Research & Implementation Of B-A-Arch.-Based Embedded Internet Information Retrieval Model

Along with the development of chips and the trends of Internet mobilization and personalization, Embedded Internet System (EIS) is concerned by more and more researchers. We can image that if Embedded Systems (ES) link to Internet, information will be transmitted to any place in the world conveniently and cheaply, which will enable us retrieve information at any time, at any place, and by any equipment with wide prospect. Researching Embedded Internet Information Retrieval (EIIR) is not only very necessary academically but also profitable economically, and will accelerate social renovation of information ultimately.However, ES' environment is execrable relatively; its hardware energy loss, size, cost, reliability, bandwidth, speed, processing ability, etc are all in the collar. Meanwhile, the Browser/Server mode, the compression technology and today's Internet technology are not designed for the ES, therefore at present, they can't satisfy the embedded applications, and neither can ES retrieve information conveniently from the Internet. How to overcome the disadvantages mentioned above are the emphases and the difficulty of our research.This dissertation addresses the above issues and presents the following solutions:1) Proposes a Broker-Agent (B-A)-architecture-based Embedded Internet information retrieval technology, and implements a model system. The system is composed of two physical parts: one is Browser Side Broker (BSB), another is Server Side Agent (SSA), so the system need not change the settings of Web server or browser, and is easy to be deployed. By adding the Presentation Interlayer and the Logic Interlayer from the point of view of logical level, the system can pool large numbers of computing and net flow onto agent-server side, so it can not only minimize transmission data between the browser and embedded facilities' gateway, and save the limited bandwidth but also improve the response time.2) Proposes the dynamic pages caching management strategy, which induces its definitions, theorems, concept of background Time-to-Live of dynamic pages, cachecoherency and replacement algorithm of dynamic pages. Furthermore, designs and implements a knowledge-based request analyzer, a differencing engine based on the block differences isolating algorithm. Applying this strategy can largely reduce transmission data between BSB and SSA and can improve the response time efficiently.3) Defines the concepts of resources multi- modality, fidelity, E-value function template and constraints, and proposes the solution of single-constraint optimization and multi-constraint optimization. Designs and implements an adaptive Web resources optimal strategy, which can better express the producers' notion and improve the expressive force of the embedded browser.4) Proposes and implements an improved semi-structured-oriented data compression algorithm: LZWX. LZWX expands some concepts of the traditional LZW algorithm, so that text is not encoded/decoded char by char but meta-string by meta-string. The algorithm can reduce transmission data between browser and SSA, so as to cut down the bandwidth occupation and the energy consumption.Finally, the experiment results indicate that our system can overcome the weakness of EIS effectively and the limitation when applied the Browser/Server mode.