Program execution monitoring consists of checking whole executions for given properties, and collecting global run-time information. Monitoring gives valuable insights and helps programmers maintain their programs. However, application developers face the following dilemma: either they use existing monitoring tools which never exactly fit their needs, or they invest a lot of effort to implement relevant monitoring code. In this paper, we argue that when an event-oriented tracer exists, the compiler developers can enable the application developers to easily code their own monitors. We propose a high-level primitive called foldt which operates on execution traces. One of the key advantages of our approach is that it allows a clean separation of concerns; the definition of monitors is totally distinct from both the user source code and the language compiler. We give a number of applications of the use of foldt to define monitors for Mercury program executions: execution profiles, graphical abstract views, and two test coverage measurements. Each example is implemented by a few simple lines of Mercury.

Knowledge management has recently become the focus of public attention in business and engineering. Because knowledge acquisition is situated in the upstream of knowledge management, capturing knowledge is an important step for enterprises to achieve successful knowledge management. We focus on how engineers solve their design problems under given design contexts and propose a novel model and methods to capture knowledge from engineering design processes. Our goal is to acquire know-how knowledge without disrupting the normal design process. A three-layer design process model is introduced to represent generic design processes, and a grammar and extended dynamic programming (GEDP) method is developed based on the process model. GEDP adopts the grammar approach and EDP to automatically identify meaningful clusters, called operations, from primitive design events. Our approach is evaluated through a case study of designing a double-reduction gear system.

Product definition is widely accepted as one of the key factors to be considered in the early stage of product design and development. It has a direct impact on the success of a new product in the marketplace. Frequently, product definition is solicited through the voice of the customer (VoC). As such, an organization will obtain a prominent competitive edge over its competitors if it is able to effectively capture the genuine VoC or the requirements of a customer. Sorting techniques provide a means to elicit customer requirements. Although a number of sorting techniques were developed, few of them are able to handle the uncertainty and imprecision inherited from the VoC and subjective judgment because of their crisp decision making. An integrated approach is described, which is based on repeated single-criterion sorts and fuzzy evaluation, for the elicitation of customer requirements. The details of the integrated approach are presented. The approach is validated using a case study on the design of a wooden golf-club head. The details of the validation are discussed.

Under the concept of a global economy, enterprises are assigning design and production environments around the world in different areas. A serious issue of information exchange emerges as companies use traditional hardware and very distinct software appropriate to their field of expertise. To overcome the problem of low productivity due to the interruption of information, the concept of simultaneous engineering and concurrent design becomes very significant. In this article an agent-based ship design system is developed to support cooperation in distributed ship design environments. Above all, the conflicts that occur while sharing knowledge in the system must be resolved. One approach is to adopt a case-based conflict resolution strategy formulated to resolve current conflict on the basis of similar previously resolved cases in agent-based collaborative design system environments. To do this, conflict cases that occur in the initial ship design stage are extracted. On the basis of the extracted cases, a case base is constructed. In addition, a conflict resolution handler located in the superagent called a facilitator, an agent to control other subagents, is developed to treat conflict problems effectively by case-based reasoning. The case-based conflict resolution strategy is evaluated by applying it to a collaborative design process in the initial ship design stage, especially the machinery outfitting design, the preliminary design, the hullform design, and the structural design. Through the help of the collaboration of the design agents, the facilitator, the conflict resolution handler, and the case-based system, a designer can make decisions based on similar previously resolved cases.

The purpose of this short paper is to sketch the development of a few basic topics in the history of realizability. The number of topics is quite limited and reflects very much my own personal taste, prejudices and area of competence.

Realizability and related functional interpretations provide models for constructive mathematics. Generally, these models do not validate the axiom of choice for propositions taken over hierarchies of extensional functionals. We describe simple classes of models where the axiom is validated.

This special issue of Mathematical Structures in Computer Science contains the final Proceedings of the Tutorial Workshop on Realizability Semantics and Applications, which was held between June 30 and July 1, 1999 in Trento, Italy, as one of the satellite workshops associated to the Federated Logic Conference.

This work is a step toward the development of a logic for types and computation that includes not only the usual spaces of mathematics and constructions, but also spaces from logic and domain theory. Using realizability, we investigate a configuration of three toposes that we regard as describing a notion of relative computability. Attention is focussed on a certain local map of toposes, which we first study axiomatically, and then by deriving a modal calculus as its internal logic. The resulting framework is intended as a setting for the logical and categorical study of relative computability.

The notion of tripos (Hyland et al. 1980; Pitts 1981) was motivated by the desire to explain in what sense Higg's description of sheaf toposes as H-valued sets and Hyland's realizability toposes are instances of the same construction. The construction itself can be seen as the universal solution to the problem of realizing the predicates of a first order hyperdoctrine as subobjects in a logos with effective equivalence relations. In this note it is shown that the resulting logos is actually a topos if and only if the original hyperdoctrine satisfies a certain comprehension property. Triposes satisfy this property, but there are examples of non-triposes satisfying this form of comprehension.

In standard realizability one works with respect to an untyped universe of realizers called a partial combinatory algebra (pca). It is well known that a pca [Ascr] gives rise to a categorical model of impredicative type theory via the category Asm([Ascr]) of assemblies over [Ascr] or the realizability topos over [Ascr].

Recently, John Longley introduced a typed version of pca's (Longley 1999b). The above mentioned construction of categorical models extends to the typed case. However, in general these are no longer impredicative. We show that for a typed pca [Tscr] the ensuing models are impredicative if and only if [Tscr] has a universal type U. Such a type U can be endowed with the structure of an untyped pca such that U and [Tscr] induce equivalent realizability models: in other words, a typed pca [Tscr] with a universal type is essentially untyped. Thus, a posteriori it turns out that nothing is lost by restricting to (untyped) pca's as far as realizability models of impredicative type theories are concerned.

For instance, we show that for a typed pca [Tscr] the fibred category of discrete families in Asm([Tscr]) is small if and only if [Tscr] has a universal type. As the category of ¬¬-separated objects of the modified realizability topos is equivalent to Asm([Tscr]) for an appropriate typed pca [Tscr] without a universal type, it follows that the discrete families in the subcategory of ¬¬-separated objects of the modified realizability topos do not provide a model of polymorphic λ-calculus.

Earlier research on product family design (PFD) often highlights isolated and successful empirical studies with a limited attempt to explore the modeling and design support issues surrounding this economically important class of engineering design problems. This paper proposes a graph rewriting system to organize product family data according to the underpinning logic and to model product derivation mechanisms for PFD. It represents the structural and behavioral aspects of product families as family graphs and related graph operations, respectively. The derivation of product variants becomes a graph rewriting process, in which family graphs are transformed to variant graphs by applying appropriate graph rewriting rules. The system is developed in the language of programmed graph rewriting systems or PROGRES, which supports the specification of hierarchical graph schema and parametric rewriting rules. A meta model is defined for family graphs to factor out those entities common to all product families. A generic model is defined to describe all specific entities relevant to particular families. An instance model describes all product variants for individual customer orders. A prototype of a graph-based PFD system for office chairs is also developed. The system can provide an interactive environment for customers to make choices among product offerings. It also facilitates design automation of product families and enhances interactions and negotiations among sales, design, and manufacturing.

This issue of Organised Sound focuses on mapping in computer music. Unlike many issues of the journal, all articles in this edition are related to the theme. The call for contributions resulted in a significant collection of work which covered a broad range of activity in the field. This number of articles would normally fill more than one issue of the journal but we decided to keep the collection together as a representative body of work.

We were delighted to welcome Marcelo Wanderley as Guest Editor for this issue. I would like to thank him for his hard and diligent work throughout the preparation of this issue.

Mapping concerns the connection between gestures, or structures and audible results in a musical performance or composition. While this is of intense interest to performers of new instruments and instrument designers, it has also been an area of interest for some composers. Algorithmic composition is sometimes the process of imagining a gesture or structure - perhaps physical or visual - and then applying a mapping process to turn that ‘gesture’ of the conceptual domain into sound which may display the original conception in some way. This article looks at mapping from the point of view of algorithmic composition, particularly where persistence is an issue, such that the gesture (conceptual domain) is embodied and perceptible in the musical result.

This paper describes a trans-domain mapping (TDM) framework for translating meaningful activities from one creative domain onto another. The multi-disciplinary framework is designed to facilitate an intuitive and non-intrusive interactive multimedia performance interface that offers the users or performers real-time control of multimedia events using their physical movements. It is intended to be a highly dynamic real-time performance tool, sensing and tracking activities and changes, in order to provide interactive multimedia performances.

From a straightforward definition of the TDM framework, this paper reports several implementations and multi-disciplinary collaborative projects using the proposed framework, including a motion and colour-sensitive system, a sensor-based system for triggering musical events, and a distributed multimedia server for audio mapping of a real-time face tracker, and discusses different aspects of mapping strategies in their context.

Plausible future directions, developments and exploration with the proposed framework, including stage augmentation, virtual and augmented reality, which involve sensing and mapping of physical and non-physical changes onto multimedia control events, are discussed.

This paper considers the issues involved in the design of electronic and computer interfaces, specifically mapping - the designed link between an instrument's playing interface and its sound source. It defines the problem area, reviews the literature, and gives examples of specific system mappings. A general model is presented, with the aim of providing a framework for future discussions on what makes an effective mapping. Several guidelines for mapping strategies are given, based on existing work.

The vBow, a virtual violin bow musical controller, has been designed to provide the computer musician with most of the gestural freedom of a bow on a violin string. Four cable and servomotor systems allow for four degrees of freedom, including the lateral motion of a bow stroke across a string, the rotational motion of a bow crossing strings, the vertical motion of a bow approaching and pushing into a string, and the longitudinal motion of a bow travelling along the length of a string. Encoders, attached to the shaft of the servomotors, sense the gesture of the performer, through the rotation of the servomotor shafts, turned by the motion of the cables. The data from each encoder is mapped to a parameter in synthesis software of a bowed-string physical model. The software also sends control voltages to the servomotors, engaging them and the cables attached to them with a haptic feedback simulation of friction, vibration, detents and elasticity.

We define a two-axis transparency framework that can be used as a predictor of the expressivity of a musical device. One axis is the player's transparency scale, while the other is the audience's transparency scale. Through consideration of both traditional instruments and new technology-driven interfaces, we explore the role that metaphor plays in developing expressive devices. Metaphor depends on a literature, which forms the basis for making transparent device mappings. We examine four examples of systems that use metaphor: Iamascope, Sound Sculpting, MetaMuse and Glove-TalkII; and discuss implications on transparency and expressivity. We believe this theory provides a framework for design and evaluation of new human–machine and human–human interactions, including musical instruments.

The Metasaxophone is an acoustic tenor saxophone retrofitted with an onboard computer microprocessor and an array of sensors that convert performance data into MIDI control messages. The instrument has additionally been outfitted with a unique microphone system that allows for detailed control of the amplified sound. While maintaining full acoustic functionality it is also a versatile MIDI controller and an electric instrument. A primary motivation behind the Metasaxophone is to put signal processing under direct expressive control of the performer. Through the combination of gestural and audio performance control, employing both discrete and continuous multilayered mapping strategies, the Metasaxophone can be adapted for a wide range of musical purposes. This paper explores the artistic and technical development of the instrument, as well as new conceptions of musical mappings arising from the enhanced interface.

Software-based musical instruments have controls for input, a sound synthesizer for output, and mappings connecting the two. An effective layout of controls considers how many degrees of freedom each has, as well as the overhead of selecting each one while performing. An isolated mapping from one control to one synthesis parameter needs an appropriate choice of proportional, integral or derivative control (the control's value, or that value's rate of change, drives the synthesis parameter's value, or that value's rate of change). Beyond this, a compound mapping cross-coupling several controls and synthesis parameters can surprisingly increase the performer's intuitive understanding of the instrument.

This paper is about mapping strategies between gesture data and synthesis model parameters by means of perceptual spaces. We define three layers in the mapping chain: from gesture data to gesture perceptual space, from sound perceptual space to synthesis model parameters, and between the two perceptual spaces. This approach makes the implementation highly modular. Both perceptual spaces are developed and depicted with their features. To get a simple mapping between the gesture perceptual subspace and the sound perceptual subspace, we need to focus our attention on the two other mappings. We explain the mapping types: explicit/implicit, static/dynamic. We also present the technical and aesthetical limits introduced by mapping. Some practical examples are given of the use of perceptual spaces in experiments done at LMA in a musical context. Finally, we discuss several implications of the mapping strategies: the influence of chosen mapping limits onto performers' virtuosity, and the incidence of mapping on the learning process with virtual instruments and on improvisation possibilities.