• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.73-84
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• 2020

In this study, we compared and analyzed the static and dynamic analysis method for agricultural reservoirs. In addition, we assumed the aging of reservoir as the deterioration of the internal friction angle and cohesion. The internal friction angle and cohesion were applied by dividing into 4 case for each reservoir. As a result of comparing the stability of the reservoir embankment, it was found that the dynamic stability analysis method showed a greater risk than the static stability analysis method when dynamic loads such as earthquakes were applied. Therefore, when detailed review such as liquefaction is required, it is considered that the dynamic stability analysis method should be applied first. If a study on the change in material properties due to the aging of the reservoir is conducted, the stability analysis of the reservoir due to the aging of the reservoir can be performed more accurately. In addition, if a study comparing the results of dynamic stability analysis and static stability analysis for earthquakes with various characteristics for more reservoirs is conducted, detailed criteria for the case where dynamic stability analysis should be considered can be presented.

• Current Research on Agriculture and Life Sciences
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• v.27
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• pp.59-67
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• 2009

The purpose of this study is to propose the methodology for introducing green infrastructure that can improve the health of citizens by promoting walkability. The methodology is composed of the following three phases: classification of the types of green spaces, selection of core green spaces with two separate analyses, and introduction of the framework of green infrastructure to promote walkability. In the first phase, the classification of the types of green spaces was carried out in order to understand existing distribution pattern of green spaces in study site. In the second phase, walkable blocks were selected by such methods as walkability value. Through these two analyses, all the blocks were divided into three groups according to the ranking figured up the second analyses' results. The blocks in the first group, the group involved in the top 30% and having the greatest ranking, were defined as walkable blocks. In the last phase, a basic frame of the green infrastructure in study site was introduced by connecting the walkable blocks with using other blocks and the green spaces over 1ha. In case study, 28 important green spaces and 35 walkable blocks were selected through the two analysis process. Then, the basic framework of green infrastructure based on the selected 28 important green spaces and 35 walkable blocks was introduced. The methodology applied to this study can be used to get the best selections of the proper green infrastructure in accordance with the purpose of the ecological and recreational local development. In particular, this study will suggest a specific analysis model to use for the ecological and walkable urban planning with green spaces existing in the city.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.123-133
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• 2024

Existing autonomous driving technology has been developed based on sensors attached to the vehicles to detect the environment and formulate driving plans. On the other hand, it has limitations, such as performance degradation in specific situations like adverse weather conditions, backlighting, and obstruction-induced occlusion. To address these issues, cooperative autonomous driving technology, which extends the perception range of autonomous vehicles through the support of road infrastructure, has attracted attention. Nevertheless, the real-time analysis of the 3D centroids of objects, as required by international standards, is challenging using single-lens cameras. This paper proposes an approach to detect objects and estimate the centroid of vehicles using the fixed field of view of road infrastructure and pre-measured geometric information in real-time. The proposed method has been confirmed to effectively estimate the center point of objects using GPS positioning equipment, and it is expected to contribute to the proliferation and adoption of cooperative autonomous driving infrastructure technology, applicable to both vehicles and road infrastructure.

• Asian Journal of Business Environment
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• v.11 no.1
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• pp.17-25
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• 2021

Purpose: This study extends previous empirical work on the threshold effects of institutions on the relationship between infrastructure and economic growth. It does so by using three sub-indices of institutions as the threshold variable in place of aggregate index. This is with a view to determining the roles of the sub-indices in the nexus between infrastructure and economic growth. Research design, data and methodology: The analysis is based on a dynamic panel threshold regression model using a panel data set comprising 41 countries in Sub-Saharan Africa over the sample period of 1996-2015. Data are obtained from Ogbaro (2019). Results: The study finds that infrastructure exerts significant positive effects on economic growth below and above the threshold values of the three sub-indices, with higher effects above the threshold values. Results also show that on average, the Sub-Saharan African countries are not able to satisfy any of the threshold conditions, which accounts for their poor growth experience. Conclusion: The study concludes that countries with weak institutions do not benefit maximally from infrastructure development policies. The paper, therefore, recommends that countries in Sub-Saharan Africa need to focus on improving their institutional patterns if they are to reap the optimum benefits from their infrastructure development efforts.

• The Journal of Information Technology
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• v.6 no.4
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• pp.135-146
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• 2003

In the era of so-called knowledge-based economy, the creation and utilization of IT and new knowledge are recognized as core factors to enforce IT industry and to increase national competitiveness. Advanced countries, therefore, have heavily invested their resources on IT sector and introduced competition into the telecommunication market. ASEAN countries are trying to make themselves informationized society through IT market liberalization and industry development. They are investing lots of resources to construct IT infrastructure such as wired and wireless network and consider informationized society promotion as top national agenda. In this effort, Korea is a benchmarking model for them. Successful entering into ASEAN market requires close analysis and correct understanding of its IT policy and infrastructure. In this paper, therefore, tried to analyse IT policy and infrastructure of three ASEAN countries, which have high potential of economic cooperation in IT with Korea. And based on the analysis, tried to find out ways to enter into ASEAN.

• Journal of Auto-vehicle Safety Association
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• v.16 no.2
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• pp.27-33
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• 2024

In this study, an analysis was conducted on internal and external factors related to fires in electric vehicles in order to improve the safety of electric vehicles against fire accidents. To conduct the analysis, field survey data conducted on actual electric vehicle fire accidents were used, and accident-related statistical data was used. Among them, as a result of analyzing the internal factors related to fire accidents in electric vehicles, it was confirmed that high-voltage batteries are an important factor in fire accidents caused by internal factors of electric vehicles. An analysis of external factors for fire accidents of electric vehicles was also conducted in this study. The largest number of electric vehicle accidents that occurred on public roads were mainly caused by physical external forces such as collisions. Therefore, strengthening the safety of this road infrastructure could be an additional solution to improve the fire safety of electric vehicles. As a result, based on car accident cases, two crash scenarios based on road infrastructure were derived, each of which simulates a high-speed frontal collision situation and a lower-end collision situation. Additionally, detailed test methods for these scenarios were developed.

• Particle and aerosol research
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• v.19 no.4
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• pp.111-128
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• 2023

Chungcheongnam-do has various emission sources, including large-scale facilities such as power plants, steel and petrochemical industry complexes, which can lead to the severe PM pollution. Here, we measured concentrations of PM₁₀, PM_2.5, and its metallic elements at a suburban site in Taean, Chungcheongnam-do from September 2017 to June 2022. During the measurement period, the average concentrations of PM₁₀ and PM_2.5 were 58.6 ㎍/m³ (9.6~379.0 ㎍/m³) and 35.0 ㎍/m³ (6.1~132.2 ㎍/m³), respectively. The concentration of PM₁₀ and PM_2.5 showed typical seasonal variation, with higher concentration in winter and lower concentration in summer. When high concentrations of PM_2.5 occurred, particulary in winter, the fraction of Zn and Pb components considerably increased, indicating a significant contribution of Zn and Pb to high-PM_2.5 concentration. In addition, Zn and Pb exhibited the highest correlation coefficient among all other metallic elements of PM_2.5. A backward trajectory cluster analysis and CPF model were performed to examine the origin of PM_2.5. The high concentration of PM_2.5 was primarily influenced by emissions from industrial complexes located in the northeast and northwest areas.

• Journal of Internet Computing and Services
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• v.20 no.2
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• pp.51-59
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• 2019

In this paper, we analyzed the relationship between charging operation system and electricity charges connected with charging infrastructure among data of many demonstration projects focused on electric vehicles recently. At this point in time, due to the rapid increase in demand for the electric charging infrastructure that will take place in the future, we can prepare for an upcoming era in the sense of forecasting the demand value. At the same time, demonstrating and modeling optimized system modeling centering on sites is a prerequisite. The modeling based on the existing small - scale simulation and the design of the operating system are based on the data linkage analysis. In this paper, we implemented a new optimized system modeling and introduced it as a standard format to analyze time - dependent time - divisional data for each vehicle and user in each point and node. In order to verify the efficiency of the optimization based on the data linkage analysis for the actual implemented electric car charging infrastructure and operation system.

• The Journal of Information Systems
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• v.18 no.3
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• pp.183-210
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• 2009

This study investigated the degrees of knowledge management processes according to the levels of social capital(i.e., inter-departmental communication, trust, cooperation and integration) as well as information technology(IT) infrastructure(i.e., knowledge storage and transfer IT, and knowledge search IT) in Korean manufacturing firms. We also demonstrated the differences in organizational performance under various degrees of knowledge management processes. Through cluster analysis with social capital variables, we classified sample firms into five groups; 'the highest firms', 'higher firms', 'middle firms', 'lower firms', and 'the lowest firms'. It was also observed that the degrees of knowledge management processes and organizational performance in 'the highest firms' is the highest. With a structural equation modeling technique, the causal relationships among social capital, IT infrastructure, knowledge management processes, and organizational performance were confirmed. Hence, it is concluded that social capital and IT infrastructure have direct effects on knowledge management processes, and indirectly influence organizational performance through the degrees of knowledge management processes.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.67-85
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• 2002

This study analysed how to divide the maintenance of infrastructure in overseas countries' rail reform from train operation to get implications for KNR's reform. Sweden and United Kingdom divided the maintenance of infrastructure from train operation. France divided the two functions just only in laws and train operator is entrusted the maintenance of infrastructure. Germany divided the two functions but not completely, so integrated indirectly through the holding company, DB AG. Japan integrated the two functions into train operator, but separated the construction of infrastructure from the train operator. From these analysis, the authors suggest to make clear the goals of rail reform to assess the success or failure of dividing the two functions directly or indirectly.