Search results for "Measurement"
showing 10 items of 2918 documents
Diagnosis of mechanical unbalance for double cage induction motor load in time-varying conditions based on motor vibration signature analysis
2013
This paper investigates the detectability of mechanical unbalance in double cage induction motor load using motor vibration signature analysis technique. Rotor imbalances induce specific harmonic components in electrical, electromagnetical, and mechanical quantities. Harmonic components characteristic of this category of rotor faults, issued from vibration signals analysis, are closely related to rotating speed of the rotor, which complicates its detection under non-stationary operating conditions of the motor. Firstly, experimental results were performed first under healthy and mechanical load unbalance cases, for different load levels under steady-state operating conditions to evaluate th…
Pattern recognition in cyclic and discrete skills performance from inertial measurement units
2014
The aim of this study is to compare and validate an Inertial Measurement Unit (IMU) relative to an optic system, and to propose methods for pattern recognition to capture behavioural dynamics during sport performance. IMU validation was conducted by comparing the motions of the two arms of a compass, which was equipped with IMUs and reflective landmarks detected by a multi-camera system. Spearman’s rank correlation tests showed good correlations between the IMU and multi-camera system, especially when the angles were normalized. Bland-Altman plot, root mean square and the normalized pairwise variability index showed low differences between the two systems, confirming the good accuracy level…
A Technique for Power Supply Harmonic Impedance Estimation Using a Controlled Voltage Disturbance
2002
A method for power system impedance estimation is presented. The method employs a power converter to inject a voltage transient onto the supply system. As the technique employs controlled power electronic devices it may be used as a stand alone piece of a portable measurement equipment, or it may be embedded into the functions of an active shunt filter for improved harmonic control. The impedance is estimated through correlation of the measured voltage and current transients. Simulations and experimental results demonstrate the measurement technique is highly accurate and effective.
Development of a Coupling System for Medium Voltage Power Line Communication in the CENELEC A Frequency Band
2016
In this paper the performances of a new power line communication (PLC) coupling system for medium voltage (MV) smart grids are investigated in the CENELEC A frequency band (i.e. 3 - 95 kHz). The new coupling solution is based on the use of the capacitive divider of the voltage detecting system (VDS) as PLC coupler to the MV network. According to IEC 61243-5, VDS are worldwide used to reveal the presence of the mains voltage to ensure the safety of the operators. A proper interface circuit has been invented and patented to couple the PLC signal through the VDS. In this way no dedicated MV PLC coupler is required, thus avoiding the related costs of the coupler, of its installation, and those …
Novel Resistance Measurement Method: Analysis of Accuracy and Thermal Dependence with Applications in Fiber Materials
2016
Material resistance is important since different physicochemical properties can be extracted from it. This work describes a novel resistance measurement method valid for a wide range of resistance values up to 100 GΩ at a low powered, small sized, digitally controlled and wireless communicated device. The analog and digital circuits of the design are described, analysing the main error sources affecting the accuracy. Accuracy and extended uncertainty are obtained for a pattern decade box, showing a maximum of 1 % accuracy for temperatures below 30 ∘ C in the range from 1 MΩ to 100 GΩ. Thermal analysis showed stability up to 50 ∘ C for values below 10 GΩ and systematic deviations for higher …
Universal N-partite d-level pure-state entanglement witness based on realistic measurement settings
2018
Entanglement witnesses are operators that are crucial for confirming the generation of specific quantum systems, such as multipartite and high-dimensional states. For this reason, many witnesses have been theoretically derived which commonly focus on establishing tight bounds and exhibit mathematical compactness as well as symmetry properties similar to that of the quantum state. However, for increasingly complex quantum systems, established witnesses have lacked experimental achievability, as it has become progressively more challenging to design the corresponding experiments. Here, we present a universal approach to derive entanglement witnesses that are capable of detecting the presence …
Push-and-Pull Enteroscopy using the Double-Balloon Technique: Method of Assessing Depth of Insertion and Training of the Enteroscopy Technique using …
2005
Background and study aims This study was conducted to test a method of measuring the depth of insertion into the small bowel during push-and-pull enteroscopy using the Erlangen Endo-Trainer. Furthermore, the Erlangen Endo-Trainer model for training in the new method of push-and-pull enteroscopy using the double-balloon technique was also evaluated. Materials and methods Specially prepared packages of porcine upper visceral organs were used, including the esophagus, stomach, duodenum, and small bowel, implanted into the Erlangen Endo-Trainer. In the first step of this study, all of the modifications needed to obtain a model useful for training in the new enteroscopy technique were tested, in…
The Berkeley Innovation Index: A Quantitative Approach to Measure, Track and Forecast Innovation Capability Within Individuals and Organizations
2018
Innovation and entrepreneurship are essential processes for human development, market growth, and technological breakthroughs, and it is vital for economic growth. Despite its importance, innovation is inherently difficult to measure and hence it is almost impossible for an individual or organization to know how they can improve their innovation output or claim that they are great at innovation. This paper presents a novel approach to measure and quantify innovation, called the Berkeley Innovation Index (BII). The BII characterizes and measures innovation capability of an individual or an organization. It builds on the hypothesis that innovation performance depends on the people, culture, a…
The toxicity and concentrations of PAHs in creosote-contaminated lake sediment
1999
Sediment samplers, divided into three layers (0 – 10, 10 – 20 and 20 – 30 cm), were collected from 16 sites in Lake Jamsanvesi, Central Finland. The acute toxicity of pore waters and elutriates (sediment + water 1:4 v/v) were studied by bioluminescence inhibition test and by immobilisation of water fleas (Daphnia magna Straus). Concentrations of polycyclic aromatic hydrocarbons (PAHs) in sediments and elutriates were measured by gas chromatography using flame ionization detection (GC/FID). The highest total PAH concentration was 3.3 mg/g dry weight in the sediment and up to 1.7 mg/l in the elutriate of the uppermost (0 – 10 cm) layer, also being the most toxic to photoluminencent bacteria, …
Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements
2019
Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,…