• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1996.10a
• /
• pp.70-77
• /
• 1996

In this study, sliding response analysis of free standing structure such as multi-purpose nuclear spent fuel storage cask is peformed. The governing factors of sliding response are aspect ratio of structure and ground acceleration. The vertical acceleration component is very important factor in the sliding response of the structure. Based on the mathematical model, computer program is developed using direct forward integration method to predict the sliding response. Using the program, several parametric studies were made for sinusodial ground motion and for El Centre 1940 earthquake and Mexico 1973 earthquake. From the results, it is known that the frequency content and duration of strong motion affect the sliding of the structure.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.1-2
• /
• 2010

This paper describes the design of an energy storage system using supercapacitor. The maximum discharging power and duration of the system are 5 kW and 30 second, respectively. To meet the discharging requirement a supercapacitor module(50.4 V 166 F) is selected, and its model parameters are obtained through experiment. The design and simulation results show the usefulness of the system.

• Korean Journal of Hydrosciences
• /
• v.8
• /
• pp.69-83
• /
• 1997

The Parameters of the storage function model (SFM) are taken as constants, while they have different values during every rainfall period and the duration of the runoff. Therefore, the results of the SFM generally show remarkably large errors. In this study, the modified storage function model (MSFM), in which the time variant parameters are introduced, is proposed to improve the SFM which is a conceptual rainfall-runoff model. The fuzzy reasoning method is applied as a real-time control one of the time variant parameters of the proposed model. The applicability of the MSFM was examined in the Bochung river, at a tributary of the Geum River, Korea. The pattern of the predicted runoff hydrograph and the peak discharge by the MSFM with fuzzy control are very similar to the measured values, compared with the results produced by the SFM.

• Journal of the East Asian Society of Dietary Life
• /
• v.4 no.1
• /
• pp.95-104
• /
• 1994

This study was carried out to investigate the effect of sub-atmosphere on the fermentation and heat treatment after fermentation of Kimchi. When the results from the conditions of atmosphere and under-atmosphere were compared, the growth of lactic acid bacteria was increased but the growth of aerobic bacteria was decreased under 560mmHg and 360mmHg. The number of total microorganism was decreased and simultaneously damaged to the tissue of Kimchi under 0mmHg. Kimchi fermented under 560mmHg and 360mmHg had longer storage duration than that of atmosphere. Among the several conditions, the result of heat treatment under 460-260mmHg was the best. the treatment for 4 minutes at 80$^{\circ}C$, 2 minutes at 100$^{\circ}C$, and 1 minute at 120$^{\circ}C$ was good in tissue states and storage.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.6
• /
• pp.1596-1600
• /
• 2010

Surface functionalization of multi-walled carbon nanotubes (MWNTs) was carried out by means of acid treatment. The presence of oxygen functional groups on the surface of acid-treated MWNTs was confirmed with the aid of Fourier transform infrared spectroscopy and X-ray spectroscopy. In addition, carboxylic groups generally formed on the surface of acid-treated MWNTs, and the dispersion was increased by the duration of the acid treatment. The zeta-potential indicated the surface charge transfer and the dispersion of MWMTs. Morphological characteristics of acid-treated MWNTs were also observed using a transmission electron microscopy, X-ray diffraction, and Raman analysis, which was revealed the significantly unchanged morphologies of MWNTs by acid treatment. The hydrogen adsorption capacity of the MWNTs was evaluated by means of adsorption isotherms at 77 K/1 atm. The hydrogen storage capacity was dependent upon the acid treatment conditions and the formation of oxygen functional groups on the MWNT surfaces. The latter have an important effect on the hydrogen storage capacity.

• Journal of Power Electronics
• /
• v.11 no.6
• /
• pp.897-903
• /
• 2011

Many voltage sag compensators have been introduced, including the traditional dynamic voltage restorer (DVR), which requires an energy storage device but is inadequate for compensating deep and long-duration voltage sags. The AC-AC sag compensators introduced next do not require a storage device and they are capable of compensating voltage sags. This type of compensator needs an AC-AC converter to regulate the output voltage. Presented in this paper is a three-phase PWM-switched autotransformer voltage sag compensator based on an AC-AC converter that uses a proposed detection technique and PWM voltage control as a controller. Its effectiveness and capability in instantly detecting and compensating voltage sags were verified via MATLAB/Simulink simulations and further investigated through a laboratory prototype developed with a TMS320F2812 DSP as the main controller.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.2169-2171
• /
• 2001

The vacuum gauge control system has been designed and implemented using multi-serial communication controllers (MSCC) for the 2.5 Gev storage ring at the Pohang Accelerator Laboratory (PAL). There are 20 Balzers vacuum gauges and 17 Granville-Phillips vacuum gauges at the storage ring. A MSCC have two RS485 (max speed 460.8Kbps) field network port, 8 channel serial communication ports (max speed 460.8Kbps) connected to gauge controller for serial communication control. 12 MSCCs are connected to a personal computer (PC) through the RS485 field network. The PC can automatically control the MSCCs by sending set of commands through the network. The commands specify the duration of the MODBUS protocol. Upon receiving a command from a PC running under Windows2000 through the network, the MSCC communicate through the serial output ports to gauge controller. In this paper, we describe control structure and scheme of the vacuum gauge control system.

• KCID journal
• /
• v.1 no.2
• /
• pp.22-28
• /
• 1994

The calculation method for the Drought index based on the principal hydrological factors, such as precipitation, reservoir storage and river discharge, can estimate the duration and intensity of drought. It is not easy to establish an universal criteria o

• KCID journal
• /
• v.4 no.2
• /
• pp.48-61
• /
• 1997

Drought index calculation method using principal hydrological factors, such as precipitation amount and reservoir storage ratio, can estimate the duration and the intensity of drought. It is not easy to establish an universal criteria of drought, since th

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2003.05a
• /
• pp.70-70
• /
• 2003