Marc Salomon – författare

The history of ecology will also be addressed to explain the development of the field of ecology and its relationship to human activities and ways of thinking since prehistorical time until the present.

Ecology is traditionally presented as a science explaining a highly diverse range of subjects, for example the biogeochemical cycle of oxygen or the structure of species communities. We also tend to incorporate into ecology environmental degradation inflicted by human activities directly or indirectly upon natural systems and the attempts to prevent or mitigate these destructive trends. While fundamental ecology is a broad scientific discipline dealing  with ecosystems through a diverse number of approaches, applied ecology is more a philosophy and body of practices with a focus on society and politics. Applied ecology uses concepts used in fundamental ecology. Although the topics of fundamental ecology appear disconnected, it is often felt that they belong to the same field. This book will focus predominately on fundamental ecology. It comprises different sections arranged in a logical and linear architecture for the reader to follow. The chapters, though, are neatly interlinked to create an explanatory system reflecting the systemic nature of ecology.As even distinguished scientists are uncertain about the scientific character of ecology, it is important to explain rationally why these subjects are all topics of the same discipline, which epistemologically can be proven to be an actual science. As such ecology needs to define its scope and “meta-theory”, a system of interrelated consistent theories uniting many studies regarded empirically as different fields. In this regard, this textbook presents an integrative vision of ecology. The history of ecology will also be addressed to explain the development of the field of ecology and its relationship to human activities and ways of thinking since prehistorical time until the present. In addition, the book presents a typology of the interactions within the biocoenoses, separating trophic relationships from other types of interactions (coevolution, competition, mineralisation), and presents a reflection on the interactions with the abiotic system. This book shows that ecology must be viewed as an integrated system to explain the immensely complex reality of ecosystems in the simplest way possible.

The deterministic lotsizing problems considered in this book deal with determining minimal cost production schedules and inventory replenishment strategies, such that (known) market demand is fulfilled satisfactorily, while capacity restrictions on production resources are not violated. The author gives researchers and interested practitioners a review and comparison of mathematical model formulations and solution procedures for the deterministic lotsizing problem. The relevance of lotsizing procedures within modern production planning systems, such as MRP, JIT and OPT, is discussed. A novel class of model formulations is introduced in which lotsizing and production sequencing aspects are considered simultaneously. Several variants of practical relevance are analysed, including the case of parallel machine production lines, sequence dependent setup costs, and nontrivial machine setup times. A literature review is given for multilevel lotsizing problems, and model formulations and solution procedures are discussed. New heuristic procedures are presented that rely on mathematical programming techniques and statistical search techniques such as simulated annealing and table search.The results of a computational com- parison between the various solution procedures on a large set of problems are discussed.

In diesem Band werden zentrale Themen und neuere Entwicklungstendenzen auf dem Gebiet des Operations Research (OR) behandelt. Gegenstand sind die Vortrage, die anlasslich der 22. Jahrestagung der Deutschen Gesellschaft fur Operations Research (DGOR) und der Nederlandse Stichting voor Operations Research (NSOR) in der Zeit vom 25.-27.8.1993 an der Freien Universitat von Amsterdam gehalten wurden. Das Buch ermoglicht dem Leser einen Einblick in neueste Forschungsergebnisse auf dem Gebiet des Operations Research. Neben primar methodischen Fragestellungen bilden praxisorientierte Themen, wie z.B. Anwendungsberichte aus der Praxis und der Bereich Produktionsplanung und -steuerung, einen Schwerpunkt in diesem Band.

This thesis deals with timing and sizing decisions for production lots, and more precisely, with mathematical models to support optimal tim­ ing and sizing decisions. These models are called lotsizing models. They are characterized by the fact that production lots are determined based on a trade-offbetween production costs and customer service. Production costs can be categorized as basic production costs, which consist of material costs, labour costs, machine startup costs and over­ head costs, and inventory related costs, which include costs of capital tied up in inventory, insurances and taxes. Customer service is the capability of the firm to deliver to their clients the products in the quantity they ordered at the agreed upon time and place. The costs of realizing a certain service level are usuaIly very dif­ ficult to convert into money. They include costs of expediting, loss of customer goodwill, and loss of sales revenues resulting from the short­ age situation.