A Practical Engineering Approach to Interpreting Measurement Data in Uncertain Contexts

2017 ◽  
Author(s):  
Ian F. C. Smith ◽  
Sai G. S. Pai
Keyword(s):  
Measurement Data ◽  
Engineering Approach ◽  
Practical Engineering

A Possibility Estimation Model and its Application

2013 ◽  
Vol 475-476 ◽  
pp. 423-427
Author(s):  
Lin Na Ji ◽  
Feng Bao Yang ◽  
Xiao Xia Wang
Keyword(s):  
Measurement Data ◽  
Engineering Application ◽  
Transformation Method ◽  
Estimation Model ◽  
Property Estimation ◽  
New Methods ◽  
Proposed Model ◽  
Practical Engineering ◽  
New Ideas ◽  
Possibility Distributions

Aiming at some uncertainty problems such as quality inspection of adhesive structure and risk assessment in the practical engineering application, a possibility estimation model is established. Firstly, according to the fuzziness, randomness and uncertainty of the measurement data, a transformation method of possibility distribution with non-single peak values and nonlinearity is proposed from probability density function. Secondly, for possibility distributions of measurement data of each sensor, a kind of possibility fusion rules is put forward, then the fusion distribution is estimated by the possibility mean. Finally the model is applied to the mechanical property estimation of adhesive structure, and the result forecasts the quality. The proposed model with strong applicability, not only provides convenience for the operations among possibility distributions, but also offers new ideas and new methods to deal with uncertain problems.

scholarly journals Method for Estimating Harmonic Parameters Based on Measurement Data without Phase Angle

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 879 ◽  
Author(s):  
Fulin Zhou ◽  
Feifan Liu ◽  
Ruixuan Yang ◽  
Huanrui Liu
Keyword(s):  
Power Quality ◽  
Phase Difference ◽  
Measurement Data ◽  
Power Grids ◽  
Least Squares Regression ◽  
Phase Information ◽  
Point Of Common Coupling ◽  
Practical Engineering ◽  
General Power ◽  
Harmonic Voltage

The excessive use of power electronics makes power quality problems in power grids increasingly prominent. The estimation of the harmonic parameters of harmonic sources in the power grid and the division of harmonic responsibilities are of great significance for the evaluation of power quality. At present, methods for estimating harmonic parameters and harmonic responsibilities need to provide the amplitude and phase information of the current and voltage of the point of common coupling (PCC). However, in practical engineering applications, the general power quality monitor only provides the amplitude information of the voltage and current of the measured point and the phase difference information between them. Missing phase information invalidates existing methods. Based on the partial least squares regression method, the present work proposes a method for estimating harmonic parameters in the case of monitoring data without phase. This method only needs to measure the amplitude information of the harmonic voltage and current of the PCC and the phase difference between them, then use the measurable data to estimate the harmonic parameters and the harmonic responsibility of each harmonic source. It provides a new way to effectively solve the problem that the measured data of the project has no phase information. The feasibility and effectiveness of the proposed method are proved by simulation data and measured engineering data.

Research on the Underground Pressure Behavior Law of Repeated Mining Working Face under the Gob of Small Colliery

2014 ◽  
Vol 522-524 ◽  
pp. 1434-1440
Author(s):  
Chun Xiang Hu ◽  
Jin Kai Liu ◽  
Qi Li ◽  
Yong Zhang
Keyword(s):  
Lower Layer ◽  
Measurement Data ◽  
Simulation Software ◽  
Efficient Production ◽  
Distribution Law ◽  
Pressure Behavior ◽  
Safe Production ◽  
Working Face ◽  
Practical Engineering ◽  
Residual Coal

The gob of small colliery has been one of the main factors threatening the safe production of coal mine. The repeated mining working face in a certain mine is the practical engineering background in this paper to study the influence of gob in small colliery on the mining of lower layer. By using the numerical simulation software FLAC3D, the stress distribution law and the change of displacement during lower layer mining were analysed. It can be concluded from the analysis of field measurement data that: there is stress relief under the gob of small colliery because the distribution of coal is irregular resulting from the random distribution of gobs in small colliery, while the residual coal causes the effect of stress concentration on the lower layer mining; relatively large displacement appears in the caving zone of the upper layer by the roof of working face and the support should be strengthened appropriately during mining; meanwhile, the gob of small colliery can cause the nonuniform distance of periodic weighting in the roof, and segmented pressure behavior can be observed during the periodic weighting of the working face. Research results could provide some guidance to the safe and efficient production in repeated mining working face in the mining with similar conditions.

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