9,023 research outputs found
The Spirit of Capitalism and Excess Smoothness
In a recent paper [Luo, Smith, and Zou (2009)] we showed that the spirit of capitalism could in theory resolve the two fundamental anomalies of modern consumption theory, excess sensitivity and excess smoothness. However, that basic model could not plausibly explain the empirical magnitude of excess smoothness. In this paper we develop two extensions of the model ¡ª one with transitory and permanent shocks to income, the other with a stochastic interest rate ¡ª that where the spirit of capitalism can explain excess smoothness.The spirit of capitalism, Consumption smoothing, Interest rate risk
Optimization of synchronization in gradient clustered networks
We consider complex clustered networks with a gradient structure, where sizes
of the clusters are distributed unevenly. Such networks describe more closely
actual networks in biophysical systems and in technological applications than
previous models. Theoretical analysis predicts that the network
synchronizability can be optimized by the strength of the gradient field but
only when the gradient field points from large to small clusters. A remarkable
finding is that, if the gradient field is sufficiently strong,
synchronizability of the network is mainly determined by the properties of the
subnetworks in the two largest clusters. These results are verified by
numerical eigenvalue analysis and by direct simulation of synchronization
dynamics on coupled-oscillator networks.Comment: PRE, 76, 056113 (2007
Transient thermal performance prediction method for parabolic trough solar collector under fluctuating solar radiation
As the effect of the global warming is becoming noticeable, the importance for environmental sustainability has been raised. Parabolic trough solar thermal collector system, which is one of the solutions to reduce the carbon dioxide emission, is a mature technology for electricity generation. Malaysia is a tropical country with long daytime, which makes suitable for solar thermal applications with parabolic trough solar thermal collectors. However, the high humidity causes the solar radiation to fluctuate. In order to simulate the solar thermal collectors’ performance at an early design stage of solar thermal power generation systems, fast still accurate transient thermal performance prediction methodis required. Although multiple transient thermal simulation methodologies exist, they are not suited especially at an early design stage where quick but reasonably accurate thermal performance prediction is needed because of their long calculation time. In this paper, a transient thermal prediction method is developed to predict exit temperature of parabolic trough collectors under fluctuating solar radiation. The method is governed by simple summation operations and requires much less calculating time than the existing numerical methods. If the radiation heat loss at the parabolic trough collector tube surface is small, the working fluid temperature rise may be approximated as proportional to the receiving heat flux. The fluctuating solar radiation is considered as a series of heat flux pulses applied for a short period of time. The time dependent solar collector exit temperature is approximated by superimposing the exit temperature rise caused by each heat flux pulse. To demonstrate the capabilities of the proposed methodology, the solar collector exit temperature for one-day operation is predicted. The predicted solar collector exit temperature captures the trend of a finite element analysis result well. Still, the largest temperature difference is 38.8K and accuracy is not satisfactory. Currently, the accuracy of the proposed method is being improved. At the same time, its capabilities are being expanded
Domain Wall Brane in Eddington Inspired Born-Infeld Gravity
Recently, inspired by Eddington's theory, an alternative gravity called
Eddington-inspired Born-Infeld gravity was proposed by Baados
and Ferreira. It is equivalent to Einstein's general relativity in vacuum, but
deviates from it when matter is included. Interestingly, it seems that the
cosmological singularities are prevented in this theory. Based on the new
theory, we investigate a thick brane model with a scalar field presenting in
the five-dimensional background. A domain wall solution is obtained, and
further, we find that at low energy the four-dimensional Einstein gravity is
recovered on the brane. Moreover, the stability of gravitational perturbations
is ensured in this model.Comment: 16 pages, 2 figures, improved versio
Subcarrier Index Coordinate Expression (SICE): An Ultra-low-power OFDM-compatible Wireless Communications Scheme Tailored for Internet of Things
This paper describes a novel data modulation method for ultra-low-power wireless uplink communication between a client device of the internet of things (IoT) and a base station (or an access point). The proposed scheme is dubbed as subcarrier index coordinate expression (SICE), which utilizes the indices of orthogonal frequency division multiplexing (OFDM) subcarriers and waveforms with different phase shifts to represent the information to be sent. SICE is targeted for IoT applications with low data rate requirements, and is especially useful for battery-powered IoT devices demanding low-power communications, due to its characteristics of low peak to average power ratio (PAPR) and high power efficiency in wireless transmission. Unlike ongoing efforts in IoT wireless communications at standardization organizations which focus on simplifying functionalities of the existing protocols to save power, the technique developed in this paper is a fundamentally new and yet OFDM-compatible physical-layer approach that can drastically reduce power consumption of data transmission.Engineering and Applied Science
Deterministic quantum teleportation between distant atomic objects
Quantum teleportation is a key ingredient of quantum networks and a building
block for quantum computation. Teleportation between distant material objects
using light as the quantum information carrier has been a particularly exciting
goal. Here we demonstrate a new element of the quantum teleportation landscape,
the deterministic continuous variable (cv) teleportation between distant
material objects. The objects are macroscopic atomic ensembles at room
temperature. Entanglement required for teleportation is distributed by light
propagating from one ensemble to the other. Quantum states encoded in a
collective spin state of one ensemble are teleported onto another ensemble
using this entanglement and homodyne measurements on light. By implementing
process tomography, we demonstrate that the experimental fidelity of the
quantum teleportation is higher than that achievable by any classical process.
Furthermore, we demonstrate the benefits of deterministic teleportation by
teleporting a dynamically changing sequence of spin states from one distant
object onto another
- …