4,406 research outputs found

    Characterization and control of small-world networks

    Get PDF
    Recently Watts and Strogatz have given an interesting model of small-world networks. Here we concretise the concept of a ``far away'' connection in a network by defining a {\it far edge}. Our definition is algorithmic and independent of underlying topology of the network. We show that it is possible to control spread of an epidemic by using the knowledge of far edges. We also suggest a model for better advertisement using the far edges. Our findings indicate that the number of far edges can be a good intrinsic parameter to characterize small-world phenomena.Comment: 9 pages and 6 figure

    Institutional Impediments to Groundwater Trading: the case of the Gnangara groundwater system of Western Australia

    Get PDF
    The development of a market in groundwater usage rights can be inhibited by constraints arising from the institutional context. Such impediments may reduce the potential gains from trade and may generate high transaction costs for prospective traders. We analyse the regulations and policies influencing groundwater transfers in a case-study area -- the Gnangara groundwater system around Perth, Western Australia -- and identify significant impediments to a groundwater market. Property rights are found to be conditional, temporary, and vulnerable to amendment. Regulatory approval is required for all transfers. Facilitating infrastructure is lacking, and price information is unavailable. Management area boundaries reflect land ownership and use rather than hydrogeological realities; the limitation of transfers to within these boundaries eliminates much of the potential for gains from trade. Over-allocation and weak monitoring also impede the development of a market. The current management system is likely to obscure unmet demand for water-rights transfers between users and usage-types.Agricultural and Food Policy, Environmental Economics and Policy, Institutional and Behavioral Economics, Land Economics/Use, Political Economy, Public Economics, Resource /Energy Economics and Policy, Q15, Q25, Q28, Q38, Q56, Q57, Q58, D02, R52, H41, H23, H11, D23, D47, D78, H44,

    Manifestations of Drag Reduction by Polymer Additives in Decaying, Homogeneous, Isotropic Turbulence

    Get PDF
    The existence of drag reduction by polymer additives, well established for wall-bounded turbulent flows, is controversial in homogeneous, isotropic turbulence. To settle this controversy we carry out a high-resolution direct numerical simulation (DNS) of decaying, homogeneous, isotropic turbulence with polymer additives. Our study reveals clear manifestations of drag-reduction-type phenomena: On the addition of polymers to the turbulent fluid we obtain a reduction in the energy dissipation rate, a significant modification of the fluid energy spectrum especially in the deep-dissipation range, a suppression of small-scale intermittency, and a decrease in small-scale vorticity filaments.Comment: 4 pages, 3 figure

    Nutritional Status of School Age Children (5-14 years) in a Rural Health Block of North India (Kashmir) Using WHO Z-Score System

    Get PDF
    Objective: To assess the nutritional status of school going children in Rural Block Hajin. Methods: School children from various primary and middle level educational facilities from a rural health block were surveyed during the School Health Program. Height and weight was measured following standard procedures. MS Excel and Interactive statistics page were used for analysis of data. Results: Both mean weight and height were higher in females than males. The overall prevalence of under nutrition was 19.2%. The prevalence of underweight was lowest in 5 year female (0.0%) and highest in 6 year male (21.5%). For Stunting 7 year males recorded the lowest (0.0%) and 12 year males the highest (28.5%) prevalence. The highest and lowest prevalence of wasting was recorded in 6 year old females (2.56%) and 9 year old males (24.6%) respectively. Prevalence of thinness was lowest in 13 year old females (14.2%) and highest in 13 year old males (47.1%).Conclusion: The nutritional status of school age children in this health block are comparatively better even though a large number of children still fall below the cutoff for various nutritional indicators

    Spreading and shortest paths in systems with sparse long-range connections

    Full text link
    Spreading according to simple rules (e.g. of fire or diseases), and shortest-path distances are studied on d-dimensional systems with a small density p per site of long-range connections (``Small-World'' lattices). The volume V(t) covered by the spreading quantity on an infinite system is exactly calculated in all dimensions. We find that V(t) grows initially as t^d/d for t>t^*$, generalizing a previous result in one dimension. Using the properties of V(t), the average shortest-path distance \ell(r) can be calculated as a function of Euclidean distance r. It is found that \ell(r) = r for r<r_c=(2p \Gamma_d (d-1)!)^{-1/d} log(2p \Gamma_d L^d), and \ell(r) = r_c for r>r_c. The characteristic length r_c, which governs the behavior of shortest-path lengths, diverges with system size for all p>0. Therefore the mean separation s \sim p^{-1/d} between shortcut-ends is not a relevant internal length-scale for shortest-path lengths. We notice however that the globally averaged shortest-path length, divided by L, is a function of L/s only.Comment: 4 pages, 1 eps fig. Uses psfi

    Penehcyclidine and awareness during anaesthesia: caution with zero numerators

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96392/1/anae12114.pd

    System Reliability Estimation in Multicomponent Exponential-Lindley Stress-Strength Models

    Get PDF
    A stress-strength model is formulated for a multi-component system consisting of k identical components. The k components of the system with random strengths ( ) 1 2 , ,..., k X X X are subjected to one of the r random stresses ( ) 1 2 , ,..., r Y Y Y . The estimation of system reliability based on maximum likelihood estimates (MLEs) and Bayes estimators in k component system are obtained when the system is either parallel or series with the assumption that strengths and stresses follow Lindley distribution and Exponential distribution respectively. A simulation study is conducted to compare MLE and Bayes estimator through the mean squared errors of the estimators

    Coping practices and gender relations: Rohingya refugee forced migrations from Myanmar to India

    Get PDF
    Rohingya experiences of displacement and refuge are heavily gendered. Sexual and gender-based violence have been used as weapons against Rohingya women, men, girls and boys in Myanmar for decades. Trafficking and exploitation are rife on the flight out of the country, and host states such as India present their own gendered challenges to family survival and individual coping. In this paper, we examine how some of those violent and disruptive experiences have affected gender roles for individuals and families as they have fled Myanmar (often more than once) and sought refuge in India via Bangladesh. We present new insight into the dynamic subjectivity of Rohingya women as we show how, contrary to dominant depictions of passive victimhood, many have lead family migration across borders, taken up NGO/community leadership roles, or made the best ‘home’ possible within the limitations of the host context. This is because personal and family agency is sensitive to transitional opportunities and threats—i.e., gender norms of home and host contexts, interactions with host communities, and trust relations with NGOs, to name a few. Crucially, these social practices and experiences are not static or linear; they spa
    corecore