64,740 research outputs found
Symbol Emergence in Robotics: A Survey
Humans can learn the use of language through physical interaction with their
environment and semiotic communication with other people. It is very important
to obtain a computational understanding of how humans can form a symbol system
and obtain semiotic skills through their autonomous mental development.
Recently, many studies have been conducted on the construction of robotic
systems and machine-learning methods that can learn the use of language through
embodied multimodal interaction with their environment and other systems.
Understanding human social interactions and developing a robot that can
smoothly communicate with human users in the long term, requires an
understanding of the dynamics of symbol systems and is crucially important. The
embodied cognition and social interaction of participants gradually change a
symbol system in a constructive manner. In this paper, we introduce a field of
research called symbol emergence in robotics (SER). SER is a constructive
approach towards an emergent symbol system. The emergent symbol system is
socially self-organized through both semiotic communications and physical
interactions with autonomous cognitive developmental agents, i.e., humans and
developmental robots. Specifically, we describe some state-of-art research
topics concerning SER, e.g., multimodal categorization, word discovery, and a
double articulation analysis, that enable a robot to obtain words and their
embodied meanings from raw sensory--motor information, including visual
information, haptic information, auditory information, and acoustic speech
signals, in a totally unsupervised manner. Finally, we suggest future
directions of research in SER.Comment: submitted to Advanced Robotic
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Preface : CAA 2010: Computer assisted assessment: supporting student learning
The Preface for the first special issue for the International Journal of e-Assessment highlights the role of the assessment for learning agenda. It also points to papers within the special issue which relate to:
(a) Overcoming the barriers to supporting student learning with computer-assisted assessment; (b) Marking and computer-assisted assessment; (c) Harnessing the technology to improve efficiency and pedagogy.
The papers in this issue stress the general recognition that times are changing and that assessment needs to become embedded in the teaching/learning cycle and not purely as a checking device for the awarding institution. These papers encourage us to rise to the challenge of developing more sophisticated computer-assisted assessment systems that support student learning and there is still a lot to do
SCANN: Synthesis of Compact and Accurate Neural Networks
Deep neural networks (DNNs) have become the driving force behind recent
artificial intelligence (AI) research. An important problem with implementing a
neural network is the design of its architecture. Typically, such an
architecture is obtained manually by exploring its hyperparameter space and
kept fixed during training. This approach is time-consuming and inefficient.
Another issue is that modern neural networks often contain millions of
parameters, whereas many applications and devices require small inference
models. However, efforts to migrate DNNs to such devices typically entail a
significant loss of classification accuracy. To address these challenges, we
propose a two-step neural network synthesis methodology, called DR+SCANN, that
combines two complementary approaches to design compact and accurate DNNs. At
the core of our framework is the SCANN methodology that uses three basic
architecture-changing operations, namely connection growth, neuron growth, and
connection pruning, to synthesize feed-forward architectures with arbitrary
structure. SCANN encapsulates three synthesis methodologies that apply a
repeated grow-and-prune paradigm to three architectural starting points.
DR+SCANN combines the SCANN methodology with dataset dimensionality reduction
to alleviate the curse of dimensionality. We demonstrate the efficacy of SCANN
and DR+SCANN on various image and non-image datasets. We evaluate SCANN on
MNIST and ImageNet benchmarks. In addition, we also evaluate the efficacy of
using dimensionality reduction alongside SCANN (DR+SCANN) on nine small to
medium-size datasets. We also show that our synthesis methodology yields neural
networks that are much better at navigating the accuracy vs. energy efficiency
space. This would enable neural network-based inference even on
Internet-of-Things sensors.Comment: 13 pages, 8 figure
Nonparametric Bayesian Double Articulation Analyzer for Direct Language Acquisition from Continuous Speech Signals
Human infants can discover words directly from unsegmented speech signals
without any explicitly labeled data. In this paper, we develop a novel machine
learning method called nonparametric Bayesian double articulation analyzer
(NPB-DAA) that can directly acquire language and acoustic models from observed
continuous speech signals. For this purpose, we propose an integrative
generative model that combines a language model and an acoustic model into a
single generative model called the "hierarchical Dirichlet process hidden
language model" (HDP-HLM). The HDP-HLM is obtained by extending the
hierarchical Dirichlet process hidden semi-Markov model (HDP-HSMM) proposed by
Johnson et al. An inference procedure for the HDP-HLM is derived using the
blocked Gibbs sampler originally proposed for the HDP-HSMM. This procedure
enables the simultaneous and direct inference of language and acoustic models
from continuous speech signals. Based on the HDP-HLM and its inference
procedure, we developed a novel double articulation analyzer. By assuming
HDP-HLM as a generative model of observed time series data, and by inferring
latent variables of the model, the method can analyze latent double
articulation structure, i.e., hierarchically organized latent words and
phonemes, of the data in an unsupervised manner. The novel unsupervised double
articulation analyzer is called NPB-DAA.
The NPB-DAA can automatically estimate double articulation structure embedded
in speech signals. We also carried out two evaluation experiments using
synthetic data and actual human continuous speech signals representing Japanese
vowel sequences. In the word acquisition and phoneme categorization tasks, the
NPB-DAA outperformed a conventional double articulation analyzer (DAA) and
baseline automatic speech recognition system whose acoustic model was trained
in a supervised manner.Comment: 15 pages, 7 figures, Draft submitted to IEEE Transactions on
Autonomous Mental Development (TAMD
Coal Seam Thickness Estimation Using GPR and Higher Order Statistics - The Near-Surface Case
A novel pattern recognition-based approach to detect near-surface interfaces using ground penetrating radar (GPR) has been reported in [1]. The approach was used to successfully detect interfaces within 5 cm of the ground surface. This technique has been adapted for the important task of layer thickness estimation in the near-surface range. This is inherently a difficult problem to solve in practice because the radar echo is often dominated by unwanted components such as antenna crosstalk and ring-down, ground reflection effects and clutter. Features derived from the bispectrum and a nearest-neighbour classifier have been utilized for this processing task. It is shown that unlike traditional second order correlation based methods such as matched filtering which can fail in known conditions, layer thickness estimation using this approach can be reliably extended to the near-surface region
Modeling Topic and Role Information in Meetings using the Hierarchical Dirichlet Process
Abstract. In this paper, we address the modeling of topic and role information in multiparty meetings, via a nonparametric Bayesian model called the hierarchical Dirichlet process. This model provides a powerful solution to topic modeling and a flexible framework for the incorporation of other cues such as speaker role information. We present our modeling framework for topic and role on the AMI Meeting Corpus, and illustrate the effectiveness of the approach in the context of adapting a baseline language model in a large-vocabulary automatic speech recognition system for multiparty meetings. The adapted LM produces significant improvements in terms of both perplexity and word error rate.
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