Filtry
wszystkich: 1925
-
Katalog
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: parametric spectrum estimation
-
Brain perfusion imaging with the use of parametric modelling basing on DSC-MRI data
PublikacjaW pracy do estymacji parametrów perfuzji mózgu: przepływu krwi mózgowej (cerebral blood flow, CBF), objętości krwi mózgowej (cerebral blood volume, CBV) oraz średniego czasu przejścia (mean transit time, MTT) wykorzystano pomiary DSC-MRI (Dynamic Susceptibility Contrast Magnetic Resonance Imaging). W modelowaniu danych MRI zastoswoano model trzykompartmentowy. Przedstawiono i porównano dwa podejścia do identyfikacji modelu różniące...
-
Identification of quasi-periodically varying systems using the combined nonparametric/parametric approach
PublikacjaW artykule przedstawiono tzw. uogólniony periodogram pozawlający na określenie liczby funkcji bazowych opisujących obiekt o parametrach zmieniających się w sposób pseudookresowy. Pokazano w jaki sposób określić wartości początkowe dla algorytmów opartych na metodzie funkcji bazowych na jego podstawie. Skuteczność zaproponowanych metod zilustrowano przykładami.
-
Computing methods for fast and precise body surface area estimation of selected body parts
PublikacjaCurrently used body surface area (BSA) formulas give satisfactory results only for individuals with typical physique, while for elderly, obese or anorectic people accurate results cannot be expected. Particularly noteworthy are the results for individuals with severe obesity (body-mass index greater than 35 kg/m2), for which BSA estimation errors reached 80%. The main goal of our study is the development of precise BSA models for...
-
Detecting Apples in the Wild: Potential for Harvest Quantity Estimation
PublikacjaKnowing the exact number of fruits and trees helps farmers to make better decisions in their orchard production management. The current practice of crop estimation practice often involves manual counting of fruits (before harvesting), which is an extremely time-consuming and costly process. Additionally, this is not practicable for large orchards. Thanks to the changes that have taken place in recent years in the field of image...
-
Estimation of object size in the calibrated camera image = Estymacja rozmiaru obiektów w obrazach ze skalibrowanej kamery
PublikacjaIn the paper, a method of estimation of the physical sizes of the objects tracked by the camera is presented. First, the camera is calibrated, then the proposed algorithm is used to estimate the real width and height of the tracked moving objects. The results of size estimation are then used for classification of the moving objects. Two methods of camera calibration are compared, test results are presented and discussed. The proposed...
-
Efficient RSS-Based DoA Estimation for ESPAR Antennas Using Multiplane SDR Calibration Approach
PublikacjaIn this paper, we have introduced a new method to improve overall efficiency of direction-of-arrival (DoA) estimation scheme relying on received signal strength (RSS) values measured at the output port of electronically steerable parasitic array radiator (ESPAR) antenna. The proposed approach uses software-defined radio (SDR) setup and power pattern cross-correlation (PPCC) estimator involving multiple calibration planes. By placing...
-
Dynamic analysis of the impact of the wind spectrum according to the theory of Davenport for lightweight structures of the roof in sports hall Czyzyna in Cracow.
PublikacjaThe main aim of this analysis is to characterize numerical simulations connected with modeling dynamic influence of wind on the lightweight structures of the roof in sports hall – “Czyżyna”. This hall is built in Cracow. The article also involves the proposals of the solutions connected with dynamic influence of the wind – Davenport’s method has been used. These proposals have not been taken into consideration at the detailed engineering...
-
Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublikacjaNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
-
Estimation of DC motor parameters using a simple CMOS camera
PublikacjaDifferent components of control systems for mobile robots are based on dynamic models. In low-cost solutions such a robot is wheeled and equipped with DC motors, which have to be included in the model of the robot. The model is fairly simple but determination of its parameters needs not to be easy. For instance, DC motor parameters are typically identified indirectly using suitable measurements, concerning engine voltage, current,...
-
Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublikacjaTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
-
Towards rainfall interception capacity estimation using ALS LiDAR data
PublikacjaIn this study we develop a spatial model for interception capacity of vegetation based on LiDAR data. The study is conducted in the natural wetland river valley dominated meadows, reeds and small bushes. The multiple regression model was chosen to relate the field measurements of interception capacity and LiDAR statistics at 2m grid. The optimal model was chosen by stepwise selection and further manual variables selection resulting...
-
Rapid Multi-band Patch Antenna Yield Estimation Using Polynomial Chaos-Kriging
PublikacjaYield estimation of antenna systems is important to check their robustness with respect to the uncertain sources. Since the Monte Carlo sampling-based real physics simulation model evaluations are computationally intensive, this work proposes the polynomial chaos-Kriging (PC-Kriging) metamodeling technique for fast yield estimation. PC-Kriging integrates the polynomial chaos expansion (PCE) as the trend function of Kriging metamodel...
-
Variable-fidelity response feature surrogates for accelerated statistical analysis and yield estimation of compact microwave components
PublikacjaAccounting for manufacturing tolerances is an essential part of a reliable microwave design process. Yet, quantification of geometry and/or material parameter uncertainties is challenging at the level of full-wave electromagnetic (EM) simulation models. This is due to inherently high cost of EM analysis and massive simulations necessary to conduct the statistical analysis. Here, a low-cost and accurate yield estimation procedure...
-
Thermal Image Processing for Respiratory Estimation from Cubical Data with Expandable Depth
PublikacjaAs healthcare costs continue to rise, finding affordable and non-invasive ways to monitor vital signs is increasingly important. One of the key metrics for assessing overall health and identifying potential issues early on is respiratory rate (RR). Most of the existing methods require multiple steps that consist of image and signal processing. This might be difficult to deploy on edge devices that often do not have specialized...
-
Instrument detection and pose estimation with rigid part mixtures model in video-assisted surgeries
PublikacjaLocalizing instrument parts in video-assisted surgeries is an attractive and open computer vision problem. A working algorithm would immediately find applications in computer-aided interventions in the operating theater. Knowing the location of tool parts could help virtually augment visual faculty of surgeons, assess skills of novice surgeons, and increase autonomy of surgical robots. A surgical tool varies in appearance due to...
-
On practical problems in estimation of antioxidant activity of compounds by DPPH method (Problems in estimation of antioxidant activity)
Publikacja -
Accelerated impedance spectrum measurement via multisine perturbationand digital filter banks
PublikacjaPrzedstawiono przyspieszoną metodę pomiaru widma impedancyjnego, zorientowaną na pomiary jakości powłok przeciwkorozyjnych, modelowanych liniowymi obwodami zastępczymi. Metoda polega na pobudzeniu układu wielosinusoidalnym sygnałem popudzającym oraz analizie pobudzenia i odpowiedzi obiektu przez bank filtrów cyfrowych. Przedstawiono podstawy teoretyczne metody oraz propozycję metodologii pomiaru. Przeanalizowano wyniki symulacji...
-
Application of Pierson-Moskowitz wave spectrum to solution differential equations of multihull vessel
PublikacjaMotion of a dynamic system can be generated by different external or internal factors. At mathematical modelling external excitation factors of the most significant effect on the system, are selected. Such external factors are usually called excitations. Response of the system to given excitations is mathematically characterized by a definite transformation called operator of a system. For a broad class of dynamic systems the...
-
Spectrum of Bacterial Pathogens from Urinary Infections Associated with Struvite and Metabolic Stones
Publikacja -
<title>Spectrum analysis of measuring signals in sensor circuits with frequency outputs</title>
Publikacja -
Parametric impulsive noise detector for corrupted audio signals based on hidden Markow model
PublikacjaThe paper addresses the problem of impulsive noise detection for audio signals. A structure of threshold parameter detectors using modelingof signals was introduced. the algorithm of the noise detection, based on discrete-time hidden Markow model (HMM)of whitened audio signal is elaborated
-
A probabilistic-driven framework for enhanced corrosion estimation of ship structural components
PublikacjaThe work proposes a probabilistic-driven framework for enhanced corrosion estimation of ship structural components using Bayesian inference and limited measurement data. The new approach for modelling measurement uncertainty is proposed based on the results of previous corrosion tests that incorporate the non-uniform character of the corroded surface of structural components. The proposed framework's basic features are outlined,...
-
A method for preliminary estimation of the length of midship body block to be inserted during ship’s conversion
PublikacjaThe paper presents a method for preliminary estimation of the length of the midship body block, which inserted in the original hull, increases the deadweight of the ship in line with a required quantity. The method may be useful for establishing the scope of conversion to better adjust the ship for transportation tasks. The problem is formulated by using a mathematical model so selected that its solution, under set of assumptions,...
-
Estimation of the amplitude of the signal for the active optical gesture sensor with sparse detectors
PublikacjaIn this paper we deal with the problem of precise gesture recognition for the active optical proximity sensor with sparse 8 photodiodes. We particularly focus on developing the method of estimating the real, usually not observable, maximum signal value representing maximum intensity of light reflected from an obstacle present in the front of the sensor. Different configurations of the fingers were used as an obstacle. The Monte Carlo...
-
Rigid finite elements and multibody modelling used in estimation and reduction of rod vibrations
PublikacjaIn the paper, a mechanical set composed of a robot (manipulator) and of an elastic beam is considered. The beam is fixed to the top of the robot structure. In most of the similar cases, undesired vibrations can be excited in the beam. They are especially significant, when dynamics in the robot braking period is examined. In the paper, estimation and modification of length of the braking period is proposed, in order to reduce the...
-
Performance of the Direct Sequence Spread Spectrum Underwater Acoustic Communication System with Differential Detection in Strong Multipath Propagation Conditions
PublikacjaThe underwater acoustic communication (UAC) operating in very shallow-water should ensure reliable transmission in conditions of strong multipath propagation, significantly disturbing the received signal. One of the techniques to achieve this goal is the direct sequence spread spectrum (DSSS) technique, which consists in binary phase shift keying (BPSK) according to a pseudo-random spreading sequence. This paper describes the DSSS...
-
Comparison of Doppler Effect Estimation Methods for MFSK Transmission in Multipath Hydroacoustic Channel
PublikacjaUnderwater wireless communication remains a challenging topic, particularly for applications such as wreck penetration where multipath and Doppler effects are very intense. These effects are becoming even more difficult to mitigate for fast data transmission systems that utilize wideband signals. Due to the low propagation speed of acoustic wave in the water, there is a significant difference between the Doppler shift for lower...
-
ON ESTIMATION OF OCCUPANT SAFETY IN VEHICULAR CRASHES INTO ROADSIDE OBSTACLES USING NON-LINEAR DYNAMIC ANALYSIS
PublikacjaThe article describes a comparison of two general methods of occupants safety estimation based on a numerical examples. The so-called direct method is mainly based on the Head Injury Criterion of a crash test dummy in a vehicle with passive safety system while the indirect method uses a European standards approach to estimate impact severity level. Numerical simulations in LS-DYNA have been conducted.
-
Iterative‐recursive estimation of parameters of regression models with resistance to outliers on practical examples
PublikacjaHere, identification of processes and systems in the sense of the least sum of absolute values is taken into consideration. The respective absolute value estimators are recognised as exceptionally insensitive to large measurement faults or other defects in the processed data, whereas the classical least squares procedure appears to be completely impractical for processing the data contaminated with such parasitic distortions. Since...
-
RSS-Based DoA Estimation Using ESPAR Antenna for V2X Applications in 802.11p Frequency Band
PublikacjaIn this paper, we have proposed direction-of arrival (DoA) estimation of incoming signals for V2X applications in 802. 11p frequency band, based on recording of received signal strength (RSS) at electronically steerable parasitic array radiator (ESPAR) antenna's output port. The motivation of the work was to prove that ESPAR antenna used to increase connectivity and security in V2X communication can...
-
Using Disparity Map for Moving Object Position Estimation in Pan Tilt Camera Images
PublikacjaIn this paper we present the algorithm for rapid moving object position estimation in an images acquired from pan tilt camera. Detection of a moving object in a image acquired from a moving camera might be quite challenging. Standard methods that relay on analyzing two consecutive frames are not applicable due to the changing background. To overtake this problem we decided to evaluate the possibility of calculating a disparity...
-
New approaches to cutting resistance estimation of wood cutting process with circular-saw blades
PublikacjaTheoretical and experimental determination of values of cutting resistance belongs to the basic and simultaneously the most developed field of mechanics of this process. Energetic effects of wood sawing process are mainly calculated on the basis of the specific cutting resistance which, in wood cutting, is a function on a lot of factors. In this paper new method for calculation of cutting resistance is described. The latter method...
-
Identification of nonstationary multivariate autoregressive processes– Comparison of competitive and collaborative strategies for joint selection of estimation bandwidth and model order
PublikacjaThe problem of identification of multivariate autoregressive processes (systems or signals) with unknown and possibly time-varying model order and time-varying rate of parameter variation is considered and solved using parallel estimation approach. Under this approach, several local estimation algorithms, with different order and bandwidth settings, are run simultaneously and compared based on their predictive performance. First,...
-
A novel method of local chirp-rate estimation of LFM chirp signals in the time-frequency domain
PublikacjaIn the paper, novel dynamic representations of a complex signal in the time-frequency domain are introduced. The proposed approach is based on using the gradient of the short-time Fourier transform complex phase. A channelized instantaneous complex frequency (CICF) and a complex local group delay (CLGD) are included in the presented signal representations. An application of the newly-introduced distributions is demonstrated by...
-
On the concept of estimation memory in adaptive filtering.
PublikacjaArtykuł przedstawia i omawia pojęcie pamięci estymacji, pozwalające na obiektywne porównanie właściwości śledzących różnych algorytmów adaptacyjnych filtracji.
-
Modelling an accelerometer for robot position estimation
PublikacjaThe article describes a new model of a MEMS accelerometer for usage in inertial measurement units (IMU). Such units allow to measure orientation and location of the sensor/system and therefore can be applied for systems positioning. The main purpose of the paper is to model pertinent accelerometer functions substantial in determination of the location of the sensor by means of double integration of acceleration. The model takes...
-
Shift-Msplit* Estimation in Deformation Analyses
Publikacja -
Estimation of vehicle operational fuel consumption
PublikacjaW pracy przedstawiono metodę umożliwiającą wyznaczenie referencyjnego zużycia paliwa dla zarejestrowanych warunków eksploatacji. Warunki eksploatacji opisane są rozkładem energochłonności jednostkowej, która obejmuje zarówno wpływ warunków zewnętrznych jak również styl jazdy kierowcy. W pracy przedstawiono zestawienie wyników uzyskanych dla przejazdów wykonanych na terenie Gdańska, w regularnym ruchu miejskim. Przedstawiono także...
-
Estimation of cavitation erosion resistance of materials
PublikacjaW pracy przedstawiono ocenę odporności kawitacyjnej 17 materiałów. Do opisu odporności kawitacyjnej zaproponowano nowy wskaźnik liczbowy uwzględniający długość okresu inkubacji, maksymalną prędkość niszczenia oraz czas po którym wystąpi maksymalna prędkość niszczenia materiału. Zaproponowany wskaźnik porównano ze wskaźnikiem δcav, który reprezentuje całą krzywą erozji kawitacyjnej materiału.
-
Matrix Strengthening the Identification of Observations with Split Functional Models in the Squared Msplit(q) Estimation Process
PublikacjaThis article addresses the issue of raising the level of identification of observations with either single or more split functional models in the squared Msplit(q) estimation process. The theoretical part of the study presents the theoretical grounds for the classical method for estimating parameters in a split functional model and proposes a modification of the computational algorithm to increase the quality of the determinations...
-
Blood Pressure Estimation Based on Blood Flow, ECG and Respiratory Signals Using Recurrent Neural Networks
PublikacjaThe estimation of systolic and diastolic blood pressure using artificial neural network is considered in the paper. The blood pressure values are estimated using pulse arrival time, and additionally RR intervals of ECG signal together with respiration signal. A single layer recurrent neural network with hyperbolic tangent activation function was used. The average blood pressure estimation error for the data obtained from 21 subjects...
-
DMI measurements impact on a position estimation with lack of GNSS signals during Mobile Mapping
PublikacjaNowadays, Mobile Laser Scanning is common in use in addition to geodesy measurements. The data which are provided by the system characterizes with high precision and flexibility. To precise mapping, the accuracy of the data should be maintained. In Poland, according to the minister’s dispositions, the accuracy of the data should not exceeded 10 cm. With fully operated system it is easy to uphold, but there is a situation when a...
-
Improved RSS-Based DoA Estimation Accuracy in Low-Profile ESPAR Antenna Using SVM Approach
PublikacjaIn this paper, we have shown how the overall performance of direction-of-arrival (DoA) estimation using lowprofile electronically steerable parasitic array radiator (ESPAR) antenna, which has been proposed for Internet of Things (IoT) applications, can significantly be improved when support vector machine (SVM) approach is applied. Because the SVM-based DoA estimation method used herein relies solely on received signal strength...
-
Influence of the Phenomenon of Spectrum Leakage on the Evaluation Process of Metrological Properties of Power Quality Analyser
Publikacja -
Opportunistic tri-band carrier aggregation in licensed spectrum for multi-operator 5G hetnet
Publikacja -
Evolution of ‘dementia infantilis to childhood disintegrative disorder, or autism spectrum disorder’: A case report
Publikacja -
Evolution of ‘Dementia Infantilis to Childhood Disintegrative Disorder, or Autism Spectrum Disorder’: A case report
Publikacja -
Modified methods of impulse radio spectrum shaping to improve electromagnetic environment in UWB systems
PublikacjaW publikacji zamieszczono opis metod kształtowania widma ultraszerokopasmowego radia impulsowego w zakresie eliminacji niepożądanych składowych widma. Opisano sposób adaptacji tych metod do zwiększenia odporności transmisji ultraszerokopasmowych na zakłócenia wąskopasmowe i przedstawiono wyniki symulacji komputerowych jakości transmisji w łączu UWB.
-
Carnivorous plants used for green synthesis of silver nanoparticles with broad-spectrum antimicrobial activity
PublikacjaIn this study, we exploit the anti-oxidative potential of four carnivorous plants to produce uniform and biologically active silver nanoparticles. The use of polyvinylpyrrolidone promoted syn-thesis of quasi-spherical nanoparticles characterized by stability and high uniformity. Their activity was tested against three human pathogens and three species of plant pathogenic bacteria. The study demonstrates the influence of synthesis...
-
Conducted EMI mitigation in switched mode DC-DC converters by spread spectrum techniques
PublikacjaW artykule przedstawiono skuteczność technik rozpraszania widma do ograniczenia emisji przewodzonej EMI dla szeregowego przerywacza napięcia. Badania porównawcze zostały wykonane laboratoryjnie za pomocą generatora funkcyjnego, miernika zaburzeń i sieci sztucznej. Analiza otrzymanych wyników wykazała, szczególnie korzystne do 20 dB, ograniczenie charakterystyki napięcia emisji przewodzonej dla losowej modulacji częstotliuwości...