Advanced Materials Research Vols. 121-122

Abstract: In this paper we mainly discuss the Collaborative Filtering algorithm which is widely applied in E-commerce. This article presents the idea of Collaborative Filtering algorithm and its main step. It analyzes the problem of cold start and data sparsity which affect the accuracy of prediction and results, as well as an idea of improvement Collaborative Filtering algorithm.

Abstract: Currently, LBS (Location-based Services) as a new emerging business which is based on mobile communication network is becoming more and more popular. However domestic industry is lack of perfect location service platform and standards because of the complexity and large scale of LBS. Aimed at the cases, the architecture of mobile location service (MLS) platform based on OpenLS (OpenGIS® Location Services) standards is constructed in the paper, and makes it accord with the international standard. Moreover GIS (Geographic Information System) middleware model is also proposed in the paper. We encapsulate the secondary location algorithm and path navigation algorithm into GIS middleware and present four standard interfaces, which could support distributed management and improves the portability of the platform.

Abstract: This paper compared relevant kinematic parameters of the long jump elites from home and abroad, it analysed the reason why the reduction of the horizontal velocity in the last two steps in the world elites was 0.48m/s, while 0.68m/s in the domestic elites.The first reason the paper presented is to jump up too early which leads to the decrease of the velocity in the last two steps, the second reason is that the accelerative ability is weak and the length of one step varies, and the third reason is that the landing angle of the last step is small but it is big for the angle of departure. Apart from the above mentioned reasons, the paper also proposed another indispensible factor is that, the change of the knee angle in the last two steps which can help prevent the horizontal velocity from deceasing.

Abstract: HSE is a system management methodology of reducing and eliminating the possible risks of health, safety and environment in the process of production. This paper analyzed the feature of HSE management system, and discussed on the feasibility and the role of HSE management system applied to construction projects for construction enterprise. Then China’s enterprise status of HSE management was analyzed, the problem for China’s enterprise to implement HSE management system was described, and the development direction for China’s construction enterprise to implement HSE management system was put forward at last.

Abstract: As the characteristics of power line channel varies over time, makes it be different from the tradition networks. In this paper, we study the performance of a form of slotted binary exponential random backoff algorithm using in HomePlug protocol. The performance of the backoff algorithm is evaluated by simulation. The results show that it makes the network performance become worse with the expansion of network.

Abstract: A phase shift signal generator which has high precision and whose phase can be easily and digitally controlled is designed through utilizing DDS technology. A method which can replace complicated hardware description language programming through calling modules and setting parameters is proposed. The designed phase shift signal generator passes waveform simulation under Simulink and SignalTap Ⅱcertification, and the results obtained on the FPGA board are correct. The DSP Builder is utilized to design the phase shift signal generator, which reduces the difficulty of the design and shortens the design time.

Abstract: In this paper, unscented Kalman filter (UKF) is studied to estimate the state of Dead reckoning (DR) and GPS integrated navigation system. The positioning error of DR system mainly comes from two factors, the azimuth error and odometer scale factor error. Conventional model of DR/GPS integrated navigation chooses acceleration, position and velocity as observation states, and azimuth error is not estimated, which is one of the key error sources. A new error model of DR/GPS system is adopted that includes azimuth error as a state, which makes it possible to estimate both of the two major error sources. UKF directly approximates the probability density distribution of random variable and avoids the linearization of nonlinear function, which improves the filtering precision. UKF is used to implement an improved DR/GPS system. Road test has been conducted to prove the effectiveness of the scheme.

Abstract: The development of photovoltaic industry can produce great socio-economic implications in terms of induced production and job creation. The world photovoltaic market has been growing and will be strongly influenced by photovoltaic costs and available technologies.. The overall cost to implement a facility for module production having a capacity per year that may be regarded as the minimum profitable size for module production in China is considered. An input–output analysis is used for assessing the relative economic impact on production and employment. A sensitivity analysis shows that the results are reasonably robust.

Abstract: GIS attribute data is the property of GIS entity, it has fuzziness and uncertainty. The binary relation for GIS entity object and attribute is meet to the property for approximate space. We choose the object and attribute of GIS information system in our study, use lattice concept, and we think the GIS entities can form partial order relation, and lattice(P(A), ) can form one complete partial order lattice. GIS entities can form hierarchical approximate space in subsection space relation, and the knowledge granularities are thining along with the increasing of attribution.

Abstract: Short-term adverse weather conditions have a direct impact on geological disasters. However, the data source of high-precision weather on real time can be provided by GPS technology. At the same time, the high-precision and real-time weather forecast can provide important and basic information for geological disasters monitoring, forecasting and prevention. However, the precision of the total zenith delay in troposphere directly affects the estimating precision of the water vapor contents over stations, which affects the accuracy of real-time weather forecast. In this paper, the total zenith delay of GPS observational station is solved respectively by GPS data on GPS observational station grouped with different IGS stations using high-precision software-GAMIT/GLOBK developed by the Massachusetts Institute of Technology. The solving results are comparatively analyzed to draw：the best number of IGS tracking stations by grouping network for improving the precision of the total zenith delay in troposphere is 3. It is of great realizable significance.