1,890 research outputs found
Review of Creativity and Chaos: Reflections on a Decade of Progressive Change in Public Schools, 1967-1977 by Charles Suhor
In the title of Charles Suhorâs engaging memoir, the words progressive, change, and creativityâeven chaosâwill I suspect light fires of the imagination for many progressively inclined teachers and other readers. That goes all the more for those of us who lived through the upheavals and exciting breakthroughs of the late â60s and â70s, who may also have fought battles, like the ones recounted by Suhor, on behalf of our own students and children, to bring progressive changes to schools and colleges. As a former professor of English and philosophy and co-chair (with my friend and colleague Irene Papoulis) of the Assembly for Expanded Perspectives on Learning, I have a special admiration for Charlie Suhorâs work as an educational reformer and his vision as one of the founders of this Assembly of creative teachers and scholars
Poetry and the Art of Meditation: Going behind the Symbols
Combining reader-response theory with spiritual teachings, this article explores how reading poetry may serve as an introduction to the art of meditation
Estimating Stochastic Volatility Models Using a Discrete Non-linear Filter. Working paper #3
Many approaches have been proposed for estimating stochastic volatility (SV) models, a number of which are filtering methods. While non-linear filtering methods are superior to linear approaches, non-linear filtering methods have not gained a wide acceptance in the econometrics literature due to their computational cost. This paper proposes a discretised non-linear filtering (DNF) algorithm for the estimation of latent variable models. It is shown that the DNF approach leads to significant computational gains relative to other procedures in the context of SV estimation without any associated loss in accuracy. It is also shown how a number of extensions to standard SV models can be accommodated within the DNF algorithm.non-linear filtering, stochastic volatility, state-space models, asymmetries, latent factors, two factor volatility models
Discretised Non-Linear Filtering for Dynamic Latent Variable Models: with Application to Stochastic Volatility
Filtering techniques are often applied to the estimation of dynamic latent variable models. However, these techniques are often based on a set assumptions which restrict models to be specified in a linear state-space form. Numerical filtering techniques have been propsed that avoid invoking such restrictive assumptions, thus permitting a wider class of latent variable models to be considered. This paper proposes an accurate yet computationally efficient numerical filtering algorithm (based on a discretisation of the state space) for estimating the general class of dynamic latent variable models. The empirical performance of this algorithm is considered within the context of the stochastic volatility model. It is found that the proposed algorithm outperforms a number of accepted procedures in terms of volatility forecastiNon-linear filtering, latent variable models, stochastic volatility, volatilitry forecasting
The NASA-ER2 meteorological measurement system: Instrumentaion, calibration and intercomparison results
The NASA ER-2 aircraft is used as a platform for high altitude atmospheric missions. The Meteorological Measurement System (MMS) was designed specifically for atmospheric research to provide accurate, fast response, in situ measurements of pressure, temperature, and the three dimensional wind vector. The MMS consists of three subsystems: an air motion sensing system to measure the velocity of the air with respect to the aircraft, a high resolution Inertial Navigation System (INS) to measure the velocity of the aircraft with respect to the Earth, and a Data Acquisition System, to sample, process and record the measured quantities. Details of each of these systems are given. The location of the MMS instrumentation is illustrated. The calibration of the MMS is discussed and results on an intercomparison of MMS measurements, Vaisala radiosonde observation and radar tracking data are given. An illustration of the MMS measurement of vertical wind is given
The meteorological measurement system on the NASA ER-2 aircraft
A Meteorological Measurement System (MMS) was designed for the high-altitude ER-2 aircraft (NASA 706). Through dedicated instrumentation installed on the aircraft and repeated calibrations, the MMS provides accurate in situ measurements of free-stream pressure, temperature, and the wind vector. The MMS has participated in two major high-altitude scientific expeditions, the Stratosphere-Troposphere Exchange Project (STEP) based in northern Australia and the Airborne Antarctic Ozone Experiment (AAOE) based in southern Chile. Key MMS subsystems are described. The MMS consists of a dedicated inertial navigation system (INS), a randome differential pressure system, a data acquisition system, and air data instrumentation. The MMS incorporates a high-resolution INS (Litton LIN-72RH model), which is specially configured and is updated at 25 Hz. The differential pressure system, consisting of two sets of pressure ports and transducers, is installed in the ER-2 radome to provide sensitive measurements of the airflow angles (angle of attack and angle of sideslip). The data acquisition system was designed to meet aircraft requirements of compactness and light weight (2 cu ft 50 lb) and for MMS requirements to sample, control, process, and store 45 parameters (some redundant) at a sampling rate up to 10 Hz. The MMS data are stored both in a tape recorder (20 MB) and a hermatically-sealed winchester hard disc (10 MB). Special and redundant instrumentation for temperature and pressure measurements were also installed on the aircraft
Temperature and horizontal wind measurements on the ER-2 aircraft during the 1987 airborne Antarctic ozone experiment
The NASA ER-2 aircraft is equipped with special instrumentation to provide accurate in situ measurement of the atmospheric state variables during flight. The Meteorological Measurement System (MMS) on the ER-2 aircraft is described. Since the meteorological parameters (temperature, pressure, and wind vector) are extensively used by other ER-2 experimenters for data processing and interpretation, the accuracy and resolution of each of these parameters are assessed and discussed. During the 1987 Airborne Antarctic Ozone Experiment (AAOE) mission, the ER-2 aircraft was stationed at Punta Arenas, Chile (53 S, 72 W), and successfully flew over Antarctica on 12 occasions between August 17 and September 22, 1987. On each of the 12 flights, the ER-2 aircraft flight plan was to take off at approximately the same local time, fly southward at a near constant potential temperature surface, descend and ascend at the southernmost terminus at about 72 S over Antarctica and return northward at either the same or a different constant potential temperature surface. The measurements of the MMS experiment during the AAOE mission are presented. MMS data are organized to provide a composite view of the polar atmosphere, which is characterized by frigid temperatures and high zonal winds. Altitudinal variations of the temperature measurement (during takeoff/landing at Punta Arenas and during descent/ascent at the southern terminus) and latitudinal variations of the zonal wind (on near constant potential temperature surfaces) are emphasized and discussed
Three-dimensional range imaging apparatus and method
A three-dimensional range imager includes a light source for providing a modulated light signal, a multiplexer, an optical fiber connecting the light source to the multiplexer, a plurality of optical fibers connected at first ends to the multiplexer and at second ends to a first fiber array, and a transmitter optic disposed adjacent the first fiber array for projecting a pixel pattern of the array onto a target
Paper Session II-C - The Space Life Sciences Lab at the Kennedy Space Center: A Critical Facility for Future Space Flight
On November 19, 2003, Jim Kennedy, KSC Center Director, Winston Scott, former Astronaut and Director of the Florida Space Authority, Dr. Sam Durrance, Director of the Florida Space Research Institute, and Lt. Governor Toni Jennings, dedicated the Space Life Sciences Lab at the Kennedy Space Center. The SLS Lab is a world-class laboratory with all the capability and systems necessary to host International Space Station experiment processing as well as associated biological and life sciences research. Areas include Biotechnology, Microgravity, Space Agriculture, Biomedicine, Conservation Biology, and Microbial Ecology. This unique facility was constructed under a partnership between the State and NASA and provides the capability for researchers from the research consortium led by FSRI and the University of Florida to work closely with NASA researchers and payload developers to make fundamental advances in our understanding of biological systems and lay the ground work for long duration human space missions. This paper describes the unique partnerships, goals, operating capabilities and initial research activities of this important and unique research facility
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