2,066 research outputs found

    EAST: Energy Efficient Adaptive Scheme for Transmission in Wireless Sensor Networks

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    In this paper, we propose Energy-efficient Adaptive Scheme for Transmission (EAST) in WSNs. EAST is IEEE 802.15.4 standard compliant. In this approach, open-loop is used for temperature-aware link quality estimation and compensation. Whereas, closed-loop feedback helps to divide network into three logical regions to minimize overhead of control packets on basis of Threshold transmitter power loss (RSSIloss) for each region and current number of neighbor nodes that help to adapt transmit power according to link quality changes due to temperature variation. Simulation results show that propose scheme; EAST effectively adapts transmission power to changing link quality with less control packets overhead and energy consumption compared to classical approach with single region in which maximum transmitter power assigned to compensate temperature variation

    Simulation Analysis of Medium Access Techniques

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    This paper presents comparison of Access Techniques used in Medium Access Control (MAC) protocol for Wireless Body Area Networks (WBANs). Comparison is performed between Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), Pure ALOHA and Slotted ALOHA (S-ALOHA). Performance metrics used for comparison are throughput (T), delay (D) and offered load (G). The main goal for comparison is to show which technique gives highest Throughput and lowest Delay with increase in Load. Energy efficiency is major issue in WBAN that is why there is need to know which technique performs best for energy conservation and also gives minimum delay.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Com- munication and Applications (BWCCA 2012), Victoria, Canada, 201

    The Overshot Gate as a Flow-Measuring Device

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    The overshot gate is a commonly used adjustable overflow weir for regulating the upstream water level in open channels. The amount of gate movement is proportional to the water level change. However, to effectively manage the water flow, it is also important for operators to accurately measure the flow rate in the channel. This study examines an overshot gate installed at the end of a laboratory flume to estimate the flow rate under various free flow conditions. This study investigates different gate angles ranging from 9.6° to 90° to evaluate their impact on the flow properties and the discharge coefficient. The analysis of the results indicates that the maximum flow rate values can be achieved with gate inclinations from 15.5° to 47.2° with relatively lower head; the inclined alignment of the gate decreases the effective gate height which consequently increases the gate efficiency. The use of the overshot gate is advantageous over the normal gate when channel depth is limited and higher discharge is required at relatively lower head. In this study, at the highest gate inclinations, the water surface is significantly stable having the lowest values of the approach Froude number. In addition, the head to gate height ratio decreases with raising the gate due to the reduced vertical contraction of the channel. Finally, this paper proposes an empirical equation for estimating the discharge coefficient based on the gate inclination, which demonstrates good accuracy in the specified range

    Estimate and Classify the Hardness of Different Water Sources by Using Prepared Soap Solution

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    This research includes available techniques and simplified methods to estimate and classify the quality of hardness for different water supply sources like sea water, various wells (Fayda, khabyar, jumbyar) and tap water of Basrah ,Mosul, Duhok and Baghdad, by using prepared soap solution from different commercial liquid soap with different concentration (SS1,2,3 , SS4,5,6 , SS7,8,9 ). The hardness of water is relative to the formation of foam (suds) when soap solution is added to water samples until a foam layer of a certain height (2cm) formed. We determine the volume (in drops, milliliter) of soap solution. If there is a lot of foam formed quickly with little soap solution, the water is rather soft. If you need to add a lot of soap solution to produce a certain height of foam, the water is rather hard. Many factor that establish during experiments, the quality of water supply, measuring degree of hardness, concentration of water samples. Compared with the results of laboratory tests for water stations of Mosul gave our method of encouraging and positive results to continue in the future, so liquid soap bubbles (foam) are a good indicator of classifying types of water. Key words: Estimate and classify the hardness of different water sources, New and simple calculations 

    Performance Analysis of Hierarchical Routing Protocols in Wireless Sensor Networks

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    This work focusses on analyzing the optimization strategies of routing protocols with respect to energy utilization of sensor nodes in Wireless Sensor Network (WSNs). Different routing mechanisms have been proposed to address energy optimization problem in sensor nodes. Clustering mechanism is one of the popular WSNs routing mechanisms. In this paper, we first address energy limitation constraints with respect to maximizing network life time using linear programming formulation technique. To check the efficiency of different clustering scheme against modeled constraints, we select four cluster based routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient sensor Network (TEEN), Stable Election Protocol (SEP), and Distributed Energy Efficient Clustering (DEEC). To validate our mathematical framework, we perform analytical simulations in MATLAB by choosing number of alive nodes, number of dead nodes, number of packets and number of CHs, as performance metrics.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

    The effects of poverty and prison on British Muslim men who offend

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    © 2018 by the author. Focusing on the lives of British Muslim young men, this article examines the links between their social and economic relations and their prison experiences, desistance, and identity. In understanding the meanings they place on their prison experiences and their social and economic marginalization, the article theorises about social integration, and their place in British society. An intergenerational shift from the availability of local high-waged, skilled, and secure textile work to low-waged, precarious, service work presented them with a series of problems and opportunities, leading them to reject licit wage labour and embrace illicit entrepreneurial criminality. The article concludes that their social and economic relations drove criminal solutions, not ethnicity

    On Modeling Geometric Joint Sink Mobility with Delay-Tolerant Cluster-less Wireless Sensor Networks

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    Moving Sink (MS) in Wireless Sensor Networks (WSNs) has appeared as a blessing because it collects data directly from the nodes where the concept of relay nodes is becomes obsolete. There are, however, a few challenges to be taken care of, like data delay tolerance and trajectory of MS which is NP-hard. In our proposed scheme, we divide the square field in small squares. Middle point of the partitioned area is the sojourn location of the sink, and nodes around MS are in its transmission range, which send directly the sensed data in a delay-tolerant fashion. Two sinks are moving simultaneously; one inside and having four sojourn locations and other in outer trajectory having twelve sojourn locations. Introduction of the joint mobility enhances network life and ultimately throughput. As the MS comes under the NP-hard problem, we convert it into a geometric problem and define it as, Geometric Sink Movement (GSM). A set of linear programming equations has also been given in support of GSM which prolongs network life time

    Growth of Output and Productivity in Pakistan’s Agriculture: Trends, Sources, and Policy Implications

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    The paper aims to review the growth performance of Pakistan’s agriculture from 1950 to 1995. The long-term growth rate of agriculture, although respectable, has exhibited considerable yearly fluctuations even between decades. The period of the fifties and early seventies lacked any growth. Accelerating and high growth rates marked the decade of the sixties but the performance has not been satisfactory since 1979-80 and average growth rates have barely exceeded the population growth rate, with widespread implications for growth of national economy, food security, and social welfare of the masses. Area, modern inputs, and technology have been the major determinants of growth but prices were equally important because of their incentive and disincentive effects. The agriculture price policies adopted during the 1980s are known to have had a negative effect on the development and use of technology in agriculture. In order to boost agricultural productivity, a change in price policy is needed to ensure incentive prices. This could be done by setting agricultural commodity prices at par with corresponding import and export parity prices. A higher investment in research and development can hardly be overemphasised. There is an urgent need to remove the bottlenecks in agricultural input markets since these markets represent the typical monopoly position. To break up the monopoly of registered dealers and to promote competition, free sales in the open market by interested parties and individuals may be allowed.
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