Advanced Materials Research Vols. 457-458

Abstract: Many localization algorithms in wireless sensor networks mention possible regions to increase the degree of localization precision. In this paper, we present the definite correlation between the estimation error and the possible region. The estimation error, which is the most important indictor to judge the performance of a localization algorithm, is proportional to the square root of the area of the possible region and the factor of proportionality relates to the shape of the possible region. We also propose two applications of the definite correlation, including estimation errors detection and energy conservation. The simulation results show that the definite correlation is suitable for all kinds of possible regions and it is feasible to detect estimation errors and conserve energy when we fix reasonable areas of possible regions in wireless sensor networks.

Abstract: As the validity period of production data is short and data volume is big, a real-time data base is designed as the system database. Based on WEBGIS technique, Geographical Information System is designed, moreover, the production system, water flood system and power system are integrated into the system, thus laying foundations for production scheduling. Through analyzing real-time information stored in the database, early warning of well production and decision support can be provided for production managers, thus improving management level and promoting the coordinated development of the oilfield.

Abstract: Virtual proving ground (VPG) are used effectively for commercial vehicle system development, human factor study, and other purposes by enabling to reproduce actual driving conditions in a safe and tightly controlled environment. This paper describes a virtual proving ground developed for design and evaluation of commercial vehicle and for driver-vehicle interaction study. VPG consists of a real-time vehicle simulation system, a visual and audio system, a driver handling signals acquisition system providing a realistic interface between the operator and the simulated environment, and 3D proving ground databases with areas suitable for various types of vehicle test tasks. The real-time vehicle simulation system simulates dynamic motion of realistic vehicle models in real-time. The visual system generates high fidelity driving scenes. The handling signals collection system acquires the steering, braking, accelerating, and shifting operation of driver. The pilot experiments carried out in the areas of vehicle handling and stability study are also presented to show the effectiveness of the developed VPG.

Abstract: The insufficiencies of LEACH routing algorithm that the energy dissipation is discordance and cluster head is unevenly-distributed in whole network lead to excessive energy dissipation. Aiming at that, this paper purposes an improvement algorithm named LEACH-CREFM based on zoning network into sub-regions. The new algorithm adopts thresh setting relate to area of sub-region and multiple hop data transition between sub-regions as approach of reducing energy dissipation. The analysis of performance contrast between LEACH and LEACH-CREFM is presented. All conclusions have been confirmed by simulations on ns 2.27.

Abstract: this recommendation algorithm based on User-Item Attribute Rating Matrix (UIARM) can solve the cold-start problem, but the recommended low efficiency, poor quality. The use of Multi-Attribute Rating Matrix (MARM) can solve this problem; it can reduce the computation time and improve the recommendation quality effectively. The user information is analyzed to create their attribute-tables. The user's ratings are mapped to the relevant item attributes and the user's attributes respectively to generate a User Attribute-Item Attribute Rating Matrix. After UAIARM is simplified, MARM will be created. When a new item/user enters into this system, the attributes of new item/user and MARM are matched to find the N users/item with the highest match degrees as the target of the new items or the recommended items. Experiment results validate the cold-start recommendation algorithm based on MARM is efficient.

Abstract: Due to excellent characteristics of lower cost, higher reliability, smaller power consumption, less volume and lighter weight, micro electro mechanical system (MEMS) has been widely accepted and used in portable electronic devices. Based on port S3C2440, a proper method is presented to carry out the study of dynamical characteristic for tri-axial digital accelerometer ADXL345. The results could provide a well approach for improvement of this novel component.

Abstract: Stratospheric airship is capable of station-keeping at high altitude in precondition of the balance of buoyancy and weight and of thrust and drag. Based on computation process, when some initial technology guidelines and conditions are supposed, the size of airship is gained and it is analyzed that certain technology guideline has more or less influence on length and payload of airship. It is concluded from the analyses that envelope mass/area ratio had the largest effect on key elements of airship, such as length and payload etc. Meanwhile, based on some available design parameters of typical traditional-shape airships being in development, the envelope mass/area ratio required for corresponding airships is scheduled for station-keeping at destine altitude and several technology approaches are proposed.

Abstract: A new three-dimensional Monte Carlo (MC) model in presence of pores of microstructure evolution for three-phase nano-composite ceramic tool materials is successfully established to simulate the grain growth during sintering process in this paper. The defect-free microstructure evolution and microstructure evolution in presence of pore are simulated and investigated. The results show that the new MC model can well simulate the grain growth and pores shrinkage during densification process. Compared with defect-free system, the grain growth velocity can be slow down obviously owning to the existence of pores.

Abstract: In this paper, glass wool has been prepared under various rotating speed of centrifugal pan by centrifugal-spinneret-blow process. The fiber diameter of glass wool has been studied by scanning electron microscopy (SEM) and vertical optical microscope (VOM). With the increase of rotating speed from 1800 rpm to 2400 rpm, the mean fiber diameter decreased from 5.9 µm to 3.9 µm, indicating the distribution of glass wool becomes more uniformity. The results show that the rotating speed has a direct and pronounced effect on the fiber diameter and distribution. The higher the rotating speed is, the smaller the mean fiber diameter is, and the more uniformity the distribution of fiber diameter is.

Abstract: With the development of embedded system, the implementation of application based on Qt and embedded Linux is an emphasis in researching the embedded GUI system. This paper introduces the cross compiling process and Qt/Embedded, and then describes how to develop the applications on Qt/Embedded. The methods in this paper have been validated on this developing platform(QQ2440V3)．