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Spatial and More Seminar Series

October 18th, 2016

Please place the following presentations on your calendar for the remainder of the fall semester.

Spatial and More Seminar Series

Sponsored by NCGIA

October 19: 12:00 336 Boardman Hall

Chris Bennet, PhD student in Spatial Information Science and Engineering

Evaluating and Alleviating Cognitive Map Decay for Older Adult Navigators through the use of Virtual Reality Simulation

Abstract. The aging process is associated with changes to various tasks of daily life for older adults, e.g. driving and walking. This is particularly challenging in rural areas where public transportation is often non-existent. The current research explored how age affects navigation ability through use of virtual reality simulations. Particularly, these research studies focus on the decay of cognitive maps (mental representations of space) for older adult navigators over time. In each study, participants were required to learn and sketch cognitive maps of various virtual environments at several time intervals (in-lab and after 1-day, 1-week, and 2-weeks). Results consistently show that older adult performance was lower than the younger adult group and also revealed declines of cognitive map accuracy over the time delay periods. Results also demonstrate the efficacy of immersive virtual reality as an effective research tool. Based on these findings, compensatory augmentations (navigational aids) are currently being developed and tested. This research provides evidence for cognitive map decay, implications of potential solutions, and enriches the understanding of navigation and age-related concerns.


November 2: 12:00 336 Boardman Hall

Stacy Doore, PhD student in Spatial Information Science and Engineering

Spatial Preposition Use in Indoor Scene Descriptions

Abstract. In order to provide accurate automated scene description and navigation directions for indoor space, human beings need intelligent systems to provide an effective cognitive model. Information provided by the structure and use of spatial prepositions is critical to the development of accurate and effective cognitive models. The use and choice of spatial prepositions in natural language is extremely varied, presenting difficulties for natural language systems attempting to provide descriptions of indoor scenes and wayfinding directions. The goal of the present study is to better understand how English language speakers use spatial prepositions to communicate spatial relationships within virtual environment (VE) indoor scenes. This talk will present findings from a series of experiments that investigate spatial preposition use and the influence of scale, topology, orientation and distance within indoor scene.


November 19  12:00 336 Boardman Hall

Cyndy Loftin, Associate Professor and Unit Leader, Maine Cooperative Fish and Wildlife Research Unit

Priority Amphibian and Reptile Conservation Areas (PARCAs): Applying quantitative approaches and expert opinion to identify conservation areas and evaluate vulnerability

Abstract. The PARCA project is a national initiative to map important amphibian and reptile habitats based on knowledge of species’ distributions and habitat associations. We applied PARCA guidelines with species distribution modeling via the Maximum Entropy algorithm to model habitat suitability for northeastern herpetofauna of conservation significance. Our modeled PARCAs combined habitat suitability models based on known species occurrences and important abiotic variables with species richness and landscape integrity estimates. We evaluated our models by comparing predicted with observed data, identified gaps in species occurrence and richness datasets affecting model outcomes, consulted with state herpetologists to understand how our spatial application of the PARCA criteria captured quality habitat for modeled species, and evaluated representation of PARCAs in the network of current conservation lands. Our efforts can inform conservation of priority landscapes for northeastern herpetofauna, including assessment of the long-term vulnerability and climate resiliency of these habitats.


November 30 12:00 336 Boardman Hall

Anne Knowles, Professor of History

Seeking Space and Place in the Holocaust

Abstract. The Holocaust has become a new focus of spatial historical research, both theoretical and empirical. The wealth of bureaucratic records and plans makes it relatively easy to map Nazi actions, the establishment and demise of camps and ghettos, and Nazi spatial visions for the Reich. Although interviews with Holocaust survivors contain many kinds of spatial information, much of it is poorly suited to GIS and other modes of conventional geographical analysis and representation. This presentation will explain the issues of bridging the gap between perpetrator and victim histories in the Holocaust, and describe the modes of textual analysis that may enable spatial interpretation of victims’ experiences.

Two PhDs Conferred by SCIS

May 11th, 2016

The School of Information and Computing Science is proud to announce that on Saturday, May 14th, the school will be conferring the title of PhD to two students. Both Hengshan Li and Matthew Dube have worked very diligently on their dissertations, and have been hired to exciting new jobs after graduation. The following is a description of their dissertation research and future plans.

Evaluation of multi-level cognitive maps for supporting between-floor spatial behavior in complex indoor environments

By Hengshan Li

Advisor: Dr, Nicholas A. Giudice, Associate Professor in Spatial Informatics, School of Computing and Information Science


People often become disoriented when navigating in complex, multi-level buildings. To efficiently find destinations located on different floors, navigators must refer to a globally coherent mental representation of the multi-level environment, which is termed a multi-level cognitive map. However, there is a surprising dearth of research into underlying theories of why integrating multi-level spatial knowledge into a multi-level cognitive map is so challenging and error-prone for humans. This overarching problem is the core motivation of this dissertation.

This dissertation addresses this vexing problem in a two-pronged approach combining study of both basic and applied research questions. Of theoretical interest, we investigate questions about how multi-level built environments are learned and structured in memory. The concept of multi-level cognitive maps and a framework of multi-level cognitive map development are provided. We then conducted a set of empirical experiments to evaluate the effects of several environmental factors on users’ development of multi-level cognitive maps. The findings of these studies provide important design guidelines that can be used by architects and help to better understand the research question of why people get lost in buildings. Related to application, we investigate questions about how to design user-friendly visualization interfaces that augment users’ capability to form multi-level cognitive maps. An important finding of this dissertation is that increasing visual access with an X-ray-like visualization interface is effective for overcoming the disadvantage of limited visual access in built environments and assists the development of multi-level cognitive maps. These findings provide important human-computer interaction (HCI) guidelines for visualization techniques to be used in future indoor navigation systems.

In sum, this dissertation adopts an interdisciplinary approach, combining theories from the fields of spatial cognition, information visualization, and HCI, addressing a long-standing and ubiquitous problem faced by anyone who navigates indoors: why do people get lost inside multi-level buildings. Results provide both theoretical and applied levels of knowledge generation and explanation, as well as contribute to the growing field of real-time indoor navigation systems.

After UMaine, Hengshan will join in Singapore-ETH Centre, Future Cities Laboratory. He will take part in a research project aiming to understand the perceptual and cognitive processes underlying pedestrian movement and wayfinding behavior, provide design interventions informed by empirical research and simulations, and develop simulations for visualizing and validating empirical results and proposed design solutions.


Algebraic Refinements of Direction Relations Through Topological Augmentation

By Matthew P. Dube

Advisor: Dr. Max J. Egenhofer, Professor and Directior, School of Computing and Information Science


The world of spatial information has been painstakingly studied over the past forty years and, for the attainment of compact and meaningful systems, split into a triumvirate of domains for qualitative spatial reasoning: topology, direction, and distance. As advances in computation have led to quicker computation, the need for smaller, cognitively held systems is reduced, opening the door for larger reasoning systems that violate Occam’s Razor.

This dissertation attempts to bring separated concepts of qualitative spatial reasoning together by using the concept of spatial partitions. Partitions are mutually exclusive sets that exhaustively cover an embedding space. Qualitative direction relations over regions are currently constructed from these partitions and are based on intersection models. In this dissertation, topological relations are used to refine the qualitative direction relations over regions currently in the literature and graph theoretic definitions and theorems are presented to apply these concepts to arbitrary spatial partitions of co-dimension 0 to their embedding space.

This combination is called topological augmentation. Rather than computing binary set intersections between a figure object and ground tiling structure, topological augmentation expands this approach by computing a topological set intersection resulting in a topological relation from the region-region relations, providing additional insights into the qualitative extent of an object. Such an approach allows for a reasoning system with over 3,000 relations, relations that can be applied to particular semantic definitions based upon their context.

With the creation of such a verbose system, the interplay between direction and topology is explored and refined in a novel way by integrating the two separate forms of information before the reasoning task is attempted. While previous research has attempted combinations of direction and topology, the more verbose system presented in this work provides a transfer between direction and topology that is reduced in cardinality, a large benefit in the world of volunteered geographic information. A similar effect is also shown in the computation of converse relations and compositions using the verbose system as a guideline, moving the standard of composition in areal direction relations from the domain of weak composition to that of strong composition.

The key benefit of this approach is in the aspect of computing the composition of direction relation matrices. While a decade of research has attempted to solidify this result, numerous attempts have tried and failed to produce a systematic and verifiable composition for a given pair of objects, known as the strong composition, instead being successful only in the computation of the weak composition, that which can occur for at least one element of the set represented by the combination of objects. Through the use of topological augmentation, the strong composition of direction relation matrices is attained. Patterns in the composition are identified based on the coincidence of tile boundaries with object boundaries, a key insight that can produce crisper compositions at a minimal cost in complexity. This particular cost of complexity (from binary to topological) also serves the purpose of integrating direction relations into commercial GISs based on topological means through reverse engineering, given that the interface for computing topological relations and querying over them already exists.

Finally, composition is analyzed relative to the properties of a relation algebra, a fundamental question in the realm of artificial intelligence. It is demonstrated that the composition and converse properties of the direction relation matrix (with or without topological augmentation) do not produce a proper involution systematically, and thus the spatial representation cannot form a relation algebra. Many relation pairs as a composition are involutable, but not all. These properties are based on symmetry within the space relative to minimum bounding rectangle relations. The nature of involution in this case motivates the choices of particular forms of a relation between pairs of objects, one of the first scenarios in spatial literature where the choice of the order of the relation matters for a purpose other than a cosmetic one.

Future work is proposed to integrate direction relations into commercial GISs and to further explore the remaining properties of relation algebra relative to partition-based direction relations. Since the current gold standard is not involutable, a research agenda is proposed to determine whether or not a worthwhile direction-based information system can be developed that is endowed with universal involution, thus mitigating the effects of choices of relational order.

After UMaine, Matthew will join the faculty at the University of Maine at Augusta to become an Assistant Professor of Computer and Information Systems.

Congratulations to Hengshan and Matthew, we look forward to your impacts on your fields!



SCIS Students Present at Research Symposium

May 8th, 2016

On April 27th, three students from the School of Computing and Information Science presented their cutting edge research at the 2016 Graduate and Undergraduate Research Symposium at the Cross Insurance Arena in Bangor, Maine. These students include HariPrasath Palani, Stacy Doore, and Christopher Bennett. The abstracts from their respective research projects may be found below.


HariPrasath Palani, “Multimodal Access to Graphical Information for Blind and Visually-Impaired people using Touchscreen-based devices.”

The proliferation of touchscreen devices has amplified the use of graphical information, most of which is visual in nature. The lack of inexpensive, nonvisual graphical access solutions is concerning for over 12 million blind and visually-impaired (BVI) people in the U.S. (and 285 million worldwide). My research addresses this issue through evaluation, design, and development of a touchscreen-based multimodal interface called a Vibro-Audio Interface (VAI) – that allows BVI users to apprehend and learn graphical information using commercially-available technology. The VAI’s efficacy has been previously demonstrated for conveying graphical information (e.g., graphs and maps) and my work aims to better characterize the underlying perceptual / cognitive factors involved in learning with this new class of information access technology. Two preliminary psychophysically-inspired usability studies addressed the perceptual parameters for detecting and tracing graphical stimuli rendered with the VAI, with results demonstrating that a minimum of 1mm width is necessary for detecting lines using haptic feedback and a width of at least 3mm is needed for effective line tracing. My dissertation research addressing other perceptual parameters needed for nonvisual graphical access will lead to new conceptual models of multimodal information access and development of human-centered design specifications for future multimodal touchscreen-based accessibility solutions.

Stacy Doore, “A Room with a View: Designing Natural Language Interface Structures for Indoor Scene Description.” 

We are increasingly reliant upon intelligent agents with natural language (NL) communication abilities to interact with the world around us. While mature technology exists to accurately describe and navigate outdoor settings, the creation of automated NL systems that can effectively communicate spatial scenes within indoor environments presents significant challenges. Descriptions of objects and structures within built environments differ from those of outdoor space due to the lack of metric data and the absence of standard indoor landmarks. This presentation will describe a series of experiments related to spatial preposition use patterns, preferences, and rules within different vista scale indoor environments along with early results. This research contributes to the development of technologies to support mobile device cameras to be used as visual sensors to obtain images of indoor spaces and convert the imagery to verbal descriptions of the indoor space. The formal rules and spatial reasoning structures resulting from this study will allow for the creation of a spatial preposition thesaurus for intelligent systems used within indoor environments. Applications of this research includes indoor navigation support for emergency responders, assistive technologies for elderly and blind and low vision users, and automated customer assistance for location-based retail services.

Christopher Bennett, “Do Cognitive Maps Decay with Age?”

A critical component of effective navigation is the ability to form and maintain an accurate cognitive map, which includes paths, landmarks, and the allocentric global relations between them. Proper cognitive map maintenance can become difficult for older adults as many of the constituent memory structures experience degradation with age. While driving, we rely on our cognitive maps to update our location, the relations between surrounding landmarks, and to plan routes. The present study had younger and older adult participants form cognitive maps using a virtual reality driving simulator and then tested these representations one day and one week later to measure cognitive map decay. Data collection for the current study is ongoing. We believe that the cognitive maps of older adults experience greater decay over time than their younger peers and that certain attributes will be affected more than others (e.g., landmarks will be preserved, as shown by current data but with expected loss of topological fidelity). Understanding how the cognitive map changes over time will allow for development of compensatory technologies to mitigate related safety and orientation problems.


National Science Foundation Awards Dr. Hahmann $175,000 Research Grant to Advance Spatial Artificial Intelligence

April 25th, 2016

The National Science Foundation (NSF) has awarded Dr. Torsten Hahmann from the School of Computing and Information Science a $175,000 research grant for the project “Empowering Multi-Conceptual Spatial Reasoning with a Repository of Qualitative and Quantitative Spatial Ontologies”.

“Just over the hill” or “downstream” are phrases that are commonly used by people to communicate location to each other. We take these basic instructions for granted in day-to-day life. But how can these instructions be used for computing? This question has profound implications for computing and artificial intelligence, and has inspired Dr. Torsten Hahmann to search for answers.

The two-year long project develops techniques for computers to flexibly and reliably deal with a wide range of informal spatial descriptions such as “east of the road” or “at the south shore of the lake”. Dr. Hahmann’s will investigate computational mechanisms that connect such descriptions to more traditional coordinate-based spatial information used in satellite mapping or GPS devices.

His research will also develop methods that enable computers to figure out what implicit assumptions are made in such informal spatial descriptions. For example, a simple piece of information such as “X is contained in the lake” may take on very different spatial meanings in different contexts. If X is a bay, it means that it consists of a portion of the lake’s water, whereas if X is an island, it means it is surrounded by the lake water, but does not consist of water itself. Once a computer better understands such descriptions, it can add missing information from existing maps. In the long term, the research will make computational tools for recording, processing, and searching through spatial information much more powerful and user-friendly.

The project will support two graduate students and it will offer opportunities for undergraduate students to get involved in cutting edge research.

More information about the project is available at