Databases multiple

Values in square brackets are the shift relative to the parent molecule. Numbers in parentheses represent the predicted chemical shift and estimated error. The notation D indicates the structure is in the database. Occasionally a structure can be in the database multiple times with different chemical shifts (see Figure 14.11). The results will be the annotation of a record as contained in the database but a prediction error will be reported. 

For our real estate example, we would like to complete the real estate transaction process more efficiently, especially pertaining to the services provided by agents working within a proprietary database (Multiple Listing... 

This database has some additional commands and search fields, which are tailored to the specific requirements of retrieving spectroscopic data, e.g., peak or multiplicity searches. 

In all of the 3D search methods the conformational flexibility creates considerable difficulties. Large databases of multiple conformations for each structure have been developed which make the solution of this problem possible. 

Comparative QSAR is a field currently under development by several groups. Large databases of known QSAR and 3D QSAR results have been compiled. Such a database can be used for more than simply obtaining literature citations. The analysis of multiple results for the same or similar systems can yield a general understanding of the related chemistry as well as providing a good comparison of techniques. 

Herbicides are also sometimes classified according to mode of action, selectivity, registered uses, and toxicity. The ever-increasing importance of herbicides and other pesticides and agrochemicals to a wide range of users, regulators, and researchers has led to the development of multiple and extensive computer databases. The primary database resources contain collected information relevant to herbicides, and numerous resource pubHcations are available to those needing information on the various aspects of herbicides (2). 

The type of hardware or computer system to be used and the potential size of the database should also be considered. Eor some databases, a personal computer may be adequate. Eor others, especiaUy if there wiU be multiple users, a mainframe computer or a network of personal computers may be required. Storage capacity and response time are parameters that should be considered. However, computer technology changes so rapidly that vendors and computer experts should be consulted when building any personal databases. 

A DBMS performs what is called transaction management. This process allows multiple users to access and store data in the database without cormption. The abiUty to do this is particularly important when data are being written to the DBMS, because power intermptions or hardware failure can cause database transactions to be incompletely processed. Transaction managers use the "all or nothing" principle all the data is written to the DBMS, ie, the transaction is completed, or none of it is written. 

Searching of one or more on-line databases is a technique increasingly used ia novelty studies. The use of such databases enables the searcher to combine indexing parameters, including national and international classifications natural language words ia the full text of patents, ia their claims, or ia abstracts suppHed by iaventor and by professional documentation services and indexing systems of various sorts. Because the various patent databases have strengths and weaknesses that complement each other, the use of multiple databases is thus pmdent, and is faciUtated by multifile and cross-file techniques provided by the various on-line hosts. 

Databases differ in their strengths and weaknesses, as well as in their focus. As a result, dupHcate searches carried out on different databases generally produce different results. This has been demonstrated in comparative studies of retrieval results for a group of patent databases (31,32). Participants in one study (31) made an effort to develop optimal search strategies in each database tested, yet in no instance did one file produce perfect retrieval. Both investigations (31,32) found that results from the various databases complemented each other. As a result, searchers are counseled to use multiple databases whenever possible. There is no pat answer to the question of how many files to use or which files to use however, more files mean more expenditure, and searchers must develop their own cost—benefit relationship. 

Database Records. From 1975 through 1991, database records increased from 52 million to 4.06 biUion, a factor of 77, and the number of databases grew from 301 to 7637, a factor of 24. Database entries grew from 301 to 6261, a factor of 20. The number of producers continues to grow somewhat more slowly in part because individual producers create multiple databases. There were 2372 producers in 1991 and the average producer... 

Many databases can be classified in multiple ways because of multiple type data, eg, text and numeric data, text and image data, image and audio data, etc. Also included in the data presented in Table 1 are two additional classes of databases, electronic services and software. Both of these data types could also be classed by form of representation because of use of words and numbers. However, the way in which these databases are used is different and they have special characteristics. Thus they are presented as additional classes. Whereas electronic information services such as bulletin boards, electronic mail, and electronic conferencing contain data that are transitory and nonarchival, these must be included among databases because several of the principal vendors seU these services in the same way as database search services are sold. 

Databases in CRDB have been coded according to the six classes described (1). Table 1 provides the number and percentage of databases associated with the six database classes. Despite multiple classes assigned to some databases, all classes are normalized to the 6998 database entries in CRDB. Table 2 presents the same data without the normalization. Because a single database entry may have more than one class assignment, there are more database entry-class assignments than database entries in CRDB. 

Table 2. Database Classes Multiple Classes per Database Entry...

Multiple subject categories maybe assigned to a database. Academic. 

The historical data is sampled at user-specified intervals. A typical process plant contains a large number of data points, but it is not feasible to store data for all points at all times. The user determines if a data point should be included in the list of archive points. Most systems provide archive-point menu displays. The operators are able to add or delete data points to the archive point hsts. The samphng periods are normally some multiples of their base scan frequencies. However, some systems allow historical data samphng of arbitraiy intei vals. This is necessaiy when intermediate virtual data points that do not have the scan frequency attribute are involved. The archive point lists are continuously scanned bv the historical database software. On-line databases are polled for data. The times of data retrieval are recorded with the data ootained. To consei ve storage space, different data compression techniques are employed by various manufacturers. 

To overcome the limitations of the database search methods, conformational search methods were developed [95,96,109]. There are many such methods, exploiting different protein representations, objective function tenns, and optimization or enumeration algorithms. The search algorithms include the minimum perturbation method [97], molecular dynamics simulations [92,110,111], genetic algorithms [112], Monte Carlo and simulated annealing [113,114], multiple copy simultaneous search [115-117], self-consistent field optimization [118], and an enumeration based on the graph theory [119]. 

S Henikoff, JG Henikoff, S Pietrokovski. BLOCKS+ A non-redundant database of protein alignment blocks derived from multiple compilations. Biomformatics 15 471-479, 1999. 

Duplicate submissions not identified. Facilities sometimes send multiple copies of the same Form R report to insure that EPA received a copy. Duplicate submissions must be identified by printing the word DUPLICATE" in red Ink on page one in the box marked "THIS SPACE FOR YOUR OPTIONAL USE". Failure to clearly identity a duplicate report may result in the duplicate appearance of the data in the database and the appearance of increased emissions from the facility. 

Has a world-wide database of federal and non-profit environmental research organizations that focus on the multiple aspects of global environmental change, including the regional effects on natural ecosystems, environments and resources as well as on human health, culture and social systems. 

---