Exact Bayesian curve fitting and signal segmentation.

We consider regression models where the underlying functional relationship between the response and the explanatory variable is modeled as independent linear regressions on disjoint segments. We present an algorithm for perfect simulation from the posterior distribution of such a model, even allowing for an unknown number of segments and an unknown model order for the linear regressions within each segment. The algorithm is simple, can scale well to large data sets, and avoids the problem of diagnosing convergence that is present with Monte Carlo Markov Chain (MCMC) approaches to this problem. We demonstrate our algorithm on standard denoising problems, on a piecewise constant AR model, and on a speech segmentation problem

Automatische Prozessmodellgenerierung mit Spearmint/EPG basierend auf dem Referenzmodell des ISO/IEC TR 15504 Standards

Wesentliche Komponenten bei Prozessverbesserungsprogrammen sind Prozessmodelle. Obwohl Assessments (beispielsweise gemäß dem Referenzmodell des ISO/IEC TR 15504) oft der Auslöser für Prozessverbesserungsprogramme sind, geht die in den Assessments gesammelte Information verloren und steht nicht mehr zur Erstellung von Prozessmodellen zur Verfügung. Dies hat im wesentlichen zwei Gründe: Zum einen gibt es generell kaum Werkzeugunterstützung bei der Durchführung von Assessments. Zum anderen fehlt die Möglichkeit, diejenigen Informationen die für die Assessments bereits erfasst wurden, konsistent zur Erstellung von Prozessmodellen zu verwenden. Der vorliegende Beitrag stellt einen integrierten Ansatz vor, der zum einen die Durchführung von Assessments unterstützt und zum anderen ermöglicht, die Ergebnisse des Assessment weiterhin zur Erstellung von Prozessmodellen mittels Prozessmodellierungswerkzeug zu nutzen

Learning and Understanding a Software Process through Simulation of its Underlying Model

This paper describes the usage of descriptive process modeling in the association with simulation for analyzing the dynamic effects of processes. At first a method to build a comprehensive descriptive model is presented, which can build the foundation for the simulation model. Based upon the understanding of the static process, parts of the dynamic model can be modeled can be created

Empirically driven design of software development processes for wireless internet services

The development of software for wireless services on the Internet is a challenging task due to the extreme time-to-market pressure, the newness of the application domain, and the quick evolution of the technical infrastructure. Nevertheless, developing software of a predetermined quality in a predictable fashion can only be achieved with systematic development processes and the use of engineering principles. Thus, systematic development processes for this domain are needed urgently. This article presents a method for the design of an adaptable software development process based on existing practices from re-lated domains, industrial piloting, and expert knowledge. First results of the application of the method for the wireless Internet services domain are described. The benefit for the reader is twofold: the article describes a validated method on how to gain process knowledge for an upcoming field fast and incrementally. Furthermore, first results of the process design for the wireless Internet services domain are given

Augmenting and assisting model elicitation tasks with 3D virtual world context metadata

Accurate process model elicitation continues to be a time consuming task, requiring skill on the part of the interviewer to extract explicit and tacit process information from the interviewee. Many errors occur in this elicitation stage that would be avoided by better activity recall, more consistent specification methods and greater engagement in the elicitation process by interviewees. Theories of situated cognition indicate that interactive 3D representations of real work environments engage and prime the cognitive state of the viewer. In this paper, our major contribution is to augment a previous process elicitation methodology with virtual world context metadata, drawn from a 3D simulation of the workplace. We present a conceptual and formal approach for representing this contextual metadata, integrated into a process similarity measure that provides hints for the business analyst to use in later modelling steps. Finally, we conclude with examples from two use cases to illustrate the potential abilities of this approach

Simulation-based risk reduction for planning inspections

Organizations that develop software have recognized that software process models are particularly useful for maintaining a high standard of quality. In the last decade, simulations of software processes were used in several settings and environments. This paper gives a short overview of the benefits of software process simulation and describes the development of a discrete-event model, a technique rarely used before in that field. The model introduced in this paper captures the behavior of a detailed code inspection process. It aims at reducing the risks inherent in implementing inspection processes and techniques in the overall development process. The determination of the underlying cause-effect relations using data mining techniques and empirical data is explained. Finally, the paper gives an outlook on our future work