• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.79-99
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• 1992

The DEVS (Discrete Event system Specification) formal model for discrete event simulation is a hierarchical, modular model. Because the DEVS formal model has a mathematical structure, it provides a theoretic background of discrete event simulation model. However, the DEVS formal model is difficult to understand because of its mathematical structure. Also, since the DEVS formal model is often constructed by heuristic, subjective method of model designer from the model, a systematic model built-in methodology does not exist. In this paper, we propose the model formalization methodology from an informal model to the DEVS formal model. For this formalization methodology, we introduce formal tools for model construction based on the DEVS ( from an informal model : Event Dependency Graph (EDG) for the event analysis and State Representation Graph(SRG) for the system state analysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.79-79
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• 2010

The electronic and adsorption structure of O-Phthaladehyde (OPA) on the H-Si(100) surface was investigated by using Near Edge X-ray Fine Structure (NEXAFS) and high resolution photoemission spectroscopy (HRPES). We confirmed that the OPA grown on the H-Si(100) surface showed good dependency with about 60 degree tilting angle using NEXAFS and a single O 1s peak by using HRPES. Hydrogen atom passivated on the Si(100) surface was found to be a seed for making one dimensional organic line that uses a chain reaction as the H-Si(100) surface was compared with the hydrogen free Si(100) surface. Through the spectral analysis, we will demonstrate 1-D directional formation of OPA on H-Si(100) surface using NEXAFS and HRPES.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.202-205
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• 1996

In this paper it is researched a relation between network structures and electrical properties - especially dielectric characteristics with changing of network structure. It is resulted that the specimens which have single network structures have smaller dielectric loss than SIN specimens but have relatively larger dependency to variation of temperature and frequency. For that reason formation of structures is attained by introducing of SIN to insulating materials. therefore it is counted that introduction of multiple structure including SIN is necessary to improve heat proof and electrical properties.

• Korea Journal of Hospital Management
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• v.4 no.2
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• pp.305-329
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• 1999

Financial ratio indicators of the 46 sample hospitals provided by the Korea Health Industry Development Institute, together with the survey data responded by the 57 sample hospitals, were analysed to identify the characteristics of the red-figured hospitals' financial structure, financial operational efficiency and management decision-making behavior, The financial characteristics identified through the analysis include high dependency to liabilities, high salary expenses and overhead costs, low profitability of the unduly large amount of fixed assets, and low managerial efficieny of inventory. The hospitals, in face of the IMF economic impasse, took the necessary decision-making and counter measures to cut down salary expenses, to increase the number of patient and medical revenue, and to reduce investment to fixed assets. Based on these findings this study suggested that the hospitals should take more active cost containment measures, financial structural reorganization, and developoment of the strategies that can contribute to increase of the number of patient and medical revenue and that do not. require much capital funds.

• Electrical & Electronic Materials
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• v.10 no.7
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• pp.651-658
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• 1997

In this paper, effect of interpenetrating polymer network(IPN) introduction on the dielectric properties, heat proof properties, internal structure and defects of the Epoxy/SiO$_2$composite materials, were investigated. we reported a relation between network structures and electrical properties, especially dielectric characteristics with variation of network structures for epoxy composite materials. According to experimental results, the specimens which have single network structures have lower dielectric constant than interpenetrating polymer network(IPN) specimens, but have relatively larger dependency to variation of temperature and frequency. It was confirmed that change of structures is attained by introducing of IPN to insulating materials. Therefore it is counted that introduction of multiple structure including IPN is necessary to improve heat proof and electrical properties.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.81-88
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• 1987

Rheological properties of rehydrated suspensions of two kinds of freeze dried Kochujang powders, processed at different freezing rates, were compared with raw Kochujang using Brookfield wide-gap rotational viscometer at $25^{\circ}C-60^{\circ}C$. Shear rates ranged from $0.1965\;sec^{-1}$ to $1.9650\;sec^{-1}$ and solid content ranged from 47% to 56%. Rehydrated suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang exhibited pseudoplastic behaviors with yield stress and presented thixotropic properties which followed the second-order kinetic behavior proposed by Tiu. Suspensions of Kochujang powders exhibited considerably higher decaying rates than raw Kochujang. The dependency of the equilibrium structure parameter on the shear rate was weak, and there were no significant differences among the values of structure parameters of three samples. The temperature dependency of the apparent viscosity of Kochujang suspension was fully expressed by Arrhenius equation and activation energies of suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang were 2.21, 2.18, and 2.32 Kcal/g.mole respectively. Consistency indices of three samples increased with solid content and decreased with temperature. Flow behavior indices of three samples showed no considerable dependency on the temperature and solid content. There were no significant differences in the rheological properties between two Kochujang powders.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1604-1613
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• 2004

This paper presents an effective and reliable evaluation method for fracture strength and material degradation of the micro-structure of high temperature service steel weldment using advanced small punch (ASP) test developed from conventional small punch (CSP) test. For the purpose of the ASP test, a lower die with a minimized ${\Phi}$1.5 mm diameter loading ball and an optimized deformation guide hole of ${\Phi}$3 mm diameter were designed. The behaviors of fracture energy (E$\_$sp/), ductile-brittle transition temperature (DBTT) and material degradation from the ASP test showed a definite dependency on the micro-structure of weldment. Results obtained from ASP test were compared and reviewed with results from CSP test, Charpy impact test, and hardness test. The utility and reliability of the proposed ASP test were verified by investigating fracture strength, behavior of DBTT, and fracture location of each micro-structure of steel weldment for test specimen in ASP test. It was observed that the fracture toughness in the micro-structure of FL＋CGHAZ and ICHAZ decreased remarkably with increasing aging time. From studies of all micro-structures, it was observed that FGHAZ microstructure has the most excellent fracture toughness, and it showed absence of material degradation.

• Health Policy and Management
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• v.10 no.1
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• pp.126-147
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• 2000

This paper empirically explores the nature of the medical service industry and its various propagation effects on the economy in the input-output model, as revealed by a comparative analysis between Korea and Japan. The main findings of the paper are as follows; First, the growth of medical industry induces above-average effect on employment. Second, the industry is of the characteristics of weak both backward and forward linkage effects implying a 'final demand dependency industry'. When compared with public service sectors, however, the medical services industry shows stronger backward linkage effect than those sectors. Furthermore, it has strong repercussion effects on the goods industries. Third, in order to produce per unit of services, the medical services industry of Korea uses relatively more drugs and medical devices than that of Japan. In general, it has been shown that production structure of medical service industry in Korea is 'hardware-oriented' one; on the other hand, 'software-oriented' in Japan which means that, as intermediate inputs, outsourcing and informatization has been used than those of Korea. From the findings of the paper it could be emphasized that the medical organizations in Korea should put more efforts on shifting the current hardware-oriented production structure to strengthen core competence by enhancing productivity and by outsourcing to improve efficiency of production process. However, the medical organizations in Korea would not have enough incentives for high value-added production structure because they enjoy high operating surplus. Therefore, it would be necessary that government policy should be taken into account of these environments.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.1
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• pp.42-59
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• 2000

This study was done to analyze and develop the concept of coping in patients receiving hemodialysis. The Hybrid Model of concept development was applied to develop a conceptual structure of coping in patients receiving hemodialysis, which included a field study carried out using an in-dept interview with 18 patients in the hemodialysis room of one general hospital in Seoul. Data-analysis was done in three phases as suggested by the Hybrid Model. Finally, by summarizing the results from each case, the attributes of coping, its dimensions, definition and structure were outlined. According to the results of the study, a conceptual structure of coping which centers around stressors, stress-appraisal, strategy of coping and new definitions of coping in patients receiving hemodialysis was suggested : The coping of patients receiving hemodialysis is a process that deals with physical, emotional, inter-personal, and role stress caused by hemodialysis due to renal failure. It has a series of phases which include a phase that appraises the stressful situation based on past experience of chronic disease management, one's remaining rears, the extent of family support, the extent of economic dependency, inter-personal support. education and uncertainty, and a phase of developing coping strategies that con be affected by social support and self esteem. As a result of coping, patients adapt or not to the life situation of receiving hemodialysis.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.201-209
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• 2023

Time comparison techniques are required for generating and keeping Coordinated Universal Time (UTC) and to distribute standard clocks. These techniques play an important role in various fields, including science, finance, military, and communication. Among these techniques, Two-Way Satellite Time and Frequency Transfer (TWSTFT) ensures a relatively high accuracy, with a time comparison accuracy at a nanosecond level. However, TWSTFT systems have some limitations, such as the dependency on extra network links. In this paper, we propose an improved method for TWSTFT system operation and design a message structure for the suggestion. Additionally, we estimate the data rate and redundancy for the new TWSTFT signal with the designed message structure.