656 research outputs found
Representing Terrain With Mathematical Operators
This work describes a mathematical representation of terrain data consisting of a novel operation, the “drill”. It facilitates the representation of legal terrains, capturing the richness of the physics of the terrain’s generation by digging channels in the surface. Given our current reliance on digital map data, hand-held devices, and GPS navigation systems, the accuracy and compactness of terrain data representations are becoming increasingly important. Representing a terrain as a series of operations that can procedurally regenerate the terrains allows for compact representation that retains more information than height fields, TINs, and other popular representations. Our model relies on the hydrography information extracted from the terrain, and so drainage information is retained during encoding. To determine the shape of the drill along each channel in the channel network, a cross section of the channel is extracted, and a quadratic polynomial is fit to it. We extract the drill representation from a mountainous dataset, using a series of parameters (including size and area of influence of the drill, as well as the density of the hydrography data), and present the accuracy calculated using a series of metrics. We demonstrate that the drill operator provides a viable and accurate terrain representation that captures both the terrain shape and the richness of its generation
A Inserção no Mercado de Trabalho dos Egressos do Curso de Turismo e Hotelaria da Universidade do Vale do Itajaí
O turismo vem apresentando índices de crescimento expressivos e se desenvolvendo de maneira extremamente veloz, consolidando-se como atividade econômica, social, cultural e ambiental bastante significativa. Este artigo teve por objetivo avaliar a satisfação dos egressos do Curso de Turismo e Hotelaria da Universidade do Vale do Itajaí, Campus Balneário Camboriú – Santa Catarina, com relação a sua inserção no mercado de trabalho. Para tanto, foi utilizado questionário, sendo pesquisados os formando dos anos de 2001 e 2002. A população correspondente é de 160 (cento e sessenta) egressos, sendo a amostra de 73 (setenta e três). Os resultados obtidos demonstraram que a maioria dos entrevistados está atuando, principalmente na área de hotelaria, sendo que 88% fariam o Curso novamente. Entre as dificuldades apontadas, é relevante o fato de que o mercado turístico carece de profissionalismo. Diante disso, o ensino superior e o mercado turístico não podem mais ser conduzidos de forma empírica, por meio de improvisações ou esquemas amadorísticos
Long-term 24-hour intraocular pressure control with travoprost monotherapy in patients with primary open-angle glaucoma
The aim of the study was to evaluate the long-term 24-hour intraocular pressure (IOP) efficacy of travoprost monotherapy in primary open-angle glaucoma patients
Control of Hamiltonian chaos as a possible tool to control anomalous transport in fusion plasmas
It is shown that a relevant control of Hamiltonian chaos is possible through
suitable small perturbations whose form can be explicitly computed. In
particular, it is possible to control (reduce) the chaotic diffusion in the
phase space of a Hamiltonian system with 1.5 degrees of freedom which models
the diffusion of charged test particles in a turbulent electric field across
the confining magnetic field in controlled thermonuclear fusion devices. Though
still far from practical applications, this result suggests that some strategy
to control turbulent transport in magnetized plasmas, in particular tokamaks,
is conceivable. The robustness of the control is investigated in terms of a
departure from the optimum magnitude, of a varying cut-off at large wave
vectors, and of random errors on the phases of the modes. In all three cases,
there is a significant region of maximum efficiency in the vicinity of the
optimum control term.Comment: 17 pages, 21 figure
Diffusion entropy and waiting time statistics of hard x-ray solar flares
We analyze the waiting time distribution of time distances between two
nearest-neighbor flares. This analysis is based on the joint use of two
distinct techniques. The first is the direct evaluation of the distribution
function , or of the probability, , that no time
distance smaller than a given is found. We adopt the paradigm of the
inverse power law behavior, and we focus on the determination of the inverse
power index , without ruling out different asymptotic properties that
might be revealed, at larger scales, with the help of richer statistics. The
second technique, called Diffusion Entropy (DE) method, rests on the evaluation
of the entropy of the diffusion process generated by the time series. The
details of the diffusion process depend on three different walking rules, which
determine the form and the time duration of the transition to the scaling
regime, as well as the scaling parameter . With the first two rules the
information contained in the time series is transmitted, to a great extent, to
the transition, as well as to the scaling regime. The same information is
essentially conveyed, by using the third rules, into the scaling regime, which,
in fact, emerges very quickly after a fast transition process. We show that the
significant information hidden within the time series concerns memory induced
by the solar cycle, as well as the power index . The scaling parameter
becomes a simple function of , when memory is annihilated. Thus,
the three walking rules yield a unique and precise value of if the memory
is wisely taken under control, or cancelled by shuffling the data. All this
makes compelling the conclusion that .Comment: 23 pages, 13 figure
Biological Characteristics and Medical Treatment of Breast Cancer in Young Women—A Featured Population: Results from the NORA Study
Background. The present paper described the biological characteristics and clinical behavior of young women in the cohort NORA study Patients and Methods. From 2000–2002, patients (N > 3500) were enrolled at 77 Italian hospitals. Women aged ≤50 years (N = 1013) were stratified into age groups (≤35, 36–40, 41–45, and 46–50 years). The relationship between age and patient characteristics, cancer presentation, and treatment was analyzed. Results. Younger women more frequently had tumors with ER/PgR-negative(χ2 = 7.07; P = .008), HER2 amplification (χ2 = 5.76; P = .01), and high (≥10%) Ki67 labelling index (χ2 = 9.53; P = .002). Positive nodal status, large tumors, and elevated Ki67 all associated with the choice for chemotherapy followed by endocrine therapy in hormone receptor-positive patients (P < .0001). At univariate analysis, ER-ve status, chemotherapy and age resulted as the only statistically significant variables (HR = 2.02, P = .004, and >40 versus ≤40, P < .0001, resp.). At multivariate analysis, after adjustment for significant clinical and pathological factors, age remains a significant prognostic variable (HR = 0.93, P = .0021). Conclusion. This cohort study suggests that age per sè is an important prognostic factor. The restricted role of early diagnosis and the aggressive behavior of cancer in this population make necessary the application of targeted medical strategies crucial
Anomalous diffusion as a signature of collapsing phase in two dimensional self-gravitating systems
A two dimensional self-gravitating Hamiltonian model made by
fully-coupled classical particles exhibits a transition from a collapsing phase
(CP) at low energy to a homogeneous phase (HP) at high energy. From a dynamical
point of view, the two phases are characterized by two distinct single-particle
motions : namely, superdiffusive in the CP and ballistic in the HP. Anomalous
diffusion is observed up to a time that increases linearly with .
Therefore, the finite particle number acts like a white noise source for the
system, inhibiting anomalous transport at longer times.Comment: 10 pages, Revtex - 3 Figs - Submitted to Physical Review
Laser printing of micro-electronic communication systems for smart implants applications
Endow the implant with intrinsic communication system between sensors and actuators or between implant and
patient is a key factor for its long-term success. The capacity of early diagnosis of failures and the ability to
remedy them are necessary to minimize expensive complications and reducing revision procedures. Ti6Al4V is
the most used titanium alloy for implant’s fabrication. In this sense, this work presents a promising approach to
print communication systems by using laser technology, aiming integrate the smart components on titanium
implants. Laser has been employed as a versatile tool to modify the surface in different ways, such as texturing,
oxidizing and sintering. Silver wires have been printed on Ti6Al4V surface in order to conduct electrical current.
To minimize current loss for the substrate, titanium oxide layer has been produced by different methods (laser
and anodization). Laser sintering (LS) has been also compared to a conventional method (Hot-pressing- HP) to
consolidate the silver powder into the cavities. In comparison to the conventional techniques, laser demonstrated
to be a competitive approach to oxidizing the surface and also for consolidating the micro-wires on Ti6Al4V
surface. Consequently, the micro-wires printed by laser approach presented satisfactory results in terms of
electrical resistance, actuating as the conductor path for electrical current, with values of 0.0131 Ω, which is
similar to the resistance of the wire printed in an insulator substrate.This work has been supported by FCT (Fundação para a Ciência e
Tecnologia -Portugal) in the scope of the projects UID/EEA/04436/
2019 and NORTE-01-0145-FEDER-000018-HAMaBICo and
Add.Additive_Manufacturing to Portuguese Industry_POCI-01-0247-
FEDER-024533. I wish to thank the CNPq (205791/2014-0)
Thyroid Dysfunction and Anemia: A Prospective Cohort Study and a Systematic Review.
Even though the association between thyroid dysfunction and anemia is commonly described, it is not known whether it is clinically relevant. This study set out to quantify the association of thyroid dysfunction on hemoglobin (Hb) concentration and risk of anemia. A systematic review (MEDLINE and EMBASE, from inception until May 15, 2017) was conducted to interpret the findings in context.
Participants from the EPIC-Norfolk cohort with available baseline thyrotropin (TSH), free thyroxine (fT4), and Hb were included. Euthyroidism was defined as TSH 0.45-4.49 mIU/L (reference category), hypothyroidism as TSH ≥4.50 mIU/L (subclinical [SHypo] with normal fT4 or overt [OHypo] with low fT4), and hyperthyroidism as TSH ≤0.44 mIU/L (subclinical [SHyper] with normal fT4 or overt [OHyper] with elevated fT4). Anemia was defined as Hb <12 g/dL in women and Hb <13 g/dL in men. In the cross-sectional analyses, multiple linear regression was used to compare Hb across TSH categories. In the prospective analysis, participants with OHypo/OHyper at baseline were excluded, as it was assumed that they were treated for overt thyroid disease. A covariance model was used to determine change in Hb concentration from baseline to last follow-up, and multivariable Cox regression was used to analyze anemia risk.
In the cross-sectional population (n = 12,337), the adjusted Hb was 0.22 g/dL lower [confidence interval (CI) 0.07-0.38] in OHypo compared to euthyroids, and 0.08 g/dL lower [CI -0.23 to 0.38] in OHyper. In the prospective analysis, 460/7031 participants developed anemia over a median follow-up of 4.7 years. The adjusted mean Hb change over time was -0.04 g/dL in SHypo [CI -0.14 to 0.06] and 0.05 g/dL in SHyper [CI -0.10 to 0.20]. The adjusted hazard ratio for anemia was 0.99 [CI 0.67-1.48] in SHypo, and 0.52 [CI 0.23-1.16] in SHyper. The systematic review returned no other prospective studies on this association, but cross-sectional and case-control studies showed comparable results.
In this first prospective population-based cohort, subclinical thyroid dysfunction was not associated with a change in Hb concentration during follow-up and was not an independent risk factor for developing anemia; variations in Hb concentration in patients with overt thyroid dysfunction were not clinically relevant
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