A new Monte Carlo algorithm which provides enhanced sampling in the calculation of equilibrium thermodynamic properties of spin systems is presented. The algorithm proposed performs trial moves based on the generalize...
详细信息
A new Monte Carlo algorithm which provides enhanced sampling in the calculation of equilibrium thermodynamic properties of spin systems is presented. The algorithm proposed performs trial moves based on the generalized statistical distributions derived from a modification of the Gibbs-Shannon entropy by Tsallis. Results for a two-dimensional Ising model demonstrate that the algorithm leads to a greatly enhanced rate of barrier crossing and convergence in the calculation of equilibrium thermodynamic averages. Comparison is made with standard Metropolis Monte Carlo.
This paper outlines a control framework being developed for the TRYM model. The current procedure minimises a quadratic social loss function that targets non-steady-state settings for unemployment and inflation. The i...
详细信息
This paper outlines a control framework being developed for the TRYM model. The current procedure minimises a quadratic social loss function that targets non-steady-state settings for unemployment and inflation. The iterative technique is described in detail, and illustrated using the example of a temporary terms of trade shock. The effects of the shock on the model are compared for two separate policy regimes, one using the default TRYM policy reactions, and the other from the optimal control procedure. The limitations of using control techniques as an aid to the policy-formation process, and the benefits to be derived from implementing optimal control on a model like TRYM, are briefly discussed. Copyright (C) 1997 Elsevier Science Ltd.
Most programs from scientific computing can benefit from the use of numerical libraries which provide efficient implementations for standard solution methods that often occur in numerical simulations. This is especial...
详细信息
ISBN:
(纸本)0818680431
Most programs from scientific computing can benefit from the use of numerical libraries which provide efficient implementations for standard solution methods that often occur in numerical simulations. This is especially true for parallel scientific computing. A methodology that allows the integration of library functions without any additional programming effort would ease this programming style. In this paper we address the question how to integrate library procedures into hierarchically organized parallel programs. The hierarchical structure of a specific algorithms results from a top-down decomposition into submethods which can be realized by library functions. The integration of library functions nor only requires a correct specification of data dependencies between different modules but has also to take into account a possible distribution of data among the processors. We present algorithms for the adaptation of library modules such that their functional type and underlying data distribution fit into the hierarchical framework. The adaptation includes the construction of data flow graphs that can be used to determine data distributions for the library modules such that a minimal global execution time results.
This paper outlines a control framework being developed for the TRYM model. The current procedure minimises a quadratic social loss function that targets non-steady-state settings for unemployment and inflation. The i...
详细信息
This paper outlines a control framework being developed for the TRYM model. The current procedure minimises a quadratic social loss function that targets non-steady-state settings for unemployment and inflation. The iterative technique is described in detail, and illustrated using the example of a temporary terms of trade shock. The effects of the shock on the model are compared for two separate policy regimes, one using the default TRYM policy reactions, and the other from the optimal control procedure. The limitations of using control techniques as an aid to the policy-formation process, and the benefits to be derived from implementing optimal control on a model like TRYM, are briefly discussed. Copyright (C) 1997 Elsevier Science Ltd.
Robust and performant numerical software for control systems analysis and design, such as the SLICOT and RASP libraries, is an essential ingredient in modern computer aided control systems design. To avoid duplicating...
详细信息
Robust and performant numerical software for control systems analysis and design, such as the SLICOT and RASP libraries, is an essential ingredient in modern computer aided control systems design. To avoid duplicating the implementation efforts and ensure a wider dissemination, the originators of the SLICOT and RASP libraries have agreed to combine their libraries and make the joint library freely available. To extend the scope of cooperation, a thematic network for numerics in control NICONET is set up. This paper motivates the need for such a network and describes the objectives, benefits and main network activities.
作者：
Gheorghe BãluṭăŞtefan ResmeriṭăGheorghe Bäluṭă
“Gh. Asachi” Technical University of Iasi Faculty of Electrical Engineering Electric Drives and Power Electronics Department Str. Horia No. 7-9 6600 Iasi Romania tel.032/112770 Ştefan Resmeriṭà
“Gh. Asachi” Technical University of Iasi Faculty of Automatic Control and Computer Engineering Department of Automatic Control and Industrial Informatics Str. Horia No. 7-9 6600 Iasi Romania tel. 032/116502 tuiasi.ro
This paper presents a method for Stepper Motor (SM) speed control by means of a minor loop. The compatibility of the SM with the digital electronics allowed a PC to be used for implementing the control algorithm, the ...
详细信息
This paper presents a method for Stepper Motor (SM) speed control by means of a minor loop. The compatibility of the SM with the digital electronics allowed a PC to be used for implementing the control algorithm, the SM control being achieved by two hardware interface levels. The SM command is realized with two specialized circuits: L297 (SM controller) and L298N (driver). The control signals for this level are generated through a parallel port 18255 and a programmable timer 18253. Some other circuits complete the microprocessor interface. The software has the following tasks: speed measurement and control algorithm achievement of a PI type. To tune this controller the system characteristics are measured, when the system is unstable, having a relay instead of the PI part. There are treated aspects on choosing the sample period, the position transducer, and the type of speed measurement.
In this paper we introduce a robust control problem for multiple uncertainties of different sizes which are derived from data distributions of plants. In order to analyze the problem, we show a new algorithm of simult...
详细信息
In this paper we introduce a robust control problem for multiple uncertainties of different sizes which are derived from data distributions of plants. In order to analyze the problem, we show a new algorithm of simultaneous modeling and design of controllers with simple parametrizations of plants, and demonstrate the difference between the conventional robust controller and the proposed one. The features of the algorithm are that nominal models as well as controllers are free parameters, and they are simultaneously determined to optimize the performances of the resulting closed loop systems for multiple constraints of different sizes of data distributions.
A package of MATLAB macros for polynomial matrix operations and equations as well as control design procedures based on them has been developed that is called Polynomial Toolbox. The package covers basic operations wi...
详细信息
A package of MATLAB macros for polynomial matrix operations and equations as well as control design procedures based on them has been developed that is called Polynomial Toolbox. The package covers basic operations with polynomial matrices, special forms of polynomial matrices as well as several alternative routines to solve various linear polynomial matrix equations and polynomial matrix factorization problems. In addition, procedures for solving both standard and modern control design problems for linear multi-input multi-output systems based on polynomial matrix operations and equations are supported. The current contents of the Toolbox is reported together with a definition of the polynomial matrix format.
The aim of the paper is to present a method for the design of a glide-slope coupler of an aircraft using an optimal H ∞ approach obtained via the theory of singularly perturbed systems. The benefits of this optimal d...
详细信息
The aim of the paper is to present a method for the design of a glide-slope coupler of an aircraft using an optimal H ∞ approach obtained via the theory of singularly perturbed systems. The benefits of this optimal design procedure are emphasized by comparing computational aspects, tracking and robustness performances with the ones obtained when using suboptimal H ∞ methods.
In this paper, we describe the algorithmic options of Release A of LANCELOT, a Fortran package for large-scale nonlinear optimization, We then present the results of intensive numerical tests and discuss the relative ...
详细信息
In this paper, we describe the algorithmic options of Release A of LANCELOT, a Fortran package for large-scale nonlinear optimization, We then present the results of intensive numerical tests and discuss the relative merits of the options, The experiments described involve both academic and applied problems. Finally, we propose conclusions, both specific to LANCELOT and of more general scope.
暂无评论