Wendy MacCaull

Correspondence Results for Relational Proof Systems with Application to the Lambek Calculus

We present a general framework for proof systems for relational theories. We discuss principles of the construction of deduction rules and correspondences reflecting relationships between semantics of relational logics and the rules of the respective proof systems. We illustrate the methods developed in the paper with examples relevant for the Lambek calculus and some of its extensions.

DPF Workbench: A Diagrammatic Multi-Layer Domain Specific (Meta-)Modelling Environment

This paper presents the DPFWorkbench, a diagrammatic tool for domain specific modelling. The tool is an implementation of the basic ideas from the Diagram Predicate Framework (DPF), which provides a graph based formalisation of (meta)modelling and model transformations. The DPFWorkbench consists of a specification editor and a signature editor and offers fully diagrammatic specification of domain-specific modelling languages. The specification editor supports development of metamodelling hierarchies with an arbitrary number of metalevels; that is, each model can be used as a metamodel for the level below. The workbench also facilitates the automatic generation of domain-specific specification editors out of these metamodels. Furthermore, the conformance relations between adjacent metalevels are dynamically checked by the use of typing morphisms and constraint validators. The signature editor is a new component that extends the DPF Workbench with functionality for dynamic definition of predicates. The syntax of the predicates are defined by a shape graph and a graphical icon, and their semantics are defined by validators. Those predicates are used to add constrains on the underlying graph. The features of the DPF Workbench are illustrated by a running example presenting a metamodelling hierarchy for workflow modelling in the health care domain.

Compensable workflow nets

In recent years, Workflow Management Systems (WfMSs) have been studied and developed to provide automated support for defining and controlling various activities associated with business processes. The automated support reduces costs and overall execution time for business processes, by improving the robustness of the process and increasing productivity and quality of service. As business organizations continue to become more dependant on computarized systems, the demand for reliability has increased. The language t-calculus [8] was developed to aid in the creation and verification of compensable systems. Motivated by this we define Compensable WorkFlow nets (CWF-nets) and introduce a graphical modeling language Compensable Workflow Modeling Language (CWML). We present a case study, using CWML to model a real world scenario, translate the resulting CWF-net into DVE (the input language of the DiVinE model checker) and verify properties of interest.

A metamodelling approach to behavioural modelling

In this paper we propose a metamodelling approach to behavioural modelling. The approach combines diagrammatic modelling with formal foundations based on category theory and graph transformations. The static semantics of behavioural models is represented by instances of (meta)models, while their dynamic semantics is represented by transition systems. Transitions are described by coupled model transformations. To illustrate the approach, we present a running example of a workflow model for health services delivery.

Foundations of Health Information Engineering and Systems

This paper presents an overview of smart medication dispensing and administration devices and software tools designed to minimize dispensing and administration errors. Some of them are for users who take medications on a long term basis without close professional supervision; others are for pharmacy and nursing staffs in hospitals, long term care, and assisted living facilities. These tools should be configurable, customizable, easy to use and effective for diverse users and care-providing institutions. The paper describes approaches taken to meet these objectives.

Initial Work in the Design and Development of Verifiable Workflow Management Systems and Some Applications to Health Care

Workflows describe work processes as sequences of tasks and information regarding who performs them and their relative order. Workflows have been found useful to describe processes in a number of industries. This work focuses on workflows used in health care. Formal verification is the growing field of formalizing and verifying specifications for hardware and software systems. Many health care software systems are examples of safety critical systems and their proper function is required to protect the safety of the patients they manage. Formal verification can help assure this safety by checking workflows before they are put into action, where errors can potentially seriously affect patients. A language for expressing properties that need to be verified is developed and a model checker is implemented. The implementation of the model checker written in XSB Prolog is presented.

NOVA workflow: a workflow management tool targeting health services delivery

We present the NOVA Workflow tool-suite, a prototype for a process, information and communication management tool to guide and inform real world workflows with special attention to the needs of health services delivery. NOVA Workflow is an innovative workflow management system which integrates formal verification into the software development process. For workflow modeling the tool uses the time Compensable Workflow Modeling Language (CWMLT) which produces reliable and structured workflow models and enhances error handling. The graphical editor of the tool gives a common platform for modeling, verifying and developing software. The SOA based architecture of the workflow engine ensures compliance with industry standards. The tool includes an automated translator to a model checking tool, a monitor to facilitate run-time compliance of (health care) policy, and a user friendly browser to give clinicians a convenient way to view a patients information without losing the context. We propose an application of the browser to process diagnosis.

A Kripke semantics for the logic of Gelfand quantales

Gelfand quantales are complete unital quantales with an involution, *, satisfying the property that for any element a, if a ⊙ b ≤ a for all b, then a ⊙ a* ⊙ a = a. A Hilbert-style axiom system is given for a propositional logic, called Gelfand Logic, which is sound and complete with respect to Gelfand quantales. A Kripke semantics is presented for which the soundness and completeness of Gelfand logic is shown. The completeness theorem relies on a Stone style representation theorem for complete lattices. A Rasiowa/Sikorski style semantic tableau system is also presented with the property that if all branches of a tableau are closed, then the formula in question is a theorem of Gelfand Logic. An open branch in a completed tableaux guarantees the existence of an Kripke model in which the formula is not valid; hence it is not a theorem of Gelfand Logic.

An Efficient Explicit-time Description Method for Timed Model Checking

Timed modelchecking,the methodtoformallyverifyreal-timesystems, is attractingincreasingatten-tion from both the model checking community and the real-time community. Explicit-time descrip-tion methods verify real-time systems using general model constructs found in standard un-timedmodel checkers. Lamport proposed an explicit-time description method [17] using a clock-tickingprocess (Tick) to simulate the passage of time together with a group of global variables to model timerequirements. Two methods, the Sync-based Explicit-time Description Methodusing rendezvoussynchronization steps and the Semaphore-based Explicit-time Description Methodusing only oneglobal variable were proposed [27, 26]; they both achieve better modularity than Lamport’s methodin modelingthe real-time systems. In contrast to timed automatabased model checkerslike UPPAAL[7], explicit-time description methods can access and store the current time instant for future calcula-tions necessary for many real-time systems, especially those with pre-emptive scheduling. However,the Tick process in the above three methods increments the time by one unit in each tick; the statespaces therefore grow relatively fast as the time parameters increase, a problem when the system’stime period is relatively long. In this paper, we propose a more efficient method which enables theTick process to leap multiple time units in one tick. Preliminary experimentalresults in a high perfor-mance computing environment show that this new method significantly reduces the state space andimproves both the time and memory efficiency.

Topological representation of contact lattices

The theory of Boolean contact algebras has been used to represent a region based theory of space. Some of the primitives of Boolean algebras are not well motivated in that context. One possible generalization is to drop the notion of complement, thereby weakening the algebraic structure from Boolean algebra to distributive lattice. The main goal of this paper is to investigate the representation theory of that weaker notion, i.e., whether it is still possible to represent each abstract algebra by a substructure of the regular closed sets of a suitable topological space with the standard Whiteheadean contact relation.