• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.159-159
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• 2022

Soil represents a substantial component within the global carbon cycle and small changes in the SOC stock may result in large changes of atmospheric CO₂ particularly over tens to hundreds of years. In this study, we aim to (i) evaluate the SOC stock in the topsoil 0 - 15 cm from soil physical and chemical characteristics and (ii) find the correlation of SOC and soil organic matter (SOM) for national-scale in South Korea. First of all, based on the characteristics of the soil to calculate the soil hydraulic properties, SOC stock is the SOC mass per unit area for a given depth. It depends on bulk density (BD-g/cm³), SOC content (%), the depth of topsoil (cm), and gravel content (%). Due to insufficient data on BD observation, we establish a correlation between BD and SOC content, sand content, clay content parameter. Next, we present linear and non-linear regression models of BD and the interrelationship between SOC and SOM using a linear regression model and determine the conversion factor for them, comparing with Van Bemmelen 1890's factor value for the country scale. The results obtained, helps managers come up with suitable solutions to conserve land resources.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.167-167
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• 2023

Soil organic carbon (SOC) is a critical component of soil health and is crucial in mitigating climate change by sequestering carbon from the atmosphere. Accurate estimation of SOC storage is essential for understanding SOC dynamics and developing effective soil management strategies. This study aimed to investigate the factors influencing the spatial distribution of SOC storage in South Korea, using bulk density (BD) prediction to estimate SOC stock. The study utilized data from 393 soil series collected from various land uses across South Korea established by Korea Rural Development Administration from 1968-1999. The samples were analyzed for soil properties such as soil texture, pH, and BD, and SOC stock was estimated using a predictive model based on BD. The average SOC stock in South Korea at 30 cm topsoil was 49.1 Mg/ha. The study results revealed that soil texture and land use were the most significant factors influencing the spatial distribution of SOC storage in South Korea. Forested areas had significantly higher SOC storage than other land use types. Climate variables such as temperature and precipitation had a relative influence on SOC storage. The findings of this study provide valuable insights into the factors influencing the spatial distribution of SOC storage in South Korea.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.38-43
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• 2008

The purpose of this study is to secure reasonable transportation infrastructure stock for enhancing national competitiveness in Korea. National competitiveness may be defined as a country's overall capacity to create the most effective social structure, institutions and policies that allow her company within the national boundary to be more competitive in the world market. If Korea's transportation infrastructure stock is not sufficient and a connection among transportation facilities is not efficient, we should pay the social and economic cost. As a result, we worry that national competitiveness may drop. Some methods to maintain or to increase the national investment for transportation infrastructure that are suggested from this study are as follows: Firstly, we need to operate the Spcial Account for Traffic Facilities. Secondly, the investment should be focused on the facilities and districts in needs. Thirdly, PFI (private finance initiative) policy should be aimed at investing for the highly economic-valued projects.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.205-212
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• 2014

Chronological changes of soil organic carbon (SOC) must be prepared by IPCC guidelines for national greenhouse gas inventories. IPCC suggested default reference SOC stocks for mineral soils and relative stock factors for different management activities where country own factors were not prepared. 3.4 million data were downloaded from agricultural soil information system and analyzed to get chronological changes of SOC for some counties and for land use in Korea. SOC content of orchard soil was higher than the other soils but chronological SOC changes of all land use had no tendency in differences with high standard deviation. SOC contents of counties depended on their own management activities and chronological SOC changes of districts also had no tendency in differences. Thus, Korea should survey the official records and relative stock factors on management activities such as land use, tillage and input of organic matter to calculate SOC stocks correctly. Otherwise, Korea should establish a model for predicting SOC by analyzing selected representative fields and by calculating SOC differences from comparing management activities of lands with those of representative fields.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.90-96
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• 2023

The aim of this study was to investigate the effect of application rate of rice straw compost on soil chemical properties and soil organic carbon stock (SOC stock). The experiments were performed with no fertilizer (NF), inorganic fertilizer (NPK), NPK + rice straw compost 7.5 ton ha^-1 (NPKC7.5), NPK + rice straw compost 15 ton ha^-1 (NPKC15), NPK + rice straw compost 22.5 ton ha^-1 (NPKC22.5), and NPK + rice straw compost 30 ton ha^-1 (NPKC30). The SOC and SOC stock were highest in the NPKC30 treatment at 22.8 g kg^-1 and 71.2 Mg C ha^-1, respectively. Rice production was in the range of 621.2-654.4 kg 10a^-1 in NPKC22.5 and NPKC30 treatments, which was higher than that in the NPK treatment. However, with increase in compost application, the exchangeable K and Ca of the soil increased, and the exchangeable K and Ca were higher than the optimum range in NPKC22.5 and NPKC30 treatments. Excessive application of compost can have negative impacts on the environment, including nutrient accumulation in the soil and water pollution from nutrient runoff. Therefore, applying the standard amount of compost according to the agricultural environment would be appropriate, despite the relatively lower rice production and SOC stock than that observed with the application of 22.5 and 30 ton ha^-1.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.83-92
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• 2005

We try to evaluate the stock level of Korean transportation infrastructure comparing Korean SOC stock level with those of OECD countries. In order to do so, we work on indices to show the transportation infrastructure stock levels of various countries. Among several indices, we select the effective road-extension rate per population density and the effective railroad-extension rate per population density corresponding to road and railroad. We compare Korean road and railroad stock levels with those of OECD countries, to make use of the effective road-extension rate per population density and effective railroad-extension rate per population density. We choose the Britain, Greece, Portugal, and Sweden to compare Korea because their sizes of population and territory are similar to those of Korea. Using International comparison, we arrive at the conclusion that Korean road and railroad stock levels are 63.4% and 53.2% of those of four countries respectively. In addition, we estimate the target level of road and railroad stocks and compute the target level of investments in road and railroad based on the result.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.153-158
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• 2018

At the Bank of Korea, capital stock statistics were created by the PIM (perpetual inventory method) with fixed capital formation data. Asset classifications also included 2 categories in residential buildings, 4 non-residential buildings, 14 constructions, 9 transportation equipment, 28 machinery, and 2 intangible fixed assets. It is the Korean government accounting system which is developed much with the field of the national accounts including the valuation, but until 2008 it was consistent with single-entry bookkeeping. Many countries, including Korea, were single-entry bookkeeping, not double-entry bookkeeping which can be aggregated by government accounting standard account. There was no distinction in journaling between revenue and capital expenditure when it was consistent with single-entry bookkeeping. For example, we would like to appropriately divide the past budget accounts and the settlement accounts data that have been spent on dredging into capital expenditure and revenue expenditure. It, then, tries to add the capital expenditure calculated to FCF (fixed capital formation), because revenue expenditure is cost for maintenance etc. This could be a new direction, especially, in the estimation of capital stock by the perpetual inventory method for infrastructure (SOC, social overhead capital). It should also be noted that there are differences not only between capital and income expenditure but also by other factors. How long will this difference be covered by the difference between the 'new series' and 'old series' methodologies? In addition, there is no large difference between two series by the major asset classification level. If this is treated as a round-off error, this is a problem.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.233-239
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• 2021

The objective of this study is to find out the factors affecting the employees' loyalty in private joint-stock commercial banks in Mekong Delta, Vietnam. Then, possible solutions can be proposed, which can be implemented to improve employees' engagement in private joint-stock commercial banks in Mekong Delta, Vietnam, in the future. The author conducted a survey of 300 employees at 6 private joint-stock commercial banks in 6 provinces in Mekong Delta: An Giang, Tra Vinh, Can Tho, Ben Tre, Soc Trang, and Tien Giang. The author also used the Cronbach Alpha reliability analysis method, exploratory factor analysis (EFA), and multivariate regression analysis. The results show the degree of influence of factors on employees' loyalty - according to decreasing importance: Income, Job characteristics, Working environment, Colleagues, Leadership. The authors propose some solutions based on the research findings, including focusing on assigning the right employees to the right jobs, creating a competitive and fair working environment, focusing on a reasonable income policy, and transparency in working relationships to help bank managers in the Mekong Delta, Vietnam improve human resource management to improve employee loyalty to private joint-stock commercial banks in Vietnam.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.43-60
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• 2019

Background: Tropical montane forests played an important role in the provision of ecosystem services. The intense degradation and deforestation for the need of agricultural land expansion result in a significant decline of forest cover. However, the expansion of agricultural land did not completely destruct natural forests. There remain forests inaccessible for agricultural and grazing purpose. Studies on these forests remained scant, motivating to investigate biomass and soil carbon stocks. Data of biomass and soils were collected in 80 quadrats ($400m^2$) systematically in 5 forests. Biomass and disturbance gradients were determined using allometric equation and disturbance index, respectively. The regression modeling is employed to explore the spatial distribution of carbon stock along disturbance and environmental gradients. Correlation analysis is also employed to identify the relation between site factors and carbon stocks. Results: The result revealed that a total of 1655 individuals with a diameter of ${\geq}5cm$, representing 38 species, were measured in 5 forests. The mean aboveground biomass carbon stocks (AGB CS) and soil organic carbon (SOC) stocks at 5 forests were $191.6{\pm}19.7$ and $149.32{\pm}6.8Mg\;C\;ha^{-1}$, respectively. The AGB CS exhibited significant (P < 0.05) positive correlation with SOC and total nitrogen (TN) stocks, reflecting that biomass seems to be a general predictor of SOCs. AGB CS between highly and least-disturbed forests was significantly different (P < 0.05). This disturbance level equates to a decrease in AGB CS of 36.8% in the highly disturbed compared with the least-disturbed forest. In all forests, dominant species sequestrated more than 58% of carbon. The AGB CS in response to elevation and disturbance index and SOC stocks in response to soil pH attained unimodal pattern. The stand structures, such as canopy cover and basal area, had significant positive relation with AGB CS. Conclusions: Study results confirmed that carbon stocks of studied forests were comparable to carbon stocks of protected forests. The biotic, edaphic, topographic, and disturbance factors played a significant variation in carbon stocks of forests. Further study should be conducted to quantify carbon stocks of herbaceous, litter, and soil microbes to account the role of the whole forest ecosystem.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.8
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• pp.851-860
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• 2015

Transport Social Overhead Capital refers to public utilities necessary for a nation's basic economic activities, and is divided into roads, railway, subway, ports and so on. It is important to be able to provide these SOC in the right place at the right time to enhance productivity and competitiveness of a nation. In this study, correlation and factor analysis on countries' socioeconomic and transport indicators were performed in order to understand the need for expansion of SOCs including railway, and to identify the impact they have on national competitiveness(productivity). As a result, GDP showed high correlativity(0.59~0.99) with factors such as population, land area, extension of available railroad, and road extension. Specifically, through the analysis of Russia's urban transport system and comparison between socioeconomic indices and SOCs of OECD countries, it was examined that how increasing transport infrastructure investments could enhance national competitiveness. In conclusion, opening new Light Rail greatly affects the growth of GDP followed by the increasing extension of available railroad. Furthermore, if available railroad extension is increased by 10 % from 2014, assuming high speed tram is opened, GDP will likely increase by 21.6%.