Real-Time Distribution Algorithm for Fully Comparison Data Based on Storm

2021 ◽  
Author(s):  
Chang-qing Dong ◽  
Chen Chen ◽  
Nver Ren ◽  
Jian-jun Cai
Keyword(s):  
Real Time ◽  
Time Distribution ◽  
Comparison Data

Minimum Sampling Size of Floating Cars for Urban Link Travel Time Distribution Estimation

2019 ◽  
Vol 2673 (3) ◽  
pp. 24-43 ◽  
Author(s):  
Meiping Yun ◽  
Wenwen Qin
Keyword(s):  
Sample Size ◽  
Travel Time ◽  
Real Time ◽  
Time Distribution ◽  
Ground Truth ◽  
Sample Size Determination ◽  
Minimum Sample Size ◽  
Travel Time Distribution ◽  
Minimum Sample ◽  
Link Travel Time

Despite the wide application of floating car data (FCD) in urban link travel time estimation, limited efforts have been made to determine the minimum sample size of floating cars appropriate to the requirements for travel time distribution (TTD) estimation. This study develops a framework for seeking the required minimum number of travel time observations generated from FCD for urban link TTD estimation. The basic idea is to test how, with a decreasing the number of observations, the similarities between the distribution of estimated travel time from observations and those from the ground-truth vary. These are measured by employing the Hellinger Distance (HD) and Kolmogorov-Smirnov (KS) tests. Finally, the minimum sample size is determined by the HD value, ensuring that corresponding distribution passes the KS test. The proposed method is validated with the sources of FCD and Radio Frequency Identification Data (RFID) collected from an urban arterial in Nanjing, China. The results indicate that: (1) the average travel times derived from FCD give good estimation accuracy for real-time application; (2) the minimum required sample size range changes with the extent of time-varying fluctuations in traffic flows; (3) the minimum sample size determination is sensitive to whether observations are aggregated near each peak in the multistate distribution; (4) sparse and incomplete observations from FCD in most time periods cannot be used to achieve the minimum sample size. Moreover, this would produce a significant deviation from the ground-truth distributions. Finally, FCD is strongly recommended for better TTD estimation incorporating both historical trends and real-time observations.

Magnetic resonance imaging methods to reveal the real-time distribution of nickel in porous media

2008 ◽  
Vol 59 (3) ◽  
pp. 476-485 ◽  
Author(s):  
A. B. Moradi ◽  
S. E. Oswald ◽  
J. A. Massner ◽  
K. P. Pruessmann ◽  
B. H. Robinson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Porous Media ◽  
Magnetic Resonance ◽  
Real Time ◽  
Time Distribution ◽  
Resonance Imaging ◽  
Imaging Methods ◽  
The Real
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