521 research outputs found

    Approach to a theory of software process and software evolution

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    This preliminary introduction, extracted from work in progress, is intended to illustrate an approach currently under development. If successfully and convincingly completed, the result should make a significant contribution, providing software engineering technology with the theoretical foundations and framework needed to support further major process and technology improvement. Expressing the theory in an appropriate formalism will represent a still further advance. The present development is a first, essential, step to achieve this outcome

    FEAST/1 final report

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    The FEAST/1 project was conceived in 1994 following formulation of the hypothesis that the software evolution process is a feedback system and must be treated as such to achieve major process improvement. The overall goals of the project were to: provide objective evidence of the presence and impact of feedback and systems dynamics in the software process demonstrate that they can be exploited for managing and improving industrial processes produce justification for more substantial study of the feedback perspective and its implications This paper gives the specific objectives that were identified for the project and describes work carried out, difficulties encountered and results achieved

    Model-based assessment of software evolution processes

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    This paper argues that quantitative process models must be considered essential to support sustained improvement of E-type software evolution processes and summarises some of the experiences gained in the FEAST projects to date. Modelling guidelines are provided

    System dynamics modelling for the management of long term software evolution processes

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    An approach and basic concepts for the study of the system dynamics of long-term software evolution processes is presented. The approach provides a generic context and framework that supports at least three crucial process areas requiring management decision, resource allocation, release planning, and process performance monitoring. The report exemplifies the approach with an executable model. The latter reflects the global software process at a high level of abstraction and includes phenomenological observations derived from the laws of software evolution and the behaviours thereby implied. It incorporates concepts such as progressive (e.g., functional enhancement) and anti-regressive (e.g., complexity control) activities and enables the study of policies of human resource allocation to classes of activities. The example shows how the model permits assessment of the impact of alternative policies on various evolutionary attributes. It is part of and exemplifies the methods for software process modelling being developed and applied in the FEAST projects

    Assessing architectural evolution: A case study

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    This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles, and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand, to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach

    Onset of the Thermic Effect of Feeding (TEF): a randomized cross-over trial

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this investigation was to identify the onset of the thermic effect of feeding (TEF) after ingestion of a high carbohydrate (CHO) and a high protein (PRO) 1255 kJ (300 kcal) drink.</p> <p>Methods</p> <p>Resting metabolic rate (RMR) and TEF were measured over 30-minute periods via indirect calorimetry using a ventilated hood technique. Eighteen subjects (7 men and 11 women) completed two randomized, double-blind trials. Data were collected in 1-minute measurement intervals. RMR was subtracted from TEF and the time of onset was obtained when two consecutive data points exceeded 5% and 10% of resting metabolic rate.</p> <p>Results</p> <p>At 5% above RMR the onset of TEF for CHO was 8.4 ± 6.2 minutes and was not different as compared to PRO, 8.6 ± 5.2 minutes (p = 0.77). Likewise, no differences were found with a 10% increase above RMR: CHO, 14.1 ± 7.5 min; PRO, 16.7 ± 6.7 min (p = 0.36). Several subjects did not show a 10% increase within 30-min.</p> <p>Conclusion</p> <p>We conclude that the onset of TEF is variable among subjects but is initiated within about 5 to 20-min for most subjects after ingestion of a 1255 kJ liquid meal. No differences were found between CHO or PRO liquid meals.</p

    Software-Spezifikation durch halbformale, anschauliche Modelle

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    Der Beitrag erörtert die Frage, welche Ansätze zur Spezifikation grundsätzlich in Frage kommen, und begründet, warum in der industriellen Praxis das Prinzip der halbformalen Spezifikation auf der Basis anschaulicher Modelle vorteilhaft ist. Die Beispiele und die am Schluss wiedergegebenen Erfahrungen stammen aus unserer Arbeit mit dem Spezifikationssystem SPADES, das auf dem Prinzip der halbformalen Beschreibung beruht

    Unraveling the mysteries of dog evolution

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    The increased battery of molecular markers, derived from comparative genomics, is aiding our understanding of the genetics of domestication. The recent BMC Biology article pertaining to the evolution of small size in dogs is an example of how such methods can be used to study the origin and diversification of the domestic dog. We are still challenged, however, to appreciate the genetic mechanisms responsible for the phenotypic diversity seen in 'our best friend'
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