Concurrent and Distributed Shortest-Path Searches in Multiagent-Based Transport Systems

Author(s):  
Max Gath ◽  
Otthein Herzog ◽  
Maximilian Vaske
2019 ◽  
Vol 52 (4) ◽  
pp. 27-46 ◽  
Author(s):  
Kalliopi Kyriakou ◽  
Konstantinos Lakakis ◽  
Paraskevas Savvaidis ◽  
Socrates Basbas

Urban traffic congestion created by unsustainable transport systems and considered as a crucial problem for the urbanised areas provoking air pollution, heavy economic losses due to the time and fuel wasted and social inequity. The mitigation of this problem can improve efficiency, connectivity, accessibility, safety and quality of life, which are crucial parameters of sustainable urban mobility. Encouraging sustainable urban mobility through smart solutions is essential to make the cities more liveable, sustainable and smarter. In this context, this research aims to use spatiotemporal data that taxi vehicles adequately provide, to develop an intelligent system able to predict traffic conditions and provide navigation based on these predictions. GPS (Global Positioning System) data from taxi are analysed for the case of Thessaloniki city. Trough data mining and map-matching process, the most appropriate data are selected for travel time calculations and predictions. Several algorithms are investigated to find the optimum for traffic states prediction for the specific case study concluding that ANN (Artificial Neural Networks) outperforms. Then, a new road network map is created by producing spatiotemporal models for every road segment under investigation through a linear regression implementation. Moreover, the possibility to predict vehicle emissions from travel times is investigated. Finally, an application with a graphical user interface is developed, that navigates the users with the criteria of the shortest path in terms of trip length, travel time shortest path and “eco” path. The outcome of this research is an essential tool for drivers to avoid congestion spots saving time and fuel, for stakeholders to reveal the problematic of the road network that needs amendments and for emergency vehicles to arrive at the emergency spot faster. Besides that, according to an indicator-based qualitative assessment of the proposed navigation system, it is concluded that it contributes significantly to environmental protection and economy enhancing sustainable urban mobility.


Nowadays, automated guided vehicles (AGV) play very important role in modern factory automations. The AGV systems provide efficient routing for material flow and distribution among workstations at the exact time and place. Routing of AGV is the process of determining routes to fulfill their respective transport jobs. The routing problem of AGV in production system can be studied as a shortest path problem on a transfer network. It aims to find the shortest path between two vertices or nods. Most transport systems using AGV are centrally controlled and use static routing (pre-defined routes), which follows fixed line. Instead of using fixed path, dynamic routing for AGV can be used to add a high flexibility to the system. To accommodate the increased flexibility and reduced time, new operational controllers using Labview software must be able to adapt to small deviations. In this paper, routing of AGV, different AGV shortest path algorithms such as Dijkstra algorithm, A-star algorithm, Short Path Problem with Time Window (SPPTW), hybrid partial swarm optimization and genetic algorithm PSOGA are discussed with highlights of their main differences and comparison between them. AGV Scheduling is presented. In addition, the controller developed within Labview environment directs an AGV in real time using local position system are achieved.


Author(s):  
Andrew Thacker

This innovative book examines the development of modernism in four European cities: London, Paris, Berlin, and Vienna. Focusing upon how literary and cultural outsiders represented various spaces in these cities, it draws upon contemporary theories of affect, mood, and literary geography to offer an original account of the geographical emotions of modernism. It considers three broad features of urban modernism: the built environment of the particular cities, such as cafés or transport systems; the cultural institutions of publishing that underpinned the development of modernism in these locations; and the complex perceptions of writers and artists who were outsiders to the four cities. Particular attention is thus given to the transnational qualities of modernism by examining figures whose view of the cities considered is that of migrants, exiles, or strangers. The writers and artists discussed include Mulk Raj Anand, Gwendolyn Bennett, Bryher, Blaise Cendrars, Joseph Conrad, T. S. Eliot, Christopher Isherwood, Hope Mirlees, Noami Mitchison, Jean Rhys, Sam Selon, and Stephen Spender.


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