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Search results for: UNCERTAINTY ANALYSIS
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Uncertainty analysis of measuring system for instantaneous power research
PublicationThe paper presents a metrological analysis of the measurement system used for diagnosis of induction motor bearings, based on the analysis of the instantaneous power. This system was implemented as a set of devices with dedicated software installed on a PC. A number of measurements for uncertainty estimation was carried out. The results of the measurements are presented in the paper. The results of the aforementioned analysis helped...
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The conception of uncertainty analysis of reliability assessment of the MC type diesel engine lubricating oil system
PublicationOmówiono elementy składające się na niepewność oszacowania niezawodności instalacji oleju smarowego dla silników typu MC. Przedstawiono, posługując się przykładem obliczeniowym, koncepcję analizy niepewności oceny rozpatrywanej instalacji. Ponadto zaproponowano sposób interpretacji otrzymanego wyniku, obarczonego dużą niepewnością, przy użyciu liczb rozmytych.
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Modelling and uncertainty in system analysis for safety assessment.
PublicationArtykuł obejmuje zagadnienia związane z modelowaniem i reprezentacją niepewności i ilościowych oszacowaniach ryzyka. Problem jest istotny w praktyce, ponieważ wystęopujhą wymagania przeprowadzenia ocen niepewności miar probabilistycznych i ryzyka. Dyskutuje się potencjalne żródła niepewności i dokonuje sie przeglądu podstaw teoretycznych reprezentacji niepewności. W modelowaniu systemów zawierających nieprecyzyjnie zdefiniowane...
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An Analysis of Uncertainty and Robustness of Waterjet Machine Positioning Vision System
PublicationThe paper presents a new Automatic Waterjet Positioning Vision System (AWPVS) and investigates components of workpiece positioning accuracy. The main purpose of AWPVS is to precisely identify the position and rotation of a workpiece placed on a waterjet machine table. Two webcams form a basis for the system, and constitute its characteristics. The proposed algorithm comprises various image processing techniques to assure a required...
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Analysis of Uncertainty of the Emission Measurement of Gaseous Pollutants on Chassis Dynamometer
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Challenges of the risk analysis of critical systems for insurance purposes under uncertainty
PublicationProponuje się metodę analizy ryzyka dla celów ubezpieczeniowych. Podkreśla się, że zarządzanie bezpieczeństwem systemów podwyższonego ryzyka i systemów krytycznych, obejmujące instrumenty Ubezpieczeniowe, wymaga stosowania odpowiednich metod szczególnej analizy ryzyka z uwzględnieniem problemu niepewności. Proponuje się podejście reprezentowania niepewności w ocenach ryzyka za pomocą przedziałów liczbowych, ogólnie przedziałów...
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Uncertainty in maritime risk analysis: Extended case study on chemical tanker collisions
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Integrated model for the fast assessment of flood volume: Modelling – management, uncertainty and sensitivity analysis
PublicationThe specific flood volume is an important criterion for assessing the performance of sewage networks. It has been shown that its value is greatly influenced by the layout of the sewers in the catchment area, which is usually expressed by a fractal dimension. Currently, only mechanistic models (such as SWMM) enable the determination of the impact of the layout of the sewers on flooding volume, but they require additional and robust...
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Analysis of Investments in RES Based on the Example of Photovoltaic Panels in Conditions of Uncertainty and Risk—A Case Study
PublicationThe aim of this study is to examine the profitability of investment in a photovoltaic microinstallation, to analyze the impact of legal changes on its profitability, and to perform a sensitivity analysis of the investment profitability to energy price changes. The novelty of the research applies to the financial analysis of two legal systems of discount called net-metering and net-billing. The two systems and the change in energy...
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Analysis of measurement uncertainty for contact-less method used to measure the position of catenary contact wire, performed with the use of Monte Carlo method
PublicationCurrently the majority of main railway lines in Europe are electrified, and electric trains have the biggest share in the entire amount of rail transport. Reliability of electrified railways is closely related to the issue of supplying traction vehicles with energy. The problems connected with diagnostics of energy consumption node, namely the contact line and the current collector, are therefore of fundamental importance for maintaining...
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Uncertainty in emotion recognition
PublicationPurpose–The purpose of this paper is to explore uncertainty inherent in emotion recognition technologiesand the consequences resulting from that phenomenon.Design/methodology/approach–The paper is a general overview of the concept; however, it is basedon a meta-analysis of multiple experimental and observational studies performed over the past couple of years.Findings–The mainfinding of the paper might be summarized as follows:...
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Impact of probability distribution on the uncertainty of resistance measurement
PublicationThe paper presents studies on the influence of probability distributions on the expanded uncertainty of the resistance measurement. Choosing the correct probability distribution is very important to estimate of measurement uncertainty. The paper presents the results of analysis of the resistance measurement uncertainty using the technical method of resistance: 100 G. The analysis of the uncertainty...
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Estimation of the uncertainty of the AC/AC transducer output voltage
PublicationThe paper presents a methodology for estimating uncertainty of voltage transducers processing function, on the example of CYVS411D07 voltage transducers. The analysis was conducted using the method based on the GUM Guide propagation of uncertainty law and the determination of the coverage factor based on the effective number of degrees of freedom (t-Student distribution). The paper also presents example evaluation results of measured...
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Estimating the uncertainty of the liquid mass flow using the orifice plate
PublicationThe article presents estimation of measurement uncertainty of a liquid mass flow using the orifice plate. This subject is essential because of the widespread use of this type of flow meters, which renders not only the quantitative estimation but also qualitative results of this type so those measurements are important. To achieve this goal, the authors of the paper propose to use the theory of uncertainty. The article shows the...
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Uncertainty estimation of loop impedance measurement determined by the vector method
PublicationThis article presents a detailed analysis of uncertainty estimation of loop impedance measurement determined by the vector method. The analysis includes the following estimates: resistance variance, voltage variance and time measurement variance. This paper presents a methodology for estimating the combined standard uncertainty of loop impedance by the vector method. The vector method allows to determine loop impedance based on...
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Uncertainty of the liquid mass flow measurement using the orifice plate
PublicationThe article presents an estimation of measurement uncertainty of a liquid mass flow using the orifice plate. This subject is essential because of the widespread use of this type of flow meters. Not only the quantitative estimation but also the qualitative results of those measurements are important. To achieve these results the authors of the paper propose to use the theory of uncertainty. The article shows the analysis of the...
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Modelling of Abdominal Wall Under Uncertainty of Material Properties
PublicationThe paper concerns abdominal wall modelling. The accurate prediction and simulation of abdominal wall mechanics are important in the context of optimization of ventral hernia repair. The shell Finite Element model is considered, as the one which can be used in patient-specific approach due to relatively easy geometry generation. However, there are uncertainties in this issue, e.g. related to mechanical properties since the properties...
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Estimation of the uncertainty of the LEM CV 3-500 transducers processing function
PublicationThe paper presents the methodology for estimating uncertainty of a voltage transducer processing function based on the example of LEM CV 3-500 transducer. The analysis was performed using the method based on the GUM Guide propagation of uncertainty law and the Monte Carlo numerical method. The article also presents a comparative analysis of the results of a voltage measurement evaluation done using the Monte Carlo simulation method,...
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Modeling nutrient removal and energy consumption in an advanced activated sludge system under uncertainty
PublicationActivated sludge models are widely used to simulate, optimize and control performance of wastewater treatment plants (WWTP). For simulation of nutrient removal and energy consumption, kinetic parameters would need to be estimated, which requires an extensive measurement campaign. In this study, a novel methodology is proposed for modeling the performance and energy consumption of a biological nutrient removal activated sludge system...
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Evaluation of expanded uncertainty of instantaneous power measurement in a bearing diagnostic system.
PublicationThe paper presents the issues concerning the estimation of the expanded uncertainty in the system for the diagnosis of rolling bearings, consisting of transducers: voltage and current voltage, which is used for diagnostic bearing motors method based on the measurement and analysis of the instantaneous power signal consumed by the induction motor. It presents the methodology for assessing the measurement uncertainty and presents...
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INFLUENCE OF WRONGLY ASSUMED PROBABILITY DISTRIBUTION ON THE UNCERTAINTY OF RESISTANCE MEASUREMENT BY TECHNICAL METHOD
PublicationThe paper presents studies on the influence of probability distributions on the expanded uncertainty of the resistance measurement. Choosing the correct probability distribution is very important to estimate of measurement uncertainty. The most commonly used distribution is the rectangular distribution. The paper presents the results of analysis of the resistance measurement uncertainty using the technical method of two resistances:...
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Uncertainty assessment of ultimate strength of corroded stiffened plates subjected to different maintenance actions
PublicationThe study deals with the uncertainty assessment of different governing factors related to the ultimate strength of the corroded stiffened plates. The load-carrying capacity is predicted with the use of the nonlinear Finite Element Method. The most influencing governing factors in the non-linear FE analysis, such as material properties and initial imperfections are modeled and analysed as stochastic variables. The ultimate strength...
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Determining and verifying the safety integrity level of the safety instrumented systems with the uncertainty and security aspects
PublicationSafety and security aspects consist of two different group of functional requirements for the control and protection systems. In the paper it is proposed that the security analysis results can be used as a factor increasing or decreasing the risk level. It concerns a process of determining required safety integrity level of given safety functions. The authors propose a new approach for functional safety risk analysis. In this case...
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Efficient uncertainty quantification using sequential sampling-based neural networks
PublicationUncertainty quantification (UQ) of an engineered system involves the identification of uncertainties, modeling of the uncertainties, and the forward propagation of the uncertainties through a system analysis model. In this work, a novel surrogate-based forward propagation algorithm for UQ is proposed. The proposed algorithm is a new and unique extension of the recent efficient global optimization using neural network (NN)-based...
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Uncertainty Quantification in Experimental Structural Dynamics Identification of Composite Material Structures
PublicationComposite materials are widely used in manufacture of aerospace and wind energy structural components. These load carrying structures are subjected to dynamic time-varying loading conditions. Robust structural dynamics identification procedure impose tight constraints on the quality of modal models estimates obtained from vibration experiments. Modal testing results are influenced by numerous factors introducing uncertainty to...
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Determining and verifying the safety integrity level of the controland protection systems under uncertainty
PublicationThe probabilistic models of the electrical, electronic and programmable electronic (E/E/PE)systems, which are proposed in the IEC 61508 and IEC 61511 standards, do not cover the uncertainty aspectsof results obtained from these models. The proposed method takes into consideration the sensitivity analysisof probabilistic models of E/E/PE systems as well as the uncertainty of probabilistic results. It uses differentialfactors, which...
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The Influence of Camera and Optical System Parameters on the Uncertainty of Object Location Measurement in Vision Systems
PublicationThe article presents the influence of the camera and its optical system on the uncertainty of object position measurement in vision systems. The aim of the article is to present the methodology for estimating the combined standard uncertainty of measuring the object position with a vision camera treated as a measuring device. The identification of factors affecting the location measurement uncertainty and the determination of their...
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Uncertainty Quantification of Additive Manufacturing Post-Fabrication Tuning of Resonator-Based Microwave Sensors
PublicationReconfigurability, especially in terms of the ability of adjusting the operating frequency, has become an important prerequisite in the design of modern microwave components and systems. It is also pertinent to microwave sensors developed for a variety of applications such as characterization of material properties of solids or liquids. This paper discusses uncertainty quantification of additive-manufacturing-based post-fabrication...
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Influence of vision measurement system spatial configuration on measurement uncertainty, based on the example of electric traction application
PublicationTechnical diagnostics plays a significant role in ensuring operational reliability of electrified rail transport. The most critical point in the transmission of electric energy to vehicles is the sliding contact of the current collector with the traction network. For this reason, work is currently being carried on new measuring methods, whose appliance allows for more complete diagnostics of the contact line and current collectors,...
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Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation
PublicationThe main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant...
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Reducing the Uncertainty of the Moving Object Location Measurement with the Method of Quasi-Multiple Measurement in GNSS Technology in Symmetrical Arrangement
PublicationThe article presents a solution to the problem of limited accuracy of dynamic measurements performed with GNSS receivers. The proposed measurement method is a response to the needs related to the assessment of the measurement uncertainty of the position of the track axis of the rail transport line. However, the problem of reducing the measurement uncertainty is universal for many different situations where high accuracy of positioning...
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The issue of uncertainty of visual measurement techniques for long distance measurements based on the example of applying electric traction elements in diagnostics and monitoring
PublicationRail transport is the most economical and energy-effective in the field of land transport, in particular electrified. In order to ensure efficient and reliable operation of electrified rail transport, the issues of monitoring and diagnostics of the traction infrastructure and vehicles are extremely important. The most critical point in the transmission of electric energy to the vehicle is the sliding contact of the current collector...
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Collective Uncertainty Entanglement Test
PublicationFor a given pure state of a composite quantum system we analyze the product of its projections onto aset of locally orthogonal separable pure states. We derive a bound for this product analogous to theentropic uncertainty relations. For bipartite systems the bound is saturated for maximally entangled statesand it allows us to construct a family of entanglement measures, we shall call collectibility. As thesequantities are experimentally...
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Uncertainty quantification of modal parameter estimates obtained from subspace identification: An experimental validation on a laboratory test of a large-scale wind turbine blade
PublicationThe uncertainty afflicting modal parameter estimates stems from e.g., the finite data length, unknown, or partly measured inputs and the choice of the identification algorithm. Quantification of the related errors with the statistical Delta method is a recent tool, useful in many modern modal analysis applications e.g., damage diagnosis, reliability analysis, model calibration. In this paper, the Delta method-based uncertainty...
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Portico Farmhouses of the Vistula Delta: Architecture, Current State and Finite Element Modelling of Timber Roof Truss under Material and Cross-section Uncertainty
PublicationThe article focuses on the oldest surviving I-type portico houses located in the Vistula Delta, which were built in the 17th and 18th centuries. The study describes the houses’ origins, structure, details of roof structures and technical condition, and it also includes numerical modelling of a roof truss and its mechanical analysis. Numerical models of the roof trusses are defined and analysed by means of the finite element method....
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Peculiarities of measurement uncertainty evaluation at calibrating a ring gauge
PublicationExample S13 from EA-4/02 M:2013 “Calibration of a ring gauge with a nominal diameter of 90 mm” is analyzed. The report uses the kurtosis method and the law of propagation of expanded uncertainty developed by the authors to the expanded uncertainty evaluation. It is shown that the introduction of a coaxiality correction for the ring gauge and the measuring axis of the comparator leads to the need to estimate its standard measurement...
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Metrological analysis of precision of the system of delivering a water capsule for explosive production of water aerosol
PublicationIn this paper an analysis of precision of the system controlling delivery by a helicopter of water-capsule designed for extinguishing large scale fires is presented. The analysis was performed using the numerical method of distribution propagation (Monte Carlo method) supplemented with results of application of the uncertainty propagation method. In addition the optimum conditions for the airdrop are determined to ensure achievement...
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Uncertainty in measuring noise parameters of a communication receiver
PublicationPrzedstawiono sposób pomiarów mocy dźwięku generowanego przez silnik sytemu napędowego z przemiennikiem częstotliwości. Wyprowadzono wyrażenie na niepewność wyznaczania mocy dźwięku emitowanego przez silnik, przy użyciu pomiarów poziomu dźwięku. Niepewność wyników pomiarów była szacowana w oparciu o metodę typu B. Przedstawiono wyniki badań laboratoryjnych i analizy wybranych składników niepewności dla układu napędowego z silnikiem...
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NON-LINE ANALYSIS OF STIFFNESS IN COMPRESSION CONDITIONS
PublicationThe analyzes were aimed at demonstrating the influence of parameters describing the deformation of the structure on the uncertainty of critical force, and the impact of technological imperfections on stress uncertainty in compression conditions. In a linear buckling analysis, the problem is considered only for the initial, permanent state of the stiffness matrix. In the case of demonstrating the influence of initial deformations...
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Uncertainty of Postmortem Time Estimation Based on Potassium Ion Determination in Vitreous Humor Using Potentiometric Ion-Selective Electrode and Microwave-Induced Plasma with Optical Emission Spectrometry Methods
PublicationThere is a need for a reliable and independent evaluation and confirmation of the post-mortem interval (PMI) based on objective factors other than only postmortem changes or temperature measurements. Estimating the PMI by examining the concentration of potassium ions in the vitreous humor (VH) has a tradition in forensic toxicology dating back to the mid-20th century. So far, the methods for determining the presence of potassium...
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Global Surrogate Modeling by Neural Network-Based Model Uncertainty
PublicationThis work proposes a novel adaptive global surrogate modeling algorithm which uses two neural networks, one for prediction and the other for the model uncertainty. Specifically, the algorithm proceeds in cycles and adaptively enhances the neural network-based surrogate model by selecting the next sampling points guided by an auxiliary neural network approximation of the spatial error. The proposed algorithm is tested numerically...
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Risk of incorrect pass-fail decisions associated with assessment uncertainty
PublicationA mathematical framework for calculation teacher's and student's risks of incorrect pass-fail decisions under uncertainty of assessment, is presented. The probabilistic model of assessment process is adapted from interdisciplinary probabilistic theory of measurement.
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Quality of Analytical Results: Classifiying Errors and Estimating Measurement Uncertainty
PublicationThe most important parameter of each analytical result is its reliability. An analytical result is not a constant value; each result has two properties, error and uncertainty. The sources of both these parameters have to be known and their values determined (estimated). All analytical results are obtained by applying an appropriate measuring procedure. The need for reliable results requires application of reliable analytical procedures,...
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Methodology of estimating temperature measurement uncertainty in a system for endurance tests.
PublicationThe team consisting of the article authors developed a non-invasive method and a system for measuring temperature during an endurance test. A thermocouple which provided the required accuracy of changes in temperature dynamics measurements was used for the purpose of the required research. The paper presents the methodology for estimating uncertainty of temperature measurement done with the presented system, using a method based...
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Cryptocurrencies as a speculative asset. How much uncertainty is included in cryptocurrency price?
PublicationThe aim of this paper is to examine the relationship between uncertainty indices (Geopolitical Uncertainty Index and Global Economic Policy Uncertainty Index) and cryptocurrencies. In order to conduct research, the authors collected the data on the major cryptocurrencies (Bitcoin, Ethereum, Tether, Dogecoin and USD coin) which account for 78% of the total market cap. Using panel OLS regression, this study finds that Bitcoin...
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Mispronunciation Detection in Non-Native (L2) English with Uncertainty Modeling
PublicationA common approach to the automatic detection of mispronunciation in language learning is to recognize the phonemes produced by a student and compare it to the expected pronunciation of a native speaker. This approach makes two simplifying assumptions: a) phonemes can be recognized from speech with high accuracy, b) there is a single correct way for a sentence to be pronounced. These assumptions do not always hold, which can result...
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Uncertainty assessment in the safety and security oriented risk analyses
PublicationW artykule przedstawiono uwzględnienie oceny niepewności w procesie związanym z analizą ryzyka i analizą bezpieczeństwa oraz ochroną informacji. Przedstawiona została koncepcja oceny bezpieczeństwa i zarządzania ryzykiem z uwzględnieniem analizy warstw zabezpieczeń LOPA. W artykule nakreślono wyzwania związane z integracją podejścia oceny bezpieczeństwa (safety) i ochrony informacji (security) w projektowaniu systemów zabezpieczeń...
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Observing uncertainty in music tagging by automatic gaze tracking
PublicationIn this paper, a new approach to observe music file tagging process by employing a gaze tracking system is proposed. The study was conducted with the participation of twenty subjects having different musical experience. For the purpose of the experiments a website survey based on a musical database was prepared. It allowed to gather information about music experience of subjects along with music characteristics such as genre, tempo,...
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Estimating uncertainty in analytical procedures based on chromatographic techniques
PublicationTechniki chromatograficzne są bardzo często wykorzystywane w procedurach analitycznych na etapie rozdzielania i oznaczania oraz identyfikacji szerokiego spektrum analitów występujących w próbkach charakteryzujących się złożonym a niekiedy także zmiennym matryce. Bardzo często są jednak sytuacje, że przy oszacowywaniu niepewności wyników oznaczeń końcowych pomija się niepewności związane z procesem chromatograficznym. W efekcie...
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Uncertainty in measuring the power spectrum density of a random signal
PublicationPrzedstawiono sposób oszacowania niepewności wyznaczania gęstości widmowej mocy przebiegu losowego. Przeprowadzono ocenę niepewności estymacji gęstości widmowej mocy biorąc pod uwagę propagację niepewności związanej z rejestracją pojedynczej próbki sygnału w algorytmie cyfrowego przetwarzania sygnału oraz błąd obciążenia estymatora wynikający z zastosowanego modelu matematycznego wielkości wyznaczanej. Wyprowadzono zależności na...