Com a heterogeneidade de tecnologias de comunicação sem fio presentes na borda de redes de acesso, serviços providos na Internet podem ser acessados de forma quasi ubíqua através de dispositivos móveis ou portáteis. O acesso a esses serviços, contudo, está associado a atrasos e rupturas frequentes na comunicação devido a razões inerentes à mobilidade do dispositivo, como: i) perda de sinal em locais onde há pouca ou nenhuma cobertura de acesso móvel; ii) erros no quadro de dados durante a transmissão e, consequentemente, perdas de pacotes, que podem ser ocasionados por interferência no sinal ou enfraquecimento deste pelo distanciamento do dispositivo em relação à Estação Base; iii) mudanças de endereços IP durante transmissões em andamento causadas pela migração do dispositivo entre diferentes redes. Como consequência, aplicações falham com a ruptura de comunicações orientadas a conexão. Tratar a mobilidade de forma transparente à aplicação é um dos desafios da Computação Móvel e Ubíqua que vem sendo pesquisado ao longo da última década. Soluções foram propostas para operarem desde a Camada de Enlace à Aplicação. Muitas delas, entretanto, exigem modificações na pilha de protocolos TCP/IP e adição de infraestrutura específica de rede no suporte à comunicação fim-a-fim. Além de elevar o custo das etapas de implantação e manutenção, estratégias intrusivas e dependentes de infraestrutura adicional podem não apresentar desempenho satisfatório. Nesse contexto, propomos tratar a mobilidade no nível da própria aplicação através de Sessões de Comunicação que não falham com atrasos e desconexões. Operando somente nos nós-fim e de modo transparente às Camadas adjacentes de Aplicação e Transporte, as sessões não requerem infraestrutura adicional para intermediar ou controlar a comunicação entre pares, tampouco modificações em protocolos legados da pilha TCP/IP. O conceito de Sessões Tolerantes a Rupturas é implementado através de uma API de propósito geral em sistemas Linux que estende a interface de Sockets. A API é, na prática, uma camada transparente sobre o Socket que provê Ciência de Mobilidade à aplicação através de mecanismos para: acompanhar a localização de nós ao longo da duração de uma sessão; detectar rupturas nas transmissões causadas pela mobilidade do nó ou de seu par remoto; suspender e retomar sessões de forma eficiente, segura e confiável. Experimentos conduzidos em ambientes emulados e reais com equipamentos de uso comercial mostram a eficiência das sessões. Além de introduzir baixa degradação na vazão fim-a-fim, rupturas na transmissão podem ser detectadas em microssegundos e sessões suspensas são reabertas em milissegundos. Com um desempenho superior a solução de mobilidade geral da Camada IP, as sessões não necessitam de adaptações de software em equipamentos de rede / Nowadays services available on the Internet can be accessed from mobile devices while they roam across heterogeneous wireless networks. Due to the inherent reasons of device mobility, however, the access to such services is frequently involved with delay and disruptions. The most common reasons are: i) losing radio signal at places where mobile access coverage area is not available; ii) frame error, losses, and fading on the radio signal when the mobile device moves away from the Base Station; iii) changes on the devices IP address over ongoing transmission, while the mobile node migrates among different wireless networks. As result, networked application fails with disruptions on TCP connections established in the mobile users path. Handling seamlessly mobility on the Internet is a technical challenge of the Mobile Computing Paradigm. It has been widely researched over the last decade. Several solutions have been proposed to work from the Link Layer to the Application Layer. Most of them, however, work intrusively and require modifications in the classical TCP/IP protocol stack, as well as rely on additional network infrastructure to support mobile end-to-end communication. Besides increasing the cost of deployment and maintenance, intrusive and infrastructure dependent strategies may not present suitable performance. In this sense, we devised an architecture to handle mobility at the Application level by means of communication sessions that do not fail with delay, disruption or disconnection. Such sessions work only at the end-systems in a such way that: are fully transparent to the adjacent layers of Transport and Application; do not require additional network infrastructure to forward and manage the communication between two mobile peers; and do not impose any modification on the legacy protocols from the TCP/IP stack. The concept of Disruption-Tolerant Sessions is implemented in Linux by means of a general purpose API extended from the Socket interface. Such API is a transparent layer placed on top of the Socket to provide mobility awareness to the Application Layer. To do so, session services are provided for: tracking mobile peers along the session duration; detecting disruptions over TCP connection caused by mobility of the local or remote peer; suspending and resuming sessions with efficiency, security and reliability. Experiments conducted in emulated and real systems (off-the-shelf hardware and open source software) showed the desired efficiency. Besides introducing little overhead on the goodput, disruptions are detected in a range of microseconds and suspended sessions are resumed in milliseconds. With performance greater than the general IP layer mobility solution, the proposed sessions do not require software adaptation in the core of the network infrastructure

The increasing number of cores every generation poses challenges for high-performance in-memory database systems. While these systems use sophisticated high-level algorithms to partition a query or run multiple queries in parallel, they also utilize low-level synchronization mechanisms to synchronize access to internal database data structures. Developers often spend significant development and verification effort to improve concurrency in the presence of such synchronization. The Intel ® Transactional Synchronization Extensions (Intel ® TSX) in the 4th Generation Core™ Processors enable hardware to dynamically determine whether threads actually need to synchronize even in the presence of conservatively used synchronization. This paper evaluates the effectiveness of such hardware support in a commercial database. We focus on two index implementations: a B+Tree Index and the Delta Storage Index used in the SAP HANA ® database system. We demonstrate that such support can improve performance of database data structures such as index trees and presents a compelling opportunity for the development of simpler, scalable, and easy-to-verify algorithms.

The Legacy information systems were created with the purpose of automate process that before of the informatics invention were made in a manual way, these systems have gained prominence over the years because organizations have become increasingly dependent of them, and the information they generate and manage have a great value. Nowadays new tendencies and paradigms make that business and organizations base the majority of their process in information systems and it is imperative that new technology can works together with legacy systems, for this reason the information must be integrated. Therefore under this context, is necessary to raise an alternative solution for integrating information of different legacy systems. In this thesis, is examined the problem, is described the importance of legacy systems in contrast with new current technological tendencies, besides is analyzed tools which we can achieve information integration and is purposed an alternative solution to problem through a multiplatform information system integrator, additionally, it proposes a integration methodology, leaving an established base to perform the development of a new system in order to replace the legacy system. The proposed solution has been proven through a case study in a business tourism sector, which was able to verify: that it is possible to integrate information from a system that handles flat files, display the information on a web interface for example, and start migration to a new relational database. After completing the proof of solution, we can say that this can integrate information regardless of the operating system and can be used in different organizations or companies. / Los sistemas de información legacy o heredados fueron creados con la finalidad de automatizar procesos que antes de la invención de la informática se hacían de forma manual, estos sistemas han cobrado importancia con los años porque las organizaciones han ido dependiendo cada vez más de ellos y la información que generan y administran son de gran valor. Hoy en día con las nuevas tendencias y paradigmas hacen que los negocios y organizaciones basen la mayoría de sus procesos en los sistemas de información y es imprescindible que la nueva tecnología conviva con los sistemas legacy o heredados; por tal motivo la información debe ser integrada. Bajo este contexto, es necesario plantear una alternativa de solución que permita integrar la información de diversos sistemas legacy o heredados. En la presente tesis, se analiza el origen del problema, se describe la importancia de los sistemas legacy o heredados frente a las nuevas tendencias tecnológicas actuales, se analiza las herramientas con las que podemos lograr integración de información, y se propone una alternativa de solución al problema mediante un sistema integrador de información multiplataforma adaptable a cualquier tipo de negocio. Adicionalmente, se propone una metodología de integración que deja una base establecida para realizar el desarrollo de un nuevo sistema que reemplace al sistema legacy o heredado. La solución propuesta ha sido probada mediante un caso de estudio en una empresa del sector turismo, donde se pudo verificar: que es posible integrar la información de un sistema que maneja archivos planos, mostrar la información en una interfase Web por ejemplo, y empezar la migración hacia una nueva base de datos relacional. Después de realizadas las pruebas de la solución se puede afirmar que esta puede integrar información sin importar el sistema operativo y que puede ser usado en distintas organizaciones o empresas.

No description available.

The importance of knowing what type of traffic is flowing through a network is paramount to its success. Traffic shaping, Quality of Service, identifying critical business applications, Intrusion Detection Systems, as well as network administra- tion activities all require the base knowledge of what traffic is flowing over a network before any further steps can be taken. With SSL traffic on the rise due to applica- tions securing or concealing their traffic, the ability to determine what applications are running within a network is getting more and more difficult. Traditional methods of traffic classification through port numbers or deep packet inspection have been deemed inadequate by researchers thus making way for new methods. The purpose of this thesis is to investigate if a machine learning approach can be used with flow features to identify SSL in a given network trace. To this end, different machine learning methods are investigated without the use of port numbers, Internet Protocol addresses, or payload information. Various machine learning models are investigated including AdaBoost, Naive Bayes, RIPPER, and C4.5. The robustness of the results are tested against unseen datasets during training. Moreover, the proposed approach is compared to the Wireshark traffic analysis tool. Results show that the proposed ap- proach is very promising in identifying SSL traffic from a given network trace without using port numbers, Internet protocol addresses, or payload information.

In recent years, Internet of Things has developed rapidly, and now has penetrated into human life and industrial production. It is speculated that the internet of things will become ubiquitous in the future, which will bring a series of problems. First, the large number of things will lead to operated system and software updates consuming a lot of manpower and resources. Another problem is the Internet of things facing security issues, in recent years for the means of Internet of things and tools have been increasing largely. Therefore, to achieve a secure automatic update on the Internet of Things is essential. This report will follow such an automatic update system based on Internet of things to expand. First it elaborated on the main motive of this problem, found three existing related works and three security methods for communication to analyze. Then combined results of analysis, put forward own a secure automatic update solution: manager and devices connect and mutual authentication in real time, at the same time, the manager will regularly check the database to see if there is new version application. When the administrator uploads a new version, the manager will download the version and then sends to all devices, then device installs and finally restart itself. Next, the report described how to implement this system in detail and evaluated it. In the end, this report summarized and introduces the future work.

In this report, the development and implementation of a desktop user interface framework is presented. It is built using web technologies and the Javascript framework React together with a web socket server to render the graphical user interface in an OpenGL environment. This is done by using the open-source framework Chromium Embedded Framework (CEF). The resulting framework and implementation has proven successful, with promising results both from a performance perspective and from a development rapidness perspective.

The topic of this thesis is the design of a testing device for checking electrical car sockets according customers’ requirements. The electrical socket shall be tested by electrical, mechanical and camera tests. The diploma thesis is divided into two main parts, first is a part describing the basic elements in the construction of electric vehicles, and describing types of electric sockets in electric vehicles, and second, a practical part describing the design of a testing device.

No description available.

No description available.