2014
Authors
Domingues, MA; Soares, C; Jorge, AM; Rezende, SO;
Publication
J. Braz. Comput. Soc.
Abstract
Background: Due to the constant demand for new information and timely updates of services and content in order to satisfy the user’s needs, web site automation has emerged as a solution to automate several personalization and management activities of a web site. One goal of automation is the reduction of the editor’s effort and consequently of the costs for the owner. The other goal is that the site can more timely adapt to the behavior of the user, improving the browsing experience and helping the user in achieving his/her own goals. Methods: A database to store rich web data is an essential component for web site automation. In this paper, we propose a data warehouse that is developed to be a repository of information to support different web site automation and monitoring activities. We implemented our data warehouse and used it as a repository of information in three different case studies related to the areas of e-commerce, e-learning, and e-news. Result: The case studies showed that our data warehouse is appropriate for web site automation in different contexts. Conclusion: In all cases, the use of the data warehouse was quite simple and with a good response time, mainly because of the simplicity of its structure.
2014
Authors
Xiao, XH; Peng, MF; Cardoso, JS; Wang, L; Shen, ME;
Publication
EXPERT SYSTEMS WITH APPLICATIONS
Abstract
The signal of the wireless sensor network in grounding grid, owing to energy loss, network congestion, path constraints and other factors, is easy to delay even partially losing. In order to ensure that the signal can be transmitted effectively in grounding grids for the substation, this paper presents a method based on traffic model of back-off balanced multiple sensor network cooperation model. As we all know, cognitive radio (CR) technology is adopted in multi-channel wireless networks to provide enough channels for data transmission. The MAC protocols should enable the secondary users to maintain the accurate channel state information to identify and utilize the leftover frequency spectrum in a way that constrains the level of interference to the primary users. We proposed a novel cooperation spectrum sensing scheme in which the secondary users adopt backoff-based sensing policy based on the traffic model of the primary users to maximum the throughput of the network. To obtain the full accurate information of the spectrum is a difficult task so that we propose the backoff sensing as a sub-optimal strategy. Since the secondary users sense only a subset of the channels in our proposed scheme, less time is spent to get the channel state information as more time is saved for the data transmission. And while dealing the signal data, I combine the intensity transfer method instead of the priority method. This can effectively reduce the network congestion, to ensure that the main information can be transfer well. It is also very useful to signal transmission for the Multi-sensor in Substations Grounding Grid (SGG).
2014
Authors
Passos, DJ; Silva, SO; Marques, MB; Frazao, O;
Publication
23RD INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS
Abstract
This work presents a demonstration of the potential of fiber cavity ring-down for remote sensing, by using an OTDR to send impulses down similar to 20 km of optical fiber at the end of which the fiber ring cavity was placed. The OTDR showed almost no losses in the fiber, so other ring-down cavities could be spliced along the same fiber. To study the sensitivity of the cavity ring an intensity sensor based on a taper was placed in the ring and glued to a translation stage. A displacement of the stage imposes a curvature on the taper and an associated loss. The configuration had a sensitivity of (11.8 +/- 0.5) mu s/mm.
2014
Authors
Ferreira, M; Costa, P; Rocha, L; Moreira, AP; Pires, N;
Publication
2014 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA)
Abstract
This paper presents a new marker for robot programming by demonstration through motion imitation. The device is based on high intensity LEDs (light emission diodes) which are captured by a pair of industrial cameras. Using stereoscopy, the marker supplies 6-DoF (degrees of freedom) human wrist tracking with both position and orientation data. We propose a robust technique for camera and stereo calibration which maps camera coordinates directly into the desired robot frame, using a single LED. The calibration and tracking procedures are thoroughly described. The tests show that the marker presents a new robust, accurate and intuitive method for industrial robot programming. The system is able to perform in real-time and requires only a single pair of industrial cameras though more can be used for improved effectiveness and accuracy.
2014
Authors
da Silva, JR; Castro, JA; Ribeiro, C; Honrado, J; Lomba, A; Gonçalves, J;
Publication
ON THE MOVE TO MEANINGFUL INTERNET SYSTEMS: OTM 2014 WORKSHOPS
Abstract
Managing research data often requires the creation or reuse of specialised metadata schemas to satisfy the metadata requirements of each research group. Ontologies present several advantages over metadata schemas. In particular, they can be shared and improved upon more easily, providing the flexibility required to establish relationships between datasets and concepts from distinct domains. In this paper, we present a preliminary experiment on the use of ontologies for the description of biodiversity datasets. With a strong focus on the dynamics of individual species, species diversity, biological communities and ecosystems, the Predictive Ecology research group of CIBIO has adopted the INSPIRE European recommendation as the primary tool for metadata compliance across its research data description. We build upon this experience to model the BIOME ontology for the biodiversity domain. The ontology combines concepts from INSPIRE, matching them against the ones defined in the Dublin Core, FOAF and CERIF ontologies. Dendro, a prototype for collaborative data description, uses the ontology to provide an environment where biodiversity metadata records are available as Linked Open Data.
2014
Authors
Scotto, MG; Weiss, CH; Silva, ME; Pereira, I;
Publication
JOURNAL OF MULTIVARIATE ANALYSIS
Abstract
This paper introduces new classes of bivariate time series models being useful to fit count data time series with a finite range of counts.. Motivation comes mainly from the comparison of schemes for monitoring tourism demand, stock data, production and environmental processes. All models are based on the bivariate binomial distribution of Type II. First, a new family of bivariate integer-valued GARCH models is proposed. Then, a new bivariate thinning operation is introduced and explained in detail. The new thinning operation has a number of advantages including the fact that marginally it behaves as the usual binomial thinning operation and also that allows for both positive and negative cross-correlations. Based upon this new thinning operation, a bivariate extension of the binomial autoregressive model of order one is introduced. Basic probabilistic and statistical properties of the model are discussed. Parameter estimation and forecasting are also covered. The performance of these models is illustrated through an empirical application to a set of rainy days time series collected from 2000 up to 2010 in the German cities of Bremen and Cuxhaven.
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