• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.664-667
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• 1997

For higher component density per chip, it is necessary to identify and control the semiconductor manufacturing process more stringently. Recently, neural networks have been identified as one of the most promising techniques for modeling and control of complicated processes such as plasma etching process. Since wafer states after each run using identical recipe may differ from each other, conventional neural network models utilizing input factors only cannot represent the actual state of process and equipment. In this paper, in addition to the input factors of the recipe, real-time tool data are utilized for modeling of 64M DRAM s-poly plasma etching process to reflect the actual state of process and equipment. For real-time tool data, we collect optical emission spectroscopy (OES) data. Through principal component analysis (PCA), we extract principal components from entire OES data. And then these principal components are included to input parameters of neural network model. Finally neural network model is trained using feed forward error back propagation (FFEBP) algorithm. As a results, simulation results exhibit good wafer state prediction capability after plasma etching process.

• International Journal of Automotive Technology
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• 제6권6호
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• pp.615-623
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• 2005

In this research, an effective technique was examined to improve the drift running performance. Concretely, the driver model by which the counter steer was done was assumed to the model by which the vehicle body slip angle (and the vehicle body slip angle velocity) was feed back. Next, the effectiveness of the system which added the assist steer angle corresponding to the steering wheel angle velocity to a front wheel steer angle was clarified as a drift running performance improvement technique of the vehicle. As a result, because the phase advances when the differentiation steer assistance is added, it has been understood to be able to cover the delay of the counter steer when the drift running. Therefore, it has been understood that the drift control does considerably easily. Moreover, it has been understood that the differentiation steer assistance acts effectively at the drift cornering by which the drift angle is maintained in cornering and the severe lane change with a drift at a situation. That is, it was understood to be able to settle to the drift angle of the aim quickly at the time of the drift cornering because the delay of the control steer angle of the counter steer was improved. Moreover, it was understood for the transient overshoot of the vehicle tracks to be able to decrease, and to return to the state of stability quickly at the severe lane change.

• 한국토양동물학회지
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• 제10권1_2호
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• pp.55-64
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• 2005

Predatory nematodes are ubiquitous and feed on soil microorganisms including plant parasitic nematodes. They reduce populations of plant parasitic nematodes in virtually all soils because of their constant association with plant parasitic nematodes in the rhizosphere. Predatory potential of several species of predacious nematodes, belonging to the orders Mononchida, Diplogasterida, Dorylaimida and Aphelenchida, have been studied in detail on plant parasitic nematodes but most of the studies were based on in vitro experiments. A review of progress on the use of predatory nematodes as biological control agents of plant parasitic nematodes reveals that advocacy for predatory nematodes dates back to the early $20^{th}$ century; nevertheless, their potential has begun to be studied in recent years. Information on the efficacy of predatory nematodes under field conditions is lacking; however, some predatory nematodes have given very promising results against plant parasitic nematodes. This article summarizes research progress to date on predatory nematodes and discusses about their possible use in the management of plant parasitic nematodes.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.687-691
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• 2002

To enhance the production of flavonoids [baicalin, wogonin-7-Ο-glucuronic acid (GA)], which are secondary metabolites of Scutellaria baicalensis Georgi(G.) plant cells, a multilayer perceptron control system was applied to regulate the substrate feeding in a fed-batch cultivation. The optimal profile for the substrate feeding rate in a fed-batch culture of S. baicalensis G. was determined by simulating a kinetic model using a genetic algorithm. Process variable profiles were then prepared for the construction of a multilayer perceptron controller that included massive parallelism, trainability, and fault tolerance. An error back-propagation algorithm was applied to train the multiplayer perceptron. The experimental results showed that neurocontrol incorporated with a genetic algorithm improved the flavonoid production compared with a simple fuzzy logic control system. Furthermore, the specific production yield and flavonoid productivity also increased.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.210-213
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• 1999

본 논문에서는 로봇 매니퓰레이터 제어를 위해 새로운 신경회로망을 제안한다. 제안한 신경회로망구조는 은닉층과 출력층의 출력이 피드백 층을 거쳐 다시 은닉층과 출력층으로 피드백되는 구조이다. 피드백 층은 한번의 시간 지연을 갖는다. 제안한 신경회로망의 학습은 일반적인 오차 역전파 알고리즘을 사용한다. 로봇 매니퓰레이터를 대상으로 시뮬레이션과 실험을 통해서 제안한 신경회로망 구조의 유용성을 확인한다.

• Journal of Animal Science and Technology
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• 제44권3호
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• pp.315-326
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• 2002

육성비육우에 대한 황토급여 효과 구명을 위하여 거세한우 송아지 10두(평균체중 : 144.7kg)를 대상으로 황토급여 유무에 따른 2개 처리(T1 : 황토 무급여, T2 : 황토 자유채식) 와 황토급여 수준에 따른 4개 처리(T3 : 황토 무급여, T4 : 황토 2% 첨가, T5 : 황토 5% 첨가, T6 : 황토 자유채식)를 두어 6개월령부터 24개월령까지 540일간 사양시험을 실시한 결과를 요약하면 다음과 같다. 시험 1에서, 일당증체량은 육성기 및 비육후기에는 황토 무급여구가, 비육전기에는 황토 자유채식구가 우수하였으나 전기간 동안에는 황토급여 유무에 따른 차이가 없었고, 1kg 증체당 소요된 농후사료 및 TDN량도 황토급여 유무에 따른 뚜렷한 차이는 없었다. 도체조사 결과, 도체율, 정육율 및 거래정육율은 황토급여 유무에 따른 뚜렷한 차이가 없었으나 육량지수, 전단력 및 관능검사의 각 항목 등은 황토급여시 개선되는 경향이었다. 그 밖에 경제성분석결과 처리구별 소득은 처리구간에 따른 뚜렷한 차이는 없었다. 시험 2에서, 일당증체량은 육성기에는 황토 무급여구가, 비육전기에는 황토 5%구가 그리고 비육후기에는 황토 자유채식구가 우수하였으나 전기간에는 황토급여 수준에 따른 뚜렷한 차이가 없었으나, 1kg 증체당 소요된 농후사료 및 TDN량 관행사육구에 비해 황토 급여구에서 각각 4.5-8.3% 및 1.2-1.6% 적게 소요되었다. 도체조사 결과 등지방두께, 배최장근단면적 및 육량지수는 황토급여 수준에 따른 뚜렷한 차이가 없었지만, 근내지방도는 황토 5% 및 자유채식구에서 높은 것으로 나타났고, 황토를 자유채식시 관행사육에 비해 소득이 15.5% 증가하는 것으로 나타났다. 이상과 같은 결과를 요약해 볼 때 거세한우 비육우에 대해 가공하지 않은 황토 급여시 육량 및 사료이용성에는 뚜렷한 효과가 없는 반면 육질개선에는 다소 영향을 미치는 것으로 나타났다. 따라서 황토급여시에는 비육후기에 자유채식의 형태로 급여하되, 이용성 증대를 위해 미세입자로 하거나 지장수 형태로 급여하는 것이 바람직 할 것으로 판단된다.

• Journal of the Optical Society of Korea
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• 제7권3호
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• pp.193-196
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• 2003

We have developed a laser welding monitoring system to monitor laser welding process conditions such as sample feed rate, laser focal position, and laser power. A 2 ㎾ Nd:YAG CW laser beam has been applied to the welding of a stainless steel plate (SUS306) to investigate the welding monitoring. Theradiation signal from the weld pool was guided back through the focusing optics and the laser delivery fiber, and measured by a photo detector. By changing the focus of the laser beam along the z-direction, the penetration depth of the welding material has been measured. That shows the penetration depth depends on the frequency fluctuations of the plume signals which can be used in welding quality control.

• 대한기계학회논문집
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• 제15권2호
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• pp.436-444
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• 1991

A computational method has been developed to analyze the bone-remodeling induced by external fixator. The method was based on the Finite Element Method (FEM) in combination with numerical formulation of adaptive bone-remodeling theories. As a feed-back control variable, compressive strain and effective stress were used to determine the surface remodeling and internal (density) remodeling respectively. Surface remodeling and internal remodeling were combined at each time step to predict the rel situation. A noticeable shape and density change were detected at the region between two pins and density change was decreased with time increment. At final time step, the shape and density distribution were converged closely to its original intact bone model. Similar change was detected in stress distribution. The altered stress distribution due to the pin and external fixator converged to the intact stress distribution with time.

• 대한기계학회논문집A
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• 제29권5호
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• pp.726-733
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• 2005

A spherical surface referenced Shack-Hartmann method is studied for inspecting machining accuracy of large concave mirror This method is so strong to the vibration environment for using as an on-machine inspection system during polishing process of large optics comparing with the interferometry. The measuring uncertainty of the system is shown as less than p-v 150 m. On-machine measured surface profile data with this method is used for feed back control of the polishing time or depth to improve the surface profile accuracy of large concave mirror. Also, the spherical surface referenced Shack-Hartmann method is useful for measuring aspheric such as parabolic or hyperbolic surface profile, comparing that the interferomehy needs a special null lens, which is to be a reference and difficult to fabricate.

• 한국자동차공학회논문집
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• 제3권1호
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• pp.20-32
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• 1995

Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. In the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert's knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program. two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.