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IEEE SSD International Multi-Conference on systems, signals and Devices

作者： A. Zoghlami M. Marzougui M. Atri R. Tourki Faculty of Sciences at Monastir Laboratory of Electronic and Microelectronic University of Monastir Monastir Tunisia

ISBN: (纸本)9781467364591

Due to their multiresolution signal decomposition, wavelet analysis has shown great success in the analysis of signals such as image processing and video coding. The recent progress in 3D spatio-temporal wavelet video coding led to the emergence of a new generation of scalable video schemes. In fact, much attention has been given to t+2D analysis where temporal redundancy is first exploited through a motion compensated multiresolution decomposition and the resulting temporal subband frames are then spatially decomposed with a wavelet transform. This paper presents a high-level implementation of a video coding chain based on MCTF temporal filtering and spatial block processing. In order to evaluate the overall system performance, a comparative study was conducted to choose the adequate block-matching algorithm during the temporal filtering steps. evaluation of the quality of the reconstructed frames based on the compression ratio was done with spatial analysis based on 5/3 and 9/7 wavelet. simulation results show that the proposed video coding has a notable performance in terms of compression ratio and quality, also some advantages provided by the choice of the temporal-filtering equation allow to reduce the computational complexity and reduce the amount of memory occupied during the video encoding/decoding process compared to classical temporal 5/3MCTF filtering.

关键词： PSNR Wavelet transforms Wavelet analysis image coding Video coding image reconstruction

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modeling effects of impulse noise on Application-Layer FEC in DSL channels

Modeling effects of impulse noise on Application-Layer FEC i...

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IEEE International Symposium on Broadband Multimedia systems and Broadcasting (BMSB)

作者： V. Pullano R. Skupin G.E. Corazza C. Hellge T. Schierl Department of Electrical Electronic and Information Engineering-Guglielmo Marconi University of Bologna Bologna Italy Multimedia Communications Group Image Processing Department Fraunhofer Heinrich Hertz Institute Berlin Germany Multimedia Communications Group Image Processing Department Fraunhofer HHI 10587 Berlin Germany

Internet Protocol Television (IPTV) services rely on the existing IP network infrastructure to deliver high quality video. In order to achieve reliable services, the nature of the underlying transmission channel has to be taken into account. Erasures on access networks such as present in Digital Subscriber Lines (DSL) have to be overcome. Impulse noise, e.g. Repetitive Electrical Impulse Noise (REIN), is one of the dominant error sources in the signal band of DSL channels and can be characterized as fixed-length error bursts. One countermeasure in IPTV system design to increase the robustness against impulse noise impairments is the implementation of Forward Error Correction on the Application-Layer (AL-FEC). In this paper a mathematical model is derived which describes the effect of the REIN channel on the performance of AL-FEC schemes. The effects on the application layer are modeled by a Markov chain with a memory proportional to the error burst length. Extensive empirical simulation campaigns, in the context of AL-FEC protected IPTV services, are used to prove the correctness of the proposed model and additionally, the runtime behavior of the model is analyzed.

关键词： Mathematical model Forward error correction Noise Decoding IPTV Runtime Accuracy

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Designing a new MANET′s Environment using Computer simulation

Designing a new MANET′s Environment using Computer Simulati...

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作者： Saad Talib Hasson University of Babylon

simulation plays an important role in the verification and implementation of the Mobile Ad-hoc Network (MANET) environments. It can be used to model any suggested environment. MANET was defined as a set of mobile nodes that moved freely and connected among each other without any infrastructure. simulation represents a tool that evaluates the performance of an existing or proposed MANET environment under different configurations of interest and over long periods of real time. In this paper the effects of the number of nodes, their speed and their pause time were modeled and analyzed. The network simulator NS-2 was used as a tool to study and evaluate the effects of these factors. Many performance metrics such as throughput, packets loss, packet delivery fraction (PDF), average end-to-end delay, normalize routing load (NRL) and jitter were used as comparison indications. The simulation environment was implemented with different number of nodes, different speeds, and varying pause times. A mathematical model was built and implemented firstly to analyze the effects of the number of nodes and their speed on the behavior of the suggested MANET environment. The second model was built and used to analyze the effects of the number of nodes and their pause times.

关键词： simulation, performance evaluation, MANET, mathematical modeling

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On optimality of teaching quality for a mathematical topic using Neural Networks (with a case study)

On optimality of teaching quality for a mathematical topic u...

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IEEE Education Engineering (EDUCON)

作者： Saeed A. Al-Ghamdi Hassan M. H. Mustafa Ayoub Al-Hamadi Mohammed H. Kortam AbdelAziz MAl-Bassiouni Electrical Engineering Department Al-Baha University Al-Baha Kingdom of Saudi Arabia Banha University Egypt Computer Engineering Department Al-Baha University Al-Baha Kingdom of Saudi Arabia Institute for Elecronics Signal Processing and Communications (IESK) Otto-von-Guericke-University Magdeburg Germany AISafa Modern Private Schools Safwa Eastern Province Kingdom of Saudi Arabia Telecommunication & Technology Company Cairo Egypt

This paper addresses an interdisciplinary approach integrating evaluation of an educational issue with Artificial Neural Network (ANN) modeling. Specifically, it is concerned with ANN modeling of two Computer Assisted Learning (CAL) packages/modules using various learning rate values. Both packages are considered for teaching a mathematical topic: “How to solve long division problem?”. They have been submitted at the fifth grade classroom level in elementary schools (as a case study with or without associated teacher's voice). Furthermore, after the application of the suggested CAL packages, practical findings have been compared with classical learning obtained results. Interestingly, all findings are shown to be in agreement with simulation results after running the introduced realistic ANN model. Finally, this work investigated well how measured mathematical teaching quality could be fairly improved via assessment of two learning parameters' performance (achievement level & response time).

关键词： Decision support systems Engineering education Conferences

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EeteS-The EnMAP End-to-End simulation Tool

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IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 2012年第2期5卷 522-530页

作者： Segl, Karl Guanter, Luis Rogass, Christian Kuester, Theres Roessner, Sigrid Kaufmann, Hermann Sang, Bernhard Mogulsky, Valery Hofer, Stefan Deutsch GeoForschungsZentrum GFZ Helmholtz Zentrum Potsdam Remote Sensing Sect D-14473 Potsdam Germany Univ Oxford Clarendon Lab Dept Atmospher Ocean & Planetary Phys Oxford OX1 3PU England Univ Oxford Atmospher Ocean & Planetary Phys Subdept Oxford England Kayser Threde GmbH D-81379 Munich Germany

The design of future Earth imaging systems, the optimization of fundamental instrument parameters, and the development and evaluation of data pre-processing and scientific-exploitation algorithms require an accurate end-to-end simulation of the entire image generation and processing chain. For this purpose, the end-to-end simulation software EeteS has been developed within the framework of the Environmental Mapping and Analysis Program (EnMAP) mission. This paper presents the EeteS simulation approach and software implementation focusing on calibration and pre-processing. The sequential processing chain of the EnMAP scene simulator consists of four independent parts-the atmospheric, spatial, spectral and radiometric modules. This forward simulator is coupled with a backward simulation branch consisting of calibration modules (non-linearity, dark current and absolute radiometric calibration) and a series of pre-processing modules (radiometric calibration, co-registration, atmospheric correction and orthorectification) forming the complete end-to-end simulation tool. In the result EeteS is capable of simulating EnMAP-like raw image scenes (L0) taking into account a variety of instrumental and environmental configurations. Furthermore, EeteS allows simulations of EnMAP reflectance images carrying out the complete L1 and L2 processing chains. Analysis of the intermediate and final EeteS simulation products has shown the accurate, reliable and consistent performance of the developed modules enabling the system to support technical decision-making processes required for the development of the EnMAP sensor. EeteS has also been used to estimate the SNR characteristics of potential EnMAP products after calibration and pre-processing. Comparing the results to SNR characteristics achieved by the already existing EO-1 Hyperion system has shown a significantly improved SNR which can be expected from future EnMAP data products.

关键词： End-to-end simulation EnMAP image pre-processing sensor calibration signal-to-noise ratio

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performance analysis of under-modelling stereophonic acoustic echo cancellation by adaptive filtering LMS algorithm

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COMPUTERS & ELECTRICAL ENGINEERING 2012年第6期38卷 1579-1594页

作者： Djendi, Mohamed Bounif, Aouda Univ Saad Dahleb Blida Signal Proc & Image Lab LATSI Blida 09000 Algeria

This paper addresses the field of stereophonic acoustic echo cancellation (SAEC) with adaptive filtering algorithms. In SAEC applications, using the least mean square (LMS) algorithm, it is usually assumed that the lengths of the adaptive filters are equal to that of the unidentified system responses. Although, in many realistic situations, under-modelled lengths adaptive filters, whose lengths are less than that of the unidentified systems (under-modelled systems), are employed, and analysis results for the exact modelled stereophonic LMS algorithm are not automatically appropriate to the under-modeled lengths. In this paper, we present a statistical analysis of the under-modeled stereophonic LMS algorithm. Exact expressions and deterministic recursive equations to the mean coefficients behavior of the adaptive LMS filters are derived to completely characterize and assess the performances (transient and steady-state) of the under-modeling stereophonic LMS algorithm. The expected theoretical behaviour is compared with Monte Carlo simulations and practical experimental results, showing a very good agreement. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： ADAPTIVE filters ECHO suppression (Telecommunication) performance evaluation MEAN square algorithms SYSTEM identification STATISTICS COMPUTER simulation COMPARATIVE studies

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Efficiency Enhancement of Sigma-Delta Modulator Based Transmitters Using Multi-Level Quantizers

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JOURNAL OF signal processing systems FOR signal image AND VIDEO TECHNOLOGY 2012年第2期69卷 125-132页

作者： Boulejfen, N. Elsayed, F. M. Helaoui, M. DeVocht, L. Ghannouchi, F. M. Univ Calgary Dept Elect & Comp Engn iRadio Lab Calgary AB T2N 1N4 Canada

This paper is concerned with the performance of first- and second- order sigma-delta modulator (Sigma Delta M) based transmitters with an Orthogonal Frequency Division Modulation (OFDM) signal and Code Division Multiplexing Access (CDMA) signal. In particular, the WorldWide Interoperability for Microwave Access (WiMAX) and Interim Standard 95 (IS-95) down link signals have been used for this study as test signals. The simulation and experimental results showed that the performances of the Sigma Delta M for both signals are improved by increasing the number of quantization levels and the order of the Sigma Delta M circuit. A Sigma Delta modulator based transmitter using a switching mode power amplifier was developed and built for validation purposes. It is found that the increase of the quantization level of the Sigma Delta modulator from 2 to 5 leads to a substantial improvement in the measured power efficiency of the transmitter from 5% to 42%. This improvement in efficiency is in good agreement with simulated and measured results obtained using simulink and FPGA board respectively.

关键词： CDMA FPGA IS-95 performance evaluation Power amplifier Sigma delta modulators WiMAX

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simulation of the performance and image Quality Characteristics of the Landsat OLI and TIRS Sensors Using DIRSIG

Simulation of the Performance and Image Quality Characterist...

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Conference on Sensors, systems and Next-Generation Satellites XVI

作者： Schott, John R. Gerace, Aaron Montanaro, Matthew Rochester Inst Technol 54 Lomb Mem Dr Rochester NY 14623 USA Sigma Space Corp NASA Goddard Space Flight Ctr Greenbelt MD 20771 USA

ISBN: (纸本)9780819492739

The Digital Imaging and Remote Sensing (DIRS) image Generation (DIRSIG) model has been significantly upgraded to support the Landsat Data Continuity Mission (LDCM). The DIRSIG improvements simulate the LDCM Thermal Infrared Sensor (TIRS) and the Operational Land imager (OLI) sensor's characteristics in support of the NASA and USGS image quality assessment programs. These improvements allow for simulation of spacecraft orbits using standard NORAD two line element (TLE) orbital descriptors. Sensor improvements include individual detector element lines of site, relative spectral response (RSR), bias, gain, non-linear response, and noise. Using DIRSIG's existing source-target-sensor radiative transfer, atmospheric propagation, scene simulation, and thermal models, simulated Landsat 8 imagery was generated. These tools were developed to enable assessment of design trades during instrument development and build, and evaluation of expected performance during instrument test, as test data is used to refine the modeled instrument performance. Current efforts are aimed at refining predicted performance models, simulating on-orbit calibration maneuvers and generation of data to test data processing and analysis algorithms. Initial studies are aimed at assessing the impact of RSR variation on banding and striping in both OLI and TIRS and the use of side slither (90 degrees Yaw) as a possible method to characterize and potentially compensate for non-linearity effects. Ongoing work aimed at simulating targets to support image based registration of the OLI and TIRS instruments is also presented. In general, the use of advanced simulation and modeling tools to support instrument design trades, image quality prediction, on-orbit image quality assessment and operational trades is reviewed. The overall effort is designed to provide simulated imagery incorporating all aspects of the instrument acquisition physics and scene phenomenology in support of instrument developers, operators, a

关键词： Landsat DIRSIG image Quality modeling TIRS OLI Calibration

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Measuring the performance of super-resolution reconstruction algorithms

Measuring the performance of super-resolution reconstruction...

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Conference on Infrared Imaging systems - Design, Analysis, modeling, and Testing XXIII

作者： Dijk, Judith Schutte, Klamer van Eekeren, Adam W. M. Bijl, Piet TNO NL-2509 JG The Hague Netherlands

ISBN: (纸本)9780819490339

For many military operations situational awareness is of great importance. This situational awareness and related tasks such as Target Acquisition can be acquired using cameras, of which the resolution is an important characteristic. Super resolution reconstruction algorithms can be used to improve the effective sensor resolution. In order to judge these algorithms and the conditions under which they operate best, performance evaluation methods are necessary. This evaluation, however, is not straightforward for several reasons. First of all, frequency-based evaluation techniques alone will not provide a correct answer, due to the fact that they are unable to discriminate between structure-related and noise-related effects. Secondly, most super-resolution packages perform additional image enhancement techniques such as noise reduction and edge enhancement. As these algorithms improve the results they cannot be evaluated separately. Thirdly, a single high-resolution ground truth is rarely available. Therefore, evaluation of the differences in high resolution between the estimated high resolution image and its ground truth is not that straightforward. Fourth, different artifacts can occur due to super-resolution reconstruction, which are not known on forehand and hence are difficult to evaluate. In this paper we present a set of new evaluation techniques to assess super-resolution reconstruction algorithms. Some of these evaluation techniques are derived from processing on dedicated (synthetic) imagery. Other evaluation techniques can be evaluated on both synthetic and natural images (real camera data). The result is a balanced set of evaluation algorithms that can be used to assess the performance of super-resolution reconstruction algorithms.

关键词： super-resolution recontruction signal-to-noise ratio MTF enhancements Nyquist frequency

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Computer simulation of Magnetic Resonance Angiography Imaging. Parallel Implementation in Heterogeneous Computing Environment

Computer Simulation of Magnetic Resonance Angiography Imagin...

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Joint Conference on New Trends in Audio and Video And signal processing - Algorithms, Architectures, Arrangements and Applications (NTAV/SPA)

作者： Klepaczko, Artur Szczypinski, Piotr Dwojakowski, Grzegorz Kocinski, Marek Strzelecki, Michal Lodz Univ Technol Inst Elect Ul Wolczanska 211-215 PL-90924 Lodz Poland

ISBN: (纸本)9788372835024

Magnetic resonance imaging (MRI) is currently widely used in medical image diagnosis. However, MR scanners are extensively used in clinics and thus are rarely accessible for experimentation. In consequence, the number of images available for image processing methods evaluation is too low and there appears a need for a method to generate synthetic images. In their previous works, the authors studied various methods for blood vessels segmentation and tracking. Effectiveness of the designed algorithms requires objective verification which implies repetition of experiments for large number of images and comparing the results with some ground truth models. Therefore, this study aims at designing a computer system which implements numerical routines for generation of synthetic MRA images. In particular, in this paper we study the performance of various configurations of assembled computer grid and analyze their potential in angiographic image synthesis.

关键词： Magnetic Resonance Angiography Computer simulation images image diagnosis image synthesis Computer systems experimentation computational grids ground truth Blood Vessels Repetition network computing environments distributed computing environment image processing method Magnetic Resonance Imaging

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