• Journal of Korea Multimedia Society
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• v.4 no.4
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• pp.363-369
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• 2001

This paper proposes a convex hull algorithm for 2D patterns. The proposed algorithm is divided ito 2steps; candidate convex point extraction and final convex point extraction. First step removes as many points as possible that cannot be convex points using simple operation. Second step computes final convex hull of 2D patterns. This method accelerates execution time, since it consists of simple operations. Experimental results show that the proposed method is faster than other 2 methods in speed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.293-294
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• 2017

본 논문에서는 CNN 기반 서명인식에서 시간정보를 이용하여 위조서명을 보다 정확하게 판별하는 방법을 제안한다. 시간정보를 이용하는 첫 번째 방법은 서명하는 전체 시간을 동일한 개수의 등 간격으로 나누어 각각의 이미지를 얻고 이를 합성하여 이용하는 방법이다. 두 번째 방법은 동일한 개수의 등 간격으로 나누어진 각각의 이미지를 CNN-LSTM 으로 판별하는 방법이다. 동일한 개수의 등 간격으로 나누어진 이미지들에는 서명의 속도에 따른 모양의 차이가 발생하기 때문에 비록 최종 서명의 모양이 원본과 매우 유사하다고 하더라도 속도가 다른 경우 위조임을 판별할 수 있다. 두 명의 서명에 대하여 실험을 한 결과 최종 서명이 매우 유사하더라도 속도가 다른 경우 위조로 판별할 수 있음을 보였다. 다만 이미지 합성 과정에 만들어진 새로운 정보로 인하여 진짜 서명을 가짜로 판별할 수 있는 가능성도 늘어날 수 있음을 확인하였다.

• Journal of Astronomy and Space Sciences
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• v.9 no.1
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• pp.120-125
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• 1992

The normalized line profiles of VV Cep have been calculated by integrating the equation of transfer. The Sobolev theory was adopted and the wind velocity distribution was assumed to be V(r) = V$\infty(1-R_c/r)^{1/2}$. The peaks of the line profiles for the phase 0.06 and 0.80 appear at near half maximum and zero velocity surface of the wind, respectively.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.331-332
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• 2006

교류 전동기는 전류의 측정오차와 데드타임 등의 영향으로 전기각 주파수에 동기된 주기적인 토크 리플이 발생한다. 본 논문에서는 주기적인 토크리플 보상 알고리즘을 제안한다. 보상기는 속도리플 관측기와 토크리플 보상기로 나누어진다. 본 논문에서는 토크리플 보상기의 해석을 통해 정상상태에서 속도 리플이 제거됨을 증명하였고 속도리플 관측기는 속도의 리플을 검출하여 토크리플 보상기를 통해 토크리플 성분이 보상됨을 시뮬레이션과 실험을 통해 검증하였다.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.927-928
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• 2006

본 논문에서는 전동기의 속도제어에 필요한 관성과 마찰계수를 추정하는 알고리즘을 제안한다. 속도관측기에서 발생하는 추정속도와 실제속도로부터 최소자승법을 이용하여 관성과 마찰계수를 동시에 추정한다. 모의실험을 수행하여 추정관성과 추정마찰계수가 제안된 방법에 의하여 각각 실제값에 수렴함을 보인다.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.3
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• pp.113-120
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• 2007

Anaerobic batch tests were performed to evaluate the characteristics of methane production from piggery manure such as the ultimate methane yield (UMY), the kinetic constant and the maximum methane production rate. The kinetic behavior of anaerobic degradation of piggery manure was assumed as a first order reaction. The UMY, the first order kinetic constant and the maximum methane production rate were 0.27~0.44L $CH_4/gVS$, $0.161{\sim}0.280d^{-1}$ and 0.043~0.120L $CH_4/d$, respectively. Reactor of piggery manure as the self-seed source of anaerobic digestion resulted in longer acclimation time than reactors seeded with anaerobic digested sludge (ADS). But there was no little difference in the UMY between the two seed materials. The anaerobic digestion can be effective for the treatment of piggery manure containing high concentration of solids, the two-stage anaerobic digestion is, however, thought to be more effective than the traditional single one.

• KSBB Journal
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• v.8 no.5
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• pp.446-451
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• 1993

In ethanol fermentation, by-products such as glycerol, acetic acid and lactic acid are produced along with ethanol. The effects of culture conditions on cell growth ethanol production and by-products biosynthesis were investigated in ethanol fermentation using S. cerevisiae. With increasing aeration rate or yeast extract concentration, ethanol and by-products biosynthesis decreased while final cell mass increased. With increasing glucose concentration or decreasing temperature, final cell mass, ethanol and by-products concentrations all increased. The optimal pH for the cell growth, ethanol and by-products productions was found to be pH 4.5. By-products biosynthesis was found, in general, to proceed with the ethanol biosynthesis. The results can be applied for the optimization of ethanol fermentation and for the recovery and purification of ethanol from the culture broth.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 1992.11a
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• pp.1.4-1
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• 1992

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.105-113
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• 2002

As the number of pedestrian accident increases, the reconstruction of an accident becomes important to find the source of the fault. Generally, accidents are reconstructed by the intuition of experts or primitive physics. A reconstruction method is proposed using sophisticated optimization technology. At first, a dynamic simulation model is established for the accident environment. Occupant analysis for automobile crashworthiness is employed. The situation before an accident is identified by optimization. The impact velocity and the position of the pedestrian are utilized as design variables. The design variables are found by minimizing the difference between the simulation and the real accident. The optimization process is performed by linking an occupant analysis program MADYMO to an optimization program VisualDOC. Since the involved analysis is dynamics and highly nonlinear, response surface method is selected for the optimization process. Problems are solved for various situations.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.198-203
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• 1984

Ethanol fermentation of chemically gelatinized starch and uncooked raw starch was nested with various starchy materials. Starches were gelatinized by 5.4% NaOH and neutralized by sulfuric acid. The patterns of $CO_2$ evolving and the ethanol yield for the chemically gelatinized starch resemble those obtained with thermally gelatinized starch. The alcoholic fermentation of raw starch was carried out by the simultanous saccharification-fermentation using a commercial glucoamylase and yeast. Ethanol yield from uncooked rice starch fermentation was highly comparable to that from cooked one. $CO_2$ evolving rates of the uncooked starches of corn, barley, tapioca and sweet potato were lower than those of the cooked starches. However, the final ethanol yields were similar or slightly lower, depending on the types of starch.