Static Bending Creep Properties of Glass Fiber Surface Composite Wood

To study the static bending creep properties of glass fiber reinforced wood,glass fiber reinforced poplar(GFRP)specimens were obtained by pasting glass fiber on the upper and lower surfaces of Poplar(Populus euramevicana,P),the performance of Normal Creep(NC)and Mechanical Sorptive Creep(MSC)of GFRP and their influencing factors were tested and analyzed.The test results and analysis show that:(1)The MOE and MOR of Poplar were increased by 17.06%and 10.00%respectively by the glass fiber surface reinforced composite.(2)The surface reinforced P with glass fiber cloth only exhibits the NC pattern of wood and loses the MSC characteristics of wood,regardless of the constant or alternating changes in relative humidity.(3)The instantaneous elastic deformation,viscoelastic deformation,viscous deformation and total creep deflection of GFRP are positively correlated with the stress level of the external load applied to the specimen.Still,the specimen’s creep recovery rate is negatively correlated with the stress level of the external load applied to the specimen.The static creep deflection and viscous deformation of GFRP increase with the increase of the relative humidity of the environment.(4)The MSC maximum creep deflection of GFRP increased by only 7.41%over the NC maximum creep deflection,but the MSC maximum creep deflection of P increased by 199.25%over the NC maximum creep deflection.(5)The Burgers 4-factor model and the Weibull distribution equation can fit the NC and NC recovery processes of GFRP well.

Fast frequency response of inverter-based resources and its impact on system frequency characteristics

The inertia response and primary frequency regulation capability of synchronous grids are declining owing to the increasing penetration of inverter-based resources. The fast frequency response(FFR) of inverter-based resources is an important mitigation option for maintaining grid security under the conditions of low inertia and insufficient primary frequency response capability. However, the understanding and technical characteristics of the FFR of inverter-based resources are still unclear. Aiming at solving the aforementioned problems, this paper proposes a definition for FFR based on the impact mechanism of FFR on system frequency. The performance requirements of FFR are clarified. Then, the effects of FFR on system frequency characteristics are further analyzed based on steady-state frequency deviation, the initial rate of change of frequency, and the maximum transient frequency deviation. Finally, the system requirements for FFR and its application effects are verified by simulating an actual bulk power grid, providing technical support for subsequent engineering application.

Optimization Algorithm for Reduction the Size of Dixon Resultant Matrix:A Case Study on Mechanical Application

In the process of eliminating variables in a symbolic polynomial system,the extraneous factors are referred to the unwanted parameters of resulting polynomial.This paper aims at reducing the number of these factors via optimizing the size of Dixon matrix.An optimal configuration of Dixon matrix would lead to the enhancement of the process of computing the resultant which uses for solving polynomial systems.To do so,an optimization algorithm along with a number of new polynomials is introduced to replace the polynomials and implement a complexity analysis.Moreover,the monomial multipliers are optimally positioned to multiply each of the polynomials.Furthermore,through practical implementation and considering standard and mechanical examples the efficiency of the method is evaluated.

RSSI Enhanced Microkernel-Based LBS Design

Geographical Information System (GIS) always plays an integral role in LBS systems. But it comes with technology problems, such as less flexible, low efficiency, no redundancy of existing geographic information of application configuration which has high entry cost. At same time, indoors positioning is attracting more and more attention from research domain where GPS-like systems do not work. By RSSI location fingerprint data that sampling from the actual WSN environment, this article analyzed RF signal propagation characteristics in indoor from the point of view of the indoor positioning, and analyzed some factors that may affect the positioning error, which provided a theoretical basis for the positioning algorithm design and positioning system deployment. The aim of this paper is also to present a lightweight, efficient and scalable microkernel plug-in geospatial information application system and its implementation method for GIS in LBS design and practice. In this paper a software model called Resource loading manager (RLM) is designed. Through the RLM efficient allocation of geographic information resources and security management could be achieved.

Cloud-Based Spatial Information Service Architecture within LBS

Location Based Services (LBS) have become a popular technology to retrieve information about the surroundings of a mobile user which results in ubiquitous demand of spatial information service with diverse needs of different types of users. The aim of this paper is to reveal the potential of cloud-based spatial information service architecture that plays an integral role in LBS design and practice. This paper analyzes the characteristics of the spatial information of cloud services, such as data access transparency, spatial analysis parallelization, service capabilities flexible, information services standardization, service aggregation visualization, re-development flexible. This paper provides a possible solution to overcome the LBS service issues. In this paper, the short review of LBS and Cloud computing are given first and then the possibility of LBS design with cloud computing are analyzed. At last, cloud-based spatial information service architecture is proposed.

Microkernel and Middle-Ware Based GIS Platform Design

By contrasting the traditional way in which GIS was completed that comes with less flexible, low efficiency, and lack redundancy which cause high entry cost, the fast development of microkernel plug-in technology provides the lightweight, efficient and scalable solution to Geographical Information System (GIS). This paper is to reveal the potential of microkernel plug-in geospatial information processing technology in GIS design and practice, with the acceptance and usage of function model called Resource loading manager(RLM) for GIS applications, which provides a possible solution to overcome the GIS’s high cost issue. After the short review of microkernel plug-in technology, the possibility of GIS design with microkernel is analyzed. This paper also introduced the composition of the whole system and the design of GIS service platform based on middle-ware in detail.