• 한국전자통신학회논문지
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• 제15권3호
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• pp.593-602
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• 2020

최근 스마트 팜에 대한 연구가 활발히 진행되면서 농작물을 효율적으로 재배하는 시스템들이 도입되고 있으며 에너지 절감을 위해 태양광, 지열, 풍력 발전과 같은 신재생에너지를 활용한 다양한 에너지 시스템들이 제안되고 있다. 본 논문에서는 에너지 자립도와 작물재배 환경 향상을 제공하는 농작물 대상 신재생에너지 융합 시스템을 제안한다. 먼저 ICT기반의 데이터 수집을 위한 LPWA 기반 통신 노드, 게이트웨이를 제시한 다음 통신노드를 통해 에너지 데이터, 농작물 생육 데이터, 환경 데이터를 수집하여 빅 데이터로 구축하여 농작물 재배 환경 특성을 반영한 최적의 에너지 관리를 수행하는 통합 모니터링 서버를 제안한다. 제안된 시스템은 신재생에너지와 스마트 팜의 융합을 통해 저비용, 고품질의 농작물 생산에 기여할 것으로 기대된다.

• 한국통신학회논문지
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• 제32권12C호
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• pp.1175-1187
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• 2007

이동통신 기지국 시스템에서 송신 신호의 PAR 성능을 (peak-to-average power ratio) 개선함으로써 범용 전력 증폭기의 사용이 가능하게 되며, 이로 인해 전체적인 기지국 비용의 절감을 기대할 수 있다. 일반적으로 PAR 값을 줄임으로 인해 기지국 송신신호의 인근 대역 간섭 제한 성능을 나타내는 ACLR이나 (adjacent channel leakage ratio) 품질을 나타내는 EVM이나 (error vector magnitude) PCDE 성능의 (peak code domain error) 열화를 발생시킨다. 본 논문에서 이러한 문제점을 해결하기 위하여 필터링 기반의 CFR 방식인 (crest factor reduction) FDCFR 알고리즘을 (filter-dependent CFR) 소개하며, 히스토그램 기반 코드 영역 보상(HBWCDC; histogram based waterfilling code domain compensation)기법을 제안한다. 본 논문에서 제안한 CFR 알고리즘은 PAR 감소뿐만 아니라 앞서 언급한 ACLR, EVM 및 PCDE등의 성능 열화를 방지한다.

• Nuclear Engineering and Technology
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• 제27권1호
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• pp.84-95
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• 1995

Application of computer software to safety-critical systems is on the increase. To be successful, the software must be designed and constructed to meet the functional and performance requirements of the system. For safety reason, the software must be demonstrated not only to meet these requirements, but also to operate safely as a component within the system. For longer-term cost consideration, the software must be designed and structured to ease future maintenance and modifications. This paper present a software engineering process for the production of safety-critical software for a nuclear power plant The presentation is expository in nature of a viable high quality safety-critical software development. It is based on the ideas of a rational design process and on the experience of the adaptation of such process in the production of the safety-critical software for the Shutdown System Number Two of Wolsong 2, 3 & 4 nuclear power generation plants. This process is significantly different from a conventional process in terms of rigorous software development phases and software design techniques. The process covers documentation, design, verification and testing using mathematically precise notations and highly reviewable tabular format to specify software requirements and software design. These specifications allow rigorous, stepwise verification of software design against software requirements, and code against software design using static analysis. The software engineering process described in this paper applies the principle of information-hiding decomposition in software design using a modular design technique so that when a change is' required or an error is detected, the affected scope can be readily and confidently located. It also facilitates a sense of high degree of confidence in the ‘correctness’ of the software production, and provides a relatively simple and straightforward code implementation effort.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.101-104
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity compared to ALD and PECVD methods. It is capable of reacting to the substrate by misting an aqueous solution using ultrasonic waves under vacuum-free conditions of atmospheric pressure. In particular, Ga₂O₃ is regarded as advanced power semiconductor material because of its high quality of transmittance, and excellent electrical conductivity through N-type doping. In this study, Computational Fluid Dynamics were used to predict the uniformity of the thin film on a large-area substrate. And also the deposition pattern and uniformity were analyzed using the flow velocity and particle tracking method. The uniformity was confirmed by quantifying the deposition cross section with an FIB-SEM, and the consistency of the uniformity prediction was secured through the analysis of the CFD distribution. With the analysis and experimental results, the match rate of deposition area was 80.14% and the match rate of deposition thickness was 55.32%. As the experimental and analysis results were consistent, it was confirmed that it is possible to predict the deposition thickness uniformity of Mist-CVD.

• 디자인학연구
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• 제5권1호
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• pp.7-20
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and recei\ulcornerves pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective fina\ulcornerncial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper de\ulcornervlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine bygeneralization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers aro~nd the country.

• 디자인학연구
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• 제5권1호
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• pp.21-36
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and receives pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective financial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper devlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine by generalization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers around the country.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.389-392
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• 2010

특수한 작업장이외의 주택실내나 일반 사무실 등에서의 공기오염 문제는 인간이 주거시설에 거주한 이례로 계속되어온 문제로서 그 대책이 시급하다. 쉽게 외부의 신선한 공기와 충분한 양의 환기로서 해결이 가능하나 사람이 계속해서 관리해 주기에는 불편한 상황이다. 네트워크상에서 센서 네트워크를 이용한다면 쉽게 관리 및 제어가 가능하다. 유비쿼터스 센서 네트워크는 부착된 태그와 센서로부터 사물 및 환경 정보를 감지, 저장, 가공, 전달하여 인간 생활에 폭넓게 활용되며, 환경오염에 대해서도 사람이 직접 측정 및 모니터링 하기 힘든 지역에 설치되어 활용되고 있다. 다른 네트워크에 비해 초소형, 저전력, 저비용으로 쉽게 구성 가능하기 때문에 꾸준히 연구되어지고 있으며 환경과 IT의 전략적 융합을 통한 그린 IT의 네트워크 접목 또한 중요한 연구분야로 조명되고 있다. 본 논문에서는 네트워크 기반하에 실내 공기질 관리를 구성하고 관리 및 제어하여 활용 방안에 대하여 제시한다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 춘계 종합학술대회 논문집
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• pp.241-260
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• 2004

무역포탈사이트는 중소기업들이 최신의 정보와 통신기술을 통해 효율적으로 국제무역활동을 할 수 있게 하는 도구중 하나라고 할 수 있다. 따라서 중소기업들의 수출경쟁력 제고를 위해서는 무역포탈사이트를 적극적으로 활용할 필요가 있다. 이와 관련하여 본 논문은 기존의 서비스품질에 관한 문헌과 정보기술 이용만족도에 관한 연구 검토를 통해 무역포탈사이트를 사용하는데 있어 이용자들의 만족 요인을 분석하였다. 실증 연구를 위해 서비스품질, 정부정책, 기술, 기업, 비용이 이용만족도에 영향을 미치고 이용만족도는 향후 지속적 이용의도에 영향을 미치는 것으로 연구모형을 설정하였다. 대표적인 무역포탈사이트 이용자들에 대한 실증분석 결과 서비스품질, 정부정책, 비용이 이용자 만족에 유의한 영향을 미치고, 이용자 이용만족은 지속적 사용의도에 유의적인 영향을 미치는 것으로 나타났다. 이러한 분석 결과는 기업의 무역포탈사이트 관리자, 전자무역시스템개발자, 정부정책자 등에게 여러 가지 시사점을 제공하고 있다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.467-470
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• 2010

유비쿼터스 센서 네트워크는 부착된 태그와 센서로부터 사물 및 환경 정보를 감지, 저장, 가공, 전달하여 인간 생활에 폭넓게 활용되며, 환경오염에 대해서도 사람이 직접 측정 및 모니터링 하기 힘든 지역에 설치되어 활용되고 있다. 기존 네트워크에 비해 초소형, 저전력, 저비용으로 쉽게 구성 가능하기 때문에 꾸준히 연구되어지고 있으며 환경과 IT의 전략적 융합을 통한 그린 IT의 네트워크 접목 또한 중요한 연구분야로 조명되고 있다. 본 논문에서는 네트워크 기반하에 실내 공기질 관리 센싱 메커니즘 구성도를 구현하고 환경요소를 측정하여 향후 환경 모니터링 시스템의 활용방안을 제안한다.