| The standard system of Chinese train control system(CTCS)is gradually established on the basis of referring to the European train control system(ETCS)specification and other foreign standards,combined with Chinese national conditions,and has become an important basis for the design and development of CTCS.In recent years,with the continuous development of high-speed railways,the train control system technology is constantly improving,and the scope of engineering applications is also expanding.The relevant specifications of the CTCS and ETCS train control systems have been updated respectively.Comparing ETCS and CTCS specifications is one of the effective ways to grasp the differences in the development of train control systems at home and abroad.At the same time,the update and change of train control system specifications also involve the problem of requirements change management.At present,the analysis and comparison of train control system specifications are mainly manual,which has disadvantages such as low efficiency.Therefore,it is necessary to study the automatic analysis methods of train control system specificationsTrain control system requirements specification is the basis of train control system design and development,so this paper takes train control system requirements specification as the research object,combined with the text features of system requirements specification,constructs different LDA models for different application scenarios,so as to complete the comparison of train control system requirements specifications and the establishment of requirements tracking relationship.The main work of this paper is as follows:(1)This paper analyzes the change contents of the CTCS-3 system requirements specification and the difference between the requirements specifications of the ETCS and the CTCS-3,which are used as the basis for the establishment and verification of the paper model.This paper analyzes the text features of the system requirements specification and the characteristics of the tracking relationship between the requirements and the test cases,and points out the problems of train control system terms extraction,cross language and sparse features that need to be solved in specifications text modeling and analysis.(2)A train control system terms extraction method based on conditional random field and rules is proposed.This paper analyzes the features of train control system terms,extracts five features to establish feature template,and formulates part of speech matching rules,and completes the construction of Chinese and English train control system terms dictionaries in turn,and verifies the effectiveness of the dictionaries in the application of train control system text segmentation.(3)A bilingual LDA(Latent Dirichlet Allocation)model based on the fusion of word features is proposed to achieve specifications text comparison.Comparable corpus is constructed based on the alignment of Chinese and English train control system terms,and the bilingual LDA model is established by fusing term frequency–inverse document frequency and word position features.Based on the bilingual LDA model,the cross-language train control system requirements specification comparison process and the different versions of the CTCS-3 system requirements specification comparison process are designed respectively.The effectiveness of the model is proved after comparative analysis.(4)Based on the Labeled-LDA model with fusion of word features,taked functional features as the label input of the model,the tracking relationship between the train control system requirements specification and the test cases is established,and this tracking relationship is used to achieve the goal of automatically obtaining the test cases corresponding to the changed requirements.Figure 66,Table 13,63 References. |
