27 research outputs found
PQLM -- Multilingual Decentralized Portable Quantum Language Model for Privacy Protection
With careful manipulation, malicious agents can reverse engineer private
information encoded in pre-trained language models. Security concerns motivate
the development of quantum pre-training. In this work, we propose a highly
portable quantum language model (PQLM) that can easily transmit information to
downstream tasks on classical machines. The framework consists of a cloud PQLM
built with random Variational Quantum Classifiers (VQC) and local models for
downstream applications. We demonstrate the ad hoc portability of the quantum
model by extracting only the word embeddings and effectively applying them to
downstream tasks on classical machines. Our PQLM exhibits comparable
performance to its classical counterpart on both intrinsic evaluation (loss,
perplexity) and extrinsic evaluation (multilingual sentiment analysis accuracy)
metrics. We also perform ablation studies on the factors affecting PQLM
performance to analyze model stability. Our work establishes a theoretical
foundation for a portable quantum pre-trained language model that could be
trained on private data and made available for public use with privacy
protection guarantees.Comment: 5 pages, 3 figures, 3 table
Localization and mapping algorithm based on Lidar-IMU-Camera fusion
Positioning and mapping technology is a difficult and hot topic in autonomous driving environment sensing systems. In a complex traffic environment, the signal of the Global Navigation Satellite System (GNSS) will be blocked, leading to inaccurate vehicle positioning. To ensure the security of automatic electric campus vehicles, this study is based on the Lightweight and Ground-Optimized Lidar Odometry and Mapping on Variable Terrain (LEGO-LOAM) algorithm with a monocular vision system added. An algorithm framework based on Lidar-IMU-Camera (Lidar means light detection and ranging) fusion was proposed. A lightweight monocular vision odometer model was used, and the LEGO-LOAM system was employed to initialize monocular vision. The visual odometer information was taken as the initial value of the laser odometer. At the back-end opti9mization phase error state, the Kalman filtering fusion algorithm was employed to fuse the visual odometer and LEGO-LOAM system for positioning. The visual word bag model was applied to perform loopback detection. Taking the test results into account, the laser radar loopback detection was further optimized, reducing the accumulated positioning error. The real car experiment results showed that our algorithm could improve the mapping quality and positioning accuracy in the campus environment. The Lidar-IMU-Camera algorithm framework was verified on the Hong Kong city dataset UrbanNav. Compared with the LEGO-LOAM algorithm, the results show that the proposed algorithm can effectively reduce map drift, improve map resolution, and output more accurate driving trajectory information
Unidirectional brain-computer interface: Artificial neural network encoding natural images to fMRI response in the visual cortex
While significant advancements in artificial intelligence (AI) have catalyzed
progress across various domains, its full potential in understanding visual
perception remains underexplored. We propose an artificial neural network
dubbed VISION, an acronym for "Visual Interface System for Imaging Output of
Neural activity," to mimic the human brain and show how it can foster
neuroscientific inquiries. Using visual and contextual inputs, this multimodal
model predicts the brain's functional magnetic resonance imaging (fMRI) scan
response to natural images. VISION successfully predicts human hemodynamic
responses as fMRI voxel values to visual inputs with an accuracy exceeding
state-of-the-art performance by 45%. We further probe the trained networks to
reveal representational biases in different visual areas, generate
experimentally testable hypotheses, and formulate an interpretable metric to
associate these hypotheses with cortical functions. With both a model and
evaluation metric, the cost and time burdens associated with designing and
implementing functional analysis on the visual cortex could be reduced. Our
work suggests that the evolution of computational models may shed light on our
fundamental understanding of the visual cortex and provide a viable approach
toward reliable brain-machine interfaces
Correlated spectro-polarimetric study along the Z track in XTE J1701-462 puts constraints on its coronal geometry
Context. In September 2022, the transient neutron star low-mass X-ray binary
XTE J1701-462 went into a new outburst. Aims. The objective of this work is to
examine the evolution of the accretion geometry of XTE J1701-462 by studying
the spectro-polarimetric properties along the Z track of this source. The
simultaneous observations archived by the Insight-Hard X-ray Modulation
Telescope (HXMT) and the Imaging X-ray Polarimetry Explorer (IXPE) give us the
opportunity. Methods. We present a comprehensive X-ray spectro-polarimetric
analysis of XTE J1701-462, using simultaneous observations from IXPE,
Insight-HXMT and NuSTAR. For IXPE observations, two methods are employed to
measure the polarization: a model-independent measurement with PCUBE and a
model-dependent polarization-spectral analysis with XSPEC. The corresponding
spectra from Insight-HXMT and NuSTAR are studied with two configurations that
correspond to a slab-like corona and a spherical shell-like corona,
respectively. Results. Significant polarization characteristics are detected in
XTE J1701-462. The polarization degree shows a decreasing trend along the Z
track, reducing from (4.84 0.37)% to (3.76 0.43)% on the horizontal
branch and jumping to less than 1% on the normal branch. The simultaneous
spectral analysis from Insight-HXMT and NuSTAR suggests that the redistribution
between the thermal and Comptonized emission could be the reason for the PD
evolution along the Z track. Based on the correlated spectro-polarimetric
properties, we propose that this source likely has a slab coronal geometry and
the size/thickness of the corona decreases along the Z track
Rats use memory confidence to guide decisions.
Memory enables access to past experiences to guide future behavior. Humans can determine which memories to trust (high confidence) and which to doubt (low confidence). How memory retrieval, memory confidence, and memory-guided decisions are related, however, is not understood. In particular, how confidence in memories is used in decision making is unknown. We developed a spatial memory task in which rats were incentivized to gamble their time: betting more following a correct choice yielded greater reward. Rat behavior reflected memory confidence, with higher temporal bets following correct choices. We applied machine learning to identify a memory decision variable and built a generative model of memories evolving over time that accurately predicted both choices and confidence reports. Our results reveal in rats an ability thought to exist exclusively in primates and introduce a unified model of memory dynamics, retrieval, choice, and confidence
The First Polarimetric View on Quasi-Periodic Oscillations in a Black Hole X-ray Binary
We present the first polarimetric analysis of Quasi-Periodic Oscillations
(QPO) in a black hole binary utilizing \textit{IXPE} data. Our study focuses on
Swift J1727.8--1613, which experienced a massive outburst that was observed by
various telescopes across different wavelengths. The \textit{IXPE} observation
we studied was conducted during the Hard-Intermediate state. The polarization
degree (PD) and polarization angle (PA) were measured at 4.280.20\% and
, respectively. Remarkably, significant QPO signals
were detected during this observation, with a QPO frequency of approximately
1.34 Hz and a fractional root-mean-square (RMS) amplitude of about 12.3\%.
Furthermore, we conducted a phase-resolved analysis of the QPO using the
Hilbert-Huang transform technique. The photon index showed a strong modulation
with respect to the QPO phase. In contrast, the PD and PA exhibit no
modulations in relation to the QPO phase, which is inconsistent with the
expectation of the Lense-Thirring precession of the inner flow. Further
theoretical studies are needed to conform with the observational results.Comment: Accepted for publication in APJ
The mHz quasi-regular modulations of 4U 1630--47 during its 1998 outburst
We present the results of a detailed timing and spectral analysis of the
quasi-regular modulation (QRM) phenomenon in the black hole X-ray binary 4U
1630--47 during its 1998 outburst observed by Rossi X-ray Timing Explore
(RXTE). We find that the 50-110 mHz QRM is flux dependent, and the QRM
is detected with simultaneous low frequency quasi-periodic oscillations
(LFQPOs). According to the behavior of the power density spectrum, we divide
the observations into four groups. In the first group, namely behavior A,
LFQPOs are detected, but no mHz QRM. The second group, namely behavior B, a QRM
with frequency above 88 mHz is detected and the 5 Hz and 7
Hz LFQPOs are almost overlapping. In the third group, namely behavior C, the
QRM frequency below 88 mHz is detected and the LFQPOs are significantly
separated. In the forth group, namely behavior D, neither QRM nor LFQPOs are
detected. We study the energy-dependence of the fractional rms, centroid
frequency, and phase-lag of QRM and LFQPOs for behavior B and C. We then study
the evolution of QRM and find that the frequency of QRM increases with
hardness, while its rms decreases with hardness. We also analyze the spectra of
each observation, and find that the QRM rms of behavior B has a positive
correlation with / . Finally, we give
our understanding for this mHz QRM phenomena.Comment: 14pages, 15 figure
Genome-Wide Identification and Characterization of Salvia miltiorrhiza Laccases Reveal Potential Targets for Salvianolic Acid B Biosynthesis
Laccases are widely distributed in plant kingdom catalyzing the polymerization of lignin monolignols. Rosmarinic acid (RA) has a lignin monolignol-like structure and is converted into salvianolic acid B (SAB), which is a representatively effective hydrophilic compound of a well-known medicinal plant Salvia miltiorrhiza and also the final compound of phenolic acids metabolism pathway in the plant. But the roles of laccases in the biosynthesis of SAB are poorly understood. This work systematically characterizes S. miltiorrhiza laccase (SmLAC) gene family and identifies the SAB-specific candidates. Totally, 29 laccase candidates (SmLAC1-SmLAC29) are found to contain three signature Cu-oxidase domains. They present relatively low sequence identity and diverse intron–exon patterns. The phylogenetic clustering of laccases from S. miltiorrhiza and other ten plants indicates that the 29 SmLACs can be divided into seven groups, revealing potential distinct functions. Existence of diverse cis regulatory elements in the SmLACs promoters suggests putative interactions with transcription factors. Seven SmLACs are found to be potential targets of miR397. Putative glycosylation sites and phosphorylation sites are identified in SmLAC amino acid sequences. Moreover, the expression profile of SmLACs in different organs and tissues deciphers that 5 SmLACs (SmLAC7/8/20/27/28) are expressed preferentially in roots, adding the evidence that they may be involved in the phenylpropanoid metabolic pathway. Besides, silencing of SmLAC7, SmLAC20 and SmLAC28, and overexpression of SmLAC7 and SmLAC20 in the hairy roots of S. miltiorrhiza result in diversification of SAB, signifying that SmLAC7 and SmLAC20 take roles in SAB biosynthesis. The results of this study lay a foundation for further elucidation of laccase functions in S. miltiorrhiza, and add to the knowledge for SAB biosynthesis in S. miltiorrhiza