22,858 research outputs found
Process transparency on construction sites : examples from construction companies in Brazil
Process transparency is the core concept in Visual Management (VM), which is one of the founding blocks of the Toyota Production System. This paper presents the
preliminary results of a collaborative research conducted between Brazil and the UK, as part of a research effort focused on the application of Visual Management in
construction. How process transparency is realized on construction sites is the main research question of the paper. The use of this concept and the implementation of the
transparency theory were investigated through multiple case studies, carried out in nine different construction companies. The findings are explained through six theoretical transparency increasing approaches. The affecting parameters in the application of, the management’s perception of and several methods in process
transparency in construction were identified. Further work, especially exploring the functions of process transparency on construction sites and reflecting the worker perception of the issue, is necessary to elaborate the process transparency concept
New Understanding of Large Magellanic Cloud Structure, Dynamics and Orbit from Carbon Star Kinematics
We derive general expressions for the LMC velocity field which we fit to
kinematical data for 1041 carbon stars. We demonstrate that all previous
studies of LMC kinematics have made unnecessary over-simplifications that have
led to incorrect estimates of important structural parameters. We compile and
improve LMC proper motion estimates to support our analysis. We find that the
kinematically determined position angle of the line of nodes is 129.9 +/- 6.0
deg. The LMC inclination changes at a rate di/dt = -103 +/- 61 deg/Gyr, a
result of precession and nutation induced by Milky Way tidal torques. The LMC
rotation curve V(R) has amplitude 49.8 +/- 15.9 km/s, 40% lower than what has
previously (and incorrectly) been inferred from e.g. HI. The dynamical center
of the carbon stars is consistent with the center of the bar and the center of
the outer isophotes, but not with the HI kinematical center. The enclosed mass
inside 8.9 kpc is (8.7 +/- 4.3) x 10^9 M_sun, more than half of which is due to
a dark halo. The LMC has a larger vertical thickness than has traditionally
been believed. Its V/sigma is less than the value for the Milky Way thick disk.
We discuss the implications for the LMC self-lensing optical depth. We
determine the LMC velocity and orbit in the Galactocentric rest frame and find
it to be consistent with the range of velocities that has been predicted by
models for the Magellanic Stream. The Milky Way dark halo must have mass >4.3 x
10^{11} M_sun and extent >39 kpc for the LMC to be bound. We predict the LMC
proper motion velocity field, and discuss techniques for kinematical distance
estimation. [ABRIDGED]Comment: 57 pages, LaTeX, with 11 PostScript figures. Submitted to the
Astronomical Journa
An Optical Approach to the Dynamical Casimir Effect
We recently proposed a new approach to analyze the parametric resonance in a
vibrating cavity based on the analysis of classical optical paths. This
approach is used to examine various models of cavities with moving walls. We
prove that our method is useful to extract easily basic physical outcome.Comment: 9 page
Questões críticas em validação de métodos analíticos.
Experimentação e testes de hipóteses; Dificuldades em treinamentos; Nível de validação necessário e responsabilidade cabíveis; Dificuldades comuns; Incerteza; Valor verdadeiro; Realização dos experimentos de validação; Número de repetições; Faixa de trabalho; Valores aberrantes; Experimentos de precisão (estudos colaborativos); Amostragem; Incerteza de amostragem; Verificação de conformidade; Crítica de validação; Conclusões
Hunting Galaxies to (and for) Extinction
In studies of star-forming regions, near-infrared excess (NIRX)
sources--objects with intrinsic colors redder than normal stars--constitute
both signal (young stars) and noise (e.g. background galaxies). We hunt down
(identify) galaxies using near-infrared observations in the Perseus
star-forming region by combining structural information, colors, and number
density estimates. Galaxies at moderate redshifts (z = 0.1 - 0.5) have colors
similar to young stellar objects (YSOs) at both near- and mid-infrared (e.g.
Spitzer) wavelengths, which limits our ability to identify YSOs from colors
alone. Structural information from high-quality near-infrared observations
allows us to better separate YSOs from galaxies, rejecting 2/5 of the YSO
candidates identified from Spitzer observations of our regions and potentially
extending the YSO luminosity function below K of 15 magnitudes where galaxy
contamination dominates. Once they are identified we use galaxies as valuable
extra signal for making extinction maps of molecular clouds. Our new iterative
procedure: the Galaxies Near Infrared Color Excess method Revisited (GNICER),
uses the mean colors of galaxies as a function of magnitude to include them in
extinction maps in an unbiased way. GNICER increases the number of background
sources used to probe the structure of a cloud, decreasing the noise and
increasing the resolution of extinction maps made far from the galactic plane.Comment: 16 pages and 16 figures. Accepted for publication in ApJ. Full
resolution version at
http://www.cfa.harvard.edu/COMPLETE/papers/Foster_HuntingGalaxies.pd
Numerical comparison of two approaches for the study of phase transitions in small systems
We compare two recently proposed methods for the characterization of phase
transitions in small systems. The validity and usefulness of these approaches
are studied for the case of the q=4 and q=5 Potts model, i.e. systems where a
thermodynamic limit and exact results exist. Guided by this analysis we discuss
then the helix-coil transition in polyalanine, an example of structural
transitions in biological molecules.Comment: 16 pages and 7 figure
Mobile laboratories as an alternative to conventional remote laboratories
Remote laboratories have been playing an important role on the improvement of flexibility and the extent of
practical activities in teaching and learning activities in engineering and technology. However, the current remote laboratories model does not consider dynamic scenarios including collaboration, peer-to-peer labs and mobile labs. This paper presents a set of tools for creating collaborative online mobile laboratories that allow students to develop their own labs and share them with classmates and teachers. The approach used is compatible with the machine and network configurations that the target user has in schools and at home, and provides the retrieval of information for learning evaluation.info:eu-repo/semantics/publishedVersio
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