機械加工品의 最適加工速度에 關한 硏究

成煥泰,吳澤烈,吳煥燮 慶熙大學校 1980 論文集 Vol.10 No.-

In this study, the optimum mathematical models were made in order to derive Optimum Machining speed which is due to be established in the production of each manufactures as an important parameter based upon the cutting speed, in case of making manufactures of multi-kinds into unit-production processing. The economical optimum cutting speed has been set up by using the above phenomenon as a proper system, and the results from the comparative analysis between the above model & the actual cutting work data, are summarized as follows. (1) The mathematical models for the optimum machining speed are derived into the expressions (23), (24), (25), (26), (27), (28), (29). (2) The basic expressions of the optimum machining speed are derived into (32), (34), (36), (37), (39), (40), (41), (44), for the purpose of each estimation of the maximum efficiency standard, the minimum cost standard and the maximum profits rate standard. (3) The example of setting up the optimum cutting speed of multi-kinds manufacturing production was formulated, and the experimental theoretical values were known to be in the same range as a result of the comparative study between the cutting speed obtained by the cutting test & the optimum cutting speed calculated by the theoretical expressions.

태양광 발전시스템을 위한 계통 연계형 PWM 인버터의 변조지연 보상

성낙규,한경희,강승욱,이승환,유택빈 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-

Since the residential load is an AC load, while the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell and must provide the sinusoidal wave current and voltage, at unity power factor in the case of driving to interact with utility line. PWM modulator must do stable modulation even though it contains the disturbance like a distortion and noise, and it needs compensation method, because there is a timing interval between sampling points and carrier waves, while the synchronous signal is controlled by the micro processor. In this paper, we maximaze output of solar cells which is propotional to variation of insolation, using single phase PWM voltage source inverter, and we can drive in high power factor with utility line by control and compensation method which is concerned with synchronous signal distortion and modulation delay, using low pass filter and phase shifter.

Skemp 理論에 따른 數學學習 效果 分析 : Learning according to Skemp's Theory

朴成澤 부산교육대학교 과학교육연구소 1996 科學敎育硏究 Vol.21 No.-

This study is to adjust the Theory of R. Skemp in the Mathematics Education, apply it to Mathematics Learning and to analyse its effectiveness. The results of the study are summarized as follows. (1) In order to solve the problem in the mathematics education, people must recognize the importance and necessities of mathematics education. (2) Relational understanding is effective form in the mathematics learning, but sometimes instrumental understanding is needed. (3) Mathematics learning requires intelligent learning for the most part, but habit learning should be used on occasion. (4) We cannot understand the higher-order concepts of mathematics by only its definitions. The only way of understanding such concepts is to have experience through suitable examples. (5) Visual symbols and verbal symbols are relatively contrasting, but mutually supplementary. (6) Schematic learning is much more effective than rote learning in the mathematics learning. (7) In order to understand abstract and logical knowledge of mathematics, we need activities based on experiences. (8) Cooperative learning by communications is effective in the teaching-learning of mathematics. (9) A teacher should use a suitable combination of both authority of knowledge and authority of position for classroom management. (10) One should provide to be emotionally pleasurable atmosphere in order to learn mathematics with interest and confidence.

SIIM 퍼지 PI 제어기를 이용한 PWM제어 방식 DC-DC Buck Converter에 관한 연구

이상태,채창현,이상재,고택범 금오공과대학교 산업기술개발연구원 2000 産業技術開發硏究 Vol.16 No.-

The dynamics of DC-DC converters are nonlinear and have problems associated with parasitic resistances, stray capacitances and leakage inductances of the components. PLL(Phase Lead / Lag) compensation is predominantly used in compensator design. But it is hard to tune the parameter of compensator and do not show the good performance in transient period. A new controller for DC-DC converters based on fuzzy logic is proposed. Being free of complex equations and heavy computation, fuzzy control therefore is suitable for the design of optimal compensation for DC-DC converters. This paper presents the derivation of fuzzy PI controller for the basic converter circuits and simulations of the close-loop converters in cases of start-up transient or load variation. Simulation results show that the proposed SIIM fuzzy PI controller make more stable output characteristics and better dynamic performances than conventional methods. This paper describes the fuzzy PI controller using simplified indirect inference method. First, the fuzzy PI controller is derived from the conventional continuous time linear PI controller. Then the fuzzification, control-rule base, and defuzzification using SIIM in the design of the fuzzy controller are discussed in detail.

폐타이어칩 보강 복합재의 제조와 결합재가 복합재의 기계적 물성에 미치는 영향

황택성,박진원 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

For the superior properties of mechanical and thermal aging, this investigation was carried out to develop the recycled of waste tire using various binders (Olefin, SBR Rubber, Polyurethane) for the reuse of the waste tire. In the experimental results show that the mechanical and the thermal aging properties of the composites decreased steadily with increasing content of the waste rubber. We obtained the excellent mechanical and thermal properties when the SBR which is a rubber adhesive was used. Because that total pore area was largen, interfacial adhesive force was weaken. And as the binder was dispersed in waste rubber, the mechanical and thermal aging properties were superior. This result was observed the same phenomena with morphologically.

인슐린 주사제의 고충실 액체색층기 분석

우정택,팽정렬,김성운,양인명,김진우,김영설,김광원,최영길 최신의학사 1993 最新醫學 Vol.36 No.8

數學科 敎授-學習方法의 改善

朴成澤 부산교육대학교 과학교육연구소 1993 科學敎育硏究 Vol.18 No.-

The purpose of this reserch is to find improvement on proper teaching-learning method based on mathematics learning theory and experience. We suggest improvement on effective teaching-learning method in following viewpoints. 1. Learning based on learning hierarchy. 2. Learning based on Cognitive process. 3. Learning that considers individual difference. 4. Learning centers on inductive thinking. 5. Learning based on examples. 6. Learning based on developing and applying algorithm. 7. Learning based on learning process rather than learning product. 8. Experimental learning of Operation, observation, experiment and actual measurement 9. Learning based on mutal cooperation in small groups. 10. Learning that motivates interest and concern.

한·일간의 수학과 교육과정 비교 연구

박성택 부산교육대학교 과학교육연구소 1999 科學敎育硏究 Vol.24 No.-

This research analyses and compares newly revised curriculum of elementary mathematics by both Korea and Japan. It discusses changes of mathematical curriculum between Korea and Japan, and also analyses and compares teaching-learning process and evaluation. From analysing and comparing mathematical curriculum between Korea and Japan, we couldn't find any fundamental differences, but emphasis in parts of the curriculum were a little different.

벌크 GaAs 반도체의 광 스위칭 특성

고성택,강민제,조경호 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.2

A model for a gallium arsenide(GaAs:Si:Cu) photoconductive switch has been developed and solved to determine the performance of the device in bistable switch applications. Simulation studies are performed on a GaAs switch system composed of different density of deep levels to investigate the influence of deep traps in a photoconductive switch system. The computer results show that the initial electron occupation at the deep accepters controls the on-state conductivity of the switch. The required photon flux to turn off the switch is obtained from the computer simulation.

Piaget의 理論에 根據를 둔 數學學習敎材의 保存性에 關한 硏究

朴成澤 부산교육대학교 과학교육연구소 1988 科學敎育硏究 Vol.13 No.-

The purpose of this paper is to analyze mathematical contens of piaget's theory of intellectual development and to explore the conservation of mathematics-learning subject-matter on the above fact analyzed. The results of this study are following: 1) The development of cognition has a specific order and the acquisition of knowledge is formed with the interaction of experience and reason. 2) Arithmetic subject-matter contents are selected and the sequence of them were organized on the basis of the developmental level of quantitative concept conservation shown by piaget. 3) For elementary children discovery learning by the inductuon through the operative teaching-learning principle is efficient.