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  1. 21

    Urban Sound Event Detection and Classification

    Publication
    by Alves, João
    Other Authors: Guerreiro, Pedro; Marques, Gonçalo; Paulo, Joel
    The ability to automatically detect/classify complex and dynamic urban sounds is important tool for urban planning such as building efficient noise monitoring and control, surveillance systems, urban soundscape mappings, and could be a foundation for improvement of life in the cities of tomorrow.We present a proof of concept for a sound detection, monitoring and classification system for urban environments in the context of Smart Cities. Ultimately, the proposed system be deployed in numerous urban locations for long periods of time, allowing for the collection of urban acoustic data.
  2. 22

    Function and Meaning: The Double Aspects of Technology

    Publication
    by Feenberg, Andrew
    This paper traces the theoretical background to the split between function and meaning in the modernity theories of Marx, Lukács, Weber and Marcuse. It then discusses attempts to overcome the split in the recent philosophies of technology of Simpson and Borgmann. These attempts fail but help to focus the issue. A discussion of contemporary struggles over information technology offers a more hopeful perspective on a possible resolution of the split and suggests a new look at Heidegger’s phenomenology of action. The conclusion of the paper shows that Heidegger offers resources for addressing the relation of function and meaning which he himself did not develop.
  3. 23

    Floating sensor platform for the monitoring of water quality in urban and white-water environments

    Publication
    by Neitzert, Heinz Christoph
    Other Authors: Baltes, Michael; Scmitt, Roman; Lovisi, P; Landi, G; Cuomo, A et al.
    In the present paper the project of an embeddedsolution for the realization of a floating sensor platform for themonitoring of the water and ambient quality in a flowing waterenvironment is described. First results regarding the monitoringof the water conductivity and the ambient noise level underharsh environmental conditions in a karstic river and in the finalpart of a river going towards the Mediterranean Sea arepresented. It is further discussed how this kind of system can bemodified in order to serve as urban waterway multisensoryplatform, adding important features like connectivity, energyharvesting and determination of the platform position. 
  4. 24

    Intelligent Sensors for Real-Time Hazard Detection and Visual Indication on Highways

    Publication
    by Oliveira, J.
    Other Authors: Soares, J.; Lourenço, A. R.; Duarte, Rui
    Traffic collisions, in particular high speed car accidents often result in huge damages, long traffic queues and loss of human lives. In this work we present an intelligent modular system that monitors traffic in highways and alerts drivers of sudden stops, in poor visual conditions. The system is composed of several identical modules, to be placed in the middle of a highway’s lane, that sense the lights and communicate their presence and velocity to their neighbor modules via RF. With such information, the nearby modules estimate the velocity of the passing cars. When the module ahead detects a car passing at a much slower speed than what was previously estimated, it alerts the other modules, so they produce a visual indication for the oncoming drivers, preventing accidents. The system operates autonomously using solar energy harvesting.
  5. 25

    Comparing Layer 1 and Layer 3 Relay Stations Deployment in a LTE Network

    Publication
    by Martins, André
    Other Authors: Vieira, Pedro; Rodrigues, António
    The relay solution in planning of mobile networks, has the aim of increasing the network coverage and/or capacity. According to the open literature, this technique will be highly used in the next Long Term Evolution (LTE) Networks. The Relay Station (RS) performance varies with its position in the cell, with the radio conditions to which RSs and User Equipments (UEs) are subjected and with the RS capacity to receive, process and forward the information. The aim of this paper is to compare the performance of the Layer 1 (L1) and Layer 3 (L3) RS types, and to determine the ideal position in which a RS should be placed, with the aim of maximizing the UE throughput.
  6. 26

    Applications for a-Si:H TFTs: Modelling and Simulation

    Publication
    by Lourenço, Paulo
    Other Authors: Fantoni, Alessandro; Fernandes, Luis; Costa, João; Vieira, Manuela
    Hydrogenated amorphous silicon thin film transistors have been used as switching elements in liquid crystal displays and large area matrix addressed sensor arrays. Later, these devices have also been used as analogue active elements in organic light emitting diode displays. However, this technology suffers from bias induced meta-stability. This issue introduces both threshold voltage and subthreshold slope shifts over time when gate bias is applied. Such instabilities jeopardize long term performance of circuits that rely on these components. Nevertheless, hydrogenated amorphous silicon thin film transistors present an exponential transfer characteristic when operating on subthreshold region and their typical power consumption is under 1 µW. This low power characteristic makes these devices ideally suited for low power electronic design.This work demonstrates, through transient analysis of a well-established simulation model for hydrogenated amorphous silicon, the viability of thin film transistors technology to perform both analogue and digital functions. Hence, these structures may be used in both application fields. To this end, two different sets of analyses have been conducted with hydrogenated amorphous silicon based thin film transistors. The first set considers a driving circuit for an active matrix of organic light emitting diodes, biased in a way to minimize the “memory effect” (increasing shift on threshold voltage) due to long term operation. The second set of analyses were conducted upon the implementation of complementary output universal gates, namely NOR/OR and XNOR/XOR elements.
  7. 27

    Radio over Fiber (RoF): A comparison of low-cost systems

    Publication
    by Almeida, Márcio
    Other Authors: Pinho, Pedro; Ramos, Fernando
    In order to assess the potential of low-cost radio-over-fiber (RoF) solutions, in this paper we make a comparison of three full-duplex RoF systems. These systems are low-cost solutions that use remote modulation, with a single centralized light source used at the central station to generate a downlink wavelength that is reused at the remote location for upstream transmission. By avoiding the need for an additional light source at each remote location the cost of the solution is significantly reduced. The three systems evaluated in this paper differ by the type of optical modulation used for downlink and uplink. The first is an IM-IM system using intensity-modulation (IM) for the downlink and uplink direction. The second scheme, PM-IM, differs from the first by using phase-modulation (PM) for downlink. Finally, the third system, PM-PM, uses phase modulation for downlink and uplink.
  8. 28

    Stochastic Theater: Stochastic Datapath Generation Framework for Fault-Tolerant IoT Sensors

    Publication
    by Duarte, Rui Policarpo
    Other Authors: Véstias, Mário; Carvalho, Carlos; Casaleiro, João
    Stochastic Computing has emerged as a competitive computing paradigm that produces fast and simple implementations of arithmetic operations, while offering high levels of parallelism, and graceful degradation of the results when in the presence of errors. IoT devices are often operate under limited power and area constraints and subjected to harsh environments, for which, traditional computing paradigms struggle to provide high availability and fault-tolerance. Stochastic Computing is based on the computation of pseudo-random sequences of bits, hence requiring only a single bit per signal, rather than a data-bus. Notwithstanding, we haven’t witnessed its inclusion in custom computing systems. In this direction, this work presents Stochastic Theater, a framework to specify, simulate, and test Stochastic Datapaths to perform computations using stochastic bitstreams targeting IoT systems. In virtue of the granularity of the bitstreams, the bit-level specification of circuits, high-performance characteristics and reconfigurable capabilities, FPGAs were adopted to implement and test such systems. The proposed framework creates Stochastic Machines from a set of user defined arithmetic expressions, and then tests them with the corresponding input values and specific fault injection patterns. Besides the support to create autonomous Stochastic Computing systems, the presented framework also provides generation of stochastic units, being able to produce estimates on performance, resources and power. A demonstration is presented targeting KLT, typical method for data compression in IoT applications.
  9. 29

    Autonomic Function Evaluation in an Intermittent Lead Exposure Animal Model

    Publication
    by Shvachiy, Liana
    Other Authors: Geraldes, Vera; Carvalho, Mafalda; Rocha, Isabel
    Lead (Pb) is a toxic metal, which widespread use has resulted in environmental contamination, human exposure and significant public health problems. The autonomic nervous system, being a homeostatic controller, is impaired in acute and chronic lead exposure. In fact, sympathoexcitation associated to hypertension and tachypnea has been described together with baroreflex and chemoreflex dysfunction. However, up to date, no studies described the autonomic effects of an intermittent low-level lead exposure. In the present work, we addressed in vivo, autonomic behaviour in rats under chronic Pb exposure (control) and in rats under intermittent Pb exposure. For that, arterial blood pressure (BP) and ECG were recorded in 28 weeks old animal and low frequencies (LF) and high frequencies (HF) were determined (to estimate sympathetic and parasympathetic activities) using FisioSinal software with Wavelet module. Preliminary results: Rats intermittently exposed to lead showed a significant decrease in systolic BP (126 ± 4 vs 144 ± 3 mmHg) with no significant changes in LF, HF and LF/HF bands (1.5 ± 0.3 vs 1.7 ± 0.5 mmHg2, 1.9 ± 0.7 vs 2.8 ± 1.2 bpm2 and 1.2 ± 0.4 vs 1.1 ± 0.3 mmHg2/bpm2, respectively) when compared to chronically Pb exposed rats. Our data suggests that the autonomic dysfunction induced by lead exposure is similar in a chronic and intermittent Pb exposure. Nevertheless, it seems that an intermittent exposure was no effect on systolic BP values.The present study brings new insights on the environmental factors that influence autonomic and cardiovascular systems during development, which can help apprise public policy strategies to prevent and control the adverse effects of Pb toxicity.
  10. 30

    Automatic Acoustic Scene Classification

    Publication
    by Marques, Gonçalo Caetano
    Other Authors: Langlois, Thibault
    This paper presents a baseline system for automatic acoustic scene classification based on the audio signals alone. The proposed method  is derived from classic, content-based, music classification approaches, and consists in a feature extraction phase followed by two dimensionality reduction steps (PCA and LDA) and a classification phase done using a k nearest-neighbors algorithm.This paper also reports on how our system performed  in the context of the DCASE 2016 challenge, for the acoustic scene classification task.