Cookies
O website necessita de alguns cookies e outros recursos semelhantes para funcionar. Caso o permita, o INESC TEC irá utilizar cookies para recolher dados sobre as suas visitas, contribuindo, assim, para estatísticas agregadas que permitem melhorar o nosso serviço. Ver mais
Aceitar Rejeitar
  • Menu
Publicações

2017

Weightless neural networks for open set recognition

Autores
Cardoso, DO; Gama, J; França, FMG;

Publicação
MACHINE LEARNING

Abstract
Open set recognition is a classification-like task. It is accomplished not only by the identification of observations which belong to targeted classes (i.e., the classes among those represented in the training sample which should be later recognized) but also by the rejection of inputs from other classes in the problem domain. The need for proper handling of elements of classes beyond those of interest is frequently ignored, even in works found in the literature. This leads to the improper development of learning systems, which may obtain misleading results when evaluated in their test beds, consequently failing to keep the performance level while facing some real challenge. The adaptation of a classifier for open set recognition is not always possible: the probabilistic premises most of them are built upon are not valid in a open-set setting. Still, this paper details how this was realized for WiSARD a weightless artificial neural network model. Such achievement was based on an elaborate distance-like computation this model provides and the definition of rejection thresholds during training. The proposed methodology was tested through a collection of experiments, with distinct backgrounds and goals. The results obtained confirm the usefulness of this tool for open set recognition.

2017

Simultaneous Measurement of Temperature and Refractive Index Based on Microfiber Knot Resonator Integrated in an Abrupt Taper Mach-Zehnder Interferometer

Autores
Gomes, AD; Frazao, O;

Publicação
THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
A microfiber knot resonator integrated in an abrupt taper-based Mach-Zehnder interferometer was used for simultaneous measurement of temperature and refractive index. This compact structure was fabricated using only CO2 laser processing. The transmission spectrum is the combination of the microfiber knot resonator and the Mach-Zehnder interferometer responses. The two different components of the transmission spectrum (the microfiber knot resonator and the MachZehnder interferometer components) present different sensitivities when subjected to physical or chemical parameters. A characterization in temperature, refractive index, and sodium chloride (NaCl) concentration was performed. A simple matrix method was used for simultaneous measurement of temperature and refractive index.

2017

Preface

Autores
Rocha, Á; Correia, AM; Adeli, H; Reis, LP; Costanzo, S;

Publicação
Advances in Intelligent Systems and Computing

Abstract

2017

Dual-ramp for the capacitated single allocation ?-hub location problem

Autores
Matos, T; Gamboa, D;

Publicação
Proceedings of International Conference on Computers and Industrial Engineering, CIE

Abstract
In this paper, we address the Capacitated Single Allocation ?-Hub Location Problem (CSA?HLP) in which the capacities of the hubs limit the flows in the network and every non-hub node must be allocated to only one hub. The objective is to choose a fixed number of ? nodes to be established as hubs that minimizes the costs of allocating all the non-hub nodes to the chosen hubs. We propose a simple Relaxation Adaptive Memory Programming (RAMP) approach that uses Lagrangean Relaxation with subgradient optimization to explore the dual side, a projection method to project dual solutions into the primal solutions space and an improvement method to guide the search in the primal side. The computational results obtained on a classical set of benchmark problems showed that our algorithm achieved the best results in the literature, demonstrating the advantages of exploring primal-dual relationships.

2017

Mineração de Textos para Apoiar a Predição de Severidade de Relatórios de Incidentes: um Estudo de Viabilidade

Autores
Barbosa, JR; Matsuno, IP; Guimarães, ER; Rezende, SO; Vincenzi, AMR; Delamaro, ME;

Publicação
SBQS

Abstract

2017

Glucose diffusion in colorectal mucosa-a comparative study between normal and cancer tissues

Autores
Carvalho, S; Gueiral, N; Nogueira, E; Henrique, R; Oliveira, L; Tuchin, VV;

Publicação
JOURNAL OF BIOMEDICAL OPTICS

Abstract
Colorectal carcinoma is a major health concern worldwide and its high incidence and mortality require accurate screening methods. Following endoscopic examination, polyps must be removed for histopathological characterization. Aiming to contribute to the improvement of current endoscopy methods of colorectal carcinoma screening or even for future development of laser treatment procedures, we studied the diffusion properties of glucose and water in colorectal healthy and pathological mucosa. These parameters characterize the tissue dehydration and the refractive index matching mechanisms of optical clearing (OC). We used ex vivo tissues to measure the collimated transmittance spectra and thickness during treatments with OC solutions containing glucose in different concentrations. These time dependencies allowed for estimating the diffusion time and diffusion coefficient values of glucose and water in both types of tissues. The measured diffusion times for glucose in healthy and pathological mucosa samples were 299.2 +/- 4.7 s and 320.6 +/- 10.6 s for 40% and 35% glucose concentrations, respectively. Such a difference indicates a slower glucose diffusion in cancer tissues, which originate from their ability to trap far more glucose than healthy tissues. We have also found a higher free water content in cancerous tissue that is estimated as 64.4% instead of 59.4% for healthy mucosa. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

  • 2253
  • 4492