• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.8-15
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• 2018

New methodology for probabilistic reliability based grid expansion planning of HVDC in power system including Wind Turbine Generators(WTG) is developed in this paper. This problem is focused on scenario based optimal selection technique to decide best connection bus of new transmission lines of HVDC in view point of adequacy reliability in power system including WTG. This requires two kinds of modeling and simulation for reliability evaluation. One is how is reliability evaluation model and simulation of WTG. Another is to develop a failure model of HVDC. First, reliability evaluation of power system including WTG needs multi-state simulation methodology because of intermittent characteristics of wind speed and nonlinear generation curve of WTG. Reliability methodology of power system including WTG has already been developed with considering multi-state simulation over the years in the world. The multi-state model already developed by authors is used for WTG reliability simulation in this study. Second, the power system including HVDC includes AC/DC converter and DC/AC inverter substation. The substation is composed of a lot of thyristor devices, in which devices have possibility of failure occurrence in potential. Failure model of AC/DC converter and DC/AC inverter substation in order to simulate HVDC reliability is newly proposed in this paper. Furthermore, this problem should be formulated in hierarchical level II(HLII) reliability evaluation because of best bus choice problem for connecting new HVDC and transmission lines consideration. HLII reliability simulation technique is not simple but difficult and complex. CmRel program, which is adequacy reliability evaluation program developed by authors, is extended and developed for this study. Using proposed method, new HVDC connected bus point is able to be decided at best reliability level successfully. Methodology proposed in this paper is applied to small sized model power system.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.2
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• pp.96-109
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• 2023

Recently, there has been a lot of discussion about the regional pricing of electricity and electricity self-sufficiency. In Korea, power generation facilities are highly ubiquitous and there is an imbalance between electricity production and consumption regions. So it is proposed to charge different price by region, instead of the current nationwide uniform price, and the regional electricity self-sufficiency rate is proposed as a criterion for identifying electricity production and consumption regions. However, many discussions set the spatial unit for measuring electricity self-sufficiency by 17 Si·Do, which needs to be analyzed for its appropriateness. In this study, we analyzed the electricity self-sufficiency rate using 17 provinces and 229 Si·Gun·Gu as the spatial unit. As a result of the analysis, there are 7 and 10 electricity producing and consuming regions at Si·Do level, but 38 and 191 at Si·Gun·Gu level. In addition, although the electricity self-sufficiency rate measurement has the advantage of identifying electricity production and consumption areas in a simple and intuitive way, we points out that it has some problems with the criteria for regional pricing of electricity.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.205-216
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• 2018

Objectives: Scientific verification for health effects has been constantly demanded through the forest healing factors. In this study, phytoncide concentration which is one of the forest healing factors, was investigated according to stand density, season and visiting time, and analyzed correlation with micrometeorology factors. Methods: Total volatile organic compounds (TVOCs) and Natural volatile organic compounds (NVOCs) were collected using a measuring instrument which is connected to an air pump with the Tenax TA tube. The 32NVOCs were selected through the detailed criteria of adequacy assessment for recreational forest. The statistical analysis (correlation and stepwise regression analysis) was conducted between phytoncide concentration and micrometeorology factors. Results: NVOCs concentration linearly increased according to stand density. The high level showed in the summer (p<0.05), and there is no significant difference according to visiting hours of the Healing forest. NVOCs is a negative correlation with solar radiation, PAR and wind direction, and a positive correlation with relative humidity and temperature (p<0.01). NVOCs increased following the increase of humidity and temperature ($R^2=0.55$). Conclusions: Phytoncide linearly increased according to stand density, and showed the correlation significantly with microclimate factors. In future, these results will be utilized as a basic material to promote the generation of phytoncide, which positively influences human health promotion and manage the forest welfare space.

• Journal of Digital Convergence
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• v.10 no.1
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• pp.277-291
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• 2012

Smartphone (smartpad) and cloud computing has grown rapidly. So, the users started getting interested in multi-screen services. However, various OS / platforms due to the increased content development time and cost. Increase the cost of content development for a multi-screen service, it has been an obstacle. To solve this problem in this study, HTML5-based multi-screen service platform standards specification was established. HTML5 is a specification of the next generation of Web standards. Standards specification established by this study were research in terms of the service provider. And, this standards specification can be used independently of the service infrastructure and device. In addition, this standards specification in order to develop a multi-screen services are efficient and easy to use. For verification adequacy of standards specification established in this study, Scenarios technical entries were mapped by standard specification entries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2117-2125
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• 2009

This paper describes an information system of operation adequacy in environmental facilities such as environmental contamination prevention and processing equipments, which is namely, an integrated management system for environmental facilities. By developing this system, we can improve environmental characteristics and maximize the efficiency throughout the life cycle from generation of contaminant source to contamination prevention processing, and to contaminant disappearance. In order to meet these objects, we have developed ubiquitous life cycle assessment(u-LCA) for environmental facilities, which is an ISO14001-based incineration facility information system. The developed system is currently operating for test at an incinerator in Koyang city. Due to this system, the managers can confirm the operation condition of the incinerator with real-time and they will be able to improve the problems immediately.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.341-363
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• 2012

The spectral representation method is a quick and versatile tool for the generation of spatially variable, response-spectrum-compatible simulations to be used in the nonlinear seismic response evaluation of extended structures, such as bridges. However, just as recorded data, these simulated accelerations require processing, but, unlike recorded data, the reasons for their processing are purely numerical. Hence, the criteria for the processing of acceleration simulations need to be tied to the effect of processing on the structural response. This paper presents a framework for processing acceleration simulations that is based on seismological approaches for processing recorded data, but establishes the corner frequency of the high-pass filter by minimizing the effect of processing on the response of the structural system, for the response evaluation of which the ground motions were generated. The proposed two-step criterion selects the filter corner frequency by considering both the dynamic and the pseudo-static response of the systems. First, it ensures that the linear/nonlinear dynamic structural response induced by the processed simulations captures the characteristics of the system's dynamic response caused by the unprocessed simulations, the frequency content of which is fully compatible with the target response spectrum. Second, it examines the adequacy of the selected estimate for the filter corner frequency by evaluating the pseudo-static response of the system subjected to spatially variable excitations. It is noted that the first step of this two-fold criterion suffices for the establishment of the corner frequency for the processing of acceleration time series generated at a single ground-surface location to be used in the seismic response evaluation of, e.g. a building structure. Furthermore, the concept also applies for the processing of acceleration time series generated by means of any approach that does not provide physical considerations for the selection of the corner frequency of the high-pass filter.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.151-158
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• 2019

Wireless communication technology (WAVE) for vehicles, which is the core technology behind the next-generation intelligent transport system (C-ITS), is used to deliver information about vehicles to prevent traffic accidents and traffic situations that may arise between vehicles and infrastructure. Similar traffic issues often arise in marine scenarios. Currently, AIS is being used as a means of transmitting information such as the status of relative vessels, but research is being carried out to solve problems with AIS such as overloading by applying wireless communication technology for vehicles to the sea. In this study, a collision warning system suitable for small-sized vessels was developed based on the marine application of WAVE for vehicles verified through prior research, and the adequacy of this collision warning system was reviewed through a practical test. It is expected that this system will contribute greatly to future e-Navigation applications or self-driving ships as well as to preventing marine accidents.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.65-77
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• 2022

Due to muddy water from the highland fields upstream of Soyangho Lake, the Mandae, Gaa, and Jawoon have been redesignated as NPS management areas. This study aims to evaluate the adequacy and supplementation points of the implementation plan by analyzing the operation status of muddy water generation and reduction facilities through on-site investigations by NPS management area to achieve the effective nonpoint pollution reduction goal in the implementation of the implementation plan established in 2020. The SS load calculated based on the survey results from July to October 2019 from 2017 showed a decreasen in 2019 compared to 2017. Both and the Jawoon were analyzed to have decreased. However, the amount of precipitation also decreased by about 27%, so it was judged that the effect of the reduction project was not significant. As a result of the detailed investigation of abatement facilities, about 86% of the 793 facilities installed in the management area were evaluated as 'good'. As a result of a detailed investigation by subwatersheds, subwatersheds 105 and 106 in the Mandae were analyzed as apprehensive subwatersheds. appeared to fall. In addition, it was analyzed that the effect of reducing muddy water in the Mandae district was insufficient due to the high ratio of leased farmers, lack of efforts to reduce turbid water in leased farmland, conversion to annual crops, and neglect of bare land. In the case of Gaa district, although the abatement facilities are concentrated in the upstream, muddy water was also found to be severe.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.252-259
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• 2022

In order to discuss the implications for demographic changes due to an aging society, this study sought to verify the effect of generational age with a focus on the case of the national housing scale transaction in Seoul Seocho-gu. For the result, variance and linear regression analysis, and when the analysis showed a significant correlation between age and transaction price, and corrected the trading region and year, it was also confirmed that the higher the age in most regions, the lower the trading price tendency. Based on the results of this analysis, efforts to improve the adequacy and fairness of pricing in trading cases, and the direction of policy change due to the aging of the population were discussed, and on the basis of this, we even proposed measures for the support of the policy authorities. In addition, the management condition of individual communal houses was an important factor in the sale and the lack of utilization of Internet-based platforms was expected to be the cause of the low price sale. However, due to the use of 2nd order data on real trading cases, the direction of subsequent research was presented together with respect to the limitations of not being able to control a wider variety of individual characteristics.

• Journal of Korean Society of Rural Planning
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• v.28 no.4
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• pp.55-67
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• 2022

In this study, the village development promotion system was reorganized for Gimhae-si, and improvement plans and post-operation management plans were prepared through expert surveys. Through the Village Development Project, the landscape and environment of the village were improved, and the village and residents were positively changed. The Village Development Project laid the foundation for regional revitalization, giving the next generation hope for the sustainable development of the village. While maintaining the framework of the existing Rural Development Projects guidelines through case analysis of other regions, we operate educational programs for each stage by reflecting regional characteristics, and utilize and communicate with intermediate support organizations, systematically operate, and actively intervene by Eup·Myeon administration. In addition, as a follow-up management program, various follow-up management programs were being operated, such as support for capacity building such as consulting, as well as facility maintenance and support for village managers. As a result of the expert survey to review the adequacy of the improvement plan, the improvement plan derived from the overall average of 4.28 points and the standard deviation of 0 to 0.94 points for the process is judged to be appropriate. In particular, the item of 'self-reliance stage follow-up management' was very important as all experts responded with 5 points. By establishing the village development performance goals, we tried to check whether the qualitative/quantitative goals were achieved by year, and to secure quantified status data in response to changes such as resetting performance goals or adding new performance indicators. In this study, in order to improve the capacity to achieve regional development in response to the rural agreement, we prepared our own sustainable village development promotion system, governance establishment, and follow-up management plan. In addition, it is expected to be used as a reference material for the selection of new districts and the follow-up management of completed districts by establishing the village development goals.