How high can expectations go? Practitioner issues and risks of interactive installations

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Fostering collaboration in kindergarten through an augmented reality game

Kindergarten children are a very special class of users, since they are in a primary stage of life, when they must learn how to live in society, e.g. to listen and respect the others’ opinions, share the same objects and also help each other. This study presents an Augmented Reality game, in which kinder garten children were able to collaborate in a spontaneous way supported by motivation, enjoyment and curiosity. This game allows children to explore concepts like the animals and the en vironments they live in by using Augmented Reality markers and a wooden board. These markers are the game pieces and through them children are able to manipulate 3D virtual models. Experiments were performed with several classes of students in different schools. Results suggest that the game is effective in maintaining high levels of motivation and collaboration among children, particularly when using immediate feedback.info:eu-repo/semantics/publishedVersio

Reaction-diffusion wave fronts : multigeneration biological species under climate change

A generalization of reaction-diffusion models to multigeneration biological species is presented. It is based on more complex random walks than those in previous approaches. The new model is developed analytically up to infinite order. Our predictions for the speed agree to experimental data for several butterfly species better than existing models. The predicted dependence for the speed on the number of generations per year allows us to explain the change in speed observed for a specific invasion

Deep Neural Networks with Trainable Activations and Controlled Lipschitz Constant

We introduce a variational framework to learn the activation functions of deep neural networks. Our aim is to increase the capacity of the network while controlling an upper-bound of the actual Lipschitz constant of the input-output relation. To that end, we first establish a global bound for the Lipschitz constant of neural networks. Based on the obtained bound, we then formulate a variational problem for learning activation functions. Our variational problem is infinite-dimensional and is not computationally tractable. However, we prove that there always exists a solution that has continuous and piecewise-linear (linear-spline) activations. This reduces the original problem to a finite-dimensional minimization where an l1 penalty on the parameters of the activations favors the learning of sparse nonlinearities. We numerically compare our scheme with standard ReLU network and its variations, PReLU and LeakyReLU and we empirically demonstrate the practical aspects of our framework

On the maximization of control power in low-speed flight

The present work extends existing knowledge on the subject in two directions: (i) on theoretical side by allowing for the deflections of multiple control surfaces, that gives more options to obtain the desired forces or moments with less risk of flow separation or aeroelastic effects; (ii) on the application side by considering not only minimum drag but also maximum drag (e.g. for fast descent) and maximum control moments for emergencies, such an engine-out condition. These applications are made to a FW, extending the scope of the literature that concentrates mostly on minimum drag for pitch trim in cruise. Thus the present paper is also a contribution to the expanding literature on various aspects of the BWB aircraft

A responsabilidade civil no âmbito da circulação automática (Automated Driving Systems – ADS) de veículos na via pública

Exame público realizado a1 de fevereiro de 2021Dissertação de mestrado em Direito, área de Ciências Jurídicas Civilísticas, Universidade Lusíada, Porto, 2020Esta Tese de Dissertação de Mestrado em Ciências Juridicas Civilisticas, tem por título A Responsabilidade Civil no Âmbito da Circulação Automática de Veículos na Via Pública. O objetivo foi o de contribuir para o conhecimento da temática dos sistemas automáticos de condução automóvel (ADS). Estes compõem-se em três níveis de automação: 3, 4 e 5. Este último, significa que, em última instância, a figura do condutor de um veículo não existe mais, passando a ser conduzido por ligação a um sistema partilhado de circulação pública. Algumas modificações nas normas do Direito Civil, em Portugal, impor-se-ão, mormente no que concerne ao artigo 493 do (CC, 2016), bem como a subsunção do regime a aplicar que surge deste, para além de alterações no Código da Estrada e do seguro automóvel obrigatório. A noção de circulação terrestre, para os níveis 3, 4 e 5, também carece de modificações, bem como o artigo 499.º e o conceito de direção efetiva, com o artigo 503.º. O artigo 350.º, número 2, igualmente.This Master's Dissertation Thesis in Civil Juridical Sciences, is entitled Civil Liability in the Field of Automated Driving Systems of Vehicles on Public Road. The objective was to contribute to the knowledge of the topic of automated driving systems (ADS). These consist of three levels of automation: 3, 4 and 5. The latter means that, ultimately, the figure of the driver of a vehicle no longer exists, and is now driven by connection to a shared public circulation system. Some changes in the rules of Civil Law in Portugal will be imposed, especially with regard to article 493 of (CC, 2016), as well as the subsumption of the regime to be applied that arises from this, in addition to changes in the Highway Code and compulsory motor insurance. The notion of land circulation, for levels 3, 4 and 5, also needs modifications, as well as article 499 and the concept of effective direction, with article 503. Article 350, paragraph 2, also

On the Extrapolation of Stability Derivatives to Combined Changes in Airspeed and Angles of Attack and Sideslip

The variation in stability derivatives with airspeed and angles of attack and sideslip is determined using only the dependence of the aerodynamic forces and moments on the modulus and direction of the velocity. Analytic extrapolation factors are obtained for all 12 longitudinal plus 12 lateral stability derivatives of linear decoupled motion. The extrapolation factors relate the stability derivatives for two flight conditions with different airspeeds, angles of attack (AoA), and angles of sideslip (AoS). The extrapolation formulas were validated by comparison with results of computational fluid dynamics (CFD) using Reynolds-averaged Navier–Stokes (RANS) equations. The comparison concerns the extrapolated full longitudinal–lateral stability matrix from one landing and one takeoff condition of a V-tailed aircraft, to 10 other landing and takeoff flight cases with different airspeeds, AoAs, and AoSs. Thus, 420 comparisons were made between extrapolated stability derivatives and CFD–RANS results demonstrating the achievable levels of accuracy

On the maximization of control power in low-speed flight for a BWB configuration

The maximization of control power is considered for an aircraft with multiple control surfaces, which may be decoupled or coupled; the force and moment coefficients are specified by polynomials of the control surface deflections, of any degree not less than two. The optimal deflections, which maximize and minimize any force or moment coefficient are determined subject to constraints on the range of deflection of each control surface. The results are applied to a flying wing configuration to determine: (i/ii) the pitch trim, at the lowest drag for the fastest climb, and at the highest drag for the steepest descent; (iii) the maximum and minimum pitching moment and the associated range of trimmed c.g. positions for several engine configurations; (iv) the maximum and minimum yaw control power and the fraction needed to compensate an outboard engine failure for several propulsion configurations; (v) the maximum and minimum rolling moment and the strongest wake vortex which can be compensated. The optimal case of all control surfaces has significant advantages over using just one, e.g., the range of drag modulation with pitch trim is much wider and the maximum and minimum available control moments larger