910 resultados para Computer network protocols.
Resumo:
Various physical systems have dynamics that can be modeled by percolation processes. Percolation is used to study issues ranging from fluid diffusion through disordered media to fragmentation of a computer network caused by hacker attacks. A common feature of all of these systems is the presence of two non-coexistent regimes associated to certain properties of the system. For example: the disordered media can allow or not allow the flow of the fluid depending on its porosity. The change from one regime to another characterizes the percolation phase transition. The standard way of analyzing this transition uses the order parameter, a variable related to some characteristic of the system that exhibits zero value in one of the regimes and a nonzero value in the other. The proposal introduced in this thesis is that this phase transition can be investigated without the explicit use of the order parameter, but rather through the Shannon entropy. This entropy is a measure of the uncertainty degree in the information content of a probability distribution. The proposal is evaluated in the context of cluster formation in random graphs, and we apply the method to both classical percolation (Erd¨os- R´enyi) and explosive percolation. It is based in the computation of the entropy contained in the cluster size probability distribution and the results show that the transition critical point relates to the derivatives of the entropy. Furthermore, the difference between the smooth and abrupt aspects of the classical and explosive percolation transitions, respectively, is reinforced by the observation that the entropy has a maximum value in the classical transition critical point, while that correspondence does not occurs during the explosive percolation.
Resumo:
This keynote presentation will report some of our research work and experience on the development and applications of relevant methods, models, systems and simulation techniques in support of different types and various levels of decision making for business, management and engineering. In particular, the following topics will be covered. Modelling, multi-agent-based simulation and analysis of the allocation management of carbon dioxide emission permits in China (Nanfeng Liu & Shuliang Li Agent-based simulation of the dynamic evolution of enterprise carbon assets (Yin Zeng & Shuliang Li) A framework & system for extracting and representing project knowledge contexts using topic models and dynamic knowledge maps: a big data perspective (Jin Xu, Zheng Li, Shuliang Li & Yanyan Zhang) Open innovation: intelligent model, social media & complex adaptive system simulation (Shuliang Li & Jim Zheng Li) A framework, model and software prototype for modelling and simulation for deshopping behaviour and how companies respond (Shawkat Rahman & Shuliang Li) Integrating multiple agents, simulation, knowledge bases and fuzzy logic for international marketing decision making (Shuliang Li & Jim Zheng Li) A Web-based hybrid intelligent system for combined conventional, digital, mobile, social media and mobile marketing strategy formulation (Shuliang Li & Jim Zheng Li) A hybrid intelligent model for Web & social media dynamics, and evolutionary and adaptive branding (Shuliang Li) A hybrid paradigm for modelling, simulation and analysis of brand virality in social media (Shuliang Li & Jim Zheng Li) Network configuration management: attack paradigms and architectures for computer network survivability (Tero Karvinen & Shuliang Li)
Resumo:
Nuestra idea se desarrolla en Internet, donde personas están buscando bienes y servicios para suplir sus necesidades y problemas -- Lo que buscamos es identificar que problemas existen para nichos de mercado específicos a los cuales se les pueda servir por medio de páginas web -- Para cada nicho de mercado pueden existir problemas que no han sido servidos o que están descuidados por otras páginas web dentro de cada nicho que queramos servir -- De acuerdo a nuestra investigación de distintos nichos, buscaremos oportunidades en mercados donde no hayan sido entregadas soluciones por medio de Internet (no hay contenido al respecto o es pobre o encontramos un micro nicho sin atender) -- Nuestra estrategia de éxito es la siguiente: 1 -- Buscar nichos de mercado en Internet cuyas necesidades no hayan sido suplidas por medio de páginas web y donde el contenido que exista no sea muy bueno o se pueden hacer mejoras -- 2 -- Crear una página web con el contenido clave para suplir estas necesidades -- 3 -- Encontrar productos o servicios relacionados y dar una recomendación de compra (por medio de una comparación entre productos, análisis de sus beneficios, testimonios)
Resumo:
Stand-alone and networked surgical virtual reality based simulators have been proposed as means to train surgical skills with or without a supervisor nearby the student or trainee -- However, surgical skills teaching in medicine schools and hospitals is changing, requiring the development of new tools to focus on: (i) importance of mentors role, (ii) teamwork skills and (iii) remote training support -- For these reasons, a surgical simulator should not only allow the training involving a student and an instructor that are located remotely, but also the collaborative training of users adopting different medical roles during the training sesión -- Collaborative Networked Virtual Surgical Simulators (CNVSS) allow collaborative training of surgical procedures where remotely located users with different surgical roles can take part in the training session -- To provide successful training involving good collaborative performance, CNVSS should handle heterogeneity factors such as users’ machine capabilities and network conditions, among others -- Several systems for collaborative training of surgical procedures have been developed as research projects -- To the best of our knowledge none has focused on handling heterogeneity in CNVSS -- Handling heterogeneity in this type of collaborative sessions is important because not all remotely located users have homogeneous internet connections, nor the same interaction devices and displays, nor the same computational resources, among other factors -- Additionally, if heterogeneity is not handled properly, it will have an adverse impact on the performance of each user during the collaborative sesión -- In this document, the development of a context-aware architecture for collaborative networked virtual surgical simulators, in order to handle the heterogeneity involved in the collaboration session, is proposed -- To achieve this, the following main contributions are accomplished in this thesis: (i) Which and how infrastructure heterogeneity factors affect the collaboration of two users performing a virtual surgical procedure were determined and analyzed through a set of experiments involving users collaborating, (ii) a context-aware software architecture for a CNVSS was proposed and implemented -- The architecture handles heterogeneity factors affecting collaboration, applying various adaptation mechanisms and finally, (iii) A mechanism for handling heterogeneity factors involved in a CNVSS is described, implemented and validated in a set of testing scenarios
Resumo:
SQL Injection Attack (SQLIA) remains a technique used by a computer network intruder to pilfer an organisation’s confidential data. This is done by an intruder re-crafting web form’s input and query strings used in web requests with malicious intent to compromise the security of an organisation’s confidential data stored at the back-end database. The database is the most valuable data source, and thus, intruders are unrelenting in constantly evolving new techniques to bypass the signature’s solutions currently provided in Web Application Firewalls (WAF) to mitigate SQLIA. There is therefore a need for an automated scalable methodology in the pre-processing of SQLIA features fit for a supervised learning model. However, obtaining a ready-made scalable dataset that is feature engineered with numerical attributes dataset items to train Artificial Neural Network (ANN) and Machine Leaning (ML) models is a known issue in applying artificial intelligence to effectively address ever evolving novel SQLIA signatures. This proposed approach applies numerical attributes encoding ontology to encode features (both legitimate web requests and SQLIA) to numerical data items as to extract scalable dataset for input to a supervised learning model in moving towards a ML SQLIA detection and prevention model. In numerical attributes encoding of features, the proposed model explores a hybrid of static and dynamic pattern matching by implementing a Non-Deterministic Finite Automaton (NFA). This combined with proxy and SQL parser Application Programming Interface (API) to intercept and parse web requests in transition to the back-end database. In developing a solution to address SQLIA, this model allows processed web requests at the proxy deemed to contain injected query string to be excluded from reaching the target back-end database. This paper is intended for evaluating the performance metrics of a dataset obtained by numerical encoding of features ontology in Microsoft Azure Machine Learning (MAML) studio using Two-Class Support Vector Machines (TCSVM) binary classifier. This methodology then forms the subject of the empirical evaluation.
Resumo:
El presente texto ofrece algunas reflexiones teóricas y visionesdel autor sobre la relación del hombre de hoy con el fenómeno dela comunicación digital, también conocida como comunicaciónvirtual, a través de Internet, unas reflexiones que aparecen deltrabajo investigativo sobre el modelo convergente del canalde televisión pública Telemedellín, y en las que se explora elpanorama de las relaciones del hombre con el otro, consigomismo y con las cosas, desde la mediación de la computadora.Por otro lado, indaga sobre la composición de las redes socialesy su producto, la comunidad virtual, lugar en el que se producenlos intercambios e interrelaciones humanas. Y finalmente,intenta mostrar el desasosiego del hombre de la época actual,encontrándolo como un ser solitario que lucha por un lugar enel mundo.
Resumo:
Este Trabajo Fin de Grado, describe la implantación de un sistema de monitorización de redes informáticas. Se definirán los principales conceptos de monitorización, y se argumentará la elección de la herramienta finalmente seleccionada para llevarlo a cabo. Detallaremos el proceso de instalación, configuración y puesta en producción. Por último, se mostrará cómo funciona el sistema ya instalado sobre la red informática de la Empresa Pública de Turismo Andaluz, S.A., cubriendo las necesidades de control de sistemas desde su sede principal, sita en Málaga, al resto de provincias andaluzas, donde posee diversas sedes secundarias.
Resumo:
Energy efficient policies are being applied to network protocols, devices and classical network management systems. Researchers have already studied in depth each of those fields, including for instance a long monitoring processes of various number of individual ICT equipment from where power models are constructed. With the development of smart meters and emerging protocols such as SNMP and NETCONF, currently there is an open field to couple the power models, translated to the expected behavior, with the realtime energy measurements. The goal is to derive a comparison on the power data between both of the processes in the direction of detection for possible deviations on the expected results. The logical assumption is that a fault in the usage of a particular device will not only increase its own energy usage, but also may cause additional consumption on the other devices part of the network. A platform is developed to monitor and analyze the retrieved power data of a simulated enterprise ICT infrastructure. Moreover, smart algorithms are developed which are aware of the different states that are occurring on each device during their typical use phase, as well as to detect and isolate possible anomalies. The produced results are obtained and validated with the use of Cisco switches and routers, Dell Precision stations and Raritan PDU as part of the monitored infrastructure.
Resumo:
Have been less than thirty years since a group of graduate students and computer scientists working on a federal contract performed the first successful connection between two computers located at remote sites. This group known as the NWG Network Working Group, comprised of highly creative geniuses who as soon as they began meeting started talking about things like intellectual graphics, cooperating processes, automation questions, email, and many other interesting possibilities 1 . In 1968, the group's task was to design NWG's first computer network, in October 1969, the first data exchange occurred and by the end of that year a network of four computers was in operation. Since the invention of the telephone in 1876 no other technology has revolutionized the field of communications over the computer network. The number of people who have made great contributions to the creation and development of the Internet are many, the computer network a much more complex than the phone is the result of people of many nationalities and cultures. However, remember that some years later in 19732 two computer scientists Robert Kahn and Vinton Cerft created a more sophisticated communication program called Transmission Control Protocol - Internet Protocol TCP / IP which is still in force in the Internet today.
Resumo:
Este estudio busca profundizar en los motivadores e inhibidores hacia el uso de una herramienta digital dirigida a jugadores de fútbol no profesional, que permita formar una comunidad para la convocatoria de partidos de dicho deporte, reserva de canchas en línea y reconocimiento del talento de los jugadores -- Se identifica la aceptación de dicha herramienta digital por parte tanto de los jugadores no profesionales como de los negocios de alquiler de canchas sintéticas -- Se aborda el estado del uso de internet y de teléfonos inteligentes en el área metropolitana de Medellín, Colombia, como factores claves de éxito que facilitan la adopción de la herramienta digital evaluada -- Se acudió a la investigación cualitativa de fuentes primarias con entrevistas en profundidad y encuestas, así como a la indagación en fuentes secundarias de la literatura relacionada con la situación en estudio -- El proyecto tuvo la finalidad de determinar si la herramienta digital sería aceptada o no y cuáles serían los contenidos e interacciones deseados por los posibles usuarios
Resumo:
En este trabajo se propone analizar la dinámica del impacto asociado a algunos predictores de la adopción de internet en la ciudad de Medellín (Colombia), utilizando como base de datos la Encuesta de calidad de vida de Medellín (ECV) desde el año 2006 a 2014 -- Se analizarán que variables inciden en la tenencia de internet, se realizará la estadística descriptiva necesaria, y regresiones mediante los modelos Logit y Probit -- El acceso a internet aún se encuentra reservado para una parte privilegiada de la población que cuenta con suficiente ingreso para tener servicio en casa y computador -- Se evidenció igualmente que en la ciudad no hay presencia de brecha de género contrario a lo encontrado en la literatura
Resumo:
En la actualidad, en Colombia el uso de los sitios web en las ONG no se ha generalizado y analizar las razones de ello puede llevar a establecer estrategias de orientación hacia su uso como herramienta de comunicación para sus labores -- El presente estudio se realizó para conocer la disposición de las organizaciones no gubernamentales (ONG) afiliadas a la Federación Antioqueña de ONG (FAONG) localizadas en la ciudad de Medellín hacia el uso de sitios web -- El interés central consistió en encontrar las ventajas y desventajas que las mismas encuentran acerca de la adopción de estar presentes en el canal en línea a través del uso de sitios web -- Para ello se partió de una revisión de antecedentes teóricos que exploran la adopción de herramientas digitales en diferentes empresas, definen las ventajas y desventajas de la presencia en línea y encuentran algunos motivadores e inhibidores y el nivel de conocimiento de las entidades en cuanto al uso de internet como canal de comunicación -- Para lograr el objetivo se hizo un estudio exploratorio en el que se aplicaron instrumentos, como entrevistas y encuestas, a un grupo de informantes seleccionados de ONG afiliadas a la FAONG -- Los hallazgos mostraron el interés de las organizaciones de tener un sitio web para comunicar e informar sobre su objeto social y determinar hacia cuál población están enfocadas; también se encontraron falencias en cuanto al conocimiento, el uso y la comunicación con sus públicos frente al manejo adecuado de un sitio web
Resumo:
Esta pesquisa analisou as oportunidades das mulheres em termos de igualdade na ocupação de cargos de alta chefia na Câmara dos Deputados. A pesquisa de campo foi realizada entre novembro de 2005 e janeiro de 2006 e a amostra abrangeu 1.320 participantes. A Escala de Percepção de Igualdade de Oportunidades entre Mulheres e Homens foi aplicada para analisar a atitude dos servidores quanto a possibilidades e limites de ascensão da mulher na estrutura de cargos da organização. A escala constava de 34 itens, com respostas tipo Likert, e 6 itens sobre dados demográficos. A coleta de dados foi feita pela rede interna de computadores da Câmara dos Deputados, através de e-mail enviado aos 3.597 servidores do quadro efetivo. Os dados foram submetidos à análise dos componentes principais (ACP), rotação promax, com resultados meritórios (KMO = 86,0; Bartlett: 14894,879), para 4 fatores. Observaram-se diferenças entre mulheres e homens quanto aos escores obtidos. As oportunidades de ocupar cargo de alta chefia são menores para elas do que para eles. Há mais gerentes do sexo masculino, e os servidores, especialmente as mulheres que não ocupam posto de chefia, percebem que não há igualdade de oportunidades entre funcionários de ambos os sexos. ___________________________________________________________________________ ABSTRACT
Resumo:
A replicação de base de dados tem como objectivo a cópia de dados entre bases de dados distribuídas numa rede de computadores. A replicação de dados é importante em várias situações, desde a realização de cópias de segurança da informação, ao balanceamento de carga, à distribuição da informação por vários locais, até à integração de sistemas heterogéneos. A replicação possibilita uma diminuição do tráfego de rede, pois os dados ficam disponíveis localmente possibilitando também o seu acesso no caso de indisponibilidade da rede. Esta dissertação baseia-se na realização de um trabalho que consistiu no desenvolvimento de uma aplicação genérica para a replicação de bases de dados a disponibilizar como open source software. A aplicação desenvolvida possibilita a integração de dados entre vários sistemas, com foco na integração de dados heterogéneos, na fragmentação de dados e também na possibilidade de adaptação a várias situações. ABSTRACT: Data replication is a mechanism to synchronize and integrate data between distributed databases over a computer network. Data replication is an important tool in several situations, such as the creation of backup systems, load balancing between various nodes, distribution of information between various locations, integration of heterogeneous systems. Replication enables a reduction in network traffic, because data remains available locally even in the event of a temporary network failure. This thesis is based on the work carried out to develop an application for database replication to be made accessible as open source software. The application that was built allows for data integration between various systems, with particular focus on, amongst others, the integration of heterogeneous data, the fragmentation of data, replication in cascade, data format changes between replicas, master/slave and multi master synchronization.