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2013 2nd International Symposium on Computer,Communication,Control and Automation(3CA 2013)

作者： Po-Whei Huang Yung-Kuan Chan Chia-Yi Chuang Hao-Cheng Wang Department of Computer Science and Engineering National Chung Hsing University Department of Management Information Systems National Chung Hsing University Innovative Digi Tech-Enabled Applications & Services(IDEAS)Institute of Information Industry

ISBN: (纸本)9781629939773

The image data hiding technique can embed the secret message into the digital image. For military or medical applications the reversible data hiding technique is preferred because it offers the advantage to recover the original image after the message extraction, yet it still maintains the reversibility. In order to achieve reversibility, we propose a reversible data hiding algorithm that explores the spatial and frequency domains. predictive coding is employed to embed the secret message in the spatial domain. The proposed algorithm applies an integer-to-integer transformation to convert the image originating in the spatial domain into the frequency domain. We then modify the high frequency coefficients only when embedding the secret message. Consequently, the low frequency coefficients are unchanged enabling the embedded image to preserve the image quality due to the hidden message. In addition, the algorithm further increases the embedding capacity because it takes advantage of both the spatial and frequency domains.

关键词： Data hiding reversible data embedding predictive coding wavelet transform

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Efficient learning from explanation of prediction errors in streaming data

Efficient learning from explanation of prediction errors in ...

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IEEE International Conference on Big Data

作者： Bonny Banerjee Jayanta K. Dutta Dept. of Electrical & Computer Engineering The University of Memphis Memphis TN USA

ISBN: (纸本)9781479912940

Streaming data from different kinds of sensors contributes to Big Data in a significant way. Recognizing the norms and abnormalities in such spatiotemporal data is a challenging problem. We present a general-purpose biologically-plausible computational model, called SELP, for learning the norms or invariances as features in an unsupervised and online manner from explanations of saliencies or surprises in the data. Given streaming data, this model runs a relentless cycle of Surprise → Explain → Learn → Predict involving the real external world and its internal model, and hence the name. The key characteristic of the model is its efficiency, crucial for streaming Big Data applications, which stems from two functionalities exploited at each sampling instant - it operates on the change in the state of data between consecutive sampling instants as opposed to the entire state of data, and it learns only from surprise or prediction error to update its internal state as opposed to learning from the entire input. The former allows the model to concentrate its computational resources on spatial regions of the data changing most frequently and ignore others, while the latter allows it to concentrate on those instants of time when its prediction is erroneous and ignore others. The model is implemented in a neural network architecture. We show the performance of the network in learning and retaining sequences of handwritten numerals. When exposed to natural videos acquired by a camera mounted on a cat's head, the neurons learn receptive fields resembling simple cells in the primary visual cortex. The model leads to an agent-dependent framework for mining streaming data where the agent interprets and learns from the data in order to update its internal model.

关键词： Neurons Data models predictive models Computational modeling Feedforward neural networks predictive coding Biological system modeling

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Beyond the reward principle: Consciousness as precision seeking

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Neuropsychoanalysis 2013年第1期15卷 33-38页

作者： Fotopoulou, Aikaterini King’s College London Institute of Psychiatry London United Kingdom

I use an influential computational theory of brain function—the free-energy principle—to suggest three points of added complexity to Mark Solms’s intriguing descriptions of the embodied mind: (1) The link between ego and cognitive automaticity is not as straightforward as Solms suggests;instead, cognition strives for both inference and flexibility in relation to the changing world and the inflexible drives. (2) Affective consciousness may primarily map the degree of uncertainty (not pleasure) of internal bodily signals;subcortical areas are the neurobiological source of this facet of consciousness that in itself is likely to be localized among many, distributed brain areas. (3) Our innate motivational systems—the id—ultimately serve the same optimization principle as the ego;however, unlike the latter, they call for automaticity in behavior, on the basis of innate unconscious priors that are fulfilled by instinctual “e-motions” and other reflexes, understood as evolutionarily defined, primitive forms of active and perceptual inference. © 2013, Taylor & Francis Group, LLC. All rights reserved.

关键词： Consciousness Embodiment Emotion Free energy Motivation predictive coding

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LOW COMPLEXITY M-CHANNEL MULTIPLE DESCRIPTION coding WITH TWO-RATE predictive coding AND STAGGERED QUANTIZATION

LOW COMPLEXITY <i>M</i>-CHANNEL MULTIPLE DESCRIPTION CODING ...

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15th IEEE International Conference on Image Processing (ICIP 2008)

作者： Samarawickrama, Upul Liang, Jie Simon Fraser Univ Sch Engn Sci Burnaby BC V5A 1S6 Canada

ISBN: (纸本)9781424417650

This paper presents a new low complexity multiple description coding (MDC) method that can generate any number of descriptions. For correlated sources, a special DPCM encoder is used in each description, such that it carries higher rate information of a subset of the samples and lower rate information of the rest. The lower rate codings in different descriptions are designed to be mutually refinable using staggered scalar quantizers. The closed-form expression of the expected distortion is derived when an arbitrary subset of the descriptions are received. Experimental results on natural images using lapped transform show that the proposed method is competent with the state-of-the-art multiple description image coders.

关键词： Multiple description coding predictive coding information theory image coding

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Segmentation of Source Symbols for Adaptive Arithmetic coding

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IEEE TRANSACTIONS ON BROADCASTING 2012年第2期58卷 228-235页

作者： Zhang, Liang Wang, Demin Zheng, Dong Commun Res Ctr Canada Ottawa ON K2H 8S2 Canada

Adaptive arithmetic coding is a general technique for coding source symbols of a stochastic process based on an adaptive model. The adaptive model provides measures of the statistics of source symbols and is updated, along with encoding/decoding processes, when more encoded/decoded symbols are fed as samples to the adaptive model. The coding performance depends on how well the adaptive model fits the statistics of source symbols. If the number of source symbols is large and the number of samples is small, the adaptive model may not be able to provide valid measures of the statistics, which results in an inefficient coding performance of the adaptive arithmetic coder. To this end, this paper presents segmentation of source symbols to improve the performance of the adaptive arithmetic coder. Each source symbol is divided into several segments. Each segment is separately coded with an adaptive arithmetic coder. With this division, possible values of each segment are concentrated within a small range. Given the limited number of samples, this concentration leads to a better fit of the adaptive model to the statistics of source symbols and therefore to an improvement of the coding efficiency. The proposed coding algorithm is applied to lossless motion vector coding for video transmission as an application example to show its performance improvement and coding gains.

关键词： Adaptive coding predictive coding signal representations vector quantization video coding video compression

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A New Encoder for Continuous-Time Gaussian Signals With Fixed Rate and Reconstruction Delay

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第6期60卷 3052-3064页

作者： Marelli, Damian Mahata, Kaushik Fu, Minyue Univ Newcastle Sch Elect Engn & Comp Sci Callaghan NSW 2308 Australia Zhejiang Univ Dept Control Sci & Engn Hangzhou Zhejiang Peoples R China

In this paper, we propose a method for encoding continuous-time Gaussian signals subject to a usual data rate constraint and, more importantly, a reconstruction delay constraint. We first apply a Karhunen-Loeve decomposition to reparameterize the continuous-time signal as a discrete sequence of vectors. We then study the optimal recursive quantization of this sequence of vectors. Since the optimal scheme turns out to have a very cumbersome design, we consider a simplified method, for which a numerical example suggests that the incurred performance loss is negligible. In this simplified method, we first build a state space model for the vector sequence and then use Bayessian tracking to sequentially encode each vector. The tracking task is performed using particle filtering. Numerical experiments show that the proposed approach offers visible advantages over other available approaches, especially when the reconstruction delay is small.

关键词： Bayesian methods continuous-time signals particle filters predictive coding quantization state-space methods transform coding

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Responses to deviants are modulated by subthreshold variability of the standard

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PSYCHOPHYSIOLOGY 2012年第1期49卷 31-42页

作者： Daikhin, Luba Ahissar, Merav Hebrew Univ Jerusalem Dept Psychol & Cognit Sci IL-91905 Jerusalem Israel Hebrew Univ Jerusalem Edmond & Lily Safra Ctr Brain Sci IL-91905 Jerusalem Israel

Auditory mechanisms automatically detect both basic features of sounds and the rules governing their presentation. In the oddball paradigm, the auditory system detects the sameness (or no-variability) rule when the same reference tone is consistently repeated. We used two oddball protocols, the classical one with a fixed reference and a modified one with a jittered reference, to determine whether the auditory system can detect subthreshold violations of sameness. We found that the response to the repeated standard was not modified by the small jitter. However, the response to the frequency oddball was smaller under the jittered protocol, indicating hypersensitivity to sameness. The sensitivity to jitter was largest when the oddball deviated by 8%, was smaller for 40%, and disappeared at 100% deviation, indicating that sensitivity to sameness is context dependent;namely, it is scaled with respect to the overall range of stimuli.

关键词： Cognition Learning memory Implicit processing Surprise predictive coding EEG ERP

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Human auditory cortex is sensitive to the perceived clarity of speech

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NEUROIMAGE 2012年第2期60卷 1490-1502页

作者： Wild, Conor J. Davis, Matthew H. Johnsrude, Ingrid S. Queens Univ Ctr Neurosci Studies Kingston ON K7L 3N6 Canada MRC Cognit & Brain Sci Unit Cambridge England Linkoping Univ Linnaeus Ctr HEAD Linkoping Sweden Queens Univ Dept Psychol Kingston ON K7L 3N6 Canada

Feedback connections among auditory cortical regions may play an important functional role in processing naturalistic speech, which is typically considered a problem solved through serial feed-forward processing stages. Here, we used fMRI to investigate whether activity within primary auditory cortex (PAC) is sensitive to the perceived clarity of degraded sentences. A region-of-interest analysis using probabilistic cytoarchitectonic maps of PAC revealed a modulation of activity, in the most primary-like subregion (area Te1.0). related to the intelligibility of naturalistic speech stimuli that cannot be driven by stimulus differences. Importantly, this effect was unique to those conditions accompanied by a perceptual increase in clarity. Connectivity analyses suggested sources of input to PAC are higher-order temporal, frontal and motor regions. These findings are incompatible with feed-forward models of speech perception, and suggest that this problem belongs amongst modern perceptual frameworks in which the brain actively predicts sensory input, rather than just passively receiving it. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.

关键词： fMRI Primary auditory cortex Speech perception predictive coding Top-down influences Superior temporal sulcus Premotor cortex Inferior frontal gyrus Feedback connections

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Attention Reverses the Effect of Prediction in Silencing Sensory Signals

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CEREBRAL CORTEX 2012年第9期22卷 2197-2206页

作者： Kok, Peter Rahnev, Dobromir Jehee, Janneke F. M. Lau, Hakwan C. de Lange, Floris P. Radboud Univ Nijmegen Donders Inst Brain Cognit & Behav NL-6500 HB Nijmegen Netherlands Columbia Univ Dept Psychol New York NY 10027 USA

predictive coding models suggest that predicted sensory signals are attenuated (silencing of prediction error). These models, though influential, are challenged by the fact that prediction sometimes seems to enhance rather than reduce sensory signals, as in the case of attentional cueing experiments. One possible explanation is that in these experiments, prediction (i.e., stimulus probability) is confounded with attention (i.e., task relevance), which is known to boost rather than reduce sensory signal. However, recent theoretical work on predictive coding inspires an alternative hypothesis and suggests that attention and prediction operate synergistically to improve the precision of perceptual inference. This model posits that attention leads to heightened weighting of sensory evidence, thereby reversing the sensory silencing by prediction. Here, we factorially manipulated attention and prediction in a functional magnetic resonance imaging study and distinguished between these 2 hypotheses. Our results support a predictive coding model wherein attention reverses the sensory attenuation of predicted signals.

关键词： expectation fMRI predictive coding spatial attention

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Mismatch Negativity Encoding of Prediction Errors Predicts S-ketamine-Induced Cognitive Impairments

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NEUROPSYCHOPHARMACOLOGY 2012年第4期37卷 865-875页

作者： Schmidt, Andre Bachmann, Rosilla Kometer, Michael Csomor, Philipp A. Stephan, Klaas E. Seifritz, Erich Vollenweider, Franz X. Univ Zurich Univ Hosp Psychiat CH-8029 Zurich Switzerland Univ Zurich Dept Econ Lab Social & Neural Syst Res CH-8029 Zurich Switzerland Univ Hosp Psychiat Clin Affect Disorders & Gen Psychiat Zurich Switzerland UCL Wellcome Dept Neuroimaging London England

Psychotomimetics like the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine and the 5-hydroxytryptamine2A receptor (5-HT2AR) agonist psilocybin induce psychotic symptoms in healthy volunteers that resemble those of schizophrenia. Recent theories of psychosis posit that aberrant encoding of prediction errors (PE) may underlie the expression of psychotic symptoms. This study used a roving mismatch negativity (MMN) paradigm to investigate whether the encoding of PE is affected by pharmacological manipulation of NMDAR or 5-HT2AR, and whether the encoding of PE under placebo can be used to predict drug-induced symptoms. Using a doubleblind within-subject placebo-controlled design, S-ketamine and psilocybin, respectively, were administrated to two groups of healthy subjects. Psychological alterations were assessed using a revised version of the Altered States of Consciousness (ASC-R) questionnaire. As an index of PE, we computed changes in MMN amplitudes as a function of the number of preceding standards (MMN memory trace effect) during a roving paradigm. S-ketamine, but not psilocybin, disrupted PE processing as expressed by a frontally disrupted MMN memory trace effect. Although both drugs produced positive-like symptoms, the extent of PE processing under placebo only correlated significantly with the severity of cognitive impairments induced by S-ketamine. Our results suggest that the NMDAR, but not the 5-HT2AR system, is implicated in PE processing during the MMN paradigm, and that aberrant PE signaling may contribute to the formation of cognitive impairments. The assessment of the MMN memory trace in schizophrenia may allow detecting early phases of the illness and might also serve to assess the efficacy of novel pharmacological treatments, in particular of cognitive impairments. Neuropsychopharmacology (2012) 37, 865-875;doi: 10.1038/npp.2011.261;published online 26 October 2011

关键词： model psychosis NMDAR 5-HT predictive coding MMN memory trace effect cognitive impairment

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