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Publicações

2010

The SmartVision Navigation Prototype for the Blind

Autores
du Buf, JMH; Barroso, J; Rodrigues, JMF; Paredes, H; Farrajota, M; Fernandes, H; Jose, J; Teixeira, V; Saleiro, M;

Publicação
PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON SOFTWARE DEVELOPMENT FOR ENHANCING ACCESSIBILITY AND FIGHTING INFO-EXCLUSION (DSAI 2010)

Abstract
The goal of the project "SmartVision: active vision for the blind" is to develop a small and portable but intelligent and reliable system for assisting the blind and visually impaired while navigating autonomously, both outdoor and indoor. In this paper we present an overview of the prototype, design issues, and its different modules which integrate a GIS with GPS, Wi-Fi, RFID tags and computer vision. The prototype addresses global navigation by following known landmarks, local navigation with path tracking and obstacle avoidance, and object recognition. The system does not replace the white cane, but extends it beyond its reach. The userfriendly interface consists of a 4-button hand-held box, a vibration actuator in the handle of the cane, and speech synthesis. A future version may also employ active RFID tags for marking navigation landmarks, and speech recognition may complement speech synthesis.

2010

Survey on team tracking techniques applied to sports

Autores
Santiago, CB; Sousa, A; Estriga, ML; Reis, LP; Lames, M;

Publicação
IEEE 2010 International Conference on Autonomous and Intelligent Systems, AIS 2010

Abstract
Recent years have brought an increasing interest on analyzing efficiently the performance of sports players during training sessions and games. The information collected from such analysis is very valuable to educators and coaches since it allows them to better understand the difficulties of a trainee, a player or even an entire team and formulate adequate training and strategic plans accordingly. In order to perform this analysis in a consistent and systematic way, sophisticated sensory systems and data processing techniques are needed. This paper presents a survey on relevant work, current techniques and trends on the area of team tracking systems applied to sports. We propose a classification of these systems by distinguishing them into two main categories: intrusive and nonintrusive. Nonintrusive systems are further refined into outdoor and indoor sports applications. The specific characteristics of each system are itemized, including the identification of the strong points and limitations. Finally, the paper highlights some open issues and research opportunities on this area. © 2010 IEEE.

2010

Sequential Pattern Mining in Multi-relational Datasets

Autores
Ferreira, CA; Gama, J; Costa, VS;

Publicação
CURRENT TOPICS IN ARTIFICIAL INTELLIGENCE

Abstract
We present a framework designed to mine sequential temporal patterns from multi-relational databases. In order to exploit logic-relational information without using aggregation methodologies, we convert the multi-relational dataset into what we name a multi-sequence database. Each example in a multi-relational target table is coded into a sequence that combines intra-table and inter-table relational temporal information. This allows us to find heterogeneous temporal patterns through standard sequence miners. Our framework is grounded in the excellent results achieved by previous propositionalization strategies. We follow a pipelined approach, where we first use a sequence miner to find frequent sequences in the multi-sequence database. Next, we select the most interesting findings to augment the representational space of the examples. The most interesting sequence patterns are discriminative and class correlated. In the final step we build a classifier model by taking an enlarged target table as input to a classifier algorithm. We evaluate the performance of this work through a motivating application, the hepatitis multi-relational dataset. We prove the effectiveness of our methodology by addressing two problems of the hepatitis dataset.

2010

Building an Informal Ontology to Support Collaborative Network Operation: A Case Study

Autores
Pereira, C; Sousa, C; Soares, AL;

Publicação
COLLABORATIVE NETWORKS FOR A SUSTAINABLE WORLD

Abstract
Looking at collaborative networks of organizations as social-technical systems, information and knowledge sharing implies sharing a set of common conceptual structures across organizations. Through this paper, we describe a case study on how to construct meaningful collective conceptualizations by means of a new approach based on conceptual blending theory.

2010

Analyzing the Compatibility Between ISA 88 and IEC 61499

Autores
de Sousa, M;

Publicação
2010 IEEE CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA)

Abstract
In the last years many standards have been created for the industrial control domain. Some have found wide adoption in the industiy, while others seem to never leave the stage of a promising technology. An example of the first type is ISA 88, that defines an architectural design for control applications for the batch process industiy. The author is of the opinion that IEC 61499 is an example of the latter. In this paper the author analyzes how the design architecture defined in ISA 88 may be implemented using the programming framework defined in IEC 61499. Even though ISA 88 and IEC 61499 both follow an event based and object-oriented approach, the author uncovers a fundamental constraint of the IEC 61499 related to the dynamic invocation of services from distinct object instances. Without tiying to extend the IEC 61499 standard, two approaches are presented to work around this constraint.

2010

Reusable IP Cores Library for EV Propulsion Systems

Autores
de Castro, R; Araujo, RE; Feitas, D;

Publicação
IEEE INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE 2010)

Abstract
This paper presents a new control chip design, based on Field Programmable Gate Array (FPGA) technology, for multi-motor electric vehicles. The control chip builds around a reusable intellectual property (IP) core, named Propulsion Control System (PCS); which features motor control functions with field orientation methods, and energy loss minimization of induction motors. To reduce the cost, implementation issues related with the limited number of dedicated multipliers were overcome using an efficient computational block, based on resource sharing strategy. Due to the parallel processing offered by FPGAs, the resulting implementation can be effortlessly adapted to different electric vehicles topologies, like single or multi-motor drive. As proof of concept, two prototypes with single and multi-motor configurations were developed with the control chip design implemented in a low cost Xilinx Spartan 3 FPGA. Experimental verification of the energy loss minimization algorithm is provided, showing considerable energy savings (>15%) in low speed conditions and improving the electric vehicle range per charge.

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