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.

해양온도차발전 Closed and Regeneration Cycle의 기본 정특성

차상원(Sang1Won Cha),김유택(You1Taek Kim),이영호(Young1Ho Lee) 한국유체기계학회 2011 유체기계 연구개발 발표회 논문집 Vol.2011 No.11

Ocean Thermal Energy conversion(OTEC) technology is one of OTEC technology refer to a mechanical system that utilizes the natural temperature gradient that exists in the tropical ocean between warm surface water and the deep cold water, to generate electricity and produce other economically valuable by-products. The selection of working fluid and working conditions of the OTEC’s cycle has a great effect on the system operation, and it’s energy efficiency and impact on the environment.Working fluids of the OTEC is Ammonia, R22, R407c, R410a. Ammonia have a large heat capacity. But, ammonia is difficult to treat. R22 has been proposed as the working fluid instead of ammonia due to toxicity problems, it would be prohibited according to the Montreal Protocol. Therefore, more research is needed on developing more suitable working fluid substitutes. It is a R407c, R410a. In this paper, the optimization of and Ocean Thermal Energy Conversion(OTEC) system is carried out by the Powell method (according to the Workin g Cycle and Working Fluids).

관절성형술 및 측두근막 이식술을 이용한 악관절 강직증의 치험례

진택현,오승환,류동목,김여갑,이상철 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.1

This is a case of bony ankylosis of right temporomandibular joint with mild facial asymmetry resulted from trauma, which bring about the right condylar fracture, and corrected by interpositional arthroplasty with temporal fascia flap and coronoidectomy. The postoperative results were functionally and esthetically good, but continued osbervation is necessary to evaluation of abnormal bony growth and reankylosis.

음향방사로 인한 주기구조물에의 모우드 해석

박상기,임경택,이동하,김택현,김종태 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.2

In this study, the mode shape of infinite fluid loaded plate is examined. The stiffeners are assumed to be equally spaced and exert only force on the Plate. The response of a fluid loaded ㄷ-type stiffened plate to a convected harmonic pressure and the far field radiation Produced by a point force excitation have been found by using Fourier transforms, a method which is particularly useful when fluid loading is included. At low and high frequencies the far field Pressure for a point excited stiffened plate is dominated by the fluid properties and the properties of the plate at the point of excitation. Mode in the far field pressure is found at the given direction of scattering frequencies, and in these frequencies the stationary phase wave frequencies are found to coincide with the free wave propagation constants for the stiffened plate. Also, the variation in the modes of the sound pressure level is increased with the increases of the bay space and in the bay area

인지이론을 근거로 한 수학학습 방법 탐색과 지도의 실제

서성보,박성택 부산교육대학교 초등교육연구소 1996 초등교육연구 Vol.9 No.-

The purpose of this to sequentialize Mathematics-learning contents, and to explore teaching-learning model for mathematics, which on the basis of the theory of cognitive development and the period of conservation for children. The results of subjects are as follows: (1) Cognitive development can be achieved by constant space and Mathematics knowledge is obtained by the interaction of experience and reason. (2) The stages of cognitive development for children to teach mathematics systematically and orderly. (3) The learning effect of mathematical concepts occurs when this coincides with the period of conservation formation for children. (4) Mathematics Curriculum of Elementary School in Korea matches with the experimental research about the period of Piaget's conservation formation. (5) Mathematics learning is to be centered on learning by experience such as observation, operation, experiment and actual measurement.

생물학적 폐수처리시 휴지기간이 처리특성에 미치는 영향에 관한 연구

김상수,문병현,서규태,이택수 7개 국립대학교 환경연구 논문집 공동발행 위원회 2004 공업기술연구 Vol.4 No.-

Under recent situation of more stringent effluent regulations, small scale biological process for industrial wastewater treatment has on operational problems, such as highly variable loadings into the system. Especially, the seafood processing industry has difficulties to treat is because of its highly variable organic loading and high saline concentration (>30g/d㎥). High salt concentrations disrupt metabolic functions and cause plasmolysis and/or loss of activity of microbial flora, hence the biological treatment of the saline wastewaters could produce low COD removal efficiency. On the basis of background mentioned above, an appropriate operation of the existing treatment plant is required for stable effluent discharge at even highly influent loading. In this study, effects of long term ( days) idle periods on floc characteristics were investigated in treatment of saline wastewater by SBR. Temporal stop of feeding affects biological activity in the reactors and then floc structures such as size and fractal dimension. After a certain period of reoperation for orgnic activity, the size and fractal dimension of floc start to increase.

스포츠 참여와 청소년 비행에 관한 연구

임상용,윤상택 濟州大學敎 體育科學硏究所 1995 체육과학연구 Vol.1 No.-

The purpose of this study was to present a preliminary data of dynamic processes underlying the relationship between sport participation and delinquent behavior. More specifically, this study attempted to determine the relative contribution of 13 socioeconomic, sport environmental and sociopsychological variables in delinquent behavior among male and female athletes and nonathletes. The subject of this study was 1,292 male/female students form 19 selected middle schools(n=678) and high schools(n=613). Of the 1,292 in total sample, 336 were classified as athletes, and 926 were classified as nonathletes. Self-report questionnaires were administered to the sample. For the purpose of data analysis, correlation analysis, multiple regression analysis and analysis of variance was used. The major findings of the study were as follows. 1. Nonathletes exhibited significantly less delinquent behavior than athletes. 2. Male nonathletes exhibited less deliquency than male athletes while, female athletes did not differ significantly from female nonathletes in delinquent behavior. 3. Nonathletes exhibited significantly less delinquent behavior than athletes in both middle school students and high school students. 4. The 13 variables showed greater relevancc to delinquent behavior among nonathletes than atheletes. 5. The four variables of delinquent associates, delinquent value, self-concept, and boredom accounted for the greatest amount of the explained variance in delinquent behavior among male and female athletes and nonathletes. 6. Of the 13 variables among athletes, seven predictor variables were predictive of delinquent behavior. Delinquent value was the best predictor and followed by self-concept, delinquent associates, saticifaction of sport facilities, boredom, life level and sport value. Among nonathletes five variables were predictive of delinquent behavior. Age was the best predictor and the next predictors followed by delinquent associates, delinquent value, self-concept and frequency of sport participation. 7. Among male athletes, six predictor variables were predictive of delinquent behavior. Self-concept was the best predictor and followed by delinquent value, satisfaction of sport facilities, boredom, delinquent associates and sport value. On the other hand, among male nonathletes, five predictor variables were predictive of delinquent behavior. Age was the best predictor and the next ranking order followed by delinquent associates, delinquent value, self-concept and frequency of sport participation. 8. Among female athletes, three predictor variables were predictive of delinquent behavior. Delinquent associates was the best predictor and followed by age, boredom. On the other hand, among female nonathletes, four predictor variables were predictive of delinquent behavior. Delinquent associates was the best predictor and followed by delinquent value, self-concept and boredom.

응집제의 주입량 및 압력변화에 따른 여과특성

이성호,임택준,조준형 강원대학교 삼림과학연구소 2001 Journal of Forest Science Vol.17 No.-

제지공업은 다른 공업에 비해 용수 소비량이 많고 이에 따라 폐수의 배출량도 많은 용수 다소비 산업이다. 제지폐수의 처리는 물리적, 화학적, 처리로 1차 처리를 하고 생물학적 처리로 2차 처리를 한 후, 필요에 따라 고도처리를 행하여 재이용 하거나 방류하는 시스템으로 구성되어 있다. 물리적 처리 중 응집침전법에 의한 처리방법은 생물학적 처리의 전 단계로서 처리가 불량할 경우 생물학적 처리 시스템의 부하량이 높아져 처리율의 저하를 유발한다. 또한 가장 비용이 적게 드는 처리방법이므로 응집침전에서 많은 오염물을 제거하는 것이 비용 면에서도 유리하다고 할 수 있다. 제지공장의 폐수에는 Fiber, Filler, 그 밖의 유기용매가 포함되어 있으며, 폐수량이 많기 때문에 그 만큼의 설비자본과 운영비가 소요된다. 그러므로 폐수의 양을 줄이고 그 안에 함유된 여러 가지 물질들을 적은 비용으로 효율적으로 제거하는 방법이 필요하게 된다. 본 실험은 제지폐수를 보다 효율적으로 여과하는 방법을 찾고자 함에 있어 가압 여과시험을 채택하여 응집제의 종류 및 첨가량 그리고 압력의 변화를 주면서 여과의 특성 실험을 하였다. 폐수내의 섬유나 Filler 등은 미세하게 분산되어 콜로이드성 물질이 되는데 이것은 여과시에 여재 위에 쌓여 여과 조작을 방해한다. 여기에 응집제를 첨가하게 되면 분산된 콜로이드 입자를 응집제가 표면에 사슬처럼 붙어 안정화시킨다. 즉, 침전성과 여과성이 향상되고 SS가 떨어진다. 본실험에 사용된 응집제는 FeCl3, Alum, CaCl2, Polymer 이며, 네 가지 응집제를 0.01g, 0.03g, 0.05g 씩 첨가(폐수 100mL에 대해)하고 압력을 49, 98, 147, 196 kPa로 변화시키면서 실험을 하였다. 이와 같은 여러 변화의 실험을 통하여 각 단위 시간 별로 여과되는 여액량을 측정하여 여과 속도 및 탁도 등을 측정하였다. Compared to other industries, pulp and paper industry use a lot of water. As a result, a large amount of the waste water is discharged in the pulp and paper industry. This study was investigated to prevent the environmental pollution terribly faced with our society nowadays. In the waste water of pulp and paper there are so many things in the waste water, like fiber, filler, and other organic solvent etc. so we must remove them from our environment. This study was investigated to experiment on test of impressed filtration with the kind and quantity of coagulant and the variance of pressure. In this study, we used feds, alums, CaCl2, polymer as a coagulant and these pressure was 49, 98, 147, 196kpa. According to this study, we measured the speed of filtration and turbidity, measuring filtrated water. According to the values, we know the fact that as the consistency of coagulant and pressure were high, the filtration was good.Key words : Coagulant, wastewater, filtration, turbidity

염분이 함유된 폐수의 생물학적 처리시 염분농도가 오염물질의 제거에 미치는 영향

김상수,문병현,이택순,서규태,공남식 7개 국립대학교 환경연구논문집 공동발행 위원회 2005 공업기술연구 Vol.5 No.-

Effects of salt concentration and C/N ratio on pollutants removal efficiencies were investigated in treatment of seafood wastewater by sequence batch reactor(SBR). The synthetic seafood wastewater containing salinity from 3,000 to 10,000 mg/L NaCI and C/N ratio of 2 and 4 was treated by SBR. Removal efficiencies of COD_(Mn), T-N, and T-P decreased with increasing salt concentration, but eventually reached a pollutants removal a platrau. As systems adapted in salts until salts concentration of 8,000mg/L, the time required to reach the pollutants removal efficiencies at steady state was reduced. However, the removal efficiencies of pollutants sharply decreased and the time require to reach steady state was increased as salt concentration rose to 10,000mg/L, Removal efficiencies of COD_(Mn) were higher for C/N ratio of 4 than for 2. Effects of salt on the nitrogen removal were not faster than the organic removal but the time required to the nitrogen removal at steady state was ncreased. The removal efficiencies of phosphorus also were redueed as salt concentration increased, which inhibited the release of phosphorus than the uptake.