EFFECTS OF WHOLE BODY VIBRATION TRAINING ON KNEE EXTENSOR MUSCLE STRENGTH AND RATE OF FORCE DEVELOPMENT

This study compared the effects of 8-week whole-body vibration (WBV) training programs on knee extensor muscle strength and rate of force development. Twenty physically active male subjects were randomly assigned to a whole-body vibration training group (WBV; n =10) or a sham training group (SHAM; n = 10). Maximal voluntary isometric joint moment, rate of force development (RFD) and contractile impulse of the knee extensors were assessed before and after the training period. There were significant differences between WBV and sham groups on improvement percentage of maximum joint moment, RFD and contractile impulse in knee extensor. We concluded that not only knee extensor muscle strength could be enhanced but also muscle contractile abilty could be faster after a 8-week WBV training program

Impact of the Casimir-Polder Potential and Johnson Noise on Bose-Einstein Condensate Stability near Surfaces

We investigate the stability of magnetically trapped atomic Bose-Einstein condensates and thermal clouds near the transition temperature at small distances 0.5 microns < d < 10 microns from a microfabricated silicon chip. For a 2 microns thick copper film the trap lifetime is limited by Johnson-noise induced currents and falls below 1 s at a distance of 4 microns. A dielectric surface does not adversely affect the sample until the attractive Casimir-Polder potential significantly reduces the trap depth.Comment: 4 pages, 5 figures, and submitted to Physical Review Letter

The Relationships between Peer- and Self-Assessment and Teacher Assessment of Young EFL Learners’ Oral Presentations

A uncorrected proof of the manuscript is released here according to Springer author agreement.As the traditional grammar translation approach is being gradually replaced by communicative or task-based approaches, paper-and-pencil tests, commonly used in English classes in Taiwan, do not meet the course goals. Alternative assessment, known for increasing learners’ cognitive and meta-cognitive development as well as empowering students to take ownership of their learning, has been practiced extensively in L1 higher education, but neglected in L2 elementary schools. Thus, the purpose of this study is to investigate how peer and self-assessment can be implemented to evaluate young EFL learners’ oral presentation and how the students perceive this experience. The study was conducted in two sixth grade classes at a public elementary school in southern Taiwan. After attending a professional development workshop held by the government, a local English teacher practiced peer and self-assessment in her class so as to engage every student in class activities and also to provide an opportunity for them to reflect upon their performance. In the process, the students formed groups of six to discuss and give grades after each individual student’s oral report. Three types of data sources were analyzed. The first was the evaluation rubrics from peer groups, each presenting students, and the teacher. Then, a survey, containing 16 closed-format questions and one open-ended question, was administered to elicit the students’ perceptions of the assessment process. Also, an interview was done with the teacher. The results show that peer and teacher assessment had strong positive correlation, whereas self- and teacher assessment were moderately correlated. The strength of correlation also varied for each evaluation criterion. Though learners responded positively to the assessing experiences in the questionnaires, they expressed concern that some grades assigned by peers were not fair and a few group members dominated the grading process. The findings shed light on benefits of combining peer and self- assessment and suggest training should emphasize self-assessment, evaluation criteria related to content of the presentation, and students’ social skills to work harmoniously in groups. Most of all, students’ traditional way of learning should not be neglected

N-(1-Acetyl-5-benzoyl-1,4,5,6-tetra­hydro­pyrrolo­[3,4-c]pyrazol-3-yl)benzamide

In the mol­ecule of the title compound, C21H18N4O3, the fused pyrrolo­[3,4-c]pyrazole ring system is approximately planar [maximum deviation = 0.0486 (16) Å] and forms dihedral angles of 87.21 (8) and 35.46 (7)° with the phenyl rings. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds and weak C—H⋯π inter­actions link the mol­ecules into chains parallel to [201]

Speech Enhancement Guided by Contextual Articulatory Information

Previous studies have confirmed the effectiveness of leveraging articulatory information to attain improved speech enhancement (SE) performance. By augmenting the original acoustic features with the place/manner of articulatory features, the SE process can be guided to consider the articulatory properties of the input speech when performing enhancement. Hence, we believe that the contextual information of articulatory attributes should include useful information and can further benefit SE in different languages. In this study, we propose an SE system that improves its performance through optimizing the contextual articulatory information in enhanced speech for both English and Mandarin. We optimize the contextual articulatory information through joint-train the SE model with an end-to-end automatic speech recognition (E2E ASR) model, predicting the sequence of broad phone classes (BPC) instead of the word sequences. Meanwhile, two training strategies are developed to train the SE system based on the BPC-based ASR: multitask-learning and deep-feature training strategies. Experimental results on the TIMIT and TMHINT dataset confirm that the contextual articulatory information facilitates an SE system in achieving better results than the traditional Acoustic Model(AM). Moreover, in contrast to another SE system that is trained with monophonic ASR, the BPC-based ASR (providing contextual articulatory information) can improve the SE performance more effectively under different signal-to-noise ratios(SNR).Comment: Will be submitted to TASL

Magnon-induced non-Markovian friction of a domain wall in a ferromagnet

Motivated by the recent study on the quasiparticle-induced friction of solitons in superfluids, we theoretically study magnon-induced intrinsic friction of a domain wall in a one-dimensional ferromagnet. To this end, we start by obtaining the hitherto overlooked dissipative interaction of a domain wall and its quantum magnon bath to linear order in the domain-wall velocity and to quadratic order in magnon fields. An exact expression for the pertinent scattering matrix is obtained with the aid of supersymmetric quantum mechanics. We then derive the magnon-induced frictional force on a domain wall in two different frameworks: time-dependent perturbation theory in quantum mechanics and the Keldysh formalism, which yield identical results. The latter, in particular, allows us to verify the fluctuation-dissipation theorem explicitly by providing both the frictional force and the correlator of the associated stochastic Langevin force. The potential for magnons induced by a domain wall is reflectionless, and thus the resultant frictional force is non-Markovian similarly to the case of solitons in superfluids. They share an intriguing connection to the Abraham-Lorentz force that is well-known for its causality paradox. The dynamical responses of a domain wall are studied under a few simple circumstances, where the non-Markovian nature of the frictional force can be probed experimentally. Our work, in conjunction with the previous study on solitons in superfluids, shows that the macroscopic frictional force on solitons can serve as an effective probe of the microscopic degrees of freedom of the system.Comment: 13 pages, 2 figure