• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.420-428
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• 2016

For more than 50 years, satellite images have been used to monitor crop growth. Currently, unmanned aerial vehicle (UAV) imagery is being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study refers to the derivation of growth estimating equation for highland Kimchi cabbage using UAV derived normalized difference vegetation index (NDVI) and agro-meteorological factors. Anbandeok area in Gangneung, Gangwon-do, Korea is one of main districts producing highland Kimchi cabbage. UAV imagery was taken in the Anbandeok ten times from early June to early September. Meanwhile, three plant growth parameters, plant height (P.H.), leaf length (L.L.) and outer leaf number (L.N.), were measured for about 40 plants (ten plants per plot) for each ground survey. Six agro-meteorological factors include average temperature; maximum temperature; minimum temperature; accumulated temperature; rainfall and irradiation during growth period. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, $NDVI_{UAV}$ and rainfall in the model explain 93% of the P.H. and L.L. with a root mean square error (RMSE) of 2.22, 1.90 cm. And $NDVI_{UAV}$ and accumulated temperature in the model explain 86% of the L.N. with a RMSE of 4.29. These lead to the result that the characteristics of variations in highland Kimchi cabbage growth according to $NDVI_{UAV}$ and other agro-meteorological factors were well reflected in the model.

• Journal of the Korean Solar Energy Society
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• v.38 no.5
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• pp.11-25
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• 2018

The Ln-least method is commonly used to estimate the Weibull parameters from the observed wind speed data. In previous studies, the bin method has been used to calculate the cumulative frequency distribution for the Ln-least method. The purpose of this study is to obtain better performance in the Ln-least method by applying probability plotting position(PPP) instead of the bin method. Two types of the wind speed data were used for the analysis. One was the observed wind speed data taken from three sites with different topographical conditions. The other was the virtual wind speed data which were statistically generated by a random variable with known Weibull parameters. Also, ten types of PPP formulas were applied which were Hazen, California, Weibull, Blom, Gringorten, Chegodayev, Cunnane, Tukey, Beard and Median. In addition, in order to suggest the most suitable PPP formula for estimating Weibull parameters, two accuracy tests, the root mean square error(RMSE) and $R^2$ tests, were performed. As a result, all of PPPs showed better performances than the bin method and the best PPP was the Hazen formula. In the RMSE test, compared with the bin method, the Hazen formula increased estimation performance by 38.2% for the observed wind speed data and by 37.0% for the virtual wind speed data. For the $R^2$ test, the Hazen formula improved the performance by 1.2% and 2.7%, respectively. In addition, the performance of the PPP depended on the frequency of low wind speeds and wind speed variability.

• Journal of Korea Water Resources Association
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• v.42 no.10
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• pp.857-866
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• 2009

In this study, basic data is consisted annual maximum rainfall at 56 stations that has the rainfall records more than 30years in Korea. The 14 probability distributions which has been widely used in hydrologic frequency analysis are applied to the basic data. The method of moments, method of maximum likelihood and probability weighted moments method are used to estimate the parameters. And 4-tests (chi-square test, Kolmogorov-Smirnov test, Cramer von Mises test, probability plot correlation coefficient (PPCC) test) are used to determine the goodness of fit of probability distributions. This study emphasizes the necessity for considering the variability of the estimate of T-year event in hydrologic frequency analysis and proposes a framework for evaluating probability distribution models. The variability (or estimation error) of T-year event is used as a criterion for model evaluation as well as three goodness of fit criteria (SLSC, MLL, and AIC) in the framework. The Jackknife method plays a important role in estimating the variability. For the annual maxima of rainfall at 56 stations, the Gumble distribution is regarded as the best one among probability distribution models with two or three parameters.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.10 no.2
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• pp.104-120
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• 2006

Background : Pulse-respiration ratio has been used for estimating subject's status in oriental medicine. Pulse and respiration is strongly associated with autonomic nerve system. But there is no research about correlation between pulse-respiration ratio and autonomic nerve system. Objectives : We performed this study to know correlation between pulse-respiration ratio and HRV(heart rate variability) that shows autonomic nerve system status well and to clarify clinical meaning of pulse-respiration ratio. Methods : After subject's 10 minutes rest, we measured subject's ECG, respiration pattern and HRV. In this research, subject's number is 95(Male 50/Female 45). We calculated pulse-respiration ratio from ECG and respiration pattern. Then, we analyzed correlation between pulse-respiration ratio and HRV parameters in all subjects, 2 group divided by Wan-Maek(P-R ratio 4.28). We tried to compare HRV parameters among Wan-Maek, Sak-Maek and Ji-Maek group. Correlation analysis between pulse-respiration Ratio and Pulse rate, respiration rate is performed. Finally correlation analysis between Respiration and HRV parameters in all subjects, 2 group divided by Wan-Maek(4.28) is studied. Results : 1. Mean pulse-respiration is 4.10${\pm}$0.67, Mean pulse rate is 68.06${\pm}$7.82bpm, Mean respiration rate is 16.81${\pm}$2.72 times per minute in all subjects. 2. Correlation analysis between pulse-respiration ratio and HRV parameters of high pulse-respiration ratio group is not significant. But, in low pulse-respiration ratio group, HFnorm(correlation coefficient 0.306, p= 0.018), lnHF (0.308, p=0.002) is significantly correlated with pulse-respiration ratio. 3. Comparison of HRV parameters among Wan-Maek, Sak-Maek and Ji-Maek Group is not significant. 4. Pulse-respiration ratio is more affected by respiration rate(correlation coefficient-0.17, p=0.000) than pulse rate (correlation coefficient 0.396, p=0.000). 5. Correlation analysis between respiration rate and HRV parameters of high pulse-respiration ratio group is not significant. But, in low pulse-respiration ratio group, HFnorm (correlation coefficient -0.327, p=0.011), LF/HF(0.346, p=0.007), lnHF (-0.355, p=0.006) are significantly correlated with respiration rate. Conclusion : Pulse-respiration ratio and parasympathetic index has positive correlation. The closer Wan-Maek, The higher parasympathetic index in low pulse-respiration ratio group. Respiration rate is more related with pulse-respiration ratio than pulse rate. Respiration is negatively correlated with autonomic parameters. And the slower respiration, the higher parasympathetic index in low pulse-respiration ratio group.

• Toxicological Research
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• v.18 no.1
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• pp.65-71
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• 2002

A benchmark dose (BMD) approach has been evaluated us a replacement for the traditional NOAEL methodology currently being wed to assess the noncancer effects of toxicants. The endocrine disrupt-ing effect of endosulfan which showed decrement of sperm count and testicular testosterone level in animals, was currently reported. The amount of endosulfan used as pesticide in the country has been continuously increased. The aim of this study was to suggest the permissible intake level (PIL), corresponding to Accept-able Daily Intake (ADI), based on endocrine disrupting effect wing BMD. Various animal data were collected by consideration of critical effect showing endocrine disruption and an animal data for reproductive toxicity was selected. The Power model from BMD software for induction of $BMD_10$ having meaning which is the dose at the 95% lower confidence limit on a 10% response was used due to that the form of selected dose-response animal data was continuous data. The $BMD_10$ was estimated to be 0.393 mg/kg/day based on reproductive toxicity showing decrement of sperm count. The permissible intake level (PIL) was calculated by dividing the $BMD_10$ by the uncertainty factors of 100 with consideration of from animal to human and human variability. The PIL as 0.004 mg/kg/day was compared with traditional ADI as 0.006 mg/kg/day based on the incidence of marked progressive glomerulonephrosis and blood vessel aneurysm in males.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.143-153
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• 2008

The purpose of this paper is to evaluate impacts of ENSO on frequency and spatial distribution of rainfall in South Korea. In this paper, First, rainfall data in 60 climate stations were categorized into Warm(El Nino), Cold(La Nina), Normal episodes based on the Cold & Warm Episodes by Season, then 100 years of daily rainfall data were generated for each episodic events(El Nino, La Nina, Normal) using Markov Chain model. Finally, Estimating frequency based flood and comparison for each episodes were conducted. From the results, it shows that there are significant changes in the rainfall frequency and the spatial distribution of rainfall among Warm(EL Nino), Cold(La Nina) and Normal episodes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.272-272
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• 1996

While ranitidine is well known to be absorbed rapidly, the underlying cause of variable bioavailability in intra- and inter-subjects has not been clarified yet. Intestinal permeability is a key controlling factor for oral absorption of highly soluble drugs, In the present study, intestinal ferfusions have been conducted to determine the intestinal permeabilities(Peffs) of ranitidine in the rats, dogs and humans and compared to the estimated fractions of dose absorbed (FAs) in humans. A new in vivo methodology, using a regional segmental perfusion technique, has been used in the dogs and humans. In situ single-pass perfusion experiments have been performed in the rats. In the dog and human studies, perfusion experiments have been conducted on two periods to determine the intrasubject variability, There was low significant intrasubject variation as compared to intersubject variation. The Peffs of ranitidine were 33%, 51%, and 45% inthe rats, dogs and humans, respectively. The FAs were approximately the same for all three species models, suggesting rats and dogs are good animal models for estimating the oral absorption of ranitidine in humans. In addition, the estimated extent of absorption of this drug is consistent with the average bioavailability, indicating that ranitidine has permeability-limited absorption characteristics. Supported by FDA Grant FD01462.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.107-114
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• 2020

This study was conducted to investigate the variation in nutrient composition of oilseed meals and to develop prediction equations for amino acid concentrations. Energy and nutrient contents were determined in a total of 1,380 feed ingredient samples including copra byproducts, corn distillers, dried grains with solubles, palm kernel byproducts, and soybean meal. The ingredient samples were imported to the Republic of Korea between 2006 and 2015. Data were analyzed using the MIXED procedure of SAS. The regression procedure of SAS was used to generate the prediction equation for the lysine concentration using the crude protein (CP) concentration as an independent variable. The concentrations of moisture, gross energy, CP, ether extract, crude fiber, ash, calcium, phosphorus, lysine, methionine, cysteine, and threonine in tested oilseed meals differed (P<0.05) depending on producing countries. The prediction equations for amino acid concentrations (% as-is basis) in the oilseed meals are: lysine = -1.08 + 0.080 × CP (root mean square error = 0.244, R² = 0.924, and P<0.001); threonine = -0.297 + 0.044 × CP (root mean square error = 0.099, R² = 0.958, and P<0.001). In conclusion, energy and nutrient compositions vary in the oilseed meals depending on the producing countries. Moreover, the crude protein concentration can be used as a suitable independent variable for estimating lysine and threonine concentrations in the oilseed meals.

• Journal of Community Nutrition
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• v.5 no.2
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• pp.72-82
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• 2003

We here outlined our study on the variations in intake of nutrients based on four season 7 consecutive day weighed diet records (WDRs) from 80 Japanese female dietitians in 1996 - 1997. Furthermore, we reviewed Japanese, Korean and international articles investigating variability in consumption of foods as well as nutrients. The relative contributions of variation for all nutrients by person were greater than those by day, week and season. Within individual variances were greater than that between individual variances, being generally observed in Korea and in the world. The ratios of within- vs. between-individual variations ranged from 1.3-26.9 in our study, the ratios being greatest in Korean, followed by Japanese and western people. Based on within individual coefficients of variation, minimal days necessary for estimating nutrient consumption per person within 10％ (20％) of the true mean with 95％ confidence intervals were estimated. They ranged from 10-35 (3-9) days for energy and major nutrients and 15-640(4-160) days for micro-nutrients. Two Japanese studies reported that the ratios for foods were as a whole greater than those for nutrients, except for cereals, rice and milk. (J community Nutrition 5(2) : 72-82,2003).

• Environmental Engineering Research
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• v.18 no.3
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• pp.151-156
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• 2013

Several soil properties were studied from three young created mitigation wetlands (<10 years old), which were hydrologically comparable in the Piedmont region of Virginia. The properties included soil organic matter (SOM), soil organic carbon (SOC), pH, gravimetric soil moisture, and bulk density ($D_b$). No significant differences were found in the soil properties between the wetlands, except SOM and SOC. SOM and SOC indicated a slight increase with wetland age; the increase was more evident with SOC. Only about a half of SOC variability found in the wetlands was explained by SOM ($R^2$ = 0.499, p < 0.05). The majority of the ratios of SOM to SOC for these silt-loam soils ranged from 2.0 to 3.5, which was higher than the 1.724 Van Bemmelen factor, commonly applied for the conversion of SOM into SOC in estimating the carbon storage or accumulation capacity of wetlands. The results may caution the use of the conversion factor, which may lead to an overestimation of carbon sequestration potentials of newly created wetlands. SOC, but not SOM, was also correlated to $D_b$, which indicates soil compaction typical of most created wetlands that might limit vegetation growth and biomass production, eventually affecting carbon accumulation in the created wetlands.