Variable: decisive

Decision variables decision variables representing the planning decisions of the planner and being decided in the optimization model e.g. production volumes... 

This example treats a simple open-cycle gas turbine for which the cost objective function, equations of constraint and costing equations are all available in analytic form. Figure 3 shows these functions along with the fixed and variable decision variables. Since the set of equations is diagonalized,... 

Variances and degrees of freedom Hypotheses Computed value of the Fischer variable Theoretical value of the Fischer variable Decision... 

The demand is modeled using normal distributions and sampling scenarios. The amount ordered in time Tq is considered as a first-stage variable, that is, a decision made before the uncertainty is revealed, whereas the amounts of materials ordered in the next periods, t l, t z and T 3, are considered second-stage variables, decisions made after the uncertainty materialization. 

In this section, the notation in the models is introduced, classified into several categories including static input variables, decision variables, state variables, time uncertainty related variables, quantity uncertainty related variables, dynamic input or derived variables, cost coefficients and performances indicators. 

Similar to the discriminant analysis, decision trees (DTs) are designed to identify patterns characterizng a specified number of disjoint groups, using direct information about the membership of the samples (Quinlan, 1985). While DA generates equations consisting of linear combinations of the variables, decision trees provide branching trees with decisions at each branch point. 

Also in other examples, we observed the same two properties. These two elements seem to be very important if we want to look for a production rule which is simple, but close to optimal. Therefore, we shall propose the following approach, ff the number of orders required for the first period or one of the earlier periods, ri is smaller than a decision variable x, then we do not produce during that period. If ri is equal to or larger than x, then we will produce during that period and we produce all orders with a residual lead time of T periods or less, where T is also a decision variable. Decisions on the production are made at the end of every period, so production may take place less than T periods after the previous one. This rule will be called the (x,T)-nile. 

It should be emphasized that these recommendations for the initial settings of the reactor conversion will almost certainly change at a later stage, since reactor conversion is an extremely important optimization variable. When dealing with multiple reactions, selectivity is maximized for the chosen conversion. Thus a reactor type, temperature, pressure, and catalyst are chosen to this end. Figure 2.10 summarizes the basic decisions which must be made to maximize selectivity. ... 

If distillation is the choice of separator, then some preliminary selection of the major design variables must be made to allow the design to proceed. The first decision is operating pressure. As pressure is raised,... 

At the start of the development, it had been intended use an expert system shell to implement this tool, however, after careful consideration, it was concluded that this was not the optimum strategy. An examination procedure can be considered as consisting of two parts fixed documentary information and variable parameters. For the fixed documentary information, a hypertext-like browser can be incorporated to provide point-and-click navigation through the standard. For the variable parameters, such as probe scanning paths, the decisions involved are too complex to be easily specified in a set of rules. Therefore a software module was developed to perfonn calculations on 3D geometric models, created fi om templates scaled by the user. 

A simple decision-making problem is I measure variable x of a population A and the same variable xof a population B. I get (slightly) different results. Is there areal difference between populations A and B based on the difference in measurements, or am I only seeing different parts of the distributions of identical populations ... 

In attempting to reach decisions, it is useful to make assumptions or guesses about the populations involved. Such assumptions, which may or may not be true, are called statistical hypotheses and in general are statements about the probability distributions of the populations. A common procedure is to set up a null hypothesis, denoted by which states that there is no significant difference between two sets of data or that a variable exerts no significant effect. Any hypothesis which differs from a null hypothesis is called an alternative hypothesis, denoted by Tfj. 

When we draw a scatter plot of all X versus Y data, we see that some sort of shape can be described by the data points. From the scatter plot we can take a basic guess as to which type of curve will best describe the X—Y relationship. To aid in the decision process, it is helpful to obtain scatter plots of transformed variables. For example, if a scatter plot of log Y versus X shows a linear relationship, the equation has the form of number 6 above, while if log Y versus log X shows a linear relationship, the equation has the form of number 7. To facilitate this we frequently employ special graph paper for which one or both scales are calibrated logarithmically. These are referred to as semilog or log-log graph paper, respectively. 

The characteristics of a powder that determine its apparent density are rather complex, but some general statements with respect to powder variables and their effect on the density of the loose powder can be made. (/) The smaller the particles, the greater the specific surface area of the powder. This increases the friction between the particles and lowers the apparent density but enhances the rate of sintering. (2) Powders having very irregular-shaped particles are usually characterized by a lower apparent density than more regular or spherical ones. This is shown in Table 4 for three different types of copper powders having identical particle size distribution but different particle shape. These data illustrate the decisive influence of particle shape on apparent density. (J) In any mixture of coarse and fine powder particles, an optimum mixture results in maximum apparent density. This optimum mixture is reached when the fine particles fill the voids between the coarse particles. 

Among the key variables in strategic alkylphenol planning are feedstock quaHty and availabiHty, equipment capabiHty, environmental needs, and product quahty. In the past decade, environmental needs have grown enormously in their effect on economic decisions. The manufacturing cost of alkylphenols includes raw-material cost, nonraw-material variable cost, fixed cost, and depreciation. 

An important part of planning an experimental program is the identification of the variables that affect the response and deciding what to do about them. The decision as to how to deal with each of the candidate variables can be made jointiy by the experimenter and the statistician. However, identifying the variables is the experimenter s responsibiUty. Controllable or independent variables in a statistical experiment can be dealt with in four different ways. The assignment of a particular variable to a category often involves a trade-off among information, cost, and time. 

The number of independent variables is reduced from the original nine to four. This is a great saving in terms of the number of experiments required to determine the desired function. For example, suppose that a decision is made to test only four values for each variable. Then it would require 4 = 262144 experiments to test aU. combinations of these values in the original equation. As a result of equation 59, only 4 = 256 tests are now required for four values each of the four B-numbers. 

Pairing of Controlled and Manipulated Variables A key decision in multiloop-control-system design is the pairing of manipu-... 

The two key variables in the decision to use steam tracing or electric tracing are the temperature at which the pipe must be maintained and the distance to the supply of steam and a source of electricpower. 

System, Equipment, and Refrigerant Selection There is no universal rule which can be used to decide which system, equipment type, or refrigerant is the most appropriate for a given application. A number of variables influence the finm-design decision ... 

The development of an SC procedure involves a number of important decisions (1) What variables should be used (2) What equations should be used (3) How should variables be ordered (4) How should equations be ordered (5) How should flexibility in specifications be provided (6) Which derivatives of physical properties should be retained (7) How should equations be linearized (8) If Newton or quasi-Newton hnearization techniques are employed, how should the Jacobian be updated (9) Should corrections to unknowns that are computed at each iteration be modified to dampen or accelerate the solution or be kept within certain bounds (10) What convergence criterion should be applied ... 

The decision on whether cathodic protection with impressed current or with magnesium anodes is more economical depends on the protection current requirement and the soil resistivity. This estimate only indicates the basic influence of the different variables. In the individual case, installation costs can vary widely so that a specific cost calculation is necessary for every project. 

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