• 소성∙가공
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• 제14권8호통권80호
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• pp.675-680
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• 2005

This study was aimed at the design of the dies for the automobile part for the engine oil leakage prevention using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation,'eesy-2-form' of 2D FEM simulation package and 'eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the simulation of 'eesy-2-form', we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of 'eesy-DieOpt', we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for cold forging has been developed.

• Journal of Pharmaceutical Investigation
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• 제40권1호
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• pp.1-7
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• 2010

K-$BEtest^{(R)}$ is a well known program for bioequivalence test using a $2{\times}2$ design. Lee et al.(1998) and Park et al.(1999) suggested a $3{\times}3$ and $3{\times}2$ design, and also discussed their benefits. We developed a computer program, called BioEquiv, which can analyze some complex experimental designs such as, $3{\times}3$ design and $3{\times}2$ design including a standard $2{\times}2$ design. This program is a user-friendly one and overcomes the disadvantages of K-$BEtest^{(R)}$. The detailed statistical formula and structure of BioEquiv are presented with some examples. The comparison between K-$BEtest^{(R)}$ and BioEquiv are given with actual data analysis. BioEquiv is able to present a table of ANOVA test over some complex experimental designs. Moreover K-$BEtest^{(R)}$ and BioEquiv draw the same result when data consists of $2{\times}2$ design.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.13-17
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• 2003

In this paper, the design parameters for the magnetic field source at extremely low frequency are proposed. This facility can be used for in vivo experiments with small animals to investigate biological response to the driving magnetic fields. In case that the exposed animals are motionless, the animals may be affected by the directivity of driving field. To avoid this effect, a 2-axis ELF magnetic field driving apparatus was designed, The optimum location and number of turns of each coil were obtained by numerical analysis. Applying these data to the MATLAB code (for computation), the magnetic field distribution was obtained. The calculation result for a well-designed facility showed that the space in which the amplitude of the magnetic field lies within the 95% of the magnetic field distribution was more than 60% of each axis length.

• 한국기계가공학회지
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• 제14권5호
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• pp.36-41
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• 2015

In this paper, research on the mold design of motor housing produced by the HPDC process was conducted using computer simulations and experiments. Recently, automobile parts have been required to be light and have high strength. The die casting process was used to manufacture automotive motor housings. In the die casting process, the control of casting defects is very important. However, it has usually depended on the experience of the foundry engineer. For the analysis of the manufacturing process of motor housing, the finite element method is applied. Through the simulations using commercial software, the filling pattern and product defects could be confirmed. The analysis results obtained from the filling behavior of the casting process agreed with the experimental results. The computer simulation results of filling behavior were reflected in the optimal mold design of motor housing.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.61-68
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• 2006

In design of the friction clutches of automobiles, knowledge on the thermo-elasticity a priori is very informative in the initial design stage. Especially, the precise prediction technique of maximum temperature and stress should be requested in design of mechanical clutches for their durability and compactness. In this study, an efficient and reliable analysis technique for the design of the mechanical clutches by using computer modeling and numerical method was developed. A commercial software STAR-$CD^{TM}$ was used to find the convective heat-transfer coefficients. MSC/$NASTRAN^{TM}$ software was followed to predict the temperature of clutch with utilization of estimated coefficients. Some experiments were also performed with a dynamometer to verify the procedure and calibrate the thermal load. As a conclusion, a design procedure, including numerical steps and experimental techniques for calibration, was proposed.

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.631-638
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• 1999

Sensitive testing has been widely employed for many years in connection with the development and evaluation explosives detonation devices and propellants. Perhaps its earliest and possibly most important implementation was in biological studies of dosage mortality and response to drugs. Recently sensitivity experiments has been employed in the evaluation of new materials subject to stress in various environments and in delineanation of unstable combustion regions in chemical propulsion systems. This paper discussed a sta-tistical development of sensitivity testing.

• 산업경영시스템학회지
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• 제16권28호
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• pp.103-107
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• 1993

This paper studies computer programming for the analysis of data obtained by experiments using Orthogonal Arrays. The following items are considered in the computer programming : * significant digits in the computation of Sum of Squares, Mean Squares and Variance Ratios * containing the necessary F-distribution values in the program. * matching the rules of KS A 0021 and 3251 in the digit treatments etc. The running results of ANOVA Table and Pooled ANOVA Table of a fictitious example is added with the parts of a program. It should be mentioned that the main purpose of this paper is in the arousing of the discussion about significant digits concept in the computer programming for various kinds of Statistical Methods.

• 한국산업융합학회 논문집
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• 제20권1호
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• pp.74-80
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• 2017

This study aimed to evaluate the validity of an exhausted injector design for filtration system and the performance characteristics thereof. The evaluation was intended through computational fluid dynamics(CFD) analysis based on computer simulation rather than through prototype fabrication and testing. Furthermore, the design of experiment was used to create an experimental design table by which the reaction characteristics of response factors were analyzed for design parameters. All experiments were substituted with computer simulations. Lastly, an optimal design model for the injection tubes was determined based on response surface method algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.872-873
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• 2008

In this paper, a new type of switchgear, electro magnetic force driving actuator (EMFA), is developed and analyzed, applicable to high voltage gas circuit breaker (HGCB). Transient analysis is performed in order to obtain the dynamic characteristics of the EMFA. The distribution of static magnetic flux is obtained using the finite element method (FEM). The governing electric and kinematical equations are solved using the time difference method (TDM). Fabrication and experiments were performed in order to prove the applicability of HGCB for overall class. In comparing the experiment with simulated data, it is confirmed that analysis of the dynamic characteristics of EMFA is appropriate for design.

• 전기학회논문지
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• 제66권1호
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• pp.40-47
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• 2017

In this paper, a small signal model for grid-connected inverter with unipolar pulse width modulation method is presented. Small-signal analysis allows to predict the stability and dynamics of the inverter. To regulate output voltage and to achieve power factor correction, inverter has two control loops. Loop gains are useful to identify the stability for multi-loop controlled system. Based on small-signal model, controllers are designed to improve audio susceptibility and output impedance characteristics. Proposed small-signal model and controllers are verified by PSIM simulation and experiments.