Explicit Fields and Their Application to Structural Property Inspection of Physical Systems

1996 ◽  
Vol 29 (1) ◽  
pp. 4551-4556 ◽  
Author(s):  
S.Y. Huang ◽  
K. Youcef-Toumi
1999 ◽  
Vol 121 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Shih-Ying Huang ◽  
Kamal Youcef-Toumi

Bond graph models provide very useful insights into the structure of dynamic systems. One major advantage of using these models is the clear representation of constraints and independent state variables. However, certain over-constrained structures are not dealt with adequately with this approach. Such a situation arises when several energy storage elements of the same type are directly coupled by a junction structure. In these models, although the representations are legitimate in terms of physical meaning, the resultant excess states cause pitfalls in the inspection of system properties. This paper proposes the use of explicit fields to eliminate such ambiguities. It was found that the excess states caused by the topological structures can be totally eliminated by explicit fields. The excess states caused by the imposed sources then can be identified properly. Several applications are presented to illustrate the use of explicit fields.


Author(s):  
Okolie S.O. ◽  
Kuyoro S.O. ◽  
Ohwo O. B

Cyber-Physical Systems (CPS) will revolutionize how humans relate with the physical world around us. Many grand challenges await the economically vital domains of transportation, health-care, manufacturing, agriculture, energy, defence, aerospace and buildings. Exploration of these potentialities around space and time would create applications which would affect societal and economic benefit. This paper looks into the concept of emerging Cyber-Physical system, applications and security issues in sustaining development in various economic sectors; outlining a set of strategic Research and Development opportunities that should be accosted, so as to allow upgraded CPS to attain their potential and provide a wide range of societal advantages in the future.


Author(s):  
Curtis G. Northcutt

The recent proliferation of embedded cyber components in modern physical systems [1] has generated a variety of new security risks which threaten not only cyberspace, but our physical environment as well. Whereas earlier security threats resided primarily in cyberspace, the increasing marriage of digital technology with mechanical systems in cyber-physical systems (CPS), suggests the need for more advanced generalized CPS security measures. To address this problem, in this paper we consider the first step toward an improved security model: detecting the security attack. Using logical truth tables, we have developed a generalized algorithm for intrusion detection in CPS for systems which can be defined over discrete set of valued states. Additionally, a robustness algorithm is given which determines the level of security of a discrete-valued CPS against varying combinations of multiple signal alterations. These algorithms, when coupled with encryption keys which disallow multiple signal alteration, provide for a generalized security methodology for both cyber-security and cyber-physical systems.


AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1787-1790
Author(s):  
Boris A. Zeldin ◽  
Andrew J. Meade

Author(s):  
A. V. Smirnov ◽  
T. V. Levashova

Introduction: Socio-cyber-physical systems are complex non-linear systems. Such systems display emergent properties. Involvement of humans, as a part of these systems, in the decision-making process contributes to overcoming the consequences of the emergent system behavior, since people can use their experience and intuition, not just the programmed rules and procedures.Purpose: Development of models for decision support in socio-cyber-physical systems.Results: A scheme of decision making in socio-cyber-physical systems, a conceptual framework of decision support in these systems, and stepwise decision support models have been developed. The decision-making scheme is that cybernetic components make their decisions first, and if they cannot do this, they ask humans for help. The stepwise models support the decisions made by components of socio-cyber-physical systems at the conventional stages of the decision-making process: situation awareness, problem identification, development of alternatives, choice of a preferred alternative, and decision implementation. The application of the developed models is illustrated through a scenario for planning the execution of a common task for robots.Practical relevance: The developed models enable you to design plans on solving tasks common for system components or on achievement of common goals, and to implement these plans. The models contribute to overcoming the consequences of the emergent behavior of socio-cyber-physical systems, and to the research on machine learning and mobile robot control.


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