2024
Autores
Nogueira, C; Fernandes, L; Fernandes, JND; Cardoso, JS;
Publicação
SENSORS
Abstract
Deep learning has rapidly increased in popularity, leading to the development of perception solutions for autonomous driving. The latter field leverages techniques developed for computer vision in other domains for accomplishing perception tasks such as object detection. However, the black-box nature of deep neural models and the complexity of the autonomous driving context motivates the study of explainability in these models that perform perception tasks. Moreover, this work explores explainable AI techniques for the object detection task in the context of autonomous driving. An extensive and detailed comparison is carried out between gradient-based and perturbation-based methods (e.g., D-RISE). Moreover, several experimental setups are used with different backbone architectures and different datasets to observe the influence of these aspects in the explanations. All the techniques explored consist of saliency methods, making their interpretation and evaluation primarily visual. Nevertheless, numerical assessment methods are also used. Overall, D-RISE and guided backpropagation obtain more localized explanations. However, D-RISE highlights more meaningful regions, providing more human-understandable explanations. To the best of our knowledge, this is the first approach to obtaining explanations focusing on the regression of the bounding box coordinates.
2024
Autores
Falckenthal, B; Figueiredo, C; Palma-Moreira, A; Au-Yong-Oliveira, M;
Publicação
ADMINISTRATIVE SCIENCES
Abstract
The main objective of this study is to investigate a solution for the current lack of skilled workers in Europe and to optimize the utilization of expertise. For this qualitative study, 36 semi-structured interviews were conducted (with a purposive sample of financially independent (soon-to-be) retirees and employers). The thematic analysis revealed (1) on both the employer's and recruiter's side, there are many stereotypes and prejudices, as well as a lack of creativity about how to integrate these highly motivated specialists into the organization's workforce; (2) Employees, retirees and employers where asked: what could be the motivation to employ retirees, what could be the benefits, what could be the drawbacks. The results also indicate that searching for intellectual challenges and solving them with a team of co-workers is one of the main attractions for senior experts. We identified six main patterns for unretirement choices: learning and intellectual challenges, applying expertise, public perception of retirees, belonging and social connections, compensating for loss of status, and feeling appreciated. Appreciating, valuing, and channeling this drive to solve present-day problems independent of a person's chronological age should be self-evident for organizations and societies.
2024
Autores
Dionísio, RP; Rosa, AR; Jesus, CSDS;
Publicação
Lecture Notes in Networks and Systems
Abstract
Falls are one of the causes of severe hilliness among elders, and the COVID-19 pandemic increased the number of unattended cases because of the social distancing measures. This study aims to create a dataset that collects the data from a 3-axis acceleration sensor fixed on a hinged board apparatus that mimics a human fall event. The datalogging system uses off-the-shelf devices to measure, collect and store the data. The resulting dataset includes data from different angle positions and heights, corresponding to joints of the lower limbs of the human body (ankle, knee, and hip). We use the dataset with a threshold-based fall detection algorithm. The result from the Receiver Operating Characteristic curve shows a good behavior with a mean Area Under the Curve of 0.77 and allow to compute a best threshold value with False Positive Rate of 14.8% and True Positive rate of 89.1%. The optimal threshold value may vary depending on the specific population, activity patterns, and environmental conditions, which may require further customization and validation in real-world settings. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.
2024
Autores
Campos, R; Jorge, A; Jatowt, A; Bhatia, S; Litvak, M;
Publicação
ADVANCES IN INFORMATION RETRIEVAL, ECIR 2024, PT V
Abstract
The Text2Story Workshop series, dedicated to Narrative Extraction from Texts, has been running successfully since 2018. Over the past six years, significant progress, largely propelled by Transformers and Large Language Models, has advanced our understanding of natural language text. Nevertheless, the representation, analysis, generation, and comprehensive identification of the different elements that compose a narrative structure remains a challenging objective. In its seventh edition, the workshop strives to consolidate a common platform and a multidisciplinary community for discussing and addressing various issues related to narrative extraction tasks. In particular, we aim to bring to the forefront the challenges involved in understanding narrative structures and integrating their representation into established frameworks, as well as in modern architectures (e.g., transformers) and AI-powered language models (e.g., chatGPT) which are now common and form the backbone of almost every IR and NLP application. Text2Story encompasses sessions covering full research papers, work-in-progress, demos, resources, position and dissemination papers, along with keynote talks. Moreover, there is dedicated space for informal discussions on methods, challenges, and the future of research in this dynamic field.
2024
Autores
Fernandes, L; Fernandes, JND; Calado, M; Pinto, JR; Cerqueira, R; Cardoso, JS;
Publicação
IEEE ACCESS
Abstract
Deep Learning models are automating many daily routine tasks, indicating that in the future, even high-risk tasks will be automated, such as healthcare and automated driving areas. However, due to the complexity of such deep learning models, it is challenging to understand their reasoning. Furthermore, the black box nature of the designed deep learning models may undermine public confidence in critical areas. Current efforts on intrinsically interpretable models focus only on classification tasks, leaving a gap in models for object detection. Therefore, this paper proposes a deep learning model that is intrinsically explainable for the object detection task. The chosen design for such a model is a combination of the well-known Faster-RCNN model with the ProtoPNet model. For the Explainable AI experiments, the chosen performance metric was the similarity score from the ProtoPNet model. Our experiments show that this combination leads to a deep learning model that is able to explain its classifications, with similarity scores, using a visual bag of words, which are called prototypes, that are learned during the training process. Furthermore, the adoption of such an explainable method does not seem to hinder the performance of the proposed model, which achieved a mAP of 69% in the KITTI dataset and a mAP of 66% in the GRAZPEDWRI-DX dataset. Moreover, our explanations have shown a high reliability on the similarity score.
2024
Autores
Noorbakhsh, S; Teixeira, AAC;
Publicação
JOURNAL OF ENTERPRISING COMMUNITIES-PEOPLE AND PLACES IN THE GLOBAL ECONOMY
Abstract
PurposeThis study aims to estimate the impact of refugee inflows on host countries' entrepreneurial rates. The refugee crisis led to an increased scientific and public policy interest in the impact of refugee inflows on host countries. One important perspective of such an impact, which is still underexplored, is the impact of refugee inflows on host countries entrepreneurial rates. Given the high number of refugees that flow to some countries, it would be valuable to assess the extent to which such countries are likely to reap the benefits from increasing refugee inflows in terms of (native and non-native) entrepreneurial talent enhancement. Design/methodology/approachResorting to dynamic (two-step system generalized method of moments) panel data estimations, based on 186 countries over the period between 2000 and 2019, this study estimates the impact of refugee inflows on host countries' entrepreneurial rates, measured by the total early-stage entrepreneurial activity (TEA) rate and the self-employment rate. FindingsIn general, higher refugee inflows are associated with lower host countries' TEA rates. However, refugee inflows significantly foster self-employment rates of medium-high and high income host countries and host countries located in Africa. These results suggest that refugee inflows tend to enhance necessity related new ventures and/ or new ventures (from native and non-native population) operating in low value-added, low profit sectors. Originality/valueThis study constitutes a novel empirical contribution by providing a macroeconomic, quantitative assessment of the impact of refugee from distinct nationalities on a diverse set of host countries' entrepreneurship rates in the past two decades resorting to dynamic panel data models, which enable to address the heterogeneity of the countries and deal with the endogeneity of the variables of the model.
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