339,552 research outputs found

    Internet-induced marketing techniques: Critical factors in viral marketing campaigns

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    The rapid diffusion of the Internet and the emergence of various social constructs facilitated by Internet technologies are changing the drivers that define how marketing techniques are developed and refined. This paper identifies critical factors for viral marketing, an Internet-based ‘word-of-mouth’ marketing technique. Based on existing knowledge, five types of viral marketing factors that may critically influence the success of viral marketing campaigns are identified. These factors are the overall structure of the campaign, the characteristics of the product or service, the content of the message, the characteristics of the diffusion and, the peer-to-peer information conduit. The paper discusses three examples of viral marketing campaigns and identifies the specific factors in each case that influence its success. The paper concludes with a viral marketing typology differentiating between viral marketing communications, unintended viral marketing and commercial viral marketing. This is still a rapidly evolving area and further research is clearly needed to monitor new developments and make sense of the radical changes these developments bring to the market

    Quantum Doubles from a Class of Noncocommutative Weak Hopf Algebras

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    The concept of biperfect (noncocommutative) weak Hopf algebras is introduced and their properties are discussed. A new type of quasi-bicrossed products are constructed by means of weak Hopf skew-pairs of the weak Hopf algebras which are generalizations of the Hopf pairs introduced by Takeuchi. As a special case, the quantum double of a finite dimensional biperfect (noncocommutative) weak Hopf algebra is built. Examples of quantum doubles from a Clifford monoid as well as a noncommutative and noncocommutative weak Hopf algebra are given, generalizing quantum doubles from a group and a noncommutative and noncocommutative Hopf algebra, respectively. Moreover, some characterisations of quantum doubles of finite dimensional biperfect weak Hopf algebras are obtained.Comment: LaTex 18 pages, to appear in J. Math. Phys. (To compile, need pb-diagram.sty, pb-lams.sty, pb-xy.sty and lamsarrow.sty

    Magnetic field dependence of electronic properties of MoS2_2 quantum dots with different edges

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    Using the tight-binding approach, we investigate the energy spectrum of square, triangular and hexagonal MoS2_2 quantum dots (QDs) in the presence of a perpendicular magnetic field. Novel edge states emerge in MoS2_2 QDs, which are distributed over the whole edge which we call ring states. The ring states are robust in the presence of spin-orbit coupling (SOC). The corresponding energy levels of the ring states oscillate as function of the perpendicular magnetic field which are related to Aharonov-Bohm oscillations. Oscillations in the magnetic field dependence of the energy levels and the peaks in the magneto-optical spectrum emerge (disappear) as the ring states are formed (collapsed). The period and the amplitude of the oscillation decreases with the size of the MoS2_2 QDs.Comment: 11 pages, 9 figures, Accepted by Phys. Rev.

    X(1812) in Quarkonia-Glueball-Hybrid Mixing Scheme

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    Recently a JPC=0++J^{PC}=0^{++} (X(1812)) state with a mass near the threshold of ω\omega and ϕ\phi has been observed by the BES collaboration in J/ψγωϕJ/\psi \to \gamma \omega \phi decay. It has been suggested that it is a IG=0+I^G = 0^+ state. If it is true, this state fits in a mixing scheme based on quarkonia, glueball and hybrid (QGH) very nicely where five physical states are predicted. Together with the known f0(1370)f_0(1370), f0(1500)f_0(1500), f0(1710)f_0(1710), and f0(1790)f_0(1790) states, X(1812) completes the five members in this family. Using known experimental data on these particles we determine the ranges of the mixing parameters and predict decay properties for X(1812). We also discuss some features which may be able to distinguish between four-quark and hybrid mixing schemes.Comment: 15 pages, 2 figures, 3 table

    Molecular dynamics of folding of secondary structures in Go-type models of proteins

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    We consider six different secondary structures of proteins and construct two types of Go-type off-lattice models: with the steric constraints and without. The basic aminoacid-aminoacid potential is Lennard Jones for the native contacts and a soft repulsion for the non-native contacts. The interactions are chosen to make the target secondary structure be the native state of the system. We provide a thorough equilibrium and kinetic characterization of the sequences through the molecular dynamics simulations with the Langevin noise. Models with the steric constraints are found to be better folders and to be more stable, especially in the case of the β\beta-structures. Phononic spectra for vibrations around the native states have low frequency gaps that correlate with the thermodynamic stability. Folding of the secondary structures proceeds through a well defined sequence of events. For instance, α\alpha-helices fold from the ends first. The closer to the native state, the faster establishment of the contacts. Increasing the system size deteriorates the folding characteristics. We study the folding times as a function of viscous friction and find a regime of moderate friction with the linear dependence. We also consider folding when one end of a structure is pinned which imitates instantaneous conditions when a protein is being synthesized. We find that, under such circumstances, folding of helices is faster and of the β\beta-sequences slower.Comment: REVTeX, 14 pages, EPS figures included, JCP in pres
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