2,532 research outputs found

    Murder by the Clock

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    Geometry and Topology of Escape II: Homotopic Lobe Dynamics

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    We continue our study of the fractal structure of escape-time plots for chaotic maps. In the preceding paper, we showed that the escape-time plot contains regular sequences of successive escape segments, called epistrophes, which converge geometrically upon each endpoint of every escape segment. In the present paper, we use topological techniques to: (1) show that there exists a minimal required set of escape segments within the escape-time plot; (2) develop an algorithm which computes this minimal set; (3) show that the minimal set eventually displays a recursive structure governed by an ``Epistrophe Start Rule'': a new epistrophe is spawned Delta = D+1 iterates after the segment to which it converges, where D is the minimum delay time of the complex.Comment: 13 pages, 8 figures, to appear in Chaos, second of two paper

    Geometry and Topology of Escape I: Epistrophes

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    We consider a dynamical system given by an area-preserving map on a two-dimensional phase plane and consider a one-dimensional line of initial conditions within this plane. We record the number of iterates it takes a trajectory to escape from a bounded region of the plane as a function along the line of initial conditions, forming an ``escape-time plot''. For a chaotic system, this plot is in general not a smooth function, but rather has many singularities at which the escape time is infinite; these singularities form a complicated fractal set. In this article we prove the existence of regular repeated sequences, called ``epistrophes'', which occur at all levels of resolution within the escape-time plot. (The word ``epistrophe'' comes from rhetoric and means ``a repeated ending following a variable beginning''.) The epistrophes give the escape-time plot a certain self-similarity, called ``epistrophic'' self-similarity, which need not imply either strict or asymptotic self-similarity.Comment: 15 pages, 9 figures, to appear in Chaos, first of two paper

    Using an unconventional climate record to link glacimarine sediments to turbidite frequencey in the

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    Master of ScienceGeologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/115441/1/39015074253363.pd

    Influence of the International Journal of Exercise Science

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    International Journal of Exercise Science 17(2): 265-273, 2024. The International Journal of Exercise Science (IJES) publishes research from numerous subdisciplines of exercise science and health. This study documented the scholarly influence of the initial 15-year history (2008-2022) of the IJES. Publication, indexing, from the IJES website and four database services: Dimensions, Google Scholar (GS), PubMed, and SCImago Journal & Rank. The IJES has published 1055 articles in 79 issues in the first 15 years. The top 106 (10%) cited articles received a total of 7,195 citations according to GS. Top-cited IJES articles had median citations and citation rates (CR) of 48 citations and 6.5 citations/per year, respectively over a median of 8 years since their publication. Most top-cited articles were original research (68%) and reviews (9%). Top-cited articles were most often on Fitness Assessment (28%) and Technology, Epidemiology, and Physical Activity (15%) topics. In addition to its mission to support scholarly expertise of students, IJES is consistently indexed in GS with CR to top 5% cited articles similar to many journals in kinesiology/exercise science and higher than professional and highly specialized journals. The most cited articles have been in the areas of Fitness Assessment, Biomechanics and Neural Control, and Cardiovascular and Pulmonary Physiology. The IJES makes influential contributions to subsequent research in kinesiology, exercise science, and health, primarily through highly cited original research and review articles

    Examination of Winter Wheat Yield Response to Seed Source

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154489/1/pag2jpa19900551.pd

    Reflections on Professor Lee

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    Integration of ancient DNA with transdisciplinary dataset finds strong support for Inca resettlement in the south Peruvian coast

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    Ancient DNA (aDNA) analysis provides a powerful means of investigating human migration, social organization, and a plethora of other crucial questions about humanity’s past. Recently, specialists have suggested that the ideal research design involving aDNA would include multiple independent lines of evidence. In this paper, we adopt a transdisciplinary approach integrating aDNA with archaeological, biogeochemical, and historical data to investigate six individuals found in two cemeteries that date to the Late Horizon (1400 to 1532 CE) and Colonial (1532 to 1825 CE) periods in the Chincha Valley of southern Peru. Genomic analyses indicate that these individuals are genetically most similar to ancient and present-day populations from the north Peruvian coast located several hundred kilometers away. These genomic data are consistent with 16th century written records as well as ceramic, textile, and isotopic data. These results provide some of the strongest evidence yet of state-sponsored resettlement in the pre-Colonial Andes. This study highlights the power of transdisciplinary research designs when using aDNA data and sets a methodological standard for investigating ancient mobility in complex societies

    Geometry and Topology of Escape. II. Homotopic Lobe Dynamics

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    We continue our study of the fractal structure of escape-time plots for chaotic maps. In the preceding paper, we showed that the escape-time plot contains regular sequences of successive escape segments, called epistrophes, which converge geometrically upon each end point of every escape segment. In the present paper, we use topological techniques to: (1) show that there exists a minimal required set of escape segments within the escape-time plot; (2) develop an algorithm which computes this minimal set; (3) show that the minimal set eventually displays a recursive structure governed by an “Epistrophe Start Rule:” a new epistrophe is spawned Δ=D+1 role= presentation style= display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3eΔ=D+1Δ=D+1 iterates after the segment to which it converges, where D role= presentation style= display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3eD is the minimum delay time of the complex
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