Application of the deformation field measurement method to wood during drying

1996 ◽  
Vol 30 (6) ◽  
Author(s):  
Grima Kifetew
Keyword(s):  
Field Measurement ◽  
Measurement Method ◽  
Deformation Field

An Electroscope System Based on Electric Field Measurement Method for UHV Transmission Lines

2009 ◽  
Vol 10 (2) ◽  
Author(s):  
Fan Yang ◽  
Wei He ◽  
Tao Chen ◽  
Xiaochu Luo ◽  
Yongchang Fu
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Transmission Lines ◽  
Field Measurement ◽  
Measurement Method ◽  
Electric Field Measurement ◽  
Set Up ◽  
Global Regularization ◽  
Uhv Transmission Lines ◽  
Internet Network

The paper describes an electric field measurement method based electroscope system to check the electrification state of ultra-high voltage transmission lines, which is composed of three parts: 1) Measuring terminal; 2) Central sever; 3) GPRS and Internet network. The measuring terminal was used to measure the electric field and the location of the measuring points, then the measured data was sent to the central sever by GPRS and Internet network, and requested for an electricity state confirmation.When the sever received a request from a terminal, the electric fields and locations of the measuring points were obtained first, then according to the location of the measuring points, the server searches the corresponding objective transmission lines in the database and read their parameters. According to the parameters of the measuring points and transmission lines, a calculation would be carried out to confirm the electrification state of the transmission lines. For the confirmation calculation, equations for the electric field inverse problem of the transmission lines were set up first, then global regularization and damped Gauss Newton (DGN) method were used to solve the inverse problem.A 500kV double loops transmission line was taken as an example to verify the validity of this method. The electric field and location of 11 measuring points were measured by the measuring terminal firstly, and then sent to the central sever. Electrification state was confirmed by the central sever.

Wheel-Rail Lateral Force Continuous Measurement Based on Rail Web Bending Moment Difference Method

2011 ◽  
Vol 105-107 ◽  
pp. 755-759 ◽  
Author(s):  
Yi Fan Li ◽  
Jian Xin Liu ◽  
Jian Hui Lin
Keyword(s):  
Difference Method ◽  
Field Measurement ◽  
Measurement Method ◽  
Continuous Measurement ◽  
Bending Moment ◽  
Lateral Force

According to the wheel-rail interaction characteristics and the restriction condition of track, a wheel-rail lateral force continuous measurement method is researched. This paper validates the feasibility of rail web bending moment difference methodthough simulation calculationand field measurement. The results shows that this method is absolutely capable of achieve continuous measurement of wheel-rail lateral force.

scholarly journals Automatic Estimation Method for Intersection Saturation Flow Rate Based on Video Detector Data

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Linhong Wang ◽  
Yunhao Wang ◽  
Yiming Bie
Keyword(s):  
Time Series ◽  
Flow Rate ◽  
Field Measurement ◽  
Measurement Method ◽  
Estimation Method ◽  
Ordinary Least Squares ◽  
Automatic Estimation ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
Video Detector

Saturation flow rate (SFR) is a fundamental parameter to the level of service evaluation, lane capacity calculation, and signal timing plan optimization at signalized intersections. It is affected by a variety of factors including weather conditions, lane width, and the type of the driver. How to accurately estimate the SFR remains one of the most important tasks in traffic engineering. Existing studies generally rely on the field measurement method which requires a large number of people collecting data at the intersection. As a result, the method incurs a high economic cost and cannot adapt to the dynamic change of SFR. In recent years, video detectors have been widely installed at intersections which are capable of recording the time each vehicle passes the stop line, the number plate of each vehicle, and the vehicle type. This paper therefore aims to propose an automatic estimation method for the SFR based on video detector data in order to overcome the limitation of the field measurement method. A prerequisite for estimating the SFR is to recognize the saturation headway. We consider the actual vehicle headway as time series and build an auxiliary regression equation whose parameters are estimated through the ordinary least squares method. We employ the Dickey-Fuller test to verify whether the headways in the time series are saturation headways. An iterative method using quantiles is proposed to filter out abnormal data. The SFR is finally calculated using the average value of saturation headways. To demonstrate the proposed method, we conduct a case study using data from an intersection with three entrance lanes in Qujing city, Yunnan Province, China. The overall estimation process is displayed and the impacts of quantile selection and data duration on the estimation accuracy are analyzed.

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