Nonlinear behavior in the physical sciences and biology: some typical examples.

1995 ◽  
pp. 1-24
Keyword(s):  
Nonlinear Behavior ◽  
Physical Sciences

A Complex-Systems Approach to Organizations

2000 ◽  
Vol 9 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Daniel J. Svyantek ◽  
Linda L. Brown
Keyword(s):  
Complex Systems ◽  
Organizational Behavior ◽  
Systems Approach ◽  
Initial Conditions ◽  
Nonlinear Behavior ◽  
System Behavior ◽  
Physical Sciences ◽  
Systems Research ◽  
Context Specific ◽  
Insight Into

The physical sciences have developed new theories of nonlinear behavior of complex systems. Defining characteristics of complex systems include (a) being composed of many variables that interact strongly to determine system behavior, (b) sensitivity to initial conditions, and (c) stability across time. Two complex-system concepts, phase spaces and attractors, provide insight into the evolution of system behavior and make prediction of future behavior possible. It is proposed that complex-systems research has application to the study of organizations and social behavior. Organizational attractors exist and seem to be both sensitive to initial conditions and stable. The discussion of concepts from complex systems, and their application to organizations, provides insight into how organizational research should be conducted. If organizations are assumed to exhibit nonlinear behavior, more historical, longitudinal, and qualitative research methods should be used to provide context-specific descriptions of organizational behavior.

Advances in ultramicrotomy for physical sciences applications

1993 ◽  
Vol 51 ◽  
pp. 710-711
Author(s):  
G. McMahon ◽  
T. Malis
Keyword(s):  
Particle Surface ◽  
Zeolite Catalysts ◽  
Physical Sciences ◽  
Pull Out ◽  
Large Particles ◽  
Novel Applications ◽  
Metal Wires ◽  
Frequent Problem ◽  
Specific Orientation ◽  
Diamond Knife

As with all techniques which are relatively new and therefore underutilized, diamond knife sectioning in the physical sciences continues to see both developments of the technique and novel applications.Technique Developments Development of specific orientation/embedding procedures for small pieces of awkward shape is exemplified by the work of Bradley et al on large, rather fragile particles of nuclear waste glass. At the same time, the frequent problem of pullout with large particles can be reduced by roughening of the particle surface, and a proven methodology using a commercial coupling agent developed for glasses has been utilized with good results on large zeolite catalysts. The same principle (using acid etches) should work for ceramic fibres or metal wires which may only partially pull out but result in unacceptably thick sections. Researchers from the life sciences continue to develop aspects of embedding media which may be applicable to certain cases in the physical sciences.

Development of a Jacobian Module for Advanced Pulp and Paper Simulation and Control

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE
Keyword(s):  
Control System ◽  
Nonlinear Behavior ◽  
Simulation Software ◽  
Pulp And Paper ◽  
Pid Controllers ◽  
Tuning Parameters ◽  
Pid Tuning ◽  
Fixed Set ◽  
And Control ◽  
Operating Points

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.

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