Abstract
Products should guarantee a sufficiently high user experience for all intended user groups. A good user experience means not only that it is sufficient to allow users to work effectively and efficiently with a product, but also that non-task-related quality aspects need to be considered. To attain various levels of user experience thus requires an efficient method to access the subjective impressions of a larger number of users toward the product. The authors show that this can be done with little effort by using a user experience questionnaire. However, such questionnaires must be adapted to the language and even to the level of language understanding of the intended target groups. Using the example of the creation of a Portuguese language version and a special version for children, the paper illustrates how the quality of the resulting adapted questionnaire can be evaluated.

Abstract
The realization of tabletop optical analogue experiments of superfluidity relies on the engineering of suitable optical media, with tailored optical properties. This work shows how quantum atomic optical systems can be used to develop highly tunable optical media, with localized control of both linear and nonlinear susceptibility. Introducing the hydrodynamic description of light, the superfluidity of light in these atomic media is investigated through GPU-enhanced numerical simulations, with the numeric observation of the superfluidic signature of suppressed scattering through a defect.

Abstract
Este volume pretende abarcar algumas das evoluções atuais e devido à transformação digital. O mundo está em constante mutação e devido à verdadeira revolução e transformação digital esta mudança tem ocorrido a passos muito rápidos e de forma imprevisível – o que faz com que seja difícil fazer previsões a cinco anos e sobre como estarão certas indústrias afetadas pela tecnologia, no futuro. As redes sociais online modificaram a forma como nos expomos e apresentamos. Os smartphones tornaram tudo mais móvel – temos grandes computadores, muito potentes, no nosso bolso e connosco todos os dias. O negócio das apps e do software mudou de paradigma – o que conta são os seguidores e muito do software agora é grátis. Vejamos o caso do Facebook, do Instagram, e até do WhatsApp – plataformas grátis. Querem é utilizar os utentes como receptáculos de publicidade e para fins comerciais que outrora eram muito diferentes e até impensáveis. Em tal ambiente a pressão sobre os gestores e os agentes na sociedade, com poder de decisão, está em níveis nunca antes vistos. Por um lado, são exigidas empresas competitivas e que façam uso da tecnologia, tecnologia que muitas das vezes é nova e tem custos assim como perigos. A privacidade da informação, quer de adultos, quer de crianças, é fundamental. Nunca antes os nossos jovens tiveram acesso a tanta informação e de forma praticamente grátis. A Internet mudou radicalmente como acedemos à informação e ao conhecimento e os pais deixaram de ser a resposta para tudo e para todas as questões dos seus filhos – tendo sido substituídos, em muitos casos, por motores de busca como o Google, e outros (dependendo também da geografia do consumidor, sendo a China uma região grande e preponderante, mas que tem regras e instituições muito próprias). Também na sala de aula os educadores, em especial no ensino superior, se deparam com esta nova realidade em que, se fazem perguntas às quais o Google tem resposta, terão dificuldade em assegurar salas cheias de alunos. Os alunos querem adquirir conhecimento tácito sobre o qual o Google não informa. Este é somente um exemplo dos desafios que a tecnologia coloca. Fica também o desafio ao leitor para nos ajudar a cocriar um futuro cada vez mais igual e não cada vez mais desigual. Mandem-nos, por favor, as vossas sugestões sobre como acompanhar a revolução no meio da qual vivemos hoje em dia. Por último, gostaríamos de agradecer encarecidamente aos autores dos diversos capítulos do livro, pela sua dedicação aos temas, pela sua originalidade, e pela sua paciência e cooperação na revisão dos materiais submetidos.

Abstract
The Achilles tendon has a unique structure-function relationship thanks to its innate hierarchical architecture in combination with the rotational anatomy of the sub-tendons from the triceps surae muscles. Previous research has provided valuable insight in global Achilles tendon mechanics, but limitations with the technique used remain. Furthermore, given the global approach evaluating muscle-tendon junction to insertion, regional differences in tendon mechanical properties might be overlooked. However, recent advancements in the field of ultrasound imaging in combination with speckle tracking have made an intratendinous evaluation possible. This study uses high-frequency ultrasound to allow for quantification of regional tendon deformation. Also, an interactive application was developed to improve clinical applicability. A dynamic ultrasound of both Achilles tendons of ten asymptomatic subjects was taken. The displacement and regional strain in the superficial, middle and deep layer were evaluated during passive elongation and isometric contraction. Building on previous research, results showed that the Achilles tendon displaces non-uniformly with a higher displacement found in the deep layer of the tendon. Adding to this, a non-uniform regional strain behavior was found in the Achilles tendon during passive elongation, with the highest strain in the superficial layer. Further exploration of tendon mechanics will improve the knowledge on etiology of tendinopathy and provide options to optimize existing therapeutic loading programs.

Abstract
This article presents the design and evaluation of an algorithm for urinary bladder segmentation in medical images, from contrastless computed tomography studies of patients suffering from bladder wall tumours. These situations require versatile methods of segmentation, able to adapt to the structural changes the tumours provoke in the bladder wall, reflected as irregularities on the images obtained, creating adversities to the segmentation process. This semi-automatic method uses fuzzy c-means clustering, a Gaussian-curve-based intensity transformation, and active contour models, requiring only the physician's input of a single seed point for each anatomical view, in order to segment the bladder volume in all frames that include it. The performance of the method was evaluated on eight patients of The Cancer Genome Atlas-Urothelial Bladder Carcinoma collection, achieving approximately 79% of successful segmentations for small tumour patients (below 2.0 cm of diameter) and approximately 72% between 2.0 and 2.9 cm. Successful segmentations for small tumour patients presented an average of 3.7 mm Hausdorff distance and 91.0% degree of overlap. The promising performance attained, especially for small tumour patients, revealed a high potential of this method to serve as basis for an effective early-stage bladder wall tumour computer-aided diagnosis system.

Abstract
The aim of this study is twofold: first, to present a survey of the actual and most advanced methods related to the use of unmanned aerial systems (UASs) that emerged in the past few years due to the technological advancements that allowed the miniaturization of components, leading to the availability of small-sized unmanned aerial vehicles (UAVs) equipped with Global Navigation Satellite Systems (GNSS) and high quality and cost-effective sensors; second, to advice the target audience - mostly farmers and foresters - how to choose the appropriate UAV and imaging sensor, as well as suitable approaches to get the expected and needed results of using technological tools to extract valuable information about agroforestry systems and its dynamics, according to their parcels' size and crop's types. Following this goal, this work goes beyond a survey regarding UAS and their applications, already made by several authors. It also provides recommendations on how to choose both the best sensor and UAV, in according with the required application. Moreover, it presents what can be done with the acquired sensors' data through theuse of methods, procedures, algorithms and arithmetic operations. Finally, some recent applications in the agroforestry research area are presented, regarding the main goal of each analysed studies, the used UAV, sensors, and the data processing stage to reach conclusions.