• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.365-370
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• 2010

The pollen dispersal by wind can make an important to understanding the viability and evolution of plants in ecological and agricultural science. Modelling can be applied to evaluate concerns about the spread of engineered pollens from genetically modified (GM) crops. Here, we are using gamma model to estimate the level of dispersal distance of pollen in the cross-pollination between two different maize (Zea mays L.) cultivars in GMO field of Korea University during the year 2010. The result of estimation of model indicates maximum pollen dispersal distance of estimated proportion of cross-pollination of maize was reached to 0.1% in 525 meter northwest due to the wind. We identify further measurements necessary to improve the accuracy of the model predictions.

• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.1970-1980
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• 2016

The problem of food deficiency is a major discouragement to many low-income developing countries. Most of these countries experience constant danger of hunger, malnutrition and diseases as they are unable to maintain their food supplies mainly due to lack of arable lands and modern crop, livestock and fishery production technologies. In addition, the pollutants resulting from the secondary industries are becoming another serious issue in their food problems. The pollutants mixed in the sands blowing from the mainland China and the toxic waters flowing in the farm land form the industrialized zones are some of the examples. The Vertical Farm, or Plant Factory, proposed in this study could be the best alternative food production system for them. Vertical farm is an efficient food production system that yields relatively a large volume of food materials without environmental risks. The system does not require a large open space and manpower and can minimize the possibility of infiltration of pollutants. This research describes a basic model of the system focusing on determining the optimal sites for it based on the meteorological data concentrating on the atmospheric pollutants. The types and volume of pollutants are analyzed and identified through the big data obtained, followed by visualization of analysis results and their comparisons for better understanding.

• ALGAE
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• v.27 no.1
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• pp.43-54
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• 2012

A mathematical model of the commercial harvest of Palmaria palmata (Dulse) is presented based on a logistic model and field data collected on Digby Neck, Nova Scotia from 14 harvested shores during May to August, 2010. Field observations used to estimate model parameters included cover of Dulse before and after harvest from Dulse dominated boulders for which surface area was estimated, and from which fresh biomass of harvested Dulse was weighed. Over all the surveys the average harvest fraction was about 50%, and the total resource was about $1,600g\;m^{-2}$. With growth rates in excess of 4% per day and a 50% harvest of the standing crop each month, the model suggests that the Dulse resource is sustainable at current harvest levels.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.166-174
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• 2018

Potato(Solanum tuberosum L.) is one of the major food crop in the world following rice, wheat, and maize. It is thus important to project yield predict of potato under climate change conditions for assessment of food security. A crop growth modelling is widely used to simulate crop growth condition and total yield of various crops under a given climate condition. The decision support system for agrotechnology transfer (DSSAT) cropping system model, which was developed by U.S. which package integrating several models of 27 different crops, have been used to project crop yield for the impact assessment of climate change on crop production. In this study, we simulated potato yield using RCP 8.5 climate change scenario data, as inputs to the DSSAT model in five regions of Korea. The genetic coefficients of potato cultivar for 'superior', which is one of the most widely cultivated potato variety in Korea were determined. The GenCalc program, which is a submodule of the DSSAT package, was used to determine the genetic coefficients for the superior cultivar. The values of genetic coefficients were validated using results of 39 experiments performed over seven years in five regions. As a case study, the potato yield was projected that total yields of potato across five regions would increase by 26% in 2050s but decrease by 17% in 2090s, compared with 2010s. These results suggested that the needs for cultivation and irrigation technologies would be considerably large for planning and implementation of climate change adaptation for potato production in Korea.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.347-354
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• 2019

Temperature-dependent traits of Laodelphax striatellus, rice stripe virus vector, were investigated at 10 constant temperatures (12.5, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5, and 35.0 ± 1℃) under a fixed photoperiod (14/10-hr light/dark cycle). Unit functions for the oviposition model were estimated and implemented into a population dynamics model using DYMEX. The longevity of L. striatellus adults decreased with increasing temperature (56.0 days at 15.0℃ and 17.7 days at 35.0℃). The highest total fecundity (515.9 eggs/female) was observed at 22.5℃, while the lowest (18.6 eggs/female) was observed at 35.0℃. Adult developmental rates, temperature-dependent fecundity, age-specific mortality rates, and age-specific cumulative oviposition rates were estimated. All unit equations described adult performances of L. striatellus accurately (r² =0.94~0.97). After inoculating adults, the constructed model was tested under pot and field conditions using the rice-plant hopper system. The model output and observed data were similar up to 30 days after inoculation; however, there were large discrepancies between observed and estimated population density after 30 days, especially for 1^st and 2^nd instar nymph densities. Model estimates were one or two nymphal stages faster than was observed. Further refinement of the model created in this study could provide realistic forecasting of this important rice pest.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.144-153
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• 2017

In recent years, unmanned aerial vehicles (UAVs) have been developed and studied for various applications, including drone deliveries, broadcasting, scouting, crop dusting, and firefighting. To enable the wide use of UAVs, their exact aeroacoustic characteristics must be assessed. In this study, a noise prediction method for a ducted fan UAV with complicated geometry was developed. In general, calculation efficiency is increased by simulating a ducted fan UAV without the struts that fix the fuselage to the ducts. However, numerical predictions of noise and aerodynamics differ according to whether struts are present. In terms of aerodynamic performance, the total thrust with and without struts is similar owing to the tendency of the thrust of a blade to offset the drag of the struts. However, in aeroacoustic simulations, the strut effect should be considered in order to predict the UAV's noise because noise from the blades can be changed by the strut effect. Modelling of the strut effect revealed that the dominant tonal noises were closely correlated with the blade passage frequency of the experimental results. Based on the successful detection of noise sources from a ducted fan UAV system, using the proposed noise contribution contour, methods for noise reduction can be suggested by comparing numerical results with measured noise profiles.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.1
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• pp.67-74
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• 2008

Recently, construction of bridges in rural areas has been increased to preserve the natural environment. However this brings forth the disputes over rights of light in farmland. In urban areas, the disputes over rights of light have been settled on the authority of the national architectural law and only sunshine hours for winter solstice are considered. Basically, the point at issue is different between each case. The main issues of the dispute in rural area were the reduction of the crop cultivation and the increase of the heating cost in winter. The purpose of this study is to review the mediation process in national environmental dispute resolution commission to resolve these issues, and to set up the analysis method of rights of light and modelling equation of solar position. Furthermore, we aimed at analyzing the damaged hours of daylights in rural housing and the infringement rate of daylight in farmland through the case study. In conclusion, we estimated the sunshine hours during the whole damaged periods according to the elements of bridges, and presented the solution process of dispute over rights of light due to the construction of bridge in rural area.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.135-135
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• 2017

Greenhouse have been developed to provide the plants with good environmental conditions for cultivation crop, two major factors of which are the inside air temperature and humidity. The inside temperature are influenced by the heating systems, ventilators and for systems among others, which in turn are geverned by some type of controller. Likewise, humidity environment is the result of complex mass exchanges between the inside air and the several elements of the greenhouse and the outside boundaries. Most of the existing models are based on the energy balance method and heat balance equation for modelling the heat and mass fluxes and generating dynamic elements. However, greenhouse are classified as complex system, and need to make a sophisticated modeling. Furthermore, there is a difficulty in using classical control methods for complex process system due to the process are non linear and multi-output(MIMO) systems. In order to predict the time evolution of conditions in certain greenhouse as a function, we present here to use of recurrent neural networks(RNN) which has been used to implement the direct dynamics of the inside temperature and inside humidity of greenhouse. For the training, we used algorithm of a backpropagation Through Time (BPTT). Because the environmental parameters are shared by all time steps in the network, the gradient at each output depends not only on the calculations of the current time step, but also the previous time steps. The training data was emulated to 13 input variables during March 1 to 7, and the model was tested with database file of March 8. The RMSE of results of the temperature modeling was $0.976^{\circ}C$, and the RMSE of humidity simulation was 4.11%, which will be given to prove the performance of RNN in prediction of the greenhouse environment.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.47-57
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• 2013

This study is to assess the reduction of non-point source pollution loads for rice straw mulching of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed (1.21 $km^2$) located in the upstream of Gyeongan-cheon, the HSPF (Hydrological Simulation Program-Fortran) and SWAT (Soil and Water Assesment Tool), physically based distributed hydrological models were applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow using the HSPF was 0.62~0.76 and the determination coefficient ($R^2$) for water quality (sediment, total nitrogen T-N, and total phosphorus T-P) were 0.72, 0.62, and 0.63 respectively. The NSE for streamflow using the SWAT were 0.43~0.81 and the $R^2$ for water quality (sediment, T-N, and T-P) were 0.54, 0.87, and 0.64 respectively. From the field experiment of 16 rainfall events, the rice straw cover condition reduced surface runoff average 10.0 % compared to normal surface condition. By handling infiltration capacity (INFILT) in HSPF model, the value of 16.0 mm/hr was found to reduce about 10.0 % reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. By handling soil hydraulic conductivity (SOL_K) in SWAT model, the value of 111.2 mm/hr was found to reduce about 10.0 point reduction of surface runoff. For this condition, the reduction effect of sediment, T-N, and T-P loads were 80.0, 83.2, and 78.7 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as sediment and T-P.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.191-197
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• 2021

Ensuring the economic security of agro-industrial complexes of Ukrainian regions has become a top-priority task of state regional policy, as their stable functioning is an essential element of economic security of the whole country. It is overcoming threats to the development of the agro-industrial complex that ensures its further effective functioning and has a significant impact on the economic security of our state. Methods: logical method; methods of system analysis; synthesis; economic and statistical method; method of expert assessment; SWOT analysis; economic and mathematical modelling and planning. Results. Characteristic features of economic security have been given. The essence and significance of the agro-industrial complex in improving the economic security of the state have been determined. It has been noted that in recent years, the agro-industrial complex, which acts as a driver of the domestic economy and has a direct impact on the development of the country, has been growing (in 2019 the cereal and legume harvest exceeded 75 million tons, 20,269 thousand tons of potatoes were dug, more than 15 million tons of sunflower, 9,688 thousand tons of vegetables and 2,119 thousand tons of fruits and berries were harvested, meat and egg production increased by 137.5 thousand tons (or 5.8%) and 545.5 million pieces (or 3.4%), respectively, the number of employed population in agriculture increased by 139.8 thousand people (or 4.9%), the labour productivity in crop production increased by UAH 294.4 thousand (or 44.6%), in livestock production - by UAH 311.3 thousand (or 61.8%)). Based on the system of production and economic indicators, the analysis of the state of the agro-industrial complex has been carried out. Taking into account the results of the obtained data and using SWOT-analysis, the major threats to the development of the agro-industrial complex have been identified. Ways of overcoming threats enhancing the economic security of Ukraine have been proposed.