The use of gestures in human-computer interaction have been widely accepted as a powerful tool in... more The use of gestures in human-computer interaction have been widely accepted as a powerful tool in modeling, analysis and gesture recognition research. In recent years, several new ways of interaction with computers were created, including those involving computer vision, pattern recognition and artificial intelligence. The present work develops a model based on motion controlled by primitive movement gestures, used by a human actor in front of a camera to move a virtual character, also known as avatar, inside a virtual environment
The teaching–learning process, at each educational level, is often an open problem for educators ... more The teaching–learning process, at each educational level, is often an open problem for educators and researchers related to the stated topic. Researchers combine emerging technologies to formulate learning tools in order to understand the abstract contents of the subjects; however, the problem still persists. A technological learning tool would be effective when projected into an educational model that looks at motivation, usability, engagement, and technological acceptability. Some of these aspects could be attributed through the use of augmented reality and games. The aim of this work is to analyze, in the literature, the trends of learning models based on computer technologies for an effective and enjoyable learning activity. The analysis of the literature in that context—emphasizing acceptability, categories, entertainment, educational models—shows that it is still not well explored.
Speech is the primary form of communication between human beings. By talking to others we allow t... more Speech is the primary form of communication between human beings. By talking to others we allow them to know our thoughts, feelings, needs and also come to know their feelings, thoughts and needs. This form of human communication is still a dream if we compare it to man-machine communication. The motivating factor for research in this area was the possibility of developing a speech recognition system that did not require any type of learning for their use, allowing that anyone could manipulate the system through speech, since the speech is the more natural medium for human communication. This work aims to build a game for discovery of colors using speech for recognition, this system will serve as a basis for future work on speech recognition as the more traditional techniqueswere applied in these systems. The recognition system developed was applied to the recognition of isolated words withspeaker dependency and runs on mobile devices with Android operating system
The use of geometric techniques and concepts in combination with multi-variate statistical techni... more The use of geometric techniques and concepts in combination with multi-variate statistical techniques for the analysis of variation has been a major advance for the statistical analysis of shape during the last decade. Fundamental to the formalism of what has become known as geometric morphometrics, we find a Riemannian shape manifold with a particular metric called Procrustes distance. This metric measures shape differences in configurations of reference points, represented by sets of rectangular coordinates. The use of Procrustes distances in substitution to regular sums of squares in general linear models is a established procedure of the morphometric toolkit. In this paper, we review the geometric formalism and propose the application of Procrustes dis-tances as replacement for parameters in quantitative genetic models for the assessment of evolutionary processes influencing biological shape changes. A biological case study is examined, where conflicting hypotheses of natural se...
The geometric methods for the statistical analysis of biological shape have traditionally been ba... more The geometric methods for the statistical analysis of biological shape have traditionally been based on landmarks: points of reference in a biological struc-ture that presented a degree of correspondence (or homology) within and across samples. After the morphometric synthesis and the geometric "revolu-tion" in morphometrics, the contours of biological structures were considered unsatisfactory for bio-logical purposes, because the coordinates of points along the outline of an object lack the biological cor-respondence of landmarks. A recent development was the algorithm of spline relaxation or sliding semilandmarks (points of reference along a shape outline without known correspondence within and across samples) that allows one to incorporate out-line information by defining directions (tangents to the outline) along which the contour points can be slid in order to reduce the bending energy crite-rion of the thin plate spline. After filtering out the tangential differences...
A determinacao de pontos de intersecao e contatos entre fronteiras de objetos naoe uma tarefa sim... more A determinacao de pontos de intersecao e contatos entre fronteiras de objetos naoe uma tarefa simples. Uma forma de facilitar essa operacao usa-se estruturas hierarquicas para issolar rapidamente os pedacos de segmentos em poss´ivel intersecao, para finalmente se com- putar localmente os pontos de contato. Neste trabalho formula-se um novo metodo de representacao em estrutura hierarquica de caixas ori- entadas
The determination of intersection or contact points between objects in interference is not a simp... more The determination of intersection or contact points between objects in interference is not a simple task. It could be time-consuming in a computer application. Generally, some real time applications use sophisticated algorithms based on hierarchical structure to isolate the segments of contours of objects in interference, to finally compute locally the contact points. Therefore, we are interested in search for the best way of constructing hierarchical structures bounding objects that allows us to quickly isolate the contour of segments in interference. To achieve that, the bounding must be adapted and fitted to the segments of the objects contours. In this work, we formulate a method to represent, in hierarchic structure, oriented rectangle boxes involving segments of object contours defined by closed cubical B-splines curves. Each oriented box is computed in adapted and fitted form to the segments of the contour by using the second order statistical indicator on some elements of th...
Consider developing safety critical systems is a very complex problem yet. Consider safety aspect... more Consider developing safety critical systems is a very complex problem yet. Consider safety aspects in requirements engineering can be an interesting solution. The aim of this paper is to present a methodology of requirements elicitation to development of security computer systems based in aspect-oriented technique. Is show the concepts of requirements engineering, security, requirements domain and aspects and also is shown some examples on how to use this methodology
The use of gestures in human-computer interaction have been widely accepted as a powerful tool in... more The use of gestures in human-computer interaction have been widely accepted as a powerful tool in modeling, analysis and gesture recognition research. In recent years, several new ways of interaction with computers were created, including those involving computer vision, pattern recognition and artificial intelligence. The present work develops a model based on motion controlled by primitive movement gestures, used by a human actor in front of a camera to move a virtual character, also known as avatar, inside a virtual environment
The teaching–learning process, at each educational level, is often an open problem for educators ... more The teaching–learning process, at each educational level, is often an open problem for educators and researchers related to the stated topic. Researchers combine emerging technologies to formulate learning tools in order to understand the abstract contents of the subjects; however, the problem still persists. A technological learning tool would be effective when projected into an educational model that looks at motivation, usability, engagement, and technological acceptability. Some of these aspects could be attributed through the use of augmented reality and games. The aim of this work is to analyze, in the literature, the trends of learning models based on computer technologies for an effective and enjoyable learning activity. The analysis of the literature in that context—emphasizing acceptability, categories, entertainment, educational models—shows that it is still not well explored.
Speech is the primary form of communication between human beings. By talking to others we allow t... more Speech is the primary form of communication between human beings. By talking to others we allow them to know our thoughts, feelings, needs and also come to know their feelings, thoughts and needs. This form of human communication is still a dream if we compare it to man-machine communication. The motivating factor for research in this area was the possibility of developing a speech recognition system that did not require any type of learning for their use, allowing that anyone could manipulate the system through speech, since the speech is the more natural medium for human communication. This work aims to build a game for discovery of colors using speech for recognition, this system will serve as a basis for future work on speech recognition as the more traditional techniqueswere applied in these systems. The recognition system developed was applied to the recognition of isolated words withspeaker dependency and runs on mobile devices with Android operating system
The use of geometric techniques and concepts in combination with multi-variate statistical techni... more The use of geometric techniques and concepts in combination with multi-variate statistical techniques for the analysis of variation has been a major advance for the statistical analysis of shape during the last decade. Fundamental to the formalism of what has become known as geometric morphometrics, we find a Riemannian shape manifold with a particular metric called Procrustes distance. This metric measures shape differences in configurations of reference points, represented by sets of rectangular coordinates. The use of Procrustes distances in substitution to regular sums of squares in general linear models is a established procedure of the morphometric toolkit. In this paper, we review the geometric formalism and propose the application of Procrustes dis-tances as replacement for parameters in quantitative genetic models for the assessment of evolutionary processes influencing biological shape changes. A biological case study is examined, where conflicting hypotheses of natural se...
The geometric methods for the statistical analysis of biological shape have traditionally been ba... more The geometric methods for the statistical analysis of biological shape have traditionally been based on landmarks: points of reference in a biological struc-ture that presented a degree of correspondence (or homology) within and across samples. After the morphometric synthesis and the geometric "revolu-tion" in morphometrics, the contours of biological structures were considered unsatisfactory for bio-logical purposes, because the coordinates of points along the outline of an object lack the biological cor-respondence of landmarks. A recent development was the algorithm of spline relaxation or sliding semilandmarks (points of reference along a shape outline without known correspondence within and across samples) that allows one to incorporate out-line information by defining directions (tangents to the outline) along which the contour points can be slid in order to reduce the bending energy crite-rion of the thin plate spline. After filtering out the tangential differences...
A determinacao de pontos de intersecao e contatos entre fronteiras de objetos naoe uma tarefa sim... more A determinacao de pontos de intersecao e contatos entre fronteiras de objetos naoe uma tarefa simples. Uma forma de facilitar essa operacao usa-se estruturas hierarquicas para issolar rapidamente os pedacos de segmentos em poss´ivel intersecao, para finalmente se com- putar localmente os pontos de contato. Neste trabalho formula-se um novo metodo de representacao em estrutura hierarquica de caixas ori- entadas
The determination of intersection or contact points between objects in interference is not a simp... more The determination of intersection or contact points between objects in interference is not a simple task. It could be time-consuming in a computer application. Generally, some real time applications use sophisticated algorithms based on hierarchical structure to isolate the segments of contours of objects in interference, to finally compute locally the contact points. Therefore, we are interested in search for the best way of constructing hierarchical structures bounding objects that allows us to quickly isolate the contour of segments in interference. To achieve that, the bounding must be adapted and fitted to the segments of the objects contours. In this work, we formulate a method to represent, in hierarchic structure, oriented rectangle boxes involving segments of object contours defined by closed cubical B-splines curves. Each oriented box is computed in adapted and fitted form to the segments of the contour by using the second order statistical indicator on some elements of th...
Consider developing safety critical systems is a very complex problem yet. Consider safety aspect... more Consider developing safety critical systems is a very complex problem yet. Consider safety aspects in requirements engineering can be an interesting solution. The aim of this paper is to present a methodology of requirements elicitation to development of security computer systems based in aspect-oriented technique. Is show the concepts of requirements engineering, security, requirements domain and aspects and also is shown some examples on how to use this methodology
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Papers by Luis Rivera