Search results for "Travel"
showing 10 items of 402 documents
The General Routing Problem polyhedron: Facets from the RPP and GTSP polyhedra
1998
[EN] In this paper we study the polyhedron associated with the General Routing Problem (GRP). This problem, first introduced by Orloff in 1974, is a generalization of both the Rural Postman Problem (RPP) and the Graphical Traveling Salesman Problem (GTSP) and, thus, is NP -hard. We describe a formulation of the problem such that from every non-trivial facet-inducing inequality for the RPP and GTSP polyhedra, we obtain facet-inducing inequalities for the GRP polyhedron, We describe a new family of facet-inducing inequalities for the GRP, the honeycomb constraints, which seem to be very useful for solving GRP and RPP instances. Finally, new classes of facets obtained by composition of facet-i…
Fascioliasis: A worldwide parasitic disease of importance in travel medicine
2014
Fascioliasis is a foodborne zoonotic disease caused by the two parasite species Fasciola hepatica and Fasciola gigantica. This trematodiasis has never been claimed special relevance for travellers and migrants. However, the situation has drastically changed in the last two decades, in a way that fascioliasis should today be included in the list of diseases to be enhanced in Travel Medicine. Different kind of travellers have been involved in human infection reports: business travellers, tourists, migrants, expatriated workers, military personnel, religious missionaries, and refugees. Europe is the continent where more imported cases have been reported in many countries. More cases would have…
Public transportation and fear of crime at BRT Systems: Approaching to the case of Barranquilla (Colombia) through integrated choice and latent varia…
2021
Abstract Security perception and Fear of Crime (FoC) in urban scenarios have the potential to affect travel behavior, changing people’s travel choices and patterns. In this sense, the feeling of being “safe” or “at-risk” in public transportation not only depends on observable factors like illumination, travel companionship or transport crowding, but also on unobservable individual-specific latent attributes, among which fear of crime constitutes a major issue to consider in transport security policy-making. This study aimed to describe the relationships among sociodemographic features, travel situations, system-design features, and the Fear of Crime at three different locations (buses, bus …
Dwie drogi ze Wschodu na Zachód. Szkic biograficzny do historii polskich losów XIX i XX wieku
2020
The article was inspired by the biography of Zofia Kossak-Szczucka. The rich life of Zofia Kossak was full of extraordinary situations and twists and turns, but above all, her life was characterized by a constant journey. The road from one end of Europe – Ukraine, to the other – the British Isles. Her story became a pretext for presenting the path that two other Poles traveled from the eastern ends of Europe towards its heart and western borders. The first of them was known, although widely, but only from one chapter of the biography – Gabriel Narutowicz. An extremely interesting figure, who came to Switzerland from Lithuania for health reasons in the mid-1880s. He has found his new home in…
Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy)
2017
On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We conse…
Visioni dell’America. Viaggio, spazialità e narrazione in De Amicis e Amado
2021
Nella prospettiva della geografia culturale l’odeporica offre l’opportunità di studiare alcune dinamiche di (ri)produzione simbolica relative al modo di concepire e rappresentare concetti chiave quali lo spazio, il paesaggio e le interazioni umane. Questo lavoro, partendo dall’analisi di alcuni brani significativi di due raccolte di scritti, In America (1897) di Edmondo De Amicis e In giro per le Americhe (2001) di Jorge Amado, studia, con un approccio geografico-culturale e semiotico, le modalità di costruzione e descrizione dello spazio fisico e simbolico comprese le «frontiere», nonché le interazioni e la socialità attraverso la testualizzazione di esperienze diverse. La comparazione fra…
Social isolation and physical activity mediate associations between free bus travel and wellbeing among older adults in England
2019
Background: Aims of this study were: (i) to examine relationships between free bus travel and wellbeing, and (ii) to assess the extent to which these associations can be explained by two key potential mediators: social isolation and physical activity. Methods: Data were from the English Longitudinal Study of Ageing (n = 5861). Linear regression models tested associations between (i) concessionary bus pass (CBP) ownership and (ii) frequency of CBP use and three measures of wellbeing (quality of life, life satisfaction, depressive symptoms), adjusting for age, sex, marital status, socioeconomic status and limiting long-standing illness. Mediation analyses tested the role of (i) social isolati…
Active Travel and Mild Cognitive Impairment among Older Adults from Low- and Middle-Income Countries
2021
Active travel may be an easily achievable form of physical activity for older people especially in low- and middle-income countries (LMICs), but there are currently no studies on how this form of physical activity is associated with a preclinical state of dementia known as mild cognitive impairment (MCI). Therefore, we aimed to investigate the association between active travel and MCI among adults aged ≥50 years from six LMICs. Cross-sectional, community-based data from the World Health Organization’s Study on Global Ageing and Adult Health were analyzed. The definition of MCI was based on the National Institute on Ageing-Alzheimer’s Association criteria. Active travel (minutes/week) was as…
La GTT, metodologia non invasiva per caratterizzare lo strato esterno degradato dei manufatti lapidei
2008
In questo lavoro viene descritta una metodologia non invasiva ne, tanto meno, distruttiva per studiare il degrado degli strati superficiali dei manufatti lapidei, correlandolo ai parametri di resistenza meccanica. La metodologia adopera come strumento diagnostico la propagazione delle onde elastiche nel mezzo in esame. In particolare, considerando che l'ordine di grandezza degli spessori ricercati è compreso tra le frazioni di millimetro e pochi centimetri, le frequenze delle onde elastiche utilizzabili sono quelle ultrasoniche, dalle decine di kHz ai MHz (e quindi, con velocità di propagazione dell'ordine di 4000 m/s, con lunghezze d'onda dai centimetri alle frazioni di millimetro). Questa…
Novel Wireless Sensor System for Dynamic Characterization of Borehole Heat Exchangers
2011
The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two specials valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the…