3,835 research outputs found
Social Network Analysis of Video Bloggers\u27 Community
Video blogs (or vlogs) have become increasingly popular in recent years. As the main motivation for vlogging is to interact with other vloggers, it is important to investigate the structure of the videobloggers\u27 community and the interactions among vloggers. This research conducted a quantitative analysis using social network analysis. A list of personal vloggers was identified from VlogDIR and linking patters of vlogs were analyzed. The results suggest that video bloggers\u27 community is highly decentralized and exhibits a core/periphery structure
Designing Motorcycles via the Web: Improved Aesthetics and Consumer Preference
The purpose of this research was to examine how manipulation of the aesthetic appeal of a motorcycle’s image on a web page might elucidate trends in consumer preference. To this end, website visitors were encouraged to reconfigure a blueprint of motorcycle to make it more appealing. These alterations to its confirmation were analyzed to identify patterns of preference that were then compared to the marketplace in general. It was observed that aesthetic preferences recognized by the design method were similar to trends within the motorcycle building/buying public
Conductance spectra of metallic nanotube bundles
We report a first principles analysis of electronic transport characteristics
for (n,n) carbon nanotube bundles. When n is not a multiple of 3, inter-tube
coupling causes universal conductance suppression near Fermi level regardless
of the rotational arrangement of individual tubes. However, when n is a
multiple of 3, the bundles exhibit a diversified conductance dependence on the
orientation details of the constituent tubes. The total energy of the bundle is
also sensitive to the orientation arrangement only when n is a multiple of 3.
All the transport properties and band structures can be well understood from
the symmetry consideration of whether the rotational symmetry of the individual
tubes is commensurate with that of the bundle
Reconsideration of Second Harmonic Generation from neat Air/Water Interface: Broken of Kleinman Symmetry from Dipolar Contribution
It has been generally accepted that there are significant quadrupolar and
bulk contributions to the second harmonic generation (SHG) reflected from the
neat air/water interface, as well as common liquid interfaces. Because there
has been no general methodology to determine the quadrupolar and bulk
contributions to the SHG signal from a liquid interface, this conclusion was
reached based on the following two experimental phenomena. Namely, the broken
of the macroscopic Kleinman symmetry, and the significant temperature
dependence of the SHG signal from the neat air/water interface. However,
because sum frequency generation vibrational spectroscopy (SFG-VS) measurement
of the neat air/water interface observed no apparent temperature dependence,
the temperature dependence in the SHG measurement has been reexamined and
proven to be an experimental artifact. Here we present a complete microscopic
analysis of the susceptibility tensors of the air/water interface, and show
that dipolar contribution alone can be used to address the issue of broken of
the macroscopic Kleinman symmetry at the neat air/water interface. Using this
analysis, the orientation of the water molecules at the interface can be
obtained, and it is consistent with the measurement from SFG-VS. Therefore, the
key rationales to conclude significantly quadrupolar and bulk contributions to
the SHG signal of the neat air/water interface can no longer be considered as
valid as before. This new understanding of the air/water interface can shed
light on our understanding of the nonlinear optical responses from other
molecular interfaces as well
On the Proof of Dark Matter, the Law of Gravity and the Mass of Neutrinos
We develop a new method to predict the density associated with weak lensing
maps of (un)relaxed clusters in a range of theories interpolating between GR
and MOND (General Relativity and Modified Newtonian Dynamics). We apply it to
fit the lensing map of the bullet merging cluster 1E0657-56, in order to
constrain more robustly the nature and amount of collisionless matter in
clusters {\it beyond} the usual assumption of spherical equilibrium
(Pointecouteau & Silk 2005) and the validity of GR on cluster scales (Clowe et
al. 2006). Strengthening the proposal of previous authors we show that the
bullet cluster is dominated by a collisionless -- most probably non-baryonic --
component in GR as well as in MOND, a result consistent with the dynamics of
many X-ray clusters. Our findings add to the number of known pathologies for a
purely baryonic MOND, including its inability to fit the latest data from the
Wilkinson Microwave Anisotropy Probe. A plausible resolution of all these
issues and standard issues of Cold Dark Matter with galaxy rotation curves is
the "marriage" of MOND with ordinary hot neutrinos of 2eV. This prediction is
just within the GR-independent maximum of neutrino mass from current
-decay experiments, and is falsifiable by the Karlsruhe Tritium Neutrino
(KATRIN) experiment by 2009. Issues of consistency with strong lensing arcs and
the large relative velocity of the two clusters comprising the bullet cluster
are also addressed.Comment: 4 pages, 1 figure, accepted for publication in ApJL. Added a simple
model of the bullet cluster's high velocity in TeVeS, and discussions of
sterile neutrinos and of non-uniqueness of the lensing deprojectio
Quasispecies distribution of Eigen model
We study sharp peak landscapes (SPL) of Eigen model from a new perspective
about how the quasispecies distribute in the sequence space. To analyze the
distribution more carefully, we bring forth two tools. One tool is the variance
of Hamming distance of the sequences at a given generation. It not only offers
us a different avenue for accurately locating the error threshold and
illustrates how the configuration of the distribution varies with copying
fidelity in the sequence space, but also divides the copying fidelity into
three distinct regimes. The other tool is the similarity network of a certain
Hamming distance , by which we can get a visual and in-depth result
about how the sequences distribute. We find that there are several local optima
around the center (global optimum) in the distribution of the sequences
reproduced near the threshold. Furthermore, it is interesting that the
distribution of clustering coefficient follows lognormal distribution
and the curve of clustering coefficient of the network versus
appears as linear behavior near the threshold.Comment: 13 pages, 6 figure
Quantum mechanical photon-count formula derived by entangled state representation
By introducing the thermo entangled state representation, we derived four new
photocount distribution formulas for a given density operator of light field.
It is shown that these new formulas, which is convenient to calculate the
photocount, can be expressed as such integrations over Laguree-Gaussian
function with characteristic function, Wigner function, Q-function, and
P-function, respectively.Comment: 5 pages, no figur
Self-Actuated, Thermo-Responsive Hydrogel Valves for Lab on a Chip
An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aimed at the detection of pathogens in oral fluids at the location of the sample collection. The paper describes the construction and characterization of the hydrogel valves and their application for flow control, sample and reagent metering, sample distribution into multiple analysis paths, and the sealing of a polymerase chain reaction (PCR) reactor to suppress bubble formation. The hydrogel-based flow control is electronically addressable, does not require any moving parts, introduces minimal dead volume, is leakage and contaminant free, and is biocompatible
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