Browsing by Author "Cho, Hsun-Jung"

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A circuit simulation technique for congested network traffic assignment problem
(2007)
Cho, Hsun-Jung
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Huang, Heng
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
The relation between electrical circuit and traffic network has been proposed by Sasaki and Inouye, but they proposed link cost function is a linear function which cannot present the congestion situation. Cho and Huang extended the link cost function to a nonlinear function which can explain the congested network. In this paper, we proposed a foremost and novel approach to solve the traffic assignment problem (TAP) by simulating the electrical circuit network which consists of nonlinear link cost function models. Comparing with the solutions of Frank-Wolfe algorithm, the simulation results are nearly identical. Thus, the simulation of a network circuit model can be applied to solve network traffic assignment problems. Finally, two examples are proposed, and the results confirmed that electrical circuit simulation is workable in solving congested network traffic assignment problems.
A circuit simulation technique for network assignment problem
(2005)
Cho, Hsun-Jung
;
Lee, Tsu-Tian
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Huang, Heng
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
In this paper, under the network user equilibrium principle (Wardrop, 1952), a method to use the analogous electric circuit to simulate network traffic assignment, and to measure the current flow and voltage of the electric circuit to present the result of traffic assignment is proposed. The basic ideas are using the resistance and constant voltage source combines the analogous electric circuit and using the current source presents the net traffic flow. Also, the nonlinear link cost function is approximated by the piecewise function. Finally, an example shows that an electric circuit simulating the network traffic assignment is workable.
A Fuel-Efficient Route Plan Method Based on Game Theory
(2019-01-01)
Lo, Chi-Lun
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Chen, Chi-Hua
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Hu, Jin-Li
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Lo, Kuen-Rong
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Cho, Hsun-Jung
This study adopts a fuel consumption estimation method to measure the consumed fuel quantity of each vehicle speed interval (i.e., a cost function) in accordance with individual behaviors. Furthermore, a mobile app is designed to consider the best responses of other route plan apps (e.g., the shortest route plan app and the fast route plan app) and plan the most fuel-efficient route according to the consumed fuel quantity. The numerical analysis results show that the proposed fuel-efficient route plan app can effectively support fuel-saving for logistics industries.
A genetic algorithm for the maximum edge-disjoint paths problem
(2015-01-19)
Hsu, Chia-Chun
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Cho, Hsun-Jung
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Optimization problems concerning edge-disjoint paths have attracted considerable attention for decades. These problems have a lot of applications in the areas of call admission control, real-time communication, VLSI (Very-large-scale integration) layout and reconfiguration, packing, etc. The maximum edge-disjoint paths problem (MEDP) seems to lie in the heart of these problems. Given an undirected graph G and a set of I connection requests, each request consists of a pair of nodes, MEDP is an NP-hard problem which determines the maximum number of accepted requests that can be routed by mutually edge-disjoint (s(i),t(i)) paths. We propose a genetic algorithm (GA) to solve the problem. In comparison to the multi-start simple greedy algorithm (MSGA) and the ant colony optimization method (ACO), the proposed GA method performs better in most of the instances in terms of solution quality and time. (C) 2014 Elsevier B.V. All rights reserved.
A hybrid shortest path algorithm for navigation system
(2007)
Cho, Hsun-Jung
;
Lan, Chien-Lun
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Combined with Geographic Information System (GIS) and Global Positioning System (GPS), the vehicle navigation system had become a quite popular product in daily life. A key component of the navigation system is the Shortest Path Algorithm. Navigation in real world must face a network consists of tens of thousands nodes and links, and even more. Under the limited computation capability of vehicle navigation equipment, it is difficult to satisfy the real-time response requirement that user expected. Hence, this study focused on shortest path algorithm that enhances the computation speed with less memory requirement. Several well-known algorithms such as Dijkstra, A* and hierarchical concepts were integrated to build hybrid algorithms that reduce searching space and improve searching speed. Numerical examples were conducted on Taiwan highway network that consists of more than four hundred thousands of links and nearly three hundred thousands of nodes. This real network was divided into two connected sub-networks (layers). The upper layer is constructed by freeways and expressways- the lower layer is constructed by local networks. Test origin-destination pairs were chosen randomly and divided into three distance categories; short, medium and long distances. The evaluation of outcome is judged by actual length and travel time. The numerical example reveals that the hybrid algorithm proposed by this research might be tens of thousands times faster than traditional Dijkstra algorithm; the memory requirement of the hybrid algorithm is also much smaller than the tradition algorithm. This outcome shows that this proposed algorithm would have an advantage over vehicle navigation system.
A new multicollinearity diagnostic for generalized linear models
(2016)
Huang, Chien-Chia L.
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Jou, Yow-Jen
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Cho, Hsun-Jung
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運輸與物流管理系註：原交通所+運管所
;
資訊管理與財務金融系註：原資管所+財金所
We propose a new collinearity diagnostic tool for generalized linear models. The new diagnostic tool is termed the weighted variance inflation factor (WVIF) behaving exactly the same as the traditional variance inflation factor in the context of regression diagnostic, given data matrix normalized. Compared to the use of condition number (CN), WVIF shows more reliable information on how severe the situation is, when data collinearity does exist. An alternative estimator, a by-product of the new diagnostic, outperforms the ridge estimator in the presence of data collinearity in both aspects of WVIF and CN. Evidences are given through analyzing various real-world numerical examples.
A passing probability model for intelligent transportation system
(2007)
Cho, Hsun-Jung
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Li, Rih-Jin
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
Intelligent transportation system (ITS) uses electronic technologies such as information and communication technologies to improve the efficiency of transportation management. In the theoretical framework of gas-kinetic traffic flow model, the probability of capable passing is essential for ITS. The probability of capable passing is assumed be a linear function of the traffic concentration, indicating that the probability of capable passing decreases proportionally with an increasing concentration. This work improves the model by introducing the speed desired by the driver into the original two-lane cellular automata (CA) model. This study also examines the accuracy of the linearity assumption. A capable passing principle is established to simulate the capable passing probability for different concentrations and can be embedded in a system on chip of ITS.
A support vector machine approach to CMOS-based radar signal processing for vehicle classification and speed estimation
(2013-07-01)
Cho, Hsun-Jung
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Tseng, Ming-Te
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
In this work, a complementary metal-oxide semiconductor (CMOS) based transceiver with a sensitivity time control antenna is successfully implemented for advanced traffic signal processing. The collected signals from the CMOS radar system are processed with optimization algorithms for vehicle-type classification and speed determination. The high recognition rate optimization algorithms are mainly based upon the information of short setup time and different environmental installation of each sensor. In the course of optimization, a video recognition module is further adopted as a supervisor of support vector machine and support vector regression. Compared with conventional circuit-based detector systems, the developed CMOS radar integrates submicron semiconductor devices and thus not only possesses low stand-by power but also is ready for production. In the meantime, the developed algorithm of this study simultaneously optimizes the vehicle-type classification and speed determination in a computationally cost-effective manner, which benefits real-time intelligent transportation systems. (C) 2013 Published by Elsevier Ltd
A VIF-based optimization model to alleviate collinearity problems in multiple linear regression
(2014-12-01)
Jou, Yow-Jen
;
Huang, Chien-Chia Liam
;
Cho, Hsun-Jung
;
運輸與物流管理系註：原交通所+運管所
;
資訊管理與財務金融系註：原資管所+財金所
In this paper, we address data collinearity problems in multiple linear regression from an optimization perspective. We propose a novel linearly constrained quadratic programming model, based on the concept of the variance inflation factor (VIF). We employ the perturbation method that involves imposing a general symmetric non-diagonal perturbation matrix on the correlation matrix. The proposed VIF-based model reduces the largest VIF by minimizing the resulting biases. The VIF-based model can mitigate the harm from data collinearity through the reduction in both the condition number and VIFs, meanwhile improving the statistical significance. The resulting estimator has bounded biases under an iterative framework and hence is termed the least accumulative bias estimator. Certain potential statistical properties can be further considered as the side constraints for the proposed model. Various numerical examples validate the proposed approach.
An improved efficiency of the Frank-Wolfe algorithm for network traffic assignment
(2006)
Cho, Hsun-Jung
;
Chen, Yu-Kuang
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Frank-Wolfe (denoted as F-W) algorithm has already been pointed out that the wrong traffic assignment will occur when parsing the statc of user equilibrium (denoted as UE). Besides, to obviate the non-UE paths by path data structure has been demonstrated to accelerate the rate of convergent speed. Therefore, how to decide a suitable threshold to shift. the flow from the Don-UE path to the other paths of the same origin-destination (denoted as OD) pair becomes a very important issue to enhance the rate of convergence. In this paper, an adequate threshold is proposed.
Difference-based matrix perturbation method for semi-parametric regression with multicollinearity
(2017-01-01)
Huang, Chien-Chia L.
;
Jou, Yow-Jen
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Cho, Hsun-Jung
;
運輸與物流管理系註：原交通所+運管所
;
資訊管理與財務金融系註：原資管所+財金所
This paper addresses the collinearity problems in semi-parametric linear models. Under the difference-based settings, we introduce a new diagnostic, the difference-based variance inflation factor (DVIF), for detecting the presence of multicollinearity in semi-parametric models. The DVIF is then used to device a difference-based matrix perturbation method for solving the problem. The electricities distribution data set is analyzed, and numerical evidences validate the effectiveness of the proposed method.
Estimating Individual Vehicle Speed by FMCW Radar Detector
(2009)
Cho, Hsun-Jung
;
Huang, Heng
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
For a side-looking frequency-modulated continuous wave (FMCW) radar detector, the information of vehicle speed can not be obtained by Doppler frequency directly. This is due to the detector is perpendicular to marching direction vehicle, therefore, Doppler shift of the beat signal is unapparent. Consequently, the length of detection zone, vehicle length, and the on-time duration of vehicle are three parameters in estimating individual vehicle speed by FMCW radar detectors. Among these parameters, vehicle length and detector on-time can be acquired by time-frequency signal analysis and statistical pattern recognition techniques. Therefore, how to determine the length of detection zone is the remaining problem. In this study, a method of estimating the length of detection zone based on antenna pattern and radar equation is proposed. According to the antenna pattern, the antenna gain is a function of angles in azimuth (phi), and elevation (theta) planes, such as G(phi, theta). For each point on the road surface, based on the radar equation, the relative received power can be calculated as long as the position and angle of the detector are given. After setting a threshold value of the relative received power, the length of detection zone on each lane can be determined. In field test, a side-looking 10.5 GHz FMCW radar is used to detect vehicles and the antenna pattern is given. The radar detector is installed at 6 meters height and the angle of depression is nearly 20 degrees. Based on the method described above and set the threshold value equal to 0.0015, then the length of detection zone on each lane can be obtained. According to the length of detection zone, vehicle length, and the on-time duration, the speed of each vehicle can be estimated. Moreover, the accuracy of lane 1 and lane 2 are 84.46% and 83.48% respectively.
Evaluating the performance of privatization on regional transit services: Case study
(2007-06-01)
Cho, Hsun-Jung
;
Fan, Chih-Ku
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
In this study, we propose three categories of productivity measures of changes in production, service, and consumption following privatization of the Taiwan Motor Transport Company. The results indicate that privatization had a striking impact in terms of total factor productivity on various productivity growths. The results also demonstrate that technical change was the most important factor in the progress in productivity of the new owner, the Guo Gwang Bus Company, while change in efficiency or effectiveness contributed little to this growth. However, results further suggest that the insignificant increase in efficiency and effectiveness in the newly privatized firm may be attributed either to incorrect selection of input combinations or inappropriate returns to scale, or to both.
Finding the I mu-user Equilibrium Solution Using an Augmented Frank-Wolfe Algorithm
(2010-12-01)
Cho, Hsun-Jung
;
Chen, Yu-Kuang
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
The Frank-Wolfe algorithm has been extensively adopted in recent decades to solve the user-equilibrium problem because of its simple structure and low memory requirements. However, Dial observed that the results obtained by the Frank-Wolfe algorithm differed markedly from the B algorithm of Dial in terms of link flows, and the results obtained via Frank-Wolfe algorithm could be incorrect. This study attempts to provide a clear example showing that the Frank-Wolfe algorithm has difficulty in achieving an I mu-user equilibrium state when I mu is sufficiently small. An Augmented Frank-Wolfe algorithm is presented that overcomes the weaknesses of the conventional arc-based Frank-Wolfe algorithm.
Finding the I mu-user Equilibrium Solution Using an Augmented Frank-Wolfe Algorithm
(2010-12-01)
Cho, Hsun-Jung
;
Chen, Yu-Kuang
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
The Frank-Wolfe algorithm has been extensively adopted in recent decades to solve the user-equilibrium problem because of its simple structure and low memory requirements. However, Dial observed that the results obtained by the Frank-Wolfe algorithm differed markedly from the B algorithm of Dial in terms of link flows, and the results obtained via Frank-Wolfe algorithm could be incorrect. This study attempts to provide a clear example showing that the Frank-Wolfe algorithm has difficulty in achieving an I mu-user equilibrium state when I mu is sufficiently small. An Augmented Frank-Wolfe algorithm is presented that overcomes the weaknesses of the conventional arc-based Frank-Wolfe algorithm.
Fuel Consumption Estimation System and Method with Lower Cost
(2017-07-01)
Lo, Chi-Lun
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Chen, Chi-Hua
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Kuan, Ta-Sheng
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Lo, Kuen-Rong
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Cho, Hsun-Jung
This study proposes a fuel consumption estimation system and method with lower cost. On-board units can report vehicle speed, and user devices can send fuel information to a data analysis server. Then the data analysis server can use the proposed fuel consumption estimation method to estimate the fuel consumption based on driver behaviours without fuel sensors for cost savings. The proposed fuel consumption estimation method is designed based on a genetic algorithm which can generate gene sequences and use crossover and mutation for retrieving an adaptable gene sequence. The adaptable gene sequence can be applied as the set of fuel consumption in accordance with the pattern of driver behaviour. The practical experimental results indicated that the accuracy of the proposed fuel consumption estimation method was about 95.87%.
Hybrid shortest path algorithm for vehicle navigation
(2009-08-01)
Cho, Hsun-Jung
;
Lan, Chien-Lun
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Vehicle navigation is one of the important applications of the single-source single-target shortest path algorithm. This application frequently involves large scale networks with limited computing power and memory space. In this study, several heuristic concepts, including hierarchical, bidirectional, and A(*), are combined and used to develop hybrid algorithms that reduce searching space, improve searching speed, and provide the shortest path that closely resembles the behavior of most road users. The proposed algorithms are demonstrated on a real network consisting 374,520 nodes and 502,485 links. The network is preprocessed and separated into two connected subnetworks. The upper layer of network is constructed with high mobility links, while the lower layer comprises high accessibility links. The proposed hybrid algorithms are implemented on both PC and hand-held platforms. Experiments show a significant acceleration compared to the Dijkstra and A(*) algorithm. Memory consumption of the hybrid algorithm is also considerably less than traditional algorithms. Results of this study showed the hybrid algorithms have an advantage over the traditional algorithm for vehicle navigation systems.
Incomplete information analysis for the origin-destination survey table
(2006-12-01)
Jou, Yow-Jen
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Cho, Hsun-Jung
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Lin, Pei-Wei
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Wang, Chih-Yin
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統計學研究所
Sampling is one approach used to survey the origin-destination (O-D) trip matrix. However, when the sampling rate is not sufficiently large compared to the population, the sampling data may have missing values in O-D pairs and that makes the O-D matrix incomplete. Two imputation methods to solve the problem mentioned previously are presented in this study. The Deming-Stephan (D-S) proportional fitting procedure is a statistical method first proposed to impute the missing value in this study. The improved D-S method, its convergence is proved by Cauchy criteria in this study, applies the iteration conception in the D-S method to solve the incomplete data problem. One numerical example displayed in this study shows that the improved D-S method produces an estimated O-D table with similar pattern as that of the population table.
Method for identification of traffic lane boundary
(2010-06-24)
Jou, Yow-Jen
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Cho, Hsun-Jung
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Chen, Yu-Kuang
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Huang, Heng
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Hsu, Chia-Chun
The invention provides a method for identification of traffic lane boundary. Firstly the microwave signal is received, and the noise reduction is treated for the microwave signal. Then the frequency domain information is employed to calculate the legal set of closed interval, in order to form the frequency span information. Finally, the probability density function model is employed to calculate the frequency span information in order to identify the traffic lane boundary.
Microscopic analysis of desired-speed car-following phenomena
(2005)
Cho, Hsun-Jung
;
Wu, Yuh-Ting
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
A car-following model is proposed in. this paper. The proposed model presents a new concept to describe car-following process. Repulsion and thrust act on a following vehicle, and the following vehicle chooses an appropriate speed under the repulsion and the thrust. Illustrative simulations are presented. The simulation result indicates that the proposed model is reasonable, and it can reflect some traffic flow phenomena, such as local stability, asymptotically stability, closing-in, and shying-away. It is worth mentioning that the proposed model employ driver desired speed as model variable so that the proposed model can explain why drivers keep different speeds or different gaps under the same condition. The proposed microscopic model can be the research basis of macroscopic traffic flow model.