Phonon effect on two coupled quantum dots at finite temperature

The quantum oscillations of population in an asymmetric double quantum dots system coupled to a phonon bath are investigated theoretically. It is shown how the environmental temperature has effect on the system

Effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) on swallowing function of post-stroke individuals with dysphagia : a pilot study

This pilot study investigates the effects of high-frequency 5 Hz repetitive Transcranial Magnetic Stimulation (rTMS) on swallowing functions and quality of life of post-stroke individuals with dysphagia. Two male and two female participants were assigned randomly to active and sham groups. The participants in the active group received ten sessions of active rTMS for two weeks, whereas the sham participants received ten sessions of sham rTMS for two weeks. Outcome measures were taken at baseline, one week and one month post rTMS. The results showed that the active group had higher oropharyngeal efficiency (OPSE) and lower swallowing activity and participation profile (SAPP) total score at one week and one month post-stimulation. The current study suggests that 5 Hz rTMS may help to improve swallowing functions in patients with post-stroke dysphagia.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Non-Fermi Liquid behavior at the Orbital Ordering Quantum Critical Point in the Two-Orbital Model

The critical behavior of a two-orbital model with degenerate $d_{xz}$ and $d_{yz}$ orbitals is investigated by multidimensional bosonization. We find that the corresponding bosonic theory has an overdamped collective mode with dynamical exponent $z=3$, which appears to be a general feature of a two-orbital model and becomes the dominant fluctuation in the vicinity of the orbital-ordering quantum critical point. Since the very existence of this $z=3$ overdamped collective mode induces non-Fermi liquid behavior near the quantum critical point, we conclude that a two-orbital model generally has a sizable area in the phase diagram showing non-Fermi liquid behavior. Furthermore, we show that the bosonic theory resembles the continuous model near the d-wave Pomeranchuk instability, suggesting that orbital order in a two-orbital model is identical to nematic order in a continuous model. Our results can be applied to systems with degenerate $d_{xz}$ and $d_{yz}$ orbitals such as iron-based superconductors and bilayer strontium ruthenates Sr$_3$Ru$_2$O$_7$.Comment: 5 pages, 2 figure

Cross-Layer Design of FDD-OFDM Systems based on ACK/NAK Feedbacks

It is well-known that cross-layer scheduling which adapts power, rate and user allocation can achieve significant gain on system capacity. However, conventional cross-layer designs all require channel state information at the base station (CSIT) which is difficult to obtain in practice. In this paper, we focus on cross-layer resource optimization based on ACK/NAK feedback flows in OFDM systems without explicit CSIT. While the problem can be modeled as Markov Decision Process (MDP), brute force approach by policy iteration or value iteration cannot lead to any viable solution. Thus, we derive a simple closed-form solution for the MDP cross-layer problem, which is asymptotically optimal for sufficiently small target packet error rate (PER). The proposed solution also has low complexity and is suitable for realtime implementation. It is also shown to achieve significant performance gain compared with systems that do not utilize the ACK/NAK feedbacks for cross-layer designs or cross-layer systems that utilize very unreliable CSIT for adaptation with mismatch in CSIT error statistics. Asymptotic analysis is also provided to obtain useful design insights