Can the Query-based Object Detector Be Designed with Fewer Stages?

Query-based object detectors have made significant advancements since the publication of DETR. However, most existing methods still rely on multi-stage encoders and decoders, or a combination of both. Despite achieving high accuracy, the multi-stage paradigm (typically consisting of 6 stages) suffers from issues such as heavy computational burden, prompting us to reconsider its necessity. In this paper, we explore multiple techniques to enhance query-based detectors and, based on these findings, propose a novel model called GOLO (Global Once and Local Once), which follows a two-stage decoding paradigm. Compared to other mainstream query-based models with multi-stage decoders, our model employs fewer decoder stages while still achieving considerable performance. Experimental results on the COCO dataset demonstrate the effectiveness of our approach

Numerical Solutions to the Robin Inverse Problem With Nonnegativity Constraints

We present iterative numerical methods for solving the inverse problem of recovering the nonnegative Robin coefficient from partial boundary measurement of the solution to the Laplace equation. Based on the boundary integral equation formulation of the problem, nonnegativity constraints in the form of a penalty term are incorporated conveniently into least-squares iteration schemes for solving the inverse problem. Numerical implementation and examples are presented to illustrate the effectiveness of this strategy in improving recovery results

Fast Algorithms for Boundary Integral Equations on Elliptic Domains and Related Inverse Problems

Fast algorithms for boundary integral equations connected with Robin boundary value problem for the Laplace equation in domains with ellipse or close to ellipse boundaries are developed. It is shown that the coefficient matrices of discretisation systems have a special structure. This fact is used to develop a fast algorithm for matrix vector multiplication and to implement it in the numerical methods used. Such an approach is especially helpful in numerical methods for inverse problems, since many methods of their solution repeatedly use forward solvers. The efficiency of the methods is illustrated by numerical examples