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Search Results: 1 - 10 of 328923 matches for " S. Wagner "
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Hermeneutical Engineering of Requirements  [PDF]
Wagner Varalda, ítalo S. Vega
Journal of Computer and Communications (JCC) , 2017, DOI: 10.4236/jcc.2017.52002
Abstract: The Software Engineering aims to develop, within the deadlines and costs established, quality software and that meets the needs of its users. To be made the definition of what the software should do (to establish its purpose), it included the execution of activity the Requirements Engineering, where the context of software to be developed is identified, examined and specified. All other activities of software development depend primarily on this activity. However, there is a problem increasingly in evidence: understand the context of software to be developed. This article aims to present a proposal to face this problem through the use of specific hermeneutical methods for the Requirements Engineering, which will help the software development team understand the original needs of the business to be attended. The basic idea is to produce a hermeneutic specification acceptable, which will be used for the extraction and the specification of the software requirements to be developed. In essence, the hermeneutics focuses on the true interpretation and understanding in contextualized of what is intended to know. The Hermeneutical Engineering of Requirements comes to be the result of the adequacy of methods hermeneutical to assist, specifically the activity of Engineering of Requirements.
International Recommendations on Calculation of Absorbed Dose in Biota: A Comprehensive Revue  [PDF]
Wagner de S. Pereira, Alphonse Kelecom
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.59077

Since the early times, radioprotection has been focused on the human being. Currently this approach has changed, being now also necessary to take care of the protection of the environment from unwanted effects of ionizing radiation. To this end, several institutions (UNSCEAR, ICRP, IAEA, DOE, ACRP) and consortia of institutions (FASSET, ERICA) have established procedures in order to protect the biota of such effects. Developed procedures are based on the calculation of the absorbed dose in biota (ICRP, DOE, IAEA), or on environmental risk assessment―ERA (DOE, ACRP, FASSET, ERICA); but even in this latter approach the parameters used are related to the absorbed doses in biota. The calculation of dose is the standard procedure in human radioprotection, and this points such an approach as the most interesting for providing a convergence between human and nonhuman (= biota) radioprotections. On the other hand, the ERA approach is easier to apply, because this methodology is used in several countries for non-radioactive contamination assessments. Since the world radioprotection system follows a number of institutions (UNSCEAR, ICRP, IAEA and regulatory institutions of member countries) that use dose calculation, this appears to be the way for biota radioprotection. We here review and comment the evolution of the concepts and approaches of the recommendations for radioprotection of non-human biota.

Visualization of the flow profile inside a thinning filament during capillary breakup of a polymer solution via particle image velocimetry (PIV) and particle tracking velocimetry (PTV)
S. Gier,C. Wagner
Physics , 2012,
Abstract: We investigated the flow profile of a polymer solution in a thinning capillary bridge. Fluorescent tracer particles with a diameter of 3$\mu$m were used to visualize the flow. The cylindrical shape of the filament introduced strong optical abberations that could be corrected for, and we were able to characterize the flow in filaments with a thickness ranging from 150 to 30 $\mu$m. In the first regime when the filament was still sufficiently large, we used a PIV algorithm to deduce the flow field. At later stages when the number of particles in the observation plane decreased a PTV algorithm was used. The main two results of our measurements are as follows. First, the flow profile at the formation of the cylindrical filament is highly inhomogeneous and there is only flow in the outer parts of the filament. Second, we find that in most parts of the regime, where the temporal radius of the thinning filament can be fitted with an exponential law the flow indeed is purely extensional.
Are GeV and TeV spectra connected? the case of Galactic gamma-ray sources
P. Tam,S. Wagner
Physics , 2011,
Abstract: To understand Galactic objects that emits GeV-TeV emission, a spatial correlation study between the Fermi bright source catalog and TeV source population was carried out in Tam et al. (2010), finding that a significant number of very high-energy (VHE; E >100 GeV) sources are also emitting at GeV energies. We extended our previous study utilizing the first Fermi catalog (1FGL) sources. A cross-correlation comparison of the 1FGL sources was carried out with the VHE gamma-ray sources in the literature as of May 2011. While it is found that a significant number of VHE gamma-ray sources were also detected in the GeV band, the GeV-TeV spectra of some of these spatially coincident sources cannot be described by a single spectral component. While some of these cases are gamma-ray pulsars accompanied by VHE gamma-ray emitting nebulae, we present cases where the 100 MeV to multi-TeV spectra of coincident 1FGL/VHE source pairs do not seem to be well fit by a single spectral component.
Towards a Macroscopic Modelling of the Complexity in Traffic Flow
S. Rosswog,P. Wagner
Physics , 2001, DOI: 10.1103/PhysRevE.65.036106
Abstract: We present a macroscopic traffic flow model that extends existing fluid-like models by an additional term containing the second derivative of the safe velocity. Two qualitatively different shapes of the safe velocity are explored: a conventional Fermi-type function and a function exhibiting a plateau at intermediate densities. The suggested model shows an extremely rich dynamical behaviour and shows many features found in real-world traffic data.
Monte Carlo simulations of antiferromagnetic small particles
Leite, Vanessa S.;Figueiredo, Wagner;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000300025
Abstract: we performed monte carlo simulations considering two different models for antiferromagnetic small particles with ising spins. the spins of the particle are disposed at the sites of the two dimensional arrays with coordination numbers z = 4 and z = 6, around a central spin. the core spins interact antiferromagnetically and the spins at the surface of the particle are disordered. in the first model, we consider an antiferromagnetic core surrounded by a disordered surface of the spin-glass type. in the second model, the core is still antiferromagnetic, but some bonds at the surface are broken. we determined the hysteresis curves, the zero-field-cooling (zfc) and field-cooling (fc) curves. we have shown that the model with a disordered surface of the spin-glass type fits better the experimental measurements determined for the antiferromagnetic nanoparticles.
Editorial: Collaborative Knowledge Management and E-Learning
Helen S. Du,Christian Wagner
Knowledge Management & E-Learning : an International Journal , 2011,
Abstract: Finding effective ways to collaborate, and to create and share knowledge among people who are connected via disperse networks is one of the most challenging tasks. Many of our traditional learning models and educational systems are not yet ready for new forms of collaboration and knowledge management due to recent technology advancement. To achieve effective education and training, we need to pay attention not only to the technology itself, but also to technology infrastructures, pedagogies, social, and management aspects. This special issue of the KM&EL international journal focuses on recent directions for the alignment of collaborative knowledge management and e-learning, and their rising impact on research and pedagogical practice.
Revision of the early Middle Pleistocene bears (Ursidae, Mammalia) of Central Europe, with special respect to possible co-occurrence of spelaeoid and arctoid lineages
Wagner J,?ermák S
Bulletin of Geosciences , 2012, DOI: 10.3140/bull.geosci.1354
Abstract: The bears from the Late Biharian localities Koněprusy Caves, C 718 and Kozi Grzbiet differ significantly from U. arctos, particularly in morphology of metaconid and entoconid complex of m1. In contrast, they exhibit a number of dental morphometric characters typical for spelaeoid lineage for which we interpret them as the early members of U. deningeri clade. Also the nominal taxa U. suessenbornensis, U. etruscus gombaszogensis and U. savini are assigned to spelaeoid lineage. U. sackdillingensis is tentatively assigned to arctoid lineage, similarly as few single specimens from Late Biharian sites Chlum 4, K vesvárad, P ezletice and Voigtstedt. All other material from these sites was identified as U. deningeri. A smaller part of the studied material, including the type series of U. eberbachensis, is of ambiguous taxonomical status and do not allow an exact species determination.
Measuring the Globalization of Knowledge Networks
Caroline S. Wagner,Loet Leydesdorff
Physics , 2009,
Abstract: This paper presents a method of understanding the growth of global science as resulting from a mechanism of preferential attachment within networks. The paper seeks to contribute to the development of indicators of knowledge creation and transfer by presenting a theory and case study of network structures in science. It is our view that indicator development has suffered from a lack of attention to the theoretical basis for understanding the dynamics of knowledge creation. This lack has been due, in part, to the difficulty of measuring dynamic systems within social organizations. This paper attempts to fill this gap by proposing theory-based indicators of knowledge creation using network theory and analysis. The paper presents a hypothesis about the knowledge system that is explored by analyzing the growth of international collaboration in science.
Network Structure, Self-Organization and the Growth of International Collaboration in Science
Caroline S. Wagner,Loet Leydesdorff
Physics , 2009,
Abstract: Using data from co-authorships at the international level in all fields of science in 1990 and 2000, and within six case studies at the sub-field level in 2000, different explanations for the growth of international collaboration in science and technology are explored. We find that few of the explanations within the literature can be supported by a detailed review of the data. To enable further exploration of the role of recognition and rewards as ordering mechanisms within the system, we apply new tools emerging from network science. These enquiries shows that the growth of international co-authorships can be attributed to self-organizing phenomenon based on preferential attachment (searching for recognition and reward) within networks of co-authors. The co-authorship links can be considered as a complex network with sub-dynamics involving features of both competition and cooperation. The analysis suggests that the growth of international collaboration is more likely to emerge from dynamics at the sub-field level operating in all fields of science, albeit under institutional constraints. Implications for the management of global scientific collaborations are explored.
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