In this paper, we determine the appropriate decay function for item-based collaborative filtering (CF). Instead of intuitive deduction, we introduce the Similarity-Signal-to-NoiseRatio (SSNR) to quantify the impacts of rated items on current recommendations. By measuring the variation of SSNR over time, drift in user interest is well visualized and quantified. Based on the trend changes of SSNR...

Collaborative filtering (CF) shares information between users to provide each with recommendations. Previous work suggests using sketching techniques to handle massive data sets in CF systems, but only allows testing whether users have a high proportion of items they have both ranked. We show how to determine the correlation between the rankings of two users, using concise “sketches” of the ran...

The Clifford algebra Cf of a binary form f of degree d is the kalgebra k{x, y}/I, where I is the ideal generated by {(αx + βy)d − f(α, β) | α, β ∈ k}. Cf has a natural homomorphic image Af that is a rank d2 Azumaya algebra over its center. We prove that the center is isomorphic to the coordinate ring of the complement of an explicit Θ-divisor in Picd+g−1 C/k , where C is the curve (wd − f(u, v)...

The first part of this paper is devoted to establish new rigidity results for proper holomorphic maps from the complex unit ball to higher rank bounded symmetric domains. The rigidity properties have been extensively studied in the past decades for proper holomorphic maps F : Ω1 → Ω2, between bounded symmetric domains Ω1,Ω2. The pioneer works are due to Poincaré [P] and later to Alexander [Al] ...

Collaborative filtering (CF) recommendation is a knowledge sharing technology for distribution of opinions and facilitating contacts in network society between people with similar interests. The main concerns of the CF algorithm are about prediction accuracy, speed of response time, problem of data sparsity, and scalability. In general the efforts of improving prediction algorithms and lessenin...

Contract farming (CF) is considered a relevant measure to tackle the challenges sustainable development from serious effects of climate change and COVID-19 pandemic. Despite positive CF, low participation frequent breaching contracts remain challenges. Several studies have mentioned advantages disadvantages CF but little known about their rankings perceptions involved stakeholders. To address t...

A subset S of a Riemannian manifoldN is called extrinsically homogeneous if S is an orbit of a subgroup of the isometry group of N . In [Th], Thorbergsson proved the remarkable result that every complete, connected, full, irreducible isoparametric submanifold of a finite dimensional Euclidean space of rank at least 3 is extrinsically homogeneous. This result, combined with results of [PT1] and ...

Introduction: The Coronavirus has crossed geographical borders. This study was performed to rank and cluster Iranian provinces based on coronavirus disease (COVID-19) recorded cases from February 19 to March 22, 2020. Materials and Methods: This cross-sectional study was conducted in 31 provinces of Iran using the daily number of confirmed cases. Cumulative Frequency (CF) and Adjusted CF (ACF)...

We consider fingerprinting methods for collaborative filtering (CF) systems. In general, CF systems show their real strength when supplied with enormous data sets. Earlier work already suggests sketching techniques to handle massive amounts of information, but most prior analysis has so far been limited to non-ranking application scenarios and has focused mainly on a theoretical analysis. We de...