15,968 research outputs found
Medical applications of diamond magnetometry: commercial viability
The sensing of magnetic fields has important applications in medicine,
particularly to the sensing of signals in the heart and brain. The fields
associated with biomagnetism are exceptionally weak, being many orders of
magnitude smaller than the Earth's magnetic field. To measure them requires
that we use the most sensitive detection techniques, however, to be
commercially viable this must be done at an affordable cost. The current state
of the art uses costly SQUID magnetometers, although they will likely be
superseded by less costly, but otherwise limited, alkali vapour magnetometers.
Here, we discuss the application of diamond magnetometers to medical
applications. Diamond magnetometers are robust, solid state devices that work
in a broad range of environments, with the potential for sensitivity comparable
to the leading technologies.Comment: 10 pages, 1 figur
Capital Accumulation, Productivity and Growth
A consensus has emerged that the remarkable behavior of IT prices provides the key to the surge in US economic growth after 1995. The relentless decline in the prices of information technology equipment and software has steadily enhanced the role of IT investment. Productivity growth in IT-producing industries has risen in importance and a productivity revival is underway in the rest of the economy. The surge of IT investment in the United States after 1995 has counterparts in all other industrialized countries. It is essential to use comparable data and methodology in order to provide rigorous international comparisons. A crucial role is played by measurements of IT prices. The US national accounts have incorporated measures of IT prices that hold performance constant since 1985. Schreyer (2000) has extended these measures to other industrialized countries by constructing "internationally harmonized prices". The acceleration in the IT price decline in 1995 triggered a burst of IT investment in all of the G7 nations — Canada, France, Germany, Italy, Japan, the UK, as well as the US. These countries also experienced a rise in productivity growth in the IT-producing industries. However, differences in the relative importance of these industries have generated wide disparities in the impact of IT on economic growth. The role of the IT-producing industries is greatest in the US, which leads the G7 in output per capita.
Fifty Years of Economic Measurement: The Jubilee of the Conference on Research in Income and Wealth
Smart built-in test
The work which built-in test (BIT) is asked to perform in today's electronic systems increases with every insertion of new technology or introduction of tighter performance criteria. Yet the basic purpose remains unchanged -- to determine with high confidence the operational capability of that equipment. Achievement of this level of BIT performance requires the management and assimilation of a large amount of data, both realtime and historical. Smart BIT has taken advantage of advanced techniques from the field of artificial intelligence (AI) in order to meet these demands. The Smart BIT approach enhances traditional functional BIT by utilizing AI techniques to incorporate environmental stress data, temporal BIT information and maintenance data, and realtime BIT reports into an integrated test methodology for increased BIT effectiveness and confidence levels. Future research in this area will incorporate onboard fault-logging of BIT output, stress data and Smart BIT decision criteria in support of a singular, integrated and complete test and maintenance capability. The state of this research is described along with a discussion of directions for future development
General purpose computer program for interacting supersonic configurations: Programmer's manual
The program ISCON (Interacting Supersonic Configuration) is described. The program is in support of the problem to generate a numerical procedure for determining the unsteady dynamic forces on interacting wings and tails in supersonic flow. Subroutines are presented along with the complete FORTRAN source listing
General purpose computer program for interacting supersonic configurations. User's manual
The input data required to execute the computer program ISCON are described. The program generates a numerical procedure for the determination of unsteady aerodynamic forces on arbitrarily interacting wings and tails in supersonic flow. A velocity potential gradient method is used. Constant Mach number is assumed throughout the flow field. Lifting surfaces are represented by trapezoidal elements which can be generated automatically by the program. The wake field is represented by rectangular strip elements. The formulation is reviewed as well as input overview and input format. Instruction on how to use ISCON, a sample problem, and the restart feature are discussed. Program size limitations, computer program flow, and error messages are also included along with a description of the SS31 program used to compute the coefficients of surface spline
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