• 소성∙가공
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• 제18권7호
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• pp.550-555
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• 2009

In the multi-pass shape drawing process, the pass schedule that includes the determination of reduction ratio and intermediate die shape is very important. This study used the equal reduction, equal load, and electric field analysis method for pass schedule of the multi-pass shape drawing. The reduction ratio was calculated by the equal reduction and equal load method. And the intermediate die shape was determined by the result of the electric field analysis and the calculated reduction ratio. The proposed pass schedule method was applied to a shape drawing for producing cross roller guide. Finally, FE-analysis and shape drawing experiment were performed to verify the effectiveness of the proposed method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.91-92
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• 2009

• 제어로봇시스템학회지
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• 제1권1호
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• pp.50-50
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• 1995

It has been pointed out in the literature that the Routh approximation method for order reduction has limitations in treating transfer functions with the denominator-numerator order difference not equal to one. The purpose of this paper is to present a new algorithm based on the Routh approximation method that can be applied to general rational transfer functions, yielding reduced models with arbitrary order.

• 한국정보처리학회논문지
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• 제1권3호
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• pp.380-390
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• 1994

본 논문에서는 컴퓨터 네트워크의 설계에 유용한 등가 라우팅 알고리즘(Equal- cost Bifurcated Routing Algorithm)을 제안하였다. 이 제안한 알고리즘의 성능은 기존의 몬테카를로 시뮬레이션 및 비정상 큐잉 근사화(Transient queueing approximation)를 이용하여 비교되었으며 그 결과 큐잉 근사화는 몬테카를로 시뮬레이 션에 상당히 근접한 결과를 제공하였다. 또한, 큐잉 근사화는 몬테카를로 시뮬레이션 에 비하여 매우 적은 수행시간을 요구하므로 제안한 등가 라우팅 알고리즘은 대부분 의 경우에 우수한 결과를 제공하였다.

• Design & Manufacturing
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• 제13권2호
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• pp.1-5
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• 2019

In this study, micro cellular injection molding of automobile head lamp housing with uneven thickness structure was performed to obtain improvement on deformation and light-weight of the part. The thickness of the presented model was uniformly modified to control the deformation of the molded part. In order to maximize the lightweight ratio, the model having an average thickness of 2.0 mm were thinly molded to an average thickness of 1.6 mm. GFM(Gas Free Molding) and CBM(Core Back Molding) technology were applied to improve the problems of the conventional foam molding method. Equal Heat & Cool system was also applied by 3D cooling core and individual flow control system. Warpage of the molded parts with even cooling was minimized. To improve the mechanical properties of foamed products, complex resin containing nano-filler was used and variation of mechanical properties was evaluated. It was shown that the weight reduction ratio of products with light-weighted injection molding was 8.9 % and the deformation of the products was improved from the maximum of 3.6 mm to 2.0 mm by applying Equal Heat & Cool mold cooling system. Also the mechanical strength reduction of foamed product was less than 12% at maximum.

• 자원ㆍ환경경제연구
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• 제20권2호
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• pp.167-198
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• 2011

최근 우리나라는 2020년 Business-As-Usual(BAU) 대비 30%를 감축하는 탄소배출 감축안을 목표로 설정하였다. 탄소배출 감축목표 달성의 한 방편으로 탄소배출권 거래제가 논의되고 있는 상황이지만, 탄소배출권 거래제를 실시하기 위해서는 가장 먼저 초기 탄소배출권의 배분문제가 해결되어야 한다. 본 연구에서는 탄소배출권 초기배분방식 결정이 우리 경제에 어떠한 영향을 미칠 수 있는가를 중심으로 살펴보았다. 이를 위해 협조적 게임이론인 bankruptcy problem에서의 배분방법을 적용해 배출권을 각 산업별로 배분하였다. 산업별 이산화탄소 배출량은 에너지 통계와 산업연관표를 결합한 하이브리드 산업연관표를 이용해 추계하였다. 세 가지 분배방법에 따른 경제적 파급효과 분석에는 녹색성장회계(green growth accounting) 방식이 적용되었다. 분석결과, 2005년~2007년 기간 동안 우리나라의 연평균 경제성장률은 약 4.36%로 추계되는데, Proportional rule에 의한 배분에 의하면 4.03%, Constrained Equal Awards rule에 의한 배분에서는 4.23%, 마지막으로 Constrained Equal Losses rule에 의한 배분으로는 3.67%로 추산되었다. 따라서 경제성장률 측면에서 보면 Constrained Equal Awards rule에 의한 초기 탄소배출권 배분이 가장 바람직한 것으로 분석된다. 이처럼 초기 배출권의 산업별 배분방식이 어떻게 결정되느냐에 따라 경제에 미치는 파급효과가 매우 상이하게 나타나기 때문에 탄소배출권 도입 및 시행을 위해서는 산업 수준의 연구결과를 반영해야 하며, 각 산업의 특성을 고려해야 할 것으로 보인다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권3호
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• pp.204-209
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• 2004

A partial matched filter (PMF) for semi-coherent correlation code acquisition of the DSSS-CPFSK signal is proposed. It is a calculation-reduced structure of the hard-limited signal based FIR filter, yet its code acquisition time is equal to that of the hard-limited signal based FIR filter. The PMF eliminates duplicate calculations by utilizing the characteristic that the hard-limited DSSS-CPFSK signal has same value in several consecutive samples. For example, the PMF can achieve about 95% reduction in gate size, as compared to the hard-limited signal based FIR filter, when the modulation index of the DSSS-CPFSK signal is equal to 1.5 and the sample rate is equal to 40 sample/chip.

• 한국지진공학회논문집
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• 제17권3호
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• pp.107-115
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• 2013

The purpose of this study was to investigate the performance of hollow reinforced concrete bridge column sections with reinforcement details for material quantity reduction. The proposed reinforcement details has have economic feasibility and rationality and makes construction periods shorter. A model of column sections with reinforcement details for material quantity reduction was tested under quasistatic monotonic loading. As a result, the proposed reinforcement details for material quantity reduction was were equal to existing reinforcement details in terms of the required performance. In the a subsequent paper, the an experimental and analytical study will be performed for the performance assessment of hollow reinforced concrete bridge column sections with reinforcement details for material quantity reduction will be performed.

• 한국도로학회논문집
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• 제17권5호
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• pp.19-24
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• 2015

PURPOSES : The noise, which is typically generated by fast moving vehicles, can be intercepted by installing a noise barrier with a soundproof panel. However, reflections from the panels cause secondary noise, and hence lower the effectiveness of the panels. In this study, the reduction of reflection noise by considering the shape, especially zigzag one, of the soundproof panel have been evaluated. METHODS : The simulation model used in this study was Nord2000, which simulates real-road situations effectively. Based on the simulation results, the joining angle of $133^{\circ}$ with the pattern width (a) equal to 2 m and the projection height (b) equal to 0.5 m was adapted in the zigzag shape as the best profit designing factors. RESULTS: The measuring results at middle height, 15 m showed reduction at all points except the point with average -1.6 dB. At a greater height of 30 m, 2 points showed reduction. A real-sized facility was constructed to investigate the reflected sound from a zigzag shaped panel up to the height of 5 m. CONCLUSIONS: The reduction effects were detected in all the receive points in the range of 2-6 m distances and 1-5 m heights comparing the plane panel. Compared to plane panel, the noises are reduced at an average of 2.4 dBA.

• Transactions on Control, Automation and Systems Engineering
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• 제1권1호
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• pp.50-53
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• 1999

It has been pointed out in the literature that the Routh approximation method for order reduction has limitations in treating transfer functions with the denominator-numerator order difference not equal to one. The purpose of this paper is to present a new algorithm based on the Routh approximation method that can be applied to general rational transfer functions, yield ing reduced models with arbitrary order.