16 research outputs found

    Signal Processing Using Non-invasive Physiological Sensors

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    Non-invasive biomedical sensors for monitoring physiological parameters from the human body for potential future therapies and healthcare solutions. Today, a critical factor in providing a cost-effective healthcare system is improving patients' quality of life and mobility, which can be achieved by developing non-invasive sensor systems, which can then be deployed in point of care, used at home or integrated into wearable devices for long-term data collection. Another factor that plays an integral part in a cost-effective healthcare system is the signal processing of the data recorded with non-invasive biomedical sensors. In this book, we aimed to attract researchers who are interested in the application of signal processing methods to different biomedical signals, such as an electroencephalogram (EEG), electromyogram (EMG), functional near-infrared spectroscopy (fNIRS), electrocardiogram (ECG), galvanic skin response, pulse oximetry, photoplethysmogram (PPG), etc. We encouraged new signal processing methods or the use of existing signal processing methods for its novel application in physiological signals to help healthcare providers make better decisions

    Emotion and Stress Recognition Related Sensors and Machine Learning Technologies

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    This book includes impactful chapters which present scientific concepts, frameworks, architectures and ideas on sensing technologies and machine learning techniques. These are relevant in tackling the following challenges: (i) the field readiness and use of intrusive sensor systems and devices for capturing biosignals, including EEG sensor systems, ECG sensor systems and electrodermal activity sensor systems; (ii) the quality assessment and management of sensor data; (iii) data preprocessing, noise filtering and calibration concepts for biosignals; (iv) the field readiness and use of nonintrusive sensor technologies, including visual sensors, acoustic sensors, vibration sensors and piezoelectric sensors; (v) emotion recognition using mobile phones and smartwatches; (vi) body area sensor networks for emotion and stress studies; (vii) the use of experimental datasets in emotion recognition, including dataset generation principles and concepts, quality insurance and emotion elicitation material and concepts; (viii) machine learning techniques for robust emotion recognition, including graphical models, neural network methods, deep learning methods, statistical learning and multivariate empirical mode decomposition; (ix) subject-independent emotion and stress recognition concepts and systems, including facial expression-based systems, speech-based systems, EEG-based systems, ECG-based systems, electrodermal activity-based systems, multimodal recognition systems and sensor fusion concepts and (x) emotion and stress estimation and forecasting from a nonlinear dynamical system perspective

    Self-adaptive fitness in evolutionary processes

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    Most optimization algorithms or methods in artificial intelligence can be regarded as evolutionary processes. They start from (basically) random guesses and produce increasingly better results with respect to a given target function, which is defined by the process's designer. The value of the achieved results is communicated to the evolutionary process via a fitness function that is usually somewhat correlated with the target function but does not need to be exactly the same. When the values of the fitness function change purely for reasons intrinsic to the evolutionary process, i.e., even though the externally motivated goals (as represented by the target function) remain constant, we call that phenomenon self-adaptive fitness. We trace the phenomenon of self-adaptive fitness back to emergent goals in artificial chemistry systems, for which we develop a new variant based on neural networks. We perform an in-depth analysis of diversity-aware evolutionary algorithms as a prime example of how to effectively integrate self-adaptive fitness into evolutionary processes. We sketch the concept of productive fitness as a new tool to reason about the intrinsic goals of evolution. We introduce the pattern of scenario co-evolution, which we apply to a reinforcement learning agent competing against an evolutionary algorithm to improve performance and generate hard test cases and which we also consider as a more general pattern for software engineering based on a solid formal framework. Multiple connections to related topics in natural computing, quantum computing and artificial intelligence are discovered and may shape future research in the combined fields.Die meisten Optimierungsalgorithmen und die meisten Verfahren in Bereich künstlicher Intelligenz können als evolutionäre Prozesse aufgefasst werden. Diese beginnen mit (prinzipiell) zufällig geratenen Lösungskandidaten und erzeugen dann immer weiter verbesserte Ergebnisse für gegebene Zielfunktion, die der Designer des gesamten Prozesses definiert hat. Der Wert der erreichten Ergebnisse wird dem evolutionären Prozess durch eine Fitnessfunktion mitgeteilt, die normalerweise in gewissem Rahmen mit der Zielfunktion korreliert ist, aber auch nicht notwendigerweise mit dieser identisch sein muss. Wenn die Werte der Fitnessfunktion sich allein aus für den evolutionären Prozess intrinsischen Gründen ändern, d.h. auch dann, wenn die extern motivierten Ziele (repräsentiert durch die Zielfunktion) konstant bleiben, nennen wir dieses Phänomen selbst-adaptive Fitness. Wir verfolgen das Phänomen der selbst-adaptiven Fitness zurück bis zu künstlichen Chemiesystemen (artificial chemistry systems), für die wir eine neue Variante auf Basis neuronaler Netze entwickeln. Wir führen eine tiefgreifende Analyse diversitätsbewusster evolutionärer Algorithmen durch, welche wir als Paradebeispiel für die effektive Integration von selbst-adaptiver Fitness in evolutionäre Prozesse betrachten. Wir skizzieren das Konzept der produktiven Fitness als ein neues Werkzeug zur Untersuchung von intrinsischen Zielen der Evolution. Wir führen das Muster der Szenarien-Ko-Evolution (scenario co-evolution) ein und wenden es auf einen Agenten an, der mittels verstärkendem Lernen (reinforcement learning) mit einem evolutionären Algorithmus darum wetteifert, seine Leistung zu erhöhen bzw. härtere Testszenarien zu finden. Wir erkennen dieses Muster auch in einem generelleren Kontext als formale Methode in der Softwareentwicklung. Wir entdecken mehrere Verbindungen der besprochenen Phänomene zu Forschungsgebieten wie natural computing, quantum computing oder künstlicher Intelligenz, welche die zukünftige Forschung in den kombinierten Forschungsgebieten prägen könnten

    Applied Metaheuristic Computing

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    For decades, Applied Metaheuristic Computing (AMC) has been a prevailing optimization technique for tackling perplexing engineering and business problems, such as scheduling, routing, ordering, bin packing, assignment, facility layout planning, among others. This is partly because the classic exact methods are constrained with prior assumptions, and partly due to the heuristics being problem-dependent and lacking generalization. AMC, on the contrary, guides the course of low-level heuristics to search beyond the local optimality, which impairs the capability of traditional computation methods. This topic series has collected quality papers proposing cutting-edge methodology and innovative applications which drive the advances of AMC

    Real-time Control and Optimization of Water Supply and Distribution infrastructure

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    Across North America, water supply and distribution systems (WSDs) are controlled manually by operational staff - who place a heavy reliance on their experience and judgement when rendering operational decisions. These decisions range from scheduling the operation of pumps, valves and chemical dosing in the system. However, due to the uncertainty of demand, stringent water quality regulatory constraints, external forcing (cold/drought climates, fires, bursts) from the environment, and the non-stationarity of climate change, operators have the tendency to control their systems conservatively and reactively. WSDs that are operated in such fashion are said to be 'reactive' because: (i) the operators manually react to changes in the system behaviour, as measured by Supervisory Control and Data Acquisition (SCADA) systems; and (ii) are not always aware of any anomalies in the system until they are reported by consumers and authorities. The net result is that the overall operations of WSDs are suboptimal with respect to energy consumption, water losses, infrastructure damage and water quality. In this research, an intelligent platform, namely the Real-time Dynamically Dimensioned Scheduler (RT-DDS), is developed and quantitatively assessed for the proactive control and optimization of WSD operations. The RT-DDS platform was configured to solve a dynamic control problem at every timestep (hour) of the day. The control problem involved the minimization of energy costs (over the 24-hour period) by recommending 'near-optimal' pump schedules, while satisfying hydraulic reliability constraints. These constraints were predefined by operational staff and regulatory limits and define a tolerance band for pressure and storage levels across the WSD system. The RT-DDS platform includes three essential modules. The first module produces high-resolution forecasts of water demand via ensemble machine learning techniques. A water demand profile for the next 24-hours is predicted based on historical demand, ambient conditions (i.e. temperature, precipitation) and current calendar information. The predicted profile is then fed into the second module, which involves a simulation model of the WSD. The model is used to determine the hydraulic impacts of particular control settings. The results of the simulation model are used to guide the search strategy of the final module - a stochastic single solution optimization algorithm. The optimizer is parallelized for computational efficiency, such that the reporting frequency of the platform is within 15 minutes of execution time. The fidelity of the prediction engine of the RT-DDS platform was evaluated with an Advanced Metering Infrastructure (AMI) driven case study, whereby the short-term water consumption of the residential units in the city were predicted. A Multi-Layer Perceptron (MLP) model alongside ensemble-driven learning techniques (Random forests, Bagging trees and Boosted trees) were built, trained and validated as part of this research. A three-stage validation process was adopted to assess the replicative, predictive and structural validity of the models. Further, the models were assessed in their predictive capacity at two different spatial resolutions: at a single meter and at the city-level. While the models proved to have strong generalization capability, via good performance in the cross-validation testing, the models displayed slight biases when aiming to predict extreme peak events in the single meter dataset. It was concluded that the models performed far better with a lower spatial resolution (at the city or district level) whereby peak events are far more normalized. In general, the models demonstrated the capacity of using machine learning techniques in the context of short term water demand forecasting - particularly for real-time control and optimization. In determining the optimal representation of pump schedules for real-time optimization, multiple control variable formulations were assessed. These included binary control statuses and time-controlled triggers, whereby the pump schedule was represented as a sequence of on/off binary variables and active/idle discrete time periods, respectively. While the time controlled trigger representation systematically outperformed the binary representation in terms of computational efficiency, it was found that both formulations led to conditions whereby the system would violate the predefined maximum number of pump switches per calendar day. This occurred because at each timestep the control variable formulation was unaware of the previously elapsed pump switches in the subsequent hours. Violations in the maximum pump switch limits lead to transient instabilities and thus create hydraulically undesirable conditions. As such, a novel feedback architecture was proposed, such that at every timestep, the number of switches that had elapsed in the previous hours was explicitly encoded into the formulation. In this manner, the maximum number of switches per calendar day was never violated since the optimizer was aware of the current trajectory of the system. Using this novel formulation, daily energy cost savings of up to 25\% were achievable on an average day, leading to cost savings of over 2.3 million dollars over a ten-year period. Moreover, stable hydraulic conditions were produced in the system, thereby changing very little when compared to baseline operations in terms of quality of service and overall condition of assets

    Applied Methuerstic computing

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    For decades, Applied Metaheuristic Computing (AMC) has been a prevailing optimization technique for tackling perplexing engineering and business problems, such as scheduling, routing, ordering, bin packing, assignment, facility layout planning, among others. This is partly because the classic exact methods are constrained with prior assumptions, and partly due to the heuristics being problem-dependent and lacking generalization. AMC, on the contrary, guides the course of low-level heuristics to search beyond the local optimality, which impairs the capability of traditional computation methods. This topic series has collected quality papers proposing cutting-edge methodology and innovative applications which drive the advances of AMC

    Multidisciplinary Design Optimization of Electric Aircraft Considering Systems Modeling and Packaging

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    Electric aircraft propulsion is an intriguing path towards sustainable aviation, but the technological challenges are significant. Bulky and heavy electrical components such as batteries create spatial integration and aircraft performance challenges, especially for longer-range aircraft. A common thread among all aircraft with electric propulsion is the close coupling of aircraft design disciplines, such as aerodynamics, structures, propulsion, controls, and thermal management. Multidisciplinary design optimization (MDO) is a promising technique for solving design problems with many closely-coupled physical disciplines. The first half of this dissertation focuses on MDO of electric aircraft considering systems modeling. First, design of electric aircraft is reviewed in detail from the perspective of the various disciplines. Next, methods and models for electric aircraft propulsion systems are introduced. A case study involving a general aviation airplane is explored in order to validate the performance of the methods and generate some insight into the tradespace for series hybrid aircraft. The systems modeling approach is then extended to include basic thermal management systems. The prior case study is revisisted while considering thermal constraints. Impact of thermal management on aircraft performance is assessed. The thermal management analysis methods are validated using flight test data from the Pipistrel Velis Electro, finding good agreement between experiment and simulation. Finally, an MDO model of a parallel hybrid electric transport aircraft with a liquid-cooled thermal management system is constructed. Sensitivities of aircraft performance with respect to important technologies parameters are computed. This first half introduces the first publicly-available simulation tool that can handle unsteady thermal states and that offers efficient and accurate gradients. The methods are very efficient, enabling users to perform dozens or hundreds of optimization runs in a short amount of time using modest computational resources. Other novel contributions include the first empirical validation of thermal management models for MDO against real flight test data, as well as the only comprehensive look so far at the unsteady thermal management of a transport-scale parallel hybrid aircraft. The second half of the dissertation introduces novel methods for performing high-fidelity shape optimization studies subject to packaging or spatial integration constraints. A new mathematical formulation for generalized packaging constraints is introduced. The constraint formulation is demonstrated on simple aerodynamic shape optimization test cases. Next, a wing design study involving optimal battery packaging is conducted in order to demonstrate the coupling of outer mold line design and propulsion system component design via spatial integration. Finally, a more complex aerostructural optimization involving the wing of a hydrogen aircraft is constructed and solved. These test cases demonstrate the interdisciplinary coupling introduced by packaging constraints, as well as the impact of spatial integration on aircraft performance. This latter half contributes a powerful new way for MDO engineers to pose realistic spatial constraints in their shape optimization problems, thus solving an important practical barrier to the industrial adoption of MDO for certain relevant problems. This work also represents the first time an MDO problem has been posed and solved for an aircraft using hydrogen fuel in the wing. Altogether, this dissertation significantly advances the state of the art in modeling, simulation, and optimization tools for aircraft with electric propulsion architectures and introduces new insights into the design spaces for several diverse aircraft configurations.PHDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169658/1/bbrelje_1.pd

    Challenges in the design of tension moored floating wind turbines

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    In order to harness the extensive offshore wind resource, both in Ireland and in many parts of the world with deep offshore seas, the deployment of wind turbines on floating structures is required. Tension moored floating wind turbines are one type of platform with potential to be used for such deployments. These highly constrained platforms offer many benefits but also unique challenges compared against other platform stability types. This thesis investigated the use of such platforms through a combination of numerical simulations and experimental wave basin tank testing. Design improvements in an existing platform, HEXWIND, are identified, leading to the design of a novel platform, TWind. As tension moored platforms are highly constrained in heave, pitch and roll motions, a significant coupling and design complexity is introduced between the wind turbines flexible tower and the pitch/roll motions. The effect of this tower flexibility is parametrised in this work. As tension moored platforms rely on the tendon pretension for stability, operations such as installation and maintenance towing without tendons are statically unstable. Additional float for tow stability are designed and analysed in this work. These floats are designed to become wave energy converters once the platform is installed on site. The structural dynamic and hydrodynamic interaction effects of including these WEC are analysed in detail. Novel survival modes for the WEC floats are proposed. Design considerations related to potential tendon anchor misplacement are also analysed. A platform parameter study has led to a greater understanding of the design effects of modifying the floating concept dimensions. The addition of active WEC on the TMFWT is seen to significantly increase the platform forces and dynamics, with the tower root bending moment doubling compared to the standalone TMFWT. With 100's of GW's of proposed floating offshore wind capacity to be developed this century, the results from this thesis help improve the state of the art in tension moored floating wind design, installation and survivability

    Full Proceedings, 2018

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    Full conference proceedings for the 2018 International Building Physics Association Conference hosted at Syracuse University

    Review of Particle Physics

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    The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings
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