State-of-the-art instance matching approaches do not perform well when used for matching instances across heterogeneous datasets. This shortcoming derives from their core operation depending on direct matching, which involves a direct comparison of instances in the source with instances in the target dataset. Direct matching is not suitable when the overlap between the datasets is small. Aiming at resolving this problem, we propose a new paradigm called class-based matching. Given a class of instances from the source dataset, called the class of interest, and a set of candidate matches retrieved from the target, class-based matching refines the candidates by filtering out those that do not belong to the class of interest. For this refinement, only data in the target is used, i.e., no direct comparison between source and target is involved. Based on extensive experiments using public benchmarks, we show our approach greatly improves the quality of state-of-the-art systems; especially on difficult matching tasks.

There have been several authoring methods proposed in the literature that are model based, essentially following the Model Driven Design philosophy. While useful, such methods need an effective way to allow the application designer to somehow synthesize the actual running application from the specification. In this paper, we describe HyperDe, an environment that combines Model Driven Design and Domain Specific Languages. We show the advantages of this combination to enable rapid authoring and prototyping of Web applications.

There have been several authoring methods proposed in the literature that are model based, essentially following the Model Driven Design philosophy. While useful, such methods need an effective way to allow the application designer to somehow synthesize the actual running application from the specification. In this paper, we describe HyperDE, an environment that combines Model Driven Design and Domain Specific Languages to enable rapid prototyping of Web applications.

This paper presents a search architecture that combines classical search techniques with spread activation techniques applied to a semantic model of a given domain. Given an ontology, weights are assigned to links based on certain properties of the ontology, so that they measure the strength of the relation. Spread activation techniques are used to find related concepts in the ontology given an initial set of concepts and corresponding initial activation values. These initial values are obtained from the results of classical search applied to the data associated with the concepts in the ontology. Two test cases were implemented, with very positive results. It was also observed that the proposed hybrid spread activation, combining the symbolic and the sub-symbolic approaches, achieved better results when compared to each of the approaches alone.

The goal of this paper is to argue the need to approach the personalization issues in Web applications from the very beginning in the application’s development cycle. Since personalization is a critical aspect in many popular domains such as e-commerce, it important enough that it should be dealt with through a design view, rather than only an implementation view (which discusses mechanisms, rather than design options). We present different scenarios of personalization covering most existing applications. Since our design approach is based on the Object-Oriented Hypermedia Design Method, we briefly introduce i the way in which we build Web application models as object -oriented views of conceptual models. We show how we specify personalized Web applications by refining views according to users’ profiles or preferences; we show that an object -oriented approach allows maximizing reuse in these specifications. We discuss some implementation aspects and compare our work with related approaches, and present some concluding remarks.

Designing high quality visual interfaces for hypermedia applications is difficult; it involves organizing different kinds of interface objects (for example those triggering navigation), prevent lhe user from cognitive overhead, etc. Unfortunately, interface design methods do not capture design decisions or rationale, so it is hard to record and convey interface design expertise.

We describe a setup using a surround screen environment (Extended Virtual Environment EVE dome) that we used to explore group interaction in real and virtual space. We have created a prototype framework to explore different modes of group interaction, the position and motion of users in real space are tracked using a vision-based interface that allows the activities of real crowds to be monitored. In the virtual space, we use a simple behavioural animation system that serves as a testbed to generate virtual group and crowd behaviour. Exploring different kinds of dynamic relationships between real and virtual groups gives insight to possible directions of group interaction.

In this paper we present a software engineering approach for building hypermedia applications. Our approach combines the use of an object-oriented method with a system of design patterns for navigational and interface design. We first present the core activities in the Object-Oriented Hypermedia Design Method (OOHDM), namely conceptual design navigation design, abstract interface design and implementation, describing the modeling constructs we use to build high-level, abstract navigational and interface structures. Next we give the rationale for using design patterns in the process of building high quality hypermedia applications, and present some simple patterns solving recurrent design problems. We finally discuss some further issues.

Hypertext development should benefit from a systematic, structured development, especially in the case of large and complex applications. A structured approach to hypertext development suggests the notion of authoring-in-the-large . Authoring-in-the-large allows the description of overall classes of information elements and navigational structures of complex applications without much concern with implementation details, and in a system-independent manner. The paper presents HDM (Hypertext Design Model), a first step towards defining a general purpose model for authoring-in-the-large. Some of the most innovative features of HDM are: the notion of perspective ; the identification of different categories of links (structural links, application links, and perspective links) with different representational roles; the distinction between hyperbase and access structures ; and the possibility of easily integrating the structure of a hypertext application with its browsing semantics. HDM can be used in different manners: as a modeling device or as an implementation device. As a modeling device, it supports producing high level specifications of existing or to-be-developed applications. As an implementation device, it is the basis for designing tools that directly support application development. One of the central advantages of HDM in the design and practical construction of hypertext applications is that the definition of a significant number of links can be derived automatically from a conceptual-design level description. Examples of usage of HDM are also included.

Abstract Hypertext development is still, for the most part, at the ‘handcrafting’ level, where each hypertext document must be hand‐designed. We present a compiler which takes hyperdocuments designed using a model‐based approach and generates stacks executable in Hyper Card. This compiler is implemented in standard SQL over a relational database representation of a hyperdocument designed using the hypermedia design model (HDM). The compiling approach, even though illustrated with HDM, can be used with any ‘structured’ design methodology.

It is becoming increasingly important that communication protocols be formally specified and verified. This paper describes a particular approach–the state transition model–using a collection of mechanically supported specification and verification tools incorporated in a running system called AFFIRM. Although developed for the specification of abstract data types and the verification of their properties, the formalism embodied in AFFIRM can also express the concepts underlying state transition machines. Such models easily express most of the events occurring in protocol systems, including those of the users, their agent processes, and the communication channels. The paper reviews the basic concepts of state transition models and the AFFIRM formalism and methodology and describes their union. A detailed example, the alternating bit protocol, illustrates varous properties of interest for specification and verification. Other examples explored using this formalism are briefly described and the accumulated experience is discussed.

This paper presents an exercise in the verification of a connection establishment protocol. A specification language named SPEX, tailored for the needs of communications protocols, is proposed, and its relation to a semi-automated verification system, AFFIRM, is discussed. This language is then used to specify a connection protocol currently being used. Certain errors are uncovered by analysis using the verification system. However, the major portion of the protocol's operation are shown to be correct.

Abstract This paper describes the Implementation model of a data definition facility for abstract data types, implemented as an extension to PL/1. The facility is based on a modified version of the cluster mechanism for the implementation of types. The proposed version tries to address the issues of efficiency and portability in connection with the goal of systematic programming.