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The momentum theory of the wind turbine, as usually stated, does not allow interference factors greater than one‐half, although experiment shows that values approaching unity are possible. The theory is extended to remove this contradiction, and the assumptions are at the same time slightly generalized.

THE thirty‐eighth annual Exhibition of the Physical Society was held at the Imperial College, South Kensington, on April 8–13, and the account which follows describes a few of the items shown, which have been selected because of their more direct interest for the aeronautical engineering profession.

The attractiveness of functionally graded composites lies in the possibility of a gradual spatial change of their properties such as hardness, strength and wear resistance. The purpose of this paper is to discuss the use of electromagnetic buoyancy to separate the reinforcement particles during the casting process of such a composite.

The basic problem encountered in the process of casting composites is to obtain electromagnetic buoyancy and simultaneously to avoid a flow of the liquid metal which destroys the desired composite structure. In this paper the authors present the methodology of numerical optimization of inductor geometry in order to homogenize the electromagnetic force field distribution.

The optimization method based on searching the solution subspace created by applying knowledge of the modelled process physics proved better than the universal local optimization methods. These results were probably caused by the complex shape of the criterion function hypersurface characterized by the presence of local minima.

Due to their characteristics, functionally graded composites are of great interest to the automotive, aerospace and defense industries. In the case of metal matrix composites casting techniques (as the presented one) are the most effective methods of producing functionally graded materials.

The paper presents the optimization of a new process of casting functionally graded composites in a low-frequency alternating electromagnetic field. The process involves problems that did not occur previously in the area of electromagnetic processing of materials. The paper proposes the use of special design of inductors to homogenize the electromagnetic force field.

A multicomputer implementation of a circuit optimization program is presented. The program, called COCO, is tailored for the design problems encountered when the large signal dynamic response of VLSI circuits is to be optimized. The optimization part of the program runs on a host computer and controls the action of a concurrent circuit simulation program running on a multicomputer. Thus, when run on a parallel computer, COCO is able to exploit concurrency during the simulation phase.

This paper aims to develop an efficient two‐variable minimisation algorithm and to apply it in engineering optimisation of buttonhole reinforcements.

An iterative extreme search is based on quadratic approximation of objective function, locating approximate solution at the minimum of corresponding elliptic paraboloid. Stress analysis is performed using plane stress finite element model. Optimal selection of geometrical parameters of buttonhole‐type reinforcement is done in terms of balance between maximum stress and material consumption.

Adopted minimisation algorithm is assessed in a selected test example and proven to perform well in comparison with methods available in literature. In the selected case two local minima have been found within the predefined optimisation domain, with slight difference in objective function values.

Research is limited to homogeneous isotropic elastic model and a single representative load case. Objective function is restricted to two influence factors and predefined optimisation domain.

The method can be useful for engineers/practitioners in the branch of clothing technology as a tool for computational estimate of optimal design of structural reinforcements.

The main quality of the paper is in software fusion of finite element analysis and advanced optimisation algorithm. The proposed theoretical‐numerical model is discussed in terms of applicability in parameter setting on buttonholer in garment production.

The attempt to understand the working of the brain suffers from difficulties of definition, since it is not clear that brains can understand brains, and the nature of “understanding” is essentially subjective. If it is accepted that our thought processes are products of evolution, the principles of rational discourse and science are reflections of the environment rather than inherent in us. Nevertheless they are strongly ingrained and well‐founded, but since their implications are essentially subjective they cannot be distinguished from other assertions that would be classed as “mystical”.

Considers the central nervous system as a data‐processing system, in which one can model (simulate) an operating system, a knowledge processor, a monitor, a model of the Universe and a linguistic model. Artistic creativity is compared with scientific activity and it is stressed that scientific creativity can also mean small advances in given areas. Considers it essential not to propose new paradigms, but to elaborate efficient imaginary ideas, to create new concepts and to propose new areas of research. In these directions, some simple methods are suggested.

The purpose of this paper is to measure the financial risk and optimal capital structure of a corporation.

Irregular disjunctive programming problems arising in firm models and risk management can be solved by the techniques presented in the paper.

Parallel processing and mathematical modeling provide a fruitful basis for solving ultra-scale non-convex general disjunctive programming (GDP) problems, where the computational challenge in direct mixed-integer non-linear programming (MINLP) formulations or single processor algorithms would be insurmountable.

The test is limited to a single firm in an experimental setting. Repeating the test on large sample of firms in future research will indicate the general validity of Monte-Carlo-based VAR estimation.

The authors show that the risk surface of the firm can be approximated by integrated use of accounting logic, corporate finance, mathematical programming, stochastic simulation and parallel processing.

Parallel processing has potential to simplify large-scale MINLP and GDP problems with non-convex, multi-modal and discontinuous parameter generating functions and to solve them faster and more reliably than conventional approaches on single processors.

A simple algebraic test applied to a specially constructed constant matrix is developed to test the semi‐definiteness property of symmetric functional matrices. The simplicity of the algebraic test makes it very suitable for computer implementation. The results are applied in the analysis of a class of nonlinear time‐varying singular RC networks. Robustness of the boundedness property of network response with respect to resistive elements is shown.

This paper offers various state‐space representations in the context of applications of the system control theory to dynamic economic systems and examines interrelationships between the alternative representations in both economics literature and system control engineering literature. In particular, some characteristics of various state‐space forms are assessed with respect to the structural properties of each form, thereby demonstrating the relative advantages and disadvantages of different realization methods presented in this paper.