Competição e regulamentação no transporte de passageiros: Um estúdio no transporte rodoviário intermunicipal

The objective of this research is the verification of the competition in the intecity market, after the entrance of new competitors (vans and microbus) regulated and clandestine. For verification of this new view was effected one research of documentary character for the knowledge of the regulation and exploratory character of the system Natal - territory of the Seridó, for thus in making will know this problematic, well as its characteristics, attractivenesses and development of the territory of the Seridó, and its link with the Capital (Natal). Later, through a descriptive exploratory research of the type survey with the passengers to know as these are being taken care and its satisfaction in relation to the regulated companies. With the drivers if focus effected one group, and with the staff of the of sale ticket a research survey, aiming at to know the strategies used for the only company of bus that takes care of the territory of the Seridó, the implantation of these and the consequence of the user. In accordance with the generic tipologia of Porter and its strategies, were perceived that the bus company adopted the strategy of price leadership being competitive, using to advantage its bigger space in the market, already vans and the microbuses with its limited participation bet in a strategy of "differentiation" in its service, effecting faster trips and in the strategy of "approach" we find the not regulated services earn the service to the taste of the user

Modelo de gerenciamento de estoques de peças de reposição para empresas de transporte urbano de passageiros

This work searches to offer a model to improve spare parts stock management for companies of urban passenger transport by bus, with the consequent progress in their maintenance management. Also known as MRO items (Maintenance, Repair and Operations), these spare parts, according their consumption and demand features, cost, criticity to operation, lead-time, quantity of suppliers, among other parameters, shouldn´t have managed their inventory like normal production items (work in process e final products), that because their features, are managed by more predictable models based, for example, in economic order quantity. In the case specifically of companies of urban passenger transport by bus, items MRO have significant importance in their assets and a bad management of these inventories can cause serious losses to company, leading it even bankrupticy business, in more severe situations which missing spare part provokes vehicles shutdown indefinitely. Given slight attention to the issue, which translates in little literature available about it when compared to that literature about normal items stocks, and due the fact that MRO items be critical to bus urban transport of passengers companies´, it is necessary, so, deepen in this theme searching to give technical and scientific subsidies to companies that work, in many times, empirically, with these so decisive inputs to their business. As a typical portfolio problem, in which there are n items, separated into critical and noncritical, while competing for the same resource, it was developed a new algorithm to aid in a better inventory management of spare parts used only in corrective maintenance (whose failures are unpredictable and random), by analyzing the cost-benefit ratio, which compares the level of service versus cost of each item. The model was tested in a company of urban passenger transport by bus from the city of Natal, who anonymously provided their real data to application in this work

Avaliação de desempenho em mercados reguladores de transporte urbano por ônibus :proposição de um modelo aplicável ao caso de Natal

Increased competition in the market of urban transport, characteristic of the Brazilian cities from years 90, has required actions of the managing agencies to ensure the universality of service, enhancing efficiency and consumer welfare. It grows in the Brazilian municipalities, the need to adopt a systematic performance evaluation in terms of management system of indicators and targets appropriate to the regulatory context, which has the purpose of evaluating the accomplishment and compliance by dealers, of the services granted during the contract period, marked by increasingly long periods. The introduction of an index operational performance in permission contracts/concession in urban buses is intended to establish a regulatory performance, giving the contract a pro-competitive feature and to allow the managing agency the systematic and continuous monitoring of the performance of the delegated service to avoid major deviations from desired performance. A performance assessment model of public transportation companies by bus, and applicable to the case of Natal is proposed. Sought to add the particularities found in the transport system in order to assess the performance of enterprises, contribute to improving the service quality to the population and enable decision-makers a detailed knowledge of the behavior of the licensees

Otimização de escalas de serviço de tripulações estudo de caso em uma empresa de transporte urbano na região metropolitana de Natal/RN

This work aims to "build" rostering urban bus crews to minimize the cost of overtime. For this purpose a mathematical model was developed based on case study in an urban transport company in the metropolitan region of Natal. This problem is usually known in the literature as the Crew Scheduling Problem (CSP) and classified as NP-hard. The mathematical programming takes into account constraints such as: completion of all trips, daily and maximum allowable range of home and / or food. We used the Xpress-MP software to implement and validate the proposed model. For the tested instances the application of the model allowed a reduction in overtime from 38% to 84%

Algoritmos de otimização para decisões de localização de facilidades e distribuição em sistemas multiníveis de transporte rodoviário de carga

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Um Estudo de Politicas e Práticas do uso do GNV no transporte público urbano do Brasil

The use of Natural Gas Vehicle has had a fast increase lately. However, in order to have a continuous success this Program needs to develop converting devices of Otto-cycle engines, gasoline or alcohol, to the use of NGV (Natural Gas Vehicle) that presents low cost, maintaining the same original development of the vehicle and low level of emissions, considering the PROCONVE rules. Due to the need to diversify the matrix in order to avoid energetic dependence and due to strict pollution control, it has increased in the Brazilian market the number of vehicles converted to the use of NGV. The recent regulation of the PROCONVE, determining that the converted engines with kits should be submitted to emission testing, comes to reinforce the necessity of the proposed development. Therefore, if we can obtain kits with the characteristics already described, we can reach a major trust in the market and obtain an increase acceptance of the vehicle conversion for NGV. The use of natural gas as vehicle fuel presents several advantages in relation to liquid fuels. It is a vehicle fuel with fewer indexes of emissions when compared to diesel; their combustion gases are less harmful, with a major level of safety than liquid fuels and the market price is quite competitive. The preoccupation that emerges, and the motivation of this project, is to know which are the main justifications for such technology, well accepted in other countries, with a low index or emission, with a high level of safety, where its maintenance becomes low, reminding that for this it is necessary that this technology has to be used properly, and once available in the market will not motivate interest in the urban transportation companies in Brazil, in research centers in general. Therefore this project exists to show the society in a general way the current vision of the main governmental factors, of the national research centers and of the private companies concerning the use of natural gas vehicles in urban transport vehicles, in order to give a major reliability to the population as well as to motivate national market competitiveness with a low cost and reliable product and to enrich the national technology

Uma aplicação de análise de decisão com o método AHP Processo de hierarquia analítica: um estudo sobre adoção de Sistema eletrônico de cobrança no Transporte público urbano

This thesis carries through an application of Analysis of Multicriterion Decision with use of the method of Analytical Hierarchy Process (AHP) in the problematic one of taking of decision of the adoption of electronic collecting in the system of urban transport in the country, a subject that has been controversial. A modeling of criteria and alternatives is carried through and applied a questionnaire based on method AHP the excellent actors in the system of urban transport - Leading of the Managing Agency Public Municipal theatre of Urban Transports, Controller of Company of Bus, Controller of Labor union, Controller of Union of Companies, Communitarian Leader. The considered alternatives were: the maintenance of the current state with collectors, the implementation of electronic collection without collectors, and the implementation of electronic collection with collectors. The used criteria were: job, impact in the fare, control of the system, easiness of use, information. The study was carried through in the city of Natal, RN, where if the adoption of electronic collection argues and where this implementation in some bus lines between Natal and Parnamirim exists, city that integrates the region of the great Natal. The main results of the method evidence in a dimension, the viability of use of method AHP with questionnaire by means of validation of the judgments with analysis of variance beyond proper the normal mechanisms of analysis of consistency to the method, and in another one, the contribution of the analysis boarding multicriterion to become the judgments more clearly. The main results of the analysis help to show that although to models of criteria and distinct judgments of the actors, the method evidenced that it has inclination the adoption of the electronic collection on the current situation, even so with divergences between the maintenance or not of the collector. The research points to the possibility of accomplishment of the application of the AHP in successive rounds of judgments

Desenvolvimento de uma cadeira de rodas robótica para transporte de portador de necessidades especiais

The objective of the dissertation was the realization of kinematic modeling of a robotic wheelchair using virtual chains, allowing the wheelchair modeling as a set of robotic manipulator arms forming a cooperative parallel kinematic chain. This document presents the development of a robotic wheelchair to transport people with special needs who overcomes obstacles like a street curb and barriers to accessibility in streets and avenues, including the study of assistive technology, parallel architecture, kinematics modeling, construction and assembly of the prototype robot with the completion of a checklist of problems and barriers to accessibility in several pathways, based on rules, ordinances and existing laws. As a result, simulations were performed on the chair in various states of operation to accomplish the task of going up and down stair with different measures, making the proportional control based on kinematics. To verify the simulated results we developed a prototype robotic wheelchair. This project was developed to provide a better quality of life for people with disabilities

Desenvolvimento e caracterização de nanocompósito de resina epóxi com nanopartículas de sílica para revestimento de dutos para transporte de petróleo

The use of polymer based coatings is a promising approach to reduce the corrosion problem in carbon steel pipes used for the transport of oil and gas in the oil industry. However, conventional polymer coatings offer limited properties, which often cannot meet design requirements for this type of application, particularly in regard to use temperature and wear resistance. Polymer nanocomposites are known to exhibit superior properties and, therefore, offer great potential for this type of application. Nevertheless, the degree of enhancement of a particular property is greatly dependent upon the matrix/nanoparticle material system used, the matrix/nanoparticle interfacial bonding and also the state of dispersion of the nanoparticle in the polymer matrix. The objective of the present research is to develop and characterize polymer based nanocomposites to be used as coatings in metallic pipelines for the transportation of oil and natural gas. Epoxy/SiO2 nanocomposites with nanoparticle contents of 2, 4, and 8 wt % were processed using a high-energy mill. Modifications of the SiO2 nanoparticles‟ surfaces with two different silane agents were carried out and their effect on the material properties were investigated. The state of dispersion of the materials processed was studied using Scanning and Transmission Electron Microscopy (SEM and TEM) micrographs. Thermogravimetric analysis (TG) were also conducted to determine the thermal stability of the nanocomposites. In addition, the processed nanocomposites were characterized by dynamic mechanical analysis (DMA) to investigate the effect of nanoparticles content and silane treatment on the viscoelastic properties and on the glass transition temperature. Finally, wear tests of the pin-on-disc type were carried out to determine the effects of the nanoparticles and the silane treatments studied. According to the results, the addition of SiO2 nanoparticles treated with silane increased the thermal stability, the storage modulus and Tg of the epoxy resin and decreased wear rate. This confirms that the interaction between the nanoparticles and the polymer chains plays a critical role on the properties of the nanocomposites

Análise da sensibilidade do biodiesel B5 em frotas de transporte coletivo com motorização diesel

The aim of this study was investigate the consolidation of the biodiesel fuel used in (a) engines of urban and intercity bus companies, (b) a stationary engine. It was necessary to investigate and analyze, technologically, if the biodiesel fuels were presenting troubleshooting relative to wear of parts lied to fuel and to evaluate the consumption fluctuations of this fuel. The urban and intercity bus companies, localized in Natal, Rio Grande do Norte state, Brazil, had 41 and 12 vehicles, respectively. It were analyzed datasheet of each one vehicle during three years, since 2008 until 2010 and were interviewed the management of the maintenance team of bus companies relative to aspects concerning the substitution of the diesel fuel by the B5 biodiesel. The second aim of this study was visually inspect the wear of the parts directly lied to combustion process. For this reason, it was investigated a stationary engine, manufactured by Branco BD5, 5 HP of power, fueled by (a) diesel, (b) biodiesel B5, (c) biodiesel B20 and (d) diesel or biodiesel, both contaminated by distilled water. In this engine, its power utilizing biodiesel B5 versus diesel was lower about 5.2% and, in the investigated case of B20 versus diesel, it was lower around 11.5%

A influência do esqueleto açúcar-fostato no transporte da molécula de DNA

This dissertation analyses the influence of sugar-phosphate structure in the electronic transport in the double stretch DNA molecule, with the sequence of the base pairs modeled by two types of quasi-periodic sequences: Rudin-Shapiro and Fibonacci. For the sequences, the density of state was calculated and it was compared with the density of state of a piece of human DNA Ch22. After, the electronic transmittance was investigated. In both situations, the Hamiltonians are different. On the analysis of density of state, it was employed the Dyson equation. On the transmittance, the time independent Schrödinger equation was used. In both cases, the tight-binding model was applied. The density of states obtained through Rudin-Shapiro sequence reveal to be similar to the density of state for the Ch22. And for transmittance only until the fifth generation of the Fibonacci sequence was acquired. We have considered long range correlations in both transport mechanism

As fontes de desgaste físico e emocional e a Síndrome de Burnout no setor de transporte coletivo urbano de Natal

Recognizing the importance the workplace has on mental health of the individual, the objective of this study was to investigate the relationship between the burnout syndrome and the sources of physical and emotional wear which permeate the work conditions of the urban public transport system of the city of Natal. Although existent in international literature, research on burnout in the professional transport category and studies directed to this category are not a tradition in Brazil. The research was carried out using 412 drivers and money-changers of two transport companies of Natal. To collect the data, two questionnaires and a semi-structured interview were used. The first instrument, developed and validated during the research, investigated the sources of wear and the second, the syndrome of burnout. As its main results, two sources of empirical wear were identified as follows: (1) the Conflict of Values and the Lack of Justice at the Workplace, (2) Union and Reward. Besides these, it was observed that there is an incidence of the syndrome of burnout among the drivers and money-changers of urban transport by bus, not only in the caring occupations studied before in Natal and Brazil and that this incidence is related to the sources of wear which permeate the work conditions of these professionals

Passividade na interface prótese/pilar intermediário de infraestrutura implantossuportadas confeccionadas pela tecnologia CAD/CAM e método convencional

The objective of this research was to evaluate the passivity and strain induced in infrastructures screwed on abutments, made by CAD/CAM technology, and to compare these samples with parts manufactured by conventional casting. Using CAD/CAM technology, 4 samples were made from zirconia (Zircad) and 4 samples were manufactured from cobaltchrome (CoCrcad). The control groups were 4 specimens of cobalt-chrome, made by onepiece casting (CoCrci), for a total of 12 infrastructures. To evaluate the passivity, the infraestructures were installed on the abutments. One end was tightened and the vertical gap between the infrastructure and the prosthetic abutment was measured with scanning electron microscopy (250×). The mean strain in these infrastructures was analyzed via the photoelasticity test. A significant difference (p = 0.000) in passivity was observed between the control (CoCrci) and sample groups (CoCrcad and CoCrci). CoCrcad exhibited the best value of passivity (48.76 ± 13.45 μm) and CoCrci the worst (187.55 ± 103.63 μm), Zircad presented an intermediate value (103.81 ± 43.15 μm). When compared to the other groups, CoCrci showed the highest mean strain around the implants (17.19 ± 7.22 kPa). It was concluded that the zirconia infrastructure made by CAD / CAM showed a higher vertical marginal misfit than those made in cobalt-chromium alloy with the same methodology, however, the tension generated in the implants was similar. The CAD/CAM technology is more accurate for passivity and mean strain of infrastructure screwed on abutments than conventional manufacturing techniques

Transporte eletrônico e propriedades termodinâmicas de nanobiomoléculas

We use a tight-binding formulation to investigate the transmissivity and the currentvoltage (I_V) characteristics of sequences of double-strand DNA molecules. In order to reveal the relevance of the underlying correlations in the nucleotides distribution, we compare theresults for the genomic DNA sequence with those of arti_cial sequences (the long-range correlated Fibonacci and RudinShapiro one) and a random sequence, which is a kind of prototype of a short-range correlated system. The random sequence is presented here with the same _rst neighbors pair correlations of the human DNA sequence. We found that the long-range character of the correlations is important to the transmissivity spectra, although the I_V curves seem to be mostly inuenced by the short-range correlations. We also analyze in this work the electronic and thermal properties along an _-helix sequence obtained from an _3 peptide which has the uni-dimensional sequence (Leu-Glu-Thr- Leu-Ala-Lys-Ala)3. An ab initio quantum chemical calculation procedure is used to obtain the highest occupied molecular orbital (HOMO) as well as their charge transfer integrals, when the _-helix sequence forms two di_erent variants with (the so-called 5Q variant) and without (the 7Q variant) _brous assemblies that can be observed by transmission electron microscopy. The di_erence between the two structures is that the 5Q (7Q) structure have Ala ! Gln substitution at the 5th (7th) position, respectively. We estimate theoretically the density of states as well as the electronic transmission spectra for the peptides using a tight-binding Hamiltonian model together with the Dyson's equation. Besides, we solve the time dependent Schrodinger equation to compute the spread of an initially localized wave-packet. We also compute the localization length in the _nite _-helix segment and the quantum especi_c heat. Keeping in mind that _brous protein can be associated with diseases, the important di_erences observed in the present vi electronic transport studies encourage us to suggest this method as a molecular diagnostic tool

A integração do tutorial interativo TryLogic via IMS Learning Tools Interoperability: construindo uma infraestrutura para o ensino de Lógica através de estratégias de demonstração e refutação

Logic courses represent a pedagogical challenge and the recorded number of cases of failures and of discontinuity in them is often high. Amont other difficulties, students face a cognitive overload to understand logical concepts in a relevant way. On that track, computational tools for learning are resources that help both in alleviating the cognitive overload scenarios and in allowing for the practical experimenting with theoretical concepts. The present study proposes an interactive tutorial, namely the TryLogic, aimed at teaching to solve logical conjectures either by proofs or refutations. The tool was developed from the architecture of the tool TryOcaml, through support of the communication of the web interface ProofWeb in accessing the proof assistant Coq. The goals of TryLogic are: (1) presenting a set of lessons for applying heuristic strategies in solving problems set in Propositional Logic; (2) stepwise organizing the exposition of concepts related to Natural Deduction and to Propositional Semantics in sequential steps; (3) providing interactive tasks to the students. The present study also aims at: presenting our implementation of a formal system for refutation; describing the integration of our infrastructure with the Virtual Learning Environment Moodle through the IMS Learning Tools Interoperability specification; presenting the Conjecture Generator that works for the tasks involving proving and refuting; and, finally to evaluate the learning experience of Logic students through the application of the conjecture solving task associated to the use of the TryLogic