1,016 research outputs found

    Proofs Versus Experiments: Wittgensteinian Themes Surrounding the Four-Color Theorem

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    The Four-Colour Theorem (4CT) proof, presented to the mathematical community in a pair of papers by Appel and Haken in the late 1970's, provoked a series of philosophical debates. Many conceptual points of these disputes still require some elucidation. After a brief presentation of the main ideas of Appel and Haken’s procedure for the proof and a reconstruction of Thomas Tymoczko’s argument for the novelty of 4CT’s proof, we shall formulate some questions regarding the connections between the points raised by Tymoczko and some Wittgensteinian topics in the philosophy of mathematics such as the importance of the surveyability as a criterion for distinguishing mathematical proofs from empirical experiments. Our aim is to show that the “characteristic Wittgensteinian invention” (Mühlhölzer 2006) – the strong distinction between proofs and experiments – can shed some light in the conceptual confusions surrounding the Four-Colour Theorem

    Municipal transitions: The social, energy, and spatial dynamics of sociotechnical change in South Tyrol, Italy

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    With the aim of proposing recommendations on how to use social and territorial specificities as levers for wider achievement of climate and energy targets at local level, this research analyses territories as sociotechnical systems. Defining the territory as a sociotechnical system allows us to underline the interrelations between space, energy and society. Groups of municipalities in a region can be identified with respect to their potential production of renewable energy by means of well-known data-mining approaches. Similar municipalities linking together can share ideas and promote collaborations, supporting clever social planning in the transition towards a new energy system. The methodology is applied to the South Tyrol case study (Italy). Results show eight different spatially-based sociotechnical systems within the coherent cultural and institutional context of South Tyrol. In particular, this paper observes eight different systems in terms of (1) different renewable energy source preferences in semi-urban and rural contexts; (2) different links with other local planning, management, and policy needs; (3) different socio-demographic specificities of individuals and families; (4) presence of different kinds of stakeholders or of (5) different socio-spatial organizations based on land cover. Each energy system has its own specificities and potentialities, including social and spatial dimensions, that can address a more balanced, inclusive, equal, and accelerated energy transition at the local and translocal scale

    Marble Architectural Elements and Liturgical Furniture of the Santa Giustina Basilica in Padova : New Archaeometric Data on the Importation of Proconnesian Marble in the Late Antique Adriatic

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    This paper examines eight marble samples from the architectural elements and liturgical furniture of the ecclesiastical complex of Santa Giustina in Padova (Italy), founded by the Rufus Venantius Opilio before AD 524. The provenance determination of the marbles was carried out by means of a multi-analytical approach combining mineralogical-petrographic investigations, performed by microscopic observations of thin sections, and the measurement of the ratios of stable carbon and oxygen isotopes. The results obtained were compared with up-to-date petrographic and isotopic databases (Antonelli and Lazzarini 2015), and they showed that the analyzed marbles come from the quarries of the island of Proconnesus in Asia Minor, modern Marmara Adasi (Turkey). Archaeometric evidence, together with the stylistic and functional analysis of the pieces, suggests the direct importation of a complete set of sculptures, shipped at different stages of workmanship from the workshops of Constantinople and expressly ordered by a single patron, who can be identified as Opilio, founder of the basilica of Santa Giustina and praetorian prefect at the court of King Theodoric

    An Activity Classifier based on Heart Rate and Accelerometer Data Fusion

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    The European project ProeTEX realized a novel set of prototypes based on smart garments that integrate sensors for the real-time monitoring of physiological, activity-related and environmental parameters of the emergency operators during their interventions. The availability of these parameters and the emergency scenario suggest the implementation of novel classification methods aimed at detecting dangerous status of the rescuer automatically, and based not only on the classical activityrelated signals, rather on a combination of these data with the physiological status of the subject. Here we propose a heart rate and accelerometer data fusion algorithm for the activity classification of rescuers in the emergency context

    EXPO-AGRI: Smart Automatic Greenhouse Control

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    Predicting and controlling plant behavior in con- trolled environments is a growing requirement in precision agri- culture. In this context sensor networks and artificial intelligence methods represent key aspects for optimizing the processes of data acquisition, mathematical modeling and decision making. In this paper we present a general architecture for automatic greenhouse control. In particular, we focus on a preliminary model for predicting the risk of new infections of downy mildew of basil (Peronospora belbahrii) on sweet basil. The architecture has three main elements of innovation: new kinds of sensors are used to extract information about the state of the plants, model predictors are generated from this information by non-trivial processing methods, and informative predictors are automatically selected using regularization techniques

    High-pressure synthesis, crystal and electronic structures of a new scandium tungstate, Sc0.67WO4

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    Negative thermal expansion (NTE) materials possess a low-density, open structure which can respond to high pressure conditions, leading to new compounds and/or different physical properties. Here we report that one such NTE material -- white, insulating, orthorhombic Sc2W3O12 -- transforms into a black compound when treated at 4 GPa and 1400 oC. The high pressure phase, Sc0.67WO4, crystallizes in a defect-rich wolframite-type structure, a dense, monoclinic structure (space group P2/c) containing 1-D chains of edge-sharing WO6 octahedra. The chemical bonding of Sc0.67WO4 vis-a-vis the ambient pressure Sc2W3O12 phase can be understood on the basis of the Sc defect structure. Magnetic susceptibility, resistivity, thermoelectric power and IR spectroscopic measurements reveal that Sc0.67WO4 is a paramagnet whose conductivity is that of a metal in the presence of weak localization and electron-electron interactions. Oxygen vacancies are suggested as a potential mechanism for generating the carriers in this defective wolframite material.Comment: 29 pages total, 1 table, 7 figure
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