Operating procedures hierarchical modeling

In the first chapter of Volume 2 (hereinafter referred to as 21 1) we presented the general framework of MODEL.LA., a modeling language that can capture the hierarchical and distributed character of processing systems. We will employ all aspects of MODEL.LA. in order to develop a complete and consistent description of plants that will satisfy the modeling needs for the synthesis of operating procedures. 

Lakshmanan, R., and Stephanopoulos, G Synthesis of operating procedures for complete chemical plants. I. Hierarchical, structured modeling for nonlinear planning. Comput. Chem. Eng. 12, 985 (1988a). 

One approach to the design of complex models is to build differential operators that can be assembled into a complete model in a hierarchical manner. A differential operator can be simply defined as an operator that takes one or more inputs and manipulates them in some way to produce one or more output responses continuously. (In a computer model, a differential operator becomes a function, subroutine, or procedure.)... 

Mission and activity models describe in a hierarchic structure the goals and the available recovery activities from missions-not-as-planned that make up the human operators high-level behavioral repertoire in the mission. The next level of decomposition of the action of the mission is a set of high-level procedures (that can be stored as a fairly generic set of routines, e.g., look at or fixate). Finally, there are the specific activities in active action packets RAPS, which are the process by which the human operator affects the simulation. 

Feature diagrams are a formal representation of product data with a precise semantics. Consequently, they define a unique mathematical model of the product data that consists of the hierarchical structure and additional logical formulas that specify the properties and links to aU product parts. The analyzing procedures presented here operate on purely logical representations of the product data. As a consequence, the structure and content of a feature diagram have to be transformed into an equivalent representation in logic. 

This study presents a procedure for the design or improvement of mineral flotation circuits, based on a mathematical programming model with disjunctive equations. The procedure is characterized by 1. The development of hierarchized superstructures, such that the first level represents certain separation tasks. The second level represents circuits of equipment needed to carry out the tasks. 2. A MILP mathematical model is developed which includes the selection of equipment, first principles, and operational conditions. 3. The objective function is the maximization of profits. Examples are included to demonstrate the advantages of the procedure. 

The present study presents the formulation of a new procedure for the design or improvement of flotation circuits for minerals, characterized by (a) Superstructures are developed in a hierarchical form, (b) A mathematical model which includes disjunctive expressions for the selection of the equipment, first principles, operational conditions, and logic expressions, (c) The objective function represents maximization of profit. The resultant model represents an MILP model. 

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