Search results for "work"
showing 10 items of 14511 documents
Port expansion and negative externalities: a willingness to accept approach
2015
Port expansion has been seen as the origin of negative externalities, affecting local residents’ well-being and contributing to the poor public image of ports. In this study, the contingent valuation method is used to estimate the costs borne by local residents as a consequence of the negative externalities derived from the growth of the Port of Valencia (Spain) in the last 30 years. As transport project appraisal has become more complex, this technique complements existing methodologies in this field, such as the social cost benefit analysis and the multicriteria analysis. Given the perceived property rights of families that have been living close to the port for a long time, a willingness…
1768 Safety culture and risk management in agriculture (sacurima)
2018
Introduction Agriculture is one of the most hazardous industries in Europe, measured by work-related injuries, diseases, disabilities and deaths. Statistics and studies show great differences in national injury and occupational disease rates, as well as approaches and support for prevention of these adverse outcomes. This EU-COST action explores reasons why agriculture lags behind other sectors, and why some countries have been more successful than others in reducing agricultural injuries and diseases. Methods Evaluation of health and safety programmes and approaches on the national level identification of knowledge, attitudes, behaviors and priorities among farmers regarding safety, health…
How is the Driver's Workload Influenced by the Road Environment?
2017
Abstract This paper focuses on the study of the driver's workload while driving on a rural two-lane road with different traffic flows. The aim of the research is to examine a parameter that could be representative of the driving effort, quite sensible to the external factors that cause disturbance to the regular driving activity. To solve this problem, the authors used a specific instrumented vehicle for monitoring some physiological parameters of the driver (as the eye movements and the Galvanic Skin Resistance), referring their values to the road context. The results are very interesting and confirm that knowing the workload is useful to improve the road safety only if it is related to th…
The last-mile vehicle routing problem with delivery options
2021
AbstractThe ongoing rise in e-commerce comes along with an increasing number of first-time delivery failures due to the absence of the customer at the delivery location. Failed deliveries result in rework which in turn has a large impact on the carriers’ delivery cost. In the classical vehicle routing problem (VRP) with time windows, each customer request has only one location and one time window describing where and when shipments need to be delivered. In contrast, we introduce and analyze the vehicle routing problem with delivery options (VRPDO), in which some requests can be shipped to alternative locations with possibly different time windows. Furthermore, customers may prefer some deli…
Methodology and trends for an intelligent transport system in developing countries
2018
Abstract Increasingly, the technologies that are used in telecommunications contribute to improve intelligent transport systems. These technologies are systems that offer several concepts like vehicular ad hoc networks, which allow reduction of traffic accidents, traffic congestion and consequently increase road safety and the comfort of road users. Developing countries in general and those of sub-Sahara in particular do not have telecommunication infrastructures, even road infrastructures for the implementation of an intelligent transport system. Moreover, with the serious increase in vehicles in these countries, the problem of traffic regulation arise especially in the inter-urban context…
Assessment of the Total Factor Productivity Change in the Spanish Ports: Hicks–Moorsteen Productivity Index Approach
2016
AbstractThe assessment of the productivity growth of ports is essential to improve their performance and competitiveness. Although there are several nonparametric methodologies to compute the productivity change, the Hicks–Moorsteen productivity index is the only multiplicatively completed index that can be computed without price data. For the first time, the total factor productivity (TFP) change of a sample of ports is evaluated. The analysis covers the 28 ports comprising the Spanish port system, using data over the period 2005–2012. The drivers of TFP—technical change, technical efficiency, mix efficiency, and residual scale efficiency—are also investigated. The results indicate that fr…
Measuring foreland container port connectivity disaggregated by destination markets: An index for Short Sea Shipping services in Spanish ports
2020
Abstract The present research aims to develop a Foreland Port Connectivity Index (FPCI) including both qualitative and quantitative variables related to the characteristics of the maritime services provided. To that end, the FPCI incorporates two discount factors—the number of shipping services and destination countries—as penalties to correct for the quality of a port connection. After defining the FPCI, the index is applied to Spanish ports to study their connectivity in terms of container Short Sea Shipping (SSS) services. Although the connectivity of SSS traffic has not been widely studied, it is an interesting case study as small ports play a more relevant role in facilitating access t…
Branch-and-Cut for the Split Delivery Vehicle Routing Problem with Time Windows
2019
The split delivery vehicle routing problem with time windows (SDVRPTW) is a notoriously hard combinatorial optimization problem. First, it is hard to find a useful compact mixed-integer programming (MIP) formulation for the SDVRPTW. Standard modeling approaches either suffer from inherent symmetries (mixed-integer programs with a vehicle index) or cannot exactly capture all aspects of feasibility. Because of the possibility to visit customers more than once, the standard mechanisms to propagate load and time along the routes fail. Second, the lack of useful formulations has rendered any direct MIP-based approach impossible. Up to now, the most effective exact algorithms for the SDVRPTW hav…
Heuristics for the capacitated modular hub location problem
2017
Abstract In this paper we study the hub location problem, where the goal is to identify an optimal subset of facilities (hubs) to minimize the transportation cost while satisfying certain capacity constraints. In particular, we target the single assignment version, in which each node in the transportation network is assigned to only one hub to route its traffic. We consider here a realistic variant introduced previously, in which the capacity of edges between hubs is increased in a modular way. This reflects the practical situation in air traffic where the number of flights between two locations implies a capacity in terms of number of passengers. Then, the capacity can be increased in a mo…
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…