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Some Choices

The choice of parameterization and the design of a discretization method are not independent Some choices of parameters will facilitate symplec-tic/reversible discretization while others may make this task very difficult or render the resulting scheme practically useless because of the computational expense involved. [Pg.351]

Equation (3.43) only determines the ratio AjB and does not specify the absolute values of the rate constants, hence some choice must be made based on the physical processes involved. This problem is referred to as apportioning and has often... [Pg.260]

Although a wide choice for the other parameters occurring in Eqs. (3.64) and (3.65) is possible, their temperature dependence is small in the vicinity of T°. In practice either G/p or log (G/P) is normally plotted as some function of temperature which necessarily entails some choice for these parameters. Each case should be examined individually to ascertain the change a different choice would make, and to only rely on the results within these limits. [Pg.264]

The analyst does have some choice of the ionization method to be used El, Cl and FAB are available, subject to certain limitations, and thus both molecular weight and structural information may be obtained from the analyte(s) under investigation. [Pg.139]

The definition of well-posedness and ill-posedness of a scheme is closely connected with the selection rules for norms II j and (-2,)- It niay happen that for some choices of these norms estimate (25) is fulfilled, while... [Pg.128]

Let II II denote the Euclidean norm and define = gk+i gk- Table I provides a chronological list of some choices for the CG update parameter. If the objective function is a strongly convex quadratic, then in theory, with an exact line search, all seven choices for the update parameter in Table I are equivalent. For a nonquadratic objective functional J (the ordinary situation in optimal control calculations), each choice for the update parameter leads to a different performance. A detailed discussion of the various CG methods is beyond the scope of this chapter. The reader is referred to Ref. [194] for a survey of CG methods. Here we only mention briefly that despite the strong convergence theory that has been developed for the Fletcher-Reeves, [195],... [Pg.83]

The form of the solutions that one obtains for reactions of this type is dictated by the relative values of the four reaction orders. For some choices of these orders it is not possible to obtain simple closed form solutions to these rate equations unless one places additional restrictions on the initial composition of the reaction mixture. The three possible-cases are discussed below. [Pg.143]

However, what we can say is that if (P,I) is partially correct with respect to A and B, then some choice of inductive assertions will work - there are inductive assertions (but we may of course not be able to find them) which assigned to the A, make V X V Y W(P,A,B,I) true. [Pg.162]

Now we have a method that is both necessary and sufficient to demonstrate partial correctness. We have already seen that if these verification conditions all hold, then the program is indeed partially correct for the given criteria. The arguments used in Chapter V can be adapted to show that if partial correctness holds, then some choice of inductive assertions will make the verification conditions true. [Pg.290]

Figure 4.3 Deciding how much validation is required-some choices. Figure 4.3 Deciding how much validation is required-some choices.
The states are as you choose them. By a state in a statechart, we mean the truth or falsity of some predicate i.e. just like any boolean attribute, including parameterized attributes as well. A library book is or isn t out on loan it is or isn t withdrawn from circulation it is or isn t on the shelf. Some choices of states are obvious, because they make a significant difference to the postconditions and preconditions of the applicable operations. The point of a statechart is to illustrate these broad relationships between state and actions. But depending on your point of view, you can always choose a different set of states to illustrate — whether the book is or isn t in poor repair, whether it is over 10 years old, whether it is currently passing through the checkout desk, whether it is overdue for return. [Pg.625]

Although every g-density in the Slater hull is A-representable, not every g-matrix that satisfies the Slater hull constraints is A-representable. That is, if Pii...iQ =, g ,j satisfies the (g, K) conditions, some choices for the off-... [Pg.465]

Finally, the analyst is left with some choice in the strategy that can be used In the analysis by way of the chromatographic media selected, and in the level of some operating variables that may be considered appropriate or necessary. The range of variables left to the choice of the analyst constitutes the the third data base necessary for optimum column design and this will be termed the elective variables. However, as most of the conditions that need to be specified will be defined under performance criteria and determined under instrument constraints, the analyst is not left with a very wide choice of variables from which to choose. This might be considered advantageous, however, as the fewer the decisions that are left in the hands of the operator, the less skill and experience will be required and fewer mistakes will be made. [Pg.176]

The central atom is usually the one that can form the most bonds, which is often the atom with the most empty valence orbital slots to fill. For larger molecules, this step may involve some trial-and-error, but for smaller molecules, some choices are obviously better than others. For example ... [Pg.64]

Clients should have some choice—there should be enough services available to enable clients to choose between at least two different types of help. [Pg.173]

Both the chronology and the nature of the action of a drug are unmistakably apparent. But you still have some choice as to whether you will accept the adventure, or rather just continue with your ordinary day s plans (if you are an experienced researcher, that is). The effects can be allowed a predominant role, or they may be repressed and made secondary to other chosen activities. [Pg.266]

We have seen in the previous section that the definition of a set of OjS is intimately bound up with some choice of function space. The reader is cautioned, however, that not all function spaces can be used to define OjjS appropriate for a given point group. For example, the functions cosXi, sinx cosx and sinx, do not forma basis for a representation of the (symmetric tripod) point group xl and xt are the coordinates introduced before (see Fig. 5-2.2). [Pg.91]

In the steps leading to Eq. 6.5, the choice of the Nth component is arbitrary, and a different set of values for the four interdiffusivities will be obtained for each choice. However, each set leads to the same physical behavior predicted for the system the diffusion profiles of the three components predicted by the equations are independent of the choice for N3 For some choices, the interpretation of interdiffusivities in terms of kinetic and thermodynamic data may be more straightforward [1]. [Pg.134]

TTomogeneous catalysis has made considerable progress in the past decade. Even so there is still uncertainty as to the detailed mechanism of many catalytic reactions. This is particularly true of Pd (II) catalysis. The advances in organic synthesis by Pd (II) catalytic chemistry have been impressive a recent review (I) of two volumes had few references before 1963. However the advances have mainly been in synthetic chemistry, and relatively little effort has been expended on studies of mechanism in this chemistry. To fill this gap we have undertaken a systematic study of the basic mechanisms of Pd (II) catalysis. Some choice of the many catalytic reactions available for study had to be made. For several reasons the reactions chosen for initial study were olefin oxidation and exchange reactions of vinylic and allylic esters and chlorides. Work has concentrated on the PdCl2-NaCl or LiCl systems in... [Pg.42]

One advantage of liposome is theirsingularability to take up material of all shapes and sizes regardles of their individual chemical peculiarities. The most relevant to this discussion is for lipid-soluble compounds, which are incorporated into the lipid bilayer of the liposome. Thus, the maximum amount taken up into liposomes is directly proportional to the quantity of membrane components, but is independent of the size of the liposomes used, except in a few cases where the structure o the encapsulated compound may restrict the Lnal size of the liposome. Theoretically, any type of liposome is suitable for the incorporation of lipid-soluble substances, but practical considerations make some choices more preferable over others. MLVs are the best choice for sustained release whereas SUVs are particularly suitable for rapid intermembrane transfer. [Pg.398]

Retirees have experience, knowledge, and skills that society needs. They constitute a giant reservoir of ability and talent. But finding the right part-time job is not always easy. It is estimated that for every two retirees who work part-time, at least one more person would like to work. With Plan B, you have some choices. For example, you can continue to use skills you already possess or learn to do something fresh and different. Here are some ideas to consider. [Pg.75]

In this book we use SI units and IUPAC symbolism and terminology as far as possible. The complete set of notation used in this book is given before this chapter. For clarity and consistency we have made some choices of notation that differ from IUPAC recommendations. Notation is defined where first introduced. Amongst other exceptions is the use of the phrase amount of substance for the variable n, which has been traditionally called the number of moles or, as we most frequently call it, the mole numbers. Some basic reference tables are given in the appendices. [Pg.5]

Some choice between the two possible mechanisms can be made by studying the periodate oxidation of pinitol,66 sequoyitol,78 and profo-quercitol.79 If a methylene (deoxy) or an O-methyl group should occur at C3 or C4 of the hexodialdose, the rapid periodate oxidation of the cyclic form XXXVI would end after the consumption of only 2 or 3 moles of periodate per mole, respectively, and would then continue only at the very slow rate governed by the hydrolysis of the formate ester. The above compounds give hexo-dialdoses of this nature, but they rapidly consume some four moles of periodate per mole. This indicates that the major path of the reaction is not the one by way of cyclic intermediates this conclusion is probably valid for the inositols, too. [Pg.152]

Some choices will correct or improve the original problem, if there is one. Some will continue to make the same mistake and/or introduce new ones. Only one choice will be both grammatically correct and the most clear and concise way to express the idea. [Pg.32]


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