10,758 research outputs found
Split-cross-bridge resistor for testing for proper fabrication of integrated circuits
An electrical testing structure and method is described whereby a test structure is fabricated on a large scale integrated circuit wafer along with the circuit components and has a van der Pauw cross resistor in conjunction with a bridge resistor and a split bridge resistor, the latter having two channels each a line width wide, corresponding to the line width of the wafer circuit components, and with the two channels separated by a space equal to the line spacing of the wafer circuit components. The testing structure has associated voltage and current contact pads arranged in a two by four array for conveniently passing currents through the test structure and measuring voltages at appropriate points to calculate the sheet resistance, line width, line spacing, and line pitch of the circuit components on the wafer electrically
How to Regulate Vertical Market Structure in Network Industries
This paper analyzes the equilibrium outcomes in a network industry under different vertical market structures. In this industry, an upstream monopolist operates a network used as an input to produce horizontally differentiated final products that are imperfect substitutes. Three potential drawbacks of market structure regulation are analyzed: (i) double marginalization, (ii) underinvestment, and (iii) vertical foreclosure. We explore the conditions under which these effects emerge and discuss when the breakup of an integrated network monopolist is adequate.access pricing, investment, vertical foreclosure
Scale dependence and collinear subtraction terms for Higgs production in gluon fusion at N3LO
The full, explicit, scale dependence of the inclusive N3LO cross section for
single Higgs hadroproduction is obtained by calculating the convolutions of
collinear splitting kernels with lower-order partonic cross sections. We
provide results for all convolutions of splitting kernels and lower-order
partonic cross sections to the order in epsilon needed for the full N3LO
computation, as well as their expansions around the soft limit. We also discuss
the size of the total scale uncertainty at N3LO that can be anticipated with
existing information.Comment: 27 pages, 8 figure, 1 table, 8 ancillary files. v2: added 4
references, changed labelling of contour plot
On Interference Alignment and the Deterministic Capacity for Cellular Channels with Weak Symmetric Cross Links
In this paper, we study the uplink of a cellular system using the linear
deterministic approximation model, where there are two users transmitting to a
receiver, mutually interfering with a third transmitter communicating with a
second receiver. We give an achievable coding scheme and prove its optimality,
i.e. characterize the capacity region. This scheme is a form of interference
alignment which exploits the channel gain difference of the two-user cell.Comment: Submitted to IEEE International Symposium on Information Theory
(ISIT) 2011, 5 page
John Searle: Making the Social World. The Structure of Human Civilization
ontology, social institutions, social reality, commitment, speech act, social science
The imprint of pulsar parameters on the morphology of Pulsar Wind Nebulae
The morphology of young Pulsar Wind Nebulae (PWN) is largely determined by
the properties of the wind injected by the pulsar. We have used a recent
parametrization of the wind obtained from Force Free Electrodynamics
simulations of pulsar magnetospheres to simulate nebulae for different sets of
pulsar parameters. We performed axisymmetric Relativistic Magnetohydrodynamics
simulations to test the morphology dependence of the nebula on the obliquity of
the pulsar and on the magnetization of the pulsar wind. We compare these
simulations to the morphology of the Vela and Crab PWN. We find that the
morphology of Vela can be reproduced qualitatively if the pulsar obliquity
angle is alpha ~45deg and the magnetization of the wind is high (sigma_0 ~
3.0). A morphology similar to the one of the Crab Nebula is only obtained for
low magnetization simulations with alpha >~ 45deg. Interestingly, we find that
Kelvin-Helmholtz instabilities produce small scale turbulences downstream of
the reverse shock of the pulsar wind.Comment: 18 pages, 12 figures, accepted by MNRA
The surprising Crab pulsar and its nebula: A review
The Crab nebula and its pulsar (referred to together as "Crab") have
historically played a central role in astrophysics. True to their legacy,
several unique discoveries have been made recently. The Crab was found to emit
gamma-ray pulsations up to energies of 400 GeV, beyond what was previously
expected from pulsars. Strong gamma-ray flares, of durations of a few days were
discovered from within the nebula, while the source was previously expected to
be stable in flux on these time scales. Here we review these intriguing and
suggestive developments. In this context we give an overview of the
observational properties of the Crab and our current understanding of pulsars
and their nebulae.Comment: Review for Reports on Progress in Physics, 31 pages, 11 figures. For
a video abstract see the journal web page of the article or
http://bcove.me/391e37d
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