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"The EUROCALL Review" is EUROCALL's open access online scientific journal. Regular sections include: (1) Reports on EUROCALL Special Interest Groups: up-to-date information on SIG activities; (2) Projects: reports on on-going CALL or CALL-related R&D projects; (3) Recommended websites: reports and reviews of examples of good practice in language learning website development; (4) Research papers on CALL related topics; (5) Research and Development papers on CALL related topics; (6) Reflective Practice papers on CALL related topics; and (7) Reviews of new books, CALL software, etc. Articles in this issue include: (1) The Future of Foreign Language Instructional Technology: BYOD MALL (Jack Burston); (2) Why and how do distance learners use mobile devices for language learning? (Valérie Demouy, Ann Jones, Qian Kan, Agnes Kukulska-Hulme and Annie Eardley); (3) Variations in motivation, anxiety and boredom in learning English in Second Life (Mariusz Kruk); and (4) Creating an avatar to become a "spect-actor" of one's learning of English for specific purposes (Virginie Privas-Bréauté). "EMMA: Towards multicultural learning" (Ruth Kerr and Ilaria Merciai) describes the project EMMA (http://www.europeanmoocs.eu/). "Aba English App" (Rafael Seiz) provides a recommendation for the mobile language learning application, Aba English. Individual articles contain references.

The article discusses computer simulations of the carbon substance graphene that use the Japanese paper-cutting technique kirigami to create a stretchy and flexible material that preserves the strength of the original material, with comments from researchers Harold Park and Paul McEuen.

One of the most important characteristics of the photovoltaic (PV) modules is their long lifetime (around 25 years). However, recent investigations have shown that PV modules may suffer significant degradation before that time; that is why the development of diagnostic techniques is important for the customers of PV systems. In this paper two indicators to quantify the degradation of a PV module are presented. Such indicators use the single-diode model to represent a PV module without degradation and combine such information with the experimental measurements to estimate the increase in the series resistance and/or the decrease in the parallel resistance with respect to reference values. The estimation of those variations allows the quantification of the module degradation. Simulation results comparing the proposed indicators with the fill factor (a traditional indicator to quantify the electrical quality of a PV module), and other indicators to estimate the series resistance are presented to illustrate the advantages of the proposed indicators. [ABSTRACT FROM AUTHOR]

Looks at the concept of paper space, a two-dimensional world used to make paper prints of the three-dimensional model residing within model space. Setting up the space; Switching between paper space and model space; making scaled, multiple orthographic views of a three dimensional model for a standard drafting style drawing.

Keywords: Ribeirao Preto; Brazil; South America; Nonlinear Science and Numerical Simulation; Drugs and Therapies; Health and Medicine; Mathematics; Therapy EN Ribeirao Preto Brazil South America Nonlinear Science and Numerical Simulation Drugs and Therapies Health and Medicine Mathematics Therapy 1316 1316 1 06/05/23 20230609 NES 230609 2023 JUN 9 (NewsRx) -- By a News Reporter-Staff News Editor at Immunotherapy Weekly -- Investigators discuss new findings in Mathematics - Nonlinear Science and Numerical Simulation. Ribeirao Preto, Brazil, South America, Nonlinear Science and Numerical Simulation, Drugs and Therapies, Health and Medicine, Mathematics, Therapy Keywords for this news article include: Ribeirao Preto, Brazil, South America, Nonlinear Science and Numerical Simulation, Drugs and Therapies, Health and Medicine, Mathematics, Therapy, University of Sao Paulo. [Extracted from the article]

This report discusses advances in computer-based technologies that can be used for teaching limited English proficient (LEP) minority students. These technologies offer multisensory delivery, increased self-expression and active student learning, cooperative learning, communication skill practice, multicultural education, and enhanced motivation. The most promising technologies are described, such as CD-ROM, authoring programs, interactive videodisc, digital audio, local area network computer links, and telecommunications. These technologies can be used for instructional testing and assessment; to teach culture; to help students learn academic content and develop critical learning skills; and to expand students' speaking, listening, reading, and writing skills. Specific examples are given for speaking, listening, reading, writing, culture, and testing. Barriers to implementing these technologies are briefly discussed. Two computer programs are recommended and detailed: Computer Education for Language Learning (CELL) and Alaska Writing Program (AWP). (Contains 20 references.) (NAV)

This annual journal contains nine articles dealing with business education in Louisiana and elsewhere. The articles "Word Processing Competencies: Which Ones Are Really Necessary?" (Patricia Lynn Anderson, Mary Alice Griffin) and "English Basics Were Developed in Shorthand--Why Not in Keyboarding?" (Clora Mae Baker, Marcia A. Anderson-Yates, Grace Abolaji) report studies conducted in Georgia and Illinois, respectively. "National Business and Education Skills Standards: Does Business Education Need Them?" (Phyllis C. Bunn) explores the implications of implementing national skill standards. The articles "Active Learning Techniques for Use in the Vocational Education Classroom" (Donna Holmquist) and "E-Mail Principles that Business Teachers Should Include in Their Curriculum" (Marcia L. James, Robert M. Schramm) both provide practical suggestions for classroom teachers. The need for students to understand other cultures is emphasized in "Technology and International Communication" (M. Latif Javed). The articles "Using Teams in Business Communication Classes" (Laura MacLeod, Sandra J. Nelson) and "Enhancing Computer Simulations through Consensual Business Problem-Solving Formats: Impacts of Student Diversity upon Learning Outcomes" (James L. Morrison) present ideas for classroom projects. "Expanding Business Education Programs: Providing a School-Within-a-School" (Rita Thomas Noel) describes one North Carolina business teacher's efforts to improve business education. Several papers contain substantial bibliographies. (MN)

This annotated bibliography is the sixth annual compilation of the abstracts of 228 documents added to the ERIC database during the year 1991 in the area of computer applications in elementary and secondary schools. The types of materials included are administrator guides, bibliographies, conference papers, evaluative reports, literature reviews, program descriptions, research reports, and teaching guides. The material is presented in four major sections: (1) Computer Assisted Instruction: Overview Documents--24 documents of general discussions on the topic; (2) Special Applications--78 documents divided into 14 categories: Artificial Intelligence/Expert Systems, Cognitive Processing/Thinking Skills, Computer Literacy, Computer Networks, Computer Equity, Counseling and Guidance, Courseware and Software, Ethics, Interactive Video, Keyboarding, Logo, Management/Administration, Conference Proceedings, Research, Simulation, and Testing; (3) Subject Areas--85 documents concerned with computer applications in the areas of business, English as a Second Language and foreign languages, language arts, mathematics, music, reading, science, social studies, vocational education, and writing; (4) Special Populations--37 documents on computer applications for adult education, disabled learners, disadvantaged learners, gifted students, and early childhood education. Individual documents are presented alphabetically by author, or title when no personal author is available, within each section. Each entry includes the title and author of the document, information on price, and availability, the publication type, major ERIC descriptors, and an abstract. An alphabetical title of authors and information on ordering ERIC documents are included. (ALF)

In this paper, the H ∞ anti-synchronization problem of switching inertial neural networks with constant leakage delays and time-varying mixed delays is addressed. A direct analysis method based on parameterized system solutions is proposed to solve the problem we studied. The advantages of this method are that the variable substitution is not required for the system model and no Lyapunov–Krasovskii functional is constructed, which simplifies the proof process. In addition, the resulting anti-synchronization conditions consisting of some simple scalar inequalities can be easily solved by business softwares, and less computational complexity is involved. It is worth noting that the problem addressed in this paper has not been studied at present, and the limitation on the parity of activation functions in the existing literatures is removed, which reduces conservativeness. Finally, the reliability of the theoretical results is verified by numerical simulations. [ABSTRACT FROM AUTHOR]

The article reports on some professional activities taking place in the United States related to computer science. As a cooperative venture undertaken by 15 organizations, the "National Educational Computing Conference," held in Kansas City, Missouri, has presented a major work regarding computers in instruction to promote interaction among all levels in computer uses in education. It also intends to develop and coordinate the various professional groups involved with computer uses in instruction and to produce a proceedings documenting the status of computers in education. Papers are invited from individuals representing all academic disciplines and research areas in educational computing. It further reports that papers describing original research in the formal analysis of computing problems are being sought for the "Fourteenth Annual Association for Computing Machinery Symposium on Theory of Computing," held during May 5-7, 1982, in San Francisco, California. The Fifteenth Annual Simulation Symposium is to be held during March 17-19, 1982, in Tampa, Florida. The list contains information about some other activities as well.

This paper presents a COordinate Rotation Digital Computer (CORDIC)-based architecture for the computation of Nth root and proves its feasibility by hardware implementation. The proposed architecture performs the task of Nth root simply by shift-add operations and enables easy tradeoff between the speed (or precision) and the area. Technically, we divide the Nth root computation into three different subtasks, and map them onto three different classes of the CORDIC accordingly. To overcome the drawback of narrow convergence range of the CORDIC algorithm, we adopt several innovative methods to yield a much improved convergence range. Subsequently, in terms of convergence range and precision, a flexible architecture is developed. The architecture is validated using MATLAB with extensive vector matching. Finally, using a pipelined structure with fixed-point input data, we implement the example circuits of the proposed architecture with radicand ranging from zero to one million, and achieve an average mean of approximately 10−7 for the relative error. The design is modeled using Verilog HDL and synthesized under the TSMC 40-nm CMOS technology. The report shows a maximum frequency of 2.083 GHz with $197421.00~{\mu }\text{m}^{2}$ area. The area decreases to $169689.98~{\mu }\text{m}^{2}$ when the frequency lowers to 1.00 GHz. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to verify results related to losses in the core of a brushless DC prototype motor, obtained using its computer FE models, by experimental tests on manufactured machines. The paper focuses on the comparison of losses in the core of a machine with a classical stator core made of an iron–silicon material (Fe–Si) and a new one made of a modern METGLAS material. Design/methodology/approach: Computer models of the prototype motors were created using FEM. The designed machines were manufactured, and experimental tests were performed. To achieve high frequencies in rotating magnetic fields, motors with a stator to rotor pole ratio of 9/12 were built. Twin rotor approach was applied, as two identical rotors were built along the two geometrically identical stators made of different core materials. Findings: Experimental studies have shown the superiority of the METGLAS material over the classical Fe–Si material. Material parameters were measured directly on the prepared cores as library data used in the simulation may be incorrect due to technological processes during core production, which was also verified. Problems related to twin rotor approach have been identified. Solution to the problem has been suggested. Necessity of 3D FEM modelling was identified. Originality/value: The main source of originality is that METGLAS material used in the prototype machines was developed and manufactured by the authors themselves. Original approach to core parameter evaluation based on simplified methodology has been suggested. Another original part is a simplified methodology applied to loss measurement during no-load test. [ABSTRACT FROM AUTHOR]

This paper adopts a quantization-dependent Lyapunov function to study the output feedback stabilization problem of a switched system subject to output event-triggered sampling and quantization. First, a new event-triggered mechanism related to quantization parameters is proposed, which can obtain a trade-off between the event-triggered frequency and quantization density on the premise of ensuring asymptotic stability of the switched system. Moreover, sufficient conditions are obtained to ensure asymptotic stability of the switched system by a quantization-dependent Lyapunov function. Lastly, through a numerical simulation and PWM-driven boost converter system, we demonstrate the availability of the proposed quantization-dependent Lyapunov function and event-triggered mechanism methods based on quantization parameters, respectively. [ABSTRACT FROM AUTHOR]

• Correct an error in our paper published in Communications in Nonlinear Science and Numerical Simulation in 2015. • Construct a new Z 2 -equivariant cubic switching system and prove the existence of 15 limit cycles. • An approach is described for calculating the focus values of systems with two switching lines. In this note, we correct an error in our paper published in Communications in Nonlinear Science and Numerical Simulation in 2015 [5], in which the form of a Z 2 -equivariant cubic planar switching system is not correct. In this note, we add one more switching line and use the same equations given in [5] to construct a correct Z 2 -equivariant cubic system. Then, we prove that the new system can exhibit 15 limit cycles and therefore the conclusion given in [5] still holds. [ABSTRACT FROM AUTHOR]

In this article the author talks about mentorship and assigning mentors for better learning with hare-brained ideas. Topics discussed include face-to-face, sustained and providing the mentee with greater relevant knowledge; authenticity with listening in position to benefit from a mentor; and terminate the mentor-to-mentee relationship and maintain a professional relationship.

Purpose: The paper aims to assess the feasibility of locally turbulence-resolving flow simulations for a high-lift aircraft configuration near maximum lift. It addresses the aspects of proper grid design and explores the ability of the hybrid turbulence model and the numerical scheme to automatically select adequate modes in different flow regions. By comparison with experimental and numerical reference data, the study aims to provide insights into the predictive potential of the method for high-lift flows. Design/methodology/approach: The paper applies numerical flow simulations using well-established tools such as DLR's (German Aerospace Center) TAU solver and the SOLAR grid generator to study "Improved Detached Delayed Eddy Simulations" of the Japan Aerospace Exploration Agency (JAXA) Standard Model at two angles of attack near maximum lift. The simulations apply a hybrid low-dissipation low-dispersion scheme and implicit time stepping with adequate temporal resolution. The simulation results, including pressure distributions and near-wall flow patterns, are assessed by comparison with experimental wind-tunnel data. Findings: Apart from demonstrating the general feasibility of the numerical approach for complex high-lift flows, the results indicate somewhat improved maximum lift predictions compared to the Spalart–Allmaras model, which is consistent with a slightly closer agreement with measured pressure distributions and oil-flow pictures. However, the expected lift breakdown caused by an increasing inboard separation in the experiment is not well captured. Originality/value: The study not only provides new insight into the feasibility and promising potential of hybrid turbulence-resolving methods for relevant high-lift aircraft flows but also indicates the need for further research on the numerical sensitivities, such as grid resolution or flow initialization. [ABSTRACT FROM AUTHOR]

Purpose: Natural gas leak from underground pipelines could lead to serious damage and global warming, whose spreading in soil should be systematically investigated. This paper aims to propose a three-dimensional numerical model to analyze the methane–air transportation in soil. The results could help understand the diffusion process of natural gas in soil, which is essential for locating leak source and reducing damage after leak accident. Design/methodology/approach: A numerical model using finite element method is proposed to simulate the methane spreading process in porous media after leaking from an underground pipe. Physical models, including fluids transportation in porous media, water evaporation and heat transfer, are taken into account. The numerical results are compared with experimental data to validate the reliability of the simulation model. The effects of methane leaking direction, non-uniform soil porosity, leaking pressure and convective mass transfer coefficient on ground surface are analyzed. Findings: The methane mole fraction distribution in soil is significantly affected by the leaking direction. Horizontally and vertically non-uniform soil porosity has a stronger effect. Increasing leaking pressure causes increasing methane mole flux and flow rate on the ground surface. Originality/value: Most existing gas diffusion models in porous media are for one- or two-dimensional simulation, which is not enough for predicting three-dimensional diffusion process after natural gas leak in soil. The heat transfer between gas and soil was also neglected by most researchers, which is very important for predicting the gas-spreading process affected by the soil moisture variation because of water evaporation. In this paper, a three-dimensional numerical model is proposed to further analyze the methane–air transportation in soil using finite element method, with the presence of water evaporation and heat transfer in soil. [ABSTRACT FROM AUTHOR]

Purpose: Electrospinning is a method of the polymer super thin fibres formation by the electrostatic field. The distribution of electrostatic field affects the effectiveness of the electrospinning. Design/methodology/approach: This paper presents various computer models that can improve the electrospinning process. The possibilities of modelling the electrostatic field in the design of electrospinning equipment are presented. Findings: In the research part, the one focussed on finding a cylinder-shaped collector structure to limit the adverse effect of an uneven distribution of the electric field intensity on the collector. Originality/value: The paper concerns the improvement of the electrospinning process with the use of electrostatic field modelling. In the first part, several possible applications of electrostatic models have been indicated, thanks to which the efficiency of the process has been improved. The original solution of the collector geometry was presented, which according to the authors, in comparison with previous models, gives the most promising results. In this solution, it was possible to obtain an even distribution of the electric field intensity while removing the unfavourable effect of the field strength increase on the outer edges of the collector. The most important aspect in this paper is electric field strength analysis. [ABSTRACT FROM AUTHOR]

This paper deals with investigating the maximum number of frequencies generated by an oscillator in the case that a half number of integrators in the conventional dynamic structure of this oscillator are replaced by fractional integrators with an identical order. First, an upper bound for the maximum number of frequencies, which can exist in a steady state response of the oscillator, with respect to the number of integrators, is obtained. Then, on the basis of the recent advances in the field of determinant-based representations of bivariate polynomials, a lower bound is found for the maximum number of sinusoidal components in the steady state oscillations generated by the oscillator. A systematic algorithm is also introduced to find a dynamic structure and its dynamic matrices for realization of an oscillator, such that the number of distinct frequencies in its steady state oscillations is equal to the obtained lower bound. Numerical simulation results are presented to validate the introduced algorithm. Moreover, an idea for improving the lower bound is proposed. Finally, the paper is closed by describing some related open problems that invite future research works. [ABSTRACT FROM AUTHOR]

Precision oscillators are ubiquitous in modern electronic systems, and their accuracy often limits the performance of such systems. Hence, a deep understanding of how oscillator performance is quantified, simulated, and measured, and how it affects the system performance is essential for designers. Unfortunately, the necessary information is spread thinly across the published literature and textbooks with widely varying notations and some critical disconnects. This paper addresses this problem by presenting a comprehensive one-stop explanation of how oscillator error is quantified, simulated, and measured in practice, and the effects of oscillator error in typical oscillator applications. [ABSTRACT FROM AUTHOR]

The sixth report and first annual update in a series of selected ERIC bibliographies on computer-based education begun in 1973, this report provides 213 citations and abstracts from the 346 relevant documents entered in the ERIC system in 1986. The emphasis in selection was on documents that focus broadly on the topic of computer-based education (CBI) and provide information to aid in the decision-making process. Because of the size of the database, documents pertaining specifically to CBI in universities and colleges have not been included. Materials appearing in this bibliography are presented under four broad headings: (1) Computer-Assisted Instruction, which includes overview documents, conference proceedings, and papers on developing computer-based instruction, including videodisc interactive courseware; (2) Special Applications, including computer literacy, copyright and computer software, computer equity, software evaluation, computer use in counseling and guidance, management applications, computer networking, computer testing, and trends in CBI; (3) Subject Applications, which covers basic skills, business education, English as a second language and foreign languages, language arts, LOGO, mathematics, reading, science, social studies, and vocational education; and (4) Special Populations, i.e., adult or distance education students and handicapped learners. An author index is provided, as well as information for ordering ERIC documents. (EW)

The fifth in a series of selected ERIC bibliographies on computer-based education begun in 1973, Computer-Based Education: The Best of ERIC, 1983-1985 provides citations and abstracts for over 250 documents selected from the more than 500 that were entered in the ERIC files over the three-year period. The emphasis in selection was on documents that focus broadly on the topic of computer-based education and provide information to aid in the decision-making process. Because of the size of the database, documents pertaining specifically to computer-based education in universities and colleges have not been included. Materials appearing in this bibliography are presented under four broad headings: (1) Computer-Assisted Instruction, which includes overview documents, conference proceedings, and papers on developing computer-based instruction; (2) Special Applications, including computer literacy, evaluation, guidance, management/planning, research, and study skills; (3) Subject Applications, which cover agriculture, basic skills, bilingual education and English as a second language, business education, fine arts, foreign languages, language arts, mathematics, reading, science, social studies, and vocational education; and (4) Special Populations, i.e., adult or distance education, handicapped learners, and incarcerated learners. An author index is provided as well as information for ordering ERIC documents. (BBM)

In this paper, the robust coordination control of multi-agent systems (MASs) with uncertainties is considered, where the uncertainties include the external disturbances and the measurement noises as well as the unknown initial states. Motivated by the interval observer of single-agent systems, a distributed interval observer is designed for MASs communicating through a directed network which contains a directed spanning tree by using only the bounding information on the uncertainties and the output information, to implement the interval-valued state estimation on the absolute state of each agent. It also finds that the robust coordination control is a by-part of the distributed interval observer design of this kind of MASs. Moreover, a time-invariant transformation is used to perfect the distributed interval observer design. Finally, numerical simulations are proposed to verify the theoretical results. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to propose a new method for robust simulations of passive heat transfer in two-fluid flows with high volumetric heat capacity contrasts. Design/methodology/approach: This paper implements a prediction–correction scheme to evolve the volumetric heat capacity. In the prediction substep, the volumetric heat capacity is evolved together with the temperature. The bounded downwind version of compressive interface capturing scheme for arbitrary meshes and central difference scheme are used for the spatial discretization of the advection and diffusion terms of the heat transfer equation, respectively. In the correction substep, the volumetric heat capacity is updated in accordance with the interface captured by using a coupled level-set and volume-of-fluid method to capture the interface dynamics precisely. Findings: The proposed method is verified by simulating the advection of a hot droplet with high volumetric heat capacity, a stationary air–water tank with temperature variation between top and bottom walls and heat transfer during wave plunging at Re=108. The test results show that the proposed method is practical and accurate for simulating two-fluid heat transfer problems, especially for those feature high volumetric heat capacity contrasts. Originality/value: To ensure the numerical stability, this paper solves an additional conservative form of volumetric heat capacity equation along with the conservative form of temperature equation by using consistent spatial-discretization and temporal-integration schemes. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to investigate the effects of the shear-thinning viscoelastic behavior of the surrounding matrix on droplet deformation by weakly compressible smoothed particle hydrodynamics (WC-SPH). Also, the effect of the presence of another droplet is examined. Design/methodology/approach: A modified consistent weakly compressible SPH method is proposed. After code verification, a complete parameter study is performed for a drop under the simple shear flow of a Giesekus liquid. The investigated parameters are 0.048≤Ca ≤ 14.4, 0.1≤c ≤ 10, 0.04≤De ≤ 10, 0≤α ≤ 1 and 0.12≤Re ≤ 12. Findings: It is demonstrated that the rheological behavior of the surrounding fluid could dramatically affect the droplet deformation. It is shown that the droplet deformation is increased by increasing Re and Ca. In contrast, the droplet deformation is decreased by increasing a, De and polymer content. Also, it is indicated the presence of another droplet could drastically affect the flow field, and the primary stress difference (N1) is resonated between two droplets. Originality/value: The main originality of this paper is to introduce a new consistent WC-SPH algorithm. The proposed method is very versatile for tackling the shear-thinning viscoelastic multiphase problems. Furthermore, a complete parameter study is performed for a drop under the simple shear flow of Giesekus liquid. Another novelty of the current paper is studying the effect of the presence of a second droplet. To the best of the authors' knowledge, this is performed for the first time. [ABSTRACT FROM AUTHOR]

The frequency-domain adaptive filter (FDAF) has been utilized in various applications where the length of the modeling filter is very long. The convergence behavior of the FDAF in the full-modeling case has been well analyzed. However, because the length of the true filter may be rather long and is unknown in practice, the length of the adaptive filter is usually less than that of the true system. In this paper, only the statistical behavior of the deficient-length constrained FDAF was analyzed for Gaussian inputs. This paper presents a unified approach to the stochastic analysis of a family of the FDAF in an under-modeling situation and for arbitrary input distributions. Specifically, the mean and mean-square convergence behaviors of FDAFs are presented, and the closed-form expression of the steady-state misalignment is given. Our theoretical results provide some new insights into the convergence property of deficient-length FDAFs. In addition, the analysis is carried out in the frequency domain directly. Computer simulations indicate an excellent agreement with our theoretical predictions. [ABSTRACT FROM AUTHOR]

This paper investigates the exponential synchronization (ES) problem for complex networks (CNs) under an intermittent adaptive event-triggered control (IAE-TC) strategy which is based on dynamic IAE-TC during the control activation intervals. In this control mechanism, the intermittent controller has adaptability to the evolution results of the controlled networks and is activated only when the event-triggered condition is violated. Then, by employing this kind of control strategy and the Lyapunov method, some sufficient conditions are proposed to achieve the ES of CNs and it is proven that the Zeno behavior can be eliminated. Besides, an application about the islanded microgrid system and some numerical simulations are provided to verify the effectiveness of the derived theoretical results. Moreover, in the numerical simulations, it is shown that the dynamic IAE-TC strategy can decrease the number of event-triggered instants more availably than the static one. [ABSTRACT FROM AUTHOR]

In this paper, we are concerned with the dynamic feedback design for linear systems with input disturbance. We propose a new approach to design dynamic feedback such that the disturbance in the control channel can be compensated effectively. An interesting characteristic about the disturbance robustness of dynamic feedback is found. Thanks to this interesting characteristic, we just need to consider the disturbance-free system to make the dynamic feedback design. This fact is well validated by several dynamic feedback laws proposed in this paper. Our results are available for the regular linear system with harmonic disturbance. Moreover, the stabilization of an unstable heat equation with general periodic disturbance is also investigated. In order to validate the theoretical results visually, some numerical simulations are given to show the effectiveness of the proposed dynamic feedback. [ABSTRACT FROM AUTHOR]

In this paper, we construct an improved Implicit–Explicit (IMEX) numerical scheme based on the conservation form of the advection–diffusion equations and study the numerical stability of the method in case of a nonlinear advection–diffusion Lotka–Volterra model. The classical numerical methods might be unsuitable for providing accurate numerical results for advection–diffusion problem in which advection dominates diffusion. An improved numerical scheme is proposed, which can preserve the positivity for arbitrary stepsizes. The convergence, boundedness, existence and uniqueness of the numerical solutions are investigated in paper. A threshold value denoted by R 0 Δ x , is introduced in the stability analysis. It is shown that the numerical semi-trivial equilibrium is locally asymptotically stable if R 0 Δ x < 1 and unstable if R 0 Δ x > 1. Moreover, the limiting behaviors of the threshold value are exhibited. Finally, some numerical simulations are given to confirm the conclusions. [ABSTRACT FROM AUTHOR]

The non-ordinary state-based peridynamic (NOSB-PD) method has significant advantages in solving crack propagation problems due to its non-local characteristics, but it also faces problems such as numerical oscillations and boundary effects. In order to solve the above defects, the paper first discusses the NOSB-PD method within the Galerkin framework. After that, the peridynamic differential operator (PDDO) approximation was introduced by extending the calculation of the deformation gradient tensor F in NOSB-PD. Since the zero-order approximations in the PDDO approximation and the reproducing kernel (RK) approximation are identical, the distinctions between the two approximations have been thoroughly analysed. Although the two approximations show the same consistency, only the RK approximation satisfies the integrable condition. Therefore, a RK-PD coupling method is proposed in the paper, and an implicit iterative algorithm suited to the RK-PD method is presented as well. At last, several numerical examples demonstrate that the proposed method does not suffer from numerical oscillations and can be used to solve the three-dimensional crack propagation problems. [ABSTRACT FROM AUTHOR]

This paper deals with modeling and simulation of a new family of two-terminal devices fabricated with vanadium dioxide material. Such devices allow realization of very compact relaxation nano-oscillators that can be connected electronically to form arrays of coupled oscillators. Challenging applications of oscillator arrays include the realization of multiphase signal generators and massively parallel brain-inspired neurocomputing. In the paper, a circuit-level model of the vanadium dioxide device is provided which enables extensive electrical simulations of oscillator systems built on the device. The proposed model is exploited to explain the dynamics of vanadium dioxide relaxation oscillators as well as to accomplish a robust parameter design. Applications to the realization of voltage-controlled oscillators and of multiphase oscillator arrays are illustrated. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel approach for discretizing the derivative Nonlinear Schrödinger (DNLS) equation in an integrable manner. Our proposed method involves discretizing the time variable, resulting in a discrete system that converges to the DNLS equation in a natural limit. Furthermore, the discrete system retains the same set of infinitely conserved quantities as the original DNLS equation. To demonstrate the effectiveness of our proposed method, we designed a numerical simulation scheme using the Fourier Pseudo-spectral Method to discretize the spatial variable. The numerical results confirm that our new discrete integrable scheme can accurately preserve the conserved quantities of the DNLS equation. [ABSTRACT FROM AUTHOR]

In this paper, considering the spatial propagation behavior of Internet rumor, we propose a new reaction–diffusion rumor propagation model with time delay in social networks. Based on this, we discuss the stability conditions at the equilibrium point and analyze the Turing instability for the approximation propagation system. Simultaneously, the amplitude equations for the approximation system are derived by multiscale analysis. We use numerical simulation to compare the effect of parameter size, period, and time delay on the patterns. Moreover, we compare the different reactivity of the system in the W S networks and the B A networks. Finally, we plot the corresponding amplitude equations patterns by controlling the parameters and verify the correctness of the theoretical results. [ABSTRACT FROM AUTHOR]

Computer modeling represents the coating and drying processes in mathematical language and then solves the resulting equations. It frequently involves suitably approximating or idealizing the process so the equations are [...]

The main focus of this paper is the evolution of complex behavior in a system of coupled nonlinear memristor circuits depending on the applied coupling conditions. Thereby, the parameter space for the local activity and the edge-of-chaos domain will be determined to enable the emergence of the pattern formation in locally coupled cells according to Chua’s principle. Each cell includes a Niobium oxide-based memristor, which may feature a locally active behavior once it is suitably biased on the negative differential resistance region of its DC current-voltage characteristic. It will be shown that there exists a domain of parameters under which each uncoupled cell may become locally active around a stable bias state. More specifically, under these conditions, the coupled cells are on the edge-of-chaos, and can support the static and dynamic pattern formation. The emergence of such complex spatio-temporal behavior in homogeneous structures is a prerequisite for information processing. The theoretical results are confirmed by measurements as well as by the numerical simulations of the accurate device and circuit models. [ABSTRACT FROM AUTHOR]

This paper investigates the position and attitude tracking control problem of a quadrotor unmanned aerial vehicle subject to modeling uncertainties and actuator failures. A comprehensive mathematical model reflecting the nonlinearity and state-space coupling of the dynamics as well as actuation faults and external disturbances is derived. By combining the radial basis function neural networks (NNs) with virtual parameter estimating algorithms, an indirect NN-based adaptive fault-tolerant control scheme is developed, which exhibits several attractive features as compared with most existing methods: 1) it is not only robust and adaptive to nonparametric uncertainties but also tolerant to unexpected actuation faults; 2) it ensures stable tracking without the need for precise information on system model; and 3) it only involves one lumped parameter adaptation, thus is structurally simpler and computationally less expensive, rendering the resultant scheme less demanding in programming and more affordable for onboard implementation. The effectiveness and benefits of the proposed method are confirmed via computer simulation. [ABSTRACT FROM AUTHOR]

The technology for oxide resistive memories offers nowadays a number of different implementations and solutions. As a consequence, many models have been presented so far, generally technology-specific, representing a problem for the memory design standardization. Moreover, the computational effort can be reduced using memristive models with lower complexity but that grant at the same time good speed and numerical stability. In this paper, the authors try to find a compromise between accuracy and computational costs, proposing a simulation procedure based on a linear approximation of the memristive device model. The description, formally derived from the traditional linear model, has been implemented in Verilog-A and, thanks to the analysis of practical design cases on a reference architecture, has been demonstrated to be useful in highlighting critical parasitic effects related to the interaction of the memristive cells with the memory circuit periphery. Thanks to the approximated method, a computer simulation time saving up to 40% is achieved when simulating a full cross-bar memory device. The model parameters have been extracted from experimental curves obtained from HfO2 devices implemented in a 250-nm BiCMOS IHP technology. [ABSTRACT FROM AUTHOR]

Although the multiband-structured subband adaptive filter (MSAF) and its convergence analysis have been widely studied, the existing analyses are carried out only in the decimated time domain. In this paper, we present a new theoretical mean-square analysis of the multi-sampled MSAF (MS-MSAF) algorithm in the original time domain, whereas the MS-MSAF algorithm extends the original sub-sampled number to a general value. Both the transient and steady-state performances are investigated, which provides a guideline for increasing the convergence rate of the MSAF. Then, the tracking ability is studied in a non-stationary environment. Moreover, the approximative analytical minimum mean-square deviation and optimum step size are derived. Simulation results illustrate the derived performance expressions, which show that there is a relatively good match between theory and practice. [ABSTRACT FROM AUTHOR]

This paper presents a rescheduled dataflow of convolution and its hardware architecture that can enhance energy efficiency. For convolution involving a large amount of computations and memory accesses, previous accelerators employed parallel processing elements to meet real-time constraints. Though the previous approaches made a success in implementing complex convolution models, they load the same input features and filter weights from on-chip memories multiple times due to the iterative property of convolution operations, suffering from high energy consumption. To mitigate redundant memory accesses, a novel dataflow is proposed that computes convolution operations incrementally so as to reuse the loaded data as maximally as possible. In addition, several convolution accelerators supporting the rescheduled dataflow are investigated, and qualitative and quantitative analyses are performed to suggest a promising candidate for various convolution models. Simulation results show that the energy efficiency of the proposed accelerator outperforms that of the previous accelerator significantly. [ABSTRACT FROM AUTHOR]

This paper extends the use of the regenerative property of queueing systems in the analysis of simulation output. In particular, it describes a sequential estimation method which when used with the regenerative property allows results to be obtained with specified statistical accuracy. This method includes a test to check the normality assumption on which the sequential procedure relies. The paper illustrates the method using the empty and idle state as the regenerative state. A second example then describes how using the most frequently entered state as the regenerative state reduces the chance of making a costly error in a preliminary simulation run. The paper also described how a variance reduction method due to Page [9] can be used to obtain a specified accuracy with considerably fewer job completions than are required when no variance reduction technique is applied. [ABSTRACT FROM AUTHOR]

Over the last decades, the cooperative design of complex networked systems has received an increasing attention in real-world engineering practices. Traditionally, each node in the network is assumed to obtain the same signal. However, each agent often possesses different measurement due to the observability or configuration of the systems. To solve the stabilization problem in this case, we aim to establish a unified framework for the cooperative control of complex network with distributed observers. In detail, different from the traditional centralized design, this paper initiates a cooperative approach by only using the local information of the networked systems. In allusion to the three kinds of representative networks, this paper establishes some sufficient or necessary conditions for the existence of network parameters that guarantee the stabilization of the LTI plants. Moreover, some corresponding algorithms are developed to find the suitable parameters of networked observers. Last but not least, numerical simulations are also provided to verify the above theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, the resilient control for linear discrete-time multi-agent networks subjected to unconfined cyber-attacks is investigated based on a data-driven method. Firstly, according to the evolution of the original network dynamics, a distributed data-driven estimation algorithm is presented. On this basis, a switching control law is proposed to solve the resilient consensus problem for the discrete-time multi-agent network under unconfined cyber-attacks. Further, some necessary and sufficient conditions for designing the resilient controllers are obtained by solving a nonlinear matrix inequation. Secondly, the proposed data-driven method is extended to study the resilient tracking control and formation control problems. Finally, some numerical simulations are provided to verify the effectiveness of the data-driven resilient control method. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to discuss a new form of the Adomian decomposition technique for the numerical treatment of Bratu's type one-dimensional boundary value problems (BVPs). Moreover, the author also addresses convergence and error analysis for the completeness of the proposed technique. Design/methodology/approach: First, the author discusses the standard Adomian decomposition method and an algorithm based on Duan's corollary and Rach's rule for the fast calculation of the Adomian polynomials. Then, a new form of the Adomian decomposition technique is present for the numerical simulation of Bratu's BVPs. Findings: The reliability and validity of the proposed technique are examined by calculating the absolute errors of Bratu's problem for some different values of Bratu parameter λ. Numerical simulation demonstrates that the proposed technique yields higher accuracy than the Bessel collocation and other known methods. Originality/value: Unlike the other methods, the proposed technique does not need linearization, discretization or perturbation to handle the non-linear problems. So, the results obtained by the present technique are more physically realistic. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to introduce a modern higher efficiency predictor–corrector iterative algorithm. Design/methodology/approach: Furthermore, the efficiency of new algorithm is analyzed on the based on Chun-Hui He's iteration method. Findings: In comparison with the current robust algorithms, the newly establish algorithm behaves better and efficient, whereas the current existing algorithm fails or slows in the considered test examples. Practical implications: The modified Chun-Hui He's algorithm has great practical implication in numerous real-life challenges in different area of engineering, such as Industrial engineering, Civil engineering, Electrical engineering and Mechanical engineering. Originality/value: The paper presents a modified Chun-Hui He's algorithm for solving the nonlinear algebraic models exist in various area. [ABSTRACT FROM AUTHOR]

Purpose: The subject of the fractional calculus theory has gained considerable popularity and importance due to their attractive applications in widespread fields of physics and engineering. The purpose of this paper is to present results on the numerical simulation for time-fractional partial differential equations arising in transonic multiphase flows, which are described by the Tricomi and the Keldysh equations of Robin functions types. Design/methodology/approach: Those resulting mathematical models are solved by using the reproducing kernel method, which provide appropriate solutions in term of infinite series formula. Convergence analysis, error estimations and error bounds under some hypotheses, which provide the theoretical basis of the proposed method are also discussed. Findings: The dynamical properties of these numerical solutions are discussed and the profiles of several representative numerical solutions are illustrated. Finally, the prospects of the gained results and the method are discussed through academic validations. Originality/value: In this paper and for the first time: the authors presented results on the numerical simulation for classes of time-fractional PDEs such as those found in the transonic multiphase flows. The authors applied the reproducing kernel method systematically for the numerical solutions of time-fractional Tricomi and Keldysh equations subject to Robin functions types. [ABSTRACT FROM AUTHOR]

An important problem in terrain analysis is modeling how water flows across a terrain and creates floods by filling up depressions. In this paper, we study a number of flood-risk related problems: given a terrain Σ, represented as a triangulated xy-monotone surface with n vertices, a rain distribution, and a volume of rain ψ, determine which portions of Σ are flooded. We give an overview of efficient algorithms for these problems as well as explore the efficacy and efficiency of these algorithms on real terrains. [ABSTRACT FROM AUTHOR]