High-resolution asymptotics for the angular bispectrum of spherical random fields

In this paper we study the asymptotic behavior of the angular bispectrum of spherical random fields. Here, the asymptotic theory is developed in the framework of fixed-radius fields, which are observed with increasing resolution as the sample size grows. The results we present are then exploited in a set of procedures aimed at testing non-Gaussianity; for these statistics, we are able to show convergence to functionals of standard Brownian motion under the null hypothesis. Analytic results are also presented on the behavior of the tests in the presence of a broad class of non-Gaussian alternatives. The issue of testing for non-Gaussianity on spherical random fields has recently gained enormous empirical importance, especially in connection with the statistical analysis of cosmic microwave background radiation.Comment: Published at http://dx.doi.org/10.1214/009053605000000903 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Good Life in Old Age: Accommodating Elderly Patients\u27 Values and Motivations in the Thai Healthcare System

People over age sixty-five are the fastest growing segment of the population in most developed and developing nations and their healthcare problems are placing strains on healthcare systems. An added complication for healthcare providers is that elderly populations carry with them a variety of culturally-specific views surrounding the aging process, so it\u27s hard to standardize care for the elderly globally, and also within individual countries. Addressing cultural difference in gerontology policy and practice therefore requires defining aging well or a good life in old age in the eyes of the elderly. This study used Thailand\u27s healthcare system as a model to investigate how healthcare professionals accommodate elderly patients\u27 views, values and motivations surrounding a good life in old age,” as defined by both elderly patients and healthcare professionals. To do this, anthropological methods provided a means for exploring not only what patients\u27 views are, but also why they hold these views. Through use of open ended interviews and participant observation, this study aimed to discover how both current and future healthcare professionals can work to truly listen, and be sensitive, to patients\u27 individual needs and desires, in order to give patients the best care possible. I completed this research through the International Research Opportunities Program at the University of New Hampshire

Optimal ownership in joint ventures with contributions of asymmetric partners

This paper faces two questions concerning Joint Ventures (JV) agreements. First, we study how the partners contribution affect the creation and the profit sharing of a JV when partners' effort is not observable. Then, we see whether such agreements are easier to enforce when the decision on JV profit sharing among partners is either delegated to the independent JV management (Management Sharing) or jointly taken by partners (Coordinated Sharing). We find that the firm whose effort has a higher impact on the JV's profits should have a larger profit shares. Moreover, a Management sharing ensures, at least in some cases, a wider range of self-enforceable JV agreements.joint ventures, strategic alliances, ownership structure, asymmetries

Band Spectrum Regression for Cointegrated Time Series with Long Memory Innovations

Band spectrum regression is considered for cointegrated time series with long memory innovations. The estimates we advocate are shown to be consistent when cointegrating relationships among stationary variables are investigated, while OLS are inconsistent due to correlation between the regressor and the cointegrating residuals; in the presence of unit roots, these estimates share the same asymptotic distribution as OLS. As a corollary of the main result, we provide a functional central limit theorem for quadratic forms in nonstationary fractionally integrated processes.Long-range dependence, band spectrum regression, cointegration

Optimal ownership in joint ventures with contributions of asymmetric partners

This paper faces two questions concerning Joint Ventures (JV) agreements. First, we study how the partners contribution affect the creation and the profit sharing of a JV when partners' effort is not observable. Then, we see whether such agreements are easier to enforce when the decision on JV profit sharing among partners is either delegated to the independent JV management (Management Sharing) or jointly taken by partners (Coordinated Sharing). We find that the firm whose effort has a higher impact on the JV's profits should have a larger profit shares. Moreover, a Management sharing ensures, at least in some cases, a wider range of self-enforceable JV agreements.joint ventures, strategic alliances, ownership structure, asymmetries.

Optimal ownership in joint ventures with contributions of asymmetric partners

This paper faces two questions concerning Joint Ventures (JV) agreements. First, we study how the partners contribution affect the creation and the profit sharing of a JV when partners' effort is not observable. Then, we see whether such agreements are easier to enforce when the decision on JV profit sharing among partners is either delegated to the independent JV management (Management Sharing) or jointly taken by partners (Coordinated Sharing). We find that the firm whose effort has a higher impact on the JV's profits should have a larger profit shares. Moreover, a Management sharing ensures, at least in some cases, a wider range of self-enforceable JV agreements.D43, L13, L14, L22

Statistical challenges in the analysis of Cosmic Microwave Background radiation

An enormous amount of observations on Cosmic Microwave Background radiation has been collected in the last decade, and much more data are expected in the near future from planned or operating satellite missions. These datasets are a goldmine of information for Cosmology and Theoretical Physics; their efficient exploitation posits several intriguing challenges from the statistical point of view. In this paper we review a number of open problems in CMB data analysis and we present applications to observations from the WMAP mission.Comment: Published in at http://dx.doi.org/10.1214/08-AOAS190 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Some characterizations of the spherical harmonics coefficients for isotropic random fields

In this paper we provide some simple characterizations for the spherical harmonics coefficients of an isotropic random field on the sphere. The main result is a characterization of isotropic gaussian fields through independence of the coefficients of their development in spherical harmonics.Comment: 9 pages. Submitted June 200

High-frequency asymptotics for Lipschitz-Killing curvatures of excursion sets on the sphere

In this paper, we shall be concerned with geometric functionals and excursion probabilities for some nonlinear transforms evaluated on Fourier components of spherical random fields. In particular, we consider both random spherical harmonics and their smoothed averages, which can be viewed as random wavelet coefficients in the continuous case. For such fields, we consider smoothed polynomial transforms; we focus on the geometry of their excursion sets, and we study their asymptotic behaviour, in the high-frequency sense. We focus on the analysis of Euler-Poincar\'{e} characteristics, which can be exploited to derive extremely accurate estimates for excursion probabilities. The present analysis is motivated by the investigation of asymmetries and anisotropies in cosmological data. The statistics we focus on are also suitable to deal with spherical random fields which can only be partially observed, the canonical example being provided by the masking effect of the Milky Way on Cosmic Microwave Background (CMB) radiation data.Comment: Published at http://dx.doi.org/10.1214/15-AAP1097 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org