Analysis Of Transport Systems Research Articles

A Nonparametric Efficiency Analysis of Shanghai Public Transport Systems

We present a nonparametric comparative efficiency analysis of urban public transport systems (UPTS) in Shanghai (2004-2012). The UPTS include urban public bus transit system (UPBTS) and urban public rail transit system (UPRTS). We apply data envelopment analysis (DEA) to assess the technical, pure technical and scale efficiencies of UPBTS and UPRTS over years. We find the performance of UPBTS and UPRTS are good in general but still have a potential scope for improvement. We also quantitatively analyze the reasons for inefficiency of them in some years and provide potential improvements for inefficient units. Moreover, we observe the efficiency of UPBTS is better despite a good development trend in the efficiency of the UPRTS. We demonstrate the UPRTS during the period 2006-2011 works on decreasing returns to scale (DRS), which indicates the authorities should adjust the UPRTS structure and improve the operational services without blindly expanding the levels of inputs. Our work may help in evaluating the possible enhancement of the operations of the UPTS.

Application of Discrete Mathematics in Urban Transportation System Analysis

1 School of Automotive Engineering, Dalian University of Technology, Dalian 116024, China 2 Transportation Management College, Dalian Maritime University, Dalian 116024, China 3Department of Mechanical and Manufacturing Engineering, Aalborg University, Denmark 4 Faculty of Technology, Policy and Management, Delft University of Technology, Delft, The Netherlands 5 College of Transportation, Jilin University, Changchun 30022, China

Comprehensive analysis of pipeline transportation systems for CO2 sequestration. Thermodynamics and safety problems

The aim of this paper is to analyze CO2 compression and transportation processes with safety issues for post-combustion CO2 capture applications for basic technological concepts of a 900MW pulverized coal-fired power plant. Four various types of compressors including a conventional multistage centrifugal compressor, an integrally geared centrifugal compressor, a supersonic shock wave compressor, and pump machines were used. This study emphasizes that total compression power is a strong function of the thermodynamic process and is not only determined by the compressor efficiency. The compressor increases the CO2 pressure from normal pressure to critical pressure and the boosting pump continues to increase the pressure to the required pressure for the pipeline inlet. Another problem analyzed in this study is the transport of CO2 by pipeline from the compressor outlet site to the disposal site under heat transfer conditions. Simulations were made to determine maximum safe pipeline distance to subsequent booster stations depending on inlet pressure, environmental temperature, the thermal insulation thickness and the ground level heat transfer conditions. From the point of view of environmental protection, the most important problem is to identify the hazards which indirectly affect CO2 transportation in a strict and reliable manner. This identification is essential for effective hazard management. A failure of pipelines is usually caused by corrosion, material defects, ground movement or third party interference. After the rupture of the pipeline transporting liquid CO2, a large pressure drop will occur. The pressure will continue to fall until the liquid becomes a mixture of saturated vapour/liquid. In the vicinity of the rupture, liquid CO2 will escape and immediately vaporize and expand. In the paper the discharge and atmospheric dispersion of CO2 are discussed.

Mining bicycle sharing data for generating insights into sustainable transport systems

Bicycle sharing systems (bike-shares) are becoming increasingly popular in towns and cities around the world. They are viewed as a cheap, efficient, and healthy means of navigating dense urban environments. This paper is the first to take a global view of bike-sharing characteristics by analysing data from 38 systems located in Europe, the Middle East, Asia, Australasia and the Americas. To achieve this, an extensive database depicting the geographical location and bicycle occupancy of each docking station within a particular system has been created over a number of years to chart the usage in the chosen systems (and others) and provide a consistent basis on which to compare and classify them. Analysis of the variation of occupancy rates over time, and comparison across the system’s extent, infers the likely demographics and intentions of user groups. A classification of bike-shares, based on the geographical footprint and diurnal, day-of-week and spatial variations in occupancy rates, is proposed. The knowledge of such patterns and characteristics identifiable from the dataset has a range of applications, including informing operators and policymakers about the maintenance of a suitable balance of bicycles throughout the system area (a nontrivial problem for many bike-shares), the location of new docking stations and cycle lanes, and better targeting of promotional materials to encourage new users. Within the context of transport research, the systems utilised here are part of relatively small, closed environments that can be more easily modelled and validated. Such work lays foundations for the analysis of larger scale transport systems by creating a classification of the different systems and seeks to demonstrate that bike-shares have a lot to offer both as an effective method of transport and a rich source of data.

Penilaian Sistem Transportasi yang Mengarah Pada Green Transportasi di Kota Surakarta

Pemerintah Kota Surakarta telah merancang sistem transportasinya menuju green transportationsebagai bagian dari konsep eco city yang dikembangkan untuk kota ini sejak 2010. Penelitian inimelakukan penilaian terhadap sistem transportasi di Kota Surakarta dalam upayanya untukmewujudkan transportasi yang berkelanjutan di kota tersebut. Studi ini menggunakan pendekatankuantitatif melalui 3 analisis, meliputi: (1) analisis sistem transportasi terkait sistem aktivitas, sistempergerakan dan sistem jaringan, (2) analisis transportasi berkelanjutan terkait aspek ekonomitransportasi, sosial transportasi dan dampak lingkungan transportasi, serta (3) analisis greentransportation terkait kebijakan, pemilihan moda dan penerapan konsep. Analisis penilaian sistemmenunjukkan bahwa penerapan konsep green transportation yang diterapkan untuk mewujudkantransportasi berkelanjutan sudah ‘cukup berhasil’. Analisis transportasi berkelanjutan menunjukkanbahwa penerapan konsep sudah ‘cukup baik’ dan representatif menuju green transportation. Namundemikian, perwujudan green transportasi belum bisa dikatakan ‘baik’ karena masih banyaknyakekurangan di berbagai aspek. Studi ini menemukan kebutuhan akan suatu dokumen resmi yangmenjelaskan, mengarahkan, dan mengatur penerapan konsep Green Transportasi di Kota Surakarta.Kata kunci: green transportation, transportasi berkelanjutan

Analysis and Design of Wire Transport System in Microwire-Electronic Discharge Machining

A dynamic model for analyzing the wire transport system of micro w-EDM (wire electronic discharge machining) is proposed. Based on the model, two mechanisms are proposed to stabilize the wire tension. The first mechanism is the active wire feed apparatus where the wire spool is fed by a motor actively, instead of passively pulled by the windup motor. Hence, the inertia loading of the wire spool can be isolated from the system. The second mechanism is mounting a multilayer damped vibration absorber (MDVA) on the system. As the wire tension variation occurs, the MDVA oscillates to attenuate the wire tension variation. The performances of both mechanisms on the wire tension variation are theoretically investigated and experimentally validated through corner cutting on the 1.0 mm thickness tungsten carbide. Results show that the wire tension variation can be reduced from 10.3 gf to 3.3 gf after mounting the active wire feed apparatus and the oscillation frequency is increased from 13 Hz to 21 Hz. The wire tension variation can be further reduced to 1.9 gf after mounting the MDVA on the system and the high frequency perturbation is significantly attenuated. The 30-deg corner cutting shows that the corner error are significantly reduced from 26.0 μm to 12.0 μm; the standard deviation of kerf is reduced from 4.34 μm to 0.96 μm, and the surface roughness Ra is reduced from 1.15 μm to 0.63 μm after employing both developed mechanisms.

Optimization and GIS-Based Intelligent Decision Support System for Urban Transportation Systems Analysis

Optimization and GIS-Based Intelligent Decision Support System for Urban Transportation Systems Analysis

Atlanta: a mega logistics center in the Piedmont Atlantic Megaregion (PAM)

This paper looks at spatial patterns of freight and logistics activities and the planning and policy issues associated with them. Two important characteristics of the geography of the logistics industry are analyzed: (1) “Logistics sprawl,” i.e. the spatial deconcentration of logistics facilities and distribution centers in metropolitan areas, and (2) the polarization of logistics activities, i.e. the concentration of logistics activities in very large metropolitan areas. The paper focuses on Atlanta, one of the largest metropolitan areas in the United States (US). Like other very large cities in the US, in recent years logistics activities have increased considerably in Atlanta. The paper also examines the Piedmont Atlantic Megaregion (PAM), which has a total population of 15 million and includes Birmingham, Atlanta, Raleigh–Durham and Charlotte. PAM contains many distribution centers with a national and international market area, and is one of the country’s fastest growing locations for logistics hubs. The megaregion concept is particularly well-suited to the analysis of freight transport systems, because freight transport’s market areas, driven by global supply chains, are largely disconnected from a single city and spatially organized on a regional and multicity basis. Another focus of the paper is the question of planning for a more efficient locational pattern of freight facilities across metropolitan areas and within megaregions. Local governments compete for jobs and activities that generate tax revenues, and logistics has become a significant activity for many US metropolitan areas. The megaregion concept can contribute to a more collaborative regional planning approach.

Estimation of a disaggregate multimodal public transport Origin–Destination matrix from passive smartcard data from Santiago, Chile

A high-quality Origin–Destination (OD) matrix is a fundamental prerequisite for any serious transport system analysis. However, it is not always easy to obtain it because OD surveys are expensive and difficult to implement. This is particularly relevant in large cities with congested networks, where detailed zonification and time disaggregation require large sample sizes and complicated survey methods. Therefore, the incorporation of information technology in some public transport systems around the world is an excellent opportunity for passive data collection. In this paper, we present a methodology for estimating a public transport OD matrix from smartcard and GPS data for Santiago, Chile. The proposed method is applied to two 1-week datasets obtained for different time periods. From the data available, we obtain detailed information about the time and position of boarding public transportation and generate an estimation of time and position of alighting for over 80% of the boarding transactions. The results are available at any desired time–space disaggregation. After some post-processing and after incorporating expansion factors to account for unobserved trips, we build public transport OD matrices.

Review and Systematization of Efficiency Measurement Methods Used in the Transport Sector

Efficiency analysis of transport systems can be carried out using numerous different techniques. Experts generally distinguish them as parametric and non-parametric methods, or else as methods using a production function, an index or not using anything of this kind. Based on the literature and on own research the present paper sets up a clear systematization of these techniques giving a brief summary of their essence while also providing examples of their application in the transport sector. Having elucidated each method, the author also outlines the correlation and the reliability of the techniques and presents a novel view which stresses the importance of links between the different techniques. KEY WORDS: efficiency measurement, transport, TFP, MPI, SFA, DEA, OCRA

Time-Variant Travel Time Distributions and Reliability Metrics and Their Utility in Reliability Assessments

Several metrics of reliability have been recommended for use. These metrics may need to be calculated at relatively fine levels of aggregation of travel time data when used for advanced management strategies and transportation system modeling and analysis. This study investigates the variation of travel time distributions by time of day at fine temporal aggregation levels, the sensitivity of various reliability metrics to these variations, the effect of the aggregation level choices on the calculated metrics, and the amount of data required to estimate stable values of the reliability metrics. The investigation is made for a facility that has general purpose lanes and high-occupancy-toll lanes. The results show that the parameters of travel time distributions vary during the peak period, reflecting the effects of traffic congestion, traffic flow dynamics, and how much nonrecurrent factors, such as incidents, contribute to the unreliability of travel time on the investigated facility. Trends of variations are observed when reliability metrics are used to assess reliability as the congestion level changes during the peak period. The results also show that examining combinations of time-variant static distribution parameters and reliability metrics of the general purpose and high-occupancy-toll lanes can provide valuable information that cannot be obtained when the analysis is performed at higher aggregation levels. The study results suggest using at least one year of data to obtain stable values of reliability metrics.

Shared passengers and goods urban transport solutions

Urban goods transport, long considered not to be a priority issue, seems to be attracting interest today not only by traditional actors, such as local administrations and logistics firms, but also by new actors, such as local public sector transport companies. The first part defines the concept of shared passenger and goods urban transport and describes the existing solutions by means of an international survey. An analysis is then made of the experiences of pioneering European urban transport operators and finally economic factors are examined along with the conditions which could make those solutions an interesting alternative to the traditional provision of logistics services. Finally, possible scenarios for Milan are proposed, based on an analysis of the urban transport system of this regional capital.

Modeling and optimization of transportation systems

I am pleased to write a short editorial for this special issue, which highlights several areas of strength of the Journal of Advanced Transportation such as public transport and airport systems, transportation planning, techniques of transport systems analysis, and multiobjective optimization of transport systems. The emerging area of evacuation planning is also represented. The issue coincidentally highlights the truly global nature of our authors, as well as the interest that we have in attracting outstanding senior as well as emerging authors. A sister special issue on transport and traffic networks will be edited by Co-Editor-in-Chief William Lam. The papers that have been selected for this special issue are “On the allocation of new lines in a competitive transit network with uncertain demand and scale economies” by Zhi-Chun Li, William H. K. Lam, and S. C. Wong; “Simulation-based analysis of personal rapid transit systems: service and energy performance assessment of the Masdar City PRT Case” by Katharina Mueller and Sgouris P. Sgouridis; “Model of personal attitudes towards transit service quality” by Khandker M. Nurul Habib, Lina Kattan, and Md. Tazul Islam; “IF-EM: an interval-parameter fuzzy linear programming model for environment-oriented evacuation planning under uncertainty” by Qian Tan, Guo H. Huang, Chaozhong Wu, and Yanpeng Cai; “Airport gate reassignments considering deterministic and stochastic flight departure/arrival times” by Shangyao Yan, Ching-Hui Tang, and Yu-Zhou Hou; and “Multiple objective optimization of the fleet sizing problem for road freight transportation” by Jacek Żak, Adam Redmer, and Piotr Sawicki. Li et al. consider an innovative model for allocating new transit lines in a competitive network with demand uncertainty and scale economies. They explicitly consider interactions among the transit authority, transit operators, and transit passengers. Mueller and Sgouridis consider a zero-emission model city that is implementing a personal rapid transit system. The PRT will run throughout the city on an underground network. A discrete-event simulation model that supports the design and implementation of the system is described. Habib et al. present an investigation of the reasons for the use of transit in Calgary, Canada. The reasons are expressed as functions of people's perceptions and attitudes towards transit service quality. A multinomial logit model is developed to capture unobservable latent variables useful in defining passenger perceptions and attitudes. Tan et al. consider uncertainty related to factors involved in evacuation activities. The paper employs inexact optimization techniques to address the uncertainties. An interval-parameter fuzzy model is developed for evacuation management under uncertainty. Yan et al. develop an airport gate reassignment model that considers both deterministic (near future) and stochastic (later) flight departure/arrival times. An integer programming technique is applied to formulate a gate reassignment model (GRM). Because gate reassignment needs to be done repeatedly, the GRM is applied within a dynamic gate reassignment framework. Żak et al. consider a fleet sizing problem in a road freight transportation company with a heterogeneous fleet as well as technical back-up facilities. The decision problem is formulated in terms of multiple objective mathematical programming based on queuing theory. Various technical and economic criteria and stakeholder interests are taken into account.

On safety analysis of complex technical maritime transportation systems

The methodology of a multistate approach to complex technical system safety analysis is introduced, and a system safety function is defined. A semi-Markov process for system operation process modelling is used. Furthermore, linking of the multistate system safety model and the system operation process model is carried out to build a general joint safety model of a system operating at variable conditions. This joint model is applied in safety evaluation of the technical system of a ferry operating at sea. The ferry technical system safety is analysed in varying operational conditions, with its safety structure and component safety functions changing in its operational time.

Automating the Process of Terminal Area Node-Link Model Generation

Currently, few detailed airport surface models for air transportation system simulation and analysis exist, because the models are complex to develop and maintain. An improved method of generating detailed models is needed to expand the set of detailed airport surface and terminal airspace models. In this paper, an efficient means to automate the procedures to develop airport surface node-link graph models is proposed. Node-link graphs were created by connecting the centroids of the polygons from geographic information system data. A principal axis-based algorithm was formulated to identify and divide complex polygons. The graph was further improved by adjusting node positions, using the known centerlines from rectangular polygons and removing redundant nodes and links. The procedures were tested on 79 United States airports and proved to be robust, accurate, and efficient.

The analysis of magnesium transport system from external solution to xylem in rice root

We report the characterization of magnesium (Mg) transport from external solution to xylem by using xylem fluid analysis in rice (Oryza sativa L. Nipponbare). It was indicated that Mg uptake and/or xylem loading was mediated by two transport systems, a saturable and a linear component. The K m value of the saturable component was approximately 20 µM, and the saturated concentration was calculated to be 1.5 mM. Using a multi-compartment transport box with excised roots, the transfer from external solution to xylem was shown to be inhibited by hexaamminecobalt(III) {[Co(III)(NH3)6], Co-Hex}, a selective inhibitor of CorA-mediated influx of Mg2+, suggesting that the MRS2/MGT genes that belong to the superfamily of CorA-type membrane proteins are involved in the Mg transport system.

Aldosterone Paradox: Differential Regulation of Ion Transport in Distal Nephron

The mechanisms through which aldosterone promotes apparently opposite effects like salt reabsorption and K(+) secretion remain poorly understood. The identification, localization, and physiological analysis of ion transport systems in distal nephron have revealed an intricate network of interactions between several players, revealing the complex mechanism behind the aldosterone paradox. We review the mechanisms involved in differential regulation of ion transport that allow the fine tuning of salt and K(+) balance.

Solving iTOUGH2 simulation and optimization problems using the PEST protocol

The PEST protocol has been implemented into the iTOUGH2 code, allowing the user to link any simulation program (with ASCII-based inputs and outputs) to iTOUGH2’s sensitivity analysis, inverse modeling, and uncertainty quantification capabilities. These application models can be pre- or post-processors of the TOUGH2 non-isothermal multiphase flow and transport simulator, or programs that are unrelated to the TOUGH suite of codes. PEST-style template and instruction files are used, respectively, to pass input parameters updated by the iTOUGH2 optimization routines to the model, and to retrieve the model-calculated values that correspond to observable variables. We summarize the iTOUGH2 capabilities and demonstrate the flexibility added by the PEST protocol for the solution of a variety of simulation–optimization problems. In particular, the combination of loosely coupled and tightly integrated simulation and optimization routines provides both the flexibility and control needed to solve challenging inversion problems for the analysis of multiphase subsurface flow and transport systems.

Spatial Panel Econometric Analysis of Economic Impacts of Bypasses

This study took a regional approach to the economic impacts of bypasses. The study considered not only how the bypassed communities were affected but also how areas surrounding these communities were affected and whether these impacts differed. Zip code–level data were collected for three states in the Midwest: Illinois, Indiana, and Ohio. This area contained more than 60 bypasses of variably sized communities. The study focused on the manufacturing sector, which made up a major portion of the economy in this region. With a synthesis of economic theory and transportation systems analysis, spatial panel econometric models were estimated to determine whether these communities were significantly affected with respect to employment, establishment, and payroll levels. The findings of this study provided insight into the magnitude of the impacts of bypasses as well as how these impacts varied over space.

Sustainability Analysis of Innovative Transport System

Sustainability Analysis of Innovative Transport System The focus of the research is to develop a new approach to transport solution based on the use of a conveyortype system and to compare the environmental impact of the new system with the existing ones. The new transport system consists of a conveyor driven by an electric motor, with a wind power plant supplying electricity, hydrogen storage and a fuel cell for matching the wind power production with the motor load. The research tasks included the evaluation of the consumption of fossil fuels and the associated environmental impact of existing transport system and a comparison with energy consumption and associated environmental impact of the new system. The energy balance of the conveyor transport system was modelled on an hourly basis by using the EnergyPLAN computer program [1] which allows to analyze a combination of intermittent renewable energy technologies, storage and transport systems. The results show that the existing transport system has greater impact on the environment than the proposed one.