Marcelo Campo

An Overview of 3D Software Visualization

Software visualization studies techniques and methods for graphically representing different aspects of software. Its main goal is to enhance, simplify and clarify the mental representation a software engineer has of a computer system. During many years, visualization in 2D space has been actively studied, but in the last decade, researchers have begun to explore new 3D representations for visualizing software. In this article, we present an overview of current research in the area, describing several major aspects like: visual representations, interaction issues, evaluation methods and development tools. We also perform a survey of some representative tools to support different tasks, i.e., software maintenance and comprehension, requirements validation and algorithm animation for educational purposes, among others. Finally, we conclude identifying future research directions.

Easy web service discovery: A query-by-example approach

Web services have acquired enormous popularity among software developers. This popularity has motivated developers to publish a large number of Web service descriptions in UDDI registries. Although these registries provide search facilities, they are still rather difficult to use and often require service consumers to spend too much time manually browsing and selecting service descriptions. This paper presents a novel search method for Web services called WSQBE that aims at both easing query specification and assisting discoverers by returning a short and accurate list of candidate services. In contrast with previous approaches, WSQBE discovery process is based on an automatic search space reduction mechanism that makes this approach more efficient. Empirical evaluations of WSQBE search space reduction mechanism, retrieval performance, processing time and memory usage, using a registry with 391 service descriptions, are presented.

A Survey of Approaches to Web Service Discovery in Service-Oriented Architectures

Discovering services acquires importance as Service-Oriented Computing SOC becomes an adopted paradigm. SOCs most popular materializations, namely Web Services technologies, have different challenges related to service discovery and, in turn, many approaches have been proposed. As these approaches are different, one solution may be better than another according to certain requirements. In consequence, choosing a service discovery system is a hard task. To alleviate this task, this paper proposes eight criteria, based on the requirements for discovering services within common service-oriented environments, allowing the characterization of discovery systems. These criteria cover functional and non-functional aspects of approaches to service discovery. The results of the characterization of 22 contemporary approaches and potential research directions for the area are also shown.

Intelligent assistance for teachers in collaborative e-learning environments

Collaborative learning environments provide a set of tools for students acting in groups to interact and accomplish an assigned task. In this kind of systems, students are free to express and communicate with each other, which usually lead to collaboration and communication problems that may require the intervention of a teacher. In this article, we introduce an intelligent agent approach to assist teachers through monitoring participations made by students within a collaborative distance learning environment, detecting conflictive situations in which a teachers intervention may be necessary. High precision rates achieved on conflict detection scenarios suggest great potential for the application of the proposed rule-based approach for providing personalized assistance to teachers during the development of group works.

Identification of non-functional requirements in textual specifications: A semi-supervised learning approach

Context: Early detection of non-functional requirements (NFRs) is crucial in the evaluation of architectural alternatives starting from initial design decisions. The application of supervised text categorization strategies for requirements expressed in natural language has been proposed in several works as a method to help analysts in the detection and classification of NFRs concerning different aspects of software. However, a significant number of pre-categorized requirements are needed to train supervised text classifiers, which implies that analysts have to manually assign categories to numerous requirements before being able of accurately classifying the remaining ones. Objective: We propose a semi-supervised text categorization approach for the automatic identification and classification of non-functional requirements. Therefore, a small number of requirements, possibly identified by the requirement team during the elicitation process, enable learning an initial classifier for NFRs, which could successively identify the type of further requirements in an iterative process. The goal of the approach is the integration into a recommender system to assist requirement analysts and software designers in the architectural design process. Method: Detection and classification of NFRs is performed using semi-supervised learning techniques. Classification is based on a reduced number of categorized requirements by taking advantage of the knowledge provided by uncategorized ones, as well as certain properties of text. The learning method also exploits feedback from users to enhance classification performance. Results: The semi-supervised approach resulted in accuracy rates above 70%, considerably higher than the results obtained with supervised methods using standard collections of documents. Conclusion: Empirical evidence showed that semi-supervision requires less human effort in labeling requirements than fully supervised methods, and can be further improved based on feedback provided by analysts. Our approach outperforms previous supervised classification proposals and can be further enhanced by exploiting feedback provided by analysts.

Introducing mobile devices into Grid systems: a survey

Mobile device capabilities have been steadily increasing in the past years. Therefore, mobile Grids potential benefits have encouraged research on this topic. Researchers have identified several issues, such as energy consumption and limited resources, that steam from using mobile devices because they are small computers that run on battery and can move outside of the wireless coverage area. This paper analyses these issues discusses proposed solutions to them in the different Grid abstraction levels from Grid fabric layer to Grid user application layer. Finally, we propose a taxonomy that considers the use of mobile devices and discuss future research opportunities.

SmartBooks: a step beyond active-cookbooks to aid in framework instantiation

In this work we present SmartBooks, a new approach to support framework instantiation based on the active cookbook concept, extended with a combination of the concept of user-task modeling and least commitment planning methods. Based on this technique, a tool can present to the developer the different high level activities that can be carried on when creating a new application from a framework, taking as a basis the documentation provided by the designer through instantiation rules. For example, if the framework is in the accounting domain, some of the initial activities may be to create a new type of account, or to describe a new algorithm to calculate the tax rate. For each of these high level activities, there is a list of tasks that the user must carry out in order to complete the activity. When the user selects her next objective, the tool is able to build the sequence of tasks that have to be carried out to accomplish that objective; this list of tasks is called the instantiation plan, and the process of plan creation is named planning. In this paper we present the main characteristics of the planning approach and a example of the instantiation tool being developed.

Towards agent-oriented assistance for framework instantiation

In this work we present a tool for assisting object-oriented framework instantiation based on Intelligent Agent technology. Differently from other approaches, the user is able to select the functionality needed for the new application, and based on this selection an agent elaborates a sequence of programming activities that should be carried out in order to implement it. In addition, the agent guides the execution of the activities according to the framework design. To enable this behavior, the framework need to be documented following the SmartBooks method, which extends traditional framework documentation with instantiation rules. In this paper we present an example of an instantiation environment built based on these ideas and the main characteristics of the SmartBooks method for documenting frameworks through instantiation knowledge rules.

Survey on network-based botnet detection methods

Botnets are an important security problem on the Internet. They continuously evolve their structure, protocols and attacks. This survey analyzes and compares the most important efforts carried out in a network-based detection area. It accomplishes four tasks: first, the comparison of previous surveys and the proposal of four new dimensions to analyze their classification schemes; second, a new classification and comparison of network-based botnet detection proposals, which includes the definition of 20 desired properties of every botnet detection paper; third, an extensive comparison between the most representative detection proposals; and fourth, the description of the most important problems and highlights in the area. We conclude that the area has achieved great advances so far, but there are still many open problems. Copyright

Easy gesture recognition for Kinect

Abstract Recent progress in entertainment and gaming systems has brought more natural and intuitive human–computer interfaces to our lives. Innovative technologies, such as Xbox Kinect, enable the recognition of body gestures, which are a direct and expressive way of human communication. Although current development toolkits provide support to identify the position of several joints of the human body and to process the movements of the body parts, they actually lack a flexible and robust mechanism to perform high-level gesture recognition. In consequence, developers are still left with the time-consuming and tedious task of recognizing gestures by explicitly defining a set of conditions on the joint positions and movements of the body parts. This paper presents EasyGR (Easy Gesture Recognition), a tool based on machine learning algorithms that help to reduce the effort involved in gesture recognition. We evaluated EasyGR in the development of 7 gestures, involving 10 developers. We compared time consumed, code size, and the achieved quality of the developed gesture recognizers, with and without the support of EasyGR. The results have shown that our approach is practical and reduces the effort involved in implementing gesture recognizers with Kinect.