How Matcher.find() works
SCJP6 regex issue
I read this great answer about how ReLu could approximate non-linear functions. However, if ReLu can approximate such functions, why cant linear activation function do the same? If they can, why linear activation functions are strictly prohibited in NN? What is the precise definition of a rigid shape? Why does magnet attract iron but not other metals? While searching, i found this page:  but it does not have full explanation. So Please tell full explanation of why this happens? How is an instance initializer different from a constructor? alternative to "netstat -s" prints out a lot of very detailed protocol statistics like number of TCP reset messages received or number of ICMP "echo request" messages sent or number of packets dropped because of a missing route.  When in Linux netstat is considered deprecated at nowadays, then is there an alternative?  Statistics provided by ss -s are superficial compared to the ones provided by netstat. Uninstalling QGIS that was installed using OSGeo I installed QGIS using OSGEO4W, and would love to know how to uninstall it, because when I go to "Control Panel > Programs > Uninstall" the program does not appear in the list of installed programs.   How can I do this? Word for "scary thing that's about to occur"? I have the feeling I'm forgetting a very simple word. But anyway, is there a word for that? Example:     The [...] that haven't occurred yet are the most scary ones. Cleaning Contaminated Disc Rotors I've had an eternal struggle with my current bike over brake contamination. The levers and calipers are shimano ultegra r8000, so the latest and (almost) greatest.  I first noticed it when I took it to a repair shop (i no longer use) for a bleed, it came back and the front brake would squeal like crazy and at low speeds had little to no braking force. You can stop from speed but then struggle to come to a halt without using your foot.  At around 2000 miles I tried to replace the brake pads, when I took them out they were black with grime on both sets (front &amp; back), not to mention worn down to the metal. I replaced them with the L04C sintered pads, gave the callipers a good cleaning with a towel (no chemicals) and fitted the new set.  Annoyingly all of my braking issues are back, now I probably should have cleaned the rotors, I simply used some muc off disc brake cleaner on them. I would like to know the best way to clean the rotors, I've inspected the pads and they are looking fairly black now, with plenty of tread left. I'm going to abandon these pads and fit a new set. For the rotors I plan to completely remove them from the wheels (they are center lock fitted) and try and treat them off the bike, what is the best way to fully clean them? They have plenty of wear left in them but you can see these black grooves in them, and plenty of muck on the back that I struggle to get off.  Below are images of the rotors after soaking them in disc brake cleaners, waiting and then wiping them down with a clean, microfiber towel.   Front Wheel Outside Rotor   Front Wheel Inside Rotor - note the increased dirt on this side  Looking at ways people clean their disc rotors, I've seen plenty of suggestions that I would need to burn the contaminants off the discs. Would the best approach be to remove them and use a blowtorch, should I soak them in some nasty chemicals overnight before I try to heat them? Do I try baking them in the oven?  And finally, what is the best way to prevent the brakes from becoming contaminated in the future? it's really off putting when they squeal and don't perform how I'd expect because it means I'm more reserved whilst out riding on the bike, leading to reduced time riding around outside. I commute on this bike (50 miles a week) and then ride about 50 on the weekends also, so it see's it's fair share of road use. I tend to wash it once after my big ride on saturdays and will rinse it off if it's been raining, any day that occurs (since I live in north east england, the acid rain..). I've owned disc brake bikes before and never had half the issues I've had with this, I had a cheap trek with tektro brakes and the brakes were sharper and never had any issues with contamination whatsoever (i did around 500 miles on that bike before a motorist happened).  Thanks for any and all advice :) Is it safe to have laptop turned on 24/7? I have an old HP dv7-7210sp laptop and I want to use it as a server. Is it safe to have it turned on 24/7? The server will be used with Nextcloud to backup my data.  Should I remove the battery from the laptop or keep it as a backup power source?  Also, is it safe to run HDD 24/7 or should I enable APM so it spins down after some time of inactivity?  Can the laptop burn if I leave it running? One server with multiple desktops "heads" with VNC I am managing a system of kiosks.  Each kiosk currently is running a web browser with the application for the kiosk running in the browser.  Each kiosk needs to be able to display separate content.  At times, the application running in the web browser freezes.  Thus, I have to go out to the site to refresh the page.  I want to see if there is a way to have one central server that has multiple browser heads.  Then each kiosk would run a program like VNC to display one of the heads.  This way when the program freezes, I just have to login to the central server and refresh the page.  Getting VNC or another remote desktop software installed on the clients is no problem.  What I am looking for is a way to have VNC remote into a specific head of a head of a web browser.  Does such a thing exist?  Or do I have to run a VM for each kiosk to remote into?  Any advice, pointers, or solutions would be helpful. If matrix $A$ is unitary and $B^2=A$, is $B$ necessarily unitary? In Episode III,  explains to Anakin the power of the Dark Side to save people from death. He mentions  - the Sith who discovered this. Sidious then claims he died, which seems odd, given that kind of power.   Then in Episode VII (The Force Awakens) we find a Sith Lord who has appeared from no where. There seems to be two loose ends that fit nicely together.   My question is: Is there evidence to suggest that Supreme Leader Snoke is Darth Plagueis? How do I keep both the background and foreground in the image in focus at the same time? How do you have both the background and foreground in the image in focus at the same time?  Last week I was attempting a shot where I had the back of a hat in focus and in the distance you could see a mountain. I wanted both in focus, but could either focus on the mountain or the hat. I ended up taking the in-focus shots of both and merging them in Photoshop. While that isn't difficult I would prefer to shoot the shot as accurate as possible. From what I have read aperture is important in the depth of field but what are the techniques for keeping both the background and foreground in focus?  I am using a Nikon D5100 with a 18-55mm f/3.5-5.6 (standard kit lens) and a 55-200mm  f/4.5-5.6.    almost answers my question, but I am a bit confused. Can someone explain this a bit differently? Thanks! I have over 400 open-ended responses. The total has been coded by one rater, and a 10% identical sample of the total has been coded by 2 raters. There is a choice of 14 nominal codes, of which the rater can use any number per case, though most cases have between 1-4 codes. Which statistical test is the most appropriate to determine if I have inter-rater agreement on the 10% sample?   Also am I right in assuming that I will need to treat each code as a variable and look for the level of agreement for each variable?   I'm using SPSS 21.  Much thanks, Kellie Backslash escaping in code regions in comments I've noticed that in comments, when you create `code region` with backticks, the backslash will still work as an escape character within that region (but it should not, IMHO).  To clarify:   In comments, `\\` will be rendered as \, but it should be rendered as \\ In the post body itself, `\\` will be rendered as \\ (i.e., correctly)   This is especially confusing when you enter regular expressions into a comment, since backslash-escaping is very common there, and confusion increases if you are dealing with a regex that is double-escaped for representation in a string.   At some point you lose track how many backslashes you must make so the comment renders correctly, or you don't notice fast enough (or at all) and the comment contains wrong code where the same markup in a question or answer would come out as perfectly correct.   It's just that comments can't be corrected anymore after the grace period, leaving you with the choice of either deleting the comment, thus crippling the conversation, or engaging in a trial-and-error game of writing another comment with even more backslashes to explain the issue.  My question is two-fold:   Will this error be corrected? If yes, existing comments should probably be searched and "fixed" by a routine that tries to do the right thing (this is probably somewhere between hard and impossible) Or, can I rest assured that never ever the behavior of the backslash in comments is going to be changed, so I can start working around this issue by hand, knowing that they won't start displaying incorrectly at some point in the future? C++ cout hex values? I want to do:  int a = 255;  cout &lt;&lt; a;   and have it show FF in the output, how would I do this? Prove $\lim_{n\to\infty} \frac{a_n}{n}$ exists for positive sequence where $a_{n+m} \leq a_n + a_m$ Let $\{a_n\}_{n=1}^\infty$ be a positive sequence of real numbers such that $a_{n+m} \leq a_n + a_m.$  Prove that $\lim_{n\to\infty} \frac{a_n}{n}$ exists by showing that $\lim_{n\to\infty} \frac{a_n}{n} = \inf_{n \geq 1} \frac{a_n}{n}.$   A similar question has been posted previously, see  , and I have found that this is the general result of "Fekete's Subadditive Lemma" for sequences, but I am unhappy with the few proofs I've seen.  Perhaps the clearest one I have found is  , but this seems a bit tricky for what is expected on this qualifier question.  We are given a hint "treat $\liminf$ and $\limsup$ separately".  Does anyone know of a more direct way to show that this limit exists? A guide to moderating chat Is there a "win64" identifier in Qmake project files?  documentation does not mention other than unix / macx / win32.  So far I've tried using:  win32:message("using win32") win64:message("using win64") amd64:message("using amd64")   The result is always "using win32".  Must I use a separate project-file for x32 and x64 projects, so they would compile against correct libraries? Is there any other way to identify between 32-bit and 64-bit environments? The shellscript is very simple:  retroarch $* -c /tmp/retroarch/Data/retroarch/gambatte.cfg   ("retroarch" is another shellscript)  If the filename passed contains spaces it fails:  RetroArch [ERROR] :: Could not read ROM file.