Control objective

Steel was used as the control object. During the experiments radiation energy, steel layer thickness, focal distance, roentgen films, screens were varied. Sensitivity was valued according to wire and groove standards. 

Color Difference Evaluation. Shade evaluation is comparable in importance to relative strength evaluation for dyes. This is of interest to both dye manufacturer and dye user for purposes of quaUty control. Objective evaluation of color differences is desirable because of the well-known variabihty of observers. A considerable number of color difference formulas that intend to transform the visually nonuniform International Commission on Illumination (CIE) tristimulus color space into a visually uniform space have been proposed over the years. Although many of them have proven to be of considerable practical value (Hunter Lab formula, Friele-MacAdam-Chickering (FMC) formula, Adams-Nickerson formula, etc), none has been found to be satisfactorily accurate for small color difference evaluation. Correlation coefficients for the correlation between average visually determined color difference values and those based on measurement and calculation with a formula are typically of a magnitude of approximately 0.7 or below. In the interest of uniformity of international usage, the CIE has proposed two color difference formulas (CIELAB and CIELUV) one of which (CIELAB) is particularly suitable for appHcation on textiles (see Color). 

NOTE As a consequence of the different kinds of operational and management problems associated with raising steam in industrial boiler plants, it often requires a different mindset than that needed for a base-load utility power house, where personnel strive to maintain steady-state (but knife-edge) operating conditions. The differences between industrial plants and power generators is also reflected in the waterside chemistries and monitoring and control objectives of their respective boiler plant systems. 

Optimal control theory, as discussed in Sections II-IV, involves the algorithmic design of laser pulses to achieve a specified control objective. However, through the application of certain approximations, analytic methods can be formulated and then utilized within the optimal control theory framework to predict and interpret the laser fields required. These analytic approaches will be discussed in Section VI. 

Scheme 1 Illustration of the general synthetic method followed in our group for the synthesis of metal nanoparticles i decomposition of the precimsor, nucleation ii first growth process in ripening or coalescence leading to size and shape controlled objects through addition of stabilizers which prevent the full precipitation of the metal (iv)...

Formulation of the control objective for example, the minimisation of some cost function. 

Incident Action Plan A plan which is initially prepared at the first meeting of emergency personnel who have responded to an incident. The plan contains general control objectives reflecting overall incident strategy, and specific action plans. 

Reified actions are often called control objects or transaction objects. Whenever we draw an action ellipse on a type diagram, we are really drawing a type of object, which might or might not be reified in an implementation. (See Pattern 14.13, Action Reification.)... 

Each message will initially arrive at the most appropriate object in the core, which will then delegate some of the work to others. This object is called the control object for that component-level action. 

An even greater pitfall into which many young process control engineers fall, particularly in recent years, is to get so involved in the fancy computer control hardware that is now available that they lose sight of the process control objectives. All the beautifiil CRT displays and the blue smoke and mirrors that computer control salespersons are notorious for using to sell hardware and software can easily seduce the unsuspecting control engineer. Keep in mind your main objective to come up with an effective control system. How you implement it, in a sophisticated computer or in simple pneumatic instruments, is of much less importance. 

The distillation column sketched in Fig. P8.ll has an intermediate leboiler and a vapor sidestream. Sketch a control concept diagram showing the following control objectives ... 

Prepare a control concept diagram that includes the following control objectives ... 

From the above, it is immediately obvious that the main control objective when dealing with AD processes is stability, normally as measured by biogas production rate, effluent soluble COD or VFA concentrations. Therefore, the proposal of control schemes that guarantee the process stability by regulating the effluent soluble COD and VFA is of no doubt. In the next sections, the... 

As was pointed out in previous sections, the main control objective in AD processes is related to guarantee the stable operation of the process, which is also called operational stability [14]. The variables frequently used to monitoring the digester-stability are the biogas production rate and the COD, VFA and alkalinity effluent concentrations. Particularly, VFA are one of the most important intermediaries in the AD process, because their accumulation (generally induced by organic and toxic overloads) may lead to process failure due to the pH-drop they induce and their inhibitory effects in acid form [14, 27]. Thus, the importance of design efficient control systems capable to... 

Anaerobic digester can be controlled by a feedback control law. The main control objective is to regulate the substrate (COD) concentration X4 at any desired value 0 [15]. Indeed, even in face to modeling errors, a control law can be obtained for substrate regulation [35]. Following the ideas reported in [21], since the substrate (COD) concentration X4 is measured, the dilution rate can be computed by [33], [34]... 

Pollution Control Board, Pollution Control Objectives for the Mine, Mine-Milling and Smelting Industries of British Columbia , Province of British Columbia, 1974. 

EDP Auditors Foundation. Control Objectives—1980. Streamwood, IL EDP Auditors Foundation, 1980. 

Although we do not necessarily know the relationships involved in the external world, they do exist and determine the values of the relevant load disturbances. Consequently, we can say that the external world removes as many degrees of freedom as the number of disturbances. In Fig. 7.9 we are introducing a flow control loop to keep F constant, and a temperature control loop with a preheater to maintain qF. The feed composition is fixed by a relationship that we do not know—but all the same must exist. The control objectives are achieved by fitting suitable control systems to the plant and we can say that these control systems remove as many degrees of freedom as the number of control objectives in the overall control strategy. 

From equation 7.10, nf= 8. The feed flow and feed temperature control loops remove two of these and the unknown relationship specifying xf (which may be dependent upon the configuration of a plant upstream) reduces nf again by one—giving nf = 5. Hence, we require five control objectives to specify the system uniquely, i.e. to control it adequately. These will be to maintain xD (as a market requirement) and to control S, Pc, and the levels in the base of the column and the reflux accumulator (for operational feasibility). 

Care must be taken not to specify more control objectives than the available remaining degrees of freedom. If this is done then the system becomes over specified and there is no solution to the system, i.e. the system cannot be controlled. For example, it is impossible to design a control system for the distillation column illustrated in Fig. 7.10 which will control not only Xc S, Pc and the two levels—but also (say) the overhead product flowrate D and the bottoms product flowrate W. 

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