국내 대기 중 독성 휘발성 유기화합물의 오염 특성(Ⅰ) : 측정방법론 평가 Evaluation of Sampling and Analytical methodology

백성옥,김미현,김수현,박상곤 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.2

This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOC_(s)) in Korea. Target compounds included 1, 3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the first part of the study, the performance of sampling and analytical methods was evaluated for the measurement of selected VOC_(s) and carbonyl compounds in the ambient air. VOC_(s) were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis, while carbonyls by the DNPH-silica cartridge sampling with HPLC analysis. The methodology was investigated with a wide range of performance criteria such as repeatability, linearity, lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal standards. In addition, the sampling and analytical methods established in this study were applied to real field samples duplicately collected in various ambient environments. Precisions for the duplicate samples appeared to be comparable with the performance criteria recommended by USEPA TO-17. The overall precision of the sampling and analytical methods was estimated to be within 20-30% for major aromatic VOC_(s) such as BTEX, whereas the precision for major carbonyl compounds such as formaldehyde and acetaldehyde was within 10-20% for field samples. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

誘導電動機의 最適追從制御系 設計方案

白壽鉉 동국대학교 1985 論文集 Vol.24 No.-

This paper proposes the approach of design the optimal tracking control system for induction motors. For this, transforms 3-phase induction motor into 2-phase motor, using d·q axis transformation. After linearize the non-linear state equation of inuction motor which is obtained from 2-phase induction motor model, applied this optimal tracking control system to the linearized system. And these results are compared to the results which are obtained by augmented optimal regulator theory.

커패시터 放電 임펄스 着磁機 및 着磁 요크시스템의 定數算定에 관한 硏究

白壽鉉,金 龍,金必洙,尹秀鳳,朴永浩,尹信容 동국대학교 대학원 1992 大學院硏究論集-東國大學校 大學院 Vol.22 No.-

In a capacitor-discharge impulse magnetizer, a magnet is magnetized by the discharging current of capacitor The actual construction of magnetizing fixtures and discharge matching is expensive and time-consuming. Since the parameters of the impulse magnetizer have been determined and the resistance and inductance of such a magnetizing fixture can be easily computed using FEA, it is possible to predict the performance of such a fixture without actually building it. This paper describes that by mathematically modeling the capacitor-discharge impulse magnetizer fixture the problem can be solved with resonable predictability. The basic equations are presented and used to predict the magnetic-field intensity inside the fixtures. Finite-Element-Analysis is also used as part of the design process

운행차 배출가스 측정방법에 관한 비교 연구

백수현,정일록 동국대학교 산업기술연구원 1998 산업기술논문집 Vol.11 No.-

본 연구는 153대의 운행중인 승용차를 대상으로 부하 및 무부하 운전조건에서 배출가스를 측정하였다. CO와 HC는 두 운전조건에서 유사하였으나 NO_x는 부하 운전조건에서 무부하 운전조건에 비해 87% 높게 나타났다. 이러한 연유로 부하 검사방법이 배출가스 중의 NO_x 측정에 더욱 적정한 것으로 입증되었다. 누적 주행거리와 차량에 따른 배출가스량을 측정한 결과, 부하 검사방법인 ASM 검사에서는 오래된 차량일수록 CO, HC, NO_x가 높게 나타났다. 그러나 무부하 Idle 검사방법에서는 거의 경향성을 보이지 않았다. 따라서 운행 중인 차량의 배출가스 평가에 있어서 부하 검사방법이 더 정확하고 효율적인 수단이었다. Two different exhaust emission testing methods, non-load testing and load testing, were carried out for 153 in-used gasoline vehicles. Although the exhaust emission of HC and CO in both methods was similar, but the emission of NO_x was 87.0 % higher in the load-testing method. The load-testing method, by this reason, turned out to be more appropriate for the measurement of NO_x emission. In addition, the exhaust emission test based on vehicle driving distance and model year was conducted. The result shows that the load ASM testing method, provided high emission of HC, CO and NO_x for old vehicles. Non-load idle test, however, did not found any difference in emission. Therefore, the load-testing method has been suggested appropriate tool evaluating the emissions for in-used vehicles.

변압기의 등가회로를 이용한 LDM의 추력 값 산정

백수현,김일남 동국대학교 산업기술환경대학원 1998 산업기술논총 Vol.4 No.-

The thrust force of moving magnet-type linear direct current motors (MM-LDM) is analyzed in this paper. One method for calculating the thrust force of an MM-LDM is to analyze the energy gradient by the distribution of magnetic flux. However, this method is very difficult to calculate the thrust force. The MM-LDM can be considered a transformer in which the magnet of the mover is assumed to be a one-turn coil carrying a large current. The stored energy in the MM-LDM can be obtained by measuring its self-inductance and mutual-inductance. Calculating the gradient of the stored energy gives rise to the thrust force.

SPICE를 이용한 대용량 다이리스터의 모델링

白壽鉉,金龍,金必洙 동국대학교 대학원 1991 大學院硏究論集-東國大學校 大學院 Vol.21 No.-

In this paper, a unifies thyristor model for power electronic circuit simulations using SPICE is presented. By using this unified thyristor model, we can simulate various characteristic of some circuits more reasonably, accurately. Some simulations using high-power thyristor device(GE C 602LM) has been investigated in order to demonstrate the benefits of the proposed SPICE thyristor model.

VCR用 DD캡스턴 모터의 特性 改善을 위한 設計製作 硏究

白壽鉉,任泰彬 東國大學校 1991 東國論叢 Vol.30 No.-

The DD capstan motor for VCR must be designed fast and adaptively as a small, light and slim type and have the high accuracy of control characteristic because the life cycle of its applying machinery has become shorter and it requires high accuracy of control characteristic. In this study, the design theory of the electric and magnetic parts for DD captan motor for VCR is systematized. Also the design theory and manufacturing method of MR sensor device as a speed detector is presented to enhance the accuracy of speed control, and the flux density of permanent magnet is made uniformly so as to magnetize the super multi-poles and as that result the FG with a high output and high accuracy can be designed and manufactured, which has 0.2% maximum fluctuation of the frequency and -60 dB minimum ratio of S/N. Applying these results to the design of DD capstan motor for VCR, the excellency of this can be proved.

가동 자석형 LDM의 고속 위치제어계 구성에 관한 연구

白壽鉉,金龍,孟仁在 동국대학교 산업기술연구원 1995 산업기술논문집 Vol.6 No.-

본 논문에서는 LDM(Linear DC Motor)의 고속 위치제어를 실현하기 위해, 최단시간 제어이론을 도입하였으며, 복잡한 비선형함수의 계산을 피하고, 제안된 이론을 실현하기 위해 위상평면상에 설정한 포물선 형태의 스위칭함수상에서 뱅뱅제어를 통해 최적절환을 행하였다. 시스템의 모델링 오차와 파라미터의 변동에 의해 슬라이딩 모드가 발생하므로, 슬라이딩 모드가 발생하는 구간을 최소화시키기 위해 포물선형 스위칭함수를 반복실험을 통해 수정하였다. 결과적으로 최단시간 제어이론이 스위칭함수를 수정함으로써 실현되었으며, 스위칭함수를 수정하기 위한 알고리즘을 제안하였다. In this paper, to realize high speed position control of LDM (Linear DC Motor), the minimum time control method is applied. But, In this control method, calculation of non-linear function is required. Therefore, in order to avoid this complex calculation, optimum switching of the Bang-Bang control is done on parabola type switching function established in the plane of phase. But, the sliding mode is occurred due to the modeling error of LDM and the variation of parameters. Thereby, the optimum control is not realized. Therefore, for minimizing sliding section with sliding modes condition considering, the parabola type switching function is modified by repeat of experiment. As the result, minimum time control is realized by amended switching function. So, the algorithm to modify switching function is proposed.

PWM인버터로 驅動되는 誘導電動機의 特性解析을 위한 等價回路

白壽鉉,金龍,金必洙 東國大學校 1990 論文集 Vol.29 No.-

This paper discussed a calculation method of characteristics of induction motor supplied from PWM Voltage Source Inverter. This proposed calculation method based on equivalent circuit of induction motor for fundamental(T-type) and higher harmonics. Using this calculation method, we can analyze more closety to measured value than conventional method through experimental varification.

回轉子 쵸퍼로 制御되는 슬립·링 誘導電動機 閉루우프系의 試作 및 特性解析

白壽鉉 동국대학교 1986 論文集 Vol.25 No.-

슬립·링 誘導電動機 回轉子側에 브리지整流回路, 휠터回路 및 改善된 쵸퍼回路를 연결하여 듀티比에 따른 슬립·링 誘導電動機의 速度制御特性을 向上시키고자 閉루우프 速度制御系를 設計, 試作한 硏究이다. 좀 더 양호한 速度變動率과 速應性을 갖도록 設計한 閉루우프制御系를 동작점 근방에서 小信號動搖모델로 전개하여 動的應答을 구한 이론결과는 실험결과와 잘 부합되었다. 그러므로 본 연구에서 제시한 理論解法은 얻고자 하는 應答特性을 갖도록 閉루우프 制御系를 設計, 解析하는데 유효하게 쓰여질 것으로 기대되며 比例積分器의 성능에 따라서는 速度變動率을 거의 없앨 수 있음을 알았다. This paper is designed and implemented to improve variable speed drive of slip-ring Induction motor(SRIM) with connecting bridge rectifier, developed chopper circuit and filter to the rotor side of SRIM. The closed loop system is designed and implemented to obtain a better speed regulation and fast response. A small signal dynamic model is developed around the given steady-state operating point and its theoretical results are coincided with experimental results. This small signal model for small purturbations of input signals is expected to be useful in designing a closed loop controller with predictable performance. The dynamic performance is very much improved with speed and current feedback and speed regulation can be almost zero with PI controllers.