Run-time logic

Firstly, there are technical reasons concerning catalyst and reactor requirements. In the chemical industry, catalyst performance is critical. Compared to conventional catalysts, they are relatively expensive and catalyst production and standardization lag behind. In practice, a robust, proven catalyst is needed. For a specific application, an extended catalyst and washcoat development program is unavoidable, and in particular, for the fine chemistry in-house development is a burden. For coated systems, catalyst loading is low, making them unsuited for reactions occurring in the kinetic regime, which is particularly important for bulk chemistry and refineries. In that case, incorporated monolithic catalysts are the logical choice. Catalyst stability is crucial. It determines the amount of catalyst required for a batch process, the number of times the catalyst can be reused, and for a continuous process, the run time. 

When the user clicks on an identified concept the UltraLink creation process is called and displays a menu of possible links. Figure 31.2C shows the list of links that are generated at run time when the user clicks on Psoriasis (second document in the hit list in Fig. 31.2A), which has been classified as a disease. It can clearly be seen how the internal logical structures from the previous section are exposed to the user when calling the UltraLink (Fig. 31.2, B and C). 

Click the OK button and then run the simulation. It will take three times as long as the previous simulation because the Transient Analysis will run three times. Logically, the Transient Analysis runs inside the Temperature Sweep. For this example, the temperature will be set to -25°C, and then the Transient Analysis will be run. Next, the temperature will be set to 25°C, and then the Transient Analysis will be run. Finally, the temperature will be set to 125°C, and then the Transient Analysis will be run. 

Interlock 1 is also provided with rotating sequencer logic, which serves to equalize run times between machines and protects the same machine from being started and stopped too frequently. A simple approximation of these goals is achieved if the machine that operated the longest is stopped and the one that was idle the longest is started. 

Synthesis run-times, mainly logic optimization, are exponential with design size. Thus it is critical to keep the sizes of sub-blocks within a design manageable. 

Sometimes our first separation will be adequate. More often we will want to improve resolution, while holding separation time (run time) to a minimum. Assuming that resolution must be improved, the next step should be to optimize the gradient range. However, this can logically be combined with a following step (options 4-6 of Table 1) in improving the separation. 

The External model allows the user to create, in a Python file (imported, at run-time, in the RAVEN framework), its own model (e.g. set of equations representing a physical model, connection to another code, control logic, etc.). This model will be interpreted/used by the framework and, at runtime, will become part of RAVEN itself... 

VHDL defines logical operators for the basic types of BIT and BOOLEAN or any one-dimensional array of either type, such as BIT VECTOR. The result generated by each operator is of the same type and has the same length as the operands supplied. Hence, the operands must be identical in type and length to allow each matching element to be compared. The synthesizer should detect any errors of this t)rpe, but they may go undetected until run time when simulating the description. The operators are listed in Table 4.1. 

A simulation model has entities (e.g. machines, materials, people, etc.) and activities (e.g. processing, transporting, etc.). It also has a description of the logic governing each activity. For example, a processing activity can only start when a certain quantity of working material is available, a person to run the machine and an empty conveyor to take away the product. Once an activity has started, a time to completion is calculated, often using a sample from a statistical distribution. 

The model is started and continues to run over time, obeying the logical rules that have been set up. Results are then extracted concerning throughputs, delays, etc. 

Note that there are no curly brackets around the parameter. Click the OK button to accept the value and return to the schematic. Logically, the Transient Analysis executes inside the Parametric Sweep. That is, for each value of the parameter, the Transient Analysis is run. Thus, for this setup, ten Transient Analyses will be run. Since we chose a small Maximum time step in the Transient Analysis setup, this simulation will take a long time to run. To speed up the simulation, you may want to increase the value of the Maximum time step. 

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