• 방송공학회논문지
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• 제15권4호
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• pp.498-512
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• 2010

인트라 프레임 부호화 기술은 임의 접근성과 에러 확산 방지에 용이하기 때문에 비디오 부호화 기술의 필수적인 기술로 자리 잡고 있다. 그러나 인터 부호화 기술에 비해 낮은 부호화 효율이 문제점으로 지적되고 있다. H.264/AVC 인트라 부호화 방식은 기존 표준 방법들보다 부호화 효율을 크게 향상시켰지만 부호화 과정이 복잡하여 저 비트율 기반의 양방향 서비스에는 부적합하다. 따라서 본 논문에서는 복호화기 측의 예측을 이용해 인트라 부호화 효율을 보다 향상시키며 부호화 시간을 단축시키는 V-IMBS (Voting-based Intra Mode Bit Skip)를 제안한다. 제안하는 방법은 복호화기가 부호화기에서와 동일하게 최적의 인트라 예측 모드를 결정할 수 있으면 인트라 예측 모드를 전송하지 않는다. 그러나 최적의 인트라 예측 모드를 결정할 수 없을 경우에는 기존의 H.264/AVC 표준과 동일한 방식으로 인트라 예측 모드를 부호화하여 복호화기로 전송한다. V-IMBS는 H.264/AVC보다 시험 시퀀스에 대해 PSNR 값이 평균 약 0.24 dB 정도 향상되었고, 비트율도 평균 약 4.44% 정도 감소되었다. 또한 전체 부호화 시간도 평균 약 42.8% 정도 감소되었다.

• 한국과학교육학회지
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• 제21권2호
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• pp.279-288
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• 2001

본 연구에서는 인지 갈등 유발 전략(CCS)과 사회적 합의 형성 전략(SCS) 하에서 진행된 소집단 토론의 상호작용 양상을 비교하였다. 과학 개념을 학습하는 4개 소집단 16명의 학생들을 대상으로 개별 진술, 상호작용 단위, 에피소드 수준에서 언어적 상호작용을 분석하였다. 토론 1회 당 전체 개별 진술이나 지식구성 진술은 CCS 집단에 비해 SCS 집단에서 많이 나타났다. 특히, 가설의 비교 평가나 토론 활동지는 SCS 집단 학생들의 메타인지적 진술을 증가시키는 데 효과적이었다. SCS 집단에서는 다수 참여형 및 정교화 상호작용이나 탐구형 에피소드의 빈도가 상대적으로 높아, 많은 학생들이 소집단 토론에 참여하였고 상호작용적인 정교화 토론이 진행된 것으로 나타났다. 상호작용이나 에피소드의 질적인 측면에서도 SCS 집단이 CCS 집단보다 우수하였다.

• 한국융합학회논문지
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• 제11권12호
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• pp.31-37
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• 2020

모바일 인터넷의 급속한 발전과 더불어 컴퓨터 게임의 단말이 PC에서 모바일로 점차 바뀌고 아울러 모바일 게임은 많은 사람들이 여가 시간에 삶의 즐거움을 향유하는 절호의 선택이 되고 있다. 최근, 다양한 타입의 모바일 게임 가운데 FPS 타입의 게임 사용자가 큰 폭으로 증가되고 있다. 본문은 도날드 노먼 (Donald Norman)의 《Emotional Design》에 기초하여 중국에서 가장 인기 있는 FPS 게임인 《Game for peace》과 한국에서 가장 인기있는 FPS 게임인 《배틀그라운드》의 인터랙션 디자인을 비교하면서 이 두 게임의 공통점과 차이점을 분석하고 이를 근거로 감정 인터랙션 디자인의 삼차원 이론을 총결산하였다. 삼차원 이론은 본능층과 행동층, 사고층으로 나뉘며 각각 인터렉티브 인터페이스, 인터랙티브 행동, 인터랙티브 체험이 이 두 게임에서의 감정적인 표현이다. 또한 이 이론은 모바일 게임을 비롯한 정보화 산업의 인터랙션 디자인에 조언을 제공한다.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2002년도 Language, Information, and Computation Proceedings of The 16th Pacific Asia Conference
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• pp.2-27
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• 2002

As pact of a long-ranged project that aims at establishing database-theoretic semantics as a model of computational semantics, this presentation focuses on the development of a syntactic component for processing strings of words or sentences to construct semantic data structures. For design arid modeling purposes, the present treatment will be restricted to the analysis of some problematic constructions of Korean involving semi-free word order, conjunction arid temporal anchoring, and adnominal modification and antecedent binding. The present work heavily relies on Hausser's (1999, 2000) SLIM theory for language that is based on surface compositionality, time-linearity arid two other conditions on natural language processing. Time-linear syntax for natural language has been shown to be conceptually simple and computationally efficient. The associated semantics is complex, however, because it must deal with situated language involving interactive multi-agents. Nevertheless, by processing input word strings in a time-linear mode, the syntax cart incrementally construct the necessary semantic structures for relevant queries and valid inferences. The fragment of Korean syntax will be implemented in Malaga, a C-type implementation language that was enriched for both programming and debugging purposes arid that was particluarly made suitable for implementing in Left-Associative Grammar. This presentation will show how the system of syntactic rules with constraining subrules processes Korean sentences in a step-by-step time-linear manner to incrementally construct semantic data structures that mainly specify relations with their argument, temporal, and binding structures.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권5호
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• pp.280-286
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• 2006

The paper proposes a new protection algorithm for reliable operation of grid-interfaced PV system, which can flexibly interact with conventional protective schemes of power utility grid not only to prevent damages to utility or public persons and utility apparatus caused by malfunction or failure in distribution network protection system, but also to protect a PV system itself from faults or abnormal conditions of the network. The proposed algorithm is based on reclosing characteristics of the distribution system. As a network fault occurs, the new scheme determines whether it is momentary or permanent and responds in a pre-programmed way to the fault. For permanent outage, the proposed algorithm shuts down inverter's operations but monitoring system voltage and frequency at the point of common coupling with grid. When it comes to the momentary outage, Inverter starts stand-by operation mode so that it can be automatically connected to the grid without start-up procedures as soon as the system voltage and frequency returns into the normal operation range. In order to investigate' and evaluate the PV system operation, simulation study based on PSCAD/EMTDC has been carried out to verify the performance of the proposed protection scheme.

• 비파괴검사학회지
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• 제26권3호
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• pp.153-161
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• 2006

A simulation program SIMULTSONIC is under development at CNDE to help determine and/or help optimize ultrasonic probe locations for inspection of complex components. SIMULTSONIC provides a ray-trace based assessment for immersion and contact modes of inspection. The code written in Visual C++ operating in Microsoft Windows environment provides an interactive user interface. In this paper, a description of the various features of SIMULTSONIC is given followed by examples illustrating the capability of SIMULTSONIC to deal with inspection of canonical objects such as pipes. In particular, the use of SIMULTSONIC in the inspection of very thin-walled pipes (with 450 urn wall thickness) is described. Ray trace based assessment was done using SIMULTSONIC to determine the standoff distance and the angle of oblique incidence for an immersion mode focused transducer. A 3-cycle Hanning window pulse was chosen for simulations. Experiments were carried out to validate the simulations. The A-scans and the associated B-Scan images obtained through simulations show good correlation with experimental results, both with the arrival time of the signal as well as with the signal amplitudes.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.238-243
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• 2003

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuated on the variation of insolation, temperature and load. The output power of solar cell is DC, therefore it is necessary to install an inverter among electric power converts. The inverter have to supply a sinusoidal current and voltage to the load and the interactive utility line. In the paper, the proposes a photovoltaic system designed with a step up chopper and single phase PWM voltage source inverter. Synchronous signal and control signal was processed by microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical dropping character. The single phase PWM voltage source inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power, from 10 to $20\%$. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. The inverter supplies an ac power with high factor and low level of harmonics to the load and the utility power system.

• 디지털산업정보학회논문지
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• 제13권3호
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• pp.105-113
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• 2017

Considered as the "new normal" mode of learning, BL has become popular in recent years especially in University education. BL is defined as a learning approach that combines e-learning and face-to-face classroom learning. BL allows for more interactive and reflective learning environment resulting in enhancing learner-directed learning. The adoption of BL in university has made it significant to probe the crucial determinants that would entice instructors and learners to use BL and enhance learning satisfaction. The primary purpose of this study is to investigate the affecting factors of the satisfaction of BL in universities in terms of leaner's aspects. Learner's role is very important in BL, because learner should self-directed study for effective performance and satisfaction in BL environment. Based on prior studies motivation, self-efficacy, and educational expectancy were identified as affecting factors of satisfaction in BL. According to the result of multiple regression, all factors(motivation, self-efficacy, and educational expectancy) were found to be significantly related to the learner's satisfaction in BL. It can provide practical guideline on effective operation strategy for BL in universities.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.15-21
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• 2015

Anaerobic biodegradation of diesel with coexisting heavy metals (Pb) was monitored in batch mode. Two different groups of the indigenous bacteria from a site contaminated with diesel and lead were used in this research: the first group was composed of a single species and the second group was composed of several species. The effect of heavy metals on the microbial population was monitored and confirmed the biodegradation mechanism in each combined contaminant. Growth of the microorganisms in 21 days was observed Diesel > Diesel + Pb > Diesel + Cu > Diesel + Pb + Cu > Diesel + Cr > Diesel + Pb + Cr. Indigenous microorganisms showed the adaptation in the Pb contaminate. Interactive toxic effect using AMES test observed larger synergistic effect than antagonistic in Diesel + Cr and Diesel + Pb + Cr. Therefore, the main effects of diesel biodegradation in the present of heavy metals are likely to exist other factors as well as toxic of heavy metals. This is a necessary part of the future studies.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.605-619
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• 2009

A comparative experimental study of prestressed continuous steel-concrete composite beams was carried out. Two continuous composite beams were tested, one of which was plain continuous steel-concrete composite beam, while the other was a composite beam prestressed with external tendons. Cracking behavior and the load carrying capacity of the beams were investigated experimentally. Full plasticity was developed in the mid-span section each beam, the maximum moments attained at the internal support sections however were governed by local buckling which was related to the slenderness of composite section. It was found that in hogging moment regions, the ultimate resistance of an externally prestressed composite beam would be governed by either distortional lateral buckling or local buckling, or interactive mode of these two buckling patterns. The results show that exerting prestressing on a continuous composite beam with external tendons will increase the extent of internal force and moment redistribution in the beam. The influences of local and distortional buckling on the behaviors of the composite continuous beams are discussed. The Moment redistribution and the load carrying capacity of the prestressed continuous composite beams are evaluated, and it is found that at the ultimate state, the moment redistribution in the prestrssed continuous composite beams is greater than that in non-prestressed composite beams.