Discussion: “Principles of a General Quaternion-Operator Method of Spatial Kinematic Synthesis” (Sandor, George N., 1968, ASME J. Appl. Mech., 35, pp. 40–46)

1969 ◽  
Vol 36 (2) ◽  
pp. 378-378
Author(s):  
E. J. F. Primrose
Keyword(s):  
Operator Method ◽  
Kinematic Synthesis

Principles of a General Quaternion-Operator Method of Spatial Kinematic Synthesis

1968 ◽  
Vol 35 (1) ◽  
pp. 40-46 ◽  
Author(s):  
George N. Sandor
Keyword(s):  
Operator Method ◽  
Kinematic Chain ◽  
Point Theory ◽  
System Of Equations ◽  
Motion Generation ◽  
Kinematic Synthesis ◽  
Special Cases ◽  
General Complex ◽  
Spatial Method ◽  
Space Mechanisms

The basic concepts of a general method of kinematic synthesis of space mechanisms are developed by means of vectors and quaternion operators applicable to path, function, and motion generation (body guidance) for finite and infinitesimal displacements (point, order, and combined point-order approximations). For writing the position equations, space mechanisms are represented by one or more loops of a general kinematic chain of ball-jointed bar-slideball members. Appropriate mathematical constraints on the relative freedom of these members render the general chain equivalent to the represented mechanism. The method leads to a system of equations of canonical simplicity, uniform for all tasks of finite spatial synthesis, often yielding closed-form linear solutions for small numbers of precision conditions. The same system of equations is then used to refine the solution for greater precision by numerical methods. Typical applications are indicated, some involving the use of a spatial finite circlepoint-center point theory, which includes classical planar Burmester theory as one of its special cases. An earlier general complex-number method of planar synthesis is shown to be a special case of the general spatial method introduced here.

scholarly journals A Dynamical Study of Fusion Hindrance with Nakajima-Zwanzig Projection Method

2021 ◽  
Author(s):  
Yasuhisa Abe ◽  
David Boilley ◽  
Quentin Hourdillé ◽  
Caiwan Shen
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Operator Method ◽  
Initial Distribution ◽  
Physical Parameters ◽  
Relaxation Processes ◽  
Fast Variable ◽  
Dynamical Study ◽  
Injection Point ◽  
Slow Variables

Abstract A new framework is proposed for the study of collisions between very heavy ions which lead to the synthesis of Super-Heavy Elements (SHE), to address the fusion hindrance phenomenon. The dynamics of the reaction is studied in terms of collective degrees of freedom undergoing relaxation processes with different time scales. The Nakajima-Zwanzig projection operator method is employed to eliminate fast variable and derive a dynamical equation for the reduced system with only slow variables. There, the time evolution operator is renormalised and an inhomogeneous term appears, which represents a propagation of the given initial distribution. The term results in a slip to the initial values of the slow variables. We expect that gives a dynamical origin of the so-called “injection point s” introduced by Swiatecki et al in order to reproduce absolute values of measured cross sections for SHE. A formula for the slip is given in terms of physical parameters of the system, which confirms the results recently obtained with a Langevin equation, and permits us to compare various incident channels.

A nonlocal operator method for finite deformation higher-order gradient elasticity

2021 ◽  
Vol 384 ◽  
pp. 113963
Author(s):  
Huilong Ren ◽  
Xiaoying Zhuang ◽  
Nguyen-Thoi Trung ◽  
Timon Rabczuk
Keyword(s):  
Finite Deformation ◽  
Gradient Elasticity ◽  
Operator Method ◽  
Higher Order ◽  
Nonlocal Operator
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