2021
Authors
Martins, J; Marreiros, G; Ferreira, CA;
Publication
Ambient Intelligence - Software and Applications - 12th International Symposium on Ambient Intelligence, ISAmI 2021, Salamanca, Spain, 6-8 October, 2021.
Abstract
Businesses that are growing by supplying more services or reaching more customers, might need to create or relocate a facility location to expand their geographical coverage and improve their services. This decision is complex, and it is crucial to analyse their client locations, their journeys and be aware of the factors that may affect their geographical decision and the impact that they can have in the business strategy. Therefore, the decision-maker needs to ensure that the location is the most profitable site according to the business scope and future perspectives. In this paper, we propose a decision support system to help businesses on this complex decision that is capable of providing facility location suggestions based on their journeys analysis and the factors that the decision-makers consider more relevant to the company. The system helps the business managers to make better decisions by returning facility locations that have potential to maximise the company’s profit by reducing costs and maximise the number of covered customers by expanding their territorial coverage. To verify and validate the decision support system, a system evaluation was developed. Thus, a survey was responded by decision-makers in order to evaluate the efficiency, understandability, accuracy and effectiveness of the suggestions. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
2021
Authors
Pratesi M.; Campos P.;
Publication
Statistical Journal of the IAOS
Abstract
After 12 years of EMOS experience it is time to open the discussion on the future of EMOS. This papers briefly describes the experience from the perspective of the Universities, trying also to describe the needs and role of the NSIs, Banks and other possible actors to join the network, and unlock the future. EMOS should reload (or evolute) to stay current and attractive. Statistical 'thinking' evolved and a major change and challenge for EMOS is to pick up this trend in its cooperation with the universities.
2021
Authors
Goncalves, CAO; Camacho, R; Goncalves, CT; Vieira, AS; Diz, LB; Iglesias, EL;
Publication
APPLIED SCIENCES-BASEL
Abstract
The exponential growth of documents in the web makes it very hard for researchers to be aware of the relevant work being done within the scientific community. The task of efficiently retrieving information has therefore become an important research topic. The objective of this study is to test how the efficiency of the text classification changes if different weights are previously assigned to the sections that compose the documents. The proposal takes into account the place (section) where terms are located in the document, and each section has a weight that can be modified depending on the corpus. To carry out the study, an extended version of the OHSUMED corpus with full documents have been created. Through the use of WEKA, we compared the use of abstracts only with that of full texts, as well as the use of section weighing combinations to assess their significance in the scientific article classification process using the SMO (Sequential Minimal Optimization), the WEKA Support Vector Machine (SVM) algorithm implementation. The experimental results show that the proposed combinations of the preprocessing techniques and feature selection achieve promising results for the task of full text scientific document classification. We also have evidence to conclude that enriched datasets with text from certain sections achieve better results than using only titles and abstracts.
2021
Authors
Bhanu, M; Mendes Moreira, J; Chandra, J;
Publication
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
Abstract
Techniques for using multi-way traffic patterns for traffic prediction is gaining importance. One of the possible techniques for representing the multi-way traffic patterns is tensors. Tensor decomposition is used to generate low-rank approximations of the original tensor that is subsequently used for traffic volume prediction. However, the existing tensor-based approaches do not consider certain important mutual relationships among the locations like temporal traffic reciprocity that can improve the prediction accuracy. In this paper, we introduce TeDCaN, a "Tensor Decomposition method with Characteristic Network" constraints that generate low rank approximations of the original tensor considering the traffic reciprocity at different pair of locations. Investigations using large traffic datasets from 2 different cities reveal that the prediction accuracy of TeDCaN considerably outperforms several state-of-art baselines for cases when complete traffic data is available as well as situations when a certain fraction of the data is missing - a likely scenario in many real datasets. We discover that TeDCaN achieves around 20% reduction in the RMSE scores as compared to the baselines. TeDCaN is applicable in many operations on such a big traffic network where the existing models would either be inapplicable or hard to perform. As one of the major yields, TeDCaN generates a "reduced dimensional network embedding" that captures the similarity of the nodes considering the traffic volume as well as the reciprocity of traffic between the nodes.
2021
Authors
Garcia, KD; de Sa, CR; Poel, M; Carvalho, T; Mendes Moreira, J; Cardoso, JMP; de Carvalho, ACPLF; Kok, JN;
Publication
NEUROCOMPUTING
Abstract
Human Activity Recognition is focused on the use of sensing technology to classify human activities and to infer human behavior. While traditional machine learning approaches use hand-crafted features to train their models, recent advancements in neural networks allow for automatic feature extraction. Auto-encoders are a type of neural network that can learn complex representations of the data and are commonly used for anomaly detection. In this work we propose a novel multi-class algorithm which consists of an ensemble of auto-encoders where each auto-encoder is associated with a unique class. We compared the proposed approach with other state-of-the-art approaches in the context of human activity recognition. Experimental results show that ensembles of auto-encoders can be efficient, robust and competitive. Moreover, this modular classifier structure allows for more flexible models. For example, the extension of the number of classes, by the inclusion of new auto-encoders, without the necessity to retrain the whole model. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
2021
Authors
Miranda, P; Faria, JP; Correia, FF; Fares, A; Graça, R; Moreira, JM;
Publication
SAC '21: The 36th ACM/SIGAPP Symposium on Applied Computing, Virtual Event, Republic of Korea, March 22-26, 2021
Abstract
Forecasts of the effort or delivery date can play an important role in managing software projects, but the estimates provided by development teams are often inaccurate and time-consuming to produce. This is not surprising given the uncertainty that underlies this activity. This work studies the use of Monte Carlo simulations for generating forecasts based on project historical data. We have designed and run experiments comparing these forecasts against what happened in practice and to estimates provided by developers, when available. Comparisons were made based on the mean magnitude of relative error (MMRE). We did also analyze how the forecasting accuracy varies with the amount of work to be forecasted and the amount of historical data used. To minimize the requirements on input data, delivery date forecasts for a set of user stories were computed based on takt time of past stories (time elapsed between the completion of consecutive stories); effort forecasts were computed based on full-time equivalent (FTE) hours allocated to the implementation of past stories. The MMRE of delivery date forecasting was 32% in a set of 10 runs (for different projects) of Monte Carlo simulation based on takt time. The MMRE of effort forecasting was 20% in a set of 5 runs of Monte Carlo simulation based on FTE allocation, much smaller than the MMRE of 134% of developers' estimates. A better forecasting accuracy was obtained when the number of historical data points was 20 or higher. These results suggest that Monte Carlo simulations may be used in practice for delivery date and effort forecasting in agile projects, after a few initial sprints. © 2021 ACM.
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