• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.43-53
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• 1998

This paper addresses an optimization for reducing a steering error of a rack-and-pinion steering linkage with a MacPherson strut independent front suspension system. The length, orientations and inner joint positions of a tie-rod are selected as design variables and Ackerman geonetry, understeer effect, minimum turn radius, wheel alignment and packaging are considered as design constraints. Nonlinear kinematic analysis of the steering system is performed for calculating the values of cost and constraints, and Augmented Lagrange Multiplier(ALM) method is used for solving the constrained optinization problem. The optimization results show that the steering error are considerably reduced while satisfying all the constraints.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.635-641
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• 2005

This paper presents an ASF (Aluminum Space Frame) BIW (Body in White) optimal design, which minimizes weight and satisfies multidisciplinary constraints such as static stiffness, vibration characteristics, low-/high-speed crash, and occupant safety. As only one cycle CPU time for all the analyses is 12 hours, the ASF design having 11-design variable is a large scaled problem. In this study, ISCD-II and conservative least square fitting method were used for efficient RSM modeling. Likewise, the ALM method was used to solve the approximate optimization problem. The approximate optimum was sequentially added to remodel the RSM. The proposed optimization method uses only 20 analyses to solve the 11-design variable problem. Moreover, the optimal design can achieve $15.6\%$ weight reduction while satisfying all the multidisciplinary design constraints.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.253-258
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• 2000

Recently, the area of design optimization, especially structural optimization, has been and to be a continuous active area of research. And the design optimizations of port facilities have been achieved by many other civil engineers. But the design optimization of port facilities were limited to the design optimization of the breasting dolphin. This paper invested the design optimization of mooring pier and the foundations of mooring pier was suggested considering the convenience of repair and reinforcement work. The mooring pier devised with prestressed precast concrete panel and rigid frame welded wide flange beam to steel pipe pile. To accomplish the design optimization of mooring pier, the Augmented Lagrangian Multiplier Method(ALM) of ADS(Garret N. Vanderplaats) optimization routine, BFGS method as optimizer and Golden Section Method as one dimensional search were utilized. As a result, thirty percent of material cost for construction was reduced by design optimization. The tensile stress of concrete panel and bottom flage was critical constraints under service load. So, using high strength concrete and steel will be economical. And lots of initial values must be invested to accomplish the design optimization in design procedures.

• Korean Journal of Poultry Science
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• v.17 no.4
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• pp.269-274
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• 1990

Chromosome complements of Japanese quail (Coturnix coturnix japonica) were studied using several tissues which involving testis, leukocytes and embryos. The diploid count was estimated to be 2n＝78. Analyzing the metaphase of secondary meiosis in spermatocytes, the haploid count estimated to be n＝39. Morphometric analysis were studied by the centromeric index and relative length of 8 macro-chromosomes and Z, W chromosomes The differences of morphological feature were not significant among tissues. Exceptionally the chromosome 4 shelved a considerable variety in the presence of it's short arm.

• Tribology and Lubricants
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• v.8 no.2
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• pp.26-34
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• 1992

This paper suggests a method to predict the flying state of the head slider in a hard disk drive (HDD) by using an optimization technique. The modified Reynolds equation for the hydrodynamic lubrication theory under the slip flow condition is used to describe the air-bearing system and a Finite Volume Method (FVM) is applied to solve the equation. Especially, Augmented Lagrange Multiplier (ALM) method is employed to find the minimum flying height, the pitch angle and the roll angle of the slider, which is shown to be faster and more general than the conventional update schemes. By using the proposed method, the variations of the flying state are analyzed as a function of the slider position in the direction of the disk radius for various disk velocities and skew angles.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.145-152
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• 1998

This paper presents an optimum design of a rotor-bearing spindle system for a ultra centrifuge (80,000 RPM) supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modeled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyzed by using a transfer-matrix method iteratively. For optimization. we use the cost function that simultaneously minimizes the weight of a rotor and maximizes the separation margins to yield the critical speeds as far from the operating speed as possible. Augmented Lagrange Multiplier (ALM) method is employed for the nonlinear optimization problem. The result shows that the rotor-bearing spindle system is optimized to obtain 9.5％ weight reduction and 21％ separation margin.

• Journal of the Korea Safety Management & Science
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• v.2 no.1
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• pp.59-75
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• 2000

최근의 추세를 볼 때 위험관리에 관한 중요성이 점점 증대하고 있다. 그럼에도 불구하고 우리나라 은행들의 위험관리 실태는 아직 미흡한 실정이다. 그리고 대부분의 은행들이 현재 위험관리에 대응하기 위하여 ALM의 갭관리, 듀레이션관리 등을 행하고 있지만 BIS에서 중요시하고 있는 VaR의 개발과 운용은 아직 초보단계에 있다. 한국 주식포트폴리오에서 몬테카를로 시뮬레이션과 Full Variance Covariance Model의 VaR값은 비슷한 수준으로 Diagonal Model 의 VaR값 보다 작음을 알 수 있다. 이는 좀 더 정교한 계산이 요구되는 Full Variance Covariance Model의 VaR값이 보다 단순한 Diagonal Model의 VaR값 보다 정확성면에서 우수하다는 것을 보여주고 있다. 한편 이자율포트폴리오 의 경우에는 델타-감마 분석법과 몬테카를로 시뮬레이션의 경우 95% 신뢰구간의 VaR는 델타-감마 분석법이 작지만 99% 신뢰구간에서의 VaR는 몬테카를로 시뮬레이션방법이 작다는 것을 알 수 있다. 그래서 어느 한 가지 방법에 의한 VaR추정치가 가장 좋은 것이라고 단정하기 어려움을 알 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.12-23
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• 1994

This paper proposes an optimal design software for the open-chain dynamic systems whose governing equations are expressed as differential equation. In this software, an input module and an automatic creation module of the equation of motion are developed to contrive the user's convenience. To analyze the equation of motion of the dynamic systems, variable-order and variable-stepsize Adams-Bashforth-Moulton predictor-corrector method is used to improve the efficiency. For the optimization and the design sensitivity analysis, ALM(augmented lagrange multiplier)method and adjoint variable method are adopted respectively. An output module with which the user can compare and investigate the analysis and the optimization results through tables and graphs is also provided. The developed software is applied to three typical dynamic response optimization problems, and the results compare very well with those available in the literature, demonstrating its effectiveness.

• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.613-615
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• 2018

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.1009-1012
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• 2010

ALM 구현을 위한 툴들 간의 통합 시도는 툴들 간의 통신 복잡성을 증가시키고 툴을 구성하는 컴포넌트 사이의 의존성과 컴포넌트 내부의 복잡성을 증가시킨다. 이는 통합개발환경의 유지보수를 어렵게 하는 결정적 원인이 된다. 따라서 본 논문은 통합개발환경 구성 컴포넌트들 간 통신 및 레이어 구조를 특성(기능) 관리 영역과 지식 관리 영역으로 이원화하고 가이드라인 MVC 모델로 구조화한 통합개발환경 아키텍처를 제시한 소프트웨어 공학 가이드라인 기반 통합개발환경 모델을 제안한다. 제안한 모델은 통합개발환경 구성 컴포넌트의 재사용성, 확장성, 유지보수성 향상과 더불어 통합개발환경 개발/관리자에게 효율적인 개발/관리 지침을 제공한다.