Vietnam Journal
of
MATHEMATICS

Volume 27, Number 4, 1999


27

Normal Sets, Polyblocks, and Monotonic Optimization
Hoang tuy

277

28

The Bundle Structure of Non-Commutative Tori
Sei-Qwon Oh and Chun-Gil Park

301

29

Persistence in a Model of Predator-Prey Population Dynamics with the Action of a Parasite in Periodic Environment
Trinh Tuan Anh and Tran Van Nhung

309

30

Outer γ-Convexity in Normed Linear Spaces

Hoang Xuan Phu and Phan Thanh An

323

31

Non-Existence of Homoclinic Orbits and Global Asymptotic Stability of FitzHugh-Nagumo System
Makoto Hayashi

335

32

Slenderness of Rings
B. J. Gardner

345

33

On Asymptotic Orders of n-Term Approximations and Nonlinear n-Widths
Dinh Dung

363

34

On Stability of Systems of Linear Differential Equations on l∞-Space

Tran Thi Loan

369

35

Stability of Non-Linear Discrete Time-Varying Retarded Systems

Nguyen Sinh Bay and Vu Ngoc Phat

373

36

Stability Radii of Linear Differential Algebraic Equations

Nguyen Huu Du

379