Computer Tape Research Articles

Frequency content of EEG and EMG at seizure onset: Possibility of removal of EMG artefact by digital filtering

EEG recordings of epileptic seizures from scalp and sphenoidal electrodes are frequently obscured by EMG activity from contracting scalp muscles. We have examined the possibility of selectively filtering the EMG artefact in order to make apparent the activity of cerebral origin. It has been shown that, during voluntary contractions of scalp muscles, most of the energy of EMG activity is above 15–20 Hz. We have shown, in recordings from 50 patients, that rhythmic activity at the onset of seizures uncontaminated by artefact had almost always a fundamental frequency lower than 25 Hz. From these two observations, we concluded that total elimination of activity above 25 Hz would eliminate most of the EMG activity, with a minimal risk of eliminating rhythmic cerebral activity. Thirty-one seizures contaminated by EMG activity were analyzed. Spectral analysis was used to assess the presence or absence of rhythmic activity at seizure onset, in the presence of obscuring EMG artefact. The spatial and temporal distribution of such a rhythmic activity was then revealed by a sharp digital filter which did not introduce phase distortions. Seizures recorded on computer tape were played back on paper following the filtering. In 16 of the 31 cases it was possible to clarify the originally obscured recordings. In 7 cases, it was found that no rhythmic cerebral activity was hidden by the EMG, a finding which was also important. In the last 8 cases, it was not possible to determine with certainty the origin, cerebral of muscular, of fast rhythmic activity present at seizure onset.

Japanese Borrowings in English

BORROWING HAS recently been declining as a major source of new English words (Cannon 1978, Cannon and Egle 1979). For example, borrowing accounts for only 252 items, or about 6 percent, of the 3988 new words recorded as main entries in Merriam-Webster's 6,000 Words. Even after we add the borrowings recorded in The Barnhart Dictionary of New English since 1963, the total is only 477 different loanwords. Of these, the major sources are French (140 words), Latin (39), Japanese (37), Italian (33), Spanish (30), German (24), and Greek (24). The predominance of Indo-European sources is hardly surprising. Mary S. Serjeantson (1935, pp. vii, 183) listed Latin, French, Scandinavian, and Italian as the most important sources. She credited Arabic as having given English the largest number of non-Indo-European loanwords, sometimes by way of another language, but noted that the number of Arabic items had declined in recent centuries (pp. 213-20). By contrast with her 192 items from Arabic, she listed only 20 borrowings from Japanese, principally beginning in the nineteenth century (pp. 239-40). Serjeantson's important book on loanwords in English, upon which histories of English have naturally drawn, is in great need of updating. Indeed, the surprising number of 33 Japanese items tabulated by Cannon and Egle (1979), in contrast with 9 items from Scandinavian and 8 from Arabic, suggests the need for a search of dictionaries to ascertain how the Japanese cultural and economic ascendancy on the world scene since World War II has affected the English vocabulary. Unfortunately, the search cannot be exhaustive without a meticulous checking of tens of thousands of pages.I The dictionaries are not on computer tape, so we cannot mechanically retrieve the items derived from Japanese or any other language. A rigorous manual search, however, discovered 587 main entries of Japanese provenience and another 216 items derived from the old borrowingJapan, which was originally a Chinese word. These Japanese loanwords make a chronological linguistic analysis feasible. The base source of Webster's Third provided 528 items, the largest number. The OED and OED Supplement (1933, 1972, 1976) dated many of the loanwords, while adding 134 dated items not also in Barnhart or 6,000 Words. The latter two dictionaries contributed 50 different loans.2 Burchfield and Smith (1973-74) added another 16.

Computerisation of diabetic clinic records.

A simple system for putting diabetic records on a computer file is achieved by using stationery that combines the usual handwritten records (not computerised) with the minimum of essential data suitable for punching on to computer tape. The record may be brought up to date at a selected time time interval. This simple, cheap system has been in use in a busy clinic for six years. The information on about 8000 diabetics now held in the computer file is used chiefly to help research by creating registers of patients with specified characteristics, such as treatment, heredity complications, and pregnancy. A complete up-to-date index of the entire clinic population is always available, and routine clinic statistics are returned every six months.

Alteration mapping with airborne multispectral scanners

An airborne multispectral scanner was flown over the Gold Acres mining district, Nevada, as part of a joint NASA-Jet Propulsion Laboratory (JPL) program to determine the proper spectral bands for detecting hydrothermal alteration zones associated with mineral deposits. The Superior Oil Company acquired the computer tapes of this mission to analyze the flight data independently. A spectral ratio technique was used to enhance the information available in different spectral bands. Selection of the ratios was based on published laboratory reflectance spectra of several appropriate alteration minerals and vegetation. Several areas were chosen for field checking based on previous geologic mapping in the area. Laboratory spectrometry of field samples indicated the multispectral scanner was not calibrated on this flight and so the bands were normalized prior to determining the ratios. A color ratio composite image was created and, upon interpretation of the ratio image in conjunction with analyses of field samples, it is concluded that this technique is useful for discriminating a suite of alteration minerals which include clay minerals, iron oxides, and combinations of these. Areas of hydrothermal and supergene alteration, such as those that occur at the Gold Acres and Tenabo districts, are characterized by a combination of clays and iron oxides. Both of these districts, and altered extensions of the districts, are recognizable on the ratio image because of the enhanced discrimination of clays and iron oxides.

New Products

Essentially a manual-load version of the SLT-80, the Dennison Kybe MLT-500 cleaner/tester for maintaining and evaluating 800-, 1600-, and 6250-bpi computer tapes differentiates between signal dropouts that are within a system's error correction routines and those that will cause an abort, a testing technique that emulates the tape transport's 1600-bpi error recognition routines.

Fatal myocardial infarction and the role of oral contraceptives.

The association between use of oral contraceptives (OC) and death from myocardial infarction (MI) in young women was investigated in a collaborative case-control study conducted in the five largest metropolitan areas in the US. Potential cases were identified from computer tapes of the National Center for Health Statistics. Controls were selected from among women who died from, or were hospitalized for, acute conditions other than heart disease or from accidents, and were matched to cases on age, geographic area, and year of death. Information on cause of death, personal characteristics, OC use, and the presence of conditions predisposing to MI was obtained from interviews with relatives and abstracts of hospital, clinic and physician records. Odds ratios as approximations to relative risks for fatal MI in relation to OC use, and the associated 95% confidence limits, were calculated overall and for subgroups determined by demographic and health history characteristics. Odds ratios in the total study population were not significantly different from one. However, odds ratios significantly different from one were found when attention was restricted to white subjects without contraindications to OC use, andincluding only those cases whose deaths were attributed to MI with the greatest degree of certainty. Smoking was found to be a significant risk factor for fatal MI.

Remote sensing of snow albedo for determination of dustfall

Changes in snow reflectivity as a function of dustfall were used to measure dust deposition rates in terms of satellite reflectivity data. The results show that for dry snow conditions, snow reflectivity can be approximated by Kubelka-Munk theory. Dustfall above threshold values of 10 microg/cm(2) can be detected using Landsat computer tape data. Determination of dust deposition over ice-covered lakes and harbors appears in good agreement with sampling measurements.

Computerised processing and presentation of borehole data

The installation of a computer in logging truck for the recording analysis and presentation of borehole data offers many advantages over analog recording. Digital acquisition on to standard computer tape improves data banking and storage, facilitates interpretation with other borehole information and provides a ready format for any further processing requirement.

NORMAL PATTERNS OF FETAL ACTIVITY IN THE THIRD TRIMESTER

The incidence and frequency of fetal respiratory movements (FRM) and fetal trunk movements (FTM) were measured in 21 normal pregnancies between 28 and 39 weeks gestation. Fetal activity was assessed with a real-time ultrasound scanner and all observed movements were punched directly onto computer tape. Recordings were made for one hour in three over a 24 hour period, providing a total of 168 hours for analysis. The overall mean percentage incidence of FRM was 31 per cent at a mean breathing rate of 43 breaths/minute. The mean percentage incidence of FRM during the day (0800-1759 hours) was 37 per cent. The overall mean percentage incidence of FTM was 18 per cent with a mean of 29 moves per 30 minute observation period. The mean percentage incidence of FTM during the day (0800-1759 hours) was 16 per cent. There was a well-defined circadian variation in fetal activity with FRM peaking between 1900 and 2200 hours, and FTM between 2200 and 0100 hours. There was considerable variation in the amount of FRM and FTM recorded from hour to hour. Total fetal activity rarely fell below 10 per cent in any one recording period and this measurement may be a more useful clinical test of fetal well-being than FRM or FTM alone.

Appraising Machine-Readable Records

MACHINE-READABLE RECORDS ARE DEFINED as records created for by a computer. While this definition encompasses a wide variety of storage media including punched cards, magnetic discs, cassettes, and paper tape, the vast majority of machine-readable records are stored on magnetic computer tape. It is reasonable to anticipate that, over the next decade, on-line storage and retrieval devices with random access capability will replace magnetic tape as the primary storage medium. This suggests the possibility that new computer storage technology will radically alter the appraisal of machine-readable records. Current appraisal practices of machine-readable records differ in significant ways from those for textual records; and as computer technology progresses these differences will become even more pronounced. Indeed, it is likely that current practices and standards will be obsolete and irrelevant within a decade. It is quite costly to accession and preserve properly a single reel of computer tape. The proliferation of on-line data base management systems will make this process even more expensive, and costs will receive even greater consideration in appraisal decisions. As a result, the consequences of the rationalization (in the British sense) of the records retention process will become more evident, to the discomfort of archivists and researchers. These possibilities suggest or imply a number of points that merit consideration. The standards and practices now employed in the Machine-Readable Archives Division of the National Archives and Records Service, with attention to the changes likely to occur within the next decade, provide the context for this consideration. Since 1969 the staff of the National Archives has appraised machine-readable records and thereby contributed to the refinement of certain concepts and criteria that comprise the present of the art, as it were. A delineation of the sequence of decisions involved in the appraisal of machine-readable records can convey the current state of the art. The first decision—whether a file will be appraised—is left largely to agency records officers. A disposition schedule for machine-readable records identifies categories of disposable and non-disposable computer tape The former, consisting of files that range from initial data input to update transactions, are automatically disposable without regard to subject matter. In most federal agencies at least 60 percent of computer tape files are disposable as processing files. Most non-disposable files, which must be offered to the National

Computer Controlled Oral Test Administration: a Method and Example

A computer tape recorder interface was designed, which permits automatic oral administration of "true-false" or "multiple-choice" type tests. This paper describes the hardware and control program software which were developed to implement the method on a DEC PDP 11 computer. The method is illustrated by an extended example that describes automatic oral administration of the Minnesota M ultiphasic Personality Inventory (MMPI). Similar concepts may be applied to implement the idea for other computer systems or other tests. The principal advantage of this method is that it does not require an expensive computer terminal. Auxiliary programs may be used for subsequent batch mode test scoring and analysis.

Barkhausen effect in magnetic thin films: General behaviour and stationarity along the hysteresis loop

Several aspects of the Barkhausen effect can be investigated by using a measurement equipment that records the Barkhausen signal as a function of time in digital form on computer tape. Measurements on thin magnetic films containing a small number of domain walls are presented. The behaviour of the wall jumps during a reversal is investigated. During the steep part of the loop the stationarity of the signal is measured with the magnetic field as a parameter. The influence of the coercive fieldH c and the thicknessd m is considered and compared with results obtained by others on bulk samples.

Current practices and future trends in the processing of airplane flyover noise data

Airplane flyover noise testing techniques have grown in complexity and sophistication during the past several years. This growth has resulted in substantial increases in the variety and quantity of data acquired in support of flyover noise test programs. In addition to the basic measured noise levels, large amounts of data describing airplane/engine performance, space position, and sound-path meteorological conditions are also acquired. Data processing procedures and techniques were developed to efficiently integrate these large quantities of flight test data onto a single computer tape, which can be easily used for analytical studies. The methods have been optimized to provide visibility of data validity, and to provide sufficient flexibility to accommodate the unique data requirements of each test program. The data processing cycle has been highly automated using both small- and large-scale digital computers. Near-term advances in data processing techniques discussed include (1) increased use of statistical analysis techniques using integrated subroutines, (2) advanced narrow-band spectrum analysis techniques for improved noise source description, and (3) increased use of automated error detection and correction techniques.

Preliminary Geostatistical Investigations Of Tar-Bearing Sands, Lease-13, Athabasca Tar Sands

Abstract Preliminary geostatistical studies of the tar sand measures in the Lower Cretaceous McMurray formation have shown that variograms of net thickness and grade of tar sand are well formed. These show that the variogram ranges (radii of influence) of net thickness and grade are 4,000-5,000 feet, much wider than the sampling density. Fines, the clay and silt fraction within the orebody, were studied in conjunction with tar grade for one of the orebodies. The best estimation of fines was found to be from a combined, correlation of tar grade and natural radioactivity (gamma-ray emission). The variogram of fines in this orebody indicated that fines are randomly distributed. It was concluded that the sampling done on Lease-1S was sufficient for locating all major orebodies and for estimating the tar reservoirs accurately. The sampling was also sufficient for initial mine planning. One use of the geostatistical data, to estimate the 'Variance of tar grade and fines in the mill feed based on one mining method, is described. Introduction THE ATHABASCA TAR SANDS of Western Canada represent a large potential reserve of liquid hydrocarbon which is only now being developed. One commercial mine is in operation and a second is under construction. Tar, or bitumen, the objective mineral, is a black hydrocarbon so viscous that it Is immobile at normal in-situ rock temperatures. The tar occurs as pore filling in the sand portion of a sand shale series of Cretaceous age. The depositional environment of the formation is deltaic to near-shore where it lies close enough to the surface to be mined. In these areas, the tar sands are overlain mainly by a thin mantle of Pliestocene glacial till and underlain by Devonian carbonates. The material for this study comes from Shell Canada's Lease-13, located about 50 miles north of the town of Fort McMurray. Lease-13 is a block roughly 6 by 13 miles. One-Dimensional Variograms We decided to undertake statistical studies of the sands to give us a better predictive tool for ore reserves and for use in mine planning. At the time, we had information from 350 sample holes in which a foot-by-foot analysis of 40,000 feet had been made. In the analysis, overburden and other rejects had been identified, and a base to the ore picked. Further, within the ore, ore grade and fines had been determined. This material was available on a computer tape data file. The sampling pattern for the 350 holes is shown on Figure l. Our first approach, to see whether geostatistics would be useful, was to make a simple one-dimensional non-directional test of values. For this test, we determined for each hole a single value for each of the parameters we were to study - tar sand net pay, tar grade thickness, overburden thickness, total reject thickness and quality factor. Quality factor is an economic parameter relating overburden thickness, ore thickness and ore grade. The variograms for this study were developed using the onewdimensional form of Matheron's (1,2) formula, as follows:

The Pacific basin in world trade an analysis of changing trade patterns, 1955–1975

This is the third of a sequence of papers on international flows of trade among fifteen Pacific Basin (PB) countries and between them and eleven regions in the Rest of the World (ROW). In Part I of the sequence (Hickman, Kuroda and Lau, 1977a) we presented and documented annual data on bilateral flows of total exports valued f.o.b. in current dollars among the twenty-six countries and regions for the years 1948 through1975. The primary data source is the Direction of Trade computer tape of the International Monetary Fund, but these data were supplemented from other sources, especially as regards the international trade of the socialist countries. The second report (1977b) extended the data base to include unit value export price indexes and the corresponding constant dollar trade flow matrices for the period 1955-1975. In this third report we analyze the changing pattern of PB trade over the same period, using as tools export growth decomposition indexes, trend analysis, and regression analysis of the price elasticity of import market shares. The present paper is organized as follows. In Section 2 we describe the trends in the export performance of the PB countries and ROW regions, as measured by the cumulative percentage change in each country's share of world exports between 1955 and 1975 and for selected sub periods. In Section 3 and Appendices B and C these export share changes are decomposed into three sources: changes in the degree of penetration of the various import markets, changes in the size of the import markets themselves, and an interaction effect. The decomposition indexes are shown in Section 4 to be dominated by the market penetration or competitiveness effect, so that a country gains or loses in world trade according to whether or not it can increase its shares of the markets in which it sells rather than as a passive result of changes in the size of the markets themselves. This leads to a descriptive analysis in Section 5 of the secular growth rates of the market shares of each country or region in the import markets of the twenty-five remaining countries and regions. Finally, we conclude the paper in Section 6 with art exploratory regression analysis of the responsiveness of the market shares to changes in the relative prices of the various exporting countries competing in each import market, leading to the general conclusion that relative prices do matter and presenting estimates of share or substitution elasticities in the various import markets.

The Agenda for “Social Science History”

I want to take as my texts today statements made to me in correspondence and conversation by two senior quantitative historians. Each statement illustrates what I believe to be misjudgments about the proper methodological priorities for quantitative historians in America today. To spare these historians from publicity which their casual statements were not intended to invite, but mostly to protect myself against reprisal, I shall not name them here.The first statement arose because I assigned a particular book in my American Political History course. Some of my colleagues, students, and I were critical of the methodology employed in the book, and a student suggested we might reanalyze the data, employing different techniques. The data set, however, was rather obscure and was apparently not available at any major archive. When I wrote to the author, rather brashly asking for a copy of his computer tapes, I was informed that he had “lost interest” in the project after the first year or so and discarded most of the tapes and IBM cards.

On noise in digital recording

A set of rules, equations and relations are given for the effects of coherent and statistical noise on digital recorders. Simple formulas, intended for laboratory use, are given for the change in signal to noise ratio (SNR) caused by the channel. Bit error probability is related to SNR and channel parameters for the zero-crossing detector channels typical of digital computer disk and tape recorders, and many digital instrumentation recorders. Valid and invalid ways to calculate error rate statistics are discussed for situations where bit errors are correlated, i.e. not statistically independent.

Survey Data about Religion Available from Data Banks

T he organization of data banks which make available data from surveys has facilitated secondary analysis of sample survey data (Hyman, 1972). As part of a project about measurement in social science studies of religion, I wrote to all the major organizations which maintain files of survey data. Each of these data banks was asked for a list of studies in its collection about religion. Hundreds of studies deposited in the data banks contain one or two variables concerning religion. Religious affiliation and church attendance are very common. Carroll and Roozen (1973) have described the availability of individual questions on religion in the collection of one of the data banks-the Roper Public Opinion Research Center. Their report has been updated by Voss (1974). I only found twenty studies on file at the data banks which contain several variables concerning religion. A list of these studies is presented below. This list is intended to show researchers what is available in order that more use can be made of the data. A study available from more than one data bank is so indicated; costs will vary from one source to another. The format in which these studies are available varies. Studies may be available only on computer tape, or only on IBM cards, or either way. Some data sets have been cleaned and others remain slovenly. The quality of codebook documentation is uneven. Special permission is required to use some of the studies. Detailed information, including costs, is available directly from the data banks.

THE USE OF SURGERY TO AVOID CHILDBEARING AMONG NAVAJO AND HOPI INDIANS

The Hopi Indians neighbors of the Navajos in Northern Arizona have reduced their fertility much more rapidly than the Navajos. Data accumulated from computer tapes of discharges from the Indian Health Service during 1972-1973 and data published by the Commission on Professional and Hospital Activities for 1971 were the basis of this report. The Hopis and the Navajos have the same rate of uncomplicated deliveries. Both groups have a low rate of abortion. However the age-specific pattern of abortions is distinctly different. The abortion rate in the Hopis rises dramatically in the age group over 40. In determining the number of hysterectomies Hopis clearly have a higher rate. However hysterectomies for sterilizations are difficult to separate from those for other causes. The rate of bilateral tubal ligations among the Hopis occurs during their fertile years. Differences between the tribes above the age of 35 are less apparent. Hopi women are determined to terminate childbearing when they reach their late 30s and early 40s and are still having children. Vasectomies among both tribes are rare. Because data on other methods of contraception are unavailable it is difficult to make a definitive answer as to whether the increased frequency of surgery among the Hopis is the result of failure with more conventional contraceptive methods. Other variables may also affect the results (education physician characteristics and hospital accessibility).

Spectrum atlas nears completion

Much research in geophysics, aeronomy, planetary and cometary physics; and astrophysics requires the knowledge of the spectrum of the light of the integrated solar disk with high spectral resolution and high photometric accuracy. An atlas of the spectrum of this solar irradiance will soon be available from the Sacramento Peak Observatory, AFGL, Sunspot, New Mexico 88349. The atlas will cover the wavelength region from 380 to 700 nm with a spectral resolution of 4×105 . It will be available in tabular and graphical form as an Air Force Geophysics Laboratories in‐house publication and on computer tape (7 or 9 track).