User profiles for Qiji Zhu

Qiji Jim Zhu

Western Michigan University
Verified email at wmich.edu
Cited by 2792

Exact penalization and necessary optimality conditions for generalized bilevel programming problems

JJ Ye, DL Zhu, QJ Zhu - SIAM Journal on optimization, 1997 - SIAM
The generalized bilevel programming problem (GBLP) is a bilevel mathematical program
where the lower level is a variational inequality. In this paper we prove that if the objective …

Pseudomathematics and financial charlatanism: The effects of backtest over fitting on out-of-sample performance

DH Bailey, JM Borwein, ML De Prado, QJ Zhu - Notices of the AMS, 2014 - ams.org
Qiji Jim Zhu is Professor of Mathematics at Western Michigan University. His email
address is zhu@wmich.edu. … Harvey, Liu, and Zhu [10] argue that there are hundreds of …

Nonsmooth analysis on smooth manifolds

Y Ledyaev, Q Zhu - Transactions of the American Mathematical Society, 2007 - ams.org
We study infinitesimal properties of nonsmooth (nondifferentiable) functions on smooth
manifolds. The eigenvalue function of a matrix on the manifold of symmetric matrices gives a …

The probability of backtest overfitting

…, J Borwein, M Lopez de Prado, QJ Zhu - … Finance (Risk Journals …, 2015 - papers.ssrn.com
Most firms and portfolio managers rely on backtests (or historical simulations of performance)
to select investment strategies and allocate them capital. Standard statistical techniques …

Trend following trading under a regime switching model

M Dai, Q Zhang, QJ Zhu - SIAM Journal on Financial Mathematics, 2010 - SIAM
This paper is concerned with the optimality of a trend following trading rule. The idea is to
catch a bull market at its early stage, ride the trend, and liquidate the position at the first …

[PDF][PDF] A survey of subdifferential calculus with applications

JM Borwein, QJ Zhu - Nonlinear Analysis-Series A Theory and …, 1999 - academia.edu
Nonsmooth analysis had its origins in the early 1970s when control theorists and nonlinear
programmers attempted to deal with necessary optimality conditions for problems with …

[PDF][PDF] On the solution set of differential inclusions in Banach space

QJ Zhu - Journal of differential equations, 1991 - core.ac.uk
Many problems in applied mathematics, such as those in control theory, mathematical
economics, and mechanics. lead to the study of differential inclusions. In a differential inclusion …

Hamiltonian necessary conditions for a multiobjective optimal control problem with endpoint constraints

QJ Zhu - SIAM Journal on Control and Optimization, 2000 - SIAM
This paper discusses Hamiltonian necessary conditions for a nonsmooth multiobjective
optimal control problem with endpoint constraints involving a general preference. The …

Implicit multifunction theorems

YS Ledyaev, QJ Zhu - Set-Valued Analysis, 1999 - Springer
We prove a general implicit function theorem for multifunctions with a metric estimate on the
implicit multifunction and a characterization of its coderivative. Traditional open covering …

An extended extremal principle with applications to multiobjective optimization

BS Mordukhovich, JS Treiman, QJ Zhu - SIAM Journal on Optimization, 2003 - SIAM
We develop an extended version of the extremal principle in variational analysis that can be
treated as a variational counterpart to the classical separation results in the case of …