Application of v-shaped magnet in inner surface polishing of tubes

Yaoming Zhang,Wen Jia,Yan Chen 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.9

Compared to traditional polishing processes, the magnetic grinding method allows relatively easy polishing of the inner surface of tube fittings. For more than 7 mm thickness SUS304 tubes, the magnetic abrasive grains are subject to a small magnetic force and grinding pressure, leading to the low polishing efficiency. Therefore, a new magnetic grinding and polishing method is proposed, in which the grooved V-shaped magnet is conductive to spontaneous mixing and stirring with magnetic abrasive grains, allowing them continually being replaced for inner surfaces polishing on the tube. This can increase the grinding pressure of abrasive grains to the inner surface and contribute to high-quality surface polishing. Theoretically, it was proved that the grooved V-shaped magnet-assisted polishing tool improves the uniformity of material cutting force in the polishing process. Finally, this method was validated by the experiment with the 7 mm thickness SUS304 tube.

Research on Starting Clutch Control Strategy of Unmanned Helicopter

Zhou Yaoming,Zhang Lei,Xu Hongzhe,Wu Zhe 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

A method is explored to realize automatic control of starting clutch. The clutch control requirements are determined based on the dynamics characteristics research of an unmanned helicopter clutch, and the analysis of clutch engagement process effect on transmission impact and belts life. The rotating speed of clutch driving pulley and driven pulley are selected as basic input parameters. The starting clutch engagement control is divided into three stages. The three stages are fast engagement before rotor rotates, slow engagement and fast engagement after synchronization in turn. Subsection algorithm is adopted in fast engagement before rotor rotates. PID algorithm is adopted in slow engagement. The automatic control of starting clutch engagement at various operating conditions is realized in this way. The experimental results indicate that this control strategy can fit the changes of clutch parameters. It is proved that this clutch control strategy has met the autonomous control requirements of unmanned helicopter.

Gear fault identification and classification of singular value decomposition based on Hilbert-Huang transform

Zhongyuan Su,Yaoming Zhang,Minping Jia,Feiyun Xu,Jianzhong Hu 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.2

An improved singular value decomposition method of gear fault identification based on Hilbert-Huang transform was proposed to overcome the problem of reconstructing a feature matrix of singular value decomposition. The method includes three steps. First, the instantaneous frequency and amplitude matrices were acquired by Hilbert-Huang transform from faulted gear signals. Second, after the matrices were decomposed by singular value decomposition, the defined distances of singular value vectors and the optimal threshold of the distance for classification were calculated. Third, the fault characteristics of a gearbox were identified and classified by the threshold of the distances. The result demonstrates that the proposed method effectively identifies the gear fault and can realize an automatic gear fault diagnosis.

Parallel Joint Fingerprinting and Encryption for Social Multimedia Sharing Based on Game of Life

Conghuan Ye,Zenggang Xiong,Yaoming Ding,Xuemin Zhang,Guangwei Wang,Fang Xu,Kaibing Zhang 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.7

The advent of online social network and mobile multimedia communication has made content sharing in social network easier and more efficient. It is very important to combine fingerprinting and encryption for social multimedia content protection. In this paper, a parallel JFE (joint fingerprinting and encryption) framework is proposed. Firstly, the multi-level social fingerprint code is produced using social network analysis, and followed by TSH (tree structure harr) wavelet decomposition for multimedia content. And then, fingerprints are embedded into all the LL, HL and LH subbands parallelly. At last, GoL(Game of Life) are used to for confusion for wavelet coefficients parallelly. The proposed parallel JFE method, to the best of our knowledge, is the first JFE method using GoL in the TSH wavelet domain for security and privacy. Theory analysis and experimental results demonstrate the effectiveness of the proposed JFE scheme.

Joint Fingerprinting/Encryption for Medical Image Security

Conghuan Ye,Zenggang Xiong,Yaoming Ding,Xueming Zhang,Guangwei Wang,Fang Xu 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Electronic health records (EHRs) facilitates the healthcare process. However, it can also cause serious security and privacy problems. While various conventional encryption mechanisms can solve some aspects of these problems, they cannot address the illegal distribution of decrypted medical images. To protect decrypted medical images from being illegally distributed by an authorized staff member, the scheme proposed in this paper provides a joint fingerprinting and encryption (JFE) scheme based on GoL (Game of Life) and DNA computing with the purpose of protecting medical media distribution. In this study, GoL and DNA are used to confuse in DWT domain and diffusion in spatial domain respectively, and fingerprints are embedded into the HL and LH subbands of DWT domain. The use of fingerprinting along with encryption can provide a double-layer of protection to medical image. Experimental results show the effectiveness of the proposed scheme.

A New Collusion Attack Using Interpolation for Multimedia Fingerprinting

Conghuan Ye,Zenggang Xiong,Yaoming Ding,Xuemin Zhang,Guangwei Wang,Fang Xu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.5

Digital fingerprinting is a special digital watermarking technology that can deter legal user to redistribute multimedia content to others. With traitor tracing, it can detect illegal users who use multimedia content illegally. However, collusion attack can avoid some illegal users being detected. With different fingerprinted copies, collusion attack can produce a new colluded fingerprinted copy for get rid of the fingerprint information from the colluded copy, so digital fingerprinting technique should deter collusion attacks. In order to improve the performance of new digital fingerprinting technique in future, this paper presents a new collusion attack approach based on interpolation. The proposed interpolation collusion attack scheme comes from the idea of image fusion. The experimental results demonstrate that the proposed interpolation collusion attack method outperform average attack and maximum attack.

Secure Multimedia Content Distribution for M2M Communication

Conghuan Ye,Zenggang Xiong,Yaoming Ding,Xuemin Zhang,Guangwei Wang,Fang Xu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.4

Multimedia content distribution based on M2M communication is attracting increasing attentions nowadays. Considering that multimedia will be widely used in various applications over M2M network, the wide range of multimedia content and M2M devices has raised new security requirements for multimedia communication. In this paper, we focus on an aspect of DRM that involves secure multimedia distribution which combines multimedia encryption, copy detection, and digital fingerprinting to prevent widespread piracy. Multimedia encryption is used to encrypt multimedia content firstly before distribution, then, Copy detection is used to verify whether a protected multimedia content is a redistributed copy of its or no, At last, digital fingerprinting is introduced to protect multimedia content further. In this paper, we first use using encryption, fingerprinting and copy detection for secure distribution in M2M communication environments. The secure effect of the proposed scheme has been verified through theory analysis and experimental results.

Joint Fingerprinting and Encryption in the DWT Domain for Secure M2M Communication

Conghuan Ye,Zenggang Xiong,Yaoming Ding,Xueming Zhang,Guangwei Wang,Fang Xu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.1

Machine-to-machine (M2M) communication is viewed as one of the next frontiers in wireless communications. Because of unguarded communication, new security threats emerge. Considering that multimedia will be widely used in various applications over M2M network, it is very urgent to meet new security requirements for multimedia communication. This paper focuses on a joint fingerprinting and encryption (JFE) scheme in the DWT domain with the purpose of protecting multimedia distribution. A multimedia encryption scheme is first to scramble the multimedia content before distribution, and the fingerprinting scheme is then introduced to provide further protection. The goal of the proposed content distribution scheme is to provide secure content communication and deter the device from illegally redistributing the content. The proposed method, to the best of our knowledge, is the first JFE method in the DWT domain for secure M2M communication. The use of fingerprinting along with encryption can provide a double-layer of protection to digital media. Theory analysis and experimental results show the effectiveness of the proposed scheme.

SPATIAL COHERENCE OF SOUND IN THE CONVERGENCE ZONES

Dinghua GUAN,Ruichao ZHU,Renhe ZHANG,Yaoming CHEN 한국소음진동공학회 1994 한국소음진동공학회 국제학술대회논문집 Vol.1994 No.3

Exendin-4 ameliorates high glucoseinduced fibrosis by inhibiting the secretion of miR-192 from injured renal tubular epithelial cells

Yijie Jia,Zongji Zheng,Meiping Guan,Qian Zhang,Yang Li,Ling Wang,Yaoming Xue 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Extracellular vesicles (EVs), which contain microRNA (miRNA), constitute a novel means of cell communication that may contribute to the inevitable expansion of renal fibrosis during diabetic kidney disease (DKD). Exendin-4 is effective for treating DKD through its action on GLP1R. However, the effect of exendin-4 on EV miRNA expression and renal cell communication during the development of DKD remains unknown. In this study, we found that EVs derived from HK-2 cells pre-treated with exendin-4 and high glucose (Ex-HG), which were taken up by normal HK-2 cells, resulted in decreased levels of FN and Col-I compared with EVs from HK-2 cells pre-treated with HG alone. Furthermore, we found that pretreatment with HG and exendin-4 may have contributed to a decrease in miR-192 in both HK-2 cells and EVs in a p53-dependent manner. Finally, we demonstrated that the amelioration of renal fibrosis by exendin-4 occurred through a miR-192-GLP1R pathway, indicating a new pathway by which exendin-4 regulates GLP1R. The results of this study suggest that exendin-4 inhibits the transfer of EV miR-192 from HG-induced renal tubular epithelial cells to normal cells, thus inhibiting GLP1R downregulation and protecting renal cells. This study reports a new mechanism by which exendin-4 exerts a protective effect against DKD.