Advanced Materials Research Vols. 403-408

Abstract: In order to optimize electric- arc welding （ERW） welded tube scheduling , the paper introduces data cleaning, data extraction and transformation in detail and defines the datasets of sample attribute, which is based on analysis of production process of ERW welded tube. Furthermore, Decision-Tree method is adopted to achieve data mining and summarize scheduling rules which are validated by an example.

Abstract: AJAX is a new technology, which was published by Java community in 2005, and immediately cried up by programmers. AJAX integrates many matured techniques. The characters are synchronous dealing with UI element in client side, asynchronous sending message to server, accepting data, then only updating the elements which need to be updated, no need to update the whole page. This new mechanism enhances B/S efficiency greatly. The author has applied AJAX to WebGIS project and the effect is great. This paper introduces work theory of AJAX and technique rout to apply it to WebGIS.

Abstract: The effect of the phase deviation on the phase shifter in a 2 × 4 optical 90 hybrid without cross-over is discussed based on a set of formulas derived for the output of this structure. We found that if the two power inputs are equal, the phase deviation of the phase shifter only introduces attenuation in output AC component, and if not equal, it not only introduces the AC component attenuation, but also leads to DC component differentiation, which degrades the optical signal-to-noise ratio of the quadrature output.

Abstract: The quality of ultrasonic flaw echo signal is the foundation of achieving qualitative and quantitative analysis in the in ultrasonic flaw detection. In practice, the flaw echo signals are often contaminated or even annihilation by random noise. According to the characteristics of ultrasonic flaw echo signal, wavelet packet has more accurate local analysis ability in low frequency and high frequency part. This paper discusses de-noising in ultrasonic signals based on wavelet packet analysis, and proposes an improved threshold approach for de-noising. The results show that: It remarkably raises the signal-to-noise ratio of ultrasonic flaw echo signal and improves the quality of signal with improved wavelet packet threshold.

Abstract: On the basis of introducing multi-wavelet theory, a new soft-threshold function is proposed, and the de-noising effect of Ultrasonic signal is investigated by adopting different preprocessing methods of various multi-wavelet. An improved matrix preprocessing method is proposed for GHM also. Simulation results indicate that the selection of a proper preprocessing method is important for multi-wavelet de-noising. Therefore, it is of great importance to choose a suitable preprocessing method and multi-wavelet in order to obtain a better de-noising effect.

Abstract: As one of the most valid method of solving the status of “data explosion”, and “information lack” that current enterprise information systems are faced with, data mining is paid maximum attention to the academia and enterprise. This paper centers on the application of Web Mining, combines the features of E-commerce and sets forth data resources, basic methods, system construct and typical applications of data mining in electronic commerce in detail.

Abstract: Discretization of continuous attributes have played an important role in machine learning and data mining. They can not only improve the performance of the classifier, but also reduce the space of the storage. Univariate Marginal Distribution Algorithm is a modified Evolutionary Algorithms, which has some advantages over classical Evolutionary Algorithms such as the fast convergence speed and few parameters need to be tuned. In this paper, we proposed a bottom-up, global, dynamic, and supervised discretization method on the basis of Univariate Marginal Distribution Algorithm.The experimental results showed that the proposed method could effectively improve the accuracy of classifier.

Abstract: “ADS-B Messages” transmitted on 1090MHz are the Mode S Extended Squitters. When a Mode A/C fruit interferes with a mode S Extended Squitter, some of ADS-B signals may be received in error. These errors need to be corrected by some correction methods. To solve this problem, an error detection and correction algorithm using cyclic redundancy check (CRC) based on bit and confidence declaration is proposed in this paper. Then, the proposed algorithm using the Verilog hardware description language is verified by MODELSIM joint ISE simulation and realized on Field Programmable Gate Array (FPGA) based on ADS-B system. The results show that the algorithm can effective detect and correct data transmission error, which effective advances the reliability of the signal transmission for ADS-B system.

Abstract: With the development of e-business market, radio frequency identification (RFID) technology is becoming more and more importance. It is often used to identify object because it can work without manual intervention. Several organizations including EPC global and ISO have been working on the standard of RFID all the time in order to promote it using low-cost tags. In particular, the EPC Class-1 Generation-2 standard was accepted as an international standard by ISO/IEC. However, this standard exists some security vulnerabilities. To resolve these vulnerabilities, some protocols conforming to EPC Class 1 Generation 2 was proposed. In this paper, we show the weaknesses which exist in RFID system’s security protocols conforming to EPC Class-1 Generation-2 and submit a new security protocol suitable to the standard, then validate the whole security performance of the new protocol. The safety performance of the new protocol and existing protocols are also compared in this paper .The result shows that the the new protocol could be used in the low-cost tag because of its high security and low communication complexity.

Abstract: The modern industrial society is developing rapidly, but also with unprecedented speed destroy the environment.It is a serious threat to human survival and development. In order to reach more scientific and reasonable evaluation result, this artcle investigating from the environmental performance of enterprises, and through introducing the APH law[1], under the established environmental performance evaluation index system for enterprises, evaluate the environmental performance results. Then guiding enterprises develop environmental protection work correctly, to improve the environmental protection benefits.