External Memory Algorithms for Shortest Distance and Spatio-temporal Queries on Road Network

External Memory Algorithms for Shortest Distance and Spatio-temporal Queries on Road Network PDF Author: Sandeep Kumar Gupta
Publisher:
ISBN:
Category : Global Positioning System
Languages : en
Pages : 352

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External Memory Algorithms for Shortest Distance and Spatio-temporal Queries on Road Network

External Memory Algorithms for Shortest Distance and Spatio-temporal Queries on Road Network PDF Author: Sandeep Kumar Gupta
Publisher:
ISBN:
Category : Global Positioning System
Languages : en
Pages : 352

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Book Description


Shortest Path Queries in Very Large Spatial Databases [electronic Resource]

Shortest Path Queries in Very Large Spatial Databases [electronic Resource] PDF Author: Zhang, Ning
Publisher: University of Waterloo
ISBN:
Category :
Languages : en
Pages :

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Book Description
Finding the shortest paths in a graph has been studied for a long time, and there are many main memory based algorithms dealing with this problem. Among these, Dijkstra's shortest path algorithm is one of the most commonly used efficient algorithms to the non-negative graphs. Even more efficient algorithms have been developed recently for graphs with particular properties such as the weights of edges fall into a range of integer. All of the mentioned algorithms require the graph totally reside in the main memory. Howevery, for very large graphs, such as the digital maps managed by Geographic Information Systems (GIS), the requirement cannot be satisfied in most cases, so the algorithms mentioned above are not appropriate. My objective in this thesis is to design and evaluate the performance of external memory (disk-based) shortest path algorithms and data structures to solve the shortest path problem in very large digital maps. In particular the following questions are studied: What have other researchers done on the shortest path queries in very large digital maps? What could be improved on the previous works? How efficient are our new shortest paths algorithms on the digital maps, and what factors affect the efficiency? What can be done based on the algorithm? In this thesis, we give a disk-based Dijkstra's-like algorithm to answer shortest path queries based on pre-processing information. Experiments based on our Java implementation are given to show what factors affect the running time of our algorithms.

Advances in Spatial and Temporal Databases

Advances in Spatial and Temporal Databases PDF Author: Dieter Pfoser
Publisher: Springer
ISBN: 3642229220
Category : Computers
Languages : en
Pages : 531

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Book Description
This volume constitutes the refereed proceedings of the 12th International Symposium on Spatial and Temporal Databases, SSTD 2011, held in Minneapolis, USA, in August 2011. The 24 revised full papers presented together with one keynote, 8 short papers, and 8 demonstration papers, were thoroughly reviewed and selected from a total of 63 research submissions, 21 vision and challenges submissions and 16 demonstration submissions. The papers are organized in topical sections on knowledge discovery; spatial networks; access methods; moving objects and sensor networks; multidimensional query processing; and temporal and streaming data.

Algorithms and Data Structures for External Memory

Algorithms and Data Structures for External Memory PDF Author: Jeffrey Scott Vitter
Publisher: Now Publishers Inc
ISBN: 1601981066
Category : Computers
Languages : en
Pages : 192

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Book Description
Describes several useful paradigms for the design and implementation of efficient external memory (EM) algorithms and data structures. The problem domains considered include sorting, permuting, FFT, scientific computing, computational geometry, graphs, databases, geographic information systems, and text and string processing.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 924

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Evaluation of Shortest Path Query Algorithm in Spatial Databases [electronic Resource]

Evaluation of Shortest Path Query Algorithm in Spatial Databases [electronic Resource] PDF Author: Lim, Heechul
Publisher: University of Waterloo
ISBN:
Category :
Languages : en
Pages :

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Book Description
Many variations of algorithms for finding the shortest path in a large graph have been introduced recently due to the needs of applications like the Geographic Information System (GIS) or Intelligent Transportation System (ITS). The primary subjects of those algorithms are materialization and hierarchical path views. Some studies focus on the materialization and sacrifice the pre-computational costs and storage costs for faster computation of a query. Other studies focus on the shortest-path algorithm, which has less pre-computation and storage but takes more time to compute the shortest path. The main objective of this thesis is to accelerate the computation time for the shortest-path queries while keeping the degree of materialization as low as possible. This thesis explores two different categories: 1) the reduction of the I/O-costs for multiple queries, and 2) the reduction of search spaces in a graph. The thesis proposes two simple algorithms to reduce the I/O-costs, especially for multiple queries. To tackle the problem of reducing search spaces, we give two different levels of materializations, namely, the boundary set distance matrix and x-Hop sketch graph, both of which materialize the shortest-path view of the boundary nodes in a partitioned graph. Our experiments show that a combination of the suggested solutions for 1) and 2) performs better than the original Disk-based SP algorithm [7], on which our work is based, and requires much less storage than HEPV [3].

Temporal GIS

Temporal GIS PDF Author: George Christakos
Publisher: Springer Science & Business Media
ISBN: 3642565409
Category : Mathematics
Languages : en
Pages : 225

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Book Description
The book focuses on the development of advanced functions for field-based temporal geographical information systems (TGIS). These fields describe natural, epidemiological, economical, and social phenomena distributed across space and time. The book is organized around four main themes: "Concepts, mathematical tools, computer programs, and applications". Chapters I and II review the conceptual framework of the modern TGIS and introduce the fundamental ideas of spatiotemporal modelling. Chapter III discusses issues of knowledge synthesis and integration. Chapter IV presents state-of-the-art mathematical tools of spatiotemporal mapping. Links between existing TGIS techniques and the modern Bayesian maximum entropy (BME) method offer significant improvements in the advanced TGIS functions. Comparisons are made between the proposed functions and various other techniques (e.g., Kriging, and Kalman-Bucy filters). Chapter V analyzes the interpretive features of the advanced TGIS functions, establishing correspondence between the natural system and the formal mathematics which describe it. In Chapters IV and V one can also find interesting extensions of TGIS functions (e.g., non-Bayesian connectives and Fisher information measures). Chapters VI and VII familiarize the reader with the TGIS toolbox and the associated library of comprehensive computer programs. Chapter VIII discusses important applications of TGIS in the context of scientific hypothesis testing, explanation, and decision making.

Geocomputation with R

Geocomputation with R PDF Author: Robin Lovelace
Publisher: CRC Press
ISBN: 1351396900
Category : Mathematics
Languages : en
Pages : 335

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Book Description
Geocomputation with R is for people who want to analyze, visualize and model geographic data with open source software. It is based on R, a statistical programming language that has powerful data processing, visualization, and geospatial capabilities. The book equips you with the knowledge and skills to tackle a wide range of issues manifested in geographic data, including those with scientific, societal, and environmental implications. This book will interest people from many backgrounds, especially Geographic Information Systems (GIS) users interested in applying their domain-specific knowledge in a powerful open source language for data science, and R users interested in extending their skills to handle spatial data. The book is divided into three parts: (I) Foundations, aimed at getting you up-to-speed with geographic data in R, (II) extensions, which covers advanced techniques, and (III) applications to real-world problems. The chapters cover progressively more advanced topics, with early chapters providing strong foundations on which the later chapters build. Part I describes the nature of spatial datasets in R and methods for manipulating them. It also covers geographic data import/export and transforming coordinate reference systems. Part II represents methods that build on these foundations. It covers advanced map making (including web mapping), "bridges" to GIS, sharing reproducible code, and how to do cross-validation in the presence of spatial autocorrelation. Part III applies the knowledge gained to tackle real-world problems, including representing and modeling transport systems, finding optimal locations for stores or services, and ecological modeling. Exercises at the end of each chapter give you the skills needed to tackle a range of geospatial problems. Solutions for each chapter and supplementary materials providing extended examples are available at https://geocompr.github.io/geocompkg/articles/. Dr. Robin Lovelace is a University Academic Fellow at the University of Leeds, where he has taught R for geographic research over many years, with a focus on transport systems. Dr. Jakub Nowosad is an Assistant Professor in the Department of Geoinformation at the Adam Mickiewicz University in Poznan, where his focus is on the analysis of large datasets to understand environmental processes. Dr. Jannes Muenchow is a Postdoctoral Researcher in the GIScience Department at the University of Jena, where he develops and teaches a range of geographic methods, with a focus on ecological modeling, statistical geocomputing, and predictive mapping. All three are active developers and work on a number of R packages, including stplanr, sabre, and RQGIS.

Moving Objects Databases

Moving Objects Databases PDF Author: Ralf Hartmut Güting
Publisher: Academic Press
ISBN: 0120887991
Category : Computers
Languages : en
Pages : 414

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Book Description
First uniform treatment of moving objects databases, the technology that supports GPS and RFID data analysis.

Key Concepts and Techniques in GIS

Key Concepts and Techniques in GIS PDF Author: Jochen Albrecht
Publisher: SAGE
ISBN: 1849206511
Category : Science
Languages : en
Pages : 121

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Book Description
Key Concepts and Techniques in GIS is a concise overview of the fundamental ideas that inform geographic information science. It provides detailed descriptions of the concepts and techniques that anyone using GIS software must fully understand to analyse spatial data. Short and clearly focussed chapters provide explanations of: spatial relationships and spatial data the creation of digital data, the use and access of existing data, the combination of data the use of modelling techniques and the essential functions of map algebra spatial statistics and spatial analysis geocomputation - including discussion of neural networks, cellular automata, and agent-based modelling Illustrated throughout with explanatory figures, the text also includes a glossary, cross referenced to discussion in the text. Written very much from a user′s perspective, Key Concepts and Techniques in GIS is highly readable refresher course for intermediate level students and practitioners of GIS in the social and the natural sciences.