Modeling of complex nonlinear dynamic systems using temporal convolution neural networks

An increasingly important class of nonlinear systems includes the nonaffine hybrid systems, in particular those in which the underlying dynamics explicitly depends on a switching signal. When the inherent complexity is treatable and the phenomena governing the system dynamics are known an implicit model can be derived to describe its behaviour over time. Conversely, when these assumptions are not met the system dynamics can still be approximated by regression-based techniques, provided a dataset comprising inputs and outputs collected from the system is available. One approach to deal with data driven modelling relies on computational intelligent frameworks, in which artificial neural networks stand out as a prominent class of universal approximation black box models. This work aims to explore 1D Convolutional Neural Networks capabilities, in which the inputs are represented by regressors and structural configuration parameters, to modelling nonlinear hybrid dynamic systems. Moreover, in order evaluate the intrinsic ability to transparently approximate hybrid dynamics, this deep neural network architecture is compared to a shallow multilayer layer perceptron framework, in which each structural configuration is independently approximated.Uma classe de sistemas não lineares que tem vindo a ganhar cada vez mais importância é a dos sistemas híbridos não-afins, em particular aqueles em que a dinâmica subjacente depende explicitamente de um sinal de comutação. Quando a complexidade inerente é tratável e os fenómenos que controlam a dinâmica do sistema são conhecidos, é possível obter-se um modelo implícito para descrever seu comportamento ao longo do tempo. Por outro lado, quando essas suposições não são cumpridas, a dinâmica do sistema pode ainda ser aproximada por técnicas baseadas em regressão, desde que um conjunto de dados contendo as entradas e as saídas do sistema esteja disponível. Uma abordagem para lidar com o problema de modelação experimental recorrendo a técnicas de inteligência computacional, na quais as redes neuronais artificiais se destacam como uma das classes proeminentes de aproximadores universais. Este trabalho tem como objetivo explorar as capacidades de redes neuronais convolutivas 1D, onde as entradas são representadas por regressores e parâmetros de configuração estrutural. Além disso, para avaliar a capacidade intrínseca para a aproximação de dinâmicas híbridas, esta arquitetura de rede neuronal profunda é comparada a uma estrutura neuronal proactivas multicamada, na qual cada configuração estrutural é independentemente aproximada

Prioritization of Software and System Requirements through Natural Language Processing for Testing Software

Tese de mestrado, Ciência de Dados, Universidade de Lisboa, Faculdade de Ciências, 2021Safety¬critical systems have been a constant and increased presence in industrial production, such as railways and vehicles. These systems are highly configurable and must be intensively tested by system engineers before being deliverable to customers. This process is highly time¬consuming and might require associations between the product features and requirements demanded by customers. Requirement prioritization looks to recognize the most relevant requirements of a system, aiming to reduce the costs and time of the testing process. Machine Learning has been shown useful in helping engineers in this task, automating associations between features and requirements. However, its application can be more difficult when requirements are written in natural language and if a ground truth dataset does not exist with them. In our work, we present ARRINA, a Natural Language Processing¬based recommendation system able to extract and associate components from safety¬critical systems with their specifications written in natural language and process customer requirements and map them to components. The system integrates a Weight Association Rule Mining framework to extract the components and their associations and generates visualizations that can help engineers understand which components are generally introduced in project requirements. The system also includes a recommendation framework that can associate in put requirements to existing subsystems, reducing engineers’ effort in terms of requirement analysis and prioritization. We performed several experiments to evaluate the different components of ARRINA over four railway’s subsystems and input requirements. As a result, the system achieved 90% of accuracy, which denotes its importance in reducing the time¬consuming of engineers in discovering the correct subsystem links and prioritizing requirements for the testing process

DERMATOSE FEBRIL – UM DIAGNÓSTICO A NÃO ESQUECER

A 46 year-old male patient with HIV-1/HCV coinfection and liver cirrhosis admitted with fever, prostration, and asthenia. On physical examination, scarce necrotic pustules on an erythematous base on the fingers and toes with swelling, pain and functional limitation of the left tibiotarsal joint were noted. Laboratory revealed only slight elevation of liver enzymology and CRP. We admitted the diagnostic hypotheses of endocarditis, meningococcemia or gonococcemia. After isolation of Neisseria gonorrhoeae from a blood culture, intravenous ceftriaxone was started with clinical improvement. Pharyngeal swab PCR positivity for N. gonorrhoeae confirmed the diagnosis of pharyngeal origin disseminated gonococcemia. Gonorrhea is a sexually transmitted infection caused by Gram-negative diplococcus Neisseria gonorrhoeae. Disseminated gonococcemia in the form of the classical "arthritis-dermatitis" syndrome accompanies only 1-2% of mucosal infections. Pharyngeal gonorrhea is often asymptomatic in men and women, probably constituting an important reservoir of the agent. The rise in gonorrhea incidence makes this case very pertinent in any dermatologist’s clinical practice today.Apresenta-se o caso de um doente de 46 anos, com coinfecção VIH-1/VHC e cirrose hepática, internado por febre, prostração e astenia. Ao exame objetivo, observavam-se escassas pústulas necróticas em base eritematosa acantonadas aos dedos das mãos e pés com edema, dor e limitação funcional dos mesmos e da articulação tíbio-társica esquerda. Analiticamente, apenas elevação ligeira da enzimologia hepática e da PCR. Admitiram-se as hipóteses diagnósticas de endocardite, meningococcémia ou gonococcémia. Após isolamento de Neisseria gonorrhoeae em hemocultura, iniciou-se ceftriaxone 1g/dia EV com melhoria clínica. A positividade da PCR para N. gonorrhoeae no exsudado orofaríngeo confirmou o diagnóstico de gonococcémia disseminada de ponto de partida orofaríngeo. A gonorreia é uma infeção sexualmente transmitida causada pelo diplococo Gram negativo Neisseria gonorrhoeae. A gonococcémia disseminada na forma da síndrome clássica “dermatite-artrite” acompanha apenas 1-2% das infeções mucosas. A gonorreia orofaríngea é geralmente assintomática em homens e mulheres, constituindo provavelmente um reservatório importante do agente. O aumento da incidência de gonorreia torna este caso pertinente na prática clínica actual do dermatologista

Core-TyCO, The Language Definition, Version 0.1

This is the second report on TyCO, a (still) experimental strongly and implicitly typed concurrent object oriented programming language based on a predicative polymorphic calculus of objects, featuring asynchronous messages, objects, and process declarations, together with a predicative polymorphic type syste

Affective responses to stretching exercises: Exploring the timing of assessments

Affective responses during exercise have been identified as a predictor of exercise adherence. However, research has been mostly limited to aerobic and resistance exercise. Considering that stretching activities are also an important component of physical fitness, this quasi-experimental study was designed to: 1) compare affective responses during and immediately after stretching exercises in apparently healthy adults, and 2) assess the consistency and repeatability of affect ratings obtained one week apart. For this purpose, we analyzed the Feeling Scale (FS) and Felt Arousal Scale (FAS) ratings using Time (during and after stretching) x Intensity (light, moderate, vigorous) x Stretched Muscle Group (quadriceps, hamstrings, glutes, latissimus dorsi, triceps) with repeated measures analysis of variance (ANCOVA) in 34 participants (21 males; aged 32.8 ± 8.6 years). The repeatability of FS and FAS ratings was assessed using two-way random-effects models, Intraclass Correlation Coefficients (ICC), and Bland-Altman plots. FS scores were higher following the stretching exercises, whereas FAS scores were lower, particularly in the vigorous intensity. In general, the inter-day repeatability for FS and FAS measurements was good across muscle groups. ICC tended to be higher at vigorous intensities. Ratings of core affect can be collected during static passive stretches using the FAS and FAS in ecologically valid settings. These results suggest that an adequate assessment of core affective responses to stretching activities should be performed during the exercises.info:eu-repo/semantics/publishedVersio

Oncological outcomes after endoscopic removal of malignant colorectal polyps

Objective: malignant colorectal polyp, defined by submucosally invasive adenocarcinoma, is the earliest form of clinically relevant colorectal cancer (CRC). After endoscopic resection additional surgery may be necessary, although decision criteria remain debatable. The objective of this study was to assess oncologic outcomes in terms of locoregional disease and to identify areas of improvement that may facilitate patients´ management.Methods: retrospective study of 40 patients with T1 CRC endoscopically resected between 2007 and 2012. Clinicopathological features were assessed and correlated with residual disease (RD), defined as presence of adenocarcinoma in intestinal wall and/ or lymph nodes.Results: thirty-one patients underwent surgery while 9 were followed-up. After surgery, RD was confirmed in 15 (48.4 %) patients: 8 (53.3 %) wall disease, 5 (33 %) nodal metastasis, and 2 (13.3 %) with both. No recurrence was detected in the follow-up group. The characteristics of the lesions that were associated with DR were sessile configuration (p = 0.03), the degree of differentiation G3 (p = 0.01) and intercepted/indeterminate margins (p = 0.01). Twenty-two patients were operated because of inadequate evaluation, mainly due to piecemeal resection, and half of them were disease free. Postoperative complications were found in 9 (30 %) patients, mainly anastomotic leakage that was associated with rectum anterior resection (p = 0.03).Conclusions: surgery should be considered in the presence of any risk factor for residual disease, while follow-up can be offered in low risk settings. Was also demonstrated a clear need for technical improvement in endoscopic resection and pathology evaluation in order to prevent unnecessary surgeries

Praxis and poiesis: from arts practice towards art theory

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Predictors of In-Hospital Mortality after Recovered Out-of-Hospital Cardiac Arrest in Patients with Proven Significant Coronary Artery Disease: A Retrospective Study

Introduction: Recovered Out-of-Hospital Cardiac Arrest (rOHCA) population is heterogenous. Few studies focused on outcomes in the rOHCA subgroup with proven significant coronary artery disease (SigCAD). We aimed to characterize this subgroup and study the determinants of in-hospital mortality. Methods: Retrospective study of consecutive rOHCA patients submitted to coronary angiography. Only patients with SigCAD were included. Results: 60 patients were studied, 85% were male, mean age was 62.6 ± 12.1 years. In-hospital mortality rate was 43.3%. Patients with diabetes and history of stroke were less likely to survive. Significant univariate predictors of in-hospital mortality were further analysed separately, according to whether they were present at hospital admission or developed during hospital evolution. At hospital admission, initial non-shockable rhythm, low-flow time>12min, pH4.75mmol/L were the most relevant predictors and therefore included in a score tested by Kaplan-Meyer. Patients who had 0/4 criteria had 100% chance of survival till hospital discharge, 1/4 had 77%, 2/4 had 50%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. During in-hospital evolution, a pH2mmol/L at 24h, anoxic brain injury and persistent hemodynamic instability proved significant. Patients who had 0/4 of these in-hospital criteria had 100% chance of survival till hospital discharge, 1/4 had 94%, 2/4 had 47%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. Contrarily, CAD severity and ventricular dysfunction didn't significantly correlate to the outcome. Conclusion: Classic prehospital variables retain their value in predicting mortality in the specific group of OHCA with SigCAD. In-hospital evolution variables proved to add value in mortality prediction. Combining these simple variables in risk scores might help refining prognostic prediction in these patients's subset.info:eu-repo/semantics/publishedVersio