44,170 research outputs found
What Does Stock Ownership Breadth Measure?
Using holdings data on a representative sample of all Shanghai Stock Exchange investors, we show that increases in ownership breadth (the fraction of market participants who own a stock) predict low returns: highest change quintile stocks underperform lowest quintile stocks by 23% per year. Small retail investors drive this result. Retail ownership breadth increases appear to be correlated with overpricing. Among institutional investors, however, the opposite holds: Stocks in the top decile of wealth-weighted institutional breadth change outperform the bottom decile by 8% per year, consistent with prior work that interprets breadth as a measure of short-sales constraints.
Next-to-leading order QCD predictions for pair production of neutral Higgs bosons at the CERN Large Hadron Collider
We present the calculations of the complete NLO inclusive total cross
sections for pair production of neutral Higgs bosons through
annihilation in the minimal supersymmetric standard model at the CERN Large
Hadron Collider. In our calculations, we used both the DREG scheme and the DRED
scheme and found that the NLO total cross sections in the above two schemes are
the same. Our results show that the -annihilation contributions can
exceed ones of fusion and annihilation for ,
and productions when is large. In the case of , the
NLO corrections enhance the LO total cross sections significantly, which can
reach a few tens percent, while for , the corrections are relatively
small, and are negative in most parameter space. Moreover, the NLO QCD
corrections can reduce the dependence of the total cross sections on the
renormalization/factorization scale, especially for . We also use the
CTEQ6.1 PDF sets to estimate the uncertainty of LO and NLO total cross
sections, and find that the uncertainty arising from the choice of PDFs
increases with the increasing .Comment: 43 pages, 16 figures, minor changes, some references added, a version
to appear in PR
Social Threat Framing on the Fundraising Performance: Evidence from Equity-based Crowdfunding Firms
In this study, we seek to investigate the impact of a firm’s social threat framing on its fundraising performance in equity-based crowdfunding. Crowdfunding ventures have growingly committed to social initiatives to attract investors. However, the success crucially depends on how much the investors value the prosocial cues presented in the proposal. Drawing on the perspective of threat framing, we argue that firms’ framing of social issues as a societal threat in their crowdfunding proposals promotes the fundraising performance. A social threat framing increases perceived importance of the firm’s business and sustainability initiatives in the eyes of investors by developing a sense of urgency and commitment towards the social issues. Using a sample of 229 U.S. equity crowdfunding firms from 2015 to 2021, we found a significant positive relationship between social threat framing and the fundraising performance. We also examined some conditional variables for such an effect, such as firm characteristics and the linguistic styles used in the crowdfunding proposals
The Impact of Social Threat Framing on Crowdfunding Performance: The Moderating Roles of Family Involvement and Linguistic Style
There has been increased use of social causes in crowdfunding proposals. Building on prior literature on issue framing in crowdfunding, we argue that framing of social threats, which integrates social framing and negative framing, can be particularly useful in attracting funding by creating a strong sense of urgency among investors. We find support for such a positive effect of social threat framing based on a sample of 217 U.S. equity crowdfunding firms from 2015 to 2021. Meanwhile, we find that social threat framing is more effective for family firms than nonfamily firms in improving crowdfunding performance, whereas local orientation presented in funding proposals does not show a significant effect. We also find that two styles of language - emotional expression and analytical thinking - present opposite moderation effects; the former strengthens the relationship, while the latter weakens it. The implications of the findings on crowdfunding success and effective communication are discussed
Next-to-Leading Order QCD Corrections to the Direct Top Quark Production via Model-independent FCNC Couplings at Hadron Colliders
We calculated the next-to-leading order (NLO) QCD corrections to the cross
sections for direct top quark productions induced by model--independent flavour
changing neutral current couplings at hadron colliders. The NLO results
increase the experimental sensitivity to the anomalous couplings. Our results
show that the NLO QCD corrections enhance the leading order (LO) total cross
sections at the Tevatron Run 2 about 60% for both of and
couplings, and enhance the LO total cross sections at the LHC
about 40% for couplings and 50% for couplings,
respectively. Moreover, the NLO QCD corrections vastly reduce the dependence of
the total cross sections on the renormalization or factorization scale, which
leads to increased confidence in predictions based on these results.Comment: 15 pages, 4 figures; published versio
Improvements in WRF simulation skills of southeastern United States summer rainfall: physical parameterization and horizontal resolution
Realistic regional climate simulations are important in understanding the mechanisms of summer rainfall in the southeastern United States (SE US) and in making seasonal predictions. In this study, skills of SE US summer rainfall simulation at a 15-km resolution are evaluated using the weather research and forecasting (WRF) model driven by climate forecast system reanalysis data. Influences of parameterization schemes and model resolution on the rainfall are investigated. It is shown that the WRF simulations for SE US summer rainfall are most sensitive to cumulus schemes, moderately sensitive to planetary boundary layer schemes, and less sensitive to microphysics schemes. Among five WRF cumulus schemes analyzed in this study, the Zhang-McFarlane scheme outperforms the other four. Further analysis suggests that the superior performance of the Zhang-McFarlane scheme is attributable primarily to its capability of representing rainfall-triggering processes over the SE US, especially the positive relationship between convective available potential energy and rainfall. In addition, simulated rainfall using the Zhang-McFarlane scheme at the 15-km resolution is compared with that at a 3-km convection-permitting resolution without cumulus scheme to test whether the increased horizontal resolution can further improve the SE US rainfall simulation. Results indicate that the simulations at the 3-km resolution do not show obvious advantages over those at the 15-km resolution with the Zhang-McFarlane scheme. In conclusion, our study suggests that in order to obtain a satisfactory simulation of SE US summer rainfall, choosing a cumulus scheme that can realistically represent the convective rainfall triggering mechanism may be more effective than solely increasing model resolution. © 2014 Springer-Verlag Berlin Heidelberg
The contact mechanics and occurrence of edge loading in modular metal-on-polyethylene total hip replacement during daily activities
The occurrence of edge loading in hip joint replacement has been associated with many factors such as prosthetic design, component malposition and activities of daily living. The present study aimed to quantify the occurrence of edge loading/contact at the articulating surface and to evaluate the effect of cup angles and edge loading on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR) during different daily activities. A three-dimensional finite element model was developed based on a modular MoP bearing system. Different cup inclination and anteversion angles were modelled and six daily activities were considered. The results showed that edge loading was predicted during normal walking, ascending and descending stairs activities under steep cup inclination conditions (≥55°) while no edge loading was observed during standing up, sitting down and knee bending activities. The duration of edge loading increased with increased cup inclination angles and was affected by the cup anteversion angles. Edge loading caused elevated contact pressure at the articulating surface and substantially increased equivalent plastic strain of the polyethylene liner. The present study suggested that correct positioning the component to avoid edge loading that may occur during daily activities is important for MoP THR in clinical practice
Floquet Chern Insulators of Light
Achieving topologically-protected robust transport in optical systems has
recently been of great interest. Most topological photonic structures can be
understood by solving the eigenvalue problem of Maxwell's equations for a
static linear system. Here, we extend topological phases into dynamically
driven nonlinear systems and achieve a Floquet Chern insulator of light in
nonlinear photonic crystals (PhCs). Specifically, we start by presenting the
Floquet eigenvalue problem in driven two-dimensional PhCs and show it is
necessarily non-Hermitian. We then define topological invariants associated
with Floquet bands using non-Hermitian topological band theory, and show that
topological band gaps with non-zero Chern number can be opened by breaking
time-reversal symmetry through the driving field. Furthermore, we show that
topological phase transitions between Floquet Chern insulators and normal
insulators occur at synthetic Weyl points in a three-dimensional parameter
space consisting of two momenta and the driving frequency. Finally, we
numerically demonstrate the existence of chiral edge states at the interfaces
between a Floquet Chern insulator and normal insulators, where the transport is
non-reciprocal and uni-directional. Our work paves the way to further exploring
topological phases in driven nonlinear optical systems and their optoelectronic
applications, and our method of inducing Floquet topological phases is also
applicable to other wave systems, such as phonons, excitons, and polaritons
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