508 research outputs found
Phononic topological insulators with tunable pseudospin physics
Efficient control of phonons is crucial to energy-information technology, but
limited by the lacking of tunable degrees of freedom like charge or spin. Here
we suggest to utilize crystalline symmetry-protected pseudospins as new quantum
degrees of freedom to manipulate phonons. Remarkably, we reveal a duality
between phonon pseudospins and electron spins by presenting Kramers-like
degeneracy and pseudospin counterparts of spin-orbit coupling, which lays the
foundation for "pseudospin phononics". Furthermore, we report two types of
three-dimensional phononic topological insulators, which give topologically
protected, gapless surface states with linear and quadratic band degeneracies,
respectively. These topological surface states display unconventional phonon
transport behaviors attributed to the unique pseudospin-momentum locking, which
are useful for phononic circuits, transistors, antennas, etc. The emerging
pseudospin physics offers new opportunities to develop future phononics
Reciprocal Recommendation System for Online Dating
Online dating sites have become popular platforms for people to look for
potential romantic partners. Different from traditional user-item
recommendations where the goal is to match items (e.g., books, videos, etc)
with a user's interests, a recommendation system for online dating aims to
match people who are mutually interested in and likely to communicate with each
other. We introduce similarity measures that capture the unique features and
characteristics of the online dating network, for example, the interest
similarity between two users if they send messages to same users, and
attractiveness similarity if they receive messages from same users. A
reciprocal score that measures the compatibility between a user and each
potential dating candidate is computed and the recommendation list is generated
to include users with top scores. The performance of our proposed
recommendation system is evaluated on a real-world dataset from a major online
dating site in China. The results show that our recommendation algorithms
significantly outperform previously proposed approaches, and the collaborative
filtering-based algorithms achieve much better performance than content-based
algorithms in both precision and recall. Our results also reveal interesting
behavioral difference between male and female users when it comes to looking
for potential dates. In particular, males tend to be focused on their own
interest and oblivious towards their attractiveness to potential dates, while
females are more conscientious to their own attractiveness to the other side of
the line
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