Approach to the application of ultrasonic technology to measuring physical properties of new building materials

739-746Non-metal ultrasonic testing analyzer could be used to measure the physical properities of new building materials. Taking a new subgrade material named municipal solid waste incineration bottom ash (MSWIBA) as an example, the feasibility that ultrasonic wave velocity was used to measure physical and mechanical properties of MSWIBA was analyzed according to studying the relationship between uniaxial compressive strength (σc), main differential stress peak value (σ1-σ3)max, cohesive force (c), internal friction angle (φ) and ultrasonic wave velocity. The feasibility that the Poisson's ratio computational formula of materials that owns cohesive force was analyzed whether it is suitable for use in MSWIBA. The dynamic elastic mechanics parameters were calculated based on elastic theory. The results show that there is a positive linear correlation relationship between σc, (σ1-σ3)max, c, φ, and ultrasonic wave velocity with the slope changing in a small scope. The Poisson's ratio computational formula of materials that owns cohesive force is suitable for MSWIBA, and the Poisson's ratio is 0.20~0.28 with dry density being 1.5 g/cm3 within 28 days . The dynamic modulus of elasticity (E) and dynamic shear modulus (G) increase with curing age increasing (E, G =Alnθ+B); however, the dynamic Poisson's ratio decreases with curing age increasing

Federated Few-shot Learning

Federated Learning (FL) enables multiple clients to collaboratively learn a machine learning model without exchanging their own local data. In this way, the server can exploit the computational power of all clients and train the model on a larger set of data samples among all clients. Although such a mechanism is proven to be effective in various fields, existing works generally assume that each client preserves sufficient data for training. In practice, however, certain clients may only contain a limited number of samples (i.e., few-shot samples). For example, the available photo data taken by a specific user with a new mobile device is relatively rare. In this scenario, existing FL efforts typically encounter a significant performance drop on these clients. Therefore, it is urgent to develop a few-shot model that can generalize to clients with limited data under the FL scenario. In this paper, we refer to this novel problem as \emph{federated few-shot learning}. Nevertheless, the problem remains challenging due to two major reasons: the global data variance among clients (i.e., the difference in data distributions among clients) and the local data insufficiency in each client (i.e., the lack of adequate local data for training). To overcome these two challenges, we propose a novel federated few-shot learning framework with two separately updated models and dedicated training strategies to reduce the adverse impact of global data variance and local data insufficiency. Extensive experiments on four prevalent datasets that cover news articles and images validate the effectiveness of our framework compared with the state-of-the-art baselines. Our code is provided\footnote{\href{https://github.com/SongW-SW/F2L}{https://github.com/SongW-SW/F2L}}.Comment: SIGKDD 202

LiveRetro: Visual Analytics for Strategic Retrospect in Livestream E-Commerce

Livestream e-commerce integrates live streaming and online shopping, allowing viewers to make purchases while watching. However, effective marketing strategies remain a challenge due to limited empirical research and subjective biases from the absence of quantitative data. Current tools fail to capture the interdependence between live performances and feedback. This study identified computational features, formulated design requirements, and developed LiveRetro, an interactive visual analytics system. It enables comprehensive retrospective analysis of livestream e-commerce for streamers, viewers, and merchandise. LiveRetro employs enhanced visualization and time-series forecasting models to align performance features and feedback, identifying influences at channel, merchandise, feature, and segment levels. Through case studies and expert interviews, the system provides deep insights into the relationship between live performance and streaming statistics, enabling efficient strategic analysis from multiple perspectives.Comment: Accepted by IEEE VIS 202

Medium Modifications and Production of Charmonia at LHC

A previously constructed transport approach to calculate the evolution of quarkonium yields and spectra in heavy-ion collisions is applied to Pb-Pb($\sqrt{s}$=2.76\,ATeV) collisions at the Large Hadron Collider (LHC). In this approach spectral properties of charmonia are constrained by euclidean correlators from thermal lattice QCD and subsequently implemented into a Boltzmann equation accounting for both suppression and regeneration reactions. Based on a fair description of SPS and RHIC data, we provide predictions for the centrality dependence of $J/\psi$ yields at LHC. The main uncertainty is associated with the input charm cross section, in particular its hitherto unknown reduction due to shadowing in nuclear collisions. Incomplete charm-quark thermalization and non-equilibrium in charmonium chemistry entail a marked reduction of the regeneration yield compared to the statistical equilibrium limit.Comment: 7 pages, 9 eps figure

Transverse Momentum Spectra of J/\psi in Heavy-Ion Collisions

We investigate J/\psi transverse-momentum (p_t) distributions and their centrality dependence in heavy-ion collisions at SPS and RHIC within the framework of a two-component model, which includes (i) primordial production coupled with various phases of dissociation, (ii) statistical coalescence of c and \bar{c} quarks at the hadronization transition. The suppression of the direct component (i) is calculated by solving a transport equation for J/\psi, \chi_c and \psi' in an expanding fireball using momentum dependent dissociation rates in the Quark-Gluon Plasma (QGP). The coalescence component is inferred from a kinetic rate equation with a momentum dependence following from a blast wave approach. At SPS energies, where the direct component dominates, the interplay of Cronin effect and QGP suppression results in fair agreement with NA50 p_t spectra. At RHIC energies, the p_t spectra in central Au+Au collisions are characterized by a transition from regeneration at low p_t to direct production above. At lower centralities, the latter dominates at all p_t.Comment: 7 pages, 6 figures; NA50 2000 data corrected in Fig.3 in v2; Implementation of leakage effect is corrected in v3, Numerical results for Cronin effect at RHIC are corrected in v

Using Near-real-time Monitoring of Landslide Deformation to Interpret Hydrological Triggers in Jiudian Gorge Reservoir

2182-2190 Near-real-time data with fine temporal resolution have been collected through using GPS from 105 to 130 m, and a Fast Moving Zone can be spatially identified from Main Deformation Zone, and the temporal evolution of the landslide consists of a progression in time with short periods of Fast Movement (FM) and longer periods of slower movement. The failure mode of landslide affected by rainfall is studied based on GPS monitoring data with PFC 2D being used to simulated the failure process of rain-induced landslide. Results indicate that three FMs can be identified from 105 to 130 m, and any rapid continuous drawdown of the reservoir water level from 130 to 105 m will definitely trigger FM. In addition, rapid continuous water rise tends to trigger FM from approximately 115 to 130 m while it will not trigger FMs unless there is a continuous drawdown phase before. Generally, there is a lag time between water level fluctuation and FMs

Complementary Ventilation Design Method for a Highway Twin-Tunnel Based on the Compensation Concept

Based on the compensation concept, an improved method for twin-tunnel complementary ventilation design considering differences in key pollutants in the uphill and downhill tunnels was proposed. The results demonstrate that the scheme developed using the improved method is more energy efficient when the energy consumption of the interchange channel is included. Here, a larger design of air volume is allocated to the uphill tunnel, and the admissible pollutant concentration for its exits. The complementary ventilation system of the Qingniling Tunnel, Dabieshan Tunnel, and Lianghekou Tunnel was redesigned for long-term performance using the improved method, and the resulting scheme was compared to that designed using the current method in terms of the total required air volume, interchange air volume, ventilation effects, and energy consumption. The results show that these factors in improved method are significantly smaller than that of the current method with an allowable reduction of ventilation effects. Moreover, the total airflow required in the Qingniling Tunnel was reduced from 889.31 to 796.74 m3/s, with a decrease rate of 10.4%; the interchange air volume was reduced from 203 to 175 m3/s, and the estimated energy consumption was decreased from 2760 to 2065.9 kW. This represents a 26% improvement in energy efficiency. The proposed method can provide a reference for the energy efficient design of ventilation systems in extra-long highway tunnels

Enhanced molten-pool boundary stability for microstructure control using quasi-continuous-wave laser additive manufacturing

The molten-pool boundary morphology and its stability play a key role in dendrite growth and solidification texture during laser additive manufacturing. In the present work, we have confirmed the advantages of quasi-continuous wave laser additive manufacturing (QCW-LAM) in enhancing the molten-pool boundary stability and promoting the continuously epitaxial growth of columnar dendrite. The influence of laser modes on the molten-pool boundary stability and solidification microstructure during laser additive manufacturing of Inconel 718 is investigated. Compared with the fluctuating molten-pool boundary of continuous-wave laser additive manufacturing (CW-LAM), the QCW-LAM is characterized by the high molten-pool boundary stability and the in-situ high-frequency remelting. These characteristics promote the continuously epitaxial growth of columnar dendrite and result in the directionally columnar structure. This work provides new insights into the control of the dendritic growth and solidification structure by improving the molten-pool boundary stability