scholarly journals Capacity Analysis for Approach Channels Shared by LNG Carriers

2020 ◽  
Vol 8 (9) ◽  
pp. 697
Author(s):  
Xiang Gao ◽  
Linying Chen ◽  
Pengfei Chen ◽  
Yu Luo ◽  
Junmin Mou
Keyword(s):  
Traffic Management ◽  
Time Windows ◽  
Management Strategies ◽  
Capacity Analysis ◽  
Behavioral Characteristics ◽  
Traffic Capacity ◽  
Approach Channel ◽  
General Cargo ◽  
The Impact

The transport of liquefied natural gas (LNG) has significant impact on traffic capacity of waterways, especially the approach channels shared by LNG carriers and other types of ships (general cargo ships, container ships, etc.). Few studies take the behavioral characteristics of LNG carriers and their impacts into consideration. In this paper, we propose a framework for capacity analysis of shared approach channels based on the spatial–temporal consumption method. It consists of three modules: (1) the tide module predicts the tidal height and tidal time for identifying the time windows for LNG carriers; (2) the spatial–temporal consumption module is introduced to calculate the capacity of approach channels; (3) the LNG carrier navigation module is for analyzing the characteristics of LNG carriers and the impact on the capacity of approach channels. A spatial–temporal indexed chart is designed to visualize the utilization of the spatial–temporal resources. A case study on the approach channel of Yueqing Bay near the east coast of China is conducted to verify the effectiveness of the framework. The utilization rates of the approach channel and the impact of LNG carriers are presented using our method. The results of the case study indicate that the proposed traffic capacity analyzing framework can provide support for making traffic management strategies.

scholarly journals Probabilistic Strategic Conflict-Management for 4D Trajectories in Free-Route Airspace

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 159
Author(s):  
Javier Alberto Pérez-Castán ◽  
Álvaro Rodríguez-Sanz ◽  
Luis Pérez Sanz ◽  
Rosa M. Arnaldo Valdés ◽  
V. Fernando Gómez Comendador ◽  
...  
Keyword(s):  
Conflict Management ◽  
Traffic Management ◽  
Time Windows ◽  
Speed Control ◽  
Air Traffic ◽  
Traffic Management System ◽  
Operational Concept ◽  
The Impact ◽  
Strategic Conflict ◽  
Temporary Blocking

The expected growth of air traffic in the following decades demands the implementation of new operational concepts to avoid current limitations of the air traffic management system. This paper focuses on the strategic conflict management for four-dimensional trajectories (4DT) in free-route airspace. 4DT has been proposed as the future operational concept to manage air traffic. Thus, aircraft must fulfil temporary restrictions at specific waypoints in the airspace based on time windows. Based on the temporary restrictions, a strategic conflict management method is proposed to calculate the conflict probability of an aircraft pair (that intersects in the air) and to calculate temporary-blocking windows that quantify the time span at which an aircraft cannot depart because one conflict could occur. This methodology was applied in a case-study for an aircraft pair, including the uncertainty associated with 4DT. Moreover, a sensitivity analysis was performed to characterise the impact of wind conditions and speed control on the temporary-blocking windows. The results concluded that it is feasible to propose 4DT strategic de-confliction based on temporary-blocking windows. Although, uncertainty variables such as wind and speed control impact on the conflict probability and the size of the temporary-blocking windows.

Effectiveness of Predictive Weather-Related Active Transportation and Demand Management Strategies for Network Management

2017 ◽  
Vol 2667 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Zihan Hong ◽  
Hani S. Mahmassani ◽  
Xiang Xu ◽  
Archak Mittal ◽  
Ying Chen ◽  
...  
Keyword(s):  
Traffic Management ◽  
Demand Management ◽  
Management Strategies ◽  
Weather Conditions ◽  
Active Transportation ◽  
Operational Conditions ◽  
Traffic Conditions ◽  
Adverse Weather ◽  
Traffic Performance ◽  
The Impact

This paper presents the development, implementation, and evaluation of predictive active transportation and demand management (ATDM) and weather-responsive traffic management (WRTM) strategies to support operations for weather-affected traffic conditions with traffic estimation and prediction system models. First, the problem is defined as a dynamic process of traffic system evolution under the impact of operational conditions and management strategies (interventions). A list of research questions to be addressed is provided. Second, a systematic framework for implementing and evaluating predictive weather-related ATDM strategies is illustrated. The framework consists of an offline model that simulates and evaluates the traffic operations and an online model that predicts traffic conditions and transits information to the offline model to generate or adjust traffic management strategies. Next, the detailed description and the logic design of ATDM and WRTM strategies to be evaluated are proposed. To determine effectiveness, the selection of strategy combination and sensitivity of operational features are assessed with a series of experiments implemented with a locally calibrated network in the Chicago, Illinois, area. The analysis results confirm the models’ ability to replicate observed traffic patterns and to evaluate the system performance across operational conditions. The results confirm the effectiveness of the predictive strategies tested in managing and improving traffic performance under adverse weather conditions. The results also verify that, with the appropriate operational settings and synergistic combination of strategies, weather-related ATDM strategies can generate maximal effectiveness to improve traffic performance.

scholarly journals Understanding Taxi Drivers’ Multi-day Cruising Patterns

2015 ◽  
Vol 27 (6) ◽  
pp. 467-476 ◽  
Author(s):  
Fang Zong ◽  
Xiao Sun ◽  
Huiyong Zhang ◽  
Xiumei Zhu ◽  
Wentian Qi
Keyword(s):  
Traffic Management ◽  
Management Strategies ◽  
Traffic Volume ◽  
Gps Data ◽  
Taxi Drivers ◽  
Factors Influencing ◽  
Study Results ◽  
Crucial Information ◽  
The Impact ◽  
Over Time

This study investigates taxi drivers’ multi-day cruising behaviours with GPS data collected in Shenzhen, China. By calculating the inter-daily variability of taxi drivers’ cruising behaviours, the multi-day cruising patterns are investigated. The impacts of learning feature and habitual feature on multi-day cruising behaviours are determined. The results prove that there is variability among taxis’ day-to-day cruising behaviours, and the day-of-week pattern is that taxi drivers tend to cruise a larger area on Friday, and a rather focused area on Monday. The findings also indicate that the impacts of learning feature and habitual feature are more obvious between weekend days than among weekdays. Moreover, learning feature between two sequent weeks is found to be greater than that within one week, while the habitual feature shows recession over time. By revealing taxis' day-to-day cruising pattern and the factors influencing it, the study results provide us with crucial information in predicting taxis' multi-day cruising locations, which can be applied to simulate taxis' multi-day cruising behaviour as well as to determine the traffic volume derived from taxis' cruising behaviour. This can help us in planning of transportation facilities, such as stop stations or parking lots for taxis. Moreover, the findings can be also employed in predicting taxis' adjustments of multi-day cruising locations under the impact of traffic management strategies.

scholarly journals A Hybrid Fuzzy System Dynamics Approach for Risk Analysis of AUV Operations

2020 ◽  
Vol 24 (1) ◽  
pp. 26-39
Author(s):  
Tzu Yang Loh ◽  
Mario P. Brito ◽  
Neil Bose ◽  
Jingjing Xu ◽  
Natalia Nikolova ◽  
...  
Keyword(s):  
Risk Analysis ◽  
System Dynamics ◽  
Fuzzy System ◽  
Autonomous Underwater Vehicles ◽  
Management Strategies ◽  
Operating Experience ◽  
Rapid Expansion ◽  
Risk Management Strategies ◽  
The Impact

The maturing of autonomous technology has fostered a rapid expansion in the use of Autonomous Underwater Vehicles (AUVs). To prevent the loss of AUVs during deployments, existing risk analysis approaches tend to focus on technicalities, historical data and experts’ opinion for probability quantification. However, data may not always be available and the complex interrelationships between risk factors are often neglected due to uncertainties. To overcome these shortfalls, a hybrid fuzzy system dynamics risk analysis (FuSDRA) is proposed. The approach utilises the strengths while overcoming limitations of both system dynamics and fuzzy set theory. Presented as a three-step iterative framework, the approach was applied on a case study to examine the impact of crew operating experience on the risk of AUV loss. Results showed not only that initial experience of the team affects the risk of loss, but any loss of experience in earlier stages of the AUV program have a lesser impact as compared to later stages. A series of risk control policies were recommended based on the results. The case study demonstrated how the FuSDRA approach can be applied to inform human resource and risk management strategies, or broader application within the AUV domain and other complex technological systems.

scholarly journals A Novel Performance Framework and Methodology to Analyze the Impact of 4D Trajectory Based Operations in the Future Air Traffic Management System

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Sergio Ruiz ◽  
Javier Lopez Leones ◽  
Andrea Ranieri
Keyword(s):  
Traffic Management ◽  
Air Traffic Management ◽  
Air Traffic ◽  
Performance Framework ◽  
Performance Requirements ◽  
The Future ◽  
Traffic Management System ◽  
And Performance ◽  
The Impact

The introduction of new Air Traffic Management (ATM) concepts such as Trajectory Based Operations (TBO) may produce a significant impact in all performance areas, that is, safety, capacity, flight efficiency, and others. The performance framework in use today has been tailored to the operational needs of the current ATM system and must evolve to fulfill the new needs and challenges brought by the TBO content. This paper presents a novel performance assessment framework and methodology adapted to the TBO concept. This framework can assess the key performance areas (KPAs) of safety, capacity, and flight efficiency; equity and fairness are also considered in this research, in line with recent ATM trends. A case study is presented to show the applicability of the framework and to illustrate how some of the complex interdependencies among KPAs can be captured with the proposed approach. This case study explores the TBO concept of “strategic 4D trajectory deconfliction,” where the early separation tasks of 4D trajectories at multisector level are assessed. The framework presented in this paper could potentially support the target-setting and performance requirements identification that should be fulfilled in the future ATM system to ensure determined levels of performance.

Analyzing Simulation-Based Active Traffic Management Impact on a Large-Scale Regional Network

2019 ◽  
Vol 2673 (8) ◽  
pp. 638-647
Author(s):  
Minha Lee ◽  
Chenfeng Xiong ◽  
Zheng Zhu ◽  
Weiyi Zhou ◽  
Lei Zhang
Keyword(s):  
Traffic Management ◽  
Large Scale ◽  
Dynamic Traffic Assignment ◽  
Management Strategies ◽  
Ramp Metering ◽  
Vast Number ◽  
Traffic Conditions ◽  
Road Systems ◽  
Traffic Impacts

A vast number of real-time corridor management strategies have been introduced because the dynamics of traffic patterns and increased congestion result in challenging problems on road systems. Although these strategies can offer positive impacts on regional traffic, their evaluation tools are often limited to the scope of one specific corridor. To fill this gap, this study integrates a mesoscopic dynamic traffic assignment simulation model with an existing traffic-responsive ramp metering strategy. This integrated model is suitable for network-wide analysis and large-scale simulation of integrated corridor management strategies. The integrated modeling platform is demonstrated as a practice-ready tool. We present a case study that explores the benefits of metering control under various traffic conditions in a real-world network in Maryland. Both local and network-wide impacts are illustrated in the case study. This is one of the first attempts to simultaneously analyze network-wide traffic impacts and capture minute-by-minute demand–supply interactions under managed corridor strategies. The results indicate that ramp metering is beneficial even under non-recurrent traffic conditions at multiple spatial resolutions.

scholarly journals Perceptions of wheat producers towards risk and risk management strategies: A case study from Turkey

2019 ◽  
Vol 49 (12) ◽  
Author(s):  
Seyit Hayran
Keyword(s):  
Risk Management ◽  
Management Strategies ◽  
Policy Instruments ◽  
Data Set ◽  
Wheat Market ◽  
Risk Management Strategies ◽  
Risk Sources ◽  
The Government ◽  
The Impact

ABSTRACT: In this study, risk perception of wheat producers in Turkey was examined based on a case study conducted in Bitlis Province. The data set used in the study was obtained from 157 farmers randomly. Factor analysis was employed to classify risk sources and management strategies, and then multiple regression was used to investigate the relationship between farmers perceptions and some characteristic. Results of this study have shown that economic-based risks were perceived more strongly by farmers. Farmers’ also used more than one risk management strategy to minimize the impact of the risks they face. So, in order to ensure social and economic sustainability and predictability in wheat production and wheat market, the government should be considered preventive policy instruments and interventions to prevent fluctuations in input and output prices.

scholarly journals Effects of Rain on Freeway Traffic in Southern California

2017 ◽  
Vol 2616 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Sawanpreet Singh Dhaliwal ◽  
Xinkai Wu ◽  
John Thai ◽  
Xudong Jia
Keyword(s):  
Los Angeles ◽  
Traffic Management ◽  
Southern California ◽  
Management Strategies ◽  
Heavy Rain ◽  
Flow Speed ◽  
Free Flow ◽  
Light Rain ◽  
Free Flow Speed ◽  
The Impact

A number of studies in the past quantified the effect of rain on traffic parameters but were limited to wet areas. This research expands the literature by studying the effect of rain in a dry area such as Southern California and considering regional differences in the impact. Traffic data (loop detectors) and precipitation data (rain gauges) from the Los Angeles, California, metropolitan area were analyzed to access the effect of rain on traffic stream parameters such as free-flow speed, speed at capacity, and capacity. Rainfall events were categorized as light, medium, and heavy as discussed in the 2010 Highway Capacity Manual. Density plots and fundamental diagrams for rain types proved that free-flow speed, speed at capacity, and capacity were reduced by 5.7%, 6.91%, and 8.65%, respectively, for light rain; 11.71%, 12.34%, and 17.4%, respectively, for medium rain; and 10.22%, 11.85%, and 15.34%, respectively, for heavy rain. The reductions for free-flow speed were lower, whereas for speed at capacity and for capacity, they were higher than those reported in the 2010 manual. Moreover, headway increased during rain; this finding shows cautious driving behavior. Multiplicative weather adjustment factors were computed to compensate for the loss of speed and capacity. Also demonstrated was the spatial and temporal effect of rain on traffic. Downstream traffic was not much affected by a rainfall event, whereas the upstream traffic was negatively affected. This study is expected to support weather-responsive traffic management strategies for dry areas.

scholarly journals Assessing the Impact of Weather on Traffic Intensity

2010 ◽  
Vol 2 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Mario Cools ◽  
Elke Moons ◽  
Geert Wets
Keyword(s):  
Travel Behavior ◽  
Traffic Management ◽  
Management Strategies ◽  
Weather Conditions ◽  
Traffic Intensity ◽  
Weather Effects ◽  
Specific Location ◽  
Traffic Count ◽  
Local Roads ◽  
The Impact

Abstract This paper focuses on the effect of weather conditions on daily traffic intensities (the number of cars passing a specific segment of a road). The main objective is to examination whether or not weather conditions uniformly alter daily traffic intensities in Belgium, or in other words whether or not road usage on a particular location determines the size of the impacts of various weather conditions. This general examination is a contribution that allows policymakers to assess the appropriateness of countrywide versus local traffic management strategies. In addition, a secondary goal of this paper is to validate findings in international literature within a Belgian context. To achieve these goals, the paper analyzes the effects of weather conditions on both upstream (toward a specific location) and downstream (away from a specific location) traffic intensities at three traffic count locations typified by a different road usage. Perhaps the most interesting results of this study for policymakers are the heterogeneity of the weather effects between different traffic count locations, and the homogeneity of the weather effects on upstream and downstream traffic at specific locations. The results also indicate that snowfall, rainfall, and wind speed diminish traffic intensity, and high temperatures increase traffic intensity. Further generalizations of the findings might be possible by studying weather impacts on local roads and by shifting the focus of research toward travel behavior.

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