• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.117-119
• /
• 1995

For an effective application of the cogeneration system for commercial and industrial buildings, we need to develop a relevant model to determine the long-term based optimal sizing of the cogeneration system considering electrical and thermal load demands, buy and sell contracts with electric utility and the annual production cost. In assessing the optimal sizing of cogeneration, we have to consider both economic parameters and their capacity expansion for the increased electrical and thermals demand in the future. In this paper, we propose a mathematical model for the optimal sizing of cogeneration systems considering annual production costs and other economic parameter such as, lifetime of the equipment, time value of the capital, etc. In the case study, we thoroughly examine the effects of the economic parameters and determine the optimal size of the sample system. In addition, we calculate the payback period of the cogeneration investment.

• 농촌계획
• /
• 제4권2호
• /
• pp.79-88
• /
• 1998

The purpose of this study was to identify factors related to residential satisfaction, and to examine the rural housing and village environment which enable to derive what should be considered in the future rural housing improvement. Data were collected by questionnaire survey in 11 rural villages - suburban rural area, plain rural area, intermediate rural area, mountainous rural area. The major findings are as follows: 1) The rural residents rather dissatisfied with'management/maintenance','economic value','facade'in housing level, The overall housing satisfaction level was just medium(neither satisfied nordissatisfied). 2) They also dissatisfied with'playground for children','education condition','medical facilities', 'market'in village level. The overa'll village satisfaction level was just above average(slightly satisfied). 3) Vrom the result of ANOVA test, there are no significant differences in residents evaluation for tiousing and village attributes among 4 rural areas. 4) Factor analysis identified six rural housing environmental factors:'inside utilities','housing size' 'aesthetic aspects','safety','privacy','outside utilities'. 5) For the rural village environments six important factors were derived :'public services','commercial convenience facilities','social interaction','environmental pollution','amenity','agricultural service facilities'.

• 신재생에너지
• /
• 제8권4호
• /
• pp.21-29
• /
• 2012

The extensible supply of New & Renewable energy resources desperately needs to counter the high dependence on imported energy, recent high oil prices and the Climate Change Conference, and the government has operated the 'Renewable Portfolio Standard' (RPS) as one of the renewable energy policy from 2012. By analyzing the operation case of combined heat and power plant using the woodchip biomass, we drew the price of wood chip fuel, plant capacity factor, electricity selling price, heat selling price and LCOE value. After analyzing the economic feasibility of 3MWe combined heat and power plant based on the operating performance, the minimum of economic feasibility has appeared to be secured according to the internal rate of return (IRR) is 6.34% and the net present value (NPV) is 3.6 billion won as of 20 years life time after installation, and after analyzing the cases of the economic feasibility of the price of wood chip, plant capacity factor, electricity and heat selling price are changed, the economic feasibility is valuable when the price of wood chip is over 64,000 won/ton, NPV is minus, and the capacity factor is above 46.9%, the electricity selling price is 116 won/kWh and the heat selling price is above 75,600 won/Gcal. When going over the new installation hereafter, we need the detailed review of the woodchip storage and woodchip feeding system rather than the steam-turbine and boiler which have been inspected many times, the reason why is it's hard to secure the suitable quality (constant size) of woodchip by the lack of understanding about it as a fuel because of the domestic poor condition and the calorific value of woodchip is seriously volatile compared with other fuels.

• Journal of Korea Trade
• /
• 제27권2호
• /
• pp.47-60
• /
• 2023

Purpose - This paper assesses the trade potential and efficiency of Korea and China in the aquatic products trade. Trade efficiency and potential are the main factors that affect the growth of a country's trade. In this study, a time-varying stochastic frontier trade gravity model was constructed to analyze the trade potential and efficiency between Korea and China. By integrating the results of trade theory and empirical analysis, measures and suggestions were proposed to encourage the release of trade potential of fish exports between Korea and China. Design/methodology - In this paper, GDP per capita instead of economic size was chosen as an explanatory variable, and population size and relative distance were selected as explanatory variables to measure trade potential. For trade non-efficiency terms, regional organizations, political factors, and economic factors were mainly considered, and variables such as free trade agreements, political stability, regulatory quality, government efficiency, currency freedom, investment freedom, financial freedom, and trade freedom were selected. Panel data for South Korea and 14 aquatic products trading partners (including China) from 2002 to 2020 were used in the empirical analysis. Findings - In the past 19 years, South Korea's export trade potential of aquatic products to China has never been lower than 70%. It was above 90% from 2006 to 2018, and has been at a high level for a long time. This shows that China's aquatic product market has large potential for development. Originality/value - This study examines the effectiveness and potential of South Korea's exports of aquatic items to China in a methodical and comprehensive empirical manner. The evaluation of the export trade potential of South Korea's aquatic goods to China is more precise when the effects of regional organization, political, and economic variables are taken into account in the trade non-efficiency term of the stochastic frontier gravity model. At the same time, we propose to increase the scale of South Korea's aquatic products trade from the perspective of China's demand. This issue of trade studies is underexplored both empirically and in theory, although the issue has long been important to Korean and world trade.

• 한국산학기술학회논문지
• /
• 제20권12호
• /
• pp.15-20
• /
• 2019

본 연구에서는 교대에 작용하는 수평력을 저감시키는 총 11 케이스의 설계에 대한 건설비 분석을 실시하였다. 역T형 교대의 뒤채움재 개선과 토목섬유 보강재를 이용하여 교대를 보강한 철도용 보강 교대(Reinforced Abutment for Railways) 적용을 고려한 2종류의 교대 형식에 대하여 검토하였다. 첫 번째 종류의 경제성 분석에서는 역T형 교대의 배면 뒤채움 재료의 내부 마찰각을 35°에서 40°와 50°로 증가시키는 케이스를, 두 번째 종류의 경제성 분석에서는 토목섬유를 적용한 철도용 보강 교대 설계 케이스에 대한 경제성을 비교 분석하였다. 뒤채움 재료의 개선을 통해 내부 마찰각을 40° 혹은 50°로 적용할 때 교대에 가해지는 수평토압은 하중 조건에 따라 18~48% 까지 감소하였으나 교대 건설 비용 저감효과는 2.0~3.9%로 크지 않았다. 그러나, 철도 교대 구조로서 토목섬유 보강 교대를 적용한 결과 교대에 작용하는 수평력을 이론적으로 0까지 저감시킬 수 있어 교대 벽체 두께, 저판 길이 및 말뚝 기초의 수 및 재질 변경으로 최대 30%까지 건설비 저감 효과가 있는 것으로 검토되었다.

• 한국의류학회지
• /
• 제38권5호
• /
• pp.690-704
• /
• 2014

This study examined the risk perception in internet shopping by Chinese and analyzed the effects of risk perception on internet word-of-mouth acceptance and transmission. This analysis was conducted with data collected from 373 Chinese individuals in their 20s. Data were analyzed with factorial analysis, cluster analysis, ANOVA, multiple regression analysis, Chi-square test, and Cronbach's ${\alpha}$ using SPSS 18.0. The results were: 1) The factor analysis of risk perception extracted four factors: fashion/social psychological risk, product risk, transaction risk, and economic risk. The cluster analysis classified them into: Group with low-risk, Group with high-risk, Group with economic risk, and Group with medium-risk. 2) Group with high-risk and Group with economic risk had a higher word-of-mouth acceptance than other groups. The Group with a high-risk had more word-of-mouth transmission than other groups. 3) It was found that when word-of-mouth was accepted, the factual information about fashion products (size and material) was most referred to, and that the overall evaluation of satisfaction and dissatisfaction was most conveyed when word-of-mouth was conveyed. 4) Internet word-of-mouth acceptance was affected by product risk, economic risk, and transaction risk. Internet word-of-mouth transmission was affected by economic risk, and fashion/social psychological risk, product risk, and transaction risk.

• 한국건축시공학회지
• /
• 제13권3호
• /
• pp.291-305
• /
• 2013

This paper presents the continuous hoop reinforcement method as a means to overcome the difficulty of rebar construction due to the seismic detail of lateral reinforcement. Because the continuous hoop has no seismic hook, and there is less interference during the rebar work, rebar quantities and construction time can be reduced. Since the details of column and beam continuous hoops are different from those of conventional lateral reinforcements, the construction method should be developed through mock-up tests. The length of the beam mock-up is 8m and the section size is $500mm{\times}700mm$, the height of the column mock-up is 2.8m and 4m, and the section size is $800{\times}800mm$. The length and the size are determined based on the elements that are generally used in reinforced concrete basement parking lots and office buildings. The results of the mock-up test showed that the quantities of rebar could be reduced by 20% and the time could be reduced by up to 40% compared with conventional lateral reinforcements.

• 기술혁신연구
• /
• 제16권2호
• /
• pp.125-145
• /
• 2008

The paper evaluates the Korean science, technology, and innovation policy(STIP) in terms of an individual firm. The firm is Viromed(Ltd), a new technology-based venture company in the field of biotechnology. The case is compared with the 'Hwang Project', which is known as a typical failure case in Korea. In order to evaluate the Korean STIP, we establish 6 areas, which are technological infrastructure, institutional infrastructure, human capital infrastructure, technology market, industrial base, and innovation networks. The study shows that the policy schemes relating with technological infrastructure, institutional infrastructure, human capital infrastructure, and industrial base play a positive role in the start-up, development and innovation of Viromed(Ltd). However, we can hardly find the role of Korean government in fostering the technology market, transferring the technological output to economic performance. Although the international networks with the British, American, and Japanese firms or investors were a key success factor of the growth of Viromed(Ltd), the role of the government in this policy area was not enough. As for the 'Hwang Project', we suggest that the government should consider the possibility of commercialization in choosing R&D projects and determining the size of financial aids. Since the evaluation of the Korean STIP is based on an individual firm, the results of the paper need to be confirmed by a systematic comparison with other cases or industries.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권11호
• /
• pp.549-556
• /
• 2020

Real estate markets play an essential role in the economic development of both developed and developing countries. Investment decisions in private real estate demand the consideration of several qualitative and quantitative criteria. Especially in Vietnam, demand for housing, apartments are rising which has resulted because of the migration from rural to urban areas. This study aims to determine the influencing factors of the real estate purchasing behavior and then recommend a grey Multi-Criteria Decision Making (MCDM) support model to evaluate real estate alternatives based on a numerical example in Vietnam. A set of essential criteria are identified based on experts' opinion, and the proposed determinants are initial investment, maintenance cost, prestige location, distance to interesting places, parking lot, public transportation, property condition, total area size, number of rooms, and neighbors. The subjective weights were obtained by using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) model, and the Grey Relational Analysis (GRA) technique is employed to prioritize and rank real estate alternatives. The results reveal that this approach can be useful to make purchasing decisions for many kinds of real estate property under uncertain business environments. These findings indicate that the presented hybrid model has advantages in granting flexibility to the preferences of decision makers.

• 조명전기설비학회논문지
• /
• 제18권4호
• /
• pp.165-170
• /
• 2004

정전에 따른 직접적이고 단기간의 정전비용을 평가하기 위해 산업용 수용가를 대상으로 설문조사 결과를 요약한 것이다. 설문지는 주로 수용가의 전기전문가를 대상으로 예상되는 예비 조치에 바탕을 두고 작성되었다. 정전의 기간과 빈도를 고려한 신뢰성에 대한 경제성 평가는 어떠한 종류의 정전에 의해 유발되는 특히 대규모 산업용 수용가의 손실과 경제적인 충격을 정확히 반영하지 못했다. 수용가 집단에 초래되는 비용의 큰 차이를 내포시키기 위해 본 정전비용을 분석함에 있어서 IEC, IEEE와 같은 국제 규격을 활용하였다.