1,407 research outputs found
Density-functional calculations of the electronic structure and lattice dynamics of superconducting LaOFBiS: Evidence for an electron-phonon interaction near the charge-density-wave instability
We discuss the electronic structure, lattice dynamics and electron-phonon
interaction of newly discovered superconductor LaOFBiS
using density functional based calculations. A strong Fermi surface nesting at
=(,,0) suggests a proximity to charge density wave
instability and leads to imaginary harmonic phonons at this point
associated with in-plane displacements of S atoms. Total energy analysis
resolves only a shallow double-well potential well preventing the appearance of
static long-range order. Both harmonic and anharmonic contributions to
electron-phonon coupling are evaluated and give a total coupling constant
prompting this material to be a conventional
superconductor contrary to structurally similar FeAs materials.Comment: Supplementary Materials is adde
Sympathy and Punishment: Evolution of Cooperation in Public Goods Game
An important way to maintain human cooperation is punishing defection. However, since punishment is costly, how can it arise and evolve given that individuals who contribute but do not punish fare better than the punishers? This leads to a violation of causality, since the evolution of punishment is prior to the one of cooperation behaviour in evolutionary dynamics. Our public goods game computer simulations based on generalized Moran Process, show that, if there exists a \'behaviour-based sympathy\' that compensates those who punish at a personal cost, the way for the emergence and establishment of punishing behaviour is paved. In this way, the causality violation dissipates. Among humans sympathy can be expressed in many ways such as care, praise, solace, ethical support, admiration, and sometimes even adoration; in our computer simulations, we use a small amount of transfer payment to express \'behaviour-based sympathy\'. Our conclusions indicate that, there exists co-evolution of sympathy, punishment and cooperation. According to classical philosophy literature, sympathy is a key factor in morality and justice is embodied by punishment; in modern societies, both the moral norms and the judicial system, the representations of sympathy and punishment, play an essential role in stable social cooperation.Public Goods Game, Cooperation, Social Dilemma, Co-Evolution, Sympathy, Punishment
Large Language Models in Finance: A Survey
Recent advances in large language models (LLMs) have opened new possibilities
for artificial intelligence applications in finance. In this paper, we provide
a practical survey focused on two key aspects of utilizing LLMs for financial
tasks: existing solutions and guidance for adoption.
First, we review current approaches employing LLMs in finance, including
leveraging pretrained models via zero-shot or few-shot learning, fine-tuning on
domain-specific data, and training custom LLMs from scratch. We summarize key
models and evaluate their performance improvements on financial natural
language processing tasks.
Second, we propose a decision framework to guide financial professionals in
selecting the appropriate LLM solution based on their use case constraints
around data, compute, and performance needs. The framework provides a pathway
from lightweight experimentation to heavy investment in customized LLMs.
Lastly, we discuss limitations and challenges around leveraging LLMs in
financial applications. Overall, this survey aims to synthesize the
state-of-the-art and provide a roadmap for responsibly applying LLMs to advance
financial AI.Comment: Accepted by 4th ACM International Conference on AI in Finance
(ICAIF-23) https://ai-finance.or
A Novel Application of Boolean Functions with High Algebraic Immunity in Minimal Codes
Boolean functions with high algebraic immunity are important cryptographic
primitives in some stream ciphers. In this paper, two methodologies for
constructing binary minimal codes from sets, Boolean functions and vectorial
Boolean functions with high algebraic immunity are proposed. More precisely, a
general construction of new minimal codes using minimal codes contained in
Reed-Muller codes and sets without nonzero low degree annihilators is
presented. The other construction allows us to yield minimal codes from certain
subcodes of Reed-Muller codes and vectorial Boolean functions with high
algebraic immunity. Via these general constructions, infinite families of
minimal binary linear codes of dimension and length less than or equal to
are obtained. In addition, a lower bound on the minimum distance of
the proposed minimal linear codes is established. Conjectures and open problems
are also presented. The results of this paper show that Boolean functions with
high algebraic immunity have nice applications in several fields such as
symmetric cryptography, coding theory and secret sharing schemes
Progesterone Prevents Traumatic Brain Injury-Induced Intestinal Nuclear Factor kappa B Activation and Proinflammatory Cytokines Expression in Male Rats
We have previously shown that traumatic brain injury (TBI) can induce an upregulation of nuclear factor kappa B (NF-κB) and proinflammatory cytokines in the gut, which play an important role in the pathogenesis of acute gut mucosal injury mediated by inflammation. In this work, we investigated whether progesterone administration modulated intestinal NF-κB activity and proinflammatory cytokines expression after TBI in male rats. As a result, we found that administration of progesterone following TBI could decrease NF-κB binding activity, NF-κB p65 protein expression, and concentrations of interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in the gut. TBI-induced damages of gut structure were ameliorated after progesterone injections. The results of the present study suggest that the therapeutic benefit of post-TBI progesterone injections might be due to its inhibitory effects on intestinal NF-κB activation and proinflammatory cytokines expression
Electric-field control of magnetic ordering in the tetragonal BiFeO3
We propose a way to use electric-field to control the magnetic ordering of
the tetragonal BiFeO3. Based on systematic first-principles studies of the
epitaxial strain effect on the ferroelectric and magnetic properties of the
tetragonal BiFeO3, we find that there exists a transition from C-type to G-type
antiferromagnetic (AFM) phase at in-plane constant a ~ 3.905 {\AA} when the
ferroelectric polarization is along [001] direction. Such magnetic phase
transition can be explained by the competition between the Heisenberg exchange
constant J1c and J2c under the influence of biaxial strain. Interestingly, when
the in-plane lattice constant enlarges, the preferred ferroelectric
polarization tends to be canted and eventually lies in the plane (along [110]
direction). It is found that the orientation change of ferroelectric
polarization, which can be realized by applying external electric-field, has
significant impact on the Heisenberg exchange parameters and therefore the
magnetic orderings of tetragonal BiFeO3. For example, at a ~ 3.79 {\AA}, an
electric field along [111] direction with magnitude of 2 MV/cm could change the
magnetic ordering from C-AFM to G-AFM. As the magnetic ordering affects many
physical properties of the magnetic material, e.g. magnetoresistance, we expect
such strategy would provide a new avenue to the application of multiferroic
materials.Comment: 4 pages, 4 figure
- …