• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.258-261
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• 2007

The objective of this paper is to examine the ways in which to implement MEPS method for setting the design and operational limits in order to provide the guaranteed performance of the aircraft engine. Direct adder arithmetically added and related with the effects of ambient humidity, engine quality, throttle set tolerance and deterioration, etc is described with the random adder added in root square sum. The method was applied on the preliminary design of 4,000Ib class turbofan engine and the MEPS for engine component design and operational margin was generated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.13-20
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• 1987

Methods of nonlinear structural design sensitivity analysis are developed in parallel with the nonlinear finite element structural analysis methods and numerically evaluated. Direct decomposition and iterative solution methods for the secant stiffness approach and direct use of tangent stiffness in the design sensitivity analysis phase are derived and presented as the methods of nonlinear structural analysis and design sensitivity analysis are closely related. From the considerations of theoretical and numerical behavior, the tangent stiffness approach is shown to be efficient as the intermediate results of structural analysis can be effectively used in the design sensitivity analysis stage.

• Journal of Power Electronics
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• v.19 no.4
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• pp.1000-1010
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• 2019

The use of internal-model-based linear controller, such as resonant controller, is a well-established technique for the current control of grid-connected systems. Attractive properties for resonant controllers include their two-sequence tracking ability, the simple control structure, and the reduced computational burden. However, in the case of continuous-designed resonant controller, the transient performance is inevitably degraded at a low switching frequency. Moreover, available design methods for resonant controller is not able to realize the direct design of transient performances, and the anticipated transient performance is mainly achieved through trial and error. To address these problems, the zero-order-hold (ZOH) characteristic and inherent time delay in digital control systems are considered comprehensively in the design, and a corresponding hold-equivalent discrete model of the grid-connected converter is then established. The relationship between the placement of closed-loop poles and the corresponding transient performance is comprehensively investigated to realize the direct mapping relationship between the control gain and the transient response time. For the benefit of automatic tuning and real-time adaption, analytical expressions for controller gains are derived in detail using the required transient response time and system parameters. Simulation and experimental results demonstrate the validity of the proposed method.

• Structural Engineering and Mechanics
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• v.83 no.4
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• pp.563-576
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• 2022

This study aimed to evaluate the progressive collapse potential of buildings designed using conventional design codes for the merchant occupancy classification and subjected to a sudden column failure. For this purpose, three reinforced concrete buildings having different story numbers were designed according to the seismic design recommendations of TSCB-2019. Later on, the buildings were analyzed using the GSA-2016 and UFC 4-023-03 to observe their progressive collapse responses. Three columns were removed independently in the structures from different locations. Nonlinear dynamic analysis method for the alternate path direct design approach was implemented for the design evaluation. The plasticity of the structural members was simulated by using nonlinear fiber hinges. The moment, axial, and shear force interaction on the hinges was considered by the Modified Compression Field Theory. Moreover, an existing experimental study investigating the progressive collapse behavior of reinforced concrete structures was used to observe the validation of nonlinear fiber hinges and the applied analysis methodology. The study results deduce that a limited local collapse disproportionately more extensive than the initial failure was experienced on the buildings designed according to TSCB-2019. The mercantile structures designed according to current seismic codes require additional direct design considerations to improve their progressive collapse resistance against the risk of a sudden column loss.

• Journal of the Korean Society of Costume
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• v.57 no.2 s.111
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• pp.45-58
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• 2007

This study shows that clothes are made just the same as the real thing in the virtual space through 3D digital technology. This study is significant to expand the area of fashion design in the virtual space. This study analyzes the practical use of the third dimension computer graphics in the aspect of fashion, and it is proposed the 3D fashion design simulation in the virtual space used on 3D studio max, poser, photoshop program according to fashion design process. The main design concept is "temporary bridge" from rainbow. "Temporary bridge" is a rainbow bridge which connects nature, man and technology, and also the past, present, and future. This study is supposed six fashion design in accordance with three sub-theme under main concept by changing rotor and texture used on 3D simulation. The conclusion are as follows : First fashion design process, which consists of design conceptualization, design definition, and computer design process, composed of body modeling, clothing modeling, texture mapping, rendering by lighting and camera establishing are compared. Second, fashion design process is applied to digital technology. Third, the method of body modeling is both that of direct modeling in 3D Studio Max and that of importing DXF file from poser. And the method of direct clothing modeling in 3D Studio Max are two methods, polygon modeling and nurbs modeling. Polygon modeling is more satisfied than nurbs modeling in the aspect of expression to clothing and round face. Forth, this study applies textures and colors transformed by photoshop on manufactured 3D Clothes. According to this result, fashion designers are able to confirm a customer or client in their design minds viewing 3D simulation by various textures. colors and angles. It is able to advance digital fashion show in the future.

• 한국전기화학회:학술대회논문집
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• 2002.10a
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• pp.12-12
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• 2002

• 한국전기화학회:학술대회논문집
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• 2003.10a
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• pp.13-13
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• 2003

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.239-244
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• 2006

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.49-57
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• 2007

Recently, CMOS RF integration has been widely explored in the wireless communication area to save cost, power, and chip area. The direct conversion architecture, rather than a more conventional super-het-erodyne, has been an attractive choice for single-chip integration because of its many advantages. However, the direct conversion architecture has several fundamental problems to solve in achieving performance comparable to a super-heterodyne counterpart. In this paper, we describe a programmable filter for mobile communication terminals using a direct conversion architecture. The proposed filter can be implemented with the active-RC filter and programmed to meet the requirements of different communication standards, including GSM, DECT and WCDMA. The filter can be tuned to select a detail frequency by changing the gate voltage of the MOS resistors. The gain of the proposed architecture can be programmed from 27dB to 72dB using the filter gain and VGA in 3dB steps.

• Journal of Fashion Business
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• v.16 no.1
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• pp.150-159
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• 2012

This study intend to analyze differences between 3D body scanning sizes and direct measurement sizes of same subjects. The subjects of study are female students of university in China. 3D data analyze as a 3D Body Measurement Soft System. The conclusion found is as below: In case of circumferences, error between direct-measurement size and 3D body scanning size is from 4.9mm to 62.2mm. The neck circumference size of directmeasurement is bigger than 3D body scanning size. The height error range is from 0.6mm to 51mm. Height of underbust, waist and hip are that direct-measurement sizes are higher than 3D body scanning sizes. Gap of width is from 3.8mm to 21.9mm. The gap range is too narrow relatively to others. Only direct-measurement size of neck width is wider than 3D body scanning size. Error range of length is from 0.3mm to 41.8mm. 3D body scanning sizes of lateral neck to waistline, upperarm length, arm length, neck shoulder point to breast point, shoulder center point to breast point, lateral shoulder to breast point are longer than direct-measurement sizes. They have a negative margin of error. I intend to set up same measurement point between direct-measurement and 3D body scanning but they have some errors because direct-measurement point is applied by a person. 3D body scanning measurement point is settled by automatic system. A measurement point of direct-measurement and 3D body scanning isn't unite. So we need to make a standard of setting up measurement points.