Valley-dependent gauge fields for ultracold atoms in square optical superlattices

We propose an experimental scheme to realize the valley-dependent gauge fields for ultracold fermionic atoms trapped in a state-dependent square optical lattice. Our scheme relies on two sets of Raman laser beams to engineer the hopping between adjacent sites populated by two-component fermionic atoms. One set of Raman beams are used to realize a staggered \pi-flux lattice, where low energy atoms near two inequivalent Dirac points should be described by the Dirac equation for spin-1/2 particles. Another set of laser beams with proper Rabi frequencies are added to further modulate the atomic hopping parameters. The hopping modulation will give rise to effective gauge potentials with opposite signs near the two valleys, mimicking the interesting strain-induced pseudo-gauge fields in graphene. The proposed valley-dependent gauge fields are tunable and provide a new route to realize quantum valley Hall effects and atomic valleytronics.Comment: 5+ pages, 2 figures; language polished, references and discussions added; accepted by PR

Distance-aware Attention Reshaping: Enhance Generalization of Neural Solver for Large-scale Vehicle Routing Problems

Neural solvers based on attention mechanism have demonstrated remarkable effectiveness in solving vehicle routing problems. However, in the generalization process from small scale to large scale, we find a phenomenon of the dispersion of attention scores in existing neural solvers, which leads to poor performance. To address this issue, this paper proposes a distance-aware attention reshaping method, assisting neural solvers in solving large-scale vehicle routing problems. Specifically, without the need for additional training, we utilize the Euclidean distance information between current nodes to adjust attention scores. This enables a neural solver trained on small-scale instances to make rational choices when solving a large-scale problem. Experimental results show that the proposed method significantly outperforms existing state-of-the-art neural solvers on the large-scale CVRPLib dataset

Electronic Shore Power Station Based on Matrix-style Frequency Algorithm

AbstractThe current port power supply to foreign ships, there are two ways power-type for owned diesel-powered and frequency conversion unit,In this paper,Proposed electronic shore power station, put forward electronic shore power station's concepts, and gives a whole building program of electronic shore power station based on matrix conversion algorithm, It will change 10kV/50Hz (35Kv/50Hz) input voltage into 440V/60Hz low-voltage, not only eliminating intermediate links, but also simplify the hardware circuit and reduce the production cost and improve the competitiveness of enterprises. Simulation and experimental results show that this program has a built shore power station of high power factor, sinusoidal effective, low distortion, environmental pollution and the advantages,It will be very definite practical significance

Laparoscopic versus open distal pancreatectomy: A meta-analysis

SummaryObjectiveLaparoscopic distal pancreatectomy (LDP) is a minimally invasive surgical technique. The aim of the present study was to evaluate the currently available literature and compare the short-term clinical outcomes of patients who underwent LDP for left-sided pancreatic pathology with patients who underwent traditional open surgery.MethodsA literature search was performed to identify and compare studies that reported the clinical outcomes of both LDP and open distal pancreatectomy (ODP). Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using either fixed-effects or random-effects models.ResultsNineteen nonrandomized controlled studies were identified that matched the selection criteria and reported the clinical outcomes of 1935 patients, of whom 805 underwent LDP and 1130 underwent ODP. Compared with open surgery, reports on laparoscopic resection indicate potentially favorable outcomes in terms of operative blood loss (WMD: -273.11; 95% CI: -404.61 to -141.61), the requirement of a blood transfusion (OR: 0.28; 95% CI: 0.11–0.71), postoperative time until oral intake (WMD: -1.19; 95% CI: -1.87 to -0.50), time to first flatus (WMD: -1.03, 95% CI: -1.93 to -0.12), length of hospital stay (WMD: -3.87, 95% CI: -5.06 to -2.68), and overall morbidity (OR: 0.70, 95% CI: 0.56–0.87). There were no differences in terms of the extent of oncologic clearance and postoperative mortality.ConclusionLDP results in a faster postoperative recovery and a comparable oncologic clearance in comparison with open surgery. Additional large trials are required to delineate the long-term clinical outcomes of patients diagnosed with malignant neoplasms who undergo either of these two surgeries

Crossing Reliability of Electric Bike Riders at Urban Intersections

This paper presents a crossing reliability model of electric bike riders at urban intersections using survival analysis approach. Riders’ crossing behavior was collected by video cameras. Waiting times in the red-light phase were modeled by reliability-based model that recognizes the covariate effects. Three parametric models by the exponential, Weibull, and log-logistic distributions were proposed to analyze when and why electric bike riders cross against the red light. The results indicate that movement information and situation factors have significant effects on riders’ crossing reliability. The findings of this paper provide an important demonstration of method and an empirical basis to assess crossing reliability of electric bike riders at the intersection