• 제목/요약/키워드: Economic Scale

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Ordinal Optimization Theory Based Planning for Clustered Wind Farms Considering the Capacity Credit

  • Wang, Yi;Zhang, Ning;Kang, Chongqing;Xu, Qianyao;Li, Hui;Xiao, Jinyu;Wang, Zhidong;Shi, Rui;Wang, Shuai
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.1930-1939
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    • 2015
  • Wind power planning aims to locate and size wind farms optimally. Traditionally, wind power planners tend to choose the wind farms with the richest wind resources to maximize the energy benefit. However, the capacity benefit of wind power should also be considered in large-scale clustered wind farm planning because the correlation among the wind farms exerts an obvious influence on the capacity benefit brought about by the combined wind power. This paper proposes a planning model considering both the energy and the capacity benefit of the wind farms. The capacity benefit is evaluated by the wind power capacity credit. The Ordinal Optimization (OO) Theory, capable of handling problems with non-analytical forms, is applied to address the model. To verify the feasibility and advantages of the model, the proposed model is compared with a widely used genetic algorithm (GA) via a modified IEEE RTS-79 system and the real world case of Ningxia, China. The results show that the diversity of the wind farm enhances the capacity credit of wind power.

Effect of Sociodemographic Factors, Cancer, Psychiatric Disorder on Suicide: Gender and Age-specific Patterns (인구사회적 요인, 암, 일부 전신질환 등이 자살에 미치는 영향: 성별, 연령별 분석)

  • Park, Jae-Young;Chae, Yoo-Mi;Jung, Sang-Hyuk;Moon, Ki-Tae
    • Journal of Preventive Medicine and Public Health
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    • v.41 no.1
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    • pp.51-60
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    • 2008
  • Objectives : We examined the effect of sociodemographic factors, cancer, and psychiatric disorders on suicide by gender and age-specific patterns in South Korea. Methods : The study is a case-control study. Claim data was obtained from the national health insurance database and national death registration database. The number of people who committed suicide was 11,523, which was matched with a control group consisting of ten times as many people at 115,230 selected from the national health insurance and medical aids beneficiaries. The medical utilization of the case group was one year before death and that of the control group was from July 1,2003 to June 30, 2004. Four variables-address, economic status, presence of a psychiatric disease, and cancer-were used in multiple logistic regression analyses. Results : Living in cities or in rural areas showed a greater risk for suicide than living in a metropolitan city. Low economic status, the presence of a psychiatric disorder, and cancer were also statistically meaningful risk factors for suicide. The three major psychiatric diseases, schizophrenia, alcohol abuse, and bipolar disorder, were meaningful in all age groups, but the scale of the odds ratio differed by the age group. Only the psychiatric disorder variable was meaningful in the adolescent group, whereas a psychiatric disorder and economic status were meaningful for the young adult group, and all variables were meaningful for the middle-aged group. A psychiatric disorder and cancer were meaningful in the elderly group, economic status was meaningful for male subjects, and address was meaningful for female subjects. Conclusions : Factors such as living in city or rural areas, low economic status, the presence of a psychiatric disorder, and cancer were statistically meaningful risk factors in suicide. These factors also differed by age group. Therefore, policymakers should establish policies for suicide prevention that are relevant for each age group.

A Study on the Economic Feasibility of Polyculture (복합양식의 경제적 실현가능성에 관한 연구)

  • 이승우;유정곤;황진욱
    • The Journal of Fisheries Business Administration
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    • v.25 no.2
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    • pp.115-145
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    • 1994
  • The objetives of this study are to find the economic feasibility of the polyculture and to give the economic information of the polyculture for aquaculture fishermen. The polyculture is defined as the rearing of several species together to make more efficient use of the growing space and the total ground environment. The economic feasibility analysis in the polyculture involves the profitability, the productivity, and the risk reduction effect. The results of the economic feasibility analysis in the polyculture are as follows; First, in the profitability analysis, the solid utilization of ground in the polyculture is more profitable than the monoculture. The profitability owing to the plane utilization of the ground in the polyculture is positioned between those of the monoculture of each speices. Second, in the productivity analysis, oyster and sea squirt are diminishing returns to scale. Third, the variation on the average rate of return in the polyculture products is smaller than that of the monoculture. Finally, the result of comparison between the polyculture and the monoculture shows that the polyculture in coastal area is more profitable and more efficient than the monoculture. Most of cultivating species are selective in their diet Thus, stocking different kinds of cultivating species will efficiently utilize space and food It seems that polyculture is more appropriate for those species that live in different ecological niches. We think that the production per unit of ground can be increased, and the fixed cost per unit of output be reduced, so the polyculture is more profitable than the monoculture. Based on the above results, we concludes that the polyculture is economically feasible when profitability and productivity are increased and simultaneously the variation of average rate of return in the polyculture is smaller than that of the monoculture.

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Impact of Tourism Development on the Regional Economy : Adopting the Tourist Money Flow Analysis (관광개발의 지역경제 파급효과: $\mathbb{\ulcorner}$관광지출흐름분석$\mathbb{\lrcorner}$ 방법론의 모색)

  • 주성재
    • Journal of the Economic Geographical Society of Korea
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    • v.1 no.1
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    • pp.113-135
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    • 1998
  • There have been several research methodologies to measure the impacts of tourism development on the regional economy, which include input-output analysis, income multiplier analysis, labor creation effect analysis, etc. Most of these are based on regional economic indices using secondary data for medium to large regional units. This study tests the possibility of adopting tourist money now analysis, which encompasses a series of money flows beginning with tourists'payment for room, board and shopping, followed by tourist companies'expenditure for material and service purchase, wage, utilities, rent, tax and so forth, and by tourism workers'expenses for living and savings. This method makes it possible to reveal the amount and geographical extent of tourist money flow and draws some meaningful regional economic figures. Case studies of three torist developing areas show that it is utilized for impact studies for small scale areas.

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The Change of Work Careers in Youth Cohort pre and post-the Economic Crisis- (외환위기 전후 청년 코호트의 노동경력 비교)

  • Moon, Hey Jin
    • Korean Journal of Social Welfare
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    • v.65 no.1
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    • pp.201-226
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    • 2013
  • This study aims to identify changes in early work career of youth cohort entering the labor market pre and post-the economic crisis and compare career pathway types of different cohorts. Labor market experiences of youth cohort were constructed by sequencing the number of organizations, kinds of jobs, the scale of the business, and type of employment. In addition, a holistic sequence was created by including complementary factors. In this sense, the labor market experience in this study was conceptualized as a process involving continuous sequences and hierarchical and orderly changes which differs from a simple job mobility. Sequence analysis involving Optimal Matching method was conducted to examine whether such cohort-differences in labor market experiences were related to differences in distribution of career pathway types. The result showed that the post-economic crisis cohort had a relatively higher likelihood of falling into the non-employment type, unemployment type, non-corporate employment type, irregular employment type, and mobile employment type. These findings provide empirical evidence supporting the hypothesis that the employment precariousness of cohort has exacerbated after the economic crisis.

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The Development and Prospect for Economic Geography in a Knowledge-Information-Based Society (지식정보사회의 경제지리학 발전과 과제)

  • Han, Ju-Seong
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.3
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    • pp.273-301
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    • 2008
  • This study aims not only to examine the globalization, imformationization, and networking as background of knowledge-information-based society, but also to clarify the research fields of 'geography of knowledge' and further research themes for economic geography in a knowledge-information-based society. As a result of globalization, the degree of regional disparity, which had decreased with neoliberal policy in Europe and America in 1980's, has increased in early development states such as China and Eastern European countries. In opposition to the globalization that has led to increasing regional disparities at a global scale, many scholars argue that grassroots globalization or globalization from below is needed. Based on a pessimistic view on globalization, many maintain that unequal access to information has enlarged the gap between rich and poor. They also argue that the study of the geography of poverty is crucial in oder to solve the problem of bipolization. According to the world system theory, spatial grasp of commodity chains, actors' diversities, flows towards innovation in learning knowledges, and geographical, organizational, and institutional proximities are intertwined. Because these elements make significant influences each other in social networks, the interrelationships among those elements should be carefully considered. A 'geography of knowledge' deals with manufacturing, finance and service, media, cultural, and creative industries. Former researches in economic geography have tended to deal with those industries separately without attempting to make meaningful linkages among discussions on those industries.

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Analysis on Costs Structure and Economic Limitation at Domestic Short Sea Shipping of Container (컨테이너 연안운송의 비용구조와 경제적 제약 분석)

  • Park, Yong-An;Choi, Ki-Young
    • Journal of Korea Port Economic Association
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    • v.25 no.3
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    • pp.321-338
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    • 2009
  • This study looks at the reasons behind the termination of container transportation between Busan and Incheon in terms of costs structure, the division of profit, and the economic limitation faced in the domestic shipping market. The operation costs have been examined in relation to the components of logistic system of container shipping and the cost function has been estimated. The distribution proportion of operation revenue has been also investigated, considering the different components of logistics activities. In addition, the average revenue of container vessels of 144TEU and 215TEU has been calculated. Economic limitation can be analysed through the optimisation behaviour of shipping companies which tries to maximize profit or minimize loss. In conclusion, domestic short sea shipping can get the economy of scale only by transporting vessels' maximum capacity. It is also vulnerable to trucking market's fluctuation. Without the subsidy for operation, the liner in domestic short sea shipping will stop the service in order to minimize the loss.

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Attractiveness Valuation of Phenomenal Architectural Aesthetic by Mixing the Fuzzy Logic with Contingent Valuation - Availing the Use Fares of Facility within Nodle Islet Cultural Center as Valuation Scale - (퍼지논리와 가상가치법 혼합을 통한 현상적 건축미의 매력가치 - 노들섬 문화센터 시설이용료를 가치 척도로 -)

  • Lee, Dong-Joo;Ko, Eun-Hyung
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.5
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    • pp.3-10
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    • 2018
  • The purpose of this study is to estimate the attractiveness value according to the preference level on architectural aesthetic. This research starts from the concept that aesthetic is phenomenon and from the viewpoint of 'attraction value' which affects goods. Interactive internet surveys were conducted for 500 citizens of Seoul metropolitan city who are potential users of the Nodle Islet Cultural Center. Based on the scenarios and questionnaires with fuzzy models, we have examined the evaluation of architectural aesthetic and monetary willing-to-payment, and estimated the economic value by preference level of architectural aesthetic through linear regression analysis. The main results of the study are as follows: First, the economic value of the Nodle Islet Cultural Center was estimated at ?15,683.43/person. Residents of Seoul metropolitan city were willing to accept the increase in the above-mentioned amount of the facility fares when their preferred works (average 86.81 points) were constructed. (P <0/05) Second, it is confirmed that the economic value increases dramatically as the preference level of architectural aesthetic increases. Third, it is presumed that the infinite valuation of architectural aesthetic and the problem of free riding coexist in the estimation of economic valuation of architectural aesthetic for public buildings. Fourth, by mixing the fuzzy logic with contingent valuation method, starting point bias and no response biases that happened in contingent valuation could be disappeared. bias elimination must be considered seriously because another bias could be happened in full process of the research. The results of this study will serve as a basis for spreading architectural aesthetic value-oriented research from the vague and obscure aesthetic-centered discussion on the existing architectural aesthetic. In addition, it will be an opportunity to draw institutional application and utilization strategy of architectural aesthetic through architectural aesthetic value research.

A comparative study of Water Public-Private partnership characteristics in Guangdong and Shandong provinces in China

  • Jihye Oh
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.182-182
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    • 2023
  • Since China adopted Public Private Partnerships (PPPs) in the 1980s, China has relied on water PPPs to expand appropriate water facilities.. According to the World Bank data from 1994 to 2020, the top five provinces hosted over 40 percent of total PPPs, with four of them located in the Huadong area and one in the Henan area. A vast gap exists between the group attracting the most PPPs and the group hosting the least. This study explores Guangdong and Shandong provinces, which have led most PPPs in China. Coincidently, these areas are also famous for the typical areas to show the Chinese economic policy after the open-door policy. They have achieved economic development and rapid urbanization rates based on the large scale of Foreign Direct Investment inflow and export-oriented manufacturing industry, as well as their active participation in PPPs over the last thirty years. An economic approach can provide valuable insights into the development of water infrastructure. Adequate urban infrastructure has been shown to impact local economic development positively. Water infrastructure also provides a basic and sustainable environment for economic activities by satisfying more water usage, improving the efficiency of the water supply, and reducing water pollution caused by industrial activities. However, it remains only partially understood without inclusive research on the issues related to water resources in each province. For instance, existing studies have been limited to explaining slightly different patterns of water PPPs between Guangdong and Shandong at the beginning of the PPP era. This study aims to elucidate the development pattern of water PPPs in each province from multi-dimensional aspects. Therefore, the study will help understand why China boosted the development of the private water market.

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Analyses on Techno-economic Aspects and Green Hydrogen Production Capability of MW-scale Low-temperature Water Electrolyzers in Jeju Island, South Korea (제주도 MW급 저온 수전해 수소 생산 시스템의 그린수소 생산 능력 및 경제성 분석 )

  • KOSAN ROH;YEONGJIN KIM;HONGJUN JEON;WOOHYUN KIM;HEESANG KO;KYOUNG SOO KANG;SEONG UK JEONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.3
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    • pp.235-245
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    • 2023
  • Techno-economic analyses on a 5-MW water electrolysis system for hydrogen production, operated in Jeju Island where the portion of renewable energy in the power grid is the highest in Korea, have been performed. The cost of hydrogen production and the economic feasibility of the hydrogen production system have been mainly analyzed based on the levelized-cost-of-hydrogen model. The effects of carbon emission trading and renewable power purchase method have been considered to reduce the cost of green hydrogen production in the case studies. This economic analysis model is expected to be used to derive a business model for green hydrogen production.