Analysis on the Return Period of “7.26” Rainstorm and Flood in 2017 in the Wudinghe Basin

The return period of "7.26" rainstorm flood in 2017 in Wudinghe basin is analyzed by the method of P-III distribution. The Lijiahe and Dingjiagou stations with long rainfall observation data in the rainstorm area are selected, and the frequency curve of the annual maximum 24 hours rainfall are established, and the recurrence period of rainfall stations in rainstorm area are estimated according to the parameters determined by the curve fitting method. The frequency curve of the annual maximum peak discharge of Baijiachuan hydrological stations and so on are established, and the return period are analyzed in combination with the historical survey floods. The results show that the return period of Zhaojiabian of heavy rainfall center is about 100 years, and which of the other stations over than 200mm in Wudinghe basin is about 30~90 years; while the return period of the peak discharge of Baijiachuan and Suide hydrological station is about 30 and 20 years respectively.

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3-Order Polynomial Phase Signal Parameter Estimation Algorithm Based on Instantaneous Frequency Curve Fitting Method

2010 International Conference on Electrical and Control Engineering ◽

10.1109/icece.2010.10 ◽

2010 ◽

Author(s):

Yingxiang Li ◽

Weiwen Tang ◽

Yujun Kuang

Keyword(s):

Parameter Estimation ◽

Estimation Algorithm ◽

Frequency Curve ◽

Signal Parameter ◽

Polynomial Phase ◽

Fitting Method ◽

Order Polynomial ◽

Parameter Estimation Algorithm ◽

Phase Signal ◽

Curve Fitting Method

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Water Environmental Capacity Based on the Month-by-Month Frequency Curve-Fitting Method

World Environmental and Water Resources Congress 2016 ◽

10.1061/9780784479858.055 ◽

2016 ◽

Author(s):

F. Dong ◽

X. B. Liu ◽

W. Q. Peng ◽

J. Y. Zhao ◽

S. K. Singh

Keyword(s):

Curve Fitting ◽

Environmental Capacity ◽

Frequency Curve ◽

Fitting Method ◽

Water Environmental Capacity ◽

Curve Fitting Method

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Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System Performance

Metrology and Measurement Systems ◽

10.2478/v10178-012-0033-8 ◽

2012 ◽

Vol 19 (2) ◽

pp. 381-394

Author(s):

José Pereira ◽

Octavian Postolache ◽

Pedro Girão

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Measurement System ◽

Curve Fitting ◽

System Performance ◽

Redox Potentials ◽

Voltage Sweep ◽

Gaussian Curve ◽

Fitting Method ◽

Curve Fitting Method

Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System PerformanceThis paper presents a voltammetric segmented voltage sweep mode that can be used to identify and measure heavy metals' concentrations. The proposed sweep mode covers a set of voltage ranges that are centered around the redox potentials of the metals that are under analysis. The heavy metal measurement system can take advantage of the historical database of measurements to identify the metals with higher concentrations in a given geographical area, and perform a segmented sweep around predefined voltage ranges or, alternatively, the system can perform a fast linear voltage sweep to identify the voltammetric current peaks and then perform a segmented voltage sweep around the set of voltages that are associated with the voltammetric current peaks. The paper also includes the presentation of two auto-calibration modes that can be used to improve system's reliability and proposes the usage of a Gaussian curve fitting of voltammetric data to identify heavy metals and to evaluate their concentrations. Several simulation and experimental results, that validate the theoretical expectations, are also presented in the paper.

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A Useful Curve Fitting Method for Concrete Uniaxial Compressive Experiment Data

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.1015 ◽

2011 ◽

Vol 291-294 ◽

pp. 1015-1020 ◽

Cited By ~ 1

Author(s):

Chong Jin ◽

Hong Wang ◽

Xiao Zhou Xia

Keyword(s):

Experimental Data ◽

Orthogonal Polynomial ◽

Least Square ◽

Base Function ◽

Concrete Material ◽

Fitting Method ◽

Orthogonal Base ◽

The Matrix ◽

Uniform Function ◽

Curve Fitting Method

Based on the superiority avoiding the matrix equation to be morbid for those fitting functions constructed by orthogonal base, the Legendre orthogonal polynomial is adopted to fit the experimental data of concrete uniaxial compression stress-strain curves under the frame of least-square. With the help of FORTRAN programming, 3 series of experimental data is fitted. And the fitting effect is very satisfactory when the item number of orthogonal base is not less than 5. What’s more, compared with those piecewise fitting functions, the Legendre orthogonal polynomial fitting function obtained can be introduced into the nonlinear harden-soften character of concrete constitute law more convenient because of its uniform function form and continuous derived feature. And the fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material.

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