This master’s thesis deals with a UMTS radio access network optimization, containing radio interface analysis, services and procedures description, ways to correct parameters calculations and settings and other issues necessary for a correct access network operation. The goal is effective network operation, minimum costs and maximum performance and flexibility of the network. The optimization during system operation is important because of the system character. The UMTS system uses the WCDMA technology, where particular users share the same frequency band and they are distinguished from one another via code sequences. The capacity of such a system is then given by the interference level - each particular user increases the interference level by the value corresponding to his transmit power. The maximum cell capacity is determined by the maximum interference level at which users can still operate with required services, so it is related not only to the number of users, but also to their bit rate. The optimization allows effective usage of the system for different services with different requirements. The main optimization tool is the radio resource management, containing number of algorithms, such as admission control, which decides the acceptance or rejection of a new user demanding certain service, power control, which ensure that users transmit with a minimal power sufficient for required service, handover and cell selection algorithms etc. The major parameter used by these algorithms is a cell load factor, which is related to the interference level margin. There are several methods for the load factor estimation and some of them are described in this work. Some other optimization techniques are mentioned here, too. This work also contains a laboratory exercise proposal for radio resource management introduction using the OPNET Modeler network simulation tool.

Orientador: Luís Roberto Almeida Gabriel Filho / Resumo: O consumo crescente por energia elétrica, o seu alto custo e as restrições ambientais tornaram imprescindíveis a utilização eficiente desta energia, bem como a execução de ações e programas que promovam economia de eletricidade. Diversas empresas agroindustriais no Brasil produzem a própria ração para alimentação de seus animais por meio da trituração de grãos e cereais, empregando maquinários movidos a motores elétricos muitas vezes sobredimensionados e operando em horários nos quais as tarifas são onerosas (horário de ponta). Essa atividade é responsável por grande parte do consumo de eletricidade e impacta diretamente os custos de produção. Nesta pesquisa, desenvolveu-se um modelo matemático de faturamento de energia elétrica para uma empresa de avicultura de postura optante pela modalidade tarifária verde. Esse modelo trabalha com equações matemáticas contendo variáveis elétricas necessárias ao cálculo da conta de eletricidade. Os principais parâmetros elétricos são os fatores de potência e de carga, a demanda de potência e o consumo de energia. Atualmente no Brasil, para os consumidores do Grupo A, existem duas modalidades tarifárias disponíveis: a horária verde e a horária azul. O modelo matemático proposto pode ser empregado para as duas modalidades, sendo que cada uma delas possui as suas fórmulas específicas, as quais deverão ser inseridas no software Mathematica criado pela empresa Wolfram Research. A direção da granja cedeu 12 contas de energia elétrica e seus dado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The increasing consumption of electricity, the high costs and the environmental restrictions made it paramount the efficient use of such energy, as well as actions and programs to promote energy conservation. Several agro-industrial companies in Brazil produce their own animal feed by mashing cereals and grains with the use of electric-motor machines, which are many times oversized and operate at expensive fee times (peak time). This activity is responsible for great part of the electricity consumption and directly impacts the production costs. This study developed a mathematical model of electricity billing for a laying poultry farm that opted for the green fee modality. This model uses mathematical equations containing the electric variables required for the calculation of the electric bill. The main electrical parameters are: the power and the load factors, the power demand, and the active consumption. Currently in Brazil, there are two fee modalities for Group A consumers: the green and the blue hourly fees. The proposed mathematical model can be used for both modalities, and there are specific equations for each of them, which should be entered into the software Mathematica developed by Wolfram Research. The manager of the poultry farm provided 12 electric bills, and their data was entered into the software that created three-dimensional surface graphs and contour maps. Such graphs showed the inversely proportional relation of the bill amounts with the power and load fac... (Complete abstract click electronic access below) / Mestre

Mobile Miner 40V is a machine used for rock excavation and developed by Epiroc. This machine is equipped with a large cutter wheel to perform the excavation. After a test run, some surfaces associated with bearings within the cutter wheel were found to be damaged due to scuffing - severe sliding wear. There is a static load applied to the surfaces due to gravity. However, the reason for this damaged issue was believed that there is a large dynamic load applied to the surfaces during the excavation. This dynamic load was not found in a previous FE model used to verify safety issues. Therefore, a new FE model that is more in line with reality, and a failure analysis were required. Additionally, a feasibility study for a cutter wheel with a larger dimension was also needed since a larger cutter wheel is desirable. Firstly, wear mechanisms were reviewed, and some theories were chosen to analyze the damaged issue. Since it was unknown whether the surfaces were well-lubricated or not, both cases were investigated. The Archard wear equation was used to analyze the poor-lubricated situation, while the lubrication number and the Reynolds equation were used to analyze the well-lubricated case. Secondly, contact mechanisms between the surfaces were also investigated. The investigation of the contact mechanisms involved several theories, such as the Hertzian contact theory and the impact load factor. Besides these theoretical analyses, a numerical analysis was performed. Lastly, a new FE model was established in Ansys. Both the cutter wheel which was subjected to scuffing(existing cutter wheel), and the cutter wheel with a larger dimension(larger cutter wheel) were analyzed by the use of the new FE model. The maximum and minimum wear rates obtained by the Archard wear equation are approximately 1.9・10-2mm3/m and 4.8・10-3mm3/m, which are considered as a completely unacceptable level in engineering applications. The maximum and minimum critical loads obtained by the Reynold equation are approximately 1.8kN and 24.8kN, which both are larger than the static load applied to the surfaces. The maximum and minimum critical mean contact pressures obtained by the lubrication number are approximately 65MPa and 240MPa, which both are larger than the mean contact pressure generated by the static load. No evidence shows that there is a large dynamic load applied to the surfaces during the excavation. The largest possible contact pressure on the bearings in the existing cutter wheel is very close to the limit of severely damaged. The largest possible contact pressure on the bearings in the larger cutter wheel is believed to exceed the limit of severely damaged. The previous assumption that the surfaces were damaged due to a large dynamic load was wrong. The obtained results support that the surfaces were only subjected to a static load and were damaged due to inadequate lubrication. The existing cutter wheel is operated safely with the current load cases. However, the forward thrust force is suggested to decrease when the cutting angle is large. There is a high risk if the larger cutter wheel is operated with the current load cases.

The Swedish energy markets inspectorate (Ei) regulates the Swedish DSOs revenue cap, to ensure reasonable prices, efficiency, and quality of supply towards the end users. In combination with directives from the European Union and Sweden's environmental goal, Ei implemented efficient grid utilization to the DSOs revenue cap in 2016. The efficient grid utilization can be divided into two incentives: load flow and network losses. Criticism regarding the load flow incentive, and the indicator used to calculate it, has been raised from the industry. The purpose of this degree project was to investigate the possibilities of a new indicator that also could be affected by the DSOs actions. The project identified four main indicators to test, weighted load factor, utilization factor, adjusted utilization factor and a utilization factor that incorporates all local production units. The indicators were calculated with data from a regional and local grid, provided by the Swedish DSO Ellevio. Other parameter changes such as peaks and seasonal based calculations were also tested. To see the impact DSOs could have on the indicator, with today's regulations, was detected to be through load shaving and shifting, demand side management (DSM). MATLAB was used to test the impact DSM had on the indicators. Further, a load prediction for the years 2023–2035, based on provided historical data, was executed to test the indicators long-term outcome. The project concluded that the regional grid had little to non-impact on the indicators with DSM whilst the local grid resulted in high increased outcome for most indicators. The project continues to conclude to separate indicators for the regional and local grid, to better represent the two grids characteristic and purpose in Swedish society. The adjusted utilization factor was proposed for the regional grid, due to its non-negative impact from installing renewable energy resources, and the weighted load factor for the local grid due to being highly affected by DSM. Lastly, the project concluded that the indicator needs to be changed and further developed for regional DSOs, for them to have the opportunity to affect it.

This thesis treats of QoS (Quality of Service) in UMTS system. The term quality of service is frequently used, recently, however not only in computer networks, but also more and more in mobile networks also. Present system of 2nd generation (2G) GSM enables only limited exploitation of QoS function. System UMTS is a system of 3rd generation (3G) already and contains quality of service in greater measure which is ensured with number of algorithms and functions. Individual QoS functions enable effective utilization of radio interface, support maintenance of planned coverage and offer high spectral efficiency. Functions that cater to quality of service are called RRM functions (Radio Resource Management). There exist five basic functions in UMTS system that are Admission control (AC), Power control (PC), Load control (LC), Handover control (HC) and Packet scheduler (PS). These functions are responsible for control of network access, control of power, control of network load, control of handover and packet (bit rate) scheduling. Last three functions are usually collectively designated as Congestion control, control of network overload. UMTS layer model, differentiation of services, traffic classes and 3GPP concept are also discussed. In thesis the attention is piad to Admission control algorithm – control of network access – in the uplink direction and to different ways of load (in the cell) modeling. Individual approaches are simulated in MATLAB. A possibility of using algorithm in the real system is discussed in conclusion.

France is planning a strong development of solar photovoltaics (PV) and wind power in the medium term disrupting the power system. This Master Thesis analyzes the impacts of variable renewable energy production on the supply-demand balance from 2021 to 2025 in France. The model used relies on a dynamic programming method. The analysis is based on the assessment of indicators such as price signals, margins, loss of load duration (LOLD), expected energy not served (EENS) and nuclear drop stop that characterize the supply-demand balance and the security of supply of the electricity system. Wind power and PV are two very different technologies. Their load factor is very sizeable as it characterize their seasonality, variability and predictability and has an impact on all medium-term indicators. Wind power and PV have low marginal costs and their production is seasonal and in anti-phase. With new installed capacity, their added production in the supply-demand balance will substitute first the imports from the interconnections until saturation and then nuclear and thermal power plant production. Prices decrease with the same seasonality as the production and need to be considered when establishing the nuclear planning for the years to come. In addition a re-optimization of hydro power is observed. In terms of security of supply, wind power is more efficient than PV when assessing the reduction of LOLD but both are far from the performance of combined cycle gas turbines (CCGT). Lastly, the lack of nuclear production opportunities increases considerably more with PV due to a very localised production during the day which coincides in summer with periods of low consumption. Wind power and PV are two distinct technologies and should not be put in the same category when assessing their impact on the power system. / Frankrike planerar en stark utveckling av solceller (PV) och vindkraft på medellång sikt för att störa kraftsystemet. Detta examensarbete analyserar effekterna av varierande produktion av förnybar energi på balans mellan utbud och efterfrågan från 2021 till 2025 i Frankrike. Modellen som används bygger på en dynamisk programmeringsmetod. Analysen baseras på bedömningen av indikatorer som prissignaler, marginaler, förlust av lasttid (LOLD), förväntad energi som inte serveras (EENS) och kärnkraftsfallstopp som kännetecknar efterfrågan och utbudssäkerheten för el systemet. Vindkraft och solceller är två mycket olika tekniker. Deras belastningsfaktor är mycket stor eftersom den kännetecknar deras säsongsvariation, variation och förutsägbarhet och påverkar alla medellångsiktiga indikatorer. Vindkraft och solceller har låga marginalkostnader och deras produktion är säsongsbetonad och i fas. Med ny installerad kapacitet kommer deras extra produktion i utbuds- och efterfrågan att ersätta importen från sammankopplingarna till mättnad och sedan produktion av kärnkraft och värmekraftverk. Priserna sjunker med samma säsong som produktionen och måste beaktas när kärnkraftsplaneringen fastställs för de kommande åren. Dessutom observeras en återoptimering av vattenkraften. När det gäller försörjningstrygghet är vindkraft effektivare än solceller vid bedömning av minskningen av LOLD men båda är långt ifrån prestanda för kombinerade cykelturbiner (CCGT). Slutligen ökar avsaknaden av kärnkraftsproduktionsmöjligheter betydligt mer med solceller på grund av en mycket lokal produktion under dagen som sammanfaller på sommaren med perioder med låg konsumtion. Vindkraft och solceller är två olika tekniker och bör inte placeras i samma kategori när man bedömer deras inverkan på kraftsystemet.