5,251 research outputs found
Advertising: "The Good, the Bad and the Ugly"
We model the choice of firms competing in prices in a differentiated products market to bundle advertising messages with their goods in return for payment from advertisers. From the firms’ perspective, the potential to earn revenue from advertisers, makes advertising a “good”. However, because consumers in the product market dislike such advertising, the bundling dampens demand and in this sense is a “bad”. There is also a third role played by advertising, however. Since a firm that bundles advertisements with its good sells a less attractive good, it has to price more aggressively than one that does not do such bundling. Thus, bundling advertisements with the good can lead to more aggressive product pricing and thereby intensify product market competition. In this sense, advertising can make things “ugly”.
IR-improved Soft-wall AdS/QCD Model for Baryons
We construct an infrared-improved soft-wall AdS/QCD model for baryons by
considering the infrared-modified 5D conformal mass and Yukawa coupling of the
bulk baryon field. The model is also built by taking into account the
parity-doublet pattern for the excited baryons. When taking the bulk vacuum
structure of the meson field to be the one obtained consistently in the
infrared-improved soft-wall AdS/QCD model for mesons, we arrive at a consistent
prediction for the baryon mass spectrum in even and odd parity. The prediction
shows a remarkable agreement with the experimental data. We also perform a
calculation for the meson-nucleon coupling constant and obtain a
consistent result in comparison with the experimental data and many other
models.Comment: 12 pages, 4 tables, 1 figure, to be published in PL
Generalized Hofstadter model on a cubic optical lattice: From nodal bands to the three-dimensional quantum Hall effect
We propose that a tunable generalized three-dimensional Hofstadter
Hamiltonian can be realized by engineering the Raman-assisted hopping of
ultracold atoms in a cubic optical lattice. The Hamiltonian describes a
periodic lattice system under artificial magnetic fluxes in three dimensions.
For certain hopping configurations, the bulk bands can have Weyl points and
nodal loops, respectively, allowing the study of both the two nodal semimetal
states within this system. Furthermore, we illustrate that with proper rational
fluxes and hopping parameters, the system can exhibit the three-dimensional
quantum Hall effect when the Fermi level lies in the band gaps, which is
topologically characterized by one or two nonzero Chern numbers. Our proposed
optical-lattice system provides a promising platform for exploring various
exotic topological phases in three dimensions.Comment: 10 pages, 5 figure
The Design and Implementation of Mutual-Help Teaching System Based on Multimedia Network
AbstractWith the continuous increase in broadband users of China, the development of information, whose core is the Internet technology, laid a solid foundation for the implementation of in China. Network teaching, as a supplementary means inside and outside class, is increasingly being favored by the popular majority. In order to meet the new era of distance education, we need to develop a network teaching system, which allows the problems raised by users to be resolved quickly on this system. The communication system, including network teaching inside and outside the school, will be established and used in many fields, such as course development, online examination, homework management and teaching resource management
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