Advanced Materials Research Vols. 108-111

Abstract: Space-time block codes(STBCs) based on coordinate interleaved orthogonal designs (CIOD) are put forward integrally by analyzing the theory of generalized orthogonal designs. In accordance with the principle of Alamouti’s orthogonal receiver, the received signals are firstly processed by vector orthogonal transform, imaginary part exchange and vector-weighted spin processing, then we get the complete demodulation process. Finally, simulations for the transmit diversity configuration A with 4Tx CIOD in 802.16d/e were performed over quasi-static Rayleigh flat-fading channel. The results show that the proposed transmission scheme has a low decoding complexity similar to the classical STBC based on complex orthogonal designs(COD). However, the former can get slightly better performance.

Abstract: In connection with the problems that coal mining accounts for water environment pollution and socio-economic development, the main factors was analyzed. From water environment system, ecological system and socio-economic system, corresponding evaluation index system was perfected and became fit for factual situation. Matter-element model of water environment impact evaluation was constructed and used to evaluate four large-scale coal mining areas. The results showed that assessment model in accordance with the objective reality. Compared with other evaluation models, matter-element model is more accurate and comprehensive. By matlab, a calculating program was made and can be dynamically amended.

Abstract: Recent years, many utilities have experienced catastrophic rupture of critical Prestressing Concrete Cylinder Pipe (PCCP) lines throughout the world. Much attention has been focused on reliably assessing the condition of PCCP mains. However, assessment of embedded prestressing wire is difficult. Continuous acoustic monitoring can provide a means of locating problematic pipe sections. In this paper the application of support vector machine (SVM) in acoustic signal detection is proposed. And the effect of this method is investigated. Some key parameters of SVM and kernel functions are surveyed. SVM methods are more effective, especially for the case of lack of training samples. The experiment shows that the SVM method has good classification ability and robust performances. The techniques can provide the opportunity to identify problematic pipe sections and repair the pipe prior to failure. Therefore it can help to prolong the life of a suspect pipeline while minimizing the potential for catastrophic failure.

Abstract: A power transformer is an important fault reason for a power system, some uncertain factors such as randomness and funniness exist between fault phenomenon and fault mechanism. There are no definite corresponding relations between fault characteristic quantity and fault omens, which make fault diagnosis more difficult. The transformer fault of artificial neutral network diagnosis is more and more paid attention to, but when the normal artificial neutral network calculations to the data are trained, most of them have slow convergent speed, even no convergent. The paper proposed to improve artificial neutral network calculation, thus increase training speed and diagnostic reliability. It states that artificial intelligence system is very useful tool for transformer early hidden faults achieves the possibilities and accuracy of primary diagnosis.

Abstract: In 2009 from the comprehensive competitiveness comparison of nearly 300 cities on district level shown in "Chinese Urban Competitiveness Report", 12 competitivenesses of more than 50 major cities are evaluated by using econometric models, and Chinese most competitive top 10 cities of Year 2009 emerge. Since the city's comprehensive competitiveness ranges many indexes which are difficult to quantify and various best programs with fuzziness, the fuzzy analytic hierarchy process (FAHP) is relatively more scientific and objective. This paper presents Mathematica program which use fuzzy analytic hierarchy process to evaluate the the city's comprehensive competitiveness, and the practicability of FAHP presented in this paper may provide the reference to the researchers in the field.

Abstract: Nowadays open and distributed Computer Supported Cooperative Work (CSCW) systems are faced with security challenges due to large numbers of cooperative users, and a mass of valued data resources need to be protected against unauthorized usage, disseminations and share. To this end, role-based collaboration framework and access control approaches have been a focus in recent years, but there lack of a holistic and comprehensive model and visual modeling. We proposed and formalized a CSCW-enabling access control model integrating generic centralized authorization and distributed authority delegation, called IACM (Integrated Access Control Model) for CSCW, based on the cooperative roles and their owned activities. And then, the visual modeling was represented with static and dynamic characteristics, with a goal to narrow the gap of the formalized model and application level. Finally, an application in the collaboration system for equipments manufacture designing was implemented to improve security of the role-based centralized authorization management by using the authorization constraint rules, and to enhance the collaborative capability based on the user-side delegation mechanism, effectively guaranteeing CSCW system security and authorization management efficiency.

Abstract: This paper presents an adaptive support for Boolean algorithm for mining association rules, the Algorithm does not require minimum support from outside, in the mining process of the algorithm will be based on user needs the minimum number of rules automatically adjust the scope of support to produce the specific number of rules, the algorithm number of rules for the user needs to generate the rules to a certain extent, reduce excavation time, avoid the artificial blindness specified minimum support. In addition, the core of the algorithm is using an efficient method of Boolean-type mining, using the logical OR, AND, and XOR operations to generate association rules, to avoided the candidate itemsets generated In the mining process, and only need to scan the database once, so the algorithm has a certain efficiency.

Abstract: This paper will construct a discrete system's computer model, include the time distribution of buses arrive, stop and passengers’ get down and get off. The emulation clock advanced with the method of incident step length. Through the inversion produce the random variables of Poisson distribution, negative exponential distribution and normal distribution, simulate the conditions of bus arrive, leave and pick up passengers. Finally calculate with the relative data and then get a series of indicators to evaluate the crowing degree of the bus station.

Abstract: This project has operated the traffic survey, collected and analyzed the data， found the congestion of the road and optimized it, alleviated the congestion, evacuated the traffic jams. Taking real intersection as example， this paper records the traffic flow and timing control, analyzes traffic condition. At the last, this study simulates the traffic operation status under the present condition with traffic simulation software VISSIM and improves the signal timing.

Abstract: In this paper we mainly discuss the traffic accident information management system which based on web software platform of WINDOWS NT using PB as front developing tool and adopting the database of SYBASE as its core. The system can make statistical analysis and prediction for road accident caused by many factors and can determine the Black Spot of accident through analysis thus can provide basis for preventing the accident and rebuilding the dangerous road section.