• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1332-1336
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• 1990

This paper deals with some analytical and experimental aspects to control a multi-magnet suspended vehicle. Because the response of a multi-magnet vehicle shows mutually coupled interaction, an analytical description of the vehicle dynamics is necessary. For numerical computations, a linearized modelling of vehicle dynamics is dicussed and computer simulation is carried out. And for the experiment, a test vehicle suspended by four magnets has been made and investigated by local control of each magnet. Two algorithms by PID and state feedback control law are used and compared with each other. Some kinds of disturbance characteristics and coupling effects of the width change of the test vehicle are experimented.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1337-1342
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• 1990

This paper deals with control system design strategy for electrolmaginetic suspension (E.M.S.) system. For a successful control of E.M.S. system, the nature of E.M.S. system is deeply studied in the view point of non-linear, open-loop unstable, time-varying, non-minimum phase system. To find a special control treatment for E.M.S. system, analyses and simulations for various models are carried out. As one of the successful candidates, adaptive control concept is introduced and sample hardware system using digital signal processor is implemented.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2611-2613
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• 2002

본 논문에서는 전력선 통신 채널의 간접 잡음 측정에 대한 연구를 하였다. 주위 환경에 의한 Noise 및 여러 통신매체에 의한 방해전파에 의해 전력선 통신 채널은 송신 측의 고출력 요구와 가능한 전력선 통신의 대역폭이 감소하는 악화된 통신환경을 보여 준다. 이러한 Noise를 측정하는 방법은 Coupling Capacitor를 이용한 직접 측정 방식과 이동 측정 장치를 이용한 간접 측정 방식이 있다. 전자는 광범위한 측정지역과 측정장비의 설치 등에서의 번잡함으로 효과적인 Noise 측정이 어렵다. 본 논문에서는 두 가지 방식의 Noise 측정 결과의 비교 및 검토를 통해 이동 측정 장치를 이용한 방식의 장점과 보완할 점을 검토였으며, 특히 직접 측정 방식과의 결과 값의 차이를 보상할 수 있는 상관관계 분석의 필요성을 고찰하였다.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.207-210
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• 2004

This experiment was conducted to determine economic application method of Yakto among 6 application method : amount of Yakto application 3 plots(70 l, 25.5 l, 13.3l/kan), and added side dressing(3 l/kan) each plot. The reduced Yakto application(25.5 l/kan) with side dressing(3 l/kan) showed similar root diameter, fresh weight of roots and yield of good seedlings to standard Yakto application(70 l/kan). And also this application method of Yakto gave similar content of Ca and Mg, but the lower content of N, P, K in roots to standard Yakto application(70 l/kan). These suggested that 25.5 l Yakto application added side dressing(3 l/kan) per kan might be economical application method of Yakto.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.234-234
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• 2003

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2575-2580
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• 2005

In this paper, we address two position control scheme; the lead-lag control and the sliding mode control for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived simply. The sliding mode control algorithm is more effective than the lead-lag control algorithm to reduce effects from movements and disturbances of other axis.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.182-183
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• 2004

Atmospheric carbon monoxide (CO) and ozone $(O_3)$ play the important trace gases in tropospheric chemistry, through its concentration in the troposphere directly influences the concentrations of tropospheric hydroxyl (OH). Understanding the impact of CO and $O_3$ on the global tropospheric chemistry requires measurements of the global atmospheric CO and $O_3$ distributions. This study focuses on the identification of CO and O3 released in the East Asia between March 2000 and February 2004. During the period, the MOPITT instrument onboard the Earth Observing System (EOS)-Terra platform collected extensive measurement of CO. So we have used MOPITT data at 700hPa to analyze seasonal distribution of CO concentration. And the O3 measurements for this study were Total Ozone Mapping Spectrometer (TOMS) and Dobson spectrometer provided NASA/GSFC and Yonsei University, Korea. During springtime, the CO and O3 concentrations were increased over East Asia for April, May, and June. CO and O3 transport and chemistry in the springtime in East Asia are studied by use of the HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model.

• Polymer Science and Technology
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• v.17 no.6
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• pp.742-751
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• 2006

• Bulletin of the Korean Space Science Society
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• 2002.10a
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• pp.76-76
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• 2002

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.368-370
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• 1998

In order to determine the optimal radiation dose for the sterilization of biowastes, the bioburden, frequencies and radiosensitivities of bacteria, mold and fungi in rice straw, chaff, corn stover and sawdust was observed before and after ${\gamma}-ray$ irradiation. Radiation sterilization dose of rice straw, chaff, com stover and sawdust was calculated as 17.7, 17.6, 15.6 and 20.0kGy, respectively, from the mutual compensation of screening dose and derived dose on the basis of $10^{-3}$ SAL. This method could be acceptable for the sterilization of various biowastes including food, pharmaceuticals, etc.