• 제목/요약/키워드: Spatial experiment

검색결과 778건 처리시간 0.028초

Numerical study on temporal resolution of meteorological information for prediction of Asian dust (황사의 확산예측을 위한 기상정보의 시간해상도에 관한 수치연구)

  • Lee Soon-Hwan;Gwak Eun-Young;Ryu Chan-Su;Moon Yun-Seob
    • Journal of Environmental Science International
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    • 제13권10호
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    • pp.891-902
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    • 2004
  • In order to predict air pollution and Yellow-sand dispersion precisely, it is necessary to clarify the sensitivity of meteorological field input interval. Therefore numerical experiment by atmospheric dynamic model(RAMS) and atmospheric dispersion model(PDAS) was performed for evaluating the effect of temporal and spatial resolution of meteorological data on particle dispersion. The results are as follows: 1) Base on the result of RAMS simulation, surface wind direction and speed can either synchronize upper wind or not. If surface wind and upper wind do not synchronize, precise prediction of Yellow-sand dispersion is strongly associated with upwelling process of sand of particle. 2) There is no significant discrepance in distribution of particle under usage of difference temporal resolution of meteorological information at early time of simulation, but the difference of distribution of particles become large as time goes by. 3) There is little difference between calculated particles distributions in dispersion experiments with high temporal resolution of meteorological data. On the other hand, low resolution of meteorological data occur the quantitative difference of particle density and there is strong tendency to the quantitative difference.

Evaluation on Flexural Performance of One-Way Hollow Slabs according to the Shear Reinforcement (전단보강에 따른 일방향 중공슬래브의 휨 성능 평가)

  • Yu, Yu-Jin;Seok, Keun-Young;Kim, Gee-Cheol;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • 제14권2호
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    • pp.79-86
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    • 2014
  • The purpose of this study is intended to determine the validity of shear reinforcement by evaluating flexural performance in the hollow slab. The hollow slab is relatively light and second moment of inertia is large. Due to these characteristics, it can be used to slab system efficiently. Therefore the prediction of the structural behaviors is very important because of decrease of shear and flexural strength which is caused by hollow section of slab interior. In this study, the flexural test were performed to analyze the flexural capacity of the hollow slab w/ or w/o shear reinforcement. A total of six full scale specimens were tested. These specimens have three cases of reinforcing bar ratio, 0.009, 0.018 and 0.024. To verify the flexural behavior such as ultimate load, load-deflection and crack pattern, the flexural experiment were tested by using loading frame. Experimental results have shown that the flexural behavior are depend on the reinforcing bar ratio. Also the hollow slab with shear reinforcement have shown flexural behavior. Therefore, it is appropriate that the hollow slab is reinforced by shear reinforcement to improve the flexural performance of the hollow slab.

Application of the Empirical Orthogonal Functions on the GRACE Spherical Harmonic Solutions

  • Eom, Jooyoung;Seo, Ki-Weon
    • Journal of the Korean earth science society
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    • 제39권5호
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    • pp.473-482
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    • 2018
  • During the period of 2002 to 2017, the Gravity Recovery And Climate Experiment (GRACE) had observed time-varying gravity changes with unprecedented accuracy. The GRACE science data centers provide the monthly gravity solutions after removing the sub-monthly mass fluctuation using geophysical models. However, model misfit makes the solutions to be contaminated by aliasing errors, which exhibits peculiar north-south stripes. Two conventional filters are used to reduce the errors, but signals with similar spatial patterns to the errors are also removed during the filtering procedure. This would be particularly problematic for estimating the ice mass changes in Western Antarctic Ice Sheet (WAIS) and Antarctic Peninsula (AP) due to their similar spatial pattern to the elongated north-south direction. In this study, we introduce an alternative filter to remove aliasing errors using the Empirical Orthogonal Functions (EOF) analysis. EOF can decompose data into different modes, and thus is useful to separate signals from noise. Therefore, the aliasing errors are effectively suppressed through EOF method. In particular, the month-to-month mass changes in WAIS and AP, which have been significantly contaminated by aliasing errors, can be recovered using EOF method.

Correlation between the temperature and elastic properties of the light guide plate in edge-lit light-emitting-diode backlights

  • Kim, Jae-Hyun;Kim, Tae-Hyun;Lee, Byung-Woo;Seo, Jae-Seok;Ko, Jae-Hyeon
    • Journal of Information Display
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    • 제12권1호
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    • pp.23-27
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    • 2011
  • The correlation between the temporal and spatial variations of the elastic constant and temperature change was examined for a light guide plate (LGP) adopted in the edge-lit light-emitting-diode backlight for mobile applications, using the micro- Brillouin light scattering method. The velocity of sound and the elastic constant $C_{11}$ of an LGP made from bisphenol-A polycarbonate (PC) were investigated as functions of temperature, time, and position on the LGP. The temporal variation of $C_{11}$ exhibited an exponential decay, while the spatial variation of $C_{11}$ reflected the temperature distribution on the LGP. The glass transition temperature of the PC LGP was found to be located at $155^{\circ}C$. The result showed that systematic transformation between the elastic property and the temperature is possible and that the temperature distribution on the bulk LGP can be accurately probed via the present experiment method, without using any special temperature measurement equipment.

The Improvement of the Road Facility Database Creation Using a Mobile GIS (모바일 GIS를 활용한 도로시설물 DB구축의 효율성 향상)

  • Lee, Hyun-Jik;Kim, Hyun-Tae
    • Journal of Korean Society for Geospatial Information Science
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    • 제11권4호
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    • pp.53-60
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    • 2003
  • GIS was introduced to spatial information of complex and various facility systematically and scientifically. And, recently, new trend has been spread by Mobile GIS owing to its fast development of information and communication technology. However, these Mobile GIS techniques were introduced in maintenances of various facilities. Due to its mismanagement, the use became insufficient in facilities causing database creation to require realism and mobility. Therefore, in this research to road facility of various facilities, it deduced improving the work process by using a Mobile GIS to analyze work process of the road facility database creation. And, through an experiment, by comparing and analyzing road facilities database creation process by existing method and improving method, could improvement of road facility database creation using a Mobile GIS.

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A Study on the Relativity Between the Theatre's Composition Principle and Urban Concept - Focused on the Productions that are Applied for International Ideas Competition for the Design of the Seoul Performing Arts Center - (극장의 구성 원리와 도시 개념의 상관성에 관한 연구 - Seoul Performing Art Center 국제 공모전을 중심으로 -)

  • Lim Jong-Yup;Kwon Ik-Hyun
    • Korean Institute of Interior Design Journal
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    • 제15권1호
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    • pp.47-54
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    • 2006
  • Stages, in the theatrical spaces, were space, which incorporates aspects of cities. Hence, the stages have been constituted to materialize sequence of city, which has exact number, proportion and order of ideal city. In addition, it has accomplished change, which depends on type of performance with the social condition and culture of generation, city has. However, the original form of theatrical space were forgotten on account of the various changes of theatrical form with modem movement since the end of 19th century, and theatrical space, which does not relate with its space of city, was started to constitute. Particularly in contemporary society, the theatre can give vitality to the citizens, and also theatrical architecture as a commercial code has been a general form, though it takes important role, which improves cultural value with technical improvement of cities development of society. Thus, this study analyzed urbanity ,which theatres have incorporated historically, and deduced a correlativity from to be based on constitution of space in visual, perceptual, spatial constitution and functional role. Focused on published SPAC international competition, it was interpreted by contemporary focus, therefore, this experiment suggests constitution of theatrical spaces of information, takes urbanity, through to analyze visual, perceptual, spatial constitution and functional role in context of contemporary city.

A GEOSTATISTIC BASED SEGMENTATION APPROACH FOR REMOTELY SENSED IMAGES

  • Chen, Qiu-Xiao;Luo, Jian-Cheng
    • Proceedings of the KSRS Conference
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1323-1325
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    • 2003
  • As to many conventional segmentation approaches , spatial autocorrelation, perhaps being the first law of geography, is always overlooked. Thus, the corresponding segmentation results are always not so satisfying, which will further affect the subsequent image processing or analyses. In order to improve segmentation results, a geostatistic based segmentation approach with the consideration of spatial autocorrelation hidden in remote-sensing images is proposed in this article. First, by calculating the mean variance between each pair of pixels at given different lag distances, information like the size of typical targets in the scene can be obtained, and segmentation thresholds are calculated accordingly. Second, an initial region growing segmentation approach is implemented. Finally, based on the segmentation thresholds obtained at the first step and the initial segmentation results, the final segmentation results are obtained using the same region growing approach by taking the local mutual best fitting strategy. From the experiment results, we found the approach is rather promising. However, there still exists some problems to be settled, and further researches should be conducted in the future.

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Sub-Pixel Analysis of Hyperspectral Image Using Linear Spectral Mixing Model and Convex Geometry Concept

  • Kim, Dae-Sung;Kim, Yong-Il;Lim, Young-Jae
    • Korean Journal of Geomatics
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    • 제4권1호
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    • pp.1-8
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    • 2004
  • In the middle-resolution remote sensing, the Ground Sampled Distance (GSD) that the detector senses and samples is generally larger than the actual size of the objects (or materials) of interest, and so several objects are embedded in a single pixel. In this case, as it is impossible to detect these objects by the conventional spatial-based image processing techniques, it has to be carried out at sub-pixel level through spectral properties. In this paper, we explain the sub-pixel analysis algorithm, also known as the Linear Spectral Mixing (LSM) model, which has been experimented using the Hyperion data. To find Endmembers used as the prior knowledge for LSM model, we applied the concept of the convex geometry on the two-dimensional scatter plot. The Atmospheric Correction and Minimum Noise Fraction techniques are presented for the pre-processing of Hyperion data. As LSM model is the simplest approach in sub-pixel analysis, the results of our experiment is not good. But we intend to say that the sub-pixel analysis shows much more information in comparison with the image classification.

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Spaceborne Gravity Sensors for Continental Hydrology and Geodynamic Studies

  • Shum C. K.;Han Shin-Chan;Braun Alexander
    • Korean Journal of Remote Sensing
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    • 제21권1호
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    • pp.51-57
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    • 2005
  • The currently operating NASA/GFZ Gravity Recovery and Climate Experiment (GRACE) mission is designed to measure small mass changes over a large spatial scale, including the mapping of continental water storage changes and other geophysical signals in the form of monthly temporal gravity field. The European Space Agency's Gravity field and steady state Ocean Circulation Explorer (GOCE) space gravity gradiometer (SGG) mission is anticipated to determine the mean Earth gravity field with an unprecedented geoid accuracy of several cm (rms) with wavelength of 130km or longer. In this paper, we present a summary of present GRACE studies for the recovery of hydrological signals in the Amazon basin using alternative processing and filtering techniques, and local inversion to enhance the temporal and spatial resolutions by two-folds or better. Simulation studies for the potential GRACE detection of slow deformations due to Nazca-South America plate convergence and glacial isostatic adjustment (GIA) signals show that these signals are at present difficult to detect without long-term data averaging and further improvement of GRACE measurement accuracy.

The Effect of PNF Method in Functional Restoration of Adult Hemiplegic Patients (PNF 치료가 성인 편마비 환자의 기능회복에 미치는 영향)

  • Bae, Sung-soo;Lee, Keun-heui;Hwang-bo, Gak
    • PNF and Movement
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    • 제3권1호
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    • pp.17-26
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    • 2005
  • Objectives : The purpose of this study is to identify influence that PNF method have an effect in function restoration of the impaired patients of central nervous system. Methods : The data were collected by 15 adult stroke patients. The treatment was based on proprioceptive neuromuscular facilitation techniques. Temporal and spatial parameters of gait were analysed for using the computerized GAITRite system. Results : In the comparison of functional ambulation profile(FAP) before and after experiment, the FAP was significantly increased in the PNF method. The gait velocity, cadence and single support time asymmetry ratio was significantly increased in the PNF method. The Motor Assessment Scale was significantly increased in the PNF method. Conclusions : Based on these results, it is concluded that the forced PNF method for 6 weeks can be improve the temporal-spatial gait parameters including FAP in hemiplegic patients. Therefore, the forced PNF method is useful to improve the function restoration in hemiplegic patients. Further study should be done to analyze the effects of intervention duration of treatment, optimal time to apply the treatment in more long peried.

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