Timo Lehtonen

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This paper presents a method for managing and modeling a product family as a configurable product. The method enables efficient management of a large number of product variants. The modeling is based on a recently proposed conceptualization of configuration domain, which is a synthesis and extension of the main approaches to configuration. The concepts of(More)
Massive Open Online Courses (MOOCs) have rapidly become an important tool for educational institutes in teaching programming. Nevertheless, high drop-out rates have always been a problem in online learning. As MOOCs have become an important part of modern education, reducing the drop-out rate has become a more and more relevant research problem. This work(More)
An in vitro degradation study of three bioresorbable glass fiber-reinforced poly(l-lactide-co-dl-lactide) (PLDLA) composites was carried out in simulated body fluid (SBF), to simulate body conditions, and deionized water, to evaluate the nature of the degradation products. The changes in mechanical and chemical properties were systematically characterized(More)
This article describes the dissolution behavior of three silica-based resorbable glasses manufactured by an industrial-type continuous fiber drawing process yielding fibers with tensile strength of 1800-2300MPa. The results of a long-term in vitro degradation testing of the manufactured high strength bioresorbable glass fibers are presented. The degradation(More)
Modern software development approaches rely extensively on tools. Motivated by practices such as continuous integration, deployment and delivery, these tools are used in a fashion where data are automatically accumulated in different databases as a side-effect of everyday development activities. In this paper we introduce an approach for software(More)
Poly(L,DL-lactide) composites containing filler particles of bioactive glasses 45S5 and S53P4 were compared with a composite containing a slowly dissolving glass S68. The in vitro reactivity of the composites was studied in simulated body fluid, Tris-buffered solution, and phosphate buffered saline. The high processing temperature induced thermal(More)
Software projects have usually a lot of software engineering data available in different kinds of repositories. This data can be mined and used for software process improvement purposes. In general, agile methodologies emphasize reflection, making problems visible, and learning from the past. As the human mind is powerful in interpreting visual(More)
Traditionally, releasing new software has been a fragile and painful procedure. This view has been challenged by a new approach to software deployment, where the goal is to always be able to deploy the system. The transition from manual releases to instant deployments requires a high degree of automation. Furthermore, the transition requires a new mindset,(More)