• International Journal of Computer Science & Network Security
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• v.24 no.7
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• pp.128-142
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• 2024

Creation and implementation of export-oriented strategy is an urgent issue of economic development of any country. In an export-oriented model of economic development, exports should be a means of promoting economic growth and a tool to strengthen existing and potential competitive advantages. Agricultural production is the key factor in exports and the source of foreign exchange earnings in many countries. However, the export potential of agricultural producers may be inefficiently fulfilled due to the heterogeneity of countries in terms of economic development, trade relations and border policy. The aim of the research is to study the nature, main trends and problematic aspects of fulfilling the export potential of agricultural production in the context of aggravating food crisis. The study involved general scientific methods (induction and deduction, description, analysis, synthesis, generalization) and special (statistical method, economic analysis, descriptive statistics and interstate comparisons, graphical method). The need to ensure food security by countries around the world urges the importance of the agricultural sector as a catalyst for economic development, sources of foreign exchange earnings, investment direction, etc. The study of agricultural specialization led to the conclusion that wheat and sugar are goods with the highest export potential. It is substantiated that the countries of South America, OECD, North America and Europe have the highest level of realization of export potential of agricultural production, and African countries are import-dependent. In addition, the low export orientation of Africa and Asia due to the peculiarities of their natural and climatic conditions is established based on the assessment of export-import operations in the regional context. The internal and external export potential of each of the regions is analysed. Economic and mathematical simulation of assessing the impact of the most important factors on the wheat exports volumes was applied, which allowed predicting wheat exports volume and making sound management decisions regarding the realization of the export potential of agricultural companies. The inverse correlation between the exports volume and wheat consumption per capita, and the direct correlation between the effective size and area of land used for wheat cultivation was established through the correlation and regression analysis.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.4
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• pp.1-11
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• 2024

Bridges crack and become damaged due to age and external factors such as earthquakes, lack of maintenance, and weather conditions. With the number of aging bridge on the rise, lack of maintenance can lead to a decrease in safety, resulting in structural defects and collapse. To prevent these problems and reduce maintenance costs, a system that can monitor the condition of bridge and respond quickly is needed. To this end, existing research has proposed artificial intelligence model that use sensor data to identify the location and extent of cracks. However, existing research does not use data from actual bridge to determine the performance of the model, but rather creates the shape of the bridge through simulation to acquire data and use it for training, which does not reflect the actual bridge environment. In this paper, we propose a bridge safety determination edge AI model that detects bridge abnormalities based on artificial intelligence by utilizing acceleration data from bridge occurring in the field. To this end, we newly defined filtering rules for extracting valid data from acceleration data and constructed a model to apply them. We also evaluated the performance of the proposed bridge safety determination edge AI model based on data collected in the field. The results showed that the F1-Score was up to 0.9565, confirming that it is possible to determine safety using data from real bridge, and that rules that generate similar data patterns to real impact data perform better.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.107-114
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• 2011

Purpose: To assess the degree and clinical impact of location error of the dens on the X-axis during radiotherapy to brain and head and neck tumors. Materials and Methods: Twenty-one patients with brain tumors or head and neck tumors who received three-dimensional conformal radiation therapy or intensity-modulated radiation therapy from January 2009 to June 2010 were included in this study. In comparison two-dimensional verification portal images with initial simulation images, location error of the nasal septum and the dens on the X-axis was measured. The effect of set-up errors of the dens was simulated in the planning system and analyzed with physical dose parameters. Results: A total of 402 portal images were reviewed. The mean location error at the nasal septum was 0.16 mm and at the dens was 0.33 mm (absolute value). Location errors of more than 3 mm were recorded in 43 cases (10.7%) at the nasal septum, compared to 133 cases (33.1%) at the dens. There was no case with a location error more than 5 mm at the nasal septum, compared to 11 cases (2.7%) at the dens. In a dosimetric simulation, a location error more than 5 mm at the dens could induce a reduction in the clinical target volume 1 coverage (V95: 100%${\rightarrow}$87.2%) and overdosing to a critical normal organ (Spinal cord V45: <0.1%${\rightarrow}$12.6%). Conclusion: In both brain and head and neck radiotherapy, a relatively larger set-up error was detected at the dens than the nasal septum when using an electronic portal imaging device. Consideration of the location error of the dens is necessary at the time of the precise radiation beam delivery in two-dimensional verification systems.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.13-29
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• 1998

Recently, It is increasing popularity to research on the soil remediation in aspect of management by reason of the hazardous impact on the contaminated soil in Korea. It was investigated high levels of arsenic salts in soil near abandoned five mines(Darak, Daduk, Jingok, Dalsung, Ilkwang) located in Youngnam area. Arsenic, classified as group A(Human Carcinogens) from IRIS, have shown statistically significant increment in skin cancer with oral exposure. This paper was conducted to predict excess cancer risk value (to the skin cancer) based on multiple pathway such as soil ingestion, dermal uptake and food(plant) ingestion contaminated by arsenic, and also, to identify the remedial goal regarded in future land use. The mine having the highest arsenic level was Daduk(mean : 1950mg/kg) and the next rank was Jingok(1690mg/kg), Ilkwang(352.37mg/kg), Dalsung(86.08mg/kg), Darak(0.83mg/kg). The chronic daily intake to the multiple exposure were calculated using Monte-Carlo simulation regarded in future land use and used q: value was $1.5(mg/kg/day)^{-1}$ to the oral proposed by IRIS(1997). The computated excess cancer risk 95th value to all the mine regarding future land use as residential and rural area were more than $10^{-4}$. If the level of acceptable risk is aimed for 1$\times$$10^{-6}$, it could be used Darak as commercial and industrial area without soil remediation due to the lowest risk value(6$\times$$10^{-8}$ and 3$\times$$10^{-8}$). Computated remedial goal based on 1$\times$$10^{-6}$ of acceptable risk to the future land use as the residential, rural, commercial and industrial area were 0.02mg/kg, 0.003mg/kg, 97.31mg/kg and 194.62mg/kg, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.192-203
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• 2011

The CERES-Barley crop simulation model was used to assess the impacts of climate change on the potential yield of winter naked barley in Korea. Fifty six sites over the southern part of the Korean Peninsula were selected to compare the climate change impacts in various climatic conditions. Based on the A1B climate change scenarios of Korea, the present climatological normal (1971-2000) and the three future ones (2011-2040, 2041-2070, and 2071-2100) were considered in this study. The three future normals were divided by three environmental conditions with changes in: (1) temperature only, (2) carbon dioxide concentration only, and (3) both temperature and carbon dioxide concentration. The agreement between the observed and simulated outcomes was reasonable with the coefficient of determination of grain yield to be 0.78. We concluded that the CERES-Barley model was suitable for predicting climate change impacts on the potential yield of winter naked barley. The effect of the increased temperature only with the climate change scenario was negative to the potential yield of winter naked barley, which ranges from -34 to -9% for the three future normals. However, the effect of the elevated carbon dioxide concentration only on the potential yield of winter naked barley was positive, ranging from 6 to 31% for the three future normals. For the elevated conditions of both temperature and carbon dioxide concentration, the potential yields increased by 8, 15, and 13% for the 2011-2040, 2041-2070, and 2071-2100 normals, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.142-154
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• 2011

This study predicted the probability of corrosion initiation of reinforced concrete tunnel boxes structures using the Monte Carlo Simulation. For the inner wall and outer wall in the tunnel boxes, exposed to airborne chloride ion and seawater directly respectively, statistical values of parameters like diffusion coefficient D, surface chloride content $C_s$, cover depth c, and the chloride threshold level $C_{lim}$ were examined from experiment or literature review. Their average values accounted for $3.77{\times}10^{-12}m^2/s$, 3.0% by weight of cement, 94.7mm and 45.5mm for outer wall and inner wall, respectively, and 0.69% by weight of cement for D, $C_s$, c, and $C_{lim}$, respectively. With these parametric values, the distribution of chloride contents at rebar with time and the probability of corrosion initiation of the tunnel boxes, inner wall and outer wall, was examined by considering time dependency of chloride transport. From the examination, the histogram of chloride contents at rebar is closer to a gamma distribution, and the mean value increases with time, while the coefficient of variance decreases with time. It was found that the probability of corrosion initiation and the time to corrosion were dependent on the time dependency of chloride transport. Time independent model predicted time to corrosion initiation of inner wall and outer wall as 8 and 12 years, respectively, while 178 and 283 years of time to corrosion was calculated by time dependent model for inner wall and outer wall, respectively. For time independent model, the probability of corrosion at 100 years of exposure for inner wall and outer wall was ranged 59.5 and 95.5%, respectively, while time dependent model indicated 2.9 and 0.2% of the probability corrosion, respectively. Finally, impact of $C_{lim}$, including values specified in current codes, on the probability of corrosion initiation and corrosion free life is discussed.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.779-797
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• 2016

A calibrated hydrological model is a useful tool for quantifying the impacts of the climate variations and land use/land cover changes on sediment load, water quality and runoff. In the rainy season each year, the Xe Bang Fai river basin is provisionally flooded because of typhoons, the frequency and intensity of which are sensitive to ongoing climate change. Severe heavy rainfall has continuously occurred in this basin area, often causing severe floods at downstream of the Xe Bang Fai river basin. The main purpose of this study is to investigate the climate change impact on river discharge using a Soil and Water Assessment Tool (SWAT) model based on future climate change scenarios. In this study, the simulation of hydrological river discharge is used by SWAT model, covering a total area of $10,064km^2$ in the central part of country. The hydrological model (baseline) is calibrated and validated for two periods: 2001-2005 and 2006-2010, respectively. The monthly simulation outcomes during the calibration and validation model are good results with $R^2$ > 0.9 and ENS > 0.9. Because of ongoing climate change, three climate models (IPSL CM5A-MR 2030, GISS E2-R-CC 2030 and GFDL CM3 2030) indicate that the rainfall in this area is likely to increase up to 10% during the summer monsoon season in the near future, year 2030. As a result of these precipitation increases, the SWAT model predicts rainy season (Jul-Aug-Sep) river discharge at the Xebangfai@bridge station will be about $800m^3/s$ larger than the present. This calibrated model is expected to contribute for preventing flood disaster risk and sustainable development of Laos

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Proceedings of the KOR-KST Conference
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• 1995.12a
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• pp.45-73
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• 1995

The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.437-446
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• 2022

In April 2020, the Korean government decided to operate the Hwacheon reservoir, a hydropower reservoir to supply water, and it is currently under pilot operation. Through the pilot operation, the Hwacheon reservoir is the first among the hydropower reservoirs in Korea to make a constant release for downstream water supply. In this study, the water supply capacity of the Hwacheon reservoir was estimated using the inflow data of the Hwacheon reservoir. A simulation model was developed to calculate the water supply that satisfies both the monthly water supply reliability of 95% and the annual water supply reliability of 95%. An optimization model was also developed to evaluate the water supply capacity of the Hwacheon reservoir. The inflow data used as input data for the model was modified in two ways in consideration of the impact of the Imnam reservoir. Calculating the water supply for the Hwacheon reservoir using the two modified inflows is as follows. The water supply that satisfies 95% of the monthly water supply reliability is 26.9 m³/sec and 24.1 m³/sec. And the water supply that satisfies 95% of the annual water supply reliability is 23.9 m³/sec and 22.2 m³/sec. Hwacheon reservoir has a maximum annual water supply of 777 MCM (Million Cubic Meter) without failure in the water supply. The Hwacheon reservoir can supply 704 MCM of water per year, considering the past monthly power generation and discharge patterns. If the Hwacheon reservoir performs a routine operation utilizing its water supply capacity, it can contribute to stabilizing the water supply during dry seasons in the Han River Basin.