• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.67-74
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• 2021

Domestically, technical condition evaluation for breakwaters has been conducted through safety checks and safety diagnosis. If necessary, maintenance for the facility is conducted. However, in recent years, the need for infrastructure management has been increasing from a life-cycle-cost perspective. For these reasons, the "Sustainable Infrastructure Management Basic Act" was enacted. Previously, only the technical part of the breakwaters was evaluated. However, based on the act, comprehensive management of breakwaters will be possible through performance improvement by adding economic and political evaluations. In this study, evaluation factors and evaluation methods were developed for a breakwater rehabilitation project. The purpose of this study is to present a development direction, items, and methods for the evaluation of breakwater performance improvement to be applied in future practice. This study reviews the concept of maintenance and performance improvement, the literature related to performance improvement, and the project type for the common standard of performance improvement. Evaluation items and evaluation methods for breakwater rehabilitation are suggested to be reviewed by experts. The methodology suggested in this study could be used for preventive maintenance and to reduce accidents.

• Korean Journal of Social Welfare Studies
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• v.41 no.3
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• pp.29-56
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• 2010

One of the most popular keywords in 21th century is "Information Society". Information Society improves the overall quality of human life, but increases the negative aspects such as internet addiction and digital divide. The purpose of this study is to understand the vicious cycle between socio-economic disparities and digital divide. This study analyzed the effects of poverty on school maladjustment and academic achievement and mediation effects by using parental monitoring and internet use types as mediators. Data were obtained from the Korea Youth Panel Survey(KYPS). Structural equation modeling was employed for statistical analyses. The result showed that poverty reduced parental monitoring and information-oriented type of internet use. Youth who used less information-oriented type showed more school maladjustment and less academic achievement. However, the relationship between poverty and entertainment-oriented type was non-significant. Thus, parental monitoring and the internet use types were one of the main pathways which can affect school maladjustment and academic achievement among youth in poverty. There was the possible vicious cycle between poverty and digital divide. Based on this study, we strongly suggest improvement of the media competence to solve the problem of digital divide among youth in poverty.

• Korean Chemical Engineering Research
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• v.62 no.3
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• pp.225-232
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• 2024

The reduction of CO₂ emissions in the energy production sector, which accounts for 86.8% of total greenhouse gas emissions, is important to achieve carbon-neutrality. At present, 60% of total power generation in South Korea is coal and natural gas. Replacing fossil fuel with renewable energy such as wind and solar has disadvantages of unstable energy supply and high costs. Therefore, this study was conducted through the co-firing of natural gas, ammonia and hydrogen utilizing the natural gas combined cycle process. The results demonstrated reduction in CO₂ emissions and 34%~238% of the power production compared to using only natural gas. Case studies on mass fractions of natural gas, ammonia and hydrogen indicated that power production and NO_x emissions were inversely proportional to the ammonia ratio and directly proportional to the hydrogen ratio. This study provides guidelines for the use of various fuel mixtures and economic analysis in co-firing power generation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.255-265
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• 2014

Job creation is foundation for wealth creation of the individual personal and important social activities that can solve the problem through increased economic activity and decreased population of unemployment. Jab creation contributes to the best way to solve social problems by acting as mediator of economic stability by establishment to a virtuous cycle between growth and employment and providing the foundation for sustainable growth. In this study, the factors affect on entrepreneurship and professional values were studied on the vocational personality types of student. As a result of this study, Vocational personality types positive commitment to the entrepreneurship. Realistic, exploratory, artistic, social, persuasive and customary factors also positive commitment the entrepreneurship. Vocational personality types positive commitment to the professional values. Professional values positive commitment to the entrepreneurship. However, the professional value factors which are self-actualization, safety, power, independence, community service and leadership depend on entrepreneurship. Therefore, in order to improve the success rate of student start ups, the appropriate selection of optional items of start ups and entrepreneurship education at the right time to establish a business plan by the type of vocational personality types and should provide the opportunity to encounter.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.3
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• pp.201-209
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• 2015

Currently, 23 nuclear power plants are in operation at Kori, Uljin, Younggwang and Wolsong site and a reference deep geological disposal system has been developed for the spent fuels generated by them. The reference spent fuel for this disposal system has 4.5wt% of initial enrichment, 55 GWd/MtU of burn-up, and 40 years of cooling time. In this paper, to improve disposal efficiency and economic feasibility, the characteristics of spent fuels from nuclear power plants, such as type and burn-up, were reviewed. A disposal canister concept for shorter length and relatively lower burn-up spent fuels than the reference spent fuels was developed. Based on this canister concept, thermal analyses were carried out and a deep geological disposal concept was proposed. Measures of disposal efficiency such as unit disposal area and disposal density were compared between this disposal system and the reference disposal system. Also, economic feasibility, such as the volume reduction of copper, cast iron, and bentonite, was analyzed and the results of these analyses showed that the disposal system proposed in this paper has an efficiency of at least 20%. These results could be used for establishing spent fuel management policy and designing practical disposal systems for spent fuels.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.1-15
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• 2015

During global recessions, such as the 2008 financial crisis, Korean shipping companies have been undergoing a liquidity crisis that is comparably worse than other shipping companies worldwide. One of the reasons behind this repetitive vicious cycle can be the lack of ability to foresee the future by analyzing and understanding the volatile shipping market. Traditionally, in order to assimilate the shipping market, larger Korean shipping companies have been purchasing market reports published by Europe-based research companies and shipping brokers, leading to a digital divide by company size. To resolve this issue, the Maritime Exchange Information Center (MEIC) has been publishing shipping market reports that include essential shipping information such as freight rates by different routes; commodity trends for iron ore, grain, and coal; ship-building trends for new-building, second-hand, and demolition markets; as well as bunker price and port congestion. This research was conducted to analyze the effectiveness of four variables-information usefulness, market reflection, information composition, and latest information-on information satisfaction. If the information satisfaction was found to be adequate, the analysis of actual proof was used to determine if the customers would be willing to purchase MEIC's report when it is chargeable. All the four variables were found to have positive effects on information satisfaction. In particular, latest information was found to directly affect the intention to purchase. Furthermore, high information satisfaction was related to the intention to purchase.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.1
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• pp.51-67
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• 2016

Urban development-related growth in recent years has become a qualitative growth based on regional identity, rather than a hardware-based growth. For this purpose, strategic approaches to the value of cultural assets of the city are required for competitiveness of the city. In this paper, I seek a model for urban regeneration and regional development through empirical case studies of cultural assets and utilize the 'Seoul Fairy Tale Festival' in terms of strengthening regional competitiveness. By analyzing detailed elements of the 'Seoul Fairy Tale Festival' case, the hardware infrastructure, software and governance structures, diverse contentsware, ecosystem characteristics centered on the humanware, and circular structure was studied. As a feature of cultural assets, combined with the management of physical assets and operations of several programs, was the basis for creating a synergy effect of creating an identity for the region. In addition, it was confirmed the possibility of a regional-rehabilitation type of urban regeneration that is based on the expansion of existing facilities, and a regional-innovation type of urban regeneration that is based on a fusion of characteristics. This analysis is significant in terms of the possibility of large urban regeneration based on cultural assets associated with the festival, as well as physical assets and by combining various governance stakeholders for the festival, it can be concluded that it provided an indigenous virtuous cycle.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.389-401
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• 2007

The oxygen and hydrogen isotopic composition in precipitation, groundwater and geothermal water were monitored over four-year period from 2001 to 2004 at the Yuseong catchment, Daejeon. By analyzing the long term rainfall pattern, we found out the drought cycle of 6 or 7 year. We fortunately revealed that the oxygen and hydrogen isotopic composition of rain has progressively changed to heavier isotopic ratios from 2001 to 2004. The weighted mean values of ${\delta}^{18}O\;and\;{\delta}D$ of rain are calculated to be $-7.7%o\;and\;-51%o$, respectively. These isotopic values are much heavier than those of groundwater and geothermal water collected at the same period, which indicates that the rain or snow of the study area would not immediately affect the isotopic composition of groundwater or geothermal water. Comparing with the previous data, the groundwater and geothermal water collected at 1990 and 1992 year has the heaviest isotopic composition and afterwards their isotopic composition has been progressively shifted to the direction of lighter composition field.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.553-564
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• 2020

Transition between explosive and effusive eruption in Ulleung Island is observed in the Nari Scoria Deposits and Albong Trachyandesite (lava dome) origined by dome-building eruption and may be related to factors such as magma influx, ascent rate and degassing. However, the interpretation of them has not been resolved yet because the interaction between these factors is not complex but also the resulting behaviour during eruption is unpredictable. This paper focuses on the explosive and effusive activity perceived during building the Albong lava dome in Nari caldera. Samples were collected along with time from the scoria deposits and lava dome, linked to eruption stage and style of activity. Textures of groundmass feldspar microlites from these samples are quantitatively analyzed, including measurements of areal number density, mean microlite size, crystal aspect ratio, groundmass crystallinity and crystal size. The microlite textures show that shallow pre- and syn-eruptive magmatic processes acted to govern the changing behaviour during the eruption. Transition between explosive and effusive eruption was driven by the dynamics of magma ascent in the conduit, with degassing and crystallisation acting via feedback mechanisms, resulting in a cycle of effusive and explosive eruption.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.199-199
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• 2011

ATES(Aquifer Thermal Energy Storage) 열펌프 시스템은 기존의 다양한 열원 적용 시스템 대비 효율이 우수한 것으로 알려져 유럽과 미국에서 건물 냉난방 시스템으로 적용되고 있다. 특히, ATES 시스템은 기존의 냉난방 시스템 대비 경제성이 우수한 것으로 알려져 있으나 국내에서는 이에 대한 연구 결과는 전무한 실정이다. 본 연구에서는 ATES 열펌프 시스템의 실증 성능 결과를 분석하였으며, LNG 보일러와 에어컨을 사용하는 기존의 냉난방 시스템을 비교시스템으로 ATES 열펌프 시스템의 경제성 평가를 수행하였다. ATES 시스템의 연간 실증 성능 실험결과 ATES 시스템은 외기온도와 무관하게 연중 안정적인 성능을 나타내었다. 경제성 평가시에 생애주기법(Life Cycle Cost)을 적용하여 ATES 열펌프 시스템의 설치 및 운전에 필요한 총 소요비용을 산정하고, 이 결과를 바탕으로 투자회수기간법을 통해 ATES 시스템의 투자회수 기간을 산정하였다. 생애주기법 적용 시에 현재가치법을 사용하였으며, 현재가치법은 수명주기에 발생하는 모든 투자비용과 절감액을 일정한 시점을 기준으로 등가환산하는 방법을 의미한다. 현재가치법에 사용되는 현재가치는 초기비용과 현재가치계수의 곱으로 나타나는데, 여기에서 현재가치계수는 임의의 이자율로 일정기간 동안 정기적인 할부금액이 적립될 때의 현재금액을 구하기 위해 사용하는 계수를 의미한다. 전기와 LNG는 각각 2009년 7월의 (주)한국전력공사와 (주)한국가스공사의 고시요금을 적용하였다. 본 시스템은 실증 설비용량인 20RT를 대상 건물로 가정하였고, 초기투자비는 크게 공사비와 냉난방 설비 구입비로 구성되어 있으며, 기본적인 물가지표는 (사)한국물가정보(KPI)의 고시 데이터를 참조하였다. 각 시스템의 초기투자비는 ATES 시스템이 비교대상 기존 냉난방 시스템 대비 5.7배 높게 나타났다. 일일 8시간 사용기준으로 계절별 전력요금을 고려한 연간운전 비용은 ATES 시스템이 기존 시스템 대비 냉난방 시에 각각 77%와 16%를 나타내어 운전비용이 연간 절감되었고, 난방 운전 시 절감 비율이 냉방시보다 크게 나타났다. 두 시스템에 대한 생애주기비용을 산정하기 위하여 에어컨과 보일러의 기존시스템과 ATES 시스템의 가용연수를 모두 20년으로 설정하였고, 유지보수 비용은 초기투자비용의 2%로 설정하고, 할인율은 은행 예금이자를 기준으로 5%로 설정하였다. 전기와 LNG의 요금 상승률은 (사)한국물가정보를 바탕으로 각각 2%와 8%로 가정하였다. 이러한 조건에서 생애주기법을 이용한 경제성평가는 ATES 시스템의 경우 생애운전비용이 초기투자비용보다 작게 나타났으며, 기존 냉난방 시스템은 생애운전비용이 초기투자비용에 비하여 높게 나타났다. 본 연구 대상 ATES 열펌프 시스템의 실증 성능 데이터와 기존 문헌으로부터 얻은 냉난방 시스템의 성능 결과를 이용하여 생애주기 비용을 적용한 결과 ATES 시스템의 기존 시스템 대비 투자회수 기간은 6.62년으로 나타났다. 특히, 본 연구에서는 ATES 시스템이 국내 최초로 적용됨에 따라 스크린 등의 부품을 다소 고가의 제품으로 시스템에 적용하였으므로 ATES 시스템의 신뢰성과 안정성이 확보되면 초기 투자비 감소가 가능할 것으로 예상되며, 기존 시스템 대비 투자회수 기간은 더욱 감소될 수 있을 것으로 예상된다.