• 대한토목학회논문집
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• 제6권4호
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• pp.69-78
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• 1986

본 연구에서는 earth dam의 파괴로부터 야기되는 유출수문곡선을 유도하고, 홍수파가 자연하도를 통하여 하류로 전파되어 나가는 과정을 추적하기 위하여 dynamic wave equation을 구성하고, 이 식을 Preissmann scheme과 double sweep법을 이용하여 해석하는 DBF(Dam Break Floodwave) 요형을 개발하였다. 본 모형을 Teton dam에 적용하여 댐 파괴로 인한 홍수파의 첨두수위, 청두유량, 도달시간 및 범람 범위 등을 계산하였고, 실측자료와의 비교검토를 통하여 본 모형의 적용성을 입증하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 추계학술대회 논문집
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• pp.64-67
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• 1995

Transfer Molding is currently the most widely used process for encapsulation integrated circuits(;IC). Although the process has been introduced over 20 years ago, generating billions of parts each year, it is far from being optimized. With each new mold, epoxy mold, epoxy mold compound, and lead-frame, lengthy period and expensive qualification runs have to be performed to minimized defects ranging from wire sweep, incomplete fill, and internal voids etc. This studies describes how simulation can be applied to transfer molding to yield acceptable design and processing parameter. The non-isothermal filling of non-newtonian reactive epoxy molding compound(;EMC) in a multi-cavity mold is analyzed. Sensitivity analysis is conducted to investigate the influence of process deviations on the final molded profile. This study trend is carried out by following some heuristic process guidelines.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.347-356
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• 2004

The flexural vibration characteristics of a sandwich beam system with a partially inserted viscoelastic layer were quantitatively studied using the finite element analysis in combination with the sine-sweep experiment. Asymmetric mode shapes of the flexural vibration were visualized by holographic interferometry, which agreed with those obtained by the finite element simulation. Effects of the length and the thickness of the partial viscoelastic layer on the system loss factor (η$\_$s/) and resonant frequency (f$\_$r/) were significantly large for both the symmetric and asymmetric modes of the beam system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.525-532
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• 2005

Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using response surface method and three-dimensional Navier-Stokes analysis. Three design variables of blade sweep. lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor. the adiabatic efficiency is increased by reducing the tub comer and tip losses. Separation line due to the interference between a passage shock and surface boundary layer on the blade suction surface is moved downstream for the optimized blade compared to the reference one.

• International Journal of Aeronautical and Space Sciences
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• 제2권1호
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• pp.1-11
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• 2001

The time implicit point SGS scheme is applied to compute hypersonic viscous flows in thermochemical nonequilibrium. The performance of the point SGS scheme is then compared with those of the line SGS and the LU-SGS schemes. Comparison of convergence histories with the effect of multiple forward and backward sweeps are made for the flow over a 2D cylinder experimentally studied by Hornung and the flow over a hemisphere at conditions corresponding to the peak heating condition during the reentry flight of an SSTO vehicle. Results indicate that the point SGS scheme with multiple sweeps is as robust and efficient as the line SGS scheme. For the point SGS and the LU-SGS scheme, the rate of improvement in convergence is largest with two sweep cycles. However, for the line SGS scheme, it is found that more than one sweep cycle deteriorates the convergence rate.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.472-475
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• 2014

Abnormal cab vibrations in the Y direction in commercial vehicles during driving(70~90kph) are not common vibrations that happen to vehicles during driving and can be an obstacle to normal driving. This study conducted Operation Deflection Shape(ODS) testing to identify the causes of those abnormal cab vibrations and find solutions for them and also a sine sweep test to find resonance and frequency in the cab suspension system and set directions for improvement. The study also altered the shape of the bush inner part for changes to the rigidity features of the cab bush in the Y direction and revised the design with optimal rigidity in the Y direction, thus improving abnormal cab vibrations in the Y direction during driving.

• 한국산업융합학회 논문집
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• 제7권1호
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• pp.33-39
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• 2004

Viscous flows around a cooling tower fan with sweep are numerically investigated. The Navier-Stokes equations and the continuity equation are solved in the flow domain. The Reynolds stresses are modelled using the $\kappa-{\varepsilon}$ turbulence model. The governing equations are discretized with the Finite Volume Method. The pressure and the velocity are linked with the SIMPLE algorithme. Flow and pressure characteristics around the fan are investigated. The pressure sharply increases through the fan. Pressure variations on the pressure and suction sides of the fan are well represened in the calculations. The flow streamlines in the blade passage are nearly parallel to the blade.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.401-403
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• 2001

This paper describes a power flow method for distribution systems, applying the method of symmetrical component to back/forward sweep method. The proposed algorithm is effective for unbalanced radial distribution system, with process of AVR(Auto Voltage Regulator), shunt capacitor. The proposed method was compared with the conventional Back/forward sweep method by using three phase unbalanced distribution systems of 123 nodes.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.578-582
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• 2004

This paper presents the response surface optimization method using three-dimensional Navier-Stokes Analysis to optimize the shape of a axial flow fan. Reynolds-averaged Navier-Stokes equations with k-$\epsilon$ turbulence model are discretized with finite volume approximations. Regression analysis is used for generating response surface, and it is validated by ANOVA. Five geometric variables, i.e., distribution of sweep angle at mean and tip, lean angle at mean and tip, and spanwise location of mean were employed to optimize the efficiency. The computational results are compared with experiment data. As a main result of the optimization, the efficiency was successfully improved.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.123-123
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• 2008

본 논문에서는 Cu의 ECMP 적용을 위해 $HNO_3$ 전해액의 active, passive, transient, trans-passive 영역을 I-V 특성 곡선을 통해 알아보았고, LSV (Linear sweep voltammetry)와 CV (Cyclic voltammetry)법을 통하여 전기화학적 특성을 비교 분석하였다.