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Research On Network Communication And Intelligentization Technology Of Digital Seismograph

Posted on:2007-12-01Degree:DoctorType:Dissertation
Country:ChinaCandidate:H T WangFull Text:PDF
GTID:1100360185478867Subject:Solid Earth Physics
Abstract/Summary:PDF Full Text Request
The Technologies for network communication and intelligentization in network seismic observation are researched in this dissertation. The network features in network digital seismic observation are implemented completely, and intelligences, such as self-maintain, self-adaptation to environment are implemented at a certain degree too. It may meet the needs of network seismic observation.The dedicated embedded Linux operating system researched in this dissertation is a custom-built version from the open source Linux operating system. The size of the open source Linux operating system is decreased by selection of only necessary components, cut of some unnecessary codes, and addition of device driver for special devices in our network seismograph system. The dedicated embedded Linux operating system is a standard timesharing multi-user operating system and it has main features of that kind of operating systems, but its size is much smaller compared with them. It supports the industrial standard TCP/IP computer network protocol in low layers. The application layer protocols, telnet, ftp, http are also implemented. Then, the network digital seismograph may merge with computer network seamlessly.THE reliability and quality of output data are greatly improved by adding the codes for the CPLD device driver, WatchDog, hard-disk timeout management, GPS timing service, etc, to the dedicated embedded Linux operating system. Especially, the timing error is less than 100 μs, it is on the same level as the international products.The application of XML, the extensible Markup Language, a structure data description language, is researched in this dissertation to manage system parameters effectively and flexibly. A class for parameters management with XML is developed to implement parameter management with XML. All methods for management of parameters with XML are defined in this class. Based on XML, the parameters architecture may be described and expressed accurately, and it is possible for the code for parameter management not to be modified, but the parameter structure to be modified. It is important to improve level of reusability of code.The multi-user programs are run in a multi-user operating system. The one of the key points is the communication among different programs. The schedule for message exchange and data communication based SYS V shared memory is given in this dissertation based on research of a few communication methods among processes. A method for exchange of message based on filesystem is also researched in this dissertation.Size of data is effective to the specifications of the system in the data storage and the data services of network digital seismograph. The application of STEIM2 data compression algorithm of SEED in network digital earthquake observation is researched in this paper. A compressed format for data storage and data services is given to save space for data storage media and band width for transportation.The research of schedules for real time data services based on computer network is stressed in this dissertation, and various schedules for network data service are given for adaptation to different environments. In normal case, the passive data service may be used, it is safety for it use system account message to authorize the connections, and it may serve...
Keywords/Search Tags:Intelligentization
PDF Full Text Request
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