• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 추계학술대회 논문요약집
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• pp.102-102
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• 2003

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2000년도 추계총회 및 학술발표회
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• pp.51-51
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• 2000

• 방송공학회논문지
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• 제24권7호
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• pp.1246-1258
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• 2019

Since light field (LF) image has huge data volume, it requires high-performance compression technique for efficient transmission and storage of its data. Camera users may like to represent parts of image at different levels of focus at their choice anytime. To address this refocusing functionality, in this paper, we first render a focal stack consisting of multi-focus images, then compress it instead of original LF data. The proposed method has advantage of minimizing the amount of LF data to realize the targeted refocusing applications. Our experiment results show that the proposed method outperforms the state-of-the-art for LF image compression method.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 춘계학술발표대회
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• pp.795-798
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• 2007

RFID 리더기가 영역내의 다수의 태그를 인식하기 위해선 충돌방지 알고리즘이 필수적으로 요구된다. 본 논문은 Auto ID Class 0에서 정의한 충돌방지 알고리즘인 Bit-by-Bit 이진트리 알고리즘(BBB)의 충돌 위치를 스택에 저장하고 이를 통해 다음 질의어를 결정함으로써 성능이 크게 개선된 Stack-bit-by-bit(SBBB) 알고리즘을 제안한다. 시뮬레이션을 통한 검증결과 질의-응답 횟수, 질의어의 크기, 응답어의 크기의 모든 면에서 성능이 개선된 것을 확인할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1870-1872
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• 1999

Performance of 20-cell stack for direct methanol fuel cell (DMFC) was tested at constant temperature. Electrode evaluation used to the stack was tested by the performance of a single cell. A new composite electrode prepared from active carbon cloth and high porous active carbon was developed for hydrophilic layer of the cell. Characteristics of a single cell using the composite electrode showed the current density of $500mA/cm^2$ at the cell voltage of 0.4V at $120^{\circ}C$. For the operating of 20 days. the cell voltage at constant cell current densty of $100mA/cm^2$ was slightly reduced from 0.62V to 0.53V with the cell voltage decay rate of 14.5%. Power of 20-cell stack at 5.3V, $100^{\circ}C$ was about 180W.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.341-348
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• 2016

The experiments related on structure and water electrolysis performance of HALE UAV stack were conducted in this study. Anode catalyst $IrRuO_2$ was prepared by Adam's fusion methods as 2~3 nm nano sized particles, and the cathode catalyst was used as commercial product of Premetek. The MEA (membrane electrode assembly) was manufactured by decal methods, anode and anode catalytic layers were prepared by electro-spray. HALE stack was composed of 5 multi-cells as $0.2Nm^3/hr$ hydrogen production rate with hydrogen pressure as 10 bar. The water electrolysis performance was investigated at atmospheric pressure and temperature of $55^{\circ}C$. Best performance of HALE UAV stack was recorded as cell voltage efficiency as 86%.

• 전기학회논문지
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• 제59권6호
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• pp.1087-1094
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• 2010

We have developed a cylindrical multi-terminal capacitive-conductive sensor that could be attached to the internal surface of cooling system pipe to evaluate capacitance and conductivity of heat transfer fluid. It was used as measuring system to diagnose insulating condition, by which was kept a insulating resistance of inner stack and at the same time was cooled electrochemical heat of reaction of FCEV(fuel cell electric vehicle) stack that used a compressed hydrogen gas reacting with oxygen in accordance with variation on thermal degradation of nonconductive heat transfer fluid. Also to assess diagnosis characteristics of heat transfer fluid, i.e. coolant, we have performed accelerated aging test using developed sensor attached to cooling system. Consequently, it was measured dielectric and electric resistance of coolant to estimate and analyse for dielectric properties by degradation condition.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.18-38
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• 2017

Infrastructure-as-a-Service (IaaS) clouds provide infrastructure as a pool of virtual resources, and the public IaaS clouds, e.g. Amazon Web Service (AWS) and private IaaS cloud toolkits, e.g. OpenStack, CloudStack, etc. provide their own application programming interfaces (APIs) for managing the cloud resources they offer. The heterogeneity of the APIs, however, makes it difficult to access and use the multiple cloud services concurrently and collectively. In this paper, we explore previous efforts to solve this problem and present our own implementation of an integrated cloud API, which can make it possible to access and use multiple clouds collectively in a uniform way. The implemented API provides a RESTful access and hides underlying cloud infrastructures from users or applications. We show the implementation details of the integrated API and performance evaluation of it comparing the proprietary APIs based on our cloud testbed. From the evaluation results, we could conclude that the overhead imposed by our interface is negligibly small and can be successfully used for multi-cloud access.

• 설비공학논문집
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• 제23권2호
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• pp.153-163
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• 2011

Energy efficiency and indoor air quality have become main issue to develop healthy and sustainable building in these days. As an effort to reduce the energy consumption in multi-residential building, many attempts as like passive design strategies and renewable energy as well as active control method are tried. However, underground parking lot in multi-residential building seldom adopt the sustainable strategies and only mechanical system is installed as usual. Moreover, the mechanical system installed in underground parking lot is rarely operated due to the electric demand for operation after completion. In this study, as an energy efficient measure, natural ventilation system using stack effect as a driving force for underground parking lot will be proposed and the performance of the suggested system will be analyzed by simulation method.

• Journal of Information Processing Systems
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• 제8권3호
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• pp.471-482
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• 2012

For disaster exploration and surveillance application, this paper aims to present a novel application of a multi-robot agent based on WSN and to evaluate a multi-hop communication caused by the robotics correspondingly, which are used in the uncertain and unknown subterranean tunnel. A Primary-Scout Multi-Robot System (PS-MRS) was proposed. A chain topology in a subterranean environment was implemented using a trimmed ZigBee2006 protocol stack to build the multi-hop communication network. The ZigBee IC-CC2530 modular circuit was adapted by mounting it on the PS-MRS. A physical experiment based on the strategy of PS-MRS was used in this paper to evaluate the efficiency of multi-hop communication and to realize the delivery of data packets in an unknown and uncertain underground laboratory environment.