title: An algorithm for the synthesis of least restrictive controllable supervisors for extended finite-state machines

authors: Malik, Robi

abstract: This working paper proposes an algorithm for the synthesis of modular supervisors using extended finite-state machines, i.e., state machines with variables and guards on the transitions. Synthesis is performed by iteratively selecting components from a synchronous composition until a least restrictive controllable solution is obtained. This method is usually faster and produces smaller supervisors than standard monolithic synthesis, while offering the modelling benefits of variables. An example of manufacturing system control illustrates the approach.

text: An algorithm for the synthesis of least restrictive controllable supervisors for extended finite-state machines This working paper proposes an algorithm for the synthesis of modular supervisors using extended finite-state machines, i.e., state machines with variables and guards on the transitions. Synthesis is performed by iteratively selecting components from a synchronous composition until a least restrictive controllable solution is obtained. This method is usually faster and produces smaller supervisors than standard monolithic synthesis, while offering the modelling benefits of variables. An example of manufacturing system control illustrates the approach.

year: 2016

title: Investigation of a discus-milling process using a powder mixture of Al and TiO₂

authors: Liu, Z. G.

abstract: In this study, a powder mixture of Al and TiO₂ was employed to investigate the milling process in a discus mill. In this first report on this novel mechanical mill, several variables, including the milling time and powder charge and their effects on the microstructural evolution of powder particles, are monitored and studied. The study reveals that the dominant parameters of the milling process are the milling time and the starting powder charge, similar to the other high-energy ball-milling processes. The longer the milling time and the smaller the starting powder charge, the more homogeneous the mixing and the finer the microstructure of the powder particles. The reaction between Al and TiO₂ was not observed with a milling period as long as 6 hours, for the present materials. However, the reaction between Al and TiO₂, during the subsequent heat treatment, is influenced by the milling condition. The powders with the longer milling times and finer mixing microstructures also form a finer microstructure, after the reaction between Al and TiO₂  during heat treatment. The methods for achieving an optimal milling efficiency for the Al- TiO₂  system are discussed.

text: Investigation of a discus-milling process using a powder mixture of Al and TiO₂ In this study, a powder mixture of Al and TiO₂ was employed to investigate the milling process in a discus mill. In this first report on this novel mechanical mill, several variables, including the milling time and powder charge and their effects on the microstructural evolution of powder particles, are monitored and studied. The study reveals that the dominant parameters of the milling process are the milling time and the starting powder charge, similar to the other high-energy ball-milling processes. The longer the milling time and the smaller the starting powder charge, the more homogeneous the mixing and the finer the microstructure of the powder particles. The reaction between Al and TiO₂ was not observed with a milling period as long as 6 hours, for the present materials. However, the reaction between Al and TiO₂, during the subsequent heat treatment, is influenced by the milling condition. The powders with the longer milling times and finer mixing microstructures also form a finer microstructure, after the reaction between Al and TiO₂  during heat treatment. The methods for achieving an optimal milling efficiency for the Al- TiO₂  system are discussed.

year: 2006

title: The development of an indigenous knowledge program in a New Zealand Maori-language immersion school

authors: Harrison, Barbara

subjects: knowledge

abstract: In 1985, Te Wharekura o Rakaumangamanga initiated a Maori-language immersion program for children ages 5 through 18. In recent years, a program based on Waikato-Tainui tribal epistemology has been incorporated into the language immersion program. This article describes the community context and the language immersion and tribal knowledge programs. We consider the relationship of these programs to individual and tribal self-determination and to theories of minority achievement, particularly the work of John Ogbu.

text: The development of an indigenous knowledge program in a New Zealand Maori-language immersion school In 1985, Te Wharekura o Rakaumangamanga initiated a Maori-language immersion program for children ages 5 through 18. In recent years, a program based on Waikato-Tainui tribal epistemology has been incorporated into the language immersion program. This article describes the community context and the language immersion and tribal knowledge programs. We consider the relationship of these programs to individual and tribal self-determination and to theories of minority achievement, particularly the work of John Ogbu.

year: 2005-03