• Journal of the Korean Operations Research and Management Science Society
• /
• v.19 no.2
• /
• pp.1-19
• /
• 1994

A generalized network problem is a special class of linear programming problem whose coefficient matrix contains at most two nonzero elements per column. A generalized network problem with 0-1 flow restrictions is called an integer generalized network(IGN) problem. In this paper, we presented a branch and bound algorithm for the IGN that uses network relaxation. To improve the procedure, we develop various strategies, each of which employs different node selection criterion and/or branching variable selection criterion. We test these solution strategies and compare their efficiencies with LINDO on 70 randomly generated problems.

• Communications for Statistical Applications and Methods
• /
• v.13 no.3
• /
• pp.765-776
• /
• 2006

In this paper we propose an estimation method on the regression model with randomly censored observations of the training data set. The weighted least squares support vector machine regression is applied for the regression function estimation by incorporating the weights assessed upon each observation in the optimization problem. Numerical examples are given to show the performance of the proposed estimation method.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.4
• /
• pp.543-548
• /
• 2007

We present a dynamic Bayesian network (DBN) model of a generalized class of nonstationary birth-death processes. The model includes birth and death rate parameters that are randomly selected from a known discrete set of values. We present an on-line algorithm to obtain optimal estimates of the parameters. We provide a simulation of real-time characterization of load traffic estimation using our DBN approach.

• IE interfaces
• /
• v.17 no.spc
• /
• pp.90-96
• /
• 2004

In this paper, we consider the joint replenishment problem of a one-warehouse, n-retailer system. We introduce a joint replenishment and delivery strategy of a warehouse and develop a mathematical model based on the proposed strategy. Two efficient algorithms are presented and compared using numerical examples. The proposed strategy is compared with the common cycle strategy for 1,600 randomly generated problems, and has been proven to be superior to the common cycle strategy.

• Journal of Microbiology and Biotechnology
• /
• v.5 no.2
• /
• pp.110-113
• /
• 1995

Transposon Tn5 was used to induce random insertional mutations in Bradyrhizobium japonicum, a soybean endosymbiont. By genomic Southern blot analysis, transposition events were found to have occurred randomly throughout the B. japonicum genome. After screening 3, 626 mutants by auxotrophy test, a histidine auxotroph was isolated. Upon plant infection test, the His mutant showed a 3~4 day delay in nodule formation.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.5 no.2
• /
• pp.87-97
• /
• 1999

This study is concerned with developing a hybrid heuristic algorithm for solving the redundancy optimization problem which is very important in system safety, This study develops a HH(Hybrid Heuristic) method combined with two strategies to alleviate the risks of being trapped at a local optimum. One of them is to construct the populations of the initial solutions randomly. The other is the additional search with SA(Simulated Annealing) method in final step. Computational results indicate that HH performs consistently better than the KY method proposed in Kim[8]. Therefore, the proposed HH is believed to an attractive to other heuristic methods.

• Journal of the Korean Institute of Navigation
• /
• v.16 no.3
• /
• pp.65-76
• /
• 1992

An algorithm to determine the optimum nominal value of geometrical and material parameters in divice modelling is proposed. The algorithm uses the yield and variance prediction formula and Monte-Carlo analysis. The performance specification of the noise figure must also be satisfied. In this paper, the total number of considered devices is 1000, and each parameter of geometrical and material parameters is generated randomly within the limits of ${\pm}3%$ of nominal value, and the distribution of 1000 geometrical and material parameters is gaussing distribution.

• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.700-702
• /
• 1999

The protection of data which we want to keep secret from invalid users has become a main topic nowadays. This paper introduces a encryption scheme for protecting speech signals from eavesdropping. The proposed encryption scheme adopts a secure voice cryptographic algorithm based on the scrambling in frequency band. In order to improve the conventional speech signal encryption scheme, we have randomly permuted DCT coefficients of speech signal. Simulation results are included to show the performance of the proposed algorithm for secure transmission of speech signals.

• Communications for Statistical Applications and Methods
• /
• v.5 no.3
• /
• pp.695-706
• /
• 1998

In this paper we consider the setting where a group of n judges are to independently rank a series of κ objects, but the intended complete rankings are not realized and we are faced with analyzing randomly incomplete rank vectors. We discuss some tests based on Friedman statistics on the designs completed through rank imputation schemes suggested by Lordo and Wolfe (1994) and evaluate them on the basis of simulated power studies, constructing their appropriate null distributions.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2007.06a
• /
• pp.234-237
• /
• 2007

We fabricated nano-structures of the anodic aluminum oxides on sapphire substrates. Two processes of nano-structured sapphire surface have present: the one is the template mask and the other is the anodic oxidized aluminum deposited on sapphire substrate. The formation of nano-structures has investigated by FE-SEM measurement. The etched surface by the template showed periodic lattice but the deposited surface showed the randomly distributed phase of nanoholes instead of the periodic lattice.