Query expansion based on relevance feedback and latent semantic analysis

Web search engines are one of the most popular tools on the Internet which are widely-used by expert and novice users. Constructing an adequate query which represents the best specification of users’ information need to the search engine is an important concern of web users. Query expansion is a way to reduce this concern and increase user satisfaction. In this paper, a new method of query expansion is introduced. This method which is a combination of relevance feedback and latent semantic analysis, finds the relative terms to the topics of user original query based on relevant documents selected by the user in relevance feedback step. The method is evaluated and compared with the Rocchio relevance feedback. The results of this evaluation indicate the capability of the method to better representation of user’s information need and increasing significantly user satisfaction

MHD Boundary Layer Flow near Stagnation Point of Linear Stretching Sheet with Variable Thermal Conductivity via He’s Homotopy Perturbation Method

MHD boundary layer flow near stagnation point of linear stretching sheet with variable thermal conductivity are solved using He’s Homotopy Perturbation Method (HPM), which is one of the semi-exact method. Similarity transformation has been used to reduce the governing differential equations into an ordinary non-linear differential equation. The main advantage of HPM is that it does not require the small parameter in the equations and hence the limitations of traditional perturbations can be eliminated. In this paper firstly, the basic idea of the HPM for solving nonlinear differential equations is briefly introduced and then it is employed to derive solution of nonlinear governing equations of MHD boundary layer flow with nonlinear term. The influence of various relevant physical characteristics are presented and discussed

A provably secure really source hiding designated verifier signature scheme based on random oracle model

A lot of designated verifier signature (DVS) schemes have been proposed. However, all of them only provide the basic security requirement that only the designated verifier can check the validity of the signature. They are either not secure enough or lacking source hiding. Hence, in this article, we design a provably secure DVS scheme. It not only can attain the basic security requirement but also hide the original signer’s identity which makes our scheme more suitable for the applications in an electronic voting system