Temporal order

Experiments such as these provide an incomparable level of detail on the temporal ordering of elementary processes in a multidimensional collisional environment. To understand the dynamical evolution of many-body systems in terms of the changing forces that act on the interacting... 

B. Handling Constraints on the Temporal Ordering of Operational Goals..337... 

Another important consideration regarding the character of constraints, h,, is their hierarchical articulation at multiple lerels of detail. For example, suppose that one is planning the routine startup procedure for a chemical plant. Safety considerations impose the following constraint on the temporal ordering of operations ... 

Section III introduces the concept of nonmonotonic planning and outlines its basic features. It is shown that the tractability of nonmonotonic planning is directly related to the form of the operators employed simple propositional operators lead to polynomial-time algorithms, whereas conditional and functional operators lead to NP-hard formulations. In addition, three specific subsections establish the theoretical foundation for the conversion of operational constraints on the plans into temporal orderings of primitive operations. The three classes of constraints considered are (1) temporal ordering of abstract operations, (2) avoidable mixtures of chemical species, and (3) quantitative bounding constraints on the state of processing systems. 

This property guarantees that constraints on the temporal ordering of goals are correctly transformed into constraints on the temporal ordering of primitive operations that achieve these goals. 

Clearly, if under the worst-case scenario no node can be found in the IGs that is labeled with all species present in a mixing constraint, then no potential violation of a mixing constraint exists. If, on the other hand, a potential violation has been detected, then we need to generate additional constraints on the temporal ordering of primitive operations so that we can prevent or negate the preconditions of a mixing constraint. 

Once an ASVS has been found, the constraints on the temporal ordering of the valve operations in the ASVS must be established. This is systematically accomplished through an algorithm that undergoes through the following steps. 

In this section we will present a formalized methodology that allows the transformation of quantitative bounding constraints into constraints on the temporal ordering of operators within the spirit of nonmonotonic planning. 

User-specified, temporal ordering of operational goals at higher levels of abstraction is propagated downwards in the hierarchy goals and is ultimately expressed as temporal ordering of primitive operations (see Section III,B). 

Constraints on the disallowed mixtures of chemical species (a) are transformed into temporal orderings of primitive operations, or/ and... 

In this section we will offer several illustrations of the various aspects of nonmonotonic operations planning (discussed in earlier sections) including the following (1) development of hierarchical models for the process and its operations, (2) conversion of constraints to temporal orderings of primitive operations, and (3) synthesis of complete plans. 

If the initial concentrations of the raw material were (in moles per liter), [HCNlo = 1, [H2S04]q = 1.5, and [HCHO]q = 2, then the preceding sequence of operations would immediately have violated Constraint-2, since [HCN] = 1 > 0.1. Similarly, Constraint-3 is violated by the preceding sequence, since [HSO4] = 0 < 1.5. In Section III,D, we discuss the notion of demotion of Clobberers. Let us see how it works here and leads to temporal ordering of operations ... 

Taking (a) and (b) together, we see that Constraints-2 and -3 have been transformed to the following temporal ordering ... 

The following three sequences satisfy all the preceding constraints on the temporal ordering of operations ... 

It is also important to note that abstract operators (AO-1) and (AO-2) are not participating in any temporal ordering constraint. Consequently, they could be placed anywhere in the chain of operations of a procedure. For example, Procedure-A can be completed with (AO-1) and (AO-2) in any of the following ways ... 

FIGURE 18-7 Processing of the proopiomelanocortin (POMC) precursor proceeds in an ordered, stepwise fashion. Cleavage of the POMC precursor occurs at seven sites, with some of the reactions being tissue-specific. The circled numbers indicate the temporal order of cleavage in tissues where these proteolytic events occur. ACTH, adrenocorticotropic hormone CLIP, corticotropin-like intermediate lobe peptide JP, joining peptide LPH, lipotropin MSH, melanocyte-stimulating hormone PC, prohormone convertase. 

Flies and worms. Expression of wild-type and mutant human tau proteins in nerve cells of D. melanogaster and C. elegans led to a reduced lifespan and the loss of nerve cells, in the apparent absence of tau filaments [40, 41]. Phosphorylation of tau was more extensive in the fly than in the worm. In Drosophila, phosphorylation of S262 and S356 in tau by PAR-1 kinase, the fly homologue of MARK, appeared to be necessary for the subsequent phosphorylation at other sites, indicating the existence of a hierarchical and temporally ordered phosphorylation process. 

A natural question is In which temporal order do the reorganization processes and the proper electron transfer take place The answer is given by the Frank-Condon principle, which in this context states First the heavy particles of the inner and outer sphere must assume a suitable intermediate configuration, then the electron is exchanged isoenergetically, and finally the system relaxes to its new equilibrium... 

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