16,387 research outputs found
Mixing and Matching Learning Design and Learning Analytics
In the last five years, learning analytics has proved its potential in predicting academic performance based on trace data of learning activities. However, the role of pedagogical context in learning analytics has not been fully understood. To date, it has been difficult to quantify learning in a way that can be measured and compared. By coding the design of e-learning courses, this study demonstrates how learning design is being implemented on a large scale at the Open University UK, and how learning analytics could support as well as benefit from learning design. Building on our previous work, our analysis was conducted longitudinally on 23 undergraduate distance learning modules and their 40,083 students. The innovative aspect of this study is the availability of fine-grained learning design data at individual task level, which allows us to consider the connections between learning activities, and the media used to produce the activities. Using a combination of visualizations and social network analysis, our findings revealed a diversity in how learning activities were designed within and between disciplines as well as individual learning activities. By reflecting on the learning design in an explicit manner, educators are empowered to compare and contrast their design using their own institutional data
Efficient ARQ retransmission schemes for two-way relay networks.
In this paper, we investigate different practical automatic repeat request (ARQ) retransmission protocols for two-way wireless relay networks based on network coding (NC). The idea of NC is applied to increase the achievable throughput for the exchange of information between two terminals through one relay. Using NC, throughput efficiency is significantly improved due to the reduction of the number of retransmissions. Particularly, two improved NC-based ARQ schemes are designed based on go-back-N and selective-repeat (SR) protocols. The analysis of throughput efficiency is then carried out to find the best retransmission strategy for different scenarios. It is shown that the combination of improved NC-based SR ARQ scheme in the broadcast phase and the traditional SR ARQ scheme in the multiple access phase achieves the highest throughput efficiency compared to the other combinations of ARQ schemes. Finally, simulation results are provided to verify the theoretical analysis
A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda : Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam
A new root-knot nematode, parasitizing Robusta coffee in Dak Lak Province, Western Highlands of Vietnam, is described as Meloidogyne moensi n. sp. Morphological and molecular analyses demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by a swollen body of females with a small posterior protuberance that elongated from ovoid to saccate; perineal patterns with smooth striae, continuous and low dorsal arch; lateral lines marked as a faint space or linear depression at junction of the dorsal and ventral striate; distinct phasmids; perivulval region free of striae; visible and wide tail terminus surrounding by concentric circles of striae; medial lips of females in dumbbell-shaped and slightly raised above lateral lips; female stylet is normally straight with posteriorly sloping stylet knobs; lip region of second stage juvenile (J2) is not annulated; medial lips and labial disc of J2 formed dumbbell shape; lateral lips are large and triangular; tail of J2 is conoid with rounded unstriated tail tip; distinct phasmids and hyaline; dilated rectum. Meloidogyne moensi n. sp. is most similar to M. africana, M. ottersoni by prominent posterior protuberance. Results of molecular analysis of rDNA sequences including the D2-D3 expansion regions of 28S rDNA, COI, and partial COII/16S rRNA of mitochondrial DNA support for the new species status
Are time preference and risk preference associated with cognitive intelligence and emotional intelligence?
The authors investigated whether cognitive intelligence (intelligence quotient [IQ]) and emotional intelligence (emotional quotient [EQ]) meaningfully correlate with time preference and risk preference, finding solid evidence in support. In the realm of time preference, high-EQ individuals are less subject to present (or future) bias and more patient. Further, high-IQ subjects tend to exhibit preferences that conform to expected utility maximization. While recent research on the relationship between cognitive ability and preferences has provided important insights, the results suggest that both cognitive intelligence and emotional intelligence matter
Sustainable Growth and Ethics: a Study of Business Ethics in Vietnam Between Business Students and Working Adults
Sustainable growth is not only the ultimate goal of business corporations but also the primary target of local governments as well as regional and global economies. One of the cornerstones of sustainable growth is ethics. An ethical organizational culture provides support to achieve sustainable growth. Ethical leaders and employees have great potential for positive influence on decisions and behaviors that lead to sustainability. Ethical behavior, therefore, is expected of everyone in the modern workplace. As a result, companies devote many resources and training programs to make sure their employees live according to the high ethical standards. This study provides an analysis of Vietnamese business students’ level of ethical maturity based on gender, education, work experience, and ethics training. The results of data from 260 business students compared with 704 working adults in Vietnam demonstrate that students have a significantly higher level of ethical maturity. Furthermore, gender and work experience are significant factors in ethical maturity. While more educated respondents and those who had completed an ethics course did have a higher level of ethical maturity, the results were not statistically significant. Analysis of the results along with suggestions and implications are provided
Quantum Gates with Oscillating Exchange Interaction
Two-qubit gates between spin qubits are often performed using a rectangular
or an adiabatic exchange interaction pulse resulting in a CZ gate. An
oscillating exchange pulse not only performs a CZ gate, but also enables the
iSWAP gate, which offers more flexibility to perform quantum algorithms. We
provide a detailed description for two-qubit gates using resonant and
off-resonant exchange pulses, give conditions for performing the respective
gates, and compare their performance to the state-of-the-art static
counterpart. We find that for relatively low charge noise the gates still
perform reliably and can outperform the conventional CZ gate
Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects
Experimental investigation of wing flexibility on vertical thrust generation and power consumption in hovering condition for a hovering Flapping-Wing Micro Air Vehicle, namely FlowerFly, weighing 14.5 g with a 3 g onboard battery and having four wings with double wing clap-and-fling effects, was conducted for several wing configurations with the same shape, area, and weight. A data acquisition system was set up to simultaneously record aerodynamic forces, electrical power consumption, and wing motions at various flapping frequencies. The forces and power consumption were measured with a loadcell and a custom-made shunt circuit, respectively, and the wing motion was captured by high-speed cameras. The results show a phase delay of the wing tip displacement observed for wings with high flexible leading edge at high frequency, resulting in less vertical thrust produced when compared with the wings with less leading edge flexibility at the same flapping frequency. Positive wing camber was observed during wing flapping motion by arranging the wing supporting ribs. Comparison of thrust-to-power ratios between the wing configurations was undertaken to figure out a wing configuration for high vertical thrust production but less power consumption
Anisotropic Magneto-Thermopower: the Contribution of Interband Relaxation
Spin injection in metallic normal/ferromagnetic junctions is investigated
taking into account the anisotropic magnetoresistance (AMR) occurring in the
ferromagnetic layer. It is shown, on the basis of a generalized two channel
model, that there is an interface resistance contribution due to anisotropic
scattering, beyond spin accumulation and giant magnetoresistance (GMR). The
corresponding expression of the thermopower is derived and compared with the
expression for the thermopower produced by the GMR. First measurements of
anisotropic magnetothermopower are presented in electrodeposited Ni nanowires
contacted with Ni, Au and Cu. The results of this study show that while the
giant magnetoresistance and corresponding thermopower demonstrates the role of
spin-flip scattering, the observed anisotropic magnetothermopower indicates
interband s-d relaxation mechanisms.Comment: 20 pages, 4 figure
Direct measurements of DOCO isomers in the kinetics of OD+CO
Quantitative and mechanistically-detailed kinetics of the reaction of
hydroxyl radical (OH) with carbon monoxide (CO) have been a longstanding goal
of contemporary chemical kinetics. This fundamental prototype reaction plays an
important role in atmospheric and combustion chemistry, motivating studies for
accurate determination of the reaction rate coefficient and its pressure and
temperature dependence at thermal reaction conditions. This intricate
dependence can be traced directly to details of the underlying dynamics
(formation, isomerization, and dissociation) involving the reactive
intermediates cis- and trans-HOCO, which can only be observed transiently.
Using time-resolved frequency comb spectroscopy, comprehensive mechanistic
elucidation of the kinetics of the isotopic analogue deuteroxyl radical (OD)
with CO has been realized. By monitoring the concentrations of reactants,
intermediates, and products in real-time, the branching and isomerization
kinetics and absolute yields of all species in the OD+CO reaction are
quantified as a function of pressure and collision partner.Comment: 19 pages, 4 figure
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