Ge Xia

Publications
Influence

J. Chen, Iyad A. Kanj, Ge Xia
Computer Science, Mathematics
Theor. Comput. Sci.
1 September 2010

This paper presents an O(1.2738^k+kn)-time polynomial-space algorithm for Vertex Cover improving the previous O( 1.286^k) time upper bound by Chen, Kanj, and Jia. Expand

The Stretch Factor of the Delaunay Triangulation Is Less than 1.998

Ge Xia
Mathematics, Computer Science
SIAM J. Comput.
22 March 2011

We show that the stretch factor of the Delaunay triangulation is less than $\rho = 1.998$, significantly improving the current best upper bound of 2.42 by Keil and Gutwin. Expand

Strong computational lower bounds via parameterized complexity

J. Chen, Xiuzhen Huang, Iyad A. Kanj, Ge Xia
Computer Science, Mathematics
J. Comput. Syst. Sci.
1 December 2006

We develop new techniques for deriving strong computational lower bounds for a class of well-known NP-hard problems in the above class. Expand

Parametric Duality and Kernelization: Lower Bounds and Upper Bounds on Kernel Size

J. Chen, H. Fernau, Iyad A. Kanj, Ge Xia
Mathematics, Computer Science
STACS
24 February 2005

We develop new techniques to derive lower bounds on the kernel size for certain parameterized problems. Expand

Improved Parameterized Upper Bounds for Vertex Cover

J. Chen, Iyad A. Kanj, Ge Xia
Mathematics, Computer Science
MFCS
28 August 2006

This paper presents an O(1.2738k + kn)-time polynomial-space parameterized algorithm for Vertex Cover improving the previous O(2kk2k+2) time upper bound by Chen, Kanj, and Jia. Expand

Seeing the trees and their branches in the network is hard

Iyad A. Kanj, L. Nakhleh, C. Than, Ge Xia
Computer Science, Mathematics
Theor. Comput. Sci.
1 July 2008

We prove that the problem of deciding whether a given tree is contained inside a network is NP-complete and provide a parameterized algorithm that runs in time O(2^k^/^2n^2). Expand

Linear FPT reductions and computational lower bounds

J. Chen, Xiuzhen Huang, Iyad A. Kanj, Ge Xia
Mathematics, Computer Science
STOC '04
13 June 2004

We develop new techniques for deriving very strong computational lower bounds for a class of well-known NP-hard problems, including weighted satisfiability, dominating set, hitting set, set cover, clique, and independent set. Expand

Tight lower bounds for certain parameterized NP-hard problems

J. Chen, B. Chor, +4 authors Ge Xia
Computer Science, Mathematics
Proceedings. 19th IEEE Annual Conference on…
15 September 2005

A group of parameterized NP-hard problems, including weighted SAT, dominating set, hitting set, set cover, and feature set, cannot be solved in time n/sup o(k)/poly(m), where n is the size of the universal set from which the k elements are to be selected and m is the instance size, unless the first level W[l] of the W-hierarchy collapses to FPT. Expand

Improved upper bound on the stretch factor of delaunay triangulations

Ge Xia
Mathematics, Computer Science
SoCG '11
13 June 2011

We prove that the stretch factor of the Delaunay triangulation of a set of points in the plane is less than ρ = 1.998, improving the previous best upper bound of 2.42. Expand

Tight Lower Bounds for Certain Parameterized NP-Hard Problems

J. Chen, B. Chor, +4 authors Ge Xia
Computer Science
Computational Complexity Conference
2004

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