• 한국멀티미디어학회논문지
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• 제19권10호
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• pp.1775-1781
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• 2016

Generally, in the underwater target recognition, feature vectors are extracted from the target signal utilizing spatial information according to target shape/material characteristics. In addition, various signal processing techniques have been studied to extract feature vectors which are less sensitive to the location of the receiver. In this paper, we synthesized active echo signals using 3-dimensional highlight distribution. Then, Fractional Fourier transform was applied to echo signals to extract signal features. For the performance verification, classification experiments were performed using backpropagation and probabilistic neural network classifiers based on single aspect and multi-aspect method. As a result, we obtained a better recognition result using proposed feature extraction and multi-aspect based method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.199-204
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• 2001

This paper showed the study on the heat transfer into space by the aspect ratio of solar concentration absorber, and the purpose of this study is to obtain the optimum aspect ratio and tilt angle. The boundary conditions of a numerical model were assumed as follows : (1) The heat source is located at the center of absorber. (2) The bottom was is opened and adiabatic. (3) The top, right and left walls are cooled wall. The parameters for the study are the tilt angles and the aspect ratio. The velocity vectors and isotherms were dense at wall side and the heat source. The mean Nusselt number had a maximum value at Ar=1:1 and $\theta=0^{\circ}$ and showed a low value as the tilt angles were increased.

• 동력기계공학회지
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• 제6권1호
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• pp.43-49
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• 2002

This paper showed the study on the heat transfer into space by the aspect ratio of solar concentration absorber, and the purpose of this study was to obtain the optimum aspect ratio and tilt angle. The boundary conditions of a numerical model are assumed as follows : (1) The heat source is located at the center of absorber. (2) The bottom wall is opened and adiabatic. (3) The top, right and left walls are cooled wall. The parameters for the study are the tilt angles and the aspect ratio. The velocity vectors and isotherms were dense at wall side and the heat source. The mean Nusselt number had a maximum value at Ar=1:1 and ${\theta}=0^{\circ}$ and showed a low value as the tilt angles were increased.

• Structural Engineering and Mechanics
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• 제62권1호
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• pp.11-20
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• 2017

The base force element method (BFEM) is a new finite element method. In this paper, a degenerated 4-mid-node plane element from concave polygonal element of BFEM was proposed. The performance of this quadrilateral element with 4 mid-edge nodes in the BFEM on complementary energy principle is studied. Four examples of linear elastic analysis for plane frame structure are presented. The influence of aspect ratio of the element is analyzed. The feasibility of the 4 mid-edge node element model of BFEM on complementary energy principles researched for plane frame problems. The results using the BFEM are compared with corresponding analytical solutions and those obtained from the standard displacement finite element method. It is revealed that the BFEM has better performance compared to the displacement model in the case of large aspect ratio.

• 한국공작기계학회논문집
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• 제13권4호
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• pp.73-78
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• 2004

The conventional SLT(Shear Lag Theory) which has been proven that it can not provide sufficiently accurate strengthening predictions in elastic regime when the fiber aspect ratio is small. This paper is an extented work to improve it by modifying the load transfer mechanism called NSLT(New Shear Lag Theory), which takes into account the stress transfer across the fiber ends and the SCF(Stress Concentration Factor) that exists in the matrix regions near the fiber ends. The key point of the model development is to determine the major controlling factor among the material and geometrical coefficients. It is found that the most affecting factor is the fiber/matrix elastic modulus ratio. It is also found that the proposed model gives a good result that has the capability to correctly predict the elastic properties such as interfacial shear stresses and local stress variations in the small fiber aspect ratio regime.

• Tribology and Lubricants
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• 제18권6호
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• pp.384-388
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• 2002

The adequate design of a passenger car braking system, which is directly related to the safety of a car, is very important since the safety is an essential design parameter of a car to keep men and car from the damage. The thermal behaviors of the ventilated disk has been investigated based on the air cooling effects during repeat braking operations. In this study, the thermal behavior of ventilated disk brake system was investigated by numerical method. The 3-Dimensional unsteady model was simulated by using a general purpose software package “FLUENT” to obtain the temperature distributions of disk and pad. The model includes the more realistic braking method, which repeats braking and release. The effects of aspect ratio of ventilated hole on the heat dissipation was investigated.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.397-399
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• 2005

기존의 컴포넌트 모델에서는 컴포넌트 사용과 설정의 분리가 용이하지 않아 개발자가 제약사항(처리시간과 메모리)간의 트레이드 오프(trade-off)를 고려할 수 없을 뿐만 아니라 AOP를 적용하기 힘들다. 본 논문에서는 제어인터페이스를 임의적으로 추가할 수 있는 FCM(fractal component model)을 사용하여 aspect을 적용하였고, 런타임시 비기능적인 속성을 효율적으로 재구성하는 동적 위빙(dynamic weaving)을 지원하기 위해서, fractal component의 제어기능을 담당하는 membrane에 있는 구성요소 중 제어 객체(control object)와 인터셉터 객체(interceptor object)를 간단하게 선택하고 구성하기 위해 혼합클래스를 사용하는 프레임워크를 제안한다. 또한 aspect의 재사용성을 높이기 위해, AspectDataBase를 프레임워크에 설계하였다.

• 한국시뮬레이션학회논문지
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• 제18권3호
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• pp.113-122
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• 2009

사용자가 요구하는 기능과 특성에 대한 다양한 요구사항은 소프트웨어를 점점 더 복잡하게 만들고 이를 검증하고 검사하는 것은 어려운 문제이다. 게다가 개발된 소프트웨어 코드를 검증하고 검사를 수행하는 과정에서 트레이싱 혹은 로깅 코드를 삽입하는 과정과 검사가 완료되어 삭제하는 과정에서 사용자의 부주의로 버그가 삽일될 수 있는 문제점도 발생한다. 본 논문은 소프트웨어 개발 과정 중에서 검증 및 검사 과정을 지원할 수 있는 Aspect DEVS 검증 틀을 제시한다. Aspect DEVS 검증틀은 관점 지향 프로그래밍 기법을 사용하여 이미 구현되어 있는 소프트웨어와 사용자는 요구사항을 만족하는 지를 확인하는 동시에 소스 코드에 테스팅 코드를 삽입할 때 발생하는 문제들을 해결한다. Aspect DEVS 검증틀을 사용한 검증의 첫 번째 단계는 관찰 대상을 관점 지향 프로그래밍 기법을 사용하여 명세한 하고, 사용자의 요구사항을 DEVS 다이어그램을 명세한 후 이를 DEVSIM++로 구현한다. 마지막으로 프로그램의 수행 과정 중에서 발생하는 이벤트들을 대상으로 구현한 DEVS 모델의 이벤트 입력으로 넣어 소프트웨어가 사용자의 요구사항을 만족하는 지를 검사함으로써 검증 과정 중에 대상 소프트웨어의 수정 없이 검증 및 검사를 수행할 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.660-665
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• 1993

An elastic model is developed to predict the average thermal residual stresses in the matrix and fiber of a misoriented short fiber composite. The thermal residual stresses are induced by the mismatch in the coefficient of the thermal expansion of the matrix and fiber when the composite is subjected to a uniform temperature change. The model considers two special cases of fiber misorientation ; two-dimensional in-plane and three-dimensional axisymmetric. The analytical formulation of the model is based on Eshelby's equivalent inclusion method and is nuque in that it is able to account for interactions among fibers. The model is more general than past models and it is able to treat prior analyses of the simpler composite systems as extram cases. The present model is to investigate the effects of fiber volume fraction, distribution type, distribution cut-off angle, and aspect ratio on thermal residual stress for both in-plane and axisymmetric fiber misorientation. Fiber volum fraction, aspect ratio, and disturbution cut-off angle are shown to have more significant effects on the magnitude of the thermal residual stress than fiber distrubution type for both in-plane and axisymmetric misorientation.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1209-1213
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• 2005

It reflects well feature of slope that is characteristic of city river basin of Pusan local. Process various hydrological datas and basin details datas which is collected through basin basis data. weather satellite equipment(EMS-DEU) and automatic water level equipment(AWS-DEU) and use as basin input data of ILLUDAS model, SWMM model and HEC-HMS model In order to examine outflow feature of experiment basin and then use in reservoir design of experiment basin through calibration and verification about HEC-HMS model. Inserted design rainfall for 30 years that is design criteria of creek into HEC-HMS model and then calculated design floods according to change aspect of the impermeable rate. Capacity of reservoir was determined on the outflow mass curve. Designed imagination reservoir(volume $54,000m^3$) at last outlet upper stream of experiment basin, after designing reservoir. It could be confirmed that the peak flow was reduced resulting from examining outflow aspect. Designing reservoir must decrease outflow of urban areas.