There could be many ways to define the weights, but for now we use the following definition from (Zhu et al., 2003), where σ 2 is a hyper-parameter 2 : To assess the similarity between locations, we measure the cosine similarity between vectors of their co-occurrence frequencies with activities.
let matrix We use the same value σ 2 = 0.03 as (Zhu et al., 2003).