More Like this

1. ARRU Phase Picker: Attention Recurrent-Residual U-Net for Picking Seismic P - and S -Phase Arrivals

   https://doi.org/10.1785/0220200382  

   Liao, Wu-Yu; Lee, En-Jui; Mu, Dawei; Chen, Po; Rau, Ruey-Juin (March 2021, Seismological Research Letters)

   null (Ed.)

   Abstract Seismograms are convolution results between seismic sources and the media that seismic waves propagate through, and, therefore, the primary observations for studying seismic source parameters and the Earth interior. The routine earthquake location and travel-time tomography rely on accurate seismic phase picks (e.g., P and S arrivals). As data increase, reliable automated seismic phase-picking methods are needed to analyze data and provide timely earthquake information. However, most traditional autopickers suffer from low signal-to-noise ratio and usually require additional efforts to tune hyperparameters for each case. In this study, we proposed a deep-learning approach that adapted soft attention gates (AGs) and recurrent-residual convolution units (RRCUs) into the backbone U-Net for seismic phase picking. The attention mechanism was implemented to suppress responses from waveforms irrelevant to seismic phases, and the cooperating RRCUs further enhanced temporal connections of seismograms at multiple scales. We used numerous earthquake recordings in Taiwan with diverse focal mechanisms, wide depth, and magnitude distributions, to train and test our model. Setting the picking errors within 0.1 s and predicted probability over 0.5, the AG with recurrent-residual convolution unit (ARRU) phase picker achieved the F1 score of 98.62% for P arrivals and 95.16% for S arrivals, and picking rates were 96.72% for P waves and 90.07% for S waves. The ARRU phase picker also shown a great generalization capability, when handling unseen data. When applied the model trained with Taiwan data to the southern California data, the ARRU phase picker shown no cognitive downgrade. Comparing with manual picks, the arrival times determined by the ARRU phase picker shown a higher consistency, which had been evaluated by a set of repeating earthquakes. The arrival picks with less human error could benefit studies, such as earthquake location and seismic tomography. 

   more » « less
2. Phase Transformations and Phase Segregation during Potassiation of Sn _x P _y Anodes

   https://doi.org/10.1021/acs.chemmater.2c01570  

   Ells, Andrew W.; Evans, Matthew L.; Groh, Matthias F.; Morris, Andrew J.; Marbella, Lauren E. (August 2022, Chemistry of Materials)
3. Phase-field modeling of Dictyostelium discoideum chemotaxis

   https://doi.org/10.1103/m323-63b6  

   Zhang, Yunsong; Levine, Herbert; Zhao, Yanxiang (September 2025, Physical Review E)
4. A K -Band Ultra-Wideband Binary Phase Shifter for Phase Modulating Applications in Radar

   https://doi.org/10.1109/LMWT.2022.3230039  

   Brown, Michael C.; Li, Changzhi (April 2023, IEEE Microwave and Wireless Technology Letters)
5. Critical metallic phase in the overdoped random t - J model

   https://doi.org/10.1073/pnas.2206921119  

   Christos, Maine; Joshi, Darshan G.; Sachdev, Subir; Tikhanovskaya, Maria (July 2022, Proceedings of the National Academy of Sciences)

   We investigate a model of electrons with random and all-to-all hopping and spin exchange interactions, with a constraint of no double occupancy. The model is studied in a Sachdev–Ye–Kitaev-like large-Mlimit with SU(M) spin symmetry. The saddle-point equations of this model are similar to approximate dynamic mean-field equations of realistic, nonrandom,t-Jmodels. We use numerical studies on both real and imaginary frequency axes, along with asymptotic analyses, to establish the existence of a critical non–Fermi-liquid metallic ground state at large doping, with the spin correlation exponent varying with doping. This critical solution possesses a time-reparameterization symmetry, akin to Sachdev–Ye–Kitaev (SYK) models, which contributes a linear-in-temperature resistivity over the full range of doping where the solution is present. It is therefore an attractive mean-field description of the overdoped region of cuprates, where experiments have observed a linear-Tresistivity in a broad region. The critical metal also displays a strong particle–hole asymmetry, which is relevant to Seebeck coefficient measurements. We show that the critical metal has an instability to a low-doping spin-glass phase and compute a critical doping value. We also describe the properties of this metallic spin-glass phase. 

   more » « less