Advanced Materials Research Vols. 403-408

Abstract: The research uses the finite element software ANSYS to analyze the stress of the standard artificial knee joint, particularly the contact stress between the femoral condyle and the ultra-high molecular weight polyethylene (UHMWPE) meniscus. When analyze the stress of the standard artificial knee joint in the case that knee joint unbend (bend 0°) and bend 10°and 20°, the lower surface of the proximal tibia maintains completely constraints and we apply the corresponding constraints and surface load with the actual situation.Finally calculate the stress distribution of the artificial knee joint. The analysis results were compared with the stress of the normal knee joint to further improve the design of the artificial knee joint.

Abstract: Based on the instantaneous reactive power theory, an improving detection method of harmonic current is put forward. In this method, the harmonic current is detected by current average. The method has the characteristics of simple structure, strong real-time and good dynamic response. In the paper, the proposed method is used to carry out simulation of MATLAB and the results show the effectiveness of the method.

Abstract: Most practical communication systems need higher bandwidth efficiency; this article increased the bandwidth efficiency through code rate and modulation mode, by combining Non-binary LDPC code with MSK modulation and making practical use of them in communication systems. The simulation result showed that the combination of Non-binary LDPC code and MSK modulation possessed not only a stronger error correcting capability but also a higher bandwidth efficiency, which will probably be more applicable in practical communication systems.

Abstract: Automatic modulation classification plays a significant role in intelligent communication. A new method based on feature extraction is proposed for the recognition of M-ary Phase Shift Keying (MPSK) signals. As features, fourth and eighth order cumulants of the input samples and phase differential sequences were applied. It is shown that the cumulant-based features have robust anti-noise ability. Simulation results demonstrate that the correct classification probability (Pcc) with the proposed algorithm is higher than the existing approaches at low signal-to-noise ratio (SNR).

Abstract: With the development of high education, the campus network, on the one hand, offers us a convenient means of learning and living, while, on the other hand, some problem emerges on the course of using, such as not coupling, consistency, timing, relative data redundancy between the departments. This article, by researching on the framework of campus network and Cluster knowledge, presents a security and data integration method of campus network design and plan. By this approach, the effective and overall integration, secure information exchange is complemented between departments of campus network.

Abstract: The unstable areas caused by radio interference or rapidly change of nodes' location always emerge inevitably and unpredictably in the WSN (Wireless Sensor Network) of large scale. They may seriously hinder the route discovery procedures in the network. An improved routing strategy named AONDVjr (Ad hoc On-demand Navigated Distance Vector Junior) which keeps monitoring and exploiting unstable areas in ZigBee networks is proposed in this paper. This scheme selects navigation nodes at the borders of unstable areas by comparing and analyzing the parameters including area stability and node’s depth. The navigation nodes will provide source nodes with latest and short routes through unstable areas and forward data packets to sink node.

Abstract: The CPM and PERT are the most popularly used underlying method of schedule planning of construction project, Problematically, CPM and PERT depend on the experiences of project manager, which is not true in railway construction project. A huge deviation occurs between the actual progress and planned schedule. This leads to unreasonable allocation of resources and cost increment. Referring to the characteristics of schedule planning of railway construction projects, we proposed schedule planning conceptual model of railway construction project based on CAS. The model consists of three parts. They are master schedule, forecasting planning and operational planning. Forecasting planning is produced by master schedule and adjusted by operational planning dynamically. In addition, RBF neutral network is employed to improve the accuracy of master schedule. The paper provides novel viewpoint and idea for project management of railway construction.

Abstract: With pervasive perception and deep correlation, smart city provides wisdom city services, which accelerates the progress of digital city and optimization of city managements. Because of the ubiquitous perception and pervasive intelligent services, the key basis is the deep data correlating services on demand, which involves an amount of domains, departments, themes, spatial and temporal dimensions. For the needs of smart city, a well-designed overall architecture is proposed with detailed explanation. Furthermore, a plain data vitalization method and midware with corresponding diagram are represented, as well as an application sample. The proposed architecture and approaches is the foundation for following researches and useful reference for the study of smart city.

Abstract: In this paper, a weak current detection circuit is designed for developing organophosphorous pesticides rapid detection portable instrument. The detection principle is based on the electrochemical characteristic of enzyme catalyzing substrate of acetylcholinesterase biosensor for detecting pesticide residues. Based on the behavior of cyclic voltammograms (CV) of the acetylcholinesterase biosensor, the data acquisition and processing circuit of the weak current signals generated by the biosensor is designed, which including the I/V conversion, differential amplification , low-pass filter, A/D conversion etc. Eventually, the 0~5V voltage signal are obtained and they are proportional to the weak current from the enzyme biosensor. The designed detection circuit has a good consistence compared with electrochemical analysis instrument, which can establish a good base for developing organophosphorous pesticides rapid detection portable instrument.

Abstract: An Intelligent Chinese Text File Inquiry System (ICTFIS) is introduced in this paper. The system is used to serve the national materials information sharing platform. The ICTFIS provided a user friendly interface with Chinese nature language as its inquiry language. The automatic abstraction model, one of the most important models of the system, is also discussed in detail