6980198
A combined approach to checking web ontologies
The understanding of Semantic Web documents is built upon ontologies that define concepts and relationships of data. Hence, the correctness of ontologies is vital. Ontology reasoners such as RACER and FaCT have been developed to reason ontologies with a high degree of automation. However, complex ontology-related properties may not be expressible within the current web ontology languages, consequently they may not be checkable by RACER and FaCT. We propose to use the software engineering techniques and tools, i.e., Z/EVES and Alloy Analyzer, to complement the ontology tools for checking Semantic Web documents.In this approach, Z/EVES is first applied to remove trivial syntax and type errors of the ontologies. Next, RACER is used to identify any ontological inconsistencies, whose origins can be traced by Alloy Analyzer. Finally Z/EVES is used again to express complex ontology-related properties and reveal errors beyond the modeling capabilities of the current web ontology languages. We have successfully applied this approach to checking a set of military plan ontologies.
207130315
Formal Designs for Embedded and Hybrid Systems
The design of embedded and hybrid systems requires powerful mechanisms for modeling data, state, concurrency and real-time behaviour. The {first} part of this paper illustrates a powerful design notation Timed Communicating Object Z (TCOZ) that has both channel based and sensor/actuator based interfaces. We believe that TCOZ is well suited for presenting more complete and coherent design models for complex embedded and hybrid systems. However, the challenge is how to analyze and check these models with tools support. One effective approach is to project (transform) the design models into multiple domains, then to use existing specialized tools in those domains to perform the checking and analyzing tasks. The second part of this paper demonstrates one particular projection from TCOZ designs to Timed Automata (TA) models so that TA model checkers can be used to check time related properties.
18404140
Deep Semantic Links of TCSP and Object-Z: TCOZ Approach
Abstract. Formal methods can be used in effective combination only if the semantic links between individual methods are clearly established. This paper discusses the semantic design of TCOZ, a language blended from Object-Z and TCSP. The semantic model adopted is the infinite timed failures model of TCSP, extended to include initial state and update events for modelling operations on internal state. An infinite trace model has been used so as to ensure proper account is taken of the potentially unbounded non-determinism allowed by Z schemas.
5239234
The role of secondary attributes in formal object modelling
When modelling a large and complex system, clarity of the specification becomes an important factor. In object-oriented specification, the states of individual objects are captured by the values of their attributes. Frequently however, there are dependencies between the attributes of an object. An appropriate indication of which attributes are primary (independent) and which are secondary (dependent) can add significantly to clarity. This paper details the notion of secondary attributes, their roles and implications in formal object-oriented specification.
10062286
Integrating Object-Z with timed automata
When designing a complex system, Object-Z is a powerful logic-based language for modeling the system state aspects, and timed automata is an excellent graph-based notation for capturing timed control behaviour of the system. This paper presents an effective combination of the two techniques with novel composition and communication mechanisms. The combined notation enhances Object-Z with realtime modeling capability and also extends timed automata with enhanced structure and state modeling features.
18649413
Capturing periodic concurrent interactions of mission computer tasks
Safety critical systems, such as aviation systems controlled by software, often have hard real-time requirements. Producing the correct result at the right time is the fundamental goal of such systems. Formally specifying the system functions and the timing requirements is the crucial step towards achieving such a goal. Aviation systems often need to be modified or upgraded on a regular basis, i.e. functionality and timing constraints may be altered. Therefore, the formal specification of such systems needs to be easily reused, maintained and modified. This paper demonstrates how the task scheduling aspects of an aircraft mission computer can be formalised in TCOZ.
168887
On analysis of design component contracts: a case study
Software patterns are a new design paradigm used to solve problems that arise when developing software within a particular context. Patterns capture the static and dynamic structure and collaboration among the components in a software design. A key promise of the pattern-based approach is that it may greatly simplify the construction of software systems out of building blocks and thus reuse experience and reduce cost. However, it also introduces significant problems in ensuring the integrity and reliability of these composed systems because of their complex software topologies, interactions, and transactions. There is a need to capture these features as a contract through a formal model that allows us to analyze pattern-based designs. In this paper, we provide a formal framework for ensuring the integrity of the compositions in object-oriented designs by providing mathematically rigorous modeling and analysis techniques for object-oriented systems comprising pattern-based designs as the basic building blocks or design components. A case study related to a hypermedia Web-based application is presented to illustrate our approach in distributed systems.
10543361
Commutability of Design Pattern Instantiation and Integration
Design patterns capture expert design experience in generic design structure and behavior. A design pattern needs to be instantiated before using. It can be integrated with other patterns as well. The instantiation and integration operations are two important operations when a designer uses a design pattern in a particular application. In this paper, we investigate the commutability of these two operations based on our formal specification framework. We provide rigorous proofs on the conditions when the order of these two operations does not matter. Our results enable the software designers to choose their design processes with assurance of their equivalence.
17418612
Visualizing design patterns with a UML profile
In this paper, we present a UML profile which defines new stereotypes, tagged values and constraints for visualizing design patterns in UML diagrams. These new stereotypes and tagged values are attached to a modeling element to explicitly represent the role the modeling element plays in a design pattern so that the user can identify the pattern in a UML diagram.
18879642
A Component Framework for Resource Management Systems
Resource management is a complex process in many business organizations. Current solutions are typically in a case-by-case manner. In this paper, we present a general component framework for resource management such that different applications can be instantiated from the framework.
17533115
A Behavioral Analysis Approach to Pattern-Based Composition
This paper introduces a rigorous analysis approach to software design composition based on automated verification techniques. We show how to represent, instantiate and integrate design components, and how to find design composition errors using model checking techniques. We illustrate our approach with a Web-based hypermedia case study since hypermedia documents and systems are now becoming complex software applications, which are component-based.