2,223 research outputs found
Effective thermodynamics of strongly coupled qubits
Interactions between a quantum system and its environment at low temperatures
can lead to violations of thermal laws for the system. The source of these
violations is the entanglement between system and environment, which prevents
the system from entering into a thermal state. On the other hand, for two-state
systems, we show that one can define an effective temperature, placing the
system into a `pseudo-thermal' state where effective thermal laws are upheld.
We then numerically explore these assertions for an n-state system inspired by
the spin-boson environment.Comment: 9 pages, 3 figure
Neural Attentive Session-based Recommendation
Given e-commerce scenarios that user profiles are invisible, session-based
recommendation is proposed to generate recommendation results from short
sessions. Previous work only considers the user's sequential behavior in the
current session, whereas the user's main purpose in the current session is not
emphasized. In this paper, we propose a novel neural networks framework, i.e.,
Neural Attentive Recommendation Machine (NARM), to tackle this problem.
Specifically, we explore a hybrid encoder with an attention mechanism to model
the user's sequential behavior and capture the user's main purpose in the
current session, which are combined as a unified session representation later.
We then compute the recommendation scores for each candidate item with a
bi-linear matching scheme based on this unified session representation. We
train NARM by jointly learning the item and session representations as well as
their matchings. We carried out extensive experiments on two benchmark
datasets. Our experimental results show that NARM outperforms state-of-the-art
baselines on both datasets. Furthermore, we also find that NARM achieves a
significant improvement on long sessions, which demonstrates its advantages in
modeling the user's sequential behavior and main purpose simultaneously.Comment: Proceedings of the 2017 ACM on Conference on Information and
Knowledge Management. arXiv admin note: text overlap with arXiv:1511.06939,
arXiv:1606.08117 by other author
Genome sequences of 12 bacterial isolates obtained from the urine of pregnant women
The presence of bacteria in urine can pose significant risks during pregnancy. However, there are few reference genome strains for many common urinary bacteria. We isolated 12 urinary strains of Streptococcus, Staphylococcus, Citrobacter, Gardnerella, and Lactobacillus. These strains and their genomes are now available to the research community
Measuring the proton selectivity of graphene membranes
By systematically studying the proton selectivity of free-standing graphene
membranes in aqueous solutions we demonstrate that protons are transported by
passing through defects. We study the current-voltage characteristics of
single-layer graphene grown by chemical vapour deposition (CVD) when a
concentration gradient of HCl exists across it. Our measurements can
unambiguously determine that H+ ions are responsible for the selective part of
the ionic current. By comparing the observed reversal potentials with positive
and negative controls we demonstrate that the as-grown graphene is only weakly
selective for protons. We use atomic layer deposition to block most of the
defects in our CVD graphene. Our results show that a reduction in defect size
decreases the ionic current but increases proton selectivity.This is the author accepted manuscript. The final version is available from AIP via http://dx.doi.org/10.1063/1.493633
Mutual information between geomagnetic indices and the solar wind as seen by WIND : implications for propagation time estimates
The determination of delay times of solar wind conditions at the sunward libration point to effects on Earth is investigated using mutual information. This measures the amount of information shared between two timeseries. We consider the mutual information content of solar wind observations, from WIND, and the geomagnetic indices. The success of five commonly used schemes for estimating interplanetary propagation times is examined. Propagation assuming a fixed plane normal at 45 degrees to the GSE x-axis (i.e. the Parker Spiral estimate) is found to give optimal mutual information. The mutual information depends on the point in space chosen as the target for the propagation estimate, and we find that it is maximized by choosing a point in the nightside rather than dayside magnetosphere. In addition, we employ recurrence plot analysis to visualize contributions to the mutual information, this suggests that it appears on timescales of hours rather than minutes
Genome sequences of 11 human vaginal Actinobacteria strains
The composition of the vaginal microbiota is an important health determinant. Several members of the phylum Actinobacteria have been implicated in bacterial vaginosis, a condition associated with many negative health outcomes. Here, we present 11 strains of vaginal Actinobacteria (now available through BEI Resources) along with draft genome sequences
Optical air data systems and methods
Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip
Optical air data systems and methods
Systems and methods for sensing air outside a moving aircraft are presented. In one embodiment, a system includes a laser for generating laser energy. The system also includes one or more transceivers for projecting the laser energy as laser radiation to the air. Subsequently, each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines one or more air parameters based on the scattered laser radiation. Such air parameters may include air speed, air pressure, air temperature and aircraft orientation angle, such as yaw, angle of attack and sideslip
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