MODEL Modeling-Scope

This overview is further detailed and structured in the following subchapter, where the characteristics of a global commodity value chain as well as the model scope is defined. 

In a model developed to analyze the trade-off between scale advantages from product-focused factories and reduced transport costs from market-focused factories Cohen and Moon (1991) and Moon (1989) consider a fixed charge incurred for each product-plant allocation and a concave production cost function. The cost function is transformed into a piecewise linear function. In a model developed for the paper industry, Philpott and Everett (2001, pp. 229-230) use pre-determined product mix "clusters" that are selected using binary variables and for which the effects on unit production costs and technical capacity are specified exogenously to model scope effects. 

Bacastow R. (1981). Numerical evaluation of the evasion factor. In Bolin B. (ed.), Carbon Cycle Modelling, SCOPE-16. Wiley, New York, pp. 95-101. 

Bolin B., ed., Carbon Cycle Modelling, SCOPE 16, Chichester, Wiley (1981). 

The tree of modeling-scope classes. It has two subclasses model and context. The first captures all those relationships that reflect assumptions, hypotheses, and conjectures, all of which define the contextu-ral scope of a model. The second captures the list of mathematical relationships describing the behavior of a generic-unit. 

MLR see multiple linear regression MM see molecular mechanics model applicability domain, 3, 68, 74 Model scope, 2,155... 

The solution of the above set of implicit DAE system is highly non-linear and stiff. Different assumptions may facilitate the integration, depending on physical situation, modelling scope and numerical solver. The most common assumptions are ... 

Note that attention is focused squarely on a retailer s function as a resale intermediary, whereas some of the horizontal competition frameworks treat retailers as the primary source of product (by excluding the retailers procurement activities from the model scope). Such models blur the distinction between the terms manufacturer and retailer. ... 

Establish a global coordinate system, and use a cubic box to confine the model scope. In this case, a point on the west side of the slope is taken as the origin the X-axis and Y-axis point to the east and north, respectively and the Z-axis is perpendicular to the XOY plane. The dimensions of the model are 20 m in the X-axis, 20 m in the Y-axis and 20 m in the Z-axis. 

The Pearl GTL plant consists of more than 80 separate process units for 2 separate production trains and common utilities. Modeling the whole plant and creating a complete virtual planf was neither considered feasible nor a requirement and the approach was therefore to make a fit-for-purpose MPDS. Approximately 35 units of 1 single train were identified as requirement for testing, validation, simulation studies and operator training. These units form the heart of the plant and include all major process and utility systems. Despite this reduced fit-for-purpose modeling scope the Pearl GTL MPDS is still one of the largest simulators in the world. 

Due to the complexity of the modeling scope it was decided to develop individual models for process units instead of 1 complex model. Combinations of models were made as required for the various users. The largest model combination, i.e. a... 

Fig. 5.2 Selection of configuration methods according to the modeling scope...

Figure 6.3 Three-layer onion for modeling scope.

Modeling Scope Lumping Technique Data Source Data Requirement (Feed) Data Requirement (Product) Reactor Operation Product Yield Colum Simula- tion Fuel Quality Estimation... 

Data required for the modeling purpose are quite sensitive to the selection of the kinetic model and the modeling scope. This work only requires the operation and analysis data measured daily, and Table 6.3 lists the data requirement in this work. We collect the data from March 2009 to June 2009 and organize the data... 

Case studies that encompass real-life optimization scenarios in the refinery Applications that broaden model scope beyond engineering purposes (i.e. refinery production planning)... 

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