Wyniki wyszukiwania - BazTech

1

Assessment of the Acoustic Performance of Walls Made of Calcium Silicate Units Using Surface Mass-Based Models

Rogala Wojciech, Nowicka Elżbieta, Dulak Leszek

Materiały Budowlane

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2025

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nr 8

147--156

EN

The paper presents a method for estimating the single-number sound insulation indexes (Rw, RA,1 and RA,2) of calcium silicate block walls based on surface mass. Empirical formulas based on the mass law were developed. The results indicate the potential for developing an acoustic classification system for solid silicate blocks based on their surface mass. This approach may streamline the design process and serve as a foundation for future standardization efforts.

PL

W artykule przedstawiono sposób szacowania jednoliczbowych wskaźników izolacyjności akustycznej ścian (Rw, RA,1 i RA,2) z bloczków silikatowych na podstawie masy powierzchniowej. Opracowano wzory empiryczne bazujące na prawie masy. Wyniki analiz wskazują na możliwość opracowania klasyfikacji akustycznej bloczków silikatowych na podstawie ich masy powierzchniowej. Proponowane podejście może usprawnić proces projektowania oraz stanowić podstawę do dalszych prac normalizacyjnych.

2

Testing hypotheses about the pentadiagonal banded toeplitz covariance structure

John Mateusz

Journal of Applied Mathematics and Computational Mechanics

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2025

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Vol. 24, nr 2

33--46

EN

In the paper, two tests of pentadiagonal Toeplitz covariance structure are presented. In contrast to standard testing procedures, the likelihood ratio test and the Rao score test, based on maximum likelihood estimation, which in the considered case requires computationally intensive numerical algorithms, the estimators obtained by projection onto the linear space of banded Toeplitz matrices or onto the asymptotic cone of nonnegative definite banded Toeplitz matrices are applied. To investigate the behavior of the test statistics distributions, the simulation study is performed for two particular examples of pentadiagonal Toeplitz structured covariances.

3

Contribution to a New Algorithm to Perform an Automatic Self-Calibration of Current Sensors

Beladjine Djamel Eddine, Boudana Djamel, Moualdia Abdelhafidh, Wira Patice

Power Electronics and Drives

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2024

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Vol. 9 (44)

446--462

EN

Sensors calibration plays a crucial role in controlling systems and achieving fault-tolerant control by ensuring accuracy, performance, safety, energy efficiency, and compliance with standards. It is an essential to maintain the reliability and effectiveness of modern control systems across various applications. In this paper, we represent a new algorithm that processes a set of raw data collected by a sensor to find the mapping function that relates the raw data to the real value of the measured signal by the sensor. Working on sensors with an unknown mapping function, unknown parameters, or with external disturbances, that affects their behaviour, represents a problem; moreover, it takes a lot of time and effort to calibrate the sensor before each use. Several techniques were used to overcome these aspects mostly by recording the output of the sensor for different input values that change manually, to calibrate the sensor. However, the represented technique in this paper can easily provide us with the input/output model of a specific sensor by doing only one experiment; it also improves the accuracy of the measurements as it is a self-calibrating technique that reduces the nonlinearity and noise problems to deliver a better estimation of the measured signal, which is validated in this paper experimentally using a low-cost current sensor by comparing the obtained results from this algorithm with the results using the extracted input/output model illustrated in the datasheet. Furthermore, if the sensor is pretty poor, and if the application requires more precision, the provided estimation by the mapping function can be mixed with other sensor/s readings using sensor fusion algorithms to find a more precise value of the input. The represented algorithm can also perform self-calibration while evaluating the functionality of the application and the variations of the temperature and other external disturbances that affect the sensor.

4

Spatial evaluation rainfall estimation on weather radar using Marshall-Palmer reflectivity-rainfall rate in Banten

Hartanto, Humaidi Syahrul, Frida Erna, Ananda Naufal, Sinambela Marzuki

Journal of Water and Land Development

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2024

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no. 62

193--200

EN

Based on data from the National Disaster Management Agency (Ind.: Badan Nasional Penanggulangan Bencana - BNPB), throughout 2022, more than 91% of disaster events were hydrometeorological disasters, with floods at 43% and landslides at 17%. One of the factors for floods and landslides is high rainfall intensity. Automatic rain gauge (ARG) is a rainfall observation instrument that can accurately measure rainfall at observation points. However, it has problems such as communication systems that cause delays in data transmission, low instrument density, and inability to cover a wide spatial area, which can affect the accuracy of rainfall information. Weather radar is a remote sensing instrument that can estimate rainfall spatially so that weather radar observations can reach areas of the region that do not have ARG. However, before being used as rainfall information, estimation rainfall needs to be evaluated or calibrated. Evaluation of rainfall estimation on weather radar to ARG in Banten at a 30-120 km distance range, shows a coefficient of determination above 0.8. Based on the studies that have been conducted, increase of root mean square error (RMSE) is due to influence of radar observation range and observation distance on ARG. Adjustment of rainfall estimation improves the accuracy of rainfall estimation. Adjusting rainfall estimation can reduce RMSE by 50%.

5

Vision-based experimental study of force estimation in the cable-stayed bridge’s cable model

Li Yanhao, Yussof Mustafasanie M., Tan Xing, Yuan Shicai

Archives of Civil Engineering

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2024

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Vol. 70, nr 4

149--162

EN

In this paper, a vision-based measurement is proposed, so as to realize quick and convenient tests on the cable force of single-cable plane cable-stayed bridge. Firstly, laser is used to lay out the reference points, and pictures are taken by mobile phone or camera, gaining cable sag by serial image processing. The next step is to calculate the cable force by its relation with sag. According to laboratory test of cable force, the measuring error of cable force is within 3%, which meets the engineering precision requirements. This simple, efficient and low-risk method is easy to operate, and can solve the difficulty of marker installation during visual measurement.

6

Non-parametric comparison of survival functions with censored data: A computational analysis of greedy and Monte Carlo approaches

Štěpánek Lubomír, Habarta Filip, Malá Ivana, Marek Luboš

Annals of Computer Science and Information Systems

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2024

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Vol. 39

725--730

EN

Comparison of two survival functions, which describe the probability of not experiencing an event of interest by a given time point in two different groups, is a typical task in survival analysis. There are several well-established methods for comparing survival functions, such as the log-rank test and its variants. However, these methods often come with rigid statistical assumptions. In this work, we introduce a non-parametric alternative for comparing survival functions that is nearly free of assumptions. Unlike the log-rank test, which requires the estimation of hazard functions derived from (or facilitating the derivation of) survival functions and assumes a minimum number of observations to ensure asymptotic properties, our method models all possible scenarios based on observed data. These scenarios include those in which the compared survival functions differ in the same way or even more significantly, thus allowing us to calculate the p-value directly. Individuals in these groups may experience an event of interest at specific time points or may be censored, i.e., they might experience the event outside the observed time points. Focusing on all scenarios where survival probabilities differ at least as much as observed usually requires computationally intensive calculations. Censoring is treated as a form of noise, increasing the range of scenarios that need to be calculated and evaluated. Therefore, to estimate the p-value, we compare a greedy approach that computes all possible scenarios in which groups' survival functions differ as observed or more, with a Monte Carlo simulation of these scenarios, alongside a traditional approach based on the log-rank test. Our proposed method reduces the first type error rate, enhancing its utility in studies where robustness against false positives is critical. We also analyze the asymptotic time complexity of both proposed approaches.

7

Laboratory testing and modelling of magnetorheological elastomers in tension mode

Gutenko Denys, Orkisz Paweł, Sapiński Bogdan

Acta Mechanica et Automatica

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2024

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Vol. 18, no. 2

291--299

EN

The study deals with experimental testing and estimating the modified Dahl model parameters of magnetorheological elasto-mers (MREs) differing in volumetric concentrations of carbonyl iron particles (CIP). The authors present briefly an overview of scientific re-ports relating to MREs research. Next, they describe the structure and magnetic properties of two fabricated MREs, which were investigat-ed using a scanning electron microscope, a magnetometer and a gaussmeter. Then, they reveal the structure of a specially engineered test rig for materials sample examination and present a scenario of experiments. Next, the test results of the material’s mechanical proper-ties conducted in the absence and presence of a magnetic field were discussed. Then, they describe a modified Dahl model of the material followed by parameters estimation and validation procedure. Finally, the authors summarise the test results and outline further research steps.

8

The DIA-method for navigational integrity

Teunissen P. J. G.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

157--161

EN

In this contribution we present a review of the DIA-method to ensure navigational integrity. The DIA-method rigorously combines parameter estimation and statistical testing for the Detection, Identification and Adaptation of multivariate and multiple model misspecifications. We describe the statistical properties of the so-obtained DIA-estimator together with its probability density function. Numerical examples are given to highlight various aspects of the navigational DIA-estimator.

9

Właściwości dynamiczne układu pomiarowego ciśnienia w przepływie

Pieniążek Jacek, Cieciński Piotr, Szumski Marek

Przegląd Elektrotechniczny

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2023

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R. 99, nr 10

212--215

PL

W artykule zaprezentowano wyniki pomiarów ciśnienia w strudze zaśmigłowej oraz wyniki modelowania metodą CFD. Wyniki symulacji posłużyły do identyfikacji modeli dynamicznych dla dwóch wersji rurki Pitota zastosowanych w układzie pomiarowym. Wyznaczone na tej podstawie charakterystyki częstotliwościowe umożliwiło określenie wpływu charakterystyk dynamicznych rurki Pitota na charakterystykę sygnału uzyskiwanego w układzie pomiarowym.

EN

Results of pressure measurements beyond propeller and the results of CFD simulation are experimental part of the paper. Simulation results were used to identify dynamic models for two versions of the Pitot tube used in the measuring system. Frequency responses calculated on this basis made it possible to determine the influence of dynamic characteristics of the Pitot tube on the characteristics of the signal obtained in the measuring system.

10

Odtwarzanie położenia wału dla prędkości zerowej w napędzie z PMSM z użyciem analizy głównych składowych

Urbański Konrad, Janiszewski Dariusz

Przegląd Elektrotechniczny

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2023

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R. 99, nr 5

237--242

PL

W pracy przedstawiono sposób odtwarzania położenia wału silnika synchronicznego z magnesami trwałymi z wykorzystaniem dodatkowego prądu wysokiej częstotliwości. Uzyskany hodograf tego prądu przetwarzany jest z użyciem analizy głównych składowych. Rezultatem przetwarzania jest informacja o poziomie dopasowania do poszczególnych wzorców. Wzorzec o najlepszym dopasowaniu określa odtworzone położenie wału maszyny. Badania zostały przeprowadzone z użyciem danych pomiarowych laboratoryjnego układu napędowego z PMSM.

EN

This paper presents a method of estimating the shaft position of a permanent magnet synchronous motor using an additional high-frequency current. The resulting hodograph of this current is processed using principal component analysis. The result of the processing is information about the level of fit to individual patterns. The pattern with the best match determines the estimated shaft position. The research was carried out using measurement data of a laboratory drive with a PMSM.

11

Estimation of synchronous generator and AVR parameters based on gradient and genetic methods

Dobrzyński Krzysztof

Przegląd Elektrotechniczny

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2023

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R. 99, nr 6

88--92

EN

The author present a method for the estimation of selected synchronous generator model and AVR parameters using a gradient and a genetic algorithm. The paper shows an example of model parameter estimation for a turbogenerator, based on the generator voltage time responses obtained during an active and reactive power rejection test.

PL

Autor przedstawia metodę estymacji wybranego modelu generatora synchronicznego i parametrów AVR z wykorzystaniem algorytmu gradientowego i genetycznego. W artykule przedstawiono przykład estymacji parametrów modelu turbogeneratora w oparciu o odpowiedzi napięciowe generatora uzyskane podczas testu zrzutu mocy czynnej i biernej.

12

Frequentist inference on traffic intensity of M/M/1 queuing system

Dutta Kaustav, Choudhury Amit

Operations Research and Decisions

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2023

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Vol. 33, No. 1

21--34

EN

When we study any queuing system, the performance measures reflect different features of the system. In the classical M/M/1 queuing system, traffic intensity is perhaps the most important performance measure. We propose a fresh and simple estimator for the same and show that it has nice properties. Our approach is frequentist. This approach has the dual advantage of practical usability and familiarity. Our proposed estimator is attractive as it possesses desirable properties. We have shown how our estimator lends itself to testing of hypothesis. Confidence intervals are constructed. Sample size determination is also discussed. A comparison with a few similar estimators is also performed.

13

A neural network for monitoring and characterization of buildings

Romańska-Zapała Anna, Dudzik Marek, Kuc Sabina

Inżynieria Bezpieczeństwa Obiektów Antropogenicznych

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2023

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Nr 4

134--143

EN

This paper continues work from part 1 where a high precision estimator for energy efficiency and indoor environment based on artificial neural networks (ANN) was examined. Part 1 demonstrated that creating a precise representation of a mathematical relationship one must evaluate the stability and fitness under randomly changing initial conditions. Now, we extend our requirements for the model to be rapid and precise. At the end of this work we obtain a road map for the design and evaluation of ANN-based estimators of the given performance aspect in a complex interacting environment. This paper also shows that ANN system designed may have a high precision in characterizing the response of the building exposed to variable outdoor climatic conditions. The absolute value of the relative errors, MaxAR, is less than 2%. It proves that monitoring and ANN-based characterization approach can be used for different buildings, including those with the best environmental performance.

14

Fault diagnosis-based observers using Kalman filters and Luenberger estimators: Application to the pitch system fault actuators

Zemali Zakaria, Cherroun Lakhmissi, Hadroug Nadji, Nadour Mohamed, Hafaifa Ahmed

Diagnostyka

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2023

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Vol. 24, No. 1

art. no. 2022110

EN

This paper aims to present a robust fault diagnosis structure-based observers for actuator faults in the pitch part system of the wind turbine benchmark. In this work, two linear estimators have been proposed and investigated: the Kalman filter and the Luenberger estimator for observing the output states of the pitch system in order to generate the appropriate residual between the measured positions of blades and the estimated values. An inference step as a decision block is employed to decide the existence of faults in the process, and to classify the detected faults using a predetermined threshold defined by upper and lower limits. All actuator faults in the pitch system of the horizontal wind turbine benchmark are studied and investigated. The obtained simulation results show the ability of the proposed diagnosis system to determine effectively the occurred faults in the pitch system. Estimation of the output variables is effectively realized in both situations: without and with the occurrence of faults in the studied process. A comparison between the two used observers is demonstrated.

15

Estimation of fuel consumption in a jet engine based on vibration signal parameters

Szymański Grzegorz M., Cywka Bartłomiej, Mokrzan Daniel, Prokopowicz Wojciech

Combustion Engines

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2023

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R. 62, nr 3

13--20

EN

This paper proposes the use of vibroacoustic signal parameters to estimate the fuel consumption of a miniature GTM-400 engine. The method for testing engine vibrations is presented, followed by an analysis of the results obtained. Two vibration point measures were selected to build a fuel consumption model. The models obtained were verified, after which those that best describe the real fuel consumption of the engine were selected. The paper proves that the vibration signal, in addition to its applications in jet engine diagnostics, can be used to determine engine performance, which can contribute to reducing the complexity of construction and increasing the economics of engine operation.

16

Estimation of absolute distance and height of people based on monocular view and deep neural networks for edge devices operating in the visible and thermal spectra

Gąsienica-Józkowy Jan, Cyganek Bogusław, Knapik Mateusz, Głogowski Szymon, Przebinda Łukasz

Annals of Computer Science and Information Systems

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2023

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Vol. 35

503--511

EN

Accurate estimation of absolute distance and height of objects in open area conditions is a significant challenge. In this paper, we address these problems and we propose a novel approach that combines classical computer vision algorithms with modern neural network-based solutions. Our method integrates object detection, monocular depth estimation, and homography- based mapping to achieve precise and efficient estimations of absolute height and distance. The solution is implemented on the edge device, which enables real-time data processing using both visual and thermography data sources. Experimental evaluation on a height estimation dataset prepared by us demonstrates an accuracy of 97.06\% and validates the effectiveness of our approach.

17

Enhancing naive classifier for positive unlabeled data based on logistic regression approach

Płatek Mateusz, Mielniczuk Jan

Annals of Computer Science and Information Systems

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2023

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Vol. 35

225--233

EN

It is argued that for analysis of Positive Unlabeled (PU) data under Selected Completely At Random (SCAR) assumption it is fruitful to view the problem as fitting of misspecified model to the data. Namely, it is shown that the results on misspecified fit imply that in the case when posterior probability of the response is modelled by logistic regression, fitting the logistic regression to the observable PU data which does not follow this model, still yields the vector of estimated parameters approximately colinear with the true vector of parameters. This observation together with choosing the intercept of the classifier based on optimisation of analogue of F1 measure yields a classifier which performs on par or better than its competitors on several real data sets considered.

18

Mineralogical analysis of iron ore using ultrasonic wave propagation parameters

Morkun Natalia, Fischerauer Gerhard, Tron Vitalii, Gaponenko Alona

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 3

364--371

EN

Availability, relative simplicity and low cost, combined with ever-increasing capabilities, have led to a significant increase in the use of ultrasonic measurements of mining process variables in recent times. The scope of application varies from the study of the characteristics of raw materials and products of its processing to the operational assessment of the current parameters characterising the state of the process equipment. The purpose of this study is to develop methods for obtaining information about the characteristics of mineral raw materials as a result of ultrasonic logging of wells in a rock mass. The proposed approach makes it possible to improve the quality of information support for the management of technological processes of mining and processing of ore and thereby improve the quality of products supplied to the metallurgical stage and reduce overall production costs.

19

Estymacja kosztów energii elektrycznej w instalacjach z oprawami drogowymi led

Krukowski Marek, Popławski Tomasz, Krukowski Bartosz

Rynek Energii

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2022

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Nr 2

61--68

PL

W 2006 roku oświetlenie odpowiadało za 19 proc. światowego zużycia energii elektrycznej czynnej. Dzięki inwestycjom w oprawy LED w ciągu 12 lat udział ten spadł do 13 proc., a w 2030 roku powinien osiągnąć pułap 8 proc. Autorzy przedstawiają, na przykładzie wybranego miasta (ilość mieszkańców ponad 100 000) koncepcję realizacji tej idei opartej na wymianie 1:1 - oprawy ze źródłami LED w miejsce opraw wyładowczych. Opisują metodologię tej wymiany oraz zaimplementowanie systemów sterowania. Na podstawie pomiarów parametrów elektrycznych opraw, przedstawiają estymowane koszty zużycia składowych energii elektrycznej w ciągu roku. Dokonują także oceny efektywności energetycznej analizowanej instalacji ze sterowaniem zegarami astronomicznymi.

EN

In 2006, lighting was responsible for 19 percent. global active electricity consumption. Thanks to investments in LED luminaires, this share has dropped to 13% within 12 years, and in 2030 it should reach the level of 8%. The authors present, based on the example of a selected city (population over 100,000), the concept of implementing this idea based on the 1: 1 exchange - luminaires with LED sources in place of discharge luminaires. They describe the methodology of this exchange and the implementation of control systems. Based on the measurements of electrical parameters of luminaires, they present the estimated costs of consumption of electrical energy components during the year. They also assess the energy efficiency of the analyzed installation with the control of astronomical clocks.

20

Wykorzystanie wejściowych map głębi w estymacji głębi po stronie dekodera

Klóska Dominika, Szydełko Błażej, Mieloch Dawid

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2022

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nr 4

392--395

PL

Artykuł opisuje usprawnienia procesu estymacji map głębi po stronie dekodera wizji wszechogarniającej. W prezentowanej propozycji mapy głębi są przesyłane tylko dla części widoków, umożliwiając znaczące zmniejszenie czasu wymaganego na estymację geometrii przy jednoczesnym zwiększeniu jej jakości. Rozwiązanie obejmuje modyfikację oprogramowania ISO/IEC MPEG służącego do wyznaczania geometrii sceny oraz implementacji kodera MPEG Immersive Video. Wyniki testów obejmują porównanie czasu dekodowania i uzyskiwanych prędkości bitowych.

EN

This paper presents a proposal to improve the depth estimation process performed in decoder-side depth estimation. In the proposed solution, depth maps are sent only for a part of the views, allowing a significant reduction in the time required for geometry estimation and a simultaneous increase of its quality. The solution includes the modification of the ISO/IEC MPEG Video Coding software for depth estimation and the implementation of the MPEG Immersive Video encoder. The test results consist of the comparison of decoding times and required bitrates.