14,238 research outputs found
Finite Element Solution of Axisymmetrical Dynamic Problems of Shells of Revolution
Finite element solution for natural frequencies and mode shapes of free axisymmetrical vibrations and dynamic response of arbitrary rotationally symmetric shell
Energy-efficiency improvements for optical access
This article discusses novel approaches to improve energy efficiency of different optical access technologies, including time division multiplexing passive optical network (TDM-PON), time and wavelength division multiplexing PON (TWDM-PON), point-to-point (PTP) access network, wavelength division multiplexing PON (WDM-PON), and orthogonal frequency division multiple access PON (OFDMA-PON). These approaches include cyclic sleep mode, energy-efficient bit interleaving protocol, power reduction at component level, or frequency band selection. Depending on the target optical access technology, one or a combination of different approaches can be applied
Relaxation properties of the quantum kinetics of carrier-LO-phonon interaction in quantum wells and quantum dots
The time evolution of optically excited carriers in semiconductor quantum
wells and quantum dots is analyzed for their interaction with LO-phonons. Both
the full two-time Green's function formalism and the one-time approximation
provided by the generalized Kadanoff-Baym ansatz are considered, in order to
compare their description of relaxation processes. It is shown that the
two-time quantum kinetics leads to thermalization in all the examined cases,
which is not the case for the one-time approach in the intermediate-coupling
regime, even though it provides convergence to a steady state. The
thermalization criterion used is the Kubo-Martin-Schwinger condition.Comment: 7 pages, 8 figures, accepted for publication in Phys. Rev.
Academic Dishonesty in the Canadian Classroom: Behaviours of a Sample of University Students
Academic dishonesty is a persistent problem in institutions of higher education, with numerous short- and long-term implications. This study examines undergraduate students’ self-reported engagement in acts of academic dishonesty using data from a sample of 321 participants attending a public university in a western Canadian city during the fall of 2007. Various factors were assessed for their influence on students’ extent of academic dishonesty. More than one-half of respondents engaged in at least one of three types of dishonest behaviours surveyed during their tenure in university. Faculty of enrolment, strategies for learning, perceptions of peers’ cheating and their requests for help, and perceptions and evaluations of academic dishonesty made unique contributions to the prediction of academic dishonesty. High self-efficacy acted as a protective factor that interacted with instrumental motives to study to reduce students’ propensity to engage in dishonest academic behaviours. Implications of these findings for institutional interventions are briefly discussed.
Le comportement académique malhonnête persiste dans les institutions d’enseignement supérieur, et ses implications à court et à long terme sont nombreuses. La présente étude examine l’adoption d’un comportement académique malhonnête par des étudiants de premier cycle, grâce aux données d’un échantillon de 321 participants qui fréquentaient une université publique dans une ville de l’ouest canadien à l’automne 2007. Différents facteurs ont été évalués en fonction de leur influence sur l’étendue du comportement académique malhonnête des étudiants. Plus de la moitié des étudiants échantillonnés ont adopté au moins l’un des trois types de comportements malhonnêtes au cours de leur passage à l’université. La faculté à s’inscrire, les stratégies d’apprentissage, la perception quant au comportement tricheur des pairs et quant à leurs demandes d’aide, et les perceptions et évaluations de la malhonnêteté académique constituent des indices uniques pour ce qui est de prédire le comportement académique malhonnête. Un degré élevé d’auto-efficacité, de même que certains motifs essentiels, avaient un effet protecteur dans la réduction de la propension des étudiants à s’engager dans des comportements académiques malhonnêtes. L’article aborde brièvement les conséquences de ces résultats au cours d’interventions en institution d’enseignement.
 
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