• 한국전기전자재료학회논문지
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• 제21권10호
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• pp.875-880
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• 2008

In this paper, we deal with the TLP evaluation results for GGNMOS in ESD protection device of conventional CMOS process. An evaluation parameter for GGNMOS is that repeatability evaluation for reference device($W/L=50\;{\mu}m1.0\;{\mu}m$) and following factors for design as gate width, number of finger, present or not for N+ gurad -ring, space of N-field region to contact and present or not for NLDD layer. The result of repeatability was showed uniformity of lower than 1 %. The result for design factor evaluation was ; 1) gate width leading to increase It2, 2) An increase o( finger number was raised current capability(It2), and 3) present of N+ gurad-ring was more effective than not them for current sink. Finally we suggest the optimized design conditions for GGNMOS in evaluated factor as ESD protection device of conventional CMOS process.

• 한국전기전자재료학회논문지
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• 제29권2호
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• pp.75-78
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• 2016

This research was designed 700 level power MOSFET for smart LED driver ICs package. And we analyzed electrical characteristics of the power MOSFET as like breakdown voltage, on-resistance and threshold voltage. Because this research is important optimal design for smart LED ICs package, we designed power MOSFET with design and process parameter. As a result of this research, we obtained $60{\mu}m$ N-drift layer depth, 791.29 V breakdown voltage, $0.248{\Omega}{\cdot}cm^2$ on resistance and 3.495 V threshold voltage. We will use effectively this device for smart LED driver ICs package.

• Tribology and Lubricants
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• 제18권2호
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• pp.127-132
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• 2002

The Taguchi method, a robust experimental design, was used to optimize manufacturing parameters of a brake lining during hot pressing and heat treatment. A friction material containing 15 ingredients was employed fur this experiment and friction and wear tests were carried out by using a pad-on-disk type tribotester. Sixteen brake linings with different manufacturing conditions were examined according to a parameter design. From the results of the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA), the cause and effect of the manufacturing parameters on physical properties (hardness and porosity) and friction and wear characteristics of brake linings was obtained.

• 한국의류학회지
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• 제24권5호
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• pp.714-723
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• 2000

The purpose of this study is to develop functional and sensible brassiere for middle-aged women. As a methodology, engineering design process, especially, QFD(Quality Function Deployment) was adopted to translate consumer's needs into product design parameters. Wearing tests of commercial brassiere were performed for the development o subjective measurement scale. The environmental condition was controlled at 28$\pm$1$^{\circ}C$, 65$\pm$3%RH. As results, subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. Regression equations with the subjective evaluation descriptors were developed for the prediction of wearing comfort of brassiere. (R2=.82) The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap.

• Structural Engineering and Mechanics
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• 제19권1호
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• pp.1-20
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• 2005

The expertise required in the judicious use of nonlinear finite element (FE) packages for design-assistance purposes is not widely available to the average engineer, whose sole aim may be to obtain an estimate for a single design parameter, such as the limit load capacity of a structure. Such a parameter may be required for the design of a proposed reinforced concrete (RC) floor slab or bridge deck with a given set of geometrical and material details. This paper outlines a procedure for developing design-assistance equations for carrying out such predictions for partially restrained RC slabs under uniformly distributed loading condition, based on a database of FE results previously generated from a large number of 'numerical model' slabs. The developed equations have been used for predicting the peak loads of a number of experimental RC slabs having varying degrees of edge restraints; with results showing a reasonable degree of accuracy and low level of scatter. The simplicity of the equations makes them attractive and their successful use in the field of application reported in this paper suggest that the outlined procedure may also be extended to other classes of concrete structures.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.951-954
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• 2010

There are lots of soft ground improvement methods which is consist of different materials. In the analysis and design, composite ground method is usually regarded. Composite ground method considers the area replacement ratio as a key parameter to combine the physical and mechanical characteristics of tow different material. In this study, using composite material consist of three different materials which have different diameters, series of specific gravity test were performed according to KS F 2308, to investigate the applicability of composite ground method. As a result, it is found that composite material which is consist of fine grained soil and granular soil has a high applicability of composite ground method. This result means that, in estimating of ground properties of composite material which is consist of similar fine grained material such as cement mixing etc., composite ground method has a less applicability.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1235-1242
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• 2006

Viscoelastic damping materials are widely used to reduce noise and vibration because of its low cost and easy implementation, for examples, on the body structure of passenger cars, air planes, electric appliances and ships. To design the damped structures, the material property such as elastic modulus and loss factor is essential information. The four-parameter fractional derivative model well describes the nonlinear dynamic characteristics of the viscoelastic damping materials with respect to both frequency and temperature with fewer parameters than conventional spring-dashpot models. However the identification procedure of the four-parameter is very time-consuming one. An efficient identification procedure of the four-parameters is proposed by using an FE model and a gradient-based numerical search algorithm. The identification procedure goes two sequential steps to make measured FRFs coincident with simulated FRFs: the first one is a peak alignment step and the second one is an amplitude adjustment. A numerical example shows that the proposed method is efficient and robust in identifying the viscoelastic material parameters of fractional derivative model.

• 제어로봇시스템학회논문지
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• 제5권8호
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• pp.923-931
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• 1999

In this paper, a modeling and a robust time-delay control for the reclaimer are investigated. Supplying the same amount of a raw material throughout the reclamation process from the raw yard to a sinter plant is important to keep the quality of the molten steel uniform in blast furnaces. As the actual parameter values of the reclaimer are not available, the boom rotational dynamics are modeled as a second order differential equation with unknown coefficients. The unknown parameters in the nominal model are estimated using a recursive estimation method. Another important factor in the control design of the reclaimer is the large time-delay in output measurement. Assuming a multiplicative uncertainty, that accounts for both the unstructured uncertainty neglected in the modeling and the structured uncertainty contained in the parameter estimation, a robust Smith predictor is designed. A robust stability criterion for the multiplicative uncertainty is also derived. Following the work of Goodwin et al. [4], a quantifying procedure of the multiplicative uncertainty bound, through experiments , is described. Experimental and simulation results are provided.

• 한국공작기계학회논문집
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• 제15권3호
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• pp.8-16
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• 2006

This paper discusses design sensitivity analysis and its application to a structural dynamics modification. Eigenvalue derivatives are determined with respect to the element parameters, which include intrinsic property parameters such as Young's modulus, density of the material, diameter of a beam element, thickness of a plate element, and shape parameters. Derivatives of stiffness and mass matrices are directly calculated by derivatives of element matrices. The first and the second order derivatives of the eigenvalues are then mathematically derived from a dynamic equation of motion of FEM model. The calculation of the second order eigenvalue derivative requires the sensitivity of its corresponding eigenvector, which are developed by Nelson's direct approach. The modified eigenvalue of the structure is then evaluated by the Taylor series expansion with the first and the second derivatives of eigenvalue. Numerical examples for simple beam and plate are presented. First, eigenvalues of the structural system are numerically calculated. Second, the sensitivities of eigenvalues are then evaluated with respect to the element intrinsic parameters. The most effective parameter is determined by comparing sensitivities. Finally, we predict the modified eigenvalue by Taylor series expansion with the derivatives of eigenvalue for single parameter or multi parameters. The examples illustrate the effectiveness of the eigenvalue sensitivity analysis for the optimization of the structures.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.104-111
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• 2006

The non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by material tests which are uni-axial tension and bi-axial tension. The computer simulation using the nonlinear element analysis program executed to predict and evaluate the load capacity and stiffness for chevron spring. In order to investigate the heat-aging effects on the rubber material properties, the acceleration test were carried out. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful life prediction for rubber material were proposed.