End-User

If the gas purchaser is a company which distributes gas to domestic and industrial end users, he typically wants the producer to provide... 

Apart from the cost of knowledge acquisition, another disadvantage of rule-based systems is the difficulty of rule-base maintenance. Rule-base maintenance may be required when changes are made to the inspection system, the inspection procedures, or if differing constructions are inspected. The maintenance usually cannot be done by end-users. 

The end users of CBR systems should in principle be able to maintain the case-bases themselves and use the systems for varying inspection types (within certain limits). Adaptation of neural-network based systems, though possible by end-users, is difficult to be done reliably. Adaptation of rule-based systems usually has to be done by the rule-base designer. 

There are a number of different ways that the molecular graph can be conununicated between the computer and the end-user. One common representation is the connection table, of which there are various flavours, but most provide information about the atoms present in the molecule and their connectivity. The most basic connection tables simply indicate the atomic number of each atom and which atoms form each bond others may include information about the atom hybridisation state and the bond order. Hydrogens may be included or they may be imphed. In addition, information about the atomic coordinates (for the standard two-dimensional chemical drawing or for the three-dimensional conformation) can be included. The connection table for acetic acid in one of the most popular formats, the Molecular Design mol format [Dalby et al. 1992], is shown in Figure 12.3. 

Several important generalizations can be made. The first is that fossil fuel prices are primary competition for biomass energy. Table 28 summarizes 1990 U.S. tabulations of average, consumption-weighted, deflvered fossil fuel prices by end-use sector (90). The deflvered price of a given fossil fuel is not the same to each end user ie, the residential sector normally pays more for fuels than the other sectors, and large end users pay less. 

Table 28. U.S. Delivered Fossil Fuel Prices to End Users, 1990, /GJ ...

In 1981, IBM introduced a low cost PC, which provided avenues for access to on-line databases by end users. In 1986 the president of Dialog noted that, although 85% of DIALOG S customers were information speciaHsts or Hbrarians, 80% of new DIALOG accounts were estabHshed for end users (18,19). Users wanted the on-line industry to accommodate their needs and expectations, but the on-line industry did not recogni2e that the availabiHty of large amounts of on-line information would not, of itself, induce people to use the information. 

Existence of the end user was recognized in the 1980s it was not until the 1990s that vendors made concerted efforts to accommodate end user needs by providing faster, easier, and more powerhil ways to retrieve relevant information. In electronic information retrieval, the term accessibiUty implies that data exist in electronic form, that data retrieval is cost effective, intuitive, and easy, and that the electronic medium contributes to the quaUty and usabihty of the information (27). 

In order to estabUsh this type of service, the maintenance management should meet often with their outside suppHer as weU as with their iaside customers to benefit the end user the external customers. During these meetings the foUowiag steps should be taken to assure nonstop quahty Hsten to the customers, work with customers to clarify expectations, identify measurable iadicators, exceed expectations, deUver products and services when customers need them, keep promises, design for ease of use, constandy improve, focus improvements on areas related to customer expectations, and respond quickly (5). 

The advent of a large international trade in methanol as a chemical feedstock has prompted additional purchase specifications, depending on the end user. Chlorides, which would be potential contaminants from seawater during ocean transport, are common downstream catalyst poisons likely to be excluded. Limitations on iron and sulfur can similarly be expected. Some users are sensitive to specific by-products for a variety of reasons. Eor example, alkaline compounds neutralize MTBE catalysts, and ethanol causes objectionable propionic acid formation in the carbonylation of methanol to acetic acid. Very high purity methanol is available from reagent vendors for small-scale electronic and pharmaceutical appHcations. 

The neat resin preparation for PPS is quite compHcated, despite the fact that the overall polymerization reaction appears to be simple. Several commercial PPS polymerization processes that feature some steps in common have been described (1,2). At least three different mechanisms have been pubUshed in an attempt to describe the basic reaction of a sodium sulfide equivalent and -dichlorobenzene these are S Ar (13,16,19), radical cation (20,21), and Buimett s (22) Sj l radical anion (23—25) mechanisms. The benzyne mechanism was ruled out (16) based on the observation that the para-substitution pattern of the monomer, -dichlorobenzene, is retained in the repeating unit of the polymer. Demonstration that the step-growth polymerization of sodium sulfide and /)-dichlorohenzene proceeds via the S Ar mechanism is fairly recent (1991) (26). Eurther complexity in the polymerization is the incorporation of comonomers that alter the polymer stmcture, thereby modifying the properties of the polymer. Additionally, post-polymerization treatments can be utilized, which modify the properties of the polymer. Preparation of the neat resin is an area of significant latitude and extreme importance for the end user. 

Do we recognize that key inventions are often made here Do we learn from our lead end users (39) ... 

After mixing, doughs are immediately divided and rounded, rested briefly, then molded. Molded units are rapidly fro2en ia blast (or other) free2ers uatil reaching a core temperature of about —7 to —5°C. Units are boxed and stored at — 18°C, then shipped to end users. End users slowly thaw these products in 2°C retarders over 16—18 h, proof, and bake the products as needed (37—41). 

Olefin polymerization catalysts are unique in their utilization of supported catalysts in that the catalysts that have been developed are so highly active that the spent catalysts are intentionally left in the polymer where, at the extremely low parts per million concentrations used, they pose no threat to the properties of the polymer or to the well-being of the end user. 

The initial uses of colorants in plastics were as extenders and additives. Carbon black and titanium dioxide were and are stiU used as fillers (qv) because of their low cost. Almost from plastics inception the limitation of black and white did not offer sufficient color choices for end users looking to differentiate their products. The increase in aesthetic requirements along with different performance requirements and resin compatibiUties led to a great expansion in the number of different chemical classes of colorants and forms in which these colorants are available in today s market. 

There are vastly more complex examples of difficult vectorization decisions. A great deal of effort has been devoted to writing vector code, or code that compilers can safely translate into vector instmctions. As compilers become more sophisticated, their ability to recognize vectorization opportunities increases. The vendors of vector computers often claim that vectorization is automatic and that end users need not be concerned with it. This claim is usually tme only if the end user is similarly unconcerned with achieving maximum performance. More often than not, codes that have not been written for vector architecture machines must undergo substantial restmcturing in order to achieve significant performance enhancements on vector-architecture machines. 

The I I cleaning procedures as a whole, compared with household laundering, are characterized by huge variations in the composition of the soils, types of surface to which they adhere, cleaning time available, etc. The optimum choice of enzyme type and dosage level normally has to be established through a cooperation between the customer (end user), manufacturer of the detergent, and enzyme producer. 

The performance of a controller depends as much on its tuning as its design. Tuning must be apphed by the end user to fit the controller to the controlled process. Tnere are many different approaches to controller tuning based on the particular performance criteria selected. 

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