1,042 research outputs found
An innovative operation‐time‐space network for solving different logistic problems with capacity and time constraints
No full textThis work describes an innovative operation-time-space network that can be easily adapted to model different logistic problems involving time and space decisions. In the recent literature, different time-space networks have been proposed to deal with specific requirements of problems arising in the logistic and transportation fields. The proposed network is able to deal with different types of capacity and time constraints that characterized the most part of logistic problems. The article explains how to construct the operation-time-space network, how to model time and capacity constraints of different types; moreover, it presents an application of this network to solve a logistic problem arising in the rail-sea exchange node, that is the scheduling of port rail shunting operations. Other applications are briefly introduced. Finally, the well-known quay crane scheduling problem is modeled, thanks to the operation-time-space network; the related flow model is tested by using a benchmark suite available in the literature
Port Rail Shunting Optimization Problems
No full textThe work focuses on a particular section of the intermodal chain of freight transportation, which is the link between rail and sea transportation modes and happens in the maritime port area. Among this field, the study deals with the management of rail operations, called here rail shunting operations, that have to be performed in the port area.
Two optimization problems arises in this context. The first concerns the scheduling of the rail shunting operations, here called Port Rail Shunting Scheduling Problem (PRSSP). The second deals with the re-scheduling of the same operations in case of unpredictable events, here called Port Rail Shunting Re-Scheduling Problem (PRSRP). After a literature overview on the concerning studies, we concentrate on an innovative way to use the well known space-time networks as solution approach structure for both the above mentioned problems. The innovative structure has been called operation-time-space network and is deeply analyzed in a dedicated chapter.
A network flow model based on an operation-time-space network for solving PRSSP has been developed. It has been tested using random generated instances providing good results. The same model has been extended in order to solve PRSRP and it has been tested giving good results as well.
Finally, the models have been used to solve the real case of a port area located in Italy in order to test the applicability of the developed models to a real context. The tests have been executed using real data and provided good results confirming the possibility to apply the proposed approach in similar real problems
Optimization challenges and literature overview in the intermodal rail-sea terminal
No full textThis work focuses on a particular node of the intermodal chain of transportation, i.e. the maritime port area that represents the link between rail and sea transportation modes. Since this exchange node of the chain has not been addressed much yet, the aim of the present study is to provide a description of the process of rail operations in port area, to give an overview of the optimization challenges and to review the existing literature on it. The purpose of the paper is to attract the researchers attention on this particular intermodal node, where there is room for improvements
An optimization model to design a new cruise itinerary: the case of Costa Crociere
No full textThis work analyses the complex processes for the development of cruises' itineraries to offer on the market and proposes a mathematical model for determining a new itinerary maximizing revenues, customers satisfaction, while minimizing operative costs. This work represents one of the first attempt to apply optimization techniques to cruise shipping and has been realized in collaboration with Costa Crociere, a cruise company operating in Europe
A comparison of optimization models to evaluate the impact of fuel costs when designing new cruise itineraries
No full textThe itinerary design is a problem that belongs to the class of cruise supply. The development of cruises’ itineraries to offer on the market is a long process. Given a ship located in a specific world’s basin, given a duration and a homeport, an itinerary has to be planned choosing a sequence of ports to visit among a set of available ones. The itinerary must be characterized by a schedule, which comprehends the arrival time and the departure time of the ship for each port. The objectives to pursue in the decisions are the maximization of both the customer satisfaction and the revenue and the minimization of the costs. In this paper the focus is on costs, that depend on fuel consumption and ports’ services. The fuel cost is function of the speed of the ship. Starting from a model recently proposed in the literature for solving the cruise itinerary designing problem (CIDP) (Ambrosino et al. in Proceedings of 15th IFAC Symposium on Control in Transportation Systems, Savona, Italy, June 2018, [3]) in which fuel costs were based on classes of speed, a different model has been developed for including a more precise fuel cost computation. The fuel costs represent a great part of the company costs, influencing the operative margin. Thus, the fuel consumption is here computed in terms of metric tons for each single speed. The model has been tested solving real cases of Costa Crociere in the Mediterraneo basin. The obtained solutions have been compared, both in terms of cruise route and objectives values with those obtained by the previous model used by the company to define optimal itineraries
Veronica mas, Spirea, Barbarea
No full text1. Nome scientifico: Veronica chamaedrys L.
(Scrophulariaceae)
Nome attuale: Veronica comune
2. Nome scientifico: Spiraea hypericifolia L.
(Rosaceae)
Nome attuale: Spirea spagnola
3. Nome scientifico: Barbarea vulgaris r. Br.
(Brassicaceae, Cruciferae)
Nome attuale: Erba di Santa Barbar
Veronica alpina (Alpine Brooklime) : Alpine Brooklime
No full textClass: Dicotyledoneae
Family: Scrophulariaceae
Genus: Veronica
Species: alpin
Veronica peregrina (Hairy Speedwell) : Hairy Speedwell
No full textClass: Dicotyledoneae
Family: Scrophulariaceae
Genus: Veronica
Species: peregrin
Ep. #024 - Veronica Strang
No full textThis recording and transcript form part of a collection of podcasts conducted by the Cultures of Energy at Rice University. Cultures of Energy brings writers, artists and scholars together to talk, think and feel their way into the Anthropocene. We cover serious issues like climate change, species extinction and energy transition. But we also try to confront seemingly huge and insurmountable problems with insight, creativity and laughter.Water, water everywhere. The human sciences have become animated by the politics, ethics and materiality of water of late and for good reason. Our guest (11:13) on this week’s Cultures of Energy podcast was one of the first to get this conversation started. Anthropologist Veronica Strang, currently Executive Director of the Institute for Advanced Study at Durham University, is the author of The Meaning of Water (Oxford, 2004) and Water: Culture and Nature (Reaktion, 2015) and a recipient of UNESCO’s International Water Prize. We talk about how the transgressive and transformative properties of water cut across cultures and how its material liquidity complicates our cultural and legal understandings of ownership and property. Veronica explains why we have to think water across scales, from its mediation of individual bodies to how its flows form communities. We talk about the infamous case of Bolivia’s water privatization, efforts to enclose water resources across the world and how contemporary politics of water are undermining democracy. Veronica also reminds us though that efforts to centralize control over water are ancient and that the movements that are now seeking to decentralize water resources also have hope. In closing we discuss cosmological and mythological water beings ranging from rainbow serpents to Chinese water dragons to the Lambton Worm, reputed to live in Durham’s own River Wear. Is our concern with hydration and floods these days informed by the moral economy and sacred vitality of water? Has urbanization caused us to lose touch with the hydrological cycle that so powerfully informed the cultural imaginations of our ancestors? Pour yourself a glass of water and listen on
Lilium convallium flore pleno, Veronica minima, Liliu conualliu, Consolida media
No full text1. Nome scientifico: Convallaria majalis L. cv.
(Liliaceae)
Nome attuale: Mughetto
2. Nome scientifico: Veronica prostrata L.
(Scrophulariaceae)
Nome attuale: Veronica sdraiata
3. Nome scientifico: Convallaria majalis L.
(Liliaceae)
Nome attuale: Mughetto, Giglio delle convalli
4. Nome scientifico: Ajuga reptans L.
(Lamiacee, Labiatae)
Nome attuale: Bugula, Erba di San Lorenzo, Consolid
- …
