94 research outputs found
Observation of Log-Periodic Oscillations in the Quantum Dynamics of Electrons on the One-Dimensional Fibonacci Quasicrystal
We revisit the question of quantum dynamics of electrons on the off-diagonal
Fibonacci tight-binding model. We find that typical dynamical quantities, such
as the probability of an electron to remain in its original position as a
function of time, display log-periodic oscillations on top of the leading-order
power-law decay. These periodic oscillations with the logarithm of time are
similar to the oscillations that are known to exist with the logarithm of
temperature in the specific heat of Fibonacci electrons, yet they offer new
possibilities for the experimental observation of this unique phenomenon
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Combining Localization Cues and Source Model Constraints for Binaural Source Separation
We describe a system for separating multiple sources from a two-channel recording based on interaural cues and prior knowledge of the statistics of the underlying source signals. The proposed algorithm effectively combines information derived from low level perceptual cues, similar to those used by the human auditory system, with higher level information related to speaker identity. We combine a probabilistic model of the observed interaural level and phase differences with a prior model of the source statistics and derive an EM algorithm for finding the maximum likelihood parameters of the joint model. The system is able to separate more sound sources than there are observed channels in the presence of reverberation. In simulated mixtures of speech from two and three speakers the proposed algorithm gives a signal-to-noise ratio improvement of 1.7 dB over a baseline algorithm which uses only interaural cues. Further improvement is obtained by incorporating eigenvoice speaker adaptation to enable the source model to better match the sources present in the signal. This improves performance over the baseline by 2.7 dB when the speakers used for training and testing are matched. However, the improvement is minimal when the test data is very different from that used in training
Source Separation Based on Binaural Cues and Source Model Constraints
We describe a system for separating multiple sources from a two-channel recording based on interaural cues and known characteristics of the source signals. We combine a probabilistic model of the observed interaural level and phase differences with a prior model of the source statistics and derive an EM algorithm for finding the maximum likelihood parameters of the joint model. The system is able to separate more sound sources than there are observed channels. In simulated reverberant mixtures of three speakers the proposed algorithm gives a signal-to-noise ratio improvement of 2.1 dB over a baseline algorithm using only interaural cues
A computational approach for genome-wide mapping of splicing factor binding sites
A computational method is presented for genome-wide mapping of splicing factor binding sites that considers both the genomic environment and evolutionary conservation
Medical Student Attitudes toward Complementary, Alternative and Integrative Medicine
While the use of complementary, alternative and integrative medicine (CAIM) is substantial, it continues to exist at the periphery of allopathic medicine. Understanding the attitudes of medical students toward CAIM will be useful in understanding future integration of CAIM and allopathic medicine. This study was conducted to develop and evaluate an instrument and assess medical students' attitudes toward CAIM. The Complementary, Alternative and Integrative Medicine Attitudes Questionnaire (CAIMAQ) was developed by a panel of experts in CAIM, allopathic medicine, medical education and survey development. A total of 1770 CAIMAQ surveys (51% of US medical schools participated) were obtained in a national sample of medical students in 2007. Factor analysis of the CAIMAQ revealed five distinct attitudinal domains: desirability of CAIM therapies, progressive patient/physician health care roles, mind-body-spirit connection, principles of allostasis and a holistic understanding of disease. The students held the most positive attitude for the “mind-body-spirit connection” and the least positive for the “desirability of CAIM therapies”. This study provided initial support for the reliability of the CAIMAQ. The survey results indicated that in general students responded more positively to the principles of CAIM than to CAIM treatment. A higher quality of CAIM-related medical education and expanded research into CAIM therapies would facilitate appropriate integration of CAIM into medical curricula. The most significant limitation of this study is a low response rate, and further work is required to assess more representative populations in order to determine whether the relationships found in this study are generalizable
Security governance and the private military industry in Europe and North America
Even before Iraq the growing use of private military contractors has been widely discussed in the
academic and public literature. However, the reasons for this proliferation of private military
companies and its implications are frequently generalized due to a lack of suitable theoretical
approaches for the analysis of private means of violence in contemporary security. As a consequence,
this article contends, the analysis of the growth of the private military industry typically conflates two
separate developments: the failure of some developing states to provide for their national security and
the privatisation of military services in industrialized nations in Europe and North America. This
article focuses on the latter and argues that the concept of security governance can be used as a
theoretical framework for understanding the distinct development, problems and solutions for the
governance of the private military industry in developed countries.The United States Institute of Peace and the German Academic Exchange Service
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