12,173 research outputs found
Language Learning Motivation and Language Learning Strategies of Taiwanese EFL Students
[[abstract]]This study investigated the relationship between student motivation, both extrinsic and intrinsic, and learning strategies for English as a foreign language (EFL) students. Subjects were 46 Taiwanese undergraduate and graduate students of advanced EFL at a public university in the United States who were administered motivation and learning strategies questionnaires. Results reveal that total learning strategies were associated with motivational intensity, intrinsic motivation, and extrinsic motivation. Intrinsic motivation was associated with cognitive and metacognitive learning strategies, while extrinsic motivation was associated with memory and affective strategies. Compensation strategies were the most commonly used, and had little relationship to motivation. Social strategies had little relationship to either extrinsic or intrinsic motivation. Motivational intensity correlated moderately with intrinsic motivation, but had little relationship to extrinsic motivation. An appendix contains the survey questionnaire. Contains 42 references
Describing a Quantum Channel by State Tomography of a Single Probe State
A general law is presented for (composite) quantum systems which directly
describes the time evolution of quantum states (with one or both components)
through an arbitrary noisy quantum channel. It is shown that the time evolution
of all quantum states through a quantum channel can be completely captured by
the evolution of a single 'probe state'. Thus in order to grasp the information
of the final output states subject to a quantum channel, especially an unknown
one, it only requires quantum state tomography of a single probe state, which
dramatically simplifies the practical operations in experiment.Comment: 3 pages, To be publised in EP
Measurable Concurrence of Mixed States
We show that bipartite concurrence for rank-2 mixed states of qubits is
written by an observable which can be exactly and directly measurable in
experiment by local projective measurements, provided that four copies of the
composite quantum system are available. In addition, for a tripartite quantum
pure state of qubits, the 3-tangle is also shown to be measurable only by
projective measurements on the reduced density matrices of a pair of qubits
conditioned on four copies of the state.Comment: 3 page
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