Conditional query

Queries can either browse the contents of a single table or, using the databases SQL engine, they can perform join conditioned queries that produce result sets involving data from multiple tables that meet specific selection criteria. 

Answers such as / don t know should also be taken into account. Classification queries are a particular case of universal queries and of existential queries, namely when there are no variables in A. Universal queries are a particular case of conditional queries, namely when C reduces to true. Similarly to our assumption about the consistency of specifications with intended relations, we assume that the specifier s answers to queries are noise-free. Note that we talk about questions to a (human) specifier here, and not about the more general problem of asking questions to some oracle. At this level of the discourse, we are not interested in knowing whether a mechanized oracle is queried during synthesis or not. 

Direct property prediction is a standard technique in drug discovery. "Reverse property prediction can be exemplified with chromatography application databases that contain separations, including method details and assigned chemical structures for each chromatogram. Retrieving compounds present in the database that are similar to the query allows the retrieval of suitable separation conditions for use with the query (method selection). 

This is a question of reaction planning. To answer such a problem reagents and reaction conditions have to be found that allow one to perform the desired transformation. Such a question is best answered by a query into a reaction database (see Section 5.12). 

Data queries for chromatographic data, literature references, analytical conditions... 

Today, the use of CHIRBASE as a tool in aiding the chemist in the identification of appropriate CSPs has produced impressive and valuable results. Although recent developments diminish the need for domain expertise, today the user must possess a certain level of knowledge of analytical chemistry and chiral chromatography. Nevertheless, further refinements will notably reduce this required level of expertise. Part of this effort will include the design of an expert system which will provide rule sets for each CSP in a given sample search context. The expert system will also be able to query the user about the specific requisites for each sample (scale, solubility, etc.) and generate rules which will indicate a ranked list of CSPs as well their most suitable experimental conditions (mobile phase, temperature, pH, etc.). 

This assignment was queried [16-18] and detailed investigations [19a] showed that the principal originator of this spectrum is the 3-(l-methyl, 3-phenylindanyl) cation (I), and that, according to the conditions of the experiment, other ions of the diphenylmethyl type may contribute. The spectrum of the 1-phenylethyl ion has still not been identified but that of the homologous 1,3-diphenyl-n-butyl cation (II) was shown to have only a single important absorption, at 315 pm [19a]. 

The unit of a wrapper with its associated program or database query is called an analyzer. Analyzers are often highly specific. The correctness of their results depends partially on certain conditions, such as the taxonomic specification. Annotation added by an analyzer is often in turn exploited by other analyzers executed later. EDITtoTrEMBL uses the conditions, which are stored in the RuleBase, for the execution of analyzers. Dispatchers, programs that coordinate the flow of entries between different analyzers, evaluate these conditions. 

Both DIVA and RS3 provide some functionality in terms of substructure searches (SSS), although it is somewhat limited. For example, DIVA searches can only be performed on data that have already been queried from the database ). This pre-queried data need to be readily available to DIVA either via RS3 or as an SD file. In the case of RS3, the inclusion of multiple data sources (e.g., searching the corporate database and an external vendor library) is not trivial. As a result, while DIVA and RS3 are very useful for SSS under certain conditions, they are not as robust when compared to the Pipeline Pilot protocol. 

Fig. 2. WEB representation of SEVENS database. At the upper part (Fig. 2a), the chromosomal viewer, the phylogenetic map button, and the content search boxes are shown. Using the AND combinations of several conditions, the content search boxes retrieve GPCR genes. Selection of a query gene from these viewers or the list table navigates the user to the gene annotation information page.

In one operational mode, the system pw is established by a large sample and is characterized by the sensor. The amount of moisture transfer from the sample does not significantly change its moisture content. The sensor is queried to identify its condition, and the result is converted into an estimation of pw. 

The refinement procedure utilises the fact that if some query node Q(X) has another node Q(fV) at some specific distance ) ( and/or angle), and if some database node D(Z) matches with Q(W), then there must also be some node D(Y) at the appropriate distance(s) from D(Z) which matches with Q(X) this is a necessary, but not sufficient, condition for a subgraph isomorphism to be present (except in the limiting case of all the query nodes having been matched, when the condition is both necessary and sufficient). The refinement procedure is called before each possible assignment of a database node to a query node and the matched substructure is increased by one node if, and only if, the condition holds for all nodes W, X, Y and Z. The basic algorithm terminates once a match has been detected or until a mismatch has been confirmed [70] it is easy to extend the algorithm to enable the detection of all matches between a query pattern and a database structure, as is required for applications such as those discussed here. 

At the very bottom level of most structure handling algorithms two structures are compared atom by atom and bond by bond (ref. 1). However, the preprocessing steps, the I/O conditions, the constraints in the query or in the reference structures, and requirements for a match or failure differ considerably from application to application. The most frequent used structure manipulating procedures are substructure and superstructure searches. 

The specific heat, cp, of the fluid with which the body is exchanging heat. The reason for using the specific heat at constant pressure may be queried. For liquids, which may be assumed to be incompressible under the conditions here being con-sidered, all specific heats are the same. For gases, cp is used basically because it is the changes of enthalpy of the fluid that are of importance and the enthalpy of the fluid per unit mass at any point is cpT. 

It was appreciated at the outset that the characterization of these materials would be an altogether more difficult problem than that of EUROPT-1, by reason of the lower metal content, and the bimetallic nature of EUROPT-4. It was hoped that study of the latter would help resolve some of the questions concerning the intimacy of mixing of the two metals in the functioning catalyst, but these queries have been only partially answered. Temperature programmed reduction (TPR) studies have confirmed the sensitivity of the reduction profile to experimental conditions and sample pretreatment but, notwithstanding reports in the liter-... 

A subtle, but no less profound effect of this completely new approach is in the way chemists handle the vocabulary of their profession, a knowledge of possible chemical transformations. It could be said that it will become less important to memorise lists of synthetic methods, but this creates a problem. Computer reaction databases are only as good as the questions we ask them, and without a sound knowledge of what is chemically feasible, we cannot construct a query to obtain the exact reaction conditions we need. 

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