• Journal of Communications and Networks
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• 제14권2호
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• pp.213-221
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• 2012

The architecture of an interconnection network is usually represented by a graph, and a graph G is bipancyclic if it contains a cycle for every even length from 4 to ${\mid}V(G){\mid}$. In this article, we analyze the conditional edge-fault-tolerant properties of an enhanced hypercube, which is an attractive variant of a hypercube that can be obtained by adding some complementary edges. For any n-dimensional enhanced hypercube with at most (2n-3) faulty edges in which each vertex is incident with at least two fault-free edges, we showed that there exists a fault-free cycle for every even length from 4 to $2^n$ when n($n{\geq}3$) and k have the same parity. We also show that a fault-free cycle for every odd length exists from n-k+2 to $2^n-1$ when n($n{\geq}2$) and k have the different parity.

• 전자공학회논문지B
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• 제30B권5호
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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.

• 한국통신학회논문지
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• 제21권2호
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• pp.427-434
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• 1996

하이퍼큐브 구조는 두 노드간의 직경이 짧고, 노드간의 경로배정이 비교적 간단하다는 장점으로 인해 실제의 시스템에서 많이 이용되고 있다. 그러나 이 구조를 좀 더 실질적으로 만들기 위하여 직경을 줄이고 임의의 노드 갯수로 시스템을 확장할 수 있어야 한다. 본 연구에서는 노드나 링크의 추가없이 기존의 구조의 복잡도를 그대로 유지하면서 직경을 약 50% 정도 줄였던 교차된 하이퍼큐브 구조를 이용하여, 임의의 노드 갯수로 확장할 수 있는 교차된 불완전 하이퍼큐브 구조를 제안하였으며, 이를 위한 경로배정 기법을 제안하였다. 그리고 제안한 구조가 평균 경로길이 및 평균 경로배정시간 측면에서 약 30%, 교통밀도 측면에서 약 20% 향상됨을 입증하였다.

• 한국통신학회논문지
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• 제30권5C호
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• pp.320-328
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• 2005

하이퍼 큐브는 정규적이며 결함 허용 능력을 갖고 있기 때문에 결함 허용 알고리즘을 구현하기 쉽다. 하이퍼 큐브를 이용한 결함 허용 알고리즘들이 많이 개발되었다. 이러한 알고리즘들 중에 안전(safe)과 불안정(unsafe) 개념을 이용한 알고리즘이 Masuyama등에 의해 개발되었다. 이 논문에서는 Masuyama의 알고리즘을 개선한 새로운 알고리즘을 제안하고 시뮬레이션을 통하여 성능을 비교한다.

• 한국통신학회논문지
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• 제21권6호
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• pp.1463-1469
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• 1996

교차된 불완전 하이퍼큐브 구조는 노드나 링크의 추가없이 일반적인 구조의 복잡도를 그대로 유지하면서 직경을 약 50% 정도 감소시킨 교차된 하이퍼큐브 구조를 기반으로 하여 임의 노드의 갯수로 확장할 수 있는 향상된 구조이다. 본 연구에서는 이 구조에 적합한 오류 발생시 대처가능한 오류허용 적응적 경로배정 알고리즘과 방송 알고리즘을 제안하였으며, 이에 대한 성능 평가 실행으로 성능이 30% 향상됨을 입증하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권1호
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• pp.101-113
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• 2015

The Monte-Carlo (MC) technique is very efficient solution for statistical problem. Various MC methods can easily be applied to statistical circuit performance analysis. Recently, as the number of process parameters and their impact, has increasingly affected circuit performance, a sufficient sample size is required in order to consider high dimensionality, profound nonlinearity, and stringent accuracy requirements. Also, it is important to identify the performance of circuit as soon as possible. In this paper, Fast MC method is proposed for efficient analysis of circuit performance. The proposed method analyzes performance using enhanced-precision Latin Hypercube Sampling Monte Carlo (LHSMC). To increase the accuracy of the analysis, we calculate the effective dimension for the low discrepancy value on critical parameters. This will guarantee a robust input vector for the critical parameters. Using a 90nm process parameter and OP-AMP, we verified the accuracy and reliability of the proposed method in comparison with the standard MC, LHS and Quasi Monte Carlo (QMC).

• 한국유체기계학회 논문집
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• 제12권3호
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• pp.7-12
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• 2009

In this paper, shape optimization based on three-dimensional flow analysis has been performed for impeller design of centrifugal compressor. To evaluate the objective function of an isentropic efficiency, Reynolds-averaged Navier-Stokes equations are solved with SST (Shear Stress Transport) turbulence model. The governing equations are discretized by finite volume approximations. The optimization techniques based on the radial basis neural network method are used for the optimization. Latin hypercube sampling as design of experiments is used to generate thirty design points within design space. Sequential quadratic programming is used to search the optimal point based on the radial basis neural network model. Four geometrical variables concerning impeller shape are selected as design variables. The results show that the isentropic efficiency is enhanced effectively from the shape optimization by the radial basis neural network method.

• 한국콘텐츠학회논문지
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• 제2권2호
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• pp.103-111
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• 2002

비록 MIN이 짧은 직경을 갖고 있을지라도 지역화된 통신 형태를 갖는 병렬응용 프로그램에 있어서 hypercube와 fee구조를 비교했을 때 전체적인 시스템 성능은 떨어지게 된다. 그것은 MIN이 지역참조성의 활용할 수 있는 클러스터링 구조를 제공하는 것이 불가능하기 때문이다. 그러나 제안된 MIN은 잦은 데이터 통신 형태를 갖는 프로세서-메모리 클러스터의 내부에 짧은 경로 및 다중 경로를 제공하여 지역화된 통신 구조에 적합하도록 구성할 수 있다. 따라서 제안된 MIN은 지역화된 통신 형태를 갖는 병렬 응용 프로그램에 있어서 향상된 성능을 이룰 수 있게 된다.

• Smart Structures and Systems
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• 제12권6호
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• pp.641-659
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• 2013

In this paper is studied the influence of the uncertain mass distribution over the floors on the choice of the optimal parameters of a hybrid control system for tall buildings subjected to wind load. In particular, an optimization procedure is developed for the robust design of a hybrid control system that is based on an enhanced Monte Carlo simulation technique and the genetic algorithm. The large computational effort inherent in the use of a MC-based procedure is reduced by the employment of the Latin Hypercube Sampling. With reference to a tall building modeled as a multi degrees of freedom system, several numerical analyses are carried out varying the parameters influencing the floors' masses, like the coefficient of variation of the distribution and the correlation between the floors' masses. The procedure allows to obtain optimal designs of the control system that are robust with respect to the uncertainties on the distribution of the dead and live loads.

• 한국공작기계학회논문집
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• 제17권5호
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• pp.95-100
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• 2008

An active micro-mixer, which is composed of an oscillating micro-stirrer in the micro-channel to provide effective mixing was optimized. The effects of molecular diffusion and disturbance by the stirrer were considered with regard to two types of mixer models: the simple straight micro-channel and micro-channel with an oscillating stirrer. Two types of mixer models were studied by analyzing mixing behaviors such as their interaction after the stirrer. The mixing was calculated by Lattice Boltzmann methods using the D2Q9 model. In this study, the time-averaged mixing index formula was used to estimate the mixing performance of time-dependent flow. The mixing indices of the two models were compared. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced and stabilized. Therefore, an approximate optimization of an active micro-mixer with an oscillating stirrer was performed using Kriging method with OLHD(Optimal Latin Hypercube Design) in order to determine the optimal design variables. The design parameters were established as the frequency, the length and the angle of the stirrer. The optimal values were obtained as 1.0346, 0.66D and $\pm45^{\circ}$, respectively. It was found that the mixing index of the optimal design increased by 88.72% compared with that of the original design.