This paper presents fast and simple algorithms for directly constructing force-closure grasps based on the shape of the grasped object. The synthesis of force-closure grasps finds independent regions of contact for the fingertips, such that the motion of the grasped object is totally constrained. A forceclosure grasp implies equilibrium grasps exist. In the reverse direction, we show that most nonmarginal equilibrium grasps are force-closure grasps.

This paper shows how all force-closure grasps can be made stable by constructing virtual springs at the contacts, such that the grasped object has a desired stiffness matrix about its stable equilibrium. The paper develops a simple geometric relation between the stiffness of the grasp and the spatial configuration of the virtual springs at the contacts. The stiffness of the grasp also depends on whether the points of contact stick or slide without friction on straight or curved edges or faces of the object.

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Uniformly sheared flows have been generated in a high-speed wind tunnel at shear rates higher than previously achieved, in an effort to approach those in the inner turbulent boundary layer. As at lower shear rates, the turbulence structure was found to attain a self-similar state with approximately constant anisotropies and exponential kinetic energy growth. The normal Reynolds stress anisotropies showed no systematic dependence upon the mean shear within the examined range; however, the shear stress anisotropy was significantly lower than the low-shear values, in conformity with boundary layer measurements and direct numerical simulations of homogeneous shear flow.

A Pythagorean fuzzy set is one of the successful extensions of the intuitionistic fuzzy set to handle the uncertain and fuzzy information in a more wider way. In this paper, some new exponential similarity measures (SMs) for measuring the similarities between objects are proposed. For it, we used the exponential function for the membership and the non-membership degrees and hence defined some series of the SMs for PFSs. The various desirable properties and their relations are examined. Several counter-intuitive cases are given to show the effectiveness of the proposed measures with the existing SMs. Furthermore, examples to classify the pattern recognition and the decision-making problems are presented and compared with the existing approaches.

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