An Improved Water Surface Images Segmentation Algorithm Based on the Otsu Method

2020 ◽  
Vol 29 (15) ◽  
pp. 2050251
Author(s):  
Ning Li ◽  
Xin Lv ◽  
Shoukun Xu ◽  
Bo Li ◽  
Yuwan Gu
Keyword(s):  
Water Surface ◽  
Evaluation Method ◽  
Threshold Method ◽  
Threshold Segmentation ◽  
One Dimensional ◽  
Otsu Method ◽  
Segmentation Accuracy ◽  
Surface Image ◽  
Performance Evaluation Method ◽  
The One

The one-dimensional Otsu method is an adaptive threshold method. It obtains the optimal threshold for image segmentation by the maximum between-class variance, without considering the minimum within-class variance. As the background of water surface image is mostly uniform, using this feature, the threshold selection tactics adopt the combination of the one-dimensional Otsu method and the uniformity measurement, proposes the threshold segmentation method based on uniformity measurement, and adopts the performance evaluation method based on GT image to compare the segmentation result. Experimental results demonstrate that effectiveness of the improved Otsu method is generally better than the traditional Otsu method, and the other four commonly used threshold segmentation methods for the water surface image, which improves the segmentation accuracy of such images and reduces the segmentation error rate. At the same time, as the water surface image is usually affected by light intensity, water ripple and other factors, this paper also adopts the relevant correction algorithm to further improve the segmentation accuracy.

scholarly journals Effects of geologic outcrops on long-term geomorphic trends : New Madrid, MO, to Hickman, KY

2021 ◽  
Author(s):  
Travis Dahl ◽  
Justin Giles ◽  
Kathleen Staebell ◽  
David Biedenharn ◽  
Joseph Dunbar
Keyword(s):  
Mississippi River ◽  
Water Surface ◽  
Hydraulic Modeling ◽  
Shear Stresses ◽  
High Shear ◽  
One Dimensional ◽  
Surface Profiles ◽  
The One ◽  
New Madrid

The Mississippi River between New Madrid, MO, and Hickman, KY, is of particular interest because of divergent trends in water surface profiles at the upstream and downstream ends of the reach. This report documents the investigation of the bathymetry, geology, and hydraulics of this segment of the river. The report shows that the area near River Mile 901 above Head of Passes strongly affects the river stages at low flows. This part of the river can experience high shear stresses when flows fall below 200,000 cfs, as opposed to most other locations where shear stress increases with flow. One-dimensional hydraulic modeling was also used to demonstrate that an increase of depth at a single scour hole, such as the one downstream from Hickman near River Mile 925, is unlikely to cause reach-wide degradation.

scholarly journals Airfoils moving in air close to a dynamic water surface

1986 ◽  
Vol 27 (3) ◽  
pp. 327-345 ◽  
Author(s):  
I. H. Grundy
Keyword(s):  
Integral Equation ◽  
Potential Flow ◽  
Water Surface ◽  
Linear Integral Equation ◽  
One Dimensional ◽  
Short Waves ◽  
The One ◽  
Linear Integral ◽  
Parameter Ranges ◽  
Steady Potential

AbstractSteady potential flow about a thin wing, flying in air above a dynamic water surface, is analysed in the asymptotic limit as the clearance-to-length ratio tends to zero. This leads to a non-linear integral equation for the one-dimensional pressure distribution beneath the wing, which is solved numerically. Results are compared with established “rigid-ground” and “hydrostatic” theories. Short waves lead to complications, including non-uniqueness, in some parameter ranges.

scholarly journals BORE FRONT MODELING IN TERMS OF BURGERS EQUATION AND ITS NUMERICAL CALCULATION METHOD

1988 ◽  
Vol 1 (21) ◽  
pp. 192
Author(s):  
Takao Yamashita ◽  
Yoshito Ysuchiya ◽  
David R. Basco
Keyword(s):  
Numerical Calculation ◽  
Water Surface ◽  
Open Channel ◽  
Burgers Equation ◽  
Equation System ◽  
Diffusion Term ◽  
One Dimensional ◽  
The One ◽  
Numerical Calculation Method ◽  
Front Dynamics

Bore front hydraulics are investigated in terms of Burgers equation to clarify the dynamics of a moving discontinuity in water flow. Burgers equation has been derived from the one dimensional open channel equation with the horizontal turbulent diffusion term. The derived equation system consists of Burgers with respect to dynamic characteristic and hyperbolic equation with respect to water surface elevation, which satisfys Jeffery-Vedernikov condition FT — 2 through discontinuity. It has been verified from the experiments that the condition FT = 2 is a good approximation of bore front dynamics. The numercal calulation method of Burgers equation employing Cole-Hopf transformation and QUICKEST algorithm was also proposed and confirmed its efficiency.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

Modelling Techniques in Applied Glaciology: Numerical Modelling of Avalanches

1983 ◽  
Vol 4 ◽  
pp. 297-297
Author(s):  
G. Brugnot
Keyword(s):  
Finite Difference Method ◽  
Transverse Velocity ◽  
Longitudinal Velocity ◽  
Momentum Conservation ◽  
Dimensional Model ◽  
One Dimensional ◽  
Modelling Techniques ◽  
Reference Grid ◽  
The One ◽  
Near Future

We consider the paper by Brugnot and Pochat (1981), which describes a one-dimensional model applied to a snow avalanche. The main advance made here is the introduction of the second dimension in the runout zone. Indeed, in the channelled course, we still use the one-dimensional model, but, when the avalanche spreads before stopping, we apply a (x, y) grid on the ground and six equations have to be solved: (1) for the avalanche body, one equation for continuity and two equations for momentum conservation, and (2) at the front, one equation for continuity and two equations for momentum conservation. We suppose the front to be a mobile jump, with longitudinal velocity varying more rapidly than transverse velocity.We solve these equations by a finite difference method. This involves many topological problems, due to the actual position of the front, which is defined by its intersection with the reference grid (SI, YJ). In the near future our two directions of research will be testing the code on actual avalanches and improving it by trying to make it cheaper without impairing its accuracy.

Sign in / Sign up

Export Citation Format

Share Document