Parameter Calibration of Traffic Flow Speed-Density Model Based on K-means Clustering Algorithm and Least Square Method

2021 ◽  
Author(s):  
Gang Ren ◽  
Sai Zhu
Keyword(s):  
Traffic Flow ◽  
Clustering Algorithm ◽  
Least Square Method ◽  
Flow Speed ◽  
Least Square ◽  
Density Model ◽  
Parameter Calibration ◽  
Model Based

Model-based control of the substrate concentration in an aeration basin using the wastewater level

1998 ◽  
Vol 37 (12) ◽  
pp. 335-342 ◽  
Author(s):  
Jacek Czeczot
Keyword(s):  
Substrate Concentration ◽  
Consumption Rate ◽  
Least Square Method ◽  
Estimation Procedure ◽  
Adaptive Controller ◽  
Open Loop ◽  
Least Square ◽  
Substrate Consumption ◽  
Model Based ◽  
Effluent Flow Rate

This paper deals with the minimal-cost control of the modified activated sludge process with varying level of wastewater in the aerator tank. The model-based adaptive controller of the effluent substrate concentration, basing on the substrate consumption rate and manipulating the effluent flow rate outcoming from the aerator tank, is proposed and its performance is compared with conventional PI controller and open loop behavior. Since the substrate consumption rate is not measurable on-line, the estimation procedure on the basis of the least-square method is suggested. Finally, it is proved that cooperation of the DO concentration controller with the adaptive controller of the effluent substrate concentration allows the process to be operated at minimum costs (low consumption of aeration energy).

Error Model and Calibration Analysis of the Flexible Coordinate Measuring Machine

2011 ◽  
Vol 121-126 ◽  
pp. 3273-3277 ◽  
Author(s):  
Fang Li ◽  
Shu Gui Liu ◽  
Lei Zhao
Keyword(s):  
Mathematical Model ◽  
Coordinate Measuring Machine ◽  
Least Square Method ◽  
Coefficient Matrix ◽  
Error Model ◽  
Least Square ◽  
Parameter Calibration ◽  
Measuring Machine ◽  
Improving Accuracy ◽  
The Mathematical Model

A new 5-DOF flexible coordinate measuring machine (CMM) is introduced in this paper, which uses REVO system produced by Renishaw. According to the D-H method, the mathematical model is built, and then the error model of the flexible CMM is derived. The parameter calibration based on the nonlinear least square method is analyzed theoretically. Due to the disadvantages of Gauss-Newton method, LM method is researched, which improved the singularity of the coefficient matrix. The calibration analysis is a basis for improving accuracy of the flexible CMM.

GMDH Network Model Based on Simulated Annealing and Genetic Algorithm

2013 ◽  
Vol 380-384 ◽  
pp. 1370-1373
Author(s):  
Xiao Ling Zhang ◽  
Li Kun Zou
Keyword(s):  
Genetic Algorithm ◽  
Simulated Annealing ◽  
Network Model ◽  
Simulated Annealing Algorithm ◽  
Least Square Method ◽  
Least Square ◽  
Model Based ◽  
Simulated Annealing Genetic Algorithm ◽  
Global And Local ◽  
Combined Algorithm

According to the traditional UMDH network modeling with the least square method to recognize parameters ,it's easy to fall into local minimum ,and with the result that the prediction effect is not ideal. This paper puts forward to combine the simulated annealing algorithm and genetic algorithm, and introduces the combined algorithm to the UMDH network which is used to identify some of its description type coefficient. In this paper ,it describes the simulated annealing genetic algorithm ,and constructs the UMDH network model based on this algorithm, and the model is applied to the simulation of debris flow prediction research ,forecast average relative error reached 3. 54%. The results show that the algorithm not only ensuring the global optimization but also preventing premature convergence, improve the UMDH network model of global and local searching optimal ability further.

scholarly journals A TRAFFIC FUNDAMENTAL DIAGRAM CALIBRATING METHODOLOGY TO AVOID UNBALANCED SPEED–DENSITY OBSERVATIONS

Transport ◽  
2021 ◽  
Vol 36 (1) ◽  
pp. 13-24
Author(s):  
Chunbo Zhang ◽  
Zhaoguo Huang ◽  
Yonggang Wang
Keyword(s):  
Traffic Flow ◽  
Least Square Method ◽  
Least Square ◽  
Fundamental Diagram ◽  
Traffic Capacity ◽  
Density Relationship ◽  
Sample Method

Traffic fundamental diagram is extremely important to analyse traffic flow and traffic capacity, and the central part of traffic fundamental diagram is to calibrate speed–density relationship. However, because of unbalanced speed–density observations, calibrating results using Least Square Method (LSM) with all speed–density points always lead to inaccurate effect, so this paper proposed a selecting data sample method and then LSM was used to calibrate four well-known single-regime models. Comparisons were made among the results using LSM with all speed–density points and the selecting data sample. Results indicated that the selecting data sample method proposed by this paper can calibrate the singleregime models well, and the method overcomes the inaccurate effect caused by unbalanced speed–density observations. Data from different highways validated the results. The contribution of this paper is that the proposed method can help researchers to determine more precise traffic fundamental diagram.

Vessel Traffic Flow Distribution Model of Bridge Area Waterway in the Middle Stream of Yangtze River

2014 ◽  
Vol 551 ◽  
pp. 127-133 ◽  
Author(s):  
Hai Qiang Hou ◽  
Yi Cheng Li ◽  
Wei He ◽  
Xing Long Liu
Keyword(s):  
Traffic Flow ◽  
Yangtze River ◽  
Flow Distribution ◽  
Least Square Method ◽  
Least Square ◽  
Distribution Model ◽  
Distribution Rule ◽  
Operating Factor ◽  
Safety Operation ◽  
Vessel Speed

Traffic flow data collection in Wuhan Yangtze River Bridge, locates in the middle of Yangtze River, is help for analysis of the waterway operating factor, which in return increases the capacity in the bridge area waterways and promotes vessel collision avoidance. Traffic flow parameters like vessel speed, arrival time, vessel clearance were collected by manual observation. Through analysis of vessel speed and vessel clearance distribution rule, the vessel speed-clearance model is established based on least square method. Real-time density of ships on navigation, channel utilization and ship safety operation area can be obtained by study on the relationship between speed and shipping space..

Location and Measurement of Acupoints on Head-Model Based on Structured-Light Scanning

2011 ◽  
Vol 48-49 ◽  
pp. 660-663 ◽  
Author(s):  
Yan Wang ◽  
Jian Fei Ouyang
Keyword(s):  
Chinese Medicine ◽  
Structured Light ◽  
Least Square Method ◽  
Least Square ◽  
Digital Model ◽  
Head Model ◽  
Coordinate Systems ◽  
Model Based ◽  
Symmetric Plane ◽  
Structured Light Scanning

408 acupoints of human body, including 362 acupoints of the fourteen meridians and 46 extra points, are the exit and entrance of the Viscera Meridians energy. The acupoints location is fundamental to study Chinese Medicine. The paper presents a new precision modeling and measuring technology for acupoints location on head-model based on machine vision. The head-model is measured fast and accurately by the structured-light scanning. The digital model of head-model can be made from the cloudy data through the acquisition, align, merge, and edit. The head-model coordinate systems based on the geometric morphometry is developed for dynamic measurement of an unfixed live head in which any acupoints coordinate can be measured. The plane is established based on the symmetric head. The curve of the plane across nose is fitted by the least-square method. The origin is acquired from the curve first derivative, which is unique and accurate. The tangent through the origin is defined as Z-axis. The line through the origin, perpendicular to the symmetric plane and XZ-plane are defined as X-axis and Y-axis respectively. Some important geometric parameters of the head-model are measured accurately by the digital model such as distance between all pairs of acupoints and interior angles from a triangulation of the acupoints in order to assistant locating the acupoints well. The proposed strategy in this study provides powerful weapons for acupoints location in Traditional Chinese Medicine.

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