It was recently pointed out that the decays B+ → D∗+ s γ and B+ → D∗+γ can be used for an extraction of |Vub|. The theory of these decays is poorly understood. It was shown that in a world of almost degenerate b and c-quarks the decay would be computable. The severe difficulties that are encountered in the realistic calculation stem primarily from the very hard photon produced in the two body d...

We consider a model for one-dimensional transversal oscillations of an elastic-ideally plastic beam. It is based on the von Mises model of plasticity and leads after a dimensional reduction to a fourth-order partial differential equation with a hysteresis operator of Prandtl-Ishlinskii type whose weight function is given explicitly. In this paper, we study the case of clamped beams involving a ...

Based on experimental results, a dislocation material model describing the dynamic strain aging effect at different temperatures is presented. One and two stage loading tests were performed in order to investigate the influence of the loading direction as well as the temperature influence due to the hardening mechanism. Bergström’s theory of work hardening was used as a basis for the model deve...

In this paper, the kinematic workspace characteristics of a crab-like legged vehicle are investigated using a 2-D model. The alternative kinematic configurations and their corresponding workspace constraints are discussed, and the vehicle configuration of most interest identified. It is shown that, for constant vehicle body attitude, only two parameters affect the kinematic workspace, foot over...

This paper presents, analyzes and compares two different kinematic modeling methods for obtaining the kinematic model of general wheeled mobile robots. The two kinematic modeling methods are based on absolutely different concepts: on the one hand the constraints of each wheel and on the other the well known homogeneous transformation matrix theory. These methods are applied to the most common w...

In the applications of parallel robots, kinematic calibration is required to eliminate the errors resulting from the manufacturing and assembly. In this paper, a new method for calibrating a parallel robot is proposed. An error model for kinematic calibration is constructed using differential geometry method. All leg length information and pose error are obtained based on measurement results co...

The learning process of reaching movements was examined under novel environments whose kinematic and dynamic properties were altered. We used a kinematic transformation (visuomotor rotation), a dynamic transformation (viscous curl field), and a combination of these transformations. When the subjects learned the combined transformation, reaching errors were smaller if the subject first learned t...

This paper introduces the novel notion of kinematic reductions for mechanical systems and studies their controllability properties. We focus on the class of simple mechanical control systems with constraints and model them as a ne connection control systems. For these systems, a kinematic reduction is a driftless control system whose controlled trajectories are also solutions to the full dynami...

This paper describes a study of whether haptic feedback can be used to represent information that is normally difficult to obtain via visual feedback in telerobotic system. Problems of manipulator kinematic condition such as singularity and joint limit have been well known for a long time. Kinematic condition of the manipulator is difficult to be recognized visually. Poor kinematic condition of...

2 Stochastic optimal control (discrete time) 2 2.1 The Linear-quadratic-Gaussian (LQG) case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Message passing in LQG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3 Special case: kinematic control . . . . . . . . . . . . . . . . . . . . . . . . . ...