678 research outputs found
An Application of the Delphi Method of Forecasting to the Future of Public Education in West Virginia
This study investigated the nature and types of events that will affect the future of public education in West Virginia. A three round modified Delphi design was used to identify the events, estimate when each might occur, and determine their level of impact and desirability.
In Round 1, surveys were mailed to forty-seven educational leaders representing various educational agencies and constituencies in West Virginia. In response to the first survey, panelists generated a total of one hundred thirty-four events which had at least a 50 percent probability of occurrence between the present and the year 2020. In Round 2, panelists were asked to predict the time frame of occurrence, and the level of impact and desirability for each event generated in Round 1. Round 3 results identified a total of forty-seven events which 80 percent of the panel members indicated would occur.
The total return of surveys was 89.4 percent in Round 1, 91.5 percent in Round 2, and 89.4 percent in Round 3. A total of 83.0 percent of the panelists participated in all three rounds of the Delphi.
A scenario was constructed based on the time frames of the events. Time frames were organized according to topical areas including Students, Personnel, Curriculum, Governance, Finance, Facilities, School-Community Relations, Technology and Miscellaneous. Levels of impact and desirability for each event were identified within each topical area.
Seven long term trends were identified which should be of significant importance to iii educators and educational planners. Among these trends are that (1) accountability and expectations for student achievement and behavior will increase; (2) schools will play an increasing role in the resolution of the problems of society; (3) a projected teacher shortage will affect changes in funding and staffing patterns; (4) public education will experience increasing competition from the private sector; (5) technology will play an increasing role in the education process; (6) new systems of financing public education will be developed, and (7) there will be continued emphasis on improving and replacing school facilities throughout West Virginia
Evanescent-wave trapping and evaporative cooling of an atomic gas near two-dimensionality
A dense gas of cesium atoms at the crossover to two-dimensionality is
prepared in a highly anisotropic surface trap that is realized with two
evanescent light waves. Temperatures as low as 100nK are reached with 20.000
atoms at a phase-space density close to 0.1. The lowest quantum state in the
tightly confined direction is populated by more than 60%. The system offers
intriguing prospects for future experiments on degenerate quantum gases in two
dimensions
Nonperturbative and perturbative treatments of parametric heating in atom traps
We study the quantum description of parametric heating in harmonic potentials
both nonperturbatively and perturbatively, having in mind atom traps. The first
approach establishes an explicit connection between classical and quantum
descriptions; it also gives analytic expressions for properties such as the
width of fractional frequency parametric resonances. The second approach gives
an alternative insight into the problem and can be directly extended to take
into account nonlinear effects. This is specially important for shallow traps.Comment: 12 pages, 2 figure
Very long storage times and evaporative cooling of cesium atoms in a quasi-electrostatic dipole trap
We have trapped cesium atoms over many minutes in the focus of a CO-laser
beam employing an extremely simple laser system. Collisional properties of the
unpolarized atoms in their electronic ground state are investigated. Inelastic
binary collisions changing the hyperfine state lead to trap loss which is
quantitatively analyzed. Elastic collisions result in evaporative cooling of
the trapped gas from 25 K to 10 K over a time scale of about 150 s.Comment: 5 pages, 3 figure
All Optical Formation of an Atomic Bose-Einstein Condensate
We have created a Bose-Einstein condensate of 87Rb atoms directly in an
optical trap. We employ a quasi-electrostatic dipole force trap formed by two
crossed CO_2 laser beams. Loading directly from a sub-doppler laser-cooled
cloud of atoms results in initial phase space densities of ~1/200.
Evaporatively cooling through the BEC transition is achieved by lowering the
power in the trapping beams over ~ 2 s. The resulting condensates are F=1
spinors with 3.5 x 10^4 atoms distributed between the m_F = (-1,0,1) states.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let
Cooling atoms in an optical trap by selective parametric excitation
We demonstrate the possibility of energy-selective removal of cold atoms from
a tight optical trap by means of parametric excitation of the trap vibrational
modes. Taking advantage of the anharmonicity of the trap potential, we
selectively remove the most energetic trapped atoms or excite those at the
bottom of the trap by tuning the parametric modulation frequency. This process,
which had been previously identified as a possible source of heating, also
appears to be a robust way for forcing evaporative cooling in anharmonic traps.Comment: 5 pages, 5 figure
Entanglement of atoms via cold controlled collisions
We show that by using cold controlled collisions between two atoms one can
achieve conditional dynamics in moving trap potentials. We discuss implementing
two qubit quantum--gates and efficient creation of highly entangled states of
many atoms in optical lattices.Comment: 4 pages 3 figure
"Siehst Du mich?" - "Hörst Du mich?": Videokonferenzen als Gegenstand kommunikationswissenschaftlicher Forschung
"Mit neuen Kommunikationstechnologien sind stets veränderte Verwirklichungsbedingungen von Mitteilungsprozessen verbunden. Die in diesem Artikel thematisierte Videokonferenz, eine Form audiovisueller Fernkommunikation, wird als ein spezifischer Fall interpersoneller Kommunikation begriffen und auf ihre Bedingungen, Realisierungsformen und -zwecke hin untersucht. Sie lässt sich verstehen als eigenständige Kommunikationsform, die durch a) die technischen Realisierungsbedingungen, b) die Leistungen und Kompetenzen der Kommunikationspartner und schließlich c) die jeweils verfolgten Kommunikationszwecke bestimmt werden kann." (Autorenreferat
Motional Squashed States
We show that by using a feedback loop it is possible to reduce the
fluctuations in one quadrature of the vibrational degree of freedom of a
trapped ion below the quantum limit. The stationary state is not a proper
squeezed state, but rather a ``squashed'' state, since the uncertainty in the
orthogonal quadrature, which is larger than the standard quantum limit, is
unaffected by the feedback action.Comment: 8 pages, 2 figures, to appear in the special Issue "Quantum
Correlations and Fluctuations" of J. Opt.
Multiple micro-optical atom traps with a spherically aberrated laser beam
We report on the loading of atoms contained in a magneto-optic trap into
multiple optical traps formed within the focused beam of a CO_{2} laser. We
show that under certain circumstances it is possible to create a linear array
of dipole traps with well separated maxima. This is achieved by focusing the
laser beam through lenses uncorrected for spherical aberration. We demonstrate
that the separation between the micro-traps can be varied, a property which may
be useful in experiments which require the creation of entanglement between
atoms in different micro-traps. We suggest other experiments where an array of
these traps could be useful.Comment: 10 pages, 3 figure
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