• 제목/요약/키워드: Dependency structure

검색결과 338건 처리시간 0.028초

형식 도구를 이용한 이산사건 시뮬레이션의 모델 형식화 방법론 (A Model Formalization Methodology of Discrete Event Simulation with Formal Tools)

  • 정영식;황종선
    • 한국경영과학회지
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    • 제17권3호
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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.

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Directionality of O-Phthaladehyde adsorbed on H-Si(100) Surface Using NEXAFS and HRPES

  • 김기정;박선민;임희선;김봉수;이한길
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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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.

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망목구조 변화에 따른 에폭시 복합게료의 유전 특성에 관한 연구 (A Study on The Dielectric Characteristics in EPOXY Composites due to Variation of Network Structures)

  • 손인환;이덕진;심종탁;김명호;김경환;최벙옥;김재환
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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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.

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적자병원의 재무구조 및 운영적 특성과 경영의사결정 행태 (Financial Structural and Operational Characteristics and Management Decision-making Behavior of the Red-figured Hospitals)

  • 황인경
    • 한국병원경영학회지
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    • 제4권2호
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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.

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망목 구조 변화에 따른 에폭시 수지의 유전 특성에 관한 연구 (A Study on the Dielectric Characteristics in Epoxy Resins due to Variation of Network Structures)

  • 김재환;손인환;심종탁;김경환;김명호;최병옥
    • E2M - 전기 전자와 첨단 소재
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    • 제10권7호
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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.

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동결건조 분말고추장의 재수화시 리올로지 특성 (Rheological Properties of Rehydrated Suspensions of Freeze Dried Kochujang Powders)

  • 김석신;장규섭;윤한교;이상규;이신영
    • 한국식품과학회지
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    • 제19권2호
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    • pp.81-88
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    • 1987
  • 동결속도를 달리하여 제조한 2종의 동결건조 분말고추장 재수화 현탁액의 리올리지 특성을 원료고추장을 대조구로 온도 $25{\sim}60^{\circ}C$, 고형물 함량 $47{\sim}56^{\circ}C$, 전단속도 $0.1965{\sim}1.9650\;sec^{-1}$의 범위에서 Brookfield 단 원통 회전점도계로 측정하였다. 급속동결 분말고추장 및 완만동결 분말고추장의 재수화 현탁액과 원료고추장은 모두 항복치를 지닌 의가소성을 나타내고. 전단초기 20분까지 Tiu의 모델에 따라 2차 반응속도식으로 붕괴되는 thixotropic거동을 보여주였으며. 분말고추장 현탁액의 구조붕괴 속도가 원료고추장 보다 빨랐다. 평형구조변수는 전단속도에 크게 영향받지 않았으며 그 값은 세가지 시료 모두 비슷하였다. 급속동결분말고추장 및 완만동결 분말고추장의 재수화 현탁액과 원료고추장의 곁보기점도의 온도 의존성은 Arrhenius식과 일치하였으며. 활성화 에너지의 값은 가각 2.21, 2.18, $2.32\;Kcal/g{\cdot}mole $이었다. 세가지 시료의 점조도지수는 온도의 증가에 따라 감소하었으며, 고형물 함량의 증가에 따라 증가하였으나, 유동거동지수는 온두 및 고형물 함량에 거의 영향을 받지 않았다. 급속동결 분말고추장과 완만동결 분말고추장의 러올로지 성질은 큰 차이가 없었다.

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Evaluation of Fracture Strength and Material Degradation for Weldment of High Temperature Service Steel Using Advanced Small Punch Test

  • Lee, Dong-Hwan
    • Journal of Mechanical Science and Technology
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    • 제18권9호
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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.

의료서비스산업의 산업연관분석 (Input-Output Analysis on the Medical Service Industry between Korea and Japan)

  • 이견직;정영호
    • 보건행정학회지
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    • 제10권1호
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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.

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대처(coping)의 개념적 구조 -혈액투석환자를 대상으로- (The Conceptual Structure of Coping -Based on Patients receiving Hemodialysis -)

  • 장성옥;이숙자;김정숙
    • 기본간호학회지
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    • 제7권1호
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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.

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Improved Method and Message Structure Design for TWSTFT without Extra Network

  • Juhyun Lee;Ju-Ik Oh;Young Kyu Lee;Sung-hoon Yang;Jong Koo Lee;Joon Hyo Rhee
    • Journal of Positioning, Navigation, and Timing
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    • 제12권2호
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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.