• Title/Summary/Keyword: Free-riding

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Numerical Investigation of Hydraulic Jump in a Spillway (여수로에서 도수 수치해석 연구)

  • Paik, Joongcheol;Ryu, Yong Uk;Lee, Nam-Ju
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.66-66
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    • 2017
  • Hydraulic jump is typically designed to occur over low-haed dam spillways and weirs in the river. An important engineering application of the hydraulic jump is to dissipate the intense kinetic energy of the flows over such hydraulic structures. Turbulent flow and roller-like vortex riding up the free sureface of the jump cause most of the energy dissipation. We carry out a high resolution three-dimensional numerical simulations of a submerged hydraulic jump in a spillway and compare numerical results with a laboratory measurement obtained by the PIV. The numerical results further show the dynamic behavoirs of the inner and outer layers of the submerged wall-jet and the recirculating roller of the hydraulic jump.

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How Chinese Online Media Users Respond to Carbon Neutrality: A Quantitative Textual Analysis of Comments on Bilibili, a Chinese Video Sharing Platform

  • Zha Yiru
    • Asian Journal for Public Opinion Research
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    • v.11 no.2
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    • pp.145-162
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    • 2023
  • This research investigates how users of Bilibili, a video sharing website based in China have responded to carbon neutrality. By conducting quantitative textual analyses on 3,311 comments on Bilibili using LDA topic extraction and content statistics, this research discovers that: (1) Bilibili users have assigned more weight to geopolitical topics (56.3%) than energy (22.0%) and environmental topics (21.7%). (2) When assessing carbon neutrality, Bilibili users considered geopolitical (53.8%) and energy factors (15.8%) more heavily than factors related to the class (9.2%), economy (8.9%), environment (8.7%), and definition (3.6%). (3) More Bilibili users had negative (64.6%) attitudes towards carbon neutrality, with only a small portion of them expressing positive (26.8%) and neutral (8.6%) attitudes. (4) Negative attitudes towards carbon neutrality were mainly driven by geopolitical concerns about the West's approach to China, other countries' free-riding on China's efforts and the West's manipulation of rules, doubts about the feasibility of energy transition and suspicion of capitalists exploiting consumers through this concept. This research highlights the geopolitical concerns behind the environmental attitudes of Chinese people, deepening our understanding to psychological constructs and crisis sensitivity of Chinese people towards environmental issues.

Transport Efficiency Analysis of the Lines of Urban Railway using Data Envelopment Analysis (DEA를 활용한 도시철도 노선별 수송효율성 분석)

  • Kim, Soo Hyun;Jung, Hun Young;Lee, Won Gyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.605-616
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    • 2014
  • The purpose of this study is to analyze transport efficiency of each of the 17 urban railway lines being operated by national public agencies using Data Envelopment Analysis (DEA) and to seek strategies for improving efficiency of the urban railway system. The study identified the economies of scale derived from these values of efficiency and examined the effects on cost for free ride loss and profit of transport by the fare system as the external factor. At the time, Transport profits are estimated by two production factors such as the number of vehicles and service frequency derived from multiple regression. Finally, the measures to improve the efficiency were presented in terms of profitability in the national urban railway line by applying the values of efficiency derived from DEA to multidimensional scaling (MDS).

A Study on Universal Design Guideline of the Urban Railway Station: Platform (도시철도 역사 승강장의 유니버설 디자인 기준에 관한 연구)

  • Kang, Byoung Keun;Kim, Sang Woon;Shin, Dong Hong;Lee, Joo Hyung;Lee, Ju Yeon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.21 no.2
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    • pp.35-43
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    • 2015
  • Purpose: A large number of the mobility impaired have increasingly used the railway station, so the application of UD(Universal Design) on urban railway station has been interested. However, the current criteria used in domestic areas have concerned about the effective administration of railway station facilities rather than the needs of he mobility impaired. Of diverse facilities in railway station, the platform is considered as an important space due to many transportation users' riding or transfer in railway stations. Therefore, this study aims to explore the detailed criteria in adapting ideas from UD to platform within railway station. Methods: This study explores the criteria by evaluating findings from previous studies. First, all criteria related to platform in domestic and foreign areas are taken together and analyzed, and appropriate criteria first are established. Based on these, the current situation of platform facilities in railway station is evaluated. Then, the detailed criteria applicable to railway station platform are concluded, by reviewing types of the mobility impaired and principles of UD. Result: Findings from this study are as follows. First, the current criteria applied to railway station platforms lack ideas of UD, while the criteria used in foreign countries adequately reflect the ideas of UD on railway station platforms; therefore, the better criteria applicable to platform facilities in domestic railway station are necessary. Second, standard criteria used in domestic areas with newly additional criteria suggest that platform facilities should be established according to those criteria. Taken together, the better platform facilities should be provided to railway users through the application of UD to railway station platforms. Implications: For the future users in railway station platforms, the additional research on criteria of UD as well as diverse types of spaces within railway stations should have been continued.

Information Externality, Bank Structure, and Economy (경제발전 및 정보의 외부성에 따른 최적 은행구조에 대한 고찰)

  • Doh, Bo-Eun
    • KDI Journal of Economic Policy
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    • v.27 no.1
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    • pp.39-79
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    • 2005
  • This paper addresses the question of whether a monopolistic banking system can lead to a higher steady state level of capital stock. Information externality has enhanced as the advance of the financial system such as the establishment of the credit bureau system, networking, etc. Hence this paper aims to analyze the effects of both information externality and economic development on the determination of the optimal banking market structure. This paper shows that the presence of information externality together with asymmetric information would explain how a monopoly bank leads to a higher steady state level of capital stock. It also shows that not only under-developed countries but industrialized countries may also benefit from a concentrated banking system. This analysis provides an alternative explanation of the recent deregulation and resulting trends in mergers and acquisitions. This also provides a theoretical foundation to support governments' policy changes toward promoting merger and acquisition activities.

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The Perceptions of Science Teachers Regarding Science Research Ethics Education (초중등 과학교사들의 과학연구윤리교육에 대한 인식)

  • Kim, Seong-Deok;Kim, Hyo-Nam
    • Journal of Korean Elementary Science Education
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    • v.32 no.4
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    • pp.393-403
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    • 2013
  • The purpose of this study was to investigate the perception of school teachers in science research ethics and perception of science research ethics education. A survey was administered for this study and a total 167 elementary and secondary teachers studying in K University graduate school participated. The survey was organized to examine participants' 1) science research ethics awareness, 2) status of science research ethics education, and 3) needs for science research ethics education, and 4) the perception of the direction of the science research ethics education in school. Each item was responded using either 1 to 5 Likert type scale, multiple choices questionnaires. The results were as follows: both of elementary and secondary school teachers showed above average interest in science research ethics and secondary school teachers showed significantly higher interest than elementary school teachers(p<0.05). In degree of awareness of science research ethics, plagiarism (M=3.98) was the highest, followed by free-riding(M=3.78), the scientist's social responsibility(M=3.71), and forge(M=3.61). In response science research ethics problem occurs in science education activities more than the average(M=3.39). Teacher's response on the teaching of science research ethics ranges from 3.02 to 4.47, but each science research ethics elements was showed a large deviation. Elementary and secondary school teachers responded that science research ethics education needed(M=4.34). Science research ethics education should be included in the school curriculum. Eighty-five percent of the teachers responded that the science research ethics education should be started from elementary school. 'Discussion-type classes with examples' was preferred as an effective teaching. And teachers needed 'instructional materials' and 'teachers training' for science research ethics education.

A Study on Child Rearing in the High Officials' Collection of Works During the Late Period of the Goryo Dynasty: Focusing on the Conception of Children and their Activities in Everyday Lives(I) (고려 말 신흥사대부의 개인문집에 나타난 아동양육 (I) - 아동기 개념화와 일상생활을 중심으로 -)

  • Shin, Yang-Jai
    • Journal of the Korean Home Economics Association
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    • v.43 no.12 s.214
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    • pp.79-96
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    • 2005
  • The purpose of this study is to explore the conceptions of children and their activities in everyday lives during the late period of the Goryo Dynasty. The historical method was used and the materials for analysis were the literatures written from the late thirteenth century to the fourteenth century in the Goryo Dynasty, such as 'the Ikjaijip'(익재집), 'Mokeunjip'(목은집), 'Yangchonjip'(양촌집). According to the results, the perspective on the nature of a chad was that children were inherently good with the true character which was given from natural laws and that each child was born with different natural endowment. Also, the notions on child development were that the infancy was a pure and perfect period which us not contaminated by temperament and worldly desires, instead of the developmental model that childhood is as a stage and the child must develop from the state of incompetence to the state of maturity. In addition, there were the principles for development that were keeping the innate ideal state and fostering it from the earliest time as infants were born with innate ideal state or ability. The concepts of children's characteristics were considered that they were inclined to make much noise and movement, but to have the plain and straightforward expressions and consistency in their feelings and everyday activities. And intelligent abilities for learning were often considered as desirable traits. In everyday lives, children did the household chores such as caring for livestock and silkworms or embroidering. Among their games were exploring activities, free plays using natural materials, pretend-plays, bamboo-stilts riding, and Yutnori.

The Effects of Red-ginseng Intaking on Free Radical Produced During Aerobic Exercise in the Elderly (홍삼복용이 노인들의 유산소 운동시 발생된 활성산소에 미치는 영향)

  • Choi, Jong-Hwan;Kim, Young-Soo;Lee, Kyu-Moon;Kim, Hyeon-Ju
    • Journal of Ginseng Research
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    • v.28 no.1
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    • pp.27-32
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    • 2004
  • This study was performed to investigate the effect of 12 weeks red-ginseng intaking on MDA(malondialdehyde) produced during aerobic exercise in the young and elderly women. Sixteen volunteers agreed to participate and were placed in 2 groups: in the young(20-25 yrs), red-ginseng intake group(n=8), in the elderly(60-69 yrs), red-ginseng intaking group(n=8). The subjects who joined this study were asked to take 2.7g of red-ginseng powder capsule per day before the meal for 12 weeks(3 times/day). MDA(from blood samples) were collected at rest, just after the submaximal exercise, and 30 minutes after the exercise(cycle ergometer riding) at the beginning and the end of the 12-weeks program. After 12 weeks of red-ginseng intaking, young and elderly groups showed the decreased MDA significantly at rest(41.57%, 28.59%), just after the exercise(45.96%, 40.74%). and 30 minutes after the exercise(37.37%, 32.68%). These results indicate that red-ginseng intaking, as an antioxidant, may be useful for removing MDA produced during aerobic exercise in the elderly.

A Study on the Equivalence Requirement of WTO Retaliation (WTO 보복조치의 동등요건에 관한 연구)

  • Kang, Soo-Mi
    • Journal of Arbitration Studies
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    • v.23 no.2
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    • pp.81-113
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    • 2013
  • The World Trade Organization (WTO) offers remedies for non-compliance by the introduction of compensation or retaliation in the Dispute Settlement Understanding (DSU). There are no the provisions under the WTO DSU and it seems unclear what retaliation is attempting to achieve. Therefore, it is unclear whether the goal of WTO retaliation is to induce compliance or to restore the balance between the rights and the obligations of WTO members. It has been claimed the WTO has a strong dispute settlement system by providing retaliation when the recommendations and rulings of Dispute Settlement Body (DSB) are not complied with. But this seems to be inadequate to bring about effective and timely compliance. Especially there is a problem with free riding by a violating member because the level of retaliation is determined from the expiration of a reasonable period of time, providing an incentive to delay compliance. Also the level of the suspension of concessions or other obligations authorized by the DSB is equivalent to the level of nullification or impairment, according to DSU Article 22.4. However, if the member concerned objections to the level of the suspension proposed, the matter shall be referred to arbitration. The arbitrator shall not examine the nature of the suspension of concessions or other obligations to be suspended but shall determine whether the level of such suspension is equivalent to the nullification or impairment. The arbitrator makes an assessment standard of equivalence by comparing the suspension of concessions or other obligations and the nullification or impairment calculated in terms of the amount of trade. But it is necessary that other standards replace the quantitative standards when the level of the nullification or impairment cannot be quantified by concrete damages.

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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.