3,293 research outputs found
Robustness-Driven Resilience Evaluation of Self-Adaptive Software Systems
An increasingly important requirement for certain classes of software-intensive systems is the ability to self-adapt their structure and behavior at run-time when reacting to changes that may occur to the system, its environment, or its goals. A major challenge related to self-adaptive software systems is the ability to provide assurances of their resilience when facing changes. Since in these systems, the components that act as controllers of a target system incorporate highly complex software, there is the need to analyze the impact that controller failures might have on the services delivered by the system. In this paper, we present a novel approach for evaluating the resilience of self-adaptive software systems by applying robustness testing techniques to the controller to uncover failures that can affect system resilience. The approach for evaluating resilience, which is based on probabilistic model checking, quantifies the probability of satisfaction of system properties when the target system is subject to controller failures. The feasibility of the proposed approach is evaluated in the context of an industrial middleware system used to monitor and manage highly populated networks of devices, which was implemented using the Rainbow framework for architecture-based self-adaptation
Theoretical study of optical fiber Raman polarizers with counterpropagating beams
The theory of two counter-propagating polarized beams interacting in a
randomly birefringent fiber via the Kerr and Raman effects is developed and
applied to the quantitative description of Raman polarizers in the undepleted
regime. Here Raman polarizers, first reported by Martinelli et. al. [Opt.
Express. 17, 947 (2009)], are understood as Raman amplifiers operating in the
regime in which an initially weak unpolarized beam is converted into an
amplified fully polarized beam towards the fiber output. Three parameters are
selected for the characterization of a Raman polarizer: the degree of
polarization of the outcoming beam, its state of polarization, and its gain.
All of these parameters represent quantities that are averaged over all random
polarization states of the initially unpolarized signal beam. The presented
theory is computer friendly and applicable to virtually all practically
relevant situations, including the case of co-propagating beams, and in
particular to the undepleted as well as the depleted regimes of the Raman
polarizer.Comment: 16 pages, 5 figures, to be submitted to the Journal of Lightwave
Technolog
Numerical simulation of the tension–compression behavior of tie connections in brick masonry walls
Brick masonry veneer walls connected to infill walls inserted in a reinforced concrete (RC) frame are a common constructive system in Portugal. The stability of the veneer wall is ensured by ties that make the connection with the masonry infill walls. These ties enable the transferring of out-of-plane loads to the main structure due to wind, and particularly due to earthquakes. However, the characterization of the seismic behavior of these tie connections is an insufficiently explored topic. The present paper shows a numerical investigation that aims to simulate experimental results of tension and compression tests performed on masonry prisms connected by means of steel ties. The main objective of the present research is to obtain a better understanding of the complex structural behavior of this specific construction system to then develop simplified numerical tools to be used in engineering practice for the seismic design and retrofitting of brick masonry veneer walls. The numerical results match well the experimental ones, and the validated approach can be used in the future to carry out parametric analyses to evaluate the influence of material and geometric properties of the tie and masonry, as well as the type of action and construction details.Portuguese Foundation for Science and Technology (FCT), through the financing of the research project SEVen—Development of Sustainable Ceramic Brick Masonry Veneer Walls for Building Envelops (PTDC/ECI-CON/30876/2017)
The effect of the interproximal creeping attachment with VISTA technique in the anterior mandible: a case report with a 4 years follow up
info:eu-repo/semantics/publishedVersio
Dentists’ perceptions and usability testing of the Implant Disease Risk Assessment IDRA, a tool for preventing peri-implant disease: a qualitative study
Introduction: we aimed to explore dentists’ perceptions toward the implementation of a dental informatics risk assessment tool which estimates the risk for a patient to develop peri-implantitis. Materials and Methods: the Implant Disease Risk Assessment Tool (IDRA) was presented to a convenience sample of seven dentists working in a university clinic, whom were asked to use IDRA with the information of three clinical cases whilst thinking aloud and then fill the System Usability Scale (SUS). A semi-structured interview technique was used with audio record to allow free expression of participants’ perceptions related to the IDRA. The interviews information was categorized and analyzed by the authors. Results: to our knowledge, this is the first study conducted to develop a qualitative usability test of IDRA, evaluating the effectiveness, efficiency, and users’ satisfaction. There were more variations in responses the greater the degree of complexity of the clinical case. Generally, the participants classified the tool as good, getting usability values of 77,2 (SD 19,8) and learnability 73,2 (SD 24,5). Conclusion: four additional factors should be considered to improve IDRA tool: 1) considering the relation between contour angle and peri‐implant tissue height; 2) automatic periodontal classification in the IDRA tool after completing the periodontogram in the clinical software; 3) presentation of a flow chart to assist therapeutic decisions alongside the final score defined by the IDRA tool; 4) integrating of precision tests such as Implantsafe® DR (dentognostics gmbh, Jena) and Oralyzer®(dentognostics gmbh, Jena). Clinical Significance: etiology and pathogenesis of peri-implant diseases is multifactorial. These tools must follow a natural integration to be easily applied in a clinical setting. It is important to study their usability from the clinicians’ point of view, evaluating the effectiveness, efficiency, and users’ satisfaction.info:eu-repo/semantics/acceptedVersio
Peri-implant diseases diagnosis, prognosis and dental implant monitoring: a narrative review of novel strategies and clinical impact
BACKGROUND: The diagnosis of peri-implantar and periodontal relies mainly on a set of clinical measures and the evaluation of radiographic images. However, these clinical settings alone are not sufficient to determine, much less predict, periimplant bone loss or future implant failure. Early diagnosis of periimplant diseases and its rate of progress may be possible through biomarkers assessment. Once identified, biomarkers of peri-implant and periodontal tissue destruction may alert the clinicians before clinical signs show up. Therefore, it is important to consider developing chair-side diagnostic tests with specificity for a particular biomarker, indicating the current activity of the disease. METHODS: A search strategy was created at Pubmed and Web of Science to answer the question: "How the molecular point-of-care tests currently available can help in the early detection of peri-implant diseases and throws light on improvements in point of care diagnostics devices?". RESULTS: The PerioSafe® PRO DRS (dentognostics GmbH, Jena) and ImplantSafe® DR (dentognostics GmbH, Jena ORALyzer® test kits, already used clinically, can be a helpful adjunct tool in enhancing the diagnosis and prognosis of periodontal/peri-implantar diseases. With the advances of sensor technology, the biosensors can perform daily monitoring of dental implants or periodontal diseases, making contributions to personal healthcare and improve the current status quo of health management and human health. CONCLUSIONS: Based on the findings, more emphasis is given to the role of biomarkers in diagnosing and monitoring periodontal and peri-implant diseases. By combining these strategies with traditional protocols, professionals could increase the accuracy of early detection of peri-implant and periodontal diseases, predicting disease progression, and monitoring of treatment outcomes.info:eu-repo/semantics/publishedVersio
The effect of the interproximal creeping attachment with VISTA technique in the anterior mandible: a case report with a 4 years follow up
info:eu-repo/semantics/publishedVersio
External match load in amateur soccer: the influence of match location and championship phase
Assessment of the physical dimension implicit in the soccer match is crucial for the improvement and individualization of training load management. This study aims to: (a) describe the external match load at the amateur level, (b) analyze the differences between playing positions, (c) verify whether the home/away matches and if (d) the phase (first or second) of the championship influence the external load. Twenty amateur soccer players (21.5 ± 1.9 years) were monitored using the global positioning system. The external load was assessed in 23 matches, where 13 were part of the first phase of the competition (seven home and six away matches) and the other 10 matches belonged to the second (and final) phase of the championship (five home and five away matches). A total of 173 individual match observations were analyzed. The results showed significant differences between playing positions for all the external load measures (p < 0.001). There were higher values observed in the total distance covered for central defenders (p = 0.037; ES = 0.70) and in high-intensity decelerations for forwards (p = 0.022; ES = 1.77) in home matches than in away matches. There were higher values observed in the total distance (p = 0.026; ES = 0.76), relative distance (p = 0.016; ES = 0.85), and moderate-intensity accelerations (p = 0.008; ES = 0.93) for central defenders, in very high-speed running distance for forwards (p = 0.011; ES = 1.97), and in high-intensity accelerations (p = 0.036; ES = 0.89) and moderate-intensity decelerations (p = 0.006; ES = 1.11) for wide midfielders in the first phase than in the second phase of the championship. Match location and championship phase do not appear to be major contributing factors to influence the external load while the playing position should be used as the major reference for planning the external training load.info:eu-repo/semantics/publishedVersio
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