• 한국통신학회논문지
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• 제29권6A호
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• pp.583-588
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• 2004

이 논문은 Explicit Multicast (Xcast) 방안에서 크기가 큰 밀집 멀티캐스트 그룹과 동적인 그룹 멤버쉽을 지원하는 방안을 제안한다. 이를 위해 도메인 에이전트가 호스트를 대신하여 그룹에 가입하는 계층적 가입 방법을 사용한다. 송신자가 먼저 도메인 에이전트에게 Xcast 패킷을 전송하면, 에이전트가 도메인에 있는 그룹 수신자에게 다시 전송한다. 그리고 호스트는 도메인 에이전트를 통해 언제든지 그룹에 조인하거나 탈퇴할 수 있다. 송신자가 전송하는 Xcast 헤더의 목적지 필드는 도메인 에이전트의 주소를 갖고, 도메인 에이전트가 전송하는 패킷의 목적지에는 도메인 안에 있는 수신자의 주소를 갖는다. 시뮬레이션 결과를 통해 밀집 멀티캐스트 그룹에 대해서 Xcast 헤더 크기화 패킷을 전달하는데 드는 비용을 기존의 방법보다 훨씬 줄일 수 있음을 보인다. 이 방안의 장점은 큰 밀집 그룹에 대해 헤더 오버헤더와 라우터에서의 패킷 처리 시간을 줄이고 동적인 그룹 멤버쉽을 지원한다.

• 한국해양공학회지
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• 제15권3호
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• pp.114-119
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• 2001

Goda formula (Goda, 1973) has been used in the determination of wave pressures acting on a large size caisson such as the pier of the cable stayed bridge at sea. Goda formula, however, is to evaluate the wave pressures acting the infinite vertical caisson of composite breakwater so that it can`t be applied to a large caisson with finite width and length because of diffraction effects. In the present study, three dimensional nonlinear frequence domain method based on perturbation method and boundary integral method is applied to the computation of the linear and nonlinear wave pressures acting on the front of a large size caisson under the variation of its width and length, and angle of incident wave. The numerical results are compared to Goda\`s ones, and then the characteristics of wave pressure distributions acting on a large size caisson are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.213-215
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• 1987

In this paper, influences or grain size on the electro-optic properties were studied on the penferroelectric PLZT ceramics. The specimens were fabricated by the two stage sintering method. Relative permittivity was a little increased with the increment or grain size in 9,9.5/65/35 (La/Zr/Ti) PLZT specimens, and Curie temperature was decreased in the 9.5/65/35 specimens but constant in the 9.5/65/35 specimens. As the grain size was increased, field induced polarization and dP/dE were increased. Because domain walls can be easily moved by electric field. Light transmittance was increased in the 9/65/35 PLZT specimens but there was little effect on the grain size in the 9.5/65/35 PLZT specimens.

• 한국전자거래학회지
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• 제7권3호
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• pp.49-60
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• 2002

Many researchers have studied component technologies with concept, methodology and implementation for partial business domain, however there are rarely researches for component classification to manage these systematically. In this paper, we suggest a component classification model, which can make component reusability higher and can derive higher productivity of software development. We take four focuses generalization, abstraction, technology and size. The generalization means which category a component belongs to. The abstraction means how specific a component encapsulates its inside. The technology means which platform for hardware environment a component can be plugged in. The size means the physical component volume.

• 한국분말재료학회지
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• 제1권2호
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• pp.119-198
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• 1994

The characteristics of various important microstructural factors of WC-base hard- metals (cemented carbides) such as the amount of Co metal binder phase, the carbide grain size, the microstructural defects acting as a fracture source, the solid solubility of tungsten in the binder phase affected by the carbon content, the precipitation of $Co_3W$, the domain size of binder phase, the formation of ${\beta}-free$ layer or Co-rich layer and CVD or PVD coated layer, and the effects of these factors on the flexural strength of the hardmetals are reviewed.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2753-2757
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• 2014

INtegrase Interactor 1 protein (INI1/hSNF5) or BRG1-associated factor 47 (BAF47) is a SWI/SNF-related matrix associated actin dependent regulator of chromatin subfamily B member. DNA binding domain of INI1/hSNF5 is cloned into E.coli expression vectors, pET32a and purified as a monomer using size exclusion chromatography. NMR data show that $INI1^{DBD}$ has folded state with high population of ${\alpha}$-helices. By fluorescence-quenching experiments, binding affinities between $INI1^{DBD}$ and two double stranded DNA fragments were determined as $29.9{\pm}2.6{\mu}M$ (GAL4_1) and $258.7{\pm}5.8$ (GAL4_2) ${\mu}M$, respectively. Our data revealed that DNA binding domain of INI1/hSNF5 binds to transcriptional DNA sequences, and it could play an important role as a transcriptional regulator.

• 한국컴퓨터산업학회논문지
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• 제4권4호
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• pp.589-598
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• 2003

기존의 DWT(Discrete Wavelet Transform) 영역에서 프랙탈 영상압축은 B${\times}$B 블록 크기로 정의역과 치역블록을 구분한 후, 임의의 치역 블록에 대하여 모든 정의역 블록을 탐색하였다. 이러한 기존의 방법은 전체영상 대하여 정의역을 탐색함으로 부호화시 많은 시간이 소요되었다. 이러한 단점을 개선하고 화질을 개선하기 위해 본 논문에서는 DWT 영역에서 레벨과 대역별로 스케일 인자를 갖는 웨이브릿 기반 프랙탈 영상압축 방법을 제안한다. 제안한 방법은 웨이브릿 기반 영역에서 셀프 아핀 시스템을 이용하여 각각의 치역 블록에 대하여 정의역 블록을 선택할 때, 공간적으로 같은 위치에 있는 상위 레벨과 대역별로 AC 계수를 정의역으로 선택한다. 그래서 부호화 시간과 화질을 개선할 수 있다.

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.631-642
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• 2017

Accurate actuator tracking plays an important role in real-time hybrid simulation (RTHS) to ensure accurate and reliable experimental results. Frequency-domain evaluation index (FEI) interprets actuator tracking into amplitude and phase errors thus providing a promising tool for quantitative assessment of real-time hybrid simulation results. Previous applications of FEI successfully evaluated actuator tracking over the entire duration of the tests. In this study, FEI with moving window technique is explored to provide post-experiment localized actuator tracking assessment. Both moving window with and without overlap are investigated through computational simulations. The challenge is discussed for Fourier Transform to satisfy both time domain and frequency resolution for selected length of moving window. The required data window length for accuracy is shown to depend on the natural frequency and structural nonlinearity as well as the ground motion input for both moving windows with and without overlap. Moving window without overlap shows better computational efficiency and has potential for future online evaluation. Moving window with overlap however requires much more computational efforts and is more suitable for post-experiment evaluation. Existing RTHS data from Network Earthquake Engineering Simulation (NEES) is utilized to further demonstrate the effectiveness of the proposed approaches. It is demonstrated that with proper window size, FEI with moving window techniques enable accurate localized evaluation of actuator tracking for real-time hybrid simulation.

• 한국정보통신학회논문지
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• 제16권7호
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• pp.1437-1446
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• 2012

본 논문에서는 스테레오 카메라 환경에서 고속으로 깊이 정보를 얻기 위한 응용분야에 적합한 스테레오 정합 기법을 제안하고자 한다. 이러한 조건을 만족하기 위해서 DWT 영역에서의 주파수 정보와 가변 정합창을 이용하는 적응적인 스테레오 정합 기법을 제안한다. 공간 영역에서 영상의 국부적인 특성을 분석하여 정합창의 크기를 결정하고, 주파수 영역에서 영상의 주파수 특성을 분석하여 정합창의 형태 및 스케일링 요소를 결정한다. 주파수 영역에 대한 정보를 이용하기 위해서 로컬 DWT와 전역 DWT를 활용하는 기법을 모두 적용하였다. 본 논문은 스테레오 정합을 위한 제안한 기법은 유사한 수준의 복잡도에서 고정 정합창 기반의 기법과 비교할 때 PSNR이 향상되는 것을 확인하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 Proceedings International Workshop on New Video Media Technology
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• pp.72-76
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• 1996

We propose a novel algorithm for fractal video sequence coding, based on the circular prediction mapping (CPM), in which each range block is approximated by a domain block in the circularly previous frame. In our approach, the size of the domain block is set to be same as that of the range block for exploiting the high temporal correlation between the adjacent frames, while most other fractal coders use the domain block larger than the range block. Therefore the domain-range mapping in the CPM is similar to the block matching algorithm in the motion compensation techniques, and the advantages of this similarity are discussed. Also we show that the CPM can be combined with non-contractive inter-frame mapping (NCIM), improving the performance of the fractal sequence coder further. The computer simulation results on real image sequences demonstrate that the proposed algorithm provides very promising performance at low bit-rate, ranging from 40 Kbps to 250 Kbps.