• Title/Summary/Keyword: Economic Scale

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Analysis of Economic Feasibility and Reductions of Carbon Dioxide Emission of Geothermal Heating and Cooling System using Groundwater (지하수를 이용한 지열 냉난방시스템의 경제성 및 이산화탄소 저감량 분석)

  • Kim, Jin-Sung;Song, Sung-Ho;Jeong, Gyo-Cheol;Cha, Jang-Hwan
    • The Journal of Engineering Geology
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    • v.25 no.4
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    • pp.599-612
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    • 2015
  • The development of renewable energy technologies that can replace fossil fuels is environmentally important; however, such technologies must be economically feasible. Economic analyses are important for assessing new projects such as geothermal heating-cooling systems, given their large initial costs. This study analyzed the economics and carbon dioxide emissions of: a SCW (standing column well), a vertical closed loop boiler, a gas boiler, and an oil boiler. Life cycle cost analysis showed that the SCW geothermal heating-cooling system had the highest economic feasibility, as it had the highest cost saving and also the lowest carbon dioxide emissions. Overall, it appears that geothermal systems can save money when applied to large-scale controlled agriculture complexes and reclaimed land.

Analyses of GHG Reduction Effectiveness and Economic Feasibility in the Wood Pellet Fuel Switching Project (목재 펠릿 연료전환 사업의 온실가스 감축 효과 및 경제성 분석)

  • Lee, Jin-Chul;Kang, Kyu-Young
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.6
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    • pp.594-605
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    • 2013
  • This study was performed to analyze GHG (Greenhouse gas) reduction effectiveness and economic feasibility in the wood pellet fuel switching project using JCDM (Japan Clean Development Mechanism) and KVER (Korea Voluntary Emission Reduction)data. The major data for the analyses consist of investment costs, annual GHG reductions, fuel prices and GHG credit prices. The wood pellet fuel switching projects are the $CO_2$-zero projects. Therefore, these projects are essential to accomplish the GHG mitigation target, especially in Korea. In order to raise the economic feasibility of the wood pellet fuel switching project, the results of this study suggest that the Korean government should reduce the price of wood pellet through the supply on a large scale and raise the KCER price of wood pellet fuel switching project.

Recognition of Forest Certification by Consumption Propensity and Socio-Economic Characteristics of Wood Cabinet Consumers (목재수납장 구매자의 소비성향 및 사회·경제적 특성에 따른 산림인증 인식도 조사)

  • Shin, Hye-Jin;Kim, Eui-Gyeong;Kim, Dong-Hyeon;Kim, Hyeon-Guen
    • Journal of agriculture & life science
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    • v.45 no.6
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    • pp.57-63
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    • 2011
  • This study was performed to figure out the recognition on forest certification by consumption propensity and socio-economic characteristics of wood cabinet consumers. The mean score of recognition on SFM and FSC showed comparatively low, 2.25 and 2.20(5-point likert scale), from the analysis result on 88 valid questionnaires of 90. The respondents rate of eco and non eco-friendly group formed 80.7% and 18.2%, there is a significant gap between two groups on total questionnaires. The percentage of respondents recognizing on SFM and FSC was about 31% (eco-friendly), 5.6%(non eco-friendly, SFM) and 2.8%(non eco-friendly, FSC) within each group. It showed that the socio-economic characteristics on eco-friendly respondents were higher than the others about more 1.3 times in the married rate, average age and monthly householding income.

Analysis of the Effect of Energy Prices on Investment Sentiment: Applying the Wavelet Analysis Method (에너지 가격이 투자 심리에 미치는 효과 분석: 웨이블릿 분석 방법 적용)

  • Choi, Ki-Hong;Kim, Dong-Yoon
    • Journal of Korea Port Economic Association
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    • v.37 no.2
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    • pp.119-131
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    • 2021
  • Energy is an essential element in economic activity and people's lives, an important resource used by various industries, and the financialization of commodity markets has led to the growing importance of crude oil turning into the same asset as other assets. Accordingly, studies analyzing the correlation between energy prices and investor sentiment explain that investor sentiment affects oil prices through economic factors and speculation. In this study, we wanted to analyze whether the impact of the most representative changes in oil prices affects investor decision making, affecting investor sentiment, and applying wavelet consistency analysis to determine how energy prices relate to investor sentiment. Studies show that policies should be focused on policy and market changes because energy prices differ by time scale and investment sentiment should be more influential in the long term than in the short term.

A Scoping Review for Economic Evaluation of Korean Medicine for Whiplash Associated Disorders (교통사고 상해증후군의 한의치료에 대한 경제성평가를 위한 주제범위 문헌고찰)

  • Kang, Shin-Woo;Hwang, Yun Gyeong;Hwang, Man-Suk;Lee, Hye-Yoon
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.16 no.2
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    • pp.97-105
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    • 2021
  • Objectives This study is aimed to evaluate cost-effectiveness of treatment of Korean Medicine for whiplash associated disorders (WAD) and to suggest the direction of future research. Methods We searched papers in Pubmed database to use some keywords indicating whiplash injury syndrome, treatment of Korean Medicine and cost-effectiveness. After searching, appropriate papers were selected depending on the exclusion criteria. The selected papers were analyzed in the sections of author, publication year, intervention and control groups, outcome measurement, the list including in the cost, cost-effectiveness, cost-utility and study design. Results Four studies about effect of Korean medicine and 3 studies about economic evaluation were finally included. Acupuncture was effective for balance disorder and neck pain. Economic evaluation studies used analytical decision model or cost-consequence analysis. Cost-effectiveness analysis using visual analog scale and cost-utility analysis using quality adjusted life years were performed. Initiating timing of proper management affected the consequence of treatments. Direct and indirect medical costs including supportive devices, and non-medical costs such as litigation were considered. Conclusions We conclude that studies haven't been conducted so far to evaluate the cost-effectiveness of Korean Medicine in whiplash injury syndrome. Thus, future studies are needed in this section.

Development and Validation of a Career Decision-Making Scale for Scientifically Gifted Undergraduates (과학영재 대학생을 위한 진로결정 요인 척도개발 및 타탕화)

  • Yang, Tae-Youn;Han, Ki-Soon;Park, In-Ho
    • Journal of Gifted/Talented Education
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    • v.21 no.4
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    • pp.927-943
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    • 2011
  • What are the critical factors in deciding future career to the gifted and talented students? The present study started with this question, and was to develop a career decision-making scale for scientifically gifted undergraduates. For this, literatures related to the scientifically gifted/talent and scientists' career decision-making were reviewed and examined in depth. Based on the review of the related literature, the developed scale of career decision-making was comprised of 26 items in 6 factors, such as individual aptitude & self-realization, economic aspect, work & leisure, familial influence, parents/teachers' recommendation, and experience of science activity during the school days. For the preliminary exploratory factor analysis, 153 undergraduate students who were majoring in natural sciences and engineer participated in the study. For the confirmatory factor analysis, 264 undergraduates who were awarded the presidential scholarships and 93 undergraduates who completed a university-affiliated gifted education center participated. The results of the study are as follows. The fit of measurement model was found to be $x^{2}$=645.157 (df=279, p=.00), TLI=.924, CFI= .935, RMSEA=.061, indicating most of fit indexes were acceptable. Cronbach's ${\alpha}$ in each sub-factor was quite high, .82 for individual aptitude & self-realization, .94 for economic aspect, .84 for work and leisure, .88 for familial influence, .79 for patents/ teachers' recommendation, and .79 for experience of science activity during the school days. The results of the study were discussed whether the developed scale could be used as a valid and reliable tool for measuring career decision-making factors of the scientifically gifted undergraduates in our country.

Analyzing Effective Thermal Conductivity of Rocks Using Structural Models (구조모델을 이용한 암석의 유효열전도도 분석)

  • Cha, Jang-Hwan;Koo, Min-Ho;Keehm, Young-Seuk;Lee, Young-Min
    • Economic and Environmental Geology
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    • v.44 no.2
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    • pp.171-180
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    • 2011
  • For 21 rock samples consisting of granite, sandstone and the effective thermal conductivity (TC) was measured with the LFA-447 Nanoflash, and mineralogical compositions were also determined from XRD analysis. The structural models were used to examine the effects of quartz content and the size of minerals on TC of rocks. The experimental results showed that TC of rocks was strongly related to quartz content with $R^2$ value of 0.75. Therefore, the proposed regression model can be a useful tool for an approximate estimation of TC only from quartz content. Some samples with similar values of quartz content, however, illustrated great differences in TC, presumably caused by differences in the size of minerals. An analysis from structural models showed that TC of rocks with fine-grained minerals was likely to fall in the region between Series and EMT model, and it moved up to ME and Parallel model as the size of minerals increased. This progressive change of structural models implies that change of TC depending on the size of minerals is possibly related to the scale of experiments; TC was measured from a disk sample with a thickness of 3 mm. Therefore, in case of measurements with a thin sample, TC can be overestimated as compared to the real value in the field scale. The experimental data illustrated that the scale effect was more pronounced for rocks with bigger size of minerals. Thus, it is worthwhile to remember that using a measured TC as a representative value for the real field can be misleading when applied to many geothermal problems.

The Relationship between Family Support and Ego Identity of Young People (청소년이 지각한 가족지지와 자아정체감과의 관계)

  • Kim, Chung-Nam;Kwon, Yun-Hee
    • Research in Community and Public Health Nursing
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    • v.13 no.1
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    • pp.124-136
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    • 2002
  • In the present study we have attempted to explore the relationship between family support that young people receive and the level of Ego Identity that they develop. We started the present study with the purpose of providing parish nurses with some basic data for nursing intervention for family and school nursing, as well as for community health care. We conducted the present study during the period of October 15, 2001 through November 5, 2001. The objects of this study were Inmunge High School students chosen from a school in Daejon. The subject students were selected randomly from each grade in that school. The numbers of subjects selected were 120 boys and 113 girls (total: 233). The research tool that we used to measure perceived family support received by students was one that Ga Eon Lee revised for high school students on the basis of Cobb's theory. To measure the subject students' Ego Identity level we used Bong Yon Sho's 'Ego Identity Scale', that he revised from Dignan's 'Ego Identity Scale' for Korean high school students. Data were analyzed with SPSS Win 10.0 program using statistics of frequencies, percentage, t-test, ANOVA, and Pearson correlation coefficient. The findings of the present study indicate that: 1) The mean of family support that the subject students feel that they received was 39.99 on the family support scale, and the mean of the students on the Ego Identity scale was 186.16. 2) The support that the subjects received from their own family had a statistically significant correlation with their Ego Identity (r=.93, p=.00). 3) Various factors had a significant correlation with the level of family support perceived by the subjects: the subject's grade (F=3.35, p=.04), the subject's religion (t=6.39, p=.00), the family's economic situation (F=9.14, p=.00), the birth order (F=27.61. p=.00), the father's education (F=23.17, p=.00), the mother's education (F=28.70, p=.00), parental relationship (F=2657.03, p=.00), and the structure of the family (F=-9.65. p=.00). 4) Various factors had a significant correlation with the level of the subject's Ego Identity: the subjects religion (t=6.20, p=.00), the family's economic situation (F=12.56, p=.00), the birth order (F=22.85, p=.00), the father's education (F=10.37, p=.00), the mother's education (F=20.69, p=.00), parental relationship (F=938.73. p=.00), and the structure of the family (F=-8.74, p=.00). 5) Analyzing sources of support within the family, family members whom the subjects trust most (F=3.08, p=.03) and family members to whom they talk most (F=5.85, p=.00) showed the most significant differences. Analyzing sources of support within the family that affect the level of the subjects' Ego Identity, family members whom the subjects trust most (F=3.30. p=.02) and family members to whom they talk most also showed the most significant differences.

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A Study on The Improvement of Related Regulation System for The Utility Tunnel Activation (지하공동구 활성화를 위한 관련규정 체계 개선에 관한 연구)

  • Oh, Won-Joon;Cho, Choong-Yeun;Lee, Min-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.8
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    • pp.563-571
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    • 2020
  • The purpose of a utility tunnel is to prevent repeated excavation as well as disasters and calamity. Domestic utility tunnels have been built in new town development plans. Currently, it is difficult to establish a utility tunnel due to a conflict of opinions by organization and financing. In this paper, research was conducted based on systematic procedures to suggest ways of improving the activation of utility tunnels in new cities and existing cities. First, a survey was conducted on the laws and status of utility tunnels, and problems were derived based on the review and analysis of the status. Finally, a method suggesting improvement measures to solve problems was applied. Based on the related laws and problems, the status of the development project was analyzed to select the installation scale in the utility tunnel, and the appropriate scale was reviewed through economic feasibility analysis of the installation scale under 2 million square meters. Considering the new city and the existing city, it was proposed to support administrative expenses to reduce the burden on additional installation areas and occupied institutions in a utility tunnel. In addition, improvement plans were presented for the details of the master plan for reviewing the installation regional of the utility tunnel. This paper will help officials to work smoothly when planning and installing utility tunnels in the future.

Application of an Automated Time Domain Reflectometry to Solute Transport Study at Field Scale: Experimental Methodology and Calibration of TDR (시간영역 광전자파 분석기(Automatic TDR System)를 이용한 오염물질의 거동에 관한 연구: 실험방법 및 검정)

  • Kim, Dong-Ju
    • Economic and Environmental Geology
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    • v.29 no.6
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    • pp.699-712
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    • 1996
  • Field scale experiments using an automated 144-channel TDR system were conducted which monitored the movement of solute through unsaturated loamy soils. The experiments were carried out on two different field plots of 0.54 ha to study the vertical movement of solute plume created by applying a square pulse of $CaCl_2$ as a tracer. The residence concentration was monitored at 24 locations on a transect and 5 depths per location by horizontally-positioning 50 cm long triple wire TDR probes to study the heterogeneity of solute travel times and the governing transport concept at field scale. This paper describes details of experimental methodology and calibration aspects of the TDR system. Three different calibration methods for estimation of solute concentration from TDR-measured bulk soil electrical conductivity were used for each field site. Data analysis of mean breakthrough curves (BTCs) and parameters estimated using the convection-dispersion model (CDE) and the convective-lognormal transfer function model (CLT) reveals that the automated TDR system is a viable technique to study the field scale solute transport providing a normal distribution of resident concentration in a high resolution of time series, and that calibration method does not significantly affect both the shape of BTC and the parameters related to the peak travel time. Among the calibration methods, the simple linear model (SLM), a modified version of Rhoades' model, appears to be promising in the calibration of horizontally-positioned TDR probes at field condition.

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