Proof of the Model Universe Theorem: Proving the invalidity arguments in quantifier logic

Question: I am studying how to prove an argument in quantifier logic is invalid. The textbook I am using by Virginia Klenk claims that you can use a Model Universe that contains a finite number of objects to substitute in to the propositional functions. The book claims: "Where n is the number of different predicate letters in an argument form, the largest domain you need to test is one with $2^n$ individuals." Can someone explain or refer me to a proof for why this is so?
Comment: I am guessing that all the predicates involved are monadic (one place), otherwise this is false, as arithmetic shows. If there are n monadic predicates and each can be assigned T/F there are 2^n possible assignments, and the truth value of the formula depends only on that. With 2^n individuals in the domain every possible assignment can be made to be satisfied by an individual.
Comment: @Conifold, what example from arithmetic would show that this is not case for anything other than monadic predicates?
Comment: "Every element has a successor" with a dyadic successor predicate from arithmetic is unsatisfiable on any finite domain.
Answer: Consider an open formula F(x). In case that the variable x is bound to an element of the domain of discourse, say z, it becomes a closed formula F(z). We may treat a closed formula as a proposition of propositional calculus. For the semantic values of propositions, we assign the logical predicates truth and falsity; in this case, the question is whether any element of the domain satisfies a predicate or not.
When we have more than one predicate, F, G, H, ..., we have to consider all their possibilities just as in a truth-table of propositional calculus; however, we add a column for the elements, for we indicate each possibility by an element (recall we talk about satisfaction state of each predicate in the context of others). The rightmost column is to indicate a compound of them. I give an example below. In order to emphasise that we talk about satisfaction of an open formula, instead of truth values directly, I've used tick and cross marks.
By the arithmetic of the table, we know that for n predicates, we need 2^n rows to exhaust all the possibilities. Hence, any additional row (indicated by an element other than listed) would repeat one of the rows.


Monero GUI wallet not syncing

Question: I am running windows 10 on a surface pro 4. I have 8506 blocks left and counting up. It is the newest version of the GUI. Is there a way a way I can sync up through a different localhost maybe? I am still a noob so please explain like I am a 5 year old. Thanks
Answer: I think you mean connecting to a remote node. Syncing monero sometimes can be slow for some users so just keep it running and it should synchronize and may take days.
Edit: To give you an idea, today, I just tried to synchronized starting at 98% and took me 3 hours. I'm using an SSD which is faster.
However, you can connect  to a remote node if you are really having problems. To connect to a remote node follow this guide How can I use Monero without syncing the blockchain?.

Monero GUI wallet not syncing


Can slimes spawn on glass?

Question: Can slime spawn on glass? My idea is to have a fully transparent slime farm (not automatic) so I can see the slime flapping around.
Answer: No, slimes follow spawning mechanics of regular mobs, except they can spawn with a higher light level in slime chunks. Regular mobs won't spawn on glass, or stained glass, so slimes will not either.
Comment: I once experimented this hard way. We found slime chunk and wanted to do big farm , so we made glass floors so we can see on which floor the slime spawned...and yes, it was epic fail, no slime spawned ever......but slime chunks are irrelevant since slimes spawn regularly in swamps now.
Comment: @AntoineHejlík slime chunks are still highly relevant for farms. Since they ignore the light level in the slime chunks, you can get exclusively slimes spawning there.
Comment: I'm doing it 1. for fun and 2. for convenience to have slime near my base when I need some more slimeballs.
Comment: Actually, the requirement for a solid surface and space requirements are just about the only spawning rules for hostile mobs that slimes *do* follow. The rules are similar in swamps, but there's a y-level limit (51-69) and strange failure chances and moon-phase relations. In slime chunks, they do their own thing altogether.

Can slimes spawn on glass?


Does Salesforce Support SAML Artifact Resolution Profile

Question: I am using Salesforce as both the IdP and the SP. So, to be more secure I would prefer to use the SAML Artifact Resolution Profile instead of the Web Browser SSO Profile.  Since I cannot find any documentation that describes how to implement the Artifact Resolution Profile in Salesforce, I am believing that Salesforce does not support it.  If you know differently, please post a link to the implementation document.
Comment: Out of curiosity, what part of the spec makes you think that artifact is more secure?
Answer: Salesforce only supports two types of SAML 2.0 Bindings currently:

HTTP Redirect (GET) Binding
HTTP POST Binding

It is configured within Salesforce under:
Setup > Security Controls > Single Sign-on Settings > Service Provider Initiated Request Binding

Partially related but probably not helpful in this instance, ExactTarget (Salesforce Marketing Cloud) supports Artifact binding for SAML 2.0. Documentation: ExactTarget SSO


What is the triangulation angle?

Question: I start to work in the field of computer vision and read a paper in which the author states "When suitable correspondences between salient image structures have been established, the 3D uncerntainty of these structures mainly depends on the triangulation angle between the oberservations and the 3D structures". So what is the triangulation angle? In the wikipedia article on triangulation (http://en.wikipedia.org/wiki/Triangulation_%28computer_vision%29) there is a really nice pictures that explains the triangulation but which angle in this picture is the trinagulation angle?
Answer: The angle between the projections of the target point, along the host surfaces, is technically called Triangulation Angle.

What is the triangulation angle?


Is it possible to deduce the Archimedes' law of the lever using only the laws of conservation of the physics?

Question: Is it possible to deduce the Archimedes' law of the lever using only the laws of conservation of the classical mechanics? I never saw (which is strange), but I think that it's possible.
Answer: To be clear, let me quote the most general part of the law

Two magnitudes, whether commensurable or incommensurable, balance at distances reciprocally proportional to the magnitudes.

In other words, masses $A$ and $B$ balance if
$$
m_A x_A = m_B x_B
\tag{1}
$$
where $m$ is the mass and $x$ the distance to the pivot.
You could prove it via conservation of angular momentum about the pivot of the lever. Multiplying $(1)$ by $g$, we see that the torque about the pivot is $0$, hence there is no change in angular momentum; the balance beam remains at rest.
You could also prove it using conservation of energy. If we let mass $A$ drop by a small distance $y_A$ and $B$ rise by $y_B$, we have the relation
$$
\frac{x_A}{y_A} = \frac{x_B}{y_B}
$$
combining it with $(1)$, we see that there is no change in total gravitational potential energy $m_Agy_A - m_Bgy_B$, hence it is not energetically favourable for the lever to tilt either way.
Answer: In general, conservation laws are the most fundamental laws of physics, and all of classical mechanics can be derived from them. In particular, Newton's laws can be derived from conservation of energy and momentum.
For the law of the lever, you can derive it from conservation of energy for the case where the forces at the ends are weights that have some potential energy. Once the law is found in this case, it can be applied to all other cases, since the equilibrium of the lever is independent of the types of forces applied to it.


Where is the [TestMethod] Attribute in TypeMock?

Question: Ok, dumb question. I'm trying to set up my first TypeMock demo project in VS2005 but it doesn't recognize the [TestMethod] attribute. I've included both the TypeMock and TypeMock.ArrangeActAssert assemblies and I'm referencing them with "using" statements. Even intellisense can't find the attribute. What am I doing wrong here?
Answer: [TestMethod] is from the Visual Studio unit testing 'framework'.
The following code shows basically how to use the attribute:
    using Microsoft.VisualStudio.TestTools.UnitTesting;

[TestClass]
public class MyTests
{
    [TestMethod]
    public void MyFirstTest()
    {
        Assert.AreEqual(1, 1);
    }
}

If you're using NUnit or another framework, the attributes are possibily different.
Answer: Which unit testing framework are you using? TestMethod sounds like the Visual Studio test system, while the NUnit counterpart is called Test.
Answer: I'm guessing that the TestMethodAttribute comes from MSTest, not TypeMock.
So you should add a reference to Microsoft.VisualStudio.QualityTools.UnitTestFramework
Edit:
This is the namespace where the attribute is defined:
Microsoft.VisualStudio.TestTools.UnitTesting;
Answer: [TestMethod] comes from the MSTest library not from the TypeMock framework
Comment: Ah, now I understand. I was of the impression that TypeMock functioned as a complete mock/unit test framework on its own. Thanks!
Answer: Assuming you're using MSTest, you must include [TestClass()] for the class and [TestMethod()] for the tests (don't know if parenthesis are needed).
TypeMock is a mocking framework, so you should worry first for what testing framework you're using.


Do long distance business jets have a crew resting area?

Question: I am asking this question out of curiosity. Do they have separate cabin area for themselves?
Answer: Yes.  Gulfstream, FalconJet and Bombardier all offer a small crew rest space in their large cabin business jets, depending on the cabin configuration.  This isn't similar to those found on airliners, but it does feature a normal sized and reclining seat with seatbelts, a small table, lighting, emergency oxygen and a divider for privacy from the other passengers.
Answer: The interior configuration is the choice of the operator and for most business jets is done at a separate completion center (although Bombardier does Global interiors in-house) where the interior is certified under an STC. The airplane will leave the factory "green" (no interior or paint) to go to a completion center of the purchaser's choosing.
The owner can choose to put in a crew rest area and may even include a sleeping bunk.  It'll depend on the owner's mission profile, and how that profile affects the complicated duty period regulations the operator is subjected to. They may just put in a partitioned area with a seat and amenities, or may include a full size sleeping bunk if a relief pilot is required to be on board to meet rest period regulations.
Answer: Crew rest area or compartment is a separate area of an airplane which may not be accessible to passengers. Depending on the class1 of the airplane, crew may have a rest area with isolated resting places, or a flat seat separated by a curtain or a seat which can recline and has foot support.
In the US, FAA has detailed about rest areas in 14 CFR Part 117. Accompanied by the advisory circular AC-117, the classes are:

Class 1 Rest Facility Means a bunk or other surface that allows for a flat sleeping position and is located separate from both the
flight deck and passenger cabin in an area that is
temperature-controlled, allows the flight crew member to control
light, and provides isolation from noise and disturbance.
Class 2 Rest Facility Means a seat in an aircraft cabin that allows for a flat or near flat sleeping position; is separated from
passengers by a minimum of a curtain to provide darkness and some
sound mitigation; and is reasonably free from disturbance by
passengers or flight crew members.
Class 3 Rest Facility Means a seat in an aircraft cabin or flight deck that reclines at least 40 degrees and provides leg and foot
support

The above circular also provides details about the dimensions of each class and the facilities which are required.

1: Class of an airplane depends on the number of crew and the duration of the flight.
Comment: Not sure that anything in Part 117 applies to biz jets? It certainly governs Part 121 operations, but most biz jets are Part 91 operations, or 135 if they're chartered. Does Part 117 apply to those?


Paired sample t-test

Question: A colleague has administered a questionnaire that asked respondents to provide both before and after values and has used the paired sample t-test to check for effect of the intervention on the dependent variable.  Is this appropriate? I was of the opinion that there must be two observations that must be performed before and after the intervention. Please advise
Answer: Judging from the little information given, the procedure is correct. You have got two metric variables that stem from identical individuals. This alone makes them paired samples that are not i.i.d. and should be investigated with a method for paired samples. The i.i.d. assumption is violated and that is all that matters. Whether one questionnaire was filled in before an intervention or resembles the memory of before the intervention has no influence on statistics.
That does not mean, that retrospective questionnaires are of the same scientific value as questionnaires quo ante, but that is a question of methodology, not of statistic test choice.
Comment: That is indeed the heart of the problem.
Comment: Some additional details: We are interested in finding out the effects of soil testing on maize production - among other crops. Respondents provided estimated maize production before + after soil testing. To this end, I believe you have answered my question that as long as two metric variables exist from identical individuals the IID assumption is violated and thus a method of paired sample applies.

Paired sample t-test


What is "gps on demand time injection"

Question: Android defineds a GPS device capability I couldn't find reference to
It's defined as GPS_CAPABILITY_ON_DEMAND_TIME in gps.h
The description in the comment explains:
GPS on demand time injection.
What does it mean ?
Answer: GPS_CAPABILITY_ON_DEMAND_TIME refers to the ability of the Android framework to trigger an injection of the current time into the GPS engine.  This is used as part of the assistance data to speed up time-to-first-fix.  Here's where the constant is used in the Android framework:
https://github.com/android/platform_frameworks_base/blob/master/services/core/java/com/android/server/location/GpsLocationProvider.java#L1625
You can see what happens in the handleInjectNtpTime() method (NTP = "Network Time Protocol"):
https://github.com/android/platform_frameworks_base/blob/master/services/core/java/com/android/server/location/GpsLocationProvider.java#L842
Apps can also trigger this via the LocationManager.sendExtraCommand("force_time_injection"); method - the app GPSTest has a button where you can trigger this time injection manually, if you want to hook up an Android device and trigger the call and see what happens (fully disclosure - GPSTest is my app).  On some devices you can see LogCat output fetching the NTP time.
Here's the code in GPSTest that triggers the call to inject NTP time:
https://github.com/barbeau/gpstest/blob/master/GPSTest/src/main/java/com/android/gpstest/GpsTestActivity.java#L173

What is "gps on demand time injection"


Design concept on land scape

Question: I would like to know the meaning of design concept  , the type of design concept, and ways on which design concept are applicable .
Comment: I;m afraid you need to refine your question - its too broad and not very clear at the moment. 'Design concept' just means an idea for a design, any idea. The type of the concept is not something that can be defined because you've not mentioned a particular design concept. As for how a design concept might be applicable, without knowing the specific circumstances and the design concept in place, its impossible to answer, other than to say a design might be based around concealing ugly features, or practical in origin,  or simply to create a particular look, i.e. cottage style.
Answer: In my experience, a design "concept" is a document that lists all the pertinent information that will be used as criteria when a design product (plan drawing) is created. First the concept will contain the instructions of the owner, e.g. "This will be a memorial to my husband. It will be a place where people can sit and reflect on his many achievements." It will also list all the stakeholders who have an interest: local authority, neighbours, corporate interests, contributors, and so on with their special viewpoint expressed. It will contain perhaps a SWOT analysis of strengths, weaknesses, opportunities and threats. Anything that has a bearing on why you are doing this thing.
It might be a long list of items; they will help establish who is to do the design, in what time frame, the budget, special requirements. It will be the source document that gives the reason why you plan to put a red oak tree right in the middle and several benches for example. Whenever someone questions why you decided to put some Hostas in one corner then you just refer to the concept where it says it is the family's favourite plant. The concept is the narrative on which the final product hangs.
Comment: intriguing description - I've been designing gardens for 30 years in the UK, and half the stuff in your definition has been neither necessary nor desirable, though may well apply to design concepts in other areas - interior design, product design and so on.
Answer: Design is the creation of anything by us humans.  There are rules that cross all subjects and then there are the inherent problems to be solved unique to  each subject. Design is a process to create something beginning with conceptualization then proceeding through a 'creative process' step by step that will bring a 'design' to light justified to become a design.
I am assuming this is about landscape design since you came to this site. Short story.  First year of my studies, we were given a project to design and give presentations. I remember someone mumbling about a creative process but I didn't get it. I always thought some people have a gift of creativity and others did not.
So I did this great project and great presentation and then my professors went into a meeting. The next day they called me in and sat me down and said, "You fooled us.  You did not do a creative process. You rationalized a project after the fact.  The creative process JUSTIFIES design concepts.  You were so good you were very bad.  We have decided that you now have a Directed Study to do. We want you to create a 'slide tape' presentation on the Creative Process". That is simply a class of one, me, to TEACH this process for 2 credits.  The effort was priceless.
I had to create a slide tape presentation (we only had the IBM 4341 in those days), those that created power point weren't even born yet!  So I sat down and outlined all the factors and how to organize my work according to this PROCESS I wasn't at all sure about much less, teach this process.
To make a long story short, the crux of this process is to list all the main problems.  For each problem one has to make themselves come up with 10 ways to solve that problem.  For each answer one needs to then come up with 10 ways to address each answer by thinking of all the problems that could arise.  And each one of those 10 problems  needs 10 answers to solve those problems.
Hey, sometimes, I'll allow 5 answers instead of 10.  It is a huge no no to 'jump' to the end product without going through this process. One makes their mind stay open by never jumping to the end product to imagine some end result or design... without going through this process that may take weeks.
When you have finished putting yourself through these 'hoops' of question and answers...a 'design' slowly emerges and you will know it is the perfect project or as close as one is able to get to perfect.  No one can or should just come up with a design without going through this process of making your mind jump through 'hoops', making oneself focus on each little problem, asking questions and having to come up with 5 or 10 solutions and then making oneself come up with 5 or 10 problems with each solution and then making oneself come up with 5 or 10 problems for each solution is simply using one's brain to its maximum potential.
The most incredible design takes shape.  One that is JUSTIFIABLE. A design that no one will be able to argue against very well at all.  Lots of designers who weren't taught this process jump to the final project with some Hollywood idea and then try to RATIONALIZE why those Hollywood ideas might work. Convince others of your innate design abilities and to sell your Hollywood idea. Great graphics and presentation skills can sell anything, even bad designs.
You'll be blown away by the final designs after going through this process. You have to understand construction, rules by the city/county for development, plants and soil of course, infrastructure such as irrigation, utilities, electricity, you'll have to get to know what your clients expect and how to educate them that part of their expectations are not going to happen and why.  The client DOES NOT KNOW BEST.  Other information you have to acquire; how many kids they'll have, what pets they want to care for, what they like in landscape and what they don't like in landscape; styles, what works now in their landscape and what does not.  Who will be maintaining the landscape, irrigation, lighting, coming up with costs and a final Master Plan complete with a page of construction details, a plant design, electrical design, irrigation system, lighting (powerful), specifications, perspectives of how the project will look, grading and drainage plan (critical)...not a small deal at all!
Once there is a signed contract, ha ha ha, that is when the real design begins.  As construction ensues, changes will happen (that wall is over the corner of the septic tank), and the entire design might change.  Listening to the subcontractors is again, critical; the rockery guys, the earth moving and grading guys, the nursery stock available, an ancient grave gets dug up!  Cad is nice but learn to do hand drawn plans, perspectives!  That is what sells, not Cad.  Cad is fun after a master plan has been approved.  Changes are so much easier than having to redraw by hand everything.  But hand drawing puts you INTO the project where Cad and the computer do nothing more than cut and paste.  Hand drawing puts clients in a safe frame of mind and allows them to become part of the design and they will pay more for stuff they can envision.
Landscape Architecture is one of the best subjects to learn as one is made to learn ALL sciences, construction practices, how to sell ideas, how to work with a clients through fruition of that project without 'breaking' up the marriage before the project is finished.  In fact, all of our clients became maintenance clients and constant little projects and constant big projects.  All the neighbors became clients.  I preferred residential over commercial.
I save BUDGET for the very last stages.  I pretend money is not a factor as I put myself through these 'hoops'.  When you get to where you see a design emerge it is very easy to scale down or even up to fit a budget.
Each project you do is unique has unique problems to be addressed.  Functional design is the only design.  Form follows function.  Beauty is in the functionality. Money does not at all make or break designs, ever.. Each project is fluid.  Things change every day, you will learn new information that you will have to address by 'jumping through hoops' again.  The more you know about every facet of the landscape, your client's needs, the more fantastic design.  Your conceptual plans are only to generate feedback from your clients.
Hand drawn plans are best for 'selling' or 'pitching' ideas.  CAD drawings look 'carved in stone' and that puts a client with his back against the wall and digging in his heels. The absolute best way to design is pull that client into the process.  I had one client, I shared this process, I would draw conceptual plans and then he would go redraw the plan.  He was very happy to be involved and the feedback was fantastic.  We went from a 20K budget to 110K.  An Italian Piazza.  In Washington in a nicer development but still a bit too much to recoup expenses when and if they sell their home. Incredible parties.  And this particular client was the budget manager for a huge firm.  His story starting at a 20K and ending up at 110K was a bit embarrassing for him at his parties.
The only way to be a fantastic designer is learn how to do this creative process and USE it every single time.  Your genius will be amplified every time you exercise your design abilities by making yourself jump through hoops.  Until you have actually gone through this creative process you will not quite understand. You just have to trust and jump through the hoops.  Pretty amazing to see what you are able to create! No, not just amazing, phenomenal.
They show  newbie Landscape Architects this slide tape presentation I made, 1978? to this day; 2 carousels of slides.  2 big screens.  I used cartoon type characters that looked like my class mates and professors.  That was a big hit.

Design concept on land scape


How to color symbols by data in MapInfo?

Question: In MapInfo 10.0, how can I quickly colorize point symbols according to a field in the data table, without creating a new map? My data is just longitude, latitude and time, and I'd like to colorize the points according to the time field. This seems really basic but I can't find any way to do it.
Answer: what i understand from your question is that you want to create points thematic,changes both symbol size and color.
you can do it as :
1.Map > Create Thematic Map
2.Select Point Ranges Default from template
3.Click Next and select a table and a field.
4.Select your Ranges...
The result will be sth. like this. you can more info here.
.

i hope it helps you...
Comment: I guess there's no easier way to do it? I'm debugging some code and it takes lots of clicks to create a new thematic map every time the data file changes.
Comment: I mean, can I make the symbol color depend on data in the current map, and for example quickly try colorizing it according to different fields, without creating a new map every time?
Answer: Assuming it is the time field specifically you are having trouble with, I would suggest following the instructions at http://reference.mapinfo.com/software/mapinfo_pro/english/10/MapInfoProfessionalUserGuide.pdf on page 175.
Specifically, you need to explicitly convert your data type to "Time/Date" in "Table Maintenance" and the text needs to be in the following format:

Date: yyyyMMdd
Time: HHmmssfff
DateTime: yyyyMMddHHmmssfff


How to keep a rigidbody on the ground going up/down a slope? (Unity 2D)

Question: I'm not sure if this is possible, but Im working a 2D project to has randomly generated loops (imagine a sin or cos graph). I have a 2D character (a quad for now). I want my character want to ski a long the slopes. The bottom surface always needs to be in contact with the terrain, unless it's a sudden slope change. Im trying to use to rigidbody for this, but when going down slopes the character just bounces and rolls down the hill. What can I fix this?
Comment: Possible duplicate of [How to achieve 2D ski movements similar to Alto Adventure?](http://gamedev.stackexchange.com/questions/122392/how-to-achieve-2d-ski-movements-similar-to-alto-adventure)
Comment: I'm not denying that they are similar, I have a lot of trouble phrasing my questions. In this question I was strictly asking about how to control Rigidbody physics down a slope. In the first question I was exploring the possibilities I had for 2d ski movements. Since I'm new to game development I thought there would be a few a standard solutions for tackling this problem. Anyways I have tweaked the questions for more clarity the 2 questions.
Answer: I'm not sure if I understood the problem right but maybe you can limit the Z rotation of the character to a certain angle so it can't tumble when you are going downhill. But if you also want your character to be able to flip in the air at certain heights for extra points or whatever your score system is, you can set the rotation limit only if the player is closer to the ground for a certain distance.
Answer: Changing the gravity scale of the game (under physics2d settings inspector) could be a solution, but I still won't suggest it, since the jumps based on physics will get affected by it. You could always increase the force applied when jumping, though.


Parler plus lentement vs parler moins vite

Question: I'm just beginning to learn French, and often I want to ask native speakers to speak more slowly. What is the most polite way to ask this? I'm especially wondering whether a request to "parler plus lentement" may be considered impolite and if "parler moins vite" may be considered more respectful.
Comment: I would say it shouldn't  make much difference and anyway not specific to French, it would surely be the same in your native language. Personally I find *plus lentement* better (you're not reproaching the person you are talking too of talking too fast, but express your need of it being slower), but again, that's not a language question. As long as you say it politely *Pourriez-vous parler un un moins vite s'il vous plait, j'ai du mal à suivre.*
Comment: *Excusez-moi, mais est-ce que je peux vous demander de parler plus lentement, s'il vous plait ?*
Answer: Both are perfectly fine.
The only thing I would change is adding "s'il vous plaît" at the end.
You can also write "s'il vous plait" without the circumflex accent on the last 'i'. It is correct too.
Parlez moins vite, s'il vous plaît.
Parlez plus lentement, s'il vous plaît.
Kind regards.
Answer: The level of politeness required would depend on the context but as you asked for the "most polite way", I would avoid both parlez plus lentement and parlez moins vite as they are kind of orders.
A more polite way would be to apologize and indirectly ask for a slower pace like in:

Excusez-moi. Est-ce que je peux vous demander de parler un peu plus lentement, s'il vous plaît ?

i.e.

Excuse me. May I ask you to speak a little bit slower, please?

An extra polite one would be:

[...] Est-ce que je peux me permettre de vous demander [...]


How do airliners with engines mounted on places other than wings suppress wing flutter?

Question: Assuming airliners typically have high aspect ratio flexible wings, how are wing flutter suppressed when engines are not available on forward-reaching pylons as weights?
Answer: Since flutter is a natural-frequency harmonics phenomenon, it's a matter of "tuning" the wing box structure with the required stiffness and damping to move its natural frequency range outside the range experienced with its C of G and torsional center offset and uncompensated for with engines on pylons.
It's a bit like with flight controls.  With manual ailerons, the aileron/wing system is flexible you could say, and needs mass balancing.  Like wing mounted engines.
With hydraulic controls, the connection between the aileron and wing is rigid outside of movement induced by the hydraulic actuator.  No mass balance required.  Like a wing box with no engines that has to be inherently stiffer than otherwise.
It's one reason wing mounted engines are more common than tail mounted.  Lets you make the wing box structure a little lighter.


osTicket not able to access folder in Mailbox

Question: I am using osTicket as ticket system on my site. Hope someone here will be able to help me out.
I was setting up an email in osTicket so that emails can be retrieved automatically. Fetching works properly but I am facing these issues:

Mail fetching:
a. Sometimes the fetching works and I can see the new ticket.
b. sometimes the email is deleted from mail box (as I have selected
   "Delete fetched emails") but no ticket is created.
c. Sometimes the ticket is created and I can see it in database but
it is not automatically assigned to anyone although a user is
selected for Auto-assign in HelpTopics.
I cannot setup "Move to" for fetched emails in Mail Account page. When I enter the folder name and click on save, it gives error "Invalid or unknown archive folder!" and " Invalid or unknown mail folder! >> Mailbox is empty" errors. I created the folder from Horde but for some reason osTicket is not able to access that folder i guess. This is when Protocol is POP.
If I select IMAP and click on save, I get:
Warning: imap_open() [function.imap-open]: Couldn't open stream {localhost:110/imap/novalidate-cert}INBOX in /home/admin/lifeemail.com/support/include/class.mailfetch.php on line 130 on top of the page and below in the settings table i get this in red: [CLOSED] IMAP connection broken (server response)

Point 2 is the main problem that is a headache. I tried getting help from Google and osTicket forum(its not very active) but I got nothing.
I am using 1.7 RC3.
Comment: I had the same problem, for the 3. IMAP port number was incorrect (993 on Hostgator if connection is SSL)
Answer: try to type the folder name this way:
INBOX.myfolder
should work!
Answer: Solved #2 for you, "When I enter the folder name and click on save, it gives error 'Invalid or unknown archive folder!' and 'Invalid or unknown mail folder! >> Mailbox is empty' errors."
I also could not enter the folder name into the "Move to folder" field. I solved it by clicking in the field, and keeping the mouse key held down while typing the name of the folder.


SKMaps - App Errors Uploading To iTunes Connect - Invalid Binary - Segment Alignment - Encryption

Question: I am trying to upload my app with SKMaps.framework to the App Store. App runs perfect on simulator and device.
But I get the below errors uploading build to iTunes Connect.

Dear developer,
We have discovered one or more issues with your recent delivery for
  "xxxx xxxx". To process your delivery, the following issues must be
  corrected:
Invalid Binary Architecture - iOS 3.0 introduced support for multiple
  binary architectures. If your binary is built for multiple
  architectures, your Info.plist must have a MinimumOSVersion key with a
  value of at least 3.0. Additionally, if your app is intended to
  support earlier iPhone and iPod touch models, your app must contain at
  least an armv6 binary; "thin" armv7-only binaries will not be accepted
  unless the armv7 required device capability is also present in the
  Info.plist UIRequiredDeviceCapabilities key or the MinimumOSVersion
  key has a value of 4.3 or higher.
Specifically, we found the following unsupported architectures in your
  binary:
x86_64 i386 For more information, see Technical Q&A QA1707 at:
  http://developer.apple.com/iphone/library/qa/qa2010/qa1707.html.
Invalid Segment Alignment - The app binary at 'xxxx
  xxxx.app/Frameworks/SKMaps.framework/SKMaps' does not have proper
  segment alignment. Try rebuilding the app with the latest Xcode
  version.
Invalid Encryption Info - The binary is invalid. The encryption info
  in the LC_ENCRYPTION_INFO load command is either missing or invalid,
  or the binary is already encrypted. This binary does not seem to have
  been built with Apple's linker.
Though you are not required to fix the following issues, we wanted to
  make you aware of them:
Non-PIE Binary - The executable 'Payload/xxxx
  xxxx.app/Frameworks/SKMaps.framework' is not a Position Independent
  Executable. Please ensure that your build settings are configured to
  create PIE executables. For more information, refer to Technical Q&A
  QA1788 - Building a Position Independent Executable
Once the required corrections have been made, you can then redeliver
  the corrected binary.
Regards,
The App Store team

Without this framework, my app is totally useless. The framework version is 3.0.1.
Answer: Just use the build without the simulator slice, this should solve you problem. You can find the latest build here: http://forum.skobbler.com/showthread.php/14602-3-0-3-release-candidate-builds?p=32322


Death by candle

Question: Many sources state that candles have been heavily used for light and timekeeping starting as early as 3000 BCE. Until electric lighting took over starting in the 19th century, candles and oil lamps were the the main source of artificial light. What I'm curious about is, how many deaths were historically attributed to candles and lamps either failing or being misused? Do we even have any evidence to say that it was a common problem? If not, is there any evidence to the contrary, that candles/lamps were indeed very safe?
Comment: The Great Chicago fire of 1871, which killed around 300, was popularly attributed to a knocked-over candle or lantern. That may not be true, but fires in cities have always been an endemic problem, and one would imagine untold amounts of them were started by careless use of a candle or lamp.
Comment: They say the same about the Great Fire of London (1666), though it is hard to determine exactly: most of London was gone. I suppose that most of the great fires which were so frequent in the old days can be attributed to candles and other lighting devices. Someone just falls asleep, and the candle falls on the floor...
Comment: The (retired) principal of my high school incinerated himself by falling asleep with a lit pipe in his mouth. Fire is a dangerous beast.
Comment: I'm going to suggest that any question tagged with "Ancient history", "Early medieval" and "early modern" is ipso facto too broad.  This question covers 5000 years of history.
Comment: Even given an era tag, this still remains too broad imo. OP should specify a region and a time period to narrow down the scope.
Answer: Candles where a fairly major fire hazard as it was difficult to shield them yet still get air. The flames were not large, people used to snuff them with their fingers. Also, as Matt Riddly has pointed out, an hour of light in IIRC 1792 took three hours of labor during the day for the average person. Not until the later 1800s, was it common for the middle class and lower to keep lights after sundown.
This was all before hard data collection so nobody really knows.
I do know that it is agreed that the major source of burns, at least in the past northen climes over the last few centuries has come from women's dresses being ignited by kitchen fires.
Lanterns, both whale oil and later kerosene were not not much of risk, even the glass ones. The active flames were contained and the vapor pressure of the oils was so low they were difficult to ignite and if the lamp broke, the fuel was almost certain to smoother the flame than ignite. The whole glass lamp being a Molotov cocktail is pure Hollywood.
Town gas lighting in urban areas appeared circa 1810, much earlier than most people imagine. So not in populated areas, niether candles nor laterns would likely be in use.

Death by candle


Is it possible to put special pieces on a chess.com custom board?

Question: I would really like to create custom positions with custom pieces (and maybe even variants) to play with my friends because we have always enjoyed playing custom variants. So for example a board with the camel instead of knights. Is there a way to do this on chess.com or an equivalent website?
Comment: Are these pieces your own imported in or already a part of the website?
Comment: @HarryIguana The required pieces are all ready inside chess.com, you can see them is some variants
Answer: Probably the most advanced diagram creator in the whole Internet is the Board Painter of Musketeer Chess. There are others, but none like this.
It has almost FOUR HUNDRED different fairy pieces for each colour (400 white and 400 hundred black), including not only an impressive zoological collection with every animal that could possibly be imagined, and with every strange object that might be thought of as a Fairy Chess piece, but also traditional pieces and special boards for Japanese Shogi, Chinese Xiangqi, Chinese Weiqi (also known as Go), and many other historical or regional Chess-like games for playing almost any variety of Chess ever invented.
The board can be made of any colours, not just black and white, and with an enormous number of rows and columns for those who, as it is my case, love playing in gigantic boards with legions of Chess men battling on them.
I have played Grand Triple Chess (a variety of 24 x 16 squares, totalling 384 squares) using this amazing diagramme creator. The game is now available in Evo Chess, but when it was not available, we used to play by the method of creating a diagramme for every move, converting the diagramme to an image, and sending the image to the opponent. It works perfectly well.
The Board Painter of Musketeer Chess is fairly complex, You can even mark specific squares and indicate moves with arrows and symbols of various forms and colours. Endless number of possibilities, but the Board Painter is not very easy to learn, which means that You will need an ample time for experimenting with it and learning how to use it correctly. Once You know its sophistication, You will have a truly impressive tool at Your disposal.
I know it in detail, therefore if You have questions, be kind to ask and with pleasure I shall help Your study. Because study You will need, do not expect to know how to use all of its incredible resources on the very first day.
A fine piece of on-line software, available here.
Comment: Welcome to [Chess.SE]! This looks a bit like an advertisement; if you are affiliated with this website, [you must explicitly state to](/help/promotion).


User defined domains

Question: how can I create a user defined domain?
E.g. user one will select for his shop the domain "shop1.example.com".
User two will select "shop2.example.com" etc.
How can I do this?I was thinking of Domain Access module but I am not sure which submodule to use.
thanks
Comment: do you have a dedicated server?
Comment: Not now,but I will(Amazon server)
Comment: Do you want the same db for all the sites?
Comment: Yes I have the same db for all sites
Answer: Drupal can handle multiple sites very well. In a raw way without any modules you can use the multisite features of drupal. This can be done by creating submodules under sites for each of the sites.
When it comes to modules there are couple of them that deals with subdomains and multiple sites.

Virtual Sites
This kind of automates the Multisite configuration for drupal. You can create additional domains and subdomains.
Subdomain
This one is mainly used to create a subdomain and place contents under that subdomains. For example all contents of a group can be placed under the groups subdomain.
Domain Access
Domain access is used in scenarios where you want to share contents between your domains and subdomains. You can assign contents specific to a domain or have the same content appear in multiple domains. Assign admins per domain etc. This is used for affiliates sites. A use case would be a main rental site with subdomains for each city.
Aegir
This is not a module. This is a complete hosting solution build for drupal. This is a hosting profile. You would install it on a dedicated or virtual servers. You can create multiple sites from with in Aegir some thing similar to what you do on a reseller control panel. If you want to restrict the subdomains to a single domain then you can use the module Hosting Subdomains

So it ultimately depends on your use case.
Answer: I think I found the answer on this
This is the module https://drupal.org/project/domain_rules
So a user can select a name and a new domain with this name will be created.

User defined domains


blender 3.2 - N pannel Addons tabs to small

Question: Sometimes there are so many addons the names are not visible.
Is there a way to on mouse over "tool tip" the N Pannel addons to see the name, or make the tabs larger?
Answer: Solution #1 - Filter add-ons

Solution #2 - Zoom in/out tab sizes
You can use CTRL + MMB-drag to adjust the size of your right, 3D viewport sidebar. This method can be similarly done to other UI panels to adjust their sizes as well.
Video - Footage
https://www.youtube.com/watch?v=XM0E5HEyMIA
Screenshot - Before

Screenshot - After
Comment: I'm not getting that result. Are you clicking in the viewport, or on the actual tabs?
 "CTRL + LMB-drag to adjust the size of your right, 3D viewport sidebar"
Comment: ctrl+ MIDDLE MOUSE did work, except it does the opposite. the smaller the tabs the more text. the larger the tab, the tab text disappears because it's getting to big to fit in the tab area.
Comment: [1] Click-dragging either the viewport panel or the panel tabs works. [2] I made a typo in my post when saying, "LMB," instead of, "MMB," as you caught. [3] See this answer on how to filter those 3rd-party tabs: https://blender.stackexchange.com/a/172505/123064


Comments since Nov 25 disappeared

Question: At least some of the comments I posted on Medical Sciences SE since Nov 25 disappeared - there is no mention of them being deleted, and I'm sure I haven't deleted them. Is there some function where this happens automatically?
Comment: No, that doesn't happen automatically but any mod can delete comments at any time and sometimes we do. The reasons vary, so you'd have to give a specific example to know why. The most common reason (for me) is because the comment has become wrong or irrelevant as more information has come to light.
Comment: Personally, I would say deleting a comment without giving a reason and/or informing whoever wrote it is Bad (mind the capital B).
Comment: @Thomas Welcome to SE, get used to it.
Comment: Thank you for your comment. Please be bitter elsewhere.
Comment: I'm voting to close this question because further discussion is unlikely to yield relevant contents.
Answer: There are a few situations where comments are useful, such as improving the clarity of questions/answers, providing transient (i.e. non permanent) information, etc. Comments can be deleted by owners, moderators or the system if it is flagged enough. Comment chains can also be moved to chat if that is deemed warranted.
From the Stack Exchange Meta on commenting:

When should comments be deleted?

Comments are temporary "Post-It" notes left on a question or answer. You should not expect them to be around forever. Once a clarification has been made, an edit added to the post to include new information, or the issue in the comment is otherwise resolved, it can be deleted. Additionally, any comment that violates the comment guidelines listed above or the Code of Conduct is subject to deletion.

In reality, on most sites, many since-obsolete or guideline-violating comments don't end up being deleted due to the high volume of comments posted, but this does not mean that they can't or shouldn't be deleted in the future.

If you encounter a comment that has since become obsolete or that violates the commenting guidelines above or the Code of Conduct, you can flag it for deletion.

If you believe it was deleted in error or still provides some use, you can link to the question and it can be looked at again.
Comment: @Thomas There isn't really a mechanism here to inform when/why comments are removed. That goes hand in hand with them being ephemeral. If you have contributions you want to keep record of those should be in posts, perhaps by editing.
Comment: @Thomas - Any time a post is edited, it floats back to the front page. Any post has an edit history that is plainly visible for anyone to see. And if you feel strongly about comment deletion needing author notification and such, you are welcome to post that as a suggestion on the main meta. That's what it is for.
Comment: Unfortunately, it still does not explain where or why my comments are gone. These are possibilities, and I'd like a concrete answer. That aside, my opinion on deleting them without informing the author and without giving reason stands.
Comment: "Comments are temporary "Post-It" notes left on a question or answer. You should not expect them to be around forever." With regard to that I'd add I do not expect any content posted here to be around for any given amount of time at all. What I had hoped for was a bit more transparency with regard to editing in general (although I understand this is not Wikipedia). That said, and as it's not that important a subject, I consider this topic closed.
Answer:
Is there some function where this happens automatically?

No, there is no script comments that automatically remove comments (unlike questions, which are removed automatically). Comments are manually removed by moderators. Personally I find it very disrespectful that deleted comments can't be accessed by the authors and that SE lacks a convenient way for mods to give some reason for comment deletions.
Related:

Why did my comment get deleted?
Some moderators are too quick to delete comments
Are comments pointing to other potentially useful resources ephemeral?

Comments since Nov 25 disappeared


Silex doctrine and debugging

Question: I m actually building an application with silex and doctrine.
Actually, in developpment mode in works great and I can access my database.
The fact is now I changed my db information to match with my OVH mysql.
Now, when I try to start my application on my OVH domain, I got
Whoops, looks like something went wrong.

And nothing else.
I don't know at all how to get more informations about it and can't find any working solution to log the detail of the failing state.
Thanks for you help
Comment: Checked the error logs (application and web server)?
Answer: In order to make it works, enable the debug :
use Symfony\Component\HttpKernel\Debug\ErrorHandler;
use Symfony\Component\HttpKernel\Debug\ExceptionHandler;

// Set the error handling
ini_set('display_errors', 1);
error_reporting(-1);

ErrorHandler::register();

if ('cli' !== php_sapi_name()) {
    ExceptionHandler::register();
}

$app = new Silex\Application();
$app['debug'] = true

$app->run();

You can also catch exceptions like follows :
$app->error(function(\Exception $e) use ($app) {
    print $e->getMessage(); // Do something with $e
};

Silex doctrine and debugging


When it comes to private airports those marked on sectionals with (Pvt) what frequency's do they use if any at all

Question: As the title says for private airports and planes that fly in and out of them is there a frequency that they use and if so where can it be found?
Comment: There are a few (pvt) Private-Use airports that actually publish a frequency to use in the data next to the airport symbol on a sectional chart.
Answer: Referencing AIM:  Services Available to Pilots/Summary of Recommended Communication Procedures (Link).
No Tower, FSS, or UNICOM
-Self‐announce on MULTICOM frequency 122.9
However - as you may expect, the short of it is - it's private - so nobody will be listening most likely.  I'm only listing the AIM reference as the most authoritative source - which even then - likely doesn't even fully cover this.
I'd have to imagine that some of these are owned by individuals living on a ranch like setting in a remote area, and assume that they are going to be the only individuals using the runway (unless an emergency happens).  Even if an emergency happens, the individual is unlikely going to be listening to this radio.  In this "individually owned" scenario, it's also unlikely any pattern work is going on.
In other situations, these may be owned by a flight school or a private group.  I'd have to imagine in this case - they select one of the common CTAF frequencies also published in this table.
General Note:   The owners of these opt to chart them for your safety in case of an emergency, and not much else.  Some may be more generous and allow you to reach out to them with advance planning in certain limited circumstances.  The bottom line is to realize that these fields are private for a reason.
Comment: There are a few (pvt) Private-Use airports that actually publish a frequency to use in the data next to the airport symbol on a sectional chart.
Answer: FAR's specify that private airports can not have a CTAF frequency assigned. The most correct answer is MULTICOM 122.9 as mentioned above, per AIM section 4-1-11, table 4-1-2. As far as nothing much happening at private airports, I've been flying from one for over 15 years and we routinely have 10-15 aircraft based there. Yeah, there is radio traffic. Now, since you're not supposed to land at a private airport without permission, you should just ask what frequency when you ask for permission to land, right? There are a few private airports that still use 122.75 (air-to-air) which at one time was also for them too, but the FAA dropped that frequency assignment from the FAR/AIM a few years ago.
Comment: what FAR talks about that?


Are there algorithmic tools for computing poincare residues?

Question: In Schnell's note on Computing Picard-Fuchs Equations he gives a recursive method for computing residues on hypersurfaces. In short, if you have a meromorphic differential form
$$
\frac{dw}{w^k}\wedge \rho
$$
where $w$ is the local coordinate vanishing on a hypersurface $X$, you can write down a cohomologous meromorphic form
$$
\frac{d\rho}{(k-1)w^k}
$$
He claims that you can rewrite this in a manner as above. He then also claims that once $k = 1$ you can write is down as
$$
\frac{dw}{w}\wedge \alpha + \beta
$$
and then the residue of this is $\alpha$. Unfortunately, I do not see an easy way to write down equations like this in general. Are there computer algebra tools which can accomplish this for me? The main test examples I am looking at are Fermat hypersurfaces (defined by $F=0$) and the differential forms
$$
\frac{\Omega}{F}
$$
where
$$
\Omega = \sum_{i=0}^n(-1)^i z_idz_0\wedge\cdots\wedge\hat{dz_i}\wedge\cdots\wedge dz_n
$$
Answer: This answer of mine might help. To compute in concrete examples the Jacobian ring any computer algebra tool (e.g. Macaulay2) will do.
Comment: Unfortunately, this is not what I am looking for, but, I appreciate your answer. I just want to get a better understanding of **how** to compute residues by hand just for the sake of it.


$chsh command security with Set-UID

Question: Why does $chsh have to be a Set-UID command? What are the vulnerabilities of a normal user changing his/her own shell from perhaps bash to zsh?
Any help would be greatly appreciated!
Comment: There is no `$` within the name of this command on any Unix. Its correct name is: `chsh` or `/usr/bin/chsh`.
Answer: chsh is setuid because in order to change a user's shell, it must modify the root-owned read-only /etc/passwd file.
The system administrator may wish to limit which shells a user may choose, for example if users are assigned a shell which logs all commands to syslog.  The traditional way to do this would be to remove all other shells from the /etc/shells file, as chsh restricts users to choosing shells in that file.  (That then implies that for any users who aren't restricted in that manner, an administrator needs to change their shells by hand - editing /etc/passwd - since they can no longer use chsh to do it.)
Comment: Should a system admin. restrict normal users from changing their own shells? If so, what security concerns may arise if normal users are able to change their shells?
Answer: There is no vulnerability for a normal user to change their shell.
However, a user's shell is stored in the user database, together with other sensitive fields. Most Unix variants store the database of local users in a single file, /etc/passwd. (The name comes from the fact that the original Unix stored users' passwords in that file; on modern systems, passwords are no longer stored in /etc/passwd, which is world-readable, but in a file that isn't world-readable, such as /etc/shadow on Solaris and Linux.) While allowing a normal user to change their shell isn't a security concern, some other fields are sensitive (e.g. the user ID) — but mostly, the file contains information about all users, so allowing a user to modify it would be disastrous since they could change anybody else's account.
Thus users can only modify /etc/passwd indirectly, through commands such as chsh and chfn.
Furthermore, it would be a vulnerability to allow restricted users to change their shells. An account can be restricted to run a specific command by setting that specific command nothing as their shell (or even or effectively prevented from logging in altogether by setting /sbin/nologin or /bin/false — or /bin/true for that matter — as the shell). If the user was somehow able to change their login shell, they would evade the account restriction. The restriction is implemented in chsh by refusing to change the shell if the user's current shell is not in a whitelist of permitted "generalist" shells stored in /etc/shells.
Additionally, the chsh command refuses to change a user's shell to a shell that isn't in this whitelist. This ensures that users won't lock themselves out of their account by setting a bad shell there, which isn't a security concern but is a support concern.
To summarize, chsh has to have elevated privileges because it needs to modify a file that's shared among all users. This allows chsh to apply additional useful policies.
While it would be possible to split out the shell into a separate per-user file, that would require a more complex design with one separate file per account. Unix was based on simple designs, with information stored on flat text file. Fine-grained access control with one datum per file is not traditional, would have a performance impact (not a big one nowadays though), and the advantages in terms of security (not requiring chsh and chfn to have elevated privileges) are pretty small. So there's no compelling reason to change this design.
While it would be possible and relatively simple to make /etc/passwd owned by a dedicated system account (or better, a group), and make chsh setuid (or better, setgid) to that dedicated account, there wouldn't really be a security benefit. If you manage to exploit chsh, never mind what else you can do with chsh itself, you're pretty much guaranteed to be able to allow yourself access to the root account.

$chsh command security with Set-UID


Can I store a soup in my cast-iron in the refrigerator for up to 24 hours in the cast-iron pot?

Question: Can I store a soup in my cast-iron pot for up to 24 hours in the refrigerator?
Comment: This question does not provide enough detail for us to answer it usefully.  What kind of soup?  Are you concerned about spoilage, flavor, or damage to the cast iron?  Please see https://cooking.stackexchange.com/help/how-to-ask
Comment: Just to be clear, are you talking about a pot with a seasoned cast iron surface (no coating)?  Some cast iron pots are enameled on the inside, and they would not be reactive (and thus more suitable for storage).  Otherwise, see Lorel's answer.
Answer: Perhaps there are some types of soup that would be ok, but many foods can easily pick up a metallic taste from cast iron if left in the pot overnight. Examples are tofu fried in a cast iron frying pan, egg omelet (egg sometimes even becomes gray), and anything tomatoey. I'm sure there are others, especially mildly flavored foods, and acidic ones.
So in general, rather than find out the hard way with your particular type of soup, I recommend changing containers for storage in the refrigerator.


What spirit goes best with lasagna?

Question: My mom's favorite dinner is lasagna with salad, garlic bread, and cheese cake. I make this for her every twice a year; her birthday and Mother's day. What spirit goes best with this dinner?
Answer: Not a spirit, but I would serve red wine. In particular a Barbera d'Alba or maybe a Chianti. Red Italian wine seems appropriate and those two are good with pasta in my opinion. It does depend a bit on the kind of lasagna. I'm assuming the standard red tomato sauce kind.
Answer: What spirit goes best with lasagna?
Whiskey or bourbon would be my recommendation for pairing spirits with lasagna. Both go well with pasta dishes and Italian foods in general.
If you prefer beer, please check this out: What's a good beer to go with lasagna?
If you desire wine being paired with lasagna the following may be helpful: 10 Wines that Pair Perfectly with Lasagne

What spirit goes best with lasagna?


adjustable pressure relief valve on a gas water heater

Question: Is it necessary to have to adjustable pressure relief valve and a t&p valve on a gas water heater, or can this be bypassed?
Comment: Only if you like [explosions](https://www.youtube.com/watch?v=rGWmONHipVo).
Comment: I'm not sure what an "adjustable pressure relief valve" is, but you definitely need a temp & pressure relief valve.  It is a safety feature for if something goes wrong.
Answer: Yes !!!  it is absolutely necessary to have a T&P valve to prevent the water heater from exploding if for some reason the pressure was to become to great and keep building. If the pressure in the water heater increase above the safe limit the T&P valve will open and allow some of the expanding water to escape out until the pressure reduces to a safe level,  then the spring in the valve will close again.
I have not heard of an adjustable pressure valve for a water heater,  Some home have a pressure regulator on the incoming water supply line so you can set (reduce) the water pressure to some other value than the incoming pressure from the city supply.


php not working with apache install

Question: I have a centos server. I have installed apache 2.2.17 from a .tar.gz file. I've also install php 5.3 from the ius repository. That worked fine and apache is functioning and so is php 5.3. However, when i put a phpinfo.php file in the directory that apache should be serving files from, it doesn't work. I can only seem to get php to work if i use yum install httpd which installs an older vesion of apache. Any ideas? Thanks.
Answer: Assuming that you're installing a PHP module for Apache, you need to be using the same version of Apache it was built against.  It's a bad idea to try to mix-and-match source packages and binary packages like this.  Either find a reputable repository and install everything from there, or build everything from source, but trying to mix it up like this will usually lead to this sort of problem.
Answer: As larsks mentioned, you're mixing and matching versions.  That's why grabbing the version from Redhat's repository's worked.  Do you really need the functionality provided in any of the newer versions of Apache?  If not, go with the version provided by  RedHat.  It will have all the same security patches you'll find in the latest official Apache version.  And it will obviously work with your version of PHP.  And it will be far easier to maintain than the tarfile dump you're using now.
Answer: Open /etc/httpd/conf/httpd.conf using any editor like nano or vi, the go to section <IfModule mime_module> and make sure that you have this two lines:
AddType application/x-httpd-php .php
AddType application/x-httpd-php-source .phps

If you don't have them the add them and restart you apache like so:
/sbin/service httpd restart

php not working with apache install


What could happen if I touch a constant current source for example 5 Volts 1 Amp..?

Question: Yes, I am talking about a constant current source not a voltage source. Would the 1 Amp go to my body?
Comment: if the constant current source is able to ramp up the voltage until 1 A flows through you, then yes
Comment: This also gives relevant information: https://electronics.stackexchange.com/q/487891/152903
Answer: If you touch a 1 amp constant current source with a maximum voltage of 5v, then the very large impedance of your body will max out the voltage of the source, resulting in 5v and essentially no current flow.
Comment: @Rocket I would touch a 1A current source capable of outputting a maximum of 5V before I would poke my finger with a pointy wodden toothpick.
Comment: so basically a 5 volts 1 Amp is safe?
Answer: Under these conditions (extremely high load resistance), your 1 A constant current source will behave as a 5 V constant voltage source.
Answer: The maximum power it can output is \$5W\$.
Human body's resistance varies between \$1k\$ to \$100k\$;so the \$1A\$ current source fails doing it's job and pumps only \$50 \mu A\$ to \$5 mA\$ through your body.
Answer: At low frequencies (DC) nothing would happen as the compliance of the source is too low and the body impedance is too high,thus very little current would flow.  But, if this is RF you could get a nasty burn or sever electrical shock.
Comment: Welcome to EE.SE. It is unlikely that the OP (original poster) will understand what 'RF' stands for. Hit the edit link below your question ...


whatsapp problem.

Question: I cant recieve messages on my whatsapp.
 Only one tick shows up when sending texts but the recipient receives it and but cant receive his reply.  I've tried rebooting and also its updated.
I can see online people and change profile picture
Comment: Try clearing the cache. Settings > apps > WhatsApp > Clear data and cache
Answer: This can also happen due to flickering data connection. Please ensure that you have stable data connection.
Also try following steps:
Go to File commander > Internal Storage > WhatsApp > Database.
Try clearing the Database folder.
This should work for you.

whatsapp problem.


Easiest way to copy a MySQL database?

Question: Does anyone know of an easy way to copy a database from one computer to a file, and then import it on another computer?
Answer: Here are a few options:
mysqldump
The easiest, guaranteed-to-work way to do it is to use mysqldump.  See the manual pages for the utility here:
http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html
Basically, it dumps the SQL scripts required to rebuild the contents of the database, including creation of tables, triggers, and other objects and insertion of the data (it's all configurable, so if you already have the schema set up somewhere else, you can just dump the data, for example).
Copying individual MyISAM table files
If you have a large amount of data and you are using the MyISAM storage engine for the tables that you want to copy, you can just shut down mysqld and copy the .frm, .myd, and .myi files from one database folder to another (even on another system).  This will not work for InnoDB tables, and may or may not work for other storage engines (with which I am less familiar).
mysqlhotcopy
If you need to dump the contents of a database while the database server is running, you can use mysqlhotcopy (note that this only works for MyISAM and Archive tables):
http://dev.mysql.com/doc/refman/5.0/en/mysqlhotcopy.html
Copying the entire data folder
If you are copying the entire database installation, so, all of the databases and the contents of every database, you can just shut down mysqld, zip up your entire MySQL data directory, and copy it to the new server's data directory.
This is the only way (that I know of) to copy InnoDB files from one instance to another.  This will work fine if you're moving between servers running the same OS family and the same version of MySQL; it may work for moving between operating systems and/or versions of MySQL; off the top of my head, I don't know.
Answer: You may very well use SQL yog - a product of web yog.. it uses similar techniques mentioned above but gives you a good GUI making you know what you are doing. You can get a community project of the same or a trial version from site
http://www.webyog.com/en/downloads.php#sqlyog
This has option for creating backups to a file and restoring the file into new server. Even better option of exporting database from one server to another is there..
Cheers,
RDJ

Easiest way to copy a MySQL database?


Docking station compatibility

Question: I'm using HP nc8430 with advanced docking station EA489AA#ABA. After 6 years of upgrading my notebook I've come to an end and am now considering an HP EliteBook 8560w/8570w notebook that also supports docking station connection.
AFAIK all these devices use the very same proprietary docking connector so I expect it should be possible to connect a newer machine to my existing dock, but I'm not sure about power requirements.
My station supports (AFAIK) 135W of power. I haven't installed any additional disk/other drive into its expansion slots, so all the juice is available to connected machine. And according to official HP hardware there's a 120W official power unit that can supposedly power this notebook. Which gets me to conclude that my docking station should provide enough juice to it.
The main question then
If you have access to EA489AA docking station and 85x0w notebook can you please confirm that newer notebook model can be connected to older docking station and that it works?
Answer: It won't work, not the power requirements, but the docking connector size changed.
I have the same issue with switching between the 84xx series and 856x and 857x series

Docking station compatibility


"Kein Stück" What does it mean?

Question: Watching a German movie and people there keep saying "Kein Stück". Is it some sort of slang? "No pieces" makes no sense. Thank you.
Comment: Although most readers will have an idea what "Kein Stück" means, you should provide the context in which it appears. Theoretically it could be the answer to the question  "Möchtest Du ein Stück Kuchen?"
Answer: It is some sort of slang, or at least rather informal speech. Literally kein Stück translates to not a piece (no pieces would be keine Stücke) and means as much as "not at all". As Javatasse mentions in a comment, a good translation is also "not even a tiny bit".
There is also ein Stück weit, which is the opposite and means "a little bit", "to a certain degree".
Comment: I would translate the sprit of the expression with "not even a tiny bit".
Comment: Thank you for the explanation. "Not at all" makes sense.
Comment: @Javatasse Good point! I added this to my answer.
Answer: This most likely is slang for überhaupt nicht.
Answer: Ganz analog dazu ist auch das verbreitete "kein bisschen."
<code>A: "Du frierst doch!"
B: "Kein bisschen/Kein Stück."
</code>
Es bedeutet so viel wie "not a bit" oder "to no part".
Comment: Deutschlernen beinhaltet nicht nur Schriftsprache, Hochdeutsch und eigenen Ausdruck sondern auch das passive Verstehen anderer. Ich selbst benutze "kein Stück" nicht, aber ich will ja verstehen, was andere sagen wollen.
Comment: Je nach Kontext kann "kein bisschen" passen. Aber bitte nicht "Du frierst doch! Kein Stück."
Answer: The phrase "Kein Stück" depends a bit on context.
Literally (like in @jonathan.scholback extended answer) in questions like "Would you want/like..." it can be used as a direct, a little bit rude, answer of "Not at all".
In a negotiation this phrase changes its meaning. For example on the question "Could you agree a little bit more with me that...?" ("Würden Sie mit mir einhergehen,dass...") the phrase becomes more like "Not a chance". Switches from meaning "I do not want anything" to "I will not budge".
Answer: I'd like to extend Jonathan's answer of "ein Stück weit" to the comparison layer. It's common to use "ein Stück" and "kein Stück" for comparisons (especially if slight deltas are focused):
"Du bist kein Stück besser als er." --> "You are not at all better then him!"
It's also worth to mention the equivalent version with "My" (semantically quite the epsilon from differential mathematics):
"Du bist kein My besser als er".
Further on, the older and not that common "Deut" can be used for many scenarios too:
"Du bist keinen Deut besser als er" --> "You are not at all better then him!"
But in contrast to "My", its common usage fields are a bit reduced. So it's not common to say "Wir sind keinen Deut weiter gekommen". --> "We didn't proceed any further." Maybe this could be the content of a separate question in doubt here.
It's also common to use it within imperative structures that yield quite harsh or absolute aspects: "Keinen Schritt weiter!" --> "Do not move any further!"
Answer: The phrase kein Stück means "not at all".
In this phrase, Stück has the meaning of "a certain distance" or "a little bit". The phrase kein Stück – literally "not even a tiny bit" – is the opposite of ein Stück weit, literally "a small distance", which means "somewhat".
Examples

Ein Stück weit vertraue ich ihm. (I trust him a little. / I trust him somewhat.)
Ich vertraue ihm kein Stück. (I don't trust him at all.)

English phrases such as "I trust him only as far as I can throw him" have the same underlying concept of trust measured in distance.

"Kein Stück" What does it mean?


Many viruses use pressure to pump viral DNA into host cells. Does that mean these viruses have a narrow acceptance of the genome size?

Question: DNA viruses like bacteriophages and herpes viruses have rigid capsids. The viral DNA is densely packed inside, and the internal pressure is 1~2 orders of magnitude higher than the atmospheric pressure. When the capsids open, the viral DNA is pumped out by the pressure. Considering that DNA is not easily compressible like gas, a slight variation of its length will result in dramatic change in the pressure. As a result, if the DNA is slightly longer, it would be difficult to package it into the capsid during the assembly. If the DNA is slightly shorter, the pressure may be too low to pump the viral DNA out during the cell entry.
Comment: Please quote a source for these claims, as the idea of pressure within viral capsids is new to me at least. How is this supposed pressure generated and what form does it take? Are you saying that there is compressed air there? Are you aware that two orders of magnitude means "100s"?
Comment: Stress in the capsid is the dominant factor throughout early ejection, with the pull due to binding particles taking over at later stages.
https://www.sciencedirect.com/science/article/pii/S0006349506717428
Answer: There isn't enough data to give a clear answer to this question, but I can at least explain what I know.
First, it's not 100% certain that genome ejection of tailed phage and herpesviruses depends on stored pressure in the capsid. This is called the continuum mechanics model; but another possibility, the hydrodynamic model, suggests that the difference in osmotic pressure between the cytoplasm and outside environment allows water to flow through the capsid and tail into the the cell, dragging the DNA payload with it. Personally, I am skeptical of this second model because it doesn't seem to explain herpesvirus genome ejection, and it's not consistent with the lethality of R- and F-type pyocins, which are essentially just decapitated phage tails. But there is still some question as to how the genome gets fully out of the capsid.
Assuming that the continuum mechanics model is closest to correct, the nature of the pressure generated when DNA is loaded into the capsid by the packaging ATPases is not intuitive. From a 2013 review:

At this concentration, DNA is highly condensed, and much of the water that normally hydrates the DNA and its counterions must be removed in order to package a complete genome. Water removal during the packaging process occurs by reverse osmosis, the energy for which is derived from the activity of terminase.

Only about 10% of the energy stored in the packaged phage DNA is due to bending DNA more tightly than its persistence length. Most of the energy internal to the capsid is due to the dehydrated state of the DNA, which is reflected by internal osmotic pressures that reach tens of atmospheres.

...And from the herpesvirus paper linked above:

DNA can fill as much as 60% of the internal capsid volume, with the remaining volume fraction occupied by water molecules and small ions that freely diffuse through the capsid wall.

So, despite what we'd expect from our macro-scale experiences, the DNA IS compressible almost like a gas. Small differences in the length packaged won't change the final pressure dramatically.
Also, many of these viruses use a so-called "headfull" packaging method. The viral genome is copied continuously, with the end of one copy linked directly to the beginning of the next copy. The ATPase motor packs this continuous chain of genomes into the capsid until the pressure reaches a certain level, then the motor stops packaging and cuts the DNA chain into a piece inside and a piece outside.

When a threshold amount of DNA, representing
about 103% of the SPP1 genome, has been packaged (headful) a
sequence-independent DNA cleavage terminates the encapsida-
tion cycle (Fig. 1A).

So what will happen to a variant of the phage mentioned here, SPP1, if an insertion mutation increases the length of its genome by more than 3%? I don't know, but in my experience with capsid assembly, it's not uncommon for a small number of large capsids to be produced along with the normal capsids, so possibly large-genome mutants can get by until the structural proteins co-evolve to make the larger capsids the new genome requires. Alternately, even if individual virions no longer contain the whole genome, if multiple virions infect a single cell, all genes will be present in at least one copy, again giving the structural genes time to evolve.
Comment: The mechanisms that generate pressure inside the capsid are complex and nonlinear, so you can't really assign a "bulk modulus" to the whole thing. You could probably estimate a modulus for when capsid is 0-30% full, another for 40-55% and another for >60%, with intermediate values in between where no one mechanism is dominant. All the phage motors I know of can "switch gears" to package rapidly when there is low resistance, then package more slowly when resistance is high.
Comment: That makes sense. If DNA is very stiff like water, the pressure will lose quickly as long as only a little DNA is spit out. So DNA must have an effective "bulk modulus" like gas, which enables the capsid to pump out the DNA continuously. Whether the pressure is due to compression, dehydration or Coulomb repulsion is insignificant.


Add a Panoramio-like layer to ArcGIS Online map

Question: I am interested in integrating some type of Panoramio-like layer into a map on ArcGIS.com.  My objective is to be able to use the qualitative, place-based data offered by the photos with students who routinely use ArcGIS Online.  It appears that Panoramio will no longer be available.  Is there an alternative and can it be added to AGOL?
Comment: https://www.flickr.com/services/api/ sends requests back in REST,XML-RPC,SOAP,JSON,PHP which ArcGIS Online can consume.
Comment: Can you elaborate on "use the qualitative, place-based data offered by the photos" that was available through Panoramio?
Comment: To elaborate: The photos can be used in conjunction with quantitative data to aid in the understanding of place.  For example, percentage of people who practice subsistence agriculture could be quantitative data while the actual photo of someone working on their plot provides the context associated with qualitative data.  For 15 year olds who have never really traveled outside of the U.S. this can be quite helpful and engaging.
Comment: Thank you Mapperz.  What is the general method for incorporating flickr into ArcGIS Online?  I am not interested in adding my own photos.  Rather, I would like to add the publicly available photos to the map.
Answer: Google provides a transition to their other products which maintain the same placed-based data as Panoramio provided here.

Today, with photo upload tools in Google Maps and our Local Guides program, we are providing easy ways for you to share your photos with an active and growing community. As such, we've decided to move forward with closing down Panoramio. To make this transition easier, we'll provide several options to continue sharing photos through other services. If you choose, you can also export all your data and take it somewhere else.

Additionally, I came across this Esri map template which provides you with the ability to:

Present a map with geolocated content from Twitter, Instagram, Flickr, YouTube and webcams.travel. Optionally allows users to swipe between layers and print maps.

It also provide the following configurable options

Configurable Options
  Public Information present content from a web map with social media feeds and can be configured using the following options:
Provide a title and description, as well as configure a custom splash screen that displays when the app is first loaded.
Set up an interactive layer for taking notes. This is a map notes layer contained in the web map.
Enable a swipe layer and choose between vertical or horizontal orientation.
Determine a default and alternate basemap to be offered in an on screen basemap widget.
Enable layers to be generated via content from Instagram, Flickr, Twitter, Webcams.travel, and YouTube.
Configure the ability for feature and location search.
Enable or disable many UI and mapping configurable options such as overview map, bookmarks, share dialog, legend, summary information, views count, modified date, etc.


Had vs was grammatical part

Question: Can we write I had born instead of I was born? Please explain it. Which one should I write in a sentence. Please explain elaborately.
Comment: Your use of the word "elaborately" is odd and unnatural.  You should remove that sentence.
Answer: No.
Born is an odd word.  It isn't the regular past participle of "bear" (that is borne) It is nearly always used in the phrase "be born", which is derived from a passive voice expression but should not now be analysed as a passive.
On the other hand "had borne" (sometimes written "had born") would be a past perfect and an active voice.  It would almost never be used.

I was born in France (correct)

I had born in France (incorrect)

My father came to America in 1945. My mother had borne him a child (me!) in France during the war.  (correct but very odd phrasing)

Had vs was grammatical part


Getting a differential equation from a parametric function family

Question: I have two parametric function families and i need to find the differential equation they satisfy.
I'm very lost on this one. I tried to write $y=y(x)$ using similarities between the two families.
But i couldn't come far as what i got was always far from the real solution.
$$ x=ce^{-t}-2t+2   \\\
 y=c(1+t)e^{-t}-t^2+2$$
How sound i approach such problems?
Edit: I am looking at functions $x$ and $y$ as on two parametric function. So they are functions of parameter $t$. I want to find some interdependece between them and possibly some derivatives.  Both $x$ and $y$ are dependant on $C$, which is a constant. The final equation should be without it.
Shortly, I am looking for a differential equation that those functions solve.
I tried with something like $ \frac{dy}{dx} = \frac{dy}{dt}  \frac{dt}{dx}$, but I didn't get any good results.
Comment: First of all, the differential forms tag is inappropriate, as is the analysis tag. Your question is not clear. You have two functions of $t$, each depending on a parameter $c$? You're saying that these are both the general solution of a single (presumably second-order?) ordinary differential equation? Please make your question clearer.
Answer: This is not an answer but a comment too long to be edited in the comments section.
$$ x=ce^{-t}-2t+2   \tag 1$$
$$y=c(1+t)e^{-t}-t^2+2 \tag 2$$
I agree with the Ted Shifrin's comment. Supposing that the problem is to eliminate $c$ and $t$ in order to get a differential equation  involving only $x,y,\frac{dy}{dx},\frac{d^2y}{dx^2},...$ , they are an infinity of possible answers depending on the kind of differential equation and the order expected.
For example, for a first order nonlinear differential equation :
Take $ce^{-t}$ from $(1)$ and put it into $(2)$
$$y=(1+t)(x+2t-2)-t^2+2 \tag 3$$
Differentiate $(1)$ and $(2)$
$$\begin{cases} \frac{dx}{dt}=-ce^{-t}-2 \\
 \frac{dy}{dt}=-ce^{-t}t-2t\end{cases}\quad\implies\quad \frac{dy}{dx}=t \tag 4$$
Putting $t=y'=\frac{dy}{dx}$ from $(4)$ into $(3)$ gives the ODE :
$$y=(1+y')(x+2y'-2)-y'^2+2$$
But probably this is not what the question is asking for. The question should be clarified.


Is it possible to replace a DIAC circuit with an SCR circuit to drive a TRIAC

Question: I have a triac DIAC cirtcuit. I don't have any DIACs on hand, but I do have plenty of TN1215s. Is it possible to generate the required pulses using an SCR to drive the TRIAC's gate?
Comment: Maybe- with a bridge rectifier and a zener to the gate but it will be very high trigger current with that particular SCR and will require changing other component values and ratings. People are throwing out that kind of dimmer now because they don't handle LED lamps well- you could salvage.
Comment: @SpehroPefhany Or get a $0.1 DIAC, of course.
Answer: The circuit will quite likely work without the DIAC - i.e., short out where the diac should be until you can get one - but may be a bit "twitchy".
Without the DIAC the TRIAC will turn on when the trigger voltage gets high enough. The problem is that this is not very well defined and will vary depending which quadrant the triac is operating in and, probably, with temperature.

Figure 1. Trigger angle and resultant waveform.

Figure 2. Triac triggering modes and quadrant numbers. Source Wikipedia (with addition of numbers).
Note that your circuit works on quadrants 1 (both mains and trigger positive) and quadrant 3 (both negative) only.
If the triac triggers levels in the first and third quadrant then there may be a noticable flicker between positive and negative half-cycles particularly on the  romantic end of the pot.
The DIAC solves this by holding back the trigger until the capacitor voltage rises to about 22 V (if my memory is right) and then allows the capacitor to discharge through the gate pin. The point is that a fraction of a volt difference on 22 V will result in less phase angle difference between positive and negative half-cycles than directly triggering. The downside with the triac is that you can never get 100% power.
Comment: Hmmm.  So an SCR circuit cannot replace a DIAC?
Comment: Not directly, anyway. The DIAC is bidirectional and in your application both directions are used. An SCR isn't and won't work on its own at least.


Combining ANSI Color codes -- Foreground and background color merging

Question: I have this function in zsh to run grep on the output of git log to highlight the line with the commit's hash, author, message, etc.. I'm rewriting to try and add color to the output and want to prevent grep from overwriting the foreground color that's passed.
I've tried all variations of --color=(always|never|auto). This is the current command I'm stuck with:
# raw command:
unbuffer git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' | grep -i '.*'update'.*' | column -t -s $'\t'

# w/ comments:
unbuffer # From `expect` apt package, preserves color across piping by pushing to a buffer? idk.

# git log, formatted
git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)'

grep -i '.*'update'.*' # grep `update` from any line in input, hardcoded here but could also be a parameter

column -t -s $'\t' # tabulate

The output looks like this.

In addition, piping to column to tabulate the output without the use of unbuffer also washes away the color and there's no --color=never option for the column command. The use of unbuffer also causes grep's coloring to not work at all.
What I want is to just have the background of the grep match to be highlighted red, green, or whatever color while preserving the color of the text as seen in the image, i.e. green on red, blue on red, etc. I'm not completely familiar with how terminals work under the hood and why color is lost when piping.
I'm sure I could write a C++ program to do all this by inserting ANSI color codes where necessary but I figured I would at least ask. I do want to only use commands that can be installed via apt as this is a part of my whole terminal config that I sync across multiple devices via a git repo..
Edits below this point:

I originally tried to include a -A1 -B1 flag with grep to show the commit before and after, hence the desire for explicit highlighting.
The answer from @daniel-t works for resolving coloring being lost by git log, but disables grep from highlighting matches.

I am able to achieve the desired effect by writing color codes manually into a string and echoing via echo "\e[1;34m13ca348\e[m \e[1;36mSun, 29 Jan\e[m -- \e[1;41m\e[1;32mCommit message\e[m". This output is exactly what I'm looking for (notice the green on red from wrapping the foreground and background color codes) but I doubt terminal programs structure colors this way so I don't know if another program would be able combine them easily this way .
Answer: So I was able to find a solution. Setting GREP_COLORS inline with the grep call allowed me to change grep to only highlight the background without conflicting with the foreground coloring from git log. I also had to pass --color=always in grep to prevent washing when piped to column like so: GREP_COLORS="ms=41" grep -i update --color=always

See: https://askubuntu.com/a/1485711/1764786 for a table on GREP_COLORS placeholders

Also the issue with column is that it doesn't support every ANSI color escape and ends up washing any it doesn't like. My fix for this was to use column_ansi and that acts as a drop-in replacement (mostly).
Like I said in the edit, I was trying to include the flags -A1 -B1 in grep to get the commit before and after.
Here is the full command I ended up using and I ended up wrapping it in a function:
glgrep() {
    git log --color=always --pretty=format:$'%C(bold blue)%h%C(reset)\t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' | GREP_COLORS="ms=41" grep -i $1 --color=always -A1 -B1 | column_ansi -t -s $'\t' | sed 's/^[ \t]*//;s/[ \t]*$//'
    # call after `column_ansi` requires trimming. i dont know why (extra following newline char?)
}

Comment: The "format:" in "--pretty=format" is not recommended because it might eat the final newline. It's better to specify "tformat" instead or leave it out to automatically do so.
Answer: Last solution
Try git log --color --pretty="$(printf '\e[1;34m%%h \e[36m%%aD\e[35G\e[;2;37m\t%%an\e[70G\e[;37m%%s\e[m')" | GREP_COLORS='ms=1;32;41:sl=37' grep -Pi '\e\[;37m.*\K''update' --color=always. I eliminated the use of column and sed. The new \e[70G just moves the cursor to column 70, and that should be enough for names. The first two columns are more or less fixed-length and don't need much.

Simple solution
Try git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(bold green red)%s%C(reset)' --color=always | grep -i '.*'update'.*' | column -t -s $'\t'. I just changed the last "white" to "bold green red".

Based on your desired color code example highlighting the entire commit message, it was easy to color the entire last column. There is no need for combining colors from two commands. I don't know which version of grep you are using that has red as the background, but the grep on Ubuntu has red as the foreground, so we needed to override this.
Advanced solution
EDIT: Based on what you seem to want:
The command becomes git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' --color=always | GREP_COLORS='ms=1;41;32:sl=37' grep -Pi '\e\[37m.*\K''update' --color=always | column -t -s $'\t'. Edit the 'update' part to choose which pattern to search for.

The GREP_COLORS environment variable controls how grep highlights and is separated by :. ms=1;32;41 applies bold green on red, respectively. grep will reset the colors immediately after, so we need to add sl=37 to get back the white (necessary on xterm but not most terminals like Konsole). ANSI color escape sequences would normally merge with the previous foreground, background, or style if omitted, but you can't push/pop/undo so that doesn't work for your case. I then match for \e\[37m (requires -P) to restrict us to the commit message (to avoid glitchy colors in case it matches elsewhere), relying on the fact that we only use white in git once. Then the .*\K tells grep to search for your keyword after, and to avoid highlighting and ruining the previous color code itself. Finally we need --color=always to enable our new colors.
By the way, you don't need to use reset so much. Here is a shorter version git log --color --pretty=$'%C(bold blue)%h \t%C(cyan)%aD\t%C(reset dim white)\t%an\t%C(reset white)%s%C(reset)' | GREP_COLORS='ms=1;32;41:sl=37' grep -Pi '\e\[;37m.*\K''update' --color=always | column -t -s $'\t'. The middle ones are still there because they are more reliable than no-dim (same color code outputted as no-bold), and the last one is only needed if you don't have a colored bash prompt.
Old answer
You need to pass --color=always to git, not grep or column. Try git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' --color=always | grep -i '.*'update'.*' | column -t -s $'\t'.
I get the following output:
home@daniel-tablet1:~/WebstormProjects/linuxenv$ git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' --color=always | grep -i '.*'update'.*' | column -t -s $'\t'
13ca348   Sun, 29 Jan 2023 15:56:02 -0500    Daniel Tang  Update PlantUML 1.2022.6 -> 1.2023.0
83b31a2   Sun, 29 Jan 2023 15:48:21 -0500    Daniel Tang  Update Gradle 7.5.1 -> 7.6
85f2b04   Sun, 29 Jan 2023 15:45:28 -0500    Daniel Tang  Update GraalVM 22.3.0 -> 22.3.1
5e86df9   Sun, 29 Jan 2023 15:39:59 -0500    Daniel Tang  Update JetBrainsMono 2.242 -> 2.304
7e984d4   Wed, 26 Oct 2022 18:21:23 -0400    Daniel Tang  Update graalvm 22.3
ee202a6   Wed, 12 Oct 2022 10:00:33 -0400    Daniel Tang  Update rustup settings.toml hash
6a0c58f   Mon, 19 Sep 2022 23:54:54 -0400    Daniel Tang  Update
a9755a3   Tue, 23 Mar 2021 13:54:27 -0400    Daniel Tang  Fix nvmupdate
e936dab   Fri, 19 Mar 2021 17:29:32 -0400    Daniel Tang  Update
0b8e7e3   Wed, 17 Mar 2021 04:19:11 -0400    Daniel Tang  Update
(sky blue)(turquoise                    )    (dark grey)  (white) (konsole)
(RGB blue)(cyan                         )    (dark grey)  (light gray) (xterm)
(navyblue)(aquamarine                   )    (dark grey)  (light gray) (gnome-terminal)

I removed unbuffer because it not only needed to be installed, but also causes the command to hang on my computer. The standard command for what you desire is stdbuf -o0. If you say that unbuffer was fixing the colors, that must be because it was pretending to be a terminal by allocating a PTY. That is unnecessary if we use the more efficient direct solution of --color=always.
If you wanted to find out which command was failing to pass on the color, you can use cat. git log --pretty=$'%C(bold blue)%h%C(reset) \t%C(bold cyan)%aD%C(reset)\t%C(dim white)\t%an%C(reset)\t%C(white)%s%C(reset)' | cat results in missing color, and without the cat there is paging and color. This shows that it's git that fails to emit the ANSI color codes. Even if you wrote a C++ program, those are your own color code, and no color codes from git.
Don't worry about grep overwriting your color code. Your .*'update'.* goes to the start of the line. A color code is specially chosen text with escape sequences. Even if grep appended any color codes, it will be overwritten by git's color code immediately after. The head -n1 output of the git --color=always is \e[1;34m9a8c818\e[m \t\e[1;36mMon. In this case, it's good that grep did not decided to insert color codes because it was pipe to something, namely column after, but even if you gave grep --color=always, it just prepends it color codes. I get \e[01;31m\e[K\e[1;34m13ca348\e[m \t\e[1;36mSun, 29 Jan. It appears the same visually because the grep's colors are immediately overwritten by git's colors from earlier.
Comment: Also, I work on WSL in Windows Terminal. So I assume there's some external reason as to why the native `column` wasn't working for me but seems to have worked for you. I was still able to reach a solution so thanks for the help.
Comment: It's common for many commands to not include non printing escape sequences when a pipe is detected (as those might cause parsing/processing issues.) ... Not only `grep` in this situation but also `git` as it seems which could be the root cause for the issue in OP.
Comment: This resolves the color loss, but does not achieve the desired effect of explicit background-highlighting. I edited the original post with additional info.
Comment: @Sargates I was able to find a solution that eliminates the `column_ansi` and `sed`
Comment: Your command doesn't work for me. Using the native `column` washes the "dim white" (grey) after the `column` call, every other color remains, which is why I looked for an alternative tabulator. I found other people talking about issues with color being removed from piping `column`. Which is why I found `column_ansi`. The `sed` call is also an artifact of calling `column_ansi` it seems to have a trailing newline which doesn't happen with native `column`. That's what the `sed` call was for.
It seems we reached the same solution.
Comment: This is why I chose to remove `column` and replace it with `\e[70G`, which should be faster and more consistent. But also thank you for showing me the `GREP_COLORS` part!