12,046 research outputs found

    A note on two notions of compliance

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    We establish a relation between two models of contracts: binary session types, and a model based on event structures and game-theoretic notions. In particular, we show that compliance in session types corresponds to the existence of certain winning strategies in game-based contracts.Comment: In Proceedings ICE 2014, arXiv:1410.701

    Dependencies and Simultaneity in Membrane Systems

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    Membrane system computations proceed in a synchronous fashion: at each step all the applicable rules are actually applied. Hence each step depends on the previous one. This coarse view can be refined by looking at the dependencies among rule occurrences, by recording, for an object, which was the a rule that produced it and subsequently (in a later step), which was the a rule that consumed it. In this paper we propose a way to look also at the other main ingredient in membrane system computations, namely the simultaneity in the rule applications. This is achieved using zero-safe nets that allows to synchronize transitions, i.e., rule occurrences. Zero-safe nets can be unfolded into occurrence nets in a classical way, and to this unfolding an event structure can be associated. The capability of capturing simultaneity of zero-safe nets is transferred on the level of event structure by adding a way to express which events occur simultaneously

    Measurement of deformation gradients in hot rolling of AA3004

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    In this paper we describe an experimental technique developed to measure the deformation gradients and temperature in a single hot rolling pass of an AA3004 sample that was fitted with an insert. The insert had been previously hand engraved with a 1 × 1 mm grid pitch, and the analysis of the data digitally captured from the image of the deformed grid enabled the calculation of the components of the deformation gradient tensor. Four steel pins prevented relative motion between the insert and the rest of the sample. No detachment was observed between insert and sample after rolling. The temperature was measured during rolling using two embedded thermocouples, one close to the surface and the other in the centerline. The commercial finite element code ABAQUS was used to create a three-dimensional model of the rolling process. The recorded temperature was compared to the numerical values evaluated after tuning the heat transfer coefficient. The shape of the grid after rolling was checked against the deformed mesh using different friction coefficients in order to obtain the optimum match. The unusually large length of the insert enabled the rolling process to be stopped halfway so that a picture of the roll-gap area could be obtained. This provided a partially deformed grid that represented the transient state during rolling. The experimentally determined deformation gradient in this area as well as in the steady-state area agreed well with the finite element predictions. © 2005 Society for Experimental Mechanics

    Effect of different pastures on CLA content in milk and sheep cheese

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    It is known that milk composition included conjugated linoleic acid (CLA) is affected by animal feeding system (Cabiddu et al., 2001). In Sardinia dairy sheep feeding is mainly based on pastures. Most of them are characterised by self-regenerating species, like annual ryegrass (Lolium rigidum Gaudin) and burr medic (Medicago polymorpha L.). Non conventional species belonging to the Compositae family such as (Chrysanthemum coronarium L.) seem interesting for sheep feeding when other herbages decrease in quality (late spring- early summer). It was observed that C. coronarium establishes rapidly, can be grazed early in the growing season and persist where other pasture species may disappear; for these reasons it can be considered a valuable source of food. Moreover a preliminary study with dairy sheep fed fresh forage of C. coronarium showed relatively high levels of CLA in milk (Molle G. pers. com.) The aim of the present work was to study the influence of different pastures on milk composition, with particular reference to CLA and its precursors

    La Meccanizzazione della raccolta del mirto

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    The plant of the myrtle in past has been always considered one marginal cultivation and of insufficient interest. Only in the last five years it has been knowledge the economic importance for the demanded crescent of liquor of myrtle, product up to now nearly exclusively in Sardinia. Therefore, new sensibility has been developed one and a greater knowledge of the importance of a deepened study more of the cultivation from the biological point of view and the point of view of one rations mechanized harvester of the berries. The aim of the work was that one to characterize an harvester of the berries from the plant, avoiding the damaging of the plant and above all of the fruits that influenced on the quality of the finished product. In this present study they are evidences the comparison between some tests of harvest in turn to obtained and carried out with two different types of harvesters some in relation to the ransom of the plants

    Possible routes of animal exposure to cadmium and cadmium compounds and induced effects: a review

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    A retrospective analysis about cadmium and cadmium compounds teratogenicity, toxicity and carcinogenicity was carried out on literature basis, up to date, reviewed according to animal species, routes of exposure, acute and chronic response to different dosages via gastrointestinal or inhalatory uptake, target organs and apparatus. Some recent updates from experimental trials were also comparatively considered

    Phase shifts of synchronized oscillators and the systolic/diastolic blood pressure relation

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    We study the phase-synchronization properties of systolic and diastolic arterial pressure in healthy subjects. We find that delays in the oscillatory components of the time series depend on the frequency bands that are considered, in particular we find a change of sign in the phase shift going from the Very Low Frequency band to the High Frequency band. This behavior should reflect a collective behavior of a system of nonlinear interacting elementary oscillators. We prove that some models describing such systems, e.g. the Winfree and the Kuramoto models offer a clue to this phenomenon. For these theoretical models there is a linear relationship between phase shifts and the difference of natural frequencies of oscillators and a change of sign in the phase shift naturally emerges.Comment: 8 figures, 9 page

    Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

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    In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred
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