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 …

I and i

In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Forecasting, Structural Time Series Models and the Kalman Filter

Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

Most of the signal processing that we will study in this course involves local operations on a signal, namely transforming the signal by applying linear combinations of values in the neighborhood of each sample point. You are familiar with such operations from Calculus, namely, taking derivatives and you are also familiar with this from optics namely blurring a signal. We will be looking at sampled signals only. Let's start with a few basic examples. Local difference Suppose we have a 1D image and we take the local difference of intensities, DI(x) = 1 2 (I(x + 1) − I(x − 1)) which give a discrete approximation to a partial derivative. (We compute this for each x in the image.) What is the effect of such a transformation? One key idea is that such a derivative would be useful for marking positions where the intensity changes. Such a change is called an edge. It is important to detect edges in images because they often mark locations at which object properties change. These can include changes in illumination along a surface due to a shadow boundary, or a material (pigment) change, or a change in depth as when one object ends and another begins. The computational problem of finding intensity edges in images is called edge detection. We could look for positions at which DI(x) has a large negative or positive value. Large positive values indicate an edge that goes from low to high intensity, and large negative values indicate an edge that goes from high to low intensity. Example Suppose the image consists of a single (slightly sloped) edge:

http://ieeexplore.ieee.org/iel5/5/31307/01456462.pdf

Linear systems

Thermophysical Properties Research Literature Retrieval Guide Edited by Y. S. Touloukian, J. K. Gerritsen and N. Y. Moore Second edition, revised and expanded. Book 1: Pp. xxi + 819. Book 2: Pp.621. Book 3: Pp. ix + 1315. (New York: Plenum Press, 1967.) n.p.

/pdf/heat-and-mass-transfer-1yaijfx8vp.pdf

Heat and Mass Transfer

A method for electromagnetic shunt damping (EMSD) is presented in this paper. Compared to piezoelectric shunt damping, the proposed EMSD vibration controller has a number of benefits. It requires small shunt voltages, can provide large stroke and can dampen larger mechanical structures. A passive control strategy is validated through experimentation on a simple electromagnetic mass-spring-damper system. Theoretical results are also presented.

/pdf/electromagnetic-shunt-damping-wz60a82wb3.pdf

Electromagnetic shunt damping

Piezoelectric tube scanners are widely used in scanning probe microscopes to position the sample or the probe. Fast and accurate scanning requires the suppression of dominant low-frequency resonances as well as the compensation of dynamics-coupling effects. The present article gives a detailed description of the fully coupled tube scanner dynamics over a wide frequency range modeled by finite element (FE) analysis using the commercially available software package ANSYS. The effect of a sample mass attached to the top of the tube is investigated by considering its added mass and local stiffening. A model order reduction scheme is applied to obtain a low order model that describes the lateral and vertical deflections as well as the voltage induced on quadrant electrodes. Comparison to experimental data demonstrates a good agreement for both the full FE model and reduced order model.

/pdf/simulation-of-dynamics-coupling-in-piezoelectric-tube-4se49b454m.pdf

Simulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element analysis.

In this paper we demonstrate the implementation of model predictive control (MPC) for vibration suppression of the first five bending modes of an active structure. For adequate performance, this requires a 5kHz sampling rate, which is achieved using a standard active-set optimisation technique running on a 200MHz digital signal processor. Experimental results show that MPC offers improved performance for this application when compared with other standard approaches.

/pdf/application-of-mpc-to-an-active-structure-using-sampling-32p111t13s.pdf

Application of MPC to an active structure using sampling rates up to 25kHz

This paper presents a new type of passive vibration control: adaptive electromagnetic shunt damping. We propose a single-mode resonant shunt controller that adapts to environmental conditions using two different adaptation strategies. The first technique is based on minimizing the root mean square (RMS) vibration, while the second minimizes the phase difference between two measurable signals. An experimental comparison shows that relative phase adaptation performs better than the RMS technique.

/pdf/adaptive-electromagnetic-shunt-damping-1az3xdqv9d.pdf

Adaptive electromagnetic shunt damping

In this paper, we describe the design of a flexure guided, two-axis nanopositioner driven by piezoelectric stack actuators. The scanner is specifically designed for high-speed scanning probe microscope (SPM) applications. A high-speed atomic force microscope (AFM) is required to acquire high resolution, three-dimensional, time-lapse images of fast processes such as the rapid movement of cells and the diffusion of DNA molecules. High-speed scanner designs have been proposed, for example, by Ando and co-workers as well as Schitter and coworkers, for AFM imaging. In the proposed design, the slow and fast scanning axes are serially connected and both axes are flexure-guided to minimize runout. The achievable scan range is 10 x 10 mum. The scanner's mechanical resonance frequencies were optimized using finite element analysis. Experimental results show a first major resonance, in the slow and fast axis respectively, at approximately 1.5 kHz and 29 kHz. In addition to evaluating the proposed design, this paper also discusses the various tradeoffs between speed, range, and required control hardware. Electrical requirements and scan trajectory design are also considered.

/pdf/high-speed-serial-kinematic-afm-scanner-design-and-drive-42t7fd1mpt.pdf

Andrew J. Fleming

Papers

Electromagnetic shunt damping

Simulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element analysis.

Application of MPC to an active structure using sampling rates up to 25kHz

Adaptive electromagnetic shunt damping

High-speed serial-kinematic AFM scanner: Design and drive considerations