• 한국지열·수열에너지학회논문집
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• 제19권2호
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• pp.1-7
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• 2023

In this study, in order to reduce the amount of infiltration generated from windows among the heat loss generated in the building, energy shutters were installed on the windows to conduct experiments on the change in internal temperature and amount of infiltration due to the pressure difference between the environmental chamber and the pressure box. As a result of the experiment, when the pressure difference was 0Pa, the initial temperature of the pressure box of window was higher than that of the pressure box of the energy shutter, but when the pressure difference occurred, the internal temperature of the pressure box of the energy shutter was higher. In addition, the amount of infiltration of the energy shutter was lower than that of the windows in all experimental conditions, and it was concluded that the reduction rate of the infiltration load (of the energy shutters) could be reduced by 53.3% compared to that of the windows.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2004년도 추계학술대회 논문집
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• pp.315-318
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• 2004

In recent days, IAQ(Indoor Air Quality) is regarded as one of the most important environmental factors as well as thermal and acoustic comfort. The purpose of this study was to estimate on effect of indoor air pollution from VOCs and formaldehyde emitted by building materials. As the results, we knew that concentration of Toluene, Xylene, Styrene and HCHO emitted from the furnitures and frame material of windows and doors are high emission factors on indoor air pollution.

• 한국실내디자인학회논문집
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• 제22권1호
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• pp.265-273
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• 2013

The purpose of this study is to analyze the state-of-the-art daylighting design among LEED(Leadership in Energy and Environmental Design) multi-family housing cases and to explore the feasibilities for their applications in domestic housing design. Occupants in multi-family houses are reported to consume more electricity power than those in single houses. That may imply the problems of daylighting design in domestic housing design for multi-family houses have better insulation system and less windows and outside walls than single houses. Therefore two systems, daylight delivery system and daylight control system, are scrutinized for daylighting design with LEED cases. The findings show when windows as a daylight delivery system are combined with overhangs, fins, louvers, fenestration materials, speciality fenestration, or interior controls as a daylight control system, the outcome goes with more energy savings and better facade design. Beside those, lightshelves as a daylight delivery system seem to have potentials in domestic multi-family houses with deep plans and less outside walls. Daylighting designs in domestic multi-family houses need to pursue available options more to achieve the integration of energy and aesthetics values.

• 상하수도학회지
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• 제29권3호
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• pp.415-425
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• 2015

Aging water pipe networks hinder efficient management of important water service indices such as revenue water and leakage ratio due to pipe breakage and malfunctioning of pipe appurtenance. In order to control leakage in water pipe networks, various methods such as the minimum night flow analysis and sound waves method have been used. However, the accuracy and efficiency of detecting water leak by these methods need to be improved due to the increase of water consumption at night. In this study the Principal Component Analysis (PCA) technique was applied to the night water flow data of 426 days collected from a water distribution system in the interval of one hour. Based on the PCA technique, computational algorithms were developed to narrow the time windows for efficient execution of leak detection job. The algorithms were programmed on computer using the MATLAB. The presented techniques are expected to contribute to the efficient management of water pipe networks by providing more effective time windows for the detection of the anomaly of pipe network such as leak or abnormal demand.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.205-210
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• 2009

Generally, the building's windows and ventilation for the purpose of mining and the vista and windows by emotional engineering design area is a growing trend. According to the flow of energy is lost from the building, will be achieved through the walls and roof and windows. Among these, the window through the loss of about 45% of the entire building is big enough to rate. In addition, the building regulation U-value Limitation of window is $3.3W/m^2$ K in southern regions, while U-value Limitation of wall is $0.35{\sim}0.58W/m^2$ K. It means that the energy loss through windows is six times more than it through wall. Therefore, the purpose of this study is to evaluate the environmental performance of the super window system by verification experiment. The results of this study are as follows; 1)Thermal performance of insulated Super Window measured as $1.44W/m^2$ $^{\circ}C$ 2)Required energy for heating was cut down about 5.3% from 266.99 $MJ/m^2$ yr to 252.85 $MJ/m^2$ yr 3)Super Window's reduction rates increased 4.1% from 31.48% to 35.58% when it is compared to normal windows. 4)Building energy efficiency rating elevated from 2nd rating to 1st rating.

• 한국태양에너지학회 논문집
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• 제30권1호
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• pp.1-6
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• 2010

Generally, the building's windows and ventilation for the purpose of mining and the vista and windows by emotional engineering design area is a growing trend.In addition, the building regulation U-value limitation of window is $3.3W/m^2{\cdot}K$ in southern regions, while U-value limitation of wall is $0.35{\sim}0.58W/m^2{\cdot}K$. It means that the energy loss through windows is six times more than it through wall. Therefore, the purpose of this study is to evaluate the environmental performance of the super window system by verification experiment. The results of this study are as follows; 1) The insulation performance of super window system is $1.44\;W/m^2^{\circ}C$ 2) Super Window compared to a normal window reduce heating energy requirements have been 5.3% 3) Compared to a normal window, Super window savings rate was 4.1% lower 4) Building energy efficiency rating was up to 1 rating from 2 rating.

• 대한산업공학회지
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• 제29권4호
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• pp.259-270
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• 2003

In order to properly design warning sounds that are affectively suitable to computer users, warning sounds used in Windows operating system were analyzed in terms of their sound properties; frequency band, spectral characteristics and physical intensity. A total of 36 warning sounds (3*4*3) were generated and tested with respect to three experimental variables. Among 178 collected affective adjectives that are related to hearing and sounds, seven representative affective adjectives were abstracted by statistical grouping techniques. In the experiment, subjective preference tests were performed for the 36 warning sounds according to the seven affective factors. From the result, the affective factors were again grouped into three major factors and the 60dB boost-type warning sounds at the low frequency band were, in general, the most preferred. followed by the 70dB cut-type sounds at the middle frequency band. These warning sounds have a characteristic of boost power spectrum below 1000Hz frequency band and received good scores on simplicity, clarity and accurateness.

• 교육시설 논문지
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• 제18권4호
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• pp.3-12
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• 2011

This study investigates interior and exterior environments and arrangement forms of school buildings from elementary to high school which were recently built in Daegu since the 7th Educational Curriculum. In addition, this study analyses how outside noise affects inside environment of schools. This study found that the noise level criteria of school facilities(such as exterior learning sites and outer walls of school buildings) adjacent to street of one side satisfiedly corresponded to the level and criteria, 65dB(A), of school health law. However, the noise level and vibration criteria of school facilities adjacent to street of two sides did not satisfiedly corresponded to the level or criteria, 65dB(A). In case of classrooms, the inner noise of educational facilities with windows closed and also close to both the street of one side and of two sides satisfiedly corresponded to the level or criteria. 55dB(A), of school health law. In spring and tall, the windows are more open them usual for ventilation, and leaving windows open can lead to noise from outside. Thus, it is urgent to prepare for this situation.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.539-545
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• 2019

Yttrium-90 is a useful therapeutic radioisotope for tumor treatment because of its high-energy-emitting beta rays. However, it has been difficult to select appropriate collimators and main energy windows for Y-90 Bremsstrahlung imaging using gamma cameras because of the broad energy spectra of Y-90. We used a Monte Carlo simulation to investigate the effects of collimator selection and energy windows on Y-90 Bremsstrahlung imaging. We considered both MELP and HE collimators. Various phantoms were employed in the simulation to determine the main energy window using primary-to-scatter ratios (PSRs). Imaging performance was evaluated using spatial resolution indices, imaging counts, scatter fractions, and contrast-to-noise ratios. Collimator choice slightly affected energy spectrum shapes and improved PSRs. The HE collimator performed better than the MELP collimator on all imaging performance indices (except for imaging count). We observed minor differences in SR and SF values for the HE collimator among the five simulated energy windows. The combination of an HE collimator and improved-PSR energy window produced the best CNR value. In conclusion, appropriate collimator selection is an important component of Bremsstrahlung Y-90 photon imaging and main energy window determination. We found HE collimators to be more appropriate for improving the imaging performance of Bremsstrahlung Y-90 photons.

• Wind and Structures
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• 제28권6호
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• pp.389-404
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• 2019

In coastal regions, it is common to witness significant damages on low-rise buildings caused by hurricanes and other extreme wind events. These damages start at high pressure zones or weak building components, and then cascade to other building parts. The state-of-the-art in experimental and numerical aerodynamic load evaluation is to assume buildings with intact envelopes where wind acts only on the external walls and correct for internal pressure through separate aerodynamic studies. This approach fails to explain the effect of openings on (i) the external pressure, (ii) internal partition walls; and (iii) the load sharing between internal and external walls. During extreme events, non-structural components (e.g., windows, doors or rooftiles) could fail allowing the wind flow to enter the building, which can subject the internal walls to lateral loads that potentially can exceed their load capacities. Internal walls are typically designed for lower capacities compared to external walls. In the present work, an anticipated damage development scenario is modelled for a four-story building with a stepped gable roof. LES is used to examine the change in the internal and external wind flows for different level of assumed damages (starting from an intact building up to a case with failure in most windows and doors are observed). This study demonstrates that damages in non-structural components can increase the wind risk on the structural elements due to changes in the loading patterns. It also highlights the load sharing mechanisms in low rise buildings.