Richard H. Middleton

Bio: Richard H. Middleton is an academic researcher from University of Newcastle. The author has contributed to research in topics: Control theory & Linear system. The author has an hindex of 48, co-authored 393 publications receiving 12037 citations. Previous affiliations of Richard H. Middleton include Hamilton Institute & University of California.

On the Design of a Novel Control Algorithm and Communication Structure for Discrete-Time Multi-Agent Consensus Systems

Abstract: Multi-agent consensus systems have been investigated in the continuous-time setting in regard to the control design, their scalability, and their robustness to interference. The discrete-time setting lacks the same depth of investigation. This paper investigates discrete-time multi-agent consensus systems. In particular, we propose a new controller design. The design uses a linear controller that is independent of the number of agents connected and imposes a single constraint on the communication structure. This is a step towards a scalable multi-agent consensus system that allows simple connection of additional agents without readjustments to the controller.

Benders decomposition for a reverse logistics network design problem in the dairy industry

Abstract: Designing a value-creating whey recovery network is an important reverse logistics problem in the dairy industry. Whey is a byproduct of cheese making with many potential applications. Due to environmental legislation and economic advantages, raw whey should be processed into commercial products rather than disposed of into the environment. In this paper, we study a whey reverse logistics network design problem under demand uncertainty, where demand is the amount of raw whey produced by a set of cheese makers. We formulate the problem as a hierarchical facility location problem with two levels of facilities and use two-stage stochastic programming to tackle the issue of uncertainty. We consider a sample average approximation method to estimate the expected cost and employ an accelerated Benders decomposition algorithm to solve the resulting formulation to optimality. An extensive computational study, using 1200 benchmark instances of the problem, demonstrates the efficacy of our improved algorithm. Instances with as many as 20 cheese makers are shown to be solved by our proposed methodology an order of magnitude faster than the automatic Benders decomposition algorithm offered by a commercial solver. Optimal solutions of a real case study with 51 cheese makers together with useful managerial insights are also reported. The value of stochastic solution in the case study signifies the importance of considering the uncertainties that are inherent in the dairy industry. Our analysis of the case study shows that the total expected cost is increased by 28% if such uncertainties are ignored. Furthermore, this increase can become arbitrarily large as the outsourcing costs increase.

Feedback Medicine: Control Systems Concepts in Personalised, Predictive Medicine and Combinatorial Intervention

Abstract: In its broadest definition, systems biology is the application of a `systems' way of thinking about and doing cell biology. By implication, this also invites us to consider a systems approach in the context of medicine and the treatment of disease. In particular, the idea that systems biology can form the basis of a personalised, predictive medicine will require that much closer attention is paid to the analytic properties of the feedback loops which will be set up by a personalised approach to healthcare. To emphasize the role that feedback theory will play in understanding personalised medicine, we use the term feedback medicine to describe the issues this http URL these notes we consider feedback and control systems concepts applied to two important themes in medical systems biology - personalised medicine and combinatorial intervention. In particular, we formulate a feedback control interpretation for the administration of medicine, and relate them to various forms of medical treatment.

To boost or not to boost: Immune activation in HIV infection

Abstract: Various clinical experiments have suggested the significant role of CD4+ T cells activation in viral spread and immune control of HIV infection. In this paper, we use a new mathematical model to explore the intricate interactions among immune activation, CTL response, T cell depletion, and immune escape. It is shown that enhanced immune activation and proliferation of CD4+ T cells, opposite to its beneficial effects in other infections, may facilitate infection and lead to the depletion of CD4+ T cells if effective immune control is not established. By contrast, once effective CTL response to HIV is mounted, the boost of CD4+ T cell response may be beneficial for controlling infection and alleviating immune impairment. Another finding is that immune escape may occur when the infection rate is low, and enhanced activation may prevent the escape if effective immune control can be established. Simulations are provided to illustrate the theoretical analysis.

Phase analysis for 2-D weakly coupled oscillatory systems

Abstract: A phase representation of a two dimensional nonlinear autonomous oscillator is presented. The validity of this representation is argued from the point of view of continuity and a global model is then obtained for a set of coupled oscillators. A brief review of a biological motivated 2 dimensional model for calcium oscillations within a cell is presented as an example of this concepts. A discussion on the results obtained concludes the present work.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Machine learning

Abstract: Machine Learning is the study of methods for programming computers to learn. Computers are applied to a wide range of tasks, and for most of these it is relatively easy for programmers to design and implement the necessary software. However, there are many tasks for which this is difficult or impossible. These can be divided into four general categories. First, there are problems for which there exist no human experts. For example, in modern automated manufacturing facilities, there is a need to predict machine failures before they occur by analyzing sensor readings. Because the machines are new, there are no human experts who can be interviewed by a programmer to provide the knowledge necessary to build a computer system. A machine learning system can study recorded data and subsequent machine failures and learn prediction rules. Second, there are problems where human experts exist, but where they are unable to explain their expertise. This is the case in many perceptual tasks, such as speech recognition, hand-writing recognition, and natural language understanding. Virtually all humans exhibit expert-level abilities on these tasks, but none of them can describe the detailed steps that they follow as they perform them. Fortunately, humans can provide machines with examples of the inputs and correct outputs for these tasks, so machine learning algorithms can learn to map the inputs to the outputs. Third, there are problems where phenomena are changing rapidly. In finance, for example, people would like to predict the future behavior of the stock market, of consumer purchases, or of exchange rates. These behaviors change frequently, so that even if a programmer could construct a good predictive computer program, it would need to be rewritten frequently. A learning program can relieve the programmer of this burden by constantly modifying and tuning a set of learned prediction rules. Fourth, there are applications that need to be customized for each computer user separately. Consider, for example, a program to filter unwanted electronic mail messages. Different users will need different filters. It is unreasonable to expect each user to program his or her own rules, and it is infeasible to provide every user with a software engineer to keep the rules up-to-date. A machine learning system can learn which mail messages the user rejects and maintain the filtering rules automatically. Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis. Statistics focuses on understanding the phenomena that have generated the data, often with the goal of testing different hypotheses about those phenomena. Data mining seeks to find patterns in the data that are understandable by people. Psychological studies of human learning aspire to understand the mechanisms underlying the various learning behaviors exhibited by people (concept learning, skill acquisition, strategy change, etc.).

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Principles of Neural Science

Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Robust adaptive control

Abstract: 1. Introduction. Control System Design Steps. Adaptive Control. A Brief History. 2. Models for Dynamic Systems. Introduction. State-Space Models. Input/Output Models. Plant Parametric Models. Problems. 3. Stability. Introduction. Preliminaries. Input/Output Stability. Lyapunov Stability. Positive Real Functions and Stability. Stability of LTI Feedback System. Problems. 4. On-Line Parameter Estimation. Introduction. Simple Examples. Adaptive Laws with Normalization. Adaptive Laws with Projection. Bilinear Parametric Model. Hybrid Adaptive Laws. Summary of Adaptive Laws. Parameter Convergence Proofs. Problems. 5. Parameter Identifiers and Adaptive Observers. Introduction. Parameter Identifiers. Adaptive Observers. Adaptive Observer with Auxiliary Input. Adaptive Observers for Nonminimal Plant Models. Parameter Convergence Proofs. Problems. 6. Model Reference Adaptive Control. Introduction. Simple Direct MRAC Schemes. MRC for SISO Plants. Direct MRAC with Unnormalized Adaptive Laws. Direct MRAC with Normalized Adaptive Laws. Indirect MRAC. Relaxation of Assumptions in MRAC. Stability Proofs in MRAC Schemes. Problems. 7. Adaptive Pole Placement Control. Introduction. Simple APPC Schemes. PPC: Known Plant Parameters. Indirect APPC Schemes. Hybrid APPC Schemes. Stabilizability Issues and Modified APPC. Stability Proofs. Problems. 8. Robust Adaptive Laws. Introduction. Plant Uncertainties and Robust Control. Instability Phenomena in Adaptive Systems. Modifications for Robustness: Simple Examples. Robust Adaptive Laws. Summary of Robust Adaptive Laws. Problems. 9. Robust Adaptive Control Schemes. Introduction. Robust Identifiers and Adaptive Observers. Robust MRAC. Performance Improvement of MRAC. Robust APPC Schemes. Adaptive Control of LTV Plants. Adaptive Control for Multivariable Plants. Stability Proofs of Robust MRAC Schemes. Stability Proofs of Robust APPC Schemes. Problems. Appendices. Swapping Lemmas. Optimization Techniques. Bibliography. Index. License Agreement and Limited Warranty.