Rok 2020

• Implementation of spatial/polarization diversity for improved-performance circularly polarized multiple-input-multiple-output ultra-wideband antenna

  Publikacja

  • U. Ullah
  • I. Mabrouk
  • S. Kozieł
  • M. Al-hasan

  - IEEE Access - Rok 2020

  In this paper, spatial and polarization diversities are simultaneously implemented in an ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna to reduce the correlation between the parallel-placed radiators. The keystone of the antenna is systematically modified coplanar ground planes that enable excitation of circular polarization (CP). To realize one sense of circular polarization as well as ultra-wideband operation,...

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• Improved-Efficacy Optimization of Compact Microwave Passives by Means of Frequency-Related Regularization

  Publikacja

  • S. Kozieł
  • A. Pietrenko-Dąbrowska
  • H. Alhasan

  - IEEE Access - Rok 2020

  Electromagnetic (EM)-driven optimization is an important part of microwave design, especially for miniaturized components where the cross-coupling effects in tightly arranged layouts make traditional (e.g., equivalent network) representations grossly inaccurate. Efficient parameter tuning requires reasonably good initial designs, which are difficult to be rendered for newly developed structures or when re-design for different operating...

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• Improving the Quality of Magnetic Signature Reproduction by Increasing Flexibility of Multi-Dipole Model Structure and Enriching Measurement Information

  Publikacja

  • J. Tarnawski
  • A. Cichocki
  • T. A. Rutkowski (dawniej: T. Rutkowski)
  • K. Buszman
  • M. Wołoszyn

  - IEEE Access - Rok 2020

  The paper presents the construction of a multi-dipole model that allows reproducing magneticsignatures of ferromagnetic objects. The virtual object used in the paper is an ellipsoid, which is the sourceof synthetic data. To make the situation more realistic, noise is added to the synthetic data. Two significantimprovements compared to previous work are presented. Three-axial magnetometers are introduced insteadof uniaxial magnetometers....

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• Neural Architecture Search for Skin Lesion Classification

  Publikacja

  • A. Kwasigroch
  • M. Grochowski
  • A. Mikołajczyk-Bareła (dawniej: A. Mikołajczyk)

  - IEEE Access - Rok 2020

  Deep neural networks have achieved great success in many domains. However, successful deployment of such systems is determined by proper manual selection of the neural architecture. This is a tedious and time-consuming process that requires expert knowledge. Different tasks need very different architectures to obtain satisfactory results. The group of methods called the neural architecture search (NAS) helps to find effective architecture...

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• On Computationally-Efficient Reference Design Acquisition for Reduced-Cost Constrained Modeling and Re-Design of Compact Microwave Passives

  Publikacja

  • S. Kozieł
  • A. Pietrenko-Dąbrowska

  - IEEE Access - Rok 2020

  Full-wave electromagnetic (EM) analysis has been playing a major role in the design of microwave components for the last few decades. In particular, EM tools allow for accurate evaluation of electrical performance of miniaturized structures where strong cross-coupling effects cannot be adequately quantified using equivalent network models. However, EM-based design procedures (parametric optimization, statistical analysis) generate...

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• On Inadequacy of Sequential Design of Experiments for Performance-Driven Surrogate Modeling of Antenna Input Characteristics

  Publikacja

  • A. Pietrenko-Dąbrowska
  • S. Kozieł

  - IEEE Access - Rok 2020

  Design of contemporary antennas necessarily involves electromagnetic (EM) simulation tools. Their employment is imperative to ensure evaluation reliability but also to carry out the design process itself, especially, the adjustment of antenna dimensions. For the latter, traditionally used parameter sweeping is more and more often replaced by rigorous numerical optimization, which entails considerable computational expenses, sometimes...

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• On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks

  Publikacja

  • M. Laskowski
  • S. J. Ambroziak (dawniej: S. Ambroziak)
  • L. M. Correia
  • K. Świder

  - IEEE Access - Rok 2020

  In this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...

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• Quasi-Global Optimization of Antenna Structures Using Principal Components and Affine Subspace-Spanned Surrogates

  Publikacja

  • J. Tomasson
  • S. Kozieł
  • A. Pietrenko-Dąbrowska

  - IEEE Access - Rok 2020

  Parametric optimization is a mandatory step in the design of contemporary antenna structures. Conceptual development can only provide rough initial designs that have to be further tuned, often extensively. Given the topological complexity of modern antennas, the design closure necessarily involves full-wave electromagnetic (EM) simulations and—in many cases—global search procedures. Both factors make antenna optimization a computationally...

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• Rapid optimization of compact microwave passives using kriging surrogates and iterative correction

  Publikacja

  • S. Kozieł
  • A. Pietrenko-Dąbrowska

  - IEEE Access - Rok 2020

  Design of contemporary microwave components is—in a large part—based on full-wave electromagnetic (EM) simulation tools. The primary reasons for this include reliability and versatility of EM analysis. In fact, for many microwave structures, notably compact components, EM-driven parameter tuning is virtually imperative because traditional models (analytical or network equivalents) are unable to account for the cross-coupling effects,...

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• Recent advances in high-frequency modeling by means of domain confinement and nested kriging

  Publikacja

  • S. Kozieł
  • A. Pietrenko-Dąbrowska

  - IEEE Access - Rok 2020

  Development of modern high-frequency components and circuits is heavily based on full-wave electromagnetic (EM) simulation tools. Some phenomena, although important from the point of view of the system performance, e.g., EM cross-coupling effects, feed radiation in antenna arrays, substrate anisotropy, cannot be adequately accounted for using simpler means such as equivalent network representations. Consequently, the involvement...

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• Reinforced Secure Gossiping Against DoS Attacks in Post-Disaster Scenarios

  Publikacja

  • C. Esposito
  • Z. Zhao
  • J. Rak

  - IEEE Access - Rok 2020

  During and after a disaster, the perceived quality of communication networks often becomes remarkably degraded with an increased ratio of packet losses due to physical damages of the networking equipment, disturbance to the radio frequency signals, continuous reconfiguration of the routing tables, or sudden spikes of the network traffic, e.g., caused by the increased user activity in a post-disaster period. Several techniques have...

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• Sensor Position Estimation Method for IoT Using Mobile Reference Node

  Publikacja

  • J. Stefański
  • J. Sadowski

  - IEEE Access - Rok 2020

  The paper proposes an innovative method of locating objects for the Internet of Things (IoT). The proposed method allows the position of a fixed measuring sensor (MS) to be estimated using one mobile base station with a known position moving around the MS. The mathematical analysis of the method, and three algorithms — Newton’s (NA), gradient descent (GD) and genetic (GA) — for solving the system of non-linear positional equations...

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• Ship Collision Risk Assessment Based on Collision Detection Algorithm

  Publikacja

  • D. Liu
  • G. Shi

  - IEEE Access - Rok 2020

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• Simulation-Driven Antenna Modeling by Means of Response Features and Confined Domains of Reduced Dimensionality

  Publikacja

  • A. Pietrenko-Dąbrowska
  • S. Kozieł

  - IEEE Access - Rok 2020

  In recent years, the employment of full-wave electromagnetic (EM) simulation tools has become imperative in the antenna design mainly for reliability reasons. While the CPU cost of a single simulation is rarely an issue, the computational overhead associated with EM-driven tasks that require massive EM analyses may become a serious bottleneck. A widely used approach to lessen this cost is the employment of surrogate models, especially...

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• Stress Monitoring System for Individuals with Autism Spectrum Disorders

  Publikacja

  • M. T. Tomczak (dawniej: M. Tomczak)
  • M. Wójcikowski
  • B. Pankiewicz
  • J. Łubiński
  • J. Majchrowicz
  • D. Majchrowicz
  • A. Walasiewicz
  • T. Kiliński
  • M. Szczerska

  - IEEE Access - Rok 2020

  In this article, a stress monitoring system tailored for individuals with Autism Spectrum Disorders (ASD) and developed for the educational institution is presented. People with ASD face problems with effective stress management due to their high self-perceived levels of stress, poor ability to cope with it, and dificulties with the accurate detection of the source of stress. Consistently, being able to measure stress appears to...

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• The Impact of Lexicon Adaptation on the Emotion Mining From Software Engineering Artifacts

  Publikacja

  • M. Wróbel

  - IEEE Access - Rok 2020

  Sentiment analysis and emotion mining techniques are increasingly being used in the field of software engineering. However, the experiments conducted so far have not yielded high accuracy results. Researchers indicate a lack of adaptation of the methods of emotion mining to the specific context of the domain as the main cause of this situation. The article describes research aimed at examining whether the adaptation of the lexicon...

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• Toward Robust Pedestrian Detection With Data Augmentation

  Publikacja

  • S. Cygert
  • A. Czyżewski

  - IEEE Access - Rok 2020

  In this article, the problem of creating a safe pedestrian detection model that can operate in the real world is tackled. While recent advances have led to significantly improved detection accuracy on various benchmarks, existing deep learning models are vulnerable to invisible to the human eye changes in the input image which raises concerns about its safety. A popular and simple technique for improving robustness is using data...

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• Usability of mobile applications: a systematic literature study

  Publikacja

  • P. Weichbroth

  - IEEE Access - Rok 2020

  Since the release of the first mobile devices, the usability of on-board applications has been the concern not only of software vendors but hardware manufacturers as well. The academia community later willingly joined the discussion on usability in terms of theory and empirical measurement, having experience and knowledge in desktop settings. At first sight, such a background should guarantee a solid foundation to conduct research...

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Rok 2019

• An Enhanced Reduced Basis Method for Wideband Finite Element Method Simulations

  Publikacja

  • D. Szypulski
  • G. Fotyga
  • M. Mrozowski

  - IEEE Access - Rok 2019

  In this paper, we present a novel strategy for selecting expansion points in the reduced basis method. A single computation of the error estimator is used to select a few expansion points in the multi-parameter space simultaneously. The number of selected points is determined adaptively, based on the accuracy of the current reduced model. The reliability and efficiency of this proposed approach are illustrated by numerical tests...

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• Application of Barycentric Coordinates in Space Vector PWM Computations

  Publikacja

  • P. Szczepankowski
  • J. Nieznański

  - IEEE Access - Rok 2019

  This paper proposes the use of barycentric coordinates in the development and implementationof space-vector pulse-width modulation (SVPWM) methods, especially for inverters with deformed space-vector diagrams. The proposed approach is capable of explicit calculation of vector duty cycles, independentof whether they assume ideal positions or are displaced due to the DC-link voltage imbalance. The use ofbarycentric coordinates also...

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