668 research outputs found
Exploring Downvoting in Blockchain-based Online Social Media Platforms
In recent years, Blockchain-based Online Social Media (BOSM) platforms have
evolved fast due to the advancement of blockchain technology. BOSM can
effectively overcome the problems of traditional social media platforms, such
as a single point of trust and insufficient incentives for users, by combining
a decentralized governance structure and a cryptocurrency-based incentive
model, thereby attracting a large number of users and making it a crucial
component of Web3. BOSM allows users to downvote low-quality content and aims
to decrease the visibility of low-quality content by sorting and filtering it
through downvoting. However, this feature may be maliciously exploited by some
users to undermine the fairness of the incentive, reduce the quality of highly
visible content, and further reduce users' enthusiasm for content creation and
the attractiveness of the platform. In this paper, we study and analyze the
downvoting behavior using four years of data collected from Steemit, the
largest BOSM platform. We discovered that a significant number of bot accounts
were actively downvoting content. In addition, we discovered that roughly 9% of
the downvoting activity might be retaliatory. We did not detect any significant
instances of downvoting on content for a specific topic. We believe that the
findings in this paper will facilitate the future development of user behavior
analysis and incentive pattern design in BOSM and Web3
Study on a Frequency Fluctuation Attenuation Method for the Parallel Multi-VSG System
Virtual synchronous generator (VSG) is one of the inverter control methods which can provide extra virtual moment of inertia and achieve frequency support by mimicking the output characteristics of a rotating synchronous generator (RSG), which makes VSG particularly suitable for multi-access point applications, or called the multi-VSG system. However, frequency fluctuations may often occur in the case of power variation. In terms of this issue, this study presents the small-signal state-space model of VSG and analyzes the cause of frequency fluctuation, first. And then, a novel VSG control method is proposed for frequency fluctuation attenuation. The proposed method is especially fit for the parallel multi-VSG system because it does not take grid angular frequency into computation so that it can get rid of the ill effect introduced through PLL. The damping power item is reconstrued with a new means to judge whether the system is in a steady state or not. At the same time, the parametric design method of the proposed method is also figured out. Finally, the simulation experiments are performed, and the results verify that the proposed method performs better than the conventional one in terms of dynamic response and power-sharing among the multi-VSG system
How to Differentiate between Near Field and Far Field: Revisiting the Rayleigh Distance
Future wireless communication systems are likely to adopt extremely large
aperture arrays and millimeter-wave/sub-THz frequency bands to achieve higher
throughput, lower latency, and higher energy efficiency. Conventional wireless
systems predominantly operate in the far field (FF) of the radiation source of
signals. As the array size increases and the carrier wavelength shrinks,
however, the near field (NF) becomes non-negligible. Since the NF and FF differ
in many aspects, it is essential to distinguish their corresponding regions. In
this article, we first provide a comprehensive overview of the existing NF-FF
boundaries, then introduce a novel NF-FF demarcation method based on effective
degrees of freedom (EDoF) of the channel. Since EDoF is intimately related to
spectral efficiency, the EDoF-based border is able to characterize key channel
performance more accurately, as compared with the classic Rayleigh distance.
Furthermore, we analyze the main features of the EDoF-based NF-FF boundary and
provide insights into wireless system design
Universal Self-adaptive Prompting
A hallmark of modern large language models (LLMs) is their impressive general
zero-shot and few-shot abilities, often elicited through prompt-based and/or
in-context learning. However, while highly coveted and being the most general,
zero-shot performances in LLMs are still typically weaker due to the lack of
guidance and the difficulty of applying existing automatic prompt design
methods in general tasks when ground-truth labels are unavailable. In this
study, we address this by presenting Universal Self-adaptive Prompting (USP),
an automatic prompt design approach specifically tailored for zero-shot
learning (while compatible with few-shot). Requiring only a small amount of
unlabeled data & an inference-only LLM, USP is highly versatile: to achieve
universal prompting, USP categorizes a possible NLP task into one of the three
possible task types, and then uses a corresponding selector to select the most
suitable queries & zero-shot model-generated responses as
pseudo-demonstrations, thereby generalizing ICL to the zero-shot setup in a
fully automated way. We evaluate zero-shot USP with two PaLM models, and
demonstrate performances that are considerably stronger than standard zero-shot
baselines and are comparable to or even superior than few-shot baselines across
more than 20 natural language understanding (NLU) and natural language
generation (NLG) tasks.Comment: 10 pages, 3 figures, 4 tables (19 pages, 5 figures and 9 tables
including references and appendices
Surface Plasmon Enhanced Light Trapping in Metal/Silicon Nanobowl Arrays for Thin Film Photovoltaics
Enhancing the light absorption in thin film silicon solar cells with nanophotonic and plasmonic structures is important for the realization of high efficiency solar cells with significant cost reduction. In this work, we investigate periodic arrays of conformal metal/silicon nanobowl arrays (MSNBs) for light trapping applications in silicon solar cells. They exhibited excellent light-harvesting ability across a wide range of wavelengths up to infrared regimes. The optimized structure (MSNBsH) covered by SiO2 passivation layer and hemisphere Ag back reflection layer has a maximal short-circuit density (Jsc) 25.5 mA/cm2, which is about 88.8% higher than flat structure counterpart, and the light-conversion efficiency (η) is increased two times from 6.3% to 12.6%. The double-side textures offer a promising approach to high efficiency ultrathin silicon solar cells
Evolution of the strange-metal scattering in momentum space of electron-doped
The linear-in-temperature resistivity is one of the important mysteries in
the strange metal state of high-temperature cuprate superconductors. To uncover
this anomalous property, the energy-momentum-dependent imaginary part of the
self-energy Im holds the key information. Here we
perform systematic doping, momentum, and temperature-dependent angle-resolved
photoemission spectroscopy measurements of electron-doped cuprate and extract the evolution of the strange metal
scattering in momentum space. At low doping levels and low temperatures, Im
dependence dominates the whole momentum space. For
high doping levels and high temperatures, Im
shows up, starting from the antinodal region. By comparing with the hole-doped
cuprates and , we find a dichotomy of the scattering rate exists along the
nodal and antinodal direction, which is ubiquitous in the cuprate family. Our
work provides new insight into the strange metal state in cuprates
The role of cellular senescence in metabolic diseases and the potential for senotherapeutic interventions
Cellular senescence represents an irreversible state of cell cycle arrest induced by various stimuli strongly associated with aging and several chronic ailments. In recent years, studies have increasingly suggested that the accumulation of senescent cells is an important contributor to the decline of organ metabolism, ultimately resulting in metabolic diseases. Conversely, the elimination of senescent cells can alleviate or postpone the onset and progression of metabolic diseases. Thus, a close relationship between senescent cells and metabolic diseases is found, and targeting senescent cells has emerged as an alternative therapy for the treatment of metabolic diseases. In this review, we summarize the role of cellular senescence in metabolic diseases, explore relevant therapeutic strategies for metabolic diseases by removing senescent cells, and provide new insights into the treatment of metabolic diseases
Genome-Wide Identification and Expression Profiling of the TCP Family Genes in Spike and Grain Development of Wheat (Triticum aestivum L.)
The TCP family genes are plant-specific transcription factors and play important roles in plant development. TCPs have been evolutionarily and functionally studied in several plants. Although common wheat (Triticum aestivum L.) is a major staple crop worldwide, no systematic analysis of TCPs in this important crop has been conducted. Here, we performed a genome-wide survey in wheat and found 66 TCP genes that belonged to 22 homoeologous groups. We then mapped these genes on wheat chromosomes and found that several TCP genes were duplicated in wheat including the ortholog of the maize TEOSINTE BRANCHED 1. Expression study using both RT-PCR and in situ hybridization assay showed that most wheat TCP genes were expressed throughout development of young spike and immature seed. Cis-acting element survey along promoter regions suggests that subfunctionalization may have occurred for homoeologous genes. Moreover, protein–protein interaction experiments of three TCP proteins showed that they can form either homodimers or heterodimers. Finally, we characterized two TaTCP9 mutants from tetraploid wheat. Each of these two mutant lines contained a premature stop codon in the A subgenome homoeolog that was dominantly expressed over the B subgenome homoeolog. We observed that mutation caused increased spike and grain lengths. Together, our analysis of the wheat TCP gene family provides a start point for further functional study of these important transcription factors in wheat
Identification and Expression Profiling of the <i>Regulator of Chromosome Condensation 1 (RCC1)</i> Gene Family in <i>Gossypium Hirsutum</i> L. under Abiotic Stress and Hormone Treatments
The regulator of chromosome condensation 1 (RCC1) is the nucleotide exchange factor for a GTPase called the Ras-related nuclear protein, and it is important for nucleo-plasmic transport, mitosis, nuclear membrane assembly, and control of chromatin agglutination during the S phase of mitosis in animals. In plants, RCC1 molecules act mainly as regulating factors for a series of downstream genes during biological processes such as the ultraviolet-B radiation (UV-B) response and cold tolerance. In this study, 56 genes were identified in upland cotton by searching the associated reference genomes. The genes were found to be unevenly distributed on 26 chromosomes, except A06, A12, D03, and D12. Phylogenetic analysis by maximum-likelihood revealed that the genes were divided into five subgroups. The RCC1 genes within the same group shared similar exon/intron patterns and conserved motifs in their encoded proteins. Most genes of the RCC1 family are expressed differently under various hormone treatments and are negatively controlled by salt stress. Gh_A05G3028 and Gh_D10G2310, which encode two proteins located in the nucleus, were strongly induced under salt treatment, while mutants of their homoeologous gene (UVR8) in Arabidopsis and VIGS (virus induced gene silencing) lines of the two genes above in G. hirsutum exhibited a salt-sensitive phenotype indicating their potential role in salt resistance in cotton. These results provide valuable reference data for further study of RCC1 genes in cotton
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