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A Partial Discharge Fault Identification Algorithm based on SGWT Neural Network
Wei Zhang,Qiuli Wu,Yurong Deng 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5
Based on the second generation wavelet and information entropy, in this paper, we recognize the partial discharge pattern using the second generation wavelet (SGWT) and adaptive BP. Firstly, feature extraction of discharge signals are obtained using the SGWT and information entropy. Then, the extracted features are feed into the training BP network. The learning algorithm employed the conjugate gradient methods and the adaptive adjustment to train the error for BP network. Finally, we get the optimum training network, and the simulation results verified the feasibility of the algorithm.
Wei Zhang,Yan-Chun Zhu,Li-Hua Wu 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.3
Price wars are a major form of competition for Chinese online retailers. Based on empirical data from online retailers, JD Mall, Amazon(Z.cn) and Dangdang, this study explored the price competition in China's B2C e-commerce market. The average price level, the minimum price level, the price differential level and price variation were considered. The results showed that the average price levels between the three e-commerce websites had statistically significant differences. However, the minimum price level and the price differential level were similar. In terms of the price variation, the three websites adopted different price adjustments and did their best to avoid a direct price war. This suggests that the e-commerce market competition in China is becoming rational.
Joint Mode Selection, Link Allocation and Power Control in Underlaying D2D Communication
( Wei Zhang ),( Wanbing He ),( Dan Wu ),( Yueming Cai ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.11
Device-to-device (D2D) communication underlaying cellular networks can bring significate benefits for improving the performance of mobile services. However, it hinges on elaborate resource sharing scheme to coordinate interference between cellular users and D2D pairs. We formulate a joint mode selection, link allocation and power control optimization problem for D2D communication sharing uplink resources in a multi-user cellular network and consider the efficiency and the fairness simultaneously. Due to the non-convex difficulty, we propose a three-step scheme: firstly, we conduct mode selection for D2D pairs based on a minimum distance metric after an admission control and obtain some cellular candidates for them. And then, a cellular candidate will be paired to each D2D pair based on fairness. Finally, we use Lagrangian Algorithm to formulate a joint power control strategy for D2D pairs and their reused cellular users and a closed-form of solution is derived. Simulation results demonstrate that our proposed algorithms converge in a short time. Moreover, both the sum rate of D2D pairs and the energy efficiency of cellular users are improved.
( Wei Zhang ),( Yi Wu ),( Hu Xiong ),( Zhiguang Qin ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.1
In the system of ciphertext policy attribute-based encryption (CP-ABE), only when the attributes of data user meets the access structure established by the encrypter, the data user can perform decryption operation. So CP-ABE has been widely used in personal health record system (PHR). However, the problem of key abuse consists in the CP-ABE system. The semi-trusted authority or the authorized user to access the system may disclose the key because of personal interests, resulting in illegal users accessing the system. Consequently, aiming at two kinds of existing key abuse problems: (1) semi-trusted authority redistributes keys to unauthorized users, (2) authorized users disclose keys to unauthorized users, we put forward a CP-ABE scheme that has authority accountability, user traceability and supports arbitrary monotonous access structures. Specifically, we employ an auditor to make a fair ruling on the malicious behavior of users. Besides, to solve the problem of user leaving from the system, we use an indirect revocation method based on trust tree to implement user revocation. Compared with other existing schemes, we found that our solution achieved user revocation at an acceptable time cost. In addition, our scheme is proved to be fully secure in the standard model.
Wei Zhang,Yan Chun Zhu,Li Hua Wu 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4
The price war is the main market competition way for Chinese e-commerce retailers. Based on the price data from JD, Amazon and Dangdang, the paper conducted an empirical research on the price competition in B2C e-commerce market in China in terms of the average price level, minimum price level, price differential level and price variation. The research results show that the average price levels between the three e-commerce websites have significant differences. The minimum price level and the price differential level, however, tend to be similar. For the price variation, the three websites adopt different price adjustment strategies and do their best to avoid the direct price war, which reveals that the e-commerce market competition in China is gradually becoming rational.