67 research outputs found
Task-Oriented Conversation Generation Using Heterogeneous Memory Networks
How to incorporate external knowledge into a neural dialogue model is
critically important for dialogue systems to behave like real humans. To handle
this problem, memory networks are usually a great choice and a promising way.
However, existing memory networks do not perform well when leveraging
heterogeneous information from different sources. In this paper, we propose a
novel and versatile external memory networks called Heterogeneous Memory
Networks (HMNs), to simultaneously utilize user utterances, dialogue history
and background knowledge tuples. In our method, historical sequential dialogues
are encoded and stored into the context-aware memory enhanced by gating
mechanism while grounding knowledge tuples are encoded and stored into the
context-free memory. During decoding, the decoder augmented with HMNs
recurrently selects each word in one response utterance from these two memories
and a general vocabulary. Experimental results on multiple real-world datasets
show that HMNs significantly outperform the state-of-the-art data-driven
task-oriented dialogue models in most domains.Comment: Accepted as a long paper at EMNLP-IJCNLP 201
MTSS: Learn from Multiple Domain Teachers and Become a Multi-domain Dialogue Expert
How to build a high-quality multi-domain dialogue system is a challenging
work due to its complicated and entangled dialogue state space among each
domain, which seriously limits the quality of dialogue policy, and further
affects the generated response. In this paper, we propose a novel method to
acquire a satisfying policy and subtly circumvent the knotty dialogue state
representation problem in the multi-domain setting. Inspired by real school
teaching scenarios, our method is composed of multiple domain-specific teachers
and a universal student. Each individual teacher only focuses on one specific
domain and learns its corresponding domain knowledge and dialogue policy based
on a precisely extracted single domain dialogue state representation. Then,
these domain-specific teachers impart their domain knowledge and policies to a
universal student model and collectively make this student model a multi-domain
dialogue expert. Experiment results show that our method reaches competitive
results with SOTAs in both multi-domain and single domain setting.Comment: AAAI 2020, Spotlight Pape
Retrospective analysis of 217 fatal intoxication autopsy cases from 2009 to 2021: temporal trends in fatal intoxication at Tongji center for medicolegal expertise, Hubei, China
This retrospective analysis of fatal intoxication case autopsies was performed at Tongji Center for Medicolegal Expertise in Hubei (TCMEH) from 2009 to 2021 to obtain up-to-date information on intoxication cases. The objective was to describe important data about evolving patterns in intoxication occurrences, enhance public safety policies, and assist forensic examiners and police in more efficient handling of such cases. Analyses based on sex, age, topical exposure routes, toxic agents, and mode of death were performed using 217 records of intoxication cases collected from TCMEH as a sample, and the results were compared with reports previously published (from 1999 to 2008) from this institution. Deaths from intoxications occurred at a higher rate in males than in females and were most common among individuals aged 30–39 years. The most frequent method of exposure was oral ingestion. The causative agents of deadly intoxications have changed when compared to the data from the previous 10 years. For instance, deaths from amphetamine overdoses are becoming more prevalent gradually, whereas deaths due to carbon monoxide and rodenticide intoxication have declined dramatically. In 72 cases, pesticides continued to be the most frequent intoxication cause. A total of 60.4% of the deaths were accidental exposure. Men died from accidents at a higher rate than women, although women were more likely to commit suicide. Particular focus is needed on the use of succinylcholine, cyanide, and paraquat in homicides
Distributions and Physical Properties of Molecular Clouds in the Third Galactic Quadrant: = [219.75, 229.75] and = [-5.25, 5.25]
We present the results of an unbiased CO/CO/CO ( =
1-0) survey in a portion of the third Galactic quadrant (TGQ): = [219.75,
229.75] and = [-5.25, 5.25]. The high-resolution and
high-sensitivity data sets help to unravel the distributions and physical
properties of the molecular clouds (MCs) in the mapped area. In the LSR
velocity range from -1 to 85 km/s, the molecular material successfully traces
the Local, Perseus, and Outer arms. In the TGQ, the Outer arm appears to be
more prominent than that in the second Galactic quadrant (SGQ), but the Perseus
arm is not as conspicuous as that in the SGQ. A total of 1,502 CO, 570
CO, and 53 CO molecular structures are identified, spanning over
and orders of magnitude in size and mass, respectively. Tight
mass-radius correlations and virial parameter-mass anticorrelations are
observable. Yet, it seems that no clear correlations between velocity
dispersion and effective radius can be found over the full dynamic range. The
vertical distribution of the MCs renders evident pictures of the Galactic warp
and flare.Comment: 22 pages, 13 figures, 7 tables (with machine-readable versions),
published in ApJ
Anisotropic high cycle fatigue property of Sc and Zr-modified Al-Mg alloy fabricated by laser powder bed fusion
This work investigates the defects (pore and lack of fusion), microstructure, and fatigue properties of Sc and Zr-modified Al–Mg alloy on different building directions fabricated by laser powder bed fusion (LPBF). The results showed that transversely deposited (TD) samples exhibited a superior fatigue strength (100.5 MPa) compared to that (57 MPa) of the parallelly deposited (PD) sample, while their tensile and hardness properties were similar. This phenomenon is attributed to two factors: defects and grain/microstructure. For the defects, the lack of fusion resulted in a higher stress concentration in the PD samples than that of the TD samples in the crack initiation stage. For the microstructure, owing to the indistinctive crack deflection and possible cyclic softening of the columnar grains, a decrement in fatigue resistance appears. Thus, the different crack propagation paths led to different columnar grain/equiaxed grain area ratios for the anisotropic fatigue properties. Furthermore, in the TD samples, some grains, with the || building direction orientation, partly led to a higher fatigue resistance of the TD sample than of the PD sample owing to the exceptional dislocation formation
Hard superconducting gap in PbTe nanowires
Semiconductor nanowires coupled to a superconductor provide a powerful
testbed for quantum device physics such as Majorana zero modes and gate-tunable
hybrid qubits. The performance of these quantum devices heavily relies on the
quality of the induced superconducting gap. A hard gap, evident as vanishing
subgap conductance in tunneling spectroscopy, is both necessary and desired.
Previously, a hard gap has been achieved and extensively studied in III-V
semiconductor nanowires (InAs and InSb). In this study, we present the
observation of a hard superconducting gap in PbTe nanowires coupled to a
superconductor Pb. The gap size () is 1 meV (maximally 1.3 meV
in one device). Additionally, subgap Andreev bound states can also be created
and controlled through gate tuning. Tuning a device into the open regime can
reveal Andreev enhancement of the subgap conductance, suggesting a remarkable
transparent superconductor-semiconductor interface, with a transparency of
0.96. These results pave the way for diverse superconducting quantum
devices based on PbTe nanowires
Ballistic PbTe Nanowire Devices
Disorder is the primary obstacle in current Majorana nanowire experiments.
Reducing disorder or achieving ballistic transport is thus of paramount
importance. In clean and ballistic nanowire devices, quantized conductance is
expected with plateau quality serving as a benchmark for disorder assessment.
Here, we introduce ballistic PbTe nanowire devices grown using the
selective-area-growth (SAG) technique. Quantized conductance plateaus in units
of are observed at zero magnetic field. This observation represents an
advancement in diminishing disorder within SAG nanowires, as none of the
previously studied SAG nanowires (InSb or InAs) exhibit zero-field ballistic
transport. Notably, the plateau values indicate that the ubiquitous valley
degeneracy in PbTe is lifted in nanowire devices. This degeneracy lifting
addresses an additional concern in the pursuit of Majorana realization.
Moreover, these ballistic PbTe nanowires may enable the search for clean
signatures of the spin-orbit helical gap in future devices
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