전류 비유 모델에 의한 초등학생의 전류 개념 변화 분석

유병길,강인석,김병철,남만희,박선희,소하연,윤희정,이영아,이하룡,전병문,정승호 부산교육대학교 과학교육연구소 2000 科學敎育硏究 Vol.25 No.-

There exists a major impediment to learning electricity which may illuminate why direct presentation of scientists' ideas is too aggressive a strategy. This impediment lies in thinking that electricity is used up and in envisaging the light bulb as a consumer. This view is based on a powerful idea which summarises much of our experience; it declares that 'things get used up', 'you cannot get something for nothing', and 'intuitive thinking'. To replace this view with scientific view, we made the analogy model. It is suggested that the analogy model is more effective in teaching electricity circuits than conventional teaching method.

우라닐의 폴라로그래피 촉매파를 이용한 질산염의 정량

吳平濟,朴信子 建國大學校基礎科學硏究所 1987 理學論集 Vol.12 No.-

적하수은전극에서 여러가지 농도의 염산과 질산이온 존재하에 초산우라닐용액의 환원에 의한 폴라로그램을 측정하였다. 염화칼륨 지지용액 중에서 초산우라닐의 전기화학적 환원에 대한 안정한 염산농도는 0.02M∼0.3M범위이다. 염산용액과 염화칼륨 지지용액 중에서 질산염용액은 우라닐이온 또는 수소이온이 환원되는 전위까지의 음전위에서도 아무런 폴라로그래프파가 나타나지 않는다. 0.05M HCl용액, 0.1M KCl지지용액중에서 질산염이 공존하는 초산우라닐용액은 -1.2 Volt(vs. S.C.E.)의 전극전위에서 질산염의 농도와 제 2파의 전류사이에는 좋은 상관관계를 이룬다. ??=15+?? 이러한 상관성을 이용하여 미량의 초산우라닐(millimole order concentration)이 존재하는 용액의 폴라로그램을 사용함으로써 극미량의 질산염 농도를 구할 수 있다. 질산염이 공존하는 초산우라닐용액의 제1파는 질산염 존재에 의해 아무런 영향도 받지 않는다. 초산우라닐-질산이온 용액계의 환원파인 제1파는 가역과정이고, 제2파는 가역과정에서 약간 벗어난다. Polarogram of uranylacetate solution, containing Hydrochloric acid and 0.1 M KCl as a supporting electrolyte, have been studied with and without variation of nitrate ion concentrations. No nitrate solution gives polarographic wave with the 0.05M Hydrochloric acid and 0.1M potassium chloride supporting electrolyte solution. It has been observed that the first wave of the uranylacetate solution is not affected by the presence of nitrate ion. Nitrate ion affect the second wave of the uranyl solutions at the electrode potential -1.2 Volt vs. S.C.E. and it is observed that the effects of nitrate concentration on the second wave current are given to be ??=15+?? With these results, method of quantitative analysis of nitrate concentrations by use of polarograms of millimole concentration of uranylacetate solution has been presented.

국가를 당사자로 하는 중재재판제도 연구

강병근 한림대학교 법학연구소 1999 한림법학 FORUM Vol.8 No.-

Barium-Ferrite 組織構造에 關한 硏究

吳平濟 건국대학교부설 산업기술연구소 1980 논문집 Vol.5 No.-

The optimum conditions of preparing barium ferrite from barium carbonate and iron (Ⅲ) oxide are sought for with electron microscope. The result shows that largest quantity of hexagonal barium ferrite phase was found at the mole ratio 1 to 3 of BaCO₃and Fe₂O₃ and its best condition could be got with the secondary sintering temperature at 1,200℃ and for two hours.

구성주의 관점에서의 과학과 열린교육 : 학습자 중심의 과학교육 The learner-centered science education

유병길 부산교육대학교 초등교육연구소 1997 초등교육연구 Vol.11 No.-

There is certainly something fashionable about constructivism in science education nowadays. It is further true that constructivism is by no means a consistent movement, there are many variants of this view in use. Furthermore, it appears that constructivism, for some science educators, in any case, has become the new ideology of science education that provides a cure for every problem of teaching and learning science. But without any doubt constructivism has become also a most valuable guideline for science education -- for science teaching and learning as well as for research in these fields. This paper attempts to reviewscience open education in constructivist's view.

중재합의의 서면성 : Kahn Lucas 사건을 중심으로

康炳根 한림대학교 법학연구소 2001 한림법학 FORUM Vol.10 No.-

The Kahn Lucas case is one of the few cases which dealt directly with the matter on the interpretation of the provisions of Article 2(2) of the New York Convention on the Recognition and Enforcemtne of Foreign Arbitral Awards of 1958. It is quite well-known that Article 2(2) of the Convention sets down the written requirement of arbitration agreement by providing that an arbitration clause or a separate arbitration agreement should be signed. In the Kahn Lucas case, the US Court of Appeals for the Second Circuit firmly decided that the written requirement should be maintained for the contract containing the arbitration clause in issue. In the case, the existence of the comma in Article 2(2) was found critical. One of the interesting points in the Kahn Lucas case is the way in which the lower court in the United States managed it. In Korea, it would be almost impossible for a court to allow the applicant to refer his case to an arbitration institution while the court postponed making the decision to the effect of rejecting the applicant`s claims. Pursuant to the current provisions of the Korean Arbitration Act of 1999, the courts in Korea may not stay the action before them. The Kahn Lucas case deserves thorough analysis in that it is suggestive of the difference between the practices in the American courts and those in the Korean courts.

다층신경회로망을 이용한 교류서보전동기 속도제어시스템

김평호 서강전문대학 2001 산업과학연구 Vol.3 No.-

The mathematical model of the AC Servo Motor is considered and expressed for the speed estimation of AC Servo Motor. NN is trained to approximate the numerator and denominator functions in the speed expression. By trainning such NN(Neural Networks), the speed can be recovered with a high degree of accuracy. With suitable NN, this method can be implemented in real time. To train the controller, the weights are dynamically adjusted using the back propagation algorithm. Neural networks is used to PID control can control efficiencly speed of AC Servo motor.

Self-activated CdS와 CdS: Mn 형광체의 자외선에 의한 발광

유평렬 順天大學校 1987 論文集 Vol.6 No.1

A study has been made for the photoluminescence of cadmium sulfide phosphors. The samples of SA CdS. CdS: Mn Phosphors are prepared by firing at 850℃ for an hour in nitrogen gas. In the case of SA CdS Phosphors, there are two different origins for the emission. that is, the first is due to deep centers (broad luminescence emission) and the second edge emission. It is also shown that the peaks at 565 nm may be attributable to the transition of Mn atoms from the first excited state ⁴T₁(⁴G) to the ground state ??A₁(??S) due to energy transfer in CdS:Mn Phosphors. The separation in energy level between ⁴T₁for Mn₂+ in zine sulfide crystal is about 9,313 cm-¹ at 19K and 250K.

남북상사중재위원회 구성·운영 활성화 방안

강병근 韓國仲裁學會 2004 중재연구 Vol.14 No.1

North Korea and South Korea agreed to refer their investment disputes to arbitration by adopting 'Agreed Minutes on Procedure of Settlement of Commercial Disputes' on 16th December 2000. According to the Agreed Minutes, the two Koreas were to establish an arbitration commission within 6 months after the Agreed Minutes had been signed. In 2002, North Korea enacted laws to draw interest of foreign tourists to Mountain Kumgang and to boost investment into the region of Kaesung as it provided in those laws that commercial disputes should be settled by arbitration or judicial procedures. In October 2003, the two Koreas succeeded in adopting another Agreed Minutes as to the establishment and functioning of North-South Arbitration Commission. The fact that the two Koreas have agreed to establish an arbitration commission is meaningful since they are leading their lives quite differently in political, social, and economic sense for more than a half century. Although there still remain doubts as to the North Korean policy on nuclear matters, an arbitration commission could be a cornerstone for the set-up of the dispute settlement system between the two Koreas and a great help for investors from South Korea to pursue their possible legal claims as North Korea is eager to invite South Korean businessmen and other foreign investors to invest in its special economic areas. According to the Agreed Minutes of 2003, the two Koreas are going to adopt procedural rules for the arbitration commission. It will be a great challenge for them to agree on specific issues as to the operation of the arbitration commission. They have to set up a roster of arbitrators respectively and may have to enact or revise their own arbitration laws and rules reflecting the Agreed Minutes of 2000 and 2003. It is quite welcome that the two Koreas have agreed to set up an arbitration commission rather than resort to political or diplomatic means to settle their disputes. The success of the arbitration system between the two Koreas will make sure the safety of investment environment in the northen part of the Korean Peninsula and will bring the peace to the Korean peninsula earlier than expected.

시정수제어에 의한 교류서보모터의 속도제어특성

김평호 서강정보대학 1998 論文集 Vol.17 No.-

This paper describes the controller for the improving speed control the AC servo motor. The microprocessor provides an output to the difference in command. The servo system improves the characteristics of speed control. When the motor is running at the same speed as set by the reference signal, the speed encoder also provides a signal of the same frequency. Thus, the microprocessor controlled digital techniques enable to realize the flexible performance and control which was possible with time constant. The optimal speed of machining center is 75msec in 30000mm/min and actually, 75msec is using om machining center. Finally experimental results prove excellent performance of this control system. This can reduced error whth more exact measure of actual speed. The system can be adaptable to CNC machine.