1,817 research outputs found
Transforming pre-service teacher curriculum: observation through a TPACK lens
This paper will discuss an international online collaborative learning experience through the lens of the Technological Pedagogical Content Knowledge (TPACK) framework. The teacher knowledge required to effectively provide transformative learning experiences for 21st century learners in a digital world is complex, situated and changing. The discussion looks beyond the opportunity for knowledge development of content, pedagogy and technology as components of TPACK towards the interaction between those three components. Implications for practice are also discussed. In today’s technology infused classrooms it is within the realms of teacher educators, practising teaching and pre-service teachers explore and address effective practices using technology to enhance learning
Working collaboratively on the digital global frontier
An international online collaborative learning experience was designed and implemented in preservice teacher education classes at the University of Calgary, Canada and the University of Southern Queensland, Australia. The project was designed to give preservice teachers an opportunity to live the experience of being online collaborators investigating real world teaching issues of diversity and inclusivity. Qualitative research was conducted to examine the complexity of the online collaborative experiences of participants. Redmond and Lock’s (2006) flexible online collaborative learning framework was used to explain the design and the implementation of the project. Henri’s (1992) content analysis model for computer-mediated communication was used for the online asynchronous postings and a constant comparative method of data analysis was used in the construction of themes. From the findings, the authors propose recommendations for designing and facilitating collaborative learning on the digital global frontier
Flight test of a resident backup software system
A new fault-tolerant system software concept employing the primary digital computers as host for the backup software portion has been implemented and flight tested in the F-8 digital fly-by-wire airplane. The system was implemented in such a way that essentially no transients occurred in transferring from primary to backup software. This was accomplished without a significant increase in the complexity of the backup software. The primary digital system was frame synchronized, which provided several advantages in implementing the resident backup software system. Since the time of the flight tests, two other flight vehicle programs have made a commitment to incorporate resident backup software similar in nature to the system described in this paper
Bistability and chaos at low-level of quanta
We study nonlinear phenomena of bistability and chaos at a level of few
quanta. For this purpose we consider a single-mode dissipative oscillator with
strong Kerr nonlinearity with respect to dissipation rate driven by a
monochromatic force as well as by a train of Gaussian pulses. The quantum
effects and decoherence in oscillatory mode are investigated on the framework
of the purity of states and the Wigner functions calculated from the master
equation. We demonstrate the quantum chaotic regime by means of a comparison
between the contour plots of the Wigner functions and the strange attractors on
the classical Poincar\'e section. Considering bistability at low-limit of
quanta, we analyze what is the minimal level of excitation numbers at which the
bistable regime of the system is displayed? We also discuss the formation of
oscillatory chaotic regime by varying oscillatory excitation numbers at ranges
of few quanta. We demonstrate quantum-interference phenomena that are assisted
hysteresis-cycle behavior and quantum chaos for the oscillator driven by the
train of Gaussian pulses as well as we establish the border of
classical-quantum correspondence for chaotic regimes in the case of strong
nonlinearities.Comment: 10 pages, 14 figure
An experimental study of permeability determination in the lab
Understanding the flow characteristics in laminar and turbulent flow regime is important for different aspects of reservoir and production engineering. One of the most important parameters in fluid flow is the permeability of the porous media. It is common practice in the industry to use Darcy and Forchheimers equations for characterising the fluid flow in the porous media at laminar and turbulent regimes, respectively. Core flooding experiments were performed with 1.5-inch diameter size core samples from limestone and sandstone formations. The permeability of the samples was measured in the laminar regime at basis flow rate. Then, the flow rate was increased in different steps and permeability was measured, accordingly. The plot of permeability versus flow rate was used to track the evolution of the flow regimes in the core porous media. There are different challenges to monitor the transition between laminar and turbulent regime through core flooding experiments. These challenges are discussed in this paper through both literature review and also experimental results. The results indicated that the core sample preparation, experiment control parameters and also test profiles are important aspects when measuring permeability in the lab. © 2012 WIT Press
Experimental Visualization of Dispersion Characteristics of Backward Volume Spin Wave Modes
Basing on the measurement of spatial spectra (spectra of wavenumbers), the
dispersion characteristics of the first three modes of backward volume spin
wave, propagating along the direction of a constant uniform magnetic field in a
tangentially magnetized ferrite film, were visualized firstly. The study was
carried out by microwave probing of spin waves with subsequent use of spatial
Fourier analysis of the complex wave amplitude for a series of frequencies. It
was found that every m-th mode of the backward volume spins wave can be split
into n satellite modes due to the existence of layers with similar magnetic
parameters in ferrite film. It was found that satellites of the first mode of
this wave are excited most effectively, while satellites of the third mode -
least effectively, and the effectiveness of satellites excitation decreases as
the number n increases. It is found that the theoretical dispersion
dependencies of the first three modes of the wave coincide well with the
experimental dispersion dependencies of the satellite mode that are excited
most effectively.Comment: 14 pages, 5 figure
On the nature of long range electronic coupling in a medium: Distance and orientational dependence for chromophores in molecular aggregates
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