• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Development of New Network-Level Optimization Model for Salem District Pavement Maintenance Programming

Akyildiz, Sercan 22 October 2008 (has links)
Infrastructure systems are critical to sustaining and improving economical growth. Poor condition of infrastructure systems results in lost productivity and reduces the quality of life. Today's global economy forces governments to sustain and renew infrastructure systems already in place in order to remain competitive and productive (GAO, 2008). Therefore, civil engineers and policymakers have been quite interested in the overall quality of the highways and bridges throughout the US (Miller, 2007). Transportation networks are essential parts of the Nation's infrastructure systems. Deterioration due to age and use is the main threat to the level of service observed in surface transportation networks. Thus, highway agencies throughout the United States strive to maintain, repair and renew transportation systems already in place (Miller, 2007). A recent disaster, the collapse of the Minneapolis I-35 W Bridge, once again revealed the importance of infrastructure preservation programs and resulted in debates as to how state departments of transportation (DOTs) should and can preserve the existing infrastructure systems. Therefore, it is essential to establish effective maintenance programs to preserve aging infrastructure systems. The major challenge facing the state highway maintenance managers today is to preserve the road networks at an acceptable level of serviceability subject to the stringent yearly maintenance and rehabilitation (M&R) budgets. Maintenance managers must allocate such limited budgets among competing alternatives, which makes the situation even more challenging. Insufficient use of available smart decision-making tools impedes eliciting effective and efficient maintenance programs. Hence, this thesis presents the development and implementation of a network-level pavement maintenance optimization model which can be used by maintenance managers as a decision-making tool to address the maintenance budget allocation issue. The network-level optimization model is established with the application of the Linear Programming algorithm and is subject to budget constraints and the agencies' pavement performance goals in terms of total lane-miles in each pavement condition state. This tool is developed with Microsoft Office Excel. The tool can compute the optimal amount of investment for each pavement treatment type in a given funding period. Thus, the model enables maintenance managers in highway agencies to develop alternative network-level pavement maintenance strategies through an automated and optimized process rather than using what-if analysis. / Master of Science
2

Semantics-based change-merging of abstract data types

Chadha, Vineet. January 2002 (has links)
Thesis (M.S.)--Mississippi State University. Department of Computer Science. / Title from title screen. Includes bibliographical references.
3

Análise da aplicação de modelos de otimização linear na solução de problemas de dimensionamento de lotes e sequenciamento da produção de bebidas. / Analysis of the application of linear optimization models to solution lot sizing and scheduling problems in beverage industry.

Noble Ramos, Victor Mario 24 November 2017 (has links)
Submitted by Victor Mario Noble Ramos (vicmanr90@gmail.com) on 2017-12-01T18:27:41Z No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-12-04T12:40:00Z (GMT) No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-12-04T12:40:12Z (GMT) No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) / Made available in DSpace on 2017-12-04T12:40:54Z (GMT). No. of bitstreams: 2 TextoFinalDissertationVicman-PosDefesa.pdf: 37720288 bytes, checksum: e8e3336733bc8151bd42eab9118f2b2a (MD5) CartaTextoFinal.pdf: 241030 bytes, checksum: 8c46be374e02fb08ecd2b0f6ac30a27b (MD5) Previous issue date: 2017-11-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This dissertation adresses the general integrated lot sizing and scheduling problem for non-alcoholic beverage production with synchronization between stages and operating time windows for scheduling preventive maintenances. The problem is characterized by having two interdependent synchronized stages. In the first stage, machines (tanks) can supply several filling lines at the same time in the second stage, where the final items are packed. Production sequence-dependent times and costs exist. The review of the related literature indicates that existing models refer, generally, to particular cases of the general problem adressed here, the most common cases are the dedication of tanks to the lines, and disregarding the perishability of syrups and the possibility of scheduling preventive maintenances. A mathematical model for the general problem, called SMMRPM, has been proposed and applied in several instances to show the adherence and flexibility of the model to represent practical cases that can be found in reality. For the case of the dedication of tanks to lines, the model was compared with the dedicated model F1 (FERREIRA et al, 2012). The results indicate that the SMMRPM model is flexible and adherent to represent practical scenarios in which other models are not applicable, for example the possibility of scheduling preventive maintenance and consideration of perishability are differential of the proposal. In the plans obtained, it was shown that it is important to include these considerations that significantly affect the productive plans. In the case of dedication, compared to the dedicated model, the formulation SMMRPM achieves production plans, on average, 52.63 \% less costly than F1. / Nesta dissertação de mestrado é pesquisado o problema geral integrado de dimensionamento e sequenciamento de lotes da produção de bebidas não alcoólicas com sincronia ente os estágios e janelas de tempo de operação para programação de manutenções preventivas. O problema é caracterizado por ter dois estágios sincronizados e dependentes entre si. As máquinas do primeiro estágio (tanques) podem suprir ao mesmo tempo várias linhas de envase no segundo estágio, onde são envasados os itens finais. Existem tempos e custos de setup dependentes da sequência de produção. A revisão da literatura relacionada indica que modelos existentes referem-se, em geral, a casos particulares do problema geral aqui tratado, sendo que os casos mais comuns são a dedicação de tanques à linhas, e desconsideração da perecibilidade dos xaropes e da possibilidade de programar manutenções preventivas. Foi proposto um modelo matemático para o problema geral, denominado SMMRPM, e aplicado em diversas instâncias a fim de mostrar a aderência e a flexibilidade do modelo para representar casos práticos que podem ser achados na realidade. Para o caso da dedicação de tanques a linhas, o modelo foi comparado com o modelo dedicado F1 (FERREIRA et al, 2012). Os resultados indicam que o modelo SMMRPM é flexível e aderente para representar cenários práticos em que outros modelos não são aplicáveis, por exemplo a possibilidade de programar manutenções preventivas e consideração da perecibilidade são diferenciais da proposta. Nos planos obtidos foi mostrada a importância da inclusão destas considerações que afetam significativamente os planos produtivos. No caso da dedicação, comparado com o modelo dedicado, a formulação SMMRPM consegue planos de produção, em média, 52.63 % menos custosos que o F1. / Demanda Social

Page generated in 0.1094 seconds