Applied Mechanics and Materials Vol. 441

Abstract: In this paper, we propose a novel resource allocation criterion based on physical layer security, which means choosing the proper subcarrier to ensure the device to device (D2D) security capacity maximum based on guaranteeing the cellular users basic capacity. We analyze the relationship between D2D security capacity and D2D power. We also prove that the strategies based on the D2D secrecy rate maximum and cellular sum rate maximum are the same when the transmit SNR of BS is high enough. Through the numerical calculation and simulation analysis, we show that the resource allocation criterion proposed in this paper is valid and rational.

Abstract: Calibration of radio frequency (RF) unit is a must during researching and manufacturing of wireless transceiver system. Automation calibration plays an important role in promoting productivity effect. This paper focuses on the design of automation calibration of RF unit in wireless transceiver system. Design of automation calibration is separated by two parts, one is transmission (Tx) power calibration, the other is receive signal strength indicator (RSSI) calibration.

Abstract: As a high-frequency and broadband wireless transmission system [, wireless microwave transmission system plays an important role in wireless communication family, especially in newest WiMax and 4G technology. Wireless microwave transmission system can be separated by indoor unit (IDU) and outdoor unit (ODU). This paper is focused on the design of IDU and ODU.

Abstract: In converged networking, the evaluation of network performance is completed by analyzing the key performance indexes which can reflect the states of network from the point of user view and integrated results should be evaluated by user or quality of experiences. This paper proposes the algorithm for evaluation of network performance based on the fuzzy analytic hierarchy process that utilizes strategy data and key performance indexes to calculate the integrated results of evaluation. The result provides the necessary reference for the real-time monitoring of network.

Abstract: As the development of the semantic web, RDF data set has grown rapidly, thus causing the query problem of massive RDF. Using distributed technique to complete the SPARQL (Simple Protocol and RDF Query Language) Query is a new way of solving the large amounts of RDF query problem. At present, most of the RDF query strategies based on Hadoop have to use multiple MapReduce jobs to complete the task, resulting in waste of time. In order to overcome this drawback, MRQJ (using MapReduce to query and join) algorithm is proposed in the paper, which firstly uses a greedy strategy to generate join plan, then only one MapReduce job should be created to get the query results in SPARQL query execution. Finally, a contrast experiment on the LUBM (Lehigh University Benchmark) test data set is conducted, the results of which show that MRQJ method has a great advantage in the case that the query is more complicated.

Abstract: In this paper, we present and study a new system framework, which achieves allocation of cloud resource and guarantees response time of application requests and service rate of cloud resources. This architecture consists of three important components: queue controller, resource monitor and scale controller. The system leverages priority queue is used to assure response time of application requests. The resource monitor will measure the workload and resource status in cloud environment. In scale controller, an algorithm is proposed to guarantee service rate by adding/reducing cloud resources and address the tradeoffs between cost and service rate to avoid a waste of cloud resources. Finally, we evaluate this system framework through verifying feasibility and stability.

Abstract: An important new technology has recently been developed that will revolutionize trust and security for online transactions. Conventionally, most of the security-relevant functions are concentrated within the operating system. Often, these functions, especially those dealing with access control, are commingled with object management functions. This article, abstracted from a new book on the subject, explains the key concepts and the exciting potential of Trusted Computing Platforms (often abbreviated to Trusted Platforms). We discuss access control in multilevel database management systems applies and illustrate the main applies of access control based on Trusted Computing in the LogicSQL database system.

Abstract: Researching the design process of scientific research management information system of Jiangmen polytechnic. According to the characteristics of the scientific research management in colleges and universities, the system is developing by using the B/S application model and the advanced .NET framework. The system consists of teachers management module, faculty-level management module, and library management module, scientific research department management module, system management module and public management module. Aim at the application maintenance and security, the system uses three-tier architecture, authorize to the management mechanism, data encryption and software separation and other security measures. The system has realized the classification audit of scientific research information and the dynamic management of the research integral reports. The using results show that the system is not only stable, but also easy to operate, and it also greatly improves the accuracy and efficiency of the scientific research management.

Abstract: Aiming at the issue of resource integration in mobile collaboration environment, a novel method named MCRF-MRSG, which is the resource integration method for mobile collaboration environment based on resource semantic and information granularity, was proposed. Firstly, the information of researches relevant was given such as resource description language, resource description framework and so on. Then, the notation of resource semantic granularity was proposed and the construction of MCRF-MRSG model was described based on resource semantic. After that, the static and dynamic characteristics of the model were analyzed. And the correction of the model was verified through engineering practice. Practice shows that the model of this paper has the correct semantics and engineering practical value.

Abstract: Radio frequency identification and localization is a key technology in the Internet of Things. This paper reports an ARM Cortex-M3 processor based hand-held radio frequency identification and localization terminal and a 8051 processor based active radio frequency tags. The terminal and the tags utilize STM32F103VET6 and the low power consumption STC12LE4052AD as their master controller, respectively. Both of them use Nordic nRF24L01 as their radio frequency identification module. The system works in 2.4GHz ISM microwave band and can read, write and locate radio frequency tags within 20m indoors. The actual measurement of active radio frequency tags shows that this terminal is highly stable and comparable in 2.4GHz microwave frequency radio identification and localization.