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  • PC shuts down when installing ubuntu?

    - by Robin002
    I'm now using ubuntu from USB, and I'd like to install ubuntu on my hard disk. I tried the option of removing Vista while installing ubuntu. However, near the end of the installation process (presumably the end because I can see some slideshows on how to start using ubuntu), the screen suddenly goes to black with white words running around on it. Soon the computer shuts down. After that, restarting leads to a black screen with only a small white cursor on the top left corner. The cursor keeps blinking and nothing happens. I found that I can alternatively choose to boot with USB by hitting F12 just when the computer starts. So I tried to reinstall ubuntu by running ubuntu on USB. One of the options of installation is to update ubuntu 11.04 to ubuntu 11.04, so it seems the ubuntu is already installed somehow. Anyways, I tried both update and delete and install option but the same thing happens as the 1st time (sometimes before reaching the end), while I still cannot start my PC as ubuntu (without USB). How may I install ubuntu properly?

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  • Ranking players depending on decision making during a game

    - by tabchas
    How would I go about a ranking system for players that play a game? Basically, looking at video games, players throughout the game make critical decisions that ultimately impact the end game result. Is there a way or how would I go about a way to translate some of those factors (leveling up certain skills, purchasing certain items, etc.) into something like a curve that can be plotted on a graph? This game that I would like to implement this is League of Legends. Example: Player is Level 1 in the beginning. Gets a kill very early in the game (he gets gold because of the kill and it increases his "power curve"), and purchases attack damage (gives him more damage which also increases his "power curve". However, the player that he killed (Player 2), buys armor (counters attack damage). This slightly increases Player 2's own power curve, and reduces Player 1's power curve. There's many factors I would like to take into account. These relative factors (example: BECAUSE Player 2 built armor, and I am mainly attack damage, it lowers my OWN power curve) seem the hardest to implement. My question is this: Is there a certain way to approach this task? Are there similar theoretical concepts behind ranking systems that I should read up on? I've seen the ELO system, but it doesn't seem what I want since it simply takes into account wins and losses.

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  • How can one find software development work that involves directly the final end user?

    - by RJa
    I've worked in software development for 15 years and, while there have been signficant personal achievements and a lot of experience, I've always felt detached from the man/woman-on-the-street, the every day person, how it affects their lives, in a number of ways: the technologies: embedded software, hidden away, stuff not seen by the everyday person. Or process technology supporting manufactured products the size of the systems, meaning many jobs, divided up, work is abstract, not one person can see the whole picture the organisations: large, with departments dealing with different areas, the software, the hardware, the marketing, the sales, the customer support the locations and hours: out-of-town business parks away from the rest of society, fixed locations, inflexible: 9-5 everyday This to me seems typical of the companies I worked for and see elsewhere. Granted, there are positives such as the technology itself and usually being among high calibre co-workers, but the above points frustrate me about the industry because they detach the work from its meaning. How can one: change these things in an existing job, or compensate for them? find other work that avoids these and connects with the final end user? Job designs tend to focus on the job content and technical requirements rather than how the job aims to fulfil end user needs, is meaningful.

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  • JAVA - Strange problem (probably thread problem) with JTable & Model

    - by Stefanos Kargas
    I am using 2 Tables (JTable) with their DefaultTableModels. The first table is already populated. The second table is populated for each row of the first table (using an SQL Query). My purpose is to export every line of the first table with it's respective lines of the second in an Excel File. I am doing it with a for (for each line of 1st table), in which I write a line of the 1st table in the Excel File, then I populate the 2nd table (for this line of 1st Table), I get every line from the Table (from it's Model actually) and put it in the Excel File under the current line of 1st table. This means that if I have n lines in first table I will clear and populate again the second table n times. All this code is called in a seperate thread. THE PROBLEM IS: Everything works perfectly fine ecxept that I am getting some exceptions. The strange thing is that I'm not getting anything false in my result. The Excel file is perfect. Some of the lines of the exceptions are: Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0 = 0 at java.util.Vector.elementAt(Vector.java:427) at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:632) at javax.swing.JComponent.paint(JComponent.java:1017) at javax.swing.RepaintManager.paint(RepaintManager.java:1220) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:803) I am assuming that the problem lies in the fact that the second table needs some more time to be populated before I try to get any data from it. That's why I see RepaintManager and paintDirtyRegions in my exceptions. Another thing I did is that I ran my program in debug mode and I put a breakpoint after each population of the 2nd table. Then I pressed F5 to continue for each population of 2nd table and no exception appeared. The program came to it's end without any exceptions. This is another important fact that tells me that maybe in this case I gave the table enough time to be populated. Of course you will ask me: If your program works fine, why do you care about the exceptions? I care for avoiding any future problems and I care to have a better understanding of Java and Java GUI and threads. Why do you depend on a GUI component (and it's model) to get your information and why don't you recreate the resultset that populates your tables using an SQL Query and get your info from the resultset? That would be the best and the right way. The fact is that I have the tables code ready and it was easier for me to just get the info from them. But the right way would be to get everything direct from database. Anyway what I did brought out my question, and answering it would help me understand more things about java. So I posted it.

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  • div width problem...problem is cross browser

    - by Aakash Sahai
    hello ol. I have a div having two buttons inside it as |Add| and |Cancel|. I didnt set any width to that div intially and as a result they were displayed vertically not in horizontal.then i add width in % to 11.5%.now the display is ok in moz but not in chrome and ie.i cant use pixels neither in height nor width.problem explanied by example |_______| // a textbox |Add| //initially with no width |Cancel| //after width to 11.5% in moz |_______| |Add| |Cancel| //after width to 11.5% in chrome and ie |_______| |Add| |Cancel| so u can see that in moz it is aligned to the above textbox but not in ie and chrome.hope sum ie hack or chrome hack may lead to correct result..or ONLY a MOZ hack..

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  • Is problem solving of puzzles/logic tests a skill that can be developed with practise or only someth

    - by dotnetdev
    Programming is essentially problem solving/using a lot of logic. With solving puzzles (like the ones recruiters like MS etc ask), is this a skill that can be developed with practise or is it a skill that only someone who is gifted has (I assume the former as many people can pass these tests)? Even so, I keep thinking it is a special skill for someone gifted, not for someone with a lot of practise. I guess that with practise you are perhaps more open-minded and start to think out of the box more (solving technical problems in development may also foster this mindset perhaps). Thanks

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  • struts datagrid problem - can't solve this problem

    - by shien-angel
    i am creating datagrid using the struts-layout. and i encountered this problem javax.servlet.ServletException: DispatchMapping[/monitor/datagridBL]???????????????????? at org.apache.struts.actions.DispatchAction.getParameter(DispatchAction.java:325) at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:170) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) at jp.terasoluna.fw.web.struts.action.RequestProcessorEx.process(RequestProcessorEx.java:149) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227) at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125) at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292) at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26) at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56) at jp.co.anicom.fw.web.common.controller.RequestEncodeFilter.doFilter(RequestEncodeFilter.java:42) at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56) at jp.co.anicom.fw.web.common.controller.SessionExpirationFilter.doFilter(SessionExpirationFilter.java:89) at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56) at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3588) at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321) at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121) at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2200) at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2106) at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1428) at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201) at weblogic.work.ExecuteThread.run(ExecuteThread.java:173) i have been looking for ways on how to solve this. would somebody help me please...

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  • How can I direct edge to get out of the diamond on the right?

    - by Didier Trosset
    I have a simple dot diagram to show how to perform tests. PerformTests; PerformTests<---+ PerformTests -> TestsPassed; | | TestsPassed [shape="diamond"]; v | TestsPassed -> Release [label="Yes"]; TestsPassed | TestsPassed -> FixErrors [label="No"]; Y| N\ | FixErrors -> PerformTests; v FixErrors Release The diagram shows square boxes for all nodes, except TestPassed that has a diamond shape. My issue is here. I'd like the edge that goes outside of the diamond for No to be getting out of the diamond at the right (east) instead of oblique down-right (south-east). What I have What I want ^ ^ / \ / \ < > < >---> \ /\ \ / v \ v I've seen such compass_pt in the dot grammar, but cannot figure out how to use it. I what I want possible, and how to do it?

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  • GridView edit problem If primary key is editable (design problem)

    - by Nassign
    I would like to ask about the design of table based on it's editability in a Grid View. Let me explain. For example, I have a table named ProductCustomerRel. Method 1 CustomerCode varchar PK ProductCode varchar PK StoreCode varchar PK Quantity int Note text So the combination of the CustomerCode, StoreCode and ProductCode must be unique. The record is displayed on a gridview. The requirement is that you can edit the customer, product and storecode but when the data is saved, the PK constraint must still persist. The problem here is it would be natural for a grid to be able to edit the 3 primary key, you can only achieve the update operation of the grid view by first deleting the row and then inserting the row with the updated data. An alternative to this is to just update the table and add a SeqNo, and just enforce the unique constraint of the 3 columns when inserting and updating in the grid view. Method 2 SeqNo int PK CustomerCode varchar ProductCode varchar StoreCode varchar Quantity int Note text My question is which of the two method is better? or is there another way to do this?

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  • Blocking problem, C#, .net, Deserializing XML to object problem

    - by fernando
    Hi I have a blocking problem I have XML file under some url http://myserver/mywebApp/myXML.xml In the below code which I run in Console Application, bookcollection has null Books field :( <books> <book id="5352"> <date>1986-05-05</date> <title> Alice in chains </title> </book> <book id="4334"> <date>1986-05-05</date> <title> 1000 ways to heaven </title> </book> <book id="1111"> <date>1986-05-05</date> <title> Kitchen and me </title> </book> </books> XmlDocument doc = new XmlDocument(); doc.Load("http://myserver/mywebapp/myXML.xml"); BookCollection books = new BookCollection(); XmlNodeReader reader2 = new XmlNodeReader(doc.DocumentElement); XmlSerializer ser2 = new XmlSerializer(books.GetType()); object obj = ser2.Deserialize(reader2); BookCollection books2= (BookCollection)obj; using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { [Serializable()] public class Book { [System.Xml.Serialization.XmlAttribute("id")] public string id { get; set; } [System.Xml.Serialization.XmlElement("date")] public string date { get; set; } [System.Xml.Serialization.XmlElement("title")] public string title { get; set; } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Xml.Serialization; namespace ConsoleApplication1 { [Serializable()] [System.Xml.Serialization.XmlRootAttribute("books", Namespace = "", IsNullable = false)] public class BookCollection { [XmlArray("books")] [XmlArrayItem("book", typeof(Book))] public Book[] Books { get; set; } } }

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  • Blocking problem Deserializing XML to object problem

    - by fernando
    I have a blocking problem I have XML file under some url http://myserver/mywebApp/myXML.xml In the below code which I run in Console Application, bookcollection has null Books field :( <books> <book id="5352"> <date>1986-05-05</date> <title> Alice in chains </title> </book> <book id="4334"> <date>1986-05-05</date> <title> 1000 ways to heaven </title> </book> <book id="1111"> <date>1986-05-05</date> <title> Kitchen and me </title> </book> </books> XmlDocument doc = new XmlDocument(); doc.Load("http://myserver/mywebapp/myXML.xml"); BookCollection books = new BookCollection(); XmlNodeReader reader2 = new XmlNodeReader(doc.DocumentElement); XmlSerializer ser2 = new XmlSerializer(books.GetType()); object obj = ser2.Deserialize(reader2); BookCollection books2= (BookCollection)obj; using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { [Serializable()] public class Book { [System.Xml.Serialization.XmlAttribute("id")] public string id { get; set; } [System.Xml.Serialization.XmlElement("date")] public string date { get; set; } [System.Xml.Serialization.XmlElement("title")] public string title { get; set; } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Xml.Serialization; namespace ConsoleApplication1 { [Serializable()] [System.Xml.Serialization.XmlRootAttribute("books", Namespace = "", IsNullable = false)] public class BookCollection { [XmlArray("books")] [XmlArrayItem("book", typeof(Book))] public Book[] Books { get; set; } } }

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  • Noob Objective-C/C++ - Linker Problem/Method Signature Problem

    - by Josh
    There is a static class Pipe, defined in C++ header that I'm including. The static method I'm interested in calling (from Objetive-c) is here: static ERC SendUserGet(const UserId &_idUser,const GUID &_idStyle,const ZoneId &_idZone,const char *_pszMsg); I have access to an objetive-c data structure that appears to store a copy of userID, and zoneID -- it looks like: @interface DataBlock : NSObject { GUID userID; GUID zoneID; } Looked up the GUID def, and its a struct with a bunch of overloaded operators for equality. UserId and ZoneId from the first function signature are #typedef GUID Now when I try to call the method, no matter how I cast it (const UserId), (UserId), etc, I get the following linker error: Ld build/Debug/Seeker.app/Contents/MacOS/Seeker normal i386 cd /Users/josh/Development/project/Mac/Seeker setenv MACOSX_DEPLOYMENT_TARGET 10.5 /Developer/usr/bin/g++-4.2 -arch i386 -isysroot /Developer/SDKs/MacOSX10.5.sdk -L/Users/josh/Development/TS/Mac/Seeker/build/Debug -L/Users/josh/Development/TS/Mac/Seeker/../../../debug -L/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1 -F/Users/josh/Development/TS/Mac/Seeker/build/Debug -filelist /Users/josh/Development/TS/Mac/Seeker/build/Seeker.build/Debug/Seeker.build/Objects-normal/i386/Seeker.LinkFileList -mmacosx-version-min=10.5 -framework Cocoa -framework WebKit -lSAPI -lSPL -o /Users/josh/Development/TS/Mac/Seeker/build/Debug/Seeker.app/Contents/MacOS/Seeker Undefined symbols: "SocPipe::SendUserGet(_GUID const&, _GUID const&, _GUID const&, char const*)", referenced from: -[PeoplePaneController clickGet:] in PeoplePaneController.o ld: symbol(s) not found collect2: ld returned 1 exit status Is this a type/function signature error, or truly some sort of linker error? I have the headers where all these types and static classes are defined #imported -- I tried #include too, just in case, since I'm already stumbling :P Forgive me, I come from a web tech background, so this c-style memory management and immutability stuff is super hazy. Edit: Added full linker error text. Changed "function" to "method" Thanks, Josh

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  • Noob Objective-C/C++ - Linker Problem/Function Def Problem

    - by Josh
    There is a static class Pipe, defined in C++ header that I'm including. The function I'm interested in calling (from Objetive-c) is here: static ERC SendUserGet(const UserId &_idUser,const GUID &_idStyle,const ZoneId &_idZone,const char *_pszMsg); I have access to an objetive-c data structure that appears to store a copy of userID, and zoneID -- it looks like: @interface DataBlock : NSObject { GUID userID; GUID zoneID; } Looked up the GUID def, and its a struct with a bunch of overloaded operators for equality. UserId and ZoneId from the first function signature are #typedef GUID Now when I try to call the function, no matter how I cast it (const UserId), (UserId), etc, I get the following linker error: "Pipe::SendUserGet(_GUID const&, _GUID const&, _GUID const&, char const*)", referenced from: -[PeoplePaneController clickGet:] in PeoplePaneController.o Is this a type/function signature error, or truly some sort of linker error? I have the headers where all these types and static classes are defined #imported -- I tried #include too, just in case, since I'm already stumbling :P Forgive me, I come from a web tech background, so this c-style memory management and immutability stuff is super hazy. Thanks, Josh

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  • Where can I find this hotfix?

    - by speeder
    I've got a problem, and seemly the solution is a hot fix mentioned here. The problem is that the link there pointing to location of the hotfix is broken, leading to a search page on MS site. And looking around I figured that the easiest way is to phone Microsoft, but I live in other country. So, how I fix the problem described in the KB page that I linked? EDIT: Extra note: I DO have the SP3... :(

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  • What is the ambiguity in this piece of code?

    - by cambr
    #include <iostream> using namespace std; class A { public: void eat(){ cout<<"A";} }; class B: public A { public: void eat(){ cout<<"B";} }; class C: public A { public: void eat(){ cout<<"C";} }; class D: public B,C { public: void eat(){ cout<<"D";} }; int main(){ A *a = new D(); a->eat(); } I am not sure this is called diamond problem or not, but why doesn't this work? When I said, a->eat() (remember eat() is not virtual), there is only one possible eat() to call, that of A. Why then, do I get this error: 'A' is an ambiguous base of 'D'

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  • Solr date range problem and specific date problem

    - by Hamid
    I index some data include date in solr but when search for specific date, i get some record (not all record) include some record in next day for example: http://localhost:8080/solr/select/?q=pubdate:[2010-03-25T00:00:00Z TO 2010-03-25T23:59:59Z]&start=0&rows=10&indent=on&sort=pubdate desc i have 625000 record in 2010-03-25 but above query result return 325412 that include 14 record from 2010-03-26. Also i try with below query, but not get right result http://localhost:8080/solr/select/?q=pubdate:"2010-03-25T00:00:00Z"&start=0&rows=10&indent=on&sort=pubdate desc How to get right result for specific date ??? Could you please help me? Thanks in advanced Hamid

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  • "Fuzzy" Display Problems on New OpenSUSE 11.3 Install

    - by Kryten
    Hi, I have a old Desktop that has a new installation of OpenSUSE 11.3 on it. To get straight to the point, whenever I try to start-up OpenSUSE, my display goes "fuzzy" (almost like a badly tuned TV) and sometimes (not always) my monitor goes black and says "Out of Range: 15.6kHz/49Hz": I assumed that this was a driver problem, so I download the drivers from nvidia and ran the shell script, completed and rebooted. Then OpenSUSE failed to boot with something like "nscd failed to start". At that point I decided to re-install and I did, but this time I tried un-checking "Automatic Configuration" to see if that helped. Got through the install and still have a problem. Unfortunately, my Linux troubleshooting skills are non-existent, so has anyone got any ideas on what could be the problem (is it the display driver?) and how I can fix the problem?

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  • Master File Table Corrupt, any way to save data?

    - by domen
    hi. I've used search, but none of the results match my problem so I didn't have to ask separate question. I've Installed Windows 7 RTM recently and since then partitions located on one of my HDDs have gone "crazy". They used to "freeze" and didn't open in explorer for some time (minute or two, usually), sometimes all partitions of the drive wouldn't show until reboot and finally, one of those partitions started showing "disk structure is corrupted and unreadable" warning, it appeared in Disk Management window as RAW and chkdsk showed "mft corrupt". There were no important data on the partition and I didn't have enough time to analyze the problem at the moment, so I just reformatted it and ran antivirus scan on system. After that problem settled for some time, but yesterday the problematic HDD vanished again from the system. After reboot chkdsk identified mft of four partitions corrupt and now they are all in same conditions as the above mentioned one. But the difference is that the files stored in them are extremely important. and just for info: I upgraded from Win7 build 7077, but had some performance issues, so I reformatted system drive and installed fresh Win7 RTM on it. I've downloaded TestDisk and it shows all the partitions marked as NTFS (not RAW) and my knowledge of the program wasn't sufficient to obtain any other info from it :-) and the images that could help describe the problem (sorry, I'm not allowed to post images and more than one hyperlink): http:// img22.imageshack.us/img22/5909/chkdskz.jpg http:// img198.imageshack.us/img198/5576/computeray.jpg I'm interested, is there a way to let me restore the MFT or just access files so I can backup them before reformatting the drive. Thanks for your time. :) P.S. my reformatted drive is showing no problems, could there be a problem with windows 7 itself? I googled, but with no results.

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  • Please quickly help with this problem I got 52 minutes left.

    - by Hamish Grubijan
    Write a program that prints the numbers from 1 to 100. But for multiples of three print "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers which are multiples of both three and five print "FizzBuzz". Woman said use any common language. Please make it short and test it. My screen is small. Thanks. P.S. I have test anxiety particularly after talking to people in suits. I also stayed up all night studying Java codes.

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  • Xp SP3 - Non-Functioning

    - by Josh
    Ok Here is a crazy problem, I have a HP dv6000 Laptop that can no longer hold a charge, so I hooked it up to my TV, bought a wireless mouse and keyboard and configured xp to run with the lid closed, It has medium to heavy usage mainly just streaming from sites like Netfilx, Hulu, ABC, etc. And playing movies I ripped of dvd. It ran fine for a while but recently it has been having some weird problems: Problem one: I used to use firefox but now when run it I can type but as soon as I click something it just shuts down, completely, I can't even close it unless I use taskmanager to do it. So I went and got google chrome which is better but still hit or miss, but never completely shuts down, I just can't click anything or type anything, or sometimes I just can't type anything or vice versa. Also when I open a new tab, and try to move back to my old one, it automatically closes the old tab when I click on it. Problem two: When using the internet I can't use any other application or anything windows (ie. Windows explorer) until I force quit all browsers with taskmanger. The reason I can't run anything is because I can't click on it. Problem three: When I try to play a movie (with vlc) Once it starts playing I can't click on anything, but I can use hotkeys, and once it stops everything is fine again. Well I hope somebody knows whats going on because I have no clue, If you need clarification or more info on something I would be happy to provide it...

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  • Come up with a real-world problem in which only the best solution will do (a problem from Introduction to algorithms) [closed]

    - by Mike
    EDITED (I realized that the question certainly needs a context) The problem 1.1-5 in the book of Thomas Cormen et al Introduction to algorithms is: "Come up with a real-world problem in which only the best solution will do. Then come up with one in which a solution that is “approximately” the best is good enough." I'm interested in its first statement. And (from my understanding) it is asked to name a real-world problem where only the exact solution will work as opposed to a real-world problem where good-enough solution will be ok. So what is the difference between the exact and good enough solution. Consider some physics problem for example the simulation of the fulid flow in the permeable medium. To make this simulation happen some simplyfing assumptions have to be made when deriving a mathematical model. Otherwise the model becomes at least complex and unsolvable. Virtually any particle in the universe has its influence on the fluid flow. But not all particles are equal. Those that form the permeable medium are much more influental than the ones located light years away. Then when the mathematical model needs to be solved an exact solution can rarely be found unless the mathematical model is simple enough (wich probably means the model isn't close to reality). We take an approximate numerical method and after hours of coding and days of verification come up with the program or algorithm which is a solution. And if the model and an algorithm give results close to a real problem by some degree that is good enough soultion. Its worth noting the difference between exact solution algorithm and exact computation result. When considering real-world problems and real-world computation machines I believe all physical problems solutions where any calculations are taken can not be exact because universal physical constants are represented approximately in the computer. Any numbers are represented with the limited precision, at least limited by amount of memory available to computing machine. I can imagine plenty of problems where good-enough, good to some degree solution will work, like train scheduling, automated trading, satellite orbit calculation, health care expert systems. In that cases exact solutions can't be derived due to constraints on computation time, limitations in computer memory or due to the nature of problems. I googled this question and like what this guy suggests: there're kinds of mathematical problems that need exact solutions (little note here: because the question is taken from the book "Introduction to algorithms" the term "solution" means an algorithm or a program, which in this case gives exact answer on each input). But that's probably more of theoretical interest. So I would like to narrow down the question to: What are the real-world practical problems where only the best (exact) solution algorithm or program will do (but not the good-enough solution)? There are problems like breaking of cryptographic ciphers where only exact solution matters in practice and again in practice the process of deciphering without knowing a secret should take reasonable amount of time. Returning to the original question this is the problem where good-enough (fast-enough) solution will do there's no practical need in instant crack though it's desired. So the quality of "best" can be understood in any sense: exact, fastest, requiring least memory, having minimal possible network traffic etc. And still I want this question to be theoretical if possible. In a sense that there may be example of computer X that has limited resource R of amount Y where the best solution to problem P is the one that takes not more than available Y for inputs of size N*Y. But that's the problem of finding solution for P on computer X which is... well, good enough. My final thought that we live in a world where it is required from programming solutions to practical purposes to be good enough. In rare cases really very very good but still not the best ones. Isn't it? :) If it's not can you provide an example? Or can you name any such unsolved problem of practical interest?

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