Psychological Time and the Processing of Spatial Information
Richard A. Block
The focus of this paper, rather than on space providing a framework for time, is on how time perception might provide a framework for space perception. Important distinctions are made between position and duration, personal experiences vs. general knowledge, and prospective vs. retrospective. A contextualistic model of temporal, and by extension, spatial experience is proposed. The model looks at how several variables interact to influence duration and other kinds of temporal experiences, behaviors and judgments. The variables included personal characteristics of the experimenter, contents of time period, activities during the time period and temporal behavior. This model can be extended to space.
Morphological, Topological, and Chronological Time in Urban Development
Irene Campari
This paper proposes a view of the town development as a dynamic and continuous process manifest in actions and events provided with limited duration. The historical time becomes only a support for the analysis of the relationship between some spatio-temporal event of urban space. This approach has been fruitfully applied to geology and landscape analysis. The idea of time as sequence of actions replaces the idea of time as continuous. Continuous means in the present case that the processes in time have a continuous manifestation in space. Each action, provided with duration, interacts with physical entities and artifacts Determining the duration means finding the functional constraints limiting the actions or activities on urban space. Some of these constraints are identified with the notion of topological time. An application of those concepts to urban development is exemplified with material from and extensive case study.
Beyond the Snapshot: Changing the Approach to Change, Error, and Process
Nicholas R. Chrisman
This paper considers three issues germane to incorporating the temporal dimension into a GIS: change and error in static images of the earth (e.g., satellite images), the underlying processes, and the influences of organizational issues on the conduct of change detection studies. The goal of this discussion is to foster changes in the procedures currently used to detect change. The author contends that the snapshot and one-shot survey must be replaced with a routinely-maintained system of geographic information, which will provide access to the actual changes as they occur. Analysis of change should focus on the actual processes that produce changes.
Exploring Temporal Continuity in Qualitative Spatial Calculi
A. G. Cohn, Z Cui, and D. A. Randell
This paper summarizes research aimed to evaluate, extend and implement a theory of space and time which is based upon calculus of individuals based on connection and is expressed in the many sorted logic LLAMA. This theory supports regions having either a spatial or temporal interpretation where the regions can be perceived to be infinite in number and any degree of connection from external contact to identity is allowed in the model. The formal theory assumes a primitive dyadic relation: C (x,y) read as "x connects with y" which is defined on regions. C is reflexive and symmetric. In terms of points incident in regions, C (x, y) holds when regions x and y share a common point. Using the relation C, a basic set of dyadic relations are defined: disconnected from (DC), part of (P), proper part of (PP), identical with (=), overlaps (O), discrete from (DR), partially overlaps (PO), externally connected with (EC), tangential part of (TP), nontangential part of (NTP), tangential proper part of (TPP), nontangential proper part of (NTPP), the identity tangential part of (TPI), and the identity nontangential part of (NTPI).
Making Space for Time: Towards a Truly Temporal Geography
Helen Couclelis
In this paper, the author proposes a modeling framework to integrate time into GIS. This framework is based on Zeigler's formal specification of discrete-time and discrete-event systems. This framework involves integrating process with spatio and temporal dimensions because space, time and process are inextricably interrelated. Space and time are treated as taxonomic frames whose definitions are constrained by the tasks, events, experiences, or phenomena they help to organize. In other words, there are as many definitions of time and space as there are phenomena, and a universal definition is unlikely. As GIS reflects a commitment to an absolute Newtonian space, the framework proposed here mirrors that commitment. Integration of time in GIS according to this framework is from a physicalist view of the world. The author discusses how discrete-time systems favor raster GIS, and how discrete-event systems favor vector GIS.
Geometric Approaches to the Nexus of Time, Space and Microprocess: Implementing a Practical Model for Mundane Socio-Spatial Systems
Pip Forer
This paper focuses on the inter-relationship and substitutability of space and time in human spatial processes. Its aim is to identify a practical means of implementing a specific range of analyses in respect of such processes, basing the temporal query part of such analyses on geometric properties rather than a data base approach. In doing this it views a geometric rather than and attribute approach.
Different Types of "Times" in GIS
Andrew U. Frank
This paper provides a brief review of the progress that has been made with the modeling of space, and is followed by a listing of several links between the modeling of space and time. Stress is put on the linkage between the process considered and space and time model used. A number of seemingly orthogonal characteristics of time models and properties of the respective processes are listed (and these are related to the corresponding spatial conceptual models). Then contrasts are made between the paradigm of reality for science and for administration, and major differences between these paradigms which strongly influence the temporal logic and the operations that are necessary for updating a model in administration are observed.
Temporal and Other Issues in Qualitative Spatial Reasoning
Christian Freksa
The focus of this paper is to explore qualitative spatial reasoning in a natural language system. The properties of physical space and time structure our knowledge about static situations and dynamic events in a fundamental way. Taking these concrete properties into account when processing knowledge about spatial and temporal situations--as well as knowledge which refers to situations and events--may result in substantial cognitive, inferential, and computational advantages. The author discusses methods under development for the direct representation and processing of spatial and temporal properties in computer systems. These methods include direct spatial and temporal reasoning on the basis of coarse knowledge, and a neighborhood-based approach to qualitative spatial reasoning which focuses on spatial aspects which actually are accessible in real problem solving situations; for example, relative orientation and distance information.
Cognitive Distance at Various Geographic Scales
Scott M. Freundschuh
The focus of this paper was to explore how people normally think about and express cognitive distance in their everyday lives. This approach was in contrast to previous studies in which subject testing occurred in unnatural experimental situations where subjects were constrained as to the kind of answers they could provide (i.e., provide distance estimate, provide time estimate). In this study, an experiment was designed to explore when, in a conversational setting, people used time vs. space to estimate distances. Subjects, who were not aware that they were being tested, were queried during a typical conversation about how far it was to other places. The results indicated an inverted U-shaped curve that suggests that time is used for intermediate distance estimates (331km - 2080km), and space is used for short (< 10km) and very long distances (8000km).
Some Operational Requirements for a Multi-Temporal 4-D GIS
N.W.J. Hazelton
This paper discusses some of the operational requirements of a multi-temporal 4-D GIS, and describes the role of the data structure and software architecture in realizing these requirements. There is assumed to be a strong dependency between the software architecture and the data structure, as in a "whole" GIS.
Process Dynamics, Temporal Extent, and Causal Propagation as the Basis for Linking Space and Time
John A. Kelmelis
In this paper, the author points out the increasing demand for GIS to understand dynamic geographic phenomena, therefore, the need to incorporate the variables necessary to model processes into geographic data and information. Example's of dynamic phenomena are climate change, climate variability, disaster propagation, and environmental epidemiology. Key to modeling these dynamic phenomena is understanding that the process dynamics can vary significantly from process to process (i.e., from phenomena to phenomena). A relationship exists between the temporal extent of an event and the event's sustained causal propagation and the intensity of its effects. A function (Es = f (Et, te, Vcp, A)) that links the spatial and temporal extent of processes is illustrated. This function provides a systematic framework for linking space and time in geographic and process modeling. The author suggests that such a linkage will help in cause and effect analysis, predictive modeling, and process and spatio-temporal feature boundary identification. Use of this function will make inclusion of some dynamic processes in GIS more effective.
Spatio-Temporal Reasoning in Atmospheric Science Databases
Siu-Wah Lau, Richard R. Muntz, Eddie C. Shek, Carlo Zaniolo, and Son K. Dao
In this paper, the authors characterize the need for performing spatio-temporal analysis and queries on very large databases as ubiquitous in diverse applications ranging from earth and space sciences to resource exploration, selective marketing and sales analysis. They report on a project with atmospheric scientists designed to develop systems and techniques for detecting and tracking evolving physical phenomena on massive data sets produced by combined atmospheric and ocean global models. Toward these goals, the authors propose spatial extensions to LDL++, a system that supports rule-based reasoning and expert application development for databases, and Event Pattern Language (EPL), which is designed to detect sequences of temporal events. The integration of these systems provides a computing environment where complex queries and reasoning on spatial and temporal data to be easily expressed and efficiently supported. The authors also discuss the problem of indexing such databases for efficient query processing and describe the use of EPL to provide intelligent active indexing capabilities.
A New Framework for Understanding the Acquisition of Spatial Knowledge in Large-Scale Environments
Daniel R. Montello
In this paper, the author argues for a modification of the simplistic landmark/route/survey distinction (which he termed the dominant framework) of spatial knowledge, and offers a new framework comprised of five major tenets. The first is that there is no stage at which only pure landmark or route knowledge that contains no metric information about distance and direction exists. Metric configurational knowledge begins to be acquired on first exposure to a novel place. The second tenet suggests that with increasing familiarity and exposure to places, there is a relatively continuous increase in the quantity [quantitative rather than qualitative shift], accuracy, and completeness of spatial knowledge. The third tenet indicates that the integration of knowledge about separately-learned places into more complex hierarchically-organized knowledge structures represents a significant and relatively sophisticated step in the microgenesis of spatial knowledge. The fourth tenet suggests that individuals with equal levels of exposure to an environment will differ in the extent and accuracy of their spatial knowledge. The final tenet indicates that linguistic systems for storing spatial knowledge provide for the existence of relatively pure topological knowledge, or at least non-metric knowledge. However, such non-metric knowledge exists in addition to metric spatial knowledge, not as a necessary precursor or intrinsic part of it.
Longitudinal Analysis of Migration and Mobility Behavior: Investigations of Spatial Choices in an Explicitly Temporal Context
John Odland
This paper is a review and analysis for longitudinal modeling of spatial behavior, with an emphasis on the ways that adoption of an explicitly temporal context transforms problems and procedures in this area of research. This is a relatively new research area in which traditional questions about spatial decision making, especially migration and mobility behavior, are being placed in an explicitly temporal context: that of continuous locational histories for individuals. The emphasis in the paper is on the ways that adoption of an explicitly temporal framework for analyses of spatial behavior mandates some very basic changes in the definition of research problems, the formulation of hypotheses, and the application of statistical methods to problems of estimation and hypothesis testing.
Seeing Time
Guiseppe Papagno
In this paper, the author asserts that we need space to talk about time, and vise-versa. Looking at the effects of man on the landscape over time is one way to model changes in space over time. A dynamic conceptual model composed of the three elements material, activity and function is proposed to define geographic features (objects). All objects have a material structure, transmit an activity of relationship in space, and exert a function which justifies the existence in time of a material and of an activity for itself in its environment. This model is illustrated with an example of the Visdende Valley which is a remote valley in Northern Italy. Policies concerning the forbidden harvesting of lumber in the Valley that date back several centuries can be used to explain why even though the tress are certainly "ripe for cutting," they remain untouched. In the seventeenth century, general exploitation of the trees was prohibited to preserve the trees for use in constructing ships of the Arsenale.
Path, Points, and Proforms
Háj Ross
This paper focuses on motion in general, and on syntactic and semantic structures expressing paths of movement, in particular. A model is proposed wherein the description of a moving object's path can be composed of the eight elements of source (from), trajectory (physical route), direction, distance, speed, totality (from A to B), goal (destination) and mode (method of transport). The author addresses a number of conceptual organizational issues concerning these elements such as, "Are all eight of these elements on the same level of the hierarchy of phrase structure?" Several possible organizational structures are proposed and supported with examples from the literature.
A Representation Framework for Route Planning in Space and Time
Stephen Smyth
This paper describes a conceptual development of a research environment for future Geographic Information Systems (GIS). This environment separates architecture from representation. Many useful spatial and geographic applications require a combination of spatial and temporal representations, version management, inference mechanisms, user interface management, and communications. If there were a framework for integrating applications consisting of standardized interfaces to a spatial-temporal representation, to an inference mechanism, to a user interface, and to communication services, then a second, orthogonal structure might formalize the relationship between abstract representational theories and the concrete concerns of software engineering. Spatial representation in such an environment should encompass the usual elements of surveying and cartography, as well as the mathematical details of capturing form and relationships in a Euclidean three-space. Temporal representation should allow for time recording and naming conventions as they exist in a multicultural world, with alternative calendars. Versioning should allow for alternative views of reality.
Temporal Dynamics and Geographical Information Systems
Stephen D. Stead
In this paper, the author contends that the real world operates along a time line, which is a single ordered line upon which the temporal extent of data values are plotted. The domain of this research focuses on systems to deal with modeling time in archeological. An alternative method to the standard time-slicing technique which stores snapshots of the landscape which are used as interpretive back-cloths is proposed. This alternative model is to represent known data elements in four dimensions (x, y, z, and t) rather than the conventional three dimensions. From these, real world processes can be modeled. An object-oriented approach is used to model geographical features (objects).
Present and Future Diurnal Circulation of Population in a Large City
Frederick P. Stutz, Robert Parrott, and Paul Kavanaugh
This paper reports a study in which travel diaries were administered to 2754 households in San Diego by the San Diego Association of Governments (SANDAG) on day in 1986. These surveys are used to document population shifts throughout the 24-hour day and for documenting the maximum population for each census tract. To develop the formula for estimating populations in time and space, factors of trips by time of day and type of trip (e.g., home-to-work and home-to-shop) were elucidated from the travel behavior survey. These factors were then applied to the daily trip productions and trip attractions obtained from the standard trip generation models used by the California Department of Transportation (CALTRANS). The population data input to produce the 1986 estimates is also available to generate daytime population estimates for 1995, 2000, 2010. Such time-space charting is absolutely essential if urban areas are to be prepared to first, meet the service demands of a mobile urban population, and second, to manage evacuation procedures for earthquakes, flooding, or nuclear attack.
Acquiring and Updating Spatial Knowledge from Language
Barbara Tversky
In this paper, the authors discuss the results of several experiments designed to assess spatial knowledge acquired from narrative. In the first experiment, subjects read route or survey descriptions of naturalistic environments, after which they answered verbatim or inference questions that required either route or survey knowledge to answer. Verbatim statements were verified faster than responses to inference questions, but there were no differences in responses to inference questions dependent on the route/survey distinction. This suggests a single representational schema, regardless of how spatial information is acquired. In a second experiment, Tversky (with Franklin and Bryant) explored spatial knowledge acquisition from small scale scenes described in narrative where objects in the scenes were described in terms of up/down, front/back, and left/right of a protagonist. Results supported the spatial framework model which purports that space is conceptualized in terms of three axes corresponding to bodily position.
The Representation of Spatio-Temporal Variation in GIS and Cartographic Displays: The Case for Sonification and Auditory Data Representation
Christopher R. Weber
This paper reviews the relatively brief literature on Auditory Data Representation (ADR) and the strengths of this medium to enhance visual depictions of spatio-temporal change. The focus of this paper was the application of ADR in cartographic representations. Preliminary work by the authors to measure subject association of complex harmonic intervals with various adjective pairs which might describe continua of cartographic conditions or variables indicated that the time-dependent variables of constant-variable and static-wavering scored most highly for subject ranking by relative consonance (which is determined by the constructive and destructive wave interference between two frequencies).
A Generic Model for Spatio-Bitemporal Geographic Information
Michael F. Worboys
This paper describes work in progress on the construction of a generic object model for a GIS which handles objects with both references to embeddings in two orthogonal spatial dimensions and two orthogonal temporal dimensions. An embedding in 2D Euclidean space is assumed for spatial references, and the two orthogonal dimensions of real (or event or valid) time and transaction or database time are used to handle temporal information. Bitemporal elements are used to extend purely spatial theory to include temporal referencing. Bitemporal objects (ST-complexes) capable of representing simultaneously the structure of the components of an information system which may vary in two spatial and two temporal dimensions are employed.