scholarly journals Modeling and Analyzing Taxi Congestion Premium in Congested Cities

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Changwei Yuan ◽  
Dayong Wu ◽  
Dali Wei ◽  
Hongchao Liu
Keyword(s):  
Traffic Congestion ◽  
Supply And Demand ◽  
Price Equilibrium ◽  
Income Source ◽  
Taxi Drivers ◽  
Proposed Model ◽  
Demand Reduction ◽  
The Stability ◽  
The Impact

Traffic congestion is a significant problem in many major cities. Getting stuck in traffic, the mileage per unit time that a taxicab travels will decline significantly. Congestion premium (or so-called low-speed fare) has become an increasingly important income source for taxi drivers. However, the impact of congestion premium on the taxicab market is not widely understood yet. In particular, modeling and analyzing of the taxi fare structure with congestion premium are extremely limited. In this paper, we developed a taxi price equilibrium model, in which the adjustment mechanism of congestion premium on optimizing the taxi driver’s income, balancing the supply and demand, and eventually improving the level of service in the whole taxicab market was investigated. In the final part, we provided a case study to demonstrate the feasibility of the proposed model. The results indicated that the current taxi fare scheme in Beijing is suboptimal, since the gain from the raise of congestion premium cannot compensate for the loss from the demand reduction. Conversely, the optimal fare scheme suggested by our model can effectively reduce the excessive demand and reach the supply-demand equilibrium, while keeping the stability of the driver’s income to the maximum extent.

An improved car-following model considering the impact of safety messages

2018 ◽  
Vol 32 (32) ◽  
pp. 1850398 ◽  
Author(s):  
Tenglong Li ◽  
Fei Hui ◽  
Xiangmo Zhao
Keyword(s):  
Traffic Congestion ◽  
Dominant Factor ◽  
Velocity Difference ◽  
Car Following ◽  
Safety Message ◽  
Warning Messages ◽  
Gray Correlation ◽  
Car Following Model ◽  
The Stability ◽  
The Impact

The existing car-following models of connected vehicles commonly lack experimental data as evidence. In this paper, a Gray correlation analysis is conducted to explore the change in driving behavior with safety messages. The data mining analysis shows that the dominant factor of car-following behavior is headway with no safety message, whereas the velocity difference between the leading and following vehicle becomes the dominant factor when warning messages are received. According to this result, an extended car-following model considering the impact of safety messages (IOSM) is proposed based on the full velocity difference (FVD) model. The stability criterion of this new model is then obtained through a linear stability analysis. Finally, numerical simulations are performed to verify the theoretical analysis results. Both analytical and simulation results show that traffic congestion can be suppressed by safety messages. However, the IOSM model is slightly less stable than the FVD model if the average headway in traffic flow is approximately 14–20 m.

scholarly journals Applying a Model for Trip Assignment and Dynamic Routing of Automated Taxis with Congestion: System Performance in the City of Delft, The Netherlands

2018 ◽  
Vol 2672 (8) ◽  
pp. 588-598 ◽  
Author(s):  
Xiao Liang ◽  
Gonçalo Homem de Almeida Correia ◽  
Bart van Arem
Keyword(s):  
The Netherlands ◽  
Real Time ◽  
Traffic Congestion ◽  
Programming Model ◽  
Profit Maximization ◽  
The Real ◽  
Real Size ◽  
The Impact ◽  
The City

This paper proposes a method of assigning trips to automated taxis (ATs) and designing the routes of those vehicles in an urban road network, and also considering the traffic congestion caused by this dynamic responsive service. The system is envisioned to provide a seamless door-to-door service within a city area for all passenger origins and destinations. An integer programming model is proposed to define the routing of the vehicles according to a profit maximization function, depending on the dynamic travel times, which varies with the ATs’ flow. This will be especially important when the number of automated vehicles (AVs) circulating on the roads is high enough that their routing will cause delays. This system should be able to serve not only the reserved travel requests, but also some real-time requests. A rolling horizon scheme is used to divide one day into several periods in which both the real-time and the booked demand will be considered together. The model was applied to the real size case study city of Delft, the Netherlands. The results allow assessing of the impact of the ATs movements on traffic congestion and the profitability of the system. From this case-study, it is possible to conclude that taking into account the effect of the vehicle flows on travel time leads to changes in the system profit, the satisfied percentage and the driving distance of the vehicles, which highlights the importance of this type of model in the assessment of the operational effects of ATs in the future.

Lattice hydrodynamic model-based feedback control method with traffic interruption probability

2019 ◽  
Vol 33 (23) ◽  
pp. 1950273 ◽  
Author(s):  
Cong Zhai ◽  
Weitiao Wu
Keyword(s):  
Feedback Control ◽  
Hydrodynamic Model ◽  
Traffic Congestion ◽  
Control Method ◽  
Feedback Controller ◽  
Lattice Hydrodynamic Model ◽  
Feedback Control Method ◽  
The Stability ◽  
Probability Effect ◽  
The Impact

Connected vehicles are expected to become commercially available by the next decade, while traffic interruption is not uncommon in the real traffic environment. In this paper, we propose a feedback control method for lattice hydrodynamic model considering the traffic interruption probability effect. The stability criterion of the new model is explored through linear stability analysis of transfer function. When the stability conditions are not satisfied, a delay feedback controller is used to control the discharging flow to suppress traffic congestion. The impact of gain coefficient and delay time on the performance is discussed. We verify the effectiveness of the devised delay feedback controller by simulations. Results show that the traffic interruption probability effect has a considerable impact on the stability of traffic flow, while the controller is effective in suppressing traffic congestion.

Assessing design process in engineering consultancy firms using lean principles

SIMULATION ◽  
2012 ◽  
Vol 88 (12) ◽  
pp. 1522-1536 ◽  
Author(s):  
M Marzouk ◽  
I Bakry ◽  
M El-Said
Keyword(s):  
Design Process ◽  
Comprehensive Model ◽  
Output Analysis ◽  
Lean Principles ◽  
Proposed Model ◽  
Client Request ◽  
Using Data ◽  
Consultancy Firm ◽  
The Impact

The aim of this research is to provide a tool for assessing the impact of applying lean principles to the design process at construction consultancy firms. Through several interviews, a comprehensive model was built to simulate the design process, using data from a leading consultancy firm in Egypt. The model contains the main processes and activities that form different phases of the design process and depicts the interconnectivity of processes and activities needed to create a complete design package upon client request. The research describes how the five main lean principles are integrated in the model. A case study is considered to demonstrate the effect of using the proposed model on the design process and to illustrate how the design process performs differently when lean principles are introduced. Case study output analysis reveals 40% improvement in the lean process performance measured in terms of activity utilization rates.

Regional Impact on Technological Change: The Evolution and Development of the Twin-Wire Paper Machine from 1950 to 1988

1995 ◽  
Vol 27 (9) ◽  
pp. 1503-1520 ◽  
Author(s):  
B Ofori-Amoah
Keyword(s):  
North America ◽  
Supply And Demand ◽  
Raw Material ◽  
Paper Machine ◽  
Corporate Strategies ◽  
Paper Making ◽  
Evolution And Development ◽  
Consumer Tastes ◽  
The Impact

In this paper the impact of regions on the evolution and development of technology is examined via a new paper-making technology (the twin-wire machine) as a case study. In particular, differences in raw material and physical environmental conditions, consumer tastes and preferences, and industrial organization and corporate strategies between the two regions, North America and Europe, provided different demand and supply conditions for the development of the twin-wire technology. These conditions initially influenced the development of different twin-wire trajectories in North America and Europe. Later on, these trajectories began to converge as the supply and demand conditions, which had established them, began to change.

Impact of Residential and Public Charging Stations of Electric Vehicles on Distribution System by Stochastic Simulation

2015 ◽  
Vol 1092-1093 ◽  
pp. 375-380
Author(s):  
Suthida Ruayariyasub ◽  
Sompon Sirisumrannukul ◽  
Suksan Wangsatitwong
Keyword(s):  
Monte Carlo ◽  
Electric Vehicles ◽  
Distribution System ◽  
Stochastic Approach ◽  
Local Distribution ◽  
Battery Charging ◽  
Proposed Model ◽  
Charging Stations ◽  
The Impact

This paper investigates the impact of electric vehicles battery charging on the distribution system load if electric vehicles (EVs) are widespread used on roads. Stochastic approach based on a Monte Carlo method is developed in this study to simulate EVs charging load in two cases: 1) normal charge service at home, and 2) quick charge service at public charging stations. To demonstrate the model, a 22-kV distribution system of Pattaya City operated by Provincial Electricity Authority of Thailand (PEA) is employed in the case study. The results indicate the capability of the proposed model to exhibit the impact of EVs charging load on the local distribution system.

scholarly journals Prediction of the stability of proteins by computational approaches: a case report

2018 ◽  
Author(s):  
Bernardina Scafuri ◽  
Angelo Facchiano ◽  
Anna Marabotti
Keyword(s):  
Case Report ◽  
Protein Stability ◽  
Protein Sequence ◽  
Genotypic Variation ◽  
Missense Mutations ◽  
Computational Approaches ◽  
The Past ◽  
The Stability ◽  
The Impact

The prediction of the stability of a protein is a very important issue in computational biology. Indeed, missense mutations are frequently associated to a change in protein stability, leading usually to destabilization, unfolding and aggregation. However, the direct measurement of the effect of mutations on proteins' stability is often impaired by the large number of mutations that can affect a protein sequence. Therefore, predicting the impact of a mutation on this feature is of remarkable interest to infer the phenotypic effects associated to a genotypic variation. For this reason, many different predictors of the effects of mutations on protein stability have been developed during the past years, and they are available online as Web servers. In the present work, we applied several tools based on different approaches to predict the stability of three proteins involved in the different forms of the rare disease galactosemia, and we compare their different results, describing also the problems that we had to face, the solutions that we have adopted and the lessons learnt from this case study.

scholarly journals Impact of Guideline Markings on Saturation Flow Rate at Signalized Intersections

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Zhengtao Qin ◽  
Jing Zhao ◽  
Shidong Liang ◽  
Jiao Yao
Keyword(s):  
Flow Rate ◽  
Signalized Intersections ◽  
Estimation Model ◽  
Left Turn ◽  
Proposed Model ◽  
Research Goal ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
The Impact

Many intersections around the world are irregular crossings where the approach and exit lanes are offset or the two roads cross at oblique angles. These irregular intersections often confuse drivers and greatly affect operational efficiency. Although guideline markings are recommended in many design manuals and codes on traffic signs and markings to address these problems, the effectiveness and application conditions are ambiguous. The research goal was to analyze the impact of guideline markings on the saturation flow rate at signalized intersections. An adjustment estimation model was established based on field data collected at 33 intersections in Shanghai, China. The proposed model was validated using a before–after case study. The underlying reasons for the impact of intersection guideline markings on the saturation flow rate are discussed. The results reveal that the improvement in the saturation flow rate obtained from painting guide line markings is positively correlated with the number of traffic lanes, offset of through movement, and turning angle of left-turns. On average, improvements of 7.0% and 10.3% can be obtained for through and left-turn movements, respectively.

scholarly journals Systemic Risk in the Interbank Market with Overlapping Portfolios

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Shanshan Jiang ◽  
Hong Fan
Keyword(s):  
Interest Rate ◽  
Systemic Risk ◽  
Banking System ◽  
Bipartite Network ◽  
Investment Risk ◽  
Interbank Market ◽  
Operating Rules ◽  
Proposed Model ◽  
The Stability ◽  
The Impact

The increasing frequency and scope of the financial crisis have attracted more attention in the research of the systemic risk of banking system. A new model for the interbank market with overlapping portfolios is proposed to simulate a banking system in this work. The proposed model uses a bipartite network of banks and their assets to analyze the impact of bank investment on the stability of the banking system. In addition, this model introduces investment risk and allows banks to make up for liquidity by selling devaluated assets, which reflects the operating rules of the banking system more realistically. The results show that allowing banks to sell devaluated assets to make up for liquidity can improve the stability of the banking system and the interbank market can also improve the stability of the banking system. For the investment of banks, the investment risk is an uncertain factor that affects the stability of the banking system. The proposed model further analyzes the impact of average investment interest rate, savings interest rate, deposit reserve ratio, and investment asset diversity on the stability of the banking system. The model provides a tool for policy-makers and supervision agencies to prevent the systemic risk of banking system.

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