• 에너지공학
• /
• 제22권2호
• /
• pp.83-89
• /
• 2013

에너지사용은 우리생활과 밀접한 관계성을 유지하고 있다. 사계절이 뚜렷한 우리나라로서는 건물분야에 냉,난방이 필수품처럼 여겨지는 세대에 살고있어 에너지 사용과 유지에 새로운 트렌드를 요구하고 있다. 이에따라 정부는 신축 및 기존건축물의 에너지효율 개선을 위해서 단열기준을 지속적으로 강화하여 에너지절감을 꾀하고 있다. 공동주택의 에너지효율 분석중 가장 중요한 요소가 열관류율이며 그값은 외피면적비에 대한 창면적비에 따라 난방에너지 요구량이 큰차이를 보여주고 있다. 그러므로 지속적인 효율개선 정책과 외피면적에 대한 창면적비의 규제가 필요한 시점이라 생각한다.

• KIEAE Journal
• /
• 제11권2호
• /
• pp.105-111
• /
• 2011

Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

• 한국태양에너지학회 논문집
• /
• 제40권1호
• /
• pp.35-47
• /
• 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.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
• /
• pp.721-725
• /
• 2004

Multiple-count problem is occurred when rectangle objects span across several buckets. The Cumulative Density (CD) histogram is a technique which solves multiple-count problem by keeping four sub-histograms corresponding to the four points of rectangle. Although it provides exact results with constant response time, there is still a considerable issue. Since it is based on a query window which aligns with a given grid, a number of errors may be occurred when it is applied to real applications. In this paper, we proposed selectivity estimation techniques using the generalized cumulative density histogram based on two probabilistic models: (1) probabilistic model which considers the query window area ratio, (2) probabilistic model which considers intersection area between a given grid and objects. In order to evaluate the proposed methods, we experimented with real dataset and experimental results showed that the proposed technique was superior to the existing selectivity estimation techniques. The proposed techniques can be used to accurately quantify the selectivity of the spatial range query on rectangle objects.

• 한국주거학회논문집
• /
• 제14권5호
• /
• pp.37-46
• /
• 2003

The quantitative analysis of view tells how surroundings and sky are showed, and requires understanding of visual perception and three dimensional information of buildings. The visual perception and the existing projection methods for view analysis are examined. The results of this study are as follows: The visual perception on the size is determined by the visual angle, which can be described as a solid angle. The analysis of view by planar projection can be narrow-sighted according to the size of the window and the location of the viewpoint, which will cause the obstacles in the normal direction of the window interfere the view. For the analysis of view by fisheye projection, the area around the focus point is calculated wider than other areas, and so the view ratio depends on the position of the focus point. When analyzing sky view by dividing the sky vault into the differential area, the distortion by projection can be minimized.

• KIEAE Journal
• /
• 제7권4호
• /
• pp.51-56
• /
• 2007

This study focuses on developing natural ventilation system which is able to satisfy the good indoor air quality and air speed. The natural ventilation system developed in this study is for double window façade and it has two operation modes for summer and winter. Operational sections of the devices have been analyzed by CFD simulation to calculate discharge coefficients of openings and estimated indoor air speed. For the analysis of the appropriate installation area ratio for each room and the optimum installation area, TRNFLOW simulation has been used. As the results, we could see that the natural ventilation system can provide the similar pollutant removal performance to 0.7 ACH of mechanical ventilation with appropriate installation area and installation area ratio.

• 한국대기환경학회지
• /
• 제30권3호
• /
• pp.245-250
• /
• 2014

As the number of nursery facilities and infants who stay there is continuously increasing, IAQ (Indoor Air Quality) of nursery facilities should be managed strictly and thoroughly because infants are more susceptible to infections due to their low resistivity. In this study the characteristics of IAQ and ventilation associated factors were investigaed for suggesting a desirable condition for IAQ management. Environmental factors were not much related to IAQ characteristics rather than internal factors such as structures of the room. And the positive effect of ventilation on IAQ was obvious and seemed to hinge on factors related to window area especially window/wall ratio. Results of this study indicate that the structure with broader window area of a room and frequnet ventilation can be an effective way for keeping IAQ of nursery facilities clean and safe.

• KIEAE Journal
• /
• 제6권2호
• /
• pp.35-42
• /
• 2006

This study is to investigate the possibility of a quantitative analysis on sunshine right in apartment houses with a new evaluation index of shading area ratio(SAR) which represents seasonal average value of shaded portion of a window during definite period. SAR values of each apartment houses in a prototype building was calculated depending on apartment building arrangement types and orientations. Since the new method proposed in this research is able to measure the sunshine possibility of the each house in detail, which is more precise and descriptive than the existing method of sunshine judgment standard based on the sunshine hours only at winter solstice, it can be appropriately utilized as a highly qualified sunshine right judgment measures in apartment buildings.

• 한국표면공학회지
• /
• 제41권1호
• /
• pp.28-32
• /
• 2008

In this paper CdS thin films, which were widely used window layer of the CdS/CdTe and the CdS/$CuInSe_2$ heterojunction solar cell, were grown by chemical bath deposition, which is a very attractive method for low-cost and large-area solar cells, and the structural, optical and electrical properties of the films was studied. As the thiourea/$CdAc_2$ mole ratio was increased, the deposition rate of CdS films prepared by CBD was increased due to increasing reaction velocity in solution and the optical bandgap was increased at higher thiourea/$CdAc_2$ mole ratio due to larger grain size and continuous microstructure. The minimum resistivity of the films was at thiourea/$CdAc_2$ mole ratio of 3.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1078-1082
• /
• 2003

A feasibility study for the fabrication of master replication with nanostructures by Nanoimprint Lithography (NIL) was investigated for application of polymer Photonic Bandgap (PBG) devices used in photonic IC. Large area gratings of $9{\times}15(mm^2)$ with p = 400 nm was successfully embossed on PMMA on silicon wafer and the embossing parameters (temperature, pressure, time) were established. A precise control of $O_2$ plasma Reactive Ion Etching (RIE) process time allowed window opening over the whole area despite the presence of wafer bending. Master replication with aspect ratio 1 was successfully fabricated, but master replication with aspect ratio 3 needs to optimize parameters. All replications were done in a NIL process.