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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Determinación de los factores de éxito de la empresa Agroexportadora Ecoandino S.A.C. Para la introducción del café a base de cebada torrada en Huancayo metropolotano 2017

Achachau Uribe, Edden Ronald 28 June 2018 (has links)
La presente tuvo como objetivo general la determinación de los factores de éxito de la Empresa Agroexportadora Ecoandino S.A.C. en la introducción del producto café a base de cebada torrada en Huancayo Metropolitano – 2017, por ello se ha realizado la discriminación de teorías para poder seleccionar los factores de éxito, para ello se utilizó la teoría de Kaplan y Norton, siendo el tipo de investigación básica, de un nivel de investigación descriptivo con un diseño descriptivo simple, que para poder recabar la información se utilizó como instrumento guía de focus group, cuestionario y una auditoria, logrando así determinar claramente la influencia de cada una de las dimensiones.
2

Two-Dimensional Bin Packing Problem with Guillotine Restrictions

Pietrobuoni, Enrico <1986> 10 April 2015 (has links)
This thesis, after presenting recent advances obtained for the two-dimensional bin packing problem, focuses on the case where guillotine restrictions are imposed. A mathematical characterization of non-guillotine patterns is provided and the relation between the solution value of the two-dimensional problem with guillotine restrictions and the two-dimensional problem unrestricted is being studied from a worst-case perspective. Finally it presents a new heuristic algorithm, for the two-dimensional problem with guillotine restrictions, based on partial enumeration, and computationally evaluates its performance on a large set of instances from the literature. Computational experiments show that the algorithm is able to produce proven optimal solutions for a large number of problems, and gives a tight approximation of the optimum in the remaining cases.
3

Models and Algorihtm for the Optimization of Real-World Routing and Logistics Problems

Novellani, Stefano <1985> 10 April 2015 (has links)
Logistics involves planning, managing, and organizing the flows of goods from the point of origin to the point of destination in order to meet some requirements. Logistics and transportation aspects are very important and represent a relevant costs for producing and shipping companies, but also for public administration and private citizens. The optimization of resources and the improvement in the organization of operations is crucial for all branches of logistics, from the operation management to the transportation. As we will have the chance to see in this work, optimization techniques, models, and algorithms represent important methods to solve the always new and more complex problems arising in different segments of logistics. Many operation management and transportation problems are related to the optimization class of problems called Vehicle Routing Problems (VRPs). In this work, we consider several real-world deterministic and stochastic problems that are included in the wide class of the VRPs, and we solve them by means of exact and heuristic methods. We treat three classes of real-world routing and logistics problems. We deal with one of the most important tactical problems that arises in the managing of the bike sharing systems, that is the Bike sharing Rebalancing Problem (BRP). We propose models and algorithms for real-world earthwork optimization problems. We describe the 3DP process and we highlight several optimization issues in 3DP. Among those, we define the problem related to the tool path definition in the 3DP process, the 3D Routing Problem (3DRP), which is a generalization of the arc routing problem. We present an ILP model and several heuristic algorithms to solve the 3DRP.
4

On the interplay of Mixed Integer Linear, Mixed Integer Nonlinear and Constraint Programming

Wiese, Sven <1985> 27 May 2016 (has links)
In this thesis we study selected topics in the field of Mixed Integer Programming (MIP), in particular Mixed Integer Linear and Nonlinear Programming (MI(N)LP). We set a focus on the influences of Constraint Programming (CP). First, we analyze Mathematical Programming approaches to water network optimization, a set of challenging optimization problems frequently modeled as non-convex MINLPs. We give detailed descriptions of many variants and survey solution approaches from the literature. We are particularly interested in MILP approximations and present a respective computational study for water network design problems. We analyze this approach by algorithmic considerations and highlight the importance of certain convex substructures in these non-convex MINLPs. We further derive valid inequalities for water network design problems exploiting these substructures. Then, we treat Mathematical Programming problems with indicator constraints, recalling their most popular reformulation techniques in MIP, leading to either big-M constraints or disjunctive programming techniques. The latter give rise to reformulations in higher-dimensional spaces, and we review special cases from the literature that allow to describe the projection on the original space of variables explicitly. We theoretically extend the respective results in two directions and conduct computational experiments. We then present an algorithm for MILPs with indicator constraints that incorporates elements of CP into MIP techniques, including computational results for the JobShopScheduling problem. Finally, we introduce an extension of the class of MILPs so that linear expressions are allowed to have non-contiguous domains. Inspired by CP, this permits to model holes in the domains of variables as a special case. For such problems, we extend the theory of split cuts and show two ways of separating them, namely as intersection and lift-and-project cuts, and present computational results. We further experiment with an exact algorithm for such problems, applied to the Traveling Salesman Problem with multiple time windows.
5

Models and Solutions of Resource Allocation Problems based on Integer Linear and Nonlinear Programming

Thomopulos, Dimitri <1987> 27 May 2016 (has links)
In this thesis we deal with two problems of resource allocation solved through a Mixed-Integer Linear Programming approach and a Mixed-Integer Nonlinear Chance Constraint Programming approach. In the first part we propose a framework to model general guillotine restrictions in two dimensional cutting problems formulated as Mixed-Integer Linear Programs (MILP). The modeling framework requires a pseudo-polynomial number of variables and constraints, which can be effectively enumerated for medium-size instances. Our modeling of general guillotine cuts is the first one that, once it is implemented within a state of-the-art MIP solver, can tackle instances of challenging size. Our objective is to propose a way of modeling general guillotine cuts via Mixed Integer Linear Programs (MILP), i.e., we do not limit the number of stages (restriction (ii)), nor impose the cuts to be restricted (restriction (iii)). We only ask the cuts to be guillotine ones (restriction (i)). We mainly concentrate our analysis on the Guillotine Two Dimensional Knapsack Problem (G2KP), for which a model, and an exact procedure able to significantly improve the computational performance, are given. In the second part we present a Branch-and-Cut algorithm for a class of Nonlinear Chance Constrained Mathematical Optimization Problems with a finite number of scenarios. This class corresponds to the problems that can be reformulated as Deterministic Convex Mixed-Integer Nonlinear Programming problems, but the size of the reformulation is large and quickly becomes impractical as the number of scenarios grows. We apply the Branch-and-Cut algorithm to the Mid-Term Hydro Scheduling Problem, for which we propose a chance-constrained formulation. A computational study using data from ten hydro plants in Greece shows that the proposed methodology solves instances orders of magnitude faster than applying a general-purpose solver for Convex Mixed-Integer Nonlinear Problems to the deterministic reformulation, and scales much better with the number of scenarios.
6

Mathematical Optimization for Routing and Logistic Problems

Gambella, Claudio <1988> 27 May 2016 (has links)
In this thesis, we focus on mathematical optimization models and algorithms for solving routing and logistic problems. The first contribution regards a path and mission planning problem, called Carrier-Vehicle Traveling Salesman Problem (CVTSP), for a system of heterogeneous vehicles. A Mixed-Integer Second Order Conic Programming (MISOCP) model and a Benders-like enumeration algorithm are presented for solving CVTSP. The second work concerns a class of routing problems, referred to as Interceptor Vehicle Routing Problems (IVRPs). They generalize VRPs in the sense that target points are allowed to move from their initial location according to a known motion. We present a novel MISOCP formulation and a Branch-and-Price algorithm based on a Lagrangian Relaxation of the vehicle-assignment constraints. Other two contributions focus on waste flow management problems: the former considers a deterministic setting in which a Mixed-Integer Linear Programming (MILP) formulation is used as a Decision Support System for a real-world waste operator, whereas the latter deals with the uncertainty of the waste generation amounts by means of Two-Stage Multiperiod Stochastic Mixed-Integer Programming formulations. Finally, we give an overview on the optimization challenges arising in electric car-sharing systems, both at strategic and tactical planning level.
7

Diagnóstico y mejora de procesos utilizando simulación de eventos discretos en una empresa de consumo masivo

Vilchez Marcos, Franko Rafael 17 August 2015 (has links)
El trabajo de investigación es una aplicación de simulación de eventos discretos, cuyo objetivo es incrementar la productividad y rentabilidad del proceso de elaboración y envasado de galletas de una empresa de consumo masivo. En el primer capítulo, se presentan las técnicas de muestreo aleatorio estratificado y diseño de experimentos fraccionados, las cuales se utilizan para analizar los datos de entrada y salida de los modelos de simulación respectivamente; así como también, dos casos de aplicación afines. En el segundo capítulo, se desarrolla la etapa de descripción y diagnóstico. En ella, utilizando los objetivos estratégicos de la compañía como criterios de evaluación, se elige a la tercera línea de elaboración y envasado de galletas como objeto de estudio. Asimismo, se identifican sus principales problemas, y se plantean y seleccionan las contramedidas adecuadas. En el tercer capítulo, se presenta la construcción del modelo de simulación base, su validación y la propuesta de mejora. Esta última consiste en diseñar un balance de línea eficiente para el proceso de envasado, utilizar nuevas y constantes velocidades de operación, previamente optimizadas, y sustituir dos operarios encargados de la alimentación manual de galletas de bajo nivel de experticia por unos estables; e invertir en la compra e implementación de dos nuevas envasadoras. De esta manera, se diseñan experimentos fraccionados y simulados con el fin de determinar la significancia de cada medida en la rentabilidad del proceso y sus niveles para maximizarla. Finalmente, se realiza la evaluación técnica y económica de la propuesta. En la primera, se demuestra que permite reducir el inventario de productos en proceso en 22.99% y 47.38% en el envasado primario y secundario respectivamente, disminuir el nivel de productos no conformes en 11.94%; así como también, evitar las continuas calibraciones y ajustes, y minimizar la duración y tiempo entre fallas imprevistas de equipos en las estaciones de trabajo donde se reemplazan las envasadoras primarias obsoletas. Mientras que, en la segunda, se comprueba la viabilidad económica del proyecto al obtener una Tasa Interna de Retorno (TIR) de 29.30% y un Valor Actual Neto (VAN) de S/. 1, 319,487.51 en un horizonte de cinco años. / Tesis
8

Análisis de la problemática de la gestión operativa de las contrataciones del Estado en la Sub Gerencia de Adquisiciones-Gerencia de Abastecimiento de ESSALUD

Rivera Minaya, Niskar Milenka 28 December 2018 (has links)
El presente Trabajo de Experiencia Profesional titulada “Análisis de la problemática de la gestión de las contrataciones del estado en la Sub Gerencia de Adquisiciones de la Gerencia de Abastecimiento de la Gerencia Central de Logística, - “EsSalud”, tiene como objetivo principal demostrar y evaluar las actividades que se realizan en las tres (03) fases de las contrataciones del estado.
9

Diseño de un Plan de Reingeniería de Procesos para el Área Operativa del Taller Automotriz E&E - Arequipa

Layme Ventura, Leonardo Teofilo 13 November 2018 (has links)
El objetivo principal del Trabajo de Investigación fue proponer el “Diseño de un Plan de Reingeniería de Procesos para el Área Operativa del Taller Automotriz E&E”, que pueda dar solución al problema de desorden y desorganización que existe en el área Operativa, la cual genera retrasos en el tiempo de entrega del servicio de mantenimiento, acarreando la insatisfacción de los clientes por la demora en el proceso. Esta mejora de ha evaluado bajo la Metodología 5s la cual nos permitirá optimizar los procesos al aplicar el enfoque de operaciones esbeltas.
10

LP-based heuristics for the Traveling Salesman Problem

Fortini, Matteo <1975> 29 May 2007 (has links)
No description available.

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