Applying an overall project RAG (red, amber, green) status

Question: Although I prefer regular meetings, communication and updates as a method for informing the client of the project status; my client wants an overall RAG status for each of their projects. I was looking at an objective way of combining risks, issues and progress against milestones to do this. What method have/would people use(d) to do this?
Comment: I've been known to report things as "cyan" or "off-white" where there's no defined criteria...
Answer: The thing to remember about RAG status indicators is that 1) they're not objective, 2) they're different for every project, and 3) they're different for every company.
Before you set up the status report you need to find out what those indicators mean to your client. For some clients a 10% deviation from plan is Amber, and others it may be Red. It's going to be based quite a bit on their particular risk tolerance. The more significant the project is in terms of how it fits into their company, the more risk averse they're going to be, so they're indicators will trigger sooner.
As the PM, you're going to need to discuss this with them and find their tolerance levels to set up the status basis. From there, as you approach a change in status you'll need to keep their view in mind, and temper it with your experience to reassure and inform them.
Comment: I've started drafting something (at a high-level) along these lines: "The RAG status is calculated by factoring in progress against critical milestones, risk and issue status, and budget if applicable (actual vs forecast). Tolerances for each of these should be agreed at the start of the project. Tolerances define what is an acceptable milestone slippage, level of risk, outstanding issues, and budget over or under spend. After tolerances have been established the following definitions can be applied to determine the overall risk status."
Comment: Great starting point. Nice work.
Comment: +1 for discussing the tolerance levels. That's the key point using such flags.
Answer: We don't do RAG status updates for our stakeholders, but I have a Kanbanboard setup in Jira (attlasian calls this a rapid view) which tracks only issues tagged with "project_board". That way, stakeholder, not interested in the details, can have a simple highlevel overview of the project status.
For our team, we do storypoint estimation for tasks. If we compare our velocity whith the remaining storypoints and days, we have a good guess about being able to fullfill our commitment.
If I had to do a RAG report, I would base this on the storypoints and velocity. This covers your progress and issues somewhat, but I have no idea how to fold "risk" into the equation, sorry.
Answer: I think you can set RAG status for budget, schedule and scope. As already Trevor mentioned, agree with your client on a clear definition of your ranges. Also, take a look at the resolution of your status indicator: per project, per phase, per milestone...
Take into consideration that by applying such status indicator, you will need to be very strict on measuring the variables, otherwise you will end up with discussions like: "Is it amber or red? Can we say... orange?"


How to retrieve files from a Windows partition from Ubuntu desktop

Question: I'm new to Ubuntu/Linux and I'm thus not very used to working on it. I used to have a Windows 7 and currently I dual-boot. I'd like to change to only Ubuntu. But I don't want to lose any information. I have a lot of songs, movies, pics, etc. saved on my computer but I have no idea how to get it from my Ubuntu desktop. And will all this information be lost if I change to Ubuntu? (I have a LOT of stuff so using a hard disk, USB  is not an option.)
Comment: Does your system detect the Windows partition? If you're system detects the Windows partition you might be able to find it on the left of your file manager. Just click it to mount it and then you can copy the files to your home directory.
Comment: The Ubuntu Community Doc [Automatically Mounting Partitions](https://help.ubuntu.com/community/AutomaticallyMountPartitions) should tell you what you need to know.
Answer: One thing you should be able to do is go under
Places -> Name of your Drive -> Opposite Click -> Mount
and if it does mount you will then be able to access it, see what's on it just like you would be able to do in Windows. If that can happen then it's a simple matter of drag and drop.
If you cannot see it in your Ubuntu partition then you can use an external USB HD like a Western Digital backup drive or something like that and just copy all your files/folders to that external drive, then plug it in your Ubuntu partition and drag and drop it to that...other than that there really isn't any easy way of doing it...
Answer: it isn't clearly stated on which setup-variant you run your systems, but maybe you meant the following:
If you have had your 'Ubuntu' installed via the 'WUBI'-Installer, so set it up as a virtual partition, which is stored as one or more files inside the 'Windows'-Partition, then you can access the 'Windows'-contents through the 'host'-folder.
In Nautilus you find it in the tree view under 'File System', or by clicking the hard-disk-icon in the breadcrumb-selector topping the file-view where your files and folder-contents are shown (the main visual of nautilus).
As an alternative you can open up a terminal or use the keys [ALT]+[F2] to open up the run-command and there typing in > nautilus /
The slash represents the root of the 'File System' and therefore is the topmost point in all of your folder-tree-structure.
If it is not the case that you just can't see your 'Windows'-partition, because it is inside the 'host' to hinder you deleting files necessary for running Ubuntu, then you might want to check if, due to a update- or setup-failure the system doesn't perform ntfs-access.
To find out if your system supports windows-partition-reading you can start Synaptic or the Ubuntu Software Center and use the search field (positioned neat to the main menu) to look for 'ntfsprogs' or for 'libntfs' and make sure one of them is installed.
There are several more ways to perform all these tasks, so just take it as a hint.


If Jesus was Emmanuel why was he named Yeshua?

Question: It was foretold that a virgin shall give birth and the new born will be named Emmanuel then why was Jesus named "Yeshua". (Isaiah 7:10) Please explain...
Comment: Emmanuel is a title--not a name.  Emmanuel means "God with us".  Jesus was "God with us", the "King of Kings",  "Almighty God", "Wonderful Counselor", etc.--all of which are titles, not names.  We say "Mr. President", "Mr. Speaker", "Your Honor", etc., but these are titles, not names.
Comment: @Narnian:  I think the actual language in which the line was written might clear the picture a bit. May I gracefully ask what is your source of this idea that it's a title.
Comment: Welcome to C.SE, and not a bad first question!
Comment: Sounds like a question all its own, so I added it: http://christianity.stackexchange.com/questions/17709/why-is-the-term-immanuel-emmanuel-considered-to-be-a-title-rather-than-a-proper
Comment: In the original language, 'name' means more than in our common usage. It means name, but also authority, character, renown, or reputation, as in "he's making a name for himself". Emmanuel is indeed a name.
Answer: You are confusing titles with proper names.

Yesh'ua (Heb.) is rendered "Jesus" or "Joshua" today. It is his given name. It means "Jehovah Saves."
Christos (Greek) is a title translating the Hebrew "Messiah" or "Annointed One."  It highlights his annointed and special status.
Immanuel (Heb.) is a simple Hebrew construction that says "God is with us."  It is as much sign as name. It signifies that in coming to Earth, God has chosen to dwell among us.

It would be akin to asking "Why is Obama referred to as POTUS when his parents called him Barak and his friends call him Barry?"  Each title, name, and construct reveals more information about the identity of this man, or in the case of Jesus, this God who became Man and dwelt among us.
Answer: His whole title in Aramaic is actually " ישוע משחא בר אלהא אחדאיא ", or "Jesus the Messiah, the only Begotten Son of God", according to the Nicene creed written in Aramaic. It shows how God is with us in that respect.
Not only that, but the prophecies in Isaiah can be taken to mean qualities of the Messiah, literally being called (qarat shemo  וְקָרָ֥את  שְׁמ֖וֹ, or in Aramaic taqarai shemieh תקרי שמיה ), as in He will be called Immanuel, otherwise, it would have been "at shimo את שמו".
Also in this verse, the literal Hebrew and Aramaic both state that his name will be called, not that his name will be.
Isaiah 7:10

Therefore the Lord himself will give you a sign: The virgin will conceive and give birth to a son, and will call him Immanuel.

לָ֠כֵן  יִתֵּ֨ן  אֲדֹנָ֥י  ה֛וּא  לָכֶ֖ם  א֑וֹת  הִנֵּ֣ה  הָעַלְמָ֗ה  הָרָה֙  וְיֹלֶ֣דֶת  בֵּ֔ן  וְקָרָ֥את  שְׁמ֖וֹ  עִמָּ֥נוּ  אֵֽל

It's not directly "at shimo Immanual" it's "qarat shimo", or "called the name Emmanuel".
The Aramaic Targum and Hebrew text out the prophecy, showing it's what earlier Jews believed. It is as much a name as it is a title of Christ.
For a further understanding on how that works,  look at Gen 17:19.
Genesis 17:19

Then God said, "Yes, but your wife Sarah will bear you a son, and you will call him Isaac. I will establish my covenant with him as an ever lasting covenant for his descendants after him.

וַיֹּ֣אמֶר אֱלֹהִ֗ים אֲבָל֙ שָׂרָ֣ה אִשְׁתְּךָ֗ יֹלֶ֤דֶת לְךָ֙ בֵּ֔ן וְקָרָ֥אתָ אֶת־שְׁמֹ֖ו יִצְחָ֑ק וַהֲקִמֹתִ֨י אֶת־בְּרִיתִ֥י אִתֹּ֛ו
  לִבְרִ֥ית עֹולָ֖ם לְזַרְעֹ֥ו אַחֲרָֽיו׃

With the naming of Issac (Yitzhak). "w qarat at-shimo yitzkhaq  וְקָרָ֥אתָ  אֶת־  שְׁמ֖וֹ  יִצְחָ֑ק". The accusative is here to show that his name will be indeed Yitzkhak, while in Isaiah, the prophecy states that "qarat shimo Imanuel", no "at" at all (no pun intended).
This "at" particle, according to An Introduction to Biblical Hebrew Syntax
 By Bruce K. Waltke, Michael Patrick, it states on page 162, section 10.1

...the particle at is often used with the definite accusative

In this case, with Yitzkhak, it's definite because it's saying his (the name) will be Issac.
In Jesus' case, the name Imanuel does not directly refer to his name actual, but something he will be called. The same thing in Isaiah 9:6, there is no 'at' particle to show that it would be his actual name.
Isaiah 9:6

For to us a child is born, to us a son is given, and the government will be on his shoulders. And he will be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace.
-כִּי־יֶ֣לֶד יֻלַּד־לָ֗נוּ בֵּ֚ן נִתַּן־לָ֔נוּ וַתְּהִ֥י הַמִּשְׂרָ֖ה עַל־שִׁכְמֹ֑ו וַיִּקְרָ֨א שְׁמֹ֜ו פֶּ֠לֶא יֹועֵץ֙ אֵ֣ל גִּבֹּ֔ור אֲבִיעַ֖ד שַׂר־שָׁלֹֽום׃

Again, we only see וַיִּקְרָ֨א שְׁמֹ֜ו, and there is no אֶת־שְׁמֹ֖ו, or the direct prophecy that his name will be, as how Issac was named.
Comment: Nice information. +1. You might also be interested in our sister site, [Biblical Hermeneutics.](http://hermeneutics.stackexchange.com/) You certainly seem to have the knowledge that they are looking for over there.
Comment: @fredsbend, I've edited my answer to include the Nicene creed, and I added the complete bible verses in both Hebrew and English, and a source that explains the "at" case in Hebrew.
Answer:
John 1:1 (NIV) In the beginning was the Word, and the Word was with God, and the Word was God.
John 1:14 (NIV) The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who
  came from the Father, full of grace and truth.

Jesus Christ is the Word of God, who himself is God, who became flesh and made his dwelling among us, hence, the meaning, "God with us".

Isaiah 7:14 (NIV) Therefore the Lord himself will give you a sign: The
  virgin will conceive and give birth to a son, and will call him
  Immanuel.
Matthew 1:23 (NIV) "The virgin will conceive and give birth to a son,
  and they will call him Immanuel"(which means "God with us").

Notice here that Isaiah simply gave the name but Matthew gave us the meaning of the name Immanuel as "God with us". Isaiah also gave other names for the Messiah.

Isaiah 9:6 (NIV) For to us a child is born, to us a son is given,
  and the government will be on his shoulders. And he will be called
  Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace.

Since Immanuel was not the only name predicted by Isaiah, it has to do with the attributes of the Messiah. Literally, Jesus Christ is the meaning of Immanuel, God who dwelled among us, who became human, hence the title "Son of Man".

Matthew 26:63-64 (NIV) But Jesus remained silent. The high priest said
  to him, "I charge you under oath by the living God: Tell us if you are
  the Messiah, the Son of God." "You have said so," Jesus replied. "But
  I say to all of you: From now on you will see the Son of Man sitting
  at the right hand of the Mighty One and coming on the clouds of
  heaven."
Answer: Let me use verses from Old Testament and New Testament:

Isaiah 7:14 (NIV) - Therefore the Lord himself will give you a sign: The virgin will conceive and give birth to a son, and will call him Immanuel.
Matthew 1:23 (NIV) - "The virgin will conceive and give birth to a son, and they will call him Immanuel" (which means "God with us").

In Aramaic, it must be noted that Immanuel is written as "Ammanueil" (Aramaic form of Hebrew name "Immanuel").
In Matthew 1:25, we see the naming of the child which is "Yeshua" in Aramaic (in English "Jesus").
I believe Aramaic name "Yeshua" can mean "YA has equated." YA (in Aramaic OT and Aramaic NT) is the Aramaic form of Hebrew "YH" in "YHWH." Because of this, Hebrew name "Yehochanan" is "Yochanan" in Aramaic. Another example is Hebrew name "Yehonathan" is "Yonathan" in Aramaic. For Respect, "YA" is addressed as "MarYA" (Master YA) in Aramaic OT and Aramaic NT.
From what I learned, YA has equated (Yeshua) the mankind by becoming a human being. Through this, God is with us.
Comment: And what source supports your assertion that "'Yeshua' can mean 'Ya has equated.'"?
Comment: Ya has equated?
Comment: When I said "Equate", I meant "to make equal." By becoming a human being, Jesus Christ opened the door of salvation for both Jews and Gentiles. We all are one in Christ.
Comment: Check Wheeler Thackston's Book "Introduction to Syriac" ("Vocabulary" section).
Comment: I don't have access to that book. Just tell me the root verb meaning "equated" in your theory.
Comment: Shua means to agree. In aphel form of shua in Aramaic, it can mean to equate or to make agreeable. It depends on the context.
Comment: The Y roots to the Vav not the Yodh. The Yodh roots to the I as in the Greek Iota. The I became a J. Therefore more correctly the YHWH should be IEVE. For the H stems from the Chet and it's the E that stems from the Hey. The Vav roots the f u v w and y letters. Meaning IEFE IEUE IEVE not IEWE for that represents a double Vav and IEYE. Phonetically the final hey has its own sound like an a. Cheers
Answer: First let us understand this so called name Emmanuel

Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel. (Isaiah 7:14 NKJV)

Now upon closer examination of the Hebrew you will see that this name Emmanuel comes from two words.

עמנו אל

The First Word
Uses the Hebrew letters (Ayin - Mem - Nun - Vav), these letters represented through English characters (Omnu).
This word gets translated as "with us"
The Second Word
Uses the Hebrew letters (Aleph - Lamed), these letters represented through English characters (Al)
Al gets translated as God
with us God
If Jesus was Emmanuel why was Christ named Yeshua?
He wasn't named "Yeshua". Yeshua is so a translation attempt however it cannot be correct. The English Y stems from a Hebrew Vav not the Hebrew Yud.
The Prophet was to come in his Name

I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and He shall speak to them all that I command Him. 19 And it shall be that whoever will not hear My words, which He speaks in My name, I will require it of him.

It was foretold that a virgin shall give birth and the new born will be named Emmanuel then why was Jesus named "Yeshua". Please explain...
The poorly translated word Emmanuel means "With us God". The Father's name is so composed from the four Hebrew letters Yud Hey Vav Hey. However simplified often to two letters Yud Hey. Now to get the correct pronunciation we can refer to the rules of Hebrew pronunciation and the example given to use by the Greek usage of the name of Jesus.
The Beginning I to Iesou the Greek rendition of the holy name represents the Yud. Another way to pronounce a Yud is so yodh. The Greek Iota is so the same letter. That's how we got the English I. The letter J transformed from the letter I during the 1800s. It got its J sound through French influence in romantic dialect.
The Greek Epsilon represents the Hebrew Hey. Therefore the Je in the beginning of the name of Jesus actually represents the holy name for God. However in pronunciation the Greek ie can carry the sound of the letter i for the word "in".
The next Greek letter the sigma sounds like an S.
In Hebrew form of the name of Jesus the final letter is so the Ayin, a silent letter. So the name of the "I am" is so also "Is".
Also the holy name we find both with the aleph prefix and also the Yud prefix. So in most cases where it is so translated as Lord would mean "he am" not "I am" therefore more appropriate to English and the holy name "Be", for it also says Holy "Be" thy name, "he Is". - it is what it is, it will be what it will be, I am that I am. Amen (so Be it).
Comment: עמנו אל  = "God [is] with us". Pronominal suffixes attached to a preposition (עמנו) form the object of the preposition (= with us).  If it were a genitive/possessive pronoun ("our God"), it should be attached to the noun with which it is constructed, as @curiousdannii explained.
Comment: How do you justify translating עמנו as 'with our' rather than 'with us'? Shouldn't 'with our God' be עם אלנו?
Comment: Take a look at Hebrew Suffixes. The Hebrew word (Ayin - Mem) means "with". The suffix (Nun - Vav) signifies "our". Also the Aleph is so a Verb Prefix meaning "I will", adding the Qal Perfect "we" would disagree with Hebrew language rules. And we can know that the Aleph is so ment to be a prefix for the lack of the double Vav.
Comment: Aleph isn't a verb prefix *everywhere*!
Comment: Thanks for the patience, though I don't understand since my reference doesn't explain. I feel the edit can hold till understanding comes.


Automated testing for mobile applications

Question: I am looking for an application like selenium but for mobile devices such as android/IOS would anyone have any applications that would suit this description?
Answer: Have you looked at Appium? I haven't used it but I think it's pretty much selenium for native app testing.
http://appium.io/
Answer: Yes, if you are looking for tool similar to Selenium for mobile application testing, then you should go for 'Selendroid'
Refer   http://selendroid.io/
Selendroid is a test automation framework fully compatible with Selenium, that's why it is called as 'Selenium for Android'. It can be used on emulators and real devices and can be integrated as a node into the Selenium Grid for scaling and parallel testing.
You can also use the same for iOS mobile application testing with its iOS driver
http://ios-driver.github.io/ios-driver/
If you are interested in paid tools then you can also try

Test Complete    http://smartbear.com/product/testcomplete/mobile-module/overview/
Test Studio http://www.telerik.com/teststudio
ExperiTest (supports even Blackberry and Windows)     https://experitest.com/automation/
Saucelabs   https://saucelabs.com/
Answer: I up-voted GKS1's answer because I have used Appium and it's great, once you get it setup.
I will also recommend Telerik Test Studio if you have the funding. It currently only supports iOS but Andorid is coming soon. A major benefit is that it uses physical machines rather than the XCode iOS Simulator. I have found minor differences in emulated devices compared to physical ones.


Apply a cluster(clustream) on a csv data

Question: I would like to train my cluster(clustream in my case) on a specific csv data and then test it on a diffrent csv test data.
here is my code:
<code>library("stream")
library("streamMOA")
library("RMOA")
setwd("baaa")
dsd <- DSD_ReadCSV("TRAIN.csv", k=NA, take=NULL, class=NULL, loop=FALSE,
               sep=",", header=TRUE, skip=0, colClasses = c("NULL",rep(NA,55)))
reset_stream(dsd)

# pay attention that t1 is a parameter set to 1
t1 <- 1
clustream <- DSC_CluStream(t=t1, m=100, k=23, horizon=500)
update(clustream, dsd, 55)

#start test:
</code>
the update(clustream, dsd, 55) not working well, this is the way to train the cluster on a data? and how could i test it? the meaning of "test it" is to get eventually the cluster id for each record in the test set.
thanks.
Answer: I also came across same problem for different data set, can i know the solution
cluster with CluStream
<code> stream <- DSD_ReadCSV("2c9b0cf998ef4370817f9f41d64fc0a0.csv",header = TRUE,sep=",")
clustream <- DSC_CluStream(m=50)
update(clustream, stream, 500)
Error in .jcall("StreamMOA", "V", "update", object$javaObj,.jarray(as.matrix(d),  :
</code>
method update with signature (Lmoa/clusterers/AbstractClusterer;[[Ljava.lang.String;)V not found


STM Lenses working for Canon Rebel T7/ Canon 2000D?

Question: I want to buy a lens for my new camera and everyone says that STM or USM Lenses are the best choices but also they said STM and USM lenses will not work for Canon Rebel T7/ 2000D !
is this correct?
Answer: No, it's not true.
I have the Canon EOS 2000D.
I also have a 50mm f/1.8 STM and great many other STM lenses. All of them work just fine.
I also happen to have one USM lens: 85mm f/1.8 USM. It works fine, too.
I agree that STM and USM lenses are the best, so you should consider only those. About the only non-STM non-USM lens today offered as new is the cheap kit lens.
There may be difference in focus speeds, but the main differences are the two main features of STM and USM lenses:

STM and USM lenses allow instant manual focus override
STM and USM lenses are much more quiet, being far more useful for video with autofocus

STM is manual focus by wire, USM allows direct manual focus which some people prefer. I found STM to be good enough for my uses (focusing to distant stars in astrophotography).
Usually (always?) STM and USM lenses have a non-rotating front element, meaning focusing doesn't mess up the orientation of your polarizing or  graduated neutral density filter, should you use one. At least my non-STM non-USM cheap kit lens has a rotating front element.
Related: Why do higher end lenses use USM instead of STM?
Also, if you want quick autofocus on your 2000D, you should prefer these modes in this order:

Shoot through the viewfinder.
Shoot using live view mode, but use quick mode autofocus. Note there's a slight interruption in the image as the mirror flips to use the phase detect autofocus sensor.
(least preferred): Shoot using live view mode, using non quick mode autofocus. Now there's no interruption in the image, but the autofocus is slow.

So, autofocusing speed is mainly dependent on how you use your camera.
Comment: Thank you for your quick response, how much difference in focus speed they have ? (STM vs Non STM) ?
Comment: @ArvinAtri That can only be answered on a lens+camera by lens+camera basis. Even the same lens can focus at different speeds on different bodies (mostly due to the difference in power available from one model to the next).
Comment: The same STM lens will sometimes focus faster in still imaging modes and slower/smoother in video mode.
Answer: As far as still imaging goes, all STM lenses should work on your Canon Rebel T7/2000D.
In terms of using continuous AF while shooting video, the Rebel T7/2000D lacks Dual Pixel CMOS AF that many higher Canon EOS models, including the Rebel T4i/650D and later models in that series, feature. It probably also lacks the capability to continuously focus with STM (or USM or non-USM/STM) lenses while shooting in video mode. That's where you may have gotten the idea that STM lenses don't work with the Rebel T7/2000D.


Uploading photos to facebook, Facebook App or Facebook Connect?

Question: I am working on a website that allows people to upload photos to their facebook account (as if the user manually uploaded those photos to facebook), and the uploaded photos will be hosted on facebook instead of my server. Should I develop a facebook application or use facebook connect?
Answer: When you use facebook connect, you actually create a facebook application that will make it possible to "communicate" with facebook from your website.
You should know that a facebook application runs in facebook while facebook connect gives you the possibility to link whatever you have in your website to Facebook.
Though, I'm not sure if what you want to do is doable using the Facebook connect API.


Can I apply for a Schengen visa at a country where I'm not a citizen? If so, under what conditions?

Question: I'm a citizen of country A who would like to apply for a Schengen visa at a consulate in country B. When is this possible?
Comment: You could be a legal resident of another country than your citizenship, and apply from there.
Answer: Generally you must apply for a Schengen visa from the embassy or consulate serving the place of your residence. This is not necessarily the country of your nationality; if you are in a third country on a long stay visa such as a student or work visa, then you are a resident of that third country.
The regulations do contain an exception, though.
Regulation (EC) No 810/2009 states:

An application shall be examined and decided on by the consulate of the competent Member State in whose jurisdiction the applicant legally resides.
A consulate of the competent Member State shall examine and decide on an application lodged by a third-country national legally present but not residing in its jurisdiction, if the applicant has provided justification for lodging the application at that consulate.

Therefore, if you can convince the consulate that you have a very good reason for applying elsewhere than your residence, then they may accept and process the application.
Comment: (+1) Mentioning the number of the article would seem necessary to properly quote the Visa code.
Comment: If the citation is wrong or incomplete, please feel free to fix it.
Answer: I've applied and was always granted many Schengen visas far away from home country.
They usually just want you to show that you'll likely leave their country and that you have the means to support yourself while there (last bank statement showing some money and employer payment stub, employment letter).
One question that usually you have to answer is where you'll stay. I found the simplest way to answer that is to have a copy of hotel reservation and plane tickets (even if you cancel them next day 'cause your plans are not all set yet).
Comment: @pnuts it would also be helpful to know which Schengen consulates accepted the applications.  Their practice is not uniform.
Comment: I have successfully helped visitors apply for Schegen visas while visiting the UK.  This was at the French embassy but very long ago.  However, it was not easy.  Subsequently, I say: get your Schengen visa before you leave home.
Answer: We have come across this requirement.
My partner was on an interim work visa for one years which was about to expire as well as her passport.
She returned home and around the same time we were invited to a wedding. She applied locally in her country, and had about a month wait for an appointment.
During the wait she applied and interim visa for the country she was previously staying in, so could then legally return.
When she applied for the Schengen visa they wouldn't accept and said she should return to the country she was staying in even though it was the other side of the world, without compromise.
Comment: Ambassadors and consul-generals have wide discretionary powers in granting visas. You should have escalated the matter.
Comment: @greatone it hasn't been one for me.
Comment: @greatone while that is true, it is often not obvious how one would do that, especially with the third-party processors acting as gatekeepers.
Comment: @phoog Google is a good start.


How much should I expect to pay for a PHP webhosting Service?

Question: I recently purchased a domain name (GoDaddy).  After I finish developing the site, I was wondering how much I should expect to pay for a webhosting service?  In addition, I was wondering what are some good web hosting services?  Thanks in advance!
Answer: It depends on what you want. I think pretty much any host will offer PHP, and I think for basic shared hosting, it's almost universally $5/month.
I've had good experience with Bluehost, although all the usual caveats for Shared Hosting apply (relatively slow, not able to install your own programs, they'll kick you if you use too many resources).
If you don't want shared hosting, Linode is amazing, but it's probably more than you need (and $20/month is the minimum).
Also, I like NearlyFreeSpeech. It's pay for what you use, so it's generally much cheaper than any other option (since if you actually used $5 worth of resources each month, a shared hosting company would kick you anyway). Downsides: They don't offer CPanel and last time I checked, they don't do SSL either.


What happens to transaction once all the blocks are mined?

Question: Once all the bitcoin blocks are mined(21 million limit has been reached) then would calculating the nonce still be so power intensive since the reward at this point of time would only be the transaction fee cost . What are the reasons miners will continue to operate their huge power hogging machines ? Also what would happen to the speed of block creation? Right now it is difficulty which governs it. but once all blocks have been mined how fast would newer blocks be created at the same rate or much faster?
Answer: Note that there are not 21 million blocks but 21 million bitcoins generated through mining.  As for your specific questions, the difficulty of a block is independent of its reward so that would continue to match the hashing power of the network.  And the reason that people will continue to mine is, as you state in the question, because they will receive the transaction fees for their effort.
Comment: But right now people are kind of breaking even or generating very small profits even with the block reward and mining with transaction fees. Wont the miners begin to make loss once there is no reward and hence stop mining?
Comment: Not sure where you found that information, but the main pools are all doing pretty well right now.  If the value of bitcoins rises then the number of bitcoins needed in fees and/or mining reward decreases; certainly although the number of coins obtained for mining a block today is basically half what it was a year ago the value is significantly higher thanks to the exchange rate.  As the mining reward goes away transaction fees will tend toward whatever they have to be to keep the service running.


Backup keeps asking for Encryption Password while restoring

Question: I'm attempting to restore from a previous backup but the restore keeps asking me for an Encrypted Password. I enter what I want it to be but it shows up some thirty seconds later to ask again. Why is this?
Answer: Sounds like a bug?  File one at https://launchpad.net/deja-dup/+filebug, provide the logs it asks for, and I might be able to help.
One thing though is that you mention entering what you want the password to be?  When restoring, you should be entering the same password you used when originally backing up.
Comment: Ended up not using Deja-Dup and just digging out old externals and filling them up. I wish I had the time to dig into it but maybe someone will come across this.
Answer: I had the exact same symptoms. My solution was to dig through my records to find an old password I'd used on a previous backup (with Ubuntu One, not deja-dup directly), install ubuntu one on the destination (restore) machine, and then enter that old password during the restoration of that recent backup file. Filed a bug report https://bugs.launchpad.net/deja-dup/+bug/1035924 as suggested by @MichaelTerry
Answer: I'm in a big - holy $#^^@# i just lost a ton of files mess. I'm currently restoring some from ubuntu one and got this Encryption Password prompt. It really had me worried and I tried some of my old passwords and they didn't work. I just reset my ubuntu one password, i know that password was not in use when I created these backups. My brand new, just reset, password worked here - so it may not be some old password you set your backups with, try your current ubuntu one password.
(i'm sure you're over this issue, but google led me to this thread, so i hope it helps the next person)


How does insulin sensitivity affect weight loss?

Question: What is the relationship between insulin sensitivity and weight loss?
Answer: Insulin resistance and obesity are both symptoms of type 2 diabetes, although they also occur at a prediabetic stage, before the diabetes diagnostic criteria are met. Insulin resistance is highly predictive of diabetes. In the Bruneck study, less than 10% of the insulin resistant subjects had no other metabolic disorder. But still, the exact relationship between insulin resistance and obesity is unclear, as they could

have a common cause, or
one of them causes the other, or
be coupled in a positive feedback cycle, or
all of the above. But we know that they are highly correlated in untreated patients.

This is the prevalence of insulin resistance in adolescents from NHANES, with white circles denoting normal weight adolescents, black squares denoting overweight adolescents and black circles denoting obese adolescents.
For example, one of the theories for the progression to diabetes is that the capacity of the body's usual fat depots is overtaxed, leading to having too much fat where it does not belong (e.g. intraabdominal fat deposits), resulting in lipotoxicity and finally diabetes. This would be a potential argument for obesity leading to insulin resistance. A common cause could be searched e.g. in reduced incretin secretion or increased JNK activity. But given the difficulty of finding a clear mechanism, and the complexity of the pathways involved, the connection is probably multifactorial.
Weight loss is one of the goals in diabetes management. Exercise and dieting delay the progression of prediabetic stages to diabetes. They reduce both obesity and insulin resistance. So, to answer your question directly, if you had insulin resistance, and you managed to lose weight, it is very likely that your insulin sensitivity has increased.
The above assumes that the patient is not taking any metabolic treatment. If he is taking diabetes medications, their effect on insulin sensitivity and weight will be independent. Some medication classes like GLP 1 agonists will reduce both obesity and insulin related effects, as will bariatric surgery. Metformin will improve insulin sensitivity without affecting weight much, while the glitazones reduce insulin resistance but lead to weight gain.
Answer: People who have insulin resistance generally find it more difficult to attain and maintain a healthy weight.
If the person with insulin resistance is overweight (which is often the case), and if s/he succeeds in losing even a small amount of weight, s/he will generally see some immediate improvement in their insulin sensitivity and a lessening of symptoms (such as headache, yucky feeling, foggy feeling).
Reference: https://www.niddk.nih.gov/health-information/diabetes/types/prediabetes-insulin-resistance
A low-carb diet helped my insulin resistant son.


Does bitcoin have transaction fees?

Question: Does bitcoin have transaction fees when sending money from on wallet to another ? How much % is the fee ?
Comment: related: https://bitcoin.stackexchange.com/q/43154/5406
Answer: Yes, Bitcoin transactions have transaction fee. It is not proportional to amount of Bitcoins sent, but it is proportional to the size of transaction and it is measured in satoshi/byte. (10^8 Satoshi is 1 Bitcoin)
The fees changes from time to time because of market conditions. You can find a good idea of what fees to pay on this site https://bitcoinfees.21.co/.
Comment: 1 or 2$ fees is a bit misleading. In the community we speak about fees in Satoshi per byte. When mempool is down (as currently), you can create transactions with 10Satoshi/byte. See current status also here: https://bitcoinfees.21.co/, which tells you how much Satoshi/Byte you need, to get your transaction through the next block(s).
Comment: Nice link. I will removed the 1-2$ reference with the link. I specifically mentioned market conditions to highlight that tx fee changes.

Does bitcoin have transaction fees?


VHT Pitbull 50-CL foot pedal?

Question: I'm the proud new owner of a used Pitbull 50-CL I got cheap at guitar center, but it didn't come with a footpedal. Now VHT is Freyette, I'm not sure where I could get one. Could I use something generic if I can't get the real deal?
Answer: Pitbulls come with two different types of control connectors for footswitch functions. If your Pitbull uses the standard 1/4" TR connector like this one does:

Then you can use any 1/4" TR type footswitch to control the amp's functions. You'll want latching switches.
Now if it has this DIN-style connector seen here:

Then you're probably better off just contacting Freyette. Sourcing the right plug and wiring up a switch for the functions will probably cost you as much as a new one straight from Freyette. Freyette is a good company and I'm sure they'll be able to help you source one either locally, or get you set up with one from their stock. They still use the DIN-style connector on their newest amps.

VHT Pitbull 50-CL foot pedal?


How long can a qubit exist without decoherence?

Question: In 2020, practically speaking, how long (time-wise) will a qubit function normally before decoherence kicks in?
Comment: @MohammadAthar: It is acutally $10^{18}$ seconds but it is still very long time.
Comment: according to https://en.wikipedia.org/wiki/Kane_quantum_computer , phosphorous qubits allegedly have decoherence times on the order of 10**18 years
Answer: On IBM Q, it is a few tens microseconds. The best value of dephasing time T2 is around 500 microseconds. Have a look here IBM Q website and navigate to "Qubits as physical system" and then to "dephasing T2" to see development of T2 in last twenty years.
Answer: Nuclear moments of europium ions have been experimentally measured to have coherence times of over six hours, although there is no currently known way of performing controlled logic gate operations on them.
Comment: I think these construction was intended for quantum RAM and future global quantum communication network.


How various 'Kavach Stotras' from Hindu Puranas can protect women from suffering molestation and other severe crimes?

Question: We come across various Kavachas or Armours of deities which claim that the one who reads them will be protected.
Nowadays we see the crimes against women are ever increasing.  Isn't it the right time to test these scriptures? I feel we must print these kavachas and distribute them to various women activists and women welfare groups. Is it practical? How can we who love Hinduism and aware of it's glory save women from the horrible sufferings of brutal crimes happening these days?
Comment: Probably they will.. because in Kavachas the deities are requested to protect various body parts of the chanter.. So let them try and see the results for themselves..
Comment: Very good Q and thought. I'd like to know the answer too. However, I do know that women do not have adhikara to chant many kavachas. They may chant raksha stotrams, chant rama nama ,tulasi kavacham. Again, bravo. Let's reopen.
Comment: Women do possess right to read kavachas. In fact the Hanuman Kavach was written and then taught to Seeta by Rama. There is Narayan Kavach in which various Avataras of lord Vishnu are requested to protect the devotee. If women start reciting any of the  Kavachas like Hanuman Kavacha, they might get protected by it's positive and protective effect. Not necessary that lord Hanuman will come personally to save the woman devotee but something will happen and the devotee will be saved. The problem is that most of the Hindu people do not beleive in power of scriptures, due to mostly ignorance.
Answer: Kavachas are special kind of stotras or hymns in tantric tradition which have a specific purpose of protection.
It is for everyone not only for women or men. It is a great way to protect oneself from negative forces.
Devi kavacham of durga sapta shati is a very famous among the kavachas. Apart from this there are many other kavachas. Also there are kavachas related to vaishnava deities like sudarshana kavacha, narayana kavacha etc.
In kavacha, various organs both physical and astral body and mind are being protected by various deities. It is adviced that one should generally chant the kavachas for overall.protection once a day.
Apart from kavachas there are also hymns called hridayam which are also useful along with kavachas for nourishment.
Comment: @Deepeshkumar but this stotra is not core part of the sapta shati and its for protection so.cant be misused. You can do it along with stotras such as Aditya hridayam.
Comment: Good answer. :) I have heard that Durga Saptashati is Kilit by Lord Shankara to prevent one from misusing it.
Answer: Perhaps we should be distributing the scriptures to men,

The daughter, O king, has been ordained in the scriptures to be equal to the son.

—Mahabharata 13.47.26

Where women are worshipped, there the Gods are delighted. But where they are not worshipped, all religious ceremonies become futile.

—Mahabharata 13.45.5

If a man has intercourse with an unmarried woman, who consents to it, it is no offense, but he shall deck her with ornaments, worship her, and thus bring her to his house as his bride.

—Nāradasmṛti 13.71-72
Comment: That was a nice suggestion. But I am specifically talking about use of Kavachas to protect women from undergoing heinous crimes.


Raspbian Kernel panic after RTC module .ko - How to unload modules at boot time?

Question: I am playing with the RasClock RTC module.
After baking my own rtc-pcf2127a.ko, and following the tutorial from the website, I got a kernel panic when booting (Null pointer etc.)
Could not find any decent emergency plan to recover my Raspbian, config.txt or cmdline.txt wouldn't help here, would they?
How to disable a stalling .ko or enable emergency shell to sort things out?
Thanks.
BR
Answer: Here's two methods you can try; both require you edit files on the SD card.
Blacklist via cmdline.txt:
You can add an instruction to /boot/cmdline.txt.  /boot is actually the first, small vfat partition on the SD card.  Mount that somewhere and add to the beginning of the text in cmdline.txt:
modprobe.blacklist=rtc-pcf2127a

It doesn't have to be at the beginning, but don't add a line break anywhere.   That file should contain one line only, it doesn't matter how long it is.
Blacklist via a modprobe .conf file
The preferred method for blacklisting is to add a line to a .conf file in /etc/modprobe.d (on the second, ext4 partition).
blacklist rtc-pcf2127a

And/or
install rtc-pcf2127a /bin/false

The last is needed if some other module depends on it, since blacklisting is not enough to prevent loading of dependencies.  You can create a new file in that directory if you want, make sure to use the .conf suffix.
A possible issue with this method is you may have to run depmod -ae afterward to make it effective, meaning you'll have to use the cmdline.txt method first, to get the system running.  I'd try this one first (without being able to call depmod, obviously) just to see.


Can an employer require employees to be COVID-19 tested at their own expense?

Question: In this case, the employer is a medium-sized ENT office. Some employees are young single mothers who don't have the resources to comply with this. The question also applies to non-medical employers, of course.
Answer: Depends on your definition of "require".
In case of at-will employment — where the employer can fire an employee for any or no reason (other than that being discrimination of a member of the protected groups) — it would be perfectly legal for the employer to fire an employee who does not comply with that request.
But that aside, no (unless such testing was a term of the employment agreement, be it written or verbal). No party to a contract can require the other party to perform what the contract terms did not include.
Comment: Thanks for this response.  In a right-to-work state I would guess that at-will employment is not assumed but would be stated specifically in sign-on documents, but I'm not sure. This question may have been better phrased as 'if an employer has received a covid-19 SBA loan,  can they require covid-19 employee testing to be done at employee's expense'.  I have a feeling that 'rules' concerning covid-19 responses are changing daily.


How can I customise the display of an event's associated images?

Question: In an event, how can I make the picture big enough to be more like a background in the body. I have tried making the pixels larger.
Answer: This is really a CSS question, but you can slice it several ways. All solutions will require a bit of understanding or expertise.

CSS only: You could add CSS to a custom site theme which sets the event background based on the event ID. (For example, the event info page contains a region with class <code>.crm-event-id-3</code> you could target.) This may be less flexible if you don't want to make image changes in your CSS, but it is fine if you can set-and-forget, or don't mind changing text files. This is what I'd typically do - I find CSS an effective tool.
Smarty, CSS via Custom TPL: Depending on your needs, you might find you want to use Event information to set CSS inline (eg, if you wanted to be able to use CiviCRM to change images via the web UI). To achieve this you might provide custom templates for CiviCRM. Documentation is at Customize Built-in, Profile, Contribution and Event Registration Screens and Page Templates. Note that the first page there recommends the next method! I would avoid this because working with Smarty makes me sad, and for backgrounds you'll end up working in CSS anyway.
Smarty, CSS via Extension: The docs above recommend using an extension to customise the Smarty templates or inject custom CSS. This is the "new" means to achieve the above, but may have a higher barrier to entry. It is better to maintain. I'd do this if, for example, client request was "make it possible for staff to change background per event". I'd still avoid Smarty and just inject CSS to the page.

Three options there! How you deliver this really depends on what your design requirements are, but I hope the pointers are some help.


How to setup Wordpress Pretty Permalink on shared IIS7 hosting with no url rewrite module installed

Question: I have setup Wordpress blog v2.9.2 on my website at location www.22shruti.com/blog/
(Shared IIS 7.0 Hosting (no admin rights on the server), PHP 5.2.13 FastCGI, WHB Operating System 2008, no url rewrite module installed.)
Since pretty permalinks are useful from SEO perspective, when I try to change the WP Permalink setting to a custom "/%year%/%monthnum%/%postname%/" via admin, I get following message on www.22shruti.com/blog/
"Not Found Sorry, but you are looking for something that isn't here."
What is the step by step solution to achieve the desired permalink format in this scenario? Help is much appreciated.
p.s. I contacted my hosting tech. support and the answer I have received is : "custom 404 url from our end is currently not possible as URL rewritng in Plesk panel is not allowed". Any other workaround / alternative in the given scenario? Thanks.
Answer: You might point the 404 error document to a specially crafted php file which will do mapping and redirection for you.
But since this would always return status 404 to clients there is no gain from a SEO perspective.
Comment: Thanks pacey. I contacted my hosting tech. support and the answer I have received is : "custom 404 url from our end is currently not possible as URL rewritng in Plesk panel is not allowed". So any other workaround / alternative in the given scenario? Thanks.


Make an outline with GIMP, like in Photoshop

Question: How do I add a stroke to a layer in GIMP?
Answer: Per the GIMP documentation Edit > Stroke Selection:

The Stroke Selection command strokes a selection in the image. There are two ways you can stroke the selection, either by using a paint tool or without using one. This means that the selection border, which is emphasized in the image with a dotted line, can be drawn with a stroke. There are various options which you can use to specify how this stroke should look.

Instructions

Create a new Layer
Make a Selection via Rectangle Select Tool

Go to Edit > Stroke Selection and setup your desired Line width:

Note: The stroke color is been taken from the current Foreground color.

Result
Comment: For hours on end I've been trying to add a border around a half elliptical pasted selection, and I can see that it has the dotted lines, so it is selected, but for the life of me I cannot put a border around just this selected half elliptical.


How can I fix a stored procedure (EDA_PUB_TARGET_ASSOCIATIONS_READ) which is negatively impacting adding items to the publish queue?

Question: While analyzing why adding items to the publish queue is taking so long, I discovered that the stored procedure EDA_PUBLICATION_TARGETS_READ is called for every item added to the queue, and can sometimes take 4-6 seconds to execute. I took a look at the execution plan, and 98% of the query cost is being spent on another stored procedure being called, EDA_PUB_TARGET_ASSOCIATIONS_READ. Since our implementation has over 800 publications, sending an item to all child publications can become extremely time consuming. Things have also gotten worse over time as we've added publications. I feel that the performance of this stored procedure is unacceptable. We run sp_updatestats regularly and make sure that the indexes aren't too fragmented. Any suggestions for fixing this stored procedure?
Answer: The stored procedures are part of black box code and should not be modified by anyone other than R&D and Support.  Hence it would be most appropriate to address this question to SDL Tridion Support, not folks on this forum.  My suggestion is for you to open up a ticket and give them as much detail about your configuration and DB spec as possible.  If you convince Support that the code is indeed inefficient, then they are very likely issue you a hotfix.
Answer: I would say that it is great you did some performance metrics on the database and suggest to send this data to Tridion Customer Support.  You have a very large dataset, maybe one of the largest, who knows.  In the past it's not just the amount of Publications you have, but also the complexity of parent-child relationships that adds to the amount of time needed for publishing.  So, by sending your data to customer support and working closely with them, there's a good chance the performance would be improved for all customers.
If you modify your database, the biggest risk is that something breaks and customer support and R&D won't be able to reproduce your error message or offer a fix.  Officially, they would say you are not supported, since your DB is a modified one.
However, if it is a very isolated change, and is possible to rollback to the original state very quickly (like if something goes wrong and CS needs to help) then I would say go ahead and make a very special exception for this case.  I would also review and test the rollback to the original SPs and make sure it is easy and possible.
It is also important that this is well documented on your end and your DBs are very familiar with how to put the old SP back in case an issue is reported to Customer Support.  But, sounds like the potential gain is worth it.  And, you're not doing the worst thing, which is modifying the data itself in the DB.  That is really really bad, since the data could become corrupt, etc.  But, improving a read-only Stored Procedure has fewer side effects, especially in the scope of the publish queue.
Answer: For an Oracle database, you will very likely be asked by Support to supply the AWR report including execution plans for that and associated procedures.
For a SQL Server database,  you will be asked to supply the SQL Server trace generated during the time you were adding items to the queue and noticed this behavior.
Your DBAs should also take a look and note anything unusual they want to point out.
Answer: Well one obvious, but perhaps unattractive, answer is to reduce the number of publications. The big question here, of course is do you use them all, and are they all in the same blueprint?
800 is a lot. Let's see - there's only 200 or so countries in the world. Maybe you are running several big blueprint master chains all in the same Tridion instance. If you are, you might consider splitting them out to two or more instances. There'd probably be other benefits from doing this too.


Is there an accurate online IQ test for measuring 160+ IQs?

Question: Is there some (preferably free) online and accurate IQ test?
One which does not give me an genius IQ and then tries to sell me a diploma.
I need one which measures upto 160 sd15 (or higher). Such a test would probably document its norming process somehow.
Comment: Also see [this question that asked about a free public domain IQ test with norms](http://cogsci.stackexchange.com/questions/199/free-online-intelligence-test-with-norm-table-high-reliability-and-must-be-pri?lq=1)
Comment: Also see this [previous question about how to measure very high IQs](http://cogsci.stackexchange.com/questions/3400/how-can-psychometry-measure-the-very-high-iqs-in-adults)
Comment: Just a note on IQ.  It is not a true measure of 'intelligence' anyway, but more of 'symbolic logic'. Intelligence is something that can not be measured accurately, although inventions such as the 'IQ Test' do make a very strong attempt.
Comment: The short answer is no. Most online IQ tests are only there to inflate your score, then convince the gullible to buy some certificate or course or some nonsense with a price as inflated as the test score. King of the Hill captured this in an episode that had Peggy shell out $1000 to be a "certified genius" complete with getting a phony degree from The Genius Academy." The paper printed to claim that would have been worth way more money. They are looking to make you feel really great, to sell you something really worthless because the high you're riding makes an easy mark of you.
Answer: There are at least two problems with measuring high intelligence:
(1) Any IQ test has a maximum difficulty. That means that all subjects above a certain intelligence answer all questions correctly and get the same maximum score. This is called the "ceiling effect".
Now you might say, that we simply need to construct a test that is difficult enough for even the most intelligent person to make some mistakes.
(2) The problem with special "high IQ" tests is that you cannot draw a large enough sample to norm this test. An IQ score is not an absolute value, like height, where you measure from a zero point to a certain length and each length has a meaning in itself in relation to that zero point. IQ does not have a zero point (there is no measurable total absence of intelligence), and the values of an IQ test are defined in relation to the average intelligence of the population that person comes from.
To norm a test, it is applied to a large sample of the population, and the mean and the shape of the distribution are calculated. The mean is defined as 100, the distribution is defined by the standard deviation, which for an IQ test is 15. The norming is done for different countries and at different times. This also means, that you cannot compare an IQ score from France to one from Spain, and that you cannot compare an IQ score from 1950 to one from 2007, at least not without some mathematical trickery similar to calculating the temperature in Centigrade from one given in Fahrenheit.
Now, since there are very few very intelligent people, even if all of them took the test your sample would be too small to reliably calculate a mean and the distribution. (And you couldn't test any of them ever again, because they already took the test and know the questions.)
Finally, you wouldn't know how the scores from this test relate to scores from other tests. In an IQ test with which you test the whole population, the average is set to be 100. Since all different IQ tests are normed for the whole population, you can set all their means at 100 and compare their scores. For a test that tests only a non-average subset of the population, like very intelligent people, the average must be somewhere else, because of course highly intelligent people are not of average intelligence. But where do you set it in relation to the 100 of the average population? You would need their scores from a normal IQ test to calculate this, but (now the circle closes) since a normal IQ test cannot measure them due to the ceiling effect, you don't know where they are in relation to the average IQ of 100.
Conclusion:
While you can create an intelligence test to measure the intelligence of highly intelligent people, this test will not give you a result that has any meaning in relation to the IQ, so in fact it is not an IQ test.
IQ is not intelligence (a trait), but a construct. IQ is what is measured by an IQ test, as the saying goes. A high intelligence test measures a different construct.
Comment: @z457731 That was covered in the reply by Jensen RCM. I'll try again: In the middle IQ ranges (average IQ around 100) there are many millions of people that you can test. From these results, you calculate the difficulty of your questions. This is important: the difficulty is not a factum that exists independent of the population. You need to test people to know how difficult a question is. To simplify the process, the difficulty is the number of people who cannot answer the question (from your test subjects). [contd.]
Comment: [contd.] For extremely difficult questions there might not be anyone among your subjects who can answer this question. So you don't know its difficulty. From your standpoint, all the questions that no-one could answer, are equally difficult (i.e. impossible) to answer. Or you might have one subject who has an IQ of 180, and he can answer all these difficult questions. Since only he can answer these questions, they appear equally difficult. [contd.]
Comment: [contd.] You don't know if there would be someone with IQ 160, who can answer only some of these very difficult questions. On top of that is the problem, that you don't know if a right or wrong answer was due to knowledge or guesswork. That person that had all those difficult questions right might just have had a lucky day. While is becomes less and less likely, the more correct answers he give, we don't know which ones he guessed, and even unlikely events do happen. That is what Jensen RCM means with "noise": the more difficult the questions, the less accurate the scaling of the difficulty.
Comment: I dont see the problem, IQ testing in the normal range upto 140 is very successfull, for higher range, all you need is harder items and a larger sample. IQ testing has existed for over 50 years and norming has been done on millions. There exist many offline administered tests that measures upto 170 or higher.
Answer: What you are asking for does not really exist, no serious IQ test would ever give a score of 160.
IQ scores get swamped with noise more than ~30 points from the mean.
For example, an IQ of 160 means you are are more intelligent than 99.996% percent of people while an IQ of 150 means you are more intelligent than 99.957% of people. No test could claim to measure that difference with a strait face.
Comment: Why is that? Do you also think it would be hard to figure out if a person is higher then 99.9957% of people on earth? Or that he is richer then 99.9998% of people in his country?
Comment: @z457731 A psychological test does not give the "true value" of a psychological trait. Psychological traits cannot be measured directly like lengths, they must be inferred from their effects. The result from an IQ test means that your IQ probably lies somewhere close to that number. The exact probability is reflected in the reliability of the test; the range of where the true value might lie is defined by the standard deviation (which is 15 points). For example, results from 85 to 115 are all interpreted as reflecting "average intelligence". No finer distinction is supported by such a test.
Comment: [contd.] For a finer distinction, it would be necessary to repeatedly test the same person with the same test and calculate an average result. This is impossible, because you can only apply an IQ test once, because the next time the test subject will have learned many of the answers. The same is actually true in physics. For acurate measurement, you need to repeat the measuring and calculate the mean. But measuring a length or weight can be repeated indefinitely without falsifying the results, since there is no learning effect on the part of a scale or yardstick.
Answer: To add to the existing answers (of which @what's gets special mention), an issue I don't think has really been addressed is the statistical reason for it being so difficult to measure extremely high IQs.
By design, IQ is scaled so that it's normally distributed, with a mean of 100, and a standard deviation (SD) of 15.
A well known feature of the normal distribution is that 68% of values are within one SD of the mean, 95% within 2, and 99.75 within 3. This means that only .03% of IQ scores are more than 3 SDs from the mean: above $100 + 15*3 = 145$, or below $100 - 15*3 = 55$.
It's even more unusual to find values over 160 (4 SDs) or under 40, with 99.993% of IQs being within this range. This means that only .0035% of people are likely to have IQs over 160. If you normed your IQ test on a sample of 1 million people (which is obviously totally unrealistic), you would only find ~30 with a 160+ IQ, rendering it impossible to accurately estimate a single individuals IQ in that range.

Simulated distribution of IQ for a population of 7 million (1/1000 the global population). Vertical lines indicate standard deviations (15 points). In this simulation, 238 people have IQs > 160.
Answer: Have a look at the different High IQ societies here:
http://rationalwiki.org/wiki/High_IQ_society
The best societies to look at for 160+ are:

eximia high IQ society
Mega Society
GenerIQ Society
Giga Society (http://www.gigasociety.com/)

All of them have references to test (some of it is online).
For ease of access, here are the societies from top 5% onwards

Top 5% (95th percentile; 1/20; IQ 124 sd15, IQ 126 sd16): International High IQ Society
Top 2% (98th percentile; 1/50; IQ 130 sd15, IQ 132 sd16): Encefálica Society, High Potentials Society, Mensa International, Mysterium Society
Top 1% (99th percentile; 1/100; IQ 135 sd15, IQ 137 sd16): Intertel, Top One Percent Society
Top 0.7% (99.3rd percentile; 1/147; IQ 137 sd15): Sunesis Society(Defunct)
Top 0.5% (99.5th percentile; 1/200; IQ 139 sd15, IQ 141 sd16): Colloquy (Society), Poetic Genius Society[2]
Top 0.37% (99.63rd percentile; 1/270; IQ 140 sd15): Infinity International Society, HispanIQ International Society
Top 0.3% (99.7th percentile; 3/1000; IQ 141 sd15, IQ 144 sd16): Cerebrals Society
Top 0.2% (99.8th percentile; 1/500; IQ 143 sd15, IQ 146 sd16): exactiq high IQ society
Top 0.13% (99.87th percentile; 13/10000; IQ 145 sd15, IQ 148 sd16): CIVIQ Society
Top 0.1% (99.9th percentile; 1/1000; IQ 146 sd15, IQ 149 sd16): Glia Society, International High IQ Society Milenija, International Society for Philosophical Enquiry, Iquadrivium Society[2], One-in-a-Thousand Society[2], Triple Nine Society
Top 0.003% (99.997th percentile; 3/100000; IQ 160 sd15, IQ 164 sd16): Prometheus Society, Tetra Society
Top 0.001% (99.999th percentile, 1/100000; IQ 164 sd 15, IQ 168 sd 16): eximia high IQ society, The Ultranet[3]
Top 0.0001% (99.9999th percentile; 1/1000000; IQ 172 sd15, IQ 176 sd16): Mega Society, GenerIQ Society
Top 0.0000001% (99.9999999th percentile; 1/1,000,000,000; IQ 190 sd15, IQ 196 sd16): Giga Society
Comment: So if you would test the whole mankind, you would not only FIND 7 or 8 with 190 or higher, but you must find exactly 7/8 due the IQ is a relative value, not a fix number. It's not possible to have more than 8 IQ190+ people in <8.000.000.000, so it's impossible to have less then 7 IQ190+ in >7.000.000.000.
Comment: You are absolutely right @Sempie. It is all relative, although it's not reflected like that in reality. If you would have taken a test today, they should really let you know every year how they have adjusted that number ... so your IQ should really fluctuate (slightly), depending on how others rate in their new IQ tests.
Answer: The oldest and largest high IQ society in the world is Mensa.  They offer membership only to those who have an IQ in the top 2%.  They administer their own test to qualify those who seek membership.
There are also online IQ tests that claim to be Mensa IQ tests, but I am unsure of their validity.  However, Mensa only recognize the results of tests that they personally supervise, so any online IQ test proclaiming you a genius is just a novelty really, as online IQ tests are not recognized as having any special significance by any 3rd party.
If you are really serious about knowing how your IQ compares, I would suggest getting in contact with Mensa since they are the experts about that.
Comment: Mensa is *not* a psychometrics society, and I would not suggest asking them any question that should be directed to a psychometrics expert--they are a group of people with a certain range of test scores.
Comment: MENSA actually accepts several different tests, although they do administer their own. I personally got into MENSA based on some IQ test I took when I was ~8. At the very least, MENSA's list of accepted IQ tests would be useful: http://www.us.mensa.org/join/testscores/qualifyingscores/
Comment: I already took the (on-site) Mensa test. I scored in the top 10% of Mensa candidates (so top 10% of the top 2% of population). Therefore looking for more targeted tests.


What does it mean for a menu to be a "set menu"?

Question: I hope this question isn't too off topic. What does it mean for a restaurant to have a "set menu"? The one I have in mine has three headings wit the descriptions: "starters...assortment as brought to the table to share family style"; "mains...each guest will chose their own"; "desert"...assortment as brought to the table to share family style". How does this work? I'm guessing it means you choose one from each category, and no matter your selection the price is the same? What does the part about family style or choose your own mean?
Answer: Collins dictionary gives a nice definition for a set menu:

A complete meal in a restaurant or café for a stated price with a limited number of options to choose from for each course [...]

The different serving options are

family style:
Like you would probably serve food at the family dinner table: every component in its own serving bowl or platter, to be passed round amongst the diners. In a restaurant, often a nice platter of various dishes to be shared.
individually plated:
This is what you are probably expect first when dining in a restaurant - each diner gets his or her choosen dish on his or her own plate.

So for your case:
For n diners you build a menu out of n appetizers or starters that get served on one (or a few) platter(s) and is then shared. Of course you can choose n different options or stick to larger quantities of fewer choices.
The main dish comes on n individual plates according to each participant's order and the dessert is again n servings of whatever you pick, like for starters.
And yes, if that is described a set menu, you'll pay a fixed price per person, unless some options are marked with an extra charge, but that would have to be stated clearly on the menu.
You can of course build a menu à la carte instead, then you pick the individual dishes from the à la carte menu - these have individual prices that make up the total cost of the meal.
Answer: This sounds like a UK restaurant from the terminology in which case a set menu is a fixed-price number of courses with either no choices or a few options. A starter is an appetizer, and in this case it's a platter for the entire table to share. Mains is the main course, and you will have a choice of 2-3 options typically, then dessert is another shared platter.
The term menu is used different ways in different places. In France a menu is a fixed price list of what is being served in what order, the menu is set in other words. Ordering a la carte means you are ordering dishes off the set menu on offer. In most english speaking countries a menu is the list of food that can be ordered in a restaurant, some restaurants offer a set menu or a prix fixe (fixed price) menu which is the same thing as french menu.
Comment: @Celeritas It means that you are ordering a complete set, and cannot pick which courses you get.  In a normal situation, you can get 3 appetizers if that's what you want.  In prix fixe, you get one of each course listed.
Comment: This is what I red when searched it, but don't understand. Aren't all menus fixed price?
Comment: See my edits @Celeritas, I hope that explains it.


Learn the characters at the same time as the language?

Question: Should I learn Mandarin basics first through pinyin and worry about the characters later, or should I learn them together? Pros and cons?
Answer: There is a key difference between learning the language as a native speaker, and learning the language as a second language. Native speakers of all languages invariably learn speaking and listening skills first, and only start to learn reading and writing at school, after the age of about 3 or 4. Learning a language as a second language, reading and writing have more prominence and can expedite some of the learning, but this also depends on a person's 'learning style'. Generally, combining all four communication skills is better.
To clarify what I am trying to say, my own experience of learning Chinese (and other languages) mixes all four modalities (reading, writing, speaking, listening). I find that learning the characters sometimes gives insight into the relationships between words (the semantics), that are not obvious from how they are said. Sometimes the process works the other way, as I see patterns in the written characters that are reflected in the sound.
Answer: Here is the way how Chinese kids start learning Mandarin in school.
They first learn Pinyin, then learn simple and basic characters, like 人,口,手,天,大,我,你,他, etc.
Pinyin tells you how to pronounce new characters. So learn Pinyin first.
Comment: Which "school" are you referring to? Chinese is widely used throughout the world, and different countries usually have different ways of teaching Chinese.
Comment: @Pacerier By school, I meant elementary schools in Madarin speaking regions in China(PRC).
Answer: First, please don't entangle in learning Chinese pinyin and Chinese character at the same time or not.You need to ask yourself what is your purpose of learning Chinese?
If you only want to travel in China or learn some daily Chinese or make some Chinese friends, I recommend you to learn Chinese pinyin first. Many Chinese learners chose learn pinyin first,but notlearn Chinese pinyin and Chinese character together.
Because Chinese pinyin is a very easy part and even easier than English learning, and pinyin can help Chinese learners'pronounce. But Chinese characters is a very hard part in Chinese learning. HSK1 and HSK2 didn't appear characters. If you choose learn Chinese pinyin and Chinese character together, may be you will give up learning Chinese very fast.
And for Chinese beginners, only focus on Chinese listening and speaking is enough. If you are a kid or teenager,I recommend you learn Chinese pinyin and character together.You can spend more time to practice characters and you don't need to work.
Answer: Get started the easiest way (romanization, aka "pinyin", only) but once you've learnt a few basic sentences it's not a bad time to start learning characters.
You eventually want to be learning characters and pinyin at the same time anyway, so you might as well start as soon as you can. Much of the reward you will feel whilst learning is in being able to read bits and pieces here and there.
Answer: It also depends on whether English is your native language (I am assuming here it is for you).
If it is not, I would not recommend learning pinyin simultaneously as sometimes it just confuses you as to the sounds of the word. For example: while you continue to pronounce Q as queen in English, in Pinyin, you need to keep reminding yourself that "Q" is pronounced as "Ch" (Eg: Qing is pronounced as King)
One of my friends' native language is Hindi and he preferred writing the pronunciations in hindi, as hindi has characters for all those variations of the "chh" sound that cannot be distinctly expressed in English in daily language.
Even if English is your native language, you will have to do a lot of unlearning when you learn Pinyin. For example: Zh is pronounced differently (Eg: Zhong 中 is pronounced not as z-h-ong but rather "chong"). Ri 日 is not pronounced as "I-R" but rather as "R-I' keeping the tip of the tongue behind a palate producing a sound that is not usually used in English (Eg: Rizhao is rounounced as "Ir-zhao")
My personal experience has been that it is more instinctive to listen and imitate rather than go the Pinyin route. This needs a lot of practice (hence just keep saying the same words till you get it right). Keep Pinyin as your fall back reminder of what to say - as a trigger and not as the main mode of learning pronunciation. But others may have a different take based on their experiences.
Of course, I am assumming that you have native Chinese speakers around you who you can practice this with regularly. If not, you still can do so by listening to the sounds of the language through you tube or internet sites.
As for how Chinese students learn, what has been mentioned earlier is true, but do remember that (a) they hence face a similar problem later when they start to speak in English (they pronounce words differently initially) (b) They are not learning purely through Pinyin alone -  they learn Pinyin and Chinese along with the teacher simultaneously pronouncing these words (and hence start to associate Pinyin with certain sounds made by their teacher).
Do remember - While Pinyin was the only mode of learning to speak Chinese 20 years ago (cassettes and walkmen were not as easily available and portable as mp3), today it is not so. Mp3 availability makes learning and learning a practical easy possibility. For example, this lesson makes it easier for you to say "I can speak a little Chinese" than this lesson
Comment: "日 is not pronounced as "I-R" but rather as "R-I'" --> Is that what you meant to write? Seems backwards. By the way welcome to Stack Exchange!


How do I update DNS without causing an outage?

Question: If I change a computer's IP address, it can take a long time for ISP's to stop caching the results. Is there a way to mitigate this, if I plan ahead?
Answer: If we KNOW we will be moving an IP address, we turn down the TTLs for that record. That tells the DNS servers on the internet how long to keep that IP in cache. When we move it over, the rest of the 'net catches up fairly quickly. Once the move is done, we move the TTL's back to their normal value.
We did this a couple weeks back when we needed to change our MX record. It uses the same steps as an IP change. First, we lowered the TTLs for the MX records from 1 day to 5 minutes. We then waited 2 days for the change to propagate. We updated the MX records on our DNS servers, and within 10 minutes every client on our network was using the new data. Looking at mail logs, it took about 2-3 hours for the rest of the internet to catch up. Once the change was made, we then raised the TTLs back to their previous default.
Comment: How long does it take a TTL to propagate?
Comment: A change in TTL will, just like any other change, take (at most) old TTL to propegate.

Also note that many large ISP's put a lower limit of anywhere up to four hours on TTL (some did force 1 day, but I believe that's been stopped)
Answer: Probably the easiest way would be to add the new IP as a secondary IP on the box, then update the DNS record. After a week or so you should be safe to remove the old ip and make the secondary ip the primary address.
Answer: If you're just renumbering existing hardware, you can do as Zypher says and dual-address over the transition period.  If you're actually moving the services, though (say to a different hosting provider) you can use dual-NAT to redirect traffic to the old address to the new one.  This does pre-suppose either full control of the old hardware or a helpful hosting provider, and it messes with your IP access control/logging (all redirected connections will appear to come from the old address), but it's worked quite successfully for me several times when I've had to transition services between networks.


sediment at the bottom of brew

Question: I have just bought a Coopers DIY beer kit and have started my first ever brew. Ive notticed at the bottom of the fermenter there is a lot of sediment is this normal or have I done something wrong? Any help would be greatly appreciated.
Comment: By "brew" do you mean in the kettle, in the fermentor, or in the bottles?
Answer: A quick Google on the name tells me that this is an add water, sugar and yeast kit, so I am guessing you are referring to sediment in the fermentation bucket. In that case, the sediment is a perfectly normal part of the process. The yeast, which is doing its job of producing your alcohol, is multiplying, flocculating (clumping together) and settling out.
When it comes to bottling, don't disturb the sediment, just leave it behind in the bucket. Enjoy your brew, before you know it you'll be doing another!
Comment: "A quick Google on the name tells me that this is an add water, sugar and yeast kit..."  They're pretty popular down under.  They call it "Kit & Kilo" brewing - as in "start with this kit and add a kilo of sugar."
Comment: Assuming that the outlet for the tap is above the sediment level, then yes, just let it run clear before running into bottles. Don't open the tap too quickly in case the 'rush' disturbs the sediment. If it is covering the tap outlet you'd be better off siphoning into bottles.
Comment: Hi thanks for the help yes the sediment is in the fermentation bucket. It is also in the bottom of the tap but im hoping it will be pushed out when i open the tap should i drain some out before i start bottling. Thanks again.
Answer: If you plan on re-using the bottles you might want to spray out the sediment after you poor the beer in the glass. This will get the gunk out of there before it hardens and save you some work later.
Answer: Coopers is a nice brew - I used to drink it when I was in Melbourne. However, the tradition then was to roll the bottle to stir up the sediment and drink it. I could never taste the difference. However, I wouldn't advise that with your homebrew - it might taste a bit yeasty/bitter. Probably best to leave it in the bottom of your bottle!

sediment at the bottom of brew


Uninstall Ubuntu without access to uninstall file

Question: I tried to use the Windows add remove program to uninstall Ubuntu, but it says I dont have access to the uninstall-wubi.  which is apparantly on my H drive which windows doesnt even know exists.  is it possible to download an uninstall-wubi and use it
Comment: Isn't your real problem that you can't access your H drive from Windows? Which doesn't belong here on Askubuntu.
Comment: You can manually uninstall the bits that are left (just registry and boot entry, if you already removed `H:`): https://wiki.ubuntu.com/WubiGuide#How_do_I_manually_uninstall_Wubi.3F
Answer: Try to run Windows in an administrative-modus (Administrator) NOT as a user.
Try to repeat the nessecary steps for removing Ubuntu out of Windows: via add/remove software, select in the prompted window 'Ubuntu' and click to remove it.
Normaly Windows will ditch Ubuntu from it's system. (It takes for about 3 minutes or so)
If you have special Security software on your system, please check this software wether it allows you to install or remove software (these are all paid versions, so easy to check).


Third violation of Academic Integrity Policy

Question: Not sure if this happend to anyone, but it is my first I ever recieved this notice. I have this professor and like to be called Dr., who hasn't been very understanding. I've been turning my work in on time or sometimes a day late due my full time job. I've explained this to her in the past because I previously had this professor in my other class and she gave me a C and said I did plagiarism in the other class. Apparently, in this class, I have done plagiarism on my essays when in my perspective I've been citing every piece of sentence that I know I am paraphrasing and I add my references. How come I never received a first or second notice? Also, I don't understand why she did this when I know I cited every detail. The rest of my professors that I have had in the past has always given me As and Bs on my essays why this teacher is giving me these grades? I have another class with another professor and he is very understanding. I get As with him and he tells me I do a fabulous job. I just don't understand and now I have a conference with the faculty coordinator about how we are going to fix the issue when in my perspective I think I've been following the guidelines of citing my work.
Comment: hi! could you please clarify what exactly you need help with?
Comment: Have you been warned on plagiarism before? Note that quoting verbatim for extended sections is also considered a form of plagiarism, even if sources are mentioned. It is probably not as grave as not mentioning the sources, but it is still a serious problem, as verbatim quoting means you just copy/paste the thoughts of others and it is not clear to which extent you have understood what they are saying; it puts in doubt how much you actually have intellectually contributed. Generally, it is better to use your own words, even imperfect than copy the words of others.
Comment: If your essays read anything like this question I'd expect an automatic F. Plagiarism or not.
Answer: Maybe there is a misunderstanding about plagiarism here:
Plagiarism example:
There is considerable controversy about the mechanism of T cell receptor (TCR) triggering, the process by which the TCR tranduces signals across the plasma membrane after binding to its ligand (an agonist peptide complexed with an MHC molecule) [1].
(because you copy&paste the text without quotation marks - the citation does not fix it here)
No Plagiarism:
"There is considerable controversy about the mechanism of T cell receptor (TCR) triggering, the process by which the TCR tranduces signals across the plasma membrane after binding to its ligand (an agonist peptide complexed with an MHC molecule)" [1].
(because you cite and use quotation marks)
... and yes, it needs to be quotation marks. Using italic, indent or similar does not help as recent decisions about plagiarism in PhD theses have shown.
No Plagiarism:
The mechanisms that cause T-cell receptor triggering are still a matter of discussion [1].
(because you cite and rephrase and no quotation marks are needed - this is most common in natural and technical sciences)
[1] Correct citation here with authors, title, year, journal/book, pages etc
What can you do in your situation (i.e. when meeting with the faculty coordinator)?
Maybe your professor did not clearly point the above out (sounds like it from your text)? Then it was a misunderstanding. If you are an undergrad student this will most likely be an "honest mistake" - as a PhD student that line will not help you.
Comment: Could you please provide a reference for the decisions that "italic, indent, or similar does not help"? I'm interested in where these decisions were made, since they strike me as inordinately strict. I would have expected, before reading your answer, that what  is needed is only an absolutely clear indication that the words are taken unchanged from another source.
Comment: google Johannes Hahn
Comment: Thanks for the pointer to Johannes Hahn. If I correctly understand the paragraph about plagiarism on the Wikipedia page, Hahn was "acquitted" in the investigations performed by two universities but "convicted" in an investigation commissioned by a member of an opposing political party. I'm inclined to conjecture that whatever Hahn did would have been OK if he weren't a politician.
Comment: Think about it this way: If we had cited correctly then the first long pharagraph of his wiki page would now not be about his PhD thesis but about his work as European Commissioner ...
Answer: I think two things should be pointed out:

This professor has already warned you that you are doing "plagiarism in the other class". She's presumably taking that as the first or second notice.
Citing something doesn't necessarily mean there's no plagiarism. For example if I construct a paragraph where I quote verbatim from three different sources, even if I cite them all explicitly, that's still plagiarism. There's no hard and fast line, but if your work contains more direct quotations than your own words for example, that could lead your professor to conclude you plagiarized.

If you still think you didn't plagiarize, or if you are still not sure why this professor is accusing you of plagiarism, go to the meeting and explain your point of view. Note you haven't been found guilty and there's a chance the faculty coordinator doesn't know the full details (or wants to know your point of view). You'll be given the chance to defend yourself and it's possible the coordinator will agree with you. Either way, the meeting is an opportunity for everyone involved to solve this conflict like adults.
Comment: @sgf But the OP did not state that they made it clear they were citing (or paraphrasing), just that they referenced the source. Referencing a source is not itself enough if you are paraphrasing or quoting long sentences.
Comment: _if I construct a paragraph where I quote verbatim from three different sources, even if I cite them all explicitly, that's still plagiarism._ No, if you make clear what you're citing, it can't possibly be plagiarism. The problem with having paragraphs entirely made from other sources, if there is one, is that it makes the work too little original.
Comment: @TobiasKildetoft But Allure is explicitly saying "if your work contains more direct quotations than your own words [...], that could lead your professor to conclude you plagiarized" This doesn't sound like "if you didn't put quotation marks...", it sounds like "If 90% of your assignment is verbatim quotations, that's plagiarism", which is wrong.


Is any 40 character hex string a valid ethereum address?

Question: I know an ethereum address is generated by getting the last 20 bytes of the keccak-256 hash of the public key, which is 40 hex digits. I also know, an address does not need to have transactions associated to it to be valid, it just needs to have been generated by keccak-256. Does this mean any 40 character hex string is a valid address or are there some arrangements that keccak-256 will never generate?
Comment: Yes, quite similar I believe. Here it is: https://ethereum.stackexchange.com/q/64138/16043.
Comment: `keccak256` generates 64-hex digit hashes.
Comment: Indeed, but I believe you take the *last* 20 bytes of of the 32 bytes of data provided by keccak-256 to generate the address, correct?
Comment: AFAIK, keccak256 is said to cover the entire range of 256 bits, hence the entire range of 160 bits. Not sure that it has been proven though. I do recall asking a similar (perhaps even equivalent) question here. Let me see if I can find it.
Answer: Nobody can deliver a proof to an answer to that question. I'll try to explain why. The algorithm to create an address is as follows:
1) Generate private key k (slightly less than 2^256 keys, actually 2^256 - 4294968273 on curve secp256k1)
2) Derive public key P = (x,y) from k using elliptic curve scalar multiplication on curve secp256k1: P = G * k = G * ... * G (k times)
Note at this point your public key is 512 bit long, but not even nearly the whole number range is used, less than 2^256 points can be generated.
3) Hash concatenated x and y coordinates from P using keccak256 (mapping 512 bit to 256 bit)
4) Take the least-significant 160 bits from the hash, this is your address.
Until step 3 the answer can be proven. The Answer is no in that case, proof: Since we map less then 2^256 numbers to 2^256 numbers (non-surjective mapping), not every number in the target set (co-domain) can be hit. Step 4 makes everything unprovable though: We map less than 2^256 numbers inside a number range of 2^512 to 2^160 numbers. At first glance this mapping looks surjective and in that case we would answer yes. We don't know how the almost 2^256 numbers inside the number range of 2^512 are distributed. Even if we would know the distribution, we would still not know to which keccak hash those numbers are mapped. The only way to prove it is to brute force all public keys, one by one, caclculate the keccak hash and from it the address, look up if we stored it already, store it if it is not stored yet and stop when we finally hit every number in the 160 bit range or when we tried every public key available.
This answer is by far not optimal but I hope it could at least help you a bit to understand the difficulty of that problem.
Comment: Thank you so much for the explanation, I understand the issue much better now. If I may ask a follow up question, if there is no way to know to which numbers keccak does and does not map, how does the ethereum network know which addresses to accept when for example fetching balance, does it accept every 40 character hex string and simply return 0 balance if there's no transactions associated to it, or does it have some further way of address verification that goes beyond checking the length and checksum?
Comment: @NicolasSchapeler You're right, it does not have additional checks. Every transaction that transfers value to a 40 character hexadecimal string or internally any sequence of exactly 20 bytes is accepted. The balance is checked in the following manner: Ethereum Accounts are stored inside the Ethereum State DB. The State DB contains a collection called "Worldstate". In that Worldstate an Ethereum address is mapped to an Account datastructure (Balance, Nonce, CodeHash, StorageRoot). If the mapping does not exist, the balance is 0. If the mapping does exist, the balance is Worldstate[adr][bal].
Comment: I'd assume thanks to your argumentation that it does not, but just want to be sure.
Comment: Here is a related post that could be helpful: https://ethereum.stackexchange.com/questions/3542/how-are-ethereum-addresses-generated


Inkscape problem: rectangle with unequal stroke width

Question: Can someone help with this problem in Inkscape?
When I attempt to draw an empty rectangle with stroke, what I get is a rectangle with stroke which lines are a little bit thicker on the left and right side compared to the top and bottom lines. In the process of drawing it the lines are still equal but once the rectangle is made they automatically change. I think it's something in the settings, but I just can't figure what it is. If I open a new Inkscape document, I don't have this problem anymore, but I just want to know what's the trick here. Does anyone know? cheers
Comment: Wow, interesting. It looks like you've scaled it after creating it, but I assume that's not the case?
Comment: Can you please post an SVG file with the rectangle?
Answer: If you only suspect the settings, then try
Edit > Preferences > Behavior > Transforms > uncheck scale stroke width.
If this does not fix the problem, you may have a problem with the document. I could recreate the problem/effect by applying a transformation to the current layer (using the xml editor). If such an transformation is the problem for you, there are two possible ways around it.

Create a new layer (layer > add new layer. Or ctrl+shift+n) and draw only on the new layer.

or

Open the xml editor (<>-icon in the toolbar. Or ctrl+shift+x). On the left, search for nodes like <svg:svg … or <svg:g …. Select such nodes and look for transform-attributes on the right-hand side. If there is a transform, select it and press DEL to delete it. Warning: This affects everything in the group.
Comment: This behavior is horrible. and I can't change it to be like the old one. If I wanted the thickness to change there should be a button or option, not be the default, it looks horrible :(
Comment: There's also a button in the toolbar to control scaling the stroke width. (As of v0.91, it's the first button after the width/height boxes.)
Comment: Del deletes the object and not the transformation. But this is super helpful thank you so much
Answer: I've had that happen before, but usually only when I'd already created an object with a particular stroke, then converted it to a path, and then resized it using the object-resize handles.
The fix for me was to just re-define the stroke width in the "Fill and Stroke" dialog.
Answer: I came across this problem too when I used the rectangle tool.
You need to change the "Store transformation" option in your preferences to Preserved:
Edit → Preferences → Behavior → Transforms → Store transformation
This solved it for me. I also prefer to not scale anything at all with transforms. So if you'd like that, you can disable that too in that preferences section.


Consume an arbitrary amount of system memory in Windows

Question: I'm looking for Windows program or method to consume an arbitrary amount of RAM. Purpose is to test how another program behaves when it's an a reduced memory situation.
Answer: one method is to create a virtual machine.
Using Oracle virtual box or vmware workstation.
You can specify amount of RAM and CPU allocation easily.
Obviously too low and you will hurt performance.
You could

Load your software inside the VM, and adjust it as needed.
Create an empty VM of any size just to suck up that much memory.  The VM has to be on to consume resources.  If if the VM has no OS it will still consume the requested amount of RAM.
Comment: Thanks. A little heavy-weight for what I was thinking but do-able and straightforward.
Answer: Are you asking from a programmer's point of view? I have nothing ready-made for that, but it looks trivial to create such "software" yourself.
For example, in C++ (no error-checking):
#include <iostream>

int main(int argc, char *argv[])
{
    int required_size = atoi(argv[1]);
    std::cout << "Hogging " << required_size << " bytes\n";
    char *memory_hog = new char[required_size];
    std::memset(memory_hog, 153, required_size);
    std::system("pause");
    return 0;
}

Run it from the command line like hog.exe 1073741824 (that's how many bytes there are in gigabyte). You can find the process in task manager to make sure it uses about that amount of memory. Press any key in the terminal window to exit.
Or, perhaps even simpler, in Python: [install from python.org], open the terminal, type python to launch it, then something like this (for Python 3):
a = [123] * (1024*1024*1024//8)

Again, you can find Python in task manager to make sure that's about 1 gigabyte, give or take. Use Ctrl-Z + Enter to exit Python, or del a and then a = [123] * <some other number> to consume some other number of bytes.
UPD.: this answer mentions some tools to limit memory usage by a process, that could be more practical.
Comment: I wasn't thinking of coding something, which is why I asked here instead of S.O, but the python method is so easy I'm accepting it.