• 한국컴퓨터정보학회논문지
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• 제16권5호
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• pp.101-107
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• 2011

본 논문에서는 적응 배열 안테나 시스템에서 간섭 및 재밍 신호를 제거하기 위해서 최적 가중 벡터를 연구하였다. 최적 가중 벡터는 선형 제한 조건에서 최소 분산 알고리즘과 비용함수를 적용시켜 구하였고, 목표물의 신호를 정확히 추정하였다. 적응 배열 안테나 시스템은 간섭 및 재머전력을 감소시키고 신호대 잡음비를 향상시키는 시스템이다. 적응 배열 안테나 시스템은 각 안테나 배열 소자의 출력이 탭(Tap)을 거쳐 지연되고 각 탭에 복소 가중치가 곱해져서 최종적으로 하나의 복합신호를 만든다. 최적의 가중치를 구하기 위해서 본 논문에서는 입력 공분산 행렬의 최적 가중벡터를 이용하였다. 본 논문에서 제안된 알고리즘으로 모의 실험한 결과 분해능은 $3^{\circ}$이하로 향상되었으며 부엽은 약 10 dB 감소하였음을 입증하였다.

• 한국통신학회논문지
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• 제40권12호
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• pp.2324-2330
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• 2015

충격성 잡음하의 블라인드 신호처리 분야에서 최대 상호 코렌트로피 알고리듬 (MCC)이 MSE 기반의 알고리듬에 비해 우수한 성능을 보인다. 그러나 MCC 알고리듬에 대한 최적 가중치 조건들이나 충격성 잡음에 대한 내성과 관련된 특성들은 아직 충분히 연구되지 못한 상태이다. 이 논문에서는 MSE기반의 LMS 알고리듬과 비교를 통해 MCC의 최적 가중치의 성질을 분석하여 MCC 알고리듬의 최적 가중치가 MSE기반의 LMS 알고리듬과 같다는 보인다. 또한 MCC의 최적 가중치가 충격성 잡음 하에서도 동요 없이 안정을 유지하는 요인이 입력 크기 조정에 있다는 것을 시뮬레이션을 통해 입증하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.173-178
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• 2001

The cost on transmission and election of precast concrete members largely depends on the weight of them. In this study, the weight of prestressed precast beam could be reduced by control the section and prestressing force to meet the required strength on the basis of the optimum process. The top and bottom concrete stress of the section considered is required to check according to each construction step for this process. The original rectangular beam weight could be reduced up to 50~39% due to the development of a U-beams from the optimum process.

• 한국항해학회지
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• 제13권2호
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• pp.75-95
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• 1989

The study presents the optimum design of B/C midship structure based on the classification society's Rule. The SUMT (Sequential Unconstrained Minimization Technique), using the Direct Search Methods (Hooke and Jeeves, Simplex) is applied to the solution of this nonlinear optimum design problem with constraints. Through the optimum designs of existing ships(60k, 186k, 220k), the amount 0.45-6.18% in weight of their midship structures are obtained on the viewpoint of minimum weight design.

• 인터넷정보학회논문지
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• 제17권3호
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• pp.19-24
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• 2016

최소오차 엔트로피 알고리듬(MEE)은 충격성 잡음 환경에서 성능이 우수한 것으로 알려져 있다. 이 논문에서는 충격성 잡음에 대한 강인성의 견지에서 MEE 알고리듬의 최적해와 특성을 연구하였다. 큰 오차 값의 영향을 경감하는 요인들과 최적 가중치의 움직임에 대한 분석을 통하여 MEE의 최적해가 충격성 잡음으로부터 안정적으로 유지되도록 하는 주된 역할은 크기 조정된 입력 엔트로피가 담당하고 있음이 밝혀졌다. 시뮬레이션 결과에서, MEE의 최적해는 MSE 성능기준의 최적해와 같은 값을 가짐을 보였다.

• 품질경영학회지
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• 제9권2호
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• pp.10-14
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• 1981

Products are assumed to be spoiled and not recoverable when the raw material below the prescribed weight level is charged in the mold. The raw material is autoscaled and their weight is normally distributed with a given variance. This paper describes an appropriate stochastic model of determining the optimum weight allowance and the associated defective rate for auto scale system. The optimum weight allowance and the defective rate which minimizes the total loss of defective and the excess weight allowance is obtained. A numerical example for the existing rubber company is also presented and evaluated.

• 대한조선학회지
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• 제21권4호
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• pp.29-39
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• 1984

In this paper, the membrane and buckling analysis of beams with various shaped brackets is performed by using the finite element method. From the viewpoint of minimum structural weight, a optimum design method to determine the optimal shapes and scantling of brackets under design load is proposed by investigating the effects of beam depth, bracket length and aspect ratio on the structural weight. Also optimal design data and charts for the brackets to support transverse girders or web frames of actual ships are provided. By the present design method, it is possible to perform optimum design of brackets used in actual ships, which could result in considerable reduction of structural weight or cost, increase of dead weight and service speed of ships.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.53-61
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• 2014

In this paper, we proposed covariance weight matrix using SPT matrix in order to accurate target estimation. We have estimated a target using modified covariance matrix and beam steering error method. We have minimized beam steering error in order to estimation desired a target. This method obtain optimum covariance weight using modified SPT matrix. This paper of proposal method is showed good performance than general method. We updated a weight of covariance matrix using modified SPT matrix. We obtain optimum covariance matrix weight to application beam steering error method in order to beam steering toward desired target. Through simulation, we showed that compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.231-236
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• 1996

Recently to develope an automobile with better properties, much researches and investments are executed in many countries. In this paper, the weight of an engine block intend to minimize without changing the natural frequency. The weight minimization of an engine block is started from much less initial thickness than original thickness of the model and performed by using the sensitive analysis method and the optimum structural modification method. It can be considered that the weight minimization is completed through this process, because the optimum structural modification method includes the constraint of minimum changing quantity.

• Structural Engineering and Mechanics
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• 제35권5호
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• pp.539-554
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• 2010

Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.