Search results for " Regression"

2018

Objective: Supportive care needs in glioma patients often remain unrecognized, and optimization in assessment is required. First, we aimed at assessing the support needed using a simple structured questionnaire. Second, we investigated the psychosocial burden and support requested from caregivers. Methods: Patients were assessed at three centers during their outpatient visits. They completed the Distress Thermometer (DT; score ≥ 6 indicated significant burden in brain tumor patients), the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30+BN20, and the Patients' Perspective Questionnaire (PPQ) that assessed psychosocial distress as well …

Selection of the Best Subset of Variables in Regression and Time Series Models

2009

The problem of variable selection is one of the most pervasive model selection problems in statistical applications. Often referred to as the problem of subset selection, it arises when one wants to model the relationship between a variable of interest and a subset of potential explanatory variables or predictors, but there is uncertainty about which subset to use. Several papers have dealt with various aspects of the problem but it appears that the typical regression user has not benefited appreciably. One reason for the lack of resolution of the problem is the fact that it is has not been well defined. Indeed, it is apparent that there is not a single problem, but rather several problems …

Value, supplier dependence and long‐term orientation

2011

PurposeIn organizational markets, many companies tend to reduce the number of providers to focus on establishing relationships with few of them. The purpose of this paper is to analyze the influence of relationship value and dependence of supplier on long‐term orientation and customer loyalty in the setting of relationships between travel agencies and their main providers.Design/methodology/approachA partial least square regression is performed to test a proposed model that links several relational variables with outcomes in terms of customer loyalty.FindingsResults provide support for the positive indirect influence of relationship value on long‐term orientation, while customer dependence …

Assessing mental health therapeutic communities functioning

2019

Empirical and clinical evidence shows that therapeutic communities produce changes in people’s mental health and well-being. Treatment in communities has effects on improving interpersonal relationships, acceptance among members, ability to recognize other people’s feelings, symptomatology, life satisfaction and self-esteem. This paper aims to investigate which factors can explain the treatment effectiveness, measured by an index which incorporates the point of view of the communities staff members, by means of a beta regression model with random intercept. The results show the influence of some organizational dimension as well as staff roles, providing a meaningful insights into the functi…

FACTORS AFFECTING THE INFESTATION DUE TO BACTROCERA OLEAE (ROSSI) IN SEVERAL SICILIAN OLIVE CULTIVARS

2010

È possibile stimare le variazioni dei crediti di carbonio forniti dai suoli agricoli e forestali italiani

2011

L’Italia ha aderito al Protocollo di Kyoto, ma ha deciso di eleggere solo la gestione forestale nell’ambito delle attività addizionali previste per contabilizzare i crediti di carbonio. Lo scopo principale di questo lavoro è stato quello di dimostrare che è possibile stimare le variazioni del contenuto di carbonio organico dei suoli in Italia durante gli ultimi 3 decenni (dal 1979 al 2008) e contabilizzare i crediti di carbonio originati dalle attività di gestione sia agricola che forestale.

Past cover modulates the intense and spatially structured natural regeneration of woody vegetation in a pastureland

2020

Made available in DSpace on 2020-12-12T02:34:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Università degli Studi di Palermo Ministero dell’Istruzione, dell’Università e della Ricerca Vegetation natural regeneration after agricultural abandonment is changing the landscape patterns in many areas worldwide. However, the expansion rate, spatio-temporal dynamics, and the role of past vegetation cover in shaping such patterns are still barely quantified in fine and meso scales. Here, we aim to quantify the expansion rate and assess the spatio-temporal patterns and the effects of past cover on natural woody vegetation cover increase. We sampled woodland and shrubland cover from …

Earth-flow susceptibility assessment in the Marvello River basin (Sicily, Italy)

2014

In this study, statistical models of earth-flow susceptibility were prepared using logistic regression. The analyses were carried out in a small (51 km2) basin of western Sicily, where 1,376 earth-flows were identified. To predict the spatial distribution of the mapped landslides, outcropping lithology and seven topographic attributes were exploited as explanatory variables. Before calculating these variables, a reconstruction of the pre-failure topography was performed. To evaluate the predictive skill and the robustness of the models, two groups made of five random subsets of earth-flows and stable cells were prepared. Absences of the first group were selected as individual cells whereas …

Landform classification: a high-performing mapping unit partitioning tool for landslide susceptibility assessment—a test in the Imera River basin (no…

2022

In landslide susceptibility studies, the type of mapping unit adopted affects the obtained models and maps in terms of accuracy, robustness, spatial resolution and geomorphological adequacy. To evaluate the optimal selection of these units, a test has been carried out in an important catchment of northern Sicily (the Imera River basin), where the spatial relationships between a set of predictors and an inventory of 1608 rotational/translational landslides were analysed using the multivariate adaptive regression splines (MARS) method. In particular, landslide susceptibility models were prepared and compared by adopting four different types of mapping units: the largely adopted grid cells (PX…

КАРТА ПОДВЕРЖЕННОСТИ ОПОЛЗНЕВОЙ ОПАСНОСТИ ТЕРРИТОРИИ РАЙОНОВ ШИЛАТО И КАЛЬТАВУТУРО (СЕВЕРНАЯ СИЦИЛИЯ). Logistic regression method for landslides susc…

2012

The studied area is located within two Sicilian districts– Scillato and Caltavuturo. Studied area is 200 km2. This territory is affected by large landslides very strongly. In the course of the research these districts were divided into 2 million square units of 10 × 10 m. Values of landslide factors were assessed within each unit. Using method of logistic regression allowed us to select the most significant factors and to make the landslide susceptibility map. Landslide hazard analys was made with 3 models, which analyze different diagnostic areas (places, where landslides are trigger usually). The results indicate that the using of the buffer zone with radius 50 m around the highest point …