Thesis (M. Soc. Sc.)--University of Hong Kong, 1984.

Thesis (M.Soc.Sc.)--University of Hong Kong, 1984. / Also available in print.

Orientador: Laurence Duarte Colvara / Banca: Percival Bueno de Araujo / Banca: Silvia Galvão de Souza Cervantes / Resumo: O presente trabalho trata da influência de transformadores de relação de transformação variável, o ULTC (Under Load Tap Changing) e o PS (Phase Shifter Transformer), nas interações entre máquinas em um ambiente multimáquinas. A rede é reduzida às barras internas dos geradores com representação das consequências da ação do ULTC e do PS nas admitâncias de transferência entre máquinas. São determinados coeficientes denominados coeficiente de eficácia e Fator de Efeito, em que se identificam propriedades úteis para avaliar os efeitos da variação da relação de transformação do ULTC e do PS nas interações entre cada par de máquinas do sistema, assim como estabelecimento de lei de controle do próprio ULTC e do PS com vistas a determinado desempenho dinâmico/transitório / Abstract: This work deals with the influence of the variable ratio transformer, the ULTC (Under Load Tap Changing) and the PS (Phase Shifter Transformer) in the interactions between machines in a multimachines environment. The network is reduced to the internal busses of generators with representation of the consequences of the PS and the ULTC action in the transfer admittances between machines. Coefficients called effectiveness coefficient and Effect Factor are determined, which have useful properties for evaluating the effects of changes in the transformation ratio of the ULTC and the PS in the interactions between each generic pair of system machines, as well as establishing the control law of the ULTC and the PS overlooking a particular dynamic/transient performance / Mestre

Devido à sua natureza, o gás natural (GN) tem na distância aos pontos de consumo um obstáculo para sua utilização, a qual vai além simples queima para geração de energia ou obtenção de calor. Portanto, é importante que sejam discutidos novos métodos para distribuí-lo e transformá-lo em fontes de energia de maior valor agregado ou em matéria-prima para fabricação de produtos a serem utilizados na indústria química. Uma opção é a conversão do GN em combustíveis líquidos de pronto uso como óleo diesel, gasolina e querosene de aviação através da rota Gas-To-Liquids (GTL). O presente trabalho avalia o potencial da tecnologia GTL no contexto do crescimento da oferta de gás natural no Brasil pelos gasodutos Rota 2 e Rota 3, contextualizando o cenário brasileiro desse energético, as perspectivas futuras e o estado da tecnologia GTL com o processo Fisher-Tropsch. Para tanto, é simulado e analisado o desempenho econômico de uma planta de diesel GTL operante por 30 anos em cenários de preços de insumo e produto obtidos por projeções de reconhecimento internacional. / The usage of natural gás (NG) is related to the distance to the final customers, that is a real obstacle to its full utilization which is beyond the usage as fuel for electricity or heat generation. It is important to prospect, analyze and propose new methods for distribution and transformation of this important energy suppy to more value added products or special raw material for the chemical industry. The transformation in ready for use liquid fuels like diesel, gasoline and kerosene through the gas-to-liquid route (GTL) is one of the options. This dissertation evaluates the GTL technology in a context of the NG additional volume available through 2 new pipelines coming from offshore, Rota 2 and Rota 3 in the Brazilian context of NG current usage and its future perspectives taking advantage of this additional availability via the traditional and long term tested GTL Fischer-Tropsch (FT) technology. A GTL FT Diesel plant operating for 30 years was taken as an example considering different scenarios for NG and Oil prices retrieved from the IEA data base that is internationally considered as a consistent source of information.

This diploma thesis deals with the historical development of passive optical networks, according to the standards that was defined by International Telecommunication Union (APON, BPON, GPON, XG-PON and NG-PON). Further, the thesis describes the security of passive optical networks, but also a security threats which the deployment and use of passive optical technology carry. In the introductory chapters of this thesis the passive optical networks are described. The following is a description of the standards of passive optical networks in terms of their historical development. The next part is dedicated to the security of passive optical networks and possible security threats. In conclusion a description of the practical part of this thesis is given -- rack assembly, which will serve for future testing. The basic configuration of the optical line terminations that are fitted in the rack is also described. The last part of this diploma thesis is dedicated to the testing of selected security risks, which was described in the theoretical part of this thesis.

This diploma thesis describes the design of retractable landing gear for the NG-4 ultralight aircraft. Its main part consists of general principle of gear retraction, kinematics analysis, load calculation and structural analysis, material selection and means of controlling by pilot. The thesis contents marginally the typology of aircraft landing gears and their evolution.

The aim of this thesis is to create a client xDB database, which supports visualization and management of XML documents and schemas. The first part deals with the introduction of XML, XML schemas (DTD, XML Schema, RelaxNG, etc.) and contextual technologies. After that the thesis deals with the problem of the XML persistence and it focuses on mapping techniques necessary for an efficient storage in a relational database. The main part is devoted to the design and implementation of client application XML Admin, which is programmed in Java. The application uses the XML:DB interface to communicate with the xDB database. It supports storing XML documents to a collection and the XPath language for querying them. The final section is devoted to application performance testing and comparison with existing native database eXist.

The diploma thesis deals with the problems of DoS/DDoS attacks and development of a tool, in C lanugage, for generating them. In the first chapter the principles of DoS attacks targeting the internet and transport layers of ISO/OSI model are described and also according to their characteristics divided. Selected attacks on the application layer are also described here in detail togehter with protocols which they are based on. In the following chapter there has been created a comparison of freely available tools, which could be used as a attack generators. The practical part is dedicated to a development of a tool for DoS attacks, especially design, general description and usage. Further there is a summary of the newly created library, including results of web server testing, and extensions of a web interface, which is part of the developed tool.

What do we require from the labor market in order for it to contribute to a free life? And will the labor market of the future live up to what we expect from it? This study examines how a political philosophy of Hegelian inspiration helps us understand the conditions by which the labor market could be capable of providing for what Axel Honneth refers to as ’social freedom’. An analysis by French jurist Alain Supiot is presented as an informative example of this theoretical framework. Supiot develops a sophisticated critique of the deficiencies of the contemporary labor market, while simultaneously pointing at some professions whose function testify of the possibility of the labor market of generating social freedom under proper conditions. As such, I show that a critical framework of Hegelian inspiration is immensely potent as to its capacity of understanding what we require from the labor market at this time of history. Immensely potent, but perhaps insufficient. Indeed, by introducing the research of Aaron Benanav pertaining to the development of the global labor market, this study corroborates the critique of Honneth and Supiot—a critical framework already introduced by Karen Ng and Timo Jütten—concerning the possibilities of the labor market of providing social freedom at any significant scale and thus hints at the probable necessity of overcoming capitalism during the time to come.

Tools that automate processes are always sough after across the entire IT field. This project's aim was to build and evaluate a semi-automated reconnaissance tool based on a Raspberry Pi 4, for use in penetration testing and/or digital forensics. The software is written in Python 3 and utilizes Scapy, PyQt5 and the Aircrack-ng suite along with other pre-existing tools. The device is targeted against wireless networks and its main purpose is to capture what is known as the WPA handshake and thereby crack Wi-Fi passwords. Upon achieving this, the program shall then connect to the cracked network, start packet sniffing and perform a host discovery and scan for open ports. The final product underwent three tests and passed them all, except the step involving port scanning - most likely due to hardware and/or operating system faults, since other devices are able to perform these operations. The main functionalities of this device and software are to: identify and assess nearby network access points, perform deauthentication attacks, capture network traffic (including WPA handshakes), crack Wi-Fi passwords, connect to cracked networks and finally to perform host discovery and port scanning. All of these steps shall be executed automatically after selecting the target networks and pressing the start button. Based on the test results it can be stated that this device is well suited for practical use within cyber security and digital forensics. However, due to the Raspberry Pi's limited computing power users may be advised to outsource the cracking process to a more powerful machine, for the purpose of productivity and time efficiency.