Dorothea Kolossa


2022

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RubCSG at SemEval-2022 Task 5: Ensemble learning for identifying misogynous MEMEs
Wentao Yu | Benedikt Boenninghoff | Jonas Röhrig | Dorothea Kolossa
Proceedings of the 16th International Workshop on Semantic Evaluation (SemEval-2022)

This work presents an ensemble system based on various uni-modal and bi-modal model architectures developed for the SemEval 2022 Task 5: MAMI-Multimedia Automatic Misogyny Identification. The challenge organizers provide an English meme dataset to develop and train systems for identifying and classifying misogynous memes. More precisely, the competition is separated into two sub-tasks: sub-task A asks for a binary decision as to whether a meme expresses misogyny, while sub-task B is to classify misogynous memes into the potentially overlapping sub-categories of stereotype, shaming, objectification, and violence. For our submission, we implement a new model fusion network and employ an ensemble learning approach for better performance. With this structure, we achieve a 0.755 macro-average F1-score (11th) in sub-task A and a 0.709 weighted-average F1-score (10th) in sub-task B.

2020

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Variational Autoencoder with Embedded Student-t Mixture Model for Authorship Attribution
Benedikt Boenninghoff | Steffen Zeiler | Robert Nickel | Dorothea Kolossa
Proceedings of the 28th International Conference on Computational Linguistics

Traditional computational authorship attribution describes a classification task in a closed-set scenario. Given a finite set of candidate authors and corresponding labeled texts, the objective is to determine which of the authors has written another set of anonymous or disputed texts. In this work, we propose a probabilistic autoencoding framework to deal with this supervised classification task. Variational autoencoders (VAEs) have had tremendous success in learning latent representations. However, existing VAEs are currently still bound by limitations imposed by the assumed Gaussianity of the underlying probability distributions in the latent space. In this work, we are extending a VAE with an embedded Gaussian mixture model to a Student-t mixture model, which allows for an independent control of the “heaviness” of the respective tails of the implied probability densities. Experiments over an Amazon review dataset indicate superior performance of the proposed method.

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MyFixit: An Annotated Dataset, Annotation Tool, and Baseline Methods for Information Extraction from Repair Manuals
Nima Nabizadeh | Dorothea Kolossa | Martin Heckmann
Proceedings of the Twelfth Language Resources and Evaluation Conference

Text instructions are among the most widely used media for learning and teaching. Hence, to create assistance systems that are capable of supporting humans autonomously in new tasks, it would be immensely productive, if machines were enabled to extract task knowledge from such text instructions. In this paper, we, therefore, focus on information extraction (IE) from the instructional text in repair manuals. This brings with it the multiple challenges of information extraction from the situated and technical language in relatively long and often complex instructions. To tackle these challenges, we introduce a semi-structured dataset of repair manuals. The dataset is annotated in a large category of devices, with information that we consider most valuable for an automated repair assistant, including the required tools and the disassembled parts at each step of the repair progress. We then propose methods that can serve as baselines for this IE task: an unsupervised method based on a bags-of-n-grams similarity for extracting the needed tools in each repair step, and a deep-learning-based sequence labeling model for extracting the identity of disassembled parts. These baseline methods are integrated into a semi-automatic web-based annotator application that is also available along with the dataset.

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Hierarchy-aware Learning of Sequential Tool Usage via Semi-automatically Constructed Taxonomies
Nima Nabizadeh | Martin Heckmann | Dorothea Kolossa
Proceedings of the Joint Workshop on Multiword Expressions and Electronic Lexicons

When repairing a device, humans employ a series of tools that corresponds to the arrangement of the device components. Such sequences of tool usage can be learned from repair manuals, so that at each step, having observed the previously applied tools, a sequential model can predict the next required tool. In this paper, we improve the tool prediction performance of such methods by additionally taking the hierarchical relationships among the tools into account. To this aim, we build a taxonomy of tools with hyponymy and hypernymy relations from the data by decomposing all multi-word expressions of tool names. We then develop a sequential model that performs a binary prediction for each node in the taxonomy. The evaluation of the method on a dataset of repair manuals shows that encoding the tools with the constructed taxonomy and using a top-down beam search for decoding increases the prediction accuracy and yields an interpretable taxonomy as a potentially valuable byproduct.

2019

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Speaker-adapted neural-network-based fusion for multimodal reference resolution
Diana Kleingarn | Nima Nabizadeh | Martin Heckmann | Dorothea Kolossa
Proceedings of the 20th Annual SIGdial Meeting on Discourse and Dialogue

Humans use a variety of approaches to reference objects in the external world, including verbal descriptions, hand and head gestures, eye gaze or any combination of them. The amount of useful information from each modality, however, may vary depending on the specific person and on several other factors. For this reason, it is important to learn the correct combination of inputs for inferring the best-fitting reference. In this paper, we investigate appropriate speaker-dependent and independent fusion strategies in a multimodal reference resolution task. We show that without any change in the modality models, only through an optimized fusion technique, it is possible to reduce the error rate of the system on a reference resolution task by more than 50%.

2010

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WAPUSK20 - A Database for Robust Audiovisual Speech Recognition
Alexander Vorwerk | Xiaohui Wang | Dorothea Kolossa | Steffen Zeiler | Reinhold Orglmeister
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

Audiovisual speech recognition (AVSR) systems have been proven superior over audio-only speech recognizers in noisy environments by incorporating features of the visual modality. In order to develop reliable AVSR systems, appropriate simultaneously recorded speech and video data is needed. In this paper, we will introduce a corpus (WAPUSK20) that consists of audiovisual data of 20 speakers uttering 100 sentences each with four channels of audio and a stereoscopic video. The latter is intended to support more accurate lip tracking and the development of stereo data based normalization techniques for greater robustness of the recognition results. The sentence design has been adopted from the GRID corpus that has been widely used for AVSR experiments. Recordings have been made under acoustically realistic conditions in a usual office room. Affordable hardware equipment has been used, such as a pre-calibrated stereo camera and standard PC components. The software written to create this corpus was designed in MATLAB with help of hardware specific software provided by the hardware manufacturers and freely available open source software.