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Secondary markets have not historically possessed the characteristics necessary for market power to emerge, or effective product differentiation to be implemented. The potential effects of these characteristics on primary – secondary market interaction is generally not considered. The law of one price is expected to hold in secondary markets. By applying the hedonic technique to producer theory, and integrating the durability of the product directly into the profit maximizing conditions, potential differences in implicit prices between customer segments in the used bucket truck market are estimated. Applying weighted least squares to the hedonic equation, parameters were estimated to indicate whether differences in hedonic prices exist between customer segments in the secondary, utility construction equipment market. The hedonic approach accounted for differences in price due to physical characteristics, while underlying supply and demand conditions were accounted for using indicator variables for time. Estimated differences in the effects of physical characteristics on price, between industries, were identified using interaction terms. Results of the econometric estimation indicate that differences in physical product characteristics do not fully account for differences in price between customer segments in the secondary bucket truck market. If the law of one price can be violated in a secondary market, this could indicate market power. Future research on primary – secondary market interaction should consider the potential effects, if such market power does indeed exist.

Transport costs can account for a significant portion of the total production costs in an agricultural system. In order to ensure maximum efficiency of a transport operation, the transport manager is required to select a suitable vehicle and choose the best route. This is a complex process as vehicles should not be selected based solely on lowest capital cost, but with several variables taken into account. In order to determine an optimal haulage system and to aid the decision making process, a computer model called SimTrans has been developed. SimTrans simulates a haulage vehicle travelling on any given route under normal vehicle operating conditions. The model produces a set of simulated vehicle performance results and a summary of trip details. The vehicle input parameters and route details can be modified to enable the user to simulate different vehicle configurations on alternate routes. The SimTrans model was used in this research project as it provides a comprehensive output of simulated results. However, under certain conditions there is variance between actual and the simulated vehicle performance in SimTrans, particularly with the gear selection routines. The primary objective of this research was to refine, calibrate and validate the current SimTrans model. An initial investigation focused on diesel engine management systems for heavy-duty commercial vehicles and how these systems affect a vehicle's performance. This investigation was aimed at gaining an understanding of how performance data could be gathered directly from the onboard vehicle electronics of a haulage vehicle. A data logging system was developed to measure and record certain operating parameters of a haulage vehicle during operation. The system was installed on a Mercedes Benz 2637 and the vehicle was driven on two alternative routes between the Eston Sugar Mill and a loading zone near Mid-Illovo. The Mercedes Benz 2637 used for the vehicle tests was simulated in SimTrans using identical operating conditions of route and speed limits. By comparing the observed and simulated data sets, errors particularly with gear selection routines were identified. The SimTrans model was modified such that these errors were corrected and a new gear skipping routine was added. The modified SimTrans model was validated through a comparison of a new set of simulated results with the observed data. The modified model showed significant improvement in simulation accuracy over the previous version of SimTrans. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2007.

Thesis (M.S.) -- University of Tennessee, Knoxville, 2005. / Title from title page screen (viewed on June 30, 2005). Thesis advisor: J. Harold Deatherage. Document formatted into pages (vii, 43 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 41-42).

Thesis (M.C.E.)--University of Delaware, 2006. / Principal faculty advisor: Dennis R. Mertz, Dept. of Civil and Environmental Engineering. Includes bibliographical references.

Thesis (Ph. D.)--Texas A&M University, 2005. / Includes bibliographical references (leaves 128-130). Also available online.

Η παρούσα εργασία εισάγει τον αναγνώστη στο φαινόμενο των δασικών πυρκαγιών. Στο παραπάνω πλαίσιο, καθοριστικός παράγοντας για την άμεση κατάσβεση των δασικών πυρκαγιών είναι η σωστή χωροθέτηση των πυροσβεστικών οχημάτων. Η βέλτιστη χωροθέτηση στο υπάρχων πρόβλημα επιτυγχάνεται μέσω των μοντέλων κάλυψης. Εφαρμόζονται και συγκρίνονται τα αποτελέσματα με την υπάρχουσα κάλυψη που παρέχεται από την υφιστάμενη χωροθέτηση των περιπολιών από την Πυροσβεστική Υπηρεσία στο νομό Αχαΐας. / -

Scania has identified a problem among certain costumers in very dusty environments. The air filters for their truck’s climate system need extensive maintenance, replacement or manual cleaning, because of dust frequently loading up the filters. In this thesis the problem has been analyzed in order to find a solution. The process was initiated by the usage of the black box method, where needed transformations were found, resulting in three needed technical systems. Thereafter, brainstorming was used to find concepts for each technical system. Concepts were compared and ranked against each other. For the most critical of the three systems, the cleaning action, prototypes were built of the four highest ranked concepts. These prototypes were then used to compare the performance between the concepts. The selected filter cleaning device consists of a method to analyze filter blockage, alert the driver when cleaning is needed and a system to clean the filter for the Scania climate system. The system consists of a pressure sensor used to measuring filter blockage, an air pulse system which cleans the filter and a controller unit to control the cleaning cycle and to inform the driver. The air pulse system has two main parts, a pulse valve and an air tank. The pulse valve is used for releasing the air accumulated in the air tank. The complete system is supplied with 8.5 bar from the internal air pressure system in the truck and a 24 V power supply, also located in the truck. A suggestion on how a final implementation can be done has been developed, with a minimized number of variants and modifications of parts already in production. A proof of concept was built and mounted in a truck to validate the complete system. Numbers on cleaning performance and sound levels have been produced. The proof of concept manages to remove the restriction created from dust by approximately 50 %. Aside from developing a suitable filter cleaning device, figures on when the filter needs to be cleaned have been identified. To keep a good working environment within the cab a pressure drop over the filter of 936 Pa is recommended as a point of cleaning. This is to maintain the needed airflow of at least 123 m3/h with two persons seated in the cab to not exceed regulated levels of CO2 within the truck cab.

O preço atual do minério de ferro obrigou as empresas a reduzirem os custos operacionais na fase mina. O carregamento e transporte de materiais com utilização de escavadeiras e caminhões grande porte representam grande parcela do custo total, particularmente com pneus, diesel, manutenção e mão de obra. Metas de movimentação anual são divididas durante os meses e as condições climáticas podem influenciar na produtividade e desempenho dos equipamentos. O banco de dados da movimentação mensal está condicionado com a capacidade de cada caminhão. Cada frota possui o payload característico e este representa a capacidade de transporte, sendo o valor da massa transportada o único parâmetro extraído em cada ciclo, sem considerar o posicionamento do material sobre a caçamba dos equipamentos. Forças de cisalhamento e torção são aplicadas constantemente no chassi e pneus dos caminhões e, quando as cargas estão descentralizadas, potencializam estes eventos. O transporte de cargas descentralizadas agride os pneus diminuindo a vida útil causando danos como deslocamento da banda de rodagem e separação do flanco. Este trabalho teve como objetivo diminuir as ocorrências de cargas descentralizadas e os custos operacionais. Para incrementar o posicionamento do material sobre as caçambas, a telemetria foi a ferramenta utilizada. Análises de pressões de suspensões indicam o posicionamento das cargas e através desses valores foi criado um banco de dados. Este banco de dados pode indicar qual operador de carga precisa de reciclagem, contribuindo para a redução de cargas descentralizadas e custos, uma vez que cargas deste perfil sucateiam precocemente pneus e suspensões. O estudo foi realizado em Itabira, em uma mina de minério de ferro a céu aberto. A metodologia comprovou ser capaz diminuir as ocorrências de cargas descentralizadas assim como aumentar a vida útil de pneus. Uma possível economia foi apresentada para ano de 2014, período em que a média das horas trabalhadas de pneus ficou abaixo da meta aumentando os custos fase mina. / The actual iron ore price forces the companies to reduce costs in all production steps of the mining operation. Loading and hauling materials using shovel-truck system represents the highest mining costs, particularly tires, diesel, maintenance and workforce. Annual goals of materials movement are split by months were weather conditions can affect productivity and performance of the fleet. The data file of the monthly material movement is based on the scale of each truck. Every fleet has a payload and it represents the capacity of hauling, being the value of loading a unique input extracted in each duty cycle, without taking into account the position of the material over the truck’s dump. Shear forces and torsion are applied all time at the frames trucks and, when the truckloads are unbalanced, increases the forces over the frame and tires. Transport unbalanced truckloads into long distances attack the tires and decrease its end of life, causing damages like displacement of tread and flank separation. The objective of this study is to propose a methodology to decrease unbalanced truck loads reducing the mining costs. In this mission of incorporating a material position on the truck´s dump, the telemetry was taking into consideration. The analysis of the suspension pressures data values shows the truckloads positions and with this data was created a databank. This databank indicates that the operators need truck load training to reduce unbalanced loads and truck costs in the mining operation, since unbalanced loads leads to early tires and suspensions scrap. The case study was carried out at Itabira Iron Ore Mine Complex, Brazil. This methodology was able to reduce the number of unbalanced truck loads as well as the tires life was increased. An economic saving estimate is presented based on 2014 scrapped tires data bank, in this year the tires life cycle was underneath, burdening operational costs.

O motivo da dissertação “Desenvolvimento de um Modelo de Dimensionamento de Equipamentos de Escavação e de Transporte” surgiu da necessidade de apoiar no processo de decisão de dimensionamento dos principais equipamentos de mineração. Este trabalho apresenta um modelo simples e direto para dimensionar os equipamentos principais de mineração (escavadeiras e caminhões) através de uma rotina criada denominada EXCEsimulator, concebido para o cálculo da capacidade das caçambas das escavadeiras, do número dos equipamentos de escavação e de transporte, bem como os tempos de espera das unidades de transporte em carregar. Para tal, definem-se os parâmetros de produtividade e caraterísticas dos equipamentos; calcula-se aplicando um modelo determinístico de produção; e faz-se o levantamento de equipamentos existentes no mercado, reunindo as suas características e serviços prestados pelos representantes ou fabricantes das marcas. Para demostrar a funcionalidade do modelo desenvolvido, o presente trabalho demonstrou, através de um estudo de caso, o dimensionamento de uma frota de carregamento e transporte para uma mineração a céu aberto utilizando indicadores de produção, e uma comparação entre o uso de equipamentos de pequeno e grande porte no aspeto da demanda de equipamento. O estudo foi desenvolvido a partir de uma empresa de mineração hipotética baseada em dados realista. O modelo desenvolvido é aplicável a qualquer tipo de equipamento de escavação e de transporte, independente do seu porte e capacidade de produção. Como conclusão, pretende-se com esta dissertação fornecer uma ferramenta útil para o apoio à decisão de dimensionamento de equipamentos e frotas de escavação e de transporte capaz de suprir a necessidade de uma consulta de mercado. / The reason for the dissertation "Development of an Estimating Model for Excavation and Transport Equipment" arose from the need to support the decision-making process for the size of the main mining equipment. This work presents a simple and direct model for sizing the main mining equipment (excavators and trucks) through a routine created called EXCEsimulator, designed to calculate the capacity of excavator buckets, number of excavation and transport equipment, and As the waiting times of the transport units on loading. For this, the parameters of productivity and characteristics of the equipment are defined; Is calculated by applying a deterministic model of production; And it is made the survey of existing equipment in the market, gathering its characteristics and services provided by the representatives or manufacturers of the brands. To demonstrate the functionality of the developed model, the present study demonstrated, through a case study, the design of a loading and transport fleet for open pit mining using production indicators, and a comparison between the use of small equipment And large in the aspect of equipment demand. The study was developed from a hypothetical mining company based on realistic data. The developed model is applicable to any type of excavation and transportation equipment, regardless of its size and production capacity. In conclusion, it is intended with this dissertation to provide a useful tool to support the decision on sizing equipment and excavation and transport fleets capable of supplying the need for a market consultation.