11,318 research outputs found
Event sequence detector
An event sequence detector is described with input units, each associated with a row of bistable elements arranged in an array of rows and columns. The detector also includes a shift register which is responsive to clock pulses from any of the units to sequentially provide signals on its output lines each of which is connected to the bistable elements in a corresponding column. When the event-indicating signal is received by an input unit it provides a clock pulse to the shift register to provide the signal on one of its output lines. The input unit also enables all its bistable elements so that the particular element in the column supplied with the signal from the register is driven to an event-indicating state
A global low order spectral model designed for climate sensitivity studies
A two level, global, spectral model using pressure as a vertical coordinate is developed. The system of equations describing the model is nonlinear and quasi-geostrophic. A moisture budget is calculated in the lower layer only with moist convective adjustment between the two layers. The mechanical forcing of topography is introduced as a lower boundary vertical velocity. Solar forcing is specified assuming a daily mean zenith angle. On land and sea ice surfaces a steady state thermal energy equation is solved to calculate the surface temperature. Over the oceans the sea surface temperatures are prescribed from the climatological average of January. The model is integrated to simulate the January climate
High isolation RF signal selection switches
A selection switch with high isolation between RF signal input terminals is achieved with a gated Schmitt trigger circuit feeding into a control NAND gate in each signal switching channel. The control NAND gates of the separate signal channels are coupled to an output terminal by a single NAND gate. The schmitt trigger circuits and all gates are implemented with Schottky transistor-transistor logic circuits having input clamping diodes. Each Schmitt trigger circuit includes two cascaded NAND gates and a feedback isolation Schottky diode between one input terminal connected to receive an RF input and another input terminal connected to receive a feedback signal from the second of the two cascaded NAND gates. Both NAND gates of the Schmitt trigger circuits are enabled by the same switch control signal which enables the control gates
Method and apparatus for precision control of radiometer
A radiometer controller of a radiation detector is provided with a calibration method and apparatus comprised of mounting all temperature sensitive elements of the controller in thermostatically controlled ovens during calibration and measurements, using a selected temperature that is above any which might be reached in the field. The instrument is calibrated in situ by adjusting heater power (EI) to the receptor cavity in the radiometer detector to a predetermined full scale level and is displayed by a meter
Interpolating compact binary waveforms using the singular value decomposition
Compact binary systems with total masses between tens and hundreds of solar
masses will produce gravitational waves during their merger phase that are
detectable by second-generation ground-based gravitational-wave detectors. In
order to model the gravitational waveform of the merger epoch of compact binary
coalescence, the full Einstein equations must be solved numerically for the
entire mass and spin parameter space. However, this is computationally
expensive. Several models have been proposed to interpolate the results of
numerical relativity simulations. In this paper we propose a numerical
interpolation scheme that stems from the singular value decomposition. This
algorithm shows promise in allowing one to construct arbitrary waveforms within
a certain parameter space given a sufficient density of numerical simulations
covering the same parameter space. We also investigate how similar approaches
could be used to interpolate waveforms in the context of parameter estimation.Comment: 5 pages, 3 figures, presented at the joint 9th Edoardo Amaldi
Conference on Gravitational Waves and 2011 Numerical Relativity - Data
Analysis (NRDA) meetin
Teacher identity and professional identity tensions among primary student teachers:A focus on theory, measurement, and longitudinal associations
Each teacher training program aims at providing primary student teachers with abilities that will make them high-quality professionals determined to teach for a longer period of time. Helping student teachers build professional identities is fundamental to accomplish these goals. Successfully handling tensions that student teachers experience has been linked to forming their teacher identity. Most work underlying the connection between tensions and teacher identity is theoretical rather than empirical. Consequently, little is known about how the two constructs actually are related over time. Moreover, suitable and/or valid instruments for investigating the link between teacher identity and tensions are missing. The overarching goal of this dissertation, therefore, was first to develop reliable and valid measurement scales for teacher identity and professional identity tensions; and then advance our understanding of the development of the relationship between teacher identity and professional identity tensions across time in the context of primary teacher education. In pursuing this goal, four studies were conducted that together form the present dissertation. Study 1 (Chapter II) provides an overview of components of teacher identity that are found in quantitative measurement instruments and reports on the psychometric quality of these measurement instruments. The second study (Chapter III) presents the development and validation of the Teacher Identity Measurement Scale (TIMS). The third study (Chapter IV) describes the development and validation of the Professional Identity Tensions Scale (PITS). Finally, study 4 (Chapter V) examined the development of the relationship between teacher identity and professional identity tensions among primary student teachers across time
Teacher identity and professional identity tensions among primary student teachers:A focus on theory, measurement, and longitudinal associations
Friends and Enemies: Co-Belligerents and Prisoners of War at Camp Myles Standish, Taunton, Massachusetts during World War II
New England Pilots in the Lafayette Flying Corps
The Lafayette Flying Corps was the name given to a group of American pilots who flew with the French Air Service during World War 1. More than 200 Americans became expatriates, for a time at least, in order to try to qualify to fly the latest French fighter planes against the Germans. By war\u27s end the 180 who succeeded were serving in 93 French squadrons. Although most later transferred to the U.S. Air Service, it was their days in the Lafayette Flying Corps and its most elite squadron, the Lafayette Escadrille which recalled the fondest memories among survivors. Of the 180 Americans who flew with the Lafayette, 30 had lived all or part of their lives in New England. An examination of their careers will show that, although they did share certain attributes like courage, self-confidence and love of adventure, they were indeed a mixed crew, difficult to classify and largely indifferent to the glamour of knighthood
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