22030322
Animation of Object-Z specifications using a Z animator
We discuss a methodology for animating the Object-Z specification language using a Z animation environment. Central to the process is the introduction of a framework to handle dynamic instantiation of objects and management of object references. Particular focus is placed upon building the animation environment through pre-existing tools, and a case study is presented that implements the proposed framework using a shallow encoding in the Possum Z animator. The animation of Object-Z using Z is both automated and made transparent to the user through the use of a software tool named O-zone.
594379
Extending W for Object-Z
This paper presents a logic for Object-Z which extends W, the logic for Z adopted as the basis of the deductive system in the Z Base Standard. The logic provides a basis on which tool support for reasoning about Object-Z specifications can be developed. It also formalises the intended meaning of Object-Z constructs and hence provides an abstract, axiomatic semantics of the language.
8767817
Incremental Development of Real-Time Requirements: The Light Control Case Study
System requirements frequently change while the system is still under development. Usually this means going back and revising the requirements specification and redoing those development steps already completed. In this article we show how formal requirements can be allowed to evolve while system development is in progress, without the need for costly redevelopment. This is done via a formalism which allows requirements engineering steps to be interleaved with formal development steps in a manageable way. The approach is demonstrated by a significant case study, the Light Control System.
671422
Specifying Mode Requirements of Embedded Systems
This paper presents a formal notation for specifying requirements of embedded systems which exhibit continuous, real-time behaviour and move through various modes under digital control. It does this by extending an existing formal notation supporting continuous, real-time behaviour with an explicit concept of modes. The resulting notation avoids the subtleties which would otherwise arise when specifying mode-related requirements. It is therefore ideal as a means of specifying and communicating requirements of embedded systems.
18204246
Model checking Object-Z classes: Some experiments with FDR
This paper investigates model checking Object-Z classes via their translation to the input notation of the CSP model checker FDR. Such a translation must not only be concerned with preserving the semantics of the original specification, but also with how efficiently the resulting specification can be model checked. Hence, the paper investigates alternative translation schemes and compares how efficiently the resulting specifications can be checked.
30219210
Compositional Class Refinement in Object-Z
Object-Z allows coupling constraints between classes which, on the one hand, facilitate specification at a high level of abstraction, but, on the other hand, make class refinement non-compositional. The consequence of this is that refinement is not practical for large systems. This paper overcomes this limitation by introducing a methodology for compositional class refinement in Object-Z. The key step is an equivalence transformation of an arbitrary Object-Z specification to one in which introduced constraints prohibit non-compositional refinements. The methodology also allows the constraints which couple classes to be refined yielding an unrestricted approach to compositional class refinement.
206854015
Fitness Distance Correlation and Ridge Functions
Fitness Distance Correlation has been proposed as a measure of function optimization difficulty. This paper describes a class of functions, named the Ridge Functions which, according to the measure, should be highly misleading. However, all functions tested were optimized easily by both a GA and a simple hill climbing algorithm. Scatter graph analysis of Ridge functions gave little guidance due to the large number of functions with an identical scatter graph, the majority of which are not in the class of Ridge functions and are not simple to optimize.
41530585
Computer Games Have Words, Too: Dialogue Conventions in Final Fantasy VII
1479807
The large-display user experience
The PC's increasing graphical-processing power is fueling a demand for larger and more capable display devices. Several operating systems have supported work with multiple displays for some time. This fact, coupled with graphic-card advancements has led to an increase in multiple monitor (multimon) use. Large displays offer users significant benefits and usability challenges. In this article the authors discuss those challenges along with novel techniques to address these issues.