47 research outputs found
A Game-theory Analysis of Charging Stations Selection by EV Drivers
We address the problem of Electric Vehicle (EV) drivers' assistance
through Intelligent Transportation System (ITS). Drivers of EVs that are low in battery may ask a navigation
service for advice on which charging station to use and which route
to take. A rational driver will follow the received advice, provided
there is no better choice
i.e., in
game-theory terms, if such advice corresponds to a Nash-equilibrium
strategy.
Thus, we model the problem as a game: first we propose a
congestion game, then a game with congestion-averse utilities,
both admitting at least
one pure-strategy Nash equilibrium. The
former represents a practical scenario with a high level of realism,
although at a high computational price. The latter neglects some
features of the real-world scenario but it exhibits very low
complexity, and is shown to provide results that, on average,
differ by 16% from those obtained with the former approach.
Furthermore, when drivers value the trip time most, the average
per-EV performance yielded by the Nash
equilibria and the one attained by solving a
centralized optimization problem that minimizes the EV trip time
differ by 15% at most.
This is an important result, as minimizing this quantity implies reduced road traffic congestion
and energy consumption, as well as higher user
satisfaction
Genome-wide activity of unliganded estrogen receptor-\u3b1\ua0 in breast cancer cells
Estrogen receptor-\u3b1 (ER\u3b1) has central role in hormone-dependent
breast cancer and its ligand-induced functions have been extensively
characterized. However, evidence exists that ER\u3b1 has functions that
are independent of ligands. In the present work, we investigated the
binding of ER\u3b1 to chromatin in the absence of ligands and its functions
on gene regulation. We demonstrated that in MCF7 breast cancer
cells unliganded ER\u3b1 binds to more than 4,000 chromatin sites.
Unexpectedly, although almost entirely comprised in the larger group
of estrogen-induced binding sites, we found that unliganded-ER\u3b1
binding is specifically linked to genes with developmental functions,
compared with estrogen-induced binding. Moreover, we found that
siRNA-mediated down-regulation of ER\u3b1 in absence of estrogen is
accompanied by changes in the expression levels of hundreds of
coding and noncoding RNAs. Down-regulatedmRNAs showed enrichment
in genes related to epithelial cell growth and development.
Stable ER\u3b1 down-regulation using shRNA, which caused cell growth
arrest, was accompanied by increased H3K27me3 at ER\u3b1 binding
sites. Finally, we found that FOXA1 and AP2\u3b3 binding to several sites
is decreased upon ER\u3b1 silencing, suggesting that unliganded ER\u3b1
participates, together with other factors, in the maintenance of the
luminal-specific cistrome in breast cancer cell
Towards a Realistic Optimization of Urban Traffic Flows
In spite of recent advances in Intelligent Transport, vehicular traffic dynamics are still hard to represent and analyze. Most of the previous work on traffic regards highways or single lanes where vehicles interact in one dimension. Models for multi-dimensional vehicle-to-vehicle interactions and models for urban intersections are quite complicated and hardly applicable on a large scale. Nonetheless, urban traffic jams are an actual problem that requires a solution. This paper proposes a method to optimize urban traffic layout using basic heuristics and computationally efficient simulations. Instead of modeling an entire urban map with hundreds of intersections, each typology of intersection is simulated in order to understand how it responds to different traffic patterns and intensities. This knowledge is leveraged to allow the computation of minimal delay route on the complete road map. In order to validate our model, we use the solution obtained with our heuristic to derive the average travel delay through simulation on realistic Manhattan topologies with different intersection types. \uc2\ua9 2012 IEEE
First passage time problems and related computational methods
Motivated by the interest of first passage time problems in neurobiology and in a variety of applied fields, we study the solution of first passage time equations for the Wiener and the Ornstein Uhlenbeck process both in the general case of time dependent threshold functions. Some computational results obtained by two different numerical methods are reported and briefly discussed