• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.2
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• pp.1-8
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• 2006

In this paper, an optimum design technology is developed to find an optimal position of the shock absorber using ADAMS and VisualDOC. A vehicle with a torsion-beam rear suspension is modeled by using ADAMS. Design variables for the optimal positioning of the shock absorber are defined considering the hard points of the chassis structure and design positioning are specified through the sensitivity analysis using a bump-crossing simulation. The objective function is defined as the joint reaction forces of the shock absorber connecting joints of the chassis structure. Sequential Quadratic Programming and Genetic Algorithms are used for this study. To validate the optimized design variables, pothole simulations are performed. GA showed better results than SQP algorithms for this design purpose.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.42 no.6
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• pp.98-101
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• 2013

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.95-100
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• 2012

A deck crane is installed on the deck of a ship when there is no adequate facility for loading and unloading in dock or harbor. Deck cranes in Korea have been imported from abroad, and the import-substitution effect will arise if its production can be localized. Now, it is required to suggest the structural design of a deck crane that meet the domestic criterion, considering loading condition. In this study, the structural analysis of a pedestal in the deck crane was peformed by finite element method to investigate the strength requirement. In addition, the structural design of a pedestal was suggested by using ANSYS and VisualDOC. The optimized structure of a pedestal was determined, considering lightweight design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.6
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• pp.539-544
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• 2013

This study provides a solution method for the inverse heat conduction problem based on a combination of a public domain CAE (computer aided engineering) software and a commercial CAO (computer aided optimization) software. The solver system has been implemented without any in-house coding. The proposed method is simple to implement. Moreover, it can be easily reproduced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.379-385
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• 2013

The tires, suspension type, and steering system can all cause pulling during braking. Among these, a drag link steering system and leaf-type suspension system are significant causes of vehicle pulling. In this study, the pulling problem is analyzed using the vehicle analysis program "ADAMS/CAR." The drag link and leaf spring behavior is analyzed to find the key reason for pulling. After this, the optimization program "Visual DOC" is used with "ADAMS/CAR" to find a steering link connection point to reduce pulling. After conducting this simulation, K&C (kinematic & compliance) test simulation with a modified connection point is conducted to determine whether the vehicle performance improves. Through a full braking simulation, it is verified that the pulling distance is reduced at braking.

• Composites Research
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• v.25 no.6
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• pp.224-229
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• 2012

The structural performance is degraded in case of embedding the array antenna for reconnaissance and surveillance into the wing skin structures. In this paper, the optimal design for the thickness of composite hat-shaped stiffener which is reinforced embedded array antenna on the simplified composite wing box was conducted. To select the basic shape of hat-shaped stiffener, structural analysis was carry out using the commercial finite element analysis program while changing the web slope and flange length of hat-shaped stiffener. The optimal thickness of the composite hat-shaped stiffeners was determined by using commercial optimization program such as VisualDOC and commercial FEA program with considering stresses and buckling constraints.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1215-1220
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• 2014

Breaking time is an important performance indicator of a circuit breaker. Thus, the operating mechanism of the circuit breaker should be optimized for reducing the breaking time. The operating mechanism in a gas circuit breaker is made up of several latches. Specifically, the geometry and relative positions of latches influence the dynamic behaviors of the operating mechanism. In this study, a three-stage latch operating mechanism is analyzed on the basis of the verified multibody dynamics model constructed using the MSC.ADAMS program. The relative positions and lengths of latches are selected as design variables. The dominant design variables are selected by a design study. Optimization is performed using a genetic algorithm (GA). The study results demonstrate that the performance of the circuit breaker improves by about 22.5.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.105-113
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• 2002

As the number of pedestrian accident increases, the reconstruction of an accident becomes important to find the source of the fault. Generally, accidents are reconstructed by the intuition of experts or primitive physics. A reconstruction method is proposed using sophisticated optimization technology. At first, a dynamic simulation model is established for the accident environment. Occupant analysis for automobile crashworthiness is employed. The situation before an accident is identified by optimization. The impact velocity and the position of the pedestrian are utilized as design variables. The design variables are found by minimizing the difference between the simulation and the real accident. The optimization process is performed by linking an occupant analysis program MADYMO to an optimization program VisualDOC. Since the involved analysis is dynamics and highly nonlinear, response surface method is selected for the optimization process. Problems are solved for various situations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.25-30
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• 2014

The dynamic characteristics of a gas circuit breaker depend on the underlying high-speed operating mechanism with a spring-actuated latch system. Many studies have been carried out to reduce the breaking time of circuit breakers. In this study, the optimum latch contour design is determined for reducing the breaking time of a circuit breaker. A multi-body dynamic model of the latch is established for analyzing the dynamic behaviors of the circuit breaker by using the MSC/ADAMS program. Simulation results are matched against experimental data. VisualDoc is employed for determining the optimal latch contour. From the optimum design, the breaking time of a gas circuit breaker is improved by about 8.6%.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.78-83
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• 2010

In the present paper, a flap was optimized to maximize the lift. A 2-element fowler flap system was utilized for optimization with an initial shape of general aviation airfoil and a flap shape designed by Wentz. Response surface method and Hicks-Henne shape function were implemented for optimization. 2-D Navier-Stokes method was used to solve flow field around aGA(W)-1 airfoil with a fowler flap. Commercial programs including Visual-Doc, Gambit/Tgridand Fluent were used. Upper surface shape and the flap gap were optimized and lift for landing condition was improved considerably. The original and optimized flaps were tested in the KARI's 1-m low speed wind tunnel to examine changes in aerodynamic characteristics. For optimized flap tests, the similar trend to prediction could be seen but stall angle of attack was lower than what was expected. Also, less gap than optimized design delayed stall and produced better lift characteristics. This is believed to be the effect of turbulence model.