17,223 research outputs found
Electrophysiological Mechanisms of Atrial Flutter
Atrial flutter (AFL) is a common arrhythmia in clinical practice. Several experimental models such as tricuspid regurgitation model, tricuspid ring model, sterile pericarditis model and atrial crush injury model have provided important information about reentrant circuit and can test the effect of antiarrhythmic drugs. Human atrial flutter has typical and atypical forms. Typical atrial flutter rotates around tricuspid annulus and uses the crista terminalis and sometimes sinus venosa as the boundary. The IVC-tricuspid isthmus is a slow conduction zone and the target of radiofrequency ablation. Atypical atrial flutter may arise from the right or left atrium. Right atrial flutter includes upper loop reentry, free wall reentry and figure of eight reentry. Left atrial flutter includes mitral annular atrial flutter, pulmonary vein-related atrial flutter and left septal atrial flutter. Radiofrequency ablation of the isthmus between the boundaries can eliminate these arrhythmias
Definite and indefinite forms of Maxwell's equations for moving media
Electrodynamics of moving media - relativistic transformation of Maxwell equation
A Micromechanical Parylene Spiral-Tube Sensor and Its Applications of Unpowered Environmental Pressure/Temperature Sensing
A multi-function micromechanical pressure/temperature sensor incorporating a microfabricated parylene
spiral tube is presented. Its visible responses in expression of
in situ rotational tube deformation enable unpowered sensing
directly from optical device observation without electrical or
any powered signal transduction. Sensor characterizations
show promising pressure (14.46°/kPa sensitivity, 0.11 kPa
resolution) and temperature (6.28°/°C sensitivity, 0.24 °C
resolution) responses. Depending on different application
requests, this sensor can be individually utilized to measure
pressure/temperature of systems having one property varying
while the other stabilized, such as intraocular or other in vivo
pressure sensing of certain apparatus inside human bodies or
other biological targets. A straightforward sensor-pair
configuration has also been implemented to retrieve the
decoupled pressure and temperature readouts, hence
ultimately realizes a convenient environmental pressure and
temperature sensing in various systems
Floating-disk parylene micro check valve
A novel micro check valve which has nearly ideal fluidic
shunting behaviors is presented. Featuring a parylene-based
floating disk, this surface-micromachined check valve
ultimately realizes both zero forward cracking pressure and
zero reverse leakage in fluidic operations. Two different
floating disk designs have been implemented to demonstrate
functionality of the microvalve. Experimental data of
underwater testing successfully show that in-channel
floating-disk valves in both designs have great fluidic
performance close to an ideal check valve, except the
additional fluidic resistance in the order of 10^(13) N-s/m^5
based on dimensions of the fabricated devices. Their
pressure loading limit have been confirmed to be higher
than 300 kPa without water leakage. This type of micro
check valve is believed to have great use of flow control in
integrated microfluidics and lab-on-a-chip applications
Privatization, Efficiency Gap, and Subsidization with Excess Taxation Burden
It is well recognized that the impact of subsidization/taxation policies hinges on the market structure to which they apply. We show that different degree of efficiency gain sharply changes the comparisons of optimal subsidy, total outputs and social welfare between mixed and private duopoly. What is more, for an imposition of an optimal subsidy, welfare may increase, decrease, or remain unchanged with privatization, which depends on the level of the cost efficiency gap and the taxation burden. However, it may be possible to raise welfare through privatization as long as the efficiency gain prevails or no excess taxation burden exists. Government sets higher subsidy to stimulate firms' production if the value of cost-differential is assured.Privatization, Mixed Duopoly, Cost Efficiency Gap, Subsidization, Excess Taxation Burden
Optimal Algorithms for 2 x nAB Games--A Graph-Partition Approach
[[abstract]]This paper presents new and systematic methodologies to analyze deductive games and obtain optimal algorithms for 2 ? n AB games, where n ? 2. We have invented a graphic model to represent the game-guessing process. With this novel approach, we find some symmetric and recursive structures in the process. This not only reduces the size of the search space, but also helps us to derive the optimum strategies more efficiently. By using this technique, we develop optimal strategies for 2 ? n AB games in the expected and worst cases, and are able to derive the following new results: (1) ?n/2? + 1 guesses
are necessary and sufficient for 2 ? n AB games in the worst case, (2) the minimum number of guesses required for 2 ? n AB games in the expected case is (4n3 + 21n2 - 76n + 72)/12n(n - 1) if n is even, and (4n3 + 21n2 - 82n + 105)/12n(n - 1) if n is odd.
The optimization of this problem bears resemblance with other computational problems, such as circuit testing, differential cryptanalysis, on-line models with equivalent queries, and additive search problems. Any conclusion of this kind of deductive game may be applied, although probably not directly, to any of these problems, as well as to any other combinatorial optimization problem.
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