Showing papers on "Data acquisition published in 1986"

X-ray absorption in dispersive mode: A new spectrometer and a data acquisition system for fast kinetics

Abstract: The photodiode array provided a position sensitive detector for powerful X-ray sources. Then the development of the energy dispersive scheme for the X-ray absorption experiments became realistic. The data acquisition system and elements of optics are discussed. Experiments in transmission mode and in total reflection mode illustrate the dramatic gain in data acquisition time as well as advantages dealing with the focussing optics.

Fiber optic multiplexed data acquisition system

Abstract: An optics fiber multiplexed data acquisition system includes an analog modular for collecting data and then transmitting the data by fiber optics cable to a memory module located at a remote location. The memory module employs means for directly accessing a computer controlled bus memory storage system.

Data collection apparatus and train monitoring system

Abstract: An apparatus for monitoring the operation of a railroad train includes two on-board units which collect and utilize data for ultimate transfer to a portable unit which can be carried onto and off of the railroad train. One of these on-board units operates under microcomputer control to compute speed, acceleration/deceleration, and distance traveled data and to store such computred data for subsequent transfer to the portable unit. The other on-board unit acquires additional data under separate microcomputer control. This data acquisition retrieves either binary or analog data, or both, and stores it in the acquiring on-board unit for later transfer to a separate memory in the other on-board unit for subsequent transfer to the portable unit. Power failure detection circuits are also implemented to insure the microcomputers are initiated in respective determinate states.

Deviation measurement system

Abstract: A system is disclosed for determining the positions of a set of points on a vehicle body or frame and comparing those points to a set of reference points provided by the vehicle manufacturer or other source. The system includes a data acquisition apparatus comprised of emitters, receivers, and microprocessor control means. The emitters are mounted at various predetermined positions on the vehicle body or frame and are triggered in an optimal fashion by the microprocessors. Triggering generates a single acoustic burst signal from an emitter. An array of microphones acts as the receiver. After generation of the signal, the microprocessor initializes an external clock which measures the travel time of the signal from the emitter to the receivers. By repeating this process a number of times, data is acquired which yields the three-dimensional coordinates of a given point when processed by a microprocessor. Microprocessors further convert this data into a form that can be used by the overall system to determine the positions of all points measured on the vehicle body or frame. The data is transmitted to an operator display unit where it is plotted graphically. Reference data is inputted into the operator display unit via an optical decoder. This data and a comparison of the two sets of data is displayed. Based on the data comparison, the operator can then determine whether and to what extent repair work or further maintenance work on the automobile body, frame or wheels is necessary.

Digital Data Analysis Techniques for Extraction of Slosh Model Parameters

Abstract: Modern digital acquisition and modal analysis procedures are applied to the slosh model parameter extraction problem with considerable success. After appropriate data conditioning to remove the tank rigid and liquid rigid mass from the spectral data, the slosh peaks are "circle fit" to obtain estimates of the pendulum's masses, damping, and pivot arm locations. Circle fitting the data about the slosh peak does not require data acquisition at precisely the slosh resonance; therefore, the time for data acquisition and the probability of error in the model parameter estimates are greatly reduced. Equations of motion for the slosh pendulum model are reviewed along with the analytical procedures associated with circle fitting the data in the region of the slosh resonance. The experimental setup of a 1:4.85 scale model Centaur Booster fuel tank is described along with the data acquisition procedures used to obtain forced harmonic response slosh data. Several examples are given to demonstrate the accuracy of the circle fitting procedures for obtaining slosh model parameters by direct comparison of experimental data to model generated response data.

Data acquisition module and method

Abstract: A data acquisition apparatus includes two microcomputers interconnected by a shared dual access digital storage device. One microcomputer obtains the data related to the monitored condition, stores it in the digital storage device, and modifies a status word which is monitored by the other microcomputer. When the other microcomputer detects a change in the status word, it takes the data from the shared digital memory and moves it into its own memory for subsequent use or transfer. The data acquisition apparatus also includes, in a preferred embodiment, analog switches and a digital to analog converter by which external analog devices can be controlled to change the monitored operation.

Distributed Sensor Networks

Abstract: : This report summarizes Distributed Sensor Networks research conducted during the period 1 April through 30 September 1978. One specific model for function decomposition and distribution is presented. A top level design of a strawman DSN for detecting and tracking low flying aircraft is described. High resolution acoustic signal processing algorithms for the strawman are specified and sized. Additional features of a multisite target search algorithm are presented. A moderately detailed model for simulation of an acoustic node under various scenarios is developed. New model simulation and experimental data analysis software are described and demonstrated. Technical issues involved with and plans for a digital acoustic data acquisition system are presented.

Computergraphic modeling and analysis: A portable system for tracking arm movements in three-dimensional space

Abstract: A system is presented that allows automated, three-dimensional tracking of hand and arm movements. The system incorporates commercially available optoelectronic cameras and provides portable and affordable, yet accurate, three-dimensional monitoring of multiple joints of the hands and arms. Special-purpose hardware components were developed, as was software for data acquisition, data processing, and graphic display. The hardware and software are described, along with such necessary procedures as system calibration and transformation of coordinate system frames of reference. Testing of the system revealed highly accurate three-dimensional spatial tracking. The three-dimensional numeric and graphic analyses of movement made possible by this system allow new studies into the nature of the neural control of movement.

Instruments and methods a new instrument for determining strength profiles in snow cover

Abstract: The Digital Thermo-Resistograph is a port­ able microprocessor-based data-probe system for quick and accurate field collection of snow-cover strength. This was accomplished by constructing a probe with a load cell, a small snow platform for probe-position information, and a Z-80 microprocessor-based data acquisition system. A 64 x 240 dot matrix LCD graphic display unit is used to show immediately complete strength profiles in the field. Sufficient memory for the storage of 25 profiles is provided. Temperature and temperature-gradient collection is also planned as a part of the instrument but as yet this work has not been completed. The results of winter 1984 field tests are presented. The Digital Thermo-Resistograph proved to be fast and reliable in collecting snow-strength information. Comparisons with the ram penetrometer are shown and suggestions for future developments are discussed.

A New Instrument for Determining Strength Profiles in Snow Cover

Abstract: The Digital Thermo-Resistograph is a portable microprocessor-based data-probe system for quick and accurate field collection of snow-cover strength. This was accomplished by constructing a probe with a load cell, a small snow platform for probe-position information, and a Z-80 microprocessor-based data acquisition system. A 64 × 240 dot matrix LCD graphic display unit is used to show immediately complete strength profiles in the field. Sufficient memory for the storage of 25 profiles is provided. Temperature and temperature-gradient collection is also planned as a part of the instrument but as yet this work has not been completed. The results of winter 1984 field tests are presented. The Digital Thermo-Resistograph proved to be fast and reliable in collecting snow-strength information. Comparisons with the ram penetrometer are shown and suggestions for future developments are discussed.

A New Data Acquisition System at KEK

Abstract: A new data acquisition system for front-end electronics has been developed for high energy physics experiments. Parallel processing, modular construction, hand-shake bus operation, low cost with high reliability and advanced system design are its main features.

High speed data acquisition utilizing multiplex charge transfer devices

Abstract: A charge coupled device (CCD) analog shift register in a two-channel serial-parallel-serial (SPS) structure operating in a fast-in/slow-out (FISO) mode for high speed signal acquisition and temporary storage of a plurality of samples. The two CCD arrays are clocked simultaneously, and the input analog signal is demultiplexed to the two arrays. Additional transfer electrodes are provided at the input of one of the arrays, and the other array is provided with a sampling clock which is 180° out of phase with the sampling clock of the first array; two consecutive samples of the input signal are taken during each transfer clock cycle. All signal samples are clocked through the arrays simultaneously and appear at the output at the same time.

Fast computer-controlled deep level transient spectroscopy system for versatile applications in semiconductors

Abstract: A fast computer‐controlled and fully automated deep level transient spectroscopy (DLTS) system is described. Various DLTS techniques can be operated without changing the hardware. Simultaneous data acquisition and data processing considerably reduces the measurement time. The sensitivity of the system is increased by digital compensation of the sample capacitance and by averaging of a high number of transients. All the trap parameters are determined during one temperature scan.

Microprocessor system for control and data acquisition in a millimetre-wave spectrometer

Abstract: A description is given of a millimetre-wave spectrometer controlled by a dedicated microprocessor system This system, built around an Intel 8085A microprocessor, samples, digitises and stores the spectroscopic repetitive waveform and executes on the stored data some automatic data processing operations such as smoothing, baseline suppression and frequency calculation New results on the millimetre-wave spectrum of CO in very high vibrational states (v

FFT performance testing of data acquisition systems

Abstract: A low-cost fast Fourier transform (FFT) dynamic testing technique for data acquisition systems, comprising buffer, analog-to-digital converter (ADC), and sample/hold, is described. This provides an overall view of system performance, and also indicates the contribution to that performance of individual hybrid components in a signal processing chain of amplifier, multiplexer, sample/hole, and ADC, followed by RAM store.

Validity and reliability of biostereometric measurement of the human female breast.

Abstract: A measurement technique has been developed for application in the area of noninvasive breast cancer detection. The measurement process involves the use of closerange stereophotogrammetry as a data acquisition device necessary for determination of breast volume and volume distribution. This report details the methodology used to acquire and analyze stereopair photographs necessary to document the validity and reliability of this application. The volume of a test object was determined by both water displacement and stereophotogrammetric analysis to estimate the precision of the proposed methodology. Additionally, the reliability component of the study was documented by analyzing variability of coordinates representing a series of locations marked on the surface of an irregularly shaped object. Both tests confirm that this stereometric analysis is a reliable and valid method of measurement and may be well suited for further development in the field of breast cancer detection.

The Electronics for the Donner 600-Crystal Positron Tomograph

Abstract: The data acquisition system, designed for the Donner 600-Crystal Positron Tomograph, is described. Coincidence timing resolution of less than five nanoseconds full width at half maximum and data rates in excess of one million events per second are achieved by using high-speed emitter coupled logic circuits, first-in first-out memory to derandomize data flow, and parallel architecture to increase throughput. These data rates allow the acquisition of adequate transmission data in a reasonable amount of time. Good timing resolution minimizes accidental coincidences and permits data rates greater than 100,000 image-forming events per second for high-speed dynamic emission tomography. Additional scatter and accidental rejection are accomplished for transmission data by using an orbiting source and a look-up table for valid events. Calibration of this complex electronic system is performed automatically under computer control.

Design and Use of a Computer-Assisted Postmortem Identification System

Abstract: The organization and rationale for the design of a computer-assisted postmortem identification system are discussed along with results of the use of this system in extensive simulation trials on a database of 578 records. The selectivity of dental characteristics is so great that any individual with 4 or more characteristics (either fillings or missing teeth), can be separated from a group of 578 people for final verification of the identity match. The effects of errors in the database are discussed and the actual effects of different error rates on identification are shown. Error rates of up to 30% have only small effects on the ability of the system to pick out correct identity matches. The system is presently implemented on a portable microcomputer, a representative desktop computer, and a large minicomputer. The present efforts include statistical analysis of an enlarged database and testing of a data acquisition system to allow the building of a large identification database (25 000 records) in a quick and economical manner.

An area detector data acquisition system for protein crystallography using multiple-energy anomalous dispersion techniques

Abstract: We have developed an automated data acquisition system, incorporating a two-dimensional multiwire proportional counter mounted on a 5-circle diffractometer, to facilitate crystallographic data collection from protein crystals at multiple X-ray energies ∗ . This system is permanently installed on a tunable X-ray beamline at the Stanford Synchrotron Radiation Laboratory and is now fully operational. It is being used to investigate the utility of multiple-energy anomalous dispersion (MEAD) phasing techniques for determining macromolecular structures. These techniques provide an alternative to the multiple isomorphous replacement method for the solution of crystallographic phases, and have a number of advantages. This paper describes the data acquisition system in some detail and also outlines a number of the important considerations for the collection of good quality data at multiple X-ray energies from a synchrotron radiation source. We will discuss the methodology for multi-energy phasing and preliminary results in a later publication.

Computer system for a small analytical research laboratory

Abstract: A solution to three problems concerning computer use in our laboratory is described. The problems are: replacement of obsolete computer equipment, consolidation of data processing programs, and unification of the format of kinetic data from different sources. The solution involves use of a central super microcomputer with personal computers used primarily for data acquisition and temporary storage.

Data acquisition and recording system

Abstract: A portable, self-contained data acquisition and recording system is provided for monitoring ambulatory subjects. The system has micropower requirements and an extended recording capability between battery replacements. A prepolarized magnetic tape is employed and recording is accomplished by selectively reversing the polarization at a time when the tape is at rest. A microprocessor is provided for processing signals and for controlling circuit operation such as a tape drive incrementer. The microprocessor also controls the preprocessing and digitizing of signals for further processing by the microprocessor and enables the delivery of digital signals to be recorded to a magnetic tape head positioned in operative relationship with the magnetic tape. Selected circuits of the system are selectively powered up and powered down during monitoring as needed to provide continuous power control for optimization of power usage.

A versatile data acquisition system for low‐energy electron diffraction

Abstract: We have developed a system for rapid data acquisition from low‐energy electron diffraction (LEED) patterns. The essential components of the system are a sensitive silicon intensified target video camera, a commercial video interface, and a PDP 11/23 microcomputer. The system is designed to acquire up to ten diffraction spot intensities and profiles (total) in a short time relative to the time scales of typical surface reactions. The data acquisition system is used in conjunction with standard Varian■ four‐grid LEED optics in an ultrahigh vacuum chamber. The abilities of the system with respect to versatility, speed, linearity, and signal‐to‐noise are demonstrated, and data from a study of oxygen chemisorption on Pd(100) are presented.

A Direct MRJ Hankel Transform System Using Rotating Gradients

Abstract: A novel magnetic resonance imaging system is explored which uses data collected in the presence of quadrature phase sinusoidal gradients along an excited plane. It is shown that the resulting magnetization signal (FID) is a sum of the Hankel transforms of the radial modulators of the imaged plane. An efficient processing system is suggested which extracts the different Hankel transforms from the received signal. These transforms are used to directly reconstruct the two-dimensional (2-D) image using either 1-D inverse Hankel transforms or a 2-D inverse Fourier transform. A "snapshot" data acquisition procedure is described which enables the collection of all the required data from a signal FID. The main advantages of the proposed system are rapid acquisition time, the ability to trade-off acquisition time, and SNR and resonant gradient circuits.

An IBM PC based Mössbauer spectrometer and data analysis system

Abstract: An IBM Personal Computer based multichannel analyzer system that functions as a Mossbauer spectrometer is described. This system is derived from the addition to the IBM PC of a PCA 8000 data acquisition board modified with a small special purpose interface. The graphics capabilities of the system are demonstrated with a few representative spectra. Software written in Advanced BASIC permits evaluation of previously acquired spectra concurrently with data acquisition.