284 research outputs found

    The Market Reaction to Stock Split Announcement and the Underlying Explanations

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    This paper examines the market reaction to stock splits announcements during the period 2003 to 2013. We find a significantly positive Cumulative Average Abnormal Return (CAAR) on the announcement day as well as the following day. Both liquidity and signaling reasons contribute to this result

    Covariant tensor formalism for partial wave analyses of ψΔΔˉ\psi \rightarrow\Delta\bar{\Delta}

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    The covariant tensor formulae for partial wave analysis of ψΔΔˉ\psi \rightarrow\Delta\bar{\Delta}, Δpπ±\Delta \to p \pi^\pm, Δˉpˉπ\bar{\Delta} \to \bar{p} \pi^\mp are derived, as well as the formulae for the decay sequence of ψNpˉ\psi \rightarrow N^* \bar{p}, NΔπN^* \to \Delta \pi^\mp, Δpπ±\Delta \to p \pi^\pm . These formulae are practical for the experiments measuring ψ\psi decaying into ppˉπ+πp \bar{p} \pi^+ \pi^- final states, such as BESIII with its recently collected huge J/ψJ/\psi and ψ(2S)\psi(2S) data samples.Comment: 10 page

    STUDY ON REINFORCEMENT OF FABRICATED HOLLOW SLAB BRIDGE BY POLYURETHANE-CEMENT COMPOSITE (PUC)

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    In this paper, a new polyurethane-cement composite (PUC) material is used to reinforce a 25-year hollow slab bridge. PUC material is composed of polyurethane and cement, which has good mechanical properties. After pouring PUC material at the bottom of the hollow slabs, the traffic can be restored in a short time. Ultimate bearing capacity was discussed based on the concrete structures. The failure mode of the reinforced beam depends on the PUC material. The strengthening process includes surface treatment of concrete, formwork erection and polyurethane cement pouring. In order to verify the effectiveness of PUC reinforced bridges, load tests were carried out before and after reinforcement. The test results showed that PUC could remove the bridge load and increase the stiffness of the hollow slabs

    Electron Bunch Train Excited Higher-Order Modes in a Superconducting RF Cavity

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    Higher-order mode (HOM) based intra-cavity beam diagnostics has been proved effectively and conveniently in superconducting radio-frequency (SRF) accelerators. Our recent research shows that the beam harmonics in the bunch train excited HOM spectrum, which have much higher signal-to-noise ratio than the intrinsic HOM peaks, may also be useful for beam diagnostics. In this paper, we will present our study on bunch train excited HOMs, including the theoretic model and recent experiments carried out based on the DC-SRF photoinjector and SRF linac at Peking University.Comment: Supported by National Natural Science Foundation of China (11275014

    Boosting Generalization with Adaptive Style Techniques for Fingerprint Liveness Detection

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    We introduce a high-performance fingerprint liveness feature extraction technique that secured first place in LivDet 2023 Fingerprint Representation Challenge. Additionally, we developed a practical fingerprint recognition system with 94.68% accuracy, earning second place in LivDet 2023 Liveness Detection in Action. By investigating various methods, particularly style transfer, we demonstrate improvements in accuracy and generalization when faced with limited training data. As a result, our approach achieved state-of-the-art performance in LivDet 2023 Challenges.Comment: 1st Place in LivDet2023 Fingerprint Representation Challeng

    Engendering the City: A Participatory Approach to Gender-Responsive Planning and Urban Design in Cairo

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    The city of Cairo has witnessed a considerable increase in crimes against women, compelling women to avoid or minimise their use of public spaces in recent years. The absence of consideration for women in city planning has made Egyptian women feel further excluded and threatened by the public space, in addition to the patriarchal social relations and religious conservatism. As part of the ‘gender-inclusive cities' research project, this study adopts a participatory approach as a tool for women's empowerment with the goal of promoting bottom-up models of planning, dissolving gendered norms, and improving women's status in a patriarchal society. The chapter provides an example of localised gender-inclusive design addressing women's spatial sensibilities and connecting them to the broader objectives of participation and emancipation. The findings of this study can help planners and policy makers co-create safer public spaces for local women, reduce spatial inequality, and facilitate their right to the city

    Long lead-time radar rainfall nowcasting method incorporating atmospheric conditions using long short-term memory networks

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    High-resolution radar rainfall data have great potential for rainfall predictions up to 6 h ahead (nowcasting); however, conventional extrapolation approaches based on in-built physical assumptions yield poor performance at longer lead times (3–6 h), which limits their operational utility. Moreover, atmospheric factors in radar estimate errors are often ignored. This study proposed a radar rainfall nowcasting method that attempts to achieve accurate nowcasting of 6 h using long short-term memory (LSTM) networks. Atmospheric conditions were considered to reduce radar estimate errors. To build radar nowcasting models based on LSTM networks (LSTM-RN), approximately 11 years of radar, gauge rainfall, and atmospheric data from the UK were obtained. Compared with the models built on optical flow (OF-RN) and random forest (RF-RN), LSTM-RN had the lowest root-mean-square errors (RMSE), highest correlation coefficients (COR), and mean bias errors closest to 0. Furthermore, LSTM-RN showed a growing advantage at longer lead times, with the RMSE decreasing by 17.99% and 7.17% compared with that of OF-RN and RF-RN, respectively. The results also revealed a strong relationship between LSTM-RN performance and weather conditions. This study provides an effective solution for nowcasting radar rainfall at long lead times, which enhances the forecast value and supports practical utility
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