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QRS Morphology-Based EDR Signal—Factors Determining its Properties
- Piotr Przystup
- Artur Poliński
- Jerzy Wtorek
2022 Pełny tekst IEEE Access
Respiration-induced signals contain a clinically significant information. It could be obtained utilizing both direct and indirect methods. ECG-Derived Respiration (EDR) method is the latter one. However, in this case, two approaches could be distinguished. First one is based on determining changes in the morphology of QRS complexes while the second one is based on the Respiratory Sinus Arrhythmia (RSA) mechanism. The former approach is discussed in the paper. The basic properties of QRS morphology-based EDR signal were evaluated by means of simulations performed using a developed FEM model and appropriate experiments. In effect, basing on changes of the leads’ voltages induced by a heart translation or rotation, or by both mechanisms undergoing simultaneously, the sensitivity-like surfaces and the synthetic EDR signals were obtained. A very good agreement of the experimental and simulation results was achieved. The QRS morphology-based signal’s properties strongly depend on geometrical relation of the used lead to dominating direction of the heart translation, its rotation, and on personal relation between these two mechanisms. The conclusions presented should be taken into account especially when developing or using QRS morphology-based approach in respiratory monitoring systems.
Qualia: About Personal Emotions Representing Temporal Form of Impressions - Implementation Hypothesis and Application Example
- Zdzisław Kowalczuk
- Michał Czubenko
- Marlena Gruba
2022
The aim of this article is to present the new extension of the xEmotion system as a computerized emotional system, part of an Intelligent System of Decision making (ISD) that combines the theories of affective psychology and philosophy of mind. At the same time, the authors try to find a practical impulse or evidence for a general reflection on the treatment of emotions as transitional states, which at some point may lead to the emergence of new emotional qualities ascribed to phenomena (objects or events) perceived by the agent. Since there is a dispute in the literature about the meaning and usefulness of `private' emotions, the article attempts to present in a transparent and technical manner the problem of hypothetical qualia against the background of selected theories of emotions, taking into account the cultural aspect or division. By treating qualia as an expression of individual emotional diversity and learning capacity, qualia can be assigned a quite technical role in modeling the human mind and in implementing autonomous robots and agents.
Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
- Monika Zamłyńska
- Grzegorz Debita
- Przemysław Falkowski-Gilski
2022
Application of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency division multiplexing (OFDM) is widely utilized both in wired and wireless transmission. In this paper we investigate the quality of service (QoS) parameters of a simulated data transmission system, dedicated particularly to audio and video content distribution with orthogonal frequency division multiplexing. The audio research part involves a group of four language sets, namely: American English, British English, German, and Polish, processed using the Ogg Vorbis format. Whereas, in the video part we investigate a set of MPEG-4 video sequences coded at standard resolution of 480 × 270 pixels. Tests were performed under varying network and bandwidth conditions, including signal-to-noise ratio (SNR) and bit error rate (BER). Results of this study may aid parties interested in designing additional backup or supplementary services for portable devices and user terminals, including reliable means of contact, surveillance and monitoring for the Industry 4.0 and Internet of things (IoT) concept.
Quality assessment of low voltage surge arresters
- Leszek Litzbarski
- Marek Olesz
- Stanisław Wojtas
- Michał Winiarski
- Tomasz Klimczuk
- Hubert Glowinski
- Bartłomiej Andrzejewski
2022 Pełny tekst IEEE Access
Users expect reliable operation of the surge arrester during overvoltages, which may originate from a switching process or a lightning discharge. The necessary conditions to guarantee these expectations are: appropriate construction of the surge arrester, its production being maintained in accordance with technical standards, and a positive results of the type test (as well routine and acceptance tests). The recipient, especially when purchasing large quantities of the product, can check the final quality of the product through selective testing of samples from the market in order to find the best supplier. This manuscript specifies the basic parameters of low-voltage (LV) surge arresters of four manufacturers. Basic electrical parameters, i.e. leakage current and varistor voltage (U1mA) before and after the nominal discharge current (In) of 8 µs/20 µs, were determined for 10 randomly selected surge arresters of each manufacturer. Moreover one sample of each varistor batches was aged by fifty 8 µs/20 µs current impulses with In. The obtained results of structural analysis indicate that the crystal structure of the varistor materials changes after ageing process, affecting its electrical properties. The proposed research methodology can be employed as a basis for forecasting the stability of the arrester parameters under operating conditions.
Quality Control of Bacterial Extracellular Vesicles with Total Protein Content Assay, Nanoparticles Tracking Analysis, and Capillary Electrophoresis
- Aleksandra Steć
- Joanna Jońca
- Krzysztof Waleron
- Małgorzata Waleron
- Agata Płoska
- Leszek Kalinowski
- Bartosz Wielgomas
- Szymon Dziomba
2022 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Extracellular vesicles (EVs) were isolated from Pectobacterium zantedeschiae culturing media using direct ultracentrifugation (UC), iodixanol cushion ultracentrifugation (ICUC), and iodixanol density gradient ultracentrifugation (IDGUC) techniques. The isolates were characterized with total protein content assay (bicinchoninic acid assay, BCA), nanoparticles tracking analysis (NTA), and capillary electrophoresis (CE). A satisfactory correlation (R2 > 0.94) between quantitative results obtained with BCA, NTA and CE was achieved only for isolates obtained with the IDGUC. The correlation between protein content and CE was proved to be related to the isolates’ purity. The NTA was found unable to provide reliable information on EVs quantity in samples isolated with UC and ICUC, due to the co-isolated particulate impurities. Moreover, the work reports polysaccharides, used as culturing media components, as a potential source of bias of quantitation with total protein content assay and NTA. The study demonstrates the advantageous selectivity of CE in quality control of EVs and its ability to differentiate subpopulations of EVs of Pectobacterium.
Quality of Cryptocurrency Mining on Previous Generation NVIDIA GTX GPUs
- Jerzy Demkowicz
- Maciej Rutkowski
- Przemysław Falkowski-Gilski
2022
Currently, there is a lot of previous generation NVIDIA GTX graphical processing units (GPUs) available on the market, which were ousted from by next-gen RTX units. Due to this fact, numerous fully-operational devices remain underused, which are available at an affordable price. First, this paper presents an analysis of the cryptocurrency market. Next, in this context, the results of research on the performance of NVIDIA graphics cards with dedicated software as a cryptocurrency mining platform. The research included three hardware platforms: GTX 480 x1, GTX 480 x2 and GTX 760 x1, tested under four cryptocurrencies, namely: Bitcoin, Litecoin, Monero and Ethereum. The custom-build test bench included power consumption as well as the efficiency of mining various digital currencies. Obtained results can aid any investigator interested in designing his own stand as well as configuring the environment.
Quantification of Compatibility Between Polymeric Excipients and Atenolol Using Principal Component Analysis and Hierarchical Cluster Analysis
- Barbara Rojek
- Maria Gazda
- Marek Wesolowski
2022 Pełny tekst AAPS PharmSciTech
An important challenge to overcome in the solid dosage forms technology is the selection of the most biopharmaceutically efficient polymeric excipients. The excipients can be selected, among others, by compatibility studies since incompatibilities between ingredients of the drug formulations adversely affect their bioavailability, stability, efficacy, and safety. Therefore, new, fast, and reliable methods for detecting incompatibility are constantly being sought. Hence, the purpose of this work was to assess the usefulness of a heating, cooling, and reheating differential scanning calorimetry (DSC) program for detecting potential incompatibilities between atenolol, an active pharmaceutical ingredient (API), and polymeric excipients. Hot-stage microscopy (HSM), Fourier transform infrared (FTIR) spectroscopy, and powder X-ray diffraction (PXRD) were used as supporting techniques. Additionally, principal component analysis (PCA) and hierarchical cluster analysis (HCA) served as tools to support the interpretation of the data acquired from the DSC curves and FTIR spectra. As the alterations in the shape of the DSC peak of atenolol which are indicative of incompatibility are visible only on the cooling and reheating curves of the mixtures, the DSC heating–cooling–reheating program was found to be very useful for identifying potential incompatibilities in the binary mixtures of atenolol and polymeric excipients. The melting and recrystallization of atenolol alone and in its mixtures were also confirmed by HSM, while FTIR displayed changes in the spectra of mixtures due to incompatibility. These studies revealed that atenolol is incompatible with hydroxyethylcellulose, hypromellose, and methylcellulose. PXRD measurements at room temperature revealed that the crystallinity of atenolol did not change in these mixtures. However, its crystallinity was reduced in the mixtures previously heated up to 155 °C and then cooled to 25 °C.
Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
- Ireneusz Marzec
- Jerzy Bobiński
2022 Pełny tekst Materials
Results of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity of the results with respect to the material parameters and the specimen geometry is investigated. Three different softening laws are examined. First, a bilinear softening definition is utilized. Then, an exponential curve is taken. Finally, a rational Bezier curve is tested. An ambiguity in choosing material parameters and sof-tening curve definitions is discussed. Numerical results are compared with experimental out-comes recently reported in the literature. Two error measures are defined and used to quantita-tively assess calculated maximum forces (nominal strengths) in comparison with experimental values as a primary criterion. In addition, the force—displacement curves are also analyzed. It is shown that all softening curves produce results consistent with the experimental data. Moreover, with different softening laws assumed, different initial fracture energies should be taken to obtain proper results.
Quantum security and theory of decoherence
- Piotr Mironowicz
2022 Pełny tekst NEW JOURNAL OF PHYSICS
We sketch a relation between two crucial, yet independent, fields in quantum information research, viz. quantum decoherence and quantum cryptography. We investigate here how the standard cryptographic assumption of shielded laboratory, stating that data generated by a secure quantum device remain private unless explicitly published, is disturbed by the einselection mechanism of quantum Darwinism explaining the measurement process by interaction with the external environment. We illustrate the idea with a paradigmatic example of a quantum random number generator compromised by a quantum analog of the Van Eck phreaking. In particular, we derive a trade-off relation between the eavesdropper's guessing probability $\mathrm{P}_{\mathrm{guess}}$ and the collective decoherence factor Γ of the simple form $\mathrm{P}_{\mathrm{guess}} + \Gamma \geqslant 1$.
Quasi-Static Response
- James Underwood
- Erick Alley
- Jerolim Andric
- Dario Boote
- Zhen Gao
- Ad Van Hoeve
- Jasmin Jelovica
- Yasumi Kawamura
- Yooil Kim
- Jianhu Liu
- Sime Malenica
- Heikki Remes
- Asokendu Samanta
- Krzysztof Wołoszyk
- Deqing Yang
2022 Pełny tekst
Concern for the quasi-static response of ship and offshore structures, as required for safety and serviceability assessments. Attention shall be given to uncertainty quantification of quasi-static load and response analysis approaches, and their limitations, including exact and approximate methods for derivation of different acceptance criteria.
Ranking ecosystem services delivered by trees in urban and rural areas
- Patrycja Przewoźna
- Krzysztof Mączka
- Marcin Mielewczyk
- Adam Inglot
- Piotr Matczak
2022 Pełny tekst AMBIO
Policies and strategies for tree management and protection on a national, regional, and local level have not sufficiently considered differences between rural and urban areas. We used expert knowledge to compare rural and urban areas in a case study evaluating the relative importance of ecosystem services (ES) in policy development. The Analytic Hierarchy Process (AHP) and focus group discussions were used to rank 17 ES, representing four classes of services: provisioning, regulating, habitat, and cultural. The results indicated that effective protection strategies, beyond simply increasing general tree cover, should consider specific benefits trees provide to local communities. We discuss the role of objective prioritization of ES delivered by trees in urban and rural areas and their consequences for decision-making processes.
Rapid Design Centering of Multi-Band Antennas Using Knowledge-Based Inverse Models and Response Features
- Michał Kozieł
- Sławomir Kozieł
2022 KNOWLEDGE-BASED SYSTEMS
Accounting for manufacturing tolerances as well as uncertainties concerning operating conditions and material parameters is one of the important yet often neglected aspects of antenna development. Appropriate quantification of uncertainties allows for estimating the fabrication yield but also to carry out robust design (e.g., yield maximization). For reliability reasons, statistical analysis should be executed at the accuracy level of full-wave electromagnetic (EM) simulation. Unfortunately, the associated computational cost is normally unmanageable when using traditional methods, e.g., Monte Carlo (MC) simulation, in a brute force manner. Computationally tractable approaches are based on surrogate modeling techniques, where the fast metamodel is either used to run MC at low cost, or to directly extract statistical moments of the system output (e.g., polynomial chaos expansion). The bottleneck of surrogate-based frameworks is a potentially large number of training data samples necessary to render the surrogate, which may become problematic especially for higher-dimensional parameter spaces. This paper proposes a novel approach to design centering of multi-band antennas, which involves knowledge-based inverse regression models constructed at the level of appropriately-defined response features. Our methodology capitalizes on establishing—in the form of the inverse model—a functional relationship between the feature point coordinates affecting satisfaction of the prescribed design specification and geometry parameters of the antenna under analysis. The inverse model predicts the parameter vectors featuring improved likelihood of fulfilling the requirements under uncertainties. Due to low-dimensionality of the feature space, only a handful of EM analyses is necessary to render the model, which translates into a low cost of the entire design centering procedure. The presented algorithm is demonstrated using three microstrip antennas and favorably compared to several benchmark methods.
Rapid on-line method of wastewater parameters estimation by electronic nose for control and operating wastewater treatment plants toward Green Deal implementation
- Grzegorz Łagód
- Jakub Drewnowski
- Ł. Guz
- Adam Piotrowicz
- Zbigniew Suchorab
- Małgorzata Drewnowska
- Katarzyna Jaromin-Gleń
- Bartosz Szeląg
2022 Desalination and Water Treatment
In order to comply with legal regulations related to wastewater quality, the operational mode of facilities at wastewater treatment plant (WWTP) should be properly adjusted according to parameters of influents, however it is very difficult without frequently performed measurements. Currently there are known many techniques and devices for assesment of wastewater parameters such as chemical oxygen demand, biochemical oxygen demand, total organic carbon, as well as phosphorus and nitrogen compounds. In spite of the far reaching improvements of treatment process automatisation, there still isn’t developed a automatic and fast measuring system of wastewater parameters. Rapid on-line method of wastewater parameters estimation by electronic nose and computer simulations could be recomended as an alternative solution in many WWTPs in comparation with traditional approch. Within this paper the analysis of real-time data obtained from laboratory bioreactor were used to estimate wastewater parameters in order to develop the inexpensive and fast-responding measuring for the WWTPs. The elaborated method enables continuous and relatively low cost monitoring of the wastewater quality even in many key points of operating and control WWTP. In this context, computer simulation support with on-line e-nose measurments could be cheap and useful tool to improve the WWTP efficiency.
Rapid Variable-Resolution Parameter Tuning of Antenna Structures Using Frequency-Based Regularization and Sparse Sensitivity Updates
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2022 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
Geometry parameter tuning is an inherent part of antenna design process. While most often performed in a local sense, it still entails considerable computational expenses when carried out at the level of full-wave electromagnetic (EM) simulation models. Moreover, the optimization outcome may be impaired if good initial design is not available. This paper proposes a novel approach to fast and improved-reliability gradient-based optimization of antenna structures. Our approach employs a frequency-based regularization to facilitate relocation of antenna operating parameters to their target values, which increases the chances of identifying a satisfactory design under challenging conditions (e.g., poor-quality starting point). At the same time, computational efficiency of the tuning process is enhanced through the involvement of variable-resolution EM models, and restricting the finite-differentiation sensitivity updates to selected parameters only. The latter are decided upon based on the analysis of the design relocation between the subsequent iterations of the optimization algorithm. The presented technique is validated using three examples of microstrip antennas optimized under different scenarios (matching improvement, gain enhancement, size reduction). The results demonstrate superior performance in terms of reliability and design quality as compared to conventional gradient-based and derivative-free search procedures. At the same time, a significant speedup is achieved over the frequency-regularization-based procedure not using the acceleration mechanisms.
Rapid Yield Optimization of Miniaturized Microwave Passives by Response Features and Variable-Fidelity EM Simulations
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2022 Pełny tekst Scientific Reports
The operation of high-frequency devices, including microwave passive components, can be impaired by fabrication tolerances but also incomplete knowledge concerning operating conditions (temperature, input power levels) and material parameters (e.g., substrate permittivity). Although the accuracy of manufacturing processes is always limited, the effects of parameter deviations can be accounted for in advance at the design phase through optimization of suitably selected statistical performance figures. Perhaps the most popular one is the yield, which provides a straightforward assessment of the likelihood of fulfilling performance conditions imposed upon the system given the assumed deviations of designable parameters. The latter are typically quantified by means of probability distributions pertinent to the fabrication process. The fundamental obstacle of the yield-driven design is its high computational cost. The primary mitigation approach nowadays is the employment of surrogate modeling methods. Yet, a construction of reliable metamodels becomes problematic for systems featuring a large number of degrees of freedom. Our work proposes a technique for fast yield optimization of microwave passives, which relies on response feature technology as well as variable-fidelity simulation models. Utilization of response features enables efficient handling of issues related to the system response nonlinearities. Meanwhile, the incorporation of variable-resolution simulations allows for accelerating the yield estimation process, which translates into remarkably low overall cost of the optimizing the yield. Our approach is verified with the use of three microstrip couplers. Comprehensive benchmarking demonstrates its superiority in terms of computational efficiency over the state-of-the-art algorithms, whereas reliability is corroborated by electromagnetic (EM)-driven Monte Carlo simulations.
"Raport z wstępnych badań własności stali trudnościeralnej 460HB",. ang "Report on preliminary tests of the properties of wear-resistant steel 460HB"
- Wojciech Kiełczyński
- Maria Głowacka
- Lech Nadolny
- Izydor Jóźwowski
2022
Mikrostrukturę badanej stali trudnościeralnej 460HB stanowi drobnoziarnisty martenzyt odpuszczony, który jest właściwy dla stali konstrukcyjnych niskowęglowych, niskostopowych ulepszonych cieplnie. W przypadku blach grubych, do których zalicza się badana stal, struktura może ulec zaburzeniu, jeżeli w hutniczym procesie wytwórczym wystąpiła niejednorodność odkształcenia plastycznego i w konsekwencji tworzenie się pasm segregacyjnych, jak w przypadku badanej stali. W badanej stali we występujących w strukturze obszarach jasnych pasm, zmierzona mikrotwardość HV0,05 jest znacząco większa w porównaniu do twardości w pasmach ciemnych- średnie wartości: 640 HV0,05 do 485 HV0,05..Powodem jest większy udział twardych węglików, powstałych podczas odpuszczania w pasmach jasnych. Pasmowy rozkład węglików wzdłuż kierunku walcowania jest przyczyną wydatnego obniżenia odporności stali na pękanie oraz niekorzystne zwiększenie anizotropii własności plastycznych blach, wyrażonej przez stosunek energii łamania próbek Charpy V poprzecznych do wzdłużnych, co ma istotne znaczenie podczas procesu spawania. Poziom udarności uzyskany wyniku łamania próbek w badaniach udarności jest nie do zaakceptowania.
Realizacja definiowanego programowo interfejsu radiowego NB-IoT
- Olga Błaszkiewicz
- Jarosław Magiera
- Alicja Olejniczak
- Piotr Rajchowski
- Jarosław Sadowski
- Jacek Stefański
- Krzysztof Cwalina
2022
W niniejszym artykule przedstawiono sposób realizacji definiowanego programo-wo, uniwersalnego interfejsu radiowego do inteligentnych urządzeń IoT (Internet of Things) - DUCH IoT, pracującego zgodnie z międzynarodowymi standardami: LTE (Long Term Evolution) kat. NB1 (Narrowband) oraz LTE kat. NB2. Interfejs radiowy został za-implementowany w formie sprzętowo-programowego, frameworka z konfigurowalnym podziałem realizowanych funkcji pomiędzy częścią sprzętową (zrealizowaną jako moduły IP Core opisane w języku HDL (Hardware Description Language) w sposób niezależny od technologii) a częścią programową frameworka NB1/NB2 (zrealizowaną jako programowe moduły opracowane w języku C/C++), w zależności od możliwości obliczeniowych i za-sobów sprzętowych urządzenia IoT. Przedstawiono architekturę całego interfejsu wraz z modułową strukturą zaprojektowaną do przetwarzania stosu LTE NB-IoT.
Real-time monitoring of the emission of volatile organic compounds from polylactide 3D printing filaments
- Wojciech Wojnowski
- Kaja Kalinowska
- Tomasz Majchrzak
- Bożena Zabiegała
2022 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
Establishing the emission profile of volatile organic compounds generated during fused deposition modeling 3D printing using polymer filaments is important in terms of both understanding the processes taking place during thermal degradation of thermoplastics, and assessing the user's exposure to potentially harmful volatiles. However, obtaining detailed, real-time qualitative and quantitative results poses a challenge. In this paper solid-phase microextraction-gas chromatography-time-of-flight mass spectrometry and proton transfer reaction time-of-flight mass spectrometry were used to identify and monitor the emission of volatiles during thermal degradation of polylactide filaments and during 3D printing. Filaments of two different grades and three colours were used. It was possible to obtain detailed, time- and temperature-resolved emission profiles of the main products of thermal decomposition of lactide and polylactide 3D printing filaments at concentration levels of a few μg/g. This revealed different temperature-dependent emission characteristics of particular volatiles, such as, among others, lactide, acetaldehyde, acetic acid, and 2-butanone between various polylactide 3D printing filaments. This approach can be used to monitor the emission associated with printing with various other types of polymer 3D printing materials.
Real‐Time PPG Signal Conditioning with Long Short‐Term Memory (LSTM) Network for Wearable Devices
- Marek Wójcikowski
2022 Pełny tekst SENSORS
This 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 to improve the shape of the PPG input signal in a time domain that is distorted by body movements. Multiple variants of the LSTM network have been evaluated, including taking their complexity and computational cost into consideration. Adding the LSTM network caused additional computational effort, but the performance results of the whole algorithm are much better, outperforming the other algorithms from the literature.
Rearrangements of the nitrifiers population in an activated sludge system under decreasing solids retention times
- Przemysław Kowal
- Mohamad-Javad Mehrani
- Dominika Sobotka
- Sławomir Ciesielski
- Jacek Mąkinia
2022 Pełny tekst ENVIRONMENTAL RESEARCH
Due to the key role of nitrite in novel nitrogen removal systems, nitrite oxidizing bacteria (NOB) have been receiving increasing attention. In this study, the coexistence and interactions of nitrifying bacteria were explored at decreasing solids retention times (SRTs). Four 5-week washout experiments were carried out in laboratory-scale (V=10 L) sequencing batch reactors (SBRs) with mixed liquor from two full-scale activated sludge systems (continuous flow vs SBR). During the experiments, the SRT was gradually reduced from the initial value of 4.0 d to approximately 1.0 d. The reactors were operated under limited dissolved oxygen conditions (set point of 0.6 mg O2/L) and two process temperatures: 12℃ (winter) and 20℃ (summer). At both temperatures, the progressive SRT reduction was inefficient for the out-selection of both canonical NOB and comammox Nitrospira. However, the dominant NOB switched from Nitrospira to Ca. Nitrotoga, whereas the dominant AOB was always Nitrosomonas. The results of this study are important for optimizing NOB suppression strategies in the novel N removal processes, which are based on nitrite accumulation.