A Novel Approach of Crack Detection in Railway Track using Fuzzy C Means and Level Set Method

2020 ◽  
Author(s):  
Chetan Vasant Chaudhari ◽  
Ravindra Kumar Gupta ◽  
Sapana A. Feagade
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Crack Detection ◽  
Railway Track ◽  
Fuzzy C Means ◽  
Novel Approach

TRACKING MULTIPLE MOVING OBJECTS USING A LEVEL-SET METHOD

2004 ◽  
Vol 18 (02) ◽  
pp. 101-125 ◽  
Author(s):  
CHIA-JUNG CHANG ◽  
JUN-WEI HSIEH ◽  
YUNG-SHENG CHEN ◽  
WEN-FONG HU
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Moving Objects ◽  
Video Content ◽  
Subtraction Technique ◽  
Object Boundary ◽  
Novel Approach ◽  
Compensation Technique ◽  
Speed Function ◽  
Edge Based

This paper presents a novel approach to track multiple moving objects using the level-set method. The proposed method can track different objects no matter if they are rigid, nonrigid, merged, split, with shadows, or without shadows. At the first stage, the paper proposes an edge-based camera compensation technique for dealing with the problem of object tracking when the background is not static. Then, after camera compensation, different moving pixels can be easily extracted through a subtraction technique. Thus, a speed function with three ingredients, i.e. pixel motions, object variances and background variances, can be accordingly defined for guiding the process of object boundary detection. According to the defined speed function, different object boundaries can be efficiently detected and tracked by a curve evolution technique, i.e. the level-set-based method. Once desired objects have been extracted, in order to further understand the video content, this paper takes advantage of a relation table to identify and observe different behaviors of tracked objects. However, the above analysis sometimes fails due to the existence of shadows. To avoid this problem, this paper adopts a technique of Gaussian shadow modeling to remove all unwanted shadows. Experimental results show that the proposed method is much more robust and powerful than other traditional methods.

A Novel Approach for Color Tongue Image Fast Segmentation Based on Level Sets

2011 ◽  
Vol 341-342 ◽  
pp. 714-719 ◽  
Author(s):  
Ming Feng Zhu ◽  
Jian Qiang Du
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Level Sets ◽  
Step Method ◽  
Time Step ◽  
Novel Approach ◽  
Feature Weight ◽  
Variational Level Set ◽  
Variable Time Step ◽  
Variational Level Set Method

To make variational level set method applicable to the application of tongue segmentation, this article introduced a kind of color tongue image fast segmentation method based on level sets. The early variational level set method is improved from the following aspects: the boundary feature weight function is improved to make this method adaptable to color tongue image segmentation, and a kind of variable time step method is introduced to increase the efficiency and accuracy of segmentation. As the comparison experiment results show, our method is about 1 time faster than the early method, and its accuracy is higher than the early one.

A novel approach of input tolerance design for parallel mechanisms using the level set method

2019 ◽  
Vol 234 (3) ◽  
pp. 371-381 ◽  
Author(s):  
Qiangqiang Zhao ◽  
Junkang Guo ◽  
Dewen Yu ◽  
Jun Hong ◽  
Zhigang Liu
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Degrees Of Freedom ◽  
Work Performance ◽  
Tolerance Design ◽  
Parallel Mechanisms ◽  
Output Error ◽  
Novel Approach ◽  
Normal Speed ◽  
Input Error

Input uncertainties inevitably result in the output error for parallel mechanisms, which will lead to significant influence on good work performance. To control the output error within the specification boundary, this article proposes a novel approach of input tolerance design based on the level set method for the driving joint. The implementation of the proposed method can be divided into two subtasks. First, using the level set method, the exact input error boundary is determined by means of evolving an initial input error interface with a defined normal speed field, thereby transforming the problem of exploring the exact boundary into solving a partial differential equation with initial value. On this basis, according to the equal and scaled principles, the tolerance width of each input is evaluated in an intuitionally geometrical manner, that is, searching the maximum geometry corresponding to the principle inside the exact input error boundary. Finally, two planar parallel mechanisms with different degrees of freedom are introduced as numerical examples to demonstrate the execution and effectiveness of the proposed method.

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