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Publications

2021

User-Driven Fine-Tuning for Beat Tracking

Authors
Pinto, AS; Bock, S; Cardoso, JS; Davies, MEP;

Publication
ELECTRONICS

Abstract
The extraction of the beat from musical audio signals represents a foundational task in the field of music information retrieval. While great advances in performance have been achieved due the use of deep neural networks, significant shortcomings still remain. In particular, performance is generally much lower on musical content that differs from that which is contained in existing annotated datasets used for neural network training, as well as in the presence of challenging musical conditions such as rubato. In this paper, we positioned our approach to beat tracking from a real-world perspective where an end-user targets very high accuracy on specific music pieces and for which the current state of the art is not effective. To this end, we explored the use of targeted fine-tuning of a state-of-the-art deep neural network based on a very limited temporal region of annotated beat locations. We demonstrated the success of our approach via improved performance across existing annotated datasets and a new annotation-correction approach for evaluation. Furthermore, we highlighted the ability of content-specific fine-tuning to learn both what is and what is not the beat in challenging musical conditions.

2021

Exploiting Motion Perception in Depth Estimation Through a Lightweight Convolutional Neural Network

Authors
Leite, PN; Pinto, AM;

Publication
IEEE ACCESS

Abstract
Understanding the surrounding 3D scene is of the utmost importance for many robotic applications. The rapid evolution of machine learning techniques has enabled impressive results when depth is extracted from a single image. High-latency networks are required to achieve these performances, rendering them unusable for time-constrained applications. This article introduces a lightweight Convolutional Neural Network (CNN) for depth estimation, NEON, designed for balancing both accuracy and inference times. Instead of solely focusing on visual features, the proposed methodology exploits the Motion-Parallax effect to combine the apparent motion of pixels with texture. This research demonstrates that motion perception provides crucial insight about the magnitude of movement for each pixel, which also encodes cues about depth since large displacements usually occur when objects are closer to the imaging sensor. NEON's performance is compared to relevant networks in terms of Root Mean Squared Error (RMSE), the percentage of correctly predicted pixels (delta(1)) and inference times, using the KITTI dataset. Experiments prove that NEON is significantly more efficient than the current top ranked network, estimating predictions 12 times faster; while achieving an average RMSE of 3.118 m and a delta(1) of 94.5%. Ablation studies demonstrate the relevance of tailoring the network to use motion perception principles in estimating depth from image sequences, considering that the effectiveness and quality of the estimated depth map is similar to more computational demanding state-of-the-art networks. Therefore, this research proposes a network that can be integrated in robotic applications, where computational resources and processing-times are important constraints, enabling tasks such as obstacle avoidance, object recognition and robotic grasping.

2021

Integrated lotsizing, scheduling and blending decisions in the spinning industry

Authors
Camargo, VCB; Almada Lobo, B; Toledo, FMB;

Publication
Pesquisa Operacional

Abstract
In this paper, the relevance of integrated planning concerning decisions of production and blending in a spinning industry is studied. The scenario regards a plant that produces several yarn packages over a planning horizon. Each yarn type is produced using a blend of several cotton bales that must contain attributes to ensure the quality of the produced yarns. Three approaches to managing production and blending are compared; the first deals with the solution to the production scheduling and blending problems in a single integrated model. The second approach hierarchically addresses these problems. The third procedure combines features from the integrated and hierarchical approaches. These approaches are applied to a real-world problem, and their respective performances are analyzed. The third approach proved to deal with lot sizing, scheduling and blending in the spinning industry more efficiently. Moreover, the results indicate the importance of coordinating production and blending decisions. © 2021 Brazilian Operations Research Society.

2021

Um observatório das Indústrias Criativas em Portugal: o Obcrei.pt

Authors
Pinto, Maria Manuela Gomes de Azevedo; Martins, Tiago Costa; Silva, Armando Malheiro da;

Publication

Abstract
The aim is to present the first phase of the conception and implementation of the Observatory of Creative Industries in Portugal (ObCrei.pt), a project supported by a R&D unity of the Faculty of Arts and Humanities of the University of Porto, CIC.Digital-Porto, that aims to provide access to the information analysis and indicators of this emerging sector at a national scale. Information analysis, systematization and availability parameters are specified, as well as studies from the creative industries point of view. The debate and projection of indicators is presented and focused on five elements of analysis: creative and cultural industries; dimensions (the recognition of agents and creative institutions); creative cycles; administrative scales; temporalities. It is followed by the presentation of the indicator's visualization model and the interactive dashboard, which highlights the connections between the five elements of analysis. As a conclusion, it is emphasized the development perspectives of this infocommunicational tool.

2021

A bilevel approach for the collaborative transportation planning problem

Authors
Santos, MJ; Curcio, E; Amorim, P; Carvalho, M; Marques, A;

Publication
INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS

Abstract
The integration of the outbound and the inbound logistics of a company leads to a large transportation network, allowing to detect backhauling opportunities to increase the efficiency of the transportation. In collaborative networks, backhauling is used to find profitable services in the return trip to the depot and to reduce empty running of vehicles. This work investigates the vertical collaboration between a shipper and a carrier for the planning of integrated inbound and outbound transportation. Based on the hierarchical nature of the relation between the shipper and the carrier and their different goals, the problem is formulated as a bilevel Vehicle Routing Problem with Selective Backhauls (VRPSB). At the upper level, the shipper decides the minimum cost delivery routes and the set of incentives offered to the carrier to perform integrated routes. At the lower level, the carrier decides which incentives are accepted and on which routes the backhaul customers are visited. We devise a mathematical programming formulation for the bilevel VRPSB, where the routing and the pricing problems are optimized simultaneously, and propose an equivalent reformulation to reduce the problem to a single-level VRPSB. The impact of collaboration is evaluated against non-collaborative approaches and two different side payment schemes. The results suggest that our bilevel approach leads to solutions with higher synergy values than the approaches with side payments.

2021

An Enhanced Contingency-Based Model for Joint Energy and Reserve Markets Operation by Considering Wind and Energy Storage Systems

Authors
Habibi, M; Vahidinasab, V; Pirayesh, A; Shafie Khah, M; Catalao, JPS;

Publication
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS

Abstract
This article presents a contingency-based stochastic security-constrained unit commitment to address the integration of wind power producers to the joint energy and reserve markets. The model considers ancillary services as a solution to cope with the uncertainties of the problem. In this regard, a comprehensive model is considered that maintains the profit of supplementary services. The contingency ranking is a popular method for reducing the computation burden of the unit commitment problem, but performing the contingency analysis changes the high-impact events in previous ranking methods. This article employs an intelligent contingency ranking technique to address the above issue and to find the actual top-ranked outages based on the final solution. The proposed algorithm simultaneously clears the energy and reserve based on the mechanism of the day-ahead market. The main idea of this article is to develop a framework for considering the most effective outages in the presence of the uncertainty of wind power without a heavy computation burden. Also, energy storage systems are considered to evaluate the impact of the scheduling of storage under uncertainties. Also, an accelerated Benders decomposition technique is applied to solve the problem. Numerical results on a six-bus and the IEEE 118-bus test systems show the effectiveness of the proposed approach. Furthermore, it shows that utilizing both wind farms and storage devices will reduce the total operational cost of the system, while the intelligent contingency ranking analysis and enough reserves ensure the security of power supply.

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