Boundary Control Research Articles

Internal and Boundary Control of Piezoelectric Beams with Magnetic Effects and Voltage Controller: Exponential and Polynomial Decay Rates

Internal and Boundary Control of Piezoelectric Beams with Magnetic Effects and Voltage Controller: Exponential and Polynomial Decay Rates

Boundary disturbance rejection for Caputo-Hadamard fractional heat equations via ADRC approach

This paper focuses on the boundary control matched disturbance rejection problem for Caputo-Hadamard fractional heat equations with time delay. By utilizing the novel idea of the active disturbance rejection control (ADRC) approach, two infinite-dimensional systems are constructed. One separates the disturbance from the control input, and the other estimates the unknown disturbance without high gain. By employing the backstepping method, together with the disturbance-compensator, a desired stabilizing controller is designed, and the asymptotical stability is achieved for the original system.

Linearized boundary control method for density reconstruction in acoustic wave equations

Linearized boundary control method for density reconstruction in acoustic wave equations

Rotational shallow water equations with viscous damping and boundary control: structure-preserving spatial discretization

Rotational shallow water equations with viscous damping and boundary control: structure-preserving spatial discretization

Adaptive neural boundary control for multi-agent manipulators system with uncertainties through cooperative disturbance observers network

This paper addresses vibration control problem of multi-agent flexible manipulators systems in the presence of simultaneous uncertainty and unknown external disturbance. Particularly, the goal is to suppress vibration of both flexible link and joint angular. In this paper, the dynamic model of the considered flexible manipulator is described by the fourth order partial differential equation. Without control, the system is unstable and vibrate constantly due to initial states, the external unknown disturbances and system uncertainties. To compensate the uncertainty in each agent, the neural networks are employed and novel adaptation laws are developed to update weighting parameters in the neural networks. While for the compensation of the external disturbance a cooperative network of disturbance observers is proposed to enhance the observation reliability. With the resulting estimations of uncertainties and the unknown disturbance, adaptive distributed boundary controllers are derived to suppress vibration in-domain and keep joint angular position to zero. The closed-loop system is proven to be uniform ultimately bounded through Lyapunov stability theory. Numerical simulations result shows that compared with the proportional–derivative control, the proposed method almost reduces all overshoot and steady-state error.

Machine learning interatomic potential with DFT accuracy for general grain boundaries in α-Fe

To advance the development of high-strength polycrystalline metallic materials towards achieving carbon neutrality, it is essential to design materials in which the atomic level control of general grain boundaries (GGBs), which govern the material properties, is achieved. However, owing to the complex and diverse structures of GGBs, there have been no reports on interatomic potentials capable of reproducing them. This accuracy is essential for conducting molecular dynamics analyses to derive material design guidelines. In this study, we constructed a machine learning interatomic potential (MLIP) with density functional theory (DFT) accuracy to model the energy, atomic structure, and dynamics of arbitrary grain boundaries (GBs), including GGBs, in α-Fe. Specifically, we employed a training dataset comprising diverse atomic structures generated based on crystal space groups. The GGB accuracy was evaluated by directly comparing with DFT calculations performed on cells cut near GBs from nano-polycrystals, and extrapolation grades of the local atomic environment based on active learning methods for the entire nano-polycrystal. Furthermore, we analyzed the GB energy and atomic structure in α-Fe polycrystals through large-scale molecular dynamics analysis using the constructed MLIP. The average GB energy of α-Fe polycrystals calculated by the constructed MLIP is 1.57 J/m2, exhibiting good agreement with experimental predictions. Our findings demonstrate the methodology for constructing an MLIP capable of representing GGBs with high accuracy, thereby paving the way for materials design based on computational materials science for polycrystalline materials.

Time–space control: explaining subnational variation in Thailand’s guestwork regimes

Abstract How do states control labor migration? Furthering global trends, nation states increasingly seek to include foreigners in labor markets while excluding them from settling. Yet, dominant theories maintain a limited conception of migration control as primarily immigrant restriction, especially in the global North. Thailand offers a paradigmatic case for understanding labor migration control and the dual goal of inclusion–exclusion it entails. While migrants generally face rigid limits on their immigration status, the Thai state shows internal variation in how it manages their inclusion as workers: in some places, authorities more strictly regulate time limits of documents, while in others, they focus on control of boundaries around migrant spatial access. Drawing from ethnographic fieldwork in two sites, this article examines this regulatory variation to inform a more general understanding of guestwork control in global context. Comparing two subnational regimes, I show that the state must respond to multiple forces from above and below when controlling labor migration, requiring subnational regulatory differences, and fostering contrasting means of labor reproduction. Findings suggest that differential subnational incorporation into regional and global economies can shape differences in the time–space control of migrant workers and the conditions of noncitizenship that come with it.

Active boundary control of spinning beams with elastic constraints using piezoelectric stack actuator

A spinning beam structure is usually subjected to severe vibration. To suppress this vibration, piezoelectric stacking actuators are installed on the boundary of the spinning beam. Here, an active boundary control model for the vibration of spinning beam structures with elastic constraints is established. The dynamic equation of motion of the coupled system is derived by combining the Lagrange equation with the modified Fourier series method. An active control strategy is used to suppress the vibration of the spinning beam with elastic constraints. The vibration suppression effect of the proposed method under different spinning speeds and different elastic boundary conditions is discussed. It is proven that the current active control scheme can quickly suppress the vibration of the spinning beam structure with elastic constraints. The present control method can provide a new way to suppress the vibrations of spinning beam structures with nonideal boundaries in practical engineering.

Vegetation restoration strategies in arid or semi-arid regions-From the perspective of optimal control.

Inappropriate human activities contribute to the degradation of ecosystems in arid or semi-arid regions. Therefore, emphasizing the importance of strategies for restoring vegetation in these areas cannot be overstated. However, there has been insufficient research on how to develop effective restoration strategies at minimal cost. This paper addresses this gap by studying how optimizing the spatiotemporal distribution of human activities through local and boundary controls can reduce the level of desertification in vegetation pattern structures, thereby facilitating the recovery of arid land vegetation. The results indicate that vegetation restoration depends on the proportion and number of human activity areas, with a trade-off between them. Furthermore, consistent conclusions were obtained on circular regions, demonstrating the robustness of the approach to boundary shapes. This paper aims to offer new insights into the restoration of arid land vegetation and the prevention of catastrophic ecosystem changes from the perspective of optimal control.

Observer-Based Asynchronous Boundary Stabilization for Stochastic Markovian Reaction-Diffusion Neural Networks.

This work investigates the observer-based asynchronous boundary stabilization for a kind of stochastic Markovian reaction-diffusion neural networks with exogenous disturbances. Specifically, parameter uncertainties are considered in the drift item. First, a hidden Markov model is introduced that guarantees the observer modes run asynchronously with the system modes. It should be noted that the asynchronous observer constructed in this work only uses the boundary measurement information. Then a nonfragile asynchronous observer-based boundary controller is designed. Taking advantage of inequality techniques and stochastic analysis method, sufficient criterion is provided to satisfy input-to-state exponentially mean-square stability, and the asynchronous boundary observer/controller gains are further derived. As a special case, the synchronous observer-based boundary stabilization is also obtained. Finally, a numerical example is exploited to manifest the validity of the established results.

Preface

From September 27th to 29th, 2024, Harbin, China welcomed an academic feast - the 2024 2nd International Conference on Applied Statistics, Modeling and Advanced Algorithms (ASMA 2024). The conference gathers together about 100 famous scholars, experts, engineers and technicians as well as technology developers at home and abroad to discuss the latest research results and development trends in the fields of applied statistics, modeling and advanced algorithms. The ASMA conference series holds a significant place in the academic calendar, serving as a platform for sharing cutting-edge research, fostering collaborations, and driving innovation. The inaugural ASMA conference sets a high benchmark, and it is our pleasure to continue this tradition with ASMA 2024, which aims to build upon the success of its predecessor by exploring new frontiers and deepening our understanding of these intricate and ever-evolving disciplines. As an important event for domestic and international academics, ASMA 2024 attracts the attention of researchers and scholars from around the world. Experts and scholars from international institutions such as King’s College London (UK), and University of Jaen (Spain) gathered with scholars from China’s Xiamen University, Guangdong University of Science and Technology, Harbin University of Science and Technology, etc. to share their scientific research results and practical experiences in the domains of applied statistics, modeling and advanced algorithms and their relevant disciplines. In addition, many elites from the business community also participated in the conference enthusiastically, bringing a wealth of practical cases and cutting-edge thinking to the conference. The main agenda of ASMA 2024 is meticulously designed to encompass a broad spectrum of topics, including but not limited to reinforcement learning and fuzzy model-based control, output feedback adaptive boundary control for distributed parameter systems, quadratic estimation for discrete non-Gaussian systems, and secure state estimation using encryption and decryption strategies. These themes are meticulously chosen to reflect the current trends and future directions in the fields of applied statistics, modeling, and advanced algorithms. The conference also features a diverse array of presentations, including keynote speeches, oral presentations, poster sessions, and panel discussions. During these presentations, the participants actively interacted with the speakers and each other, colliding with a lot of new sparks of ideas. In addition to the wonderful academic reports and discussions, this conference also includes a number of high-quality academic contributions, forming a rich collection of papers. These papers cover a wide range of aspects, including statistical mechanics, data mining, partial differential equations, modeling simulation input, numerical analysis, natural computing, etc., with both theoretical discussions and practical analyses, fully demonstrating the latest research dynamics and academic level in these fields. Finally, we would like to express our special thanks to all the participants for their hard work and contributions. It is their active participation and in-depth exchanges that made this conference a complete success. Meanwhile, we would also like to acknowledge the conference organizers for their careful preparations and thoughtful arrangements, which provides a good platform for academic exchanges and cooperation among the participants. The Committee of ASMA 2024 List of Committee Member is available in this Pdf.

The role of annealing and grain boundary controls on the mechanical properties of limestones and marbles

Chemical and mechanical processes are coupled in many geological and geochemical environments. Reactive processes anneal defects and restructure grain boundaries, modifying their elastic properties, levels of internal friction, wave propagation rates and fracture behaviors. The nature of these changes is, however, contingent on the initial state of the rock. In this study, impulse excitation was used to measure changes in mechanical properties as a function of dry and steam heating time at 300 °C for three carbonate rocks: Carrara marble, Carthage marble (Burlington Limestone), and Texas Cream limestone (Edwards limestone), with initial porosities of about 1 %, 3 %, and 27 %, respectively. Frequency-dependent phenomena along with mineral recrystallization were observed. This was coupled with small-angle X-ray and neutron scattering analysis to determine the relationship between changes in bulk mechanical and microstructural properties. An observed decrease in both the Young's and shear moduli in the experimental limestones as a function of heating time reflects and quantifies a reduction in the stiffness of the rock due to annealing. The internal friction of the samples first increases then decreases with reaction time, reflecting defect annealing, but this was balanced against grain boundary dissolution apparently driven by condensation of steam in the confined grain-boundary environment. This suggests an increase in the boiling point under confinement leading to dissolution, increased porosity and widening of the grain boundaries. In addition, comparison of small-angle X-ray and neutron scattering results suggests that it is inappropriate to assume that pores are empty for quantitative analysis of typical small-angle scattering samples.

Pressure Analysis of Vertical-Wells with the Hydraulic Fracturing Assisted Water Injection in Low-Permeability Hydrogen and Carbon Reservoirs.

Enhancing the energy of hydrogen and carbon reservoirs is crucial for the extraction of these resources. Currently, the conventional water-flooding technology faces challenges in replenishing the energy of hydrogen and carbon reservoirs due to the low injection rates caused by their low-permeability properties. To address this, hydraulic fracturing-assisted water injection technology has been employed to enhance the energy of these reservoirs. However, there has been a lack of research on pressure analysis for vertical wells using this technology. Existing studies on pressure analysis are not applicable to this scenario due to the unique behavior of dynamic fracture propagation. In this article, we present a pressure analysis model for vertical wells with hydraulic fracturing-assisted water injection in low-permeability hydrogen and carbon reservoirs, considering dynamic fracture propagation. The model examines the effects of key parameters on the pressure and fluid flow fronts, and it is applied to field wells for validation. Our findings include the following: the typical pressure response curve for vertical wells with hydraulic fracturing-assisted water injection in low-permeability hydrogen and carbon reservoirs can be divided into six stages: dynamic fracture propagation region, linear flow region in hydrogen and carbon reservoirs, bilinear flow region, radial flow region, transition flow region, and boundary control flow region. The production rate affects the pressure and pressure derivatives in the later stages of the process. However, reservoir permeability influences all flow regions, causing the pressure and pressure derivative curves to shift left with increasing permeability. Increases in both the injection rate and production rate result in a rise in the position of fluid fronts. The impact of permeability on fluid fronts is more significant in the early stages than in later stages. This work is of great significance for the development of low-permeability hydrogen and carbon reservoirs, providing a deeper understanding of the pressure dynamics involved in hydraulic fracturing-assisted water injection.

Hierarchical Stackelberg Control for a Two-Stroke Linear System in Population Dynamics

We study a unique hierarchical control problem for a two-stoke linear system, adjoint to an age and space dependent population dynamics problem. Using Stackelberg's method, we introduce two levels of control: a boundary control to achieve optimal flow regulation and a distributed control for null controllability. Our approach employs Carleman inequalities to address non-homogeneous Dirichlet boundary conditions, leading to new insights in controlling invasive species populations. These results highlight the applicability of hierarchical controls in ecological systems, providing a robust framework for future studies in control theory and population dynamics.

Strong Stability for a Viscoelastic Transmission Problem under a Nonlocal Boundary Control

The purpose of this paper is to consider a transmission problem of a viscoelastic wave with nonlocal boundary control. It should be noted that the present paper is based on the previous C. G. Gal and M. Warma works, together with H. Atoui and A. Benaissa. Namely, they focused on a transmission problem consisting of a semilinear parabolic equation in a general non-smooth setting with an emphasis on rough interfaces and nonlinear dynamic (possibly, nonlocal) boundary conditions along the interface, where a transmission problem in the presence of a boundary control condition of a nonlocal type was investigated in these papers. Owing to the semigroup theory, we prove the question of well-posedness. For the very rare cases, we combined between the frequency domain approach and the Borichev–Tomilov theorem to establish strong stability results.

Adaptive vibration control for stabilisation of the Euler–Bernoulli beam with an unknown payload

In this paper, an adaptive boundary controller is designed to solve the boundary control problem of Euler–Bernoulli beams with an unknown payload. Therefore, a boundary controller with an adaptive law is designed to compensate for the parameter uncertainty of the system. Partial Differential Equations (PDEs) are used to describe the Euler–Bernoulli beam system. The well-posedness of the system under the action of an adaptive boundary controller is proved by using the linear operator semigroup method. Meanwhile, the asymptotic stability of the closed-loop system is derived from the extended Krasovskii–LaSalle invariance principle. The effectiveness and superiority of the proposed method are illustrated by simulation in comparison with the existing results.

Adaptive boundary control for a friction hoisting system during the loading process

This paper aims at the rope dynamic tension fluctuation (DTF) control in the friction hoisting system (FHS) during the loading process. The exact dynamic modelling of the tail and head ropes connected to the cage is considered. A disturbance observer is proposed to track the actual impact disturbance. The actuator acts at the friction wheel to pretension the system. The use of an adaptive neural network allows for the handling of system uncertainty. An appropriate control law is developed to stabilize the cage and suppress the rope DTF in FHS during the loading process. Numerical simulations and theoretical analysis are presented to prove the feasibility and effectiveness of the proposed control law. Numerical analysis results show that the head rope dynamic displacement fluctuation (DDF) and DTF amplitudes can be suppressed to at least 1/125 of their initial fluctuation amplitudes under the proposed control law.

Boundary Value and Control Problems for the Stationary Magnetic Hydrodynamic Equations of Heat Conducting Fluid with Variable Coefficients

Boundary Value and Control Problems for the Stationary Magnetic Hydrodynamic Equations of Heat Conducting Fluid with Variable Coefficients

Социокультурный подход к изучению феномена детства

The article substantiates the relevance of the appeal to the study of the phenomenon of childhood, analyzes the negative consequences of the collapse of the country in the 1990s, and notes a positive trend in the activities of the state in the socio-cultural sphere of modern Russia. The methodological multidimensional nature of the study of the phenomenon of modern childhood is considered and the need for its use within the framework of a sociocultural approach is argued, while the features of childhood culture and its content are revealed. The authors present examples of the implementation of the results of scientific research on the phenomenon of childhood in the educational activities of universities in the country, as well as a brief description of the educational course “Culture of Childhood”, its constituent elements, and some approaches to teaching methods. An integral element in the study of the course “Culture of Childhood” is conducting training sessions and boundary control using interactive forms and teaching methods, performing creative tasks that contribute to the development of socio-cultural technologies, and the accumulation of a “creative portfolio”. The article substantiates the idea of the need for further study of childhood and the use of research results for implementation in social practice and in the training of specialists in the socio-cultural sphere. Conclusions are drawn that the study of the world of childhood in different human societies is multi- and interdisciplinary in modern science. The peculiarity of the socio-cultural approach to the study of the phenomenon of childhood is the systematization and synthesis of existing and new knowledge about modern childhood and the integration of research results into social practice, there has been a tendency to form a new aspect in the field of socio–cultural study of the phenomenon of childhood – educational.

Sliding mode control to stabilization of coupled time fractional parabolic PDEs subject to disturbances

AbstractIn this article, the stabilization of coupled time fractional parabolic partial differential equations subject to external disturbances is investigated. By using sliding mode control method and backstepping approach, a boundary state feedback controller is designed to reject the matched disturbance and achieve the Mittag‐Leffler input‐to‐state stability of closed‐loop system. The existence of the generalized solution to the closed‐loop system is proven by Galerkin approximation scheme. Simulations are presented to illustrate the validity of our theoretical results.