Reachable Sets Approach to Multiobjective Problems and its Possible Applications to Water Resources Management in the Skane Region

Decision making in a lot of resources supply and resources allocation problems is related to sophisticated multiobjective analysis. The concept of a man-computer simulation system was suggested as a tool for decision making in problems of this kind, especially in the case of water resources (Moiseev et al. 1980). Within the framework of such a system the analyst and the expert employ a full range of operational research methods (simulation, optimization, multiobjective, informal and game-theoretical ones) to address multiobjective problems by means of the hierarchical system of mathematical models of the system under study. Various forms of mathematical models can be studied by means of simulation experiments. To establish control variables (to formulate scenarios) in a simulation study the expert may use optimization techniques applied to models simpler than the simulation ones. It is reasonable to study the problem of criteria formulation in optimization problems (the objectives convolution problem) by means of multiobjective techniques and simple (screening) models. The multiobjective study is the most important part of investigation based on the simulation system, because it is the multiobjective investigation that gives a general understanding of the system under study. This paper treats a new approach to multiobjective problems investigation. This approach is called the Generalized Reachable Sets (GRS) approach and belongs to generating multiobjective methods (Cohon 1978). It employs an explicit representation of a set of all reachable objective values. In contrast to different generating multiobjective methods, the mathematical background of the GRS approach is the linear inequalities techniques. This approach is used now at the Computing Center of the USSR Academy of Sciences in various tasks. The structure of the paper is as follows: first the mathematical background of the approach is outlined, and then possible applications of the approach to the Skane water resources management are discussed

On Municipal Water Pricing Practices in the Southwestern Skane Region, Sweden

Water resource systems have been an important part of resources and environment related research at IIASA since its inception. As demands for water increase relative to supply, the intensity and efficiency of water resource management must be developed further. This in turn requires an increase in the degree of detail and sophistication of the analysis, including economic, social and environmental evaluation of water resources development alternatives aided by application of mathematical modeling techniques, to generate inputs for planning, design, and operational decisions. This paper was written as part of a collaborative study on water resources problems in Southwestern Skane, Sweden, pursued by IIASA in collaboration with the Swedish National Environmental Protection Board and the University of Lund, and completed in 1982. The purpose of this paper was to examine the municipal water pricing system as it now exists in Skane and to compare it with the two-part tariff system. The paper discusses the important relationship between the water pricing system and sudden shifts in municipal water demand

Application of the Generalized Reachable Sets Method to Water Resources Problems in the Southern Peel Region of the Netherlands

This research was carried out as a part of investigations undertaken by the IIASA on the methods and procedures that can assist the design of policies aimed at providing for the rational use of water and related resources taking into account economic, environmental and institutional aspects. One of the case studies which was used for testing these methods is the problem of application of water in agricultural production in the Southern Peel region of the Netherlands. Here we apply to the investigation of water problems of the region under study a new approach -- the generalized reachable sets (GRS) method. This approach makes it possible to present the information contained in a model implicitly in an aggregated explicit form. Within the framework of decision support systems the GRS approach can be applied for analysis of simplified models on screening stage of investigation. The method allows us to describe the set of all indicator values which are reachable (accessible) under feasible alternatives

Influence of Heat Treatment Mode of Various Magnesia Rocks on their Properties

Investigations of the changes of structure, specific surface and true density of following high-magnesia rocks at heat treatment have been performed: brucite rocks, magnesite, hydromagnesia rocks, amorphous magnesite. It has been revealed that to obtain chemically active magnesium oxide, which is used for synthesis of high-refractory materials and obtaining magnesia binder, it is necessary to burn at low or moderate temperatures in the temperature range of 500-800 °С. Increase of temperature more than 800 °С leads to obtaining densely sintered cubic magnesium oxide with the periclase structure

Global Models, The Biospheric Approach (Theory of the Noosphere)

The problem of the coevolution of mankind and the biosphere, i.e., the relationship between the process of the evolution of the biosphere and the evolution of human activity which provides a homeostasis for human civilization, has become one of the principal problems of human ecology. The first step in an extensive program of interdisciplinary research is the creation of a system of mathematical models which would serve as a framework for planning international research programs. The research described herein has two stages. The first stage, a still primitive system of models was constructed and analyzed, using systems dynamics techniques. This system of models, outlined in the second section of the paper, has already helped the authors in their contacts with experts in biology, soil science, etc., and the creation of an information base has in essence, turned into a discussion of plans for future work. Studies connected with simulating the evolution of the biosphere were developed in three directions: simulation of processes of a biotic nature, simulation of climate, and simulation of human activity. Experimental results obtained using this system in the "if...then" mode, may be helpful for understanding, at least on a qualitative basis, possible impacts of human activity on the evolution of the biosphere assuming that the present day trends remain unchanged. This system of models is at present programmed at IIASA and is ready to be used for simulation experiments. The second step in the research is based on an understanding of the fact that the systems dynamic approach is not sufficient for the elaboration and study of the system of models which describes human activity. Furthermore, it is necessary to analyze and coordinate models developed by experts in varied branches of science -- biologists, climatologists, economists, etc. Thus, it is necessary to elaborate new mathematical techniques that can be used in the investigation of global coevolution problems. Some principles for the development of these techniques were formulated at the Computing Center of the USSR Academy of Sciences and are presented herein. The three main principles are: (1) Linear parametrization of comprehensive submodels; (2) Models of human activity are split into two levels -- the decision-making level and the technological level -- and a description of the system of models at the technological level only; (3) Analysis and coordination of the system of models by constructing a set of all reachable values of performance indices (The Generalized Reachable Sets Approach). The linear parametrization procedure for a climate model which is essentially the Mintz-Arakawa global atmospheric circulation model as described by Gates et al. (1971) and modified to account for the climatic trends due to the influence of anthropogenic factors, is described in the third section of the paper. The problems of modeling human activity and the main features of the Generalized Reachable Sets approach, as well as the general scheme of analysis of global biospheric models, are presented in the fourth section of the paper. This work, which is now in the early stages, calls for a great deal of scientific effort over a long period of time. The authors anticipate that the importance of the research in this direction will be internationally recognized and supported

Influence of Heat Treatment Mode of Various Magnesia Rocks on their Properties

AbstractInvestigations of the changes of structure, specific surface and true density of following high-magnesia rocks at heat treatment have been performed: brucite rocks, magnesite, hydromagnesia rocks, amorphous magnesite. It has been revealed that to obtain chemically active magnesium oxide, which is used for synthesis of high-refractory materials and obtaining magnesia binder, it is necessary to burn at low or moderate temperatures in the temperature range of 500-800°C. Increase of temperature more than 800°C leads to obtaining densely sintered cubic magnesium oxide with the periclase structure