After a reivew of basic concepts in multiple criteria optimization, the paper presents a characterization of noncooperative equilibria in multiple criteria games in normal form either by weighted sums or by. order-con...After a reivew of basic concepts in multiple criteria optimization, the paper presents a characterization of noncooperative equilibria in multiple criteria games in normal form either by weighted sums or by. order-consistent achievement scalarizing functions, for convex and nonconvex cases. Possible applications of multiple criteria games and such characterizations of their equilibria are indicated. The analysis of multiple criteria games might be especially useful when studying reasons of possible conflict escalation processes and ways of preventing them.展开更多
Axial overlap(AO)and percent pitch(PP)are considered as key position configuration parameters that affect the tandem cascade performance.The objective of the current study is to investigate the optimal design criteria...Axial overlap(AO)and percent pitch(PP)are considered as key position configuration parameters that affect the tandem cascade performance.The objective of the current study is to investigate the optimal design criteria for these two parameters in tandem cascades of subsonic highly-loaded two-dimensional compressors.Before that,the influence mechanisms of AO and PP are explored separately.Research results show that higher PP is beneficial for decreasing rear blade(RB)load,but an invalidity of gap flow occurs when it approaches 1.The change in AO has an influence on the adverse pressure gradient of the front blade(FB),and it also affects the gap flow strength and FB wake development.Then,the optimal design criteria for AO and PP are obtained in a large design space,which clarifies the matching relationship of the two parameters at different operating conditions.The best global range of AO is about-0.05 to 0.05 while PP is between 0.85 to 0.92,and PP should be smaller to avoid performance degradation as AO increases.According to the fault tolerance in practical applications,PP should be closer to the lower bound to ensure that the deterioration boundary is wide enough.展开更多
A design approach is presented in this paper for underactuation in robotic finger mechanisms. The characters of underactuated finger mechanisms are introduced as based on linkage and spring systems. The feature of sel...A design approach is presented in this paper for underactuation in robotic finger mechanisms. The characters of underactuated finger mechanisms are introduced as based on linkage and spring systems. The feature of self-adaptive enveloping grasp by underactuated finger mechanisms is discussed with feasible in grasping unknown objects. The design problem of robotic fingers is analyzed by looking at many aspects for an optimal functionality. Design problems and requirements for underactuated mechanisms are formulated as related to human-like robotic fingers. In particular, characteristics of finger mechanisms are analyzed and optimality criteria are summarized with the aim to formulate a general design algorithm. A general multi-objective optimization design approach is applied as based on a suitable optimization problem by using suitable expressions of optimality criteria. An example is illustrated as an improvement of finger mechanism in Laboratory of Robotics and Mechatronics （LARM） Hand. Results of design outputs and grasp simulations are reported with the aim to show the practical feasibility of the proposed concepts and computations.展开更多
文摘After a reivew of basic concepts in multiple criteria optimization, the paper presents a characterization of noncooperative equilibria in multiple criteria games in normal form either by weighted sums or by. order-consistent achievement scalarizing functions, for convex and nonconvex cases. Possible applications of multiple criteria games and such characterizations of their equilibria are indicated. The analysis of multiple criteria games might be especially useful when studying reasons of possible conflict escalation processes and ways of preventing them.
基金supported by the National Natural Science Foundation of China(Grant numbers 52106057,92152301)the Fundamental Research Funds for the Central Universities(Grant number D5000210483)+2 种基金the Foundation of State Level Key Laboratory of Airfoil and Cascade Aerodynamics(Grant numbers D5150210006,D5050220008)the 111 Project(No.B17037)the Key Laboratory of Flow Visualization and Measurement Techniques,AVIC Aerodynamics Research Institute(D5110220177).
文摘Axial overlap(AO)and percent pitch(PP)are considered as key position configuration parameters that affect the tandem cascade performance.The objective of the current study is to investigate the optimal design criteria for these two parameters in tandem cascades of subsonic highly-loaded two-dimensional compressors.Before that,the influence mechanisms of AO and PP are explored separately.Research results show that higher PP is beneficial for decreasing rear blade(RB)load,but an invalidity of gap flow occurs when it approaches 1.The change in AO has an influence on the adverse pressure gradient of the front blade(FB),and it also affects the gap flow strength and FB wake development.Then,the optimal design criteria for AO and PP are obtained in a large design space,which clarifies the matching relationship of the two parameters at different operating conditions.The best global range of AO is about-0.05 to 0.05 while PP is between 0.85 to 0.92,and PP should be smaller to avoid performance degradation as AO increases.According to the fault tolerance in practical applications,PP should be closer to the lower bound to ensure that the deterioration boundary is wide enough.
基金supported by Key International S&T Cooperation Project (Grant No. 2008DFA81280)Part of this work has been developed within the project No.27 of the Italy-China program 2006–2009+1 种基金A joined study of first author at Laboratory of Robotics and Mechatronics (LARM) during 2007–2008 has been supported by state scholarship program of China Scholarship Council (CSC)Innovation Foundation of Beijing University of Aeronautics and Astronautics (BUAA) for PhD Graduates
文摘A design approach is presented in this paper for underactuation in robotic finger mechanisms. The characters of underactuated finger mechanisms are introduced as based on linkage and spring systems. The feature of self-adaptive enveloping grasp by underactuated finger mechanisms is discussed with feasible in grasping unknown objects. The design problem of robotic fingers is analyzed by looking at many aspects for an optimal functionality. Design problems and requirements for underactuated mechanisms are formulated as related to human-like robotic fingers. In particular, characteristics of finger mechanisms are analyzed and optimality criteria are summarized with the aim to formulate a general design algorithm. A general multi-objective optimization design approach is applied as based on a suitable optimization problem by using suitable expressions of optimality criteria. An example is illustrated as an improvement of finger mechanism in Laboratory of Robotics and Mechatronics （LARM） Hand. Results of design outputs and grasp simulations are reported with the aim to show the practical feasibility of the proposed concepts and computations.
