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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.
21

Výskyt poruch pohybového aparátu u sportovních koní / The incidence of musculoskeletal disorders in sport horses

ŠTĚRBA, Jakub January 2010 (has links)
The objective of this study was to evaluate the occurrence of locomotive organs disorders in sports horses. The locomotive organs condition is one of the determining factors of horse{\crq}s performance, thus it is also very important economical factor. The occurrence of the disorders is important not only for the given individual, but it can be used e.g. as the genetic information or the indicator of breeding management. The results of 151 horses in the age from 3 to 24 years were observed. Total of 10 radiographic images were evaluated in each horse. With respect to frequency and importance, following disorders were emphasized: occurrence and degree of modifications of navicular bone (navicular syndrome) and hock joint (bone spavin). Others modifications were observed on a smaller range. The results showed that only 11% of horses were free of any disorder. 89% of horses had at least one of the disorders, whereas 83% of them showed the disorder of navicular bone and 52% of them showed the disorder of bone spavin.
22

Vadné držení těla u dětí, žáků základních škol / Occurrence of poor posture by children, pupil of primary school (confrontation, eventualy interventional measures)

VODIČKOVÁ, Šárka January 2010 (has links)
Locomotive organ diseases, such as bad body control, belong nowadays to the most frequent chronic, non-infectious diseases. This problem is not only related to adults but the appearance of this problem in the early children´s age is constantly increasing. According to the research made in 2001 the prevalence of adult locomotive organ diseases varies from 16 % to 30 %, from which the appearance at women patients is more frequently recorded. Locomotive organ diseases at children, which need a long term medical monitoring, represent 16 %. The occurrence of bad body control was reported at 30 % of younger school age children in the Czech Republic. 50 % of the respondents in the age between 13 and 15 mentioned back ache. Changes in life style not only of adult generation, but above all, of children and teenagers, which result from today´s stressful life conditions, influence negatively human locomotive organs. This thesis focuses on the occurrence of bad body control at elementary school pupils at the age from 11 to 15. The theoretical part summarises knowledge about human locomotive organs, right and bad body control, moreover it gives information about methods used for bad body control diagnosing and it describes examination principles. At the end it covers possibilities of prevention. The practical part of this thesis collects and analyses facts gathered form a questionnaire. The questionnaires were given to pupils at elementary schools in small towns Sedlčany and Příbram and then in the capital city Prague. The aim of this thesis is to monitor the healthy life style of children, especially if they are encouraged to locomotive activities at school and in their free time. Correct method and variety of locomotive activities is very important in the early children´s age as prevention from locomotive organ diseases. Furthermore, the thesis focuses on risk factors causing the occurrence of bad body control, such as weight and long term, one sided spine load of. I try to process these facts and use them to verify or disprove the defined hypothesis. It was proved that children are encouraged to locomotive activities not only at school during their PE lessons, but also by their parents, they attend different sport clubs (football, hockey, dancing, canoeing) and they do a lot of sport activities in their free time (cycling, working out in the gym, swimming). The survey has also shown that on average children spend 6 hours a week doing sports activities and in the contrary they spend 20 hours a week watching television and playing computer games.
23

Design posunovací lokomotivy / Design of yard locomotive

Miklica, Martin January 2011 (has links)
Plenty of designing works focused on railway technology were made through the time. But the majority of them are concerned with high-speed trains or at least express train locomotives, but works devoted to design freight or shunting locomotives can be barely found. This diploma thesis is looking into nearly unexplored territory and finding out, which possibilities in the design of shunting locomotives of independent traction do exist, and find better solutions then those currently used, where possible and appropriate. The result of this master thesis work is design of shunting locomotive, which respects the requirements of railway standards, ergonomics and safety, and still brings in modern design solutions.
24

Zvýšení pružnosti zážehového přeplňovaného motoru na CNG / Improving Performance of Turbocharged CNG Engine

Janoušek, Michal January 2012 (has links)
The aim of diploma thesis is the design of fuel system for the Caterpillar twelve cylinder spark ignited turbocharged engine. The fuel system is designed for sequential electronic controlled gas injection into intake manifold. Computational model of the engine was calculated in Lotus Engine simulation software. CFD analysis of mixing CNG with air was computed in Star CCM+ software.
25

Design elektrické lokomotivy / Design of Electric Locomotive

Chropovský, Jiří January 2016 (has links)
The topic of this master’s thesis is design of electric locomotive, more specifically universal independent machine made for pull of personal trains and industrial trains as well. The main aim of this design is to create compact design which follows current estetical trends and fulfill technical and ergonomic needs.
26

Changes on the Horizon: The Evolution of Transportation Methods and Infrastructure in the American Southwest, 1870-1920.

Hieber, Nathaniel Paul 22 April 2021 (has links)
No description available.
27

Vibration Modeling and Experimental Analysis of a Locomotive Cab

Venezia, James J. Jr. 01 May 1997 (has links)
This study evaluates noise and vibrations in a heavy freight locomotive cab, and provides several measures for providing more comfort to the crew. A full-scale production cab and sill structure is used to provide the results. The cab is setup in a controlled laboratory environment in a manner similar to the installation on a locomotive. Field measurements are used to emulate actual vibration input to the cab structure. A 16-channel data acquisition system is used to collect both noise and vibration data on various parts of the cab structure and inside the cab. Upon establishing the baseline for laboratory vibration measurements and correlating them with field data, a design of experiment was conducted to evaluate the vibration contribution of various parts of the cab. This showed that the cab floor and cab roof had the largest vibrations. A series of solutions including stiffening the cab floor and damping the cab roof were investigated. The results showed that although such solutions reduce localized vibrations, the overall effect on reducing cab interior noise is minimal. As a more global solution, the cab was isolated from the sill structure through six elastomeric elements mounted at the base of the cab and at the crash post. The mounts at the base were selected such that they support the static weight of the cab, provide a resonance frequency that is below the excitation range, and offer good lateral and longitudinal stability. Two tube-form elastomeric mounts were placed between the cab structure and the crash posts which attach to the front of the sill structure. The test results showed that the soft-mounted cab had significantly lower noise and vibration than the original cab. The vibration levels were reduced 10 to 100 times at certain locations and frequency ranges. The overall noise level was reduced by approximately 6 dBA. In an attempt to provide an estimate of effectiveness of the mounts with different stiffness values, a simulation model was prepared in Matlab. Although the model did not yield accurate results, it resulted in several recommendations for future research work. / Master of Science
28

Traitement de la mission et des variables environnementales et intégration au processus de conception systémique / Treatment of the mission and environmental variables and integration in the system design process

Jaafar, Amine 28 September 2011 (has links)
Ce travail présente une démarche méthodologique visant le «traitement de profils» de «mission» et plus généralement de «variables environnementales» (mission, gisement, conditions aux limites), démarche constituant la phase amont essentielle d’un processus de conception systémique. La «classification» et la «synthèse» des profils relatifs aux variables d’environnement du système constituent en effet une première étape inévitable permettant de garantir, dans une large mesure, la qualité du dispositif conçu et ce à condition de se baser sur des «indicateurs» pertinents au sens des critères et contraintes de conception. Cette approche s’inscrit donc comme un outil d’aide à la décision dans un contexte de conception systémique. Nous mettons en particulier l’accent dans cette thèse sur l’apport de notre approche dans le contexte de la conception par optimisation qui, nécessitant un grand nombre d’itérations (évaluation de solutions de conception), exige l’utilisation de «profils compacts» au niveau informationnel (temps, fréquence,…). Nous proposons dans une première phase d’étude, une démarche de «classification» et de «segmentation» des profils basée sur des critères de partitionnement. Cette étape permet de guider le concepteur vers le choix du nombre de dispositifs à concevoir pour sectionner les produits créés dans une gamme. Dans une deuxième phase d’étude, nous proposons un processus de «synthèse de profil compact», représentatif des données relatives aux variables environnementales étudiées et dont les indicateurs de caractérisation correspondent aux caractéristiques de référence des données réelles. Ce signal de durée réduite est obtenu par la résolution d’un problème inverse à l’aide d’un algorithme évolutionnaire en agrégeant des motifs élémentaires paramétrés (sinusoïde, segments, sinus cardinaux). Ce processus de «synthèse compacte» est appliqué ensuite sur des exemples de profils de missions ferroviaires puis sur des gisements éoliens (vitesse du vent) associés à la conception de chaînes éoliennes. Nous prouvons enfin que la démarche de synthèse de profil représentatif et compact accroît notablement l’efficacité de l’optimisation en minimisant le coût de calcul facilitant dès lors une approche de conception par optimisation. / This work presents a methodological approach aiming at analyzing and processing mission profiles and more generally environmental variables (e.g. solar or wind energy potential, temperature, boundary conditions) in the context of system design. This process constitutes a key issue in order to ensure system effectiveness with regards to design constraints and objectives. In this thesis, we pay a particular attention on the use of compact profiles for environmental variables in the frame of system level integrated optimal design, which requires a wide number of system simulations. In a first part, we propose a clustering approach based on partition criteria with the aim of analyzing mission profiles. This phase can help designers to identify different system configurations in compliance with the corresponding clusters: it may guide suppliers towards “market segmentation” not only fulfilling economic constraints but also technical design objectives. The second stage of the study proposes a synthesis process of a compact profile which represents the corresponding data of the studied environmental variable. This compact profile is generated by combining parameters and number of elementary patterns (segment, sine or cardinal sine) with regards to design indicators. These latter are established with respect to the main objectives and constraints associated to the designed system. All pattern parameters are obtained by solving the corresponding inverse problem with evolutionary algorithms. Finally, this synthesis process is applied to two different case studies. The first consists in the simplification of wind data issued from measurements in two geographic sites of Guadeloupe and Tunisia. The second case deals with the reduction of a set of railway mission profiles relative to a hybrid locomotive devoted to shunting and switching missions. It is shown from those examples that our approach leads to a wide reduction of the profiles associated with environmental variables which allows a significant decrease of the computational time in the context of an integrated optimal design process.
29

Preference pohybových aktivit studentů Jihočeské univerzity / Preferences of Locomotive Activities of the Students of Southern Bohemian University

SOUSTRUŽNÍK, Michal January 2007 (has links)
The diploma thesis gives the information of the preferences of locomotive activities at chosen groups of the students of South Bohemian University. The preferences of the students that study Physical Education have been compared to the preferences of the students of other pedagogical subjects and also the mutual comparison of locomotive activities of women and men has been done. The research has been performed in a questionnaire form. The results have shown that young people currently prefer both traditional sports, and new, modern kinds of sports, developed in the last ten years. These activities also reflect the development of the society and economics, and also technical possibilities in new sport facilities.
30

[en] METHODOLOGY FOR SIZING THE GENERAL CARGO GRID FLEET FOR APPLICATION IN A CONCESSIONAIRE IN THE RAILWAY SECTOR / [pt] METODOLOGIA PARA DIMENSIONAMENTO DE FROTA DA GRADE DE CARGA GERAL PARA APLICAÇÃO EM UMA CONCESSIONÁRIA DO SETOR FERROVIÁRIO

PEDRO DUARTE GOMES TOSTES 11 February 2022 (has links)
[pt] A matriz brasileira de transporte retrata a dominância rodoviária sobre os demais modais, na movimentação de cargas no país. O aumento da eficiência operacional e redução de custos é fator que pode elevar a participação e competitividade dos trens nesse contexto. A aplicação de técnicas de otimização no processo de dimensionamento e planejamento operacional da frota de locomotivas possui grande potencial de economia de recursos, principalmente devido aos seus elevados custos de aquisição e manutenção. O presente trabalho apresenta uma metodologia para obtenção de uma solução exata para um horizonte mensal de planejamento, aproveitando se do caráter cíclico da grade de formação dos trens de carga geral, para definir o tamanho ótimo da frota necessário ao seu adequado funcionamento. A metodologia, implementada em linguagem Python e aplicada em um cenário de uma grade conhecida, teve sua frota resultante comparada com o dimensionamento manual realizado em uma concessionária brasileira e foi capaz de indicar a redução de 2 locomotivas no planejamento de frota. Associada a esta redução, a economia de capital estimada seria entre 400 mil reais e 20 milhões de reais, para o cenário conservador de economia dos gastos de manutenção e para o cenário mais otimista evitando a aquisição de novas locomotivas. Além da redução de frota e aumento na competitividade tarifária dos trens de carga geral, a metodologia cria, por meio de critérios científicos, diretrizes objetivas para o processo de dimensionamento e planejamento da frota de locomotivas, em substituição ao processo empírico atualmente aplicado na referida concessionária. / [en] The Brazilian transport matrix presents the road dominance over other modes in the movement of cargo in the country. The increase in operational efficiency and cost reduction is a factor that can increase the participation and competitiveness of trains in this context. The application of optimi zation techniques in the process of dimensioning and operational planning of the locomotive fleet has great potential for saving resources, mainly due to its high acquisition and maintenance costs. This work presents a methodology to obtain an exact soluti on for a monthly planning horizon, taking advantage of the cyclical character of the general freight trains timetables and defining the optimum fleet size necessary for its proper functioning. The methodology, implemented in Python language and applied in a scenario of a defined timetable had its resulting fleet compared with the manual sizing process carried out in a Brazilian dealership and was able to indicate the reduction of 2 locomotives in the fleet planning. Associated with this reduction, the est imated capital savings would be between 400 thousand reais and 20 million reais, for the conservative scenario of savings in maintenance costs and for the more optimistic scenario avoiding the acquisition of new locomotives. In addition to reducing the fleet and increasing the tariff competitiveness of general freight trains, the methodology creates, through scientific criteria, objective guidelines for the process of dimensioning and planning the locomotive fleet, replacing the empirical process currently applied in the aforementioned concessionaire.

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