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A<sc>bstract</sc> Large-momentum effective theory (LaMET) provides an approach to directly calculate thex-dependence of generalized parton distributions (GPDs) on a Euclidean lattice through power expansion and a perturbative matching. When a parton’s momentum becomes soft, the corresponding logarithms in the matching kernel become non-negligible at higher orders of perturbation theory, which requires a resummation. But the resummation for the off-forward matrix elements at nonzero skewnessξis difficult due to their multi-scale nature. In this work, we demonstrate that these logarithms are important only in the threshold limit, and derive the threshold factorization formula for the quasi-GPDs in LaMET. We then propose an approach to resum all the large logarithms based on the threshold factorization, which is implemented on a GPD model. We demonstrate that the LaMET prediction is reliable for [−1 +x₀,−ξ−x₀] ∪ [−ξ+x₀, ξ−x₀] ∪ [ξ+x₀,1 −x₀], wherex₀is a cutoff depending on hard parton momenta. Through our numerical tests with the GPD model, we demonstrate that our method is self-consistent and that the inverse matching does not spread the nonperturbative effects or power corrections to the perturbatively calculable regions. 

Neural Radiance Field (NeRF) has emerged as a powerful technique for 3D scene representation due to its high rendering quality. Among its applications, mobile NeRF video-on-demand (VoD) is especially promising, beneting from both the scalability of the mobile devices and the immersive experience oered by NeRF. However, streaming NeRF videos over real-world networks presents signi cant challenges, particularly due to limited bandwidth and temporal dynamics. To address these challenges, we propose NeRFlow, a novel framework that enables adaptive streaming for NeRF videos through both bitrate and viewpoint adaptation. NeRFlow solves three fundamental problems: rst, it employs a rendering-adaptive pruning technique to determine voxel importance, selectively reducing data size without sacricing rendering quality. Second, it introduces a viewpoint-aware adaptation module that eciently compensates for uncovered regions in real time by combining preencoded master and sub-frames. Third, it incorporates a QoE-aware bitrate ladder generation framework, leveraging a genetic algorithm to optimize the number and conguration of bitrates while accounting for bandwidth dynamics and ABR algorithms. Through extensive experiments, NeRFlow is demonstrated to eectively improve user Quality of Experience (QoE) by 31.3% to 41.2%, making it an ecient solution for NeRF video streaming. 

Abstract Synoptic eddies embedded in a westerly flow undergo downstream developments due to their dispersive nature. This paper examines the finite-amplitude aspects of downstream development with the budget of local wave activity (LWA), including explicit contributions from diabatic heating. LWA captures well individual troughs/ridges and the wave packet, and its column budget affords simplified interpretations. In the LWA framework, (linear) downstream development demonstrated in previous analyses is represented by the LWA advection by the zonal reference flow plus LWA flux induced by the radiation of Rossby waves. In addition, convergence of nonlinear advective LWA flux, baroclinic sources at the lower boundary, meridional redistribution by eddy momentum flux, and diabatic sources and sinks complete the column budget of LWA. When applied to the life cycles of troughs within coherent wave packets in the Southern Hemisphere, the LWA budget reveals that individual troughs grow mainly through downstream development, convergence of nonlinear advective flux by eddies, and diabatic heating. Downstream development and divergence of nonlinear flux also dominate trough decay. Contributions from nonlinear advective eddy flux are large in the presence of a strong ridge either immediately upstream or downstream of the trough. Furthermore, anticyclonic components of advective LWA fluxes associated with the upstream or downstream ridge transfer LWA into or out of the trough. Diabatic contributions are significant when the heating exhibits a tilted vertical structure that gives rise to enhanced vertical gradient in heating.