This paper deals with the identification of terrain that is crucial to trigger the damping in semi-active lower limb prosthesis. Objective: To identify level ground and ramp terrains using foot-to-ground angle (FGA) measurement. Methods: First, Instrumented shoe for FGA measurement was developed. Next, data collection from able-bodied (n=5) and amputee (n=1) participants was carried out. Finally, a

To overcome the large error caused by traditional ETC non-destructive detection, a novel method based on directly analysing the normalized capacitance value was proposed by using the finite element method described in the present study. In this article, the correlation between the normalized capacitance value and the measured object (the defect) size was summarized, and the influence of the geometric

Soil water content measurement is indispensable to precision agriculture. A novel soil water content measuring method based on frequency scanning is proposed in this research. The measuring system consists of a monopole antenna to emit and receive electromagnetic waves as well as a network analyzer. The soil equivalent circuit model is presented and its spectroscopy is obtained by comparing incident

Despite having a small footprint origin, COVID-19 has expanded its clutches to being a global pandemic with severe consequences threatening the survival of the human species. Despite international communities closing their corridors to reduce the exponential spread of the coronavirus. The need to study the patterns of transmission and spread gains utmost importance at the grass-root level of the social

A sign language recognition (SLR) system has been broadly used by deaf individuals as a communicative tool. Progress of SLR systems paves the way for the development of Human–computer interaction (HCI) since sign language is the most structured form, and every movement has a specific meaning. In this paper, a wearable low-cost device based on surface electromyography (sEMG) and Inertial Measurement

Miniature fixed-point blackbodies (MFPBs) can realize the on-orbit multipoint temperature calibration through the known characteristic temperature. This ability is important for improving the precision and life span of earth observation systems. For acquisition of characteristic temperature, numerical simulation has lower cost and test condition requirements. However, ordinary numerical models can’t

Image-based optical methods have been widely used for noncontact structural displacement measurements, due to their prominent advantages over conventional contact sensors. However, existing optical methods usually require complicated and expensive imaging systems, and have difficulties to accurately measure in-plane displacements when the optical axis is not perpendicular to surface of the object (i

In this study, we present a novel method that can measure the similarity of two digital radiography (DR) images from pressure pipeline welds. Firstly, in order to obtain a uniform weld image, a new tilt angle detection algorithm is proposed based on the fitting line of edge midpoint, which can quickly and accurately detect the tilt angle of a pipeline in a weld image. Secondly, a new algorithm based

This study proposes a new real-time sign recognition system based on a wearable sensory glove, which has 17 sensors with 65 channels. We introduce the DataGlove to recognize various, possibly complex hand gestures of the Malaysian Sign Language (MSL). With 65 data channels, DataGlove can satisfy the requirement suggested by the analysis of hand anatomy, kinematic and gestures. Four groups of sensors

This paper presents original work concerning modified measurement method, related processing technique and output values forming. The method introduces extended length between pressure measurement points in pipes filled with open cell metal foam. It is proven theoretically and practically that increased distance between pressure sensors assures self-affinity of differential pressure signal. The modified

Real-time precise orbit/clock product is fundamental to BeiDou Navigation Satellite System (BDS) real-time precise point positioning (PPP). In order to explore achievable performance of BDS real-time orbit/clock products and thus offer usage recommendations for BDS real-time PPP users, this paper studies BDS real-time orbit/clock corrections provided by four International GNSS Service (IGS) Analysis

A framework for energy meters’ error remote monitoring to assist metrological supervision in legal and industrial metrology fields is suggested. As a use case, a method for the remote monitoring of customer’s meter error using a certified reference sum meter is discussed. The method is aimed at remotely determining an adjustment gain (multiplicative error correction factor) of a meter. An analysis

Longitudinal differential protection is among the most important protection mechanisms in the short transmission lines. During energization, some factors might disrupt the performance, and on-line fault detection using the longitudinal differential relay might result in an undesired interruption. Therefore, in this paper, a new method is proposed to detect the fault current from the switching currents

The measurement performed by edge devices is advantageous in remote pipeline monitoring and maintenance in the Internet of Things (IoT) network. It provides a non-invasive, easy-to-install and compatible solution for upgrading existing pipelines. However, there is no systematic testing scheme for different pipelines. This article presents comprehensive theories and simulation results for indirect temperature

The optically stimulated luminescence (OSL) of quartz is widely used in luminescence dating and retrospective dosimetry. The signal exploited up to now in measurement protocol is complex. It is hard to check by standard measurements whether the fast component which is the most appropriate for the age estimation dominates in the total OSL signal. Recently, a new method called thermally modulated OSL

One of the most precise standards of AC voltage in the frequency range from 1 MHz to 100 MHz is the Calorimetric Thermal Voltage Converter (CTVC) designed at National Research Council (NRC) in Ottawa, Canada. Unfortunately, this converter has a few times higher value of DC reversal error than other known thermal voltage converters (TVC). This article presents analysis of possible reasons of such a

Compared with the artificial crack detection method, the bridge crack recognition method based on computer vision has the advantages of high efficiency, easy operation and low cost. However, under the condition of moving (UAV) shooting, the crack images collected often have quality defects such as low definition, complex background, severe interference by light and noise. especially when faced with

Fiber-optic sensors have developed rapidly because of their excellent sensing performances and abilities to detect in remote and harsh environments. However, on some special occasions with high requirements for sensitivity and resolution, the traditional optical fiber sensing mechanism is difficult to meet the detection requirements. Therefore, it is very necessary to explore new sensor sensitization

Many researchers attempted to quantify dispersion states of microstructures. Several algorithms to analyze micrographs are proposed to evaluate indicators reflecting the dispersion states. However, the values of these indicators can correlate several performances of a given system, to some degree. This paper proposes a new indicator, the degree of dispersion (DoD), that assesses the dispersion state

The paper puts forward a novel method of the damage detection using singular value decomposition (SVD) and artificial bee colony (ABC) algorithm for beam structures. The proposed method includes two steps: damage localization and depth estimation. In the first step, singular value decomposition is used to decompose the trajectory matrix of the attractor reconstructed from the shape data to localize

A novel functional-type high integration polarization interference fiber temperature sensor based on 45 degree tilted fiber Bragg grating in-fiber polarizer (TFBG-PIF-TS) is proposed. The accuracy, resolution, stability, linearity and sensitivity of the prototype are tested and compared with PT100, 18B20 as well as polarizing plate based polarization interferometric fiber temperature sensor (PP-PIF-TS)

The influence of powder-chip based reinforced LM6 aluminum alloy fabricated by a consolidated effect of stirring and squeeze process in the semi-solid stage is reported for wear properties. Effect of oxide formation on the worn surfaces due to the processing was noticed and experimental results showing that powder-chip based reinforcement with semi-solid slurry affects and gave excellent resistance

A recent appendix in the aircraft regulations comprises testing supercooled large droplets impinging on its surfaces. For those tests, the size and distributions of droplets need to be characterized in icing wind tunnels. In this paper, the applicability of implementation of the “Interferometric Laser Imaging for Droplet Sizing” technique inside a wind tunnel with a 3 m x 2 m open elliptical test section

In this investigation, a fan-beam photon attenuation based system, including one X-ray tube and two sodium iodide crystal detectors, combined with group method of data handling (GMDH) neural network is proposed to recognize type of flow regime and predict gas-oil-water volume fractions of a three phase flow. One GMDH neural network was considered for recognizing flow patterns and two GMDH networks

High process complexity becomes an important issue due to the increased number of product variants demanded by customers. The coordinate measurement is one of the key technologies used in the dimensional control to inspect and improve the accuracy of produced components. Dimensional inspection is often carried out on conventional coordinate measuring machine (CMM). However, there are concerns about

International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 80000, the International System of Quantities, collects and organizes the most important physical quantities into a coherent system of quantities whose foundation for measurements is the International System of Units (SI). This short communication outlines a report that, in a similar fashion, collects

In this article a repetitive group sampling control has been introduced for the neutrosophic statistics under the Conway-Maxwell-Poisson (COM-Poisson) distribution. The suggested chart has been compared with the existing plan using simulated data generated from neutrosophic COM-Poisson distribution. The practical implementation of the suggested chart has also been expounded using the data from the

In this work, genetic algorithm (GA), kernel based mutual information (KEMI) fitness function and variational mode decomposition (VMD) based strategy is proposed for the purpose of easy identification of single and multiple defects of bearing, both at fixed and varying speed. To make the multiple defects identification possible at varying speed, Fourier synchro squeezed transform (FSST) based processing

Simultaneous Localization and Mapping (SLAM) is the basis for intelligent mobile robots to work in unknown environments. However, traditional feature extraction algorithms that traditional visual SLAM systems rely on have difficulty dealing with texture-less regions and other complex scenes, which limits the development of visual SLAM. The studies of feature points extraction adopting deep learning

This comment shows that the results and analysis related to the XDK110 temperature sensor presented in the ”Implementation of a reliability test protocol for a multimeasurement sensor dedicated to industrial applications of the Internet of things” do not hold as asserted by the authors. The reason analysis is discussed in detail.

Metrology remains a uniquely important endeavour. A sign of its success and robustness as an infra-technology is that it usually goes unnoticed. This means that it is in danger of being under-valued and under-appreciated. The sure-footing that metrology provides to the quality infrastructure will be especially important as the world grapples with the aftereffects of the COVID-19 pandemic, rebuilding

In this paper, relevant twenty features were extracted from the dynamic resistance signal of the welding operation and subsequent mathematical models incorporating the qualifying features were developed to investigate the relationship among dynamic resistance, welding quality and welding parameters based on the stepwise regression method. The results of the analysis of variance indicated the peak point

The temperature cycling test is always carried out in thermal calibration scheme of the inertial navigation systems, in which the temperature-stabilization chamber is quite needed. The temperature cycling test can provide full temperature parameters of the accelerometer and gyro triads, but it also requires complex operation procedures and expensive test instruments. A fast estimation method using

This paper presents design optimization, numerical modelling, fabrication and characterization of a single-axis comb drive MEMS gap-changeable differential capacitive accelerometer with a compact footprint of 2 mm × 2 mm. High sensitivity is achieved by optimizing the ratio of the anti-finger gap to finger gap spacing. It is found that a gap ratio of 3.44 leads to a displacement sensitivity of 0.0139 µm/g

This paper presents an integrated approach for the detection and classification of the faults of rolling bearing in rotary machines. Permutation entropy (PE) is integrated with a flexible analytical wavelet transform (FAWT). The signals from healthy and faulty bearing systems with different operating conditions are decomposed by FAWT. To compare effectiveness of the proposed methodology, dyadic discrete

A segmentation singular value decomposition (SVD)-lifting wavelet transform (LWT) denoising algorithm based on ensemble empirical mode decomposition (EEMD) was proposed to better suppress noise in an atmospheric lidar return signal. The EEMD method is used to distinguish inherent modal functions (IMFs) of the noise and signal, and remove the IMF with noise as its main component. Moreover, the SVD-LWT

This paper designs a gear rotational speed sensor consisting of a permanent magnet and a FeCoSiB/Pb(Zr,Ti)O3 magnetoelectric composite as a magnetic sensor. The influences of distances between the detection gear, FeCoSiB/Pb(Zr,Ti)O3 composite, and the permanent magnet on output voltage are investigated in detail. In order to achieve a larger output voltage, the FeCoSiB/Pb(Zr,Ti)O3 composite should

An accurate model of rolling lobe air spring (RLAS) is the key to achieve the design, matching and optimization of air suspension. A refined stiffness model of RLAS with structural parameters and the stiffness characteristics of rubber bellows is developed in this paper. Prediction models of structural parameters, including effective area and its change rate, effective volume and its change rate, are

With the development of economy, a large number of human development activities in the natural environment have directly or indirectly increased the possibility of geological disasters. Every year a large number of geological disasters pose a serious threat to the safety of human life and property, and the effective management of geological disasters has become one of the major difficulties facing

Improvement of weak base soils under low-rise buildings, storage tanks, bridge piers, and also the treatment of soft foundations of factories and embankments can be achieved by using stone columns. This technique represents an economical method for the improvement of soft and compressible soils. Moreover, because of their environmental compatibility, low cost, and ease of implementation, they have

The recent progress in the area of signal processing has led to the development of intelligent schemes for fault classification and faulty phase selection in distribution system. The conventional algorithms find limitations to detect high impedance fault (HIF) and HIF remains a great concern for utilities as it can cause serious danger and accident if not detected properly. This study presents an algorithm

Local damage detection in bearings focuses on the identification of periodically impulsive components. Popular methods assume presence of either non-Gaussian noise or different frequency band for informative and non-informative impulses, and use statistics to select appropriate band. Here two impulsive sources occupy the same frequency range: a fault-related signal of interest, and non-cyclic noise

For gear fault diagnosis, it is often encountered that the input samples are naturally constructed as two-dimensional feature matrices with rich structure information. Support matrix machine (SMM) is an effective classifier for these matrix data, which fully leverages the matrix structure information. However, it is indispensable for SMM to artificially extract fault features and select the useful

Realtime quality inspection of resistance spot welding (RSW) is a promising way to actualize intelligent manufacturing of automotive body structures. Apart from nugget diameter, weld penetration is also an important quality index for weld quality assessment. To that point, a novel approach to nondestructive measurement of weld penetration for the robotic RSW process is presented. In-depth research

The slope calculation of phase measuring deflectometry is essentially a problem finding correspondence between camera, screen and reflecting point, while the reflecting point suffers from an ambiguity problem. This problem can be solved using an iterative reconstruction strategy, however, the existence of systematic error in the iteration circle significantly harm the accuracy performance. A linear

With the rapid development of technologies such as communications, embedded computing, and sensors, wireless sensor network technology has become more mature and its applications have become more and more extensive. The development of technology has brought great convenience to people's lives and work. At the same time, people's activity and exercise are greatly reduced, causing health problems such

High-rate GNSS observations are usually studied in relation to earthquake analysis and structural monitoring. Most of the previous research on short-term dynamic deformations has been limited to natural earthquakes with magnitudes exceeding 5 and amplitudes equal to several dozen centimetres. High-frequency position monitoring via GNSS stations is particularly important in mining areas due to the need

With the development of the wind energy industry, condition monitoring (CM) has become one of the important ways to improve the reliability of wind turbines (WTs). A data driven WTCM method based on a novel multivariate state estimation technique (MSET) is proposed, which can realize the fault early warning of WT components. In order to reduce the information redundancy of operational parameters, the

The integrated navigation system consists of Inertial Navigation System (INS) and receiver of Global Navigation Satellite System (GNSS). The combined system provides continuous and accurate navigation solution when compared to standalone INS or GNSS. However, the accuracy of navigation solution of the integrated system degrades during GNSS outages. Aiming to improve the position and velocity precision

The surface quality safety inspection of a light-emitting diodes (LED) chip is an indispensable step in the LED production process. The traditional vision inspection algorithm extracts defect features by artificial feature extraction. This method has become increasingly difficult as chips have become more miniaturized, and it is difficult to meet the quality safety requirements. Recently, machine learning-based

Determination of time-of-flight (TOF) is crucially important in liquid ultrasonic flow meters. There are some deficiencies of previous TOF detection methods in practical applications. Inspired by our last work and the knowledge of clustering algorithms, we proposed a TOF determination method based on ultrasonic signal onset (USO) detection and multiple-zero-crossing technique to solve cycle-skip problem

As the development of the global navigation satellite system (GNSS), the navigation satellite transmitting multi-frequency signals becomes a prevailing trend. Currently, the usual GNSS precise orbit determination (POD) strategy uses dual-frequency (DF) ionosphere-free (IF) linear combination to build up the observation equation. In the area of precise positioning, it has been validated that the third

Pumped storage unit (PSU) operated under the combination of different condition, which may cause equipment wear, fatigue and fault issues. It is difficult to achieve accurate and stable degradation trend prediction (DTP) considering only either the accuracy or stability. In this paper, a combined multi-objective optimization model is proposed for DTP of PSU. Firstly, the health model of PSU is constructed