• Journal of the Korean Solar Energy Society
• /
• v.28 no.3
• /
• pp.45-52
• /
• 2008

In order to clarify characteristics of variation in wind energy over a long-term period, an investigation was carried out at Seoguang site on Jeju island. The wind data for 10 years from Automatic Weather System (AWS) were analyzed for each year. The variation in the annual energy production (AEP) for the 2 MW wind turbine was estimated through statistical work. The result shows that the range of the yearly average wind speed at 15 m above ground level for 10 years was from -22.6% to +13.7%, which is wider range than that in Japan. The coefficient of variation for the AEP was 22.7%, which is about twice of that for the yearly average wind speed. Therefore, for estimating the wind energy potential accurately at a given site, the wind data should be analyzed over a long-term period based on the data from the meteorological station.

• The Journal of Korean Society for Radiation Therapy
• /
• v.29 no.2
• /
• pp.75-81
• /
• 2017

Purpose: To evaluate the reproducibility of image-guided radiotherapy using ultrasonography which is non-invasive, without radiation exposure for prostate cancer patients. Materials and Methods: We analyzed the setup variation of 1,105 images for 26 prostate cancer patients and the mean, standard deviation and 3D-error in AP, RL and SI directions. Setup variations were classified 0-1 mm, 1-3 mm, 3-5 mm, 5 mm and more. Results: The mean and standard deviation of setup variation in AP, RL and SI directions was $1.87{\pm}1.36mm$, $1.73{\pm}1.22mm$ and $2.01{\pm}1.40mm$. The 3D-error in AP, RL and SI directions was $3.63{\pm}1.63mm$. The frequency of setup variation in AP direction was 29 % in the range from 0 mm to 1 mm, 50.2 % in the range from 1 mm to 3 mm, 19.6 % in the range from 3 mm to 5 mm and 1.3 % in the range of 5 mm or more. In RL direction, the frequency was 31.3 % in the range from 0 mm to 1 mm, 52.5 % in the range from 1 mm to 3 mm, 15.8 % in the range from 3 mm to 5 mm and 0.5 % in the range of 5 mm or more. SI direction, the frequency of errors in the range from 0 mm to 1 mm was 26.3 %, 50.2 % in the range from 1 mm to 3 mm, 22.4 % in the range from 3 mm to 5 mm, and 1.1 % in the range of 5 mm or more. Conclusion: The setup error was highest in the SI direction of $2.01{\pm}1.40mm$. The frequency in each direction was the highest in more than 50 % in the range from 1 mm to 3 mm. $Clarity^{TM}$ Auto scan is possible to monitoring the motion of the prostate during the treatment and to repositioning the patient. In conclusion real-time image-guided radiotherapy using ultrasonography will be increase the reproducibility of radiation therapy.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.6
• /
• pp.514-519
• /
• 2012

Abalone culture is one of important coastal fisheries off Wando in the southeast coast of Korea. Since cage culture for abalones was popularized, Understanding of temperature variation, which is important to raise abalones and to prevent their mass mortalities, is necessary. We analyzed temperature data from 2005 to 2009 obtained at Sinji-do and Cheongsan-do off Wando. Sinji-do, which is relatively close to land, had yearly wide range of temperature and rate of temperature variation. It is likely to be caused by heating of solar radiation in summer and cooling in winter at the shallow area. Rate of temperature variation in autumn was higher than that in spring. In summer short term variation of temperature corresponding tidal period was distinguished clearly. Diurnal temperature range, abrupt temperature change, was larger open sea. Comparison between temperatures of two stations and favorable raising conditions of abalones showed that Cheongsan-do, located out to sea, appears to be more appropriate than Sinji-do.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.94-94
• /
• 2017

Oryza sativa and Oryza glaberrima are rice cultivars distributed in Asia and Africa. There are several differences between these cultivars in morphological characteristics such as panicle structure and especially the secondary branch number of O. glaberrima is less than that of O. sativa. Generally, branch number of panicle related to a large vascular bundle number (VBN) among O. sativa and there is a wide variation of the VBN of the peduncle from where the bundles enter into the rachis branches. However, there is less information about VBN in O. glaberrima and also the relationship between VBN and branch numbers, the primary branch number (PBN) and secondary branch number (SBN). Additionally, the genetic factor for VBN and branch number in O. glaberrima is not completely exploited. In this study, phenotypic variation for VBN and panicle structure were investigated using a set of 40 $BC_3$ -derived from IRGC 104038 (O. glaberrima from Senegal) and 35 $BC_4$ -derived from IRGC103777 (O. glaberrima from Mali) introgression lines with a genetic background of japonica rice Taichung 65. Taichung 65 had 11.8 PBN, 16.0 SBN and 11.5 VBN, while IRGC 103777 had 12.0 PBN, 15.0 SBN and 15.3 VBN. The introgression lines derived from IRGC 104038 had range from 9.0 to 14.4 in the PBN, range from 9.6 to 33.5 in the SBN and range from 9.8 to 14.8 in the VBN. Additionally, the introgression lines derived from IRGC 103777 had range from 9.0 to 18.5 in the PBN, range from 10.3 to 39.0 in the SBN and range from 9.0 to 15.3 in the VBN. Among two set of introgression lines, there are significant correlation between VBN and PBN. Multiple introgression lines indicated higher PBN, SBN and VBN than Taichung 65 and these examined characteristics are supposedly controlled by quantitative traits loci. The genetic factor related to VBN and panicle architecture can be revealed using segregating population in future study.

• Journal of Environmental Health Sciences
• /
• v.18 no.1
• /
• pp.63-68
• /
• 1992

This study was performed to investigate the seasonal variation of the composition of domestic solid wastes and the characteristics of the leachate sampled in In-Cheon sanitary landfill site. The results were as follows 1. Combustible part was larger than incombustible part of the domestic solid wastes in spring and sumer. 2. The food waste was major source of solid wastes in In-Cheon city as 36.5%, and its variation by seasons was negligible. 3. BOD of the leachate was in the range of 853~7, 350mg/l, and fluctuated by seasons. 4. The mean of COD$_{cr}$ Was 5, 044mg/l, the mean of COD$_{Mn}$ was 2, 212mg/l. Namely, the method by $K_{2}Cr_{2}O_{7}$ was more sensitive than the method by KMnO$_{4}$. 5. TOC was in the range of 773~3, 958mg/l, it was lower than BOD.

• Journal of Korean Society for Atmospheric Environment
• /
• v.13 no.4
• /
• pp.297-305
• /
• 1997

The experimental study by use of SPCP was fulfilled to remove toluene emitted from various industrial processes. First of all, discharge characteristic was experimented as the change of applied voltage and frequency. Then toluene removal characteristic was tested with the analysis of by-products. As a result, optimum electrical discharge condition was from 20.0 kHz to 25.0 kHz of frequency and from 3.5 kV to 4.0 kV of voltage range. The variation of applied voltage had a more important effect on the removal characteristic of toluene than the frequency variation. The toluene removal efficiency was proportioned to ozone concentration and retention time on discharge plate. It was dropped as increase of toluene concentration, but total treated volume of tolene per power consumption was high. The decomposed toluene was transformed to $CO, CO_2$ and particulates, and the rate of transformation to particulates was higher than CO and $CO_2$ at high toluene concentration. Particulates were increased from 0.017 $\mum$ to 0.3 $\mum$ range of size distribution.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1838-1842
• /
• 2004

Gain and phase margins of a first order plus delayed time (FOPDT) process controlled by generalized predictive controller (GPC) are related to the control parameters ${\lambda}$ (control move suppression parameter) and ${\alpha}$ (smoothing filter coefficient) and the normalized delay of the process. Variation ranges of gain and phase margins are determined. It is shown that the margins cannot be assigned independently for a wide range of variation and the range is narrowing by increase of the normalized delay of the process. And finally curves are given to use for adjustment of the controller parameters in order to obtain a specific pair of gain and phase margins.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.11
• /
• pp.1132-1142
• /
• 1991

This paper proposed a method of feature parameter extraction for shape information analysis of moving object. In the 2-D plane, moving object are extracted by the difference method. Feature parameters of moving object are chosen area, perimeter, a/p ratio, vertex, x/y ratio. We changed brightness variation from the range of 600Lux to the 1400Lux and then determined Permissible Error range of feature parameter due to the brightness variation. So as to verify the validity of proposed method, experiment are performed with a toy car and it's results showed that decision error was less than 6%.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.110-115
• /
• 2006

We conducted a sensitivity analysis of the simulated moving bed (SMB) chromatography with the case model of the separation of two amino acids phenylalanine and tryptophan. We consider a four-zone SMB chromatography where the triangle theory is used to determine the operating conditions. Competitive Langmuir isotherm model was used to determine the adsorption isotherm. The finite difference method is used to solve nonlinear partial differential equation (PDE) systems numerically. We examined the effects of alterations in the operating conditions(feed-extract, feed-raffinate, eluent-extract, eluent-raffinate, recycle, and switching time) and the adsorption isotherm parameters (Langmuir isotherm parameters a and b) on SMB efficiency. The variation range of operating conditions and Langmuir isotherm a was between -50 and 50% of original value and the variation range of the Langmuir isotherm b was between $2.25^{-5}$ and $2.25^5$ times of original value.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.374-379
• /
• 2001

In this paper, a novel design algorithm of speed controller for an Induction motor with the inertia variation is proposed. The main contribution of our work is a very robust, reliable and stable procedure for setting of the PI gains against the specified range of the inertia variation of an induction motor using Kharitonovs robust control theory. Therefore, the basic segment of controller design, the variation of induction motor inertia is estimated by the RLS (Recursive least square) method. PI based speed controller is widely used in industrial application for its simple structure and reliable performance. In addition the Kharitonov robust control theory is used for verification stability of closed-loop transfer function. The performance of this proposed design method is proved by digital simulation and experimentation with high performance DSP based induction motor driving system.