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A FAST SEARCH ALGORITHM ON MODIFIED S-TREES

PATTERN RECOGNITION LETTERS 1995年第11期16卷 1159-1164页

作者： CHUNG, KL WU, CJ Department of Information Management National Taiwan Institute of Technology No. 43 Section 4. Keelung Road Taipei. Taiwan 10672 ROC

We first propose a modified S-tree. Let the memory required in the modified S-tree be O(m), then our derived fast search algorithm can be performed in O(t) time, t less than or equal to m. Our algorithm is quite competitive with the algorithm of Jonge, Scheuermann, and Schijf (1994). The application to pictorial database is also addressed.

关键词： spatial data structure S-TREE MODIFIED S-TREE IMAGE PROCESSING SEARCH ALGORITHM PICTORIAL dataBASE

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Binary volume rendering using slice-based binary shell

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VISUAL COMPUTER 2001年第4期17卷 243-257页

作者： Kim, BH Seo, J Shin, YG Seoul Natl Univ Sch Comp Sci & Engn Seoul 151742 South Korea Univ Maryland Dept Comp Sci College Pk MD 20770 USA

This paper presents a new data structure, Slice-based Binary Shell (SBS), for efficient manipulation and rendering of binary volume data. Since SBS stores only surface voxels with selected attributes of the voxels in a slice-based data structure that allows direct access to the voxels, it shows high storage and computational efficiency. This efficiency becomes more prominent when representing multiple binary objects. We also present an efficient rendering algorithm for SBS. The algorithm, based on the shear-warp technique, provides high-speed interactive rendering for binary volumes of many objects on a PC with no specialized hardware.

关键词： binary volume rendering surface voxel spatial data structure medical imaging

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Soil heterogeneity characterization using PCA (X_variogram) - Multivariate analysis of spatial signatures for optimal sampling purposes

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CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS 2014年 136卷 24-35页

作者： Kardanpour, Zahra. Jacobsen, Ole Stig Esbensen, Kim H. Geol Survey Denmark & Greenland GEUS Copenhagen Denmark Aalborg Univ ACABS Res Grp Aalborg Denmark Telemark Univ Coll Porsgrunn Norway

This study explores how to combine variographic spatial characterization with multivariate data analysis, by showing how Principal Component Analysis (PCA) can be applied to unconventional types of data matrices, X-variogram. This is here performed on a specific data set from an agricultural field in western Jutland, Denmark, but the data analytical approach is generic. In order to characterize the heterogeneity of a typical sandy soil, a variographic experiment along a 1-D profile is performed on 38 different minerogenic variables (geochemical elements). While the variogram is defined for one variable only, it is shown how PCA is able to characterize a multitude of variograms simultaneously, facilitating subject-matter interpretation of the fingerprints of the process(es) responsible for the spatial heterogeneity encountered. PCA scores and loadings contain information pertaining to the specific matrix type consisting of variograms, X-variogram. Together with a companion paper, a complete approach for characterizing scale-varying spatial heterogeneity is presented with a view of developing sampling procedures for managing the intrinsic variability in natural soil and in similar systems (e.g. environmental characterization and monitoring, pollution in time and space, applied geochemistry, medical geology). Sampling in all of these contexts is shown to be much more than a 'materials handling' issue, by force involving the Theory of Sampling, TOS. The PCA (X-variogram) approach can be applied for tuning in of sampling procedures and 1-D and 2-D sampling plans in soil, environmental substrates, pollution and medical geology studies with a carrying-over potential to many other application fields with similar heterogeneity management needs. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Variogram Heterogeneity characterization Heterogeneity management Scale dependency Representative sampling spatial data structure Fate studies

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Efficient regular data structures and algorithms for dilation, location, and proximity problems

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ALGORITHMICA 2001年第2期30卷 164-187页

作者： Amir, A Efrat, A Indyk, P Samet, H IBM Corp Almaden Res Ctr San Jose CA 95120 USA Univ Arizona Dept Comp Sci Tucson AZ 85721 USA MIT Cambridge MA 02139 USA Univ Maryland Dept Comp Sci College Pk MD 20742 USA

In this paper we investigate data structures obtained by a recursive partitioning of the multidimensional input domain into regions of equal size. One of the best known examples of such a structure is the quadtree. It is used here as a basis for more complex data structures. We also provide multidimensional versions of the stratified tree by van Emde Boas [VEB]. We show that under the assumption that the input points have limited precision (i.e., are drawn from the integer grid of size u) these data structures yield efficient solutions to many important problems. In particular, they allow us to achieve O (log log u) time per operation for dynamic approximate nearest neighbor (under insertions and deletions) and exact on-line closest pair (under insertions only) in any constant number of dimensions. They allow O (log log u) point location in a given planar shape or in its expansion (dilation by a ball of a given radius). Finally, we provide a linear time (optimal) algorithm for computing the expansion of a shape represented by a region quadtree, This result shows that the spatial order imposed by this regular data structure is sufficient to optimize the operation of dilation by a ball.

关键词： quadtree dilation approximate nearest neighbor point location multidimensional stratified trees spatial data structure

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Fast implementations for mirroring and rotating bincode-based images

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PATTERN RECOGNITION 1998年第12期31卷 1961-1967页

作者： Chung, KL Wu, JG Natl Taiwan Univ Sci & Technol Dept Informat Management Taipei 10672 Taiwan Natl Taiwan Univ Sci & Technol Grad Program Informat Engn Taipei 10672 Taiwan Natl Taiwan Normal Univ Dept Informat & Comp Educ Taipei 10610 Taiwan

The spatial data structure known as bincode is a simple and storage-saving encoding scheme for representing binary images. In this paper, we first present eight efficient operations for mirroring and rotating bincode-based images. Among the operations, certain special operations on individual bits within bincodes are needed. Then we present a newly proposed logical representation for implementing the bitwise operations in the operations. Finally, we implement the bitwise operations in hardware to speed up the special manipulations. (C) 1998 Pattern Recognition Society. Published by Elsevier Science. All rights reserved.

关键词： logical operations bincodes mirroring and rotating operations spatial data structure hardware implementation

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The comparison map profile method:: A strategy for multiscale comparison of quantitative and qualitative images

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2008年第9期46卷 2708-2719页

作者： Gaucherel, Cedric Alleaume, Samuel Hely, Christelle Aix Marseille Univ CNRS CDF IRDCEREGE F-13545 Aix En Provence France

The comparison map profile (CMP) method compares two spatially explicit data sets (original images) at each point and through several spatial scales simultaneously. The CMP combines the moving window concept with similarity indices for quantitative or qualitative data to visualize and quantify outputs: Changes in mean similarity value and its variability through scales are reported on a profile, similarities between regions are estimated on monoscale maps, and their persistence through scales assessed on a mean multiscale map. The CMP method is first illustrated using two images with slight difference in the checkered pattern. Second, two sets of comparisons related to African vegetation are conducted using the CMP method. The first set deals with quantitative data of leaf area index (LAI): Remote-sensed LAI images extracted from the AVHRR-NVDI product are compared to simulated LAI output from a dynamic global vegetation model DGVM) using the distance and the cross-correlational coefficient for quantitative comparison of values and structure patterns, respectively,. The second set of images deals with qualitative data: the remote-sensed product of land cover type by IGBP-NIODIS is compared to the DGVM classified LAI output into land cover types using the Kappa statistics as similarity index. Results show that taking spatial patterns into account using the CMP method decreases the mean correlation by 50%, and increases the distance by 50% as compared to the global pixel-to-pixel indices. Similarly, comparison of land cover maps costs only 35% of the global Kappa value. Equatorial gradients of vegetation from forests to grassland are the most persistent similar regions between both types of data sets. Potential limits and strengths of the CMP method are discussed.

关键词： environmental factors image texture analysis spatial data structure vegetation mapping

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Large encrypting binary images with higher security

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PATTERN RECOGNITION LETTERS 1998年第5-6期19卷 461-468页

作者： Chung, KL Chang, LC Natl Taiwan Univ Sci & Technol Dept Informat Management Taipei 10672 Taiwan Natl Taiwan Univ Sci & Technol Grad Program Informat Engn Taipei 10672 Taiwan

In this paper, we present a new approach for encrypting binary images. Putting different scan patterns at the same level in the scan tree structure and employing a two-dimensional run-encoding (2DRE) technique, our encryption method can encrypt images with higher security and good compression ratio when compared to the previous results. Detailed security analysis from the combinatorial viewpoint is also given. Some experimentations are carried out to illustrate the good performance of our proposed method. (C) 1998 Elsevier Science B.V. All rights reserved.

关键词： image encryption run-length compression security SCAN language spatial data structure

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An efficient surface-surface intersection algorithm using adaptive surface triangulations and space partitioning trees

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MATHEMATICAL ENGINEERING IN INDUSTRY 1998年第1期7卷 25-40页

作者： Jean, BA Hamann, B USA Waterways Expt Stn Ctr High Performance Comp CEWES IH Vicksburg MS 39180 USA Univ Calif Davis Dept Comp Sci Davis CA 95616 USA Univ Calif Davis Ctr Image Proc & Integrated Computing Davis CA 95616 USA

We present a robust and efficient surface-surface intersection (SSI) algorithm. The algorithm is based on intersecting surface triangulations and improves the resulting linear spline curve approximations of the exact intersection curves by replacing intersection points of the surface triangulations by exact intersection points. We use a specialized data structure, the k-d tree, for the efficient intersection of surface triangulations. The resulting intersection curves are guaranteed to lie within a user-specified tolerance.

关键词： approximation Bezier surface B-spline surface k-d tree NURBS surface parametric surface spatial data structure surface-surface intersection surface triangulation trimmed surfaces

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Branch grafting method for R-tree implementation

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JOURNAL OF SYSTEMS AND SOFTWARE 2000年第1期53卷 83-93页

作者： Schreck, T Chen, Z Univ Nebraska Dept Comp Sci Omaha NE 68182 USA

R-trees are an important spatial data structure for database storage. In this paper, we introduce a new method, called branch grafting method, for R-tree implementation. The major motivation of this proposed technique is to produce more desirable result and to reduce the number of nodes created in the R-tree. We present this method by comparing it with reinsertion method as used in R*-tree. Experiments have been carried out, and the strength of this proposed method is outlined. (C) 2000 Elsevier Science inc. All rights reserved.

关键词： R-tree implementation spatial data structure data mining branch grafting

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Efficient Space Management Techniques for Large-Scale Interconnect Capacitance Extraction With Floating Random Walks

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IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS 2013年第10期32卷 1633-1637页

作者： Zhang, Chao Yu, Wenjian Tsinghua Univ Dept Comp Sci & Technol Beijing 100084 Peoples R China

In the capacitance extraction with the floating random walk (FRW) algorithm, the space management approach is required to facilitate finding the nearest conductor. The Octree and grid-based spatial structures have been used to decompose the whole domain into cells and to store information of local conductors. In this letter, the techniques with the distance limit of cell and only searching in cell's neighbor region are proposed to accelerate the construction of the spatial structures. A fast inquiry technique is proposed to fasten the nearest conductor query. We also propose a grid-Octree hybrid structure, which has advantages over existing structures. Experiments on large very large scale integration structures with up to 484 441 conductors have validated the efficiency of the proposed techniques. The improved FRW algorithm is faster than RWCap for thousands times while extracting a single net, and several to tens times while extracting 100 nets.

关键词： Capacitance extraction floating random walk (FRW) space management spatial data structure very large scale integration (VLSI) circuit

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