scholarly journals Stage Division of Landslide Deformation and Prediction of Critical Sliding Based on Inverse Logistic Function

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1091
Author(s):  
Liulei Bao ◽  
Guangcheng Zhang ◽  
Xinli Hu ◽  
Shuangshuang Wu ◽  
Xiangdong Liu
Keyword(s):  
Direct Method ◽  
Logistic Function ◽  
New Method ◽  
Threshold Function ◽  
Critical Threshold ◽  
Time Curve ◽  
Acceleration Rate ◽  
Deformation Stages ◽  
Distance Weighting ◽  
Landslide Deformation

The cumulative displacement-time curve is the most common and direct method used to predict the deformation trends of landslides and divide the deformation stages. A new method based on the inverse logistic function considering inverse distance weighting (IDW) is proposed to predict the displacement of landslides, and the quantitative standards of dividing the deformation stages and determining the critical sliding time are put forward. The proposed method is applied in some landslide cases according to the displacement monitoring data and shows that the new method is effective. Moreover, long-term displacement predictions are applied in two landslides. Finally, summarized with the application in other landslide cases, the value of displacement acceleration, 0.9 mm/day2, is suggested as the first early warning standard of sliding, and the fitting function of the acceleration rate with the volume or length of landslide can be considered the secondary critical threshold function of landslide failure.

scholarly journals A Modified Inverse Distance Weighting Method for Interpolation in Open Public Places Based on Wi-Fi Probe Data

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Da-wei Wang ◽  
Lu-ning Li ◽  
Cheng Hu ◽  
Qiang Li ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Path Selection ◽  
Inverse Distance Weighting ◽  
Location Based Services ◽  
New Method ◽  
Absolute Deviation ◽  
Public Places ◽  
Main Challenge ◽  
Distance Weighting ◽  
Selection Behavior ◽  
Inverse Distance

Urban open places with a public service function (e.g., urban parks) are likely to be populated in peak hours and during public events. To mitigate the risk of overcrowding and even events of stampedes, it is of considerable significance to realize a real-time full coverage estimate of the population density. The main challenge has been the limited deployment of crowd surveillance detectors in open public spaces, leading to incomplete data coverage and thus impacting the quality and reliability of the density estimation. To remedy this issue, this paper proposes a modified inverse distance weighting (IDW) method, named the inverse distance weighting based on path selection behavior (IDWPSB) method. The proposed IDWPSB method adjusts the distance decay effect according to visitors’ path selection behavior, which better characterizes the human dynamics in open spaces. By implementing the model in a real-world road network in the Shichahai scenic area in Beijing, China, the study shows a decrease in the absolute deviation by 17.62% comparing the results between the new method and the traditional IDW method, justifying the effectiveness of the new method for spatial interpolation in open public places. By considering the behavioral factor, the proposed IDWPSB method can provide insights into public safety management with the increasing availability of data derived from location-based services.

A New Method for Static Voltage Stability Assessment based on The Local Loadability Boundary

2012 ◽  
Vol 13 (4) ◽  
Author(s):  
Thang Van Nguyen ◽  
Y. Minh Nguyen ◽  
Yong Tae Yoon
Keyword(s):  
Power System ◽  
Voltage Stability ◽  
Direct Method ◽  
Electric Power System ◽  
New Method ◽  
Stability Assessment ◽  
Saddle Node Bifurcation ◽  
Static Voltage Stability ◽  
Saddle Node ◽  
Thevenin Equivalent

Abstract This paper proposes a new method for assessing static voltage stability based on the local loadability boundary or P- Q curve in two dimensional power parameter space. The proposed method includes three main steps. The first step is to determine the critical buses and the second step is building the local loadability boundary or the saddle node bifurcation set for those critical buses. The final step is assessing the static voltage stability through the distance from current operating point to the boundary. The critical buses are defined through the right eigenvector by direct method. The boundary obtained by the proposed method that is combining a variation of standard direct method and Thevenin equivalent model of electric power system is a quadratic curve. And finally the distance is computed through the Euclid norm of normal vector of the boundary at the closest saddle node bifurcation point. The advantage of the proposed method is that it keeps the advantages of both efficient methods, the accuracy of the direct method and simple of Thevenin Equivalent based method. Thus, the proposed method holds some promise in terms of performing the real time voltage stability assessment of power system. Test results of New England 39 bus system are presented to show the effectiveness of the proposed method.

A New Method Based on Lyapunov Exponent to Determine the Threshold of Chaotic Systems

2014 ◽  
Vol 511-512 ◽  
pp. 329-333
Author(s):  
Yang Liu ◽  
Xin Chun Zhang
Keyword(s):  
Lyapunov Exponent ◽  
Chaotic Systems ◽  
Sampling Period ◽  
Qr Decomposition ◽  
Sampling Time ◽  
Duffing Equation ◽  
Experimental Results ◽  
New Method ◽  
Critical Threshold ◽  
Periodic Signals

The Duffing equation has been widely used to detect weak periodic signals. The transition threshold is the key to detect. Unfortunately, there is no effective method to determine the critical threshold. To solve this problem, a new method based on the QR decomposition to calculate Lyapunov exponent is presented. The accuracy of the algorithm will gradually improve with the sampling time increasing or the sampling period decreasing. The experimental results show that the method can determine the interval which contains the threshold, and detect the mutation acts of chaotic systems.

A Direct Method for Analyzing Accelerations in Complex Mechanisms

1972 ◽  
Vol 39 (1) ◽  
pp. 266-271
Author(s):  
C. H. Chiang
Keyword(s):  
Direct Method ◽  
New Method ◽  
Complex Mechanism ◽  
Diagram Method ◽  
Acceleration Analysis ◽  
Complex Mechanisms ◽  
A Direct Method

Complex mechanism containing four-bar loops may be treated as simpler compound mechanisms in acceleration analysis by introducing the relative center of curvature of the relative path of a certain point on one link with respect to the opposite link. By means of a new method of acceleration analysis recently suggested by the author, together with the relative center of curvature, it is possible to analyze accelerations of complex mechanisms in a simple and direct way. Results thus obtained are obviously more accurate than those found by using the conventional acceleration diagram method.

A new method for the rapid determination of volatile substances: the SPME-direct method

2001 ◽  
Vol 72 (3) ◽  
pp. 204-207 ◽  
Author(s):  
A. Béné ◽  
A. Hayman ◽  
E. Reynard ◽  
J.L. Luisier ◽  
J.C. Villettaz
Keyword(s):  
Rapid Determination ◽  
Direct Method ◽  
New Method ◽  
Volatile Substances

scholarly journals A Direct Method to Compare Bipolar LR Fuzzy Numbers

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Reza Ghanbari ◽  
Khatere Ghorbani-Moghadam ◽  
Nezam Mahdavi-Amiri
Keyword(s):  
Fuzzy Number ◽  
Fuzzy Numbers ◽  
Direct Method ◽  
Optimization Algorithms ◽  
Real Life ◽  
New Method ◽  
Triangular Fuzzy Numbers ◽  
Real Life Problem ◽  
A Direct Method

We propose a new method for ordering bipolar fuzzy numbers. In this method, for comparison of bipolar LR fuzzy numbers, we use an extension of Kerre’s method being used in ordering of unipolar fuzzy numbers. We give a direct formula to compare two bipolar triangular fuzzy numbers in O(1) operations, making the process useful for many optimization algorithms. Also, we present an application of bipolar fuzzy number in a real life problem.

scholarly journals A New Direct Method for Solving Nonlinear Volterra-Fredholm-Hammerstein Integral Equations via Optimal Control Problem

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
M. A. El-Ameen ◽  
M. El-Kady
Keyword(s):  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Integral Equations ◽  
Simple Form ◽  
Existence And Uniqueness ◽  
Direct Method ◽  
New Method ◽  
Fredholm Integral Equations ◽  
Hammerstein Integral Equations

A new method for solving nonlinear Volterra-Fredholm-Hammerstein (VFH) integral equations is presented. This method is based on reformulation of VFH to the simple form of Fredholm integral equations and hence converts it to optimal control problem. The existence and uniqueness of proposed method are achieved. Numerical results are given at the end of this paper.

A new method for the rapid determination of volatile substances: the SPME-direct method

2001 ◽  
Vol 72 (2) ◽  
pp. 184-187 ◽  
Author(s):  
Alexandre Béné ◽  
Antoine Fornage ◽  
Jean-Luc Luisier ◽  
Peter Pichler ◽  
Jean-Claude Villettaz
Keyword(s):  
Rapid Determination ◽  
Direct Method ◽  
New Method ◽  
Volatile Substances
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