Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics

We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gr\"obner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular designs. For the purpose of analysis of data from fractional factorial designs, the techniques of Markov bases allow us to handle discrete observations. Thus the approach of computational algebraic statistics greatly enlarges the scope of fractional factorial designs.Comment: 16 page

Eksédra 2008

Il volume affronta temi relativi al disegno, al rilievo ed alla progettazione architettonica

Exploring the Potential of Urban Coastal Interfaces for Socio-Environmental Connections: The Cases of Marseille and Naples

Contemporary coastal cities intertwine variegated stakes, linked to the economic, productive and social functions of the seashore, and need a correct management aimed at balancing the different needs and at maintaining a high ecological status of the coasts themselves. A fracture emerges between the urban development of coastal areas and the social desire and expectations of the 'urban coastal society', a community intimately connected to the coast and sea elements. Port and productive evolution has often neglected the socio-recreational component inherent in coastal areas, related to its attractiveness for citizens, the presence of natural qualities and an undeniable visual and perceptual value that influence the use of these places, influencing the conformation of coastal public spaces. The integrity of the urban coasts appears fragmented by the juxtaposition of variegated elements which can however be considered as pieces of a potential green-blue infrastructure, with a view to recomposing the city-sea interface. The contribution aims to investigate the management and design criticalities that affect urban blue spaces, mainly in relation to the implications related to leisure and sociality, proposing a historical, spatial and socio-perceptive comparison between Naples and Marseille

Computational algebraic methods in efficient estimation

A strong link between information geometry and algebraic statistics is made by investigating statistical manifolds which are algebraic varieties. In particular it it shown how first and second order efficient estimators can be constructed, such as bias corrected Maximum Likelihood and more general estimators, and for which the estimating equations are purely algebraic. In addition it is shown how Gr\"obner basis technology, which is at the heart of algebraic statistics, can be used to reduce the degrees of the terms in the estimating equations. This points the way to the feasible use, to find the estimators, of special methods for solving polynomial equations, such as homotopy continuation methods. Simple examples are given showing both equations and computations. *** The proof of Theorem 2 was corrected by the latest version. Some minor errors were also corrected.Comment: 21 pages, 5 figure

Heart involvement in Rheumatoid Arthritis: Systematic review and meta-analysis.

OBJECTIVE: The aim of our study was to conduct a systematic review with meta-analysis of the current case-control studies about the valvular and pericardial involvement in patients with Rheumatoid Arthritis (RA), asymptomatic for cardiovascular diseases. METHODS: Case-control studies were identified by searching PubMed (1975-2010) and the Cochrane Central Register of Controlled Trials (CENTRAL) (1975-2010). Participants were adult patients with RA asymptomatic for cardiovascular diseases, and the outcome measure was the presence of cardiac involvement. RESULTS: Quantitative synthesis included 10 relevant studies out of 2326 bibliographic citations that had been found. RA resulted significantly associated to pericardial effusion (OR 10.7; 95% CI 5.0-23.0), valvular nodules (OR 12.5; 95% CI 2.8-55.4), tricuspidal valve insufficiency (OR 5.3; 95% CI 2.4-11.6), aortic valve stenosis (OR 5.2; 95% CI 1.1-24.1), mitral valve insufficiency (OR 3.4; 95% CI 1.7-6.7), aortic valve insufficiency (OR 1.7; 95% CI 1.0-2.7), combined valvular alterations (OR 4.3; 95% CI 2.3-8.0), mitral valve thickening and/or calcification (OR 5.0; 95% CI 2.0-12.7), aortic valve thickening and/or calcification (OR 4.4; 95% CI 1.1-17.4), valvular thickening and/or calcification (OR 4.8; 95% CI 2.2-10.5), and mitral valve prolapse (OR 2.2; 95% CI 1.2-4.0). CONCLUSIONS: Our systematic review pointed out the strength and the grade of both pericardial and cardiac valvular involvement in RA patients. Our findings underscore the importance of an echocardiographic assessment at least in clinical research when RA patients are involved. Moreover, further research is needed to understand the possible relationship of our findings and the increased cardiovascular mortality

Nonparametric Information Geometry

The differential-geometric structure of the set of positive densities on a given measure space has raised the interest of many mathematicians after the discovery by C.R. Rao of the geometric meaning of the Fisher information. Most of the research is focused on parametric statistical models. In series of papers by author and coworkers a particular version of the nonparametric case has been discussed. It consists of a minimalistic structure modeled according the theory of exponential families: given a reference density other densities are represented by the centered log likelihood which is an element of an Orlicz space. This mappings give a system of charts of a Banach manifold. It has been observed that, while the construction is natural, the practical applicability is limited by the technical difficulty to deal with such a class of Banach spaces. It has been suggested recently to replace the exponential function with other functions with similar behavior but polynomial growth at infinity in order to obtain more tractable Banach spaces, e.g. Hilbert spaces. We give first a review of our theory with special emphasis on the specific issues of the infinite dimensional setting. In a second part we discuss two specific topics, differential equations and the metric connection. The position of this line of research with respect to other approaches is briefly discussed.Comment: Submitted for publication in the Proceedings od GSI2013 Aug 28-30 2013 Pari

Patient satisfaction and food waste in obstetrics and gynaecology wards

Introduction: Patient satisfaction is an indicator of healthcare quality, and expectation is an important determinant. A component of patient satisfaction is the quality of foodservice. An indicator of this quality is the food wasted by hospitalised patients. In the present study, we investigated patient satisfaction regarding food and foodservice, the expectation on food quality and the amount of food wasted in two obstetrics and gynaecology wards in Northern and Southern Italy. Patients and Methods: A questionnaire, including sociodemographic data, rate of food waste, expectations of food quality and characteristics of food and foodservice, was admini-strated to 550 inpatients in obstetrics and gynaecology wards (275 for each hospital). Univariate analysis was performed to describe the results, and multivariate analysis was carried out to control for sociodemographic data. Results: Northern patients were more satisfied with the quality of food (54.2% vs 36.0%) and foodservice (54.5% vs 38.2%) than southern patients. Northern patients had more positive expectations about the quality of food (69.5% vs 31.6%), whereas southern patients stated that they had no expectations. Southern patients gave more importance to mealtime (72.7% vs 26.2%), and many of them brought food from home to the hospital (30.2% vs 2.2%) through relatives who came to visit them. Southern patients discarded about 41.7% of food served, whereas northern patients discarded only about 15.3%. Discussion: Food waste is a worldwide problem due to its economic, social and environmental effects. Especially in hospitals, food waste could have a negative impact on the overall patient satisfaction

Near-field light emission from semiconductor macroatoms

We present a microscopic theoretical analysis of time and spatially resolved photoluminescence of naturally occurring quantum dots induced by monolayer fluctuations in the thickness of semiconductor quantum wells. In particular we study the carrier dynamics and the emission properties of a semiconductor quantum dot under both continuous-wave and pulsed excitations resonant with the barrier energy levels. We show that collection-mode near-field optical microscopy allows the detection of light emission from excitonic dark states. We find that, at low temperature, the second (dark) energy level displays a carrier density significantly larger than that of the lowest energy level. This behaviour is a consequence of carrier trapping due to the symmetry-induced suppression of radiative recombination