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Information Sciences Letters
An International Journal



Numerical solution of a space-time fractional derivative of groundwater flow equation

Abstract :
The classical Darcy law is generalized by regarding the water flow as a function of a non-integer order derivative of the piezoŽmetric head. This generalized law and the law of conservation of mass are then used to derive a new equation for groundwater flow. Two methods including Frobenius and Adomian Decomposition method are used to obtain an asymptotic analytical solution to the generalized groundwater flow equation. The solution obtained via Frobenius method was valid in the vicinity of the borehole this solution was in perfect agreement with the data observed from the pumping test performed by the institute for groundwater study on one of their borehole settled on the test site of the University of the Free State. The test consisted of the pumping of the borehole at the constant discharge rate Q and monitoring the piezometric head for 350 minutes. Numerical solutions obtained via Adomian method are compared with the Barker generalized radial flow model for which a fractal dimension for the flow is assumed. Proposition for uncertainties in groundwater studies was given


Detection of Wood Image with Rot Based on BP Neural network

Mu Hongbo,
Abstract :
Wood defect with rot reduces wood quality badly. X-ray is selected to be the testing source for nondestructive testing. The wood images with rot obtained from X-ray were preprocessed and extracted feature. The feature parameters were preprocessed and were input into BP neural network, and then the wood defects can be recognized. The experimental results show that the detection rate can be up to 86% and the performance shows that this method is very successful for detection and classification of wood defects. This study offers a new method for automatic detection of wood defects. It is useful for the scientific selection and effective utilization of wood resources.


Research on the Multicast Protection Algorithm Based on QoP+QoS in WDM Networks

Li Du,
Abstract :
Single link failure is the primary form of all kinds of network failures. Protecting survivable multicast sessions against single link failures in WDM networks has been becoming more and more important. Furthermore, measuring and improving the QoS (Quality of Service) and QoP (Quality of Protection) is of great significance to the development of multicast sessions with the enhancement of peoples consciousness of QoP and QoS. This paper studies the multicast protection approaches and algorithms based on QoP+QoS and puts forward some innovative designs. Firstly, we do qualitative and quantitative analyses about QoP+QoS. Secondly, VS_MFBG scheme based on VS (Virtual Source) is presented to save resources. What is more, we innovatively propose SDP_QPS (Shared Disjoint Paths based on QoP+QoS) algorithm. Shown in the simulation results, these designs can not only improve the rate of resource utilization, but also decrease the blocking probability and average delay.


Research on Interference Suppression of Pseudo-random Code Phase Modulation Fuse Based on EDTWD Analysis method

Yin Dafeng,
Abstract :
The anti-jamming ability of pseudo-random code phase modulation fuse is very strong. But the effectiveness of suppressing narrow-band interference is limited by the signal bandwidth. Thus, an effective method is developed to identify the narrow-band interference in the wide-band spread spectrum signal. Extended discrete-time Wigner-Ville distribution (EDTWD) analysis method is adopted to extract and reconstruct the narrow-band interference in the received signal of pseudo-random code phase modulation fuse. Then the interference is cancelled by the adaptive interference cancellation. The method doesn’t require any prior knowledge of interference signal, makes the received signal distorted little and can also be used in the circumstance of some interference sources. The simulation result showed that the interference signal after being separated and then synthesized had the similar frequency characteristics as before.



Abstract :
A category of singularly perturbed boundary value problem for nonlinear equation of fourth order with two parameters is considered here. The Adomian decomposition and Variational iteration techniques are used to propose an asymptotic solution to this problem. Some examples are given to demonstrate the effectiveness of the two techniques for solving the boundary value problems of nonlinear equation of fourth order with two parameters. The two solutions are compared for small and large x.



A.Aghili, B. Parsa Moghaddam,
Abstract :
In this study, new theorems and corollaries on multi-dimensional Laplace Transformations have been presented. In addition, some applications based on these results have been developed. The two-dimensional Laplace Transformation is useful in the solution of partial differential equations. Some illustrative examples related to impulsive non - homogenous partial differential equations have also been provided.


Hyers-Ulam Stability of Linear Operators in Frechet Spaces

P. Sam Johnson, S. Balaji,
Abstract :
Hyers-Ulam stability of a linear operator between Frechet spaces is de ned. Necessary and sucient conditions for the existence of Hyers-Ulam stability of a bounded linear operator from a Frechet space to another Frechet space are given.


High Variability Resilient in Nano-Scaled Technologies for Low power 7T-SRAM Design

Shyam Akashe, Sanjay Sharma,
Abstract :
High variability in nano-scaled technologies can easily disturb the stability of a carefully designed standard 6TSRAM cell, causing access failures during a read/write operation. We propose a 7T-SRAM cell to increase the read/write stability under large variations. The proposed design uses a low overhead read/write assist circuitry to increase the noise immunity. Use of an additional transistor and a floating ground allows read disturb free operation. While the write assist circuitry provides a floating ground during a write operation that weakens cell storage by turning off the supply voltage to ground path of the cross-coupled inverter pair. This allows a high speed/low power write operation. Monte Carlo simulations indicate a 200% increase in the read stability and a boost of 124% in write stability compared to a conventional 6T-SRAM design, when subjected to random dopant fluctuations, line edge roughness, and poly-granularity variations. HSPICE simulations of a 45nm 64x32 bit SRAM array designed using standard 6T and proposed 7T SRAM cells indicate a 31% improvement in write speed, 30% decrease in write power, read power decreases by 60%, and a 44% reduction in the total average power consumption is achieved with the proposed design.

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