A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast a...A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast and efficiently comparing to the original homotopy iteration method. Numerical examples for the ninepoint path synthesis of four-bar linkages show the advantages and efficiency of the improved homotopy iteration method.展开更多
This paper is concerned with the robust control synthesis of autonomous underwater vehicle(AUV) for general path following maneuvers.First,we present maneuvering kinematics and vehicle dynamics in a unified framework....This paper is concerned with the robust control synthesis of autonomous underwater vehicle(AUV) for general path following maneuvers.First,we present maneuvering kinematics and vehicle dynamics in a unified framework.Based on H∞ loop-shaping procedure,the 2-DOF autopilot controller has been presented to enhance stability and path tracking.By use of model reduction,the high-order control system is reduced to one with reasonable order,and further the scaled low-order controller has been analyzed in both the frequency and the time domains.Finally,it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.展开更多
A hardware/software co-synthesis method is presented for SoC designs consisting of both hardware IP cores and software components on a graph-theoretic formula tion. Given a SoC integrated with a set of functions and a...A hardware/software co-synthesis method is presented for SoC designs consisting of both hardware IP cores and software components on a graph-theoretic formula tion. Given a SoC integrated with a set of functions and a set of performance fa ctors, a core for each function is selected from a set of alternative IP cores and software components, and optimal partitions is found in a way to evenly bala nce the performance factors and to ultimately reduce the overall cost, size, pow er consumption and runtime of the core-based SoC. The algorithm formulates IP c ores and components into the corresponding mathematical models, presents a graph -theoretic model for finding the optimal partitions of SoC design and transform s SoC hardware/software co-synthesis problem into finding optimal paths in a we ighted, directed graph. Overcoming the three main deficiencies of the traditiona l methods, this method can work automatically, evaluate more performance factors at the same time and meet the particularity of SoC designs. At last, the approa ch is illustrated that is practical and effective through partitioning a practic al system.展开更多
It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-ind...It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-industrial production mode with minimum waste emission. A new conception of simple stoichiometric reaction is presented for reaction path synthesis problem. All simple stoichiometric reactions can be obtained by mathematical transformation for atom matrix of a reaction system. Based on the conception, a two-tier optimization method for complex reaction path synthesis problems is addressed. The first step is to determine the eco-nomic optimal overall reactions, and the second step to decompose each overall reaction into several sub-reactions and find out the best thermodynamic feasible reaction path. Further, a method of reaction path synthesis with waste closed-cycle is proposed based on simple stoichiometric reactions for achieving zero waste emission to poly-generation problem of multi-products. Case studies show that the proposed methods can efficiently solve practical re-action path synthesis problems.展开更多
The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-for...The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-form equations of a single point are constructed.The reduced Groebner basis in degree lexicographic ordering for the closed-form equations is then obtained using com-puter algebra.A 23623 Sylvester’s matrix can be con-structed by selecting 23 out of 89 Groebner bases.A 36th degree univariate equation is obtained directly from the determinate of the matrix.The same result can be obtained with a continuation method.A numerical example is given and verifies that the problem has at most 36 solutions in the complex field.展开更多
文摘A new algorithm called homotopy iteration method based on the homotopy function is studied and improved. By the improved homotopy iteration method, Polynomial systems with high Order and deficient can be solved fast and efficiently comparing to the original homotopy iteration method. Numerical examples for the ninepoint path synthesis of four-bar linkages show the advantages and efficiency of the improved homotopy iteration method.
基金a part of the project titled "Development of Key Marine Equipments for Enhancement of Ocean Industry-Development of Underwater Manipulator and Thrusting System Driven by Electric Motor" funded by the Ministry of Land, Transport and Maritime Affairs, Korea
文摘This paper is concerned with the robust control synthesis of autonomous underwater vehicle(AUV) for general path following maneuvers.First,we present maneuvering kinematics and vehicle dynamics in a unified framework.Based on H∞ loop-shaping procedure,the 2-DOF autopilot controller has been presented to enhance stability and path tracking.By use of model reduction,the high-order control system is reduced to one with reasonable order,and further the scaled low-order controller has been analyzed in both the frequency and the time domains.Finally,it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.
基金This project was supported by the Defense Pre-Research Project of the ‘Tenth Five-Year-Plan’ of China(41315040106) and the National"863"High Technology Research and Development Programof China (2003AAIZ2210)
文摘A hardware/software co-synthesis method is presented for SoC designs consisting of both hardware IP cores and software components on a graph-theoretic formula tion. Given a SoC integrated with a set of functions and a set of performance fa ctors, a core for each function is selected from a set of alternative IP cores and software components, and optimal partitions is found in a way to evenly bala nce the performance factors and to ultimately reduce the overall cost, size, pow er consumption and runtime of the core-based SoC. The algorithm formulates IP c ores and components into the corresponding mathematical models, presents a graph -theoretic model for finding the optimal partitions of SoC design and transform s SoC hardware/software co-synthesis problem into finding optimal paths in a we ighted, directed graph. Overcoming the three main deficiencies of the traditiona l methods, this method can work automatically, evaluate more performance factors at the same time and meet the particularity of SoC designs. At last, the approa ch is illustrated that is practical and effective through partitioning a practic al system.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29836140).
文摘It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-industrial production mode with minimum waste emission. A new conception of simple stoichiometric reaction is presented for reaction path synthesis problem. All simple stoichiometric reactions can be obtained by mathematical transformation for atom matrix of a reaction system. Based on the conception, a two-tier optimization method for complex reaction path synthesis problems is addressed. The first step is to determine the eco-nomic optimal overall reactions, and the second step to decompose each overall reaction into several sub-reactions and find out the best thermodynamic feasible reaction path. Further, a method of reaction path synthesis with waste closed-cycle is proposed based on simple stoichiometric reactions for achieving zero waste emission to poly-generation problem of multi-products. Case studies show that the proposed methods can efficiently solve practical re-action path synthesis problems.
基金supported by the National Basic Research Program of China(No.2004CB31800)the National Natural Science Foundation of China(Grant No.50475161)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China(No.2005-0013006)the National Hi-Tech Research and Development Program of China(No.2007AA04Z211).
文摘The problem of synthesizing a planar four-bar linkage with two given fixed pivots such that the coupler curve passes through five given points is considered with the Groebner-Sylvester hybrid approach.First,closed-form equations of a single point are constructed.The reduced Groebner basis in degree lexicographic ordering for the closed-form equations is then obtained using com-puter algebra.A 23623 Sylvester’s matrix can be con-structed by selecting 23 out of 89 Groebner bases.A 36th degree univariate equation is obtained directly from the determinate of the matrix.The same result can be obtained with a continuation method.A numerical example is given and verifies that the problem has at most 36 solutions in the complex field.
