Randomly shifted grids give binary features whose collision probability, and hence expected inner product, equals an eligible kernel. For separable multivariate kernels, independent one-dimensional grids multiply the collision probabilities across dimensions; averaging P independent partitions lowers variance. The appendix derives the pitch density p(delta)=delta k''(delta) for kernels expressible as convex mixtures of hat kernels. · CiteArk
Randomly shifted grids give binary features whose collision probability, and hence expected inner product, equals an eligible kernel. For separable multivariate kernels, independent one-dimensional grids multiply the collision probabilities across dimensions; averaging P independent partitions lowers variance. The appendix derives the pitch density p(delta)=delta k''(delta) for kernels expressible as convex mixtures of hat kernels.
来源：paper:PDF pp. 4-5, Section 4, Figure 2 and Algorithm 2; PDF p. 7, Appendix Lemma 1 and Eqs. (3)-(4)
