132 research outputs found
The effect of using facebook markup language (fbml) for designing an e-learning model in higher education
This study examines the use of Facebook Markup Language (FBML) to design an
e-learning model to facilitate teaching and learning in an academic setting.
The qualitative research study presents a case study on how, Facebook is used
to support collaborative activities in higher education. We used FBML to design
an e-learning model called processes for e-learning resources in the Specialist
Learning Resources Diploma (SLRD) program. Two groups drawn from the SLRD
program were used; First were the participants in the treatment group and
second in the control group. Statistical analysis in the form of a t-test was
used to compare the dependent variables between the two groups. The findings
show a difference in the mean score between the pre-test and the post-test for
the treatment group (achievement, the skill, trends). Our findings suggest that
the use of FBML can support collaborative knowledge creation and improved the
academic achievement of participatns. The findings are expected to provide
insights into promoting the use of Facebook in a learning management system
(LMS).Comment: Mohammed Amasha, Salem Alkhalaf, "The Effect of using Facebook Markup
Language (FBML) for Designing an E-Learning Model in Higher Education".
International Journal of Research in Computer Science, 4 (5): pp. 1-9,
January 201
A Model of an E-Learning Web Site for Teaching and Evaluating Online
This research is endeavoring to design an e-learning web site on the internet
having the course name as "Object Oriented Programming" (OOP) for the students
of level four at Computer Science Department (CSD). This course is to be taught
online (through web) and then a programme is to be designed to evaluate
students performance electronically while introducing a comparison between
online teaching , e-evaluation and traditional methods of evaluation. The
research seeks to lay out a futuristic perception that how the future online
teaching and e-electronic evaluation should be the matter which highlights the
importance of this research
Quantum dot behavior in graphene nanoconstrictions
Graphene nanoribbons display an imperfectly understood transport gap. We
measure transport through nanoribbon devices of several lengths. In nanoribbons
of length greater than or equal to 250 nm we observe transport through multiple
quantum dots in series, while shorter constrictions of length less than or
equal to 60 nm display behavior characteristic of single and double quantum
dots. Dot size scales with constriction width. We propose a model where
transport occurs through quantum dots that are nucleated by background disorder
potentials in the presence of a confinement gap.Comment: published version: 24 pages, 9 figures (includes supplementary
information
Single spin universal Boolean logic
Recent advances in manipulating single electron spins in quantum dots have
brought us close to the realization of classical logic gates based on
representing binary bits in spin polarizations of single electrons. Here, we
show that a linear array of three quantum dots, each containing a single spin
polarized electron, and with nearest neighbor exchange coupling, acts as the
universal NAND gate. The energy dissipated during switching this gate is the
Landauer-Shannon limit of kTln(1/p) [T = ambient temperature and p = intrinsic
gate error probability]. With present day technology, p = 1E-9 is achievable
above 1 K temperature. Even with this small intrinsic error probability, the
energy dissipated during switching the NAND gate is only ~ 21 kT, while today's
nanoscale transistors dissipate about 40,000 - 50,000 kT when they switch
Electron tunneling and spin relaxation in a lateral quantum dot
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2008.Includes bibliographical references (p. 149-158).We report measurements that use real-time charge sensing to probe a single-electron lateral quantum dot. The charge sensor is a quantum point contact (QPC) adjacent to the dot and the sensitivity is comparable to other QPC-based systems. We develop an automated feedback system to position the energies of the states in the dot with respect to the Fermi energy of the leads. We also develop a triggering system to identify electron tunneling events in real-time data. Using real-time charge sensing, we measure the rate at which an electron tunnels onto or off of the dot. In zero magnetic field, we find that these rates depend exponentially on the voltages applied to the dot. We show that this dependence is consistent with a model that assumes elastic tunneling and accounts for the changes in the energies of the states in the dot relative to the heights of the tunnel barriers. In a parallel magnetic field B the spin states are split by the Zeeman energy and we measure the ratio of the rates for tunneling into the excited and ground spin states of an empty dot. We find that the ratio decreases with increasing B. However, by adjusting the voltages on the surface gates to change the orbital configuration of the dot, we restore tunneling into the excited spin state. We also measure the spin relaxation rate W - TI-l between the Zeeman split spin states for a single electron confined in the dot. At B = 1 T we find that TI > 1 s. The dependence of W on magnetic field is a power-law, and the exponent is consistent with the prediction for the spin relaxation mechanism of spin-orbit mediated coup)ling to piezoelectric phonons. Since spin relaxation involves the orbital states of the (lot via the spin-orbit interaction, we can achieve electrical control over WI by using the surface gates to manipulate the orbital states.(cont.) We demonstrate that we can vary Wt by over an order of magnitude at fixed Zeeman splitting, and we extract the spin-orbit length, which describes the strength of the spin-orbit interaction in GaAs.by Sami Amasha.Ph.D
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