In this article, the dispersion of PROPAGATION waves in an arbitrary direction in laminated composite plates is studied in the framework of elasticity. Three-dimensional field equations of elasticity are considered, and the characteristic equation is obtained on employing the continuity of displacements and stresses at the layers' interfaces. Obtained characteristic equation is further simplified by making use of the properties of the block matrices. Some important particular cases such as of free waves on reducing plates to single layer and the surface waves when thickness tends to infinity are also discussed. Numerical results are also obtained and represented graphically.

Software maintenance is an important phase of the software life cycle. An important task in this phase is to locate code fragments a ected by user change requests. However, performing this task manually is costly and requires prior knowledge of the software structure. In previous studies, Latent Semantic Indexing (LSI) has been applied to map the user change queries to the relevant code segments automatically. However, due to the lack of domain knowledge embedded in the source code, LSI might be unable to perform this mapping accurately. In this paper, we have proposed a domain knowledge PROPAGATION method to obtain more relevant impact set for each change request. This method spreads the user interface originated domain knowledge to the program classes according to the program dependency graph. The proposed method has been applied to ArgoUML case-study which is an open-source project associated with its change requests. It was observed that applying the concept PROPAGATION resulted in 5% increase in the accuracy of the plain LSI method.