• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.647-655
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• 2021

The IMO (International Maritime Organization) is discussing the improvement of energy ef iciency of ships in order to reduce greenhouse gas emissions from ships. Currently, by applying an ORC power generation system using waste heat generated from ships, high energy conversion efficiency can be expected from ships. This technology uses an organic medium based on Freon or hydrocarbons as the working fluid, which evaporates at a lower temperature range than water. Through this, it is possible to generate steam (gas) and generate power at a low and low temperature relatively. In this study, the analysis of heat flow between the refrigerant and waste heat in the ORC power generation system, which is an organic Rankine cycle, is analyzed using 3D simulation techniques to determine the temperature change, velocity change, pressure change, and mass change of the fluid flowing of the WHRU (Waste Heat Recovery Unit) inside and the outside the structure. The purpose of this study is to analyze how the mass change affects the structure, and this study analyzed the heat transfer of the heat exchanger from the refrigerant and the exhaust gas of the ship's main engine in the ORC power generation system using this technique.

• Journal of Environmental Science International
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• v.32 no.1
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• pp.47-55
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• 2023

This study evaluated the biochemical methane potential (BMP) of primary sludge, secondary sludge, and food waste in batch anaerobic mono-digestion tests, and investigated the effects of mixture ratio of those organic wastes on methane yield and production rate in batch anaerobic co-digestion tests, that were designed based on a simplex mixture design method. The BMP of primary sludge, secondary sludge and food waste were determined as 234.2, 172.7, and 379.1 mL CH₄/g COD, respectively. The relationships between the mixing ratio of those organic wastes with methane yield and methane production rate were successfully expressed in special cubic models. Both methane yield and methane production rate were estimated as higher when the mixture ratio of food waste was higher. At a mixing ratio of 0.5 and 0.5 for primary sludge and food waste, the methane yield of 297.9 mL CH₄/g COD was expected; this was 19.4% higher than that obtained at a mixing ratio of 0.3333, 0.3333 and 0.3333 for primary sludge, secondary sludge, and food waste (249.5 mL CH₄/g COD). These findings could be useful when designing field-scale anaerobic digersters for mono- and co-digestion of sewage sludges and food waste.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.51-57
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• 2009

Ubiquitous sensor network is the communication environment where sensor nodes move freely and construct network to get the services from the system. So, it does not need fixed infrastructure and can easily be placed in unaccessible regions like war or calamity area. Wireless sensor network protocol has self-organizing capability, need to adapt topology change flexibly and also has technique that sensor nodes work cooperatively, because network disconnection is frequently occurred due to the active mobility of sensor nodes. In this paper, we design a cluster based fault-tolerant routing protocol for the efficient topology construction and to guarantee stable data transmission in USN. The performance of the proposed protocol is evaluated by an analytic model.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.122-124
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• 2012

최근 지식정보화 시대의 집단지성기반 교육 패러다임 변화는 큰 이슈로 떠오르고 있다. 특히 융합적 학문을 근원으로 창의성 계발과 아이디어를 중요시하고 있으며, 창조적 교육방식을 지향하고 있다. 그러나 다양한 영역에 지식전문가들과 학습자들 간에 지식을 공유하기 위한 플랫폼 공간이 제대로 제공되고 있지 못하며, 단순한 컨텐츠 제공을 목적으로 이러닝 서비스가 일부 제공되고 있는 것이 현실이다. 따라서 본 논문에서는 집단지성을 기반으로 지능형 튜터링 에이전트 시스템 설계를 제안하고, 새로운 에이전트(Agent) 개념을 통해 지식인들과 학습자들 간에 지식을 공유할 수 있을 뿐만 아니라 새로운 지식을 창출하고, 관리 및 유통할 수 있는 구조를 연구하였다. 또한 사용자들로부터 발생하는 데이터와 정보들을 자동 분석하여 지능적으로 학습상황에 대처할 수 있도록 설계하였으며, 튜터(Tutor)와 튜티(Tutee)간에 협력적인 학습 생태계가 형성될 수 있도록 하였다. 따라서 본 연구의 결과를 기반으로 미래 스마트 학습 플랫폼 발전에 많은 도움이 되길 기대한다.

• The Magazine of the IEIE
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• v.37 no.12
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• pp.144-153
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• 2010

지금은 국내외 위성 영상자료의 증가가 예상되고 위성 정보 활용 관련 산업 및 시장에 대한 전망은 충분히 발전 가능성이 있다고 예측되고 있어, 이에 대한 대응 방안을 마련해야할 시점이다. 특히 이전의 단순 영상 제공에서 가공, 처리를 통한 부가 서비스에 대한 부분이 중요시 될 것으로 사료된다. 앞으로 우리가 나아가야 할 길은 국내 위성 정보 활용 시장 확대 및 국제적인 경쟁력을 갖추는 것이다. 이를 위해서는 무엇보다 위성정보 활용 범국가 활용체계 구축이 시급하며, 국가 컨트롤 타워를 통하여 위성정보 활용 중장기 계획을 수렴하여 체계적인 계획 실천이 필요하다. 또한 표준화된 위성정보 자료처리 및 배포 시스템 구축, 그리고 위성정보 활용의 활성화를 위한 인프라 구축에 많은 관심을 두어야한다. 하지만 무엇보다 세계 위성영상 상용화 시장에 경쟁력을 가지기 위해서는 핵심 및 융복합 활용 기술 개발, 국내 전문 인력/전문기업 양성 및 국제적 협력 강화가 중요하다. 최근 국내 위성개발 위상 강화로 인하여, IC 가입이 추진되고 있으며 이사회 회의를 통하여 회원기관으로 한국항공우주연구원이 동의를 받은 상태이다. 이는 대한한국 위성정보의 활용이 경제적인 측면에서 뿐만 아니라, 범지구적 문제해결에 이바지 할 수 있는 위성정보 공여국의 위치로 진입하였다는 점을 암시하는 것이라 할 수 있다.

• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.197-217
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• 2003

ebXML(Electronic Business XML) is a global eBusiness framework standard which provides solutions to interoperability problem between heterogeneous eBusiness systems. ebXML framework includes Business Process Specification, Core Components, Registry/Repository and Messaging Service as its major components. Based on this framework, ebXML business transactions are executed by exchanging appropriate business documents as specified in Business Process Specification. And required business documents are generated by assembling Core Components at the Business Process design time. In this paper, we present technical architecture of ebXML framework and Core Component technology, and then explain design and implementation issues of ebXML business document generation tool.

• The Journal of Korean Association of Computer Education
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• v.5 no.2
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• pp.39-48
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• 2002

It is general that the ICAI(Intelligent Computer Assisted Instruction) consists of 4 modules. Export module, Teacher module, Student module and Interface module. In each module construction, there should be some rules to control strategies efficiently and systematically that are related to the texts and assessment instruments, assessment results and evaluation, feedback, etc. It is necessary to use a method to classify the curriculum into sections with units and to represent the identified relationships between them. These relationships are available to all the process of learning, assessment, evaluation and feedback. In this paper, we propose the method to represent these units and relationships as a graph. In addition, we implement an internet-based courseware authoring tool to support the environment in which several expert can construct concurrently the courseware with cooperation between them.

• Korean Journal of Childcare and Education
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• v.16 no.1
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• pp.1-20
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• 2020

Objective: The purpose of this study was to explore the application of the multidisciplinary model, which is customized evidence-based counseling for abused preschool children done by a day care center teacher. Methods: The participants were 16 preschool children which were abused by a day care center teacher and their parents. The data were analyzed by using the Wilcoxon Signed-rank test. Results: The multidisciplinary cooperative service model based on customized evidence-based counseling for abused preschool children, their parents, and day care center teachers was developed. Based on this model, customized evidence-based Post-Traumatic Stress Disorder (PTSD) emergency intervention was provided to preschool children abused by a day care teacher in Incheon. The multidisciplinary cooperative emergency intervention service proved to be effective in reducing emotional and behavioral problems of abused preschool children and enhancing the mental health of parents. Conclusion/Implications: The results of this study indicated that the customized evidence-based counseling for abused preschool children done by a day care center teacher using the multidisciplinary cooperative linkage system would be effective, and that child abuse prevention by day care center teachers and intervention services should be provided systematically at the national level.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.771-778
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• 2014

We propose Femto-cell power control scheme in HeNet with Game Theory. The Femto-cell which provide high quality with low power is issued by many benefits, however there is a bunch of interferences when many Femto-cells use overlapped bandwidth with Macro-cell. We defined base station of cellular networks and mobile users as players of Game Theory, and configured interference effect among each other as power utility function. Futhermore, we showed enhanced overall system performance, lower power usage and interference decrease by using optimal power.

• Journal of Platform Technology
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• v.6 no.3
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• pp.31-37
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• 2018

Recently, the platforms for open science are being developed for helping researchers and scientists who are interested in convergence studies. This paper is focused on deriving a design method for an integrated architecture for knowledge infrastructure in science and technology and to set up the integration level of details and association between data and services in the integrated architecture. To facilitate the open science in research lifecycle, reconstructing individual services into modular and independent function blocks needs to be reusable and interoperable. The proposed design methodology is used for manipulating a service integration for the convergence service of S&T(Science and Technology) knowledge infrastructure. It can support to seamlessly access computing resources and the research results including artifacts digitally enabled scholars, researchers, and engineers participating in multidisciplinary collaborations.