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Search results for: gain
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Low-Cost Multi-Objective Optimization of Antennas By Means Of Generalized Pareto Ranking Bisection Algorithm
PublicationThis paper introduces a generalized Pareto ranking bisection algorithm for low-cost multi-objective design optimization of antenna structures. The algorithm allows for identifying a set of Pareto optimal sets of parameters (that represent the best trade-offs between considered objectives) by iterative partitioning of the intervals connecting previously found designs and executing a Pareto-ranking-based poll search. The initial...
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Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublicationA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
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Social Media in the Fashion Industry. Fundamentals, Strategy and Research Methods
PublicationThis book introduces social network fundamentals in the fashion domain. It addresses the creation of social media marketing plans, highlighting strategic approaches that allow fashion brands to differentiate themselves in the ephemeral and challenging fashion context. Through a variety of academic and professional sources and by sharing the results of their own research, the authors present research methodologies, including netnography,...
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Performance and Energy Aware Training of a Deep Neural Network in a Multi-GPU Environment with Power Capping
PublicationIn this paper we demonstrate that it is possible to obtain considerable improvement of performance and energy aware metrics for training of deep neural networks using a modern parallel multi-GPU system, by enforcing selected, non-default power caps on the GPUs. We measure the power and energy consumption of the whole node using a professional, certified hardware power meter. For a high performance workstation with 8 GPUs, we were...
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Comparison of selected algorithms for scheduling workflow applications with dynamically changing service availability
PublicationThis paper compares the quality and execution times of several algorithms for scheduling service based workflow applications with changeable service availability and parameters. A workflow is defined as an acyclic directed graph with nodes corresponding to tasks and edges to dependencies between tasks. For each task, one out of several available services needs to be chosen and scheduled to minimize the workflow execution time and...
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Entangled rendezvous: a possible application of Bell non-locality for mobile agents on networks
PublicationRendezvous is an old problem of assuring that two or more parties, initially separated, not knowing the position of each other, and not allowed to communicate, are striving to meet without pre-agreement on the meeting point. This problem has been extensively studied in classical computer science and has vivid importance to modern and future applications. Quantum non-locality, like Bell inequality violation, has shown that in many...
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Service-based Resilience via Shared Protection in Mission-critical Embedded Networks
PublicationMission-critical networks, which for example can be found in autonomous cars and avionics, are complex systems with a multitude of interconnected embedded nodes and various service demands. Their resilience against failures and attacks is a crucial property and has to be already considered in their design phase. In this paper, we introduce a novel approach for optimal joint service allocation and routing, leveraging virtualized...
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Fast surrogate-assisted frequency scaling of planar antennas with circular polarisation
PublicationIn this work, the problem of computationally efficient frequency scaling (re-design) of circular polarisation antennas is addressed using surrogate-assisted techniques. The task is challenging and requires the identification of the optimum geometry parameters to enable the operation of the re-designed structure at a selected (required) centre frequency. This involves handling several performance figures such as the antenna gain,...
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A Simple-Topology Compact Broadband Circularly Polarized Antenna With Unidirectional Radiation Pattern
PublicationIn this letter, a geometrically simple, reflector-backed single-point-fed circularly polarized (CP) antenna with unidirectional radiation pattern is presented. The structure comprises a simple coplanar waveguide (CPW) feeding circuit with an open slot etched on one side of the coplanar ground. The enhanced CP bandwidth is obtained by combining the loop mode, the slot mode, and the asymmetrical configuration of the coplanar ground...
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JamesBot - an intelligent agent playing StarCraft II
PublicationThe most popular method for optimizing a certain strategy based on a reward is Reinforcement Learning (RL). Lately, a big challenge for this technique are computer games such as StarCraft II which is a real-time strategy game, created by Blizzard. The main idea of this game is to fight between agents and control objects on the battlefield in order to defeat the enemy. This work concerns creating an autonomous bot using reinforced...
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Portable exhaled breath analyzer employing fluctuation-enhanced gas sensing method in resistive gas sensors
PublicationThis paper presents a portable exhaled breath analyser, developed to detect selected diseases. The set-up employs resistive gas sensors: commercial MEMS sensors and prototype gas sensors made of WO3 gas sensing layers doped with various metal ingredients. The set-up can modulate the gas sensors by applying UV light to induce physical changes of the gas sensing layers. The sensors are placed in a tiny gas chamber of a volume...
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Canonical switched capacitor converters. Comments, complements, and refinements
PublicationSwitched Capacitor Converters (SCC) form useful blocks in low/medium power applications as they are suitable for integration, both as off-chip and on-chip IC realizations. However, the problem with SCC is that their voltage conversion ratio is topology-dependent. By changing the SC circuit configuration, we can gain control over voltage conversion but the available ratio remains of a discrete nature, i.e. it maps into a countable...
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Microgrid Energy Management System
PublicationIn the era of rapid development of "green energy” and storage devices, microgrids implemented in line with the concept of distributed generation can be an effective form of power management. There is a need for an efficient, optimal and reliable control of the combined infrastructure. The article presents a flexible, configurable microgrid's resources control system, which executes the task of meeting the electricity demand of...
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Evolving neural network as a decision support system — Controller for a game of “2048” case study
PublicationThe paper proposes an approach to designing the neuro-genetic self-learning decision support system. The system is based on neural networks being adaptively learned by evolutionary mechanism, forming an evolved neural network. Presented learning algorithm enables for a selection of the neural network structure by establishing or removing of connections between the neurons, and then for a finding the beast suited values of the network...
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Global energy transition: From the main determinants to economic challenges regions
PublicationDynamic global energy transition has been accelerating for the last decade. Interestingly, the energy transition is multidimensional and concerns both the dimensions of technique/ technology and the economic, social, institu-tional, and legal spheres (Shuguang et al., 2022; Tzeremes et al., 2022; Ram-zan et al., 2022; Tzeremes et al., 2022). The literature also points to the signif-icant impact of the digitization of the global...
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Sea spray as a secondary source of chlorinated persistent organic pollutants? - Conclusions from a comparison of seven fresh snowfall events in 2019 and 2021
PublicationSecondary sources of persistent organic pollutants (POPs) gain in importance worldwide as primary sources decline. In this work, we aim to determine whether sea spray may be a secondary source of chlorinated POPs to the terrestrial Arctic, since a similar mechanism was proposed there only for the more water-soluble POPs. To this end, we have determined polychlorinated biphenyls and organochlorine pesticides concentrations in fresh...
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Labeler-hot Detection of EEG Epileptic Transients
PublicationPreventing early progression of epilepsy and sothe severity of seizures requires effective diagnosis. Epileptictransients indicate the ability to develop seizures but humansoverlook such brief events in an electroencephalogram (EEG)what compromises patient treatment. Traditionally, trainingof the EEG event detection algorithms has relied on groundtruth labels, obtained from the consensus...
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Cyclic behavior of FeCoCrNiMn high entropy alloy coatings produced through cold spray
PublicationeCoCrNiMn high entropy alloy powders were employed to produce coatings on carbon steel through high pressure cold spray (at 1100 °C and 7 MPa in temperature and pressure respectively). X-ray diffraction of the sprayed material revealed a dense coating with the retention of the original crystallographic structure. Once splatted, particles revealed high flattening ratio with consequent excellent adhesion of the coating to the substrate....
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A Broadband Circularly Polarized Wide-Slot Antenna with a Miniaturized Footprint
PublicationThis letter presents a novel and simple feeding technique for exciting orthogonal components in a wide-slot antenna. In this technique, a rectangular bracket-shape parasitic strip is placed at the open end of the straight microstrip line to excite the fundamental horizontal and vertical components of the circular polarization (CP). The proposed technique—when employed in conjunction with the asymmetrical geometry of coplanar waveguide...
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Feedline Alterations for Optimization-Based Design of Compact Super-Wideband MIMO Antennas in Parallel Configuration
PublicationThis letter presents a technique for size reduction of wideband multiple-input-multiple-output (MIMO) antennas. Our approach is a two-stage procedure. At the first stage, the antenna structure is modified to improve its impedance matching. This is achieved through incorporation of an n-section tapered feedline, followed by reoptimization of geometry parameters. Reducing the maximum in-band reflection well beyond the acceptance...
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Application 2D Descriptors and Artificial Neural Networks for Beta-Glucosidase Inhibitors Screening
PublicationBeta-glucosidase inhibitors play important medical and biological roles. In this study, simple two-variable artificial neural network (ANN) classification models were developed for beta-glucosidase inhibitors screening. All bioassay data were obtained from the ChEMBL database. The classifiers were generated using 2D molecular descriptors and the data miner tool available in the STATISTICA package (STATISTICA Automated Neural...
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Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources
PublicationA tendency to increase the importance of so called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative...
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Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
PublicationThis communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated...
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Light formed through urban morphology and different organism groups: First findings from a systematic review
PublicationThe prevailing implementation and usage of contemporary lighting technologies and design practices in cities have created over-illuminated built environments. Recent studies indicate that exposure to electric lighting effects formed through spatial characteristics has visual, physiological, and behavioural effects on both humans and non-humans, such as wildlife. In order to gain a better understanding of the impact that electric...
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The effect of heating and fermenting on antioxidant properties of white cabbage
PublicationIt is widely believed that natural antioxidants found in food are significantly lost during processing. Nevertheless, it was recently demonstrated that processed fruits and vegetables may retain their antioxidant activity. In the present work, the changes in the overall antioxidant properties as a consequence of fermentation of cabbage and/or heat treatment of cabbage juices and extracts were studied. Fermentation processes as...
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Technical Engine for Democratization of Modeling, Simulations, and Predictions
PublicationComputational science and engineering play a critical role in advancing both research and daily-life challenges across almost every discipline. As a society, we apply search engines, social media, and se- lected aspects of engineering to improve personal and professional growth. Recently, leveraging such aspects as behavioral model analysis, simulation, big data extraction, and human computation is gain- ing momentum. The nexus...
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Highly-Miniaturized Self-Quadruplexing Antenna Based on Substrate-Integrated Rectangular Cavity
PublicationThis paper introduces a novel self-quadruplexing antenna (SQA) architecture using a substrate-integrated rectangular cavity (SIRC) for compact size, wide-frequency re-designability, and high isolation responses. The proposed SQA is developed by engraving two U-shaped slots (USSs) on the top conductor of the SIRC. The USSs are excited by employing four microstrip feedlines to achieve self-quadruplexing antenna characteristics. The...
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Wireless Link Selection Methods for Maritime Communication Access Networks—A Deep Learning Approach
PublicationIn 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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Molecular dynamics simulations reveal the balance of forces governing the formation of a guanine tetrad—a common structural unit of G-quadruplex DNA
PublicationG-quadruplexes (G4) are nucleic acid conformations of guanine-rich sequences, in which guanines are arranged in the square-planar G-tetrads, stacked on one another. G4 motifs form in vivo and are implicated in regulation of such processes as gene expression and chromosome maintenance. The structure and stability of various G4 topologies were determined experimentally; however, the driving forces for their formation are not fully...
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Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning
PublicationFollowing 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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Low-Voltage Low-Power Filters with Independent ω0 and Q Tuning for Electronic Cochlea Applications
PublicationAn acoustic second-order low-pass filter is proposed for filter banks emulating the operation of a human cochlea. By using a special filter structure and an innovative quality (Q)-factor tuning technique, an independent change of the cutoff frequency (ω0) and the Q-factor with unchanged gain at low frequencies is achieved in this filter. The techniques applied result in a simple filter design with low Q-factor sensitivity to component...
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The Development of a Conceptual Framework for Knowledge Sharing in Agile IT Projects
PublicationOrganizations must adapt their resources to meet the challenges associated with changes in the work environment in order to remain competitive in the information era. Several research findings identify knowledge sharing as a means for an organization to improve its competitiveness. Knowledge sharing can be defined in a variety of ways, but it essentially refers to the exchange of knowledge from an information giver to an information...
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Grid-Forming Operation of Energy-Router Based on Model Predictive Control with Improved Dynamic Performance
PublicationThe focus of this study is on the grid-forming operation of the Energy Router (ER) based on Model Predictive Control (MPC). ER is regarded as a key component of microgrids. It is a converter that interfaces the microgrid (s) with the utility grid. The ER has a multiport structure and bidirectional energy flow control. The ER concept can be implemented in Nearly Zero-Energy Buildings (NZEB) to provide flexible energy control. A...
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Low-Profile Interdigitated UHF RFID Tag Antenna for Metallic Objects
PublicationThis article presents a novel miniature interdigitated ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna that can be placed on metallic objects. The tag structure comprises two horizontal strip lines, each loaded with seven identical open stubs, and an integrated circuit (IC) chip connected directly to the feed lines in the middle of the structure. The perfect match to the IC chip’s impedance is realized...
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Circular polarization diversity implementation for correlation reduction in wideband low-cost multiple-input-multiple-output antenna
PublicationIn this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three parallel coplanar ground planes, and two feedlines in-between. For circular polarization (CP), quasi-loops are created by etching slots on the outermost ground planes. With this...
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Simple 60 GHz Switched Beam Antenna for 5G Millimeter-Wave Applications
PublicationA new 60 GHz band single-input switched beam antenna is proposed for the fifth-generation (5G) millimeter-wave network applications. The presented design is capable of electronically switching the main beam in two different directions via a proposed microstrip-line-to-slotline single-pole dual-throw (SPDT) switch based on commercially available p-i-n diodes. The antenna is fabricated in a low-cost printed circuit board process...
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High-temperature Corrosion of ~ 30 Pct Porous FeCr Stainless Steels in Air: Long-Term Evaluation Up to Breakaway
PublicationIn this work, a long-term (up to 6000 hours) corrosion evaluation of three porous (~ 30 pct of initial porosity) ferritic iron-chromium alloys with different Cr contents (20, 22, and 27 wt pct of Cr) was carried out at 600 C, 700 C, 800 C, and 900 C in air. Mass gain measurements and SEM analyses revealed that at temperatures above 600 C, all alloys exhibit breakaway corrosion, whereas at 600 C, none of the alloys were heavily...
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Mass Spectrometric Identification of 13C-Labeled Metabolites DuringAnaerobic Propanoic Acid Oxidation
PublicationBiowaste digestion is a possibility to gain biogas as a renewable fuel source. However, the anaerobic food chain may be disrupted by, e.g., substrate overload or by inhibitors, leading to the accumulation of volatile fatty acids (VFAs), predominantly of propanoic acid (PA). VFA Accumulation may cause a rapid pH decrease, less biogas production, or even a total inhibition. To maintain high biogas productivity or to prevent a collapse...
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An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
PublicationIn this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and...
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The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells
PublicationThe relatively low photon-to-current conversion efficiency of dye-sensitized solar cells is their major drawback limiting widespread application. Light harvesting, followed by a series of electron transfer processes, is the critical step in photocurrent generation. An in-depth understanding and fine optimization of those processes are crucial to enhance cell performance. In this work, we synthesize two new bi-ruthenium sensitizers...
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Blue applicability grade index (BAGI) and software: a new tool for the evaluation of method practicality
PublicationIn this work, blue applicability grade index (BAGI) is proposed as a new metric tool for evaluating the practicality of an analytical method. BAGI can be considered complementary to the well-established green metrics, and it is mainly focused on the practical aspects of White Analytical Chemistry. This tool evaluates ten main attributes including the type of analysis, the number of analytes that are simultaneously determined, the...
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Improving the prediction of biochar production from various biomass sources through the implementation of eXplainable machine learning approaches
PublicationExamining the game-changing possibilities of explainable machine learning techniques, this study explores the fast-growing area of biochar production prediction. The paper demonstrates how recent advances in sensitivity analysis methodology, optimization of training hyperparameters, and state-of-the-art ensemble techniques have greatly simplified and enhanced the forecasting of biochar output and composition from various biomass...
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Ultra-Compact Self-Quadruplexing Microfluidically Frequency Reconfigurable Slot Antenna Using Half-Mode SIW
PublicationIn this brief, the design of an ultra-compact self-quadruplexing frequency reconfigurable antenna (SQFRA) utilizing a half-mode substrate-integrated waveguide (HMSIW) and microfluidic channels is discussed. Four HMSIW cavities fed by four microstrip lines and slots are used to construct a highly compact antenna. The microstrip feedings to the HMSIW cavities are applied in such a way that the proposed antenna exhibits self-quadruplexing...
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Shape Memory Alloy-Based Fluidically Reconfigurable Metasurfaced Beam Steering Antenna
PublicationA low-cost actuator-based fluidically programmable metasurface (FPMS) antenna is proposed to solve the slow tuning speed problem of the manually fluidic based reconfigurable antennas. The FPMS-based antenna is probe-fed and comprises a 4 × 4 square ring metasurface as a superstrate. Moreover, two shape memory alloy (SMA)-based electrically-controlled actuators are employed in the design for controlling the position of the 3D-printed...
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Mass spectrometric identification of 13C-Labeled metaboloites during anaerobic propanoic acid oxidation
PublicationBiowaste digestion is a possibility to gain biogas as a renewable fuel source. However, the anaerobic food chain may be disrupted by, e.g., substrate overload or by inhibitors, leading to the accumulation of volatile fatty acids (VFAs), predominantly of propanoic acid (PA). VFA Accumulation may cause a rapid pH decrease, less biogas production, or even a total inhibition. To maintain high biogas productivity or to prevent a collapse...
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PERS - QUIET ROAD SURFACE FOR URBAN AREAS
PublicationTraffic noise is one of the most important environmental problems in densely populated urban areas. At low speeds the tyre/road interaction dominates all other sources. It is anticipated that when electric and hybrid vehicles gain dominance in city traffic, the importance of tyre/road noise will still increase as electric engines are much less noisy than combustion engines. On the other hand, electric and hybrid urban vehicles...
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Women's Entrepreneurship in Poland- Opportunities and Barriers According to Young Women Entering the Labour Market
PublicationWomen entrepreneurship is an important issue for both economic and social reasons. However cultural factors have an additional impact. In Poland women represent more than 50% of the population, nonetheless only 35% of people who run their own business are women. Main research questions in the current study were: What are the determinants of the above mentioned imparity? Do young women evaluate themselves as entrepreneurial? Do...
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Ultra-Compact SIRC-Based Self-Triplexing Antenna with High Isolation
PublicationAn ultra-compact self-triplexing antenna realized on a substrate-integrated rectangular cavity (SIRC) is discussed in this study. The proposed structure employs two L-shaped slots and an in-verted U-shaped slot to radiate at three independent operating frequency bands. Three 50-ohm microstrip feed lines are used to excite the radiation in these slots. The operating frequency is individually tuned using the slot size. The slot placement...
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Closer Look at the Uncertainty Estimation in Semantic Segmentation under Distributional Shift
PublicationWhile recent computer vision algorithms achieve impressive performance on many benchmarks, they lack robustness - presented with an image from a different distribution, (e.g. weather or lighting conditions not considered during training), they may produce an erroneous prediction. Therefore, it is desired that such a model will be able to reliably predict its confidence measure. In this work, uncertainty estimation for the task...
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An Innovative Antenna Array with High Inter Element Isolation for Sub-6 GHz 5G MIMO Communication Systems
PublicationA novel technique is shown to improve the isolation between radiators in antenna arrays. The proposed technique suppresses the surface-wave propagation and reduces substrate loss thereby enhancing the overall performance of the array. This is achieved without affecting the antenna’s footprint. The proposed approach is demonstrated on a four-element array for 5G MIMO applications. Each radiating element in the array is constituted...