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USING MODERN NUMERIC METHODS IN DESIGN OF LOW VOLTAGE CIRCUIT BREAKERS
Dostál, Lukáš ; Hüttner, Ľudovít (referee) ; Petráček, Miloš (referee) ; Aubrecht, Vladimír (advisor)
The theses is focused on efficient use of numerical methods in development of low-voltage switching devices, namely to create a physically correct and reliable numerical model of the temperature field to find an application in the design of the current path of a device for various operating conditions. The creation of this numerical model requires not only correct inclusion of all modes of heat transfer - conduction, convection and radiation, but also correct solution of problematic transient resistance - both electrical and thermal in electrical contacts at different stages of usage. Therefore an essential part of the theses forms a thorough experimental analysis of the necessary material properties and dependencies which forms input data for the numerical model that is based on the finite volume method. The last part of the theses deals with debugging and verification of numerical model to correspond with experimentally obtained data. The result of the theses is the numerical model which is able to solve correctly both steady and various transient states of swiching devices.
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Data flow Control in Autonomous Systems
Důbrava, Marek
The paper deals with the management of packet traffic over IP networks at the level of the autonomous system. A new real time mechanism for active network traffic control depending on the state of the network load is described. The new mechanism allows us to differentiate network traffic depending on the user and manage it according to the defined parameters.
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Influence of Extension of Load Spectrum on Estimation of Residual\nFatigue Lifetime of Railway Axle
Pokorný, Pavel ; Hutař, Pavel ; Náhlík, Luboš
Railway axles are subjected to cyclic amplitude loading which can lead to fatigue failure.\nFor safe operation of railway axles a damage tolerance approach taking into account a possible\ndefect in railway axle is often required. Because of different operation regimes of trains (fast/slow\nride, ride on straight track, on curved track, over switches etc.) the load amplitude of axle is not\nconstant. The variability of load is defined by a load spectrum, which is determined experimentally\nby measuring of load in service conditions. Even though the load spectrum is measured on several\nhundreds or thousands of operation kilometres, the railway axles are in operation much longer time\n(often tens of years). Therefore, some load amplitudes higher than ones measured in the test can\noccur during a long-term axle service. The contribution presented deals with the effect of extension\nof load spectrum by rare high load amplitudes, which can occur during long-term operation, on\nresidual fatigue lifetime of railway axles.
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Prevention injuries cause by overloading and compensatory program of tennis players
Milerová, Klára ; Matouš, Miloš (advisor) ; Schreier, Bronislav (referee)
Tennis influences the posture of the athlete only one-sided which is the reason of muscle inbalances. These inbalances together with oveloading and other inner and outer factors are critical at injury incidence. This work is mostly about tennis injuries caused by overloading, mechanism of its origin and usual localization. There are also noticed rules of compenzatory exercises - stretching, relaxing and strenghtening. Special attention is given to practising of the correct breathing stereotypes, activation of deeper stabilization system and stabilization of sole. Powered by TCPDF (www.tcpdf.org)
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Optimization of signalization channel for Internet television
Matej, Michal ; Balej, Jiří (referee) ; Müller, Jakub (advisor)
The aim of this Bachelor's thesis is to propose a mechanism for optimizing the signaling channel in case of Feedback Target overload in hierarchical aggregation tree. Consequently to this verify the implementation of this mechanism in simulation environment of Java and to achieve the balance load among Feedback Targets. The theoretical part discusses the significant differences between traditional television transmission and television transmitted via the IP protocol, the methods of data transmission in IP network and key protocol called Tree Transmission Protocol working on the application layer of TCP/IP model. In this part there are explained the concepts of hierarchical aggregation of feedback channel such as Feedback Target Manager, Feedback Target, as well as packets FTD, FTS, and FTI.
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Line protection against overload and short circuit
Konšel, Ladislav ; Vaněk, Jaromír (referee) ; Valenta, Jiří (advisor)
This work includes a theoretical treatise on the operation of electrical wiring for the overload and short circuit. This is mainly on thermal effects of over current and their influence on the properties of conductors and insulation. Work Includes links to determine the load current, depending on the properties of leadership and its surroundings. It also deals with the protection of conductors against overload and short circuit. The work includes measurements process of warming wires. Practical project of proposal circuit is created using SICHR. The project includes proposals of conductor’s sizes and safety components for both residential building and individual flats.
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Possible physiotherapeutic solutions to the overload of shoulder girdles in historical fencers
SCHOLZOVÁ, Nikola
This thesis focuses on chronic overload of the shoulder girdles of historical fencers. In general, a shoulder is one of the most important joints for historical fencers. Overloading of the shoulder poses significant limits to the fencers´ abilities as it influences vigour of their chops and shielding. This thesis is divided into a theoretical and a practical part. The theoretical part comprises of the key findings of anatomy, kinesiology and biomechanics concerning the shoulder girdle. Further, it provides information about possibilities of a clinical examination. A qualitative research method was used in the practical part. Namely, this part worked with the techniques of informal interviews with respondents, history-taking, observation (kinesiology analysis), therapy applications in practice and secondary analysis of data collected. Moreover, there are the charts illustrating a change in the ranges of motions shown by the respondents at the entry and exit examination. The results of all kinds of therapy are presented in a form of case studies. The research was conducted under the supervision of Mgr. Matěj Liška in Pilsen. The test set consists of two respondents with chronic overload of the shoulder girdles. A therapeutic plan was compiled for both fencers. The plan has been successfully implemented. Fencers were thoroughly acquainted with the course and the goal of therapy and both agreed in writing with participation in this research and subsequent processing of the acquired data for my bachelor thesis. Therapy helped both respondents to relax the muscles of the shoulder girdle. Moreover, the upper limb function was improved and the ranges of motions of shoulder girdles increased. This thesis could serve as a good example of how to adequately deal with this issue. Further, it explains some relaxation, stretching and strengthening exercises for the shoulder girdle leading to an increase in the range of motion in the shoulder joint and in muscle strength.
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Possibilities of Physiotherapy in paraplegic athletes, floorball players
KAŠTÁNKOVÁ, Marta
In recent decades a care of people with spinal cord lesions has changed dramatically. A current available literature points to the fact that the quality of life, whether in physical, mental or health level achieved an improvement. The physical activity for people in a chronic phase of the spinal cord injury is a key issue that contributes to maintaining an optimal health condition. Atypical movement stereotype resulting from the movement on the wheel-chair conduces to a possible overload of the body structures and subsequent health problems. These difficulties then may limit people with special needs in the movement, work as well as self-sufficiency. An aim of a theoretical part of the thesis was to identify existing knowledge on the impact of the physical activity on the state of paraplegics, on possible health problems resulting from the overloading and what physiotherapeutic methods could affect these issues. An aim of a practical part was an application of theoretical procedures into practice in a treatment of three sporting paraplegics. In the practical part there was conducted a qualitative research at three randomly selected people, floorball players. Men aged between 24 to 29 years with the paraplegia with a height of the lesion of Th8 - Th11. An observation of the patients was carried out for five weeks. Then a kinesiology analysis and three case-studies were conducted. After it a subjective opinion on the impact of sport on the musculoskeletal system and mental state was investigated by an interviewing technique with a specific question. Difficulties with a shoulder joint were identified at all three monitored individuals. Individually assembled and guided therapy led to the improvement of the shoulder girdle function at all three persons, to a an overall improvement of the sitting posture on the wheel-chair, to a treatment of the muscle imbalances and to an alleviation of the spine pain. The interview results showed that a regular sporting activity had a positive impact on the patients´ mental status. However, it negatively affected them by increasing demands on the whole musculoskeletal system.
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