802,545 research outputs found
Class-Weighted Convolutional Features for Visual Instance Search
Image retrieval in realistic scenarios targets large dynamic datasets of
unlabeled images. In these cases, training or fine-tuning a model every time
new images are added to the database is neither efficient nor scalable.
Convolutional neural networks trained for image classification over large
datasets have been proven effective feature extractors for image retrieval. The
most successful approaches are based on encoding the activations of
convolutional layers, as they convey the image spatial information. In this
paper, we go beyond this spatial information and propose a local-aware encoding
of convolutional features based on semantic information predicted in the target
image. To this end, we obtain the most discriminative regions of an image using
Class Activation Maps (CAMs). CAMs are based on the knowledge contained in the
network and therefore, our approach, has the additional advantage of not
requiring external information. In addition, we use CAMs to generate object
proposals during an unsupervised re-ranking stage after a first fast search.
Our experiments on two public available datasets for instance retrieval,
Oxford5k and Paris6k, demonstrate the competitiveness of our approach
outperforming the current state-of-the-art when using off-the-shelf models
trained on ImageNet. The source code and model used in this paper are publicly
available at http://imatge-upc.github.io/retrieval-2017-cam/.Comment: To appear in the British Machine Vision Conference (BMVC), September
201
Knowledge discovery in biological databases : a neural network approach
Knowledge discovery, in databases, also known as data mining, is aimed to find significant information from a set of data. The knowledge to be mined from the dataset may refer to patterns, association rules, classification and clustering rules, and so forth. In this dissertation, we present a neural network approach to finding knowledge in biological databases. Specifically, we propose new methods to process biological sequences in two case studies: the classification of protein sequences and the prediction of E. Coli promoters in DNA sequences. Our proposed methods, based oil neural network architectures combine techniques ranging from Bayesian inference, coding theory, feature selection, dimensionality reduction, to dynamic programming and machine learning algorithms. Empirical studies show that the proposed methods outperform previously published methods and have excellent performance on the latest dataset. We have implemented the proposed algorithms into an infrastructure, called Genome Mining, developed for biosequence classification and recognition
Neural Collaborative Ranking
Recommender systems are aimed at generating a personalized ranked list of
items that an end user might be interested in. With the unprecedented success
of deep learning in computer vision and speech recognition, recently it has
been a hot topic to bridge the gap between recommender systems and deep neural
network. And deep learning methods have been shown to achieve state-of-the-art
on many recommendation tasks. For example, a recent model, NeuMF, first
projects users and items into some shared low-dimensional latent feature space,
and then employs neural nets to model the interaction between the user and item
latent features to obtain state-of-the-art performance on the recommendation
tasks. NeuMF assumes that the non-interacted items are inherent negative and
uses negative sampling to relax this assumption. In this paper, we examine an
alternative approach which does not assume that the non-interacted items are
necessarily negative, just that they are less preferred than interacted items.
Specifically, we develop a new classification strategy based on the widely used
pairwise ranking assumption. We combine our classification strategy with the
recently proposed neural collaborative filtering framework, and propose a
general collaborative ranking framework called Neural Network based
Collaborative Ranking (NCR). We resort to a neural network architecture to
model a user's pairwise preference between items, with the belief that neural
network will effectively capture the latent structure of latent factors. The
experimental results on two real-world datasets show the superior performance
of our models in comparison with several state-of-the-art approaches.Comment: Proceedings of the 2018 ACM on Conference on Information and
Knowledge Managemen
Principles of Modeling in Information Communication Systems and Networks
The authors present in this entry chapter the basic rubrics of models, modeling, and simulation, an un-
derstanding of which is indispensible for the comprehension of subsequent chapters of this text on the
all-important topic of modeling and simulation in Information Communication Systems and Networks
(ICSN). A good example is the case of analyzing simulation results of traffic models as a tool for investigat-
ing network behavioral pattarns as it affects the transmitted content (Atayero, et al., 2013). The various
classifications of models are discussed, for example classification based on the degree of semblance to
the original object (i.e. isomorphism). Various fundamental terminologies without the knowledge of which
the concepts and models and modeling cannot be properly understood are explained. Model stuctures
are highlighted and discussed. The methodological basis of formalizing complex system structures is
presented. The concept of componential approach to modeling is presented and the necessary stages of
mathematical model formation are examined and explained. The chapter concludes with a presentation
of the concept of simulation vis-Ă -vis information communication systems and networks
Context sensitive optical character recognition using neural networks and hidden Markov models
This thesis investigates a method for using contextual information in text recognition. This is based on the premise that, while reading, humans recognize words with missing or garbled characters by examining the surrounding characters and then selecting the appropriate character. The correct character is chosen based on an inherent knowledge of the language and spelling techniques. We can then model this statistically. The approach taken by this Thesis is to combine feature extraction techniques, Neural Networks and Hidden Markov Modeling. This method of character recognition involves a three step process: pixel image preprocessing, neural network classification and context interpretation. Pixel image preprocessing applies a feature extraction algorithm to original bit mapped images, which produces a feature vector for the original images which are input into a neural network. The neural network performs the initial classification of the characters by producing ten weights, one for each character. The magnitude of the weight is translated into the confidence the network has in each of the choices. The greater the magnitude and separation, the more confident the neural network is of a given choice. The output of the neural network is the input for a context interpreter. The context interpreter uses Hidden Markov Modeling (HMM) techniques to determine the most probable classification for all characters based on the characters that precede that character and character pair statistics. The HMMs are built using an a priori knowledge of the language: a statistical description of the probabilities of digrams. Experimentation and verification of this method combines the development and use of a preprocessor program, a Cascade Correlation Neural Network and a HMM context interpreter program. Results from these experiments show the neural network successfully classified 88.2 percent of the characters. Expanding this to the word level, 63 percent of the words were correctly identified. Adding the Hidden Markov Modeling improved the word recognition to 82.9 percent
After-Stroke Arm Paresis Detection using Kinematic Data
This paper presents an approach for detecting unilateral arm
paralysis/weakness using kinematic data. Our method employs temporal
convolution networks and recurrent neural networks, guided by knowledge
distillation, where we use inertial measurement units attached to the body to
capture kinematic information such as acceleration, rotation, and flexion of
body joints during an action. This information is then analyzed to recognize
body actions and patterns. Our proposed network achieves a high paretic
detection accuracy of 97.99\%, with an action classification accuracy of
77.69\%, through knowledge sharing. Furthermore, by incorporating causal
reasoning, we can gain additional insights into the patient's condition, such
as their Fugl-Meyer assessment score or impairment level based on the machine
learning result. Overall, our approach demonstrates the potential of using
kinematic data and machine learning for detecting arm paralysis/weakness. The
results suggest that our method could be a useful tool for clinicians and
healthcare professionals working with patients with this condition.Comment: submitted to IEEE Symposium Series on Computational Intelligenc
Real-time analytics for complex structure data
University of Technology Sydney. Faculty of Engineering and Information Technology.The advancement of data acquisition and analysis technology has resulted in many real-world data being dynamic and containing rich content and structured information. More specifically, with the fast development of information technology, many current real-world data are always featured with dynamic changes, such as new instances, new nodes and edges, and modifications to the node content. Different from traditional data, which are represented as feature vectors, data with complex relationships are often represented as graphs to denote the content of the data entries and their structural relationships, where instances (nodes) are not only characterized by the content but are also subject to dependency relationships. Plus, real-time availability is one of outstanding features of today’s data. Real-time analytics is dynamic analysis and reporting based on data entered into a system before the actual time of use. Real-time analytics emphasizes on deriving immediate knowledge from dynamic data sources, such as data streams, and knowledge discovery and pattern mining are facing complex, dynamic data sources. However, how to combine structure information and node content information for accurate and real-time data mining is still a big challenge. Accordingly, this thesis focuses on real-time analytics for complex structure data. We explore instance correlation in complex structure data and utilises it to make mining tasks more accurate and applicable. To be specific, our objective is to combine node correlation with node content and utilize them for three different tasks, including (1) graph stream classification, (2) super-graph classification and clustering, and (3) streaming network node classification.
Understanding the role of structured patterns for graph classification: the thesis introduces existing works on data mining from an complex structured perspective. Then we propose a graph factorization-based fine-grained representation model, where the main objective is to use linear combinations of a set of discriminative cliques to represent graphs for learning. The optimization-oriented factorization approach ensures minimum information loss for graph representation, and also avoids the expensive sub-graph isomorphism validation process. Based on this idea, we propose a novel framework for fast graph stream classification.
A new structure data classification algorithm: The second method introduces a new super-graph classification and clustering problem. Due to the inherent complex structure representation, all existing graph classification methods cannot be applied to super-graph classification. In the thesis, we propose a weighted random walk kernel which calculates the similarity between two super-graphs by assessing (a) the similarity between super-nodes of the super-graphs, and (b) the common walks of the super-graphs. Our key contribution is: (1) a new super-node and super-graph structure to enrich existing graph representation for real-world applications; (2) a weighted random walk kernel considering node and structure similarities between graphs; (3) a mixed-similarity considering structured content inside super-nodes and structural dependency between super-nodes; and (4) an effective kernel-based super-graph classification method with sound theoretical basis. Empirical studies show that the proposed methods significantly outperform the state-of-the-art methods.
Real-time analytics framework for dynamic complex structure data: For streaming networks, the essential challenge is to properly capture the dynamic evolution of the node content and node interactions in order to support node classification. While streaming networks are dynamically evolving, for a short temporal period, a subset of salient features are essentially tied to the network content and structures, and therefore can be used to characterize the network for classification. To achieve this goal, we propose to carry out streaming network feature selection (SNF) from the network, and use selected features as gauge to classify unlabeled nodes. A Laplacian based quality criterion is proposed to guide the node classification, where the Laplacian matrix is generated based on node labels and network topology structures. Node classification is achieved by finding the class label that results in the minimal gauging value with respect to the selected features. By frequently updating the features selected from the network, node classification can quickly adapt to the changes in the network for maximal performance gain. Experiments and comparisons on real-world networks demonstrate that SNOC is able to capture dynamics in the network structures and node content, and outperforms baseline approaches with significant performance gain
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