• Korean Journal of Soil Science and Fertilizer
• /
• v.23 no.2
• /
• pp.87-93
• /
• 1990

A statistical model to predict soil temperature from the ambient meteorological factors including mean, maximum and minimum air temperatures, precipitation, wind speed and snow depth combined with Fourier time series expansion was developed with the data measured at the Suwon Meteorolical Service from 1979 to 1988. The stepwise elimination technique was used for statistical analysis. For the yearly oscillation model for soil temperature with 8 terms of Fourier expansion, the mean square error was decreased with soil depth showing 2.30 for the surface temperature, and 1.34-0.42 for 5 to 500-cm soil temperatures. The $r^2$ ranged from 0.913 to 0.988. The number of lag days of air temperature by remainder analysis was 0 day for the soil surface temperature, -1 day for 5 to 30-cm soil temperature, and -2 days for 50-cm soil temperature. The number of lag days for precipitaion, snow depth and wind speed was -1 day for the 0 to 10-cm soil temperatures, and -2 to -3 days for the 30 to 50-cm soil teperatures. For the statistical soil temperature prediction model combined with the yearly oscillation terms and meteorological factors as remainder terms considering the lag days obtained above, the mean square error was 1.64 for the soil surfac temperature, and ranged 1.34-0.42 for 5 to 500cm soil temperatures. The model test with 1978 data independent to model development resulted in good agreement with $r^2$ ranged 0.976 to 0.996. The magnitudes of coeffcicients implied that the soil depth where daily meteorological variables night affect soil temperature was 30 to 50 cm. In the models, solar radiation was not included as a independent variable ; however, in a seperated analysis on relationship between the difference(${\Delta}Tmxs$) of the maximum soil temperature and the maximum air temperature and solar radiation(Rs ; $J\;m^{-2}$) under a corn canopy showed linear relationship as $${\Delta}Tmxs=0.902+1.924{\times}10^{-3}$$ Rs for leaf area index lower than 2 $${\Delta}Tmxs=0.274+8.881{\times}10^{-4}$$ Rs for leaf area index higher than 2.

• Progress in Medical Physics
• /
• v.26 no.3
• /
• pp.168-177
• /
• 2015

For evaluating the treatment planning accurately, the quality assurance for treatment planning is recommended when patients were treated with IMRT which is complex and delicate. To realize this purpose, treatment plan quality assurance software can be used to verify the delivered dose accurately before and after of treatment. The purpose of this study is to evaluate the accuracy of treatment plan quality assurance software for each IMRT plan according to MLC DLG (dosimetric leaf gap). Novalis Tx with a built-in HD120 MLC was used in this study to acquire the MLC dynalog file be imported in MobiusFx. To establish IMRT plan, Eclipse RTP system was used and target and organ structures (multi-target, mock prostate, mock head/neck, C-shape case) were contoured in I'mRT phantom. To verify the difference of dose distribution according to DLG, MLC dynalog files were imported to MobiusFx software and changed the DLG (0.5, 0.7, 1.0, 1.3, 1.6 mm) values in MobiusFx. For evaluation dose, dose distribution was evaluated by using 3D gamma index for the gamma criteria 3% and distance to agreement 3 mm, and the point dose was acquired by using the CC13 ionization chamber in isocenter of I'mRT phantom. In the result for point dose, the mock head/neck and multi-target had difference about 4% and 3% in DLG 0.5 and 0.7 mm respectively, and the other DLGs had difference less than 3%. The gamma index passing-rate of mock head/neck were below 81% for PTV and cord, and multi-target were below 30% for center and superior target in DLGs 0.5, 0.7 mm, however, inferior target of multi-target case and parotid of mock head/neck case had 100.0% passing rate in all DLGs. The point dose of mock prostate showed difference below 3.0% in all DLGs, however, the passing rate of PTV were below 95% in 0.5, 0.7 mm DLGs, and the other DLGs were above 98%. The rectum and bladder had 100.0% passing rate in all DLGs. As the difference of point dose in C-shape were 3~9% except for 1.3 mm DLG, the passing rate of PTV in 1.0 1.3 mm were 96.7, 93.0% respectively. However, passing rate of the other DLGs were below 86% and core was 100.0% passing rate in all DLGs. In this study, we verified that the accuracy of treatment planning QA system can be affected by DLG values. For precise quality assurance for treatment technique using the MLC motion like IMRT and VMAT, we should use appropriate DLG value in linear accelerator and RTP system.

• Journal of Korea Water Resources Association
• /
• v.45 no.3
• /
• pp.301-316
• /
• 2012

Two models, TANK and SWAT (Soil and Water Assessment Tool) were compared for simulating natural flows in the Paldang Dam upstream areas of the Han River basin in order to understand the limitations of TANK and to review the applicability and capability of SWAT. For comparison, simulation results from the previous research work were used. In the results for the calibrated watersheds (Chungju Dam and Soyanggang Dam), two models provided promising results for forecasting of daily flows with the Nash-Sutcliffe model efficiency of around 0.8. TANK simulated observations during some peak flood seasons better than SWAT, while it showed poor results during dry seasons, especially its simulations did not fall down under a certain value. It can be explained that TANK was calibrated for relatively larger flows than smaller ones. SWAT results showed a relatively good agreement with observed flows except some flood flows, and simulated inflows at the Paldang Dam considering discharges from upper dams coincided with observations with the model efficiency of around 0.9. This accounts for SWAT applicability with higher accuracy in predicting natural flows without dam operation or artificial water uses, and in assessing flow variations before and after dam development. Also, two model results were compared for other watersheds such as Pyeongchang-A, Dalcheon-B, Seomgang-B, Inbuk-A, Hangang-D, and Hongcheon-A to which calibrated TANK parameters were applied. The results were similar to the case of calibrated watersheds, that TANK simulated poor smaller flows except some flood flows and had same problem of keeping on over a certain value in dry seasons. This indicates that TANK application may have fatal uncertainties in estimating low flows used as an important index in water resources planning and management. Therefore, in order to reflect actually complex and complicated physical characteristics of Korean watersheds, and to manage efficiently water resources according to the land use and water use changes with urbanization or climate change in the future, it is necessary to utilize a physically based watershed model like SWAT rather than an existing conceptual lumped model like TANK.

• Journal of Korean Public Health Nursing
• /
• v.15 no.2
• /
• pp.301-313
• /
• 2001

This study was to explore the relationship between nurses' personality type and their job satisfaction level. The subjects of the study were the 364 nurses who were serving at the general surgical department, psychiatric department, pediatric department and emergency room. The hospitals for which they were working were four university hospitals in Daegu and Busan, and six other university hospitals in Seoul were selected as sample hospitals. For data collection, questionnaires were self-reported to the subjects, under their agreement, from May to June, 2000. The following two instruments were used in the study: One was MBTI Test whose Korean version designed and verified to reliability and validity by Kim Jung Taek and Shim Hae Sook(1990): the other was the Nursing Job Satisfaction Instrument, 'The Index of Work Satisfaction' developed by Slavitt, et al.., (1978). The data were analyzed by frequency, t-test, one-way variance analysis, scheffe's post hoc contrast, and Pearson correlation coefficient with SPSS Win 10.0 program. The results this study were as follows ; 1. As a result of testing nurse's personality type by function at each career, it's found that the most personality type was expressed by the ST-type$(37.3\%)$ at 1-5 years, the SF-type$(29.4\%)$ at 6-10 years, the ST-type$(43.3\%)$ at more than 11 years. 2. As a result of testing the disparity in job satisfaction according to career, it appeared that the 6-10 years group showed higher job satisfaction, followed by the 6-10 years$(119.6\%),\;1-5 years(118.6\%)\;and\;more\;than\; 11 years(117.7\%)$ groups. 3. As a result of testing job satisfaction level according to nurse's personality type by function at each career, it's found that the most job satisfaction was expressed by the SF-type(F=8.50, p=0.00l) at 1-5 years. the ST-type(F=30.61, p=0.001) at 6-10 years. the SF-type(F=4.98, p=0.003) at more than 11 years groups. 4. As a result of testing a significant correlation between nurse's personality type by function and job satisfaction level. the SF(r=0.279, p=0.001) and ST(r=0.222, p=0.001) types showed significant positive correlation. and the NF(r=-0.201, p=0.001) and NT(r=-0.402, p=0.001) types revealed significant negative correlation. The nursing management is likely to be done more effectively, if managers in charge of nursing administration carefully reflect nurses' personal opinions in posting and personnel management, keeping in mind that there is a specific personality type that serves to raise job satisfaction at a specific career.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.8 no.3
• /
• pp.285-294
• /
• 2003

To select an appropriate sampler for the environmental monitoring survey in coastal waters of Saemangeum, Jeollabuk-do, a macrobenthic sampling was conducted in April 2002. Employed samplers were dredge (type Charcot), a semi-quantitative sampler and Smith-McIntyre (SM) and van Veen grab (VV) as quantitative ones. One haul was tried for dredge and 3 replicates (0.1 ㎡${\times}$3) for SM and W at each of 11 stations. Comparisons of sediment volume in sampler bucket and of precision of biological parameters (i.e., density, biomass, species number and diversity index, H') were made between SM and VV. Sediment volume was significantly different (SM > VV) at p-value of 0.0050 (paired t-test) and, in average, 3 replicate samples of SM and VV satisfied a precision level of 0.2 by applying 4th root transformation. Patterns of observed and expected species numbers and H' were compared. Dredge-VV samples showed higher affinity than any other pair. Several dominant species in the area were underestimated in dredge samples (e.g., polychaete Heteromastus filiformis. Aricidea assimilis etc.). Quantifying the agreement pattern of multi-species responses was accomplished by estimating correlations between similarity matrices. Correlation between dredge and VV was slightly higher, but near-per-fect matches were found in general. Different ranks and composition among principal species lists were presumably linked to the effect of penetration depth that differs among samplers. Lower level of some species' abundance in VV samples (ca. 50％ compared with those of SM) was explained in this context. It seem appropriate to regard the effect as a probable cause of relatively higher correlations in dredge-VV, Overall bio-logica1 features indicated that a better choice could be SM in situations of requiring high data quality. The others work well, however, on observing and defining faunal characteristics and their capability cannot be questionted if we do not expect a first-order quality.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.17 no.4
• /
• pp.384-398
• /
• 2015

In this paper, the high-resolution Weather Research and Forecasting/Noah-MultiParameterization (WRF/Noah-MP) modeling system is configured for the Cheongmicheon Farmland site in Korea (CFK), and its performance in land and atmospheric simulation is evaluated using the observed data at CFK during the 2014 special observation period (21 August-10 September). In order to explore the usefulness of turning on Noah-MP dynamic vegetation in midterm simulations of surface and atmospheric variables, two numerical experiments are conducted without dynamic vegetation and with dynamic vegetation (referred to as CTL and DVG experiments, respectively). The main results are as following. 1) CTL showed a tendency of overestimating daytime net shortwave radiation, thereby surface heat fluxes and Bowen ratio. The CTL experiment showed reasonable magnitudes and timing of air temperature at 2 m and 10 m; especially the small error in simulating minimum air temperature showed high potential for predicting frost and leaf wetness duration. The CTL experiment overestimated 10-m wind and precipitation, but the beginning and ending time of precipitation were well captured. 2) When the dynamic vegetation was turned on, the WRF/Noah-MP system showed more realistic values of leaf area index (LAI), net shortwave radiation, surface heat fluxes, Bowen ratio, air temperature, wind and precipitation. The DVG experiment, where LAI is a prognostic variable, produced larger LAI than CTL, and the larger LAI showed better agreement with the observed. The simulated Bowen ratio got closer to the observed ratio, indicating reasonable surface energy partition. The DVG experiment showed patterns similar to CTL, with differences for maximum air temperature. Both experiments showed faster rising of 10-m air temperature during the morning growth hours, presumably due to the rapid growth of daytime mixed layers in the Yonsei University (YSU) boundary layer scheme. The DVG experiment decreased errors in simulating 10-m wind and precipitation. 3) As horizontal resolution increases, the models did not show practical improvement in simulation performance for surface fluxes, air temperature, wind and precipitation, and required three-dimensional observation for more agricultural land spots as well as consistency in model topography and land cover data.

• Journal of Nutrition and Health
• /
• v.53 no.5
• /
• pp.476-487
• /
• 2020

Purpose: This study evaluated the accuracy of the 24-hour diet recall method for estimating energy intakes in elderly women using the doubly labeled water (DLW) method. Methods: The subjects were 23 elderly women with a mean age of 70.3 ± 3.3 years and body mass index (BMI) of 23.9 ± 2.8 kg/㎡. The total energy expenditure (TEE_DLW) was determined by using the DLW and used to validate the 24-hour diet recall method. The total energy intake (TEI) was calculated from the 24-hour diet recall method for three days. Results: TEI (1,489.6 ± 211.1 kcal/day) was significantly lower than TEE_DLW (2,023.5 ± 234.9 kcal/day) and was largely under-reported by -533.9 ± 228.0 kcal/day (-25.9%). The accurate prediction rate of elderly women in this study was 8.7%. The Bland-Altman plot, which was used to evaluate the TEI and the TEE_DLW, showed that the agreement between them was negatively skewed, ranging from -980.8 kcal/day to -86.9 kcal/day. Conclusion: This study showed that the energy intake of elderly women was underreported. Strategies to increase the accuracy of the 24-hour diet recall methods in the elderly women should be studied through analysis of factors that affect underreporting rate. Further studies will be needed to assess the validity of the 24-hour diet recall method in other population groups.

• Journal of Environmental Science International
• /
• v.16 no.5
• /
• pp.571-581
• /
• 2007

The mechanism of water pollution in Lake Shihwa, one of highly eutrophicated artificial lakes in Korea, has been studied using a numerical 3D physical-biochemical coupled model. In this study, the model was applied to estimate the contribution of land-based pollutant load to water quality of heavily polluted Lake Shihwa. The chemical oxygen demand(COD) was adopted as an index of the lake water quality, and the spatial distribution of an average COD concentration during the summer from 1999 to 2000 was simulated by the model. The simulated COD showed a good agreement with the observed data. According to reproducibility of COD, the high-est levels between 8 and 9 mg/L were shown at the inner site of the lake with inflow of many rivers and ditches, while the lowest was found to be about 5 mg/L at the southwestern site near to dike gate. In the pre-diction of water quality of Lake Shihwa, COD showed still higher levels than 3 mg/L in case of reduction of 95% for land-based pollutant load. This suggests that the curtailment of land-based pollutant load is not only sufficient but the improvement of sediment quality or the increase of seawater exchange should be considered together to improve a water quality in Lake Shihwa.

• Journal of Gastric Cancer
• /
• v.7 no.4
• /
• pp.219-227
• /
• 2007

Purpose: Many reconstruction procedures have been developed in order to resolve patient complaints after a total gastrectomy. However, until now, there has been no general agreement with regard to the ideal reconstruction to perform after a total gastrectomy. Moreover, there have been few reports of the long-term effects of different reconstruction procedures. In this study, we compared the long-term nutritional status and quality of life for patients that received either a Roux-en-Y esophagojejunostomy (R-Y), jejunal interposition (JI), jejunal pouch interposition (JPI), or double tract reconstruction (DT), to determine the optimum reconstruction procedure after a total gastrectomy. Materials and Methods: The study consisted of 41 patients younger than 80 years who had undergone a total gastrectomy with curative resection and who had no evidence of recurrence at our hospital between August 2000 and January 2004. The patients were classified into the following four groups, according to the type of reconstruction; simple Roux-en-Y (R-Y group, n=15), jejunal interposition (JI; group, n=8), j Jejunal pouch interposition (JPI group, n=8), double tract interposition (DT group, n=10). The nutritional status was assessed by measuring body weight, serum albumin level, serum hemoglobin level, and the level of serum total protein, and the PNI (Prognostic nutritional index). Quality of life was assessed by GSRS. In addition, endoscopy was performed to confirm the presence of reflux esophagitis. Results: The laboratory findings showed no significant differences between the four groups except for a lower total protein and album level in the DT group after 3 years postoperatively (P=0.006, P=0.033). The percentage of body weight at 1 year, and 3 years postoperatively in the JI group (P=0.013, P=0.011) were significantly less than other groups (P=0.011, P=0.000). The frequency of postoperative symptoms and reflux esophagitis and eating capacity showed no significant differences between the four groups. The GSRS score in the JIP group was significantly better than for the other groups at 1 year, and 3 years postoperatively (P=0.028, P=0.003). Conclusion: We believe that the jejunal pouch interposition is the most useful of the four procedures for improving postoperative quality of life.

• Progress in Medical Physics
• /
• v.24 no.2
• /
• pp.127-132
• /
• 2013

The position of the internal organs can change continually and periodically inside the body due to the respiration. To reduce the respiration induced uncertainty of dose localization, one can use a respiratory gated radiotherapy where a radiation beam is exposed during the specific time of period. The main disadvantage of this method is that it usually requests a long treatment time, the massive effort during the treatment and the limitation of the patient selection. In this sense, the combination of the real-time position management (RPM) system and the volumetric intensity modulated radiotherapy (RapidArc) is promising since it provides a short treatment time compared with the conventional respiratory gated treatments. In this study, we evaluated the accuracy of the respiratory gated RapidArc treatment. Total sic patient cases were used for this study and each case was planned by RapidArc technique using varian ECLIPSE v8.6 planning machine. For the Quality Assurance (QA), a MatriXX detector and I'mRT software were used. The results show that more than 97% of area gives the gamma value less than one with 3% dose and 3 mm distance to agreement condition, which indicates the measured dose is well matched with the treatment plan's dose distribution for the gated RapidArc treatment cases.