• Title/Summary/Keyword: central space

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The Spatial Charateristics of Ventilation Efficiency (실내환기효율의 공간적 변화특성에 관한 연구)

  • 김신도;김태식;이희관;이정주
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.3
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    • pp.236-241
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    • 1993
  • Recently, with the ourdoor air pollution, the indoor air pollution devided into living environment and working environment are raised as the problem of indoor space. Also, the more time lived in indoor space, the larger the influence of indoor air pollution. Therefore in this study, the spatial variation of ventilation efficiency was estimated through the experiment using a physical model. The experiment using a physical model. The experiment was conducted in two category; the central zone of ventilated air flow and the corner zone. As the result of experiment, high ventilation efficiency (90$\sim$108%) was shown in the central zone of ventilated air flow. Whereas low ventilation efficiency (46$\sim$77%) was shown in the corner zone. In conclusion, when the designing of ventilation was planned, the zone showed low ventilation efficiency should be considered.

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A STUDY OF LOW-LEVEL BOUNDARY-LAYER TEMPERATURE INVERSION EVENTS IN TAIWAN

  • Liou, Yuei-An;Yan, Shiang-Kun;Wang, Kuo-Chung
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.320-323
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    • 2006
  • Temperature inversion may cause air pollution problems because air pollutants cannot be dissipated through vertical motion of the atmosphere and are accumulated near the surface. The air quality is worsen gradually if an inversion event lasts for a long time. An inversion event is defined as consecutive temperature profiles with occurrence of the temperature inversion condition. In this paper, temperature inversion events over three major cities on Taiwan are analyzed. They are measured by ground-based microwave radiometers installed in Taipei, Taichung, and Kaohsiung from 2002 to 2004 by the Environment Protection Administration (EPA) of Taiwan. Characteristics of temperature inversion events at the three cities are extracted using different classification methods.

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Dual Contrast EPI by Use of a Key Hole Technique

  • Jung, Kwan-Jin
    • Proceedings of the KSMRM Conference
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    • 2001.11a
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    • pp.113-113
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    • 2001
  • Purpose: In the gradient echo EPI the conventional T2*-weighted image is poor in signal as well distorted by the field inhomogeneity. By acquiring a proton density image in addition to th T2*-weighted image at the same scan, the fMRI processing can be improved. Method: The central region of the k space is acquired twice at different time points after th RF pulse while acquiring the other regions onc as described in Fig. 1. In Fig. 1 the segment numbers are chronological. Then, we can get two images of different contrast by interleaving th central region in the k space as done in the dua contrast FSE.

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NEAR-INFRARED PHOTOMETRY OF METAL RICH GLOBULAR CLUSTER M71

  • 경재만;변용익;천문석
    • Journal of Astronomy and Space Sciences
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    • v.14 no.2
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    • pp.194-201
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    • 1997
  • We have carried out JK near-infrared photometry for the central region of the metal rich globular cluster M71, whose (K, J - K) color-magnitude diagram is presented here. Using two independent methods we derive the distance modulus to M71, 12.89 and 12.86 $pm0.12$ respectively. The former is derived using the HB luminosity $M_{Ko}$(HB) = -1.15 for globular clusters having metallicity between -1.0 to -0.3 (Kuchinski et al. 1995). The latter is derived through a comparison with IR photometry of stars in the similar metallicity cluster 47 Tuc. We also estimate the reddening to M71, E(J - K) = 0.13, based on E(B - V) = 0.04 of 47 Tuc.

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Seasonal Variability of Sonic Layer Depth in the Central Arabian Sea

  • Bhaskar, TVS Udaya;Swain, Debadatta;Ravichandran, M
    • Ocean Science Journal
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    • v.43 no.3
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    • pp.147-152
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    • 2008
  • The seasonal variability of sonic layer depth (SLD) in the central Arabian Sea (CAS) (0 to $25^{\circ}N$ and $62-66^{\circ}E$) was studied using the temperature and salinity (T/S) profiles from Argo floats for the years 2002-2006. The atmospheric forcing responsible for the observed changes was explored using the meteorological data from NCEP/NCAR and Quickscat winds. SLD was obtained from sound velocity profiles computed from T/S data. Net heat flux and wind forcing regulated SLD in the CAS. Up-welling and down-welling (Ekman dynamics) associated with the Findlater Jet controlled SLD during the summer monsoon. While in winter monsoon, cooling and convective mixing regulated SLD in the study region. Weak winds, high insolation and positive net heat flux lead to the formation of thin, warm and stratified sonic layer during pre and post summer monsoon periods, respectively.

Video Image Tracking Technique Based On Shape-Based Matching Algorithm

  • Chen, Min-Hsin;Chen, Chi-Farn
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.882-884
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    • 2003
  • We present an application of digital video images for object tracking. In order to track a fixed object, which was shoot on a moving vehicle, this study develops a shape-based matching algorithm to implement the tracking task. Because the shape-based matching algorithm has scale and rotation invariant characteristics, therefore it can be used to calculate the similarity between two variant shapes. An experiment is performed to track the ship object in the open sea. The result shows that the proposed method can track the object in the video images even the shape change largely.

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Road Extraction Based on Watershed Segmentation for High Resolution Satellite Images

  • Chang, Li-Yu;Chen, Chi-Farn
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.525-527
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    • 2003
  • Recently, the spatial resolution of earth observation satellites is significantly increased to a few meters. Such high spatial resolution images definitely will provide lots of information for detail-thirsty remote sensing users. However, it is more difficult to develop automated image algorithms for automated image feature extraction and pattern recognition. In this study, we propose a two-stage procedure to extract road information from high resolution satellite images. At first stage, a watershed segmentation technique is developed to classify the image into various regions. Then, a knowledge is built for road and used to extract the road regions. In this study, we use panchromatic and multi-spectral images of the IKONOS satellite as test dataset. The experiment result shows that the proposed technique can generate suitable and meaningful road objects from high spatial resolution satellite images. Apparently, misclassified regions such as parking lots are recognized as road needed further refinement in future research.

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Geometrical Comparisons between Rigorous Sensor Model and Rational Function Model for Quickbird Images

  • Teo, Tee-Ann;Chen, Liang-Chien
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.750-752
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    • 2003
  • The objective of this investigation is to compare the geometric precision of Rigorous Sensor Model and Rational Function Model for QuickBird images. In rigorous sensor model, we use the on-board data and ground control points to fit an orbit; then, a least squares filtering technique is applied to collocate the orbit. In rational function model, we first use the rational polynomial coefficients provided by the satellite company. Then the systematic bias of the coefficients is compensated by an affine transformation using ground control points. Experimental results indicate that, the RFM provides a good approximation in the position accuracy.

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A Comparison of Daedeok Innopolis Cluster with the San Diego Biotechnology Cluster

  • Kim, Sang-Tae;An, Gi-Don
    • World Technopolis Review
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    • v.1 no.2
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    • pp.118-128
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    • 2012
  • This paper suggests policy implications for Daedeok Innopolis (DI) in Daejeon by comparing the development and problems of DI with the San Diego biotechnology cluster. DI has strengthened its capabilities for technology commercialization and business activities after having created and managed by the Korean central government. While DI has been successful in increasing the number of institutes, researchers, research activities, however, its dynamism is not rigorous enough to be a regional innovative system. San Diego's scientific and entrepreneurial community shows the importance of formulating social and spatial contexts for mutual interactions and engagements. In San Diego, UCSD and networking organizations, especially CONNECT, are central in promoting interactions and communications between regional constituents including entrepreneurs, academics and local governments. The mechanisms of San Diego biotechnology imply that DI should provide more attention to designing and developing social and geographical space that can unleash the creative power of social interactions. To build an innovative regional system, DI needs to renovate its space, public-private relationship and networking platforms.

A Multi-Epoch, Simultaneous Water and Methanol Maser Survey Toward Intermediate-Mass Young Stellar Objects

  • Bae, Jae-Han;Kim, Kee-Tae;Youn, So-Young;Kim, Won-Ju;Byun, Do-Young;Kang, Hyun-Woo;Oh, Chung-Sik
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.83.1-83.1
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    • 2011
  • We report multi-epoch, simultaneous 22 GHz water and 44 GHz Class I methanol maser line survey towards 180 intermediate-mass young stellar objects, including 14 Class 0, 19 Class I objects, and 147 Herbig Ae/Be stars. We detected $H_2O$ and $CH_3OH$ maser emission towards 16 (9%) and 10 (6%) sources with one new $H_2O$ and six new $CH_3OH$ maser sources. The detection rates of both masers rapidly decrease as the central (proto)stars evolve, which is contrary to the trends in high-mass star-forming regions. This suggests that the excitations of the two masers are closely related to the evolutionary stage of the central (proto)stars and the circumstellar environments. $H_2O$ maser velocities deviate on average 9 km s-1 from the ambient gas velocities whereas $CH_3OH$ maser velocities well match with. For both maser emissions, large velocity difference (${\mid}v_{H2O}-v_{sys}{\mid}\;>\; 10kms^{-1}\; and\;{\mid}v_{CH3OH}-v_{sys}{\mid}\;>\;1kms^{-1}$) is mostly confined to Class 0 objects. The formation and disappearance of $H_2O$ maser lines are frequent and the integrated intensities of them change up to two orders of magnitude. In contrast, $CH_3OH$ maser lines usually show no significant change in the intensity, shape, and velocity. This consistent with the previous suggestion that $H_2O$ maser emission originates from the base of an outflow while 44 GHz Class I $CH_3OH$ maser emission arises from the interaction region of the outflow with the ambient gas. The isotropic maser luminosities are well correlated with the bolometric luminosities of the central the objects. The fitted relations are $L_{H2O}=1.71{\ast}10^{-9}(L_{bol})^{0.97}$ and $L_{CH3OH}=1.71{\ast}10^{-10}(L_{bol})^{1.22}$.

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