Approach Overview

The data driven approach to supply chain configuration is part of the overall supply chain configuration framework and decision support systems. Within this framework, it emphasizes data gathering and representation of modeling results as well as uses a specific data intensive supply chain configuration model. These key elements of the data driven approach are shown in Fig. 11.1 

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JL Richard. Mycotoxins, toxicity and metabolism in animals a systems approach overview. In M Miraglia, HP van Egmond, C Brera, J Gilbert, eds. Mycotoxins and Phycotoxins—Developments in Chemistry, Toxicology and Food Safety. Fort Collins, CO Alaken, 1998, pp 363-397. 

The decomposition-based approach overviewed in Section 10 was first developed in Ettl et al. (2000) for the purpose of performance evaluation and optimization of a large-scale enterprise supply chain. (Refer to Lee and Billington 1986 for an earlier, related work on modeling supply chains.) A related network model, for semiconductor fabrication, appeared in Connors et al. (1996). Also refer to Buzacott and Shanthikumar (1993) for other network models using decomposition-based approximations. 

In this chapter we review some of the most important developments in recent years in connection with the use of optical teclmiques for the characterization of surfaces. We start with an overview of the different approaches available to tire use of IR spectroscopy. Next, we briefly introduce some new optical characterization methods that rely on the use of lasers, including nonlinear spectroscopies. The following section addresses the use of x-rays for diffraction studies aimed at structural detenninations. Lastly, passing reference is made to other optical teclmiques such as ellipsometry and NMR, and to spectroscopies that only partly depend on photons. 

For larger systems, various approximate schemes have been developed, called mixed methods as they treat parts of the system using different levels of theory. Of interest to us here are quantuin-seiniclassical methods, which use full quantum mechanics to treat the electrons, but use approximations based on trajectories in a classical phase space to describe the nuclear motion. The prefix quantum may be dropped, and we will talk of seiniclassical methods. There are a number of different approaches, but here we shall concentrate on the few that are suitable for direct dynamics molecular simulations. An overview of other methods is given in the introduction of [21]. 

Another approach to obtain an overview on chemical information or on information related to specified topies in chemistry, is to use websites that eontain link lists. These link lists arc usually provided by universities and private persons and are classified into subject areas, Table 5-7 gives an sample of the thousands of link lists in chemistry, and in addition some other valuable URLs that deal with chcmoinformatics. 

J S, I Morize, P R Menard, D L Cheney, C Hulme and R F Labaudiniere 1999. New 4-Point irmacophore Method for Molecular Similarity and Diversity Applications Overview of the thod and Applications, Including a Novel Approach to the Design of Combinatorial iraries Containing Privileged Substructures. Journal of Medicinal Chemistry 42 3251-3264. 

Table 1 provides an overview of many of the techniques available for the characterization of surfaces and interfaces. These techniques are categorized on the basis of the nature of the exciting and detected species (or force). As can be seen by Table 1, a tremendous number of approaches are available for the study of surfaces. In fact, multiple methods capable of answering all of the three questions posed above have been developed over the past thirty years. 

Overview. Three approaches are used to make most sol—gel products method 1 involves gelation of a dispersion of colloidal particles method 2 employs hydrolysis and polycondensation of alkoxide or metal salts precursors followed by supercritical drying of gels and method 3 involves hydrolysis and polycondensation of alkoxide precursors followed by aging and drying under ambient atmospheres. 

A variety of techniques have been introduced to increase the time step in molecular dynamics simulations in an attempt to surmount the strict time step limits in MD simulations so that long time scale simulations can be routinely undertaken. One such technique is to solve the equations of motion in the internal degree of freedom, so that bond stretching and angle bending can be treated as rigid. This technique is discussed in Chapter 6 of this book. Herein, a brief overview is presented of two approaches, constrained dynamics and multiple time step dynamics. 

GR Marshall, CD Barry, HE Bosshard, RA Dammkoehler, DA Dunn. The conformational parameter m drug design The active analog approach. ACS Symp Ser 112 205-226, 1979. YC Martin. Overview of concepts and methods in computer-assisted rational drug design. Methods Enzymol 203 587-613, 1991. 

The Snoek pendulum, which in the most general sense is a device to measure relaxations, has also been used to measure relaxation caused by tangential displacements at grain boundaries. This application has been the central concern of a distinguished Chinese physicist, Tingsui Ke, for all of the past 55 years. He was stimulated to this study by Clarence Zener, in 1945, and pursued the approach, first in Chicago and then in China. This exceptional fidelity to a powerful quantitative technique was recognised by a medal and an invitation to deliver an overview lecture in America, recently published shortly before his death (Ke 1999). 

These four methods suggested by Pedersen serve as a useful starting point for the eonsideration of other approaches and should eertainly not be considered an overview of existing methodology. Nevertheless, this work was pioneering and a good deal of what follows is based to a greater or lesser extent upon it. 

A large number of chiral crowns have been prepared by numerous groups. The reader is directed to the tables at the end of this chapter to obtain an overview of these structures. It would not be useful to try to recount the synthetic approaches used in the preparation of all of these compounds we have chosen rather to subdivide this mass of compounds into three principal groups. The groups are (1) Cram s chiral binaphthyl systems (2) chiral crowns based on the tartaric acid unit and (3) crowns incorporating sugar subunits. These are discussed in turn, below. 

We have not attempted to cover all or even most aspects of crown chemistry and some may say that the inclusions are eclectic. We felt that anyone approaching the field would need an appreciation for the jargon currently abounding and for the so-called template effect since the latter has a considerable bearing on the synthetic methodology. We have, therefore, included brief discussions of these topics in the first two chapters. In chapters 3—8, we have tried to present an overview of the macrocyclic polyethers which have been prepared. We have taken a decidedly organic tack in this attempting to be comprehensive in our inclusion of alkali and alkaline earth cation binders rather than the compounds of use in transition metal chemistry. Nevertheless, many of the latter are included in concert with their overall importance. 

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