به نام خدا
Title: Dynamic router node placement in wireless mesh networks: A PSO approach with constriction coefficient and its convergence analysis
Author: Chun Cheng Lin
Abstract: Different from previous works, this paper considers the router node placement of wireless mesh networks (WMNs) in a dynamic network scenario in which both mesh clients and mesh routers have mobility, and mesh clients can switch on or off their network access at different times. We investigate how to determine the dynamic placement of mesh routers in a geographical area to adapt to the network topology changes at different times while maximizing two main network performance measures: network connectivity and client coverage, i.e., the size of the greatest component of the WMN topology and the number of the clients within radio coverage of mesh routers, respectively. In general, it is computationally intractable to solve the optimization problem for the above two performance measures. As a result, this paper first models a mathematical form for our concerned problem, then proposes a particle swarm optimization (PSO) approach, and, from a theoretical aspect, provides the convergence and stability analysis of the PSO with constriction coefficient, which is much simpler than the previous analysis. Experimental results show the quality of the proposed approach through sensitivity analysis, as well as the adaptability to the topology changes at different times.
Publish Year: 2013
Published in: Information Sciences - Science Direct
موضوع: شبکه های بی سیم (Wireless Networks)
ایران سای – مرجع علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Efficient and dynamic key management for multiple identities in identity-based systems
Authors: Hua Guo , Chang Xu a , Zhoujun Li a , Yanqing Yao a , Yi Mu
Abstract: The traditional identity-based cryptography requires a user, who holds multiple identities, to hold multiple private keys, where each private key is associated with an identity. Man- aging multiple private/public keys is a heavy burden to a user due to key management and storage. The recent advancement of identity-based cryptography allow a single private key to map multiple public keys (identities); therefore the private key management is simpli- fied. Unfortunately, the existing schemes capturing this feature do not allow dynamic changes of identities and have a large data size proportional to the number of the associ- ated identities. To overcome these problems, in this paper, we present an efficient and dynamic identity-based key exchange protocol and prove its security under the Bilinear Diffie Hellman assumption in the random oracle model. Our protocol requires a relatively small bandwidth for a key agreement communication, in comparison with other existing schemes.
Publish Year: 2013
Published in: Information Sciences - Science Direct
موضوع: رمزنگاری
ایران سای – مرجع علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: A logical approach to fuzzy truth hedges
Authors: Francesc Esteva, Llus Godo, Carles Noguera
Abstract: The starting point of this paper are the works of H jek and Vychodil on the axiomatization of truth-stressing and-depressing hedges as expansions of H jek s BL logic by new unary con- nectives. They showed that their logics are chain-complete, but standard completeness was only proved for the expansions over G del logic. We propose weaker axiomatizations over an arbitrary core fuzzy logic which have two main advantages: (i) they preserve the standard completeness properties of the original logic and (ii) any subdiagonal (resp. super- diagonal) non-decreasing function on [0, 1] preserving 0 and 1 is a sound interpretation of the truth-stresser (resp. depresser) connectives. Hence, these logics accommodate most of the truth hedge functions used in the literature about of fuzzy logic in a broader sense.
Publish Year: 2013
Publisher: Information Sciences - Science Direct
موضوع: منطق فازی
ایران سای – مرجع علمی فنی مهندسی
حامی دانش بومی ایرانیان