• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.4
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• pp.84-89
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• 2024

Light is an important component among which plays a crucial role in determining the production and quality of fruit trees. Since the disturbance of light directly leads to reduced photosynthetic efficiency, their damage can be increased especially in fruit trees such as Japanese apricots with a short growing time. In this study, we investigated how the effects of shading condition can affect the production and quality of Japanese apricots according to increased damages by light disturbance in the main orchard complex. The average photosynthetically active radiation (PAR) level in Japanese apricots was rapidly dropped as the shading time was increased compared to the control (304 μmol/m²/s) and the PAR level decreased to 142 μmol/m²/s after shaded for eight hours. The maximum photosynthetic efficiency, with a PAR value of 900 to 1,000 μmol/m²/s, corresponds to the time period without shading and the time period with 2 hours of shading, and these times range from 11 a.m. to 3 p.m. And the time period for shading for 4 hours was from 1:00 p.m. to 2:00 p.m., and under conditions of shading for 6 and 8 hours, the effect was a low amount of light. There was no difference in the weight of Japanese apricots during 2 hours shading time, however, it was significantly reduced as shading time were increased. The difference of the acid content and L/D ratio was not significant on shading time, but the SSC was decreased as times going on. In conclusion, our results indicate that the shading for more than 2 hours make negative effects to decrease the weight and SSC and the yield and affects directly to drop in fruit quality.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.185-198
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• 2001

This study was conducted to reveal the effects of local climatic conditions on reproductive growth in a mature stand of Korean white pine based on climatic estimates. For this, the reproductive growth such as production and characteristics of cone and seed were first measured and summarized for seven years from 1974 to 1980. The local climatic conditions in the study site were also estimated by both a topoclimatological method and a spatial statistical technique. The local climatic conditions were then correlated with and regressed on the growth factors to reveal the relationships between the climatic estimates and the reproductive growth. Average number of conelet formation per tree showed highly negative correlation with some climatic variables related to minimum temperature in the year of flower bud differentiation. Especially, the most significant negative correlation were found between average of the minimum temperature for June and July of flower bud differentiation year and the number of conelet formation. There was no significant correlation between the number of cone production and climatic variables. However, total precipitation from December of the flowering year to February of the cone production year showed the most high correlation (r=0.6036) with the number of cone production. It was found that significant climatic variables affecting the amount of cone drop and cone drop percentage were the sum of cloudy days from June of the flowering year to August of the cone production year. Positive correlation was significantly recognized between the average weight of empty seed per cone and total precipitation from December of the flowering year to February of the cone production year. For the percentage of empty seed, five climatic variables among 19 variables were significantly correlated at 10% level. The average weight of a cone showed negative correlation with total precipitation from June of the flowering year to August of the cone production year. It was also found that average weight of a seed had highly negative correlation with total precipitation from December of the flowering year to February of the cone production year. The average weight of cone coat was negatively correlated with two climatic variables derived from clear days, which are sum of clear days from November of the flowering year to March of the cone production year and sum of clear days from December of the flowering year to February of the cone production year. On the other hand, it showed positive correlation with mean temperature of May in the flowering year. The exactly same results were obtained in correlation analysis for the percentage of cone coat.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.267-274
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• 2022

The effect of year, varieties, nitrogen application, and transplant time were examined in relation to rice of protein. An experiment was conducted using 12 rice varieties to investigate the effect of management and weather conditions on brown rice protein of during the filling stage. The transplanting time was set to be three groups including early, medium, and late timing. The nitrogen application was set to be 0 N kg / 10a, 9N kg / 10a and 18 N kg / 10a to examine the effect of fertilizer management on protein content. Field experiments were conducted in three growing seasons including 2019, 2020, and 2021. The brown rice of protein content were 5.7%, 5.9%, and 6.6% under early, medium, and late transplanting time conditions, respectively. The protein content differ by variety. For example, Chucheong, Hopum, Ilpum, Mipum, Odae, Saenuri, and Saeilmi had more than 6.1%, and Chindeul, Shindongjin, Samkwang, Unkwang, Younhojinmi were less than 6.1%. Nitrogen content was 5.7% for 0kgN /10a, 6.1% for 9kgN /10a, and 6.8% for 18kgN /10a. The contribution of the characteristics to the protein content was highest in nitrogen content (38.8%), followed by transplanting time (13.7%), variety (8.2%), and year (3.5%). The average temperature for 20 days after heading time was the highest (9.3%), followed by sunshine duration (3.9%) and solar radiation (3.5%). Our results revealed that brown rice protein content was determined to be affected by changes in average temperature, sunshine duration and solar radiation for 20 days after heading time. This suggested that assessment of temperature and solar radiation after heading time would indicate the degree of rice quality in terms of protein.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.1-7
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• 2001

This paper presents a 'consequence analysis' for vapor cloud explosions caused by heavy gas leakages from commercially used storage tanks at petrochemical plants. Particularly, this paper emphasizes on evaluating the results of various vapor cloud explosion accidents from Butane storage tanks. Also this paper analyses the impact of variables on the accidents in order to acquire the optimum conditions for variables. $SuperChems^{TM}$ Professional Edition was applied to analyse the impact (If atmospheric and other variables in the situation where vapor cloud continuously disperses from the ground level. Under the assumption that practical operating conditions are selected as a standard condition, and Butane leaks from the storage tank for 15 minutes, the results show that the maximum distance of LFL (Lower Flammable Limit) was 52 meters and overpressure by the vapor cloud explosion was 1 psi at 128.2 meters. It is observed that the impact of the variables on accidental Butane storage tank leakage mainly varied upon atmospheric stability, wind velocity, pipe line size, visible length, etc., and changes in the simulation result occurred as the variables varied. The maximum distance of the LFL (Lower Flammable Limit) increased as the visible length became shorter, the size of the leak became larger, the wind velocity was decreased, and the climatic conditions became more stable. Thus, by analysing the variables that influence the simulation results of explosions of Butane storage tanks containing heavy gases, I am presenting the most appropriate method for 'consequence analysis' and the selection of standards for suitable values of variables, to obtain the most optimal conditions for the best results.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.26-67
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• 2020

Synthetic Aperture Radar(SAR) is able to photograph the earth's surface regardless of weather conditions, day and night. Because of its possibility to search for hydrological factors such as soil moisture and groundwater, and its importance is gradually increasing in the field of water resources. SAR began to be mounted on satellites in the 1970s, and about 15 or more satellites were launched as of 2020, which around 10 satellites will be launched within the next 5 years. Recently, various types of SAR technologies such as enhancement of observation width and resolution, multiple polarization and multiple frequencies, and diversification of observation angles were being developed and utilized. In this paper, a brief history of the SAR system, as well as studies for estimating soil moisture and hydrological components were investigated. Up to now hydrological components that can be estimated using SAR satellites include soil moisture, subsurface groundwater discharge, precipitation, snow cover area, leaf area index(LAI), and normalized difference vegetation index(NDVI) and among them, soil moisture is being studied in 17 countries in South Korea, North America, Europe, and India by using the physical model, the IEM(Integral Equation Model) and the artificial intelligence-based ANN(Artificial Neural Network). RADARSAT-1, ENVISAT, ASAR, and ERS-1/2 were the most widely used satellite, but the operation has ended, and utilization of RADARSAT-2, Sentinel-1, and SMAP, which are currently in operation, is gradually increasing. Since Korea is developing a medium-sized satellite for water resources and water disasters equipped with C-band SAR with the goal of launching in 2025, various hydrological components estimation researches using SAR are expected to be active.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.298-302
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• 2016

This study evaluated the effect 3 types of conditioning (Untreated, Impeller, Roller) and the number of times for tedding (rake-teder) performed in one day on the drying rate of tall fescure hay. The experiment was performed at The forage site of Cheonan-si seongwhan-eup National Institute of Animal Sciencee. It took 3 days to make tall fescue hay. The Impeller and Roller conditioning types shortened the haymaking period by 1 day compared to untreated hay. Impeller and roller samples had less than 20% of water content by the $23^{rd}-day$ at 13 o'clock. Tedding frequency failed to affect haymaking. There was no correlation between the three types of conditioning or tedding frequency and acid digestible fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDF), crude protein (CP), or relative feed value (RFV) in tall fescue hay. CP was 12.5~12.9% for the three types of conditioner with 1 or 2 times of tedding a day, Threrfore, conditioner types and gedding frequency had no significant effect on CP.

• Journal of Korea Water Resources Association
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• v.50 no.1
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• pp.37-53
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• 2017

Pan evaporation has been used as an indirect method for the estimation of reservoir evaporation. Therefore, in this study, pan evaporation estimation equations using only temperature data were suggested in the case that available meteorological data is limited. A formula for estimating the pan evaporation were suggested by comparing estimated pan evaporation with measured pan evaporation in 12 study areas in Korea. The suggested pan evaporation equations were verified in 44 study areas by comparing not only with temperature-based equations but also with equations using other meteorological data (temperature, wind speed, relative humidity, and sunshine duration). The study results indicate that the suggested equations in this study provide much better pan evaporation estimates, compared with other temperature-based equations. Overall, the suggested equations provide appropriate pan evaporation estimates in most of 56 study areas. Therefore, the suggested equations using only temperature data in this study are considered appropriate for the estimation of pan evaporation in Korea especially in the case that available meteorological data is limited. In the future, using the air temperature and pan evaporation data measured at the reservoir, further research is needed to examine the applicability of suggested equations for the estimation of reservoir evaporation.

• Journal of the Korean earth science society
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• v.38 no.7
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• pp.481-495
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• 2017

The purpose of this study is to investigate and analyze the relationship between meteorologicalclimatic factors and fruit property data from Aronia sampling points during May to August 2016 in the Danyang area. For this purpose, we investigated the meteorological factor, the physicalchemical property of fruit and soil, and the property change of fruit according to the setting of rain and daylight shielding from Aronia sampling points. The result indicate that first, meteorologicalclimatic factors such as the maximum air temperature, the accumulated precipitation, the relative humidity, and daylight hours are a positive influence on products and maintenance of quality of Aronia as well as a suitable field for cultivating Aronia in the Danyang. However, a strong wind in April and May deeply affects the falling phenomenon of the flowering and blooming season. Second, the quality and products of Aronia show the high correlation coefficients of more than 0.9 with agricultural meteorologicalclimatic factors such as daily maximum temperature, daily soil temp, daily soil pH, cumulated precipitation, and daily soil humidity. Also, they can be predicted by the regression equations using these factors. Third, it is necessary to maintain the rain shielding in these fields because antocyanin and saccharinity components within Aronia decreased in case of heavy rainfalls. And, the result of regression analysis saccharinity and antocyanin within aronia from normal fields and rain shieldingfields at Aronia sampling points show a high correlation, respectively.

• Journal of the Korean earth science society
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• v.40 no.6
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• pp.599-605
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• 2019

Rice yield (kg 10a^-1) in South Korea was estimated by meteorological variables that are influential factors in crop growth. This study investigated the possibility of anticipating the rice yield variability using a simple but an efficient statistical method, a multiple linear regression analysis, on the basis of the annual variation of meteorological variables. Due to heterogeneous environmental conditions by region, the yearly rice yield was assessed and validated for each province in South Korea. The monthly mean meteorological data for the period 1986-2018 (33 years) from 61 weather stations provided by Korean Meteorological Administration was used as the independent variable in the regression analysis. An 11-fold (leave-three-out) cross-validation was performed to check the accuracy of this method estimating rice yield at each province. This result demonstrated that temporal variation of rice yield by province in South Korea can be properly estimated using such concise procedure in terms of correlation coefficient (0.7, not significant). Furthermore, the estimated rice yield well captured spatial features of observation with mean bias of 0.7 kg 10a^-1 (0.15%). This method may offer useful information on rice yield by province in advance as long as accurate agro-meteorological forecasts are timely obtained from climate models.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.1-7
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• 2001

This experiment was carried out to investigate the effects of shading treatments and harvesting methods on the growth of Eleutherococcus senticosus, which was known as the medicine of anticancer, anti-stress, hepatic detoxification activity, immunoactivity, and tonic. Light transmission ratio and air temperature were decreased as $40{\sim}64%$,$1.9{\sim}2^{\circ}C$, respectively, in 30% to 70% shading net treatment compared to non-shading. Fifty percentage shading net treatment was effective for the growth and yield of Eleutherococcus senticosus. During summer Eleutherococcus senticosus was growing under shading net treatment compared to non-shading. Tunnel type was more effective for growth than vertical type in shading method. 30cm length included 2 to 3 nodes cutting from soil surface was the most effective for branching stem length, plant height and yield as harvesting methods.