926 research outputs found

    Instrument for determining coincidence and elapse time between independent sources of random sequential events

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    An instrument that receives pulses from a primary external source and one or more secondary external sources and determines when there is coincidence between the primary and one of the secondary sources is described. The instrument generates a finite time window (coincidence aperture) during which coincidence is defined to have occurred. The time intervals between coincidence apertures in which coincidences occur are measured

    The Growing Allocative Inefficiency of the U.S. Higher Education Sector

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    This paper presents new evidence on research and teaching productivity in universities using a panel of 102 top U.S. schools during 1981-1999. Faculty employment grows at 0.6 percent per year, compared with growth of 4.9 percent in industrial researchers. Productivity growth per researcher is 1.4-6.7 percent and is higher in private universities. Productivity growth per teacher is 0.8-1.1 percent and is higher in public universities. Growth in research productivity within universities exceeds overall growth, because the research share grows in universities where productivity growth is less. This finding suggests that allocative efficiency of U.S. higher education declined during the late 20th century. R&D stock, endowment, and post-docs increase research productivity in universities, the effect of nonfederal R&D is less, and the returns to research are diminishing. Since the nonfederal R&D share grows and is higher in public schools, this may explain the rising inefficiency. Decreasing returns in research but not teaching suggest that most differences in university size are due to teaching.

    The Growing Allocative Inefficiency of the U.S. Higher Education Sector

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    This paper presents new evidence on research and teaching productivity in universities. The findings are based on a panel that covers 1981-1999 and includes 102 top U.S. universities. Faculty size grows at 0.6 percent per year, compared with growth of 4.9 percent in the industrial science and engineering workforce. Measured by papers and citations per researcher, productivity grows at 1.4-6.7 percent per year and productivity and its rate of growth are higher in private than public universities. Measured by baccalaureate and graduate degrees per teacher, teaching productivity grows at 0.8-1.1 percent per year and growth is faster in public than private universities. A decomposition analysis shows that growth in research productivity within universities exceeds overall growth. This is because research shares grow more rapidly in universities whose productivity grows less rapidly. Likewise the research share of public universities increases even though productivity grows less rapidly in public universities. Together these findings suggest that allocative efficiency of U.S. higher education declined during the late 20th century. Regression analysis of individual universities finds that R&D stock, endowment, and postdoctoral students increase research productivity, that the effect of nonfederal R&D stock is less, and that research is subject to decreasing returns. Since the nonfederal R&D share grows and is much higher in public universities, this could account for some of the rising allocative inefficiency. The evidence for decreasing returns in research, which are greater than in teaching, suggests limits on the ability of more efficient institutions to expand and implies that differences in the scale of the teaching function are the primary reason for differences in university size. Besides all this the data strongly hint at growing financial pressures on U.S. public universities.

    Science and Industry: Tracing the Flow of Basic Research through Manufacturing and Trade

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    This paper describes flows of basic research through the U.S. economy and explores their implications for scientific output at the industry and field level. The time period is the late 20th century. This paper differs from others in its use of measures of science rather than technology. Together its results provide a more complete picture of the structure of basic research flows than was previously available. Basic research flows are high within petrochemicals and drugs and within a second cluster composed of software and communications. Flows of chemistry, physics, and engineering are common throughout industry; biology and medicine are almost confined to petrochemicals and drugs, and computer science is nearly as limited to software and communications. In general, basic research flows are more concentrated within scientific fields than within industries. The paper also compares effects of different types of basic research on scientific output. The main finding is that the academic spillover effect significantly exceeds that of industrial spillovers or industry basic research. Finally, within field effects exceed between field effects, while the within- and between industry effects are equal. Therefore, scientific fields limit basic research flows more than industries.

    Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors, part 8

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    An experimental investigation was conducted with an 0.8 hub/tip ratio, single-stage, axial flow compressor to determine the potential of tandem-airfoil blading for improving the efficiency and stable operating range of compressor stages. The investigation included testing of a baseline stage with single-airfoil blading and two tandem-blade stages. The overall performance of the baseline stage and the tandem-blade stage with a 20-80% loading split was considerably below the design prediction. The other tandem-blade stage, which had a rotor with a 50-50% loading split, came within 4.5% of the design pressure rise (delta P(bar)/P(bar) sub 1) and matched the design stage efficiency. The baseline stage with single-airfoil blading, which was designed to account for the actual rotor inlet velocity profile and the effects of axial velocity ratio and secondary flow, achieved the design predicted performance. The corresponding tandem-blade stage (50-50% loading split in both blade rows) slightly exceeded the design pressure rise but was 1.5 percentage points low in efficiency. The tandem rotors tested during both phases demonstrated higher pressure rise and efficiency than the corresponding single-airfoil rotor, with identical inlet and exit airfoil angles

    An interface between a datametrics 1085A manometer and a Hewlett-Packard 2100S computer

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    A hardware/software interface designed to mate a Datametrics models 1085A electronic manometer to a Hewlett-Packard (HP) model 2100S computer is described. The software driver operates in the basic control system (BCS) and requires 173 words of memory; the hardware interface uses an HP data source interface (DSI) card which requires one computer input/output channel. Results obtained by incorporating this interface into a data acquisition system indicate that the interface operates successfully

    Standing on Academic Shoulders: Measuring Scientific Influence in Universities

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    This article measures scientific influence by means of citations to academic papers. The data source is the Institute for Scientific Information (ISI); the scientific institutions included are the top 110 U.S. research universities; the 12 main fields that classify the data cover nearly all of science; and the time period is 1981-1999. Altogether the database includes 2.4 million papers and 18.8 million citations. Thus the evidence underlying our findings accounts for much of the basic research conducted in the United States during the last quarter of the 20th century. This research in turn contributes a significant part of knowledge production in the U.S. during the same period. The citation measure used is the citation probability, which equals actual citations divided by potential citations, and captures average utilization of cited literature by individual citing articles. The mean citation probability within fields is on the order of 10-5. Cross-field citation probabilities are one-tenth to one-hundredth as large, or 10-6 to 10-7. Citations between pairs of citing and cited fields are significant in less than one-fourth of the possible cases. It follows that citations are largely bounded by field, with corresponding implications for the limits of scientific influence. Cross-field citation probabilities appear to be symmetric for mutually citing fields. Scientific influence is asymmetric within fields, and occurs primarily from top institutions to those less highly ranked. Still, there is significant reverse influence on higher-ranked schools. We also find that top institutions are more often cited by peer institutions than lower-ranked institutions are cited by their peers. Overall the results suggest that knowledge spillovers in basic science research are important, but are circumscribed by field and by intrinsic relevance. Perhaps the most important implication of the results are the limits that they seem to impose on the returns to scale in the knowledge production function for basic research, namely the proportion of available knowledge that spills over from one scientist to another.
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