4,005 research outputs found
Counterexample Guided Inductive Optimization Applied to Mobile Robots Path Planning (Extended Version)
We describe and evaluate a novel optimization-based off-line path planning
algorithm for mobile robots based on the Counterexample-Guided Inductive
Optimization (CEGIO) technique. CEGIO iteratively employs counterexamples
generated from Boolean Satisfiability (SAT) and Satisfiability Modulo Theories
(SMT) solvers, in order to guide the optimization process and to ensure global
optimization. This paper marks the first application of CEGIO for planning
mobile robot path. In particular, CEGIO has been successfully applied to obtain
optimal two-dimensional paths for autonomous mobile robots using off-the-shelf
SAT and SMT solvers.Comment: 7 pages, 14rd Latin American Robotics Symposium (LARS'2017
Improvement of bagasse fiber–cement composites by addition of bacterial nanocellulose: an inverse gas chromatography study
The design of green fiber-reinforced
nanocomposites with enhanced properties and dura bility has attracted attention from scientists. The
present study aims to investigate the potential of
bacterial nanocellulose (BNC) as a green additive for
fiber–cement composites. Inverse gas chromatography
(IGC) was used to evaluate the influence of incorpo ration of BNC as powder or gel, or coated onto the
bagasse fibers, on the fiber–cement composite (FCC)
surface. The results indicated that BNC incorporation
made the FCC surface more reactive, increasing the
dispersive component of the surface energy. The most
relevant effects were found for BNC incorporation as
gel or coated on the fibers. Incorporation of BNC as
gel resulted in a predominantly organic FCC surface
with substantial decreased surface basicity (Ka/Kb
ratio from 2.88 to 5.75). IGC also showed that FCC
with BNC incorporated as gel was more susceptible to
hydration. However, BNC coated on fibers prevented
fiber mineralization, increasing the inorganic materi als at the surface, which caused an increase in the
surface basicity (Ka/Kb ratio decrease to 2.00). These
promising results could contribute to development of a
new generation of green hybrid composites. The IGC
technique enabled understanding of the physicochem ical changes that occur on deliberate introduction of
nanosized bacterial cellulose into fiber–cement
composites.info:eu-repo/semantics/publishedVersio
The Beta Generalized Exponential Distribution
We introduce the beta generalized exponential distribution that includes the
beta exponential and generalized exponential distributions as special cases. We
provide a comprehensive mathematical treatment of this distribution. We derive
the moment generating function and the th moment thus generalizing some
results in the literature. Expressions for the density, moment generating
function and th moment of the order statistics also are obtained. We discuss
estimation of the parameters by maximum likelihood and provide the information
matrix. We observe in one application to real data set that this model is quite
flexible and can be used quite effectively in analyzing positive data in place
of the beta exponential and generalized exponential distributions
Bentonite from Porto Santo Island, Madeira Archipelago: surface properties studied by inverse gas chromatography
The present paper shows the importance of Inverse Gas Chromatography (IGC) for
the determination of the surface properties of bentonites. These properties are dispersive surface
energy, acid-base properties, surface heterogeneity, sorption isotherms, BET surface areas and heat
of sorption, using different probe molecules. IGC can contribute to the interpretation, prediction and
optimization of the studied materials’ properties. The paper focuses on two distinctive bentonite
samples from Porto Santo Island, Madeira archipelago. In view of their potential value, achieved
through their incorporation in products for dermopharmacy and dermocosmetics, particle size and
particle surface properties are of fundamental importance.info:eu-repo/semantics/publishedVersio
Opto-mechanical Response Of A Suspended-slab-core Optical Fiber
In this paper we report the numerical evaluation of the opto-mechanical response of a microstructured optical fiber design when submitted to hydrostatic pressure. The fiber was built in silica and is composed of two large holes surrounding a wide thin flat region (suspended-slab-core) that is able to support optical propagating modes. A full-vector finite element program was used to the stress-optical analysis. The opto-mechanical sensitivity of such fiber was evaluated under two schemes of applied hydrostatic pressure. © American Institute of Physics.1055141144Bjarklev, A., Broeng, J., Bjarklev, A.S., (2003) Photonic Crystal Fibres, , Boston, Kluwer Academic PublishersJoly, N.Y., Birks, T.A., Yulin, A., Knight, J.C., St. Russel, P.J., (2005) Optics Letters, 30 (18), pp. 2469-2471Szpulak, M., Martynkien, T., Urbanczyk, W., (2004) Applied Optics, 43 (24), pp. 4739-4744Schreiber, T., Schultz, O., Schmidt, O., Röser, F., Limpert, J., Tünnermann, A., (2005) Optics Express, 13 (10), pp. 3637-3646MacPherson, W.N., Rigg, E.J., Jones, J.D.C., Kumar, V.V.R.K., Knight, J.C., St, P., Russel, J., (2005) IEEE J. Lightwave Technol, 23 (3), pp. 1227-123
Numerical And Experimental Studies For A High Pressure Photonic Crystal Fiber Based Sensor
We report a study of using photonic crystal fibers (PCFs) for high pressure applications. An opto-mechanical analysis was realized in regular PCFs and suspended-core microstructured optical fibers for different fiber geometrical parameters. It was found that the pressure sensitivity is highly dependent on the fiber structure. It was also experimentally shown that even small core PCFs with high air filling fraction can deal with pressures as high as 500 bar (7350 psi) without any noticeable problem. © American Institute of Physics.1055133136de Matos, C.J.S., (2008) CLEO conferenceR.E.P. de Oliveira, submitted to WSOF2008 AIP Proceedings (2008)Cordeiro, C.M.B., (2007) Optics Letters, 32, pp. 3324-3326Szpulak, M., Martynkien, T., Urbanczyk, W., (2004) Appl. Optics, 43, pp. 4739-4744MacPherson, W.N., (2005) Journal Light, 23, pp. 1227-1231. , TechnZhou, J., (2006) OFC'06, WI2Kosolapov, A.F., (2006) Inorganic Materials, 43, pp. 310-31
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