52 research outputs found

    An improved tabu search for airport gate assignment.

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    Kwan, Cheuk Lam.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.Includes bibliographical references (p. 115-118).Abstract also in Chinese.Chapter 1 --- Introduction --- p.9Chapter 1.1 --- The Gate Assignment Problem --- p.9Chapter 1.2 --- Contributions --- p.10Chapter 1.3 --- Formulation of Gate Assignment Problem --- p.11Chapter 1.4 --- Organization of Thesis --- p.13Chapter 2 --- Literature Review --- p.15Chapter 2.1 --- Introduction --- p.15Chapter 2.2 --- Formulations of Gate Assignment Problems --- p.15Chapter 2.2.1 --- Static Gate Assignment Model --- p.16Chapter 2.2.1.1 --- Total Passenger Walking Distance --- p.17Chapter 2.2.1.2 --- Waiting Time --- p.20Chapter 2.2.1.3 --- Unassigned Flights --- p.21Chapter 2.2.2 --- Stochastic and Robust Gate Assignment Model --- p.22Chapter 2.2.2.1 --- Idle Time --- p.22Chapter 2.2.2.2 --- Buffer Time --- p.23Chapter 2.2.2.3 --- Flight Delays --- p.23Chapter 2.2.2.4 --- Gate Conflicts --- p.24Chapter 2.3 --- Solution Methodologies --- p.25Chapter 2.3.1 --- Expert System Approaches --- p.25Chapter 2.3.2 --- Optimization --- p.27Chapter 2.3.2.1 --- Exact Methods --- p.27Chapter 2.3.2.2 --- Heuristic Approaches --- p.28Chapter 2.3.2.3 --- Meta-Heuristics Approaches --- p.29Chapter 2.3.2.4 --- Tabu Search and Path Relinking --- p.31Chapter 2.4 --- Current Practice of Gate Assignment Problems --- p.32Chapter 2.5 --- Summary --- p.32Chapter 3 --- Tabu Search --- p.34Chapter 3.1 --- Introduction --- p.34Chapter 3.2 --- Mathematical Model --- p.34Chapter 3.3 --- Principles of Tabu Search --- p.36Chapter 3.4 --- Neighborhood Structures --- p.38Chapter 3.4.1 --- Insert Move --- p.38Chapter 3.4.2 --- Exchange Move --- p.39Chapter 3.5 --- Short Term Memory Structure --- p.41Chapter 3.6 --- Aspiration Criterion --- p.42Chapter 3.7 --- Intensification and Diversification Strategies --- p.43Chapter 3.8 --- Tabu Search Framework --- p.45Chapter 3.8.1 --- Initial Solution --- p.45Chapter 3.8.2 --- Tabu Search Algorithm --- p.46Chapter 3.9 --- Computational Studies --- p.52Chapter 3.9.1 --- Parameters Tuning --- p.52Chapter 3.9.1.1 --- Fine-tuning a Tabu Search Algorithm with Statistical Tests --- p.53Chapter 3.9.1.2 --- Tabu Tenure --- p.54Chapter 3.9.1.3 --- Move Selection Strategies --- p.56Chapter 3.9.1.4 --- Frequency of Exchange Moves --- p.59Chapter 3.9.2 --- Comparison the Fine-tuned TS with original TS --- p.62Chapter 3.10 --- Conclusions --- p.63Chapter 4 --- Path Relinking --- p.65Chapter 4.1 --- Introduction --- p.65Chapter 4.2 --- Principles of Path Relinking --- p.65Chapter 4.2.1 --- Example of Path Relinking --- p.66Chapter 4.3 --- Reference Set --- p.68Chapter 4.3.1 --- Two-Reference-Set Implementation --- p.71Chapter 4.3.1.1 --- Random Exchange Gate Move --- p.72Chapter 4.4 --- Initial and Guiding Solution --- p.73Chapter 4.5 --- Path-Building Process --- p.74Chapter 4.6 --- Tabu Search Framework with Path Relinking --- p.78Chapter 4.6.1 --- Computational Complexities --- p.82Chapter 4.7 --- Computational Studies --- p.82Chapter 4.7.1 --- Best Configuration for Path Relinking --- p.83Chapter 4.7.1.1 --- Reference Set Strategies and Initial and Guiding Criteria --- p.83Chapter 4.7.1.2 --- Frequency of Path Relinking --- p.86Chapter 4.7.1.3 --- Size of Volatile Reference Set --- p.87Chapter 4.7.1.4 --- Size of Non-volatile Reference Set --- p.89Chapter 4.7.2 --- Comparisons with Other Algorithms --- p.94Chapter 5 --- Case Study --- p.98Chapter 5.1 --- Introduction --- p.98Chapter 5.2 --- Airport Background --- p.98Chapter 5.2.1 --- Layout of ICN --- p.98Chapter 5.3 --- Data Preparation --- p.99Chapter 5.3.1 --- Passenger Data --- p.103Chapter 5.4 --- Computational Studies --- p.104Chapter 5.4.1 --- Experiments without Airline Preference --- p.104Chapter 5.4.2 --- Experiments with Airline Preference --- p.106Chapter 5.4.2.1 --- Formulation --- p.106Chapter 5.4.2.2 --- Results --- p.108Chapter 5.5 --- Conclusion --- p.111Chapter 6 --- Conclusion --- p.112Chapter 6.1 --- Summary of Achievement --- p.112Chapter 6.2 --- Future Developments --- p.113Bibliography --- p.115Appendix --- p.119Chapter 1. --- Friedman´ةs Test --- p.119Chapter 2. --- Wilcoxon's Signed Rank Test for Paired Observation --- p.120Chapter 3. --- Hybrid Simulated Annealing with Tabu Search Approach --- p.121Chapter 4. --- Arrival Flight Data of Incheon International Airport --- p.122Chapter 5. --- Departure Flight Data of Incheon International Airport --- p.13

    Collaboration modes and advantages in supply chain

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    This research aims to address supply chain collaboration with a perspective of broader three-dimensional relationship, not a linear two-dimensional relationship discussed broadly in previous research. Case study was adopted for this research, and data collection was mainly conducted via interview. The research results highlighted that supply chain collaborations are common practice across all levels of the pharmaceutical supply chain. The results also indicated that the different strengthen levels of barging power among collaborative partners will influence the achieved advantages at different supply chain levels, including strategic, operational and political levels

    Smart manufacturing and supply chain management

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    In the fourth industrial revolution, smart manufacturing will be characterized by adaptability, resource efficiency and ergonomics as well as the integration of customers and business partners in business and value processes. Business model, operations management, workforce and manufacturing process all face substantial transformations to reasoning the manufacturing process. This paper explores the impacts of smart manufacturing on supply chain management, and develops several propositions to improve supply chain performance under the context of smart manufacturing

    Planning of vehicle routing with backup provisioning using wireless sensor technologies

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    Wireless sensor technologies can be used by intelligent transportation systems to provide innovative services that lead to improvements in road safety and congestion, increasing end-user satisfaction. In this article, we address vehicle routing with backup provisioning, where the possibility of reacting to overloading/overcrowding of vehicles at certain stops is considered. This is based on the availability of vehicle load information, which can be captured using wireless sensor technologies. After discussing the infrastructure and monitoring tool, the problem is mathematically formalized, and a heuristic algorithm using local search procedures is proposed. Results show that planning routes with backup provisioning can allow fast response to overcrowding while reducing costs. Therefore, sustainable urban mobility, with efficient use of resources, can be provided while increasing the quality of service perceived by users.FCT (Foundation for Science and Technology) from Portugal within CEOT (Center for Electronic, Optoelectronic and Telecommunications); [UID/MULTI/00631/2013

    Operating Risk Assessment of Modern Power System in Presence of Flywheel Energy Storage

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    Stochastic perturbations in supply and demand during power system operations have always been a concern for power system operators and/or planners. These concerns have been aggravated in the past decade with large-scale integration of renewable energy sources (RES) such as wind and photovoltaics. The impacts of load fluctuations and/or random outages of major system components during the operation, such as loss of generating unit(s) and transmission line(s) are further aggravated due to increasing addition of intermittent RES in the system. Energy storage systems (ESS) can act as a buffer to maintain the supply-demand balance, and are therefore, gaining considerable attention in modern power system planning. It is important to have the ability to make quantitative assessment of associated risks in the system operation and to explore the potential of suitable resources such as ESS in mitigating these risks. A reliability model of flywheel energy storage system (FESS) suitable for power system operational risk evaluation was developed in the research work presented in this thesis. Appropriate reliability assessment frameworks for different hierarchical levels of power system reliability evaluation were also introduced. The proposed frameworks and models were applied to the IEEE reliability test system and a modified Roy Billinton test system through several case studies. This thesis presents a novel approach to quantify the impact of growing wind penetration on power system operational reliability and quantify the implications of implementing flywheel energy storage systems in mitigating these concerns. The work presented in this thesis provides methodology and indicators that will be valuable in developing operating policies for sustainable wind energy for the future

    Decentralized Orchestration of Open Services- Achieving High Scalability and Reliability with Continuation-Passing Messaging

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    The papers of this thesis are not available in Munin. Paper I: Yu, W.,Haque, A. A. M. “Decentralised web- services orchestration with continuation-passing messaging”. Available in International Journal of Web and Grid Services 2011, 7(3):304–330. Paper II: Haque, A. A. M., Yu, W.: “Peer-to-peer orchestration of web mashups”. Available in International Journal of Adaptive, Resilient and Autonomic Systems 2014, 5(3):40-60. Paper V: Haque, A. A. M., Yu, W.: “Decentralized and reliable orchestration of open services”. In:Service Computation 2014. International Academy, Research and Industry Association (IARIA) 2014 ISBN 978-1-61208-337-7.An ever-increasing number of web applications are providing open services to a wide range of applications. Whilst traditional centralized approaches to services orchestration are successful for enterprise service-oriented systems, they are subject to serious limitations for orchestrating the wider range of open services. Dealing with these limitations calls for decentralized approaches. However, decentralized approaches are themselves faced with a number of challenges, including the possibility of loss of dynamic run-time states that are spread over the distributed environment. This thesis presents a fully decentralized approach to orchestration of open services. Our flow-aware dynamic replication scheme supports both exceptional handling, failure of orchestration agents and recovers from fail situations. During execution, open services are conducted by a network of orchestration agents which collectively orchestrate open services using continuation-passing messaging. Our performance study showed that decentralized orchestration improves the scalability and enhances the reliability of open services. Our orchestration approach has a clear performance advantage over traditional centralized orchestration as well as over the current practice of web mashups where application servers themselves conduct the execution of the composition of open web services. Finally, in our empirical study we presented the overhead of the replication approach for services orchestration

    Optimal Management of Flexible Resources in Multi-Energy Systems

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    Control Strategy for a Small-Scale Microgrid Based on Battery Energy Storage System-Virtual Synchronous Generator (bess-Vsg)

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    As one of widely deployed renewable energy resources, PV power is playing a very important role in microgrids today. It has advantages such as making the best of natural solar energy and being friendly to our environment. In this thesis, solar PV based microgrid is studied using modeling and simulation. Microgrid can run in either grid-connected-mode or islanded-mode. However, there are also some disadvantages for solar power. For solar panel, its output is influenced by weather conditions such as illumination intensity and temperature. In addition, during the control process of grid-connected mode, it is hard to guarantee its output power at the maximum power point all the time. In this thesis, the Maximum Power Point Tracking (MPPT) control for Solar PV energy is used. Besides, the frequency control is also a very important issue for guaranteeing the quality of the electricity in the microgrid. By using an effective way of BESS-VSG, which means Battery Energy Storage System-Virtual Synchronous Generator, the frequency can be controlled to the nominal value faster and more smoothly when there is a fluctuation in the PV power generation and/or load change, leading to higher stability and robustness. This thesis focuses on the modeling and control of the PV and BESS-VSG system, and the proposed modeling and control method are verified in MATLAB/Simulink
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