Sharif Digital Repository

Many software development methodologies are based on modeling the real world. In some of these methodologies, real-world models are gradually transformed into software models, while in others, the real world is only considered as a preliminary source of insight into the physical business domain. Real-world modeling was pushed to the sidelines due to anomalies in real-world modeling approaches; however, with the advent of the Model-Driven Architecture (MDA), real-world conceptual modeling is likely to regain its importance. We propose a method for using Design Patterns in the context of model transformation, where real-world models are refactored through application of these patterns.... 

Secure routing is one of the most important topics in the wireless MANETs networks. MANETs networks don't have a central infrastructure for the management of routing in the networks. Each node independently routes and sends packets, so many attacks such as forging, modifying, and denial of service (DoS), Occur in these networks. In this paper, we present the new protocol, SEAODV; Secure Efficient Ad-hoc on Demand Routing Protocol for MANETs networks. SEAODV is based on the AODV algorithm and in comparison with existing secure AODV protocols such as SAODV, ARAN and SEAR have improved security and performances. SEAODV uses HEAP authentication Scheme with symmetric cryptography and one-way hash... 

Digital documents are usually degraded during the scanning process due to the contents of the backside of the scanned manuscript. This is often caused by the show-through effect, i. e. the backside image that interferes with the main front side picture due to the intrinsic transparency of the paper. This phenomenon is one of the degradations that one would like to remove especially in the field of Optical Character Recognition (OCR) or document digitalization which require denoised texts as inputs. In this paper, we first propose a novel and general nonlinear model for canceling the show-through phenomenon. A nonlinear blind source separation algorithm is used for this purpose based on a new... 

Scanning process usually degrades digital documents due to the contents of the backside of the scanned manuscript. This is often because of the show-through effect, i.e. the backside image that interferes with the main front side picture mainly due to the intrinsic transparency of the paper used for printing or writing. In this paper, we first use one of Non-negative Matrix Factorization (NMF) methods for canceling show-through phenomenon. Then, non-linearity of show-through effect is included by changing the cost function used in this method. Simulation results show that this proposed algorithm can remove show-through effectively  

Digital documents are usually degraded during the scanning process due to the printings existing on the backside of the scanning manuscript. This is often caused by the so called show-through effect, the image that interferes with the main picture due to the intrinsic opacity of the paper. This phenomenon is on type of degradation that one would like to remove. In this paper, we propose a novel and general nonlinear model for show-through phenomenon. A nonlinear blind source separation (BSS) algorithm is used for this particular application in a new recursive and extendible structure for compensating show-through. Finally, we introduce a new structure for removing the show-through and the... 

Many authors simply use band structure of infinite photonic crystals to predict the beam's direction in a finite structure. The validity of this approximation for high frequencies has been questioned by Felbacq (PRL 92, 193902) and instead a dressed (by evanescent waves) transfer matrix has been suggested. In this work, we show through numerical examples that the direction obtained by conventional band structure is more accurate than that of dressed transfer matrix of Felbacq et. al. We also demonstrate that this approximation can be improved by taking the effect of evanescent Bloch modes into consideration. The effect of these modes leads to a constant shift of beam's center inside and far...