Sphingobacterium bambusae sp. nov., Isolated from Soil of Bamboo Plantation

Shengwen Duan,Zhengchu Liu,Xiangyuan Feng,Ke Zheng,Lifeng Cheng 한국미생물학회 2009 The journal of microbiology Vol.47 No.6

A Gram-negative, non-motile, non-spore-forming bacterial strain designated IBFC2009T was isolated from soil of a bamboo plantation. The strain could grow at 11°C~39°C, pH 6.0~9.0, and in the presence of 0~5% NaCl. Based on 16S rRNA gene sequence analysis, Strain IBFC2009T belonged to the genus Sphingobacterium and showed the highest sequence similarity of 94.6% (S. composti T5-12T) with the type strains within the genus. The major fatty acids were summed feature 3 (iso-C15:0 2-OH and/or C16:1 ω7c, 34.4%), iso-C15:0 (22.4%), C16:0 3-OH (15.2%), and iso-C17:0 3-OH (12.8%). The G+C content of the genomic DNA was 41.0 mol%. According to the phenotypic and genotypic characteristics, Strain IBFC2009T should represent a novel species of the genus Sphingobacterium, for which the name Sphingobacterium bambusae sp. nov. is proposed. The type strain is IBFC2009T (=CCTCC AB 209162T =KCTC 22814T).

Classification of Rock Mass Structure and Its Scale Effect

( Shengwen Qi ),( Songfeng Guo ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

As known that many kinds of rock mass classification systems have been presented to classify the rock mass quality, e.g., RMR system, Q system, GSI system. However, only a few of references consider the effect of rock mass structure in the rock mass classification. It is always a difficult task to describe rock mass structure quantitatively. In this paper, a classification scheme for rock mass structure was presented based on Gu et al. (1979) after a thoroughly review. The classification considered the lithology, petrography as well as tectonics; meanwhile the attitude of the bedding plane is stressed in the classification, as a significant indicator for experienced tectonic intensity and also the rock mass stability. The classification divided the rock mass structures into five main types, i.e. magmatite or orthometamorphite structure, sedimentary or parametamorphite structure, tectonite structure, decomposed rock structure and loose structure. Each type contains some subtypes which are depicted in both a qualitative and quantitative way to ease the application. The scale effect of rock mass classification is then discussed considering the size of rock matrixes and discontinuities. The mechanical behaviors of each rock mass structure type are investigated with a number of field cases.

In situ monitoring of pore structure of magnesium oxysulfate cement paste: Effect of MgSO4/H2O ratio

Shengwen Tang,Changrong Wei,Rongjin Cai,Jiasheng Huang,E. Chen,Junhui Yuan 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

This work systematically presented the pore structure evolution of different magnesium oxysulfate(MOS) cement pastes by non-contact impedance measurement (NCIM), fractal theory and othermicrostructural experiments. According to the evolution of electrical impedance response, threehydration stages (dissolution, acceleration and hardened stages) can be identified in the pastes. Furthermore, based on the results obtained from NCIM and fractal theory, the porosity, incremental porevolume, pore tortuosity, average pore diameter and maximal pore diameter of MOS cement pastes areinvestigated. The influence of MgSO4/H2O ratio on pore structure of MOS cement paste is primarilyexplained. It can be inferred from predicted and experimental results that NCIM is a good method toanalyze the microstructure evolution of MOS cement pastes in-situ.

Resilient Routing Overlay Network Construction with Super-Relay Nodes

( Shengwen Tian ),( Jianxin Liao ),( Tonghong Li ),( Jingyu Wang ),( Guanghai Cui ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.4

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. The key to overlay routing is the placement and maintenance of the overlay infrastructure, especially, the selection and placement of key relay nodes. Spurred by the observation that a few relay nodes with high betweenness centrality can provide more optimal routes for a large number of node pairs, we propose a resilient routing overlay network construction method by introducing Super-Relay nodes. In detail, we present the K-Minimum Spanning Tree with Super-Relay nodes algorithm (SR-KMST), in which we focus on the selection and connection of Super-Relay nodes to optimize the routing quality in a resilient and scalable manner. For the simultaneous path failures between the default physical path and the overlay backup path, we also address the selection of recovery path. The objective is to select a proper one-hop recovery path with minimum cost in path probing and measurement. Simulations based on a real ISP network and a synthetic Internet topology show that our approach can provide high-quality overlay routing service, while achieving good robustness.

Local optimization of thruster configuration based on a synthesized positioning capability criterion

Shengwen Xu,Lei Wang,Xuefeng Wang 대한조선학회 2015 International Journal of Naval Architecture and Oc Vol.7 No.6

DPCap analysis can assist in determining the maximum environmental forces the DP system can counteract for a given heading. DPCap analysis results are highly affected by the thrust forces provided by the thrust system which consists of several kinds of thrusters. The thrust forces and moment are determined by the maximum thrust of the thrusters as well as the thruster configuration. In this paper, a novel local optimization of thruster configuration based on a synthesized positioning capability criterion is proposed. The combination of the discrete locations of the thrusters forms the thruster configuration and is the input, and the synthesized positioning capability is the output. The quantified synthesized positioning capability of the corresponding thruster configuration can be generated as the output. The optimal thruster configuration is the one which makes the vessel has the best positioning capability. A software program was developed based on the present study. A local optimization of thruster configuration for a supply vessel was performed to demonstrate the effectiveness and efficiency of the program. Even though the program cannot find the global optimal thruster configuration, its high efficiency makes it essentially practical in an engineering point. It may be used as a marine research tool and give guidance to the designer of the thrust system.

Model predictive current control method for PMSM drives based on an improved prediction model

Fan, Shengwen,Tong, Chaonan The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

In motor drive systems based on model predictive control, a mathematic model of the motor is used to predict the future behavior of the system. However, the parameters in the motor model may not match their real values since these parameters may vary under different operation conditions. All parameter variations result in inaccurate predictions, and influence the steady-state control performance of the whole control system. In this paper, an improved model predictive control method is presented. Firstly, when parameter mismatches exist, the sources of the current prediction error are analyzed. It is revealed that current prediction error is directly affected by a prediction model with parameter mismatches and inaccurate one-step delay compensation. In particular, the influence form one-step delay compensation is discussed in this paper. Then a reaching-law-based sliding mode discrete observer is introduced to implement accurate one-step delay compensation and to observe all parameter variations. Finally, a predictive control method combined with sliding-mode discrete observation is presented to reduce parameter sensitivity. Simulation and experimental results show that the proposed method can increase the robustness of model predictive control systems.

Local optimization of thruster configuration based on a synthesized positioning capability criterion

Xu, Shengwen,Wang, Lei,Wang, Xuefeng The Society of Naval Architects of Korea 2015 International Journal of Naval Architecture and Oc Vol.7 No.6

DPCap analysis can assist in determining the maximum environmental forces the DP system can counteract for a given heading. DPCap analysis results are highly affected by the thrust forces provided by the thrust system which consists of several kinds of thrusters. The thrust forces and moment are determined by the maximum thrust of the thrusters as well as the thruster configuration. In this paper, a novel local optimization of thruster configuration based on a synthesized positioning capability criterion is proposed. The combination of the discrete locations of the thrusters forms the thruster configuration and is the input, and the synthesized positioning capability is the output. The quantified synthesized positioning capability of the corresponding thruster configuration can be generated as the output. The optimal thruster configuration is the one which makes the vessel has the best positioning capability. A software program was developed based on the present study. A local optimization of thruster configuration for a supply vessel was performed to demonstrate the effectiveness and efficiency of the program. Even though the program cannot find the global optimal thruster configuration, its high efficiency makes it essentially practical in an engineering point. It may be used as a marine research tool and give guidance to the designer of the thrust system.

Molecular simulation investigations on the coating of Al-alloy surface by nano-SiO2-epoxy composite

Wang Shengwen,Qiu Yinxiang 한국물리학회 2022 Current Applied Physics Vol.39 No.-

To improve corrosion protections, a better understanding of the coating behavior and therefore the interaction properties between the inhibitor and the surface is a vital factor. Density functional theory (DFT) simulations were used to explore the adsorption properties of the pure epoxy and nano-SiO2-epoxy composites on the Al2Cu surface. The interaction energies and transferred charges of adsorbed composites on the Al2Cu surface and their optimized structures with various interacting orientations are investigated. It is found that nano-SiO2-epoxy adsorb more strongly on Al2Cu substrate in comparison with the epoxy matrix with interaction energies of -228.084 kcal/mol and -35.341 kcal/mol, respectively. The validity of our computational methods was evaluated by experiments as well as high-level quantum chemistry method. The atom-in-molecules analysis with DFT indicates that the interaction nature is typical for electrostatics. The stability of the adsorption behavior of composites on the surface was also explored by DFT-based molecular dynamics simulation.

Load-Balanced One-hop Overlay Multipath Routing with Path Diversity

( Jianxin Liao ),( Shengwen Tian ),( Jingyu Wang ),( Tonghong Li ),( Qi Qi ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.2

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. For one-hop overlay source routing, when a given primary path suffers from the link failure or performance degradation, the source can reroute the traffic to the destination via a strategically placed relay node. However, the over-heavy traffic passing through the same relay node may cause frequent package loss and delay jitter, which can degrade the throughput and utilization of the network. To overcome this problem, we propose a Load-Balanced One-hop Overlay Multipath Routing algorithm (LB-OOMR), in which the traffic is first split at the source edge nodes and then transmitted along multiple one-hop overlay paths. In order to determine an optimal split ratio for the traffic, we formulate the problem as a linear programming (LP) formulation, whose goal is to minimize the worse-case network congestion ratio. Since it is difficult to solve this LP problem in practical time, a heuristic algorithm is introduced to select the relay nodes for constructing the disjoint one-hop overlay paths, which greatly reduces the computational complexity of the LP algorithm. Simulations based on a real ISP network and a synthetic Internet topology show that our proposed algorithm can reduce the network congestion ratio dramatically, and achieve high-quality overlay routing service.

Study on the Relationship Between Earthquake-induced Landslide Distribution and Topography in Wenchuan Earthquake

( Xianglong Yao ),( Shengwen Qi ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The existing research proves that, unlike rainfall-induced landslides, earthquake landslides occur mostly in the high position of the slope, and the development of earthquake landslides has an obvious relationship with the topography. A large number of landslides induced in the Wenchuan earthquake also showed a similar relationship. The landslides occurred in the near fault area were large in density and large in scale, while the landslides in the areas far from the faults occurred mostly at the heights of the slopes and the landslide development density and scale were relatively reduced small. In this paper, five strip-shaped areas extending to the upper disc of the fault were selected in the upper seismic fault (central fault) of the Wenchuan earthquake, and the landslide boundary (without the accumulation area) was carefully interpreted. The object of research is to study the relationship between earthquake landslide and terrain. The study found that the scale of the earthquake landslide is mainly controlled by the fault distance and terrain.