A qualitative approach to the identification, visualisation and interpretation of repetitive motion patterns in groups of moving point objects

Discovering repetitive patterns is important in a wide range of research areas, such as bioinformatics and human movement analysis. This study puts forward a new methodology to identify, visualise and interpret repetitive motion patterns in groups of Moving Point Objects (MPOs). The methodology consists of three steps. First, motion patterns are qualitatively described using the Qualitative Trajectory Calculus (QTC). Second, a similarity analysis is conducted to compare motion patterns and identify repetitive patterns. Third, repetitive motion patterns are represented and interpreted in a continuous triangular model. As an illustration of the usefulness of combining these hitherto separated methods, a specific movement case is examined: Samba dance, a rhythmical dance will? many repetitive movements. The results show that the presented methodology is able to successfully identify, visualize and interpret the contained repetitive motions

Modelling topological features of swarm behaviour in space and time with persistence landscapes

This paper presents a model of swarm behaviour that encodes the spatial-temporal characteristics of topological features such as holes and connected components. Specifically, the persistence of topological features with respect to time are computed using zig-zag persistent homology. This information is in turn modelled as a persistence landscape which forms a normed vector space and facilitates the application of statistical and data mining techniques. Validation of the proposed model is performed using a real data set corresponding to a swarm of fish. It is demonstrated that the proposed model may be used to perform retrieval and clustering of swarm behaviour in terms of topological features. In fact, it is discovered that clustering returns clusters corresponding to the swarm behaviours of flock, torus and disordered. These are the most frequently occurring types of behaviour exhibited by swarms in general

Environmental Analysis of the Residential Sector in Cairo

Rapid demographic increase and transition in governmental policies influenced the patterns of Egyptianresidential sector, services and urban fabric. The housing stock in Egypt is dominated by private owners, informally and high consumption rates. Studies attempted to classify historic periods that created the current urban pattern and led to an uncontrollable expansion of a metropolis. Political and demographic changes had a major role in the city’s urban, architectural and legislative transformation, especially after the change of government policies in 1953. The article aims to evaluate the development milestones of the housing stock in Cairo before and after 1953, from an environmental sustainability perspective on a building and urban scale. Based on official statistics, maps from various periods and literature, the urban development of the city is assessed. The impact of governmental policies and strategic plans is analyzed, taking into consideration demographic growth, urban sprawl and environmental aspects. The residential stock is classified in two time phases (before and after 1953) and three dominant typological -urban and architectural- criteria. Based on this classificatory model, representative characteristics of different periods are assessed in terms of morphology, construction materials and environmental design. The results provide a critical analysis of Cairo's environmental and sustainability policies in the second half of the previous century. It provides an evaluation base for comparison with the city's current built environment and offers guidance for future scenarios

A Classification of the Intersections Between Regions and their Topical Transitions

As two topological regions are morphed and translated, how does their intersection change? Previous research has been done on static configurations with planar spatial regions. I expand upon this research to include dynamically changing regions and intersections. I examine what forms of intersection are possible, and what transitions are directly possible, while considering such variables as the connectedness of the regions

QTC3D: extending the qualitative trajectory calculus to three dimensions

Spatial interactions between agents (humans, animals, or machines) carry information of high value to human or electronic observers. However, not all the information contained in a pair of continuous trajectories is important and thus the need for qualitative descriptions of interaction trajectories arises. The Qualitative Trajectory Calculus (QTC) (Van de Weghe, 2004) is a promising development towards this goal. Numerous variants of QTC have been proposed in the past and QTC has been applied towards analyzing various interaction domains. However, an inherent limitation of those QTC variations that deal with lateral movements is that they are limited to two-dimensional motion; therefore, complex three-dimensional interactions, such as those occurring between flying planes or birds, cannot be captured. Towards that purpose, in this paper QTC3D is presented: a novel qualitative trajectory calculus that can deal with full three-dimensional interactions. QTC3D is based on transformations of the Frenet-Serret frames accompanying the trajectories of the moving objects. Apart from the theoretical exposition, including definition and properties, as well as computational aspects, we also present an application of QTC3D towards modeling bird flight. Thus, the power of QTC is now extended to the full dimensionality of physical space, enabling succinct yet rich representations of spatial interactions between agents

Geospatial Narratives and their Spatio-Temporal Dynamics: Commonsense Reasoning for High-level Analyses in Geographic Information Systems

The modelling, analysis, and visualisation of dynamic geospatial phenomena has been identified as a key developmental challenge for next-generation Geographic Information Systems (GIS). In this context, the envisaged paradigmatic extensions to contemporary foundational GIS technology raises fundamental questions concerning the ontological, formal representational, and (analytical) computational methods that would underlie their spatial information theoretic underpinnings. We present the conceptual overview and architecture for the development of high-level semantic and qualitative analytical capabilities for dynamic geospatial domains. Building on formal methods in the areas of commonsense reasoning, qualitative reasoning, spatial and temporal representation and reasoning, reasoning about actions and change, and computational models of narrative, we identify concrete theoretical and practical challenges that accrue in the context of formal reasoning about `space, events, actions, and change'. With this as a basis, and within the backdrop of an illustrated scenario involving the spatio-temporal dynamics of urban narratives, we address specific problems and solutions techniques chiefly involving `qualitative abstraction', `data integration and spatial consistency', and `practical geospatial abduction'. From a broad topical viewpoint, we propose that next-generation dynamic GIS technology demands a transdisciplinary scientific perspective that brings together Geography, Artificial Intelligence, and Cognitive Science. Keywords: artificial intelligence; cognitive systems; human-computer interaction; geographic information systems; spatio-temporal dynamics; computational models of narrative; geospatial analysis; geospatial modelling; ontology; qualitative spatial modelling and reasoning; spatial assistance systemsComment: ISPRS International Journal of Geo-Information (ISSN 2220-9964); Special Issue on: Geospatial Monitoring and Modelling of Environmental Change}. IJGI. Editor: Duccio Rocchini. (pre-print of article in press

A categorical approach to time representation: first study on qualitative aspects

euzenat1995dInternational audienceThe qualitative time representation formalisms are considered from the viewpoint of category theory. The representation of a temporal situation can be expressed as a graph and the relationship holding between that graph and others (imprecise or coarser) views of the same situation are expressed as morphisms. These categorical structures are expected to be combinable with other aspects of knowledge representation providing a framework for the integration of temporal representation tools and formalisms with other areas of knowledge representation