12,479 research outputs found
Correlation-induced resonances and population switching in a quantum dot coulomb valley
Strong correlation effects on electron transport through a spinless quantum
dot are considered. When two single-particle levels in the quantum dot are
degenerate, a conserved pseudospin degree of freedom appears for general
tunneling matrix elements between the quantum dot and leads. Local fluctuations
of the pseudospin in the quantum dot give rise to a pair of asymmetric
conductance peaks near the center of a Coulomb valley. An exact relation to the
population switching is provided.Comment: Fig. 4 and some technical details removed. To appear in PR
iSchools and Social Identity ??? A Social Network Analysis
We analyze the publication co-authorship network of an iSchool faculty community using ???Social Identity Theory??? as the theoretical lens. Initially, we discuss the need for a theoretical framework to analyze and interpret social network data. Then, we find out the patterns in the levels of interaction happening within the faculty community at an inter-group level. We grouped faculty members into different clusters according to several parameters such as their educational backgrounds, affiliations with research centers/labs, and h-indices. We based our analysis on this classification and we try to understand the relationship among social identity, group affiliation and academic collaborations. We conclude with the remarks that one could avoid idiosyncratic ways of interpreting social network data by using a proven theoretical lens like ???Social Identity Theory??
Gravity model explained by the radiation model on a population landscape
Understanding the mechanisms behind human mobility patterns is crucial to
improve our ability to optimize and predict traffic flows. Two representative
mobility models, i.e., radiation and gravity models, have been extensively
compared to each other against various empirical data sets, while their
fundamental relation is far from being fully understood. In order to study such
a relation, we first model the heterogeneous population landscape by generating
a fractal geometry of sites and then by assigning to each site a population
independently drawn from a power-law distribution. Then the radiation model on
this population landscape, which we call the radiation-on-landscape (RoL)
model, is compared to the gravity model to derive the distance exponent in the
gravity model in terms of the properties of the population landscape, which is
confirmed by the numerical simulations. Consequently, we provide a possible
explanation for the origin of the distance exponent in terms of the properties
of the heterogeneous population landscape, enabling us to better understand
mobility patterns constrained by the travel distance.Comment: 14 pages, 4 figure
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