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104
Multidimensional Access Methods
, 1998
"... Search operations in databases require special support at the physical level. This is true for conventional databases as well as spatial databases, where typical search operations include the point query (find all objects that contain a given search point) and the region query (find all objects that ..."
Abstract

Cited by 563 (3 self)
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Search operations in databases require special support at the physical level. This is true for conventional databases as well as spatial databases, where typical search operations include the point query (find all objects that contain a given search point) and the region query (find all objects that overlap a given search region). More
A Quantitative Analysis and Performance Study for SimilaritySearch Methods in HighDimensional Spaces
, 1998
"... For similarity search in highdimensional vector spaces (or `HDVSs'), researchers have proposed a number of new methods (or adaptations of existing methods) based, in the main, on dataspace partitioning. However, the performance of these methods generally degrades as dimensionality increases. Altho ..."
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Cited by 495 (12 self)
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For similarity search in highdimensional vector spaces (or `HDVSs'), researchers have proposed a number of new methods (or adaptations of existing methods) based, in the main, on dataspace partitioning. However, the performance of these methods generally degrades as dimensionality increases. Although this phenomenonknown as the `dimensional curse'is well known, little or no quantitative analysis of the phenomenon is available. In this paper, we provide a detailed analysis of partitioning and clustering techniques for similarity search in HDVSs. We show formally that these methods exhibit linear complexity at high dimensionality, and that existing methods are outperformed on average by a simple sequential scan if the number of dimensions exceeds around 10. Consequently, we come up with an alternative organization based on approximations to make the unavoidable sequential scan as fast as possible. We describe a simple vector approximation scheme, called VAfile, and report on an ...
Locally weighted learning
 ARTIFICIAL INTELLIGENCE REVIEW
, 1997
"... This paper surveys locally weighted learning, a form of lazy learning and memorybased learning, and focuses on locally weighted linear regression. The survey discusses distance functions, smoothing parameters, weighting functions, local model structures, regularization of the estimates and bias, ass ..."
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Cited by 453 (52 self)
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This paper surveys locally weighted learning, a form of lazy learning and memorybased learning, and focuses on locally weighted linear regression. The survey discusses distance functions, smoothing parameters, weighting functions, local model structures, regularization of the estimates and bias, assessing predictions, handling noisy data and outliers, improving the quality of predictions by tuning t parameters, interference between old and new data, implementing locally weighted learning e ciently, and applications of locally weighted learning. A companion paper surveys how locally weighted learning can be used in robot learning and control.
The quadtree and related hierarchical data structures
 ACM Computing Surveys
, 1984
"... A tutorial survey is presented of the quadtree and related hierarchical data structures. They are based on the principle of recursive decomposition. The emphasis is on the representation of data used in applications in image processing, computer graphics, geographic information systems, and robotics ..."
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Cited by 423 (11 self)
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A tutorial survey is presented of the quadtree and related hierarchical data structures. They are based on the principle of recursive decomposition. The emphasis is on the representation of data used in applications in image processing, computer graphics, geographic information systems, and robotics. There is a greater emphasis on region data (i.e., twodimensional shapes) and to a lesser extent on point, curvilinear, and threedimensional data. A number of operations in which such data structures find use are examined in greater detail.
Tree visualization with Treemaps: A 2d spacefilling approach
 ACM Transactions on Graphics
, 1991
"... this paper deals with a twodimensional (2d) spacefilling approach in which each node is a rectangle whose area is proportional to some attribute such as node size. Research on relationships between 2d images and their representation in tree structures has focussed on node and link representation ..."
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Cited by 393 (22 self)
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this paper deals with a twodimensional (2d) spacefilling approach in which each node is a rectangle whose area is proportional to some attribute such as node size. Research on relationships between 2d images and their representation in tree structures has focussed on node and link representations of 2d images. This work includes quadtrees (Samet, 1989) and their variants which are important in image processing. The goal of quad trees is to provide a tree representation for storage compression and efficient operations on bitmapped images. XYtrees (Nagy & Seth, 1984) are a traditional tree representation of twodimensional layouts found in newspaper, magazine, or book pages. Related concepts include kd trees (Bentley and Freidman, 1979), which are often explained with the help of a
Dynamic Queries for Visual Information Seeking
 IEEE Software
, 1994
"... Dynamic queries are a novel approach to information seeking that may enable users to cope with information overload. They allow users to see an overview of the database, rapidly (100 msec updates) explore and conveniently filter out unwanted information. Users fly through information spaces by incre ..."
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Cited by 239 (32 self)
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Dynamic queries are a novel approach to information seeking that may enable users to cope with information overload. They allow users to see an overview of the database, rapidly (100 msec updates) explore and conveniently filter out unwanted information. Users fly through information spaces by incrementally adjusting a query (with sliders, buttons, and other filters) while continuously viewing the changing results. Dynamic queries on the chemical table of elements, computer directories, and a real estate database were built and tested in three separate exploratory experiments. These results show statistically significant performance improvements and user enthusiasm more commonly seen with video games. Widespread application seems possible but research issues remain in database and display algorithms, and user interface design. Challenges include methods for rapidly displaying and changing many points, colors, and areas; multidimensional pointing; incorporation of sound and visual displ...
Query optimization in database systems
 ACM Computing Surveys
, 1984
"... Efficient methods of processing unanticipated queries are a crucial prerequisite for the success of generalized database management systems. A wide variety of approaches to improve the performance of query evaluation algorithms have been proposed: logicbased and semantic transformations, fast imple ..."
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Cited by 207 (0 self)
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Efficient methods of processing unanticipated queries are a crucial prerequisite for the success of generalized database management systems. A wide variety of approaches to improve the performance of query evaluation algorithms have been proposed: logicbased and semantic transformations, fast implementations of basic operations, and combinatorial or heuristic algorithms for generating alternative access plans and choosing among them. These methods are presented in the framework of a general query evaluation procedure using the relational calculus representation of queries. In addition, nonstandard query optimization issues such as higher level query evaluation, query optimization in distributed databases, and use of database machines are addressed. The focus, however, is on query optimization in centralized database systems.
Color image quantization for frame buffer display
 Computer Graphics
, 1982
"... Algorithms for approximately optimal quantization of color images are discussed. The distortion measure used is the distance in RGB space. These algorithms are used to compute the color map for lowdepth frame buffers in order to allow highquality static images to be displayed. It is demonstrated t ..."
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Cited by 140 (0 self)
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Algorithms for approximately optimal quantization of color images are discussed. The distortion measure used is the distance in RGB space. These algorithms are used to compute the color map for lowdepth frame buffers in order to allow highquality static images to be displayed. It is demonstrated that most color images can be very well displayed using only 256 or 512 colors. Thus frame buffers of only 8 or 9 bits can display images that normally require 15 bits or more per pixel. Work reported herein was sponsored by the IBM Corporation though a general grant agreement to MIT dated July 1, 1979.  TABLE OF CONTENTS page I. Introduction ............................................. 4 II. Frame Buffers and Colormaps .............................. 6 III. 1Dimensional Tapered Quantization .......................17 IV. 3Dimensional Tapered Quantization .......................27 V. Conclusions and Ideas for Further Study .......
A Simple Algorithm for Nearest Neighbor Search in High Dimensions
 IEEE Transactions on Pattern Analysis and Machine Intelligence
, 1997
"... Abstract—The problem of finding the closest point in highdimensional spaces is common in pattern recognition. Unfortunately, the complexity of most existing search algorithms, such as kd tree and Rtree, grows exponentially with dimension, making them impractical for dimensionality above 15. In ne ..."
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Cited by 126 (1 self)
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Abstract—The problem of finding the closest point in highdimensional spaces is common in pattern recognition. Unfortunately, the complexity of most existing search algorithms, such as kd tree and Rtree, grows exponentially with dimension, making them impractical for dimensionality above 15. In nearly all applications, the closest point is of interest only if it lies within a userspecified distance e. We present a simple and practical algorithm to efficiently search for the nearest neighbor within Euclidean distance e. The use of projection search combined with a novel data structure dramatically improves performance in high dimensions. A complexity analysis is presented which helps to automatically determine e in structured problems. A comprehensive set of benchmarks clearly shows the superiority of the proposed algorithm for a variety of structured and unstructured search problems. Object recognition is demonstrated as an example application. The simplicity of the algorithm makes it possible to construct an inexpensive hardware search engine which can be 100 times faster than its software equivalent. A C++ implementation of our algorithm is available upon request to search@cs.columbia.edu/CAVE/.
Optimal expectedtime algorithms for closest point problems
 ACM Transactions of Mathematical Software
, 1980
"... Geometric closest potnt problems deal with the proxLmity relationships in kdimensional point sets. Examples of closest point problems include building minimum spanning trees, nearest neighbor searching, and triangulation constructmn Shamos and Hoey [17] have shown how the Voronoi dtagram can be use ..."
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Cited by 88 (0 self)
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Geometric closest potnt problems deal with the proxLmity relationships in kdimensional point sets. Examples of closest point problems include building minimum spanning trees, nearest neighbor searching, and triangulation constructmn Shamos and Hoey [17] have shown how the Voronoi dtagram can be used to solve a number of planar closest point problems in optimal worst case tune. In this paper we extend thmr work by giving optimal expected.trine algorithms for solving a number of closest point problems in kspace, including nearest neighbor searching, finding all nearest neighbors, and computing planar minimum spanning trees. In addition to establishing theoretical bounds, the algorithms in this paper can be implemented to solve practical problems very efficiently. Key Words and Phrases ' computational geometry, closest point problems, minunum spanning trees, nearest neighbor searching, optimal algorithms, probabfllstm analysis of algorithms, Voronoi diagrams CR Categories: 3.74, 5 25, 5.31, 5.32 1.