• Structural Engineering and Mechanics
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• 제64권1호
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• pp.45-58
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• 2017

This paper presents the application of topology optimization as a design tool for a steel railway bridge. The choice of a steel railway bridge is dictated by the particular situation that it is suitable for topology optimization design. On the one hand, the current manufacturing techniques for steel structures (additive manufacturing techniques not included) are highly appropriate for material optimization and weight reduction to improve the overall structural efficiency, improve production efficiency, and reduce costs. On the other hand, the design of a railway bridge, especially at higher speeds, is dominated by minimizing the deformations, this being the basic principle of compliance optimization. However, a classical strategy of topology optimization considers typically only one or a very limited number of load cases, while the design of a steel railway bridge is characterized by relatively concentrated convoy loads, which may be present or absent at any location of the structure. The paper demonstrates the applicability of considering multiple load configurations during topology optimization and proves that a different and better optimal layout is obtained than the one from the classical strategy.

• 한국건설관리학회논문집
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• 제12권1호
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• pp.43-52
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• 2011

불필요한 자원 이동 및 운반은 건설 현장 작업 생산성에 부정적인 영향을 미치는 주요 원인 중 하나이다. 이에 따라 레이아웃 관련 연구들은 사이트 수준에서 이뤄지는 자원의 이동 및 운반을 최소화하기 위한 관리 기술과 기법들을 개발하기 위해서 노력하였다. 더불어 건축물이 대형화되고 평면이 복잡해지면서 작업층 내 레이아웃 연구의 필요성도 제기되었으나, 현재 건물 내부 자재 이동 및 운반에 대한 최적화 연구는 활발히 이루어지지 않고 있는 실정이다. 따라서 본 연구에서는 유전 알고리즘을 이용하여 작업층 내 마감 자재의 위치를 최적화할 수 있는 모델을 개발하였다. 구축된 모델은 복잡한 건축 평면 위에서 다양한 자재들의 배치를 계획할 수 있으며, 이때 모델로부터 도출된 최적화된 자재 배치 계획은 작업 당일 작업자에 의한 총 자재 운반 시간을 최소화할 수 있다. 또한 작업과 자재 간 운반거리를 현실적으로 산정하기 위해서 실제 운반 거리 개념을 적용하였다. 개발된 모델의 적용성을 확인하고 기존 방법론과의 비교/분석을 위해서 실제 고층 주상복합 아파트를 대상으로 모델을 적용하였다.

• 대한조선학회논문집
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• 제47권1호
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• pp.58-66
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• 2010

Topology design optimization is a method to determine the optimal distribution of material that yields the minimal compliance of structures, satisfying the constraint of allowable material volume. The method is easy to implement and widely used so that it becomes a powerful design tool in various disciplines. In this paper, a large-scale topology design optimization method is developed using the efficient adjoint sensitivity and optimality criteria methods. Parallel computing technique is required for the efficient topology optimization as well as the precise analysis of large-scale problems. Parallelized finite element analysis consists of the domain decomposition and the boundary communication. The preconditioned conjugate gradient method is employed for the analysis of decomposed sub-domains. The developed parallel computing method in topology optimization is utilized to determine the optimal structural layout of human powered vessel.

• 수산해양기술연구
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• 제31권3호
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• pp.287-295
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• 1995

fishing boat is a specialized vessel which is intended to perform certain well defined tasks. Its size, deck-layout, carrying capacity and equipment are all related to its function in carrying out its planned operations. Therefore the process of fishing boat design is inherently combined with optimization of the design variables called the economic optimization criteria. Optimization then is a process in which minimum value of weight or cost is established through evaluation of consecutive designs in which one or more design parameters are varied. This paper is to study the basic-design of Stow-net fishing vessel in the Mok-Po region. The main task is developed the preliminary design model of engineering economic system in order to use optimization techniques from operation research the design problem needs to be expressed in terms of objective function and numerous constrains like : speed, fish hold capacity, fishing range, displacement and weight, ratio of main dimensions, etc. The objective function represents the criterion which is NPV such as the ratio of revene/cost. When using computers of limited capacity like P/C, the developed basic-design model of the economic optimization procedure must be simplified to V, Cb, L/B, Dv, Db and less than 15 constraint equations. The main conclusions of this study have attempted to show that economic considerations are essential in Stow-net fishing vessel basic design and operations, and that techno-economic evaluation is an important tool for the design of Stow-net fishing vessel in 69ton and 79ton.

• 한국산학기술학회논문지
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• 제10권9호
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• pp.2179-2182
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• 2009

최근, 광학기계시스템에 새로운 구조 모델은 저비용, 고성능 및 품질의 개념설계에서 출발해야 할 필요성이 있다. 이런 관점에서, 기계적 구조의 개념설계와 연관된 구조적-위상적 형상은 구조적 강성과 감량과 같은 시스템 성능에 큰 영향을 끼친다. 본 연구에서는, 최적설계방법이 대구경 구조물의 설계단계에 제시되었다. 먼저, 위상 최적화법을 이용하여 구조물의 최적 배열과 보강방안을 얻었고, 사이즈 최적화와 다분야 최적기법을 사용한 세부 설계를 수행하였다. 그 일례로, 이 방법들을 대구경 구조물 설계에 적용하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.44-51
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• 2019

Designing sophisticate ship structures that satisfy several design criteria simultaneously with minimum weight and cost is an important engineering issue. For a ship structure composed of a shell and stiffeners, this issue is more serious because their mutual effect has to be addressed. In this study, a two-stage optimization method is proposed for the conceptual design of stiffeners in a ship's prow. In the first stage, a topology optimization method is used to determine a potential stiffener distribution based on the optimal results, whereupon stiffeners are constructed according to stiffener generative theory and the material distribution. In the second stage, size optimization is conducted to optimize the plate and stiffener sections simultaneously based on a parametric model. A final analysis model of the ship-prow structure is presented to assess the validity of this method. The analysis results show that the two-stage optimization method is effective for stiffener conceptual design, which provides a reference for designing actual stiffeners for ship hulls.

• Steel and Composite Structures
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• 제44권5호
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• pp.603-617
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• 2022

Structural design, in general, is developed through trial and error technique which is guided by standards criteria and based on the intuition and experience of the engineer, a context that leads to structural over-dimensioning, with uneconomic solutions. Aiming to find the optimal design, structural optimization methods have been developed to find a balance between cost, structural safety, and material performance. These methods have become a great opportunity in the steel structural engineering domain since they have as their main purpose is weight minimization, a factor directly correlated to the real cost of the structure. Assuming an objective function of minimum weight with stress and displacement constraints provided by Brazilian standards, the present research proposes the sizing optimization and combined approach of sizing and shape optimization, through a software developed to implement the Simulated Annealing metaheuristic algorithm. Therefore, two steel plane frame layouts, each admitting four typical truss geometries, were proposed in order to expose the difference between the optimal solutions. The assessment of the optimal solutions indicates a notable weight reduction, especially in sizing and shape optimization combination, in which the quantity of design variables is increased along with the search space, improving the efficiency of the optimal solutions achieved.

• Journal of Power Electronics
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• 제17권2호
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• pp.411-421
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• 2017

An approach based on a 2D lumped model is presented to quantify the voltage transfer gain (VTG) in power converter low power planes. The advantage of the modeling approach is the ease with which typical noise reduction devices such as decoupling capacitors or ferrite beads can be integrated into the model. This feature is enforced by a new modular approach based on effective matrix partitioning, which is presented in the paper. This partitioning is used to decouple power plane equations from external device impedance, which avoids the need for rewriting of a whole set of equation at every change. The model is quickly solved in the frequency domain, which is well suited for an automated layout optimization algorithm. Using frequency domain modeling also allows the integration of frequency-dependent devices such inductors and capacitors, which are required for realistic computation results. In order to check the precision of the modeling approach, VTGs for several layout configurations are computed and compared with experimental measurements based on scattering parameters.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1995년도 한-중 국제학술회의 발표논문
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• pp.51-59
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• 1995

본문재이달성진해금후도시객운교통적발전응주족우대용량、쾌원환유궤지공신적기출 진,종분석,해기유철로추뉴선재성시범권내적력장포국화현실공능유충,탐계료철로추뉴선재학보상항대외대교통주요공능적전제하,위괄응본해도시교통발전적수요,여하통과알 잠개조,재객경,밀집、류향매녕、원정교장적지구,장부분기유지면철로선개조성고가유궤 성시쾌속전혹,절실퇴해승차난적모순,촉진도시교통향현대화방향발전작출핵만.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.185-191
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• 2008

Optimal damping layout of the constrained viscoelastic damping layer on beam is identified with temperatures by using a gradient-based numerical search algorithm. An optimal design problem is defined in order to determine the constrained damping layer configuration. A finite element formulation is introduced to model the constrained layer damping beam. The four-parameter fractional derivative model and the Arrhenius shift factor are used to describe dynamic characteristics of viscoelastic material with respect to frequency and temperature. Frequency-dependent complex-valued eigenvalue problems are solved by using a simple re-substitution algorithm in order to obtain the loss factor of each mode and responses of the structure. The results of the numerical example show that the proposed method can reduce frequency responses of beam at peaks only by reconfiguring the layout of constrained damping layer within a limited weight constraint.