• Title/Summary/Keyword: Window area

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A Study on Characteristics of Main Indoor Air Pollutants and Ventilation in Nursery Facilities (어린이집 실내공기 중 주요 오염물질의 특성 및 환기에 관한 연구)

  • Kim, Sang Cheol;Kang, Byeong-Chang;Lee, Sang-Uk;Kim, Gi-Doo;Seo, Won-Ho;Kim, Jong-Heon
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.3
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    • pp.245-250
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    • 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.

Heteroface p-$Al_{x}Ga_{1-x}As/p-GaAs/n-GaAs/n^{+}$-GaAs Solar Cell Grown by MOCVD (MOCVD를 이용한 Heteroface p-$Al_{x}Ga_{1-x}As/p-GaAs/n-GaAs/n^{+}$-GaAs 태양전지의 개발)

  • 창기근;임성규
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.1
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    • pp.30-39
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    • 1991
  • The influence of physical parameters (Al mole fraction, thickness, doping concentration) in the window and emitter on the efficiency characteristics of heteroface p-$Al_{x}Ga_{1-x}As/p-GaAs/n-GaAs/n^{+}$-GaAs solar cell is investigated. The maximum efficiency theoretically calculated in this device is obtained when a thickness of the window is in a range of (400-1000))$\AA$and a thickness/doping concentration of the emitter is in a range of (0.5-0.8)$\mu$m/(1-7)${\times}10^{17}cm^{-3}$, respectively. Also is the efficiency improved according to the increase of Al mole fraction in the indirect gap window(0.41${\le}x{\le}1.0$). The optimum designed heteroface cell with an area of 0.165cm$^2$fabricated using MOCVD exhibits an active area conversion efficiency of 17%, having a short circuit current density of 21.2mA/cm\ulcorner an open circuit voltage of 0.94V, and a fill factor of 0.75 under ELH-100mW/cm$^2$illumination.

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AN ANALYSIS OF THE AUTOMATCHING USING LANDSAT TM DATA AND ASTRONOMICAL APROACH (LANDSAT TM 자료를 사용한 AUTOMATCHING ALGORITHM의 분석 및 천문학 연구 분야로서의 제안)

  • 박종현;최규홍;조성의;박경윤
    • Journal of Astronomy and Space Sciences
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    • v.8 no.1
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    • pp.115-123
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    • 1991
  • Automatching algorithm is suitable for cross-correlation, which showed correlation surface about maximal correlation coefficient. The size of the window area must be determined empirically, whereas window size generally chosen as a compromise between speed and accuracy. It is possible that epipolar transform prevented from mismatching and decreased search space. In application of the astronomical fields, automatching algorithm mainly used to planet surface recovery in satellite image.

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A study on the Insulation Performance of the Super Window applied to building energy efficiency rating (초단열 슈퍼윈도우의 건물에너지효율등급 적용 연구)

  • Jang, Cheol-Yong;Kim, Chi-Hoon;Ahn, Byung-Lip
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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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.

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Yawn Recognition Algorism for Prevention of Drowsy Driving (졸음운전 방지를 위한 하품 인식 알고리즘)

  • Yoon, Won-Jong;Lee, Jaesung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.447-450
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    • 2013
  • This paper proposes the way to prevent drowsy driving by recognizing drivers eyes and yawn using a front camera. The method uses the Viola-Jones algorithm to detect eyes area and mouth area from detection face region. In the eyes area, it uses the Hough transform to recognize eye circle in order to distinguish drowsy driving. In the mouth area, it determines whether for the driver to yawn through a sub-window testing by applying a HSV-filter and detecting skin color of the tongue. The test result shows that the recognition rate of yawn reaches up to 90%. It is expected that the method introduced in this paper might contribute to reduce the number of drowsy driving accidents.

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A Framework for Wide-area Monitoring of Tree-related High Impedance Faults in Medium-voltage Networks

  • Bahador, Nooshin;Matinfar, Hamid Reza;Namdari, Farhad
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.1-10
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    • 2018
  • Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.

Image Path Searching using Auto and Cross Correlations

  • Kim, Young-Bin;Ryu, Kwang-Ryol
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.747-752
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    • 2011
  • The position detection of overlapping area in the interframe for image stitching using auto and cross correlation function (ACCF) and compounding one image with the stitching algorithm is presented in this paper. ACCF is used by autocorrelation to the featured area to extract the filter mask in the reference (previous) image and the comparing (current) image is used by crosscorrelation. The stitching is detected by the position of high correlation, and aligns and stitches the image in shifting the current image based on the moving vector. The ACCF technique results in a few computations and simplicity because the filter mask is given by the featuring block, and the position is enabled to detect a bit movement. Input image captured from CMOS is used to be compared with the performance between the ACCF and the window correlation. The results of ACCF show that there is no seam and distortion at the joint parts in the stitched image, and the detection performance of the moving vector is improved to 12% in comparison with the window correlation method.

Measurement of Reflection Coefficient of Sound Absorbent Material with Respect to Angle of Incidence and Its Associated Errors (입사각에 따른 흡음재의 반사 계수 측정 방법론 및 오차에 대한 고찰)

  • 이수열;김상렬;김양한
    • Journal of KSNVE
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    • v.4 no.3
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    • pp.295-305
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    • 1994
  • The reflection coefficient of a material at oblique incidence is measured in a free field. The sound pressure distributions are measured at discrete points on two measurement lines and then decomposed into plane wave components by using spatial Fourier transform. The inciedent and reflected plane wave components are obtained from a set of "decomposition equations" of which uses the plane wave propagation theory. Numerical simulations and experiments have been performed to see the effect of finite size of measurement area. To reduce this effect, a window fuction has been performed to see the effects of finite size of mesurement area. To reduce this effect, a window function has been proposed and its effect on the measurement of sound absorbing material property has been studied as well. The reflection coefficient obtained by this method is compared with those obtained from other methods; 2-microphone method in a duct and an expirical equation of which determines the characteristic impedance .rho.c and propagation constant k of a material from flow resistance information.formation.

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Spatial Selectivity Estimation for Intersection region Information Using Cumulative Density Histogram

  • Kim byung Cheol;Moon Kyung Do;Ryu Keun Ho
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.721-725
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    • 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.

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An Experimental Study on the Field Measurement Methods of the Sound Insulation Performance of Window (현장에서의 창의 차음성능 측정방법에 관한 실험적 연구)

  • Lee, Ok-Kyun;Park, Hyeon-Ku;Choi, Hyung-Wook;Song, Hyuk;Kim, Sun-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.600-605
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    • 2000
  • The aim of this study is to compare the sound insulation performances of window depending on the measurement methods through the field test and analyze the factors that affect the sound insulation performances. Four measurement methods which are specified in the Koran Standard 2235 and the International Standard 140-5 were selected for the study; the outdoor sound source method which is classified the l000mm method and the 10mm method, the indoor sound source method, and the ISO method. The result of this study is that the sound insulation performance of the windows was the best when measured according to the ISO method and the worst the indoor sound source method. Through the study it was found that the main factors affecting the sound insulation performance of the windows were the correction of the specimen's area and the equivalent sound absorption area of the receiving room.

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