Historical database

These tests generate several Gigabytes of data that are fed into a historical database. Although most of the analysis is performed automatically, human interaction is still needed to compare current and past data. Data are stored on optical CD S s from which the historical data bank are retrieved during field inspections from a mobile unit. Each of these is equipped with a CD-jukebox linked to an analysis station. The jukebox can handle 100 CD s, enough to store all previously recorded data. A dedicated software pre-fetches the historical data and compares it on-line with the newly acquired NDT-data. It is based on fuzzy algorithms applied to signal features. 

Using CD s streamlines the automatic comparison of data. Because of their large storage capacity and their reduced dimensions CD s provide a complete historical database for all steam generator tubes from a mobile inspection platform. 

Mass storage device. Typically, fixed-head hard disk drives are used to store ac tive data, including on-line and historical databases and non-memory-resident programs. Memory-resident programs are stored to allow loading at system startups. The tape drives are used for archives and backups. 

Historical DataBase Subsystem We have discussed the use of on-hne databases. An historical database is built similar to an on-line database. Unlike their on-line counterparts, the information stored in a historical database is not normally accessed directly by other subsystems for process control and monitoring. Periodic reports and longterm trends are generated based on the archived data. The reports are often used for long-term planning and system performance evaluations such as statistical process (quality) control. The trends may be used to detect process drifts or to compare process variations at different times. 

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. 

Because component-based analysis of PCBs has limited the usefulness of the historical database for current environmental research and in formulation of regulatory criteria, procedures were... 

Comparison of mutation frequencies is made with the historical database. For definition of a positive result the same principles are recommended as for the mouse spot test (Selby and Olson, 1981). A minimum size of 18,000 offspring per group is recommended by those authors for definition of a negative result. 

Aberration yields in negative and positive controls should be used to provide a historical database. 

Whole body Variety and number of animals Chronic studies possible Minimum restraint Large historical database Controllable environment Minimum stress Minimum labor Messy Multiple routes of exposure skin, eyes, oral Variability of dose Cannot pulse exposure easily Poor contact between animals and investigators Capital intensive Inefficient compound usage Difficult to monitor animals during exposure Cleaning effluent air Inert materials Losses of test material Even distribution in space Sampling Animal care Observation Noise, vibration, humidity Air temperature Safe exhaust Loading Reliability... 

The endpoint measurement of the ideal test system must be objective, so that a given compound will give similar results when tested using the standard test protocol in different laboratories. If it is not possible to obtain reproductive results in a given laboratory over time or between various laboratories, then the historical database against which new compounds are evaluated will be time- and laboratory-dependent. Along these lines, it is important for the test protocol to incorporate internal standards to serve as quality controls. Thus, test data could be represented utilizing a reference scale based on the test system response to the internal controls. Such normalization, if properly documented, could reduce intertest variability. 

The increased interest in Mo and W due to commodity price increases since 2006 has created a need for a synthesis of information on known deposits and potential exploration environments within the province of Newfoundland and Labrador. This review is drawn from the historical database of exploration and scientific studies, but it also provides some essential geological information concerning recent exploration developments in Newfoundland. Further information is provided in a recent article by Kerr et al. (2009). Molybdenum mineralization also occurs in Precambrian granites in Labrador, but these deposits presently lie within Inuit lands that are... 

S.5.5.2.3 Historical controls Since many clinical trials are conducted in the same diseases, with the same control treatments there is an obvious desire to make the most use of this potentially valuable information. Can we compare the results of a new treatment in a group of patients with a group of control patients extracted from a historical database For example, suppose we are testing a new treatment for migraine headache and 60% of patients improve in the first 2 h post-treatment, compared to 30% in a group of historical control patients treated who had been treated with the current gold standard. Are we able to conclude that the new treatment is preferable to the gold standard ... 

It is critical that the examiner is familiar with the normal appearance of skeletal structures including the variants which are typical for the strain or breed of animals that is being used. Therefore, a good historical database of spontaneous abnormalities which occur in the strain of animals used is essential for a proper assessment of skeletal abnormalities observed in a prenatal developmental toxicity study. 

Small-molecule pharmaceuticals typically require two species for general toxicology evaluation that have large historical databases within a CRO and/or the public literature. In contrast, biologies should be evaluated in at least one, preferably two, species in which the test article is biologically active, namely a receptor or other entity that specifically recognizes the test article and elicits a specific pharmacological response. 

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