Design and development of a fuzzy explainable expert system for a diagnostic robot of COVID-19

Expert systems have been widely used in medicine to diagnose different diseases. However, these rule-based systems only explain why and how their outcomes are reached. The rules leading to those outcomes are also expressed in a machine language and confronted with the familiar problems of coverage and specificity. This fact prevents procuring expert systems with fully human-understandable explanations. Furthermore, early diagnosis involves a high degree of uncertainty and vagueness which constitutes another challenge to overcome in this study. This paper aims to design and develop a fuzzy explainable expert system for coronavirus disease-2019 (COVID-19) diagnosis that could be incorporated into medical robots. The proposed medical robotic application deduces the likelihood level of contracting COVID-19 from the entered symptoms, the personal information, and the patient's activities. The proposal integrates fuzzy logic to deal with uncertainty and vagueness in diagnosis. Besides, it adopts a hybrid explainable artificial intelligence (XAI) technique to provide different explanation forms. In particular, the textual explanations are generated as rules expressed in a natural language while avoiding coverage and specificity problems. Therefore, the proposal could help overwhelmed hospitals during the epidemic propagation and avoid contamination using a solution with a high level of explicability

Reliability Analysis in Performance-based Earthquake Engineering

AbstractThe performance-based engineering approach, as opposed to prescriptive rules of code-based design, is based on simulation of real structural behavior. Reliability of the expected performance state is assessed by using various methodologies based on finite element nonlinear static pushover analysis and specialized reliability software package.Reliability approaches that were considered included full coupling with an external finite element code based methods in conjunction with either first order reliability method or importance sampling method. The building considered in the actual study has been designed against seismic hazard according to the Moroccan code RPS2000

An improved Arabic text classification method using word embedding

Feature selection (FS) is a widely used method for removing redundant or irrelevant features to improve classification accuracy and decrease the model’s computational cost. In this paper, we present an improved method (referred to hereafter as RARF) for Arabic text classification (ATC) that employs the term frequency-inverse document frequency (TF-IDF) and Word2Vec embedding technique to identify words that have a particular semantic relationship. In addition, we have compared our method with four benchmark FS methods namely principal component analysis (PCA), linear discriminant analysis (LDA), chi-square, and mutual information (MI). Support vector machine (SVM), k-nearest neighbors (K-NN), and naive Bayes (NB) are three machine learning based algorithms used in this work. Two different Arabic datasets are utilized to perform a comparative analysis of these algorithms. This paper also evaluates the efficiency of our method for ATC on the basis of performance metrics viz accuracy, precision, recall, and F-measure. Results revealed that the highest accuracy achieved for the SVM classifier applied to the Khaleej-2004 Arabic dataset with 94.75%, while the same classifier recorded an accuracy of 94.01% for the Watan-2004 Arabic dataset

Rheological properties of calcium carbonate self-setting injectable paste

With the development of minimally invasive surgical techniques, there is growing interest in the research and development of injectable biomaterials with controlled rheological properties. In this context, the rheological properties and injectability characteristics of an original CaCO3 self-setting paste have been investigated. Two complementary rheometrical procedures have been established using a controlled stress rheometer to follow the structure build-up at rest or during gentle mixing and/or handling on the one hand, and the likely shear-induced breakdown of this structure at 25 or 35 C on the other. The data obtained clearly show the influence of temperature on the development of a cement microstructure during setting, in all cases leading to a microporous cement made of an entangled network of aragonite-CaCO3 needle-like crystals. Linear viscoelastic measurements arriving from an oscillatory shear at low deformation showed a progressive increase in the viscous modulus (G0 0) during paste setting, which is enhanced by an increase in temperature. In addition, steady shear measurements revealed the shear-thinning behaviour of this self-setting paste over an extended period after paste preparation and its ability to re-build through progressive paste setting at rest. The shear-thinning behaviour of this self-setting system was confirmed using the injectability system and a procedure we designed. The force needed to extrude a homogeneous and continuous column of paste decreases strongly upon injection and reaches a weight level to apply on the syringe piston around 2.5 kg, revealing the ease of injection of this CaCO3 self-setting paste

Use of Carbon Additives towards Rechargeable Zinc Slurry Air Flow Batteries

The performance of redox flow batteries is notably influenced by the electrolyte, especially in slurry-based flow batteries, as it serves as both an ionic conductive electrolyte and a flowing electrode. In this study, carbon additives were introduced to achieve a rechargeable zinc slurry flow battery by minimizing the zinc plating on the bipolar plate that occurs during charging. When no carbon additive was present in the zinc slurry, the discharge current density was 24 mA∙cm$^{-2}$ at 0.6 V, while the use of carbon additives increased it to up to 38 mA∙cm$^{-2}$. The maximum power density was also increased from 16 mW∙cm$^{-2}$ to 23 mW∙cm$^{-2}$. Moreover, the amount of zinc plated on the bipolar plate during charging decreased with increasing carbon content in the slurry. Rheological investigation revealed that the elastic modulus and yield stress are directly proportional to the carbon content in the slurry, which is beneficial for redox flow battery applications, but comes at the expense of an increase in viscosity (two-fold increase at 100 s$^{-1}$). These results show how the use of conductive additives can enhance the energy density of slurry-based flow batteries

Numerical Modeling of Soil Erosion with Three Wall Laws at the Soil-Water Interface

In the area of civil engineering and especially hydraulic structures, we find multiple anomalies that weakens mechanical characteristics of dikes, one of the most common anomalies is erosion phenomenon specifically pipe flow erosion which causes major damage to dam structures. This phenomenon is caused by a hole which is the result of the high pressure of water that facilitate the soil migration between the two sides of the dam. It becomes only a question of time until the diameter of the hole expands and causes destruction of the dam structure. This problem pushed physicist to perform many tests to quantify erosion kinetics, one of the most used tests to have logical and trusted results is the HET (hole erosion test). Meanwhile there is not much research regarding the models that govern these types of tests. Objectives: In this paper we modeled the HET using modeling software based on the Navier Stokes equations, this model tackles also the singularity of the interface structure/water using wall laws for a flow turbulence. Methods/Analysis: The studied soil in this paper is a clay soil, clay soil has the property of containing water more than most other soils. Three wall laws were applied on the soil / water interface to calculate the erosion rate in order to avoid the rupture of such a structure. The modlisitation was made on the ANSYS software. Findings: In this work, two-dimensional modeling was carried of the soil.in contrast of the early models which is one-dimensional model, the first one had shown that the wall-shear stress which is not uniform along the whole wall. Then using the linear erosion law to predict the non-uniform erosion along the whole length. The previous study found that the wall laws have a significant impact on the wall-shear stress, which affects the erosion interface in the fluid/soil, particularly at the hole's extremes. Our experiment revealed that the degraded profile is not uniform. Doi: 10.28991/cej-2021-03091742 Full Text: PD

Development of an injectable composite for bone regeneration

With the development of minimally invasive surgical techniques, there is a growing interest in the research and development of injectable biomaterials especially for orthopedic applications. In a view to enhance the overall surgery benefits for the patient, the BIOSINJECT project aims at preparing a new generation of mineral-organic composites for bone regeneration exhibiting bioactivity, therapeutic activity and easiness of use to broaden the application domains of the actual bone mineral cements and propose an alternative strategy with regard to their poor resorbability, injectability difficulties and risk of infection. First, a physical-chemical study demonstrated the feasibility of self-setting injectable composites associating calcium carbonate-calcium phosphate cement and polysaccharides (tailor-made or commercial polymer) in the presence or not of an antibacterial agent within the composite formulation. Then, bone cell response and antimicrobial activity of the composite have been evaluated in vitro. Finally, in order to evaluate resorption rate and bone tissue response an animal study has been performed and the histological analysis is still in progress. These multidisciplinary and complementary studies led to promising results in a view of the industrial development of such composite for dental and orthopaedic applications

Pristine and modified porous membranes for zinc slurry–air flow battery

The membrane is a crucial component of Zn slurry–air flow battery since it provides ionic conductivity between the electrodes while avoiding the mixing of the two compartments. Herein, six commercial membranes (Cellophane™ 350PØØ, Zirfon®, Fumatech® PBI, Celgard® 3501, 3401 and 5550) were first characterized in terms of electrolyte uptake, ion conductivity and zincate ion crossover, and tested in Zn slurry–air flow battery. The peak power density of the battery employing the membranes was found to depend on the in-situ cell resistance. Among them, the cell using Celgard® 3501 membrane, with in-situ area resistance of 2 Ω cm$^{2}$ at room temperature displayed the highest peak power density (90 mW cm−2). However, due to the porous nature of most of these membranes, a significant crossover of zincate ions was observed. To address this issue, an ion-selective ionomer containing modified poly(phenylene oxide) (PPO) and N-spirocyclic quaternary ammonium monomer was coated on a Celgard® 3501 membrane and crosslinked via UV irradiation (PPO-3.45 + 3501). Moreover, commercial FAA-3 solutions (FAA, Fumatech) were coated for comparison purpose. The successful impregnation of the membrane with the anion-exchange polymers was confirmed by SEM, FTIR and Hg porosimetry. The PPO-3.45 + 3501 membrane exhibited 18 times lower zincate ions crossover compared to that of the pristine membrane (5.2 × 10$^{-13}$ vs. 9.2 × 10$^{-12}$ m$^{2}$ s$^{-1}$). With low zincate ions crossover and a peak power density of 66 mW cm$^{-2}$, the prepared membrane is a suitable candidate for rechargeable Zn slurry–air flow batteries