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In this article, gain errors in current sensing for highly dynamic three-phase drives with three current sensor measurements are compensated without the aid of the machine plant model. As three current sensors are used, redundant information from the neutral current measurement is extracted by constructing its mathematical relation with the measured time-varying dq current. The proposed method compensates for non-symmetrical current sensor gain errors even in the presence of offset errors. A Recursive Sliding Window Least Square method is proposed to minimize the computation effort such that the method is suitable to be applied online. It does not incorporate a low-pass filter or averaging method based on electrical speed, making it suitable for highly dynamic applications. It is able to be applied in any three-phase AC machine, as the machine plant is not considered. Analysis, simulation and experimental results obtained from the hardware prototype by mimicking the actual application of high-precision mechatronics demonstrate the validity of the proposed method.

Data assimilation (DA) is a methodology widely used by different disciplines of science and engineering. It is typically applied to continuous systems with numerical models. The application of DA to discrete-event and discrete-time systems including agent-based models is relatively new. Because of its non-linearity and non-Gaussianity, the particle filter (PF) method is often a good option for stochastic simulation models of discrete systems. The probability distributions of model runs, however, make it computationally intensive. The experimental conditions therein are understudied. This paper studied three critical conditions of PF-based DA in a discrete event model: (1) the time interval between two consecutive DA iterations, (2) the number of particles, and (3) the actual level and perceived level of measurement errors (or noises). The study conducted identical-twin experiments of an M/M/1 single server queuing system. The ground truth is imitated in a stand-alone simulation model. The measurement errors are superimposed so that the effect of the three conditions can be quantitatively evaluated in a controlled manner. The results show that the estimation accuracy of such a system using PF is more constrained by the choice of time intervals than the number of particles. An under estimation of measurement errors produces worse state estimates than an over estimation of errors. A correct perception of the measurement errors does not guarantee better state estimates. Moreover, a slight over estimation of errors results in better state estimates, and it is more responsive to abrupt system changes than an accurate perception of measurement errors.

This article proposes a compensation method for gain and offset errors in the current sensing of three-phase AC machine drives with three current sensor measurements during exact or close to standstill conditions. Errors are treated sequentially based on the elliptical trajectory method, a mathematical manipulation by demodulating faulted time-varying d, q currents using the machine position. As three current sensors are used, a correction factor through measured neutral current is proposed such that the impact of machine resistance deviation and inverter non-idealities are minimized. The method does not incorporate any additional hardware, making it low-cost and straightforward in its implementation. It is proposed as a tool for initial commissioning before the machine runs. It is robust to rotor position perturbations and does not need a mechanical lock for compensation in standstill conditions. The effectiveness of the suggested approach is shown by analysis, modelling, and experimental findings acquired from a hardware prototype by mimicking the actual use of high-precision mechatronics.

Measuring the intensity of the electric field of the atmosphere today has become a widespread task of modern meteorology. After all, the distribution of the intensity of the local electric field near the surface of the earth is closely related to the global distribution of thunderstorms and electrified clouds. The force characteristic of an electric field is its intensity. The change in the atmospheric electric field occurs relatively slowly, so electrostatic field mill (EFM) are most widely used to measure the electric field strength. Electrostatic field mills have been used to monitor the electric field in good weather, measure the vertical electric field inside clouds, and observe the movement and evolution of storms. Various designs of EFM have been developed and documented for more than a century, but since the subject is not popularized, their construction methods and calculation features are not documented. Therefore, there was a need to generalize the structure of the device and calculate its metrological characteristics. The work is aimed at increasing the accuracy of measurement and improving the hardware of electrostatic field mills. The task of increasing the accuracy of measuring the electrostatic field on a straight line depends on reducing the errors that occur in the device. The causes of these errors can be attributed to the imperfection of the measurement method or the inconsistency of the measurement object to its model, as well as the properties of the measurement tools. In previous studies, the authors used a mathematical model of the EF sensor, which does not correspond to the real shape of the signal, which created the need for its improvement. In this work, the authors proposed and substantiated a universal mathematical model of the EFM sensor. The paper also provides an analysis of the components of the proposed mathematical model, which will allow choosing the optimal structural parameters of the EFM sensor, which will increase its sensitivity. In addition, the paper proposed its own functional scheme of the EFM and developed a methodology for calculating its instrumental error, which allows to single out critical parameters during the selection of components for the construction of the device. The aspects considered in this article substantiate the relevance of increasing the accuracy of measuring the electrostatic field strength. The work carried out is the beginning of research aimed at improving the hardware of electrostatic field mills., Вимірювання напруженості електричного поля атмосфери на сьогодні стало розповсюдженою задачею сучасної метеорології. Адже розподіл напруженості локального електричного поля поблизу поверхні Землі тісно пов’язаний з глобальним розподілом гроз і електрифікованих хмар. Силовою характеристикою електричного поля є його напруженість. Зміна атмосферного електричного поля відбувається відносно повільно, тому для вимірювання напруженості електричного поля найбільш широко використовуються електростатичні флюксметри (ЕФ). Електростатичні флюксметри знайшли своє застосування для моніторингу електричного поля за гарної погоди, вимірювання вертикального електричного поля всередині хмар та спостереження за рухом і еволюцією штормів. Були розроблені та задокументовані різні конструкції електростатичних флюксметрів протягом більш ніж століття, але оскільки дана тематика не є популяризованою, їх методи побудови та особливості розрахунків не задокументовані. Тому, постала необхідність в узагальненні будови приладу та розрахунку його метрологічних характеристик. Робота направлена на підвищення точності вимірювання та вдосконалення апаратного забезпечення електростатичних флюксметрів. Задача підвищення точності вимірювання електростатичного поля напряму залежить від зменшення похибок, які виникають в приладі. До причин цих похибок можна віднести як недосконалість методу вимірювання або невідповідність об’єкта вимірювання його моделі, так само, як і властивості засобів вимірювання. У попередніх дослідженнях авторами було використано математичну модель сенсору ЕФ, яка не відповідає реальній формі сигналу, що створило необхідність в її вдосконаленні. В даній роботі авторами було запропоновано та обґрунтовано універсальну математичну модель сенсору ЕФ. Також в роботі приведено аналіз складових запропонованої математичної моделі, який дозволить підібрати оптимальні параметри будови сенсору ЕФ, що підвищить його чутливість. Додатково у роботі було запропоновано власну функціональну схему ЕФ та розроблено методологію розрахунку її інструментальної похибки, що дозволяє виділити критичні параметри під час вибору комплектуючих для побудови приладу. Розглянуті аспекти в цій статті обґрунтовують актуальність підвищення точності вимірювання напруженості електростатичного поля. Проведена робота є початком досліджень, направлених на вдосконалення апаратного забезпечення електростатичних флюксметрів.

Pulse wave velocity (PWV), a direct measure of arterial stiffness, is a promising biomarker of cardiovascular risk and a cardiovascular surrogate outcome. The resolution for detecting its smallest clinically significant change is dependent on the expected reproducibility, but there is currently no consensus on this. We estimated the PWV reproducibility in a range of intra-subject values that were observed over a 2 week period in a broad range of participants and under clinically relevant experimental conditions (two observers, morning/afternoon sessions, and number of visits) using SphygmoCor and Arteriograph devices. Each participant was recorded 12 times with each device over three visits, one week apart, and two morning and two afternoon recordings were taken per visit. The factors affecting reproducibility and the discrepancies between the consecutive PWV measurements for each device were also examined using multilevel mixed-effect models. We show that current PWV estimation guidance recommending 2 + 1 measurements is suboptimal because the PWV range was outside of the 1 m/s threshold for most of the participants, which is proposed as a minimal clinically important difference. The best reproducibility was yielded with median of four measurements and a 1.1 m/s threshold. Although PWV reproducibility and repeatability are frequently used interchangeably in studies, we demonstrated that despite their relative measures of variability (e.g., coefficient of variation) being comparable, their ranges revealed a clinically significant difference between them. We also found that different physiological variables were predictors of the discrepancy between the consecutive measurements made by the two devices, which is likely due to their distinct modes of operation. The evidence base for PWV reproducibility is limited, and more research is needed to deepen our understanding of the variation in arterial stiffness over time, as well as fluctuations within a population group and in an intervention setting.

Calibration of measuring instruments in the industry is a process that is done regularly both internally by internal laboratories operating within the companies and externally by accredited external laboratories. The goal of the diploma thesis was to document and carry out the calibration process of a production line within a manufacturing plant, and to deliver a final report on the overall calibration. The result is obtained by calculating the combined uncertainty of the measurement process. As any measurement is gathered certain uncertainties are bound to influence the measurements, in our case we have three main uncertainties which are the standard uncertainty, uncertainty due to the resolution of the measuring instrument and the uncertainty from the calibration certificate from the measuring equipment that is used in the measurement process. The final combined uncertainty is calculated with the standard uncertainty which has a 68% confidence that the true value lies within that range therefore we need to expand the range to obtain a 95% confidence and we achieve this by multiplication of the combined uncertainty with the K = 2 factor. Kalibracija merilnih instrumentov v industriji je proces, ki ga redno interno izvajajo laboratoriji v podjetju in zunanji akreditirani laboratoriji. Cilj diplomskega dela je bil dokumentirati in izvesti postopek kalibracije proizvodne linije v proizvodnem obratu ter izdelati končno poročilo o celotni kalibraciji. Rezultat kalibracijske meritve dobimo z izračunom skupne negotovosti merilnega postopka. Ko so vsemeritve zbrane, določene negotovosti prav gotovo vplivajo na meritve. V našem primeru vplivajo tri glavne negotovosti. Te negotovosti so: standardna negotovost, negotovost zaradi ločljivosti merilnegainstrumenta in negotovost, ki jo določa potrdilo o kalibraciji merilne opreme, ki se uporablja za kalibracijo. Končna kombinirana negotovost meritev se izračuna s standardno negotovostjo, ki ima 68-odstotno zaupanje, da je prava vrednost znotraj z negotovostjo določenega območja. Da bi dobili 95-odstotno zaupanje, moramo območje razširiti. To pa dosežemo z množenjem kombinirane negotovosti z vrednostjo 2.

Вимірювання напруженості електричного поля атмосфери на сьогодні стало розповсюдженою задачею сучасної метеорології. Адже розподіл напруженості локального електричного поля поблизу поверхні Землі тісно пов’язаний з глобальним розподілом гроз і електрифікованих хмар. Силовою характеристикою електричного поля є його напруженість. Зміна атмосферного електричного поля відбувається відносно повільно, тому для вимірювання напруженості електричного поля найбільш широко використовуються електростатичні флюксметри (ЕФ). Електростатичні флюксметри знайшли своє застосування для моніторингу електричного поля за гарної погоди, вимірювання вертикального електричного поля всередині хмар та спостереження за рухом і еволюцією штормів. Були розроблені та задокументовані різні конструкції електростатичних флюксметрів протягом більш ніж століття, але оскільки дана тематика не є популяризованою, їх методи побудови та особливості розрахунків не задокументовані. Тому, постала необхідність в узагальненні будови приладу та розрахунку його метрологічних характеристик. Робота направлена на підвищення точності вимірювання та вдосконалення апаратного забезпечення електростатичних флюксметрів. Задача підвищення точності вимірювання електростатичного поля напряму залежить від зменшення похибок, які виникають в приладі. До причин цих похибок можна віднести як недосконалість методу вимірювання або невідповідність об’єкта вимірювання його моделі, так само, як і властивості засобів вимірювання. У попередніх дослідженнях авторами було використано математичну модель сенсору ЕФ, яка не відповідає реальній формі сигналу, що створило необхідність в її вдосконаленні. В даній роботі авторами було запропоновано та обґрунтовано універсальну математичну модель сенсору ЕФ. Також в роботі приведено аналіз складових запропонованої математичної моделі, який дозволить підібрати оптимальні параметри будови сенсору ЕФ, що підвищить його чутливість. Додатково у роботі було запропоновано власну функціональну схему ЕФ та розроблено методологію розрахунку її інструментальної похибки, що дозволяє виділити критичні параметри під час вибору комплектуючих для побудови приладу. Розглянуті аспекти в цій статті обґрунтовують актуальність підвищення точності вимірювання напруженості електростатичного поля. Проведена робота є початком досліджень, направлених на вдосконалення апаратного забезпечення електростатичних флюксметрів. Measuring the intensity of the electric field of the atmosphere today has become a widespread task of modern meteorology. After all, the distribution of the intensity of the local electric field near the surface of the earth is closely related to the global distribution of thunderstorms and electrified clouds. The force characteristic of an electric field is its intensity. The change in the atmospheric electric field occurs relatively slowly, so electrostatic field mill (EFM) are most widely used to measure the electric field strength. Electrostatic field mills have been used to monitor the electric field in good weather, measure the vertical electric field inside clouds, and observe the movement and evolution of storms. Various designs of EFM have been developed and documented for more than a century, but since the subject is not popularized, their construction methods and calculation features are not documented. Therefore, there was a need to generalize the structure of the device and calculate its metrological characteristics. The work is aimed at increasing the accuracy of measurement and improving the hardware of electrostatic field mills. The task of increasing the accuracy of measuring the electrostatic field on a straight line depends on reducing the errors that occur in the device. The causes of these errors can be attributed to the imperfection of the measurement method or the inconsistency of the measurement object to its model, as well as the properties of the measurement tools. In previous studies, the authors used a mathematical model of the EF sensor, which does not correspond to the real shape of the signal, which created the need for its improvement. In this work, the authors proposed and substantiated a universal mathematical model of the EFM sensor. The paper also provides an analysis of the components of the proposed mathematical model, which will allow choosing the optimal structural parameters of the EFM sensor, which will increase its sensitivity. In addition, the paper proposed its own functional scheme of the EFM and developed a methodology for calculating its instrumental error, which allows to single out critical parameters during the selection of components for the construction of the device. The aspects considered in this article substantiate the relevance of increasing the accuracy of measuring the electrostatic field strength. The work carried out is the beginning of research aimed at improving the hardware of electrostatic field mills.

In studies where the outcome is a change-score, it is often debated whether or not the analysis should adjust for the baseline score. When the aim is to make causal inference, it has been argued that the two analyses (adjusted vs. unadjusted) target different causal parameters, which may both be relevant. However, these arguments are not applicable when the aim is to make predictions rather than to estimate causal effects. When the scores are measured with error, there have been attempts to quantify the bias resulting from adjustment for the (mis-)measured baseline score or lack thereof. However, these bias results have been derived under an unrealistically simple model, and assuming that the target parameter is the unadjusted (for the true baseline score) association, thus dismissing the adjusted association as a possibly relevant target parameter. In this paper we address these limitations. We argue that, even if the aim is to make predictions, there are two possibly relevant target parameters; one adjusted for the baseline score and one unadjusted. We consider both the simple case when there are no measurement errors, and the more complex case when the scores are measured with error. For the latter case, we consider a more realistic model than previous authors. Under this model we derive analytic expressions for the biases that arise when adjusting or not adjusting for the (mis-)measured baseline score, with respect to the two possible target parameters. Finally, we use these expressions to discuss when adjustment is warranted in change-score analyses. In studies where the outcome is a change-score, it is often debated whether or not the analysis should adjust for the baseline score. When the aim is to make causal inference, it has been argued that the two analyses (adjusted vs. unadjusted) target different causal parameters, which may both be relevant. However, these arguments are not applicable when the aim is to make predictions rather than to estimate causal effects. When the scores are measured with error, there have been attempts to quantify the bias resulting from adjustment for the (mis-)measured baseline score or lack thereof. However, these bias results have been derived under an unrealistically simple model, and assuming that the target parameter is the unadjusted (for the true baseline score) association, thus dismissing the adjusted association as a possibly relevant target parameter. In this paper we address these limitations. We argue that, even if the aim is to make predictions, there are two possibly relevant target parameters; one adjusted for the baseline score and one unadjusted. We consider both the simple case when there are no measurement errors, and the more complex case when the scores are measured with error. For the latter case, we consider a more realistic model than previous authors. Under this model we derive analytic expressions for the biases that arise when adjusting or not adjusting for the (mis-)measured baseline score, with respect to the two possible target parameters. Finally, we use these expressions to discuss when adjustment is warranted in change-score analyses.

The combined effect of two real-world-occurring phenomena: ‘measurement errors’ and ‘autocorrelation between observations’ has rarely been investigated. In this paper, it will be investigated for the first time on ‘adaptive’ and/or ’simultaneous monitoring’ charts and also for the first time by using the multivariate linearly covariate measurement errors and VARMA (vector mixed autoregressive and moving average) autocorrelation models, and Markov chains-based performance measures. In addition, this paper for the first time proposes a skip-sampling strategy in an ARMA/VARMA model for alleviating the autocorrelation effect. To do so, we add the above-mentioned measurement errors and autocorrelation models to a recently developed adaptive max-type chart. Then, we develop a Markov chain model to compute the performance measures. After that, extensive numerical analyses will be performed to investigate their combined effect as well as some methods to alleviate their negative effects. Finally, an illustrative example involving a real industrial case will be presented.

In this thesis we study the additive model of errors in variables, which is also known as the deconvolution problem. The objective consists particularly in the reconstruction of the distribution F associated with a random variable X, which is observable only through a sample of a blurred variable Y, due to an additive random error ε with known distribution H. Our initial considerations yield an unbiased estimator for F for various discrete and some continuous distributions. A more general approach then leads us to the symmetrized model of errors in variables. It is obtained by an additional convolution of G with the conjugate error distribution of H, thereby resulting in an error distribution of symmetric type. As a consequence the characteristic function of X can be represented as the limit of a geometric series. By truncation of this series we deduce an approximation of F, which is valid for arbitrary error distributions. This approximation, termed the deconvolution function, converges to F in many cases. To determine the corresponding rates of convergence, techniques from complex calculus and particularly Mellin-Barnes integrals turn out to be appropriate. The latter describe a special class of integrals that can be evaluated by residue analysis. The results are established in a more general setting, which makes them applicable to other Laplace-type integrals. With the aid of the deconvolution function we also construct an estimator for F. The asymptotic properties of its variance, a peculiar integral of dimension two, can be specified by virtue of our findings from the concluding chapter. These results rely on iterated Mellin-Barnes integrals.

The article discusses the compression of digital data of measuring video information. Such compression is an integral part of the data conversion process in computerized information and measurement systems designed to measure linear and angular displacements of objects. Compression of time sequences of video images containing measurement information about the geometric parameters and parameters of movement of objects is necessary to improve the accuracy and speed of means for measuring mechanical quantities. Such compression allows you to significantly reduce the volume of digital data of video images. As a result, images are transmitted over computer networks with acceptable performance indicators and stored in memory. Compression of video images leads to the occurrence of measurement information errors and, accordingly, the accuracy of determining the geometric parameters and parameters of object movement decreases. A mathematical model of measurement information errors on compressed video images is proposed. This mathematical model makes it possible to determine the effect of compression on the measurement accuracy of geometric parameters and object motion parameters depending on the parameters of the compression algorithm. Based on the mathematical model of measurement information errors, the parameters of the JPEG method are determined, it is advisable to use it when compressing video images in a time sequence that displays geometric parameters and motion parameters of objects. This makes it possible to increase the accuracy of measurements by filtering out the noise that has arisen during the formation of video images. An experimental estimate of measurement errors associated with compression is given., У статті розглядається стиснення цифрових даних вимірювальної відеоінформації. Таке стиснення є складовою частиною процесу перетворення даних у комп’ютеризованих інформаційно-вимірювальних системах, що призначені для вимірювання лінійних і кутових переміщень об’єктів. Стиснення часових послідовностей відеозображень, що містять вимірювальну інформацію про геометричні параметри та параметри руху об’єктів, необхідне для підвищення точності та швидкодії засобів вимірювання механічних величин. Таке стиснення дозволяє суттєво зменшити об’єм цифрових даних відеозображень. У результаті зображення передаються по комп’ютерним мережам з прийнятними показниками швидкодії та зберігаються в пам’яті. Стиснення відеозображень приводить до виникнення похибок вимірювальної інформації та відповідно, знижується точність визначення геометричних параметрів та параметрів руху об’єктів. Запропоновано математичну модель похибок вимірювальної інформації на стиснутих відеозображеннях. Ця математична модель дозволяє визначити вплив стиснення на точність вимірювань геометричних параметрів та параметрів руху об’єктів залежно від параметрів алгоритму стиснення. На основі математичної моделі похибок вимірювальної інформації визначено параметри методу JPEG, які доцільно використовувати при стисненні відеозображень у часовій послідовності, що відображає геометричні параметри та параметри руху об’єктів. Це дозволяє підвищити точність вимірювань за рахунок фільтрації шумів, що виникли в процесі формування відеозображень. Наведено експериментальну оцінку похибок вимірювань, пов’язаних зі стисненням.

Errors that occur when surface topography is measured and analysed can be classified depending on the type of surface studied. Many types of surface topographies are considered when frequency-based errors are studied. However, turned surface topography is not comprehensively studied when data processing errors caused by false estimation (definition and suppression) of selected surface features (form or noise) are analysed. In the present work, the effects of the application of various methods (regular Gaussian regression, robust Gaussian regression, and spline and fast Fourier Transform filters) for the suppression of high-frequency measurement noise from the raw measured data of turned surface topography are presented and compared. The influence and usage of commonly used available commercial software, e.g., autocorrelation function, power spectral density, and texture direction, which function on the values of areal surface topography parameters from selected (ISO 25178) standards, are also introduced. Analysed surfaces were measured with a stylus or via non-contact (optical–white light interferometry) methods. It was found that the characterisation of surface topography, based on the analysis of selected features, can be crucial in reducing measurement and data analysis errors when various filters are applied. Moreover, the application of common functions can be advantageous when feature-based studies are proposed for both profile and areal data processing.

The Friis equation is often used to determine the gain of antennas but assumes that far-field conditions are met. For limited antenna separations on the order of the Fraunhofer distance, its use requires a precise estimate of the amplitude centers of the antennas. Using a new antenna gain measurement technique, it is shown that the amplitude center can be very well estimated and that the measurement results can be used to confirm that far-field conditions are met. Moreover, reflections caused by scatterers are averaged since multiple measurements are performed. The presented method is particularly useful for anechoic chambers that are limited in size, such as small anechoic chambers for the characterization of, for instance, 5G millimeter-wave phased arrays.

Includes supplementary materials for the online appendix The Satisfaction With Democracy (SWD) indicator is very often used in social sciences’ research. However, while there is debate about which concept it measures, the discussion about the size of its measurement errors (how well it measures the underlying concept ‘satisfaction with the way democracy works’) is scarce. Nonetheless, measurement errors can affect the results and threaten comparisons across studies, countries and languages. Thus, in this paper, we estimated the measurement quality (complement of measurement errors) of the SWD indicator for 7 response scales across 38 country-language groups, using three multitrait-multimethod experiments from the European Social Survey. Results show that measurement errors explain from 16% (11-point scale) to 54% (4-point scale) of the variance in the observed responses. Additionally, we provide insights to improve questionnaire design and evaluate the indicator’s comparability across scales, countries and languages.

The article presents the experience of converting non-targeted administrative data into research data, using as an example data on the income and property of deputies from local legislative bodies of the Russian Federation for 2019, collected as part of anticorruption operations. This particular empirical fragment was selected for the pilot study of administrative data, which includes assessing the possibility of integrating scattered fragments of information into a single database, assessing quality of data and their relevance for solving research problems, particularly analysis of high-income strata and the apparent trends towards individualization of private property. The system of indicators for assessing data quality includes their timeliness, availability, interpretability, reliability, comparability, coherence, errors of representation and measurement, and relevance. In the case of the data set in question, measurement errors are more common than representation errors. Overall the article emphasizes the notion that introducing new non-target data into circulation requires their preliminary testing, while data quality assessment becomes distributed both in time and between different subjects. The transition from created data to «obtained» data shifts the functions of evaluating its quality from the researcher-creator to the researcheruser. And though in this case data quality is in part ensured by the legal support for their production, the transformation of administrative data into research data involves assessing a variety of quality measurements — from availability to uniformity and accuracy.

ispartof: ANNALS OF STATISTICS vol:50 issue:5 pages:2973-3008 status: published

Current quantum computers are still error-prone, with measurement errors being one of the factors limiting the scalability of quantum devices. To reduce their impact, a variety of readout error mitigation methods, mostly relying on classical post-processing, have been developed. However, the application of these methods is complicated by their heterogeneity and a lack of information regarding their functionality, configuration, and integration. To facilitate their use, we provide an overview of existing methods, and evaluate general and method-specific configuration options. Quantum applications comprise many classical pre- and post-processing tasks, including readout error mitigation. Automation can facilitate the execution of these often complex tasks, as their manual execution is time-consuming and error-prone. Workflow technology is a promising candidate for the orchestration of heterogeneous tasks, offering advantages such as reliability, robustness, and monitoring capabilities. In this paper, we present an approach to abstractly model quantum workflows comprising configurable readout error mitigation tasks. Based on the method configuration, these workflows can then be automatically refined into executable workflow models. To validate the feasibility of our approach, we provide a prototypical implementation and demonstrate it in a case study from the quantum humanities domain.

Surface eroding thermocouples are developed to measure temperatures and heat fluxes in plasma-facing components of fusion machines, especially in the divertor region. Sensor construction leads to a fast response (8ms) and robust design against heat loads around 10-20MW $\cdot \text{m}^{-2}$ . Electrical design of surface thermocouples is developed considering compensation needs and currents expected in the plasma edge. Improved sensor performance is obtained by enhancing the thermal contact surface between the divertor mono-block and the thermocouple carrier body through the integration of conductive collet and bush, both made of copper. The thermal response is analyzed through a finite element non-linear transient model simulating heating due to a plasma discharge. The usual configuration with voltage (emf) measured between the two thermocouple ribbons is compared with a simplified single-ribbon design in which the emf is measured between the thermocouple sole inner ribbon and the divertor support. Measurement errors are discussed for both single-ribbon and double-ribbon designs. The installation of surface thermocouples is studied at different poloidal positions of the DTT divertor vertical targets. A sensor layout with 4mm poloidal resolution is proposed to map power density peaks of plasma-wall interactions. Surface thermocouple measurements can provide useful local information for studying divertor physics, scaling for development of future machines, monitoring of local conditions to assist controlled terminations of plasma discharges. Installed with other diagnostics, they can provide crosschecks for calibration and data validation. The design, development, and integration procedure herein described can be applied to other plasma-facing component embedded sensors measuring plasma parameters like Langmuir probes.

The present study proposes a generalized mean estimator for a sensitive variable using a non-sensitive auxiliary variable in the presence of measurement errors based on the Randomized Response Technique (RRT). Expressions for the bias and mean squared error for the proposed estimator are correctly derived up to the first order of approximation. Furthermore, the optimum conditions and minimum mean squared error for the proposed estimator are determined. The efficiency of the proposed estimator is studied both theoretically and numerically using simulated and real data sets. The numerical study reveals that the use of the Randomized Response Technique (RRT) in a survey contaminated with measurement errors increases the variances and mean squared errors of estimators of the finite population mean.

The popularity of smart sensors and the Internet of Things (IoT) is growing in various fields and applications. Both collect and transfer data to networks. However, due to limited resources, deploying IoT in real-world applications can be challenging. Most of the algorithmic solutions proposed so far to address these challenges were based on linear interval approximations and were developed for resource-constrained microcontroller architectures, i.e., they need buffering of the sensor data and either have a runtime dependency on the segment length or require the sensor inverse response to be analytically known in advance. Our present work proposed a new algorithm for the piecewise-linear approximation of differentiable sensor characteristics with varying algebraic curvature, maintaining the low fixed computational complexity as well as reduced memory requirements, as demonstrated in a test concerning the linearization of the inverse sensor characteristic of type K thermocouple. As before, our error-minimization approach solved the two problems of finding the inverse sensor characteristic and its linearization simultaneously while minimizing the number of points needed to support the characteristic.

In this paper, we suggest how to handle the issue of the heteroskedasticity of measurement errors when specifying dynamic models for the conditional expectation of realized variance. We show that either adding a GARCH correction within an asymmetric extension of the HAR class ( AHAR - GARCH ), or working within the class of asymmetric multiplicative error models ( AMEM ) greatly reduces the need for quarticity/quadratic terms to capture attenuation bias. This feature in AMEM can be strengthened by considering regime specific dynamics. Model Confidence Sets confirm this robustness both in- and out-of-sample for a panel of 28 big caps and the S&P500 index.

Fundamental systematic errors in point cloud data are inevitable due to a variety of factors, ranging from the external environment during scanning or observation by a terrestrial laser scanner (TLS) to the assembly of the instrument. For low-cost scanners, error terms may be further accentuated and included, in addition to systematic errors, random or even serious errors that directly affect the coordinates of each point in the point cloud, which are directly related to the quality of the point cloud data and subsequent processing. To address the above issues, we attempted to propose a robust target-based self-calibration method for TLS at the algorithmic level without considering the network design and measurement configuration, and derived its solution by normalizing the residual vector and calculating an equivalent covariance matrix based on the IGG III function. After validating the simulated and measured data, the experimental results showed that the proposed self-calibration method could effectively eliminate the random and gross errors associated with the observations; improved the accuracy of the points from centimeter to millimeter level; and increased the accuracy of the corrected checkpoints by 58%, 47%, and 33%, respectively, compared to the three existing methods. However, the proposed method was unable to take into account the attenuation of parameter correlations and further refinement in terms of measurement configurations would be subsequently required.

Synchronous phasor measurements have long been an important tool in power flow modelling and network state estimation as well as in many other tasks that support power grid observability. Classic phasor estimation algorithms are often preferred over complex alternatives. They are based on a variant of the Discrete Fourier Transform (DFT) while relying on a sampling frequency locked to the system nominal frequency. The spectral leakage caused by the small off-nominal frequency excursions in such settings introduces errors that are handled by the estimation algorithms to a different extent. Well-known three-point averaging filter (3P) is a low-cost spectral leakage reduction technique in one of the simplest estimators based on a single-bin DFT. However, it only partially removes the oscillating components. When an independent standard-based frequency tracking is available, the errors can be further compensated with minimal cost. We propose a frequency-corrected three-point estimator (F3P) to eliminate the induced spurious spectrum progressively with the increasing sampling rate while building on the analytical expression of the remaining error. We show performance benefits of the F3P under finite sampling rates when compared to the baseline 3P and to the classical Interpolated DFT (IPDFT) in static conditions. The F3P removes most of the leakage without the need of data resampling. In less ideal conditions with additive 50-dB noise, up to a 10-fold reduction of the 3P error is achieved. The error ratio of the reference IPDFT over the F3P is approximately 1.4 under the same conditions and largely independent of the frequency excursion. The presented simulation results prove the algorithm’s superior performance in most of the steady-state tests defined by the relevant Standard, whereas the dynamic performance can be brought to an acceptable level by the use of a single-cycle observation window, with the response times comparable to those of the IPDFT.

In most profile monitoring applications, the explanatory variables are not fixed from profile to profile. However, in most studies, they are assumed to be fixed values. Furthermore, the observed units usually contain some source of uncertainty referred as "measurement errors." In this paper, first the effect of neglecting the measurement errors effect on detection capability of two common control charts for Phase II monitoring of simple linear profiles is evaluated. Then, three remedial approaches including ranked set sampling, multiple measurement and increasing sample size are utilized to decrease the mentioned effect. Simulation studies in terms of average run length (ARL) metric show that neglecting the measurement errors adversely affects the capability of both charts. The results also confirm that the remedial approaches adequately compensate for the mentioned effect.

An algorithm for determining the stadia constant of the rangefinder is developed and tested. This algorithm is based on the generalized reduced gradient (GRG) method with consistent use of criteria of minimizing the maximum deviation and minimizing the total sum of squares of deviations. There were some stages of the research. First, we carried out 200 measurements with equal accuracy by a SOUTH NTS-350 electronic tachometer. The statistical processing of measurement results enabled specification of the optimal number of measurements for the device taking into account the dependence of the correlation values of instrumental and random errors. Having determined the optimal number of measurements, we continued the study of the proposed method of calculating the stadia constant of electronic tachometers. According to the data obtained during the measurement of the range of the target, which consisted of four points, conditional equations were compiled. These conditional equations are based on the relationships between the length of the measured target and its segments in all combinations, taking into account the stadia constant of the rangefinder. Due to the large number of measurements, the solution of such system of equations is to find the minimum of some function for determining the errors of the measured distances. Our methodology is based on the use of the Lagrange multiplier method in finding the solution of a nonlinear programming problem, which in most software resources is called the Nonlinear Generalized Consolidated Gradient (GRG). The essence of this solution is to find a conditional local extremum. In this case, it is most appropriate to consistently use the criteria of minimizing the maximum deviation and minimizing the total sum of squares of deviations. The method of minimizing the maximum deviation makes it possible to reject gross errors in the measured values. The following minimization of the total sum of squares of deviations will allow to minimize random errors of the measured distances, as the selected samples are subject to the normal distribution law. Thus, the most probable value of the constant correction of the rangefinder and lengths of the measured target and its segments for all possible combinations has been obtained.&nbsp, Розроблено та апробовано алгоритм визначення постійної поправки віддалеміра в основі якого є метод узагальненого зведеного градієнта (GRG) з послідовним використанням критеріїв мінімізації максимального відхилення та мінімізації повної суми квадратів відхилень. Дослідження проводились у декілька етапів. Спочатку за допомогою електронного тахеометра SOUTH NTS- 350 було одержано 200 рівноточних вимірів. За допомогою статистичного опрацювання результатів вимірювань було встановлено оптимальну кількість вимірювань для приладу із врахуванням залежності кореляційної величинами інструментальної і випадкової похибок. Визначивши оптимальну кількість вимірів, було продовжено дослідження запропонованої методики розрахунку постійної поправки віддалеміра. За даними, одержаними під час вимірювання віддалей створу, який складався із чотирьох пунктів, було складено умовні рівняння. В основі яких лежать залежності між довжиною виміряного створу та його відрізків у всіх комбінаціях з урахуванням постійної поправки віддалеміра. За наявністю великої кількості вимірювань розв’язання такої системи рівнянь полягає у знаходженні мінімуму деякої функції визначення похибок виміряних віддалей. Розроблена методика базується на використанніметоду множників Лагранжа при знаходженні розв’язку задачі нелінійного програмування, яка у більшості програмних ресурсів має назву - Нелінійний метод узагальненого зведеного градієнта (GRG). Суть даного рішення полягає у знаходженні умовного локального екстремуму. При цьому, найбільш доцільними є послідовне використання критеріїв мінімізації максимального відхилення та мінімізації повної суми квадратів відхилень. Метод мінімізації максимального відхилення дає можливість відбракування грубих помилок у виміряних значеннях. Наступна мінімізація повної суми квадратів відхилень дасть можливість мінімізувати випадкові похибки виміряних віддалей, оскільки обрані вибірки піддаються нормальному закону розподілу. Таким чином, отримано найімовірніше значення постійної поправки віддалеміра, значення довжин виміряного створу та його відрізків, які будуть узгодженими у всіх можливих комбінаціях.&nbsp

Surface texture measurement, characterized by areal parameters, is very susceptible to measurement errors. Various types of errors differently affect surface texture parameters. In this paper, two types of measurement errors were investigated. To analyze the impact of the presence of scratches, circular valleys of various diameters were added to surface textures measured by a white light interferometer. Measurement errors were larger for higher scratches. Skewness and kurtosis were mostly affected by the presence in valleys, and changes of spatial parameters were also comparatively high. The difference between the results of measurement of the same surface details two times after a break of three months was also studied. This difference was caused by errors of relocation, spikes and non-measured point presences, high-frequency noise, and surface ageing. Spatial parameters were found to be the most stable.

The article is devoted to solving the problem of analyzing the influence of errors of measuring instruments used during standardized tests of induction electric motors on the accuracy of estimating the parameters of substitution schemes of these motors. Statement of the problem. To ensure the efficient use of induction motors in adjustable electric drives, it is necessary to obtain information about the parameters of their substitution schemes. Analysis of recent research and publications. There are various methods for estimation of induction motor parameters, the use of which involves the creation of specified conditions and the use of appropriate equipment. But the basic approach is to use the methods given in the international standard IEC 60034-28: 2013. The main disadvantage of these standard methods is the lack of influence of metrological characteristics of measuring equipment on the accuracy of parameter determination. The purpose of the article is to determine the methodology of research and mathematical processing of results for calculating the parameters of substitution schemes of induction motors, as well as to estimate the impact of errors in measuring instruments on the accuracy of parameter determination. Results. In accordance with international standards, the article defines the methodology and sequence of experimental studies of induction motors required to estimate the parameters of substitution schemes in the nominal mode. Also in the article the algorithm of calculation of motor parameters is developed and analytical expressions for calculation of absolute errors of estimation of these parameters are received. The influence of errors of direct measurements on the accuracy of determining the parameters of an induction motor is also analyzed. Conclusion. The obtained results make it possible to determine the requirements for measuring equipment before conducting research of induction motors, which will increase the accuracy of estimating the parameters of induction motors., Статтю присвячено вирішенню задачі аналізу впливу похибок вимірювальних приладів, використовуваних під час виконання стандартизованих тестів асинхронних електричних двигунів, на точність оцінювання параметрів схем заміщення цих двигунів. У статті відповідно до міжнародних стандартів визначено методику та послідовність проведення тестових дос-ліджень асинхронного двигуна, необхідних для оцінювання параметрів його схем заміщення в номінальному режимі роботи. Також розроблено алгоритм розрахунку параметрів двигуна, отримано аналітичні вирази для розрахунку значень абсолютних похибок їх оцінювання та проаналізовано вплив похибок вимірювальних приладів на точність визначення цих параметрів. Використання отриманих у роботі результатів дає змогу оцінити очікувану точність визначення параметрів асинхронних двигунів на етапі, який передує безпосередньо дослідженням, що, в свою чергу, дозволяє сформувати вимоги до вимірювальних приладів.

Measurement results play an important role in providing information about the achievement of student learning outcomes. Unfortunately, accurate and objective information in the measurement of psychological aspects is not easily obtained because of measurement errors. These measurement errors need to be known by the teacher so that the measurement results can be interpreted appropriately. To determine the magnitude of measurement errors, the indicator used by classical test theory is the reliability index. The higher the reliability index, the lower the measurement error; and the smaller the reliability index, the higher the measurement error. This paper aims to describe the approach in calculating reliability index in order to find out the measurement errors of the measuring instrument used. The method used in this study is the study of literature, which is to examine various literature related to measurement errors and reliability of measuring instruments. In estimating measurement errors, there are three approaches that can be applied to estimate the amount of reliability index of a measuring instrument. That approach is the test-retest, the parallel-forms approach, and the internal consistency approach. Each approach is developed in accordance with the nature and function of the measuring instrument concerned with practical aspects in mind.

The calibration technique is the process of adjusting weights for the better enhancement of the estimate of the population parameters using auxiliary information. In this manuscript, we have proposed ratio and regression type calibration estimators for the population mean under both correlated and uncorrelated measurement errors. The variances of the proposed calibrated estimators to the first order approximation are obtained and compared their efficiencies. A Monte Carlo simulation study has been carried out to show the effect of measurement errors on the proposed calibrated estimators.

Intermittent motion mechanisms are widely used in semiautomatic and automatic machinery. Currently, the most common are mechanisms with a one-way coupling or mechanisms of variable structure. The intermittent movement in these mechanisms is provided by breaking the kinematic chain, so their use is undesirable in high-speed machines. The paper presents and analyzes kinematics of planetary transmission with elliptical gears, which performs intermittent motion of output link without interruption of kinematic chain. A kinematic model of the mechanism is constructed, and there are obtained equations for determining the velocity analogue of the output link of the planetary gear. An experimental verification of the adequacy of the developed mathematical model was carried out on the example of studying the position function of the mechanism. The measurement errors were estimated using statistical methods. Using the chi-squared test, the hypothesis of a normal distribution of measurement errors was verified, and confidence interval was determined.

International audience; We survey the recent, fast-growing literature on peer effects in networks. An important recurring theme is that the causal identification of peer effects depends on the structure of the network itself. In the absence of correlated effects, the reflection problem is generally solved by network interactions even in nonlinear, heterogeneous models. By contrast, microfoundations are generally not identified. We discuss and assess the various approaches developed by economists to account for correlated effects and network endogeneity in particular. We classify these approaches in four broad categories: random peers, random shocks, structural endogeneity, and panel data. We review an emerging literature relaxing the assumption that the network is perfectly known. Throughout, we provide a critical reading of the existing literature and identify important gaps and directions for future research.

U radu je prikazan utjecaj mjeritelja i pogrešaka mjerenja na izmjeru prsnog promjera stabla. Istraživanje je provedeno na nastavno-pokusnom šumskom objektu Zagreb: u nizinskoj sastojini hrasta lužnjaka i običnog graba te u sastojini obične jele i bukve (na nagnutom terenu). Pokušalo se obuhvatiti najčešće pogreške pri izmjeri prsnog promjera te su tri mjeritelja mjerila unakrsne prsne promjere stabala na samoodređenoj i označenoj prsnoj visini. Također, mjeren je promjer na način da je promjerka pozicionirana deset centimetara ispod i iznad stvarne prsne visine, zatim sa krakovima promjerke odmaknutim od debla, s normalnim i jačim pritiskom na krakove te izmjera promjera stabla sa krakovima promjerke okrenutim prema gore radi lakšeg očitanja vrijednosti. Rezultati su pokazali da je razlika između dva unakrsna promjera (eliptičnost stabla) veća nego pogreška izmjere promjera pri subjektivnoj procjeni prsne visine. Također, izmjera provedena ispod i iznad stvarne prsne visine daje statistički značajnu pozitivnu odnosno negativnu vrijednost prsnog promjera u odnosu na stvarnu. Kod krakova odmaknutih od debla dobivene su očekivane niže vrijednosti prsnog promjera kao i kod izmjere sa krakovima okrenutim prema gore. Utvrđene su i razlike u izmjeri promjera između samih mjeritelja. Obzirom da je prsni promjer stabla osnova za procjenu volumena pojedinačnog stabla i sastojine, iz svega spomenutog jasno je da pogreške pri izmjeri prsnog promjera, bile one uzrokovane nepažnjom mjeritelja ili metodološke, mogu imati značajan utjecaj na dobivene rezultate., A tree diameter at breast height (dbh) is a basic variable measured in forest inventory. Generally, it is measured with calipers whose arms have to be perpendicular to the beam. Therefore, caliper has to be rectified before measurement. Measurement should be performed in the way that caliper itself is perpendicular to the tree stem with arms and beam touching the tree without applying too much pressure to caliper arms. Measurer mistakes and failing to follow standard measurement procedures lead to errors that reflect in all inventory results (basal area, stand volume). Experience gathered while working with students and colleagues in practice, showed that measurement procedures sometimes significantly depart from required. Therefore, the aim of this research was to quantify and analyze known and observed dbh measurement errors.For that purpose two sites in Zagreb Training and Forest research center were selected: one site in area of lowland oak and hornbeam forest stand and another in mountain area with mixed fir and beech forest. Total 282 trees (74 Pedunculate oak, 56 Common hornbeam, 76 Silver fir and 76 Common beech) in wide diameter range were measured. (Table 1). All selected trees were marked with a number before measurement.On both research plots three measurers performed following diameter measurements using Haglof Mantax caliper: crosswise diameters at self-estimated breast height with (1a, 1b), crosswise diameters at marked breast height (2a, 2b), 10 cm above (3a) and 10 cm under the marked breast height (3b), at marked breast height point with caliper beam held apart from tree and normal pressure on the caliper arms (4a) and higher pressure on the caliper arms (4b) and caliper beam on marked point with caliper tips facing up (5a). Measurement group consisted of two measurers. One measurer preformed measurement and other was writing the data. Since measurers height can affect the placement of the calipers on the tree, so position of breast height of 1,3m was determined using measuring tape before beginning of measurement for each measurer. Marking of breast height point on the tree was made after measurement with self-estimated breast height. Collected data were analyzed using t-test and ANOVA with 0,05 significance level.Results show that average differences between two crosswise diameter measurements at self estimated breast height are statistically significant for hornbeam (average difference 1 cm) and beech (average 1,7 cm). Fir and oak had less differences (up to 0,7cm) that were not proven statistically significant. (Table 2).At marked breast height differences of crosswise measurements are as well statistically significant for hornbeam and beech. (Table 3). Comparison between average diameter difference at self-estimated and marked breast height show statistically significant difference for oak and beech. Negative average values for all measured species suggest that measurers usually slightly overestimated breast height (Table 4). According to Figure 1 it is visible that crosswise diameter differences are mostly within ±2-3 cm (50% difference). Certain trees show difference up to 15 cm in crosswise diameters. At the same time, diameter differences between self-estimated and marked breast height are smaller than crosswise diameter difference. Figure 2 shows that there is almost no trees which are not elliptical with fir having the smallest values.Diameter measured 10 cm under marked breast height expectedly resulted in statistically significant higher values for all tree species with 0,49 cm on average (Figure 4), and diameters measured 10 cm above marked breast height resulted in lower values being statistically significant for oak, beech and fir (Figure 5). The biggest difference is for oak trees.When caliper beam was held apart from tree and normal pressure on caliper arms applied, results were -0,12 to -0,26 cm lower and statistically significant compared to readings at correct position (caliper beam on the tree). The similar results were achieved with stronger pressure on the arms but with higher negative values, as expected.Measurement with arm tips facing up resulted with statistically significant lower average diameter reading for all measured tree species (Table 9). Moreover, Figure 4 shows that in comparison to diameter measured on marked breast height readings on the caliper scale were in range between -1,5 to +0,5cm with extremes ranging from -4 to +2cm respectively. Differences between measurers were observed on self-estimated breast height and for crosswise diameters on marked breast height. Table 10 and Figure 5 show that diameter differences between measurer 1 and other two measurers have proven to be statistically significant for self-estimated breast height of fir and beech trees (forest stand on sloping ground) where measurer 1 in average measured smaller diameters. Further, with diameters measured on marked breast height, differences were significant between measurer 3 and other two measurers in the way that measurer 3 on average measured larger diameters (Table 11 and Figure 6)Diameter measurement is the basis for volume estimation of individual trees and stand as well. Therefore, measurement errors have impact on volume estimation, so measurement is subjected to control and sometimes allowable measurement departures are prescribed. Omule (1980) mentions that in Columbia Forest Service allowable errors of 1% for dbh is allowed and Melson et al. (2002) states that allowable dbh errors are ±0,25 cm for trees from 12,5 to 50 cm, ±0,5 cm for trees from 50-100 cm and 0,75 cm for treesfrom 100-150 cm dbh. Measurer responsibility is to perform the measurement according to the rules and with highest possible precision.As the results show, differences in diameters can be a result of eliptical trees (Table 2, 3 and Figure 1). On tree level, differences sometimes reach 30% of tree diameter (Figure 1). With increase of tree diameter the difference between two crosswise diameters increases as well (Figure 3). Also, measurement under or above actual beast height results in statistically significant positive or negative diameter values.Results based on measured sample trees show that hornbeam and beech breast height measurement gives a significant difference in crosswise diameters as a result of sloping ground and geographic orientation. Turning the caliper beam towards the plot center can cancel out these measurement errors assuming an adequate sample size. Furthermore, on trees that are to be cut, the breast height should be marked (on the upper side of the slope). In this way measurement error for a single tree level would be reduced. Finally, this research points out the importance of following correct procedures while tree diameter measurement in order to minimize measurement errors which can affect accuracy of measured data.

In this paper both envelope approach and morphological filters for characterisation of surface textures were proposed, applied and thoroughly examined. Obtained results were compared with those received after appliance of commonly-used algorithms. The effect of appliance of proposed procedures on surface topography parameters (from ISO 25178 standard) was taken into consideration. The following types of surface textureswere assessed: two-process plateau-honed cylinder liners, plateau-honed cylinder liners with additionally burnished dimples, turned piston skirts, grinded and/or isotropic topographies. It was assumed that envelope characteristics (envelope filtration) can provide results useful for assessments of deep and/or wide oil-reservoirs especially when they are edge located. Moreover, some near-valley areas of surface texture details can be less distorted when envelope filtering is accomplished. It was also found that closing and/or opening envelope filtration can be valuable for reduction of some surface topography measurement errors.

Subject and Purpose. The article is devoted to the problem of precision radar measurements of target position data when a low-altitude target is above a rough sea. In these circumstances, the thermal noise of the radar receiver and the sea clutter are picked up by the radar antenna in parallel with the target useful signal and are factors affecting measurement accuracy. A particular challenge is the target elevation measurement. Methods and Methodology. A number of methods are known to significantly improve the measurement accuracy. The root-MUSIC method is among them, and the present paper examines a possibility to improve its performance due to multi-frequency measurements. The study is conducted by means of computer simulation using three-frequency X-band radar at the typical conditions: the path length is 2000 m, the antenna array height above the sea level is 12 m, the target angle of altitude is 0.2 to 0.5°. The multi-frequency measurement performance is evaluated by comparison with the single-frequency results obtained in the identical conditions with various sea clutter levels and different thermal noise figures in radar reception channels. Results. A preliminary analysis has been given to the measurement error distribution during conventional single-frequency measurements through different phases of the interference field structure of the received signal. It has proved the multi-frequency mode of operation as a means for the error reduction in target elevation measurements. The measurement error dependences on target elevation angles were studied with various real-valued frequency separations. Based on three particular estimates at each of the operating frequencies, an algorithm of the generalized estimation of the elevation angle has been developed and tested. An operating frequency separation to keep measuring errors to a minimum has been justified. Conclusion. It has been shown that a simultaneous use of three operating frequencies can reduce measurement errors by no less than 20...40% compared with the operation at a single frequency.

На основі методів вимірювань запропоноване технічне завдання на розробку методики вимірювань просторових параметрів ходи, яка використовується при біомеханічних дослідженнях руху людини в нормі і при патології опорно-рухової та інших систем організму людини. Визначена похибка вимірювань, що складається з трьох окремих похибок: інструментальної, методичної та нестабільності вимірювальних параметрів шагу. В статті запропоновано технологію вимірювань, їх підрахунок та побудовано схему вимірів. Завдяки подібній системі можна побудувати засоби визначення вимірювань просторових параметрів кроку. В подальшому цю методику можна реалізація в програмному середовищі, що забезпечить універсальність та простоту подальшої модифікації алгоритмів роботи. Тематика статті стосується наукових досліджень у сфері охорони здоров’я та медичних технологій. On the basis of measurement methods, a technical specification for the development of a technique for measuring the spatial parameters of gait is proposed, which is used in biomechanical studies of human movement in normal and pathology of the musculoskeletal and other systems of the human body. Measurement error, consisting of three individual errors: instrumental, methodological and instability of step measurement parameters, is determined. In the article the technology of measurements, their calculation and the scheme of measurements are offered. With this system, you can build tools for determining the measurements of the spatial parameters of the step. In the future, this technique can be implemented in a software environment, which will provide versatility and ease of further modification of the algorithms. The subject of the article is related to scientific research in the field of health care and medical technologies. На основе методов измерений предложено техническое задание на разработку методики измерений пространственных параметров походки, которая используется при биомеханических исследованиях движения человека в норме и при патологии опорно-двигательной и других систем организма человека. Определена погрешность измерений, состоящая из трех отдельных погрешностей: инструментальной, методической и нестабильности измерительных параметров шага. В статье предложена технология измерений, их подсчет и построена схема измерений. Благодаря подобной системе можно построить средства определения измерений пространственных параметров шага. В дальнейшем эту методику можно реализация в программной среде, что обеспечит универсальность и простоту дальнейшей модификации алгоритмов работы. Тематика статьи касается научных исследований в сфере здравоохранения и медицинских технологий.

International audience; Proxy Means Testing (PMT) is a popular method to target the poor in developing countries. PMT usually relies on survey-based consumption data and assumes random measurement errors – an assumption that has been challenged by recent literature. Using a survey experiment conducted in Tanzania, this paper brings causal evidence on the impact of non-random errors on PMT performances. Results show that non-random errors bias the coefficients from PMT models, resulting in a 5 to 27 per cent reduction in PMT predictive performances. Moreover, non-random errors induce a 10 to 34 per cent increase in the incidence of targeting errors when poverty is defined in absolute terms. More reassuringly, impacts on the ranking of households are smaller and essentially non-significant. Taken together, these results indicate that PMT performances are quite vulnerable to non-random errors when the objective is to target absolutely poor households, but remain largely unaffected when the objective is to target a fixed share of the population.

Autocorrelation and measurement errors have a negative effect on the performance of any monitoring scheme; therefore, more efficient monitoring schemes are required to monitor such special processes. Hence, in this paper, the use of improved synthetic and runs-rules X̅ schemes with an embedded variable sample size and sampling interval (VSSI) approach to efficiently monitor the mean of a process under the combined effect of autocorrelation and measurement errors is proposed. These new monitoring schemes incorporate a linearly covariate error model with a constant standard deviation and a first-order autoregressive model to the variability of this special process in order to account for measurement errors and autocorrelation, respectively. Moreover, in order to evaluate the zero- and steady-state run-length properties of the proposed monitoring schemes, a dedicated Markov chain matrix that takes into account the following is constructed: (i) VSSI approach, (ii) improved charting regions design of the synthetic and runs-rules X̅ schemes, and (iii) the combined effect of autocorrelation and measurement errors. Also, the probability elements of the Markov chain matrix incorporate two special sampling methods that aid in the reduction of the negative effect of autocorrelation and measurement errors. A real life example is given to illustrate the implementation of the proposed monitoring schemes.

Cylindrical vibratory gyroscope is a kind of mode-matched gyros, and the frequency split would affect its sensitivity significantly. Frequency tuning is a major method to decrease the split. In the process of frequency tuning, the natural frequency should be measured firstly, and the measurement error is one of the decisive factor of tuning accuracy. Due to the measurement error of frequency is Normal Distribution, its effects on frequency tuning are studied by theoretical and simulation analysis from the statistical aspect. Firstly, the influence of frequency splitting on gyro sensitivity is studied, which shows the importance of reducing frequency splitting. Then the effect of different measuring accuracy on the measured value is analyzed. Thirdly, the tuning error that caused by the measurement error is researched in the process of trimming, and the tuning error is derived by theoretical analysis. Simulation and experiment results under different measurement error exemplify the value of tuning error. Finally, the optimal measurement accuracy that ensures achieving tuning accuracy is discussed.

Remaining useful life (RUL) prediction plays a crucial role in prognostics and health management (PHM). Recently, the adaptive model-based RUL prediction, which is proven effective and flexible, has gained considerable attention. Most research on adaptive degradation models focuses on the Wiener process. However, since the degradation process of some products is accumulated and irreversible, the inverse Gaussian (IG) process that can describe monotonic degradation paths is a natural choice for degradation modelling. This article proposes a nonlinear adaptive IG process along with the corresponding state space model considering measurement errors. Then, an improved particle filtering algorithm is presented to update the degradation parameter and estimate the underlying degradation state under the nonGaussian assumptions in the state space model. The RUL prediction depending on historical degradation data is derived based on the results of particle methods, which can avoid high-dimensional integration. In addition, the expectation-maximization (EM) algorithm combined with an improved particle smoother is developed to estimate and adaptively update the unknown model parameters once newly monitored degradation data become available. Finally, this article concludes with a simulation study and a case application to demonstrate the applicability and superiority of the proposed method.

In statistical process monitoring, the usual assumption when designing monitoring schemes is that process parameters are known and have perfect measurements with independent and identically distributed observations. However, in real-life situation, these assumptions rarely hold. Hence, in this paper, the Phase II performance of the homogenously weighted moving average (HWMA) $\bar {X}$ monitoring scheme under the combined effect of autocorrelation and measurement errors is investigated when the unknown process parameters are estimated from an in-control Phase I dataset. Two models are considered, i.e. the first-order autoregressive model for within-sample autocorrelation and the linear covariate model for (constant and linearly increasing variance) measurement system error. Sampling strategies based on skipping some observations as well as mixing different subgroup samples and taking multiple measurements are implemented to reduce the negative effect of autocorrelation and measurement errors. Since the latter sampling strategies incur costs, as an alternative, increasing the slope coefficient of the linear covariate model compensate the negative effect of measurement errors. The new HWMA $\bar {X}$ scheme is shown to have some interesting detection abilities as compared to its competitors. A real-life example is used to illustrate the implementation of the proposed monitoring scheme.

This paper investigates the performance of the coefficient of variation chart in the presence of measurement errors for finite production horizon. We study a two-sided Shewhart coefficient of variation chart with measurement errors for detecting both increase and decrease in the coefficient of variation for short run processes using an error model with linear covariate. The performance of the coefficient of variation chart is evaluated by the truncated average run length and the expected value of the truncated average run length. The numerical results indicate that the precision error and the accuracy error have negative effect of the measurement errors on the performance of the coefficient of variation chart. In addition, the constant coefficient B in the linear covariate error model reduces the negative effect of the measurement errors on the performance of the coefficient of variation chart. However, taking multiple measurements per item in each sample is not an effective method to enhance the performance of the coefficient of variation chart. An example is provided to illustrate the implementation of the coefficient of variation chart. In addition, the economic criterion is also added to study the effect of measurement errors on the expected inspection cost. The result shows that an increase in the precision error reduces the expected inspection cost.

The exact determination of the process zone temperature can be considered as an increasingly important role in the control and monitoring of the friction stir welding process (FSW). At present, temperature measurement is carried out with the aid of a temperature sensor integrated into the tool (usually thermocouples). Since these cannot be attached directly to the joining area, heat dissipation within the tool and to the environment cause measurement deviations as well as a time delay in the temperature measurement. The article describes a process and the challenges that arise in this process, how a direct temperature measurement during the process can be achieved by exploiting the thermoelectric effect between tool and workpiece, without changing the tool by introducing additional temperature sensors.

Die Anzahl an Photovoltaik-Anlagen und Wärmepumpen wird in den nächsten Jahren deutlich ansteigen. Folglich wird die Überwachung der von diesen Anlagen produzierten und verbrauchten Leistungen immer wichtiger. Messfehler können jedoch die Datenqualität deutlich verschlechtern. In dieser Diplomarbeit werden Methoden, basierend auf physikalischen Modellen, entwickelt, um diese Messfehler mittels eines selbst entwickelten Python-Programms zu finden und durch berechnete Leistungswerte zu ersetzen. Die gemessenen Leistungswerte werden verwendet, um die Nennleistung und Ausrichtung der Anlagen abschätzen zu können. Für die benötigten Strahlungs- und Wetterdaten werden Online-Datenbanken genutzt. Bei den Wärmepumpen wird bei fehlenden Messwerten ein für den betrachteten Tag typisches Lastprofil, je nach Außentemperatur, verwendet. Das Ziel dieser Arbeit ist es, die verbesserten Daten auf einer Homepage für die Besitzer_innen der Anlagen bereitzustellen. Die Auswertungen zeigen, dass die Berechnungen der Leistungswerte für die Photovoltaik-Anlagen, nach dem Analysieren, Anpassen und Verbessern des Photovoltaik-Modells, gute Approximationen sind. Ein Vergleich zwischen berechneten und richtig gemessenen Leistungswerten ergab jedoch vereinzelt größere Abweichungen aufgrund einiger Unsicherheiten. Zu diesen Unsicherheiten zählen vor allem, dass die Strahlungsdaten nicht direkt vor Ort gemessen werden. Zudem sind die Modulnennleistungen und Ausrichtungen nur geschätzte Werte und eine Betrachtung von Schattenverlusten ist aufgrund fehlender Informationen nicht möglich. Die Analyse der Lastprofile der Wärmepumpen ergibt, dass nur die Außentemperatur einen wesentlichen Einfluss auf die verbrauchte Leistung hat. Je mehr Messdaten von einer Wärmepumpe in den betrachteten Außentemperaturbereichen vorliegen, desto besser kann ein typisches Lastprofil gefunden werden., In order to cope with the climate crisis, the number of photovoltaic plants and heat pumps will increase in the coming years. Consequently, the surveillance of their energetic services is becoming increasingly important. A major problem are measurement errors because they are associated with reduced data quality. This diploma thesis is dedicated to the usage of methods, based on physical models, to find these errors. Furthermore, the errors were replaced by power values calculated with a self developed python-programm. The nominal power and orientation of the photovoltaic plants are estimated by the measured power values and online databases are used for radiation and weather data. In addition, missing heat pump power values were replaced by a typical load profile based on outside temperatures. The aim of this work is, to provide improved data for the photovoltaic and heat pump owners. The results have shown that the power value calculations for the photovoltaic plants are successful, after the photovoltaic-model was analyzed, adapted and improved. A comparison of the calculated and correctly measured power values, revealed that occasionally large deviations occurred due to some insecurities. One major problem is that the radiation data could not be measured on site and the nominal power and orientation of the photovoltaic plants are estimated values. Additionally, shadow losses can not be considered because of a lack of local information. Analysis of heat pump load profiles showed, that the power consumption strongly depends on the outside temperature. More heat pump measured values concerning the different outside temperature ranges led to an improved load profile.

Small Area Estimation erlaubt die Schätzung regionaler Indikatoren anhand kleiner Stichproben. Hierfür werden Survey-Daten mehrerer Regionen in statistischen Modellen kombiniert. Aufgrund der Digitalisierung der Gesellschaft entstehen immer mehr zusätzliche Datenquellen, wie etwa Website- und Social-Media-Daten, welche die Modelle weiter verbessern könnten. Bei der Verwendung dieser Daten ist jedoch zu beachten, dass ihre Eigenschaften sich deutlich von Stichprobendaten unterscheiden. Sie sind unter anderem mit einer generellen Unsicherheit assoziiert, welche sich nicht quantifizieren lässt. Klassische Schätzverfahren können dies nicht antizipieren, was zu ungenauen Ergebnissen führt. Dieser Artikel zeigt, dass die Schätzung regionaler Indikatoren gegen Unsicherheit mithilfe von Regularisierung robustifiziert werden kann. Small area estimation facilitates the estimation of regional indicators from small samples. This requires the combination of survey data from multiple regions in statistical models. Due to the rapid digitalisation of public life, more and more additional data sources arise, such as website and social media data. These data sources can further improve the models. However, researchers must be aware that these data have fundamentally different properties than sample data. They are often associated with a general uncertainty that cannot be quantified. Classical estimators cannot account for this, which leads to inaccurate estimates. This paper demonstrates that regularisation is a useful tool to robustify small area estimates against uncertainty.

The mixed-demand model allows for very flexible specification of what should be considered endogenous and exogenous in demand system estimation. This paper introduces a revealed preference framework to analyze the mixed-demand model. The proposed methods can be used to test whether observed data (with measurement errors) are consistent with the mixed-demand model and calculate goodness-of-fit measures. The framework is purely non-parametric in the sense that it does not require any functional form assumptions on the direct or indirect utility functions. The framework is applied to demand data for food and provides the first nonparametric empirical analysis of the mixed-demand model.

Agile synthetic aperture radar (SAR) platforms such as car-borne and UAV-borne SAR systems require combined inertial navigation systems (INS) and global navigation satellite systems (GNSS) to measure the radar sensor trajectories used for focusing and interferometric processing. Measurement inaccuracies from INS/GNSS systems lead to residual phase errors in the SAR products whose minimization is crucial to derive accurate topographic and deformation information. In this work, we analyze the impact of residual positioning errors on car-borne repeat-pass SAR interferometry at L-band for different INS/GNSS measurement configurations and for the typical car-borne acquisition geometry. The positioning errors are evaluated both during single SAR acquisitions with long integration times and between different acquisitions as a function of the distance of the radar platform from the GNSS reference stations. We show the reduction of interferometric phase errors achievable by additionally using a GNSS receiver mounted in the vicinity of the SAR platform as compared to remote reference stations of the national network of permanent GNSS receivers. Test results obtained in a controlled setup with a rail-based SAR system equipped with a navigation-grade INS/GNSS system show maximum repeat-pass trajectory errors on the order of 1–2 cm using a local GNSS reference station and up to 10–15 cm using the remote reference stations, leading to azimuth and range phase trends in the interferometric products., IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 15, ISSN:1939-1404, ISSN:2151-1535

I denna studie så ville AstraZenecas dispenseringsfunktion, som arbetar med att finfördelamaterial från sin bulkförpackning undersöka hur och med vilka frekvenser kalibreringar ochfunktionskontroller för deras vågar bör göras. Detta i hopp om att harmonisera en uppdateradoch förbättrad standard mellan siterna Gärtuna och Snäckviken. Standarder inom mätningslära är inget som läkemedelsföretag själva investerar resurser i, utanföljer det som farmakopéerna världen över publicerar i sina böcker. Däri återfinns allt som kantänkas behövas för tillverkning och utformning av läkemedel. Syftet med att kalibrera ochgenomföra funktionskontroller så ofta som AstraZeneca gör i dagsläget är för att vara förenligamed regelverk för att bli godkända vid inspektioner. Däremot finns risken attfunktionskontroller och kalibreringar genomförs med högre eller lägre frekvens än vad de bordegöras samt att irrelevanta tester vid dessa kontroller får alltför hög prioritering för att påvisa envågs förmåga att fungera som den ska. För att undersöka detta genomfördes det en kartläggning av hur AstraZeneca arbetar idag medvågkalibreringar och funktionskontroller. Denna behandlade både hur arbetet sker internt viaegna funktioner, men också externt via vågtillverkaren och valideringsfirmor. Dennainformation tillsammans med vad farmakopéerna och vågtillverkaren själva påstår är korrektarbetssätt blev ett tydligt och effektivt sätt att sålla bort överflödiga och i vissa fall irrelevantametoder som används på AstraZeneca idag. Utöver dessa finns det fenomen såsommätosäkerhet och störningselement som kan påverka varje vägning till den grad där resultatenär fullständigt missvisande, och i läkemedelsindustrins fall är dessa oacceptabla. Vid studiens slut kunde flera systematiska brister identifieras och rekommendationer för attmotverka eller lösa dessa gavs i enlighet med syftet om att nå god praxis för våganvändningen isamband med dispenseringsprocessen. Framtida förbättringsarbeten hade förenklats ocheffektiviserats till stor del om en fullständig digitalisering och övervakning avstörningselementen möjliggörs. In this study that was commissioned by AstraZeneca's dispensing function that worksmainly by sub-dividing materials from its bulk packaging. They wanted to investigatehow and with what frequencies calibrations and routine testing for their balances shouldbe performed. This, with the purpose of harmonizing an updated and improvedstandard between the sites Gärtuna and Snäckviken. Measurement theory standards are not something that pharmaceutical companiesthemselves invest resources in but rather follow what pharmacopoeias around the worldpublish in their books. The books contain everything that may be needed for themanufacturing and design of medicines. The purpose of calibrating and performingroutine testing as often as AstraZeneca does today is to comply with regulations to beapproved during inspections. However, there is a risk that routine testing andcalibrations are performed at a higher or lower frequency than they should be, and thatirrelevant tests at these routine tests are given too high a priority to demonstrate abalances ability to function properly. To investigate this, a survey was conducted of how AstraZeneca works today withbalance calibrations and routine testing. The survey considered both how the work isdone internally via AstraZeneca’s own employees, but also externally via the balancemanufacturer and validation companies. This information, in combination with whatthe pharmacopoeias and the balance manufacturer themselves claim is the correct wayof operating, became a clear and effective way of sifting away superfluous and in somecases irrelevant methods used in AstraZeneca today. In addition to these, there arephenomena such as measurement uncertainty and external disturbance elements thatcan affect any weighing to the extent that the results are completely misleading, and inthe case of the pharmaceutical industry, such results would be unacceptable. At the end of the study, several systematic flaws or shortcomings could be identified andrecommendations to counteract or solve these were given in accordance with the aim ofachieving best practice for the use of balances in connection with the dispensingprocess. Future improvement work would have been greatly simplified and streamlinedif complete digitization and monitoring of the disturbance elements were made possible.

Lidar is an important component of the perception suite for automated systems. The effects of vibration on lidar point clouds are mostly unknown, despite the lidar’s wide adaption and usual application under conditions where vibration occurs frequently. In this study, we performed controlled vibration tests from 6 to 2000 Hz at 9 and 12 m/s 2 in vertical direction on the automotive lidar OS1-64 by Ouster. An information loss emerged which is mostly independent from frequency and acceleration. The loss of points is randomly distributed and does not correlate with range, intensity, or ring number (the horizontal line of the rotating lidar unit). The resonance frequency of 1426 Hz proved to be unproblematic as no pronounced negative effects on the point cloud could be identified. For vibration detection, the internal Inertial Measurement Unit (IMU) of the OS1-64 is accurate and sufficient for vibrations up to 50 Hz. Above 50 Hz, external IMUs would be required for vibration detection. Counting the number of points on a target close to the edges was investigated as an exemplary way to detect vibration purely based on the point cloud, i.e., independent of the lidar’s IMU. Version of record