Research Of Chemical Information For Public Service

The rapid development of Internet has brought people into an information explosion era.It becomes more and more difficult to acquire a piece of useful information from the overload web world.The idea is:get data in the web as inquire from the database.Characteristics of Internet such as large quantity,isomeric and dynamic variation make the information saving and extracting being different from the traditional methods.It is also a problem for information analyst.This thesis is based on the chemical engineering information research program which conducted by Shanghai Institute of Organic Chemistry.It is about the research of chemical information for public service,and it gives ways of saving and extracting information and the duplicate removal algorithm.Compared to the traditional methods, there are some advantages.The whole paper is composed of seven parts as follows:Chapter1:Introduction.The part gives a brief introduction of the chemical information development in both here and abroad.It also put forward the subject, difficulties and originalities of this research.Chapter2:The analysis and design of the chemical information system.It introduced the whole process of collecting information,the source of information, collecting tools and standards.Chapter3:Formation of product and supply public service through internet. People can search information by many ways.Chapter4:Acquisition of chemical information.It introduced the feature of web information resource and how to collect it.Chapter5:Duplicated webpage deletion.We put forward an approach for duplicated webpage deletion according to the webpage slice based on.net platform.In combination with the characteristics of webpage structure and special field text,and users can define the similarity value to reach a satisfactory deletion result.It is shown by the experimental result that this method can effectively improve the accuracy of duplicated web-pages deletion.Chapter6:Information extracting.There are two typical extracting methods,one is based on template and the other is machine study.We decided to adopt a method based on domain knowledge ontology.Chapter7:The Information service examples.The last part is a summary which points out some disadvantages.