Selected Challenges From Spatial Statistics For Spatial Econometricians

Griffith and Paelinck (2011) present selected non-standard spatial statistics and spatial econometrics topics that address issues associated with spatial econometric methodology. This paper addresses the following challenges posed by spatial autocorrelation alluded to and/or derived from the spatial statistics topics of this book: the Gaussian random variable Jacobian term for massive datasets; topological features of georeferenced data; eigenvector spatial filtering-based georeferenced data generating mechanisms; and, interpreting random effects.Artykuł prezentuje wybrane, niestandardowe statystyki przestrzenne oraz zagadnienia ekonometrii przestrzennej. Rozważania teoretyczne koncentrują się na wyzwaniach wynikających z autokorelacji przestrzennej, nawiązując do pojęć Gaussowskiej zmiennej losowej, topologicznych cech danych georeferencyjnych, wektorów własnych, filtrów przestrzennych, georeferencyjnych mechanizmów generowania danych oraz interpretacji efektów losowych

Orbit categories, classifying spaces, and generalized homotopy fixed points

We give a new description of Rosenthal's generalized homotopy fixed point spaces as homotopy limits over the orbit category. This is achieved using a simple categorical model for classifying spaces with respect to families of subgroups.Comment: 10 pages. Version 4: various improvements to the exposition based on comments from the referee and edito

Operating LISA as a Sagnac interferometer

A phase-locking configuration for LISA is proposed that provides a significantly simpler mode of operation. The scheme provides one Sagnac signal readout inherently insensitive to laser frequency noise and optical bench motion for a non-rotating LISA array. This Sagnac output is also insensitive to clock noise, requires no time shifting of data, nor absolute arm length knowledge. As all measurements are made at one spacecraft, neither clock synchronization nor exchange of phase information between spacecraft is required. The phase-locking configuration provides these advantages for only one Sagnac variable yet retains compatibility with the baseline approach for obtaining the other TDI variables. The orbital motion of the LISA constellation is shown to produce a 14 km path length difference between the counter-propagating beams in the Sagnac interferometer. With this length difference a laser frequency noise spectral density of 1 Hz/$\sqrt{\rm Hz}$ would consume the entire optical path noise budget of the Sagnac variables. A significant improvement of laser frequency stability (currently at 30 Hz/$\sqrt{\rm Hz}$) would be needed for full-sensitivity LISA operation in the Sagnac mode. Alternatively, an additional level of time-delay processing could be applied to remove the laser frequency noise. The new time-delayed combinations of the phase measurements are presented.Comment: 8 pages, 2 figure

Online Video Contest Effects on Brand and Ad Attitudes

This research investigates how online video contests (OVCs) affect brand image, as measured by brand and advertisement attitudes. After conducting a pre-test to discover an appropriate product for the Generation Y target market, we ran an experiment examining OVCs, television, and magazine ad’s effects on multi-item measures of brand and advertisement attitudes. One hundred twenty-one subjects were randomly assigned to one of the three test conditions. The OVC significantly resulted in positive brand attitudes for the hedonic dimension such as feelings and attractiveness of the brand. For the more functional characteristics, OVCs did not influence brand attitudes. OVCs also produced positive advertising attitudes in terms of clarity, but other dimensions of advertising attitudes were unchanged. We also compared the OVC to the more traditional media of TV and magazines. OVCs produced more positive brand attitudes in terms of feelings than both TV and magazines. For the advertising attitude measure, OVCs produced significantly higher ratings than TV for feelings, attractiveness, and entertainment. There were no significant differences between OVCs and magazines for advertising attitudes. Our findings suggest that marketers can use OVCs effectively if the benefits of the product are hedonic in nature. Functional benefits may not prove as effective in enhancing OVC brand and ad attitudes. Marketers must determine their promotional goals before putting an OVC into practice