activity
20202026
most citedOn the convexity for the range set of two quadratic functions

4 citations · 4 across the 8 of their papers we have counts for

collaborators

8 papers

math.OC2026

Last two pieces of the puzzle for unsolvability of a system of two quadratic (in)equalities

Min-Chi Wang, Ruey-Lin Sheu, Huu-Quang Nguyen

Given two quadratic functions \( f(x) = x^T Ax + 2a^T x + a_0 \) and \( g(x) = x^T Bx + 2b^T x + b_0 ,\) each associated with either the strict inequality (); non-strict inequa…

math.OC2025

The Joint Range of Quadratic Mapping on Hilbert Space

Huu-Quang Nguyen

We present a novel technical method for analyzing the hidden convex structure embedded in the joint range of a quadratic mapping defined on a Hilbert space. Our approach stands out…

math.OC2025★ 4 cited

On the convexity for the range set of two quadratic functions

Huu-Quang Nguyen, Ya-Chi Chu, Ruey-Lin Sheu

Given symmetric matrices and , Dines in 1941 proved that the joint range set is always convex. Our paper is concerned with…

math.OC2025

A new separable property of the joint numerical range of quadratic functions and its applications to the Smallest Enclosing Ball Problem

Van-Bong Nguyen, Huu-Quang Nguyen

We explore separable property of the joint numerical range of a special class of quadratic functions and apply it to solving the smallest enclosing ball (SEB) problem…

math.OC2021

On Separation of level sets for a pair of quadratic functions

Huu-Quang Nguyen, Ya-Chi Chu, Ruey-Lin Sheu

Given a quadratic function it is possible that its level set has two connected components and thus can be separated by the le…

math.OC2020

Solving a new type of quadratic optimization problem having a joint numerical range constraint

Huu-Quang Nguyen, Ruey-Lin Sheu, Yong Xia

We propose a new formulation of quadratic optimization problems. The objective function is given as composition of a quadratic function with two -variate q…