Fuzzy logic as a decision-making support system for the indication of bariatric surgery based on an index (OBESINDEX) generated by the association between body fat and body mass index

Background: A Fuzzy Obesity Index (OBESINDEX) for use as an alternative in bariatric surgery indication (BSI) is presented. The search for a more accurate method to evaluate obesity and to indicate a better treatment is important in the world health context. BMI (body mass index) is considered the main criteria for obesity treatment and BSI. Nevertheless, the fat excess related to the percentage of Body Fat (%BF) is actually the principal harmful factor in obesity disease that is usually neglected. This paper presents a new fuzzy mechanism for evaluating obesity by associating BMI with %BF that yields a fuzzy obesity index for obesity evaluation and treatment and allows building up a Fuzzy Decision Support System (FDSS) for BSI.

Methods: Seventy-two patients were evaluated for both BMI and %BF. These data are modified and treated as fuzzy sets. Afterwards, the BMI and %BF classes are aggregated yielding a new index (OBESINDEX) for input linguistic variable are considered the BMI and %BF, and as output linguistic variable is employed the OBESINDEX, an obesity classification with entirely new classes of obesity in the fuzzy context as well is used for BSI.

Results: There is a gradual, smooth obesity classification and BSI when using the proposed fuzzy obesity index when compared with other traditional methods for dealing with obesity.

Conclusion: The BMI is not adequate for surgical indication in all the conditions and fuzzy logic becomes an alternative for decision making in bariatric surgery indication based on the OBESINDEX

Pressure effect in the X-ray intrinsic position resolution in noble gases and mixtures

A study of the gas pressure effect in the position resolution of an interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic position resolution for pure noble gases (Argon and Xenon) and their mixtures with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for photon energies between 5.4 and 60.0 keV, being possible to establish a linear match between the intrinsic position resolution and the inverse of the gas pressure in that energy range. In order to evaluate the quality of the method here described, a comparison between the available experimental data and the calculated one in this work, is done and discussed. In the majority of the cases, a strong agreement is observed

The Resistive-Plate WELL with Argon mixtures - a robust gaseous radiation detector

A thin single-element THGEM-based, Resistive-Plate WELL (RPWELL) detector was operated with 150 GeV/c muon and pion beams in Ne/(5%CH$_4$), Ar/(5%CH$_4$) and Ar/(7%CO$_2$); signals were recorded with 1 cm$^2$ square pads and SRS/APV25 electronics. Detection efficiency values greater than 98% were reached in all the gas mixtures, at average pad multiplicity of 1.2. The use of the 10$^9${\Omega}cm resistive plate resulted in a completely discharge-free operation also in intense pion beams. The efficiency remained essentially constant at 98-99% up to fluxes of $\sim$10$^4$Hz/cm$^2$, dropping by a few % when approaching 10$^5$ Hz/cm$^2$. These results pave the way towards cost-effective, robust, efficient, large-scale detectors for a variety of applications in future particle, astro-particle and applied fields. A potential target application is digital hadron calorimetry.Comment: presented at the 2016 VIenna Conf. On instrumentation. Submitted to the Conference proceeding

NUMERICAL STUDY OF A CAPACITIVE TOMOGRAPHY SYSTEM FOR MULTIPHASE FLOW

This paper presents the development of a capacitive tomography system applied to the study of multiphase flows. A numerical analysis, through the finite elements method, was performed to obtain data for the optimization ofthe geometry of the capacitance sensor. The image reconstruction of several flow patterns was obtained through the method of linear back projection, allowing the verification of the influence of several parameters upon the quality of the images, making its application easier in an experimental procedure. Several numerical simulations were performed for air-water flow, for the stratified and annular patterns. A resource of cut-off level, which depends of previous knowledge of the liquid fraction, was implemented in a way to improve the quality of the reconstructed images. The results obtained for several values of void fraction and for different patterns of flow, demonstrate the validity of the developed tomographic system

EXPERIMENTAL STUDY OF A CAPACITIVE TOMOGRAPHY SYSTEM FOR MULTIPHASE FLOW

This paper presents the experimental development of a capacitive tomography system applied to the study of multiphase flows. A capacitance sensor with eight electrodes and a capacitance measurement transducer were constructed. The two-phase flow void fraction was obtained through an electric-mechanical measurement system. The reconstruction of the image of several two-phase flows was obtained using the linear back projection method. Numerical simulation of the capacitance values between electrode pairs wereperformed, through the method of finite elements, in order to obtain the sensibility maps. This experimental procedure showed the influence of several parameters on the quality of the reconstructed images. The quality of the reconstructed images for air-water and water-oil flows, for different void fractions, demonstrated the validity of the tomography system developed