A sufficient condition for near-optimal stochastic controls and its application to manufacturing systems

Many deadlock prevention policies on the basis of Petri nets dealing with deadlock problems in flexible manufacturing systems exist. However, most of them do not consider uncontrollable and unobservable transitions. This chapter solves deadlock problems in Petri nets with uncontrollable and unobservable transitions. A sufficient condition is developed to decide whether an existing deadlock prevention policy is still applicable in a Petri net with uncontrollable and unobservable transitions, when the policy itself is developed under the assumption that all the transitions are controllable and observable. Moreover, the author develops a deadlock prevention policy to design liveness-enforcing supervisors for a class of Petri nets with partial observability and controllability of transitions. Furthermore, a sufficient condition to decide the existence of a monitor to enforce a liveness constraint is developed.

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Synthesis of Decision Models and Algorithms in Manufacturing Systems

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.791.108 ◽

2015 ◽

Vol 791 ◽

pp. 108-115

Author(s):

Łukasz Wojciechowski ◽

Piotr Pazowski ◽

Tadeusz Cisowski

Keyword(s):

Decision Making ◽

Manufacturing Systems ◽

Production Systems ◽

Decision Rules ◽

Decision Models ◽

Sufficient Condition ◽

Necessary And Sufficient Condition ◽

Necessary And Sufficient

In this paper the synthesis of models and algorithms to identify situations at the orthogonal structure of decision rules in simulation management tasks and operating indicators in production systems was accomplished. Necessary and sufficient condition for identification of decision-making situations was formulated and proved.

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The Current Situation in Chemical Stabilization of Biological Materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093912 ◽

1972 ◽

Vol 30 ◽

pp. 132-133

Author(s):

John H. Luft

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Osmium Tetroxide ◽

Molecular Level ◽

Cross Linking ◽

Chemical Stabilization ◽

Specimen Preparation ◽

Sufficient Condition ◽

Radio Telescopes

With information processing devices such as radio telescopes, microscopes or hi-fi systems, the quality of the output often is limited by distortion or noise introduced at the input stage of the device. This analogy can be extended usefully to specimen preparation for the electron microscope; fixation, which initiates the processing sequence, is the single most important step and, unfortunately, is the least well understood. Although there is an abundance of fixation mixtures recommended in the light microscopy literature, osmium tetroxide and glutaraldehyde are favored for electron microscopy. These fixatives react vigorously with proteins at the molecular level. There is clear evidence for the cross-linking of proteins both by osmium tetroxide and glutaraldehyde and cross-linking may be a necessary if not sufficient condition to define fixatives as a class.

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