Showing papers on "Data acquisition published in 1975"

Measurement and analysis of engine pressure data

Abstract: This paper provides a user oriented description of techniques for the measurement and analysis of engine cylinder pressures. These techniques were developed for piexoelectric transducers and for digital systems of data acquisition and analysis. Test cell procedures are described for transducer preparation and calibration, and for association of each pressure with its appropriate crank angle. Techniques are also described for evaluating the accuracy of pressure data and for eliminating specific errors. Two examples of uses for pressure data are discussed: the calculation of heat release rate in conventional engines, and the computation of internal flows in divided chamber engines. /GMRL/

Three-dimensional rectilinear scanner

Abstract: A rectilinear scanner for detecting radiation in a plurality of channels utilizing a collimator. Each of the channels receives information from a different portion of the collimator. Information separately received is separately massaged and later collated to present a common image. The information is processed by apparatus in a data processing system. This system has means for massaging analog signals corresponding to gamma radiation counts. This system has means for converting such analog signals to digital signals. This system has means interfacing the digital signals into an address register that communicates directly via data busses to core memory of a central processing unit by cycle stealing. This system has means deriving clinically significant information by computation on the resultant digital data. This system has means storing, retrieving, and displaying the resultant digital data and the resultant derivations therefrom collectively. This is done in such a manner as to allow time sequencing of the aforementioned operations such that the aforementioned operations can be interleaved on a real time basis.

Data acquisition and analysis

Abstract: o Solartron Model Chas 08, modulab 8 slot chassis, Model FRA 1MHz (frequency range 10 μHz to 1MHz, swept sine, multi-sine/FFT, harmonic analysis. Model Pstat 1 MS/s Potentiostat/Galvanostat maximum data acquisition rate. Includes Modulab 2A Internal Booster option o Solartron Model 1260 Impedance Analyzer o Solartron/Analyzer Model 1260 Impedance Analyzer with Model 1287 electrochemical interface, used to measure ionic/electronic conductivity, electrochemical impedance spectra o Solartron 1284 Potentiostat Single channel o Princeton Applied Research Advanced Measurement Model VMP2/Z-40 4 channel multipotentiostat with impedance; Model VMPB2-25 2 x 5A power booster for VMP2; Model VMPB2-10 10A additional booster channel for VMP24 independent potentiostat/impedance channels that allow for testing and monitoring up to 4 single cells in parallel greatly increasing throughput on long term durability tests. o RDP Howden Ltd Model ME46-350NG High resolution video extensometer with automatic target recognition and operating software o Varian Inc. Micro GC Dual Channel System including software CP-4900 Provides precise gas analysis in seconds, one to four plug-and play-GC channels Each channel is a separate GC with pneumatics injector, column, and detector; the micro-electronic gas control with time programmable backflush allows injection of samples while eliminating contamination o National Instruments Model PXI-6508 Digital I/O and DAQ system with Lab View o National Instruments Model SCXI-1000 chassis-allows for the monitoring of 32 + temperature channels, along with digital and analog channels. System allows for efficient output control based on the inputs.

A spectrum analysis of acoustic emission

Abstract: The authors describe a data acquisition system to determine the frequency spectrum between 500 KHz and 3 MHz of the initial acoustic emission. They measured the transfer function of the piezoelectric transducer and of the specimen for their results using a computer. They present an application of this device to the study of the emission of a low-carbon steel.

Synthesizer for testing elements of a geophysical data acquisition system

Abstract: This disclosure relates to a non-recursive digital synthesizer for producing a surprisingly accurate synthesized sinusoid suitable for testing elements of a geophysical data acquisition system in either a laboratory or a field environment. In accordance with the present invention, [(C/2)+1]-discrete--16-bit binary words are stored in a read-only memory (ROM), representing discrete amplitudes of a digitized sinusoid in a frequency range of 1-500 Hz, and then accessed in succession to a digital-to-analog converter (DAC). A separate suppression circuit means at the output of the DAC is adapted to operate in synchronization with movement of the binary words through the DAC; in that way, glitches generated by the various digital elements of the synthesizer are suppressed. Result: accuracy of the generated sinusoid to the elements under test is assured.

Baseline Modeling with a Computerized Raman System

Abstract: A PDP-11-to-Raman spectrometer interface for data acquisition and plotting is described. The background correction problem, which occurs in the transition from data acquisition to the data analysis of chemical interest, has been studied for the nontrivial case of considerable curvature near the Rayleigh wing. The conflict between a baseline function with sufficient freedom to compensate properly for the background and sufficient constraint to achieve uniqueness and reproducibility has been demonstrated. A comparative study has shown the superiority of an exponential-quadratic baseline function over common interpolation procedures such as the cubic spline, the fitting of simple shape-functions to the background, or polynomial expansions.

Thaumascan: Design Considerations and Performance Characteristics

Abstract: Thaumascan is an acronym for a two-dimensional, high resolution, actual time, ultrasound, multi-element, array scanner. This system substantially reduces or overcomes such limitations as low data acquisition rates, low lateral resolution and problems associated with the large dynamic range of echo information typical of most currently available imaging systems.

Multivariate statistical pattern recognition system for reactor noise analysis

Abstract: A multivariate statistical pattern recognition system for reactor noise analysis was developed. The basis of the system is a transformation for decoupling correlated variables and algorithms for inferring probability density functions. The system is adaptable to a variety of statistical properties of the data, and it has learning, tracking, and updating capabilities. System design emphasizes control of the false-alarm rate. The ability of the system to learn normal patterns of reactor behavior and to recognize deviations from these patterns was evaluated by experiments at the ORNL High-Flux Isotope Reactor (HFIR). Power perturbations of less than 0.1 percent of the mean value in selected frequency ranges were detected by the system. 19 references. (auth)

Real-Time Central Data Acquisition and Analysis System for High-Voltage Transients

Abstract: A system has been developed for ultra-high-speed digital recording and analysis of transient phenomena. It enables one to look back in time, recording signals that occur prior to single events which have statistical uncertainties of occurrence, such as lightning or breakdown phenomena. The system as installed is playing an essential role in studying " cause-effect" relationships through the acquisition and analysis of data. Data are received in an asynchronous fashion in real time and stored in a cartridge disk through Transient Recorders (Biomation Model 8100) and minicomputer (Melcom-70, Japan). The system is time-shared and digital-controlled by multiple users from remote consoles located at nine test stations. The stored data are retrieved and analyzed with highest "time availability" priority to get processed information through correlation, statistical analysis or various computer-aided simulations. Special precautions have been taken against high energy electromagnetic noise fields, such as grounding, shielding, etc., in order to attain noise-proof operation. Principles of operation, major components, and examples of the application of the system are presented.

Quantification of ventricular performance: a computer-based system for the analysis of angiographic data

Abstract: A computer-based quantitative angiography system for the acquisition and analysis of ventriculographic data has been developed. In addition to the apparatus normally required for angiography and left ventricular pressure recording, a digitizing tablet, PDP 11/20 mini computer, and TV monitor with a hard-copy device is employed. Four modes of operation are currently in use: data acquisition, analysis, mini cine, and data tape editor. Data acquisition facilitates forming a magnetic tape record of the digitized pressure, timing, and event identification, together with anywhere from 4 to 100 digitilized LV contours. A number of error checks and feedbacks are incorporated to provide some measure of quality control. In the event an error is written onto the magnetic tape record, the data tape editor can be used to review the record and correct most errors. Analysis of the generated data tape consists of several options which include: pump function, muscle function, pressure derived indices of contractility and systolic time intervals, and contour pattern recognition which is still under development. If the complete analysis option is chosen, a summary of the analysis, referred to as the quick-sight list, is also presented. The so called mini cine option employs a separate and independent acquisition-analysis program. This requires only the end-diastolic (with a segment of wall) and end-systolic contours (without pressure data) to extract the most essential parameters (EDV, EF, CI, HR, and wall mass). As a result of the relative straightforward processing and inherent simplicity, the mini cine option is most frequently used. This system has done much to reduce the time required for analysis of angiographic data, while at the same time maintaining and even improving the quality of the results. Other less tangible benefits include: the possibility to build a readily accessible library of patient data files facilitating a posteriori studies, precise and uniform definition of the rules to input and analyze data, and finally providing a useful step towards fully automatic ventriculographic processing.

A new lidar signal processor using digital techniques to provide real-time display

Abstract: An accurate high speed digital data acquisition system which records lidar data on magnetic tape is discussed. It features real-time processing of the data by means of a low cost dedicated processor. The system features dual-channel recording capability, and has two built-in gain-switching amplifiers, allowing the system to accurately record the entire return signal having a dynamic range in excess of 80 dB. Dual differential inputs are used to provide excellent noise immunity.

A random search algorithm for laboratory computers

Abstract: The small laboratory computer is ideal for experimental control and data acquisition. Postexperimental data processing is often performed on large computers because of the availability of sophisticated programs, but costs and data compatibility are negative factors. Parameter optimization can be accomplished on the small computer, offering ease of programming, data compatibility, and low cost. A previously proposed random-search algorithm ('random creep') was found to be very slow in convergence. A method is proposed (the 'random leap' algorithm) which starts in a global search mode and automatically adjusts step size to speed convergence. A FORTRAN executive program for the random-leap algorithm is presented which calls a user-supplied function subroutine. An example of a function subroutine is given which calculates maximum-likelihood estimates of receiver operating-characteristic parameters from binary response data. Other applications in parameter estimation, generalized least squares, and matrix inversion are discussed.

A minicomputer-controlled all-digital tensile test system

Abstract: This paper presents the design, construction, and evaluation of an all-digital programmable tensile test system, superior in several ways to other systems presently available for testing yarns. However, the basic system concepts can be applied to tensile test systems for other materials. The system is capable of performing three standard yarn tests: constant rate of extension, constant rate of loading, and fatigue. Extension rates range from 1 mm/s to 420 mm/s. Loading rates of up to 700 g/s and above are possible. Fatigue testing allows sinusoidal loading of yarn at frequencies from 0.88 to 5.2 Hz. A minicomputer is used for direct digital control, data acquisition, and on-line analysis. A digital tension mechanism incorporating a variable-reluctance step motor was designed and constructed. A "fractional stepping" scheme is presented where the computer software is used to improve the displacement resolution for slow-speed breaks. A unique indirect digital force transducer was designed for the system employing transistor-transistor logic integrated circuits. The interrogation rate is 7 kHz, the load range is 0-700 g, and resolution for the present design is 4 g. Final testing of the digital system involves the comparison of test results with those from a proved programmable analog tester. The three types of tests produced good results and show that the digital test system does characterize yarn break strength for different types of yarn. It overcomes many disadvantages of analog systems and performs certain tasks which these systems are unable to perform.

An acquisition and analysis system for on-line experiments on the neurophysiology of learning

Abstract: An integrated hardware and software system is used in studying neural correlates of learning. The hardware system is designed to maximize experimental flexibility, while the software system is designed to maximize computer speed for data acquisition and programmer efficiency for data analysis.

A data acquisition system for unobtrusive measurement of on-road driving behavior

Abstract: Unobtrusive measurement of on-road driving utilizing permanently installed pavement sensors and movable photographic devices requires expensive installation and/or time consuming data reduction. This paper describes a mobile system for remotely measuring driving performance on public highways and recording the data in computer compatible format. Speed and lateral movements of cars are sensed via a radar antenna and video camera, electronically processed, and stored on magnetic tape. The taped records can be automatically read and compiled by computer.

Real-time detection and data acquisition system for the left ventricular outline

Abstract: To automate the data acquisition procedure, a real-time contour detection and data acquisition system for the left ventricular outline was developed using video techniques. The X-ray image of the contrast-filled left ventricle is stored for subsequent processing on film (cineangiogram), video tape or disc. The cineangiogram is converted into video format using a television camera. The video signal from either the TV camera, video tape or disc is the input signal to the system. The contour detection is based on a dynamic thresholding technique. Since the left ventricular outline is a smooth continuous function, for each contour side a narrow expectation window is defined in which the next borderpoint will be detected. A computer interface was designed and built for the online acquisition of the coordinates using a PDP-12 computer. The advantage of this system over other available systems is its potential for online, real-time acquisition of the left ventricular size and shape during angiocardiography.

An automated activation analysis data acquisition system

Abstract: An automated neutron activation analysis data acquisition system has been assembled from commercially available equipment. The modifications of the components needed to make this into a working system are described in the text. The main components of the data acquisition system are a sample changer, a Ge(Li) detector, a magnetic tape deck and a minicomputer based multichannel analyzer. The sample changer has a 200-sample capacity and can handle both solid and liquid samples. Software for controlling the data acquisition system is flexible, yet simple to use. The system has operated reliably for a year and has sharply reduced the effort needed for data acquisition.

A note on cost-effectiveness in data acquisition in water quality management

Abstract: An iterative procedure for sampling in water quality management is presented. The procedure establishes a relationship between cost of sampling and relative uncertainty in total discharge into the water system and at the same time provides an optimal frequency matrix for sampling. The frequency of sampling at each discharge is treated as an independent variable.

Mariner 10 mission analysis - Application of a black art. [trajectory selection for data acquisition optimization

Abstract: A major accomplishment of the mission analysis performed for Mariner 10 was the selection of a trajectory which optimized science return from the mission. The analysis utilized simple, unweighted 'science value functions' which allowed the relative values of each candidate trajectory, for each of the seven science experiments, to be calculated. A total relative value for each trajectory was determined by a simple averaging process and sensitivities were revealed by multiplying individual values. This showed a clear scientific preference for launching in early November and was used to support deferral of the launch from early October to November 3, 1973.

Data acquisition system for studies of driver performance in real traffic

Abstract: This paper describes a real-time data acquisition system installed in a full-sized North American automobile for the study of driver performance in real traffic and under various conditions of driver stress. The basic parameters recorded are distance traveled and three primary control movements: steering wheel, accelerator, and brake. Provision is also made for vehicle yaw measurement, driver's pulse rate, and perceived illumination level in night-driving tasks. Other parameters may be recorded as dictated by project requirements. Test conditions and principal findings of the various projects carried out at the National Research Council of Canada during the past 3 years are discussed. In these projects, the frequency and magnitude of steering wheel movements have formed the basis for assessment of driver performance and task difficulty. The application of power spectral analysis techniques appears most promising, and it is in this context that the advantages of a system for highly flexible, real-time data acquisition are most apparent.

Computer Interface for Data Acquisition and Control of an SMA 12/60

Abstract: We present an approach to the computer enhancement of the "SMA 12/60" (Technicon Instruments Corp.). Practical and theoretical considerations led to a plugcompatible system, which did not require changes in the hydraulics or methodology of the SMA. Results obtained from eight channels of the SMA using the system as described show that a sample analysis rate of 120 per hour is feasible. A desirable consequence of the increased analysis rate is a 60% decrease in the required sample volume. Before the system can be used in a clinical environment, further development will be necessary, including detection algorithms for hydraulic malfunction.