- Email: [email protected]
An icelandic fisheries model
Mathematical and Computer Mode&g
Reports
the tactical situations that can develop between two opposing submarines. The kernel of the program suite is the Submarine Interactive Attack Model (SIAM). This is sufficiently versatile that a wide range of scenarios can be simulated, and meaningful statistics for expected submarine performance obtained. Emphasis is placed on the modelling of both the dynamic tactical situations that can evolve in underwater warfare and the tactical decision-making that influences the outcome of submarine operations. Although the techniques have been applied to a specific domain it is believed that they are applicable to a wide range of complex problems. Key words-Artificial
J. marh. Bd.
intelligence, defence studies, modelhng, simulation
Vol.26.pp. 73-92.1988
J SEPARABLE
MODELS FOR AGE-STRUCTURED POPULATION GENETICS MARCELOVIDIU
VLAD
Bucuresti, Casuta postala 77-49, R.S. Romania Abstract-This paper is concerned with the applications of nonlinear age-dependent dynamics to population genetics. Age-structured models are formulated for a single autosomal locus with an arbitrary number of alleles. The following cases are considered: (a) haploid populations with selection and mutation; (b) monoecious diploid populations with or without mutation reproducing by self-fertilization of by two types of random mating. The diploid models do not deal with selection. For these cases the genie and genotypic frequencies evolve towards time-persistent forms, whether the total population size tends towards exponential growth or not. Key words-Age-dependence.
J. Policy Modeling
Vol. 9. No. 3, pp. 437453,
MODELING
separable models, population genetics
1987
HIGH LEVELS OF DEFENSE A VIETNAM
EXPENDITURES:
DOUGLASLEE’ and HERMANSTEKLER* ‘Data Resources Inc. and %dustrial College of the Armed Forces, National Defense University, Washington, DC 20319-6000, U.S.A. Abstract-This paper analyzes the behavior of the U.S. economy when the share of GNP devoted to defense is similar to that occurred during the Vietnam War period. The main problem considered was: How to model and evaluate the economic impact of a future Vietnam-like conflict. The Vietnam “increment” was estimated, and these estimates were added to a base-case simulation to analyze the economic effects.
Eur. J. opl Res. Vol. 33. pp. 191-199, 1988
AN ICELANDIC
FISHERIES
MODEL
THORKELL HELGA~~Nand SNJ~LFUR~LAFSSON Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland Abstract-A model has been developed for the Ministry of Fisheries in Iceland which is being used as a decision support tool in fisheries management. With this model predictions can be made about catches of cod and other demersal species several years ahead. Furthermore earnings and costs in the fisheries are calculated. The starting point is the size of the fish stocks in the beginning of the planning period together with the size and classification of the fishing fleet. Changes in the fleet composition are among M.C.M. 12,8-I
1049
1050
Mathematical
and Computer
Modelling
Reports
the control variables. Emphases are on details such as geographical distribution of the catches. The model is used by the Ministry, both in short term management regarding quota systems and for long term investment planning. Results suggest that in the long run the fishing fleet is now far too big. Parameters for the model are obtained from an intensive data base on catches of every boat for every month in the last decade, disaggregated by species and landing harbour. Parallel to this model and a new method of stock size estimation was developed. The current model was preceded by an optimization model which was not politically accepted! The paper touches on the problems of technical consultation on a sensitive political issue. Key words-Decision
support
systems,
fisheries management,
government,
modelling,
planning
Eur.J. opl Rex Vol. 33, pp. 212-222,1988
A COMPREHENSIVE ENERGY MODEL IN THE MUNICIPAL ENERGY PLANNING PROCESS CLAS-OTTO WENE and Bo RYDBN
Energy
Systems
Technology,
Department of Energy Conversion, Chalmers S-412 96 Gothenburg, Sweden
University
of Technology,
Abstract-Based on several years of experience, the procedural aspects of the use of a comprehensive LP-model for community energy planning is discussed. The community energy system is seen as a technically complex, open system which is managed by a network of organizations (esoteric boxes). Technical complexity, closure and lack of unique management raises specific procedural problems for which solutions are suggested. The network management gives the comprehensive model a special role in the planning process is providing for improved information flows and the conflict resolution. The viability of the paradigm of learning is noted. A methodology to merge substantive and procedural aspects is proposed. Key words-Energy,
planning,
urban
affairs,
learning,
optimization
Reports
the tactical situations that can develop between two opposing submarines. The kernel of the program suite is the Submarine Interactive Attack Model (SIAM). This is sufficiently versatile that a wide range of scenarios can be simulated, and meaningful statistics for expected submarine performance obtained. Emphasis is placed on the modelling of both the dynamic tactical situations that can evolve in underwater warfare and the tactical decision-making that influences the outcome of submarine operations. Although the techniques have been applied to a specific domain it is believed that they are applicable to a wide range of complex problems. Key words-Artificial
J. marh. Bd.
intelligence, defence studies, modelhng, simulation
Vol.26.pp. 73-92.1988
J SEPARABLE
MODELS FOR AGE-STRUCTURED POPULATION GENETICS MARCELOVIDIU
VLAD
Bucuresti, Casuta postala 77-49, R.S. Romania Abstract-This paper is concerned with the applications of nonlinear age-dependent dynamics to population genetics. Age-structured models are formulated for a single autosomal locus with an arbitrary number of alleles. The following cases are considered: (a) haploid populations with selection and mutation; (b) monoecious diploid populations with or without mutation reproducing by self-fertilization of by two types of random mating. The diploid models do not deal with selection. For these cases the genie and genotypic frequencies evolve towards time-persistent forms, whether the total population size tends towards exponential growth or not. Key words-Age-dependence.
J. Policy Modeling
Vol. 9. No. 3, pp. 437453,
MODELING
separable models, population genetics
1987
HIGH LEVELS OF DEFENSE A VIETNAM
EXPENDITURES:
DOUGLASLEE’ and HERMANSTEKLER* ‘Data Resources Inc. and %dustrial College of the Armed Forces, National Defense University, Washington, DC 20319-6000, U.S.A. Abstract-This paper analyzes the behavior of the U.S. economy when the share of GNP devoted to defense is similar to that occurred during the Vietnam War period. The main problem considered was: How to model and evaluate the economic impact of a future Vietnam-like conflict. The Vietnam “increment” was estimated, and these estimates were added to a base-case simulation to analyze the economic effects.
Eur. J. opl Res. Vol. 33. pp. 191-199, 1988
AN ICELANDIC
FISHERIES
MODEL
THORKELL HELGA~~Nand SNJ~LFUR~LAFSSON Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland Abstract-A model has been developed for the Ministry of Fisheries in Iceland which is being used as a decision support tool in fisheries management. With this model predictions can be made about catches of cod and other demersal species several years ahead. Furthermore earnings and costs in the fisheries are calculated. The starting point is the size of the fish stocks in the beginning of the planning period together with the size and classification of the fishing fleet. Changes in the fleet composition are among M.C.M. 12,8-I
1049
1050
Mathematical
and Computer
Modelling
Reports
the control variables. Emphases are on details such as geographical distribution of the catches. The model is used by the Ministry, both in short term management regarding quota systems and for long term investment planning. Results suggest that in the long run the fishing fleet is now far too big. Parameters for the model are obtained from an intensive data base on catches of every boat for every month in the last decade, disaggregated by species and landing harbour. Parallel to this model and a new method of stock size estimation was developed. The current model was preceded by an optimization model which was not politically accepted! The paper touches on the problems of technical consultation on a sensitive political issue. Key words-Decision
support
systems,
fisheries management,
government,
modelling,
planning
Eur.J. opl Rex Vol. 33, pp. 212-222,1988
A COMPREHENSIVE ENERGY MODEL IN THE MUNICIPAL ENERGY PLANNING PROCESS CLAS-OTTO WENE and Bo RYDBN
Energy
Systems
Technology,
Department of Energy Conversion, Chalmers S-412 96 Gothenburg, Sweden
University
of Technology,
Abstract-Based on several years of experience, the procedural aspects of the use of a comprehensive LP-model for community energy planning is discussed. The community energy system is seen as a technically complex, open system which is managed by a network of organizations (esoteric boxes). Technical complexity, closure and lack of unique management raises specific procedural problems for which solutions are suggested. The network management gives the comprehensive model a special role in the planning process is providing for improved information flows and the conflict resolution. The viability of the paradigm of learning is noted. A methodology to merge substantive and procedural aspects is proposed. Key words-Energy,
planning,
urban
affairs,
learning,
optimization