• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.397-403
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• 2003

In an attempt to solve multiobjective optimization problems, weighted sum method is most widely used for the advantage that a designer can consider the relative significance of each object functions by weight values but it can be highly sensitive to weight vector and occasionally yield a deviated optimum from the relative weighting values designer designated because the multiobjective function has the form of simple sum of the product of the weighting values and the object functions in traditional approach. To search the design solution well agree to the designer's weighting values, we proposed new multiobjective function which is the functional of each normalized objective functions and considered to find the design solution comparing the distance between the characteristic line and the ideal optimum. In this study, proposed multiobjective function was applied to design high efficiency and low noise axial flow fan and the result shows this approach will be effective for the case that the qualify of the design can be highly affected by the designer's subjectiveness represented as weighting values in multiobjective design optimization process.

• 한국해양공학회지
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• 제27권5호
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• pp.28-35
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• 2013

In this paper, a research on the composition of the nesting algorithm fitness function is carried out by performing various numerical experiments to inspect how it affects the scrap efficiency, allocation characteristics, and time consumption, targeting the nesting results of ship parts. This paper specifically concentrates on a method to minimize the scrap ratio and efficiently use the well-defined remnants of a raw plate after the nesting process for the remnant nesting. Therefore, experiments for various ship parts are carried out with the weighting factor method, one of the multi-objective optimum design methods. Using various weighting factor sets, the nesting results are evaluated in accordance with the above purposes and compared with each set for each ship part groups. Consequently, it is suggested that the nesting algorithm fitness function should be constructed differently depending on the characteristics of the parts and the needs of the users.

• 한국정보과학회논문지:데이타베이스
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• 제32권3호
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• pp.228-242
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• 2005

투영 클러스터링은 고 차원 데이타집합에서 서로 다른 부분공간들에서 클러스터들을 찾으려고 모색한다. 사용자가 출력 클러스터들의 개수와 투영 클러스터들의 부분공간의 평균 차원수를 지정하지 않아도, 거의 최적인 투영 클러스터들을 탐사해내는 알고리즘을 제안한다. 클러스터링의 각 단계에서 알고리즘의 목적 함수는 투영 에너지, 품질, 그리고 이상치들의 개수를 계산한다. 클러스터링에서 투영 에너지를 최소화하고 품질을 최대화하기 위하여, 전체 차원의 표준 편차들을 비교함으로 입력 점들의 밀도 상에서 각 클러스터의 최선의 부분영역을 찾기 시작한다. 부분공간의 각 차원에 대한 가중치 요소가 투영 거리 측정에서 확률 오차를 없애기 위하여 사용된다. 제안된 알고리즘이 투영 클러스터들을 정확하게 발견해내고 대 용량의 데이타 집합에서 비례확장성을 갖는다는 것을 여러 가지 실험으로 보여준다.

• 전기학회논문지
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• 제68권3호
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• pp.471-479
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• 2019

This research proposes a indoor magnetic map matching algorithm that improves the position accuracy by employing multiple magnetic sensors and probabilistic candidate weighting function. Since the magnetic field is easily distorted by the surrounding environment, the distorted magnetic field can be used for position mapping, and multiple sensor configuration is useful to improve mapping accuracy. Nevertheless, the position error is likely to increase because the external magnetic disturbances have repeated pattern in indoor environment and several points have similar magnetic field distortion characteristics. Those errors cause large position error, which reduces the accuracy of the position detection. In order to solve this problem, we propose a method to reduce the error using multiple sensors and likelihood boundaries that uses human walking characteristics. Also, to reduce the maximum position error, we propose an algorithm that weights according to their importance. We performed indoor walking tests to evaluate the performance of the algorithm and analyzed the position detection error rate and maximum distance error. From the results we can confirm that the accuracy of position detection is greatly improved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.407-410
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• 1989

Optimizing transient response for both tracking reference signals and disturbance rejection is determined by the poles and zeros of the transfer function. Thus, optimal pole assignment and how should weighting matrix for the performance index be chosen is very important to achieve optimum transient response. This paper focus its attention on the choosing and analysis of weighting matrix for optimum pole assignment. Optimum pole assignment is defined for linear time-invariant continuous systems.

• 전기학회논문지
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• 제57권10호
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• pp.1744-1751
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• 2008

This paper presents a monitor positioning algorithm to identify the power quality event source in the distribution system with distributed generations. This algorithm determines the appropriate number of monitors and their locations considering power system topology together with distributed generation. This paper summarizes the guidelines of monitor positioning into five principles and defines the weighting factors according to the principles. To evaluate the adequacy of monitor positioning results, ambiguity indices considering monitor location and system topology are proposed. The optimal number and locations of monitors are determined from optimization routine using the weighting factors and the monitor positioning results are evaluated in terms of ambiguity indices. The algorithm is applied to IEEE 13 bus test feeder and suggests the optimal number and locations of power quality monitors. The proposed approach can realize the expert's knowledge on monitor positioning into a sophisticated automatic computing algorithm.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.293-298
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• 1997

The H$_{\infty}$robust controller fur the reactor power control system is designed by use of the mixed weight sensitivity. The system is configured into the typical two-port model with which the weight functions are augmented. Since the solution depends on the weighting functions and the problem is of non-convex, the genetic algorithm is used to determine the weighting functions. The cost function applied in the genetic algorithm permits the direct control of the power tracking performances. In addition, the actual operating constraints such as rod velocity and acceleration can be treated as design parameters. Compared with the conventional approach, the controller designed by the genetic algorithm results in the better performances with the realistic constraints. Also, it is found that the genetic algorithm could be used as an effective tool in the robust design. robust design.

• 한국음향학회지
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• 제18권1호
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• pp.25-31
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• 1999

본 연구에서는 음향측정 목적의 선형배열에 가우시안 가중치를 적용시킨 광대역 단일 빔형성 알고리듬을 제안한다. 제안 알고리듬은 배열 내의 모든 센서를 동시에 사용하여 1회에 광대역 수신 빔을 형성시킨다. 여기서 주파수 종속 함수의 가우시안 가중치는 각 센서의 수신 주파수 범위를 제어하도록 시간지연 보상 전에 적용된다. 시뮬레이션 결과, 제안 알고리듬에 의해 형성된 광대역 단일빔의 지향지수 및 빔패턴 특성이 광대역 음향신호 측정에 가용함을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.549-551
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• 1998

In this paper, we design the optimal satellite-tracking antenna $H_{\infty}$ control system using genetic algorithm(GA). To do this, we give gain and dynamics parameters to the weighting functions and apply GA with reference model to the optimal determination of weighting functions and design parameter ${\gamma}$ that are given by Glover-Doyle algorithm which can design $H_{\infty}$ controller in the state space. These weighting functions and design parameter ${\gamma}$ are simultaneously optimized in tile search domain guaranteeing the robust stability of closed-loop system. The effectiveness of this satellite-tracking antenna $H_{\infty}$ control system is verified by computer simulation.

• 한국통신학회논문지
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• 제42권2호
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• pp.514-522
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• 2017

트래픽 오프로딩은 폭발적으로 증가하는 모바일 트래픽에 대응하기 위한 유망 솔루션이다. 오프로딩 방법 중, LIPA/SIPTO 오프로딩에서는 애플리케이션의 QoS 요구사항을 만족하면서 트래픽을 오프로딩할 수 있다. 또한, SNS로 인한 많은 트래픽때문에 social context를 이용한 트래픽 오프로딩이 필요하다. 그러므로, 본 논문에서는 social context를 이용하여 트래픽을 오프로딩하는 LIPA/SIPTO 오프로딩 알고리즘을 제안한다. 먼저, 애플리케이션 인기도를 social context로 이용하여 애플리케이션 선택확률을 정의한다. 그 다음, effective data rate 관점에서 소형셀 사용자의 QoS를 최대화하는 최적의 오프로딩 weighting factor를 찾는다. 마지막으로, 애플리케이션 선택확률과 오프로딩 weighting factor를 기반으로 각 애플리케이션의 오프로딩 비율을 정한다. 성능분석 결과, 제안한 알고리즘의 오프로딩 비율이 기존 알고리즘의 약 46%임에도 불구하고, 제안한 알고리즘의 effective data rate achievement ratio 값이 기존 알고리즘과 비슷한 것을 확인하였다.