30 research outputs found

    Air pollution effects on the intensity of received signal in 3G/4G mobile terminal

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    In this paper, the existence of the interaction between the atmospheric particulate and the electromagnetic waves attenuation in the frequency band used by the 3G/4G mobile network was investigated. A few papers present in literature indicate, in presence of air pollution, the possibility of a significant cross polarization of the electromagnetic waves, while none of the papers indicated the possibility of a significant attenuation. This paper has tried to partially fill this gap of knowledge in this field with some new contributions. In all the experiments performed at the department of electrical, electronics and informatics engineering in the University of Catania (87 experiments each one lasting about 36 min), significant variations have not been found in the received signal level (RSL), while a polynomial dependency of the RSL local variance from the particulate concentration has been found. To demonstrate that the results obtained in the laboratory have general validity, a campaign test was conducted in an outdoors environment in the frequency band used by the 3G/4G mobile network. The site of the considered measurement station is selected to represent a typical residential area with high traffic influences in the city of Catania. Also, in this measures campaign conducted in the outdoors environment in the 3G/4G frequency band, significant variations have not been found in the RSL. While a marked dependence of the RSL local variance from the PM10{\text {PM}}_{10} concentration has been found. This is a noteworthy result, because certain non-negligible RSL local variance variations indicate the possibility of a pronounced cross polarization. The impact of the cross polarization becomes significant for systems reusing frequency, because the cross polarization counteracts the optimum frequency spectrum utilization

    Cascade feed forward neural network-based model for air pollutants evaluation of single monitoring stations in urban areas

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    In this paper, air pollutants concentrations for N O2 , N O, N Ox and P M 10 in a single monitoring station are predicted using the data coming from other different monitoring stations located nearby. A cascade feed forward neural network based modeling is proposed. The main aim is to provide a methodology leading to the introduction of virtual monitoring station points consistent with the actual stations located in the city of Catania in Italy.

    Toward adaptive heuristic video frames capturing and correction in real-time

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    Multimedia devices are widely used in professional applications as well as personal purposes. The use of computer vision systems enables detection and extraction of important features exposed in images. However constantly increasing demand for this type of video with high quality requires simple however reliable methods. The objective of presented research is to investigate applicability of heuristic method for real-time video frames capturing and correction

    Available bandwidth estimation in smart VPN bonding technique based on a NARX neural network

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    Today many applications require a high Quality of Service (QoS) to the network, especially for real time applications like VoIP services, video/audio conferences, video surveillance, high definition video transmission, etc. Besides, there are many application scenarios for which it is essential to guarantee high QoS in high speed mobility context using an Internet Mobile access. However, internet mobile networks are not designed to support the real-time data traffic due to many factors such as resource sharing, traffic congestion, radio link, coverage, etc., which affect the Quality of Experience (QoE). In order to improve the QoS in mobility scenarios, the authors propose a new technique named "Smart VPN Bonding" which is based on aggregation of two or more internet mobile accesses and is able to provide a higher end-to-end available bandwidth due to an adaptive load balancing algorithm. In this paper, in order to dynamically establish the correct load balancing weights of the smart VPN bonder, a neural network approach to predict the main Key Performance Indicators (KPIs) values in a determinate geographical point is proposed

    A Control Strategy for Mechatronic Action of a Pipe Organ Using a VCM Actuator

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    In pipe organs, the oldest and most commonly chosen system for connecting the organist operator to the source of sound (i.e., the pipes to the action) is mechanical action. This article presents a mechatronic action with a voice coil motor (VCM) actuator to reproduce the action of a mechanical action on pipe organ. The mechatronic action makes it feasible to mechanically separate the keyboard from the pipes and to determine the control strategy for the mechatronic action by utilizing sensors, an actuator and a microcontroller. The time response of the organ pipe with mechanical action and the requirements for mechatronic action were outlined. The control strategy was preceded by measurements of the mechanical action and measurements of the behavior of the VCM actuator system, which moves the pneumatic valve pallet. Two control strategies, open-loop and closed-loop, were proposed and analyzed for the mechatronic action with the VCM actuator. According to the results, the suggested control strategies successfully reproduce the mechanical action’s behavior to a good extent

    Stand for Measurement of the Magnetorheological Fluid Magnetic Permeability

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    Ciecz magnetoreologiczna jest często stosowanym czynnikiem w układach mechatronicznych. Powodem są jej specyficzne właściwości mechaniczne, które zależą od przyłożonego zewnętrznego pola magnetycznego. Głównie stosowane są tam, gdzie wymagana jest zmienna lepkość wspomnianego medium. Pomiar parametrów magnetycznych cieczy jest zadaniem specyficznym i trudnym. Wynika to zarówno ze stanu skupienia (koloid), jak i nietypowych parametrów magnetycznych. Aby pomiar przenikalności magnetycznej był możliwy, należy zastosować konstrukcję, w której rdzeń będzie w postaci walca wykonanego z cieczy. Wokół walca umieszczone są dwie cewki pomiarowe: jedna bezpośrednio okalająca ciecz oraz druga o odpowiednio większej średnicy. Całość znajduje się w solenoidzie, wymuszającym strumień magnetyczny. Dokładność pomiaru uzależniona jest od konfiguracji układu pomiarowego oraz mechanicznej precyzji wykonania każdego z jego elementów. W pracy przedstawiono model matematyczny, sposób działania oraz realizacja techniczna urządzenia do badania przenikalności magnetycznej cieczy magnetoreologicznej. Dla wykonanego urządzenia dokonano pomiarów, gdy współczynnik przenikalności magnetycznej próbki jest znany i równy jedności. Przeprowadzona analiza pomiarów daje podstawy do oceny wykonanego stanowiska pomiarowego.Magnetorheological fluid is a frequently used element in mechatronic systems. The reason is its specific mechanical properties, which depend on the applied external magnetic field. They are mainly used where variable viscosity of said medium is required. Measurement of magnetic parameters of liquids is a specific and challenging task which is due to both the state of aggregation (colloid) and unusual magnetic parameters. To measure the magnetic permeability, a structure in which the core is in the form of a cylinder made of liquid should be used. There are two measuring coils around the cylinder: one directly surrounding the liquid and the other with a correspondingly larger diameter. Everything is contained in a solenoid that forces the magnetic flux. The accuracy of the measurement depends on the configuration of the measuring system and the mechanical precision of each of its elements. The paper presents a mathematical model, method of operation and technical implementation of a device for studying the magnetic permeability of a magnetorheological liquid. Measurements were made for the manufactured device when the magnetic permeability coefficient of the sample is known and equal to one. The conducted analysis of the measurements provides the basis for the evaluation of the developed measuring stand

    A New Iterative FIR Filter Design Approach using a Gaussian Approximation

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    The paper presents a novel iterative methodology for the design of FIR filters based on an approssimation of the desired filter frequency response using a Gabor system generated by the Gaussian function. The proposed method exhibits simplicity of implementation, comparable to that of window-based design methods and ensures accuracy in the fulfillment of design requirements, comparable to the one achieved by the Parks- McClellans method. Furthermore, two other advantages of this method are: closed-form formula for the tap coefficients of the filter and the smooth, monotonically decreasing behaviour of the frequency response from DC to infinite frequency

    Organic solar cells defects detection by means of an elliptical basis neural network and a new feature extraction technique

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    The study proposed in this paper devises to develop a new methodology based on elliptical basisneural network (EBNN) and on a new feature extraction technique in order to recognize theorganic solar cells (OSCs) defects. The feature extraction procedure has been obtained by usingthe co-occurrence matrices and the SVD decomposition applied to atomic microscope forceimagery. The polymer-based OSCs used for this work have been produced at the optoelectronicorganic semiconductor devices laboratory at Ben Gurion University of the Negev. The testsperformed show that with our approach it is possible to obtain a correct classification percentageof 95.4% proving that the proposed feature extraction technique based on the co-occurrenceMatrix and the SVD decomposition is very effective in the detection of different types of OSC surface defects
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