Débora C. Muchaluat-Saade

XConnector: extending XLink to provide multimedia synchronization

This paper proposes XConnector, a language for the creation of complex hypermedia relations with causal or constraint semantics. XConnector allows the definition of relations independently of which resources are related. Another feature is the specification of relation libraries, providing reuse in relationship definition. The main goal is to improve linking languages or the linking modules of hypermedia authoring languages in order to provide multimedia synchronization capabilities using links. Following this direction, an extension to W3C XLink is proposed, incorporating XConnector facilities.

XTemplate 3.0: spatio-temporal semantics and structure reuse for hypermedia compositions

The use of declarative languages in digital TV systems, as well as IPTV systems, facilitates the creation of interactive applications. However, when an application becomes more complex, with many user interactions, for example, the hypermedia document that describes that application becomes bigger, having many lines of XML code. Thus, specification reuse is crucial for an efficient application development process. This paper proposes the XTemplate 3.0 language, which allows the creation of NCL hypermedia composite templates. Templates define generic structures of nodes and links to be added to a document composition, providing spatio-temporal synchronization semantics to it. The use of hypermedia composite templates aims at facilitating the authoring work, allowing the reuse of hypermedia document common specifications. Using composite templates, hypermedia documents become simpler and easier to be created. The 3.0 version of XTemplate adds new facilities to the XTemplate language, such as the possibility of specifying presentation information, the attribution of values to variables and connector parameters during template processing time and the template ability to extend other templates. As an application of XTemplate, this work extends the NCL 3.0 declarative language with XTemplate, adding semantics to NCL contexts and providing document structure reuse. In addition, this paper also presents two authoring tools: the template processor and the wizard to create NCL documents using templates. The wizard tool allows the author to choose a template included in a template base and create an NCL document using that template. The template processor transforms an NCL document using templates into a standard NCL 3.0 document according to digital TV and IPTV standards.

XConnector and XTemplate: improving the expressiveness and reuse in web authoring languages

Abstract Despite recent efforts made by the W3C, web-authoring languages still need to be enhanced. Aiming at this goal, this paper presents proposals for improving their expressiveness and reuse. The proposals are based on an XML language called XConnector, which provides for the creation of complex referential and multimedia synchronization relations. XConnector can be used for improving the expressiveness of either linking languages, such as XLink, or linking modules of hypermedia authoring languages, such as XHTML or SMIL. The novel contribution of this paper is another XML language called XTemplate, which provides for the creation of hypermedia composite templates. A composite template specifies types of components, types of relations, components and relationships that a hypermedia composition has or may have, without identifying what all the components and relationships are. Templates are traditionally used for improving reuse. Composite templates allow the definition of common structures, which can be seen as representing types of compositions with specific semantics given by the set of defined relationships. Therefore, composite templates could be used to provide new time containers in web languages, besides the well known par, seq and exel provided by SMIL 2.0. The paper also presents how composite templates are used in the HyperProp hypermedia system and proposes an extension to XLink to incorporate facilities provided by XConnector and XTemplate, improving its expressiveness and reuse.

Management Issues on Wireless Mesh Networks

Wireless mesh networks (WMN) are emerging as a flexible and low-cost alternative to provide digital inclusion through multi-hop communications, supporting applications from last-mile Internet delivery, search and rescue, home networking to distributed gaming. Managing increasingly large and unplanned WMNs has many challenges. This paper has the primary goal of raising management issues in wireless mesh networks. Furthermore this work documents the management solutions deployed by the ReMesh project 1 in terms of network configuration, topology view, access control, performance measurement and statistics.

IMPROVING THE EXPRESSIVENESS OF XML-BASED HYPERMEDIA AUTHORING LANGUAGES

This paper presents some desirable requirements for hypermedia authoring declarative languages, discussing which ones are satisfied by existent languages, such as SMIL, and which facilities are not offered. It also presents how the missing requirements could be offered in an XML-based language, in order to improve its expressiveness, presenting elements and attributes that could be incorporated in its DTD. Among the facilities, we can highlight the possibility for reusing document components and their presentation characteristics, offering flexibility in temporal duration specifications, adapting a document presentation according to user navigation, and specifying n-ary relationships expressing causality or constraint among components.

NCL4WEB: translating NCL applications to HTML5 web pages

Testing Digital TV applications is not a simple task. DTV applications either need to be transmitted by a TV broadcaster or someone with an equipment capable of generating a DTV signal with the application embedded. Alternatively, an interactive TV application developer may use a virtual execution environment, like a virtual set-top box installed in a computer, which implements the digital TV middleware standard. In both cases, the application usually does not reach a large number of final users, and developers may not be motivated to continue working with digital TV interactive content. On the other hand, HTML5 support for multimedia content will certainly attract multimedia authors to web development. Considering this scenario, this work proposes an alternative way of presenting a digital TV application developed in NCL for the Ginga declarative middleware, translating it into HTML5 web pages, so it can be presented using a common web browser. The translation tool is called NCL4WEB. Like HTML, NCL is XML-based, so NCL4WEB is based on XSLT stylesheets. It transforms NCL elements into HTML5 elements and a set of JavaScript functions that implement synchronization relationships among media objects, including user interaction. Using NCL4WEB, NCL developers are able to publish their interactive TV applications on the web. It is transparent for final users to access HTML5 or NCL content using a web browser.

Towards the convergence between hypermedia authoring languages and architecture description languages

This paper presents a detailed comparison between the structural elements and definitions provided by Hypermedia Authoring Languages and Architecture Description Languages (ADL). ADLs are formal languages that can be used for representing a software architecture. Although it may look trivial to make a direct correspondence between ADL and hypermedia structural entities, such as components to nodes and connectors to links, interesting differences can be identified when observing them more closely. Based on the comparison results, a structural meta-model that can be specialized for use in both domains is proposed. Furthermore, the paper also presents an example of how the meta-model can be used for describing hypermedia document structures, showing how some features found in ADLs can be applied to hypermedia authoring languages. Our final goal is to integrate the contributions of document engineering and software architecture engineering and take advantage of the advances of one area in the other one. The current paper is the first step towards this direction.

Hybrid analysis for indicating patients with breast cancer using temperature time series

Breast cancer is the most common cancer among women worldwide. Diagnosis and treatment in early stages increase cure chances. The temperature of cancerous tissue is generally higher than that of healthy surrounding tissues, making thermography an option to be considered in screening strategies of this cancer type. This paper proposes a hybrid methodology for analyzing dynamic infrared thermography in order to indicate patients with risk of breast cancer, using unsupervised and supervised machine learning techniques, which characterizes the methodology as hybrid. The dynamic infrared thermography monitors or quantitatively measures temperature changes on the examined surface, after a thermal stress. In the dynamic infrared thermography execution, a sequence of breast thermograms is generated. In the proposed methodology, this sequence is processed and analyzed by several techniques. First, the region of the breasts is segmented and the thermograms of the sequence are registered. Then, temperature time series are built and the k-means algorithm is applied on these series using various values of k. Clustering formed by k-means algorithm, for each k value, is evaluated using clustering validation indices, generating values treated as features in the classification model construction step. A data mining tool was used to solve the combined algorithm selection and hyperparameter optimization (CASH) problem in classification tasks. Besides the classification algorithm recommended by the data mining tool, classifiers based on Bayesian networks, neural networks, decision rules and decision tree were executed on the data set used for evaluation. Test results support that the proposed analysis methodology is able to indicate patients with breast cancer. Among 39 tested classification algorithms, K-Star and Bayes Net presented 100% classification accuracy. Furthermore, among the Bayes Net, multi-layer perceptron, decision table and random forest classification algorithms, an average accuracy of 95.38% was obtained.

Geese: A traffic generator for performance and security evaluation of IEC 61850 networks

Automation systems for substations based on IEC 61850 simplify the design, installation, and maintenance of the system with a significant cost reduction. Indeed, the industry considers safety and reliability of real-time systems an essential factor. In this scenario, GOOSE messages used in IEC 61850 communication networks for protection, control, and automation of substation are very important. This paper addresses the development of a traffic generator to adequately evaluate and test system functionalities according to IEC 61850 traffic model. We design and implement Geese, a GOOSE message generator for performance and reliability of IEC 61850 networks evaluation. Generator results are also presented.

Centralized channel allocation algorithm for IEEE 802.11 networks

The sharing of the wireless spectrum is a major concern of network administrators. Access points in the same network interfere with each other, degrading the aggregate performance of stations. Moreover, wireless networks usually coexist with others applications that share the same spectrum and negatively impact the packet transmission. To overcome these issues, we propose the channel allocation algorithm designed for central controllers of infra-structured IEEE 802.11 networks. Our algorithm reduces the interference in controlled access points through the dynamic choice of their operating channels and, unlike other proposals, was designed to operate in a network composed of low cost devices from different brands, and open source software. Furthermore, we also consider the interference caused by unmanaged networks, adjusting the settings of the managed access points according to the wireless environment. The proposal was implemented and evaluated in an open testbed, and the results show that our controller efficiently manages the spectrum with low cost equipment and a low complexity algorithm.