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: Comparative Study of Traditional Requirement Engineering and Agile Requirement Engineering
Authors: Asma Batool , Yasir Hafeez Motla , Bushra Hamid , Sohail Asghar, Muhammad Riaz , Mehwish Mukhtar, Mehmood Ahmed
Abstract: Traditional RE and Agile RE are two different approaches on the basis of their planning and control mechanism. This Paper distinguishes the Traditional RE and Agile RE. Furthermore it investigates the reasons for which software industries shifted from Traditional RE to Agile RE. Research is carried out by conducting a literature study and finally a case study of software development to evaluate which approach has better success rate than other. With the help of our finding and results we have evaluated that Agile RE performs better than Traditional RE in large organizations where changes evolve throughout the development phase of software life cycle. Keywords- Requirement Engineering , Traditional Requirement Engineering, Agile Requirement Engineering, Scrum, Extreme Programming, Obj ect Oriented Development, Requirement Elicitation, Requirement Analysis, Requirement Management, Software Requirement Specification.
Publish Year: 2013
Published in: ICACT – IEEE
موضوع: مهندسی نرم افزار
ایران سای – مرجع علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: NANOIMPRINTED HOLES TO IMMOBILIZE MICROBES
Authors: T Kano, T Inaba, and N Miki
Abstract: In this paper we demonstrate highly dense immobilization of bacteria into nanoimprinted holes. Nanoimprinting enables micro holes smaller than 2 mm in diameter with a high accuracy, which cannot be patterned using conventional UV photolithography. In our prior work, we developed a microbial reactor immobilizing bacteria into micro holes, which facilitated collection and evaluation of reaction products while the number of bacteria involved in the reaction could be quantified. However, the holes were made by photolithography and the minimum size was limited to be 3 mm in diameter. Large holes allow multiple bacteria to be immobilized in a hole, which resulted in errors in quantification. The number of bacteria immobilized in a nanoimprinted hole was found to have smaller deviation than in photolithographically formed holes. In addition, density of the immobilized bacteria was experimentally found to be largest in case of 2-mm-holes. The proposed processes will be of great help for precise evaluation of bacteria reaction.
Publish Year: 2013
Published in: IEEE-MEMS
موضوع : فناوری نانو (Nanotechnology)
ایران سای – مرحع علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Effect of Higher-Order PSDs on Timing Jitter
Authors: Isamu Wakabayashi , Daisuke Abe, Masatoshi Sano
Abstract: This paper describes the effect of higher-order PSDs at a squarer output on the jitter variance at a timing circuit output. The timing circuit consists of a squarer, a pre-filter, and a PLL arranged in tandem. The transmission schemes are assumed to be PAM, ASK and QAM. Additive white Gaussian noise exists at the receive filter input. The band-limiting scheme is assumed to be of a cosine roll-off. The higher-order PSDs are components of the jitter source PSD at the squarer output. Theoretical calculations show that the SS and SN components of the jitter source PSD can be represented by Oth- and ±2nd-order PSDs. However, based on numerical calculations, the SN component consists of only the Oth-order PSD. This may be due to the effect of the band-limiting scheme assumed herein. The results hold for all of the transmission schemes, SNRs, alphabet sizes, and roll-off factors treated in this paper.
Publish Year: 2013
Published in: ICACT – IEEE
موضوع: الکترونیک
ایران سای – مرجه علمی فنی مهندسی
حامی دانش بومی ایرانیان
به نام خدا
Title: Large nonadiabatic quantum molecular dynamics simulations on parallel computers
Authors: Fuyuki Shimojo , Satoshi Ohmura , Weiwei Mou , Rajiv K Kalia , Aiichiro Nakano , Priya Vashishta
Abstract: Wehave implemented a quantummolecular dynamics simulation incorporating nonadiabatic electronic transitions on massively parallel computers to study photoexcitation dynamics of electrons and ions. The nonadiabatic quantum molecular dynamics (NAQMD) simulation is based on Casida s linear response time-dependent density functional theory to describe electronic excited states and Tully s fewest- switches surface hopping approach to describe nonadiabatic electron ion dynamics. To enable large NAQMD simulations, a series of techniques are employed for efficiently calculating long-range exact exchange correction and excited-state forces. The simulation programis parallelized using hybrid spatial and band decomposition, and is tested for various materials.
Publish Year: 2013
Published in: Computer Physics Communications - Science Direct
موضوع: محاسبات کوانتوم (Quantum Computing )
ایران سای – مرجع علمی فنی مهندسی
حامی دانش بومی ایرانیان