1,647 research outputs found

    Analog-Digital System Modeling for Electromagnetic Susceptibility Prediction

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    The thesis is focused on the noise susceptibility of communication networks. These analog-mixed signal systems operate in an electrically noisy environment, in presence of multiple equipments connected by means of long wiring. Every module communicates using a transceiver as an interface between the local digital signaling and the data transmission through the network. Hence, the performance of the IC transceiver when affected by disturbances is one of the main factors that guarantees the EM immunity of the whole equipment. The susceptibility to RF and transient disturbances is addressed at component level on a CAN transceiver as a test case, highlighting the IC features critical for noise immunity. A novel procedure is proposed for the IC modeling for mixed-signal immunity simulations of communication networks. The procedure is based on a gray-box approach, modeling IC ports with a physical circuit and the internal links with a behavioural block. The parameters are estimated from time and frequency domain measurements, allowing accurate and efficient reproduction of non-linear device switching behaviours. The effectiveness of the modeling process is verified by applying the proposed technique to a CAN transceiver, involved in a real immunity test on a data communication link. The obtained model is successfully implemented in a commercial solver to predict both the functional signals and the RF noise immunity at component level. The noise immunity at system level is then evaluated on a complete communication network, analyzing the results of several tests on a realistic CAN bus. After developing models for wires and injection probes, a noise immunity test in avionic environment is carried out in a simulation environment, observing good overall accuracy and efficiency

    Experimental characterization of a Circular Diaphragm Dielectric Elastomer Generators

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    Inflated Circular Diaphragm Dielectric Elastomer Generators (CD-DEGs) are a special embodiment of polymeric transducer that can be used to convert pneumatic energy into high-voltage direct-current electricity. Potential application of CD-DEGs is as power take-off system for wave energy converters that are based on the oscillating water column principle. Optimal usage of CD-DEGs requires the adequate knowledge of their dynamic electro-mechanical response. This paper presents a test-rig for the experimental study of the dynamic response of CD-DEGs under different programmable electro-mechanical loading conditions. Experimental results acquired on the test-rig are also presented, which highlight the dynamic performances of CD-DEGs that are based on acrylic elastomer membranes and carbon conductive grease electrodes

    Auditory navigation with a tubular acoustic model for interactive distance cues and personalized head-related transfer functions: an auditory target-reaching task

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    This paper presents a novel spatial auditory display that combines a virtual environment based on a Digital Waveguide Mesh (DWM) model of a small tubular shape with a binaural rendering system with personalized head-related transfer functions (HRTFs) allowing interactive selection of absolute 3D spatial cues of direction as well as egocentric distance. The tube metaphor in particular minimizes loudness changes with distance, providing mainly direct-to-reverberant and spectral cues. The proposed display was assessed through a target-reaching task where participants explore a 2D virtual map with a pen tablet and hit a sound source (the target) using auditory information only; subjective time to hit and traveled distance were analyzed for three experiments. The first one aimed at assessing the proposed HRTF selection method for personalization and dimensionality of the reaching task, with particular attention to elevation perception; we showed that most subjects performed better when they had to reach a vertically unbounded (2D) rather then an elevated (3D) target. The second experiment analyzed interaction between the tube metaphor and HRTF showing a dominant effect of DWM model over binaural rendering. In the last experiment, participants using absolute distance cues from the tube model performed comparably well to when they could rely on more robust, although relative, intensity cues. These results suggest that participants made proficient use of both binaural and reverberation cues during the task, displayed as part of a coherent 3D sound model, in spite of the known complexity of use of both such cues. HRTF personalization was beneficial for participants who were able to perceive vertical dimension of a virtual sound. Further work is needed to add full physical consistency to the proposed auditory display

    Eliciting the Functional Taxonomy from protein annotations and taxa

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    The advances of omics technologies have triggered the production of an enormous volume of data coming from thousands of species. Meanwhile, joint international efforts like the Gene Ontology (GO) consortium have worked to provide functional information for a vast amount of proteins. With these data available, we have developed FunTaxIS, a tool that is the first attempt to infer functional taxonomy (i.e. how functions are distributed over taxa) combining functional and taxonomic information. FunTaxIS is able to define a taxon specific functional space by exploiting annotation frequencies in order to establish if a function can or cannot be used to annotate a certain species. The tool generates constraints between GO terms and taxa and then propagates these relations over the taxonomic tree and the GO graph. Since these constraints nearly cover the whole taxonomy, it is possible to obtain the mapping of a function over the taxonomy. FunTaxIS can be used to make functional comparative analyses among taxa, to detect improper associations between taxa and functions, and to discover how functional knowledge is either distributed or missing. A benchmark test set based on six different model species has been devised to get useful insights on the generated taxonomic rules

    Science Museum in a Pizza Box - Performance, museum tour guiding, and science communication

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    This study focuses on the relationship between performance and museum tour guiding. Building on the analysis of this relationship, the author of this study has created a performance that is inspired by museum guided tours. The aim of the performance is to encourage a critical reflection on the role and the function of science in contemporary society, while giving insight into how science is socially constructed. The performance is based on participation. The participants define their own experiences, actively reflecting on the value that science has in their lives through a dialogue with the other participants and the performer. This dialogue starts with exhibits based on science that are presented to the participants. To develop this performance, this research has utilised action research, and qualitative methods to explore the participants’ experiences of the performance. This study is interdisciplinary, and connects performance studies, museum studies and science communication, while using applied research to explore its topics. The outcomes of this study are an innovative conceptualisation of the museum guided tour, and an original approach to science communication based on dialogic, live performance

    Up the nose of the beholder? Aesthetic perception in olfaction as a decision-making process

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    Is the sense of smell a source of aesthetic perception? Traditional philosophical aesthetics has centered on vision and audition but eliminated smell for its subjective and inherently affective character. This article dismantles the myth that olfaction is an unsophisticated sense. It makes a case for olfactory aesthetics by integrating recent insights in neuroscience with traditional expertise about flavor and fragrance assessment in perfumery and wine tasting. My analysis concerns the importance of observational refinement in aesthetic experience. I argue that the active engagement with stimulus features in perceptual processing shapes the phenomenological content, so much so that the perceptual structure of trained smelling varies significantly from naive smelling. In a second step, I interpret the processes that determine such perceptual refinement in the context of neural decision-making processes, and I end with a positive outlook on how research in neuroscience can be used to benefit philosophical aesthetics

    Jamming Signal Immunity Tests on GSM-R Communications Compared to EMC Basic Standards

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    This paper presents the work being done in SECRET project (European Program FP7/2007-2013 under grant agreement number “285136”) to strengthen the European rail network against the potential jamming of the railway communications. Standardized immunity tests, currently conducted on communication equipment in the presence of electromagnetic (EM) interferences are presented. It then presents the tests carried out in SECRET to assess the resistance of railway communication systems face the signals generated by telecommunication jammers.SECRE

    A new class of variable capacitance generators based on the dielectric fluid transducer

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    This paper introduces the novel concept of dielectric fluid transducer (DFT), which is an electrostatic variable capacitance transducer made by compliant electrodes, solid dielectrics and a dielectric fluid with variable volume and/or shape. The DFT can be employed in actuator mode and generator mode. In this work, DFTs are studied as electromechanical generators able to convert oscillating mechanical energy into direct current electricity. Beside illustrating the working principle of dielectric fluid generators (DFGs), we introduce different architectural implementations and provide considerations on limitations and best practices for their design. Additionally, the proposed concept is demonstrated in a preliminary experimental test campaign conducted on a first DFG prototype. During experimental tests a maximum energy per cycle of and maximum power of has been converted, with a conversion efficiency up to 30%. These figures correspond to converted energy densities of with respect to the displaced dielectric fluid and with respect to the mass of the solid dielectric. This promising performance can be largely improved through the optimization of device topology and dimensions, as well as by the adoption of more performing conductive and dielectric materials

    Including Urban Metabolism Principles in Decision-Making: A Methodology for Planning Waste and Resource Management

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    Circular economy and urban metabolism concepts have recently received great attention both in the political and academic arenas, starting a roll-over process of the \u201ctake, make, and dispose\u201d dominant economic model that is leading to an ongoing increase of resource consumption and waste generation. However, there is a relative lack of guidelines for introducing such concepts in a decision-making process able to support the design of appropriate policies and strategies and the definition of specific actions to cope with such challenges. This paper attempts to contribute to the recent efforts at incorporating these concepts in policy and decision-making processes by providing a methodology for the development of strategic plans for waste prevention and resource management. The proposed methodology, developed within the Urban_WINS project, combines different quantitative\u2013analytical and qualitative methods and tools, together with a participatory process. The methodology was tested in eight EU cities and allowed to formulate several measures and actions aimed at addressing the challenges posed by the current consumption patterns. Moreover, the participatory approach led to the legitimization of the strategic plans, as well as to raise awareness among stakeholders. Although it might require specific tailor-made adjustments, this methodology is suitable to be replicated in other contexts
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