380,290 research outputs found

    Qualitative Analysis of Subsurface Water Quality in Challakere Taluk, Karnataka, India

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    Rural India relies mainly on groundwater for drinking and agriculture. Unsustainable withdrawal of groundwater has led to the spectra of depleting the problem of water scarcity. The available groundwater quality is not only contaminated by hazardous pathogenic germs and anthropogenic substances but also geogenic substances is adversely affect the water supply of many regions. The groundwater of Challakere taluk had many threats such as anthropogenic activities, quality deterioration by agricultural activities and over exploitation and also persistence of continuous drought condition. This paper mainly addresses the physico-chemical concentration of 30 groundwater samples during August 2009 in Challakere taluk, Karnataka (India). The results of all the findings are discussed in details which reflect the present status of the groundwater quality of the study area. Groundwater is extremely important to the future economy and growth of rural India. If the resource is to remain available as high quality water for future generation it is important to protect from possible contamination. Hence it is recommended that suitable water quality management is essential to avoid any further contamination

    Qualitative Analysis of String Cosmologies

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    A qualitative analysis is presented for spatially flat, isotropic and homogeneous cosmologies derived from the string effective action when the combined effects of a dilaton, modulus, two-form potential and central charge deficit are included. The latter has significant effects on the qualitative dynamics. The analysis is also directly applicable to the anisotropic Bianchi type I cosmology.Comment: 13 pages, 4 postscript figures, accepted to Physical Review

    A Qualitative Analysis of Online Gaming:

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    The popularity of Massively Multi-Player Online Role-Playing Games (MMORPGs) has risen dramatically over the last decade. Some gamers spend many hours a day in these virtual environments interacting with others gamers, completing quests, and forming social groups. The present study set out to explore the experiences and feelings of online gamers. The study comprised 71 interviews with online gamers (52 males and 19 females) from 11 different countries. Many themes emerged from the analyses of the interview transcripts including (i) relationship with social networking, (ii) social interaction, (iii) the community, (iv) learning real-life skills, (v) reinforcement schedules and operant conditioning, (vi) game design and content, (vii) escaping from real life, (viii) playing longer than intended, and (ix) gamers’ obligations towards others in online worlds. These findings specifically showed the social networking capabilities of online gaming, the community aspects and the psychological mechanisms within MMORPGs that can lead to excessive online gaming. The implications of these findings are discussed in relation to previous qualitative and quantitative research in the area

    Qualitative Analysis of Early Universe Cosmologies

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    A qualitative analysis is presented for a class of homogeneous cosmologies derived from the string effective action when a cosmological constant is present in the matter sector of the theory. Such a term has significant effects on the qualitative dynamics. For example, models exist which undergo a series of oscillations between expanding and contracting phases due to the existence of a heteroclinic cycle in the phase space. Particular analytical solutions corresponding to the equilibrium points are also found.Comment: Submitted to Journal of Mathematical Physics, 18 pages, 4 figures, uses package "graphicx" to insert figure

    Qualitative Analysis of Causal Cosmological Models

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    The Einstein's field equations of Friedmann-Robertson-Walker universes filled with a dissipative fluid described by both the {\em truncated} and {\em non-truncated} causal transport equations are analyzed using techniques from dynamical systems theory. The equations of state, as well as the phase space, are different from those used in the recent literature. In the de Sitter expansion both the hydrodynamic approximation and the non-thermalizing condition can be fulfilled simultaneously. For Λ=0\Lambda=0 these expansions turn out to be stable provided a certain parameter of the fluid is lower than 1/2. The more general case Λ>0\Lambda>0 is studied in detail as well.Comment: RevTeX file, 23 pages. Accepted for publication in J. Math. Phy

    Qualitative Analysis of Concurrent Mean-payoff Games

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    We consider concurrent games played by two-players on a finite-state graph, where in every round the players simultaneously choose a move, and the current state along with the joint moves determine the successor state. We study a fundamental objective, namely, mean-payoff objective, where a reward is associated to each transition, and the goal of player 1 is to maximize the long-run average of the rewards, and the objective of player 2 is strictly the opposite. The path constraint for player 1 could be qualitative, i.e., the mean-payoff is the maximal reward, or arbitrarily close to it; or quantitative, i.e., a given threshold between the minimal and maximal reward. We consider the computation of the almost-sure (resp. positive) winning sets, where player 1 can ensure that the path constraint is satisfied with probability 1 (resp. positive probability). Our main results for qualitative path constraints are as follows: (1) we establish qualitative determinacy results that show that for every state either player 1 has a strategy to ensure almost-sure (resp. positive) winning against all player-2 strategies, or player 2 has a spoiling strategy to falsify almost-sure (resp. positive) winning against all player-1 strategies; (2) we present optimal strategy complexity results that precisely characterize the classes of strategies required for almost-sure and positive winning for both players; and (3) we present quadratic time algorithms to compute the almost-sure and the positive winning sets, matching the best known bound of algorithms for much simpler problems (such as reachability objectives). For quantitative constraints we show that a polynomial time solution for the almost-sure or the positive winning set would imply a solution to a long-standing open problem (the value problem for turn-based deterministic mean-payoff games) that is not known to be solvable in polynomial time

    Italy

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    Qualitative Analysis of Universes with Varying Alpha

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    Assuming a Friedmann universe which evolves with a power-law scale factor, a=tna=t^{n}, we analyse the phase space of the system of equations that describes a time-varying fine structure 'constant', α\alpha, in the Bekenstein-Sandvik-Barrow-Magueijo generalisation of general relativity. We have classified all the possible behaviours of α(t)\alpha (t) in ever-expanding universes with different nn and find new exact solutions for α(t)\alpha (t). We find the attractors points in the phase space for all nn. In general, α\alpha will be a non-decreasing function of time that increases logarithmically in time during a period when the expansion is dust dominated (n=2/3n=2/3), but becomes constant when n>2/3n>2/3. This includes the case of negative-curvature domination (n=1n=1). α\alpha also tends rapidly to a constant when the expansion scale factor increases exponentially. A general set of conditions is established for α\alpha to become asymptotically constant at late times in an expanding universe.Comment: 26 pages, 6 figure
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