This dissertation argues that admission control should be applied as early as possible within a system. To that end, this dissertation examines the benefits and trade-offs involved in applying admission control to a networked computer system at the level of the network interface hardware. Admission control has traditionally been applied in software, after significant resources have already been expended on processing a request. This design decision leads to systems whose algorithmic cost is a function of the load applied to the system, rather than the load admitted to the system. By performing admission control at the network interface, it is possible to develop systems whose algorithmic cost is a function of load admitted to the system, rather than load applied to the system. Such systems are able to deal with excessive applied loads without exhibiting performance degradation. This dissertation first examines existing admission control approaches, focussing on the cost of admission control within those systems. It then goes on to develop a model of system behaviour under overload, and the impact of admission control on that behaviour. A new class of admission control mechanisms which are able to perform load rejection using the network interface hardware are then described, along with a prototype implementation using commodity hardware. A prototype implementation in the FreeBSD operating system is evaluated for a variety of network protocols and performance is compared to the standard FreeBSD implementation. Performance and scalability under overload is significantly improved.

Mémoire (M.Sc.)--Université du Québec à Chicoutimi, 1978. / Document électronique également accessible en format PDF. CaQCU

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Nur Yazdani, Florida State University, FAMU-FSU College of Engineering, Dept. of Civil Engineering. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains xi, 178 pages. Includes bibliographical references.

Resumo: No presente trabalho é apresentado um método para o cálculo de volumes determinados por K-Hiperbolóides de Carga e Potência, de modo a reduzir os gastos de empresas consideradas, em relação ao fator de potência. A redução de gastos é obtida alterando-se o valor máximo do fator potência que se pretende chegar, do fator de potência ideal "1", para o fator de potência de referência "0,92", ou mantendo-o quando já estiver acima de 0,92. Quando o fator de potência é maior ou igual a 0,92 ele já está eficiente, assim, não há necessidade de se chegar ao fator de potência ideal. É realizada uma comparação entre um método existente na literatura e o método proposto no presente trabalho, para determinar os pontos em que estes métodos diferem no cálculo dos volumes determinados pelos K-Hiperbolóides de Carga e Potência e mostrar a eficácia do método proposto. Estes métodos são equiparados, com relação a redução obtida no faturamento da conta de energia elétrica. A redução no faturamento da conta de energia elétrica que deve ser pago à concessionária é obtida por meio da diminuição da demanda contratada pela empresa; por sua vez a diminuição desta demanda é alcançada através da fórmula do fator de carga. Considerando-se a demanda média e o maior fator de carga obtido no período em estudo, encontra-se assim, uma nova demanda máxima menor que a demanda atual utilizada pela empresa. Logo, esta demanda máxima passa a ser a demanda que será contratada pela empresa, assim, esta nova demanda resulta em uma nova fatura que deve ser paga a concessionária de energia elétrica, menor que a fatura atual. / Abstract: The present work presents a method for the calculation of volumes determined for K- Load and Power Hyperboloid, in order to reduce the expenses of considered companies, in relation to the power factor. The reduction of expenses is gotten by changing the maximum value of the wished power factor, of the ideal power factor"1", to the reference power factor "0,92",or keeping it when it’s above 0,92. When the power factor is higher or equal 0,92, it’s already efficient, thus, it is not necessary to achieve the ideal power factor. A comparison is carried between an existing method in the literature and the considered method in the present work, to determine the points where these methods differ from each other in the calculation of the volumes determined for the K-Load and Power Hyperboloid and to show the effectiveness of the considered method. These methods are equalized, regarding the reduction gotten in the invoicing of the electric energy account. The reduction in the invoicing of the account of electric energy that must be paid to the concessionaire is gotten through the reduction of the contracted demand by the company; in turn the reduction of this demand is reached through the formula of the load factor. Considering the average demand and the highest load factor gotten in the period in study, this way a new demand, lower than the current demand used by the company, is gotten. Therefore, this maximum demand starts to be the demand that will be contracted by the company, thus, this new demand results in a new invoice which must be paid to the concessionaire of electric energy, lower than the current invoice. / Orientador: Francisco Villarreal Alvarado / Coorientador: Antonio Padilha Feltrin / Banca: Sérgio Azevedo de Oliveira / Banca: Iara Fernanda Ehrenberg Dossi Denis / Mestre

The aim of this dissertation thesis is an optimization of access to CDMA networks. To be more specific, this thesis deals with an optimization of admission control in UMTS network. The first part of the thesis deals with the present progress of the particular topic. Thereinafter there is an analysis of admission control in UMTS system. An own UMTS simulation program was created in MATLAB. This program enables implementation and simulation of the selected admission control algorithms. The thesis is focused on load factor based, fuzzy logic based and genetic algorithms. The created UMTS simulator was used for the mutual comparison of all algorithms. The aims of this thesis are the suitable UMTS model design, evaluation and possible optimization of selected algorithms.

A transition phase is taking place in Sweden, where the goal is to become a completely climate neutral country by 2045. The transport sector currently accounts for a third of fossil emissions in Sweden, while the transport sector also has the greatest potential to become fossil-free through, forexample, a comprehensive electrification. Bottlenecks in the grid is a challenge that Sweden faces where the existing ability to send powerthrough the country is already highly utilized. Battery storage can partly be the solution to this problem and also support the future needs that a further electrification of the transport sector may cause. Battery storage can, however, be both expensive and require a lot of space. To avoid this, the mobile battery storage that is available in electric cars can be used to convey power to the grid based on need. The technology that performs this bidirectional charging is called V2G (vehicle-to-grid) and has enormous theoretical potential. The number of electric cars in Sweden has increased by 82% duringthe year 2020, which provides good conditions for continuing to investigate the potential for V2G. Previous studies have shown challenges with the technology. The main issues pointed out have been profitability, winter conditions and battery wear, all of which are taken into account in this study. As in all of Sweden, Halmstad needs to plan for its electrification of the transport sector and load consequences on the grid. This study carries out a combined qualitative and quantitative case study that examines how a future electric car fleet can affect Halmstad's local grid. With data from HEM Nät from a winter week that will correspond to extreme conditions for the grid, a model has been developed in Excel to test different proposed scenarios. What is analyzed is how V2G can work in practice depending on where and when charging takes place, and whether power regulation can be profitable for both private individuals and network operator. Results show that some form of power regulation will be needed in the future to deal with the consequences of uncontrolled electric car charging with an ever-larger electric car fleet, and that V2G may be an option. Despite the winter climate and consideration for battery wear, a significant power peak reduction can be achieved if sufficient participation is attained and a good control strategy is found. Financial analysis shows a negative outcome for private individuals who use V2G. The utility services that is provided can on the other hand reduce costs for the network operator through load balancing incentives and reduced subscriptions to overlying networks. This in turn can enable an interest in network operators to introduce local incentives for private individuals' involvement.

Power industry restructuring has created many opportunities for customers to reduce their electricity bills. In order to facilitate the retail choice in a competitive power market, the knowledge of hourly load shape by customer class is necessary. Requiring a meter as a prerequisite for lower voltage customers to choose a power supplier is not considered practical at the present time. In order to be used by Energy Service Provider (ESP) to assign customers to specific load profiles with certainty factors, a technique which bases on load research and customers¡¦ monthly energy usage data for a preliminary screening of customer load profiles is required. Distribution systems supply electricity to different mixtures of customers, due to lack of field measurements, load point data used in distribution network studies have various degrees of uncertainties. In order to take the expected uncertainties in the demand into account, many previous methods have used fuzzy load models in their studies. However, the issue of deriving these models has not been discussed. To address this issue, an approach for building these fuzzy load models is needed. Load aggregation allows customers to purchase electricity at a lower price. In some contracts, load factor is considered as one critical aspect of aggregation. To facilitate a better load aggregation in distribution networks, feeder reconfiguration could be used to improve the load factor in a distribution subsystem. To solve the aforementioned problems, two data mining techniques, namely, the fuzzy c-means (FCM) method and an Artificial Neural Network (ANN) based pattern recognition technique, are proposed for load profiling and customer class assignment. A variant to the previous load profiling technique, customer hourly load distributions obtained from load research can be converted to fuzzy membership functions based on a possibility¡Vprobability consistency principle. With the customer class fuzzy load profiles, customer monthly power consumption and feeder load measurements, hourly loads of each distribution transformer on the feeder can be estimated and used in distribution network analysis. After feeder models are established, feeder reconfiguration based on binary particle swarm optimization (BPSO) technique is used to improve feeder load factors. Test results based on several simple sample networks have shown that the proposed feeder reconfiguration method could improve customers¡¦ position for a good bargain in electricity service.

Condition assessment and safety verification of existing bridges and decisions as to whether bridge posting is required are addressed through analysis, load testing, or a combination of methods. Bridge rating through structural analysis is by far the most common procedure for rating existing bridges. The American Association of State Highway and Transportation Officials (AASHTO) Manual for Bridge Evaluation (MBE), First Edition permits bridge capacity ratings to be determined through allowable stress rating (ASR), load factor rating (LFR) or load and resistance factor rating (LRFR); the latter method is keyed to the AASHTO LRFD Bridge Design Specifications, which is reliability-based and has been required for the design of new bridges built with federal findings since October, 2007. A survey of current bridge rating practices in the United States has revealed that these three methods may lead to different ratings and posting limits for the same bridge, a situation that carries serious implications with regard to the safety of the public and the economic well-being of communities that may be affected by bridge postings or closures. To address this issue, a research program has been conducted with the overall objective of providing recommendations for improving the process by which the condition of existing bridge structures is assessed. This research required a coordinated program of load testing and finite element analysis of selected bridges in the State of Georgia to gain perspectives on the behavior of older bridges under various load conditions. Structural system reliability assessments of these bridges were conducted and bridge fragilities were developed for purposes of comparison with component reliability benchmarks for new bridges. A reliability-based bridge rating framework was developed, along with a series of recommended improvements to the current bridge rating methods, which facilitate the incorporation of various in situ conditions of existing bridges into the bridge rating process at both component and system levels. This framework permits bridge ratings to be conducted at three levels of increasing complexity to achieve the performance objectives, expressed in the terms of reliability, that are embedded in the LRFR option of the AASHTO Manual of Bridge Evaluation. This research was sponsored by the Georgia Department of Transportation, and has led to a set of Recommended Guidelines for Condition Assessment and Evaluation of Existing Bridges in Georgia.

The objective of the thesis was to focus on all the necessary requirements needed at first for establishing an airline company and then for establishing a regular air route. The thesis also contains a practical part - an analysis of Delta Air Lines company and her two already operated direct and regular air routes Prague - New York and Prague - Atlanta. The thesis has through the company focused on description of operating passenger air transportation from the point of view a network airliner. Part of the objective was to show the contemporary state of the air transportation branch and outlining its possible future development with regard to the chosen airline company.

This master thesis deals with the landing gear rebuild from tail gear to nose gear of the M-4 Irbis aircraft. The first chapter presents the aircraft in its current state and includes some technical data, too. The theoretical information about types of landing gears, its characteristics, pros and cons and the typical representatives for each type of landing gear are mentioned in the second chapter. The third chapter is about landing gear loads that occur during landing and about the load calculation according to UL 2 regulation. The following chapter shows the construction of the new landing gear, including some of the suggested, but not realised, designs. In the fifth chapter, there is a landing gear strength calculation of some of the gear components. The calculation is analytical and then uses FEM. The very last chapter then shows the effect of new landing gear on the centre of gravity in its extreme positions. The chapter also compares aircraft masses with both landing gears.