• 제목/요약/키워드: space-time correlation

검색결과 435건 처리시간 0.033초

DYNAMICAL CHARACTERISTICS OF THE QUIET TRANSITION REGION: SPATIAL CORRELATION STUDIES OF H I 931 AND S VI 933 UV LINES

  • YUN HONG SIK;CHAE JONG CHUL;POLAND A. I.
    • 천문학회지
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    • 제31권1호
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    • pp.1-17
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    • 1998
  • To understand the basic physics underlying large spatial fluctuations of intensity and Doppler shift, we have investigated the dynamical charctersitics of the transition region of the quiet sun by analyzing a raster scan of high resolution UV spectral band containing H Lyman lines and a S VI line. The spectra were taken from a quiet area of $100'\times100'$ located near the disk center by SUMER on board SOHO. The spectral band ranges from 906 A to 950 A with spatial and spectral resolution of 1v and $0.044 {\AA}$, respectively. The parameters of individual spectral lines were determined from a single Gaussian fit to each spectral line. Then, spatial correlation analyses have been made among the line parameters. Important findings emerged from the present analysis are as follows. (1) The integrated intensity maps of the observed area of H I 931 line $(1\times10^4 K)$ and S VI 933 line $(2\times10^5 K)$ look very smilar to each other with the same characterstic size of 5". An important difference, however, is that the intensity ratio of brighter network regions to darker cell regions is much larger in S VI 933 line than that in H I 931 line. (2) Dynamical features represented by Doppler shifts and line widths are smaller than those features seen in intensity maps. The features are found to be changing rapidly with time within a time scale shorter than the integration time, 110 seconds, while the intensity structure remains nearly unchanged during the same time interval. (3) The line intensity of S VI is quite strongly correlated with that of H I lines, but the Doppler shift correlation between the two lines is not as strong as the intensity correlation. The correlation length of the intensity structure is found to be about 5.7' (4100 km), which is at least 3 times larger than that of the velocity structure. These findings support the notion that the basic unit of the transition region of the quiet sun is a loop-like structure with a size of a few $10^3 km$, within which a number of unresolved smaller velocity structures are present.

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박물관 전시공간에서의 관람자 시각행동과 가시영역에 관한 조사 연구 - 부산박물관, 국립김해박물관을 중심으로 - (A Study on the Visitor's Visual Behavior and Isovist Area in Museum Exhibition Space - Focus on the Busan Museum, Gimhae National Museum -)

  • 유재엽;최준혁;임채진
    • 한국실내디자인학회논문집
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    • 제19권6호
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    • pp.197-205
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    • 2010
  • For the spatial experience of spectators visiting a museum, the route search of trying to follow the spatial structure or production of exhibition and the information search of trying to see are accomplished at the same time. In such process, the spectator's reaction of visual perception produces the result of emotional reaction and action exchanged between human and space by going through the recognition and perception on the target of environment factor. For the spatial experience of a spectator, the reaction of visual perception which interacts according to the exhibit and exhibition environment within space according to viewing purpose, interest and concern of spectator comes out as visual activity which is an activity to understand the spatial information shown as various activities according to spatial structure and unfolding characteristics of the display. The purpose of this study is to identify The Correlation of Spectator Movement Created According to Structural Form of Exhibition Area Based on Interaction between Exhibition Area Structure and Spectator to utilize as basic material while designing museum exhibition using isovist field which is a quantitative analysis tool of spectator's visual behavior and spatial structure at each exhibition area.

Effects of solar variations on standing Alfven waves in the dayside magnetosphere: Polar observations

  • Kim, Khan-Hyuk;Takahashi, Kazue
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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    • pp.23.4-23.4
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    • 2008
  • In March and April 2001, the apogee (~9 Re) of the Polar spacecraft was located near the subsolar magnetopause with its orbital plane nearly parallel to a magnetic meridian plane. Polar electric and magnetic field data acquired during the two-month interval of solar maximum have been used to study fundamental standing Alfven waves near the subsolar meridian plane (magnetic local time = 1000-1400 hours) at magnetic latitudes from the equator to $\pm45$ degrees and at L values between 7 and 12. In the frequency band from 1.5 to 10 mHz, fundamental mode oscillations were identified based on high coherence (more than 0.7) and an approximately 90-degree phase shift between the azimuthal magnetic and radial electric field components. The L dependence of the fundamental frequencies is studied, and the frequencies are compared with those observed near the solar minimum interval (Takahashi et al. 2001). We found that the average frequencies in solar maximum are lower than those in solar minimum by a factor of ~2. This implies that the mass density in solar maximum is higher than that in solar minimum by a factor of ~4. Since there is a positive correlation between solar irradiance and solar activity, we suggest that the ionosphere in solar maximum produces more ions and load magnetic flux tubes with more ions.

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아파트단지 내 보육시설의 공간계획에 관한 연구 - 군포 산본 신도시의 사례를 중심으로 - (A Study on the Space Planning of the Childcare Facilities in Apartment Complex - Focused on the cases of Sanbon New Town in Gunpo City -)

  • 이민자;박재승
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제10권2호
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    • pp.91-98
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    • 2004
  • Low birth rate problem in Korea has been mainly derived from the increasing number of female employment and the change of consciousness of female. According to the recent report, some other causes of low birth rate are from the difficulty of using childcare facilities with quality services and the relative lack of quantities of the facilities. The basic principle of childcare includes protection, education, nutrition, safety, service to parents, and correlation with community. Childcare has been deemed to be the social system even to guarantee the parents' right of work. Even though a lot of progress has been made in childcare facilities by changes for a long period of time, the research on the actual condition shows that there are relatively little changes of the space organization of the childcare facilities reflecting characteristics of community and developmental characteristics of infants and children. Now a days it has been appeared as a social problem that childcare has to be needed as a part of systematic education program for such an important infant era.

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Toward accurate synchronic magnetic field maps using solar frontside and AI-generated farside data

  • Jeong, Hyun-Jin;Moon, Yong-Jae;Park, Eunsu
    • 천문학회보
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    • 제46권1호
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    • pp.41.3-42
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    • 2021
  • Conventional global magnetic field maps, such as daily updated synoptic maps, have been constructed by merging together a series of observations from the Earth's viewing direction taken over a 27-day solar rotation period to represent the full surface of the Sun. It has limitations to predict real-time farside magnetic fields, especially for rapid changes in magnetic fields by flux emergence or disappearance. Here, we construct accurate synchronic magnetic field maps using frontside and AI-generated farside data. To generate the farside data, we train and evaluate our deep learning model with frontside SDO observations. We use an improved version of Pix2PixHD with a new objective function and a new configuration of the model input data. We compute correlation coefficients between real magnetograms and AI-generated ones for test data sets. Then we demonstrate that our model better generate magnetic field distributions than before. We compare AI-generated farside data with those predicted by the magnetic flux transport model. Finally, we assimilate our AI-generated farside magnetograms into the flux transport model and show several successive global magnetic field data from our new methodology.

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초등학생 체육영재의 운동능력 검사를 위한 인지민첩성 측정방법 개발 (The Development of Method for Cognitive Agility of Elementary Sports Gifted Student)

  • 김도윤;김원현;김영욱
    • 디지털융복합연구
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    • 제11권6호
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    • pp.299-309
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    • 2013
  • 본 연구의 목적은 체육영재를 판별하는 종목으로써 인지능력과 함께 체력요인을 통합하여 평가하기 위한 측정방법을 개발함에 있다. 개발된 종목에 대한 타당도 검증을 위하여 2~6학년 초등학생 369명(체육영재와 비영재 포함)을 대상으로 체격 및 체력, 인지민첩성 측정을 실시하였으며 결과는 다음과 같다. 남녀 저학년과 고학년 체육영재의 인지민첩성 성공빈도는 비영재보다 높았다(p<.05). 인지민첩성 소요시간은 남녀 체육영재 집단이 비영재보다 유의하게 높았다(p<.05). 인지민첩성은 모든 체격요인간 유의한 상관성이 없었다(p<.05). 남녀 체육영재의 50m달리기와 사이드스텝은 인지민첩성 시간과 상관성이 있었다(p<.05). 공간지각력은 고학년 체육영재 집단이 비영재 집단보다 높은 경향을 보였다. 인지민첩성은 남녀 고학년 체육영재 집단에서 공간지각력과 유의한 정적 상관성을 보였다(p<.05). 이상의 결과들은 본 연구에서 개발된 인지민첩성 평가종목이 초등학교 남녀 학생들의 인지력과 민첩성을 반영하는 통합적 평가방법임을 나타낸다.

Change points detection for nonstationary multivariate time series

  • Yeonjoo Park;Hyeongjun Im;Yaeji Lim
    • Communications for Statistical Applications and Methods
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    • 제30권4호
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    • pp.369-388
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    • 2023
  • In this paper, we develop the two-step procedure that detects and estimates the position of structural changes for multivariate nonstationary time series, either on mean parameters or second-order structures. We first investigate the presence of mean structural change by monitoring data through the aggregated cumulative sum (CUSUM) type statistic, a sequential procedure identifying the likely position of the change point on its trend. If no mean change point is detected, the proposed method proceeds to scan the second-order structural change by modeling the multivariate nonstationary time series with a multivariate locally stationary Wavelet process, allowing the time-localized auto-correlation and cross-dependence. Under this framework, the estimated dynamic spectral matrices derived from the local wavelet periodogram capture the time-evolving scale-specific auto- and cross-dependence features of data. We then monitor the change point from the lower-dimensional approximated space of the spectral matrices over time by applying the dynamic principal component analysis. Different from existing methods requiring prior information on the type of changes between mean and covariance structures as an input for the implementation, the proposed algorithm provides the output indicating the type of change and the estimated location of its occurrence. The performance of the proposed method is demonstrated in simulations and the analysis of two real finance datasets.

Identifying the plasmapause locations for periods under unusually prolonged and weaker solar conditions

  • Cho, Junghee;Lee, Dae-Young;Shin, Dae-Kyu;Kim, Jin-Hee;Park, Mi-Young;Kim, Thomas Kyoung-Ho
    • 천문학회보
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    • 제38권2호
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    • pp.93.1-93.1
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    • 2013
  • The Earth's radiation belts consist of an inner belt and an outer belt, being separated by the slot region. It is well known that the variations of the inner edge of the outer belt and the location of the plasmapause (Lpp) are closely related to each other. Different waves exist inside and outside the plasmasphere, playing different roles in the particle dynamics. The plasmapause is well known to be influenced by solar wind conditions and geomagnetic disturbances. Therefore, it is important to precisely determine the location of the plasmapause and develop a prediction scheme. In this study, we identified the location of the plasmapause using the plasma density data from the Time History of Events and Macroscale Interactions During Substorms (THEMIS). The plasmapause is determined by requiring density gradient of a factor of 15 within L-change = 0.5. We statistically determined Lpp as a function of preceding geomagnetic indices. Also, we determined the relations between Lpp and preceding solar wind conditions by estimating correlation coefficients. These relations give us predicting models of Lpp as a function of preceding solar wind parameters and geomagnetic indices. As our database covers a period over the ascending phase from near-sunspot minimum, our statistical results differ somewhat from previous works that cover near-sunspot maximum. Finally, we give some comparative examples obtained from the Van Allen Probes data.

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도시형 한옥의 안마당 사용실태에 관한 기초적 조사 -서울 북촌마을을 중심으로- (A Study on a Application of the Inner Court in Urban Traditional Housing - Focused on the Bukchon Village, Seoul -)

  • 박현옥;김현아;백혜선;이상미
    • 한국디지털건축인테리어학회논문집
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    • 제6권2호
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    • pp.39-46
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    • 2006
  • "Urban traditional housing" means a type of urban housing which retains characteristics of traditional Korean houses for ordinary people. It is a form of housing created in the process in which traditional Korean ways of life are applied to swift modernization. In Korea's traditional housing, the "court" functioned as a living space that promoted family bonding. The space of the court still remains in the urban traditional housing. However, rapid popularization of the westernized housing form, i.e., apartments, resulted in standardization and westernization of our housing and living patterns, and as a result, the court in urban traditional housing came to lose its original meaning. The objects of this study are residents of urban traditional housing. By studying them, this research aims, firstly, to understand the meaning of the inner court, secondly to analyze correlation between the residents' consciousness of the inner court and their use of the space, and ultimately to find various possible forms of our future housing. For this research, twenty six houses in the Gahoe-dong area in which urban traditional houses are densely built up were investigated. According to the result of this research, the inner court in current urban traditional housing is a space existing inside a house but directly exposed to outer air at the same time. It is a private but shared space. It contributes to forming a pleasant atmosphere by facilitating ventilation and providing sunlight. In addition, it is a living space that actively reflects the Korean living style that values family life.

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Enhanced Nitrogen in Morphologically Disturbed Blue Compact Galaxies at 0.20 < z < 0.35: Probing Galaxy Merging Features

  • 정지원;이수창;성언창;염범석;;이원형;경재만
    • 천문학회보
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    • 제38권1호
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    • pp.39-39
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    • 2013
  • We present a study of correlations between the elemental abundances and galaxy morphologies of 91 blue compact galaxies (BCGs) at z=0.20-0.35 with Sloan Digital Sky Survey (SDSS) DR7 data. We classify the morphologies of the galaxies as either 'disturbed' or 'undisturbed', by visual inspection of the SDSS images, and using the Gini coefficient and M20. We derive oxygen and nitrogen abundances using the Te method. We find that a substantial fraction of BCGs with disturbed morphologies, indicative of merger remnants, show relatively high N/O and low O/H abundance ratios. The majority of the disturbed BCGs exhibit higher N/O values at a given O/H value compared to the morphologically undisturbed galaxies, implying more efficient nitrogen enrichment in disturbed BCGs. We detect Wolf-Rayet (WR) features in only a handful of the disturbed BCGs, which appears to contradict the idea that WR stars are responsible for high nitrogen abundance. Combining these results with Galaxy Evolution Explorer (GALEX) GR6 ultraviolet (UV) data, we find that the majority of the disturbed BCGs show systematically lower values of the $H{\alpha}$ to near-UV star formation rate ratio. The equivalent width of the $H{\beta}$ emission line is also systematically lower in the disturbed BCGs. Based on these results, we infer that disturbed BCGs have undergone star formation over relatively longer time scales, resulting in a more continuous enrichment of nitrogen. We suggest that this correlation between morphology and chemical abundances in BCGs is due to a difference in their recent star formation histories.

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