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The University of Maine

2012

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Articles 1 - 30 of 89

Full-Text Articles in Physical Sciences and Mathematics

Tutorial Report: Understanding Spatial Thought Through Language Use, Thora Tenbrink, Tommaso D'Odorico, Christoph Hertzberg, Güzin Mazman, Chiara Meneghetti, Nina Reshöft, Jinlong Yang Dec 2012

Tutorial Report: Understanding Spatial Thought Through Language Use, Thora Tenbrink, Tommaso D'Odorico, Christoph Hertzberg, Güzin Mazman, Chiara Meneghetti, Nina Reshöft, Jinlong Yang

Journal of Spatial Information Science

The tutorial "Understanding spatial thought through language use" took place at the International Spatial Cognition Conference on August 31, 2012 at Kloster Seeon in Germany. This report outlines the main rationale for the tutorial along with central contributions by its participants, who considerably enhanced the success of the tutorial by sharing and discussing their own research experiences with respect to the analysis of language in spatial cognition contexts. The tutorial's website is http://knirb.net/TutorialSC2012.html.

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Geospatial Images In The Acquisition Of Spatial Knowledge For Wayfinding, Pyry Kettunen, Katja Irvankoski, Christina M. Krause, Tapani Sarjakoski, L. Tiina Sarjakoski Dec 2012

Geospatial Images In The Acquisition Of Spatial Knowledge For Wayfinding, Pyry Kettunen, Katja Irvankoski, Christina M. Krause, Tapani Sarjakoski, L. Tiina Sarjakoski

Journal of Spatial Information Science

Geospatial images such as maps and aerial photographs are important sources of spatial knowledge that people use for wayfinding. The rapid development of geodata acquisition and digital graphics has recently led to rather complete geographic coverage of both traditional and novel types of geospatial images. Divergent types of geospatial images vary in their support of human acquisition of spatial knowledge. However evaluative studies about the acquisition of spatial knowledge from the diversity of geospatial images have been rare. In this article we review a variety of literature about the acquisition of spatial knowledge while paying particular attention to the role …

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The Influence Of Landscape Variation On Landform Categorization, Maia Williams, Werner Kuhn, Marco Painho Dec 2012

The Influence Of Landscape Variation On Landform Categorization, Maia Williams, Werner Kuhn, Marco Painho

Journal of Spatial Information Science

This paper compares the landform vocabularies of residents from two regions in Portugal. Participants described both their own and the other less familiar landscapes in response to video footage of the regions. The results indicate that participants used more detailed vocabularies to describe the known landscape compared to the less familiar study site with detail triggered by individual place recognition. A relationship between landform lexica content and landscape type was observed in the relative placement of detail within each vocabulary. The observed drivers of categorization were the salient features of the landscape (elevation and land cover) and utilitarian motivations (land …

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Approaching The Notion Of Place By Contrast, Stephan Winter, Christian Freksa Dec 2012

Approaching The Notion Of Place By Contrast, Stephan Winter, Christian Freksa

Journal of Spatial Information Science

Place is an elusive notion in geographic information science. This paper presents an approach to capture the notion of place by contrast. This approach is developed from cognitive concepts and the language that is used to describe places. It is complementary to those of coordinate-based systems that dominate contemporary geographic information systems. Accordingly the approach is aimed at explaining structures in verbal place descriptions and at localizing objects without committing to geometrically specified positions in space. We will demonstrate how locations can be identified by place names that are not crisply defined in terms of geometric regions. Capturing the human …

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Spatial Reasoning With Augmented Points: Extending Cardinal Directions With Local Distances, Reinhard Moratz, Jan Oliver Wallgrün Dec 2012

Spatial Reasoning With Augmented Points: Extending Cardinal Directions With Local Distances, Reinhard Moratz, Jan Oliver Wallgrün

Journal of Spatial Information Science

We present an approach for supplying existing qualitative direction calculi with a distance component to support fully fledged positional reasoning. The general underlying idea of augmenting points with local reference properties has already been applied in the OPRAm calculus. In this existing calculus point objects are attached with a local reference direction to obtain oriented points and able to express relative direction using binary relations. We show how this approach can be extended to attach a granular distance concept to direction calculi such as the cardinal direction calculus or adjustable granularity calculi such as OPRAm or the Star calculus. We …

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Collaborative Research: Life Histories Of Species In The Genus Calanus In The North Atlantic And North Pacific Oceans And Responses To Climate Forcing, Jeffrey Runge, Andrew J. Pershing Dec 2012

Collaborative Research: Life Histories Of Species In The Genus Calanus In The North Atlantic And North Pacific Oceans And Responses To Climate Forcing, Jeffrey Runge, Andrew J. Pershing

University of Maine Office of Research Administration: Grant Reports

Species in the genus Calanus are predominant in the mesozooplankton of the North Atlantic and North Pacific Oceans. Their key role in marine food web interactions has been recognized in GLOBEC programs, both in the U.S. and internationally. Considerable knowledge of life history characteristics, including growth, reproduction, mortality, diapause behavior and demography has been acquired from both laboratory experiments and measurements at sea. This project reviews and synthesizes this knowledge and uses it to develop an Individual Based Life Cycle model for sibling species in two sympatric species pairs, C.marshallae and C. pacificus in the North Pacific Ocean and C. …

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Testing The Predictive Performance Of Distribution Models, Volker Bahn, Brian Mcgill Dec 2012

Testing The Predictive Performance Of Distribution Models, Volker Bahn, Brian Mcgill

Publications

Distribution models are used to predict the likelihood of occurrence or abundance of a species at locations where census data are not available. An integral part of modelling is the testing of model performance. We compared different schemes and measures for testing model performance using 79 species from the North American Breeding Bird Survey. The four testing schemes we compared featured increasing independence between test and training data: resubstitution, random data hold-out and two spatially segregated data hold-out designs. The different testing measures also addressed different levels of information content in the dependent variable: regression R2 for absolute abundance, squared …

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Minerva 2012, The Honors College Dec 2012

Minerva 2012, The Honors College

Minerva

This issue of Minerva includes a celebration of the life and impact of former Honors Dean, Charlie Slavin; a discussion of the Honors College's role in the University of Maine Blue Sky Strategic Plan; and profiles of student Kyle Franklin and alumni Heidi Crosby and Richard Becker.

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Sources To Seafood: Mercury Pollution In The Marine Environment, Celia Y. Chen, Charles T. Driscoll, Kathleen F. Lambert, Robert P. Mason, Laurie R. Rardin, Catherine V. Schmitt, N. S. Serrell, Elsie M. Sunderland Dec 2012

Sources To Seafood: Mercury Pollution In The Marine Environment, Celia Y. Chen, Charles T. Driscoll, Kathleen F. Lambert, Robert P. Mason, Laurie R. Rardin, Catherine V. Schmitt, N. S. Serrell, Elsie M. Sunderland

Maine Sea Grant Publications

In 2010, the Toxic Metals Superfund Research Program at Dartmouth College brought together a group of 50 scientists and policy stakeholders to form C-MERC, the Coastal and Marine Mercury Ecosystem Research Collaborative. The goal was to review current knowledge—and knowledge gaps—relating to a global environmental health problem, mercury contamination of the world’s marine fish. C-MERC participants attended two workshops over a two-year period, and in 2012 C-MERC authors published a series of peer-reviewed papers in the journals Environmental Health Perspectives and Environmental Research that elucidated key processes related to the inputs, cycling, and uptake of mercury in marine ecosystems, effects …

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Assessing Allelopathic Effects Of Alexandrium Fundyense On Thalassiosira Sp., Emily R. Lyczkowski Dec 2012

Assessing Allelopathic Effects Of Alexandrium Fundyense On Thalassiosira Sp., Emily R. Lyczkowski

Electronic Theses and Dissertations

Production of allelopathic chemicals by the toxic dinoflagellate Alexandrium fundyense is one suggested mechanism by which this relatively slow grower outcompetes other phytoplankton, particularly diatoms. Despite well documented allelopathic potential of Alexandrium spp., the potency is variable. To further characterize allelopathic effects of A. fundyense on diatoms in the Gulf of Maine, I studied growth and nutrient acquisition by the chain-forming diatom Thalassiosira sp. in the presence and absence of allelochemicals. Thalassiosira cells, upon exposure to filtrate of A. fundyense cultures exhibited “bleaching” and both growth and nutrient utilization ceased for up to 4 days compared to controls. Results from …

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Ecological Interactions Affecting Diatom Climate Reconstructions In Prairie Saline Lakes Of The Northern Great Plains (Usa), Courtney R. Wigdahl Dec 2012

Ecological Interactions Affecting Diatom Climate Reconstructions In Prairie Saline Lakes Of The Northern Great Plains (Usa), Courtney R. Wigdahl

Electronic Theses and Dissertations

Sedimentary diatom profiles from saline lakes are frequently used to reconstruct lakewater salinity as an indicator of drought. However, diatom-inferred salinity reconstructions (DI-salinity) from geographically-close sites in the Great Plains (USA) have yielded disparate results. Here, I explore how within-lake ecological processes, such as physical changes in lake habitat and zooplankton grazing pressure, may affect the accuracy of diatom-based salinity reconstructions. I examined how relationships differed among drought, lake-level change, and diatom community structure over the last century by developing three-dimensional models of planktic:benthic habitat (P:B) relationships with lake level change. I explored the potential for zooplankton grazing influence by …

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Polychaete Burrowing Behavior In Sand And Mud, Kevin Terrence Du Clos Dec 2012

Polychaete Burrowing Behavior In Sand And Mud, Kevin Terrence Du Clos

Electronic Theses and Dissertations

Marine sediments are continually reworked by resident organisms that control the ecology, chemistry, and physical structure of these vast systems. For example, the creation of a burrow brings oxygenated water into contact with anoxic sediment, facilitating aerobic respiration and supporting a distinct population of bacteria and meiofauna. Collectively, the effects of infauna on sediments and pore waters are known as bioturbation. Studying the behavior organisms that live beneath the sediment surface (infauna) is crucial to understanding the effects of bioturbation. Infauna can be difficult to study, however, because much their activity cannot be directly observed. The purpose of this thesis …

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Ecology Of Injury In Marine Sedimentary Habitats: Effects Of Repeated Injury On Infaunal Condition And Sediment Bioturbation, Sara M. Lindsay Nov 2012

Ecology Of Injury In Marine Sedimentary Habitats: Effects Of Repeated Injury On Infaunal Condition And Sediment Bioturbation, Sara M. Lindsay

University of Maine Office of Research Administration: Grant Reports

The majority of the ocean floor is sedimentary, and marine sediments play a key role in the flux of nutrients and organic matter in the ocean. Via their feeding and other activities, organisms living in marine sediments influence benthic-pelagic coupling by processing and redistributing organic matter supplied from the water column and influencing the supply of nutrients. These activities also influence recruitment and competitive interactions. Thus, factors that impact infaunal activity can secondarily impact sediment biogeochemistry and benthic communities. Non-lethal loss of body tissue is a common event for marine infauna such as polychaetes, and numerous studies have investigated the …

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Collaborative Research: North East Cyberinfrastructure Consortium, Michael Eckardt Nov 2012

Collaborative Research: North East Cyberinfrastructure Consortium, Michael Eckardt

University of Maine Office of Research Administration: Grant Reports

EPS-0918284, University of Vermont & State Agricultural College, J. L. Van Houten, linked to EPS-0918033 (University of New Hampshire), EPS-0918078 (University of Delaware), EPS-0918018 (University of Maine), EPS-0918061 (University of Rhode Island)
Collaborative Research: North East Cyberinfrastructure Consortium

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

The North East Cyberinfrastructure Consortium (NECC) unites Maine (ME), New Hampshire (NH), Vermont (VT), Rhode Island (RI), and Delaware (DE) to support cyber-enabled research that requires analyses of large datasets. The project is organized around sharing resources, expertise and facilities in order to make cyber-enabled collaborative …

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Mri: Acquisition Of An Sem-Eds-Ebsd-Cl Microanalytical System For Solid Earth And Climate Change Research, Christopher Gerbi, Daniel Belknap, Edward S. Grew, Scott Johnson Nov 2012

Mri: Acquisition Of An Sem-Eds-Ebsd-Cl Microanalytical System For Solid Earth And Climate Change Research, Christopher Gerbi, Daniel Belknap, Edward S. Grew, Scott Johnson

University of Maine Office of Research Administration: Grant Reports

Funding from the Major Research Instrumentation (MRI) Program grant will support acquisition of an Scanning Electron Microscope with secondary and backscattered electron detectors, electron backscatter diffraction capability, and live-color cathodluminescence capability for the Department of Earth Sciences at the University of Maine. The instrument will be used to support faculty and student research in geodynamics and crustal studies and studies of global climate change. The instrument will be the primary research tool of an early career researcher, but will be utilized by several faculty within the department. The scanning electron microscope facility is unique within the state of Maine and …

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Kinematic Vorticity Gauges And The Rheology Of Mylonitic Shear Zones, Scott E. Johnson Nov 2012

Kinematic Vorticity Gauges And The Rheology Of Mylonitic Shear Zones, Scott E. Johnson

University of Maine Office of Research Administration: Grant Reports

Many hazards encountered by humans, including earthquakes, volcanic eruptions and tsunamis, result from plate tectonics. How tectonic plates move and interact with one another, and how deformation that occurs at their interacting boundaries is localized into structures like the San Andreas fault in California, are first-order questions in the Earth Sciences. At active tectonic plate boundaries, GPS data have allowed a much clearer understanding of plate interactions, localization of deformation, and relations to seismic and volcanic hazards. However, such data provide little information about plate interaction and deformation at great depth. The most direct way to study these deeper processes …

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Cybergis - Toward Synergistic Advancement Of Cyberinfrastructure And Giscience: A Workshop Summary, Shaowen Wang, Nancy R. Wilkins-Diehr, Timothy L. Nyerges Oct 2012

Cybergis - Toward Synergistic Advancement Of Cyberinfrastructure And Giscience: A Workshop Summary, Shaowen Wang, Nancy R. Wilkins-Diehr, Timothy L. Nyerges

Journal of Spatial Information Science

This community activity report describes the outcomes of a CyberGIS workshop held in conjunction with the UCGIS 2010 annual winter meeting and sponsored by the National Science Foundation (NSF) Office of Cyberinfrastructure. Over the one and one-half day workshop a multidisciplinary group of experts from the international communities of cyberinfrastructure GIScience spatial analysis and modeling and several other related scientific domains were brought together for a participatory meeting composed of both small- and large-group settings and to discuss the CyberGIS road map.

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Spatial Models For Context-Aware Indoor Navigation Systems: A Survey, Imad Afyouni, Cyril Ray, Christophe Claramunt Oct 2012

Spatial Models For Context-Aware Indoor Navigation Systems: A Survey, Imad Afyouni, Cyril Ray, Christophe Claramunt

Journal of Spatial Information Science

This paper surveys indoor spatial models developed for research fields ranging from mobile robot mapping to indoor location-based services (LBS) and most recently to context-aware navigation services applied to indoor environments. Over the past few years several studies have evaluated the potential of spatial models for robot navigation and ubiquitous computing. In this paper we take a slightly different perspective considering not only the underlying properties of those spatial models but also to which degree the notion of context can be taken into account when delivering services in indoor environments. Some preliminary recommendations for the development of indoor spatial models …

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Computationally Determining The Salience Of Decision Points For Real-Time Wayfinding Support, Makoto Takemiya, Toru Ishikawa Oct 2012

Computationally Determining The Salience Of Decision Points For Real-Time Wayfinding Support, Makoto Takemiya, Toru Ishikawa

Journal of Spatial Information Science

This study introduces the concept of computational salience to explain the discriminatory efficacy of decision points which in turn may have applications to providing real-time assistance to users of navigational aids. This research compared algorithms for calculating the computational salience of decision points and validated the results via three methods: high-salience decision points were used to classify wayfinders; salience scores were used to weight a conditional probabilistic scoring function for real-time wayfinder performance classification; and salience scores were correlated with wayfinding-performance metrics. As an exploratory step to linking computational and cognitive salience a photograph-recognition experiment was conducted. Results reveal a …

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Affordance-Based Individuation Of Junctions In Open Street Map, Simon Scheider, Jörg Possin Oct 2012

Affordance-Based Individuation Of Junctions In Open Street Map, Simon Scheider, Jörg Possin

Journal of Spatial Information Science

We propose an algorithm that can be used to identify automatically the subset of street segments of a road network map that corresponds to a junction. The main idea is to use turn-compliant locomotion affordances i.e. restricted patterns of supported movement in order to specify junctions independently of their data representation and in order to motivate tractable individuation and classification strategies. We argue that common approaches based solely on geometry or topology of the street segment graph are useful but insufficient proxies. They miss certain turn restrictions essential to junctions. From a computational viewpoint the main challenge of affordance-based individuation …

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Semantic Trajectory Compression: Representing Urban Movement In A Nutshell, Kai-Florian Richter, Falko Schmid, Patrick Laube Oct 2012

Semantic Trajectory Compression: Representing Urban Movement In A Nutshell, Kai-Florian Richter, Falko Schmid, Patrick Laube

Journal of Spatial Information Science

There is an increasing number of rapidly growing repositories capturing the movement of people in space-time. Movement trajectory compression becomes an obvious necessity for coping with such growing data volumes. This paper introduces the concept of semantic trajectory compression (STC). STC allows for substantially compressing trajectory data with acceptable information loss. It exploits that human urban mobility typically occurs in transportation networks that define a geographic context for the movement. In STC a semantic representation of the trajectory that consists of reference points localized in a transportation network replaces raw highly redundant position information (e.g. from GPS receivers). An experimental …

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Editorial, Matt Duckham Oct 2012

Editorial, Matt Duckham

Journal of Spatial Information Science

No abstract provided.

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A Wayfinding Aid To Increase Navigator Independence, Wilfred Waters, Stephan Winter Oct 2012

A Wayfinding Aid To Increase Navigator Independence, Wilfred Waters, Stephan Winter

Journal of Spatial Information Science

Wayfinding aids are of great benefit because users do not have to rely on their learned geographic knowledge or orientation skills alone for successful navigation. Additionally cognitive resources usually captured by this activity can be spent elsewhere. A challenge however remains for wayfinding aid developers. Due to the automation of wayfinding aids navigator independence may be decreasing via the use of these aids. In order to address this wayfinding aids might be improved additionally to perform a training role. Since the most versatile wayfinders appear to deploy a dual strategy for geographic orientation it is proposed that wayfinding aids be …

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Geocam: A Geovisual Analytics Workspace To Contextualize And Interpret Statements About Movement, Anuj Jaiswal, Scott Pezanowski, Prasenjit Mitra, Xiao Zhang, Sen Xu, Ian Turton, Alexander Klippel, Alan M. Maceachren Oct 2012

Geocam: A Geovisual Analytics Workspace To Contextualize And Interpret Statements About Movement, Anuj Jaiswal, Scott Pezanowski, Prasenjit Mitra, Xiao Zhang, Sen Xu, Ian Turton, Alexander Klippel, Alan M. Maceachren

Journal of Spatial Information Science

This article focuses on integrating computational and visual methods in a system that supports analysts to identify extract map and relate linguistic accounts of movement. We address two objectives: (1) build the conceptual theoretical and empirical framework needed to represent and interpret human-generated directions; and (2) design and implement a geovisual analytics workspace for direction document analysis. We have built a set of geo-enabled computational methods to identify documents containing movement statements and a visual analytics environment that uses natural language processing methods iteratively with geographic database support to extract interpret and map geographic movement references in context. Additionally analysts …

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Segmenting Trajectories: A Framework And Algorithms Using Spatiotemporal Criteria, Maike Buchin, Anne Driemel, Marc Van Kreveld, Vera Sacristan Oct 2012

Segmenting Trajectories: A Framework And Algorithms Using Spatiotemporal Criteria, Maike Buchin, Anne Driemel, Marc Van Kreveld, Vera Sacristan

Journal of Spatial Information Science

In this paper we address the problem of segmenting a trajectory based on spatiotemporal criteria. We require that each segment is homogeneous in the sense that a set of spatiotemporal criteria are fulfilled. We define different such criteria including location heading speed velocity curvature sinuosity curviness and shape. We present an algorithmic framework that allows us to segment any trajectory into a minimum number of segments under any of these criteria or any combination of these criteria. In this framework a segmentation can generally be computed in O(n log n) time where n is the number of edges of the …

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Connect The Dot: Computing Feed-Links For Network Extension, Boris Aronov, Kevin Buchin, Maike Buchin, Bart Jansen, Tom De Jong, Marc Van Kreveld, Maarten Loffler, Jun Luo, Rodrigo I. Silveira, Bettina Speckmann Oct 2012

Connect The Dot: Computing Feed-Links For Network Extension, Boris Aronov, Kevin Buchin, Maike Buchin, Bart Jansen, Tom De Jong, Marc Van Kreveld, Maarten Loffler, Jun Luo, Rodrigo I. Silveira, Bettina Speckmann

Journal of Spatial Information Science

Road network analysis can require distance from points that are not on the network themselves. We study the algorithmic problem of connecting a point inside a face (region) of the road network to its boundary while minimizing the detour factor of that point to any point on the boundary of the face. We show that the optimal single connection (feed-link) can be computed in O(lambda_7(n) log n) time where n is the number of vertices that bounds the face and lambda_7(n) is the slightly superlinear maximum length of a Davenport-Schinzel sequence of order 7 on n symbols. We also present …

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Editorial, Jörg-Rüdiger Sack Oct 2012

Editorial, Jörg-Rüdiger Sack

Journal of Spatial Information Science

No abstract provided.

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Report On The First Workshop On Movement Pattern Analysis Mpa10, Patrick Olivier Laube, Björn Gottfried, Alexander Klippel, Roland Billen, Nico Van De Weghe Oct 2012

Report On The First Workshop On Movement Pattern Analysis Mpa10, Patrick Olivier Laube, Björn Gottfried, Alexander Klippel, Roland Billen, Nico Van De Weghe

Journal of Spatial Information Science

This paper reports on the 1st Workshop on Movement Pattern Analysis, held as a pre-GIScience 2010 workshop in September 2010 in Zurich, Switzerland. The report outlines the scientific motivation for the event, summarizes its main contributions and outcomes, discusses the implications of the gathering, and indicates directions for the road ahead.

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Towards A Computational Transportation Science, Stephan Winter, Monika Sester, Ouri Wolfson, Glenn Geers Oct 2012

Towards A Computational Transportation Science, Stephan Winter, Monika Sester, Ouri Wolfson, Glenn Geers

Journal of Spatial Information Science

This report of a community activity a Dagstuhl Seminar earlier in 2010 postulates the need for a computational transportation science as the science behind intelligent transportation systems. In addition to the argument for establishing a discipline we present a first research agenda for computational transportation science.

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Uncertainty-Aware Video Visual Analytics Of Tracked Moving Objects, Markus Höferlin, Benjamin Höferlin, Daniel Weiskopf, Gunther Heidemann Oct 2012

Uncertainty-Aware Video Visual Analytics Of Tracked Moving Objects, Markus Höferlin, Benjamin Höferlin, Daniel Weiskopf, Gunther Heidemann

Journal of Spatial Information Science

Vast amounts of video data render manual video analysis useless while recent automatic video analytics techniques suffer from insufficient performance. To alleviate these issues we present a scalable and reliable approach exploiting the visual analytics methodology. This involves the user in the iterative process of exploration hypotheses generation and their verification. Scalability is achieved by interactive filter definitions on trajectory features extracted by the automatic computer vision stage. We establish the interface between user and machine adopting the VideoPerpetuoGram (VPG) for visualization and enable users to provide filter-based relevance feedback. Additionally users are supported in deriving hypotheses by context-sensitive statistical …

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