202 research outputs found
Entanglement-assisted quantum metrology
Entanglement-assisted quantum communication employs pre-shared entanglement
between sender and receiver as a resource. We apply the same framework to
quantum metrology, introducing shared entanglement between the preparation and
the measurement stage, namely using some entangled ancillary system that does
not interact with the system to be sampled. This is known to be useless in the
noiseless case, but was recently shown to be useful in the presence of noise.
Here we detail how and when it can be of use. For example, surprisingly it is
useful when randomly time sharing two channels where ancillas do not help
(depolarizing). We show that it is useful for all levels of noise for many
noise models and propose a simple experiment to test these results.Comment: 5 pages, 5 figure
Error reduction for quantum sensing via interferometry
Dephasing is a main noise mechanism that afflicts quantum information, it
reduces visibility, and destroys coherence and entanglement. Therefore, it must
be reduced, mitigated, and if possible corrected, to allow for the
demonstration of quantum advantage in any application of quantum technology,
from computing to sensing and communications. Here we discuss a hardware scheme
of error filtration to mitigate the effects of dephasing in optical quantum
metrology. The scheme uses only passive linear optics and ancillary vacuum
modes, and we do not need single-photon sources or entanglement. It exploits
constructive and destructive interference to partially cancel the detrimental
effects of statistically independent sources of dephasing. We apply this scheme
to preserve coherent states and to phase stabilize stellar interferometry, and
show that a significant improvement can be obtained by using only a few
ancillary modes.Comment: 12 pages, 4 figures, comments are welcom
Hyperbolic Interaction Model For Hierarchical Multi-Label Classification
Different from the traditional classification tasks which assume mutual
exclusion of labels, hierarchical multi-label classification (HMLC) aims to
assign multiple labels to every instance with the labels organized under
hierarchical relations. Besides the labels, since linguistic ontologies are
intrinsic hierarchies, the conceptual relations between words can also form
hierarchical structures. Thus it can be a challenge to learn mappings from word
hierarchies to label hierarchies. We propose to model the word and label
hierarchies by embedding them jointly in the hyperbolic space. The main reason
is that the tree-likeness of the hyperbolic space matches the complexity of
symbolic data with hierarchical structures. A new Hyperbolic Interaction Model
(HyperIM) is designed to learn the label-aware document representations and
make predictions for HMLC. Extensive experiments are conducted on three
benchmark datasets. The results have demonstrated that the new model can
realistically capture the complex data structures and further improve the
performance for HMLC comparing with the state-of-the-art methods. To facilitate
future research, our code is publicly available
Substrate entering and product leaving trajectories predict an engulfing dynamic for the major conformational change of the β-lactam acylase
It is still a major challenge to acquire insight into the conformational changes between the ground state and the transition state of an enzyme, although conformational fluctuation within interconverting conformers has been widely investigated (1-4). Here, we utilize different enzymatic reactions in b-lactam acylase to figure out the substrate/product trajectories in the enzyme, thereby probing the overall conformational changes in transition state. First, an auto-proteolytic intermediate of cephalosporin acylase (EC 3.5.1.11) with partial spacer segment was identified. As a final proteolytic step, the deletion of this spacer segment was revealed to be a first-order reaction, suggesting an intramolecular Ntn mechanism for the auto-proteolysis. Accordingly, the different proteolytic sites in the acylase precursor indicate a substrate entering pathway along the spacer peptide. Second, bromoacyl-7ACA can interact with penicillin G acylase (EC 3.5.1.11) in two distinguish aspects, to be hydrolyzed as a substrate analogue and to affinity alkylate the conserved Trpb4 as a product analogue. The kinetic correlation between these two reactions suggests a channel opening from Serb1 to Trpb4, responsible for the main product leaving. These two reaction trajectories relaying at the active centre, together with the crystal structures (5-10), predict an engulfing dynamic involving pocket constriction and channel opening
Community With Shared Differences: Solo Performance in Pat Kinevane’s Silent and Panti’s A Woman in Progress
Solo performance is a theatrical form which has been increasingly popular in contemporary Irish theatre with the rise of individualism. This paper takes the works of two representative solo performers in contemporary Irish theatre, Pat Kinevane and Panti (Rory O’Neill) as examples, trying to discuss how the form of solo performance is applied by the two performers to create an intermediate space for the marginalized groups to find their distinctive voices and for the audience to identify with the “other”, so as to build up a community that respects differences. While at the same time, the two performers use postdramatic strategies to admonish the audience to take a step back to reexamine the constructiveness of community and performativity of identity. By addressing the significance of solo performance in contemporary Irish theatre, this paper calls for the diversification of not only subjects but also forms in contemporary Irish theatre
Non-uniqueness of critical solid fraction considering boundary conditions and strain-rate effects
Experimental Perfect Quantum State Transfer
The transfer of data is a fundamental task in information systems.
Microprocessors contain dedicated data buses that transmit bits across
different locations and implement sophisticated routing protocols. Transferring
quantum information with high fidelity is a challenging task, due to the
intrinsic fragility of quantum states. We report on the implementation of the
perfect state transfer protocol applied to a photonic qubit entangled with
another qubit at a different location. On a single device we perform three
routing procedures on entangled states with an average fidelity of 97.1%. Our
protocol extends the regular perfect state transfer by maintaining quantum
information encoded in the polarisation state of the photonic qubit. Our
results demonstrate the key principle of perfect state transfer, opening a
route toward data transfer for quantum computing systems
DEM analysis of the onset of flow deformation of sands: linking monotonic and cyclic undrained behaviours
Discovering Domain Disentanglement for Generalized Multi-source Domain Adaptation
A typical multi-source domain adaptation (MSDA) approach aims to transfer
knowledge learned from a set of labeled source domains, to an unlabeled target
domain. Nevertheless, prior works strictly assume that each source domain
shares the identical group of classes with the target domain, which could
hardly be guaranteed as the target label space is not observable. In this
paper, we consider a more versatile setting of MSDA, namely Generalized
Multi-source Domain Adaptation, wherein the source domains are partially
overlapped, and the target domain is allowed to contain novel categories that
are not presented in any source domains. This new setting is more elusive than
any existing domain adaptation protocols due to the coexistence of the domain
and category shifts across the source and target domains. To address this
issue, we propose a variational domain disentanglement (VDD) framework, which
decomposes the domain representations and semantic features for each instance
by encouraging dimension-wise independence. To identify the target samples of
unknown classes, we leverage online pseudo labeling, which assigns the
pseudo-labels to unlabeled target data based on the confidence scores.
Quantitative and qualitative experiments conducted on two benchmark datasets
demonstrate the validity of the proposed framework
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