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Restoration involves the recovery and repair of environments because environmental damage is not always irreversible, and communities are not infinitely resilient to such harm. When restoration projects are applied to nature, either directly or indirectly these may take the form of ecological, forestry or hydrological restoration, for example. In the current scenario of global climate change and increasing intensity of disturbances the importance of restoration in all types of ecosystems in order to adapt to the new conditions (so called prestoration) is evident. Whatever the objective of the restoration initiative, there is a lack of consensus as regards common indicators to evaluate the success or failure of the different initiatives implemented. In this study, we have carried out an extensive meta-analysis review of scientific papers aiming to evaluate the outcomes of restoration projects. We have done a review and selected 95 studies implemented in Europe. We explored the main pre-restoration land cover in which restoration initiatives have been implemented, the main causes of degradation, the objective of the restoration action and the indicators selected to analyze the success or failure of the action. We identified a total of 84 indicators in the analyzed papers and compared with the ones proposed for forest in the recent Nature Restoration Law. The analysis revealed five indicators commonly used for the evaluation of restoration initiatives (abundance, coverage, density, Ellenberg indicator, and richness), even where the initial objective has not yet been achieved. Our findings underscore both the benefits and challenges associated with a specific set of harmonized indicators for evaluating the success or failure of restoration initiatives. [ABSTRACT FROM AUTHOR]

The robust control problem of permanent magnet synchronous motor (PMSM) is discussed in this paper. Both iron loss and voltage saturation are considered in the analysis process in order to close to the actual projects. A controller design method, which is called the Hamiltonian-based method, is proposed for the PMSM control system. The responses of each current component and speed are analyzed when load torque disturbance exists. The proposed controller enables the closed-loop system to have robust performance criteria without violating saturation. It is worth noting that a more general truncation-inequality technique is used to deal with saturation, which reduces the conservatism of parameter selection. In addition, the corresponding results are given for two special cases. When there is no saturation and no load torque disturbance, the system is asymptotically stable at the equilibrium point. Simulation results and experimental study show that the proposed method has good load disturbance suppression ability and can ensure the robust performance of the PMSM in EV driving systems. [ABSTRACT FROM AUTHOR]

The path tracking performance of autonomous vehicles is degraded by common disturbances, especially those that affect the safety of autonomous vehicles (AVs) in obstacle avoidance conditions. To improve autonomous vehicle tracking performances and their computational efficiency when subjected to common disturbances, this paper proposes a tube linear model predictive controller (MPC) framework for autonomous vehicles. A bicycle vehicle dynamics model is developed and employed in the tube MPC control design in the proposed framework. A robust invariant set is calculated with an efficient linear programming (LP) method, and it is used to guarantee that the constraints are satisfied under common disturbance conditions. The results show that the computational cost of robust positively invariant sets that are constructed by the LP method is much less than that obtained by the traditional method. In addition, all the trajectories of the tube linear MPC successfully avoided obstacles when under disturbance conditions, but only about 80% of the trajectories obtained with the traditional MPC successfully avoided obstacles under disturbance conditions. The proposed framework is effective. [ABSTRACT FROM AUTHOR]

The primary objective of this paper was to compare the nutrient content (N, Ca, S, K, P, Mg) of bilberry biomass, both aboveground and underground, growing in different habitats along the altitudinal gradient. The research was conducted in protected areas of the High Tatras National Park (Slovakia). Two different habitats subjected to study, namely spruce forest stands affected by disturbances (D - disturbed forest stands) and stands unaffected by disturbances (U - undisturbed forest stands), were located at different altitudes: 1 100 m a.s.l., 1 250 m a.s.l., and 1 400 m a.s.l. We found significant differences in the soil nutrient content along the altitudinal gradient. The highest content of nutrients was detected mostly at the highest altitudes in both habitats. The minimum reached 0.01 g·kg-1 (phosphorus), while the maximum was 8.33 g·kg-1 (nitrogen). In the case of the bilberry biomass, we found statistically non-significant differences in the content of nutrients among the altitudes within both habitats (D vs. U). The principal component analysis (PCA) showed that the aboveground biomass of bilberry had a significantly higher nutrient content compared to the underground biomass. Nutrient content in aboveground and underground biomass ranged from 1.00 g·kg-1 (phosphorus) to 13.49 g·kg-1 (nitrogen) and from 0.38 g·kg-1 (magnesium) to 7.55 g·kg-1 (nitrogen), respectively. The biological absorption coefficient (element content in dry biomass/element content in soil) reached the highest values mostly at the lowest altitude for both aboveground and underground biomass. [ABSTRACT FROM AUTHOR]

This paper investigates the one-bit function perturbation (OBFP) impact on the robust set stability of Boolean networks with disturbances (DBNs). Firstly, the dynamics of these networks are converted into the algebraic forms utilizing the semi-tensor product (STP) method. Secondly, OBFP's impact on the robust set stability of DBNs is divided into two situations. Then, by constructing a state set and defining an index vector, several necessary and sufficient conditions to guarantee that a DBN under OBFP can stay robust set stable unchanged are provided. Finally, a biological example is proposed to demonstrate the effectiveness of the obtained theoretical results. [ABSTRACT FROM AUTHOR]

This paper studies the stable degree for profile of networked evolutionary games (NEGs) with disturbances by the semi-tensor product of matrices. Firstly, the algebraic formulation of an NEG with disturbances is established. Secondly, on the basis of algebraic formulation, some concepts about stable profile with disturbances are proposed, including strong k-degree stable and weak k-degree stable, and the corresponding criteria to detect the stable degree are presented. Thirdly, two algorithms for designing controls are given to make the stable profile achieves strong k-degree stable or weak k-degree stable. Finally, an example is given to illustrate the validity of the results. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of sliding mode control for a class of hybrid switched systems with matching disturbances. Firstly, a sliding mode surface is designed, and the corresponding sliding mode equation for the switched system is derived. Then, we analyzed the stability of the sliding mode equation using the Lyapunov function and average dwell time. Moreover, a sliding mode control law is designed with the approach law method to drive the system state to a bounded sliding mode region and then maintain it there subsequently. Finally, an illustrative example is given to demonstrate the efficiency of the approach. [ABSTRACT FROM AUTHOR]

The current article gives a new approach that is efficient for the design of a low-order H∞ controller over a finite time interval. The system under consideration is a linear discrete time system affected by norm bounded disturbances. The proposed method has the advantage that takes into account both robustness aspects and desired closed-loop characteristics, reducing the number of variables in Linear Matrix Inequalities (LMIs). Thus, reduced order H∞ controller parameters are given to guarantee a finite time H∞ bound (FTB-H∞) for a closed-loop system. The method of the finite time stability, that is proven in this paper by the Lyapunov theory, can be applied to a wide range of process models. Numerical examples demonstrating the effectiveness of the results developed are presented at the end of this paper. [ABSTRACT FROM AUTHOR]

This paper investigates the stabilization of the generalized Lotka–Volterra (GLV) biological model, which is affected by the asymptotically unbounded external disturbances, and presents some new results. Firstly, two stabilizers are proposed for the nominal GLV system. Then, some appropriate filters are designed and applied to asymptotically track the corresponding disturbances. Based on these filters, two disturbance-estimator (DE)-based controllers are presented to cancel the corresponding disturbances. Compared to the existing results, the advantage of this paper is in handling the asymptotically unbounded external disturbances effectively. Finally, the correctness and effectiveness of the proposed results are verified by computer simulation. [ABSTRACT FROM AUTHOR]

Functional observers are the major alternative to many practical estimation problems where full-order observers cannot be used. This paper introduces a generalized approach to design H∞ functional observers for a class of Lipschitz nonlinear systems with multiple time delays. Moreover, the considered system extends from previously published work in that it presents nonlinearity, multiple delay and external disturbance. Their main findings come from the development of a generalized augmented Lyapunov function that uses both the extended reciprocal convex combination and the Wirtinger inequality. The stability of the observer is therefore guaranteed by an LMI optimization problem. Finally, the steps of the design procedure were condensed and proffered for the two numerical examples to test the recommended design approach. [ABSTRACT FROM AUTHOR]

Sensors and actuators frequently encounter unexpected deviations from their optimal operating conditions, making their reliability an essential topic in many electric motor drives. In this paper, a comparison of structured residual synthesis methods for actuator and sensor additive fault detection and isolation (FDI) in a permanent magnet (PM) DC motor, applying two different approaches to the design of primary residuals, is presented. The first method involves a standard approach and is based on system transfer matrix synthesis. The second, more convenient approach involves the synthesis of primary residuals based on the analysis of subsystems that describe the observed system. Both methods are applicable for linear and time-invariant (LTI) systems but were successfully applied to a laboratory system that shows nonlinear behavior, time-variant properties, and is affected by a constant disturbance, thanks to the proposed technique of residual translation with the previous design of internal residuals. With the proposed method, all important performance characteristics of the residual generators such as fault sensitivity, reaction speed, and robustness are achieved. The technique can be applied to all mechatronic systems in general, whose behavior can be with satisfactory accuracy described by an LTI model. Given the transfer functions and state-space model of the system in the presence of faults in the Z domain with reduced order, presented technique is computationally efficient for embedded systems. Also, in addition to fault detection and isolation, the system can identify faults by analyzing fault sensitivities, nominal faults, and stationary residual values, making it superior for most FDI applications. A real-time experiment performed on a laboratory setup, which consists of a DC motor, an amplifier designed in the form of a linear electronic circuit, and a Compact RIO 9075 real-time processor is used to develop the FDI system, to generate residuals and confirm advantages of the proposed FDI technique. [ABSTRACT FROM AUTHOR]

Central European countries are strategic wood exporters in the European and international wood trade. In the context of wood exporters, Czechia, Germany, Poland, Slovenia, and Austria are the important countries providing the development and stability of the forestry and wood sector. The share of these countries' exports in total EU exports represents more than 52% of the volume of wood exported over 5 years. After the Netherlands, the five mentioned countries recorded the highest increase in roundwood production of all EU and EFTA countries in the years 2000–2022 (from 46% (AT)–126% (CZ)), and the European average is 26%. The last decade has been characterised by a significant destabilisation of the Central European timber market as a result of natural disturbances linked to climate change, which also threatens the long-term competitiveness and preservation of this sector in the economic systems of national economies. The article provides an analytical insight into the historical development of natural calamities and their macroeconomic consequences in Central European countries. The data forecast an unfavourable development of the timber market in Europe caused by the ongoing calamity situation, the pricing policy of the timber trade, the oversaturation of the market with lower-quality calamity timber, insufficient processing capacities for primary processing of wood and its use in secondary processing, and, last but not least, the limited stock of timber in the coming years in selected Central European countries (due to an extreme increase in harvesting plans within the last 5 years, with consequences that will be felt in the coming decade). For the continued economic function of forests and the availability of wood supply for future generations, the current evolution of calamities in forest ecosystems is critical, and long-term strategic measures based on empirical data are necessary. The information presented in this paper can serve as a tool for the objectification of strategic decisions in the development of forestry policies in selected countries. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel free chattering robust nonlinear sliding mode control based on the Lyapunov theory for underactuated two-wheels mobile robots. The salient features of the proposed control method are as: (1) it considers the full dynamics of the system, disturbances, and uncertainties; (2) it has not considered the small signal model of the system that leads to the large signal instability; and (3) the proposed underactuated control results in less costs, least chattering, easy implementation, and no stability issues. The proposed nonlinear controller is designed based on Lyapunov and Lassalle theory. Moreover, we have shown that the proposed controller is robust against disturbances and uncertainties. [ABSTRACT FROM AUTHOR]

This article presents a new control approach for the optimal and reliable operation of the microbial fuel cell, as one of the most important sources of renewable energy. Considering several adverse effects on the performance of the microbial fuel cell, including the effects of uncertainty, disturbance, and of course, taking into account the nonlinear dynamics and the necessary conditions for the stable and optimal operation of the fuel cell, this paper presents a novel robust hybrid approach to its performance management. The innovative approach by using adaptive and sliding mode techniques, by focusing on providing a theoretical solution and not changing the structure of the fuel cell, reduces and suppresses the effects of disturbance and uncertainty of the model, and by guaranteeing the stable and reliable operation of the microbial fuel cell in the Lyapunov concept, provides rapid regulation of system states. The results of simulation and comparison in the MATLAB environment show the efficiency and optimal performance of the fuel cell system under the planned control method from the perspective of improving the transient and permanent response. [ABSTRACT FROM AUTHOR]

Feedforward control can be considered as the most well-known control approach to deal with measurable disturbances. It started to be used almost 100 years ago, and since then it is being used in most industrial processes. It is a very simple technique that has been used typically as a complement to PID control, although it can be combined with any feedback controller. The feedforward control design has traditionally been performed assuming perfect cancellation of the disturbance signal, and when this solution was not possible because of non-realisable problems, static design solutions were usually implemented. In the last decade, this issue has been researched and analysed, and new designs for feedforward control have appeared to face these problems. As a result, a set of new simple tuning rules have been obtained providing considerable improvements in the control system performance. This paper presents a summary of these contributions and a short history of feedforward control. [ABSTRACT FROM AUTHOR]

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This paper considers the global tracking control problem for a class of nonlinear systems. Compared with the existing results, one significant distinction of this work is that it allows the high-order powers, zero dynamics, time-delay and external disturbances. By constructing a new Lyapunov–Krasovskii (L–K) functional and using the modified adding a power integrator method, we successfully design a non-smooth tracking controller which guarantees that all the signals of the closed-loop system are bounded. The tracking error can be adjusted small enough using the designed parameters. As a practical application, in the simulation, the single-link robot system is studied to show the validness of the strategy. [ABSTRACT FROM AUTHOR]

In this paper, a hybrid transmission system equipped with a speed regulating differential mechanism (SRDM) is proposed for grid-connected wind turbines (WTs) to generate constant-frequency electricity. However, the transmission system is subject to pulsating torque from disturbances in the power grid. Coupled with parameter uncertainties, the speed control accuracy of SRDM and the system stability can hardly be warranted by conventional adaptive or robust controllers. Aiming at the proposed WT, this paper presents a discontinuous projection-based adaptive robust backstepping controller (ARBC) with an extended state observer (ESO) for high-accuracy speed control of permanent magnet synchronous motor in SRDM. The designed control approach, whose global robustness is guaranteed by a feedback robust law, can effectively handle both parametric uncertainties and external disturbances together without using the large nonlinear feedback gain and violating any constraints during the transient period. Then, the desired tracking performances of ARBC with ESO are verified through comparative experiments in a built platform of the WT with SRDM. Comparative experimental results show that SRDM equipped with the integrated control method can accurately regulate the power frequency to constant under operating conditions of parametric uncertainties, varying wind speeds, subsynchronous resonance, and sudden load fluctuation in the power grid. [ABSTRACT FROM AUTHOR]

The present paper investigates a fixed-time tracking control with fractional-order dynamics for a quadrotor subjected to external disturbances. After giving the formulation problem of a quadrotor system with six subsystems like a second-order system, a fractional-order sliding manifold is then designed to achieve a fixed-time convergence of the state variables. In order to cope with the upper bound of the disturbances, a switching fixed-time controller is added to the equivalent control law. Based on the switching law, fixed-time stability is ensured. All analysis and stability are proved using the Lyapunov approach. Finally, the higher performance of the proposed controller fixed-time fractional-order sliding mode control (FTFOSMC) is successfully compared to the two existing techniques through numerical simulations. [ABSTRACT FROM AUTHOR]

This paper represents a new generation of adaptive disturbance rejection control (ADRC) which is more robust against disturbances than conventional ADRC. The non-derivability of the fal function employed in the traditional ADRC has negative impacts on its operation, so alternate functions will be used which are derivable at all segments. In this regard, odd hyperbolic and trigonometric functions were employed. The performance of the proposed structure was investigated to control the doubly fed induction generator (DFIG) speed. To enhance the efficiency of the suggested ADRC, fractional-order calculations and fuzzy logic were utilized simultaneously. The results in MATLAB platform indicate that: 1) With constant wind speed and changing reference speed, using new fal functions in fuzzy fractional-order ADRC (FFOADRC) has improved the performance compared to the PI regulator and FFOADRC with default fal function. 2) During wind speed variations and using new fal functions, the DFIG speed reaches the final steady amount as over damping, while this condition is critical damping when using FFOADRC with default fal function. 3) During network voltage reduction, using new FFOADRCs leads to fewer oscillations in the stator flux, DC-bus voltage, and DFIG speed, which shows their better performance than PI regulator and traditional ADRC. [ABSTRACT FROM AUTHOR]

The event‐triggered state estimation problem with the aid of machine learning for nonlinear systems is considered in this paper. First, we develop a recurrent neural network (RNN) model to predict the nonlinear systems. Second, we design a discrete‐time dynamic event‐triggered mechanism (ETM) and a state observer based on this ETM for the prediction model. This discrete‐time dynamic event‐triggered state observer significantly reduces the utilization of communication resources. Third, we establish a sufficient condition to ensure that the state observer can robustly estimate the state vector of the RNN model. Finally, we provide an illustrative example to verify the merit of the obtained results. [ABSTRACT FROM AUTHOR]

This paper mainly investigates the bipartite fixed-time consensus problem with or without disturbances of multi-agent systems. Firstly, we propose a novel bipartite fixed-time consensus algorithm based on event-triggered mechanism. Secondly, we use Lyapunov stability theory to guarantee that all agents states can reach a consensus of bipartite fixed-time. Then, the fixed-time stability theory is used to estimate the settling time, which shows that the settling time has nothing to do with the initial state of all agents. Furthermore, it is proved that under this consensus protocol, no zeno behavior is occurred. Finally, two numerical examples are finally presented to illustrate the theoretical analysis correctness. [ABSTRACT FROM AUTHOR]

This paper aims to report on the South East European Regional Council of CIGRECIGRE (SEERC) activities related to resilience of electrical power networks. Based on the results of an organized SEERC workshop focusing on resilience of network issues during which member countries of the region presented their own experiences in resilience planning, the paper presents new measures recently put into force in SEERC countries as well as endeavours to immediate technical modifications of assets imposed by lessons learned during past emergency events. The first part of the paper presents the SEERC region of CIGRECIGRE, the energy data, the size of the T&D electrical network, the emission of the CO2 equivalent due to the potential impact on future transition planning of the energy sector, and consequences to the resilience of electric networks. The second part of the paper deals with resilience experiences of different countries in the region after large weather disasters as well as with threatening events caused by cyber attacks. The last part of the paper analyses innovative measures for strengthening resilience in selected systems as it was presented at the SEERC workshop in Rome (2018). The paper also deals with the assessment of loading limits of selected essential network components aiming to reduce system vulnerability during emergencies, hence increasing its resilience. The majority of the experienced emergencies were produced by harsh weather conditions during winter. There were many cases of Overhead Line (OHL) failures which triggered detailed analyses to determine the encountered mechanical loads. A suitable refurbishing of critical parts of OHL has been done respecting the new standards for the construction of electrical overhead lines in Europe. Aiming to allow the expedited restoring of OHL operating capability in emergencies, the introduction of using emergency (modular) towers was selected and successfully implemented. Intensive support to asset management was provided, e.g., maintenance optimization, state-of-the-art approaches, condition monitoring of HV equipment, life cycle assessment, evaluation of assets etc. [ABSTRACT FROM AUTHOR]

Advances in production planning and control in recent decades have focused on increasing the sophistication of the planning function. For good reasons, these advances have led to the centralisation of the planning function in production. However, the sophistication of the planning function should be in balance with monitoring and control of the plan. Monitoring and control are by their nature decentralised, beginning on the shop floor, and, therefore, the desire for greater sophistication in monitoring and control leads to renewed interest in decentralised and localised approaches. This paper demonstrates the possibility of using intelligent products for decentralised monitoring and control. Intelligent products are aware of their local context and can negotiate with local manufacturing resources. As such, local solutions to problems can be proposed directly when problems occur. With the advancement of the 'Internet of Things', such a scenario is likely to become feasible in the near future. The paper demonstrates the viability of such an approach through a simulation study, in which robustness is included as an additional measure of performance. The results of the simulations are encouraging. [ABSTRACT FROM AUTHOR]

There are growing concerns about the effect of solar flares on the ionosphere, mainly due to possible deterioration or damage to our communication and navigation satellite systems. On 3 July 2021, and 28 October 2021, there were solar flares (SFs) classified as X1.59 and X1.0, respectively. These two SFs were the only ones of X‐class that occurred during the last low solar activity (LSA:2018–2021). Data from magnetometers and Global Positioning System (GPS)—Total Electron Content (TEC) are used to investigate the spatial‐temporal electrodynamics of the ionosphere from pole‐to‐pole in the American sector. Employing ∆H and vertical TEC, along with the ROT (rate of change of VTEC) parameter. Rapidly ∆H disturbances closely follow the X‐ray variation and the ∆H valleys and peaks are well‐synchronized during the SFs, indicating that they are linked. Major disturbances in the ∆H are noticed in the mid‐low‐equatorial latitudes. However, minor disturbances were seen at high latitudes. Also, |ROT| is a good indicator of the electron density changes during the SFs, especially when the X‐ray intensity rises to the peak. Plain Language Summary: There are growing concerns about the effect of solar flares on the ionosphere, mainly due to possible deterioration or damage to our communication and navigation satellite systems. This kind of space weather event known as solar flare, releases energy in the form of radiation in the entire electromagnetic spectrum. However, the UV, EUV, and X‐ray radiation burst penetrates deeper into the Earth's atmosphere and is absorbed in the D and E regions (lower ionosphere) and F‐region. In this investigation the ionospheric disturbances are investigated, from pole‐to‐pole, using a magnetometer and GPS‐TEC networks. Key Points: The primary objective of this paper is to investigate the ionospheric response to solar flares across the entire latitudinal rangeThe ∆H exhibited synchronized peaks and valleys, during SF. The ROT is the most effective parameter to study electron density disturbancesThe methodology employed in this study involves the calculation and analysis of ∆H, VTEC, and ROT (Rate of TEC change) [ABSTRACT FROM AUTHOR]

This paper presents a robust optimal control approach for the wheel mobile robot system, which considers the effects of external disturbances, uncertainties, and wheel slipping. The proposed method utilizes an adaptive dynamic programming (ADP) technique in conjunction with a disturbance observer. Initially, the system's state space model is formulated through the utilization of kinematic and dynamic models. Subsequently, the ADP method is employed to establish an online adaptive optimal controller, which solely relies on a single neural network for the purpose of function approximation. The utilization of the disturbance observer in conjunction with the compensation controller serves to alleviate the effects of disturbances. The Lyapunov theorem establishes the stability of the complete closed-loop system and the convergence of the weights of the neural network. The proposed approach has been shown to be effective through simulation under the effect of the disturbances and the change of the desired trajectory. [ABSTRACT FROM AUTHOR]

Dairy systems, which are the main pillars of rural livelihoods in north-eastern Europe encounter ecological, economic, and political changes in their operating environments which threaten their capacity to provide dairy supply. As uncertainty increases, there is a need to increase understanding and identify concrete tools to help food system actors manage resilience. We defined 'dairy systems' as a social-ecological system in which milk supply is the primary function, and humans and ecosystems endogenous factors. We conducted a qualitative empirical study to develop, enrich, and validate a theoretical framework, acknowledging social, economic, and ecological perspectives affecting the resilience. This paper identifies critical changes affecting the systems and key determinants of dairy system resilience, especially means actors can manage, in two socially and ecologically contrasting regions, Finland and Russia. The data consist of 26 qualitative in-depth interviews conducted in Finland and the surroundings of St Petersburg in the Leningrad Oblast. The critical changes confronting dairy system actors in both regions were especially related to prices and economics, policies, and epidemics. In Finland, possible cuts to agricultural subsidies, as well as an increasing workload, were perceived as a significant threat, whereas risks related to investors and resource adequacy were highlighted in Leningrad Oblast. Despite the socioeconomic distinctions between the countries, the determinants were similar and included ecological, economic, and social issues. However, the form of farm ownership proved decisive: for family farms in Finland, social well-being determinants were more important than economic ones; for investor-owned businesses in Leningrad Oblast, the opposite was the case. The results can be used by dairy systems actors, as well as administrators and policymakers, as a tool for understanding, assessing, and managing resilience. [ABSTRACT FROM AUTHOR]

This paper presents a predefined-time fractional-order control for a quadrotor system subjected to perturbations. First, a fractional-order sliding manifold is proposed to ensure a predefined-time convergence of the tracking error. Second, a fractional-order switching-type predefined-time controller is proposed to achieve robustness against external disturbances. The predefined stability/convergence are proved using Lyapunov functions. The proposed method is validated using an adequate scenario and compared to other controllers to show the feasibility and superiority of the proposed one. [ABSTRACT FROM AUTHOR]

This paper addresses the H ∞ filters design problem for delayed nonlinear systems subject to L 2 − norm disturbances via Takagi-Sugeno (T-S) fuzzy approach with interval time-varying delay. An appropriate Lyapunov-Krasovskii functional (LKF) is established in the framework of augmented system. Then, on the basis of the free-weighting matrix technique and convex method, some improved integral inequality are employed and combined with a decoupling approach without ignoring any useful terms. Therefore, less conservative delay dependent conditions are obtained in terms of linear matrix inequality (LMIs), wish can be solved by using the Matlab LMI toolbox, to achieve the desired H ∞ performance. Finally, three numerical examples are given to demonstrate the advantages and the effectiveness of the obtained results, compared with some previous method in the literature. [ABSTRACT FROM AUTHOR]

Summary: This paper studies the consensus problem for one‐sided Lipschitz (OSL) multiagent systems (MASs) affected by bounded disturbances via dynamic edge event‐triggered mechanism (DEETM). Due to disturbances and OSL dynamics in MASs, the event‐triggered consensus problem of which is quite more difficult than those of linear or Lipschitz nonlinear networks without disturbances in the previous works. In order to cope with this problem, a novel consensus method is developed based on DEETM and adaptive technique, which contains adaptive gains in both controller and DEETM. Firstly, smooth adaptive items in controller are designed to significantly compensate unknown disturbances, which can guarantee asymptotic consensus. Moreover, DEETM can effectively reduce the communication cost among neighboring agents, which does not cause Zeno behavior. It is worth noticing that the developed method is fully distributed, which relies on neither global information of the communication topology nor the upper and lower bounds of disturbances. Finally, a simulation example is given to demonstrate the effectiveness of theoretical results. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of a temperature shock on a small spacecraft with symmetrically arranged flexible elements. A two-dimensional thermoelasticity problem is posed. The disturbing effect of temperature shock on a small spacecraft has been determined. The assessment of the main disturbing factors arising from the temperature shock of flexible elements of a small spacecraft was carried out. Approximate dependences were obtained for the components of the displacement vector of the flexible element points. Numerical simulation was carried out for the symmetric scheme of the small spacecraft with two and four flexible elements. The dependence of the inertia force on temperature shock for the simulated small spacecraft at various initial deflections of the flexible element was constructed. Conclusions were drawn about the significance of the temperature shock influence on the dynamics of a small spacecraft. The results obtained were compared with the results of other studies and can be used in solving problems of remote sensing of the Earth and the implementation of gravity-sensitive processes on board small spacecraft. [ABSTRACT FROM AUTHOR]

Restoration involves the recovery and repair of environments because environmental damage is not always irreversible, and communities are not infinitely resilient to such harm. When restoration projects are applied to nature, either directly or indirectly these may take the form of ecological, forestry or hydrological restoration, for example. In the current scenario of global climate change and increasing intensity of disturbances the importance of restoration in all types of ecosystems in order to adapt to the new conditions (so called prestoration) is evident. Whatever the objective of the restoration initiative, there is a lack of consensus as regards common indicators to evaluate the success or failure of the different initiatives implemented. In this study, we have carried out an extensive meta-analysis review of scientific papers aiming to evaluate the outcomes of restoration projects. We have done a review and selected 95 studies implemented in Europe. We explored the main pre-restoration land cover in which restoration initiatives have been implemented, the main causes of degradation, the objective of the restoration action and the indicators selected to analyze the success or failure of the action. We identified a total of 84 indicators in the analyzed papers and compared with the ones proposed for forest in the recent Nature Restoration Law. The analysis revealed five indicators commonly used for the evaluation of restoration initiatives (abundance, coverage, density, Ellenberg indicator, and richness), even where the initial objective has not yet been achieved. Our findings underscore both the benefits and challenges associated with a specific set of harmonized indicators for evaluating the success or failure of restoration initiatives.

This paper presents an adaptive approach for controlling the nonlinear vehicle suspension system in the presence of unknown delay and limited disturbance. All three factors present in the quarter vehicle suspension model including uncertainty, disturbance and input delay are limited but unknown. This paper dealings a nonlinear model to describe more accurately the behaviour of the suspension and the controller design. To prove stability in the Lyapunov concept, the proposed control method is a combination of backstepping and adaptive approaches. The results of the simulation confirm better active suspension performance regardless of the unknown time delay, disturbances and uncertainty in the nonlinear model. [ABSTRACT FROM AUTHOR]

In this work, we consider the problem of simultaneously estimating the system states and unknown inputs in a linear sampled-data system, whose dynamics is influenced by external disturbances and uncertainties. Hardware limitations prevent an estimation scheme for a sampled-data system from achieving finite-time convergence, which is a typical property of existing sliding mode observers for dynamical continuous-time systems, because the sampling period is finite. Due to the sampling process, an approximate implementation of such an observer, designed for a continuous-time system, may not retain the desired performance in the sampled-data context. In this paper, we present an observer which takes advantage of the quasi-sliding motion concept to simultaneously estimate the state variables and the unknown input signals in a sampled-data context. A theoretical study is conducted to formally justify the convergence properties of the observer whilst simulation results are provided to show the efficiency of the proposed scheme. [ABSTRACT FROM AUTHOR]