activity
20242026
collaborators

6 papers

math.OC2026

Local-to-Global Exactness of SDP Relaxations for Sparse QCQPs

Masakazu Kojima, Sunyoung Kim, Naohiko Arima

We study exact semidefinite programming (SDP) relaxation for a given sparse quadratically constrained quadratic program (QCQP). The SDP relaxation is exact if, whenever it has an o…

math.OC2026

Exact SDP relaxations for a class of quadratic programs with finite and infinite quadratic constraints

Naohiko Arima, Sunyoung Kim, Masakazu Kojima

We investigate exact semidefinite programming (SDP) relaxations for the problem of minimizing a nonconvex quadratic objective function over a feasible region defined by both finite…

math.OC2026

Separable QCQPs and Their Exact SDP Relaxations

Masakazu Kojima, Sunyoung Kim, Naohiko Arima

This paper studies exact semidefinite programming relaxations (SDPRs) for separable quadratically constrained quadratic programs (QCQPs). We consider the construction of a larger s…

math.OC2025

Extending Exact Convex Relaxations of Quadratically Constrained Quadratic Programs

Masakazu Kojima, Sunyoung Kim, Naohiko Arima

A convex relaxation of a quadratically constrained quadratic program (QCQP) is called exact if it has a rank- optimal solution that corresponds to an optimal solution of the QCQ…

math.OC2025

Constructing QCQP Instances Equivalent to Their SDP Relaxations

Masakazu Kojima, Naohiko Arima, Sunyoung Kim

General quadratically constrained quadratic programs (QCQPs) are challenging to solve as they are known to be NP-hard. A popular approach to approximating QCQP solutions is to use…

math.OC2024

An Exceptionally Difficult Binary Quadratic Optimization Problem with Symmetry: a Challenge for The Largest Unsolved QAP Instance Tai256c

Koichi Fujii, Sunyoung Kim, Masakazu Kojima +2

Tai256c is the largest unsolved quadratic assignment problem (QAP) instance in QAPLIB. It is known that QAP tai256c can be converted into a 256 dimensional binary quadratic optimiz…