Shashi Shekhar

A partial join approach for mining co-location patterns

Proceedings of the 12th annual ACM international workshop on Geographic information systems - GIS '04, 2004

Spatial co-location patterns represent the subsets of events whose instances are frequently locat... more Spatial co-location patterns represent the subsets of events whose instances are frequently located together in geographic space. We identified the computational bottleneck in the execution time of a current co-location mining algorithm. A large fraction of the join-based co-location miner algorithm is devoted to computing joins to identify instances of candidate co-location patterns. We propose a novel partialjoin approach for mining co-location patterns efficiently. It transactionizes continuous spatial data while keeping track of the spatial information not modeled by transactions. It uses a transaction-based Apriori algorithm as a building block and adopts the instance join method for residual instances not identified in transactions. We show that the algorithm is correct and complete in finding all co-location rules which have prevalence and conditional probability above the given thresholds. An experimental evaluation using synthetic datasets and a real dataset shows that our algorithm is computationally more efficient than the join-based algorithm.

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Path computation algorithms for advanced traveller information system (ATIS)

Proceedings of IEEE 9th International Conference on Data Engineering

Key Words: Advanced applications, performance studies, databases. ... 1.1. Route Computations in ... more

Data Compression

Encyclopedia of GIS, 2008

This paper surveys a variety of data compression methods spanning almost 40 years of research, fr... more This paper surveys a variety of data compression methods spanning almost 40 years of research, from the work of Shannon, Fano, and Huffman in the late 1940s to a technique developed in 1986. The aim of data compression is to reduce redundancy in stored or communicated data, thus increasing effective data density. Data compression has important application in the areas of file storage and distributed systems. Concepts from information theory as they relate to the goals and evaluation of data compression methods are discussed briefly. A framework for evaluation and comparison of methods is constructed and applied to the algorithms presented. Comparisons of both theoretical and empirical natures are reported, and possibilities for future research are suggested

format_quoteData compression using Huffman coding achieved a 42.1% database size reduction and a 32.7% decrease in disk operations.format_quote

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Reference-Feature Centric

Encyclopedia of GIS, 2008

An Intelligent Vehicle Highway Information Management System

Computer-Aided Civil and Infrastructure Engineering, 2008

Abstract: An IVHS (Intelligent Vehicle Highway System) information management system obtains info... more

Development of clay ferrite nanocomposite: Electrochemical, sensors and photocatalytic studies

Applied Surface Science Advances, 2021

Nano ferrite bentonite clay composite (NFBC) is synthesized in this present work by using mangane... more Nano ferrite bentonite clay composite (NFBC) is synthesized in this present work by using manganese (Mn) recovered from waste batteries, ferric nitrate and citric acid prepared by simple and cost-effective Indian sodium bentonite nanoclay (Na-IB) by sol-gel process and by using X-ray diffractrometer (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) Spectroscopy, Energy dispersive Spectroscope (EDS) characterized nanoparticles. The result shows that NFBC is sufficient for the excellent performance of AO dye photocatalytic degradation (98 %). Electrochemical study of prepared material with graphite electrode paste in 0.1 M KCl electrolyte showed excellent redox potential output as calculated by cyclic voltammetry and expanded its sensor activities to biochemical (Dextrose). We examined the efficacy of NFBC in the detection of Dextrose from an aqueous solution and compared the results with pristine MnFe 2 O 4 NPs.

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