• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.620-623
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• 2001

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid state phase synthesis for production of high temperature superconductor materials are discussed. Oxide superconductors with general formula $ReBa_2$$Cu_3$$O_{7-x}$ (Re= Y, Yb, Sm, Nd) have been made with using barium oxide initial powder instead of traditional barium carbonate. X-ray powder diffraction showed a single phase orthorhombic perovskite structure was produced in all reactions. Phenomena observed during the grinding of the reactant mixture are presented. Mechano-chemical activation - as a pretreatment of the reactant mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.275-280
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• 2002

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid-stave chase synthesis for production of high temperature superconductor materials were discussed. Oxide superconductors with general formula of $ReBa_2Cu_3O_{7-x}$ (Re=Y, Sm) haute been made by using barium oxide initial powder instead of traditional barium carbonate. Phenomena observed during the grinding of the reactants mixture are presented. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• The International Journal of Costume Culture
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• 제3권1호
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• pp.21-29
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• 2000

The purpose of this study was to analyze the 21C Fashion's expression related to 'Verfremdung' theory, in aesthetic theories established after modern times, and then to examine a new meaning and value. The expressions of 'Verfremdung(estrangement)' in modern fashion, appear the followings: 1) placing distance with traditional sex and rational beauty of body. 2) paradox of inversion, 3) illogical juxtapositions by encounter. 4) dismantlement of material concept etc. After showing practically production technique that breaks traditional exception, that is, a new design method of open concept which drives positive idea about discrepancy of realities. This trial has warning abut art's self-control occurring at the time when aesthetic disinterestedness theory is expanded, and is considered indictment about a inhuman property of modern civilization and culture, and is considered expression of will to show alienation by it.

• 한국세라믹학회지
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• 제31권12호
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• pp.1437-1442
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• 1994

Self propagating synthesis and thermal explosion of combustion reactions were applied to Al/K2Cr2O7/Al2O3 system as the first stage for a production of magnesia-chromium refractory. Several factors related to products made by two combustion reactions were considered and properties of products were characterised. Two processes were required to preheat upto at least 80$0^{\circ}C$ for the thermal explosion and the self propagating synthesis. These processes were so violent and explosive that alumina as diluent was added to the system in order to absorb the reaction heat and reduce the reaction rate. The products consisted of crystal phases of KAl5O8, Cr2O3, Al2O3, K2CrO4, and K2Al2O4.3H2O. The amount of KAl5O8 and K2Al2O4.3H2O crystal phases of products were decreased with further addition of alumina.

• Journal of Information Technology Applications and Management
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• 제15권1호
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• pp.243-260
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• 2008

To prevent low yields in the semiconductor industry is crucial to the success of that industry. However, to prevent low yields is difficult because of too many factors to affect yield variation and their complex relation in the semiconductor manufacturing process. This study presents a new efficient detection methodology for detecting abnormal yields including high and low yields, which can forecast the yield level of a production unit (namely a lot) based on yield-related feature variables' behaviors. In the methodology, we use C5.0 to identify the yield-related feature variables that are the combination of correlated process variables associated with yield, use SOM (Self-Organizing Map) neural networks to extract and classify significant patterns of past abnormal yield lots and finally use C5.0 to generate classification rules for detecting abnormal yield lot. We illustrate the effectiveness of our methodology using a semiconductor manufacturing company's field data.

• 산업경영시스템학회지
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• 제23권61호
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• pp.137-146
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• 2000

One of the problems faced in implementing cellular manufacturing systems is machine-part group formation. This paper proposes machine-part grouping algorithms based on Self-Organizing Map(SOM) neural networks and K-Means algorithm in cellular manufacturing systems. Although the SOM spreads out input vectors to output vectors in the order of similarity, it does not always find the optimal solution. We rearrange the input vectors using SOM and determine the number of groups. In order to find the number of groups and grouping efficacy, we iterate K-Means algorithm changing k until we cannot obtain better solution. The results of using the proposed approach are compared to the best solutions reported in literature. The computational results show that the proposed approach provides a powerful means of solving the machine-part grouping problem. The proposed algorithm Is applied by simple calculation, so it can be for designer to change production constraints.

• Journal of Nutrition and Health
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• 제22권2호
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• pp.108-117
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• 1989

The purpose of this study was aimed to investigate the historical tends of population growth which has reflected direct effect of the ratio of food self sufficiency in Korea between the year of 1910 and 1980. Author divided the whole years between 1910 and 1980 into five different periods ; colonial period from 1910 to 1945, post colonial period from 1945 to 1950, Korean war period from 1950 to 1955, post Korean war period from 1955 to 1960, fast economic growing period 1960~1980. The ratio of national food self sufficiency has been profoundlly affected by dual factors ; rate of population group and increment of GNP which reflect the national economic development. Total food production never reached the level of population growth ratio in Korea. As a result food demand and supply has shown imbalaced condition which leads to import foods from outside contury to compensate food shortage. The increment of GNP sharply cut down the cereal consumption. The consumption of fish, milk, eggs and meat reflected to increase since 1970.

• 한국정밀공학회지
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• 제32권1호
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• pp.39-47
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• 2015

Globalization, unpredictable markets, increased products customization and frequent changes in products, production technologies and machining systems have become a complexity in today's manufacturing environment. One key strategy for coping with the evolution of this situation is to develop or apply an enable technology such as intelligent manufacturing. Intelligent manufacturing system (IMS) is characterized by decentralized, distributed, networked compositions of heterogeneous and autonomous systems. The model of IMS is inherited from the organization of the living systems in biology and nature so that the manufacturing system has the advanced characteristics inspired from biology such as self-adaptation, self-diagnosis, and selfhealing. To prove this concept, an innovative system with applying the advanced information and communication technology such as internet of things, cognitive agent are proposed to integrate, organize and allocate the machining resources. Innovative system is essential for modern machining system to flexibly and quickly adapt to new challenges of manufacturing environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.79-81
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• 1987

Expert systems have a variety of potential applications in process control. The application domain ranges from the entire plant system to a single loop system. Both, off-line and real-time problems may be realized. In this paper, expert system is employed as a part of a single control loop of PID Controller with self-tuning. The goal of expert system in the present study is to build up the necessary process knowledge required for efficient control. In order to achieve this process, the development of an expert system and a prototype model is carried out. OPS5, a rule based production system, is utilized in experiment, and common LISP is used for man-machine interface.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.177-180
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• 1997

A new excitation method of switched reluctance moor drive is described in this paper. This motor produces reluctance torque by mutual action between tyro phases as well as conventional self reluctance torque. The change of self inductance and mutual inductance are used to produce torque. This paper suggests the operational principle, the mechanism of torque product and the driving characteristics of Switched Reluctance Motor with 2 phase excitation against conventional SRM experimentally. The energy conversion ratio is increased because the next phase is excited after one phase is already excited. Acoustic noise of SRM with 2 phase excitation is decreased than that of conventional SRM due to the mechanism of torque production.