• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.753-757
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• 2008

In this paper, we propose a new scheduling strategy for dynamic programming in Grid environment. The key idea of this scheme is to reduce the execution time of a job by dividing the dynamic table based on the locality of table and allocating jobs to nodes which minimize network latency. This scheme obtains optimal concurrency by constructing the dynamic table using a distributed top down method. Through simulation, we show that the proposed Grid strategy improves the performance of Grid environment compared to previous branch-bound strategies.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1815-1818
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• 2002

사용자에게 서비스 할 데이터가 많을 경우 데이터베이스의 여러 볼륨에 저장해서 처리해야 할 경우가 발생한다. 볼륨이 여러 개일 경우 효과적이고 효율적인 접근 방법이 필요하다. 본 논문에서는 SHORE 저장 시스템을 이용할 경우에 효과적이고 효율적인 접근 방법을 알아보고자 한다. single thread, multi thread, multi process, socket 을 이용한 접근 방법을 살펴보고 multi thread 를 이용하는 방법이 가장 효율적인 것을 실험 결과를 통해서 보인다. SHORE thread 는 CPU bound 에 과련된 job 이 많은 경우는 process 를 사용했을 때에 비해 큰 효과가 없으나 I/0 bound 에 관련에 것일 경우는 multi process 를 사용한 것과 비슷한 효과가 있음을 알 수 있다.

• Elastomers and Composites
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• v.34 no.3
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• pp.262-268
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• 1999

Effect of carbon blacks (CBs) on the stress relaxation and the elastic recovery of uncrosslinked natural rubber (NR) was examined. It was found that if the type of CB is characterized by smaller size and higher structure, the stress relaxation is more delayed and the elastic recovery becomes more active. These results are attributed to the degree of bound rubber, i.e., the interaction between NR and CB.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.237-249
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• 1999

It has been issued that the irreconcilability of the classical test for a point null and standard Bayesian formulation for testing such a point null. The infimum of the posterior probability of the null hypothesis is used as measure of evidence against the null hypothesis in Bayesian approach; here the infimum is over the family of priors on the alternative hypotheses which includes all density that are a priori reasonable. For iid observations from a multivariate normal distribution in $\textit{p}$ dimensions with an unknown mean and a covariance matrix propotional to the Identity we consider the difference and the Wolfowitz distance of the distributions of the P-value and the lower bound of the posterior probability over the family of all normal priors. The Wolfowitz distance is interpreted as the average difference of the quantiles of the two distrbutions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.3
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• pp.113-121
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• 2014

This paper considers a scheduling problem in a two-machine flowshop with outsourcing strategy incorporated. The jobs can be either processed in the first machine or outsourced to outside subcontractors. This paper wants to determine which jobs to be processed in-house and which jobs to be outsourced. If any job is decided to be outsourced, then an additional outsourcing cost is charged The objective of this paper is to minimize the sum of scheduling cost and outsourcing cost under a budget constraint. At first this paper characterizes some solution properties, and then it derives solution procedure including DP (Dynamic Programming) and B&B (Branch-and-Bound) algorithms and a greedy-type heuristic. Finally the performance of the algorithms are evaluated with some numerical tests.

• Transactions of Materials Processing
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• v.7 no.4
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• pp.340-346
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• 1998

A kinematically admissible velocity field is developed for the analysis of twisting of the extruded products with elliptical shapes from round billet. The twisting of extruded product is caused by the lin-early increased rotational velocity from the center on the cross-section of the workpiece at the die exit. In the analysis the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is zero at the die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product in creases with the die twisting angle, the aspect ratio of product the friction condition, the reduction of area, and decreases with the die length.

• Korean Journal of Optics and Photonics
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• v.29 no.2
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• pp.64-69
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• 2018

In this work, we derive a general lower bound to concurrence of an arbitrary mixture of two pure states, that is, rank-two multipartite quantum states. We show that the lower bound can tightly detect entanglement of rank-two states, and also can be implemented experimentally with present-day technologies, i.e. single-copy level measurement and classical post-processing.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.161-167
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• 1993

This paper presents robustness properties of the Kalman Filter ad the associated LQG/LTR method for linear time-invariant systems having delays in both the state and output. A circle condition relating to the return difference matrix associated with the Kalman filter is derived. Using this circle condition, it is shown that the Kalman filter guarantees(1/2, .inf.) gain margin and .+-.60.deg. phase margin, which are the same as those for nondelay systems. However, it is shown that, even for minimum phase plants, the LQG/LTR method can not recover the target loop transfer function. Instead, an upper bound on the recovery error is obtained using an upper bound of the solution of the Kalman filter Riccati equations. Finally, some dual properties between output-delated system and input-delayed systems are exploited.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.573-576
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• 1996

We propose robust control scheme for flexible joint manipulator in the presence of nonlinearity and mismatched uncertainty. The control is designed based on Lyapunov approach. The robust control which is based on the computed torque scheme and state transformation via implanted control is introduced. The design procedure starts with the construction of linearized subsystems via the computed torque method and then uses state transformation. With this approach we do not impose an upper-bound constraint on the inertia matrix in case it is known. Thus, this control can be applied to arbitrary manipulators. The resulting robust control guarantees practical stability for both the transformed system and the original system. The transformation is only based on the possible bound of uncertainty.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.3
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• pp.163-168
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• 2000

The problems of mixed $H_2/H_{\infty}$ filtering design fer continuous and discrete time linear systems with time delay are investigated. The main purpose is to design a stable mixed $H_2/H_{\infty}$ filter which minimizes the H$_2$Performance measure satisfying a prescribed H$_{\infty}$ norm bound on the closed loop system in continuous-time case and discrete-time case, respectively. The sufficient conditions of existence of filter, the mixed $H_2/H_{\infty}$ filter design method, and the upper bound of performance measure are proposed by LMI(linear matrix inequality) techniques in terms of all finding variables. Also, we present optimization problems in order to get the optimal mixed $H_2/H_{\infty}$ filter in continuous and discrete time case, respectively.