We describe an approach to introducing non-science majors to programming and computation in part by teaching them applets, servlets, and groupware applications. The course uses a dialect of didactic Scheme that is implemented in, and tightly integrated with, Java. The declarative nature of our approach allows non-science majors with no programming background to develop surprisingly complex web applications in about half a semester. This level of programming provides a context for a deeper understanding of computation than is usually feasible in a Computer Literacy course.

Haskell code is developed for two ways to list the strings of the language defined by a regular expression: directly by set operations and indirectly by converting to and simulating an equivalent automaton. The exercise illustrates techniques for dealing with infinite ordered domains and leads to an effective standard form for nondeterministic finite automata.

A reactive system can be specified by a labelled transition system, which indicates static structure, along with temporal-logic formulas, which assert dynamic behaviour. But refining the former while preserving the latter can be difficult, because:

(i) Labelled transition systems are ‘total’ – characterised up to bisimulation – meaning that no new transition structure can appear in a refinement.

(ii) Alternatively, a refinement criterion not based on bisimulation might generate a refined transition system that violates the temporal properties.

In response, Larsen and Thomson proposed modal transition systems, which are ‘partial’, and defined a refinement criterion that preserved formulas in Hennessy–Milner logic. We show that modal transition systems are, up to a saturation condition, exactly the mixed transition systems of Dams that meet a mix condition, and we extend such systems to non-flat state sets. We then solve a domain equation over the mixed powerdomain whose solution is a bifinite domain that is universal for all saturated modal transition systems and is itself fully abstract when considered as a modal transition system. We demonstrate that many frameworks of partial systems can be translated into the domain: partial Kripke structures, partial bisimulation structures, Kripke modal transition systems, and pointer-shape-analysis graphs.

We propose the design of a programming language for quantum computing. Traditionally, quantum algorithms are frequently expressed at the hardware level, for instance in terms of the quantum circuit model or quantum Turing machines. These approaches do not encourage structured programming or abstractions such as data types. In this paper, we describe the syntax and semantics of a simple quantum programming language with high-level features such as loops, recursive procedures, and structured data types. The language is functional in nature, statically typed, free of run-time errors, and has an interesting denotational semantics in terms of complete partial orders of superoperators.

A formulation of lattice theory as a system of rules added to sequent calculus is given. The analysis of proofs for the contraction-free calculus of classical predicate logic known as G3c extends to derivations with the mathematical rules of lattice theory. It is shown that minimal derivations of quantifier-free sequents enjoy a subterm property: all terms in such derivations are terms in the endsequent.

An alternative formulation of lattice theory as a system of rules in natural deduction style is given, both with explicit meet and join constructions and as a relational theory with existence axioms. A subterm property for the latter extends the standard decidable classes of quantificational formulas of pure predicate calculus to lattice theory.

A purely syntactic and untyped variant of Normalisation by Evaluation for the $\lambda$-calculus is presented in the framework of a two-level $\lambda$-calculus with rewrite rules to model the inverse of the evaluation functional. Among its operational properties there is a standardisation theorem that formally establishes the adequacy of implementation in functional programming languages. An example implementation in Haskell is provided. The relation to the usual type-directed Normalisation by Evaluation is highlighted, using a short analysis of $\eta$-expansion that leads to a perspicuous strong normalisation and confluence proof for $\beta\eta\!\up$-reduction as a byproduct.

Microsound is an emerging approach to music composition and analysis which places emphasis on extremely brief time-scales, usually a tenth of a second or less, as well as an integration of this micro-time level with the time-levels of sound gestures, sections, movements and whole pieces. This paper summarises some of the technical issues involved in microsonic analysis/composition, traces a history of microsonic techniques in contemporary music, and examines some of its aesthetic implications in a social context.

Various algorithmic techniques are available for generating music, many of which come from the field of artificial intelligence, which is rich with potential in this regard. However, the musical appropriateness of these techniques is less clearly understood. In this paper, I will report on a study that aimed to describe the characteristics of two of these techniques, rule-based and genetic algorithms, as they apply to melody generation. The appropriateness of these characteristics in contributing to well-formed melodies was judged by aesthetic criteria. The results indicate that most combinations of rules, mutations and evolutionary selection result in poor or average melodies, but that careful combination of these techniques can generate melodies that are not simply well-formed but in many cases display some elegance and novelty.

This paper introduces the concept of variable-coupled iterated map networks and explores its application to generation of musical textures. Such networks consist of one or more interlinked nodes. Each node consists of an iterated map function with a time-delay factor that schedules successive iterations. The value broadcast by a node can drive the variables and time-delay factor of any other nodes in the network, including itself. Lehmer's Linear Congruence Formula, an iterated map normally used for production of pseudo-random numbers, is explored for its own potential as a pattern generator and is used as the iterated map in the nodes in the examples presented. The capacity of these networks to produce richly gestural behaviours and mid-term modulation of behaviour is demonstrated.

The field of electroacoustic improvisation in the Netherlands is largely male dominated. Flutist, improviser and composer Anne La Berge signalled this and other problems related to gender in ‘Kraakgeluiden’, a Dutch venue for improvisation in electroacoustic music. Four possible factors contributing to gender discrimination are proposed: the stereotypical gendered concept of an improviser, differences in communicative styles, the dominance of male networks, and music technology itself. This is followed by a consideration of gendered differences in music improvisation. It is posited that male improvisers often seek to establish a hierarchy among themselves, while women performers tend to project themselves less to the forefront. Women improvisers may traditionally have a different sense of autonomy, in adherence to gender norms. While music education might offer a means to change behaviour patterns, it appears that these gender norms are internalised at a surprisingly young age. While concentrating on electroacoustic improvisation, this essay also includes relevant experiences of other improvisers. Gender discrimination in electroacoustic music improvisation is a complex issue deserving more research.

Absolute (or perfect) pitch exists in fewer than 1/10,000 of the adult population and many claim that it cannot be taught. On the other hand, research suggests that the mechanisms for absolute pitch exist in us all but access is inhibited during early maturation. We here argue that this inhibition can be switched off by artificially turning off part of the brain, allowing everyone access to absolute pitch. This possibility has profound implications for understanding the strategies adopted by the complex networks of the mind. We describe agent-based modelling techniques to understand the computational rationale for these inhibitory processes and to develop new artificial music recognition and synthesis techniques.

Atmospherics/Weather Works is an interdisciplinary project in the sonification of storms and other meteorological events generated directly from atmospheric data produced by a highly detailed and physically accurate simulation of weather systems. This paper discusses the background, conception and execution of the first stage of the project that has resulted in several performances, stereo recordings, a multi-channel spatialised sound installation, and an interactive sound environment.

Pattern theory provides a set of principles for constructing generative models of the information contained in natural signals, such as images or sound. Consequently, it also represents a useful language within which to develop generative systems of art. A pattern theory inspired framework and set of algorithms for interactive computer music composition are presented in the form of a self-organising hidden Markov model – a modular, graphical approach to the representation and spontaneous organisation of sound events in time and in parameter space. The result constitutes a system for composing stochastic music which incorporates creative and structural ideas such as uncertainty, variability, hierarchy and complexity, and which bears a strong relationship to realistic models of statistical physics or perceptual systems. The pattern theory approach to composition provides an elegant set of organisational principles for the production of sound by computer. Further, its machine learning underpinnings suggest many interesting applications to emergent tasks concerning the learning and creative modification of musical forms.

This paper focuses on the infrastructure and aesthetic approach used in PIWeCS: a Public Space Interactive Web-based Composition System. The concern was to increase the sense of dialogue between human and machine agency in an interactive work by adapting Paine's (2002) notion of a conversational model of interaction as a ‘complex system’. The machine implementation of PIWeCS is achieved through integrating intelligent agent programming with MAX/MSP. Human input is through a web infrastructure. The conversation is initiated and continued by participants through arrangements and composition based on short performed samples of traditional New Zealand Maori instruments. The system allows the extension of a composition through the electroacoustic manipulation of the source material.