• Journal of Korean Society of societal Security
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• v.4 no.1
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• pp.49-55
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• 2011

The primary objective of this paper is to develop optimal algorithms of reinforced concrete frame structural systems by the limit state design(CP 1110) and to look into the possibility of detailed design of these structural systems. The structural formulation is derived on the finite element method. The objective of optimization of a reinforced structure for a specified geometry is mainly to determine the optimum cross-sectional dimensions of concrete and the area of the various sizes of the reinforcement required for each member. In addition to the detail s such as the amount of web reinforcement, cutoff points of longitudinal reinforcedments etc. are also considered as design variables. In this study, the method of "Generalized Reduced Gradient, Rounding and with Neighborhood search" and "the Sequential Linear Programming" are employed as an analytical method of nonlinear optimization.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.417-422
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• 2009

The injection mold cooling circuit optimization was studied with a response surface method in the previous research. It took so much time to find an optimum solution for a large product due to an extensive amount of calculation time for the CAE analysis. In order to use the optimization technique in the actual design process, the calculation time should be much reduced. In this study, we tried to reduce the number of design variables with the concept of the close relationship between the depth and the distance of cooling channel. The optimum ratio of the distance to the depth of cooling channels for a 2-dimensional problem was 2.0 so that the optimum ratio was again sought out for 4 large automotive parts. Therefore, the number of design variables for the cooling circuit optimization can be reduced in half, resulting in much faster running time for the optimization as a design tool.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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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

• Journal of the Society of Naval Architects of Korea
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• v.53 no.6
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• pp.503-513
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• 2016

In order to reduce the green-house gas exhaustion, International Maritime Organization (IMO) has been reinforcing carbon gas regulations. Due to the regulations, a lot of competitions for designing Eco ship in the shipbuilding industry are progressing now. It is faced with the necessity of reducing hull weight by combining automated systems for optimal compartment arrangement with hull structural design. Most researches on optimum structural design method have been consistently in progress and applied to minimize weight and cost of mid-ship section in preliminary ship design stage based on analytical structural analysis method on fixed compartment arrangement. In order to reduce design period and to improve international technical competitiveness by shortening the period of hull structural design and enhancing design accuracy, it has been felt necessity to combine optimized compartment arrangement with optimum design of ship structure based on the international regulations and rules. So in this study, the automated design algorithm for longitudinal members has been developed to combine automated algorithm of compartment arrangement with hull structural design system for oil tanker. The SeaTrust-Hullscan software developed by Korean Register is used to perform ship structural design for mother ship and selected design cases. The effect of weight reduction is verified with comparison of ship weight between mother ship and the cases suggested in this study.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.784-791
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• 2013

Recent advanced IT made layout design fast and accurate by using algorithms. Layout design should be determined by considering the position of equipment with satisfying various space constraints and its component works with optimum performance. Especially, engine room layout design is performed with mother ship data, theoretical optimal solution, design requirements and several design constraints in initial design stage. Piping design is affected by position of equipment seriously. Piping design depends on experience of designer. And also piping designer should consider correlation of equipment and efficiency of space. In this study, space evaluation method has been used to evaluate efficiency of space. And also this study suggested object function for optimal piping route, Average Reservation Index(ARI), Estimated Piping Productivity(EPP) and with modified space evaluation method. In this study, optimum pipe routing system has been developed to reflect automated piping route with space efficiency and experience of piping designer. Engine room is applied to the design of the piping in order to confirm validity of the developed system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.11
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• pp.1889-1896
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• 2003

In the microfluidic applications, viscous-driven pumping mechanism is a promising one since the viscous effect increases significantly as the size of device decreases, relative to the inertial effect. However, there exist a few drawbacks we have to improve such as low efficiency and small volume flow rate. In the present study, an optimum design synthesis is proposed to enhance the performance characteristics of the micropump with single rotating cylinder. First, the unstructured grid CFD method is described and validated by comparing its results to the previous results. Next, an automated optimum design synthesis tool is constructed by combining the aforementioned CFD analysis model with the mathematical optimization model. This technique is used to improve the performance characteristics of newly designed viscous-driven pump. The presented results show that the fluid dynamic optimization tool is robust and may be applied to other microfluidic device design applications.

• Journal of the Korean Institute of Navigation
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• v.21 no.4
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• pp.1-9
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• 1997

A study on theergonomic design of the automated ship's bridge and console layout was carried out through this paper. The goal of this study is to find out the effective and ergonomic optimal design solutions of bridge layout hence to reduce the duty officier's workload and increase the safety of navigation. The conventional bridge layouts and modernized Integrated bridge layouts were compared using several factors. To use human factors, an ergonomic control panel layout system based on constraint satisfaction algorithm wa squoted. And the integrated ergonomic bridge layout was converged and applied to the redesign of the navigational console layout.

• Korean Journal of Computational Design and Engineering
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• v.17 no.5
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• pp.364-374
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• 2012

In this paper, we proposed a data structure to represent structural components of solid rocket motors (SRM) in an automated design program. To propose the data structure, we searched the necessary functions for the automated design program should have. In order to design the structural components of solid rocket motors sufficiently with a design program, it should have the functions to represent the shapes of the components, the drawing and analysis models, the design variables, various product structures, interferences, characteristic properties, design equations, and tightening sets. By modifying the data structure of an element object that is a general purpose data structure to represent a general component of a product, a new data structure was proposed to satisfy all the necessary functions with optimum. Finally, a design program for the structural components of solid rocket motors was developed successfully with the proposed data structure.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1151-1157
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• 2009

Ensuring both product quality and reducing material cost are important issue for the design of the piping system of an air conditioner outdoor unit. This paper describes a shape optimization that achieves mass reduction of an air conditioner piping system while satisfying two design constraints on resonance avoidance and the maximum stress in the pipes. In order to obtain optimized design results with various analysis fields considered simultaneously, an automated multidisciplinary analysis system was constructed using PIAnO v.2.4, a commercial process integration and design optimization(PIDO) tool. As the first step of the automated analysis system, a finite element model is automatically generated corresponding to the specified shape of the pipes using a morphing technique included in HyperMesh. Then, the performance indices representing various design requirements (e.g. natural frequency, maximum stress and pipe mass) are obtained from the finite element analyses using appropriate computer-aided engineering(CAE) tools. A sequential approximate optimization(SAO) method was employed to effectively obtain the optimum design. As a result, the pipe mass was reduced by 18 % compared with that of an initial design while all the constraints were satisfied.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.235-239
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• 2009

As robotic technologies have become more actively utilized to automate many construction tasks, they have been able to improve the construction productivity, quality, and worker's safety on site. A new advanced system, Robot-based Construction Automation (RCA) system, is currently being developed. To accomplish RCA system effectively, Design for automation (DFA) should be performed in automation system developing phase. The performance criteria of this system are a major cause of design changes. It is required exhaustive review for development new system. This research analyzed the design changes of Climbing Hydraulic Robot system and Construction Factory (CF), being currently developed in the field of applied RCA systems. And the design change matters according to performance criteria in each system's design-by-step were analyzed. The purpose of this research is developing the performance criteria in the developing phase of RCA system, and then will be served as basis for system design in similar projects.