6,992 research outputs found

    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

    Write-limited sorts and joins for persistent memory

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    To mitigate the impact of the widening gap between the memory needs of CPUs and what standard memory technology can deliver, system architects have introduced a new class of memory technology termed persistent memory. Persistent memory is byteaddressable, but exhibits asymmetric I/O: writes are typically one order of magnitude more expensive than reads. Byte addressability combined with I/O asymmetry render the performance profile of persistent memory unique. Thus, it becomes imperative to find new ways to seamlessly incorporate it into database systems. We do so in the context of query processing. We focus on the fundamental operations of sort and join processing. We introduce the notion of write-limited algorithms that effectively minimize the I/O cost. We give a high-level API that enables the system to dynamically optimize the workflow of the algorithms; or, alternatively, allows the developer to tune the write profile of the algorithms. We present four different techniques to incorporate persistent memory into the database processing stack in light of this API. We have implemented and extensively evaluated all our proposals. Our results show that the algorithms deliver on their promise of I/O-minimality and tunable performance. We showcase the merits and deficiencies of each implementation technique, thus taking a solid first step towards incorporating persistent memory into query processing. 1

    AMCTD: Adaptive Mobility of Courier nodes in Threshold-optimized DBR Protocol for Underwater Wireless Sensor Networks

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    In dense underwater sensor networks (UWSN), the major confronts are high error probability, incessant variation in topology of sensor nodes, and much energy consumption for data transmission. However, there are some remarkable applications of UWSN such as management of seabed and oil reservoirs, exploration of deep sea situation and prevention of aqueous disasters. In order to accomplish these applications, ignorance of the limitations of acoustic communications such as high delay and low bandwidth is not feasible. In this paper, we propose Adaptive mobility of Courier nodes in Threshold-optimized Depth-based routing (AMCTD), exploring the proficient amendments in depth threshold and implementing the optimal weight function to achieve longer network lifetime. We segregate our scheme in 3 major phases of weight updating, depth threshold variation and adaptive mobility of courier nodes. During data forwarding, we provide the framework for alterations in threshold to cope with the sparse condition of network. We ultimately perform detailed simulations to scrutinize the performance of our proposed scheme and its comparison with other two notable routing protocols in term of network lifetime and other essential parameters. The simulations results verify that our scheme performs better than the other techniques and near to optimal in the field of UWSN.Comment: 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

    Contemporary Issues in Current Account Operations in Pakistani IBs - Sharia Compliant Solution

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    Contemporary Sharia scholars have three stances about the Current Account Operations in Pakistani Islamic Banks (IBs) i.e., (i) Ijarah based contract (ii) Wadi'ah based contract, and (iii) Qard based contract. This paper is an attempt to delve into the root causes of the differences of scholars and to find the Sharia-compliant solution acceptable for all. Descriptive as well as applied approaches are used in this paper. Clearing of ambiguity on this issue may result in twofold benefits: from the public point of view, it would satisfy practising Muslims which may result in form of huge deposits in this account (ii) from IBs viewpoint the Current Account is a bonus deposit

    Magnetic Susceptibilities of Solutions of Sodium and Potassium Nitrates

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    Local magnetic anisotropy in BaFe2_2As2_2: a polarized inelastic neutron scattering study

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    The anisotropy of the magnetic excitations in BaFe2_2As2_2 was studied by polarized inelastic neutron scattering which allows one to separate the components of the magnetic response. Despite the in-plane orientation of the static ordered moment we find the in-plane polarized magnons to exhibit a larger gap than the out-of-plane polarized ones indicating very strong single-ion anisotropy within the layers. It costs more energy to rotate a spin within the orthorhombic {\it a-b} plane than rotating it perpendicular to the FeAs layers.Comment: 4 pages, 4 figure

    Synthesis and characterization of silver nanoarticles from extract of Eucalyptus citriodora

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    The primary motivation for the study to develop simple eco-friendly green synthesis of silver nanoparticles using leaf extract of Eucalyptus citriodora as reducing and capping agent. The green synthesis process was quite fast and silver nanoparticles were formed within 0.5 h. The synthesis of the particles was observed by UV-visible spectroscopy by noting increase in absorbance. Characterization of the particles was carried out by X-ray diffraction, FTIR and electron microscopy. The developed nanoparticles demonstrated that E. citriodora is good source of reducing agents. UV-visible absorption spectra of the reaction medium containing silver nanoparticles showed maximum absorbance at 460 nm. FTIR analysis confirmed reduction of Ag+ to Ag0 atom in silver nanoparticles. The XRD pattern revealed the crystalline structure of silver nanoparticles. The SEM analysis showed the size and shape of the nanoparticles. The method being green, fast, easy and cost effective can be recommended for large scale production of AgNPs for their use in food, medicine and materials
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