Considerations for Rapidly Converging Genetic Algorithms Designed for Application to Problems with Expensive Evaluation Functions

A genetic algorithm is a technique designed to search large problem spaces using the Darwinian concepts of evolution. Solution representations are treated as living organisms. The procedure attempts to evolve increasingly superior solutions. As in natural genetics, however, there is no guarantee that the optimum organism will be produced. One of the problems in producing optimal organisms in a genetic algorithm is the difficulty of premature convergence. Premature convergence occurs when the organisms converge in similarity to a pattern which is sub-optimal, but insufficient genetic material is present to continue the search beyond this sub-optimal level, called a local maximum. The prevention of premature convergence of the organisms is crucial to the success of most genetic algorithms. In order to prevent such convergence, numerous operators have been developed and refined. All such operators, however, rely on the property of the underlying problem that the evaluation of individuals is a computationally inexpensive process. In this paper, the design of genetic algorithms which intentionally converge rapidly is addressed. The design considerations are outlined, and the concept is applied to an NP-Complete problem, known as a Crozzle, which does not have an inexpensive evaluation function. This property would normally make the Crozzle unsuitable for processing by a genetic algorithm. It is shown that a rapidly converging genetic algorithm can successfully reduce the effective complexity of the problem

Georges Perec's Geographies: Material, Performative and Textual Spaces

Georges Perec, novelist, filmmaker and essayist, was one of the most inventive and original writers of the twentieth century. A fascinating aspect of his work is its intrinsically geographical nature. With major projects on space and place, Perec’s writing speaks to a variety of geographical, urban and architectural concerns, both in a substantive way, including a focus on cities, streets, homes and apartments, and in a methodological way, experimenting with methods of urban exploration and observation, classification, enumeration and taxonomy. Georges Perec’s Geographies is the first book to offer a rounded picture of Perec’s geographical interests. Divided into two parts, Part I, Perec’s Geographies, explores the geographies within Perec’s work in film, literature and radio, from descriptions of streets to the spaces of his texts, while Part II, Perecquian Geographies, explores geographies in a range of material and metaphorical forms, including photographic essays, soundscapes, theatre, dance and writing, created by those directly inspired by Perec. Georges Perec’s Geographies extends the body of Perec criticism beyond Literary and French Studies to disciplines including Geography, Urban Studies, Planning and Architecture to offer a complete and systematic examination of Georges Perec’s geographies. The diversity of readings and approaches will be of interest not only to Perec readers and fans but to students and researchers across these subjects