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- Fu, Jiali, et al.
(författare)
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Optimizing fleet selection for earthmoving operations
- 2013
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Ingår i: ISEC 2013 - 7th International Structural Engineering and Construction Conference. - : Research Publishing Services. - 9810753551 - 9789810753559 ; , s. 1261-1266
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Konferensbidrag (refereegranskat)abstract
- Earthmoving operations often involve a large number of specially designed equipment with significant purchasing/leasing prices, high operating and maintenance costs. Hence, choosing the right fleet is a major concern from the construction planners' point of view. This paper presents a methodology that combines discrete-event simulation and optimization to solve the optimal fleet selection problem for earthmoving operations. Two optimization objectives are formulated and solved using the proposed framework and a genetic algorithm: minimization of Total Cost of Ownership (TCO) and maximization of productivity. Further, a two-stage rating scheme is introduced to arrange the fleet configurations so that the optimization algorithm converges to a fleet with better second-stage performance while the first-stage performance remains at the same level. The case study shows that the proposed mechanism can effectively allocate a local optimal equipment combination for earthmoving operations and hence serve as an efficient tool for construction management.
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- Mattsson, Lars-Göran, 1947-, et al.
(författare)
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Network-based infrastructure vulnerability analysis : A critical review of recent Swedish studies
- 2013
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Konferensbidrag (refereegranskat)abstract
- Recent disasters such as the 2004 Thailand tsunami, the 2010 Haiti earthquake, the 2011 Fukushima Daiichi nuclear power accident and the 2012 Sandy hurricane sadly illustrate the vulnerability of modern societies. The far-reaching consequences of these disasters have often been possible to attribute partly to the increasing complexity of the socio-technical systems that modern life relies on. Everyday life, business, production and many critical societal functions are highly dependent on systems for information and telecommunication, power supply, transport, water provision, sewage handling, as well as financial transactions, just to mention a few critical societal infrastructure systems. Moreover, these different infrastructure systems tend to be increasingly dependent on each other. This means that the consequences of a collapse in one infrastructure system can spread widely and be difficult to predict. The ongoing climate change is likely to make extreme weather even more common, which will intensify the consequences and uncertainties of such events for the society. Sweden is a country with a very low risk of earthquakes and where adverse weather conditions tend to be less dramatic than in most other countries. Still, hurricanes, heavy snow storms and flooding due to continuous raining are not uncommon. Preventing emergencies and disasters, reducing their consequences and improving the resilience of the infrastructure systems are important national, regional and local political goals. In this presentation we will review some recent research in Sweden on the vulnerability of network-based infrastructure systems, concentrating on power distribution and transport systems. We will present and compare various methodological approaches that have been applied. To what extent is it possible to use an approach developed for one system for analyzing another system? We will critically discuss how useful these approaches are, or could be, for planning, maintenance and operation of the infrastructure systems in order to increase their robustness and resilience. We will also identify important knowledge gaps and alternative approaches where further research could be particularly fruitful.
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- Rahmani, Mahmood, 1977-, et al.
(författare)
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Floating car and camera data fusion for non-parametric route travel time estimation
- 2014
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Ingår i: Procedia Computer Science. - : Elsevier B.V.. - 1877-0509. ; , s. 390-395
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Konferensbidrag (refereegranskat)abstract
- Traffic management centers take advantage of various data collection systems ranging from stationary sensors e.g. automated vehicle identification systems to mobile sensors e.g. fleet management systems. Each type of data collection system has its own advantages and disadvantages. Stationary sensors has less measurement noise than mobile sensors but their network coverage is limited. On the other hand, mobile sensors cover expand areas of road networks but they have less penetration rate and frequency of reports. Traffic state estimation can benefit from fusion of data from various sources as they complement each other. This paper introduces a route travel time estimation method that aggregates data from two traffic data sources, automated number plate recognition system and floating car data.
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