I am really confused when efficient and effective appear  in a sentence.   I get quite confused about the whole meaning of the sense it pulls of.
I feel that there is a subtle difference in meaning between 'efficacy' and 'efficiency', but I couldn't find any authoritative sources that could help me confirm or refute this. Is there any difference between the two words, especially in scientific context?
Any way to tell apart a CPU defect from a mainboard defect? I have a fairly modern desktop computer, an AMD Athlon II X2 based silent PC, that does not work.  When turned on, it will start physically (all fans are rotating, disks start up...) but not give a signal on any of the graphics ports (DVI, VGA, and HDMI, I tried all three). Also, the reset button does not seem to have any effect.  I have stripped the mainboard bare of all SATA connections, extension cards, and the one 2GB RAM chip to eliminate them as the problem source, but to no avail, so I think it's fair to assume it's either the mainboard or the processor that are at fault.  However, I have neither a replacement mainboard, nor a replacement processor handy to identify which one is broken. The cause of the defect is unknown, so for all I know, it could be both. Therefore, I'm reluctant to buy replacement hardware blindly before knowing more.   Is there any way to further diagnose (or at least get some indication) which component is broken without buying replacement hardware? Creating node shapes All Stack Exchange data dumps The original ClearBits link to the September 2011 data dump has broken. How can I access it and other previous data dumps? The Internet Archive only has . Maximum power transfer and Thevenin Unreasonable RAM usage in Windows 7 I have a fresh install of Windows 7, and my RAM in normal startup goes up to 2.5GB. I looked at Task Manager, and there's at least 1.5GB missing from there and in Resource Monitor as well. There's no indication of what's using that RAM. Can someone tell me how I can find out what's consuming my memory? I believe it's a virus, but none of the free antivirus programs tracked it down.   I added the pictures below. If this is normal usage of Windows 7 as some answers imply, then I don't get this at all.   P.S. My Windows 8 Installation was running below 2.5GB, actually it was 1. something, until recently that I transferred some files from another computer which had the same problem that mine has now. I deleted Windows 8 and installed Windows 7, since I would do that anyway, and now I'm getting high memory usage in Windows 7 as well.   (Click images to enlarge) Currently, when someone suggests an edit, they are unable to keep track of it without watching reputation levels or constantly refreshing the page. What I would like is a notification, that shows up like the notification where someone has edited your question, that shows whether a suggested edit has been approved or rejected after the last vote is cast. This way, the community can be notified when their edit has been rejected/approved, while focusing their efforts on another question/answer. What Nikon lens to buy to make photos of birds? How assign shortcut to custom function? How does the human eye knows how far the object from which the photon was reflected? A photon is emitted from a source and reflected off an object (or objects) until it hits the human eye. The color of the object we see depends on the photon wavelength. If photon travels with constant speed how does the human eye know how far the object from which the photon was reflected? How to make child collide I'm taking an intro course in Probability theory, and we have just defined expectation for a random variable as $E(X) = E(X^+) - E(X^-)$ if either of them is finite (extending the definition first from simple positive rv to positive rv, and then to all rvs, positive or not).  Then I came across this result for the expectation of a positive random variable. Let $(\Omega, \mathcal{F}, P)$ be a probability space and $X \ge 0$ be a positive rv:  $$ E(X) = \int_{\Omega} X dP = \int_\Omega \int_0^\infty \mathbf{1}_{\{X &gt; t\}} dt  \, d P = \int_{0}^\infty P(X &gt; t) dt. $$ Actually, I'm familiar with this result, and the proof I've seen before involves converting $\int^\infty_0 P(X &gt; t) \, dt$ to a double integral. What I'm struggling with is the step $ \int_{\Omega} X dP = \int_\Omega \int_0^\infty \mathbf{1}_{\{X &gt; t\}} dt  \, d P $, and also the formal definition of an expectation itself.   I have no previous with integration or a "hard analysis" background, and the material covered so far in the course I'm taking has only used $\int_\Omega X dP$ as a notational device for $E(X)$. In general, any pointers to literature or "intuitive" explanations are more than welcome.  Thanks in advance! Round a double to 2 decimal places Capturing a time in milliseconds According to the definition on , a multiple  is a root with  $n\geq 2$. For example, in the equation $(x-1)^2 = 0$, $1$ it the multiple (double) root.  Question: Why is $x = 1$ the multiple root of $(x-1)^2 = 0$?  What does multiplicity mean in this case? According to Wolfram multiplicity is the number of values for which a condition holds, or the number of times for which a polynomial equation has a root at a given point. In what way does the polynomial $x^2 - 2x + 1 = 0$ have multiple roots? What are the difference between:    the action $\int_{t_{1}}^{t_{2}}(L+H) dt$ that we use in the principle of least action, and  the action integral $\int_{t_{1}}^{t_{2}}L dt$ that we use in Hamilton's variational principle?   References:   H. Goldstein, Classical Mechanics, Section 8.6. H. Goldstein, Classical Mechanics, Chapter 2. What is the best regular expression to check if a string is a valid URL? How to delay or slowly loop commands? I found 11 questions like this on gamingSE already, but none of them have proper and up-to-date answers. So I'm creating this Q&amp;A:  How do you either activate a command x seconds/minutes/hours/… in the future or every x seconds/minutes/… in a loop?  Repeating command blocks and ticking functions execute 20 times per second, redstone is  in many situations and most of the extremely fancy solutions, like falling blocks in cobwebs, have broken over time or are needlessly complicated. Yes, I'm a moron, and I tried to manually install a higher point release of python 2.7.16 to /usr/bin/  (i did ./configure --prefix=/usr) on my Ubuntu 16.04 machine. It seems to work fine EXCEPT for packages that depended on python, like apt-listchanges, which fails with messages like ImportError: No module named apt_pkg  there's no make uninstall available, I've tried manually removing files, and still when I try apt --reinstall install python, Nothing gets overwritten and the python executable still gives the new 2.7.16 version...   Any idea how to get the official repository version back?? How do high traffic sites service more than 65535 TCP connections? How do I fix the left mouse opening the menu instead of breaking blocks?