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This paper provides a self-contained introduction to the mathematical aspects of the topological derivative.

Full justifications are given on simple model problems following a modern approach based on the averaged adjoint state technique. Extensions are discussed in relation with the literature on the field.

Closed expressions of topological derivatives are obtained and commented.

Several cases are covered in a unified and didactic presentation. Some elements of proof are novel.

The purpose of this paper is to compare between two methods of volume control in the context of topological derivative-based structural optimization of Kirchhoff plates.

The compliance topology optimization of Kirchhoff plates subjected to volume constraint is considered. In order to impose the volume constraint, two methods are presented. The first one is done by means of a linear penalization method. In this case, the penalty parameter is the coefficient of a linear term used to control the amount of material to be removed. The second approach is based on the Augmented Lagrangian method which has both, linear and quadratic terms. The coefficient of the quadratic part controls the Lagrange multiplier update of the linear part. The associated topological sensitivity is used to devise a structural design algorithm based on the topological derivative and a level-set domain representation method. Finally, some numerical experiments are presented allowing for a comparative analysis between the two methods of volume control from a qualitative point of view.

The linear penalization method does not provide direct control over the required volume fraction. In contrast, through the Augmented Lagrangian method it is possible to specify the final amount of material in the optimized structure.

A strictly simple topology design algorithm is devised and used in the context of compliance structural optimization of Kirchhoff plates under volume constraint. The proposed computational framework is quite general and can be applied in different engineering problems.

The purpose of this paper is to assess the issues faced by managers of inland waterways in the Southeastern USA as a guide for improvements to spill management information systems.

A survey was administered to a group of over 300 professionals representing multiple organizations involved in water quality management and/or spill response in the Southeast region of the USA to query their perceptions on leading demands and issues faced in management of inland waterways both on a daily basis and during spill response efforts.

Survey results indicated that communication is often the “weak link” in both water management and spill response activities, and that enhanced spill management information tools could serve as a valuable resource in addressing this problem. Display of spatial/visual information was deemed to be especially important to spill response personnel and should be included in the next generation of spill response systems.

The scope is limited to the Southeastern USA, but similar results would be expected in other regions where management of surface water is of concern.

In these trying economic times, the survey results serve to rank order decision‐support priorities to which available resources should be allocated and indicate areas of interest for improved support in both water resource management and spill response.

The paper provides the first documentation of the demands and decision‐support priorities of inland waterway resource managers and spill response personnel.

Introduction Operations research, i.e. the application of scientific methodology to operational problems in the search for improved understanding and control, can be said to have started with the application of mathematical tools to military problems of supply bombing and strategy, during the Second World War. Post‐war these tools were applied to business problems, particularly production scheduling, inventory control and physical distribution because of the acute shortages of goods and the numerical aspects of these problems.

THE writer well remembers the interest and enthusiasm with which he received, on its publication, a copy of the first of a series of class lists, issued many years ago by the Public Library of Clerkenwell, under the librarianship of Mr. James Duff Brown. They were admirably compiled and contained several novel features, which made them a type destined to be extensively imitated elsewhere. Now comes from Islington, under the same capable editorship, a catalogue more fundamentally novel, so far at least as Public Library catalogues are concerned, than the class lists above referred to, and destined without question to be far more widely followed, as its advantages and value become generally appreciated. This is—to quote the secondary title—“A classified list of the best books on all subjects in the central, north, and west libraries,” i.e. a select catalogue.

The purpose of this work is to present a procedure for determining the wind drift factor through two-dimensional computational fluid dynamics (CFD) simulations of the wind acting on a wavy sea surface, such that the subjectivity of its estimation is reduced.

The wind drift factor was determined by two-dimensional CFD analyses with open-channel condition. The characteristic wave was determined by the Sverdrup–Munk–Bretschneider (SMB) method. The uncertainty analysis is based on convergence studies using a single parameter refinement (grid and time step).

This procedure allows the estimation of the wind drift factor in a fetch-limited domain. The domain's value in the analyzed region is 0.0519 ± 4.92% which is consistent with the upper values of the wind drift factors reported in the literature.

The use of a three-dimensional domain was impractical with the available computational resources because of the fine mesh required for wave modeling. The uncertainty analysis consisted only of a verification procedure. Validation against real data was not possible because of the lack of measured data in the analyzed region.

The wind drift factor is usually estimated based on either experience or random sampling. The original contribution of this work is the presentation of a CFD procedure for estimating the wind drift factor, in which the domain inlet is subjected to a wave boundary condition and to a wind velocity.