• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.749-753
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• 2007

In this paper, a generalized version of the Motion Silhouette Image(MSI) called the Generic Motion Silhouette Image (GMSI) is proposed for gait recognition. The GMSI is a gray-level image and involves the spatiotemporal information of individual motion. The GMSI not only generalizes the MSI but also reflects a flexible feature of a gait sequence. Along with the GMSI, we use the Principal Component Analysis(PCA) to reduce the dimensionality of the GMSI and the Nearest Neighbor(NN) for classification. We apply the proposed feature to NLPR database and compare it with the conventional MSI. Experimental results show the effectiveness of the GMSI.

• Journal of Periodontal and Implant Science
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• 제34권4호
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• pp.781-790
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• 2004

골아세포의 생물학적 기능을 증진시키기 위해 키토산의 표면개질에 대하여 연구하였다. 생체적합성 천연고분자인 키토산은 1차 아미노기를 소유하고 있으므로 적정한 공유결합제를 사용하여 세포성장인자와 같은 생리활성을 지닌 단백질을 키토산의 표면에 고정시킬 수 있다. 본 연구에서는 키토산을 필름형태로 제조하여 세포성장인자 중 형질전환성장인자를 고정하고 골아세포의 부착, 성장 및 분화를 증가시키고자 하였다. 형태전환성장인자의 고정화 효율은 단순한 흡착방법에 비해 높았으며, 표면에 형성된 공유결합은 매우 안정하였다. 골아세포를 배양하여 초기세포부착능에 대한 영향을 연구한 결과, 배양 후 4시간, 1일째, 형질전환성장인자를 고정한 키토산 표면에서 고정하지 않은 키토산의 표면에 비해 더 많은 수의 골아세포가 부착되었고, 더 많이 신장된 부착형태를 보였다. 세포활성정도와 배양 후 4주일째의 칼슘축적량을 측정한 결과, 형질전환성장인자를 고정한 키토산 표면에서 고정하지 않은 키토산의 표면에 비해 더 높았다. 위의 결과는 키토산 표면에 형태전환성장인자의 고정이 성공적으로 이루어졌으며, 또한 실제로 활성이 있는 것이 증명되었다. 위의 연구 결과에서 형질전환성장인자로 고정된 키토산은 골아세포의 초기 부착 및 분화를 촉진시켰음을 알 수 있었던 바 성장인자의 표면고정은 임플란트 및 조직공학용 지지체에도 적용하여 생체적합성과 세포기능을 증진시키는데 이용할 수 있음을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.543-549
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• 2004

Chitosan has been widely researched as bone substitution materials and membranes in orthopedic/periodontal applications. Chitosan nanofiber membrane was fabricated by chitosan nanofiber using electrospinning technique. The structure of the membrane is nonwoven, three-dimensional, porous, and nanoscale fiber-based matrix. The aim of this study was to evaluate the biocompatibility of chitosan nanofiber membrane and to evaluate its capacity of bone regeneration in rabbit calvarial defect. Ten mm diameter round cranial defects were made and covered by 2 kinds of membranes (Gore-Tex membrane, chitosan nanofiber membrane) in rabbits. Animals were sacrificed at 4 weeks after surgery. Decalcified specimens were prepared and observed by microscope. Chitosan nanofiber membrane maintained its shape and space at 4 weeks. No inflammatory cells were seen on the surface of the membrane. In calvarial defects, new bone bridges were formed at all defect areas and fused to original old bone. No distortion and resorption was observed in the grafted chitosan nanofiber membrane. However bone bridge formation and new bone formation at the center of the defect could not be seen in Gore-Tex membranes. It is concluded that the novel membrane made of chitosan nanofiber by electrospinning technique may be used as a possible tool for guided bone regeneration.

• Animal Systematics, Evolution and Diversity
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• 제18권1호
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• pp.85-89
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• 2002

깡충좀벌과의 무늬날개깡충좀벌속(Epitetracnemus)을 우리나라에서 처음으로 보고하며, 또한 이 속에 속하는 1신종, E. kosef sp. nov.를 기재·보고한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1141-1144
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• 1993

For the design of multivariable fuzzy control systems the decomposition of control rules is preferable since it alleviates the complexity of the problem. In some systems, however, inference error of the Gupta's decomposition method is inevitable because of its approximate nature. In this paper, we propose a new multivariable fuzzy controller with a coordinator which can reduce the inference error of the decomposition method by using an index of applicability.

• 자원환경지질
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• 제37권3호
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• pp.365-373
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• 2004

본 연구에서는 신진 고급연구인력의 취업 및 활용 실태를 파악하기 위해 과학재단 인턴연구원 수혜자를 중심으로 지질학을 포함한 지구과학분야의 우리나라 석${\cdot}박사 학위자의 진로추적조사를 수행하였다. 지구환경과학분야의 석${\cdot}박사 학위자로서 과학재단 인턴연구원 수혜자의 미취업율은 32.0%로 조사되었으며, 대학원 진학을 제외한 대학 연구소 산업체로의 정규직 및 임시직 등의 취업은 37.2%에 지나지 않는 것으로 분석되었다. 미국은 국가 인구국 주관으로 미국내 2001년도 박사학위자 진로추적조사를 실시하였으며, 그 결과에 따르면 지구과학 분야 박사학위자 대부분은 취업상태에 있으며, 단지 1.3%만이 미취업상태에서 취업을 희망하고 있는 것으로 분석되었다. 향후 우리나라도 과학재단 또는 관련 학회가 상세한 석${\cdot}박사 학위자 진로조사를 수행하여 지구과학을 비롯한 이공계 신규 석박사 학위자 취업실태를 좀더 자세하게 파악하여야 할 것이며, 이 조사결과는 관계 당국의 지구과학분야의 석 박사 학위자를 위한 고용기회 동향의 파악 및 예측에 활용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.127-131
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• 1993

A new learning method of both NNI and NNC by which the NNI identifies precisely the dynamic characteristics of the plant is proposed. For control of ihe nonlinear plant we use two neural networks, one -for identification and the other for control. We define a closed loop en-or which depends on identification and control error. In the proposed learning method, the closed loop en-or is utilized to train the NNI and the NNC. Computer simulation results reveal that the NNC based on proposed method is insensitive to variations of the plant parameters.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.449-454
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• 1994

This paper describes new PID control methods based on the fuzzy logic. PID gains are retuned after evaluating control performances of transient responses in terms of performance features. The retuning procedure is based on fuzzy rules and reasoning accumulated from the knowledge of experts on PID gain scheduling. For the case that the retuned PID gains result in worse CLDR (characteristics of load disturbance rejection) than the initial gains, an on-line tuning scheme of the set-point weighting parameter is, proposed. This is based on the fact that the set-point weighting method efficiently reduce either overshoot or undershoot without any degradation of CLDR. The set-point weighting parameter is adjusted at each sampling instant by the fuzzy rules and reasoning. As a result, better control performances were achived in comparison with die controllers tuned by the Z-N (Ziegler-Nichols) parameter tuning formula or by the fixed set-point weighting parameter.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.229-234
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• 1992

This paper presents a compensator design method for multivariable feedback control systems with saturating actuators based on the concept of the equilibrium point. Am explicit expression for the compensation matrix of the general anti-reset windup(ARW) scheme is derived by minimizing the distances between the equilibrium points. The resulting dynamics of the compensated controller exhibits the reduced model form of the unsaturated system which can be obtained by the singular perturbational method. The proposed method is applicable to any open-loop stable plants with saturating actuators whose controllers are determined by some design technique. An example is given to show the effectiveness of the proposed method.

• 자원환경지질
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• 제40권6호
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• pp.815-825
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• 2007

This study analyzed trends in geoscientific research funding provided by the Korea Science and Engineering Foundation (KOSEF) and examined strategies to promote geoscientific research. The strengths of geoscientific research in South Korea include the excellent academic quality of researchers, established research infrastructure, and inter-disciplinary research. Weaknesses include insufficient leadership in related societies and institutes, insufficient research productivity, and the exclusion of the field from nationally supported large-scale research projects. Opportunities for expanded research include environmental issues, the sustainable use of natural resources, the promotion of international research cooperation, and the initiation of national efforts to find solutions for regional problems. However, growth in the geosciences is threatened by prioritized investment in fields such as biotechnology, nanoscience, and information technology, a dismissive attitude toward the growth of basic sciences, and an increased demand for projects with visible economic and societal impacts. In terms of funding, group-based programs receive more support than individual-based programs. Between 1978 and 2006, KOSEF invested 1,744 billion won ($1.873 billion US) in a total of 46,748 basic research projects. Of this amount, 62.1 billion won ($66.7 million US) was allocated to 1,901 projects in the geosciences, which was roughly 2.6-10.6% of the money available in a given year. These funds were used to support research and development, the development and maintenance of necessary infrastructure, and the education and training of geoscientists.