10,590 research outputs found

    Infinitely many cyclic solutions to the Hamilton-Waterloo problem with odd length cycles

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    It is conjectured that for every pair (ℓ,m)(\ell,m) of odd integers greater than 2 with m≡1  (modℓ)m \equiv 1\; \pmod{\ell}, there exists a cyclic two-factorization of KℓmK_{\ell m} having exactly (m−1)/2(m-1)/2 factors of type ℓm\ell^m and all the others of type mℓm^{\ell}. The authors prove the conjecture in the affirmative when ℓ≡1  (mod4)\ell \equiv 1\; \pmod{4} and m≥ℓ2−ℓ+1m \geq \ell^2 -\ell + 1.Comment: 31 page

    Detection of variations in aspen forest habitat from LANDSAT digital data: Bear River Range, Utah

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    The aspen forests of the Bear River Range were analyzed and mapped using data recorded on July 2, 1979 by the LANDSAT III satellite; study efforts yielded sixty-seven light signatures for the study area, of which three groups were identified as aspen and mapped at a scale of 1:24,000. Analysis and verification of the three groups were accomplished by random location of twenty-six field study plots within the LANDSAT-defined aspen areas. All study plots are included within the Cache portion of the Wasatch-Cache National Forest. The following selected site characteristics were recorded for each study plot: a list of understory species present; average percent cover density for understory species; aspen canopy cover estimates and stem measurements; and general site topographic characteristics. The study plot data were then analyzed with respect to corresponding Landsat spectral signatures. Field studies show that all twenty-six study plots are associated with one of the three aspen groups. Further study efforts concentration on characterizing the differences between the site characteristics of plots falling into each of the three aspen groups

    KoKoo (Kontent Kooration) Evolving a Content Curation System To a comprehensive Editorial backend platform

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    The aim of this paper is to show how a prototypal system, designed as a general purpose stand-alone content curation tool could be evolved by following some alpha user's feedbacks to an comprehensive multi-service platform. The widespread diffusion of mobile devices, such as smartphones and tablets as long as the availability of mobile wideband services are increasing day by day the number of players in the ICT Market. In such a scenario, following the user needs becomes a critical issue, since it is likely for the users. to find products and services quite similar to the one you are offering, better fulfilling their needs. KOKOO (KOntent + KOO(Ù)ration) is a comprehensive platform made by Telecom Italia R&D division. It is a solution for solving the growing content provider needs to find new and most interesting news to offer to other users on different media, aggregating them in a personal journal with a similar look and feel. Chapter 2 will show the old system (presented also at Nem Summit 2012 showcase), chapter 3 will present user feedbacks and chapter 4 will show the new system and all of its aggregated services, stressing how this was designed by following user feedback

    Geometry of contours and Peierls estimates in d=1 Ising models

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    Following Fr\"ohlich and Spencer, we study one dimensional Ising spin systems with ferromagnetic, long range interactions which decay as ∣x−y∣−2+α|x-y|^{-2+\alpha}, 0≤α≤1/20\leq \alpha\leq 1/2. We introduce a geometric description of the spin configurations in terms of triangles which play the role of contours and for which we establish Peierls bounds. This in particular yields a direct proof of the well known result by Dyson about phase transitions at low temperatures.Comment: 28 pages, 3 figure

    On the instability and constraints of the interaction between number representation and spatial attention in healthy humans. A concise review of the literature and new experimental evidence

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    .The relationship between number and space representation is still one of the most debated topics in studies of mathematical cognition. Here we offer a concise review of two important behavioral effects that have pointed out the use of a spatially left-to-right oriented mental number line (MNL) in healthy participants: the SNARC effect and the attentional SNARC effect (Att-SNARC). Following a brief summary of seminal investigations on the introspective properties of the MNL, we review recent empirical evidence and theories on the functional origin of the SNARC effect, where upon left/right response choices faster reaction times are found for small numbers with left-side responses and for large numbers with right-side responses. Then we offer a summary of the studies that have investigated whether the mere perception of visual Arabic numbers presented at central fixation can engender spatially congruent lateral shifts of attention, ie, leftward for small numbers and rightward for large ones, ie, the Att-SNARC effect. Finally, we summarize four experiments that tested whether the Att-SNARC depends on an active rather than passive processing of centrally presented digit cues. In line with other recent studies, these experiment do not replicate the original Att-SNARC and show that the mere perception of Arabic numerals does not trigger automatic shifts of attention. These shifts are instead found when the task requires the explicit left/right spatial coding of digit cues, ie, Spatial Att-SNARC (Fattorini et al., 2015b). Nonetheless, the reliability of the Spatial Att-SNARC effect seems not as strong as that of conventional SNARC effects where left/ right codes are mapped onto responses rather than directly mapped on digit cues. Comparing the magnitude of digits to a numerical reference, ie, "5," also produced a Magnitude Comparison Att-SNARC that was weaker than the spatial one. However, the reliability of this Magnitude Comparison Att-SNARC should be considered with caution because, like in a study by Zanolie and Pecher (2014), we recently failed to replicate this effect in a separate behavioral-eventrelated potentials study in preparation (Fattorini et al., 2015a). All together the results from the present series of experiments support the hypothesis that spatial coding is not an intrinsic part of number representation and that number-space interaction is determined by the use of stimulus-or response-related spatial codes in the task at han

    Catalytic fuel cell used as an analytical tool for methanol and ethanol determination. Application to ethanol determination in alcoholic beverages

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    A small direct catalytic methanol 'fuel cell' was used for analytical purposes. Three different formats were investigated for methanol and ethanol determination: two different Open Circuit Voltage (OCV) formats and a potentiostatic (i.e. amperometric) format; the latter was used if the current supplied by the cell was recorded. The measurement times using one or other of these three formats were much different. The time required by the potentiostatic format was more short for a suitable analytical measurement. The cell was used to check ethanol content in several commercial wine and beer samples and the possibility of using the fuel cell for the analytical measures in real samples, discussed. Lastly the results were compared with those obtained using two conventional amperometric enzyme sensors and statistical tests carried out. (C) 2016 Elsevier Ltd. All rights reserved
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