Car parked for twelve years?

Question: I really need help with this. We have several cars parked in our yard, 3 pick ups, 2 vans, a sedan and a ford bronco 2. Some (the trucks and ford) have been sitting in the same place for going on 12 Years!  Empty gas tanks, no starting the engines, no movement. One of us (not me) wants to keep them, because they may be collectible and worth something. Accept they're all wrecked or broken in someway. "I just need to fix one thing and we can sell it," he says, for years now. How can I convince him mechanically that they need to go? I just want a  clear driveway! None of our kids have ever known what it's like to park close to the house! to clarify, I would most appreciate a list of all the things that will go wrong to a vehicle parked for so long. I've seen the posts here concerning cars parked for several months, but for a decade?  Please help!
Comment: It,s frustrating cuz he's in denial that he's hoarding these things. If I could just get a list of things that could happen to cars parked for so long, it would go a long way towards building a case
Comment: You might need a site that is more focused on psychology :) but my argument for it would be simpler - if they each only have one thing wrong then sell it with the fault for the value of the car less the cost of repairing the fault. In actual fact it won't be one fault but several causes by years of lack of use
Answer: You won't convince him on a mechanical level, because he'll just lie to you about the state of the car, and you won't have enough knowledge to call him out on it.
Instead, turn it back on him.
"I just need to fix one thing and we can sell it,"
OK. Fix that one thing, and sell it by the end of the week/month.
"But I don't have time to do that"
Sell it as-is, and let the new owner fix 'that one thing'
"But we won't get as much for the car"
But we won't be paying for parts to fix it.
Don't accept the argument of 'they might be collectable'. The only collection going on is rust. Cars - especially common ones - don't become collectable when they're sitting in the open.
Of course, if you name is on the title with a 'OR' modifier, you can sell them without his agreement anyway...
Comment: I appreciate you being my first ever answer, cynical though it may be. I'm not worried about him lying about it. We're both firm believers in Jesus, and the poor man doesn't know how to lie anyway. The thing is, I would and do know enough mechanics to point out the issues, but he's had real mechanic friends tell him to just fix the one thing. But they're just agreeing with him to be nice or something, cuz they don't want to disappoint him?Who knows?  I just need a list of issues to point out from an un-biased third party. Like a second opinion.
Comment: What is the reasonable total worth of the vehicles, if they were all in average running condition? Now halve it. Now ask if you really need that amount of money - are you struggling to afford food/pay bills etc or if they were all just scooped up in the night and disappeared would you not yearn for anything? If the latter then you don't really need to sell them at all; they could be towed for scrap and you still wouldn't miss the amount of money they wouldn't realize, because you haven't needed that money for years - you've clearly just obtained another vehicle rather than "fix one thing"..
Comment: ..so I'm guessing you're not poor or struggling. As such, sell them for what they're worth now and look at it as a bonus; all he's doing with the "but I could get more for them" is finding an excuse to avoid letting them go because they're some sort of comfort for a problem that lies elsewhere. Every time he passes a shop that sells lottery tickets, doesn't buy a ticket and then watches the results saying "if I'd bought a ticket I could have won that" he's doing the same thing, and I bet he passes a lot of stores, doesn't buy because he recognizes the unlikeliness, but doesn't see it outside
Comment: Irrelevant in the USA, but in the UK there is a tiny specialized market for this sort of thing, for people who want to design and build a completely custom but road-legal vehicle. Because of a "feature" in UK vehicle law, it is much easier to "modify" an existing non-scrapped vehicle than start from "nothing". The only essential items for this are the vehicle registration documents and the physical VIN plates from the original vehicle, but most people would use the original chassis or subframe as well.
Answer: I'm reasonably certain that taking a photo on your cellphone and then visiting the local car dealership or even wreckers yard with a "give me your best cash price for these; why is your offer so low" will produce an even longer list of excuses and barter-downs than I can think of here (especially as he will know the toll your climate has on vehicles) but a car that is parked up exposed to the elements for a long time will likely need the following considering to be restored to service:

new battery - they self discharge at varying rates and once 5ey drop below around 70 percent charge they're well on the way to being goosed
full change of all fluids and consumables that would be done in a service (paper filters degrade, oils degrade especially if they've been in service prior and acquired moisture and acidity from combustion by products, waters stagnate and block with algae if the appropriate chemicals aren't added)
air con systems usually get ruined by lack of use as regular pumping of the refrigerant is vital to keeping seals in good condition
rubber becomes harder and brittle with oil contamination and sunlight exposure; gaiters, pipes, new set of tyres especially if any have gone flat and perished the side walls. Rubbers and plastics especially in the cab exposed to day heat, lose their plasticisers and become brittle
mold takes over every surface regularly touched by humans; radio knobs, indicators etc become sticky and slimy especially for cars parked in the shade
wires corrode where different metals (eg aluminium connectors on copper wires) are in contact - this is electrolytic and independent of climate, but also repeated cycles of condensation and other climate effects have a corrosive nature.
full check over for the effects gnawing animals have on pipes and wires
check and replace moving parts and safety parts, particularly on the underside, that will have become encrusted with road salt or mud during service and subject to hidden corrosion thanks to acidity or alkalinity - no one power washes all the dirt off the brake lines before they park their car up for 12 years

Parts of cars that are regularly driven get warm and the residual heat can combat a lot of the environmental effects, meaning that regularly used cars last longer in practice than those left to fester. In realistic terms anyone who knows their salt will understand they're potentially buying a huge can of worms - a car parked up because it has a broken driveshaft and left for 10 years will need more than just a new driveshaft and it should be priced accordingly; I'd be looking to bid scrap value because if it did turn out to be a write off I could maybe recover my outlay by selling usable parts
If you want a real life appraisal of worth put one on eBay with a very high reserve (so you don't have to part with it come auction end) and honestly List every fault and circumstance relevant to the car. Maybe don't set a reserve actually, just sell one and note the difference between what you think it's worth and what the market actually pays - it will likely be quite a stark difference
Comment: IMO if you can find a scrap car dealer who will take them away and handle with the paperwork for scrapping them for free, you probably got a good deal. Realistically you are looking a minimum of hundreds of dollars per car to get them running, and a lot more if you find any problems. Nobody who wants to buy a car to *use* it is going to take that sort of risk.
Comment: Thank you so kindly for all the answers, everyone!  I think my next step is to talk to our mechanic friend to let him know that he's not helping the situation by saying the cars can be fixed. I know he'd help me be more convincing once he knows my opinion on the matter
Comment: He could certainly be a help; get him round and ask him how much he'll buy the first car for. Then how much will he give for it if it were in running and resale-able condition. Finally, how much to fix it... Do the math and see whether it's worth paying him to fix them before you sell them, if "fixing it so we can get more money for it" is the only thing holding up the sale
Comment: Dont forget the rusty fuel system, they corrode like crazy after setting 12 years, new gas tank, fuel pump, carb rebuild or new injectors, etc.
Comment: I'll take the point about the gas tank, maybe fuel pump and carb.. Carbs tend to be a nightmare if they aren't drained before storage. Not sure I've ever had a problem with long parked fuel injected cars from an injector viewpoint, gas or diesel..

Car parked for twelve years?


Chrome not starting after auto-login

Question: My Ubuntu 16.04 machine is configured to automatically log in. After it automatically logs in, I use TeamViewer to access the machine and try to open Chrome by clicking on the icon on the side bar. The icon flashes for 30 seconds then stops, and Chrome never opens.
This seems to be connected to gnome-keyring-daemon. Immediately after I log in, I see that gnome-keyring-daemon is running:

$ ps aux | grep keyring
kyle      1532  0.0  0.0 214384 10956 ?        Sl   14:20   0:00 /usr/bin/gnome-keyring-daemon --start --components=secrets

And it should open when I click Chrome, but it doesn't. I know this because if I try to load Chrome from the command line I see this error:

$ google-chrome
google-chrome
Gkr-Message: secret service operation failed: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

If I open a Terminal while using TeamViewer and manually run killall gnome-keyring-daemon, then the "Unlock your keyring" window pops up after clicking on Chrome and Chrome opens.
I saw some indication that dbus-user-session was responsible for this problem, but it is not installed on my system.
I saw another post where someone edited /etc/pam.d/lightdm but this didn't fix the problem either.
Is there a real way to fix this, or do I have to killall gnome-keyring-daemon every time after startup?
Comment: Does this help https://askubuntu.com/a/823975/689314
Answer: I tried a bunch of different things, but in the end my solution is just adding:
killall gnome-keyring-daemon
gnome-keyring-daemon --replace

To /etc/rc.local
Now Chrome asks for a password the first time it opens, as I would expect.

Chrome not starting after auto-login


Asp.net MVC 4 dynamic server and client side validation

Question: My company is developing a multitenancy application that has to be fully customizable through the database. This includes validation, so i created a couple of tables containing information about jquery validation methods and the way they are to be assigned to properties.
I have disabled automatic property validation generation, and marked each relevant property with an attribute that correctly generates multiple client side validation rules. However, the problem arises when i have to validate the model on the server side. I have implemented validations for required, digits and number, however i am not satisfied with that solution.
Is there a way to dynamically link my custom validation attribute with built in attributes? The general idea is that my custom validator would recieve a set of required validation methods from the database, and would propagate the validation check to the built in MVC validation method so I don't have to implement it.
Sorry for not posting the code, but I'm not allowed to do it. I would still appreciate a general guideline if this is doable in MVC.
Thank you

Update:
My attribute extends ValidationAttribute and IClientValidatable.
Client side validation is not a problem.  IClientValidatable returns an enumeration of ModelClientValidationRule that MVC flawlessly translates into proper jquery validation rules. Database stores jquery validation method names, such as 'digits', 'number', etc, along with method parameters.
My problem is with the "public override bool IsValid" method. I can get the list of jquery validations to perform, but i have to manually implement validation methods. Basically, I want to check the validation rule and if it equals 'required', I want MVC's RequiredAttribute validation to be performed.
Answer: I did that before, create your own validation attribute that will depend on DB info to validate data , also create custom helper to render correct client side validation depending on that attribute value
Comment: So you know already what to do just create your ValidationAttribute inhirreted from Attributes and code it, or you need to be more spesific of what is stopping you


Four partly trivial concerns on the last paragraph of the following passage

Question:
Lindsey Aloia (Rollins College) and Denise Solomon (The Pennsylvania State University) published their findings in the journal Human Communication Research. Aloia and Solomon studied 50 romantically involved couples and found that the more intense the conflict interaction was rated between the couples the stronger the physiological stress response to the conflict. This relationship, however, was weakened for individuals who reported a higher level of childhood exposure to verbal aggression.
For the experiment the couples provided saliva samples to determine their baseline cortisol levels. They were then interviewed separately about the most stressful areas of conflict in their relationship and filled out a questionnaire that asked about their childhood experiences with verbal aggression. Following the interview, partners were asked to sit together and discuss an area of conflict alone for 10 minutes. The sessions were videotaped. After the discussion the couples were separated again and provided two additional saliva samples over a period of 20 minutes after the conflict. Trained judges then watched video recordings of the couples and rated the intensity of the conflict communication of each couple. Finally, cortisol levels were calculated to evaluate experiences of stress using the collected saliva samples.
Previous research has examined the experience of conflict within a multitude of relationships. These studies make it clear that conflict can produce a number of negative outcomes. For example, exposure to conflict has been linked to depression, distress, and anxiety; feelings of hurt and anger; relationship dissatisfaction; and subsequent physical violence. Recent efforts point to the role of physiological processes in understanding the variation in individuals' experiences of interpersonal conflict.
Considering the physiological implications for stress and viewing interpersonal conflict interactions as potential stressors highlights how experiences of conflict are shaped by both the demands of the interaction and people's adaptive capacity to handle that stressor. "Conflict experiences can be beneficial, by alleviating tension and avoiding conflict escalation, reducing communication apprehension, and contributing to closeness within the relationship," said Aloia. "Given the diversity of outcomes associated with interpersonal conflict, efforts to understand variation in the experienced negativity of conflict experiences are extremely important in helping people navigate these interactions."

Does the word for in last paragraph mean caused by / coming from ?

Does the demands of interaction mean the severe and hardship of interaction?

What does this part mean : contributing to closeness within the relationship ?

Is the word research in third paragraph plural and uncountable and is about more than one research?

A million thanks in advance. I did want to ask separate questions but some of them are really trivial. Please do not vote down.
Answer: The first sentence should read (the original is using "for" rather loosely):
Considering the physiological implications of stress....
The demands of the interaction means "what the interaction requires (emotionally) of the person who is interacting"
"Contributing to closeness within the relationship" means "conducing to intimacy/bonding"
Answer: Is the word research in third paragraph plural and uncountable and is about more than one research?
In the sentence alone, it is ambiguous and uncountable, with the implication that it's plural. The next sentence, which starts with "These studies," indicates clearly that "research" is meant to be plural. "Research" and "studies" are being used somewhat interchangeably, in these two sentences.


What do you call the page you can bring to exams?

Question: On an exam, you can often bring one A4 sized piece of paper that you can write anything on.
What's that piece of paper called in this context?
Comment: It isn't clear to me whether the OP refers to a blank sheet of paper for rough work or a sheet of paper containing information which will be useful during the exams.
Answer: Such a reference is known as a cheatsheet or your crib notes.
Note that the paper may be called a cheatsheet even if its use is sanctioned and you're not cheating by using it. Similarly, a crib note doesn't necessarily need to be cribbed.
Per Wikipedia:

A cheat sheet or crib sheet is a concise set of notes used for quick reference. "Cheat sheet" may also be rendered "cheatsheet".
Cheat sheets are so named because they may be used by students without the instructor's knowledge to cheat on a test. However, at higher levels of education where rote memorization is not as important as in basic education, students may be permitted to consult their own notes during the exam (which is not considered cheating). The act of preparing a so-called cheat sheet is also an educational exercise, thus students are sometimes only allowed to use cheat sheets they have written themselves. In such usage, a cheat sheet is a physical piece of paper, often filled with equations and/or facts in compressed writing. Modern students often print cheat sheets in extremely small font, fitting an entire page of notes in the palm of their hands during the exam.
Comment: It's totally unheard of in Britain, in any exams with which I have been involved. Students are allowed to take a basic calculator into Maths exams. And in the days when I was at school (over half a century ago) you were given a set of logarithm, trigonometric, and square/cube root tables for use in the exam. In my recent university experience, reading History, a minority of question papers were handed out a couple of days in advance so that one could prepare essay answers in advance, but one was not allowed to take any notes into the examination room.
Comment: It's normal for some exams to include a basic information sheet (eg of formulas in GCSE maths).
Comment: @EdwinAshworth For the GCSE, can the student bring in his own page of notes? Or is the info sheet standardized and distributed by the faculty?
Comment: The latter; I was just giving a fairer picture of the actual situation than the above comment.
Comment: @Edwin Thanks; and I imagine the situation is even more liberal than that. *Some* British professors must allow crib notes during exams: read the final para of the intro in the linked Wikipedia article: "*The term can also apply to the fully worked solution for exams or work sheets normally handed out to university staff to ease marking.*". Some BrE speaker wrote that (*fully worked* vs *worked out*, *marking* vs *grading* and maybe even *university staff* vs *the university's staff*).


Why is Hawkeye using a sword instead of bow and arrows?

Question: In the Avengers: Endgame trailer, Hawkeye is using a sword instead of bow and arrows. Why?
Comment: @I Love You 3000: Is there anything more I can add to my answer to improve it for you?
Comment: And I repeat that question. :)
Answer: Based on the use of a sword, and his changed costume, there's a good chance that he's using the Ronin persona introduced in New Avengers. There, he was borrowing the identity from Echo because he was assumed dead at the time, but here it may be a matter of him dodging the fact that he's supposed to be retired.

This has been confirmed, although the name did not wind up being used in the movie.

After being nowhere to be found in Avengers: Infinity War, Hawkeye is front and center again in Avengers: Endgame. Unfortunately for Clint Barton, losing his family thanks to Thanos' snap drives him a little bonkers, and he spends a little time running around the MCU in a black costume, wiping out criminals with a samurai sword, under the moniker of Ronin (even though that name is never actually said in the movie).
Comment: {nods} I guess I can accept that. It just seemed such a clear reference that it was worth mentioning.
Comment: This might end up being the case, and in my opinion is probably on the right track. But until the movie is released it's just speculation.
Comment: You might also note that (in the comics) Hawkeye's original mentor was a guy named the Swordsman. While he's incredible with arrows, he's probably gotten some decent training with a sword as well. Admittedly, that bit of personal history isn't part of the MCU at this time, but it hasn't been explicitly invalidated either.
Comment: (Plus, the mask he's looking at looks similar to the Ronin mask.)


Paint refresh problem in Java 1.6 Swing app

Question: I'm working on a Swing application (currently running on Java 1.6 update 11) which has some intermittent paint refresh problems (e.g. there are artifacts etc.). This only happens to some users of our application but not others.
After doing some research, I found that setting the property sun.java2d.d3d to false may help and in fact, it helped for one of our users.
Now that some other users are complaining about the issue, I'm thinking of setting the property to false for all users.
My basic questions are the following:
What exactly is the cause of this? Is it the video card? Is it the driver? Is it a bug from Sun (such as JDK-6635462 : D3D: REGRESSION: XOR rendering is extremly slow)? Combination of all three?
In other words, is is best to simply turn this property off or is it affecting only certain video cards in which an update to the latest driver would fix?
Comment: This issue frequently occurs when running Java inside VMWare.
Answer: Java introduced in R6 update 10 a pipeline that renders graphics based on Direct3D. According to the release description here it supports only NVidia and ATI cards, which means anyone not using those cards may have a problem. Since it is a recent innovation I would suggest that anyone using old drivers for those cards may also have problems. Upgrading a video driver will probably fix the first case but not the last.
If you set sun.java2d.d3d to false the worst that can happen is that some users will not achieve the performance that they theoretically could. You will have to balance whether this is preferable to the issues that you are seeing at the moment.
Comment: The user who first had the issue had an ATI Radeon XPress 200 but I did not check whether they had the latest driver.
The application is a pretty "standard" Swing app, i.e. no 3D operations or "out of the ordinary" paint operations.
Comment: One would think that it would auto turn off for unsupported video cards, assuming that were possible.
Answer: Are all painting and model changing operations execute on EDT (e.g. changing TableModel etc.)?


Traveling to mexico without visa. Do I need a return ticket?

Question: I will be travelling to Mexico as a tourist (without visa), and I would like to know if I can just buy a one-way ticket for now and then get the return ticket later.
Thanks!
Comment: Where are you travelling from? And how long are you planning on staying in Mexico?
Comment: From Spain, and the plan is to find some job there to stay for a long period (couple of years probably)
Answer: While Mexico offers visa-free entry to nationals of many country, border authorities can, and do, ask for itinerary information, including proof of onward travel (added emphasis mine):

Instituto Nacional de Migración
Countries and regions that do not require a visa to travel to Mexico
The nationals of the following countries or regions do not require a visa to travel to Mexico and apply for admission as a visitor without permission to perform remunerated activities.
In the migratory review filter, they must present:

Passport or identity document and valid travel that is valid according to international law.
FMM duly completed.
The immigration authority may request the foreign person to verify the reason for their trip, by means of any of the following documents:
a) Hotel reservation, return tickets (itinerary), tour tickets (itinerary).
b) A mandate letter in Spanish language of the parent company, subsidiary or foreign subsidiary that indicates that the foreign person is employed by it and that the payment of the services it will provide in the national territory will be paid by the same.
c) Copy of the technology transfer contract, patents and trademarks, purchase and sale of machinery and equipment, technical training of personnel, or any other related to the production process of a company established in Mexico or linking to the foreign party with the Mexican party, or proof of appointment by the shareholders' meeting of companies legally established in Mexico.
d) Letter from an organization or public or private institution inviting the foreign person to participate in any unpaid activity in the national territory, state the purpose of the visit and the estimated time of stay. In the event that the organization or institution pays the expenses of travel and permanence of the foreign person in the national territory, a responsive letter must be attached.
e) Letter of invitation or acceptance from an institution belonging to the National Educational System to carry out courses, studies or research or training projects for a maximum period of one hundred and eighty days.
Answer: When traveling to Mexico as a tourist, there are two points where you might be asked to show a return or onward ticket: By the airline when checking in, and/or by the immigration officer upon arrival. Some airlines are more strict than others; I've never been asked by Interjet. In the worst case you might have to buy a return ticket on the spot to be allowed to board your plane. Google "proof of onward travel" for possible ways to handle this.


What does the "PLT" in PLT-Scheme (now called Racket) stand for?

Question: I'm curious: what does the "PLT" in PLT-Scheme (now called racket) stand for?  The closest I could come to an answer was that ""PLT" refers to the group that is the core of the Racket development team" on this page.
Answer: No one is really sure but this might enlighten you.

EDIT
Because link only answers are never a good idea
PLT was never a defined acronym. Originally the designers were part of the Rice Universities Programming Language Team, but once the team expanded past this the acronym no longer fit. Even having no full form, the name stuck around. (for a while, it's now Racket)
Comment: Funny that - an odd ```)``` brace ruining a Scheme answer.
Comment: Because the `)` in the link confused the Markdown parser into thinking that was the end of the link.
Answer: PLT stands for "Programming Languages Team". The team that originally created PLT Scheme (now Racket.)
Comment: That has not been cited. Its just a rumour. The creators were the programming language team of their university but its suggested to be an inside joke between them


Twitter web intent URL encoding not working

Question: I have no idea what I'm doing wrong here. I'm trying to encode my URL with javascript. But the URL never gets put into the tweet. I think it has something to do with some parameters in my URL having spaces.
https://twitter.com/intent/tweet?text=40%25%20Off%20Prom%20Tuxedo%20Rental&url=http%3A%2F%2Fexample.com%3A5757%2Fcoupon%3Fref_name%3DTest%20Name%26school%3DTest%20School
If I take out the %20's from my URL then it works...
https://twitter.com/intent/tweet?text=40%25%20Off%20Prom%20Tuxedo%20Rental&url=http%3A%2F%2Fexample.com%3A5757%2Fcoupon%3Fref_name%3DTestName%26school%3DTestSchool
But I need to keep those spaces in there.
This is the javascript code I have right now...
var text =  encodeURIComponent("40% Off Prom Tuxedo Rental");
var couponURL = encodeURIComponent("http://example.com/coupon/?ref_name=Test Name&school=Test School");
var twitterURL = "https://twitter.com/intent/tweet?text=";
var twitterURL = twitterURL+text+"&url="+couponURL;

Comment: did you ever find a fix for this?
Comment: I have the same problem. Any fixes till now ?
Answer: In this situation, a percentage sign equals %25, so if you want to include the spaces in your tweet link, use %2520 instead of %20. So wherever you were going to use %20, use %2520 instead.
var text =  "40% Off Prom Tuxedo Rental";
text = text.replace(/\s/g, "%2520")

Comment: Thank you!! You saved my sanity. It was driving me crazy. This worked perfectly.


Integer Linear Programming

Question: Without using a computer, I have to solve the following integer linear programming:$$\min \quad x_1+x_2+x_3$$
$$\operatorname{sub} :\begin{cases}x_1\le9\\x_2\le7\\x_3\le5\\3x_1+6x_2+8x_3=80\\x_1,x_2,x_3\in\mathbb{N}\end{cases}$$
Is there any algebraic method to compute the solution (I can't use the simplex method)?
Comment: @A.E In general the simplex method won't solve integer programming problems, unless one is lucky enough to get an integer-valued optimal solution in the relaxation.
Comment: the problem was given to my son who's 11...so I can't explain this method to him. Any ideas?
Comment: You want $x_3$ to be as big as possible, and $x_1$ to be as small as possible. Use the greedy method to find $x_3, x_2,$ and $x_1$ satisfying the equations with these criteria (not necessarily integer). Now find the best integer solution. Think about the values of the variables mod 3.
Comment: I found the solution using a computer, but what I miss is a working method which can be understood by someone who doesn't know algorithms concerning with linear programming...
Answer: The problem is beyond the typical 11-year-old but if he is bright at math you should be able to explain how to solve it.
Does he have simple algebra?
The first thing to notice is that $3x_1+6x_2$ is divisible by 3, so $80-8x_3$ must also be divisible by 3. The only two allowable $x_3$ that satisfy this are $1$ and $4$.
Say $x_3 = 1$.  Then the problem becomes minimize $x1 + x_2 +1$ with
$$
x_1 \leq 9 \\ x_2 \leq 7 \\ 3x_1 + 6x_2 = 72
$$
The last line of that says $x_1 = 24 - 2x_2$. But $x_2$ is at most $7$, so this means $x_1 \geq 10$ which contradicts $x_1 \leq 9$. So the choice $x_3 = 1$ doesn't allow a solution to the constraints at all.
Thus our solution will have $x_3 = 4$.  Then the problem becomes minimize $x1 + x_2 + 4$ with
$$
x_1 \leq 9 \\ x_2 \leq 7 \\ 3x_1 + 6x_2 = 48
$$
The last line of that says $x_1 = 16 - 2x_2$. Replace $x_1$ and the problem becomes to minimize $20-x_2$ subject to
$$
16 - 2x_2 \leq 9 \\ x_2 \leq 7 \\ 3x_1 + 6x_2 = 48 $$
The first of those equations says
$$ 2x_2 \geq 7 $$
Now because $x_2$ appears in the objective with a minus sign, we want $x_2$ to be as large as possible, thus $x_2 = 7$ and $x_1 = 2$.
So the solution will be
$$ x_1 = 2 \\ x_2 = 7 \\x_3 = 4 \\x_1+x_2+x_3 = 13$$
Answer: Yep, Peter Shor got the right approach. You also need to use divisibility concepts to reduce the amount of work. Start with $x_3=5$. This would mean that $3x_1+6x_2=40$. But this can't lead to a solution because the left-hand side is divisible by 3, but the right-hand side is not! So try $x_3=4$, which gives $3x_1+6x_2=48$, which is divisible by $3$. Now try the maximum value for $x_2$, which is 7 and that gives $x_1= 2$.
This may or may not be convincing enough as proof, depending how formally the greedy approach needs to justified. The intuition is that $x_3$ contributes the most to the equality constraint, $x_1$ the least, while their appearance in the objective function is equal, so one unit of $x_3$ "buys" 8/3 units of $x_1$ in the objective function.
But clearly, the only other choice for $x_3$ (divisibility-wise) is 1, and that can't be met by plugging even the maximum values in $x_1+2x_2=25$; the max you can get maxing both $x_1=5$ and $x_2=7$ is 19.
A similar greedy argument goes for maxing $x_2$ instead of $x_1$ (once $x_3 = 4$ is settled); One unit of $x_2$ buys two units of $x_1$ in the objective function. If instead of $x_1 = 2$, $x_2=7$ you satisfy $x_1+2x_2=16$ with $x_1=4, x_2=6$, the objective function increases (by 1).
Alternatively, this remainder optimization problem being in only two variables ($x_1$, $x_2$), you can solve it by graphing its polyhedron.

The fact that the greedy method can solve certain classes of I[L]Ps can be given quite a formal proof(s) of correctenss; see the paper by V.V. Shenmaier for example, although I don't dream to suggest that's going to be accessible to an 11-year old.

Integer Linear Programming


Add value in attribute field using arcpy

Question: I need to add values to an existing field in the attribute table. The values are to be determined by values in another field in the same attribute table. I am unable to define the values in another field in the script. Can anyone help me with it?
Answer: I've not used Arc 10.1 cursors, but it's apparently even easier there.
In 10.0, there are a few ways to go about it, but here's a basic, beginner's approach:
<code># Create a cursor on a feature class
cur = arcpy.UpdateCursor(myFeatureClass)

# Loop through the rows in the attribute table
for row in cur:
    # The variable sqMiles will get the value from the column
    # named 'Area_Miles'
    sqMiles = row.getValue('Area_Miles')
    # Calculate how many acres
    acres = (sqMiles * 640)
    # Assign the acres to a column named 'Area_Acres'
    row.setValue('Area_Acres', acres)
    # Apply the change
    cur.updateRow(row)

    # The loop will then move on to the next row/feature
</code>
A simpler, condensed version:
<code>cur = arcpy.UpdateCursor(myFeatureClass)

for row in cur:
    row.setValue('Area_Acres', row.getValue('Area_Miles') * 640)
    cur.updateRow(row)
</code>
See: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v0000003m000000
Comment: Tom, please re-write ALL of ESRI's "Help Files" using the method you used in this answer.  Then more people will understand, and the world will be a happier place.
Comment: Tom, please follow @JasonMiller 's advice. And thank you VERY much for cracking this down for us. I considered myself illiterate, but now no more.
Answer: Well, there are a few ways you can do this.

If the calculation is fairly simple, I would use the Calculate Field tool. If you need to use the code_block parameter, I'd go with option #2 as it's not always easy getting the syntax correct in a script (or in the tool itself for that matter).
If you are interested in scripting more in the future, I'd strongly recommend using cursors. You can write the values from one field into a Python list and perform your calculations on each item in the list with a for loop and then write the list back to your new field.

I rarely use Calculate Field anymore as it's easier to script cursors for all but the simplest formulas.


What happens to a graft if the "donor" dies?

Question: I've seen there are rules for grafts in case the donor "goes loud".
If the donor goes loud you loose the graft and it can have some nasty side effects. But what happens if instead he dies/is destroyed? (grafts are from the Flowers of Hell book)
Answer: You decide what happens.
Personally I lean towards using the rules for going loud. But this is based on the assumption, that if given a chance, most Demons will go loud to have a fighting chance or enable a faster escape.
But RAW there are no details as to what happens when a Demon dies. So  feel free to make something up that makes sense for your story (perhaps the graft partially transforms, it starts to deteriorate, ...).
The only detail that we do "know" is the following (Flowers of Hell p160):

A handful of demons have tried ripping pieces off of angels — or one another — to create form gadgets, but something
  about the process doesn't work.


Number of elements in a finite $\sigma$-algebra is even

Question: To prove the number of elements in a $\sigma$-algebra is even, is it enough if I argue that for every $A\in\mathcal{F}, A^c\in\mathcal{F}$, where $\mathcal{F}$ is a $\sigma$-algebra, and thus the elements have to occur in pairs? Is there a flaw with this argument?
Comment: The claim is true so long as $\mathcal{F}$ is a $\sigma$-algebra on a nonempty set. Otherwise $\emptyset=\emptyset^\mathsf{c}$ (as $\emptyset\setminus \emptyset=\emptyset$).
Comment: @Hayden yes, the underlying set is non-empty by assumption. thanks!
Answer: It is enough. Suposse you have $2n+1$ elements, then by the pigeonhole principle you can choose $n$ elements $\{x_1, \dots\ x_n\}$ such that $x_i^c \neq x_j$ for all $i,j \leq n$. This implies that that for the remaining $n+1$ elements $n$ of those are of the form $x_i^c$, so one element doesn't have an complementar in the algebra.
Comment: I feel this answer complicates the proof. The proof in question and first comment is so simple and crisp
Answer: Let $F$ be a finite $\sigma$-algebra on a set $A\ne\emptyset.$ For $x\in F$ let $g(x)=\{x,A\setminus x\}.$ Every $g(x)$ has exactly $2$ members, and if $x,y\in F$ then either $g(x)=g(y)$ or $g(x)\cap g(y)=\emptyset.$ So $\{g(x):x\in F\}$ is a $partition$ of $F$ into pairwise-disjoint $2$-member subsets.


einen Termin bei/mit jemandem

Question:
Du hast einen Termin bei/mit der Leiterin der Personalabteilung.

Which preposition is appropriate in this sentence?
Comment: Very nuanced. Mostly, they are used interchangeably but "mit" refers a bit more strongly to the person whereas "bei" refers a bit more strongly to the location (their office, but they are present). With "bei" there would be a slightly stronger expectation that others might be present.
Comment: Both are appropriate.
Comment: Is there any difference in meaning at all?
Comment: Vielen Dank! :)
Answer: Both are valid, but they have slightly different nuances in their meaning:

Termin bei der Leiterin

This includes mit, but usually means that you go to her and meet at her office. Bei most times means, that there is someone else to come to the meeting except when you ask the other person directly like:

Treffen wir uns bei Ihnen?

On the other hand:

Termin mit der Leiterin

You meet her... it is not included where in this statement. This can be your office or her office or anywhere else and if you don't say anything in addition it is normally a personal meeting without anybody else.
Comment: Vielen Dank, Torsten! :)
Answer: Expanding on Torsten's answer, there appears to be a slight semantic difference, too. Having an appointment "bei" someone implies that you come to them and it might also imply that you are not on the same level as them in some way. You don't have appointments "bei" peers, but with people who know more than you or have more power than you. An appointment "mit" implies more equality to me.

einen Termin bei/mit jemandem


How to set up external HDD to hold repositories with GitLab

Question: I'm trying to set up GitLab on Raspberry Pi 2. I have connected external HDD to the Raspberry to store the repositories.
I have mounted the external HDD to /mnt as a fuseblk file system. This can be seen in the following print given by command df -T:
    Filesystem     Type     1K-blocks    Used Available Use% Mounted on
    rootfs         rootfs     6520152 3802404   2363496  62% /
    /dev/root      ext4       6520152 3802404   2363496  62% /
    devtmpfs       devtmpfs    470368       0    470368   0% /dev
    tmpfs          tmpfs        94936     232     94704   1% /run
    tmpfs          tmpfs         5120       0      5120   0% /run/lock
    tmpfs          tmpfs       189860       0    189860   0% /run/shm
    /dev/mmcblk0p5 vfat         61302   14566     46736  24% /boot
    /dev/sda1      fuseblk  125034752   30336 125004416   1% /mnt

I configured the GitLab to store the repositories there by modifying the /etc/gitlab/gitlab.rb file and in that file changing the line with git_data_dir to git_data_dir "/mnt/gitlab/git-data".
When I run command sudo gitlab-ctl reconfigure I get the following error message:
Error executing action `create` on resource 'directory[/mnt/gitlab/git-data/repositories]'

Errno::ENOSYS
-------------
Function not implemented @ chown_internal - /mnt/gitlab/git-        data/repositories

Resource Declaration:
---------------------
# In /opt/gitlab/embedded/cookbooks/cache/cookbooks/gitlab/recipes/gitlab-shell.rb

         33:   directory repositories_path do
         34:     owner git_user
         35:     group git_group
         36:     mode "2770"
         37:     recursive true
         38:   end
         39:

I have tried searching the answer to this problem and what I found out is that this error is due to the fact that chmod doesn't work on files on the external HDD in fuseblk format. When I try chmod on any file in external HDD I get the following message:
chmod: changing permissions of `test': Function not implemented

I would like to know if there is a way to get around this or if there is some file system which I could use instead of fuseblk which would implement chmod?
Answer: After more investigation I was able to solve the problem by emptying the hdd and formating it to ext4 format which supports the chmod command. After this the gitlab reconfigure command run without errors.
I followed a tutorial which can be found here: http://www.makeuseof.com/tag/how-to-add-usb-storage-to-the-raspberry-pi/


Restricting/Disabling imessage capability on my teen's iphone

Question: I would like to protect my teen daughter by eliminating the use of imessage on her iphone. We have placed proper limits on her texting and monitor her use through our carrier. Like any resourceful teen, she now uses imessage to reach beyond the boundaries. We wish her to have opportunities to interact with friends via her phone, but we don't want it to go beyond the limits that have been set due to some past inappropriateness.
Answer: You can disable iMessages by having your teen go to settings and making all the changes she wants to the following items:

iCloud
Mail, Contacts, Calendars
Messages
Facetime
Twitter, Facebook, Flickr and Vimeo

Then you will want to observe that she turns off iMessages on the device and then lets you turn on restrictions with a PIN that you keep confidential from the teen.
In restrictions, under general in the settings app, you will want to prevent changes to Accounts about 2/3 of the way down the screen under ALLOW CHANGES text. Select "Don't Allow Changes" and then check that iMessages is now dimmed out in the settings app.
Now, that will restrict that one app - however there are hundreds of app store apps that allow chatting and you might have to consider also preventing app store installs entirely to mitigate that risk. However, with phones and iPods getting cheaper and cheaper, if a teen wants to communicate, it's going to be hard to prevent that with policies and technological efforts that are more geared for toddlers and pre-teens.
Good luck reaching some balance of control and trust going forward.
Comment: Spoken as true parent :)
Answer: To disable iMessage on an iPhone. Within Settings...

Go into Messages and turn iMessage off.
Go into General and Restrictions. Enable Restrictions and enter a passcode, then near the bottom under "ALLOW CHANGES" go into Accounts and select "Don't allow changes".

The second step is the important one. The first step is easy to reverse, but the second one will prevent anyone from reversing it without knowing the passcode.


Will there be the normal GNOME desktop available for download

Question: Will we have a GNOME version of Ubuntu available for download like Kubuntu is for KDE and Xubuntu is for Xfce. Maybe something like 'Gubuntu' for GNOME
Comment: It's unclear what this question means by "normal GNOME desktop". Is it asking about the desktop environment or the shell? The former is already included, but the latter could mean Unity, GNOME Shell, GNOME Classic, etc.
Answer: "GNOME version of Ubuntu" is not a good definition, since the default Unity variant will also be using GNOME extensively (but not GNOME Shell). Unity and GNOME are not mutually exclusive.
If you mean a non-Unity GNOME version, it won't be "available for download", but on the CD and installed by default, since it will be the fallback for systems that can't run Unity.
Comment: As for the latter point, Ubuntu has had a Unity 2D variant it was using as a fallback for a couple releases now, and in 12.10 it will be removed completely in favor of running Unity 3D on all systems using llvmpipe, which allows the CPU to handle the graphics processing if the GPU can't do it. Currently, neither GNOME Classic nor GNOME Shell come with a standard Ubuntu installation, though both can still be obtained through the Software Center post-install.
Answer: There is currently an unofficial community-led GNOME Shell remix of Ubuntu under development called Gnomebuntu, which aims to become an officially-recognized variant later on. You can follow developments on the project here. (There is an official website for it, but as of this writing all it has is a nice-looking placeholder.)
9/3/2012 UPDATE: The project is now called Ubuntu GNOME Remix after the original name was blocked by the GNOME project, and an initial alpha version is now available for download here.
Comment: I believe that it will be an important distribution in future.


Modbus ASCII messages delimiter

Question: I need to implement Modbus messages reception over UART. For RTU it's easy because UART on my uC has configurable idle receive line detection. However, for ASCII the task is tricky - the delimiter is based only on characters, then I'm not sure if timeout detection is enough - is it possible that two messages would come one just after another without any break? How is it implemented usually? This far my approach was to set timeout to 1.5 char and then use some counter for maximum 1s intercharacter delays and in every timeout event to check if the delimiter is there at the last 2 bytes of receive buffer.
Unfortunately, it's late to change the uC.
Comment: In the ASCII mode, the frame starts and ends with specific characters. Surely the Zynq which is a super fast ARM with programmable logic can do such a simple task? And the time between messages is mandated by the specs. Do you need to receive anything outside the specs?
Comment: Which MCU you are using and how are you receiving the data? Just to be sure, your MCU needs to be the ModBUS controller or the device? Why not receive the data so that you know how much data there should be and if it has been received properly?
Comment: Zynq 7000, should be able to be both master and slave. I'm receiving RTU data by waiting for rx idle line timeout configured to 4 character times.
The key is that incoming message length is not known in advance.
Answer: ASCII Modbus is delimited with <code>:</code> for start-of-frame and CRLF for end-of-frame. There's no need to do idle time detection at all.
In fact, the whole point of ASCII Modbus was to make it easy to receive on MCUs where idle time detection was a hassle.
Your MCU is so powerful that dealing with any Modbus format will not be a slightest problem.
Comment: @asiemasz Then don't do it like that. Doesn't the MCU support DMA? And what does "fast" even mean?
Comment: Yes, but it's not the only MCU task and I guess that causing interrupts every single byte on a fast baudrate to check for delimiters would not be good for performance.

Modbus ASCII messages delimiter


Creating radii around points, analyzing raster & vector data within those radii, QGIS 3.10

Question: I have a handful (literally, like 20) points that I need to create three radii around— 200m, 1000m, 2000m— so that I can extract raster (land cover within the radii) and vector (road length within the radii) data from those.
Does anyone have any idea how I might create those radii and perform that analysis? Seems like a simple enough task, but I'm figuring this all out on my own.
Using QGIS 3.10!
Comment: try looking at some of the many buffer analysis questions on here
Comment: Welcome to GIS SE! We're a little different from other sites; this isn't a discussion forum but a Q&A site. Your questions should as much as possible describe not just what you want to do, but precisely what you have tried and where you are stuck trying that. Please check out our short [tour] for more about how the site works.
Answer: Conceptually for each of the three distances you want to Buffer the points, and then use these buffers to Clip the land cover and road data. Specifically use the Raster Extraction tool to clip the raster landcover data, and Clip Vector by Mask Layer for the road data. In both cases your buffer will be your mask or clipping extent layer, so you'll need to run all the steps once per buffer (radii) distance.
The QGIS "A Gentle Introduction to GIS" page on buffering and the QGIS Processing Guide's page on Clipping and merging raster layers give some examples that could be helpful to understand the underlying concepts.


2 PVC Pipes running from unit to basement

Question: I have two 2" PVC pipes running from outside (AC unit) to the inside set up (furnace?). I need to cut these pipes and re run them since they are blocking the water heater which I need to take out. I wasnt sure what they did so didnt want to cut them yet. Is there water in them? Do I just turn off the unit first? When replacing do I use just regular PVC pipe and glue or is the some flex pipe solution? Any help would be great. I added some photos.
Comment: Not an expert, but pretty sure these are air intake and exhaust for the furnace, especially since they run outside.
Comment: Yes, direct vent intake/exhaust, judging by the connections shown in second photo. If so, one is exhaust fumes; you do(n't want that leaking and definitely don't want it open while furnace is running.
Comment: Yes, the outside makes it very clear. Make sure the furnace is off and cut them out as needed. I'd then replace with the same (looks like ABS). Reroute as needed.
Comment: @Ecnerwal sorry I am not sure the technical terms since I dont do HVAC. The pipes run from the outside unit (air conditioner) to the inside unit (furnace?).
Comment: which pipes are you referring to? I see condensate drain (white), heating loop, gas, ... and maybe direct-vent intake and exhaust. Plus water plumbing.
Comment: @keshlam the two 2" black pipes running down in front of the water heater then into the furnace
Comment: Yea, I can't think of any reason for those in an AC unit--aside from a condensate drain, but that'd be a drain--not a pipe going up. I think Darth is correct that they are air intake/exhaust for a high-efficiency vented furnace. If the furnace is off, you should be able to cut those out.
Comment: The best way to figure this out, though, is to show us a photo of these pipes on the OUTSIDE of the house.
Comment: @DA01 I think that is correct. I added a photo of outside. If this is just exhaust can I use a flex type pipe?
Comment: That's not PVC, it's acrylonitrile butadiene styrene (ABS) pipe
Answer: OK. These  have nothing to do with and no connection to the AC compressor, which makes a lot more sense than the original question with no outside picture.
Flex pipe is probably not an option - if it IS an option it needs to be a type specifically approved by the furnace manufacturer.
While direct vent exhaust is relatively cool, so it can be run in plastic pipe, it is still quite deadly due to the carbon monoxide it contains, and you do not want to be casual about how it's handled, or you and your family won't wake up some day. It happens.
You might well plot out a different route for the pipes that is less inconvenient, but be sure it fits the manufacturer's requirements for the intake/vent system (or have it done, or checked, by your heating contractor.)
Comment: Thanks. Not sure why they blocked in the water heater, but I will just do hard lines again. To do this safley do I just turn off the AC and furnace before cutting them? Then just use the same PVC pipe and re glue them
Comment: @Packy Check the pipe carefully for printing- I think you'll find that DA01 is right and it's ABS, not PVC (different type of glue, and couplings) - actually, that can in fact be read in the first picture at full size.
Answer: Those are acrylonitrile butadiene styrene (ABS) pipes, and can indeed be replaced and/or rerouted.
When assembling the plumbing, you'll want to use fittings and cements designed for use with ABS pipe. You'll also have to refer to the manufacturer's installation instructions for proper length and limitations on the number of bends.
For reference, the pipe that enters higher on the unit is the intake. It brings in air from outside, to be used for combustion.  The lower pipe is the exhaust, which carries harmful combustion byproducts outside.
While you complete the work, you'll want to insure the unit does not run. The best way to do this, is to turn it off at the breaker.


Boot into windows directly (not windows boot manager)/Editing the windows BCD from linux?

Question: I was editing the boot entries in windows boot loader and deleted the windows entry by mistake, after the restart there seems to be no way to get into windows to add the entry back. ANY help is appreciated.
Answer: I hope you have found your answer by now. I know it's possible to fix it from a Linux distro, but I don't know how yet.
Here's what I do know: From Windows XP and forward, perhaps prior to XP, there is a restore feature in the CD or DVD in the Windows Installation disk. If your PC doesn't have a CD/DVD-ROM or you don't have a disc, you can use Microsoft's media creation tool with a USB drive.
Then run either the disk or the USB - make sure USB boot is enabled in BIOS/UEFI and that it has first priority. Then run the installer and then look carefully for "repair" or "repair tools". Windows 10 has an automated repair tool, but it doesn't always fix an issue. Hopefully you have backed up BCD files. If so, you can use those to repair Windows' boot configuration.


Can an ISP detect or log specific devices connected to ISP-provided home routers?

Question: Let's say I'm using a Dell Inspiron Laptop. Does my ISP have a log of this or can they detect what devices are connected to my router?
Answer: The Possibilities
If you are using a modem and router provided by your ISP, then they can potentially have full access to data about your connected devices.  This is because if you are using their device, then you don't really have a network of your own - your house is just an extension of their network.  Some ISPs may use off-the-shelf hardware, in which case they may not take advantage of their access to your home.  However, since they provided the hardware, they also have an opportunity to customize the firmware (the software running on the router) to do whatever they want.  The router certainly knows about all the devices connected to it, and it would be very easy for them to customize the device to send them data about what devices are connected and when.  It wouldn't surprise me if many companies do this for general data collection purposes or to look for violations of their terms of service.  In many jurisdictions (especially the US), I'm sure doing so would be completely legal. Whether or not any particular ISP is actually doing this is another question, and difficult for us to answer.
Regardless of whether or not An ISP tracks your devices through your router, they can still see all of your network traffic of course.  This means they can read any traffic that goes across in plain text (which primarily, but not exclusively, means HTTP).  If you use their DNS servers (which will be the case unless you change it yourself) then they can also tell what sites you visit, even if over HTTPS.  Lots of information about your devices can be gathered from your traffic, so they probably wouldn't have any trouble tracking connected devices exclusively through your HTTP traffic, as long as the devices are actively fetching data from the internet.
Actionable Steps
If you are concerned about the possibility, then the simplest solution is to use your own modem or router.  Some ISPs effectively require use of their modem (for instance, I'm still using the modem provided by my ISP because it is difficult to find modems compatible with their network).  Fortunately, using a different router is the important part.  If you plug your own router into their modem and connect your devices only to your router, then you will make it much harder for your ISP to keep track of which devices are connected.  After all, the only device they will directly "see" is your router.
Once you are using your own modem you can configure it to use a public DNS service (opendns or cloudflare for example).  There is a lot of information hiding in your DNS queries, so this is an important step for the privacy-conscious.
If you really want to hide info from them though you'll mainly want to setup a VPN service 24/7.  They must be properly configured to make sure you don't leak data though, so it helps to know what you're doing when setting one up.  Personally I don't think that step would be worth it for the average user, but that's a decision for each person to make on their own, especially given recent news coverage about regulatory changes (at least in the US) that may give ISPs more rights to sell the data they collect about you.
https://www.forbes.com/sites/thomasbrewster/2017/03/30/fcc-privacy-rules-how-isps-will-actually-sell-your-data/#5825ab6021d1
Comment: It's a netgear router with trash firmware...so I'm good,right? Lmao when I log into my router through my public IP or whatever, it shows only the MAC address.
Comment: @NRSJ lol! Some of the netgears actually have great support for open firmware.  It certainly varies by model number.  Of course I wouldn't go installing new firmware on their modem, but that makes it hard to guess.  They might be using generic netgears because they are cheap and easy to work with, and so they don't have to make modifications.  Or they may be using them because they are easy to modify.
Comment: I have a netgear r6300...pretty generic
Comment: @NRSJ I'm sounding mildly paranoid here but I don't actually worry too much about ISP tracking my internet usage anyway.  Personally, I try to approach the internet from the perspective of "Everything I do and say will be discoverable by someone who cares enough anyway", so I just assume I have no privacy (hence my actual name on my profile).  That may not work for everyone, but unless you are doing things illegally, ISPs tracking your internet probably won't have much practical downsides for you.  It's just kind of the cost of doing business.
Comment: I'm just curious on how data is collected by ISP's and the privacy
Comment: @NRSJ It looks like that model is supported by some open firmware systems.  If you're feeling crazy you could try installing your own firmware.  Of course, this probably violates your terms of service, and you'll have to pay for it if you brick it.  Doing that is a lot easier these days, but it's not as easy as installing an app on your phone.  Again, the easiest way to put some distance between you and your ISP is by using your own router.
Comment: @NRSJ that varies wildly from ISP to ISP.  Your best bet for getting answers to that question is by asking them through official channels and reading your terms of service.  Obviously if you call up tech support you aren't going to get much of an answer.  I'm sure there is a lot that they are legal required to disclose (depending on your jurisdiction), but I'm also sure that they will try hard not to disclose that information, to the fullest extent that they can legally get away with.
Comment: Whether or not you use the ISP's DNS, they will able to see the contents of your requests as they pass through their network.
Comment: @multithr3at3d Good point - at least until DNS over SSL takes off.
Answer: Yes they do,
Actually in some places they are even required by law to identify and maintain a continuous record of all your hardware MACs and access times for criminal prosecution.
Actually there are multiple protocols designed for this purpose, like TR-069.
https://en.wikipedia.org/wiki/TR-069
Answer: Yes your ISP can detect partially what devices you have plugged on your network. Here is a small list of basic techniques that they can use are:

Check the User-Agent field of your HTTP traffic, the easiest.
Check some of the TCP/IP fields in order to detect the operating system.

The effectiveness of them depends on the device and how secure have the communications with the outside world.
Comment: Check the tool p0f is great for OS detection at TCP/IP level (http://lcamtuf.coredump.cx/p0f3/)
Comment: Do they log what devices are connected to your network? Lets say i no longer have the device? Can they go somewhere and determine that at this point of time, he had this device. Kind of like an IP log assignment
Comment: Probably your ISP logs a lot of information, regarding of the devices connected, ask them
Comment: @camp0 I would be interested how you would detect the OS through TCP/IP packets
Answer: If you are truely paranoid, then yes, your ISP can detect and log any device connected to their router. They have full control over the router software, so they can install a spyware to upload them everything that the router could detect. At the simplest level, MAC address, and with little effort, the OS of the device, at a higher level, every shared disk or printer, and the router could even provide access to any shared disk.
Can reasonably such a spyware be installed by the ISP? Only my opinion, but I would think the risk very low and acceptable - but I have no atomic code on my devices...
It is as usual a matter of threat and acceptable risk level. If the most confidential data that is present on your devices are the messages you exchange with your lover(s), and the codes for your banking service, I would trust the ISP (after all, you chosed them, and confidential data should have an additional protection level). If you are hosting some top secret mission critical data, things are really different, and you should not trust the ISP provided router, and instead install a fully controled firewall between it and your internal private network.


Running Tor on usb flash drive

Question: I have downloaded Tor and put it on a usb flash drive. How do I run it without putting it in the apps folder on the computer?
Comment: Is your question answered? If not, edit and provide more detail. If so, mark the answer.
Answer: You unpack the bundle to your memory stick, and run the 'start tor browser' shortcut.
The bundle is 'portable' and should run from any directory as long as you have the proper access rights to it.

Running Tor on usb flash drive


Message upon leaving a Facebook group

Question: If I leave a Facebook group, does a notification appear in the group? (I'd like to leave a group, but don't want the other members to know)
Answer: No.
No one is notified when a user leaves a group in Facebook. Not even the admin.
They will know only if someone looks to make sure you are still there.
Answer: Everyone in the group is notified. There is a notification saying what member left. I know this because I belong to a group and have left many times..as soon as I do, I receive a call from one of the members asking why, and because when someone else leaves, I can see the notification.
Answer: There are Groups and then there are Group Chats.
According to the latest official documentation:

How do I leave a Facebook group?:  Members won't be notified if you leave.
Leave a group chat on Facebook:  The other people in the conversation will be notified that you left.
Answer: Although no one will be notified if you leave a public group, everyone in a (private) Message thread will see a line in the thread if you choose to leave it.
Answer: Actually everyone in the group is notified when a member leaves.  It days. "So and so left the group".
Comment: Your answer is wrong. No one get notification even not admin.

Message upon leaving a Facebook group


Why doesn't emacs store buffers internally as a tree (better random access, no line-number limitations)?

Question: In section 11.18 of the GNU Emacs Manual, it's mentioned that buffers with a large number of lines line-number-display-limit or with particularly long lines line-number-display-limit-width might experience slow performance with line number calculation and so line number calculation is disabled by default. It seems to me that using a tree-like structure you could get logarithmic-time insertion and random access if every subtree kept track of the number of elements in it. What advantage is there in doing things the way emacs does?
Comment: Do you have an implementation that clearly shows there is no advantage in doing things the way emacs now does?
Comment: The Elisp manual sections about buffers might help with this question (dunno) - node [Buffer Gap](http://www.gnu.org/software/emacs/manual/html_node/elisp/Buffer-Gap.html), for instance. If you don't get a helpful answer here, you might ask the mailing list `firstname.lastname@example.com`.
Comment: @EmacsUser Yi uses finger trees for its buffers. I don't know enough about emacs to experiment with ripping out the buffer data structure and replacing it with something else.
Comment: This is a fun question. One consideration is that a tree probably needs more memory allocation and certainly has worse locality of reference, than a "dumb" data structure like an array keeping a gap at point?
Comment: I made the title conform better to the content of the question, but I am not thrilled with it. My question is sort of open-ended and I am not sure what a good summary would be. Have people looked into replacing the buffer implementation?
Answer: Personally, I doubt the buffer implementation can be blamed for every performance problem people encounter with buffers.  My specific problem with it did involve long lines that were slowing down redisplay, a known issue with a multitude of reasons behind it, including Bidi rendering, excessive movement of point crossing the problematic line and less than ideal font-lock.  I did plan on implementing a cache for line operations just to find out that such a cache does already exist.  After upgrading to Emacs 24.5, the issue was gone for me in Python REPL buffers, simply because font-lock was only applied for the input line and no more in the output.
tl;dr: There is no silver bullet.  Don't believe this is just a technical problem.  Do your own research, profile if you know how (perf should be ideal, gdb could work as well) and share your insights.
References:

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15555
https://www.reddit.com/r/emacs/comments/3aprkn/linumrelative_slow/csetpji
How do I prevent extremely long lines making Emacs slow?
How to prevent slow-down when an inferior processes generates long lines?


Change device on google find my device?

Question: I just had one of my android phones stolen, thankfully it was just a backup burner phone, but I still used my google account on it. I though I should be able to either find or wipe it from google's "Find My device" android.com/find , however it does not let me change the device like I can if I'm on the web google play store. It only shows my main device. Is there any way to get this to switch to my other device?
Answer: If it doesn't show up on the app, it's probably because the person who stole it has done a factory-reset. If that is the case it will not show up on the web version too
I just checked using the app and devices associated with my account show up when if they are switched off
Comment: None of my other devices show on the site I mentioned. If you are talking about something other than android.com/find please specify.
Comment: Sorry, I think I misunderstood. I thought you were referring to this [Find my device](https://play.google.com/store/apps/details?id=com.google.android.apps.adm) app by Google. If you can't see it in the web version, factory reset is the most likely cause
Comment: Another possibility is that devices (other than the one stolen) were not used for a long time and hence don't show up. Log in those devices and they should show up

Change device on google find my device?


about the rotation of the earth and gravity, when all continents were merged

Question: A long time ago, I read that the gravity force isn't the same if you are near the Andes Mountains or if you are at Paris. So today I asked to myself if when all continents were one, if the difference of gravity wasn't bigger. If there was no perceptible effect on the faune, on the rotation of the earth, and the tides. Maybe even on the motion of the moon.
Answer: You are quite correct that the position of the tectonic plates does affect Earth's gravity. The most accurate measurements of this were made by NASA's GRACE satellites. The results are generally shown as a geoid, that is a deformed globe showing where gravity is high and where it's low:

Note the scale is exaggerated to highlight the differences. The scale in the picture goes from -50 to 50 milligals, and 1 gal is about 0.1% of the average acceleration due to gravity so the maximum difference from the average is only 0.005%.
You ask about the effect on the Moon's orbit, and indeed this sort of effect is exactly how the maps shown above were obtained. The two GRACE satellites measure their relative position very accurately. When one of the satellites passes over a high gravity area (like the Andes) it speeds up slightly and the distance between it and the other satellite changes slightly. Measuring these changes allows the gravity to be measured.
So when a single supercontinent such as Pangaea existed it would have affected the motion of orbiting bodies. However the effects are very small, and at the distance of the Moon they would be immeasurably small.
You ask about the effect on Earth's rotation, and here I'm out of my comfort zone and have to resort to Googling like everybody else. Yes, there obviously would be a small effect on the rotation because the Earth would be asymmetric. However my guess is that the effect would be small. Remember we are talking about very small changes. Googling something like plate tectonics earth rotation will find you lots of articles on the subject.
Comment: thx for this very good answer!
Answer: It depends what accuracy you want to say things are equal.  We often say $g=9.81 m/sec^2$ at the earth's surface and don't worry about it.  Altitude and latitude affect this at the $0.3\%$ level.  You can look at Wikipedia to start.  Continental crust versus ocean crust is lower, but noticeable.
Comment: Hi Ross, you aren't wrong but this isn't really an answer either.  For example, would an average value of $g$ be $9.81\: \mathrm{m/s^2}$ if all of the continents were in one place?  You don't address what the question is really asking.
Answer: Isostasy is an important geophysical concept needed to understand the relationship of gravity, mass distribution, and first-order topography of the earth. The elevation of the ocean basins is lower than the continents because oceanic crust is thinner and more dense than continental crust. The gravity anomaly over a mountain range is less than you might expect if you do not consider that the crust adjusts in response to buoyancy forces and adjusts elevation by flow in the earth's asthenosphere.


How can I mask my alignment with another?

Question: I am looking for a way to make people detect me as evil even though I am good, or people detect me as chaotic although I am lawful. I know there are ways to completely change a character's alignment[1][2], but that is not what I am looking for. I also do not want to be protected from spells like Nondetection. Is this possible? How?
Comment: Without spells? Back in 3,5 this was a DC 70 epic Bluff check.
Comment: I would take a spell if there is one. Could not find one yet though.
Answer: Aura Alteration spell
Aura Alteration can change your aligment aura, but will not make it show the diametrically opposed alignment (Good/Evil and Lawful/Chaotic). It has a day/level duration, though.
Vigilante class
The Vigilante class has a class ability called Dual Identity, which says your second identity's aligment has to be within one step of your actual aligment on each axis. So a Lawful Good character has a second identity that is either Lawful Good, Lawful Neutral, Neutral or Neutral Good.

A vigilante's two alignments cannot be more than one step from each other on a single alignment axis. For example, a vigilante with a lawful neutral social identity could have a vigilante identity that is lawful good, lawful neutral, lawful evil, neutral, neutral good, or neutral evil. If a vigilante is the target of an effect that would change his alignment, it changes both of his alignments to the new alignment.

(From Lawful Neutral to Neutral Good/Evil are actually two alignment steps, but since the wording on the ability is one step on each axis, that allows two total steps so long as the steps are on different alignment axes.)
But the Faceless Enforcer archetype learns an ability called Faceless Infiltrator, which allows you to assume a third identity that has to be within one step from either of your two identities.
Which means he can make a Good character appear as Evil, or a Chaotic character appear as Lawful, but he still cannot make a Lawful Good character appear as Chaotic Evil. He could make a Lawful Neutral character appear to be Chaotic Evil if his secret identity is Neutral Evil, or appear to be Chaotic Good if his secret identity is Neutral Good.
If you are a (True) Neutral vigilante, your secret identity could be of any alignment you want. If you take the archetype and has a Chaotic Neutral secret identity, you could create a fake identity as either Chaotic Good and Chaotic Evil (from your CN identity) or Neutral Good, Neutral Evil or Lawful Neutral (from your social identity) whenever you want, expanding even more your options.
Master Spy prestige class
A 2nd level Master Spy has the ability Mask Alignment, which allows her to fake her alignment as anything she wants, even become completely diametrically opposed of her own, so a Lawful Evil Master Spy could mask her aligment as Chaotic Good.
But this only affects detecting spells. Other spells based on aligment, such as Order's Wrath still affect her normally.
Comment: I edited the explanation under the Vigilante alignment bit: the ability is worded as one step *on each axis*, which allows two total steps, so long as each individual step is not on the same axis. That's not weird or needing errata, that's just how the ability works.
Comment: I know it doesnt count for clerics, but on the vigilante's class ability it is worded differently, and the second example i gave was actually extracted from the book.
Comment: Your calculation of what constitutes "one step away" in alignment is off, as diagonals do not count.  If someone is Lawful Good, then only three alignments are within one step = LG, LN, and NG.  Neutral (or "True Neutral" as it is more explicitly called) is not one step away.
Comment: From Lawful Neutral to Neutral Evil are actually two steps if you look at the table.
Comment: Okay, I'll just take your word on that then, I suppose.  You may want to clarify this in the answer, though, explaining how this terminology is different from the norm.


Transfer in Lisbon on the way to Boston

Question: I am traveling back to Boston from Paris, France, with a connecting flight in Lisbon, Portugal. Will I have to go through security or recheck my bags in Lisbon or just when I arrive in Boston?
Comment: What airline is it?
Comment: Assuming it's TAP Portugal and booked on a single ticket: you do not need to collect and recheck your bags. HOWEVER, signage in the airport is pretty bad and last time I accidentally walked out of the secure area while trying to get to my connection and I had to go through security again.
Comment: It is TAP Portugal and is a single ticket as well.  I am normally not a nervous traveler but I am traveling a portion of the trip alone.  My layover in Lisbon is only an hour and 20 minutes.  I'm hoping that will be plenty of time.  My flight is in and out of Terminal 1.  Is passport control located in that terminal?  Any advice would be greatly appreciated.
Comment: @Karen The Lisbon airport isn't all that large, so it should be enough time as long as there aren't significant delays. Passport control will be in that terminal, just check the TV monitors for the gate of your next flight and follow the signs. You'll go through passport control and then be in a special part of the airport just for non-Schengen international departures.
Answer: Assuming you have booked a single ticket, you will not have to go through security or recheck your bags in Lisbon. You will, however, go through Schengen exit immigration, where your passport will be stamped out of the Schengen area.
Comment: Of course the stamp bit assumes the OP is travelling on a non-EU passport (not unreasonably).
Comment: @origimbo I assumed since the OP said "back to Boston," though it is of course possible she's an EU national resident in the US. Either way, there will be passport control on the way out, with or without a stamp.
Answer: According to the Lisbon Airport website, whose connecting flight page can be found here, you do not need to go through a security checkpoint when you arrive in Lisbon, only passport control. The same website suggests contacting your airline to make sure your luggage is automatically sent to your final destination.
My hunch is that if you're on a full-service carrier (likely, TAP, I'm guessing), that they'll forward your baggage for you. That's been my experience in Schengen country to non-Schengen country connections elsewhere in Europe.

Transfer in Lisbon on the way to Boston


Are disabilities taken into consideration when establishing jurisdiction?

Question: If a person has a disability, whether physical or psychological, that would make traveling out of state/country a hardship for them, will the courts grant that person's state personal jurisdiction over the defendant?
Answer: No
In general, there is no need for a plaintiff, defendant, or witness to attend court in person if there is a legitimate impediment to them doing so.
Parties can be represented by their lawyers, testimony can be made by affidavit, cross-examination can be conducted over Zoom. During the recent pandemic, entire cases, both criminal and civil have been dealt with without anyone meeting up in person.
Comment: And, to continue the thought one more step. A court in another state that does have jurisdiction might very well have a legal obligation to accommodate the disabled litigant in the logistics of the case that is resolves, even though its jurisdiction over the case would be undisturbed, by, for example, some of the means that you suggest in your answer.
Answer: While agreeing with the points of Dale M, it is also true if you can argue that such remedies may not provide for a fair trial, generally, "ubi jus ibi remedium", or Civ. Code § 3523. "For every wrong there is a remedy" could be a last resort.
In the City and County of San Francisco, judges typically are willing to cross pretty much any rules of court and potentially other laws to accord with the above maxim when it comes to vulnerable populations, e.g. people with disabilities.
Civ. Code § 3520 and § 3521 may also play a role in assuming jurisdiction if one would otherwise supposed to be assumed jurisdiction over.


Save image with watir-webdriver

Question: How could i save image, which is loaded via watir-webdriver? All manuals and examples show only fetching src of image, and using open-uri saving it. But i need to save that image, which was generated when my page was loaded. How can i do this?
Could i use watir, and watir-webdriver at the same time? For example:
require 'watir-webdriver'
require 'watir'
@driver = Watir::Browser.new :firefox
@driver.goto (@base_url)
@img = @driver.image(id: 'CaptchaImage').save("2131.png")

How can i do something like this? Or else how to get it from cache?
Could anybody help me with it?
Comment: Are you by chance trying to write a bot that attempts to get around a Captcha?
Comment: @AbeHeward yes, but this only for testing purpouses)
Comment: @AbeHeward so what do you think?
Comment: I think most programmers are going to have a problem helping people with techniques to bypass captchas.
Comment: @AbeHeward bypass is bad) i need only for testing on overload our service... maybe watir is bad idea
Answer: OpenURI will help you ..
require "watir-webdriver"
require "open-uri"

b = Watir::Browser.new :chrome
b.goto "http://stackoverflow.com/"

File.open("target_file.jpg", 'wb') do |f|
 f.write open(b.img(:class, "sponsor-tag-img").src).read
end

Hope you are not doing anything bad.. :)
Please let me know if it helped.
Comment: it help with image, but not with my captcha with depends on cookie) but this is not your problem)
Comment: yeah, try tesseract-ocr :)
Answer: require 'watir-webdriver'

And if you're doing it frequently, you can extend Watir's Image class with:
Watir::Image.class_eval do

    def save path_to_new_file
          #so that src can be opened without raising:
          #Errno::ENOENT: No such file or directory @ rb_sysopen
        require 'open-uri'

        open(path_to_new_file, 'wb') do |file|
          file << open(src).read
        end
    end

end

so it can be used as follows:
browser = Watir::Browser.start 'google.com'
image = browser.img
image.save 'our_images/hi.png'

Answer: According to the watir-webdriver documentation, there is no Image#save method because it hasn't been implemented.
On the other hand, watir-classic does have a Image#save method.  This is the example from the rdoc:
browser.image.save("c:/foo/bar.jpg")

Comment: but watir-classic doesn't support chrome ff etc
Comment: Well, I can't refute that.  Beyond a watir-classic solution, you could look into [net/http](http://ruby-doc.org/stdlib-2.0.0/libdoc/net/http/rdoc/Net/HTTP.html) or [mechanize](http://mechanize.rubyforge.org/), which has methods to access images in the [`Page`](http://mechanize.rubyforge.org/Mechanize/Page.html) class.
Answer: This turned out to be a lil harder than it should be, but I needed to accomplish this since an image was only accessible when a valid session cookie is set. This is how I finally managed to accomplish this:
1. Install watir-extentions-element-screenshot
https://github.com/ansoni/watir-extensions-element-screenshot
You probably want to do gem install watir-extensions-element-screenshot.
2. Resize the browser window
This also works with headless phantomJS. After you initialize the browser, set the window size to something rather big to prevent a bug from happening when the image is larger than the browser window.
browser = Watir::Browser.new :phantomjs
browser.window.resize_to(1900, 1080)

3. Get the image element and screenshot it
In my case, the entire site is an image. Luckily, browser.html does show that the image is still encapsulated in an  tag, so we can access the image (in this example all images on the page) like so:
browser.elements( :tag_name => "img" ).each do |x|
    x.screenshot("file_name.png")
end

This will save the image to file_name.png. It's not the exact same file, rather a screenshot of it. But as far as image download is concerned, this is a perfect solution for me and hopefully for others too!

Save image with watir-webdriver


What effect does tropopause entry have on the FMGC?

Question: In my company it's a procedure to enter the highest tropopause level into the INIT A page. Could someone please explain the effect it has.
Answer: It adjusts the FMGC temperature model to account for non-standard temperature. This will have the effect of improving performance predictions by having a more accurate temperature model.
The FMGC uses a temperature model based on the International Standard Atmosphere (ISA). The ISA is based on a sea-level temperature of 15 deg C. In the model, temperature decreases with altitude at a rate of 1.98 deg C/1000 feet up to the tropopause. Above the Tropopause, the temperature is a constant -56.5 deg C.
Updating the tropopause as well as entering the cruise altitude/temperature will adjust the temperature model closer to actual and thus improve predictions. Not entering either value will result in predictions using the ISA model which will reduce the accuracy of predictions (except in the off chance the actual weather matches the ISA.)
Comment: Therefore the best flight level may change too or, seen otherwise, this may allow (or prevent) to request a higher FL to reduce turbulence.


Express on Node - what data store?

Question: I'm doing my first project in node/express.
I'm looking to implement a data store and noticed that express is using redis as a session store. Does this mean that express installs redis by default? The reason I ask is that I pondering whether to install mongodb but if redis is already there to use, I'll go with that.
New to node and express so any advice much appreciated.
Answer: Last time I checked, express used a built-in in-memory data store by default and connect-redis was a separate package.
express installs neither redis (the database executable) nor node-redis (redis API binding for node) nor connect-redis (session store for connect and express that uses redis).
redis is a very simple database compared to mongodb. Mongodb is a full document-oriented database and redis is just an in-memory key-value store.
Also, express relies on connect for most stuff including session management, and sessions are in fact provided by connect.
Answer:
The reason I ask is that I pondering whether to install mongodb but if
  redis is already there to use, I'll go with that.

Question you should rather ask is if redis would be the right data store for your stuff. Redis doesn't support for example querying which might be crucial for you and your data retrieval, so if that's one of your requirements you should go with mongodb.
Comment: Good point : I just need somewhere to throw some key value pairs for now. - thanks.

Express on Node - what data store?


Do I need rim joist for this tree house platform? What will happen if I leave them off?

Question: Because the angle is odd and the trees are not parallel my idea was to put everything up as is, tack the decking on and then strike a line on the joists to cut them exactly so they're even. You can see in this picture that everything is up and all I have left is to cut the joists to the right size, but, after having it like this for a few days we like the exposed looks of the joists and don't really want to add a rim joist. Is this a problem for cutting them to length but not adding a rim joists? I know it's there to provide lateral support but for this application do you think it's necessary? What could happen if I leave it off?
Comment: FWIW, I did a similar, though smaller and lower tree house that I closed off the ends with a standard rim joist treatment.
Answer:
Do you have to?

No.

What will happen if you don't?

The unsupported ends of your joists will:

sag
twist

The decking on the left of the single tree (from the angle of the picture you provided) will become uneven, making tripping hazards for the occupants up top. You'll also end up needing to replace those deck boards more frequently, since not only will they want to do some warping and cracking of their own (it's wood, that's what it does), but they'll be forced into even more warping by the joists moving underneath them.
An additional consideration - without the rim joist, what are you going to attach the railing to? Having the nice straight, even surface of the rim joist gives a good mating surface for screwing the railing posts to (with some serious sized structural screws, not decking screws (they're not designed for that kind of load), and especially not drywall screws). Without it, you're going to have to fabricate some pretty unique and beefy brackets to hold the railings to the ends of the joists. You'll probably have to cut through that last deck board to attach them. Then, you'll get to watch the whole railing get ripped apart as the joists twist with age.
But, you don't have to.
Maybe OP had thought about this, but it just occurred to me: I'd put a rim joist at the far end, too, even though each joist is directly supported by the beam and attached to them with the hurricane clips (kudos for that!). Those metal clips will help prevent the bottoms from moving when the joists want to twist (if it twists away from the metal, a joist can pull itself off the nail, leaving the metal behind), but will leave the tops free to move. A rim joist on the far end will help prevent warping all the way along the ends of the joists.
Comment: Indeed, @SteveSh. But, as the joists twist, they're going to take the posts with them, racking the railing. The railing will provide _some_ resistance to warping, but I'm not sure it can be counted on the way a rim joist would.
Comment: He could attach the posts for the railing directly to the floor joist.
Answer: yes you should use them
As you stated they are a part of the lateral system and the answer about that is no you don't need the rim joists here for that reason.
However, the rim joists serve other purposes. For one, they are also part of your gravity system. Look at the picture you posted an ask yourself, what stops all the joists from rolling over together like a connected string of dominoes? Yes, you do have the blocking in the middle (kudos! because that is serving the same purpose here, like a rim joist in mid span) but remember that wood is very ductile and the support is localized. That is why we use blocking at 8' oc maximum. I do note that loads are a big factor and this is more important if there are walls, roof and maybe more levels bearing on the end of the joists (building edge) and here that won't be the case. However, the roll over can still happen, slowly over time...
Other purposes for the rim joist is to provide overall integrity, alternate load paths and so on. To attach railings, and so on
Answer: I see you are using "Dry" lumber (rather than "Green" lumber) so drying out and twisting probably won't be a problem.
However, standard construction practices would require a rim joist. If you follow the Building Code, the Code says, "Joists shall be supported laterally at the ends of joists by blocking, rim joists, etc. to prevent rotation. (See ICC R502.7) However, this requirement is under the general heading: "Lateral restraint at supports". Key phrase here is "at supports".
In addition, the Code requires bridging or blocking at 8' on center when the size of joists exceed 2x12's. (See ICC R502.7.1) Your framing doesn't "exceed" 2x12's, but it does eliminate lateral rotation of the joists.
All these Code requirements are based on standard construction, including design load of 40 lbs. per square foot. I doubt you'll have that unless you add furniture, etc.


How to find the standard deviations of lattice parameters after Rietveld refinement with GSASII?

Question: I am trying to learn how to use GSASII. It is different from GSAS/EXPGUI, so I feel hard to find some information from GSASII interface. I want to find what are the values for the standard deviations of lattice parameters after Rietveld refinement. How can I check it?
Answer: I assume you are looking for the values of "estimated standard deviation, e.s.d." (also called standard uncertainty, s.u.).
You may find the values by exporting the result into a cif file. Click Export > Entire project as > Full CIF


Can I connect 4 wire and 2 wire RS485 devices on the same network?

Question: If so, how? I have 4 wire and 2 wire devices I would like to connect on the same data line. I know you can convert 4 wire to 2 wire easily at the master, but is it possible farther down the line, say after a string of 4 wire devices?
Answer: 4 wire device provide full duplex communication and 2 wire half duplex communication. It depends what kind of transceivers you are using and what communication you would like to have (half or full duplex).
It is possible to use 4 wire transceiver on a two wire bus.
With more information in your question you would get much better answer.


How do I update my Autodesk Import/Export Plugin?

Question: I'm having trouble importing FBX files from Daz with morphs, and a friend who is using an older version of Blender (2.78) actually has a newer version of the Autodesk Import/Export Plugin (and in the Blender docs I see there is a newer version still -- I'm using 3.1.17).  How do I get a newer version?  I've searched the web everywhere, but don't see any way to download this.  Do I just reinstall Blender and assume the newest plugins will be there?
Comment: For importing daz characters you may be better off using http://diffeomorphic.blogspot.com/p/daz-importer.html. It takes a bit more effort to setup but gives much better results.
Answer: The fbx import/export addon is one that ships with blender, newer blender releases will include a newer version of this plugin.
When you say you are using 3.1.17, I think of two possibilities, either you are reading the version wrong or you have a non-official version of the plugin installed. Blender 2.79 includes v3.7.17 of the fbx addon. In this commit made Oct/2014 the version of the fbx addon went from 3.1.0 to 3.2.0 and that 3.2.0 version of the addon was part of blender 2.73.
In your preferences, find the fbx addon details and you can see the version as well as the path to the addon file. If the path does not match the installation location of your copy of blender it will most likely be your settings folder. If this does show a version of 3.1.17 and it is not part of your blender install, find and delete that addons file/s.

If you have somehow managed to get an old version of the addon to replace the official installed addon you need to re-install blender and ensure that the correct addon files gets installed.
If blender 2.78 which included v3.7.7 of the fbx addon is able to import files that the newer version doesn't, you should report that as a bug explaining that the older version handles specific files better.
Being open source, all the files used to create blender are publicly available, you can find and download any or all of them. The fbx addon can be found in blenders addon repository which is now at v3.10.0, this is expected to work with blender 2.79 and may or may not work fully with older blender versions.


Why the mobilities of holes and electrons are not identical in an intrinsic material?

Question: In an intrinsic material, the lifetime $\tau$ of electrons and holes is the same, so in the equation for mobility,
$$\mu = \frac{e\tau}{m^*}$$
the only difference between mobility of electrons an holes is their effective mass, $m^*$.
But why would this mass be different if it represents the same phenomena?
Answer: Even in an intrinsic material, $\tau$ is different for electrons and holes.  This is because in the equation for $\mu$, the value of $\tau$ is not lifetime but rather the average time between scattering events.  Since holes aren't an actual particle, the movement of holes is really the movement of electrons in the valence band. Because there are many more electrons in the valence band than in the conduction band, electrons in the valence band scatter much with other electrons than electrons in the conduction band do. Therefore, $\tau$ for holes is smaller than tau for electrons, making the mobility of holes less than that of electrons in most (if not all) semiconductors.
As for effective mass, holes and electrons exist in different energy bands.  Since different bands have different E vs. k(momentum) relationship, the effective mass in different bands is different. The E vs. k relationship is due to quantum mechanical effects for which there is not an easy physical explanation.
Answer: The effective masses are different because they are on different bands with different curvatures.