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Shijiazhuang, China

Zhang H.,Tianjin Polytechnic University | Hou Y.,Hebei Academy of Governance | Sui X.,Tianjin Polytechnic University
China Welding (English Edition) | Year: 2013

The electrode displacement signal of the resistance spot welding process is monitored and mapped into a binary matrix. Some welded spots, from different welding current specifications, are classified into five classes according to the prototypes of the pattern matrices. A reliable quality classifier is developed based on Hopfield network when the tensile shear strength of the welded joint is measured as the quality indicator. The cross validation test results show that the method utilizing pattern matrix of the displacement signal to characterize nugget formation process is feasible and it can provide adequate quality information of the welded spot. At the same time, under small sample circumstance, the classifier presents good classification ability and it also can correctly estimate the weld quality in some abnormal welding process according to the pattern feature of the displacement signal. © 2013 Editorial Board of CHINA WELDING.

Kun G.,Hebei Academy of Governance | Sumei J.,Hebei University of Economics and Business
ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings | Year: 2010

Previously, people's attention to information security focused on protection module, but with the system vulnerability assessment and intrusion detection work in-depth, detection module is also gaining attention. This paper researches the Agent technology and analyzes the characteristics and architecture of it. Finally this paper proposes the advantages and disadvantages to apply the mobile agent technology to intrusion detection systems, and points out the research direction of the intrusion detection systems based on mobile agent technology. © 2010 IEEE.

Han X.,University of International Business and Economics | Han X.,Hebei Academy of Governance | Liu S.,University of International Business and Economics
Mathematical Problems in Engineering | Year: 2015

We analyze the generalized first-price auction under incomplete information setting. Without setting a reserve price, the efficient symmetrical Bayes-Nash equilibrium is characterized and found to be increasing as the number of bidders is sufficiently large. Then, the explicit expression for the expected revenue of the search engine is found and the effect of the click rates of all the positions on the expected revenue is obtained. Finally, with setting of the reserve price, we have found the optimal reserve price and examine how the difference of the search engine's revenues with setting reserve price and without setting reserve price varies with the reserve price. © 2015 Xiaohu Han and Shulin Liu.

Zhang H.J.,Tianjin Polytechnic University | Wang F.J.,Tianjin University | Gao W.G.,Tianjin University | Hou Y.Y.,Hebei Academy of Governance
Science and Technology of Welding and Joining | Year: 2014

To improve the efficiency of acquiring monitored features and present a reliable quality assessment method for resistance spot welding, a novel method for converting the electrode displacement signal into binary image is proposed. The probabilistic neural network is adopted to provide a probabilistic viewpoint and a deterministic classification result of weld quality when the image characteristic of displacement signal is selected as monitored features. Test results of the classifier demonstrate that it is feasible and reliable to utilise binary image of the displacement signal to evaluate weld quality. The method reserves weld quality information as much as possible and it avoids complex algorithm for extracting and selecting monitored features. At the same time, when there are small samples, the classifier can identify good or bad weld rapidly and accurately even though the weld is from abnormal welding process, such as expulsion, current shunting and small edge distance condition. © 2014 Institute of Materials, Minerals and Mining.

Zhang H.,Tianjin Polytechnic University | Hou Y.,Hebei Academy of Governance | Zhang J.,Tianjin Polytechnic University | Qi X.,Tianjin Polytechnic University | Wang F.,Tianjin University
International Journal of Advanced Manufacturing Technology | Year: 2015

To develop an effective nondestructive evaluation method for the welding quality of the resistance spot welding, the electrode displacement signal during the resistance spot welding process is monitored, and the acquisition data of the signal are innovatively presented as the radar chart format. Some geometric features of the radar charts are extracted to reflect the welding quality. The decision tree classification technique is adopted to build a classifier and to provide a visible and intuitive diagnostic procedure for welding quality assessment. Test results of the decision tree classifier show that it is feasible and reliable to evaluate weld quality based on the graphics features of the radar chart. The features and the weld quality are closely related, and their extraction avoids complex algorithm. Meanwhile, when there are small samples, the decision tree classifier can identify good or bad weld accurately and rapidly, even though the weld is from an abnormal welding process, such as expulsion, current shunting, greasy surface, and small edge distance condition. © 2014, Springer-Verlag London.

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