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  • Prove that the set of regular languages is a proper subset of the set of the context-free languages

    - by David Relihan
    I was brushing up (not homework)on some computation-theory and came accross this problem: How can you prove that the set of regular languages is a proper subset of the set of the context-free languages. Now I know a language is regular iff it is accepted by a finite automaton. And I know a language is context-free iff it is accepted by a pushdown automaton. But I'm not sure of what solution is.

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  • Getting Serial Number of the Hard Drive Provided by the manufacturer through PHP

    - by dta
    Getting Serial Number of the Hard Drive Provided by the manufacturer through PHP : How can it be done? I want to store it in a file. OS : windows 2000,XP,ME,Vista... Yes, I want the serial number of the hard drive of the Server. Or can it be done through Adobe AIR? Or can it be done through a C program on Windows? C:\Documents and Settings\Administrator>dir Volume in drive C has no label. Volume Serial Number is BC16-5D5F Is this number : BC16-5d5f unique for a hard drive? How is it different from the manufacturer given serial number? This command **wmic DISKDRIVE GET SerialNumber** Displays only the following text on my Vista Machine : SerialNumber On my XP machine, the command is unrecognized

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  • C++: compute a number's complement and its number of possible mismatches

    - by Eagle
    I got a bit stuck with my algorithm and I need some help to solve my problem. I think an example would explain better my problem. Assuming: d = 4 (maximum number of allowed bits in a number, 2^4-1=15). m_max = 1 (maximum number of allowed bits mismatches). kappa = (maximum number of elements to find for a given d and m, where m in m_max) The main idea is for a given number, x, to compute its complement number (in binary base) and all the possible combinations for up to m_max mismatches from x complement's number. Now the program start to scan from i = 0 till 15. for i = 0 and m = 0, kappa = \binom{d}{0} = 1 (this called a perfect match) possible combinations in bits, is only 1111 (for 0: 0000). for i = 0 and m = 1, kappa = \binom{d}{1} = 4 (one mismatch) possible combinations in bits are: 1000, 0100, 0010 and 0001 My problem was to generalize it to general d and m. I wrote the following code: #include <stdlib.h> #include <iomanip> #include <boost/math/special_functions/binomial.hpp> #include <iostream> #include <stdint.h> #include <vector> namespace vec { typedef std::vector<unsigned int> uint_1d_vec_t; } int main( int argc, char* argv[] ) { int counter, d, m; unsigned num_combination, bits_mask, bit_mask, max_num_mismatch; uint_1d_vec_t kappa; d = 4; m = 2; bits_mask = 2^num_bits - 1; for ( unsigned i = 0 ; i < num_elemets ; i++ ) { counter = 0; for ( unsigned m = 0 ; m < max_num_mismatch ; m++ ) { // maximum number of allowed combinations num_combination = boost::math::binomial_coefficient<double>( static_cast<unsigned>( d ), static_cast<unsigned>(m) ); kappa.push_back( num_combination ); for ( unsigned j = 0 ; j < kappa.at(m) ; j++ ) { if ( m == 0 ) v[i][counter++] = i^bits_mask; // M_0 else { bit_mask = 1 << ( num_bits - j ); v[i][counter++] = v[i][0] ^ bits_mask } } } } return 0; } I got stuck in the line v[i][counter++] = v[i][0] ^ bits_mask since I was unable to generalize my algorithm to m_max1, since I needed for m_max mismatches m_max loops and in my original problem, m is unknown until runtime.

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  • Row Number Transformation

    The Row Number Transformation calculates a row number for each row, and adds this as a new output column to the data flow. The column number is a sequential number, based on a seed value. Each row receives the next number in the sequence, based on the defined increment value. The final row number can be stored in a variable for later analysis, and can be used as part of a process to validate the integrity of the data movement. The Row Number transform has a variety of uses, such as generating surrogate keys, or as the basis for a data partitioning scheme when combined with the Conditional Split transformation. Properties Property Data Type Description Seed Int32 The first row number or seed value. Increment Int32 The value added to the previous row number to make the next row number. OutputVariable String The name of the variable into which the final row number is written post execution. (Optional). The three properties have been configured to support expressions, or they can set directly in the normal manner. Expressions on components are only visible on the hosting Data Flow task, not at the individual component level. Sometimes the data type of the property is incorrectly set when the properties are created, see the Troubleshooting section below for details on how to fix this. Installation The component is provided as an MSI file which you can download and run to install it. This simply places the files on disk in the correct locations and also installs the assemblies in the Global Assembly Cache as per Microsoft’s recommendations. You may need to restart the SQL Server Integration Services service, as this caches information about what components are installed, as well as restarting any open instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. For 2005/2008 Only - Finally you will have to add the transformation to the Visual Studio toolbox manually. Right-click the toolbox, and select Choose Items.... Select the SSIS Data Flow Items tab, and then check the Row Number transformation in the Choose Toolbox Items window. This process has been described in detail in the related FAQ entry for How do I install a task or transform component? We recommend you follow best practice and apply the current Microsoft SQL Server Service pack to your SQL Server servers and workstations, and this component requires a minimum of SQL Server 2005 Service Pack 1. Downloads The Row Number Transformation  is available for SQL Server 2005, SQL Server 2008 (includes R2) and SQL Server 2012. Please choose the version to match your SQL Server version, or you can install multiple versions and use them side by side if you have more than one version of SQL Server installed. Row Number Transformation for SQL Server 2005 Row Number Transformation for SQL Server 2008 Row Number Transformation for SQL Server 2012 Version History SQL Server 2012 Version 3.0.0.6 - SQL Server 2012 release. Includes upgrade support for both 2005 and 2008 packages to 2012. (5 Jun 2012) SQL Server 2008 Version 2.0.0.5 - SQL Server 2008 release. (15 Oct 2008) SQL Server 2005 Version 1.2.0.34 – Updated installer. (25 Jun 2008) Version 1.2.0.7 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. Added the ability to reuse an existing column to hold the generated row number, as an alternative to the default of adding a new column to the output. (18 Jun 2006) Version 1.2.0.7 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. Added the ability to reuse an existing column to hold the generated row number, as an alternative to the default of adding a new column to the output. (18 Jun 2006) Version 1.0.0.0 - Public Release for SQL Server 2005 IDW 15 June CTP (29 Aug 2005) Screenshot Code Sample The following code sample demonstrates using the Data Generator Source and Row Number Transformation programmatically in a very simple package. Package package = new Package(); package.Name = "Data Generator & Row Number"; // Add the Data Flow Task Executable taskExecutable = package.Executables.Add("STOCK:PipelineTask"); // Get the task host wrapper, and the Data Flow task TaskHost taskHost = taskExecutable as TaskHost; MainPipe dataFlowTask = (MainPipe)taskHost.InnerObject; // Add Data Generator Source IDTSComponentMetaData100 componentSource = dataFlowTask.ComponentMetaDataCollection.New(); componentSource.Name = "Data Generator"; componentSource.ComponentClassID = "Konesans.Dts.Pipeline.DataGenerator.DataGenerator, Konesans.Dts.Pipeline.DataGenerator, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b"; CManagedComponentWrapper instanceSource = componentSource.Instantiate(); instanceSource.ProvideComponentProperties(); instanceSource.SetComponentProperty("RowCount", 10000); // Add Row Number Tx IDTSComponentMetaData100 componentRowNumber = dataFlowTask.ComponentMetaDataCollection.New(); componentRowNumber.Name = "FlatFileDestination"; componentRowNumber.ComponentClassID = "Konesans.Dts.Pipeline.RowNumberTransform.RowNumberTransform, Konesans.Dts.Pipeline.RowNumberTransform, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b"; CManagedComponentWrapper instanceRowNumber = componentRowNumber.Instantiate(); instanceRowNumber.ProvideComponentProperties(); instanceRowNumber.SetComponentProperty("Increment", 10); // Connect the two components together IDTSPath100 path = dataFlowTask.PathCollection.New(); path.AttachPathAndPropagateNotifications(componentSource.OutputCollection[0], componentRowNumber.InputCollection[0]); #if DEBUG // Save package to disk, DEBUG only new Application().SaveToXml(String.Format(@"C:\Temp\{0}.dtsx", package.Name), package, null); #endif package.Execute(); foreach (DtsError error in package.Errors) { Console.WriteLine("ErrorCode : {0}", error.ErrorCode); Console.WriteLine(" SubComponent : {0}", error.SubComponent); Console.WriteLine(" Description : {0}", error.Description); } package.Dispose(); Troubleshooting Make sure you have downloaded the version that matches your version of SQL Server. We offer separate downloads for SQL Server 2005, SQL Server 2008 and SQL Server 2012. If you get an error when you try and use the component along the lines of The component could not be added to the Data Flow task. Please verify that this component is properly installed.  ... The data flow object "Konesans ..." is not installed correctly on this computer, this usually indicates that the internal cache of SSIS components needs to be updated. This is held by the SSIS service, so you need restart the the SQL Server Integration Services service. You can do this from the Services applet in Control Panel or Administrative Tools in Windows. You can also restart the computer if you prefer. You may also need to restart any current instances of Business Intelligence Development Studio (BIDS) / Visual Studio that you may be using to build your SSIS packages. Once installation is complete you need to manually add the task to the toolbox before you will see it and to be able add it to packages - How do I install a task or transform component? Please also make sure you have installed a minimum of SP1 for SQL 2005. The IDtsPipelineEnvironmentService was added in SQL Server 2005 Service Pack 1 (SP1) (See  http://support.microsoft.com/kb/916940). If you get an error Could not load type 'Microsoft.SqlServer.Dts.Design.IDtsPipelineEnvironmentService' from assembly 'Microsoft.SqlServer.Dts.Design, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91'. when trying to open the user interface, it implies that your development machine has not had SP1 applied. Very occasionally we get a problem to do with the properties not being created with the correct data type. Since there is no way to programmatically to define the data type of a pipeline component property, it can only infer it. Whilst we set an integer value as we create the property, sometimes SSIS decides to define it is a decimal. This is often highlighted when you use a property expression against the property and get an error similar to Cannot convert System.Int32 to System.Decimal. Unfortunately this is beyond our control and there appears to be no pattern as to when this happens. If you do have more information we would be happy to hear it. To fix this issue you can manually edit the package file. In Visual Studio right click the package file from the Solution Explorer and select View Code, which will open the package as raw XML. You can now search for the properties by name or the component name. You can then change the incorrect property data types highlighted below from Decimal to Int32. <component id="37" name="Row Number Transformation" componentClassID="{BF01D463-7089-41EE-8F05-0A6DC17CE633}" … >     <properties>         <property id="38" name="UserComponentTypeName" …>         <property id="41" name="Seed" dataType="System.Int32" ...>10</property>         <property id="42" name="Increment" dataType="System.Decimal" ...>10</property>         ... If you are still having issues then contact us, but please provide as much detail as possible about error, as well as which version of the the task you are using and details of the SSIS tools installed.

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  • Maximizing the number of true concurrent / parrallel http requests in Silverlight

    - by Clems
    Hi all. I'm using SL 4 beta and my app needs to do a lot of small http requests to the server. I believe that when exceeding the number of allowed concurrent requests, the subsequent requests are put in a queue. I am also aware that SL 4 has both a http browser stack and a http client stack, with both different limit in terms of the number of concurrent requests. Let's say call those limits MAX_BROWSER and MAX_CLIENT. Also I think I read somewhere that the number of concurrent requests is limited per domain, not overall. But I'm sure if this applies to both the http client stack. That means that you CAN have MAX_BROWSER requests to domain1.com AND MAX_BROWSER requests to domain2.com at the same time. And I even believe that sub domains are considered different so you can also have MAX_BROWSER requests to domain1.com AND MAX_BROWSER requests to sub.domain1.com at the same time. I have ownership of the services and domain names so I could easily setup sub domains for my services. Given those considerations I'm trying to optimize the number of concurrent http requests to my server. Here are few questions ? Is is possible to use both stack at the same time ? Is the subdomain/domain story true for both stacks ? None ? If so that would mean that I could potentially have a number of concurrent requests equal to : (MAX_BROWSER + MAX_CLIENT) * NUMBER_OF_DOMAINS which would be fairly good. Is this correct ? I'm kind of sharing my morning thoughts here, hoping somebody has experimented with those things. Thank you.

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  • Probability Random Number Generator

    - by Excl
    Let's say I'm writing a simple luck game - each player presses Enter and the game assign him a random number between 1-6. Just like a cube. At the end of the game, the player with the highest number wins. Now, let's say I'm a cheater. I want to write the game so player #1 (which will be me) has a probability of 90% to get six, and 2% to get each of the rest numbers (1, 2, 3, 4, 5). So, how can I generate a number random, and set the probability for each number? Thanks.

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  • Need a regular expression for an Irish phone number

    - by Eoghan O'Brien
    I need to validate an Irish phone number but I don't want to make it too user unfriendly, many people are used to writing there phone number with brackets wrapping their area code followed by 5 to 7 digits for their number, some add spaces between the area code or mobile operator. The format of Irish landline numbers is an area code of between 1 and 4 digits and a number of between 5 to 8 digits. e.g. (021) 9876543 (01)9876543 01 9876543 (0402)39385 I'm looking for a regular expression for Javascript/PHP. Thanks.

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  • Determine phone number based on time zone?

    - by Zachary Burt
    I have a (potentially international) phone number. It may or may not have a country code prefix. Does anyone know of a database that will help me map phone number = time zone? I would even just like to map phone number = country, since I can probably create country = time zone by scraping existing data on the web. This is a more complicated problem than it looks; for example, how do I know if it's a US-based number -- e.g. is it a USA area code, or an international country calling code? Any language is fine; I can port it.

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  • How to adjust the distribution of values in a random data stream?

    - by BCS
    Given a infinite stream of random 0's and 1's that is from a biased (e.g. 1's are more common than 0's by a know factor) but otherwise ideal random number generator, I want to convert it into a (shorter) infinite stream that is just as ideal but also unbiased. Looking up the definition of entropy finds this graph showing how many bits of output I should, in theory, be able to get from each bit of input. The question: Is there any practical way to actually implement a converter that is nearly ideally efficient?

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  • Sets, Surrogates, Normalisation, Referential Integrity - the Theory with example Scaling considerati

    - by tonyrogerson
    The Slides and Demo's for the SQLBits session I did today at SQL Bits in London are attached. The Agenda was... Thinking in Sets Surrogate Keys ú What they are ú Comparison NEWID, NEWSEQUENTIALID, IDENTITY ú Fragmenation Normalisation ú An introduction – what is it? Why use it? ú Joins – Pre-filter problems, index intersection ú Fragmentation again Referential Integrity ú Optimiser -> Query rewrite ú Locking considerations around Foreign Keys and Declarative RI (using Triggers)...(read more)

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  • The Grand Unified Framework Theory

    Tom Janssens left a comment: What still bugs me is that we do not have a unified pattern for all .net dev (using modelbinders and icommand for example...) But, Tom we are pretty close. At least as close as we should be, I think. With .NET there are plenty of low level patterns we can reuse regardless of the application platform or architecture. Stuff like: Asynchronous programming with events or the TPL. Object queries with LINQ. Resource management with IDispose. At a higher...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • PageRank is the Best Indicator of Competition Strength For a Keyword in SEO - New Verifiable Theory

    The major argument against PageRank in SEO is that pages with zero PageRank can be in the top positions even for highly competitive keywords. However, we are left with requiring an explanation as to why "PageRank is Google's view of the importance of this page." It becomes apparent that either Google is misleading us or we have all been misinterpreting Google's statement. From extensive evaluation of the top Google search engine results pages for hundreds of keywords, the author observed that those high positioned web pages with PageRanks of zero have a home page with higher PageRanks, usually three or more.

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  • Need in obtaining a specific local telephone number [closed]

    - by Brett
    I am wanting a local phone number that I like. I have found one that I like. When I call the number that I want it says "this number has not been allocated" I have looked up and found the company that owns that number. How do I go about acquiring that number from the company. I spoke with someone who sells major phone packages and he said that if I signed up with them he could get the number for me. He said that there is a change of ownership form that the send to get the number. So I know it can be done. I am hoping that someone with industry specific knowledge in this area can guide me in getting this number.

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  • 2-D Lighting Theory

    - by Richard
    I am writing a rogue-like 'zombie' management game. The game map will be similar to Prison Architect. A top-down 50 X 50 grid. I want to implemented a day night cycle and during the night I would like the player to be able to position lights. I would like to be able to lighten and dark to whole map to display the day and night cycle. Then lights would be a circle of light blocked by game entities such as walls, players, trees etc. How would I achieve and what is the standard way of achieving this?

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  • Finding a prime number after a given number

    - by avd
    How can I find the least prime number greater than a given number? For example, given 4, I need 5; given 7, I need 11. I would like to know some ideas on best algorithms to do this. One method that I thought of was generate primes numbers through the Sieve of Eratosthenes, and then find the prime after the given number.

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  • Computationally simple Pseudo-Gaussian Distribution with varying mean and standard deviation?

    - by mstksg
    This picture from wikipedia has a nice example of the sort of functions I'd ideally like to generate http://en.wikipedia.org/wiki/File:Normal_Distribution_PDF.svg Right now I'm using the Irwin-Hall Distribution, which is more or less a Polynomial approximation of the Gaussian distribution...basically, you use uniform random number generator and iterate it x times, and take the average. The more iterations, the more like a Gaussian Distribution it is. It's pretty nice; however I'd like to be able to have one where I can vary the mean. For example, let's say I wanted a number between the range 0 and 10, but around 7. Like, the mean (if I repeated this function multiple times) would turn out to be 7, but the actual range is 0-10. Is there one I should look up, or should I work on doing some fancy maths with standard Gaussian Distributions?

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