• KIEAE Journal
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• v.9 no.1
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• pp.69-76
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• 2009

The use of natural light can improve the quality of indoor environment and also occupants health. In recent years, with an increasing awareness of sustainable development, various innovative methods of integrating daylight into the building have been developed. One such device is the light pipe system. The light pipes are innovative daylighting system that allow the transmission of daylight into the hard-to-reach indoor space. The system consist of mainly three parts. First, a top collector which is mounted on the outside of the roof and gathers skylight and sunlight. Second, light-reflective tube which is coated with highly reflective mirror finish material to transmit the daylight into the diffuser. Third, a diffuser which is installed on the ceiling in the room and spread the daylight into the room. Light pipes have been widely used and researched in many countries such as Australia, America, Canada and Britain. However, despite the significant daylight potential, little work have been carried out in Korea compare to the other countries. In this study, recent lighting technology and application of light pipe system in both Korea and other countries have been compared. For the results, the benefits of each light pipe system and suitable application in Korea is also discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.13-22
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• 2005

This research aimed to generate two points of daylighting application as follows: 1) providing daylight performance data with a variety of glazing materials for a large window and 2) designing and evaluating an experimental type of differentiated window. For this purpose, we compared the daylight and distribution performance of new defined type of window configuration to the conventional window counterpart with a variety of glazing materials. The comparison was made for a deep, south-facing perimeter zone with large window, without any interior obstruction. The conventional window is the base single homogeneous glass pane, where as the differentiated window uses of two different glazings; an upper daylight glazing with high visible transmission and lower view window with lower transmittal glass. The daylight performance data was translated into a ratio between outdoor illuminance and the interiors. The simulated analysis of the conventional window indicates that the interior light levels have been changed proportionally dependent on the transmittance of the applied glass. The comparison of daylight distribution analysis showed that the differentiated window has lots of photometric advantage by the optical function of upper daylight window. In particular, the contribution of higher daylight window into deep rear space must be stressed for daylighting application.

• Journal of Korean Association for Spatial Structures
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• v.9 no.2
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• pp.77-82
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• 2009

ETFE is the abbreviation of Ethlene Tetra Fluoro Ethlene, a sort of colorless and transparent granules. The advantage of ETFE film has chemical resistance, anti-stick property, very lightly material. The thickness of ETFE film is used to from 50 ${\mu}m$ to 300 ${\mu}m$ and have superior ability of daylight transmission and elongation, while the strength is lower than of fabric membrane. The tensile strength of ETFE film changes from 40Mpa to 60Mpa and the tensile strain at break can get to about 300-400%. The mechanical characteristic test of ETFE film is described in this paper. The tensile strain at break, the tensile strength and the stress-strain curve are obtained from the test. And then it was analyzed stress-strain characteristic by temperature and mechanical characteristic by cycling load.

• Journal of Practical Engineering Education
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• v.10 no.2
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• pp.81-87
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• 2018

During the major sections of the network, Software-defined network control technology for the network area corresponding to the transmission network is becoming a change in network-controlled environments utilizing network operation and provisioning across the network industry. Currently development is underway along with the deployment of PTN equipment and configuration for provisioning is being phased out. It is actively introducing establishment of SDN-based control system while constructing provisioning of PTN equipment from actual commercial network. Therefore, in this thesis, we are going to look at the contents and trends of SDN systems in packet-based transmission networks based on PTN and use them in research on OpenDaylight, an open source for configuring SDN. It then Network Operator will study the software defined control techniques for operational education.

• Journal of the Korean Solar Energy Society
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• v.40 no.1
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• pp.35-47
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• 2020

Due to the large window area, the lighting environment of the educational space between the window and deep part of the room is not uniformly illuminated, and the phenomenon of glare is severe. For this reason, the daylight performance of DSC-BIPV windows was analyzed in order to improve the natural lighting in the educational sector. The method derives the correlation with natural lighting by measurement and simulation. Dynamic simulation confirmed that the average illuminance of the target space was higher at later than the early afternoon. The performance of natural lighting at 40% and 30% transmission of DSC has the effect of significantly reducing the amount of excess light in existing windows. Nevertheless, the actual average illuminance in all seasons corresponds to the standard illuminance of the educational facility, 300 Lux. In addition, the uniformity is also seen through the skylight illuminance ratio.

• Journal of IKEEE
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• v.23 no.4
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• pp.1448-1456
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• 2019

In this study, when applying LED light sources within a single-span glass greenhouse for growing crops, the illumination simulation was performed on the ceiling and side of the glass greenhouse to determine the selective placement and effective light transmission of Si series solar cells and dye-sensitive solar cells (DSSC) for supplying LED power source. In addition, energy saving effects of glass greenhouses were analyzed for optimum lighting control when both daylight and LED light sources are considered in glass greenhouses.

• Journal of Korean Association for Spatial Structures
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• v.10 no.1
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• pp.51-58
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• 2010

ETFE is the abbreviation of Ethylen Tetra Fluoro Etylene, a sort of colorless and transparent granules. The advantage ETFE film has daylight transmission and chemical the resistance and The thickness of ETFE film is used to from $50{\mu}m$ to $300{\mu}m$ and tensile strength of ETFE film changes from 40MPa to 60MPa and the tensile strain at break can get to about 300-400%. In this paper, ETFE film carried out the tensile proprieties, such as the tensile strain at break, the tensile strength are examined.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.814-819
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• 2005

There is growing consciousness of the environmental performance of buildings in Hong Kong. The Buildings Department, the Lands Department and the Planning Department of the Hong Kong Government issued the first of a series of joint practice notes [1] to promote the construction of green and innovative buildings. Green features are architectural features used to mitigate migration of noise and various air-borne pollutants and to moderate the transport of heat, air and transmission of daylight from outside to indoor environment in an advantageous way. This joint practice note sets out the incentives to encourage the industry in Hong Kong to incorporate the use of green features in building development. The use of green features in building design not only improves the environmental quality, but also reduces the consumption of non-renewable energy used in active control of indoor environment. Larger window openings in the walls of a building may provide better natural ventilation. However, it also increases the penetration of direct solar radiation into indoor environment. The use of wing wall, one of the green features, is an alternative to create effective natural ventilation. This paper therefore presents a preliminary numerical study of its ventilation performance using Computational Fluid Dynamics (CFD). The numerical results will be compared with the results of the wind tunnel experiments of Givoni.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.11
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• pp.445-452
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• 2017

Electric pole is a supporting beam used for power transmission/distribution which accelerometer are used for measuring a external force. The meteorological condition has various effects on the external forces of electric pole. One of them is the elasticity change of the aerial wire. It is very important to perform modelling. The acceleration sensor is converted into a pitch and a roll angle. The meteorological condition has a high correlation between variables, and selecting significant explanatory variables for modeling may result in the problem of over-fitting. We constructed high deviance explained model considering multicollinearity using the Generalized Additive Model which is one of the machine learning methods. As a result of the Variation Inflation Factor Test, we selected and fitted the significant variable as temperature, precipitation, wind speed, wind direction, air pressure, dewpoint, hours of daylight and cloud cover. It was noted that the Hours of daylight, cloud cover and air pressure has high explained value in explonatory variable. The average coefficient of determination (R-Squared) of the Generalized Additive Model was 0.69. The constructed model can help to predict the influence on the external forces of electric pole, and contribute to the purpose of securing safety on utility pole.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.196-202
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• 2008

Effective climate protection is a most important tasks of our time. The BIPV is one of the most interesting and promisingly possibilities of an active use of solar energy at the building. In this study it was analyzed by the case study the function of the requirement of the BIPV-module as building material and this architectural characteristic according to the kind of the module. Therefore the goal of this study is to get securing the application information of BIPV as windowpane. BIPV modules are manufactured in the form of G/G. In the case of the crystal type the Transparent and the light Transmission is to be adjusted by the spacer attitude of the cell. Although this type could not be optimal for light effect of indoors because of the inequality of shade, the moving shade play makes a dramatic Roomimage by the run of sun. The application of this type would be for canopy, window or roof in the corridor or resounds. With amorphous the type it is to be manufactured simply largely laminar, and thus that will shorten building process. There is a relatively good economy to use and to the window system easily. After the production technology is easy the transparency of the modules to adjust, and the module shows to a high degree constant characteristics of light permeability and transparency. Without mottle of module shade is good the use for the window or roof glazing of office, library, classroom, etc. to adapt. The BIPV modules took generally speaking a function as building material to the daylight use, shading, isolation and also to the sight. That means that BIPV modules have as multifunctional system to sustainable architecture good successes and they are at the same time as Design element for architecture effectively.