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Search Results: 1 - 10 of 126335 matches for " José Carlos;Costa "
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∫2. De Vegetatio Lusitana Notae - II.: 4. Halimiono portulacoidis -Salicornietum ramosissimae J.C. Costa in J.C. Costa, Lous & Espírito Santo 1996, nome corrigido
José Carlos Costa
Silva Lusitana , 2004,
Canonical forms for free κ-semigroups
José Carlos Costa
Mathematics , 2013,
Abstract: The implicit signature k consists of the multiplication and the ({\omega}-1)-power. We describe a procedure to transform each {\kappa}-term over a finite alphabet A into a certain canonical form and show that different canonical forms have different interpretations over some finite semigroup. The procedure of construction of the canonical forms, which is inspired in McCammond's normal form algorithm for {\omega}-terms interpreted over the pseudovariety A of all finite aperiodic semigroups, consists in applying elementary changes determined by an elementary set {\Sigma} of pseudoidentities. As an application, we deduce that the variety of {\kappa}-semigroups generated by the pseudovariety S of all finite semigroups is defined by the set {\Sigma} and that the free {\kappa}-semigroup generated by the alphabet A in that variety has decidable word problem. Furthermore, we show that each {\omega}-term has a unique {\omega}-term in canonical form with the same value over A. In particular, the canonical forms provide new, simpler, representatives for {\omega}-terms interpreted over that pseudovariety.
A Cambrian Explosion of Robotic Life
Diogo Costa,José Carlos Cavalcanti,Dickson Costa
Management Science and Engineering , 2011,
Abstract: The main objective of this paper is to argue that we, as a civilization, are in the beginnings of a Cambrian Explosion of Robotic Life. In order to give support to this argument, we present a line of thought that begins with a very brief technical account of what has been so far the design and development of robots. Then, we assume that the emergence of recent disruptive technologies, such as Kinect, an information technology device developed by Microsoft Corporation, generated a simple and low cost solution to the problem of visual computing, turning the design and development of robots for simple applications barely a question of hardware construction and software development for control. As the design and development of robots for less complex applications do not need advanced computational intelligence, these tasks only require control commands that respond to real world stimuli; in other words, it is just a question of software design and development. For this reason, the design and development of robots have become a simple and common undertaking, which is giving birth to a global explosion of robotic life, a phenomena comparable to the Cambrian Explosion of Life which our planet experienced millions of years ago. Key words: Robots; Hardware; Software; Motion; Information technology; Computer vision; Kinect; Human machine interface (HMI); Emerging economies; Cambrian Explosion; Disruptive technologies
XXX: Notícia acerca dos carrascais arbóreos da Serra da Arrábida
Jorge Capelo,José Carlos Costa
Silva Lusitana , 2001,
?2. De Vegetatio Lusitana Notae - III.: 8. Comunidades vegetais dos solos arenosos podzolizados do Sado e Costa da Galé. Uma interpreta o fitossocio-lógica dos dados paleoecológicos e geomorfológicos
Carlos Neto,Jorge Capelo,José Carlos Costa
Silva Lusitana , 2004,
New Pedagogical Mediation Technologies in Accounting Education: A Discussion Based on Researches Published in the EnANPAD between 2005 and 2009  [PDF]
Vilma Geni Slomski, Liliane Costa Jacobs Lames, Edilei Rodrigues de Lames, José Carlos Marion
Creative Education (CE) , 2013, DOI: 10.4236/ce.2013.411103
Abstract: This study aimed to characterize and analyze researches on new technologies in accounting education published in the EnANPAD during the period from 2005 to 2009. Therefore, an exploratory-qualitative research was carried out. Data were collected through document analysis. The concern of emphasizing the importance of the use and acceptance of new technologies in accounting education was one of the findings in evaluating such researches; another finding was the predominance of quantitative-descriptive approach; followed by the technique of questionnaire application in the collection and in the statistical analysis of the collected data. Limitations were noted concerning the lack of a greater articulation between the research theme, problem and objectives, as well as the lack of a larger theoretical and methodological consistency. Such difficulties may have affected the results and conclusions. Our conclusion is that difficulties and limitations of epistemological order can impair the validity and importance of the researches, and likewise also impair more scientific progress and contributions to the field of the knowledge at issue.
Characteristics of the CsI:Tl Scintillator Crystal for X-Ray Imaging Applications  [PDF]
Maria da Concei??o Costa Pereira, Tufic Madi Filho, José Roberto Berretta, Carlos Henrique de Mesquita
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.92018
Abstract: Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10-3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.
McCammond's normal forms for free aperiodic semigroups revisited
Jorge Almeida,José Carlos Costa,Marc Zeitoun
Computer Science , 2014, DOI: 10.1112/S1461157014000448
Abstract: This paper revisits the solution of the word problem for $\omega$-terms interpreted over finite aperiodic semigroups, obtained by J. McCammond. The original proof of correctness of McCammond's algorithm, based on normal forms for such terms, uses McCammond's solution of the word problem for certain Burnside semigroups. In this paper, we establish a new, simpler, correctness proof of McCammond's algorithm, based on properties of certain regular languages associated with the normal forms. This method leads to new applications.
XXXIV: Aditamentos à vegeta o de Portugal continental
Carlos Aguiar,José Carlos Costa,Jorge Capelo,Anabela Amado
Silva Lusitana , 2003,
∫2. De Vegetatio Lusitana Notae - II: 6. As comunidades de Salix arenaria L. em Portugal
Carlos Neto,José Carlos Costa,Jorge Capelo,Jo?o Honrado
Silva Lusitana , 2004,
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