14,529 research outputs found

    Re-Scaling of Energy in the Stringy Charged Black Hole Solutions using Approximate Symmetries

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    This paper is devoted to study the energy problem in general relativity using approximate Lie symmetry methods for differential equations. We evaluate second-order approximate symmetries of the geodesic equations for the stringy charged black hole solutions. It is concluded that energy must be re-scaled by some factor in the second-order approximation.Comment: 18 pages, accepted for publication in Canadian J. Physic

    Productivity and performance of irrigated wheat farms across canal commands in the Lower Indus Basin

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    Irrigated farmingWheatProductivityPerformance evaluationWater managementCropping systemsWater supplySoil propertiesModels

    Water for rural development: Background paper on water for rural development prepared for the World Bank

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    Water management / Irrigation management / Rural development / Water resources development / Small scale systems / Land management / Groundwater / Environment / Health / Water policy / Institutions / Food consumption / Water supply / Water demand / Water allocation / Crop yield / Cereals / Water scarcity / Food production / Food security / Crop production / Population growth

    A WiFi-based Reliable Network Architecture for Rural Regions

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    WiFi is being considered as an attractive option in providing low cost Internet connectivity to rural areas, and thereby reducing Digital Divide with urban areas. Most of the WiFi-based Long Distance network architectures extend Internet to rural regions through a single gateway node which is connected to high speed Internet. If the gateway node fails in such single gateway-based rural networks, the entire network gets collapsed. In this paper, we propose a reliable and low-cost WiFi based rural network architecture using multi-gateway concept. The proposed network architecture also allows load balancing among the available gateways. In such multi-gateway architecture, the network recovers from gateway failure and reestablishes the ongoing communication within 2-4 seconds time. The simulation results in NS-2 validate the claims of the paperKeywords—Digital Divide, WiFi, WiFi based Long Distance Network

    Lead Isotope Determinations by Mass Spectrometry and Its Application by Isotope Dilution Technique

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    A method for the determination of Lead isotope ratios by thermal ionization mass spectrometry (TIMS). This method also describes the application of isotope dilution mass spectrometry (IDMS) to the field of reference material (RM) characterization focusing on the approach. Emphasis is placed on IDMS measurements of highest analytical quality. Basic principles as well as the equation system are being recalled. The evaporation and ionization currents are determined for a measurement of isotopic ratios of head, employing double rhenium filament assembly in the ion source and Faraday cup as the detector using the presently available RM.         

    Predicting Breast Cancer Survivability

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    this study concentrates on Predicting Breast Cancer Survivability using data mining, and comparing between three main predictive modeling tools. Precisely, we used three popular data mining methods: two from machine learning (artificial neural network and decision trees) and one from statistics (logistic regression), and aimed to choose the best model through the efficiency of each model and with the most effective variables to these models and the most common important predictor. We defined the three main modeling aims and uses by demonstrating the purpose of the modeling. By using data mining, we can begin to characterize and describe trends and patterns that reside in data and information. The preprocessed data set contents were of 87 variables and the total of the records are 457,389; which became 93 variables and 90308 records for each variable, and these dataset were from the SEER database. We have achieved more than three data mining techniques and we have investigated all the data mining techniques and finally we find the best thing to do is to focus about these data mining techniques which are Artificial Neural Network, Decision Trees and Logistic Regression by using SAS Enterprise Miner 5.2 which is in our view of point is the suitable system to use according to the facilities and the results given to us. Several experiments have been conducted using these algorithms. The achieved prediction implementations are Comparison-based techniques. However, we have found out that the neural network has a much better performance than the other two techniques. Finally, we can say that the model we chose has the highest accuracy which specialists in the breast cancer field can use and depend on

    Land and water productivity of wheat in the Western Indo-Gangetic Plains of India and Pakistan: a comparative analysis

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    Wheat / Crop yield / Productivity / Climate / Irrigation canals / Watercourses / Water distribution / Water allocation / Policy / India / Pakistan / Gangetic Plains / Kaithal Irrigation Circle / Bhakra Canal / Chaj Sub-Basin / Lower Jehlum Canal
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