East-West Journal of Mathematics

Honorary Editors:

DINH VAN HUYNH

Ohio University, Athens,

OH 45700, USA

SOMPONG DHOMPONGSA

Chiang Mai University,

Chiang Mai 50200, Thailand

Executive Editors:

TARIQ RIZVI

The Ohio State University

Lima, OH 45804, USA

NGUYEN VAN SANH

Mahidol University

Bangkok 10400, Thailand

Managing Editor:

NITTIYA PABHAPOTE

University of the Thai Chamber of Commerce

Bangkok, Thailand

ISSN: 1513-489X