A refinement framework to support validation and maintenance of knowledge-based systems

In this article, we argue that a refinement tool capable of assisting the maintainer of a Knowledge-Based System (KBS) with updating and upgrading of its knowledge base can substantially expand the scope of his activities and prolong the life of the system. We show that refinement tasks involved in KBS maintenance are similar to those taking place at the development stage, and thus a uniform refinement framework can be designed to support both activities. After defining refinement tasks expected to take place at different stages of a KBS's life cycle, we present a refinement framework capable of supporting them. It utilizes a small number of domain-independent heuristics to search for possible rule revisions which are expected to eliminate errors detected during KBS validation. An extended example is given to illustrate how different refinement tasks are carried out.     

Integrated assessment modelling for water resource allocation and management: A generalised conceptual framework

Nodal network approaches are a common framework for considering water allocation in river basins. In this type of model framework, a river basin is represented as a series of nodes, where nodes generally represent key points of extraction or instream use. When considering water allocation, agricultural production and other water use decisions generally interact with the stream system in two ways: they can affect the generation of runoff and thus the volume of water reaching the stream; or, they may involve direct extraction or use of water once it has reached the stream. Models are generally required to consider the influence of these decisions on flows and downstream water availability, as well as the influence of flows on the productive, passive use and environmental values of water. This paper provides a generalised conceptual framework for considering these types of interactions and their representation in integrated water allocation models. Applications of this framework to three very different case studies are outlined.     

VsLattice: A vector-based conceptual index structure for web service retrieval

With the rising adoption of web services, effective management of web services becomes a critical issue in making the paradigm of service-oriented computing more practical. In this paper, a novel structure, called Vector-based service Lattice ( VsLattice), is devised to index web services in a semantic way. Each web service is modeled as a group of Service Operation Vectors (SOVs) in the vector space, and each SOV represents an operation provided by the service. The web services, SOVs and the relationship between web services and SOVs form the Conceptual Indexing Context (CIC) of a given service collection. In the CIC, web services that provide similar operations (functions) are conceptually indexed by the same Operation Vector Concepts (OVCs). The underlying relationships among the OVCs are captured with the VsLattice, which is constructed by adopting the traditional concept lattice in a CIC. By taking advantage of the information obtained from the VsLattice, a new representation of SOV is devised. Based on this representation, a novel service retrieval model and the implemental system are developed to retrieve web services efficiently. The performance and retrieving quality of the proposed approach has been evaluated through a series of experiments.

A case study of a difficult refinement: a fast dictionary for a spell-checking program

We present a difficult refinement of a dictionary for a spell-checker. It represents a realistic problem and shows how a calculational approach using a relation known as a coupling invariant can improve the process of refinement over the conventional posit-and-prove approach. The paper concludes with a brief discussion of the advantages of the approach we adopt. We also hope that the paper will contribute a difficult refinement to the rather sparse corpus of such case studies in the literature—especially those using the calculational approach.     

A framework for measuring the performance of service supply chain management

Despite the increasing attention to the service supply chain management by both practitioners and academics, the performance measurement of service supply chains still remains unexplored. Most service firms realize that, in order to evolve an efficient and effective service supply chain, service supply chain management needs to be assessed for its performance. A literature review was conducted on performance measurement issues of service supply chains. This paper develops a framework of service supply chain performance measurement. Based on the strategic, tactical and operational level performance in a service supply chain, measures and metrics are discussed. The emphasis is on performance measures dealing with service supply chain processes such as demand management, customer relationship management, supplier relationship management, capacity and resource management, service performance, information and technology management and service supply chain finance. And to prioritize service supply chain performance measurement indicators to improve service supply chain performance, a methodology based on the extent fuzzy analytic hierarchy process is stressed. The developed framework of service supply chain performance measurement is applied to the hotel supply chain. The results of this study are useful both to practitioners in the service supply chain and to researchers carrying out further studies in the field.     

A geometric modelling framework for conceptual structural design from early digital architectural models

Computer support for conceptual structural design is still ineffective. This is due, in part, to the fact that current computer applications do not recognize that structural design and architectural design are highly interdependent processes, particularly at the early stages. The goal of this research is to assist structural engineers at the conceptual stage with early digital architectural models. This paper presents a geometric modeling framework for facilitating the engineers’ interactions with architectural models in order to detect potential structural problems, uncover opportunities, respect constraints, and ultimately synthesize structural solutions interactively with architectural models. It consists of a process model, a representation model and synthesis algorithms to assist the engineer on demand at different stages of the design process. The process model follows a top-down approach for design refinements. The representation model describes the structural system as a hierarchy of entities with architectural counterparts. The algorithms rely on geometric and topologic relationships between entities in the architectural model and a partial structural model to help advance the synthesis process. A prototype system called StAr (Structure-Architecture) implements this framework. A case study illustrates how the framework can be used to support the conceptual structural design process.     

Context modelling and a context-aware framework for pervasive service creation: A model-driven approach

Pervasive service creation entails a complex process that involves a diversity of development aspects. Context-awareness is an important facet of pervasive service creation, which deals with the acquisition, rendering, representation and utilisation of context information. In this paper we tackle context-awareness at the application level dealing with the representation and utilisation of context by services. We propose a model-driven approach that facilitates the creation of a context modelling framework and simplifies the design and implementation of pervasive services. To conclude, we demonstrate the benefits of our model-driven approach via the creation of a pervasive museum service and its evaluation using selected software metrics.     

Agent negotiation based ontology refinement process and mechanisms for service applications

Nowadays organisations are willing to outsource their business processes as services and make them accessible via the Web. In doing so, they can dynamically combine individual services to their service applications. However, unless the data on the Web can be meaningfully shared and is interpretable, this objective cannot be realised. In this paper, a new agent-based approach for managing ontology evolution in a Web services environment is exploited. The proposed approach has several key characteristics such as flexibility and extensibility that differentiate this research from others. The refinement mechanisms which cope with an evolving ontology are carefully examined. The novelty of our work is that inter-processes between different ontologies are studied from the agent’s perspective. Based on this perspective, an agent negotiation model is applied to reach an agreement regarding ontology discrepancy in an application. The efficiency and effectiveness of reaching an agreement over an ontology dispute is leveraged by the private negotiation strategy applied in the argumentation approach. An extended negotiation strategy is discussed to enable sufficient information in decision making at each negotiation round. A case study is presented to demonstrate ontology refinement in a Web services environment.     

Unification: A case-study in data refinement

In this paper, the Z notation is used to develop a small theory of terms and substitutions within which a simple unification algorithm can be specified and proved correct. Particular emphasis is placed on the use of Z's mathematical data types to simplify the development and structure of this theory. The correctness of an abstract version of the algorithm is proved first; this version operates on substitutions by composition. Then data refinement is used to show that the substitutions can be represented by binding functions that make composition a particularly efficient operation. The approach taken in this paper is compared with the approaches of three previous papers based on VDM.The contribution of this paper is to show how data refinement can be used to explain the design decisions behind a non-trivial program, and to provide a point of comparison between Z and VDM approaches to the same problem.     

Aligning goals and services through goal and business modelling

E-services are used as the cornerstones for modelling interaction points of cooperating IT systems, within and between enterprises. So far, research and development of e-services have mainly focused on an operational perspective, such as the development of standards for message exchanges and service coordination. However, on a strategic level, the success of e-services depends on their ability to work as a medium for the exchange of business values. In this paper, we present an approach that utilizes goal and business models as the foundation for designing e-services. The approach can be used to ensure that the developed e-services support the desired goals and business values of involved actors. A case study from the Swedish health care sector is used to ground and apply the presented approach.     

A framework for modelling multiple resource management issues—an open modelling approach

Our experience with development and distribution of environmental decision support systems (EDSSs) for delivering research outcomes to catchment managers has identified major impediments to their adoption. These include protracted development time, focus on single impacts, difficulty in combining results with other EDSSs, and no attention to socio-economic factors. Based on the premise that decision support tools can play a major role in the integration and adoption of research outcomes, we are developing a software tool for rapid building of EDSSs which can handle multiple issues across different scales. The prototype is called the Open Modelling Engine (OME). This paper describes the background to the development of the OME, its basic architecture, an OME-built EDSS for catchment nutrient management, and concludes with a discussion on research direction and opportunity.     

A robotic service framework supporting automated integration of ubiquitous sensors and devices

In recent years, due to the emergence of ubiquitous computing technology, a new class of networked robots called ubiquitous robots has been introduced. The Ubiquitous Robotic Companion (URC) is our conceptual vision of ubiquitous service robots that provides its user with the services the user needs, anytime and anywhere, in the ubiquitous computing environments. There are requirements to be met for the vision of URC. One of the essential requirements is that the robotic systems must support ubiquity of services. This means that a robot service must always be available even though there are changes in the service environment. More specifically, a robotic system needs to be interoperable with sensors and devices in its current service environments automatically, rather than statically pre-programmed for its environment. In this paper, the design and implementation of an infrastructure for URC called Ubiquitous Robotic Service Framework (URSF) is presented. URSF enables automated integration of networked robots in a ubiquitous computing environment by the use of Semantic Web Services Technologies.     

A conceptual framework for requirements engineering

A framework for assessing research and practice in requirements engineering is proposed. The framework is used to survey state of the art research contributions and practice. The framework considers a task activity view of requirements, and elaborates different views of requirements engineering (RE) depending on the starting point of a system development. Another perspective is to analyse RE from different conceptions of products and their properties. RE research is examined within this framework and then placed in the context of how it extends current system development methods and systems analysis techniques.     

A framework for automated and certified refinement steps

The refinement calculus provides a methodology for transforming an abstract specification into a concrete implementation, by following a succession of refinement rules. These rules have been mechanized in theorem provers, thus providing a formal and rigorous way to prove that a given program refines another one. In a previous work, we have extended this mechanization for object-oriented programs, where the memory is represented as a graph, and we have integrated our approach within the rCOS tool, a model-driven software development tool providing a refinement language. Hence, for any refinement step, the tool automatically generates the corresponding proof obligations and the user can manually discharge them, using a provided library of refinement lemmas. In this work, we propose an approach to automate the search of possible refinement rules from a program to another, using the rewriting tool Maude. Each refinement rule in Maude is associated with the corresponding lemma in Isabelle, thus allowing the tool to automatically generate the Isabelle proof when a refinement rule can be automatically found. The user can add a new refinement rule by providing the corresponding Maude rule and Isabelle lemma.