Seeking Mobile GIS applications for Android Tablets?
Seeking Mobile Data collection software recommendations?
Suppose $A$ and $B$ are similar matrices. Show that $A$ and $B$ have the same eigenvalues with the same geometric multiplicities.      Similar matrices: Suppose $A$ and $B$ are $n\times n$ matrices over $\mathbb R$ or $\mathbb C$. We say $A$ and $B$ are similar, or that $A$ is similar to $B$, if there exists a matrix $P$ such that $B = P^{-1}AP$. When Bottom Navigation Isn't Best I'm developing a mobile app and dealing with various UI/UX issues. I'm open to all kinds of ideas at this stage, however some designers I consult with seem to be zealots for bottom-navigation and are hesitant in actually analyzing whether the bottom-nav is actually best for my app; they just want me to use the bottom tabs navigation as if it's some UI law.  One point I try to bring up is that my business model has users who aren't typical one-handed mobile users, are tech savvy, would use my app more of a tool, and would spend only a few minutes in it. The app isn't a typical lazy-content-browsing experience where you want to minimize fingers-over-top-of-screen interference, and where you want to keep the use transfixed and spending time in the app.  Anyways, I'd like to hear about situations where a bottom nav was decided-on, or started-with, and you had good reason to eliminate it and go with another navigation design.  Most articles out there talk about eliminating hamburger menus and diving into bottom nav. Is the converse simply going back to hamburger menu? What is the origin of Dol Goldur, and why did Sauron start there? Who built the fortress of Dol Goldur, and when was it built? And was it always a place for evil, or Sauron just occupied it?  Despite the fact that Mordor is much better fortified; artificially by the old fortifications,  and geographically, as it is surrounded by the mountains. Also considering the presence of mount doom that seem to enhance Sauron's power, Sauron chose to start his campaign from Dol Goldur, despite Mordor being ready for quite some time.  Why did he choose this enigmatic fortress, and not go straight for Mordor or even go earlier? Normalizing the final weights vector in the upper bound on the Perceptron's convergence The convergence of the "simple"  says that:  $$k\leqslant \left ( \frac{R\left \| \bar{\theta} \right \|}{\gamma } \right )^{2}$$  where $k$ is the number of iterations (in which the weights are updated), $R$ is the maximum distance of a sample from the origin, $\bar{\theta}$ is the final weights vector, and  $\gamma$ is the smallest distance from $\bar{\theta}$ to a sample (= the margin of hyperplane).  Many books implicitly say that  $\left \| \bar{\theta} \right \|$ is equal to 1. But why do they normalize it ? In C++, what is the purpose of the scope resolution operator when used without a scope? For instance:  ::foo(); How to join a LAN / IPX game on Diablo 1? Recently some of my friends and I grew nostalgic about the original Diablo and realized we've never truly tried the multiplayer aspect of that game. So we set up a modern VPN LAN solution via tuungle (using the appropriate IPX Wrappers) but the problem is, while any of us can manage to create session in Diablo FULL, others cannot find a way to join my IPX/LAN game.  There are no "join" buttons in the game itself.  I've read somewhere that Spawn version is a trial version but can be used to join Multiplayer games. If they can, is it possible for them to play the entire game on LAN or is trial restricted from choosing some classes/accessing some areas?  Or are there some other ways to join? How do I use one shape to delete a portion of another shape? I have created an arrow shape (rightmost in image), from which I wish to cut out the majority so that only two thin sides remain. The most accurate way to do this would be to duplicate the shape and to somehow use the duplicate (leftmost in image) to remove the chunk that I no longer desire from the original. I am not sure what to do after the duplication, however, or if this method is even possible? Is there a better one? Access to journals for individuals outside of an institution? For all that is said about the wealth of information that is freely available on the internet, the fact is that most of it is incomplete, dumbed down, lacking in context or downright wrong.   Individuals spend the best part of 20 years completely oblivious to the existence of journals and the process of peer review and even then we'd be lucky if 10% of those with access to journals (usually through an institution) actually bother to invest in them.   Granted that some journals will be totally inaccessible to those without a solid background in some particular field but by and large exposure is a good thing and there are many areas of research where individuals will benefit directly from having read these.  Where does this come from?  I decided I wanted to read Popular Politics in the Late Medieval City: York and Bruge in The English Historical Review today, mainly because it looks interesting and I'm hoping to invest more time into learning about British and European History. Incidentally I also wouldn't mind tucking into Super Stable Clocks, Nature 500, 505 (29 August 2013) and a number of data analysis and big data journals in order to advance my career.   Now, not being affiliated with an institution that subscribes to these journals means that I would typically have to pay between £5 ($10) and £15 ($25) per article that I read... I could probably spend £100 just to pass an hour by.  Question   What's being done to address the lockdown on 'higher' education material? I've noticed that the Directory of Open Access Journals publishes open articles and other firms are doing similar, mainly with journals in new fields? How could I, as an individual outside of an institution, gain journal access without it costing so much money? Booking a flight without passport info I have been looking to book a bundle (hotel and flight) with Expedia to Puerto Vallarta MX. When I get to the booking section it does not ask for my passport number. Do they ask for my passport after I book? Or later when the date gets near? My passport is currently being renewed and I want to book my hotel and flight before they sell out but I am afraid it'll ask me for my passport number. Can anyone inform me about this situation? set 4-bit nibble in an int type Understanding hard drive space How to limit execution time of a function call? There is a socket related function call in my code, that function is from another module thus out of my control, the problem is that it blocks for hours occasionally, which is totally unacceptable, How can I limit the function execution time from my code? I guess the solution must utilize another thread. Is there any way to backtrack to previous areas? How to best encapsulate monetary values in a database If you have an $m \times n$ matrix and the rows are linearly independent, are the columns linearly independent too?  I know that it's the case for $n \times n$ matrices. I've yet tried to think about it, and I think the answer is yes, for example the matrix: $\begin{bmatrix} 1 &amp; 2 &amp; 3 \\ a &amp; 2a &amp; 3c \end{bmatrix}$ has linearly dependent rows and columns, but I'm not sure that it works for every $m \times n$ matrix. Can't create new folder from anywhere in Windows 7 I have this problem on two of my new laptops and can't seem to find a decent workable solution elsewhere in forum land. The problem is that on my Windows 7 Professional machines the right mouse button doesn't show the New Folder option and elsewhere as well (via Explorer) I'm unable to create new folders.   I'll be happy to get this tiny problem resolved and declare that Windows 7 is almost perfect! Thanks to all of you in advance for your contribution!  PS: None of the Vista solutions seem to work here!      Tried NewFolderFix.reg, didn't work - "Not all data was succesfully written to the registry. Some keys are open by the system or other processes."  Converted FolderFix.reg to .inf file and that worked.  Don't recall the problem appearing after an update.  MS answer to the explore process hanging (KB 972685) was to install the latest Visual C++ Update (vcredist.exe).  Nope. That didn't help either.  I haven't touched Silverlight since installation when Windows 7 hit the shelves. I tortured the RC installation before that, and never had problems there either.    UPDATE-  Logged back into Administrator account, still missing from there. Spent a bit more time looking instead of just fixing. Just yto make sure, logged back into my user account - still OK there.  Turns out the entries in HKCR\CLSID were the culprit here. Reg file wouldn't take again (as above) but inf file fixed it. This key was unable to be entered from regfile, or altered or deleted in Regedit (Permissions).   Don't quite understand why a common key in HKCR needed to be entered separately for each user.   Here is the file I used to fix it. Just copy into notepad, save as newfolderfix.inf, rt-click and select Install  ================================================================  [Version]  Signature=$Windows NT$  [DefaultInstall]  AddReg     =REGEntries.AddReg  [REGEntries.AddReg]  HKCR,"%String0%",,0x0,"CLSID_ExecuteFolder"  HKCR,"%String0%\InProcServer32",,0x0,"ExplorerFrame.dll"  HKCR,"%String0%\InProcServer32","ThreadingModel",0x0,"Apartment"   [Strings]  String0 = "CLSID\{11dbb47c-a525-400b-9e80-a54615a090c0}"  =============================================================   Thanks to others who helped point me in the right direction. Noetherian property for exact sequence Let $0 \to M' \xrightarrow{\alpha} M \xrightarrow{\beta} M'' \to 0$ be an exact sequence of $A$-modules. Then $M$ is Noetherian is equivalent to $M'$ and $M''$ are Noetherian.  For the ''$\Leftarrow$'' case:  I guess if we let $(L_n)_{n\geq 1}$ be an ascending chain of submodules of $M$, then $(\alpha ^{-1}(L_n))_{n\geq 1}$ is a chain in $M'$, and $(\beta(L_n))_{n\geq 1}$ is a chain in  $M''$. For large $n$ both these chains are stationary. Then why we know the chain $(L_n)$ is stationary?   Thanks! Headline Language Is there a particular term for the abbreviated language used in headlines (the removal of at least articles and conjunctions)? Why are drivers and firmwares almost always written in C or ASM and not C++? Python ( or general programming ). Why use  instead of != and are there risks?