• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.139-142
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• 2004

In this paper, we present a dynamic matching methodology for the logistics brokerage agent that intermediates empty vehicles and freights registered to the logistics e-marketplace by car owners and shippers. In this matching methodology, two types of decisions should be made: one is when to match freights and vehicles and the other is how to match freights and vehicles at that time. We propose three strategies for deciding when to match, i.e. real time matching (RTM), periodic matching (PM), and fixed matching (FM) and use Hungarian method for solving tho how-to-match problem. In order to compare the performance of the when-to-match strategies, computational experiments are done and the results show that the waiting-and matching strategies, PM and FM, give better performance than real time matching strategy, RTM. We can expect that the suggested matching methodology may be used as an efficient and affective tool for the brokerage agent in the logistics e-marketplaces

• Management Science and Financial Engineering
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• v.10 no.1
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• pp.77-96
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• 2004

In this paper, we present a dynamic matching methodology for the logistics brokerage agent that intermediates empty vehicles and freights registered to the logistics e-marketplace by car owners and shippers. In this matching methodology, two types of decisions should be made： one is when to match freights and vehicles and the other is how to match freights and vehicles at that time. We propose three strategies for deciding when to match, ie. real time matching (RTM) , periodic matching (PM), and fixed matching (FM) and use Hungarian method for solving the how-to-match problem. In order to compare the performance of the when-to-match strategies, computational experiments are done and the results show that the waiting-and-matching strategies, PM and FM, give better performance than real time matching strategy, RTM. We can expect that the suggested matching methodology may be used as an efficient and effective tool for the brokerage agent in the logistics e-marketplaces.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.18 no.4
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• pp.295-304
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• 2014

We analyze theMMPP/G/1/K queue with a modified state-dependent service rate. The service time of customers upon service initiation is changed if the number of customers in the system reaches a threshold. Then, the changed service time is continued until the system becomes empty completely, and this process is repeated. We analyze this system using an embedded Markov chain and a supplementary variable method, and present the queue length distributions at a customer's departure epochs and then at an arbitrary time.

• Computers and Concrete
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• v.27 no.3
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• pp.269-282
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• 2021

A dynamic analytical solution for a simply supported, rectangular functionally graded plate with a porous middle layer under time-dependent load based on a refined third-order shear deformation theory with a cubic variation of in-plane displacements according to the thickness and linear/quadratic transverse displacement is presented. The solution achieved in the trigonometric series form and rests on the Green's function method. Two porosity types and their influence on material properties, and mechanical behavior are considered. The network of pores is assumed to be empty or filled with low-pressure air, and the material properties are calculated using the power-law distribution idealization. Numerical calculations have been carried out to demonstrate the accuracy of the kinematic model for the dynamic problem, the effect of porosity, thickness of porous layers, power-law index, and type of loading on the dynamic response of an imperfect functionally graded material plate.

• (The) Research of the performance art and culture
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• no.18
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• pp.171-199
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• 2009

This paper started with my effort to find connections between Empty Hands, which was put on the stage at the Mime House in Chuncheon, Gangwon Province, and Jindo Ssitgimgut. The mimist Yu Jin-gyu(58) adopted so many elements from Jindo Ssitgimgut for his performance that I felt that it was the pantomime version of Jindo Ssitgimgut. Of course, the pantomime took the form of gut based on shamanism in terms of story. Watching the pantomime, I once again saw the possibility of developing Korea's cultural archetypes into cultural contents. Helen Lannaghan, the art director of London International Mime Festival of 2005, saw his performance at the conference of Chuncheon International Mime Festival and invited it to the London International Mime Festival praising that it's full of Korean elements, minimalist, and modern at the same time. In fact, Empty Hands, which boasts great harmony among the Korean objet, Oriental thoughts, Samulnori, and Western contemporary mime, was invited to many foreign festivals including the Mimos International Mime Festival in 2000, Polish International Mime Festival in 2001, Mongol's International Mime Festival in 2002, and Belgium's International Mime Festival in 2003. In addition, it's recognized for its artistic values and had a chance to shine in another international setting at the London International Mime Festival whose reputations have been worldwide. All those achievements are the result of Yu's constant effort to reflect Korean elements through his movements. What I saw in his pantomime was the possibility that plays based on Korea's cultural archetypes such as Jindo Ssitgimgut could play an important role as a global content of performance culture. Pursuing the possibility further, I analyzed the factors that brought the worldwide recognition to Empty Hands and searched for the ways to create solid storytelling with Jindo Ssitgimgut and make a huge hit on the international stage. It should be noted once more that the pantomime Empty Hands launched Korea's unique performance culture to the world stage by making great use of the traditional Korean cultural contents.

• Journal of Family Resource Management and Policy Review
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• v.8 no.3
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• pp.47-64
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• 2004

This study compared full-time housewives' propensity for TV home shopping addiction by different socioeconomic, psychological, and purchase-related characteristics. And it identified the factors that influenced full-time housewives' TV home shopping addiction. The data were obtained from a questionnaire completed by full-time housewives (n=225) lived in Seoul and were analyzed by t-tests, ANOVA, and a multiple regression analysis. The findings of this study were as follows: First, full-time housewives' propensity for TV home shopping addiction was higher in the relatively old aged group. Those who graduated from graduate schools had lower scores in the scale of TV shopping addiction. Also, middle income group showed higher propensity for addictive buying. Second, the propensity for TV home shopping addiction was higher among those who had low self-esteem, who had higher level of empty self Also, those who had experienced material compensations as a child showed higher propensity for addictive purchase. Third, the propensity for addictive buying in TV home shopping was higher among those who had higher propensity for materialism, who took a serious view of markers or friends. Those who abuse their credit cards were more likely to have TV home shopping addiction.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.193-197
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• 2016

There are many hoppers in the actual industrial plants such as grain hoppers in agricultural companies, surge hoppers in steel companies, and so on. In general, they are time-delay systems so that their level control is not easy. Thus, they have been manually controlled to avoid the overflow and empty out. In this paper, we proposed Fuzzy PID controller for level control of hopper systems. To show the effectiveness of the proposed scheme, some simulation results are given.

• IE interfaces
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• v.15 no.3
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• pp.316-324
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• 2002

Automated Guided Vehicles are widely used as an essential material handling system for FMS to provide flexibility and efficiency. We suggest a new dispatching rule based on priority function which considers urgency and empty vehicle travel time under finite buffer capacity. We evaluate the performance of the proposed rule by comparing the performance of Shortest Travel Time/Distance(STT/D) rule in terms of machine utilization, throughput and WIP level using simulation. The simulation results show that the suggested dispatching rule is robust and provides better machine utilization, throughput with comparable WIP level compared to STT/D rule.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.295-300
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• 2004

We consider a G/M/1 queue with two-stage service policy. The server starts to serve with rate of ${\mu}1$ customers per unit time until the number of customers in the system reaches A. At this moment, the service rate is changed to that of ${\mu}2$ customers per unit time and this rate continues until the system is empty. We obtain the stationary distribution of the number of customers in the system.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.3
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• pp.109-123
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• 1999

Fleet sizing and empty equipment redistribution are two of the most critical problems in managing a fleet of equipment over a transportation network. Where the demand pattern followed the compound Poisson process(CPP) which can be generated one or more at a time under homogeneous Poisson process(HPP), this paper presented a mathematical model to determine control parameters of a decentralized distribution policy and fleet size in case of the pure hub-and-spoke system, a popular form of a logistics system. and validated this model by simulation. That is, where the number of demanded equipments followed geometric and binomial distributions, respectively, cost models on the pure hub-and-spoke logistics system with deterministic trans-portation times, which could be solved analytically, were established and analyzed. We also compared the deterministic case with stochastic one that the transportation time follows some probability distributions.