How to approach learning long complex piano scores without the instrument?

Question: How to approach learning long complex piano scores without the instrument? I use musical analysis, pattern recognition, hearing to midi slowed, rewriting difficult passages, playing parts on guitar instead of piano,  but still it is not fast to remember the long score precise enough to play like a pro. Mechanistic memory is most reliable and unsubstitutable, however I want to remember scores from a one or two reading attempts. Are there any other ideas which I don`t know? Thank you.
Comment: I'm assuming you can read words more easily than music? Could you recite an entire short story after just reading it three or four times? Me neither. Why would music be different?
Comment: @11684 The asker specified "long, complex piano scores", which is why I used a short story as an analogy rather than a haiku. They also specified "without the instrument". Imagine not being able to say the words you are reading or even imagine how they sound in your head. Seems like a very difficult task.
Comment: Thanks, but I see no new ideas, as far as I know, top players can learn 30-page sonates from reading it in a chair with a bottle of whiskey and a cigar, then playing it on public perfectly amazing without dumb billion-time repetitions like giftless hard-working semi-deaf children (I am so too?). Never too late to learn to do things properly.
Comment: Don't forget the pros who can memorise large scores, put in many years of work since childhood to reach that level... we would need **at least** a similar effort.
Comment: there are many-many employed pros with 40 years of playing and academic education who learn score in 6 month instead of 3 hours, people are different in abilities, and surely in stamina to work hard, no talent appears without work, of course
Comment: Can you add to your question what *you* define as long and complex? What is an example of what you can memorize quickly now?
Answer: The great pianist Walter Gieseking advocated using visualization techniques.

One form of visualization (advocated by the pianist Walter Gieseking) is to study the score of the peice until you know it so well that you could sit down with a blank sheet of manuscript paper and write it out from memory. No simple undertaking! Gieseking even advised doing this before you ever try the piece out on your instrument, but that might be going a little too far. However, if you try doing this experiment with a simple piece like Lagrima, I think you will notice that you are seeing in your head what your fingers are doing, translating that into notes, and then writing it down. This is s sign that you are relying on muscle memory when you play a piece, and this kind of memorization is notoriously unreliable. [From Visualization, Solfege, and other "Aides Memoire"]

The problem with relying on muscle memory is that if you suddenly have a lapse of concentration you can literally lose your place. If you are visualizing the score you are "seeing" it in your mind, and can go on as if you were sight-reading. From what you said, it sounds like this is a method you haven't tried.
Comment: Funny, I have the exact opposite experience with muscle memory. My.. "normal"? memory is unreliable - my fingers know what they heck they are doing, though. They should, they've done it at least 100 times before I ever hit the stage! I'm a little confused about having a lapse in concentration while using muscle memory. When my fingers do the playing, I'm not concentrating at all.
Comment: @Todd: It's precisely because my mind is free to wander that I sometimes lose my place if I'm relying on muscle memory alone. I remember getting totally "wandered" in the middle movement of Bach's Italian Concerto, with all its meanderings that seem to go on forever.
Comment: Also, I'm talking about memory for the architecture. Sure, your muscles (more properly, your *ganglia*)  remember the fingerings in a tough passage. But they don't  remember if you're supposed to repeat *da capo* or move on to the bridge and so forth. *That* is how you get lost.
Answer: I can't offer a particular method, but you may find it interesting that Glenn Gould apparently could practice "mentally." I recall him saying this in an interview. Also, this Wikipedia page has some references about it.
https://en.wikipedia.org/wiki/Glenn_Gould#Gould_the_pianist
See the part near "It seems that Gould was able to practice mentally without access to an instrument..."
I don't know if any resources tell how Gould did this. Maybe he visualized the score, the keyboard, colors? Who knows.


How are horses' stats generated?

Question: Are horses in Zelda in an area the same for all players or are they randomly generated? If it's random, do horses around the area change their stats when you reload a save?
Comment: Horse stats are completely randomized but there are areas where it's likelier to find 'better' randomized stats.
Comment: @BlueBarren That is interesting that horse quality is dependent on area, do you have a source for that? Might make a good answer.
Comment: @Malco the reason I didn't write it as an answer is because I can't remember the source, sorry.
Answer: This IGN guide on horses does a pretty good job explaining how horse stats are generated. In essence, it's random (aside from a handful of unique horses that have set stats, such as Epona). You also won't be able to know an individual horse's stats until you register them, though.

The stats of the horse may improve if you venture into dangerous areas - but you'll never know how good your horse is until you register them. Their stats can be as low as one star or as high as four in any category.

A good indicator of how good a horse's stats will be is their coat color. From the above guide:

Wild horses come in a variety of colors, such as three different tones of brown, tan, black, grey and blue. While one-colored horses tend to be the better ones (higher stats), those with spots normally have lower stats, with an exception of the tan and one of the brown coated horses, of which those without spots have lower stats as well.

(emphasis mine)

To answer whether reloading a save will regenerate the horses in an area, it appears that, yes, this is the case. From this Reddit thread:

The two spots I've found with these horses are around the giant horse, and on top of a plateau between the canyon with the forgotten temple, and the horse stable east of it. You can save before going after a horse, and reload to change their colors. Once you have one with the color you want (the best horses have pure solid color. Either pure black, pure brown, or pure blue is best, with any color mane), go after it and soothe it.
Comment: Just to add my observation, once you entered that area (Dueling Peaks stable area for example), it seems that reloading it does not randomize the horses' color on that area. Always seem to find a group of horses with same set of color variation. Not sure about the stats though.

How are horses' stats generated?


How to handle generator polynomial in CRC if given in (x+1) (x^3+ x^2 +1) form?

Question: I am trying to find the frame check sequence in cyclic redundancy check(CRC). Given that the generator polynomial is $\ g(x)= (x+1)(x^3 + x^2 + 1)$. Let's say the data sequence is $\ 10110001$.
In this case, $\ g(x) = x^4+x^3+x+x^3+x^2+1 $ after multiplying. But how do I handle 2 $\ x^3 $ terms? Is it okay to convert it into binary without worrying about it? For example, $\ 1 1111$ and continue with the division?
Answer: When computing CRC, we are working over the field of two elements. In this field, 2=0. Therefore
$$
(x+1)(x^3+x^2+1) = x^4+x^2+x+1.
$$


Should the sun appear very low in the horizon if its path is always between the two tropics?

Question: If the sun never rises above the tropic of cancer and never goes bellow (southern) of the tropic of capricorn then it seems that it should appear to the observer lower and lower in the horizon for as we move north. But from what I have seen this is not what I have observed traveling in northern and southern countries.
Am I not remembering right or is my expectation wrong?
Answer: Your explanation is correct, so you are not remembering correctly. The farther north you go, the lower the sun is to the horizon at noon.
Of course it depends on how far north you go. If you only travel 5° farther north in latitude, then the sun is only 5° lower in the sky. 5° is a "long" ways to travel on the earth, but in the sky 5° lower is not that noticeable.
Comment: @Jim, because the Sun *always* appears low on the horizon at sunrise and sunset.  If you want a meaningful comparison of elevations, you need to pick a time to do the comparison, and noon has the advantage of being the time of maximum elevation.
Comment: @Jim: From what latitudes (or city, state, country) have you made your observation? From knowing the latitude, the maximum altitude of the sun (at noon) on the first day of summer would be 90-latitude+23.5, and on the first day of winter the maximum altitude would be 90-latitude-23.5. From that, you can decide whether the Sun is low enough in the sky to be visible when looking horizontally or not. (I think our peripheral vision in the up-and-down direction is more limited than in the side-to-side direction.) Both formula for northern hemisphere and angle is above southern horizon.
Comment: Why do you specify "at noon"? I don't remember not having to look upwards to see the sun. Shouldn't I see the sun without even looking up? (meaning turning my head upwards)
Comment: @Mark: Ah ok makes sense. But still I don't understand why the observer should need to raise the head upwards instead of looking straight in the horizon keeping the straight head.
Comment: @JohnHoltz: I was thinking that I should not need to raise my chin up to see the sun over the tropics. But then it occurred to me that it might be due to the earth's curvature
Comment: @JohnHoltz: What exacty is 23.5 in `90-latitude+23.5`? That's tropic of cancer?
Comment: @Jim. Yes, 23.5 degrees is the angle between the Earth's axis and the plane of the Earth's orbit. So the maximum latitude that the Sun is above(Tropic of Cancer) is 23.5 degrees N. The minimum latitude that the Sun is above (Tropic of Capricorn) is 23.5 degrees S.
Answer: I am not sure how your observations are so mistaken, but this is exactly what happens. In fact at high latitudes, there will be parts of the year when the sun never rises above the horizon. Try going north of the Arctic Circle in winter and you'll see what I mean.
All I can think is that either you have not travelled very far north or south, or you have travelled to northern or southern countries only in their summer and not paid attention to the sun's apparent movement.
I grew up at 59 degrees North, and one of the very obvious signs of the seasons is how low the sun is to the horizon for the winter months. This makes for long sunsets while the sun moves along the horizon.
Conversely, at the equator, the sun goes overhead, and sunsets are rapid, as it comes down near perpendicularly to the horizon.
Have a look at this ohio-state.edu lecture page for some useful info on apparent motion of celestial bodies, like:
Comment: This diagram helps. I think in my mind I was thinking that the observer is perpendicular to the earth and didn't take the curvature into account. That's why I was thinking that I should not need to raise my chin to see the sun


Why do my clothes not save in GTA V online?

Question: Everything was working fine. I was able to change clothes anytime and it would save. Now, all of a sudden, every time I die or change servers my clothes reset to the outfit I had purchased at the start. I would love to create and keep my own look, any ideas why this is happening?
Answer: I also often experienced the same problem and did look into it as although it never causes too much of a hassle to simply change them back, it can be boring after so many times.
Unfortunately I found there is no way of permanently keeping the same clothes on as to make the game more realistic, Rockstar incorporated the idea that over time your characters change clothes when unattended as they would in the real world. My ONLY option for you is to select the clothes you wish to wear online in a store rather than in your home wardrobe, I believe this improves how often this occurs and is fairly easy to deal with as whilst online, all clothes are available from the same store.
Hope this helps, enjoy your killing sprees.
Comment: Not a problem, happy to help! please feel free to inform me if this method still hasn't solved the problem, i'll do my best to help!
Comment: Hmm it seems to still not save unfortunatly. Its a shame haha!
Comment: My only other option to ask you is whether you are saving your game manually before you leave the session or go offline or whether you just leave it to the nearest autosave, this is honestly the only other option I could recommend that may solve this problem :/


Edit Whatsapp contact name in Samsung Galaxy S3 Neo?

Question: I wrongly saved one of my friend's name. Later renamed it with original name but when I searched contacts in WhatsApp I saw his name is still old one. I can't find a way to change name. I tried to edit via mobile contacts, but edit button in WhatsApp contact is disable. How to change WhatsApp contact that name in Samsung Galaxy S3 Neo?

Screenshots (click images for larger variants)
Answer: This may work :

Save your friend's number (copy & paste into a note taking app or write it on paper or just remember it).
Delete your friend's number.
Add new contact with the name you want and enter your friends number.
Comment: +1 Nice idea. I didn't think in this simple way :) I changed his whatsapp contacts name now :) but my doubt is why can't we change the name without deleting the contact?
Answer: WhatsApp seems to create a read-only version of the contact on many phones, so if simply changing the contact's name in your contacts app doesn't work, you might have to:

Delete the contact
Create a new one with the updated name.
Answer: Can't it be done by synchronisation of contact over whatsapp contact..
I mean editing contact in phone or sim card and sync to whatsapp then whatsapp replace the old contact and shows the new one.
Answer: You can follow these steps:

Rename the contact in your phone book and save.
Go to Settings > Account > whatsapp > sync now (or any similar option)

Most likely, your contact is not synced after you renamed!
Answer: It is to be done from inside Whatsapp and is simple.
1. Open Whatsapp
2. Tap Add Contact icon at the right bottom
3. Select New Contact
4. Select the choice of phone or SIM
5. Enter the Name
6. Enter the phone number
7. Save.


What is the CAD equivalent of OGC?

Question: The GIS industry has the OGC. What standards does CAD software have?
Answer: They are industry driven and dictated by your customers requirements, and deliverable requirements should be outlined in a contract.  I am sure your state DOT has a CAD/microstation specification on their website available to the public (assuming your in the states). If you are in the UK there is the AEC https://aecuk.wordpress.com/
There is also this: The United States National CAD Standard   enter link description here or this http://www.gsa.gov/portal/content/104697
Basically the answer is there is not one and it varies with organizations and industries.
Answer: It is surely the Open Design Alliance (ODA). Their product is called Teigha:

Designed by the ODA, Teigha® is available on all major operating systems. It supports the use of C++, .NET, and ActiveX interfaces and allows the exchange of data through .dwg, .dgn, .stl and .pdf files.

(Early on it was called OpenDWG but some private company got all lawyerly and put a stop to that.)

What is the CAD equivalent of OGC?


How do I run a remote node on windows (so I can connect mobile wallets to my own node)

Question: I couldn't find a detailed answer specifically for Windows users.  What is the simplest way to get a Windows 10 full node able to accept a connection from a mobile wallet so I can connect to a node I am in control of?
Answer: I extracted the Monero files to monero folder in C:
Right click on monerod and create a shortcut.
Right click on monerod.exe -shortcut and open "properties"
In the "target" field put in C:\monero\monerod.exe --rpc-bind-ip 192.168.1.100 --confirm-external-bind --restricted-rpc
In your router you will need to forward ports 18080 and 18081 to the IP of your machine running monerod.
I am unsure if there are any benefits to setting a password.
In addition, I made a task in task scheduler to start monerod at bootup (with the same options --rpc-bind-ip 192.168.1.100 --confirm-external-bind --restricted-rpc), and set my PC bios to automatically boot in case of power outage, this way its always running.
Comment: Find your WAN IP (ipchicken.com) and you can add it to your mobile wallet (cakewallet or monerujo) remote node list and use port 18081.


Lying in Court in the UK

Question: A defendant provable lied in court. We had no right of reply to prove the lies were false. Nothing has been done afterwards. He was found guilty, but received a very light sentence probably based on these lies. Is this normal?
Answer:
Is this normal?

Pretty much.
Witnesses lie in court all the time (in my experience, defendants, law enforcement officers and medical doctors are the most likely to lie).
Dealing with a witness who lies in court under oath effectively is one of the most challenging tasks lawyers face. It is an inherently challenging hurdle to proving or defending a case.
The facts as presented in court often differ in some material way from reality. It is a pretty tough thing to accurately measure, but my gut estimate would be that this happens in a least 30%-40% of cases that produce contested trials, although not infrequently, a judge or jury will not find the false testimony to be credible. On the other hand, it isn't at all uncommon (probably at least 10% of the time) for a judge or jury to believe the liars to be telling the truth, and to find the people who are telling the truth to be less credible.
There is absolute immunity from civil liability for lying in court testimony, although it could, in theory, give rise to contempt of court sanctions from the judge in some circumstances, or to a prosecution for perjury.
But, perjury prosecutions are, in practice, very rare, and a good share of them arise from false statements made in documents under oath, rather than from courtroom testimony. There is probably less than 1 perjury prosecution per 1000 provable lies made under oath in courtroom testimony on material issues that end up influencing the outcome in a case.
I totally sympathize with how frustrating this situation is having been there in cases that I am litigating many, many times. But, in short, life isn't fair.
Comment: @AtWitsEnd Generally speaking, the decisions on what evidence to present in a criminal case are made by the Crown attorneys and the defense attorney. Law enforcement has no say in that and the judge has only very limited control of that.
Comment: In the case of officers, mostly lies about what they witnessed in criminal cases and civil rights cases. In the case of doctors pretty much across the board from what patients told them, to what happened in a procedure, to financial and business matters, not just in malpractice cases or cases targeted at their finances, but in criminal and civil cases involving others who they have treated. My theory on doctors is that their professional ethos believes that "white lies" (e.g. misrepresentations re how long someone has to live) can have placebo effects and that lying for the greater good is OK.
Comment: When you say that officers and doctors are some of the most likely to lie, I can't help but wonder: what kind of lies are you thinking of?
Answer: It would probably depend on the importance of the case.
For example, lying about a car parking offence is not exactly a crime that deserves a great deal of scrutiny whereas lying about the use of an algorithm that affects the lives of millions say in insurance or banking deserves a lot more scrutiny.
This is one reason for example the European Parliament has legislated for transparency in the use of algorithms (GDPR).
In fact Mark Zuckerberg was for questioning in front of the members of the EU Parliament this year in spring as reported by Gizmodo, here is a sample of questions he was asked by Belgiums Guy Verhofstadt (paraphrased for clarity):

Are you telling the truth when you say that you are applying the GDPR privacy standards? Because there are already indications that you are violating the regulations.
Article 82 of GDPR gives the ability of compensation for users who have their rights violated. Will you compensate European Facebook
  users when you violate GDPR and what will be the level of compensation?
Will you cooperate with European authorities, open your books and let us see whether Facebook is a monopoly?
How will you be remembered: as one of the three big internet giants along with Steve Jobs and Bill Gates who have enriched our world, or as the genius who created a digital monster that is destroying our democracy and society?

And Germany's Udo Bullmann:

Are you ready to comply with GDPR regulations within the next three days?
How can you explain that the number of false accounts on Facebook is on the rise?
What are you doing to target particularly sophisticated fake accounts, specifically when it comes to political manipulation?
Are you ready to guarantee that upcoming European elections will be free from manipulation from foreign and hostile powers? How can you adapt your business model to make this guarantee?

And Germany's Manfred Weber:

Is Cambridge Analytica an isolated phenomena? Can you guarantee that another scandal won't happen in three, six or nine months time?
Did you personally make the decision in 2015 not to notify users about the loss of their data to Cambridge Analytica? And why was the decision made not to notify them?
Is there an alternative to Facebooks service in Europe today?
Would you consider your company a monopoly?
I think it is time to discuss breaking up Facebook, can you convince me not to do so?

Gizmodo didn't report on the answers by Zuckerberg to these questions. They merely reported that his answers boiled down to 'Facebook needs to do better! And we are!'
They do report that:

The most intense moment came right as Zuckerberg was wrapping up. Britains Syed Kamall reminded the CEO he hadn't addressed concerns about 'shadow profiles' that Facebook builds around non-users data.
Zuckerberg tried to explain that Facebook has announced a clear history tool that will let all users wipe out basic browsing history data. He explained that the company keeps tabs on non-users to make sure that they aren't scraping data and to monitor 'how people use their data'.
Kamall interrupted to ask how a non-user can stop their data being transferred to Facebooks system. To which he responded curtly, "on the security side we think it's important that we protect people in our community", before turning to his counsel and changing the subject.

I guess he's not used to being interrupted. Getting the scrutiny right on this is important as it affects the lives - on the last count - of two billion people. Sometimes numbers matter.
Comment: What does this have to do with the expectation of the majority of actual court cases?.
Comment: @Nij: Did you read the first two paragraphs? There I was pointing out that the legal mind has to decide where the most important cases are in terms of the over all influence in society. Hence, small-minded disputes over car parking fines and rows by neighbours over the size and height of fence - in the larger scheme of things - aren't so important - taking into account how much the plaintiff and defendant might have invested in their small-minded dispute. So we should under 'majority' not by majority but by major.
Comment: @Nij: Thats why I used the example of Zuckerberg facing a grilling in front of the EU Parliament. Privacy, misinformation and political manipulation are a *major* issue right now and they affect a *majority*. This is why Zuckerberg was asked to come in front of the EU Parliament. It's noticeable he declined to attend a session of questions at the UK parliament - which merely shows that Zuckerberg can't afford to ignore the EU whereas he can with the UK.
Comment: @Nij: I could have used as an example the recent revelations about RBS uncovered by the US prosecutors. No doubt they lied there. Otherwise why did it take ten years to reveal what had been talked about freely where no-one could listen? Those transcripts could have been made available ten years ago right in the middle of the crisis - after all, they were recorded then. It took ten years to reveal the truth behind the lies. But since I've used RBS in a another answer I thought I'd use a different example here - one that is of contemporary value.

Lying in Court in the UK


How far can you safely drill into 100mm thick brick for expansion plugs

Question: I'm mounting a rafter support for a lean-to at the side of my house (45mm x 120mm wood beam). I know that the bricks are 100mm thick, so I'm wondering what length of expansion plugs (rawl plugs) I can use. I don't want to drill right through the brick obviously but am wondering how far I can go?
Comment: I am not sure what you mean by lean-to.  If the rafters go all the way to the ground, I wouldn't worry too much about it because you're not relying on the fasteners to bear the weight of the ledger or prevent the ledger from pulling away from the wall.  If it's a shed roof, it may be necessary to drill all the way through and anchor to the frame of the house for safety.
Comment: The rafters would go onto another beam held up with fence posts. I digress... I really just want to know how far you can safely drill into a brick without any risk of damaging/cracking the other side as I want to avoid letting water into the insulation cavity of the house. e.g. for 100m thick brick, can you drill 90mm, or 75 etc?
Comment: 100mm is fairly thick. I don't think you need to go more than 70mm to get the support you need since you'll be putting quite a few in. Since you are drilling you'll probably not crack the brick. Just slow down as you get to the other side. Brick is fairly soft, if not cement brick, and a carbide tipped bit whether hammer or not will go through it.
Comment: The biggest issue might be the expansion plug cracking the brick -- don't over-tighten.
Answer: I think 75% of the brick should be fine.. normally there is a "blow out" of the brick within 1cm of reaching the other side... but this is really dependent on the type of brick (cement, clay, etc), moisture contnet, age of brick, diameter of hole and strength of the hammer action of the drill
If it were me, I would drill to about half way, then add some water to the hole and start to reduce my force on the hammer drill in order to slow the drilling speed. -- do not attempt to drill if you have an SDS type drill since the hammer action is not dependent on your applied pressure.
once the plugs are in place, you should have no issue hand tigtening the plug. just dont over-tighten


My Dog Growls When I Try to Pick Her Up

Question: My nine-month old English Boodle is very sweet and playful. She's never shown signs of aggression towards me or my family, or any other dogs - sometimes she tries to play with the cat, but usually gets smacked in the nose. I have noticed that when I go to pick her up, sometimes she growls at me. I immediately let go of her and back up. I'm not really sure what to do, she's not a mean dog and has never bitten anyone. She still acts like a puppy and is very friendly, but I'm still worried.
Answer: Most people only know a growl as a sign of aggression, but it can also be a verbal expression of displeasure, pain or apprehension.
First you should check your own body language. Are your legs straight and your torso bend down at the waist? Then you are towering over your dog which is a very aggressive gesture in dog body language. Her growl is just her answer to your aggression.
You should always bend your knees and keep your torso mostly upright to get down to her eye level. This way you avoid sending aggressive signals.
If that doesn't change the situation, picking her up might cause her pain. That could be either you pinching her or her back, ribs or joints hurting. You should support her weight with one hand between her front legs, holding her rib cage, and the other hand offering a platform for her hind legs to stand/sit on.
If you cannot find the cause of her pain, it's a good idea to get her checked by a vet.

My Dog Growls When I Try to Pick Her Up


Best SELECT syntax performance with 5 parameter

Question: i trying to select a table which have a million records using a Stored Proc.
The Stored Proc have a 5 parameter.
Which is has the best performance
Query 1:
SELECT * FROM Table1
WHERE Column1 like '%'+ @param1 +'%' AND
Column2 like '%'+ @param2 +'%' AND
Column3 like '%'+ @param3 +'%' AND
Column4 like '%'+ @param4 +'%' AND
Column5 like '%'+ @param5 +'%' AND

Note: I am using this because the result of LIKE with empty ('') param is the same as not using the param.
SELECT * FROM Table1
WHERE Column1 like '%'+ @param1 +'%'

is have the same result as
SELECT * FROM Table1

is the value of @param1 is empty ('')
Query 2:
IF @param1 = '' SELECT @param1 = null
IF @param2 = '' SELECT @param2 = null
IF @param3 = '' SELECT @param3 = null
IF @param4 = '' SELECT @param4 = null
IF @param5 = '' SELECT @param5 = null

IF @param1 is not null and @param2 is null and @param3 is null @param4 is null and @param5 is null
BEGIN
  SELECT * FROM Table1
  WHERE Column1 like '%'+ @param1 +'%'
END

and continue till all possibilities is covered.
Which is has the best performance?
The meaning of best is, has a efficient I/O and procession time
Thank you in advance

UPDATE
I've tried RADAR solution and i compared it with my first query using Actual Execution Plan
so it's the result:
Result from Query 1 (me)

Result from Query 2 (RADAR)

I don't know how to read it, please help me
Thanks again
Comment: Using `like '%' will prevent the use of index, so I suggest you stay away from this unless absolutely necessary.
Comment: because data in records is all in varchar. so it's necessary isn't it?
Comment: Depends, if you want to return string with `@param1` as substring then `like '%' + @param1 '%' is necessary. However, if you want only the exact match, better use `=`.
Comment: @user1008497, I just simplied your second approach with less code and made readable, both execution plans are same, try with some parameters as empty string and see the plan
Answer: Second approach is better, you can simplify it with or condition based on parameter value
 SELECT * FROM Table1
 WHERE (@param1 ='' or Column1 like '%'+ @param1 +'%' )
 AND
 (@param2 ='' or Column2 like '%'+ @param2 +'%' )
 AND...


Backtesting model results, but backtesting output sampled at different frequency than model output

Question: So, I'm trying to backtest a model that computes P&L. This model pulls sensitivities on a weekly basis and applies market shocks to these sensitivities to project quarterly P&L. I want to compare this to clean (backtesting) P&L. The issue is that the backtesting P&L is daily. One could aggregate the daily P&L over a given quarter to compare against the model... but since the model only pulls sensitivities weekly, if the portfolio were to change materially intra-weekly (e.g., pull the sensitivities on Monday of Week 1, but on that Wednesday the portfolio changes, and then the portfolio composition pulled on Monday of Week 2 is similar to that of Monday Week 1) it would not be captured. Is there any way to compare the two results?
Answer: It's not clear what you're asking or even trying to do.
Based on my read, you have a trading model you're using that takes inputs weekly to produce some kind of PnL.  It's not clear what you mean by 'clean (backtesting) P&L' for the comparison.
As a general matter though, comparing one set (for simplicity's sake) of returns to another set aggregated over a different interval can be dealt with by bring return interval of each in line (eg, average daily return by some annualization figure (250/252) to compare to annual returns elsewhere).
As to your model potentially missing something by only taking inputs weekly...well, yeah, that's a limitation of updating only weekly.  That doesn't mean a comparison is any less valid...just that your model only incorporates updates weekly, part of the framework you've chosen.


jQuery Dashboard plugin - how to save a state change

Question: I've started using the dashboard plugin which is demoed here - http://www.gxdeveloperweb.com/dashboardplugin/demo/dashboard.html
I'm struggling with the documentation. Primarily on how to save dashboard configurations altered by the enduser.
In the documentation, it tells you how to do a "dashboardStateChange":
dashboard.element.trigger("dashboardStateChange",{"stateChange":"widgetAdded","widget":widget});

But I don't really understand where this is to go within the dashboard setup, and how you use this to save the changes. I thought I could could access dashboardStateChange from within the DOM when something happens, but even failing to understand how this is done.
Has anyone got any tips on saving the dashboard whenever its state has changed? I would like it to talk to a php script which saves the dashboard setup.
Unfortunately there aren't any great tutorials on this sort of functionality.
Thanks!
Comment: did you make ay progress with this?
Answer: I don't know if this question is still of interest but I've been using this plugin for quite a while and it's actually quite easy to use.
Pretty much all of the answer can be found in the example that comes with the plugin and to your problem you might want to have a look at the following example code that I use to make the current layout of the dashboard persistent on the server.
Please note that "saveID" is the ID of a Save button and "saveConfiguration" is the URL that save the layout on the server.
// binding for saving the current configuration
$("#saveID").bind("click", function () {
    var conf = $.parseJSON(dashboard.serialize()),
        // get the serialized configuration
        len = conf.data.length,
        // generate the new parameter to submit
        para = "lay=" + conf.layout + "&len=" + len,
        i = 0;
    for (i = 0; i < len; i += 1) {
        para = para + "&pid" + i + "=" + conf.data[i].id + "&col" + i + "=" + conf.data[i].column;
    }

    // Invoke the "saveConfiguration" on the server via AJAX
    $.ajax({
        url: "saveConfiguration",
        data: para,
        dataType: "json",
        success: function (jsonResponse) {
            if (jsonResponse.valid === true) {
                alert("Configuration has been saved");
            } else {
                alert("Error when trying to save the configuration\n" + jsonResponse.error);
            }
        },
        error: function (jqXHR, textStatus, errorThrown) {
            alert(textStatus + " - " + errorThrown);
        }
    });
    return false;
});

Answer: You can use the built in dashboard function to save quick & easy. On the page where you init the dashboard, put this after the initDashboard() function, but before the dashboard.init():
$("#savebutton_id").bind("click", function () {
    dashboard.element.trigger("dashboardStateChange",{"stateChange":"widgetMoved","widget":"w"});
    alert("Saved");
});

Then you put a Button or Link with the id savebutton_id somewhere in your HTML-Code. When you click it, the dashboard will send the serialized configuration to your predefined stateChangeUrl.


How much time should a Project Manager spend on a typical IT based project

Question: We've had a number of projects where the costs have been scrutinised recently and one thing that has come out is that people believe there is too much time allocated to the project managers' role.
For example, we have a development project which will take 10 days of development time, 5 days for testing, 3 days for technical documentation, 1 day for functional spec and 7 days for PM.
Generally (for IT projects) what are peoples thought on percentage of time for each role? Development, Testing, BA, PM etc.??
Update: Assuming the BA has done a good job and the requirements are sufficient for minimal rework
Comment: In my last project, I never even met the PM. I didn't even know we 'had' one till 6 months in. He never did do any work for us...
Answer: we have %20 ratio which means that if PM is also developer(in my case it's me) if I spent 180hrs for all the implementation in a project I can use 36hrs for PM stuff.
But it is mostly dependent on your organization type.
Answer: This is a biiiiiiig question with no specific answers, only opinions and suggestions.
How good are your developers at estimation? 10 perfect days for development actually means 15 real days because nobody can code at 100% speed (velocity) - there are invariably interruptions during the day which suck up time (and your concentration).
You cannot put a figure on how much time the BA or PM should spend on a project, there are too many variables. Everyone has to work harder if the BA hasn't done a good job. The testers and the PM have to work harder if the developer doesn't do a good job. Everyone has to work harder if the requirements are changing due to too much client input. You see what i mean.
Answer: I guess it depends on how responsive your customers are when working with the PM. If those seven days the PM spends means that the developers know all they need to know before they start coding, it is probably just fine.
If the developers are constantly blocked because the PM didn't do a good enough job collecting the requirements and goals from your customers, then the PM is taking a long time to not do the job well enough.
If the PM is spending all his or her time perfecting diagrams or making pretty powerpoints, maybe it isn't time well spent.
It's really tough to say, but based on the fact that there is grumbling, I wonder if that is a polite way of criticizing the quality of the PM's work.


Windows 10 BootCamp Drivers

Question: Would it be harmful to my rMBP if I installed Windows 10 when it is released?
I was talking to someone about it, and because Apple uses non-standard hardware voltages could cause damage using the drivers for Windows 8.1
Comment: It is a problem to wait for the official driver support?
Comment: Recently I'd upgrated my win 8. Everything is nice except hot keys... they do not work! P.S I installed windows on macbook pro 2013
Answer: I am currently using Windows 10 TP (Technical Preview Build: 10240) on my MacBook Pro Late 2011. I am using Boot Camp with the drivers made for previous Windows versions. I haven't had any issues with using it but after upgrading to an newer build I was needing to reinstall the driver package again to get it to work properly.
Also, as Steve Chambers said in his answer, it won't physically break or damage your Mac. Only remember that if you are upgrading from a previous Windows version, make a backup in case you need to go back or do a clean install. In addition, it could be a good idea to have the Windows drivers ready on a USB flash drive just in case.
This is tested with the latest TP (Technical Preview) build of Windows 10 but could change in the final version (unlikely but could). If you are not in a hurry, wait a week and then do a Google search and see if anyone had any issues with using the released Windows 10 version on Boot Camp.
Answer: Rob has the gist of this because Apple has not released official Windows 10 drivers and installing Windows 10 on your Mac may or may not work.
That said often times you can use previous Windows version drivers on the next version. That often worked when Windows 7 came out, you could use Vista drivers and they usually worked.
So it is possible that installing Windows 10 by upgrading a working copy of Windows 8.1 would work. In fact we would all like to know if it did, or not. And what, if anything, did not work (EG sound, trackpad, video, etc.).
So you should be safe installing Windows 10 over top of 8.1. And it is unlikely that doing so will physically damage your Mac (YMMV) but you could very well make your current Windows installation unusable and have to reinstall.
Answer: I upgraded to Windows 10 on a Macbook Pro 2013 model. Everything work fine except hotkeys.
I reinstalled the apple keyboard driver and now those work!
Note: drivers can be found at https://support.apple.com/downloads/DL1720/en_US/BootCamp5.1.5621.zip
Comment: same here. Thanks for pointing me to re install the keyboard driver
Answer: Upgraded to Windows 10 without any issues, ATI drivers will be replaced by standard Windows drivers and will limit you in extra options available for ATI Radeon R9, Sleep mode won't be available, also touch pad won't work properly as well.
Answer: Apple just released the Bootcamp 6 for Windows 10.

You can use Boot Camp to install Windows 10 on supported Mac models
  that have OS X Yosemite installed.  System Requirements
You need support software (drivers) installed with Boot Camp to use
  Windows 10. This software is automatically downloaded when you use
  Boot Camp Assistant. Boot Camp supports 64-bit versions of Windows 10
  when used with a supported Mac.
Windows 10 is available from Microsoft as an ISO file, an installation
  DVD, and a USB flash drive. You need an ISO file of the 64-bit version
  of the Windows 10 installer to install Windows on your Mac. If you
  don't have an ISO file, you can use Disk Utility to make one from your
  Windows installation DVD or USB flash drive. If you're installing
  Windows for the first time, make sure the Windows installer you're
  using is for a full installation (not an upgrade installer).

Windows 10 BootCamp Drivers


web based chat application

Question: hii.. i am designing a chat application. i have tried using php + MySQL + JavaScript and developed the web based chat app. But the application is quite slow. What all i do is, just store the messages from the clients in a table, and each client retrieves the table at a lag of 2 seconds.... I manage this by ajax.
But the app response becomes very bad when many user joins.
Is their any other technique to build the chat app ??? or what else i can do to make my app better.
help plzz ..
thanks in advance :)
Answer: Don't know if you've touched upon it, but I'd recomend using an IRC server as backend.
Answer: If you have the ability to install nodejs(basicly server side javascript) on your server you should take a look at socket.io which is a plugin for nodejs. This gives you almost an instant response time, even for quite large masses of users.
There are almost no libraries/projects for real-time web applications in PHP. But if you really want to use it you can take a look at a technique called long-polling. This can still be quite heavy on your server though.
Answer: Maybe it is slow because each client retrieves full table of chat contents - try appending only the new messages.
Answer: I've done the same thing last year.
I suggest retrieving only so many chats when the user first logs in, e.g. the last 30, and displaying them. Then on each subsequent AJAX call only retrieve any new chat messages, rather than everything else again. You can do this by storing the latest chat id (a unique id) when you first retrieve all the chat msgs and then only retrieve anything with a chat id greater than that.
How often do you check for new msgs? You could also increase that time.

web based chat application


how to assign different templates to different page or article?

Question: In joomla 3, i need to know how to assign different templates to different pages or articles?
Answer: For Pages:

Inside each menu item you can see an option called Template Style, assign here the template for each menu item, see the screenshot:

Also you can do this if you go to:
Extensions > Templates > Your Template > Tab Menu Assignment
For Articles:

You can use an Alternative Layout for each Article, find this option in the tab called Options at the bottom of the page, see the screenshot:

Here you can find more information:
https://docs.joomla.org/Layout_Overrides_in_Joomla
Answer: From admin panel you can only assign template to menu item (Itemid) so you can link articles to menu items and you're good to go.
In php you can assign it via setting templateStyle variable.
If you want to do this without coding, to do it all through admin panel you'll need custom plugin.


Could a certificate authority and a ISP preform a MITM attack on HTTPS traffic?

Question: I'm just wondering if it is technically possible for your ISP to work with a certificate authority (either compelled by a government agency or otherwise) to create a MITM attack to see into your https traffic.  I've used a few MITM servers from time to time to look at network traffic. When it's encrypted, I'll install the locally generated certificate from the MITM software on my OS and just like that I'm seeing the green locked icon and able to see into HTTPs connections.  So I'm wondering is it possible for an ISP to get a CA to mint certificates on the fly for whatever website a user is accessing and give the user of the ISP an https page with no warnings or errors while still being able to see the traffic.  I'm going to of course exclude Certificate pinning.
Comment: Does this answer your question? [Can ISP use MITM attack to "break" encrypted traffic?](https://security.stackexchange.com/questions/64352/can-isp-use-mitm-attack-to-break-encrypted-traffic)
Comment: This scenario is not much different than the incident that took place in Iran in 2011, involving the CA Diginotar.  See https://security.stackexchange.com/questions/230689/if-an-adversary-took-over-a-major-certificate-authority-what-bad-things-could-t.  The only difference is that in that case, the CA did not cooperate with the ISP willingly - instead, the CA was breached.
Comment: @mallocation I'm don't think that question really answers the question with the specifics for using a CA so that the client doesn't see a self signed cert error.
Answer:
So I'm wondering is it possible for an ISP to get a CA to mint certificates on the fly for whatever website a user is accessing and give the user of the ISP an https page with no warnings or errors while still being able to see the traffic.

While it would technically be possible to do so it would be overly complex. It is much easier that a CA creates a new intermediate CA certificate which the ISP then can use to issue new certificates on the fly itself. This will work as long as the domain is not explicitly pinned to a specific certificate or CA in the client (like done with google, facebook etc in modern browsers) since the browser will trust any locally trusted CA for any domain.
Publicly trusted CA actually sell intermediate CA in some cases but usually explicitly forbid misuse for MITM. Such "accidents" still happened in the past, see here or here. See also Can a nation-state adversary perform a MITM attack by compelling a CA to issue them with fake certs? for a related question.
Note that a CA which either deliberately issues false certificates, was compromised or shows otherwise bad behavior will usually be revoked as trusted from the browsers, no matter how big the CA is. This happened in the past with DigiNotar, Startcom/WoSign and Symantec.
Comment: Star>t<com/WoSign (aka StartSSL). And Symantec was _threatened_ with distrust, but sold to Digicert before the deadline.
Comment: @dave_thompson_085: thanks for the correction. I've included it.
Comment: @SteffenUllrich Does Google use pinned CA or any measure against MITM?
Comment: @user215422: *"Does Google use pinned CA or any measure against MITM?"* - I'm not sure what you mean with this. Certificate pinning is a client side method (i.e. not a "Google" thing, unless you mean the Chrome browser) and as I wrote in my answers modern browsers use this to protect access to Google, Facebook etc.


Mathematics for genetics

Question: What types of mathematics are useful for studying genetics? Of course, statistics is, and I'm guessing set theory and group theory, but anything else? What about ordinary and partial differential equations?
Comment: Calculus is used pretty extensively in population biology. This can often overlap with genetics (modelling change in allele frequency over time for instance).
Answer: Genetics is a very wide field of knowledge and many different areas of mathematics are being applied to genetics. Here is a probably not exhaustive list of the fields of mathematics that I have encountered in genetics (you will note that the elements of the list are not mutually exclusive)

diffusion equations
differential equations
markov processes
birth-death process
probability theory (a lot of it)
Bayesian probabilities
statistics
Math related to MCMC processes as well as HMC processes
Many fields of theoretical computer science are being applied and I guess theoretical computer science is a field of mathematics.
Graph theory
numerical integration
Analysis of dynamic systems

You say

set theory

Yes of course

group theory

Probably not so much or maybe I jsut don't really know what it is

ordinary and partial differential equations

I think pretty much any field of science applying mathematics will use differential equations.

But of course, not all geneticists are good mathematicians. Each geneticist specialize in a particular subfield. Some of them do a lot of mathematical modelling, others don't do any. Statistics and everything related to data science will always be useful though.
Comment: Your answer is very intersting, however I'd find it even greater with a short explanation of how each  area is used for genetics. For example, it is not obvious to me how diffusion equations are applied to genetics.
Answer: From my understanding, it depends a lot on the sub-field you're in.
Data science, statistics and machine learning follow a different paradigm than calculus. Whereas data driven approaches to problem solving are generally concerned with developing predictive models of the underlying system, differential equation based approaches describe a mechanistic model.
These 'top down' and 'bottom up' approaches both have their benefits and drawbacks. On the data science side, it is very difficult to get a low-level understanding of the system. An oversimplification would be:
"The cell is a black box, so let's figure out the output for a given input to get a better understanding of what's going on inside."
On the calculus side, although mechanistic descriptions are a mathematical formalism of what's going on inside the system (and thus imply a complete understanding of the system - in theory), there is still so much that is unknown about most biological systems you'd care to model. This kind of modelling (from the discussions I've had) will be important in the future, when more is known about these biological systems, but for now it is constrained to small sub-systems. A good analogy might be:
"It's hard to figure out how an engine works when we don't know what half of the parts do."
Of course, there are many projects that bridge the gap between the above two methodologies.
So, to answer your question, statistics, computer science, machine learning, linear algebra, calculus, graph theory, set theory, optimization and combinatorics are all useful.

Mathematics for genetics


what's a long-shot job?

Question: I know that "long-shot" roughly means "improbable", but I am not sure what a long-shot job is, at least in the context of searching for such a job. Is it a really odd job, a job where the appliant has very few possibilities of being hired, or something else?
Comment: by the way, I found the expression in the following passage of *Surfaces and Essences* by Douglas Hofstadter and Emmanuel Sander: «Advising a friend who's applied for several long-shot jobs of which one has suddenly come through and needs an instant reply or it will be lost forever [...]»
Answer: A "long-shot" in terms of a job search is similar to any other "long-shot" attempt at something. It is a job that the speaker could apply to, but has little chance or expectation of getting. As an example, consider a generally unremarkable fresh graduate from college saying the following:

[Major multinational company] just fired their CEO and is looking for a new one. It's a long shot but I think I'll apply!

In this case the speaker is probably being humorous, but you could use this term to describe applying for a position for which you are somewhat, but not completely qualified, in the hopes of impressing the hiring manager and/or recruiter enough to get the job anyway.
Point of clarification: as @Chokkeliet mentioned, "long-shot job" sounds odd and is not necessarily a phrase that is often used, however you can describe a job as being a "long-shot"
Another expression you may sometimes hear in place of "long-shot" is "Hail Mary" which I believe is a reference to a Hail Mary pass as explained in this section.
 Hope that helps
Comment: I got a long-shot job once. I really didn't have the proper credentials, but they were desperate for a quick hire, and no one else had applied, so they hired me. I think you've described it well.
Answer: From wikitionary:

long shot (plural: long shots)
(idiomatic, nautical) Something unlikely; something that has little chance of happening or working. The term arose from the accuracy of early ship guns, which were effective only at close range and unlikely to hit the mark at any great distance.
We can try your plan, but it's a long shot and it probably won't work.

Though, in general, I'd consider "long-shot job" to have at least two clearly different meanings (as opposed to a job that is a long shot). The first is it means that it's a job (read: occupation) that's really hard or difficult to get. The second is it means that it's a job concerned with working on things that are hard or difficult to complete or finish.
Unless, however, a "long-shot job" is some kind of slang that I've never heard before...
Comment: You're right, broken is a little too brash I'll edit my answer.
Comment: Thanks for the edit!  I'll just re-write part of my old comment here: This reminds me of Jim Butcher, who uses *longshotauthor* as his Twitter profile name.
Answer: A "long shot" is a gambling term, typically used in referring to horse races.
In the U.S., wagering on horse races uses a "parimutuel" system for determining the value of a winning bet. Increased wagerng on a particular horse will cause the amounts paid to winning bettors to decrease; diminished wagering on a particular horse will cause the amounts paid to winning bettors to increase. The more a horse becomes unpopular among bettors, it becomes more of a long shot, and the odds paid on a winning ticket might increase to 20-1, or 30-1, in other words winning ticket holders might be paid $42 or $62 on a $2 wager.
Usually (but not always) the actual probability that a horse will win the race correlates with the wagering odds, due to the "wisdom of crowds." So the term "long shot" refers to an improbable event; and also to the fact that, if wagering is permitted on the outcome of the event, an increased payment is had if one bets on the improbable event and it occurs.

what's a long-shot job?


Does the MicroKORG XL+ have internal speakers?

Question: I just bought a MicroKORG XL+ and have plugged in the power adapter and turned this on. The volume is up but it makes no sounds. Does it have its own speaker? Or do I need to have this connected to an external speaker/amp/headphones?
Comment: From the manual: "1. [VOLUME] knob
This adjusts the volume of the OUTPUT jacks (L/MONO, R) and head-phone jack.". This is their way of saying that it does not have speakers, for future situations like these.
Comment: A google for "MicroKORG XL+ manual" would likely have given you the answer.
Comment: I couldn't find it in the manual, which is why I was asking in this forum.
Comment: I see. That is good information to put in the post, since we get a lot of these type of questions. Then you'll avoid cranky type comments like these. Fortunately one of our less cranky users gave you an answer :)
Answer: It doesn't have its own speaker, you'll need one.
In the back it has an output section with 3 outputs labeled as: R, L, and headphones. You can use those to connect the microKORG to amps, speakers, or headphones.


How can I avoid re-computation of Dijkstra algorithm if I add or remove one edge from a graph?

Question: I have a nested graph filtration and each step I have to find the shortest path between two nodes. At each step I just add one edge to the graph so the re-computation of the Dijkstra algorithm is extremely redundant. Is there any algorithm to circumvent this?
Comment: Please look for "Dynamic Shortest Path" - you'll find a plenty of algorithms
Answer: Pathfinding algorithms that are able to recompute the best path when the graph changes without doing a full recomputation are called "Incremental".
The incremental version of Dijkstra's algorithm has the horrible name DynamicSWSF-FP.
The much more common algorithm which combines this with A* is called LPA*
Answer: You could compute a full Single Source Shortest Paths (SSSP) at the beginning for both of your vertices (s and t).
Then, whenever you add an edge, you update only the shortest paths affected, i. e. you check whether the edge uv provides an improvent for sv, su, tv or tu. If not, your SSSP is still correct. If it gives an improvement, you then also have to check the neighbors for updates. This cascades similarly as the Dijkstra algorithm.
I can't come up with an asymptotic bound right now, but unless the graph and insertion order are chosen adversially, a single edge really shouldnt often invoke a change in large parts of the graph (and when it happens, you have to recompute anyway).


Can we allow unsigned Certificate during Installation and still run the Marketing automation service

Question: I am trying to install Sitecore 9.3 using the PowerShell scripts "XP0-SingleDeveloper.ps1".
The script stops the installation and throws error on starting the Marketing Automation service.

Waiting for service 'Sitecore Marketing Automation Engine - OnePOC.xconnect-MarketingAutomationService
(OnePOC.xconnect-MarketingAutomationService)' to start...
Install-SitecoreConfiguration : Failed to start service 'Sitecore Marketing Automation Engine -
OnePOC.xconnect-MarketingAutomationService (OnePOC.xconnect-MarketingAutomationService)'.

I am aware about this issue and one solution. This occurs when there is an un-signed certificate in root of cert store. I know about the PowerShell script that will move the certificate in a different location and the installation will work. I fixed this issue multiple times in previous project and wrote a blog as well https://darjimaulik.wordpress.com/2020/07/20/sitecore-xconnect-certificate-error-http-response-was-not-successful-forbidden/
But this time, I want to install Sitecore 9.3 without moving the certificate and XConnect must work.
I am looking for some option to Allow Invalid certificate during the installation.
I have 2 more installation earlier on the same machine and when I ran the script earlier, It found a Certificate and moved it. This certificate is for our VPN connection. Moving that created some major issues in security. I want to avoid the same issue again.
The Answer mentioned at Sitecore 9.3 Installation failing - 'Failed to start the Marketing Automation Engine service Does not help in my case.
Answer: You can remove the marketing automation startservice in xconnect-xp0.json and continue with your installation. once installation is completed, you can start the service manually.


how many years is patent good for 6092612

Question: how long is this patent protection 6092612
Comment: Patent expiration can be estimated using the patent term calculator http://www.uspto.gov/patents/law/patent_term_calculator.jsp
Answer: Actually, the priority date for this patent is Jun 7, 1995, which predates the switch from 17-years from issue to 20-years from filing.

For applications filed before June 8, 1995 and for patents that were
  still in force on June 8, 1995, the patent term is either 17 years
  from the issue date or 20 years from the filing date of the earliest
  U.S. or international (PCT) application to which priority is claimed
  (excluding provisional applications), the longer term applying.

So the term would either be 2017, since it was issued in 2000, or 2015, because its priority date is 1995, the choice would be the Patent Owner's.
There is one additional factor you need to be aware of, which is patent term extensions.  Sometimes, if the Patent Office moves too slowly, they give extra time to the patent.  You can look this up at the USPTO on PAIR: http://portal.uspto.gov/external/portal/pair.  (I'd look it up but it's down for maintenance).
Answer: Patents have a term of 20 years from the earliest filing date.
It was filed in 1998, 20 years from that makes 2018.
`
Note: terms for design patents is different and is 14 years from date of grant. (15 years if filed after 2013)


Books for learning applied seismic geophysics

Question: I am a software developer trying to learn applied geophysics. Specifically I am interested in seismic attributes. I have a strong background in mathematics and signal processing and therefore grasp the theory quite easily. However the geology and the applied part is a problem for me. What i would like is a book/tutorial that takes the reader trough very detailed concrete examples with no theory whatsoever. Any suggestions?
Comment: Can you clarify what you mean by 'examples' and 'with no theory whatsoever'? Do you mean geological examples, with no geological theory, or attribute analysis examples, with no seismic theory? Most (useful) case studies have a bit of both...
Comment: Many books use a lot of pages describing the theory. This information is easy to get hold off. What is difficult is to learn a bit of the practical knowledge a seismic interpreter holds without working as a junior geophysicist. As an example say that the tutorial extracts several seismic attributes with different settings (timegates)on an interpreted horizon and displays the images: Next the tutorial goes on to pinpoint say a channel on the images and explain why it appears clearer on one of the images. Also the tutorial should explain briefly about the geology and ideally distribute the data.
Answer: Here's a list of resources I've compiled before. Between them, maybe you'll find what you're after:

Some important geophysics papers and books: Must-read geophysics.
Six books about seismic interpretation — most of these include something about seismic attributes.
Six books about seismic analysis — more quantitative, and usually with lots of theory. I especially recommend Simm & Bacon.

I recommend learning what you can about rocks — their genesis, their properties, and especially their acoustic and elastic behaviour. If possible, go and see outcrops or at least cores. If possible, take classes in sedimentology, petrology, or even reservoir engineering.
You need to read about integrated interpretation; here are some other phrases to look for: well ties, phase estimation, spectral decomposition, seismic inversion, pre-stack seismic analysis, AVO. I recommend subscribing to CSEG Recorder, EAGE First Break and SEG Leading Edge.
Good luck in your quest!
Comment: Thank you very much kwinkunks! BTW I enjoy reading the agilegeoscience blog.


Is there a quick proof as to why the vector space of $\mathbb{R}$ over $\mathbb{Q}$ is infinite-dimensional?

Question: It would seem that one way of proving this would be to show the existence of non-algebraic numbers. Is there a simpler way to show this?
Comment: A finite dimensional vector space over $\mathbb{Q}$ is countable.
Comment: @Isaac: how is the fact that $\mathbb{R}$ is finite dimensional over itself relevant?
Comment: @Steve: Please add that as an answer so people can upvote.
Comment: Does that mean that a vector space over $\mathbb{Q}$ is finite-dimensional iff the set of the vector space is countable? If so, please prove it.
Comment: @Isaac Your question doesn't require the 'only if' anyway. Steve's observation answers your original question.
Comment: @yasmar $\mathbb{R}$ is finite-dimensional over itself. How does Steve's proof follow?
Comment: @Arturo: I thought he was referring to $\mathbb{R}$ when he said "a finite-dimensional vector space." I now realize he was demonstrating the impossibility of the alternative. Thanks for your proof below.
Answer: The cardinality argument mentioned by Arturo is probably the simplest. Here is an alternative: an explicit example of an infinite $\, \mathbb Q$-independent set of reals. Consider the set consisting of the logs of all primes $\, p_i.\,$ If $ \, c_1 \log p_1 +\,\cdots\, + c_n\log p_n =\, 0,\  c_i\in\mathbb Q,\,$ multiplying by a common denominator we can assume that all $\ c_i \in \mathbb Z\,$ so, exponentiating, we obtain $\, p_1^{\large c_1}\cdots p_n^{\large c_n}\! = 1\,\Rightarrow\ c_i = 0\,$ for all $\,i,\,$ by the uniqueness of prime factorizations.
Comment: @Bill +1 What a nice example.
Comment: Can you extend the idea of this proof to get the right dimension? Currently, you only have a countably infinite independent set, but the dimension is size continuum.
Comment: @Bill. Wow!  :-)
Comment: @student this can not happen: the primes are distinct. Put the primes with negative exponent on the other side (exponents become positive). You would find two distinct prime factorizations of the same number.
Comment: A lovely idea, but what if the coefficients are negative integers? Here is a possibly more modest alternative. We observe to begin with that transcendental numbers exist (purely using cardinality considerations : the reals are uncountable while the algebraic numbers are only countably infinite.) Now let $x$ be any transcendental number. Then by the definition of transcendence the set $\{1,x,{x^2},\cdots\}$ must be linearly independent over the rationals.
Comment: Is this proof unique to Q or does it generalize to provide explicit examples of reals linearly independent over, e.g., Q(sqrt(2))?  Above, Q appears to be "hard-wired" into the proof, as the group of exponents in the prime factorization.
Comment: @T..: The proof might carry over to fields with class number $1$, via Baker's theorem. Then, any number field field has a finite extension whose class number is $1$. But Baker's theorem is more complicated than what Bill D. does.
Comment: @George S. "Then, any number field has a finite extension whose class number is 1."  This would imply in particular that there are infinitely many number fields of class number one, which I am pretty sure is an open problem.  I wonder what you are thinking here?
Comment: I meant to ask what if SOME coefficients are negative integers?
Comment: $(\mathbb{Q}^{+})_{\mathbb{Z}}$ can be made into a module, vector addition takes as usual number product $q_1/p_1+q_2/p_2=q_1q_2/p_1p_2$ , scaler product takes as the exponential product $c\cdot p/q=(p/q)^c$. Then the prime integers in $\mathbb{Z}$ become a basis.
Answer: As Steve D. noted, a finite dimensional vector space over a countable field is necessarily countable: if $v_1,\ldots,v_n$ is a basis, then every vector in $V$ can be written uniquely as $\alpha_1 v_1+\cdots+\alpha_n v_n$ for some scalars $\alpha_1,\ldots,\alpha_n\in F$, so the cardinality of the set of all vectors is exactly $|F|^n$. If $F$ is countable, then this is countable. Since $\mathbb{R}$ is uncountable and $\mathbb{Q}$ is countable, $\mathbb{R}$ cannot be finite dimensional over $\mathbb{Q}$. (Whether it has a basis or not depends on your set theory).
Your further question in the comments, whether a vector space over $\mathbb{Q}$ is finite dimensional if and only if the set of vectors is countable, has a negative answer. If the vector space is finite dimensional, then it is a countable set; but there are infinite-dimensional vector spaces over $\mathbb{Q}$ that are countable as sets. The simplest example is $\mathbb{Q}[x]$, the vector space of all polynomials with coefficients in $\mathbb{Q}$, which is a countable set, and has dimension $\aleph_0$, with basis $\{1,x,x^2,\ldots,x^n,\ldots\}$.
Added: Of course, if $V$ is a vector space over $\mathbb{Q}$, then it has countable dimension (finite or denumerable infinite) if and only if $V$ is countable as a set. So the counting argument in fact shows that not only is $\mathbb{R}$ infinite dimensional over $\mathbb{Q}$, but that (if you are working in an appropriate set theory) it is uncountably-dimensional over $\mathbb{Q}$.
Comment: Related to the note about uncountable dimension, there are explicit examples of continuum-sized linearly independent sets, as seen in this MathOverflow answer by François G. Dorais: http://mathoverflow.net/questions/23202/explicit-big-linearly-independent-sets/23206#23206
Comment: Yes: but can one show that there is a *basis* for $\mathbb{R}$ over $\mathbb{Q}$ without some form of the Axiom of Choice? (There is a difference between exhibiting a large linearly independent subset and exhibiting a basis).
Comment: No, one cannot, but without the Axiom of Choice the notion of dimension breaks down (except for finite vs. infinite). Assuming AC (as I virtually always do), the size of a linearly independent set gives a lower bound on the dimension of the vector space, and I think it is wonderful that in this case such "explicit" proof exists that the real numbers have continuum dimension, as opposed to the nice qualitative proof one could give by extending your argument to larger cardinals.
Comment: @Jonas: No argument there (with any of your points).
Comment: good link @Jonas, thanks
Answer: For the sake of completeness, I'm adding a worked-out solution due to F.G. Dorais from his post.
We'll need two propositions from Grillet's Abstract Algebra, page 335 and 640:

Proposition: $[\mathbb{R}:\mathbb{Q}]=\mathrm{dim}_\mathbb{Q}{}\mathbb{R}=|\mathbb{R}|$
Proof: Let $(q_n)_{n\in\mathbb{N_0}}$ be an enumeration of $\mathbb{Q}$. For $r\in\mathbb{R}$, take
$$A_r:=\sum_{q_n<r}\frac{1}{n!}\;\;\;\;\text{ and }\;\;\;\;A:=\{A_r;\,r\in\mathbb{R}\};$$ the series is convergent because $\sum_{q_n<r}\frac{1}{n!}\leq\sum_{n=0}^\infty\frac{1}{n!}=\exp(1)<\infty$ (recall that $\exp(x)=\sum_{n=0}^\infty\frac{x^n}{n!}$ for any $x\in\mathbb{R}$).
To prove $|A|=|\mathbb{R}|$, assume $A_r=A_{s}$ and $r\neq s$. Without loss of generality $r<s$, hence $A_s=\sum_{q_n<s}\frac{1}{n!}=\sum_{q_n<r}\frac{1}{n!}+\sum_{r\leq q_n<s}\frac{1}{n!}=A_r+\sum_{r\leq q_n<s}\frac{1}{n!}$, so $\sum_{r\leq q_n<s}\frac{1}{n!}=0$, which is a contradiction, because each interval $(r,s)$ contains a rational number.
To prove $A$ is $\mathbb{Q}$-independent, assume $\alpha_1A_{r_1}+\cdots+\alpha_kA_{r_k}=0\;(1)$ with $\alpha_i\in\mathbb{Q}$. We can assume $r_1>\cdots>r_k$ (otherwise rearrange the summands) and $\alpha_i\in\mathbb{Z}$ (otherwise multiply by the common denominator). Choose $n$ large enough that $r_1>q_n>r_2\;(2)$; we'll increase $n$ two more times. The equality $n!\cdot(1)$ reads $n!(\alpha_1\sum_{q_m<r_1}\frac{1}{m!}+\cdots+\alpha_k\sum_{q_m<r_k}\frac{1}{m!})=0$. Rearranged (via $(2)$ when $m=n$), it reads
$$-\alpha_1\sum_{\substack{m<n\\q_m<r_1}}\frac{n!}{m!}-\cdots-\alpha_k\sum_{\substack{m<n\\q_m<r_k}}\frac{n!}{m!}-\alpha_1 =\alpha_1\sum_{\substack{m>n\\q_m<r_1}}\frac{n!}{m!}+\cdots+\alpha_k\sum_{\substack{m>n\\q_m<r_k}}\frac{n!}{m!}.
\tag*{(3)}$$
The left hand side (LHS) of $(3)$ is an integer for any $n$. If $n$ is large enough that $(|\alpha_1|+\cdots+|\alpha_k|)\sum_{m=n+1}^\infty\frac{n!}{m!}<1$ holds (such $n$ can be found since $\sum_{m=n+1}^\infty\frac{n!}{m!}=\frac{1}{n+1}\sum_{m=n+1}^\infty\frac{1}{(n+2)\cdot\ldots\cdot m}\leq\frac{1}{n+1}\sum_{m=n+1}^\infty\frac{1}{(m-n-1)!}\leq\frac{1}{n+1}\exp(1)\rightarrow 0$ when $n\rightarrow\infty$), then the absolute value of RHS of $(3)$ is $<1$, and yet an integer, hence $\text{RHS}(3)=0$. Thus $(3)$ reads $\alpha_1=-\sum_{i=1}^{k}\sum_{m<n,q_m<r_i}\alpha_i\frac{n!}{m!}=0\;(\mathrm{mod}\,n)$. If moreover $n>|\alpha_1|$, this means that $\alpha_1=0$. Repeat this argument to conclude that also $\alpha_2=\cdots=\alpha_k=0$.
Since $A$ is a $\mathbb{Q}$-independent subset, by proposition 5.3 there exists a basis $B$ of $\mathbb{R}$ that contains $A$. Then $A\subseteq B\subseteq\mathbb{R}$ and $|A|=|\mathbb{R}|$ and Cantor-Bernstein theorem imply $|B|=|\mathbb{R}|$, therefore $[\mathbb{R}:\mathbb{Q}]=\mathrm{dim}_\mathbb{Q}{}\mathbb{R}=|\mathbb{R}|$. $\quad\blacksquare$
Comment: The only proper answer to the question. Such a shame that it is not the most voted answer.
Comment: Way to nail it down, nice work.
Comment: @user195218 It's not a basis, as it doesn't span the reals, but it is uncountable and linearly independent.
Comment: Is this uncountable  linearly  independent  set basis ?
Answer: No transcendental numbers are needed for this question. Any set of algebraic numbers of unbounded degree spans a vector space of infinite dimension.  Explicit examples of linearly independent sets of algebraic numbers are also relatively easy to write down.
The set $\sqrt{2}, \sqrt{\sqrt{2}}, \dots, = \bigcup_{n>0} 2^{2^{-n}} $ is linearly independent over $\mathbb Q$. (Proof: Any expression of the $n$th iterated square root $a_n$ as a linear combination of earlier terms $a_i, i < n$ of the sequence could also be read as a rational polynomial of degree dividing $2^{n-1}$ with $a_n$ as a root and this contradicts the irreducibility of $X^m - 2$, here with $m=2^n$).
The square roots of the prime numbers are linearly independent over $\mathbb Q$.  (Proof: this is immediate given the ability to extend the function "number of powers of $p$ dividing $x$" from the rational numbers to algebraic numbers. $\sqrt{p}$ is "divisible by $p^{1/2}$" while any finite linear combination of square roots of other primes is divisible by an integer power of $p$, i.e., is contained in an extension of $\mathbb Q$ unramified at $p$).
Generally any infinite set of algebraic numbers that you can easily write down and is not dependent for trivial reasons usually is independent. This because the only algebraic numbers for which we have a simple notation are fractional powers, and valuation (order of divisibility) arguments work well in this case.  Any set of algebraic numbers where, of the ones ramified at any prime $p$, the amount of ramification is different for different elements of the set, will be linearly independent. (Proof: take the most ramified element in a given linear combination, express it in terms of the others, and compare valuations.)
Comment: @ALannister I realize you questioned quite a long time ago, but s/he is assuming that there is such $n$ and showing that such assumption leads to contradiction. So in fact, s/he is proving exactly that $n$-th root of $2$ cannot be expressed by a linear combination of previous roots
Comment: I realize you answered this question a loooong time ago, but if you're still around, how do you know that you can write the $n-$th root of $2$ as a linear combination of the $1st$ through $n-1$st roots of $2$?
Answer: As $\pi$ is trascendent over $\mathbb{Q}$. Then the set $\{1, \pi, \pi^{2},\cdots\}$ is linearly independent.
Comment: I'm like 2 years late but 1) How does this imply that $\{ 1,\pi, \pi^2, \dots \}$ is linearly independent? 2) How does the set being linearly independent show that the vector field is infinitely-dimensional?
Answer: Another simple proof:
Take $P=X^n-p$ for a prime $p$.
By Eisenstein's criterion, it is $\mathbb Q[X]$-irreductible. Therefore, the set of algebraic numbers is of infinite dimension over $\mathbb Q$.
Since $\mathbb R$ is bigger, it works for $\mathbb R$ too.
Answer: Let $n$ be a positive integer.
Let $(\alpha_i)_{1 \le i \le n}$ be a family of $n$ nonzero real numbers.
Proposition: The set $V$ containing all sums of the form
$\tag 1  \displaystyle{\sum_{i=1}^n q_i \alpha_i} \quad \text{where } q_i \in \Bbb Q$
is properly contained in $\Bbb R$.
Proof
Construct a family of finite subsets of $\Bbb Q$, $(F_k)_{\,k \in \Bbb N}$, such that
$\tag 2  \displaystyle{\bigcup_{\,k \in \Bbb N} F_k = \Bbb Q}  \; \text{ and }\; \{-1,+1\} \subset F_0 \; \text{ and } \; F_k \subset F_{k+1}$
Define the set $V_k$ to  be all sums of the form
$\tag 3  \displaystyle{\sum_{i=1}^n q_i \alpha_i} \quad \text{where } q_i \in F_k$
so that $V$ is the union of the $V_k$ family of sets with $V_k \subset V_{k+1}$.
We will construct a family of nested/shrinking closed intervals $I_m = [a_m, b_m]$ satisfying
$\quad \cap\, I_m = \{\beta\} \text{ where } \beta \notin V$
The nested interval theorem guarantees that the intersection of the closed intervals is a singleton $\beta$ while the algorithm constructing the $[a_m, b_m]$ must also take steps to exclude any element in $V$ from being in that intersection.
The algorithm (defined using recursion):
Set the initial closed interval to
$\quad I_0 := [a_0,b_0] := [-\alpha_1, +\alpha_1]$
Suppose $I_m := [a_m, b_m]$ has been set. There is a smallest $k$ such that
$\quad \frac{a_m+b_m}{2} \in V_k$
With that $k$,
if $m+1$ is odd set
$\quad a_{m+1} = \text{max}\big(\{v \in V_k \mid v \lt b_m\}\big)$
$\quad b_{m+1} = b_m$
if $m+1$ is even set
$\quad b_{m+1} = \text{min}\big(\{v \in V_k \mid v \gt a_m\}\big)$
$\quad a_{m+1} = a_m$
and define
$\quad I_{m+1} := [a_{m+1}, b_{m+1}]$
By the nested interval theorem the intersection of these intervals is a singleton set; call the element in that set $\beta$. Since every finite set $V_k$ gets 'consumed' by the algorithm,
$\quad$ for every $k$ we must have $\beta \notin V_k$.
and so $\beta \notin V$.
$\blacksquare$
Comment: Here is a quick (off-beat) way of showing  their are *irrational numbers*: 1) Construct $\Bbb R$ using, say, Dedekind cuts. $\quad$ 2) Prove the nested interval theorem. $\quad$ 3) Regard $\Bbb R$ as a vector space over $\Bbb Q$ and set $V$ to the vector subspace generated by $1$, and notice that $V = \Bbb Q$. $\quad$ 4) Invoke the above proposition.


Document Library View Filters

Question: I have a person/group field in a document library that contains multiple users.  Is there a way to set a filter in the library so that only those items that contain my name are displayed?
Answer: You can go to Modify View in the top ribbon and apply a filter on said column equal to [Me]. I used Created By below, but a person field will work also.
Answer: Set the filter in the view and select the person/group field and set the value to [Me]
Comment: Wow...that was easy.  I was thinking because there were multiple people that you had to somehow use the 'contains' operator.  Thank you.
Answer: How are the groups broken down? Do they have a delimiter ";" between each? Are they stored as an object?
may be overkill for what you require...BUT
in jQuery there is a selector called ":contains()" - perhaps with a custom view you are able to make a ajax call to retrieve these list items and store them in a variable. Then filter this variable where your field "contains('Your name')" and append to a table.
if you wanted the current logged on user to display where there own name is, you can simply make the following ajax call:
<code>let CurrentUserDisplayName

function GetCurrentUserInfo(){
$.ajax({
    url: 'https://**YOURSITE**/sites/**SITE**/_api/web/currentUser',
    type: 'GET',
    headers: {
        accept: 'application/json',
    },
    success: function(data){
        CurrentUserDisplayName = data.Title
        console.log(CurrentUserDisplayName);
    },
    error: function(data, errorCode, errorMessage){
        console.log(errorCode);
        console.log(errorMessage);
    }
})
</code>
}
from this you can create a table and filter the array where the field "contains(CurrentUserDisplayName)".
Hope this helps.

Document Library View Filters


SharePoint Daily Summary alert in Microsoft flow

Question: Is there any way to get SharePoint Daily Summary alert in Microsoft flow? Below image is an example of the daily summary(several items redacted because of security concerns). So far i have been able to recreate an email when changes happen but i am unable to identify exactly what changes like in SP alerts. any help would be greatly appreciated. more background: I need to only alert those people that are listed on the ticket to be notified of a change. since we do this so often we want it automated.
Answer: In SharePoint online list -  there is an in built notification MS Flow configured in each list or library.... in the ribbon area just next to MSflow and Powerapps.... you can try that.
Comment: while this works for notifications which i have set up currently. It does not identify exactly what has been changed. for example the alerts that are set up will show what the old sate was vs new state. the flow just states something has changed. this provides a bunch of false alerts since people click into the ticket to read and never change anything. also people sometime enter comments and sometimes dont. with our current set up from flows we just dont see what has chnaged.


What is the New Testament basis for capital punishment?

Question: It is evident that capital punishment is still in vogue in a few Catholic countries, despite the Pope having spoken in favour of abolishing of the penalty. I wish to know how the New Testament is interpreted to permit awarding of capital punishment for criminal offences like murder.
Answer: This passage of scripture immediately springs to mind:

1 Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. 2 Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves. 3 For rulers hold no terror for those who do right, but for those who do wrong. Do you want to be free from fear of the one in authority? Then do what is right and you will be commended. 4 For the one in authority is God's servant for your good. But if you do wrong, be afraid, for rulers do not bear the sword for no reason. They are God's servants, agents of wrath to bring punishment on the wrongdoer. - Romans 13:1-4 NIV [emphasis added]

Elicott comments on this latter verse thus:

It is clear from this passage that capital punishment is sanctioned by Scripture.

and Barnes:

It may be remarked that this verse is an "incidental" proof of the propriety of "capital punishment." The sword was undoubtedly an instrument for this purpose, and the apostle mentions its use without any remark of "disapprobation."
Answer: John Frame, in The Doctrine of the Christian Life (page 702), cites two New Testament passages to defend the practice of capital punishment.  The first, Romans 13, has already been addressed by bruised reed's answer – the "sword" of verse four is often interpreted to refer to the power to physically kill wrongdoers.
The other passage Frame mentions deals more explicitly with the death penalty, though not in a didactic setting.  In Acts 25:11, Paul addresses his accusers, saying:

If then I am a wrongdoer and have committed anything for which I deserve to die, I do not seek to escape death. [ESV]

Admittedly, Paul's focus here is arguing that he has done nothing wrong.
But nonetheless he does seem to accept the existence of capital punishment.


Ice-hockey forfeit goals

Question: I want to ask, in ice-hockey general or in NHL, if a game is forfeited before it starts or at score 0:0, the winning team automatically wins by 1:0. Is this one goal counted in teams statistics in goals for? And for the loosing team in goals against?
Thanks!
Answer: From the NHL Rulebook, Rule 66:

If the game is declared forfeited prior to its having commenced, the
score shall be recorded as 1-0 and no player shall be credited with
any personal statistics.
If the game was in progress at the time it is declared forfeited, the
score shall be recorded as zero for the loser and 1, or such greater
number of goals that had been scored by it, for the winner; however,
the players on both Clubs shall be credited with all personal statistics
earned up to the time the forfeit was declared.

The point of recording the score is to record it as a statistic, so the answer is yes - the winning and losing team are credited with that score, but no individual player statistic is, unless there was a partially completed game in which case those statistics still count for each player (even if the team score is changed).
Comment: What if the score is 1:3 for team A and then the game is forfeited such that team B is declared as winner. Will the score be 1:0? Then after sum of stats, goals, of team A players will be greater than total goals scored by the team A? It can be lower, if there was forfeit and no player scored, but can it be greater in this situation?
Comment: So goals from forfeit loss are counted for players but not for team?
Comment: @Rikib1999 Yes, the team result is 1:0, and the players will get the credit for all four of the goals that were scored.
Comment: Thanks a lot! :)

Ice-hockey forfeit goals


Recommended dhcpd Web Interfaces?

Question: Can anyone recommend a solid dhcpd web interface? Google searches turn up all kinds of results, including projects that haven't been updated since 2002. I'm looking for something that is a little more maintained and widely deployed.
Answer: Webmin can manage ISC dhcpd installations. You should check it out.
Answer: Have you tried PHPDHCPAdmin?
I agree that the currently available projects leave something to be desired. This is at least a little quicker then editing the config via command-line when I want to modify my giant collection of client's static IP assignments.

Recommended dhcpd Web Interfaces?


What do you call the plastic bit that mounts brake cable housing to dedicated frame mounting spots?

Question:
I lost a couple and have no idea what to search for online.
Comment: Looks like a "shim" to me.
Comment: Clarify please - this is for hydraulic hose as pictured, or for outers of cable-actuated lines?
Comment: Clarified the question. Was referring to brake cable housing. The picture is of 5mm brake cable housing, not a hydraulic hose.
Answer: Jagwire calls these "Hose Guide for Frame Loops".
I've also found these under "Cable Guide" on Amazon.
Answer: I just came across them at https://www.kineticbikebearings.com/kbb9038-slotted-cable-guide-pack-qty-20.html, called Slotted Cable Guides or slotted (wedge type) cable guide.
The term slotted might help disambiguate from other search results.
Answer: They are possibly called "cable clamps". For most frames that I've seen, they looked like this:

When lost, they are usually replaced by zip-ties, which are a better solution in the first place, from my perspective.
Your frame, however, looks to use a different type of clamps which act like inserts. From the picture it is hard to tell whether the regular U-shaped clamps will work for you. For them to work, you need matching holes in the cable stop/guide, e.g.:

A zip-tie around the tube will definitely work in your case, but it won't be equally aesthetically pleasing to look at, to be honest.
Comment: This is mainly a kind of housing 'widener'. The purpose is basically to prevent the housing from rattling in the retaining clamps. Other than that, it has no functional purpose. The ones on the second picture in the answer have the advantage of removing cable friction because of the free running cable.


How to export all the layers from Table of Content to shp file?

Question: I have got lots of different layers in the Table of Content panel in ArcMap. I want to export them all in shp format in one go. How can I do that? So far I have been doing it one by one by right clicking on the layer-->data-->export as shp. and it is taking longer time. I want to do them all together.
Comment: Even shape file has this capability that stores different types of shape(polygon,point,line,... all in same files) but ESRI doesn't use it,so you have to have at least one shape file for each geometry type of layers in TOC.Including different attribute sets of several layers is another challenge but if you let it slide and save only geometry field in each shape file,it's possible to do it by programming.
Comment: Sorry Reza if I misunderstood you, My problem is not storing different feature types in a same file. My problem is how can I export all the layers in shp format (could be point/line/polygon- however in my case all the selected layers are point feature type with X,Y coordinate) in one go?
Comment: For this I believe you will need to find/write a Python/ArcPy script. There is one [here](http://gis.stackexchange.com/questions/31462/export-each-layer-in-map-to-a-separate-image) but it converts raster layers to images so you would need to modify it to do vector layers to shapefiles.
Answer:
This could easily be converted into a toolbox script or run directly from the python window in Arcmap. It can be improved by validating the layer name before copying, duplicate naming conventions, drilling into group layers, using different data frames, etc.
But this should get you started for a simple TOC:
import os, arcpy

folder = "path\to\folder"

#Get name of vector layers in the TOC
mxd = arcpy.mapping.MapDocument("current")
df = arcpy.mapping.ListDataFrames(mxd)[0]
layers = [f.name for f in arcpy.mapping.ListLayers(mxd, "*", df) if f.isFeatureLayer]

for layer in layers:
    #Join output folder to layer name and append .shp
    shp_out = os.path.join(folder, "{}.shp".format(layer))
    arcpy.CopyFeatures_management(layer, shp_out)

Comment: What a great argument for eschewing .NET/ArcObjects in favor of Python! Which code will you be able to read and use five years from now!
Answer: Sure,I understood the problem and only mentioned some complications in general case.But for a simple solution it is possible to write an ArcMap solution(sorry I don't know much about Python/ArcPy so I use C#) which only implements a command button and this button can be dragged into one ArcMap toolbar from ArcMap/Tools/Options.
In the Click event of this button this code opens shape file,start editing for it and then create a feature for all features in all layers which has point type geometries
public void OnClick()
{
   IWorkSpaceFactory ipShapeWF= new ShapefileWorkspaceFactoryClass();
   IWorkSpace ipShapeWS=ipShapeWF.OpenFromFile(@"C:\",0);
   IFeatureClass ipShapeFC=ipWS.OpenFeatureClass("MyShapeFileNameWithoutExtention");

   IWorkspaceEdit ipWE=(IWorkspaceEdit)ipShapeWS;
   ipWE.StartEditing(true);
   ipWE.StartEditOperation();

   UID uid = new UIDClass();
   uid.Value = "{E156D7E5-22AF-11D3-9F99-00C04F6BC78E}";
   //Suppose ipDoc is IMxDocument which has been initialized in OnCreate event
   IEnumLayer ipLayers = ipDoc.FocusMap.get_Layers(uid, true);
   Marshal.ReleaseComObject(uid);
   ipLayers.Reset();
   ILayer ipL;
   while ((ipL = ipLayers.Next()) != null)
   {
       if (!(ipL is IFeatureLayer))
                    continue;
       IFeatureLayer ipFL = ipL as IFeatureLayer;
       if (ipFL.FeatureClass.ShapeType != esriGeometryType.esriGeometryPoint)
                    continue;
       IFeatureCursor ipFU=ipFL.FeatureClass.Search(null,true);
       IFeature ipF;
       while((ipF=ipFU.NextFeature())!=null)
       {
           IPoint ipP=new PointClass();
           ipP.X=((IPoint)ipF.Shape).X;
           ipP.Y=((IPoint)ipF.Shape).Y;

           IFeature ipNewShapeFeature=ipShapeFC.NewFeature();
           ipNewShapeFeature.Shape=ipP;
           //We set geometry field,here is the place for setting any other common field in                 all layers
           ipNewShapeFeature.Store();
       }
       Marshal.ReleaesComObject(ipFU);
   }

   //All layers finished
   ipWE.StopEditOperation();
   ipWE.StopEditing(true);
   Marshal.ReleaseComObject(ipLayers);
}

I supposed you take care of matching coordinate systems in source and target and also I assumed there is a data member  in this class ipDoc of type IMxDocument which is initialized in OnCreate procedure of this class like this:
public void OnCreate(object hook)
{
   if (hook is IApplication)
   {
       IApplication ipApp = hook as IApplication;
       ipDoc = ipApp.Document as IMxDocument;
   }
}

Hope this helps event I could not put all class codes here.Using VS 2012,ArcGIS Desktop 10.2 .NET SDK,you can use ArcGIS project Wizard in Visual Studio to create this class.


Lennard-jones cut-off

Question: I am using a Lennard-Jones potential in a computer simulation and I was wondering if i should place a cut-off for low distances since the potential blows up quickly   making the calculations quite difficult.
I am trying to simulate basic molecules ( few atoms ) , calculating bonds stretching , bond angle bending and lennard-jones interactions and trying to minimize the total energy to get an optimal structure prediction .
Comment: Please describe the system you are trying to simulate. What exactly does 'blow up' refer to? If it is uncontrollably high energies, then you probably will not benefit at all from having a low value for the cut-off, since the energy from LJ-potential grows only when the intermolecular distances are small.
Comment: Still need more info:

Which forcefield are you using? If you are not using any general FF, then please point to the source where you are getting the parameter values.

Which simulator are you using, or are you doing the calculations yourself?

Which molecules are you trying to simulate? Are you simulating them in a solvent, or in vacuum? Do all of the particles have LJ-sites?

Also, please elaborate on the 'blowing up'. If you are using any standard MD software (GROMACS, DL_POLY etc.) you should be able to see which energy term(s) grow unphysically high.
Comment: I am building my own simple force field in python, using parameters from : https://github.com/labello/amberff/blob/master/gaffparams.py . I am doing all the calculations myself .I hope to simulate simple molecules in vacuum like hydrocarbons . I am programming everything from scratch including the optimization method , the Lennard-Jones term keeps getting very large
Comment: [LJ potentials](https://en.wikipedia.org/wiki/Lennard-Jones_potential) should get really large only if distances are small.
Maybe that's what you got?
Answer: It's hard/impossible to pinpoint the reason for your problems without seeing the  code and knowing which terms you use. If you feel like sharing it, then you should probably head over to Computational Science and make a post there.
A few general things come to mind:

Check that you have $\sigma$ and $\epsilon$ values inserted in the correct order.
Check the correctness of the combination rules you are using. It seems the force field you linked previously contains noncovalent terms from OPLS/AA. Make sure that the rest of the FF is compatible with OPLS/AA.
Check the units you are using, and make sure they are all the same. Probably won't make your simulation blow up, but it's still worth to take a look, especially if you are using parameters from different FFs.

Lennard-jones cut-off


Red text Highlight in IDA Pro

Question: Why do some command in IDA have red text highlight around them?
e.g.
Answer: According to HexRays IDA support, this means an error. In IDA help (press F1), under the Problems List header you have the list of possible problems encountered during analysis. In your case it seems to be BADSTACK, which means:

The value of the stack pointer at the end of the function is different
          from its value at the start of the function. [...] The most probable cause is that stack tracing has failed.

You will see each line causing this problem in the List of problems window.
The description how to fix this problem is included in the IDA help as well, below the problem description.

Red text Highlight in IDA Pro


Why are the top voted answers on top of the accepted answer when it was answered by the asker?

Question: Why is it that the top voted answer always appears on top if the accepted answer is created by the asker himself? Usually if the answer is accepted by the asker, it worked for him, so why wouldn't that be on top in this situation?
Comment: Is this because you answerd your own question here: https://askubuntu.com/questions/963667/how-can-i-change-the-font-of-the-top-bar-without-changing-the-shell-theme?answertab=votes#tab-top Don't put the accept in too high regaurd, it only means that it helped to OP the most, NOT that it is best. Highly voted answers are often better ones and people should not overlook votes for the accept, answers should help anyone who reads them. As this happened only an hour ago, wait for votes.
Comment: @MarkKirby Isn't that the answer rather than a comment to the question?
Comment: @MarkKirby we are waiting for that answer!
Comment: @MarkKirby But I think OP has a valid point here. I would expect a uniform behaviour in this scenario. What could be the rationale behind placing the accepted answers at the top when they're posted by others but not when posted by the askers themselves? In both the cases there's a chance of having another answer with higher score than that of the accepted answer.
Comment: Loosely related to [On what basis is the position of an answer decided?](https://meta.askubuntu.com/questions/16956/on-what-basis-is-the-position-of-an-answer-decided)
Answer: From Meta Stack Exchange:

Can I accept my own self-answer?
Yes; if you've self-answered your own question, you can mark your answer as the accepted answer. There are some differences, though, that exist in order to ensure everyone gets a fair shot at answering:

Accepting your own answer won't award you any reputation.
The question must be at least 48 hours old before you can accept a self-answer.
Self-answers that are accepted will never be pinned to the top.

"Self-answers that are accepted will never be pinned to the top."
This rule stays intact though there has been a recent change in the way answers are pinned (read this for more information: Unpinning the accepted answer from the top of the list of answers).
This rule also applies to Ask Ubuntu Meta (read this for more information: https://meta.askubuntu.com/a/19793).