1,252 research outputs found
Superquadric Library, User Manual and Utility Programs
Superquadrics are a family of parametric shapes that have been used as primitives for shape representation in computer vision and computer graphics. They can be used for modeling tapering and bending deformations and are recovered efficiently by a stable numerical procedure. This document introduces the superquadric library, SQ_lib, developed at the GRASP Lab at the University of Pennsylvania. The manual is organized into three parts. The first part provides the reader with a description of superquadrics models and deformations that can be performed. Furthermore, it introduces the coordinate systems conventions which are used in the library. The second part presents some examples of applications on how one can use the functions defined in the library. It also lists utility programs which have been developed while conducting research. They provide a good source of examples for the application of the library. Finally, the last part describes the datatypes and each of the functions which are supported in the library. The library itself is organized in two sets Fundamental and Auxiliary functions. A quick reference to all the functions and an index is provided. Some of the functions and examples supplied perform data preprocessing and are connected to the PM image description also available from the GRASP Lab. These functions are provided in isolation from the remaining body of the library and can easily be excluded in the actual compilation of the library. Furthermore, routines for the visualization of the data, using X11, are also provided
La Biblia como herramienta de gestación del mundo plástico de Joan Miró
Resumen:Joan Miró expresa, a lo largo de toda su producción artística, un gran interés hacia lo que puede constituir un enriquecimiento para su espíritu. Esta atracción, testimoniada por sus fuentes de inspiración iconográficas y literarias, se refleja en su lenguaje plástico. Guiados por las palabras del artista y los datos de investigación inéditos, se ha podido documentar el uso que hizo Miró de un texto bíblico en concreto, seleccionado entre los ejemplares de su biblioteca personal, que se convirtió en instrumento de influencia en su arte. Se ha demostrado como el vínculo íntimo de Miró con un grabado de Gustavo Doré (1832-1883), en el volumen II de la Sagrada Biblia familiar, editada en 1873, contribuyó a moldear el proceso de elaboración de la obra e inspirar los resultados iconográficos y formales de una serie de pinturas.Resum:La Bíblia com a eina de gestació del món plàstic de Joan MiróJoan Miró expressa, durant tota la seva producció artística, un gran interès cap al que pot constituir un enriquiment per al seu esperit. Aquesta atracció, testimoniada per les seves fonts d’inspiració iconogràfica i literàries, es reflexa en el seu llenguatge plàstic. Guiats per les paraules del artista i les dades d’investigació inèdites, s’ha pogut documentar l’ús que va fer Miró d’un text bíblic en concret, seleccionat entre els exemplars de la seva biblioteca personal, que es va convertir en instrument d’influència en el seu art. S’ha demostrat com el vincle íntim de Miró amb un gravat de Gustave Doré, en el volum II de la Sagrada Bíblia familiar, editada en 1873, va contribuir a modelar el procés d’elaboració de l’obra i inspirar els resultats iconogràfics i formals d’una sèrie de pintures.Abstract:The Bible as a tool of gestation in the plastic world of Joan MiróThroughout the whole period of his artistic production, Joan Miró expressed a deep interest in what could enrich his spirituality. This attraction, evidence of which is offered by his iconographic and literary sources of inspiration, is reflected in his plastic language and in his symbolism. Guided by the words of the artist and some unprecedented research information, we have been able to document the use Miró made of a specific text of the Bible, selected among his personal collection, which became an instrument of influence in his art. It has been proved how the intimate link of Miró with an etching of Gustavo Doré (1832-1883), in the second volume of the family version of the Holy Bible, dated 1873, contributed to give shape to this process of elaboration of the work of art and to inspire the iconographic and formal results of a series of painting
El museo oculto: la génesis del simbolismo mironiano en los archivos de la Fundació Joan Miró de Barcelona
Resumen:En este artículo se analiza la producción gráfica de Joan Miró conservada en los archivos de la homónima fundación de Barcelona. La colección de dibujos constituye un verdadero tesoro oculto y en parte inédito, tanto para el estudioso del arte mironiano como para el apasionado de su obra. El estudio de estas fuentes documentales ha constituido un punto de partida fundamental para investigar diferentes aspectos del arte de Joan Miró como la formación de su simbolismo, la evolución de su lenguaje y las temáticas abarcadas por el artista como la poesía y la política.Resum:El museu ocult: la gènesi del simbolisme mironià en els arxius de la Fundació Joan Miró de BarcelonaEn aquest article s’analitza la producció gràfica de Joan Miró conservada als arxius de l’homònima fundació de Barcelona. Es tracta d’un veritable tresor ocult i parcialment inèdit, tant per a l’estudiós de l’art mironià com per a l’apassionat de la seva obra. L’estudi d’aquestes fonts documentals constitueix un punt de partida fonamental per investigar diferents aspectes de l’art de Joan Miró com la formació del seu simbolisme, l’evolució del seu llenguatge o les temàtiques tractades per l’artista com la poesia i la política.Abstract:The hidden museum: the origins of mironian symbolism in the archive of Joan Miró Foundation in Barcelona.This article analyzes the graphic work of Joan Miró preserved in the archives of the eponymous foundation in Barcelona. The collection of drawings is a real hidden treasure, and partly unpublished, both for the student of Miró’s art and for those passionate about his work. The study of these documentary sources has been a fundamental point of departure for examining different aspects of the art of Joan Miró and the constitution of its symbolism, the evolution of language and the topics covered by the artist, such as poetry and politics
Modelo de simulação econômica em pequenas empresas estudo de caso
TCC (graduação) - Universidade Federal de Santa Catarina. Centro Sócio-Econômico. Economia.O presente trabalho tem por objetivo estudar fundamentos e métodos para elaborar uma ferramenta simples que possa oferecer subsídios mais qualificados no momento da tomada de decisão de investimento nas empresas. Neste contexto o trabalho aborda os conceitos básicos da decisão, as variáveis envolvidas no processo e um dos modelos tradicionais utilizados para gerar dados com base em simulação determinística, para então construir um modelo de simulação probabilística, com base nos conceitos de simulação do modelo de Monte Carlo. Como resultado tangível do trabalho foi construída uma planilha que permitiu efetuar simulações empíricas que validaram o resultado obtido pelos métodos determinístico e probabilístico, permitindo uma melhor análise dos dados disponíveis no momento da tomada de decisão de investimento
Effetti dell'eterogeneit\ue0 della piana alluvionale sulla migrazione di meandri fluviali
Le piane alluvionali e i relativi fiumi costituiscono complessi sistemi dinamici che coinvolgono processi idrodinamici, morfodinamici, geologici, geomorfologici, chimici e biologici agenti su un vasto intervallo di scale temporali (dai giorni ai secoli), con reciproche interazioni. La morfologia superficiale e la stratigrafia di una piana alluvionale sono modellate dalla mutua interazione di portata liquida, portata solida, processi di erosione e di deposito (Howard, 1996). L\u2019effetto a lungo termine \ue8 controllato dalla configurazione morfologica del fiume (meandriforme, intrecciato, anastomizzato), dal regime fluviale e dalle peculiarit\ue0 del trasporto solido. Confinamenti della piana alluvionale, la meccanica delle faglie e la distribuzione di biomassa possono inoltre assumere un ruolo apprezzabile nel determinare l\u2019evoluzione della piana alluvionale.
L\u2019obiettivo del presente lavoro \ue8 analizzare un particolare aspetto della dinamica fiume-piana alluvionale: il ruolo dell\u2019eterogeneit\ue0 della superficie alluvionale nel determinare la configurazione spaziale di un fiume meandriforme la cui dinamica, a sua volta, contribuisce a formare la struttura sedimentologica della piana alluvionale stessa. Questa interazione mutua \ue8 strettamente correlata alla formazione di oxbow lakes e scroll bars (Figura 1), i quali introducono modificazioni nella superficie della piana alluvionale e, pertanto, influiscono sull\u2019evoluzione morfologica dei meandri (Lazarus & Constantine, 2013). Gli oxbow lakes rappresentano recipienti naturali per l\u2019immagazzinamento di sedimenti e producono singolarit\ue0 morfologiche, ecosistemi locali, serbatoi di idrocarburi ed inquinanti (Lewin and Ashworth, 2014). D\u2019altra parte, la continua formazione di cutoffs, con la conseguente rimozione dei lobi di meandri pienamente sviluppati e la creazione di nuovi oxbow lakes, introduce un limite nello sviluppo della complessit\ue0 geometrica del fiume e, di conseguenza, assicura una condizione di evoluzione stabile dal punto di vista statistico (Camporeale et al, 2005; Frascati & Lanzoni, 2010).
Le unit\ue0 geomorfologiche formate da scroll bars e oxbow lakes assumono quindi un ruolo di primaria importanza sia nel passato del fiume, rappresentando un archivio della sua storia morfodinamica (Schwenk et al., 2015), sia per prevenire la sua evoluzione futura, operando come filtro sullo sviluppo planimetrico a breve e lungo termine
Characterization of Functionality in a Dynamic Environment
Identifying the functionality in objects means to be able to associate a purpose with them in a specific environment. The purpose depends on the intention of the agent and on the applicability of the object in a particular task. In our investigation of functionality we focus on functionalities which involve changes of physical relation and properties between objects in the environment. A formal model, based on Discrete Event Dynamic System Theory (DEDS), is introduced to define an interactive task for recovering and describing functionality. To observe and control the recovery process we introduce the notion of piecewise observability of a task by different sensors. This allows the description of a dynamic system in which neither all events nor the time of their occurrence may be predicted in advance. We have developed an experimental system consisting of actuators and both force and position sensors, for carrying out the interactive recovery of functionality. In particular, we demonstrate how this approach can be used by carrying out some experiments investigating the functionality of piercing. Furthermore, we discuss the importance of a multisensory approach for the observation and interpretation of functionality
An Active Approach to Functionality Characterization and Recognition
In this paper we focus on understanding and defining a methodology for object description and recognition both in terms of its geometrical, material and functional specifications. We define functionality in an object as its applicability toward the achievement of a task. We emphasize and develop an interactive and performatory approach to functionality recovery. Furthermore, we introduce the distinction between Inherent, Intended and Imposed functionality.
By analyzing interaction and manipulation tasks as goal-oriented recognition processes we propose to identify and characterize functionalities of objects. This interaction is not only a means of verification of the hypothesized presence of functionality in objects but also a way to actively and purposively recognize the object.
In order to accomplish our goal, we introduce a formal model, based on Discrete Event Dynamic System Theory, to define a task for recovering and describing functionality. We extend the recovery process to an algebra of tasks. We describe how a more complex task call be composed from a set of primitive ones. This constructive approach allows a task to be built from simpler ones in an stepwise fashion.
Once the manipulatory task has been described in the formal model, it must be instantiated in a context. In such a context, the behavior of the system in which the interactio between a Manipulator, a Tool and a Target object must be observed. Thus, the description of tasks themselves provide must for means of addressing observability through different sensor modalities. For this purpose, we introduce the notion of Partial Observability of a task. This allows the description of a plant in which not all events and the time of their occurrence might he modelled and therefore predictable in advance
An Active Approach to Characterization and Recognition of Functionality and Functional Properties
Functionality in an object can be defined as its applicability toward the accomplishment of a task. We emphasize and develop an interactive and performatory approach to functionality recovery from sensor data in the context of robotic manipulatory tasks. By analyzing interaction of tool and target object and manipulation tasks as goal-oriented recognition processes, we propose to identify and characterize functionalities of objects. This interaction is not only a means of verification of the hypothesized presence of functionality in objects but also a way to actively and purposively recognize the object. The representation of functionality allows us to extend the recovery process to a hierarchy of functionalities allowing complex ones to be composed from simpler ones.
A formal model, based on Discrete Event Dynamic System Theory (DEDS), is introduced to define an interactive task for recovering and describing functionality. To observe and control the recovery process we introduce the notion of piecewise observability of a task by different sensors. This allows the description of a dynamic system in which not all events nor the time of their occurrence may be predicted in advance. An experimental system, with both vision and force sensors, for carrying out the interactive functional recognition is described
A Preliminary LCA Analysis of Snowmaking in Fiemme Valley
Modern ski resorts have been using systems of technical snow for many years: initially they were used to compensate the limits of natural snow but today it is actually the natural snow that
is used as an integration to artificial snow and not vice versa. This paper aims to identify and evaluate the environmental impacts associated to the production of artificial snow, comparing
two very different winter seasons in terms of snowfalls. The results of LCA analysis shows that the production of artificial snow primarily implies impacts on natural land transformation and
fossil depletion, and that more snowfalls cause more onerous skiing resorts management, due to high consumption of diesel fuel for piste machines used for snow grooming
Quantitative and Qualitative Measures for the Evaluation of the Superquadric Models
In this paper we discuss the evaluation criteria for superquadric models recovered from the range data. We present arguments to support our belief that both quantitative and qualitative measures are required in order to evaluate a superquadric fit. The concept of superquadric contraction and dilation is introduced and used to derive a novel interpretation of the modified superquadric inside-outside function in terms of contraction/expansion factor. The same concept also gives a close initial guess for the numerical procedure computing the minimum Euclidean distance of a point from a superquadric model. The minimum Euclidean distance map is introduced as a qualitative criterion for interpretation of fit. View-dependent qualitative measures like the contour-difference map and the z-distance map are shown to be essential for the complete evaluation of the models. Analytical solution and techniques for the contour generator on superquadric models are presented. Finally, examples of real objects are given to generate the measures
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