209 research outputs found
On the Complementarity of Images and Text for the Expression of Emotions in Social Media
Authors of posts in social media communicate their emotions and what causes
them with text and images. While there is work on emotion and stimulus
detection for each modality separately, it is yet unknown if the modalities
contain complementary emotion information in social media. We aim at filling
this research gap and contribute a novel, annotated corpus of English
multimodal Reddit posts. On this resource, we develop models to automatically
detect the relation between image and text, an emotion stimulus category and
the emotion class. We evaluate if these tasks require both modalities and find
for the image-text relations, that text alone is sufficient for most categories
(complementary, illustrative, opposing): the information in the text allows to
predict if an image is required for emotion understanding. The emotions of
anger and sadness are best predicted with a multimodal model, while text alone
is sufficient for disgust, joy, and surprise. Stimuli depicted by objects,
animals, food, or a person are best predicted by image-only models, while
multimodal models are most effective on art, events, memes, places, or
screenshots.Comment: accepted for WASSA 2022 at ACL 202
Visually Grounded Meaning Representations
In this paper we address the problem of grounding distributional representations of lexical meaning. We introduce a new
model which uses stacked autoencoders to learn higher-level representations from textual and visual input. The visual modality is
encoded via vectors of attributes obtained automatically from images. We create a new large-scale taxonomy of 600 visual attributes
representing more than 500 concepts and 700K images. We use this dataset to train attribute classifiers and integrate their predictions
with text-based distributional models of word meaning. We evaluate our model on its ability to simulate word similarity judgments and
concept categorization. On both tasks, our model yields a better fit to behavioral data compared to baselines and related models which
either rely on a single modality or do not make use of attribute-based input
Learning visually grounded meaning representations
Humans possess a rich semantic knowledge of words and concepts which captures the
perceivable physical properties of their real-world referents and their relations. Encoding
this knowledge or some of its aspects is the goal of computational models of
semantic representation and has been the subject of considerable research in cognitive
science, natural language processing, and related areas. Existing models have
placed emphasis on different aspects of meaning, depending ultimately on the task at
hand. Typically, such models have been used in tasks addressing the simulation of behavioural
phenomena, e.g., lexical priming or categorisation, as well as in natural language
applications, such as information retrieval, document classification, or semantic
role labelling. A major strand of research popular across disciplines focuses on models
which induce semantic representations from text corpora. These models are based on
the hypothesis that the meaning of words is established by their distributional relation
to other words (Harris, 1954). Despite their widespread use, distributional models of
word meaning have been criticised as ‘disembodied’ in that they are not grounded in
perception and action (Perfetti, 1998; Barsalou, 1999; Glenberg and Kaschak, 2002).
This lack of grounding contrasts with many experimental studies suggesting that meaning
is acquired not only from exposure to the linguistic environment but also from our
interaction with the physical world (Landau et al., 1998; Bornstein et al., 2004). This
criticism has led to the emergence of new models aiming at inducing perceptually
grounded semantic representations. Essentially, existing approaches learn meaning
representations from multiple views corresponding to different modalities, i.e. linguistic
and perceptual input. To approximate the perceptual modality, previous work has
relied largely on semantic attributes collected from humans (e.g., is round, is sour), or
on automatically extracted image features. Semantic attributes have a long-standing
tradition in cognitive science and are thought to represent salient psychological aspects
of word meaning including multisensory information. However, their elicitation
from human subjects limits the scope of computational models to a small number of
concepts for which attributes are available.
In this thesis, we present an approach which draws inspiration from the successful
application of attribute classifiers in image classification, and represent images and
the concepts depicted by them by automatically predicted visual attributes. To this
end, we create a dataset comprising nearly 700K images and a taxonomy of 636 visual
attributes and use it to train attribute classifiers. We show that their predictions
can act as a substitute for human-produced attributes without any critical information
loss. In line with the attribute-based approximation of the visual modality, we represent
the linguistic modality by textual attributes which we obtain with an off-the-shelf
distributional model. Having first established this core contribution of a novel modelling
framework for grounded meaning representations based on semantic attributes,
we show that these can be integrated into existing approaches to perceptually grounded
representations. We then introduce a model which is formulated as a stacked autoencoder
(a variant of multilayer neural networks), which learns higher-level meaning representations
by mapping words and images, represented by attributes, into a common
embedding space. In contrast to most previous approaches to multimodal learning using
different variants of deep networks and data sources, our model is defined at a finer
level of granularity—it computes representations for individual words and is unique in
its use of attributes as a means of representing the textual and visual modalities.
We evaluate the effectiveness of the representations learnt by our model by assessing
its ability to account for human behaviour on three semantic tasks, namely word
similarity, concept categorisation, and typicality of category members. With respect to
the word similarity task, we focus on the model’s ability to capture similarity in both
the meaning and appearance of the words’ referents. Since existing benchmark datasets
on word similarity do not distinguish between these two dimensions and often contain
abstract words, we create a new dataset in a large-scale experiment where participants
are asked to give two ratings per word pair expressing their semantic and visual
similarity, respectively. Experimental results show that our model learns meaningful
representations which are more accurate than models based on individual modalities or
different modality integration mechanisms. The presented model is furthermore able to
predict textual attributes for new concepts given their visual attribute predictions only,
which we demonstrate by comparing model output with human generated attributes.
Finally, we show the model’s effectiveness in an image-based task on visual category
learning, in which images are used as a stand-in for real-world objects
Kundenkenntnis im Handel - Ausprägungen, Herkunft und Wirkungen
Die Bedeutung der Kundenkenntnis für den Markterfolg der Anbieter ist unbestritten. Dennoch wissen wir wenig darüber, wie gut die Anbieter ihre Kunden kennen. Dies gilt auch für den Handel. Deshalb befasst sich die hier vorgelegte Publikation mit der Ausprägung der Kundenkenntnis im Handel, aber auch mit den Quellen und Determinanten dieser Kenntnis und mit ihren Auswirkungen auf der Anbieter- und auf der Kundenseite. Beachtung finden alle möglichen Quellen der Kundenkenntnis, vor allem aber die Kundenkontakte. Im Einzelnen werden nicht nur relevante Theorien bemüht, sondern auch erste, differenzierte Forschungsergebnisse zur Ausprägung der Kundenkenntnis, zu den Einflussfaktoren und den Auswirkungen dieser Kenntnis präsentiert. Folgerungen für die künftige Forschung und für das Wissensmanagement im Handel schließen das Werk ab
Grounded Models of Semantic Representation
A popular tradition of studying semantic representation has been driven by the assumption that word meaning can be learned from the linguistic environment, despite ample evidence suggesting that language is grounded in perception and action. In this paper we present a comparative study of models that represent word meaning based on linguistic and perceptual data. Linguistic information is approximated by naturally occurring corpora and sensorimotor experience by feature norms (i.e., attributes native speakers consider important in describing the meaning of a word). The models differ in terms of the mechanisms by which they integrate the two modalities. Experimental results show that a closer correspondence to human data can be obtained by uncovering latent information shared among the textual and perceptual modalities rather than arriving at semantic knowledge by concatenating the two.
Models of Semantic Representation with Visual Attributes
We consider the problem of grounding the meaning of words in the physical world and focus on the visual modality which we represent by visual attributes. We create a new large-scale taxonomy of visual attributes covering more than 500 concepts and their corresponding 688K images. We use this dataset to train attribute classifiers and integrate their predictions with text-based distributional models of word meaning. We show that these bimodal models give a better fit to human word association data compared to amodal models and word representations based on handcrafted norming data.
Entwicklung eines elektrischen Carsharing-Angebots für den ländlichen Raum
Carsharing hat deutschlandweit das Potenzial, einen Beitrag zur Verringerung der Treibhausgase im
Tansportsektor leisten zu können. Dabei ist es fraglich, ob sich erfolgreiche Carsharing-Angebote auch für
den ländlichen Raum entwickeln lassen. Um herauszufinden, welche besonderen Herausforderungen aus
Sicht der Nutzerinnen und Nutzer im ländlichen Raum bestehen, wurde in einem Partizipationsprozess mit
Bürgerinnen und Bürger einer Ortschaft im ländlichen Raum ein elektrisches Carsharing-Angebot
entwickelt. Wichtige Einflussfaktoren für die Nutzung des Carsharing-Angebots waren laut einer Umfrage
mit 190 Bürgerinnen und Bürgern die Nützlichkeit im Alltag, der Spaß an der Nutzung und die
Erreichbarkeit des Standorts. Qualitative Interviews mit 21 Bürgerinnen und Bürgern bestätigten diese
Ergebnisse und lieferten Details zu deren Hintergründen. Zudem wurde die Fokussierung auf bestimmte
Zielgruppen als wichtig gesehen. In anschließenden Workshops mit Bürgerinnen und Bürgern wurden darauf
aufbauend konkrete Ideen für passende Carsharing-Modelle entwickelt. Dabei wurde unter anderem eine
App mit einer Funktion zum Angebot von Mitfahrgelegenheiten gewünscht, um das Gemeinschaftsgefühl bei
der Nutzung des Carsharing zu fördern. Insgesamt zeigt sich, dass es einige spezielle Anforderungen der
Bürgerinnen und Bürger im ländlichen Raum hinsichtlich eines Carsharing-Angebots gibt, denen vor allem
eine soziale Ausrichtung gemein ist. Um die größten Erfolgschancen mit einem Carsharing-Angebot im
ländlichen Raum zu haben, sollten diese Wünsche mit maßgeschneiderten Lösungen adressiert werden
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