• Journal of Korean Association for Spatial Structures
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• v.4 no.3 s.13
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• pp.77-84
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• 2004

This study presents an effective stiffness-based optimal technique to control quantitatively lateral drift for tall frameworks using composit member subject to lateral loads. To this end, displacement sensitivity depending on behavior characteristics of tall frameworks is established and approximation concept that preserves the generality of the mathematical programming and can efficiently solve large scale problems is introduced. Specifically, under the 'constant-shape' assumption, resizing techniqe of composite member is developed. Two types of 50 story frameworks are presented to illustrate the features of the quantitative lateral drift control technique proposed in this study.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.566-570
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• 1986

본 논문의 목적은 대규모 선형 시불변 계통에 대한 합성 제어기의 설계에 관한 새로운 방법을 제시하기 위한 것이다. 주어진 계통을 행렬 부호 함수를 이용하여 그 고유치의 크기에 따라 블럭 대각 분해하고 각부 계통에 대한 최적 제어기 및 전체계통에 대한 준최적 합성 제어기를 설계한다. 이 방법은 주어진 계통의 고유치를 미리 알 필요가 없으며 계통의 블력 분해 과정에서 Riccati 방정식및 Lyapunov 방정식의 해를 구할 필요가 없고 특이섭등 기법이나 Two time scale seperation 방법에서의 제약조건에 관계없이 광범위하게 적용되는 장점이 있다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.136-143
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• 1996

본 연구에서는 정유공정의 한 부부인 demethanizer의 core exchanger 주위 열교환기들에 대해 핀치설계법(pinch desgin method)을 이용하여 새로운 열교환망 합성을 수행하였다. 이로부터 초기에 설정했던 최소접근온도차가 총비용, 즉, 장치비와 에너지 비용에 결정적인 역할을 하는 것으로 확인되었다. 따라서, 본 연구에서는 이 총비용의 목표값이 최소가 되는 최적 최소접근온도차가 존재하고, 이로부터 열교환망 합성이 수행되어져야 최적의 열교환망 합성이 이루어져야 한다는 결론을 얻었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.135-142
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• 2008

This study is concerned with the optimum design of LB-Deck plate girder bridge. The optimizing problems of the composite bridge are formulated with objective functions and constraints. The objective functions are formulated as the total cost of the concrete deck and steel girder construction and the constraints are derived by criteria with respect to the Korean Highway bridge design. The optimizing algorithm using SUMT for optimum design of the Simple span, 2-Span, 3-span LB-deck plate and general RC-steel composite girder bridges (L=60m) which act live load(DB24). And their optimum numerical results are compares and analyzed to examine the possibility of optimization, the application and convergency of this optimizing algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.823-830
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• 2015

Structural optimization pursues improved performance of structures. Nowadays, structural optimization is applied to the design of huge and complex structures such as an airplane. As the number of the finite elements is increased, the analysis solution becomes more accurate. However, the design cost using the finite element model is significantly increased. The component mode synthesis method that is using the substructure synthesis method is frequently employed in order to keep the accuracy and reduce the cost. A new design method for structural optimization is proposed to reduce the design cost and to consider the dynamic effect of the structure. The proposed method reduces the design cost by applying the equivalent static loads on the design domain. An example of linear dynamic response optimization is solved and the efficiency of the proposed method is demonstrated.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.125-135
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• 1998

This study presents a design method for three-span continuous preflex composite girder bridges (3S-PCB) which imposes prestresses in the negative moment region by lifting or lowering interior supports and the design method is automated by a computer program which incorporates optimal design procedure. The objective function for the design of 3S-PCB minimizes the cost of construction materials and the constraint functions represent the limited dimensions of the design section and the allowable stress for each structural member as given in the specifications. Optimal design procedure used in this study is a modification of existing sequential unconstrained minimization technique (SUMT), a numerical analyses procedure for two-span continuous preflex composite bridges. The optimized design sections determined for each span length are compared with those of simple preflex composite beams (SPCB) and the optimal girder depth is determined by defining the relationship between girder depth and construction material costs.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.212-215
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• 2009

요구되는 접착력과 그라프트율을 만족시킬 수 있는 변성폴리프로필렌의 제조 기술 확립을 목표로 변성폴리프로필렌의 최적 합성을 위한 과산화물, 변성폴리프로필렌의 최적 합성을 위한 촉매 및 반응몰비, 변성폴리프로필렌의 최적 합성을 위한 반응온도, 반응시간 확립을 통한 변성 PP 제조기술을 개발하였으며, $90{\Phi}$ extruder에서 상업 생산을 위한 공정 제어 기술 확립과 접착력과 그라프트율 등을 나타내는 변성폴리프로필렌의 최적 합성 조건 확립을 통한 폴리프로필렌 엘라스토머 복합수지용은 물론 강관 코팅용, 시트 및 필름용 등의 변성 폴리프로필렌 제조기술을 개발하였다. 이들 변성 PP를 활용하여 매트릭스 및 필러, 분산 조건 변경 시험, 엘라스토머 폴리프로필렌 컴파운드 최적 분산 조건 확립, 엘라스토머 폴리프로필렌 컴파운드 pilot 생산 및 제품 분석을 통하여 초고강성 범퍼, 룸미러 케이스 소재, 인패널, 도어용으로 사용될 수 있는 자동차 부품용 폴리프로필렌 복합수지 개발을 완료하였다.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.3
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• pp.30-35
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• 2011

This study investigates the optimum section properties of newly developed steel-concrete composite beam. For that purpose we developed computer program calculating section properties. The suggested new beam section highly contribute to save inter-story height and reduce construction duration and cost compared with conventional steel works such as H-beam and column + RC slab system. But the section shape have different section modulus with upper and lower fiber because of the unsymmetric cross section. Therefore the parametric study on thickness-ratio of top and bottom flange plate is needed. In this paper the change of neutral axis and section modulus for thickness-ratio of up and down flage plate is analysed and discussed.

• Journal of the Korean Vacuum Society
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• v.12 no.1
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• pp.25-34
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• 2003

Deposition behavior of hard amorphous carbon film was investigated by molecular dynamic simulation using Tersoff potential which was suggested for the interaction potential between carbon atoms. When high energy carbon atoms were collided on diamond (100) surface, dense amorphous carbon film could be obtained. Physical properties of the simulated carbon film were compared with those of the film deposited by filtered cathodic arc process. As in the experimental result, the most diamond-like film was obtained at an optimum kinetic energy of the incident carbon atoms. The optimum kinetic energy was 50 eV, which is comparable to the experimental observation. The simulated film was amorphous with short range order of diamond lattice. At the optimum kinetic energy condition, we found that significant amount of carbon atom were placed at a metastable site of distance 2.1 $\AA$. By melting and quenching simulation of diamond lattice, it was shown that this metastatic peak is Proportional to the quenching rate. These results show that the hard and dense diamond-like film could be obtained when the localized thermal spike due to the collision of high energy carbon atom can be effectively dissipated to the lattice.

• Explosives and Blasting
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• v.27 no.1
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• pp.38-46
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• 2009

Recently, as a reduction method of vibration and noise, an electronic detonation which has an accuracy of time and a freedom of input delay time was introduced. A waveform composition program can determine a delay time and accomplish simulation under environment similar to real blast using a delay time. In this study, optimum delay time which controls vibration is obtained and real measurement vibration level is estimated by a waveform composition program.