Browsing by Issue Date, starting with "2018-06"
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- UAV Proposal for Real-Time Online Gaming to Reduce StressPublication . Safadinho, David; Ramos, João; Ribeiro, Roberto; Pereira, António Manuel de JesusSports practice is a common way people find to relieve the high stress levels. Sometimes it is impossible to move around and look for a place to do that, but the new technologies allow the practice of sports and recreational activities afar through the internet, in a comfortable way. The technological progress is responsible for the virtualization of many tasks. Nowadays, online multiplayer games try to be real, but they only focus on scenery virtualizations. As we know there already exists various UAV competitions, but sometimes, due to the many rules imposed by the aerial space, it isn't possible and safe to train when and where we want. To promote a better quality of life, it is being developed a platform with a totally distributed architecture based on the Internet of Drones concept, as it is shown in this article, that will allow the control of real unmanned aerial vehicles at anytime, from anywhere. The solution is composed by a high-scalability and a low-cost modeling system that will permit UAV users to practice their control skills in a comfortable and safe way. This interaction with a real vehicle will relieve the high stress levels caused by daily life.
- Immediate effects of acupuncture on the mechanosensitivity of the median nerve: an exploratory randomised trialPublication . Morais, Nuno; Greten, Henry Johannes; Santos, Maria João; Machado, Jorge PereiraAcupuncture appears to reduce the mechanosensitivity of peripheral nerves in animal models; yet, this possibility has not been demonstrated in humans.The main purpose of this exploratory trial was to evaluate the immediate effects of acupuncture on the mechanosensitivity of the median nerve, measured by the elbow extension range-of-motion (EE–ROM) at pain onset and maximum tolerance during the upper limb neurodynamic test 1 (ULNT1). Additional purposes were to test the effects of two different points in ULNT1 responses and critically appraise pre-/post-intervention changes for conducting future research.
- Reproductive trade-offs in a temperate reef fish under high pCO2 levelsPublication . Faria, A. M.; Lopes, A. F.; Silva, C. S. E.; Novais, S. C.; Lemos, M. F. L.; Gonçalves, E. J.Fishes are currently facing novel types of anthropogenic stressors that have never experienced in their evolutionary history, such as ocean acidification. Under these stressful conditions, energetically costly processes, such as reproduction, may be sacrificed for increased chances of survival. This trade-off does not only affect the organism itself but may result in reduced offspring fitness. In the present study, the effects of exposure to high pCO2 levels were tested on the reproductive performance of a temperate species, the two-spotted goby, Gobiusculus flavescens. Breeding pairs were kept under control (∼600 μatm, pH∼ 8.05) and high pCO2 levels (∼2300 μatm, pH∼ 7.60) conditions for a 4-month period. Additionally, oxidative stress and energy metabolism-related biomarkers were measured. Results suggest that reproductive activity is stimulated under high pCO2 levels. Parental pairs in the simulated ocean acidification conditions exhibited increased reproductive output, with 50% more clutches and 44% more eggs per clutch than pairs under control conditions. However, there was an apparent trade-off between offspring number and size, as larvae of parental pairs under high pCO2 levels hatched significantly smaller, suggesting differences in parental provisioning, which could be related to the fact that these females produce more eggs. Moreover, results support the hypothesis of different energy allocation strategies used by females under high pCO2 conditions. These changes might, ultimately, affect individual fitness and population replenishment.
- Pathways of adult student-workers in higher education: explaining the risks of early dropout, late dropout and graduationPublication . Carreira, Pedro; Lopes, Ana SofiaIn Portugal, student-workers represent 8.5% of higher education students. They are mainly adults with a less favourable socioeconomic and professional background that return to school while working and after experiencing some years in the labour market so as to find a new profession or a job promotion. However, due to their particular characteristics and time restrictions, adult student-workers observe high dropout rates, justifying the need of identifying their determinants of dropout and graduation risks in a separate way. With this purpose, we match five sources to obtain a unique five-year longitudinal dataset with extensive information on individual, degree and employment variables of 976 student-workers from Leiria Polytechnic Institute, Portugal. We then use event history analysis, with competing risks, to investigate if and when the event of dropping out or graduation occurs and how a set of covariates affects the risk of each event. In addition, we distinguish between those that drop out with few accumulated credits (labelled as early dropouts) and those that drop out despite having a significant number of credits completed (late dropouts). We found that early dropouts depend more on academic failure, school-residence distance, personal motivation and employment variables, while late dropouts are more influenced by other factors such as marital status and degree characteristics. Among policy recommendations, beyond the frequently referred actions to reduce academic failure, we highlight the adoption of measures to avoid stopout behaviour, the adequate definition of the schedule and composition of classes (daytime classes and higher proportions of student-workers in the classroom, and with distinct academic performance, seem to reduce dropout risk), and the curriculum appreciation at the admission moment (some employment variables seem to contribute to increase the probability of graduation while others seem to contribute to enhance the risk of dropout), including criteria for regional preference and personal motivation.
- A gastronomia e a criatividade como fatores de atração turística - Estudo de caso: ÓbidosPublication . Oliveira, SimãoAtualmente, a oferta turística enfrenta um desafio cada vez mais significativo, relacionado com a evolução dos gostos, interesses e motivações dos turistas. Se até há alguns anos atrás muitos destinos turísticos mantinham uma oferta padronizada, hoje em dia, com o advento do turismo de nichos e com a cada vez maior competitividade, é fulcral que a oferta de um destino seja criativa, multifacetada, procurando todavia manter a sua identidade. A gastronomia é um recurso turístico de particular importância, possuindo simultaneamente aspetos tradicionais e aspetos históricos e sendo uma atração turística fundamental para alguns destinos mundiais. A vila de Óbidos em Portugal é um exemplo de um destino turístico que se soube reinventar e acompanhar a evolução da procura. Nas últimas décadas, assistiu-se a uma evolução em que passou de um destino de turismo cultural tradicional, para um destino turístico com vida, criativo, alavancado por eventos onde existe uma forte presença gastronómica. A atual oferta turística de Óbidos explora bastante a criatividade, permitindo ao turista um desenvolvimento do seu potencial, através da participação ativa em eventos, cursos, workshops, entre outros. Neste estudo, inserido em Doutoramento da Universidad de Córdoba, definiu-se como objetivo principal a análise do perfil, motivações e satisfação dos turistas que visitam Óbidos em relação à criatividade e à gastronomia. Além do objetivo principal, estabeleceram-se objetivos secundários como: caraterizar a evolução histórica do turismo na vila de Óbidos, tendo por base uma estratégia de turismo criativo; Identificar os principais recursos gastronómicos e criativos que são potenciados no destino, bem como aqueles que ainda podem vir a ser alvo de intervenção; Avaliar criticamente o tipo de promoção turística efetuada no domínio da gastronomia e da criatividade percebendo se a mesma é clara e eficaz ao nível da procura; entre outros. Em termos metodológicos foi efetuada pesquisa bibliográfica detalhada, estabelecido um modelo de investigação, foram conduzidas entrevistas com stakeholders e delineado, testado e validado um inquérito por questionário que está a ser aplicado atualmente e que será fulcral para responder ao objetivo principal do estudo. Neste ponto do estudo, podem-se aventar pequenos resultados/conclusões: Óbidos sempre foi um destino turístico preponderante para a Zona Oeste, tendo até ao início do século XX estado bastante ligada ao turismo cultural tradicional, sendo predominantemente um local que atraía visitantes do dia, sem uma estruturação forte do produto turístico; com uma mudança de estratégia turística, centrada em eventos, potenciados pela criatividade e gastronomia, a vila de Óbidos começa a ter um maior desenvolvimento turístico, sendo que hoje em dia pode-se constatar que se encontra na maturidade; Em termos de mercados, Óbidos depende excessivamente do mercado interno, quer em dormidas, quer em visitas; Em termos criativos, constata-se grande dinâmica e trabalho, mas ao nível da gastronomia, verifica-se que não existe uma identidade gastronómica local. A oferta da restauração é variada, mas assenta no receituário português, não se promovendo, à exceção de 2 ou 3 pratos e produtos, uma identidade local, algo que tem que deve ser reconsiderado.
- Pancreatic adenocarcinoma presenting as acute large bowel obstruction: case reportPublication . Gil, Inês Campos; Parente, Diana; Rama, Nuno; Lopes, Branco; Paulino, Virgínia; Amado, Cristina; Cunha, M. Fernanda; Sales, Inês; Faria, VítorIntroduction: Acute large bowel obstruction is a rare presentation of pancreatic cancer, with only six cases described in the revised literature. In all those cases, diagnosis was made either intraoperatively or post-mortem. Case presentation: A 63-year-old man presented in the emergency room with 4 days of bowel constipation associated with abominal pain and distention. Abdominal CT revealed a narrowing at the colonic splenic flexure and the colonoscopy revealed extrinsic compression at 40 cm from the anal verge. The patient was submitted to emergent exploratory laparotomy. We identified a mass involving the colonic splenic flexure, splenic hilum and the pancreatic tail. An en bloc subtotal colectomy, splenectomy and distal pancreatectomy was performed. Final pathology revealed a pancreatic ductal adenocarcinoma. The postoperative period was complicated with fecal peritonitis due to bowel perforation (day 3), hemoperitoneum secondary to pancreatic stump bleeding (day 10) and surgical site infection. The patient was discharged home on day 43. Conclusion: A high level of suspicion is necessary to take into account pancreatic carcinoma as a differential diagnosis of bowel acute obstruction.
- Service Oriented Platform for Drones CompetitionPublication . Ramos, João; Safadinho, David; Ribeiro, Roberto; Pereira, António Manuel de JesusDrones are facing a huge success. They are available almost anywhere, either online or at a near shop, not only for enthusiasts but also for professionals of many areas, such as agriculture, construction, multimedia and military missions. In the same way, online platforms are growing fast. Many applications that we were used to be installed and ran locally in our devices are now deployed in the internet, with the benefits like high availability, high scalability and high compatibility with almost any laptop, computer, smartphone or tablet. Thus, the high level of interest and utility of drones and the crescent demand of service-oriented platforms surged up to be a great fusion of concepts. Nowadays, training and competition requires users to have their own aircraft(s) and to move, usually, to an arena where they can play with each other. Having it in consideration, in this work it's proposed a platform that combines real-time online gaming and drones' training and competition, in which users from around the world can socialize and play together. This paper runs through an overview of the concept, presenting the specifications and the requirements that the platform must meet to accomplish the desired objective. The proposed platform provides access to anyone, anytime, anywhere and with any device. It opens the possibility for users to communicate with each other and to control aircrafts with real-time video transmission, only achievable due to the distributed architecture designed, that minimizes the existence of single points of failure.
- UAV for Everyone : An Intuitive Control Alternative for Drone Racing CompetitionsPublication . Ribeiro, Roberto; Ramos, João; Safadinho, David; Pereira, António Manuel de JesusAs many technological innovations, the Unmanned Aerial Vehicles (UAV) were created for military purposes. However, these aircrafts are now a reality accessible for common civilians and are used to explore new possibilities in areas like cinema, photography or surveillance. The technology easily reached other application fields and turned into a new sports category as well, supported by many drone racing competitions that happen around the world. There are many alternatives to control a quadcopter, but the most accurate relies on a robust and heavy handheld remote controller that requires dexterity to be a good pilot. This limits the control of the UAV to users comfortable with this kind of interaction, discarding people with reduced fine motor skills, hand malformations or elders with low learning capacity from the possibility of piloting a quadcopter and participate in competition events. An alternative to these remote controllers should be developed to overpass the mentioned disadvantages. The solution proposed in this paper is an intuitive and accurate control system made of two small and lightweight wearable devices capable of detecting patterns based on motion events. These patterns are then sent to a mobile application responsible for controlling the drone. Wearing the described devices like a high-tech glove, the users can pilot the UAV through simple and intuitive upper limb movements, being the changes in the orientation of each device over time identified as a specific pattern. This solution presents a new approach to the control of UAV that improves the ease of piloting them and decreases the time that is required to learn how to handle them.
- 3D fast convex-hull-based evolutionary multiobjective optimization algorithmPublication . Zhao, Jiaqi; Jiao, Licheng; Liu, Fang; Basto-Fernandes, Vitor; Yevseyeva, Iryna; Xia, Shixiong; Emmerich, Michael T.M.The receiver operating characteristic (ROC) and detection error tradeoff (DET) curves have been widely used in the machine learning community to analyze the performance of classifiers. The area (or volume) under the convex hull has been used as a scalar indicator for the performance of a set of classifiers in ROC and DET space. Recently, 3D convex-hull-based evolutionary multiobjective optimization algorithm (3DCH-EMOA) has been proposed to maximize the volume of convex hull for binary classification combined with parsimony and three-way classification problems. However, 3DCH-EMOA revealed high consumption of computational resources due to redundant convex hull calculations and a frequent execution of nondominated sorting. In this paper, we introduce incremental convex hull calculation and a fast replacement for non-dominated sorting. While achieving the same high quality results, the computational effort of 3DCH-EMOA can be reduced by orders of magnitude. The average time complexity of 3DCH-EMOA in each generation is reduced from to per iteration, where n is the population size. Six test function problems are used to test the performance of the newly proposed method, and the algorithms are compared to several state-of-the-art algorithms, including NSGA-III, RVEA, etc., which were not compared to 3DCH-EMOA before. Experimental results show that the new version of the algorithm (3DFCH-EMOA) can speed up 3DCH-EMOA for about 30 times for a typical population size of 300 without reducing the performance of the method. Besides, the proposed algorithm is applied for neural networks pruning, and several UCI datasets are used to test the performance.
- Harvesting opinions in Twitter for sentiment analysisPublication . Guevara, Juan; Costa, Joana; Arroba, Jorge; Silva, CatarinaSentiment analysis is a very popular technique for social network analysis. One of the most popular social networks for microblogging that has a great growth is Twitter, which allows people to express their opinions using short, simple sentences. These texts are generated daily, and for this reason it is common for people to want to know which are the trending topics and their drifts. In this paper we propose to deploy a mobile app that provides information focusing on areas, such as, Politics, Social, Tourism, and Marketing using a statistical lexicon approach. The application shows the polarity of each theme as positive, negative, or neutral.