Browsing by Author "González, Felipe"

Now showing 1 - 9 of 9
  • No Thumbnail Available
    Item
    A combined destination and route choice model for a bicycle sharing system
    (2016) González, Felipe; Melo Riquelme, C.; Grange Concha, Louis de; CEDEUS (Chile)
    This paper studies the supply variables that influence the destination and route choices of users of a bicycle sharing system in the Chilean city of Santiago. A combined trip demand logit model is developed whose explanatory variables represent attributes relating to the topology of the possible routes and other characteristics such as the presence of bikeways, bus service and controlled intersections. The data for the explanatory variables and system users were collected through field surveys of the routes and interviews conducted at the system stations. The results of the model show that proximity to stops on the Santiago Metro and the existence of bikeways are the main factors influencing destination and route choices. Also indicated by the model estimates are gender differences, a preference for tree-lined routes and an avoidance of routes with bus services. Finally, the outcomes reveal considerable potential for the integration of bicycle sharing systems with Metro transit.
  • Thumbnail Image
    Item
    A Maximum Entropy Fixed-Point Route Choice Model for Route Correlation
    (2014) De Grange, Louis; Raveau Feliú, Sebastián; González, Felipe
  • Thumbnail Image
    Item
    A polarized logit model
    (2013) De Grange, Louis; González, Felipe; Vargas Cucurella, Ignacio Tomás; Muñoz Abogabir, Juan Carlos; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Aggregate estimation of the price elasticity of demand for public transport in integrated fare systems : the case of Transantiago
    (2013) De Grange, Louis; González, Felipe; Muñoz Abogabir, Juan Carlos; Troncoso, Rodrigo; CEDEUS (Chile)
  • Thumbnail Image
    Item
    An Improved Stirling Approximation for Trip Distribution Models
    (2014) De Grange, Luis; González, Felipe; Muñoz Abogabir, Juan Carlos; Raveau Feliú, Sebastián
  • No Thumbnail Available
    Item
    Estimates of price elasticity of demand for urban freeway use with high-frequency control variables: the case of Santiago, Chile
    (2015) Grange Concha, Louis de; González, Felipe; Troncoso, R.; CEDEUS (Chile)
    Estimates are presented of toll and fuel price elasticities of demand for urban freeway use in Santiago, Chile. High-frequency toll and vehicle data were collected from four urban freeways for different route segments and times of day. Estimation was performed using log-linear regression models whose explanatory variables were tolls, fuel prices, city traffic levels and sets of dichotomous variables to control for daily, weekly and monthly seasonality. City traffic is a high frequency control of the activity level of the city. The elasticities to changes in tolls and fuel were all low in absolute value. The toll elasticities were below 0.05 for two freeways and 0.16 for the third, while for the fourth, which had more alternative routes, it was 0.47. The fuel price elasticities were also heterogeneous, with values of approximately 0.45 for two freeways and 0.21 for the third whereas for the fourth, which had the fewest alternatives, it was 0.07.
  • Thumbnail Image
    Item
    Is acyclovir effective for the treatment of varicella in children and adolescents?
    (2018) González, Felipe; Rojas González, Pamela
  • No Thumbnail Available
    Item
    JUE insight: Efficiency of bus priority infrastructure
    (2025) González, Felipe; Silva Montalva, Hugo Emilio
    We use bus GPS data across 500 routes to estimate the impact of priority infrastructure on buses’ speed and ridership in Chile. Almost 100 million bus trips allow us to leverage within-route variation in the proportion of the route in which buses travel along bus lanes or Bus Rapid Transit (BRT) corridors. Corridors increase bus speeds by 20% at peak hours. Bus lanes, often seen as an equally effective but cheaper alternative to a BRT corridor, are, on average, ineffective. However, bus lanes achieve the same travel time savings as BRT corridors only when fully isolated from private vehicles, coupled with monitoring cameras and enforcement.
  • No Thumbnail Available
    Item
    Long-term mortality of coronavirus disease 2019 critically ill patients that required percutaneous tracheostomy in Chile: A multicenter cohort study
    (Wolters Kluwer Health, Inc., 2024) Ulloa Morrison, Rodrigo; Escalona, José; Navarrete, Pablo; Espinoza, Javiera; Bravo Morales, Sebastián Ignacio; Pastore Thomson, Antonia; Reyes, Sebastián; Bozinovic, Milan; Abbott, Francisco; Pairumani, Ronald; Noguera, Roselyn; Vera Alarcón, María Magdalena; González, Felipe; Valle, Felipe; Bakker, Jan; Bugedo Tarraza, Guillermo; Kattan Tala, Eduardo José
    Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to mechanical ventilation (MV) in approximately 20% of hospitalized patients. Tracheostomy expedites weaning of respiratory support. Moreover, there is a paucity of data regarding long-term outcomes of tracheostomized coronavirus disease 2019 (COVID-19) patients. The objective of this study was to describe 1-year mortality in a cohort of COVID-19 critically ill patients who required percutaneous tracheostomy in Chile and to assess the impact of age on outcomes. Methods: A multicenter prospective observational study was conducted in 4 hospitals in Chile between March 2020 and July 2021. Patients with confirmed SARS-CoV-2 infection connected to MV and required percutaneous tracheostomy were included. Baseline data, relevant perioperative and long-term outcomes, such as 1-year mortality, MV duration, intensive care unit (ICU), and hospital length of stay were registered. Patients were dichotomized according to age group (< and ≥ 70 years). Univariate and multivariate logistic regressions were performed to identify predictors of 1-year mortality. Results: Of 1319 COVID-19 ventilated critically ill patients, 23% (304) required a percutaneous tracheostomy. One-year mortality of the study group was 25% (20.2%-30.3%). ICU and hospital length of stay (LOS) were of 37 (27-49) and 52 (40-72) days. One-year mortality was higher in patients ≥ 70 years (36.9% vs. 21.2%, P = 0.012). Multivariate analysis confirmed age and baseline sequential organ failure assessment (SOFA) score as independent predictors, while time from intubation to tracheostomy was not. Conclusion: In COVID-19 critically ill patients who required percutaneous tracheostomy in Chile, the 1-year mortality rate was 25%, with a relevant impact of age on outcomes. An appropriate patient selection likely accounted for the low mortality rate. Future studies should confirm these results.