VLDB 2026 Research / reviewers in the wild / expert
Iulia Lefter
dblp:12/8420
· DBLP profile ↗
14ranked-venue papers
8as first author
5since 2021 · last 2025
0000-0002-7243-2027ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Human-computer interaction and ubiquitous computing · 8 · 4 first-author · 4 since 2021Artificial intelligence and machine learning · 4 · 2 first-author · 2 since 2021Graphics, computer vision, multimedia, augmented reality and games · 4 · 1 first-author · 2 since 2021Databases, data management, data science and information retrieval · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Knowing Me, Knowing AU: How Should We Design Agent-Mediated Mimicry?
Agnes Johanna Axelsson, Weilun Chen, Deborah van Sinttruije, Iulia Lefter, Laurens Rook, Catholijn M. Jonker, Catharine Oertel |
Conference on Designing Interactive Systems | 4 |
| 2022 | The need for a female perspective in designing agent-based negotiation supportabstractThis study investigates whether an agent-based Negotiation Training System (NTS) can teach women Strategic Empathy - a recently introduced negotiation strategy based on perspective taking - and whether this can improve their negotiation performance. Developed and tested through an interaction-based real-time experiment was a NTS that integrated instructions on how to utilize Strategic Empathy. Women in the experimental group showed significantly higher levels of perspective-taking compared to the control group, and their understanding and use of Strategic Empathy increased over time. Also, a significant positive effect was found of Strategic Empathy on women's self-efficacy. No significant positive effect was found of Strategic Empathy on persistence. The high cognitive load of the experiment and a lack of intrinsic motivation may have caused this finding. Overall, this work demonstrates the applicability of using NTS to teach Strategic Empathy, and its effectiveness for enhancing women's self-efficacy in salary negotiations. Katja Bouman, Iulia Lefter, Laurens Rook, Catharine Oertel, Catholijn M. Jonker, Frances M. T. Brazier |
IVA | 2 |
| 2022 | Incorporating the Theory of Attention in Applied Game Design
Isabelle Kniestedt, Stephan G. Lukosch, Milan van der Kuil, Iulia Lefter, Frances M. T. Brazier |
ICEC | 4 |
| 2021 | The INTERSPEECH 2021 Computational Paralinguistics Challenge: COVID-19 Cough, COVID-19 Speech, Escalation & PrimatesabstractThe INTERSPEECH 2021 Computational Paralinguistics Challenge addresses four different problems for the first time in a research competition under well-defined conditions: In the COVID-19 Cough and COVID-19 Speech Sub-Challenges, a binary classification on COVID-19 infection has to be made based on coughing sounds and speech; in the Escalation SubChallenge, a three-way assessment of the level of escalation in a dialogue is featured; and in the Primates Sub-Challenge, four species vs background need to be classified. We describe the Sub-Challenges, baseline feature extraction, and classifiers based on the 'usual' COMPARE and BoAW features as well as deep unsupervised representation learning using the AuDeep toolkit, and deep feature extraction from pre-trained CNNs using the Deep Spectrum toolkit; in addition, we add deep end-to-end sequential modelling, and partially linguistic analysis. Björn W. Schuller, Anton Batliner, Christian Bergler, Cecilia Mascolo, Jing Han 0010, Iulia Lefter, Heysem Kaya, Shahin Amiriparian, Alice Baird, Lukas Stappen, Sandra Ottl, Maurice Gerczuk, Panagiotis Tzirakis, Chloë Siegele-Brown, Jagmohan Chauhan, Andreas Grammenos, Apinan Hasthanasombat, Dimitris Spathis, Tong Xia, Pietro Cicuta, Léon J. M. Rothkrantz, Joeri A. Zwerts, Jelle Treep, Casper S. Kaandorp |
Interspeech | 6 |
| 2021 | Dive Deeper: Empirical Analysis of Game Mechanics and Perceived Value in Serious GamesabstractValidation of serious games tends to focus on evaluating their design as a whole. While this helps to assess whether a particular combination of game mechanics is successful, it provides little insight into how individual mechanics contribute or detract from a serious game's purpose or a player's game experience. This study analyses the effect of game mechanics commonly used in casual games for engagement, measured as a combination of player behaviour and reported game experience. Secondly, it examines the role of a serious game's purpose on those same measures. An experimental study was conducted with 204 participants playing several versions of a serious game to explore these points. The results show that adding additional game mechanics to a core gameplay loop did not lead to participants playing more or longer, nor did it improve their game experience. Players who were aware of the game's purpose, however, perceived the game as more beneficial, scored their game experience higher, and progressed further. The results show that game mechanics on their own do not necessarily improve engagement, while the effect of perceived value deserves further study. Isabelle Kniestedt, Marcello A. Gómez Maureira, Iulia Lefter, Stephan G. Lukosch, Frances M. T. Brazier |
Proc. ACM Hum. Comput. Interact. | 3 |
| 2020 | Summary of MuSe 2020: Multimodal Sentiment Analysis, Emotion-target Engagement and Trustworthiness Detection in Real-life MediaabstractThe first Multimodal Sentiment Analysis in Real-life Media (MuSe) 2020 was a Challenge-based Workshop held in conjunction with ACM Multimedia'20. It addresses three distinct 'in-the-wild` Sub-challenges: sentiment/ emotion recognition (MuSe-Wild), emotion-target engagement (MuSe-Target) and trustworthiness detection (MuSe-Trust). A large multimedia dataset MuSe-CaR was used, which was specifically designed with the intention of improving machine understanding approaches of how sentiment (e.g. emotion) is linked to a topic in emotional, user-generated reviews. In this summary, we describe the motivation, first of its kind 'in-the-wild` database, challenge conditions, participation, as well as giving an overview of utilised state-of-the-art techniques. Lukas Stappen, Björn W. Schuller, Iulia Lefter, Erik Cambria, Ioannis Kompatsiaris |
ACM Multimedia | 3 |
| 2018 | The Multimodal Dataset of Negative Affect and Aggression: A Validation StudyabstractWithin the affective computing and social signal processing communities, increasing efforts are being made in order to collect data with genuine (emotional) content. When it comes to negative emotions and even aggression, ethical and privacy related issues prevent the usage of many emotion elicitation methods, and most often actors are employed to act out different scenarios. Moreover, for most databases, emotional arousal is not explicitly checked, and the footage is annotated by external raters based on observable behavior. In the attempt to gather data a step closer to real-life, previous work proposed an elicitation method for collecting the database of negative affect and aggression that involved unscripted role-plays between aggression regulation training actors (actors) and naive participants (students), where only short role descriptions and goals are given to the participants. In this paper we present a validation study for the database of negative affect and aggression by investigating whether the actors' behavior (e.g. becoming more aggressive) had a real impact on the students' emotional arousal. We found significant changes in the students' heart rate variability (HRV) parameters corresponding to changes in aggression level and emotional states of the actors, and therefore conclude that this method can be considered as a good candidate for emotion elicitation. Iulia Lefter, Siska Fitrianie |
ICMI | 1 |
| 2017 | Aggression recognition using overlapping speechabstractAutomatic recognition of negative affect and aggression is key in many safety critical domains such as surveillance and health care. In this paper we explore the potential of overlapping speech for predicting aggression levels. As a first step we consider 3 categories of overlapping speech based on literature. Having an annotation of these overlap categories, we examine whether overlapping speech is a good feature for predicting aggression by using it in classification together with a set of acoustic features typically used for this purpose. Next, we explore if this fine categorization of overlap is necessary in predicting aggression levels or a more coarse representation is sufficient. Finally, we check the additive values of automatically predicted overlapping speech for aggression recognition. The experiments are performed on a dataset of dyadic interactions between professional aggression training actors (actors) and naive participants (students) interacting freely based on short role descriptions. Our findings show that overlapping speech is a key feature for predicting aggression levels, that discriminating only severe cases of overlap is a sufficient feature and that automatically predicted overlap is improving aggression recognition as well. Iulia Lefter, Catholijn M. Jonker |
ACII | 1 |
| 2017 | NAA: A multimodal database of negative affect and aggressionabstractWe present the collection and annotation of a multi-modal database with negative human-human interactions. The work is part of supporting behavior recognition in the context of a virtual reality aggression prevention training system. The data consist of dyadic interactions between professional aggression training actors (actors) and naive participants (students). In addition to audio and video, we have recorded motion capture data with kinect, head tracking, and physiological data: heart rate (ECG), galvanic skin response (GSR) and electromyography (EMG) of biceps, triceps and trapezius muscles. Aggression levels, fear, valence, arousal and dominance have been rated separately for actors and students. We observe higher inter-rater agreement for rating the actors than for rating the students, consistently for each annotated dimension, and a higher inter-rater agreement for speaking behavior than for listening behavior. The data can be used among others for research on affect recognition, multimodal fusion and the relation between different bodily manifestation. Iulia Lefter, Catholijn M. Jonker, Stephanie Klein Tuente, Wim Veling, Stefan Bogaerts |
ACII | 1 |
| 2016 | Recognizing Stress Using Semantics and Modulation of Speech and GesturesabstractThis paper investigates how speech and gestures convey stress, and how they can be used for automatic stress recognition. As a first step, we look into how humans use speech and gestures to convey stress. In particular, for both speech and gestures, we distinguish between stress conveyed by the intended semantic message (e.g. spoken words for speech, symbolic meaning for gestures), and stress conveyed by the modulation of either speech and gestures (e.g. intonation for speech, speed and rhythm for gestures). As a second step, we use this decomposition of stress as an approach for automatic stress prediction. The considered components provide an intermediate representation with intrinsic meaning, which helps bridging the semantic gap between the low level sensor representation and the high level context sensitive interpretation of behavior. Our experiments are run on an audiovisual dataset with service-desk interactions. The final goal is having a surveillance system that would notify when the stress level is high and extra assistance is needed. We find that speech modulation is the best performing intermediate level variable for automatic stress prediction. Using gestures increases the performance and is mostly beneficial when speech is lacking. The two-stage approach with intermediate variables performs better than baseline feature level or decision level fusion. Iulia Lefter, Gertjan J. Burghouts, Léon J. M. Rothkrantz |
IEEE Trans. Affect. Comput. | 1 |
| 2015 | Cross-corpus analysis for acoustic recognition of negative interactionsabstractRecent years have witnessed a growing interest in recognizing emotions and events based on speech. One of the applications of such systems is automatically detecting when a situations gets out of hand and human intervention is needed. Most studies have focused on increasing recognition accuracies using parts of the same dataset for training and testing. However, this says little about how such a trained system is expected to perform `in the wild'. In this paper we present a cross-corpus study using the audio part of three multimodal datasets containing negative human-human interactions. We present intra- and cross-corpus accuracies whilst manipulating the acoustic features, normalization schemes, and oversampling of the least represented class to alleviate the negative effects of data unbalance. We observe a decrease in performance when disjunct corpora are used for training and testing. Merging two datasets for training results in a slightly lower performance than the best one obtained by using only one corpus for training. A hand crafted low dimensional feature set shows competitive behavior when compared to a brute force high dimensional features vector. Corpus normalization and artificially creating samples of the sparsest class have a positive effect. Iulia Lefter, Harold T. Nefs, Catholijn M. Jonker, Léon J. M. Rothkrantz |
ACII | 1 |
| 2013 | A comparative study on automatic audio-visual fusion for aggression detection using meta-information
Iulia Lefter, Léon J. M. Rothkrantz, Gertjan J. Burghouts |
Pattern Recognit. Lett. | 1 |
| 2012 | Automatic Audio-Visual Fusion for Aggression Detection Using Meta-informationabstractWe propose a new method for audio-visual sensor fusion and apply it to automatic aggression detection. While a variety of definitions of aggression exist, in this paper we see it as any kind of behavior that has a disturbing effect on others. We have collected multi- and unimodal assessments by humans, who have given aggression scores on a 3 point scale. There are no trivial fusion algorithms to predict the multimodal labels from the unimodal labels. We propose an intermediate step to discover the structure in the fusion process. We call these meta-features and we find a set of five which have an impact on the fusion process. We use simple state of the art low level audio and video features to predict the level of aggression in audio and video, and we also predict the three most feasible meta-features. We show the significant positive impact of adding the meta-features on predicting the multimodal label as compared to standard fusion techniques like feature and decision level fusion. Iulia Lefter, Gertjan J. Burghouts, Léon J. M. Rothkrantz |
AVSS | 1 |
| 2012 | Learning the fusion of audio and video aggression assessment by meta-information from human annotations
Iulia Lefter, Gertjan J. Burghouts, Léon J. M. Rothkrantz |
FUSION | 1 |