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Articles 31 - 60 of 116

Full-Text Articles in Databases and Information Systems

Discovery Of Topological Constraints On Spatial Object Classes Using A Refined Topological Model, Ivan Majic, Elham Naghizade, Stephan Winter, Martin Tomko Jun 2019

Discovery Of Topological Constraints On Spatial Object Classes Using A Refined Topological Model, Ivan Majic, Elham Naghizade, Stephan Winter, Martin Tomko

Journal of Spatial Information Science

In a typical data collection process, a surveyed spatial object is annotated upon creation, and is classified based on its attributes. This annotation can also be guided by textual definitions of objects. However, interpretations of such definitions may differ among people, and thus result in subjective and inconsistent classification of objects. This problem becomes even more pronounced if the cultural and linguistic differences are considered. As a solution, this paper investigates the role of topology as the defining characteristic of a class of spatial objects. We propose a data mining approach based on frequent itemset mining to learn patterns in …


Project Sidewalk: A Web-Based Crowdsourcing Tool For Collecting Sidewalk Accessibility Data At Scale, Manaswi Saha, Michael Saugstad, Hanuma Maddali, Aileen Zeng, Ryan Holland, Steven Bower, Aditya Dash, Sage Chen, Anthony Li, Kotaro Hara, Jon Froehlich May 2019

Project Sidewalk: A Web-Based Crowdsourcing Tool For Collecting Sidewalk Accessibility Data At Scale, Manaswi Saha, Michael Saugstad, Hanuma Maddali, Aileen Zeng, Ryan Holland, Steven Bower, Aditya Dash, Sage Chen, Anthony Li, Kotaro Hara, Jon Froehlich

Research Collection School Of Computing and Information Systems

We introduce Project Sidewalk, a new web-based tool that enables online crowdworkers to remotely label pedestrian-related accessibility problems by virtually walking through city streets in Google Street View. To train, engage, and sustain users, we apply basic game design principles such as interactive onboarding, mission-based tasks, and progress dashboards. In an 18-month deployment study, 797 online users contributed 205,385 labels and audited 2,941 miles of Washington DC streets. We compare behavioral and labeling quality differences between paid crowdworkers and volunteers, investigate the effects of label type, label severity, and majority vote on accuracy, and analyze common labeling errors. To complement …


Open Source Foundations For Spatial Decision Support Systems, Jochen Albrecht Dec 2018

Open Source Foundations For Spatial Decision Support Systems, Jochen Albrecht

Publications and Research

Spatial Decision Support Systems (SDSS) were a hot topic in the 1990s, when researchers tried to imbue GIS with additional decision support features. Successful practical developments such as HAZUS or CommunityViz have since been built, based on commercial desktop software and without much heed for theory other than what underlies their process models. Others, like UrbanSim, have been completely overhauled twice but without much external scrutiny. Both the practical and the theoretical foundations of decision support systems have developed considerably over the past 20 years. This article presents an overview of these developments and then looks at what corresponding tools …


Modeling Check-In Behavior With Geographical Neighborhood Influence Of Venues, Thanh Nam Doan, Ee Peng Lim Nov 2017

Modeling Check-In Behavior With Geographical Neighborhood Influence Of Venues, Thanh Nam Doan, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With many users adopting location-based social networks (LBSNs) to share their daily activities, LBSNs become a gold mine for researchers to study human check-in behavior. Modeling such behavior can benefit many useful applications such as urban planning and location-aware recommender systems. Unlike previous studies [4,6,12,17] that focus on the effect of distance on users checking in venues, we consider two venue-specific effects of geographical neighborhood influence, namely, spatial homophily and neighborhood competition. The former refers to the fact that venues share more common features with their spatial neighbors, while the latter captures the rivalry of a venue and its nearby …


Spatiotemporal Identification Of Anomalies In A Wildlife Preserve, Bharadwaj Kishan, Jason Guan Jie Ong, Yanrong Zhang, Tin Seong Kam Oct 2017

Spatiotemporal Identification Of Anomalies In A Wildlife Preserve, Bharadwaj Kishan, Jason Guan Jie Ong, Yanrong Zhang, Tin Seong Kam

Research Collection School Of Computing and Information Systems

The datasets released for the VAST Challenge 2017 comprise vehicle movement data captured with RFID sensors, chemical emission data from factories captured by gas sensors, and image attributes of the wildlife plant health obtained from satellites, all pertaining to a fictional wildlife preserve. Using visual analytics, a compelling hypothesis is established to link the spatiotemporal datasets to the phenomenon, where the count of a bird specimen is found to decline over a given year. Anomalies in vehicle traffic patterns are linked to proximal factory emissions, and further associated with satellite imagery that show proof of degradation in plant quality in …


Using Osgeo Solutions For Local Development Systems Implementation. The Experience For The Northern Region Of Costa Rica, López-Villegas Oscar, Víquez-Acuña Oscar, Víquez-Acuña Leonardo Sep 2017

Using Osgeo Solutions For Local Development Systems Implementation. The Experience For The Northern Region Of Costa Rica, López-Villegas Oscar, Víquez-Acuña Oscar, Víquez-Acuña Leonardo

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

Although some general definitions classify Spatial Data Infrastructures (SDI) as technological standards, institutional and even political agreements, which allow the discovery and use of geospatial information by users for different purposes [Kuhn 2005], computationally this platforms are valuable data repositories that should reach people efficiently and effectively for analysis and decision making on issues of collective interest. Costa Rica has several SDIs experiences at national level (SNIT - http://www.snitcr.go.cr), regional level (IDEHN - http://www.idehn.tec.ac.cr) or local/cantonal level (IDESCA - http://idesca.cr). Those infrastructures can facilitate access between geospatial information managers and their consumers through the implementation of particular software applications. The …


The Billion Object Platform (Bop): A System To Lower Barriers To Support Big, Streaming, Spatio-Temporal Data Sources, Devika Kakkar, Ben Lewis, David Smiley, Ariel Nunez Sep 2017

The Billion Object Platform (Bop): A System To Lower Barriers To Support Big, Streaming, Spatio-Temporal Data Sources, Devika Kakkar, Ben Lewis, David Smiley, Ariel Nunez

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

With funding from the Sloan Foundation and Harvard Dataverse, the Harvard Center for Geographic Analysis (CGA) has developed a big spatio-temporal data visualization platform called the Billion Object Platform or "BOP". The goal of the project is to lower barriers for scholars who wish to access large, streaming, spatio-temporal datasets. Since once archived, streaming data gets big fast, and since most GIS systems don't support interactive visualization of millions of objects, a new platform was needed. The BOP is loaded with the latest billion geo-tweets and is fed a real-time stream of about 1 million tweets per day. The CGA …


Optimizing Spatiotemporal Analysis Using Multidimensional Indexing With Geowave, Richard Fecher, Michael A. Whitby Sep 2017

Optimizing Spatiotemporal Analysis Using Multidimensional Indexing With Geowave, Richard Fecher, Michael A. Whitby

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

The open source software GeoWave bridges the gap between geographic information systems and distributed computing. This is done by preserving locality of multidimensional data when indexing it into a single-dimensional key-value store, using space filling curves. This means that like values in each dimension are stored physically close together in the datastore. We demonstrate the efficiencies and benefits of the GeoWave indexing algorithm to store and query billions of spatiotemporal data points. We show how this indexing strategy can be used to reduce query and processing times by multiple orders of magnitude using publicly available taxi trip data published by …


Introduction To Gis Using Open Source Software, 8th Ed, Frank Donnelly Jul 2017

Introduction To Gis Using Open Source Software, 8th Ed, Frank Donnelly

Open Educational Resources

This tutorial was created to accompany the GIS Practicum, a day-long workshop offered by the Newman Library at Baruch College CUNY that introduces participants to geographic information systems (GIS) using the open source software QGIS. The practicum introduces GIS as a concept for envisioning information and as a tool for conducting geographic analyses and creating maps. Participants learn how to navigate a GIS interface, how to prepare layers and conduct a basic geographic analysis, and how to create thematic maps. This tutorial was written using QGIS version 2.18 "Las Palmas", a cross-platform (Windows, Mac, Linux) desktop GIS software package.


Dynamic Nearest Neighbor Queries In Euclidean Space, Sarana Nutanong, Mohammed Eunus Ali, Egemen Tanin, Kyriakos Mouratidis May 2017

Dynamic Nearest Neighbor Queries In Euclidean Space, Sarana Nutanong, Mohammed Eunus Ali, Egemen Tanin, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Given a query point q and a set D of data points, a nearest neighbor (NN) query returns the data point p in D that minimizes the distance DIST(q,p), where the distance function DIST(,) is the L2norm. One important variant of this query type is kNN query, which returns k data points with the minimum distances. When taking the temporal dimension into account, the k NN query result may change over a period of time due to changes in locations of the query point and/or data points.


Mapping Community Space And Place In Mto Wa Mbu, Tanzania Through Surveys And Gis, Jessica Craigg Apr 2017

Mapping Community Space And Place In Mto Wa Mbu, Tanzania Through Surveys And Gis, Jessica Craigg

Georgia College Student Research Events

Cities throughout the African continent have been developing at an unprecedented pace, many of them due to the influence of the tourism industry. This is particularly true in Tanzania, a country famous for its national parks and their draw to tourists who help provide money for development. However, the only way to get the whole story on how to spend this money is through the experiences and needs of the people themselves. This study focuses on a small town in northeastern Tanzania, Mto wa Mbu, situated near Lake Manyara National Park, and its people’s perceptions of the park and community. …


Aiddata Gis International Fellowship: Ghana West-Africa, Jason N. Ready Dec 2016

Aiddata Gis International Fellowship: Ghana West-Africa, Jason N. Ready

International Development, Community and Environment (IDCE)

My internship, or fellowship as it was commonly referred to, was funded by a non-profit organization out of Williamsburg Virginia called AidData. This fellowship took place in in the country of Ghana, West-Africa beginning in May of 2016 and continued for 14 weeks with 40 hours each week. The objective of this internship was to provide in-depth training on the use of geographic Information Systems to Private and Public sectors within the country to allow for increased efficiency, and transparency through data visualization. In accordance with the requirement of Clark Universities GISDE master’s program this paper will delve into the …


Is Only One Gps Position Sufficient To Locate You To The Road Network Accurately?, Hao Wu, Weiwei Sun, Baihua Zheng Sep 2016

Is Only One Gps Position Sufficient To Locate You To The Road Network Accurately?, Hao Wu, Weiwei Sun, Baihua Zheng

Research Collection School Of Computing and Information Systems

Locating only one GPS position to a road segment accurately is crucial to many location-based services such as mobile taxihailing service, geo-tagging, POI check-in, etc. This problem is challenging because of errors including the GPS errors and the digital map errors (misalignment and the same representation of bidirectional roads) and a lack of context information. To the best of our knowledge, no existing work studies this problem directly and the work to reduce GPS signal errors by considering hardware aspect is the most relevant. Consequently, this work is the first attempt to solve the problem of locating one GPS position …


Introduction To Gis Using Open Source Software, 7th Ed, Frank Donnelly Jul 2016

Introduction To Gis Using Open Source Software, 7th Ed, Frank Donnelly

Open Educational Resources

This tutorial was created to accompany the GIS Practicum, a day-long workshop offered by the Newman Library at Baruch College CUNY that introduces participants to geographic information systems (GIS) using the open source software QGIS. The practicum introduces GIS as a concept for envisioning information and as a tool for conducting geographic analyses and creating maps. Participants learn how to navigate a GIS interface, how to prepare layers and conduct a basic geographic analysis, and how to create thematic maps. This tutorial was written using QGIS version 2.14 "Essen", a cross-platform (Windows, Mac, Linux) desktop GIS software package.


Exploring The Human Body Space: A Geographical Information System Based Anatomical Atlas, Antonio Barbeito, Marco Painho, Pedro Cabral, João Goyri O'Neill Jun 2016

Exploring The Human Body Space: A Geographical Information System Based Anatomical Atlas, Antonio Barbeito, Marco Painho, Pedro Cabral, João Goyri O'Neill

Journal of Spatial Information Science

Anatomical atlases allow mapping the anatomical structures of the human body. Early versions of these systems consisted of analogical representations with informative text and labeled images of the human body. With computer systems, digital versions emerged and the third and fourth dimensions were introduced. Consequently, these systems increased their efficiency, allowing more realistic visualizations with improved interactivity and functionality. The 4D atlases allow modeling changes over time on the structures represented. The anatomical atlases based on geographic information system (GIS) environments allow the creation of platforms with a high degree of interactivity and new tools to explore and analyze the …


A Context-Sensitive Conceptual Framework For Activity Modeling, Rahul Deb Das, Stephan Winter Jun 2016

A Context-Sensitive Conceptual Framework For Activity Modeling, Rahul Deb Das, Stephan Winter

Journal of Spatial Information Science

Human motion trajectories, however captured, provide a rich spatiotemporal data source for human activity recognition, and the rich literature in motion trajectory analysis provides the tools to bridge the gap between this data and its semantic interpretation. But activity is an ambiguous term across research communities. For example, in urban transport research activities are generally characterized around certain locations assuming the opportunities and resources are present in that location, and traveling happens between these locations for activity participation, i.e., travel is not an activity, rather a mean to overcome spatial constraints. In contrast, in human-computer interaction (HCI) research and in …


Μ-Shapes: Delineating Urban Neighborhoods Using Volunteered Geographic Information, Matt Aadland, Christopher Farah, Kevin Magee Jun 2016

Μ-Shapes: Delineating Urban Neighborhoods Using Volunteered Geographic Information, Matt Aadland, Christopher Farah, Kevin Magee

Journal of Spatial Information Science

Urban neighborhoods are a unique form of geography in that their boundaries rely on a social definition rather than a well-defined physical or administrative boundary. Currently, geographic gazetteers capture little more than then the centroid of a neighborhood, limiting potential applications of the data. In this paper, we present µ-shapes, an algorithm that employs fuzzy-set theory to model neighborhood boundaries suitable for populating gazetteers using volunteered geographic information (VGI). The algorithm is evaluated using a reference dataset and VGI from the Map Kibera Project. A confusion matrix comparison between the reference dataset and µ-shape's output demonstrated high sensitivity and accuracy. …


Creating The 2011 Area Classification For Output Areas (2011 Oac), Christopher G. Gale, Alexander D. Singleton, Andrew G. Bates, Paul A. Longley Jun 2016

Creating The 2011 Area Classification For Output Areas (2011 Oac), Christopher G. Gale, Alexander D. Singleton, Andrew G. Bates, Paul A. Longley

Journal of Spatial Information Science

This paper presents the methodology that has been used to create the 2011 Area Classification for Output Areas (2011 OAC). This extends a lineage of widely used public domain census-only geodemographic classifications in the UK. It provides an update to the successful 2001 OAC methodology, and summarizes the social and physical structure of neighborhoods using data from the 2011 UK Census. The results of a user engagement exercise that underpinned the creation of an updated methodology for the 2011 OAC are also presented. The 2011 OAC comprises 8 Supergroups, 26 Groups, and 76 Subgroups. An example of the results of …


Past Meets Future: Combining Gis, 3d Technologies, And Legacy Data To Reanalyze Ceramics At Copan, Honduras, Stephanie Sterling, Heather Richards-Rissetto, René Viel Apr 2016

Past Meets Future: Combining Gis, 3d Technologies, And Legacy Data To Reanalyze Ceramics At Copan, Honduras, Stephanie Sterling, Heather Richards-Rissetto, René Viel

UCARE Research Products

The archaeological site of Copán—a UNESCO World Heritage Site in Honduras—was a primary center for cultural and economic exchange in the Maya world from the fifth to ninth centuries. Our research investigates the sociopolitical climate of the city immediately preceding this collapse. This poster presents the results of a pilot study intended to evaluate the potential of using a combination of digital technologies and legacy data to reanalyze a subset of diagnostic ceramics from select sites outside of Copan’s urban core. Our methods involved:

(1) Applying photogrammetry to generate 3D models for approximately 30 potentially temporally-diagnostic ceramic types

(2) Digitizing, …


Spatial 2015, Werner Kuhn, Matt Duckham, Marcia Castro Dec 2015

Spatial 2015, Werner Kuhn, Matt Duckham, Marcia Castro

Journal of Spatial Information Science

This report summarizes the first in a new series of interdisciplinary unconferences, called SPATIAL. SPATIAL 2015 was focused on applying spatial information to human health, and was held at the Center for Spatial Studies at the University of California, Santa Barbara, 9-11 December 2015.


Spatial Refinement As Collection Order Relations, Zhong Zhao Dec 2015

Spatial Refinement As Collection Order Relations, Zhong Zhao

Journal of Spatial Information Science

An abstract examination of refinement (and conversely, coarsening) with respect to the involved spatial relations gives rise to formulated order relations between spatial coverings, which are defined as complete-coverage representations composed of regional granules. Coverings, which generalize partitions by allowing granules to overlap, enhance hierarchical geocomputations in several ways. Refinement between spatial coverings has underlying patterns with respect to inclusion—formalized as binary topological relations—between their granules. The patterns are captured by collection relations of inclusion, which are obtained by constraining relevant topological relations with cardinality properties such as uniqueness and totality. Conjoining relevant collection relations of equality and proper inclusion …


Routes Visualization: Automated Placement Of Multiple Route Symbols Along A Physical Network Infrastructure, Jules Teulade-Denantes, Adrien Maudet, Cécile Duchêne Dec 2015

Routes Visualization: Automated Placement Of Multiple Route Symbols Along A Physical Network Infrastructure, Jules Teulade-Denantes, Adrien Maudet, Cécile Duchêne

Journal of Spatial Information Science

This paper tackles the representation of routes carried by a physical network infrastructure on a map. In particular, the paper examines the case where each route is represented by a separate colored linear symbol offset from the physical network segments and from other routes---as on public transit maps with bus routes offset from roads. In this study, the objective is to automate the placement of such route symbols while maximizing their legibility, especially at junctions. The problem is modeled as a constraint optimization problem. Legibility criteria are identified and formalized as constraints to optimize, while focusing on the case of …


Invariant Spatial Information In Sketch Maps — A Study Of Survey Sketch Maps Of Urban Areas, Jia Wang, Angela Schwering Dec 2015

Invariant Spatial Information In Sketch Maps — A Study Of Survey Sketch Maps Of Urban Areas, Jia Wang, Angela Schwering

Journal of Spatial Information Science

It is commonly recognized that free-hand sketch maps are influenced by cognitive impacts and therefore sketch maps are incomplete, distorted, and schematized. This makes it difficult to achieve a one-to-one alignment between a sketch map and its corresponding geo-referenced metric map. Nevertheless, sketch maps are still useful to communicate spatial knowledge, indicating that sketch maps contain certain spatial information that is robust to cognitive impacts. In existing studies, sketch maps are used frequently to measure cognitive maps. However, little work has been done on invariant spatial information in sketch maps, which is the information of spatial configurations representing correctly the …


Development And Evaluation Of A Geographic Information Retrieval System Using Fine Grained Toponyms, Damien Palacio, Curdin Derungs, Ross S. Purves Dec 2015

Development And Evaluation Of A Geographic Information Retrieval System Using Fine Grained Toponyms, Damien Palacio, Curdin Derungs, Ross S. Purves

Journal of Spatial Information Science

Geographic information retrieval (GIR) is concerned with returning information in response to an information need, typically expressed in terms of a thematic and spatial component linked by a spatial relationship. However, evaluation initiatives have often failed to show significant differences between simple text baselines and more complex spatially enabled GIR approaches. We explore the effectiveness of three systems (a text baseline, spatial query expansion, and a full GIR system utilizing both text and spatial indexes) at retrieving documents from a corpus describing mountaineering expeditions, centred around fine grained toponyms. To allow evaluation, we use user generated content (UGC) in the …


Advances In Documentation, Digital Curation, Virtual Exhibition, And A Test Of 3d Geometric Morhpometrics: A Case Study Of The Vanderpool Vessels From The Ancestral Caddo Territory, Robert Z. Selden Jr., Timothy K. Perttula, Michael J. O'Brien Jan 2014

Advances In Documentation, Digital Curation, Virtual Exhibition, And A Test Of 3d Geometric Morhpometrics: A Case Study Of The Vanderpool Vessels From The Ancestral Caddo Territory, Robert Z. Selden Jr., Timothy K. Perttula, Michael J. O'Brien

CRHR: Archaeology

Three-dimensional (3D) digital scanning of archaeological materials is typically used as a tool for artifact documentation. With the permission of the Caddo Nation of Oklahoma, 3D documentation of Caddo funerary vessels from the Vanderpool site (41SM77) was conducted with the initial goal of ensuring that these data would be publicly available for future research long after the vessels were repatriated. A digital infrastructure was created to archive and disseminate the resultant 3D datasets, ensuring that they would be accessible by both researchers and the general public (CRHR 2014a). However, 3D imagery can be used for much more than documentation. To …


The Myths Of G-Tech For Business Decision Making, Tin Seong Kam Sep 2013

The Myths Of G-Tech For Business Decision Making, Tin Seong Kam

Research Collection School Of Computing and Information Systems

More than 80% of organisation data are location related - the locations where transactions are done, where retailers are found, and of customers who buy their products. Since the early 2005, there has been an increasing interest among the business community to use geospatial technology to enhance decision making process at both strategic and operational levels. Millions of dollars and man-hours have been invested into driving their geo-technology development and implementation. The use of geospatial technology in business, however, tends to confine to simple mapping. Many of these failures are the victims of misperception. Some of the perpetrators are practitioners. …


Riga: A Rich Internet Geospatial Analytics Application For Area-Based Data, Tin Seong Kam Sep 2013

Riga: A Rich Internet Geospatial Analytics Application For Area-Based Data, Tin Seong Kam

Research Collection School Of Computing and Information Systems

In this information age, more and more public statistical data such as population census, household living, local economy and business establishment are distributed over the internet within the framework of spatial data infrastructure. By and large, these data are organized geographically such as region, province as well as district. Usually, they are published in the form of digital maps over the internet as simple points, lines and polygons markers limited or no analytical function available to transform these data into useful information. To meet the analytical needs of casual public data users, we contribute RIGA, a rich internet geospatial analytics …


Introduction To Gis Using Open Source Software, 4th Ed, Frank Donnelly Aug 2013

Introduction To Gis Using Open Source Software, 4th Ed, Frank Donnelly

Open Educational Resources

This tutorial was created to accompany the GIS Practicum, a day-long workshop offered by the Newman Library at Baruch College CUNY that introduces participants to geographic information systems (GIS) using the open source software QGIS. The practicum introduces GIS as a concept for envisioning information and as a tool for conducting geographic analyses and creating maps. Participants learn how to navigate a GIS interface, how to prepare layers and conduct a basic geographic analysis, and how to create thematic maps. This tutorial was written using QGIS version 1.8 "Lisboa", a cross-platform (Windows, Mac, Linux) desktop GIS software package.


Automated Extraction Of Community Mobility Measures From Gps Stream Data Using Temporal Dbscan, Sungsoon Hwang, Timothy Hanke, Christian Evans May 2013

Automated Extraction Of Community Mobility Measures From Gps Stream Data Using Temporal Dbscan, Sungsoon Hwang, Timothy Hanke, Christian Evans

Sungsoon Hwang

Inferring community mobility of patients from GPS data has received much attention in health research. Developing robust mobility (or physical activity) monitoring systems relies on the automated algorithm that classifies GPS track points into events (such as stops where activities are conducted, and routes taken) accurately. This paper describes the method that automatically extracts community mobility measures from GPS track data. The method uses temporal DBSCAN in classifying track points, and temporal filtering in removing noises (any misclassified track points). The result shows that the proposed method classifies track points with 88% accuracy. The percent of misclassified track points decreased …


Putting Artists On The Map: A Five Part Study Of Greater Cleveland Artists' Location Decisions - Part 3: Attitudinal Analysis - Artist Housing And Space Survey, Mark Salling, Gregory Soltis, Charles Post, Sharon Bliss, Ellen Cyran Mar 2013

Putting Artists On The Map: A Five Part Study Of Greater Cleveland Artists' Location Decisions - Part 3: Attitudinal Analysis - Artist Housing And Space Survey, Mark Salling, Gregory Soltis, Charles Post, Sharon Bliss, Ellen Cyran

Ellen Cyran

A series of reports detailing the residential and work space location preferences of Cuyahoga county's artists.