Advanced Materials Research Vols. 850-851

Abstract: In the large capacity of computing technology, this article sets up the statistic recurrence calculating method of linear algebra pseudosolution by making use of the optimal filter theory. So we can get recurrence form of pseudosolution under the linear simultanuity and linear non-simultanuity instead of using the complex calculating pseudo-inverse matrix. This method is reliable and its effect is excellent. The results of the discussion show that the method of this article will provide an effective mathematic processing method in order to realize the optimal calculating of complex system of linear equations in the large capacity of calculating.

Abstract: This paper designs an L-Band 1880-1980 MHz low spurious Multi-tuned frequency synthesizer. The frequency source utilizes a DDS to directly stimulate a PLL, which makes a balance between the DDS and the PLL complementary to each other, realizing better specifications. Meanwhile, in order to achieve better spurious suppression with wide loop bandwidth, a method based on triple tuned algorithm is introduced. This algorithm avoids the high level spurious components triggered by the DDS falling in PLL’s bandwidth, refining the structure of the DDS-directly-stimulating PLL circuit frequency lock time and spurious to improve performance. The simulation result shows that the frequency source achieves a frequency range of 1880MHz～1980MHz, a frequency resolution of 1MHz, a spur better than 80dBc, a phase noise of -103dBc/Hz@100kHz and a frequency lock time less than 2 μs.

Abstract: With the development of power electronics technology, a variety of unbalanced load are connected to the grid, causing the grid voltage imbalance and power quality decline, seriously affect the user's normal use. Traditional three-leg inverter can output three-phase symmetrical voltage in the case of three-phase symmetrical load. But it is difficult to output three-phase symmetrical voltage when the three-phase load is asymmetric. In order to solve the impact of unbalanced load on the power quality, the three-phase four-leg inverter which is obtained with the addition of a bridge arm on the basis of traditional three-leg inverter is adopted in this paper. Therefore, the three-phase symmetrical voltage can be acquired in the case of unbalanced load, at the same time, with the advantages of simple structure, small size, light weight, higher voltage utilization.

Abstract: In this paper, ESD improvements of an output driver that driving a large current in DC brushless fan ICs under HBM ESD stress is investigated. In order to improve ESD robustness, some protection blocks will be designed and implemented by the layout parameters and structures tuning. From the preliminary ESD testing result, it was found that the positive Pad-to-VSS (PS) zapping mode of the original DUT is weakest for the output driver of DC brushless fan ICs during an HBM zapping. After a systematic improvement, it is found that the FOD structure of adding protection circuits can effectively protect the whole-chip ESD damage, as compared with the original DUT; the values of ESD failure threshold (V_ESD) are increased > 57%, which allows output driver devices more robust in the ESD immunity.

Abstract: To address the security risks of information systems to make accurate quantitative assessment of problems in the OWA operator and based on gray theory DHGF algorithm is proposed based on combining advantages of both information security risk assessment methodology. Information security risk assessment based on an a priori sample value index depth of excavation, the use of the basic methods of OWA operator, objective indicators derived property rights, and the use of gray theory for assessing the value of integration. This approach will be applied to information security risk assessment, to ensure the objectivity of the evaluation results, while reducing dependence on the assessed value of integrity, to solve the traditional information security risk assessment methodology for index data have special requirements, it is difficult strictly objective and quantitative problems. Assessment examples show the effectiveness of the method and objectivity.

Abstract: In order to to provide an effective, high performance and practical solution for voice communication base on web mobile over internet protocol in the telepresence system. The paper used one method which contained optimization algorithm of voice communication in the telepresence system. We also designed one web mobile famework structure and voice communication terminal configure .Empirical results show that solution guarantees the Qos of the voice data stream and enhances the efficiency of network resources oice communication base on web mobile over internet protocol in the telepresence system.

Abstract: In this paper, we study the digital ear thermometer controlled by MSP430F149 microcomputer. The system gets the temperature by using infrared temperature measurement module TN9. We can display the temperature on the LED and broadcast the real-time temperature by speaker.

Abstract: In order to solving the establishment problem of satellites formation establishing in elliptical orbits, the problem of Lambert transfer based on two-impulse control with unfixed time and initial position is studied. The Niche Genetic Algorithms (NGA) is used to locating the optimal transfer orbit, and the transfer time and initial position are coded into genetic algorithms, as well as the fitness functions are designed to total coasting. The results show that the NGA can solve the optimization problem of two-impulse control effectively, furthermore, the performance of NGA is more effective than the traditional genetic algorithm. The research provides a way for satellites formation establishing based on two-impulse control.

Abstract: Nowadays, we need more convenient facilities to start from the digital microcontroller technology, towards digital control, intelligent control for the modern work, scientific research and life. Compared with the traditional experimental box, P89V51RB2 single chip experiment box is more easy to use, has accurate reading, contain comprehensive and practical experimental circuits. To satisfy the demand of higher school, add other functions such as assembly language based on the existing experimental box.

Abstract: Webpage tamperproof technology is a website technology to protect webpage not to display tamper contents and to carry out real-time recovery. Webpage tamperproof system uses advanced Web server core embedded technology and tamper detection technology based on cryptography to give a comprehensive protection of static webpage and dynamic webpage of the website. Webpage tamperproof system supports the automatic release, tamper detection, application protection, warning, and real-time recovery of webpage, guarantees the safety of various links of transmission, identification, address access, form submission, and auditing, fully eliminates the possibility of access to tampered webpage in a real-time manner, and puts an end to any tamper of backstage database in a manner of Web.