1. Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia
2. Department of Marine Science, Faculty of Fishery and Marine Science, Universitas Padjadjaran, Sumedang 45363, Indonesia
3. Doctoral Program in Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia
4. Department of Production and Operations, Universiti Tun Hussein Onn Malaysia, Johor 86400, Malaysia