Cost criterion/function

Both modes of thermoeconomic analysis, accounting and optimization, are illustrated in example 2, considering a cost criterion function. The case of an energy criterion function may be included as a special case. 

With the system embedded in the economic environment, all the energies and materials of interest are evaluated according to their economic potentials (costs). The criterion function is a cost measure. A typical function rated per unit time is... 

The cost criterion is of course related to the treatment price (PRICE), i.e. the dependent variable of the hedonic price function. PRICE comprises information on both the herbicide price per kilogram and the dose in kilograms per hectare, i.e. PRICE is measured in ITL 1 000 (kITL) per hectare. Annual price data were available for each treatment but, due to the mainly constant nature of the characteristics, PRICE was defined as the mean price of each kill rate period (1987-1988 and 1989-1994) for each treatment. See Table 3.2 for a statistical description of PRICE and the treatment characteristics. 

Since the design/retrofit problem embeds batch plant scheduling, it systematically includes the determination of the production sequence and the equipment sizes based on a performance criterion. Equipment sizes are considered either as continuous variables or as discrete ones and so the problem can involve either discrete variables or a set of mixed ones. Most of the existing literature has focused on single objectives involving a cost criterion typically based on capital investment. This criterion is generally expressed as a non-linear function of the size of the equipment, following the six-tenths rule. 

The threshold. 4nom and the inspection interval At can be obtained by numerical minimisation of the cost criterion of the single-mode deteriorating system in mode Ml. In this work, the cost criterion is optimised as a function of the detection threshold h defined in (4). 

A suitable performance or cost criterion to be optimized. The objective functions that have been used as performance criteria are listed below ... 

This criterion resumes all the a priori knowledge that we are able to convey concerning the physical aspect of the flawed region. Unfortunately, neither the weak membrane model (U2 (f)) nor the Beta law Ui (f)) energies are convex functions. Consequently, we need to implement a global optimization technique to reach the solution. Simulated annealing (SA) cannot be used here because it leads to a prohibitive cost for calculations [9]. We have adopted a continuation method like the GNC [2]. 

The properties of fillers which induence a given end use are many. The overall value of a filler is a complex function of intrinsic material characteristics, eg, tme density, melting point, crystal habit, and chemical composition and of process-dependent factors, eg, particle-si2e distribution, surface chemistry, purity, and bulk density. Fillers impart performance or economic value to the compositions of which they are part. These values, often called functional properties, vary according to the nature of the appHcation. A quantification of the functional properties per unit cost in many cases provides a vaUd criterion for filler comparison and selection. The following are summaries of key filler properties and values. 

The cost functional is the indicator of how well the control loop is functioning. The lAE criterion used essentially says "measure the cumulative difference between the actual value and the desired set point" this cumulative score is a measure of control system performance. With this code in the model, the commands to do the controller tuning are ... 

Various criteria were proposed for the optimal selection of the equipment configuration and the number and sizes of units. In grass-root design, the capital cost of equipment is mostly used as the optimization criterion. In retrofit design a more appropriate objective function seems to be the net profit, which has to be maximized. Papageorgaki and Reklaitis (1993) formulated the criterion as follows ... 

An optimization problem is a mathematical model which in addition to the aforementioned elements contains one or multiple performance criteria. The performance criterion is denoted as objective function, and it can be the minimization of cost, the maximization of profit or yield of a process for instance. If we have multiple performance criteria then the problem is classified as multi-objective optimization problem. A well defined optimization problem features a number of variables greater than the number of equality constraints, which implies that there exist degrees of freedom upon which we optimize. If the number of variables equals the number of equality constraints, then the optimization problem reduces to a solution of nonlinear systems of equations with additional inequality constraints. 

One major advantage of the PMod software is the graphical interface that allows the interactive configuration of the kinetic model by the user as well as the application of some preprocessing steps, e g. setting up initial values and limits for the fit parameters. Visual evaluation of each plot is performed to check the quality of each fit. Each model curve is compared with the corresponding time-activity curve and the total X2 difference was used as the cost function, where the criterion was to minimise the summed squares (X2) of the differences between the measured and the model curve. The distribution at each individual point is taken to be Gaussian, with a standard deviation to be specified. The model parameters are usually accepted when kl-k4 is less than one and the vb value exceeds zero. The unit for the rate constants kl-k4 is 1/min, while vb reflects the fraction of blood within the evaluated volume. 

The primary function of a commercial color formulator is to develop a colorant system that meets a customer s specifications. Occasionally it may not be possible to make the perfect match. In these cases the color formulator should try to find out what criterion—quality (closeness of match) or cost—is the customer s priority. 

Hydrophilicity is an important criterion for the use of synthetic polymers. Existing methods for surface modihcation of synthetic hbers are costly and complex. Therefore, the enzymatic surface modihcation of synthetic hbers is a new and green approach to synthesize polymers with improved surface properties. Use of enzymes for surface modihcation of polymers will not only minimize the use of hazardous chemicals but also minimize the environment pollution load. Besides these, the enzyme-modihed polymers can also immobilize those enzymes which can only bind to the selective functional groups present on the polymeric surface such as —COOH and —NH2. Similarly, substrates can immobilize on the solid matrix (or polymer), which will be easily accessible to the enzymes. Genetic engineering can be employed for the modihcation of active sites of enzymes for better polymer catalysis. 

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