3,666 research outputs found
mARC: Memory by Association and Reinforcement of Contexts
This paper introduces the memory by Association and Reinforcement of Contexts
(mARC). mARC is a novel data modeling technology rooted in the second
quantization formulation of quantum mechanics. It is an all-purpose incremental
and unsupervised data storage and retrieval system which can be applied to all
types of signal or data, structured or unstructured, textual or not. mARC can
be applied to a wide range of information clas-sification and retrieval
problems like e-Discovery or contextual navigation. It can also for-mulated in
the artificial life framework a.k.a Conway "Game Of Life" Theory. In contrast
to Conway approach, the objects evolve in a massively multidimensional space.
In order to start evaluating the potential of mARC we have built a mARC-based
Internet search en-gine demonstrator with contextual functionality. We compare
the behavior of the mARC demonstrator with Google search both in terms of
performance and relevance. In the study we find that the mARC search engine
demonstrator outperforms Google search by an order of magnitude in response
time while providing more relevant results for some classes of queries
Federated Learning in Computer Vision
Federated Learning (FL) has recently emerged as a novel machine learning paradigm allowing to preserve privacy and to account for the distributed nature of the learning process in many real-world settings. Computer vision tasks deal with huge datasets often with critical privacy issues, therefore many federated learning approaches have been presented to exploit its distributed and privacy-preserving nature. Firstly, this paper introduces the different FL settings used in computer vision and the main challenges that need to be tackled. Then, it provides a comprehensive overview of the different strategies used for FL in vision applications and presents several different approaches for image classification, object detection, semantic segmentation and for focused settings in face recognition and medical imaging. For the various approaches the considered FL setting, the employed data and methodologies and the achieved results are thoroughly discussed
Exploring One-shot Semi-supervised Federated Learning with A Pre-trained Diffusion Model
Recently, semi-supervised federated learning (semi-FL) has been proposed to
handle the commonly seen real-world scenarios with labeled data on the server
and unlabeled data on the clients. However, existing methods face several
challenges such as communication costs, data heterogeneity, and training
pressure on client devices. To address these challenges, we introduce the
powerful diffusion models (DM) into semi-FL and propose FedDISC, a Federated
Diffusion-Inspired Semi-supervised Co-training method. Specifically, we first
extract prototypes of the labeled server data and use these prototypes to
predict pseudo-labels of the client data. For each category, we compute the
cluster centroids and domain-specific representations to signify the semantic
and stylistic information of their distributions. After adding noise, these
representations are sent back to the server, which uses the pre-trained DM to
generate synthetic datasets complying with the client distributions and train a
global model on it. With the assistance of vast knowledge within DM, the
synthetic datasets have comparable quality and diversity to the client images,
subsequently enabling the training of global models that achieve performance
equivalent to or even surpassing the ceiling of supervised centralized
training. FedDISC works within one communication round, does not require any
local training, and involves very minimal information uploading, greatly
enhancing its practicality. Extensive experiments on three large-scale datasets
demonstrate that FedDISC effectively addresses the semi-FL problem on non-IID
clients and outperforms the compared SOTA methods. Sufficient visualization
experiments also illustrate that the synthetic dataset generated by FedDISC
exhibits comparable diversity and quality to the original client dataset, with
a neglectable possibility of leaking privacy-sensitive information of the
clients
Transfer Learning in Human Activity Recognition: A Survey
Sensor-based human activity recognition (HAR) has been an active research
area, owing to its applications in smart environments, assisted living,
fitness, healthcare, etc. Recently, deep learning based end-to-end training has
resulted in state-of-the-art performance in domains such as computer vision and
natural language, where large amounts of annotated data are available. However,
large quantities of annotated data are not available for sensor-based HAR.
Moreover, the real-world settings on which the HAR is performed differ in terms
of sensor modalities, classification tasks, and target users. To address this
problem, transfer learning has been employed extensively. In this survey, we
focus on these transfer learning methods in the application domains of smart
home and wearables-based HAR. In particular, we provide a problem-solution
perspective by categorizing and presenting the works in terms of their
contributions and the challenges they address. We also present an updated view
of the state-of-the-art for both application domains. Based on our analysis of
205 papers, we highlight the gaps in the literature and provide a roadmap for
addressing them. This survey provides a reference to the HAR community, by
summarizing the existing works and providing a promising research agenda.Comment: 40 pages, 5 figures, 7 table
Identification of Informativeness in Text using Natural Language Stylometry
In this age of information overload, one experiences a rapidly growing over-abundance of written text. To assist with handling this bounty, this plethora of texts is now widely used to develop and optimize statistical natural language processing (NLP) systems. Surprisingly, the use of more fragments of text to train these statistical NLP systems may not necessarily lead to improved performance. We hypothesize that those fragments that help the most with training are those that contain the desired information. Therefore, determining informativeness in text has become a central issue in our view of NLP. Recent developments in this field have spawned a number of solutions to identify informativeness in text. Nevertheless, a shortfall of most of these solutions is their dependency on the genre and domain of the text. In addition, most of them are not efficient regardless of the natural language processing problem areas. Therefore, we attempt to provide a more general solution to this NLP problem.
This thesis takes a different approach to this problem by considering the underlying theme of a linguistic theory known as the Code Quantity Principle. This theory suggests that humans codify information in text so that readers can retrieve this information more efficiently. During the codification process, humans usually change elements of their writing ranging from characters to sentences. Examples of such elements are the use of simple words, complex words, function words, content words, syllables, and so on. This theory suggests that these elements have reasonable discriminating strength and can play a key role in distinguishing informativeness in natural language text. In another vein, Stylometry is a modern method to analyze literary style and deals largely with the aforementioned elements of writing. With this as background, we model text using a set of stylometric attributes to characterize variations in writing style present in it. We explore their effectiveness to determine informativeness in text. To the best of our knowledge, this is the first use of stylometric attributes to determine informativeness in statistical NLP. In doing so, we use texts of different genres, viz., scientific papers, technical reports, emails and newspaper articles, that are selected from assorted domains like agriculture, physics, and biomedical science. The variety of NLP systems that have benefitted from incorporating these stylometric attributes somewhere in their computational realm dealing with this set of multifarious texts suggests that these attributes can be regarded as an effective solution to identify informativeness in text. In addition to the variety of text genres and domains, the potential of stylometric attributes is also explored in some NLP application areas---including biomedical relation mining, automatic keyphrase indexing, spam classification, and text summarization---where performance improvement is both important and challenging. The success of the attributes in all these areas further highlights their usefulness
Graph enabled cross-domain knowledge transfer
The world has never been more connected, led by the information technology revolution in the past decades that has fundamentally changed the way people interact with each other using social networks. Consequently, enormous human activity data are collected from the business world and machine learning techniques are widely adopted to aid our decision processes. Despite of the success of machine learning in various application scenarios, there are still many questions that need to be well answered, such as optimizing machine learning outcomes when desired knowledge cannot be extracted from the available data. This naturally drives us to ponder if one can leverage some side information to populate the knowledge domain of their interest, such that the problems within that knowledge domain can be better tackled.
In this work, such problems are investigated and practical solutions are proposed. To leverage machine learning in any decision-making process, one must convert the given knowledge (for example, natural language, unstructured text) into representation vectors that can be understood and processed by machine learning model in their compatible language and data format. The frequently encountered difficulty is, however, the given knowledge is not rich or reliable enough in the first place. In such cases, one seeks to fuse side information from a separate domain to mitigate the gap between good representation learning and the scarce knowledge in the domain of interest. This approach is named Cross-Domain Knowledge Transfer. It is crucial to study the problem because of the commonality of scarce knowledge in many scenarios, from online healthcare platform analyses to financial market risk quantification, leaving an obstacle in front of us benefiting from automated decision making. From the machine learning perspective, the paradigm of semi-supervised learning takes advantage of large amount of data without ground truth and achieves impressive learning performance improvement. It is adopted in this dissertation for cross-domain knowledge transfer.
Furthermore, graph learning techniques are indispensable given that networks commonly exist in real word, such as taxonomy networks and scholarly article citation networks. These networks contain additional useful knowledge and are ought to be incorporated in the learning process, which serve as an important lever in solving the problem of cross-domain knowledge transfer. This dissertation proposes graph-based learning solutions and demonstrates their practical usage via empirical studies on real-world applications. Another line of effort in this work lies in leveraging the rich capacity of neural networks to improve the learning outcomes, as we are in the era of big data.
In contrast to many Graph Neural Networks that directly iterate on the graph adjacency to approximate graph convolution filters, this work also proposes an efficient Eigenvalue learning method that directly optimizes the graph convolution in the spectral space. This work articulates the importance of network spectrum and provides detailed analyses on the spectral properties in the proposed EigenLearn method, which well aligns with a series of CNN models that attempt to have meaningful spectral interpretation in designing graph neural networks. The disser-tation also addresses the efficiency, which can be categorized in two folds. First, by adopting approximate solutions it mitigates the complexity concerns for graph related algorithms, which are naturally quadratic in most cases and do not scale to large datasets. Second, it mitigates the storage and computation overhead in deep neural network, such that they can be deployed on many light-weight devices and significantly broaden the applicability. Finally, the dissertation is concluded by future endeavors
Graph Enabled Cross-Domain Knowledge Transfer
To leverage machine learning in any decision-making process, one must convert
the given knowledge (for example, natural language, unstructured text) into
representation vectors that can be understood and processed by machine learning
model in their compatible language and data format. The frequently encountered
difficulty is, however, the given knowledge is not rich or reliable enough in
the first place. In such cases, one seeks to fuse side information from a
separate domain to mitigate the gap between good representation learning and
the scarce knowledge in the domain of interest. This approach is named
Cross-Domain Knowledge Transfer. It is crucial to study the problem because of
the commonality of scarce knowledge in many scenarios, from online healthcare
platform analyses to financial market risk quantification, leaving an obstacle
in front of us benefiting from automated decision making. From the machine
learning perspective, the paradigm of semi-supervised learning takes advantage
of large amount of data without ground truth and achieves impressive learning
performance improvement. It is adopted in this dissertation for cross-domain
knowledge transfer. (to be continued
Music emotion recognition: a multimodal machine learning approach
Music emotion recognition (MER) is an emerging domain of the Music Information Retrieval (MIR) scientific community, and besides, music searches through emotions are one of the major selection preferred by web users. As the world goes to digital, the musical contents in online databases, such as Last.fm have expanded exponentially, which require substantial manual efforts for managing them and also keeping them updated. Therefore, the demand for innovative and adaptable search mechanisms, which can be personalized according to users’ emotional state, has gained increasing consideration in recent years. This thesis concentrates on addressing music emotion recognition problem by presenting several classification models, which were fed by textual features, as well as audio attributes extracted from the music. In this study, we build both supervised and semisupervised classification designs under four research experiments, that addresses the emotional role of audio features, such as tempo, acousticness, and energy, and also the impact of textual features extracted by two different approaches, which are TF-IDF and Word2Vec. Furthermore, we proposed a multi-modal approach by using a combined feature-set consisting of the features from the audio content, as well as from context-aware data. For this purpose, we generated a ground truth dataset containing over 1500 labeled song lyrics and also unlabeled big data, which stands for more than 2.5 million Turkish documents, for achieving to generate an accurate automatic emotion classification system. The analytical models were conducted by adopting several algorithms on the crossvalidated data by using Python. As a conclusion of the experiments, the best-attained performance was 44.2% when employing only audio features, whereas, with the usage of textual features, better performances were observed with 46.3% and 51.3% accuracy scores considering supervised and semi-supervised learning paradigms, respectively. As of last, even though we created a comprehensive feature set with the combination of audio and textual features, this approach did not display any significant improvement for classification performanc
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