Search Results

Search found 313 results on 13 pages for 'logically'.

Page 10/13 | < Previous Page | 6 7 8 9 10 11 12 13  | Next Page >

• Which is better? OpenCyc or ConceptNet?

  - by Daniel Loureiro

  Hi, I'm doing a NLP project where I need to recognise concepts in sentences to find other similar concepts. I do this to infer word valences from a list I already have. I started using WordNet, but it gave many contradictory results. By contradictory results I mean word expansions that had contradictory valences. So now I'm looking into ConceptNet and OpenCyc. I've already implemented ConceptNet and it was all very easy and I love it. Problem is that OpenCyc appears to have a much larger and more logically rigid database, which is important when I found so many "contradictions" on WordNet... But I wouldn't know because I haven't tried it. Could someone tell me if it's worth going through the (considerable, for me) effort to implement OpenCyc, or is ConceptNet good enough to infer word valences? Are they that different? I'll be happy to explain myself further, if needed. Trying to keep it short for now! Thanks!

  Read the article

• Subqueries on Java GAE Datastore

  - by Dmitry

  I am trying to create a database of users with connection between users (friends list). There are 2 main tables: UserEntity (main field id) and FriendEntity with fields: - initiatorId - id of user who initiated the friendship - friendId - id of user who has been invited. Now I am trying to fetch all friends of one particular user and encountered some problems with using subqueries in JDO here. Logically the query should be something like this: SQL: SELECT * FROM UserEntity WHERE EXISTS (SELECT * FORM FriendEntity WHERE (initiatorId == UserEntity.id && friendId == userId) || (friendId == UserEntity.id && initiatorId == userId)) or SELECT * FROM UserEntity WHERE userId IN (SELECT * FROM FriendEntity WHERE initiatorId == UserEntity.id) OR userId IN (SELECT * FROM FriendEntity WHERE friendId == UserEntity.id) So to replicate the last query in JDOQL, I tried to do the following: Query friendQuery = pm.newQuery(FriendEntity.class); friendQuery.setFilter("initiatorId == uidParam"); friendQuery.setResult("friendId"); Query initiatorQuery = pm.newQuery(FriendEntity.class); initiatorQuery.setFilter("friendId == uidParam"); initiatorQuery.setResult("initiatorId"); Query query = pm.newQuery(UserEntity.class); query.setFilter("initiatorQuery.contains(id) || friendQuery.contains(id)"); query.addSubquery(initiatorQuery, "List initiatorQuery", null, "String uidParam"); query.addSubquery(friendQuery, "List friendQuery", null, "String uidParam"); query.declareParameters("String uidParam"); List<UserEntity> friends = (List<UserEntity>) query.execute(userId); In result I get the following error: Unsupported method while parsing expression. Could anyone help with this query please?

  Read the article

• PHP Single Sign On (SSO) generating new session id

  - by bigstylee

  I am trying to create a single sign on process. The method I have implemented makes use of storing session data in a database. When a new user comes to the website (www.example2.com) a table of authentication is checked. As this is their first visit to the website, there will be no match. The browser is redicted to the authentication server www.example1.com/authenticate.php?session_id=ABC123 where ABC123 represents the session id created on www.example2.com. THe session id which is then generated on www.example1.com is stored along side the session id using the parameter set in the URL. The user is then redirected back to the www.example2.com and a match of session ids should be found. This WAS working fine in FireFox but when I tried it in Chrome I noticed that the session id being generated when the browser is redirected back to www.example2.com is a new session id. As a result an infinite loop is created. This behaviour has not manifested itself in FireFox aswell. What is causing the new session id to be generated? More importantly, what can I do to stop it? Thanks in advance! EDIT I had a logically error that was causing an infinite loop. This now works fine again in FireFox but the infinite loop is still occuring in Chrome and Internet Explorer.

  Read the article

• Segmentation in Linux : Segmentation & Paging are redundant?

  - by claws

  Hello, I'm reading "Understanding Linux Kernel". This is the snippet that explains how Linux uses Segmentation which I didn't understand. Segmentation has been included in 80 x 86 microprocessors to encourage programmers to split their applications into logically related entities, such as subroutines or global and local data areas. However, Linux uses segmentation in a very limited way. In fact, segmentation and paging are somewhat redundant, because both can be used to separate the physical address spaces of processes: segmentation can assign a different linear address space to each process, while paging can map the same linear address space into different physical address spaces. Linux prefers paging to segmentation for the following reasons: Memory management is simpler when all processes use the same segment register values that is, when they share the same set of linear addresses. One of the design objectives of Linux is portability to a wide range of architectures; RISC architectures in particular have limited support for segmentation. All Linux processes running in User Mode use the same pair of segments to address instructions and data. These segments are called user code segment and user data segment , respectively. Similarly, all Linux processes running in Kernel Mode use the same pair of segments to address instructions and data: they are called kernel code segment and kernel data segment , respectively. Table 2-3 shows the values of the Segment Descriptor fields for these four crucial segments. I'm unable to understand 1st and last paragraph.

  Read the article

• Testing for interface implementation in WCF/SOA

  - by rabidpebble

  I have a reporting service that implements a number of reports. Each report requires certain parameters. Groups of logically related parameters are placed in an interface, which the report then implements: [ServiceContract] [ServiceKnownType(typeof(ExampleReport))] public interface IService1 { [OperationContract] void Process(IReport report); } public interface IReport { string PrintedBy { get; set; } } public interface IApplicableDateRangeParameter { DateTime StartDate { get; set; } DateTime EndDate { get; set; } } [DataContract] public abstract class Report : IReport { [DataMember] public string PrintedBy { get; set; } } [DataContract] public class ExampleReport : Report, IApplicableDateRangeParameter { [DataMember] public DateTime StartDate { get; set; } [DataMember] public DateTime EndDate { get; set; } } The problem is that the WCF DataContractSerializer does not expose these interfaces in my client library, thus I can't write the generic report generating front-end that I plan to. Can WCF expose these interfaces, or is this a limitation of the serializer? If the latter case, then what is the canonical approach to this OO pattern? I've looked into NetDataContractSerializer but it doesn't seem to be an officially supported implementation (which means it's not an option in my project). Currently I've resigned myself to including the interfaces in a library that is common between the service and the client application, but this seems like an unnecessary extra dependency to me. Surely there is a more straightforward way to do this? I was under the impression that WCF was supposed to replace .NET remoting; checking if an object implements an interface seems to be one of the most basic features required of a remoting interface?

  Read the article

• How to model parent to child pair in MySQL (SQL)

  - by mikeschuld

  I have a data model that includes element types Stage, Actor, and Form. Logically, Stages can be assigned pairs of ( Form <--- Actor ) which can be duplicated many times (i.e. same person and same form added to the same stage at a later date/time). Right now I am modeling this with these tables: Stage Form Actor Form_Actor _______________ |Id | |FormId | --> Id in Form |ActorId | --> Id in Actor Stage_FormActor __________________ |Id | |StageId | --> Id in Stage |FormActorId | --> Id in Form_Actor I am using CodeSmith to generate the data layer for this setup and none of the templates really know how to handle this type of relationship correctly when generating classes. Ideally, the ORM would have Stage.FormActors where FormActor would be the pair Form, Actor. Is this the correct way to model these relationships. I have tried using all three Ids in one table as well Stage_Form_Actor ______________ |Id | |StageId | --> Id in Stage |FormId | --> Id in Form |ActorId | --> Id in Actor This doesn't really get generated very well either. Ideas?

  Read the article

• RegisterClientScriptInclude doesn't work for some reason...

  - by Andrew

  Hey, I've spent at least 2 days trying anything and googling this...but for some reason I can't get RegisterClientScriptInclude to work the way everyone else has it working? First off, I am usting .NET 3.5 Ajax,...and I am including javascript in my partial page refreshes...using this code: ScriptManager.RegisterClientScriptBlock(this, typeof(Page), "MyClientCode", script, true); It works perfectly, my javascript code contained in the script variable is included every partial refresh. The javascript in script is actually quite extensive though, and I would like to store it in a .js file,..so logically I make a .js file and try to include it using RegisterClientScriptInclude ...however i can't for the life of my get this to work. here's the exact code: ScriptManager.RegisterClientScriptInclude(this, typeof(Page), "mytestscript", "/js/testscript.js"); the testscript.js file is only included in FULL page refreshes...ie. when I load the page, or do a full postback....i can't get the file to be included in partial refreshes...have no idea why..when viewing the ajax POST in firebug I don't see a difference whether I include the file or not.... both of the ScriptManager Includes are being ran from the exact same place in "Page_Load"...so they should execute every partial refresh (but only the ScriptBlock does). anyways,..any help or ideas,..or further ways I can trouble shoot this problem, would be appreciated. Thanks, Andrew

  Read the article

• How to create closed areas (convex polygons) from set of line segments ?

  - by Marten

  The following problem is in 2D, so some simplifications can be made when suggesting answers. I need to create closed areas (defined either by line segments or just set of points - convex polygon) from a set of points/line segments. Basically I used Voronoi to generate "roads". Then I changed some of the data. Now I need a way to loop through that data (which is still line segments but doesn't comply with Voronoi anymore) and generate "neigbourhoods" that are bordered with the "roads". I looked at some graph diagrams and shortest path theories, but I could not figure it out. Logically it could be done by starting at left edge from one point, finding the way back to that point using the shortest path with available lines (using only clockwise directions). Then mark this line set down and remove from the data. Then you can repeat the same process and get all the areas like that. I tried to implement that but it did not get me anywhere as I could not figure out a way to write a C++ code that could do that. Problem was with choosing the most counterclockwise line from available lines from a specific point. All angle based math I did gave wrong answers because the way sin/cos are implemented in c++. So to summarize - if you can help me with a totally new approach to the problem its good, if not could you help me find a way to write the part of the code that finds the shortest clockwise path back to the beginning point using the line segment set as paths back. Thank you for your help!

  Read the article

• jQueryUI Modal confirmation dialog on form submission

  - by DavidYell

  I am trying to get a modal confirmation dialog working when a user submits a form. My approach, I thought logically, would be to catch the form submission. My code is as follows, $('#multi-dialog-confirm').dialog({ autoOpen: false, height: 200, modal: true, resizable: false, buttons: { 'Confirm': function(){ //$(this).dialog('close'); return true; }, 'Cancel': function(){ $(this).dialog('close'); return false; } } }); $('#completeform').submit(function(e){ e.preventDefault(); var n = $('#completeform input:checked').length; if(n == 0){ alert("Please check the item and mark as complete"); return false; }else{ var q = $('#completeform #qty').html(); if(q > 1){ $('#multi-dialog-confirm').dialog('open'); } } //return false; }); So I'm setting up my dialog first. This is because I'm pretty certain that the scope of the dialog needs to be at the same level as the function which calls it. However, the issue is that when you click 'Confirm' nothing happens. The submit action does not continue. I've tried $('#completeform').submit(); also, which doesn't seem to work. I have tried removing the .preventDefault() to ensure that the form submission isn't completely cancelled, but it doesn't seem to make a difference between that and returning false. Not checking the box, show and alert fine. Might change to dialog at some point ;), clicking 'Cancel' closes the dialog and remains on the page, but the elusive 'Confirm' buttons seems to not continue with the form submission event. If anyone can help, I'd happily share my lunch with you! ;)

  Read the article

• Add webservice reference, the classes in different file

  - by ArunDhaJ

  Hi, When I add webservice as service reference in my .Net project, it creates a service folder within "Service References". All the interfaces and classes are contained within that service folder. I wanted to know how to split the interface's method and classes. Actually I wanted the web service reference to import classes defined in different dll. I wanted to define this way because of my design constraints. I've 3 layered application. Of which third layer is communication layer which holds all web service references. second is business layer and first is presentation layer. If the class declarations are in layer-3 and I'm accessing those classes from presentation layer, it is logically a cross-layer-access-violation. Instead, I wanted a separate project which holds only the class declarations and this would be used in all 3 layers. I didn't faced any problems to achieve this with layer-1 and layer-2. But, I'm not sure how to make communication layer to use this common declaration dll. Your suggestion would help me to design my application better. Thanks in advance Regards ArunDhaJ

  Read the article

• SQL - Multiple join conditions using OR?

  - by Brandi

  I have a query that is using multiple joins. The goal is to say "Out of table A, give me all the customer numbers in which you can match table A's EmailAddress with either email_to or email_from of table B. Ignore nulls, internal emails, etc.". It seems like it would be better to use an or condition in the join than multiple joins since it is the same table. When I try to use AND/OR it does not give the behaviour I expect... AND finishes in a reasonable time, but yields no results (I know that there are matches, so it must be some flaw in my logic) and OR never finishes (I have to kill it). Here is example code to illustrate the question: --my original query SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from RIGHT JOIN B f WITH (NOLOCK) ON a.EmailAddress = f.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR f.email_to IS NOT NULL) Here is what I tried, (I am attempting logical equivalence): SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from OR a.EmailAddress = e.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR e.email_to IS NOT NULL) So my question is two-fold: Why does having AND in the above query work in a few seconds and OR goes for minutes and never completes? What am I missing to make a logically equivalent statement that has only one join?

  Read the article

• Two radically different queries against 4 mil records execute in the same time - one uses brute force.

  - by IanC

  I'm using SQL Server 2008. I have a table with over 3 million records, which is related to another table with a million records. I have spent a few days experimenting with different ways of querying these tables. I have it down to two radically different queries, both of which take 6s to execute on my laptop. The first query uses a brute force method of evaluating possibly likely matches, and removes incorrect matches via aggregate summation calculations. The second gets all possibly likely matches, then removes incorrect matches via an EXCEPT query that uses two dedicated indexes to find the low and high mismatches. Logically, one would expect the brute force to be slow and the indexes one to be fast. Not so. And I have experimented heavily with indexes until I got the best speed. Further, the brute force query doesn't require as many indexes, which means that technically it would yield better overall system performance. Below are the two execution plans. If you can't see them, please let me know and I'll re-post then in landscape orientation / mail them to you. Brute-force query: Index-based exception query: My question is, based on the execution plans, which one look more efficient? I realize that thing may change as my data grows.

  Read the article

• Editing a remote file on-the-fly with PHP

  - by user275074

  Hi, I have a requirement to edit a remote text file on-the-fly, the content of which currently stands at ~1Mb. I have tried a couple of approaches and both seem to be clunky or hog memory which I can't rely on. Thinking out logically what I'm trying to achieve is: FTP to a remote server. Download a copy of the file for backup purposes and store it somewhere locally. Open the remote file and add the necessary lines required. Remove lines from the remote file as per an array of un-required data generated from the local server. Is this possible? I've managed to code steps 1 and 2 but I'm having difficult with 3 and 4. The way I'm doing it now is to use fgets and return the whole string. Really, I don't want to do this as it involves manipulating and re-generating the whole string (and it's large) and then re-inserting it in between two markers in the remote file. Is there no way of manipulating the lines of text in the file on-the-fly?

  Read the article

• Do database engines other than SQL Server behave this way?

  - by Yishai

  I have a stored procedure that goes something like this (pseudo code) storedprocedure param1, param2, param3, param4 begin if (param4 = 'Y') begin select * from SOME_VIEW order by somecolumn end else if (param1 is null) begin select * from SOME_VIEW where (param2 is null or param2 = SOME_VIEW.Somecolumn2) and (param3 is null or param3 = SOME_VIEW.SomeColumn3) order by somecolumn end else select somethingcompletelydifferent end All ran well for a long time. Suddenly, the query started running forever if param4 was 'Y'. Changing the code to this: storedprocedure param1, param2, param3, param4 begin if (param4 = 'Y') begin set param2 = null set param3 = null end if (param1 is null) begin select * from SOME_VIEW where (param2 is null or param2 = SOME_VIEW.Somecolumn2) and (param3 is null or param3 = SOME_VIEW.SomeColumn3) order by somecolumn end else select somethingcompletelydifferent And it runs again within expected parameters (15 seconds or so for 40,000+ records). This is with SQL Server 2005. The gist of my question is this particular "feature" specific to SQL Server, or is this a common feature among RDBMS' in general that: Queries that ran fine for two years just stop working as the data grows. The "new" execution plan destroys the ability of the database server to execute the query even though a logically equivalent alternative runs just fine? This may seem like a rant against SQL Server, and I suppose to some degree it is, but I really do want to know if others experience this kind of reality with Oracle, DB2 or any other RDBMS. Although I have some experience with others, I have only seen this kind of volume and complexity on SQL Server, so I'm curious if others with large complex databases have similar experience in other products.

  Read the article

• Android NDK import-module / code reuse

  - by Graeme

  Morning! I've created a small NDK project which allows dynamic serialisation of objects between Java and C++ through JNI. The logic works like this: Bean - JavaCInterface.Java - JavaCInterface.cpp - JavaCInterface.java - Bean The problem is I want to use this functionality in other projects. I separated out the test code from the project and created a "Tester" project. The tester project sends a Java object through to C++ which then echo's it back to the Java layer. I thought linking would be pretty simple - ("Simple" in terms of NDK/JNI is usually a day of frustration) I added the JNIBridge project as a source project and including the following lines to Android.mk: NDK_MODULE_PATH=.../JNIBridge/jni/" JNIBridge/jni/JavaCInterface/Android.mk: ... include $(BUILD_STATIC_LIBRARY) JNITester/jni/Android.mk: ... include $(BUILD_SHARED_LIBRARY) $(call import-module, JavaCInterface) This all works fine. The C++ files which rely on headers from JavaCInterface module work fine. Also the Java classes can happily use interfaces from JNIBridge project. All the linking is happy. Unfortunately JavaCInterface.java which contains the native method calls cannot see the JNI method located in the static library. (Logically they are in the same project but both are imported into the project where you wish to use them through the above mechanism). My current solutions are are follows. I'm hoping someone can suggest something that will preserve the modular nature of what I'm trying to achieve: My current solution would be to include the JavaCInterface cpp files in the calling project like so: LOCAL_SRC_FILES := FunctionTable.cpp $(PATH_TO_SHARED_PROJECT)/JavaCInterface.cpp But I'd rather not do this as it would lead to me needing to update each depending project if I changed the JavaCInterface architecture. I could create a new set of JNI method signatures in each local project which then link to the imported modules. Again, this binds the implementations too tightly.

  Read the article

• What is the space character for the browser?

  - by Hiro Protagonist

  echo "\n\s\s\s\s\s\s" . "<div id='data-load' data-load='" . $load . "'></div>"; \n works for adding a return in...I tried \s logically for space but this does not work. Keep mind, I don't want this rendered in the browser view...but in the source view ( when you click view-source )...I'm trying to put my html in to a readable form. echo "&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp\n" . "<div id='data-path' data-path='" . $path . "'></div>"; This does not work either. I am composing HTML from PHP... echo " \n" . "<div id='data-load' data-load='" . $load . "'></div>"; This does not work either. Actual Code: public static function setUniversals() { $shared_object = new Shared(); if ( $shared_object->getLoadOn() == 1 ) { $load = 'server'; } else { $load = 'client'; } if( getcwd() === '/home/foo/public_html/develop' ) { $path = 'development'; } else { $path = 'production'; } $shared_object = new Shared(); echo "\n"; echo "\n " . "<div id='data-path' data-path='" . $path . "'></div>"; echo "\n " . "<div id='data-load' data-load='" . $load . "'></div>"; }

  Read the article

• Do you like languages that let you put the "then" before the "if"?

  - by Matt Hamilton

  I was reading through some C# code of mine today and found this line: if (ProgenyList.ItemContainerGenerator.Status != System.Windows.Controls.Primitives.GeneratorStatus.ContainersGenerated) return; Notice that you can tell without scrolling that it's an "if" statement that works with ItemContainerGenerator.Status, but you can't easily tell that if the "if" clause evaluates to "false" the method will return at that point. Realistically I should have moved the "return" statement to a line by itself, but it got me thinking about languages that allow the "then" part of the statement first. If C# permitted it, the line could look like this: return if (ProgenyList.ItemContainerGenerator.Status != System.Windows.Controls.Primitives.GeneratorStatus.ContainersGenerated); This might be a bit "argumentative", but I'm wondering what people think about this kind of construct. It might serve to make lines like the one above more readable, but it also might be disastrous. Imagine this code: return 3 if (x > y); Logically we can only return if x y, because there's no "else", but part of me looks at that and thinks, "are we still returning if x <= y? If so, what are we returning?" What do you think of the "then before the if" construct? Does it exist in your language of choice? Do you use it often? Would C# benefit from it?

  Read the article

• Handling duplicate insertion

  - by Francis

  So I've got this piece of code which, logically should work but Entity Framework is behaving unexpectedly. Here: foreach (SomeClass someobject in allObjects) { Supplier supplier = new Supplier(); supplier.primary_key = someobject.id; supplier.name = someobject.displayname; try { sm.Add(supplier); ro.Created++; } catch (Exception ex) { ro.Error++; } } Here's what I have in sm.Add() public Supplier Add(Supplier supplier) { try { _ctx.AddToSupplier(supplier); _ctx.SaveChanges(); return supplier; } catch (Exception ex) { throw; } } I can have records in allObjects that have the same id. My piece of code needs to support this and just move on to the next and try to insert it, which I think should work. If this happens, an exception is throw, saying that records with dupe PKs cannot be inserted (of course). The exception mentions the value of the PK, for example 1000. All is well, a new supplier is passed to sm.Add() containing a PK that's never been used before. (1001) Weirdly though, when doing SaveChanges(), EF will whine about not being able to insert records with dupe PKs. The exception still mentions 1000 even though supplier contains 10001 in primary_key. I feel this is me not using _ctx properly. Do I need to call something else to sync it ?

  Read the article

• Appropriate uses of Monad `fail` vs. MonadPlus `mzero`

  - by jberryman

  This is a question that has come up several times for me in the design code, especially libraries. There seems to be some interest in it so I thought it might make a good community wiki. The fail method in Monad is considered by some to be a wart; a somewhat arbitrary addition to the class that does not come from the original category theory. But of course in the current state of things, many Monad types have logical and useful fail instances. The MonadPlus class is a sub-class of Monad that provides an mzero method which logically encapsulates the idea of failure in a monad. So a library designer who wants to write some monadic code that does some sort of failure handling can choose to make his code use the fail method in Monad or restrict his code to the MonadPlus class, just so that he can feel good about using mzero, even though he doesn't care about the monoidal combining mplus operation at all. Some discussions on this subject are in this wiki page about proposals to reform the MonadPlus class. So I guess I have one specific question: What monad instances, if any, have a natural fail method, but cannot be instances of MonadPlus because they have no logical implementation for mplus? But I'm mostly interested in a discussion about this subject. Thanks! EDIT: One final thought occured to me. I recently learned (even though it's right there in the docs for fail) that monadic "do" notation is desugared in such a way that pattern match failures, as in (x:xs) <- return [] call the monad's fail. It seems like the language designers must have been strongly influenced by the prospect of some automatic failure handling built in to haskell's syntax in their inclusion of fail in Monad.

  Read the article

• iPhone: How to Determine Average Light/Dark of an Area of an UIImage

  - by TechZen

  I need to place labels with a transparent background over a variable-content UIImage. Readability will vary significantly depending on the relationship between the color of the label's text and the color/luminosity of the area of the image displayed under the label. Since the image will be constantly changing, the color of the label's text needs to change in sync. I have found several techniques for determining the color, perceived luminosity etc of a single pixel. However, I need to rather quickly (while a view loads) determine the rough perceived color/luminosity of an area of the UIImage under the frame of the UILabel. I presume I will also need to measure the alpha because the same color/luminosity looks different at different alpha values. Is there a way to calculate such a value for an area? Will I be reduced to simply summing pixels? If it comes to that, is there an algorithm to accomplish this? I've thought of two possible approaches: Perform some "folding" operations i.e. combining pixels from one half of the area to the other half. Then repeat until I get a single value. Would this be practical? How would you logically combine pixels to average their perceived color/luminosity? Sample a statistically significant number of pixels in the area and then combine them (somehow) to get a rough measure. I think this problem comes up a lot these days with people being so found of customizing backgrounds. Seems like something that would be worth my time to bang out a category or class to handle this and then share it around.

  Read the article

• Web Applications Development: Security practices for Application design

  - by Shyam

  Hi, As I am creating more web applications that are targeted for multiple users, I figured out that I have to start thinking about user management and security. At a glance and in my ideal world, all users belong to a group. Permissions and access is thus defined per group (and inherited by the users of that group). Logically, I have my group of administrators, which are identified with a level "7" (integer) clearance. A group of webusers have for example level "1". This in generally all works great for me, but I need some kind of list that I have to keep in mind how I secure my system, and some general practices. I am not looking for a specific environment; I want to learn the why's and how's. An example is privilege escalation. If someone would be able to "push" themselves inside a group with higher privileges, for example the Administration, how can I prevent this, or what measures should I take to have some sort of precaution? I don't like in that case to walk into a caveat. My question is basically: where can I find a good resource, list, policy, book that explains the security of web applications, the why's, the how's and readable if you don't have any experience in the realm of advanced security? I prefer a free resource, as I believe I couldn't be the first one who thought about this. Thank you for your answers, comments and feedback.

  Read the article

• Updating UI objects in windows forms

  - by P a u l

  Pre .net I was using MFC, ON_UPDATE_COMMAND_UI, and the CCmdUI class to update the state of my windows UI. From the older MFC/Win32 reference: Typically, menu items and toolbar buttons have more than one state. For example, a menu item is grayed (dimmed) if it is unavailable in the present context. Menu items can also be checked or unchecked. A toolbar button can also be disabled if unavailable, or it can be checked. Who updates the state of these items as program conditions change? Logically, if a menu item generates a command that is handled by, say, a document, it makes sense to have the document update the menu item. The document probably contains the information on which the update is based. If a command has multiple user-interface objects (perhaps a menu item and a toolbar button), both are routed to the same handler function. This encapsulates your user-interface update code for all of the equivalent user-interface objects in a single place. The framework provides a convenient interface for automatically updating user-interface objects. You can choose to do the updating in some other way, but the interface provided is efficient and easy to use. What is the guidance for .net Windows Forms? I am using an Application.Idle handler in the main form but am not sure this is the best way to do this. About the time I put all my UI updates in the Idle event handler my app started to show some performance problems, and I don't have the metrics to track this down yet. Not sure if it's related.

  Read the article

• Terminal-based snake game: input thread manipulates output

  - by enlightened

  I'm writing a snake game for the terminal, i.e. output via print. The following works just fine: while status[snake_monad] do print to_string draw canvas, compose_all([ frame, specs, snake_to_hash(snake[snake_monad]) ]) turn! snake_monad, get_dir move! snake_monad, specs sleep 0.25 end But I don't want the turn!ing to block, of course. So I put it into a new Thread and let it loop: Thread.new do loop do turn! snake_monad, get_dir end end while status[snake_monad] do ... # no turn! here ... end Which also works logically (the snake is turning), but the output is somehow interspersed with newlines. As soon as I kill the input thread (^C) it looks normal again. So why and how does the thread have any effect on my output? And how do I work around this issue? (I don't know much about threads, even less about them in ruby. Input and output concurrently on the same terminal make the matter worse, I guess...) Also (not really important): Wanting my program as pure as possible, would it be somewhat easily possible to get the input non-blockingly while passing everything around? Thank you!

  Read the article

• What is better: Developing a Web project in MVC or N -Tier Architecture?

  - by Starx

  I have asked a similar question before and got an convincing answer as well? http://stackoverflow.com/questions/2843311/what-is-difference-of-developing-a-website-in-mvc-and-3-tier-or-n-tier-architectu Due to the conclusion of this question I started developing projects in N-tier Architecture. Just about an hour ago, I asked another question, about what is the best design pattern to create interface? There the most voted answer is suggesting me to use MVC architecture. http://stackoverflow.com/questions/2930300/what-is-the-best-desing-pattern-to-design-the-interface-of-an-webpage Now I am confused, First post suggested me that both are similar, just a difference that in N-tier, the tier are physically and logically separated and one layer has access to the one above and below it but not all the layers. I think ASP.net used 3 Tier architecture while developing applications or Web applications. Where as frameworks like Zend, Symphony they use MVC. I just want to stick to a pattern that is best suitable for WebProject Development? May be this is a very silly confusion? But if someone could clear this confusion, that would be very greatful?

  Read the article

• Efficient Multiplication of Varying-Length #s [Conceptual]

  - by Milan Patel

  Write the pseudocode of an algorithm that takes in two arbitrary length numbers (provided as strings), and computes the product of these numbers. Use an efficient procedure for multiplication of large numbers of arbitrary length. Analyze the efficiency of your algorithm. I decided to take the (semi) easy way out and use the Russian Peasant Algorithm. It works like this: a * b = a/2 * 2b if a is even a * b = (a-1)/2 * 2b + a if a is odd My pseudocode is: rpa(x, y){ if x is 1 return y if x is even return rpa(x/2, 2y) if x is odd return rpa((x-1)/2, 2y) + y } I have 3 questions: Is this efficient for arbitrary length numbers? I implemented it in C and tried varying length numbers. The run-time in was near-instant in all cases so it's hard to tell empirically... Can I apply the Master's Theorem to understand the complexity...? a = # subproblems in recursion = 1 (max 1 recursive call across all states) n / b = size of each subproblem = n / 1 - b = 1 (problem doesn't change size...?) f(n^d) = work done outside recursive calls = 1 - d = 0 (the addition when a is odd) a = 1, b^d = 1, a = b^d - complexity is in n^d*log(n) = log(n) this makes sense logically since we are halving the problem at each step, right? What might my professor mean by providing arbitrary length numbers "as strings". Why do that? Many thanks in advance

  Read the article

< Previous Page | 6 7 8 9 10 11 12 13  | Next Page >