202 research outputs found
Implementing BERT and fine-tuned RobertA to detect AI generated news by ChatGPT
The abundance of information on social media has increased the necessity of
accurate real-time rumour detection. Manual techniques of identifying and
verifying fake news generated by AI tools are impracticable and time-consuming
given the enormous volume of information generated every day. This has sparked
an increase in interest in creating automated systems to find fake news on the
Internet. The studies in this research demonstrate that the BERT and RobertA
models with fine-tuning had the best success in detecting AI generated news.
With a score of 98%, tweaked RobertA in particular showed excellent precision.
In conclusion, this study has shown that neural networks can be used to
identify bogus news AI generation news created by ChatGPT. The RobertA and BERT
models' excellent performance indicates that these models can play a critical
role in the fight against misinformation
A Fast and Provable Algorithm for Sparse Phase Retrieval
We study the sparse phase retrieval problem, which aims to recover a sparse
signal from a limited number of phaseless measurements. Existing algorithms for
sparse phase retrieval primarily rely on first-order methods with linear
convergence rate. In this paper, we propose an efficient second-order algorithm
based on Newton projection, which maintains the same per-iteration
computational complexity as popular first-order methods. The proposed algorithm
is theoretically guaranteed to converge to the ground truth (up to a global
sign) at a quadratic convergence rate after at most iterations, provided
a sample complexity of , where represents an -sparse ground truth signal. Numerical
experiments demonstrate that our algorithm not only outperforms
state-of-the-art methods in terms of achieving a significantly faster
convergence rate, but also excels in attaining a higher success rate for exact
signal recovery from noise-free measurements and providing enhanced signal
reconstruction in noisy scenarios
Cosmological Fisher forecasts for next-generation spectroscopic surveys
Next-generation spectroscopic surveys such as the MegaMapper, MUltiplexed
Survey Telescope (MUST), MaunaKea Spectroscopic Explorer (MSE), and Wide
Spectroscopic Telescope (WST) are foreseen to increase the number of
galaxy/quasar redshifts by an order of magnitude, with hundred millions of
spectra that will be measured at . We perform a Fisher matrix analysis for
these surveys on the baryonic acoustic oscillation (BAO), the redshift-space
distortion (RSD) measurement, the non-Gaussianity amplitude , and
the total neutrino mass . For BAO and RSD parameters, these surveys may
achieve precision at sub-percent level (<0.5 per cent), representing an
improvement of factor 10 w.r.t. the latest database. For NG, these surveys may
reach an accuracy of . They can also put a tight
constraint on with if we do joint
analysis with Planck and even if combined with other data. In
addition, we introduce a general survey model, to derive the cosmic volume and
number density of tracers, given instrumental facilities and survey strategy.
Using our Fisher formalism, we can explore (continuously) a wide range of
survey observational parameters, and propose different survey strategies that
optimise the cosmological constraints. Fixing the fibre number and survey
duration, we show that the best strategy for and
measurement is to observe large volumes, despite the noise increase. However,
the strategy differs for the apparent magnitude limit. Finally, we prove that
increasing the fibre number improves measurement but not
significantly .Comment: 15 pages, 9 figure
Research on dedicated rail power supply system for electric cars
in order to improve the endurance capacity and driving safety of electric vehicles, a special track power supply system for
electric cars on expressways is studied. The working principle of the main components of the system, such as sliding contact charging track
and mechanical charging arm, is simulated and analyzed by using SolidWorks software. The results show that the charging function of the
contact track can provide unlimited endurance for electric vehicles, and the guidance function of the track can also ensure the safety of highspeed driving
WaveDM: Wavelet-Based Diffusion Models for Image Restoration
Latest diffusion-based methods for many image restoration tasks outperform
traditional models, but they encounter the long-time inference problem. To
tackle it, this paper proposes a Wavelet-Based Diffusion Model (WaveDM) with an
Efficient Conditional Sampling (ECS) strategy. WaveDM learns the distribution
of clean images in the wavelet domain conditioned on the wavelet spectrum of
degraded images after wavelet transform, which is more time-saving in each step
of sampling than modeling in the spatial domain. In addition, ECS follows the
same procedure as the deterministic implicit sampling in the initial sampling
period and then stops to predict clean images directly, which reduces the
number of total sampling steps to around 5. Evaluations on four benchmark
datasets including image raindrop removal, defocus deblurring, demoir\'eing,
and denoising demonstrate that WaveDM achieves state-of-the-art performance
with the efficiency that is comparable to traditional one-pass methods and over
100 times faster than existing image restoration methods using vanilla
diffusion models
Short Video Activism With and on Douyin: An Innovative Repertoire of Contention for Chinese Consumers
This article examines consumer video activism tactics in China and their impact on Chinese consumers and society. Drawing upon 56 semistructured interviews and a case study analysis of Chinese online consumer protest in 2018, we argue that short-video-activism tactics have become an innovative repertoire of contention for Chinese consumers and Douyin, the “sister app” of TikTok, has become a real-time updated database of this repertoire. Using Douyin as a case study, we argue that it plays three key roles in mediating Chinese consumer activism: a techno-cultural construct that affords highly heterogeneous users to present everyday experiences via short videos; a multisided market that profoundly affects the tactics consumers choose to amplify their voices; and a governing entity that both moderates content for its users and simultaneously is subject to government regulations
Growth and nutrient dynamics of transplanted Quercus variabilis seedlings as influenced by pre-hardening and fall fertilization
Stored nutrient reserves are closely correlated with survival and growth of transplanted seedlings. Previous studies have proven that combining pre-hardening fertilization (PF) with fall fertilization (FF) built seedling nutrient reserves more effectively; however, their effect on transplanting performance is poorly documented. We investigated the independent and interacting effects of 2 levels of PF and 4 levels of FF on seedling growth, nutrient acquisition and accumulation during different growth phases 1 year after transplanting of Blume in a nursery. High PF benefited nutrient reserves and subsequent transplanted seedling growth and tissue nutrient storage at the end of the rapid growth and hardening phases. Fall fertilization with 36 mg N increased stem dry mass and tissue nutrient content at the end of the hardening phase. At the conclusion of establishment, PF and FF showed a significant interaction for N and K uptake from soil. At the end of the rapid growth and hardening phases, high PF consistently increased nutrient uptake. Enhanced N and K uptake occurred following application of 36 mg N of FF at the end of the hardening phase. Distinct roles for PF and FF on 3 phases of transplanted seedlings demonstrated the necessity to evaluate fertilization in terms of nutrient reserves and subsequent transplanting performance in consecutive phases. Combining 100 mg N seedling during pre-hardening with 36 mg N seedling during fall yielded ideal transplanting performance for seedlings.Quercus variabilis â1â1Quercus variabili
Symmetry breaking induced insulating electronic state in PbCu(PO)O
The recent experimental claim of room-temperature ambient-pressure
superconductivity in a Cu-doped lead-apatite (LK-99) has ignited substantial
research interest in both experimental and theoretical domains. Previous
density functional theory (DFT) calculations with the inclusion of an on-site
Hubbard interaction consistently predict the presence of flat bands
crossing the Fermi level. This is in contrast to DFT plus dynamical mean field
theory calculations, which reveal the Mott insulating behavior for the
stoichiometric PbCu(PO)O compound. Nevertheless, the existing
calculations are all based on the structure, which is argued to be not
the ground-state structure. Here, we revisit the electronic structure of
PbCu(PO)O with the energetically more favorable
structure, fully taking into account electronic symmetry breaking. We examine
all possible configurations for Cu substituting the Pb sites. Our results show
that the doped Cu atoms exhibit a preference for substituting the Pb2 sites
than the Pb1 sites. In both cases, the calculated substitutional formation
energies are large, indicating the difficulty in incorporating Cu at the Pb
sites. We find that most of structures with Cu at the Pb2 site tend to be
insulating, while the structures with both two Cu atoms at the Pb1 sites
(except one configuration) are predicted to be metallic by DFT+
calculations. However, when accounting for the electronic symmetry breaking,
some Cu-doped configurations previously predicted to be metallic (including the
structure studied in previous DFT+ calculations) become insulating. Our work
highlights the importance of symmetry breaking in obtaining correct electronic
state for PbCu(PO)O, thereby reconciling previous DFT+ and
DFT+DMFT calculations.Comment: 19 pages, 9 figures (including Supplementary Material
Study of the Bus Dynamic Coscheduling Optimization Method under Urban Rail Transit Line Emergency
As one of the most important urban commuter transportation modes, urban rail transit (URT) has been acting as a key solution for supporting mobility needs in high-density urban areas. However, in recent years, high frequency of unexpected events has caused serious service disruptions in URT system, greatly harming passenger safety and resulting in severe traffic delays. Therefore, there is an urgent need to study emergency evacuation problem in URT. In this paper, a method of bus dynamic coscheduling is proposed and two models are built based on different evacuation destinations including URT stations and surrounding bus parking spots. A dynamic coscheduling scheme for buses can be obtained by the models. In the model solution process, a new concept—the equivalent parking spot—is proposed to transform the nonlinear model into an integer linear programming (ILP) problem. A case study is conducted to verify the feasibility of models. Also, sensitivity analysis of two vital factors is carried out to analyze their effects on the total evacuation time. The results reveal that the designed capacity of buses has a negative influence on the total evacuation time, while an increase in the number of passengers has a positive effect. Finally, some significant optimizing strategies are proposed
Void Lensing in Cubic Galileon Gravity
Weak lensing studies via cosmic voids are a promising probe of Modified
Gravity (MG). Excess surface mass density (ESD) is widely used as a lensing
statistic in weak lensing research. In this paper, we use the ray-tracing
method to study the ESD around voids in simulations based on Cubic Galileon
(CG) gravity. With the compilation of N-body simulation and ray-tracing method,
changes in structure formation and deflection angle resulting from MG can both
be considered, making the extraction of lensing signals more realistic. We find
good agreements between the measurement and theoretical prediction of ESD for
CG gravity. Meanwhile, the lensing signals are much less affected by the change
of the deflection angle than the change of the structure formation, indicating
a good approximation of regarding ESD (statistics) as the projection of 3D dark
matter density field. Finally, we demonstrate that it is impossible to
distinguish CG and General Relativity in our simulation, however, in the
next-generation survey, thanks to the large survey area and the increased
galaxy number density, detecting the differences between these two models is
possible. The methodology employed in this paper that combines N-body
simulation and ray-tracing method can be a robust way to measure the lensing
signals from simulations based on the MGs, and especially on that which
significantly modifies the deflection angle.Comment: 14 pages, 9 figure
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