Reinaldo Matushima

Multiple personal security domains

Mobility, usability and security are major requirements for any Ad Hoc network systems, and there have been numerous papers in regards to them. However, often these requirements are addressed separately. For a valid solution, these requirements must be considered from an integrated view. In this paper, taking into account mobility and usability, we implement a framework which allows to securely share resources and services between devices in Ad-hoc networks, based on security policies defined by the owners of those devices. In addition, we extend our framework to support inter-domain sharing of services and resources. We detail our design, present the preliminary results of our prototype, and discuss the lessons learned, in particular how user experience led to several re-designs of the initial security solution.

Integrating MPEG-7 descriptors and pattern recognition: an environment for multimedia indexing and searching

This paper describes a music searching system based on an automatic indexing process created over a pattern recognition tool and MPEG-7 standard. We present a complete analysis of the involved technologies integration process and show a reference measure in the feasibility of this kind of application not only in the research environment but also in the production of real systems.

An Overlay Application-Layer Multicast Infrastructure

Overlay networks are considered an easy and effective way to deploy value-added Internet services by extending the best-effort delivery service supported by IP layer. However, a careful design is needed in order to take advantage of these benefits. Since there are no standards for overlay networks yet, they are often independently designed, which means that each one applies its own topology discovery and takes its own routing decisions. As a result, they may negatively affect each other by generating control overhead and by creating bottlenecks in the physical network. In order to avoid such a situation, this work proposes an overlay network organization and architecture towards a middleware for overlay multicast services. As proof of concept, we have deployed a multicast service overlay network taking advantage of this architecture and considering both intradomain and interdomain scenarios – the latter being practically impossible to deploy on public networks due to administrative issues. By experimental measurements, we validate interdomain multicast functionality over four autonomous systems without any native support from underlying networks.

Evaluating the effectiveness of the use of teaching materials in video format in distance learning environments

Projections indicate that video will be responsible for 90% of network traffic until the end of the decade. Considering the high cost of media production and, mainly, the high consumption of network resources for applications that explore it, it will be extremely important to monitor such use, preventing against wrong or distorted views of this consumption. Within this scenario, it is necessary to develop mechanisms and tools that provide a clear vision of video effectiveness consumption, as well as the measuring of “viewer engagement”. What tools can be developed to evaluate such consumption? What should be measured, i.e., which are the parameters and metrics necessary, and how can we obtain them, in order to measure the effectiveness of video applications use, for example in engineering courses and distance learning environments? These are some of the questions considered in this paper, especially evaluated within a scenario of video usage for teaching/learning purpose.

A new approach for video adaptation through overlay services networks

Video adaptation is an extensively explored content providing technique aimed at appropriately suiting several usage scenarios featured by different network requirements and constraints, users terminal and preferences. However, its usage in high-demand video distribution systems, such as CNDs, has been badly approached, ignoring several aspects of optimization of network use. To address such deficiencies, this paper presents an approach for implementing the adaptation service by exploring the concept of overlay services networks. As a result of demonstrate the benefits of this proposal, it is made a comparison of this proposed adaptation service with other strategies of video adaptation.

Towards a middleware reference model for overlay networks

This work proposes a high-level architecture towards a middleware reference model for overlay networks. Such middleware enables support to large-scale advanced network services for multimedia receivers scattered around a wide-area public network, such as the Internet. The idea is to provide services that cannot practically be directly embedded in network layer, such as multicast, security, and QoS, for instance. However, in this paper we focus only on multicast service, considering both intradomain and interdomain scenarios -- the latter being practically impossible to deploy on public networks due to administrative issues. As proof of concept, we have deployed a multimedia system taking advantage of application-level multicast from middleware support. By experimental measurements, we confirm interdomain multicast functionality over four autonomous system without any native support from underlying networks.

A Management Platform for Multimedia Distribution in Country-wide Networks

This paper describes the media distribution management platform designed and developed by LARC/EPUSP as activity of the video management work group. The main project objective was to develop a media delivery management platform including facilities for media storing and distribution management, user access control and multicast. This project was based on open-standard solution, having as target a countrywide IP network. Today, a test version of this tool is integrated to the RNP network for managing the video distribution services network.

Monitoring the video use for learning support

The video consumption tends to grow in coming years and it will be increasingly imperative to know the validity and effectiveness of using this type of media especially in teach and learn activities. It is very important to be able to assess how much knowledge a particular didactic video content was effective in building students knowledge. In this paper we present a tool we developed and an experiment we realized with two classes of computer engineering course related to network computer subjects, totalizing 140 students. In our experiment we divided our students in two groups: half of them attended a video explanation and half of them had the same explanation but only in a traditional classroom format. Our experiments show that video can be a great ally in the teaching and learning processes. Nevertheless, our investigation must continue in order to understand all video potential in this purpose.