• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.443-445
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• 2008

We have fabricated vertical type organic thin film transistor using $C_{60}$ as a n-type active material to improve the problems of conventional OTFTs. In general, it can be argued that the characteristics of organic transistor were influenced by carrier mobility and density. We have used several kinds of metals as source and gate electrodes to optimize the device characteristics using $C_{60}$. In addition, we have examined the feasibility of fabrication of organic light-emitting transistor (OLET) using MEH-PPV as an emission layer.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 봄 학술발표회 논문집
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• pp.56-60
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• 1991

Free Cantilever Method(FCM) is one of the most effective construction methods when precast prestressed concrete box girders are erected in the construction site. The special feature of FCM is that precast segments are erected in cantilever on the pier and connected in the middle of span to form the complete superstructure. Therefore each structural subsystem will be shown in each construction step and it should be analyzed for design whenever the segment is erected. In this study, the computer program was developed to optimally design the P.C box girder bridge considering tile construction sequence and verified by comparing the calculated results with the data of existing P.C box girder bridges. the sensitivity analysis was performed to show the efficiency of the developed program.

• 한국컴퓨터정보학회논문지
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• 제22권3호
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• pp.81-88
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• 2017

In this paper, we classified the weaknesses of C/C++ programs listed in CWE based on the diagnostic information produced at each stage of program compilation. Our classification identifies which stages should be responsible for analyzing the weaknesses. We also present algorithmic frameworks for detecting typical weaknesses belonging to the classes to demonstrate validness of our scheme. For the weaknesses that cannot be analyzed by using the diagnostic information, we separated them as a group that are often detectable by the analyses that simulate program execution, for instance, symbolic execution and abstract interpretation. We expect that classification of weaknesses, and diagnostic information accordingly, would contribute to systematic development of static analyzers that minimizes false positives and negatives.

• Animal cells and systems
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• 제2권3호
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• pp.351-353
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• 1998

A 245 bp segment of E. coli chromosomal replication origin, oriC, contains 11 repeats of the GATC sequence in which adenine is methylated by Dam methylase. Newly replicated oriC is hemimethylated. The parental strand of the newly replicated oriC is methylated, but the nascent strand is not yet methylated until methylated by Dam methylase. The hemimethylated oriC plays an important role in the regulation of chromosomal replication. Activity in the seqA mutant was identified to bind preferentially to hemimethylated DNA, but not to fully-methylated DNA. This activity may participate in the sequestration of initiation of chromosomal replication.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.167-170
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• 2002

In this paper, we implement a 2.4 kbps STC speech codec using the TMS320C6201 DSP The main job for this work is twofold: one is to convert floating-point operation in the codec into fixed-point operation while maintaining the high resolution, and the other is to optimize the program to make it run in real time with memory size as small as possible. The implemented decoder uses 54.8 kbyte of program memory, 29.7 kbyte of data ROM and 55.2 kbyte of data RAM, respectively. It also uses about 45% of maximum computation capacity of TMS320C6201.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.481-482
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• 2013

This paper presents the method to determine the battery capacity for controlling the wind power with BESS for stabilizing the output of HanGeong wind farm in accordance with grid codes for distributed generators in Jeju Island. To find appropriate capacity of BESS, three kinds of simulations are carried out : There are focused on smoothing control, the frequency fluctuation and the renewable energy resources standards, respectively. As the simulation result, maximum C-rates of BESS for the wind farm are calculated as 2C, 5C and 2C that are for each method and battery capacities have 25%, 20% and 10% of total capacity of HanGeong wind farm. Finally, simulations for this paper are carried out by using PSCAD/EMTDC.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.545-547
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• 2019

Policy Gradient 방식의 학습은 최근 강화학습 분야에서 많이 연구되고 있는 주제로, 본 논문에서는 강화학습을 적용시킬 수 있는 OpenAi Gym 의 'CartPole-v0' 와 'Pendulum-v0' 환경에서 Policy Gradient 방식의 Asynchronous Advantage Actor-Critic (A3C) 알고리즘과 Proximal Policy Optimization (PPO) 알고리즘의 학습 성능을 비교 분석한 결과를 제시한다. 딥러닝 모델 등 두 알고리즘이 동일하게 지닐 수 있는 조건들은 가능한 동일하게 맞추면서 Episode 진행에 따른 Score 변화 과정을 실험하였다. 본 실험을 통해서 두 가지 서로 다른 환경에서 PPO 가 A3C 보다 더 나은 성능을 보임을 확인하였다.

• 대한금속재료학회지
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• 제50권6호
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• pp.445-448
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• 2012

We studied the effect of temperature and reaction time by investigating the various temperatures and reaction times in the reduction of molybdenum oxide ($MoO_3$) to molybdenum (Mo) powder in hydrogen gas. We also studied the effect of the reaction of reduction according to the various hydrogen gas flow rates. We surveyed the reduction from molybdenum oxide to molybdenum powder in hydrogen gas and checked two temperature ranges, one from $400^{\circ}C$ to $600^{\circ}C$ and the other from $700^{\circ}C$ to $900^{\circ}C$. We found that the reaction ratio of molybdenum oxide increased with an increasing temperature and also increased with an increasing reaction time, but hydrogen gas did not influence the reduction ratio of molybdenum oxide. We examined molybdenum powders fabricated by ball milling for two hours, using with X-ray diffraction (XRD) and a scanning electron microscopy (SEM).

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.69-76
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• 2005

The performance of water-to-water heat pump system coupled with the ground source vertical heat exchanger is presented in this paper. The CAP program of Florida Heat Pump Co. is used to predict the heat pump performances while the EED program calculates the borehole fluid temperature. It is shown that COPH increases with decreasing the temperature of output water for the operation of heating mode and COPR increases with increasing temperature of output water for the operation of cooling mode. The value of specific heat extraction rate must be moderate to insure the reasonable installation cost of borehole system. With $1^{\circ}C$decrease of $T_{wo}$ the average COPH increase is estimated as about $0.06/^{\circ}C$(for $T_{wo}\;=\;45{\sim}60^{\circ}C$ range) while with $1^{\circ}C$ increase of $T_{wo}$ the estimation of COPR increase is about $0.13/^{\circ}C$(for $T_{wo}\;= \;5{\sim}11^{\circ}C$ range) at the specific heat extraction rate of 30W/m.

• 한국가스학회지
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• 제4권4호
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• pp.25-33
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• 2000

최근 들어 가혹한 온도 및 압력조건에서 운전이 요구되는 고온배관들의 잔여수명예측은 상당히 중요한 관심사로 부각되고 있다. 이에 고온손상을 정량적으로 평가하여 설비를 안전하게 사용하기 위한 유지기술 및 수명평가 기술을 확보하는 것은 매우 중요하다. 한편 이러한 고온배관내 대부분의 균열은 반타원 표면균열의 형태로 형상화되어 파괴역학의 실제응용에서 발견할 수 있는 가장 복잡한 형상과 하중특성을 갖게 된다. 이를 배경으로 본 연구에서는 먼저 축방향 및 원주방향 반타원 표면균열이 존재하는 직관의 완전 3차원 유한요소망 자동생성 프로그램을 작성하였다. 이렇게 생성된 유한요소 입력자료를 이용하여 3차원 유한요소 해석을 수행하면 반타원 표면균열선단을 따른 고온 크리프 파괴 지배변수 $C^{\ast}$-적분값을 구할 수 있다. 또한 $C^{\ast}$-적분값에 준해 균열진전량을 계산하는 후처리 균열진전 모듈을 추가하여 사용자 편의 수명평가 프로그램을 개발하였다. 최종적으로 개발된 통합 수명 평가 프로그램을 이용하여 여러 가지 해석변수들의 반타원 표면균열을 갖는 고온 직관 수명에 대한 영향을 살펴보았다.