3,507 research outputs found
Is it Social Influence on Beliefs Under Ambiguity? A Possible Explanation for Volatility Clustering
Influencing and being influenced by others is the very essence of human behaviour. We put forward an exploratory asset-pricing model allowing for social influence on investor judgments under ambiguity. The time series of returns generated by our model displays volatility clustering, a puzzling stylised fact observed in financial markets. This suggests that social influence on investor judgments may be playing a role in generating volatility clustering.Social Influence, Knightian Uncertainty, Ambiguity, Volatility Clustering
Utilization of solar energy in developing countries: Identifying some potential markets
The potential use of solar electricity generated from photovoltaic cells is examined for nineteen developing nations. Energy and economic profiles are summarized for each country. A comparison is made between the use of autogeneration and photovoltaics in a rural area of Haiti
Improving wafer-scale Josephson junction resistance variation in superconducting quantum coherent circuits
Quantum bits, or qubits, are an example of coherent circuits envisioned for
next-generation computers and detectors. A robust superconducting qubit with a
coherent lifetime of (100 s) is the transmon: a Josephson junction
functioning as a non-linear inductor shunted with a capacitor to form an
anharmonic oscillator. In a complex device with many such transmons, precise
control over each qubit frequency is often required, and thus variations of the
junction area and tunnel barrier thickness must be sufficiently minimized to
achieve optimal performance while avoiding spectral overlap between neighboring
circuits. Simply transplanting our recipe optimized for single, stand-alone
devices to wafer-scale (producing 64, 1x1 cm dies from a 150 mm wafer)
initially resulted in global drifts in room-temperature tunneling resistance of
30%. Inferring a critical current variation from this
resistance distribution, we present an optimized process developed from a
systematic 38 wafer study that results in 3.5% relative standard deviation
(RSD) in critical current () for 3000 Josephson junctions (both single-junctions and
asymmetric SQUIDs) across an area of 49 cm. Looking within a 1x1 cm moving
window across the substrate gives an estimate of the variation characteristic
of a given qubit chip. Our best process, utilizing ultrasonically assisted
development, uniform ashing, and dynamic oxidation has shown = 1.8% within 1x1 cm, on average,
with a few 1x1 cm areas having 1.0% (equivalent to 0.5%). Such stability would drastically improve the yield of
multi-junction chips with strict critical current requirements.Comment: 10 pages, 4 figures. Revision includes supplementary materia
Aeroacoustic and aerodynamic performances of an aerofoil subjected to sinusoidal leading edges
This paper presents the preliminary results on the aeroacoustic and aerodynamic performances of a NACA65-(12)10 aerofoil subjected to 12 sinusoidal leading edges. The serration patterns of these leading edges are formed by cutting into the main body of the aerofoil, instead of extending the leading edges. Any of the leading edges, when attached to the main body of the aerofoil, will always result in the same overall chord length. The experiment was mainly performed in an aeroacoustic wind tunnel facility, although a separate aerodynamic type wind tunnel was also used for the force measurements. These sinusoidal leading edges were investigated for their effectiveness in suppressing the laminar instability tonal noise (trailing edge self-noise) and turbulence–leading edge interaction noise. The largest reduction in aerofoil noise tends to associate with the sinusoidal leading edge of the largest amplitude, and smallest wavelength. However, noticeable noise increase at high frequency is also observed for this combination of serration. In terms of the aerodynamic performance, increasing the serration wavelength tends to improve the stall angles, but the lift coefficient at the pre-stall regime is generally lower than that produced by the baseline leading edge. For a sinusoidal leading edge with large serration amplitude, the effect of the reduction in “lift-generating” surface is manifested in the significant reduction of the lift coefficients and lift curve slope. The sinusoidal leading edge that produces the best performance in the post-stall regime belongs to the largest wavelength and smallest amplitude, where the lift coefficients are shown to be better than the baseline leading edge. In conclusion, large amplitude and small wavelength is beneficial for noise reduction, whilst to maintain the aerodynamic lift a small amplitude and large wavelength is preferred
Resveratrol Induced Apoptosis in a Human Adenosquamous Carcinoma Cell Line (CAL-27 Cells)
Radiotherapy and surgery are the two principal modalities in the treatment of head and neck cancers, and both therapies can result in severe adverse effects and ultimately lower the quality of life. It is of paramount importance to develop reagents that target the cancer cell specifically without affecting the normal non-cancer cells. Using the tongue cancer cell line Cal 27 as a model system, we dissected the molecular mechanism of the resveratrol-induced cancer cell apoptosis. After demonstrating that resveratrol induces the cancer cell apoptosis in a dose- and time-dependent manner, a systemic apoptosis protein array was conducted to identify the resveratrol-induced proteins pertinent to the apoptotic pathways. Ten of the 43 proteins included in the array were up- or down-regulated by resveratrol by about 50 percent. Finally, the activation of caspase-3 and the cleavage of PARP in resveratrol-induced apoptotic cells were confirmed by western blot. We postulate resveratrol induces apoptosis in Cal-27 cells which will render the cells from being able to repair double-stranded-break in the DNA as both P53 and P21 will be up regulated and thus leading to senesce of the cell replication, suggesting that resveratrol could potentially serve as a chemo-preventive reagent
Scattering into one-dimensional waveguides from a coherently-driven quantum-optical system
We develop a new computational tool and framework for characterizing the
scattering of photons by energy-nonconserving Hamiltonians into unidirectional
(chiral) waveguides, for example, with coherent pulsed excitation. The temporal
waveguide modes are a natural basis for characterizing scattering in quantum
optics, and afford a powerful technique based on a coarse discretization of
time. This overcomes limitations imposed by singularities in the
waveguide-system coupling. Moreover, the integrated discretized equations can
be faithfully converted to a continuous-time result by taking the appropriate
limit. This approach provides a complete solution to the scattered photon field
in the waveguide, and can also be used to track system-waveguide entanglement
during evolution. We further develop a direct connection between quantum
measurement theory and evolution of the scattered field, demonstrating the
correspondence between quantum trajectories and the scattered photon state. Our
method is most applicable when the number of photons scattered is known to be
small, i.e. for a single-photon or photon-pair source. We illustrate two
examples: analytical solutions for short laser pulses scattering off a
two-level system and numerically exact solutions for short laser pulses
scattering off a spontaneous parametric downconversion (SPDC) or spontaneous
four-wave mixing (SFWM) source. Finally, we note that our technique can easily
be extended to systems with multiple ground states and generalized scattering
problems with both finite photon number input and coherent state drive,
potentially enhancing the understanding of, e.g., light-matter entanglement and
photon phase gates.Comment: Numerical package in collaboration with Ben Bartlett (Stanford
University), implemented in QuTiP: The Quantum Toolbox in Python, Quantum
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Studies in Sindi society the anthropology of selected Sindi communities
The purpose of this thesis is to accept the fact that there is a territory called Sind which has possessed and still possesses a regional identity and then to examine the nature of society within it. The emphasis throughout is on social and cultural characteristics related as far as possible to the various forces affecting them and operating within them, a field of study lying between Social Geography and Social Anthropology. Within Sind there exist diversities of religion, of occupation and economy but overriding these there has been until recently an undisputed social and cultural unity manifesting itself in language folk customs, mysticism and a class / caste division of society. This unity has been associated with subsistenceorientated agricultural economy in which family and kinship have aided survival in a harsh a rid environment. Sind has been a region peripheral to the mainstream of Asian change and regional and social unity remained undisturbed for centuries. Two phenomena have recently disturbed this traditional continuity, first the effects of partition of All - India and secondly urbanization in the developing state of Pakistan. The question remains whether traditional rural - based unity will remain dominant or whether a new hybrid culture will appea
Junaid Rana. Terrifying Muslims: Race and Labor in the South Asian Diaspora. Durham & London: Duke University Press. 2011.
Book review
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