• Journal of the Korean Data and Information Science Society
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• 제24권1호
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• pp.125-133
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• 2013

이 논문에서는 호흡곤란을 주호소로 내원한 668명의 환자를 대상으로 11개 혈액검사 결과를 이용하여 퇴원여부를 결정하는 벌점 이항 로지스틱 회귀 기반 통계모형을 유도하였다. 구체적으로 $L^2$ 벌점에 근거한 능형 모형과 $L^1$ 벌점에 근거한 라소 모형을 고려하였다. 이 모형의 예측력 비교 대상으로는 일반 로지스틱 회귀의 11개 전체 변수를 사용한 모형과 변수선택된 모형이 사용되었다. 10-묶음 교차타당성 (10-fold cross-validation) 비교 결과 능형 모형의 예측력이 우수한 것으로 나타났다.

• 전기의세계
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• 제26권1호
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• pp.77-81
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• 1977

This paper aims to develope a new algorithm to overcome the disadvantages of the conventional E.L.D system based on the B-Constants and Penalty-Factors scheme. The main features of this paper are that the Variabiable Decoupled Method usually employed in the Load-Flow studies is introduced to the E.L.D. algorithm developed by Sasson, using the Powell's Nonlinear Programming Scheme. Besides this, other minor refinements are made to reduce memory spaces and computing time. Case studies show that the method suggested here has the remarkable advantages of computing efficiency and memory requirements over Sasson's.

• Journal of Advanced Marine Engineering and Technology
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• 제24권3호
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• pp.99-105
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• 2000

For multi-body dynamic problems. especially coalescent eigenvalue problems with multiobjective optimization, the design sensitivity analysis is too much complicated mathematically and numerically. Therefore, this article proposes a new technique for structural dynamic modification using a mode modification and homologous structures design method with Genetic Algorithm(GA). In this work, the homologous structure of the resiliently mounted multi-body for marine diesel generator systems is studied and the problem is treated as a combinational optimization problem using the GA. In GA formulation, fitness is defined based on penalty function approach. That include homology, allowable stress and minimum weight of common plate.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.203-211
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• 1999

This paper presents a new approach on genetic on genetic algorithm to economic dispatch problem for valve point discontinuities. Proposed approach in this paper on genetic algorithms improves the performance to solve economic dispatch problem for valve point discontivuities through improved death penalty method, generation-apart elitism, atavism and sexual selection with sexual distinction. Numerical results on a test system consisting of 13 thermal units show that the proposed approach is faster, more robust and powerful than conventional genetic algorithms.

• 한국광학회지
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• 제14권5호
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• pp.509-514
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• 2003

SOA(Semiconductor Optical Amplifier)를 단일 기판에 집적한 Mach-Zehnder 간섭계 구조의 파장변환기를 제작하여 40 nm 지역폭에 대한 10 Gb/s 파장변환 특성을 조사하였다. 제작된 파장변환기는 BRS(Buried Ridge Structure)형 SOA와 수동 도파로를 butt-joint결합하여 단일 집적한 구조이다. 집적화 과정에서 높은 도파 손실을 발생시키는 p+ InP덮개층을 제거하고 무첨가 InP로 도파로 덮개층 및 전류 차단층을 동시에 형성시키는 새로운 방법을 이용하였고, 모듈 제작에서 경사진 도파로와 광섬유를 효율적으로 광 접속하기 위하여 경사진 광섬유 배열을 제작하여 사용하였다. 이와 같이 제작된 파장변환기 모듈을 이용하여 1535-1575 nm의 40 nm 대역폭에서 1 ㏈ 이하의 power penalty를 갖는 10 Gb/s 파장변환을 구현하였고, 특히 negative penalty를 갖는 파장변환을 성공적으로 구현함으로써 2R(re-amplification, re-shaping) 기능을 제공할 수 있음을 보였다.

• Structural Engineering and Mechanics
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• 제23권4호
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• pp.387-407
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• 2006

A Genetic Algorithm (hereinafter GA) based optimum design algorithm and program for plane steel frames with partially restrained connections is presented. The algorithm was incorporated with the refined plastic hinge analysis method, in which geometric nonlinearity was considered by using the stability functions of beam-column members and material nonlinearity was considered by using the gradual stiffness degradation model that included the effects of residual stress, moment redistribution by the occurrence of plastic hinges, partially restrained connections, and the geometric imperfection of members. In the genetic algorithm, a tournament selection method and micro-GAs were employed. The fitness function for the genetic algorithm was expressed as an unconstrained function composed of objective and penalty functions. The objective and penalty functions were expressed, respectively, as the weight of steel frames and the constraint functions which account for the requirements of load-carrying capacity, serviceability, ductility, and construction workability. To verify the appropriateness of the present method, the optimum design results of two plane steel frames with fully and partially restrained connections were compared.

• 한국정밀공학회지
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• 제15권9호
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• pp.117-126
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• 1998

For investigating rubber pad sheet metal forming process, the rubber pad deformation characteristics as well as the contact problem of rubber pad-sheet metal has been analyzed. In this paper, the behavior of the rubber deformation is represented by hyper-elastic constitutive relations based on a generalized Mooney-Rivlin model. Finite element procedures for the two-dimensional responses, employing total Lagrangian formulations are implemented in an implicit form. The volumetric incompressibility condition of the rubber deformation is included in the formulation by using penalty method. The sheet metal is characterized by elasto-plastic material with strain hardening effect and analyzed by a commercial code. The contact procedure and interface program between rubber pad and sheet metal are implemented. Inflation experiment of circular rubber pad identifies the behaviour of the rubber pad deformation during the process. The various form dies and scaled down apparatus of the rubber-pad forming process are fabricated for simulating realistic forming process. The obtaining experimental data and FEM solutions were compared. The numerical solutions illustrate fair agreement with experimental results. The forming pressure distribution according to the dimensions of sheet metal and rubber pads, various rubber models and rubber material are also compared and discussed.

• 로봇학회논문지
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• 제8권3호
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• pp.173-178
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• 2013

We present six-degree-of-freedom (6DoF) haptic rendering algorithms using translational ($PD_t$) and generalized penetration depth ($PD_g$). Our rendering algorithm can handle any type of object/object haptic interaction using penalty-based response and makes no assumption about the underlying geometry and topology. Moreover, our rendering algorithm can effectively deal with multiple contacts. Our penetration depth algorithms for $PD_t$ and $PD_g$ are based on a contact-space projection technique combined with iterative, local optimization on the contact-space. We circumvent the local minima problem, imposed by the local optimization, using motion coherence present in the haptic simulation. Our experimental results show that our methods can produce high-fidelity force feedback for general polygonal models consisting of tens of thousands of triangles at near-haptic rates, and are successfully integrated into an off-the-shelf 6DoF haptic device. We also discuss the benefits of using different formulations of penetration depth in the context of 6DoF haptics.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.578-582
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• 1996

Verification of STL is essential in RP. In the study, triangle based non-manifold geometric modeling that can check intersection between triangles was used to vilify STL. The method proposed in this study can be applied at the most general case and very useful, but has a penalty on computing thime of O(n$^2$)

• Journal of Advanced Marine Engineering and Technology
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• 제37권1호
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• pp.85-90
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• 2013

시간지연을 갖는 불안정한 시스템의 PID 제어는 적용하기가 쉽지 않은데 이는 복소평면의 우반부에 존재하는 극점으로 인한 불안정성과 시간지연의 영향 때문이다. 본 연구에서는 설계자가 제어환경에 따라 오버슈트나 상승시간 등을 미리 정의한 경우의 PID 제어기 설계 기법에 대해 고려한다. 이와 같이 제약성을 갖는 최적화 문제를 해결하기 위해 본 연구에서는 벌점전략이 결합된 RCGA를 사용한다. 이는 제약조건을 위배하면 그 정도에 따라 벌점을 부가하도록 벌점함수를 정의하고, 평가함수에 합하여 비제약성 최적화 문제로 변환하는 방법이다. 제안하는 방법은 불안정 FOPTD 시스템에 적용하고 시뮬레이션을 실시하여 그 유효성을 검토한다.