Accurate Location of Seismic Sources With and Without Travel Time Model

2008 ◽  
pp. 197-216
Author(s):  
V. Pinsky
Keyword(s):  
Travel Time ◽  
Seismic Sources ◽  
Time Model

Choice of a teleseismicP-wave travel-time model and the associated source corrections

1972 ◽  
Vol 101 (1) ◽  
pp. 74-89
Author(s):  
S. K. Arora ◽  
C. A. Krishnan
Keyword(s):  
Travel Time ◽  
Time Model ◽  
Wave Travel

scholarly journals Travel Time Model of Left-Turning Vehicles at Signalized Intersection

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Leng Jun-qiang ◽  
Feng Yu-qin ◽  
Zhai Jing ◽  
Bao Lei ◽  
He Yi
Keyword(s):  
Travel Time ◽  
Flow Rate ◽  
Signalized Intersection ◽  
Time Model ◽  
Through Flow ◽  
Negative Exponential Distribution ◽  
The Common ◽  
Queue Theory ◽  
Negative Exponential ◽  
The Impact

The travel time of left-turning vehicles at signalized intersection was discussed. Under the assumption that the opposing through vehicles headway follows M3 distribution, the travel time model was established on the basis of gap theory and queue theory. Comparison was done with the common model based on the assumption that the opposing through vehicles headway follows negative exponential distribution. The results show that the model in this paper has stronger applicability and its most relative error is less than 15%. In addition, the sensitivity analysis was done. The results show that the opposing through flow rate has significant impact on travel time. The impact of left-turning flow rate and following headway is light when the opposing through flow rate is small, the threshold is about 0.18 veh/s. The model established in this paper can well calculate travel time of left-turning vehicles at intersection, and the methodology may provide reference to other occasions.

Alternative Conditions for a Well-Behaved Travel Time Model

2005 ◽  
Vol 39 (3) ◽  
pp. 417-428 ◽  
Author(s):  
Malachy Carey ◽  
Y. E. Ge
Keyword(s):  
Travel Time ◽  
Time Model

scholarly journals Travel Time Model for Right-Turning Vehicles of Secondary Street at Unsignalized Intersections

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Feng Yu-Qin ◽  
Leng Jun-Qiang ◽  
Wang Peng ◽  
He Yi ◽  
Zhang Gui-e
Keyword(s):  
Travel Time ◽  
Poisson Distribution ◽  
Flow Rate ◽  
Erlang Distribution ◽  
Time Model ◽  
Unsignalized Intersections ◽  
Theory Comparison ◽  
The Common ◽  
Queue Theory ◽  
The Right

The travel time of right-turning vehicles on secondary street at unsignalized intersection is discussed in this paper. Under the assumption that the major-street through vehicles’ headway follows Erlang distribution and secondary-street right-turning vehicles’ headway follows Poisson distribution. The right-turning vehicles travel time model is established on the basis of gap theory and M/G/1 queue theory. Comparison is done with the common model based on the assumption that the major-street vehicles’ headway follows Poisson distribution. An intersection is selected to verify each model. The results show that the model established in this paper has stronger applicability, and its most relative error is less than 15%. In addition, the sensitivity analysis has been done. The results show that right-turning flow rate and major-street flow rate have a significant impact on the travel time. Hence, the methodology for travel time of right-turning vehicles at unsignalized intersection proposed in this paper is effective and applicable.

Travel time model for the warehousing system with a tower crane S/R machine

2002 ◽  
Vol 43 (3) ◽  
pp. 495-507 ◽  
Author(s):  
S.G Koh ◽  
B.S Kim ◽  
B.N Kim
Keyword(s):  
Travel Time ◽  
Time Model ◽  
Tower Crane

scholarly journals Model for Estimating Travel Time on Dynamic Highway Networks in Akure, Ondo State Nigeria

2020 ◽  
Vol 5 (3) ◽  
pp. 275-281
Author(s):  
Onyemaechi John Nnamani ◽  
Victor Ayodele Ijaware ◽  
Joseph Olalekan Olusina ◽  
Timothy Oluwadare Idowu
Keyword(s):  
Regression Model ◽  
Travel Time ◽  
Traffic Volume ◽  
Real Field ◽  
Percentage Error ◽  
Time Variability ◽  
Time Model ◽  
Independent Variables ◽  
Highway Networks ◽  
Significant Difference

Travel time variability or distribution is very important to travel time reliability studies in transportation systems. This study aimed at developing a multivariate regression model for estimating travel times for dynamic highway networks in Akure Metropolis. The independent variables for the model are Traffic volume, density, speed of vehicles, and traffic flow while the dependent response variable is the Travel time. The estimated travel time was compared with the observed travel time from the real field data and the estimation using the regression model reveals a significant level of accuracy. Also, it was discovered that traffic volume, speed, density, and flow were highly correlated with travel time. The result analyzed using descriptive statistics in the SPSS software environment reveals an R2 value of 0.998, thereby indicating that the independent variables accounted for 99% of travel time in the study area. The Hypothesis tested at 95% confidence level using ANOVA unveils that there is no significant difference between the observed and estimated travel time model. The Mean Absolute Percentage Error (MAPE) of 0.049 shows that the model performed very well and was very efficient for analyzing the probabilistic relation between travel time and the independent variables. The study recommends the use of the developed travel time model for estimating travel time within the study area.

scholarly journals The Theory of Multi-Earthquake Location by Least Squares and Applications to Groups of North Island, New Zealand Mantle Earthquakes

2021 ◽  
Author(s):  
◽  
Euan George Campbell Smith
Keyword(s):  
New Zealand ◽  
Least Squares ◽  
Travel Time ◽  
Least Squares Method ◽  
Confidence Regions ◽  
Model Errors ◽  
Time Model ◽  
Crustal Model ◽  
Standard Linear ◽  
Mantle Earthquakes

<p>Aspects of the standard least squares method of locating earthquakes and its extensions are discussed. It is shown that there is a need to carefully separate and distinguish between the statistical and deterministic properties of the least squares solution and the algorithm used to obtain it. Standard linear statistical analysis gives reasonable confidence regions for the hypocentre provided that the errors in the model travel time to pairs of stations are not correlated. The travel time residuals which result from the overdetermined system are unreliable estimates of the model errors, as are the pooled residuals from groups of events whether or not the data are homogeneous. The concepts of Absolute and Relative hypocentre determination are clarified and the Homogeneous Station method is developed and demonstrated to be a good relative location method. The application of the method to a group of North Island, New Zealand subcrustal earthquakes chosen for homogeneity revealed that the earthquakes occurred in a thin, fairly that dipping zone that could be as thin as 9 km and is not thicker than 18 km. The result is a significant refinement of previous estimates for New Zealand. The method of Joint Hypocentre Determination first described by Douglas (1967) is examined. The advantage of the method is that the error in the travel time model is estimated as well as allowing for and estimating the effect of an interaction of this error with the hypocentre parameters of the earthquakes. The application of this method to groups of, North Island, New Zealand earthquakes allows very significant improvements to the travel time model to be made and confirms the result that there is a velocity contrast for both P and S of between six and ten percent between paths in and entirely out of the downgoing Pacific plate. Estimates of the velocities in the plate are 8.6 [plus or minus] .1 km/sec. for P and 4.74 [plus or minus] km/sec. for S. In addition, station terms are calculated which describe the average departure from the new model of travel times to the stations contributing data to the study. These terms may be interpreted as arising from crustal structure local to the station which is different from that of the average crustal model used. The conclusion is reached that apart from providing better absolute hypocentre estimates, the method of Joint Hypocentre Determination can be made to yield worthwhile information about structure on the scale considered here.</p>

scholarly journals Travel Time Model of the Storage/Retrieval Machine for Multi-Deep AS/RS Based on Flexsim

2015 ◽  
Vol 9 (1) ◽  
pp. 1833-1839 ◽  
Author(s):  
Wang Fan ◽  
Guo Dongfen ◽  
Tang Shujuan ◽  
He Hong ◽  
Cui Xiao
Keyword(s):  
Travel Time ◽  
Time Model
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