Search results for "Statistic"
showing 10 items of 12520 documents
Automatic Identification System data - potential resource for marine vessels drift studies in the Baltic Sea
2020
Automatic Identification System (AIS) has been employed for increasing the safety at the sea. Nowadays general information about the marine traffic can be tracked in operational mode using www.marinetraffic.com web portal. Additional information can be purchased for commercial and research purposes. Our study highlights a possibility to study the drift using an additional information available at www.marinetraffic.com - selected data on vessel position during its status “not under command”, which corresponds to the drifting vessels. Trajectories of the drift from AIS have been compared with mathematically modeled point-wise drifter paths. Copernicus Marine Environmental Monitoring Service's…
Micro and Macro Resilience Measures of an Economic Crisis
2020
Using Italian Households Budget Survey data over the period 1997-2013, a Cragg model in a life-cycle context is specified to compare the consumption behaviour in the pre- and post-crisis time and develop different micro and macro measures of resilience against crisis shocks. Cohort profiles for participation in and for consumption of tourism services in the pre- and post-crisis time are determined so as to explore the households’ resilience by generations. Next, the households’ resilience according to socio-demographic characteristics is addressed. As for the macro-resilience, combining individual expenditure elasticity, we examine whether and how Italian regions have responded to the recen…
Operational and financial performance of Italian airport companies: A dynamic graphical model
2016
Abstract This paper provides evidence on the relationship within a set of financial and operational indicators for Italian airports over 2008–2014. The limited sample size of national and regional airports suggests to apply the penalised RCON ( V , E ) model, which falls within the class of Gaussian graphical models. It provides both estimate and easy way to visualise conditional independence structures of the variables. Moreover, it is particularly suitable for handling longitudinal data where small number of units and huge number of variables have been collected. Findings highlight that a qualified concept of size matters in determining good financial performance. Specifically, increasing…
Connotative meaning of travel modes and activity-travel behavior
2018
Abstract This paper aims to present results of a study regarding how the meaning of travel modes influences on the performance of activities and trips. Connotative meaning of travel modes was measured using semantic differential scales, which collect the suggestive significance of the terms used to name current travel modes. More than 400 people provided that information together with values and other types of attitudes, characteristics of their usual companions, socio-demographics, and 2-days activity-travel diary that includes a weekend day and a weekday. Descriptive analysis, which include frequency distributions, Factor Analysis, and correlations, have been developed to find potential r…
Measuring situations that stress Mexicans while driving
2016
The purpose of this paper is to construct a scale that will help determine the aspects involved in driving a motor vehicle that influence the levels of stress in a human being. Two complementary studies were conducted: the first one determined, by qualitative methods, the aspects of driving that 103 participants found most stressful whilst driving; the second was a validation of the scale constructed with said information on 295 participants (142 males, 153 females, age mean 37.41, std. dev. 14.008). The scale included 22 situations that were then evaluated on a Likert scale to assess the level of stress they evoke. These items were arranged on 3 factors, and descriptive statistics were com…
The Split Delivery Vehicle Routing Problem with Time Windows and Customer Inconvenience Constraints
2019
In classical routing problems, each customer is visited exactly once. By contrast, when allowing split deliveries, customers may be served through multiple visits. This potentially results in substantial savings in travel costs. Even if split deliveries are beneficial to the transport company, several visits may be undesirable on the customer side: At each visit the customer has to interrupt his primary activities and handle the goods receipt. The contribution of the present paper consists in a thorough analysis of the possibilities and limitations of split delivery distribution strategies. To this end, we investigate two different types of measures for limiting customer inconvenience (a m…
Spatial analysis of traffic accidents near and between road intersections in a directed linear network.
2019
Although most of the literature on traffic safety analysis has been developed over areal zones, there is a growing interest in using the specific road structure of the region under investigation, which is known as a linear network in the field of spatial statistics. The use of linear networks entails several technical complications, ranging from the accurate location of traffic accidents to the definition of covariates at a spatial micro-level. Therefore, the primary goal of this study was to display a detailed analysis of a dataset of traffic accidents recorded in Valencia (Spain), which were located into a linear network representing more than 30 km of urban road structure corresponding t…
Multivariate modeling and analysis of regional ocean freight rates
2018
Abstract In this paper, we propose a new multivariate model for the dynamics of regional ocean freight rates. We show that a cointegrated system of regional spot freight rates can be decomposed into a common non-stationary market factor and stationary regional deviations. The resulting integrated CAR process is new to the literature. By interpreting the common market factor as the global arithmetic average of the regional rates, both the market factor and the regional deviations are observable which simplifies the calibration of the model. Moreover, forward contracts on the market factor can be traded in the Forward Freight Agreement (FFA) market. We calibrate the model to historical spot r…
Assessing cruise port of call performance: a passenger-based approach using PLS modelling
2017
ABSTRACTIn the present context of booming cruise demand, the study aims to advance the knowledge on port of call performance from cruise passengers’ perspective. The aim of this investigation was twofold: (1) to examine the structural links among port of call perceived quality–satisfaction–future intentions (revisit and word-of-mouth (WOM) behaviour); and (2) to test the moderating effect of cruisers’ motivation (push versus pull factors) to visit the port of call on the proposed structural links. Partial least squares path modelling was used to test the proposed model with a sample of 492 cruise passengers at a Mediterranean port of call. The findings revealed that port of call quality has…
Using a hazard-independent approach to understand road-network robustness to multiple disruption scenarios
2021
Abstract A range of predictable and unpredictable events can cause road perturbations, disrupting traffic flows and more generally the functioning of society. To manage this threat, stakeholders need to understand the potential impact of a multitude of predictable and unpredictable events. The present paper adopts a hazard-independent approach to assess the robustness (ability to maintain functionality despite disturbances) of the Sioux Falls network to all possible disruptions. This approach allows understanding the impact of a wide range of disruptive events, including random, localised, and targeted link failures. The paper also investigates the predictability of the link combinations wh…