Browsing by Author "Lan, Lawrence W."

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A joint measurement of efficiency and effectiveness for non-storable commodities: Integrated data envelopment analysis approaches
(2010-03-01)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Yen, Barbara T. H.
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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
Efficiency and effectiveness for non-storable commodities represent two distinct dimensions and a joint measurement of both is necessary to fully capture the overall performance. This paper proposes two novel integrated data envelopment analysis (IDEA) approaches, the integrated Charnes, Cooper and Rhodes (ICCR) and integrated Banker, Charnes and Cooper (IBCC) models, to jointly analyze the overall performance of non-storable commodities under constant and variable returns to scale technologies. The core logic of the proposed models is simultaneously determining the virtual multipliers associated with inputs, outputs, and consumption by additive specifications for technical efficiency and service effectiveness terms with equal weights. We show that both ICCR and IBCC models possess the essential properties of rationality, uniqueness, and benchmarking power. A case analysis also demonstrates that the proposed novel IDEA approaches have higher benchmarking power than the conventional separate DEA approaches. More generalized specifications of IDEA models with unequal weights are also elaborated. (C) 2009 Elsevier B.V. All rights reserved.
A Novel Method to Predict Traffic Features Based on Rolling Self-Structured Traffic Patterns
(2014-10-02)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Tseng, Chun-Ming
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交大名義發表
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運輸與物流管理系註：原交通所+運管所
In this study, a novel method is proposed to predict the traffic features in a long freeway corridor with a number of time steps ahead. The proposed method, on the basis of rolling self-structured traffic patterns, utilizes the growing hierarchical self-organizing map model to partition the unlabeled traffic patterns into an appropriate number of clusters and then develops the genetic programming model for each cluster to predict its corresponding traffic features. For demonstration, the proposed method is tested against a 110-km freeway stretch, on which 48 time steps of 5-min traffic flows are predicted (i.e., a 4-h prediction). The prediction accuracy of the proposed method is compared with other models (ARIMA, SARIMA, and naive models) and the results support the superiority of the proposed method. Further analyses indicate that applications of the proposed method to larger scale freeway networks require sufficient lengths of observation to acquire enough traffic patterns for training and validation in order to achieve higher prediction accuracy.
A refined cellular automaton model to rectify impractical vehicular movement behavior
(2009-09-15)
Lan, Lawrence W.
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Chiou, Yu-Chiun
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Lin, Zih-Shin
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Hsu, Chih-Cheng
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運輸與物流管理系註：原交通所+運管所
When implementing cellular automata (CA) into a traffic simulation, one common defect yet to be rectified is the abrupt deceleration when vehicles encounter stationary obstacles or traffic jams. To be more in line with real world vehicular movement, this paper proposes a piecewise-linear movement to replace the conventional particle-hopping movement adopted in most previous CA models. Upon this adjustment and coupled with refined cell system, a new CA model is developed using the rationale of Forbes' et al. car-following concept. The proposed CA model is validated on a two-lane freeway mainline context. It shows that this model can fix the unrealistic deceleration behaviors, and thus call reflect genuine driver behavior in the real world. The model is also capable of revealing Kerner's three-phase traffic patterns and phase transitions among them. Furthermore, the proposed CA model is applied to simulate a highway work zone wherein traffic efficiency (maximum flow rates) and safety (speed deviations) impacted by various control schemes are tested. (C) 2009 Elsevier B.V. All rights reserved.
A REFINED PARSIMONY PROCEDURE TO INVESTIGATING NONLINEAR TRAFFIC DYNAMICS
(2005)
Lan, Lawrence W.
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Huang, Yi-San
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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
This paper refines the parsimony procedure developed by Lan et al. (2005) and revisits the nonlinear features of real-world traffic dynamics in different contexts. The refined procedure begins with filtering out the periodic and quasi-periodic patterns by Fourier power spectrum, then filtering out the equilibrium (fixed) points by largest Lyapunov exponent, and finally distinguishing chaoticity from stochasticity by iterated function system clumpiness maps between original and surrogate flow time series data. An empirical analysis of traffic flow data measured with various time intervals (20-second, one-minute, three-minute and nine-minute) during different times of day (midnight, morning, afternoon and evening) are examined. The results show that different nonlinear patterns may emerge or vanish, depending on the measured intervals and times of day. Traffic patterns in the morning (6:00 to 9:00 am) and evening (18:00 to 21:00 pm) periods are close to chaotic phenomena. During the afternoon off-peak period (12:00 to 15:00 pm), the pattern is close to stochastic phenomenon. The 20-second traffic pattern at midnight (0:00 to 3:00 am) is close to equilibrium point due to copious zero flows.
A rolling-trained fuzzy neural network approach for freeway incident detection
(2006)
Lan, Lawrence W.
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Huang, Yeh-Chieh
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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
This paper develops a rolling-trained fuzzy neural network (RTFNN) approach for freeway incident detection. The core logic of this approach is to establish a fuzzy neural network and to update the network parameters in response to the prevailing traffic conditions through a rolling-trained procedure. The simulation results of some thirty-six incident scenarios in a two-lane freeway mainline case study show that the proposed RTFNN approach can improve the detection performance over the fuzzy neural network approach, which is based on the same network structure but without updating the parameters through a rolling-trained procedure. The highest detection rate is found at a rolling horizon of 45 minutes and a training sample size of 90 samples in this case study.
A two-stage mining framework to explore key risk conditions on one-vehicle crash severity
(2013-01-01)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Chen, Wen-Pin
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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
This paper proposes a two-stage mining framework to explore the key risk conditions that may have contributed to the one-vehicle crash severity in Taiwan's freeways. In the first stage, a genetic mining rule (GMR) model is developed, using a novel stepwise rule-mining algorithm, to identify the potential risk conditions that best elucidate the one-vehicle crash severity. In the second stage, a mixed logit model is estimated, using the antecedent part of the mined-rules as explanatory variables, to test the significance of the risk conditions. A total of 5563 one-vehicle crash cases (226 fatalities, 1593 injuries and 3744 property losses) occurred in Taiwan's freeways over 2003-2007 are analyzed. The GMR model has mined 29 rules for use. By incorporating these 29 mined-rules into a mixed logit model, we further identify one key safe condition and four key risk conditions leading to serious crashes (i.e., fatalities and injuries). Each key risk condition is discussed and compared with its adjacent rules. Based on the findings, some countermeasures to rectify the freeway's serious one-vehicle crashes are proposed. (C) 2012 Elsevier Ltd. All rights reserved.
An integrated container management model for optimizing slot allocation plan and empty container repositioning
(2015-09-01)
Chang, Chia-hui
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Lan, Lawrence W.
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Lee, Mee
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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
This article proposes an integrated container management model to jointly optimize slot allocation plan for loaded containers and reposition for empty containers in a shipping network. The proposed model employs linear programming to formulate loaded and empty container shipping problems in a bi-level structure. In upper level the loaded container slot allocation plan aims to maximize operational profits for each service route; whereas in lower level the reposition of empty containers aims to minimize transportation costs for the entire shipping network. The surplus or deficient empty containers resulted from the upper problem are fed into the lower problem. To demonstrate the applicability of the proposed model, a real case of an intra-Asian short-sea container carrier is presented. The results show that the proposed model can serve as a decision support tool to facilitate the liner to ship the loaded and empty containers in a coordinative way.
AN OPTIMAL SIGNAL CONTROL MODEL CONSIDERING EMISSION CONCENTRATION IN MIXED TRAFFIC CONTEXTS
(2012-01-01)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Hsieh, Chih-Wei
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Wu, Yi-Jie
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運輸與物流管理系註：原交通所+運管所
An optimal signal control model is proposed that minimizes the traffic emissions with restricted emission concentration in environment-sensitive areas where cars and motorcycles are prevailing. The proposed model comprises four sub-models: mixed traffic cell-transmission model, traffic emission model, Gaussian puff dispersion model, and stepwise genetic fuzzy logic controller model. Mixed traffic behaviors are replicated by the mixed traffic cell-transmission model, traffic emissions are estimated by TEDS 7.0 line source emissions database, emission concentration is estimated by the Gaussian puff model, and optimal cycle length and time split are solved by the stepwise genetic fuzzy logic controller model. Performance of the proposed model is tested at an experimental intersection as oppose to a pre-timed signal control strategy as the baseline. The results show that the proposed model has outperformed in reducing the emission concentration.
Assessing the on-road route efficiency for an air-express courier
(2010-10-01)
Lin, Erwin T. J.
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Lan, Lawrence W.
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Hsu, Cathy S. T.
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管理學院
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College of Management
This paper proposes an EXO-CAT data envelopment analysis (DEA) model to evaluate the efficiency of on-road activities (pickup and delivery) for an air-express courier on a route-by-route basis. The proposed model combines the constraints of exogenously fixed inputs DEA and categorical DEA to account for the continuous and discrete external environmental factors affecting the courier route efficiency. We select labor, route length (a proxy of fuel consumption), and vehicle capacity as the inputs; number of documents delivered, number of boxes delivered, number of documents picked-up, and number of boxes picked-up as the outputs. A case study with 248 on-road routes currently operated by an air-express courier in Taiwan is undertaken. It is found that stop density, travel speed, and service area type have significant influences on the couriers' route efficiency. Based on the detailed DEA results, the managers do not need to perform check-rides for all routes; instead, they need only to focus on the most inefficient ones. Such DEA results can also be applied to develop new projects or make judgments on investing any new on-road routes. Copyright C 2010 John Wiley & Sons, Ltd.
Cellular automaton simulations for mixed traffic with erratic motorcycles' behaviours
(2010-05-15)
Lan, Lawrence W.
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Chiou, Yu-Chiun
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Lin, Zih-Shin
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Hsu, Chih-Cheng
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運輸與物流管理系註：原交通所+運管所
Modeling mixed traffic composed of motorcycles can be a challenging issue because many erratic motorcyclists may not follow the lane disciplines, particularly when traffic is congested. Based upon the refined cellular automaton (CA) model recently developed by the authors [LW. Lan, Y C Chiou. Z.S. Lin, C.C. Hsu, Physica A 388 (2009) 3917-3930], this paper further proposed a sophisticated CA model to elucidate the erratic motorcycle behaviours in mixed traffic contexts. In addition to the conventional moving forward and lane-change rules, the sophisticated CA model also explicated the lateral drift behaviour for cars moving in the same lane, the lateral drift behaviour for motorcycles breaking into two moving cars. and the transverse crossing behaviour for motorcycles through the gap between two stationary cars in the same lane. Fundamental diagrams and space-time trajectories for vehicles with various car-motorcycle mixed ratios are demonstrated (C) 2010 Elsevier B.V. All rights reserved
CONFINED SPACE FUZZY PROPORTION MODEL FOR SHORT-TERM TRAFFIC FLOW PREDICTION
(2004)
Lan, Lawrence W.
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Lin, Feng-Yu
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Huang, Yi-San
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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
This paper develops a confined space fuzzy proportion (CSFP) model to predict the short-term traffic flow dynamics. The rationale for prediction reasoning is based on the "fuzzy proportion" inference from similar historical trajectories that are within a "confined space" defined by a spatial threshold in the reconstructed state space. To perform the inference, we assign to each trajectory with unequal weight that is proportional to the relative distance to the latest (present) data vector. The United States I-35 Freeway one-minute flow data are used to construct and validate the proposed model. We employ Theil inequality coefficient (U) and its decomposed proportions to evaluate the prediction performance and to analyze the sources of prediction errors. The empirical results have demonstrated extremely high predictive capability of this CSFP model. The small bias and variance proportions of U statistic further indicate that the prediction model can successfully capture the trends and conspicuous fluctuations of one-minute traffic flow variations.
DEVELOPMENT OF OPTIMAL VARIABLE SPEED-LIMIT CONTROL MODEL
(2009)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Lin, Po-Cheng
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Huang, Yen-Fei
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運輸與物流管理系註：原交通所+運管所
Application of variable speed-limit (VSL) control has become promising in managing the incidents in the contexts of intelligent highway systems wherein advanced VSL signs are densely placed along the roadways. This paper aims to develop a genetic-fuzzy-logic-controller (GFLC)-based VSL control model with an objective function to enhance both safety and throughput efficiency at the incident sites. In order to evaluate the performance of learned logic rules and tuned membership function, a revised cell transmission model (CTM) is proposed, which is validated with field traffic data. The results indicate that the proposed VSL control model can effectively curtail the crash likelihood without deteriorating or only slightly decreasing the throughput efficiency under different tested incident cases. It suggests that our proposed GFLC-based VSL control model is promising for practical applications.
EFFECTS OF TEMPORALLY DIFFERENTIAL FARES ON TAIPEI METRO RIDERS' MODE AND TIME-OF-DAY CHOICES
(2010-02-01)
Lan, Lawrence W.
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Lee, Hsiang-Yi
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Wen, Chieh-Hua
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交大名義發表
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National Chiao Tung University
Introducing temporally differential fares to shift a portion of peak-hour demand to off-peak hours shows promise in mitigating the overcrowded Taipei Metro system during peak hours. This study looked to elucidate how Taipei Metro riders would change their times of travel or use of other travel modes, should peak-hour surcharge or off-peak discount fare schemes be introduced Multinomial logit and nested lop models were employed to depict the riders' stated behavior, in terms of arrival times and mode choices, within the context of a scenario involving tested differential fare levels Results showed that introducing temporally differential fares would prompt a portion of peak-hour Metro riders to shift to off-peak periods, or even to choose the use of other modes The Metro riders were sensitive to the tested differential fare levels, especially the peak-hour surcharge The afternoon riders were more sensitive to proposed fare changes than the morning riders To implement the temporally differential fares successfully within the Metro system, it is suggested that peak hours be carefully designated and that peak-hour riders be clearly distinguished from off-peak riders
ESTIMATION OF FREEWAY DYNAMIC ORIGIN-DESTINATION MATRICES: A NOVEL APPROACH
(2010)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Tseng, Chun-Ming
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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
This paper proposes a novel approach to estimate medium-to-long term freeway dynamic origin-destination (O-D) matrices. The proposed approach includes a two-stage prediction model with an integrated algorithm. The two-stage prediction model uses K-means algorithm to extract clusters of traffic patterns and then employs genetic programming to predict the traffic in each cluster. The integrated algorithm combines cell transmission model with extended Kalman filtering to estimate the arrival distributions and the O-D proportions. To demonstrate the applicability of the proposed approach, a field study of on-ramp traffic patterns on a freeway is examined. The results show that the proposed approach can accurately predict the traffic and satisfactorily estimate the O-D proportions along a freeway.
EXPLORATION OF TRAFFIC PHASES
(2008)
Huang, Yi-San
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Lan, Lawrence W.
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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
Without considering the traffic stream evolution, conventional traffic stream diagrams may provide incomplete information for real-time traffic management and control applications. This study aims to add evolutionary information into the traffic stream diagrams by ordering chronologically the paired-traffic parameters and to explore the emerged traffic phases and their transitions. The flow, speed, and occupancy raw data directly extracted from dual-loop detectors on freeway at various times of day are investigated. Our investigations show that traffic stream characteristics do exhibit various phases, including free-flow phase, synchronized-flow phase, and breakdown phenomenon-an unstable phase that plays a transitive role between free-flow phase and synchronized-flow phase. Our exploration of traffic phases with consideration of traffic stream evolution has shed some light on the development of advanced real-time traffic management/control strategies.
Exploring decisive factors affecting an organization's SaaS adoption: A case study
(2011-12-01)
Wu, Wei-Wen
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Lan, Lawrence W.
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Lee, Yu-Ting
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交大名義發表
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National Chiao Tung University
Software as a Service (SaaS) is regarded as a favorable solution to enhance a modern organization's IT performance and competitiveness; however, many organizations may still be reluctant to introduce SaaS solutions mainly because of the trust concern they may perceive more risks than benefits. This paper presumes that an organization will augment the trust of adopting SaaS solutions when perceived risks decrease and/or perceived benefits increase. To gain insights into this issue, a solution framework using a modified Decision Making Trial and Evaluation Laboratory (DEMATEL) approach is proposed. The core logic is to treat perceived benefits and perceived risks as two distinct themes so that a visible cause-effect diagram can be developed to facilitate the decision makers. A case study is conducted on a Taiwanese company one of the world's leading manufacturers in the niche and specialized resistor markets. The findings suggest that the case company concern more about strategic-oriented benefits than economic-oriented benefits and more about subjective risks than technical risks. Some implications are addressed accordingly. (C) 2011 Elsevier Ltd. All rights reserved.
FACTORS AFFECTING USAGE OF HIGH-EMITTING CARS AND MOTORCYCLES IN TAIWAN
(2008)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Chen, Tai-Chieh
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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
To investigate the significant factors affecting the usage of high-emitting cars and motorcycles in Taiwan, this paper conducts a nationwide post-mailed questionnaire survey on the owners of cars and motorcycles; each vehicle type contains 45 thousand samples drawn from Taiwan's Vehicle Registration Database. A total of 3,454 car samples and 2,856 motorcycle samples are returned. We further match these returned samples with Taiwan's Vehicle Inspection and Management Database according to the license plate number. Some 748 car samples and 1,322 motorcycle samples have been successfully matched, which are further used to build up structural equation models for testing the cause-effect hypotheses between the latent constructs (sets of factors) and the usage of high-emitting vehicles. Our results show that the most influencing construct is the vehicle characteristics, which include old, small engine, manual transmission, high mileage, and 2-stroke engine (only for motorcycle) vehicles. The second most influencing construct is the driver/rider demographics, which includes aged, male, low-educated, high-income, and long-driving-experience people. Our results also show that emissions of cars are more serious in small cities than in large and medium cities; however, this relationship is not significantly existent in the motorcycle model.
GENETIC-ANT CLUSTERING ALGORITHMS
(2007)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Tsai, Pei-Shan
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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
This paper proposed a hybrid clustering algorithm, namely genetic-ant clustering algorithm (GACA), by hybridizing genetic algorithms (GAs) and ant colony system (ACS). The core logic of the proposed algorithm is to employ GAs to optimally determine cluster seeds and then use ACS to optimally assign the remaining objects to one of the cluster seeds. To compare the performance of proposed hybrid algorithm with other algorithms, a numerical study on various scales of clustering problems, including 50, 100 and 300 randomly generated two-dimension objects and a case study on a p-median problem containing 316 cities are conducted, respectively. Moreover, to examine the performance difference between the hierarchical and nonhierarchical clustering methods, additional capacity constraints are imposed. The results of the uncapacitated clustering example and p-median problem consistently show that, in term of effectiveness, our previously proposed hierarchical clustering method -- GCA-CSPM significantly performs best, followed by GACA. However, if the capacity constraint is further introduced, GACA will perform best, implying that GACA is suitable for solving more complex clustering problem which exists highly interacted relationships among objects.
IDENTIFYING RISK CONDITIONS TO CRASH SEVERITY: GENETIC MINING RULE APPROACH
(2010)
Chou, Yu-Chiun
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Lan, Lawrence W.
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Chen, Wen-Pin
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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
This paper proposes a two-stage analytical framework to identify the critical risk conditions contributing to crash severity. The first stage develops a genetic mining rule (GMR) model to identify possible risk conditions best elucidating the degree of severity. The second stage then uses the mined risk conditions as dummy explanatory variables to formulate an ordered Probit model. The proposed two-stage analytical framework is applied to analyze the Taiwan's empirical one-vehicle crash data. A total of 38 rules are mined, which can achieve overall prediction rates of 75.10% in training and 73.80% in validation. Based on the results, six most critical risk conditions are identified and the corresponding countermeasures are addressed.
Integrated fuzzy data envelopment analysis to assess transport performance
(2014-05-28)
Lan, Lawrence W.
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Chiou, Yu-Chiun
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Yen, Barbara T. H.
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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
Previous fuzzy data envelopment analysis (FDEA) models separately solving for the lower- and upper-bound efficiency frontiers under a specific alpha-cut level may lead to inconsistent efficiency rankings, unreasonable efficiency scores, and cumbersome slack computations. To rectify such shortcomings, this paper proposes two novel integrated fuzzy data envelopment analysis (IFDEA) models wherein both efficiency frontiers are incorporated into a single modelling formulation in ways that the slack values for lower- and upper-bound input/output variables are determined simultaneously. A numerical example shows that the proposed IFDEA models are more generalised and with greater simplicity than an existent FDEA model. A case study further demonstrates that the proposed IFDEA models can satisfactorily assess the relative efficiency for bus transport companies provided that a portion of the variables are measured qualitatively with vagueness (passenger satisfaction in this study).