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作者： Zahidi, Salman Linköping University

学位级别：master

information security has always been a topic of concern in the world as an emphasis on new techniques to secure the identity of a legitimate user is regarded as top priority. To counter such an issue, we have a traditional way of authentication factors “what you have” and “what you know” in the form of smart cards or passwords respectively. But biometrics is based on the factor “who are you” by analyzing human physical or behavioral characteristics. Biometrics has always been an efficient way of authorization and is now considered as a $1500 million industry where fingerprints dominate the biometrics while iris is quickly emerging as the most desirable form of biometric *** main goal of this thesis is to compare and evaluate different biometrics techniques in terms of their purpose, recognition mechanism, market value and their application areas. Since there are no defined evaluating criteria, my method of evaluation was based on a literature survey from internet, books, IEEE papers and technical surveys. Chapter 3 is focused on different biometrics techniques where I discuss them briefly but in chapter 4, I go deeper into Iris, fingerprints, facial techniques which are prominent in biometrics world. Lastly, I had a general assessment of the biometrics, their future growth and suggested specific techniques for different environment like access controls, e-commerce, national ids, and surveillance

关键词： Biometrics Evaluation information Security Engineering and Technology Electrical Engineering Electronic Engineering information Engineering Communication Systems Teknik och teknologier Elektroteknik och elektronik Kommunikationssystem teknik Technology Examensarbete i informationskodning information coding

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Study of high-bit-rate fibreoptic communication lines using the return-to-zero differential phase-shift keying (RZ DPSK) format for information coding

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QUANTUM ELECTRONICS 2007年第6期37卷 584-589页

作者： Shtyrina, O. V. Yakasov, A. V. Latkin, A. I. Turitsyn, S. K. Fedoruk, M. P. Russian Acad Sci Siberian Branch Inst Comp Technol Novosibirsk 630090 Russia Novosibirsk State Univ Novosibirsk 630090 Russia Russian Acad Sci Siberian Branch Inst Automat & Electrometry Novosibirsk 630090 Russia Aston Univ Birmingham B4 7ET W Midlands England

The results of mathematical simulation of propagation of optical signals in high-bit-rate dispersion-controlled fibreoptic communication lines are presented. information was coded by using the return-to-zero differential phase-shift keying (RZ DPSK) format to modulate an optical signal. A number of particular configurations of optical communication lines are optimised in terms of the bit error rate (BER). It is shown that the signal propagation range considerably increases compared to that in the case of a standard return-to-zero on-off keying (RZ OOK) format.

关键词： fibreoptic communication line information coding mathematical simulation

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A novel mode of neural information coding:Conductive coding

A novel mode of neural information coding:Conductive coding

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中国神经科学学会第四次会员代表大会暨第七届全国学术会议

作者： Zhi-Ru ZHU~(1,2),Xiao-Wei TANG~2,San-Jue HU~1 1 Institute of Neuroscience,the Fourth Military Medical University,Xi'an 710032 2 Center of Neural information Research Zhejiang University,Hangzhou 310027

The never fiber has been defined as a long neuronal process,which works as a relatively sample relay line between neurons,insuring the conduction of information from the cell body to the nerve *** large numbers of fibers,ramifications and synapses,neurons are not only connected with each other but also with their receptors,thus constituting a complex neural signal processing *** evidence for that pattern of interspike interval(ISI) series contains information is gaining attention as a new theoretical and experimental *** phenomena suggest that the pattern of ISI series is not always conducted faithfully along the *** the function of nerve fibers,especially non-myelinated fibers(C-fibers),need to *** present study is to be done with single C-fiber recording techniques in rabbits' saphenous *** main results are as following:(1) During continuous or train stimulations, various type of ISI patterns exhibit on the C-fibers.(2) Before the appearance of conductive failure,ISI series fluctuate obviously on the base of conduction velocity slowing.(3) The degree of variances of ISI series has close relationship with distance action potentials passed,indicating that the variances of ISI series accomplished on the course of propagating along nerve fiber.(4) hyperpolarization activated cation current(Ih) and 4-aminopyridine sensitive outward current(I4- AP) can modulate the patterns of ISI series.(5) The H-H neuron model was adopted to simulate the experimental results. These results suggest that a novel mode of neural information coding,our term for it is "conductive coding",appears in ISI series propagating along C-fibers.

关键词： information coding neural fibers firing patterns conduction

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A novel mode of neural information coding:Conductive coding

A novel mode of neural information coding:Conductive coding

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中国神经科学学会第四次会员代表大会暨第七届全国学术会议(The 7th Biennial Meeting and the 5th Congress of the Chinese Society for Neuroscience)

作者： Zhi-Ru ZHU Xiao-Wei TANG San-Jue HU Institute of Neuroscience the Fourth Military Medical University Xi'an 710032 Center of Neural I Center of Neural Information Research Zhejiang University Hangzhou 310027 Institute of Neuroscience the Fourth Military Medical University Xi'an 710032

关键词： information coding neural fibers firing patterns conduction

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Impact of DC Link Pulse coding on the Harmonic Distortion of the High-Frequency-Link Inverter

Impact of DC Link Pulse Coding on the Harmonic Distortion of...

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36th Annual Conference of the IEEE Industrial-Electronics-Society (IECON)/4th IEEE International Conference on E-Learning in Industrial Electronics/IES Industry Forum

作者： Mazumder, Sudip K. Rathore, Akshay K. Univ Illinois Dept Elect & Comp Engn Lab Energy & Switching Elect Syst Chicago IL 60607 USA

ISBN: (纸本)9781424452262

This paper presents the effects of information coding at the pulsating dc link on the performance of the high-frequency-link (HFL) inverter. The asymmetrical duty-cycle phase-shift modulation (resulting in pulse placement) of the front-end of the HFL inverter yields reduced frequency of the pulsating dc link voltage. It also results in reduced total harmonic distortion (THD) of the inverter output current and extended soft-switching range. Soft-switching and lower harmonic losses due to reduced THD yield higher inverter output (better source utilization) and higher efficiency. The enhanced performances are verified by the experiment results and comparisons.

关键词： DC link pulse coding asymmetrical duty-cycle phase-shift modulation harmonic distortion high-frequency-link inverter information coding invertors reduced total harmonic distortion switching circuits

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Designing a Constraint Based Parser for Sanskrit

Designing a Constraint Based Parser for Sanskrit

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4th International Sanskrit Computational Linguistics Symposium

作者： Kulkarni, Amba Pokar, Sheetal Shukl, Devanand Univ Hyderabad Dept Sanskrit Studies Hyderabad 500134 Andhra Pradesh India

ISBN: (纸本)9783642175275

Verbal understanding (sabdabodha) of any utterance requires the knowledge of how words in that utterance are related to each other. Such knowledge is usually available in the form of cognition of grammatical relations. Generative grammars describe how a language codes these relations. Thus the knowledge of what information various grammatical relations convey is available from the generation point of view and not the analysis point of view. In order to develop a parser based on any grammar one should then know precisely the semantic content of the grammatical relations expressed in a language string, the clues for extracting these relations and finally whether these relations are expressed explicitly or implicitly. Based on the design principles that emerge from this knowledge, we model the parser as finding a directed Tree, given a graph with nodes representing the words and edges representing the possible relations between them. Further, we also use the Mimamsa constraint of akanksa (expectancy) to rule out non-solutions and sannidhi (proximity) to prioritize the solutions. We have implemented a parser based on these principles and its performance was found to be satisfactory giving us a confidence to extend its functionality to handle the complex sentences(.1)

关键词： Sanskrit Constraint Based Parser information coding akanksa sannidhi

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Grammar Encoding in DNA-Like Secret Sharing Infrastructure

Grammar Encoding in DNA-Like Secret Sharing Infrastructure

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2nd International Conference on Advanced Science and Technology (AST)

作者： Ogiela, Marek R. Ogiela, Urszula AGH Univ Sci & Technol PL-30059 Krakow Poland

ISBN: (纸本)9783642135767

This publication presents a new technique for splitting secret information based on mathematical linguistics methods and allowing sequences of one or several bits to be coded in the way used in DNA cryptography. This solution represents a novel approach allowing DNA substitutions to be generalised and bit blocks of any length to be coded. Apart from extending the capability of coding in DNA cryptography, the technique presented will also make it possible to develop a new type of a hierarchical secret splitting scheme. Such schemes can be employed when developing new types of cryptographic protocols designed for the intelligent splitting and sharing of secrets.

关键词： DNA-cryptography secret sharing protocols mathematical linguistics information coding

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Spatio-temporal information coding in the cuneate nucleus

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NEUROCOMPUTING 2006年第16-18期69卷 1946-1953页

作者： Navarro, J. Sanchez, E. Canedo, A. Univ Santiago de Compostela Fac Fis Dept Elect & Ciencias Computac Grp Sistemas Intelixentes Santiago De Compostela 15782 Spain Univ Santiago de Compostela Dept Fisiol Fac Med Santiago De Compostela 15782 Spain

The dorsal column nuclei, cuneatus and gracilis, receive somesthetic information impinging on projection cells and local inhibitory interneurons. The presence of these interneurons allows spatio-temporal progressive coding of information that can be modeled [E. Sanchez, J. Aguilar, C. Rivadulla, A. Canedo, The role of Glycinergic Interneurons in the Dorsal Column Nuclei, Neurocomputing 58-60 (2004) 1049-1055 [14]] using their known synaptic connections with projection cells [J. Aguilar, C. Rivadulla, C. Soto, A. Canedo, New corticocuricate cellular mechanisms underlying the modulation of cutaneous ascending transmission in anesthetized cats, J. Neurophysiol. 89 (2003) 3328-3339 [1], J. Aguilar, C. Soto, C. Rivadulla, A. Canedo, The lemniscal-cuneate recurrent excitation is suppressed by strychnine and enhancedd by GABAA antagonists in the anesthetized cat, Eur. J. Neurosci. 16 (2002) 1697-1704 [2], J. Marino, L. Martinez, A. Canedo, Sensorimotor integration at the dorsal column nuclei, NIPS 14 (1999) 231-237 [9]. Here we explore the dependency of the processing time required to complete the progressive coding with regard to cutaneous stimuli varying in size and regularity of the intensity profile. (c) 2006 Elsevier B.V. All rights reserved.

关键词： dorsal column nuclei somatosensory system computational models information coding

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Effects of Dopamine Depletion on Network Entropy in the External Globus Pallidus

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JOURNAL OF NEUROPHYSIOLOGY 2009年第2期102卷 1092-1102页

作者： Cruz, Ana V. Mallet, Nicolas Magill, Peter J. Brown, Peter Averbeck, Bruno B. UCL Inst Neurol Sobell Dept Motor Neurosci & Movement Disorders London WC1N 3BG England Inst Gulbenkian Ciencias Oeiras Portugal Univ Oxford Med Res Council Anat Neuropharmacol Unit Oxford England

Cruz AV, Mallet N, Magill PJ, Brown P, Averbeck BB. Effects of dopamine depletion on network entropy in the external globus pallidus. J Neurophysiol 102: 1092-1102, 2009. First published June 17, 2009;doi: 10.1152/jn.00344.2009. Dopamine depletion in cortical-basal ganglia circuits in Parkinson's disease (PD) grossly disturbs movement and cognition. Classic models relate Parkinsonian dysfunction to changes in firing rates of basal ganglia neurons. However, disturbances in other dynamics of neural activity are also common. Taking both inappropriate firing rates and other dynamics into account and determining how changes in the properties of these neural circuits that occur during PD impact on information coding are thus imperative. Here, we examined in vivo network dynamics in the external globus pallidus (GPe) of rats before and after chronic dopamine depletion. Dopamine depletion led to decreases in the firing rates of GPe neurons and increases in synchronized network oscillations in the beta frequency (13-30 Hz) band. Using logistic regression models, we determined the combined and separate impacts of these factors on network entropy, a measure of the upper bound of information coding capacity. Importantly, changes in these features in dopamine-depleted rats led to a significant decrease in GPe network entropy. Changes in firing rates had the largest impact on entropy, with changes in synchrony also decreasing entropy at the network level. Changes in autocorrelations tended to offset these effects because autocorrelations decreased entropy more in the control animals. Thus it is possible that reduced information coding capacity within basal ganglia networks may contribute to the behavioral deficits accompanying PD.

关键词： entropy external globus pallidus Autocorrelation Network Basal Ganglia information coding network level Dopamine FIRING RATE

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Identification of the phase code in an EEG during gripping-force tasks: A possible alternative approach to the development of the brain-computer interfaces

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ARTIFICIAL INTELLIGENCE IN MEDICINE 2008年第1期44卷 41-49页

作者： Logar, Vito Skrjanc, Igor Belic, Ales Brezan, Simon Koritnik, Blaz Zidar, Janez Univ Ljubljana Fac Elect Engn LMSV & LAIP SI-1000 Ljubljana Slovenia Univ Med Ctr Ljubljana Inst Clin Neurophysiol SI-1525 Ljubljana Slovenia

Background: The subject of brain-computer interfaces (BCIs) represents a vast and still mainly undiscovered land, but perhaps the most interesting part of BCIs is trying to understand the information exchange and coding in the brain itself. According to some recent reports, the phase characteristics of the signals play an important rote in the information transfer and coding. The mechanism of phase shifts, regarding the information processing, is also known as the phase coding of information. Objective: The authors would like to show that etectroencephalographic (EEG) signals, measured during the performance of different gripping-force control tasks, carry enough information for the successful prediction of the gripping force, as applied by the subjects, when using a methodology based on the phase demodulation of EEG data. Since the presented methodology is non-invasive it could be used as an alternative approach for the development of BCIs. Materials and methods: In order to predict the gripping force from the EEG signals we used a methodology that uses subsequent signal processing methods: simplistic filtering methods, for extracting the appropriate brain rhythm;principal component analysis, for achieving the linear independence and detecting the source of the signal;and the phase-demodulation method, for extracting the phase-coded information about the gripping force. A fuzzy inference system is then used to predict the gripping force from the processed EEG data. Results: The proposed methodology has clearly demonstrated that EEG signals carry enough information for a successful prediction of the subject's performance. Moreover, a cross-validation showed that information about the gripping force is encoded in a very similar way between the subjects tested. As for the development of BCIs, considering the computational time to pre-process the data and train the fuzzy model, a real-time online analysis would be possible if the real-time non-causal limitations of the

关键词： Brain-computer interface Electroencephalography Fuzzy logic Gripping force information coding Phase demodulation Principal component analysis

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