4,304 research outputs found

    An a posteriori error analysis of a mixed finite element Galerkin approximation to second order linear parabolic problems

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    In this article, a posteriori error estimates are derived for a mixed finite element Galerkin approximation to second order linear parabolic initial and boundary value problems. Using mixed elliptic reconstruction method, a posteriori error estimates in L(L2)L^\infty(L^2) and L2(L2)L^2(L^2)-norms with optimal order of convergence for the solution as well as its flux are proved for the semidiscrete scheme. Finally, based on backward Euler method, a completely discrete scheme is analyzed and a posteriori bounds are derived, which improves earlier results on a posteriori estimates for mixed parabolic problems

    JPEG2000 compatible neural network based cipher

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    In this paper, an efficient encryption technique is proposed, especially for JPEG2000 compatible images.The technique uses a multilayer neural network to generate a pseudo-random sequence for transforming wavelet subbands into cipher subbands.The neural network generator takes 64 bit key as a startup seed with additional 64 bit key for initial weights and biases.At each layer, output is calculated by several iterations to increase the complexity of the pseudorandom sequence generation.In order to examine effectiveness of this approach, various tests including correlation, histogram, key space etc. are conducted on test images, and the results demonstrate the robustness of the proposed approach

    MODLEACH: A Variant of LEACH for WSNs

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    Wireless sensor networks are appearing as an emerging need for mankind. Though, Such networks are still in research phase however, they have high potential to be applied in almost every field of life. Lots of research is done and a lot more is awaiting to be standardized. In this work, cluster based routing in wireless sensor networks is studied precisely. Further, we modify one of the most prominent wireless sensor network's routing protocol "LEACH" as modified LEACH (MODLEACH) by introducing \emph{efficient cluster head replacement scheme} and \emph{dual transmitting power levels}. Our modified LEACH, in comparison with LEACH out performs it using metrics of cluster head formation, through put and network life. Afterwards, hard and soft thresholds are implemented on modified LEACH (MODLEACH) that boast the performance even more. Finally a brief performance analysis of LEACH, Modified LEACH (MODLEACH), MODLEACH with hard threshold (MODLEACHHT) and MODLEACH with soft threshold (MODLEACHST) is undertaken considering metrics of throughput, network life and cluster head replacements.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

    Economic Implications of Water Efficiency Measures II: Cost Effectiveness of Composite Strategies

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    This is the final version of the article. Available from the publisher via the DOI in this record.This paper briefly describes the development and application of a tool for generating micro-components (e.g. baths, taps, showers, WCs, washing machines and dishwashers) based water efficient composite strategies and assesses their cost effectiveness using a number of economic assessment methods. A composite strategy is defined as a combination of micro-components that could deliver a given water efficiency level. The assessment results suggest that the economic performance of water efficient composite strategies varies considerably. There is no linear relationship between water and energy consumption and the total cost associated with the strategies. Additionally, conventional cost assessment methods appear to be unsuitable for identifying the least cost options to consumers.The work was funded by the UK Engineering and Physical Sciences Research Council (EPSRC) and its support is thankfully acknowledged

    Economic implications of water efficiency measures II: cost effectiveness of composite strategies

    Get PDF
    This is the final version of the article. Available from the publisher via the DOI in this record.This paper briefly describes the development and application of a tool for generating micro-components (e.g. baths, taps, showers, WCs, washing machines and dishwashers) based water efficient composite strategies and assesses their cost effectiveness using a number of economic assessment methods. A composite strategy is defined as a combination of micro-components that could deliver a given water efficiency level. The assessment results suggest that the economic performance of water efficient composite strategies varies considerably. There is no linear relationship between water and energy consumption and the total cost associated with the strategies. Additionally, conventional cost assessment methods appear to be unsuitable for identifying the least cost options to consumers.The work was funded by the UK Engineering and Physical Sciences Research Council (EPSRC) and its support is thankfully acknowledged

    Testing Onion Market Integration in Pakistan

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    This paper analyses spatial market integration using monthly wholesale real price of onion in four regional markets located in each of the four provinces of Pakistan. Unit root test indicates that the price series in each location are stationary, and the series are represented as autoregressive model for eachlocation. The error correction model results show that the regional markets of onion have strong price linkages, and thus are spatially integrated.

    Single-bit adaptive channel equalization for narrowband signals

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    In this paper, a new design of a single-bit adaptive channel equalization is proposed using sigma delta modulation and a single-bit block Least Mean Square (LMS) algorithm. With correlated narrowband input signals, this model is capable to converge and provide equivalent equalization filter with improvement in the SNR and very low Symbol Error Rate (SER). The input, filter coefficients and output values are all in single-bit and ternary format that results in a reduction in hardware complexity compared to traditional multi-bit channel equalization. Additionally, the technique avoids the need for successive conversion from multi-bit to single bit and back at the receiver and transmitter stages
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