3. The data which is extracted from the object tree thus generated is stored in the machinery particulars database using JDBC (Java DataBase Connectivity).
Second step
This step will follow the first step. In this step, the manufacturer's staff in charge stores the data directly into the above mentioned machinery particulars database via the network. The staff then executes the servlet on the www server using the web browser. The servlet communicates with the database using JDBC.
5 Conclusions
It is felt that the following framework presented in this paper is the most standard way for utilizing EDI.
・XML is used to describe the data to be sent.
・The web browser is used as a GUI (Graphical User Interface).
・The application layer on the Web server is written using Java.
・JDBC is used to communicate between the Web server and the database.
Although implementation of this project is not completed in this paper, we think that this framework is proper. The following items also need to be examined in the future.
・Definition of the data to be transmitted
In this paper, the DTD has been determined in a basically simple fashion. This is through the use of a convenient case in which the situation is restricted to the transmission of data from a propeller manufacturer to the classification society. Still, it is generally not so easy to determine the data to be interchanged. The authors think that the results obtained from the study on STEP (Standard for the Exchange of Product model data) may be helpful. However, greater flexibility in changing the data model than is currently possible with STEP will be necessary if determination of data is to be completed within a reasonable period of time. Fortunately, it is felt that the flexibility for describing the data model can be significantly facilitated using XML.
・Namespaces
Consideration needs to be given to utilizing the Namespaces which the W3C recommends in connection with XML. Namespaces are used to avoid the conflict of tags when XML instance uses multiple DTDS defined independently. The data transmitted to the classification society varies according to whether the target is the engine, shafting, pressure vessel, or other type of machinery related item. If these data are processed at one time, it is not easy to define the DTD without inconsistencies arising. Moreover, it would be impractical or impossible to define a single DTD in cases where the sender of the data is different according to the type of equipment being considered. Therefore, the use of Namespaces is essential.
・Security
This paper does not include any investigation or consideration of security. This problem is too large to investigate in our small-scaled experiment. The authors believe that the result of the study concerning security currently being undertaken by many researchers will be able to be used in the near future.
The authors will continue to carry out the experiment described in this paper and present the results upon completion.
Acknowledgements
The authors wish to express their thanks to Mr. Grant Simpson Jennings for his kindly support with the translation.
References
[1] N. Baba and N. Sugawara. Integrated system to assist the work for approval in society. In K. Johansson and T. Koyama, editors, 9th International Conference on Computer Applications in Shipbuilding, 10 1997.
[2] N. BABA. Prototype system of auto-checking of compatibility with society's regulations. In Proceedings of ISME Yokohama '95. The Marine Engineering Society in Japan, 7 1995.
