12 research outputs found

    Digital Twin of the Air Cargo Supply Chain

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    In this paper we develop a digital twin based on the new One Record linked data standard. This enables short-term workload prediction for the various partners in the air cargo supply chain without the need for multiple data exchange interfaces. To the best of our knowledge, it is the first research on the potential benefits of One Record. The concept of the digital twin allows for an overarching optimization of operations in the air cargo supply chain without the necessity of full transparency between all the partners

    Evaluation of Vibration Profiles for ULD Dollies at Air-Cargo Sorting Hubs

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    This study measured and analyzed the vibration characteristics of an important component of the air package shipping environment which has not been previously studied or included in the pre-shipment testing of packages. This is the movement of packages between aircraft after they are flown in to an airport-hub and being taken into a facility to conduct a sort, or after being sorted as they are transferred back on to aircraft. These transfers at airport-hubs between trucks, building sortation facilities and aircraft are done using material handling equipment called “dollies” or carts. These carts often are connected with each other into small trains and then pulled by tug motors on aircraft tarmacs. This study measured the vibration levels experienced by these carts or dollies with and without packages placed in dollies in two different sizes of carts. The data was analyzed to determine the vibration characteristics. Results show that existing vibration test methods do not cover the significant high levels of vibration that are used to simulate truck and aircraft shipments in accordance with existing vibration test methods developed by American Society of Testing and Materials (ASTM) and International Safe Transit Association (ISTA). This paper provides new data on package handling and movement at airport facilities and tarmacs

    Influence of geometric shape on the deformation performance of natural jute/epoxy specimens under axial quasi-static compression

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    The interest in the using of natural composite has been increased significantly in recent years in many application of life due to their distinctive characteristics these like low density, high-energy dissipation ability, and fatigue resistance. Indeed, a seemingly good alternative candidate to metals.This work displays the deformation performance of two different types of geometrical natural composite shapes when subjected to uniaxial quasi-static loading. The purpose is to study the effect of geometrical on the progressive collapse of composite specimens. Two geometrical composite tubes have been fabricated by combination technique of manual lay-up and vacuum bladder moulding. The two types of the proposed tubes, which are the circular and corrugated shape. The experimental work was performed by using bidirectional jute fabric (with 3 layers and 100mm in length) and epoxy resin. Six patterns (three for each one) were tested and evaluated in the same conditions to provide a proper means of comparison between different geometric shapes. The result exhibited both kinds of samples demonstrated stable and progressive deformation with acceptable repeatability during the test process. It also showed the ability to absorb the higher energy of the corrugated samples configuration than the circular samples. Overall, the corrugated pattern configuration can be considered the optimal for crashworthiness structure application compared to a circular composite sample

    Um modelo de simulação de uma linha de produção da Delphi Portugal

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    Esta dissertação insere-se no actual contexto de constante procura pela melhoria do desempenho dos sistemas produtivos em que se pretende estudar a utilização dos recursos produtivos numa das principais linhas de produção da fábrica da Delphi no Seixal. Para o efeito, é desenvolvido um modelo de simulação da linha de produção. O estudo inicia com uma revisão bibliográfica de conceitos e metodologias interligados com a simulação de sistemas. A fase seguinte diz respeito à recolha e tratamento de dados que caracterizam a linha de produção que se pretende simular. Posteriormente, é criado um modelo conceptual da linha de produção que serve de base ao modelo de simulação desenvolvido recorrendo ao software de simulação Arena. Após a simulação do modelo desenvolvido, é realizada a validação do modelo através da análise comparativa de algumas medidas de desempenho resultantes da simulação e do sistema real. Por último é realizada a discussão de resultados e são tecidas considerações que suportam os resultados obtidos e apoiam a diferença de resultados verificada

    Mejora de la operación de estiba y desestiba en aeronaves comerciales de una empresa que brinda servicios aeropuertarios

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    El presente trabajo nace de la necesidad de mejorar la operación de estiba y desestiba de aviones comerciales de una empresa de servicios aeroportuarios. Esto se debe a que, actualmente, los clientes (las aerolíneas) han tomado mayor importancia a la gestión de la carga, debido a su influencia en los costos y la percepción de los clientes hacia la aerolínea. El objetivo del estudio fue determinar la cantidad de recursos para cumplir eficientemente con los tiempos de operación requeridos por los clientes. El proceso que se llevó a cabo para cumplir este objetivo consistió, en primer lugar, en la identificación de metodologías; luego, se propusieron las mejoras y; finalmente, estas se sometieron a una evaluación técnica y económica. En primera instancia, se decidió aplicar la simulación de eventos discretos, empleando el software Arena. Esta metodología consiste en imitar un sistema utilizando un conjunto de métodos y aplicaciones. Asimismo, se obtiene como beneficio el analizar los resultados de la operación en distintos escenarios, sin tener que aplicarlos en la vida real. Para este caso, se optimizaron dos modelos de simulación, en el primero se pretende determinar la cantidad de recursos utilizando el método actual y en el segundo, se hace una variación del modo de operación real. Al analizar los resultados del proceso de optimización, se logra cumplir con los objetivos de los tiempos de operación, reduciéndolos en un 26%; asimismo, la cantidad de mano de obra disminuye un 33%, lo cual permite a la empresa atender un 50% más de aviones. Cabe resaltar que para lograr estos resultados, implica una inversión de 29,790 dólares; sin embargo, se obtiene un margen beneficio costo de 2.73, concluyendo que es factible la propuesta. Por último, se recomienda emplear esta propuesta, ya que permitirá atender la futura demanda, considerando los proyectos de expansión del Aeropuerto Internacional Jorge Chávez. Además, la versatilidad de este modelo de simulación permite ampliar el alcance del estudio y añadir las operaciones para los aviones comerciales de fuselaje ancho y los de carga.Tesi

    An integrated framework for freight forwarders:exploitation of dynamic information for multimodal transportation

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    Advent of real-time information broadcasting technologies, growth in demand for air-cargo, and increased congestion and variability on air-road network, are the main forces compelling today\u27s air-freight forwarders to improve their operational decision-making to be more competitive and responsive to needs of customers. This research studies the air-cargo transportation on both road (short-haul) and air (long haul) network from the perspective of a mid-size freight forwarder. We develop a routing algorithm for congestion avoidance on air-network based on historical data and introduce an innovative approach to incorporate real-time information to enable dynamic routing of cargo on a stochastic air-network. In the road network, we introduce a new class of pickup and delivery problems to carry out the customer load pickups, fleet management, cargo-to-flight assignments, and airport deliveries in a multiple airport region under alternative access airport policy. The main contributions of this research to the air-cargo literature are the study of the value of real-time information and introduction of the concept of dynamic air-cargo routing. In addition, this is the first study that provides an operational framework to implement the alternative access airport policy. This research also contributes to operations research and logistics literature by introducing a new class of pickup and deliveries with time-sensitive and pair-dependent cost structure. It also contributes an innovative algorithm based on successive subproblem solving for Lagrangian decomposed mixed integer programming that shows to be efficient in obtaining near optimal solutions in reasonable time. The performances of the algorithms presented in this research are tested through experimental and real-world case studies. The results demonstrate that dynamic routing with real-time information can dramatically improve delivery reliability and reduce expected cost on the air-network. Moreover, they confirm that alternative access airport policy can greatly enhance a forwarder\u27s options and reduce the operational and service costs while improving the service levels

    Multikriterielle Ablaufplanung und -steuerung in dynamischen und stochastischen Umgebungen : Ein Beitrag zur Erstellung robuster Ablaufpläne für die Frachtabfertigung in Luftfrachtterminals

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    Luftfrachtterminals stellen die zentrale Schnittstelle für den Umschlag von Fracht in der Luftfrachttransportkette dar. Ein stetiges Wachstum des globalen Luftfrachtbedarfs in Kombination mit steigenden Sicherheitsanforderungen stellt die Frachtabfertigung innerhalb der kapazitativ beschränkten Terminals vor neue Herausforderungen. Eine effiziente Ablaufplanung und -steuerung der Frachtabfertigungsaufträge ist daher essenziell, um die Fracht mit der für den Kunden gewohnten Servicequalität zu bearbeiten. In der vorliegenden Arbeit wird ein Ablaufplanungs- und -steuerungssystem in Form einer Architektur umgesetzt, das eine proaktiv-reaktive Ablaufplanung ermöglicht und dabei die dynamische und stochastische Systemumgebung berücksichtigt. Die rollierende proaktive Ablaufplanung stellt das zentrale Element der Architektur dar. Diese dient der Erstellung robuster Ablaufpläne, die eine Immunisierung gegenüber stochastischen Bearbeitungszeiten der Frachtabfertigungsaufträge gewährleisten. Grundlage für die Quantifizierung der Bearbeitungszeitunsicherheiten neuer Aufträge stellen Informationen über historische Abfertigungsaufträge dar, aus denen ein Informationsstand abgeleitet wird. Dieses Vorgehen gewährleistet die kontinuierliche Adaption der Ablaufplanung an sich ändernde Prozessunsicherheiten bei der Bearbeitung von Fracht. Ergänzend werden reaktive Maßnahmen im Rahmen der Ablaufsteuerung aufgezeigt, die eine ereignisorientierte Revision des aktiven Ablaufplans ermöglichen. Die erstellte Architektur wird anhand realer und synthetischer Testinstanzen validiert. Die Validierungsergebnisse zeigen, dass der vorgestellte Ansatz ein effektives Konzept darstellt, um die Robustheit erstellter Ablaufpläne zu erhöhen und die Ablaufplanung automatisiert an bestehende Prozessunsicherheiten anzupassen.Air cargo terminals represent the major interface in the air freight transport chain for the transshipment of freight. A continuous growth of the global demand for air freight combined with increased safety requirements pose new challenges to the freight handling within the capacity restricted terminals. Therefore, an efficient scheduling and control of the freight handling jobs is essential for handling the freight with the service quality the customer is used to. In the present work a scheduling and control system in the form of an architecture is developed that enables a proactive-reactive scheduling considering the dynamic and stochastic system environment. The rolling proactive scheduling represents the central element of the architecture. It is used to create robust schedules, which ensure the immunization against stochastic processing times of the freight handling jobs. The basis to quantify the processing time uncertainties of new jobs are information about historical freight handling jobs, from which an information base is derived. This approach ensures the continuous adaptation of the scheduling system to changing process uncertainties of the freight handling jobs. Additionally, reactive methods for the sequence control are illustrated that enable an event-oriented revision of the active schedule. The developed architecture is validated on real and synthetic test instances. The validation results show the effectiveness of the presented approach to increase the robustness of created schedules and to automatically adapt the scheduling process to existing process uncertainties.von Simon Boxnick, M. Sc. ; Dekanin: Prof. Dr. Caren Sureth-Sloane, Referent: Prof. Dr.-Ing. habil. Wilhelm Dangelmaier, Korreferentin: Prof. Dr. Leena SuhlTag der Verteidigung: 10.05.2016Universität Paderborn, Fakultät für Wirtschaftswissenschaften, Univ., Dissertation, 201

    Workplace values in the Japanese public sector: a constraining factor in the drive for continuous improvement

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    Air cargo operations evaluation and analysis through simulation

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    This paper illustrates the use of simulation for evaluating and analyzing air cargo operations at one of the new state-of-the art cargo facilities at Toronto Pearson Airport. The establishment of a facility equipped with some of the latest in modern material handling systems available today and a computerized-based inventory control system that interfaces with all aspects of its cargo operations, has driven the airline company involved in this study to developing new processes to ensure that products and services are aligned with customers' needs. One of the challenges faced is a lack of an evaluation tool that can be used to quantitatively evaluate and compare different policies, business practices and processes within a given set of operational and business constraints. This work aims in developing such an evaluation tool. We describe the modeling approach, the challenges involved and the potential use of the simulation tool. Preliminary results are also reported

    AIR CARGO OPERATIONS EVALUATION AND ANALYSIS THROUGH SIMULATION

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    This paper illustrates the use of simulation for evaluating and analyzing air cargo operations at one of the new stateof-the art cargo facilities at Toronto Pearson Airport. The establishment of a facility equipped with some of the latest in modern material handling systems available today and a computerized-based inventory control system that interfaces with all aspects of its cargo operations, has driven the airline company involved in this study to developing new processes to ensure that products and services are aligned with customers’ needs. One of the challenges faced is a lack of an evaluation tool that can be used to quantitatively evaluate and compare different policies, business practices and processes within a given set of operational and business constraints. This work aims in developing such an evaluatio
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