A STOWAGE PLANNING MODEL FOR MULTIPORT CONTAINER TRANSPORTATION

The ship turnaround time at container terminals is an important measure of a port's efficiency and attractiveness. The speed and quality of load planning affect the length of turnaround time considerably. Container operations are extremely important from an economic standpoint, making them a prime target for productivity improvements. In addition, load planning is a very complex problem, since the planners have to account for the stability of the ship and rely on a variety of other stochastic processes. Unfortunately, the load-planning problem is NP-hard making it difficult to obtain an optimal solution in polynomial time. Heuristics that trade quality for tractability are therefore promising tools when coping with this problem. Efficient load planning is accomplished by formulating the stowage-planning model to minimize extra shifting as a mixed integer-programming problem. The key contributions of this dissertation are as follows. A mathematical model is developed which considers real life constraints and considering loading/unloading along the entire voyage. A second mathematical model is formulated to obtain a lower bound on the value of the objective function of the exact solution. A heuristic procedure is developed that is guide by practical considerations that account for the structure of the stowage-planning problem. All proposed mathematical models and heuristic are validated with experimental results. In all cases, these results demonstrate the stability, flexibility and efficiency of the model, and establish its potential as a versatile and practical method for large scale container loading

Formal development and evaluation of narrow passageway system operations

This study applies a new intelligent transportation methodology for transforming informal operations concepts for narrow passageway systems into system-level designs, which will formal enough to support automated validation of anticipated component- and system-level behaviours. Models and specifications of behaviour are formally designed as labelled transition systems. Each object is the management system is assumed to have behaviour that can be defined by a finite state machine; thus, the waterway management system architecture is modelled as a network of communicating finite state machines. Architecture-level behaviours are validated using the Labelled Transition System Analyzer (LTSA). We exercise the methodology by working step by step through the synthesis and validation of a high-level behaviour model for a vessel passing through a waterway network (i.e., canal)

Synthesis and Validation of High-Level Behavior Models for Narrow Waterway Management Systems

This report formulates a new methodology for the incremental transformation of informal operations concepts for a waterway management system into system-level designs, the latter being formal enough to support automated validation of anticipated component- and system-level behaviors. Scenario specifications and models of behavior are formally modeled as labeled transition systems (LTSs). Each object is the management system is assumed to have behavior that can be defined by a finite state machine; thus, the waterway management system architecture is modeled as a network of communicating finite state machines. Architecture-level behaviors are validated using the Labeled Transition System Analyzer (LTSA). We exercise the methodology by working step by step through the synthesis and validation of a high-level behavior model for a ship passing through a waterway network

Hierarchal object-oriented models for management of narrow passageways

Narrow passageways are a significant source of traffic congestion and delay in transportation networks. With traffic volumes expected to increase significantly in the foreseeable future, the effective management of these passageways is needed to mitigate the undesirable impact of these bottlenecks on transportation system safety, performance and cost. In an effort to address the significant challenges associated with the analysis, design, and implementation of appropriate management operations for narrow passageways, an object-based model for the management of narrow passageways in the transportation network is developed. The object model is developed in two steps. The first step identifies high-level management functionality, objects, and associated data/information sources that are common to all narrow passageway applications. In the second step, functionality of the object model is customized to the specific needs of the narrow passageway application domain (e.g., waterways and work zones).peer-reviewe

Traffic Simulation Modeling for an Urban Chemical Disaster: Emergency Evacuation Development and Case Study

ABSTRACT In the post 9/11 era, emergency evacuation in large metropolitan areas has become a subject of national attention. The purpose of this paper was to simulate an emergency response to evacuation procedure in the downtown Baltimore, Maryland area. Proposed traffic modeling for simulating the response to emergency evacuation procedure in the case of a chemical disaster was designed to determine the most efficient response procedure. Using an integrated M&S framework, this paper seeks to describe the design of the Urban Chemical Disaster simulation. Included are the engineering considerations that led to the simulation flow structure using real-time and faster than real-time components. Components of chemical dispersion, chemical concentrations and wind transport media, chemical release rates, and sensing command/control simulations, are contributing factors to traffic flow manipulation. These manipulations will provide an effective emergency evacuation response method which could be used in the near future. A number of methodologies were posited by the research group to learn which could effectively mitigate a potential bioterrorist attack. Lessons learned in the collaboration along with feasible alternatives are discussed in further detail

Developing Guidelines for Implementing Transit Signal Priority and Freight Signal Priority Using Simulation Modeling and a Decision Tree Algorithm

Transit signal priority (TSP) and freight signal priority (FSP) allow transportation agencies to prioritize signal service allocations considering the priority of vehicles and, potentially, decrease the impact signal control has on them. However, there have been no studies to develop guidelines for implementing signal control considering both TSP and FSP. This paper reports on a study conducted to provide such guidelines that employed a literature review, a simulation study, and a decision tree algorithm based on the simulation results. The guideline developed provides recommendations in accordance with the signal timing slack time, the proportion of major to minor street hourly volume, hourly truck volume per lane for the major street, hourly truck volume per lane for the minor street, the proportion of major to minor street hourly truck volume, the proportion of major to minor street hourly bus volume, the volume-to-capacity ratio for the major street, and the volume-to-capacity ratio for the minor street. The guideline developed was validated by implementing it for a case study facility. The validation result showed that the guideline works correctly for both high and low traffic demand

An Emergency Evacuation Planning Model for Special Needs Populations Using Public Transit Systems

The need to have evacuation plans in place for ready implementation for special needs populations became evident after catastrophic events such as Hurricane Katrina. For the purpose of this study, special needs populations will include, but are not limited to, people with physical disabilities, older adults, non-English-speaking populations, residents and employees without vehicles, and tourists. The main objective of this study was to evaluate different evacuation procedures for special needs populations from large urban areas using current public transit systems. A microscopic simulation model was constructed to analyze real-life scenarios for evacuation methodologies. A linear programming optimization model was developed to find the optimum locations for evacuation bus stops for the case study area. The results from this study are very interesting and can aid evacuation planners in the future

An Emergency Evacuation Planning Model for Special Needs Populations Using Public Transit Systems

The need to have evacuation plans in place for ready implementation for special needs populations became evident after catastrophic events such as Hurricane Katrina. For the purpose of this study, special needs populations will include, but are not limited to, people with physical disabilities, older adults, non-English-speaking populations, residents and employees without vehicles, and tourists. The main objective of this study was to evaluate different evacuation procedures for special needs populations from large urban areas using current public transit systems. A microscopic simulation model was constructed to analyze real-life scenarios for evacuation methodologies. A linear programming optimization model was developed to find the optimum locations for evacuation bus stops for the case study area. The results from this study are very interesting and can aid evacuation planners in the future

An Emergency Evacuation Planning Model for Special Needs Populations

The need to have evacuation plans in place for ready implementation for special needs populations became evident after catastrophic events such as Hurricane Katrina. For the purpose of this study, special needs populations will include, but are not limited to, people with physical disabilities, older adults, non-English-speaking populations, residents and employees without vehicles, and tourists. The main objective of this study was to evaluate different evacuation procedures for special needs populations from large urban areas using current public transit systems. A microscopic simulation model was constructed to analyze real-life scenarios for evacuation methodologies. A linear programming optimization model was developed to find the optimum locations for evacuation bus stops for the case study area. The results from this study are very interesting and can aid evacuation planners in the future

Evaluation of Truck Tonnage Estimation Methodologies [Summary]

The primary objective of this study was to evaluate the current methodologies for estimating truck tonnage through a literature review and identify alternatives that could improve Florida\u2019s current truck tonnage formula. The development of a new truck tonnage model was also an option