• Computational Structural Engineering : An International Journal
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• 제2권1호
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• pp.11-17
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• 2002

Cost-effectiveness in design is considered for determining the target reliability of concrete bridges under seismic actions. This objective can be achieved based on the economic optimization of the expected life-cycle cost of a bridge, which includes initial cost, direct losses, and indirect losses of a bridge due to strong earthquakes over its lifetime. A separating factor is defined to consider the redundancy of a transportation network. The Park-Ang damage model is employed to define the damage of a bridge under seismic action, and a Monte Carlo method based on the DRAIN-2DX program is developed to assess the failure probability of a bridge. The results for an example bridge analyzed in this paper show that the optimal target failure probability depends on the traffic volume carried by the bridge and is between 1.0×10/sup -3/ to 3.0×10/sup -3/ over a life of 50 years.

• 한국농공학회지
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• 제26권2호
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• pp.97-105
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• 1984

We have, at present, found some studies on the optimum design of reinforced concrete about the simple slab but very few about the multi-story and multi-span slab. The aim of this study is to make a optimum design of coalesced beam and column slab constructure. Some results of the evaluation by using the optimalized algorithm that was developed in this study are as follows. 1. Slab was mainly restricted by the constraint of effective depth, bending moment, and minimum steel ratio; especially the effective depth was the preceding crifical constraint. In the optimum design of slab, therefore, the constraint about the minimum thickness should be surely considered. 2. This optimum design is good economy as much as some 3.4&~6.2% compared with the conventional design method. 3. In most case, it was converged by 3 to 6 iteratin regardless of the highest or lowest value and only in case of N=1 and case 1, there is a little oscillation after the 3rd iteration but it makes no difference in taking either the highest or lowest value because the range of oscillation is low as much as about 1.2% of the total construction cost. 4. In this study the result seeking for constraints that make no difference in the least cost design shows that shear stress and maximum steel ration may not be considered in it. 5. Bending moment was converged by one time iteration regardless of the initial value, while steel ratio, in most case, by two times because both bending moment and steel ratio are the fuction of effective depth.

• 한국산업융합학회 논문집
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• 제15권1호
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• pp.37-42
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• 2012

Trends in semiconductor equipment industry are to reduce the cost of producing semiconductor, semiconductor process development, facility development, and the minimum investment in terms of cost and quality. Semiconductor equipments are being considered to review and development is proceeding at the same time. In the first part of the semiconductor assembly process, in which the importance of die bonding process is emerging, a wide leadframe type die bonding machine is demanded for productivity. Die bonding machine was designed through experiments and by trial and error. It costs a lot of time and financial burden. The purpose of this study is to solve these problems by using the CAE tool 3G. By using finite element method, thermal analysis of die bonding machine to the various widths leadframe die bonder machine rail is performed for design.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.176-183
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• 1999

This paper describes the application of discretized continuum-type optimality criteria (DCOC) for the reinforced concrete continuous beams. The cost of construction as objective function which includes the costs of concrete, reinforced steel, formwork is minimized. The design constraints include limits on the maximum deflection in a given span, on bending and shear strengths, optimality criteria is given based on the well known Kuhn-Tucker necessary conditions, followed by an iterative procedure for designs when the design variables are the depth and the steel ratio. The self-weight of the beam is included in the equilibrium equation of the real system. Two numerical examples of reinforced concrete continuous beams with rectangular cross-section are solved to show the applicability and efficiency for the DCOC-based technique

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 International Symposium
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• pp.109-119
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• 2003

o In order to start SIP Project .Marketing (& ASIC team) should present biz planning, schedule, device/SIP specs., in SIP TFT prior to request SIP development for package development project. .In order to prevent (PCB) revision, test, burn-in, & quality strategy should be fixed by SIP TFT (PE/Test, QA) prior to request for PKG development. .Target product price/cost, package/ test cost should be delivered and reviewed. o Minimum Information for PCB Design, Package Size, and Cost .(Required) package form factor: size, height, type (BGA, QFP), Pin count/pitch .(Estimated) each die size including scribe lane .(Estimated) pad inform. : count, pitch, configuration(in-line/staggered), (open) size .(Estimated) each device (I/O & Core) power (especially for DRAM embedded SIP) .SIP Block diagram, and net-list using excel sheet format o Why is the initial evaluation important\ulcorner .The higher logic power resulted in spec. over of DRAM Tjmax. This caused business drop longrightarrow Thermal simulation of some SIP product is essential in the beginning stage of SIP business planning (or design) stage. (i.e., DRAM embedded SIP) .When SIP is developed using discrete packages, the I/O driver Capa. of each device may be so high for SIP. Since I/O driver capa. was optimized to discrete package and set board environment, this resulted in severe noise problem in SIP. longrightarrow In this case, the electrical performance of product (including PKG) should have been considered (simulated) in the beginning stage of business planning (or design).

• 설비공학논문집
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• 제25권8호
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• pp.464-470
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• 2013

Economic feasibility was conducted regarding the regulation that dictates obligatory installation of renewable energy facilities in small proportion. A concern is how to allocate the capacities of candidate facilities (solar collectors, PV cells and geothermal heat pumps) with minimum cost, and meet the obligatory energy supply proportion. A design rule has been developed, with which a designer can tune his or her design strategy between installation cost and LCC. This was derived mainly from documents regarding the KEMCO installation guide. It was concluded that PV was the cheapest, with respect to installation cost, but a geothermal heat pump was the most recommended, when LCC was also taken into account. The proposed design result was also confirmed, by simulation results obtained from Energy Plus.

• Structural Engineering and Mechanics
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• 제81권1호
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• pp.93-102
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• 2022

The optimum design of reinforced concrete cantilever retaining walls subjected to seismic loads is an extremely important challenge in structural and geotechnical engineering, especially in seismic zones. This study proposes an adaptive sperm swarm optimization algorithm (ASSO) for economic design of retaining structure under static and seismic loading. The proposed ASSO algorithm utilizes a time-varying velocity damping factor to provide a fine balance between the explorative and exploitative behavior of the original method. In addition, the new method considers a reasonable velocity limitation to avoid the divergence of the sperm movement. The proposed algorithm is benchmarked with a set of test functions and the results are compared with the standard sperm swarm optimization (SSO) and some other robust metaheuristic from the literature. For seismic optimization of retaining structures, Mononobe-Okabe method is employed for dynamic loading conditions and total construction cost of the structure is considered as the single objective function. The optimization constraints include both geotechnical and structural restrictions and the design variables are the geometrical dimensions of the wall and the amount of steel reinforcement. Finally, optimization of two benchmark retaining structures under static and seismic loads using the ASSO algorithm is presented. According to the numerical results, the ASSO may provide better optimal solutions, and the designs obtained by ASSO have a lower cost by up to 20% compared with some other methods from the literature.

• 한국전산구조공학회논문집
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• 제15권2호
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• pp.281-291
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• 2002

본 연구에서는 직사각형 단면을 갖는 프리스트레스 철근콘크리트보(PRC)의 최소경비설계를 수행하였다. 목적함수로서 건설경비는 콘크리트 경비, 긴장재 경비, 철근 경비 그리고 거푸집 경비를 포함하였으며 이를 최소화하였다. 설계제약조건으로는 시방서상의 최대처짐제약, 휨 및 전단강도제약, 연성제약 그리고 설계변수에 대한 상·하한 제약을 고려하였다. 쿤-터커 필요조건을 이용하여 최적성 규준을 설계변수의 항으로 명시적으로 유도하였으며, 이때 설계변수로는 보의 유효깊이, 긴장재의 최대편심거리 그리고 철근비로 취하였고, 긴장재의 형상은 2차 포물선함수로 가정하였다. 또한 본 연구에서는 요소별로 변화하는 단면을 갖는 경우와 전경간에 걸쳐 일정한 단면을 갖는 경우에 대하여 고려하였고, 긴장재의 경간별 최대편심을 설계변수화 하였다. 그리고 수치예를 들어 개발된 기법의 적용성과 효율성을 보였다.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.315-324
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• 2003

If an optimum design technique is applied in the design of packaging container for bulk-type products, merits on the side of not only economic and compression performance but distribution efficiency are expected. Accordingly, minimum board area (mRBA), compression strength (CS) and compression strength per unit area (mCSPA) are important design parameters in optimum design of packaging container for bulk-type products. In this study, mathematical models for mRBA, CS and mCSPA of container as algorithm for optimum design program were developed. In order to develop these models, compression test by various dimensions of container and response surface analysis for mRBA, CS, and mCSPA of container were carried out. In the developed models, volume, W/L ratio and depth of container were principal independent variables. On the found of these models, optimum design program having faculties of outward and inward optimum design and information design was developed. Though the packaging specifications are same, required board area, board combination and cost of the corrugated board required container manufacture were greatly different by boundary conditions in outward design. Moreover, about 6.3∼10.1% in weight of container was lighter, and about 13.2∼25.6% in cost of container was reduced when the program was applied for 2 kinds of bulk-type products.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.262-271
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• 1998

Recent, more and more steel deck bridges are adopted for the design of long span bridges and the upgrading of existing concrete deck bridges, mainly because of reduced self weight, higher stiffness and efficient erection compared to concrete decks. The main objective of this study is to propose on formulation of the design optimizations to develop an optimal desist program required for optimum desist for orthotropic steel-deck bridges. The objective function of the optimization is formulated as a minimum initial cost design problem. The behavior and design constraints are formulated based on the ASD and LRFD criteria of the Korean Bridge Design Code(1996). The optimum design program developed in this study consists of two steps. In the first step the system optimization of the steel box girder bridges is carried out. And in the second step the program provided the optimum design of the orthotropic steel-deck with close ribs. In the optimal design program the analysis module for the deck optimization is based on the Pelican Esslinger method. The optimizer module of the program utilizes the ADS(Automated Desist Synthesis) routines using the optimization techniques fuor constrained optimization. From the results of real application examples, The cost effectiveness of optimum orthotropic steel-deck bridges designs based on both ASD and LRFD methods is investigated by comparing the results with those of conventional designs, and it may be concluded that the design developed in this study seems efficient and robust for the optimization of orthotropic steel-deck bridges