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Naturalistic plantings, such as meadow‐style plantings, can improve the quality of urban green spaces through aesthetic, biodiversity and low maintenance features. Species selection for, and maintenance of naturalistic plantings are key to their success. While herbaceous and grassy meadows can be mowed, naturalistic plantings with woody plants require more intense maintenance to remove biomass and promote resprouting. We aim to understand woody plant responses to diverse disturbance regimes to potentially inform the selection and management of woody species in urban plantings. We conducted a quantitative systematic literature review of 72 papers and investigated what main external (climate, disturbance regime) and internal (buds, life stage, storage reserves) factors influence the resprouting response of woody plants. We found resprouting literature is geographically widespread for woody plants, but studies are skewed towards Temperate climates in USA and Australia, with a focus on high severity and high frequency fire disturbance. Resprouting response was mostly defined as a continuous response to disturbance dependent on disturbance regime, climate and plant traits. Maintenance and management of naturalistic woody plantings, through hard pruning techniques such as coppicing, may be informed by analogous high severity and high frequency disturbance studies. However, the literature on woody plant resprouting has several knowledge gaps for lower severity and lower frequency disturbance regimes and in more arid climates. Future research should evaluate the response of naturalistic woody plantings to disturbance in specific urban contexts. [ABSTRACT FROM AUTHOR]

Throughout South-East Asia, droughts associated with ENSO (El Niño Southern Oscillation) events have resulted in large-scale fires affecting millions of hectares of rain forest. However, the long-term impacts of these fires on the rain forest faunas are only poorly understood. Our aim was to study the recovery of rain forest butterfly assemblages following the 1997–98 ENSO event, which resulted in the largest-scale fires in the recorded history of the region. A 420-km2 area in the Balikpapan-Samarinda region of East Kalimantan, Indonesian Borneo. Four landscapes were assessed after the 1997–98 ENSO event, including one landscape that was assessed prior to the event. Comparisons of species richness, species composition and guild abundance were made among landscapes and years. The relative importance of environment, geographical distance between sampling sites, and time between sampling years was quantified during the succession phase using a variance partitioning technique. The fires dramatically altered the butterfly community and resulted in a major decline in observed species richness within the landscape surveyed prior to the ENSO event. Following fires in 1998, butterfly assemblages in all landscapes were dominated by large-winged generalist species. During 1999 and 2000, assemblages became increasingly dominated by smaller specialist species. Species endemic to Borneo that were present before fires were absent in 2000, despite intensive sampling over enhanced spatial and environmental scales. Community similarity was significantly dependent upon local environmental variables, geographical distance between sampling sites, and time between sampling years. Together, these explained over 52% of the observed variation in samples. The importance of geographical distance between sampling sites indicates that recovery was dependent upon colonization from proximate habitats. Despite an apparent trend of return to pre-ENSO community structure, low species richness throughout the survey area indicates that full recovery had not taken place by 2000. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of speed cruise control in high-speed trains, which are modeled as large-scale systems with each car considered as an independent subsystem. Decoupled H ∞ controllers are employed for each car. To address parameter uncertainties and time-varying delays, a comprehensive analysis of the robustness and time-delay stability of the large-scale system was conducted, which led to the design of decoupled controllers. Simulations and comparative analyses were conducted to validate the correctness of the control algorithm and demonstrate the feasibility of controlling high-speed trains as large-scale time-delay systems. This study has yielded theoretical results in large-scale system control, successfully applying results to high-speed train control. The idea and method offer new perspectives and lay the foundation for addressing more complex issues in high-speed trains. [ABSTRACT FROM AUTHOR]

Moderate severity disturbances, which only kill a subset of canopy trees (e.g., via insects, pathogens, and windthrow), are increasingly widespread in North America, and can alter forest structure and production. Whether the net primary production (NPP) of forest stands differing in pre-disturbance site quality and composition respond similarly to moderate severity disturbance, however, is unknown, but critical to understanding the disturbance response dynamics of patchy landscapes. We experimentally disturbed three, 2-ha stands varying in pre-disturbance primary production and community composition, temporarily reducing live stand basal area by 38% to 66% through the stem girdling of all mature early successional aspen (Populus tremuloides Michx. and Populus grandidentata Michx.) and birch (Betula papyrifera Marshall). Disturbance significantly altered stand-scale physical and biological structure and prompted a similar decade-long pattern of wood NPP decline and recovery. All stands exhibited an initial reduction in wood NPP, followed by a recovery period and eventual return to pre-disturbance levels within eight years, with the most productive stand exhibiting an increase in primary production following recovery. Following wood NPP recovery, more biologically diverse forest canopies with higher leaf area indexes intercepted more light, and, consequently, had higher rates of wood NPP.We conclude that, despite substantial pre-disturbance differences in productivity and community composition, relative wood NPP recovery patterns can be similar, though long-term post-recovery primary production may trend higher in more productive and compositionally diverse stands. We suggest that improved mechanistic understanding of different forest ecosystems' responses to disturbances remains critical to informing management decisions across diverse landscape mosaics. [ABSTRACT FROM AUTHOR]

In a nonlinear control system, hysteresis exists usually as common characteristics. In addition, external output disturbances like modelling error, machine friction and so on also occur frequently. Both of them are considered to cause instability and unsatisfactory performance. In this paper, a practical nonlinear control system design is proposed so as to achieve the simultaneous control of input hysteresis and output disturbance. The system is based on RCF (right coprime factorization theory). Additionally, the proposed design has been applied to a soft robotic finger system and the results of simulations and practical experiments are exhibited, which show the effectiveness of the proposed system. [ABSTRACT FROM AUTHOR]

Since the integration of electronic devices and intelligent electronic devices into the power grid, power quality (PQ) has consistently remained a significant concern for system operators and experts. Maintaining high standards of power quality is crucial to preventing malfunctions and faults in electric assets and connected loads. Recently, PQ studies have shifted their focus to a specific frequency range, previously not considered problematic—the supraharmonic 2 kHz to 150 kHz range. This range is not populated by easily recognizable harmonic components of the 50 Hz to 60 Hz mains fundamental, but by a combination of intentional emissions, switching non-linearities and byproducts, and various types of resonances. This paper aims to provide a detailed analysis of the impact of supraharmonics (SHs) on power network operation and assets, focusing on the most relevant documented negative effects, namely power loss and the heating of grid elements, aging of dielectric materials, failure of medium voltage (MV) cable terminations, and interference with equipment and power line communication (PLC) technology in particular. Under some shareable assumptions, limits are derived and compared to existing ones for harmonic phenomena, providing a clear identification of the primary issues associated with supraharmonics and suggestions for the standardization process. Strictly related is the problem of grid monitoring and assessment of SH distortion, discussing the suitability of normative requirements for instrument transformers (ITs) with a specific focus on their accuracy. [ABSTRACT FROM AUTHOR]

The permanent magnet electrodynamic suspension (PMEDS) owns the promising application prospect, due to its simple structure, low cost and reliable load capacity. However, the underdamping of the PMEDS system is still a challenge in engineering applications of transportation. This paper proposes a passive damping method and its implementation structure to improve the underdamping characteristics. This method utilizes the inherent magnetic leakage of on-board magnets technically. The principle of passive damping and its implementation structure is introduced in detail. And the kinetic models of ordinary and improved structure are established based on the topology graph. Besides, the magnetic field and the electromagnetic force involved in the kinetic models are analyzed, and the numerical analysis method of the drag force is verified by the high-speed test rig. Furthermore, the performance of passive damping is verified by finite element method (FEM) and the time-domain response analysis. The results show that the improved damping structure can effectively suppress vibration and improve the dynamic stability of the PMEDS system. It is beneficial to the engineering application of the PMEDS in the future. [ABSTRACT FROM AUTHOR]

This paper considers a construction procedure of a satellite reference angular motion in the vicinity of an unstable gravitational equilibrium position. The satellite is stabilized on the reference trajectory by the magnetic coils. The problem is solved in several stages. An optimization problem to be solved by the particle swarm optimization method is formulated at each stage. Cost functions are based on the linearized model analysis. The main stage is the construction of a special reference motion, which provides the minimum control torque projection on the geomagnetic induction vector. Optimal geomagnetic field dipole approximation for a given time interval is considered to reduce tracking errors. The paper compares combinations of different cost functions in terms of the terminal attitude accuracy in the presence of perturbations. [ABSTRACT FROM AUTHOR]

As coral reefs endure increasing levels of disturbance, understanding recovery patterns of reef‐building hard corals is paramount to assessing the sustainability of these ecosystems. At local scales, coral recovery slows down; however, it's unclear how this trend propagates across spatial scales due to the inherent complexity of coral dynamics. In this paper, we aimed to learn about fine scale heterogeneity of coral dynamics and explore implications for assessing coral recovery at larger spatial scales. We developed a spatio‐temporal statistical model to estimate long‐term trajectories of three types of corals and predict their recovery patterns at unobserved locations within a reef. Then, model predictions were used to derive metrics that capture the interplay between coral growth and decline from disturbance(s) across time, space and growth morphology. This model is developed in the context of a substantive case study at Heron Reef using a high spatio‐temporal resolution dataset. Our results revealed that successful coral community recoveries took place in different habitats of Heron Reef and associated with various reasons. Branching corals recovered in the southern slope, due to fast growth in locations that were previously abundant. Plate corals flourished in the northern slope due to fast growth, despite a large decline and low baseline cover. They also recovered in the southern slope but in this case there was both a low decline and baseline cover. At Heron Reef, the recovery of coral communities followed specific conditions that were acting at a fine scale in a complex and heterogeneous way within habitat. This implies that capturing the variability of fine‐scale coral dynamics is an important first step to detect accurate signals of coral recovery at larger spatial scales. The approach proposes here can be further extend to the scale of a reef and beyond enabling assessment of recovery patterns representative at management scales. [ABSTRACT FROM AUTHOR]

This paper is concerned with the attitude tracking problem of quadrotor unmanned aerial vehicles (UAVs) with respect to endogenous uncertainties, exogenous disturbances and actuator failures. Two different control methods are proposed to solve this problem. First, an adaptive extended state observer (AESO)-based control framework is devised to tackle the difficulties caused by model uncertainties and external disturbances. A fault-tolerant control method is proposed to cope with the occurrence of actuator failure, which is modeled as a constant loss of effectiveness. Another method employs AESOs to compensate for lumped disturbances, which include endogenous uncertainties, exogenous disturbances and actuator failures. Then, the error can exponentially converge to a bounded set. Finally, simulations are performed to ensure the feasibility of the designed technique. [ABSTRACT FROM AUTHOR]

Copyright of Romanian Journal of Information Technology & Automatic Control / Revista Română de Informatică și Automatică is the property of National Institute for Research & Development in Informatics - ICI Bucharest and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Disturbances caused as a result of the misalignment and axial motion of the journal affect the characteristics of the rotor-bearing system. This paper aims to propose an algorithm for the theoretical analysis of a rotor-bearing system that considers these disturbances. A theoretical model for a journal bearing considering disturbances is given. The dynamic equations for a rigid rotor-bearing system are introduced. A detailed algorithm that can simultaneously solve the rotor-dynamic equations and the Reynolds equation is proposed. The static performance, such as the bearing attitude angle and the fluid film pressure, are given, and dynamic characteristics such as the nonlinear dynamic responses and the axial orbits of a rigid rotor-bearing system are presented. The hydrodynamic effect of the bearing is enhanced by the axial disturbance. Disturbances in the circumferential and radial directions lead to variations in the fluid film thickness distribution in the axial direction and the offset of the fluid film pressure distribution in the axial direction. When these disturbances work together, the variation trend is more obvious and affects the capacity and dynamic characteristics of the bearing. When the L/D value of the bearing increases, the clearance between the journal and the bearing decreases rapidly. When the value reaches a certain limit, contact and collision might occur. The theoretical analysis method and the algorithm proposed for a rotor-bearing system considering several disturbances could enhance the design level for a bearing and rotor-bearing system. [ABSTRACT FROM AUTHOR]

Globally, protected areas such as national parks are mainly established to protect the rapidly declining populations of conservation concern wildlife species, as well as ecologically and economically important areas. In addition, more recently, establishing and maintaining protected areas has become an essential part of the global response of governments to combat climate change and its impacts. However, most of these protected areas are facing an unprecedented rate of biodiversity and ecosystem degradation due to human-induced actions. Mitigation of threats and their impacts on biodiversity in these protected areas is very critical. But limited information, needed to develop strategies for mitigation of the ever-growing threats, is available on the biophysical resources and threats to them. This paper presents for the first time, detailed information on the Exceptional Resource Values (ERVs), Principal Ecosystem Components (PECs; or conservation targets), and human-induced threats in the Kafta-Sheraro National Park (KSNP). Standard ecological and social science methods were used to collect and analyze the data. Overall, 14 key ERVs were identified in the park, including several conservation concerns and/or flagship mammal species (e.g. African Elephant (Loxodonta africana)), biome-restricted and migratory bird species (e.g., Demoiselle crane (Anthropoides virgo)), three distinct habitat types, and a hydrological system. Six PECs that were assumed to represent the whole ecosystem components of the park were identified in KSNP: the three habitat types, hydrological system, Elephant, and Roan antelope (Hippotragus equines). The top human-induced threats to these PECs appeared to be fire, cultivation, grazing, settlement, poaching, and mining. In general, KSNP contains outstanding biodiversity and other natural resources that could play a vital role in the socio-economic development of local and regional communities. To ensure the long-term persistence of the ERVs and PECs and the appropriate functioning of the park ecosystems the development and implementation of threat mitigation strategies are required. [ABSTRACT FROM AUTHOR]

This paper schemes a new nonlinear method for controlling and suppressing of chaos instability in the PMSM. First, a nonlinear model of PMSM is considered that is able to describe the dynamic behaviour of the PMSM in different functional conditions, including the occurrence of chaos. As an integral part of most physical systems, disturbance with an unknown upper limit is considered in the design of the control scheme. Parametric uncertainty is also included in the PMSM system model and a new control technique is presented based on robust adaptive and sliding mode approaches to prevent chaos. In the proposed method, adaptive technique is used to estimate the upper bound of uncertain terms, disturbances and nonlinear terms, and the robust sliding mode scheme is designed to stabilize the closed-loop PMSM system in contradiction of chaos. Using comparisons, the efficiency of the proposed method is shown in different working conditions. [ABSTRACT FROM AUTHOR]

Abstract: Extreme events are of interest worldwide given their potential for substantial impacts on social, ecological, and technical systems. Many climate‐related extreme events are increasing in frequency and/or magnitude due to anthropogenic climate change, and there is increased potential for impacts due to the location of urbanization and the expansion of urban centers and infrastructures. Many disciplines are engaged in research and management of these events. However, a lack of coherence exists in what constitutes and defines an extreme event across these fields, which impedes our ability to holistically understand and manage these events. Here, we review 10 years of academic literature and use text analysis to elucidate how six major disciplines—climatology, earth sciences, ecology, engineering, hydrology, and social sciences—define and communicate extreme events. Our results highlight critical disciplinary differences in the language used to communicate extreme events. Additionally, we found a wide range in definitions and thresholds, with more than half of examined papers not providing an explicit definition, and disagreement over whether impacts are included in the definition. We urge distinction between extreme events and their impacts, so that we can better assess when responses to extreme events have actually enhanced resilience. Additionally, we suggest that all researchers and managers of extreme events be more explicit in their definition of such events as well as be more cognizant of how they are communicating extreme events. We believe clearer and more consistent definitions and communication can support transdisciplinary understanding and management of extreme events. [ABSTRACT FROM AUTHOR]

Human‐caused global change produces biotic and abiotic conditions that increase the uncertainty and risk of failure of restoration efforts. A focus of managing for resiliency, that is, the ability of the system to respond to disturbance, has the potential to reduce this uncertainty and risk. However, identifying what drives resiliency might depend on how one measures it. An example of a system where identifying how the drivers of different aspects of resiliency can inform restoration under climate change is the northern coast of California, where kelp experienced a decline in coverage of over 95% due to the combination of an intense marine heat wave and the functional extinction of the primary predator of the kelp‐grazing purple sea urchin, the sunflower sea star. Although restoration efforts focused on urchin removal and kelp reintroduction in this system are ongoing, the question of how to increase the resiliency of this system to future marine heat waves remains open. In this paper, we introduce a dynamical model that describes a tritrophic food chain of kelp, purple urchins, and a purple urchin predator such as the sunflower sea star. We run a global sensitivity analysis of three different resiliency metrics (recovery likelihood, recovery rate, and resistance to disturbance) of the kelp forest to identify their ecological drivers. We find that each metric depends the most on a unique set of drivers: Recovery likelihood depends the most on live and drift kelp production, recovery rate depends the most on urchin production and feedbacks that determine urchin grazing on live kelp, and resistance depends the most on feedbacks that determine predator consumption of urchins. Therefore, an understanding of the potential role of predator reintroduction or recovery in kelp systems relies on a comprehensive approach to measuring resiliency. [ABSTRACT FROM AUTHOR]

This paper presents a novel leader-follower consensus control for a particular class of nonlinear multi-agent mechanical systems in the presence of control input constraints and external disturbances which includes robot system dynamics with a wide range of potential applications in industry. In this case, one of the agents is selected as the leader to direct the other agents in such a way that the whole system can reach consensus within certain prescribed performance transient bounds. Due to the presence of disturbances in most practical systems, the effect of limited disturbance in the consensus control method has been investigated, and actuator saturation is included in the design process. A terminal sliding mode control method has been adapted to ensure the stability of the overall system and fast finite-time leader-follower consensus control. The simulation results of the multi-agent nonlinear robot system in MATLAB environment, in different scenarios with simultaneous consideration of actuator saturation and external disturbance, will show the efficiency of the proposed control method. [ABSTRACT FROM AUTHOR]

Featured Application: The control strategy proposed to this paper can be applied to the joint position and velocity tracking down industrial robots (series or parallel manipulators). Theoretically, it is suitable for general second-order nonlinear systems, such as inverted pendulum control, motor coupling control, dual manipulator cooperative control, etc. Background: As a control strategy of industrial robots, sliding mode control has the advantages of fast response and simple physical implementation, but it still has the problems of chattering and low tracking accuracy caused by chattering. This paper proposes a new sliding mode control strategy for the application of industrial robot control, which effectively solves these problems. Methods: In this paper, a deep deterministic policy gradient–nonlinear nonsingular fast terminal sliding mode control (DDPG–NNFTSMC) strategy is proposed for industrial robot control. In order to improve the tracking control accuracy and anti-interference ability, DDPG is used to approach the uncertainties of the system in real time, which ensures the robustness of the system in various uncertain environments. Lyapunov function is used to prove the stability and finite time convergence of the system. Compared with the nonsingular terminal sliding mode control (NTSMC), the time to reach the equilibrium point is shorter. With the help of MATLAB/Simulink, the tracking accuracy and control effects are compared with traditional terminal sliding mode control (TSMC), NTSMC and radial basis function–sliding mode control (RBF–SMC), the results showed that it had the advantages of nonsingularity, finite time convergence, small tracking error. The motion accuracy and anti-interference ability of the uncertain manipulator system was further improved, and the chattering problem of the system in the motion process is effectively eliminated. [ABSTRACT FROM AUTHOR]

This paper researches the fixed-time leader-following consensus problem for nonlinear multi-agent systems (MASs) affected by unknown disturbances under the jointly connected graph. In order to achieve control goal, this paper designs a fixed-time consensus protocol, which can offset the unknown disturbances and the nonlinear item under the jointly connected graph, simultaneously. In this paper, the states of multiple followers can converge to the state of the leader within a fixed time regardless of the initial conditions rather than just converging to a small neighborhood near the leader state. Finally, a simulation example is given to illustrate the theoretical result. [ABSTRACT FROM AUTHOR]

Phase change materials (PCM) have been widely used in Thermal Energy Storage (TES) Systems. Considering the energy efficiency and the use of domestic hot water, the melting temperature range of phase change materials is considered to be optimal in the range of 50–60 °C. The most commonly used is sodium acetate trihydrate-based phase change material, which has the advantages of high latent heat and low price, but its high supercooling, low thermal conductivity, and phase separation affect its application. Therefore, this paper used sodium acetate trihydrate, disodium hydrogen phosphate dodecahydrate (DSP), and expanded graphite (EG) as raw materials to prepare composite phase change materials (CPCM) and used physical disturbance to further improve their properties. Firstly, their thermophysical properties were investigated by the step cooling curve method, differential scanning calorimetry (DSC), and x-ray diffraction (XRD). Secondly, in order to further evaluate the effect of physical disturbance on CPCM crystallization, further experimental studies were carried out by adjusting the rotor mass and rotational speed. The experimental results showed that when 1.5 wt.% DSP, 1.5 wt.% EG and physical perturbation work together, the CPCM phase transition temperature is 56.7 °C, and the latent heat is as high as 258.98 kJ/kg. At this time, its thermal conductivity increased from 0.62 w/m·k to 1.1625 w/m·k, and its subcooling degree decreased from above 20 °C to less than 0.5 °C, and no phase separation occurred. The greater the disturbance momentum (the greater the rotor mass or the greater the rotational speed), the shorter the induction time, which is more conducive to the crystallization of CPCM. The results obtained in this paper are instructive for the preparation of efficient new CPCMs. [ABSTRACT FROM AUTHOR]

Copyright of Radio Electronics, Computer Science, Control is the property of Zaporizhzhia National Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problems of parameter disturbance and coupling disturbance in a vehicle drive axle loading test-bed, this paper used the adaptive backstepping sliding mode control (ABSMC) strategy to design the controller for the speed and torque system. The effectiveness of the controller has been verified by simulation and an experiment. The results show that the equivalent moment of inertia is increased by 5 times, and the step response overshoot of the speed system is 4.1%. By adding a random disturbance, the sinusoidal tracking errors of the speed and torque systems are 0.05 r/min and 0.09Nm, respectively. [ABSTRACT FROM AUTHOR]

This paper investigates the stabilization of nonlinear systems with external disturbances, which are both bounded and unbounded. Firstly, the stabilization problem of the nominal nonlinear system is realized, and the corresponding stabilization controllers are designed. Then, three suitable filters are proposed and applied to asymptotically estimate the corresponding disturbances, and the disturbance estimators are presented and used to exactly eliminate the corresponding disturbances. Then, the disturbance estimator (DE)-based controllers are proposed to stabilize such nonlinear systems. It should be pointed out the unbounded disturbances are exactly estimated by suitable filters, which has advantages over the existing results. Finally, two illustrative examples, which have certain symmetrical properties, are taken, and the related numerical simulations are carried out to verify the effectiveness and correctness of the proposed results. [ABSTRACT FROM AUTHOR]

Distributed second-order finite-time adaptive containment and bipartite containment control are investigated for multi-agent system with disturbance and nonlinear function under undirected graph in this paper. Firstly, two controllers are designed to achieve finite-time adaptive containment and bipartite containment control, which both based on terminal sliding mode. Then, desired finite-time containment and bipartite containment protocols are proposed and settling time can be estimated. It is proved that settling time of finite-time containment is associated to initial state. Feasibility of theory is proved by simulation experiments. [ABSTRACT FROM AUTHOR]

This paper proposes an Adaptive Neuro Linear Quadratic Regulator (ANLQR) controller for Buck converter operating under harmful disturbances. Considering the real‐time condition of a converter with regular variations, Neural Network is adopted to improve and tune the gain of the LQR strategy with an adaptive mechanism. This strategy assumes the system as a Gray‐box process without the need for the exact mathematical model of the system which can result in lower computational burden, faster dynamics, and ease of implementation. ANLQR control strategy is a suitable alternative considering its significant robustness against different disturbances, particularly noise. It should be mentioned that the number of neurons is limited to 2 and 4 in each layer to decrease the computational burden with lower complexity. The advantages of this ANLQR method is justified for various operating situations through experimental and simulation outcomes. Moreover, LQR and PSO‐PID controllers are designed and compared with the presented strategy to carry on a comparison with the proposed method. Furthermore, this approach provides better outcomes with faster dynamics and better frequency adaption in the real‐time environments. [ABSTRACT FROM AUTHOR]

Additionally, we observed that I Cassiopea i individuals spent less time in vegetated seagrass habitat (~1 day) and stayed longer on bare (artificial) bioturbation mounds (>10 days), suggesting that the individuals are mostly passing through habitats with high seagrass cover selecting open spaces to settle (corresponding to findings of Niggl & Wild, [8]). Keywords: bioturbation; Cassiopea; colonization; competition; disturbance; exotic seagrass; habitat preference; Halophila stipulacea; landscape modification; patch dynamics EN bioturbation Cassiopea colonization competition disturbance exotic seagrass habitat preference Halophila stipulacea landscape modification patch dynamics 1 5 5 04/05/23 20230401 NES 230401 In tropical ecosystems, autotroph organisms are continuously competing for space, with some plant species benefiting from disturbances such as fire, grazing, or bioturbation that clear habitats (Pulsford et al., [11]). In this paper, we report evidence of a novel ecological interaction in a tropical seagrass ecosystem between two autotroph species, the invasive seagrass I H. stipulacea i and the native upside-down jellyfish I Cassiopea i spp. We hypothesize that the arrival of the invasive I H. stipulacea i is likely to shift patch dynamics in the seagrass ecosystem and, thereby, niche competition between seagrasses and I Cassiopea i . [Extracted from the article]

Ecological restoration has recognized explicitly the recovery of ecosystem functions. The emphasis on ecosystem functions in restoration efforts can be defined as functional restoration. Functional restoration, i.e., rehabilitation of ecosystem functions, is particularly applicable to highly degraded landscapes such as desertified areas, where restoration to the original state is impossible. This review paper produced a general conceptual model of the fundamental processes that regulate ecosystem functions in water-limited ecosystems. The Israeli Negev Desert was used as a case study to test the model results in the field. We developed general guiding principles for functional restoration of degraded landscapes that integrate functional restoration methods and include four successive steps: (1) identifying the fundamental processes that regulate ecosystem functions in alternative states; (2) detecting drivers leading to degraded states; (3) functional restoration: changing the state of the degraded landscape; and (4) monitoring the impact of the restoration effort and assessing its success in terms of ecosystem services. Our case study, the Negev, provided us with insights on how to reverse desertification in water-limited systems by restoring source–sink networks as a subset of functional restoration. The four suggested steps of functional restoration are essential for ecosystem recovery in the Anthropocene. [ABSTRACT FROM AUTHOR]

A power quality measurement system is introduced in this paper. While sampling with a high rate, it provides mains frequency synchronous voltage and current data in the form of 215 samples per cycle using a linear interpolation unit. The interpolation output sampling rate is provided by a mains frequency estimation unit, which conducts phase locking on the voltage measurements and additionally outputs the synchrophasor, frequency, and the rate of change of frequency. This algorithm is checked in simulations against the current standards, while discussing a phenomenon that is not yet taken into account by these standards: low-frequency interharmonic disturbances such as ripple control signals, which occur frequently in today’s power grids. To desensitize the system toward these, compromises must be taken when it comes to standard compliance under transient conditions. Thereafter, first measurements with an evaluation system are analyzed to get a first impression of the system response to real signals. [ABSTRACT FROM AUTHOR]

Social forestry (SF) has long been implemented in production and protected forests in Indonesia. SF is considered to be a win–win solution for occupied and cultivated forest areas. The aim of this paper was to review the implementation of social forestry in Indonesia and its strengths and challenges. The secondary purpose was to synthesize the lessons learned and recommendations for the government about designing SF that can integrate the objective of forest biodiversity conservation and the social welfare of the surrounding communities. The study used a systematic literature review (SLR) of international and national peer-reviewed articles. The results of the study indicate that SF is intended to achieve benefits in three main areas: social, economic, and ecological. However, the review found that the ecological aspects of biodiversity conservation often receive less attention compared to the social and economic goals. A strong point of SF implementation is increasing community access to forest land use, while a challenge that must be resolved is that including communities in forest management can result in fragmentation and changes to animal habitats; thus, there is the potential for population decline and extinction. This study advises policymakers to pay more attention to ecological functions to ensure forest sustainability in SF development. [ABSTRACT FROM AUTHOR]

In this paper, a new method is presented for synchronization between two fractional order delayed chaotic systems, while there is uncertainty on the models and external disturbances enter the systems at the same time. The considered delay in the fractional order system is unspecified and varied with time, and of course it is present in different forms in master and slave systems. External disturbances enter the master–slave systems in a finite manner, albeit with an undetermined upper bound, and uncertainty is present in the nonlinear functions of chaotic systems. The goal of synchronizing a particular class of master–slave chaotic systems is achieved through a combination of adaptive and sliding mode techniques. The sliding mode method has been used to cover the effects of uncertainties and delay functions, and an adaptive method has been applied to ensure the stability of the proposed synchronization technique, disturbance upper bound estimation and overcoming the effects of delay variability. A practical example of the innovative method is simulated in MATLAB environment and the obtained results confirm the optimal efficiency of the proposed synchronization method. [ABSTRACT FROM AUTHOR]

This paper investigates secure control of Networked Inverted Pendulum Visual Servo Systems (NIPVSSs) based on Active Disturbance Rejection Control (ADRC). Firstly, considering the network- and image-induced delays in conjuction with computational errors caused by image processing and image attacks, the model of NIPVSSs is established. Secondly, the limitations of the traditional Single-Input-Single-Output (SISO) ADRC used in NIPVSSs with disturbance are revealed. The limitations are that the ESO used in the traditional SISO ADRC brings large steady-state error, and the NLSEF used in the traditional SISO ADRC can achieve stable control of pendulum angle, but cannot achieve stable control of cart position. Thirdly, a new Single-Input-Multi-Output (SIMO) ADRC method is proposed for NIPVSSs with disturbance. In the new SIMO ADRC method, the new ESO is designed by introducing additional first and second derivatives of error to reduce the steady-state error. In addition, the new NLSEF is developed by taking both the calculated cart position and pendulum angle as inputs to achieve dual stable control of pendulum angle and cart position. Finally, combined with the designed ADRC parameter-tuning strategy, the results from simulation and real-world experiments confirm the effectiveness and feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the fundamental requirements for a cloud-based scheduling service for manufacturing, notably manufacturer priority to scheduling service, resolution of schedule conflict, and error-proof data entry. A flow chart of an inference-based system for manufacturing scheduling is proposed and a prototype was designed using semantic web technologies. An adapted version of the Muth and Thompson 10 × 10 scheduling problem (MT10) was used as a case study and two manufacturing companies represented our use cases. Using Microsoft Project, levelled manufacturer operation plans were generated. Semantic rules were proposed for constraints calculation, scheduling and verification. Pellet semantic reasoner was used to apply those rules onto the case study. The results include two main findings. First, our system effectively detected conflicts when subjected to four types of disturbances. Secondly, suggestions of conflict resolutions were effective when implemented albeit they were not efficient. Consequently, our two hypotheses were accepted which gave merit for future works intended to develop scheduling as a web service. Future works will include three phases: (1) migration of our system to a graph database server, (2) a multi-agent system to automate conflict resolution and data entry, and (3) an optimisation mechanism for manufacturer prioritisation to scheduling services. [ABSTRACT FROM AUTHOR]

In this paper, the stabilization for Schrödinger equation subject to internal damping and boundary disturbance at the control end is investigated. Due to its immeasurability, the nonlinear observer system is designed to obtain the state information, and the existence of weak solution and its convergence for the nonlinear observer system are proved. The feedback control is realized by the backstepping transformation. In addition, the adaptive disturbance rejection control is applied to estimate the disturbance. According to the observer and disturbance estimation, the feedback control is finally designed to stabilize the system asymptotically. [ABSTRACT FROM AUTHOR]

This paper is concerned with the partial anti-synchronization of the 4D financial hyper-chaotic system with periodically external disturbance. Firstly, the existence of the partial anti-synchronization problem for the nominal 4D financial system is proven. Then, a suitable filter is presented, by which the periodically external disturbance is asymptotically estimated. Moreover, two disturbance estimator (DE)-based controllers are designed to realize the partial anti-synchronization problem of such a system. Finally, numerical simulation verifies the effectiveness and correctness of the proposed results. [ABSTRACT FROM AUTHOR]

In real-world applications, hydraulic pressure control performance is influenced by model uncertainties, the control bandwidths of valves and pumps, and deviations from the linear working region. To overcome the aforementioned obstacles, a novel reference governor for disturbance observer (DOB)-based load pressure control is proposed in this paper for a dual-actuator-driven electrohydraulic cylinder. First, a control-oriented model for load pressure control was developed. On the basis of this, a nonlinear DOB-based feedback controller, as well as a mid-range control architecture for the variable displacement pump and proportional valve, was fabricated so that the performance degradation caused by the pump's slow responses and imprecise system parameters is suppressed. Specifically, this controller is augmented by a novel smooth reference governor, which modifies the load pressure command in the pressure transition periods to guarantee that the actuator's constraints are not violated. Another merit of the novel reference governor is that it ensures a smooth trajectory transition, and therefore, unmodeled high-frequency plant dynamics will not be invoked. Case studies were carried out to verify the effectiveness of the proposed control approach. The study results show that the approach can significantly enhance the hydraulic system's pressure tracking performance. [ABSTRACT FROM AUTHOR]

This paper investigates the robust stability and stabilization of networked evolutionary games (NEGs) with time delays. First, a mathematical model is presented to describe the dynamics of NEG with time-varying delays and disturbances. Second, an auxiliary system is constructed using the semi-tensor product of matrices and a dimension augmenting technique. Then, a verification condition of robust stability is derived. Third, in order to stabilize NEG to the Nash equilibrium, the robust stability problem is transformed into the robust stabilization problem. Moreover, an algorithm is proposed to design the stabilization controller. Finally, the validity of the results is verified by an example. [ABSTRACT FROM AUTHOR]

This paper proposed a robust deadbeat predictive current control (PCC) of the permanent magnet linear synchronous machine (PMLSM) with an extended state modeling (ESM) based Kalman filter (KF) for both the state and disturbance estimation. First, the disturbance dynamics of the PMLSM electrical subsystem is analyzed in detail and then the ESM is constructed as considering the disturbance as a higher order integrator motivated by the main idea of the extended state observer. Second, the KF for the current prediction with reduced noises and the disturbance estimation due to the parameter variation is designed combining with the ESM. Furtherly, the robust PCC is introduced with the ESM-based KF. Finally, the parameter tuning for the ESM-based KF is discussed with the discrete simulation and then the experimental results are given under the single current closed loop and the double cascade position-current loop with linear-varying parameter. Both the simulation and experimental results verify the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]