Evaluación de ventajas y desventajas de Uber frente al servicio de transporte taxi entre las calles 53 a 45 y las av. Caracas y Séptima

60 p.

An overview of Fog computing and its security issues

Fog computing is a paradigm that extends Cloud computing and services to the edge of the network. Similar to Cloud, Fog provides data, compute, storage and application services to end users. In this article, we elaborate the motivation and advantages of Fog computing and analyse its applications in a series of real scenarios, such as Smart Grid, smart traffic lights in vehicular networks and software defined networks. We discuss the state of the art of Fog computing and similar work under the same umbrella. Distinguished from other reviewing work of Fog computing, this paper further discloses the security and privacy issues according to current Fog computing paradigm. As an example, we study a typical attack, man-in-the-middle attack, for the discussion of system security in Fog computing. We investigate the stealthy features of this attack by examining its CPU and memory consumption on Fog device. In addition, we discuss the authentication and authorization techniques that can be used in Fog computing. An example of authentication techniques is introduced to address the security scenario where the connection between Fog and Cloud is fragile.

The fog computing paradigm: scenarios and security issues

Fog Computing is a paradigm that extends Cloud computing and services to the edge of the network. Similar to Cloud, Fog provides data, compute, storage, and application services to end-users. In this article, we elaborate the motivation and advantages of Fog computing, and analyse its applications in a series of real scenarios, such as Smart Grid, smart traffic lights in vehicular networks and software defined networks. We discuss the state-of-the-art of Fog computing and similar work under the same umbrella. Security and privacy issues are further disclosed according to current Fog computing paradigm. As an example, we study a typical attack, man-in-the-middle attack, for the discussion of security in Fog computing. We investigate the stealthy features of this attack by examining its CPU and memory consumption on Fog device.

Spatial coordinated medium sharing: Optimal access control management in drive-thru internet

Driven by the ever-growing expectation of ubiquitous connectivity and the widespread adoption of IEEE 802.11 networks, it is not only highly demanded but also entirely possible for in-motion vehicles to establish convenient Internet access to roadside WiFi access points (APs) than ever before, which is referred to as Drive-Thru Internet. The performance of Drive-Thru Internet, however, would suffer from the high vehicle mobility, severe channel contentions, and instinct issues of the IEEE 802.11 MAC as it was originally designed for static scenarios. As an effort to address these problems, in this paper, we develop a unified analytical framework to evaluate the performance of Drive-Thru Internet, which can accommodate various vehicular traffic flow states, and to be compatible with IEEE 802.11a/b/g networks with a distributed coordination function (DCF). We first develop the mathematical analysis to evaluate the mean saturated throughput of vehicles and the transmitted data volume of a vehicle per drive-thru. We show that the throughput performance of Drive-Thru Internet can be enhanced by selecting an optimal transmission region within an AP's coverage for the coordinated medium sharing of all vehicles. We then develop a spatial access control management approach accordingly, which ensures the airtime fairness for medium sharing and boosts the throughput performance of Drive-Thru Internet in a practical, efficient, and distributed manner. Simulation results show that our optimal access control management approach can efficiently work in IEEE 802.11b and 802.11g networks. The maximal transmitted data volume per drive-thru can be enhanced by 113.1% and 59.5% for IEEE 802.11b and IEEE 802.11g networks with a DCF, respectively, compared with the normal IEEE 802.11 medium access with a DCF.

Asymptotic throughput capacity analysis of VANETs exploiting mobility diversity

Vehicular ad hoc networks (VANETs) rely on intervehicle relay to extend the communication range of individual vehicles for message transmissions to roadside units (RSUs). With the presence of a large number of quickly moving vehicles in the network, the end-to-end transmission performance from individual vehicles to RSUs through intervehicle relaying is, however, highly unreliable due to the violative intervehicle connectivity. As an effort toward this issue, this paper develops an efficient message routing scheme that can maximize the message delivery throughput from vehicles to RSUs. Specifically, we first develop a mathematical framework to analyze the asymptotic throughput scaling of VANETs. We demonstrate that in an urban-like layout, the achievable uplink throughput per vehicle from vehicle to RSUs scales as Θ(1/ log n) when the number of RSUs scales as Θ(n/log n) with n denoting vehicle population. By noting that the network throughput is bottlenecked by the unbalanced data traffic generated by hotspots of realistic urban areas, which may overload the RSUs nearby, a novel packet-forwarding scheme is proposed to approach the optimal network throughput by exploiting the mobility diversity of vehicles to balance the data traffic across the network. Using extensive simulations based on realistic traffic traces, we demonstrate that the proposed scheme can improve the network throughput approaching the asymptotic throughput capacity.

DESIGN OF EFFICIENT IN-NETWORK DATA PROCESSING AND DISSEMINATION FOR VANETS

By providing vehicle-to-vehicle and vehicle-to-infrastructure wireless communications, vehicular ad hoc networks (VANETs), also known as the “networks on wheels”, can greatly enhance traffic safety, traffic efficiency and driving experience for intelligent transportation system (ITS). However, the unique features of VANETs, such as high mobility and uneven distribution of vehicular nodes, impose critical challenges of high efficiency and reliability for the implementation of VANETs. This dissertation is motivated by the great application potentials of VANETs in the design of efficient in-network data processing and dissemination. Considering the significance of message aggregation, data dissemination and data collection, this dissertation research targets at enhancing the traffic safety and traffic efficiency, as well as developing novel commercial applications, based on VANETs, following four aspects: 1) accurate and efficient message aggregation to detect on-road safety relevant events, 2) reliable data dissemination to reliably notify remote vehicles, 3) efficient and reliable spatial data collection from vehicular sensors, and 4) novel promising applications to exploit the commercial potentials of VANETs. Specifically, to enable cooperative detection of safety relevant events on the roads, the structure-less message aggregation (SLMA) scheme is proposed to improve communication efficiency and message accuracy. The scheme of relative position based message dissemination (RPB-MD) is proposed to reliably and efficiently disseminate messages to all intended vehicles in the zone-of-relevance in varying traffic density. Due to numerous vehicular sensor data available based on VANETs, the scheme of compressive sampling based data collection (CS-DC) is proposed to efficiently collect the spatial relevance data in a large scale, especially in the dense traffic. In addition, with novel and efficient solutions proposed for the application specific issues of data dissemination and data collection, several appealing value-added applications for VANETs are developed to exploit the commercial potentials of VANETs, namely general purpose automatic survey (GPAS), VANET-based ambient ad dissemination (VAAD) and VANET based vehicle performance monitoring and analysis (VehicleView). Thus, by improving the efficiency and reliability in in-network data processing and dissemination, including message aggregation, data dissemination and data collection, together with the development of novel promising applications, this dissertation will help push VANETs further to the stage of massive deployment.

Análisis del tratamiento de la descripción escrita en libros de texto de 1º y de 3º de educación secundaria obligatoria, en el bloque temático de geografía, y su proyección en la formación del profesorado

Enseñar a escribir en cualquier contexto de la sociedad del conocimiento es una tarea de los profesores del siglo XXI. Este planteamiento encierra un nuevo concepto de alfabetización. Aprender a escribir, hoy día, supone algo más que el dominio del código lingüístico; requiere desarrollar la capacidad de expresarse adecuadamente en cualquier ámbito de la sociedad presente. Asimismo, esta tarea se propone como una responsabilidad para todos los profesores de las distintas materias, no como una tarea solo de los docentes dedicados a las áreas lingüísticas. El enfoque que subyace en esta idea se relaciona con una enseñanza que concibe la lengua como instrumento vehicular para el desarrollo del conocimiento. Por su parte, la descripción se presenta como fuente de conocimiento en cualquier ámbito de la vida, hasta tal punto que se podría hablar de que todo aquello que no se ha descrito no se conoce1. Por tanto, enseñar a describir en las distintas asignaturas como medio para desarrollar el propio conocimiento disciplinar, así como para que los alumnos desarrollen sus destrezas escritas en cualquier ámbito, es una llamada urgente de la sociedad actual. Esta tesis se centra en la enseñanza de la descripción escrita en el ámbito disciplinar de la Geografía. Se pretenden explorar las peculiaridades de la Didáctica de la descripción que exige la enseñanza y el aprendizaje de un contenido no lingüístico como es la Geografía...

SEMD: secure and efficient message dissemination with policy enforcement in VANET

Vehicular ad hoc network (VANET) is an increasing important paradigm, which not only provides safety enhancement but also improves roadway system efficiency. However, the security issues of data confidentiality, and access control over transmitted messages in VANET have remained to be solved. In this paper, we propose a secure and efficient message dissemination scheme (SEMD) with policy enforcement in VANET, and construct an outsourcing decryption of ciphertext-policy attribute-based encryption (CP-ABE) to provide differentiated access control services, which makes the vehicles delegate most of the decryption computation to nearest roadside unit (RSU). Performance evaluation demonstrates its efficiency in terms of computational complexity, space complexity, and decryption time. Security proof shows that it is secure against replayable choosen-ciphertext attacks (RCCA) in the standard model.

In the box

In The Box surge como una idea de negocio que parte de la observación diaria con base en el ordenamiento del espacio público de la ciudad de Bogotá. La idea principal del proyecto se basa en el uso de espacios públicos que se encuentran de alguna manera en deterioro por parte de la administración distrital, con el fin de transformar estos espacios en lugares que los ciudadanos puedan aprovechar de una forma más adecuada. En este orden, In The Box propone la utilización de dichos espacios (zonas bajas de los puentes vehiculares) con el fin de ofrecer al cliente una experiencia gastronómica diferente, a través de la adaptación de un restaurante en un contenedor de carga marítima que podrá ser localizado en diferentes partes de la ciudad con base en el concepto on the go; Puesto que gran parte de los capitalinos se encuentran inmersos en una ardua rutina laboral la cual no permite en la mayoría de los casos el tiempo suficiente para ir a comer en un restaurante y obliga a acudir al consumo de productos de comida rápida.

Redes transnacionales en Argentina ¿Un nuevo escenario de crimen organizado en América Latina?(2008-2013)

El desarrollo de este estudio de caso, tiene como objetivo analizar la consolidación de Argentina como un posible escenario de crimen organizado en América Latina. Para ello se analizarán los factores que han permitido la proliferación de dicho fenómeno, haciendo énfasis en que la capacidad de establecer redes, trascienden el ordenamiento estatal y permiten que se desarrolle de manera autónoma en diferentes regiones del planeta. Además se tratarán temas fundamentales que permiten dar cuenta de cómo ha sido la construcción de los pilares que conforman la sociedad argentina en el contexto de una sociedad criminal, convirtiéndose en una amenaza directa para el funcionamiento del sistema internacional.

Trata de mujeres con fines de explotación sexual en el marco de cooperación de Naciones Unidas y su Oficina UNODC. Colombia (2007—2010)

El interés de este caso de estudio es mostrar un diagnóstico sobre la situación de trata de mujeres con fines de explotación sexual en Colombia, basado en el avance de las acciones emprendidas por parte de los Organismos Internacionales y del Estado, durante el periodo comprendido entre los años 2007 y 2010. A partir de lo anterior, se utilizaron tres conceptos claves los cuales fueron: Globalización, Derechos Humanos y Perspectiva de Género con el fin de hacer una descripción del fenómeno de trata en Colombia. Se plantean como propósitos particulares contextualizar el fenómeno de la trata y su impacto a nivel mundial, identificar las políticas del Estado; y finalmente identificar el rol que tuvo la participación de Organización de las Naciones Unidas y su oficina especial UNODC frente al delito de trata de mujeres con fines de explotación sexual en Colombia.

LA IMPORTANCIA DE LOS EJES DE FIJACIÓN DEL PAISAJE URBANO EN LA EDUCACIÓN VIAL

La enseñanza de los ejes de fijación en el espacio urbano son elementos que deben ser vinculados con la educación vial ya que la misma no forma parte del diseño curricular en la educación formal. El propósito del presente trabajo es que a través de la enseñanza de las funciones de las arterias de circulación como calles, avenidas, rutas, autopistas se busca la toma de conciencia de los jóvenes de la importancia de conocer los principios de la educación vial para prevenir los accidentes de tránsito. La metodología utilizada responde al análisis de documentos bibliográficos, entrevistas, interpretación de planos, trabajo de campo, entre otros. Los resultados de esta investigación muestra el interés de los alumnos por conocer las normas de transito para preservar la vida humana, mejorar la circulación vehicular y la del peatón.

Performance of LTE-V2V for Cooperative Awareness

The large scale development of an Intelligent Transportation System is very close. The main component of such a smart environment is the network that provides connectivity for all vehicles. Public safety is the most demanding application because requires a fast, reliable and secure communication. Although IEEE 802.11p is presently the only full wireless standard for vehicular communications, recent advancements in 3GPP LTE provide support to direct communications and the ongoing activities are also addressing the vehicle to vehicle case. This thesis focuses on the resource allocation procedures and performance of LTE-V2V. To this aim, a MATLAB simulator has been implemented and results have been obtained adopting different mobility models for both in-coverage and out-of-coverage scenarios.