The Experts below are selected from a list of 162945 Experts worldwide ranked by ideXlab platform

Zhu Ling - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Target Properties on Terrestrial Laser Scanning Intensity Data
    Proceedings of the 2013 International Conference on Remote Sensing Environment and Transportation Engineering, 2013
    Co-Authors: Cang Guihua, Li Mingfeng, Yue Jianping, Ou Jiangxia, Zhu Ling
    Abstract:

    Terrestrial laser Scanning (TLS) Intensity data are influenced by many factors. In this paper, the influence of target surface properties on TLS Intensity data is considered. Experiments were carried out with standard reflector, some different color plates and selected building facades of various kind of material. Through the research on the Intensity quality, we can conclude that the target reflectance characteristics at the laser wavelength determine its Intensity Value. Two correlations, that is, Intensity Value and range accuracy, Intensity Value and its standard deviation are not the same for different targets. Color has a great impact on the Intensity of scanned point data. The white, yellow, cyan and green plates have large Intensity with a better reflectivity at green laser, while red and black have small Intensity with worse reflectivity. Keywords—Terrestrial Laser Scanning, target surface properties, Intensity data, point cloud, effect analysis

  • Application of weighted total least squares based on Intensity Value in plane fitting of point clouds
    Proceedings of the 2013 International Conference on Remote Sensing Environment and Transportation Engineering, 2013
    Co-Authors: Cang Guihua, Li Mingfeng, Ou Jiangxia, Zhu Ling
    Abstract:

    Aiming at the condition that each point in point clouds has different positional accuracy, a new method for fitting plane to point clouds is proposed. The method is based on weighted total least squares (WTLS). According to the effect of Intensity of each point on positional accuracy and the structure of coefficient matrix, the weight matrix was defined. In order to verify the applicability of the proposed method, analytical experiments based on instant data of different materials were done, and comparisons between the method and traditional methods, such as least squares (LS) method and total least squares (TLS) method were implemented. The results show that the method is suitable for fitting plane to point clouds with good homogeneity, and more accurate parameters solution can be obtained as compared with TLS and LS. As for point clouds with poor homogeneity, the proposed method is unsuitable for the same operational use, while TLS is the most effective method. Keywords—point clouds, weighted total least-squares, Intensity Value, weight matrix, plane fitting

Hifzi Arda Ersan - One of the best experts on this subject based on the ideXlab platform.

  • numerical simulation of turbulent airflow in a ventilated room inlet turbulence parameters and solution multiplicity
    Energy and Buildings, 2015
    Co-Authors: Erhan Pulat, Hifzi Arda Ersan
    Abstract:

    Abstract In this study, airflow and temperature distributions in the well-known International Energy Agency (IEA) Annex 20 room are predicted numerically to investigate the effects of the inlet turbulence Intensity and the length scale on the flow characteristics, while considering the possibility of solution multiplicity related to chaos theory. The flow is considered to be turbulent, steady, incompressible, and two-dimensional. Computations are performed using the standard k–ɛ, RNG k–ɛ, standard k–ω, and shear stress transport k–ω turbulence models with scalable and automatic wall functions, and the results are compared with numerical and experimental results from the literature. The validated turbulence model is then used to investigate the effects of the turbulence Intensity and the length scale. At a low inlet turbulence Intensity Value (Tu = 0.01), the length scale variation has no influence on the flow pattern. However, the length scale affects the flow pattern at a high inlet turbulence Intensity Value (Tu = 0.4). At constant low and medium length scale Values, an increase in the inlet turbulence Intensity from 0.01 to 0.4 affects the flow pattern. However, an increase in the turbulence Intensity has no influence on the flow pattern at a constant high length scale Value.

P. Meyer - One of the best experts on this subject based on the ideXlab platform.

  • Segmentation and symbolic description for a classification of agricultural areas with multispectral scanner data
    IEEE Transactions on Geoscience and Remote Sensing, 1992
    Co-Authors: P. Meyer
    Abstract:

    A procedure that overcomes some of the disadvantages of conventional pixel-based classification is proposed. Several methods for data preprocessing are tested, and the edge-preserving smoothing filter is found to give the best results. The segmentation module uses an easy and efficient region-based algorithm based on a comparison of the Intensity Value of a single pixel in the 4- or 8-adjacency neighborhood. This algorithm discriminates 97% of the regions in the test area and shows in some selected regions a mean area deviation of 7.8%. Within the symbolic description, 127 attributes of morphologic and internal descriptors are tested on four main criteria. It is shown that the selection of the descriptors has to be done in consideration of the data as well as the application.

Cang Guihua - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Target Properties on Terrestrial Laser Scanning Intensity Data
    Proceedings of the 2013 International Conference on Remote Sensing Environment and Transportation Engineering, 2013
    Co-Authors: Cang Guihua, Li Mingfeng, Yue Jianping, Ou Jiangxia, Zhu Ling
    Abstract:

    Terrestrial laser Scanning (TLS) Intensity data are influenced by many factors. In this paper, the influence of target surface properties on TLS Intensity data is considered. Experiments were carried out with standard reflector, some different color plates and selected building facades of various kind of material. Through the research on the Intensity quality, we can conclude that the target reflectance characteristics at the laser wavelength determine its Intensity Value. Two correlations, that is, Intensity Value and range accuracy, Intensity Value and its standard deviation are not the same for different targets. Color has a great impact on the Intensity of scanned point data. The white, yellow, cyan and green plates have large Intensity with a better reflectivity at green laser, while red and black have small Intensity with worse reflectivity. Keywords—Terrestrial Laser Scanning, target surface properties, Intensity data, point cloud, effect analysis

  • Application of weighted total least squares based on Intensity Value in plane fitting of point clouds
    Proceedings of the 2013 International Conference on Remote Sensing Environment and Transportation Engineering, 2013
    Co-Authors: Cang Guihua, Li Mingfeng, Ou Jiangxia, Zhu Ling
    Abstract:

    Aiming at the condition that each point in point clouds has different positional accuracy, a new method for fitting plane to point clouds is proposed. The method is based on weighted total least squares (WTLS). According to the effect of Intensity of each point on positional accuracy and the structure of coefficient matrix, the weight matrix was defined. In order to verify the applicability of the proposed method, analytical experiments based on instant data of different materials were done, and comparisons between the method and traditional methods, such as least squares (LS) method and total least squares (TLS) method were implemented. The results show that the method is suitable for fitting plane to point clouds with good homogeneity, and more accurate parameters solution can be obtained as compared with TLS and LS. As for point clouds with poor homogeneity, the proposed method is unsuitable for the same operational use, while TLS is the most effective method. Keywords—point clouds, weighted total least-squares, Intensity Value, weight matrix, plane fitting

Arpita Baronia - One of the best experts on this subject based on the ideXlab platform.

  • an efficient image denoising approach to remove random Valued impulse noise by truncating data inside sliding window
    International Conference on Data Engineering, 2020
    Co-Authors: Satrughan Kumar, Jigyendra Sen Yadav, Yashwant Kurmi, Arpita Baronia
    Abstract:

    Random impulse noise disrupts the homogeneity of the image and deteriorates the other features such as edges, layer depth and sharpness. To alleviate this problem, this paper presents a new algorithm that detects and removes the random Valued impulse noise by devising the local statistics inside the sliding window. The corrupt pixel is identified by examining the data under the current window using Gaussian probability distribution function. Meanwhile, the median of the entire data and the mean Value of truncated data inside the current window estimates the optimum Intensity Value at the position where the pixel is disrupted by noise. Simulations show that the proposed method effectively reduces the noise at various level of noise density and yields a better Intensity estimate in restored image.