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Publications

Publications by LIAAD

2021

Electronic Shopping Experience for Luxury Brands: A Factorial Analysis

Authors
Martins, N; Teixeira, SF; Reis, JL; Torres, A;

Publication
Smart Innovation, Systems and Technologies

Abstract
This research provides an overview of the online consumer experience of luxury brands in Portugal. The purpose of this study was to identify the significant factors that represent customers’ perceptions of the online shopping experience for luxury products. Using a quantitative approach, the authors conducted an online survey. 327 usable responses were obtained. Descriptive and factorial statistical analyzes were used to provide the empirical findings. This study proposes and empirically tests a model of the factorial structure of the online shopping experience for luxury goods. We found an eight-factor dimension structure that proposes the main contributors to understand the factors that represent consumer perceptions about buying luxury products online. The findings suggest that the eight ranked significant factors that represent the customer’s perception of the online luxury shopping experience are in this order: e-buying experience, e-loyalty, e-risk, e-satisfaction, luxury value, luxury useless, luxury future buy, and e-buying influence. The work provides empirical evidence that the eight significant factors represent the customer’s perception of the luxury shopping experience online, that help to understand how luxury brands should be managed online in order to enhance customer e-buying experience, e-satisfaction, e-loyalty, and luxury value proposition. This study provides several contributions for online luxury brand managers and some directions for further research. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

2021

An exploratory study on the emergency remote education experience of higher education students and teachers during the COVID-19 pandemic

Authors
Oliveira, G; Teixeira, JG; Torres, A; Morais, C;

Publication
BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY

Abstract
The COVID-19 pandemic situation has pushed many higher education institutions into a fast-paced, and mostly unstructured, emergency remote education process. In such an unprecedented context, it is important to understand how technology is mediating the educational process and how teachers and students are experiencing the change brought by the pandemic. This research aims to understand how the learning was mediated by technology during the early stages of the pandemic and how students and teachers experienced this sudden change. Data were collected following a qualitative research design. Thirty in-depth and semi-structured interviews (20 students and 10 teachers) were obtained and analysed following a thematic analysis approach. Results provide evidence on the adoption of remote education technologies due to the pandemic with impacts on the education process, ICT platforms usage and personal adaptation. The emergency remote education context led to mixed outcomes regarding the education process. Simultaneously, ICT platforms usage was mostly a positive experience and personal adaptation was mostly a negative experience. These results bring new insights for higher education organizations on actions they could take, such as curating the learning experience with standard, institutional-wide platforms, appropriate training for students and teachers, and suitable remote evaluation practices.

2021

Automatic Identification of Bird Species from Audio

Authors
Carvalho, S; Gomes, EF;

Publication
INTELLIGENT INFORMATION AND DATABASE SYSTEMS, ACIIDS 2021

Abstract
Bird species identification is a relevant and time-consuming task for ornithologists and ecologists. With growing amounts of audio annotated data, automatic bird classification using machine learning techniques is an important trend in the scientific community. Analyzing bird behavior and population trends helps detect other organisms in the environment and is an important problem in ecology. Bird populations react quickly to environmental changes, which makes their real time counting and tracking challenging and very useful. A reliable methodology that automatically identifies bird species from audio would therefore be a valuable tool for the experts in different scientific and applicational domains. The goal of this work is to propose a methodology able to identify bird species by its chirp. In this paper we explore deep learning techniques that are being used in this domain, such as Convolutional Neural Networks and Recurrent Neural Networks to classify the data. In deep learning, audio problems are commonly approached by converting them into images using audio feature extraction techniques such as Mel Spectrograms and Mel Frequency Cepstral Coefficients. We propose and test multiple deep learning and feature extraction combinations in order to find the most suitable approach to this problem.

2021

Analysis and Evaluation of Language Models for Word Sense Disambiguation

Authors
Loureiro, D; Rezaee, K; Pilehvar, MT; Camacho Collados, J;

Publication
COMPUTATIONAL LINGUISTICS

Abstract
Transformer-based language models have taken many fields in NLP by storm. BERT and its derivatives dominate most of the existing evaluation benchmarks, including those for Word Sense Disambiguation (WSD), thanks to their ability in capturing context-sensitive semantic nuances. However, there is still little knowledge about their capabilities and potential limitations in encoding and recovering word senses. In this article, we provide an in-depth quantitative and qualitative analysis of the celebrated BERT model with respect to lexical ambiguity. One of the main conclusions of our analysis is that BERT can accurately capture high-level sense distinctions, even when a limited number of examples is available for each word sense. Our analysis also reveals that in some cases language models come close to solving coarse grained noun disambiguation under ideal conditions in terms of availability of training data and computing resources. However, this scenario rarely occurs in real-world settings and, hence, many practical challenges remain even in the coarse-grained setting. We also perform an in-depth comparison of the two main language model-based WSD strategies, namely, fine-tuning and feature extraction, finding that the latter approach is more robust with respect to sense bias and it can better exploit limited available training data. In fact, the simple feature extraction strategy of averaging contextualized embeddings proves robust even using only three training sentences per word sense, with minimal improvements obtained by increasing the size of this training data.

2021

Deep learning for drug response prediction in cancer

Authors
Baptista, D; Ferreira, PG; Rocha, M;

Publication
BRIEFINGS IN BIOINFORMATICS

Abstract
Predicting the sensitivity of tumors to specific anti-cancer treatments is a challenge of paramount importance for precision medicine. Machine learning(ML) algorithms can be trained on high-throughput screening data to develop models that are able to predict the response of cancer cell lines and patients to novel drugs or drug combinations. Deep learning (DL) refers to a distinct class of ML algorithms that have achieved top-level performance in a variety of fields, including drug discovery. These types of models have unique characteristics that may make them more suitable for the complex task of modeling drug response based on both biological and chemical data, but the application of DL to drug response prediction has been unexplored until very recently. The few studies that have been published have shown promising results, and the use of DL for drug response prediction is beginning to attract greater interest from researchers in the field. In this article, we critically review recently published studies that have employed DL methods to predict drug response in cancer cell lines.We also provide a brief description of DL and the main types of architectures that have been used in these studies. Additionally, we present a selection of publicly available drug screening data resources that can be used to develop drug response prediction models. Finally, we also address the limitations of these approaches and provide a discussion on possible paths for further improvement.

2021

Population-scale tissue transcriptomics maps long non-coding RNAs to complex disease

Authors
de Goede, OM; Nachun, DC; Ferraro, NM; Gloudemans, MJ; Rao, AS; Smail, C; Eulalio, TY; Aguet, F; Ng, B; Xu, J; Barbeira, AN; Castel, SE; Kim-Hellmuth, S; Park, Y; Scott, AJ; Strober, BJ; Brown, CD; Wen, X; Hall, IM; Battle, A; Lappalainen, T; Im, HK; Ardlie, KG; Mostafavi, S; Quertermous, T; Kirkegaard, K; Montgomery, SB; Anand, S; Gabriel, S; Getz, GA; Graubert, A; Hadley, K; Handsaker, RE; Huang, KH; Li, X; MacArthur, DG; Meier, SR; Nedzel, JL; Nguyen, DT; Segrè, AV; Todres, E; Balliu, B; Bonazzola, R; Brown, A; Conrad, DF; Cotter, DJ; Cox, N; Das, S; Dermitzakis, ET; Einson, J; Engelhardt, BE; Eskin, E; Flynn, ED; Fresard, L; Gamazon, ER; Garrido-Martín, D; Gay, NR; Guigó, R; Hamel, AR; He, Y; Hoffman, PJ; Hormozdiari, F; Hou, L; Jo, B; Kasela, S; Kashin, S; Kellis, M; Kwong, A; Li, X; Liang, Y; Mangul, S; Mohammadi, P; Muñoz-Aguirre, M; Nobel, AB; Oliva, M; Park, Y; Parsana, P; Reverter, F; Rouhana, JM; Sabatti, C; Saha, A; Stephens, M; Stranger, BE; Teran, NA; Viñuela, A; Wang, G; Wright, F; Wucher, V; Zou, Y; Ferreira, PG; Li, G; Melé, M; Yeger-Lotem, E; Bradbury, D; Krubit, T; McLean, JA; Qi, L; Robinson, K; Roche, NV; Smith, AM; Tabor, DE; Undale, A; Bridge, J; Brigham, LE; Foster, BA; Gillard, BM; Hasz, R; Hunter, M; Johns, C; Johnson, M; Karasik, E; Kopen, G; Leinweber, WF; McDonald, A; Moser, MT; Myer, K; Ramsey, KD; Roe, B; Shad, S; Thomas, JA; Walters, G; Washington, M; Wheeler, J; Jewell, SD; Rohrer, DC; Valley, DR; Davis, DA; Mash, DC; Barcus, ME; Branton, PA; Sobin, L; Barker, LK; Gardiner, HM; Mosavel, M; Siminoff, LA; Flicek, P; Haeussler, M; Juettemann, T; Kent, WJ; Lee, CM; Powell, CC; Rosenbloom, KR; Ruffier, M; Sheppard, D; Taylor, K; Trevanion, SJ; Zerbino, DR; Abell, NS; Akey, J; Chen, L; Demanelis, K; Doherty, JA; Feinberg, AP; Hansen, KD; Hickey, PF; Jasmine, F; Jiang, L; Kaul, R; Kibriya, MG; Li, JB; Li, Q; Lin, S; Linder, SE; Pierce, BL; Rizzardi, LF; Skol, AD; Smith, KS; Snyder, M; Stamatoyannopoulos, J; Tang, H; Wang, M; Carithers, LJ; Guan, P; Koester, SE; Little, AR; Moore, HM; Nierras, CR; Rao, AK; Vaught, JB; Volpi, S;

Publication
Cell

Abstract
Long non-coding RNA (lncRNA) genes have well-established and important impacts on molecular and cellular functions. However, among the thousands of lncRNA genes, it is still a major challenge to identify the subset with disease or trait relevance. To systematically characterize these lncRNA genes, we used Genotype Tissue Expression (GTEx) project v8 genetic and multi-tissue transcriptomic data to profile the expression, genetic regulation, cellular contexts, and trait associations of 14,100 lncRNA genes across 49 tissues for 101 distinct complex genetic traits. Using these approaches, we identified 1,432 lncRNA gene-trait associations, 800 of which were not explained by stronger effects of neighboring protein-coding genes. This included associations between lncRNA quantitative trait loci and inflammatory bowel disease, type 1 and type 2 diabetes, and coronary artery disease, as well as rare variant associations to body mass index.

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