• Journal of Hydrogen and New Energy
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• v.34 no.2
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• pp.91-99
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• 2023

Participation in power trading using surplus power is considered a business model active in the domestic energy trade market, but it is limited only if the legal requirements according to the type, capacity, and use of the facilities to be applied for are satisfied. The hydrogen residential demonstration model presented in this paper includes solar power, energy storage system (ESS), fuel cell, and water electrolysis facilities in electrical facilities for private use with low-voltage power receiving system. The concept of operations strategy for this model focuses on securing the energy self-sufficiency ratio of the entire system, securing economic feasibility through the optimal operation module installed in the energy management system (EMS), and securing the stability of the internal power balancing issue during the stand-alone mode. An electric facility configuration method of a hydrogen residential complex demonstrated to achieve this operational goal has a structure in which individual energy sources are electrically connected to the main bus, and ESS is also directly connected to the main bus instead of a renewable connection type to perform charging/discharging operation for energy balancing management in the complex. If surplus power exists after scheduling, participation in power trading through reverse transmission parallel operation can be considered to solve the energy balancing problem and ensure profitability. Consequentially, this paper reviews the legal regulations on participation in electric power trading using surplus power from hydrogen residential models that can produce and consume power, gas, and thermal energy including hybrid distributed power sources, and suggests action plans.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• New & Renewable Energy
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• v.19 no.4
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• pp.2-10
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• 2023

The current mandatory domestic biodiesel blending ratio is 3.5%, which is planned to be gradually increased to achieve carbon neutrality by 2050. The aim of this study was to improve domestic self-sufficiency in biodiesel raw oil by conducting a technical review on the possibility of utilizing waste oils, such as soup oil, chicken oil, and leather oil, as biodiesel feedstocks. These waste oils have an acid value that is too high to be converted directly into biodiesel. Therefore, a pretreatment to reduce the acid value is necessary. The neutralization process was examined as a potential technology for reducing the acid value. The oil recovery rate of the soup oil after neutralization was significantly low at 37.6 wt%. The oil recovery rates of leather oil and chicken oil were 66.49 wt% and 79.08 wt%, respectively. Based on biodiesel conversion experiment using waste oil with a reduced acid value, the conversions were analyzed as 89 wt%, 91.1 wt%, and 90.5 wt% for soup oil, leather oil, and chicken oil, respectively. Thus, it is technically possible to use soup oil, leather oil, and chicken oil as raw materials for producing biodiesel.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.241-249
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• 2024

Using the panel data of 31 regions in China from 2006 to 2021, this paper analyzes the efficiency and influencing factors of the fiscal expenditure on compulsory education in China. Through the analysis found that the efficiency of some economically developed regional is lower, but the efficiency of economically backward regional is higher. In order to further analyze the influencing factors of the efficiency of fiscal expenditures on compulsory education, using Tobit model is analyzed. It is found that regional per capita GDP and fiscal self-sufficiency rate have a negative impact on the efficiency of fiscal expenditure on compulsory education. Age structure, percentage of fiscal expenditure on compulsory education and level of teachers have a positive impact on the efficiency of fiscal expenditure on compulsory education. Fiscal decentralization has no significant effect on the efficiency of fiscal expenditure on compulsory education.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.1-10
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• 2024

In this study, we constructed a process simulation model for an agricultural by-products based Solid Oxide Fuel Cell (SOFC) combined heat and power generation system as part of the introduction of technology for energy self-sufficiency in the agricultural sector. The aim was to reduce the burden of increasing fuel and electricity consumption due to rapid fluctuations in international oil prices and the expansion of smart farming in domestic farms, while contributing to the national greenhouse gas reduction goals. Based on the experimental results of 0.3 ton/day torrefied agricultural by-product gasification experiment, a model for an agricultural by-product-based SOFC cogeneration system was constructed, and optimization of the heat exchange network was conducted for SOFC capacities ranging from 4 to 20 kW. The results indicated that an 8 kW agricultural by-product-based SOFC cogeneration system was optimal under the current system conditions. It is anticipated that these research findings can serve as foundational data for future commercial facility design.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.179-184
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• 2024

Corn is essential for both humans and animals. The crop is the third most important food crop after rice and wheat. A rise in farming is resulting in a lack of self-sufficiency of high quality forages. Therefore, corn cultivars in Korea must be optimized to increase productivity and yield. A study was conducted in Pyeongchang, South Korea between 2021-2022 to evaluate the characteristics and productivity of three corn cultivars: Kwangpyeongok, AGR 41, and Nero IT. Different varieties of corn were sown in Pyeongchang on April 29 and April 27 of 2021 and 2022, respectively. The productivity and characteristics of the cultivars Kwangpyeongok, AGR 41, and Nero IT were evaluated during the yellowing ripening stage. The characteristics included the leaves, stems, grain, and stover content. Across different corn cultivars, there was no significant difference in stem height, diameter, forage or grain quantity based on an average of two years. Yet, significant differences were noted in the stem heights of all cultivars between 2021 and 2022 (p<0.05). There was a significant difference in the diameters of Kwangpyeongok and Nero IT between 2021 and 2022. A significant difference in forage yield was observed for Nero IT between 2021 and 2022. The yield of grains and forages was higher in 2021 than in 2022, which could be attributed to temperature and precipitation variations. We can conclude from these data that all cultivars in Pyeongchang showed significant productivity and yield, which could be useful to produce nutrient rich silage for livestock.

• Journal of the Korean Regional Science Association
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• v.35 no.3
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• pp.45-58
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• 2019

The government is recently pushing for five large-scale public housing sites near Seoul, the so-called third wave of new towns. In this regard, this study sought to analyze the key considerations in planning new towns from the perspective of the residents who are the consumers, using survey data. For this purpose, frequency analysis and variance analysis(ANOVA) were conducted on existing first and second era of new towns and the third era of new towns scheduled for construction. Eight indicators, such as environmental comfort, self-sufficiency such as jobs, transportation access and convenience, were set as subordinate variables, and characteristics of residents, including gender, age, number of households, household income, occupation, and residential areas, were set as explanatory variables. According to the analysis, the respondents rated the first era of new towns more positively than the second era of new towns. For self-sufficiency items such as jobs, both the first and second era of new towns showed low levels. In addition, for the eight indicators, the first era of new towns were no significant differences depending on gender, number of households, or household income, and the second era of new towns were no significant differences by the number of households, household income, occupations or place of residence. However, for new towns in the third period, the assessment of the importance of each indicator by age, number of households, household income and occupation showed significant differences. The results of the multi-comparison analysis of the third era of new towns showed that the importance of environmental comfort was highly valued by the youth, the managerial/professional/clerical position, single or five more persons of household, and the youth, high income household, the managerial/professional/clerical position when it comes to accessibility and convenience of transportation. It suggests that various personal characteristics and demands for each of the planning indicators need to be considered in planning for the third era of new towns.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.1
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• pp.2-15
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• 1982

In this report, a total domestic demand for major commercial fertilizer for crop production in Korea up to 1996 was estimated. The agricultural products and area for demand for both 1982 and 1986 was quoted from the estimate of the 5th Five-year Economic plan. And the demands estimated for 1991 and 1996 reflected possible changes of diet from cereal to meat and their indirect effects on the increase of cereal consumption. As the advanced countries followed, consequently, the demands for soybean, corn and other feed grains were expected to be increased as well as the land for growing those crops. 1. Total annual demands for nitrogen, phosphorus and potassium fertilizers were estimated 1,050,000M/T, 1,110,000M/T, 1,280,000M/T and 1,010,000M/T for the year 1982, 1986, 1991, and 1996 respectively. 2. It was assumed that there would be difficulties in self-sufficiency of grains at the cost of the maximum utilization of land and fertilizers in 1996. 3. It was clear that the increase of the productivity per unit area is possible by improving the conditions of arable land which could resulted a self-sufficiency of food in Korea. As a consequence, the demand for fertilizers at that time would exceed the level of estimates. 4. The recent decrease in demand for commercial fertilizers (currently estimated 850,000M/T) was due to an inadequate application of fertilizers for respective crop reqirement. This inadequacy should be checked and encouraged the consumptions of fertilizers to be increased by supporting the price of grain.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.94-106
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• 2022

In order to increase timber self-sufficiency, Korea's 6th Basic Forest Plan aims to increase the density of forest roads to 12.8 m ha^-1 by 2037. However, due to rapid re-forestation, current management infrastructure is insufficient, with just 4.8 m ha^-1 of forest roads in 2017. This is partly due to time and cost limitations on the process of forest road feasibility evaluation, which considers factors such as topography and forest conditions. To solve this problem, we propose an eco-friendly and efficient forest road network planning method using a geographic information system (GIS), which can evaluate a potential road site remotely based on spatial information. To facilitate such planning, this study identifies forest road construction priorities that can be evaluated using spatial information, such as topography, forest type and forest disasters. A method of predicting the optimal route to connect a forest road with existing roads is also derived. Overlapping analysis was performed using GIS-MCE (which combines GIS with multi-criteria evaluation), targeting the areas of Cheongsong-gun and Buk-gu, Pohang-si, which have a low forest-road density. Each factor affecting the suitability of a proposed new forest road site was assigned a cost, creating a cost surface that facilitates prioritization for each forest type. The forest path's optimal route was then derived using least-cost path analysis. The results of this process were 30 forestry site recommendations in Cheongsong-gun and one in Buk-gu, Pohang-si; this would increase forest road density for the managed forest sites in Cheongsong-gun from 1.58 m ha^-1 to 2.55 m ha^-1. This evaluation method can contribute to the policy of increasing timber self-sufficiency by providing clear guidelines for selecting forest road construction sites and predicting optimal connections to the existing road network.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.475-484
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• 2011

International price of cereal has been dramatically increasing for the past few years. This price hike amplified the importance of food self-sufficiency in numerous countries due to the fact that food security is directly proportional to food self-sufficiency. In this study, we conducted a survey to provide useful information of Cambodia's agricultural environment to possible Korean agricultural investors and as to highlight Cambodia as a strong candidate for the establishment of Korea's foreign base for cereal production. The survey conducted includes information regarding Cambodia's agricultural environment and investment circumstances including the political, economical and other contributing factors affecting agricultural investment in Cambodia. Seventy percent of the Cambodia's total population engage in agriculture and this comprises about 30% of the country's GDP. This statistics reflects the possibility of Cambodia's poverty alleviation which proves that agriculture in Cambodia is the driving force for the improvement of the country's economy. In addition, low labor cost, fertile land, abundant water resources, like the Tonle sap lake and the Mekong river, and unreclaimed lands are the strong points that could attract agricultural investors to Cambodia. Poor infrastructure, irrigation systems, law reforms, including social and cultural differences may be the biggest setbacks for the acceleration of Cambodia's agriculture development. However, the Cambodian government is open and willing to make adjustments for Cambodia to be both foreign and domestic agricultural investor-friendly, expecting that it will boost its country's agricultural development. Making the best out of this opportunity, the coordination of KOICA with Korean agricultural investors in building infrastructures and with the help of the KOPIA program for the transfer of agricultural technology will benefit both countries and will play an important role in Cambodia's agriculture.