• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.194-194
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• 2011

보는 일반적으로 흐르는 하천을 막아 수위를 높여서 취수 용도로 사용되는 저수 시설의 역할을 한다. 그러나 홍수 시 보 구조물은 홍수류 소통의 장애물 역할을 하여 보 상류의 수위를 상승시키고, 이는 곧 보의 상류에서는 침수피해를 발생시키기도 한다. 따라서 홍수 시 보 구조물이 하천흐름을 방해하지 않도록 설계하여 보의 통수능과 안정성을 확보시키는 것은 보 설계 시에 매우 중요한 요인으로 작용한다. 본 연구에서는 낙동강 구미보를 대상으로 보 구조물에 의한 보 상류부의 통수능 및 치수안정성에 대해 분석하기 위하여 수리모형실험을 수행하였다. 가동보의 수문 운영 조건에 따른 보 상류부의 수위 변화, 빈도 홍수량에 의한 구미보 상류의 흐름특성을 유속 및 수위측정을 통하여 비교 분석하였다. 구미보의 수문 2개를 이용하여 수문 2개 개방 조건, 수문 1 개 개방, 수문 1개 폐쇄 조건, 수문 2개 폐쇄 조건으로 구분하여 실험을 진행하여 분석하였다. 연구 결과 수문폐쇄조건에서 수위가 가장 크게 나타났으며 급격히 상승하였다. 수문이 폐쇄된 2년 빈도의 홍수량조건이, 수문이 개방된 100년 빈도 홍수량조건보다 상류수심이 높게 형성되는 것을 확인할 수 있었다. 따라서 실제 계획홍수량보다 작은 유량조건일지라도 수문이 폐쇄됐을 경우에 보 상류부는 홍수범람의 위험이 더욱 커진다고 판단되었다. 가동보 수문을 개방하여 통수하는 경우에 보 상류의 수위저하 영역을 검토한 결과, 유량이 클수록 가동보에 의해 수심저하 영향을 받는 보 상류의 영역이 늘어나며, 보 상류 방향으로 거리에 따른 보 상류의 수심저하가 발생하는 거리의 관계는 유량 크기에 비례하는 것으로 나타났다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.616-624
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• 2014

Most of oven range doors are opened from top to down. Feeling of door in case of home appliances including oven ranges affects the quality of product. The major factors to evaluate the feeling quality are opening force, closing force, and bouncing effect happened when the door is opened completely. If opening and closing forces become large, consumers may have complaints. If the bouncing effect becomes large, the impact can cause the body as well as the door to damage. Opening and closing forces, and bouncing effect must be minimized to improve the feeling quality. In this study, the mechanism which improves the existed dual compressive spring and cam structure is suggested by using nonlinear cam and spring. After the nonlinear cam is designed and manufactured for the suggested mechanism, this cam is confirmed to become more superior than the existed one by applying it to the practical oven range.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.1
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• pp.55-62
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• 2006

Clinical evaluation of the Closed-view autorefractor and Open-view autorefractor was performed to examine validity and repeatability compared with subjective refraction. Measurements of refractive error were performed on 126 eyes of 65 subjects (aged $26{\pm}7.5$ years) subjectively noncycloplegic. Intersession repeatability of the Closed-view and Open-view were also assessed on all 65 subjects together with Intersession repeatability on 7 to 14 days intervals. Spherical powers and spherical equivalent values of subjective refraction and autorefractions by Closed-view and Open-view were analyzed by paired T-test. The mean spherical powers of subjective refraction, Closed-view and Open-view were determined to be $-2.125{\pm}2.155D$, $-2.146{\pm}1.907D$, $-2.117{\pm}2.121D$, respectively. The mean spherical equivalent values of subjective refraction, Closed-view and Open-view were determined to be $-2.362{\pm}2.204D$, $-2.391{\pm}1.967D$, $-2.366{\pm}2.162D$, respectively. The results showed that the refractive errors as measured by the Closed-view and Open-view were found to be similar to the subjective refraction in all components.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.9-16
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• 1997

The contingent valuation method(CVM) has been used to evaluate the economic value of nonmarket goods such as forest recreation. There are two commonly used CVM questionnaire formats: open-ended and closed-ended. This study evaluates the net economic value associated with day use downhill skiing, using CVM. A random, on-site survey of skiers in Muju, Korea generated the value estimates. In this paper a nonparametric test is introduced to find whether the difference between value estimates from open-ended and closed-ended formats are significantly different because the distributions of WTPs are non-normally distributed. The results show that the net economic benefits of a skier in Muju varies from \15,131 to \25,332. The closed-ended values were 1.15 to 1.67 times as large as the open-ended values, depending on the model specifications. In nonparametric test the mean WTPs of the open-ended and close-ended applications are significantly different. Its reason may be that closed-ended can be more reducing the incentive for strategic behavior than open-ended question. However, we cannot conclude that the closed-ended method is superior to the open-ended method.

• Informatization Policy
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• v.27 no.1
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• pp.72-91
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• 2020

In this study, we classified SNS into open and closed types, and empirically examined in which SNS activity the privacy paradox holds. The idea comes from the argument that privacy paradox may be observed differently in the open SNS, which is more vulnerable to the leakage of personal information due to public profiles, and the closed SNS, which is relatively less vulnerable by limiting the range of acquaintances, The results of the empirical analysis are as follows. First, in case of SNS usage, the privacy paradox holds in the overall SNS activities, but different conclusions are drawn according to open and closed SNS. In particular, it is found that as privacy concerns increase, individuals respond in a reasonable and desirable way to reduce SNS activity in the open SNS, which is more susceptible to infringement. Second, in the case of SNS activity intensity, (i) heavy users are more seriously aware of the probability of privacy infringement than light users, so there is a reasonable response to reducing the intensive margin with increasing privacy concerns, and (ii) this tendency is more clearly observed in open SNS, which is more vulnerable to privacy infringement. Accordingly, insisting that the privacy paradox is empirically established by observing only the overall SNS activities without distinguishing them into open and closed SNS may be interpreted as a "Fallacy of Composition."

• The Korean Journal of Financial Studies
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• v.13 no.1
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• pp.133-160
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• 2007

본 연구는 중국 뮤추얼펀드를 대상으로 폐쇄형(48개), 개방형(17개)으로 구분하여 총 65개 펀드에 대해 성과를 측정해보고, 이를 통해 중국 뮤추얼펀드가 지수대비 어떠한 성과를 보여주고 있는지를 살펴보고자 한 연구이다. 성과 평가 실증기간은 폐쇄형 펀드가 2002년 1월 4일부터 2004년 12월 31일까지 3년으로 하며 개방형 펀드가 2003년 1월 3일부터 2004년 12월 31일까지 2년으로 하였다. 실증연구방법들은 CAPM에 기반한 트레이너 모형, 샤프 모형, 젠센 모형과 장세판단능력 측정 모형인 트레이너-마주이 모형이다.

• KDI Journal of Economic Policy
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• v.34 no.4
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• pp.157-188
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• 2012

We study the relationship between the closedness of public service recruitment system and the corruption rampant between private firms and public servants. Empirically we test our claim that the closedness of public service recruitment system tends to heighten the corruption level of each country. Our results show that the closedness is positively correlated with bureaucracy corruption levels indexed by IMD, WEF, and World Bank.

• International Commerce and Information Review
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• v.14 no.2
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• pp.201-225
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• 2012

Developing new technologies and launching new products require a huge sum of money for Research and Development, and there is also market uncertainty. Comparing to advanced countries' companies, Korea's exporting companies have less investment cost in size for R&D and insufficient technology assets accumulated. Therefore, through the open innovation, they should use external technology and enhance the efficiency of the relatively little R&D investment. This paper draws the factors influencing the innovations of Korea's exporting companies, and then it analyses how each innovation influences export performance. First, innovations are devided into two; closed and open innovation. Multiple regression analysis has been done, considering influence factors of innovation such as company's characteristics factors, research's characteristics factors and products characteristics factors to be independent variables, and export performance to be a dependent variable. It shows that firm size and new products launching period have positive effects on each innovation, but research capability and research performance have positive effects only on closed innovation. And open innovation has positive effects on export performance, but closed innovation doesn't have.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.227-237
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• 2019

In terms of the concept of space in urban planning and design, the modern city approaches from the perspective that all spaces are made up of different places based on identity. In this study, we analyzed disparate image by paying attention to the difference between the individual spaces that form the city. And the physical and behavioral factors that respond to the disparate spatial images are derived through legibility measurement. As a result, the urban space in Busan has disparate images such as closure, openness, dynamic + closure, dynamic + openness, quiet space. The following are the legibility factors that make each image stronger. The elements of closure are high-density and high-rise buildings, residence, work, openness appeared as a factor of water space, walking and viewing. Dynamic & Closure is the element of industrial activity, dynamic & openness is open space, water space, swimming element, quiet space image is green space, walking, stay factor.

• Economic and Environmental Geology
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• v.52 no.4
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• pp.299-312
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• 2019

This study analyzed variation of tidal channels associated with Shihwa reclamation project for corresponding observation period based on remote sensing approaches. The project period was subdivided to developing period, closed period, and open period based on developing and management plan of Shiwa lake, and number, length, width, and direction of tidal channels for each period were analyzed using CORONA, Landsat 5 TM, Landsat 7 ETM+, and orthorectified aerial photographs. Number of tidal channels decreased from developing to opening period while $3^{rd}$ order channles did not show noticeable changes. The length of tidal channels decreased during developing to closed period, and increasing trend of $2^{nd}$ and $3^{rd}$ order channels was observed for the opening period. The average widtrh of $2^{nd}$ and $3^{rd}$ order channels decreased from developing to closed period, and increased during open period. The direction of tidal channels showed NW and NE direction in general, while the rose diagram showed deacrased frequency of NE direction and increased frequency of NW direction during the open period. These variations in tidal channels are considered to be related to changes in tidal energy environment, where stable energy environment before the project was changed to disconnection of tidal energy by closed environment, and re-connection of the energy during the open period.