ASESDP : An Efficient Service Discovery Protocol in Pervasive Computing Environments

Ma, Qianli,Liao, Minghong,Jiang, Shouxu,Hong, Wan-Pyo,Gao, Zhenguo The Korea Institute of Information and Commucation 2008 Journal of information and communication convergen Vol.6 No.4

Service discovery is the technology of finding needed services in networks, and a key point in pervasive computing environments. This paper presents a novel service discovery protocol: ASESDP(AIP and SRR Enhanced Service Discovery Protocol). In ASESDP, tow schemes are proposed to enhance its performance: AIP(Advertisement Information Piggybacked) and SRR(Shortest Reply Route). In AIP, parts of advertisement information are piggybacked in the service reply packet, which makes the advertisement information propagating along the reply path, and spreads its transmission area. In SRR, in order to reduce the service response time, the shortest reply route is chosen to forward the service reply packet to the source node sending the service request. With the theoretical analysis and Glomosim simulation results, it is verified that ASESDP can reduce the number of service request packets, save the response time, and improve the efficiency of service discovery.

H<SUB>∞</SUB> finite-time stability for discrete-time singular linear time-varying systems

Qian Ma,Yuangong Sun 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

This paper deals with H∞ finite-time stability for a class of discrete-time singular linear time-varying systems. Sufficient conditions have been established such that the system is regular, causal and H∞ finite-time stable, which are expressed in linear matrix inequalities and can be determined by using LMI Control Toolbox in Matlab. Finally, a numerical example is given to illustrate the effectiveness of the result.

The Analysis and Comparison of the Needle-puncture Property of Four Types of Silkworm Cocoons

Qian Wang,Yan Zhang,Hao Chen,Rong Zhang,Xuhong Yang,Ping Wang,Pibo Ma 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

Silkworm cocoons display outstanding properties in many aspects, such as thermal protection, biocompatibilityand mechanical resistance and so on. In this paper, we focus on the puncture properties without detailed exploration of fourtypes of cocoons (three domesticated cocoon and Eri silkworm). Different sections, end and middle, as well as differentdirections, puncturing from inner and outer surface, of four types of aforementioned cocoons were systematically analyzedand compared. The results of present research show that the middle section exhibits a relatively greater needle-punctureresistance compare with end section for three B. mori silkworm cocoons. With regard to different puncture directions, fromexternal and internal surface, puncturing from internal surface exhibits a relatively higher needle-puncture load as well asfracture displacement tendencies compared with needle-puncture performance from external surface no matter in middle orend sections. Combining physical parameter assessment, statistical analysis and needle-puncture performance, this researchinspires a clear-cut frame to design a composite with high puncture resistance.

New Explicit Criteria for Finite-time Stability of Singular Linear Systems Using Time-dependent Lyapunov Functions

Qian Ma,Yuangong Sun 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.4

In this paper, the finite time stability and H∞ finite-time stability of singular linear systems are considered. By constructing a class of time-dependent Lyapunov functions and introducing a zero term with free weighting matrices, we first establish a new explicit criterion in the form of LMIs for finite-time stability of the system. Then, an H∞ finite-time stability criterion for the system is obtained. The given results are easily verifiable and less conservative compared with some existing ones in the literature. Finally, four numerical examples are given to demonstrate the effectiveness of the proposed method.

Numerical simulation of wave slamming on wedges and ship sections during water entry

Ma, Zhihua,Qian, Ling Techno-Press 2018 Ocean systems engineering Vol.8 No.2

The open source software OpenFOAM is utilised to simulate the water entry and hydrodynamic impact process of 2D wedges and ship hull sections. Incompressible multiphase flow solver interDyMFoam is employed to calculate the free fall of structure from air into water using dynamically deforming mesh technique. Both vertical and oblique entry of wedges of various dead-rise angles have been examined. A convergence study of dynamics as well as kinematics of the flow problem is carried out on successively refined meshes. Obtained results are presented and compared to the experimental measurements showing good agreement and reasonable mesh convergence of the solution.

Facile synthesis of flower-like α-Fe2O3/ZnFe2O4 architectures with self-assembled core-shell nanorods for superior TEA detection

Ma Qian,Li Hui,Liu Yu,Liu Mingle,Fu Xinghua,Chu Shushu,Li Hang,Guo Jia 한국물리학회 2021 Current Applied Physics Vol.21 No.-

Uniform flower-like α-Fe2O3 architectures with self-assembled core-shell nanorods are constructed and successfully prepared via the facile process. The concentration of Fe salt plays a great significance for morphological evolution from nanorods to self-assembled microflowers. Flower-like α-Fe2O3/ZnFe2O4 consisting of α-Fe2O3 core and ZnFe2O4 shell nanorods are derived from FeOOH/ZIF-8 precursors. The detailed studies reveal that the tunable growth of ZIF-8 nanoparticles on three-dimensional FeOOH microflowers at room temperature and the availble calcination regulation are responsible for the formation of core-shell Fe2O3/ZnFe2O4 composites. The highest response value of flower-like α-Fe2O3/ZnFe2O4 architectures to 100 ppm triethylamine (TEA) has been improved to 141 at 280 ◦C, which is calculated to be 6.2 times compared with flower-like α-Fe2O3 architectures (22.7). The enhanced gas-sensing mechanism of α-Fe2O3/ZnFe2O4 composites can be attributed to the typical microflowers structures, the large specific surface area, the effective heterojunctions between α-Fe2O3 core and ZnFe2O4 shell, and the improved electron transfer process.

The effect of HCP on the formation of twin boundaries and dislocations in Ni–Co alloys

Ma Rui-bo,Zhou Li-li,Liang Yong-chao,Chen Qian,Tian Ze-an,Liu Rang-su,Mo Yun-fei,Gao Ting-hong,Xie Quan 한국물리학회 2021 Current Applied Physics Vol.29 No.-

In this study, molecular dynamics (MD) was used to simulate the rapid solidification process of Ni47Co53 and Ni48Co52 alloys at a cooling rate of 1012 K/s. The effects of HCP on the formation of twin boundaries and dislocations in two Ni–Co alloys are studied. It is found that the difference of HCP clusters is the main effect that producing discrepancies on microstructure of two alloys. The number of HCP clusters accounted for 9.23% in Ni47Co53 alloy. They are regularly arranged to form the number of single-layer twin boundaries, and each twin boundary ends in a dislocation. The FCC and HCP structures coexist in the same atomic layers, which is easy to create dislocations. The relatively standard FCC crystal and only 0.32% HCP clusters are formed in Ni48Co52 alloy at 300 K. That small amount of HCP clusters are dispersed on the surface, and cause the formation of dislocation in the border with FCC clusters.

Transcriptome profiling and identification of functional genes involved in H2S response in grapevine tissue cultured plantlets

Qian Ma,Jingli Yang 한국유전학회 2018 Genes & Genomics Vol.40 No.12

Hydrogen sulfide ( H2S), a small bioactive gas, has been proved functioning in plant growth and development as well as alleviation of abiotic stresses, which including promoting seed germination, accelerating embryonic root growth, regulating flower senescence, inducing stomatal closure, and defending drought, heat, heavy metals and osmotic stresses etc. However, the molecular functioning mechanism of H2S was still unclear. The primary objective of this research was to analyze the transcriptional differences and functional genes involved in the H2S responses. In details, 4-week-old plantlets in tissue culture of grapevine (Vitis vinifera L.) cultivar ‘Zuoyouhong’ were sprayed with 0.1 mM NaHS for 12 h, and then transcriptome sequencing and qRT-PCR analysis were used to study the transcriptional differences and functional genes involved in the H2S responses. Our results indicated that 650 genes were differentially expressed after H2S treatment, in which 224 genes were up-regulated and 426 genes were down-regulated. The GO enrichment analysis and KEGG enrichment analysis results indicated that the up-regulated genes after H2S treatment focused on carbon metabolism, biosynthesis of amino acids, and glycolysis/gluconeogenesis, and the down-regulated genes were mainly in metabolic pathways, biosynthesis of secondary metabolites, and plant hormone signal transduction. Analyzing the transcription factor coding genes in details, it was indicated that 10 AP2/EREBPs, 5 NACs, 3 WRKYs, 3 MYBs, and 2 bHLHs etc. transcription factor coding genes were up-regulated, while 4 MYBs, 3 OFPs, 3 bHLHs, 2 AP2/EREBPs, 2 HBs etc. transcription factor coding genes were down-regulated. Taken together, H2S increased the productions in secondary metabolites and a variety of defensive compounds to improve plant development and abiotic resistance, and extend fruits postharvest shelf life by regulating the expression of AP2/EREBPs, WRKYs, MYBs, CABs, GRIP22, FERRITINs, TPSs, UGTs, and GHs etc.

Novel reassortant 2.3.4.4B H5N6 highly pathogenic avian influenza viruses circulating among wild, domestic birds in Xinjiang, Northwest China

Qian Zhang,Xindi Mei,Cheng Zhang,Juan Li,Nana Chang,Dilihuma Aji,Weifeng Shi,Yuhai Bi,Zhenghai Ma 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.4

Background: The H5 avian influenza viruses (AIVs) of clade 2.3.4.4 circulate in wild and domestic birds worldwide. In 2017, nine strains of H5N6 AIVs were isolated from aquatic poultry in Xinjiang, Northwest China. Objectives: This study aimed to analyze the origin, reassortment, and mutations of the AIV isolates. Methods: AIVs were isolated from oropharyngeal and cloacal swabs of poultry. Identification was accomplished by inoculating isolates into embryonated chicken eggs and performing hemagglutination tests and reverse transcription polymerase chain reaction (RT-PCR). The viral genomes were amplified with RT-PCR and then sequenced. The sequence alignment, phylogenetic, and molecular characteristic analyses were performed by using bioinformatic software. Results: Nine isolates originated from the same ancestor. The viral HA gene belonged to clade 2.3.4.4B, while the NA gene had a close phylogenetic relationship with the 2.3.4.4C H5N6 highly pathogenic avian influenza viruses (HPAIVs) isolated from shoveler ducks in Ningxia in 2015. The NP gene was grouped into an independent subcluster within the 2.3.4.4B H5N8 AIVs, and the remaining six genes all had close phylogenetic relationships with the 2.3.4.4B H5N8 HPAIVs isolated from the wild birds in China, Egypt, Uganda, Cameroon, and India in 2016–2017, Multiple basic amino acid residues associated with HPAIVs were located adjacent to the cleavage site of the HA protein. The nine isolates comprised reassortant 2.3.4.4B HPAIVs originating from 2.3.4.4B H5N8 and 2.3.4.4C H5N6 viruses in wild birds. Conclusions: These results suggest that the Northern Tianshan Mountain wetlands in Xinjiang may have a key role in AIVs disseminating from Central China to the Eurasian continent and East African.

Secondary Voltage Control for Reactive Power Sharing in an Islanded Microgrid

Qian Guo,Hongyan Wu,Liaoyuan Lin,Zhihong Bai,Hao Ma 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Owing to mismatched feeder impedances in an islanded microgrid, the conventional droop control method typically results in errors in reactive power sharing among distributed generation (DG) units. In this study, an improved droop control strategy based on secondary voltage control is proposed to enhance the reactive power sharing accuracy in an islanded microgrid. In a DG local controller, an integral term is introduced into the voltage droop function, in which the voltage compensation signal from the secondary voltage control is utilized as the common reactive power reference for each DG unit. Therefore, accurate reactive power sharing can be realized without any power information exchange among DG units or between DG units and the central controller. Meanwhile, the voltage deviation in the microgrid common bus is removed. Communication in the proposed strategy is simple to implement because the information of the voltage compensation signal is broadcasted from the central controller to each DG unit. The reactive power sharing accuracy is also not sensitive to time-delay mismatch in the communication channels. Simulation and experimental results are provided to validate the effectiveness of the proposed method.