2,178 research outputs found
User Attraction via Wireless Charging in Cellular Networks
A strong motivation of charging depleted battery can be an enabler for
network capacity increase. In this light we propose a spatial attraction
cellular network (SAN) consisting of macro cells overlaid with small cell base
stations that wirelessly charge user batteries. Such a network makes battery
depleting users move toward the vicinity of small cell base stations. With a
fine adjustment of charging power, this user spatial attraction (SA) improves
in spectral efficiency as well as load balancing. We jointly optimize both
enhancements thanks to SA, and derive the corresponding optimal charging power
in a closed form by using a stochastic geometric approach.Comment: to be presented in IEEE International Symposium on Modeling and
Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt) Workshop on
Green Networks (GREENNET) 2016, Arizona, USA (8 pages, 4 figures
Generalized gravity model for human migration
The gravity model (GM) analogous to Newton's law of universal gravitation has
successfully described the flow between different spatial regions, such as
human migration, traffic flows, international economic trades, etc. This simple
but powerful approach relies only on the 'mass' factor represented by the scale
of the regions and the 'geometrical' factor represented by the geographical
distance. However, when the population has a subpopulation structure
distinguished by different attributes, the estimation of the flow solely from
the coarse-grained geographical factors in the GM causes the loss of
differential geographical information for each attribute. To exploit the full
information contained in the geographical information of subpopulation
structure, we generalize the GM for population flow by explicitly harnessing
the subpopulation properties characterized by both attributes and geography. As
a concrete example, we examine the marriage patterns between the bride and the
groom clans of Korea in the past. By exploiting more refined geographical and
clan information, our generalized GM properly describes the real data, a part
of which could not be explained by the conventional GM. Therefore, we would
like to emphasize the necessity of using our generalized version of the GM,
when the information on such nongeographical subpopulation structures is
available.Comment: 14 pages, 6 figures, 2 table
Recommended from our members
Mid-Holocene Northern Hemisphere warming driven by Arctic amplification.
The Holocene thermal maximum was characterized by strong summer solar heating that substantially increased the summertime temperature relative to preindustrial climate. However, the summer warming was compensated by weaker winter insolation, and the annual mean temperature of the Holocene thermal maximum remains ambiguous. Using multimodel mid-Holocene simulations, we show that the annual mean Northern Hemisphere temperature is strongly correlated with the degree of Arctic amplification and sea ice loss. Additional model experiments show that the summer Arctic sea ice loss persists into winter and increases the mid- and high-latitude temperatures. These results are evaluated against four proxy datasets to verify that the annual mean northern high-latitude temperature during the mid-Holocene was warmer than the preindustrial climate, because of the seasonally rectified temperature increase driven by the Arctic amplification. This study offers a resolution to the "Holocene temperature conundrum", a well-known discrepancy between paleo-proxies and climate model simulations of Holocene thermal maximum
DeeLeMa: Missing information search with Deep Learning for Mass estimation
We present DeeLeMa, a deep learning network to analyze energies and momenta
in particle collisions at high energy colliders, especially DeeLeMa is
constructed based on symmetric event topology, and the generated mass
distributions show robust peaks at the physical masses after the combinatoric
uncertainties, and detector smearing effects are taken into account. DeeLeMa
can be widely used in different event topologies by adopting the corresponding
kinematic symmetries
The impact of Arctic sea ice loss on mid-Holocene climate.
Mid-Holocene climate was characterized by strong summer solar heating that decreased Arctic sea ice cover. Motivated by recent studies identifying Arctic sea ice loss as a key driver of future climate change, we separate the influences of Arctic sea ice loss on mid-Holocene climate. By performing idealized climate model perturbation experiments, we show that Arctic sea ice loss causes zonally asymmetric surface temperature responses especially in winter: sea ice loss warms North America and the North Pacific, which would otherwise be much colder due to weaker winter insolation. In contrast, over East Asia, sea ice loss slightly decreases the temperature in early winter. These temperature responses are associated with the weakening of mid-high latitude westerlies and polar stratospheric warming. Sea ice loss also weakens the Atlantic meridional overturning circulation, although this weakening signal diminishes after 150-200 years of model integration. These results suggest that mid-Holocene climate changes should be interpreted in terms of both Arctic sea ice cover and insolation forcing
Timing information at HL-LHC: Complete determination of masses of Dark Matter and Long lived particle
A long standing problem in kinematics at the hadron colliders is to determine
the mass of invisible particles. This issue is particularly important for the
signals of dark matter, which becomes one of the prominent targets of future
collider experiments. In this paper, we show that the additional information
from the precise timing measurement, which will be available at the planned
high-liminosity run of the LHC (HL-LHC), will shade new light on the kinematics
study. As a concrete example, we focus on the signal of the pair produced
long-lived particles (), respectively leaving displaced vertex with
visible () and invisible () final state, . We explicitly show that this system is completely
solvable with timing information.Comment: 14 pages, 5 figure
Timing information at HL-LHC: complete determination of masses of dark matter and long lived particle
A long-standing kinematic challenge in data analysis at hadron colliders is the determination of the masses of invisible particles. This issue is particularly relevant in searches for evidence of dark matter production, which remains one of the prominent targets of future collider experiments. In this paper, we show that the additional information from the precision timing measurements, provided by planned detector upgrades during the high- luminosity run of the LHC (HL-LHC), allows for previously unrealizable measurements of invisible particle kinematics. As a concrete example, we focus on the signal of pair produced long-lived particles (LLP1,2), each decaying with a displaced vertex to visible (V1,2) and invisible (I1,2) final state particles, pp → LLP1 + LLP2 → (V1 + I1) + (V2 + I2). We explicitly show that the complete kinematics of the invisible particles in such events can be determined with the addition of timing information, and evaluate the precision with which the masses of new long-lived and invisible particles can be determined
- …