• 한국컴퓨터정보학회논문지
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• 제21권6호
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• pp.107-115
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• 2016

In this paper, we propose a Bicycle sharing has grown popular around the cities in the world due to its convenience. However, the bicycle sharing system is not problem-free, and there remains many managerial problems to be solved. In this study, we analyzed pricing strategy of a bicycle sharing system by minimizing the number of bicycles relocated by trucks, the act of which incurs penalty. The objective function is constructed by applying mixed integer programming and is presented as a stochastic model by using Markov chain so that arrival and departure rates of bicycle stations can be utilized in the analysis. The efficiency of the presented model is verified upon the analysis of bicycle sharing data gathered in Daejeon in 2014.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.53-62
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• 2017

Many gradient-based mathematical methods have been developed and are in use for structural size optimization problems, in which the cross-sectional areas or sizing variables are usually assumed to be continuous. In most practical structural engineering design problems, however, the design variables are discrete. The main objective of this paper is to propose an efficient optimization method for structures with discrete-sized variables based on the harmony search (HS) meta-heuristic algorithm that is derived using penalty function. The recently developed HS algorithm was conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary. In this paper, a discrete search strategy using the HS algorithm with a static penalty function is presented in detail and its applicability using several standard truss examples is discussed. The numerical results reveal that the HS algorithm with the static penalty function proposed in this study is a powerful search and design optimization technique for structures with discrete-sized members.

• Journal of Advanced Marine Engineering and Technology
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• 제32권5호
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• pp.785-790
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• 2008

A technique for determining the feedback gain of the states feedback controller using a real-coded genetic algorithm(RCGA) is presented. It is concerned with the states error to the performance index of a RCGA. As for assessing the performance of the controller three performance criteria (ISE. IAE and ITAE) are adopted. And designing the controller involves a constrained optimization problem. Therefore a real-coded genetic algorithm incorporating the penalty strategy is used. The performance of the proposed method is demonstrated through a set of simulation about an inverted pendulum system.

• 제어로봇시스템학회논문지
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• 제6권4호
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• pp.268-275
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• 2000

The increasing technological demands of today call for complex systems, which in turn involve a series of optimization problems with some equality or inequality constraints. In this paper, we presents a real-coded genetic algorithm(RCGA) as an optimization tool which is implemented by three genetic operators based on real coding representation. Through a lot of simulation works, the optimum settings of its control parameters are obtained on the basis of global off-line robustness for use in off-line applications. Two optimization problems are Presented to illustrate the usefulness of the RCGA. In case of a constrained problem, a penalty strategy is incorporated to transform the constrained problem into an unconstrained problem by penalizing infeasible solutions.

• Steel and Composite Structures
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• 제33권2호
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• pp.163-180
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• 2019

A semi analytical method is employed to analyze free vibration characteristics of uniform and stepped functionally graded circular cylindrical shells under complex boundary conditions. The analytical model is established based on multi-segment partitioning strategy and first-order shear deformation theory. The displacement functions are handled by unified Jacobi polynomials and Fourier series. In order to obtain continuous conditions and satisfy complex boundary conditions, the penalty method about spring technique is adopted. The solutions about free vibration behavior of functionally graded circular cylindrical shells were obtained by approach of Rayleigh-Ritz. To confirm the dependability and validity of present approach, numerical verifications and convergence studies are conducted on functionally graded cylindrical shells under various influencing factors such as boundaries, spring parameters et al. The present method apparently has rapid convergence ability and excellent stability, and the results of the paper are closely agreed with those obtained by FEM and published literatures.

• 한국공간구조학회논문집
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• 제4권4호
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• pp.91-98
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• 2004

유전자 알고리즘은 가장 훌륭한 이산최적화 기법 중 하나이다. 그러나, 유전자 알고리즘은 무제약 최적화 기법이기 때문에 제약조건은 간접적으로 표현된다. 가장 일반적인 방법은 벌칙함수를 사용하여 제약 문제를 무제약 문제로 변환하는 것이다. 본 연구에서는 적합도에 벌점함수를 적용하여 거부전략, 벌점전략, 복합전략 등에 따른 3가지 함수를 구성하였다. 그리고, 이 적합도 함수들을 사용한 설계프로그램을 구현하고, 산형골조와 2층 3경간 골조의 설계문제에 적용시켜 설계결과를 비교하였다. 이를 통하여 유전자 알고리즘을 이용한 유용한 골조 설계프로그램의 구현이 가능할 것으로 판단된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.816-818
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• 2005

In this paper, we have developed an hourly operating strategy for Direct load control (DLC) considering the efficiency of DLC program and increasing the utility of DLC resource. According to the operating code for DLC, the DLC center should curtail the load for 4 hours when the control notification has been enforced. Since the above strategy may limit the participation of entities, who intend to take part in the DLC program, the new strategy to mitigate the above limitation is required. In this paper, we have developed the operating strategy of DLC program and the mechanism to apply the proposed strategy in the DLC center. The proposed strategy makes the important role from the view of guaranteing the effective alternative raising the participation and avoiding the penalty of the entities.

• 인지과학
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• 제28권1호
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• pp.65-90
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• 2017

본 연구의 목적은 학습상황에서 피드백으로 주어지는 금전적 획득/손실(학습 피드백)과 비학습적 상황에서 우연히 제시되는 의사 피드백(무선 피드백)을 비교하는 방법을 사용하여, 금전적 보상과 처벌의 학습 피드백으로서만 가지는 정보처리에 어느 두뇌 영역이 관여하는지를 규명하는 데 있다. 이를 위해 정상 성인(n = 22)을 대상으로 fMRI scan 동안 단서 자극에 대한 범주 버튼 반응(좌/우)의 정확 여부에 따라 피드백이 제시되는 시행(학습시행)과 단서 자극의 위치판단 반응과 무관하게 피드백이 제시되는 시행(무선시행)을 사건 관련 fMRI 방략으로 제시하였다. 두 시행 간 보상과 처벌과 같은 동기적 사건에 대한 두뇌 반응이 변별적으로 나타나는지를 알아보기 위해 시행 유형(학습 vs. 무선)과 피드백 유형(보상 vs, 처벌)을 두 독립변인으로 한 반복측정 이원분산분석을 하였다(voxel-wise FWE p < .001). 그 결과, 좌측 배외측 전두피질(dorsolateral prefrontal cortex), 좌측 전측 도(anterior insular), 배내측 전두피질(dorsomedial prefrontal cortex) 등의 영역에서 유의한 상호작용 효과가 관찰되었는데, 이들 영역은 모두 학습-보상 피드백 및 무선-처벌 피드백보다 학습-처벌 피드백에 대해 증가한 두뇌 활성을 보였다. 본 연구 결과는 학습상황에서 주어지는 처벌 피드백에 대한 기존 전략의 변경이나 재평가를 위한 집행적 처리, 적절하지 못하거나 틀린 행동에 대한 오류처리 과정 그리고 실패 경험에 대한 부정적 정서처리가 위에서 언급한 피질신경망을 중심으로 이루어질 가능성을 보여준다. 따라서 학습의 처벌 피드백은 보상과 달리 위와 같은 추가적 정보처리 과정이 존재할 가능성을 시사한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.699-704
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• 2000

The present paper deals with a multiobjective optimization method based on the co-evolutionary genetic strategy. The co-evolutionary strategy carries out the multiobjective optimization in such way that it optimizes individual objective function as compared with each generation's value while there are more than two genetic evolutions at the same time. In this study, the designs that are out of the given constraint map compared with other objective function value are excepted by the penalty. The proposed multiobjective genetic algorithms are distinguished from other optimization methods because it seeks for the optimized value through the simultaneous search without the help of the single-objective values which have to be obtained in advance of the multiobjective designs. The proposed strategy easily applied to well-developed genetic algorithms since it doesn't need any further formulation for the multiobjective optimization. The paper describes the co-evolutionary strategy and compares design results on the simple structural optimization problem.

• 품질경영학회지
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• 제27권2호
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• pp.1-19
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• 1999

It is truism to say that today's customers demand high quality products and services; nevertheless, nowhere is this more prevalent than in the medical industry. Korea's globalization has increased it's citizen's awareness of greater life expectancies and medical improvements in other regions of the globe. Therefore, it is universally essential that in order to be successful in the medical industry, vendors must meet the ever increasing demands of better educated customers. The purpose of this study was twofold: 1) The first objective was discover what health care services are in demand and the quality factors related to these services. 2) The second objective was to determine a strategy for improving health care service through quality function deployment(QFD). One hundred and ninety-five respondents were randomly selected and asked to fill out a questionnaire after having undergone treatment at a medical clinic, located in Daejon, South Korea. The questionnaire was designed to obtain information about both he clients' satisfaction with, and their sense of the value of the medical treatment they received. Penalty-reward analysis and QFD were used to interpret the survey results and to deploy the collective voices of the customers. The results of the penalty-reward analysis illustrated that the 'communication' service quality factor was classified into an excitement factor that incurs no penalty if not achieved but adds value if the requirement is exceeded. As a result of the QFD analysis on the 'communication' service quality factor, eleven strategic alternatives were prioritized, and isolated a vital service quality characteristic. This characteristic can be implemented to bring value-added changes for the improvement of health care services.