풍력 발전 시스템의 회전익 토오크 모델링

부성환,임종환,허종철,김건훈 제주대학교 산업기술연구소 1999 尖端技術硏究所論文集 Vol.10 No.2

Torque generated by the blade of a wind turbine is a non-linear function of the wind velocity, the angular velocity of the rotor and the pitch angle. Glauert's theory for propellers, though widley used, is not suited to simulate the performance under variable wind speed and pitch angle. Furthermore, the numerical iteration procedure of the theory districts the applicability of a real time control of the wind turbine. We suggest a new method of modeling the torque that can be used in a real time control. Based on Glauert's theory, the power coefficient curve is estimated. In the vicinity of the operating point on the curve, a linearized model is extracted in terms of the wind velocity, the angular velocity and the pitch angle. the usefulness of the model is demonstrated with the results produced by sets of experiments.

Mg_(x)Zn_(1-x)FeAIO₄의 결정학적 구조 및 Mo¨ssbauer 효과

부수영,홍성락,고정대 濟州大學校 基礎科學硏究所 2000 基礎科學硏究 Vol.13 No.1

Mg_(x)Zn_(1-x)FeAlO₄ spinel ferrite에 대하여 X-선 회절과 Mossbauer 스펙트럼을 조사하였다. X-선 회절상으로부터 Mg_(x)Zn_(1-x)FeAlO_(4)는 면심입방구조를 가지는 spinel ferrite임을 확인하였고 Mg 함유량 x가 증가함에 따라 격자상수는 선형적으로 감소하여 8.3496A - 8.4128A의 값을 보이고 있다. Mossbauer 스펙트럼은 모든 시료가 초미세 자기장에 의한 공명흡수선이 나타나고 Mg 함유량 x가 증가됨에 따라 초미세 자기장은 20K와 300K에서 모두 증가하고 있다. I.S.값이 0.2569mm/sec에서 0.3564mm/sec사이에 존재하는 것으로 Fe^(3+)로 이루어져 있으며, Q.S.값은 zero값에 가까운 값이므로 대칭분포 구조를 갖는다.

풍력 발전 시스템의 회전익 토오크 모델링

부성환,임종환,허종철,김건훈 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.2

급성 지주막하 출혈에 동반된 관상동맥 연축에 의한 심근경색증 1예

부귀범,박근호,양종태,이동민,장성종,김건영,장경식 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.1

In many cases, acute cerebrovascular disease is accompanied by abnormal electocardiograms. Also, though rather uncommon, acute myocardial infraction is also seen. The mechanism of its occurance is uncertain but it is thought to be related to coronary artery spasms, an abnormal autonomic nervous system, and a catecholamine increase. A female patient of 34 years of age came to the hospital because of sudden headache accompanied by substernal chest pain. A subarachnoid hemorrhage due to a cerebral aneurysm rupture had occured, and there was ST segment elevation in lead II, III, and aVF of the electrocardiogram. A cardiac enzyme test, an echocardiography, and a coronary angiography were performed, and she was diagnosed to have acute myocardial infarction due to coronary artery spasm. Clipping of the aneurysm was performed. With the use of nitrate and an angiotension converting enzyme inhibitor, the condition of the patient improved.

협동학습에서 팀 구성원의 자기 및 동료평가를 위한 평가문항 개발

부성미,박찬정 한국컴퓨터교육학회 2003 컴퓨터교육학회 논문지 Vol.6 No.4

제7차 교육과정이 시작되면서 수업의 형태가 다양화되어지고 있다. 이 중에 팀별로 문제를 해결하는 협동학습이 학교에서 진행되고 있는데 협동학습 시 평가를 위한 연구는 많이 진행되고 있지않다. 한편, 웹기반교육인 경우 매체의 특성 때문에 협동학습이 더욱 잘 활용될 수 있다. 향 후, 웹기반 협동학습을 위한 선행연구로서 전통적 협동학습에서 결과 중심의 평가방법을 지양하면서 팀별로 문제해결을 위한 과정을 종합적으로 평가하며 팀 구성원을 개별적으로 평가할 수 있는 새로운 학습자 평가문항이 요구된다. 본 논문에서는 ABET EC 2000에서 개발한 프로그램 결과물과 평가에 관한 속성들 중에서 관련되는 속성을 추출하고 Bloom의 인지적 영역을 혼합하여 평가문항을 마련한다. 또한, 본 논문에서는 제안한 평가방법에 의해 반은 점수와 제안한 평가문항으로 설문을 실시한 후의 점수를 이용하여 본 논문의 결과물에 대한 응용 사례를 제시한다. There are various kinds of instructional models in the 7th national curriculum. Among them, cooperative learning is given to students in some schools. In cooperative learning, the items for assessing the team members are required in order to evaluate the individual activities for problem solving, and to know the way of objective thinking each student does. Web-based environment is good for cooperative learning. In this paper, as a previous research work of web-based cooperative learning, we propose new assessment items which are based on the outcome D belongs to the set of 11 student teaming outcomes design attributed framework developed by ABET EC-2000 and the cognitive categories defined by Bloom’s taxonomy. These assessment items consist of self and peer assessment. The self assessment items include the evidence of the students’ thought and their own assessment. On the other hand, the peer assessment can give the students the opportunities to participate in their activities enthusiastically, to offer interactive individual feedbacks, and to develop potential through various experiences.

비동기 카오스 비밀통신의 변복조 기술평가

곽부동,김성곤,최희주,변건식 동아대학교 정보기술연구소 2000 情報通信硏究所論文誌 Vol.8 No.1

During the past five years, there has been tremendous interest worldwide in the possibility of exploiting chaos in wideband communication systems. Many different demodulation techniques have been proposed up to date. They can be divided into two basic categories. In the first approach, like the conventional coherent demodulation techniques, the chaotic signal has to be recovered from the received noisy signal by synchronization. However, the chaotic synchronization techniques published to data are so sensitive to the channel noise and distortion that these techniques can not be used in radio communications. In the second approach, the demodulation is carried out nonsynchronization. This paper surveys the different chaotic communication techniques that can be implemented nonsynchronization and compares the threshold and BER of the different methods. Finally, FM-DCSK is introduced the first step for apply to wideband chaos digital CDMA, where the data is not limited by the inherent nonperiodic property of the chaotic signal.

酸素富化用 高分子 氣體分離膜의 現況과 應用

崔成符 龍仁大學校 1994 용인대학교 논문집 Vol.10 No.-

As the technology for synthesis of polymers has progressed, many new membranes for oxygen enrichment have been developed. The design of specific membranes are based on the 28 to 30% oxygen concentration for combusion and 40% oxygen concentration for medical use. If the conentration of oxygen in the air is increased to 30%, the efficiency of fuel combusion is also increased. On the other hand, air of 40% oxygen concentration has been used for patients with diseases in their respiratory organ. Oxygen enrichment membranes have an oxygen permeability coefficient of more than 9 barriecs and separation factors of more than 2.

디지털 시그널 프로세서를 이용한 스카라 로봇의 적응-신경제어기 설계

한성현,차보남 한국공작기계학회 1997 한국생산제조학회지 Vol.6 No.1

During the past decade, there were many well-established theories for the adaptive control of linear systems, but there exists relatively little general theory for the adaptive control of nonlinear systems. Adaptive control technique is essential for providing a stable and robust performance for application of industrial robot control. Neural network computing methods provide one approach to the development of adaptive and learning behavior in robotic system for manufacturing. Computational neural networks have been demonstrated which exhibit capabilities for supervised learning. matching, and generalization for problems on an experimental scale. supervised learning could improve the efficiency of training an development of robotic systems. In this paper, a new scheme of adaptive-neuro control system to implement real-time control of robot manipulator using digital signal processors is proposed. Digital signal processors, DSPs, are micro-processors that are developed particularly for fast numerical computations involving sums and products of variables. The proposed neuro control algorithm is one of learning a model based error back-propagation scheme using Lyapunov stability analysis method. The proposed adaptive-neuro control scheme is illustrated to be an efficient control scheme for implementation of real-time control for SCARA robot with four-axes by experiment.

청정생산기술의 개발 방향과 정책에 관한 연구

최성부 용인대학교 자연과학연구소 2000 自然科學硏究所論文誌 Vol.5 No.1

The cleaner production technology basically reduces or eliminates pollution in the product process, so increases producing yield, saves energy and resource at the same time. The investment cost is expensive at beginning of time but treatment cost of wastes decreases and manufacture cost of products also decreases. These technology is introduced not to think about environment problem as regard of cost but to reduce environmental damage of the manufacture process or products and increase economic efficiency. The domestic enterprise could get over environmental problem and pursuits economic efficiency through application of cleaner production technology.

상전환법에 의한 비대칭형 폴리이미드막 제조에 관한 연구

최성부 龍仁大學校 1997 용인대학교 논문집 Vol.14 No.-

Polyimide(PI) membranes were prepared form PI solutions by the phase inversion technique. The asymmetric membranes formation mechanism was determined by both the interactions between the PI solution and the coagulant and the kinetic aspects during the phase inversion process. The surface structures of PI Membranes were dense with increasing the concentration of PI solution and the evaporation time of solvent. The aggregation states of PI membranes prepared from the dope solution containing DMF(dimthylformamide) showed more porous than that containing NMP(N-methylpyrrolidone). The gas permeation rates of PI membranes decreased with increasing the evaporation time of solvent.