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Mental health and mental illness have been contested concepts for decades, with a wide variety of models being proposed. To date, there has been no exhaustive review that provides an overview of existing models. To conduct a quasi-systematic review of theoretical models of mental health problems. We searched academic databases, reference lists, and an electronic bookshop for literature that proposed, endorsed, reviewed, or critiqued such models. Papers, book chapters, and books were included with material by researchers, clinicians, non-medical professions, and service users writing between 2000 to June 2020 being considered. The study was registered with the Open Science Framework (No. osf.io/r3tjx). Based on 110 publications, we identified 34 different models which were grouped into five broader categories. Many models bridged two or more categories. Biological and psychological approaches had the largest number of models while social, consumer and cultural models were less diversified. Due to the non-empirical nature of the publications, several limitations in terms of search and quality appraisal apply. We conclude that mental health care needs to acknowledge the diversity of theoretical models on mental health problems. [ABSTRACT FROM AUTHOR]

This paper contributes to accumulating the knowledge base about prospective elementary school teachers' (PTs') understanding of socio-critical modeling by exploring how PTs make connections to features of mathematical modeling and social justice while posing mathematical problems and reflecting on their problem-posing. We present a conceptual framework for posing problems that connect social justice issues with the features of mathematical modeling. Drawing on the analysis of 36 individual modeling problems generated by the PTs and 36 written reflections PTs completed throughout their problem-posing activity, we illustrate various ways in which PTs connect the multi-faceted features of mathematical modeling (i.e., realistic context, model development, and shareable process) and social justice (i.e., micro – and macro – level). The PT-posed problems were categorized as (a) modeling problems presenting micro – and macro-level social justice issues (27%), (b) modeling problems presenting micro-level social justice issues (22%), (c) contextualized mathematical problems presenting micro – and macro-level social justice issues (25%), and (d) contextualized mathematical problems presenting micro-level social justice issues (17%). Our work describing the complexity of posing social justice-oriented mathematical modeling (SJMM) problems and articulating decisions PTs make while posing SJMM problems set directions for future efforts and research in teacher preparation. [ABSTRACT FROM AUTHOR]

This paper outlines a framework for strength training as a dynamical model of perceptual-motor learning. We show, with emphasis on fixed-point attractor dynamics, that strength training can be mapped to the general dynamical principles of motor learning that arise from the constraints on action, including the distribution of practice/training. The time scales of the respective dynamics of performance change (increment and decrement) in discrete strength training and motor learning tasks reveal superposition of exponential functions in fixed-point dynamics, but distinctive attractor and parameter dynamics in oscillatory limit cycle and more continuous tasks, together with unique timescales to process influences (including practice, learning, strength, fitness, fatigue, warm-up decrement). Increments and decrements of strength can be viewed within a dynamical model of change in motor performance that reflects the integration of practice and training processes at multiple levels of learning and skill development. [ABSTRACT FROM AUTHOR]

This paper presents a magnetic coupling piezoelectric energy harvester based on galloping and vortex-induced vibration to scavenge low-speed wind. The influence of magnet spacing on the piezoelectric energy harvester is analyzed by using a mathematical model. The power generation performance of the energy harvester is explored by changing the magnet spacing. The experimental results show that the distance is negative related to the onset wind speed. Vortex induced vibration still make the system have voltage output. The output power can be effectively improved by increasing the magnet spacing while the magnetic force beyond a certain range can be ignored. [ABSTRACT FROM AUTHOR]

Mental models are knowledge structures employed by humans to describe, explain, and predict the world around them. Shared Mental Models (SMMs) occur in teams whose members have similar mental models of their task and of the team itself. Research on human teaming has linked SMM quality to improved team performance. Applied understanding of SMMs should lead to improvements in human-AI teaming. Yet, it remains unclear how the SMM construct may differ in teams of human and AI agents, how and under what conditions such SMMs form, and how they should be quantified. This paper presents a review of SMMs and the associated literature, including their definition, measurement, and relation to other concepts. A synthesized conceptual model is proposed for the application of SMM literature to the human-AI setting. Several areas of AI research are identified and reviewed that are highly relevant to SMMs in human-AI teaming but which have not been discussed via a common vernacular. A summary of design considerations to support future experiments regarding Human-AI SMMs is presented. We find that while current research has made significant progress, a lack of consistency in terms and of effective means for measuring Human-AI SMMs currently impedes realization of the concept. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic revealed that many countries have failed to provide the general population with the cognitive tools to thoroughly understand and cope with a global health crisis. While scientists and leaders worldwide have struggled to discover ways to contain the spread of the virus, this difficult task has become overwhelming due to the limited ability of many citizens to grasp the urgency of the situation. Although in today's digitized world we have endless access to data and more ways to represent information and statistics than ever before, numerous incidents have demonstrated that the frequent misapprehension of data can cause confusion rather than clarity. This opinion paper examines how issues such as the misunderstanding of large quantities, fractions, probabilities, and mathematical modeling may be affecting the way people view the current pandemic. Finally, we also discuss how numeracy can act as a protective factor against motivated reasoning, which often affects how we consume information related to the pandemic. [ABSTRACT FROM AUTHOR]

In this paper, we propose a model for idealized diatonic and chromatic voice leadings between seventh chords and study its computational aspects. The model provides a mathematical formalization of the concept of tonal seventh chord realizations including augmented sixth chords. Certain contrapuntal aspects, such as preparation and resolution of certain dissonant intervals, are taken into account. Possible applications of the model are discussed using a graph-theoretic approach. In particular, we present an algorithm for generating concrete voicings from sequences of seventh-chord symbols. [ABSTRACT FROM AUTHOR]

This paper deals with a mathematical model for tumor growth with angiogenesis and a necrotic core. The problem is a nonlinear problem which has two free boundaries: the external boundary of the tumor and the external boundary of the internal necrotic core. Using the implicit function theorem, the relationship between the two free boundaries is studied. The asymptotic stability of the unique steady-state solution is proved. The effect of nutrient concentration on tumor growth is studied. The relationship between the stage with a necrotic core and the stage without necrotic core is also studied. The results show that whether the steady-state of tumor growth has a necrotic core or not is determined by the concentration of external nutrients. The stage of tumor with necrotic core and the stage without necrotic core could transform into each other by adjusting the concentration of external nutrients. [ABSTRACT FROM AUTHOR]

As the population ages, older workers represent an increasingly large segment of the labor force which has led to numerous studies investigating productive aging. This exploratory essay focuses on the remunerated work dimension of productive aging. The main purpose is to discuss the application of a human ecology approach to understand the contexts that influence older adults to retire or continue working. This paper is supported by a literature review related to the ecological model proposed by Bronfenbrenner. This model contributes to the understanding of several environments known as microsystem, mesosystem, exosystem, macrosystem, and chronosystem. Each of those environments seems to influence whether older adults continue to work or decide to retire. [ABSTRACT FROM AUTHOR]

In-depth isolation of flooded-out reservoir zones is widely used in water injection and water production control in oilfields. This paper looks at the research results of a new technological solution – a method and mechanism of deep-penetrating insulation of highly permeable reservoir areas. Approximate mathematical models are used to describe oil-saturated reservoirs flooding with chemical compositions used as a displaced fluid. The mathematical model of the problem is reduced to a partial differential equation with initial boundary conditions. The article also presents the results of the numerical implementation of the transfer equations of concentrations of gel-forming components and a thickener. In a non-uniform grid domain, the problem at hand is replaced by a discrete problem using a combination of an explicit and implicit-difference scheme that increases the order of accuracy and is solved by the run-through method. Effective algorithms for solving the one-dimensional problem are obtained, taking into account the equations of adsorption and convective diffusion. The developed method increases the efficiency of the in-deep isolation treatment of flushed zones and can be applied to related reservoir flooding projects. [ABSTRACT FROM AUTHOR]

Stimulated reservoir volume (SRV) is a key parameter affecting the post-fracturing production of ultra-low permeability reservoirs. Accurate prediction of the SRV shape and size is of vital significance for pre-fracturing stimulation design and post-fracturing effect evaluation. In this paper, an equivalent mathematical model for simulating two-dimensional SRV growth is proposed by integrating the fracture width equation, tensor permeability conversion, cubic law and calculation method of fracture porosity with mass conservation equation of injected fluid in natural fracture system. The finite difference method is used to derive the numerical discrete equation, and the fluid pressure and average fracture width in each grid block are obtained by solving the coupled fluid conservation equation and fracture width equation. The model is validated by comparing the results obtained from this work with others from literature. A parametric sensitivity study was performed to analyze the effects of some factors incorporating approaching angle, natural fracture spacing, horizontal principal stress difference, pumping rate and fracturing fluid viscosity on the SRV (including size, aspect ratio, and arithmetic mean fracture width in SRV region). The results show that SRV increases with the decrease of approaching angle, principal stress difference, injection rate, viscosity of fracturing fluid and fracture density. The width of branch fracture decreases with the increasing approaching angle and principal stress difference but increases with the increasing pumping rate and fluid viscosity. [ABSTRACT FROM AUTHOR]

This paper intends a Euler-Lagrange passivity-based controller (EL-PBC) for the three-level (TL) Ćuk PFC converter for EVs battery charging application. The TL Ćuk converter has features of reduced filter size and voltage stress of switches. First, the Euler-Lagrange formulation is used to develop the mathematical modelling. Then, the EL-PBC methodology is implemented by injecting a virtual resistor in series with the input inductor. Further, the stability analysis is also carried out. To improve the performances against input perturbations and reduce the steady state error, a PI controller is integrated with the aforesaid controller and its performances are investigated. Furthermore, the power quality of the charger is assessed and it satisfies IEC 61000-3-2 Class C standard. This controller is also compared with the benchmark PI controller. A prototype model of same specifications is tested in hardware in loop. Computer simulations and test results are presented to validate the theoretical aspects. [ABSTRACT FROM AUTHOR]

This paper presents a model for evaluating alternative Flexible Manufacturing Systems by considering both quantitative and qualitative factors. The evaluation process utilizes a recently proposed Data Envelopment Analysis (DEA) model, which incorporates both ordinal and cardinal measures, in conjunction with new extensions in DEA. The paper contributes to the body of knowledge in two important ways. First, it provides a new model based on pair-wise comparisons of specific alternatives, which significantly improves the discriminatory power of DEA. The second major contribution is to detail the model's utility in its application for evaluating strategic manufacturing technologies, specifically Flexible Manufacturing Systems. The consideration of both tangible and intangible factors, which is a primary goal in strategic evaluation of systems, is achieved in this methodology. The model is illustrated through an application on a previously reported data set. The analysis of results provide useful insights that include both seller's and buyer's perspectives of system evaluation. [ABSTRACT FROM AUTHOR]

This paper introduces an approach to achieving business integration within a manufacturing system based on executing models of system behaviour that describe important aspects of coordination within the system. The strategy for demonstrating the approach is to combine formalisms derived principally from CIMOSA and Petri nets into an engineering workbench where models (of 'what' the integrated manufacturing system is expected to achieve and 'how' the system can achieve it) are executed. An important aspect of the work is to enable modelling and simulation to be consistently performed using the same set of models that are used to construct the run time system. As part of this overall support, this paper details the results obtained from the realization, application and evaluation of the engineering workbench, particularly in regard to its support for modelling and simulation. [ABSTRACT FROM AUTHOR]

A new multi-objective heuristic algorithm for resolving the facility layout problem is presented in this paper. It incorporates qualitative and quantitative objectives and resolves the problem of inconsistent scales and different measurement units. We consider suboptimal solutions since optimal methods are computationally unfeasible to large layout problems. In this paper, we develop the dominant index (DI) and incorporate it in our heuristic algorithm to guarantee the quality of proposed solutions. Moreover, a new measure of solution quality, dominant probability ( D p), is offered to determine the probability that one layout is better than the others. Computational results show that our proposed heuristic algorithm is an efficient method for obtaining good-quality solutions. [ABSTRACT FROM AUTHOR]

Fractional order partial differential equations are very important mathematical models in describing lots of anomalous dynamic behaviors in multiple disciplines. This paper focuses upon the fractional order hyperbolic equation, which is influenced by different types of time-dependent oscillating coefficients on the principal operator part. We apply the essential techniques from harmonic analysis and probability analysis to explore the upper bound of loss of regularity. Furthermore, in order to demonstrate the optimality of the estimates, an appropriate counter-example with periodic coefficients is constructed to show the lower bound of loss of regularity by the application of instability arguments. [ABSTRACT FROM AUTHOR]

In this paper, we present a mathematical analysis to a Cahn-Hilliard/Allen-Cahn system with degenerate mobility that models an isothermal process of solidification of a binary alloy. This model is able to predict an observable phenomenon called solute trapping. The existence of global weak solutions for the system is proved. We approximate the degenerate system and show the convergence of solutions to the approximated non-degenerate problem to a solution of the degenerate one. We also investigated deeply the non-degenerate system by showing the existence of global weak solutions, the existence of global strong solutions in the two-dimensional case, and local strong solutions in the three-dimensional case, as well as, providing conditions to the uniqueness be satisfied. [ABSTRACT FROM AUTHOR]

Through an interdisciplinary literature review, this propositional paper explores the emergence and unfolding of professionals' moral identity conflicts involving important but contrasting values. Building on the exemplary case of physicians' professional-religious dilemmas in End-of-Life circumstances, we develop a multilevel model of professional-personal identity conflict dynamics in ethically-charged situations in which we integrate individual-level mechanisms with organizational-level boundary conditions, namely peer social support and ethical climate, in relation to psychological well-being. Our conceptual model contributes to the ethics, identity and human behavior literature by advancing suggestions of how professionals may prevent or/and resolve moral conflicts concerning also other identities and contexts. [ABSTRACT FROM AUTHOR]

Providing students with the necessary skills to apply mathematical knowledge in real-life situations through mathematical modelling is a common goal of contemporary mathematics curricula. As such, it is important that prospective mathematics teachers develop the ability to design learning environments that serve this purpose in their future teaching. This paper presents an activity presented as part of a course that, among other outcomes, aimed to establish awareness in mathematics teacher candidates of the potential use of computers in mathematical modelling. The activity included an experimental investigation of Buffon's needle problem. The steps used to solve the problem using a GeoGebra environment are described in this article. [ABSTRACT FROM AUTHOR]

Building fair, equitable, and beneficial partnerships between institutions collaborating in research in low- and middle-income countries (LMIC) and high-income countries (HIC) has become an integral part of research capacity building in global health in recent years. In this paper, we offer an example of an academic collaboration between the University of California Los Angeles, Center for Health Policy and Research (UCLA CHPR) and the University of Philippines, Manila, College of Public Health (UPM CPH) that sought to build an equitable partnership between research institutions. The partnership was built on a project to build capacity for research and produce data for policy action for the prevention and care of non-communicable diseases (NCDs) through primary healthcare in the Philippines. The specific objectives of the project were to: (1) locally adapt the Primary Care Assessment Tool for the Philippines and use the adapted tool to measure facility-level primary care delivery, (2) conduct focus group discussions (FGDs) to gather qualitative observations regarding primary care readiness and capacity, and (3) conduct a comprehensive population-based health survey among adults on NCDs and prior healthcare experience. We describe here the progression of the partnership between these institutions to carry out the project and the elements that helped build a stronger connection between the institutions, such as mutual goal setting, cultural bridging, collaborative teams, and capacity building. This example, which can be used as a model depicting new directionality and opportunities for LMIC-HIC academic partnerships, was written based on the review of shared project documents, including study protocols, and written and oral communications with the project team members, including the primary investigators. The innovation of this partnership includes: LMIC-initiated project need identification, LMIC-based funding allocation, a capacity-building role of the HIC institution, and the expansion of scope through jointly offered courses on global health. [ABSTRACT FROM AUTHOR]

At present, most of the energy analysis of the engineering system is only from the energy point of view. In this paper, the theory of exergoeconomics is combined with the operation optimization of the gathering and transportation system. In terms of exergy flow distribution and the construction of each equipment, the exergy value of total 17 exergy flows and the non-energy cost of 6 main equipment in the process are calculated. An exergoeconomic model in technological process of gathering and transportation system is established. Combined with the exergoeconomic cost valuation strategy, 11 auxiliary equations are used to get the economic cost of each flow unit in the process. Taking the minimum operation exergy cost as the objective function, a mathematical model of operation optimization in exergoeconomics is established, and each decision variable is constrained on the basis of the actual site conditions. The objective function within the range of process requirements is solved by iterative method. The optimal water mixing temperature is 47.1°C, and the optimal water mixing volume is 840.7 m3/d under the actual working condition of the site in light of the calculation results. [ABSTRACT FROM AUTHOR]

Many people living with substance use disorder require multiple types of support to reduce use and mitigate harms. Recovery community centers have emerged alongside formal substance use treatment and mutual self-help groups as another option to support peoples' recovery. Research on the helpfulness of recovery community centers is limited. The purpose of this paper was to describe what Staff and Member Facilitators perceived as helpful components of a recovery community center. Semi-structured interviews were conducted with 10 Staff and six Member Facilitators of a recovery community center, Recovery Café, in Seattle, Washington. Qualitative interviews were analyzed via grounded theory approach. Eleven themes emerged on the helpful components of Recovery Café, including tangible/infrastructure and intangible/experiential strengths. Three themes related to opportunities for program improvement. Many themes on the helpful components were consistent with prior research on recovery community centers and other supports for recovery. Findings provide insight into potential active ingredients and mechanisms of recovery community centers and highlight the potential role of recovery capital. Additional research is needed to test these components to improve the understanding of if and how recovery community centers work to support people with substance use disorders in recovery. [ABSTRACT FROM AUTHOR]

The evolution of dispersal is a classical question in evolutionary biology, and it has been studied in a wide range of mathematical models. A selection-mutation model, in which the population is structured by space and a phenotypic trait, with the trait acting directly on the dispersal (diffusion) rate, was formulated by Perthame and Souganidis [Math. Model. Nat. Phenom. 11:154–166, 2016] to study the evolution of random dispersal toward the evolutionarily stable strategy. For the rare mutation limit, it was shown that the equilibrium population concentrates on a single trait associated to the smallest dispersal rate. In this paper, we consider the corresponding evolution equation and characterize the asymptotic behaviors of the time-dependent solutions in the rare mutation limit, under mild convexity assumptions on the underlying Hamiltonian function. [ABSTRACT FROM AUTHOR]

This historical discussion paper is an overview for nurses working in mental health of medieval and Early Modern texts known as Ars Moriendi literature, which focuses on the art of dying, grief and loss. Primary and secondary historical documents are used to describe Ars Moriendi literature and how historical understandings of death and dying were shaped within a spiritual context. Ars Moriendi concepts are compared with modern Western secularised and medicalised notions to prompt reflection on historical versus modern approaches to dying, grief and loss. [ABSTRACT FROM AUTHOR]

While disability is recognised by the United Nations Convention on the Rights of Persons with Disabilities (CRPD) as an evolving concept, the language of positive behaviour support has not kept pace with the current human rights-based approach. The widely-used terms 'challenging behaviour' and 'behaviours that challenge' imply that the behaviour is inherent in a person with disability. Words have power in shaping practice: when the behaviour of the person with disability is framed as the problem, this leads to a pathologisation or labelling that can provide a rationale to medicate and restrain as a way of 'managing the challenging behaviour'. Many behaviours seen as being challenging could be better understood as 'adaptive behaviours to maladaptive environments', or legitimate responses to difficult environments and situations. In this paper, we argue that the language and implementation of positive behaviour support should better take into account the CRPD and contemporary evidence on behaviour change interventions, which support a shift away from focusing on individuals' behaviours towards putting environments front and centre. We outline how the social-ecological model could be used as a framework to more explicitly address 'environments of concern' in developing tailored and system-wide responses to behaviour support needs. We argue there is an urgency for this paradigm shift to better reflect the views of people with disability and improve outcomes. [ABSTRACT FROM AUTHOR]

Simple moving average (SMA) is a well-known forecasting method. It is easy to understand and interpret and easy to use, but it does not have an appropriate length selection mechanism and does not have an underlying statistical model. In this paper, we show two statistical models underlying SMA and demonstrate that the automatic selection of the optimal length of the model can easily be done using this finding. We then evaluate the proposed model on a real data-set and compare its performance with other popular simple forecasting methods. We find that SMA performs better both in terms of point forecasts and prediction intervals in cases of normal and cumulative values. [ABSTRACT FROM AUTHOR]

In this paper, we seek robust policies for a multi-stage production/inventory problem to minimise total costs, including switching, production, inventory or shortage costs. While minimising switching costs often leads to non-convexity in the model, 0-1 variables are introduced to linearise the objective function. Considering the impossibility of obtaining the exact distribution of uncertain demand, we study the production/inventory problem under worst cases to resist uncertainty. In contrast to traditional inventory problems, unexpected yields in production are considered. Robust support vector regression is developed to approximate the yields of each unit.Amixed-integer linear programming is proposed, employing the duality theory to address the min--max model. A practical case study from cold rolling is considered. Experiments on the actual steel production data are reported to illustrate the validity of the proposed approach. [ABSTRACT FROM AUTHOR]

Resource-efficient technologies for cutting sheet materials allow for the contours of cut-off details to be overlapped. This includes the Intermittent Cutting Problem and the Endpoint Cutting Problem. This paper reviews mathematical models of such resource-efficient cutting processes and suggests algorithms for defining the cutter route under technological constraints. As soon as a cutting plan is given, optimisation with shortening the total length of idle passes. No information of the detail shape is required to define the sequence of detail cutting. This is why all curves without self-intersections and contiguities that are a constituent part of detail boundaries may be interpreted as edges of the plane graph G, and all points of intersection and contiguity may be interpreted as vertices of the graph G. Up to homeomorphism, plane graph G can be represented by a list of edges with incident vertices and faces . This allows the restrictions of the planed cutter trajectory to be formalised in terms of graph theory. A series of algorithms for constructing the permitted route in the plane graph G as an image of the cutting plan is suggested. The constructed route for the graph G can be interpreted as a tool trajectory for the cutting plan which is the inverse image of graph G. [ABSTRACT FROM AUTHOR]

The psychological wellbeing of Queer and Gender Diverse Young People (QGDYP) has received attention of late, and increasing research evidences much higher rates of psychological distress experienced by these groups, compared to their straight, cisgender counterparts. Far more limited is research exploring queer and gender diverse young people's own perspectives on their psychological wellbeing, an absence we address with the current study. We interviewed 21 queer or gender diverse 16–18-year-olds in Aotearoa New Zealand about their understandings of mental health and wellbeing. We took a critical realist thematic approach to analysis. This paper focuses on how participants made sense of their own distress. We explore and unpack three intersecting key themes around: 1) cisheterosexism, but not personally affected; 2) dismissal of QGDYP; and 3) validation and comfort in the biomedical model. We discuss the tensions of articulating these positions and (also) challenging cisheterosexism, and the implications for recognising and reducing the distress experienced by queer and gender diverse youth. We aim to inform policy and practice to support and ultimately improve psychological wellbeing for queer and gender diverse young people. [ABSTRACT FROM AUTHOR]

In 1933, Ragnar Frisch introduced a distinction between microdynamics and macrodynamics. His claim that he proposed the first macrodynamic analysis and that microdynamic schemes were limited to single markets or individual behaviours influenced the subsequent development of economic models. But the division was above all between tools: maximisation at the individual level, and dynamic analysis at the aggregate level. What was at stake was the question of economic rationality and whether it could be extended to an aggregate system. This paper reconstructs the different research programs to give a new picture of the development of early mathematical models in economics. [ABSTRACT FROM AUTHOR]

The tubeless vortex reducer was used to reduce the pressure drop in a cavity with radial inflow. In previous studies, the mechanism of vortex breakdown in tubeless vortex reducers was not clear, and there was a lack of direct guidance for engineering design. In this paper, we studied the vortex and pressure in the cavity in detail by large-eddy simulation (LES) and experiments. A mathematical model, which has high applicability and compatibility, was established to guide the pre-design of tubeless vortex reducers. The LES results showed that the high-speed and large-scale vortices broke rapidly at the nozzle inlet and reached the minimum size at the nozzle outlet. Furthermore, the enhancement of vortex in the downstream cavity was restrained. When the rotating speed was relatively low, strong negative vortices formed and the pressure drop increased in the downstream cavity. The experiments showed that the nozzle performance directly affected the flow characteristics and pressure drop in the cavity. Compared with the simple cavity, the tubeless vortex reducer generated lower pressure drop. The average relative error between the mathematical model and the experimental results was only 9.3%. [ABSTRACT FROM AUTHOR]

Augmented Reality (AR) technology has been increasingly utilised in mobile shopping apps to enhance consumers' mobile shopping experiences, thereby affecting consumers' impulse buying behaviour. Drawing upon the Spatial Presence Theory and the Elaboration Likelihood Model, the current study aims to empirically investigate AR-related factors (vividness, spatial accuracy, local presence) and their impacts on impulse buying behaviour related factors (arousal, perceived diagnosticity, and urge to buy impulsively) in the context of AR mobile shopping apps. In this study, an experiment employing a full 2X2 factorial between-subject experimental design was carried out. There were a total of 137 participants actively involved in this experiment. The data analysis results and findings, along with the implications of this study, are provided in the paper. [ABSTRACT FROM AUTHOR]

The paper's main aim is to investigate the 2019 coronavirus disease in Ethiopia using a fractional-order mathematical model. It would also focus on the importance of fractional-order derivatives that may help us in modelling the system and understanding the effect of model parameters and fractional derivative orders on the approximate solutions of our model. A SELAIQHCR model is constructed using nonlinear differential equations in the Atangana–Baleanu non-integer operator in the Caputo sense. After that, the Chebyshev fourth kind spectral collocation method is used to change a fractional system to an algebraic system. Newton iterative technique is used to solve the converted system. The next-generation matrix technique is used to obtain the effective reproduction number. The COVID-19-free equilibrium point and endemic equilibrium point, solution positivity and boundedness, and their stability are all carefully done. The sensitivity of the effective reproduction value with respect to the key model parameters is discussed. The beginning values provided for our system were obtained using reports from the Ethiopian Public Health Institute from 29 February 2021 to 7 June 2021. The fundamental reproduction number is obtained with R 0 = 1.4331. The model's numerical solutions are represented graphically. [ABSTRACT FROM AUTHOR]

The goal of this paper is to investigate the influence of the waning immunity on the dynamics of Tilapia Lake Virus (TiLV) transmission in wild and farmed tilapia within freshwater. We formulate a model for which susceptible individuals can contract the disease in two ways: (i) direct mode caused by contact with infected individuals; (ii) indirect mode due to the presence of pathogenic agents in the water. We obtain an age-structured model which combines both age since infection and age since recovery. We derive an explicit formula for the reproductive number R 0 and show that the disease-free equilibrium is locally asymptotically stable when, R 0 < 1. We discuss on the form of the waning immunity parameter and show numerically that a Hopf bifurcation may occur for suitable immunity parameter values, which means that there is a periodic solution around the endemic equilibrium when, R 0 > 1. [ABSTRACT FROM AUTHOR]

Aiming at the problem of autonomous collision avoidance of unmanned vessels in the case of multiple vessels encountering at sea, this paper proposes a method for collision avoidance of vessels in open water based on the Mathematical Model Group (MMG) vessel motion mathematical model. This method uses Model Predictive Control (MPC) model algorithm, and considers vessel maneuverability and the International Regulations for Preventing Collision at Sea, 1972 (COLREGs), and uses fuzzy mathematics to analyze the collision risk of vessels during navigation, and then constructs the evaluation function of the collision avoidance algorithm. The vessel's autonomous collision avoidance is realized. The simulation results show that the algorithm can solve the problem of autonomous vessel collision avoidance in the case of multi-vessel encounters in open water, which verifies the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

Digital music albums can be sold either as singles or as a full album, which is not an option for selling physical music products. This paper investigates three pricing strategies for selling digital music albums. The first (strategy S) sets a unified unit price and all songs are sold at this price. The second (strategy F) determines a bundling price for selling the whole album. The third (strategy M) mixes strategies S and F. It offers two prices: one is for a unit song and the other for the whole album. We develop mathematical models for this problem and design enumeration-based iteration algorithms to solve these models for optimality. Through a database consisting of 243 groups of numerical results, we establish a decision tree model, a popular data mining technique, to explain which strategy should be employed under various conditions. [ABSTRACT FROM AUTHOR]

This paper revisits the reliability-redundancy allocation problem as an important component of complex system design. In order to develop more reliable structures, the recently introduced K-mixed redundancy strategy is implemented to explore its power in solving different test problems. The strategy in question comprises as its decision variables, component reliability, redundancy level, and optimal redundancy strategy each of which must be optimally determined for each subsystem to ensure best performance of the whole system. To achieve this objective, a mathematical model is developed for formulating test problems under the K-mixed strategy and a proper genetic algorithm is employed to solve them. Results reveal that the new strategy outperforms not only the conventional active and standby strategies but even its mixed strategy counterpart as well while it also yields to more reliable structures. Moreover, the K-mixed strategy is shown as the superior one for systems with switching mechanisms of low reliability. [ABSTRACT FROM AUTHOR]

Over the last few years, the concept of robust optimization (RO) and its application to power system problems have been at the center of much recent research due to its successful implementation in handling uncertainties. In this regard, this paper presents a new approach for hybrid stochastic/robust transmission expansion planning (TEP), considering three sources of uncertainties, including demand growth, generation capacity, and thermal capacity of transmission lines. These uncertain parameters are modeled using an ellipsoidal uncertainty set, which can capture the correlation efficiently. The TEP problem is modeled as a bilevel mathematical optimization where the lower level is replaced by its Lagrange dual optimization problem using the duality theorem (DT). One main benefit of using the dual problem is that all uncertainties will appear in the objective function and thus can be converted to convex second-order cone constraints. The entire bilevel problem is then solved using the standard column-and-constraint generation (C&CG) technique by decomposing the mathematical problem into a master and a binary variable-free subproblem. Numerical studies on two test power systems validate the effectiveness of the proposed model. The results indicate that the presented methodology is more efficient than the existing models from the computational complexity perspective. [ABSTRACT FROM AUTHOR]

Governments are obligated to safeguard social inclusion for disabled people through user-led personal assistance (PA) under Article 19 of the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD). This scoping review was carried out to map and explore current knowledge on how governments internationally have managed PA schemes in response to the UNCRPD. The review examined 99 documents, and categorised the literature into the following themes; legislation, funding, model of service provision, governance and regulation, and the COVID-19 pandemic response. We include recommendations to co-design legislation and quality improvement policies to ensure that PA schemes are underpinned by a social model of disability mindset. Further research needs to be undertaken to guarantee that policymakers include the voice of PA users in the management of PA schemes. This article looked at 99 documents to find out how governments are managing personal assistance (PA). It found out that governments can often decide to spend less money on a PA scheme rather than protect our rights. To overcome this problem the documents recommended that legislation for PA schemes must be designed with disabled people. Governments must redirect their money from institutional services to community-based services. Eligibility criteria to control access and the costs of PA should be removed. This paper suggests that we need to have the voice of the PA user to direct the design and delivery of PA schemes. Supplemental data for this article is available online at [ABSTRACT FROM AUTHOR]

The Zipf-Mandelbrot distribution serves as a mathematical model for ranked frequencies in many areas of scientific research, including linguistics. Many linguistic units, like e.g., words or word n-grams, follow this distribution. However, in some cases, such as for graphemes in linguistics or species abundance and diversity data in biology, the parameters of the Zipf-Mandelbrot distribution are virtually uninterpretable, as their values strongly depend on the precision of numerical methods used to estimate them (values from several tens to several hundreds are not uncommon). It is shown in the paper that these values can be explained by the convergence to the geometric distribution, which forces both parameters of the Zipf-Mandelbrot distribution to increase to infinity while their ratio converges to a constant. Some examples which illustrate this limit behaviour are presented. [ABSTRACT FROM AUTHOR]

This paper presents a data-driven control design framework to achieve robust tracking without exploiting mathematical model of nonlinear underactuated mechanical systems (UMS). The method leverages differential flatness property of linearised systems, online estimation and compensation of disturbances by active disturbance rejection control. The differentially flat output is derived directly from measured data with unknown dynamics and parameters by the flat output identification algorithm. A reduced nominal model of UMS is proposed to simplify the process of finding flat output and trajectory planning. Technique of sparse regression is applied to identify relationships between flat output and system states, which reduce the order of the well-known extended state observer (ESO) and thereby make the ESO more effective for trajectory planning and tracking in terms of the flat output. The proposed control is validated by experimental studies of a rotary crane system in which a rest-to-rest tracking control is implemented. [ABSTRACT FROM AUTHOR]

In this paper, we investigate a non-linear Langevin equation with periodic, multi-point and non-local fractional integral boundary conditions. The contraction mapping theorem is employed to determine sufficient conditions for the uniqueness of the solution. Also, different results in the existence of solution are demonstrated by using Krasnoselskii and Leray-Schauder theorems. Finally, some examples are provided as applications of the theorems in order to support the main outcomes of this paper. [ABSTRACT FROM AUTHOR]

Smart Interactive Experiences (SIEs) are usage situations enabled by the Internet of Things that empower users to interact with the surrounding environment. The goal of our research is to define methodologies and software environments to support the design of SIEs; more specifically, we focus on design paradigms suitable for experts of given domains, who however might not be experts in technology. In this context, this paper discusses some trade-offs that we identified between six different dimensions that characterise the quality of software environments for SIE design. The trade-offs emerged from the analysis of data collected in an experimental study that compared three different design paradigms to understand in which measure each paradigm supports the creative process for SIE design. After reporting on the study procedure and the data analyses, the paper illustrates how the resulting trade-offs led us to identify alternatives for SIE design paradigms, and to structure on their basis a modular architecture of a software platform where the strengths of the three paradigms can be exploited flexibly, i.e. depending on the constraints and the requirements characterising specific design situations. [ABSTRACT FROM AUTHOR]

The paper presents the results of a study done to find the optimal shapes of matrix element partitioning on three abstract heterogeneous processors when performing multiplication operations. An abstract processor model allows applying the research results in systems with different heterogeneous architectures. To determine the optimal partitioning shape, the work uses non-rectangular candidate shapes identified by Ashley DeFlumere in her work as a result of applying the technology of redistribution of matrix elements between the processors «push»: Square Corner, Rectangle Corner, Square Rectangle, Block Rectangle, L-Rectangle, Traditional 1D Rectangular. The optimality of shapes is determined for four classes of matrix multiplication algorithms: Serial Communication with Barrier (SCB), Parallel Communication with Barrier (PCB), Serial Communication with Bulk Overlap (SCO) and Parallel Communication with Overlap (PCO). The Hockney model was used to evaluate the communication complexity of algorithms. Mathematical models of the algorithm execution time were introduced in the paper for each considered candidate shape in all algorithms. Based on the developed mathematical models, software was developed that allows to select the form of elements partitioning between processors, depending on the ratio of their speeds and latency of the transmission medium. [ABSTRACT FROM AUTHOR]

This paper presents a systematic literature review that explored social work practice with single fathers. The literature search identified 7 studies, both qualitative and quantitative in nature. The small number of studies identified that met the inclusion criteria suggests that single fathers are under-researched in social work, which aligns with their relative invisibility in practice and welfare debates. The findings suggest that social workers did not genuinely or comprehensively understand the needs of single fathers and did not effectively engage with them. This paper's discussion relates these findings to Doucet's interpretations of borderwork and border crossing and relates these concepts to questions of whether social work is inclusive of single fathers or assesses their needs fairly. The discussion is located within wider discourses that propose that societal assumptions about the feminised role of caring and lone parenthood exclude fathers and place responsibility for children primarily on mothers. This paper found that current research into social work with single fathers has not effectively considered the array of social influences on their capacities to parent and thus areas for future research are suggested to promote an agenda of inclusion for single fathers and greater awareness for social work and social work practitioners. [ABSTRACT FROM AUTHOR]

Context: Gamification focuses on the improvement of users' engagement when performing tasks by making use of game mechanics and elements in order to increase their motivations. Many researches have developed gamification models supporting a variety of motivational characteristics to provide engagement solutions for different areas. Objective: This paper carries out a systematic mapping in the field of gamification, looking for models with motivational characteristics in an attempt to characterise the state of the art of this field, identifying gaps and tendencies for further research. Method: We carried out a systematic mapping aiming at finding the primary studies in the existing literature, which were later classified and analysed according to twelve criteria. Results: We analysed 70 papers that resulted in 17 primary studies, published until September 2016. Most of them focus on Education, making use of Gamification to increase the motivation of a learning process. The gamification mechanics and elements most used were Badges/Achievements and Points/ExperiencePoints(XP), and most of the studies were not validated, thus not providing empirical evidence of the impact of gamification. Conclusions: Existing research in the field is somehow preliminary, and more research effort to analyse the applicability of the models and their respective evaluations would be needed. [ABSTRACT FROM AUTHOR]

DC–DC converter finds widespread use in variety of applications. DC–DC converter inherently possess nonlinear dynamics, therefore different linearization schemes are used to get a linearized model of the converter. The classical state-space averaging method is one of the most widely used linearizing method for DC–DC converter. But the said linearization method has some inherent limitation which limits the accuracy of the developed linearized model. This paper provides a discussion of mathematical modeling of DC–DC converter operating in continuous conduction mode as well as in discontinuous conduction mode using exact feedback linearization (EFL) technique which is based on Lie algebra. A linearized model of the converter is obtained using EFL and the effect of change in duty cycle and change in circuit parameters on the frequency response has been studied. The frequency response of the EFL model and nonlinear model is matching within the range of duty cycle and load resistance considered in this paper. [ABSTRACT FROM AUTHOR]

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The purpose of this paper is to update and enhance the 1989 Association for Health Education (AAHE) Scholar presentation, Reflections on Directions in Health Education: Implications for Policy and Practice, at the American Association for Health Education (AAHE) National Convention in Boston. It describes and complements the notion of shifting health from one based on disease and a medical model by advancing our understanding that many premature deaths are preventable and by noting the importance of risk factors with behavioral influences as an important component. However, while recognizing the importance of individual responsibility and personal behavior, it labels the shift to focusing on individual health behaviors as "micro myopia" and highlights several negative implications. It also suggests using a macro approach on a population level that may be equal or more effective and efficient. Recognizing the value and need to incorporate both micro and macro approaches, this article suggests the use of a social ecological model for health promotion that takes into consideration public policy, community, institutional, interpersonal and intrapersonal factors. Health educators should consider utilizing an ecological approach in both practice and professional preparation. As in the 1989 paper, the goal is to stimulate thought and discussion. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive understanding and unique aspects of modelling cemented paste backfill (CPB) behaviour and performance under complex multiphysics conditions. Such modelling is essential for the reliable and cost-effective design of CPB structures. In this review paper, the existing mathematical models are classified into three categories, which are analytical, mechanical constitutive and coupled multiphysics models. For each category, a critical discussion of each model is carried out to identify its applicability and potential further developments with a comparison of the corresponding controlling mechanism. Then, a comparison of the existing models is provided for each category of mathematical models. [ABSTRACT FROM AUTHOR]