• Journal of Advanced Marine Engineering and Technology
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• 제21권5호
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• pp.557-563
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• 1997

The unsteady flow in three-dimensional cubic cavity with narrow channel at upper region is investigated experimentally for three kinds of Reynolds number, 1*10/sup 4/, 3*10/sup 4/ and 5*10/sup 4/ based on the cavity width and cavity inlet mean flow velocity. Instant velocity vectors are obtained simultaneously at whole field by PIV(Particle Image Velocimetry). Wall pressure distributions are estimated using Poisson equation from the velocity data. Results of PIV reveal that severe unsteady flow fluctuation within the cavity are remarkable at all Reynolds numbers and sheared mixing layer phenomena are also found at the region where inlet driving flow is collided with the clock-wise rotating main primary vortex. Instant velocity profiles reveal that deformed forced vortex formation is observed throughout the entire region and spanwise kinetic energy migration is conspicuous.

• 대한교통학회지
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• 제26권2호
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• pp.101-107
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• 2008

실시간의 차량 검지 자료 수집시 검지기 고장이나 네트워크의 지연 등의 문제로 인하여 교통정보가 결측되는 현상이 발생한다. 이는 결과적으로 사용자에게 제공되는 구간별 속도정보의 결측으로 이어진다. 본 논문에서는 이와같이 결측된 속도정보를 보정하여 신뢰성 있는 속도정보 제공을 목적으로 한다. 본 연구는 유사도로의 속도정보를 기반으로 한 여러 신호처리 알고리즘을 사용하였는데, 과거의 속도 정보를 이용하여 가장 좋은 결과를 도출하는 알고리즘을 선정한 후 결측자료를 추정하는 방법으로 결측자료를 도출한다. 서울 시내 간선도로 및 고속도로의 자료를 사용하여 제안된 추정기법의 성능을 보였다.

• 한국심리학회지 : 문화 및 사회문제
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• 제17권1호
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• pp.155-174
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• 2011

한민족 아동의 놀이는 사회의 경제발전 시기에 따라서 차이가 있을 것이라는 가정 아래 한국, 중국과 북한에 거주하는 한민족 아동의 놀이와 놀이가사를 조사한 자료를 분석하여 아동의 놀이가 사회의 경제발전에 따라서 소박한 신체놀이에서 점차 인터넷 게임 등 영상놀이로 이행되는 공통적 변화 양상을 밝혔다.

• 설비공학논문집
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• 제3권4호
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• pp.241-249
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• 1991

A quasi-three dimensional calculation method is presented on the basis of Wu's idea using finite element methods. In B-B flow the governing equations are cast into a single equation to overcome the restriction of the type of turbomachinery, and Kutta condition is exactly assured by introducing a combination of two kinds of stream functions. In H-S flow a dissipative force which is assumed to be opposed to the relative velocity is added to the governing equation for a consistent loss model. The entropy change along each streamline is then calculated by assuming that the dissipative force may be a force coming from laminar viscous stresses with inviscid velocity distributions. Both the flow solvers are combined to build a three-dimensional flow field through a few iterations. For an effect of the distortion of H-S flow surface the body forces are computed after each B-B flow calculation is finished. Mizuki's centrifugal impellers are tested numerically. The reliability of the numerical solution compared with experimental data is guaranteed.

• 인터넷정보학회논문지
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• 제5권6호
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• pp.59-66
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• 2004

본 논문에서는 MPEG 비디오 데이터를 GoP 단위로 분할하여 장면전환 특성을 파악하고 그에 따라 칼만필터를 사용하여 비디오 데이터의 전송량을 예측하는 방법을 제안하고자 한다. 비디오 데이터의 정확한 장면전환을 파악하기 위해서 압축 도메인에서 고속으로 장면에 대한 정보를 검출하는 알고리즘을 사용하여 급진적 장면전환 유형과 점진적 장면전환 유형으로 분류하였다. 분류된 정보는 칼만필터의 세부 인자로 사용되어 비디오 데이터의 전송량을 예측한다. 본 논문에서 제안한 방법은 압축 도메인에서 장면전환 탐지와 비디오 데이터의 전송량을 예측하여 처리 시간을 감소시키고자 하였다. 세 종류의 서로 다른 비디오 데이터 911개의 1프레임을 사용한 실험에서 96.2- 97.6%로 전송량을 예측하였다.

• 한국멀티미디어학회논문지
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• 제6권5호
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• pp.909-920
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• 2003

CRM을 위해서는 다차원 분석이 가능한 OLAP (On-Line Analysis Processing)기술을 적 용한 방법 그리고 데이타 마이닝을 이용한 방법들이 각광 받고 있다. 고객 데이터 중에서 웹 로그 데이터를 실시간에 다차원 분석을 하기 위해서는 OLAP을 사용해야 한다. 그러나 OLAP을 적용하게 되면 웹 로그 데이터 자체가 가지고 있는 특성에 의해 희박성이 발생되고, 사전 집계 연산을 수행 할 시 데이터의 폭발(Explosion)현상이 일어난다. 이는 저장공간의 낭비 뿐 아니라 다차원 질의 시 성능 저하를 발생 시킨다. 본 논문에서는 웹 로그 데이터의 희박성에 대한 체계적인 접근을 위해 희박성을 발생시키는 원인과 2,3 차원의 희박성 형태들에 대해 밝혀보고, 이러한 분석을 기반으로 성능 평가를 위한 테스트 데이터 모델과 질의 모델을 설계하였다. 그리고 희박성 처리를 위해 청크 방식을 사용한 MOLAP시스템을 구현해 보고, 이 시스템과 MS SQL 2000 Analysis Services, Oracle Express의 성능을 평가 및 분석 해보았다. 이는 웹 로그 데이터내의 희박성을 효율적으로 처리할 수 있는 저장구조와 인덱스 방식을 발견하는데 토대가 될 수 있다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.248.1-248
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• 1999

Preliminary analysis of in-reactor thermal performance of three MOX fuel rods, which are going to be irradiated in the Halden reactor beginning in the first Quarter of the year 2000 under the framework of the OECD Halden Reactor Programme, have been conducted by using the computer code COSMOS to ensure their safe operation. Parametric studies have been carried out to investigate the effect of uncertainties on in-reactor behavior by considering the four kinds of uncertainties; thermal conductivity, linear power, manufacturing parameters, and model constants. The analysis shows that, in the case of annular MOX -1 fuel, calculation results for thermal performance vary widely depending on the selection of model constants for fission gas release (FGR). On the contrary, the thermal performance of solid MOX - 3 fuel does not depend on the choice of FGR constants to a large extent as MOX-I, because the fuel temperature is very high in the MOX-3 irrespective of the choice of FGR constants and hence the capacity of grain boundaries to retain gas atoms is not large enough to accommodate the number of gas atoms reaching the grain boundaries. It is planned that when the data on microstructure and thermal conductivity for each type of MOX fuel are available, new analysis will be made using these information. In addition, FGR model constants will be derived from the measured fuel centerline temperature, rod internal pressure and other related data.

• 한국가정과학회지
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• 제1권2호
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• pp.100-112
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• 1998

The purpose of this study is to investigate the torso patterns by analyzing sensory evaluations. The anthropometric measurements for female college students were obtained between March and October in 1998, and a total of 197 anthropomatric data was used for the somatotype analysis. The appearance and fit of three kinds of torso patterns(ESMOD, FIT, and Muller & sohn) were evaluated by expert panel and the subjects. The results of the anthropometric measurements and sensory evaluations are as follows; The mean height of the anthropometric data for 197 students is 158.98cm. The largest proportion of the three somatotypes(H, M and A type) is big hip type(A type) consisting of 47.7% of all the respondents. The result of the torso pattern evaluations by expert panel indicates that the ESMOD pattern obtains the highest rating in general acceptability. A significant difference(p<.05) in the responses to two questions, the placement of the waist dart, and the gapping & creasing at back hip area was found. The ESMOD and Muller & sohn patterns are given the highest rating in the general acceptability. The result of the evaluation was obtained by the subjects. (Korean J. Human Ecology 1(2):100∼112, 1998)

• Ocean and Polar Research
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• 제34권2호
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• pp.265-273
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• 2012

A new algorithm was developed, not only to detect the existence of a thermocline, but also to extract the thermocline parameters (such as thermocline thickness, mixed layer thickness, maximum temperature gradient, and temperature difference of thermocline), using the vertical profile of water temperature. According to Kappa analysis, in order to find adequate threshold values of vertical water temperature gradients ${\Delta}T$ ($^{\circ}C/m$), agreement and reliability were 87% and 0.74 respectively, in the conditions of maximum ${\Delta}T{\geq}0.5$ and surface and bottom layers ${\Delta}T<{\mid}0.2{\mid}$. Also, three different kinds of methods, viz. 1. Gradient method, 2. Hyperbolic tangent method, and 3. Differential hyperbolic tangent method, were tested to extract the key parameters of a thermocline. Comparing the results of three different methods, the differential hyperbolic tangent method was the most appropriate to extract the start and end point of a thermocline curve.

• 분석과학
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• 제18권1호
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• pp.51-58
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• 2005

A comparison of the analytical data obtained by three $k_0$-NAA software programs was carried out using both the airborne particulate matter collected from an urban site and the certified reference materials of the air filter and urban dust to evaluate the performance of the analysis. The individual $k_0$-NAA standardization methods of three countries, Korea, China and Vietnam which had been modified from the well established $k_0$-program were used for the comparative analysis. The measured concentrations of 30 elements from the two kinds of air samples based on this software were in agreement with each other within about 20% analytical error except for a few elements. By contrast, the results of China and Vietnam were moderately higher than that of Korea due to a systematic error associated with the detection efficiency, gamma peak analysis and geometric effect.