• 설비공학논문집
• /
• 제26권9호
• /
• pp.424-433
• /
• 2014

The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

• Journal of Astronomy and Space Sciences
• /
• 제33권4호
• /
• pp.287-293
• /
• 2016

The equatorial region of the Earth's ionosphere exhibits large temporal variations in electron density that have significant implications on satellite signal transmissions. In this paper, the first observation results of the variations in the trough of the equatorial ionospheric anomaly at the permanent Global Navigation Satellite System (GNSS) site in Chuuk (Geographic: $7.5^{\circ}N$, $151.9^{\circ}E$; Geomagnetic: $0.4^{\circ}N$) are presented. It was found that the daytime Global Positioning System (GPS) total electron content (TEC) values vary according to the 27 day period of solar rotation, and that these trends show sharp contrast with those of summer. The amplitudes of the semi-annual anomaly were 12.4 TECU (33 %) on $19^{th}$ of March and 8.8 TECU (23 %) on $25^{th}$ of October respectively, with a yearly averaged value of 38.0 TECU. The equinoctial asymmetry at the March equinox was higher than that at the October equinox rather than the November equinox. Daily mean TEC values were higher in December than in June, which could be interpreted as annual or winter anomalies. The nighttime GPS TEC enhancements during 20:00-24:00 LT also exhibited the semi-annual variation. The pre-midnight TEC enhancement could be explained with the slow loss process of electron density that is largely produced during the daytime of equinox. However, the significant peaks around 22:00-23:00 LT at the spring equinox require other mechanisms other than the slow loss process of the electron density.

• 한국주거학회논문집
• /
• 제13권6호
• /
• pp.11-20
• /
• 2002

The purpose of this study is to investigate the performance level of family events, the events places where the events occur. The subjects of 169 households were selected in Jinju city and data were gathered through a questionnaire method. The data were analyzed by the SPSS package program. The major findings are as follows; 1) Most of the families perform the majority of events except lpchun (the first day of spring), the vernal Equinox Day, the Autumnal Equinox Day, the Vega festival Day, Chilsuk, and the Respect-for-the-Aged Day. 2) Birthday parties score to the highest of all family events. 3) In general, the Lunar New Year's Day, the Full Moon Harvest Day, the ancestor worship ceremony, the 15th of January (in lunar calendar), the feast of a hundred day-old baby among lifetime ceremonies, family members'birthdays, housewarming parties among the other general celebrations, and Parents Day among memorial days are held in their homes. 4) The socialized celebration of the following family events is increasing: the first birthday party, banquets for parents'60th birthday, Christmas, and wedding anniversaries.

• 천문학회지
• /
• 제29권spc1호
• /
• pp.357-358
• /
• 1996

Reanalysis of the observations of Mars made at the Hida Observatory in 1975 with a new image processing method is reported. Red filter images taken in the period before vernal equinox (areocentric longitude of the sun Ls=$0^{\circ}$) revealed dark surface features at the northern high latitudes, while blue filter images taken at the same time showed the extensive polar hood. The latitude of the northernmost feature observed was about $67^{\circ}$N. An extensive north polar cap, which is predicted by most of the existing models and observed with Viking, did not exist in our reanalyzed images obtained at the Hida Observatory in 1975.

• 대순사상과 동아시아종교
• /
• 제3권2호
• /
• pp.147-148
• /
• 2024

• 대한원격탐사학회지
• /
• 제34권5호
• /
• pp.749-762
• /
• 2018

본 연구에서는 고층 건물 신축에 의한 주변 지역의 일조 환경 변화를 계절별로 분석하였다. 지리정보시스템(geographic information system, GIS) 자료를 이용하여 부산광역시 부경대학교 일대를 중심으로 지형과 건물을 구축하고, 고층 건물 건설 전과 후에 대해 계절별로 일조 모델을 수행하였다. 고층 건물 단지 건설 전에도 대상 지역의 남동쪽에 위치한 아파트 단지와 남쪽에 위치한 봉오리산의 영향을 받아 일조 차단 영역이 넓게 나타났다. 고층 건물 단지 건설에 의해 주변 지역의 일조 시간이 감소하였고, 일출과 일몰 시간대에는 일조 차단 면적이 증가하였다. 일출 1시간 후의 경우에는 춘분(1.60%), 추분(1.58%), 하지(1.50%), 동지(1.36%) 순으로 일조 차단 면적이 증가하였다. 부경대학교 동쪽(남쪽)에 건설된 고층 건물 단지는 일출(일몰)시 서쪽(동쪽)으로 1,000 m(750 m) 이상의 지점까지 일조가 차단되었다. 특히, 부경대학교 내부에서는 춘분, 하지, 추분, 동지에 각각 46.61%, 22.75%, 58.56%, 11.31%의 일조 시간이 감소하였다. 부경대학교 기숙사 건물에 대해 겨울철 1주일 동안 일조 시간을 조사한 결과, 남쪽 고층 건물 단지 건설은 기숙사 건물 서쪽(남쪽) 벽면의 일조 면적을 30.91%(49.45%) 정도 감소시켰다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
• /
• pp.25.1-25.1
• /
• 2008

The Weddell Sea Anomaly (WSA) in the ionosphere is characterized by higher plasma density at night than during the day in the region near the Weddell Sea. According to previous studies on the WSA, it is known to occur mostly in southern summer and has not been reported in other seasons. We have utilized more than 13-year TOPEX TEC measurements in order to study how the WSA varies with seasons and how it changes with solar activity. The TOPEX TEC data have been extensively utilized for the climatological study of the ionosphere due to its excellent spatial and temporal coverage. We investigate the seasonal and solar activity variations of the WSA using four seasonal cases (Mar. equinox, Jun. solstice, Sep, equinox, and Dec. solstice) and two solar activity conditions (F10.7<120 for solar minimum and F10.7>120 for solar maximum conditions) for geomagnetically quiet periods. Our analysis shows that the WSA occurs only in the southern summer hemisphere for low F10.7, as in previous studies, but the WSA occurs all of seasons except for winter when F10.7 is high: it is most prominent during the December solstice (southern summer) and still strong during both equinoxes. The WSA appears to be an extreme case of global longitudinal variations at mid- and high-latitudes.

• 한국태양에너지학회 논문집
• /
• 제31권3호
• /
• pp.80-88
• /
• 2011

Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a solid understanding of heliostat's energy concentration characteristics is the most important step in designing of the heliostat field and the whole power plant. The work presented here is the analysis of energy concentration characteristics of heliostat used in 200kW solar thermal power plant, where the receiver located at 43m high in tower has $2{\times}2$m rectangular shape. The heliostat reflective surface is formed by 4 of $1{\times}1$m flat plate mirror facet and the mirror facet is mounted on the spherical frame. The direct normal incident radiation models in vernal equinox, summer solstice, autumnal equinox and winter solstice are first derived from the actually measured data. Then the intercept ratio, heat flux distribution and total energy collected at the receiver for the heliostats located in the various places of the heliostat field are investigated. Finally the effect of mirror facet installation error on the optical performance of the heliostat is analyzed.

• 한국지능시스템학회논문지
• /
• 제25권5호
• /
• pp.437-443
• /
• 2015

이 논문에서는 가시광선 얼굴영상과 그로부터 예측한 열 적외선 텍스처의 데이터 융합에 의한 얼굴인식 방법에 관하여 연구하였다. 제안하는 얼굴인식 기법은 가시광선 얼굴영상과 열 적외선 텍스처를 PCA에 의하여 낮은 차원의 특징공간에서 특징벡터로 변환한 다음, 다층 신경회로망을 사용하여 가시광선 영상 특징으로부터 얼굴의 열적외선 특징을 예측하여 열 적외선 텍스처를 생성하였다. 학습과정에서는 주어진 개체로부터 획득한 한 쌍의 가시광선 및 열 적외선 영상에 대해서 PCA를 이용하여 낮은 차원의 특징공간으로 변환한 다음, 가시광선 영상특징으로부터 열 분포 특징으로 매핑시키는 비선형 함수에 해당하는 신경회로망의 내부 파라미터를 결정한다. 학습된 신경회로망은 입력 가시광선 얼굴 특징으로부터 열 에너지 분포 특성의 PCA계수를 예측하고, 이로부터 열 적외선 텍스처를 생성한다. 대표적인 두 가지 얼굴인식 알고리즘 Eigenfaces와 Fisherfaces을 사용하여 NIST/Equinox 데이터베이스에 대하여 얼굴인식에 관한 실험을 수행하였다. 예측한 열 적외선 텍스처와 가시광선 얼굴영상의 데이터 융합결과는 가시광선 얼굴영상만을 사용한 경우에 비해서 얼굴인식의 성능이 개선되었음을 수신자 조작특성 (ROC) 및 첫 번째 매칭성능에 의하여 검증하였다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.40.2-40.2
• /
• 2010

The Solar Daylighting Technology is considered with the plan that will be able to embody the energy technology which is possible to continue. Daylighting has an considerable advantage of the high effectiveness and the various use because daylighting can use the infrared ray, the visible ray and the ultraviolet rays without energy transformation. In this study, the experiment is tried of making the shape and an arrangement of the reflector different After establishing the reflector in the height(10m) which is fixed. It's also researched on the shape of the efficient reflector using the program(Trace Pro) at the time of the autumnal equinox and the winter solstice at fixed hours.