Papers by Antonio Carlos Sementille
This paper describes a method for the evaluation of pavement condition through artificial neural ... more This paper describes a method for the evaluation of pavement condition through artificial neural networks using the MLP backpropagation technique. Two of the most used procedures for detecting the pavement conditions were applied: the 'overall severity index' and the 'irregularity index.' Tests with the model demonstrated that the simulation with the neural network gives better results than the procedures recommended by the highway officials. This network may also be applied for the construction of a graphic computer environment.
This article presents the implementation of a distributed system of virtual reality, through the ... more This article presents the implementation of a distributed system of virtual reality, through the integration of services offered by the CORBA platform (Common Object Request Broker Architecture) and by the environment of development of 3D graphic applications in real time, the WorldToolkit, of Sense8. The developed application for the validation of this integration is that of a virtual city, with an emphasis on its traffic ways, vehicles (movable object) and buildings (immovable objects). In this virtual world, several users can interact, each one controlling his/her own car. Since the modeling of the application took into consideration the criteria and principles of the Transport Engineering, the aim is to use it in the planning, project and construction of traffic ways for vehicles. The system was structured according to the approach client/server utilizing multicast communication among the participating nodes. The chosen implementation for the CORBA was the Iona's ORBIX software. The performance results obtained are presented and discussed in the end.
Clei Electronic Journal, 1999
This paper exhibits the use of existing software bus technology in interconnecting Virtual-Realit... more This paper exhibits the use of existing software bus technology in interconnecting Virtual-Reality Environment (VE) software. Interoperability and application construction from heterogeneous modules are well-explored topics of distributed systems. A joint project using the Polylith software bus from the University of Maryland and VE software from the UNC graphics lab has shown the utility of composing existing applications as opposed to making extensive individual modifications. This paper claims only a unique application of these methods to a new client area. Multi-user VE walkthroughs (software navigators) are an exciting new area in graphics software but we see that with the rapid development of graphics technology, next-generation applications (including multiuser systems) are commonly redesigned from the ground up. Here we see an excellent opportunity to examine module reusability, with proven software, in a new application area. As well, we hope our experiments will likely lead to conclusions about VE programming abstractions and produce development methods for making easily interoperable next-generation VE applications.
This paper focuses on the use of the CORBA (Common Object Request Broker Architecture) platform a... more This paper focuses on the use of the CORBA (Common Object Request Broker Architecture) platform as a middleware layer to support distributed virtual environments, particularly those based on the WorldToolKit software. Some results of an application implemented by using the ILU (InterLanguage Unification) software that is compatible with the CORBA platform, are also discussed
... Simone Garçon dos Santos 1,4 Claudio Kirner 1,4 ... With the WTK, packages from a given machi... more ... Simone Garçon dos Santos 1,4 Claudio Kirner 1,4 ... With the WTK, packages from a given machine are multicasted to the others using the UDP protocol with a D-class internet address instead of using peer-to-peer communications with the TCP protocol (Figure 1). In this support ...
This article presents a support on the remote interaction for utilization in augmented reality sy... more This article presents a support on the remote interaction for utilization in augmented reality systems based on ARToolkit. It utilizes the multicast communication in order to improve the scalability of distributed environment. This support may be utilized in production of specific applications pointed to distance education, training and entertainment. The validity of support happened with the implementation of a prototype
This article presents a support on the remote interaction for utilization in augmented reality sy... more This article presents a support on the remote interaction for utilization in augmented reality systems based on ARToolkit. It utilizes the multicast communication in order to improve the scalability of distributed environment. This support may be utilized in production of specific applications pointed to distance education, training and entertainment. The validity of support happened with the implementation of a prototype
Page 1. Short Paper Copyright © 2004 by the Association for Computing Machinery, Inc. Permission ... more Page 1. Short Paper Copyright © 2004 by the Association for Computing Machinery, Inc. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies ...
Abstract This work uses Virtual Reality and Distributed Systems concepts to develop a low cost Di... more Abstract This work uses Virtual Reality and Distributed Systems concepts to develop a low cost Distributed Virtual Environment to visualize and analyze protein molecules called JVRMol. The system has been implemented using Java™ programming language, ...
... Claudia Beatriz Berti1 ... The SPIRE (Spatial Paradigm For Information Retriever and Explorat... more ... Claudia Beatriz Berti1 ... The SPIRE (Spatial Paradigm For Information Retriever and Exploration) uses different visual metaphors like Relevance Spaces, Information Galaxies or Them escapes in order to visualize document collections or results from data base retrieval ...
Abstract This article describes a technique ,for Large Scale Virtual Environments (LSVEs) partiti... more Abstract This article describes a technique ,for Large Scale Virtual Environments (LSVEs) partitioning in hexagon ,cells and using portal in the cell interfaces to reduce,the number,of messages,on the network ,and ,the complexity ,of the ,virtual world. These environments usually demand,a high,volume,of data that must be sent only to those users who needs the information [Greenhalgh, Benford 1997]. CRCategories: [System, Architecture and Environment in Virtual-Reality Continuum]: ,Large-scale ,Simulation. [Applications]: Other Applicationsof Virtual-Reality Continuum. Keywords: Large Scale Virtual Environments, Distributed Virtual Environments, Area of Interest Manager, Networked Virtual Environment, Cell Interface.
The communication between user and software is a basic stage in any Interac-tion System project. ... more The communication between user and software is a basic stage in any Interac-tion System project. In interactive systems, this communication is established by the means of a graphical interface, whose objective is to supply a visual rep-resentation of the main entities and functions present in the Virtual Environ-ment. New ways of interacting in computational systems have been minimizing the gap in the relationship between man and computer, and therefore enhancing its usability. The objective of this paper, therefore, is to present a proposal for a non-conventional user interface library called ARISupport, which supplies AR-ToolKit applications developers with an opportunity to create simple GUI interfaces, and provides some of the functionality used in Augmented Reality systems.
This article describes a technique for Large Scale Virtual Environment (LSVEs) partitioning in he... more This article describes a technique for Large Scale Virtual Environment (LSVEs) partitioning in hexagon cells and using portal in the cell interfaces to reduce the number of messages on the network and the complexity of the virtual world. These environments usually demand a high volume of data that must be sent only to those users who needs the information.
A classic problem in the development of mixed reality systems is the registration. The correct al... more A classic problem in the development of mixed reality systems is the registration. The correct alignment between virtual objects and the real elements is extremely important for the coherent composition of the resultant scene. Considering this context, this paper describes an approach for the composition of scenes in mixed reality environments using the chromakey technique for the extraction of real objects. After that, the scene is mounted in a coherent way related to the depth in OpenGL framebuffer for posterior rendering.
Augmented Reality (AR) systems which use optical tracking with fiducial marker for registration h... more Augmented Reality (AR) systems which use optical tracking with fiducial marker for registration have had an important role in popularizing this technology, since only a personal computer with a conventional webcam is required. However, in most these applications, the virtual elements are shown only in the foreground a real element does not occlude a virtual one. The method presented enables AR environments based on fiducial markers to support mutual occlusion between a real element and many virtual ones, according to the elements position (depth) in the environment.
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Papers by Antonio Carlos Sementille