• 한국정보처리학회논문지
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• 제6권5호
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• pp.1219-1224
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• 1999

This paper derived Montgomery's parallel algorithms for modular multiplication based on Walter's and Iwamura's method, and compared data dependence graph of each parallel algorithm. Comparing the result, Walter's parallel algorithm has small computational index in data dependence graph, so it is selected and used to computed spatial and temporal pipelining diagrams with each projection direction for designing expansible bit-level systolic array. We also evaluated internal operation of proposed expansible systolic array C++ language.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4347-4366
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• 2015

Distinguished with traditional strategies which offload an application's computation to a single server, parallel computation offloading can promote the performance by simultaneously delivering the computation to multiple computing resources around the mobile terminal. However, due to the variability of communication and computation environments, static application component multi-partitioning algorithms are difficult to maintain the optimality of their solutions in time-varying scenarios, whereas, over-frequent algorithm executions triggered by changes of environments may bring excessive algorithm costs. To this end, an adaptive application component mapping algorithm for parallel computation offloading in variable environments is proposed in this paper, which aims at minimizing computation costs and inter-resource communication costs. It can provide the terminal a suitable solution for the current environment with a low incremental algorithm cost. We represent the application component multi-partitioning problem as a graph mapping model, then convert it into a pathfinding problem. A genetic algorithm enhanced by an elite-based immigrants mechanism is designed to obtain the solution adaptively, which can dynamically adjust the precision of the solution and boost the searching speed as transmission and processing speeds change. Simulation results demonstrate that our algorithm can promote the performance efficiently, and it is superior to the traditional approaches under variable environments to a large extent.

• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.61-70
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• 2023

Image segmentation is a very crucial step in effective digital image processing. In the past decade, several research contributions were given related to this field. However, a general segmentation algorithm suitable for various applications is still challenging. Among several image segmentation approaches, graph-based approach has gained popularity due to its basic ability which reflects global image properties. This paper proposes a methodology to partition the image with its pixel, region and texture along with its intensity. To make segmentation faster in large images, it is processed in parallel among several CPUs. A way to achieve this is to split images into tiles that are independently processed. However, regions overlapping the tile border are split or lost when the minimum size requirements of the segmentation algorithm are not met. Here the contributions are made to segment the image on the basis of its pixel using min-cut/max-flow algorithm along with edge-based segmentation of the image. To segment on the basis of the region using a homogenous optimum cut algorithm with boundary segmentation. On the basis of texture, the object type using spectral partitioning technique is identified which also minimizes the graph cut value.

• 대한산업공학회지
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• 제24권4호
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• pp.591-600
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• 1998

The scheduling of parallel computing systems consists of two procedures, the assignment of tasks to each available processor and the ordering of tasks in each processor. The assignment procedure is same with a clustering. The clustering is classified into linear or nonlinear according to the precedence relationship of the tasks in each cluster. The parallel computing system can be modeled with a Directed Acyclic Graph(DAG). By the granularity theory, DAG is categorized into Coarse Grain Type(CDAG) and Fine Grain Type(FDAG). We suggest the linear clustering method for the scheduling of CDAG using the genetic algorithm. The method utilizes a properly that the optimal schedule of a CDAG is one of linear clustering. We present the computational comparisons between the suggested method for CDAG and an existing method for the general DAG including CDAG and FDAG.

• 대한전자공학회논문지
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• 제24권2호
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• pp.355-361
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• 1987

The shuffle-exchange graph is known as a structure to perform the parallel algorithms like Discrete Fourier Transform(DFT), matrix multiplication and sorting. In this paper, the layout for the shuffle-exchange graph is described and this layout places emphasis on the placement of nodes that has the capability to have as small area as possible, have as a small number of crossings as possible, and have as short wires as possible. The algorithm corrdsponding these conditions is proposed and each evaluation factor and the placement of the N-node shuffle-exchange graph is performed with FORTRAN and BASIC program, and these results are calcualted.

• 대한전자공학회논문지
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• 제21권6호
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• pp.56-63
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• 1984

본 논문에서는 GRAFCET로 기술된 병렬 sequence를 갖는 순서 논리 시스템을 Programmed logic에 의해 실현하는 방법을 제안한다 이를 위해 먼저 병렬 sequence를 갖는 GRAFCET를 그 본래의 물리적 의미를 변형치 않고 다수의 state graph로 재구성하는 알고리즘을 제안했으며 이 제안된 알고리즘은 모든 형태의 GRAFCET에 적용 가능하며 특히 sub-system으로의 분해 및 그 역과정을 손쉽게 한다. 다음 이와같이 재구성된 state graph를 ROM을 사용한 microproerammed logic에 의해 구성하는 조직적인 방법을 제시했으며 이 제시된 구성 방법은 선택 sequence의 수를 임의로 확장할 수 있다.

• 정보처리학회논문지A
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• 제11A권5호
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• pp.341-346
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• 2004

최근에 병렬처리를 위한 새로운 위상으로 하이퍼-스타 그래프 HS(m, k)가 제안되었다. 하이퍼-스타 그래프는 하이퍼큐브와 스타 그래프의 성질을 가지고 있으면서, 같은 노드수를 갖는 하이퍼큐브 보다 망비용이 우수한 그래프이다 본 논문에서는 하이퍼-스타 그래프 HS(m, k)가 하이퍼큐브의 서브그래프임을 증명한다. 그리고 정규형 그래프인 하이퍼-스타 HS(2n, n)가 제안된 매핑 기법에 의해 노드 대칭임을 보이며, 최소 높이를 갖는 스패닝 트리를 이용한 일-대-다 방송 기법을 제안하고, 방송 수행 시간이 2n-1임을 보인다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.773-775
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• 2013

본 논문에서는 재구성가능한 메쉬에서 유향 사이클 그래프의 각 정점별 이웃 정보만 가지고 유향 사이클을 구성하는 정점들의 순서를 찾는 문제를 고려한다. 이 문제는 순차 알고리즘으로는 선형 시간에 해결되는 문제이지만 선형 시간보다 낮은 차수의 병렬 알고리즘을 고안하는 것은 어려운 문제이다. 모든 종류의 다각형은 유향 사이클 그래프에 해당하므로, 이 문제에 대한 해는 다각형의 정점별 이웃 정보로부터 다각형을 구성해야 하는 문제의 해결에 활용될 수 있다. 본 논문에서는 정점의 수가 n인 유향 사이클 그래프의 정점 순서를 구하는 문제를 $n{\times}n^2$ 크기의 재구성가능한 메쉬에서 상수 시간에 해결하는 병렬 알고리즘을 제시한다.

• 대한산업공학회지
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• 제1권2호
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• pp.51-56
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• 1975

A computer program for computing complex system reliability is described. The program is composed of three phases : Phase I program reduces all series, parallel and series-parallel components and subsequently obtains an irreducible non-series-parallel system. Phase II program enumerates all the possible paths from the source to the sink of the graph. Phase III program then computes system reliability based on the information obtained by the Phase II program. The program is based on a modified version of the algorithm published in [6]. An example of the use of the computer program is given.

• 한국전자통신학회논문지
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• 제5권5호
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• pp.444-448
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• 2010

RCR 네트워크 토폴로지[1]는 짧은 지름, 대칭성 등의 특징을 가지고 있어 병렬컴퓨팅 환경을 구성하기에 적합한 상호접속네트워크의 일종이다. Hu and Cao[2]에 의하여 이 토폴로지 분석에 대한 재검토가 이루어졌으며, 그래프 비연결성, 직경, bisection width 등에 대한 오류가 있음을 지적하였다. 이 논문에서는 RCR 네트워크 토폴로지 특성을 분석하고, [2]의 결과에도 여전히 남아있는 '연결그래프가 되기 위한 조건' 및 직경에 대한 오류를 정정한다. 그리고 RCR 네트워크에서 최단경로를 구하기 위한 알고리즘을 제안한다.