Search results for "Statistic"

Using Differential Geometry for Sparse High-Dimensional Risk Regression Models

2023

With the introduction of high-throughput technologies in clinical and epidemiological studies, the need for inferential tools that are able to deal with fat data-structures, i.e., relatively small number of observations compared to the number of features, is becoming more prominent. In this paper we propose an extension of the dgLARS method to high-dimensional risk regression models. The main idea of the proposed method is to use the differential geometric structure of the partial likelihood function in order to select the optimal subset of covariates.

Modélisation des objets historiques selon la fonction, l'espace et le temps pour l'étude des dynamiques urbaines dans la longue durée

2010

The proposed principle for understanding the urban fabric is based on considering the town as a set of complex objects, taking a systemic approach. The town system used to study the urban fabric over large time spans is composed of three sub-systems relating to historical objects from the level of the excavation to that of the former urban space: function (social use), space (location, surface area and morphology) and time (dating, duration and chronology). The historical object is the analytical unit of the space studied. The purposed model allows urban changes to be observed. The originality of this procedure lies in its approach whereby it is possible to start not from the mapping of a p…

Typology and Representation of Alterations in Territorial Units: A Proposal

2018

Abstract This article proposes a typology of boundary changes in territorial units at two points in time. The different types of changes are organized in a hierarchy and represented homogeneously, independently of the number of territorial units involved and of the changes to them. Each alteration is described precisely and unambiguously, and it is codified to allow the information to be treated automatically. In addition to providing efficient storage of the information about these changes, a canonical representation facilitates the automatic detection of inconsistencies in the database. At the same time, the typology allows us to define backward and forward equivalence rules, which helps …

Fuzzy sliding mode control design for a class of disturbed systems

2014

This paper discusses the problem of the fuzzy sliding mode control for a class of disturbed systems. First, a fuzzy auxiliary controller is constructed based on a feedback signal not only to estimate the unknown control term, but also participates in the sliding mode control due to the fuzzy rule employed. Then, we extend our theory into the cases, where some kind of system information can not be obtained, for better use of our theoretical results in real engineering. Finally, some typical numerical examples are included to demonstrate the effectiveness and advantage of the designed sliding mode controller. Refereed/Peer-reviewed

Strategical behaviours in French ambulatory care (a theoretical and empirical study)

1991

Specifying agency relationships between the different actors in ambulatory care - the patient, the physician, the insurance and public authorities - allows to render an account of the complexity and the specificity of the health system. After a presentation of the normative approach of the agency theory, we will focus on two agency relationships : the Relationship between the insurance and insured people and the relationship between the patient and the physician. The driving part of supply appears through the analysis of the relationship between the physician and the others : he is the agent of both the patient and public authorities. The issue is then the hypothesis of supplier induced dem…

An approach to hypothesis testing based on local indicators of spatio-temporal association

The detection of clustering structure in a point pattern is one of the major focus of attention in spatio-temporal data mining. For instance, statistical tools for clustering detection and identification of events belonging to clusters are welcome in epidemiology and seismology. Local second-order statistics can provide information on how an event relates to nearby events. We extend local indicators of spatial association (known as LISA functions) into the spatio-temporal context (which then will be called LISTA functions). These functions can be used for local tests in the context of case-control spatio-temporal point patterns, and are able to assess in the neighbourhood of each event if t…

Perceived threat or perceived benefit? Immigrants’ perception of how Finns tend to perceive them

2022

Research on how immigrants are perceived by locals has flourished extensively within the past decades. Through the lens of integrated threat theory and the threat benefit model, this study examines immigrants’ perceptions of how Finns tend to perceive them based on their lived experiences. In a sample of 103 immigrants from over 40 nationalities living in Finland, results indicate that overall, immigrants believe they are perceived more as a threat than a benefit to the Finnish society. Implications and opportunities for further research are discussed as well. peerReviewed

Turismo e social network. L'immagine della destinazione Sicilia nel passaparola di Facebook.

2014

DOTTOR DIVAGO Discernere, Valutare e Governare la Nuova Università

2008

Un indicatore composto della qualità della didattica: dalle scale ordinali alle metriche di importanza relativa.

2008

Il problema della ponderazione nella costruzione di un indicatore composto, pur essendo determinante per il valore della misura sintetica, non trova ancora risposte soddisfacenti nell’attuale panorama della letteratura dedicata all’argomento. Un tentativo per la costruzione di un sistema di pesi è effettuato sulla base di un modello di regressione lineare multipla attraverso misure di importanza relativa. In presenza di regressori correlati l’usuale output del modello di regressione non è adeguato per fornire tali misure. Si fa ricorso ai metodi per la scomposizione di R2 e, tra quelli riscontrati in letteratura, se ne esaminano due: LMG e PMVD. Questi ultimi, entrambi basati su medie degli…