Fiscal Update, March 28, 2005

The Fiscal Division newsletter, published weekly during session and periodically during the interim

Model calculations of possible ionospheric backscatter echo area for a mid-latitude HF radar

HF ray path calculation is performed in order to identify possible ionospheric backscatter echo area for an HF radar at mid-latitude. The calculation is made on the basis of the R.M. Jones and J.J. Stephenson (U.S. Dept. of Commerce, OT Rep. 75-76, 1975) HF ray path tracing algorithm plus the IRI-2001 ionosphere model. It is shown that depending on the local time and geomagnetic activity, the possible ionospheric backscatter regions have different distributions. In any case the backscatter region is large enough, indicating the capability of a planned HF radar in Hokkaido (43.5°N, 143.6°E), Japan

On Recommendation of Learning Objects using Felder-Silverman Learning Style Model

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The e-learning recommender system in learning institutions is increasingly becoming the preferred mode of delivery, as it enables learning anytime, anywhere. However, delivering personalised course learning objects based on learner preferences is still a challenge. Current mainstream recommendation algorithms, such as the Collaborative Filtering (CF) and Content-Based Filtering (CBF), deal with only two types of entities, namely users and items with their ratings. However, these methods do not pay attention to student preferences, such as learning styles, which are especially important for the accuracy of course learning objects prediction or recommendation. Moreover, several recommendation techniques experience cold-start and rating sparsity problems. To address the challenge of improving the quality of recommender systems, in this paper a novel recommender algorithm for machine learning is proposed, which combines students actual rating with their learning styles to recommend Top-N course learning objects (LOs). Various recommendation techniques are considered in an experimental study investigating the best technique to use in predicting student ratings for e-learning recommender systems. We use the Felder-Silverman Learning Styles Model (FSLSM) to represent both the student learning styles and the learning object profiles. The predicted rating has been compared with the actual student rating. This approach has been experimented on 80 students for an online course created in the MOODLE Learning Management System, while the evaluation of the experiments has been performed with the Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). The results of the experiment verify that the proposed approach provides a higher prediction rating and significantly increases the accuracy of the recommendation

Cohesive energies of cubic III-V semiconductors

Cohesive energies for twelve cubic III-V semiconductors with zincblende structure have been determined using an ab-initio scheme. Correlation contributions, in particular, have been evaluated using the coupled-cluster approach with single and double excitations (CCSD). This was done by means of increments obtained for localized bond orbitals and for pairs and triples of such bonds. Combining these results with corresponding Hartree-Fock data, we recover about 92 \% of the experimental cohesive energies.Comment: 16 pages, 1 figure, late

Fiscal Update, March 16, 2006

The Fiscal Division newsletter, published weekly during session and periodically during the interim

Review of targeted small business procurement activities for the year ended June 30, 2008

Review of targeted small business procurement activities for the year ended June 30, 200

Optimizing the fast Rydberg quantum gate

The fast phase gate scheme, in which the qubits are atoms confined in sites of an optical lattice, and gate operations are mediated by excitation of Rydberg states, was proposed by Jaksch et al. Phys. Rev. Lett. 85, 2208 (2000). A potential source of decoherence in this system derives from motional heating, which occurs if the ground and Rydberg states of the atom move in different optical lattice potentials. We propose to minimize this effect by choosing the lattice photon frequency \omega so that the ground and Rydberg states have the same frequency-dependent polarizability \alpha(omega). The results are presented for the case of Rb.Comment: 5 pages, submitted to PR

Fiscal Update, February 24, 2003

The Fiscal Division newsletter, published weekly during session and periodically during the interim