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The process of “hysteresis” has widely attracted the attention of researchers and investigators due to its usage in many disciplines of science and engineering. Economics, physics, chemistry, electrical, mechanical, and petroleum engineering are some examples of disciplines that encounter hysteresis. However, the meaning of hysteresis varies from one field to another, and therefore, many definitions occur for this phenomenon depending on the area of interest. The “hysteresis” phenomenon in petroleum engineering has gained the attention of researchers and investigators lately, because of the role that plays in reservoir engineering and reservoir simulation. Hysteretic effects influence reservoir performance. Therefore, an accurate estimation of rock and fluid property curves has an essential role in evaluating hydrocarbon recovery processes. In this paper, a comprehensive review of research and growth on the hysteresis of wettability for its applications in petroleum engineering is reported. Also, theoretical and experimental investigations of hysteresis of wettability are compared and discussed in detail. The review highlights a range of concepts in existing models and experimental processes for wettability hysteresis. Furthermore, this paper tracks the current development of hysteresis and provides insight for future trends in the research. Finally, it reveals an outlook on the research challenges and weaknesses of hysteresis of wettability.

The importance of adsorption-based biochemical/biological sensors in biochemistry and biophysics is paramount. Their temporal response gives information about the presence of a biochemical/biological analyte, its concentration and its interactions with the adsorption sites (which may be an integral part of the surface itself or immobilized functionalizing molecules). Mathematical models of the temporal response taking into account as many relevant effects as possible are essential for obtaining reliable information. We present a novel model taking into account the bimodal affinity of a sensing surface (adsorption occurs on two distinct site types), and the adsorption-caused depletion of the analyte from the sample. We perform qualitative and quantitative analysis of the analyte depletion influence on the bimodal adsorption, and of the influence of the sensing surface inhomogeneity on the sensor temporal response, for different analyte concentrations and different fractions of two types of adsorption sites. Since the presented mathematical model deals with the realistic cases of the sensing surface non-uniformity and the finite amount of analyte present in the sensor reaction chamber, it enables improved accuracy in interpreting the measurement data. Our results are general, i.e. valid for any adsorption sensor (microcantilevers, plasmonics) and for arbitrary sensor dimensions.

COVID-19 dynamics is one of the most relevant subjects nowadays, and, in this regard, mathematical modeling and numerical simulations are of special interest. This paper describes COVID-19 dynamics based on a novel version of the susceptible–exposed–infectious–removed model. Removed population is split into recovered and death populations allowing a better comprehension of real situations. Besides, the total population is reduced based on the number of deaths. Hospital infrastructure is also included into the mathematical description allowing the consideration of collapse scenarios. Initially, a model verification is carried out calibrating system parameters with data from China outbreak that is considered a benchmark due the availability of data for the entire cycle. Afterward, Brazil outbreak is of concern, calibrating the model and developing numerical simulations. Results show several scenarios highlighting the importance of social isolation and hospital infrastructure. System dynamics has a strong sensitivity to transmission rate showing the importance of numerical simulations to guide public health decision strategies. Results also show that complex dynamical responses can emerge due to the oscillations of the transmission rate, being associated with distinct infection subsequent waves.

This short paper focuses on the role of mathematical models to analyze the impact of pandemics on health resources and the different trade-offs that may be included in them. There is a large body of literature suggesting that mathematical modeling may be helpful to estimate how much additional equipment and infrastructure are necessary to mitigate an increase in demand for health services during a large-scale outbreak of an infectious disease. I comment on the crucial role of these models with a special focus on their strengths and limitations.Este breve documento se centra en el papel de los modelos matemáticos para analizar el impacto de las pandemias en los recursos de salud y las diferentes trade-off que pueden estar presente. Existe una gran cantidad de literatura que sugiere que los modelos matemáticos pueden ser útiles para estimar cuánto equipo e infraestructura adicionales pueden ser necesarios para mitigar un aumento en la demanda de servicios de salud durante un brote a gran escala de una enfermedad infecciosa. Comento sobre el papel crucial de estos modelos con un enfoque especial en sus fortalezas y limitaciones.

‘Babassu’ mesocarp flour has been used by the pharmaceutical, human food and animal feed industries. However, there is lack of standardization in the production, as well as absence of information on the management of the product’s quality. Thus, the objective of this study was to dry the ‘babassu’ mesocarp in forced-air oven and solar dryer, adjust different mathematical models to the experimental data, as well as to quantify the levels of proteins and crude fiber of the produced flour. The criteria for the adjustment were the coefficient of determination, magnitude of the mean relative error, standard deviation of estimate and the residual distribution trend. Drying in the shortest time occurred in oven at 60 °C (370 min), leading to water content of 4.62%, while in the solar dryer the final water content was 8.07% in 6 days. The mathematical model Two Terms showed the best fit to the experimental data for oven drying and the Midilli model showed the best fit in solar dryer. There was an increase in protein content with the drying in solar dryer and oven at 40, 50 and 60 °C (1.36, 1.33, 1.15 and 1.37%, respectively) in relation to fresh mesocarp (0.88%). Drying in both oven and solar dryer promoted increase of protein in the flour. RESUMO A farinha do mesocarpo do babaçu tem sido utilizada pelas indústrias farmacêuticas e de alimentação humana e animal. Contudo, há falta de padronização na produção, bem como ausência de informações do manejo sobre a qualidade do produto. Deste modo, objetivou-se, no trabalho, secar o mesocarpo do babaçu em estufa de ventilação forçada de ar e secador solar, ajustar diferentes modelos matemáticos, bem como quantificar os teores de proteínas e fibras brutas da farinha produzida. Foram usados, como critério do ajuste, o coeficiente de determinação, a magnitude do erro médio relativo, o desvio-padrão da estimativa e a tendência de distribuição dos resíduos. A secagem em menor tempo ocorreu em estufa a 60 ºC (370 min) obtendo-se teor de água de 4,62%, enquanto no secador solar foi em 6 dias com teor de água final de 8,07%. O modelo Dois Termos foi o que melhor se ajustou aos dados experimentais para secagem em estufa e o modelo Midilli em secador solar. Houve um aumento do teor de proteína com a secagem em secador solar e estufa a 40, 50 e 60 ºC (1,36; 1,33; 1,15 e 1,37%, respectivamente) em relação ao mesocarpo in natura (0,88%). A secagem em estufa e em secador solar proporcionou incremento de proteína na farinha.

[EN] In this work, the fouling mechanisms that dominate the ultrafiltration of residual brines from table olive packing plant wastewaters were investigated. For that purpose, Hermia's models adapted to crossflow filtration, resistance-in-series model and a model combining intermediate blocking and cake formation mechanisms were fitted to the experimental data. Tests were performed with a 5 kDa polyethersulfone membrane at transmembrane pressures between 1 and 3 bar and crossflow velocities between 2.2 and 3.7 m s(-1). Results demonstrated that the resistance-in-series model was the most accurate to predict permeate flux evolution with time. The predominant fouling mechanism was cake formation followed by intermediate blocking/adsorption. The fouling resistances that were determined by means of the resistance in series model were tested using a well-established mathematical model proposed by Mondal and De that also combines both fouling phenomena (intermediate pore blocking and cake formation). Results demonstrated that the predicted resistances are consistent with those determined by Mondal and De's model. (C) 2016 Elsevier Ltd. All rights reserved., The authors of this work wish to gratefully acknowledge the financial support of CDTI (Centre for Industrial Technological Development) depending on the Spanish Ministry of Science and Innovation (INNPRONTA program, ITP-20111020).

This paper presents a high-fidelity electro-thermal model of a half-bridge that consists of IGBTs and anti-parallel diodes. The model calculates and estimates the half-bridge voltages, currents, switching and conduction losses considering the operating temperature and current conditions. Moreover, this model is suitable for varying switching frequency operation. The electro-thermal model can be used as an evaluation tool to analyze the performance of control strategies for traction inverter from efficiency, temperature and component stress point of view. In this paper performance of Direct Torque Model Predictive Control (DTMPC) of an Interior Permanent Magnet Synchronous Motor (IPMSM) is evaluated in comparison with Indirect Field Oriented Control (IFOC) with sinusoidal pulse width modulation (PWM). The inverter model and the MPC are both implemented in C-Mex for rapid execution. The MPC algorithm implemented in this research tracks torque reference while using Maximum-Torque-Per-Ampere (MTPA) strategy and minimizing switching losses. Both control systems are able to follow the speed reference. The MPC shows a decrease in losses compared to IFOC when tested with low-speed and high-speed parts of the WLTC profile.

In this paper, the issues related to short-circuit calculations in hybrid AC/DC microgrids are discussed. The reference standard for short-current calculations in DC systems is the IEC 61660, which provides a mathematical formulation of the problem. The standard only includes radial DC grids and does not consider a more complex system, such as meshed DC systems or a hybrid AC/DC microgrid. This paper proposes a generalized approach that can be used independently of the characteristics of the hybrid system. The proposed approach is applied to four test microgrids with different distributed sources and number of nodes and the results are compared with those obtained simulating the same grids with Neplan 360®.

Battery energy storage systems (BESS) have been extensively investigated to improve the efficiency, economy, and stability of modern power systems and electric vehicles (EVs). However, it is still challenging to widely deploy BESS in commercial and industrial applications due to the concerns of battery aging. This paper proposes an integrated battery life loss modeling and anti-aging energy management (IBLEM) method for improving the total economy of BESS in EVs. The quantification of BESS aging cost is realized by a multifactorial battery life loss quantification model established by capturing aging characteristics from cell acceleration aging tests.Meanwhile, a charging event analysis method is proposed to deploy the built life loss model in vehicle BESS management. Two BESS active anti-aging vehicle energy management models: vehicle to grid (V2G) scheduling and plug-in hybrid electric vehicle (PHEV) power distribution, are further designed, where the battery life loss quantification model is used to generate the aging cost feedback signals. The performance of the developed method is validated on a V2G peak-shaving simulation system and a hybrid electric vehicle. The work in this paper presents a practical solution to quantify and mitigate battery aging costs by optimizing energy management strategies and thus can further promote transportation electrification.

© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works This paper proposes a comprehensive analysis of the Modular Multilevel Converter (MMC) focusing on the different arm applied voltage components, that this paper will refer as degrees of freedom (DOFs), which must be considered in order to perform the internal energy balancing of the converter. The analysis relies on the commonly used differential and additive reference frames. By means of a steady-state analysis, the different voltages components applied and currents components flowing through the converter are studied and an in-depth discussion of the roles of each DOF in the converter is presented. Furthermore, the mathematical expressions of the power exchanged between the AC/DC networks and within the converter, between the arms (vertical) and among phase-legs (horizontal), are derived considering all the DOFs of the MMC, revealing potential interactions among the differential and additive quantities. Finally, the theoretical analysis is validated through comparisons between the values obtained with the mathematical expressions and the simulation results assuming different case scenarios.

Numerical simulations offer a wide range of benefits. Therefore, they are widely used in research and development. One of the biggest benefits is the possibility of automated parameter variation. This allows testing different scenarios very quickly. Nevertheless, physical experiments in the laboratory or on a test rig are still, and will remain, necessary. Physical experiments offer benefits, e.g., for very complex and/or nonlinear systems and are required for the validation of numerical models. To enhance the quality of experimental NVH investigations and to make use of the benefits of numerical simulation during experimental investigations at the same time, numerical models can be integrated into physical test rigs using the mechanical hardware-in-the-loop (mHIL) method (also referred to as real-time dynamic substructuring, hybrid testing or active control of impedance). During experimental NVH testing, the device under test (DUT) is connected to a mHIL interface which in turn actively emulates the structural dynamics of the boundary condition based on a numerical target impedance model. The goal is to have realistic contact forces instead of blocked forces at the mounting points of the DUT. This paper illustrates the development and characterization of a modular mHIL interface with high bandwidth for NVH testing of a vehicle’s front axle. The physical emulation of structural dynamics based on a target impedance model is demonstrated for synthetic test cases (e.g., emulation of different stiffness settings, or multi-resonant behavior) up to 1 kHz. Furthermore, emulation of the vehicle chassis’ structural dynamics in a single spatial direction is shown for an NVH investigation on a single-axis chassis dynamometer.

Free Energy Principle underlies a unifying framework that integrates theories of origins of life, cognition, and action. Recently, FEP has been developed into a Markovian monist perspective (Friston et al. in BC 102: 227-260, 2020). The paper expresses scepticism about the validity of arguments for Markovian monism. The critique is based on the assumption that Markovian models are scientific models, and while we may defend ontological theories about the nature of scientific models, we could not read off metaphysical theses about the nature of target systems (self-organising conscious systems, in the present context) from our theories of nature of scientific models (Markov blankets). The paper draws attention to different ways of understanding Markovian models, as material entities, fictional entities, and mathematical structures. I argue that none of these interpretations contributes to the defence of a metaphysical stance (either in terms of neutral monism or reductive physicalism). This is because scientific representation is a sophisticated process, and properties of Markovian models-such as the property of being neither physical nor mental-could not be projected onto their targets to determine the ontological properties of targets easily.

This paper studies the trending behavior of the COVID-19 dynamics in Israeli cities. The model employed is used to describe, for each city, the accumulated number of cases, the number of cases per day, and the predicted final number of cases. The innovative analysis adopted here is based on the daily evolution of the predicted final number of infections, estimated with data available until a given date. The results discussed here are illustrative for six cities in Israel, including Jerusalem and Tel Aviv. They show that the model employed fits well with the observed data and is able to suitably describe the COVID-19 dynamics in a country strongly impacted by the disease that holds one of the most successful vaccination programs in the world.

Treballs Finals del Màster d'Economia, Facultat d'Economia i Empresa, Universitat de Barcelona. Curs: 2021-2022, Tutor: Josep Maria Izquierdo Aznar; Pedro Calleja Cortes, Greenhouse gas(GHGs) emissions have resulted in global warming which further leads to climate change. To reduce GHGs emissions, governors make attempts to create multilateral agreements among countries. Their failure of establishing sustainable agreements drives researchers to find fair and equitable distribution rules. Based on Emission Egalitarianism for each individual, this paper creatively generates the generalized constraint equal awards rule (GEA), provides corresponding algorithm to compute emission allocations from the GEA rule and points out several characteristics of this rule. To determine a fairer rule, this paper introduces Lorenz dominance and proved in n-agent case that the allocation provided by the GEA rule is Lorenz-undominated by all other allocations from any other rules. Furthermore, in a simplified 2-agent case this paper confirmed the allocations derived from the GEA rule Lorenz dominates all other allocations from any other rules.

This paper introduces a new mathematical model that is used to compute either the interfacial tension of quiescent axisymmetric pendant/sessile drops and pendant/captive bubbles. This model consists of the Young–Laplace equation, that describes interface shape, together with suitable boundary conditions that guarantee a prescribed volume of drops/bubbles and a fixed position in the capillary. In order to solve the problem numerically, the Young–Laplace equation is discretized by using numerical differentiation and the numerical solutions are obtained applying the well-know Newton method. The paper contains a validation of the new methodology presented for what theoretical bubble/drops are used. Finally, some numerical results are presented for both drops and bubbles of water as well as several surfactant solutions to demonstrate the applicability, versatility and reproducibility of the proposed methodology., RSC Advances, 9 (28), ISSN:2046-2069

Locusts are short horned grasshoppers that exhibit two behaviour types depending on their local population density. These are: solitarious, where they will actively avoid other locusts, and gregarious where they will seek them out. It is in this gregarious state that locusts can form massive and destructive flying swarms or plagues. However, these swarms are usually preceded by the aggregation of juvenile wingless locust nymphs. In this paper we attempt to understand how the distribution of food resources affect the group formation process. We do this by introducing a multi-population partial differential equation model that includes non-local locust interactions, local locust and food interactions, and gregarisation. Our results suggest that, food acts to increase the maximum density of locust groups, lowers the percentage of the population that needs to be gregarious for group formation, and decreases both the required density of locusts and time for group formation around an optimal food width. Finally, by looking at foraging efficiency within the numerical experiments we find that there exists a foraging advantage to being gregarious., Author summary Locusts are short horned grass hoppers that live in two diametrically opposed behavioural states. In the first, solitarious, they will actively avoid other locusts, whereas the second, gregarious, they will actively seek them out. It is in this gregarious state that locusts form the recognisable and destructive flying adult swarms. However, prior to swarm formation juvenile flightless locusts will form marching hopper bands and make their way from food source to food source. Predicting where these hopper bands might form is key to controlling locust outbreaks. Research has shown that changes in food distributions can affect the transition from solitarious to gregarious. In this paper we construct a mathematical model of locust-locust and locust-food interactions to investigate how food distributions affect the aggregation of juvenile locusts, termed groups, an important precursor to hopper bands. Our findings suggest that there is an optimal food distribution for group formation and that being gregarious increases a locusts ability to forage when food becomes more patchy.

This paper presents experimental results in damping the pitch motion on a Surface Effect Ship (SES) in high vessel speeds in presence of regular wave. The SES is a marine craft supported by pressurized air cushion. It consists of two side-hulls, a flexible rubber bow and reinforced stern seal. The air cushion is pressurized thanks to the lift fans blowing air into the cushion. Modern SES are equipped with controllable vent valves that allows adjusting the pressure of the air cushion. Air Split Cushion SES is one of the new design by Umoe Mandal AS where the main air cushion is divided to four smaller air chambers, each one equipped with a lift fan and controllable vent-valve. Using a derivative controller, this paper presents an active pitch control in waves. Controlling the pressure in each air cushion through adjusting the air leakage on the vent-valve, provides an effective pitch regulator that demonstrates, through simulations and experiments, reduction of up to 60 % of the pitch motion in waves and high speeds. The effectiveness of the proposed system is examined through experimental model testing of the vehicle in SINTEF Ocean's towing tank.

G-protein coupled receptor (GPCR) mediated calcium (Ca2+)-signaling transduction remains crucial in designing drugs for various complex diseases including neurodegeneration, chronic heart failure as well as respiratory diseases. Although there are several reviews detailing various aspects of Ca2+-signaling such as the role of IP3 receptors and Ca2+-induced-Ca2+-release, none of them provide an integrated view of the mathematical descriptions of GPCR signal transduction and investigations on dose-response curves. This article is the first study in reviewing the network structures underlying GPCR signal transduction that control downstream [Cac2+]-oscillations. The central theme of this paper is to present the biochemical pathways, as well as molecular mechanisms underlying the GPCR-mediated Ca2+-dynamics in order to facilitate a better understanding of how agonist concentration is encoded in Ca2+-signals for Gαq, Gαs, and Gαi/o signaling pathways. Moreover, we present the GPCR targeting drugs that are relevant for treating cardiac, respiratory, and neuro-diseases. The current paper presents the ODE formulation for various models along with the detailed schematics of signaling networks. To provide a systems perspective, we present the network motifs that can provide readers an insight into the complex and intriguing science of agonist-mediated Ca2+-dynamics. One of the features of this review is to pinpoint the interplay between positive and negative feedback loops that are involved in controlling intracellular [Cac2+]-oscillations. Furthermore, we review several examples of dose-response curves obtained from [Cac2+]-spiking for various GPCR pathways. This paper is expected to be useful for pharmacologists and computational biologists for designing clinical applications of GPCR targeting drugs through modulation of Ca2+-dynamics., Highlights • Biochemical pathways underlying the GPCR mediated control of calcium dynamics. • Network structure and feedback loops present in models for calcium dynamics. • Experimental investigations proving the feedback loops in GPCR signal transduction. • Dose-response curves obtained from agonist mediated Ca2+-spiking. • Agonist concentration encoding in Ca2+ oscillations.

The cerebral vasculature has a complex and hierarchical network, ranging from vessels of a few millimeters to superficial cortical vessels with diameters of a few hundred micrometers, and to the microvasculature (arteriole/venule) and capillary beds in the cortex. In standard imaging techniques, it is difficult to segment all vessels in the network, especially in the case of the human brain. This study proposes a hybrid modeling approach that determines these networks by explicitly segmenting the large vessels from medical images and employing a novel vascular generation algorithm. The framework enables vasculatures to be generated at coarse and fine scales for individual arteries and veins with vascular subregions, following the personalized anatomy of the brain and macroscale vasculatures. In this study, the vascular structures of superficial cortical (pial) vessels before they penetrate the cortex are modeled as a mesoscale vasculature. The validity of the present approach is demonstrated through comparisons with partially observed data from existing measurements of the vessel distributions on the brain surface, pathway fractal features, and vascular territories of the major cerebral arteries. Additionally, this validation provides some biological insights: (i) vascular pathways may form to ensure a reasonable supply of blood to the local surface area; (ii) fractal features of vascular pathways are not sensitive to overall and local brain geometries; and (iii) whole pathways connecting the upstream and downstream entire-scale cerebral circulation are highly dependent on the local curvature of the cerebral sulci., Author summary Cerebral autoregulation in the complex vascular networks of the brain is an amazing achievement. We believe that numerical analysis of the cerebral blood circulation using an anatomically precise vascular model provides a powerful tool for evaluating the direct relationships between local- and global-scale blood flows. However, there is a lack of information about the overall vascular pathways in the human brain, preventing a monolithic model of the human cerebrovasculature from being established. This paper presents a multiscale model of human cerebrovasculature based on a hybrid approach that uses image-based geometries and a newly developed mathematical algorithm. One important argument of this paper is the validity of the cerebrovasculature represented in the model, which reflects anatomical features of major cerebral vasculatures and brain shape, and has strong similarities with available data for human superficial cortical vessels. Investigations of the reconstructed model allow us to derive some biological insights and associated hypotheses for the cerebral vasculature. The authors believe the present cerebrovascular model can be applied to numerical simulations of the entire-scale cerebral blood flow.

California has a range of existing and proposed targets toward a low carbon future. This paper summarizes an analytical review, focused on modeling approaches and what is known about their feasibility and cost. The findings in this paper are based on the Climate Change Policy Modeling (CCPM) forum, which included modelers, policy makers and stakeholders evaluating targets and pathways to low-carbon futures and identifying required policies to achieve goals. The third forum, CCPM-3, was on May 14th, 2018, at the University of California, Davis and provided critical discussion and a gathering of the key experts in this topic area This report builds on the findings of CCPM and integrates with other literature where possible. It includes a review of the CO2-relevant targets, discussion of studies and modeling efforts to assess meeting such targets, including feasibility and cost. This includes analysis in the transportation and energy sectors, as well as land use and carbon sequestration.

Clinical trials covering the immunogenicity of a vaccine aim to study the longitudinal dynamics of certain immune cells after vaccination. The corresponding immunogenicity datasets are mainly analyzed by the use of statistical (mixed effects) models. This paper proposes the use of mathematical ordinary differential equation (ODE) models, combined with a mixed effects approach. ODE models are capable of translating underlying immunological post vaccination processes into mathematical formulas thereby enabling a testable data analysis. Mixed models include both population-averaged parameters (fixed effects) and individual-specific parameters (random effects) for dealing with inter- and intra-individual variability, respectively. This paper models B-cell and T-cell datasets of a phase I/II, open-label, randomized, parallel-group study (NCT00492648) in which the immunogenicity of a new Herpes Zoster vaccine (Shingrix) is compared with the original Varicella Zoster Virus vaccine (Varilrix). Since few significant correlations were found between the B-cell and T-cell datasets, each dataset was modeled separately. By following a general approach to both the formulation of several different models and the procedure of selecting the most suitable model, we were able to propose a mathematical ODE mixed-effects model for each dataset. As such, the use of ODE-based mixed effects models offers a suitable framework for handling longitudinal vaccine immunogenicity data. Moreover, this approach allows testing for differences in immunological processes between vaccines or schedules. We found that the Shingrix vaccination schedule led to a more pronounced proliferation of T-cells, without a difference in T-cell decay rate compared to the Varilrix vaccination schedule. (C) 2019 Elsevier Ltd. All rights reserved. This research was funded by the University of Antwerp [BOF Concerted Research Action, Methusalem funding], NH acknowledges support from the chair in evidence-based vaccinology sponsored by a gift from Pfizer (2009-2018) and GSK (2016) and from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement 682540 - TransMID). This research was supported by the Antwerp Study Centre for Infectious Diseases (BID). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Large-scale electric aircraft is a disruptive technology to address the environmental impact of air travel. Fault current limitation is crucial to realise the safety and reliability of the electric aircraft, in particular for large-scale electric aircraft using DC distribution network. This paper investigates the behavior of the resistive SFCL under different cryogenic cooling systems including liquid nitrogen and helium gas circulation cooling systems for the electric aircraft DC distribution network. Electromagnetic and thermoelectric models were used to predict the characteristics of resistive SFCL. The simulation results demonstrate that it is promising to design resistive SFCL using liquid nitrogen cooling as well as helium gas circulation cooling systems, which offer flexibility for SFCL cryogenic cooling system for electric aircraft applications.

The paper presents an overview of the final results of the 7FP ICT-EMISSIONS project that developed and validated a novel methodology and tool set to evaluate the impact of ICT-related transport measures on mobility and CO2 emissions of vehicle fleets under real-world conditions. The methodology combines traffic and emission modelling at micro and macro scales. The integration of these scales is an important feature because a measure to influence the behaviour of single vehicles may have an impact on the whole network, while traffic management at the network level may influence the behaviour of the single vehicles. The paper presents results of a number of ITS systems including Variable Speed Limit (VSL), Green Navigation (GN), Urban Traffic Control (UTC), Ecodriving and Adaptive Cruise Control Systems (ACC). These measures have been tested for concrete application cases implemented in the cities of Turin, Madrid and Rome. Starting point were real-world data collected by means of floating cars. The investigations have taken into account different penetration rates of ICT measures, as well as different traffic conditions (e.g. free flow, congested). Each case has been modelled for the current and at least on future fleet composition. The results indicate that ITS are overall able to contribute to CO2 emissions reduction by several percent points; the effects, nevertheless, are different depending on local conditions. The CO2 benefit is also found to be constrained by the penetration rates of the on-road ITS equipped vehicles: as this share increases a maximum is reached at up to 50% penetration rate and under non-congested conditions.

This paper introduces a time-since-recovery structured, multi-strain, multi-population model of avian influenza. Influenza A viruses infect many species of wild and domestic birds and are classified into two groups based on their ability to cause disease: low pathogenic avian influenza (LPAI) and high pathogenic avian influenza (HPAI). Prior infection with LPAI provides partial immunity towards HPAI. The model introduced in this paper structures LPAI-recovered birds (wild and domestic) with time-since-recovery and includes cross-immunity towards HPAI that can fade with time. The model has a unique disease-free equilibrium (DFE), unique LPAI-only and HPAI-only equilibria and at least one coexistence equilibrium. We compute the reproduction numbers of LPAI ( $ {\mathcal R}_{\rm L} $ ) and HPAI ( $ {\mathcal R}_{\rm H} $ ) and show that the DFE is locally asymptotically stable when $ {\mathcal R}_{\rm L} 1 $ ( $ {\mathcal R}_{\rm H} >1 $ ) and it is locally asymptotically stable if HPAI (LPAI) cannot invade the equilibrium, that is, if the invasion number $ \hat {\mathcal {R}}_{\rm L}^{\rm H}

This note first summarizes the history of the manuscript "On a Continuum Model for Avalanche Flow and Its Simplified Variants" by Grigorian and Ostroumov―published in the Special Issue on snow avalanche dynamics of Geosciences―since the early 1990s and explains the guiding principles in editing it for publication. The changes are then detailed and some explanatory notes given for the benefit of readers who are not familiar with the early Russian work on snow avalanche dynamics. Finally, the editor's personal views as to why he still considers this paper of relevance for avalanche dynamics research today are presented in brief essays on key aspects of the paper, namely the role of simple and complex models in avalanche research and mitigation work, the status and possible applications of Grigorian's stress-limited friction law, and non-monotonicity of the dynamics of the Grigorian–Ostroumov model in the friction coefficient. A comparison of the erosion model proposed by those authors with two other models suggests to enhance it with an additional equation for the balance of tangential momentum across the shock front. A preliminary analysis indicates that continuous scouring entrainment is possible only in a restricted parameter range and that there is a second erosion regime with delayed entrainment.

The increasing penetration of renewables in power systems reconfigures the generation mix and geography distribution, resulting in more frequent power flow congestion. Conventionally, a relatively conservative dispatch margin for transmission congestion in network constraints was reserved to ensure safe operation due to potential deviations introduced by DC power flow modeling and conservative line rating. This paper proposes a real-time power market clearing model with improved network constraints considering power transfer distribution factor (PTDF) correction and fast-calculated dynamic line rating. The clearing model based on PTDF correction is proposed first employing the Taylor expansion with the voltage and phase angle approximation. An improved dynamic line rating model is further applied into the clearing model based on the piecewise linear approximation method, which calculates real-time conductor temperature faster with sufficient precision. We test and verify the validity of the proposed model based on three independent systems including the IEEE 39-bus system, the IEEE 2383-bus system, and the real power grid system in Yunnan province of China, respectively. The results show that the improved clearing model reduces the calculated power flow deviation between the clearing results and real conditions compared with traditional security constraints, where the efficiency of power grid operation is also increased.

Influenza A virus (IAV) infection represents a global threat causing seasonal outbreaks and pandemics. Additionally, secondary bacterial infections, caused mainly by Streptococcus pneumoniae, are one of the main complications and responsible for the enhanced morbidity and mortality associated with IAV infections. In spite of the significant advances in our knowledge of IAV infections, holistic comprehension of the interplay between IAV and the host immune response (IR) remains largely fragmented. During the last decade, mathematical modeling has been instrumental to explain and quantify IAV dynamics. In this paper, we review not only the state of the art of mathematical models of IAV infection but also the methodologies exploited for parameter estimation. We focus on the adaptive IR control of IAV infection and the possible mechanisms that could promote a secondary bacterial coinfection. To exemplify IAV dynamics and identifiability issues, a mathematical model to explain the interactions between adaptive IR and IAV infection is considered. Furthermore, in this paper we propose a roadmap for future influenza research. The development of a mathematical modeling framework with a secondary bacterial coinfection, immunosenescence, host genetic factors and responsiveness to vaccination will be pivotal to advance IAV infection understanding and treatment optimization.

This is the accepted manuscript of the paper "Modeling the dispersion of viable and total Escherichia coli cells in the artificial semi-enclosed bathing area of Santa Marinella (Latium, Italy)", published as final paper in "Marine Pollution Bulletin 95 (2015) 141–154;https://doi.org/10.1016/j.marpolbul.2015.04.030" Bonamano S, Madonia A, Borsellino C, Stefanì C, Caruso G, De Pasquale F, Piermattei V, Zappalà G, Marcelli M (2015). Modeling the dispersion of viable and total Escherichia coli cells in the artificial semi-enclosed bathing area of Santa Marinella (Latium, Italy). MARINE POLLUTION BULLETIN, ISSN: 0025-326X, doi: 10.1016/j.marpolbul.2015.04.030. Coastal areas are strongly affected by episodes of fecal contamination due to polluted water inflows from inadequately treated sewages. The present study aims to investigate the dispersion of Escherichia coli in the artificial semi-enclosed bathing area of Santa Marinella (Latium, Italy) through in situ samplings carried out in summer 2012 and the application of a dynamic model. Collected samples were analyzed by the Culture-Based technique and the Fluorescent Antibody method in order to estimate both the viable culturable cells and the total E. coli population, respectively. The in situ datasets were used to test the proposed modeling approach and simulate the behavior of bacteria as particles subjected, or not, to decay. Next, the flushing time and the computation of the Microbiological Potential Risk Area allowed the evaluation of the contribution of physical and biological processes to coliform dispersion and the related potential risk for bathers.

© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works This paper proposes an optimization-based size reduction methodology for Modular Multilevel Converters (MMC), focusing on minimizing the converter's sub-module capacitor CSM. The analysis is performed considering both the converter's current and voltage limitations and the Transmission System Operator (TSO) Fault Ride Through (FRT) requirements. By means of a steady-state analysis, the time-domain expressions of the converter's arms energies are obtained and their behavior throughout the MMC's operating range is shown. Based on these expressions, the optimization-based problem to reduce the CSM size is developed and its constraints are imposed to ensure that the converter's voltage and current levels are within its design limitations. The suggested method is compared with different approaches for distinct active and reactive power set-points, where it is shown that the SM capacitor size can be reduced up to 24% in comparison with the method with worst performance and up to 7% regarding the best method used for comparison purposes. Furthermore, time-domain simulations of the MMC considering several AC voltage sags are performed in order to demonstrate that the dynamics of the SM capacitor and the arm applied voltages are within acceptable margins during the different operations.

Cyber-physical system security for electric distribution systems is critical. In direct switching attacks, often coordinated, attackers seek to toggle remote-controlled switches in the distribution network. Due to the typically radial operation, certain configurations may lead to outages and/or voltage violations. Existing optimization methods that model the interactions between the attacker and the power system operator (defender) assume knowledge of the attacker's parameters. This reduces their usability. Furthermore, the trend with coordinated cyberattack detection has been the use of centralized mechanisms, correlating data from dispersed security systems. This can be prone to single point failures. In this paper, novel mathematical models are presented for the attacker and the defender. The models do not assume any knowledge of the attacker's parameters by the defender. Instead, a machine learning (ML) technique implemented by a multi-agent system correlates detected attacks in a decentralized manner, predicting the targets of the attacker. Furthermore, agents learn optimal mitigation of the communication level through Q-learning. The learned attacker motive is also used by the defender to determine a new configuration of the distribution network. Simulations of the technique have been performed using the IEEE 123-Node Test Feeder. The simulation results validate the capability and performance of the algorithm. U.S. National Science Foundation [1837359]; Commonwealth Cyber Initiative (CCI), State of Virginia [PR6ZBSTA, 5GPG] Published version This work was supported in part by the U.S. National Science Foundation under Grant 1837359; and in part by the projects under Grant PR6ZBSTA and Grant 5GPG sponsored by Commonwealth Cyber Initiative (CCI), State of Virginia.

In business replenishment, discount offers of multi-item may either provide different discount schedules with a single discount type, or provide schedules with multiple discount types. The paper investigates the joint effects of multiple discount schemes on the decisions of multi-item joint replenishment. In this paper, a joint replenishment problem (JRP) model, considering three discount (all-unit discount, incremental discount, total volume discount) offers simultaneously, is constructed to determine the basic cycle time and joint replenishment frequencies of multi-item. To solve the proposed problem, a heuristic algorithm is proposed to find the optimal solutions and the corresponding total cost of the JRP model. Numerical experiment is performed to test the algorithm and the computational results of JRPs under different discount combinations show different significance in the replenishment cost reduction.

Passive photonic integrated circuits (PICs) can be easily characterized in the frequency-domain, but their accurate time-domain performance evaluation is a hurdle for system-level designers, especially when dealing with resonant circuits having highly dispersive behavior, such as ring resonators. In this paper, a new equivalent circuit modeling and simulation approach is proposed, based on the Complex Vector Fitting algorithm, able to perform accurate and robust time-domain simulations of passive PICs directly in standard SPICE simulators. The proposed modeling technique starts from scattering parameters of passive PICs, and is able to capture linear and high order dispersion, backscattering, and wavelength dependent effects. Considering the different nature of optical and electronic signals, a novel concept of equivalent voltage and current for optical waveguides is proposed to simplify the optical to electronic ports conversion and to make it possible to connect and terminate the equivalent circuit models as needed in SPICE simulators, natively supporting bidirectional signal propagation in a waveguide. This work provides a precise and reliable solution to evaluate time-domain characteristics of passive PICs and to access any internal nodes within a circuit, such as the signals inside a ring resonator. Three examples of time-domain simulations of passive PICs in commercial SPICE simulators are presented to demonstrate the flexibility and advantages of the proposed technique.

Classifying bank accounts by using transaction data is encouraging in cracking down on illegal financial activities. However, few research simultaneously use heterogenous features, which are embedded in the time series data. In this paper, a two route convolution neural network TRHD-CNN model, fed with two types of heterogeneous feature matrices, is proposed for classifying the bank accounts. TRHD-CNN adopts divide and conquer strategy to extract characteristics from two types of data source independently. The strategy is proved able in mining complementary classification characteristics. We firstly transfer the original log data into a directed and dynamic transaction network. On the basis of that, two feature generation methods are devised for extracting information from local topological structure and time series transaction respectively. A DirectedWalk method is developed in this paper to learning the network vector of vertices used for embedding the neighbor relationship of bank account. The extensive experimental results, conducted on a real bank transaction dataset that contains illegal pyramid selling accounts, show the significant advantage of TRHD-CNN over the existing methods. TRHD-CNN can provide recall scores up to 5.15% higher than competing methods. In addition, the two-route architecture of TRHD-CNN is easy to extend to multi-route scenarios and other fields.

With the development of computer network bandwidth, packet classification algorithms which are able to deal with large-scale rule sets are in urgent need. Among the existing algorithms, researches on packet classification algorithms based on hierarchical trie have become an important packet classification research branch because of their widely practical use. Although hierarchical trie is beneficial to save large storage space, it has several shortcomings such as the existence of backtracking and empty nodes. This paper proposes a new packet classification algorithm, Hierarchical Trie Algorithm Based on Expectation-Maximization Clustering (HTEMC). Firstly, this paper uses the formalization method to deal with the packet classification problem by means of mapping the rules and data packets into a two-dimensional space. Secondly, this paper uses expectation-maximization algorithm to cluster the rules based on their aggregate characteristics, and thereby diversified clusters are formed. Thirdly, this paper proposes a hierarchical trie based on the results of expectation-maximization clustering. Finally, this paper respectively conducts simulation experiments and real-environment experiments to compare the performances of our algorithm with other typical algorithms, and analyzes the results of the experiments. The hierarchical trie structure in our algorithm not only adopts trie path compression to eliminate backtracking, but also solves the problem of low efficiency of trie updates, which greatly improves the performance of the algorithm.

This paper presents a novel method on the optimization of bi-objective Flexible Job-shop Scheduling Problem (FJSP) under stochastic processing times. The robust counterpart model and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) are used to solve the bi-objective FJSP with consideration of the completion time and the total energy consumption under stochastic processing times. The case study on GM Corporation verifies that the NSGA-II used in this paper is effective and has advantages to solve the proposed model comparing with HPSO and PSO+SA. The idea and method of the paper can be generalized widely in the manufacturing industry, because it can reduce the energy consumption of the energy-intensive manufacturing enterprise with less investment when the new approach is applied in existing systems.

[eng] In this thesis I investigated the status of the Mediterranean Sea ecosystem and the sustainability of its marine resources using an interdisciplinary approach, which combined data integration and modelling approaches. Results highlighted a series of commonalities for Mediterranean marine ecosystems: they indicate that ‘small pelagic fishes’, mainly European pilchards and anchovies, both with high biomasses and high proportions in catches, are important structuring species for the Mediterranean ecosystem (at regional, sub-regional and local scales). ‘Large pelagic fishes’ are the main keystone species for both the past and current Mediterranean ecosystem configuration, while ‘sharks’ and ‘medium pelagic fishes’ played a key role in the past, but their ecological role is currently replaced by benthopelagic and benthic cephalopods. In addition, the ‘Mediterranean monk seal’ “Monachus monachus”, where it still occurs, is the species with the highest TL followed by ‘piscivorous cetaceans’ and ‘large pelagic fish’. Looking at temporal ecosystem dynamics, biomass trends and ecological indicators (e.g., community biomass, trophic levels of the community, catch and diversity indicators) reveal that the combined effect of excessive fishing pressure and changes in primary productivity altered the Mediterranean marine ecosystem over time, especially reducing the proportions of top predators (e.g., pinnipeds, large pelagic fish) and mid trophic level organisms (e.g., small pelagic fishes) and increasing the abundance of groups at lower trophic levels (e.g., invertebrates). The Western and the Adriatic Seas are the most degraded ecosystems with biomasses declines among all the species compartments assessed (from forage fish to sharks/rays and skates, except for invertebrates that remained stable in time). The Ionian Sea was found to be the area with less biomass changes historically in comparison with available survey data. Even at a more local scale (Amvrakikos Gulf), both ecological indicators and biomass trends highlight a degradation of the demersal compartments of the food web but a relative stability of the pelagic ones mainly due to high eutrophication levels. Fishing pressure and changes in primary production (PP) play an important role in driving species temporal dynamics; yet, PP seems to be the strongest driver upon the Mediterranean Sea ecosystem. Fisheries data (mainly catch and effort) are found to be under-reported and under-estimated at regional, sub-regional and local scale. For example, fishing mortalities (and so landings data obtained from Food and Agriculture Organization [FAO] fisheries statistics) of three most important commercial species (European pilchard ‘Sardina pilchardus’, anchovy ‘Engraulis encrasicolus’ and hake ‘Merluccius merluccius’) were in fact observed in early decades (1950s), in all the Mediterranean sub-regions, between 5 and 10 times inferior from the average reference values reported in stock assessment for these fish stocks in the Mediterranean Sea. Even in the assessment of the Italian fisheries, the reconstructed of total catches were 2.6 times the landings officially reported by the FAO on behalf of Italy for the same period and same area, with unreported commercial landings (from both industrial and artisanal sectors) contributing 50% to the total catch (in relation to FAO reporting) and discards contributing another 7%. In Europe, several models and associated indicators exist that could be used in support of European policies (MSFD); yet, Ecopath with Ecosim (EwE) is the most applied tool for modelling marine and aquatic ecosystems and the one that can produce the largest number of indicators useful for the Marine Strategy Framework Directive (MSFD). Since anthropogenic pressures are rapidly expanding in the basin, this work constitutes an important first step to advance further in the regional assessment of the Mediterranean Sea ecosystem and to inform conservation plans and management actions., [cat] En aquesta tesi he investigat l'estat ambiental del mar mediterrani i la sostenibilitat dels seus recursos marins mitjançant un enfoc interdisciplinari que combina la integració de dades i la modelització d'ecosistemes. Els resultats posen en relleu una sèrie de punts en comú dels ecosistemes marins mediterranis: el grup de "peixos pelàgics de mida petita", principalment compost per sardines i seitons, amb grans biomasses i captures, és un grup important en relació amb l'estructura de l'ecosistema mediterrani (tant a nivell regional, sub regional i a escales locals). El grup de “peixos pelàgics de gran mida” destaca per ser important com a grup clau de l'ecosistema, tant en el passat com en el present, mentre que el grup dels “taurons” i “peixos pelàgics de mida mitjana” han jugat un paper ecològic clau en el passat, però aquest és actualment reemplaçat pels grups de peixos bentopelàgicos i cefalòpodes bentònics. A més, el vell marí del mediterrani “Monachus monachus”, en aquelles zones on encara existeix, és l'espècie amb el nivell tròfic més alt, seguida pel grup de "cetacis que s'alimenten de peixos" i "peixos pelàgics de grans dimensions". Pel que fa a la dinàmica temporal de l'ecosistema, les tendències de la biomassa i dels indicadors ecològics (per exemple, la biomassa de la comunitat, els nivells tròfics de la comunitat, les captures i els indicadors de diversitat) revelen que l'efecte combinat d’una pressió pesquera excessiva i els canvis en la productivitat primària ha alterat l'ecosistema marí mediterrani a través del temps, especialment pel que fa a una reducció de les proporcions dels depredadors superiors (per exemple, pinnípedes, i peixos pelàgics de grans dimensions) i organismes de nivells tròfics mitjans (per exemple, peixos pelàgics de mida petita), i l'augment en abundància de grups d'organismes en nivells tròfics inferiors (per exemple, invertebrats). El mar mediterrani occidental i el mar adriàtic són els ecosistemes més degradats amb baixades de biomasses per a totes les espècies avaluades (des dels peixos pelàgics de mida petita als taurons i ratjades, amb excepció dels invertebrats que es mantenen estables en el temps). El mar jònic és l'àrea amb menys canvis històrics en termes de biomassa en comparació amb les dades disponibles de mostrejos. Fins i tot a una escala més local (en el Golf de Amvrakikos), tant els indicadors ecològics com les biomasses evidencien una degradació dels compartiments demersals de la xarxa tròfica, encara que s'observa una relativa estabilitat dels compartiments pelàgics, principalment a causa dels alts nivells d'eutrofització. La pressió pesquera elevada i els canvis en la producció primària (PP) juguen un paper important en la dinàmica temporal de les espècies; però, els canvis en la PP semblen ser els principals impulsors de la dinàmica temporal de l'ecosistema del mar mediterrani. Les dades pesquers (principalment la captura i l'esforç pesquer) es troben subestimats i conseqüentment registrats de forma errònia a escala regional, sub regional i local. Per exemple, la mortalitat per pesca (i per tant les dades de desembarcament que s'obtenen de les estadístiques de pesca de l'Organització per a l'Agricultura i l'Alimentació [FAO]) de tres de les espècies comercials més importants (Sardina europea “Sardina pilchardus”, anxova “Engraulis encrasicolus” i lluç “Merluccius merluccius”) per a les primeres dècades d'aquest estudi (1950), i en totes les sub regions mediterrànies analitzades, era entre 5 i 10 vegades inferior als valors de referència mitjana registrats en avaluacions de l'estoc d'aquestes poblacions al mar mediterrani. Fins i tot en l'avaluació de les pesqueries italianes, la reconstrucció de les captures totals mostra que les captures totals són 2,6 vegades més grans que els desembarcaments registrats oficialment per la FAO durant el mateix període i per la mateixa zona, amb desembarcaments comercials no declarats (dels sectors industrials i artesanals) que contribueixen al 50% de la captura total (en relació als informes de la FAO) i els descarts que contribueixen un altre 7%. A Europa hi ha diversos models i indicadors associats que podrien ser utilitzats en suport de les polítiques europees de gestió mediambiental, com la Directiva Marc sobre l'Estratègia Marina (MSFD); de totes formes, Ecopath with Ecosim (EwE) és l'eina més aplicada per a la modelització dels ecosistemes marins i aquàtics i la que pot produir un major nombre d'indicadors útils per a la MSFD. Atès que les pressions antropogèniques s'estan expandint ràpidament a la conca mediterrània, aquest treball constitueix un primer pas important per avançar en l'avaluació regional de l'estat ambiental de l'ecosistema marí mediterrani i per informar els plans de conservació i gestió presents i futurs.

This is the accepted manuscript of the paper "The Civitavecchia Coastal Environment Monitoring System (C-CEMS): a new tool to analyse the conflicts between coastal pressures and sensitivity areas", published as final paper in "Ocean Sci., 12, 87–100, 2016 https://doi.org/10.5194/os-12-87-2016"https://www.ocean-sci.net/12/87/2016/ Bonamano, S., Piermattei, V., Madonia, A., Paladini de Mendoza, F., Pierattini, A., Martellucci, R., Stefanì, C., Zappalà, G., Caruso, G., and Marcelli, M.: The Civitavecchia Coastal Environment Monitoring System (C-CEMS): a new tool to analyze the conflicts between coastal pressures and sensitivity areas, Ocean Sci., 12, 87–100, https://doi.org/10.5194/os-12-87-2016, 2016. The understanding of the coastal environment is fundamental for efficiently and effectively facing the pollution phenomena as expected by the Marine Strategy Framework Directive, and for limiting the conflicts between anthropic activities and sensitivity areas, as stated by Maritime Spatial Planning Directive. To address this, the Laboratory of Experimental Oceanology and Marine Ecology developed a multi-platform observing network that has been in operation since 2005 in the coastal marine area of Civitavecchia (Latium, Italy) where multiple uses and high ecological values closely coexist. The Civitavecchia Coastal Environment Monitoring System (C-CEMS), implemented in the current configuration, includes various components allowing one to analyze the coastal conflicts by an ecosystem-based approach. The long-term observations acquired by the fixed stations are integrated with in situ data collected for the analysis of the physical, chemical and biological parameters of the water column, sea bottom and pollution sources detected along the coast. The in situ data, integrated with satellite observations (e.g., temperature, chlorophyllaand TSM), are used to feed and validate the numerical models, which allow the analysis and forecasting of the dynamics of pollutant dispersion under different conditions. To test the potential capabilities of C-CEMS, two case studies are reported here: (1) the analysis of fecal bacteria dispersion for bathing water quality assessment, and (2) the evaluation of the effects of the dredged activities onPosidoniameadows, which make up most of the two sites of community importance located along the Civitavecchia coastal zone. The simulation outputs are overlapped by the thematic maps showing bathing areas andPosidonia oceanicadistribution, thus giving a first practical tool that could improve the resolution of the conflicts between coastal uses (in terms of stress produced by anthropic activities) and sensitivity areas. &nbsp

Introduction It is increasingly clear that the HIV response will not be sustainable if the number of infections is not significantly reduced. Discussion For two decades, research has been ongoing to identify new behavioural and biomedical strategies to prevent HIV infection. In the past few years, the efficacy of several new strategies has been demonstrated, including oral pre-exposure prophylaxis (PrEP; i.e. daily use of tenofovir/emtricitabine). Because several social, political and logistic barriers remain, however, optimal PrEP implementation will require a better dissemination of new evidence in a number of areas and additional implementation research from various disciplinary perspectives (i.e. social science, policy and ethics; health systems; and economics, including cost-effectiveness studies). Discussion of new evidence on those topics, as well as case studies of potential PrEP implementation in diverse environments, can improve the understanding of the role that PrEP may play in addressing the global HIV/AIDS epidemic. In light of these needs, the Network for Multidisciplinary Studies in ARV-based HIV Prevention (NEMUS) and the World Health Organization (WHO) were honoured to co-organize a special issue of JIAS aimed at contributing to a scholarly discussion of current conditions surrounding PrEP implementation, potential impact and efficiency, social science concerns and the study of PrEP implementation in specific country cases. The papers included in this monograph identify and cover many of the main aspects of the complex yet promising discussions around PrEP implementation today. Conclusions This is a collection of timely contributions from global leaders in HIV research and policy that addresses geographic diversity, uses a trans-disciplinary approach and covers a variety of the complex issues raised by PrEP. As this publication will become accessible to all, we hope that it will remain a valuable resource for policy makers, programme managers, researchers and activists around the world at a moment of a paradigm shift of the global response to HIV., Introduction Towards the end of the twentieth century, significant success was achieved in reducing incidence in several global HIV epidemics through ongoing prevention strategies. However, further progress in risk reduction was uncertain. For one thing, it was clear that social vulnerability had to be addressed, through research on interventions addressing health systems and other structural barriers. As soon as antiretroviral treatment became available, researchers started to conceive that antiretrovirals might play a role in decreasing either susceptibility in uninfected people or infectiousness among people living with HIV. In this paper we focus on the origin, present status, and potential contribution of pre-exposure prophylaxis (PrEP) within the combination HIV prevention framework. Discussion After a phase of controversy, PrEP efficacy trials took off. By 2015, daily oral PrEP, using tenofovir alone or in combination with emtricitabine, has been proven efficacious, though efficacy seems heavily contingent upon adherence to pill uptake. Initial demonstration projects after release of efficacy results have shown that PrEP can be implemented in real settings and adherence can be high, leading to high effectiveness. Despite its substantial potential, beliefs persist about unfeasibility in real-life settings due to stigma, cost, adherence, and potential risk compensation barriers. Conclusions The strategic synergy of behavioural change communication, biomedical strategies (including PrEP), and structural programmes is providing the basis for the combination HIV prevention framework. If PrEP is to ever become a key component of that framework, several negative beliefs must be confronted based on emerging evidence; moreover, research gaps regarding PrEP implementation must be filled, and appropriate prioritization strategies must be set up. Those challenges are significant, proportional to the impact that PrEP implementation may have in the global response to HIV., Introduction To be used most effectively, pre-exposure prophylaxis (PrEP) should be prioritized to those at high risk of acquisition and would ideally be aligned with time periods of increased exposure. Identifying such time periods is not always straightforward, however. Gaza Province in southern Mozambique is characterized by high levels of HIV transmission and circular labour migration to mines in South Africa. A strong seasonal pattern in births is observable, reflecting an increase in conception in December. Given the potential for increased HIV transmission between miners returning in December and their partners in Gaza Province, PrEP use by the latter would be a useful means of HIV prevention, especially for couples who wish to conceive. Methods A mathematical model was used to represent population-level adult heterosexual HIV transmission in Gaza Province. Increased HIV acquisition among partners of miners in December, coinciding with the miners’ return from South Africa, is represented. In addition to a PrEP intervention, the scale-up of treatment and recent scale-up of male circumcision that have occurred in Gaza are represented. Results Providing time-limited PrEP to the partners of migrant miners, as opposed to providing PrEP all year, would improve the cost per infection averted by 7.5-fold. For the cost per infection averted to be below US$3000, at least 85% of PrEP users would need to be good adherers and PrEP would need to be cheaper than US$115 per person per year. Uncertainty regarding incidence of HIV transmission among partners of miners each year in December has a strong influence on estimates of cost per infection averted. Conclusions Providing time-limited PrEP to partners of migrant miners in Gaza Province during periods of increased exposure would be a novel strategy for providing PrEP. This strategy would allow for a better prioritized intervention, with the potential to improve the efficiency of a PrEP intervention considerably, as well as providing important reproductive health benefits., Introduction Despite scale-up of antiretroviral therapy (ART) for treating HIV-positive persons, HIV incidence remains elevated among those at high risk such as persons in serodiscordant partnerships. Antiretrovirals taken by HIV-negative persons as pre-exposure prophylaxis (PrEP) has the potential to avert infections in individuals in serodiscordant partnerships. Evaluating the cost-effectiveness of implementing time-limited PrEP as a short-term bridge during the first six months of ART for the HIV-positive partner to prevent HIV transmission compared to increasing ART coverage is crucial to informing policy-makers considering PrEP implementation. Methods To estimate the real world delivery costs of PrEP, we conducted micro-costing and time and motion analyses in an open-label prospective study of PrEP and ART delivery targeted to high-risk serodiscordant couples in Uganda (the Partners Demonstration Project). The cost (in USD, in 2012) of PrEP and ART for serodiscordant couples was assessed, with and without research components, in the study setting. Using Ministry of Health costs, the cost of PrEP and ART provision within a government programme was estimated, as was the cost of providing PrEP in addition to ART. We parameterized an HIV transmission model to estimate the health and economic impacts of 1) PrEP and ART targeted to high-risk serodiscordant couples in the context of current ART use and 2) increasing ART coverage to 55% of HIV-positive persons with CD4 ≤500 cells/µL without PrEP. The incremental cost-effectiveness ratios (ICERs) per HIV infection and disability-adjusted life year (DALY) averted were calculated over 10 years. Results The annual cost of PrEP and ART delivery for serodiscordant couples was $1058 per couple in the study setting and $453 in the government setting. The portion of the programme cost due to PrEP was $408 and $92 per couple per year in the study and government settings, respectively. Over 10 years, a programme of PrEP and ART for high-risk serodiscordant couples was projected to avert 43% of HIV infections compared to current practice with an ICER of $1340 per infection averted. This was comparable to ART expansion alone, which would avert 37% of infections with an ICER of $1452. Conclusions Using Uganda's gross domestic product per capita of $1681 as a threshold, PrEP and ART for high-risk persons have the potential for synergistic action and are cost-effective in preventing HIV infections in high prevalence settings. The annual cost of PrEP in this programme is less than $100 per serodiscordant couple if implemented in public clinics., Social scientists have much to contribute to the analysis of the real and potential contribution of pre-exposure prophylaxis (PrEP) to HIV prevention around the world. Beyond just a matter of clinical efficacy and getting pills into people's mouths, PrEP raises a number of important social-psychological questions that must be attended to in order to translate biomedical and clinical findings into uptake of PrEP among enough people at risk of HIV infection to produce population-level effectiveness. PrEP is a dynamic phenomenon with “dialectical” attributes that invite both optimism and cynicism as a desirable and effective HIV prevention strategy. PrEP disrupts traditional notions of “safe” and “unsafe” sex; it confers on its users a level of agency and control not generally achieved with condoms; and it affects sexual practices and sexual cultures in meaningful ways. As these dynamics play out in different contexts, and as new modes of PrEP administration emerge, it will be important for social scientists to be engaged in assessing their impact on PrEP implementation and effectiveness., Introduction Southern and Eastern Africa bear the brunt of the AIDS epidemic, and current prevention interventions remain inadequate. Antiretroviral-based pre-exposure prophylaxis (PrEP) is gaining momentum as an effective prevention intervention. Discussion Discussions have been started on how this strategy could be employed in Africa such that the populations most in need can be reached urgently for the greatest impact. This requires the selection of specific risk groups and service environments in which PrEP can be distributed safely and cost effectively while being mindful of any ethical issues. Conclusions Given the need for an integrated public health approach to this, a number of potential populations and opportunities for PrEP distribution exist and are discussed in this commentary., Introduction Pre-exposure prophylaxis (PrEP) is recommended by the World Health Organization as an effective method of HIV prevention for individuals at risk for infection. In this paper, we describe the unique role that Thailand has played in the global effort to combat the HIV epidemic, including its role in proving the efficacy of PrEP, and discuss the opportunities and challenges of implementing PrEP in a middle-income country. Discussion Thailand was one of the first countries in the world to successfully reverse a generalized HIV epidemic. Despite this early success, HIV prevalence has remained high among people who inject drugs and has surged among men who have sex with men (MSM) and transgender women (TGW). Two pivotal trials that showed that the use of oral antiretroviral medication as PrEP can reduce HIV transmission were conducted partially or entirely at Thai sites. Demonstration projects of PrEP, as well as clinical trials of alternative PrEP regimens, began or will begin in 2014–2015 in Thailand and will provide additional data and experience on how to best implement PrEP for high-risk individuals in the community. Financing of drug costs, the need for routine laboratory monitoring and lack of awareness about PrEP among at-risk groups all present challenges to the wider implementation of PrEP for HIV prevention in Thailand. Conclusions Although significant challenges to wider use remain, PrEP holds promise as a safe and highly effective method to be used as part of a combined HIV prevention strategy for MSM and TGW in Thailand., Introduction The World Health Organization recently released guidelines on the use of pre-exposure prophylaxis (PrEP) for prevention of HIV infection among men and transgender women (TGW) who have sex with men based on results of randomized clinical trials. The aim of this commentary is to discuss the opportunities and challenges of incorporating PrEP into the Brazilian continuum of HIV care and prevention for men who have sex with men (MSM) and TGW. Discussion Key aspects of the AIDS epidemic among MSM and TGW in Brazil and the comprehensive Brazilian response to the epidemic are presented. The universal access to health care provided through the Brazilian Unified Health System (SUS) and the range of prevention and care services already available countrywide to HIV-positive individuals and at-risk MSM and TGW are identified as the main facilitators for the implementation of PrEP. Limited PrEP awareness among MSM, TGW and health care providers, low HIV testing frequency and low HIV risk perception among MSM and TGW represent the core challenges to be addressed. Data generated by demonstration projects in Brazil will provide an important contribution to PrEP rollout in Brazil. Conclusions The implementation of PrEP in Brazil is feasible. A synergistic rollout of treatment as prevention and PrEP will maximize public health and individual benefits of the country's comprehensive response to the AIDS epidemic., Introduction After the initial approval of the use of tenofovir disoproxil fumarate-emtricitabine (TDF/FTC) by the US Food and Drug Administration in 2012 for anti-HIV pre-exposure prophylaxis (PrEP), uptake was initially limited, but more recent community surveys and expert opinion suggest wider acceptance in some key populations. Discussion Demonstration projects are underway to determine the best practices in the United States to identify at-risk individuals in primary care and sexually transmitted disease clinics who could benefit from PrEP. Studies of PrEP in combination with behavioural interventions are being evaluated. Studies to evaluate the use of PrEP by HIV-uninfected women in HIV-discordant couples interested in safe conception are also getting underway. The optimal deployment of PrEP as part of a comprehensive national HIV/AIDS strategy in the United States has been limited by lack of knowledge among some at-risk people and by some medical providers indicating that they do not feel sufficiently knowledgeable and comfortable in prescribing PrEP. Studies are underway to determine how to assist busy clinicians to determine which of their patients could benefit from PrEP. Although most federal health insurance programmes will cover most of the costs associated with PrEP, underinsured patients in states that have not enacted health reform face additional challenges in paying for PrEP medication and appropriate clinical monitoring. Conclusions PrEP implementation in the United States is a work in progress, with increasing awareness and uptake among some individuals in key populations., Introduction HIV incidence remains high among young women in sub-Saharan Africa in spite of scale-up of HIV testing, behavioural interventions, antiretroviral treatment and medical male circumcision. There is a critical need to critique past approaches and learn about the most effective implementation of evidence-based HIV prevention strategies, particularly emerging interventions such as pre-exposure prophylaxis (PrEP). Discussion Women in sub-Saharan Africa are at increased risk of HIV during adolescence and into their 20s, in part due to contextual factors including gender norms and relationship dynamics, and limited access to reproductive and sexual health services. We reviewed behavioural, behavioural economic and biomedical approaches to HIV prevention for young African women, with a particular focus on the barriers, opportunities and implications for implementing PrEP in this group. Behavioural interventions have had limited impact in part due to not effectively addressing the context, broader sexual norms and expectations, and structural factors that increase risk and vulnerability. Of biomedical HIV prevention strategies that have been tested, daily oral PrEP has the greatest evidence for protection, although adherence was low in two placebo-controlled trials in young African women. Given high efficacy and effectiveness in other populations, demonstration projects of open-label PrEP in young African women are needed to determine the most effective delivery models and whether women at substantial risk are motivated and able to use oral PrEP with sufficient adherence to achieve HIV prevention benefits. Conclusions Social marketing, adherence support and behavioural economic interventions should be evaluated as part of PrEP demonstration projects among young African women in terms of their effectiveness in increasing demand and optimizing uptake and effective use of PrEP. Lessons learned through evaluations of implementation strategies for delivering oral PrEP, a first-generation biomedical HIV prevention product, will inform development of new and less user-dependent PrEP formulations and delivery of an expanding choice of prevention options in HIV prevention programmes for young African women., Introduction The extraordinary feat of proving the effectiveness of oral pre-exposure prophylaxis (PrEP) in clinical trials in different populations in a variety of settings may prove to have been easier than ensuring it is used well. Decision-makers must make difficult choices to realize the promise of antiretroviral prophylaxis for their countries. This paper outlines key economic, regulatory and distributive justice issues that must be addressed for effective and acceptable PrEP implementation. Discussion In considering the role that PrEP can play in combination prevention programmes, decision-makers must determine who can benefit most from PrEP, how PrEP can be provided safely and efficiently, and what kind of health system support will ensure successful implementation. To do this, they need contextualized information on disease burden by population, analyses of how PrEP services might best be delivered, and projections of the human resource and infrastructure requirements for each potential delivery model. There are cost considerations, varying cost-effectiveness results and regulatory challenges. The principles of ethics can inform thorny discussions about who should be prioritized for oral PrEP and how best to introduce it fairly. We describe the cost-effectiveness of PrEP in different populations at higher risk of HIV exposure, its price in low- and middle-income countries, and the current regulatory situation. We explore the principles of ethics that can inform resource allocation decision-making about PrEP anchored in distributive justice, at a time when universal access to antiretroviral treatment remains to be assured. We then highlight the role of advocacy in moving the PrEP agenda forward. Conclusions The time is ripe now for decisions about whether, how and for whom PrEP should be introduced into a country's HIV response. It has the potential to contribute significantly to high impact HIV prevention if it is tailored to those who can most benefit from it and if current regulatory and pricing barriers can be overcome. Advocacy at all levels can help inform decision-making and push the access agenda to avert HIV infections among those at highest risk of HIV exposure. The benefits will accrue beyond the individual level to slow HIV transmission at the population level.

La predicció de despeses, vendes o cobraments en l’àmbit de l’emprenedoria planteja la dificultat afegida de treballar amb dades extremadament incertes. Aquest fet ocasiona que la previsió de tresoreria o la previsió de pèrdues i guanys tingui associada un alt grau d’indeterminació. La lògica borrosa propicia la creació de nous models de prognosi que afavoreixen que l’emprenedor obtingui una visió de futur més àmplia. El nucli del treball doctoral està format per tres articles que presenten una proposta completa de solució a problemes actuals i reals de la predicció emprenedora centrats en potenciar la utilització de la lògica borrosa a nivell pràctic. Tanmateix, cada article desenvolupa un recurs informàtic d’implementació de cadascuna de les tècniques per tal de facilitar, en el cas que sigui possible, la seva incorporació a la praxi emprenedora., The prediction of costs, sales and payments in the field of entrepreneurship presents the added difficulty of working with extremely uncertain data. This means that the estimate of “cash flow forecasting” and the “income statement” contains a high degree of indetermination. The fuzzy logic promotes the creation of new prognostic models that allow the entrepreneur to gain a broader vision. The core of the doctoral thesis is formed by three papers in which everyone presents a full proposal for a solution to real and current problems of prediction focused on promoting the use of fuzzy logic in entrepreneurial practice. Additionally, each paper develops a computer resource implementation of each technique in order to facilitate, if possible, its joining of the entrepreneurial practice.

Orientador: Carla Taviane Lucke da Silva Ghidini Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica Resumo: Este trabalho trata do problema da produção de rações destinadas a bovinos de corte em confinamento em diferentes fases (cria, recria ou engorda), levando em consideração características nutricionais, eciências, custo-benefício e restrições de mercado para aquisição da matéria-prima, dado que a disponibilidade ou unidade de medida usada na venda dos ingredientes são limitadas, como por exemplo, os núcleos que são vendidos em sacos e os grãos e subprodutos agrícolas vendidos em toneladas. Tal limitação acaba elevando os custos de produção, pois a matéria-prima, provavelmente, será adquirida em excesso, ocasionando um aumento nos custos de transporte e armazenagem e até mesmo desperdício de matéria-prima. Uma vez que a motivação desse trabalho é auxiliar o criador de gado que produz a ração dada no período de confinamento dos animais, são propostos dois modelos matemáticos inteiro-misto, baseados no clássico problema da mistura, para determinar simultaneamente a melhor composição de diversas rações para bovinos de diferentes pesos e idades e um terceiro modelo matemático inteiro para determinar quais rações devem ser usadas para manter um confinamento com o menor custo possível e atendendo certos objetivos preestabelecidos, tais como, o número de dias que o animal cará confinado e o ganho de peso mínimo durante o confinamento Abstract: This paper handles the production problem of feeds destined to beef cattle, conned in dierent stages (raising, breeding or fattening), taking into consideration nutritional, eciency, benets, market restrictions of raw resources characteristics; given that availability or the metric used in the sale of the ingredients are limited, for example, the cores that are sold in sacks and the grain and its agricultural sub-products are sold in tons. This limitation ends up elevating the production costs, since its raw resource, probably, will be acquired in access, resulting in higher costs in transport, storage and even waste of raw resources. The motivation of the paper is to aid cattleman that produce feed data in the connement stage of the animals, two mixed-whole mathematical methods are proposed, based on classic mixture problem, to determine simultaneously the best composition of diverse bovine feeds for dierent weigh and age cattle, and a third whole mathematical problem to determine which feeds should be used to keep a connement cost as low as possible while attending these established objectives, days in connement and minimal weigh gain during connement Mestrado Matemática Aplicada e Computacional Mestre em Matemática Aplicada e Computacional CAPES

This paper proposes a new deep learning (DL) based model-free robust method for bulk system on-line load restoration with high penetration of wind power. Inspired by the iterative calculation of the two-stage robust load restoration model, the deep neural network (DNN) and deep convolutional neural network (CNN) are respectively designed to find the worst-case system condition of a load pickup decision and evaluate the corresponding security. In order to find the optimal result within a limited number of checks, a load pickup checklist generation (LPCG) algorithm is developed to ensure the optimality. Then, the fast robust load restoration strategy acquisition is achieved based on the de-signed one-line strategy generation (OSG) algorithm. The pro-posed method finds the optimal result in a model-free way, holds the robustness to handle uncertainties, and provides real-time computation. It can completely replace conventional robust optimization and supports on-line robust load restoration which better satisfies the changeable restoration process. The effectiveness of the proposed method is validated using the IEEE 30-bus system and the IEEE 118-bus system, showing high computational efficiency and considerable accuracy.

International audience; Versatile video coding (VVC) is the next generation video coding standard released in July 2020. VVC introduces new coding tools enhancing the coding efficiency compared to its predecessor high efficiency video coding (HEVC). These new tools have a significant impact on the VVC software decoder with a complexity estimated to two times HEVC decoder complexity. In particular, the adaptive loop filter (ALF) introduced in VVC as an in-loop filter increases both the decoding complexity and memory usage. These concerns need to be carefully addressed regarding the design of an efficient hardware implementation of a VVC decoder. In this paper, we present an efficient hardware implementation of the ALF tool for VVC decoder. The proposed solution establishes a novel scanning order between Luma and Chroma components that reduces significantly the ALF memory. The design takes advantage of all ALF features and establishes an unified hardware module for all ALF filters. The design uses 26 regular multipliers in a pipelined architecture with a fixed throughput of 2 pixels/cycle and fixed system latency regardless of the selected filter. This design operates at 600 MHz frequency enabling to decode on ASIC platform a 4K video at 30 frames per second in 4:2:2 chroma sub-sampling format.

The use of solar power in some applications is challenging due to sudden changes in irradiance level and the fast occurrence of Partial Shading Condition (PSC). For this reason, maximum power point tracking (MPPT) methods employed in photovoltaic (PV) applications allow for very fast detection and tracking of the maximum power point (MPP) during a partial shading condition. This fast reaction should minimize the power losses, have minimum steady-state oscillation and be accurate. In this paper, an analytical approach is proposed to track the real MPP in Uniform Irradiance Condition (UIC) and PSC via the use of analytical formulas of the PV system behavior. The proposed method exhibits a rapid tracking speed, stable steady-state performance, and low sampling rate in all conditions. The characteristics and performance of the proposed algorithm under UIC and PSC are investigated and demonstrated through simulations and experimental tests.

The last years have seen a growing body of literature on data-driven pedestrian inertial navigation. However, despite this, it is still unclear how to efficiently combine classical models and other a priori information with existing machine learning frameworks. In this paper, we first categorize existing approaches to data-driven pedestrian inertial navigation, including approaches where a machine learning algorithm is embedded into an overarching classical framework and purely data-driven frameworks. We then propose an estimation framework where navigation estimates obtained by classical means are fed to a machine learning algorithm which is trained to correct and improve the estimates. Further, we describe three symmetries that can be used to constrain the proposed estimation framework and thereby improve its performance. These are 1) the rotational symmetry of pedestrian dynamics, 2) the rotational symmetry of the sensors, and 3) the temporal symmetry of pedestrian dynamics. To demonstrate the usefulness of the proposed framework, we use data from foot-mounted inertial sensors utilizing zero-velocity updates under mixed walking and running. Machine learning corrections are implemented using both neural networks and Gaussian processes.

Context: Effort estimation is one of the essential phases that must be accurately predicted in the early stage of software project development. Currently, solving problems that affect the estimation accuracy of Use Case Points-based methods is still a challenge to be addressed. Objective: This paper proposes a parametric software effort estimation model based on Optimizing Correction Factors and Multiple Regression Models to minimize the estimation error and the influence of unsystematic noise, which has not been considered in previous studies. The proposed method takes advantage of the Least Squared Regression models and Multiple Linear Regression models on the Use Case Points-based elements. Method: We have conducted experimental research to evaluate the estimation accuracy of the proposed method and compare it with three previous related methods, i.e., 1) the baseline estimation method – Use Case Points, 2) Optimizing Correction Factors, and 3) Algorithmic Optimization Method. Experiments were performed on datasets (Dataset D1, Dataset D2, and Dataset D3). The estimation accuracy of the methods was analysed by applying various unbiased evaluation criteria and statistical tests. Results: The results proved that the proposed method outperformed the other methods in improving estimation accuracy. Statistically, the results proved to be significantly superior to the three compared methods based on all tested datasets. Conclusion: Based on our obtained results, the proposed method has a high estimation capability and is considered a helpful method for project managers during the estimation phase. The correction factors are considered in the estimation process. Author, Faculty of Applied Informatics, Tomas Bata University in Zlin [IGA/CebiaTech/2021/001, RO30216002025]

This paper provides a subspace method for closed-loop identification, which clearly specifies the model order from noisy measurement data. The method can handle long I/O data of the target system to be noise-tolerant and determine the model order via nuclear norm minimization. First, the proposed method compresses the long data by projecting them to an appropriate low dimensional subspace, then obtains a low order model whose order is specified by a combination of data compression and nuclear norm minimization. Its effectiveness is demonstrated through detailed numerical examples.

Model-based systems engineering (MBSE) is considered an important approach for understanding multidomain fields and is widely used in complex systems such as aerospace. In this article, a detailed survey of MBSE literature was conducted from its commencement to the present trends through bibliometric analysis. Some bibliometric tools were used to implement a visual network analysis of MBSE-related manuscripts. The results of the bibliometric study revealed the interrelationship and distribution of researchers in multidomain fields. The authorized sources of MBSE papers were also assorted. The current practices of MBSE were analyzed. The future directions for MBSE based on the current practices were discussed. We found that MBSE's research has been conducted by many research teams with distinctive characteristics, and the top publishing sources in this field have emerged. Research on MBSE focuses on system engineering, languages, system of systems, and digitalization. The development of new technologies such as next-generation modeling languages is improving current practical problems. The findings of this study may help researchers gain a faster and more comprehensive understanding of the current and future developments in MBSE.

Dispatching active distribution networks (ADNs) is an energy-intensive application that, if implemented via battery-energy storage systems (BESSs), can require a large capacity of these assets in order to fully balance the uncertainties caused by the stochastic demand and generation. The insufficient capacity of the BESSs often leads to their state-of-charge (SOC) saturation; this results in unreliable dispatch tracking. In this work, we propose and experimentally validate a real-time control scheme that achieves a highly-reliable dispatching of ADNs and ensures that the BESSs’ SOC is not saturated during the daily operation. Our proposed scheme uses a two-layer model predictive control (MPC). The upper-layer MPC, running every 5 minutes, optimizes the BESSs’ SOC trajectories while minimizing the tracking error, considering the prosumption forecast of the whole day. Then, the lower layer MPC, running every 30 seconds, takes the BESSs’ SOC trajectories as constraints while achieving a high-resolution tracking of the dispatch plan over the current 5-minute time horizon. Both layers account for the grid constraints by using the augmented relaxed optimal power-flow (AR-OPF) model; an exact convex relaxation of the original AC-OPF and used in this paper (for the first time in the literature) to solve a real-time constrained control problem for ADNs. Our proposed framework was experimentally validated using a 1.5 MVA/2.5 MWh BESS connected to an actual 24-node medium-voltage (MV) ADN that, in Aigle, Switzerland, hosted an uncontrollable 3.2 MWp distributed photovoltaic generation, 3.4 MVA hydro-power generations, and a 2.8 MW base demand.

Background: HIV is a virus that is directed at destroying the human immune system thereby exposing the human body to the risk of been affected by other common illnesses and if it is not treated, it generates a more chronic illness called AIDS. Materials and Methods: In this paper, we employed the fixed-point theory in developing the uniqueness and existence of a solution of fractional order HIV/AIDS model having Caputo-Fabrizio operator. This approach adopted in this work is not conventional when solving biological models by fractional derivatives. Results: The results showed that the model has two equilibrium points namely, disease-free, and endemic equilibrium points, respectively. We showed conditions necessitating the existence of the endemic equilibrium point and showed that the disease-free equilibrium point is locally asymptotically stable. We also tested the stability of our solution using the iterative Laplace transform method on our model which was also shown stable agreeing with the disease-free equilibrium. Conclusions: Numerical simulations of our model showed clear comparison with our analytical results. The numerical solutions show that given fractional operator like the Caputo-Fabrizio operator, it is less noisy and hence plays a major role in making a precise decision and gives room or opportunity (‘freedom’) to use data of specific patients as the model can be easily adjusted to accommodate this, as it a better fit for the patients’ data and provide meaningful predictions. Finally, the result showed the advantage of using fractional order derivative in the analysis of the dynamics of HIV/AIDS over the classical case.

Mathematics constitutes a key component in engineering education. Engineering students are traditionally offered a number of mathematics courses which provide the knowledge needed at the workplace. Unfortunately, many students perceive mathematics as a discipline that teaches mostly procedures not relevant to their future careers and often view it as one of the main obstacles on their way to an engineering degree. In this paper, we discuss how introducing university students in a standard Differential Equations course to mathematical modelling (MM), a powerful strategy for solving real-life problems, contributes to the development of their mathematical competencies, motivates their interest to mathematics, promotes the use of advanced mathematical thinking, methods of applied mathematics, and digital computational tools.