Probing dark matter particles at CEPC

We investigate the capability of the future electron collider CEPC in probing the parameter space of several dark matter models, including millicharged dark matter models, $Z'$ portal dark matter models, and effective field theory dark matter models. In our analysis, the monophoton final state is used as the primary channel to detect dark matter models at CEPC. To maximize the signal to background significance, we study the energy and angular distributions of the monophoton channel arising from dark matter models and from the standard model to design a set of detector cuts. For the $Z'$ portal dark matter, we also analyze the $Z'$ boson visible decay channel which is found to be complementary to the monophoton channel in certain parameter space. The CEPC reach in the parameter space of dark matter models is also put in comparison with Xenon1T. We find that CEPC has the unprecedented sensitivity to certain parameter space for the dark matter models considered; for example, CEPC can improve the limits on millicharge by one order of magnitude than previous collider experiments for ${\cal O}(1)-100$ GeV dark matter.Comment: 21 pages, 31 figure

Recommender Systems with Characterized Social Regularization

Social recommendation, which utilizes social relations to enhance recommender systems, has been gaining increasing attention recently with the rapid development of online social network. Existing social recommendation methods are based on the fact that users preference or decision is influenced by their social friends' behaviors. However, they assume that the influences of social relation are always the same, which violates the fact that users are likely to share preference on diverse products with different friends. In this paper, we present a novel CSR (short for Characterized Social Regularization) model by designing a universal regularization term for modeling variable social influence. Our proposed model can be applied to both explicit and implicit iteration. Extensive experiments on a real-world dataset demonstrate that CSR significantly outperforms state-of-the-art social recommendation methods.Comment: to appear in CIKM 201

An evaluation of behavioural activation treatment for anxiety (BATA) when delivered In-person and via videoconferencing

Cognitive Behavioural Therapy (CBT), a form of psychotherapy, is the most empirically supported treatment for anxiety, but new research into psychological treatments for anxiety is warranted because clinical improvement is not achieved by between 20% and 80% of the clinical population receiving CBT or other empirically supported psychological treatments. One recently developed approach is Behavioural Activation Therapy for Anxiety (BATA), first reported in 2009 by Turner and Leach who identified that Behavioural Activation (BA), though recognised as an effective treatment for depression, had rarely been applied to anxiety despite functional similarities. BATA has been written as a structured protocol, based on setting goals and scheduling activities, that brings clients into contact with naturally occurring sources of positive reinforcement for “clinically healthier”, socially-valid behaviours. This study included nine single case recipients of BATA ranging in age from 19 to 52 years old who met DSM-IV criteria for a non-trauma anxiety condition, assigned to one of three groups according to residence and type of delivery: Metropolitan In-Person, Metropolitan Videoconferencing, and Regional/Remote Videoconferencing. In each case, following a baseline period, BATA was applied in 12 weekly, 60-minute individual therapy sessions. Treatment outcomes were evaluated using A-B-C phase change analysis with repeated measures. Eight out of nine participants showed significant reduction in self-reported anxiety symptoms. A corresponding significant decrease in anxiety symptoms overall across all the participant groups was shown by an omnibus/global analysis, replicating the original Turner and Leach findings that featured an older group of participants. No differences were found between the Metropolitan and Regional/Remote groups or between the Metropolitan and Videoconferencing groups which provided evidence that BATA can be delivered as effectively by videoconferencing as when delivered face-to-face in-person