• Title/Summary/Keyword: Spatial experiment

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Fabrication and evaluation of NSOM apparatus (NSOM장치의 제작 및 특성 평가)

  • ;A.K. Viswanath
    • Journal of the Korean Vacuum Society
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    • v.8 no.4B
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    • pp.530-535
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    • 1999
  • W made a near-field optical microscope(NSOM) apparatus and evaluated it. To control the distance between a tip and a sample, we used a piezoelectric translator and a He-Ne laser, and consequently obtained the spatial resolution better than 100nm. For the semiconductor spectroscopic applications, we performed photoluminescence and photocurrent experiments on the GaAs/AlGaAs MQWs samples. In the case of PL experiment, we obtained the low signal to nose ration due to the extremely small power of a light source passing through the nanometric optical fiber tip. However photocurrent experiment shows a hundred times better signal to noise than that of PL experiment. This suggests that photocurrent experiment using NSOM have the possibility to provide the spatial resolution better than 10nm.

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Assessing the Impacts of Errors in Coarse Scale Data on the Performance of Spatial Downscaling: An Experiment with Synthetic Satellite Precipitation Products

  • Kim, Yeseul;Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.33 no.4
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    • pp.445-454
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    • 2017
  • The performance of spatial downscaling models depends on the quality of input coarse scale products. Thus, the impact of intrinsic errors contained in coarse scale satellite products on predictive performance should be properly assessed in parallel with the development of advanced downscaling models. Such an assessment is the main objective of this paper. Based on a synthetic satellite precipitation product at a coarse scale generated from rain gauge data, two synthetic precipitation products with different amounts of error were generated and used as inputs for spatial downscaling. Geographically weighted regression, which typically has very high explanatory power, was selected as the trend component estimation model, and area-to-point kriging was applied for residual correction in the spatial downscaling experiment. When errors in the coarse scale product were greater, the trend component estimates were much more susceptible to errors. But residual correction could reduce the impact of the erroneous trend component estimates, which improved the predictive performance. However, residual correction could not improve predictive performance significantly when substantial errors were contained in the input coarse scale data. Therefore, the development of advanced spatial downscaling models should be focused on correction of intrinsic errors in the coarse scale satellite product if a priori error information could be available, rather than on the application of advanced regression models with high explanatory power.

Effects of Spatial Attention for Words on Implicit Memory (단어에 대한 공각적 주의가 암묵기억에 미치는 영향)

  • 심원목;김민식
    • Korean Journal of Cognitive Science
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    • v.11 no.3_4
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    • pp.13-22
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    • 2000
  • The present study examined the role of spatial attention in implicit memory for words when the word identity processing was not required. Spatial attention to the identity-irrelevant perceptual features of the words was manipulated by using a visual search task (Experiment 1) or a focused attention task (Experiment 2). In two e experiments. a significant priming effect was not found for the target words as well as for the distractor words. Implicit memory for words was not affected by spatial attention on the perceptual properties of the words. indicating that the word identity processing is required to produce priming.

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The Study of Particle Filter Localization Algorithm Based on Magnetic Field Data

  • Chang, Kun;Huang, He;Jing, Changfeng;Deng, Nanshan
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.2
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    • pp.107-112
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    • 2016
  • Most of the indoor positioning algorithms based on magnetic data mainly focus on reducing the accumulated error of the odometry data, such as signals produced by the inertial sensors. However, in most cases such as positioning by using smartphones in the indoor environment, those approaches seem unfeasible due to the absence of the inertial sensors. Thus, in this paper, we try to study a positioning algorithm exclusively based on the magnetic data. We refer to some thinking from the steps of Particle Filter and conduct an experiment to verify the application of the new algorithm. Besides, we use the variance of the result of the previous step to decrease the area to be matched in the next step, intending to improve the accuracy of the results. The result of the experiment shows that the new algorithm has a high probability to match with accuracy less than 2 meters in a 24 meters by 2.6 meters corridor.

The effect of error sources on the results of one-way nested ocean regional circulation model

  • Sy, Pham-Van;Hwang, Jin Hwan;Nguyen, Thi Hoang Thao;Kim, Bo-ram
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.253-253
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    • 2015
  • This research evaluated the effect of two main sources on the results of the ocean regional circulation model (ORCMs) during downscaling and nesting the results from the coarse data. The two sources should be the domain size, and temporal and spatial resolution different between driving and driven data. The Big-Brother Experiment is applied to examine the impact of them on the results of the ORCMs separately. Within resolution of 3km grid point ORCMs applying in the Big-Brother Experiment framework, it showed that the simulation results of the ORCMs depend on the domain size and specially the spatial and temporal resolution of lateral boundary conditions (LBCs). The domain size can be selected at 9.5 times larger than the interest area, and the spatial resolution between driving data and driven model can be up to 3 of ratio resolution and updating frequency of the LBCs can be up to every 6 hours per day.

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The Visual Properties of Built-Environment Affecting the Pattern of Human Movement - An Experimental Study Based on the Ecological Perception Theory - (인간 이동 행태에 영향을 미치는 건조 환경의 시각적 속성 - 생태학적 지각이론에 기반한 실험 연구 -)

  • Kim, Minseok
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.12
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    • pp.13-20
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    • 2019
  • The purpose of this study was to investigate the effects of visual properties on the human movement behavior experimentally and empirically using spatial analysis technique based on ecological perception theory. For the survey of choosing behaviors of heading direction in built environments, the experiment was conducted in which the subjects were made to choose moving directions in some spaces using the virtual environment simulation tool, and then comparative analysis was conducted on the interrelation between the experiment results and various visual properties in existing spatial analysis techniques based on ecological perception theory. As a result, the occlusivity of the isovist theory was found to be the most significant index in the human choice of heading direction, and the longest radial also showed somewhat significant effect on it.

The Effects of Gonjadaesungchimjoongbang on Learning Ability and Memory after Ischemic Brain Injury in Rats (허혈성 뇌손상 백서에서 공자대성침중방(孔子大聖枕中方)이 학습과 기억에 미치는 영향)

  • Ryu, Su-Hyang;Chae, Jung-Won
    • The Journal of Pediatrics of Korean Medicine
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    • v.25 no.1
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    • pp.40-48
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    • 2011
  • Objectives: The purpose of this study is to evaluate the effect of Gonjadaesungchimjoongbang on spatial learning abilities and memories in ischemic brain injury. Methods: Rats were separated into three groups; (1) Normal, (2) Saline medication after ischemic brain injuries (control), (3) Gonjadaesungchimjoongbang medication after ischemic brain injuries (experiment). Ischemic brain injuries was induced by MCA occlusion and reperfusion. Morris water maze test was conducted for spatial learning and memory tests. Then, the change of BDNF in the hippocampus($7^{th}$, $14^{th}$ day) was examined by immunohistoche- mistry. Results: In Morris water maze test, spatial learning abilities and memory functioning were considerably increased in the experiment group as oppose to control group on $7^{th}$ and $14^{th}$ day(p<0.01). Moreover, immunohistochemistric response of BDNF in the hippocampus indicated that the more increased immune reaction was found in the experiment group as oppose to the control group on $7^{th}$ and $14^{th}$ day. Conclusions: Gonjadaesungchimjoongbang can improve the learning abilities and memories in ischemic brain injury.

LDesign and implementation of a content-based image retrieval system using the duplicated color histogram and spatial information (중복된 칼라 히스토그램과 공간 정보를 이용한 내용 기반 화상 검색 시스템 설계 및 구현)

  • 김철원;최기호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.5
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    • pp.889-898
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    • 1997
  • Most general content-based image retrieval techniques use color and texture as retrieval indices. Spatial information is not used to color histogram and color pair based on color retrieval techniques. This paper proposes the selection of a set of representative in the duplicated color histogram, the analysis of spatial information of the selected colors and the image retrieval process based on the duplicated color histogram and spatial information. Two color historgrams for background and object are used in order to decide on color selection in the duplicated color histogram. Spatial information is obtained using a maximum entropy discretization. A retrieval process applies to duplicated color histogram and spatial to retrieve input images and relevant images. As the result of experiment of the image retrieval, improved color his togram and spatial information method hs increased the retrieval effectiveness more the color histogram method and color pair method.

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A Characteristic Value Extraction Method for Content-Based Image Retrieval using Morphological Spatial Frequency

  • Jinwoo Eo;Lee, Dongjin
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.42-45
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    • 2002
  • A novel characteristic value extraction method based on morphological spatial frequency is proposed. Morphological spatial frequency defined by morphological pattern distribution function is introduced. Superiority of the method was proved for various images by experiment. Furthermore the fact that the proposed method does not need threshold to obtain binary image provides its applicability to content-based image retrieval.

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Image Reconstruction of Dielectric Cylinder Under Born Approximation Using a Coherent Tomographic Scheme in the Spatial Domain (공간영역에서 코히어런트 단층촬영 기법을 이용한 Born 근사하에 유전체 기둥의 영상제현)

  • 서경환;김상기;김세윤;라정웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.9
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    • pp.1327-1335
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    • 1990
  • In this paper, using the principle of duality between the spatial and spectral domain, we proposed a new microwave imaging technique of a coherent tomographic formulation in the spatial domain and reconstructed the image of dielectric cylinder through simulation and experiment. The numerical and experimental results for the variety o object size, relative dielectric constant have shown the limitation of Born approximation to be used and the effect of retrieved images for various signal bandwidth.

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