• Journal of computational fluids engineering
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• v.17 no.4
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• pp.56-68
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• 2012

Nowadays, Unmanned Combat Air Vehicle(UCAV) has become an important aircraft system for the national defense. For its efficiency and survivability, shape optimization of UCAV is an essential part of its design process. In this paper, shape optimization of UCAV was processed for aerodynamic performance improvement and Radar Cross Section(RCS) reduction using Multi Objective Genetic Algorithm(MOGA). Lift and induced drag, friction drag, RCS were calculated using panel method, boundary layer theory, Physical Optics(PO) approximation respectively. In particular, calculation applied Radar Absorbing Material(RAM) was performed for the additional RCS reduction. Results are indicated that shape optimization is performed well for improving aerodynamic performance, reducing RCS. Further study will be performed with higher fidelity tools and consider other design segments including structure.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.61
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• pp.1-11
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• 2000

Ergonomic vehicle design is very important for driver's safety and sensibility. Many studies have emphasized the physical factors of human operator and usability of control devices. However, driver's cognitive factors such as the shape of cognitive map have not been well documented. The aim of this research is to find the relationship between the shape of Instrument Pane (IP) in driver's cognitive map and the real vehicle. To do this, Sketch Map Method (SMM), that is an extraction method of cognitive map, was employed to extract the shape of middle-aged driver's cognitive map. In this study, SMM was modified to formulate driver's cognitive map because this process is not being in the existing SMM. Next, correlation was analyzed between individual cognitive map and the shape of real vehicle's IP. The result showed that the position of volume control switch and cigar jack was similar between these but the position of others wasn't.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.5
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• pp.482-490
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• 2009

In this paper, the author proposes a new method for acoustic radiation optimum design to minimize noise from a vibrating panel-like structure using a collaborative population-based search method called the particle swarm optimization algorithm(PSOA). The PSOA is a parallel evolutionary computation technique initially developed by Kennedy and Eberhart. The acoustic radiation optimization method based on the PSOA consists of two processes. In the first process, the acoustic radiation analysis by an integrated p-version FEM/BEM, which was developed by using MATLAB, is performed to evaluate the exterior acoustic radiation field of the panel. The second process is to search the optimum design variables: 1) Shape of Bezier curves and 2) Shape and position of ribs, to minimize noise from the panel using the PSOA. The optimization method based on the PSOA is compared to that based on the steady state genetic algorithm(SSGA) in order to verify the effectiveness and validity of the optimal solution by PSOA. Finally, it is shown that the optimal designs of the panel obtained by using the PSOA can achieve effective reductions in radiated sound power.

• Smart Structures and Systems
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• v.20 no.5
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• pp.595-605
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• 2017

The present article reported the thermal buckling strength of the sandwich shell panel structure and subsequent improvement of the same by embedding shape memory alloy (SMA) fibre via a general higher-order mathematical model in conjunction with finite element method. The geometrical distortion of the panel structure due to the temperature is included using Green-Lagrange strain-displacement relations. In addition, the material nonlinearity of SMA fibre due to the elevated thermal environment also incorporated in the current analysis through the marching technique. The final form of the equilibrium equation is obtained by minimising the total potential energy functional and solved computationally with the help of an original MATLAB code. The convergence and the accuracy of the developed model are demonstrated by solving similar kind of published numerical examples including the necessary input parameter. After the necessary establishment of the newly developed numerical solution, the model is extended further to examine the effect of the different structural parameters (side-to-thickness ratios, curvature ratios, core-to-face thickness ratios, volume fractions of SMA fibre and end conditions) on the buckling strength of the SMA embedded sandwich composite shell panel including the different geometrical configurations.

• Transactions of Materials Processing
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• v.15 no.3 s.84
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• pp.241-246
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• 2006

The isotropic steel sheet was developed and started to apply on the auto-body outer panel, however the characteristics of application on auto-body were not well known. In this paper the FE analysis of outer panel of auto-body was carried out to investigate the characteristics of isotropic steel sheet. For the FE analysis of the roof panel of ULSAB body the isotropic steel sheet and the bake hardening steel sheet were used. The Isotropic steel sheet shows more deformation at punch bottom area of roof panel than the bake hardening steel sheet that is most required forming properties far outer panel to obtain the shape likability of forming parts. It is shown that the isotropic steel sheet has suitable material properties far outer panels of auto-body.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1053-1054
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• 2012

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.453-458
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• 2001

Analysis of radiation heating system for producing 60" size PDP panels was carried out using $RADCAD^{TM}$ software. Optimum arrangement of infrared heating elements was found to obtain uniform temperature distribution in PDP panel during heating. Heating capacity of each heater was determined to obtain an appropriate maximum panel temperature. Parametric study to find the effect of design parameters such as the thermophysical and optical properties of glass and cooling system was carried out. As a reference system, about 35 kW heating capacity was chosen to obtain about 800 K maximum panel temperature after 30 minute heating. The maximum temperature difference in panel was below 20 K. The maximum/minimum and its difference in the panel were very sensitive to the variation of the emissivity of glass and cooling block.

• Korean Journal of Computational Design and Engineering
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• v.18 no.2
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• pp.113-119
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• 2013

This paper proposes an approach to detect unintended deflections in an automotive outer panel. Conventionally, the detection of unintended deflections has been performed by experienced works, and it requires much amount of time and efforts. The motivation of this work is to reduce such efforts by providing an automated detection methodology. For the detection of unintended deflections, we make use of the measured data from an optical scanner which can be considered as a Z-map data. The proposed approach consists of four major steps; 1) measured data acquisition for an automotive outer panel, 2) identification of shape features, 3) removal of shape features, and 4) detection of unintended deflections via curvature analysis.

• Transactions of Materials Processing
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• v.10 no.4
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• pp.283-293
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• 2001

Laser welded tailored blanks(TB) are increasingly used in automotive parts. Among these, TB side panel has forming difficulties in stretch flanging areas such as front and center pillar lower region. To avoid splits in the stretch flanging areas, Proper design of blank shape and drawbeads are essential In this study, the forming simulaton is carried out to investigate the influences of blank shape and drawbeads on stretch flange formability of different thickness TB. And an optimization procedure including the effects of both the blank design and drawbeads is presented. The optimization procedure proposed in this study is expected to be effectively used in blank and die design of TB side panel.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1211-1221
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• 2002

A shape optimization of stiffener was conducted to increase buckling load or failure load with stiffened laminated composite panel of I-type under compression loading. Design variables are cap length, web length, and/or thickness under the constraint of volume constancy. The objective function is buckling load and failure load of post-buckling based on Tsai-Hill theory using ABAQUS 5.8 for analysis and Optimizer on Broydon-Fletcher Goldfarb-Sharno Method and Augmented Lagrange Multiplier Method. The effects of relative length of a web and a cap of stiffener on buckling load and failure load of post-buckling were investigated with the results of optimum design.