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• The 2019 wildfires raised global concern about wildfires, their causes and effects. • Fire has distinct roles in fire-prone and fire-sensitive ecosystems. • In fire-prone ecosystems, we need to overcome taboos regarding the use of fire. • In fire-sensitive systems, strategies to reduce fires are urgent. • Climate-change and increasing human impact change fire regimes. In the recent past, wildfires have received much attention both by science and by the media, especially in relation to deforestation, degradation and climate change and when affecting fire-sensitive ecosystems. On the other hand, fire is a natural process in many ecosystems, in particular those to be considered fire-dependent; here, maintaining natural fire regimes is important to maintain biodiversity and ecosystem services. In many regions of the world we are still in the need for a better understanding of fire effects on plant populations, communities and ecosystems. For instance, responses of individuals and populations to heat and fire can differ among distinct fire-prone ecosystems, and community level responses often vary depending on historical disturbance regimes or the fire regime as such. Effects on ecosystem processes, e.g. on carbon cycles, can vary greatly in scale and are even more difficult to predict. This adds up to uncertainties regarding appropriate fire management strategies, both in fire-prone and fire-sensitive ecosystems. Here, we introduce a set of opinion papers on fires in Brazil and a forthcoming Virtual Special Issue of Flora – Morphology, Distribution, Functional Ecology of Plants on "Fire and vegetation", with contributions expected from a broad range of topics related to fire, plants, and vegetation. This special issue will contribute to the development not only of more knowledge on fire effects on plants and vegetation, but also to advances in fire management policies in different ecosystems around the world. The main issue, after all, is to go beyond simple classification of fires as 'good' or 'bad', but rather to develop strategies to deal with changing fire regimes and their effects in a dynamic world increasingly modified by human actions. [ABSTRACT FROM AUTHOR]

For a stochastic PID feedback control system, the uncertainty of the working environment often leads to the unsatisfied performance of the system, which does not meet the profit requirements. The working environment generally includes external disturbance and measurement noise, etc. Gaussian distributed measurement noise and disturbances are widely considered while non-Gaussian distributed measurement noise and disturbances are rarely considered. In this paper, the performance degradation of Gaussian/non-Gaussian disturbances and measurement noise on a stochastic PID feedback system is considered and analyzed. An efficient method, dynamic data reconciliation (DDR) is developed to filter measurement noise and disturbances and improve the performance of the stochastic PID feedback control system. By utilizing model-based and measured information, DDR avoids time delays in output estimation. With the detailed theoretical analysis and simulation verification, the effectiveness of the proposed DDR technology on the stochastic PID feedback control system is verified. Compared with conventional exponential filters, DDR can achieve better control performance. The proposed DDR is also used for the control system of the DC–AC​ converter. The improved effect of DDR on the output quality is demonstrated by the results. • Effect of Gaussian/non-Gaussian disturbances on control performances is analyzed. • Dynamic data reconciliation (DDR) is developed to enhance control performances. • DDR corrects measurements with Gaussian/non-Gaussian disturbances and noises. • SISO, MIMO, and DC–AC converter control systems are used for verification. [ABSTRACT FROM AUTHOR]

This paper investigates the multistability on a class of delayed neural networks with monotonically nondecreasing linear activation function. For n state neurons with 2 m + 1 piecewise linear activation function, we prove the neural networks have (2 m + 1) n equilibrium points, (m + 1) n of which are locally exponentially stable. Different from the traditional multistability analysis method such as fixed point theory, this paper only uses the character of activation functions, and can also handle the neural networks with disturbance term. The research results of this paper generalize the previous related research works and are easy to test. A numerical example is given to shown the effectiveness of our theoretical results. [ABSTRACT FROM AUTHOR]

Companies operating in global production networks face increasing complexity, uncertainty, and volatility making them more susceptible to disruptions. However, disruption management is characterized by intuitive reactions that focus exclusively on production or logistics, making cross-cutting solutions difficult. Therefore, this paper presents an approach to an integrated disruption management that combines production and logistics perspectives by considering relevant network partners in order to implement efficient, network-optimal (combinations of) countermeasures to disruptions. Using simulation, design of experiments, and metamodeling of cause-effect relationships between disruptions, countermeasures, and network performance, the approach enables fostering network robustness by efficient decision-making in highly complex environments. [ABSTRACT FROM AUTHOR]

• Agents communicate indirectly and asynchronously via a shared cloud repository. • Both globally and locally Lipschitz nonlinearity in system dynamics are discussed. • Adaptive control scheme is considered for multi-agent systems under directed graph. • Practical tracking consensus is achieved for multi-agent systems with disturbances. • Zeno-freeness is guaranteed for the proposed cloud-based self-triggered scheme. This paper addresses the practical tracking consensus problem for first-orderheterogeneous nonlinear multi-agent systems in presence of external disturbances under directed graphs. Agents with limited communication capability interact with each other through a cloud repository, where the information exchange is asynchronous and indirect. The system model is more general than the ones in existing results, moreover, locally Lipschitz nonlinearities and adaptive control schemes are taken into account. It is proven that under the designed self-triggered protocol, agents can track a virtual leader with bounded error and Zeno behaviour is excluded for real implementation. Finally, a numerical simulation demonstrates the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

Due to the increasing needs on the performance of satellites, in particular optical satellites, microvibrations have become more and more important over the last years. Microvibrations affect a large number of satellites for both Earth observation and space observation missions. Further, microvibrations are also a concern for other missions with sensitive instruments like Fourier spectrometers, high-precision accelerometers or reference oscillators. In classical fields like structural dynamic engineering, management approaches have been established and implemented in all space projects. This paper presents a corresponding approach for the area of microvibrations. Focus is on the definition of all key elements needed to establish a microvibration control approach. This includes the establishment of microvibration budgets and associated summation rules. A systematic way for microvibration disturbance minimization is presented and rules for the application are defined. Specific emphasis is given to the definition of microvibration interface requirements and the associated control process. The concepts provided in this paper have been verified by tests performed in the frame of various satellite programs and studies. Tests related to the superposition of different noise sources are presented in here. • Spacecraft performance budgets related to microvibrations are established using adaptation of standard ECSS rules. • Microvibration interface requirements are defined using an optimized margin approach. • Microvibration requirement definition and verification concepts are defined for typical satellite architectures. • Assuming linear summation of different microvibration noise sources overestimates the performance impact. [ABSTRACT FROM AUTHOR]

• A disturbance simulation model of tooth-flexible body residual film-soil based on DEM-MBD was established. • The flow characteristics of film-soil was studied using DEM-MBD simulation methods. • A film picking test bench was established to verify the reliability of the simulation model. • The cross-sectional shape of soil was used to verify the accuracy of DEM simulation models. • The mechanical properties and tensile performance of the residual film were analyzed. The residual film in the cotton cultivation layer will seriously affect cotton cultivation, and mechanized recycling of residual film is currently the best way to solve this problem. To improve the recovery effect of the chain tooth tillage layer residual film recovery machine, a bionic elastic tooth was designed in this paper. Furthermore, DEM-MBD coupling multibody dynamics was used as the research method to study the bionic elastic tooth-residual film-soil interactive disturbance. A DEM-MBD simulation model for predicting the film lifting effect of a film lifting device has been established. And the DEM-MBD simulation model was used to optimize the design parameters of the film lifting device by studying the film lifting effect of the elastic teeth. The absolute value of the maximum curvature at the tip of the elastic tooth (A), the angle between the midline of the power wheel and the ground plane (B), and the spacing of the elastic teeth (C) were used as the influencing factors. The optimal solution parameters (A = 0.03, B = 54°, C = 83 mm) were obtained. The field test's film picking and disturbance rate was 91.27 %, the error with the simulation results (89.69 %) was 1.8 %, which verified the accuracy of the simulation results and the superiority of the optimized parameters. The recovery rates of residual film under soil compaction conditions of 600 kPa, 800 kPa, and 1000 kPa were 91.25 %, 90.94 %, and 90.89 % (Verified the strong adaptability of the device). This study can provide a theoretical research basis and test methods for the design optimization of touching parts. [ABSTRACT FROM AUTHOR]

• Attitude system of quadrotor unmanned aerial vehicle (QUAV) with disturbance and gyroscopic effect is developed. • Transient chaos in the disturbed QUAV system is found and analyzed via multi-parameter bifurcation diagrams. • Existence of chaos for angular velocity of QUAV is verified analytically and experimentally. • QUAV Chaos is suppressed by the designed back-stepping sliding mode controller, and stability is proved and verified. The disturbance influences the dynamic characteristics of the quadrotor unmanned aerial vehicle (QUAV), especially the stability. With the disturbance, the study of characteristics and controller design is challenging. In this paper, an attitude system of a QUAV with disturbance and gyroscopic effect is developed. The disturbed QUAV attitude system dynamics influenced by the rotor speeds are analyzed via multi-parameter bifurcation diagrams. The chaotic parameter area in which the QUAV is in an abnormal vibration state is plotted, guiding the design of the fuselage structure and controller of the QUAV. The transient chaos characterizing chaos within a long period but eventually becoming periodic is found in the system. The chaotic phenomenon of the angular velocity trajectory of the QUAV is verified by obtaining the positive Lyapunov exponent using the experimental data. A back-stepping sliding mode controller is designed, and the stability of the closed system is proved via the Lyapunov method. Numerical simulations verify the effectiveness of controlling the QUAV. The designed controller is effective for suppressing chaos. The stability of the back-stepping sliding mode controller is superior to that of the PID controller is verified via numerical simulations. [ABSTRACT FROM AUTHOR]

• Control scheme design of the benzene/isopropanol/water separation. • Open loop steady-state gain analysis to determine temperature sensitive plates. • Robust control of sensitive plate temperature by the steam separation ratio (β V). • Dynamic performance comparison of CED and DWED. The effective separation of the ternary azeotrope benzene/isopropanol/water has high economic benefits in industry. It is of great significance to study the dynamic controllability of this ternary azeotropic system. In this paper, dynamic control schemes of the conventional extractive distillation (CED) and the dividing wall extractive distillation (DWED) for benzene / isopropanol / water separation with ethylene glycol (EG) as extractant were studied. The open loop steady-state gain analysis is used to guide the control structure improvement, a multi-point temperature control strategy based on the sensitive stage temperatures is proposed to improve the control scheme. In the CED process, the improved control scheme can resist ±20% feed flow and composition disturbances. In addition, it is demonstrated that using the steam separation ratio (β V) to control the sensitive stage temperature shows better dynamic performance compared with using the ratio of the steam side flowrate and the reboiler heat duty (V/R) to control the sensitive stage temperature in the DWED process. Finally, by comparing the integral of squared error (ISE) values, it is found that improved control schemes (CS2 and CS4) have better robustness and dynamic performance. [Display omitted] [ABSTRACT FROM AUTHOR]

• The problems of finite-time stabilization for nonlinear impulsive systems subject to nonvanishing and vanishing disturbances are investigated in this paper. • The relationship among the external disturbances, impulsive frequency and the system structure is established. Stabilizing effects of impulses are effectively utilized to deal with the instability caused by external disturbances. • Our results extend the practical finite-time stability and finite-time stability of continuous-time systems to impulsive systems. What we concern in this paper is finite-time control of nonlinear impulsive systems involving external disturbance, where practical finite-time and finite-time stabilization are studied with respect to nonvanishing and vanishing disturbance, respectively. A relationship between the finite settling time and the impulsive frequency is presented to show the stabilizing effect of impulses. It is shown that systems subject to nonvanishing disturbance can enter a disturbance-dependent ultimate bound in a finite-time sense, and a relatively smaller bound of settling time is obtained by utilizing stabilizing impulses. Meanwhile, systems subject to vanishing disturbance can achieve finite-time stabilization at the origin. Moreover, compared with the situation without impulses, the corresponding bound of settling time is also smaller. For the sake of illustrating the validity of proposed results, some examples and their simulations are provided. [ABSTRACT FROM AUTHOR]

The Cell Transmission Model (CTM) has been widely used to design variable speed limit (VSL) controllers. Since the CTM is an idealization of the actual traffic flow, the issue of robustness of VSL with respect to uncertainties such as disturbances due to modeling and measurement errors is an important problem. In this paper, we modify the CTM to include a constant disturbance term that is unknown and could change over time. The stability properties of the modified open-loop CTM are analyzed and used to motivate the design of a robust VSL controller. The VSL controller is designed to reject external disturbances, which are constant over large intervals of time, while guaranteeing that the density converges to the desired equilibrium state corresponding to high flow and speed. Microscopic simulations based on the commercial software VISSIM are used to demonstrate the effectiveness of the proposed robust VSL controller and associated benefits for traffic scenarios along a large segment of I-710 in Southern California. [ABSTRACT FROM AUTHOR]

This paper studies the problem of the state estimate of a class of DC microgrids with both disturbed states and disturbed outputs via event-triggered impulsive observer (ETIO). First, a mathematical model is established for such class of DC microgrids, and then the notion of impulsive observer including impulsive observer with K -asymptotic gain is proposed. Then, by using two Lyapunov-like functions, a scheme of event-triggered impulsive control (ETIC) via three layers of event-triggering conditions is designed for ETIO to track the state of the DC microgrid. And an algorithm is given for the implementation of ETIC in practice. The ETIC scheme is then extended to the sampling-based ETIC (S-ETIC) to reduce the calculation and improve the effectiveness of the ETIC. Both theoretical proofs and numerical simulations are given to show that the proposed ETIO via both ETIC and S-ETIC can track the state of the DC microgrid within K -asymptotic gain. Specifically, when the disturbance tends to zero, the tracking is accurate. Moreover, the simulation is given for comparisons between ETIO and other observers including the classic impulsive observer, Luenberger observer, sliding mode observer, and extended state observer. It is shown that the designed ETIO has advantages of lower impulse frequency, lower control cost, and smaller tracking error than the other observers. • A model of DC MGs with both disturbed states and outputs is established. • An event-triggered impulsive observer (ETIO) is constructed for the MGs. • The schemes of event-triggered impulsive control are proposed for ETIO. • ETIO tracks the MGs with lower frequency and less cost and smaller error. [ABSTRACT FROM AUTHOR]

The runner motions in a foil thrust bearing system typically consist of axial pulsations and angular wobbles as a result of manufacturing and assembly tolerances. By considering the disturbances caused by the runner, this paper established a dynamic model of a foil thrust bearing that has an angular swinging bearing pad. The influence of angular disturbance on the load-carrying capacity (LCC) of the bearing was theoretically and experimentally studied. It was found that the LCC of the bearing under angular disturbances can be enhanced by introducing a proper angular tracking ability. In this paper, the LCC of the bearing was increased by approximately 50% with the angular tracking ability provided by the swinging bearing pad. [ABSTRACT FROM AUTHOR]

This paper mainly studies quasi-bipartite synchronization (QBPS) of signed delayed neural networks (SDNNs) under impulsive effects, in which the nodes have cooperative as well as antagonistic interactions. It is assumed that disturbance occurs in the communication channels between some neighboring agents at impulsive occurring instants. Under the balanced network topology, some sufficient criteria to achieve QBPS of SDNNs are proposed by utilizing algebraic graph theory and extended Halanay differential inequality. Moreover, for the QBPS error of SDNNs, the upper bound of the final error state is also provided explicitly. Two numerical examples are presented to demonstrate the correctness of the theoretical results. [ABSTRACT FROM AUTHOR]

Design of an adaptive anti-unwinding finite time sliding mode algorithm for attitude control system of a three-axis satellite is approached in this paper. In the designed controller, some parameters updating laws are proposed to simultaneously obtain the accurate values of inertia moments, the upper values of reaction wheels' failures and disturbances. Accordingly, the combined finite time stability of the control system and convergence of the satellite parameters has been demonstrated. Also, a new sliding surface is suggested to avoid the unwinding problem which is common in sliding mode techniques. It is proved by the Lyaponov methodology that the satellite quaternions and angular velocities always approach to the nearest equilibrium point and so it prevents the excessive satellite slews. Furthermore, the proposed algorithm has been modified in such a way that the singularity problem does not occur, especially when the system states reach around the equilibrium point. Therefore, the finite time convergence of system states and parameters estimation errors are guaranteed subjected to disturbances and actuator failures without occurring singularity and unwinding problems. Besides rigorous theoretical proofs by the Lyapunov theory, different simulations are exhibited to demonstrate the merits of the developed control schemes. • An adaptive finite time sliding mode control is proposed for a rigid satellite. • The finite time stability is ensured despite accurate estimation of parameters. • The upper bound of disturbances and actuator failures are estimated. • The unwinding and singularity problems are prevented. • It is concluded that the suggested controller has superior accuracy and chattering. [ABSTRACT FROM AUTHOR]

A robust optimal control method for a class of nonlinear systems with unknown disturbances is addressed in this paper. In this framework, adaptive dynamic programming (ADP) is presented to obtain the optimal control. On-policy learning allows the performance index function and the optimal control to be obtained iteratively. It is shown that the iterative performance index function is non-increasing. A nonlinear disturbance observer is designed to estimate external disturbances. The compensation control is used to compensate for the influence of the disturbances. It is proven that the disturbance observer error is exponentially stable, under some conditions. The properties of the nonlinear system with unknown disturbance steered by the robust optimal control input are also proven. Simulation results demonstrate the performance of the proposed robust optimal control scheme for the nonlinear system with unknown disturbance. [ABSTRACT FROM AUTHOR]

This paper deals with the simulation of unexpected disruptions in public transport in the agent-based transport simulation framework of MATSim. A replanning logic for public transport passengers is implemented so passengers can be informed about and react to a disruption and use an alternative route. An unexpected disruption of an underground line in Berlin is simulated to analyze how passengers are affected by the disruption and the information time. It is shown that transport companies can minimize the negative effects of unplanned disruptions by informing their passengers as soon as possible once the disruption has occurred because travel times increase drastically when passengers are informed late. [ABSTRACT FROM AUTHOR]

Offshore surveying from seismic airgun arrays and other intense types of industrial development introduce substantial underwater noise, with potentially serious consequences for marine life. We describe an adaptive spectrum of data collection and analytical methods to evaluate the type, magnitude, and complexity of disturbance associated with industrial activities. Scientists and managers have often been mired in a cycle of mitigation and monitoring plans and data collection schemes that focus solely on the prevention of significant but generally rare instances of injury or death. Increased focus is needed on achieving a refined understanding of the sub-injurious but vastly more common impacts of disturbance on energetics, reproduction, and survivorship at population levels. Approaches that apply and adapt earlier knowledge and integrate tools tuned to exposed species, exposure type, and situational context can provide more insightful understanding of likely effects to inform effective monitoring, and mitigation. Such approaches require multi-disciplinary measurement technologies and individual/population-level statistical models to demonstrate how various types and levels of acute and chronic anthropogenic noise affect marine life. Standardized biological data (e.g., distribution, animal tracking, behavior) should be collected within structured, prioritized, and integrated methodological and analytical frameworks before, during, and after noise-generating activities. This paper sets forth an 'ideal' approach for planning, collecting data, and conducting analyses to test for effects of noise on baleen whales. The approach can range from simple to complex, depending on the context. Further, we discuss and recommend methods for analyzing sampling data using currently available tools and guidelines, including behavioral response severity metrics, acoustic criteria, and bioenergetic and population effects models. [ABSTRACT FROM AUTHOR]

Abstract: Background: Those at the birth of a baby sometimes speak of the experience as significant and meaningful; an experience in which there is an atmosphere or mood that surrounds the occasion. This paper explores this mood, its recognition, disclosure and how we attune or not to it. The paper is philosophically underpinned by hermeneutic phenomenology. The Heideggerian notion of “attunement to mood” is used to interpret this phenomenon. This paper describes how such a mood becomes visible. Methods: Using a hermeneutic phenomenological approach, 14 tape-recorded transcribed interviews, each about an hour long, were conducted over 8 months from mothers, birth partners, midwives and obstetricians. The stories crafted from these transcripts have been interpreted alongside my own preunderstandings and related literature. Appropriate ethical approval was gained. Findings: Analysis suggests that there is a positively construed mood of joy at birth that can be concealed when disrupted. Disturbing this mood has the effect of exposing the world of birth and its inherent activities and feelings revealing possible meanings inherent in the lived birth experiences. Disturbances at birth provide distinctions and tensions in which a concealed constitutive mood at birth can be seen. This paper provides insight towards a deeper appreciation into how the sacred joy of birth may be protected. Implications for practice: The way in which we attune to birth may have consequences to birth outcomes and to the experience of childbirth. The consequences of these findings for those in the world of birth are discussed. [Copyright &y& Elsevier]

• A difference operator is proposed to reject the disturbance effect and a new instrumental variable is proposed to eliminate the noise effect for consistent estimation. • The new instrumental variable enhances the estimated model efficiency/accuracy, as supported by consistent analysis. • The auxiliary static-gain information is used to enhance the accuracy of the estimated quantities. • Compared with SIMs using no priori-knowledge, the proposed method could reduce the estimation error variances of the system matrices B and D, as supported by variance analysis. • A prior knowledge-based subspace identification method is proposed for batch processes subject to repeatable disturbances. In this paper, a prior-knowledge-based subspace identification method (SIM) is proposed for batch processes subject to repeatable disturbances. The proposed method is a two-step procedure for state-space model identification: in the first step, the extended observability and triangular Toeplitz matrices are estimated simultaneously from a parity space of the experimental data and, based on which, the corresponding system matrices are retrieved in the second step. More specifically, A and C are retrieved from the estimated extended observability matrix, while B and D are retrieved from the estimated triangular Toeplitz matrix. The proposed method shows several superiorities in the following aspects. Firstly, it is able to provide unbiased parameter estimation in the presence of repeatable disturbances, thanks to the proposed difference operator which eliminates the disturbance effect. Secondly, it shows better robustness to measurement noise compared with the existing SIMs using parity space, due to the inherent instrumental variable mechanism and the new technique to build the instrument, which greatly enhance the estimated model efficiency/accuracy. Lastly, by taking the auxiliary static-gain information into account in the identification procedure, the variance properties of the parameters can be improved, especially for the system matrices B and D. All the above-mentioned developments are analyzed with strict mathematical proofs, along with two illustrative examples to confirm the effectiveness and merits. [ABSTRACT FROM AUTHOR]

Highlights • Both robust observer and observer-based control designs are studied. • The class of nonlinearities is broader than traditional Lipschitz nonlinearities. • New approach to the robust observer design problem for discrete uncertain systems. • Design conditions derived in terms of LMIs after linearizing the bilinear terms. • Advantages of new results over existing works illustrated via a numerical example. Abstract In this paper, we study the robust observer design and observer-based control design problems for a class of discrete one-sided Lipschitz systems subject to uncertainties and disturbances. The nonlinearities are assumed to be one-sided Lipschitz and quadratically inner-bounded. By utilizing a new approach which is an extension of the H ∞ filtering method, our robust observer design can relax some limitations in existing works. In order to derive design conditions in terms of linear matrix inequalities, several mathematical techniques are appropriately used to linearize the bilinear terms which unavoidably emerge in observer and observer-based control designs for discrete-time uncertain systems. Via a numerical example, we show that while existing works fail, our results work effectively. [ABSTRACT FROM AUTHOR]

There are many processes in the business world which are dependent on Critical Infrastructure Systems (CISs) to provide important services. Hence, undesirable behaviors of these processes can provide cascading disturbances and might cause high impacts on criticality infrastructure in Automatic Closed-Loop Supply Chain (A-CLSC). Thus, this level of vulnerability needs to monitor and control the disturbances related to uncertain parameters. In order to develop the controller component inward uncertain Business Process Management System (BPMS), the authors provided adaptive controller considering uncertainty, which could be tuned with an intelligent algorithm called Improved Particle Swarm Optimization (IPSO). In addition to multi-objective optimization, the novel controller has been used to control the two most important activities includes inventory and transportation evolving the criticality infrastructure in A-CLSC at the desired behavior as a simulation and practical case study. Furthermore, the proposed IPSO algorithm has been compared against legendary methods such as adaptive PSO (APSO) and classic PSO. Also, the paper has been provided some metrics to statistical evaluation of proposed method performance. The results indicated the better set response of the new controller to control the A-CLSC as well as effective control of CISs. [ABSTRACT FROM AUTHOR]

Highlights • The coupling correlation within organic Rankine cycle is revealed by dynamic test. • A system-level model is simulated by imposing the real-time experimental parameters. • The average overshoot of the evaporation pressure of 48 kPa is captured by the model. • The model predicts that the max desired power output is 1874.7 W with efficiency of 6.94%. Abstract This paper aims to reveal the coupling correlation of the ORC related system, and verify the boundaries and feasibilities of the system-level modeling. A kW-scale ORC test rig with a self-made expansion valve is set up for the dynamic test under three common freedoms, namely the mass flow rate of working fluid, heat source and cooling source. By imposing the same real-time experimental conditions, the system-level dynamic simulation is performed on the Modelica/Dymola software. The test rig and dynamic model are of high-accuracy and reliable after examining the heat balances and error propagation of the measurement uncertainties, as well as calibrating with theoretical analysis. Results show that the internal disturbance of mass flow rate of working fluid significantly affect the states parameters. The external disturbance of mass flow rate of cooling source has a less effect on the states parameter, while the states parameters are insensitive to the external disturbance of mass flow rate of heat source. The simulation results are in agreement with the experimental results. The average overshoot of the outlet temperature of cooling source is 0.7 °C, and the average overshoot of the evaporation pressure is 48 kPa, which coincide with the results from the experiment under the disturbance of working fluid mass flow rate. It shows the potential of such simulation model to be a guided model, which also predicts that the maximum desired power output of the ORC test rig is about 1874.7 W, with the thermal efficiency of 6.94%. [ABSTRACT FROM AUTHOR]

Highlights • A model with sensor faults and disturbance is transformed by using a first-order filter. • Current sensor faults and disturbance are decoupled by coordinate transformation. • Sliding-mode observers are designed to estimate faults and disturbance. Abstract Current sensor faults leads to system degradation of a permanent magnet synchronous motor (PMSM) drive. Accurate estimation of the faults for fault-tolerant control has become an important issue. However, unknown disturbance in measurement circuits greatly aggravates the difficulty of the estimation and seriously influences the performance of the estimation. This paper presents a new estimation method of sensor faults and unknown disturbance in current measurement circuits for an interior PMSM drive system. The system model, which contains faults of virtual sensors for α β axis currents and the unknown disturbance, is first constructed. Then, the model is transformed into a model with actuator faults by a first-order low-pass filter. Moreover, the faults and disturbance in the model are decoupled by coordinate transformation. And sliding-mode observers are designed based on the new decoupled system. Single and simultaneous faults of current sensors and an unknown disturbance are accurately estimated based on sliding-mode equivalent control methodology. An experiment is carried out to demonstrate the validity and effectiveness of the method. [ABSTRACT FROM AUTHOR]

It is vital in the prevention of the ferroresonance to consider this phenomenon from new side. The design of the equipment needs deep studies to avoid such disturbance. This paper presents a new way in ferroresonance studies, by the use of the Root Cause Analysis (RCA) in a systematic step by step process to discover the true cause of this problem. A fault tree is built to identify all possible causes leading to the unwanted top event, that is the False Trip Analysis (FTA). Among large statistics of disturbances, the probability of occurrence of ferroresonance is stated, and using the most studied causes of this event, the tree of analysis is built till reaching the main disturbance. In each step, well-known possible causes are shown. Then, a barrier or possible solution corresponding to the cause is presented. The new probability of occurrence is then calculated. The obtained result is compared to the initial probability and a set of protection system is proposed. The advantage of this study is the possibility to reduce the occurrence of the ferroresonance by gathering the maximum detailed amount of possible causes and by choosing the best barrier corresponding to the cause. [ABSTRACT FROM AUTHOR]

Highlights • Dynamical analysis has been provided to describe nonlinear behavior of supercavitating vehicles. • Robust H∞ loop-shaping synthesis with modified PID algorithm is proposed to control the dive plane maneuver of the HSSV. • Multi-objective control problems are solved using BMI optimization of an equivalent Schur formula. • Control scheme has the low order structure and provides robustness against uncertainties. • Integrated robust controller can deal with high parametric uncertainties and suppress exogenous disturbances and sensor noises. Abstract The high-speed supercavitating vehicle (HSSV) utilizes advanced technology that enables an underwater vehicle to reach its unprecedented high speed. The vertical motion control of the HSSV is challenging problem because of its complex dynamics with nonlinear planing force, parametric uncertainties, external disturbances, actuator saturation, and sensor noises. This paper deals with dynamical analysis and a robust H∞ loop-shaping synthesis with modified PID (proportional-integral-derivative) algorithm to control the dive plane maneuver of the HSSV. Typically, the control scheme has the low order structure and provides robustness against dynamic uncertainties, which can be implemented using the bilinear matrix inequality (BMI) optimization of an equivalent Schur formula. Simulation results show that the controlled vehicle system provides good performance and high robustness against uncertainties, ensuring no-overshoot and fast in time-domain responses. In addition, the control algorithm can decouple the dynamic interactions in the multi-input multi-output (MIMO) system, overcoming parametric uncertainty, planing force, and actuator saturation while minimizing the effect of the strong external disturbances and measurement noises. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we consider the robust observer-based control design problem for discrete nonlinear systems with disturbances. A new approach is proposed to provide less conservative Linear Matrix Inequality control design conditions and enhance the robustness of control designs, where the observer and controller gains are computed independently. Both the one-sided Lipschitz condition and the Linear Parameter Varying approach, which are two well-known alternatives to the classical Lipschitz condition, are considered to address nonlinearities. Two numerical examples are presented to illustrate the superiorities of the new approach over the traditional H ∞ approach as well as relevant works in the literature. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a method of power quality classification using support vector machines (SVMs). In SVM training, the kernel parameters, and feature selection have very important roles for SVM classification accuracy. Therefore, most appropriates of these kernel types, kernel parameters and features should be used for the SVM training. In this paper to get optimal features for the classifier two stage of feature selection has been used. In first stage mutual information feature selection (MIFS) and in the second stage correlation feature selection (CFS) techniques are used for feature extraction from signals to build distinguished patterns for classifiers. MIFS can reduce the dimensionality of inputs, speed up the training of the network and get better performance and with CFS can get optimal features. In order to create training and testing vectors, different disturbance classes were simulated using parametric equations i.e., pure sinusoid, sag, swell, harmonic, outage, sag and harmonics and swell and harmonics. Finally, the investigation results of this novel approach are shown. The test results show that the classifier has an excellent performance on training speed, reliability and accuracy. [Copyright &y& Elsevier]

Abstract: This paper discusses the adaptive control for the uncertain discrete time linear systems preceded by hysteresis nonlinearity described by the Prandtl–Ishlinskii (PI) model. The contribution of the paper is the development of an adaptive algorithm in which a pseudo-inversion is introduced to avoid difficulties of the directly inverse construction for complex hysteresis models, especially for the unknown hysteresis case. In the developed approach, only those parameters in the formulation of the sliding mode controller are adaptively estimated. The stability in the sense that all signals in the loop remain bounded is analyzed. Simulation results show the effectiveness of the proposed algorithm. [Copyright &y& Elsevier]

In this paper, the analysis, design and fabrication of an Octorotor Miniature Aerial Vehicle (MAV) are presented. This rotorcraft setup can act as an autonomous robot in outdoor environments to carry and move high payloads, and can thus also be used in object manipulation tasks. Within this paper, the system design, dynamic modeling, control system design, and its implementation are elaborated. The design procedure for this MAV includes two mechanics and electronics sub systems, which are thoroughly discussed. The mechanical design covers the aerodynamics analysis, body components, and propulsion system implementation. The electronic design includes hardware selection and control system design for the presented aerial robot. Since the MAV flies in outdoor environments, it additionally has to cope with windy conditions. Hence, the stabilization control scheme is considered along the lines of usual PID controllers. The attitude controller, as well as the inner and outer control loops, are fully studied, and a Fuzzy-PID controller is developed to improve the performance. Finally, considering maneuvers in two case studies, simulation and implementation results are studied and compared. [ABSTRACT FROM AUTHOR]

Abstract: The Great Lakes coastal region is a dynamic area at the interface between land and water. It is heavily influenced by the magnitude of the large lakes themselves, by natural abiotic and biotic processes in the watershed, and especially by human activity. This special issue contains a series of 21 papers that are organized into four major themes: 1) landscape characterization and coastal linkage, 2) integration, 3) indicator development, and 4) supporting information. The results of these papers emphasize that many environmental response signals are linked to their physio-biogeographic location in the basin and with human activity in coastal watersheds or in the immediate coastal margin. If lake levels continue to fluctuate and decline, if the climate continues to warm, if agricultural activity expands, if exotic species continue to invade, and if the human population density in the watershed increases, then environmental indicators of the Great Lakes coastal region reported here will point to further degradation of water quality and native amphibian, bird, diatom, fish, macroinvertebrate, and wetland plant communities. These environmental indicators are benchmarks for the current conditions of the Great Lakes coastal region and provide measurable endpoints to assess the success of future management, conservation, protection, and restoration of this important resource. [Copyright &y& Elsevier]

Abstract: Spruce budworm outbreaks are a major disturbance determining boreal forest dynamics in forests dominated by balsam fir. However, these forests have been anthropogenically disturbed in recent decades by clearcutting with protection of advance regeneration and soils which it has been suggested, emulates spruce budworm outbreaks by leaving a seedling bank while removing the overstory. The main objective of this study is to characterize and compare the effects of a spruce budworm outbreak to the effects of this harvesting treatment in balsam fir stands in the Gaspe Peninsula. The study was conducted at two different scales; the stand scale, by field sampling vegetation, and at the landscape scale, through the interpretation of aerial photographs. At the stand scale, results showed a more important structural variability in stands affected by the spruce budworm outbreak. There was a greater diversity of saplings and trees, especially paper birch and white spruce, in post-outbreak stands by comparison to post-logged stands. At the landscape scale, canopy openings created by clearcutting with protection of advance regeneration presented less regular shapes, but still had smaller perimeter/area ratio because of their larger size. Spruce budworm openings are thus more likely to be influenced by the surrounding forest and recolonisation by tree species should be faster than for clearcut openings. Our results suggest that efforts should be made to maintain the associated species (paper birch (Betula papyrifera Marsh.) and white spruce (Picea glauca (Moench) Voss)) by preserving more overstory trees of these species while managing the balsam fir dominated forest. Aggregation of cutting units should be limited and there is a need to create more small canopy openings in the landscape if we are to emulate naturally created patterns. [Copyright &y& Elsevier]

Multi-temporal change detection is commonly used in the detection of changes to ecosystems. Differencing single band indices derived from multispectral pre-and post-fire images is one of the most frequently used change detection algorithms. In this paper we examine a commonly used index used in mapping fire effects due to wildland fire. Subtracting a post-fire from a pre-fire image derived index produces a measure of absolute change which then can be used to estimate total carbon release, biomass loss, smoke production, etc. Measuring absolute change however, may be inappropriate when assessing ecological impacts. In a pixel with a sparse tree canopy for example, differencing a vegetation index will measure a small change due stand-replacing fire. Similarly, differencing will produce a large change value in a pixel experiencing stand-replacing fire that had a dense pre-fire tree canopy. If all stand-replacing fire is defined as severe fire, then thresholding an absolute change image derived through image differencing to produce a categorical classification of burn severity can result in misclassification of low vegetated pixels. Misclassification of low vegetated pixels also happens when classifying severity in different vegetation types within the same fire perimeter with one set of thresholds. Comparisons of classifications derived from thresholds of dNBR and relative dNBR data for individual fires may result in similar classification accuracies. However, classifications of relative dNBR data can produce higher accuracies on average for the high burn severity category than dNBR classifications derived from a universal set of thresholds applied across multiple fires. This is important when mapping historic fires where precise field based severity data may not be available to aid in classification. Implementation of a relative index will also allow a more direct comparison of severity between fires across space and time which is important for landscape level analysis. In this paper we present a relative version of dNBR based upon field data from 14 fires in the Sierra Nevada mountain range of California, USA. The methods presented may have application to other types of disturbance events. [Copyright &y& Elsevier]

This paper provides contextual documentation of the LANDIS model development to provide a framework for the other papers in this special issue. The LANDIS model of forest landscape disturbance and succession was developed since the early 1990s as a research and management tool that optimizes the possible landscape extent (100sha to 1000skm2), while providing mechanistic detail adequate for a broad range of potential problems. LANDIS is a raster model, and operates on landscapes mapped as cells, containing tree species age classes. Spatial processes, such as seed dispersal, and disturbances such as fire, wind, and harvesting can occur. LANDIS development benefited from the modelling and research progress of the 1960s to the1980s, including the growth of landscape ecology during the 1980s. In the past decade the model has been used by colleagues across North America, as well as in Europe and China. This has been useful to those not able to undertake the cost and effort of developing their own model, and it has provided a growing diverse set of test landscapes for the model. These areas include temperate, southern, and boreal forests of eastern North America, to montane and boreal western forests, coastal California forest and shrub systems, boreal Finnish forests, and montane forests in Switzerland and northeastern China. The LANDIS model continues to be refined and developed. Papers in this special issue document recent work. Future goals include integration within a larger land use change model, and applications to landscape and regional global change projection based on newly incorporated biomass and carbon dynamics. [Copyright &y& Elsevier]

• A reliable protection criterion for low-voltage PV systems is presented based on the rapid processing of current data to form multiple criteria identification characteristics to identify overcurrent caused by fault or non-fault. • The proposed anti-malfunction mechanism successfully resists the maloperation of the PV integration system during transient disturbances, enhancing immunity to inrush current caused by fluctuations in solar irradiance and PV system switch-on. • The proposed method can quickly respond and reliably protect the feeder by retrieving and analyzing single-end signals without the need for communication synchronization. • The prevention for protection can overcome the limitation of maloperation associated with overcurrent-based protection during weather intermittency. Non-fault situations in a photovoltaic (PV) integration system, such as solar irradiance fluctuations and intermittency, may be detected as faults by overcurrent-based protection and lead to an unnecessary network outage. Therefore, this paper proposes a maloperation prevention strategy for overcurrent protection based on multiple criteria to accurately distinguish between fault and non-fault states in the PV integration system and prevent the transient overcurrent from causing breaker trips. A fault diagnosis algorithm is proposed for determining the fault and disturbance states by analyzing current changes and their integration over a time delay. The results obtained from both PSCAD/EMTDC simulation and hardware-in-the-loop testing demonstrate the effectiveness of the proposed method in identifying network faults and disturbances, thereby showcasing its ability to provide reliable protection with robustness against weather intermittency. Compared with existing methods, the proposed method demonstrates superior performance in response time, applicability and implementation. These characteristics offer assurances for the dependable and efficient operation of PV integration systems. [ABSTRACT FROM AUTHOR]

• The q -difference operator is introduced into the study of fractal objects generated from the quadratic map. • Enrich the research of the fractional q-difference system to open up a new viewpoint for exploring their complex dynamics. • Provide potential inspiration for the qualitative analysis and fractal control of the fractional quantum Julia set. This paper proposes fractional quantum Julia sets based on a fractional q -difference map and preliminarily investigates their fractal dynamic characteristics by numerical methods and graphical explorations. The influence of parameters on the novel fractal sets is performed by dimension analysis. Memory and scale mainly affect the appearance and existence of the sets, respectively. The robustness of the sets to three types of dynamic noise perturbations is discussed by the Julia deviation tools. In particular, the deviation index is fitted concerning noise intensity. Several extensive numerical experiments are done to support the main conclusions. [ABSTRACT FROM AUTHOR]

In the present paper, the effects of external disturbances on cross-flow vortex-induced vibrations (VIVs) of a top tensioned riser are investigated based on a wake oscillator model. Two different flow conditions, namely uniform and linearly sheared profiles, and different combinations of disturbance frequency and amplitude were considered. Simulation results showed that synchronization between VIV and disturbance can occur when the disturbance frequency approaches the Strouhal frequency or when the disturbance amplitude is significant. This synchronization leads to a significant increase in riser response and the commonly used industry practice of simulating VIV and disturbance independently and summing both could underestimate the actual fatigue rate in such condition. However, in certain cases where VIV did not lock onto the disturbance, it was found that the disturbance could suppress the VIV and the industry practice tends to overestimate the fatigue rate. [ABSTRACT FROM AUTHOR]

This paper addresses the reachable set bounding for discrete-time switched nonlinear positive systems with mixed time-varying delays and disturbance, which contains switched linear positive systems as a special case. By resorting to a new method that does not involve the common Lyapunov–Krasovskii functional one, explicit criteria to ensure any state trajectory of the system converges exponentially into a prescribed sphere are obtained under average dwell time switching. The results can then be extended to more general time-varying systems. Finally, two numerical examples are used to demonstrate the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

Airports, especially international ones, within the urban context should have a specific consideration so they do not affect human lives. The planes fly a few hundred meters above these urban fabrics, and when they are landing, they fly slightly over 20–40 m above the ground. This paper aims to measure aircraft noise, conduct a survey on the subjective reaction of residents to aircraft noise, and present primary data necessary to secure the acoustic performance of residential buildings neighboring an international airport. The methodology used a field survey for six buildings neighboring Dubai International Airport in the United Arab Emirates, analyzed building/window material, and a subjective reaction survey. The result showed that the average equivalent noise level (L eq) was 66.4 dB(A), and the average maximum noise level (L max) was 73.3 dB(A). The indoor noise of the target buildings was found to be in the range of NC-35 to NC-53, exceeding NC-30, the permissible noise standard. The average noise level difference between indoors and outdoors was 13.6–30.5 dB(A). It was statistically proven that aircraft noise is a significant source of sound pollution and occurs all day throughout the year, regardless of the season. The response rate for loudness and noisiness was found to be very high. Regarding the disturbance in daily life due to annoyance, aircraft noise is significantly affected in the order of telephone calls, conversations, listening to TV and radio, sleep disturbance, concentration disturbance, and rest disturbance. This study will serve as primary data to present basic data necessary to secure an optimum acoustic performance of a residential building against aircraft noise. [ABSTRACT FROM AUTHOR]

Earth pressure balanced shield machine (EPBS) is widely adopted for metro tunnel construction in urban areas. Support pressure on excavation face and grouting at the EPBS tail are the main measures to control the ground disturbance and settlement. The post-construction settlement is of significance to the serviceability of metro tunnel. By weakening the compression parameters of underlying soils related to soil disturbance degree (SDD) and using layer-wise summation method, this study developed a method to predict the post-construction ground and tunnel settlement. The SDD is quantitatively evaluated by the shear-strain state obtained from a series of isotropically consolidated undrained triaxial compression (CIU) tests. Based on a case history of metro tunnel constructed in structured soft soils, a suite of three dimensional finite-element analyses are performed to investigate soil disturbance during tunneling construction. The numerical simulation and the applicability of the proposed method are validated by comparing the numerical results with the field measurements. In addition, influences of support pressure and grout ratio on the tunneling-induced soil disturbance, ground and tunnel settlement are revealed. The SDD shows remarkable falloff within 0.32 D above the tunnel crown, while 0.24 D below the tunnel invert. Furthermore, within the above distance range, the linear relation between the SDD and distance from the tunnel crown or invert can be built. The analysis results show that the excessively high or low support pressure and grout ratio can both cause severe SDD which results in the significant post-construction settlement. Grout ratio of about 200% and support pressure of 2.2–2.4 P 0 are effective for reducing both the post-construction ground and tunnel settlement. The research presented in this paper provides a reference for controlling the post-construction ground and tunnel settlement constructed in structured soft soils. [ABSTRACT FROM AUTHOR]

This paper investigates robust finite-time stability problem of fractional-order systems (FOSs) with time-varying delay and nonlinear perturbation. Based on a generalized Gronwall inequality, a delay-dependent sufficient condition for robust finite-time stability of such systems is established in terms of the Mittag-Leffler function. Compared with the finite-time stability conditions in the literature, our condition is simple and convenient for testing and application. The obtained results are applied to finite-time stability of linear uncertain FOSs and linear non-autonomous FOSs with time-varying delays. A numerical example is given to show the effectiveness of the obtained result. [ABSTRACT FROM AUTHOR]

The development, implementation and enforcement of policies involving the rational use of the land and the conservation of natural resources depend on an adequate characterization and understanding of the land cover, including its dynamics. This paper presents an approach for monitoring vegetation dynamics using high-quality time series of MODIS surface reflectance data by generating fraction images using Linear Spectral Mixing Model (LSMM) over South America continent. The approach uses physically-based fraction images, which highlight target information and reduce data dimensionality. Further dimensionality was also reduced by using the vegetation fraction images as input to a Principal Component Analysis (PCA). The RGB composite of the first three PCA components, accounting for 92.9% of the dataset variability, showed good agreement with the main ecological regions of South America continent. The analysis of 21 temporal profiles of vegetation fraction values and precipitation data over South America showed the ability of vegetation fractions to represent phenological cycles over a variety of environments. Comparisons between vegetation fractions and precipitation data indicated the close relationship between water availability and leaf mass/chlorophyll content for several vegetation types. In addition, phenological changes and disturbance resulting from anthropogenic pressure were identified, particularly those associated with agricultural practices and forest removal. Therefore the proposed method supports the management of natural and non-natural ecosystems, and can contribute to the understanding of key conservation issues in South America, including deforestation, disturbance and fire occurrence and management. [ABSTRACT FROM AUTHOR]

Although tropical rainforests preserve high levels of biodiversity, they are among the most threatened ecosystems globally due to large-scale fragmentation as a result of anthropogenic activities. Overall, fast human-driven habitat destruction is suspected to be one of the major causes of species extinction. The mosaic of vegetation types, which contributes to the incredible diversity of the tropics is highly impacted by large-scale fragmentation. The main causes of such habitat fragmentation are selective logging for valuable timber and agricultural clearance. The knowledge of the short and long-term effects of removing selected species in the tropical rainforests are scarce and need to be further investigated. Some studies about the effects of tropical forest disturbance in the short term have been conducted, but in the long term, there is limited knowledge. In this paper, I consider a system of coupled ordinary differential equations (ODEs) that modelled the dynamics of tropical rainforest subject to selective logging to understand how and why weeds and vine displace and limit tree species. From the empirical data collected on canopy height and plant diversity and the model proposed, I have the evidence of a decreasing tree diversity in tropical forests subject to management in comparison with to the same but untouched forests. [ABSTRACT FROM AUTHOR]

Zoogeomorphology, the study of animals as geomorphic agents, has been largely overlooked in the context of resilience theory and biogeomorphic systems. In this paper, examples are provided of the interactions between external landscape disturbances and zoogeomorphological agents. We describe cases in which naturally occurring zoogeomorphological agents occupy a landscape, and examine whether those zoogeomorphic agents provide resilience to a landscape or instead serve as a landscape stress capable of inducing a phase-state shift. Several cases are described whereby the presence of exotic (introduced) zoogeomorphic agents overwhelms a landscape and induce collapse. The impact of climate change on species with zoogeomorphological importance is discussed in the context of resilience of a landscape. We conclude with a summary diagram illustrating the relationships existing between zoogeomorphic impacts and landscape resilience in the context of our case studies, and speculate about the future of the study of zoogeomorphology in the framework of resilience theory. [ABSTRACT FROM AUTHOR]

This paper addresses the design of sampled-data output feedback control for nonlinear systems in the presence of exogenous disturbance, which is based on the state feedback control for the continuous-time system. It connects the relationship of uniform regional input-to-state stabilization of sampled-data controller with state feedback control for the original continuous-time system. It shows that not only ISS but also trajectories convergence will be recovered, provided sufficiently small sampling period. Moreover, the advantage of the proposed method of designing a sample-data controller over that of designing a discretized controller for an approximate model is illustrated. An application using high-gain observers to a nonminimum phase single-link flexible robot demonstrates the simplicity of synthesis procedure of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new method, by designing an unknown input type state observer, to stabilize an unstable 1-d heat equation with boundary uncertainty and external disturbance. The state observer is designed in terms of a disturbance estimator. A stabilizing state feedback control is designed for the observer by the backstepping transformation, which is an observer based output feedback stabilizing control for the original system. The well-posedness and stability of the closed-loop system are concluded. The numerical simulations show that the proposed scheme is quite effectively. This is a first result on active disturbance rejection control for a PDE with both boundary uncertainty and external disturbance. [ABSTRACT FROM AUTHOR]

In rivers, the ecological effects of drought typically result in gradual adjustments of invertebrate community structure and functioning, punctuated by sudden changes as key habitats, such as wetted channel margins, become dewatered and dry. This paper outlines the development and application of a new index (Drought Effect of Habitat Loss on Invertebrates – DEHLI) to quantify the effects of drought on instream macroinvertebrate communities by assigning weights to taxa on the basis of their likely association with key stages of channel drying. Two case studies are presented, in which the DEHLI index illustrates the ecological development of drought conditions and subsequent recovery. These examples demonstrate persistent drought effects months or several years after river flows recovered. Results derived using DEHLI are compared with an established macroinvertebrate flow velocity-reactive index (Lotic-invertebrate Index for Flow Evaluation – LIFE score) and demonstrates its greater sensitivity to drought conditions. Data from a number of rivers in south east England were used to calibrate a statistical model, which was then used to examine the response of DEHLI and LIFE to a hypothetical multi-year drought. This demonstrated a difference in response between sampling seasons, with the spring model indicating a lagged response due to delayed recolonisation and the autumn model differentiating habitat loss and flow velocity-driven responses. The application of DEHLI and the principles which underlie it allow the effects of drought on instream habitats and invertebrates associated with short or long term weather patterns to be monitored, whilst also allowing the identification of specific locations where intervention via river restoration, or revision of existing abstraction licensing, may be required to increase resilience to the effect of anthropogenic activities exacerbated by climate change. [ABSTRACT FROM AUTHOR]