1,846 research outputs found
Macro-modelling via radial basis functionen nets
By the rising complexity and miniaturisation of the device's dimensions, the density of the conductors increases considerably. Referring to this, locally transient interactions between single physical values become apparent. Therefore, for the investigation and optimisation of integrated circuits it is essential to develop suitable models and simulation surroundings which allow for memory and timeefficient calculation of the behaviour. By means of the dynamic reconstruction theory and the radial basis functions nets the so-called black box models are provided. The description of black box models is derived from the input and output behaviour or so-called time series of a dynamic system. Concerning the time series, the black box model adapts its parameters via the extended Kalman filter. This paper provides a modelling approach that enables fast and efficient simulations.BMBF/01M3169 EInfineon Technologies AG/01M 3169
A Survey on Graph Kernels
Graph kernels have become an established and widely-used technique for
solving classification tasks on graphs. This survey gives a comprehensive
overview of techniques for kernel-based graph classification developed in the
past 15 years. We describe and categorize graph kernels based on properties
inherent to their design, such as the nature of their extracted graph features,
their method of computation and their applicability to problems in practice. In
an extensive experimental evaluation, we study the classification accuracy of a
large suite of graph kernels on established benchmarks as well as new datasets.
We compare the performance of popular kernels with several baseline methods and
study the effect of applying a Gaussian RBF kernel to the metric induced by a
graph kernel. In doing so, we find that simple baselines become competitive
after this transformation on some datasets. Moreover, we study the extent to
which existing graph kernels agree in their predictions (and prediction errors)
and obtain a data-driven categorization of kernels as result. Finally, based on
our experimental results, we derive a practitioner's guide to kernel-based
graph classification
Conversational AI Assistant Using Artificial Neural Networks: Implementation of a contextual chatbot framework in a Point-of-Sale system
Internship Report presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Business AnalyticsArtificial intelligence is changing the way how businesses are affronting their day-to-day difficulties.
Chatbots are the perfect demonstration of how simple tasks and queries such as customer support or
sales metrics and reporting could be solved without human intervention. This project introduced a
task-oriented chatbot framework for Spanish language in a Point-Of-Sale webpage. We applied Natural
Language Processing (NLP) techniques such as NER and evaluated two supervised learning methods:
(i) an Artificial Neural Network (ANN) and (ii) a Support Vector Machines (SVM) model to create a
contextualized chatbot that classifies the user’s intention in a text conversation, allowing bidirectional
human-to-machine communication. These intents could go from simple chitchatting to detailed
reports, always providing a natural flow in conversation. The results using an augmented and balanced
corpus suggested that ANN model performed statistically better than SVM. Additionally, a real-word
scenario with a small-talk survey made to five users gave positive feedback about the quality of
predictions. Finally, a software architecture using a PaaS computing service and an API framework was
proposed to implement this dialog system in further works
SAFE: Self-Attentive Function Embeddings for Binary Similarity
The binary similarity problem consists in determining if two functions are
similar by only considering their compiled form. Advanced techniques for binary
similarity recently gained momentum as they can be applied in several fields,
such as copyright disputes, malware analysis, vulnerability detection, etc.,
and thus have an immediate practical impact. Current solutions compare
functions by first transforming their binary code in multi-dimensional vector
representations (embeddings), and then comparing vectors through simple and
efficient geometric operations. However, embeddings are usually derived from
binary code using manual feature extraction, that may fail in considering
important function characteristics, or may consider features that are not
important for the binary similarity problem. In this paper we propose SAFE, a
novel architecture for the embedding of functions based on a self-attentive
neural network. SAFE works directly on disassembled binary functions, does not
require manual feature extraction, is computationally more efficient than
existing solutions (i.e., it does not incur in the computational overhead of
building or manipulating control flow graphs), and is more general as it works
on stripped binaries and on multiple architectures. We report the results from
a quantitative and qualitative analysis that show how SAFE provides a
noticeable performance improvement with respect to previous solutions.
Furthermore, we show how clusters of our embedding vectors are closely related
to the semantic of the implemented algorithms, paving the way for further
interesting applications (e.g. semantic-based binary function search).Comment: Published in International Conference on Detection of Intrusions and
Malware, and Vulnerability Assessment (DIMVA) 201
Machine Learning Small Molecule Properties in Drug Discovery
Machine learning (ML) is a promising approach for predicting small molecule
properties in drug discovery. Here, we provide a comprehensive overview of
various ML methods introduced for this purpose in recent years. We review a
wide range of properties, including binding affinities, solubility, and ADMET
(Absorption, Distribution, Metabolism, Excretion, and Toxicity). We discuss
existing popular datasets and molecular descriptors and embeddings, such as
chemical fingerprints and graph-based neural networks. We highlight also
challenges of predicting and optimizing multiple properties during hit-to-lead
and lead optimization stages of drug discovery and explore briefly possible
multi-objective optimization techniques that can be used to balance diverse
properties while optimizing lead candidates. Finally, techniques to provide an
understanding of model predictions, especially for critical decision-making in
drug discovery are assessed. Overall, this review provides insights into the
landscape of ML models for small molecule property predictions in drug
discovery. So far, there are multiple diverse approaches, but their
performances are often comparable. Neural networks, while more flexible, do not
always outperform simpler models. This shows that the availability of
high-quality training data remains crucial for training accurate models and
there is a need for standardized benchmarks, additional performance metrics,
and best practices to enable richer comparisons between the different
techniques and models that can shed a better light on the differences between
the many techniques.Comment: 46 pages, 1 figur
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