17,381 research outputs found
Identifying Unmaintained Projects in GitHub
Background: Open source software has an increasing importance in modern
software development. However, there is also a growing concern on the
sustainability of such projects, which are usually managed by a small number of
developers, frequently working as volunteers. Aims: In this paper, we propose
an approach to identify GitHub projects that are not actively maintained. Our
goal is to alert users about the risks of using these projects and possibly
motivate other developers to assume the maintenance of the projects. Method: We
train machine learning models to identify unmaintained or sparsely maintained
projects, based on a set of features about project activity (commits, forks,
issues, etc). We empirically validate the model with the best performance with
the principal developers of 129 GitHub projects. Results: The proposed machine
learning approach has a precision of 80%, based on the feedback of real open
source developers; and a recall of 96%. We also show that our approach can be
used to assess the risks of projects becoming unmaintained. Conclusions: The
model proposed in this paper can be used by open source users and developers to
identify GitHub projects that are not actively maintained anymore.Comment: Accepted at 12th International Symposium on Empirical Software
Engineering and Measurement (ESEM), 10 pages, 201
Machinery for artificial emotions
We present a preliminary definition and theory of artificial emotion viewed as a sequential process comprising the appraisal of the agent global state, the generation of an emotion-signal, and an emotion-response. This theory distinguishes cognitive from affective appraisal on an architecture-grounded basis. Affective appraisal is performed by the affective component of the architecture; cognitive appraisal is performed by its cognitive component. A scheme for emotion classification with seven dimensions is presented. Among them, we emphasize the roles played by emotions and the way these roles are fulfilled. It is shown how emotions are generated, represented, and used in the Salt & Pepper architecture for autonomous agents (Botelho, 1997). Salt & Pepper is a specific architecture comprising an affective engine, a cognitive and behavioral engine, and an interruption manager. Most properties of the cognitive and behavioral engine rely upon a hybrid associative, schema-based long-term memory. In Salt & Pepper, emotion-signals, represented by label, object of appraisal, urgency, and valence, are generated by the affective engine through the appraisal of the agent's global state. For each emotion-signal there are several nodes stored and interconnected in long-term memory. Each of these nodes contains an emotion response that may be executed when an emotion-signal is generated. Emotion intensity relates to the activation of the node. It is shown that the Salt & Pepper architecture for autonomous agents exhibits several properties usually related to emotion: state and mood congruence, compound emotions, autonomic emotion-responses, and different emotion-responses to the same stimulus including the generation of different motives. The implementation of a concrete example is described.info:eu-repo/semantics/acceptedVersio
Low back pain in adolescents : identification of psychological risk factors. Epidemiological study in Great Lisbon area
FCT (Fundação para a Ciência e a Tecnologia), IDP (Instituto do Desporto de Portugal), AIESEP World Congres
Displacements of Slopes Under Earthquake Loading
The displacements and rates of displacement of slopes post-rupture are influenced by the dynamic response of soils. Pre-existing shear surfaces at or close to residual strength are frequently present in slopes of clay and weak mudstone, due to previous slope movement or tectonic disturbance. Knowledge of the strength of such surfaces under rapid loading is necessary of stability during and after an earthquake is to be examined. To obtain such data, high speed displacement controlled ring shear tests have been performed, on samples after being pre-sheared to residual conditions. With the results from those tests, suitable constitutive laws were derived for the soils and numerical analysis were made of an old landslide submitted to dynamic earthquake loading. Analysis were also performed for first landslides, on plastic clays, in order to calculate the maximum velocity, displacement and duration of sliding. The calculation is based on the assumption that the whole moving mass is displaced as a single rigid body with resistance mobilised along the sliding surface. Newmark\u27s sJjding block was used, sliding on a nonlinear surface involving a resistance dependent on factors such as displacement and rate of slip
Transthyretin familial amyloid polyneuropathy impact on health-related quality of life
info:eu-repo/semantics/publishedVersio
FasceÃte Necrotizante Causada por Photobacterium Damselae: o Primeiro Caso Descrito em Portugal
Necrotizing fasciitis is a severe soft tissue infection with a high mortality rate and therefore requires emergent surgical treatment. Several microorganisms can cause this infection, Photobacterium damselae being one of them, with only eight cases previously published in the literature. We report the first ever case of necrotizing fasciitis, caused by this microorganism, in Portugal. In this case report the patient survived after several debridement procedures and reconstruction of the upper limb with acellular dermal matrix and skin graft. A brief review of the Photobacterium damselae soft tissue infection reports as well as the clinical presentation, diagnosis, pathophysiology and treatment of necrotizing fasciitis can also be found in this paper.info:eu-repo/semantics/publishedVersio
EFFECTS OF STRAIN RATE AND TEMPERATURE ON THE MECHANICAL PROPERTIES OF GFRP COMPOSITES
In this work, the mechanical response of a composite material based on glass fibers embedded in an epoxy resin was experimentally studied as a function of strain rate and temperature. It was shown that for the temperature range from 23 to 100 °C the elastic properties of the composite are significant affected and the strain rate influences only the ultimate strength. The experimental research data and the approaches presented in this work should significantly extend our knowledge of the effect of elevated temperatures on the mechanical behavior of high temperature polymer matrix composites
- …