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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.

Linear and nonlinear waves, by G. B. Whitham. Pp.636. £50. 1999. ISBN 0 471 35942 4 (Wiley).

Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

This paper addresses the problem of state and fault estimation for linear continuous-time systems with actuator failures. A new estimation technique is presented to deal with this design problem. In the proposed approaches, the original system is first augmented in a descriptor system, and a new sliding mode observer is introduced to obtain accurate estimations of both system states and actuator faults. A numerical example is presented to illustrate the effectiveness and applicability of the proposed technique.

http://ieeexplore.ieee.org/iel5/6373891/6389889/06390867.pdf

Fault estimation for linear continuous-time systems with actuator failures

The micro-vibrations generated by mechanical systems onboard spacecraft can affect the performance of instruments with high pointing accuracy and stability. This paper provides a micro-vibration generating control system based on Real Time Application Interface (RTAI), a real time Linux extension, for ground tests purposes. The vibration generating control algorithm is filtered-X adaptive inverse control method. A voice coil actuator is used in the vibration generating experiments. The experiments show that the system can generate different frequency precision sine vibration whose error is less than 2 mg which is in environmental and electrical noise level.

A Real-time Linux based controller for micro-vibration generating with voice coil actuator

The original version of the article was published in Central European Journal of Engineering 3, 67–79 (2013), DOI: 10.2478/s13531-012-0032-2. Unfortunately, the original version of this article contains a mistake in Figure 17. Here we display the corrected version of this figure.

/pdf/erratum-to-a-fuzzy-logic-approach-to-modeling-a-vehicle-2um1pjc9w6.pdf

Erratum to “A fuzzy logic approach to modeling a vehicle crash test” by W. Pawlus, H. Reza, K. G. Robbersmyr

In this paper, we propose a method for designing continuous gain-scheduled robust H ∞ observer on a class of extended stochastic nonlinear systems subject to time delay and actuator saturation. Initially, gradient linearization procedure is applied to describe such extended nonlinear systems into several model-based linear systems. Next, a robust linear H ∞ observer is designed to such linear stochastic models. Subsequently, a convex hull set is investigated and sufficient condition is derived in terms of feedback observer to determine whether a given initial condition belongs to an ellipsoid invariant set. Finally, continuous gain-scheduled approach is employed to design continuous nonlinear observers on the entire extended nonlinear jump system. A simulation example is given to illustrate the effectiveness of developed techniques.

Hamid Reza Karimi

Papers

Fault estimation for linear continuous-time systems with actuator failures

A Real-time Linux based controller for micro-vibration generating with voice coil actuator

Erratum to “A fuzzy logic approach to modeling a vehicle crash test” by W. Pawlus, H. Reza, K. G. Robbersmyr

Gain-scheduled H-infinity observer design for nonlinear stochastic systems with time-delay and actuator saturation

Hybrid robust-stochastic energy scheduling of multi-carrier systems integrated with ice storage and heat storage systems: A multi-solver approach