Message sequence charts in the software engineering process

The software development process benefits from the use of Message Sequence Charts (MSC), which is a graphical language for displyaing the interaction behaviour of a system. We describe canonical applications of MSC independent of any software development methodology. We illustrate the use of MSC with a case study: the Meeting Scheduler

A taxonomy of sublinear multiple keyword pattern matching algorithms

AbstractThis article presents a taxonomy of sublinear keyword pattern matching algorithms related to the Boyer-Moore algorithm [3] and the Commentz-Walter algorithm [5, 6]. The taxonomy includes, amongst others, the multiple keyword generalization of the single keyword Boyer-Moore algorithm and an algorithm by Fan and Su [9, 10]. The corresponding precomputation algorithms are presented as well. The taxonomy is based on the idea of ordering algorithms according to their essential problem and algorithm details, and deriving all algorithms from a common starting point by successively adding these details in a correctness preserving way. This way of presentation not only provides a complete correctness argument of each algorithm, but also makes very clear what algorithms have in common (the details of their nearest common ancestor) and where they differ (the details added after their nearest common ancestor). Introduction of the notion of safe shift distances proves to be essential in the derivation and classification of the algorithms. Moreover, the article provides a common derivation for and a uniform presentation of the precomputation algorithms, not yet found in the literature

CWU Faculty Senate Minutes - 04/27/1994

These are the official Central Washington University Faculty Senate Minutes for the 04/27/1994 regular meeting

Specification of tools for message sequence charts

. The recent formalization of the semantics of Message Sequence Charts enables the derivation of tools for MSCs directly from this formal definition. We use the Asf+Sdf Meta-environment to make a straightforward implementation of tools for transformation, simulation and requirements testing. In this paper we present the complete specification of the tools. 1 Introduction Message Sequence Charts (MSCs) are a graphical method for the description of the interaction between system components [IT94]. Due to the recent formalization [MR94a, MR94b, IT95] of the semantics of Message Sequence Charts, we can consider MSC as a formal description technique. Currently, this formalization has already influenced the development of the language (in particular with respect to composition of MSCs, for which algebraic operators are considered) and it is expected to also influence the use of MSCs. Formalization will also have impact on the work of tool builders. The behavior of tools can be validated aga..

A programming-language extension for distributed real-time systems

In this paper we propose a method for extending programming languages that enables the specification of timing properties of systems. The way time is treated is not language specific and the extension can therefore be included in many existing programming languages. The presented method includes a view on the system development process. An essential feature is that it enables the construction of (hard) real-time programs that may be proven correct independently of the properties of the machines that are used for their execution. It therefore provides a similar abstraction from the execution platform as is normal for non-real-time languages. The aim of this paper is to illustrate the method and demonstrate its applicability to actual real-time problems. To this end we define a simple programming language that includes the timing extension. We present a formal semantics for a characteristic part of the language constructs and apply formal methods to prove the correctness of a small example program. We consider in detail a larger example, namely the mine-pump problem known from the literature. We construct a real-time program for this problem and describe various ways to map the program to an implementation for different platforms

The Data Distribution Service – The Communication Middleware Fabric for Scalable and Extensible Systems-of-Systems

During the past several decades techniques and technologies have emerged to design and implement distributed systems effectively. A remaining challenge, however, to devising techniques and technologies that will help design and implement SoSs. SoSs present some unique challenges when compared to traditional systems since their scale, heterogeneity, extensibility, and evolvability requirement