A language for information commerce processes

Automatizing information commerce requires languages to represent the typical information commerce processes. Existing languages and standards cover either only very specific types of business models or are too general to capture in a concise way the specific properties of information commerce processes. We introduce a language that is specifically designed for information commerce. It can be directly used for the implementation of the processes and communication required in information commerce. It allows to cover existing business models that are known either from standard proposals or existing information commerce applications on the Internet. The language has a concise logical semantics. In this paper we present the language concepts and an implementation architecture

Event composition model: achieving naturalness in runtime enforcement

Runtime enforcement techniques are introduced in the literature to cope with the failures that occur while software is being executed in its target environment. Runtime enforcement techniques contain various concepts that are composed with each other so that the overall functionality of the techniques is achieved. By the term concept we mean a fundamental abstraction or definition that exists in most runtime enforcement techniques. Since the development of runtime enforcement techniques can be complex, runtime enforcement frameworks are proposed to ease the development process. These frameworks offer specification languages to represent the concepts of interest.\ud To facilitate a natural representation of the concepts, this thesis introduces a computation model termed as Event Composition Model, which offers a set of novel linguistic abstractions, called events, event modules, reactors, reactor chains, event composition language and event constraint language. Events represent changes in the states of interest. Event modules are means to group events, have input-output interfaces, and implementations. Reactors are the implementations of event modules. Reactor chains are groups of related reactors that process events in a sequence. The event composition language facilitates selecting the events of interest; and the event constraint language facilitates defining constraints among reactors or event modules.\ud The thesis introduces the EventReactor language as an implementation of Event Composition Model. The language is open-ended for new sorts of events and reactor types. This helps to specify new sorts of concepts. It makes use of the Prolog language as its event composition language. Reactors and reactor chains are parameterizable, and are defined separately from event modules. This increases the reusability of event modules and their implementations. In the EventReactor language, the concepts of interest are represented independently from any programming language, and the compiler of EventReactor supports software developed in Java, C and .Net languages. For distributed software that makes use of Java-RMI as the middleware, the EventReactor language supports distribution-transparent representations of the concepts.\ud There are two basic ways in utilizing the EventReactor language: a) as an underlying language for the specification languages of runtime enforcement frameworks; b) as an implementation language for runtime enforcement techniques.\u

Learning morphological phenomena of Modern Greek an exploratory approach

This paper presents a computational model for the description of concatenative morphological phenomena of modern Greek (such as inflection, derivation and compounding) to allow learners, trainers and developers to explore linguistic processes through their own constructions in an interactive open‐ended multimedia environment. The proposed model introduces a new language metaphor, the ‘puzzle‐metaphor’ (similar to the existing ‘turtle‐metaphor’ for concepts from mathematics and physics), based on a visualized unification‐like mechanism for pattern matching. The computational implementation of the model can be used for creating environments for learning through design and learning by teaching

Extensible Host Language for Domain-Specific Languages

Programming languages greatly influence the way how programs are created and evolved. This means that the use of appropriate language for solved problem can greatly increase developer productivity. Composition of languages can provide great help in construction of a new language from existing components and for integration of several languages that may be needed to effectively solve a complex problem. In this paper we analyze the composition problem on the two levels: composition of languages and composition of concepts in a language. Possibilities of transition from language composition to concepts composition are also presented. Based on that, we propose a framework of languages construction based on concept composition that aims to support reusability of language elements and tools. It uses common host syntax for developed languages. Their semantics is defined in a general-purpose language. Proposed approach is demonstrated on example languages developed using prototype implementation

CSP design model and tool support

The CSP paradigm is known as a powerful concept for designing and analysing the architectural and behavioural parts of concurrent software. Although the theory of CSP is useful for mathematicians, the programming language occam has been derived from CSP that is useful for any engineering practice. Nowadays, the concept of occam/CSP can be used for almost every object-oriented programming language. This paper describes a tree-based description model and prototype tool that elevates the use of occam/CSP concepts at the design level and performs code generation to Java, C, C++, and machine-readable CSP for the level of implementation. The tree-based description model can be used to browse through the generated source code. The tool is a kind of browser that is able to assist modern workbenches (like Borland Builder, Microsoft Visual C++ and 20-SIM) with coding concurrency. The tool will guide the user through the design trajectory using support messages and several semantic and syntax rule checks. The machine-readable CSP can be read by FDR, enabling more advanced analysis on the design. Early experiments with the prototype tool show that the browser concept, combined with the tree-based description model, enables a user-friendly way to create a design using the CSP concepts and benefits. The design tool is available from our URL, http://www.rt.el.utwente.nl/javapp