Research on the Power Sharing Control and Stability of VSGs

Dong Xie,Da-Jin Zang,Peng Gao,Jun-Jia Wang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Aiming at the deficiencies of power sharing control performances when a traditional droop control is adopted for microgrid inverters, this paper proposes a microgrid inverter power sharing control strategy based on a virtual synchronous generator. This control method simulates the electromechanical transient characteristics of a synchronous generator in a power system by an ontology algorithm and the control laws of a synchronous generator by control over the speed governor and excitation regulator. As a result, that the microgrid system is able to effectively retain the stability of the voltage and frequency, and the power sharing precision of the microgrid inverter is improved. Based on an analysis of stability of a microgrid system controlled by a virtual synchronous generator, design thoughts are provided for further improvement of the power sharing precision of inverters. The simulation results shows that when the virtual synchronous generator based control strategy was adopted, the power sharing performances of microgrid inverters are improved more obviously than those using the droop control strategy.

Efficient Post-Quantum Secure Network Coding Signatures in the Standard Model

( Dong Xie ),( Haipeng Peng ),( Lixiang Li ),( Yixian Yang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

In contrast to traditional “store-and-forward” routing mechanisms, network coding offers an elegant solution for achieving maximum network throughput. The core idea is that intermediate network nodes linearly combine received data packets so that the destination nodes can decode original files from some authenticated packets. Although network coding has many advantages, especially in wireless sensor network and peer-to-peer network, the encoding mechanism of intermediate nodes also results in some additional security issues. For a powerful adversary who can control arbitrary number of malicious network nodes and can eavesdrop on the entire network, cryptographic signature schemes provide undeniable authentication mechanisms for network nodes. However, with the development of quantum technologies, some existing network coding signature schemes based on some traditional number-theoretic primitives vulnerable to quantum cryptanalysis. In this paper we first present an efficient network coding signature scheme in the standard model using lattice theory, which can be viewed as the most promising tool for designing post-quantum cryptographic protocols. In the security proof, we propose a new method for generating a random lattice and the corresponding trapdoor, which may be used in other cryptographic protocols. Our scheme has many advantages, such as supporting multi-source networks, low computational complexity and low communication overhead.

A New Pyrrolizidine Alkaloid from Senecio vulgaris

Xie, Wei-Dong,Li, Xia,Row, Kyung-Ho Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

A New C-10 Acetylene and A New Triterpenoid from Conyza canadensis

Xie, Wei-Dong,Gao, Xue,Jia, Zhong Jian 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.5

From the whole plants of Conyza canadensis (Compositae), a new C-10 acetylene, namely 8R, 9R-dihydroxymatricarine methyl ester (1), and a new triterpenoid, namely 3${\beta}$ 16${\beta}$, 20${\beta}$-trihydroxytaraxast-3-O-palmitoxyl ester (4), were isolated along with eleven known compounds(2, 3, 5-13). The structures of all 13 compounds were elucidated on the basis of their spectral data. The antibacterial activities of compounds 1-3 were evaluated.

Modeling errors forming abnormal tool marks on a twisted ruled surface in flank milling of the five-axis CNC

Dong Xie,Jiexiong Ding,Fumin Liu,Zhong Jiang,Li Du,Wei Wang,Zhiyong Song 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.11

The complex surface machining quality is related to the capacity of the control system, servo drive and mechanical transmission infive-axis CNC machining. The unsuitable parameters result in surface contour errors and other processing abnormal phenomena such astool marks and corrugated surface. In this paper a twisted ruled surface in flank milling is analyzed. The construction features of surfaceand the tool path characteristic of the specimen are listed. The surface cutting velocity is deduced considering the constraints of the acceleration,jerk and other control parameters and the smoothness is modeled. The individual tracking error acquired from servo feed systemmodel is converted to the contour error by homogeneous transformation matrix and Frenet frame, and abnormal tool marks in flank millingare suggested. The cutting experiments conform to simulation; the effect of the dynamic indicators of the CNC machine tool is exploredby the abnormal marks on the machined parts. This approach provides a support for designing specimens and investigating machinetool dynamics performance in working accuracy test.

Research on the Power Sharing Control and Stability of VSGs

Xie, Dong,Zang, Da-Jin,Gao, Peng,Wang, Jun-Jia The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Aiming at the deficiencies of power sharing control performances when a traditional droop control is adopted for microgrid inverters, this paper proposes a microgrid inverter power sharing control strategy based on a virtual synchronous generator. This control method simulates the electromechanical transient characteristics of a synchronous generator in a power system by an ontology algorithm and the control laws of a synchronous generator by control over the speed governor and excitation regulator. As a result, that the microgrid system is able to effectively retain the stability of the voltage and frequency, and the power sharing precision of the microgrid inverter is improved. Based on an analysis of stability of a microgrid system controlled by a virtual synchronous generator, design thoughts are provided for further improvement of the power sharing precision of inverters. The simulation results shows that when the virtual synchronous generator based control strategy was adopted, the power sharing performances of microgrid inverters are improved more obviously than those using the droop control strategy.

Isomeric Folate-Conjugated Polymeric Micelles Bind to Folate Receptors and Display Anticancer Effects

Dong, Qing,Xie, Zuo-Xu,Xie, Cao,Lu, Wei-Yue,Zhang, Qian,Li, Xue,Liu, Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

The present study aimed to prepare and evaluate polymeric micelles conjugated with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups for antitumor efficacy. The isomeric block copolymers, ${\alpha}$- and ${\gamma}$-folate-polyethyleneglycol-distearoyl phosphatidylethanolamine (${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE), were produced by solid phase peptide synthesis. Three types of doxorubicin (DOX)-loaded polymeric micelles (MPEG-DSPE-DOX and ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPEDOX micelles) were prepared via the film formation method. Compared with MPEG-DSPE-DOX micelles, the ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPE-DOX micelles presented a higher cellular uptake behavior in the live cell study. Cell viability percentages were 81.8%, 57.3%, 56.6% at 2 hours for MPEG-DSPE-DOX, ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles, respectively (p<0.05). Using the KB xenograft tumor model, both ${\alpha}$- and ${\gamma}$-folate-conjugated micelles were found to have better antitumor effects with lower toxicity in comparison with MPEG-DSPE-DOX micelles. No difference in in vivo antitumor efficacy was found between ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles. The folate-conjugated micelles might be a potentially useful strategy for tumor targeting of therapeutic agents, whether grafting with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups.

Orthogonal 방법을 통한 Poly(AM-DMDAAC)/MMT 고흡수성나노복합체 제조 연구

Jun Dong Yuan,Ming Zhou,Shuang Qiao Yang,Yong Guo Zhou,Nan Qin,Song Tao He,Dong Lai,Zhong Qiang Xie 한국고분자학회 2014 폴리머 Vol.38 No.1

A novel poly(AM-DMDAAC)/MMT superabsorbent nanocomposites are prepared by radical polymerizationusing ammonium persulfate (APS) and anhydrous sodium sulfite as a free radical initiator and N,N-methylene bisacrylamide(MBA) as a crosslinker. In this paper, an optimization study on the synthesis of superabsorbent nanocompositesis carried out. Orthogonal array experiment indicates that the optimized conditions is acrylamide (AM) content 23 wt%,diallyl dimethyl ammonium chloride (DMDAAAC) content 6 wt%, montmorillonite (MMT) content 4 wt%, initiatorcontent 0.2 wt% and crosslinker content 0.02 wt%. Under the optimization syntheses conditions concluded, the maximumwater absorbency in distilled water is 659.53 g·g-1 and in 2 wt% sodium chloride solution is 116.25 g·g-1. Compared withthe range values of different factors (Rj), the order of significance factors in distilled water is C (MMT) > B (DMDAAC)> A (AM) > D (crosslinker) > E (initiator). MMT is intercalated during polymerization reaction and a nanocompositestructure is formed as shown by TEM analysis and XRD analysis.

A New C-10 Acetylene and A New Triterpenoid from Conyza canadensis

Wei Dong Xie,Xue Gao,Zhong Jian Jia 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.5

From the whole plants of Conyza canadensis (Compositae), a new C-10 acetylene, namely 8R, 9R-dihydroxymatricarine methyl ester (1), and a new triterpenoid, namely 3β, 16β, 20β–trihydroxytaraxast- 3-O-palmitoxyl ester (4), were isolated along with eleven known compounds (2, 3, 5-13). The structures of all 13 compounds were elucidated on the basis of their spectral data. The antibacterial activities of compounds 1-3 were evaluated.

A Systematic Review of Studies on Cyber Physical System Security

Peiyuan Dong,Yue Han,Xiaobo Guo,Feng Xie 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Cyber-Physical System (CPS) is a system of systems which integrates physical system with cyber capability in order to improve the physical performance [1]. So far, it is being widely applied in areas closely related to national economy and people’s daily lives. Therefore, CPS security problems have drawn a global attention and an appropriate risk assessment for CPS is in urgent need. According to the researches and discussions in recent years, we believe that most researchers have already established a comprehensive understanding about CPS. This paper systematically introduced CPS’s conception, development and applications assisted. In addition, concerning about its aspects of safety and security, we also analyzed CPS’s risks and new requirements as an up-to-date technique brings. We elaborate the existing work and propose a research focus that has not been paid enough attention to, and proposed a security framework for CPS. At last, after providing a classic modeling and simulation method of CPS, we bring forward a new idea for accessing the experimental results into existing systems.