2,569 research outputs found

    Economic Analysis of High Fertilizer Input, Over-seeded Clover and Native Pasture Production Systems in the Texas Coastal Bend

    Get PDF
    This paper examined the cost and risk of three grazing systems to provide information on economically sustainable systems for cattle producers in the Texas Coastal Bend. Results indicate the medium input (over-seeded clover) grazing system displays first degree stochastic dominance relative to the high input and no input grazing systems.grazing system economics, forage production economics, Crop Production/Industries, Livestock Production/Industries, Production Economics,

    An ERTS-1 investigation for Lake Ontario and its basin

    Get PDF
    The author has identified the following significant results. Methods of manual, semi-automatic, and automatic (computer) data processing were evaluated, as were the requirements for spatial physiographic and limnological information. The coupling of specially processed ERTS data with simulation models of the watershed precipitation/runoff process provides potential for water resources management. Optimal and full use of the data requires a mix of data processing and analysis techniques, including single band editing, two band ratios, and multiband combinations. A combination of maximum likelihood ratio and near-IR/red band ratio processing was found to be particularly useful

    A multifractal zeta function for cookie cutter sets

    Full text link
    Starting with the work of Lapidus and van Frankenhuysen a number of papers have introduced zeta functions as a way of capturing multifractal information. In this paper we propose a new multifractal zeta function and show that under certain conditions the abscissa of convergence yields the Hausdorff multifractal spectrum for a class of measures

    On the arithmetic sums of Cantor sets

    Full text link
    Let C_\la and C_\ga be two affine Cantor sets in R\mathbb{R} with similarity dimensions d_\la and d_\ga, respectively. We define an analog of the Bandt-Graf condition for self-similar systems and use it to give necessary and sufficient conditions for having \Ha^{d_\la+d_\ga}(C_\la + C_\ga)>0 where C_\la + C_\ga denotes the arithmetic sum of the sets. We use this result to analyze the orthogonal projection properties of sets of the form C_\la \times C_\ga. We prove that for Lebesgue almost all directions θ\theta for which the projection is not one-to-one, the projection has zero (d_\la + d_\ga)-dimensional Hausdorff measure. We demonstrate the results on the case when C_\la and C_\ga are the middle-(1-2\la) and middle-(1-2\ga) sets

    Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    Get PDF
    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T ~10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets

    Golden gaskets: variations on the Sierpi\'nski sieve

    Full text link
    We consider the iterated function systems (IFSs) that consist of three general similitudes in the plane with centres at three non-collinear points, and with a common contraction factor \la\in(0,1). As is well known, for \la=1/2 the invariant set, \S_\la, is a fractal called the Sierpi\'nski sieve, and for \la<1/2 it is also a fractal. Our goal is to study \S_\la for this IFS for 1/2<\la<2/3, i.e., when there are "overlaps" in \S_\la as well as "holes". In this introductory paper we show that despite the overlaps (i.e., the Open Set Condition breaking down completely), the attractor can still be a totally self-similar fractal, although this happens only for a very special family of algebraic \la's (so-called "multinacci numbers"). We evaluate \dim_H(\S_\la) for these special values by showing that \S_\la is essentially the attractor for an infinite IFS which does satisfy the Open Set Condition. We also show that the set of points in the attractor with a unique ``address'' is self-similar, and compute its dimension. For ``non-multinacci'' values of \la we show that if \la is close to 2/3, then \S_\la has a nonempty interior and that if \la<1/\sqrt{3} then \S_\la$ has zero Lebesgue measure. Finally we discuss higher-dimensional analogues of the model in question.Comment: 27 pages, 10 figure

    A renormalisation approach to excitable reaction-diffusion waves in fractal media

    Get PDF
    Of fundamental importance to wave propagation in a wide range of physical phenomena is the structural geometry of the supporting medium. Recently, there have been several investigations on wave propagation in fractal media. We present here a renormalization approach to the study of reaction-diffusion (RD) wave propagation on finitely ramified fractal structures. In particular we will study a Rinzel-Keller (RK) type model, supporting travelling waves on a Sierpinski gasket (SG), lattice

    Old and Young Politicians

    Get PDF
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151327/1/ecca12287_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151327/2/ecca12287.pd

    Ergodic directions for billiards in a strip with periodically located obstacles

    Get PDF
    We study the size of the set of ergodic directions for the directional billiard flows on the infinite band R×[0,h]\R\times [0,h] with periodically placed linear barriers of length 0<λ<h0<\lambda<h. We prove that the set of ergodic directions is always uncountable. Moreover, if λ/h(0,1)\lambda/h\in(0,1) is rational the Hausdorff dimension of the set of ergodic directions is greater than 1/2. In both cases (rational and irrational) we construct explicitly some sets of ergodic directions.Comment: The article is complementary to arXiv:1109.458

    Porosities and dimensions of measures

    Full text link
    We introduce a concept of porosity for measures and study relations between dimensions and porosities for two classes of measures: measures on RnR^n which satisfy the doubling condition and strongly porous measures on RR.Comment: Jarvenpaa = J\"arvenp\"a\"
    corecore