• Title/Summary/Keyword: optimal surface development

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Optimal Approximated Development of General Curved Plates Based on Deformation Theory (변형 이론을 기반으로한 곡면의 최적 근사 전개)

  • 유철호;신종계
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.3
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    • pp.190-201
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    • 2002
  • Surfaces of many engineering structures, specially, those of ships and airplanes are commonly fabricated as doubly curved shapes as well as singly curved surfaces to fulfill functional requirements. Given a three dimensional design surface, the first step in the fabrication process is unfolding or planar development of this surfaces into a planar shape so that the manufacturer can determine the initial shape of the flat plate. Also a good planar development enables the manufacturer to estimate the strain distribution required to form the design shape. In this paper, an algorithm for optimal approximated development of a general curved surface, including both singly and doubly curved surface is developed in the sense that the strain energy from its planar development to the design surface is minimized, subjected to some constraints. The development process is formulated into a constrained nonlinear programming problem, which is on basis of deformation theory and finite element. Constraints are subjected to characteristics of the fabrication method. Some examples on typical surfaces and the practical ship surfaces show the effectiveness of this algorithm.

Improved Optimal Approximated Unfolding Algorithm of a Curved Shell Plate with Automatic Mesh Generation (자동 메쉬 생성을 적용한 향상된 자유 곡면의 최적 근사 전개 알고리즘)

  • Ryu C.H.;Shin J.G.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.3
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    • pp.157-163
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    • 2006
  • Surfaces of many engineering structures, especially, those of ships are commonly made out of either single- or double-curved surfaces to meet functional requirements. The first step in the fabrication process of a three-dimensional design surface is unfolding or flattening the surface, otherwise known as planar development, so that manufacturers can determine the initial flat plate which is required to form the design shape. In this paper, an algorithm for optimal approximated development of a general curved surface, including both single- and double-curved surfaces, is established by minimizing the strain energy of deformation from its planar development to the design surface. The unfolding process is formulated into a constrained nonlinear programming problem, based on the deformation theory and finite element. Constraints are subjected to the characteristics of the fabrication method. And the design surface, or the curved shell plate is subdivided by automatic mesh generation.

Optimal Search Pattern of Ships based on Performance Surface (음향 탐지 성능 분포도 기반에서 함정 최적탐색패턴에 관한 연구)

  • Cheon, Minki;Kim, Sunhyo;Choi, Jee Woong;Choi, Cheolwoo;Son, Su-Uk;Park, Joungsoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.3
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    • pp.328-336
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    • 2017
  • The goal of this study is simulation of optimal search pattern of ships based on performance surface which are reflected underwater environmental. The process is as follows. First, temporal and spatial environmental database are extracted in complex environment and input hull mounted SONAR system parameters. The environmental database and SONAR system parameters are substituted to SONAR equations, and calculate signal excess, detection probability, detection range. And then, the performance surface, which can be used to provide operational insight of SONAR detection performance, are pictorialized. Finally, optimal search pattern of ships are simulated using genetic algorithm based on performance surface. And then, we certify optimal search pattern in various ways.

Optimal Design of the Monolithic Flexure Mount for Optical Mirror Using Response Surface Method (반응표면법을 이용한 광학미러용 일체형 유연힌지 마운트 최적설계)

  • Kyoungho Lee;Byounguk Nam;Sungsik Nam
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.3
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    • pp.205-213
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    • 2023
  • An optimal design of a simple beam-shaped flexure hinge mount supporting an optical mirror is presented. An optical mirror assembly is an opto-mechanically coupled system as the optical and mechanical behaviors interact. This side-supporting mount is flexible in the radial direction and rigid for the remaining degrees of freedom to support the mirror without transferring thermal load. Through thermo-elastic, optical and eigenvalue analysis, opto-mechanical performance was predicted to establish the objective functions for optimization. The key design parameters for this flexure are the thickness and length. To find the optimal values of design parameters, response surface analysis was performed using the design of experiment based on nested FCD. Optimal design candidates were derived from the response surface analysis, and the optimal design shape was confirmed through Opto-mechanical performance validation analysis.

A Study on Optimal Operation against Anti-Air Missiles with Consideration of Anti-Surface Missile Kill Probability (대함유도탄 요격 확률을 고려한 함정 대공방어유도탄의 최적 운용 연구)

  • Park, Hyeonwoo;Lee, Hanmin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.6
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    • pp.815-823
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    • 2019
  • A naval surface-to-air missile is an effective countermeasure against increasing threats of anti-ship missiles. Optimal operation is imperative for high survivability due to limited defense resources of a warship. This paper addresses a problem of optimal engagement to maximize the overall probability of intercept under Shoot-Look-Shoot tactics. The problem is formulated and analyzed with consideration of a realistic single-shoot probability model. The analysis shows that a global solution is achieved for some engagement scenarios. A numerical algorithm to optimize the overall probability of intercept is suggested. An illustrative example is provided to verify our results.

Minimum Time Regulation of DC-DC Converters in Damping Mode with an Optimal Adjusted Sliding Mode Controller

  • Jafarian, Mohammad Javad;Nazarzadeh, Jalal
    • Journal of Power Electronics
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    • v.12 no.5
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    • pp.769-777
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    • 2012
  • In this paper, a new development in the time optimal control theory in sliding mode control systems for multi-quadrant buck converters with a variable load is presented. In general, the closed-loop time optimal control system is applied to multi-quadrant buck converters for output regulation, so that an optimal switching surface is obtained. Moreover, an adjusted optimal sliding mode controller is suggested which adjusts the controller parameters to give an optimal switching surface. In addition, a description of the transient response of the closed-loop system is proposed and used to damp any output or input disturbances in minimum time. Numerical simulations and experimental results are employed to demonstrate that the output regulation time and transient performances of dc/dc converters using the proposed technique are improved effectively when compared to the classical sliding mode control method.

Development of Algorithm for Optimal Operation of Surface Mounters (표면실장기의 최적 운영을 위한 모델링 및 알고리듬 개발)

  • Lee, Young-Hae;Kim, Jeong
    • Journal of Korean Institute of Industrial Engineers
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    • v.20 no.3
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    • pp.79-92
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    • 1994
  • Surface mount technology has been evolving in the electronics industries. Efficient operation of surface mounters is closely related with the productivity of the electronic products. In this study, modeling and optimal algorithm for allocating feeders and sequencing mounting jobs in the rotary type surface mounter, which consider all the constraints, in the hardware and are easy to be used in the field, are developed.

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Optimal Deployment of Sensor Nodes based on Performance Surface of Acoustic Detection (음향 탐지 성능지표 기반의 센서노드 최적 배치 연구)

  • Kim, Sunhyo;Kim, Woojoong;Choi, Jee Woong;Yoon, Young Joong;Park, Joungsoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.5
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    • pp.538-547
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    • 2015
  • The goal of this study is to develop an algorithm to propose optimal deployment of detection sensor nodes in the target area, based on a performance surface, which represents detection performance of active and passive acoustic sonar systems. The performance surface of the active detection system is calculated from the azimuthal average of maximum detection ranges, which is estimated with a transmission loss and a reverberation level predicted using ray-based theories. The performance surface of the passive system is calculated using the transmission loss model based on a parabolic equation. The optimization of deployment configurations is then performed by a hybrid method of a virtual force algorithm and a particle swarm optimization. Finally, the effectiveness of deployment configurations is analyzed and discussed with the simulation results obtained using the algorithm proposed in this paper.

Optimization of the High-Pressure Condition for Rice Protein Extracting Using Response Surface Methodology (RSM) (반응표면분석법을 이용한 쌀 단백질 초고압 추출조건 최적화)

  • Ra, Ha-Na;Park, Sa-Ra;Kim, Ha-Yun;Cho, Yong-Sik;Kim, Kyung-Mi
    • Journal of the Korean Society of Food Culture
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    • v.34 no.6
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    • pp.779-784
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    • 2019
  • The purpose of this study was to optimize the rice protein extracted using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the high pressure (X1, 0-400 MPa) and processing time (X2, 0-10 minutes). The results of the extraction content (Y1), residue content (Y2), and recovery yield (Y3) were fitted to a response surface methodology model (R2= 0.92, 0.92, and 0.93, respectively). Increasing the pressure and processing time has a positive effect on the extraction content (Y1), residue content (Y2), and recovery yield (Y3). Therefore, these high-pressure conditions (independent variables) can significantly affect the improvement in rice protein extraction efficiency. Thus, the optimal conditions of X1 and X2 were 400 MPa and 10 min., respectively. Under these optimal conditions, the predicted values of Y1, Y2, and Y3 were 62.93, 57.53 mg/g, and 91.76%, respectively.

Optimization of the Manufacturing Process for Mandarin Dry Chip Using Response Surface Methodology (RSM) (반응표면분석법을 이용한 감귤건조칩 제조조건 최적화)

  • Ra, Ha-Na;Park, Ga-Yeong;Kim, Ha-Yun;Cho, Yong-Sik;Kim, Kyung-Mi
    • Journal of the Korean Society of Food Culture
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    • v.34 no.5
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    • pp.637-644
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    • 2019
  • The purpose of this study was to optimize the mandarin dry chip manufacturing using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the drying temperature ($X_1$, $50-90^{\circ}C$), drying time ($X_2$, 12-36 hours), and microwave pretreat time ($X_3$, 0-4 minutes). The results of appearance ($Y_5$), color ($Y_6$), taste ($Y_8$) and overall acceptance ($Y_{10}$) were fitted to the response surface methodology model ($R^2=0.86$, 0.88, 0.89, and 0.84, respectively). Increasing the drying temperature and microwave treatment time were negatively evaluated for consumer acceptance. On the other hand, a high value of consumer acceptance was evaluated when the drying time was more than 24 hr. Therefore, the optimal conditions of $X_1$, $X_2$, and $X_3$ were $52.989^{\circ}C$, 24 hr, and 1 min, respectively. Under these optimal conditions, the predicted values of $Y_5$, $Y_6$, $Y_8$, and $Y_{10}$ were 5.066, 5.338, 5.063, and 5.339, respectively.