Knowledge bottleneck

Problem Selection. To select the problem correcdy, the criteria discussed earHer should be carefully appHed before launching a project the existence of a knowledge bottleneck, the inappHcabiHty of exact numerical methods, the existence of either an expert or a theory for the task, the narrowness of the domain, and the business issues of payout and cost. If needed, the various criteria can be quantified and weighted based on their... 

In Chapter 43 the incorporation of expertise and experience in data analysis by means of expert systems is described. The knowledge acquisition bottleneck and the brittleness of domain expertise are, however, the major drawbacks in the development of expert systems. This has stimulated research on alternative techniques. Artificial neural networks (ANN) were first developed as a model of the human brain structure. The computerized version turned out to be suitable for performing tasks that are considered to be difficult to solve by classical techniques. 

In an in depth comparison of the cumulative knowledge discussed in Chapter 3, with what one could extract from the technological results reported in this Chapter, perhaps the first observation that one can make is the difference between the content of the biocatalyst development vs. process development results. The results on biocatalyst improvements constitute the majority of the open literature reports. The most important bottleneck holding advancement of the biodesulfurization technology is the ability to break the second C-S bond, releasing the sulfur from the organosulfur molecules. The IP portfolio does not provide a real solution for that problem. 

Expert systems have been investigated for 20 years. The implementation of expert systems is now being undertaken on a widespread basis, due to the availability of hardware and software tools which alleviate the "knowledge-engineer bottleneck", allowing cost effective implementation. In a similar way, real-time applications of expert systems require tools to allow straightforward implementation. We have presented a software/hardware structure which supports knowledge-base capture and real-time inference for process applications. 

All the necessary tools to develop kinetic models for air-water exchange have been derived already in Chapters 18 and 19. However, we don t yet understand in detail the physical processes which act at the water surface and which are relevant for the exchange of chemicals between air and water. In fact, we are not even able to clearly classify the air-water interface either as a bottleneck boundary, a diffusive boundary, or even something else. Therefore, for a quantitative description of mass fluxes at this interface, we have to make use of a mixture of theoretical concepts and empirical knowledge. Fortunately, the former provide us with information which is independent of the exact nature of the exchange process. As it turned out, the different flux equations which we have derived so far (see Eqs. 19-3, 19-12, 19-57) are all of the form ... 

The first model, the film model by Whitman (1923), depicted the interface as a (single- or two-layer) bottleneck boundary. Although many aspects of this model are outdated in light of our improved knowledge of the physical processes occurring at the interface, its mathematical simplicity keeps the model popular. 

Degree of agreement between average predictions of a model or the average of measurements and the true value of the quantity being predicted or measured. Accuracy is also a criterion used to evaluate the knowledge base uncertainty. It focuses on the identification of the most important bottlenecks in the available knowledge and the determination of their impact on the quality of the result. 

Directed evolution bypasses the bottleneck of rational design and mimics natural evolution in a test tube to evolve proteins without knowledge of their structures. What fundamentally differentiates directed evolution from natural evolution is its power to significantly accelerate the process of evolution. As shown in Fig. 1, directed evolution uses various methods to generate a collection of random protein variants, called a library, at the DNA level. Followed by screening/selection of the library, protein variants with improvement in desired phenotypes are obtained. Usually, the occurrence of these functionally improved protein variants is a rare event thus, this two-step procedure has to be iterated several rounds until the goal is achieved or no further improvement is possible. 

Traders lacked regular supplies of good quality products and that the scale of natmal products operations may be a bottleneck as were the lack of information, lack of capital, low product quality and assurance mechanisms, difficulty in accessing financial credit and loans at reasonable rates, and poor facilities and processing equipment, and little historical investment into this sector. Furthermore, they reported from their survey of the traders themselves that the domestic markets of wholesalers and retailers are largely at low levels of commercialization in general traders have limited technical knowledge about natural products, and limited capital to expand their businesses and exploit... 

The model has certainly many limitations, some related to the status of current knowledge and others due to the lack of appropriate information. It is clear nowadays that sorption/desorption effects play an important role in the actual levels of the concentrations of certain pollutants, depending on the different ambient conditions, but, above all, in the interaction of the mater-ial/substance. The fact is that the values for specific coefficients of adsorption or desorption of a particular chemical substance in a given material are generally unknown. Recent studies have been made in order to obtain the information needed on the sorption/desorption coefficients for different coupling material/substances [29]. So far, that work has only been done for a very limited number of cases. Given the hundreds of substances and materials that can be present, that limitation probably represents the major bottleneck to the wide application of the model. 

Therefore, the role of physicochemical-biological interfacial interactions in controlling the transformation, transport, fate, and toxicity of metals and metalloids in soil and surrounding environments, especially the rhizosphere, which is the bottleneck of contamination of the terrestrial food chain, deserves increasing attention. In this chapter we present an overview of this emerging and extremely important area of science, to advance our knowledge of the interface between physicochemical and biological reactions and processes in the environment. 

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