수피 돈분 부산물 비료의 부숙단계별 분광학적 특성 변화

박창진,김정규,김정제,박용하,신명교,양재의,최문헌 한국환경농학회 1999 한국환경농학회지 Vol.18 No.4

본 연구는 수피 부산물 비료의 돈분 부산물 비료의 부숙단계별 시료의 유기물 분획의 함량 변화, Δlog K값과 RF값 등의 분광학적 특성 변화, 원형여지 chromatograp의 변화를 측정하여, 부숙도의 판정 기준 설정을 위한 기초 자료로 활용하는데 그 목적이 있다. 그 결과를 요약하면 다음과 같다. 수피와 돈분 부산물빌 중 HA-C와 FA-C의 함량은 대체로 부숙이 진행됨에 따라 감소하는 경향이었고, HA-C/FA-C 비는 증가하였다. 수피와 돈분 부산물 비료의 Δlog K값은 부숙이 진행됨에 따라 감소하였으며, RF값은 증가하였다. 생수피의 부식산 형태는 R_p 형태였으나, B형태를 거쳐 120일경과 후 A형태로 변화하여 거의 완숙상태에 도달하였으며, 돈분 부산물 비료의 경우 40일경과 후에도 B형태로 나타나 유기물질의 부숙이 진행중인 것으로 판단되었다. 수피부산물 비료의 원형여지 chromatograph는 120일경과 후에 규칙적인 톱니 모양을 하고 있어 완숙단계에 이른 것으로 판단할 수 있었으나, 돈분 부산물의 경우는 40일이 경과한 후에도 부분적으로 불규칙적인 모양을 하고 있어 부숙이 진행되고 있는 상태인 것으로 판단할 수 있었다. Changes of the spectroscopic characteristics of the organic matter fractions and circular filter paper chromatograph were assessed for the bark and piggery manure composts during the composting. as an approach to base the criteria of the compost maturity evaluation. Contents of humic acid-C (HA-C) and fulvic acid-C (FA-C) in both bark and piggery manure composts were decreased as the composting got closer to maturity, but the ratios of HA-C/FA-C were increased. During the composting. Δlog K values were decreased, but RF values were increased. Humic acid of the mature bark compost after 120 days of composting was A-type, as compared to Rp-type for the raw bark and B-type for the immature compost. However. humic acid of the mature piggery manure composts after 40 days of composting was B-type, indicating the humification of the organic matter fractions continued at this stage. Circular filter paper chromatograph of the mature bark compost exhibited the regular sawteeth pattern at the edge, but that of the mature piggery manure showed an irregular sawteeth pattern. Results demonstrated that spectroscopic characteristics and circular filter paper chromatograph of the organic by-product composts might be employed for the compost stability assessment.

역전파 신경회로망을 이용한 가공조건에 따른 STD-11 절단면의 신뢰성 평가

김선진,성백섭,조규재,김하식,반제삼 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

The purpose of this study was to present the method to choose the optimum machining condition for the wire EDM. This was completed by examining the ever-changing quality of the material and by improving the function of the wire electric discharge machine. Precision metal mold products and the unmanned wire electric discharge machining system were used and then applied in industrial fields. This experiment uses the wire electric discharge machine with brass wire electrode of 0.25mm. To measure the precision of the machining surface, average values are obtained from 3 samples of measures of center-line average roughness by using a third dimension gauge and a stylus surface roughness gauge.

전류제어형 PWM 컨버터를 이용한 On-Line 무정전 전원장치에 관한 연구

김홍성,소정환,김한성,최규하 건국대학교 산업기술연구원 1995 건국기술연구논문지 Vol.20 No.-

Recently, according to the increasing critical loads such as commutation system, life support system in hospital, Computer, the supplying of stable power becomes more and more important. However line fault such as power failure, the variation of voltage or frequency frequently occurs since Utility supplies power to many kinds of loads through the same transmission line. Therefore it is indespensable to stabilize power source like UPS(Uninterruptible Power Supply). UPS system is divided into of-line type and on-line system is studied which can improve various drawbacks of off-line system. And the application of PWM converter to on-line UPS system is proposed and the PWM converter of input characteristics is investigated. As current control method, triangular method is adopted and PI controller is used for DC voltage regulation. And RMS control method is used for PWM inverter. This system is verified by digital simulation using ACSL package.

페트리 네트(Petri Net)를 利用한 FMS 모델 表現 方法

하정진,황규완,김성희 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

Petri Nets is one of the analytical technique for solution of FMS problems. It is a graphical and mathematical modeling and promising tool for describing and studying systems that are characterized as being concurrent, asychronous, dynamic, distributed and parrallel. The objective of this study is to described analytical techniques of FMS and presented for FMS model by using Petri Net.

솔라에어콘 시스템을 위한 4상한 PWM 컨버터의 적용에 관한 연구

김한성,최규하,김홍성 건국대학교 1995 學術誌 Vol.39 No.2

Solar airconditioning system can be a mean to suppress the increase of power peak value in the summer. Generally this system uses the diode rectifier which is simple but the reverse power flow can not be made. It can derate the utilization of solar cell. In addition there have occurred the problem of low power factor and plentiful harmonics at the AC side. Therefore for the purposes of peak power cutting in the summer, bidirectional power flow, unity power factor and low harmonics the 4-quadrant PWM converter should be applied to the solar air conditioner. This paper mainly deals with the characteristic analysis about steady state and transient state of PWM converter for application to solar air conditioning system. As the results of steady state, obtained are the applied characteristics of PWM converter such as low current harmonics, unity power factor. Also through the step response and the power reversal test, the feasibility of the proposed system is verified.

Thyristor를 利用한 交流電流 制御方式에 關한 解析

金漢星,崔圭夏 건국대학교 부설 산업기술연구소 1982 논문집 Vol.7 No.-

To improve the faults of phase control, this paper suggests a new approach to the power control of R-L load with AC supply. AC current control can make the load current continuous during each operation cycle by restricting the magnitude of load current within the given upper and lower reference currents. Therefore the harmonic contents of load current can be greatly reduced and the distortion factor of the output waveform can be better than that of phase control. Digital computer simulation reveals that the AC current control scheme is superior to the phase control scheme in controlling the power flow into the load R-L and experimental results demonstrate the feasibility and verify the operation of the AC current control scheme.

델타변조방식을 이용한 전류형 능동필터의 PWM 신호 발생

김한성,김홍성,최규하,신우석 建國大學校 附設 産業技術硏究所 1993 논문집 Vol.18 No.-

The Delta-Modulation(DM) techniques have been used up to now for both UPS and AC motor drives, which have the advantages of simple circuit, fast response, and insensitivity to load variation and other disturbances. In this paper, the DM techniques are adopted to obtain PWM control signals for active power filters. In the design of delta modluator, the decision of break frequency is the most important, particularly for active power filter application. Both digital simulation and simple experiment are performed to investigate the characteristics of the delta modulator proposed.

CO₂아크용접기를 위한 3상 전압형컨버터의 입력역률개선

최규하,최해룡,김홍성 건국대학교 산업기술연구원 2000 건국기술연구논문지 Vol.25 No.-

Diode rectifier has been widely used as preregulator in CO2 arc welding machine, which has an advantage of low cost in application field. One of the demerits of diode-bridge rectifiers, is the line-current harmonic caused by the nonlinear nature of rectifier operation. As it is linked to power utility, a disorder of other instruments can be burst out, and the reactive power degenerates the total system efficiency The adoption of voltage source PWM converters can be considered and it must catch the compromise of system performance and cost. So, in this paper voltage source converters which have single and six control switch respectively, are analyzed and confirmed through digital simulation and experiments. In addition the improved input characteristics of CO2 arc welding machine known as low power factor system with nonlinear property, are shown and evaluated compared to conventional one.

요로조영상에서 요관폐색 및 음영결손을 보인 환자에서의 요관경검사

염규영,하용원,노안식,손성용,김진겸,설종구 충남대학교 의과대학 지역사회의학연구소 2000 충남의대잡지 Vol.27 No.2

Purpose: To evaluate the clinical value of ureteroscopy for the ureteral filling defect or obstruction on the excretory or retrograde pyelogram(RGP). Materials and Methods: The 72 patients with filling defect or intrinsic obstruction ureteral lesion on the excretory urogram or RGP underwent ureteroscopy to examine and treat the lesions. We used the 9.5Fr. or 11.5Fr. rigid ureteroscope with 5Fr. working channel. Results: The results were as follows; I. Among the 72 patients, 39 were male and 33were female. The mean age of patient was 45.7 years. 2. Ureteroscopy was successfully performed in 70 cases(97%) out of 72. In 2 cases, the advance of ureteroscope was failed. 3. Among 70 successful cases, ureteroscopy revealed 45 radiolucent stones, 9 ureteral stricture, 2 ureteral TCC. I metastatic tumor, 3 blood clot, each case of ureteral polyp, epithelial hyperplasia and Von-Brunn's nest. In 7 cases, no causative lesions were identified. 4. 41 out of 45 radiolucent stones were successfully removed by ureteroscopic procedure and 9 ureteral strictures were dilated. 6 cases of ureteral mass were successfully biopsied for pathological diagnosis. 5. 23 cases of post-operative or fever were treated conservatively and 10 cases of mucosal tearing and 1 case of ureteral perforation were treated with double-J stent indwelling. Conclusions: The ureteroscopy is effective modality to evaluate and treat in the ureteral filling defect or obstruction on the excretory urogram.

능동전력필터를 위한 새로운 전류제어 델타변조방식에 관한 연구

최규하,김한성,강병희 건국대학교 1996 學術誌 Vol.40 No.2

Advances of Power Electronics in industrial domains lead to continuous increase of harmonics on net-works. To solve these problems, Active Power Filtering(A.P.F.) concept has been developed for several years. This paper describes an A.P.F. comprising Current Source Inverter (CSI) by Current-Controlled Delta-Modulation Technique. This Concept is applied to a new current source Sigma-Delta Modulation(SDM) inverter for A.P.F. As associating this concept with current source inverter(CSI) APF, there are several advantages. Most of all, this controller can be easily implemented and has a satisfactory compensating performance. In addition, inverter output fitter, the capacitor and inductance size are considerably reduced. The controller is implemented by analog circuit and one-chip micro-processor(TMS370C756). As the typical load which generates the harmonics, a 3-phase diode rectifier is used, The proposed scheme is investigated by digital simulation(ACSL). Also, the theoretical results is verified by analog & digital experiment.