Model-based synthesis

Model-Based Synthesis of Fault Tree Analysis... 

Y. Papadopoulos, M. Maruhn, Model-based Synthesis of Fault Trees from Matlab -Simulink Models. 

In Chapter 3, we survey the use of inductive inference in automatic programming. Specifications by examples are concise and natural, but are usually also incomplete and ambiguous, due to the insufficient expressive power of examples. As inductive inference is much less known than deductive inference, we first survey this field. Inductive synthesis from specifications by examples can be classified into trace-based synthesis and model-based synthesis. We survey the achievements of inductive synthesis of LISP functions and Prolog predicates. 

Papadopoulos, Y., Maruhn, M. Model-based synthesis of fault trees from matlab-simulink models. In International Conference on Dependable Systems and Networks, DSN 2001, pp. 77-82 (2001)... 

The theoretical approach involved the derivation of a kinetic model based upon the chiral reaction mechanism proposed by Halpem (3), Brown (4) and Landis (3, 5). Major and minor manifolds were included in this reaction model. The minor manifold produces the desired enantiomer while the major manifold produces the undesired enantiomer. Since the EP in our synthesis was over 99%, the major manifold was neglected to reduce the complexity of the kinetic model. In addition, we made three modifications to the original Halpem-Brown-Landis mechanism. First, precatalyst is used instead of active catalyst in om synthesis. The conversion of precatalyst to the active catalyst is assumed to be irreversible, and a complete conversion of precatalyst to active catalyst is assumed in the kinetic model. Second, the coordination step is considered to be irreversible because the ratio of the forward to the reverse reaction rate constant is high (3). Third, the product release step is assumed to be significantly faster than the solvent insertion step hence, the product release step is not considered in our model. With these modifications the product formation rate was predicted by using the Bodenstein approximation. Three possible cases for reaction rate control were derived and experimental data were used for verification of the model. 

For targets that lack structural information, such as GPCRs or ion channels, a pharmacophore model or multiple pharmacophore models for different series of compounds can explain SAR and guide the synthesis of new analogs. Alternatively, homology models based on bacteriorhodopsin have been used to explain the interactions of small molecules with GPCRs. 

Model-based) Direct synthesis For a given system, synthesize the controller function according to a specified closed-loop response. The system time constant, xc, is the only tuning parameter. 

It should be noted that most of the substitution-based synthesis work with poly(organophosphazenes) has been preceded by exploratory studies at the small molecule, model compound level, often with the use of cyclic trimer I as a model for polymer II (6). 

A kinetic model based on the Flory principle is referred to as the ideal model. Up to now this model by virtue of its simplicity, has been widely used to treat experimental data and to carry out engineering calculations when designing advanced polymer materials. However, strong experimental evidence for the violation of the Flory principle is currently available from the study of a number of processes of the synthesis and chemical modification of polymers. Possible reasons for such a violation may be connected with either chemical or physical factors. The first has been scrutinized both theoretically and experimentally, but this is not the case for the second among which are thermodynamic and diffusion factors. In this review we by no means pretend to cover all theoretical works in which these factors have been taken into account at the stage of formulating physicochemical models of the process... 

In conclusion, we present in this communication an alternative method for optimizing homogeneous catalysts. This concept is based on iterative modelling and synthesis steps. We do not claim to replace serendipity in catalyst discovery and optimization using this approach. Rather, we believe that this approach can complement serendipity by steering synthetic chemists clear from null regions of the catalyst space. 

Investigating the kinetically controlled synthesis of the /flactam antibiotic amoxicillin from 6-aminopenicillanic acid and D-p-hydroxyphenylglycine methyl ester in a solid suspension system in which the reaction nevertheless occurred in the liquid phase, Diender et al. found that the pH value and dissolved concentrations took a very different course at different initial substrate amounts (Diender, 2000). These results were described reasonably well by the model based on mass and charge balances, pH-dependent solubilities of the reactants, and enzyme kinetics. 

Since computational power has increased enormously in personal computers, and since there is a strong need for maximal compression of multimedia, especially over the internet, it seems reasonable to expect future growth in the development of model-based sound synthesis. Model-based image generation and algorithmic sound synthesis are already under consideration for the MPEG-4 compression standard. 

Physics-based synthesis can provide extremely high quality and expressivity in a very compact algorithm. Such computational models can provide extremely low bit rates at very high quality levels for certain sounds. In addition to data compression applications, such models can also provide a foundation for the future evolution of musical instruments, moving it from the real world of wood and metal into the virtual world where formerly impossible modifications are easily tried out. 

Depalle, 1991] Depalle, P. (1991). Analyse, Modelisation et synthese des sons basees sur le modele source-filtre (Analysis, Modelling and synthesis of sounds based on the source-fdter model). PhD thesis, Universite du Maine, Le Mans, France, (in French). 

Haufler, R. E. et al. 1991 Carbon arc generation of C60. Mater. Res. Soc. Proc. 206, 627-638. Heath, J. R. 1991 Synthesis of C60 from small carbon clusters a model based on experiment and theory. In Fullerenes synthesis, properties, and chemistry of large carbon clusters (ACS Symp. Ser., no. 481) (ed. G. S. Hammond V. J. Kuck), pp. 1-23. Washington, D.C. American Chemical... 

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