Sea Container Terminals

Due to a rapid growth in world trade and a huge increase in containerized goods, sea container terminals play a vital role in globe-spanning supply chains. Container terminals should be able to handle large ships, with large call sizes within the shortest time possible, and at competitive rates. In response, terminal operators, shipping liners, and port authorities are investing in new technologies to improve container handling infrastructure and operational efficiency. Container terminals face challenging research problems which have received much attention from the academic community. The focus of this paper is to highlight the recent developments in the container terminals, which can be categorized into three areas: (1) innovative container terminal technologies, (2) new OR directions and models for existing research areas, and (3) emerging areas in container terminal research. By choosing this focus, we complement existing reviews on container terminal operations

Optimization Applied to Transportation Systems

This volume summarizes the results of the first Workshop initiated by the Working Group on Transportation, which was established by the Systems Engineering Committee (SECOM) of the International Federation of Automatic Control (IFAC). Three levels of transportation systems analysis are utilized as a framework: -- Transportation systems planning from a socio-economic point of view; -- Operational planning, mainly focusing on routing and scheduling problems; and, -- Control and guidance of transportation systems. Formal presentations dealing with the state-of-the-art of transportation systems and selected specific topics are included in the proceedings, as well as summaries of panel discussions which followed the individual sessions

High-speed rail safety analysis based on dual-weighted complex network

This study uses a complex network model to analyze the causes of accidents in high-speed railway operations. By identifying the key factors that led to high-speed railway accidents, hidden safety hazards were discovered. This will help improve the operational safety of the U.S. high-speed rail line under construction. The analysis uses the regional high-speed railway network in Guangzhou, China as a case study, including the railway (including high-speed railway) accidents that occurred in the company\u27s jurisdiction from 2013 to 2017. With comparative analysis between general railways and high-speed railways, the changes of high-speed railway safety factors are explored. Data analysis results show that the main accident causes of high-speed railways and general railways have no significant differences in categories, Equipment and human factors are the most important categories of factors leading to accidents. However, there are obvious differences in specific accident factors. Which include the significant impact of driver staff on the safety of high-speed railways, and the safety of high-speed railways is highly sensitive to incidents. Another key factor is the stability of the equipment, especially the performance of the signal system is critical to the operation of high-speed rail. The underlying reasons reflected by these safety defect factors include: In the short term, a large number of equipment purchases and the construction of new railway lines will cause maintenance, driver, and mechanic pressures and staff shortages. The lack of training system leads to insufficient professional quality of maintenance employees and drivers. The proposed strategy includes enhancing the training organization within the operating company, and adjusting the high-speed railway construction and equipment procurement policies should be gentler in order to reduce the pressure on the system and improve the level of safety

Planning with a Receding Horizon for Manipulation in Clutter using a Learned Value Function

Manipulation in clutter requires solving complex sequential decision making problems in an environment rich with physical interactions. The transfer of motion planning solutions from simulation to the real world, in open-loop, suffers from the inherent uncertainty in modelling real world physics. We propose interleaving planning and execution in real-time, in a closed-loop setting, using a Receding Horizon Planner (RHP) for pushing manipulation in clutter. In this context, we address the problem of finding a suitable value function based heuristic for efficient planning, and for estimating the cost-to-go from the horizon to the goal. We estimate such a value function first by using plans generated by an existing sampling-based planner. Then, we further optimize the value function through reinforcement learning. We evaluate our approach and compare it to state-of-the-art planning techniques for manipulation in clutter. We conduct experiments in simulation with artificially injected uncertainty on the physics parameters, as well as in real world tasks of manipulation in clutter. We show that this approach enables the robot to react to the uncertain dynamics of the real world effectively

Optimales Sortieren von Objekten

This thesis is concerned with the problem of optimally rearranging objects, in particular, railcars in a rail yard. The work is motivated by a research project of the Institute of Mathematical Optimization at Technische Universität Braunschweig, together with our project partner BASF, The Chemical Company, in Ludwigshafen. For many variants of such rearrangement problems - including the real-world application at BASF - we state the computational complexity by exploiting their equivalence to particular graph coloring, scheduling, and bin packing problems. We present mathematical optimization methods for determining schedules that are either optimal or close to optimal, and computational results are discussed from both a theoretical and practical point of view. In addition to the railway industry, there are other fields of application in which efficiently rearranging, sorting, or stacking is an important issue. For instance, the results obtained in this thesis could also be applied to solving certain piling problems in warehouses or container terminals.Die Dissertation beschäftigt sich mit dem optimalen Sortieren von Objekten, insbesondere von Güterwagen in Rangierbahnhöfen. Motiviert wurde diese Arbeit durch ein BMBF-gefördertes Projekt mit der BASF, The Chemical Company, in Ludwigshafen. Zahlreiche Varianten derartiger Sortierprobleme werden mathematisch formuliert und komplexitätstheoretisch eingeordnet. Für viele Varianten wird deren Äquivalenz zu bestimmten Graphenfärbungs-, Scheduling- sowie Bin-Packing-Problemen gezeigt. Für mehrere als theoretisch schwer bewiesene Fälle werden schnelle approximative Algorithmen vorgeschlagen, die Lösungen mit einer beweisbaren Güte liefern. Neben heuristischen Methoden werden auch exakte Verfahren zur Bestimmung optimaler Lösungen vorgestellt. Unter anderem handelt es sich bei den eingesetzten exakten Ansätzen um LP- sowie Lagrange-basierte Branch-and-Bound-Verfahren, die auf verschiedenen binären Modellen beruhen. Die Lösungsmethoden werden durch die Auswertung von Rechenergebnissen für reale Daten evaluiert. Den Abschluss der Dissertation bildet eine Kompetitivitätsanalyse diverser Online-Varianten, die dadurch gekennzeichnet sind, dass nicht alle relevanten Informationen zu Beginn der Planung vorliegen. Es sei auf das Verwertungspotenzial der in dieser Arbeit vorgestellten Optimierungsverfahren innerhalb anderer Anwendungsbereiche, in denen Sortieren, Stapeln, Lagern oder Verstauen eine Rolle spielen, hingewiesen

Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes

The book documents 25 papers collected from the Special Issue “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”, highlighting recent research trends in complex industrial processes. The book aims to stimulate the research field and be of benefit to readers from both academic institutes and industrial sectors

How to Make the Most Productive Intervention in a Complex Economic System

Information about supply and demand propagates through supply chains in a queueing network with people and computers as batch information processors. As each batch processor delays propagation of information whilst pursuing optimal local decisions, the effect is delay and distortion of the information that is used to commit resources to actions in the supply chain. This thesis investigates the effect of delay and imperfect information as a source of error, to establish the case for change in research focus from optimal exploitation of physical constraints to optimal exploitation of information. In the context of real world supply chains, the thesis asks "How does one make the most productive intervention in a complex economic system?" and pursues a meta-intervention which perpetually minimises the discovered error-term. Evidence from literature indicates that agent-based modelling permits real-time peer-to-peer communication and distributed optimisation. Based on the literature the research project designs and develops an agent-based model which operates in real-time without batch-processes and can perform incremental multi-objective optimisation under realistic (chronologically progressive) conditions for decision making. The agent based model is then used to investigate two real-world supply chains, as case studies, which reveals a significant improvement of profitability and order-fulfilment. The thesis concludes that agent-based modelling is a very promising direction for "making the most productive intervention" as it reduces delay to a minimum. Finally it recommends that continuous improvement of decision making methods is a role better suited for humans, rather than operational decision making where computers cope much better with the high amount of detailed information

OPTIMIZATION OF RAILWAY TRANSPORTATION HAZMATS AND REGULAR COMMODITIES

Transportation of dangerous goods has been receiving more attention in the realm of academic and scientific research during the last few decades as countries have been increasingly becoming industrialized throughout the world, thereby making Hazmats an integral part of our life style. However, the number of scholarly articles in this field is not as many as those of other areas in SCM. Considering the low-probability-and-high-consequence (LPHC) essence of transportation of Hazmats, on the one hand, and immense volume of shipments accounting for more than hundred tons in North America and Europe, on the other, we can safely state that the number of scholarly articles and dissertations have not been proportional to the significance of the subject of interest. On this ground, we conducted our research to contribute towards further developing the domain of Hazmats transportation, and sustainable supply chain management (SSCM), in general terms. Transportation of Hazmats, from logistical standpoint, may include all modes of transport via air, marine, road and rail, as well as intermodal transportation systems. Although road shipment is predominant in most of the literature, railway transportation of Hazmats has proven to be a potentially significant means of transporting dangerous goods with respect to both economies of scale and risk of transportation; these factors, have not just given rise to more thoroughly investigation of intermodal transportation of Hazmats using road and rail networks, but has encouraged the competition between rail and road companies which may indeed have some inherent advantages compared to the other medium due to their infrastructural and technological backgrounds. Truck shipment has ostensibly proven to be providing more flexibility; trains, per contra, provide more reliability in terms of transport risk for conveying Hazmats in bulks. In this thesis, in consonance with the aforementioned motivation, we provide an introduction into the hazardous commodities shipment through rail network in the first chapter of the thesis. Providing relevant statistics on the volume of Hazmat goods, number of accidents, rate of incidents, and rate of fatalities and injuries due to the incidents involving Hazmats, will shed light onto the significance of the topic under study. As well, we review the most pertinent articles while putting more emphasis on the state-of-the-art papers, in chapter two. Following the discussion in chapter 3 and looking at the problem from carrier company’s perspective, a mixed integer quadratically constraint problem (MIQCP) is developed which seeks for the minimization of transportation cost under a set of constraints including those associating with Hazmats. Due to the complexity of the problem, the risk function has been piecewise linearized using a set of auxiliary variables, thereby resulting in an MIP problem. Further, considering the interests of both carrier companies and regulatory agencies, which are minimization of cost and risk, respectively, a multiobjective MINLP model is developed, which has been reduced to an MILP through piecewise linearization of the risk term in the objective function. For both single-objective and multiobjective formulations, model variants with bifurcated and nonbifurcated flows have been presented. Then, in chapter 4, we carry out experiments considering two main cases where the first case presents smaller instances of the problem and the second case focuses on a larger instance of the problem. Eventually, in chapter five, we conclude the dissertation with a summary of the overall discussion as well as presenting some comments on avenues of future work