3,210 research outputs found
Anticonvulsant prophylaxis in patients with brain neoplasms
No full textWhat is the evidence regarding anticonvulsant prophylaxis in people with brain neoplams? Miriam Cappelli, Simone Piazza and Jonathan Koffman present the results of a limited systematic literature review
On the choice of splitting rules for model-based trees for ordinal responses
No full textThe focus of the contribution is on the splitting criterion for model-based treeprocedure based on the class ofCUBmixture models for the analysis of ordinal scores. Theflexibility of the chosen modelling framework allows to select the splitting criterion to growthe tree according to the purposes of the study and the available data. In particular, theselection of variables yielding to the best partitioning results can be driven by fitting measuresor classical likelihood and deviance measures. The contribution proposes to investigate thefeatures of the available decision rules by a set of Montecarlo experiments, thus implicitlyfacing the problem of selecting the model-based tree to obtain an adequate and satisfyingoverview of response profiles
Infrastrutture ferroviarie secondarie e rigenerazione del territorio
No full textIl progetto di ricerca intende fornire un contributo innovativo alla pianificazione regionale dei trasporti, in un’ottica di smart system regional railway.
L’efficacia del trasporto regionale esistente s’inserisce in una visione sostenibile del trasporto collettivo, dove la coscienza ambientale e la necessità di intervenire sul territorio hanno stimolato e consolidato l’importanza di una connessione tra la pianificazione territoriale e la pianificazione dei trasporti.
Il concentrarsi sullo studio della rete ferroviaria esistente, e non sull’ampliamento o sulla costruzione di nuove infrastrutture, è dato dal fatto che le politiche hanno indirizzato il loro intervento sul potenziamento e sulla riqualificazione dell’esistente.
L’obiettivo del progetto di ricerca è quindi ottimizzare il trasporto regionale ferroviario esistente dismesso o abbandonato andando a riqualificarlo e potenziarlo (aumento della qualità e della quantità dell’offerta) in territori dove il volume di domanda attuale non giustifica tali interventi, ma che in un futuro prossimo fungeranno da motori per lo sviluppo locale.
Fondamentale sarà l’accessibilità e la mobilità collettiva con un sistema di trasporto intermodale e innovativo, che attraverso una pianificazione regionale possa permettere di ottenere un miglioramento della qualità di vita del cittadino.
La ricerca si è concentrata sullo studio del rapporto tra pianificazione dei trasporti e pianificazione territoriale, ponendo come vincolo lo sfruttamento delle infrastrutture ferroviarie esistenti a livello regionale italiano, andando a definire dei piani di sviluppo economicamente sostenibili.
Avvalendosi della ricerca bibliografica svolta si sono selezionati i casi studio su cui poi si sviluppata la ricerca:
• La linea ferroviaria regionale dismessa Civitavecchia-Orte su cui poi è stato applicato il nuovo modello;
• La linea ferroviaria attiva Civitavecchia-Roma, linea che durante il suo periodo di vita ha subito potenziamenti sotto il punto di vista gestionale;
• La linea ferroviari attiva Roma-Cesano-Viterbo, linea che ha e sta subendo forti potenziamenti sia a livello gestionale che infrastrutturale.
I casi studio selezionati si trovano tutti nella Regione Lazio, questa coincidenza è voluta e necessaria per cercare di avere un dato più omogeneamente similare.
Successivamente si è svolto un corposo lavoro di rappresentazione cartografica delle linee e di tutti gli edificati presenti nelle vicinanze delle linee selezionate per l’analisi.
Terminata questa prima fase di rappresentazione e conoscenza del territorio e delle sue infrastrutture si sono selezionati e applicati ai tre casi studio, con particolare comprensione e attenzione al rapporto tra densità territoriale (residenziale, produttiva, etc.) e prestazioni (attese o possibili) del trasporto ferroviario (sistemi regionali), diversi indicatori/indici territoriali e trasportistici.
Ultimo passaggio si sono confrontati i risultati ottenuti avvalendosi inoltre di un ulteriore indicatore di analisi cioè la variazione del valore immobiliare rispetto all’efficienza dell’infrastruttura ferroviaria.
Una volta identificati tutti gli indicatori ci si è concentrati sullo studio del sistema ferroviario regionale Civitavecchia-Orte, ponendo l’attenzione sull’individuazione delle criticità, sulla densità territoriale e sul rapporto della stessa con il sistema di trasporto collettivo ferroviario.
Le analisi sono state eseguite tramite l’utilizzo del software GIS con cui si è andato ad analizzare la linea ferroviaria riportando in planimetria tutti gli edificati regolari e non del comune di riferimento e disegnando le infrastrutture stradali e ferroviarie esistenti. Inoltre, sono stati riportati anche i sistemi di verde e le maggiori destinazioni d’uso del territorio.
L’ambito di studio si è concentrato sul territorio attraversato fisicamente dal tracciato ferroviario ed è stato suddiviso in quadranti di 1 km2 per poter svolgere le analisi, rapportandole alla distanza pedonale percorribile in maniera agevole.
La scelta di lavorare sulla Civitavecchia-Orte vuole dimostrare come un tracciato regionale possa influenzare e direzionare lo sviluppo territoriale.
La novità introdotta è stata quella di distaccarsi dai classici modelli valutativi e dal fattore domanda di trasporto, infatti il modello logico matematico consiste nel voler aumentare l’offerta di trasporto collettivo come elemento di input ad uno sviluppo territoriale che possa giustificare e costituire una domanda potenziale di mobilità introducendo all’interno del suo processo valutativo, dei indicatori non consueti
Rozpor ako východisko, láska ako smer u Simone Weilovej (Contradiction as base, Love as direction in writings of Simone Weil)
No full textArticle is explaining contradiction and love, Simone Weil‘s essential terms of hermeneutics of human Being. It introduces close relation of these terms with her understanding of God as well as with her overall concept of religion. Author also mentions Simone Weil‘s inspirations with philosophical and spiritual concepts of the East
LCA Sensitivity Analysis of an Energy-Biochar Chain from an Italian Gasification Plant: Environmental Trade-offs Assessment
No full textDue to its potential applications in bioenergy production, coproducts (bio-oil and syngas), mitigation of global warming, sustainable agriculture, pollutant removal, and other uses, biochar has drawn interest from all over the world. Producing and using soil-based biochar as a method of carbon sequestration could help reduce emissions while benefiting the soil and opening up possibilities for bioenergy production. However, to characterize the production cycle’s environmental and energy loads and confirm all of the advantages of biochar, Life Cycle Assessment (LCA) represents a reliable tool for evaluation. This work is based on continuing the study of Marzeddu and Cappelli (Marzeddu, Cappelli, et al., 2021) to understand the environmental impact of an energy-biochar chain involving a gasification plant in Italy. In the LCA carried out in the previous paper for the characterization of biochar, which is used as a soil conditioner, soil carbon sequestration, nitrous oxide emissions, fertilizer use, and water use for irrigation were considered. The results showed that the use of gasification for energy and biochar is an attractive strategy for mitigating the environmental impact analysis, especially climate change, with a net decrease of about ‒8.3·103 kg CO2, eq. The previous study was lacking a sensitivity analysis. For this reason, a sensitivity analysis is proposed in this study to consistently assess the environmental trade-offs of the biochar and the amended soil. In specific for the upstream processes the sensitivity is addressed to the selection of a different type of woodchips, for the core process in terms of selection of different packing material, and to the entire cradle-to-grave perspective by improving the logistics of the transportation, the distances within the supply chain and the choice of BAT technology for the transportation vehicles. This study highlights strategic research developments that combine to find potential environmental trade-offs and thresholds towards using biochar and its final use as a soil conditioner
Modelling marginal ranking distributions: the uncertainty tree
No full textIn this paper a novel approach is proposed for ranking data analysis that is based on marginal distributions. The marginal scores for one of the items to be ranked can be considered as a proxy of preference ratings and thus they can be employed to investigate drivers of the outcome. The rationale is that a model for the univariate marginal distributions should suitably convey information about the veracity of ordinal scores given that it would disregard the ranking constraints. The method relies on CUBREMOT (CUB REgression MOdel Trees), a tool for growing trees for ordinal resposes based on the local estimation of CUB models, a class of models able to explain both preferences and related uncertainty. Here we propose the Uncertainty Tree to disclose preference patterns on the basis of the model uncertainty component. Two applications on real data are discussed; comparison with other model-based trees is provided and a synthetic index for the selection of the best CUBREMOT is also advanced
CUBREMOT: A tool for building model-based trees for ordinal responses
No full textThe paper introduces a new technique for growing trees for ordinal responses in the model-based framework. We consider the class of CUB mixtures which is particularly appropriate to model perceptions and evaluations, as it designs the response process as the combination of a personal feeling and an inherent uncertainty. In our proposal, the partitioning process is based on the local estimation of CUBregression models to profile responses according to feeling and uncertainty conditional to the splitting variables. In this regard, two alternative splitting criteria are introduced featuring both inferential and fitting issues. Moreover, the chosen modelling framework allows for advantageous visualization of the classification results. The proposal is illustrated using real data from a survey conducted by the Italian National Statistical Office, with focus on perceived trust towards the European Parliament. A benchmark study is conducted to settle the proposal among the available tree methods for ordinal responses
“I beg you to tell me what has become of Djamila”: The Political Mobilization of Simone de Beauvoir’s Readers During the Boupacha Affair
No full textBy Sophia Millman This is a condensed version of a Masters thesis dedicated to the political mobilization of Simone de Beauvoir’s readers. The citations from the letters were translated from French by the author. *** On June 2, 1960, the French government ordered all copies of the daily Algiers edition of Le Monde seized and destroyed to suppress the publication of Simone de Beauvoir’s article “Pour Djamila Boupacha.” Beauvoir, a self-professed “woman of letters”, not “of action[1]”, and one ..
CUB model trees for ordinal response: preliminary results
No full textestimate a CUB models within the framework of tree based
methods in order to provide a tool for growing trees for ordinal responses
in which every node is associated with a CUB regression mode
On the choice of a model-based tree for ordinal scores
No full textOrdinal responses in the form of ratings arise frequently in social sciences, marketing and business applications where preferences, opinions and perceptions play a major role. Main examples concern customers/users' satisfaction analysis where it is common to collect rater's evaluation on a hedonic scale, along with a set of covariates (both categorical and quantitative) that characterize the respondent and/or the item/service. In this framework, the ordinal nature of the response has to be properly taken into account when the interest is in the understanding of different response patterns in terms of subjects' covariates. In this spirit, a model-based tree procedure for ordinal scores is illustrated: its structure is based on a class of mixture models for ordinal rating data that implies a twofold analysis in terms of feeling and uncertainty and effective graphical visualization of results. The flexibility of the chosen modelling framework entails that the splitting criterion can be customized according to the purposes of the study and the available data, without disregarding
uncertainty. Thus, the selection of variables yielding to the best partitioning results is driven by fitting measures or classical likelihood and deviance measurements, for instance. The contribution proposes to investigate the features of varying decision rules and thus implicitly addresses the problem of selecting the model-based tree that provides the most adequate and satisfying overview of response profiles. Comparison with alternative model-based approaches is also outlined
- …
