activity
20132026
most citedS-Lemma with Equality and Its Applications

62 citations · 124 across the 15 of their papers we have counts for

collaborators

15 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★ 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.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…

math.OC2020

Deciding whether two quadratic surfaces actually intersect

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

We answer an open question proposed by Pólik and Terlaky in 2007 that: {\it how we can decide whether two quadratic surfaces intersect without actually computing the intersections?…

math.OC2020

Arrangement of level sets of quadratic constraints and its relation to nonconvex quadratic optimization problems

Huu-Quang Nguyen, Ruey-Lin Sheu

We study a special class of non-convex quadratic programs subject to two (possibly indefinite) quadratic constraints when the level sets of the constraint functions are {\it not} a…

math.OC2020

Simultaneous diagonalization via congruence of real symmetric matrices and its implications in optimization

Thi-Ngan Nguyen, Van-Bong Nguyen, Thanh-Hieu Le +1

Let be a collection of real symmetric matrices. The objective of the paper is to offer an algorithm that finds a common congruence ma…

math.OC2014

Double Well Potential Function and Its Optimization in The n-dimensional Real Space -- Part I

Shu-Cherng Fang, David Yang Gao, Gang-Xuan Lin +2

A special type of multi-variate polynomial of degree 4, called the double well potential function, is studied. When the function is bounded from below, it has a very unique propert…

math.OC2014★ 17 cited

On the p-regularized trust region subproblem

Yong Hsia, Ruey-Lin Sheu, Ya-xiang Yuan

The -regularized subproblem (p-RS) is a regularisation technique in computing a Newton-like step for unconstrained optimization, which globally minimizes a local quadratic appro…

math.OC2014★ 1 cited

Double Well Potential Function and Its Optimization in the n-dimensional Real Space - Part II

Yong Xia, Ruey-Lin Sheu, Shu-Cherng Fang +1

In contrast to taking the dual approach for finding a global minimum solution of a double well potential function, in Part II of the paper, we characterize a local minimizer, local…

math.OC2014★ 62 cited

S-Lemma with Equality and Its Applications

Yong Xia, Shu Wang, Ruey-Lin Sheu

Let and be two quadratic functions having symmetric matrices and . The S-lemma with equality asks when the unsolvability of the sys…

math.OC2014★ 4 cited

An SDP Approach For Solving Quadratic Fractional Programming Problems

Van-Bong Nguyen, Ruey-Lin Sheu, Yong Xia

This paper considers a fractional programming problem (P) which minimizes a ratio of quadratic functions subject to a two-sided quadratic constraint. As is well-known, the fraction…

cs.IT2013

On RIC bounds of Compressed Sensing Matrices for Approximating Sparse Solutions Using Quasi Norms

Yong Hsia, Ruey-Lin Sheu

This paper follows the recent discussion on the sparse solution recovery with quasi-norms when the sensing matrix possesses a Restricted Isometry Constant $δ_{2…

math.OC2013★ 17 cited

A Revisit to Quadratic Programming with One Inequality Quadratic Constraint via Matrix Pencil

Yong Hsia, Gang-Xuan Lin, Ruey-Lin Sheu

The quadratic programming over one inequality quadratic constraint (QP1QC) is a very special case of quadratically constrained quadratic programming (QCQP) and attracted much atten…

math.OC2013★ 19 cited

Trust Region Subproblem with a Fixed Number of Additional Linear Inequality Constraints has Polynomial Complexity

Yong Hsia, Ruey-Lin Sheu

The trust region subproblem with a fixed number m additional linear inequality constraints, denoted by (Tm), have drawn much attention recently. The question as to whether Problem…