791 research outputs found
Are you in a Masquerade? Exploring the Behavior and Impact of Large Language Model Driven Social Bots in Online Social Networks
As the capabilities of Large Language Models (LLMs) emerge, they not only
assist in accomplishing traditional tasks within more efficient paradigms but
also stimulate the evolution of social bots. Researchers have begun exploring
the implementation of LLMs as the driving core of social bots, enabling more
efficient and user-friendly completion of tasks like profile completion, social
behavior decision-making, and social content generation. However, there is
currently a lack of systematic research on the behavioral characteristics of
LLMs-driven social bots and their impact on social networks. We have curated
data from Chirper, a Twitter-like social network populated by LLMs-driven
social bots and embarked on an exploratory study. Our findings indicate that:
(1) LLMs-driven social bots possess enhanced individual-level camouflage while
exhibiting certain collective characteristics; (2) these bots have the ability
to exert influence on online communities through toxic behaviors; (3) existing
detection methods are applicable to the activity environment of LLMs-driven
social bots but may be subject to certain limitations in effectiveness.
Moreover, we have organized the data collected in our study into the
Masquerade-23 dataset, which we have publicly released, thus addressing the
data void in the subfield of LLMs-driven social bots behavior datasets. Our
research outcomes provide primary insights for the research and governance of
LLMs-driven social bots within the research community.Comment: 18 pages, 7 figure
Global Convergence of a Nonlinear Conjugate Gradient Method
A modified PRP nonlinear conjugate gradient method to solve unconstrained optimization problems is proposed. The important property of the proposed method is that the sufficient descent property is guaranteed independent of any line search. By the use of the Wolfe line search, the global convergence of the proposed method is established for nonconvex minimization. Numerical results show that the proposed method is effective and promising by comparing with the VPRP, CG-DESCENT, and DL+ methods
Thermal stability and inactivation of hepatitis C virus grown in cell culture
<p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) is a blood-borne flavivirus that infects many millions of people worldwide. Relatively little is known, however, concerning the stability of HCV and reliable procedures for inactivating this virus.</p> <p>Methods</p> <p>In the current study, the thermostability of cell culture-derived HCV (HCVcc, JFH-1 strain) under different environmental temperatures (37°C, room temperature, and 4°C) and the ability of heat, UVC light irradiation, and aldehyde and detergent treatments to inactivate HCVcc were evaluated. The infectious titers of treated viral samples were determined by focus-forming unit (FFU) assay using an indirect immunofluorescence assay for HCV NS3 in hepatoma Huh7-25-CD81 cells highly permissive for HCVcc infection. MTT cytotoxicity assay was performed to determine the concentrations of aldehydes or detergents at which they were no longer cytotoxic.</p> <p>Results</p> <p>HCVcc in culture medium was found to survive 37°C and room temperature (RT, 25 ± 2°C) for 2 and 16 days, respectively, while the virus was relatively stable at 4°C without drastic loss of infectivity for at least 6 weeks. HCVcc in culture medium was sensitive to heat and could be inactivated in 8 and 4 min when incubated at 60°C and 65°C, respectively. However, at 56°C, 40 min were required to eliminate HCVcc infectivity. Addition of normal human serum to HCVcc did not significantly alter viral stability at RT or its susceptibility to heat. UVC light irradiation (wavelength = 253.7 nm) with an intensity of 450 μW/cm<sup>2 </sup>efficiently inactivated HCVcc within 2 min. Exposures to formaldehyde, glutaraldehyde, ionic or nonionic detergents all destroyed HCVcc infectivity effectively, regardless of whether the treatments were conducted in the presence of cell culture medium or human serum.</p> <p>Conclusions</p> <p>The results provide quantitative evidence for the potential use of a variety of approaches for inactivating HCV. The ability of HCVcc to survive ambient temperatures warrants precautions in handling and disposing of objects and materials that may have been contaminated with HCV.</p
A2BE: Accountable Attribute-Based Encryption for Abuse Free Access Control
As a recently proposed public key primitive, attribute-based
encryption (ABE) (including Ciphertext-policy ABE (CP-ABE) and
Key-policy ABE (KP-ABE)) is a highly promising tool for secure
access control. In this paper, the issue of key abuse in ABE is
formulated and addressed. Two kinds of key abuse problems are
considered, i) illegal key sharing among colluding users and ii)
misbehavior of the semi-trusted attribute authority including
illegal key (re-)distribution. Both problems are extremely important
as in an ABE-based access control system, the attribute private keys
directly imply users\u27 privileges to the protected resources. To the
best knowledge of ours, such key abuse problems exist in all current
ABE schemes as the attribute private keys assigned to the users are
never designed to be linked to any user specific information except
the commonly shared user attributes.
To be concrete, we focus on the prevention of key abuse in CP-ABE in
this paper \footnote{Our technique can easily be extended to KP-ABE
as well.}. The notion of accountable CP-ABE (CP-ABE, in short)
is first proposed to prevent illegal key sharing among colluding
users. The accountability for user is achieved by embedding
additional user specific information in the attribute private key
issued to the user. To further obtain accountability for the
attribute authority as well, the notion of strong CP-ABE is
proposed, allowing each attribute private key to be linked to the
corresponding user\u27s secret that is unknown to the attribute
authority. We show how to construct such a strong CP-ABE and
prove its security based on the computational Diffie-Hellman
assumption. Finally, we show how to utilize the new technique to
solve some open problems existed in the previous accountable
identity-based encryption schemes
2,4,6-Tris(2,4-dimethylÂphenÂyl)-1,3,5-triazine
Two virtually superimposable molÂecules comprise the asymmetric unit of the title compound, C27H27N3. The range of dihedral angles between the central 1,3,5-triazine ring and the attached benzene rings is 20.88 (14)–31.36 (14)°, and the shape of each molÂecule is of a flattened bowl. The crystal packing features weak C—H⋯π bonds and π–π interÂactions between triazine and benzene rings [centroid–centroid separations = 3.7696 (17) and 3.7800 (18) Å] that result in the formation of supraÂmolecular layers in the ac plane. The crystal studied was a non-merohedral twin with a minor twin component of 20.7 (3)%
Where to find lossless metals?
Hypothetical metals having optical absorption losses as low as those of the
transparent insulators, if found, could revolutionize optoelectronics. We
perform the first high-throughput search for lossless metals among all known
inorganic materials in the databases of over 100,000 entries. The 381
candidates are identified -- having well-isolated partially-filled bands -- and
are analyzed by defining the figures of merit and classifying their real-space
conductive connectivity. The existing experimental evidence of most candidates
being insulating, instead of conducting, is due to the limitation of current
density functional theory in predicting narrow-band metals that are unstable
against magnetism, structural distortion, or electron-electron interactions. We
propose future research directions including conductive oxides, intercalating
layered materials, and compressing these false-metal candidates under high
pressures into eventual lossless metals.Comment: 36 pages, 86 figures, 3 tabl
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