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The Public Transportation System and its operation management require the processing of large amount of data (like bus routes, user data and bus schedules). In particular, origin-destination data serves to indicate citizens’ travel patterns, providing insights related to the dynamic of the urban space occupation. Given this scenario, this paper presents a prototype of origin-destination data visualization, maintaining the spatial and temporal context. The novelty relies on visualization through clustering of georreferenced data, allowing the analysis of different regions of interests (neighborhood, regionals or mathematical regions using K-means algorithm). We demonstrate the prototype through several scenarios, and interviews done to local citizens.Challenges related to meaningful presentation of results are discussed under the perspective of visualization and analytics.

Intel SGX is not accessible from the most privileged execution level, known as ring zero, where the operating system kernel is placed. However, it is possible to split the execution responsibility between kernel and userspace by creating a dependency among these two levels that allow internal kernel data to be stored or processed within SGX private enclaves. In this paper we present SKEEN, an enhanced way to isolate internal operating system components and structures with Intel SGX technology, preventing information leak to different components of the same operating system. A proof-of-concept is provided to exemplify its usage.

Este artigo, aborda o problema de restauração de serviços na nuvem com infraestrutura óptica na presença de falha em um único enlace. O algoritmo proposto, denominado R3D, leva em consideração dois parâmetros especificados em classes de serviço (tolerância ao atraso na restauração e degradação de banda passante) para fazer melhor uso dos recursos ópticos disponíveis durante o processo de restauração. Resultados, obtidos através de simulação, demonstram melhorias significativas na capacidade de restauração de serviços sem impactar de forma negativa a probabilidade de bloqueio.

In this paper, we propose a new restoration algorithm for disaster recovery in Elastic Optical Networks (EONs). The algorithm considers the different requirements on restoration delay and bandwidth degradation while restoring over multiple routes. Furthermore, the algorithm is able to adapt the connection recover process to the post-disaster network conditions and, consequently, increase the number of restored connections. Results indicate that the proposed strategy is able to improve connections restorability and decrease bandwidth blocking probability when compared to restoration approach based on bandwidth degradation and multipath recovery.

All-optical (transparent) wavelength-division multiplexing (WDM), a cost-effective and low power consumption solution for core transport networks, suffers from physical-layer impairments that accumulate along optical paths. In this context, it is important to find dynamic routing schemes with good performance that can consider the optical-layer constraints. In this paper, we propose the alternative least loaded under physical impairments (ALLPI) and the ALLPI with threshold (ALLPI-TH) algorithms. These are heuristic routing methods by which the lightpath requests that cannot be provisioned based on the shortest physical distance are established over least-loaded routes, provided that the selected lightpaths satisfy the impairment constraints (OSNR and PMD). Either dispersion-limited or noise-limited network scenarios were studied, for the bit rate of 40 Gbps. The results indicate that the ALLPI-type algorithms produce significantly lower blocking probabilities when compared to the reference algorithms, especially for a highly-connected network and at higher loads.

Este trabalho apresenta resultados experimentais da avaliação do algoritmo Distributed Network Reachability. DNR é um algoritmo de diagnóstico distribuído em nível de sistema que permite que cada nodo de uma rede particionável de topologia arbitrária determine quais porções da mesma estão atingíveis e inatingíveis. São apresentados extensivos resultados de simulação de eventos dinâmicos de falha e recuperação de nodos e enlaces. São considerados sistemas fortemente dinâmicos, com a ocorrência de eventos modelada por um processo de Poisson. Todos os resultados apresentados têm intervalo de confiança de 95%. Os resultados foram obtidos para grafos aleatórios e também para topologias regulares, como meshes e hipercubos.

The dynamics between technologies and everyday life is increasingly volatile, pushing for greater convenience and ease of both trivial and complex processes. A consequence of the wide implementation of Internet of Things-based devices in smart city applications clearly reflects the mentioned dynamics by the huge amount of data to be handled. To extract useful information from such data, a clever approach to conduct data analysis is the interdisciplinary one, i.e., engineering and computer scientists as close partners of the problem domain experts. This paper addresses IoT data of a Public transportation System (PTS) aiming at contributing to the data analysis process for new insights about bus based PTS applications. Open Data of Curitiba PTS was explored looking for approaches to handle and analyze this kind of data, aiming to find important information for users, managers and planners of the public transport network in Curitiba.