Targeting optimum resource allocation using reverse problem formulations and property clustering techniques

Decoupling the constitutive equations from the balance and constraint equations allows for reformulating a conventional forward problem into two reverse problems. The first reverse problem is the reverse of a simulation problem, where the process model is solved in terms of the constitutive (synthesis/design) variables instead of the process variables, thus providing the synthesis/design targets. The second reverse problem (reverse property prediction) solves the constitutive equations to identify unit operations, operating conditions and/or products by matching the synthesis/design targets. Visualization of the problem is achieved by employing recently developed property clustering techniques, which allows a high-dimensional problem to be visualized in two or three dimensions. The clusters by definition satisfy intra-stream and inter-stream conservation through linear “mixing” rules, which allows for the development of consistent additive rules along with their ternary representation.     

OpenCOPI: middleware integration for Ubiquitous Computing

In this paper, we present OpenCOPI (Open COntext Platform Integration), a Service-Oriented Architecture-based middleware platform that supports the integration of services provided by distinct sources, ranging from services offered by simple systems to more complex services provided by context-provision middleware. OpenCOPI offers selection and composition mechanisms to, respectively, select and compose services provided by different sources, considering applications of both Quality of Service and Quality of Context requirements. It also offers an adaptation mechanism that enables to adapt the application execution due to service failures, service quality fluctuation and user mobility. OpenCOPI allows the definition of applications in a higher abstraction level by the specification of a semantic workflow that contains abstract activities. This paper illustrates the use of OpenCOPI in an application from the Gas & Oil Industry and it also shows the evaluation of the main mechanisms of OpenCOPI: the service selection, composition, adaptation and workflow execution.     

Fast and versatile texture-based wireframe rendering

This paper revisits the problem of wireframe rendering, which, at first, appears to be an easily solved problem. However, the conventional solution is inefficient and does not result in high-quality images. Recently, graphics hardware programming has been employed to achieve high-quality solid line rendering. In this paper, we present a simpler and faster technique for wireframe rendering based on texture mapping. Our technique does not require (but can benefit from) graphics hardware programming and thus can be easily integrated into existing rendering engines, while resulting in fast, accurate, high-quality, anti-aliased, and still versatile, wireframe drawing. For topologically structured meshes, our approach allows the rendering of wireframe decoupled from the underlying mesh, making possible the rendering of original wireframes on top of decimated meshes.     

Evaluation of potential interfering agents on in vitro methods for the determination of the antioxidant capacity in anthocyanin extracts

The evaluation of the effects of sugars, metals, acids and other antioxidants on the in vitro antioxidant capacity of purified anthocyanin extract by different techniques was the purpose of this study. Three methods and the ways of expressing their results were evaluated: ABTS_TEAC (capacity equivalent to Trolox, by ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid))), DPPH_TEAC (capacity equivalent to Trolox, by DPPH (2,2‐diphenyl‐1‐picrylhydrazyl)), DPPH_EC50 (50% reduction in the radical, by DPPH), DPPH_%Sca (reduction in the scavenging capacity, by DPPH), FRAP_TEAC (capacity equivalent to Trolox, by FRAP (reduction power of iron)) and FRAP_EC50 (50% reduction in the radical, by FRAP). The way of expressing DPPH and FRAP results as EC50 showed the greater interfering extent, mainly when the medium contained tartaric and ascorbic acids. The most coherent method was ABTS_TEAC in which only ascorbic acid interfered. Ascorbic acid was shown to interfere in all methods; thus, it must be removed prior to determining the in vitro antioxidant capacity of anthocyanins in food materials.     

An Automated Investing Method for Stock Market Based on Multiobjective Genetic Programming

Stock market automated investing is an area of strong interest for the academia, casual, and professional investors. In addition to conventional market methods, various sophisticated techniques have been employed to deal with such a problem, such as ARCH/GARCH predictors, artificial neural networks, fuzzy logic, etc. A computational system that combines a conventional market method (technical analysis), genetic programming, and multiobjective optimization is proposed in this work. This system was tested in six historical time series of representative assets from Brazil stock exchange market (BOVESPA). The proposed method led to profits considerably higher than the variation of the assets in the period. The financial return was positive even in situations in which the share lost market value.     

Hancornia speciosa latex for biomedical applications: physical and chemical properties,biocompatibility assessment and angiogenic activity

The latex obtained from Hancornia speciosa is used in folk medicine for treatment of several diseases, such as acne, warts, diabetes, gastritis and inflammation. In this work, we describe the biocompatibility assessment and angiogenic properties of H. speciosa latex and its potential application in medicine. The physical–chemical characterization was carried out following different methodologies (CHN elemental analyses; thermogravimetric analyses and Fourier transform infrared spectroscopy). The biocompatibility was evaluated through cytotoxicity and genotoxicity tests in fibroblast mouse cells and the angiogenic properties were evaluated using the chick chorioallantoic membrane (CAM) assay model. The physical–chemical results showed that the structure of Hancornia speciosa latex biomembrane is very similar to that of Hevea brasiliensis (commercially available product). Moreover, the cytotoxicity and genotoxicity assays showed that H. speciosa latex is biocompatible with life systems and can be a good biomaterial for medical applications. The CAM test showed the efficient ability of H. speciosa latex in neovascularization of tissues. The histological analysis was in accordance with the results obtained in the CAM assay. Our data indicate that the latex obtained from H. speciosa and eluted in water showed significant angiogenic activity without any cytotoxic or genotoxic effects on life systems. The same did not occur with H. speciosa latex stabilized with ammonia. Addition of ammonia does not have significant effects on the structure of biomembranes, but showed a smaller cell survival and a significant genotoxicity effect. This study contributes to the understanding of the potentialities of H. speciosa latex as a source of new phytomedicines.     

Semi-parametric second-order reduced-bias high quantile estimation

In many areas of application, like, for instance, Climatology, Hydrology, Insurance, Finance, and Statistical Quality Control, a typical requirement is to estimate a high quantile of probability 1−p, a value high enough so that the chance of an exceedance of that value is equal to p, small. The semi-parametric estimation of high quantiles depends not only on the estimation of the tail index or extreme value index γ, the primary parameter of extreme events, but also on the adequate estimation of a scale first order parameter. Recently, apart from new classes of reduced-bias estimators for γ>0, new classes of the scale first order parameter have been introduced in the literature. Their use in quantile estimation enables us to introduce new classes of asymptotically unbiased high quantiles’ estimators, with the same asymptotic variance as the (biased) “classical” estimator. The asymptotic distributional properties of the proposed classes of estimators are derived and the estimators are compared with alternative ones, not only asymptotically, but also for finite samples through Monte Carlo techniques. An application to the log-exchange rates of the Euro against the Sterling Pound is also provided.     

Enantioseparation via EIC‐OSN: Process design and improvement of enantiomers resolvability and separation performance

This article presents a mathematical model to assess and optimize the separation performance of an enantioselective inclusion complexation‐organic solvent nanofiltration process. Enantiomer solubilities, feed concentrations, solvent compositions, permeate solvent volumes, and numbers of nanofiltrations were identified as key factors for process efficiency. The model was first tested by comparing calculated and experimental results for a nonoptimized process, and then, calculations were carried out to select the best operating conditions. An important finding was that the optimal configuration varied with the objective function selected, e.g., resolvability versus yield, with a boundary on product optical purity. The model also suggested that the process efficiency could benefit from diafiltration of the distomer and from the use of higher feed concentrations. However, the latter strategy would result in higher losses of eutomer. To address this drawback, a multistage process was evaluated using the verified process model. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

A unified interaction model for multiphase flows with the lattice Boltzmann method

The lattice Boltzmann method (LBM) has been increasingly adopted for modelling multiphase fluid simulations in engineering problems. Although relatively easy to implement, the ubiquitous Shan–Chen pseudopotential model suffers from limitations such as thermodynamic consistency and the formation of spurious currents. In the literature, the Zhang–Chen, Kupershtokh et al., the β-scheme, and the Yang–He alternative models seek to mitigate these effects. Here, through analytical manipulations, we call attention to a unified model from which these multiphase interaction forces can be recovered. Isothermal phase-transition simulations of single-component in stationary and oscillating droplet conditions, as well as spinodal decomposition calculations, validate the model numerically and reinforce that the multiphase forces are essentially equivalent. Parameters are selected based on the vapour densities at low temperatures in the Maxwell coexistence curve, where there is a narrow range of optimal values. We find that expressing the model parameters as functions of the reduced temperature further enhances the thermodynamic consistency without losing stability or increasing spurious velocities.