• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.2
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• pp.97-109
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• 2014

This paper considers a reverse supply chain with simultaneous recovery of used products and manufacturing of brand-new ones. Recovered products are downgraded and have to be sold in a market different from that of brand-new products at a different price. In case of a shortage of recovered product inventory, a brand-new item, if available, can be offered at the price of a recovered product. In other words, one-way demand substitution is allowed. We address the joint decision of when to manufacture brand-new product, when to recover returned product, and how to control demand substitution to maximize the hybrid production system's profits. To this end, we propose a Markov decision Process model and investigate the structure of the optimal policy. Performance comparison is numerically implemented between the models with and without downward demand substitution option under different operating conditions of the system parameters.

• ETRI Journal
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• v.28 no.2
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• pp.205-215
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• 2006

Wireless data communication (WDC) services are increasingly penetrating the market. The two main alternative WDC technologies are wireless LAN and mobile Internet. Services based on these technologies display differences in quality attributes such as terminal device, data transmission speed, pricing scheme and so on. How consumers choose between these two alternatives will be determined by their preferences regarding such quality attributes. In turn, their preferences will affect the evolution of WDC services and related technologies. This study employs a conjoint analysis of consumer valuations of quality attributes of wireless LAN and mobile Internet services. Respondents rate hypothetical service alternatives featuring various combinations of quality attributes. By estimating consumer willingness to pay for the attributes of WDC services, the authors predict the evolution of WDC services and related technologies along various quality dimensions, make a comparison with the results of a previous study, and draw policy implications for national-and company-level R&D strategies.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.1-11
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• 2006

Data mining technique is used to find hidden knowledge by massive data, unexpectedly pattern, relation to new rule. The methods of data mining are decision tree, association rules, clustering, neural network and so on. Clustering is the process of grouping the data into clusters so that objects within a cluster have high similarity in comparison to one another. It has been widely used in many applications, such that pattern analysis or recognition, data analysis, image processing, market research on off-line or on-line and so on. We analyze Gyeongnam social indicator survey data by 2001 using twostep clustering technique for environment information. The twostep clustering is classified as a partitional clustering method. We can apply these twostep clustering outputs to environmental preservation and improvement.

• YAKHAK HOEJI
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• v.18 no.1
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• pp.29-38
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• 1974

In order to study the residual amounts of absorbed organochlorine pasticides in vegetables, heptachlor and endrin were sprayed 2,4 and 6kg per 10a., respectively, before sowing the seeds in the station. The experiemental study is primarily concerned with the absorption in lettuce nad garland chrysanthemum. The absorption of each pesticide into lettuce and garland chrysanthemum, and residual pesticides in soil by timne have been analyzed by the gas chromtographic method, and the ratio of residual pesticides in vegetablesand soil were estimated. Heptachlor, heptachlor epoxide and endrin in lettuce nad garland chrysanthemum at the market in Seoul area hvae also analyzed and found extremely low level of pesticides in comparison with the level in above experimental vegetables as well as same vegetables in Japan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.219-220
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• 2017

Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material. Furthermore, the importance of securing the stability of the waterproofing method in the vulnerable over-lap joint areas of waterproofing sheets is emphasized.

• Journal of The Korea Institute of Healthcare Architecture
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• v.12 no.1
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• pp.7-15
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• 2006

The recent change of the medical treatment market is reforming the hospital space. The death-rate caused by cancer diseases is increasing in the domestic and outside of the country. The specialized hospital for cancer patients must be required. This study analyzed the space structures of the main section in cancer hospitals with the comparison analysis method. Space structures of domestic cancer hospitals are not specialized comparing to other nations' cancer hospitals. The conclusion of this research is that we need the architectural planning standards of the specialized cancer hospital through the space structure mainly concerning patients.

• East Asian Economic Review
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• v.18 no.2
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• pp.187-212
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• 2014

The purpose of this paper is to examine the equity market crisis contagion in major Asian economic markets. A comparative assessment of Asian markets during the Asian Financial Crisis and Global Financial crisis may clearly identify the changing nature of long term integration of major Asian markets. The selection criteria of specific Asian markets of different peripheries depend particularly on the roles and structure of these markets. The impact of the global financial contagion and the lingering financial linkage in the aftermath of crisis will explain the reaction of the majority of Asian markets to global linkage. While majority of the studies focused on dynamic short term association in European and MENA contagions in the post global financial crisis period; after the global financial crisis, attention paid to long term Asian contagion adds new perspective to hitherto disorganized theories.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.6
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• pp.691-698
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• 1998

This study investigated the clothing constructional characteristics of contemporary folk Jogori design retailed at the market. This study focussed on comparison of style variation between contemporary Jogori and traditional Jogori. The data were collected from five top contemporary folk dress makers's 997-1998 fall-winter collection. The results of this study were as following. 1) The traditional folk clothing constructional elements remained most among the con- temporary Jogori design were center back seam(Deung-Sol) and attached front bodice extensi on(Sup). Neckline shaping(Geet) and neckline binding(Dong-Jeong) were also observed frequently. 2) The most obvious changes from the traditional Jogori design were elimination of the ribbon fastener in front, adaptation of various neckline shaping used in the Yi dynasty, and lengthened garment length. 3) The western garment construction techniques applied to the contemporary Jogori design were use o( pocket and button closure. The center front extension was replaced with attached front bodice extension(Sup) for a few Jogori design.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.218-219
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• 2007

Silicon feed stock shortage have acted as major restraints for growth of photovoltaic industry. Concentrating photovoltaic (CPV) system will reduce the use of silicon PV materials. This paper presents the application possibility of mono-crystalline silicon solar cell, which has increased in market share, for PV concentrator. We measured the power of solar cell using sun simulator and I-V curve tracer and compared the results. The comparison of results showed that the concentrated solar cell generated the power more approximately 7 times than without concentration in spite of non-heat sink. If CPV technology included heat sink combines already developed PV tracking system, it will have a merit economically.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.610-616
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• 1997

One of the notable changes in Korean Industry in 1990's was globalization. Many of Korea plants have been built In the foreign countries and many of foreign plants have been build in Korea. And it is believed that many foreign insurance companies will begin their business in Korea soon, as Korea will open their insurance market to them. While sprinkler system plays very important role in total fire protection system, Korean sprinkler system design has not been studied in depth. Thus, it is not easy to convince the performance of Korean sprinkler system and compare it to NFPA 13, Standard for the Installation of Sprinkler System. Design guideline from both system will be listed and compared in detail. Fire water demand from both system will be reviewed to evaluate its adequacy. Water spray density and actuation time will be estimated, too.