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Search results for: THRESHOLD CONDITIONS
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Numerical solution of threshold problems in epidemics and population dynamics
PublicationA new algorithm is proposed for the numerical solution of threshold problems in epidemics and population dynamics. These problems are modeled by the delay-differential equations, where the delay function is unknown and has to be determined from the threshold conditions. The new algorithm is based on embedded pair of continuous Runge–Kutta method of order p = 4 and discrete Runge–Kutta method of order q = 3 which is used for the...
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Photoelectron and threshold photoelectron valence spectra of pyridine
Publication. The pyridine molecule has been examined by the means of photoelectron and threshold photoelectron spectroscopies. Ionization energies were determined for both outer and inner valence orbitals and new adiabatic values were also resolved. Vibronic structure associated with several states was assigned mainly to be due to C–C stretches and ring bends. Additionally a Rydberg state converging to 7b2 state was ascribed. The data shown...
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Influence of modulation detection threshold on speech intelligibility
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The current threshold value in potentiodynamic determination of the breakdown potential
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On a threshold induced bias in fish target strength estimation.
PublicationPrzedstawiono statystyczny opis zjawiska wpływu progu rejestracji ech od ryb na estymatę siły celu ryb. Pokazano sposób korekcji wykorzystujący zależności pomiędzy funkcjami rozkładu prawdopodobieństwa poziomu echa i charakterystyki wiązki. Przedstawiono wyniki symulacji.
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Smart Graphite–Cement Composites with Low Percolation Threshold
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Guaranteeing Threshold Attendance of W/WSAN nodes in a reverted security paradigm
PublicationWe consider a Wireline/Wireless Sensor and Actor Network composed of sensor/actor nodes and a data sink/command center (DSCC). Each node controls a generic device that can be in- or out-of-service, corresponding to the ENABLED or DISABLED node state. The node senses the device's intention to change state, and notifies and/or requests the DSCC for authorization to act upon the device. Motivated by requirements for critical infrastructures...
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Enhancing Security of Advanced Metering Infrastructure by Introducing Threshold Attendance Protocol
PublicationThe industry pushes towards smart grid systems in order to resolve current limitations of the unidirectional legacy power grid infrastructure. By introducing Advanced Metering Infrastructure (AMI) as an integral part of the smart grid solution, the utility company obtains an invaluable tool to optimize its network, lower the operational costs, and improve quality of service. Unfortunately, introducing two-way communication poses...
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Mitigation of the Flow Maldistribution in Minichannel and Minigap Heat Exchangers by Introducing Threshold in the Manifolds
PublicationIn the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel rectangular cross-section (1 mm depth and 1 mm width) minichannels and minigap section (1 mm depth and 99 mm width) with rectangular/trapezoidal manifolds in Z-type flow configuration. The author carried out numerical investigation with various mass flowrates, namely 0.05 kg/s, 0.1 kg/s and 0.2 kg/s which...
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Threshold Attendance under Soft-Crash Model: TAG Protocol and Markovian Analysis
PublicationA realistic and systematic network evaluation should subsume an availability model and a failure model. We combine a "hard availability" model we call threshold attendance, whereby a certain minimum number of network elements must be present at any time, with a soft-crash failure model, whereby after experiencing a failure, a network element is still able to function correctly for a while in an emergency mode at a risk of a major...
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Threshold photoelectron studies of isoxazole over the energy range 9.9-30 eV
PublicationThe threshold photoelectron spectrum of the isoxazole molecule, C3H3NO has been measured over the photon energy range 9.9-30 eV with the use of synchrotron radiation. In the 9.9-10.8 eV range, corresponding to photoionization from the highest occupied molecular orbital 3a"(π3), seven well resolved vibrational series have been observed and their modes are tentatively assigned. A strong adiabatic ionization, with an energy of 11.132...
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Effects of laser pulse duration in two-photon vision threshold measurements
PublicationPulsed near-infrared (NIR) light sources can be successfully applied for both imaging and functional testing of the human eye, as published recently1. These two groups of applications have different requirements. For imaging applications, the most preferable is invisible scanning beam while efficiently visible stimulating beam is preferable for functional testing applications. The functional testing of human eye using NIR laser...
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On Optimal Backbone Coloring of Split and Threshold Graphs with Pairwise Disjoint Stars
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Threshold photoelectron spectra of tetrahydrofuran over the energy range 9-29eV
PublicationWykonano pomiary fotoelektronowe widm progowych tetrahydrofuranu C4H8O w zakresie energii fotonów 9-29 eV przy użyciu promieniowania synchrotronowego. Zaobserwowano nowe pasma jonizacyjne w zakresie energii 16-26eV
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Numerical simulation of threshold-crossing problem for random fields of environmental contamination
PublicationCelem artykułu jest analiza szacowania prawdopodobieństwa, że pole losowe zanieczyszczeń nie przekracza pewnej wartości w danej dwuwymiarowej przestrzeni. W analizie wykorzystano metodę modelowania stochastycznego wykorzystując procedurę symulacji warunkowej. Opisany przykład praktycznego zastosowania metody dotyczy pola zanieczyszczenia metalami ciężkimi gruntu w regionie gdańskim.
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Low-threshold lasing eigenmodes of an infinite periodic chain of quantum wires
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Concept of Multicriteria Aid of Choice of Threshold Value IN Biometrical Authentication System
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Determination of percolation threshold in cement composites with expanded graphite by impedance spectroscopy
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EM‐driven constrained miniaturization of antennas using adaptive in‐band reflection acceptance threshold
PublicationNumerical optimization of geometry parameters is a critical stage of the design process of compact antennas. It is also challenging because size reduction is constrained by the necessity of fulfilling imposed electrical performance requirements. Furthermore, full‐wave electromagnetic (EM) analysis needs to be used for reliable performance evaluation of the antenna structure, which is computationally expensive. In this paper, an...
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On delamination threshold loads in low velocity impact on glass-carbon/epoxy composites.
PublicationZbadano możliwości zastąpienia badań udarowych o niskiej energii ze spadającą masą badaniami quasi-statycznymi przy analogicznym obciążeniu próbki dla laminatów epoksydowych wzmocnionych włóknami węglowymi i szklanymi oraz węglowymi. Uzyskano dobrą zgodność wyników obu typów badań , co znajduje potwierdzenie w wynikach innych badaczy.
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Photogrammetric Development Of The Threshold Water At The Dam On The Vistula River In Wloclawek From Unmanned Aerial Vehicles (Uav)
PublicationBarrage in Wloclawek (Poland) was designed by Hydroprojekt and built in the years of 1962 - 1970 as the first stage of the planned Lower Vist ula Cascade. Cascade design assumed the construction of 8 dams in Wyszogr o d, Plock, Wloclawek, Nieszawa (Ciechocinek as an option), Solec Kujawski, Chelmno, Opalen and Tczew. Nieszawa dam was supposed to ensure the maintenance of an adequate free surface...
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Determining manoeuvre detection threshold of GRNN filter in the process of tracking in marine navigational radars
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Dipole-driven dynamics for near-threshold electron/positron interactions with pyrimidinic DNA bases: a path to compound formations
PublicationCalculations are reported for electron and positron scattering from isolated cytosine and thymine, where the two pyrimidinic single-ring DNA bases, in the gas-phase at energies near the elastic threshold, they reveal the special features of the dipole-driven scattering states. All molecules examined exhibit, in fact, supercritical (>1.67 D) permanent dipoles which can therefore also support, below threshold, excited bound compound...
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Determining the noise impact on hearing using psychoacoustical noise dosimeter
PublicationThis research study presents the designed noise dosimeter based on psychoacoustical properties of the human hearing system and, at the same time. evaluation of time and frequency characteristics of noise. The designed noise dosimeter enables assessing temporary threshold shift (TTS) in critical hands in real time. In this way it is possible monitoring the hearing threshold shift continuously for people who stay in the harmful noise...
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Soft X-ray Induced Production of Neutral Fragments in High-Rydberg States at the O 1s Ionization Threshold of the Water Molecule
PublicationDissociation of water molecules after soft X-ray absorption can yield neutral fragments in high-Rydberg (HR) states. We have studied the production of such fragments by field ionization and ion time-of-flight (TOF) spectrometry. Neutral HR fragments are created at all resonances below the O 1s ionization potential (IP) and particularly within 1 eV above the O 1s IP. The latter effect is due to the recapture of the O 1s photoelectrons...
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Effects of lightning and sprites on the ionospheric potential, and threshold effects on sprite initiation, obtained using an analog model of the global atmospheric electric circuit
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Flame retardant epoxy/halloysite nanotubes nanocomposite coatings: Exploring low-concentration threshold for flammability compared to expandable graphite as superior fire retardant
PublicationEpoxy nanocomposites containing halloysite nanotubes (HNTs) were developed and their low-concentration thresholds for thermal stability and flame retardancy were compared with that of epoxy system containing expandable graphite (EG), as a reference with superior flame retardancy. The effects of HNTs and EG on the peak of Heat Release Rate (pHRR), Total Heat Release (THR), and Time-To-Ignition (TTI) of the prepared samples were...
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Evaluation of excessive noise effects on hearing employing psychoacoustic dosimetry
PublicationResearch results regarding the noise impact on hearing applying the concept of the Psychoacoustic Noise Dosimetry (PND) are presented. The general characteristics of the PND algorithm are discussed. Additionally, the results of hearing examinations conducted in the laboratory conditions are shown. The main objective of the research was to determine the time needed for the Temporary Threshold Shift to reverse. The results were used...
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Measured and predicted freeze-thaw days frequencies in climate change conditions in central Poland
PublicationThe rate of progression of geomorphological phenomena is greatly influenced by freeze-thaw processes. In the face of air temperature increasing over the past few decades, a question of the future impact of these processes arises, notably in the temperate and cold climate zones. Using the mean, maximum and minimum daily air temperature data in the period 1951–2018 obtained from three weather stations located in the vicinity of Jeziorsko...
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Adaptive system for recognition of sounds indicating threats to security of people and property employing parallel processing of audio data streams
PublicationA system for recognition of threatening acoustic events employing parallel processing on a supercomputing cluster is featured. The methods for detection, parameterization and classication of acoustic events are introduced. The recognition engine is based onthreshold-based detection with adaptive threshold and Support Vector Machine classifcation. Spectral, temporal and mel-frequency descriptors are used as signal features. The...
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Hydrothermal Cobalt Doping of Titanium Dioxide Nanotubes towards Photoanode Activity Enhancement
PublicationDoping and modification of TiO2 nanotubes were carried out using the hydrothermal method. The introduction of small amounts of cobalt (0.1 at %) into the structure of anatase caused an increase in the absorption of light in the visible spectrum, changes in the position of the flat band potential, a decrease in the threshold potential of water oxidation in the dark, and a significant increase in the anode photocurrent. The material...
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Determination of odour concentration by TD-GC×GC–TOF-MS and field olfactometry techniques
PublicationField olfactometry is one of the sensory techniques used to determine odour concentration, in atmospheric air, directly in emission sources. A two-dimensional gas chromatography with time of flight mass spectrometer (GC×GC–TOF-MS) allows performing the chemical characterization of various groups of chemical compounds, even in complex mixtures. Application of these techniques enabled determination of odour concentration level in...
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Conductive Thermoplastic Polyurethane Nanocomposite Foams Derived from a Cellulose/MWCNTs Aerogel Framework: Simultaneous Enhancement of Piezoresistance, Strength, and Endurance
PublicationHigh conductivity and excellent mechanical properties of composite polymers favors their application as piezoresistive strain sensors. Nonetheless, it is difficult to develop composite polymers with desirable piezoresistance, mechanicaland durable properties. Herein, we developed conductive cellulose/MWCNTs aerogel using the freeze-drying technique. Besides, we explored the application of the highly-sensitive piezoresistive polymer...
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Low-Voltage LDO Regulator Based on Native MOS Transistor with Improved PSR and Fast Response
PublicationIn this paper, a low-voltage low-dropout analog regulator (ALDO) based on a native n-channel MOS transistor is proposed. Application of the native transistor with the threshold voltage close to zero allows elimination of the charge pump in low-voltage regulators using the pass element in a common drain configuration. Such a native pass transistor configuration allows simplification of regulator design and improved performance,...
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Multifaceted Analyses of Four Different Prototype Lightweight Photovoltaic Modules of Novel Structure
PublicationDynamic growth of photovoltaic capacity in Poland encourages many entities to invest in photovoltaic systems. However, in the case of buildings with low roof-bearing capacity it can be problematic or even impossible to mount conventional PV modules due to their relatively high weight. Hence, the use of lightweight PV modules is a potential solution. In this paper four different prototype silicon lightweight modules of novel structure...
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BODIPY‐Perylene Charge Transfer Compounds; Sensitizers for Triplet‐Triplet Annihilation Up‐conversion
PublicationBODIPY heterochromophores, asymmetrically substituted with perylene and/or iodine at the 2 and 6 positions were prepared and investigated as sensitizers for triplet-triplet annihilation up conversion (TTA-UC). Single-crystal X-ray crystallographic analyses show that the torsion angle between BODIPY and perylene units lie between 73.54 and 74.51, though they are not orthogonal. Both compounds show intense, charge transfer absorption...
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CERTIFICATION SYSTEM AS A TOOL FOR IMPROVING THE SAFETY AND SUSTAINABILITY OF SCHOOL-RELATED TRAVELS
PublicationDespite the well-established physical, social, emotional, cognitive, and spatial benefits of active and autonomous school commuting of children and adolescents', many are driven by car. Pilot surveys and field research held in 2019 in 10 Gdansk primary schools confirmed this trend. The article presents a certification system for schools, commissioned by the City of Gdańsk, which is an element of a systemic solution shaping patterns...
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Improving automatic surveillance by sound analysis
PublicationAn automatic surveillance system, based on event detection in the video image can be improved by implementing algorithms for audio analysis. Dangerous or illegal actions are often connected with distinctive sound events like screams or sudden bursts of energy. A method for detection and classification of alarming sound events is presented. Detection is based on the observation of sudden changes in sound level in distinctive sub-bands...
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ThreSpect a program for the determination of the Appearance Energies
Open Research DataDataset presents the “ThreSpect” computer program dedicated to simulating threshold energies of neutral and ionized products generated in the collisions of photons or charged particles with atoms and molecules.
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Efficient Calibration of Cost-Efficient Particulate Matter Sensors Using Machine Learning and Time-Series Alignment
PublicationAtmospheric particulate matter (PM) poses a significant threat to human health, infiltrating the lungs and brain and leading to severe issues such as heart and lung diseases, cancer, and premature death. The main sources of PM pollution are vehicular and industrial emissions, construction and agricultural activities, and natural phenomena such as wildfires. Research underscores the absence of a safe threshold for particulate exposure,...
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SYNAT_MUSIC_GENRE_FV_173
Open Research DataThis is the original dataset containing 51582 music tracks (22 music genres) and 173 element-feature vector [1-6,9]. A collection of more than 50000 music excerpts described with a set of descriptors obtained through the analysis of 30-second mp3 recordings was gathered in a database called SYNAT. The SYNAT database was realized by the Gdansk University...
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The energy consumption during the birch tree sap concentration process using the reverse osmosis system
PublicationBirch tree sap was concentrated by mens of the reversed osmosis technique. The energy consumption in a small-scale pilot apparatus was estimated. The threshold value for the water removal above which the specific energy consumption significantly increased was identified. Below the threshold value the reversed osmosis had low energy demand and could be an attractive method for the production of birch tree sap-based beverages.
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Starter for Voltage Boost Converter to Harvest Thermoelectric Energy for Body-Worn Sensors
PublicationThis paper examines the suitability of selected configurations of ultra-low voltage (ULV) oscilla-tors as starters for a voltage boost converter to harvest energy from a thermoelectric generator (TEG). Important properties of particularly promising configurations, suitable for on-chip imple-mentation are compared. On this basis, an improved oscillator with a low startup voltage and a high output voltage swing is proposed. The applicability...
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A New Adaptive Method for the Extraction of Steel Design Structures from an Integrated Point Cloud
Open Research DataA new automatic and adaptive algorithm for edge extraction from a random point cloud was developed and presented herein. The proposed algorithm was tested using real measurement data. The developed algorithm is able to realistically reduce the amount of redundant data and correctly extract stable edges representing the geometric structures of a studied...
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SYNAT Music Genre Parameters PCA 19
Open Research DataThe dataset contains feature vector after Principal Component Analysis (PCA) performing, so there are 11 music genres and 19-element vector derived from music excerpts. Originally, a feature vector containing 173 elements was conceived in earlier research studies carried out by the team of authors [1-6]. A collection of 52532 music excerpts described...
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SYNAT_PCA_48
Open Research DataThere is a series of datasets containing feature vectors derived from music tracks. The dataset contains 51582 music tracks (22 music genres) and feature vector after Principal Component Analysis (PCA) performing, so there are 48-element vectors derived from music excerpts. Originally, a feature vector containing 173 elements was conceived in earlier...
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SYNAT_PCA_11
Open Research DataThe dataset contains 51582 music tracks (22 music genres) and feature vector after Principal Component Analysis (PCA) performing, so there are 11-element vectors derived from music excerpts. Originally, a feature vector containing 173 elements was conceived in earlier research studies carried out by the team of authors [1-6]. A collection of more than...
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Tripping limitations of residual current devices in photovoltaic installations
PublicationIn electrical installations with photovoltaic sources of energy, earth fault current may comprise alternating current component and direct current component. The waveform shape of this earth fault current mainly depends on the point of the fault and the properties of a photovoltaic power electronics converter. The waveform shape of the current influences operation of protection devices, especially tripping threshold of residual...
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The power of silence? opinion contagion and the surprise of the polish 2005 parlamentary and presidential elections
PublicationThis paper investigates opinion contagion in collective behaviour using threshold model (Granovetter (1978), Krassa(1988)). The theoretical background is the spiral of silence concept developed by Noelle-Neumann (1974), arguing that people only assert their opinions if they perceive a minimal support from a relevant proportion of others. We apply the model to explain the dispersion between pre-elections preferences and the final...
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...