Spatial News

Ph.D. Defense by Maria Vasardani

Mon, 09 Nov 2009 10:39:19

On Oct 28 2009, Maria Vasardani successfully defended her Ph.D. thesis with the title "Qualitative Spatial Reasoning with Holed Regions". Her advisor is Max Egenhofer. Congratulations, Maria!

A Survey of Geosensor Networks: Advances in Dynamic Environmental Monitoring

Mon, 09 Nov 2009 08:00:00

S. Nittel, A Survey of Geosensor Networks: Advances in Dynamic Environmental Monitoring, Sensors 2009, 9(7), 5664-5678; doi:10.3390/s90705664, published: 15 July 2009.

In the recent decade, several technology trends have influenced the field of geosciences in significant ways. The first trend is the more readily available technology of ubiquitous wireless communication networks and progress in the development of low-power, short-range radio-based communication networks, the miniaturization of computing and storage platforms as well as the development of novel microsensors and sensor materials. All three trends have changed the type of dynamic environmental phenomena that can be detected, monitored and reacted to. Another important aspect is the real-time data delivery of novel platforms today. In this paper, I will survey the field of geosensor networks, and mainly focus on the technology of small-scale geosensor networks, example applications and their feasibility and lessons learnt as well as the current research questions posed by using this technology today. Furthermore, my objective is to investigate how this technology can be embedded in the current landscape of intelligent sensor platforms in the geosciences and identify its place and purpose.

Three Funded Graduate Research Assistantships available in the Virtual Environment and Multimodal Interaction (VEMI) Lab

Tue, 20 Oct 2009 16:08:33

Three funded graduate research assistantships are currently available to work in the VEMI Lab, directed by Dr. Nicholas Giudice in the Department of Spatial Information Science and Engineering at the University of Maine, USA. Students will register for the degree of Masters or PhD.

All of the assistantships offer a generous support package, including a competitive stipend, complete tuition expenses, a book purchase program, a contribution to health insurance, and conference travel. All positions are immediately available but we are prepared to wait for as long as it takes for the right candidates. More information about the VEMI lab and these positions can be found at: www.vemilab.org or by emailing Dr. Giudice at: giudice@spatial.maine.edu.

Assistantship 1 relates to funding from the National Institutes of Health (NIH). The project investigates how spatial information from different input modalities (vision, haptics, 3D audio, and spatial language) is learned, represented in memory, and acted upon when supporting spatial behaviors with both blind and sighted people. Some of the research methodologies used include Psychophysical approaches, virtual environment technology and behavioral techniques for measuring spatial cognition abilities. This project affords an excellent opportunity for a student to get involved with basic questions about multisensory information processing as well as considering applications of the research to the design of non-visual interfaces. A strong background in Experimental Psychology / Cognitive Science is important and programming skills are desired for students interested in this assistantship.

We have two funded projects in the lab investigating the optimal information requirements for the design of dynamically-updated multimodal displays to support indoor navigation. Where GPS and large commercial GIS including streets and points of interest (POI) have revolutionized outdoor navigation, there is no equivalent positioning technology or databases to support indoor travel, e.g. where-am-I information , route guidance, or access to POI.

Assistantship 2 relates to a recent project funded by the National Science Foundation (NSF) investigating the best design for visual and multimodal interfaces to be used in a portable navigation system providing seamless outdoor/indoor (OI) assistance. As environmental information, data structures, technology aids, and navigation behavior differ greatly between outdoor and indoor spaces, this project represents an important step in bridging the OI space gap.

Assistantship 3 relates to a project funded by the NSF investigating the minimal information requirements for efficient spatial learning and navigation without vision, and usability research with 3D audio, haptic cues, and speech-based interfaces to support these behaviors. The ambitious goal is to develop an infrastructure independent, autonomous system for supporting indoor navigation for the blind.

Candidates for assistantships 2 and 3 will be working extensively with virtual environment technology, scripting, and the design and usability of multimodal interfaces. These positions require technical skills and are best suited for people with backgrounds in disciplines such as computer science, mechanical or electrical engineering, cognitive psychology / cognitive science, or behavioral geography.

The University of Maine is an Equal Opportunity/Affirmative Action Employer.

Our new 4+1 Graduate Program has started: Masters in Information Science (MSIS)

Mon, 31 Aug 2009 08:00:00

With the start of the Fall 2009 semester, our department now offers a new 4+1 graduate program in informatoin systems. The Master of Science in Information Systems program focuses on technical, managerial and policy issues associated with constructing and managing computer-based information systems for modern organizations. The objectives of this program are to meet the growing demand in society for graduates with high-level information system skills and provide a path for women and men from diverse fields to rapidly transition to information system career paths by providing them with foundation graduate level courses in information systems.

Similar to an MBA or Law degree, this program is explicitly designed to accommodate students from wide ranging undergraduate degree backgrounds.

For more information, check this website

Two funded PhD research assistantships announced

Mon, 27 Jul 2009 15:22:22

The Department of Spatial Information Science and Engineering and the National Center for Geographic Information and Analysis announce the availability of two funded PhD research assistantships. Students will be working with advisor Professor Mike Worboys and will register for the degree of PhD. The funding will cover a stipend, tuition, and a contribution to the health insurance premium. The first position relates to a recent project funded by the U.S. National Science Foundation entitled "Information integration and human interaction for indoor and outdoor spaces." The project abstract may be found at http://worboys.org/projects/Title%20and%20abstract.pdf. The second position relates to recent funding received on the use of spatial information systems and sensor technologies in emergency management. The main focus of both assistantships will be the creation of underlying models and fundamental theories. Candidates for both positions should hold a Master’s degree, or equivalent, in a subject that can be applied to spatial information systems and geographic information science (e.g., computer science, information systems, mathematics, or geography). The positions are available immediately, but we are prepared also to wait for the right candidates. Further information can be obtained by emailing Professor Worboys at: worboys@spatial.maine.edu. The University of Maine is an Equal Opportunity/Affirmative Action Employer.

SIE Department has Facebook page!

Mon, 13 Jul 2009 15:39:50

The SIE Department announces its presence on Facebook. Check us out here and feel free to become one of our fans!

Ph.D. Defense by Jixiang Jiang

Wed, 20 May 2009 08:00:00

Jixiang Jiang successfully defended his Ph.D. thesis with the title "SPECIFYING AND DETECTING TOPOLOGICAL CHANGES TO AREAL OBJECTS" today. His advisor is Dr. Mike Worboys; Drs. Kate Beard, Max Egenhofer, Silvia Nittel, and Bob Franzosa served on his Ph.D. thesis committee. Congrats, Jixiang!

Ph.D. thesis defense by Guang Jin

Wed, 22 Apr 2009 14:56:48

On April 8, 2009, Guang Jin successfully defended his Ph.D. thesis with the topic "Towards spatial queries over continuous phenomenon using sensor networks." His work included several approaches to compute field-based and object-based queries for detecting, estimating, and tracking continuous phenomena such as toxic chemical clouds and their boundaries using novel wireless sensor network technology. Guang has published ten papers throughout his graduate studies at UMaine and was supported by two NSF grants and a UMaine UGRA award. His advisor and committee chair was Dr. Silvia Nittel. His other committee members were Drs. Mike Worboys, Kate Beard, Clayton Wheeler, and Matt Duckham. Congratulations, Guang, on a job well done!

Onsrud receives Fulbright Specialists Award

Thu, 29 Jan 2009 16:01:06

Harlan Onsrud has been selected for a Fulbright Specialists project in Law in Australia at The University of Melbourne during February and March 2009, according to the United States Department of State and the J. William Fulbright Foreign Scholarship Board. Onsrud will develop and present five major lectures, known collectively as the 2009 Melbourne Fulbright Lectures on Cyberlaw and Spatial Technologies, focusing on key legal and policy issues with which the global spatial technology and mobile computing communities have been struggling. The lectures will be presented in a variety of academic forums and archived on the web to form a framework for global academic and practitioner discussions of the issues. The Fulbright Specialists Program, created in 2000 to complement the traditional Fulbright Scholar Program, provides short-term academic opportunities (two to six weeks) to prominent U.S. faculty and professionals to support curricular and faculty development and institutional planning at post secondary, academic institutions around the world. Congratulations to Harlan on receiving this award!

Nittel delivers keynote address at conference "Sensing in a Changing World", in Wageningen, NL

Thu, 20 Nov 2008 08:00:00

Dr. Nittel present a keynote address at the international conference "Sensing in a Changing World" in Wageningen, Netherlands. Her keynote is titled "Geosensor Networks: New Challenges in Environmental Monitoring using Wireless Sensor Networks".

NEW! - SIE newsletter now available

Wed, 22 Oct 2008 09:04:34

The SIE department has just released its Summer 2008 edition newsletter. A pdf version of the newsletter can be found here. We hope you find it informative and interesting and do feel free to give us your feedback. Cheers!

Department welcomes new faculty Reinhard Moratz and Nicholas Giudice

Mon, 22 Sep 2008 11:25:24

Dr. Reinhard Moratz and Dr. Nicholas Giudice, new faculty members in the Department of Spatial Information Science and Engineering, were welcomed by faculty, staff, and students at a recent social gathering hosted by Chair Michael Worboys. Associate Professor Moratz comes to the University of Maine from Hamburg, Germany, where he was a Senior Researcher at Plath GmbH. His research interests lie in the area of cognitive engineering for spatial applications. In his research about Human-Robot Interaction he develops a theory about how humans and robots can use simple, natural spatial expressions to achieve mutual understanding about a joint environment. Assistant Professor Giudice was a Postdoctoral Fellow in the Department of Psychology at the University of California, Santa Barbara, prior to joining the University of Maine. His research uses real and virtual environments to investigate multimodal spatial learning, cognitive mapping, and wayfinding behavior and the optimal information requirements for developing multimodal spatial displays to support these behaviors. His experiments compare human performance within and between modalities and output displays using 3-D sound, touch, vision, and spatial language. We are excited about Reinhard and Nick’s arrival in our department and extend a warm welcome and best wishes for a productive first year at UMaine! (pictured: Reinhard Moratz, standing; Nicholas Giudice, seated)

SIE alumnus Xavier Lopez inducted into Francis Crowe Society

Wed, 14 May 2008 09:01:00

SIE alumnus Xavier Lopez was inducted into the Francis Crowe Society as a Distinguished Engineer at the annual Francis Crowe Society ceremony held Saturday, May 10, 2008, at Hauck Auditorium on the UMaine campus. The purpose of the Francis Crowe Society is to recognize UMaine engineering graduates as they accomplish the formidable goal of completing their engineering degrees and to recognize others who have made considerable engineering contributions and honored the profession. Lopez graduated from UMaine in 1998 with a Ph.D. in Spatial Information Engineering. Since then, he has advanced to the position of Director of Oracle Corporation's Location Services group where he leads Oracle's efforts to incorporate spatial technologies across Oracle's database, application server, and eBusiness applications. He has been active in numerous academic and government research initiatives on geographic information, is the author of a book on government spatial information policy, and has authored over 50 scientific and industry publications in areas related to spatial information technology. Congratulations to Xavier on receiving this distinguished award! (pictured: SIE Professor Kate Beard, Xavier Lopez, SIE Department Chair Mike Worboys)

SIE students graduate - UMaine Commencement May 2008

Mon, 12 May 2008 10:59:00

University of Maine held its 206th Commencement on Saturday, May 10, 2008, at the Alfond Arena. Three SIE graduate students received their Master's degree in Spatial Information Science and Engineering. Three SIE undergraduate students received their Bachelor's degree in Information Systems Engineering. The SIE faculty hosted a celebratory luncheon in the department library where family and friends joined them in congratulating our graduates on their achievements, after which all proceeded to the Alfond Arena for the formal commencement ceremony. Congratulations graduates from all of us and we wish you the best for the future!

Master's in SIE graduates: Jeremy Onysko, Isolde Frank, Vijay Venkataraman

Bachelor's in ISE graduates: Ben Weber, Gabriel Irvine-McDermott, Steve Horn

Seniors model UMaine campus in 3D with Google Earth and visualize UMaine Event calendar: ISE Capstone Project

Thu, 08 May 2008 14:16:00

ISE seniors Ben Weber and Steve Horn presented their Capstone project on May 6, 2008, in the SIE library, Boardman Hall. For the past two semesters they have been working on completing a campus model for Google Earth under the guidance of SIE Professors Harlan Onsrud and Silvia Nittel. With contributions from students in UMaine's New Media Department, Ben and Steve have been able to model a good portion of the UM campus. Their current web page serves as a way to view campus events in this model along with resources for continued expansion and improved modeling of the campus. The project has advanced to the point where this new capability could be added to the Campus Calendar on UMaine's website. This addition to the UM website, if accepted, would link users to the Capstone project's event search page where the 3D model and campus event information would be available for download to Google Earth. Great job guys! (pictured: Steve Horn (l.), Ben Weber (r.))

Conceptual Neighborhoods of Topological Relations between Lines

Fri, 25 Apr 2008 12:29:17

R. Reis, M. Egenhofer, and J. Matos, Conceptual Neighborhoods of Topological Relations between Lines, in: A. Ruas and C.Gold (eds.), The 13th International Symposium on Spatial Data Handling (SDH 2008), Montpellier, France
Springer, June 2008.

Conceptual neighborhood graphs capture the similarity among qualitative relations. This paper derives the graphs for the thirty-three topological relations between two crisp, undirected lines and for the seventy-seven topological relations between two lines with uncertain boundaries. The analysis of the graphs shows that the normalized node degree increases, from the crisp to the broad-boundary lines, roughly at the same degree as it increases for crisp lines that are transformed from R1 into R2.

Perceptual Sketch Interpretation

Fri, 25 Apr 2008 12:27:09

Markus Wuersch and Max J. Egenhofer, Perceptual Sketch Interpretation, in: A. Ruas and C.Gold (eds.), The 13th International Symposium on Spatial Data Handling (SDH 2008), Montpellier, France Springer, June 2008.

An automated extraction of regions from sketches can be of great value for multi-modal user interfaces and for interpreting spatial data. This paper develops the Perceptual Sketch Interpretationalgorithm, which employs the theory of topological relations from spatial reasoning as well as continuity and good gestalt from gestalt theory in order to model people's perception. The Perceptual Sketch Interpretation algorithm extracts regions iteratively, removing one region at each a time, thus making the remaining sketch simpler and easier to interpret. The evaluation of the algorithm shows that the use of gestalt theory empowers the algorithm to correctly identify regions and saves processing time over other approaches.

Spatial Reasoning with a Hole

Fri, 25 Apr 2008 12:23:59

Max J. Egenhofer and Maria Vasardani, Spatial Reasoning with a Hole, in: S. Winter, M. Duckham, L. Kulik, and B. Kuipers (eds.), Conference on Spatial Information Theory (COSIT '07), Melbourne, Australia, Lecture Notes in Computer Science, Vol. 4736, Springer, pp. 303-320, September 2007.

Cavities in spatial phenomena require geometric representations of regions with holes. Existing models for reasoning over topological relations either exclude such specialized regions (9-intersection) or treat them indistinguishably from regions without holes (RCC-8). This paper highlights that inferences over a region with a hole need to be made separately from, and in addition to, the inferences over regions without holes. First the set of 23 topological relations between a region and a region with a hole is derived systematically. Then these relations' compositions over the region with the hole are calculated so that the inferences can be compared with the compositions of the topological relations over regions without holes. For 266 out of the 529 compositions the results over the region with the hole were more detailed than the corresponding results over regions without holes, with 95 of these refined cases providing even a unique result. In 27 cases, this refinement up to uniqueness compares with a completely undetermined inference for the relations over regions without holes.

Metric Details of Topological Line-Line Relations

Fri, 25 Apr 2008 12:20:06

Kostas Nedas, Max J. Egenhofer, and Dominik Wilmsen, Metric Details of Topological Line-Line Relations International Journal of Geographical Information Science 21 (1): 21-48, 2007.

Many real and artificial entities in geographic space, such as transportation networks and trajectories of movement, are typically modeled as lines in geographic information systems. In a similar fashion, people also perceive such objects as lines and communicate about them accordingly as evidence from research on sketching habits suggests. To facilitate new modalities like sketching that rely on the similarity among qualitative representations, oftentimes multi-resolution models are needed to allow comparisons between sketches and database scenes through successively increasing levels of detail. Within such a setting, topology alone is sufficient only for a coarse estimate of the spatial similarity between two scenes, whereas metric refinements may help extract finer details about the relative positioning and geometry between the objects. The 9-intersection is a topological model that distinguishes 33 relations between two lines based on the content invariant (empty-nonempty intersections) among boundaries, interiors, and exteriors of the lines. This paper extends the 9-intersection model by capturing metric details for line-line relations through splitting ratiosand closeness measures. Splitting ratios, which apply to the 9-intersection's non-empty values, are normalized values of lengths and areas of intersections. Closeness measures, which apply to the 9-intersection's empty values, are normalized distances between disjoint object parts. Both groups of measures are integrated into compact representations of topological relations, thereby addressing topological and metric properties of arbitrarily complex line-line relations.

SIE students participate in Graduate Research Exposition

Fri, 18 Apr 2008 10:55:00

The 10th Annual Graduate Research Exposition was held April 15-16, 2008, in the Buchanan Alumni House at the University of Maine. The Expo, which is organized by UMaine’s Graduate Student Government, is an opportunity for graduate students to showcase academic excellence and creative achievement. Graduate students from the Department of Spatial Information Science and Engineering with poster or oral presentations at the Expo were: David Almeida, Stacy Doore, Matthew Dube, Christopher Farah, Jixiang Jiang, Guang Jin, Qinghan Liang, Francois Neville, Arda Nural, Maria Vasardani, and Danqing Xiao. In addition, undergraduate senior Benjamin Weber participated in the Expo with a poster presentation. Three SIE students won prizes at the Expo. David Almeida won second prize and Francois Neville won third prize in the Engineering Posters category. And Maria Vasardani won second prize in the Engineering Talks category. Congratulations to David, Francois, and Maria and to all our SIE students for a job well done! (pictured, l. to r., Expo prize winners Francois Neville, David Almeida, Maria Vasardani)

Geo-Mobile Query-by-Sketch

Thu, 28 Dec 2006 13:18:00

David Caduff and Max J. Egenhofer, Geo-Mobile Query-by-Sketch, International Journal of Web Engineering and Technology, 3 (2): 157-175, 2007.

The advent of wireless technology, such as cellphones, PDAs, tablet PCs, and sub-notebooks, allows tranferring portions of traditional desktop-based GIS technology to mobile environments. This paper introduces Geo-Mobile Query-by-Sketch, a sketch-based spatial querying system for mobile GIS environment that combines techniques for spatial querying with mobile technologies. The system implements and adaptive client-server architecture, which copes with restrictions of mobile environments, such as fluctuating bandwidth and fre quent disconnections. The core concept analyzed is the mobile sketch, a multi-representation data structure of a sketched scene, which enables an adaption strategy that is tialored to the available transmission rates. We analyze the transmission cost of Geo-Mobile Query-by-Sketch and develop a protocol that optimizes the adaption level in order to guarantee quality of service.

The Head-Body-Tail Intersection for Spatial Relations Between Directed Line Segments

Thu, 28 Sep 2006 08:53:00

Yohei Kurata and Max J. Egenhofer, The Head-Body-Tail Intersection for Spatial Relations Between Directed Line Segments, in: M. Raubal, H. Miller, A. Frank, and M. Goodchild (eds.) GIScience 2006—4th International Conference on Geographic Information Science, Lecture Notes in Computer Science, Vol. 4197, pp. 269-286.

Abstract

Directed line segments are fundamental geometric elements used to model through their spatial relations such concepts as divergence, confluence, and interference. A new model is developed that captures spatial relations between pairs of directed line segments through the intersections of the segments' heads, bodies, and tails. This head-body-tail intersection identifies 68 classes of topological relations between two directed line segments highlighting two equal-sized subsets of corresponding relations that differ only by their empty and non-empty body-body intersections. The relations' conceptual neighborhood graph takes the shape of a torus inside a torus, one for each subset. Another 12 classes of topological relations are distinguished if the segments' exteriors are considered as well, lining up such that their conceptual neighborhood graph forms another torus that contains the other two tori. These conceptual neighborhoods as well as the relations' composition table enable spatial inferences and similarity assessments in a consistent and reasoned manner.

Changes in Topological Relations when Splitting and Merging Regions

Fri, 08 Sep 2006 00:00:00

M. Egenhofer and D. Wilmsen, Changes in Topological Relations with Splitting and Merging Regions, in: A. Riedl, W. Kainz, and G. Elmes (eds.), Progress in Spatial Data Handling -- 12th International Symposium on Spatial Data Handling, Springer, pp. 339-352.

Abstract

This paper addresses changes in topological relations as they occur when splitting a region into two. It derives systematically what qualitative inferences can be made about binary topological relations when one region is cut into two pieces. The new insights about the possible topological relations obtained after splitting regions form a foundation for high-level spatio-temporal reasoning without explicit geometric information about each object’s shapes, as well as for transactions in spatio-temporal databases that want to enforce consistency constraints.

GeoSpatial Semantics--First International Conference, GeoS 2005

Wed, 09 Nov 2005 00:00:00

A. Rodríguez, I. Cruz, M. Egenhofer, and S. Levashkin (editors), GeoSpatial Semantics--First International Conference, GeoS 2005, Lecture Notes in Computer Science, Vol. 3799, Spinger, New York, 2005.

This book contains the fully refereed papers of the First International Symposium on Geospatial Semantics, GeoS 2005, to be held in Mexico City, Mexico in November 2005.

Ontology-Driven Map Generalization

Wed, 12 Oct 2005 00:00:00

L. Kulik, M. Duckham, and M. Egenhofer, Ontology-Driven Map Generalization Journal of Visual Languages and Computing 16 (3): 245-267, 2005.

Abstract

Different users of geospatial information have different requirements of that information. Matching information to users' requirements demands an understanding of the ontological aspects of geospatial data. In this paper, we present an ontology-driven map generalization algorithm, called DMin, that can be tailored to particular users and users' tasks. The level of detail in a generated map is automatically adapted by DMin according to the semantics of the features represented. The DMin algorithm is based on a weighting function that has two components: (1) a geometric component that differs from previous approaches to map generalization in that no fixed threshold values are needed to parameterize the generalization process and (2) a semantic component that considers the relevance of map features to the user. The flexibility of DMin is demonstrated using the example of a transportation network.

Spherical Topological Relations

Thu, 01 Sep 2005 00:00:00

M. Egenhofer, Spherical Topological Relations, Journal on Data Semantics III: 25-49, 2005.

Abstract

Analysis of global geographic phenomena requires non-planar models. In the past, models for topological relations have focused either on a two-dimensional or a three-dimensional space. When applied to the surface of a sphere, however, neither of the two models suffices. For the two-dimensional planar case, the eight binary topological relations between spatial regions are well known from the 9-intersection model. This paper systematically develops the binary topological relations that can be realized on the surface of a sphere. Between two regions on the sphere there are three binary relations that cannot be realized in the plane. These relations complete the conceptual neighborhood graph of the eight planar topological relations in a regular fashion, providing evidence for a regularity of the underlying mathematical model. The analysis of the algebraic compositions of spherical topological relations indicates that spherical topological reasoning often provides fewer ambiguities than planar topological reasoning. Finally, a comparison with the relations that can be realized for one-dimensional, ordered cycles draws parallels to the spherical topological relations.

Advances in Spatial and Temporal Databases--9th International Symposium, SSTD 2005

Mon, 22 Aug 2005 00:00:00

C. Bauzer Medeiros, M. Egenhofer, and E. Bertino (editors), Advances in Spatial and Temporal Databases--Nineth International Symposium, SSTD 2005, Lecture Notes in Computer Science, Vol. 3633, Spinger, New York, 2005.

This book contains the fully refereed papers of the 9th International Symposium on Spatial and Temporal Databases, SSTD 2005, held in Angra dos Reis, Brazil in August 2005.

Qualitative change detection in sensor networks based on connectivity information

Wed, 31 Dec 1969 19:00:00