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Fault location algorithms for transmission lines use the parameters of the transmission line to locate faults after the faults have occurred along the line. Although these parameters can be estimated by the phasor measurement units (PMUs) at the terminal(s) of the transmission line continuously, the uncertainty in the measurements will give rise to stochastic errors in the measured values. Thus, the uncertainty in measurements definitely influences the estimations of the parameters of the transmission line, which, in turn, influences the results of fault location algorithms. Inaccurate results of fault location algorithms may lead to costly maintenance fees and prolonged outage time. Therefore, in this article, we estimate the parameters of the transmission line considering the uncertainty in the measurements so that a more accurate fault location can be derived. The uncertainty in the measurements will be modeled as a stochastic distribution, and the maximum likelihood estimation (MLE) method will be adopted to reduce the uncertainty in the measurements. In addition, as an illustration, the telegrapher’s equations will be used to calculate the parameters of the transmission line, and the two-terminal positive sequence network fault location algorithm will be used to locate the fault. In a simulation, a case study of a real-life transmission line the influence of the uncertainty in the measurements on the transmission line parameter estimations and the effectiveness of the MLE method for estimations are simulated and analyzed. The results show that the influence of the uncertainty in the measurements on the positive sequence network fault location algorithm should not be neglected and that the proposed method is very effective in significantly reducing the influence of the uncertainty in the measurements. Note to Practitioners —The objective of this article is to address the significant effects of inaccuracies in the measurements for fault location determination in transmission lines in power systems. These inaccuracies increase the cost and duration of the search process for the actual fault location, and they, thus, also enlarge the outage duration and reduce the power system reliability. This article aims to analyze and reduce the influence of the uncertainties in the measurements in order to obtain a much more accurate fault location estimate when a fault has occurred along the transmission line. One of the key contributions of this article is the development of a model for the uncertainties in the measurements based on a confidence level and deviation bounds; this model can then be used if the information on the distributions of the uncertainties in the measurements is not available. Another key contribution is a maximum likelihood estimation method to estimate line parameters more accurately and consequently to reduce the influence of the uncertainties in the measurements on the fault location estimate.

Due to the complexity of the ice-structure interaction, the knowledge about the ice-induced loads on a ship hull has been gained from full-scale measurements. As the instrumentation of the hull for the measurements is expensive, the extension is concerned at the planning phase. However, a narrow instrumentation can cause an error in the measurements, as the response of the adjacent frames with respect to the observed frame is not known. Thus, this paper studies the differences between loads measured from one or several frames on board S.A. Agulhas II. The difference results from the ability of the structure to transport loading internally. The results show that when the loads affect only an individual frame, the instrumentations give similar results. However, the difference increases with the load length and the loading that is determined can be 15% higher for one frame instrumentation for a structure similar to the aft shoulder of S.A. Agulhas II. Furthermore, the difference in the mean value and standard deviation of the measurement time histories can be up to 10%. The study presents a new efficient method to obtain a rough estimate of the possible difference in the measured results between extensive and narrow instrumentation.

Att kunna simulera en AOD-process (Argon, OxygenandDecarburization) är i dagsläget möjligt med hjälp av en programvara. En sådan programvara används till utbildning och forskning för utveckling av rostfritt stål. Kobolde & Partners AB är ett företag som äger en sådan programvara. I detta projekt byggs programmet ut för att ge användare möjlighet att simulera en AOD-process med osäkerhet i mätdata. Genom detta kan forskare få ökad förståelse hur processens mätresultat skiljer sig med osäkerhet i mätdata., Being able to simulate an AOD process (Argon, Oxygen andDecarburization) is possible nowadays with help of software. This kind ofsoftware is used for education andresearch for development of stainless steel. Kobolde & Partners AB is a company that owns this kind of software. This project will further develop this software to enable users to simulate an AOD process with uncertainty in measurement. This allows scientist to get more knowledge how a process measurement results

This paper deals with possible ways of obtaining expanded and combined uncertainty in measurements for four types of GM counters with a same counter?s tube, in cases when the contributors of these uncertainties are cosmic background radiation and induced overvoltage phenomena. Nowadays, as a consequence of electromagnetic radiation, the latter phenomenon is especially marked in urban environments. Based on experimental results obtained, it has been established that the uncertainties of an influenced random variable ?number of pulses from background radiation? and ?number of pulses induced by overvoltage? depend on the technological solution of the counter?s reading system and contribute in different ways to the expanded and combined uncertainty in measurements of the applied types of GM counters.

O conhecimento da incerteza de uma medida é crucial para obter conclusões a partir de resultados experimentais. Erros aleatórios, comuns em experimentos, produzem uma distribuição dos valores medidos que segue o formato gaussiano. Neste trabalho desenvolvemos uma montagem baseada no fenômeno de queda livre para auxiliar na ilustração do conceito de incerteza em medidas. Os tempos de queda de um objeto foram obtidos automaticamente pela placa Arduino e exibidos na forma de um histograma na tela do computador. A visualização do histograma foi feita em tempo real e permitiu verificar o aparecimento do aspecto gaussiano à medida que repetições do experimento eram realizadas. The knowledge of the uncertainty of a measurement is crucial to draw conclusions from experimental results. Random errors are common in experiments and they produce a distribution of measured values that follows the Gaussian shape. In this work, we developed an apparatus based on the free fall phenomenon to assist in the illustration of the concept of uncertainty in measurements. The free fall time of an object has been obtained automatically by the Arduino board and displayed as a histogram on the computer screen. The visualization of the histogram was produced in real time and allowed to check the appearance of the Gaussian shape as the experiment was repeated.

This paper discusses the influence of radiation energy and angle of incidence as possible sources of uncertainties in measurements performed by GM counters. Based on the detection efficiency of GM counters, it has been concluded that the energy of incident radiation does not contribute to the overall uncertainty. The angle of incident radiation does contribute to overall uncertainty, but only in the case of gamma radiation detection. In that case, the uncertainty should be determined by using geometrical probability.