857 resultados para Internet (Computer networks)
Resumo:
Ethernet está empezando a pasar de las redes de área local a una red de transporte. Sin embargo, como los requisitos de las redes de transporte son más exigentes, la tecnología necesita ser mejorada. Esquemas diseñados para mejorar Ethernet para que cumpla con las necesidades de transporte se pueden categorizar en dos clases. La primera clase mejora solo los componentes de control de Ethernet (Tecnologías basadas en STP), y la segunda clase mejora tanto componentes de control como de encaminamiento de Ethernet (tecnologías basadas en etiquetas). Esta tesis analiza y compara el uso de espacio en las etiquetas de las tecnologias basadas en ellas para garantizar su escalabilidad. La aplicabilidad de las técnicas existentes y los estudios que se pueden utilizar para superar o reducir los problemas de escalabilidad de la etiqueta son evaluados. Además, esta tesis propone un ILP para calcular el óptimo rendimiento de las technologias basadas en STP y las compara con las basadas en etiquetas para ser capaz de determinar, dada una específica situacion, que technologia utilizar.
Resumo:
La asesoría de empresas Ribas Álvarez tiene, actualmente, un problema con la gestión de documentos internos, que se realiza mediante correo interno y una aplicación sencilla de indexación de archivos (HTML); sin ningún tipo de supervisión ni restricción. Esta empresa dispone de un cierto número de trabajadores, los cuales pertenecen a diferentes secciones (privadas o públicas) dentro de la empresa. La información que circula dentro de la empresa, no tiene ningún tipo de seguridad pudiendo cualquier trabajador, disponer de ella aunque no le sea de utilidad. Se quiere crear una aplicación que cumpla con las necesidades que la empresa desea para la administración y gestión de documentos internos, con un control de usuarios y seguridad de acceso a esta aplicación. El objetivo básico de la aplicación seria la creación y gestión de una intranet de control y seguimiento de documentos para una asesoría de empresas
Resumo:
The Mobile Network Optimization (MNO) technologies have advanced at a tremendous pace in recent years. And the Dynamic Network Optimization (DNO) concept emerged years ago, aimed to continuously optimize the network in response to variations in network traffic and conditions. Yet, DNO development is still at its infancy, mainly hindered by a significant bottleneck of the lengthy optimization runtime. This paper identifies parallelism in greedy MNO algorithms and presents an advanced distributed parallel solution. The solution is designed, implemented and applied to real-life projects whose results yield a significant, highly scalable and nearly linear speedup up to 6.9 and 14.5 on distributed 8-core and 16-core systems respectively. Meanwhile, optimization outputs exhibit self-consistency and high precision compared to their sequential counterpart. This is a milestone in realizing the DNO. Further, the techniques may be applied to similar greedy optimization algorithm based applications.
Resumo:
The Bloom filter is a space efficient randomized data structure for representing a set and supporting membership queries. Bloom filters intrinsically allow false positives. However, the space savings they offer outweigh the disadvantage if the false positive rates are kept sufficiently low. Inspired by the recent application of the Bloom filter in a novel multicast forwarding fabric, this paper proposes a variant of the Bloom filter, the optihash. The optihash introduces an optimization for the false positive rate at the stage of Bloom filter formation using the same amount of space at the cost of slightly more processing than the classic Bloom filter. Often Bloom filters are used in situations where a fixed amount of space is a primary constraint. We present the optihash as a good alternative to Bloom filters since the amount of space is the same and the improvements in false positives can justify the additional processing. Specifically, we show via simulations and numerical analysis that using the optihash the false positives occurrences can be reduced and controlled at a cost of small additional processing. The simulations are carried out for in-packet forwarding. In this framework, the Bloom filter is used as a compact link/route identifier and it is placed in the packet header to encode the route. At each node, the Bloom filter is queried for membership in order to make forwarding decisions. A false positive in the forwarding decision is translated into packets forwarded along an unintended outgoing link. By using the optihash, false positives can be reduced. The optimization processing is carried out in an entity termed the Topology Manger which is part of the control plane of the multicast forwarding fabric. This processing is only carried out on a per-session basis, not for every packet. The aim of this paper is to present the optihash and evaluate its false positive performances via simulations in order to measure the influence of different parameters on the false positive rate. The false positive rate for the optihash is then compared with the false positive probability of the classic Bloom filter.
Resumo:
The pervasive and ubiquitous computing has motivated researches on multimedia adaptation which aims at matching the video quality to the user needs and device restrictions. This technique has a high computational cost which needs to be studied and estimated when designing architectures and applications. This paper presents an analytical model to quantify these video transcoding costs in a hardware independent way. The model was used to analyze the impact of transcoding delays in end-to-end live-video transmissions over LANs, MANs and WANs. Experiments confirm that the proposed model helps to define the best transcoding architecture for different scenarios.
Resumo:
Bakgrund: Diabetes Mellitus är kronisk sjukdom som är kopplat till lidande och förlust av livskvalitet. Egenvård är avgörande för att minska de negativa konsekvenserna. Mindre än hälften av alla diabetespatienter uppnår god egenvård. Anledningen är bland annat begränsad kunskap om diabetes och bristande egenvårdsföljsamhet. Införandet av Informations- och kommunikationsteknologi i diabetesvården påbörjades för att förbättra det kliniska resultatet och livskvaliteten för patienter med diabetes typ 2. Syfte: Att beskriva hur information och kommunikationsteknologi kan främja egenvård på distans för patienter med diabetes mellitus typ 2. Metod: Litteraturstudie, där artiklarna söktes i CINAHL, PubMed och Web of Science. Artiklarna som inkluderades var 15 artiklar med kvantitativ, kvalitativ samt mixed metod. Resultat: Resultatet visade att Information och kommunikationsteknologi såsom internet, dator och mobiltelefonbaserade egenvårdsprogram främjade egenvård hos patienter med diabetes typ 2 genom ökad kunskap, ökad medvetenhet, ökad motivation samt förbättrad livsstilsförändring i kost och motion. Slutsats: IKT som hjälpmedel kan underlätta dagliga utmaningarna för patienter med diabetes typ 2 eftersom den täcker kunskapsluckan och därtill ökar patienternas medvetenhet och motivation till egenvård.
Resumo:
The aim of this dissertation is to study the relation between information technology (IT) and organizational management models by defining the manner in which IT can contribute to their transformation. This study is based on a theoretical reference framework which describes the evolution of the extent and functionality of the use of information technology as a tool for business management, with especial emphasis on the development of the capacity of data and Internet communication networks to establish connections among people, companies and communities. The theoretical reference framework also presents different approaches on how to enhance alignment between information technology and organizational management models, taking into account formal aspects related to the detailing of organizational and technical requisites and social implications concerning the introduction of innovations in previously established cultural environments. The study also contains an empirical section based on a case study on the State of Rio de Janeiro Traffic Department (DETRAN-RJ) in which some of the concepts and methods of approach described in the theoretical reference framework were employed. Keywords: Logistic Services Chain, E-Government, Management Model, Organizational Network, Information Technology
Resumo:
Esse estudo objetiva compreender porque as empresas, no Brasil, decidem investir em redes sociais na internet. Foram considerados fatores como a evolução da internet e das próprias redes sociais interativas (em especial Twitter, Facebook e YouTube), as rápidas mudanças tecnológicas que ocorrem no ambiente digital e o papel das agências de comunicação no mercado virtual. Nesse contexto, foi possível observar a importância das redes sociais, atualmente, no negócio das empresas. A falta de material acadêmico sobre o assunto fez com que a visita e a coleta de materiais em diversos websites fossem um recurso complementar valioso. Adicionalmente, com o foco no cenário brasileiro, foram realizadas entrevistas qualitativas semiestruturadas, com 11 gestores de empresas e três gestores de agências de comunicação, o que propiciou um mapeamento das motivações para a utilização das redes sociais pelas empresas, assim como o levantamento de outras informações valiosas para esse trabalho. O referencial teórico buscou contextualizar um panorama privilegiado nesse estudo, considerando o ambiente dinâmico da internet, as redes sociais interativas e seu valor, a mobilidade de acesso, e as agências de publicidade e redes sociais. Além dos resultados apresentados nesse estudo, as revelações de campo e suas discussões propiciaram a elaboração de uma tabela de grau de maturidade social em relação ao momento em que as empresas estão no âmbito digital, assim como o desenvolvimento de um modelo de aprendizagem organizacional no ambiente virtual para redes sociais. Finalmente, foram apresentadas as conclusões, assim como as considerações finais. O estudo demonstrou a importância das redes sociais no cotidiano das empresas e a necessidade de estarem presentes no ambiente virtual, já que estão nesse universo mesmo que de maneira passiva. Embora não tenha havido um fator genérico que possa ser utilizado como padrão motivacional para o investimento inicial nas redes sociais, a visibilidade da exposição da marca nesse meio, seguida pela necessidade de criar um canal de relacionamento com o cliente destacaram-se como fatores motivacionais mais relevantes para esse movimento.
Resumo:
This paper is the result of the Masters dissertation studying the role and history of scientific communication, especially the changes that have occurred after the appearance of electronic communication and computer networks. This study showed that hypertext systems are increasingly being used in the scientific and academic world in the production of electronic journals; this makes it possible for the user to rapidly access information in their area. However, these systems need to be improved to help the user during search and access to information. Both printed journals migrating to electronic media, and the exclusively electronic journals should present the current quality indicators. The attempt was made to discover whether characteristics related to printed journals are being maintained in their electronic counterparts. For this, a prototype model was developed to analyze the structure of electronic scientific journals; it composes 14 criteria expressing aspects of quality for these journals. It includes elements of Website Information Architecture and those already in place in printed scientific journals in order to ensure that basic functions - archiving and dissemination - are maintained in electronic publishing. Each criterion consists of variables, which measure the maintenance of these functions both in the migrating printed journals and the exclusively electronic ones. This prototype model was used to analyze Ciência da Informação On-line and DataGramaZero - Revista de Ciência da Informação. Results indicate that this model is able to find out if the basic functions of archiving and dissemination are being maintained in electronic journals. Therefore, its implementation is justified in electronic journals. The model can help librarians, authors, and users of electronic journals to identify quality journals, and assist editors in developing their projects. The material from the study may be included in the preservice and inservice education of Information Science professionals and to support editors of scientific journals.
Resumo:
The increasing of the number of attacks in the computer networks has been treated with the increment of the resources that are applied directly in the active routers equip-ments of these networks. In this context, the firewalls had been consolidated as essential elements in the input and output control process of packets in a network. With the advent of intrusion detectors systems (IDS), efforts have been done in the direction to incorporate packets filtering based in standards of traditional firewalls. This integration incorporates the IDS functions (as filtering based on signatures, until then a passive element) with the already existing functions in firewall. In opposite of the efficiency due this incorporation in the blockage of signature known attacks, the filtering in the application level provokes a natural retard in the analyzed packets, and it can reduce the machine performance to filter the others packets because of machine resources demand by this level of filtering. This work presents models of treatment for this problem based in the packets re-routing for analysis by a sub-network with specific filterings. The suggestion of implementa- tion of this model aims reducing the performance problem and opening a space for the consolidation of scenes where others not conventional filtering solutions (spam blockage, P2P traffic control/blockage, etc.) can be inserted in the filtering sub-network, without inplying in overload of the main firewall in a corporative network
Resumo:
It s notorious the advance of computer networks in recent decades, whether in relation to transmission rates, the number of interconnected devices or the existing applications. In parallel, it s also visible this progress in various sectors of the automation, such as: industrial, commercial and residential. In one of its branches, we find the hospital networks, which can make the use of a range of services, ranging from the simple registration of patients to a surgery by a robot under the supervision of a physician. In the context of both worlds, appear the applications in Telemedicine and Telehealth, which work with the transfer in real time of high resolution images, sound, video and patient data. Then comes a problem, since the computer networks, originally developed for the transfer of less complex data, is now being used by a service that involves high transfer rates and needs requirements for quality of service (QoS) offered by the network . Thus, this work aims to do the analysis and comparison of performance of a network when subjected to this type of application, for two different situations: the first without the use of QoS policies, and the second with the application of such policies, using as scenario for testing, the Metropolitan Health Network of the Federal University of Rio Grande do Norte (UFRN)
Resumo:
New versions of SCTP protocol allow the implementation of handover procedures in the transport layer, as well as the supply of a partially reliable communication service. A communication architecture is proposed herein, integrating SCTP with the session initiation protocol, SIP, besides additional protocols. This architecture is intended to handle voice applications over IP networks with mobility requirements. User localization procedures are specified in the application layer as well, using SIP, as an alternative mean to the mechanisms used by traditional protocols, that support mobility in the network layer. The SDL formal specification language is used to specify the operation of a control module, which coordinates the operation of the system component protocols. This formal specification is intended to prevent ambiguities and inconsistencies in the definition of this module, assisting in the correct implementation of the elements of this architecture