['Similar', 'numerical', 'oscillations', 'to', 'those', 'described', 'above', 'also', 'emerge', 'in', 'the', 'ISPM', 'when', 'utilising', 'classical', 'IBM', 'kernels', 'due', 'to', 'their', 'lack', 'of', 'regularity', '(', 'with', 'discontinuous', 'second', 'derivatives', ')', '.']