The paper describes the recent development of a system for calibration of electrical instruments with harmonics measurement capability, such as revenue meters and power analyzers, under nonsinusoidal test conditions at National Research Council (NRC) Canada. The improvements implemented with respect to an earlier NRC calibration system are aimed at increasing the calibration accuracy in a wider frequency

A novel passive interface circuit with gain for nongenerating (active, i.e., excited/driven) sensors in differential or bridge configuration is presented. The circuit is very simple and consists of only one transformer in the output diagonal of the equivalent bridge configuration comprised of sensor(s), bridge completion impedances, and excitation source. It can be used with resistive, capacitive,

This article focuses on the characterization and architecture of a new mixed design approach to monolithic CMOS-silicon-photomultiplier (SiPM), where the mixed-signal circuitry as well as the logical concepts are implemented at the die level. The new architecture contains two key areas: 1) a method for sampling, filtering, and converting the electrical signal generated by the SiPM to the digital domain

With high temporal resolution demand under noise contamination, the travel time estimation for the pulse-echo is noticed in the acoustic logging instrument design. To this end, an intelligent ultrasonic logging system is built to collect borehole information, and a framework with domain adaptation theory is proposed. The modified maximum mean discrepancy minimization combined with spatial pyramid pooling

Electromagnetic induction imaging (EII) is an attractive imaging modality due to its contactless operation, low cost, and good penetration depth. To implement real-time imaging, in applications such as object tracking or functional biomedical imaging, fast data acquisition is required. To proceed toward this goal, in this article, we propose the use of a single coil for 3-D EII along with a fast inversion

Industrial process tomography (PT) possesses unique advantages in multiphase distribution imaging. Oil–gas–water three-phase distribution has coexisting high-impedance contrast and low-impedance contrast medium, possessing a challenge to traditional PT sensing technique. An original concept of multifrequency ultrasonic tomography (MFUT) is proposed, which reconstructs oil–gas–water three-phase distribution

The mercury–cadmium–tellurium (MCT) sensors are considered the ideal infrared detectors to equip the focal plane arrays (FPAs) of astronomical scientific missions. To tackle Europe to be self-sufficient on this technology and promote to reach the same maturity level attained by the current MCT sensors market leaders, the Astronomy European Infrared Detector (ASTEROID) project aims to provide Europe

The input data of photometric stereo have three dimensions: one photometric dimension of different lights and two spatial dimensions, i.e., rows and columns in the image coordinate. Recent deep-learning-based photometric stereo algorithms usually use 2-D/3-D convolutions to process the input with three dimensions. Assumptions that violate the natural characters of photometric stereo problem, e.g.,

Recently, indoor localization using a single receiver has received significant attention. Despite the improvement of this, developing an accurate and universal system is still heavily required. In this article, we design and implement BiLoc, a decimeter level indoor localization system with hybrid measurements of a distributed single receiver. Specifically, different from the existing single receiver-based

The fault diagnosis of the gearbox of wind turbines is a crucial task for wind turbine operation and maintenance. Although a convolutional neural network can extract the related information of adjacent sampling points using kernels, traditional deep learning methods have not leveraged related information from points with a large span of vibration signal data. In this article, a novel fast deep graph

The complex slip characteristics between the tracks and the terrain make it difficult to build an accurate model for intelligent tracked vehicles. Both the path planning and lateral control, however, are highly dependent on the accurate tracked vehicle model. To overcome the issue, a slip model based on the instantaneous centers of rotation (ICRs) of tracks and a dual-layer adaptive unscented Kalman

The permanent magnet sodium flowmeter (PMSF) without the bluff body installed on the large-diameter pipe in the fast reactors to measure the sodium coolant flow rate has to be calibrated in situ owing to the degradation of the magnetic field. Since the length of the magnetic field of the PMSF is limited in practical engineering applications, the characteristic between the cross correlation flow rate

The demodulation of mechanical oscillations is essential for the operation of micro- and nanometer-scale transducer systems, such as resonant MEMS mirrors and cantilever-based sensors. The use of external demodulators, such as lock-in amplifiers and spectrum analyzers is not always desired due to their large size, complexity, and cost. The method presented in this article enables simplified demodulation

In this article, we present a vector network analyzer (VNA)-based measurement scheme and setup to obtain repeatable phase spectrum measurements of 75–110-GHz modulated radio frequency (RF) signals. In order to remove the random phase contribution of sweeping local oscillator (LO) in harmonic downconversion, the LO signal is coupled out into an auxiliary measurement channel where its random phase at

With the development of Internet of Things (IoT), people’s demand for location-based services is increasingly urgent. Based on magnetometer, accelerometer, and rate gyro, i.e., MARG sensors, the position and attitude estimation methods such as complementary filter (CF), Kalman filter (KF), and their various modifications have been the research hot spot. However, the CF-based methods are empirical and

This article presents a standard field generation system with an antenna for the calibration of a Ka-band electric-field probe. We constructed a measurement system having capability of not only rotating the azimuth angle of the probe but also changing the separation distance between the antenna and the probe. As a result, the orientation and separation distance of the probe can be suggested for minimal

In the field of practical engineering, the moving least-squares (MLS) and moving total least-squares (MTLS) methods are widely used to approximate the measurement data. However, the fitting accuracy and robustness are affected inevitably by random errors and outliers, which results in distorted estimation. To solve this problem, we present an improved MTLS (IMTLS) method, in which a newly constructed

This article introduces a general-purpose framework aimed at capturing the elusive concept of quality of measurement information (MI), a critical issue for both researchers and practitioners when dealing with MI-enabled decision-making. The framework is a blueprint for the definition, assessment, communication, and improvement of MI quality, as analyzed through a set of general criteria, classified

We have evaluated a Josephson arbitrary waveform synthesizer (JAWS) in the voltage range from $1~\mu \text{V}$ to 1 mV at frequencies from 60 to 1000 Hz for the use in the calibration of lock-in amplifiers. The uncertainty contribution from the JAWS system is 45 nV for 1 mV at 1000 Hz and $k=2.0$ . We anticipate that the JAWS will help extend the lower voltage and frequency range of ac voltage metrology

Metering data from the advanced metering infrastructure can be used to find abnormal electricity behavior for the detection of electricity theft, which causes huge financial losses to electric companies every year. This article proposes an electricity theft detector using metering data based on extreme gradient boosting (XGBoost). The metering data are preprocessed, including recover missing and erroneous

The interruption of a three-phase induction motor (TIM) on production lines represents a high financial and operational cost. However, these machines are often exposed to mechanical and electrical failures that can cause unexpected stoppages. Among these failures, the voltage unbalance (VU) is a supply fault that can lead to winding wear, torque losses, overheating, and other side effects. In this

In order to eliminate the influence of parameter predefined caused by manual feature extraction, achieve fast feature extraction, and improve the recognition rate of fault diagnosis, a 2-D convolution neural network (CNN) method for fault diagnosis of conventional circuit breaker contact system is proposed. First, by introducing the data preprocessing method of continuous wavelet transform (CWT), the

We present the development of a novel smart ink pen instrumented with force and motion sensors designed for the quantitative and ecological assessment of daily-life handwriting. This work aims at testing the pen’s sensors and algorithms and the use of the smartpen to detect age-related changes in writing and tremor parameters during daily-life handwriting. A comparison against reference instruments

Water-cooling wall tube leakage accident is an important factor affecting the safe and economic operation of power station boilers. In this article, the acoustic method is applied to locate the leakage from a simulated water-cooling wall tube, and several key technologies are studied in order to identify the precise location of leakage source. Sound wave propagation path in ‘nonuniform temperature

The extensive proliferation of smartphones presents a new opportunity for precise indoor and outdoor location-based services. Although various smartphone-based positioning technologies have been investigated, no practical and economical method has been developed where global positioning system (GPS) cannot be applied. Since it is difficult to estimate travel distance accurately with a low-cost inertial

Since the traditional gear pitting detection technique based on artificial observation has low accuracy and efficiency, an accurate vision detection method based on a new development of Mask R-CNN is explored. In order to solve the issue of small pitting samples, the generated adversarial network is firstly employed to enlarge the training samples with multilevel pitting. Then, we put forward a multipath

Smartphones are affordable devices nowadays, capable of embedding a large variety of sensors such as magnetometers or orientation sensors, but also the hardware needed to connect them to most wireless communication technologies such as Wi-Fi, Bluetooth, or cellular networks. Therefore, they are handy devices able to perform received signal strength indicator (RSSI) measurements for a wide variety of

Rail profile measurement is one of the most critical tasks for track quality inspection to ensure the safe operation of track systems. In modern railway systems, laser triangulation sensors have been widely adopted in onboard measuring units to carry out 2-D rail profile measurement due to their robustness and truly noncontact properties. However, existing solutions limit the degrees of freedom of

In this article, we present a Doppler-effect-compensated ranging system that can be applied to subcentimeter-precision ultrasonic distance measurement for moving targets using a direct sequence spread spectrum (DSSS). First, the theory of the Doppler compensation technique is explained, and then, the evaluation results obtained using maximum-length-sequence coded ultrasonic signals are discussed. In

Accurately detecting man-made intrusion from different events is of great significance for distributed optical fiber sensing perimeter security system. Most traditional algorithms lack the ability to reject various events of unknown class which are mainly from natural disturbance, and greatly decline the accuracy of intrusion recognition in field application. In order to solve this problem, we proposed

This article reports the investigation results of long-term stability tests on on-wafer measurement systems in frequency ranges up to 325 GHz conducted by the NMIJ-AIST. The radio frequency (RF) probe coordinates in the $X$ -, $Y$ -, and $Z$ -directions, and the tilt angle is automatically adjusted by performing RF signal detection. Calibrations and verification processes were repeated for over a year

This article describes the modeling of a resistive voltage divider (RVD) by rational functions using the vector fitting (VF) tool. The method is applied to ratio and phase displacement measurements over a wide frequency range. A Monte Carlo simulation-based sensitivity analysis was carried out to properly estimate the model uncertainty. The modeling tool proved to be an advantageous alternative with

This article proposes a variational Bayesian (VB) inference based on the nonsynchronous array measurement (NAM) (VB-NAM) method in order to obtain the fast and robust localization of low-frequency acoustic sources. To enlarge the aperture size compared with the prototype array, the NAM is performed to measure the acoustic pressures with low-frequency based on the forward power propagation model. The

Electroencephalography (EEG) signals have been proven to be one of the most predictive and reliable indicators for estimating driving fatigue state. However, how to make full use of EEG data for driving fatigue detection remains a challenge. Many existing methods include a time-consuming manual process or tedious parameter tunings for feature extraction, which is inconvenient to train and implement

A distributed phase measurement method of frequency-domain electromagnetic detection is proposed. The theoretical analysis of the previous literature shows that in electromagnetic detection applications, phase as an independent measurement parameter can reduce the diversity of solution, and it also has the advantage of greater steepness than the amplitude. Currently, there are few literature dealing

In most practical applications of fault diagnosis methods, two problems will inevitably arise. First, limited by the monitored object itself and its environment, accelerators are difficult to install. Second, industrial applications lack data with fault labels, which limits the use of data-driven-based methods. To solve these problems, a current signal-based adaptive semisupervised framework (C-ASSF)

In this article, we propose a single-vibration sensor-based method for detecting incipient faults in squirrel cage induction motors (SCIMs). We consider defects in different parts of the bearing (inner raceway, outer raceway, cage train, and rolling element) and in a single bar of the rotor. The vibration signal is dominated by the fundamental rotational frequency and its harmonics. The dominant components

Sample entropy (SpEn) is a measure of the underlying regularity or complexity of a system that is achieved by assessing the entropy of a time series recorded from the system. It is a powerful signal processing tool and has received increasing attention in recent years. SpEn has been successfully applied in biomedical measurements and other applications. In particular, many emerging applications require

The joint kinematics for negotiating different locomotion modes (LMs), mainly level-ground walking (LGW) and ascending and descending staircases, are significantly different. Therefore, an algorithm that could detect gait events during the LGW would not be efficient during the stair ascent (SA) and stair descent (SD) even though the one designed for SA would not be suitable for SD, and vice versa.

Electrical capacitance tomography is a widely used sensor modality for flow imaging in many industrial settings. Adaptive electrical capacitance volume tomography (AECVT) extends the capabilities of traditional ECT by enabling direct volumetric imaging and an improved resolution. Construction of the sensitivity matrix is a necessary step to obtain flow images. This step requires the computation of

Fabric defect detection plays an essential role in the textile production process, which was widely applied in the textile industry. For fabric defect detection, many algorithms have been proposed. However, lots of important problems, such as the accuracy of detection, the computational complexity of the algorithm, and data imbalance, still needed to be addressed for application in industrial production

This article describes an algorithm used to automatically detect differential coil eddy current (EC) defect signal features using a sum of Gaussians approach. Defect signals are decomposed into positive and negative portions then a thresholded binary image is constructed using the Parzen–Rosenblatt window technique. Mathematical morphology operators are then used to denoise the thresholded binary image

In this article, a technique based on artificial neural networks (ANNs) is proposed to extract stable complex permittivity and permeability of low-loss materials from transmission/reflection (T/R) measurements. The equations of attenuation constant $\alpha $ and phase constant $\beta $ of $a$ sample-filled transmission line are derived. The calculated $\alpha $ and $\beta $ are put into an ANN model

This article describes a new traceable measurement system, designed for the characterization of inductive charging stations for electric vehicles. This article particularly focuses on static charging (stationary vehicle), while dynamic charging (charging while driving) requires a significantly different system. The measurement system is able to measure on-site performance and efficiency of the charging

To improve the wear monitoring accuracy of steel tribo-pairs, a ferromagnetic particle sensor that consists of a magnetic loop with two cylindrical magnetic poles and one magnetic housing is proposed. The induction coil is placed inside the magnetic poles to shield against external electromagnetic interference. The air gap is designed to 1 mm between the two magnetic poles, where a rotational symmetric

In this article, the electrochemical monitoring of phenol (Ph) in water by using a nanostructured MnO 2 -modified screen-printed carbon electrode (MnO 2 -SPCE) is reported. MnO 2 nanoparticles were synthesized by the redox-precipitation method. Morphological, textural, and microstructural characteristics were investigated by scanning electron microscopy (SEM), X-ray diffraction, Raman, Brunauer–Emmett–Teller

Compressive sensing (CS) has emerged as a promising technique for collecting and reconstructing digital signals. In this article, we design a CS method for magnetic flux leakage (MFL) detectors based on the problem’s physics. A method is presented to reconstruct $x$ and $y$ components of magnetic $\overrightarrow {B}$ field using a few samples. First, the problem is formulated into an optimization

During the impulse voltage comparison test, it is important to keep the waveforms smooth for obtaining consistent experiment results, especially for the front time parameter. However, steps or oscillations are often found on the front of the waveforms. The authors propose a theory that these oscillations can be caused by the resistors in the damped capacitive voltage divider, which often serves as

Accurate observations of the gravitational acceleration ( $g$ , about 9.8 m/s 2 ) provide important geophysical data for use in geophysics, metrology, and geodesy. At present, the most widely used absolute gravimeter determines the value of $g$ by tracking a falling retroreflector in a vacuum using a laser interferometer. The precision and accuracy of the measurement are mainly affected by ground vibration

This article shows the design of a simple construction two-stage current transformer with ratios from 5 A:5 A to 2000 A:5 A. It can be self-calibrated. Primary windings are separated into sectors to allow series–parallel configurations. Beginning with 5 A:5 A-ratio self-calibration, the higher ranges relate their errors to this first one, considering parasitic effects. Stray capacitances are considered

In this article, we present a simple and low-cost experimental setup for thermoelectric effect measurements of thin film materials near room temperature, which can be used to determine their conductivity types. Bi 2 Te 3 and Sb 2 Te 3 thin films grown by the molecular beam epitaxy technique were used as the tested samples. Their Seebeck coefficients were determined to be $(-141\pm 1)\,{\mathrm{\mu

The advancement of next-generation systems has led to a rapid increase in day-to-day applications by connecting billions of devices. Mobile networks require a considerable cost to support these billions of devices, and conventional IEEE 802.11 is meant for the usage of small-scale applications. To support long-range applications, IEEE task group-ah has proposed a new standard named IEEE 802.11ah. However

Atrial fibrillation (AF) can cause a variety of heart diseases and its detection is insufficient in outside hospital. We proposed three methods for AF diagnosis in ambulatory settings. The first method is a convolutional neural network (CNN) trained on modified frequency slice wavelet transform (MFSWT) data. The second is a support vector machine (SVM) classifier trained on multiple AF features data

This article proposes an automatic high-precision detection method for structure parameters of catenary cantilever devices (SPCCDs) using 3-D point cloud data. The steps of the proposed detection method are: 1) segmenting and recognizing the components of the catenary cantilever devices, 2) extracting the detection plane and backbone component axis of catenary cantilever devices, and 3) detecting the

Gearbox failure is one of top-ranked factors leading to the unavailability of wind turbines (WTs). Existing data-driven studies of gearbox failure detection (GFD) focus on improving detection accuracies while reducing false alarms has not received sufficient discussions. In this article, we propose a deep joint variational autoencoder (JVAE)-based monitoring method using wind farm supervisory control

The key of bearing fault feature extraction is to select the optimal resonant frequency band (ORFB) containing fault information with an appropriate index. However, the background noise and cyclostationary impulsive noise will seriously affect the location of ORFB. Moreover, traditional indexes may be ineffective for compound faults. Thus, a novel fault feature method for rolling bearings is explored

An accurate assessment of the damp status of oil-impregnated paper (OIP) bushings is crucial for the power industry to make informed decisions on the maintenance and replacement schedule of bushings. This article proposes a hybrid of the convolutional neural network (CNN) and the hidden Markov model (HMM) for estimating the damp status (i.e., moisture level and moisture source) of bushings especially

Many applications utilize flexible capacitive electrode implementations and analog front-end optimizations for improving noncontact electrocardiogram (ECG) measurements. However, the influence of the negative impedance in the circuit front end on noncontact measurements has not been investigated. The objective of this study was to develop negative impedance capacitive electrodes for improving the degraded

Complex-valued, multifrequency electrical capacitance tomography (CVMF-ECT) is a recently developed tomographic concept which is capable of simultaneously reconstructing spectral permittivity and conductivity properties of target objects within the region of interest. To date, this concept has been limited to simulation and another key issue restricting its wide adoption lies in its poor image quality

Multimodal medical image fusion (MMIF) technology can effectively improve the efficiency and accuracy of doctors in clinical diagnosis and treatment by combining different modes of medical images into a medical image with rich information. To achieve an optimal balance between computational loss and fusion quality, this article presents a new MMIF method based on weighted local energy matching measurement