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La enseñanza en el área de simulación de eventos discretos requiere integrar una variedad de conceptos teóricos y ponerlos en práctica a través de la creación y ejecución de modelos abstractos de simulación, con el objetivo de recopilar información que pueda traspolarse hacia los sistemas reales. Para construir modelos, ejecutarlos y analizar los resultados de cada ejecución se utilizan herramientas de software cada vez más sofisticadas que permiten expresar los elementos de los modelos en términos de entidades abstractas y relaciones, y que recopilan gran cantidad de datos y estadísticas sobre cada una de estas entidades del modelo. GPSS es una de estas herramientas, y se compone de un lenguaje de programación por bloques y un motor de simulación que traduce estos bloques en distintas entidades del modelo. A pesar de que su primera versión data de 1961, GPSS es aún muy utilizado por profesionales y empresas, y es una de las herramientas más utilizadas para la enseñanza de simulación de eventos discretos por instituciones académicas de todo el mundo.  El avance de la capacidad de cómputo de las computadoras ha permitido incorporar una mayor cantidad de herramientas y funciones a las distintas implementaciones de GPSS. Mientras que esto representa una ventaja para sus usuarios, requiere también un cada vez mayor esfuerzo por parte de los docentes para enseñar a sus estudiantes a aprovechar todo su potencial. Muchos docentes e investigadores han buscado optimizar la enseñanza de simulación de eventos discretos desde múltiples ángulos: la organización del curso y la metodología de enseñanza, la creación de elementos de aprendizaje que ayuden a aplicar los distintos elementos teóricos, la generación de herramientas para construir modelos GPSS, y la construcción de herramientas para comprender el motor de simulación por dentro. En esta tesis se introduce una herramienta de software que permite construir modelos GPSS de manera interactiva, cuyo diseño fue pensado para integrar los elementos teóricos del curso con los objetos y entidades de GPSS. Esta herramienta también permite ejecutar estos modelos y analizar con alto nivel de detalle su evolución a través del tiempo de simulación, lo que permite a los estudiantes comprender cómo funciona el motor de simulación y cómo interactúan las distintas entidades entre sí. Se incluye también una propuesta de enseñanza basada en una fuerte participación de los estudiantes, que, por medio de esta nueva herramienta, les permite incorporar los conceptos más fácilmente. Esta propuesta de enseñanza fue puesta a prueba con alumnos del área de sistemas, quienes tomaron un curso que contiene los mismos elementos teóricos y prácticos de un curso tradicional, pero con una organización diferente. Entre los resultados logrados se destacan una reducción del tiempo requerido para aprender los conceptos de GPSS cercana al 50%, una mayor capacidad por parte de los alumnos para asimilar conceptos y derivar nuevos conceptos por sí solos, a partir de conceptos adquiridos previamente.

The thesis proposes a method for teaching computer simulation. The method involves the use of a large-scale real-life project which had been carried out by the author on a consultancy basis. This project has been developed into a teaching package which is intended for a wide spectrum of students, thus little knowledge of mathematics is assumed. This method has been found to be the most successful one by the author in over twenty years of experience with different types of students and this particular package has been tried successfully with a group of students in Hong Kong. The.real system and the relevant problems involved are first described and considered. From this an extremely simplified version is then extracted. Solution methods are considered and the usefulness of simulation demonstrated. The tools required for a simulation are then introduced, the simulation language used being GPSS which is considered by the author to be the most appropriate on the basis of ease of learning and future usefulness. In a series of steps realistic complications are added to this simple system while in parallel the required extra elements of the simulation language are introduced building up to the final simulation of the real system by the students who will by then have a thorough grasp of GPSS. They will also have had the experience of developing a full-scale simulation model. At this stage the students will be in a position to apply their knowledge and experience to problems in other fields and the author hopes that the lecturer will be motivated to develop similar projects for teaching in other areas.

The purpose of this research report is to compare two simulation languages; GASP and GPSS. An economical comparison was performed by simulating the same system in each language and examine parameters such as run time, core size, program time, and debug time. A statistical comparison of the results of the system simulation was also performed using a 90% confidence level testing procedure. The system simulated was the proposed Orlando Police Department Automatic Vehicle Locator (AVL) Operational System.

This thesis report discusses the research that led to the interfacing of the latest version of GPSS, namely GPSS/H, and GKS, a graphics system which allows programs to support a wide variety of graphics devices. The objective of the research was to represent the results of a syntactically and logically correct GPSS simulation model graphically. A computer program to modify a running GPSS program to a form compatible for graphical emulation was developed. The modifier program identifies the event causing statements in the GPSS program and inserts CALL statements to invoke external subroutines to record these events. Further, it also adds CALL statements to record the statistics for the queues, facilities and storages in the model. The data recorded is in the form of data files. An animation program which takes as input, the data generated by the modified GPSS program was also developed. The GPSS programmer needs only to take care of the correct modeling of the system and know nothing at all about graphics and animation. / Master of Science

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Submitted by Algacilda Conceição (algacilda@sibi.ufrj.br) on 2018-03-28T15:08:02Z No. of bitstreams: 1 133515.pdf: 4734804 bytes, checksum: c041379c0624b5b5f50a1b0bbe049897 (MD5) / Made available in DSpace on 2018-03-28T15:08:02Z (GMT). No. of bitstreams: 1 133515.pdf: 4734804 bytes, checksum: c041379c0624b5b5f50a1b0bbe049897 (MD5) Previous issue date: 1973-10 / Construção de modelos de simulação dos principais sistemas de transmissão de dados, operando interativamente. Supõe-se um conjunto de terminais conectados, através de concentradores, a um sistema computacional constituído por um único computador central ou, uma rede computadores. Para cada sistema foi desenvolvido um programa codificado em GPSS (General Purpose Simulation Systems - IBM) e os resultados obtidos para os diferentes sistemas, operando em diversas circunstâncias, evidenciam a utilidade de tais modelos na avaliação de projetos de redes de teleprocessamento. / Design of simulation models for Data Transmission Systems operating interactively. It is supposed that a set of terminals is connected, through concentrators, to one central computer or a computer network. For each system, a model codified in GPSS (General Purpose Simulation System - IBM) was developped and the results of the simulation of these Systems, operating under different circunstances, makes evident the usefulness of such models in Teleprocessing Network design evaluation.

This thesis is aimed at studying the open pit truck- shovel haulage systems using computer simulation approach. The main goal of the study is to enhance the analysis and comparison of heuristic truck dispatching policies currently available and search for an adaptive rule applicable to open pit mines. For this purpose, a stochastic truck dispatching and production simulation program is developed for a medium size open pit mine consisting of several production faces and a single dump site using GPSS/H software. Eight basic rules are modeled in separate program files. The program considers all components of truck cycle and normal distribution is used to model all these variables. The program asks the user to enter the number of trucks initially assigned to each shovel site. Full-factorial simulation experiments are made to investigate the effects of several factors including the dispatching rules, the number of trucks operating, the number of shovels operating, the variability in truck loading, hauling and return times, the distance between shovels and dump site, and availability of shovel and truck resources. The breakdown of shovel and trucks are modeled using exponential distribution. Three performance measures are selected as truck production, overall shovel utilization and overall truck utilizations. Statistical analysis of the simulation experiments is done using ANOVA method with Minitab software. Regression analysis gives coefficient of determination values, R2, of 56.7 %, 84.1 %, and 79.6 % for the three performance measures, respectively. Also, Tukey&rsquo / s method of mean comparison test is carried out to compare the basic dispatching rules. From the results of statistical analysis, it is concluded that the effects of basic truck dispatching rules on the system performance are not significant. But, the main factors affecting the performances are the number of trucks, the number of shovels, the distance between the shovels and dump site, finally the availability of shovel and truck resources. Also, there are significant interaction effects between these main factors. Finally, an adaptive rule using the standardized utilization of shovels and trucks is developed.

Multi-agent robot systems, especially for mobile robots in dynamic environments interacting with humans, have seen an increased interest over the past years. Many vehicle manufactures (e.g.Volvo GTO) have been following the trend and has started investigating a possible implementation of an autonomous-transport robot system for material delivery in production environments.First implementations of a system have been built using ROS2 and initialising static amounts of participating robots.Throughout this thesis, scalability is emphasised to enhance and add new use cases to the system.This thesis investigates possible improvements for the system by adding a dynamic connection handling, which allows robots to connect and disconnect under the system's run time.Furthermore, the performance of the connection handling in the system is evaluated in simulation for increasing system complexity in terms of the amount of connected robots.The first part of the thesis presents an approach for the dynamic connection and disconnection of robots to the network using service client communication approaches.An implementation is tested in a simulation based on an excerpt from the legacy system.Furthermore, two methods are proposed for detecting possible communication losses. The thesis work simulates the increase of the number of robots in the system at different publishing rates. It compares a many to one communication approach, where multiple robots communicate to a central node over one topic, to the one to one communication approach, where multiple robots communicate over particular topics to a central node.The simulations have shown that with an increase of nodes, the average data age and the data miss ratio in the one to one approach were significantly lower than in the multi to one approach.