I am looking for a term which denotes that 'X person is an expert in framing search-engine queries' . Some synonyms such as slackers and hackers come to mind but they are pretty generic terms. Is there a specific term or should I just use 'slackers' or/and 'hackers' and be done with it.
Exact Duplicate:        I was reading an article on MSDN where I found a mention to google-fu. It says, “To search for C++ delimeters and code snippets is going to take a little Google-fu on the reader's part.” what does google-fu mean?
Where to place my local website starting with the 2.4.7 version of apache2? How to find all the available tools in mac terminal? I am trying to setup a bunch of development projects in my Mac. I have to run various tools like python, ruby, scala, groovy etc.  To see if a tool is available I use options like   ruby --version.    Instead I would like to see all the list of tools available in Mac terminal via a single command. What is the command/options for it? Is there something like "Firebug for IE" (for debugging JavaScript)? I'm trying to fix some JavaScript bugs. Firebug makes debugging these issues a lot easier when working in Firefox, but what do you do when the code works fine on Firefox but IE is complaining? Connection between rank and matrix product I have a problem understanding the following:     Let $A$ be an $m \times n$ matrix and let t $\in \mathbb{N}$. Prove that   $\operatorname{rank}(A)\leq t$ if and only if there exists an $m \times t$ matrix $B$ and a $t \times n$ matrix $C$ so that $A = BC$.   I know what a rank is but I can't make a connection between the rank and the existence of two matrices such that $A = BC$. A friend of mine has some very old photos where the deterioration process seems to have increased in the past few years, and the owner is worried about the preservation of these old memories.  They have been stored inside an album within plastic sleeves. The owner is not aware of the display method prior to that.   I have been informed by the owner that since being in their possession, they seem to be looking worse than when first viewed and seem to be falling apart.   He is looking for the best way to preserve these photos inside an album, but not really sure what would be the best method. I have suggested for the albums as a whole to be stored in vacuum sealed bags for now, but I'm not even sure if that is good!  I am looking for any suggestions or personal experiences from anyone who has had to deal with such photos and what they did to preserve their memories. What is the difference between DPI (dots per inch) and PPI (pixels per inch)? There are lots of other questions on Graphic Design which partly cover this, e.g. .  However, I have become frustrated at the number of questions and answers which confuse the two terms. I think understanding the difference is important.  So here's a place to answer this question well and clear up the confusion! Homotopy invariance for cohomology I have tried to read Hatcher's  book. He proved  Theorem 2.10: If two maps $f,g :X \to Y$ are homotopic, then they induce the same homomorphism $f_* = g_*:H_n(X) \to H_n(Y)$.  One can immediately obtain following corollaries using the dual version of prism operator described in Theorem 2.10 and some facts:  Corollary 1: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H_n(X) \to \tilde H_n(Y)$ for $n&gt;0$.  Corollary 2: If $f,g :(X,A) \to (Y,B)$ are homotopic, then $f_* = g_*:H_n(X,A) \to H_n(Y,B)$.  Corollary 3: If $f,g :X \to Y$ are homotopic, then $f^* = g^*: H^n(X) \to H^n(Y)$.  Corollary 4: If $f,g :X \to Y$ are homotopic, then $f^* = g^*:\tilde H^n(X) \to \tilde H^n(Y)$ for $n&gt;0$.  Corollary 5: If $f,g :(X,A) \to (Y,B)$ are homotopic, then $f^* = g^*:H^n(X,A) \to H^n(Y,B)$.  I wonder that how can we prove the following statements:  Corollary 6: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H_0(X) \to \tilde H_0(Y)$.  Corollary 7: If $f,g :X \to Y$ are homotopic, then $f_* = g_*:\tilde H^0(X) \to \tilde H^0(Y)$.  An attempt for Corollary 7 is  Proof of Corollary 7: By Universal Coefficient Theorem, we have $$\tilde H^0(X;G) \approx Hom(\tilde H_0(X),G).$$  Hence the result follows from the dualization of the proof Corollary 6.  Any help will be appreciated. "I have" vs "I have got" I don't know what is the difference between using "I have got" and "I have" For example:      He's got broad shoulders.    Is it possible to say:      He has broad shoulders.    If yes, so what is the difference? How to compare two Pearson correlation coefficients Since a few days I do not get ahead when trying to compare two Pearson correlation coefficients. Imagine that I've got two datasets where on each I do a correlation between Land Surface Temperature and an urban metric. The datasets are different in their length, so the first one has round about 160.000 observables and the second one has about 2400 observables. For the correlation on the first dataset I get a Pearson of -0.74 and for the second I get -0.885. Now I want to find out whether these coefficients are significantly different from each other. Is there any appropriate method you could suggest?  I already played around with the Fisher-Z-Transformation, but from my point of view with no purposeful results. When I calculate the Fisher-Z on my coefficients, it results in 20.95 (Fisher-Z).  I would be very happy about suitable advices. Tools to measure the nonrandomness of database I was working on historical data looking for anomalous patterns that we would not expect to occur at random. I'd like to create a scheme to analyze data and markets to test for statistical significance and consistency over time.  Question : Are there some tools we could use to evaluate the nonrandomness of a database? What do we use usually to say that something is random or not (statistically)? Figure we work with change in some value over time. What processing is done on RAW files in the camera? Recently I came across a debate about whether it's fair to call RAW 'unprocessed' or 'unaltered' sensor data of a DSLR. As far as I know, the analog sensor data is processed into a digital RAW file using the ISO setting, a process during which the Bayer-sensor data is demosaiced as well. However, those are just the necessary steps for saving a digital file while maintaining maximum quality.  Are those assumptions correct? If so, are there any additional steps that need to be performed between the sensor receiving light and the saving of the RAW file? And can those be reasonably be described as an 'alteration' of the sensor data, or is it fair to say that a RAW file holds the unaltered sensor data? Why is $\mathbb{R}^2$ not a subspace of $\mathbb{R}^3$? I cannot understand why $\mathbb{R}^2$ is not a subspace of $\mathbb{R}^3$.   My reasoning is as follows: Choose any elements $v_1$ and $v_2$ from $\mathbb{R}^2$, add them together you get an element of $\mathbb{R}^2$ and same for scalar multiplication and $0$ vector is an element of $\mathbb{R}^2$. So where did I go wrong? I am using ArcGIS Desktop 10.1.   I am trying to find the location of the highest value pixel in my Direct Solar Radiation Raster. I can see the extent of the data in my raster but don't know where the highest value pertains to.   Is there a way to simply select pixel with highest value or create a point at highest value? How do I delete one of two Ubuntus on my PC Available US State or National business (or employer) database lists? This question dovetails with this post on .  I am familiar with some of larger, paid-for business registry's like  and .  While the detailed information their business listings database include (like # of employees, annual sales, industry code, etc) is fantastic, if you are on a limited budget, sometimes the cost of purchasing the data outweighs the value you can get from it.  If you have geocoding capabilities in house, one could potentially create a reasonable surrogate by spatially-enabling (geocoding) a publicly available business listing on your own.    If you were looking to take on this type of project, where would you start your research? Do you know of US agencies at a State or National level that maintain this type of information, AND are publicly available for download or minimal purchase? Is there any way to recover deleted files which may have since been overwritten? I deleted lots of files &amp; folders on my laptop and then I put a new files in the same folders. I need to recover the deleted files. I tried a lot of recovery software and I couldn't recover my old files.   I read that if you refill the folders with new files after deleting old ones then I can't recover them again. Is that true?   What should I do? Ubuntu system is broken after accidentally uninstalling many packages How do I detect the direction of 2D rectangular object collisions? I have played the game Othello (Reversi) numerous times but I never approach it with a specific logic or algorithm to apply on each move in my mind. I won many times and lost as much. How would one approach this game? How would one work in his mind to prune the possible moves and choose the &quot;right&quot; one in each step? I see that most Othello CPUs more or less &quot;think&quot; the same at each move, how should I think on each move? I'm using Fedora and wonder if there is some way I can exclude kernel updates when I run yum update, until I specifically want to update the kernel.    The reason why I am concerned about this is because sometimes it requires a lot of extra research finding patches for some programs and extra time spent recompiling them to work on the new kernel.  I am thinking VMWare specifically as one example.   I wonder if there is some way for yum update to NOT update the kernel and only notify me that a new one is available when it goes through its routine so that I can decide to put it off until a more convenient time.  Or is this thinking likely to cause other issues?