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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.
101

A study of the effects of the maintenance system at an open cast iron ore mine

Setzkorn, Kevin Anthony January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg 2017 / The study assesses the drilling, loading and trucking stages of the mining cycle of an iron ore mine situated in the Northern Cape province of South Africa for the period of 1 January to 30 June 2011. The purpose of this study is to investigate the effect of increasing reliability and maintainability of mining equipment in an effort to increase throughput of iron ore. The data processing indicated that both availability and utilisation are contributing to the sub-optimal performance of the mine. Data regarding reliability (MTBF), maintainability (MTTR), planned and unplanned maintenance was analysed, and this provided input for the simulation model. The intention of the simulation model is to simulate scenarios of proposed improvement in MTBF and MTTR through increasing planned maintenance activities. A simulation model provides insight regarding where to invest in interventions. It is determined that the drilling equipment is the problem area. / MT2018
102

Sustentabilidade empresarial: proposta para evidencia????o do resultado ambiental decorrente da internaliza????o dos gastos com a coleta, tratamento e destina????o final do produto aos custos da produ????o

Valim, Gilson Giungi 02 October 2014 (has links)
Made available in DSpace on 2015-12-03T18:35:31Z (GMT). No. of bitstreams: 1 Gilson_Giungi_Valim.pdf: 1562068 bytes, checksum: 22410dd362e720f1bf0d945cb147b989 (MD5) Previous issue date: 2014-10-02 / Nowadays, the environmental issue is a major and key challenge being faced by humanity, which requires a revision of the current model of development, the traditional concept of production. In this context, the purpose of this research was to determine, measure and evidence the result of the internalisation of costs with the collection, treatment and disposal of the product to the production costs of a multinational manufacturer of computer peripherals, based in S??o Paulo city, concerning the practices of the environment management adopted and their potential to mitigate the effects of environmental degradation, resulting from their productive activity. To do so, a descriptive and quantitative research was conducted. And data was collected through document analysis. It was verified that the physical composition of solid waste collected in 2013 totallized 1.068.317 sub product kilos. The cost of the the internalisation of costs with the collection, treatment and environmentally correct disposal of the product totalized, R$ 867.796,14. Concerning the environmental result, the company obtained a revenue of R$ 781.016,53, with a cost of R$ 867.796,14, resulting in a loss of R$ 86.779,61. Regarding the management practices of solid waste (collection, cleaning and treatment of products for selling), it was possible to state that the company obtained in 2013 a revenue of R$ 1.279.122,11 with a cost of R$ 867.796,14 and a social revenue of 411.325,97, totally internalized by the company that treats solid waste. Concerning environmental results, the company obtained a revenue of R$ 781.016,52, with an avoided raw material cost of R$ 9.188.185,51, in case it did not recycle and remanufacture 902.289 kilos of solid waste. Regarding total revenue, the company obtained R$ 323.161.281,13, with a cost of R$ 260.588.186,00 and a gross profit of R$71.349.796,00. If all these actions were not implemented by the company investigated, its costs would have raised in R$ 9.188.185,51, reducing its gross profit to R$ 62.572.936,00 in 2013. It means that the company did not generate negative externalities of 1.413.552 kilos of solid waste, obtaining an economic, social and environmental performance of R$ 8.776.859,54. It can be concluded that with the enhancement of accountancy costs espectrum, it was possible to outline a financial report with accountancy information capable of demonstrating social, environmental and economical-financial results of the company, regarding the policy adopted of solid waste management, with the potential of mitigating the effects of environmental degradation resulting from their productive activity. Therefore, methods capable of demonstrating the social and environmental results can help accountancy users, because not only do they need economical-financial information, but also social and environmental ones. / A quest??o do meio ambiente, na atualidade, ?? um dos grandes desafios a ser enfrentado pela humanidade, o que obriga a uma revis??o do modelo de desenvolvimento vigente, da tradicional forma de produ????o. Nesse cen??rio, esta pesquisa teve como objetivo geral determinar, mensurar e evidenciar o resultado ambiental decorrente da internaliza????o dos gastos com a coleta, o tratamento e a destina????o final do produto aos custos da produ????o de uma empresa multinacional. Essa empresa ?? fabricante de perif??ricos de inform??tica, sediada na cidade de S??o Paulo, em vista das pr??ticas de gest??o do meio ambiente que adota e de seu potencial para mitigar os efeitos da degrada????o ambiental decorrentes de sua atividade produtiva. Para tanto, foi realizada uma pesquisa descritiva quantitativa, e os dados foram coletados por an??lise documental. O estudo constatou que a composi????o f??sica dos res??duos s??lidos coletados em 2013 somou um volume de 1.413.552 kilos de subprodutos. O custo da internaliza????o dos gastos com a coleta, o tratamento e a destina????o final ambientalmente correta dos produtos totalizou R$ 867.796,14. No que concerne ao resultado ambiental, a empresa obteve uma receita de R$ 781.016,53, com custo de R$ 867.796,14, gerando um preju??zo de R$ 86.779,61. Quanto ?? pol??tica de gest??o dos res??duos s??lidos (coletar, limpar e tratar as pe??as e vender), foi poss??vel constatar que a empresa obteve, em 2013, uma receita social de R$ 1.279.122,11, com um custo de R$ 867.796,14 e um resultado social de R$ 411.325,97, integralmente reconhecidos pela empresa que realiza o tratamento dos res??duos s??lidos. No tocante ao resultado ambiental, a empresa obteve uma receita ambiental de R$ 781.016,52, com um custo evitado de mat??ria prima de R$ 9.188.185,51, caso a ind??stria n??o tivesse optado por reciclar e reindustrializar 902.289 kilos de res??duos s??lidos. Quanto ao resultado total, a empresa auferiu uma receita total de R$ 323.161.281,13, com um custo total de R$ 260.588.186,00 e um lucro bruto de R$71.349.796,00. Caso n??o tivesse adotado a pol??tica ambiental e social, seus custos seriam incrementados em R$ 9.188.185,51, reduzindo o seu lucro bruto para R$ 62.572.936,00 em 2013. Significa dizer que a empresa deixou de gerar externalidades negativas de 1.413.552 kilos de res??duos s??lidos, obtendo um desempenho econ??mico, social e ambiental no valor de R$ 8.776.859,54. Concluiu-se que, com a amplia????o do aspectro da contabilidade de custos, foi poss??vel a cria????o de um demonstrativo com informa????es cont??beis capazes de evidenciar os resultados social, ambiental e econ??mico-financeiro da empresa, em vista da pol??tica da gest??o dos res??duos s??lidos, com potencial para mitigar os efeitos da degrada????o ambiental decorrentes do processo produtivo. Ou seja, instrumentos que capazes de demonstrar o resultado social e ambiental atendem ??s necessidades dos usu??rios da contabilidade, que necessitam de informa????es n??o somente econ??mico-financeiras, mas, tamb??m, de cunho social e ambiental
103

Logística de resíduos da construção civil atendendo à resolução CONAMA 307. / The logistic of construction waste according to CONAMA 307 resolution.

Pucci, Ricardo Basile 18 May 2006 (has links)
O Resíduo de Construção e Demolição (RCD), devido ao seu volume, gera um alto impacto ambiental, social e econômico, trazendo assim a preocupação crescente sobre sua gestão. Essa gestão sempre foi responsabilidade do poder público. Porém, com a Resolução 307 do Conselho Nacional do Meio Ambiente (CONAMA), de 05 de julho de 2002, ela foi transferida para os geradores de resíduos, que devem segregar o resíduo em quatro classes diferentes e encaminhá-las para reciclagem ou deposição final. Assim, este trabalho propõe uma metodologia, baseada no enfoque sistêmico e em técnicas de pesquisa operacional, para tratar o problema de gestão de resíduos da Construção Civil, em conformidade com a Resolução CONAMA 307. A metodologia proposta compreende a elaboração de um Plano de Gestão de Resíduos que contemple a fase de projeto, minimizando a geração de resíduos; a segregação e o transporte do resíduo gerado dentro da obra; e a sua destinação final, incluíndo o controle da segregação e deposição do resíduo gerado. No trabalho são comparadas duas obras, uma onde não houve nenhuma forma de gestão sobre o resíduo e outra onde o Plano de Gestão proposto foi aplicado. Além disso, foi feito um modelo de simulação utilizando o programa de computador Arena 7.0, utilizado para avaliação do impacto do Plano em diversos cenários de geração, segrega ção e transporte dos resíduos. Como resultado do trabalho apresenta-se um Plano de Gestão de Resíduos que possui viabilidade econômica, social e ambiental, além de ser legalmente adequado, para ser usado por profissionais do setor público e privado no tratamento e gestão do resíduo gerado em suas obras. / The Construction and Demolition Waste (C&DW), because of its high volume, brings high environmental social and economical impacts, therefore the worries about its management has grown. This management has always been responsibility of the governments. But with the Resolution 307 of CONAMA (Brazilian Environmental National Council) of July 22nd, 2002, it was transferred to the waste producer, which has to segregate it in four different categories and ship it to be recycled or disposed properly. The proposal is to create a method, based on system approach and operations research, to deal with C&DW management, respecting Resolution 307 guidelines. The proposed method encompasses the creation of a Waste Management Plan, whichconsiders the aspects of the project, to minimize waste generation; the segregation and transport within the construction site; and the final destination of the waste, including a method to control its segregation and shipping. Two construction sites were considered, one that did not have any kind of waste management and one on which the Management Plan was implemented. In addition, it was developed a simulation model using the computer software Arena 7.0, to analyze the Plan under different scenarios of generation, segregation and shipping of construction waste. As a result, a Plan of C&DW Management was proposed and validated, which is economic, social and environmental feasible and legally adequate, to be used by public and private professionals when dealing with the C&DW of their constructions.
104

Modeling and simulation on the yard trailers deployment in the maritime container terminal

Unknown Date (has links)
In recent years, there has been an exponential increase in container volume shipment within intermodal transportation systems. Container terminals as part of the global port system represent important hubs within this intermodal transportation system. Thus, the need to improve the operational efficiency is the most important issue for container terminals from an economic standpoint. Moreover, intermodal transportation systems, ports and inland transport facilities should all be integrated into one coordinated plan. More specifically, a method to schedule different types of handling equipment in an integrated way within a container terminal is a popular topic for researchers. However, not many researchers have addresses this topic in relationship to the simulation aspect which will test feasible solutions under real container terminal environment parameters. In order to increase the efficiency of operations, the development of mathematical models and algorithms is critical in finding the best feasible solution. The objective of this study is to evaluate the feasible solution to find the proper number of Yard Trailers (YTs) with the minimal cost for the container terminals. This study uses the Dynamic YTs operation's method as a background for modeling. A mathematical model with various constraints related to the integrated operations among the different types of handling equipment is formulated. This model takes into consideration both serving time of quay cranes and yard cranes, and cost reduction strategies by decreasing use of YTs with the specific objective of minimum total cost including utilization of YTs and vessel berthing. In addition, a heuristic algorithm combined with Monte Carlo Method and Brute-Force Search are employed. The early Stage Technique of Monte Carlo method is proposed to generate vast random numbers to replicate simulation for real cases. / The Brute-Force Search is used for identifying all potential cases specific to the conditions of this study. Some preliminary numerical test results suggest that this method is good for use in conjunction with simulation of container terminal operation. The expected outcome of this research is a solution to obtain the proper number of YTs for transporting containers with a minimum cost; thus, improving the operational efficiency in a container terminal. / by Yueqiong Zhao. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
105

Influences from information technology on industry cycles : a case study in manufacturing industry.

Morecroft, John D. W January 1979 (has links)
Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Alfred P. Sloan School of Management. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY / Bibliography: p. 336-338. / Ph.D.
106

Data Fusion for Materials Location Estimation in Construction

Navabzadeh Razavi, Saiedeh 29 April 2010 (has links)
Effective automated tracking and locating of the thousands of materials on construction sites improves material distribution and project performance and thus has a significant positive impact on construction productivity. Many locating technologies and data sources have therefore been developed, and the deployment of a cost-effective, scalable, and easy-to-implement materials location sensing system at actual construction sites has very recently become both technically and economically feasible. However, considerable opportunity still exists to improve the accuracy, precision, and robustness of such systems. The quest for fundamental methods that can take advantage of the relative strengths of each individual technology and data source motivated this research, which has led to the development of new data fusion methods for improving materials location estimation. In this study a data fusion model is used to generate an integrated solution for the automated identification, location estimation, and relocation detection of construction materials. The developed model is a modified functional data fusion model. Particular attention is paid to noisy environments where low-cost RFID tags are attached to all materials, which are sometimes moved repeatedly around the site. A portion of the work focuses partly on relocation detection because it is closely coupled with location estimation and because it can be used to detect the multi-handling of materials, which is a key indicator of inefficiency. This research has successfully addressed the challenges of fusing data from multiple sources of information in a very noisy and dynamic environment. The results indicate potential for the proposed model to improve location estimation and movement detection as well as to automate the calculation of the incidence of multi-handling.
107

Data Fusion for Materials Location Estimation in Construction

Navabzadeh Razavi, Saiedeh 29 April 2010 (has links)
Effective automated tracking and locating of the thousands of materials on construction sites improves material distribution and project performance and thus has a significant positive impact on construction productivity. Many locating technologies and data sources have therefore been developed, and the deployment of a cost-effective, scalable, and easy-to-implement materials location sensing system at actual construction sites has very recently become both technically and economically feasible. However, considerable opportunity still exists to improve the accuracy, precision, and robustness of such systems. The quest for fundamental methods that can take advantage of the relative strengths of each individual technology and data source motivated this research, which has led to the development of new data fusion methods for improving materials location estimation. In this study a data fusion model is used to generate an integrated solution for the automated identification, location estimation, and relocation detection of construction materials. The developed model is a modified functional data fusion model. Particular attention is paid to noisy environments where low-cost RFID tags are attached to all materials, which are sometimes moved repeatedly around the site. A portion of the work focuses partly on relocation detection because it is closely coupled with location estimation and because it can be used to detect the multi-handling of materials, which is a key indicator of inefficiency. This research has successfully addressed the challenges of fusing data from multiple sources of information in a very noisy and dynamic environment. The results indicate potential for the proposed model to improve location estimation and movement detection as well as to automate the calculation of the incidence of multi-handling.
108

Logistische Entscheidungen und ihre Auswirkungen: Die Unternehmenssimulation LogisticPLUS / Logistical decisions and their effects: The Management Game LogisticPLUS

Eichhorn, Maximilian 15 December 2000 (has links)
No description available.
109

Priorização de inbound em centro de distribuição: estudo de caso em uma empresa de bens de consumo não duráveis / Inbound prioritization in distribution center: case study of a non-durable consumer goods company

Lopes, Karine Fasolin 16 July 2015 (has links)
Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-06T14:50:25Z No. of bitstreams: 1 LOPES_Karine Fasolin_2015.pdf: 7001137 bytes, checksum: e08df43645b4a8a2c78fc5aa9bcab779 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-06T14:50:33Z (GMT) No. of bitstreams: 1 LOPES_Karine Fasolin_2015.pdf: 7001137 bytes, checksum: e08df43645b4a8a2c78fc5aa9bcab779 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-06T14:50:40Z (GMT) No. of bitstreams: 1 LOPES_Karine Fasolin_2015.pdf: 7001137 bytes, checksum: e08df43645b4a8a2c78fc5aa9bcab779 (MD5) / Made available in DSpace on 2017-01-06T14:50:48Z (GMT). No. of bitstreams: 1 LOPES_Karine Fasolin_2015.pdf: 7001137 bytes, checksum: e08df43645b4a8a2c78fc5aa9bcab779 (MD5) Previous issue date: 2015-07-16 / Não recebi financiamento / Companies in the distribution sector of non-durable consumer goods in Brazil suffer with the sales' concentration at the end of the marketing period, i.e., when a large amount of deliveries to customers occur in the last days of the month. This phenomenon can directly affect the company's costs as well as the level of service for lack of available products. Quite common scenarios that happen in distribution centers (DC) in this period are vehicles waiting to unload and the lack of products for delivery orders – it can also happen that the missing products are queued on hold in the trucks, waiting to be received. Considering the operations in distribution centers during this period is focused on the outbound of products, just some docks are available for unload. Based on this, the key issue is to determine which trucks must enter first at the docks to unload considering the necessity of products for the shipping operations and also the costs involved in this choice. Hence, the main objective of this study is firstly to propose a Mathematical Programming model to assists in prioritizing incoming vehicles, i.e., to determine which trucks must unload only considering the lack of product. Also, evaluate an extension of this model to minimize the costs of prioritization of vehicles, considering the lack of products, extra hours and demurrage per vehicle not received. The model is based on problems of vehicles assignation such as the gate assignments in airports and ships allocation in ports. Nevertheless, taking into consideration a distribution center of a company on the non-durable Consumer Goods Sector. The model was solved using the commercial package GAMS/CPLEX and the results were compared with the plans practiced by the company obtaining an average improvement for minimizing the lack of products of 37.1 % and 31% of minimizing costs. Furthermore, in order to verify the model fitness, some random instances were also performed. The model results generated adequate solutions to the problem, showing that the model is a viable tool for the inbound prioritizing of products. / As empresas do setor de bens de consumo não duráveis no Brasil sofrem com uma grande concentração das vendas no final do período de comercialização, isto é, uma grande quantidade de entregas para clientes ocorre nos últimos dias do mês. Este fenômeno pode intervir diretamente nos custos da empresa, assim como no nível de serviço por falta de produtos disponíveis. Situações bastante comuns que ocorrem em Centros de Distribuição (CD) neste período são veículos aguardando para descarregar e a falta de produtos para entrega de pedidos, sendo que pode acontecer de os produtos faltantes estarem na fila de espera, em veículos, aguardando para serem recebidos. Como as operações nos centros de distribuição neste período trabalham focadas na expedição de produtos, apenas algumas docas estão disponíveis para descarregar. Desta forma, a questão chave é determinar quais carretas devem entrar nas docas para descarregar considerando a necessidade de produto para a operação de expedição, o que interfere diretamente no nível de serviço aos clientes e também nos custos envolvidos nesta escolha, por exemplo, custos relacionados à perda de vendas e neste caso, pode envolver a decisão de pagamentos de docas extras. Portanto, o objetivo deste trabalho é, primeiramente, propor um modelo de programação matemática para auxiliar na priorização de recebimento de veículos, ou seja, determinar quais veículos devem descarregar considerando apenas a falta de produto e, avaliar uma extensão deste modelo para minimizar os custos da priorização de veículos, considerando a falta dos produtos, as horas extras e a taxa de estadia cobrada por veículo não descarregado. Os modelos são baseados em problemas de alocação de veículos, tais como alocação de portões em aeroportos e alocação de navios em portos, mas considera o problema de recebimento em um centro de distribuição de uma empresa do setor de bens de consumo não duráveis. Os modelos foram resolvidos utilizando o pacote comercial GAMS/CPLEX e os resultados obtidos foram comparados com os planos praticados pela empresa obtendo uma melhora média para a minimização da falta de 37,1% e minimização de custos de 31%. Além disso, a fim de verificar a adequação do modelo, algumas instâncias aleatórias também foram executadas. Os resultados do modelo geraram soluções adequadas para o problema, mostrando que o modelo é uma ferramenta viável para a priorização de recebimento de produtos.
110

Desenvolvimento de metodologias utilizadas nas áreas de salvaguardas e forense nuclear baseadas na técnica LA-HR-ICP-MS / Development of methodologies used in Safeguards and Nuclear Forensics based on LA-HR-ICP-MS technique.

MARIN, RAFAEL C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:16Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:15Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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