6,659 research outputs found

    A semantic web approach for built heritage representation

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    In a built heritage process, meant as a structured system of activities aimed at the investigation, preservation, and management of architectural heritage, any task accomplished by the several actors involved in it is deeply influenced by the way the knowledge is represented and shared. In the current heritage practice, knowledge representation and management have shown several limitations due to the difficulty of dealing with large amount of extremely heterogeneous data. On this basis, this research aims at extending semantic web approaches and technologies to architectural heritage knowledge management in order to provide an integrated and multidisciplinary representation of the artifact and of the knowledge necessary to support any decision or any intervention and management activity. To this purpose, an ontology-based system, representing the knowledge related to the artifact and its contexts, has been developed through the formalization of domain-specific entities and relationships between them

    Knowledge Construction of 3D Geometry Concepts and Processes Within a Virtual Reality Learning Environment

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    A consensus has emerged within the mathematics education community about the limitations of traditional approaches for teaching and learning 3D geometry. Therefore, it has been suggested that new approaches based on the use of computers need to be adopted. One such new approach that has been proposed utilises Virtual Reality Learning Environment (VRLE). This paper reports on the initial phases of a research study whose major aim is to design and evaluate a VRLE to facilitate the construction of knowledge about 3D geometry concepts and processes. This research study investigates two primary school students’ construction of 3D geometry knowledge whilst engaged within a VRLE developed by the researcher. A design experiments research methodology was employed in this study. This is research that iterates through cycles of design and research with the objective of arriving at theoretical and design principles that will have application both within and beyond the immediate research study. Therefore, the results being reported in this paper will be used to inform the modification not only of the VRLE but also of theoretical frameworks underlying the design and implementation of VRLEs

    Generic unified modelling process for developing semantically rich, dynamic and temporal models

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    Models play a vital role in supporting a range of activities in numerous domains. We rely on models to support the design, visualisation, analysis and representation of parts of the world around us, and as such significant research effort has been invested into numerous areas of modelling; including support for model semantics, dynamic states and behaviour, temporal data storage and visualisation. Whilst these efforts have increased our capabilities and allowed us to create increasingly powerful software-based models, the process of developing models, supporting tools and /or data structures remains difficult, expensive and error-prone. In this paper we define from literature the key factors in assessing a model’s quality and usefulness: semantic richness, support for dynamic states and object behaviour, temporal data storage and visualisation. We also identify a number of shortcomings in both existing modelling standards and model development processes and propose a unified generic process to guide users through the development of semantically rich, dynamic and temporal models

    3D City Models and urban information: Current issues and perspectives

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    Considering sustainable development of cities implies investigating cities in a holistic way taking into account many interrelations between various urban or environmental issues. 3D city models are increasingly used in different cities and countries for an intended wide range of applications beyond mere visualization. Could these 3D City models be used to integrate urban and environmental knowledge? How could they be improved to fulfill such role? We believe that enriching the semantics of current 3D city models, would extend their functionality and usability; therefore, they could serve as integration platforms of the knowledge related to urban and environmental issues allowing a huge and significant improvement of city sustainable management and development. But which elements need to be added to 3D city models? What are the most efficient ways to realize such improvement / enrichment? How to evaluate the usability of these improved 3D city models? These were the questions tackled by the COST Action TU0801 “Semantic enrichment of 3D city models for sustainable urban development”. This book gathers various materials developed all along the four year of the Action and the significant breakthroughs

    IT Modeling Experience in Urban and Regional Development

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    Contemporary world increased dynamics forcing accordingly every human activity leaving none outside this never-ending race. Regional development is certainly strongly influenced by this trend challenging regional and urban planning techniques to cope with that. Acceleration of a working context and ambient accompanying with significant complexity are reasons, not only reasons however, for new evaluation and consequent advancement of current urban development planning methodologies. Shortage of a new appropriate techniques and methodology is apparent. Methodology that is able to respond quickly and efficiently to changes, independently from social and cultural context, toward to current development trends. Current planning techniques are based on accustomed mixture of verbal and informal graphic and symbolic language. In the same time research substance if exceptionally complex, heterogeneous and substantial retaining numerous different parameters with rich relationships matrix, required to consider and study in order to fulfill the designated outcome through firmly defined set of activities. One of most difficult problems is spatial dynamics since it is hard to recognize and identify and accordingly difficult to describe and control. Consequently, advancement of a planning methodology is essential to manage all listed inconsistence and weakness i.e. a new planning methodology is mandatory. This objective will certainly require a fundamental breach and change of current planning techniques demand and new interdisciplinary approach and research. Similar complexity level, vast list of parameters with complex and heterogeneous structural and dynamic relationship scheme, may be found in information and telecommunication systems i.e. computer based systems. Information and Telecommunication Technology (ICT in further text) uses object oriented methodology, for analysis and design as well, (OO in further text) to cope with the complexity, scope and heterogeneity of a systems. Latest step in this direction is a Unified Modeling Language (UML in further text) as a cohesive graphic and formal language for system description. UML is adopt as an industry standard and today is almost inevitable in every even modest ICT project. Paper illustrates basic building block of OO methodology and UML, and theirs many years of positive experience and encouraging results, intending to exploit this in an urban spatial planning domain. Higher perception and description level, enhanced knowledge and improved control over the urban development are main objective. However authors do not consider direct, as is, implementation of OO methodology and UML to the problem of urban and regional development. Localization and adjustment to the problem domain is advisory. This is already accomplished for several other vertical industries as joint effort of local experts and OO/UML professionals. Main goal is to apply currently acquired OO/UML experience and knowledge to the urban and regional development problem domain. This interdisciplinary research will be, evidently, long, complex and expensive process but we believe that this direction promises a significant progress for urban planning. Urban ambient formal specification, founded on OO/UML modeling methodology, may accumulate experience and knowledge presenting it to the audience, introducing computer added urban planning and, may be in the future, urban ambient simulation

    An ontology-based approach towards coupling task and path planning for the simulation of manipulation tasks

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    This work deals with the simulation and the validation of complex manipulation tasks under strong geometric constraints in virtual environments. The targeted applications relate to the industry 4.0 framework; as up-to-date products are more and more integrated and the economic competition increases, industrial companies express the need to validate, from design stage on, not only the static CAD models of their products but also the tasks (e.g., assembly or maintenance) related to their Product Lifecycle Management (PLM). The scientific community looked at this issue from two points of view: - Task planning decomposes a manipulation task to be realized into a sequence of primitive actions (i.e., a task plan) - Path planning computes collision-free trajectories, notably for the manipulated objects. It traditionally uses purely geometric data, which leads to classical limitations (possible high computational processing times, low relevance of the proposed trajectory concerning the task to be performed, or failure); recent works have shown the interest of using higher abstraction level data. Joint task and path planning approaches found in the literature usually perform a classical task planning step, and then check out the feasibility of path planning requests associated with the primitive actions of this task plan. The link between task and path planning has to be improved, notably because of the lack of loopback between the path planning level and the task planning level: - The path planning information used to question the task plan is usually limited to the motion feasibility where richer information such as the relevance or the complexity of the proposed path would be needed; - path planning queries traditionally use purely geometric data and/or “blind” path planning methods (e.g., RRT), and no task-related information is used at the path planning level Our work focuses on using task level information at the path planning level. The path planning algorithm considered is RRT; we chose such a probabilistic algorithm because we consider path planning for the simulation and the validation of complex tasks under strong geometric constraints. We propose an ontology-based approach to use task level information to specify path planning queries for the primitive actions of a task plan. First, we propose an ontology to conceptualize the knowledge about the 3D environment in which the simulated task takes place. The environment where the simulated task takes place is considered as a closed part of 3D Cartesian space cluttered with mobile/fixed obstacles (considered as rigid bodies). It is represented by a digital model relying on a multilayer architecture involving semantic, topologic and geometric data. The originality of the proposed ontology lies in the fact that it conceptualizes heterogeneous knowledge about both the obstacles and the free space models. Second, we exploit this ontology to automatically generate a path planning query associated to each given primitive action of a task plan. Through a reasoning process involving the primitive actions instantiated in the ontology, we are able to infer the start and the goal configurations, as well as task-related geometric constraints. Finally, a multi-level path planner is called to generate the corresponding trajectory. The contributions of this work have been validated by full simulation of several manipulation tasks under strong geometric constraints. The results obtained demonstrate that using task-related information allows better control on the RRT path planning algorithm involved to check the motion feasibility for the primitive actions of a task plan, leading to lower computational time and more relevant trajectories for primitive actions
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