• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.293-296
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• 1998

In this paper, we propose a matrix hypercube graph as a new topology for parallel computer and analyze its characteristics of the network parameters, such as degree, routing and diameter. N-dimensional matrix hypercube graph MH(2,n) contains 22n vertices and has relatively lower degree and smaller diameter than well-known hypercube graph. The matrix hypercube graph MH(2,n) and the hypercube graph Q2n have the same number of vertices. In terms of the network cost, defined as the product of the degree and diameter, the former has n2 while the latter has 4n2. In other words, it means that matrix hypercube graph MH(2,n) is better than hypercube graph Q2n with respect to the network cost.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.92-98
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• 1994

The hypercube-like interconncetion network,X-hypercubes,has the same number of nodes and edges as conventional hypercubes.By slightly changing the interconneton way between nodes,however,X-hypercubes reduces the diameter by almost half.Thus the communication delay in X-hypercubes can be expected to be much lower than that in hypercubes. This paper gives a new definition of X-hypercubes establishing clear-cut condition of connection between two nodes.As appliction examples of the new definition,this paper presents simple embeddings of hypercubes in X-hypercubes and vice versa.This means that any programs written for hypercubes can be transported onto X-hypercubes and vice versa with minimal overhead.This paper also present bitonic merge sort for X-hypercubes by simulation that for hypercubes.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.637-640
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• 2000

본 논문에서는 하이퍼큐브보다 망비용이 개선된 HFN(n,n)과 2n-hypercube 사이의 임베딩을 분석한다. 2n-hypercube를 HFN(n,n)에 연장율 3에 임베딩 가능함을 보이고, HFN(n,n)을 2n-hypercube에 임베딩하는 비용이 O(n)임을 보인다.

• Journal of the Korean Statistical Society
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• v.28 no.2
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• pp.135-150
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• 1999

Latin hypercube sampling(LHS) introduced by McKay et al. (1979) is a widely used method for Monte Carlo integration. Stratified Latin hypercube sampling(SLHS) proposed by Choi and Lee(1993) improves LHS by combining it with stratified sampling. In this article it is shown that SLHS yields an asymptotically more accurate than both stratified sampling and LHS.

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.89-95
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• 2006

This paper proposes a modified method of Latin Hypercube sampling to reduce the variance of statistical parameters in uncertainty analysis of concrete structures. The proposed method is a modification of Latin Hypercube sampling method. This analysis method uses specifically modified tables of random permutations of ranked numbers. In addition, the Spearman coefficient is used to make modified tables. Numerical analysis is carried out to predict the uncertainty of axial shortening in prestressed concrete bridge. Statistical parameters obtained from modified Latin Hypercube sampling method and conventional Latin Hypercube sampling method are compared and evaluated by a numeric analysis. The results show that the proposed method results in a decrease in the variance of statistical parameters. This indicates the method is efficient and effective in the uncertainty analysis of complex structural system such as prestressed concrete bridges.

• The Korean Journal of Applied Statistics
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• v.8 no.2
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• pp.99-108
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• 1995

When modeling a complicated system with a computer model, it is of vital importance to choos input values efficiently. The Latin Hypercube sampling (LHS) proposed by MaKay et al.(1979) has been most widely used for choosing input values for a computer model. We propose the two-stage Latin Hypercube sampling(TLHS) which is an improved version of the LHS for procucing input values in estimating the excectation of a function of the output variable. The proposed method is applied to simulation study of the performance of a printer actuator and it is shown to outperform the other sampling methods including the LHS in accuracy.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.242-250
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• 1996

Communications on hypercube nodes are done by explicit message routing. So efficient message routing is very important for the performance of hypercube multicomputers. However, hypercube nodes can be faulty due to hardware and/o r software problems, which is called an injured hypercube. A reliable hypercube system should tolerate the problems. One of the methods to enhance reliability on injured hypercube is to use fault-tolerant message routing algorithms. In this paper, we propose a message routing algorithm with possible shortest distance using disjoint paths. To analyze the performance, the algorithm is simulated and evaluated.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.1-9
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• 1993

In this paper, we develop enhanced hypercube architectures and routing algorithms to realize arbitrary permutations in circuit switching. We prove that a hypercube is rearrangeable if one additional pair of links (one full-duplex communication line) is provided in only one dimesion of connections. We also prove that if each connection between two neighboring nodes consists of two pairs of links, the hypercube can handle two independent permutations simultaneously.

• ETRI Journal
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• v.30 no.3
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• pp.483-485
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• 2008

A micro-sensor network is comprised of a large number of small sensors with limited memory capacity. Current key-establishment schemes for symmetric encryption require too much memory for micro-sensor networks on a large scale. In this paper, we propose a memory-efficient hypercube key establishment scheme that only requires logarithmic memory overhead.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.7
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• pp.952-965
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• 1995

In the hypercube multiprocessor system. repeated allocations and deallocations of subcubes generate a fragmented hypercube from which. even if sufficient free processors are available, a subcube that is large enough to accomodate a new task cannot be formed. To eliminate the fragmentation, we need a processor relocation to move a task-occupied subcube to a free subcube, and gather dispersed small subcubes. In this paper, we propose a routing algorithm for task migration in circuit- switched hypercube to relocate processors. In the circuit-switched hypercube, we have to find a set of dedicated link-disjoint routing paths for each node to move a task from a busy subcube to a free subcube in fragmentation. The proposed algorithm is based on the PGC(packed Gray code) which detects all kinds of subcubes.