3 research outputs found
Fixed-time Distributed Optimization under Time-Varying Communication Topology
This paper presents a method to solve distributed optimization problem within
a fixed time over a time-varying communication topology. Each agent in the
network can access its private objective function, while exchange of local
information is permitted between the neighbors. This study investigates first
nonlinear protocol for achieving distributed optimization for time-varying
communication topology within a fixed time independent of the initial
conditions. For the case when the global objective function is strictly convex,
a second-order Hessian based approach is developed for achieving fixed-time
convergence. In the special case of strongly convex global objective function,
it is shown that the requirement to transmit Hessians can be relaxed and an
equivalent first-order method is developed for achieving fixed-time convergence
to global optimum. Results are further extended to the case where the
underlying team objective function, possibly non-convex, satisfies only the
Polyak-\L ojasiewicz (PL) inequality, which is a relaxation of strong
convexity.Comment: 25 page
Exploiting Record Similarity for Practical Vertical Federated Learning
As the privacy of machine learning has drawn increasing attention, federated
learning is introduced to enable collaborative learning without revealing raw
data. Notably, \textit{vertical federated learning} (VFL), where parties share
the same set of samples but only hold partial features, has a wide range of
real-world applications. However, existing studies in VFL rarely study the
``record linkage'' process. They either design algorithms assuming the data
from different parties have been linked or use simple linkage methods like
exact-linkage or top1-linkage. These approaches are unsuitable for many
applications, such as the GPS location and noisy titles requiring fuzzy
matching. In this paper, we design a novel similarity-based VFL framework,
FedSim, which is suitable for more real-world applications and achieves higher
performance on traditional VFL tasks. Moreover, we theoretically analyze the
privacy risk caused by sharing similarities. Our experiments on three synthetic
datasets and five real-world datasets with various similarity metrics show that
FedSim consistently outperforms other state-of-the-art baselines