Showing papers in "International Journal of Systems Science in 1970"
TL;DR: Today, as a step towards the control of complex dynamic systems, models are being used ubiquitously, being modelled, for instance, are the air traffic flows around New York, the endocrine balances of the pregnant sheep, and the flows of money among the banking centres.
Abstract: Today, as a step towards the control of complex dynamic systems, models are being used ubiquitously. Being modelled, for instance, are the air traffic flows around New York, the endocrine balances of the pregnant sheep, and the flows of money among the banking centres.
1,017 citations
TL;DR: Control policies are synthesized for a dynamic economic model of the continuous-time multiplier class to provide a very powerful method for determining control policies for economic systems.
Abstract: In this paper it is shown that continuous-time modal control theory provides u very powerful method for determining control policies for economic systems: specifically, control policies are synthesized for a dynamic economic model of the continuous-time multiplier class.
21 citations
TL;DR: In this paper, the use of the well-known Kalman filter as a technique for prediction of time-series and its similarities to optimal adaptive forecasting is discussed, and it is shown that for a single time series consisting of trend and trend-change and stochastic disturbances, the filter gives predictions identical to those of Thoil-Nerlove-Wage who in 1964 developed optimal adaptive forecast for such a series.
Abstract: The principal objective of this paper is to indicate the use of the well-known Kalman filter as a technique for prediction of time-series and its similarities to optimal adaptive forecasting. It is shown that for a single time-series consisting of trend and trend-change and stochastic disturbances, the filter gives predictions identical to those of Thoil-Nerlove-Wage who in 1964 developed optimal adaptive forecasting for such a series. A numerical example illustrates the use of the filter and verifies the analytical results.
11 citations
TL;DR: This paper represents an early stage in an attempt to provide a working tool for use in evaluating and deciding upon alternatives strategies and actions, and in describing and computing successive moves, in the context of ‘real life games’.
Abstract: This paper represents an early stage in an attempt to provide a working tool for use in evaluating and deciding upon alternatives strategies and actions, and in describing and computing successive moves, in the context of ‘real life games’. A definition of the ‘real game’ is offered, together with a provisional list of the necessary variables and formulae needed to control such a game. Finally, a much simplified example is given. The intention is to utilize heuristic problem solving and decision making in real games, coupled with the degree of formalism necessary to permit eventual computa tion. The formalism is applied to the description of the game, and not to the game itself, which may be as haphazard as real business games usually are, provided that it is not completely random and is goal oriented. The capabilities of the players, as well as the rules and strategies of the game, are included in the formalism.
6 citations
TL;DR: Stochastic approximation applied to sampled data system parameters including sampling interval to derive uniform distribution of sampling interval values.
Abstract: This paper discusses the application of stochastic approximation to the estimation of sampled-data system parameters, including the sampling interval. The sampled-date systems considered have a closed-loop configuration, continuous input and output signals, and error sampling. A continuous dynamic system follows a zero-order hold. Sufficient conditions are given for the mean-square convergence of a stochastic approximation algorithm of the Kiofer-Wolfowitz type which is used to estimate all the parameters of the sampled-data system. Simulation results are presented which illustrate the theoretical results. In addition, simulations indicate that good estimates of the mean values of parameters are still possible when the parameters have random components.
5 citations
TL;DR: In this paper, the nature of a new branch of technology known as technological forecasting is briefly examined and the nature, validity and usefulness of this activity are illustrated with examples drawn from the field of manufacturing engineering.
Abstract: In this paper the nature of a new branch of technology known as technological forecasting is briefly examined. The nature, validity and usefulness of this activity are illustrated with examples drawn from the field of manufacturing engineering. Its implications for modern scientific and engineering academic education are also considered.
4 citations
TL;DR: In this paper, control laws for cascaded-vehicle systems are derived by the application of modal control theory, and it is shown that the control laws thus derived lead to much simpler control Systems than alternative systems which have been derived by both continuous-time and discrete-time optimal control theory.
Abstract: In this paper, control laws for cascaded-vehicle systems are derived by the application of modal control theory. It is shown that the control laws thus derived lead to much simpler control Systems than alternative systems which have been derived by the application of both continuous-time and discrete-time optimal control theory.
3 citations
TL;DR: In this paper, the authors present theoretical methods which may have practical applications in determining the complete controllability of linear dynamical systems when the system A matrix, the input B matrix, and the output C matrix may be unknown.
Abstract: This paper presents theoretical methods which may have practical applications in determining the complete controllability of linear dynamical systems when the system A matrix, the input B matrix, and the output C matrix may be unknown. The criteria are obtained solely from the use of the input-state and the input-output experimental data of the given system.
3 citations
TL;DR: In this paper, the authors present two stability criteria for non-linear time-varying and time-invariant feedback systems using the passivity theorem and the concept of multipliers.
Abstract: This paper presents two stability criteria for a very broad class of non-linear time-varying as well as time-invariant non-linear feedback systems. The stability criteria are obtained by the use of the passivity theorem and the concept of multipliers in a more systematic, straightforward and unified manner. The results obtained generalize many previously published ones in several aspects.
3 citations
TL;DR: In this article, the problem of identification of the heat transfer coefficient between, two media is analyzed for the one-dimensional slab, in particular the equations of a practical furnace heating a slab are formulated, and the complete solution is obtained.
Abstract: The problem of identification of the heat-transfer coefficient between, two media is analysed for the one-dimensional slab. In particular the equations of a practical furnace heating a slab are formulated, and the complete solution is obtained. The identification problem is reduced to the minimization of a certain ‘ performance criterion ’, Different performance criteria are denned and analysed. Noisy measurements are also considered, and computer simulation examples are presented.
3 citations
TL;DR: In this paper, the authors formulates the system equations, state and control space constraints and ft performance index for the models of economic growth, and proposes a general algorithm for obtaining the optimal control policy using the principles of optimal control theory.
Abstract: This work formulates the system equations, state and control space constraints and ft performance index for the models of economic growth, and proposes a general algorithm for obtaining the optimal control policy using the principles of optimal control theory. The control and state trajectories are interpreted and the effects of different constants in the models are also studied. Certain interesting problems for further investigation are stated and references to other models and more general work in mathematical economics are cited.
TL;DR: The results presented in this paper are the discrete-time analogues of the results for continuous-time systems obtained by Porter (1970).
Abstract: In this paper it is shown that discrete-time modal control theory provides a very powerful technique for determining control policies for economic systems: specifically, control policies are synthesized for a dynamic economic model of the discrete-time multiplier class. The results presented in this paper are thus the discrete-time analogues of the results for continuous-time systems obtained by Porter (1970).
TL;DR: The method of steepest descent provides a very simple analogue learning model approach to the problem of identifying the parameters of a linear system by dividing the identification process into a series of stages the dimension of the search is successively reduced to zero and complete identification is achieved.
Abstract: The method of steepest descent provides a very simple analogue learning model approach to the problem of identifying the parameters of a linear system. The error between the system equation and the model equation is driven to zero along the steepest descent path. Unfortunately the zero error condition is not sufficient to ensure complete identification so that the identification process can terminate prematurely. A new sequential method is presented to overcome this problem. By dividing the identification process into a series of stages the dimension of the search is successively reduced to zero and complete identification is achieved. As an example the method is applied to the identification of eight parameters in a two-input second-order system. The method is suitable for one-line hybrid or digital computation.
TL;DR: A review of brain models falls historically into three periods as mentioned in this paper, the first dealing with what might be called the origins of the modern approach to brains and their activity and deals especially with the work of Sherrington and Pavlov.
Abstract: This review of brain models falls historically into three periods. The first deals with what might be called the origins of the modern approach to brains and their activity and deals especially with the work of Sherrington and Pavlov. The second, more recent, phase deals with models which are as much conceptual as derived immediately from observation, and owe a great deal to mathematics, logic and cognitive studies. Finally, an attempt is made to review the current state of knowledge of brain models from all the various relevant points of view and in tho light of some highly selected but typical experimental ovidence.
TL;DR: In this article, a model of a two-sector economic system with Lienard's equation is presented. Butler et al. considered the non-linear behaviour patterns of businesses and households and combined them with a classical economic growth mechanism to produce a system describable by Lienards equation.
Abstract: Classical, non-linear macroeconomic theory is considered as the basis for a model of a two-sector economic system. The non-linear behaviour patterns of businesses and households are combined with a classical economic growth mechanism to produce a system describable by Lienard's equation. Sufficient conditions for the existence, uniqueness and orbital asymptotic stability of a limit cycle are derived. These conditions are interpreted in an economic context. Stochastic stability of a region containing the deterministic limit cycle is shown when the system is randomly disturbed. The model is exercised using short-term contemporary data from the United Kingdom and a comparison is made with long-term economic trends. The comparison indicates that the addition of a control input into the model would not only enhance the model-data correspondence but also account for the economic reality that macroeconomic systems use government spending as a feedback control mechanism.
TL;DR: In this article, the Szego method was applied to generate improved Lyapunov functions systematically for the determination of the region of asymptotic stability of a non-linear power system.
Abstract: This paper applies Szego' method to generate improved Lyapunov functions systematically for the determination of the region of asymptotic stability of a non-linear power system. Only a single-machine infinite-bus systemis considered. Both polesaliency and damping effects are included. By way ofillustration a numerical example is considered for the damping coefficient is a function of the load angle.