The Study Of The Collaboration Mechanism For General Brower Under DOA

Attributed to complex geological conditions, China frequently suffers geologicalmovements. Geological hazards, such as collapses, landslides, mudslides, surfacecollapses, ground subsidence, and ground fissure are widely distributed. In recent years,affected by the extreme weather, severe emergent geological hazards occur frequently,which brings great damages to people’s life and the economic development of ourcountry. In order to further enhance the geological hazard prevention, avoid or decreasethe loss geological hazards bring to our country, combining with science andinformation technology, establishing an effective geological hazard early warning andprevention measure has its significance and urgency.The amount of geological hazard data is huge, and has the characteristics of timeand space, multi-source, distributed, multi-scale, multi-resolution and multi-temporal，among which time and space, and distributed characteristics lead to the large workingregion of geological hazard prevention work which brings obstacles to communicationsbetween staff. CSCW (Computer Supported Cooperative Work) experienced decadesof development, has been applied to many areas, and achieved significance results.Combining CSCW with geographic information system can solve the communicationproblems for the geological hazard monitoring and prevention work.DOA (Data Oriented Architecture), is a system architecture model with data as thecore, identifiers as the main line, which uses XML-based data registration and dataexchange standard to realize data sharing and exchange among different systems.General browsers based on DOA have the functions of information aggregation andservice polymerization. DOA, taking C/S and B/S as reference, can effectively organizeand manage massive and isomeric spatial data, which offers a theory basis forcollaborative working mechanism. First of all, this article gives a brief description of CSCW and its use in differentareas, then the introduction of General Browser based on DOA, including its functionsand features, and its importance to geological hazard monitoring and prevention. Thisarticle based on the analysis of current CSCW technology, and geological hazardmonitoring and prevention, put forward a General Browser collaboration mechanismbased on DOA.The main work includes:(1) Study Web Services technology and SOAP protocol.Collaborative objects need exchange information frequently, how to reliably andeffectively exchange information is the key to collaborative communication system.Study the structure, service description, transmission type of Web Services andcommunication protocol SOAP, combining spatial information technology, incorporateWeb Services into CSCW system.(2) Study data exchange standard used for collaborative communicationplatform.Geological hazard data possess strong time and space characteristics, and also canbe classified into structured and unstructured data. The source and use of geologicalhazard data vary greatly, which brings many troubles to management and sharing.Based on XML, design a data exchange standard to realize integrated organization andmanagement of structured and unstructured data of geological hazard.(3) Study the functionalities and message service model of CSCW system.Study the CSCW system from four aspects–collaborative information sharing,collaboration access control, collaborative member communication and collaborationvisualization system. For collaborative member communication, combined with thecharacteristics of geological hazard monitoring and prevention work, mainly designedpeer-to-peer communication and “publish/subscribe” message model.The innovation points and achievements are as follows:(1) Put forward a General Browser collaborative communication dataexchange standard, which uses C2ML as expression language.C2ML (Collaboration Communication Markup Language) is an extension ofHGML (Hyper Geographic Markup Language) in collaboration communication field.The grammar structure and rules adopt that of XML, and based on XML definingdedicated data types. The same as KML and GML, it is compatible with OGC standard.C2ML is used to define the format of body of SOAP message.(2) Put forward a General Browser collaborative communication model based on DOA.With reference to the feature of the data structure of geological hazard and DOA,established data exchange standard based on C2ML, which in turn defined the structureof SOAP message. According to data sharing and exchange conception of DOA, makeuse of metadata management mechanism of data registration center, combined with therequirement of geological hazard monitoring and prevention, studied“publish/subscribe” model and WS-Notification, preliminary established the GeneralBrowser collaborative communication model based on DOA.(3) The design of data exchange standard expression markup language-C2ML, used for collaborative communication among General Browsers.This article studied the characteristics of CSCW and the specifications of WS-Notification, and designed the label structure of C2ML. The entire label set consists ofdata description labels and collaborative communication description labels.(4) The design of the collaborative communication model for GeneralBrowser based on Web Services.This article studied the four elements of CSCW, combined with the conception ofDOA and the requirements of geological hazard monitoring and prevention, designedthe collaborative communication model under DOA. This model, based on WebServices, includes metadata searching component, peer-to-peer communicationcomponent and “publish/subscribe” component, and solved the communicationproblems among General Browsers under heterogeneous platform environment.