منابع مشابه
travel time ∗
In this paper we use a model-based traffic control approach to determine dynamic speed limits with the aim of reducing fuel consumption and emissions, while still guaranteeing small travel times. The approach we propose is based on model predictive control (MPC). MPC is a modelbased control design method that combines prediction and on-line optimization of a performance criterion over a given t...
متن کاملOn the Impossibility of Time Travel
If a device could be built that would permit travel backward and forward in time in any sort of controlled fashion, the author of this essay would be among the first in line to purchase a ticket. The concept of time travel has long held an almost magical allure for laymen and scientists alike. And no wonder. How fascinating, indeed, to go back and visit the Earth during The Age of Dinosaurs, or...
متن کاملReal-time Estimation of Travel times on Arterial Roads – the Arrb Travel Time Model
Provision of travel time has been identified as a key road user support service which assists road authorities to improve network operation strategies and implement control measures. Travel times are commonly estimated for freeways where they are displayed to road users via variable message signs (VMS) but have proved far more difficult to calculate for arterial roads where traffic flow is inte...
متن کاملEfficient Time-Travel on Versioned Text Collections
The availability of versioned text collections such as the Internet Archive opens up opportunities for time-aware exploration of their contents. In this paper, we propose time-travel retrieval and ranking that extends traditional keyword queries with a temporal context in which the query should be evaluated. More precisely, the query is evaluated over all states of the collection that existed d...
متن کاملTime Travel and Time Machines
This paper is an enquiry into the logical, metaphysical, and physical possibility of time travel understood in the sense of the existence of closed worldlines that can be traced out by physical objects. We argue that none of the purported paradoxes rule out time travel either on grounds of logic or metaphysics. More relevantly, modern spacetime theories such as general relativity seem to permit...
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ژورنال
عنوان ژورنال: Nature
سال: 1992
ISSN: 0028-0836,1476-4687
DOI: 10.1038/357019a0