Impact of dwell time on vertical transportation through discrete simulation in SIMIO

This work has the objective of simulating an elevator system, using SIMIO software. Firstly, two different approaches, and its implementation, will be explained and compared: Vehicle vs. Entity. After selecting the Entity-approach, due to its more flexible processes and the limitations of the Vehicle-approach, it will be used to conduct the simulation experiments. The purpose is to evaluate the impact of dwell time - time in which the elevator remains stopped, allowing for clients to enter and exit - in the performance of the system. That will be achieved analysing the impact on the total time - spent by clients from placing a call until reaching its destination - number of clients inside the system and waiting for the elevator, waiting time, elevator occupation and number of elevator movements. The analysis of the results indicates that, for the properties defined, the best time for the elevator to stay with its doors open is around 10 seconds.This work has been supported by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEst-OE/EEI/UI0319/2014 (ALGORITMI).info:eu-repo/semantics/publishedVersio

Analysis of an elevator system using discrete event simulation: case study

This paper documents the work conducted to simulate an elevator system, using SIMIO software. The modelled system represents a case study that was analyzed in a hospital at Braga, Portugal. A previ-ous work on the same case study concluded that the best dwell time configuration would be around 10 seconds, however it did not consider the impact of different client demand on the elevator system. In this sense, this paper analyses the impact of both parameters on the performance of the system. This will be achieved by analyzing the impact on the total time spent by clients in the system, the number of clients inside the system, and waiting for the elevator, waiting time, average elevator occupation and number of elevator movements. Conclusions and future work agenda were discussed in the conclusions section.This work has been supported by FCT -Fundacao para a Ciencia e Tecnologia in the scope of the project: PEstOE/EEI/UI0319/2014 (ALGORITMI)

Historia, evolución y perspectivas de futuro en la utilización de técnicas de simulación en la gestión portuaria: aplicaciones en el análisis de operaciones, estrategia y planificación portuaria

Programa Oficial de Doutoramento en Análise Económica e Estratexia Empresarial. 5033V0[Resumen] Las técnicas de simulación, tal y como hoy las conocemos, comenzaron a mediados del siglo XX; primero con la aparición del primer computador y el desarrollo del método Monte Carlo, y más tarde con el desarrollo del primer simulador de propósito específico conocido como GPS y desarrollado por Geoffrey Gordon en IBM y la publicación del primer texto completo dedicado a esta materia y llamado the Art of Simulation (K.D. Tocher, 1963). Estás técnicas han evolucionado de una manera extraordinaria y hoy en día están plenamente implementadas en diversos campos de actividad. Las instalaciones portuarias no han escapado de esta tendencia, especialmente las dedicadas al tráfico de contenedores. Efectivamente, las características intrínsecas de este sector económico, le hacen un candidato idóneo para la implementación de modelos de simulación con propósitos y alcances muy diversos. No existe, sin embargo y hasta lo que conocemos, un trabajo científico que compile y analice pormenorizadamente tanto la historia como la evolución de simulación en ambientes portuarios, ayudando a clasificar los mismos y determinar cómo estos pueden ayudar en el análisis económico de estas instalaciones y en la formulación de las oportunas estrategias empresariales. Este es el objetivo último de la presente tesis doctoral.[Resumo] As técnicas de simulación, tal e como hoxe as coñecemos, comezaron a mediados do século XX; primeiro coa aparición do computador e o desenvolvemento do método Monte Carlo e máis tarde co desenvolvemento do primeiro simulador de propósito específico coñecido como GPS e desenvolvido por Geoffrey Gordon en IBM e a publicación do primeiro texto completo dedicado a este tema chamado “A Arte da Simulación” (K.D. Tocher, 1963). Estas técnicas evolucionaron dun xeito extraordinario e hoxe en día están plenamente implementadas en diversos campos de actividade. As instalacións portuarias non escaparon desta tendencia, especialmente as dedicadas ao tráfico de contenedores. Efectivamente, as características intrínsecas deste sector económico, fanlle un candidato idóneo para a implementación de modelos de simulación con propósitos e alcances moi variados. Con todo, e ata o que coñecemos, non existe un traballo científico que compila e analiza de forma detallada tanto a historia como a evolución da simulación en estes ambientes portuarios, clasificando os mesmos e determinando como estes poden axudar na análise económica destas instalacións e na formulación das oportunas estratexias empresariais. Este é o último obxectivo da presente tese doutoral.[Abstract] Simulation, to the extend that we understand it nowadays, began in the middle of the 20th century; first with the appearance of the computer and the development of the Monte Carlo method, and later with the development of the first specific purpose simulator known as GPS developed by Geoffrey Gordon in IBM. This author published the first full text devoted to this subject “The Art of Simulation” in 1963. These techniques have evolved in an extraordinary way and nowadays they are fully implemented in different fields of activity. Port facilities have not escaped this trend, especially those dedicated to container traffic. Indeed, the intrinsic characteristics of this economic sector, make it a suitable candidate for the implementation of simulation with very different purposes and scope. However, to the best of our knowelegde, there is not a scientific work that compiles and analyzes in detail both, the history and the evolution of simulation in port environments, contributing to classify them and determine how they can help in the economic analysis of these facilities and in the formulation of different business strategies. This is the ultimate goal of this doctoral thesis

Hyperconnected parcel logistic hubs

Hyperconnected Parcel Logistic Hubs Shannon Buckley 144 Pages Advised By Dr. Benoit Montreuil This thesis focuses on the design of a new era of hub in the parcel logistics industry. Parcel logistics hubs (hubs) are the connective tissue in parcel logistics networks, sorting and transferring parcels from one vehicle to another as quickly as possible. However, as the demand for eCommerce surges, customer expectations for delivery speed rise and as the COVID pandemic creates disruptions throughout supply chains, new solutions are needed to ease the strain on the system. Current parcel logistics hubs are massive facilities filled to the brim with miles of fixed conveyor systems and expensive sorting machines. These hubs were built to handle large volumes of parcels at extremely fast speeds. However, with their fixed resources, they must have all operations finely scheduled and are not able to respond dynamically to disruptions such as an unexpected wave of parcels, resulting in backlogs and unhappy customers. In this thesis we help the transition away from this old, outdated hub design towards, dynamic, flexible hyperconnected parcel logistics hubs. In Chapter 2 we introduce a method for dynamically updating forecasts of the demand that hubs will face in the near future. We describe the new method and then compare it to existing methods with computational experiments. In Chapter 3 we present a pilot design for a new hyperconnected parcel logistics hub called the robotic logistics hub. We introduce designs for the layout as well as the operations and control of the hub, and finish with a comparative study of our hub’s performance against an existing hub from our industry partner. In Chapter 4 we present our novel simulation platform built to enable the analysis of new technology such as the robotic logistics hub. The simulator uses a hybrid discrete event / agent based modelling approach as well as a unique modular construction to allow for a highly flexible tool capable of providing deep insight into many facets of the proposed robotic logistics hub.Ph.D

Energy Academic Group Compilation of Abstracts 2012-2016

This report highlights the breadth of energy-related student research at NPS and reinforces the importance of energy as an integral aspect of today's Naval enterprise. The abstracts provided are from theses and a capstone project report completed by December 2012-March 2016 graduates.http://archive.org/details/energyacademicgr109454991

Gestion des systèmes automatisés d'entreposage : simulation, optimisation et résultats empiriques

Les systèmes automatisés d'entreposage {Automated Storage and Retrieval Systems- AS/RS) sont considérés aujourd'hui comme une technologie de pointe dans le domaine de l'entreposage et de la distribution à haut débit. L'implantation d'un tel système représente un investissement corporatif majeur, il est donc attendu que son niveau de performance soit élevé. Ce niveau de performance, pour un environnement donné, est le résultat d'un ensemble de décisions relatives à la fois au design et au contrôle du système. Pour cette raison, tant aux niveaux industriel qu'académique, on cherche à développer des approches permettant de modéliser, concevoir et contrôler au mieux ces systèmes qui jouent un rôle critique dans les chaînes logistiques modernes. À cette fin, plusieurs approches issues de la recherche opérationnelle peuvent être appliquées. Cette thèse comporte quatre articles, présentant chacun un aspect distinct de l'étude des AS/RS. Nous présentons, dans le premier article, une revue de littérature traitant des approches de modélisation des AS/RS. L'étude met l'accent sur les hypothèses de modélisation employées dans les différents articles et qui ne sont pas toujours intuitives, ni même mentionnées. Cette réalité fait en sorte qu'il est parfois très difficile d'exploiter les résultats de recherches précédentes afin de les transposer dans un autre contexte. En plus d'isoler les hypothèses de modélisation, nous présentons une structure séparant les différentes questions de recherche en fonction des problèmes étudiés. Les résultats de cette revue prennent la forme d'une synthèse permettant d'associer, pour un problème donné, les études et résultats provenant de contextes similaires. Nous proposons dans le second article un modèle de simulation à événements discrets conçu pour étudier les AS/RS à charge unitaire. En prenant appui sur la programmation orientée-objet, le modèle a été conçu de manière à pouvoir aisément modéliser plusieurs configurations, comme par exemple les systèmes à plusieurs allées ou les AS/RS visant à gérer la collecte de petits items dans des contenants. Une description détaillée du moteur de simulation est donnée. C'est grâce à ce modèle que les chapitres subséquents ont pu voir le jour, en permettant l'étude empirique de ces systèmes hautement complexes et dynamiques. Dans le troisième article, nous présentons une étude sur le problème de gestion de l'espace dans les AS/RS. Ce problème consiste à définir, pour chaque localisation de stockage, le ou les produits pouvant y être stockés. Nous nous intéressons principalement à l'étude de l'entreposage par zones dont le nombre peut varier entre une seule zone et autant de zones qu'il y a de produits. La gestion de l'espace a suscité beaucoup d'intérêt scientifique vers la fin des années 70. Plusieurs modèles analytiques ont été formulés, résultant en certaines conclusions largement acceptées dans tous les milieux. Cependant, nous constatons que la validité de ces modèles analytiques repose sur certaines hypothèses restrictives. À l'aide du modèle de simulation présenté, nous montrons que ces conclusions ne tiennent plus lorsque nous nous transposons dans un contexte réaliste. Ce nouveau résultat nous amène à voir la gestion de l'espace en fonction des caractéristiques des produits entreposés. Dans le quatrième article, nous portons notre attention sur le problème de séquencement des requêtes dans un AS/RS. Le séquencement des requêtes consiste à définir l'ordre dans lequel les requêtes de stockage et de collecte seront complétées selon un horizon à durée déterminée, dans un objectif de minimisation du temps de cycle moyen. Cela revient à maximiser le rendement du système. Pour ce faire, nous proposons une adaptation des heuristiques de la littérature pour traiter le cas de séquencement dynamique, puis nous proposons une des premières formulations mathématiques au problème. Par la suite, nous évaluons les opérations du système à l'aide du modèle de simulation détaillé dans le deuxième article. Les résultats empiriques obtenus illustrent l'effet positif du séquencement sur la performance du système en plus de fournir une comparaison des différentes approches de séquencement étudiées. À travers ces quatre chapitres, nous démontrons que la simulation et l'optimisation des systèmes automatisés d'entreposage posent plusieurs défis. Nous avons présenté un modèle de simulation robuste qui a permis de faire avancer les connaissances dans le domaine de la gestion de l'espace et du séquencement des requêtes

Application of systems simulation for predicting and optimizing energy requirements for a HDF moulded door skin manufacturing production plant

In today’s straggling economy, manufacturing companies make a great effort to\ud maintain their competitive advantage. Daily they face challenges o f improving\ud efficiency and reducing cost. In order to survive in this rough environment, tough\ud decisions need to be taken. The major challenge that most manufacturing companies\ud face consists in reducing their energy consumption, as this represents one o f their\ud major costs. The highly automated production plants are usually equipped with the\ud latest energy monitoring systems which capture the energy consumption throughout\ud the entire company. These systems produce high quantities o f data that most o f the\ud time is very difficult and costly to analyse. This is the first major challenge\ud companies face. Looking at this data, the plants’ engineers can get a rough\ud understanding o f where the major energy losses occur and they can come up with\ud solutions. The next tough challenge consists in calculating the return on each project\ud that can be implemented. This requires an in depth analysis that takes time and\ud money to perform. Simulation is one o f the technologies that can represent a solution\ud to these problems.\ud Even though simulation has been used so far in manufacturing facilities for\ud modelling supply chain management, production management and business\ud processes, its applications in managing the energy consumption within\ud manufacturing companies represents a new and innovative research domain. This\ud prompted the research undertaken for the present thesis. The main focus o f this\ud research is to analyse production management in a manufacturing facility and\ud correlate it with the energy consumption. The research initially concentrates on\ud different simulation methodologies and their application in the current\ud manufacturing space. Literature relating to the correlation o f energy consumption\ud with production management has also been reviewed. This review identified very\ud few previous instances o f where simulation tools where used to predict the energy\ud consumption in a manufacturing facility. This research brings a novel approach to\ud investigating the adaptability o f industrial simulation processes and tools for\ud modelling the energy consumption with respect to a variable production output. The\ud end result o f this process consists in a better understanding o f the production system\ud and the energy loses which were incorporated in the simulation model.\ud The simulation model was validated using real world data collected from Masonite -\ud the case study company. This was closely followed by the creation o f different\ud scenarios that were analysed and which predicted a lowering in the energy\ud consumption that could reach over 9%

Naval Research Program 2021 Annual Report

NPS NRP Annual ReportThe Naval Postgraduate School (NPS) Naval Research Program (NRP) is funded by the Chief of Naval Operations and supports research projects for the Navy and Marine Corps. The NPS NRP serves as a launch-point for new initiatives which posture naval forces to meet current and future operational warfighter challenges. NRP research projects are led by individual research teams that conduct research and through which NPS expertise is developed and maintained. The primary mechanism for obtaining NPS NRP support is through participation at NPS Naval Research Working Group (NRWG) meetings that bring together fleet topic sponsors, NPS faculty members, and students to discuss potential research topics and initiatives.Chief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

13th International Postgraduate Research Conference 2017 : conference proceedings

Welcome to the 13th International Postgraduate Research Conference (IPGRC 2017) hosted by the School of the Built Environment at University of Salford, UK. This year’s IPGRC is organised as part of the International Research Week 2017- ‘Shaping Tomorrow’s Built Environment: Construction and Design for the Modern World’ and also the year we celebrate the 50th anniversary of Salford as a University, which makes this year’s conference very special. This conference creates a unique opportunity for researchers from Salford and other parts of the world to share their research interests, and outputs and to network and interact within a professional and friendly environment, with high profile academics and leaders within the built environment. This year’s conference brings together participants from a number of countries including the UK, USA, Australia, New Zealand, Canada, Sri Lanka, Hong Kong, Iran, Italy, Ireland, Norway, India, Brazil, South Korea, Nigeria, Turkey, UAE, South Africa, Iraq, Ghana, Estonia, Saudi Arabia and many more. The conference received over 100 papers and posters covering the following themes: • Business, Economics and Finance • Property and Project Management • ICT, Technology and Engineering • People, Skills and Education • Design and Urban Development • Sustainability and Environmental Systems Conference will provide a forum for novel discussions into the development and application of new and emerging practices to challenge current design and construction practice in the areas of people, process and technology issues. On behalf of School of the Built Environment, the conference co-chairs and organisers, we wish you an enjoyable and fruitful experience. We hope that you will obtain useful feedback to your research work, gain insight from work of others and forge connections for future