A5070355016- Stability and Controllability of Differential Equations
- Stability and Control of Uncertain Systems
- Adaptive Control of Nonlinear Systems
- Mathematical and Theoretical Epidemiology and Ecology Models
- Control Systems and Identification
- Advanced Control Systems Optimization
- Numerical methods for differential equations
- Ecology and Vegetation Dynamics Studies
- Nonlinear Dynamics and Pattern Formation
- Advanced Mathematical Modeling in Engineering
- Quantum chaos and dynamical systems
- Evolution and Genetic Dynamics
- Control and Stability of Dynamical Systems
- Animal Ecology and Behavior Studies
- Model Reduction and Neural Networks
- Avian ecology and behavior
- Neural Networks and Applications
- Ecosystem dynamics and resilience
- Plant and animal studies
- Animal Behavior and Reproduction
- Advanced Mathematical Physics Problems
- Wildlife Ecology and Conservation
- Iterative Learning Control Systems
- Fish Ecology and Management Studies
- Mathematical Biology Tumor Growth
University of Exeter
2016-2025
University of Bath
1989-2021
National University of Distance Education
2021
Edinburgh Napier University
2021
Sustainability Institute
2021
University of Warwick
1987-2006
University of Szczecin
2005
Institute of Solid Mechanics
2002-2004
University of Botswana
2001
Vrije Universiteit Amsterdam
1990
Coronaviruses are a large family of viruses that cause different symptoms, from mild cold to severe respiratory distress, and they can be seen in types animals such as camels, cattle, cats bats. Novel coronavirus called COVID-19 is newly emerged virus appeared many countries the world, but actual source not yet known. The outbreak has caused pandemic with 26,622,706 confirmed infections 874,708 reported deaths worldwide till August 31, 2020, 17,717,911 recovered cases. Currently, there exist...
Abstract In this paper, a non-singular SIR model with the Mittag-Leffler law is proposed. The nonlinear Beddington-DeAngelis infection rate and Holling type II treatment are used. qualitative properties of discussed in detail. local global stability analyzed. Moreover, some conditions developed to guarantee asymptotic stability. Finally, numerical simulations provided support theoretical results used analyze impact face masks, social distancing, quarantine, lockdown, immigration, disease,...
Summary 1. Population dynamics often defy predictions based on empirical models, and explanations for noisy have ranged from deterministic chaos to environmental stochasticity. Transient (short‐term) following disturbance or perturbation recently gained attention researchers as further possible effectors of complicated dynamics. 2. Previously published methods transient analysis tended require knowledge initial population structure. However, this has been overcome by the recent development...
Summary 1. Effective population management requires accurate predictions of future dynamics and how they may be manipulated to achieve goals. 2. The R package popdemo provides software tools for novel analytical methods that aim enhance the predictive power basic projection matrix models. These include indices transient transfer function analyses. 3. We use a case study demonstrate importance these briefly discuss their potential application outside ecology.
We study a particular class of n-node recurrent neural networks (RNNs). In the 3-node case we use monotone dynamical systems theory to show, for well-defined set parameters, that, generically, every orbit RNN is asymptotic periodic orbit. then investigate whether RNNs this can adapt their internal parameters so as "learn" and replicate autonomously (in feedback) certain external signals. Our learning algorithm similar identification algorithms in adaptive control theory. The main feature...
Systems of globally coupled phase oscillators can have robust attractors that are heteroclinic networks. We investigate such a network between partially synchronized states where the phases cluster into three groups. For coupling considered there exist 30 different three-cluster in case five oscillators. study structure and demonstrate it is possible to navigate around by applying small impulsive inputs oscillator phases. This paper shows navigation may be done reliably even presence noise...
Summary The dynamics of structured plant populations in variable environments can be decomposed into the ‘asymptotic’ growth contributed by vital rates, and ‘transient’ caused deviation from stable stage structure. We apply this framework to a large, global data base longitudinal studies projection matrix models for populations. ask, what is relative contribution transient boom bust dynamic trajectories stochastic environments? Is patterned phylogeny, form or number life stages per...
Abstract The aim of this article is to help predict the course lung cancer patients. To make prediction as close reality possible, we used data from patients receiving treatment at Erciyes University Hospitals in Kayseri, Turkey. First, developed a mathematical model considering cells microenvironment tumors with assistance Caputo fractional derivatives. Subsequently, identified equilibrium points proposed and examined coexistence point. In addition, demonstrated existence uniqueness...
It is well known that closing the loop around an exponentially stable, finite-dimensional, linear, time-invariant plant with square transfer-function matrix $\BG(s)$ compensated by a controller of form $(k/s)\Gamma_0$, where $k\in {\Bbb R}$ and $\Gamma_0in R}\mm$, will result in stable closed-loop system which achieves tracking arbitrary constant reference signals, provided (i) all eigenvalues $\BG(0)\Gamma_0$ have positive real parts (ii) gain parameter k sufficiently small. In this paper...
Summary An important task in applied population ecology is to understand how changes individual life‐history parameters, such as survival, growth and fecundity, affect dynamics. Parameter changes, or perturbations, may be caused by deliberate attempts manage populations (e.g. pest control, harvesting conservation) they side‐effects of pollution, genetic modification climate change. For organisms with complicated life cycles, links between histories dynamics are made using projection matrix...
Summary 1. Population projection matrices (PPMs) are probably the most commonly used empirical population models. To be useful for predictive or prospective analyses, PPM models should generally irreducible (the associated life cycle graph contains necessary transition rates to facilitate pathways from all stages other stages) and therefore ergodic (whatever initial stage structure is in projection, it will always exhibit same stable asymptotic growth rate). 2. Evaluation of 652 171 species...
Abstract Many animal taxa exhibit sex‐specific variation in ecological traits, such as foraging and distribution. These differences could result responses to change, but demographic effects are poorly understood. Here, we test for the demography of northern (NGP, Macronectes halli ) southern (SGP, M. giganteus giant petrels – strongly sexually size‐dimorphic birds that breed sympatrically at South Georgia, Atlantic Ocean. Both species feed sea or on carrion land, larger males (30% heavier)...
A class of recurrent neural networks is shown to possess a stable limit cycle. gradient type algorithm used modify the parameters network so that it learns and replicates autonomously time varying periodic signal. The results are applied controlling repetitive motion two-link robot manipulator.
We consider well-posed linear infinite-dimensional systems, the outputs of which are sampled in a generalized sense using suitable weighting function. Under certain natural assumptions on system, function, and sampling period, we show that there exists hold function such unity sampled-data feedback renders closed-loop system exponentially stable (in state-space sense) as well L2 -stable input-output sense). To illustrate our main result, describe an application to structurally damped...