• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1331-1338
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• 2010

Recently, the need for improving the economical efficiency of pumped-storage power plants has increased because of the decrease in the availability of electricity caused by an increase in the consumption of electricity at night. Therefore, a preventative maintenance cycle, especially an overhaul cycle, is required. Unconditional extension cannot be implemented because it may cause unanticipated failures due to insufficient maintenance. Therefore, in this study, a methodology for optimizing the preventative maintenance cycle by taking into account both reliability and economical efficiency is presented; this methodology has been developed by reviewing previous studies on reliability and considering the characteristics of pumped-storage power plants. Finally, an extended overhaul cycle is derived by applying this methodology to a domestic pumped-storage power plant.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.199-207
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• 2016

The number of multicultural families is on the rise worldwide. In this respect, the central government and municipal governments are also implementing and supporting multicultural-related policies. However, they are in progress, not as services needed for multicultural members but as policy issues. This causes multicultural members to fail to figure out the need of policies supported by the government or local governments, as well as to grasp the desire for what services in need are. In addition to this, many studies regarding multiculture are under way but few studies have been known so far as to multicultural business models. This study has suggested a final business model and strategy methods by designing, comparing and analyzing a business model needed for multicultural members through interviews with professionals and multicultural members with regard to mulcultural policies and examples in Korea.

• Food Science and Preservation
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• v.11 no.2
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• pp.142-147
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• 2004

To develop the red pepper seasoning oil(RPSO), corn oil was used as the base oil. For generating hot taste and color, oleoresin capsicum and oleoresin paprika were mixed to base oil (SSO1). Then, for generating black red color, natural black pigment that is extracted from gardenia and kaoliang was added SSO1 to prepare SSO2. To magnify the hot taste, extract of red pepper, phosphoric salt and emulsifier (monogly 20) were. then added to SSO2 to prepare SSO3. This SSO3 was very similar to real red pepper seed oil as a color and taste, but its hot flavor was not enough. To resolve this problem, we mixed about 5% of another oil(SSO4), which was mingled and roasted red pepper powder with corn oil, to SSO3. In terms of above experiment, RPSO was obtained.

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.33-42
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• 2018

In the aftermath of an earthquake, seismic-damaged infrastructure systems loss estimation is the first step for the disaster response. However, lifeline systems' ability to supply service can be volatile by external factors such as disturbances of nearby facilities, and not by own physical issue. Thus, this research develops the bayesian model for probabilistic inference on common-cause and cascading failure of seismic-damaged lifeline systems. In addition, the authors present network robustness estimation metrics in the context of failure propagation. In order to quantify the functional loss and observe the effect of the mitigation plan, power and water supply system in Daegu-Gyeongbuk in South Korea is selected as case network. The simulation results show that reduction of cascading failure probability allows withstanding the external disruptions from a perspective of the robustness improvement. This research enhances the comprehensive understanding of how a single failure propagates to whole lifeline system performance and affected region after an earthquake.

• Environmental and Resource Economics Review
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• v.18 no.4
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• pp.715-744
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• 2009

This study was analyzed the change of the tariff reduction for the Korea's fishery according to the Non Agricultural Market Access(NAMA) negotiations of the WTO. Four scenarios of tariff liberalization of NAMA are conducted on the basis of a Swiss formula. Using import demand function, we estimated price elasticities of imported fishery. The results of the analysis with mark up 20% show that, in the position of developed member, the value of import increase was between 405 billion won and 439 billion won, and analyzed between 232 billion won and 254 billion won with less than cut 50%. On the other hand, in the position of developing country, the value of import increase was between 311 billion won and 356 billion won, and analyzed between 174 billion won and 201 billion won with less than cut 50%. Also, the results was showed that the highest effects for increasing value of import are a fresh Pollack.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.37-52
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• 2022

The purpose of this study is to analyze the demand for cultural ecosystem services in urban forests based on user perception and experience value by using Naver blog posts and LDA topic modeling. Bukhansan National Park was used to analyze and review the feasibility of spatial assessments. Based on the results of topic modeling from blog posts, a review process was conducted considering the relevance of Bukhansan National Park's cultural services and its suitability as a spatial assessment case, and finally, an index for the spatial assessment of urban forest's cultural service was derived. Specifically, 21 topics derived through topic analysis were interpreted, and 13 topics related to cultural ecosystem services were derived based on the MA(Millennium Ecosystem Assessment)'s classification system for ecosystem services. 72.7% of all documents reviewed had data deemed useful for this study. The contents of the topic fell into one of the seven types of cultural services related to "mountainous recreation activities" (23.7%), "indirect use value linked to tourism and convenience facilities" (12.4%), "inspirational activities" (11.2%), "seasonal recreation activities" (6.2%), "natural appreciation and static recreation activities" (3.7%). Next, for the 13 cultural service topics derived from data gathered about Bukhansan National Park, the possibility of spatial assessment of the characteristics of cultural ecosystem services provided by urban forests was reviewed, and a total of 8 cultural service indicators were derived. The MA's cultural service classification system for ecosystem services, which was widely used in previous studies, has limitations in that it does not reflect the actual user demand of urban forests, but it is meaningful in that it categorizes cultural service indicators suitable for domestic circumstances. In addition, the study is significant as it presented a methodology to interpret and derive the demand for cultural services using a large amount of user awareness and experience data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.679-689
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• 2013

To relieve Green-house Gas Emission is the key issue in urban area. Urban transport policies have focused on the reduction of private car use. The most common of these is Travel Demand Management(e.g., congestion charge, environmental tax, etc.) that forces individuals to reduce their private car use. An alternative way is Mobility Management(MM) that induces individuals to voluntarily change their car use through communications. MM is founded on social psychology theory and focuses on individuals' decision making processes to change their perception and attitude on private car use. Although some researchers have reported the relevance of MM approach, still few researches have explicitly studied on individuals' decision making processes. Therefore, the aims of the paper are to analyze the decision making process of individuals and to provide the basis of introducing MM approach in Korea. Structural equation model(SEM) is applied for the analysis of individuals' decision making process. A empirical study shows that psychological factors such as perception/attitude on global environment or individual norms impact significantly to reduce private car use and accordingly the relevance of introducing MM approach instead of imposing regulations or expanding transport facilities.

• Atmosphere
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• v.31 no.2
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• pp.241-249
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• 2021

A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.

• Journal of Nutrition and Health
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• v.48 no.5
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• pp.407-418
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• 2015

Purpose: Given that the indicators related to chronic diseases are important to evaluating goals of the national health policy, the aim of this study was to develop dietary behavior items available in the Korea National Health and Nutrition Examination Survey. Methods: The dietary behavior items were developed based on the literature reviews, need assessment of the field, expert focus-group interviews, and expert advisory meeting. Questions for each dietary behavior item were developed by reflecting on environmental, personal, and behavior factors of the ecological frame and then revised through expert focus-group interview and expert advisory meeting. The understanding and reliability of the developed questionnaire were assessed by cognitive interview and test-retest reliability. Results: The developed items were sodium and salt intake, added and simple sugar intake, enough time to consume a meal for all ages, caffeine drinks and fresh/healthy food intake for children and adolescents, and limited dietary intake, fresh/healthy food intake for seniors. In most questions except some questions on sodium and salt intake, subjects understood over 70% and consistency of responses based on the kappa values was acceptable. Conclusion: Developed dietary behavior items are expected to be useful for evidence-based nutrition policy, interventions and research targeting dietary patterns through investigating and monitoring dietary behavior patterns.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.147-157
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• 2022

This study tried to propose a smart farm technology strategy suitable for the domestic situation, focusing on the differentiation suitable for the domestic situation of ICT technology. In the case of advanced countries in the overseas agricultural industry, it was confirmed that they focused on the development of a specific stage that reflected the geographical characteristics of each country, the characteristics of the agricultural industry, and the characteristics of the people's demand. Confirmed that no enemy development is being performed. Therefore, in response to problems such as a rapid decrease in the domestic rural population, aging population, loss of agricultural price competitiveness, increase in fallow land, and decrease in use rate of arable land, this study aims to develop smart farm ICT technology in the future to create quality agricultural products and have price competitiveness. It was suggested that the smart farm should be promoted by paying attention to the excellent performance, ease of use due to the aging of the labor force, and economic feasibility suitable for a small business scale. First, in terms of economic feasibility, the ICT technology is configured by selecting only the functions necessary for the small farm household (primary) business environment, and the smooth communication system with these is applied to the ICT technology to gradually update the functions required by the actual farmhouse. suggested that it may contribute to the reduction. Second, in terms of performance, it is suggested that the operation accuracy can be increased if attention is paid to improving the communication function of ICT, such as adjusting the difficulty of big data suitable for the aging population in Korea, using a language suitable for them, and setting an algorithm that reflects their prediction tendencies. Third, the level of ease of use. Smart farms based on ICT technology for the development of the Industry6.0 (1.0(Agriculture, Forestry) + 2.0(Agricultural and Water & Water Processing) + 3.0 (Service, Rural Experience, SCM)) perform operations according to specific commands, finally suggested that ease of use can be promoted by presetting and standardizing devices based on big data configuration customized for each regional environment.