Transportation Subsystem Research Articles

Relationships between Interdependency, Reliability, and Vulnerability of Infrastructure Systems: Case Study of Biofuel Infrastructure Development

AbstractInfrastructure systems are becoming increasingly complex and interdependent, for example, the growing biofuel economy in the United States that is creating new interdependencies between agriculture, biorefining, and transportation. Questions arise of the consequences of these new and expanding interdependencies on overall system performance. This paper proposes the differentiation between linear and nonlinear interdependency that, though elementary, is useful for describing the joint behavior of interdependent systems. Linear interdependency is where representative variables of systems of interest change linearly with each other, while nonlinear interdependency is where the variables change with each other but in some other manner. This paper uses Pearson’s correlation coefficient to quantify the linear interdependency between the transportation and biorefining subsystems within a larger biofuel infrastructure system based on Monte Carlo simulation results of a mathematical programming model of th...

Automated Guided Vehicle System for Work-in-Process Movement

The paper presents an automated guided vehicle transportation subsystem used for work-in-process movement, built at the Production Engineering Institute of Cracow University of Technology. It describes design and operational parameters of built vehicles as well as the principles of integration of AGV control subsystem with the AIM multi-agent manufacturing control system. Furthermore, results of the verification of applied path-finding, anti-collision and anti-deadlock algorithms are included.

城市系统碳循环:特征、机理与理论框架

城市是地表受人类活动影响最深刻的区域,城市系统碳循环在全球和区域碳过程中具有重要的地位和作用。提出了城市"自然-社会"二元碳循环的概念,探讨了城市系统碳循环的一般特征;分析了城市系统碳循环的内部机理,主要包括:城市系统碳储量和碳输入/输出通量的主要过程和途径、城市系统碳储量、碳通量和碳流通的生命周期分析、城市系统碳输入和碳输出的类型划分等;提出了基于系统层次划分和碳流通过程的城市系统碳循环的研究框架,分析了城市自然系统和城市经济系统的主要碳流通过程和环节,构建了城市系统碳循环研究的思路和理论框架;最后提出了城市系统碳循环领域未来的研究重点。;Since 1990's, researches on carbon cycle were mostly focused on natural processes, such as farmland ecosystem, forest ecosystem and soil, but the anthropogenic carbon process in urban system was always ignored. Presently, under the pressure of climate change and international carbon emission reduction, how to coordinate the relationship between economic development and urban environmental protection, promote carbon emission reduction and develop low-carbon economy has been a hot multi-disciplinary topic. Urban system is an ecosystem that is profoundly impacted by human activities on the earth, in which land use and land cover changes drastically. With much human energy consumption and carbon emission, urban carbon cycle will inevitably have a profound impact on global carbon cycle and climate change. So, urban carbon cycle plays an important role in regional and global carbon cycle processes. Research on urban carbon cycle is not only the important basis for establishing low-carbon urban strategies, but also the theoretical reference for choosing low-carbon city pattern. Firstly, the concept of natural-social dualistic carbon cycle of urban system was put forward and analyzed, and the circulation process map of urban system was established. It shows that the carbon cycle process of urban system was quite different from that of natural ecosystem. Further, the main characteristics of urban carbon cycle were discussed in this paper. Generally, urban system is a complex system that includes natural and anthropogenic processes, horizontal and vertical processes, surface and underground processes, economic and social processes. Secondly, the mechanism of carbon cycle in urban system was discussed from several aspects, such as: the main processes of carbon storage and carbon input & output fluxes, life cycle of carbon storage, carbon fluxes and carbon circulation processes, carbon input & output types of urban system, etc. In this section, the processes of carbon storage and carbon fluxes of urban system were emphasized in details for better understanding the process of urban carbon cycle. The life cycle analysis of carbon storage, carbon flux and carbon circulation processes gave us a clear idea on how to control the important carbon emission reduction sections. Thirdly, the research framework of carbon cycle in urban system was established according to systematic division and carbon circulation process analysis. Based on the analysis of carbon processes in urban system, the urban system was divided into several social-economic subsystems (such as industrial, commercial, residential, transportation and office subsystems) and natural subsystems (such as water body, farmland, forest, pasture land and urban greenbelt, etc.). Furthermore, the carbon circulation processes between urban system and external system, and the carbon processes between urban natural ecosystems and social-economic systems were analyzed, and the theoretical framework of urban carbon cycle research was established. Finally, the future research trends of urban carbon cycle were put forward, such as: building systematic urban carbon cycle model, establishing urban carbon emission factor database and calculation criterion, promoting contrast studies on carbon cycle and circulation mode of cities under different developing levels, strengthening control and management of key processes in carbon cycle of urban system.

Reliability-centered maintenance methodology for goliath crane of transmission tower

Reliability centered maintenance (RCM) methodology was originally developed by the U.S. commercial airlines industry in the year of 1960 for identifying applicable and effective preventive maintenance tasks. Safety systems are usually stand by systems and they are periodically to reveal and repair failures that may have occurred since the previous activation or inspection.RCM approach has been applied to the goliath crane system of transmission tower industry for research work reported in this paper.RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimization of preventive maintenance cost. In the present study preventive maintenance task suggested for power transmission subsystem, guiding and transportation subsystem, hydraulic subsystem and supply current subsystem in goliath train. Keywords-Goliath crane system, optimization ,rcm, transmission tower

Factors Influencing Effectiveness of Transit Signal Priority and Late-Bus Recovery at Signalized-Intersection Level

Transit priority systems have the potential to improve transit performance and address capacity constraints by giving priority to transit movements over other traffic. This research focused on the effectiveness of conditional transit priority or the manipulation of traffic signal timing plans to reduce delay of late transit buses. The integration of two transportation subsystems—traffic signals and public transit systems—was studied. These subsystems interact along a congested corridor where they share a common roadway infrastructure and transit signal priority (TSP) regulates the interaction between traffic signals, passenger traffic, and buses. Previous research has focused on the evaluation of bus TSP performance at the route level. In practice, it is important to understand not only TSP performance at the route level but also the impact of TSP at the level of the traffic signal intersection (e.g., to allow progression in major cross streets). TSP can significantly improve performance at specific intersections, even though at the route level TSP shows a more modest impact. This study proposed the integration of several data sets such as bus scheduling and location, passenger flows, and TSP requests to evaluate schedule adherence at the stop level and TSP performance at the level of the signalized intersection. A congested arterial corridor was analyzed and regression analysis was used to determine the key factors that affect bus travel time and schedule recovery for late buses. TSP was found to be most effective at lower-volume intersections where queuing was less problematic. Implications of the findings are analyzed and discussed.

A U.S. Energy System Model for Disruption Analysis: Evaluating the Effects of 2005 Hurricanes

We refer to the national infrastructure necessary to provide electric energy in the U.S. as the National Electric Energy System (NEES). It includes the three primary energy production and transportation subsystems: electric, natural gas, and coal. In order to facilitate the study of very large-scale disruptions within the NEES, we have developed a multiperiod network flow model able to simulate the movements of bulk energy flows through the network and represent large-scale disruptions on critical infrastructure. This paper describes the model with focus on special features necessary to analyze large-scale disruptions. In order to validate our approach, we have collected disruption data following the 2005 Gulf-coast Hurricanes Katrina and Rita and then incorporated these data into the model. By comparing the results with and without the hurricanes, the additional operational costs as a result of them are estimated to be $10.5 billion from September to December 2005.

Systemic modeling and logistic planning in the petroleum supply chain

The study of the petroleum supply chain involves several subsystems that interact among themselves in the exploration processes, transportation to the terminals, storage in tanks and transference to the refineries. In this context, this paper aims to study the characteristics of the main subsystems that compose the upstream segment, which ranges from petroleum production in the platforms to the shipment to oil refineries, with special attention to the transportation subsystem. The adopted methodology compatibilizes decisions based on distinct levels of hierarchical planning, initially attempting to identify the main resources dimensioning on a strategic basis and afterwards, programming them on a tactic/operational level. Computational models were developed using ARENA software, version 5.0. CPLEX, version 10.0, was used to develop simulation and optimization models. The optimization model was adopted to rectify or improve the result presented by the simulation model, completing the decision-supporting tool that enables to analyze each scenario and compose the project of the petroleum supply chain.

Integrated Scheme for Olympic Village Traffic and Parking Arrangements

The present study deals with the development of an integrated transportation scheme serving the needs of guests at an Olympic Village during the 2004 Athens Olympics. The Olympic Village was located at the port of Piraeus docks (within the Athens greater area), and was designed to accommodate 13,500 guests. This integrated scheme comprised vehicle and pedestrian traffic arrangements as well as bus and passenger car parking arrangements. Based on the various transport and security needs of the Olympic guests, the related transportation parameters were estimated, leading to the design of the infrastructure and operation provisions of the various transportation subsystems, including secured areas, and control entrance and exit gates. The final implementation of the proposed integrated scheme together with the special transportation management measures resulted in a high level of service offered to the Olympic guests during the Athens 2004 Olympics, a successful case to be used as an example in other similar cases.

Accessibility of a Destination-Based Transportation System: A Large Airport Study

The accessibility of a destination-based transportation system is defined to quantify the performance of transportation systems which access a distinct destination. The access cost is used to reflect the utility of the transportation system including the fatigue and inconvenience in the total cost. The cost is quantified by two coefficients which represent the different characteristics of various people. The average cost and the income-relative accessibility are used to describe various aspects of the accessibility and to evaluate the accessibility of a destination-based system. A case study uses data from the Kunming transportation system to evaluate the accessibility of the present city airport. The calibrated coefficients are then used to evaluate the transportation system to the new Kunming international airport. The results show that this transportation accessibility evaluation can be combined with transportation planning to study transportation sub-systems.

Performance evaluation of a multi-echelon production, transportation and distribution system: A matrix analytical approach

This study proposes an originative method to evaluate complex supply chains. A tentative multi-echelon production, transportation and distribution system with stochastic factors built-in is employed as a test bed for the proposed method. The supply subsystem formulated in this study is a two-stage production facility with constant probability of feedback and stochastic breakdowns. The transportation subsystem is a service facility with one server. The distribution subsystem under study is a single central warehouse with M retailers. All the participants of the supply chain use base-stock policies and single-server settings. We investigated both the make-to-order (MTO) and make-to-stock (MTS) policies for different base-stock levels, as adopted at different sites. Applying quasi-birth-and-death (QBD) processes as decomposed building blocks and then using the existing matrix analytical computing approach for the performance evaluation of a tandem queue constitutes the main procedure of this study. We also discuss the possibilities of extending the current model to account for other inventory control policies as well as for multi-server case. Numerical study shows our proposed analytical model is robust for practical use.

Praktek Indonesia dalam Pemanfaatan Wilayah Udara

Air transportation is a global transportation, vehicles, terminals, and airways are main components of the air transportation sub-system. Vehicles, in this matter aircraft as a tool of transportation, have a global characteristic because of the high speed and wide range capability compare to vehicles of any other transportation mode. An airway is a flight lane in air space. Every aircraft, which pass the airways, has the right of air traffic services. The authority provision of giving the air traffic services internationally is provided in Annex 11 to the Convention on Civil Aviation about Air Traffic Services. The authority mentioned above includes responsibility to provide air traffic services in air space above the territory, which the state has its jurisdiction and responsibility to the aerodrome where the air traffic services are given. A state, through an agreement, may delegate the responsibility of providing air traffic services to the other states or accept responsibility mentioned above from the other states. Air space above the high seas or air space above the area that is not under any sovereignty of certain states which is the air traffic services are needed is determined in a regional air navigation agreement. Usually, Regional Air Navigation Meeting is a forum to accomplish this purpose.

Multi-attribute responsive dispatching strategies for automated guided vehicles

This paper discusses responsiveness in automated guided vehicle dispatching. The additive multi-attribute dispatching rule employs two attributes, output buffer length and travel time to pick-up, to prioritize the tasks based on the current system status, while the weights convey information about the relative criticality of the processing and transportation sub-systems. The main responsiveness of the system is inherent in the manner these weights are determined. Two approaches are proposed for this purpose: parametric approach where the weights are calculated at the beginning of each planning horizon based on expected system characteristics; and dynamic approach where the system is allowed to update the weights throughout evolution utilizing some system statistics. Simulation experiments under various scenarios evaluate the performances of the proposed dispatching strategies based on facility throughput.

Maintenance strategy for tilting table of rolling mill based on reliability considerations

Abstract Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in tilting tables are 14 scheduled on-condition tasks, 10 scheduled on-restoration tasks, seven scheduled discard task. Whereas for 14 failure modes no scheduled maintenance has been proposed. Existing maintenance schedule for tilting tables indicates the maintenance action as and when required. Hence RCM based schedule specifies that additional preventive maintenance tasks need to be executed as compared to none initially. Cost incurred for this can be offset from the savings accrued from reduction in loss of production due to repetitive breakdowns. The methodology of RCM adopted in western industries cannot be applied as it is to Indian industries because of labour oriented nature, partially computerised information systems, non-availability of the information about cost of loss of production due to breakdown and age-reliability pattern of equipment, insufficient maintenance database. These problems can be overcome by development of sound MMIS, formulation of RCM review group and imparting suitable training to acquire the relevant skills in RCM. Thus RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimisation of preventive maintenance cost. This can further boost up the prospects of Indian industry to offer the products at globally competitive prices.

REAL CAPACITY OF ROPEWAY TRANSPORTATION SUBSYSTEM

The ropeway transportation subsystem plays a major role inmountain resort systems. It is characterised by an exceptionalinle1weavement of interactions of single system elements. In orderto provide sustainable development of the entire mountainres on systems, the real capacity of the ropeway transp01tationsystem was set. Real capacity of the ropeway transp01tation systemis one of the indicators of the development harmonisationlevel of single system elements. The research into this field wasdone at Road and Traffic Centre of Faculty of Civil Engineering,University of Maribor.The atticle deals with basic points, with method and the resultsof research. It also represents some experiences ofknow-how transfer into the Slovene environment.

Control of Flexible Manufacturing System: Interaction Between Production and Transportation

Several approaches are presented for the control of a flexible Manufacturing System. The method of study is to first break the FMS down into transportation and production sub-systems. Each sub-system is presented by using the Intelligent Decision Center (IDC) concept, then the interactions between the IDCs are shown in order to establish the different control approaches of the FMS.

Microprocessors in factory automation — A case study of an automated guided vehicle system and its integration into a hierarchical control structure

Automated guided vehicle systems (AGVS) are one of the key elements in flexible manufacturing systems. A brief survey of control techniques of AGVS's is given. The control and guidance mechanisms of the multiTrans AGVS are described in detail, and special attention is paid to the features which increase flexibility in the case of changes to the path layout. The integration of a transportation system like an AGVS into the overall control structure of a computer aided manufacturing system is a crucial point: the functionality of all involved subsystems of a manufacturing system has to be agreed upon in order to get an open system with minimum adaptation effort when integrating or replacing subsystems. A concept for the integration of the various control systems into a uniform structure is presented, with special emphasis on transportation subsystems. Finally, experiences, problems and consequences of the implementation of the multiTrans control system are reported.

Simulation Tools for Investigation and Design of FMS Transportation Systems

The software developed for simulation and optimization of the FMS transportation systems is described. It allows solving three interrelated problems: (1) choice and arrangement of equipment in the FMS workstation; (2) simulation and evaluation of the FMS transportation subsystem operation; and (3) development of efficient algorithms for constructing the AGV route. The appropriate mathematical models and the numerical experiment results are presented. The software developed is an integral part of a programming complex to allow the computer-aided design and synthesis of the control modes for the FMS subsystems.

A Method To Estimate the Pollution Risk and Cost of OCS Oil Transportation

Energy developers are concerned with the potential added development expenses resulting from environmental restrictions in transporting Outer Continental Shelf oil. This paper presents a method for combining the available cost and spill risk data into a format that can be used for rational decision-making. Introduction Since the Arab oil embargo, considerable attention has been focused on our Outer Continental Shelf (OCS) lease sales. The Dept. of the Interior's Bureau of Land Management and the several affected states have spent a great deal of time and effort on assessing the environmental impact associated with developing the oil and gas lease areas. An area that has not been treated extensively in an analytical fashion is the transportation component of the over-all system. No objective and thorough comparison has been made of the economic and environmental merits and risks of these alternatives. This paper presents the method used during a study of four hypothetical production sites in the Gulf of Alaska, as shown in Fig. 1. In addition, the results of one site analysis are presented relative to the environmental and economic trade-offs that must be considered by those involved with OCS planning and development. Description of the Scenario Site 3 in the Gulf of Alaska is used in this paper to demonstrate the approach used to evaluate the options available for transporting the energy products produced offshore. Site 3 is about 13 miles offshore in water 95 fathoms deep. Reserve estimates for the lease area are highly uncertain, so a range of reserves from 25 million to 2 billion bbl of oil recoverable over 20 years was investigated. It is not contemplated that oil produced in the Gulf of Alaska will be refined or consumed in Alaska or adjoining parts of Canada, nor is it anticipated that the oil will parts of Canada, nor is it anticipated that the oil will be moved to refining or consuming areas over land. This implies that Gulf of Alaska oil will be transported by tanker over sea routes to locations as distant as the U.S. West Coast. However, the use of tankers entails a requirement for substantial offshore storage capability that is not necessary if pipelines are used for transfer to shore, because production continues while the tanker is in transit. Thus, costs and spill risks associated with offshore storage must be considered when evaluating tanker alternatives, and such storage facilities effectively become part of the tanker transportation subsystem. Hence, integrated transportation and storage systems were designed for each hypothetical production site. Three general concepts of transportation and storage systems were utilized: tanker transshipment, pipeline transshipment, and direct shipment. Each of these concepts is outlined below.Tanker transshipment. Offshore oil is stored temporarily at the production site, where it is picked up by a small shuttle taken This tanker carries the picked up by a small shuttle taken This tanker carries the oil to a port facility near the Gulf, and offloads to shore storage. Next, the oil is loaded aboard a 90,000-DWT tanker for shipment to the U.S. West Coast.Pipeline transshipment. A pipeline links the production site to a shore port facility. Oil is production site to a shore port facility. Oil is produced offshore and pumped through the pipeline to onshore produced offshore and pumped through the pipeline to onshore storage at the port. It is then transported to the U.S. West Coast by a 90,000-DWT tanker. JPT P. 639

An electronic route-guidance system for highway vehicles

The electronic route-guidance system (ERGS) is the result of an effort by the Office of Research and Development, Bureau of Public Roads, to develop a new concept for guiding the motorist. To implement the concept, a system has been developed which makes use of electronic equipment both in the participating vehicles, and at intersections which are to supply guidance instructions. The system is destination oriented. The driver enters a code word, representing his intended destination, into the vehicle equipment. Then as the vehicle approaches each instrumented intersection, the destination code is transmitted to the roadside where it is decoded, according to a stored program, and a routing instruction is transmitted back to the vehicle. In the vehicle, the routing instruction is displayed to the driver in the form of a symbol or word message, which gives the maneuver the driver should make at the upcoming intersection or interchange to reach his destination optimally. The development of the system from its conception to its future application and benefits are discussed. The descriptions of today's highway routing problems in the "static" and "dynamic" situations are presented, then the outline of the Bureau of Public Road's developmental effort and the major contributions of its various contractors is discussed; Philco-Ford's development of a destination coding system and techniques for solving optimal routings, General Motors Corporation's development of an installed and operating engineering model, Serendipity's determination of driver-information requirements for ERGS, and Kollsman Instrument Corporation's development of an automobile head-up display for the ERGS routing symbols. A separate section gives a description of the General Motors system design at the functional and component level. Future development and system benefits are discussed. Dynamic system requirements over and above the present or static ERGS are envisioned, including both additional hardware and software. Benefits to the highway system and to the highway user are given for the static or preprogrammed system and for the dynamic system. A highway transportation subsystem which could be implemented in the near future, and which retains the driver as an integral part of the system, but is expected to enhance the driver's performance by unburdening his route guidance task and allowing more attention to the primary task of controlling the vehicle, is presented. Furthermore, the addition of central control facilities and communications links to intersections is expected to permit more uniform distribution of traffic over the highway network.