• Journal of Electrical Engineering and Technology
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• 제1권1호
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• pp.28-34
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• 2006

Recently, in accordance with the development of IT technology, it is prevalent for power quality monitors to be connected to each other via networks and share their data because such networks provide system-wide insights to customers concerning power quality. Those systems can alarm and display power quality events for the convenience of customers. However, if a power quality event occurs, it is difficult for customers to determine its cause and solution because the systems do not provide appropriate power quality diagnosis functions. The power quality management system presented in this paper has been developed to provide customers with various power quality diagnosis functions so that they can cope well with power quality problems with the right measure in the right place. This paper presents the structure and functions of the developed power quality management system and shows some results of the power diagnosis functions.

• 한국물환경학회지
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• 제21권6호
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• pp.617-623
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• 2005

Forestry and agricultural land uses constitute 85% of Korea and these land uses are typically mixed in many watersheds. Biological Oxygen Demand (BOD) concentration is a primary factor for managing water qualities of the water resources in Korea. BOD loadings from diffuse sources, however, not well monitored yet. This study aims to assess BOD loadings from diffuse sources and their affecting factors to conserve quality of water resources. Event Mean Concentration (EMC) of BOD was calculated based on the monitoring data of forty rainfall events at four agricultural-forestry watersheds. Exceedence cumulative probability of BOD EMCs were plotted to show agricultural activities in a watershed impacts on the magnitude of EMCs. Prediction equation for each rainfall event was proposed to estimate BOD EMCs: $EMC_{BOD}(mg/L)=EXP(0.413+0.0000001157{\times}$(discharged runoff volume in $m^3$)+0.018${\times}$(ratio of agricultural land use to total watershed area).

• 품질경영학회지
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• 제19권2호
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• pp.96-107
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• 1991

At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.233-242
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• 2014

A magnetically levitated vehicle (Maglev) system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a train operation plan and service quality considering traffic waves. We propose a method and model to simulate Maglev operation considering continuous demand changes. For this purpose, we employed a discrete event model that is suitable for modeling the behavior of railway passenger transportation. We modeled the system hierarchically using discrete event system specification (DEVS) formalism. In addition, through implementation and an experiment using the DEVSim++ simulation environment, we tested the feasibility of the proposed model. Our experimental results also verified that our demand-driven simulation technology can be used for a priori review of train operation plans and strategies.

• 한국조리학회지
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• 제23권8호
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• pp.40-53
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• 2017

This study identified the important service quality of the emerging night market as an alternative for the revitalization of the traditional market. This study also was to analyze the effects of service quality on customers' emotions, behavior intention and local performance in night market, and to provide an effective operation plan. The collected data were analyzed by frequency analysis, factor analysis, reliability analysis and multiple regression analysis using SPSS 16.0 Version, a statistical package program, and various results were discovered. First, all the service quality factors (convenience, food, event program, physical environment) had a positive (+) effect on positive emotion, and the service quality factors except event program had a negative (-) effect on negative emotions. Second, the service quality factors had a partially positive (+) effect on behavior intention and local performance. Third, the positive and negative emotions had a effect on behavior intention, however, the positive emotions had a positive (+) effect on local performance. Consequently, the present study confirmed that service quality in the night market is important factors for emotions, behavior intention, and local performance. Therefore, the findings of this study is capable of being the basic data for revitalizing the traditional market in the future.

• 무역학회지
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• 제47권3호
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• pp.93-110
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• 2022

This study aims to develop online convention service quality and examine the effect of online convention service quality on re-participation intention in the same convention and other types of online conventions. Based on an extensive literature review, the study chose five main factors of online convention service quality: human service, program service, platform service, platform aesthetics, and interaction. A total of 284 data were collected from online convention participants from July 26 to August 6, 2021. For the hypotheses test, multiple regression analysis was used. As a result, interaction and program service quality had positive effects on re-participation intention in the same convention, but except for platform aesthetic, all factors positively affected re-participation intention in other types of online conventions. This study also found that online service quality factors are more helpful in predicting the intention of re-participation in other types of online conventions rather than re-participation in the same convention. Based on the results, theoretical and practical implications were discussed

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
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• pp.422-428
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• 2005

본 논문에서는 멀티미디어 콘텐츠의 프리젠테이션 품질을 유지하기 위해 멀티미디어 콘텐츠를 처리할 때 발생하는 여러 사건들을 이벤트(event)로 정의하고, 각각의 특징에 따라 여러개의 클래스로 분류하였다. 그리고 이벤트의 처리와 관리에 의해 프리젠테이션 동기화를 처리할 수 있는 모델을 제안하였다. 또한, 쇼(show) 진행에 관련된 실행모듈, 스레드(thread) 등이 이벤트를 이용하여 상호 통신함으로써 프리젠테이션 서비스를 유지하는 방안에 대해 제안하였다. 특히, 제안된 모델에서는 사용자 인터페이스를 통해 사용자가 프리젠테이션 수행에 직접적으로 개입할 수 있을 뿐만 아니라 서비스 과정에서 발생하는 예측 불가능한 상태 변화에 대하여 능동적으로 대처함으로써 멀티미디어 문서의 프리젠테이션 품질을 유지할 수 있도록 하였다.

• 정보처리학회논문지B
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• 제9B권5호
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• pp.549-554
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• 2002

본 논문에서는 인터넷 기반 멀티미디어 응용 서비스가 요구하는 상호운용성과 사용자에게 높은 품질의 서비스를 지원할 수 있는 UQoS 관리 (UQoSM : User Quality of Service Management) 미들웨어 프레임워크를 제안한다. UQoS 관리 미들웨어 시스템은 멀티미디어 응용 시스템들의 사용자 요구사항들을 지원하기 위해 기존의 이벤트 서비스 모델에 리플렉션(reflection) 기법을 적용하여 이벤트 모니터, 리플렉티브 이벤트 필터링, 실시간 관리 등의 컴포넌트를 포함하는 구조를 가진다. 특히, 본 논문에서는 인터넷 기반 멀티미디어 응용 서비스 사용자의 다양한 요구 사항을 지원할 수 있는 리플렉티브 이벤트 필터링을 제공하는 것에 중점을 두었다. 이로써 사용자는 보다 높은 서비스를 제공받게 되고 이 과정을 통해 전체적인 네트워크 트래픽이 감소되는 효과를 얻을 수 있다.

• 대한간호학회지
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• 제44권5호
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• pp.515-524
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• 2014

Purpose: The purpose of this study was to identify whether the couple perceived breast cancer as a traumatic event, to evaluate the association among posttraumatic growth, dyadic adjustment, and quality of life and to explore the predictors affecting quality of life of the couple. Methods: A cross-sectional comparative survey design was utilized. Participants were 57 couples recruited from a national cancer center in Korea. Data were analyzed using paired t-test, McNemar test and independent t-test. On the basis of variables found to be significantly associated with quality of life, multiple regression was used to examine the simultaneous influence of multiple predictors. Results: Breast cancers survivors and spouses perceived breast cancer as a traumatic event (43.9% and 24.6%, respectively). The global quality of life was explained by perception as trauma (${\beta}$= -19.79) and posttraumatic growth (${\beta}$=0.46) in survivors, and perception as trauma (${\beta}$= -18.81) and dyadic adjustment (${\beta}$=0.53) in spouses. Conclusion: Results suggest that future research should use qualitative methods to evaluate why contemplating reasons for cancer contributed to posttraumatic growth, examine other potential predictors of quality of life such as dyadic adjustment and intimacy, and identify links between posttraumatic growth and other psychological outcomes such as distress and well-being, using prospective analyses.

• 전기학회논문지
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• 제61권5호
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• pp.657-663
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• 2012

Recently, by increasing of devices which are sensitive to power quality, the deterioration of power quality has been accelerated. For this reason, the social and economic losses are increased. So not only correct measurement and evaluation, but also countermeasure for improvement of power quality is surely necessary for both electric power supplier and consumer. In this paper, the discrimination algorithm for events and variation occurred in distribution systems using S-transform is proposed. Firstly, we review for events and variations that occur in distribution system. Next, we simulate events and variations on various conditions using ElectroMagnetic Transient Program(EMTP). For the simulation, the IEEE 13 Node Test Feeder and KEPCO's distribution system is modeled. Finally, for the analysis, a modified wavelet transform known as S-transform is adopted to find out the characteristics of each events and variations.