activities to reasonably prevent disease spread.  My understanding is that Congress can use this digression IF the issue falls under their power to tax (enumerated powers).  The "general welfare" clause and the "interstate commerce" clause have been massively abused in other cases, but this case seems clear.
Measures that reduce the prevalence and spread of disease seem perfectly within the "general welfare" clause.  It aids everyone (broadly, generally), and is, in this case, non-rivalous.  Of course this grant-witholding applies to COVID containment funding only.
Comment: Welcome to Politics Stack Exchange. Please note that this community is not for exchanging personal opinions. It is for explaining politics and political processes from a neutral point of view. Answers to a question like this should not be concerned with what would be ethical or the right thing to do, but stick to the question actually asked. I therefore removed those parts of this answer which do not address this. [Editing content posted by other users is a regular part of the Stack Exchange system](https://politics.stackexchange.com/help/editing).


What are the benefits of resource(.resx) files?

Question: What compelling reasons exist for using them?
Comment: I've never used resx before. That is the reason behind the question.
Comment: If you've never used a resx file before, but have your own string tables and the like (or worse, strings scattered throughout the code, all locally defined) and haven't seen a reason to change that approach, then this is a legit question.
Answer:
Resource files give you an easy way to localize/internationalize your .net applications by automatically determining which language resx file to use based on the user's locale.  To add more languages, simply add another translated resource file.
Resource files give you a central location to store your strings, files and scripts and refer to them in a strongly-typed manner (so the compile will break if you reference them improperly).
Resource files can be compiled into satellite assemblies, making it easy to change up the resources in a production application without having to recompile the whole thing.
Answer: As a supplement to the other answers, string resources are for human-readable text, not constants that will be used programmatically. They're great for error messages, button labels and the like.
Very often, rather than the final string, we store a format string so that variables can be substituted in at the last moment. The nice thing about this method is that, unlike concatenation, it's not broken when a language has different word order requirements.
Comment: +1 for that indeed! Though There Be Dragons still; e.g. where English has "one" and "many", Slovenian e.g. has "one", "few" and "many".
Comment: It's an annoying redirection to a separate "res" file ever time someone references a formatted string for logging.
Answer: Resource files enable you to change the text/graphics your program will display without editting the code of the program itself.  For many reasons, it is often considered ideal to avoid needing to edit your program's source code in order to make changes that are not part of your application's logic.
Answer: With resx you can have one per language (that is spoken language not programming language) enabling your program / system to be multilingual.
Comment: Yes - the world is *NOT* just speaking English!
Comment: any tutorial on how to do that with a simple example?
Comment: @KansaiRobot hope you find this blog helpful - [Satellite Assemblies in .NET](https://www.codeproject.com/Articles/801343/All-you-wanted-to-know-about-Satellite-Assemblies)
Answer: In addition to the answers above, resource files can also provide you an place to store test files for performing Read/Write tests. That way, regardless of how other people's environment is set up, you can have a place to store logs or other files.
Keep in mind that what files you do place in resources must be serializable. Check below for more info:
https://msdn.microsoft.com/en-us/library/f45fce5x(v=vs.80).aspx


Wall switch no longer used, how to cover it

Question: I have replaced a ceiling fan in my home that had a separate hot wire for a light. The new fan has a remote control for the light & fan motor.  The old fan was controlled from a 5-gang wall switch.  Switch 2 was for the light, position 3 had a fan speed control.  The other switches are still in use for other lights.  I want to remove 2 & 3, to avoid confusion on how to operate the new fan. Does anyone know of either a safe insert to cover the openings in the switch plate when I remove the switches, or a source for a new wall plate? Yes, I have googled to no avail.
Answer: You need a "switch dummy". Also commonly called a "switch blank", "blank insert" and "blank filler".
The big box stores may not carry this item, if not, electrical supply house should have available.
Comment: Also commonly called a "[switch blank](https://www.google.com/search?q=switch+blank)", "blank insert" and  "blank fillter", and they are commonly carried by the big box stores, at least in my area. They are available in both traditional toggle switch size as well as the larger Decora style. I've also seen [duplex outlet fillers](http://www.kyleswitchplates.com/duplex-outlet-blank-filler-insert-for-switch-plates-leviton-41087-2bnk/),  but those seem to be harder to find.
Comment: @Johnny thanks for the alternate name suggestions, edited.


I found what, I believe, is a backdoor in my home router, what should I do?

Question: My country doesn't have any laws regarding this subject (Brazil). And I don't want to disclose it to the police, it's more likely they will just keep it to themselves. What should I do?
Comment: OP's problem is there is a backdoor in the firmware running on their router, dd-wrt is known to not have a backdoor. that is completely unrelated to 'other bugs'. OP doesn't want a backdoor and dd-wrt doesn't have one - therefore solution.
Comment: solution: custom firmware (e.g. dd-wrt)
Comment: Ummmm...
A planted back door, or an exploit?
Comment: Most questions involving "should" are too local to be useful. What you should do in Brazil is different from what you should do in China.  There is no way to evaluate the answer.
Comment: @EricStalnik - How is that a solution?  dd-wrt can have bugs within it.  Its unlikely the user found a backdoor based on language used.
Answer: In your circumstances the simple guidance I would give is:
Do not use the router, get rid of it and buy a new one. You can check it to see if it has the same problem.
In reality, confirming backdoors can be problematic, and even if you reflashed firmware, there could be others, assuming you have been targeted.
Edit: as @Polynomial comments - in terms of disclosure, the vendor might be a better bet than the police, and if they aren't interested, Full Disclosure is an option.
Comment: Also can't hurt to report it to the vendor (might've been a debug backdoor that wasn't meant to make it to production), or drop it on [Full Disclosure](http://seclists.org/fulldisclosure/) if they have no intention of fixing it.
Comment: Polynomial's suggestion is the ethical one. If there's a backdoor in one router, then there's almost certainly a back door in every router of that model, and possibly many other related models. That being so, the company should be notified so that it can fix it, and notify users of the update. If they refuse, users should be notified directly (public posting), so they can make their own decision. All the other solutions are kind of pointlessly individualistic, and help no-one in the long run (who's to say the next router you buy won't have a similar problem?).
Answer: Given that some of the backdoor exploits seen on network equipment are actually built into the hardware the only solution would be outright replacement with equipment with no known exploits.
Before taking that step you should make sure you know what you are talking about, as Occam's Razor would suggest a simpler explanation for whatever you are seeing, namely that your password has been discovered, your computer has been hacked, or someone has broken your wireless password and is on your network. I'm saying this despite having no description of why you think your system has a backdoor, this is because having someone exploiting a back door into your network through a network device is the least likely possibility, therefore you should investigate other possibilities first.
If it does actually turn out to be a back door, all you can do (besides replace it) is notify the manufacturer so they can work on a fix (presuming that they aren't the ones who put the back door in in the first place), and notify law enforcement. The police are never the ones to go to no matter where they are as they don't have the skills to deal with it, however many countries have a cybercrime squad so that may be the best way to go. If you get no satisfaction through those paths I'd post the details on the web (as anonymously as you can) so that others with the same equipment will be warned.


How is it possible for a collision to be responsible for Uranus's axial tilt?

Question: I realize that the collision explanation is in any case highly (purely?) speculative, but I'm curious how it would work.  If Uranus is a ball of gas, why wouldn't any colliding object just pass through (or perhaps be destroyed/significantly damaged by the heat of friction)?  What would there be for the colliding object to hit?  Did Uranus have a significant solid mass at one time?  Is this a function of the speeds that would have been involved (sort of akin to skipping rocks on a pond, if that's a relevant analogy)?
Comment: "If Uranus is a ball of gas" [It's not](https://en.wikipedia.org/wiki/Uranus#Internal_structure).
Comment: Thanks for the clarification!
Answer: For objects on the scale of a planet, the state of matter doesn't really matter much.  A colliding planet or planetesimal would not "just pass through"  The amount and density of the gas would prevent that.
Some easy experiments:  Put your hand outside a car as you are driving along, you'll feel that "gas" (ie air) has real substance and pushes against your hand quite hard.  Now imagine that you are driving at 20 km/s.... What happens when a piece of rock from space hits the atmosphere? It doesn't just pass through, it burns up in the air as a meteor.
Moreover the pressure and density in Uranus is huge.  Not so far below the surface are layers of water,ice, ammonia, methane.  And the pressure is so great that the density is more that that of water.
The collision of two gas planets could result in a combined planet that had a rotation axis inclinded at 90 degrees or more, and tidal effects and equatorial bulge effects would pull the moons into orbits around the equator.
Comment: I don't quite see how this answers the OP. They asked "How is it possible ..." This answer essentially says "It could be possible". It's possible because of the gyroscope effect, where applying an off-center force to a spinning body causes it's rotational axis to change according to right hand rule. See https://en.wikipedia.org/wiki/Gyroscope
Comment: @andy256 It's answering the "why doesn't it just pass through" part of the question.
Comment: @andy256 That part I get, actually.  Maybe I could have worded my question (which I think James answered fairly understandably) better, but my confusion/lack of understanding was related specifically to the not-solid part of it.


Install Firefox addon in chroot environment

Question: My goal is to install some Firefox addon inside some chroot environment.
I see 2 options here: either run firefox with X from within the chroot and install the addons or put all the files where they need to be.
For the first option I did set the DISPLAY variable and allowed connection from localhost with xhost +local. I can now run graphical software like the calculator.. Bur when I try to run firefox I get some errors:
<code>dbus-laucnh terminated abnormally with the following error: EOF in dbus-laucnh reading address from bus daemon
</code>
So I tried the second option and placed the .xpi file in .mozilla/extensions but this has no effect
Any ideas?
Answer: According to your error message you might wanna try bind-mounting your Dbus sockets inside the chroot in order to communicate with the host.


Generatos of non-abelian Galois group of order 8.

Question: Trying to find generators of Galois group of K:Q where K is the splitting field for $x^4 - 6x^2 -2$. I have the four roots (plus minus $\alpha$ and plus minus $\beta$) and K is generated by $\alpha$ and the product $\alpha\beta=i\sqrt2 $. I have found all the elements and the order, however, I am stuck on trying to find the generators of the group? My next task is to list all the subgroups and find the subfields. Any help will be greatly appreciated.
Answer: Hint: $Gal(K/\mathbb Q)$ must be the dihedral group of order 8 from Kaplansky's Theorem. Therefore, it must be generated by some $\rho$ and $\tau$ where $\tau^2 = 1$, $\rho^4 = 1$ and $\rho\tau = \tau\rho^{-1}$.
Comment: I have τ2 that fixes alfa and sends αβ to -αβ. However, the only generator of order 4 I can think of is such that sends α to β=(i(2)^(1/2)/α) and sends αβ to 1/αβ. Can't figure out how else to get rid of the i(2)^(1/2). However, 1/αβ is not a root.
Comment: Also, the action of the group on the four zeros is faithful. So the group is isomorphic to a subgroup of $S_4$. Because the order is 8, it is a Sylow 2-subgroup, and hence isomorphic to $D_4$. Nothing wrong with your approach either :-)


Ubuntu 12.04 low screen resolution

Question: After installing Ubuntu 12.04LTS I tried to change my screen resolution from 640 by 480 to the one suitable for my system but discovered that I cannot. I tried xrandr but it did not work out. Please what can I do to get the best resolution for my system. The resolution I use on windows is 1280 by 800. How can I get same on Ubuntu or something close to that as the maximum resolution on my linux is the 640 by 480?
Answer: Go to the top left (in unity) and search for 'additional drivers'. Install the recommended or proprietary drivers. You might have to reboot. If this doesn't work, add a comment on this answer and I'll try again.

Ubuntu 12.04 low screen resolution


Would using direct connections on an exit be safe?

Question: Let's say the computer I'm using is an exit. If I don't use Tor for my own browsing, can we consider it safe because those connections will blend in with other connections that exit?
Answer: This is safe in terms of the fact that there are no new attacks that can target you direct connections. In other words, running an exit node does not correlate to someone being able to sniff your traffic.
This is also safe if you mean, as you say, you'd like to blend your traffic in with the exit node traffic. It would be difficult for an attacker (like an ISP) to differentiate Tor exit node traffic and your personal traffic.
That being said, it does not really offer true traffic analysis protections because you're not actually routing across the Tor network. You're taking the plausible deniability route in this case but don't have much science/tech to back it up.
In short, safe - yes for some definitions. Smart, probably not.
This FAQ covers the topic a bit.
https://www.torproject.org/docs/faq.html.en#BetterAnonymity
Comment: So my ins and outs can be watched and distinguished? Aren't the information sent between relays encrypted? I assume that if they were, routing across the Tor wouldn't matter. Many encrypted ins, many outs. Who would know who requested what?
Answer: I don't think it would be "safe" - you would have less anonymity.
Consider the case of an adversary who can watch your connection to the internet, e.g. your ISP. Such an adversary might sometimes observe a lack of correlation between encrypted tor traffic going into your node and traffic leaving your connection, and guess that you - rather than other tor users - are the origin of that traffic.
How easy it would be for an adversary to distinguish between tor-exit traffic and your own traffic probably depends on how busy your exit node is, but I definitely think it would be less safe than using tor.
Comment: They can make a guess, but can they know? I mean even if I don't do anything illegal, but someone who is doing something illegal uses my exit (ExitNodes in torrc), I still could get police at my door. Even if a specific site was only accessed from my exit (maybe some unlisted addresses, which used only by some company's IT team), they still wouldn't be able to prove anything.
Answer: If you're trying to disguise as an exit-node, to post to some blog or whatsoever it's alright.
If you're logging into Facebook, Google, or anything that is linked to you.   Bad idea, and isn't safe.
Answer: The IP used by an exit is an information that you don't want to be linked to yourself, and that's precisely the whole purpose of the Tor software. Therefore, I would say that it is unsafe.
Answer: This depends on your threat model and your intended use.
For example
If your intended use is to post to the same site every day, and you are doing from your computer which is also being used as an exit node. Then every day the site owner would know that someone is connecting from your computer and posting every day. The chances of this being someone connecting over tor and by random chance always connecting to your exit node, are very slim, so they would easily know it is you.
- not safe
If your intended use is to make a single post and never go back, then they would see it is from your computer, and you would have plausible deniability as you could say it came from someone over tor. But if instead you just used to to make the post, then you wouldn't even need plausible deniability as it wouldn't be linked to your computer at all.
- less safe
Comment: Tor allows its users to pick an exit instead of letting it choose a random one. So in the first example, maybe someone picked my exit and they are doing their dirty stuff from my exit all the time.


does なんだこれは specifically have a bad connotation?

Question: I heard this and wasn't sure if it had a negative meaning or not. Does the phrase always indicate irritation or not necessarily? I'm a bit confused since some people say it's just an informal tone between friends, and some say it's said due to frustration?
Can anyone clarify please?
Thanks!
Answer: The word order conveys some meaning.
Normally you would say: それはなんですか?
By putting なんだ at the beginning it conveys the idea of surprise (either good or bad). Not being polite-speech also comes up as rougher or more direct (like saying something crudely without thinking about how you say it).
I guess it depends on the tone similarly to the english "what is this?". But surely you got "surprise + informal" for sure.
Answer: なんだこれは is not necessarily negative, but it does indicate the speaker is surprised or amazed, like "What the heck is this?".
For one thing, だ is not really a common copula in ordinary informal speech. When it's used, it would sound masculine, blunt, urgent and/or oppressive. For example, you should use the question "誰だ?" only against a highly suspicious person like an intruder.

を+[する noun] + だ structrure?
What is the difference between 何だと and 何ですと?
~たいだとか why is there a だ here?

For another thing, the reversed word order adds a dramatic feel to it, as pointed by another answer.


Many-to-many relation (playa?) with additional data

Question: I have a channel called "Courses" and it is using Matrix to have several "Lessons". I use Zoo Visitors, so I have members as channel entries. When a member signs up for a course, I want to follow if he/she completed the lessons of the course. When he/she completes all lessons under that course, then the course also will be marked as completed for this user. I can imagine how this would be done using database tables, but do you think if it can be handled using just channels/matrix/playa? Or module should be developed?
Answer: In theory that sounds possible. You'd probably have to create some custom fields in the Member channel (possibly again with Matrix) so you can assign "Courses" and the corresponding "Lessons" to them. You could then include a column for "Status" and indicate whether it's "not started", "started", or "complete". On the front-end you can then use a Safecracker form to change the status once the course has been completed. This could be either a hidden submission or a manual user action to indicate that they've completed the course.
I think the problem would be that in the Member entry you'd need to track Courses and Lessons separately so that each could have a status. I'm not sure that would work in a single Matrix field(?)
No doubt you'd get a better result with a custom module but it would also take considerably longer to put together so it's a tradeoff between whether you can get something to work with what you have (albeit maybe not quite tailored how you would like it in an ideal world) versus the time (and/or cost) it would take to put together a custom module.
Answer: I've actually built exactly this. In my Zoo Visitor fields I have the following fields:

1x Playa Single Select for "Active Course"
1x Playa Single Select for "Active Lesson"
1x Matrix, with Playa Single Selects for "Finished Courses"

The next Lesson is selected based on a sort of "id" they all have, which are sequential.
Comment: Thx for the idea, but in my case lessons are not sequential. User can open start but not finish more than one lesson, and the lessons are not sequential.
Comment: I think in this case ExpressionEngine might not be the best fit, don't you think you'd be better of with a custom CodeIgniter (or Ruby on Rails) app?


What are the Golden Chests for and where are the Moon ones?

Question: I found a Golden Chest on the Moon. Is it just for simple loot? Are there others on the moon? How many are there?
Answer: Golden Chests just contain loot, yes. It's also worth noting that they scale on the area, not your level. So it's best to find them asap. You also are given an item for finding all the golden chests on a single planet. I know that you get a Sparrow from Earth and an Emblem from the Moon.
There's a few on each of the planets in-game at the moment. There are 5 on the moon
1 - Found during the The World's Grave mission inside the cave full of cocoons.
2 - Head to the mission marker located in the large yellow building. Proceed until you find the green gas pit. Look nearby for a rock formation and orange lights.
3 - Another in The World's Grave. When defending your Ghost search a nearby room with a little pool of water
4 - Inside the Temple of Crota during the Chamber of Night mission.
5 - The Summoning Pits Strike mission. After the final boss fight walk to the edge of the room and drop down onto a small platform
I'm affiliated with Gamers Heroes and we have a guide on the topic should you need more direction: Destiny Gold Chests Moon
Comment: just want to add that the item you get out of them is not random, it's a predetermined item at each chest
Comment: And said predetermined items don't scale to level. So there's no point in waiting, as I've seen some people are led to believe.


How do I install a wall mount lighting fixture when there are 2 black 2 white and 2 ground wires from the wall

Question: I'm installing 2 wall mount light fixtures, the first one was easy it was just one for one with black,white, and ground.  The second box in the wall though is pre-wired with 2 black, 2 white, and 2 ground.  My question is, do I connect all 3 of each together.  Attached is a picture of the wiring coming out of the box.
Answer: It appears likely that one cable, with a black, white and ground, is the feed (source of power), and the other is a pass through to the next fixture or outlet.
In that case, you would simply join your fixtures wires to the existing bundles, matching colors.
This assumes that switching is already in place, or the fixture has internal switches.
Comment: That's exactly what it was, thank you for the help.


Is it possible to use the phrase 'Suit yourself' with other reflexive pronouns?

Question: Some dictionaries list the phrase in the generic form of 'Suit oneself' (e.g. Merriam-Webster). Although I have come across the phrase 'Suit yourself' many times, I haven't seen any example usage for other reflexive pronouns like themselves. Is it possible to use the phrase like 'Suit themselves' to mean 'I don't agree but they can do whatever they want'?
Comment: You can say that "they may suit themselves" without problems,
Answer: No: "suit themselves" is not a grammatical sentence.
Suit in "suit yourself" is in the imperative mood: it's telling your interlocutor to do something. You can only tell someone to do something if you are addressing them directly. The reflexive pronoun yourself refers to the person you're addressing.
With themselves, you are talking about people, not to them. So you can't use an imperative verb. You would need to say something like "They can suit themselves," using an indicative form.
Comment: Thank you for the clarification. I'm unable to upvote your answer because I don't have enough reputation. I hope somebody does it on behalf of me.


Make isearch commands search only at the beginning of words

Question: How to make C-s (isearch-forward) and C-r (isearch-backward) search only for words that start with the argument passed to them, instead of searching for the argument even if it's in the middle of a word?
Comment: For 2) see section "Position of the Cursor after Searching" here https://www.emacswiki.org/emacs/IncrementalSearch
Comment: Please post two separate questions for your two separate question. As it stands now, the question is too broad and may be deleted.
Answer: You can either toggle word-search-mode by doing M-s w after starting isearch, or you can use start in word search mode directly using isearch-forward-word, also bound to M-s w.
Comment: `isearch-backward-word` doesn't exist, but you can do `C-r M-s w`, or write it and choose your own binding. Once you're in word mode you can just use `C-s` or `C-r` to go to the next match.
Comment: I tried it first, but unfortunately, it doesn't seem to have an equivalent `isearch-backward-word`. And it only shows the first matched word, with no way (apparently) to go to the next match.
Answer: word-search-mode is the usual way to constrain your searches to words rather than letters, as @rpluim shows.
An alternative, more general approach is to use regular expression searches, isearch-forward-regexp, or C-M-s, and also the reverse isearch-backward-regexp and C-M-r. You can then use a regular expression to limit your search: \bin will match in when it occurs at the start of a word.
This is not as convenient as word-search-mode, but it is more flexible. For instance, you could find words ending with er with er\b.
Answer: Here's what I use to do this
;; Use isearch-forward-word by default (treats a space as any whitespace or punctuation)
(global-set-key (kbd "C-s") 'isearch-forward-word)
;; This is the same as isearch-forward-word except with the first argument to
;; isesarch-mode set to nil to do reverse search
(defun isearch-backward-word (&optional not-word no-recursive-edit)
  "Do incremental search backward for a sequence of words.
With a prefix argument, do a regular string search instead.
Like ordinary incremental search except that your input is treated
as a sequence of words without regard to how the words are separated.
See the command `isearch-forward' for more information.
This command does not support character folding, and lax space matching
has no effect on it."
  (interactive "P\np")
  (isearch-mode nil nil nil (not no-recursive-edit) (null not-word)))
(global-set-key (kbd "C-r") 'isearch-backward-word)

isearch-backward-word doesn't exist so I just copied the source of isearch-forward-word and changed the first argument of isearch-mode to nil to do reverse isearch.


Would this Vivitar 75-205mm 1:3.8 macro lens fit on Nikon D610 dslr?

Question: would the lens pictured (Vivitar 75-205mm 1:3.8 macro focusing lens) fit on a Nikon D610 dslr? thank you!
Answer: The photo is a little fuzzy, so I am not positive, but that looks to be a Pentax K mount. It will not fit without the help of an adapter like this.