scholarly journals Sliding Dispersion Entropy-Based Fault State Detection for Diaphragm Pump Parts

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1536
Author(s):  
Chengjiang Zhou ◽  
Yunhua Jia ◽  
Haicheng Bai ◽  
Ling Xing ◽  
Yang Yang
Keyword(s):  
Detection Method ◽  
Check Valve ◽  
Sliding Window ◽  
The State ◽  
Sigmoid Function ◽  
Noise Performance ◽  
Signal Distribution ◽  
Mechanical Parts ◽  
State Detection ◽  
Fault State

Aiming at the disadvantages of low trend, poor characterization performance, and poor anti-noise performance of traditional degradation features such as dispersion entropy (DE), a fault detection method based on sliding dispersion entropy (SDE) is proposed. Firstly, a sliding window is added to the signal before extracting the DE feature, and the root mean square of the signal inside the sliding window is used to replace the signal in the window to realize down sampling, which enhances the trend of DE. Secondly, the hyperbolic tangent sigmoid function (TANSIG) is introduced to map the signals to different categories when extracting the DE feature, which is more in line with the signal distribution of mechanical parts and the monotonicity of the degradation feature is improved. For noisy signal, the introduction of locally weighted scatterplot smoothing (LOWESS) can remove the burrs and fluctuations of the SDE curve, and the anti-noise performance of SDE is improved. Finally, the SDE state warning line is constructed based on the 2σ criterion, which can determine the fault warning point in time and effectively. The state detection results of bearing and check valve show that the proposed SDE improves the trend, monotonicity, and robustness of the state tracking curve, and provides a new method for fault state detection of mechanical parts.

scholarly journals Random Forest with Adaptive Local Template for Pedestrian Detection

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Tao Xiang ◽  
Tao Li ◽  
Mao Ye ◽  
Zijian Liu
Keyword(s):  
Computer Vision ◽  
Random Forest ◽  
Classification Accuracy ◽  
Template Matching ◽  
Detection Method ◽  
State Of The Art ◽  
Pedestrian Detection ◽  
Sliding Window ◽  
Experimental Results ◽  
Training Samples

Pedestrian detection with large intraclass variations is still a challenging task in computer vision. In this paper, we propose a novel pedestrian detection method based on Random Forest. Firstly, we generate a few local templates with different sizes and different locations in positive exemplars. Then, the Random Forest is built whose splitting functions are optimized by maximizing class purity of matching the local templates to the training samples, respectively. To improve the classification accuracy, we adopt a boosting-like algorithm to update the weights of the training samples in a layer-wise fashion. During detection, the trained Random Forest will vote the category when a sliding window is input. Our contributions are the splitting functions based on local template matching with adaptive size and location and iteratively weight updating method. We evaluate the proposed method on 2 well-known challenging datasets: TUD pedestrians and INRIA pedestrians. The experimental results demonstrate that our method achieves state-of-the-art or competitive performance.

scholarly journals Simulation Model and State Analysis of Ship Transmission Line

2018 ◽  
Vol 25 (s3) ◽  
pp. 36-42
Author(s):  
Yanzhe Hu ◽  
Mengjie Xu ◽  
Yang Li
Keyword(s):  
Transmission Line ◽  
Simulation Model ◽  
Normal State ◽  
Short Circuit ◽  
The State ◽  
Sudden Increase ◽  
Line System ◽  
Voltage Signal ◽  
Fault State ◽  
Sudden Load

Abstract In order to discuss the simulation model of the ship transmission line and the state of the transmission line, an early fault model is built according to the evolution principle of the short circuit fault of the transmission line and combining with the fault characteristics of the early fault. A small distributed ship transmission line system is built in MATLAB/ Simulink. Then, combined with the constructed fault module, the original short circuit module, and the load module, the various states (normal state, early fault state, severe early fault state, short circuit state) of the ship transmission line are stimulated, and the features of voltage signal in each state is analysed. It is concluded that, due to the normal operation of the ship transmission line system, the variation characteristics of the flow signal and voltage signal caused by the sudden load mutation, that is, the sudden load and the sudden increase load, are very similar to the changes caused by the early fault. Therefore, in order to find a more accurate early fault detection method, the state is divided into normal state, sudden load state, sudden increase and sudden decrease load state.

Host–Based Intrusion Detection Systems

2014 ◽  
pp. 184-213
Author(s):  
Vít Bukač ◽  
Vashek Matyáš
Keyword(s):  
Intrusion Detection ◽  
Detection Method ◽  
State Of The Art ◽  
Research Trends ◽  
The State ◽  
Intrusion Detection Systems ◽  
Future Directions ◽  
Detection Systems ◽  
Research Findings ◽  
Art Research

In this chapter, the reader explores both the founding ideas and the state-of-the-art research on host-based intrusion detection systems. HIDSs are categorized by their intrusion detection method. Each category is thoroughly investigated, and its limitations and benefits are discussed. Seminal research findings and ideas are presented and supplied with comments. Separate sections are devoted to the protection against tampering and to the HIDS evasion techniques that are employed by attackers. Existing research trends are highlighted, and possible future directions are suggested.

scholarly journals Real-Time Docking Ring Detection Based on the Geometrical Shape for an On-Orbit Spacecraft

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5243
Author(s):  
Zhang ◽  
Pan ◽  
Ma
Keyword(s):  
Least Squares ◽  
Real Time ◽  
Detection Method ◽  
State Of The Art ◽  
The State ◽  
Selection Strategy ◽  
Geometrical Shape ◽  
Automatic Capture ◽  
Rendezvous And Docking ◽  
Real Time Application

Docking ring is a circular hatch of spacecraft that allows servicing spacecraft to dock in various space missions. The detection of the ring is greatly beneficial to automatic capture, rendezvous and docking. Based on its geometrical shape, we propose a real-time docking ring detection method for on-orbit spacecraft. Firstly, we extract arcs from the edge mask and classify them into four classes according to edge direction and convexity. By developing the arc selection strategy, we select a combination of arcs possibly belonging to the same ellipse, and then estimate its parameters via the least squares fitting technique. Candidate ellipses are validated according to the fitness of the estimation with the actual edge pixels. The experiments show that our method is superior to the state-of-the-art methods, and can be used in real time application. The method can also be extended to other applications.

Research on ASIC Firewall Based on State Detection Technology

2014 ◽  
Vol 644-650 ◽  
pp. 3283-3286 ◽  
Author(s):  
Shun Qing Wang ◽  
Hai Yan Chen
Keyword(s):  
Network Security ◽  
Computer Networks ◽  
Technology Implementation ◽  
High Performance ◽  
The State ◽  
Real Network ◽  
Design And Implementation ◽  
Detection Technology ◽  
State Detection

Being important in the field of network security, it is essential to study the firewall technology that has been an indispensable part of computer networks. This paper describes a new design and implementation of ASIC firewall architecture based on the state detection technology. Implementation and measurements in a real network show that the proposed system can provide high performance with reliability, flexibility, and security.

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