• 충청수학회지
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• 제27권4호
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• pp.563-569
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• 2014

We investigate a minimal set of generators of a homogeneous ideal of a curve of degree d on a linearly normal smooth surface scroll W in $P^r$ whose arithmetic genus is maximal among curves of degree d on W.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.1039-1042
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• 2007

Motion blur of LCD displays has been measured subjectively by using Gabor patch radiusese. Gabor radiuses at a normalized scroll speed, Scroll speed times Fc, to be unity, indicate motion blur strengths, which are named a perceived motion blur strength measured by a Gabor patch. The results are compared with eye perception, PBET and EBET.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2069-2071
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• 2001

In this paper, a transmitter and a receiver using two identical Hyper-Chaos that n-double scroll circuits are proposed and a hyper-chaos synchronizations are investigated. we are proposed unidirectional coupling of ide n-double scroll cell for hyper-chaos synchronizat. We've shown that simulation result is synchronization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2072-2074
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• 2001

In this paper, a transmitter and a receiver using two identical Hyper-Chaos that n-double scroll circuits are proposed and a hyper-chaos synchronizations and secure communication are investigated. we are proposed unidirectional coupling of identical n-double scroll cell for hyper-chaos synchronization. We've shown that simulation result is synchronization and secure communication.

• 컴퓨터교육학회논문지
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• 제5권4호
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• pp.134-145
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• 2002

본 연구는 학습자가 전자교과서에서 문자별로 초점이 다른 텍스트요인을 학습시 내용흐름에 따라 편하게 읽을 수 있게 하기 위한 기능 및 기술적 방안을 제시한다. 본 연구에서 제시한 전자교과서의 텍스트 화면은 학습자가 전자교과서의 텍스트를 접할 때 설정된 값 이상의 데이터가 디스플레이 되면 마우스나 키보드의 작동 없이 학습자별로 원하는 형태로 자동으로 스크롤되어 쉽게 읽을 수 있게 된다. 또한 학습내용이나 개인차에 따라 제시방법이나 속도를 수시로 제어할 수 있다. 자동 텍스트 스크롤은 텍스트 내용구조(특정 및 영역 분류 등), 제시형태(밀도, 사이즈, 폰트 등), 제시방법(스크롤방법, 속도 등), 프로그램 통제유형(램 상주 등)과 화면디자인 적용(가독성 등)등에 따른 데이터 및 화면의 자동 스크롤 방법으로 텍스트 학습에 대한 개인의 능력 및 성향을 반영할 수 있다. 이를 위한 기술적 해결책을 환경설정단계, 스크롤지정단계, 복사단계, 데이터분석단계, 스크롤코딩단계, 중앙포커스코딩단계, 좌우포커스코딩단계, 실행단계로 나누어 제시하였다.

• 한국유체기계학회 논문집
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• 제3권1호
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• pp.19-27
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• 2000

A numerical study is presented for analysis of three-dimensional incompressible turbulent flows in a multi-blade centrifugal fan. Reynolds-averaged Navier-Stokes equations with a standard $k-{\espilon}$ turbulence model are discretized with finite volume approximations. The computational area is divided into three blocks; inlet core, impeller and scroll parts, which are linked by a multi-block method. The flow inside of the fan is regarded as steady flow, and the mathematical models for the impeller forces were established from a cascade theory and measured data. Empirical coefficients are obtained comparing between computational and experimental results for the case without scroll, and are employed to simulate the flow through the impeller with scroll. In comparisons with experimental data, the validity of the mathematical models for the impeller forces was examined. The characteristics of the flow in the scroll were also discussed.

• 에너지공학
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• 제21권4호
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• pp.398-401
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• 2012

본 연구에서는 자동차용 엔진 폐열 회수 유기랭킨사이클에 적용하기 위해 개발 중인 스크롤 팽창기의 효율을 상용 스크롤 팽창기와 비교 분석을 수행하였다. 팽창기 효율 특성 시험을 위해 유기랭킨사이클을 운전하면서 팽창기 출력, 팽창기 입구 온도, 압력 및 작동유체(냉매 R134a)의 유량을 측정하였으며, 개발 중인 스크롤 팽창기의 전효율은 상용 스크롤 팽창기의 전효율에 비해 매우 낮은 수준을 나타내었다. 특히 팽창기 내부의 작동유체 누설에 의한 체적효율 저하가 전효율 저하에 큰 영향을 주는 것으로 파악되었기 때문에 향후 팽창기 효율 향상을 위해 팽창기 내부의 누설문제를 필히 해결해야할 것으로 분석되었다.

• 설비공학논문집
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• 제7권3호
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• pp.366-381
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• 1995

A performance analysis of refrigeration system using the HFC-134a and scroll compressor is performed numerically. The refrigeration system mainly consists of various standard components such as heat exchanger, compressor, and expansion device. The model for heat exchanger performance is based on a tube-by-tube method which is analyzed separately by considering the cross-flow heat transfer with the outdoor air flow and pressure drop. Compressor is used the scroll-type compressor which has many merits such as high efficiency, low noise and vibration, and small in size. Short-tube is included as an expansion device. Vapour and liquid line are also considered for the performance analysis of refrigeration system. Using the modeling of various components of refrigeration system, a performance comparison of CFC-12 and HFC-134a is performed numerically for the various outdoor air temperature and various values of short-tube diameter. As the results of this study, the refrigeration system performance decreases as the outdoor air temperature increases. And the optimum short-tube diameter based on COP is 1.37mm for this system.

• 설비공학논문집
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• 제23권12호
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• pp.776-781
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• 2011

The rapid increases in global energy demand and global warming need renewable energy sources such as solar thermal energy, biomass energy and waste heat. A ORC-based micro-CHP system(< 10 kWe) is one of the effective means to use renewable energy and solve energy problems because of its compactness, flexibilities and lower cost compared to other systems. The most important core components of the ORC is the expander which has a strong effect on the cycle efficiency. In the range of power output from 1 to 10 kW, the scroll expander is a good choice due to its performance and reliability. In this study, we have carried out an experimental study on an ORC equipped with oil-free scroll expander working with refrigerant R134a. We have measured power output and thermal efficiencies of the ORC and analyzed correlation between volumetric efficiencies of the expander and thermal efficiencies of the ORC.

• 한국태양에너지학회 논문집
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• 제34권3호
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• pp.42-48
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• 2014

An experimental study was performed estimating COP(Coefficient of Performance) of air-conditioning cycle with inverter scroll compressor. All experiments were done for various compressor speeds from 1000~4000 rpm and used the inverter controller called CANDy to change the compressor rpm. The air-conditioning cycle components in the apparatus were used as same with components of YF hybrid car. To estimate the COP, this study measured the temperature and pressure at inlets and outlets of compressor, condenser, and evaporator. And also measured the compressor input power using Powermeter. Through the experiments, the maximum error to estimate COP was shown about ${\pm}6.09%$ at 3500rpm. This study revealed that the condenser temperature and pressure were increased and the evaporator temperature and pressure were decreased with the increased compressor speed. And also, the COP was decreased with increased compressor speed. Those results can be used the basic and fundamental data to design the air-conditioning cycle with inverter scroll compressor.