37 research outputs found
Coulomb Distortion Effects for (e,e'p) Reactions at High Electron Energy
We report a significant improvement of an approximate method of including
electron Coulomb distortion in electron induced reactions at momentum transfers
greater than the inverse of the size of the target nucleus. In particular, we
have found a new parametrization for the elastic electron scattering phase
shifts that works well at all electron energies greater than 300 . As an
illustration, we apply the improved approximation to the reaction
from medium and heavy nuclei. We use a relativistic ``single particle'' model
for as as applied to and to recently measured data
at CEBAF on to investigate Coulomb distortion effects while
examining the physics of the reaction.Comment: 14 pages, 3 figures, PRC submitte
GW25-e1143 Alterations of the calreticulin-STAT3 pathway associates with mitochondria damage in selenium deficiency rat hearts
Stimulus Pulse-Based Distributed Control for the Locomotion of a UBot Modular Robot
A distributed control algorithm based on a stimulus pulse signal is proposed in this paper for the locomotion of a Modular Self-reconfigurable Robot (MSRR). This approach can adapt effectively to the dynamic changes in the MSRR's topological configuration: the functional role of the configuration can be recognized through local topology detection, dynamic ID address allocation and local topology matching, such that the features of the entire configuration can be identified and thereby the corresponding stimulus signals can be chosen to control the whole system for coordinated locomotion. This approach has advantages over centralized control in terms of flexibility and robustness, and communication efficiency is not limited by the module number, which can realize coordinated locomotion control conveniently (especially for configurations made up of massive modules and characterized by a chain style or a quadruped style)
A Synthetic Algorithm for Tracking a Moving Object in a Multiple-Dynamic Obstacles Environment Based on Kinematically Planar Redundant Manipulators
This paper presents a synthetic algorithm for tracking a moving object in a multiple-dynamic obstacles environment based on kinematically planar manipulators. By observing the motions of the object and obstacles, Spline filter associated with polynomial fitting is utilized to predict their moving paths for a period of time in the future. Several feasible paths for the manipulator in Cartesian space can be planned according to the predicted moving paths and the defined feasibility criterion. The shortest one among these feasible paths is selected as the optimized path. Then the real-time path along the optimized path is planned for the manipulator to track the moving object in real-time. To improve the convergence rate of tracking, a virtual controller based on PD controller is designed to adaptively adjust the real-time path. In the process of tracking, the null space of inverse kinematic and the local rotation coordinate method (LRCM) are utilized for the arms and the end-effector to avoid obstacles, respectively. Finally, the moving object in a multiple-dynamic obstacles environment is thus tracked via real-time updating the joint angles of manipulator according to the iterative method. Simulation results show that the proposed algorithm is feasible to track a moving object in a multiple-dynamic obstacles environment
Meson and Isobar Degrees of Freedom in A() reactions at
The effect of meson and isobar degrees of freedom in A()
and A(e,e'n) is studied for four-momentum transfers Q^2 in the range between
0.2 and 0.8 (GeV/c)^2. The calculations are performed in a non-relativistic
framework with explicit (N,\Delta,\pi) degrees-of-freedom. For the whole range
of momentum transfers under investigation the relative effect of the
meson-exchange and isobar degrees of freedom is significant. At low missing
momenta and quasi-elastic conditions, a tendency to reduce the (e,e'p) and
(e,e'n) differential cross sections is noticed. The greatest sensitivity is
found in the interference structure functions and . The recoil
polarization observables, on the other hand, are moderately affected by the
meson-exchange and -isobar currents.Comment: 16 pages (Revtex) + 18 figures (eps file
Stimulus Pulse-Based Distributed Control for the Locomotion of a UBot Modular Robot
A distributed control algorithm based on a stimulus pulse signal is proposed in this paper for the locomotion of a Modular Self-reconfigurable Robot (MSRR). This approach can adapt effectively to the dynamic changes in the MSRR's topological configuration: the functional role of the configuration can be recognized through local topology detection, dynamic ID address allocation and local topology matching, such that the features of the entire configuration can be identified and thereby the corresponding stimulus signals can be chosen to control the whole system for coordinated locomotion. This approach has advantages over centralized control in terms of flexibility and robustness, and communication efficiency is not limited by the module number, which can realize coordinated locomotion control conveniently (especially for configurations made up of massive modules and characterized by a chain style or a quadruped style)