24.07.2013
Live Pixels
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Annotation: How rules our life? “Live Pixels” show how from a usual exercise book in a cage and and a simple logical rule comes a complicated world , which has interesting similarities with the reality. Here you'll see the Big Bang universe, the law of transformation of quantity into quality, reproduction with the conservation of genetic information, the evolution of species, and much more. The free program will acquaint you with ready examples and suggest taking to create their own in a convenient editor. "Living Pixels" - is a mathematical abstraction, cellular automata, similar to Conway’s “The Game of Life”.
Keywords: live pixels; neoneuro, cellular automata, game of life |
04.04.2013
Using decomposition for vehical routing problem with time windows
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Annotation: A method is proposed to reduce the size of capacitated VRP with time windows.
Keywords: clusterisation, vehical routing problem, VRP; |
15.04.2013
An iterative imitational method of solving capacitated travel salesman problem with time windows regarding dynamic traffic.
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Annotation: Annotation of my article.
Keywords: semicolon separated keywords list; |
Графика
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17.02.2012
Voxel rasterization and processing technique
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Annotation: One can’t solve present tasks in various domains without computer modeling. Usually, 3D graphics is used for data processing and presentation in computer modeling. Modeling results depends on used model types and development technologies. Triangulated models are primary used in modern computer 3D graphics. However, voxel models are more efficient in complex data processing. Using of voxel models is limited by computer capabilities at practice. But today it becomes possible to work with voxel models because of general-purpose computing on graphics processing units (GPGPU). As a result international attention is turning to voxels. A lot of voxel graphics techniques are developed at present, such as marching cubes, volume ray casting, texturing of volume slices and etc. However, it is necessary to improve existing techniques according to task domain for practical task solution. In the paper real-time voxel rasterization and processing technique for mining industry is described, that based on ray-marching pixel shader approach. It can be successfully used for solution of wide range tasks. In the paper general technique description allows to choose that implementation, that’s more efficient for practical task solution. Today a lot of software solutions run under Windows operating systems. So task context usually depends on these systems. Today .Net Framework and DirectX are more efficient development technologies on Windows. For these reasons C# and HLSL are used for technique implementation.
Keywords: computer modeling; 3D graphics; voxels; volume ray casting; shader; programmable graphics pipeline; rasterization; voxel processing; .Net Framework; C#; DirectX; Direct3D; DirectCompute; HLSL; GPGPU; SlimDX |
Кодирование
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23.08.2010
The Gray code
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Annotation: Description of the Gray code and alghorithms above it, from initial task to calculate gray-encoded numerics sum.
Keywords: Gray code; |
22.09.2011
Constructor of PPM codecs
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Annotation: The paper proposes the implementation of a family of PPM compressors as a customizable set of C++ templates. It's possible to construct PPM codecs using these templates that can support context model orders from the 1st to the 10th inclusive with or without memory restriction. The various known methods of escape code calculation are analyzed in this paper including a new original method proposed by the author. This family of PPM compressors supports the different methods of compression improvement such as LOE, symbols exclusion, extra weighting during initialization and others. The possibility to include any other additional methods to improve the compression is also described.
Keywords: lossless compression; codec; Prediction by Partial Matching; PPM; escape code; PPMtc; finite context modeling;C++; |
29.12.2011
Partial PPM codecs
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Annotation: This paper considers the PPM codecs, which have omissions in the context orders. Since the context model of these codecs contains gaps, they can be named as "partial", as opposed to "full" PPM codecs, which have all the context orders up to a fixed maximum order. The article compares these two types of codecs and is trying to answer the questions: is it possible to improve compression, reduce memory usage and speed up compression/decompression processes using partial PPM codecs.
Keywords: lossless compression; codec; Prediction by Partial Matching; PPM; PPMtc; C++; |
Конечные автоматы
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Математика
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04.07.2011
Random generation of combinations. Generation of combination from its sequence number
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Annotation: The article is devoted to methods of generating random combinations. We analyze two such methods - generating a combination from randomly generated permutation and generating a combination from its sequence number. The library of C++ functions implementing the methods described is provided. The performance of the developed methods is compared. Also an interesting consequence of generating a combination from number is viewed - compact storage of sequences of elements.
Keywords: combinatorics; combination; combinations’ generation; random combination; sequence number of combination; binomial coefficient; permutation; algorithm; |
08.07.2011
The problem of tolerance to errors in floating point
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Annotation: The problem of calculation errors with real numbers. The article gives some examples of the sensitive to errors in the code and look for ways to address them. The urgency of this problem for those involved in the creation of programs performing mathematical calculations.
Keywords: error in computation; real numbers; FPU; stability of the algorithm |
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20.02.2012
Abstract data types in programming
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Annotation: The article discusses various aspects of abstract data types (ADT) in programming. Awareness of the concept of ADT in the mid 70s of last century led to a number of papers on the theory of programming. The concept of abstract data types at the moment is one of the most popular abstraction mechanism used by developers to write software. The paper deals with the basics of the mathematical theory that describes the abstract data types as algebraic systems. On the basis of ADT’s signatures are constructed so-called initial algebra – the syntactic representation of an ADT entities. An initial algebra can be used to verify the correctness of the code.
Keywords: abstract data types; ADT; algebraic specifications; programming theory |
