913 research outputs found
Analisis Penawaran Pasar dan Kualitas Website Beautyhaulindo dalam Meningkatkan Pembelian Ulang dengan Intervening Kepuasan Pelanggan dan Kepercayaan Pelanggan
This research aims to examine and analyze factor which affect customer satisfaction, trust, and interest to buy back on beautyhaulindo website that became the object of research which is in the sub category of fashion in online retail cosmetics in Indonesia. The study design used is descriptive and explanatory research type of survey methods. The population is all customer who has bought in year 2017. Estimation maximum likelihood is use from this observation like 100-200 sample and5 observation from each parameter and in this observation have 50 indicators , if estimated is 250 sample. Data were collected using questionnaires given from 250 respondents. The method of analysis used is SEM (Structural Equation Model).The result of the research shows that the market offering variable to the satisfaction of the beautyhaulindo website influence positively and significantly, the variable of website quality to the satisfaction of the beautyhaulindo website influence positively and significantly, the market offering variable toward the trust of beautyhaulindo website influence positively and significantly, customer trust beautyhaulindo website have a positive and significant effect, customer satisfaction variable to the interest of repeat purchase at beautyhaulindo website have positive and significant influence, customer trust variable to repurchase interest in beautyhaulindo website have positive and significant influence. The suggestion for the next observation is use the sub product and add the new variables like brand image and product qualit
A quantitative analysis of measures of quality in science
Condensing the work of any academic scientist into a one-dimensional measure
of scientific quality is a difficult problem. Here, we employ Bayesian
statistics to analyze several different measures of quality. Specifically, we
determine each measure's ability to discriminate between scientific authors.
Using scaling arguments, we demonstrate that the best of these measures require
approximately 50 papers to draw conclusions regarding long term scientific
performance with usefully small statistical uncertainties. Further, the
approach described here permits the value-free (i.e., statistical) comparison
of scientists working in distinct areas of science.Comment: 11 pages, 8 figures, 4 table
Peer-to-Peer Secure Multi-Party Numerical Computation Facing Malicious Adversaries
We propose an efficient framework for enabling secure multi-party numerical
computations in a Peer-to-Peer network. This problem arises in a range of
applications such as collaborative filtering, distributed computation of trust
and reputation, monitoring and other tasks, where the computing nodes is
expected to preserve the privacy of their inputs while performing a joint
computation of a certain function. Although there is a rich literature in the
field of distributed systems security concerning secure multi-party
computation, in practice it is hard to deploy those methods in very large scale
Peer-to-Peer networks. In this work, we try to bridge the gap between
theoretical algorithms in the security domain, and a practical Peer-to-Peer
deployment.
We consider two security models. The first is the semi-honest model where
peers correctly follow the protocol, but try to reveal private information. We
provide three possible schemes for secure multi-party numerical computation for
this model and identify a single light-weight scheme which outperforms the
others. Using extensive simulation results over real Internet topologies, we
demonstrate that our scheme is scalable to very large networks, with up to
millions of nodes. The second model we consider is the malicious peers model,
where peers can behave arbitrarily, deliberately trying to affect the results
of the computation as well as compromising the privacy of other peers. For this
model we provide a fourth scheme to defend the execution of the computation
against the malicious peers. The proposed scheme has a higher complexity
relative to the semi-honest model. Overall, we provide the Peer-to-Peer network
designer a set of tools to choose from, based on the desired level of security.Comment: Submitted to Peer-to-Peer Networking and Applications Journal (PPNA)
200
Dynamics, correlations and phases of the micromaser
The micromaser possesses a variety of dynamical phase transitions
parametrized by the flux of atoms and the time-of-flight of the atom within the
cavity. We discuss how these phases may be revealed to an observer outside the
cavity using the long-time correlation length in the atomic beam. Some of the
phase transitions are not reflected in the average excitation level of the
outgoing atom, which is the commonly used observable. The correlation length is
directly related to the leading eigenvalue of the time evolution operator,
which we study in order to elucidate the phase structure. We find that as a
function of the time-of-flight the transition from the thermal to the maser
phase is characterized by a sharp peak in the correlation length. For longer
times-of-flight there is a transition to a phase where the correlation length
grows exponentially with the flux. We present a detailed numerical and
analytical treatment of the different phases and discuss the physics behind
them.Comment: 60 pages, 18 figure files, Latex + \special{} for the figures, (some
redundant figures are eliminated and others are changed
Magnetic Impurity in a Metal with Correlated Conduction Electrons: An Infinite Dimensions Approach
We consider the Hubbard model with a magnetic Anderson impurity coupled to a
lattice site. In the case of infinite dimensions, one-particle correlations of
the impurity electron are described by the effective Hamiltonian of the
two-impurity system. One of the impurities interacts with a bath of free
electrons and represents the Hubbard lattice, and the other is coupled to the
first impurity by the bare hybridization interaction. A study of the effective
two-impurity Hamiltonian in the frame of the 1/N expansion and for the case of
a weak conduction-electron interaction (small U) reveals an enhancement of the
usual exponential Kondo scale. However, an intermediate interaction (U/D = 1 -
3), treated by the variational principle, leads to the loss of the exponential
scale. The Kondo temperature T_K of the effective two-impurity system is
calculated as a function of the hybridization parameter and it is shown that
T_K decreases with an increase of U. The non-Fermi-liquid character of the
Kondo effect in the intermediate regime at the half filling is discussed.Comment: 12 pages with 8 PS figures, RevTe
On a discrete Davey-Stewartson system
We propose a differential difference equation in and study it by
Hirota's bilinear method. This equation has a singular continuum limit into a
system which admits the reduction to the Davey-Stewartson equation. The
solutions of this discrete DS system are characterized by Casorati and Grammian
determinants. Based on the bilinear form of this discrete DS system, we
construct the bilinear B\"{a}cklund transformation which enables us to obtain
its Lax pair.Comment: 12 pages, 2 figure
Iterated Conformal Dynamics and Laplacian Growth
The method of iterated conformal maps for the study of Diffusion Limited
Aggregates (DLA) is generalized to the study of Laplacian Growth Patterns and
related processes. We emphasize the fundamental difference between these
processes: DLA is grown serially with constant size particles, while Laplacian
patterns are grown by advancing each boundary point in parallel, proportionally
to the gradient of the Laplacian field. We introduce a 2-parameter family of
growth patterns that interpolates between DLA and a discrete version of
Laplacian growth. The ultraviolet putative finite-time singularities are
regularized here by a minimal tip size, equivalently for all the models in this
family. With this we stress that the difference between DLA and Laplacian
growth is NOT in the manner of ultraviolet regularization, but rather in their
deeply different growth rules. The fractal dimensions of the asymptotic
patterns depend continuously on the two parameters of the family, giving rise
to a "phase diagram" in which DLA and discretized Laplacian growth are at the
extreme ends. In particular we show that the fractal dimension of Laplacian
growth patterns is much higher than the fractal dimension of DLA, with the
possibility of dimension 2 for the former not excluded.Comment: 13 pages, 12 figures, submitted to Phys. Rev.
Biopolymer-based structuring of liquid oil into soft solids and oleogels using water-continuous emulsions as templates
Physical trapping of a hydrophobic liquid oil in a matrix of water-soluble biopolymers was achieved using a facile two-step process by first formulating a surfactant-free oil-in-water emulsion stabilized by biopolymers (a protein and a polysaccharide) followed by complete removal of the water phase (by either high- or low-temperature drying of the emulsion) resulting in structured solid systems containing a high concentration of liquid oil (above 97 wt %). The microstructure of these systems was revealed by confocal and cryo-scanning electron microscopy, and the effect of biopolymer concentrations on the consistency of emulsions as well as the dried product was evaluated using a combination of small-amplitude oscillatory shear rheometry and large deformation fracture studies. The oleogel prepared by shearing the dried product showed a high gel strength as well as a certain degree of thixotropic recovery even at high temperatures. Moreover, the reversibility of the process was demonstrated by shearing the dried product in the presence of water to obtain reconstituted emulsions with rheological properties comparable to those of the fresh emulsion
On two problems in graph Ramsey theory
We study two classical problems in graph Ramsey theory, that of determining
the Ramsey number of bounded-degree graphs and that of estimating the induced
Ramsey number for a graph with a given number of vertices.
The Ramsey number r(H) of a graph H is the least positive integer N such that
every two-coloring of the edges of the complete graph contains a
monochromatic copy of H. A famous result of Chv\'atal, R\"{o}dl, Szemer\'edi
and Trotter states that there exists a constant c(\Delta) such that r(H) \leq
c(\Delta) n for every graph H with n vertices and maximum degree \Delta. The
important open question is to determine the constant c(\Delta). The best
results, both due to Graham, R\"{o}dl and Ruci\'nski, state that there are
constants c and c' such that 2^{c' \Delta} \leq c(\Delta) \leq 2^{c \Delta
\log^2 \Delta}. We improve this upper bound, showing that there is a constant c
for which c(\Delta) \leq 2^{c \Delta \log \Delta}.
The induced Ramsey number r_{ind}(H) of a graph H is the least positive
integer N for which there exists a graph G on N vertices such that every
two-coloring of the edges of G contains an induced monochromatic copy of H.
Erd\H{o}s conjectured the existence of a constant c such that, for any graph H
on n vertices, r_{ind}(H) \leq 2^{c n}. We move a step closer to proving this
conjecture, showing that r_{ind} (H) \leq 2^{c n \log n}. This improves upon an
earlier result of Kohayakawa, Pr\"{o}mel and R\"{o}dl by a factor of \log n in
the exponent.Comment: 18 page
A population of luminous accreting black holes with hidden mergers
Major galaxy mergers are thought to play an important part in fuelling the
growth of supermassive black holes. However, observational support for this
hypothesis is mixed, with some studies showing a correlation between merging
galaxies and luminous quasars and others showing no such association. Recent
observations have shown that a black hole is likely to become heavily obscured
behind merger-driven gas and dust, even in the early stages of the merger, when
the galaxies are well separated (5 to 40 kiloparsecs). Merger simulations
further suggest that such obscuration and black-hole accretion peaks in the
final merger stage, when the two galactic nuclei are closely separated (less
than 3 kiloparsecs). Resolving this final stage requires a combination of
high-spatial-resolution infrared imaging and high-sensitivity hard-X-ray
observations to detect highly obscured sources. However, large numbers of
obscured luminous accreting supermassive black holes have been recently
detected nearby (distances below 250 megaparsecs) in X-ray observations. Here
we report high-resolution infrared observations of hard-X-ray-selected black
holes and the discovery of obscured nuclear mergers, the parent populations of
supermassive-black-hole mergers. We find that obscured luminous black holes
(bolometric luminosity higher than 2x10^44 ergs per second) show a significant
(P<0.001) excess of late-stage nuclear mergers (17.6 per cent) compared to a
sample of inactive galaxies with matching stellar masses and star formation
rates (1.1 per cent), in agreement with theoretical predictions. Using
hydrodynamic simulations, we confirm that the excess of nuclear mergers is
indeed strongest for gas-rich major-merger hosts of obscured luminous black
holes in this final stage.Comment: To appear in the 8 November 2018 issue of Nature. This is the
authors' version of the wor
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