• KEPCO Journal on Electric Power and Energy
• /
• v.7 no.2
• /
• pp.301-307
• /
• 2021

After the spread of the data collection devices such as smart meters, energy data is increasingly collected in a variety of ways, and its importance continues to grow. However, due to technical or practical limitations, errors such as missing or outliers in the data occur during data collection process. Especially in the case of customer-related data, billing problems may occur, so energy companies are conducting various research to process such data. In addition, efforts are being made to create added value from data, which makes it difficult to provide such services unless reliability of data is guaranteed. In order to solve these challenges, this research analyzes prior research related to bad data processing specifically in the energy field, and propose new missing value processing methods to improve the reliability and field utilization of energy data.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.3506-3511
• /
• 2007

The energy harvesting using smart materials has been extensively investigated to supply electric power to wireless sensor systems. In this paper, the energy harvesting using eddy current was studied with the integrated magnetic cantilever beam system. If a large conductive metal plate moves through a magnetic field which intersects perpendicularly to the sheet, the magnetic field will induce small rings of current which will actually create internal magnetic fields opposing the change. This eddy current that was induced in the coiled conductive sheet from the mechanical vibration was converted to chemical energy by charging batteries. The experimental results show that the eddy current generated the electric power up to max 31.2mW. Additionally the vibration reduction of the mechanical cantilever beam was observed by the energy dissipation in the electro-magnetic coupled system. The present result shows that the vibration level of the first natural frequency was reduced up to 7.7dB

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.151.1-151.1
• /
• 2014

Wake field effect on the electron beam from the undulator chamber in PAL-XFEL is analyzed. The wake field takeover some energy from the electron beam which will increase the energy spread of the electron beam. This will cause the degradation of the radiation power in PAL-XFEL. To decrease the effect, the surface of the undulator vacuum chamber should be fabricated with 200 nm surface roughness and 5 nm oxidation layer. In this presentation, the numerical calculation of the wake will be shown. Simulation results of the radiation generation in PAL-XFEL also will be presented.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.6
• /
• pp.113-120
• /
• 2013

Miscanthus is one of the promising energy crops for producing bioethanol or bioenergy in many countries. A field of about 180 ha for miscanthus plantation was started for demonstration near Geum River in 2011. Since the size of the field is much larger than those of traditional cultivation for one single crop in this country, questions were raised if there are any environmental impacts from the energy crop plantation, particularly on water quality. In this study, water quality of runoff water from three different plots was analyzed for assessing the impacts of energy crop production. The results showed that there were no substantial differences among the plots; control, the first, and the second year growth fields. The concentrations of COD, T-N, and T-P were lower than those in runoff water from agricultural crop fields. The second year field showed a slight higher values of COD and T-N concentrations due to the biodegradation of residue of miscanthus which was not cultivated for observation. Commercial planation of miscanthus in a large scale would not result in a water quality problem when avoiding application of fertilizer as practiced in agricultural crop fields.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.3
• /
• pp.165-169
• /
• 2012

Power semiconductor devices are widely used as high voltage applications to inverters and motor drivers, etc. The blocking voltage is one of the most important parameters for power semiconductor devices. And cause of junction curvature effects, the breakdown voltage of the device edge and device unit cells was found to be lower than the 'ideal' breakdown voltage limited by the semi-infinite junction profile. In this paper, Propose the methods for field ring design by DOE (Design of Experimentation). So The field ring can be improve for breakdown voltage and optimization.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.531-532
• /
• 2018

• Journal of Radiation Protection and Research
• /
• v.3 no.1
• /
• pp.6-22
• /
• 1978

High energy electron beams took effect for tumor radio-therapy, however, had a lot of problems in clinical application because of various conversion factors and complication of physical reactions. Therefor, we had experimentally studied the important properties of high energy electron beams from the linear accelerator, LMR-13, installed in Yonsei Cancer Center. The results of experimental studies on the problems in the 8, 10, 12 Mev electron beam therapy were reported as following. 1. On the measurements of the outputs and absorbed doses, the ionization type dosimeters that had calibrated by $^{90}Sr$ standard source were suitable as under 3% errors for high energy electrons to measure, but measuring doses in small field sizes and the regions of rapid fall off dose with ionization chambers were difficult. 2. The electron energy were measured precisely with energy spectrometer consisted of magnet analyzer and tele-control detector and the practical electron energy was calculated under 5% errors by maximum range of high energy electron beam in the water. 3. The correcting factors of perturbated dose distributions owing to radiation field, energy and material of the treatment cone were checked and described systematically and variation of dose distributions due to inhomogeneous tissues and sloping skin surfaces were completely compensated. 4. The electron beams, using the scatterers; ie., gold, tin, copper, lead, aluminium foils, were adequately diffused and minimizing the bremsstrahlung X-ray induced by the electron energy, irradiation field size and material of scatterers, respectively. 5. Inproving of the dose distribution from the methods of pendulum, slit, grid and focusing irradiations, the therapeutic capacity with limited electron energy could be extended.

• The Journal of Korean Society for Radiation Therapy
• /
• v.1 no.1
• /
• pp.63-69
• /
• 1985

High energy electron beams took effect for tumor radio-therapy, however, had a lot of problems in clinical application because of various conversion factors and complication of physical reactions. Therefore, we had experimentally studied the important properties of high energy electron beams from the linear accelerator, LMR-13, installed in Yonsei Cancer Center. The results of experimental studies on the problems in the 8, 10, 12 Mev electron beam therapy were reported as following. 1. On the measurements of the outputs and absorbed does, the ionization type dosimeters that had calibrated by $^{90}Sr$ standard source were suitable as under $3\%$ errors for high energy electrons to measure, but measuring doses in small field sizes and the regions of rapid fall off dose with ionization chambers were difficult. 2. The electron energy were measured precisely with energy spectrometer consisted of magnet analyzer and tele-control detector and the practical electron energy was calculated under $5\%$ errors by maximum range of high energy electron beam in the water. 3. The correcting factors of perturbated dose distributions owing to radiation field, energy and material of the treatment cone were checked and described systematically and variation of dose distributions due to inhomogeneous tissues and sloping skin surfaces were completely compensated. 4. The electron beams, using the scatters; i.e., gold, tin, copper, lead, aluminium foils, were adequately diffused and minimizing the bremsstrahlung X-ray induced by the electron energy, irradiation field size and material of scatterers, respectively. 5. Inproving of the dose distribution from the methods of pendulum, slit, grid and focusing irradiations, the therapeutic capacity with limited electron energy could be extended.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.3
• /
• pp.130-136
• /
• 2003

Crowbar system Vacuum switches, widely used In a pulsed power system, could use the magnetic force to prevent the electrode damage. Vacuum switches using the magnetic forces are classified roughly into RMF(Radial Magnetic Field) and AMF(Axial Magnetic Field) type. The RMF type switches restrain a main electrode from aging due to high temperature and high density arc by rotating the arc which is driven by the Lorenz force. The AMF type switches generate axial magnetic field which decreases the electrode damage by diffusing arc. In this paper, we present the energy loss characteristics of both RMF and AMF type switches which are made of CuCr(75:25 wt%) electrodes. The time-dependent dynamic arc resistance of high-current pulsed discharge in a high vacuum chamber(~10$^{-6}$ Torr). which occurs in RMF and AMF type switches, was obtained by solving the circuit equation using the measured values of the arc voltage and current. In addition, we compared energy loss characteristics of both switches. Based on our results, it was found that the arc voltage and the energy loss of an AMF type switch are lower than a RMF type switch.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.126-127
• /
• 2000

Resonance fluorescence is the manifestation of the interaction between the physical system under consideration and the vacuum-field fluctuation. The fluorescence spectrum provides such physical informations as the energy-level structure of the system, instabilities and relative populations of the energy levels, etc.. One of the typical fluorescence spectra is the Mollow triplet appearing when two-level atoms are driven by a strong coherent field in free space$^{(1)}$ . In the weak field limit, the singlet instead of the triplet is obtained with a reduced linewidth due to the squeezing of one quadrature phase of the induced atomic dipole$^{(2)}$ . On the other hand, when the atoms are put inside a cavity rather than in free space, a doublet spectrum due to the vacuum Rabi-splitting is achieved, showing clearly the coupling of atoms and the cavity in the single-quantum limit$^{(3)}$ . (omitted)