318,580 research outputs found

    A New Definition for the Concept of Role, and Why it Makes Sense

    Get PDF
    There is widespread agreement in the object community that the concept of role is important for object modelling, but little agreement about what is to be understood by a role. In this paper, we present a new definition for the concept of role in the context of ISOs RM-ODP Foundations for object modelling. We show that the concept of role is similar to that of interface, but that there important differences between these two concepts. We also provide definitions for concepts, related to the role concept, that may also be called roles: role type and role object type. We then make the case for our definitions, showing that they are largely compatible with assertions that exist in the literature about roles

    Improving data modelling through the use of case-based-reasoning

    Get PDF
    Experience plays an important role in Information Systems data modelling activity. This role is justified by the fact that determining the correct and consistent information requirements is a difficult and a challenging task. Currently three types of data modelling techniques are widely used: entity-attribute-relationship, object-relationship and object-oriented. There is not a consensus about which one is the best. This article proposes a framework, supported by a software tool, that uses Case-Based-Reasoning (CBR) methodology to represent and use experience in the data modelling task. The proposed framework does not depend on the data modelling technique nor on the modelling tool.- (undefined

    Conceptual Modelling and The Quality of Ontologies: Endurantism Vs. Perdurantism

    Full text link
    Ontologies are key enablers for sharing precise and machine-understandable semantics among different applications and parties. Yet, for ontologies to meet these expectations, their quality must be of a good standard. The quality of an ontology is strongly based on the design method employed. This paper addresses the design problems related to the modelling of ontologies, with specific concentration on the issues related to the quality of the conceptualisations produced. The paper aims to demonstrate the impact of the modelling paradigm adopted on the quality of ontological models and, consequently, the potential impact that such a decision can have in relation to the development of software applications. To this aim, an ontology that is conceptualised based on the Object-Role Modelling (ORM) approach (a representative of endurantism) is re-engineered into a one modelled on the basis of the Object Paradigm (OP) (a representative of perdurantism). Next, the two ontologies are analytically compared using the specified criteria. The conducted comparison highlights that using the OP for ontology conceptualisation can provide more expressive, reusable, objective and temporal ontologies than those conceptualised on the basis of the ORM approach

    Designing role-based view for object-relational databases

    Get PDF
    In a federated database system, a view mechanism is crucial since it is used to define exportable subsets of data ; to perform a virtual restructuring d ataset; and to construct the integrated schema. The view service in federated databa se systems must be capable of retaining as much semantic information as possible. The object-oriented ( 0 - 0 ) model was considered the suitable canonical data model since it meets the original criteria for canonical model selection. However, with the emergence of stronger object-relational (0 -R ) model, the re is a clear argument for using an 0 - R canonical model in the federation. Hence, research should now focus on th e development of semantically powerful view mechanism for th e newer model. Meanwhile, the availability of real 0 -R technologies offers researchers the opportunity to develop different forms of view mechanisms. The concept of roles has been widely studied in 0 - 0 modelling and development. The role model represents some characteristics that the traditional 0-0 model lacked, such as object migration, multiple occurrences and context-dependent access. While many forms of 0-0 views were designed for the 0-0 canonical model, one option was to extend the 0-0 model to incorporate a role model. In a role model, the real entity is modelled in the form of a role rather than an object. An object represents the permanent properties of an entity is a root object; and an object represents the temporary properties of an entity is a role object. The contribution of this research is to design a view system that employees the concept of roles for the 0 -R canonical model in a federated database system. In this thesis, an examination of the current 0 -R metamodel is provided first in order to provide an environment for recognising the roleview metadata and measuring the view performance; then a Roleview Definition Language (RDL) is introduced, along with the semantics for defining virtual classes and generating virtua l extents; finally, a working prototype is provided to prove th e role-based view system is implementable and the syntax is semantically correct

    Interactive Perception Based on Gaussian Process Classification for House-Hold Objects Recognition and Sorting

    Get PDF
    We present an interactive perception model for object sorting based on Gaussian Process (GP) classification that is capable of recognizing objects categories from point cloud data. In our approach, FPFH features are extracted from point clouds to describe the local 3D shape of objects and a Bag-of-Words coding method is used to obtain an object-level vocabulary representation. Multi-class Gaussian Process classification is employed to provide and probable estimation of the identity of the object and serves a key role in the interactive perception cycle – modelling perception confidence. We show results from simulated input data on both SVM and GP based multi-class classifiers to validate the recognition accuracy of our proposed perception model. Our results demonstrate that by using a GP-based classifier, we obtain true positive classification rates of up to 80%. Our semi-autonomous object sorting experiments show that the proposed GP based interactive sorting approach outperforms random sorting by up to 30% when applied to scenes comprising configurations of household objects

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

    Get PDF
    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

    Information parsimony in collaborative interaction

    Get PDF
    We investigate the information processing cost associated with performing a collaborative dyadic task at a specific utility level. We build our approach on the Relevant Information formalism, which combines Shannon's Information Theory and Markov Decision Processes, for modelling a dyadic interaction scenario in which two agents with independent controllers move an object together with fully redundant control. Results show that increasing dyad's collaboration decreases the information intake and vice versa, antagonistic behavior puts a strain on the information bandwidth capacity. The key role of the particular embodiment of the environment in this trade-off is demonstrated in a series of simulations with informationally parsimonious optimal controllers.Peer reviewedFinal Published versio

    R-CNN minus R

    Full text link
    Deep convolutional neural networks (CNNs) have had a major impact in most areas of image understanding, including object category detection. In object detection, methods such as R-CNN have obtained excellent results by integrating CNNs with region proposal generation algorithms such as selective search. In this paper, we investigate the role of proposal generation in CNN-based detectors in order to determine whether it is a necessary modelling component, carrying essential geometric information not contained in the CNN, or whether it is merely a way of accelerating detection. We do so by designing and evaluating a detector that uses a trivial region generation scheme, constant for each image. Combined with SPP, this results in an excellent and fast detector that does not require to process an image with algorithms other than the CNN itself. We also streamline and simplify the training of CNN-based detectors by integrating several learning steps in a single algorithm, as well as by proposing a number of improvements that accelerate detection

    A Foundation for the Concept of Role in Object Modelling

    Get PDF
    Standardization experts in object modelling are having difficulties with defining the concept of rol
    corecore