Applied Mechanics and Materials Vols. 668-669

Abstract: In the light of the data differences between network television and the Internet, this paper solve the problem of grading IPTV by the introduction of time context information and computing the latent scores based on the traditional and item-based collaborative filtering recommendation algorithm. Construct the user - item, the item - time model and optimize item similarity calculation so as to ease the difficulty of searching the similar item due to the data scarcity. The experimental results show that the improved method can obviously increase the recommendation precision and has a certain effect on reducing the impact of data scarcity compared with the traditional item-based collaborative filtering.

Abstract: Qubits distillation is used to extract key in quantum cryptography. However, it may transmit much data when two parities distill the keys via the synchronous light time and keys’ pulse position. In order to reduce the transmitted data, we compress the information by arithmetic code. In this paper, an improved qubits distillation has been implemented. It is shown through experiment results that the data compression rate of arithmetic code is about 0.13; the transmitted data with compression is less than that without compression. It is suitable for us to distill the qubits with the narrow bandwidth.

Abstract: IPv6 is intended to replace IPv4 in the Internet. Domain Name System (DNS) is an essential component of functionality of Internet. This paper presents new IPv6 characteristics, IPv6 DNS hierarchy, working process of IPv6 DNS, IPv6 address types, representation formats of IPv6 address, forward (reverse) resolver of IPv6 DNS, and the DNS transition from IPv4 to IPv6, combined with the practice to build the IPv6 experimental network of Peking University. We give corresponding solutions for the problems encountered in the IPv6 DNS deployment. This paper is of important reference value for IPv6 network researchers and engineers to build IPv6 DNS service in the IPv6 network.

Abstract: Phased arrays for use in future multifunction systems require wideband elements capable of wide angle scanning. Here we describe the design of a Balance Antipodal Vivaldi Antenna for use in large phased array antenna apertures. The BAVA element height and the array lattice spacing are about λ/2 at the high frequency end of a grating-lobe free operating band. BAVA elements do not require connection with adjacent elements and are therefore attractive for use in phased arrays with modular construction.

Abstract: In order to meet growing demand of storage resources, improve the security and integrity of enterprise information resources, this paper analyzes storage resources status and existing problems of Foshan XY Elec-Mech Limited Corp in the first. Based on detailed analysis of cloud storage hierarchy and its advantages, the cloud storage framework is designed to meet enterprise’s demands, security control strategies and backup strategies are also discussed. After implementation, the integration of information resources in multi-systems and multi-platforms may realized for providing users with massive information storage and access services. Furthermore, when disaster coming, multiple backups may be used to recovery for ensuring the continuity of enterprise’s business processing.

Abstract: Parking problem is being more and more difficult with increasing of total vehicles and lack of parking facilities, it is necessary to guide driver in order to cut down useless driving in the process of searching parking space. This paper designs an Parking Guidance Information System (PGIS) based on ITO technology, Zigbee technology is used to perceive vacancy parking space information and send to parking management system through wireless network, Parking space release system control and ensure the accurate release of information, thus the function of parking guidance is realized, besides this system has the function of reservation through mobile operating platform. The application of the PGIS will contribute to improving the order and efficiency of parking.

Abstract: QC-LDPC can bring a higher coding gain to the FSO system, but the complexity of the decoding algorithm restricted its application in high-speed FSO system.In this paper, it adopts an improved Modified Min-sum Algorithm (MMSA) to reduce the decoding complexity and save decoding time. In this paper, the author programs the decoder with VHDL Hardware Description Language and analyzes the static time of the design with Synplify Pro and QuartusII to verify the correctness. Moreover, each functional unit is downloaded to the EP3C16Q240C8 chip produced by ALTERA Company and encapsulated into the IP core. Finally, we used MATLAB software to build the FSO system for testing decoder performance. The results show that the QC-LDPC decoder based on FPGA has higher reliability in FSO system.

Abstract: The user scheduling and precoding schemes in Multi-User Multiple Input Multiple Output (MU-MIMO) system have the problem of high complexity and the performance of traditional criteria is not good. This paper analysis the advantages of Signal to Leakage plus Noise Ratio (SLNR) criteria firstly, then propose a cross-layer design of user scheduling and precoding scheme based on SLNR criteria. The design only uses SLNR criteria and includes an improved SLNR user scheduling scheme which is accomplished by iteration procedure. Numerical results verify the improved user scheduling scheme can improve the performance of sum capacity and average BER and the cross-layer design has lower complexity.

Abstract: The design of a multiple courses of general exam system development method based on MAS technology. This paper discussed the necessity of development system, the concept of MAS and the organizational structure of MAS, secondly analyzes the system framework, finally introduces the key technologies such as the multi-agent RPC communication model, online exam process etc..

Abstract: Reconciliation protocol is used in quantum cryptography to correct errors in qubits by exchanging information via classical channel. Winnow is a widely used efficient reconciliation protocol. It separates qubits into blocks, then utilizes Hamming coding to remove bit errors in each block. Performance of Winnow protocol relies deeply on the size of the blocks. In this paper, implementation of winnow protocol is introduced and optimization of block size for the protocol is analyzed. It is shown through experiment results that the optimized value of block size is 0.4/BER, where BER is bit error rate of qubits.