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 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.

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.

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

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.

비례와 퍼지 제어기를 결합한 Hybrid제어기의 특성에 관한 연구

이상부 제주한라대학 2000 論文集 Vol.24 No.-

This paper investigates the characteristics of the Fuzzy controller and the proportional controller, and also examines and presents the complemently points of each controller. The proportional controller's desirable control is more precise than the Fuzzy controller's, and its response speed is also faster, but its initial value overshoot response is extremely unstable compared to the proportional, the Fuzzy controller's response speed is slow, its command's precise convergent is also not that good but its initial value response characteristic is superior. This paper investigates the characteristic of these controllers through simulation and presents each controller's complemently points.

불소가 함유된 폴리퓨마레이트막의 물성에 관한 연구

崔成符 龍仁大學校 1992 용인대학교 논문집 Vol.8 No.-

The thermal behavior and aggregation characteristic of the novel poly(fumarate) membranes with fluorine have been studied by differential scanning calorimetric analysis, X -ray diffraction and dielectric relaxation.The thermal molcular motion and aggregation structure depend on the bulkiness of ester substituents.The thermal decomposition of these poymers was observed at above 510K.The intermolecular distance of rigid rod-like structure increased with the number of fluorocarbons in the bulky ester group.The dielectric relaxtion of fluorocarbon group and ester group in the side chains occured at 140K and 380K respectively.

퍼지 제어기 구현을 통한 gain 분석에 관한 연구

이상부 제주한라대학 2002 論文集 Vol.26 No.-

At the on-line control method, fuzzy controller is stronger to the disturbance than the classical controller and its overshoot of the initialized value is excellent. The fuzzy controller can do a proper control, though it doesn't know the mathematical model of the system or the parameter value. The fuzzy controller has good performance than the classical controller. Since the once determined control rule is fixed, it can't adjust to the environmentd changes of the control system, the controller output value has a minute error and it can't converge correctly to the desired value. This paper realizes the fuzzy controller by fuzzy implicatilon and inference. This paper analyzes the overshoot, convergence speed, rising time, error of steady state by gain influence.

진화프로그래밍을 이용한 적응 제어기 설계

이상부 제주한라대학 1999 論文集 Vol.23 No.-

The disturbance of the FLC(Fuzzy Logic Controller) is superior to a classical controller and its overshoot of the initialized value is excellent. The fuzzy controller can do a proper control, though it doesn't know the mathematical model of the system or the parameter value. But it has a limit to make the control rule of the fuzzy controller through an expert's experience. Since the once determined control rule is fixed, it can't adjust to the environment changes of the control system, the controller output value has a minute error and it can't converge correctly to the desired value. There are many methods to eliminate the minute error, but this paper suggests the EP-FNNIC(Fuzzy Neural Network Intelligence Controller) which combines FLC with NN(Neural Network) and EP(Evolution Programming). The output charactereistics of EP-FNNIC will be compared and analyzed with FLC. It will be showed that this EP-FNNIC converge correctly to the desirable value without any error. The properties of these two kinds of controllers such as the convergence speed, overshoot, rising time and error of steady state also will be compared.

사망진단서(사체검안서) 상의 선행사인으로부터 사망통계의 원사인이 선정되는 비율 : 3개 대학병원에서 교부된 사망진단서를 중심으로

박우성,박석건,정철원,김우철,탁우택,김부연,서순원,김광환,서진숙,부유경 한국의료QA학회 2004 한국의료질향상학회지 Vol.11 No.1

Background : To exatnine the problems intolved in writing practice of death certificates, we cotnpated the determination of underlying cause of death for wital statistics using recorded underlying cause of death in issued death statistics. Methods : We collected 688 rnortality certificates issue in year of 2,000 from 3 university hospitals. And we also collected vital statistics from ministry of statistics. The causes of death were coded by experienced medical record wpecialists. And causes of death determined at ministry of statistics for national vita statistics were mapped to causes of death recorded at each death certificates. The rate that underlying causes of death for vital statistics were derived from underlying causes of death recorded at issued death certificaties sere analysed. Results : 64.5% of underlying cause of death for could be derived from underlying cause of death recorded at issued death certificates, 8.6% derived from intermediate cause of death, and 3.9% derived from direct cause of death. In 23% of cases, underlying cause of death could not be derived using issued death certificates. The rate that underlying cause of death for vital statistics could be derived from underlying cause of death recorded at death certificates was different between 3 university hospitals. Ane the rate was also different between death certificates and postmortem certificates. We classified the causes of death using 21 major categories. The rate was different between diseases or conditions tha caused death too. Conclusion : When we examined the correctness of death certificate writing practice using abpve methods, cortectness of writing could not be told as satisfactory. There was difference in correctness of writing between hospotals, between death certificates and postmortem certificates, and between diseases and conditions that caused death. With this results, we suggested some strategy to improve the correctness of death certificate writing practice.