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Search results for: PAAS
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A comparison of tribological properties of nanolubricants containing carbon nanotori and additional additives
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Binder-induced surface structure evolution effects on Li-ion battery performance
PublicationA comparative investigation on binder induced chemical and morphological evolution of Li4Ti5O12 electrodes was performed via X-ray photoemission spectroscopy, scanning electron microscopy, and electrochemical measurements. Composite electrodes were obtained using three different binders (PAA, PVdF, and CMC) with 80:10:10 ratio of active material:carbon:binder. The electrochemical performances of the electrodes, were found to be...
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Zarządzanie marką w dobie nadpodaży
PublicationArtykuł poświęcony jest wskazaniu wyzwań stojących przed menedżerami marki wobec nadpodaży marek, produktów i informacji, będącymi pośrednią przyczyną marginalizacji marketingu jako funkcji wielu przedsiębiorstwach o organizacji „silosowej”, gdzie marketing często ograniczany jest do funkcji promocji. Wspomniane okoliczności, zdaniem autorki, mogą prowadzić zarówno do dalszej marginalizacji marketingu w wyniku spadku znaczenia...
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Evaluation of the Influence of Farming Practices and Land Use on Groundwater Resources in a Coastal Multi-Aquifer System in Puck Region (Northern Poland)
PublicationThis study focuses on the modeling of groundwater flow and nitrate transport in a multi-aquifer hydrosystem in northern Poland, adjacent to Puck Bay (Baltic sea). The main goal was to investigate how changes in land use and farming practices may affect groundwater recharge and submarine groundwater discharge (SGD) to the sea and the associated N-NO3 fluxes. An integrated modelling approach has been developed, which couples the...
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New potent steroid sulphatase inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives
PublicationIn the present work, we report a new class of potent steroid sulphatase (STS) inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives. Within the set of new STS inhibitors, 6-(1-(1,2,3-trifluorophenyl)-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate 3L demonstrated the highest activity in the enzymatic assay inhibiting the STS activity to 7.98% at 0.5 µM concentration. Furthermore, to verify...
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Gas Turbine Cycle with External Combustion Chamber for Prosumer and Distributed Energy Systems
PublicationThe use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating...
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Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
PublicationThe paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons...
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Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing
PublicationPart of the heat generated by the shearing of the lubricating film during operation of a hydrodynamic bearing is transferred to the bearing components. In the case of the pad, which is usually fully submerged in the lubricating oil, heat is further transferred at the pad free walls to the oil by convection. This mechanism causes a thermal gradient in a pad and, consequently, its thermal deflection. In large hydrodynamic thrust...
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A simple modification of PCR thermal profile applied to evade persisting contamination
PublicationThe polymerase chain reaction (PCR), one of the most commonly applied methods of diagnostics and molecular biology has a frustrating downside known as the false positive signal or contamination. Several solutions to avoid and to eliminate PCR contaminations have been worked out to date but the implementation of these solutions to laboratory practice may be laborious and time consuming. A simple approach to circumvent the problem...
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Investigation of vortex assisted magnetic deep eutectic solvent based dispersive liquid–liquid microextraction for separation and determination of vanadium from water and food matrices: Multivariate analysis
PublicationA new and simple vortex assisted magnetic deep eutectic solvent dispersive liquid–liquid microextraction procedure (VA-MDES-DLLME) was developed for the determination of vanadium (V) in food and water samples by flame atomic absorption spectrometry (FAAS). In the extraction medium, a bis(acetylpivalylmethane) ethylenediimine (H2APM2en) was used for the complexation of V(V) in sample solution at pH 6. The VA-MDES-DLLME was optimized...
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Affronter la distance et la séparation : l'utilisation des médias sociaux par les migrants dans leurs relations interpersonnelles
PublicationL'augmentation progressive de la mobilité, de l'interconnectivité et de l'instabilité, la transformation du travail et de l'emploi et celle de la communication (Castells, 2010) ont contribué à l’émergence d’une déracinés et séparés de leur foyer évoluent vers de nouvelles perspectives les migrants comme des sujets mobiles et interconnectés qui, grâce aux TIC, peuvent entretenir des relations et des connexions à distance les...
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Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
PublicationObjective. The aim of the study is to investigate the effect of the signal sampling frequency and low-pass filtering on the accuracy of the localisation of the fiducial points of the photoplethysmographic signal (PPG), and thus on the estimation of the blood pressure (i.e. the accuracy of the estimation). Approach. Statistical analysis was performed on 3,799 data samples taken from a publicly available database. Four PPGfiducial...
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New empirical correlations for the viscosity of selected organic phase change materials
PublicationAlthough there are many methods and instruments for measuring viscosity, it is still difficult to determine a reliable value of the dynamic viscosity of complex chemicals such as paraffins and fatty acids. This is due to the complex and heterogeneous structure of these compounds in the case of commercial products. On the other hand, the measuring instrument should be selected very carefully, including its measuring principle and...
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Deep learning techniques for biometric security: A systematic review of presentation attack detection systems
PublicationBiometric technology, including finger vein, fingerprint, iris, and face recognition, is widely used to enhance security in various devices. In the past decade, significant progress has been made in improving biometric sys- tems, thanks to advancements in deep convolutional neural networks (DCNN) and computer vision (CV), along with large-scale training datasets. However, these systems have become targets of various attacks, with...
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Toward the next generation of air quality monitoring: Mercury
PublicationMercury is a global pollutant that is ubiquitous in the environment. Enrichment of mercury in the biosphere as the result of human activities and subsequent production of methylmercury (MeHg) has resulted in elevated concentrations in fish, wildlife and marine mammals globally. Elemental mercury (Hg0) is the most common form of mercury in the atmosphere, and the form that is most readily transported long distances from its emission...
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Effect of CuO and Al 2 O 3 nanoparticle additives on the tribological behavior of fully formulated oils
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Increasing Energy Efficiency of Commercial Vessels: by Using LED Lighting Technology
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The Reliability and Exploitation Analysis Method of the ICT System Power Supply with the Use of Modelling Based on Rough Sets
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Assessment of the Reliability of Wind Farm Devices in the Operation Process
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Assessment of the Impact of Emitted Radiated Interference Generated by a Selected Rail Traction Unit on the Operating Process of Trackside Video Monitoring Systems
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Evaluation of respiration rate and pattern using a portable thermal camera
PublicationThe goal of this paper was to analyze the accuracy of the proposed method for the evaluation of respiration rate and respiration rhythm patterns (e.g. inspiration slope) using the portable and mobile thermal camera module that could be a part of smart glasses. Parameters were analyzed for 12 volunteers in two experiments, when subjects speak and do not speak. The pressure, chest belt was used as a reference measurement method....
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Channel Blockage and Flow Maldistribution during Unsteady Flow in a Model Microchannel Plate heat Exchanger
PublicationThis paper describes the problem of channel blockage as a result of flow maldistribution between the channels of a model mini channel plate heat exchanger consisting of one pass on each leg. Each leg of the heat exchanger contains 51 parallel and rectangular minichannels of four hydraulic diameters namely 461 μm, 571 μm, 750 μm and 823 μm. In addition, a more complex geometry has been investigated where for the sake of breaking...
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Thermodynamic Cycle Concepts for High-Efficiency Power Plants. Part B: Prosumer and Distributed Power Industry
PublicationAn analysis was carried out for different thermodynamic cycles of power plants with air turbines. A new modification of a gas turbine cycle with the combustion chamber at the turbine outlet has been described in the paper. A special air by-pass system of the combustor was applied, and in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with an effective heat exchanger could...
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Methods of trend removal in electrochemical noise data – overview
PublicationIn this paper we shall review popular methods of trend removal from electrochemical noise time records. The basic principles of operation of the six most popular methods are explained. The proposed methods are: high - pass filtering, Moving Average Removal, polynomial detrending, wavelet detrending, Empirical Mode Decomposition and Variational Mode Decomposition. Estimation of trend removal quality...
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Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples
PublicationThe purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination...
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Telekomunikacyjne wsparcie narzędziowe działań zapobiegawczych w zakresie akwizycji, dystrybucji i wymiany informacji w procesie koordynacji i współpracy służb
PublicationPotrzeba prowadzenia efektywnego procesu współpracy służb i organów odpowiedzialnych za bezpieczeństwo narodowe i międzynarodowe wymaga wsparcia ze strony nowoczesnych systemów telekomunikacyjnych, uwarunkowanych ich specjalnym przeznaczeniem. Z uwagi na charakter działań, rozwiązania dla potrzeb koordynacji i współpracy muszą być realizowane jako systemy rozproszone umożliwiające przenoszenie i przetwarzanie informacji multimedialnych,...
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Hey student, are you sharing your knowledge? A cluster typology of knowledge sharing behaviours among students
PublicationKnowledge Sharing (KS) is crucial for all organisations to better face current and future challenges. It is justifiable to assume that after graduation, students will have to face the coming challenges at societal and business levels, and that they will need the adequate KS skills to do so. Though the importance of KS is established, the understanding of how students pass on their knowledge is still fragmented and underdeveloped....
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Value co‐creation (VCC) and value co‐destruction (VCD) via open government data (OGD): Empirical case of Tanzania
PublicationHaving emphasized upon the potential benefits of Open Government Data (OGD) initiatives via value derivation and innovation pursuits of the stakeholders, it falls in place to complement this line of OGD research in the specific case of Tanzania, a developing country, to support the inferences. Specifically, it is important to understand the manner in which OGD VCC-one of the hinges of OGD initiatives- and OGD VCD-a possible fall...
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A new anisotropic bending model for nonlinear shells: Comparison with existing models and isogeometric finite element implementation
PublicationA new nonlinear hyperelastic bending model for shells formulated directly in surface form is presented, and compared to four existing prominent bending models. Through an essential set of elementary nonlinear bending test cases, the membrane and bending stresses of each model are examined analytically. Only the proposed bending model passes all the test cases, while the other bending models either fail or only pass the test cases for...
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Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters
PublicationBuffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more...
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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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Experimentally Aided Operational Virtual Prototyping to Predict Best Clamping Conditions for Face Milling of Large-Size Structures
PublicationVibrations occurring during milling operations are one of the main issues disturbing the pursuit of better efficiency of milling operations and product quality. Even in the case of a stable cutting process, vibration reduction is still an important goal. One of the possible solutions to obtain it is selection of the favorable conditions for clamping the workpiece to the machine table. In this paper, a method for predicting and...
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An analytical approach to determine the health benefits and health risks of consuming berry juices
PublicationFood products composition analysis is a prerequisite for verification of product quality, fulfillment of regulatory enforcements, checking compliance with national and international food standards, contracting specifications, and nutrient labeling requirements and providing quality assurance for use of the product for the supplemen- tation of other foods. These aspects also apply to the berry fruit and berry juice. It also must...
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Od Safony do Sibylli : o twórczości kobiet, które miały odwagę zmieniać świat
Publication"From Sappho to Sibylla. About the women’s research and literary output preserved in the PAS Gdańsk Library early printed books collection (15th-18th c.)" The main purpose of this study was to present women’s research and literary output preserved in the early printed books collection (15th-18th c.) of the PAS Gdańsk Library (PAN Biblioteka Gdańska). The author mentions the phenomenon of women writing and participation in the...
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Possible effects of the 1984 St. Clair River ice jam on bed changes
PublicationThis study examines the possible effect of the record ice jam of 1984 in the St. Clair River on river bed changes and conveyance. Numerical simulations were made to examine the flow and bed shear stresses during the jam formation and release periods. Simulation results indicate that the ice jam in the river did not cause a significant increase in bed shear stress compared to pre- and post-jam open water conditions. The insignificant...
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Diagnostyka analogowych filtrów wielosekcyjnych oparta na klasyfikato-rach neuronowych z dwucentrowymi funkcjami bazowymi
PublicationPrzedmiotem artykułu jest zastosowanie klasyfikatora z dwucentrowymi funkcjami bazowymi do lokalizacji uszkodzeń w wielosekcyjnych torach analogowych elektronicznych systemów wbudowanych sterowanych mikrokontrolerem. Przedstawiono szczegóły procedury pomiarowej oraz metody detekcji i lokalizacji uszkodzeń toru analogowego z wykorzysta-niem klasyfikatora DB zaimplementowanego w postaci algorytmicznej w kodzie programu mikrokontrolera....
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Estimation of respiration rate using an accelerometer and thermal camera in eGlasses
PublicationRespiration rate is a very important vital sign. Different methods of respiration rate measurement or estimation have been developed. However, especially interesting are those that enable remote and unobtrusive monitoring. In this study, we investigated the use of smart glasses for the estimation of respiration rate especially useful for indoors applications. Two methods were analyzed. The first one is based on measurements of...
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Influence of silver-core gold-shell nanoparticle parameters on the variation of surface-enhanced Raman spectra
PublicationThe detection of molecules by surface-enhanced Raman spectroscopy (SERS) is dependent on the nanomaterial used to induce the enhancement effect. This depends on a variety of parameters of the substrate such as the metal used for their creation, their shape, size and size distribution, concentration, as well as the parameters of the solution, such as packing of the nanoparticles, the complexity of the sample, the solvent, etc. It...
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Self-assembly, stability and conductance of amphotericin B channels: bridging the gap between structure and function
PublicationAmphotericin B (AmB), one of the most powerful but also toxic drugs used to treat systemic mycoses, is believed to selectively permeabilize fungal cell membranes to ions in a sterol-dependent manner. Unfortunately, the structure of the biologically active AmB channels has long eluded researchers, obstructing the design of safer alternatives. Here, we investigate the structural and thermodynamic aspects of channel formation, stability,...
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Yerba Mate - A Long but Current History
PublicationBearing in mind the growing interest in Yerba Mate, a comprehensive study has been prepared containing the most important aspects and possibilities of its use. The introduction of the work contains the species characteristics of Yerba Mate, as well as information about the origin and places of cultivation. The next part focuses on the analysis of the composition, pointing to purine alkaloids, polyphenols, saponins, and minerals...
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Toxicity and chemical analyses of airport runoff waters in Poland
PublicationThe aim of this study was to assess the ecotoxicological effects of various compounds in complex airport effluents using a chemical and ecotoxicological integrated strategy. The present work deals with the determination of sum of PCBs, PAHs, pesticides, cations, anions, phenols, anionic, cationic, non-ionic detergents, formaldehyde and metals – as well as TOC and conductivity – in runoff water samples collected from 2009 to 2011...
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Damage Detection Strategies in Structural Health Monitoring of Overhead Power Transmission System
PublicationOverhead power transmission lines, their supporting towers, insulators and other elements create a highly distributed system that is vulnerable to damage. Typical damage scenarios cover cracking of foundation, breakage of insulators, loosening of rivets, as well as cracking and breakage of lines. Such scenarios may result from various factors: groundings, lightning strikes, floods, earthquakes, aeolian vibrations, conductors galloping,...
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Wpływ przewiązek na stateczność prętów dwugałęziowych
PublicationW artykule przedstawiono problem uwzględniania przewiązek w projektowaniu konstrukcji oraz ich wpływ na stateczność elementów konstrukcyjnych. Skupiono się na zaleceniach normowych dotyczących projektowania prętów wielogałęziowych z przewiązkami oraz przedyskutowano zasadność ich używania. W pracy został przedstawiony przykład odcinka pasa górnego mostu kratownicowego złożonego z dwóch kątowników połączonych różną liczbą przewiązek....
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Remote learning among students with and without reading difficulties during the initial stages of the COVID-19 pandemic
PublicationThis article presents the results of a survey on yet under-researched aspects of remote learning and learning difficulties in higher education during the initial stage (March – June 2020) of the COVID-19 pandemic. A total of 2182 students from University of Warsaw in Poland completed a two-part questionnaire regarding academic achievements in the academic year 2019/2020, living conditions and stress related to learning and pandemic,...
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Wyzwania związane z analityką surfaktantów obecnych w różnych elementach środowiska
PublicationSurfaktanty (Surface Active Agents, SAAs) stanowią grupę związków, które ze względu na swoje specyficzne właściwości fizykochemiczne (zdolność do tworzenia micelli, rozpuszczania się w cieczach polarnych i niepolarnych oraz adsorpcji na granicy faz), mogą być stosowane w różnych celach, zarówno w gospodarstwach domowych jak i w przemyśle. Szerokie spektrum zastosowania oraz specyficzne właściwości surfaktantów powodują konieczność...
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Wavelet transform-based approach to defect identification in railway carbon contact strips.
PublicationPantographs of electric rail vehicles are fitted with carbon contact strips, which slide along the contact wire of catenary to provide constant electrical contact. Contact strips are exposed to wear and damages. Using damaged contact strips significantly increases the risk of catenary rupture. Therefore, their technical condition has to be inspected frequently. In previous work a 3D laser scanning system was proposed for recording...
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Advanced oxidation processes for the removal of mono and polycyclic aromatic hydrocarbons – A review
PublicationAromatic hydrocarbons (AHs) are toxic environmental contaminants presented in most of the environmental matrices. Advanced oxidation processes (AOPs) for the removal of AHs in the account of complete mineralization from various environmental matrices have been reviewed in this paper. An in-depth discussion on various AOPs for mono (BTEX) and polyaromatic hydrocarbons (PAHs) and their derivatives is presented. Most of the AOPs were...
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Analysis of GNSS, Hydroacoustic and Optoelectronic Data Integration Methods Used in Hydrography
PublicationThe 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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Design of a Patch Power Divider with Simple Structure and Ultra-Broadband Harmonics Suppression
PublicationThis paper introduces a simple H-shaped patch Wilkinson power divider (WPD), which provides ultra wide harmonics suppression band. The presented WPD designed at 1.8 GHz, and exhibits good performance at the operating bandwidth. In the proposed divider structure, two simple patch low-pass filters (LPFs) are employed at each branch, and three open ended stubs are added at each port. The proposed divider, implemented using the aforementioned...
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Analysis-by-synthesis paradigm evolved into a new concept
PublicationThis work aims at showing how the well-known analysis-by-synthesis paradigm has recently been evolved into a new concept. However, in contrast to the original idea stating that the created sound should not fail to pass the foolproof synthesis test, the recent development is a consequence of the need to create new data. Deep learning models are greedy algorithms requiring a vast amount of data that, in addition, should be correctly...