• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.461-468
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• 2004

Modal participation factor(MPF) is essential to analyze structural response under earthquake load. MPF of real structure differs from that of analytic mathematical model due to the error induced from analytical assumption and construction. In this study, a identification method is proposed to calculate the MPF of real structure based on H∞ optimal model reduction. The MPF is obtained from the relationship between observability, controllability matrix of realized from S.I. and typical 2-degree state space model. The proposed method is verified thorough examples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.100-102
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• 1992

Optimal generation dispatch algorithm is developed using L.P and load dispatch method. The algorithm is composed with three steps. Fist phase, analytical algorithm is adopted to solve to minimize quadratic cost functions which fits well for planning purpose. Second phase uses L.P method for obtain economic redispatch that satisfies line constraints. When there is no solution whitch satisfy line constraints load shedding algorithm solves the problem.

• 대한화학회지
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• 제68권1호
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• pp.20-24
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• 2024

This article presents the advantages of utilizing gossypol and its derivatives as reagents for iron (III) (Fe (III)) ions. A novel spectrophotometric method has been developed for the determination of Fe (III) using gossypol derivatives in the presence of a universal buffer solution. Optimal conditions have been identified, and the composition and stability constants of the Fe (III) complex with gossypolacetic acid have been determined.

• Advances in Computational Design
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• 제4권1호
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• pp.15-32
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• 2019

One of the efficient and useful tools to achieve the optimal design of structures is employing the sensitivity analysis in the finite element model. In the numerical optimization process, often the semi-analytical method is used for estimation of derivatives of the objective function with respect to design variables. Numerical methods for calculation of sensitivities are susceptible to the step size in design parameters perturbation and this is one of the great disadvantages of these methods. This article uses complex variables method to calculate the sensitivity analysis and combine it with discrete sensitivity analysis. Finally, it provides a new method to obtain the sensitivity analysis for linear structures. The use of complex variables method for sensitivity analysis has several advantages compared to other numerical methods. Implementing the finite element to calculate first derivatives of sensitivity using this method has no complexity and only requires the change in finite element meshing in the imaginary axis. This means that the real value of coordinates does not change. Second, this method has the lower dependency on the step size. In this research, the process of sensitivity analysis calculation using a finite element model based on complex variables is explained for linear problems, and some examples that have known analytical solution are solved. Results obtained by using the presented method in comparison with exact solution and also finite difference method indicate the excellent efficiency of the proposed method, and it can predict the sustainable and accurate results with the several different step sizes, despite low dependence on step size.

• 지식경영연구
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• 제13권5호
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• pp.43-64
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• 2012

Emerging technologies have significant implications in establishing competitive advantages and are characterized by continuous rapid development. Efficient benchmarking is more and more important in the development of emerging technologies. Similar input level and importance are two necessary criteria need to be considered for emerging technology's benchmarking. In this study, we proposed a sequential use of self-organizing map(SOM), data envelopment analysis(DEA) and analytical hierarchy process(AHP) method for the stepwise benchmarking of emerging technology. The proposed method uses two-level SOM to cluster the emerging technologies with similar required input levels together, then, in each cluster, uses DEA-BCC model to evaluate the efficiencies of the emerging technologies and do tier analysis to form tiers. On each tier, AHP rating method is used to calculate each emerging technology's importance priority. The optimal benchmarking path of each cluster is established by connecting the emerging technologies with the highest importance priority. In order to validate the proposed method, we apply it to a case of biotechnology. The result shows the proposed method can overcome difficulties in benchmarking, select suitable benchmarking targets and make the benchmarking process more efficient and reasonable.

• 경영과학
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• 제31권3호
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• pp.61-76
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• 2014

There are three methods for calculating the optimal level for spare part inventories in a MIME (Multi Indenture and Multi Echelon) system : marginal analysis, Lagrangian relaxation method, and genetic algorithm. However, their solutions are sub-optimal solutions because the MIME system is neither convex nor separable by items. To be more specific, SRUs (Shop Replaceable Units) are required to fix a defected LRU (Line Replaceable Unit) because one LRU consists of several SRUs. Therefore, the level of both SRU and LRU cannot be calculated independently. Based on the limitations of three existing methods, we proposes a improved algorithm applying marginal analysis on determining LRU stock level and genetic algorithm on determining SRU stock level. It can draw optimal combinations on LRUs through separating SRUs. More, genetic algorithm enables to extend the solution search space of a SRU which is restricted in marginal analysis applying greedy algorithm. In the numerical analysis, we compare the performance of three existing methods and the proposed algorithm. The research model guarantees better results than the existing analytical methods. More, the performance variation of the proposed method is relatively low, which means one execution is enough to get the better result.

• 한국산업보건학회지
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• 제19권2호
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• pp.81-87
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• 2009

Final purpose of this study was designed to develop the quality control(QC) sample for proficiency analytical testing of asbestos. This study consisted of two parts; first, development of manufacturing apparatus and sample preparing procedure for asbestos quality control(QC) sample: second, validation of the QC samples made by our developed method as asbestos proficiency analytical testing sample. The main results of the first part research are as followed We developed the apparatus for manufacturing the asbestos QC sample, consisted of filter hold, filter holder manifolder, vacuum system, and vacuum pump. The most proper filter of making the QC samples was a cellulose ester membrane filter with 25 mm diameter, pore size 0.8 um. And we presented the optimal procedure for preparing the asbestos QC sample by using the developed apparatus. We will verify the manufactured asbestos QC samples by this method, and present the validation results to confirm the reliability as a asbestos QC sample in next paper.

• Korean Chemical Engineering Research
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• 제59권1호
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• pp.100-105
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• 2021

본 연구는 적은 비용으로 분석 장치 없이 질병 진단 및 경과를 모니터링할 수 있는 종이-기반 분석 장치(paper-based analytical device, PAD)를 제작하기 위해 polydimethylsiloxane (PDMS) 블레이드 코팅 방법을 제안하였다. PAD 디자인은 레이저 커팅 기술로 쉽게 몰드에 적용할 수 있으며, 제작된 몰드로 블레이드 코팅을 수행하여 완전한 소수성 장벽 형성에 필요한 조건을 확립하였다. 코팅 조건인 잉크의 두께와 종이와의 접촉시간에 따라 PDMS 소수성 장벽의 구조와 친수성 채널의 크기 변화를 분석하여 안정적으로 소수성 장벽을 형성할 수 있는 조건을 최적화하였다. 최적화된 방법을 바탕으로 PAD를 제작하여 특별한 분석기기 없이 단백질, 당, 메탈이온을 검출하여 바이오센서에 응용가능함을 증명하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.833-847
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• 2021

The horizontal porous baffle and its effect as an anti-slosh device have been investigated intensively in a swaying and rolling rectangular tank. To accurately assess the level at which porous baffles reduce liquid sloshing, the Matched Eigenfunction Expansion Method (MEEM) has been utilized as an analytical tool. The velocity potentials in the horizontal baffle-covered fluid region are expressed by the sum of the homogeneous and particular solutions to avoid solving the complex dispersion equation. By applying an equivalent linearized quadratic loss model, the nonlinear algebraic equation is derived and solved by implementing the Newton-Raphson iterative scheme. To prove the validity of the present theoretical model, a series of experiments have been conducted with different centered horizontal porous baffles with varying porosities and submerged depths in a swaying and rolling rectangular tank. Reasonably good agreements are obtained regarding the analytical solutions and the experiment's findings. The influence of porosity, submerged depth, and length of a centered horizontal porous baffle on anti-slosh performance have been analyzed, especially at resonance modes. The developed predictive tool can potentially provide guidelines for optimal design of the horizontal porous baffle.

• 마이크로전자및패키징학회지
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• 제8권4호
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• pp.35-41
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• 2001

본 연구에서 솔더 접합부의 최적 형상을 예측하는 몇 가지 방법에 대하여 연구하였다. 솔더 접합부 형상 예측법에는 Truncated Sphere법, 힘-평형 해석법(force-balanced analytical method), Ken Brakke에 의해 개발된 Surface Evolver등이 있다. 이상의 형상 예측법 붕 본 연구에서는 Truncated Sphere 법과 SurfaceEvolver를 사용하여 $\mu$BGA치 솔더 접합부의 형상을 예측하고, 결과를 비교하였다. 그 결과 Truncated Sphere법과 SurfaceEvolve가 제시하는 두 가지의 형상은 아주 작은 오차를 두고 거의 일치함을 확인하였다. 또한, 형상 예측법이 제시한 형상의 신뢰성을 검증하기 위하여, FEA 프로그램인 ANSYS(version5.62)를 이용하여 대상 형상에 열 사이클 시험을 실시하였다. 해석 결과, 형상 예측법이 제시한 형상이 임의 오차를 가한 다른 형상에 비하여 가장 좋은 신뢰성을 나타냄을 확인할 수 있었다.