Manuel J. Fonseca

Manuel J. Fonseca
University of Lisbon | UL · Department of Informatics

PhD

About

140
Publications
35,339
Reads
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2,539
Citations
Additional affiliations
January 2014 - present
University of Lisbon
Position
  • Professor (Associate)
October 1993 - December 2013
Technical University of Lisbon
Position
  • Professor (Assistant)

Publications

Publications (140)
Article
Full-text available
Introduction Video games have become increasingly popular worldwide, attracting billions of gamers across diverse demographics. While studies have highlighted their potential benefits, concerns about problematic gaming behaviors have also emerged. Conditions such as Internet Gaming Disorder (IGD) have been recognized by major health organizations,...
Article
The existence of large amounts of data increases the probability of occurring data quality problems. A data cleaning process that corrects these problems is usually an iterative process because it may need to be re-executed and refined to produce high quality data. Moreover, due to the specificity of some data quality problems and the limitation of...
Article
Full-text available
Recognizing emotions from physiological signals has proven to be important in various scenarios. To assist in developing emotion recognizers, software frameworks and toolboxes have emerged, offering ready-to-use components. However,these have limitations regarding the type of physiological signals supported, the recognition steps covered, or the ac...
Article
The success of supervised models for emotion recognition on images heavily depends on the availability of images properly annotated. Although millions of images are presently available, only a few are annotated with reliable emotional information. Current emotion recognition solutions either use large amounts of weakly-labeled web images, which oft...
Article
Full-text available
One of the main challenges in CBIR systems is to choose discriminative and compact features, among dozens, to represent the images under comparison. Over the years, a great effort has been made to combine multiple features, mainly using early, late, and hierarchical fusion techniques. Unveiling the perfect combination of features is highly domain-s...
Preprint
Full-text available
Reminiscence therapy is an inexpensive non-pharmacological therapy commonly used due to its therapeutic value for PwD, as it can be used to promote independence, positive moods and behavior, and improve their quality of life. Caregivers are one of the main pillars in the adoption of digital technologies for reminiscence therapy, as they are respons...
Article
Full-text available
Recognition of emotions from physiological signals, and in particular from electroencephalography (EEG), is a field within affective computing gaining increasing relevance. Although researchers have used these signals to recognize emotions, most of them only identify a limited set of emotional states (e.g., happiness, sadness, anger, etc.) and have...
Chapter
In the health sector, data analysis is typically performed by specialty using clinical data stored in a Clinical Data Registry (CDR), specific to that medical specialty. Therefore, if we want to analyze data from a new specialty, it is necessary to create a new CDR, which is usually done from scratch. Although the data stored in CDRs depends on the...
Chapter
Full-text available
Nowadays, the application of typical game elements in non-ludic environments has been extended. Gamification has become a very interesting resource to promote engagement and participation in a wide variety of areas including education. For this reason, researchers are increasingly interested in the study of gamification. There are many papers relat...
Article
Full-text available
Students’ participation and motivation are of great importance in their learning process. The decrease in attendance and difficulties in stimulating students’ activity makes it necessary to find new methodologies that can solve these problems. The use of game mechanics in non-ludic environments (Gamification) has begun to be of great interest in re...
Article
Full-text available
Background: The present study's main aim was to determine the predictors of movie rewatchability and recommendations. Methods: Using a sample of 318 participants, we first tested the structure of a gratification scale from watching a movie. Then, we examined the role of age, need for cognition, need for affect, extraversion, and emotional gratif...
Chapter
Nowadays, researchers are increasingly interested in the study of gamification. Gamification is the application of typical game elements in other areas. This technique can be used in different sectors like health, marketing, politics or education. In this paper we have focused on education. There are many papers related to the impact that this meth...
Chapter
Multimedia content is growing at an increasing pace. Making this content accessible to people with impairments is not only paramount but also a growing challenge in itself. Access services for people with visual or hearing impairments have been studied and refined over the last years, resulting in standards and laws to ensure that minimum amounts o...
Conference Paper
In this paper, we introduce a novel gaze-only interaction technique called EyeLinks, which was designed i) to support various types of discrete clickables (e.g. textual links, buttons, images, tabs, etc.); ii) to be easy to learn and use; iii) to mitigate the inaccuracy of affordable eye trackers. Our technique uses a two-step fixation approach: fi...
Article
Full-text available
Experimental studies of emotion usually use datasets of normative emotional pictures to elicit specifi�c emotional responses in human subjects. However, most of these datasets are not annotated with discriminating and reliable emotional tags, having only valence and arousal ratings for each image. Complementing this information with emotional tags...
Conference Paper
Full-text available
In this paper, we present a study with users to identify the dominant and the search colors users associate to a set of images. We supplement this information with gaze coordinates, collected with an affordable eye tracker, to register the regions at which people looked while identifying colors in the images. The analysis of the data revealed that...
Conference Paper
Full-text available
Elicitation of emotions is typically done through the presentation of emotionally salient material, like images or videos, thus requiring reliably annotated datasets. Although there are datasets with emotional information, these only de- scribe either emotional polarities or discrete emotions. The only available dataset with both types of informati...
Chapter
Full-text available
Recording patient clinical data in a comprehensive and easy way is very important for health care providers. However, and although there are information systems to facilitate the storage and access to patient data, many records are still in paper. Even when data is stored electronically, systems often are complex to use and do not provide means to...
Article
Emotions have an important role in daily life, not only in human interaction, but also in decision-making processes, and in the perception of the world around us. Due to the recent interest shown by the research community in establishing emotional interactions between humans and computers, the identification of the emotional state of the former bec...
Article
Full-text available
Nowadays, thanks to the popularization of music streaming services, we gained access to millions of songs to listen to. One of the methods employed by these services to support browsing and promote song discovery are playlists. Additionally, creating and sharing playlists over the Internet have become common practices. A playlist can be defined as...
Conference Paper
In this demo paper we describe PlaylistCreator, an assisted approach for supporting the creation of music playlists. Our solution allows creators to express song selection and browsing through a visual representation of their intents in a unified view, which relies on a set-based model for representing sources of songs. Creators can convey their pu...
Conference Paper
We describe a novel system for synthesising video choreography using sketched visual storyboards comprising human poses (stick men) and action labels. First, we describe an algorithm for searching archival dance footage using sketched pose. We match using an implicit representation of pose parsed from a mix of challenging low and high fidelity foot...
Article
The number of songs available on the Internet has grown steadily over the last decade, with the recent growth being due mainly to streaming services. As a consequence, it is extremely difficult for users to find the appropriate music that suit their needs, in particular, while using systems that do not have any previous information about them. This...
Article
Over the last years, multimedia collections have largely increased as new items are produced every day, such as pictures, audio/music or video. In Multimedia Information Retrieval, this exponential growth leads content-based approaches to gain advantage over other solutions, not only because they take advantage of the intrinsic information containe...
Conference Paper
Full-text available
Music recommendation systems based on Collaborative Filtering methods have been extensively developed over the last years. Typically, they work by analyzing the past user-song relationships, and provide informed guesses based on the overall information collected from other users. Although the music listening behavior is a repetitive and time-depend...
Conference Paper
Full-text available
Games are of great interest in education. Their motivational qualities make players more persistent and resilient. In particular, virtual environments have proven to be good learning engagers, as they generate opportunities to create, explore and communicate. Here we present an exploratory study on how student autonomy and creativity can be improve...
Conference Paper
Full-text available
Clip art databases can be composed by raster images or by vector drawings. There are technologies for searching and retrieving clip arts for both image formats but research has been done separately, focusing on either format, without taking benefits of both research fields as a whole. This paper describes a study where the benefits of combining inf...
Conference Paper
Every time we visit a new city there is a huge effort made in understanding its dynamic, i.e. what are the relevant locations within that city in each time period, for there are large amounts of data to sift through. Although several attempts have been made to combine information from various sources, the majority focus on geographic data, lacking...
Article
Sketch-based 3D shape retrieval has become an important research topic in content-based 3D object retrieval. To foster this research area, two Shape Retrieval Contest (SHREC) tracks on this topic have been organized by us in 2012 and 2013 based on a small-scale and large-scale benchmarks, respectively. Six and five (nine in total) distinct sketch-b...
Conference Paper
Although, color is one of the most visually distinguishable visual properties, color alone is not enough to describe the content of images. The spatial organization of the different color regions also play an important role. In this paper, we propose and evaluate a new descriptor that combines information about color and about its spatial arrangeme...
Conference Paper
In this paper we present an approach for interactive exploration of photo collections, which combines seamlessly multitouch gestures and sketches. Multitouch gestures are used to navigate through the photo collection, while sketches are used to filter the images presented to the user, according to their properties and metadata. The different gestur...
Conference Paper
The contribution of this paper is a sketch parser able to recognize the several components of a skeleton described using the drawing of a stick-man. We describe the sketch parser in detail, and briefly outline how it is applied to form the front-end of a sketch based retrieval system capable of searching for human poses in archival dance footage.
Conference Paper
In this paper we propose a solution for the identification of the dominant colors in pictures taking into account the way people perceive them. To that end we developed an algorithm based on a reduced palette of 12 colors and on a non-uniform segmentation of the HSV color space using fuzzy membership functions. Experimental results from an evaluati...
Conference Paper
Full-text available
Over the past years, music listening histories have become easily accessible due to the expansion of online lifelogging services. These histories represent the sequence of songs listen by users over time. Although this data contains intrinsic users' tastes and listening behaviors, it has been mainly used to personalize recommendations. Tools to hel...
Article
Full-text available
Blogs are widely used today to publish information on a regular basis. However, users have difficulty in exploring their content and in discovering relevant information. This is due, among other things, to blogs rigid structure, with very long pages, and to the lack of mechanisms for effective navigation and exploration. To overcome these problems,...
Conference Paper
Full-text available
Nowadays, people spend time using services to track their music listening history. Although these services provide statistics and small graphics/charts, they are mainly used to record and to allow direct access to the information, not providing any visualization and exploration functionality. In this paper we describe a new approach for browsing an...
Conference Paper
Nowadays almost all retrieval algorithms (for text, images, drawings, etc.) are mainly concerned in achieving good system-centered measures, such as precision and recall. How- ever, these systems are used by users, who try to achieve goals through the execution of tasks. To better satisfy the users' needs we must involve them in the development pro...
Conference Paper
Full-text available
The increasing number of three-dimensional objects available on digital format triggered a great interest in research in this domain. Finding efficient methods of analysis, comparison and retrieval of 3D models has become an important task. However, despite the existence of some benchmarks with collections of 3D models, annual contests with specifi...
Chapter
Full-text available
Most drawing (and image) retrieval systems typically use query-by-example mechanisms or textual queries. In this chapter, we use sketches to retrieve complex vector drawings, as a solution to supplement and overcome limitations of conventional query methods. We start by describing topological and geometric information extracted from drawings and me...
Article
Full-text available
A decade ago, Nakazato proposed 3D MARS, an immer-sive virtual reality environment for content-based image retrieval. Even so, the idea of taking advantage of post-WIMP interfaces for multimedia retrieval was no further explored for content-based retrieval. Considering the latest low-cost, off-the-shelf hardware for visualization and interaction, w...
Conference Paper
Full-text available
In this paper we present MuVis, an interactive visualization and exploration tool for large music collections, based on music content and metadata. We combined a user-centered design with three main components: information visualization techniques (based on semantic ordered treemaps), music information retrieval mechanisms (for semantic and content...
Conference Paper
Full-text available
Navigation and browsing on a computer system are usually done using the file system hierarchy. However, this is not the most adequate method to search or locate a given file at a later time, unless we know exactly where it is. In this paper, we present a new approach for interactive file search·ing, which takes advantage of the (implicit) metadata...
Article
Research in content-based 3D retrieval has already started, and several approaches have been proposed which use in different manner a similarity assessment to match the shape of the query against the shape of the objects in the database. However, the success of these solutions are far from the success obtained by their textual counterparts. A major...
Article
Full-text available
Currently, the design of aesthetic products is a process that requires a set of activities where digital models and physical mockups play a key role. Typically, these are modified (and built) several times before reaching the desired design, increasing the development time and, consequently, the final product cost. In this paper, we present an inno...
Article
Currently, there are large collections of drawings from which users can select the desired ones to insert in their documents. However, to locate a particular drawing among thousands is not easy. In our prior work we proposed an approach to index and retrieve vector drawings by content, using topological and geometric information automatically extra...
Conference Paper
Full-text available
With the vast amount of documents that users tend to accumulate in their hard drives, it is natural that they often forget where a certain file is stored or even its name. However, sometimes they still recall a mental image of the document layout. To explore this, we propose a new approach to document retrieval, based on sketches, that capitalizes...
Article
Due to the proliferation of drafting packages, there are a lot of vector drawings available for people to integrate into documents. Moreover, creative designers and drafts-people often reuse data from previous projects and libraries of ready-to-use components. Usually, retrieving these drawings is a slow, complex and error-prone endeavor. While tex...
Conference Paper
Full-text available
This paper addresses the prediction of user moves in a case study where user interaction with a software game is predicted on the basis of λ-parameters acquired from users with special needs playing the game. A model was built to reproduce actions performed by such users to overcome the difficult set-up of tests given user reduced availability, mob...
Conference Paper
Full-text available
Over the last years, amateur artists have been using the new Internet technologies to easily produce, share and distribute their comics. However, web applications for this kind of creation are still restricting users by adopting simple and very limiting interaction methods. Therefore, these systems do not allow the creation of visually rich comics...
Conference Paper
Full-text available
The interactive creation of comics on the World Wide Web has become increasingly relevant over the last few years as a way for amateur creators to produce, share and distribute their comics. However, web applications that allow this kind of creation still restrict users interaction by not considering the repetition of previous elements across a com...
Article
Currently, there are large collections of clip-art vector drawings from which users can select the desired figures to insert in their documents. However, to locate a particular drawing among thousands is not easy. Although there are some solutions for drawing retrieval, almost all of them are designed to retrieve simple and not complex drawings as...
Conference Paper
Full-text available
With the growing popularity of digital cameras, the organization, browsing, management and grouping of photos become a problem of every photograph (professional or amateur), because their collections easily achieve the order of thousands. Here, we present a system to automate these processes, which relies on photo information, such as, semantic fea...
Conference Paper
Full-text available
In this paper we describe a system to create LEGO models using sketches. Although there are a few applications to create LEGO models, they are difficult to use, mainly due to the searching and manipulation mechanisms that they (do not) offer. Here, we propose a sketch based approach, where users can easily insert parts, by specifying their dimensio...
Conference Paper
Full-text available
Currently, there are large collections of drawings from which users can select the desired ones to insert in their documents. However, to locate a particular drawing among thousands is not easy. In our prior work we proposed an approach to index and retrieve vector drawings by content, using topological and geometric information automatically extra...
Chapter
Full-text available
Moulds are complex devices and their quotation is one of the most risky tasks in mould industry. In this paper a digital work environment based on a computer assisted mould quotation tool is proposed in which all the relevant information is quickly available to assist a robust and rapid quotation. The tool involves a new way to directly access past...
Chapter
Full-text available
This paper presents an application based on digital enterprise technologies to support both the business globalization and service providing in small and medium sized companies highly focused in production competences. The requirements and functionalise are discussed and the application to support the work environment, communication and remote acce...
Conference Paper
Full-text available
Abtract The concurrent engineering and the co-operative engineering in a geographically distributed network, supported by information technologies, is a competitive advantage for the tool and die Portuguese companies. In this paper a new user-friendly visual communication tool to support virtual meetings in an engineering context is presented. The...
Conference Paper
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