In briefMinimum subpacketization of Reed-Solomon codes for cut-set-optimal linear repair
SummaryThis paper studies the smallest subpacketization of Reed-Solomon codes that allow exact linear repair of every coordinate from any d helpers while meeting the cut-set bound. It proves a lower bound of sG_s(d+1) and shows it equals sG_s(n) when d(d+2) ≥ 4(n+1). The paper also gives a finite formula for G_s(n), an asymptotic growth result, and an affine-plane example showing sG_s(n) is not universal, along with a conjecture.
WhyProves tight minimum subpacketization for RS codes under a degree condition, with rigorous proofs, impacting distributed storage coding theory.
In briefAdapting hybrid LLM inference to each request for greater efficiency
SummaryThis paper presents Morph, a serving system that co-designs model architecture and runtime so hybrid language models can choose their layer layout per request. Each block pairs Attention and state space model layers, and a prefill-stage gate selects a layout that stays fixed during decoding. Experiments on six datasets report a better quality-efficiency trade-off than static hybrid baselines, with serving throughput improved by up to 3.87x and substantially lower inference latency.
In briefPrivacy-preserving over-the-air federated learning in cell-free massive MIMO with user-centric clustering
SummaryThis paper studies a cross-layer design for differentially private federated learning over cell-free massive MIMO networks, where user model updates are aggregated over the air. It shows that thermal noise in wireless reception can help mask private information, reducing or removing the need for artificial noise. The authors jointly optimize access point-user associations, transmit powers, and artificial noise variances to minimize aggregation variance under per-user privacy constraints. Simulations report up to 89% lower aggregation variance than baselines and 97% test accuracy on MNIST, with consistent gains on CIFAR-10.
In briefCapacity of private information retrieval from coded storage with colluding, robust and Byzantine servers
SummaryThis paper studies private information retrieval from MDS-coded databases that include T colluding servers, U robust servers, and B Byzantine servers. The authors characterize the capacity for linear, full support-rank schemes and show the same expression holds without those restrictions when K=1 or T=1. They also extend the construction to retrieving P out of M files, and report that for P≥M/2 with K=1 or T=1 the multi-file scheme achieves capacity.
In briefUniqueness of codes for 4-cell connected disjoint clusters in the spatial chromatic model
SummaryThis paper studies the coding of the spatial chromatic model (SCM), an entity-oriented spatial data model in which each cell has a chromatic code. Earlier work had shown uniqueness for 2-cell and 3-cell connected disjoint clusters. Building on that, the authors prove that the chromatic codes of 4-cell connected disjoint clusters are unique.
