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Many bridge structures are facing the nature disasters such as earthquakes and floods due to the fast global climate change. Since bridges are the important pivots of traffic and the damage of bridges can cause the severe cost of human life and property. These nature disasters cause lots of bridge collapse or destruction and thus endanger our daily life. Bridge scour is the main cause for bridge failure...
The analysis of measurement uncertainty is necessary in every measurement process. In this paper, we suggest an approach to categorize and model the dominant sources of uncertainty and study the probabilistic propagation of the uncertainties in a 3D inspection using laser line scanners. To each point of the measurement point cloud, we associate a covariance matrix describing the corresponding dispersion...
Fault diagnosis plays a significant role to ensure transmission efficiency and reliability of gearboxes. Considering the modulation feature of gearbox vibration signals, a demodulation analysis method based on variational mode decomposition (VMD) is proposed. Firstly, a multi-component signal is decomposed into a series of intrinsic mode functions (IMFs) via VMD to reduce the effect of noise and satisfy...
Direct-reading instruments which can provide real-time PM2.5 measurements are widely used because they are cheap and easy to use. However, these direct-reading instruments suffer from zero drift problems and have to be calibrated before use. Direct-reading instruments based on average value measurement can't give a correct assessment of PM2.5 mass concentrations when particles' diameter changes greatly...
Nowadays, the presence of nonlinear devices cannot be neglected either for their growing numbers or for their effect on the distribution network. In particular, these devices will produce relevant harmonics, which can cause problems such as increase of losses, over-heating in the power transformer malfunction of the circuit switch and, generally, an untimely aging process of connected devices. As...
This paper investigates defects in photovoltaic cells and panels which cause notable losses in output performances. Here, the focus lies on the impact of hairline cracks which result in a remarkable drop of the available output current and, thus, the available output power. Firstly, samples were characterised with the help of synchronized thermography (ST) in order to localise and analyse the defects...
In this paper the accuracies of synchrophasor estimates obtained by two real-valued Taylor-based Weighted Least Squares (TWLS) algorithms are compared when harmonically distorted sine-waves are analyzed. Both algorithms estimate the waveform frequency runtime and only the effect of 2nd harmonic on returned phasor estimates is considered. The first algorithm, called TWLS-RH(2), applies the classical...
Wind turbine is driven by natural wind, thus the vibration signal of gearbox is influenced and performs with nature of non-stationary and noisy. In order to analyze the variable speed signal, time-frequency representation is introduced as a powerful tool. The synchrosqueezing transform is a useful time-frequency representation method in many situation but can not restrain noise in high noise background...
Monitoring systems in distribution may account on sparse measurement infrastructure and therefore should be supported by robust state estimation techniques. The uncertainty of the estimated states depends, also, on the speed at which voltage magnitude and phase angle may change. In fact distribution systems include several components that in presence of high voltage oscillation react with variations...
Several applications require a distributed measurement system able to measure the same or different parameters at different points in a wide area. In recent years, a wide variety of solutions have been proposed for the remote measurement and data transmission. In this paper an architecture of a real-time energy management is presented. It provides several Smart Meters, that continuously monitor connected...
Applications like electrical capacitance tomography (ECT) rely on capacitance measurements with a good signal to noise ratio. In Low-Z measurement circuitry the measurement frequency can be directly used to increase the signal amplitudes. Simple front-end circuit models consider the behavior of all components by means of lumped capacitors. However, for higher system frequencies and long instrumentation...
A large number of electric vehicles (EVs) connected to the grid increase the load of the grid, which may lead to the problems, such as overload, frequency violation and voltage violation. However, the EVs have potential for providing services for the grid, such as voltage regulation and frequency regulation. In this paper, we use the EVs to regulate the voltage of the smart grid and propose an algorithm...
A label-free non-invasive sensing system for detection of C-terminal telopeptide of type-I collagen (CTX-I) has been developed in order to detect bone loss at an early stage, by Electrochemical Impedance Spectroscopy (EIS). A planar interdigital sensor was functionalized by immobilizing streptavidin agarose on the sensing area of the sensor to introduce selectivity for the antigen-antibody solution...
The impact of photovoltaic (PV) energy has grown rapidly in the last years; both the scientific community and the industry have focused its attention on improving the efficiency of PV modules while decreasing their cost. In order to ensure best performance, PV panels have to work at the Maximum Power Point (MPP) of their V-I curve. As the MPP depends on the environmental conditions, an algorithm to...
This paper deals with a noninvasive calibration system of current transformers in electrical power systems. The proposed system requires precise current sensors located on the primary and the secondary side of the transformer. Current sensors were designed as current transformers with a nanocrystalline magnetic core. The nanocrystalline magnetic materials can reach higher permeability and sufficiently...
Feature selection is critical to the success of machine fault intelligent diagnosis. However, different feature extraction methods may lead to different diagnostic results. It increases the difficulty in feature selection as well as the diagnostic uncertainty. A deep belief network (DBN), composed of multiple layers of Restricted Boltzmann machine (RBM), is one of the typical deep learning methods,...
In order to improve the precision and anti-interference ability of traditional proton magnetometer, and provide reference basis for developing Overhauser magnetometer, a high precision proton magnetometer based on a multi-channel frequency measurement was designed. This paper introduces the basic principle of larmor precession effect, makes a detailed description about the signal disposal system and...
Propagation constant characterization plays a key role in various microwave measurement situations such as thru-reflect-line (TRL) calibration, interconnect characterization, fixture de-embedding and measurement of material properties. To differentiate the forward and backward propagating factors, sign-ambiguity problem of square-root searching is inevitable in the process of characterizing the eigenvalue...
Smart Grid (SG) can be defined as a modern electric power grid infrastructure for improved efficiency, reliability and safety, with smooth integration of renewable and alternative energy sources, through automated control and modern communications technologies. The increased need for more effective control on electrical power systems has led to the development and the increased research interest on...
A method for crosstalk detection and removal in multichannel time-of-arrival measurement systems is proposed. The method, based on low-complexity processing of cross-correlation results, is evaluated by numerical simulations and experimental characterization. Results show the capability to detect and remove crosstalk by processing the signals acquired by two mutually-interfering electrical channels...
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