The Impacts of Retail Promotions on the Demand for Orange Juice: A Study of a Retail Chain

This study examined the impacts of retail promotions on the demand for five brands of orange juices for a retail chain (referred to as Retailer X) and its competitors using the Rotterdam model. Results show that the combination of feature ads and displays had the largest impacts on retail revenue among the four promotional tactics considered, while temporary price reductions had no additional advertising impacts other than price impacts on retail revenues. Results also show that when Retailer X promotes an OJ brand using any of the tactics studied, a larger portion of the increased demand for the promoted brand came from reduced demand for other brands of OJ in the same store and a smaller portion came from the decreased demand in competing stores in the same trading area.Demand and Price Analysis, Marketing,

Blockspin Cluster Algorithms for Quantum Spin Systems

Cluster algorithms are developed for simulating quantum spin systems like the one- and two-dimensional Heisenberg ferro- and anti-ferromagnets. The corresponding two- and three-dimensional classical spin models with four-spin couplings are maped to blockspin models with two-blockspin interactions. Clusters of blockspins are updated collectively. The efficiency of the method is investigated in detail for one-dimensional spin chains. Then in most cases the new algorithms solve the problems of slowing down from which standard algorithms are suffering.Comment: 11 page

Constraining the HI-Halo Mass Relation From Galaxy Clustering

We study the dependence of galaxy clustering on atomic gas mass using a sample of $\sim$16,000 galaxies with redshift in the range of $0.0025<z<0.05$ and HI mass of $M_{\rm HI}>10^8M_{\odot}$, drawn from the 70% complete sample of the Arecibo Legacy Fast ALFA survey. We construct subsamples of galaxies with $M_{\rm HI}$ above different thresholds, and make volume-limited clustering measurements in terms of three statistics: the projected two-point correlation function, the projected cross-correlation function with respect to a reference sample selected from the Sloan Digital Sky Survey, and the redshift-space monopole moment. In contrast to previous studies, which found no/weak HI-mass dependence, we find both the clustering amplitude on scales above a few Mpc and the bias factors to increase significantly with increasing HI mass for subsamples with HI mass thresholds above $10^9M_{\odot}$. For HI mass thresholds below $10^9M_{\odot}$, while the measurements have large uncertainties caused by the limited survey volume and sample size, the inferred galaxy bias factors are systematically lower than the minimum halo bias factor from mass-selected halo samples. The simple halo model, in which galaxy content is only determined by halo mass, has difficulties in interpreting the clustering measurements of the HI-selected samples. We extend the simple model by including the halo formation time as an additional parameter. A model that puts HI-rich galaxies into halos that formed late can reproduce the clustering measurements reasonably well. We present the implications of our best-fitting model on the correlation of HI mass with halo mass and formation time, as well as the halo occupation distributions and HI mass functions for central and satellite galaxies. These results are compared with the predictions from semi-analytic galaxy formation models and hydrodynamic galaxy formation simulations.Comment: Accepted for publication in ApJ. The 2PCF measurements are available at http://sdss4.shao.ac.cn/guoh

Coherent population trapping and dynamical instability in the nonlinearly coupled atom-molecule system

We study the possibility of creating a coherent population trapping (CPT) state, involving free atomic and ground molecular condensates, during the process of associating atomic condensate into molecular condensate. We generalize the Bogoliubov approach to this multi-component system and study the collective excitations of the CPT state in the homogeneous limit. We develop a set of analytical criteria based on the relationship among collisions involving atoms and ground molecules, which are found to strongly affect the stability properties of the CPT state, and use it to find the stability diagram and to systematically classify various instabilities in the long-wavelength limit.Comment: 11 pages, 8 figure

Adiabatic Fidelity for Atom-Molecule Conversion in a Nonlinear Three-Level \Lambda-system

We investigate the dynamics of the population transfer for atom-molecule three-level $\Lambda$-system on stimulated Raman adiabatic passage(STIRAP). We find that the adiabatic fidelity for the coherent population trapping(CPT) state or dark state, as the function of the adiabatic parameter, approaches to unit in a power law. The power exponent however is much less than the prediction of linear adiabatic theorem. We further discuss how to achieve higher adiabatic fidelity for the dark state through optimizing the external parameters of STIRAP. Our discussions are helpful to gain higher atom-molecule conversion yield in practical experiments.Comment: 4 pages, 5 figure

Corrections to Scaling for the Two-dimensional Dynamic XY Model

With large-scale Monte Carlo simulations, we confirm that for the two-dimensional XY model, there is a logarithmic correction to scaling in the dynamic relaxation starting from a completely disordered state, while only an inverse power law correction in the case of starting from an ordered state. The dynamic exponent $z$ is $z=2.04(1)$.Comment: to appear as a Rapid commu. in Phys. Rev.

Emergence of Global Preferential Attachment From Local Interaction

Global degree/strength based preferential attachment is widely used as an evolution mechanism of networks. But it is hard to believe that any individual can get global information and shape the network architecture based on it. In this paper, it is found that the global preferential attachment emerges from the local interaction models, including distance-dependent preferential attachment (DDPA) evolving model of weighted networks(M. Li et al, New Journal of Physics 8 (2006) 72), acquaintance network model(J. Davidsen et al, Phys. Rev. Lett. 88 (2002) 128701) and connecting nearest-neighbor(CNN) model(A. Vazquez, Phys. Rev. E 67 (2003) 056104). For DDPA model and CNN model, the attachment rate depends linearly on the degree or strength, while for acquaintance network model, the dependence follows a sublinear power law. It implies that for the evolution of social networks, local contact could be more fundamental than the presumed global preferential attachment. This is onsistent with the result observed in the evolution of empirical email networks.Comment: 9 pages, 5 figure

Are Fruit Juice Categories Separable?

Supermarket shelves are saturated with numerous varieties and brands of juice beverages. This high level of assortment has dramatically changed beverage consumption patterns and trends throughout the United States. In fact, during 2004-2005, energy and sport drinks experienced significant increases in sales, 65.9% and 20.6 %, respectively. During the same period of time, refrigerated juice sales increased a mere 2.2%, shelved non-fruit drinks decreased 0.9%, bottled juices and cocktails both decreased 1.5 % and frozen juice decreased by 12.8% (Food Industry Review 2006). The beverage industry has undergone many transformations, but consumer theory states that a shift in demand for one good has to be compensated by a shift in the opposite directions in the demand for the other good. Thus, with more brands competing for consumers’ dollars, it is important for brand managers, retailers, and other industry officials to understand demand interrelationships among various beverages. This study examines the competitiveness and structure of the beverage industry. Existing research suggests the demand for fruit beverages is independent from other food and non-food groups (Heien 1982; Lee 1984); therefore, information pertaining to other goods can be omitted without compromising the validity of the study. Our study will allow us to better understand how consumers make decisions concerning purchases patterns of beverage expenditures.Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,