Relative control generation

We review briefly the synthesis process leading up to control gen tion  

Precise control implementation. As background for defining a precise control implementation, we describe first our model of the control implementation for the sequencing graph model. We assume a synchronous implementation of control that can be modeled on the whole as a synchronous finite-state machine (FSM) where transitions occur by the ass on of a clock signal at every cycle. The model of synchronous control as a FSM serves as an abstraction to reason about its properties in particular, it does not imply its physical realization in hardware, i.e. the control circuit may be physically implemented either as a single FSM or as a network of FSMs. 

A control FSM is characterized by a set of states called control states. The FSM corresponding to a control implementation of G, is assumed to be initially in the reset state. Because the implementation is assumed to be non-pipelined, the FSM returns to the reset state after the last operation in the graph has completed execution. For a given input sequence, the control delay of the control implementation of G, is the numb of cycles to go from the reset state back to itself. 

More specifically, given a constraint graph G and a relative schedule 12(G), we define a precise control implementation for G as follows. 

Definition 8.0.1 Given a constraint graph G and a relative schedule 12(G), a control implementationfor G is precise w.r.L 12(G) if its control delay is exactly equal to the difference between the sink and source start times, T(v ) — T(vo). computed using the schedule Q G),for all input sequences. 

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Hydrocarbon releases in the petroleum industry are either gaseous, mists or liquids and are either atmospheric releases or pressurized. Gas and mist releases are considered more significant since they are readily ignitable since they are in the gas state and due to the generation of vapor clouds which if ignited are instantly destructive in a widespread nature versus liquid fires that may be less prone to ignition, generally localized and relatively controllable. 

Saturated salt solutions and sulfuric acid solutions establish relative humidity by reducing the vapor pressure above an aqueous solution (a colligative effect). Saturated salt solutions at controlled temperature maintain a constant relative humidity as long as excess salt and bulk solution are present. As water is added or removed from the solution, moisture from the head-space will either condense or evaporate (as appropriate), with subsequent dissolution or precipitation of salt to maintain the equilibrium vapor pressure. Because the degree of vapor pressure depression is dependent on the number of species in solution and, further, since the solubility of most salts is somewhat dependent on temperature, the relative humidity generated is also temperature dependent. Hence, use of the same salt at different temperatures can result in different relative humidities. Refs. can be consulted for specific saturated salt solutions that result in defined relative humidities as a function of... 

The relative ratios of alcohols and carbonyls for the six-, eight- and nine-carbon volatiles in fish (23-24) and oysters (26) parallel those encountered in cucumber fruits (37) and mushrooms (27, 56) if the two systems are combined. Therefore, the use of plant-based enzyme systems for the controlled generation of fresh seafood flavors and aromas has been under consideration in our laboratory as a means to overcome some of the self-inactivating problems associated with fish lipoxygenases. 

Relative control synthesis a control generation approach that synthesizes conux)l circuits from a relative schedule as an interconnection of interacting finite-state machines, and... 

Relative control synthesis. Relative scheduling complicates the task of ctxi-trol generation. When th are no data-dependent delay operations, the schedule consists of a single sequence of control steps that can be synthesized by traditional control strategies. For example, the schedule can be implemented as a microprogrammed controller or as a single finite-state machine. In the general case, however, these traditional control schemes are inadequate. 

For ease of presentation, relative scheduling is first described in Chapter 6, where resource conflicts are assumed to be resolved. Resource conflict resolution by appropriately serializing the operations subject to the timing constraints is presented in Chapter 7. Control generation from relative scheduling is described in Chapter 8. A novel approach to control optimization called resynchronization is described in Chapter 9. 

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