49 research outputs found
SUN: Exploring Intrinsic Uncertainties in Text-to-SQL Parsers
This paper aims to improve the performance of text-to-SQL parsing by
exploring the intrinsic uncertainties in the neural network based approaches
(called SUN). From the data uncertainty perspective, it is indisputable that a
single SQL can be learned from multiple semantically-equivalent
questions.Different from previous methods that are limited to one-to-one
mapping, we propose a data uncertainty constraint to explore the underlying
complementary semantic information among multiple semantically-equivalent
questions (many-to-one) and learn the robust feature representations with
reduced spurious associations. In this way, we can reduce the sensitivity of
the learned representations and improve the robustness of the parser. From the
model uncertainty perspective, there is often structural information
(dependence) among the weights of neural networks. To improve the
generalizability and stability of neural text-to-SQL parsers, we propose a
model uncertainty constraint to refine the query representations by enforcing
the output representations of different perturbed encoding networks to be
consistent with each other. Extensive experiments on five benchmark datasets
demonstrate that our method significantly outperforms strong competitors and
achieves new state-of-the-art results. For reproducibility, we release our code
and data at https://github.com/AlibabaResearch/DAMO-ConvAI/tree/main/sunsql.Comment: Accepted at COLING 202
Effect of saline stress on the physiology and growth of maize hybrids and their related inbred lines
Salinity is one major abiotic stress that restrict plant growth and crop productivity. In maize (Zea mays L), salt stress causes significant yield loss each year. However, indices of maize response to salt stress are not completely explored and a desired method for maize salt tolerance evaluation is still not established. A Chinese leading maize variety Jingke968 showed various resistance to environmental factors, including salt stress. To compare its salt tolerance to other superior maize varieties, we examined the physiological and growth responses of three important maize hybrids and their related inbred lines under the control and salt stress conditions. By compar- ing the physiological parameters under control and salt treatment, we demonstrated that different salt tolerance mechanisms may be involved in different genotypes, such as the elevation of superoxide dismutase activity and/ or proline content. With Principal Component Analysis of all the growth indicators in both germination and seedling stages, along with the germination rate, superoxide dismutase activity, proline content, malondialdehyde content, relative electrolyte leakage, we were able to show that salt resistance levels of hybrids and their related inbred lines were Jingke968 > Zhengdan958 > X1132 and X1132M > Jing724 > Chang7-2 > Zheng58 > X1132F, respectively, which was consistent with the saline field observation. Our results not only contribute to a better understanding of salt stress response in three important hybrids and their related inbred lines, but also this evaluation system might be applied for an accurate assessment of salt resistance in other germplasms and breeding material
Evidence of Noncollinear Spin Texture in Magnetic Moir\'e Superlattices
Moir\'e magnetism, parallel with moir\'e electronics that has led to novel
correlated and topological electronic states, emerges as a new venue to design
and control exotic magnetic phases in twisted magnetic two-dimensional(2D)
crystals. Here, we report direct evidence of noncollinear spin texture in 2D
twisted double bilayer (tDB) magnet chromium triiodide (CrI). Using
magneto-optical spectroscopy in tDB CrI, we revealed the presence of a net
magnetization, unexpected from the composing antiferromagnetic bilayers with
compensated magnetizations, and the emergence of noncollinear spins, originated
from the moir\'e exchange coupling-induced spin frustrations. Exploring the
twist angle dependence, we demonstrated that both features are present in tDB
CrI with twist angles from 0.5 to 5, but are most prominent in the
1.1 tDB CrI. Focusing on the temperature dependence of the 1.1 tDB
CrI, we resolved the dramatic suppression in the net magnetization onset
temperature and the significant softening of noncollinear spins, as a result of
the moir\'e induced frustration. Our results demonstrate the power of moir\'e
superlattices in introducing novel magnetic phenomena that are absent in
natural 2D magnets
Magnetic field-induced quantum phase transitions in a van der Waals magnet
Exploring new parameter regimes to realize and control novel phases of matter
has been a main theme in modern condensed matter physics research. The recent
discovery of 2D magnetism in nearly freestanding monolayer atomic crystals has
already led to observations of a number of novel magnetic phenomena absent in
bulk counterparts. Such intricate interplays between magnetism and crystalline
structures provide ample opportunities for exploring quantum phase transitions
in this new 2D parameter regime. Here, using magnetic field and temperature
dependent circularly polarized Raman spectroscopy of phonons and magnons, we
map out the phase diagram of CrI3 that has been known to be a layered AFM in
its 2D films and a FM in its 3D bulk. We, however, reveal a novel mixed state
of layered AFM and FM in 3D CrI3 bulk crystals where the layered AFM survives
in the surface layers and the FM appears in deeper bulk layers. We then show
that the surface layered AFM transits into the FM at a critical magnetic field
of 2 T, similar to what was found in the few layer case. Interestingly,
concurrent with this magnetic phase transition, we discover a first-order
structural phase transition that alters the crystallographic point group from
C3i to C2h and thus, from a symmetry perspective, this monoclinic structural
phase belongs to the 3D nematic order universality class. Our result not only
unveils the complex single magnon behavior in 3D CrI3, but also settles down
the puzzle of how CrI3 transits from a bulk FM to a thin layered AFM
semiconductor, despite recent efforts in understanding the origin of layered
AFM in CrI3 thin layer, and reveals the intimate relationship between the
layered AFM-to-FM and the crystalline rhombohedral-to-monoclinic phase
transitions. These findings further open up opportunities for future 2D
magnet-based magneto-mechanical devices
Exploring the Potential of Integrated Optical Sensing and Communication (IOSAC) Systems with Si Waveguides for Future Networks
Advanced silicon photonic technologies enable integrated optical sensing and
communication (IOSAC) in real time for the emerging application requirements of
simultaneous sensing and communication for next-generation networks. Here, we
propose and demonstrate the IOSAC system on the silicon nitride (SiN) photonics
platform. The IOSAC devices based on microring resonators are capable of
monitoring the variation of analytes, transmitting the information to the
terminal along with the modulated optical signal in real-time, and replacing
bulk optics in high-precision and high-speed applications. By directly
integrating SiN ring resonators with optical communication networks,
simultaneous sensing and optical communication are demonstrated by an optical
signal transmission experimental system using especially filtering amplified
spontaneous emission spectra. The refractive index (RI) sensing ring with a
sensitivity of 172 nm/RIU, a figure of merit (FOM) of 1220, and a detection
limit (DL) of 8.2*10-6 RIU is demonstrated. Simultaneously, the 1.25 Gbps
optical on-off-keying (OOK) signal is transmitted at the concentration of
different NaCl solutions, which indicates the bit-error-ratio (BER) decreases
with the increase in concentration. The novel IOSAC technology shows the
potential to realize high-performance simultaneous biosensing and communication
in real time and further accelerate the development of IoT and 6G networks.Comment: 11pages, 5 figutre
Effect of steam reinjection mass flow rate on the SOFC–GT system with steam reinjection
A solid oxide fuel cell (SOFC) is regarded as the first choice of high-efficiency and clean power generation technology in the 21st century due to its characteristics of high power generation efficiency and low pollutant emission. In this paper, hydrogen is used as a fuel for SOFCs using the EBSILON platform. A sensitivity analysis of the solid oxide fuel cell–gas turbine (SOFC–GT) system with steam reinjection is carried out to investigate the effect of the steam reinjection mass flow rate on the improvement of the electrical efficiency of the system and on the values of the other parameters. The results show that the variation in the steam reinjection mass flow rate has an effect on other parameters. Changes in several parameters affect the electrical efficiency of the system, which reaches 74.11% at a pressure ratio of 10, SOFC inlet temperature of 783.15 K, turbine back pressure of 70 kPa, and steam reinjection mass flow rate of 6.16 kg/s. Future research can optimize the overall parameter selection of the system in terms of economy and other aspects