2,437 research outputs found

    Developing the scales on evaluation beliefs of student teachers

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    The purpose of the study reported in this paper was to investigate the validity and the reliability of a newly developed questionnaire named ‘Teacher Evaluation Beliefs’ (TEB). The framework for developing items was provided by the two models. The first model focuses on Student-Centered and Teacher-Centered beliefs about evaluation while the other centers on five dimensions (what/ who/ when/ why/ how). The validity and reliability of the new instrument was investigated using both exploratory and confirmatory factor analysis study (n=446). Overall results indicate that the two-factor structure is more reasonable than the five-factor one. Further research needs additional items about the latent dimensions “what” ”who” ”when” ”why” “how” for each existing factor based on Student-centered and Teacher-centered approaches

    Rates of DNA Sequence Profiles for Practical Values of Read Lengths

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    A recent study by one of the authors has demonstrated the importance of profile vectors in DNA-based data storage. We provide exact values and lower bounds on the number of profile vectors for finite values of alphabet size qq, read length ℓ\ell, and word length nn.Consequently, we demonstrate that for q≄2q\ge 2 and n≀qℓ/2−1n\le q^{\ell/2-1}, the number of profile vectors is at least qÎșnq^{\kappa n} with Îș\kappa very close to one.In addition to enumeration results, we provide a set of efficient encoding and decoding algorithms for each of two particular families of profile vectors

    Superconducting fluctuations in a thin NbN film probed by the Hall effect

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    We present a comprehensive study of how superconducting fluctuations in the normal state contribute to the conductivity tensor in a thin (119 A˚\AA) film of NbN. It is shown how these fluctuations drive a sign change in the Hall coefficient RHR_\mathrm{H} for low magnetic fields near the superconducting transition. The scaling behaviours as a function of distance to the transition Ï”=ln⁥(T/Tc)\epsilon=\ln(T/T_\mathrm{c}) of the longitudinal (σxx\sigma_\mathrm{xx}) and transverse (σxy\sigma_\mathrm{xy}) conductivity is found to be consistent with Gaussian fluctuation theory. Moreover, excellent quantitative agreement between theory and experiment is obtained without any adjustable parameters. Our experimental results thus provide a case study of the conductivity tensor originating from short-lived Cooper pairs.Comment: 6 pages, 4 figure

    Dispersion relations for stationary light in one-dimensional atomic ensembles

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    We investigate the dispersion relations for light coupled to one-dimensional ensembles of atoms with different level schemes. The unifying feature of all the considered setups is that the forward and backward propagating quantum fields are coupled by the applied classical drives such that the group velocity can vanish in an effect known as "stationary light". We derive the dispersion relations for all the considered schemes, highlighting the important differences between them. Furthermore, we show that additional control of stationary light can be obtained by treating atoms as discrete scatterers and placing them at well defined positions. For the latter purpose, a multi-mode transfer matrix theory for light is developed

    Microscopic neutron investigation of the Abrikosov state of high-temperature superconductors

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    Using small angle neutron scattering we have been able to observe for the first time a well-defined vortex lattice (VL) structure both in the hole-doped LSCO and electron-doped NCCO superconductors. Our measurements on optimally doped LSCO reveal the existence of a magnetic field-induced phase transition from a hexagonal to a square coordination of the VL. Various scenarios to explain such phase transition are presented. In NCCO also a clear square VL could be detected, which is unexpectedly kept down to the lowest measurable magnetic field

    Confronting the Demise of a Mother Tongue: The Feasibility of Implementing Language Immersion Programs to Reinvigorate the Taiwanese Language

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    In Taiwan, where Mandarin is the official language, the survival of Taiwanese, the mother tongue of sixty percent of the island’s inhabitants, is threatened. In this article, the authors discuss data from previous and ongoing research on the role of language and the significance of language loss in the quest for a “Taiwanese identity.” Research shows that the dominance of Mandarin over Taiwanese plus the growing support for English in Taiwan are likely indications that current Mandarin/Taiwanese bilingualism is being replaced by Mandarin/English bilingualism. Canadian, Finnish, Basque and Catalonian models of language immersion programs will be proposed as an alternative to Taiwan’s current language policy. The authors argue that such models, when applied to a significant degree in Taiwan’s primary education system, will contribute to strengthening Taiwanese identity, to defending the right of youngsters to receive their education in their Taiwanese mother tongue, and to creating more effective English language training.Le mandarin, langue officielle de Taiwan, menace la survie du taiwanais, qui est la langue maternelle de soixante pour cent de la population de l’üle. Dans le prĂ©sent article, les auteurs discutent des rĂ©sultats de leurs recherches prĂ©cĂ©dentes et en cours et montrent la signifiance de la perte de la langue maternelle pour l’identitĂ© taiwanaise. Ils montrent Ă©galement que la suprĂ©matie du mandarin sur le taiwanais et l’appui croissant en faveur de l’anglais Ă  Taiwan laissent prĂ©voir l’implantation d’un bilinguisme mandarin/anglais au dĂ©triment du bilinguisme mandarin/taiwanais. Les auteurs considĂšrent que les modĂšles d’enseignement bilingue immersif mis en place au Canada, en Finlande, dans le pays Basque et en Catalogne, s’ils Ă©taient mis en oeuvre de façon gĂ©nĂ©ralisĂ©e Ă  Taiwan, pourraient contribuer Ă  renforcer l’identitĂ© taiwanaise, Ă  dĂ©fendre le droit des jeunes Ă  une Ă©ducation dans leur langue maternelle et Ă  favoriser l’enseignement plus efficace de l’anglais

    Refinements of the Ziegler-Nichols Tuning Formula for PID Auto-Tuners

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    An approach to compositional reasoning about concurrent objects and futures

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    Distributed and concurrent object-oriented systems are difficult to analyze due to the complexity of their concurrency, communication, and synchronization mechanisms. Rather than performing analysis at the code level of mainstream objectoriented languages such as Java and C++, we consider an imperative, objectoriented language with a simpler concurrency model. This language, based on concurrent objects communicating by asynchronous method calls and futures, avoids some difficulties of mainstream object-oriented programming languages related to compositionality and aliasing. In particular, reasoning about futures is handled by means of histories. Compositional verification systems facilitate system analysis, allowing components to be analyzed independently of their environment. In this paper, a compositional proof system in dynamic logic for partial correctness is established based on communication histories and class invariants. The soundness and relative completeness of this proof system follow by construction using a transformational approach from a sequential language with a non-deterministic assignment operator
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