1,398 research outputs found

    Intelligent ultrasound hand gesture recognition system

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    With the booming development of technology, hand gesture recognition has become a hotspot in Human-Computer Interaction (HCI) systems. Ultrasound hand gesture recognition is an innovative method that has attracted ample interest due to its strong real-time performance, low cost, large field of view, and illumination independence. Well-investigated HCI applications include external digital pens, game controllers on smart mobile devices, and web browser control on laptops. This thesis probes gesture recognition systems on multiple platforms to study the behavior of system performance with various gesture features. Focused on this topic, the contributions of this thesis can be summarized from the perspectives of smartphone acoustic field and hand model simulation, real-time gesture recognition on smart devices with speed categorization algorithm, fast reaction gesture recognition based on temporal neural networks, and angle of arrival-based gesture recognition system. Firstly, a novel pressure-acoustic simulation model is developed to examine its potential for use in acoustic gesture recognition. The simulation model is creating a new system for acoustic verification, which uses simulations mimicking real-world sound elements to replicate a sound pressure environment as authentically as possible. This system is fine-tuned through sensitivity tests within the simulation and validate with real-world measurements. Following this, the study constructs novel simulations for acoustic applications, informed by the verified acoustic field distribution, to assess their effectiveness in specific devices. Furthermore, a simulation focused on understanding the effects of the placement of sound devices and hand-reflected sound waves is properly designed. Moreover, a feasibility test on phase control modification is conducted, revealing the practical applications and boundaries of this model. Mobility and system accuracy are two significant factors that determine gesture recognition performance. As smartphones have high-quality acoustic devices for developing gesture recognition, to achieve a portable gesture recognition system with high accuracy, novel algorithms were developed to distinguish gestures using smartphone built-in speakers and microphones. The proposed system adopts Short-Time-Fourier-Transform (STFT) and machine learning to capture hand movement and determine gestures by the pretrained neural network. To differentiate gesture speeds, a specific neural network was designed and set as part of the classification algorithm. The final accuracy rate achieves 96% among nine gestures and three speed levels. The proposed algorithms were evaluated comparatively through algorithm comparison, and the accuracy outperformed state-of-the-art systems. Furthermore, a fast reaction gesture recognition based on temporal neural networks was designed. Traditional ultrasound gesture recognition adopts convolutional neural networks that have flaws in terms of response time and discontinuous operation. Besides, overlap intervals in network processing cause cross-frame failures that greatly reduce system performance. To mitigate these problems, a novel fast reaction gesture recognition system that slices signals in short time intervals was designed. The proposed system adopted a novel convolutional recurrent neural network (CRNN) that calculates gesture features in a short time and combines features over time. The results showed the reaction time significantly reduced from 1s to 0.2s, and accuracy improved to 100% for six gestures. Lastly, an acoustic sensor array was built to investigate the angle information of performed gestures. The direction of a gesture is a significant feature for gesture classification, which enables the same gesture in different directions to represent different actions. Previous studies mainly focused on types of gestures and analyzing approaches (e.g., Doppler Effect and channel impulse response, etc.), while the direction of gestures was not extensively studied. An acoustic gesture recognition system based on both speed information and gesture direction was developed. The system achieved 94.9% accuracy among ten different gestures from two directions. The proposed system was evaluated comparatively through numerical neural network structures, and the results confirmed that incorporating additional angle information improved the system's performance. In summary, the work presented in this thesis validates the feasibility of recognizing hand gestures using remote ultrasonic sensing across multiple platforms. The acoustic simulation explores the smartphone acoustic field distribution and response results in the context of hand gesture recognition applications. The smartphone gesture recognition system demonstrates the accuracy of recognition through ultrasound signals and conducts an analysis of classification speed. The fast reaction system proposes a more optimized solution to address the cross-frame issue using temporal neural networks, reducing the response latency to 0.2s. The speed and angle-based system provides an additional feature for gesture recognition. The established work will accelerate the development of intelligent hand gesture recognition, enrich the available gesture features, and contribute to further research in various gestures and application scenarios

    Assessment of microplastics and other contaminants in marine vertebrates from the Western Mediterranean Sea

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    Mediterranean marine biodiversity is under threat by pollution. For this reason, the main objective of this thesis was to analyse the presence of pollutants of concern in Mediterranean marine species. These studies are located in the Valencian Community (Spain), where we find loggerhead turtles, striped dolphins, and jewel lanternfish. Hence, we: 1. Analysed pesticides, heavy metals and phthalates in tissues of loggerhead turtles. 2. Studied microdebris present in beaches that are sporadically used as nesting grounds by loggerhead turtles. 3. Analysed striped dolphins# exposure to microplastics. 4. Quantified jewel lanternfish exposure to microplastics and tested their role as bioindicators of microplastic pollution in the bathypelagic environment. Results indicate the ubiquity of all the analysed pollutants. Pesticide analyses showed that all the analysed loggerheads (N=25) were exposed to 39 pesticides, of which 38.5% are forbidden in the EU. Results indicated low heavy metal burden. Mean concentrations of Cd, Pb and Hg were 0.04 μg/g., 0.09 μg/g. and 0.03 μg/g w.w. in fat and 0.05 μg/g, 0.08 μg/g and 0.04 μg/g w.w. in muscle. The juvenile size could account for these low concentrations. Seven phthalate metabolites in turtles were detected in more than 85% of the samples (DR>85%). The sum of the median concentration of the phthalate metabolites that had DR>85%, showed a negative correlation with size and also a significant increase in concentration from 2020 onwards; possibly explained by an increase in single-use plastic, or by uncontrolled wastewater discharges. Microdebris in beaches was ubiquitous although concentrations were not of concern for the success of loggerhead turtle clutches. In July, total mean±SD was 5.66 ± 3.66 MPs/kg at surface and 12.15 ± 7.76 MPs/kg at depth; while in November values were 6.45 ± 4.42 MPs/kg at surface and 5.51 ± 3.14 MPs/kg at depth. There were no significant differences among beaches, months, depths nor protection regime. Polymers found were commonly used in consumer goods and tires.MPs were present in 90.5% of the striped dolphins (N=43), although amount per dolphin was low and variable (median = 5, range = 0 - 82). Polyacrylamide, PET and HDPE were the most common polymers. MPs concentration from different periods of time (1989 # 2007/2010#2017) or locations were not different. Finally, the jewel lanternfish, (N=97), showed high frequency of occurrence of MPs, although a low body burden. Size and body condition were not correlated with the number of MPs. To sum up, an overview of the pollutants in the westernmost part of the Mediterranean Sea is provided, focusing on the aforementioned species and highlighting their potential as bioindicators

    What Makes a Habitat a Home: Understanding Settlement and Recruitment Variation in European Sea Bass, Dicentrarchus labrax

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    Sea bass stocks in the UK are in decline as a result of increased fishing pressure and variable inter-annual recruitment. Recruitment variation is driven by survival in the early life stages; therefore, nursery habitats are thought to be able to stabilize recruitment through providing optimal growth conditions for juvenile fish. A thorough understanding of the factors that drive juvenile sea bass survival is needed, however, our understanding of what constitutes quality nursery habitat for juvenile sea bass is weak, with current knowledge based almost solely on saltmarshes. Juvenile sea bass were sampled using conventional seine and fyke nets across estuarine habitats, alongside dietary DNA metabarcoding to assess their distribution diet and condition, using measures of abundance, condition, stomach fullness, and diet. To determine whether the mechanism of larvae entering estuarine nurseries is an active or passive process the vertical distribution patterns of larval sea bass were compared across tidal cycles. Finally, over-winter survival was predicted based on energy budget modelling and temperature-dependent growth experiments, based on in-situ measurements of winter temperatures. Juvenile sea bass did not differentially select high tide habitats, but saltmarshes and sand provided increased foraging success. At low tide, however, sea bass were more abundant in complex habitat with lower foraging success. Diets mainly consisted of decapods and polychaete worms across habitats, but there was evidence of increased planktivory over mud. Larval sea bass did not show evidence of flood tide transport and likely rely on passive tidal forcing to migrate into estuaries, or they are trying to retain to deeper water. According to our models, winter thermal minima resulted in complete cohort loss in all scenarios on the East coast. The results of this study suggest that multiple habitats along the estuarine mosaic are important for juvenile sea bass at some point, and that a seascape approach to management is necessary, however, winter temperatures likely present a more extreme bottleneck to recruitment

    Systemic Circular Economy Solutions for Fiber Reinforced Composites

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    This open access book provides an overview of the work undertaken within the FiberEUse project, which developed solutions enhancing the profitability of composite recycling and reuse in value-added products, with a cross-sectorial approach. Glass and carbon fiber reinforced polymers, or composites, are increasingly used as structural materials in many manufacturing sectors like transport, constructions and energy due to their better lightweight and corrosion resistance compared to metals. However, composite recycling is still a challenge since no significant added value in the recycling and reprocessing of composites is demonstrated. FiberEUse developed innovative solutions and business models towards sustainable Circular Economy solutions for post-use composite-made products. Three strategies are presented, namely mechanical recycling of short fibers, thermal recycling of long fibers and modular car parts design for sustainable disassembly and remanufacturing. The validation of the FiberEUse approach within eight industrial demonstrators shows the potentials towards new Circular Economy value-chains for composite materials

    Reshaping Higher Education for a Post-COVID-19 World: Lessons Learned and Moving Forward

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    IMAGINING, GUIDING, PLAYING INTIMACY: - A Theory of Character Intimacy Games -

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    Within the landscape of Japanese media production, and video game production in particular, there is a niche comprising video games centered around establishing, developing, and fulfilling imagined intimate relationships with anime-manga characters. Such niche, although very significant in production volume and lifespan, is left unexplored or underexplored. When it is not, it is subsumed within the scope of wider anime-manga media. This obscures the nature of such video games, alternatively identified with descriptors including but not limited to ‘visual novel’, ‘dating simulator’ and ‘adult computer game’. As games centered around developing intimacy with characters, they present specific ensembles of narrative content, aesthetics and software mechanics. These ensembles are aimed at eliciting in users what are, by all intents and purposes, parasocial phenomena towards the game’s characters. In other words, these software products encourage players to develop affective and bodily responses towards characters. They are set in a way that is coherent with shared, circulating scripts for sexual and intimate interaction to guide player imaginative action. This study defines games such as the above as ‘character intimacy games’, video game software where traversal is contingent on players knowingly establishing, developing, and fulfilling intimate bonds with fictional characters. To do so, however, player must recognize themselves as playing that type of game, and to be looking to develop that kind of response towards the game’s characters. Character Intimacy Games are contingent upon player developing affective and bodily responses, and thus presume that players are, at the very least, non-hostile towards their development. This study approaches Japanese character intimacy games as its corpus, and operates at the intersection of studies of communication, AMO studies and games studies. The study articulates a research approach based on the double need of approaching single works of significance amidst a general scarcity of scholarly background on the subject. It juxtaposes data-driven approaches derived from fan-curated databases – The Visual Novel Database and Erogescape -Erogē Hyƍron KĆ«kan – with a purpose-created ludo-hermeneutic process. By deploying an observation of character intimacy games through fan-curated data and building ludo-hermeneutics on the resulting ontology, this study argues that character intimacy games are video games where traversal is contingent on players knowingly establishing, developing, and fulfilling intimate bonds with fictional characters and recognizing themselves as doing so. To produce such conditions, the assemblage of software mechanics and narrative content in such games facilitates intimacy between player and characters. This is, ultimately, conductive to the emergence of parasocial phenomena. Parasocial phenomena, in turn, are deployed as an integral assumption regarding player activity within the game’s wider assemblage of narrative content and software mechanics

    Modern meat: the next generation of meat from cells

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    Modern Meat is the first textbook on cultivated meat, with contributions from over 100 experts within the cultivated meat community. The Sections of Modern Meat comprise 5 broad categories of cultivated meat: Context, Impact, Science, Society, and World. The 19 chapters of Modern Meat, spread across these 5 sections, provide detailed entries on cultivated meat. They extensively tour a range of topics including the impact of cultivated meat on humans and animals, the bioprocess of cultivated meat production, how cultivated meat may become a food option in Space and on Mars, and how cultivated meat may impact the economy, culture, and tradition of Asia

    Measuring the impact of COVID-19 on hospital care pathways

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    Care pathways in hospitals around the world reported significant disruption during the recent COVID-19 pandemic but measuring the actual impact is more problematic. Process mining can be useful for hospital management to measure the conformance of real-life care to what might be considered normal operations. In this study, we aim to demonstrate that process mining can be used to investigate process changes associated with complex disruptive events. We studied perturbations to accident and emergency (A &E) and maternity pathways in a UK public hospital during the COVID-19 pandemic. Co-incidentally the hospital had implemented a Command Centre approach for patient-flow management affording an opportunity to study both the planned improvement and the disruption due to the pandemic. Our study proposes and demonstrates a method for measuring and investigating the impact of such planned and unplanned disruptions affecting hospital care pathways. We found that during the pandemic, both A &E and maternity pathways had measurable reductions in the mean length of stay and a measurable drop in the percentage of pathways conforming to normative models. There were no distinctive patterns of monthly mean values of length of stay nor conformance throughout the phases of the installation of the hospital’s new Command Centre approach. Due to a deficit in the available A &E data, the findings for A &E pathways could not be interpreted
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