335 research outputs found

    Time indeterminacy and spatio-temporal building transformations: an approach for architectural heritage understanding

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    Nowadays most digital reconstructions in architecture and archeology describe buildings heritage as awhole of static and unchangeable entities. However, historical sites can have a rich and complex history, sometimes full of evolutions, sometimes only partially known by means of documentary sources. Various aspects condition the analysis and the interpretation of cultural heritage. First of all, buildings are not inexorably constant in time: creation, destruction, union, division, annexation, partial demolition and change of function are the transformations that buildings can undergo over time. Moreover, other factors sometimes contradictory can condition the knowledge about an historical site, such as historical sources and uncertainty. On one hand, historical documentation concerning past states can be heterogeneous, dubious, incomplete and even contradictory. On the other hand, uncertainty is prevalent in cultural heritage in various forms: sometimes it is impossible to define the dating period, sometimes the building original shape or yet its spatial position. This paper proposes amodeling approach of the geometrical representation of buildings, taking into account the kind of transformations and the notion of temporal indetermination

    A semantic-based platform for the digital analysis of architectural heritage

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    This essay focuses on the fields of architectural documentation and digital representation. We present a research paper concerning the development of an information system at the scale of architecture, taking into account the relationships that can be established between the representation of buildings (shape, dimension, state of conservation, hypothetical restitution) and heterogeneous information about various fields (such as the technical, the documentary or still the historical one). The proposed approach aims to organize multiple representations (and associated information) around a semantic description model with the goal of defining a system for the multi-field analysis of buildings

    “Use of Scanner Data to Analyze the Table Wine Demand in the Italian Major Retailing Trade”

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    ABSTRACT While the utilization of scanner data for food demand analyses has become increasingly popular in the United States, few food demand studies, and in particular none on table wine, have been conducted using scanner data in Italy+ This paper presents a first attempt to estimate a demand system for selected brands of red tetra-packaged, plastic packaged, and bag-in-box table wine using scanner data providing new and useful insights into the marketing of Italian wine+ Price and expenditure elasticities of Italian red table wine demand drawn from a linear almost ideal demand system are provided+ Results suggest a partially loyal market of table wine, showing a tendency to substitution across brands and a degree of competition among the leading brands+ @EconLit citations: Q110, Q130#+ © 2006 Wiley Periodicals, Inc

    Time indeterminacy and spatio-temporal building transformations: an approach for architectural heritage understanding

    Get PDF
    Nowadays most digital reconstructions in architecture and archeology describe buildings heritage as awhole of static and unchangeable entities. However, historical sites can have a rich and complex history, sometimes full of evolutions, sometimes only partially known by means of documentary sources. Various aspects condition the analysis and the interpretation of cultural heritage. First of all, buildings are not inexorably constant in time: creation, destruction, union, division, annexation, partial demolition and change of function are the transformations that buildings can undergo over time. Moreover, other factors sometimes contradictory can condition the knowledge about an historical site, such as historical sources and uncertainty. On one hand, historical documentation concerning past states can be heterogeneous, dubious, incomplete and even contradictory. On the other hand, uncertainty is prevalent in cultural heritage in various forms: sometimes it is impossible to define the dating period, sometimes the building original shape or yet its spatial position. This paper proposes amodeling approach of the geometrical representation of buildings, taking into account the kind of transformations and the notion of temporal indetermination

    Existence and stability of weak solutions of the Vlasov--Poisson system in localized Yudovich spaces

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    We consider the Vlasov--Poisson system both in the repulsive (electrostatic potential) and in the attractive (gravitational potential) cases. In our first main theorem, we prove the uniqueness and the quantitative stability of Lagrangian solutions f=f(t,x,v)f=f(t,x,v) whose associated spatial density ρf=ρf(t,x)\rho_f=\rho_f(t,x) is potentially unbounded but belongs to suitable uniformly-localized Yudovich spaces. This requirement imposes a condition of slow growth on the function pρf(t,)Lpp \mapsto \|\rho_f(t,\cdot)\|_{L^p} uniformly in time. Previous works by Loeper, Miot and Holding--Miot have addressed the cases of bounded spatial density, i.e., ρf(t,)Lp1\|\rho_f(t,\cdot)\|_{L^p} \lesssim 1, and spatial density such that ρf(t,)Lpp1/α\|\rho_f(t,\cdot)\|_{L^p} \sim p^{1/\alpha} for α[1,+)\alpha\in[1,+\infty). Our approach is Lagrangian and relies on an explicit estimate of the modulus of continuity of the electric field and on a second-order Osgood lemma. It also allows for iterated-logarithmic perturbations of the linear growth condition. In our second main theorem, we complement the aforementioned result by constructing solutions whose spatial density sharply satisfies such iterated-logarithmic growth. Our approach relies on real-variable techniques and extends the strategy developed for the Euler equations by the first and fourth-named authors. It also allows for the treatment of more general equations that share the same structure as the Vlasov--Poisson system. Notably, the uniqueness result and the stability estimates hold for both the classical and the relativistic Vlasov--Poisson systems

    Existence and stability of weak solutions of the Vlasov-Poisson system in localized Yudovich spaces

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    We consider the Vlasov-Poisson system both in the repulsive (electrostatic potential) and in the attractive (gravitational potential) cases. In our first main theorem, we prove the uniqueness and the quantitative stability of Lagrangian solutions f=f(t,x,v)f=f(t,x,v) whose associated spatial density ρf=ρf(t,x)\rho_f=\rho_f(t,x) is potentially unbounded but belongs to suitable uniformly-localized Yudovich spaces. This requirement imposes a condition of slow growth on the function pρf(t,)Lpp \mapsto \|\rho_f(t,\cdot)\|_{L^p} uniformly in time. Previous works by Loeper, Miot and Holding--Miot have addressed the cases of bounded spatial density, i.e., ρf(t,)Lp1\|\rho_f(t,\cdot)\|_{L^p} \lesssim 1, and spatial density such that ρf(t,)Lpp1/α\|\rho_f(t,\cdot)\|_{L^p} \sim p^{1/\alpha} for α[1,+)\alpha\in[1,+\infty). Our approach is Lagrangian and relies on an explicit estimate of the modulus of continuity of the electric field and on a second-order Osgood lemma. It also allows for iterated-logarithmic perturbations of the linear growth condition. In our second main theorem, we complement the aforementioned result by constructing solutions whose spatial density sharply satisfies such iterated-logarithmic growth. Our approach relies on real-variable techniques and extends the strategy developed for the Euler equations by the first and fourth-named authors. It also allows for the treatment of more general equations that share the same structure as the Vlasov-Poisson system. Notably, the uniqueness result and the stability estimates hold for both the classical and the relativistic Vlasov-Poisson systems

    Review of the “ as-buit BIM ” approaches

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    International audienceToday, we need 3D models of heritage buildings in order to handle more efficiently projects of restoration, documentation and maintenance. In this context, developing a performing approach, based on a first phase of building survey, is a necessary step in order to build a semantically enriched digital model. For this purpose, the Building Information Modeling is an efficient tool for storing and exchanging knowledge about buildings. In order to create such a model, there are three fundamental steps: acquisition, segmentation and modeling. For these reasons, it is essential to understand and analyze this entire chain that leads to a well- structured and enriched 3D digital model. This paper proposes a survey and an analysis of the existing approaches on these topics and tries to define a new approach of semantic structuring taking into account the complexity of this chain

    A Tool for the 3D Spatio-Temporal Structuring of Historic Building Reconstructions

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    The difficulty in the description, the analysis and the comprehension of cultural heritage often stands on the fact that buildings undergo numerous changes over time. Three factors condition the knowledge of historical heritage. Firstly, 3D reconstructions of heritage buildings focus normally on existing states and not on the management of historical evolutions. Secondly, if on one side iconographic sources are generally used like visual memory of a building temporal state to be restored graphically, on the other side few works today focus on the use of all metric and visual information contained in sources. At last, iconographic documentation concerning building past states is sometimes contradictory, dubious and incomplete. As a consequence, in 3D reconstructions uncertainties, contradictions and gaps in information should be highlighted. We present a methodological approach basing on the existing iconographic corpus for the analysis and the 3D management of building transformations. This approach joins three main aspects in a complete workflow. Firstly, it concerns the spatial and temporal referencing of 2D iconographic sources for the 3D reconstruction of disappeared building states. Secondly, it allows the analysis of building transformations by means of a temporal state distribution. Lastly, it uses spatial relations established between 2D iconography and 3D representation for the visual browsing of information based on spatiotemporal criteria. In particular, in this paper we detail the interface developed in order to accomplish multiple related tasks concerning the spatio-temporal structuring of the morphology to be reconstructed

    Use of Scanner Data to Analyze the Table Wine Demand in the Italian Major Retailing Trade

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    ABSTRACT While the utilization of scanner data for food demand analyses has become increasingly popular in the United States, few food demand studies, and in particular none on table wine, have been conducted using scanner data in Italy+ This paper presents a first attempt to estimate a demand system for selected brands of red tetra-packaged, plastic packaged, and bag-in-box table wine using scanner data providing new and useful insights into the marketing of Italian wine+ Price and expenditure elasticities of Italian red table wine demand drawn from a linear almost ideal demand system are provided+ Results suggest a partially loyal market of table wine, showing a tendency to substitution across brands and a degree of competition among the leading brands+ @EconLit citations: Q110, Q130#
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