• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.187-194
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• 2004

The structural behavior of superstructure by ILM is strongly dependent on the process of launching nose according to the construction process. The ratios of length, weight, and flexural stiffness of launching nose to those of superstructure are taken as the analysis parameters in this study. The interaction behaviors are analyzed according to the variation of parameters. Design formulas to pursue the optimum values for length, weight, and stiffness of launching nose are suggested through the parametric study. As a result, the minimum stiffness ratio is analyzed as I₂/I=0.045 and I₁/I=0.02 for the optimum track of the sectional force while the elastics modulus ratio is 6.8359. Additionally, the design results of real projects are analyzed by the developed formulas to verify that they are designed well in structurally optimal point of view.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.876-883
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• 2002

Electric vehicle body has to be subjected to uniform load and requires auxiliary equipment such as air pipe and electric wire pipe. Especially, the cross beam supports the weight of passenger and electrical equipments. a lightweight vehicle body is salutary to save operating costs and fuel consumption. Therefore this study is to perform the size and the shape optimization of crossbeam fur electric vehicle using the method of topology optimization to introduce the concept of homogenization based on optimality criteria method which is efficient for the problem having the number of design variables and a few boundary condition. this provides the method to determine the optimum position and shape of circular hole in the cross beam and then can achieve the optimal design to reduce weight.

• Coupled systems mechanics
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• v.11 no.3
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• pp.259-266
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• 2022

Non-Traditional Optimization methods are successfully used in solving many engineering problems. Shaft is one of important element of machines and it is used to transmit power from a machine which produces power to a machine which absorbs power. In this paper, ten non-traditional optimization methods that are ALO, GWO, DA, FPA, FA, WOA, CSO, PSO, BA and GSA are used to find minimum weight of hollow shaft to get global optimal solution. The problem has two design variables and two inequality constraints. The comparative results show that the Particle Swarm Optimization outperforms other methods and the results are validated using ANSYS.

• Journal of Ocean Engineering and Technology
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• v.20 no.3 s.70
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• pp.7-14
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• 2006

This paper discusses the structural design and analysis of a 6,000 meters depth-rated capable deep-sea unmanned underwater vehicle (UUV) system. The UUV system is currently under development by Maritime and Ocean Engineering Research Institute(MOERI), Korea Ocean Research and Development Institute (KORDI). The UUV system is composed of three vehicles - a Remotely Operated Vehicle (ROV), an Autonomous Underwater Vehicle (AUV) and a Launcher - which include underwater equipment. The dry weight of the system exceeds 3 tons hence it is necessary to carry out the optimal design of structural system to ensure the minimum weight and sufficient space within the frame for the convenient use of the embedded equipments. In this paper, therefore, the structural design and analysis of the ROV and launcher frame system were carried out, using the optimizing process. The cylindrical pressure vessels for the ROV were designed to resist the extreme pressure of 600 bars, based on the finite element analysis. The collapse pressure for the cylindrical pressure vessels was also checked through a theoretical analysis.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.10
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• pp.685-691
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• 2015

In this work, to identify effective parameter for performance of piezoelectric jetting dispenser, experimental investigation is carried out based on design of experiment. After preparing jetting dispenser using two stack-type piezoelectric actuators, basic working principle of the jetting dispenser is described. Eight operating conditions are chose as main factors and it is assumed that each factor has two levels. To reduce number of experiments for performance evaluation, the experimental sets are designed based on factional factorial design method. Experimental setup is established and the weight of single dot is measured by using precision scale. The main and interaction effects of factors are analyzed using commercial statistical program and optimal operating condition for small amount and small variation of weight of dispensed single dot are determined.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.65-71
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• 2019

The development of adsorbed natural gas (ANG) has emerged as one of potential solutions. It is desirable to reduce the weight of vessel by applying light-weighed a composite carbon fiber in order to response to a egulation of $CO_2$ emission. Through understanding of a composite carbon fiber, and material characteristic of a composite carbon fiber is required in order for better application of a reduction of weight and an analysis of material characteristic. Herein, this study suggest the composite carbon fiber vessel applied to the characteristic of carbon fiber, and it decides the preliminary shape based on the test of material characteristic for ANG vessel applied to a composite carbon fiber, and its basic shape calculate through on the netting theory. Moreover, the detail shape design is analyzed by a finite element analysis, and in the stage of detail sahp design and analysis of stress was performed on the typical shape using a finite element analysis, and the result of preliminary design was verified.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.28-35
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• 2000

For the merit of a container in transportation and cargo handling the amount of container freight has been continuously on the increase. On the other hand container crane had got the bottle neck in cargo handling due to low productivity so that freight congestion had been often occurred at ports. in this paper A mathematical model for container crane system is represented a method for designing a fuzzy controller of container crane system for high productivity in cargo handling is presented. The fuzzy controller is compared with other optimal controller at the same condition. in the computer simulation the fuzzy controller obtained an excellent response to reference change better than the optimal controller. For disturbance such as a strong storm and parameter change due to change of cargo weight the result was also stable and robust than the optimal controller.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1012-1015
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• 1996

This study focuses on the optimal operation and control strategy of the fuel cell process. The control objective of the Phosphoric Acid Fuel Cell (PAFC) is established and dynamic modeling equations of the entire fuel cell process are formulated as discrete-time type. On-line optimal control of the MIMO system employs the direct decomposition-coordination method. The objective function is modified as the tracking form to enhance the response capability to the load change. The weight factor matrices Q,R, which are design parameters, are readjusted. This control system is compared with LQI method and the results show that the suggested method is better than the traditional method in pressure difference control.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.515-520
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• 2001

Due to the high power to weight ratio and fast response under heavy load, the hydraulic systems are still applied to the development of many industrial facilities such as heavy duty construction vehicles, aerospace/military weapon actuating systems and motion simulators. Unlike the other actuators, single-rod hydraulic cylinder exhibits a lot different dynamic characteristics between the extending and retracting stroke because of the difference in pressure acting areas. In this research, in order to overcome this nonlinear feature, $H_{\infty}$ optimal controller was designed and implemented with DSP board that was specifically developed for the experiment. From the experimental result, we could confirm that the overall performance of single-rod hydraulic servo system is similar with the results as we expected in the design stage.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.77-84
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• 2004

A robust optimal control design is proposed in this study for rigid robotic systems under the unknown loads and the other uncertainties. The uncertainties are reflected in the performance index, where the uncertainties are bounded for the quadratic square of the states with a positive definite weighting matrix. An iterative algorithm is presented for the determination of the weighting matrix required for necessary robustness. Computer simulations have been done for a weight-lifting operation of a two-link manipulator and the simulation results shows that the proposed algorithm is very effective for a robust control of robotic systems.