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Wyniki wyszukiwania dla: OPTICAL FIBER SENSORS
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Dual-wavelength laser polarimeter and its performance capabilities
PublikacjaA dual-wavelength optical polarimetric approach has been proposed as a means of elimination of the systematic errors and estimation of the optical anisotropy parameters for a single DKDP crystal. Our HAUP-related polarimeter uses two semiconductor lasers with the neighbouring wavelengths of 635 nm and 650 nm. Based on the temperature dependence analysis of small characteristic azimuths of light polarization with respect to the...
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Zarządzanie zaufaniem w bezprzewodowych sieciach czujników - studium przypadku
PublikacjaW artykule przedstawiono studium przypadku dotyczące zastosowania bezprzewodowej sieci czujników do wspomagania pacjenta z nadwagą w jego środowisku domowym. Przyjęto, że sieć wykorzystuje metodę rozproszonego zarządzania zaufaniem i pokazano, że metoda ta umożliwia wykrycie i izolację czujników realizujących działania sprzeczne z polityką sieci. Ilościowe oszacowanie czasu niezbędnego do wykrycia takich...
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STUDY OF ARRAY OF MEMS INERTIAL MEASUREMENT UNITS UNDER QUASI-STATIONARY AND DYNAMIC CONDITIONS
PublikacjaA measurement system includes all components in a chain of hardware and software that leads from a measured variable to processed data. In that context, the type and quality of the sensors or measuring devices are critical to any measurement system. MEMS/IMU sensors lag behind leading technologies in this respect, but the MEMS/IMU performance rapidly changes while is relatively inexpensive. For this reason, the paper proposes...
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Influence of operation temperature instability on gas sensor performance
PublikacjaGas sensors based on the semiconducting metal-oxides, such as SnO2, have been found to be very useful for detecting a wide range of gases. The reversible interactions of the gas with the surface of the sensing layer made of semiconducting metal-oxides are responsible for changes of sensor resistance which is usually used as a measure of sensor response. Semiconductor gas sensors are commercially available and applied in numerous...
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Combined analysis of whole human blood parameters by Raman spectroscopy and spectral-domain low-coherence interferometry
PublikacjaIn this article the simultaneous investigation of blood parameters by complementary optical methods, Raman spectroscopy and spectral-domain low-coherence interferometry, is presented. Thus, the mutual relationship between chemical and physical properties may be investigated, because low-coherence interferometry measures optical properties of the investigated object, while Raman spectroscopy gives information about its molecular...
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Nitrogen dioxide gas-sensing detection with GO modified CuO thin films
PublikacjaGas sensors have been continuously developed over the last few decades for several applications including air quality monitoring, automotive industry and recently for medical use. Gas sensors are usually based on metal oxides (MOXs), such as SnO2, TiO2, ZnO, WO3, CuO. Recently, new materials such as graphene oxide and heterostructures of graphene oxide and metal oxides are utilized for gassensing applications.
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Properties of Nasicon-based CO2 sensor with Bi8Nb2O17 reference electrode
PublikacjaGas sensors are useful for the carbon dioxide concentration monitoring in many applications. The major challenge is to develop a potentiometric sensor working without the necessity of a reference gas and without a need of the reference electrode encapsulation. Important issue is a selection of reference electrode material, which should provide stable reference potential. For example as reference electrode material in sensor based...
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Development of novel optoelectronic sensory structures utilising colour centres in nanodiamonds and their interactions with analytes
PublikacjaThe goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA),...
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Asynchronous WAM with Irregular Pulse Repetition
PublikacjaRadiolocation systems for aviation based on Multi-Lateration (MLAT) typically use a set of synchronised ground sensors to receive radio signals broadcast by onboard transmitters. In most cases, the sensor synchronisation in Wide Area Multi-Lateration Systems (WAM) is provided by Global Navigation Satellite System (GNSS) receivers. However, in the case of synchronisation failure, there is still a possibility to estimate the coordinates...
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A novel hierarchically-porous diamondized polyacrylonitrile sponge-like electrodes for acetaminophen electrochemical detection
PublikacjaA novel composite electrode material consisting of tangled fibrous polyacrylonitrile-based hierarchically-struc- tured nanocomposites has been produced by wet-spinning, carbonized and decorated with a carbon nano- architecture by microwave plasma-enhanced chemical vapor deposition and investigated as a metal-free electrode for the enhanced electrochemical detection of acetaminophen. Surprisingly, the hierarchical fiber ar- chitecture...
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Experimental Studies of Concrete-Filled Composite Tubes under Axial Short- and Long-Term Loads
PublikacjaThe paper presents experimental studies on axially compressed columns made of concrete-filled glass fiber reinforced polymer (GFRP) tubes. The infill concrete was C30/37 according to Eurocode 2. The investigated composite pipes were characterized by different angles of fiber winding in relation to the longitudinal axis of the element: 20, 55 and 85 degrees. Columns of two lengths, 0.4 m and 2.0 m, were studied. The internal diameter...
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublikacjaThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Progress in module design for membrane distillation
PublikacjaThere have been tremendous advances in membrane distillation (MD) since the concept was introduced in 1961: new membrane designs and process configurations have emerged, and its commercial viability has been evaluated in several pilot-scale studies. However, its high energy consumption has hindered its commercialization. One of the most promising ways to overcome this obstacle is to develop more energy-efficient membrane modules....
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Embedded gas sensing setup for air samples analysis
PublikacjaThis paper describes a measurement setup (eNose) designed to analyze air samples containing various volatile organic compounds (VOCs). The setup utilizes a set of resistive gas sensors of divergent gas selectivity and sensitivity. Some of the applied sensors are commercially available and were proposed recently to reduce their consumed energy. The sensors detect various VOCs at sensitivities determined by metal oxide sensors’ technology...
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Research of leakage magnetic field in deenergized transformer
PublikacjaThe article deals with the issue of the numerical analysis of the magnetic field occurring around the transformer after it has been powered down. The main goal of this analysis was to examine if it is possible to identify the residual fluxes in the transformer legs based on this fields’ measurements. It was also intended to determine the type and the location of magnetic sensors. Numerical analysis of the magnetic field was performed....
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A diplexer design method using an augmented channel filter approach
PublikacjaContinuous development in RFID andmicrocontrollers technologies gives new possibilities to createsystems that are able to integrate a lot of sensors based ondifferent technologies. This integration brings us closer to realizethe Ubiquitous Network Society vision. However, many problemsmust be addressed before we will benefit from such systems. Inthis paper we describe concept of integrating RFID technologywith other sensors technologies...
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Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties
PublikacjaA graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. To obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at a constant potential of −0.85 V. The GO, RGO and PEDOT-RGO...
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Application of ionic liquids in electronic nose instruments
PublikacjaAmong many applications in different fields of science and technology the ionic liquids (ILs) are also utilised in chemical sensors yielding improvement of their operation parameters (Buzzeo, 2004; Wei and Ivaska, 2008; Silvester, 2011; Gebicki et al., 2013). Some of these chemical sensors are the components of the devices, which resemble human sense of smell as far as their operation is concerned. These devices are named electronic...
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A general theory for anisotropic Kirchhoff–Love shells with in-plane bending of embedded fibers
PublikacjaThis work presents a generalized Kirchhoff–Love shell theory that can explicitly capture fiber-induced anisotropy not only in stretching and out-of-plane bending, but also in in-plane bending. This setup is particularly suitable for heterogeneous and fibrous materials such as textiles, biomaterials, composites and pantographic structures. The presented theory is a direct extension of classical Kirchhoff–Love shell theory to incorporate...
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Noise spectral density computation based on finite element model of piezoceramic sensor
PublikacjaThe high sensitivity with wide bandwidth is required for sensor applications in non-destructive testing (NDT). The sensitivity of piezoceramic sensors demands to minimize their noise especially thermal noise, polarisation noise and low frequency 1/f noise,which are the main sources of voltage or current fluctuation in this sort of sensors. For simplicity, only the piezoceramic part of sensor was under study. the theoretical and...
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The Concept of Geodetic Analyses of the Measurement Results Obtained by Hydrostatic Leveling
PublikacjaThe article discusses the issue of hydrostatic leveling. Its application is presented in structural health monitoring systems in order to determine vertical displacements of controlled points. Moreover, the article includes a complete computation scheme that utilizes the estimation from observation differences, allowing the elimination of the influence of individual sensors’ systematic errors. The authors suggest two concepts of...
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Pracujący w czasie rzeczywistym system detekcji gazów wykorzystujący przenośny komputer Raspberry PI oraz matrycę półprzewodnikowych czujników gazu
PublikacjaThe gas-analyzing systems based on the array of partially selective gas sensors and pattern-recognition techniques are potentially fast and lowcost alternative for other devices, like gas‑analysers. They give the possibility of recognition the type and the concentration of measured volatile compounds in their working environment. In this work we present the implementation of gas recognition system, in which the signals from an...
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Research on protection mechanisms of Resilient Packet Ring Network.
PublikacjaPaper describes iSteering - a new method to control traffic in case of RPR network failure. There's comparison of packet wrapping, steering and our proposed method iSteering, which can be used in case of transmitter/receiver or fiber failure. Numerical analysis for even and random traffic flow has been made in order to compare packet wrapping, steering and iSteering. The results of all the tests are included.
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Acoustic Sensing Analytics Applied to Speech in Reverberation Conditions
PublikacjaThe paper aims to discuss a case study of sensing analytics and technology in acoustics when applied to reverberation conditions. Reverberation is one of the issues that makes speech in indoor spaces challenging to understand. This problem is particularly critical in large spaces with few absorbing or diffusing surfaces. One of the natural remedies to improve speech intelligibility in such conditions may be achieved through speaking...
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Eventual Convergence of the Reputation-Based Algorithm in IoT Sensor Networks
PublikacjaUncertainty in dense heterogeneous IoT sensor networks can be decreased by applying reputation-inspired algorithms, such as the EWMA (Exponentially Weighted Moving Average) algorithm, which is widely used in social networks. Despite its popularity, the eventual convergence of this algorithm for the purpose of IoT networks has not been widely studied, and results of simulations are often taken in lieu of the more rigorous proof....
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Dipodal Tetraamide Derivatives of 1,10-Diaza-18-Crown-6 and Alkylmalonic Acids—Synthesis and Use as Ionophores in Ion Selective Membrane Electrodes
PublikacjaNovel dipodal derivatives of an 18-membered diaza-crown ether with two diamide chains featuring methylmalonic or butylmalonic acid residues were obtained and tested as ionophores in ion-selective plasticized membrane electrodes. The objective of the study was to identify measurement conditions which ensure the most favorable performance for magnesium ion-selective electrodes. The relationship between the molar lipophilic anion...
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Face with Mask Detection in Thermal Images Using Deep Neural Networks
PublikacjaAs the interest in facial detection grows, especially during a pandemic, solutions are sought that will be effective and bring more benefits. This is the case with the use of thermal imaging, which is resistant to environmental factors and makes it possible, for example, to determine the temperature based on the detected face, which brings new perspectives and opportunities to use such an approach for health control purposes. The...
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Wood Moisture-Content Measurement Accuracy of Impregnated and Nonimpregnated Wood
PublikacjaThe influence of the impregnation process of pine wood (Pinus sylvestris L.) samples on the electrical resistance changes and the moisture-content measurement accuracy is presented in this paper. In this study, the resistances of impregnated and nonimpregnated green pine timber harvested from northern Poland were compared. An impregnation method based on a vacuum-pressure chamber was used. Copper salts were applied as the impregnated...
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Keystroke Dynamics Patterns While Writing Positive and Negative Opinions
PublikacjaThis paper deals with analysis of behavioural patterns in human–computer interaction. In the study, keystroke dynamics were analysed while participants were writing positive and negative opinions. A semi-experiment with 50 participants was performed. The participants were asked to recall the most negative and positive learning experiences (subject and teacher) and write an opinion about it. Keystroke dynamics were captured and...
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Computational Methods for Liver Vessel Segmentation in Medical Imaging: A Review
PublikacjaThe segmentation of liver blood vessels is of major importance as it is essential for formulating diagnoses, planning and delivering treatments, as well as evaluating the results of clinical procedures. Different imaging techniques are available for application in clinical practice, so the segmentation methods should take into account the characteristics of the imaging technique. Based on the literature, this review paper presents...
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Software-Defined NB-IoT Uplink Framework - The Design, Implementation and Use Cases
PublikacjaIn the radiocommunication area, we may observe a rapid growth of new technology, such as 5G. Moreover, all the newly introduced radio interfaces, e.g., narrowband Internet of Things (NB-IoT), are strongly dependent on the software. Hence, the radiocommunication software development and optimization, as well as the 3GPP technical specification, should be introduced at the academic level of education. In this paper, a software-defined...
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Ensuring the QoE-Related Fairness to Reduce the User Abandonment Ratio
PublikacjaThese days, it is quite a challenge for app owners to keep users engaged with an app. Currently, the level of user abandonment is one of the key parameters that application owners are interested in. To meet these challenges, we are conducting an extended study of a previously proposed solution that significantly reduces the abandonment rate of a given application. The investigated solution is based on the methods of fairness using...
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Monitoring of Caged Bluefin Tuna Reactions to Ship and Offshore Wind Farm Operational Noises
PublikacjaUnderwater noise has been identified as a relevant pollution affecting marine ecosystems in different ways. Despite the numerous studies performed over the last few decades regarding the adverse effect of underwater noise on marine life, a lack of knowledge and methodological procedures still exists, and results are often tentative or qualitative. A monitoring methodology for the behavioral response of bluefin tuna (Thunnus thynnus)...
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Analysis of GNSS, Hydroacoustic and Optoelectronic Data Integration Methods Used in Hydrography
PublikacjaThe integration of geospatial data in hydrography, performed using different measurement systems, involves combining several study results to provide a comprehensive analysis. Each of the hydroacoustic and optoelectronic systems is characterised by a different spatial reference system and the method for technical implementation of the measurement. Therefore, the integration of hydrographic data requires that problems in selected...
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Collision‐Aware Routing Using Multi‐Objective Seagull Optimization Algorithm for WSN‐Based IoT
PublikacjaIn recent trends, wireless sensor networks (WSNs) have become popular because of their cost, simple structure, reliability, and developments in the communication field. The Internet of Things (IoT) refers to the interconnection of everyday objects and sharing of information through the Internet. Congestion in networks leads to transmission delays and packet loss and causes wastage of time and energy on recovery. The routing protocols...
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Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning
PublikacjaFollowing the continuous development of the information technology, the concept of dense urban networks has evolved as well. The powerful tools, like machine learning, break new ground in smart network and interface design. In this paper the concept of using deep learning for estimating the radio channel parameters of the LTE (Long Term Evolution) radio interface is presented. It was proved that the deep learning approach provides...
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Real‐Time PPG Signal Conditioning with Long Short‐Term Memory (LSTM) Network for Wearable Devices
PublikacjaThis paper presents an algorithm for real‐time detection of the heart rate measured on a person’s wrist using a wearable device with a photoplethysmographic (PPG) sensor and accelerometer. The proposed algorithm consists of an appropriately trained LSTM network and the Time‐Domain Heart Rate (TDHR) algorithm for peak detection in the PPG waveform. The Long Short‐Term Memory (LSTM) network uses the signals from the accelerometer...
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Automatic Identification System (AIS) Dynamic Data Integrity Monitoring and Trajectory Tracking Based on the Simultaneous Localization and Mapping (SLAM) Process Model
PublikacjaTo enhance the safety of marine navigation, one needs to consider the involvement of the automatic identification system (AIS), an existing system designed for ship-to-ship and shipto- shore communication. Previous research on the quality of AIS parameters revealed problems that the system experiences with sensor data exchange. In coastal areas, littoral AIS does not meet the expectations of operational continuity and system availability,...
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A Method for Underwater Wireless Data Transmission in a Hydroacoustic Channel under NLOS Conditions
PublikacjaWireless data transmission in the hydroacoustic channel under non-line-of-sight (NLOS) propagation conditions, for example, during a wreck penetration, is difficult to implement reliably. This is mostly due to the multipath propagation, which causes a reduction in the quality of data reception. Therefore, in this work an attempt has been made to develop a reliable method of wireless underwater communication test it under the NLOS...
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The influence of the grid density of measurement points on damage detection in an isotropic plate by the use of elastic waves and laser scanning Doppler vibrometry
PublikacjaDamage detection in structural components, especially in mechanical engineering, is an 2 important element of engineering practice. There are many methods of damage detection, in which 3 changes in various parameters caused by the presence of damage are analysed. Recently, methods 4 based on the analysis of changes in dynamic parameters of structures, i.e. frequencies or mode shapes 5 of natural vibrations, as well as changes in...
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The Concept of Using the Decision-Robustness Function in Integrated Navigation Systems
PublikacjaThe diversity and non-uniformity of the positioning systems available in maritime navigation systems often impede the watchkeeping officer in the selection of the appropriate positioning system, in particular, in restricted basins. Thus, it is necessary to introduce a mathematical apparatus to suggest, in an automated manner, which of the available systems should be used at the given moment of a sea trip. Proper selection of the...
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Detecting Lombard Speech Using Deep Learning Approach
PublikacjaRobust Lombard speech-in-noise detecting is challenging. This study proposes a strategy to detect Lombard speech using a machine learning approach for applications such as public address systems that work in near real time. The paper starts with the background concerning the Lombard effect. Then, assumptions of the work performed for Lombard speech detection are outlined. The framework proposed combines convolutional neural networks...
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Behavior of residual current devices at earth fault currents with DC component
PublikacjaLow-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing...
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Non-Contact Monitoring of ECG in the Home Environment—Selecting Optimal Electrode Configuration
PublikacjaCapacitive electrocardiography (cECG) is most often used in wearable or embedded measurement systems. The latter is considered in the paper. An optimal electrocardiographic lead, as an individual feature, was determined based on model studies. It was defined as the possibly highest value of the R-wave amplitude measured on the back of the examined person. The lead configuration was also analyzed in terms of minimizing its susceptibility...
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Wireless Link Selection Methods for Maritime Communication Access Networks—A Deep Learning Approach
PublikacjaIn recent years, we have been witnessing a growing interest in the subject of communication at sea. One of the promising solutions to enable widespread access to data transmission capabilities in coastal waters is the possibility of employing an on-shore wireless access infrastructure. However, such an infrastructure is a heterogeneous one, managed by many independent operators and utilizing a number of different communication...
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Simple Millimeter Wave Identification System Based on 60 GHz Van Atta Arrays
PublikacjaThe paper presents a proof-of-concept of a millimeter-wave identification system based on Van Atta array tags in the 60 GHz band. For interrogation of the tags, a vector network analyzer and a measurement transceiver were employed in alternative test configurations. The design, fabrication and measurements of co- and cross-polarized Van Atta arrays are presented in the paper. They can be treated as simple chipless RFID tags with...
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Novel Vision Monitoring Method Based on Multi Light Points for Space-Time Analysis of Overhead Contact Line Displacements
PublikacjaThe article presents an innovative vision monitoring method of overhead contact line (OCL) displacement, which utilizes a set of LED light points installed along it. A light point is an, LED fed from a battery. Displacements of the LED points, recorded by a camera, are interpreted as a change of OCL shape in time and space. The vision system comprises a camera, properly situated with respect to the OCL, which is capable of capturing...
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Wireless Body Area Network for Preventing Self-Inoculation Transmission of Respiratory Viral Diseases
PublikacjaThis paper proposes an idea of Wireless Body Area Networks (WBANs) based on Bluetooth Low-Energy (BLE) standards to recognize and alarm a gesture of touching the face, and in effect, to prevent self-inoculation of respiratory viral diseases, such as COVID-19 or influenza A, B, or C. The proposed network comprises wireless modules placed in bracelets and a necklace. It relies on the received signal strength indicator (RSSI) measurements...
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Direction of Arrival Estimation Based on Received Signal Strength Using Two-Row Electronically Steerable Parasitic Array Radiator Antenna
PublikacjaIn this paper, we present a novel approach to direction-of-arrival (DoA) estimation using two-row electronically steerable parasitic array radiator (ESPAR) antenna which has 12 passive elements and allows for elevation and azimuth beam switching using a simple microcontroller, relying solely on received signal strength (RSS) values measured at the antenna output port. To this end, we thoroughly investigate all 18 available 3D antenna...
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Wireless Local Area Network Technologies as Communication Solutions for Unmanned Surface Vehicles
PublikacjaAs the number of research activities and practical deployments of unmanned vehicles has shown a rapid growth, topics related to their communication with operator and external infrastructure became of high importance. As a result a trend of employing IP communication for this purpose is emerging and can be expected to bring significant advantages. However, its employment can be expected to be most effective using broadband communication...