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Publicações

2011

Characterization of optical fiber long period grating refractometer with nanocoating

Autores
Simoes, E; Abe, I; Oliveira, J; Frazao, O; Caldas, P; Pinto, JL;

Publicação
SENSORS AND ACTUATORS B-CHEMICAL

Abstract
In this work is studied the response of optical fiber long period grating (LPG) to changes of the refractive index of the external media relatively to variations of wavelength and in transmission. The response of the LPG to refractive index greater and lesser than to cladding is investigated. A nanolayer was deposited onto the fiber to increase the sensitivity of the LPG to refractive index of the external media higher than cladding. The film modifies the rates of effective modes of cladding, thus improving the response of the changes in the refractive index of the external media higher than that in the refractive index of the cladding (n(cl) approximate to 1.457). The Langmuir-Blodgett technique was used for the deposition of the nanolayer.

2011

Steps to build a thematic repository

Autores
De Castro, AV; De Carvalho, CV; Carrapatoso, E;

Publicação
Proceedings of the 6th Iberian Conference on Information Systems and Technologies, CISTI 2011

Abstract
The achievement of information and knowledge is a common practice of mankind. Thus, the knowledge is preserved and made it transmission to subsequent generations ensuring their own survival and evolution of the human race. With the advent of information produced digitally, it is necessary to ensure new mechanisms for sharing preserve those digital contents in this new "information society". Regarding health, we find that the available repositories are mostly institutional which prevents the submission of digital contents and their preservation by independent professionals, researchers and students who are not part of them. It also denotes that these repositories have a lot of thesis, leaving out other multimedia resources such as images, videos, 3D models, animations, clinical exams, case studies, among others. The creation of a non-institutional thematic repository aims to contribute to a further spread of this type of resources cataloged with metadata in a global level and provide digital preservation thereof. This paper presents the steps for creating a thematic repository for healthcare. © 2011 AISTI.

2011

Process Mining Manifesto

Autores
der Aalst, WMPv; Adriansyah, A; de Medeiros, AKA; Arcieri, F; Baier, T; Blickle, T; Chandra Bose, RPJ; den Brand, Pv; Brandtjen, R; Buijs, JCAM; Burattin, A; Carmona, J; Castellanos, M; Claes, J; Cook, J; Costantini, N; Curbera, F; Damiani, E; Leoni, Md; Delias, P; van Dongen, BF; Dumas, M; Dustdar, S; Fahland, D; Ferreira, DR; Gaaloul, W; Geffen, Fv; Goel, S; Günther, CW; Guzzo, A; Harmon, P; ter Hofstede, AHM; Hoogland, J; Ingvaldsen, JE; Kato, K; Kuhn, R; Kumar, A; Rosa, ML; Maggi, FM; Malerba, D; Mans, RS; Manuel, A; McCreesh, M; Mello, P; Mendling, J; Montali, M; Motahari Nezhad, HR; Muehlen, Mz; Gama, JM; Pontieri, L; Ribeiro, J; Rozinat, A; Pérez, HS; Pérez, RS; Sepúlveda, M; Sinur, J; Soffer, P; Song, M; Sperduti, A; Stilo, G; Stoel, C; Swenson, KD; Talamo, M; Tan, W; Turner, C; Vanthienen, J; Varvaressos, G; Verbeek, E; Verdonk, M; Vigo, R; Wang, J; Weber, B; Weidlich, M; Weijters, T; Wen, L; Westergaard, M; Wynn, MT;

Publicação
Business Process Management Workshops - BPM 2011 International Workshops, Clermont-Ferrand, France, August 29, 2011, Revised Selected Papers, Part I

Abstract
Process mining techniques are able to extract knowledge from event logs commonly available in today's information systems. These techniques provide new means to discover, monitor, and improve processes in a variety of application domains. There are two main drivers for the growing interest in process mining. On the one hand, more and more events are being recorded, thus, providing detailed information about the history of processes. On the other hand, there is a need to improve and support business processes in competitive and rapidly changing environments. This manifesto is created by the IEEE Task Force on Process Mining and aims to promote the topic of process mining. Moreover, by defining a set of guiding principles and listing important challenges, this manifesto hopes to serve as a guide for software developers, scientists, consultants, business managers, and end-users. The goal is to increase the maturity of process mining as a new tool to improve the (re)design, control, and support of operational business processes. © 2012 Springer-Verlag.

2011

Domain-Specific Optimization of Signal Recognition Targeting FPGAs

Autores
Demertzi, M; Diniz, PC; Hall, MW; Gilbert, AC; Wang, Y;

Publicação
ACM TRANSACTIONS ON RECONFIGURABLE TECHNOLOGY AND SYSTEMS

Abstract
Domain-specific optimizations on matrix computations exploiting specific arithmetic and matrix representation formats have achieved significant performance/area gains in Field-Programmable Gate Array (FPGA) hardware designs. In this article, we explore the application of data-driven optimizations to reduce both storage and computation requirements to the problem of signal recognition from a known dictionary. By starting with a high-level mathematical representation of a signal recognition problem, we perform optimizations across the layers of the system, exploiting mathematical structure to improve implementation efficiency. Specifically, we use Walsh wavelet packets in conjunction with a BestBasis algorithm to distinguish between spoken digits. The resulting transform matrices are quite sparse, and exhibit a rich algebraic structure that contains significant overlap across rows. As a consequence, dot-product computations of the transform matrix and signal vectors exhibit significant computation reuse, or repeated identical computations. We present an algorithm for identifying this computation reuse and scheduling of the row computations. We exploit this reuse to derive FPGA hardware implementations that reduce the amount of computation for an individual matrix by as much as 6.35x and an average of 2x for a single dot-product unit. The implementation that exploits reuse achieves a 2x computation reduction compared to three concurrently-executing simpler accumulator units with the same aggregate design area and outperforms software implementations on high-end desktop personal computers.

2011

Leadership model

Autores
Almeida, L; Cruz, J; Ferreira, H; Pinto, AA;

Publicação
Springer Proceedings in Mathematics

Abstract
The Theory of Planned Behavior studies the decision-making mechanisms of individuals. We construct a game theoretical model to understand the role of leaders in decision-making of individuals or groups.We study the characteristics of the leaders that can have a positive or negative influence over others’ behavioral decisions. © Springer-Verlag Berlin Heidelberg 2011.

2011

Ant Colony Optimization with Markov Random Walk for Community Detection in Graphs

Autores
Jin, D; Liu, DY; Yang, B; Baquero, C; He, DX;

Publicação
ADVANCES IN KNOWLEDGE DISCOVERY AND DATA MINING, PT II: 15TH PACIFIC-ASIA CONFERENCE, PAKDD 2011

Abstract
Network clustering problem (NCP) is the problem associated to the detection of network community structures. Building on Markov random walks we address this problem with a new ant colony optimization strategy, named as ACOMRW, which improves prior results on the NCP problem and does not require knowledge of the number of communities present on a given network. The framework of ant colony optimization is taken as the basic framework in the ACOMRW algorithm. At each iteration, a Markov random walk model is taken as heuristic rule; all of the ants' local solutions are aggregated to a global one through clustering ensemble, which then will be used to update a pheromone matrix. The strategy relies on the progressive strengthening of within-community links and the weakening of between-community links. Gradually this converges to a solution where the underlying community structure of the complex network will become clearly visible. The performance of algorithm ACOMRW was tested on a set of benchmark computer-generated networks, and as well on real-world network data sets. Experimental results confirm the validity and improvements met by this approach.

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