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Search found 252 results on 11 pages for 'dimensionality reduction'.

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  • segmented reduction with scattered segments

    - by Christian Rau
    I got to solve a pretty standard problem on the GPU, but I'm quite new to practical GPGPU, so I'm looking for ideas to approach this problem. I have many points in 3-space which are assigned to a very small number of groups (each point belongs to one group), specifically 15 in this case (doesn't ever change). Now I want to compute the mean and covariance matrix of all the groups. So on the CPU it's roughly the same as: for each point p { mean[p.group] += p.pos; covariance[p.group] += p.pos * p.pos; ++count[p.group]; } for each group g { mean[g] /= count[g]; covariance[g] = covariance[g]/count[g] - mean[g]*mean[g]; } Since the number of groups is extremely small, the last step can be done on the CPU (I need those values on the CPU, anyway). The first step is actually just a segmented reduction, but with the segments scattered around. So the first idea I came up with, was to first sort the points by their groups. I thought about a simple bucket sort using atomic_inc to compute bucket sizes and per-point relocation indices (got a better idea for sorting?, atomics may not be the best idea). After that they're sorted by groups and I could possibly come up with an adaption of the segmented scan algorithms presented here. But in this special case, I got a very large amount of data per point (9-10 floats, maybe even doubles if the need arises), so the standard algorithms using a shared memory element per thread and a thread per point might make problems regarding per-multiprocessor resources as shared memory or registers (Ok, much more on compute capability 1.x than 2.x, but still). Due to the very small and constant number of groups I thought there might be better approaches. Maybe there are already existing ideas suited for these specific properties of such a standard problem. Or maybe my general approach isn't that bad and you got ideas for improving the individual steps, like a good sorting algorithm suited for a very small number of keys or some segmented reduction algorithm minimizing shared memory/register usage. I'm looking for general approaches and don't want to use external libraries. FWIW I'm using OpenCL, but it shouldn't really matter as the general concepts of GPU computing don't really differ over the major frameworks.

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  • Lookup table size reduction

    - by Ryan
    Hello: I have an application in which I have to store a couple of millions of integers, I have to store them in a Look up table, obviously I cannot store such amount of data in memory and in my requirements I am very limited I have to store the data in an embebedded system so I am very limited in the space, so I would like to ask you about recommended methods that I can use for the reduction of the look up table. I cannot use function approximation such as neural networks, the values needs to be in a table. The range of the integers is not known at the moment. When I say integers I mean a 32 bit value. Basically the idea is use some copmpression method to reduce the amount of memory but without losing many precision. This thing needs to run in hardware so the computation overhead cannot be very high. In my algorithm I have to access to one value of the table do some operations with it and after update the value. In the end what I should have is a function which I pass an index to it and then I get a value, and after I have to use another function to write a value in the table. I found one called tile coding http://www.cs.ualberta.ca/~sutton/book/8/node6.html, this one is based on several look up tables, does anyone know any other method?. Thanks.

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  • Windows 8 : réduction de la consommation d'énergie de façon cohérente et standardisée pour toutes les plateformes

    Windows 8 : réduction de la consommation d'énergie de façon cohérente et standardisée pour toutes les plateformes Mise à jour du 10/11/11 L'autonomie de la batterie et la consommation en énergie sont des sujets importants dans l'industrie informatique. Microsoft revient aujourd'hui sur les travaux qui ont été effectués dans Windows 8 pour améliorer la gestion de l'énergie. Construite de façon cohérente et standardisée pour toutes les plateformes (PC, Tablettes, etc.), la gestion d'énergie avec Windows 8 offre une plus grande autonomie de la batterie, avec une réduction significative de la consommation d'énergie. ...

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  • Sequence reduction in R

    - by drknexus
    Assume you have a vector like so: v <- c(1,1,1,2,2,2,2,1,1,3,3,3,3) How can it be best reduced to a data.frame like this? v.df <- data.frame(value=c(1,2,1,3),repetitions=c(3,4,2,4)) In a procedural language I might just iterate through a loop and build the data.frame as I go, but with a large dataset in R such an approach is inefficient. Any advice?

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  • Simple reduction (NP completeness)

    - by Allen
    hey guys I'm looking for a means to prove that the bicriteria shortest path problem is np complete. That is, given a graph with lengths and weights, I need to know if a there exists a path in the graph from s to t with total length <= L and weight <= W. I know that i must take an NP complete problem and reduce it to this one. We have at our disposal the following problems to choose from: 3-SAT, independent set, vertex cover, hamiltonian cycle, and 3-dimensional matching. Any ideas on which may be viable? thanks

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  • Google Cloud Platform : nouvelles fonctionnalités, augmentation des capacités des centres de données et réduction des prix

    Google Cloud Platform : nouvelles fonctionnalités réduction des prix et augmentation des capacités des centres de données en Europe Google a apporté une mise à jour importante à son offre Google Cloud Platform. Google Cloud Platform est une suite de solution Cloud computing (SaaS et IaaS) pour les développeurs, les entreprises et biens plus. L'offre comprend les plateformes : App Engine, Cloud Storage, BigQuery, Compute Engine, Cloud SQL, etc. Compute Engine, l'offre IaaS (Infrastructure as a Service) de l'éditeur dévoilée en juin dernier avec quatre types d'instances, s'enrichit de 36 nouveaux types d'instances, avec à la clé une réduction générale des prix. De...

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  • Salt River Project Identifies US$500,000 in Cost Reduction Opportunities Through Unified IT Portfolio Management

    - by Melissa Centurio Lopes
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Salt River Project (SRP) includes two entities serving the Phoenix area: the Salt River Project Agricultural Improvement and Power District and the Salt River Valley Water Users’ Association. The SRP district operates various power plants and generating stations to provide electricity to nearly 956,000 retail customers. The SRP association maintains an extensive system of reservoirs, wells, and irrigation laterals to deliver nearly 1 million acre-feet of water annually. Salt River Project implemented Oracle’s Primavera Portfolio Management to unify management of its extensive IT portfolio, including essential utility systems, like work and asset management, as well as programming frameworks and development tools. With the system, SRP discovered almost US$500,000 in cost-reduction opportunities by identifying redundant or low use software, including 150 applications that are close to being unsupported. The company retired 10 applications in the last year and upgraded 34 systems. SRP also identified preferred technologies and ensured that more than 90% of applications are based on standard technologies—reducing procurement costs, simplifying maintenance support, and lowering total cost of ownership. Solutions: Provided approximately 70 users in the IT support group with detailed insight into the product lifecycle of each piece of IT infrastructure and software in the entire portfolio Discovered almost US$500,000 in cost reduction opportunities by identifying redundant or low use software that could be eliminated or migrated to alternative solutions Identified approximately 150 applications that are close to being unsupported and prioritized them to begin modernization Click here to view more Oracle Primavera Portfolio Management solutions for SRP. Why Oracle Salt River Project chose Oracle’s Primavera Portfolio Management after evaluating it against four other solutions. “Oracle’s Primavera Portfolio Management offered the most functionality to support our diverse needs,” said Eileen Ahles, IT portfolio manager, Salt River Project. Read the complete customer success story Access a list of all Primavera customer success stories

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  • Windows 8 : réduction des redémarrages automatiques pour le service Windows Update

    Windows 8 : réduction des redémarrages automatiques après les mises à jour Mise à jour du 15/11/11 Windows 8 apportera une révision majeure du service Windows Update qui sera désormais moins intrusif, avec des redémarrages centralisés. Microsoft, sur le blog consacré à l'OS, présente les améliorations apportées au service Windows Update utilisé pour mettre à jour plus de 350 millions de PC sous Windows 7 et plus de 800 millions de dispositifs Windows en général, selon la firme. Avec Windows 8, les redémarrages pour les mises à jour seront effectués une seule fois au début de chaque mois, après la publication du Patch Tuesday qui survient le...

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  • Dimension Reduction in Categorical Data with missing values

    - by user227290
    I have a regression model in which the dependent variable is continuous but ninety percent of the independent variables are categorical(both ordered and unordered) and around thirty percent of the records have missing values(to make matters worse they are missing randomly without any pattern, that is, more that forty five percent of the data hava at least one missing value). There is no a priori theory to choose the specification of the model so one of the key tasks is dimension reduction before running the regression. While I am aware of several methods for dimension reduction for continuous variables I am not aware of a similar statical literature for categorical data (except, perhaps, as a part of correspondence analysis which is basically a variation of principal component analysis on frequency table). Let me also add that the dataset is of moderate size 500000 observations with 200 variables. I have two questions. Is there a good statistical reference out there for dimension reduction for categorical data along with robust imputation (I think the first issue is imputation and then dimension reduction)? This is linked to implementation of above problem. I have used R extensively earlier and tend to use transcan and impute function heavily for continuous variables and use a variation of tree method to impute categorical values. I have a working knowledge of Python so if something is nice out there for this purpose then I will use it. Any implementation pointers in python or R will be of great help. Thank you.

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  • How to find out the dimensionality of print paper in javascript

    - by tzador
    I am generating reports in HTML formats, and want to print them automatically using Qt (qt has a webkit based browser, and one can render its contents to a PDF file). I want to position the elements of the report depending on the target page size. For that i need to access the size of the paper (preferably in pixels). Since i am using webkit, it has all the latest html5 and css3 features. is there some api available to access printed page properties inside javascript. for example, would be nice to write: window.print_paper.width or window.print_paper.height Thank you in advance

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  • About curse of dimensionality

    - by Dan
    My question is about this topic I've been reading about a bit. Basically my understanding is that in higher dimensions all points end up being very close to each other. The doubt I have is whether this means that calculating distances the usual way (euclidean for instance) is valid or not. If it were still valid, this would mean that when comparing vectors in high dimensions, the two most similar wouldn't differ much from a third one even when this third one could be completely unrelated. Is this correct? Then in this case, how would you be able to tell whether you have a match or not?

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  • resize image without image quality reduction

    - by ali
    In web design , it's usually needed to design an image for example in Photoshop and then use multiple sizes of it. but I don't understand something here : When I resize the image (PNG or JPG) and reduce the dimensions of that in Photoshop , the image quality extremely gets reduced and the edges become messy while resizing the image in a simple software like Microsoft Paint gives a really better output! So what's the reason ? Is there a trick in Photoshop for image resizing which I've missed? Thanks for your help. UPDATE: I resize in this way : image image size , then enter new dimensions , all of checkboxes are checked , and have tried all of resample modes including Bicubic sharper

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  • Persian font in Netbeans cause speed reduction

    - by linker
    I have speed problem in Netbeans 7.0 IDE when my current open document has any Persian font inside it. If it happens, the speed of software incredibly reduce.( for example if I hit backspace, it takes about 10 seconds to respond). The amazing part is when I open a fully english document in Netbeans there is no problem and everything works well. I'm running netbeans 7.0 on Mac OS X 10.7.2. This problem happens with every fonts( even with fully Persian fonts). But I really want to have Persian with default Monospaced font. Thanks in advance.

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  • Sondage : les bureaux virtuels séduisent de plus en plus les PME pour leur flexibilité et la réduction des coûts qu'ils permettent

    Sondage : les bureaux virtuels séduisent de plus en plus les PME En tête des motivations, flexibilité et réduction des coûts Virtual PBX, fournisseur de solutions virtuelles, vient de publier les résultats d'un sondage sur l'utilisation des bureaux virtuels, désormais au coeur de la politique IT de nombreuses PME. En tête des raisons évoquées par les PDG, propriétaires, partenaires et directeurs de ventes interrogés, arrive le souci de flexibilité (61 %) suivi de près par la « réduction des coûts » avec 54 %. Parmi ces décideurs, 43 % d'entre eux affirment économiser 1.000 dollars ou plus chaque mois sur la location, les équipements IT, la téléphonie et les fournitu...

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  • Linux 3.12 disponible en version stable, avec des gains de performances et une réduction de la consommation d'énergie

    Linux 3.12 disponible en version stable avec des gains de performances et une réduction de la consommation d'énergieLinux Torvalds a annoncé via un message sur LKLM (Linux Kernel Mailing List) la sortie de la version stable du noyau Linux 3.12.Au menu des améliorations, un changement dans la façon de gérer la fréquence de fonctionnement du processeur de l'ordinateur (modification de l'algorithme CPUfreq governor) permettant des gains significatifs de performances et une réduction de la consommation...

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  • TicTacToe strategic reduction

    - by NickLarsen
    I decided to write a small program that solves TicTacToe in order to try out the effect of some pruning techniques on a trivial game. The full game tree using minimax to solve it only ends up with 549,946 possible games. With alpha-beta pruning, the number of states required to evaluate was reduced to 18,297. Then I applied a transposition table that brings the number down to 2,592. Now I want to see how low that number can go. The next enhancement I want to apply is a strategic reduction. The basic idea is to combine states that have equivalent strategic value. For instance, on the first move, if X plays first, there is nothing strategically different (assuming your opponent plays optimally) about choosing one corner instead of another. In the same situation, the same is true of the center of the walls of the board, and the center is also significant. By reducing to significant states only, you end up with only 3 states for evaluation on the first move instead of 9. This technique should be very useful since it prunes states near the top of the game tree. This idea came from the GameShrink method created by a group at CMU, only I am trying to avoid writing the general form, and just doing what is needed to apply the technique to TicTacToe. In order to achieve this, I modified my hash function (for the transposition table) to enumerate all strategically equivalent positions (using rotation and flipping functions), and to only return the lowest of the values for each board. Unfortunately now my program thinks X can force a win in 5 moves from an empty board when going first. After a long debugging session, it became apparent to me the program was always returning the move for the lowest strategically significant move (I store the last move in the transposition table as part of my state). Is there a better way I can go about adding this feature, or a simple method for determining the correct move applicable to the current situation with what I have already done?

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  • Modular Reduction of Polynomials in NTRUEncrypt

    - by Neville
    Hello everyone. I'm implementing the NTRUEncrypt algorithm, according to an NTRU tutorial, a polynomial f has an inverse g such that f*g=1 mod x, basically the polynomial multiplied by its inverse reduced modulo x gives 1. I get the concept but in an example they provide, a polynomial f = -1 + X + X^2 - X4 + X6 + X9 - X10 which we will represent as the array [-1,1,1,0,-1,0,1,0,0,1,-1] has an inverse g of [1,2,0,2,2,1,0,2,1,2,0], so that when we multiply them and reduce the result modulo 3 we get 1, however when I use the NTRU algorithm for multiplying and reducing them I get -2. Here is my algorithm for multiplying them written in Java: public static int[] PolMulFun(int a[],int b[],int c[],int N,int M) { for(int k=N-1;k>=0;k--) { c[k]=0; int j=k+1; for(int i=N-1;i>=0;i--) { if(j==N) { j=0; } if(a[i]!=0 && b[j]!=0) { c[k]=(c[k]+(a[i]*b[j]))%M; } j=j+1; } } return c; } It basicall taken in polynomial a and multiplies it b, resturns teh result in c, N specifies the degree of the polynomials+1, in teh example above N=11; and M is the reuction modulo, in teh exampel above 3. Why am I getting -2 and not 1?

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  • Java multiple class compositing and boiler plate reduction

    - by h2g2java
    We all know why Java does/should not have multiple inheritance. So this is not questioning about what has already been debated till-cows-come-home. This discusses what we would do when we wish to create a class that has the characteristics of two or more other classes. Probably, most of us would do this to "inherit" from three classes. For simplicity, I left out the constructor.: class Car extends Vehicle { final public Transport transport; final public Machine machine; } So that, Car class directly inherits methods and objects of Vehicle class, but would have to refer to transport and machine explicitly to refer to objects instantiated in Transport and Machine. Car car = new Car(); car.drive(); // from Vehicle car.transport.isAmphibious(); // from Transport car.machine.getCO2Footprint(); // from Machine I thought this was a good idea until when I encounter frameworks that require setter and getter methods. For example, the XML <Car amphibious='false' footPrint='1000' model='Fordstatic999'/> would look for the methods setAmphibious(..), setFootPrint(..) and setModel(..). Therefore, I have to project the methods from Transport and Machine classes class Car extends Vehicle { final public Transport transport; final public Machine machine; public void setAmphibious(boolean b){ this.transport.setAmphibious(b); } public void setFootPrint(String fp){ this.machine.setFootPrint(fp); } } This is OK, if there were just a few characteristics. Right now, I am trying to adapt all of SmartGWT into GWT UIBinder, especially those classes that are not a GWT widget. There are lots of characteristics to project. Wouldn't it be nice if there exists some form of annotation framework that is like this: class Car extends Vehicle @projects {Transport @projects{Machine @projects Guzzler}} { /* No need to explicitly instantiate Transport, Machine or Guzzler */ .... } Where, in case of common names of characteristics exist, the characteristics of Machine would take precedence Guzzler's, and Transport's would have precedence over Machine's, and Vehicle's would have precedence over Transport's. The annotation framework would then instantiate Transport, Machine and Guzzler as hidden members of Car and expand to break-out the protected/public characteristics, in the precedence dictated by the @project annotation sequence, into actual source code or into byte-code. Preferably into byte-code. So that the setFootPrint method is found in both Machine and Guzzler, only that of Machine's would be projected. Questions: Don't you think this is a good idea to have such a framework? Does such a framework already exist? Tell me where/what. Is there an eclipse plugin that does it? Is there a proposal or plan anywhere that you know about such an annotation framework? It would be wonderful too, if the annotation/plugin framework lets me specify that boolean, int, or whatever else needs to be converted from String and does the conversion/parsing for me too. Please advise, somebody. I hope wording of my question was clear enough. Thx. Edited: To avoid OO enthusiasts jumping to conclusion, I have renamed the title of this question.

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  • Reusability, testability, code complexity reduction and showing-off-ability programming importance

    - by Andrew Florko
    There are lots of programming and architecture patterns. Patterns allow to make code cleaner, reusable, more testable & at last (but not at least) to feel the follower a real cool developer. How do you rank these considerations for you? What does affect you most when you decide to apply pattern? I wonder how many times code reusability (especially for MVP, MVC patterns) was important? For example DAL library often shared between projects (it's reusable) but how often controllers/views (abstracted via interfaces) are reused?

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  • C#, MEF - Sign trusted plugins for abuse reduction

    - by Marks
    Hi there. I have a program that is extendable by plugins using the Microsoft Extensibility Framework. But i dont want untrusted sources to give out plugins that may be insecure. So i want to sign the plugins (maybe with Visual Studio's built in signing) and check if the plugins are trustworthy at program start. I didn't find a way to check DLL signing from inside C#. And also there is the problem, that I load the plugins with a DirectoryCatalog. There is no way to tell, which plugin is from which file. Anyone knows a way to do this? Thanks for any help, Marks

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  • Iterative Reduction to Null Matrix

    - by user1459032
    Here's the problem: I'm given a matrix like Input: 1 1 1 1 1 1 1 1 1 At each step, I need to find a "second" matrix of 1's and 0's with no two 1's on the same row or column. Then, I'll subtract the second matrix from the original matrix. I will repeat the process until I get a matrix with all 0's. Furthermore, I need to take the least possible number of steps. I need to print all the "second" matrices in O(n) time. In the above example I can get to the null matrix in 3 steps by subtracting these three matrices in order: Expected output: 1 0 0 0 1 0 0 0 1 0 0 1 1 0 0 0 1 0 0 1 0 0 0 1 1 0 0 I have coded an attempt, in which I am finding the first maximum value and creating the second matrices based on the index of that value. But for the above input I am getting 4 output matrices, which is wrong: My output: 1 0 0 0 1 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 My solution works for most of the test cases but fails for the one given above. Can someone give me some pointers on how to proceed, or find an algorithm that guarantees optimality? Test case that works: Input: 0 2 1 0 0 0 3 0 0 Output 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0

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  • Haskell "Source reduction"

    - by Martin
    I'm revising for an upcoming Haskell exam and I don't understand one of the questions on a past paper. Google turns up nothing useful fst(x, y) = x square i = i * i i) Source reduce, using Haskells lazy evaluation, the expression: fst(square(3+4), square 8) ii) Source reduce, using strict evaluation, the same expression iii) State one advantage of lazy evaluation and one advantage of strict evaluation

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