The use of solar sail and solar electric propulsion systems for missions to Mars and Mercury was discussed. It was found that no propellant mass was required for the space flights during interplanetary travel. The min...
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The use of solar sail and solar electric propulsion systems for missions to Mars and Mercury was discussed. It was found that no propellant mass was required for the space flights during interplanetary travel. The minimum transfer time and minimum fuel expenditure for Mars and Mercury missions using solar sail and SEP was computed. Analysis shows that solar sail was suitable for Mercury mission and SEP performs well for Mars mission.
Procedures like start-up, product change-over, or shutdown of processing systems usually involve the manipulation of continuous and discrete controls. To optimize such procedures, the use of hybrid models is often app...
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Procedures like start-up, product change-over, or shutdown of processing systems usually involve the manipulation of continuous and discrete controls. To optimize such procedures, the use of hybrid models is often appropriate to account for the change of dynamics during the transition. Some recently developed approaches for hybrid system optimization are based on mixed-integer linear programming. Applications reveal that the complexity inherent to these approaches considerably limits the applicability to industrial-size problems. This paper suggests as an alternative a tailor-made algorithm that optimizes the discrete and continuous degrees of freedom in a two-stage procedure. While the discrete controls are selected by a graph search algorithm, the continuous controls are obtained by embedded nonlinear programming. The method is illustrated for the start-up of a CSTR.
A sufficient condition for robust stability of nonlinear constrained Model Predictive Control (MPC) with respect to plant/ model mismatch is derived. This work is an extension of a previous study On the unconstrained ...
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A sufficient condition for robust stability of nonlinear constrained Model Predictive Control (MPC) with respect to plant/ model mismatch is derived. This work is an extension of a previous study On the unconstrained nonlinear MPC problem, and is based on nonlinear programming sensitivity concepts. It addresses the discrete time state feedback problem with all states measmed. A strategy to estimate bounds on the plant/model mismatch is proposed, that can be used off-line as a tool to assess the extent of model mismatch that can he tolerated to guarantee robust stability.
An analysis is made of the role of Fibonacci numbers in some quadratic Diophantine equations. A general solution is obtained for finding factors in sums of Fibonacci numbers. Interpretation of the results is facilitat...
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An analysis is made of the role of Fibonacci numbers in some quadratic Diophantine equations. A general solution is obtained for finding factors in sums of Fibonacci numbers. Interpretation of the results is facilitated by the use of a modular ring which also permits extension of the analysis. [ABSTRACT FROM AUTHOR]
We discuss a general model for the marketing of seasonal products, namely products for which the time intervals devoted to production and sales are distinct. The firm can advertise the product, thus affecting the sale...
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The need of nonlinear analysis as well as linear-static analysis for some problems in product designing is discussed. A linear-static analysis is done assuming that induced displacements are small, change in structura...
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The need of nonlinear analysis as well as linear-static analysis for some problems in product designing is discussed. A linear-static analysis is done assuming that induced displacements are small, change in structural stiffness caused by loading are negligible, and the magnitude and direction of the load do not change while the structure deforms. But some cases require nonlinear analysis, including the case of geometric nonlinearities, material nonlinearities, and contact nonlinearities. The mechanisms of nonlinear analysis advances FEA software are also described.
This paper advanced mixed integer nonlinear programming (MINLP) algorithms mixed with constraint programming (CP) to solve industrial process hybrid model mixed with logical rule. CP methods have proved to be successf...
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This paper advanced mixed integer nonlinear programming (MINLP) algorithms mixed with constraint programming (CP) to solve industrial process hybrid model mixed with logical rule. CP methods have proved to be successful in solving highly constrained discrete optimization and feasibility problems. It can effectively solve hybrid model mixed with logical rule by integrating CP, nonlinear programming and mixed integer linear programming. Computational results demonstrated this algorithm.
Conjugate gradient optimization algorithms depend on the search directions with different choices for the parameter in the search directions. In this note, conditions are given on the parameter in the conjugate gradie...
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Conjugate gradient optimization algorithms depend on the search directions with different choices for the parameter in the search directions. In this note, conditions are given on the parameter in the conjugate gradient directions to ensure the descent property of the search directions. Global convergence of such a class of methods is discussed. It is shown that, using reverse modulus of continuity function and forcing function, the new method for solving unconstrained optimization can work for a continuously differentiable function with a modification of the Curry-Altman's step-size rule and a bounded level set. Combining PR method with our new method, PR method is modified to have global convergence *** experiments show that the new methods are efficient by comparing with FR conjugate gradient method.
This work intends to present and to analyze a new penalty method that purposes to solve the general nonlinear programming problem subject to inequality constraints. The proposed method has the important feature of bei...
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This work intends to present and to analyze a new penalty method that purposes to solve the general nonlinear programming problem subject to inequality constraints. The proposed method has the important feature of being completely differentiable and combines features of both exterior and interior penalty methods. Numerical results for some problems are commented on. International Federation of Operational Research Societies 2001.
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