• 한국초전도ㆍ저온공학회논문지
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• 제12권1호
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• pp.66-70
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• 2010

The operational temperature range of thermosiphon is generally limited from the critical point to the triple point of the working fluid to maintain two-phase state. Thermosiphon with mixed working fluid has a potential to widen the operational temperature range. In this study, the physical behavior of mixed working fluid during the transient operation of thermosiphon was analyzed with temperature-mole fraction diagram. The condenser and the evaporator temperature variations were explained by the dew line and the bubble line of the mixture. It is encouraging that the thermosiphon operation commences early with larger fraction of high boiling point component, but the temperature gap between the condenser and the evaporator due to the separation of two components has a negative effect on the officient cool down process.

• 한국산학기술학회논문지
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• 제20권4호
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• pp.479-488
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• 2019

비행시험 운용절차는 유도무기 비행시험 시스템 설계 및 구현을 위한 중요 산출물의 하나로서 비행시험 진행 단계별 임무계획, 수행방법, 안전대책 등을 포함한다. 유도무기체계 개발이 첨단화, 전략화 됨에 따라서 유도무기 비행시험은 점차 복잡화, 광역화 되고 있다. 이에 따라 시험안전을 확보하기 위해서는 비행시험 운용절차의 신뢰성 증대가 요구되었다. 특히, 새로운 개념의 비행시험 수행을 위해서 시험 전 불확실성을 예측하고 대비할 수 있도록 비행시험 운용절차 설계에서 M&S 기법의 적용을 통한 검증이 필요하게 되었다. 관련 연구로서 비행시험의 최적 프레임워크 개발 연구와 비행시험 프로세스 모델기반 개선 연구들이 발표되었지만, 상위 개념의 프로세스를 중심으로 한 결과로서 하위 수준의 비행시험 자원과 연동하는 비행시험 운용절차에 직접 적용하기에는 구체성이 부족하였다. 또한, 기존의 문서기반으로 구성된 비행시험 운용절차는 시험자원의 거동과 성능에 대한 분석능력의 한계로 시험자원의 중복과 누락, 직관적이지 않는 표현으로 운용자 간의 의사소통 저하, 그리고 다수의 비행시험에 적용하기 위한 확장성 부족 등의 문제가 발생하였다. 이를 개선하기 위해 본 논문에서는 모델기반 시스템공학(MBSE) 기법의 적용을 통한 유도무기 비행시험 운용절차의 설계 방법을 제안하였다. 구체적으로 이전의 비행시험 정보를 기반으로 비행시험 진행 단계와 수행방안을 정의한 후, 요구사항으로부터 시험자원의 임무수행을 SysML 모델 기반으로 구성한 템플릿으로 제공하였다. 또한 시뮬레이션 분석을 통해서 정상상황과 비상상황에 대한 최적의 수행절차를 도출하였으며, 사례 적용을 통해서 검증하였다. 본 연구를 통해서 시험자원의 거동과 성능에 대한 분석능력의 증대로 신뢰성이 향상되었고, 다수의 비행시험에 적용할 수 있는 확장성으로 효율성이 증대되었으며, 향후 개발 예정인 유도 무기 비행시험에도 지속적으로 활용할 수 있다.

• 디지털산업정보학회논문지
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• 제15권2호
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• pp.87-99
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• 2019

The purpose of this study is to examine an organizational ICT(Information and Communication Technology) performance by ICT investment and policy consistency of government organizations. As the rapid development of ICT is becoming an essential element of social culture, the ICT operation of bureaucratic government also is becoming important. The central government has invested substantially new ICT for improving the quality of nationwide service and to promote administrative efficiency. However, various departments of government occur frequently duplication investments of ICT, and budget conflicts between organizations caused difficulties in maximizing ICT competency. I will confirm the ICT operational performance by ICT investment behavior and organizational work competency as well as the significance of ICT policy consistency. The method of study used a structural equation. The research model set ICT investment behavior as independent variables, organizational work competencies and policy consistency as mediations, and operational performance as dependencies. As a result of the research, New ICT interests show negative effects that caused work change between government organizations and government-funded body. But, New ICT convergence shows positive effects on increasing the two competency variables. The two competency variables show negative effects that caused changes in ICT policy consistency and show no impact on the ICT operational performance. The ICT policy consistency shows a positive effect on enhancing ICT operational performance. The study contribution explain updated the contingency theory and because the ICT policy consistency is essential, negotiation between government organizations will be important. Future research will require a qualitative study through interviews in government organizations about consistency enhance of ICT policy.

• 유통과학연구
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• 제14권1호
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• pp.75-84
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• 2016

Purpose - In accordance with the recent changes in the management environment, leaders are required to have an ability of drawing and inducing potential of each worker. Coaching, as one of the strategies of human resources development, is drawing people's attention. This study aims to inquire about the mechanism of leader's coaching behavior which influences the attitude and behavior of workers. Firstly, this study intends to illustrate what kind of influences the leader's coaching behavior can give on organizational citizenship behavior and turnover intention of workers. Secondly, it plans to verify the mediating effect of authentic leadership in the relationship between leader's coaching behavior and organizational citizenship behavior and turnover intention of workers. Thirdly, it aims to prove the moderating effect of emotional intelligence in the relationship among leader's coaching behavior, organizational citizenship behavior and turnover intention of workers. Research design, data and methodology - In order to figure out how the leader's coaching behavior influences attitude of workers, authentic leadership is considered as mediating effect. As for a moderating effect, we have determined emotional intelligence which attracts attention in the recent studies on organizational behavior, so as to investigate the correlation among variables. As for study sample, it was targeted to 236 organizational members of distribution corporations whose leader's coaching behavior is required. For reaching the purpose of study, SPSS 20 was applied for the analysis. Results - The research findings can be summarized as follows: Firstly, leader's coaching behavior gives significant positive influences on organizational citizenship behavior. Moreover, leader's coaching behavior gives negative influences on turnover intention of organizational members. Secondly, the mediating effect of authentic leadership was proved in the relationship between leader's coaching behavior and attitude of workers. Based on the analysis, it turned out that authentic leadership doesn't give a mediating effect in the bilateral relationship. Lastly, the moderating effect of emotional intelligence was proved in terms of how the leader's coaching behavior influences the attitude of workers. The research result shows that the emotional intelligence influences towards the negative direction, in the correlation between coaching behavior and organizational citizenship behavior On the other hand, in the relationship with turnover intention, It was significant effect. Conclusions - Based on the research findings, we have intended to inquired about the mechanism of leader's coaching behavior which influences the attitude and behavior of workers. Furthermore, in the operational level, the following implications can be given: the importance of coaching activation in the operational level was confirmed, through inquiring into the influence of leader's coaching behavior on workers. Moreover, the importance of emotional intelligence, which has been steadily raised, was also confirmed. It is necessary for future study to carry out additional research on various factors of coaching which can influence the effectiveness of coaching, for instance, coaching process, coach's competency, characteristics of coaching customers, relationship with coaching customers and coaching system.

• 산업경영시스템학회지
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• 제43권3호
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• pp.53-60
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• 2020

Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.226-229
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• 2008

To investigate an in-pile behavior of the newly developed DUO fuel pellet, the irradiation test will be carried out in the domestic test reactor. Irradiation test capsule for the HANARO reactor, which is a specially designed equipment used for material, irradiation and creep test, must satisfy the operational requirement on the hydraulic characteristics and structural integrity. In this study, a pressure drop, a flow-induced vibration and a short-term endurance test for the newly developed non-instrumented test capsule were carried out using FIVPET as a out-pile evaluation test. The test results show that the new test rig satisfy the HANARO operational requirement with sufficient margin.

• Child Health Nursing Research
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• 제9권1호
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• pp.74-84
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• 2003

This study was designed to investigate effects of maternal education using Brazelton Neonatal Behavioral Assessment Scale(the following will be marked as NBAS) on the mother-infant interaction and infant behavior. The subjects of this study consisted of 48 pairs of normal mother and infant, 24 pairs for intervention group and 24 pairs for control group. The subjects were recruited from two general hospitals, and an OBGY clinic located in J city. The data were collected from July 30, 2001 to October 6, 2001. Prior to investigation and data collection, following operational hypotheses were set up in order to compare the investigative data against these operational hypotheses(H). H1: Intervention group will higher mother-infant interaction score than control group. H2: Intervention group infants will higher overall performance in infant behavior test score than control group infants. The results of this study were summarized as follows: 1. The mother-infant interaction score was 59.79 points in intervention group and 53.91 points in control group. The mother-infant interaction score of intervention group showed significant difference than control group. Therefore, hypothesis 1 was supported. 2. The infant behavior score of intervention group was significantly higher than control group, but partially. Therefore, hypothesis 2 was partially supported. 1) The social interaction(orientation) score was 46.58 points in intervention group and 43.50 points in control group. The orientation score of intervention group showed significant difference than control group. 2) The state regulation score was 26.79 points in intervention group and 25.33 points in control group. The state regulation score of intervention group showed significant difference than control group. In conclusion, present work demonstrated that maternal education using NBAS is an effective intervention method for promotion of mother-infant interaction and of infant behavior development. Author believes that many inexperience young mother may find NBAS-based maternal education beneficial for their nursing babies, therefore NBAS-based intervention is recommended to be adopted routinely as an integral part of neonatal nursing strategies.

• 한국환경교육학회지:환경교육
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• 제15권1호
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• pp.68-82
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• 2002

My responses to Kim Kyung-Ok's Critique on my critique on the Hungerford approach can be summarized as follows; First, it was argued that possible confusions and misunderstandings around the concept of behavior in REB were mainly caused by Hungerford himself who has used the word in several different ways, from a bunch of overt actions to almost all kinds of responses including cognitive skills, without any clear operational definition of it for more than 20 years. It seems to be needed for future users of the word, 'Behavior' to Prevent unnecessary confusions by providing their operational definition of it. Second, REB is too ambiguous to be a legitimate goal of environmental education and too outcome-oriented to be a meaningful measure for environmental education research. Anyone who accept REB as a goal of EE or a measure for research should clearly suggest procedures and criteria for judging the environmental responsibility of actions under consideration. Third, the Hungerford approach has begun by realizing the limit of a linear traditional behavior change system and has been evolving toward a complex model with dynamic interactions among/between cognitive variables and affective variables. However, it still has one-way structural orientation toward 'Behavior' with no feedbacks. Addition of some feedback processes would make the model more flexible and realistic. Finally, both the Hines model and the Hungeford model were established based on a series of behavioristic studies including three doctoral dissertations equiped with a list of actions which were prejudged to be environmentally responsible by the researchers, not by the learners. What they were primarily interested in was not how mind functions during the learning processes but how learners' behavior can be effectively changed. Considering uncertainty and complexity associated with environmental problems, a great deal of efforts ought to be made toward more context-based and less normative studies applying cognitive psychology and quantitative approaches.

• 대한전자공학회논문지
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• 제13권6호
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• pp.7-11
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• 1976

연산증폭기를 이용한 전압안정부저항회로를 제안하였으며, 전입력전압범위에 걸쳐서 회로를 해석하였다. 부저항영역에서 이 v-i특성이 2가지 구분된 요인에 의해서 이루어짐을 밝혔고, 이 개념에 의해서 역 v-i특성의 꼭지점을 해석하였다. 제안된 회로를 실험하여 얻은 입력 v-i특성의 직선성은 대단히 양호하였으며, 이들의 부저항치는 전압범위 ±1∼±5V에서 -86∼833Ω였다. 그리고 전입력전압범위에서 v-i특성을 검토했다. A voltage-stable negative resistance circuit with operational amplifier is proposed, and circuit analysis is given all the input voltage range. The behavior of the v-i characteristics in the nogative resistance region is devided into two causes, and top points in the input v-i characteristics of the circuit is analyzed with them. Experimental results of the v-i characteristics of the proposed circuit has a good linearity in the negative region with negative resistance, -86Ω∼-833Ω for the input voltage, ± 1∼± 5 colts. The v-i characteristics of the circuit in all the input voltage range is discussed.

• 소성∙가공
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• 제18권2호
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• pp.156-159
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• 2009

Slot coating has been wide spread in photo-resist coating on the glass for liquid crystal display. Die in slot coater consists of manifold and land. Material comes in inlet of the die and flow into the manifold and then flow out through the land. The coating thickness variations along the die length depend upon inside of die design such as manifold and die land. However the coating thickness variations along the moving direction(coating direction) of the coater depend upon the operational conditions of coater as well as die lip design. The coating behaviors including atmospheric air have been investigated in this study. Die geometries considered in this study were nozzle gap and length of the die lip. Coating gap and coating speed were the variables fur coating operational conditions. When the nozzle gap and length of die lip increased climbing effect of PR on the downstream die lip was reduced. Subsequently uniformity of coating thickness improved. Uniformity of coating thickness also enhanced as coating gap and coater speed increased. The uniformity of coating gap was related to the velocity vector distributions on the coating surface.