714 research outputs found
Universal Continuous Variable Quantum Computation in the Micromaser
We present universal continuous variable quantum computation (CVQC) in the
micromaser. With a brief history as motivation we present the background theory
and define universal CVQC. We then show how to generate a set of operations in
the micromaser which can be used to achieve universal CVQC. It then follows
that the micromaser is a potential architecture for CVQC but our proof is
easily adaptable to other potential physical systems.Comment: 12 pages, 4 figures, accepted for a presentation at the 9th
International Conference on Unconventional Computation (UC10) and LNCS
proceedings
Worm Epidemics in Wireless Adhoc Networks
A dramatic increase in the number of computing devices with wireless
communication capability has resulted in the emergence of a new class of
computer worms which specifically target such devices. The most striking
feature of these worms is that they do not require Internet connectivity for
their propagation but can spread directly from device to device using a
short-range radio communication technology, such as WiFi or Bluetooth. In this
paper, we develop a new model for epidemic spreading of these worms and
investigate their spreading in wireless ad hoc networks via extensive Monte
Carlo simulations. Our studies show that the threshold behaviour and dynamics
of worm epidemics in these networks are greatly affected by a combination of
spatial and temporal correlations which characterize these networks, and are
significantly different from the previously studied epidemics in the Internet
The Bell Theorem as a Special Case of a Theorem of Bass
The theorem of Bell states that certain results of quantum mechanics violate
inequalities that are valid for objective local random variables. We show that
the inequalities of Bell are special cases of theorems found ten years earlier
by Bass and stated in full generality by Vorob'ev. This fact implies precise
necessary and sufficient mathematical conditions for the validity of the Bell
inequalities. We show that these precise conditions differ significantly from
the definition of objective local variable spaces and as an application that
the Bell inequalities may be violated even for objective local random
variables.Comment: 15 pages, 2 figure
Does training with amplitude modulated tones affect tone-vocoded speech perception?
Temporal-envelope cues are essential for successful speech perception. We asked here whether training on stimuli containing temporal-envelope cues without speech content can improve the perception of spectrally-degraded (vocoded) speech in which the temporal-envelope (but not the temporal fine structure) is mainly preserved. Two groups of listeners were trained on different amplitude-modulation (AM) based tasks, either AM detection or AM-rate discrimination (21 blocks of 60 trials during two days, 1260 trials; frequency range: 4Hz, 8Hz, and 16Hz), while an additional control group did not undertake any training. Consonant identification in vocoded vowel-consonant-vowel stimuli was tested before and after training on the AM tasks (or at an equivalent time interval for the control group). Following training, only the trained groups showed a significant improvement in the perception of vocoded speech, but the improvement did not significantly differ from that observed for controls. Thus, we do not find convincing evidence that this amount of training with temporal-envelope cues without speech content provide significant benefit for vocoded speech intelligibility. Alternative training regimens using vocoded speech along the linguistic hierarchy should be explored
Tuning of Human Modulation Filters Is Carrier-Frequency Dependent
Licensed under the Creative Commons Attribution License
The general purpose analog computer and computable analysis are two equivalent paradigms of analog computation
In this paper we revisit one of the rst models of analog
computation, Shannon's General Purpose Analog Computer (GPAC).
The GPAC has often been argued to be weaker than computable analysis.
As main contribution, we show that if we change the notion of GPACcomputability
in a natural way, we compute exactly all real computable
functions (in the sense of computable analysis). Moreover, since GPACs
are equivalent to systems of polynomial di erential equations then we
show that all real computable functions can be de ned by such models
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
The Sound Sensation of Apical Electric Stimulation in Cochlear Implant Recipients with Contralateral Residual Hearing
BACKGROUND: Studies using vocoders as acoustic simulators of cochlear implants have generally focused on simulation of speech understanding, gender recognition, or music appreciation. The aim of the present experiment was to study the auditory sensation perceived by cochlear implant (CI) recipients with steady electrical stimulation on the most-apical electrode. METHODOLOGY/PRINCIPAL FINDINGS: Five unilateral CI users with contralateral residual hearing were asked to vary the parameters of an acoustic signal played to the non-implanted ear, in order to match its sensation to that of the electric stimulus. They also provided a rating of similarity between each acoustic sound they selected and the electric stimulus. On average across subjects, the sound rated as most similar was a complex signal with a concentration of energy around 523 Hz. This sound was inharmonic in 3 out of 5 subjects with a moderate, progressive increase in the spacing between the frequency components. CONCLUSIONS/SIGNIFICANCE: For these subjects, the sound sensation created by steady electric stimulation on the most-apical electrode was neither a white noise nor a pure tone, but a complex signal with a progressive increase in the spacing between the frequency components in 3 out of 5 subjects. Knowing whether the inharmonic nature of the sound was related to the fact that the non-implanted ear was impaired has to be explored in single-sided deafened patients with a contralateral CI. These results may be used in the future to better understand peripheral and central auditory processing in relation to cochlear implants
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Inland Pacific Northwest pasture calendar
The Inland Pacific Northwest (PNW) region, historically referred to as the 'Inland Empire', extends from the Cascade Mountains in the west to former Glacial Lake Missoula in the Rockies in the east and from the Canadian border in the north past the Snake River Canyon in the south. The greatest agricultural enterprises are hay (from various forage species), irrigated and non-irrigated grassland pastures, rangelands, and livestock production. It is also home to numerous wildlife species and flyways for migrating birds. The Inland PNW Pasture Calendar is designed to be a comprehensive guide for improved grassland management in support of forage-livestock systems. Applying the principles described will lead to improved regional economic, ecological, and social sustainability. This publication describes the opportunities and challenges of sustainably raising harvested and grazed forages and developing forage-livestock systems in this incredibly diverse environment. Appendix Chapters provide key information on grass / legume / forb species, how pasture species grow and regrow, soil nutrient management and organic matter, grazing philosophies and systems, matching grazing needs for pasture production, and forage-related animal health issues. Learning these key principles and following best management practices described will lead to improved sustainability of forage-livestock systems
Second law, entropy production, and reversibility in thermodynamics of information
We present a pedagogical review of the fundamental concepts in thermodynamics
of information, by focusing on the second law of thermodynamics and the entropy
production. Especially, we discuss the relationship among thermodynamic
reversibility, logical reversibility, and heat emission in the context of the
Landauer principle and clarify that these three concepts are fundamentally
distinct to each other. We also discuss thermodynamics of measurement and
feedback control by Maxwell's demon. We clarify that the demon and the second
law are indeed consistent in the measurement and the feedback processes
individually, by including the mutual information to the entropy production.Comment: 43 pages, 10 figures. As a chapter of: G. Snider et al. (eds.),
"Energy Limits in Computation: A Review of Landauer's Principle, Theory and
Experiments
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