39,581 research outputs found

    Self-calibrating threshold detector

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    A self calibrating threshold detector comprises a single demodulating channel which includes a mixer having one input receiving the incoming signal and another input receiving a local replica code. During a short time interval, an incorrect local code is applied to the mixer to incorrectly demodulate the incoming signal and to provide a reference level that calibrates the noise propagating through the channel. A sample and hold circuit is coupled to the channel for storing a sample of the reference level. During a relatively long time interval, the correct replica code provides an output level which ranges between the reference level and a maximum level that represents incoming signal presence and synchronism with the replica code. A summer substracts the stored sample reference from the output level to provide a resultant difference signal indicative of the acquisition of the expected signal

    The screwworm eradication data system archives

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    The archives accumulated during 1 year of operation of the Satellite Temperature-Monitoring System during development of the Screwworm Eradication Data System are reported. Brief descriptions of all the kinds of tapes, as well as their potential uses, are presented. Reference is made to other documents that explain the generation of these data

    Optimisation of confinement in a fusion reactor using a nonlinear turbulence model

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    The confinement of heat in the core of a magnetic fusion reactor is optimised using a multidimensional optimisation algorithm. For the first time in such a study, the loss of heat due to turbulence is modelled at every stage using first-principles nonlinear simulations which accurately capture the turbulent cascade and large-scale zonal flows. The simulations utilise a novel approach, with gyrofluid treatment of the small-scale drift waves and gyrokinetic treatment of the large-scale zonal flows. A simple near-circular equilibrium with standard parameters is chosen as the initial condition. The figure of merit, fusion power per unit volume, is calculated, and then two control parameters, the elongation and triangularity of the outer flux surface, are varied, with the algorithm seeking to optimise the chosen figure of merit. A two-fold increase in the plasma power per unit volume is achieved by moving to higher elongation and strongly negative triangularity.Comment: 32 pages, 8 figures, accepted to JP

    Heat Capacity Mapping Radiometer (HCMR) data processing algorithm, calibration, and flight performance evaluation

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    The rationale and procedures used in the radiometric calibration and correction of Heat Capacity Mapping Mission (HCMM) data are presented. Instrument-level testing and calibration of the Heat Capacity Mapping Radiometer (HCMR) were performed by the sensor contractor ITT Aerospace/Optical Division. The principal results are included. From the instrumental characteristics and calibration data obtained during ITT acceptance tests, an algorithm for post-launch processing was developed. Integrated spacecraft-level sensor calibration was performed at Goddard Space Flight Center (GSFC) approximately two months before launch. This calibration provided an opportunity to validate the data calibration algorithm. Instrumental parameters and results of the validation are presented and the performances of the instrument and the data system after launch are examined with respect to the radiometric results. Anomalies and their consequences are discussed. Flight data indicates a loss in sensor sensitivity with time. The loss was shown to be recoverable by an outgassing procedure performed approximately 65 days after the infrared channel was turned on. It is planned to repeat this procedure periodically

    Sex Offender Treatment Program: Initial Recidivism Study

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    This report presents results of a recidivism study of participants in the Sex Offender Treatment Program at Hiland Mountain Correctional Center, Alaska Department of Corrections, from January 1987 to August 1995. The report provides an overview and history of sex offender treatment in Alaska as well as a literature review of other studies and findings on this area of treatment. The Alaska study, which was the first conducted of the treatment program, found that any level of treatment achieved resulted in less recidivism, with the longer the period of treatment, the lower the recidivism. The study also noted the high percentage of Alaska Natives in the program and the history of alcohol and substance abuse presented by many sex offenders. The majority of offenders in the program were guilty of assaulting children. The study discusses the program's cost benefits as well as the implications of its findings for probation and parole.Alaska Department of CorrectionsI. Introduction / II. Sex Offender Treatment in Alaska / III. Literature Review / IV. Methodology / V. Results / VI. Conclusions and Recommendations / VII. Reference

    Decision Making Towards Maternal Health Services in Central Java, Indonesia

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    Background: Indonesia has always been struggling with maternal health issue even after the Millennium Development Goals (MDGs) programs were done. Prior research findings identified many factors which influenced maternal health status in developing countries such Indonesia and even though various efforts had been made, the impact of the transformation of maternal health behavior was minimal.Purpose: This study aimed to seek an understanding of the factors influencing decisions towards maternal health services.Methods: A case study with a single case embedded design was employed. Interviews and Focus Group Discussions (FGDs) were held to collect data from 3 health workers and 40 maternal women in a sub-district in Central Java, Indonesia.Results: Interviews with the village midwives as the main health providers in the Getasan sub-district concluded that there were several factors influencing the women\u27s decisions towards maternal services. The factors were options to have services with other health workers outside the area, and shaman services as alternative care and family influencing maternal health behaviors. The analysis of the FGDs also supported the village midwives\u27 statements that in spite of their awareness towards the available maternal health services, the existence of shamans and traditional beliefs strongly affected their decision.Conclusion: The findings in this study showed that cultural issues prevented the maximum maternal health status in Getasan sub-district. This study recommends Puskesmas (Primary Health Care) as the first level of health institutions in Indonesia to support the village midwives\u27 roles within their target area

    High-m Kink/Tearing Modes in Cylindrical Geometry

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    The global ideal kink equation, for cylindrical geometry and zero beta, is simplified in the high poloidal mode number limit and used to determine the tearing stability parameter, Δ′\Delta^\prime. In the presence of a steep monotonic current gradient, Δ′\Delta^\prime becomes a function of a parameter, σ0\sigma_0, characterising the ratio of the maximum current gradient to magnetic shear, and xsx_s, characterising the separation of the resonant surface from the maximum of the current gradient. In equilibria containing a current "spike", so that there is a non-monotonic current profile, Δ′\Delta^\prime also depends on two parameters: κ\kappa, related to the ratio of the curvature of the current density at its maximum to the magnetic shear, and xsx_s, which now represents the separation of the resonance from the point of maximum current density. The relation of our results to earlier studies of tearing modes and to recent gyro-kinetic calculations of current driven instabilities, is discussed, together with potential implications for the stability of the tokamak pedestal.Comment: To appear in Plasma Physics and Controlled Fusio

    Matrix elements of atomic interaction operators for d sup n configurations

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    Tabulation of matrix elements of atomic interaction operators for various configuration
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