36768622
An Ontological Metamodel of Classifiers and Its Application to Conceptual Modelling and Database Design
Classification is a key concept in conceptual modeling. However, the recognition that there might be different kinds of classes has received limited attention in conceptual modeling research. Most work has focused on the concept of role. However, confusion exists on the definition, properties, and representation of role. In this paper, we propose a metamodel of classifiers based on ontological foundations. We focus on the notion of role in the object-oriented and conceptual modeling literature. The metamodel conforms to the fundamental role features identified in the literature and handles several problems associated with role modeling. Furthermore, we contrast conceptual models created using our metamodel to those created using traditional ER or class modeling approaches, and highlight the database design implications of the differences. Using examples, we demonstrate that relational database schemata generated using our approach are more stable with respect to changing requirements.
39978783
Conceptual Modeling in Systems Development: Should it Be Driven by User's or Designer's Needs? (Panel discussion)
38919704
How UML is used
Many UML projects are not Use Case driven.
33060122
Attribute-Based Semantic Reconciliation of Multiple Data Sources
The main challenge in information integration is reconciling data semantics. Semantic reconciliation usually follows one of two approaches. Schema-based approaches assume instances belong to types and use schema information to reconcile types before reconciling attributes and relationships of these entity types. Attribute-based approaches use attribute names and nom-semantic information, such as ranges of attribute values, to seek similarities in attributes across sources. We suggest an attribute-based approach that uses semantic information. Two principles guide our method. First, reconciliation does not require that instances belong to specific types. Instead, sources can be reconciled by analyzing properties. Second, properties that appear different may be manifestations of the same higher-level property, enabling the treatment of inter-sources attributes, with different names and value ranges, as specializations of a more gemeral attribute. We discuss the approach, analyze its potential advantages, suggest a formalization, demonstrate its use with examples, and suggest directions for further research.
1235359
An Experimental Evaluation of Property Precedence in Conceptual Modelling
Interest in evaluating conceptual modelling techniques has recently experienced a revival, in part due to widespread adoption of the Unified Modelling Language (UML). In addition, the use of ontology as a framework for evaluating conceptual modelling techniques has gained acceptance. In this paper, we consider implications of applying one aspect of the ontology of Mario Bunge to conceptual modelling. Specifically, conceptual modelling has traditionally failed to provide mechanisms to indicate that some properties of types or classes may be considered dependent on others. This paper presents a theoretical rationale, using Bunge's ontological notion of precedence, for explicitly modelling such dependence in conceptual schema diagrams. We present the design of an experimental framework to test the impact of explicitly representing precedence on the ease with which a diagram can convey domain semantics. In addition, we consider how the issue of "common sense" semantics can interfere with experimental procedures to evaluate the semantics conveyed in a diagram's structure. We offer early experimental results indicating: 1) the explicit modelling of precedence improves the ability of experimental participants to verify the existence of dependence among properties (but has no effect on the ability to verify the semantics conveyed by association cardinalities); and 2) the potential for background knowledge to interfere with the semantics conveyed by diagram structure. We conclude by discussing the need for further research on both these issues.
39735656
What Is the Role of Cognition in Conceptual Modeling? A Report on the First Workshop on Cognition and Conceptual Modeling
Conceptual modeling has been advocated as an approach for representing the subject matter of an information system in a way that better reflects the way users think about that subject matter. Therefore, conceptual modeling appears to have a natural cognitive basis. However, there has been a surprising lack of attention in conceptual modeling research to cognitive issues and the role of cognition in both the development and evaluation of conceptual modeling techniques. The objective of the First Workshop on Cognition and Conceptual Modeling was to bring together researchers studying a wide range of questions relevant to the conference theme. This paper summarizes the motivation for the workshop, the presentations made, and outlines the workshop's contribution to furthering our understanding of the role of cognition in conceptual modeling.
7550336
Model driven middleware: A new paradigm for developing distributed real-time and embedded systems
Distributed real-time and embedded (DRE) systems have become critical in domains such as avionics (e.g., flight mission computers), telecommunications (e.g., wireless phone services), tele-medicine (e.g., robotic surgery), and defense applications (e.g., total ship computing environments). These types of system are increasingly interconnected via wireless and wireline networks to form systems of systems. A challenging requirement for these DRE systems involves supporting a diverse set of quality of service (QoS) properties, such as predictable latency/jitter, throughput guarantees, scalability, 24x7 availability, dependability, and security that must be satisfied simultaneously in real-time. Although increasing portions of DRE systems are based on QoS-enabled commercial-off-the-shelf (COTS) hardware and software components, the complexity of managing long lifecycles (often ~15-30 years) remains a key challenge for DRE developers and system integrators. For example, substantial time and effort is spent retrofitting DRE applications when the underlying COTS technology infrastructure changes. This paper provides two contributions that help improve the development, validation, and integration of DRE systems throughout their lifecycles. First, we illustrate the challenges in creating and deploying QoS-enabled component middleware-based DRE applications and describe our approach to resolving these challenges based on a new software paradigm called Model Driven Middleware (MDM), which combines model-based software development techniques with QoS-enabled component middleware to address key challenges faced by developers of DRE systems - particularly composition, integration, and assured QoS for end-to-end operations. Second, we describe the structure and functionality of CoSMIC (Component Synthesis using Model Integrated Computing), which is an MDM toolsuite that addresses key DRE application and middleware lifecycle challenges, including partitioning the components to use distributed resources effectively, validating software configurations, assuring multiple simultaneous QoS properties in real-time, and safeguarding against rapidly changing technology.