926 resultados para Simultaneous Similarity
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We present simultaneous and continuous observations of the Hα, Hβ, He I D_3, Na I D_1,D_2 doublet and the Ca II H&K lines for the RS CVn system HR 1099. The spectroscopic observations were obtained during the MUSICOS 1998 campaign involving several observatories and instruments, both echelle and long-slit spectrographs. During this campaign, HR 1099 was observed almost continuously for more than 8 orbits of 2^d.8. Two large optical flares were observed, both showing an increase in the emission of Hα, Ca II H K, Hβ and He I D_3 and a strong filling-in of the Na I D_1, D_2 doublet. Contemporary photometric observations were carried out with the robotic telescopes APT-80 of Catania and Phoenix-25 of Fairborn Observatories. Maps of the distribution of the spotted regions on the photosphere of the binary components were derived using the Maximum Entropy and Tikhonov photometric regularization criteria. Rotational modulation was observed in Hα and He I D_3 in anti-correlation with the photometric light curves. Both flares occurred at the same binary phase (0.85), suggesting that these events took place in the same active region. Simultaneous X-ray observations, performed by ASM on board RXTE, show several flare-like events, some of which correlate well with the observed optical flares. Rotational modulation in the X-ray light curve has been detected with minimum flux when the less active G5 V star was in front. A possible periodicity in the X-ray flare-like events was also found.
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Nonclassicality cannot be a single-observable property, since the statistics of any quantum observable is compatible with classical physics. We develop a general procedure to reveal nonclassical behavior of light states from the joint statistics arising in the practical measurement of multiple observables. Beside embracing previous approaches, this protocol can disclose nonclassical features for standard examples of classical-like behavior, such as SU(2) and Glauber coherent states. When combined with other criteria, this would imply that every light state is nonclassical.
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Póster presentado en SPIE Photonics Europe, Brussels, 16-19 April 2012.
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Retinal image quality is commonly analyzed through parameters inherited from instrumental optics. These parameters are defined for ‘good optics’ so they are hard to translate into visual quality metrics. Instead of using point or artificial functions, we propose a quality index that takes into account properties of natural images. These images usually show strong local correlations that help to interpret the image. Our aim is to derive an objective index that quantifies the quality of vision by taking into account the local structure of the scene, instead of focusing on a particular aberration. As we show, this index highly correlates with visual acuity and allows inter-comparison of natural images around the retina. The usefulness of the index is proven through the analysis of real eyes before and after undergoing corneal surgery, which usually are hard to analyze with standard metrics.
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We present an experience in Nursing Education, accredited and implemented under the Spanish University System Reform in a Public University (Jaume I, Castellón) which had no previous nursing studies. The academics offered included all three educational levels (Bachelor, Master's and Doctorate), with an integrated theoretical-practical-clinical teaching methodology for the Bachelor Degree, competence acquisition in research in the Master's degree, and a doctorate formed by lines of research in the field of Nursing. Studies are accredited by the National Agency for Quality Assessment, which were authorized by the Spanish Ministry of Education and implanted between 2009 and 2011.
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The optimal integration between heat and work may significantly reduce the energy demand and consequently the process cost. This paper introduces a new mathematical model for the simultaneous synthesis of heat exchanger networks (HENs) in which the pressure levels of the process streams can be adjusted to enhance the heat integration. A superstructure is proposed for the HEN design with pressure recovery, developed via generalized disjunctive programming (GDP) and mixed-integer nonlinear programming (MINLP) formulation. The process conditions (stream temperature and pressure) must be optimized. Furthermore, the approach allows for coupling of the turbines and compressors and selection of the turbines and valves to minimize the total annualized cost, which consists of the operational and capital expenses. The model is tested for its applicability in three case studies, including a cryogenic application. The results indicate that the energy integration reduces the quantity of utilities required, thus decreasing the overall cost.
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Background: Few qualitative studies of simultaneous pancreas-kidney transplantation (SPK Tx) have been published. The aims of this study were to explore from the perspective of patients, the experience of living with diabetes mellitus type 1 (T1DM), suffering from complications, and undergoing SPK Tx with good outcome; and to determine the impact of SPK Tx on patients and their social and cultural environment. Methods: We performed a focused ethnographic study. Twenty patients were interviewed. Data were analyzed using content analysis and constant comparison following the method proposed by Miles and Huberman. Results: A functioning SPK Tx allowed renal replacement therapy and insulin to be discontinued. To describe their new situation, patients used words and phrases such as "miracle", "being reborn" or "coming back to life". Although the complications of T1DM, its surgery and treatment, and associated psychological problems did not disappear after SPK Tx, these were minimized when compared with the pretransplantation situation. Conclusion: For patients, SPK Tx represents a recovery of their health and autonomy despite remaining problems associated with the complications of T1DM and SPK Tx. The understanding of patients' existential framework and their experience of disease are key factors for planning new intervention and improvement strategies.
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The optimal integration of work and its interaction with heat can represent large energy savings in industrial plants. This paper introduces a new optimization model for the simultaneous synthesis of work exchange networks (WENs), with heat integration for the optimal pressure recovery of process gaseous streams. The proposed approach for the WEN synthesis is analogous to the well-known problem of synthesis of heat exchanger networks (HENs). Thus, there is work exchange between high-pressure (HP) and low-pressure (LP) streams, achieved by pressure manipulation equipment running on common axes. The model allows the use of several units of single-shaft-turbine-compressor (SSTC), as well as stand-alone compressors, turbines and valves. Helper motors and generators are used to respond to any demand and excess of energy. Moreover, between the WEN stages the streams are sent to the HEN to promote thermal recovery, aiming to enhance the work integration. A multi-stage superstructure is proposed to represent the process. The WEN superstructure is optimized in a mixed-integer nonlinear programming (MINLP) formulation and solved with the GAMS software, with the goal of minimizing the total annualized cost. Three examples are conducted to verify the accuracy of the proposed method. In all case studies, the heat integration between WEN stages is essential to improve the pressure recovery, and to reduce the total costs involved in the process.
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This multidisciplinary study concerns the optimal design of processes with a view to both maximizing profit and minimizing environmental impacts. This can be achieved by a combination of traditional chemical process design methods, measurements of environmental impacts and advanced mathematical optimization techniques. More to the point, this paper presents a hybrid simulation-multiobjective optimization approach that at once optimizes the production cost and minimizes the associated environmental impacts of isobutane alkylation. This approach has also made it possible to obtain the flowsheet configurations and process variables that are needed to manufacture isooctane in a way that satisfies the above-stated double aim. The problem is formulated as a Generalized Disjunctive Programming problem and solved using state-of-the-art logic-based algorithms. It is shown, starting from existing alternatives for the process, that it is possible to systematically generate a superstructure that includes alternatives not previously considered. The optimal solution, in the form a Pareto curve, includes different structural alternatives from which the most suitable design can be selected. To evaluate the environmental impact, Life Cycle Assessment based on two different indicators is employed: Ecoindicator 99 and Global Warming Potential.
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In a previous work, we introduced a tool for analyzing multiple datasets simultaneously, which has been implemented into ISIS. This tool was used to fit many spectra of X-ray binaries. However, the large number of degrees of freedom and individual datasets raise an issue about a good measure for a simultaneous fit quality. We present three ways to check the goodness of these fits: we investigate the goodness of each fit in all datasets, we define a combined goodness exploiting the logical structure of a simultaneous fit, and we stack the fit residuals of all datasets to detect weak features. These tools are applied to all RXTE-spectra from GRO 1008−57, revealing calibration features that are not detected significantly in any single spectrum. Stacking the residuals from the best-fit model for the Vela X-1 and XTE J1859+083 data evidences fluorescent emission lines that would have gone undetected otherwise.
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Background/Aims: The simultaneous use of alcohol and cannabis is common among adolescents, but has been little studied. In this study, we examine predictors and consequences of this behavior in a population-based sample of high school students. Method: Self-reports were obtained from students in Quebec (Canada) followed throughout high school (N=6589). Logistic regressions were used to test the association between individual, family, and peerrelated predictors in grades 7–8 and simultaneous alcohol and cannabis use in grade 10, as well as between simultaneous alcohol and cannabis use in grade 10 and experiencing 3 or more substance-related problems of various types (legal, physical, etc.) in grade 11. Results: Most predictors in grades 7–8 were associated with simultaneous alcohol and cannabis use in grade 10. Only variables reflecting early-onset substance use involvement — alcohol intoxication, cannabis use, and drug use by close friend(s) — remained predictive in a multivariate model. Simultaneous alcohol and cannabis use was associated with increased substance-related problems in grade 11, above and beyond baseline problems and the concurrent use of the two substances in separate episodes in grade 10. Conclusions: Simultaneous alcohol and cannabis use 1) is anticipated by multiple psychosocial risk factors which come together with individual and peer substance use in early high school and 2) is independently predictive of subsequent substance-related problems. Providing adolescents with adequate information regarding the potential harm of simultaneous use may be a useful prevention strategy.
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The problem of similarity measurement of biological signals is considered on this article. The dynamic time warping algorithm is used as a possible solution. A short overview of this algorithm and its modifications are given. Testing procedure for different modifications of DTW, which are based on artificial test signals, are presented.
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Background/Aims: The simultaneous use of alcohol and cannabis is common among adolescents, but has been little studied. In this study, we examine predictors and consequences of this behavior in a population-based sample of high school students. Method: Self-reports were obtained from students in Quebec (Canada) followed throughout high school (N=6589). Logistic regressions were used to test the association between individual, family, and peerrelated predictors in grades 7–8 and simultaneous alcohol and cannabis use in grade 10, as well as between simultaneous alcohol and cannabis use in grade 10 and experiencing 3 or more substance-related problems of various types (legal, physical, etc.) in grade 11. Results: Most predictors in grades 7–8 were associated with simultaneous alcohol and cannabis use in grade 10. Only variables reflecting early-onset substance use involvement — alcohol intoxication, cannabis use, and drug use by close friend(s) — remained predictive in a multivariate model. Simultaneous alcohol and cannabis use was associated with increased substance-related problems in grade 11, above and beyond baseline problems and the concurrent use of the two substances in separate episodes in grade 10. Conclusions: Simultaneous alcohol and cannabis use 1) is anticipated by multiple psychosocial risk factors which come together with individual and peer substance use in early high school and 2) is independently predictive of subsequent substance-related problems. Providing adolescents with adequate information regarding the potential harm of simultaneous use may be a useful prevention strategy.
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Includes bibliographies (p. 23).
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Mode of access: Internet.