Institution: | a Mathematics, School of Engineering and Science, Victoria University, P.O. Box 14428, Melbourne City, MC 8001, Australia b School of Computational and Applied Mathematics, University of the Witwatersrand, Private Bag-3, Wits-2050, Johannesburg, South Africa c Department of Mathematical Education and the RINS, Gyeongsang National University, Chinju 660-701, Republic of Korea d Department of Mathematics, Dongeui University, Busan 614-714, Republic of Korea |