• Proceedings of the KSR Conference
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• 2001.05a
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• pp.200-206
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• 2001

In the standard specifications for the urban EMU(Electric Multiple Unit) train, there are several items to ensure safety against accidents. The 21th -23th items have much relation with the crashworthiness of the urban EMU train. In this study, the rubber- tired AGT(Automated Guide-way Transit System) under development by KRRI is numerically evaluated in a crashworthy point of view by applying the above crashworthiness items. The numerical results show the detail design of the AGT satisfies the 22th and 23th items. But the design is recommended to adopt mechanical fuses to reduce the impact accelerations with respect to the 21th item.

• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.136-144
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• 2005

This research deals with an order picking problem in automated storage and retrieval systems (AS/RS). When retrieval requests consist of multiple items and the items are in multiple stock locations, the storage/retrieval (S/R) machine must travel to numerous storage locations to complete each order. The aim of this research is to propose algorithms for the resolution of order picking problems with multiple stock locations to minimize the total time traveled by the S/R machine. We present and compare three alternatives for solving the problem based on enumeration, ordinary heuristic and genetic algorithms. We used a set of 180 different problems that are solved by these three algorithms. The results show that our proposed genetic algorithm is more efficient than the other two.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.36-40
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• 2023

Recently, in the problem of multi-order processing in logistics warehouses, multi-pickup systems are changing from the form in which workers walk around the warehouse to the form in which goods come to workers. These changes are shortening the time to process multiple orders and increasing production. This study considered the sequence problem of which warehouse the items to be loaded on each truck come first and which items to be loaded first when loading multiple pallet-unit goods on multiple trucks in an industrial smart logistics automation warehouse. To solve this problem efficiently, we use the mutant algorithm, which combines the GA algorithm and ACO algorithm, and compare with original system.

• Journal of Distribution Research
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• v.4 no.2
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• pp.21-39
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• 1999

This study investigates the general applicability of the measurement scale for assessing channel-member performance for the supplier's view that was proposed by Kumar, and Achrol (1992). First, we attempted to examine whether the measurement-scale could be used without any change; the results from the initial data-analysis proposed that the scale needed a certain amount of a revision for further utilization. It seemed that the scale needed some adjustment for being applied to this study; their scale was developed with the data collected from the network of independent dealers handling multiple product items or multiple brands in the U.S. and Canada, while the data of this study were provided by a Korean car manufacturer having a dealer network selling and servicing only its own brand without ownership. Accordingly, we determined that it was necessary to develop a newly finalized performance-measurement scale revising Kumar et al.'s. During the data-analysis of the data resulted in a scale of fifteen items measuring three facets-financial performance, behavioral performance, and competence, each of which consisted of five items respectively. This empirically developed scale looked more valid for the situation of this study than the Kumar, Stern, and Achrol's which was composed of twenty-one items measuring seven facets--three items each.

• Journal of the Korean Chemical Society
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• v.58 no.3
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• pp.303-312
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• 2014

In this study, we analyzed the characteristics of science academic achievement by multiple culture and North Korean migrant students types, percentage of correct answer and discrimination per items per groups, and contents domains using quantitative and qualitative method in the National Assessment of Educational Achievement (NAEA). As a results of analysis, the degree of science academic achievement of the students from multiple culture and North Korean is much lower than that of the general students. Also, the science academic achievement of the students from multiple culture and North Korean migrant is different from the general students. Especially, science academic achievement of the immigrated students and the North Korean migrant students was lowest. The analysis of items that the difference of the percentage of correct answer was large showed that the students from multiple culture and North Korean migrant were equally weak to it in all contents domains, but that the students from international marriage family born in country were weak in some areas. Therefore, the appropriate the teaching and learning method and the educational support is needed considering the group situation, so the educational implications are discussed.

• Journal of Science Education
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• v.37 no.2
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• pp.278-293
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• 2013

The purpose of this study was to analyze the characteristics of multiple-choice test items used in assessment of high school integrated science according to 2009 revised curriculum. For the analysis of the tendency of item setting, we devised an analytic framework specific to integrated science, and analyzed the characteristics of items by applying the devised framework and item response theory. The results of the tendency of item setting revealed that most of items run counter to the intent of integrated science in terms of item resource, integration extent, and cognitive level, which means teachers are stick to separative method in teaching-learning and assessment of integrated science. The results of the analysis applying item response theory showed that item difficulty was appropriate and item discrimination was considerably high. However, there was no relevance between the tendency of item setting and qualitative characteristics of the items. We also discussed some agendas to improve the teaching-learning and assessment of integrated science based on the results of this study.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.143-147
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• 2006

Several regulations on converting reusable products are established in many countries, due to the emphasis on environmental issues on manufacturing. Many companies consider reusable and returned items in addition to purchasing new items. In this paper we suggest several algorithms to determine the near optimal quantities of items for converting and new items for purchasing. The reusable items are converted into end items, each facing normally distributed demand in a single period of interest. We develop a mathematical model and a genetic algorithm(GA) to compare the number of convertible units and new items to be purchased. Computational results demonstrate the efficiency of the developed algorithms.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.614-619
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• 2005

The object of this study was to presented regression equations for obtaining simply and quickly values of water quality items, BOD, COD, T-N, and T-P. Regression equations obtained to analyze relationships for water quality items to land use types in agricultural reservoir watersheds. In order to derive regression equations, a multiple linear regression analysis was used in this studying reservoirs. In this regression analysis, a independent values used land used types and dependent values used BOD, COD, T-N, T-P values in water quality items. The results showed that numbers of regression equation ranging above 0.90 in a multiple correlation coefficient (MCC) was not found, ranging from 0.70 to 0.90 in the MCC was 6, ranging from 0.40 to 0.70 in the MCC was 20, and ranging from 0.20 to 0.40 in the MCC was 4. The results of this study can be used as a basic information for evaluating simply and quickly water quality for proposing and designing steps in water quality policy.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.1
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• pp.76-89
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• 2013

The exploration of the interaction effect among the components of attractiveness is impossible; therefore, this study uses an indirect estimates approach with multiple scale items that can measure the interaction effect among the components of attractiveness to solve the problem of direct estimates. Previous studies focused on intra-store type competition as their subjects; subsequently, this study dealt with intra-store type competition as well as inter-store type competition in the competing and selecting activities among fashion retailing stores with different business models (such as department stores, road brand stores, discount stores, outlets and internet shopping malls). This study suggests a generalized model for shopping attractiveness of stores and proposes a fashion retailing store type attractiveness (FaRSTA) model instead of a simple relative importance between store selection standards.

• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.403-412
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• 1999

A block replacement policy where at failure the item is either replaced by a new or used item or remains inactive until the next planned replacement is considered. in this paper our interests are focused on reusing all the used items created by the policy. Numerical results for the case where the underlying life distribution is gamma are obtained.