Implementing and Tuning an Autonomous Racing Car Testbed

Achieving safe autonomous driving is far from a vision at present days, with many examples like Uber, Google and the most famous of all Tesla, as they successfully deployed self driving cars around the world. Researchers and engineers have been putting tremendous efforts and will continue to do so in the following years into developing safe and precise control algorithms and technologies that will be included in future self driving cars. Besides these well known autonomous car deployments, some focus has also been put into autonomous racing competitions, for example the Roborace. The fact is that although significant progress that has been made, testing on real size cars in real environments requires immense financial support, making it impossible for many research groups to enter the game. Consequently, interesting alternatives appeared, such as the F1 Tenth, which challenges students, researchers and engineers to embrace in a low cost autonomous racing competition while developing control algorithms, that rely on sensors and strategies used in real life applications. This thesis focus on the comparison of different control algorithms and their effectiveness, that are present in a racing aspect of the F1 Tenth competition. In this thesis, efforts were put into developing a robotic autonomous car, relying on Robot Operative System, ROS, that not only meet the specifications from the F1 Tenth rules, but also allowed to establish a testbed for different future autonomous driving research.Obter uma condução autónoma segura está longe de uma visão dos dias de hoje, com exemplos como a Uber, Google e o mais famoso deles todos, a Tesla, que já foram globalmente introduzidos com sucesso. Investigadores e engenheiros têm colocado um empenho tremendo e vão continuar a fazê-lo nos próximos anos, a desenvolver algoritmos de controlo precisos e seguros, bem como tecnologias que serão colocados nos carros autónomos do futuro. Para além destes casos de sucesso bem conhecidos, algum foco tem sido colocado em competições de corridas de carros autónomos, como por exemplo o Roborace. O facto ´e que apesar do progresso significante que tem sido feito, fazer testes em carros reais em cenários verdadeiros, requer grande investimento financeiro, tornando impossível para muitos grupos de investigação investir na área. Consequentemente, apareceram alternativas relevantes, tal como o F1 Tenth, que desafia estudantes, investigadores e engenheiros a aderir a uma competição de baixos custos de corridas autónomas, enquanto desenvolvem algoritmos de controlo, que dependem de sensores e estratégias usadas em aplicações reais. Esta tese foca-se na comparação de diferentes algoritmos de controlo e na eficácia dos mesmos, que estão presentes num cenário de corrida da competição do F1 Tenth. Nesta tese, foram colocados muitos esforços para o desenvolvimento de um carro autónomo robótico, baseado em Robot Operative System, ROS, que não só vai de encontro `as especificações do F1 Tenth, mas que também permita estabelecer uma plataforma para futuras investigações de condução autónoma

Cognitive biases and audit professional skepticism : a sample from Portugal

Auditors must possess characteristics that allow them to achieve the level of professional skepticism required for the profession. Despite previous literature’s main emphasis on auditors’ traits and experience as the main factors influencing auditor’s level of professional skepticism, the relevance of cognitive biases effect on skepticism has grown increasingly in importance over the last decades with the emergence of behavioral finance. This dissertation aims to understand to what extent certain cognitive biases – outcome, confirmation, overconfidence and availability biases affect Portuguese auditors and whether these also have an effect on auditors’ level of professional skepticism. All the data collected refers to the year of 2022 and was obtained through a survey distributed to Portuguese auditors working in Big 4 audit firms (i.e., Deloitte, PWC, EY and KPMG). This dissertation confirms previous studies suggesting that auditors in higher hierarchical positions tend to have higher levels of professional skepticism and be less susceptible to cognitive biases. Furthermore, it concludes that cognitive biases, namely outcome, confirmation and overconfidence biases have an effect on the professional skepticism level of Portuguese auditors. Availability bias did not produce an effect on professional skepticism. Therefore, it is pivotal that these biases are taken into consideration by audit firms to address audit quality issues and keep up with increasingly higher standards.Os auditores devem possuir características que lhes permitam atingir o nível de ceticismo profissional exigido pela profissão. Apesar da literatura anterior enfatizar as características e a experiência dos auditores como os principais fatores que influenciam o nível de ceticismo profissional do auditor, a relevância do efeito dos enviesamentos cognitivos no ceticismo tem crescido cada vez mais nas últimas décadas com a introdução das finanças comportamentais. Esta dissertação tem como objetivo perceber em que medida certos enviesamentos cognitivos – enviesamento de resultados, de confirmação, de excesso de confiança e de disponibilidade afetam os auditores portugueses e se estes também afetam o nível de ceticismo profissional dos auditores. Todos os dados recolhidos referem-se ao ano de 2022 e foram obtidos através de um inquérito distribuído a auditores portugueses que trabalham em empresas de auditoria Big 4 (i.e., Deloitte, PWC, EY e KPMG). Esta dissertação confirma estudos anteriores que sugerem que auditores em posições hierárquicas mais altas tendem a ter níveis mais elevados de ceticismo profissional e são menos suscetíveis a enviesamentos cognitivos. Além disso, conclui que os enviesamentos cognitivos, nomeadamente enviesamentos de resultado, de confirmação e de excesso de confiança, têm efeito no cepticismo profissional dos auditores portugueses. O enviesamento de disponibilidade não produziu efeito sobre o ceticismo profissional. Por conseguinte, é fundamental que estes sejam tidos em consideração pelas empresas de auditoria de modo a combater problemas de qualidade e de forma a acompanhar padrões de exigência cada vez mais elevados

Cone Beam Computed Tomography Assessment of the Volume of Dental Tissue Removed During Endodontic Access

Introduction: The purpose of this study was to determine the volume of dental tissue removed during endodontic access preparation with cone-beam computed tomography (CBCT) comparing two different software. Methods and Materials: CBCT images of 20 teeth were obtained before and after endodontic access performed with spherical and conical diamond burs. The images were taken with i-CAT Precise system with 0.25 mm voxel size. Digital Imaging and Communications in Medicine (DICOM) images were loaded on two different software programs (Materialise® and InVersalius®), and a 3D reconstruction of the CBCT images was performed on both programs. The baseline volume (BV), and the final volume (FV) were obtained, and the lost tissue volume (LV) was calculated using the formula: LV=BV-FV. The t-test was used to compare initial and final volumes and also to compare the two programs, using a significance level of 5%. Results: The volumetric data calculated for the MaterialiseÒ and the InVesaliusÒ programs were, respectively: BV-mean of 441.79±85.08 mm3 and 442.01±84.83 mm3; FV-mean of 426.75±83.88 mm3 and 426.94±83.75 mm3; LV-mean of 15.04±4.32 mm3 and 15.07±4.16 mm3. No statistically significant difference was found in the volumes calculated by either program for initial, final, or removed tissue (P>0.05). However, there was a significant difference between the BV and LV calculated on the same program (P<0.05). Conclusion: Our in vitro study showed that CBCT was able to determine the volume of dental tissue removed in the endodontic access preparation of extracted human teeth, regardless of the software program used

Probable Person-to-Person Transmission of Legionnaires’ Disease

Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014

Gestão de risco e os impactos da instrução normativa CVM nº 550: análise empírica

The present study examines the effect of CVM normative instruction 550 on the use of derivatives and, consequently, on the risk management of Brazilian companies. The instruction requires companies to disclose the fair value of derivative instruments in their quarterly financial statements. However, this resolution does not establish on the accounting treatment for these types of instruments. Thus, it is supposed that the rule should affect both groups of derivatives users, hedgers (EH) and speculators (IS). The empirical results show that the risk the companies incur basically refers to the interest rate and exchange rate. After the adoption of the instruction, statistical evidence was found that shows a decrease in derivative use for both groups. The evidence suggests that instruction 550 has encouraged companies to use derivatives contracts with more prudence, which may suggest a change in risk management behavior. For this study, a sample of 107 Brazilian companies was used, belonging to 10 ICB economic sectors, during a ten-year period (1999 to 2009).Este trabalho analisa o efeito da instrução normativa CVM 550 sobre a utilização de derivativos e, consequentemente, a gestão de risco das companhias abertas brasileiras. A resolução exige que as empresas apurem por meio do valor de mercado os instrumentos derivativos em suas demonstrações financeiras trimestrais. No entanto, a deliberação não prevê tratamento contábil para tais tipos de instrumentos. Assim, é suposto que o efeito da norma deve afetar dois grupos de usuários de derivativos: os hedgers (EH) e os especuladores (IS). Os resultados empíricos mostram que o risco incorrido pelas empresas se refere, basicamente, à taxa de juros e câmbio. Após a adoção da norma, foram encontradas evidências estatísticas que apontam uma diminuição do uso de derivativos para ambos os grupos. As evidências sugerem que a resolução 550 tem incentivado as empresas a contratarem derivativos com mais prudência, o que indica uma mudança na política de gestão de risco. Para o estudo em questão foi utilizada uma amostra de 107 empresas brasileiras pertencentes aos 10 grandes setores econômicos do ICB, em uma janela de dados de 10 anos (1999 a 2009)

AN EXPERIMENTAL APPROACH TO CALIBRATE A FORCE-TORQUE SENSOR USING A NEURAL NETWORK

The force and torque sensor is a tool widely used in industrial processes and research centers where data need to be obtained with high accuracy. To use the sensor is needed a specific data acquisition board, as well as appropriate software. In addition, a specific calibration for different types of plates is required. This paper aims to calibrate a force and torque sensor, using neural networks in a universal manner, where the reproduction of the neural network for calibration of any sensor in other data acquisition boards is possible, apart from using a different software recommended by manufacturer. To perform the experiments, we used a sensor force and torque, Gamma model 3805 of ATI Industrial Automation, a data acquisition board (National Instruments myDAQ ©) and a pulley system for the distribution of weights between the axes of the sensor. To acquire the data we used the Labview software. For the modeling of neural network, we used a specific Matlab software toolbox. The experiment was conducted by placing loads with different values in known positions, so that the forces and torques along the three axes, have had predefined values. After this procedure was collected data voltage to the weights defined. These measures served to feed the neural network developed in Matlab. The partial results obtained were satisfactory and the neural network, tested with experimental data presented minimum values of mean and degree of accuracy close to one. Work is in progress and we intend to conduct a new experiment using the measurements of the sensor in the control loop of a robotic manipulator

Transtornos mentais comuns em Petrópolis-RJ: um desafio para a integração da saúde mental com a estratégia de saúde da família

OBJECTIVE: Common mental disorders are present in more than 50% of patients attending primary care clinics. The main objectives of this study were to detect whether there is any special group of patients within the Family Health Strategy that should be considered to be in greater risk for common mental disorders and to recommend alternative interventions to aid these patients. METHOD: In 2002, a cross-sectional study on common mental disorders seen at Family Health Strategy centers was conducted in Petrópolis, State of Rio de Janeiro. RESULTS: Common mental disorders were associated with women (OR = 2.90; 95% CI 1.82-4.32), younger than 45 years of age (OR = 1.43; 95% CI 1.02-2.01), with a monthly per capita family income of less than US$40.00 (OR = 1.68; 95$40,00 (OR = 1,68; 95% CI 1,20-2,39) e sem companheiro (OR = 1,71; 95% CI 1,22-2,39). Analfabetismo se associava a transtornos mentais comuns em pacientes que não eram extremamente pobres. Redes de suporte social, tais como frequentar regularmente a igreja (OR = 0,62; 95% CI 0,43-0,89), participar de atividades esportivas e artísticas (OR = 0,42; 95% CI 0,26-0,70) e ter pelo menos quatro amigos ou parentes em quem se podia confiar (OR = 0,53; 95% CI 0,31-0,91) estavam inversamente associadas a ter transtornos mentais comuns. DISCUSSÃO: Existe um grupo de risco especial para transtornos mentais comuns na atenção primária: mulheres, pobres, com pouco suporte social. Intervenções especiais para que sejam cuidadas na atenção primária têm sido desenvolvidas em outros países. CONCLUSÃO: Intervenções terapêuticas com comprovada evidência científica para apoiar essas mulheres a romper o círculo vicioso de pobreza e transtornos mentais podem ser inseridas nas ações de saúde mental.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade do Estado do Rio de Janeiro School of Medical ScienceUniversidade do Estado do Rio de Janeiro Institute of Social MedicinePublic Health National SchoolUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversity of London King's College Institute of PsychiatryUNIFESP, EPMSciEL

Effect of dental bleaching on pulp oxygen saturation in maxillary central incisors - a randomized clinical trial

Objective: To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching. Materials and Methods: 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - Inoffice bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student’s t-test (P<0.05). Results: Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05). Conclusions: Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching