How to merge a overlapping points into a single feature to reduce Map "noise"

Question: I have a shapefile of the locations of wind turbines within the central flyway. I was attempting to show the size by the total number of turbines however I am having a problem with many large scale farms being close to each other and it's taking away from the message. I was wondering if there was a way to merge points within a certain distance so that instead of have 9 separate points I could have one large point? I have inserted the image below.
Answer: Have you considered using a heat map style?  It'll remove all the points and show areas of highly clustered turbines.  It can also be based on the attribute of the number of turbines at each site rather than their proximity to each other (as long as you have that number in the attribute table).
In the style properties of the point layer change the style from 'Single symbol'/'Categorized' (whatever you're using in your image) to 'Heat Map'.
Set the 'Weight points by' to the attribute that has the turbine numbers for each site.
See what it looks like then play around with the radius property to get a good spread of the heatmap.  Also changing the 'Layer blending mode' to Overlay or multiply will let you see the basemap beneath more clearly than just changing the layers transparency.
Comment: It was either this or point clustering but I'm not entirely sure how to accomplish that in qgis
Comment: +1 I asked a clarification about the real needs of the OP, but I was pointing to the same solution!
Comment: Hey everyone! thanks for the quick answers! So I was attempt to do more of a tolerance distance. I did the Kernal density and the point density and they are not really reflecting what my data is showing me. I did a hot spot analysis, which I like because it is showing me the areas of higher impact. I am not sure how to select the weight point by? Am I creating the heat map incorrectly?
Comment: Could you ask this as a separate question, including another image with your heat map and what the attribute table looks like of your turbine layer
Comment: yes of course! I can do that if that would help


Stack resolving with planeswalker and instants

Question: I play Nissa, Voice of Zendikar a planeswalker. When it's in play my opponent plays Devour in Flames to deal 5 damage to my planeswalker. I want to use my effect "put a +1/+1 counter on each creature you control" what will be resolve first? Does my creatures get +1/+1?
Comment: If you want to talk about instants instead of sorceries, are you OK with replacing Devour in Flames with Fated Conflagration? This Nissa enters with 3 loyalty counters. Does it matter that the spell does 5 damage? Does that mean that her +1 loyalty ability has been activated already? Or do you mean that this is happening right after she enters the battlefield?
Comment: Yeah its more the if its an instant what would happen, can nissa take damage at the moment of summoning or just after. Could she get damage before shes on the battlefield
Answer: Nissa, Voice of Zendikar is a Planeswalker, which means that you can only activate her abilities on your turn, and Devour in Flames is a Sorcery, which means your opponent can only cast it on their turn. In other words, if your opponent is able to cast Devour in Flames, then you don't have a chance to activate Nissa's ability.
Comment: Sure, with different cards, played at a different time, you would have a different interaction.
Comment: But if it were some instant card or ability that did the damage, after the planeswalker resolves the stack is empty and the active player has priority, so you can always choose to activate a planeswalker ability immediately after it resolves.
Answer: The following assumes that Devour in Flames can be cast by your opponent at instant speed.
Unless Nissa, Voice of Zendikar entering triggers a triggered ability creating a stack, you will immediatly receive priority and be able to activate the loyalty ability before your opponent can cast Devour in Flames.
If Nissa, Voice of Zendikar entering triggers a triggered ability, then stack will not be empty and when you pass priority, your opponent can cast Devour in Flames to destroy Nissa before you can activate the loyalty ability.
From the Comprehensive Rules:

116.3. Which player has priority is determined by the following rules:
116.3a The active player receives priority at the beginning of most steps and phases, after any turn- based actions (such as drawing a card during the draw step; see rule 703) have been dealt with and abilities that trigger at the beginning of that phase or step have been put on the stack. No player receives priority during the untap step. Players usually don't get priority during the cleanup step (see rule 514.3).
116.3b The active player receives priority after a spell or ability (other than a mana ability) resolves.
116.3c If a player has priority when he or she casts a spell, activates an ability, or takes a special action, that player receives priority afterward.
116.3d If a player has priority and chooses not to take any actions, that player passes. If any mana is in that player's mana pool, he or she announces what mana is there. Then the next player in turn order receives priority.

and

606.3. A player may activate a loyalty ability of a permanent he or she controls any time he or she has priority and the stack is empty during a main phase of his or her turn, but only if no player has previously activated a loyalty ability of that permanent that turn.

EDIT: A spell can't be cast until the player has priority. The trick is that the active player (whoever's turn it is) receives priority immediately after Nissa enters the battlefield.
If there is no stack, then the the active player may choose to activate one of Nissa's loyalty abilities. In response the opponent can cast Devour in Flames (assuming it is instant speed), but the loyalty ability will already be on the stack. What will happen is: Devour in Flames will resolve and Nissa will be destroyed and then Nissa's loyalty ability will be resolved.
If there is a stack (for whatever reason) then the active player cannot and after passing the opponent can cast Devour in Flames (assuming it is instant speed). Devour will resolve, destroy Nissa and the active player has no chance to activate the loyalty ability of Nissa.
Also you cannot cast a spell that targets a planes walker while the planes walker is being cast, since at that time the planes walker is a spell and not a permanent.
Comment: But if devour of flames was an instant. Could such an instant be played when the planeswalker is summoned? Or after the summoning?
Comment: I editing my answer with more explanation.
Comment: So if i activated the ability first i will get the benefits of nissa her ability's and if the instant is first i wont get the benefits of nissa's ability.
Comment: You are correct.


Does a bitcoin pool appear as one node or multiple nodes to the rest of the network?

Question: I'm guessing that it appears as a single node?  For example on http://getaddr.bitnodes.io/?
Answer: The pool will typically appear as one node, though there's nothing stopping a business entity identifying as a pool to operate several nodes.
In any case, the miners in the pool will certainly not appear as nodes.


Can I get the input data by directly reading the IOport of an USB keyboard

Question: I am working on the Xen platform, Now I want to intercept the interrupt on HVM domain to read the raw data (scan code) of a keyboard .
One idea is that the hypervisor follows the path UHCI frame list-> TD related to keyboard device -> data buffer to get the raw data. However, when the interrupted is generated, the TD has been remove from the TD list. In this way, the hypervisor can not find the data buffer, and can not read the raw data.
Another idea is that directly read the IOport of keyboard.
I know it is possible to get the input of the PS2 keyboard by reading the IOport 0x60 and 0x64
But my current work device is USB keyboard.
Now my question is that whether it is possible to get the input raw data of USB keyboard
by directly reading the IOports.
If can, how to achieve that, please give me an simple example.
or is there other method to read the input raw data?
Answer: it seems that there is no exported port (e.g., USB-keyboard) for guest to read such information.
but I found that, the UHCI controller does not automatically remove the TD from the list even if the controller successfully complete the data transfer. The deletion operation is done in the uhci-irq function
In this way, we can read the data buffer before the function uhci-irq is invovled.


order of fir filter

Question: Assume we want to filter the audio signal from a digital video disc (DVD) player as shown in Figure P5–3. The filtered audio signal drives, by way of a digital-to-analog (D/A) converter, a speaker. For the audio signal to have acceptable time synchronization with the video signal, video engineers have determined that the time delay of the filter must be no greater than $6 × 10^{−3}$ seconds. If the $f_s$ sample rate of the audio is 48 kHz, what is the maximum number of taps in the FIR filter that will satisfy the time delay restriction? (Assume a linear-phase FIR filter, and zero time delay through the D/A converter.)
http://www.chegg.com/homework-help/questions-and-answers/53assume-want-filter-audio-signal-digital-video-disc-dvd-player-shown-figure-p5-3-filtered-q12575129
Comment: You posted a jpeg image of a multi-part IIR filter problem recently. The problem had a designator of 'Q3', a block diagram of an IIR filter, and mentioned the idea of "120 Hz flicker noise from fluorescent lights contaminating a photodiode signal." ROHAN, I need to find the source of that problem: Did it come from a textbook, college lecture notes, a web site, or just where?  If you help me find the origin of that IIR filter problem I will reward you. Don't reply to me here on Sig. Proc. StackExchange, but rather, please send me an e-mail at R_dot_Lyons_@_ieee_dot_org.
Answer: 577 taps: Since it is a linear phase filter then the dominant tap for a low pass filter will be in the center (as the filter must be symmetric or asymmetric to be linear phase), which therefore sets the total time delay of the filter:  the time delay for a dominant center tap filter is the total filter length / 2 * the sampling rate of the filter.
$$ \frac12 \times (577-1) = (6 \times 10^{-3}) \times 48000 $$
Comment: a 1-tap FIR filter has delay of 0.  and the order of an FIR filter is 1 less than the number of taps.
Comment: Is the formula same for both even and odd length?
Comment: Robert- Yes, thank you. Rohan Paul: If it is even and symmetric then the delay would be half way between: for example the delay of a two tap symmetric filter is 1/2 a tap.
Comment: @robertbristow-johnson alright but $h[n]=\delta[n-9]$ is a single (**nonzero**) tap FIR filter with delay of 9 samples...? May be you're referrig to Type-I,II,III,IV even/odd symmetric causal linear phase FIR filters...
Comment: @fat32 Yes as soon as any non-zero coefficients are present given it is a linear phase filter it must be symmetric or assymmetric. We could of course delay any linear phase filter by adding zeros but since the OP asked for minimum number of taps that would not apply.

order of fir filter


Appropriate to ask what will be covered in a technical interview?

Question: I landed an hour long interview with a senior developer and am pretty nervous. I know it's going to be technical, but is it appropriate at all to ask about what I should expect?
Comment: Asking the HR rep might be ok, but you won't get anything specific or extremely useful. I'd pick up Cracking the Coding Interview and start doing practice problems. I'd expect nearly all questions you would be asked in a standard interview for an internship would be covered in that book. But there is a lot covered in that book, so don't think you need to know everything. And "I don't know" is a great answer, especially if it is followed up by good clarifying questions or accurate suggestions to try out.
Comment: Possible duplicate of [Can I ask the company how the interview will work?](https://workplace.stackexchange.com/questions/9020/can-i-ask-the-company-how-the-interview-will-work)
Comment: what level position are you applying for?
Comment: Software internship
Comment: Then no, it's not appropriate to ask, but these don't tend to be in depth tech interviews anyway, just a gauge of technical aptitude... nothing to get apprehensive about.
Comment: Do you know what kind of skills they are looking for (e.g. from job listing and previous interviews)
Comment: Since people seem to have misunderstood you: do you want to know if you can ask what to expect format-wise to basically calm your nerves a bit or do you want to know if you can ask about the topics that the interview will cover so you can prepare in advance?
Comment: I guess like main topics? even something like "oop" would be enough to make me feel better haha
Answer: Whether or not it is appropriate to ask what the interview will cover is going to be very dependent on the interviewer's opinion. It could go either way:

The interviewer could be bothered by this question. It would be fair to assume that the interview questions will cover whatever skills were listed in the job posting and what you've put on your resume. The interviewer could assume you don't know those topics as well as they want you to if you feel the need to ask what will be covered. It's kind of like asking a professor what will be on a comprehensive final exam (the answer is usually, "everything we covered in the course").
Other interviewers will not be bothered by it. They will have an appreciation for how stressful interviews can be for people new to the industry (which I assume you are since you're interviewing for an internship), and may give you some idea of what it will entail.

Also note that since you're talking to the HR person, they may not even be able to answer the question.
My recommended approach would be to study up on everything that is covered on both the job posting and your resume without asking about it. In my experience, even technical interviews aren't very in-depth, especially in the first round of interviews. They usually understand that even people experienced with a particular technology may not have used it in the particular application used by the company, so some on-the-job learning is to be expected. The interviewers usually just want to confirm a minimum competency.
Since you're in the software field, it also may be beneficial (and fun) to look over questions on CodeReview and some of the challenges over at CodeGolf for the languages you'll be working with. They can both reveal some interesting language constructs (and abuses) if the interviewer wants to throw some curveballs at you.
Answer: Asking the interviewer whether you are expected to prepare anything in advance, should be fine.
The response will probably be a 'no', but it might also reveal what the more exact goal with the interview is.
Personally, I would not study coding riddles as preparation, as that could just as easily increase anxiety on your part.
Answer: If you mean asking the interviewer, i.e., the senior developer, it absolutely is inappropriate. The purpose of the interview is to gauge your skills against the job and you asking for the process in advance is like asking about the documents to study and cheat.
If you have a friend, or a recruiter, who has been through the process before, it might be appropriate to ask them but not in a way that, you are just trying to circumvent the process. It is more like "what do they focus on" or "any particular interest of the developer that I should be addressing" are proper things to ask. "What problem he/she ask you to solve, so that I will have a ready made answer to it" is not a good question to ask anyone.
Comment: I'm going to be responding to the HR rep, not the developer. So it's alright if I ask this HR rep "is there any particular focus of interest of the developer that I should be prepared for?"
Comment: if you are calling an agent of the employer company, I'd stay away from being specific. You can ask, "_I have not been to one of these technical interviews lately. what is expected of me at this interview_" is a good question to ask the HR people. Being prepared for the curve-balls the developer will throw at you and how you answer is how they determine if you are a good fit for the job. Do not expect them to answer this type of questions.
Answer: I think the appropriateness depends on the interviewer. But if you want to play it safe, I would avoid asking. Technical interviews usually cover coding and technical questions related to the position and the language or technology you'd be using on the job.
If you want some idea of what this looks like, you could try solving some coding tests that are used for job interviews. I can also recommend the book Cracking the Coding Interview, which aims to help with technical interviews and is a very useful read.


What is the right way to map different domains in Google Search Console?

Question: I have 2 domains that I want to "map" together in Google Search Console. Each domain is for a different countries:  example.ch for Switzerland and example.de for Germany. How can I group them in the right way so they can share their rankings?
Comment: Can you please explain a bit more. e.g: Are you saying you want to merge 2 domains into 1, or you want both domains live independently, ranking in their respective country google results or something else.  Try and edit your question to be more specific.
Answer: In the classic view of Webmaster Tools, this can be achieved by Grouping Properties into 'Sets'.
This is directly available on https://www.google.com/webmasters/tools/set-edit.
Up to 200 properties can be added in a set, including https vs https, www and non-www version of web properties.
in the new search console, there will be a new way to handle this but is currently unavailable.
Source: Official Documentation
Comment: I don't think this answers the question, it sounds more like he wants to merge the domain into a single domain, hence 'so they can share their ranking'


Why my object keeps moving when the path is over?

Question: I'm trying to make an image to follow a curve path, but even after the curve has finished the object keeps moving tangent to where the curve had ended. I'm following several tutorials but no one is having this problem by default.
Comment: If you continue the path animation to an evaluation time > 1.00 Blender will continue to "follow" the curve by extrapolating onward along a straight line if the curve is not cyclic or by continuing to repeat the motion if the path is cyclic.  Please add a screenshot of your follow path modifier and explain which of several techniques you've used to animate the motion along the curve.
Answer: Just enable the clamp under path animation in curves tab. Your issue will be solved.

I was searching for solution for the same issue and came across your post. Though I couldn't find any solution online I figured it out by myself later on. So, I came back here to share this with you, thought it'll be helpful to you too.


Forces on a ball thrown upwards

Question: When a ball is thrown up in upward direction, it is said that force is in downward direction. Why we don't we consider the force given to the ball to throw up in the upward direction? Is there is no effect of the force given to the ball?
Comment: During the throwing, the net force is upwards. Once you release it the only force is downwards.
Answer: This is a classic misconception that most people share at some point in their lives. For centuries, we struggled to understand this point. For example, the famous Aristotle expresses your misconception that:

continuation of motion depends on continued action of a force

i.e. you see a ball moving upwards, and think that there must always be a force pushing it upwards. That is not the case. The ball has an initial velocity upwards, but the only force acting on the ball once it has left your hand is gravity.
Once the ball leaves your hand, it is moving upwards, but getting slower and slower, i.e. it is decelerating (or accelerating downwards). This deceleration is caused by gravity, a force acting downwards.
Nowadays, this fact is trivial, known by millions, but it was a significant development in the history of physics that confused some of the most famous minds.
Comment: now worries @shyam, hope it's clear now
Comment: YES, thanks a lot for helping me to clearify my long time confusion @innisfree
Answer: You should have a look at Newtons First Law of Motion:
"When viewed in an inertial reference frame, an object either remains at rest or continues to move at a constant velocity, unless acted upon by an external force."
When the ball is moving up and there is no force at all, then the ball will continue it's motion upwards. But when there is gravity, you should look at Newtons Second Law of Motion:
"The vector sum of the forces $F$ on an object is equal to the mass $m$ of that object multiplied by the acceleration vector $a$ of the object: $F = ma$."
While the ball is moving up, you do not interact with it, therefore the only force is gravity, accelerating the ball downwards (slowing it down).
You should not confuse the concept of force with the concept of energy. When throwing the ball up, you accelerate it and therefore you transfer kinetic energy to the ball, not giving it force.
Answer: Once you release the ball, you are not applying a force to it; it is freely falling (despite its upward motion). The only force acting on it is the gravitational force, pulling it downwards (which is why it slows down and stops momentarily at the apex, before coming back down).
See also the related question When a ball is tossed straight up, does it experience momentary equilibrium at top of its path?
Comment: then if it is freely fall,act only by gravity why it moves upward?
Comment: Because the force you applied to the ball to throw it was greater than $mg$ (otherwise it could not move); it then continues *decelerating* as it moves upwards.
Comment: @SHYAMANANDA NINGOMBAM :By freely falling he means the body moves only under the presence of gravity(not any other forces)and the body is moving upwards because the you initially provided a kinetic energy.
Answer: Inao Shyamananda. The act of throwing a ball upward can be studied in two stages.
Stage 1: When you throw a ball up you apply a force to the ball in the upward direction as long as it is in contact with your hand. This force does some amount of work on the ball. This work done is manifest as the sum of kinetic energy and potential energy of the ball. At the end of this stage the ball leaves your hand. The kinetic energy at the end of this stage gives you the "initial velocity" for the next stage through the relation $$KE=\frac{1}{2}mv^2.$$ I hope this clears your doubts about what happened to the force which your hand exerted on the ball.
Stage 2: The moment the ball leaves your hand, the only force acting on the ball now is the gravitational force (neglecting the effect of air). This stage has been clearly explained in the earlier answers.
Answer: Yes,the effect of force with which the ball is thrown is surely considered. When the ball is thrown upwards,the gravity try to pull it downwards and hence after sometime it starts coming down(when gravitational force overcome the effect of force you provided when you threw it).Somehow,for ease of solving,at lower level it is assumed that the only force acting on ball after being thrown is gravitational force.
Answer: Actually, when you throw the ball up into the air the ball will not only be acted on by gravity but friction and resistance from the air molecules colliding with the movement of the ball.

Forces on a ball thrown upwards


Rotation Portrait Landscape with 2 XIB

Question: i have got 2 GUIs and 2 Controllers
1 is called landscapeguicontroller and the second is called highguicontroller.
Now generally i call the highguicontroller, and when i rotate my iphone it detects that and then it shows the landscapeguicontroller:
Code:
    landscapeguicontroller *neu =[[landscapeguicontroller alloc] initWithNibName:nil bundle:nil];
    [self presentModalViewController:neu animated:YES];
    [self dismissModalViewControllerAnimated:YES];

The Problem is that then the animation pushes the new window from the beyond side of the iphone up into the window.
In the Landscapeguicontroller,i have added to the the following lines:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

when i want go back to the highguicontroller i call:
[self dismissModalViewControllerAnimated:YES];

that all works , but just in the second animation i see the correct "rotation animation".
Have you got any suggestions?
So a short Problem description:
in the 1. animation from high to landscape, the landscape is pushed into the window
BUT in the 2. animation from landscape to high, the rotation looks like a real rotation...
i want the 1.animation look like the 2. animation
best regards
Ploetzeneder
Answer: To avoid  "The Problem is that then the animation pushes the new window from the beyond side of the iphone up into the window.", try setting the view controller's modalTransitionStyle property to one of the following, whatever you prefer:
typedef enum {
   UIModalTransitionStyleCoverVertical = 0,
   UIModalTransitionStyleFlipHorizontal,
   UIModalTransitionStyleCrossDissolve,
} UIModalTransitionStyle;
Also, if you want to avoid the animated rotation, you can set your shouldRotate... method to disallow other orientations, but then set up to receive notifications when the device physically changes orientations, and present your modal viewcontroller when in the appropriate orientation for it.  See Apple's "AlternateViews" sample code for an example of this.
The notifications reflect the physical orientation of the device, and you can receive them whether the interface is allowed to change or not. (You can look at the UIApplications's statusBarOrientation property to see what orientation the UI is in).
Answer: It sounds like you want the sequence to go like this:

Physically rotate the device from portrait to landscape
Animate the portrait view (highguicontroller) to landscape
Push the landscape view (landscapeguicontroller) up from the new "bottom" of the screen

If that's right, you'll need to have something like the following in your highguicontroller implementation:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
  return interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown;
}

This will take care of step 2 (it will rotate the portrait view to landscape in either direction).
Then you'll want something like this:
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
  if(fromInterfaceOrientation == UIInterfaceOrientationPortrait) {
    [self presentModalViewController:landscapeguicontroller animated:YES];
  }
  else {
    [self dismissModalViewControllerAnimated:YES];
  }
}

That should present the landscape view after the rotation animation is complete and then dismiss it after the device is rotated back to portrait.
Hope that helps!

Rotation Portrait Landscape with 2 XIB


"Have you had a breakfast" or "did you have a breakfast"?

Question: Which one is correct "have you had a breakfast" or "did you have a breakfast"? And should I use the 'a' s, is it necessary to use it?
Answer: Neither is correct!
The usual question is either:

Have you had breakfast (yet)?
  or
  Did you have breakfast - usually, but not necessarily, followed by a time reference - this morning?

However, one uses the indefinite article before an adjective preceding breakfast

Did you have a good/hearty/substantial breakfast this morning?
  Have you had a good breakfast in preparation for a hard day's work.


Deformation of a vector bundle and cocycles

Question: This question is motivated by the question Tangent Space to Moduli Space of Vector Bundles on Curve which is about the computation of first-order deformations of a vector bundle, A.K.A, the tangent space at a rational point of the moduli space of vector bundles over a curve. It is well known that the first order deformations of a vector bundle $E$ are given by the elements of $H^1(C,End(E))$, but I don't quite understand the proof. By definition, we have a covering $\{U_{i}\}$ of $C$ where $E$ trivializes, and in addition, we have transition maps
$$g_{ij}:U_{i}\cap U_{j}\rightarrow Gl(r)$$
satisfying the cocycle condition. And the big trick comes next where they said that the deformations of $E$ (vector bundles over $C_{\epsilon}$ being $\epsilon^2=0$ ) are given by transition functions of the form $g_{ij}(1+\epsilon a_{ij})$ with $a_{ij}\in \Gamma(U_{i}\cap U_{j}, \mathfrak{Gl}(r))$ being $\mathfrak{Gl}(r))$ the Lie algebra of $Gl(r)$. Can anybody explain it to me with patience this last part. I really want to understand it.
Comment: Intuitively, a deformation of the vector bundle would entail a 1-parameter family of vector bundles $E_t$ over $C$, such that $E_0 = E$. This would give rise to a family $g_{ij}(t) : U_{ij} \to GL_r$ of transition functions with $g_{ij}(0) = g_{ij}$. The deformation can be read off by taking derivative of the curve of transition functions at $t = 0$; $a_{ij} = g_{ij}'(0)$ is exactly that. This is a map from $U_{ij}$ which lands into the tangent space, i.e., Lie algebra $T_0 GL_r = \mathfrak{gl}_r$. The trick with $\varepsilon^2 = 0$ allows one to do this trick in the algebraic category.
Comment: Thank you for your response @BalarkaSen but I would like a rigorous proof of this fact, in order to achieve a better understanding.
Answer: Question: "Can anybody explain it to me with patience this last part. I really want to understand it."
Answer: If $C$ is a projective curve over a field $k$ and $E$ is a coherent $\mathcal{O}_C$-module, you may (following Serenesi "Deformations of algebraic schemes") define the Quot scheme $Q:=Quot^C_E$, parametrizing coherent quotients $f:E \rightarrow F$ of $E$.  Let $K:=ker(f)$. The tangent space of $Q$ at $(F,f)$ is given by the following formula:
$$T_{[f]}(Quot^C_E):=H^0(C, Hom_{\mathcal{O}_C}(K,F)).$$
The obstruction space $Ob_{[f]}(Quot^C_E)$ is given by the following formula:
$$Ob_{[f]}(Quot^C_E) \cong Ext^1_{\mathcal{O}_C}(K,F).$$
If $E$  and $F$ are locally trivial and of finite rank it follows $K$ is locally trivial of finite rank and
$$Ob_{[f]}(Quot^C_E) \cong Ext^1_{\mathcal{O}_C}(K,F) \cong Ext^1_{\mathcal{O}_C}(\mathcal{O}_C, K^*\otimes F) \cong $$
$$H^1(C, K^* \otimes F).$$
Hence if $E,F$ are of finite rank and locally trivial you get the tangent space
$$T_{[f]}(Quot^C_E):=H^0(C, K^* \otimes F)$$
and the obstruction space
$$Ob_{[f]}(Quot^C_E) \cong H^1(C, K^*\otimes F).$$
As I recall it: There is a detailed proof in the above mentioned book but it takes several pages. The book gives an introdution to the Hilbert and Quot schemes in the "language of schemes". Maybe this helps - a book is more reliable than online notes.
Note: In your case you should try to construct your moduli space $M_C$ using the quot-scheme. You will need a locally trivial (or coherent) sheaf $F$ on $C$ such that your vector bundles $[E]\in M_C$ are quotients of $F$. Then the above formula(s) give the tangent and obstruction space. If $E=K$ is finite rank locally trivial, it follows $E^*\otimes E \cong End_{\mathcal{O}_C}(E)$ hence
$$Ob_{[f]}(Quot^C_F)\cong H^1(C, E^*\otimes E) \cong H^1(C, End_{\mathcal{O}_C}(E)).$$
Hence you must construct a bundle $F$ and a quotient $f: F \rightarrow E$ with $ker(f)=E$.
Example: One choice is $F:=E \oplus E$. There is a canonical surjective map onto $E$ with kernel $E$. Hence
$$M_C := Quot^C_{E\oplus E}.$$
Any coherent sheaf $F\in Ext^1_{\mathcal{O}_C}(E,E)$ can be used.
Comment: But this is not what I have asked. I want to know what happens with the transition functions.
Comment: @SamanthaSmith - yes, the above construction is another type of construction that is more general. Still it may be useful to have several approaches - this is why  I wrote the post- you wanted to achieve a "better understanding".
Comment: Maybe I have expressed myself poorly @hm2020. I really appreciate your answer, and I understand it better due to the book of Sernesi, but I still don't understand where those transition functions arise.
Comment: @SamanthaSmith - You may use the Quot scheme $Quot^C_{E\oplus E}$. Then your formula follows from the book of Sernesi.


Can a werewolf from another faction bite you?

Question: My friend has joined me in ESO and has become a werewolf, however he's in the Dominion whereas I'm in the Pact so there's a conflict of territories. He offered to bite me to allow me to become a werewolf but we're not sure how we'll be able to if he can't enter Pact territory. Is there a way around this so I can accept the werewolf bite?
Comment: Haven't played the game since beta, but isn't there the huge PVP area where everyone can enter? Depending on who owns which areas there you guys could probably meet relativly savely.
Answer: Not playing the game anymore, but I guess my answer should be accurate. Please correct me if they changed it.
No, you can't be bitten by him
For biting another player, you will have to meet in "the one high level region" of your faction, where the Werewolf shrine is located. As players from other factions only meet in PvP areas, you both can't be in the same PvE area.
Comment: That is not entirely accurate. You can also be in the same pve area as a vet, but it will be different instances (unless you are really really lucky/unlucky).


Share a File on Server without giving rights to users such that the file cant be copied?

Question: I am using Windows 2003 server as OS, is there any option to give users only Read and Write access. I don't want users to copy the file or move the file or attach the file in any mail. As the file is an very confidential. Is there any way to do so??
Answer: If you have the ability to read and write you have the ability to make a copy.  In order to protect a document against unauthorized reproduction (but allow read /write access) you need to have a file format (like office file formats) that supports DRM and a DRM server.  Windows Rights management service provides that functionality.  You need a Windows RMS Client Access License (which you may already have depending on your CAL type) See Installing Windows Rights Management Services with Service Pack 2 Step-by-Step Guide
Comment: Even a DRM server is a false sense of security - if people can read the file then they can copy it no matter what.  You may as well either trust certain people and restrict copying through policy or hold the data on physically secured media with supervised access.
Comment: I suppose if you consider that you could take a photo of the screen then yes you could copy it or worse yet you could actually memorize the text.  By your logic the only way to secure any data is to shoot the users afterward, which in quite a few cases would also solve a few other problems, however the subsequent HR mess would render the solution unfeasable, no user is worth that much paperwork.


Weird sudo behavior on MacBook Pro

Question: I have a company MacBook Pro. I am sudoer and I can do anything that requires admin privileges when I'm connected to the company network. But I can't when I'm home. How is that possible?
Answer: This special behavior is probably related to the sudoers file.
By modifying this file in /private/etc/ one can restrict the sudoers to particular networks or single IP-addresses:
The common user privileges specs are as following:
<code># User privilege specification
root    ALL=(ALL) ALL
%admin  ALL=(ALL) ALL
        |    |    |command
        |    |as user
        | hosts
</code>
This means: the users of the group admin can sudo any command as any user ("Runas") from all networks.
By specifying a restricted host/network in the host alias specification earlier in the same file this may be changed:
<code># Host alias specification

Host_Alias      COMPNET = 172.17.0.0/255.255.0.0
</code>
Modifying the user privilege specifications to:
<code>root    ALL=(ALL) ALL
%admin  COMPNET=(ALL) ALL
</code>
doesn't allow you to execute sudo in your home network if the IP-address is not in the above range (e.g. your home network provides DHCP leases in the 192.168.0.0/24 range and none of the other interfaces have an IP in the above 172.17.0.0/255.255.0.0 network). Back in the company network (e.g. with a DHCP range 172.17.5.0/24) sudoing works again.
Comment: Don't edit it on your own. Set EDITOR and use `visudo` as root.
Comment: I have those privileges and can do sudo now. However, I still cannot install applications the usual way...
Comment: @Bob My answer is just one possible answer. You'd have to add additional informations to your question. How did you get back your `sudo` privileges?
Comment: by adding my name in sudoers under /private
Comment: @Bob can you post the original content of your sudoers flie? Or does it contain any secret data (like company network data, user groups etc.)? You may have to sanitize the file before posting it here!
Comment: @Bob As said your company admins may use other means than the sudoers file to restrict access.

Weird sudo behavior on MacBook Pro


Are there any bounties that you can only do once?

Question: I've noticed a few bounties that have been available multiple times, such as the 100 headshot kills bounty. I haven't seen any of the area-specific ones reappear, like the ones where you need to do 6 patrols on a certain planet. Are all bounties eventually available to redo, or are some only available once?
Answer: Yes, all bounties are repeatable and can reappear again. It just depends on what RNG chooses for that 24 hour period (It restocks at 4AM EST.). I'm not sure if they are different between platform, but I do know that everyone on the same platform gets to pick from the same bounties. Xb1 gets patrols and assassination targets pretty often.
Comment: Hm, yeah I'm not really sure how it works in terms of progression, but I do know that at "end-game" they are all the same because my friends and I all work together on the same bounties for the day. The bounty leads may be part of that progression as they are one of the "new" bounties that get added.
Comment: Everyone on the platform gets the exact same bounties? I thought the bounties that were available to me matched my level/progress: first there were Earth bounties, then moon ones, and now I have some for the other planets available. It's possible that I got all of these progressive bounties from "bounty lead" messages, but that begs another question: are the bounties you get from messages repeatable?
Comment: There is some difference based on what's available but sometimes it doesn't work. For example I got a mars patrol bounty waaaay before I could go there. There are also some bounty-exchange things that you get at your mailbox after certain story events.


does steam kills weed seeds in compost

Question: I have some compost material from a group of homes, if I wanted to sell them to organic farmers, will steam treating them kill all the weed seeds inside it?
Comment: It depends on the temperature that the compost reaches; Steam in an autoclave ( medical practice ) probably do it ; spraying some steam at a compost pile , little affect.
Comment: https://en.m.wikipedia.org/wiki/Soil_steam_sterilization
Comment: @Johannes_B, that's an answer you have provided link for, thanks!
Answer: The composting process should result in high temperatures (over 130 Fahrenheit) for at least 3 days in a row. If you achieve that, and maybe more days, then weed seeds should be killed by that process already. Commercial composters will lay out their compost in a small area like 10 square yrds and add water for a few days to cause germination of any seeds in the mix. If seeds start germinating then that has to be disclosed to the purchaser and some other method, like steaming it, I guess, should be used to fix the problem.

does steam kills weed seeds in compost


Safe to use a 16 amp motor on a 20 amp circuit with a 15 amp outlet?

Question: I have a 1.5 hp table saw motor rated at 115v/16amp. My garage has all 20 amp breakers but all outlets are 15 amp. Does the 15 amp outlet present a hazard if the wiring and circuit are all rated at 20 amps?
Comment: See https://diy.stackexchange.com/q/12115/42053
Answer: Just change out the receptacle
I bet your tablesaw has a 5-20 plug on it, which won't fit into a 5-15 receptacle. Since you have a 20A circuit, though, there's nothing wrong with having a 5-20T duplex receptacle on it, or even changing all the receptacles on the circuit to 5-20Ts from 5-15s.  This shouldn't be too tricky a job, as long as you turn off the breaker before you start (of course), change the receptacles one at a time, and note down how things were wired before you start unhooking them.  Also, if the existing receptacle is a 15A GFCI, it'll need to be replaced with a 20A GFCI, not a regular receptacle.
Comment: Don't forget to mention that OP needs to check whether the wiring is 12-gauge or better.
Comment: Or the GFCI could be moved upstream and this outlet powered off it LOAD terminals.
Comment: @Harper-ReinstateMonica True. But the simplest thing, by far, if the existing receptacle is a 15A GFCI, is to replace with a 20A GFCI. Replacing upstream will actually cost $1 more (because you are then replacing 15A GFCI with 20A plain **and** 15A plain with 15A GFCI) and can lead to the LINE/LOAD confusion. So a single straight replacement makes the most sense. Of course, we're all just guessing as to whether the existing receptacle has GFCI anyway.
Comment: @manassehkatz no no, no, you'd just *move* the GFCI you already own, to the upstream location.
Comment: @Harper-ReinstateMonica Oops. You're right (as usual!). But it still raises the issue of getting LINE/LOAD messed up.
Comment: Changing a receptacle isn't really "biting the bullet" - it's a two dollar part and a three minute job.
Answer: All of this is safe, except you cannot plug in the table saw.
What, you say? The table saw has a common-as-dirt NEMA 5-15 plug? How did that get there? That right there is the fly in the ointment.  No, that is not safe. A 16A motor needs a NEMA 5-20 recep. (unless the motor has some very peculiar characteristics in which it's allowed to use a smaller plug AND breaker, but you do a specialized  rain dance with Code to see if that is so).
However, there is nothing wrong with plugging a mix of 15A and 20A receps into a 20A branch circuit.
Make sure that if this recep is GFCI, that you either replace in-kind or move the GFCI recep to an upstream location and feed this location off its LOAD terminals.  15A Receps are supposed to be rated for 20A passthru, and that includes GFCI receps.
Answer: Short answer is yes.  If your table saw motor gets pinned down and is pulling > 15 amps, you've exceeded the specs for the outlet and it will get nice and warm.  This causes the contacts to degrade and eventually introduce a good fire hazard.  The longer you run it over its rated amperage the more likely you are to start a fire.
I'd replace the socket with a 15/20 socket like so:  https://bit.ly/34SZTvs
My table saw has similar ratings, and to be honest as long as you don't put a ton of load on the blade the current will stay less than 15 amps.  I've been running mine on a 15amp socket and breaker for 8 years.  Have blown the breaker a couple of times when a piece got stuck, but my house hasn't burned down yet.


How to solve this IQ test puzzle with arrows and pied squares?

Question: What is correct answer for this IQ task and why?
Comment: Is this from Raven's Progressive Matrices or somewhere else?
Comment: @JoeZ., I have no idea what are you talking about:)
Comment: [Raven's Progressive Matrices](http://en.wikipedia.org/wiki/Raven%27s_Progressive_Matrices) is the prototypical example of problems like this one. If the puzzle is a well-known example, it would be prudent to list its source. Otherwise, if you're posting it as a challenge (and as such, posting its source would ruin it), please tag it as such.
Comment: @JoeZ., i met this puzzle in an IQ test. I have added the tags.
Answer: The answer is:

 F

I googled and found the test this task is taken from: http://www.iqtest.dk/testEnglish.swf
If I answer 1-10 questions correctly and 38 H, I get IQ 92.
If I answer 1-10 questions correctly and 38 F, I get IQ 93.
So I conclude that correct answer is F.

How I understand this puzzle:
In the corners (cells: 11,13,31,33) we have some objects. In the middle edges (12,21,23,32) we have operators on neighbouring two objects. The centre cell (22) is simply do not used here [this opinion agrees with tasks 4 and 9 at the same test, where it is used similarly].
Let's look on (12) operator (one arrow), it leads to simple vertical stretching of object.
Let's look on (21) operator (two arrows), it leads to simple swap of object colours.
Now we are looking on (23) and (32). (23), by our assumption, should swap colours of (13), creating the object from varian H, plus some additional operation, since (23) is different from (13). (32), by our assumption, should stretch (31), making variant H from it, plus some additional operation.
What are these additional operations? Since they make the same object from the same object (H) that must be the same. Looking on possible answers we see that all differences between objects are: size, swap of the colours, angle. We have notations for first two differences, so additional operation should be rotation.
We see that (23) is rotated respectively to (21), by 45 degree clockwise. (32) is rotated respectively to (12) by 45 degree clockwise. So most probably both additional operations means rotation by 45 degree clockwise. This means that the right variant for (33) is F.

What I do not like about this solution:

One arrow and two arrows means completely different things. It is counter intuitive. And though double arrow associated with swap, no doubts, it is also associated with stretching.
Arrows in (12) and (21) have different orientation, and this have no influence on the objects, meanwhile orientation of (32) and (23) is important. [The orientation of arrows can be explained by the fact that they also plays role of objects for meta operation, but this is lousy argument, based on "how would author think creating this puzzle" - the orientations of arrows when they play role operators still do not agree with each other.]

I hope, someone else will find even better explanation, without mentioned two drawbacks.
Comment: or you are overcomplicating things and that is what is tested with this question (whether you can apply occams razor to this)
Comment: @ratchetfreak, agreed. But one can apply the same argument for defence of my answer: Occams razor says "do not introduce additional entities", therefore all objects in the puzzle should be connected together and follow only one rule, rather then several independent rules.
Comment: @ratchetfreak, you appeared to be partially right. I overcomplicated (22) symbol, it just marks unused place.
Comment: I wouldn't mind the fact that a single-headed arrow meant something different from a two-headed arrow.  On the other hand, I see no basis for assuming that a 45 degree rotation of the arrow should imply that the shape should be rotated 45-degrees the same direction, after applying the effect that would be implied if the arrow were in the earlier-shown orientation.
Comment: @supercat 45-degree is consequence that you need to get from (13) and (31) the same figure.
Comment: @klm123: Would not "any single-headed arrow causes vertical expansion; any double-headed arrow causes a 180-degree rotation" work just as consistently (but yield "h" rather than "f")?
Comment: @supercat, yes. but with this logic, if you neglect differences in figures, we also can say "anything on this puzzle causes answer A".
Comment: @klm123: I don't follow.  The only way one could get answer "A" would be if the diagonal double arrow condenses the figure vertically, which would be inconsistent with any other behavior observed for the double arrow.  Nothing guarantees that all differences between *operational symbols* are significant, and indeed many such puzzles require identifying which aspects are relevant and which are not.  Further, I see no basis for assuming that rotation of a symbol implies corresponding rotation in the same direction of the result of the operator.
Comment: Posted an answer where the orientation of the arrows lead me to figure out which size of the box was being effected. Still think double arrow means flip colors, however this didn't seem counter intuitive to me at all.
Comment: Though unlikely, if we use the arrows as a kind of operator on the shapes, then from top right down, then across to the other side, then down again, by peforming the actions of the 2 arrow in the middle to the upper right object, you get the lower left object (flip and lengthen vs colors are fliped and square became a long rectangle). Doing the same thing but vertically for upper left to lower right gets varied results depending on what you interpret the arrows as doing.
Answer: H.
Various categories of symbol appear on alternate rows and columns:
Odd row, odd column - rectangles shaded in two colours, with diagonal dividing line.
Odd row, even column - single headed arrows
Even row, odd column - double headed arrows
Even row, even column - cross
Each category of symbol appears to have its own type of transformation:
Odd row, odd column - height increases moving right, which half is shaded swaps moving down (or 180 degree rotation moving down)
Odd row, even column - 45 degree rotation clockwise moving down
Even row, odd column - 45 degree rotation clockwise moving right
Even row, even column - ?  (only one member)
In the absence of any obvious common rule for all symbols, I conclude that each set follows its own rules.  Thus the answer is H (column 3 = tall, row 3 = top left half black).
I did wonder if the arrows represented transformations for the squares on either side - the arrow in row 1 column 2 could represent a height increase.  The double headed arrows suggest a flip to me but would have to represent a rotation for this to work.  But this system breaks down with row 3 column 2 - there are no answers which have been stretched along a diagonal (which would give a parallelogram).
Comment: The supposedly correct answer assumes that a 45-degree rotation of the arrow should imply a 45-degree rotation in the same direction for the resulting square, but there are no examples which show this behavior and would not consider it particularly logical (with many kinds of operation, for example, rotating the operator by a certain amount would rotate the result by twice that amount, or would--as you suggest--change the axis about which adjustment is performed.  Very poorly-designed puzzle.
Answer: Like bmj, I also get H as the answer. However, my logic is much more straightforward:

We see:

Upper Left  $\rightarrow$  Upper Right $\Rightarrow$ Rectangle $\rightarrow$  Square
Upper Left  $\rightarrow$  Lower Left $\Rightarrow$ Invert colors

Therefore:

Lower Left  $\rightarrow$  Lower Right $\Rightarrow$ Rectangle $\rightarrow$  Square
Upper Right $\rightarrow$  Lower Right $\Rightarrow$ Invert colors

Resulting in a color-inverted square.

The arrows and $\times$ are just distractions.
Answer: The answer is

 F

Though I get it slightly differently. I got this answer before looking at the other answers, just in an attempt to solve it myself.
The first thing I noticed is that the arrows are different lengths. The exact length of the arrow is also the exact size of the shape it is referring to.
For example, the one at the top stretches the box to exactly that length.
I also came to the conclusion that a double arrow means to flip colors.
I realized that the [2,1] arrow did not change the size of the box only the colors, this does not mean that the double arrow ONLY changes colors though, it just means it ALSO changes colors. The arrow length is the exact size as the box in [1,1] and in [3,1], which means the size didn't need to change from that arrow.
However, since the box at [3,1] stayed the same size we can assume that the arrow at [2,1] only effects the horizontal lines (aka the top and the bottom lines). The arrow at [1,2] only effects the vertical lines (aka the lines on the size of the box).
Using this logic of it decided the exact length of the box based on arrows, and that the arrows at [1,2] and [3,2] are effecting the side walls and the arrows as [2,1] and [2,3] are effecting the top and bottom sides. We can assume right away it must be a diamond shape, since that is the length of the arrows and how they are shaped.
After that I just simply replaced the bottom and top of the box at [1,3] with the length of lines from [2,3], then fliped the colors. Then we combined that with the sides of the box of [3,1] being replaced with the arrows from [3,2] and when we combine we indeed get F.
Here is an image I did in paint to show the combining and replacing of sides:

You can see that if you combine those 2 pictures together that is what you end up with.
The most important part I saw that was overlooked was that the arrows were always the exact length and direction of the side of the box that was being effected. This is how I came to the conclusion of the answer for this question.
Comment: The main (and huge) disadvantage about your theory (in my opinion) that you "combine", that means that you do a lot of assumption and have no way to double check them. In this logic operations [3,2] and [2,3] are not dependent, that means one can assign any operations to them and ALWAYS get some result at [3,3] - you simply can't check whether your approach is wrong or not, since it always leads to some result.


How to get passphrase from a private key?

Question: I have private key. How can I get passphrase for my bitcoin address.
Comment: What do you mean by "passphrase for your bitcoin address"? Addresses are not encrypted or password protected. Do you mean you have an encrypted copy of your private key (e.g. in an encrypted backup)? Or do you have a private key and you just want the corresponding address?
Answer: Assuming you have a symmetrically encrypted copy of your private key, where the encryption key was derived from a passphrase, you would be trying to perform a known-plaintext attack. However, it should not be possible in polynomial time for a proper AES implementation, so I'm afraid you're out of luck.


Why is "100% Japan-made Solid Capacitor" a selling point?

Question: I'm seeing a lot of high end Motherboards including 100% Japan made caps.  I've been out of the PC world for quite some time, why is this a feature?  What is so special about these caps?
Comment: Of course, in addition to everything else, one needs to seriously question whether you can BELIEVE that the caps are Japan-made.
Answer: Well, there's two factors in play here, both to do with the dreaded capacitor plague that killed so many computers of the naughties stone dead.
Basically, electrolytic capacitors are cheap, have great capacitance per unit volume but are often kind of lacking in other respects, such as ESR. Some capacitors, made by Taiwanese companies used a flawed formula that ended up with those capacitors failing catastrophically. This was a specific formula, used over a period, and modern capacitors are likely to use fixed formulas that are more reliable.
The solid capacitors are a newer design using organic semiconductors or OSCON. They couple low ESR (which is good) and a wider temperature stability range (since the solid capacitors can't/won't freeze or boil). They're significantly better than the garden variety capacitors in most respects - to compare, the maximum temperature the average liquid  capacitor can handle is about 85-95 degrees, while the solid caps handle in excess of a hundred. They also have better characteristics in general, but I doubt anything that most users would notice.
They don't fail the same way (catastrophic bursting) as electrolytics - though I can't find any literature on this outside this website which suggests they can silently fail by moisture infiltration resulting in increasing ESR, but that they've never seen it before
The fact that they are japanese? Not made by the lowest bidder, and often by the companies that developed the technology. These capacitors are made elsewhere too, and have been around a while.
At the end of the day, many motherboards that come with these capacitors also have other features to improve reliability, and arn't made of parts that are picked mainly for cheapness.
Comment: +1 for addressing the capacitor plague... since for most people that are concerned with such information, knowing that the capacitors are **not** made in Taiwan is an important point.
Comment: Looks like solid caps [can and do burst](http://superuser.com/a/86841/117590).
Comment: Apparently its a [known issue](http://www.badcaps.net/forum/printthread.php?t=5919) with that particular series. I guess they can malf up *anything* if they (don't) try hard enough
Answer: It seems Taiwanese and Chinese sources of capacitors may have been the ones involved in the capacitor plague.  I'm not sure if only capacitors from those countries were the ones prematurely failing, but that could be a basis for the marketing claim.
Comment: +1 for addressing the capacitor plague... since for most people that are concerned with such information, knowing that the capacitors are **not** made in Taiwan is an important point.
Answer: The "solid" capacitors (mainly produced in Japan, but not necessarily Japanese) are purported to be of higher quality, with more refined electrolyte and with better sealing capacity than standard capacitors. This means that when (slightly) abused, or growing old, they are less prone to explode and/or leak electrolyte. In marketspeech, "less prone" becomes then "they won't leak. Ever!". Electrolyte-less capacitors will of course not leak as they've nothing that can leak -- but you can blow them just as easy as ordinary capacitors. There's no such thing as magic, alas.
In motherboards my opinion is that this not very relevant, for high-end motherboards are built with higher tolerances and quality control, and they won't experience capacitor leak for a very long time; and low-end motherboards will be bought (or should be bought) with a short life expectancy anyway. Seeing "japanese solid capacitor" touted as a sell point would make me think that they've been included in the project as marketing sugar, nothing more.
Comment: -1 no mention whatsoever of the capacitor plague... and considering how many capacitors I replaced on the motherboards used in Dell GX270s over the years (several local school systems worth) that came out of that Capacitor plague... let's just say it's not marketing sugar to know the caps aren't made in Taiwan.


Looking for a hook to add attachment information to the media library tab

Question: I would like to be able to determine if an image has been attached to a post by looking at the collapsed viewmedia library tab. Is there's a hook I can use to add that data to this view of the Media Libray tab?
I've included a mock-up of what I'd like the media library to look like.

Is it possible to amend the current media library tab or would I have to create a custom tab to get this functionality?
Answer: As far as I know, and I've researched the topic a lot, there's no hook to do this. Neither an easy jQuery.
And looking at WordPress 3.5 beta-1, all previous hacks and hooks may be obsolete soon or just after soon...


LED Lightbar as a turn signal

Question: I changed my turn signals to LED light bars the other day. They are completely legal, but the issue I'm having is I can't use my parking lights and turn signals. The bulb that I took out and replaced with the light bar had two filaments, I want the turn signal to work as follows: When the parking lights are on and I apply the right turn signal, I want the right light bar to flash while the left one stays on. And Vise Versa. Except when I do this now the light bar dims a very small amount while the parking light and the turn signal is applied. My Question would be, what do I need to do to get the light bar instead of dimming a little bit to turn off and on while my parking lights are on. I'm not sure if this little explanation made sense, but you can ask if you need more info. Thanks!
Comment: is it possible , this can never work without details?
Comment: I can't find anyone who has done it before. But i know that in the rear of the vehicle some cars have brake lights or running lights that are LED that can also act as turn signals, so I am assuming I can do it in the front.
Comment: If the second filament of the bulb you took out was acting as a side lamp, it needs to go bright/dim/bright as the original did. To do this you need either a light bar that has this function built in (they have 3 wires), or find a controller that will do that, and some of these light bars won't respond well to the PWM that is used for the dimming if they've got their own drive electronics built in (they'll interact with the PWM and flicker).
Comment: hmmm okay, where could I find one of those controllers? Do you know what they're called?
Comment: "*They are completely legal ...*" Why do you say that? And where? (You have no location in your user profile and it can be a help in location specific questions.)
Comment: most people would say its illegal because they are light bars on the front of a car, but I talk to inspectors and I made them legal, and I live in PA
Answer: This can be done with three relays, single-pole, changeover type.

simulate this circuit – Schematic created using CircuitLab
Figure 1. Parking light and turn signals.
How it works:

With parking lights off the blue wire is energised. If either turn signal is switched on RLY2 or 3 will click on and off illuminating the lightbar on that side when the normally open (NO) contact is closed.
With parking lights on the orange wire is energised. Both lightbars will turn on. If either turn signal is switched on RLY2 or 3 will click on and off disconnecting the lightbar on that side when the normally closed (NC) contact is opened.

simulate this circuit
Figure 2. Timing diagram.
Note: It is important that the turn signal changes state immediately the switch is moved. This avoids the half-second or so delay that would occur if the turn signal logic is not inverted when the lights are on. This design achieves that requirement. 0.5 s at 72 kph is a travelling distance of 10 m when one car is stationary and 20 m if both are moving towards each other at that speed. That half-second can make a big difference in avoiding a crash.

LED Lightbar as a turn signal


Which is a better framework for project management : PMI or Prince ? or there is a better alternative?

Question: I had done PMP certification about 2010 but I was not satisfied. There are huge gaps between practices on ground and PMI. There are many outputs that PMI suggests which are rarely a written record .
There are quite a few inputs and tools that are like motherhood statements e.g. meetings is suggested as a tool!
Comment: You are looking for a methodology.  PMBoK is not a methodology.  The gaps you have identified are the gaps between a framework and method.
Comment: Welcome to the site, but I fear this question is intrinsically subjective/opinion related. [Help] explains why subjective questions are difficult for SE sites.
Answer: What's better is what fits the specifics of the particular project you are working with.
There are a bunch of project management methodologies and frameworks to choose from. Projects vary in scope, requirements, target audience, domain in which they run, constraints differ, etc., meaning that "the better" methodology to use will also differ. How you manage building a small e-commerce website to sell clothes will differ from how NASA will build their software, for example.
You have to account for the following:

In theory, theory and practice are the same. In practice, they are not - Benjamin Brewster

Project management techniques, methodologies and frameworks, give you the theory: a set of rules, practices, principles, guidelines and tools that have been shown to work in various contexts. But they can't give you a set of steps to follow that guarantee success on any project, because as I mentioned, all projects differ in some way or another.
So as a Project Manager, you need to invest in knowledge, skills, tools, and techniques to apply on project activities to meet the specific project requirements and constraints. It's then with experience that you start to recognize when something is "better" to use, given the specifics of the situation you find yourself in.


Is it possible to apply to grad school in the US with only subject GRE, not general GRE?

Question: I have 3.94 GPA on 4.0 scale but I've really trouble in terms of time to prepare for both tests general and subject.
I prefer to prepare for only math subject test.
Could I apply to schools with only the math subject test, or is the general test a nearly-universal requirement?
Comment: It doesn't take that long to be reasonably prepared for the General. Mostly you just need to familiarize yourself with the format.
Answer: Every university is different. The GRE is less used than in the past, but some universities still ask for it or even require it. COVID, along with a general realization of its limitations has resulted in some schools dropping it.
So, you need to explore the specific requirements of any university you plan on applying to. But you need to do that in any case. Good luck.


Is it worth getting a 144hz monitor when FPS games go only 80fps?

Question: So I've been playing an FPS game which gets around 70~80fps usually. Upgrading my graphics cards is not an option now, so I'm willing to buy a monitor with 144hz, but I'm not sure if it would make any difference because of the fps I'm getting now. From your experience, would it be worth in terms of gaming performance?
Comment: What is the refresh rate of your current monitor? If you're getting 80 FPS on a 60 hz monitor then you're missing frames that could have been shown on a better monitor.
Answer: Well, it definitely won't increase your FPS :)
Seriously, for gaming performance it technically doesn't matter. The only difference is the amount of frames that are shown by the monitor, not the amount of frames rendered and frames you can do inputs on. If you do choose to get a new monitor, get one with FreeSync and GSync, since if your GPU will output less frames than the monitor supports, it can tear, and that looks really ugly (as if your OC is a bit too high), although this can be regulated through MAXIMUM RENDERED FRAMES in most games. Also look for the monitor response time if you want/ if your current monitor's is high(=slow).
I recommend not getting a new monitor in your case though,(unless you really want for other reasons),
instead save that money for a new GPU.
Answer: As long as you get the same resolution, nothing will change in performance.
Though, if you match your graphics card with the monitor: AMD GPU + monitor with Freesync Premium / NVIDIA GPU + monitor with G-Sync, it can actually make your gameplay seem smoother/more pleasurable to your eyes, in games where your FPS may drop. Thanks to "low frame rate compensation (LFC)", your monitor will adjust its refresh rate to match your frame rate, so no tearing occurs.


What is the purpose of datasync project in weblogic project?

Question: What is the purpose of datasync project in weblogic project?
What is *.evt, *.req, *.usr files?
Answer: There is a good explanation on the docs about datasync. Basically it is a webapp used to copy data across from one weblogic server instance (actually from it's database) to another. Example - copying all the data from production to test instances.
*.evt, *.req, *.usr files are XML format files used in Weblogic Portal applications.
EVT files are event files which can be triggered at any user interaction with the Portal. This is mainly used for capturing user behaviour and firing any rules, an example is a
campaign fired for specific users.
REQ files define the HttpRequest attributes
USR files define UserProfile attributes


private or unknown calls on call logs

Question: I have noticed that when I receive a call from a private or unknown number, the notification does not appear on my call log list. How can I get a private or unknown number call I receive to appear on my calling log list?
Answer: Well, it may not register into the log because there is nothing to register. There is little, if any, data you can collect from a private call log.
The other thing is possibly your priority mode on your android. That could cause interference. Maybe. Not for sure on the last part but it is worth a shot. Anyways, just my 2 cents.

private or unknown calls on call logs


Postulate of a-priori probabilities

Question: In Statistical Mechanics, we often postulate that for an isolated system, the phase-space density of all accessible microstates (i.e all microstates consistent with the energy) is the same. This is equivalent to assuming that the system is ergodic. This postulate leads us to the assertion that at any given time, the system is most likely to be found in that macrostate which has the maximum number of consistent microstates, and from then on, we calculate the entropy for this macrostate and get the fundamental relation for entropy, and hence, other thermodynamic quantities.
My question now is: Is this assumption of equal a-priori probabilities too strong to obtain the second assertion? In other words, can we not say that the macrostate with the maximum number of microstates is the observed thermodynamic state, while being non-committal as to whether indeed they are all equally probable or not? Or am I losing some information by not considering their probability distribution (maybe, say fluctuations)?
Answer: First, although it is common in some textbooks, I don't think it is a good thing to necessarily relate the equiprobability postulate to ergodicity.
Second, what this postulate enables is to estimate the probability distribution for the macrovariable you want to look at. You can of course look at the most probable value for this macrostate and this will correspond to a "thermodynamic interpretation" of what you can expect to observe.
However, in statistical mechanics, what you can expect is not the most probable value but rather the average value and they need not be the same.
Moreover, you may want more than simply the average value; you can also want to predict what is the free energy difference between one value of the macrostate and another in some kind of transformation in your sytem and for this you are in trouble if you don't try to get the probabilities right.
Answer: Correct entropy in the analysis of complex systems: What is the consequence of rejecting the postulate of equal A priori probabilities?
Delas, N.
doi: 10.15587/1729-4061.2015.47332
Comment: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).

Postulate of a-priori probabilities


Trying to send some ETH to a Wallet

Question: I have an Exodus Wallet with some USDC in it. When I try to exchange them or send them to another wallet, it says that I need to add some ETH to make it possible (0.0043 ETH). I check on Binance and the gas fee for the transaction is 15$ which seems too big. I was wondering if you have any tips on how to deposit a lower amount, without paying too much for the transfer fee?. Thank you and sorry for the bad English!
Answer: The transfer fee depends on the used gas price. You are free to set any gas price you want, for your transaction, but if you want your transaction processed in a reasonable timeframe you have to set a reasonable gas price for it.
The current gas prices and their respective costs can be seen for example at https://etherscan.io/gastracker . An average ERC20 token transfer costs currently $8.
Centralized exchanges, such as Binance, will include extra fees in the transfers. But you don't really have options if you want to use them - you have to pay their fees.
Comment: Do you know any other exchange where you can buy ETH and they don't charge that much for the gas price?
Comment: That's not possible. Eth transactions cost what they cost - there's no simple way around it for any transaction in the mainnet.

Trying to send some ETH to a Wallet


Original Xbox performance

Question: So, I have been playing King Kong on the original Xbox and it runs both amazing and badly. If I'm in a cave or a small area, it runs smooth, but if it's raining, or I'm in an open area or so on, it drops to like 10 frames a sec. Is it just because it's an old console, is it a problem specific to the game, or is there something I can do to boost the performance?
Answer: This has to do likely with the video chipset on the original XBOX. Like any machine, really, the amount of work that the GPU has to do goes up if there is more going on, on screen. When it is raining, there is alot of movement and pixels that have to be calculated and drawn. In an open area, there is far more clipping and 3D calculations going on. In a cave or some limited area, the amount of math involved is low.

Original Xbox performance


Load Excel data into SQL Server using SSIS without Creating tables in the target

Question: I am new to SSIS and am not sure if this is possible to upload Excel data into SQL Server without creating table schema, where the Job automatically creates the table schema according to the source file? I used to do this using SAP Data Integrator with Template table component and I am not sure if there is a similar functionality in SSIS
Answer: There is no capability in SSIS to interpret the structure from the source file and create the table schema.  You can create tables as part of the SSIS control flow, but the data flows that load the data are very fussy about knowing the source and target structure at design time.  In other words, it doesn't handle dynamic structures very well.
Comment: I guess a script task is the only way. But SSIS does have the ability through writing code.


Are there any services that will update Google Latitude from Yahoo Fire Eagle?

Question: I'm looking for a web application that will update my Google Latitude location every time I update my Yahoo Fire Eagle location. I checked the Fire Eagle application gallery and didn't find anything that would do this.
Answer: IFTTT
For anything that requires cross-app integration, I use IFTTT which stand for IF This, Then That. It allows you to create recipes which are basically a set of actions consisting of a Trigger and an Action (to be taken on Trigger) for Channels which are apps that it supports (like Facebook or Gmail or WordPress or Date and Time, you get the idea).
As for your particular case, they don't have a Channel for Google Latitude of FireEagle yet. You can contact them, though.

FireEagle -> FourSquare
Okay, so I thought about it and came upon the idea of using a middleman. You can use FireCheckIn to integrate FireEagle and FourSquare. That was easy.

FourSquare -> Latitude
While IFTTT does have a for FourSquare, it doesn't for Latitude, so it can't be of any help. After Googling, I found this post which tells you how to connect the two.
If that doesn't work, you can use IFTTT, though in a different way. You can use the FourSquare Channel to output the check-ins to a text file in Dropbox or a message in Evernote, from where you can search for integration into Latitude.

List of Channels
While isn't relevant to your question, I am proud that I came up with the code to extract this within 20 minutes considering I'm a newbie to JS:-
For a full list of IFTTT's currently supported channel, here you go:-

App.net
bitly
Blogger
Box
Boxcar
Buffer
BuzzFeed
Craigslist
Date & Time
Delicious
Diigo
Dropbox
Email
Evernote
Facebook
Facebook Pages
Feed
ffffound!
Flickr
Foursquare
Gmail
Google Calendar
Google Drive
Google Reader
Google Talk
HootSuite
IFTTT
Instagram
Instapaper
Last.fm
LinkedIn
Phone Call
Pinboard
Pocket
Pushover
Salesforce Chatter
SMS
SoundCloud
Stocks
Storify
Svpply
Tumblr
Twitter
Vimeo
Weather
WeMo Motion
WeMo Switch
WordPress
Yammer
YouTube
Zootool
Comment: Yeah, I should have mentioned that I already looked there. Unfortunately, even though they have some things like Foursquare on  there, it doesn't do anything with locations yet.
Comment: @pidge You can request them to do so, though. They've been adding a lot of new stuff lately. If there's no other answer, can you still accept mine, please?
Comment: OK, _now_ I should definitely get the bounty :)
Comment: Well, I should have checked before I awarded the bounty, but I think your directions go the wrong way (from Latitude to Fire Eagle). And FireCheckIn doesn't exist any more. 'A' for effort though?
Comment: @pidge Well, the repo's still there on GitHub ( https://github.com/johl/FireCheckIn ), but sorry if I wasn;t of any help. I don't really use any of the services. Why can't you just use one?


Why is Google Search Console getting X-Robots-Tag noindex?

Question: As can be safely inferred from the question, I'm trying to get Google to index my site.
I'm using Wordpress 5.9 served by nginx (1.13.12), with SEOPress (5.6 up-to-date).
I let the wizard guide me for the settings and created a sitemap that I registered with Google Search Console - as advised.
I let Google do its work and came back later to check, and found that every page exposed in my sitemap returns a noindex meta (X-Robots-Tag with User-Agent 'Googlebot for smartphones').
I did uncheck the "discourage search engines..." checkbox in Wordpress Reading settings.
I also did reset opcache, and I don't have a wp cache plugin (I don't have that much traffic so far).
And when I load the pages in a browser or with curl the X-Robots-Tag is set to none...
$ curl -I https://www.alchimie-web.com
HTTP/1.1 200 OK
Server: nginx/1.13.12
Date: Tue, 26 Apr 2022 15:07:44 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive
X-Powered-By: PHP/7.3.16
Set-Cookie: __wpdm_client=ce7f05b428fa7da70dc3dd9192fdc0a5; secure; HttpOnly
Link: <https://www.alchimie-web.com/wp-json/>; rel="https://api.w.org/"
Link: <https://www.alchimie-web.com/wp-json/wp/v2/pages/7>; rel="alternate"; type="application/json"
Link: <https://www.alchimie-web.com/>; rel=shortlink
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
X-Robots-Tag: none
X-Download-Options: noopen
X-Permitted-Cross-Domain-Policies: none

even with various User-Agents to try and reproduce what the Googlebot reads :
$ curl -A 'Googlebot/2.1 (+http://www.google.com/bot.html)' -I https://www.alchimie-web.com

or
curl -A 'Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)' -I https://www.alchimie-web.com

or
curl -A 'Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.93 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)' -I https://www.alchimie-web.com

The site never returns a X-Robots-Tag: noindex...
Any hint on what I'm doing wrong ?
Should I use another SEO plugin ? (though I read that the same problem sometimes occurs with Yoast...)
Answer: I have a nginx directive that set X-Robots-Tag to none for every page. I thought it was some kind of null value for the header...
Now that I took some time to RTFM, I learned that none means both noindex and nofollow... So it wouldn't let the SEO plugin do its job.
Now that I removed it, it certainly works better.


"All men are mortal, Socrates is a man, therefore, Socrates is mortal" original quote

Question: Where the syllogism "All men are mortal / Socrates is a man / Therefore, Socrates is mortal" first appeared?
Comment: Did you notice that later in the article, making it part of the conclusion, the author uses the expression "identical to Socrates"? I can say that the expression is redundant because "The only thing identical to Socrates is Socrates." Law of Identity, A is A, Aristotle.
Answer: Comment on similar example.
The example is not from Aristotle.
Categorical propositions with singular terms are used in Medieval logic; see Peter of Spain's Summulae logicales (XIII century):

I,8 Propositio singularis est illa [...], ut "Sortes currit" [Socrates runs].

Into this textbook we can find many examples of them in the discussion of loci and entimema [V,3], bt it seems to me that there is no occurrence of the specific example of syllogism.
According to: Joseph Maria Bochenski, A History of Formal Logic (1961, or.ed.1956), page 232:

A first widening of the Aristotelian syllogistic consists in the
admission of singular terms and premisses. William of Ockham (c.1287–1347) already knows of the substitution that was to become classic [Summa Logicae, III 1,3;36rb]:

Every man is an animal;

Socrates is a man;

Therefore, Socrates is an animal.

Here the minor premiss is singular. But Ockham also allows singular propositions as major premisses.

The earliest occurrence I've found is: Sextus Empiricus, Outlines of Pyrrhonism (Pyrrhōneioi hypotypōseis), also translated as: Outlines of Scepticism, Book II, 164 [Many thanks to David Wheeler]:

Socrates is human.

Everything human is an animal.

Therefore, Socrates is an animal.
Answer: Per David A. Wheeler's article "The Origin of All Men are Mortal" (which elsewhere cites this page!)

The earliest document I can find with this specific example is from 1843, specifically A System of logic: Ratiocinative and Inductive, Presenting a Connected View of the Principles of Evidence and the Methods of Scientific Investigation by John Stuart Mill, 1843, Book II Chapter 3 page 245.

One can indeed see the quote
<code>2. It must be granted that in every syllogism, considered as an argument
to prove the conclusion, there is a petitio principii. When we say,

All men are mortal
Socrates is a man
  therefore
Socrates is mortal ;

it is unanswerably urged by the adversaries of the syllogistic theory,
that the proposition, Socrates is mortal, is presupposed in the more
general assumption, All men are mortal:
</code>
in the Internet Archive's copy of Mill's System of Logic.


How do i export/import MX Google Map entries

Question: I need to transfer aprox 700 MX googlemap entries from old db to new. I have tried ajw-export/Datagrab but it does not transfer the geodata.
Comment: i would probably just merge the data in MySQL with SequelPro. e.g. setup the fields and entries and the copy over the data from the old table to the correct field_id's in channel_data
Comment: Looking for a datagrab based solution here too, I think the problem is that MX Google Map isn't DataGrab aware... or is it the other way around... :?
Answer: You could use Google Maps for EE to do this, but you would need a .csv to do it. It comes with a geocoder/import utility that is really robust and will work for almost all data files. I know it's not for MX Google Maps, but this could save you quite a bit of time by not having to roll out a custom solution.
https://objectivehtml.com/google-maps


Fretting string is muted

Question: I bought a ukulele recently and have tuned it using a tuner.But , I have a doubt.When I hold the 3rd fret 4th string for the C chord I am unable to hear the sound of the same string i.e it is muted , the rest 3 strings are audible and clear. Likewise, for D chord , I heard only 1 string and the rest 3 are muted, for B chord , I hear no sound since all 4 strings are muted. How can I overcome this, please let me know
Just for info  : It is a concert GCEA Ukulele .
Comment: You are pressing down *in between* the fretwires, aren't you? Pressing *on top* of the wires will inevitably mute notes.
Comment: First you need to play each fret of each string separately, to establish if any are muted by themselves. If so, it may be that the bridge is too low.
Comment: So you are muting strings when you try to play a chord?
Comment: I was guessing the same thing about fretting technique. When you're told to play the "3rd fret," you want to press just *behind* the metal ridge. (If you press, for instance, just barely ahead of the 2nd metal ridge, then the string might buzz.) Try a quick youtube search for beginning ukulele technique and you'll get lots of good pointers.
Answer: The first step is to check to see what is causing the muting. Actually, this is just a good exercise in general to clean up/troubleshoot one's playing technique.
Preliminary checks: First, play all the open strings, one at a time. Doesn't matter how you pick or pluck, just do them all individually. Do they all sound cleanly? If not, your ukulele has a problem. Be sure you have tuned the strings to the correct octave (the G-string should be high or low depending on what type of G-string is being used); if tuned an octave too low, the string will be very loose and bend too easily (if an entire octave too high, it probably will have snapped already!). More than likely, the open strings all sound cleanly, so proceed to the next check.
C chord: Start by fretting the 3rd fret of the A string. Pick it by itself. Does that sound clean? If it is muted, then either your instrument is set up poorly or you will need to work on fretting technique. Comments pointed out that the fretting finger should press down between two fretwires, ideally just behind the wire that the string will contact. Do not allow the edge of your finger to spill over the lip of the fret, as this will begin to deaden/muffle the string and dirty up the sound. You may need to press down with more force, particularly if your strings sit high above your fretboard. Check to make sure that your fretting hand is only touching the strings that it is fretting; press straight downwards on the 3rd fret to avoid accidentally brushing against an adjacent string and muting it by mistake. The thumb can be on the back of the neck for support, or the palm of the hand can cradle the neck. Both work for this chord.
If it is not muted, then strum the entire chord. Since the C chord only uses that one finger, if the strum sounds muted now, then it is likely that your strumming technique is muffling the string (or your good fretting technique is going out the window as soon as you strum). Make sure that no part of your strumming hand is resting on any of the strings, and you may need to strum harder/faster across the strings to get all the notes to sound cleanly. Think of strumming through the strings, not stopping afterwards.
If the strumming worked, then it should work with enough practice to become consistent at it. Now on to the next one.
D chord: First, I will troubleshoot the 3-finger grip for the D chord. Start by fretting only the 2nd fret of the G string with the index finger. Does this note sound cleanly? If so, move on to fretting only the 2nd fret of the C string (middle finger). Next, only the 2nd fret of the E string with the ring finger. If all of those can be fretted and picked cleanly, try adding two of them at a time. Then all three, and be sure to take enough time to position the fingers correctly. Make sure each finger can feel the string in the center of the pad before pressing down to play it. You may need to angle the fingers slightly diagonally to fit the fingers in the same horizontal fretspace - rotate the wrist so that the fingers point away from the headstock rather than perfectly perpendicular to the strings. If the fingers feel cramped, one option is to substitute the pinky finger for one of the three notes. Since the pinky is usually the smallest finger, this may help with spacing. Another option is to switch to a larger ukulele, since small ukuleles make claustrophobic fingerings tougher. It may also be wise to consider learning the one-finger partial barre D chord grip if this one is simply not working out. Once this all works cleanly, strum it and it should be good.
For the one-finger version, you need to take one finger and lay it flat along the 2nd fret. Then concentrate the pressure onto the G-, C-, and E-string area of the fretboard, and try to lift the finger off of the A string as much as possible. If done correctly, the three strings will all be sounding cleanly and the open string will not be muffled by the fretting hand. This can be tough for some players, but some find it to be easier than the three-finger version. Do whichever is more consistent for you. You will also need to press down pretty hard, which means it will be easiest if the thumb of the fretting hand is pressing from behind on the back of the neck close to the area directly below the fretting finger.
There is another alternative that I have occasionally seen players use for the D-chord, which is using the thumb of the fretting hand to wrap around the back of the neck and reach over to barre the G-, C-, and E-strings from the other side of the fretboard. I'm not a huge fan of this personally, but it does work for some people. While you may catch some flak from purists for thumb-fretting, it does produce the correct chord, so it may be worth an investigation if nothing else works for you. Not many ukulele chords benefit from the use of the thumb, but this is a case where being able to reach over does avoid needing to collapse the knuckle. I still recommend learning the other two methods if possible because the thumb grip makes for slower chord transitions (the entire hand has to move when going from thumb grips to a chord that needs the thumb on the back of the neck).
B chord: Go through the same process as the D chord by starting with single notes, then combinations of the rest, until all of the notes at once will sound cleanly. Take your time. If issues arise, make sure that the thumb is right below the fingers on the back of the neck for this chord so that squeezing the neck is easy. Keep the fingers perpendicular to the strings for this chord grip regardless of whether you are barreing the second fret or collapsing the knuckle like in the D chord. If you aren't sure how hard to press, press as hard as you can and see if that works. If that works, then you need to be pressing harder than before. If not, something else is the issue. Make sure that the fingers are pressing down as vertically as possible, and avoid letting the fingers on the G and C strings lay horizontally over the E and A strings. They may be causing some buzzing or muting.

The problem seems to be happening on the fretting part, which means you will likely need to practice fretting notes cleanly. Make sure you are pressing down vertically and with the tip of the finger, and right in between the two fretwires. There are lots of ukulele resources available online that would be very helpful, especially for beginners, and you may even have an instructor or friend who can help position the fingers correctly for you to demonstrate.

Fretting string is muted


How to calculate the state debounce time for an analog voltage input pin?

Question: An analog voltage input pin (AVP) of an ECU has an input voltage range of 0 to 10V and a Filter Frequency Limit of 330Hz.
The input signal voltage (ISV) coming from a sensor to the AVP has a range between 0.5V and 5V. Using the ISV, the software should produce a digital state signal (DSS) in time domain with 0 and 1 states. So, two upper and lower thresholds are set - upper 4V and lower 2V. If the ISV is above 4V, then the DSS has the state 1 and if below 2V, then the state 0.
But the direct conversion of ISV into DSS gives a bouncing signal. So, a debounce time is to be calculated to have the states of the DSS without transients. Do you have an idea how the state debounce time can be calculated?
Comment: What are all these confusing abbreviattions that cause me to re-read what you write several times. AVP ISV DSS are what I refer to. Try plain ordinary English.
Comment: I thought the abbreviations would make it easier to read.
Comment: The thresholds look to me like "hysteresis." If so, you should NOT be doing a "direct conversion" and if you did so, then of course you'd get a bouncing signal with noise present. Solve the hysteresis problem (by understanding what it is and how to implement it using your input voltage measurement.) Then discuss here your remaining bounce problem once that is solved.
Answer: You don't calculate a bounce time, you measure it. Operate the switch many times, record the digital signals, and observe how long the bouncing goes on for. From that, you need to estimate what the likely longest time bouncing will be going on for, twice as long as you've ever seen in many trials might be a reasonable estimate. With that estimate, you can apply debounce in your software.
Comment: Thanks. So, I should try simulate the different possible analog voltage signal with the analog pin? i'll try this.
Comment: But what should I do with the Filter Frequency Limit?
Comment: How about you draw a schematic of what you have?


When did MCMC become commonplace?

Question: Does anyone know around what year MCMC became commonplace (i.e., a popular method for Bayesian inference)? A link to the number of published MCMC (journal) articles over time would be especially helpful.
Comment: I doubt that anyone could provide a single year. It's more reasonable to consider the diffusion of MCMC over time. It originated in the 50s with the Metropolis-Hastings algorithm but did not see wide adoption and use until the advent of relatively inexpensive computational power beginning in the 80s. To the best of my knowledge the first uses were in Bayesian facial recognition technologies of that time. Secondarily, beginning in the 90s, MCMC use spread to other fields such as economics & marketing with the Chicago school. Check out Gilks & Spiegelhalter's 1996 *Practical MCMC*.
Comment: @Peter Mine came before either answer; hover your mouse over the word "yesterday" on each (or anything indicating an elapsed time since posting) to see the precise UTC time. I think the answer you indicate is a good partial answer but the question would still admit several completely different takes with no good basis to choose between them.
Comment: This question is vague and calls for opinion (there's no accepted definition of commonplace or popular). It admits any number of arguably correct answers.
Comment: @Glen_b I think the answer given below is excellent. Do you disagree? Or did you write your comment before that answer?  (Both just say 'yesterday').
Answer: This paper by Christian (Xi'an) Robert and George Casella provides a nice summary of the history of MCMC. From the paper (emphasis is mine).

What can be reasonably seen as the first MCMC algorithm is what we now call the Metropolis algorithm, published by Metropolis et al. (1953). It emanates from the same group of scientists who produced the Monte Carlo method, namely, the research scientists of Los Alamos, mostly physicists working on mathematical physics and the atomic bomb.

The Metropolis algorithm was later generalized by Hastings (1970) and his student Peskun (1973,1981)

Although somewhat removed from statistical inference in the classical sense and based on earlier techniques used in Statistical Physics, the landmark paper by Geman and Geman (1984) brought Gibbs sampling into the arena of statistical application. This paper is also responsible for the name Gibbs sampling

In particular, Geman and Geman (1984) influenced Gelfand and Smith (1990) to write a paper that is the genuine starting point for an intensive use of MCMC methods by the main-stream statistical community. It sparked new inter-est in Bayesian methods, statistical computing, algorithms and stochastic processes through the use of computing algorithms such as the Gibbs sampler and the Metropolis–Hastings algorithm.

Interestingly, the earlier paper by Tanner and Wong (1987) had essentially the same ingredients as Gelfand and Smith (1990), namely, the fact that simulating from the conditional distributions is sufficient to asymptotically simulate from the joint.This paper was considered important enough to be a discussion paper in the Journal of the American Statistical Association, but its impact was somehow limited, compared with Gelfand and Smith (1990).

I couldn't find the number of journal articles published over time, but here is a Google Ngram plot for the number of mentions over time. It more or less agrees with the notion that MCMC became commonplace after the 1990 paper of Gelfand and Smith.

Reference
Robert, Christian, and George Casella. "A short history of Markov chain Monte Carlo: Subjective recollections from incomplete data." Statistical Science (2011): 102-115.
Comment: Thank you! I would deem 1990 to be the most important date in the history of MCMC, as four papers by Alan Gelfand and Adrian Smith appeared that very year in top Statistics journals and made the concept of using Markov chains for simulation suddenly mainstream. I remember attending a talk by Adrian Smith in June 1989 in Seherbrooke (PQ) where he demonstrated the universality of the idea by showing a slide with a few lines of (Fortran?) code.
Answer: The excellent answer by knrumsey gives some history on the progression of important academic work in MCMC.  One other aspect worth examining is the development of software to facilitate MCMC by the ordinary user.  Statistical methods are often used mostly by specialists until they are implemented in software that allows the ordinary user to implement them without programming.  For example, the software BUGS had its first release in 1997.  That does not appear to have changed the growth trajectory in the N-Grams plot, but it may have been an influence in bringing the method into common usage among those users who found it intimidating to program their own routines.
Comment: hmmm, BUGS was presented at the [Valencia Bayesian Statistics conference in 1991.](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwilwvqBhJDlAhXeVBUIHY_dBPsQFjAAegQIBRAB&url=https%3A%2F%2Ftrove.nla.gov.au%2Fwork%2F34833375&usg=AOvVaw2i4d6AC2ZWe5IzCpWYWulv)
Comment: Huh, there is a small twist in the line for MCMC right around 1997.
Comment: Well-spotted - not sure if it would be a big enough change to be statistically significant, but noted anyway.
Comment: Visually estimating, if the slope before 1997 were maintained, we would have seen something like 0.000015 % around 2004 (but the actual value is close to 0.0000225 %). That's a 50% increase. But I suppose the numbers are too small anyway.
Comment: Perhaps you're right - good eyes!

When did MCMC become commonplace?