Data acquisition technique

The following techniques can be used to collect data about human performance in CPI tasks and provide input to task analysis methods described in Section 4.3. These data can include process information critical for the task, control strategies used by the workers, diagnostic plans etc. A distinction can be made among data collection methods that provide qualitative data (such as interviews, observations, and sources of documentation) and methods that can be used to measure aspects of performance (such as activity analysis, simulations, and information withholding). The latter methods can provide more precise data which can be quantified. 

Useful protocols can only be produced for information that is coded in a verbal form in memory. Tasks that rely on visual imagery for their execution, or have become automated due to over-practice wiU be very difficult to verbalize. Hence the technique may provide little useful information and may even produce misleading reports for these tasks. To encourage task verbalization some coaching should be given to the task experts and the goals of the study should be explained so that they can make greater efforts to report on aspects of the task which are of particular importance. 

One way of analyzing the data is to use a columnar format, with columns such as Displays Used, Control Used, Action, Decision, Goal Pursued, etc. which are filled in directly from the protocol information. A useful discussion of the application of the technique to process control tasks is given by Bain-bridge (1974), and Ainsworth and Whitfield (1984). Apart from collecting data about the task, discussions and interviews with the workers can get their direct commitment to a project and can make them feel that they own any proposed new work system. 

Analytical Methods for Predicting and Redudng Human Error 

Discussions and interviews with the task experts can be supplemented with observations of their actual performance, for example, taking notes on certain aspects of the task or taking video or audio recordings. Observational techniques can reveal information that may be difficult to acquire in any other way. Detailed physical task performance data can be recorded, and major environmental influences (e.g., noise, light, interruptions) can all be faithfully represented. Observations can also provide an insight into the way that the team members communicate, allocate job responsibilities, and make use of operating procedures and other resources. 

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Analyzers especially equipped to handle noise are required for most industrial applications. There are at least three commercially available microprocessor-based analyzers capable of acquiring data below 600 cpm. These systems use special filters and data-acquisition techniques to separate real vibration frequencies from electronic... 

The type of transducers and data acquisition techniques that you will use for the program is the final critical factor that can determine the success or failure of your program. Their accuracy, proper application and mounting will determine whether valid data will be collected. 

Conventional utilization of solution-phase NMR data acquisition techniques on solid samples yields broad, featureless spectra (Fig. 1A). The broad nature of the signal is due primarily to dipolar interactions, which do not average out to zero in the solid state, and chemical shift anisotropy (CSA), which again occurs because our compound of interest is in the solid state. Before one describes the two principal reasons for the broad, featureless spectra, it is important to understand the main interactions that a nucleus with a magnetic moment experiences when situated within a magnetic field in the solid state. In addition, manifestations of these interactions in the solid state NMR spectrum need to be discussed. 

While new data acquisition techniques under development may significantly reduce the time and increase the precision of recording diffraction patterns, it is obvious that X-ray diffraction techniques will be restricted to the study of conformations and intermediates which are stable for periods that exceed the normal half-life of these transient species. It is therefore necessary to increase the lifetime of such species so that their three-dimensional structures may be determined in the same manner as a native enzyme. 

The algorithm just discussed is a qualitative version of what must be done for each particle detectable above the noise level at both 6° and 12°. In reality the allowable 3° signal range depends on the observed 12°/6° ratio. Thus any data acquisition technique must be able to observe the 12°/6° ratio, to calculate a corresponding allowable 3°/6° ratio for comparison with that actually measured, and finally to decide on the validity of the particle based on this comparison. 

In cooperation with instrument designers, the group of Hass [167] showed the advantages of data acquisition techniques, especially to automate the adjustment of the main beam studied scanning of the different fields and detection of multiple metastable ions the acquisition of metastable spectra the various calculations of exact mass and energy liberated during the formation of metastable ions the different automatic processes of the reversed geometry mass spectrometer, such as ZAB 2F. 

Before data acquisition techniques for stress MS experiments are reviewed, the operation of the TOFMS is discussed briefly. Detailed discussions of the theory and principles of TOFMS operation are in the literature (19,20), The essential features of a TOFMS are shown in Figure 5. The elements A, B, C, E, and F provide a pulsed monoenergetic electron beam of fixed current which ionizes molecules in the ion-source... 

Cinematography. This data acquisition technique is straightforward in principle but tedious in practice. A high-speed movie camera photographs the mass spectral display on the oscilloscope screen. When the camera operates at 400 frames per sec and the mass spectrometer at a repetition rate of 10 kHz, each frame of the film contains the information of 25 mass spectra. This arrangement permits time resolution of 2.5 msec. A 150-m film records data for approximately 50 sec which is adequate for most stress MS experiments. 

Still Photography. The use of a still camera to record the mass spectral data displayed on the oscillographic screen is an alternate photographic data acquisition technique. The simplest method is to photograph the oscilloscope display for a fixed time during which the sample is stressed and/or fails. This technique does not permit resolution of changes in the mass spectra with time but provides a way to record qualitative information with readily available equipment. 

Continuous Monitoring. Continuous ion monitoring is a mass spectrometric data acquisition technique with a long history which was recently reviewed by Falkner (23), Byl skii (8) reports the utility of this technique for studying the kinetics of the mechanical degradation of... 

The range of experimental methods and data acquisition techniques for stress mass spectrometry experiments provide a way to obtain a great amount of data on the volatile compounds evolved from polymeric samples when subjected to a mechanical load. These data provide information concerning the events occurring in the polymer which produce the evolved volatile compounds. 

Contactless data-acquisition techniques can also be used in BIT. Such systems may involve coils for inducing currents but with usual PU electrodes. Totally, contactless circuitry is also possible with magnetic coils or capacitive coupling both for the current excitation and for measuring the tissue current response. Contactless systems have been presented at frequencies up to 20 MHz. 

Dynamic loading problems in the offshore environment depend on either estimated or measured values of shear modulus. In practice, in situ determination of shear wave velocity on land has been used as the best approximation to the actual values for laboratory tests on samples (Richart, 1975). The techniques for using these seismic methods and data acquisition techniques to determine shear wave velocity for land-based applications have been well developed. The problem in the marine environment has been to develop methods to determine in situ shear wave velocity measurements both at the seabed surface and at known depths in the sediment column, which can be determined in a cost-effective manner. 

Estermann, M.A. Steurer, W. Diffuse scattering data acquisition techniques. Phase Transit. 1998. B67, 165-195. 

Contactless data acquisition techniques are also used in BIT. Such systems may involve coils for inducing currents and electrodes for measuring voltage or they may be totally... 

The Influence of Amplifiers and Data Acquisition Techniques to Signal-based AET... 

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