Technical Issues in the Development of Knowledge-Based Services for the Semantic Web

The Semantic Web aims to extend the current Web with formal semantics in order to improve how users experience the Web, by ameliorating current activities and supporting the automation of some others. So far, current Semantic Web prototypes mostly aim at collecting and exposing information. Still, a semantic layer can support applying Knowledge-Based Systems techniques to the development of brand-new fully-fledged Knowledge-Based Services for the Web. In this paper, we present the technical issues that have to be faced in the development of such a kind of application by presenting the Online Design of Events Application: a Semantic Web-based design support system that assists event organisers in the process of preparing events such as workshops and conferences, by effectively reasoning over an inter-organisational process across the Web

Speeding up SOR Solvers for Constraint-based GUIs with a Warm-Start Strategy

Many computer programs have graphical user interfaces (GUIs), which need good layout to make efficient use of the available screen real estate. Most GUIs do not have a fixed layout, but are resizable and able to adapt themselves. Constraints are a powerful tool for specifying adaptable GUI layouts: they are used to specify a layout in a general form, and a constraint solver is used to find a satisfying concrete layout, e.g.\ for a specific GUI size. The constraint solver has to calculate a new layout every time a GUI is resized or changed, so it needs to be efficient to ensure a good user experience. One approach for constraint solvers is based on the Gauss-Seidel algorithm and successive over-relaxation (SOR). Our observation is that a solution after resizing or changing is similar in structure to a previous solution. Thus, our hypothesis is that we can increase the computational performance of an SOR-based constraint solver if we reuse the solution of a previous layout to warm-start the solving of a new layout. In this paper we report on experiments to test this hypothesis experimentally for three common use cases: big-step resizing, small-step resizing and constraint change. In our experiments, we measured the solving time for randomly generated GUI layout specifications of various sizes. For all three cases we found that the performance is improved if an existing solution is used as a starting solution for a new layout

Encapsulation and information hiding as the keys to maintainable and reusable hypermedia applications.

This paper presents a solution to the maintenance problem in hypermedia by applying object-oriented techniques to both the hypermedia data model and the hypermedia system's actual implementation. First, the primary concepts of the 'MESH' (Maintainable, End user friendly, Structured Hypermedia) approach are discussed briefly. These consist of a conceptual data model, a navigation paradigm and an implementation framework. Thereafter, it is shown how the object-oriented concepts of encapsulation and information hiding result in a hypermedia system consisting of self-contained, independently coded nodes. Intra node maintenance is separated entirely from inter node maintenance: the hyperbase's link structure can be updated without affecting node content, whereas an individual node's multimedia content can be reorganized without necessitating updates to links or link anchors.Applications; Information; Data; Model; Structure;

Digital Image Access & Retrieval

The 33th Annual Clinic on Library Applications of Data Processing, held at the University of Illinois at Urbana-Champaign in March of 1996, addressed the theme of "Digital Image Access & Retrieval." The papers from this conference cover a wide range of topics concerning digital imaging technology for visual resource collections. Papers covered three general areas: (1) systems, planning, and implementation; (2) automatic and semi-automatic indexing; and (3) preservation with the bulk of the conference focusing on indexing and retrieval.published or submitted for publicatio

Haptic-GeoZui3D: Exploring the Use of Haptics in AUV Path Planning

We have developed a desktop virtual reality system that we call Haptic-GeoZui3D, which brings together 3D user interaction and visualization to provide a compelling environment for AUV path planning. A key component in our system is the PHANTOM haptic device (SensAble Technologies, Inc.), which affords a sense of touch and force feedback – haptics – to provide cues and constraints to guide the user’s interaction. This paper describes our system, and how we use haptics to significantly augment our ability to lay out a vehicle path. We show how our system works well for quickly defining simple waypoint-towaypoint (e.g. transit) path segments, and illustrate how it could be used in specifying more complex, highly segmented (e.g. lawnmower survey) paths

A model-based approach to hypermedia design.

This paper introduces the MESH approach to hypermedia design, which combines established entity-relationship and object-oriented abstractions with proprietary concepts into a formal hypermedia data model. Uniform layout and link typing specifications can be attributed and inherited in a static node typing hierarchy, whereas both nodes and links can be submitted dynamically to multiple complementary classifications. In addition, the data model's support for a context-based navigation paradigm, as well as a platform-independent implementation framework, are briefly discussed.Data; Model; Specifications; Classification;