4,380 research outputs found
Time synchronization system utilizing moon reflected coded signals Patent
Time synchronization system for synchronizing clocks at remote locations with master clock using moon reflected coded signal
Two-carrier command modulation system
Two carriers transmit two high-power signals from single transmitter, each phase-modulated by subcarrier which, in turn, is modulated by data bits; switching between two carriers is alternated at high rate. Resulting composite signal is multiplied up to desired frequency and used to drive power amplifier which feeds transmitting antenna
Two carrier communication system with single transmitter
A pulse code modulated communication system is disclosed for transmitting two subcarrier modulated carriers from a single transmitter comprising two channels for phase modulating the two carriers independently. The modulating subcarriers are independently modulated by data and/or pseudonoise (PN) codes as desired. The modulated carriers are switched alternately to the single transmitter in synchronism with operation of a PN code generator when PN code modulation is present, as for ranging
Determination of composite slab strength using a new elemental test method
Composite slabs utilizing cold-formed profiled steel decks are commonly used for floor systems in steel framed buildings. The behavior and strength of composite slabs are normally controlled by the horizontal shear bond between the steel deck and the concrete. The strength of the horizontal shear bond depends on many factors and it is not possible to provide representative design values that can be applied to all slab conditions a priori. Thus, present design standards require that the design parameters be obtained from full-size bending tests, which are typically one or two deck panels wide and a single span. However, because these full-size tests can be expensive and time consuming, smaller size specimens, referred to as elemental tests, are desirable and have been the subject of a great deal of research. Details for a new elemental test method for composite slab specimens under bending are presented. Test results consisting of maximum applied load, end slips, and failure modes are presented and compared with the results of full-size specimens with similar end details, spans, etc. It is shown that the performance of the elemental test developed in this study is in good agreement with the performance of the full-size specimens. Application of test data to current design specifications is also presented
Using Evaluation to Improve Grantmaking: What's Good for the Goose is Good for the Grantor
Over the past decade, evaluation has become an increasingly prominent (albeit vexing) function within philanthropy. More and more foundations are beginning to devote at least minimal levels of resources to evaluate the programs they fund. The topic of evaluation appears more and more at professional conferences. Membership in Grantmakers Evaluation Network -- an "affinity group" of foundation representatives interested in promoting evaluation -- has mushroomed to over 400. As the "demand" for evaluation has increased among foundations, the market has begun to fill up with a mixed bag of consultants (from both academia and the private sector) willing to supply their services. Particularly this last indicator suggests that evaluation will take root in the philanthropic sector. Yet, although evaluation is becoming a more popular activity among foundations, its potential is far from being realized
Nuclear Waste and Native America: The MRS Siting Exercise
Drs. Gowda & Easterling provide cross-cultural perspectives on issues of risk perception, equity and policy as they affect nuclear waste storage on Native American sites
The effect of the interplanetary medium on s-band telecommunications
Effect of interplanetary medium on S-band telecommunication
Baseband signal combiner for large aperture antenna array
The invention provides a means whereby the baseband output signals of all but one of the receivers associated with each of the antennas are summed and used as a correlation reference for the baseband signal not contained in the summed signal, thereby providing a plurality of correlation or alignment loops, each having an output signal related to the phase difference between its input baseband signal and the summed signal. The invention further provides a means for subtracting an output or error signal generated in one of the correlation loops whose baseband signal has a predetermined phase delay from all the other alignment loops, thereby avoiding interaction and reflection effects in the signal combiner. A variable phase delay means for each of the other baseband signals is controlled by its corresponding correlation loop
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