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Search Results: 1 - 10 of 24 matches for " Daut DavidG "
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Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm
Liu Weiliang,Daut DavidG
EURASIP Journal on Image and Video Processing , 2007,
Abstract: A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs) of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.
Issues and Problems in Brain Magnetic Resonance Imaging: An Overview
Novanto Yudistira,Daut Daman
TELKOMNIKA , 2008,
Abstract: There are many issues and problems in the brain magnetic resonance imaging (MRI) area that haven’t solved or reached satisfying result yet. This paper presents an overview of the various issues and problems of the segmentation, correction, optimization, description and their application in MRI. The overview is started by describing the segmentation properties that are the most important and challenging in MRI brain manipulation. Then correction for reconstructing the brain MRI cortex, classification is utilized to classify the segmented brain image, and also review the uses of description is the great prospecting issue while some neurologist need the information resulted from brain imaging process including their potential problems from application applied by each technique. In each case, it is provided some general background information.
Progressive Image Transmission Based on Joint Source-Channel Decoding Using Adaptive Sum-Product Algorithm
Weiliang Liu,David G. Daut
EURASIP Journal on Image and Video Processing , 2007, DOI: 10.1155/2007/69805
Abstract: A joint source-channel decoding method is designed to accelerate the iterative log-domain sum-product decoding procedure of LDPC codes as well as to improve the reconstructed image quality. Error resilience modes are used in the JPEG2000 source codec making it possible to provide useful source decoded information to the channel decoder. After each iteration, a tentative decoding is made and the channel decoded bits are then sent to the JPEG2000 decoder. The positions of bits belonging to error-free coding passes are then fed back to the channel decoder. The log-likelihood ratios (LLRs) of these bits are then modified by a weighting factor for the next iteration. By observing the statistics of the decoding procedure, the weighting factor is designed as a function of the channel condition. Results show that the proposed joint decoding methods can greatly reduce the number of iterations, and thereby reduce the decoding delay considerably. At the same time, this method always outperforms the nonsource controlled decoding method by up to 3 dB in terms of PSNR.
攻击的社会性认知学习的调节
davidg.perry,louisec.perry,paulrasmussen
心里发展与教育 , 1987,
Abstract: 这项研究探索了小学儿童的攻击与影响儿童是否采取攻击行为的社会认知的两个等级的联系.给攻击性和非攻击性的儿童(平均年龄为11.3岁)提供二个调查表,让他们进行回答.一个调查表是测量儿童对自己进行攻击的能力及相应的行为的认识(即自我实力的认识),而另一个调查表则测量儿童对攻击性行为会得到的奖励和惩罚的后果的认识.
Problems and prospects of travel industry in Abkhazia
Daut V. Adzhba,Zaur I. Shalashaa
European Researcher , 2011,
Abstract: The article examines tourism as one of prior directions of Abkhazia national economy, which is determined by enormous natural resources and rich cultural and historic potential for different kinds of tourism development.
Franchise as a Way to Organize Travel Industry in Abkhazia
Daut V. Adzhba,Sergey A. Bagretsev
European Researcher , 2012,
Abstract: The contribution states the franchise system importance amid the financial crisis, which can be regarded as one of the ways to overcome crisis situations and develop tourism industry in Abkhazia.
Relationships between Harmonic Characteristics and Different Types of Voltage Source
Risnidar Chan,I. Daut,Syafruddin H,Yusniati Yusniati
TELKOMNIKA : Indonesian Journal of Electrical Engineering , 2012, DOI: 10.11591/telkomnika.v10i2.674
Abstract: This paper discusses about harmonic characteristics due to different types of voltage sources. Usually, the voltage source is sinusoidal. But in actual condition the load that receive voltage sources through the elements where the output voltage of element as input to the load is not pure sinusoidal, for example voltage source at (PCC) between transformer and linear load and nonlinear load. This research has been done with Schhafner Power Quality Analyzer and PM300 Power Quality Analyzer, was focused to all harmonic characteristics as power, voltage, current, power factor (p.f.), Harmonic Distortion, and harmonic energy losses cost. The load is Induction Motor with Adjustable Speed Drive (ASD) because the Induction Motor with Adjustable Speed Drive (ASD) is one of electronic device causes harmonics. The voltage sources in this research are sine wave, square wave and harmonic order combinations of 3rd, 5th and 7th which can create from Schhafner Power Quality Analyzer.
Gouraud Shading to Improve Appearance of Neuronal Morphology Visualization
Norhasana Razzali, Mohd Shafry Mohd Rahim, Rosely Kumoi, Daut Daman
International Journal of Biometric and Bioinformatics , 2010,
Abstract: This study is focused on Gouraud Shading’s approach to improve appearance ofneuron visualization. Neuron visualization is a computational tool that is able todescribe, generate, store and render large set of three-dimensional neuronalmorphology in a format that is compact, quantitative, and readily accessible tothe neuroscientists. This tool enlightens its ability as a powerful computationalmodeling of neuronal morphology to explore greater understanding in neurondevelopmental processes and structure-function relationships. However, after athorough investigation, one of the problems discovered in neuron structureprediction is related to misleading in generating digitalized neuron raw datatoward realistic neuron morphology visualization. For that reason, manyapproaches have been proposed in previous studies in order to perform suchvisualization based on stochastic sampling data of morphological measures fromdigital reconstructions of real neuron cells. Therefore, comparison among theseapproaches has been conducted to recognize a suitable approach. It is still at apreliminary stage in research development. This exercise reveals a constraint to reconstruct neuron model towards greater realism efficiently is still remains as anessential challenge in biological computing and visualization to provide a broadappearance of neuron knowledge distribution. As a result, the areas ofcomparative neuron analysis can be aided through presenting the knowledge ofrealism virtual neuron morphology. As a proposal, Gouraud Shading’s approachis applied for this purpose. Gouraud Shading is a visualization shading techniqueto perform a smooth lighting on the polygon surface without heavy computationalrequirement in calculating lighting for each pixel but at vertices only. Theconclusion is summarized based on verification exercise between ourframework’s results with existing results from three neuron visualizationapplications. The comparison analysis is done in term of reliability andsmoothness of surface neuron presentation. Roughly the proposed frameworkachieved the objective to solve the problem encountered in presenting virtualneuron data.
System-Level Impact of Multi-User Diversity in SISO and MIMO-based Cellular Systems
Rahul N. Pupala,Larry J. Greenstein,David G. Daut
Journal of Communications , 2011, DOI: 10.4304/jcm.6.4.274-284
Abstract: We quantify cell-wide mean throughputs of single-input-single-output (SISO) and multiple-input-multiple-output (MIMO)-based cellular systems which employ multi-user diversity (MuD). Our study considers several practical and useful system-level design dimensions, including: number of transmit/receive antennas; antenna-pattern (omni-directional or sectorized); degree of error-protection (Shannon coding, no coding or intermediate coding strategies); allowable constellation size; Rician $kappa$-factor; number of users and schedluling algorithm (Greedy (i.e. MAX C/I), Proportional Fair, or Equal Grade of Service) in single-cell (noise-limited) and multi-cell (co-channel-interference-limited) environments. We also provide a comparison between single-user systems having excess receive antennas and multi-user diversity systems with no excess receive antennas. Both strategies improve signal quality. Since economic costs of RF chains, mobile size and form factor limit the number of antennas a mobile receiver can have, multi-user diversity can be a more practical option. We observe that MuD with only a few scheduled users leads to comparable throughputs as receivers with excess receive antennas. By quantifying the average throughput gains that accrue from using multi-user SISO and MIMO-based cellular systems, this study serves the needs of operators to assess these promising technologies.
Influence of Harmonics in Laboratory due to Nonlinear Loads
Risnidar Chan,Ismail Daut,Syafruddin Hasan,Norhaidar Hasim
International Journal of Power Electronics and Drive Systems , 2012, DOI: 10.11591/ijpeds.v2i2.142
Abstract: This research was focused on the customer’s side of the meter which is the effect of harmonics on a laboratory in Electrical System Engineering School at K.Wai Perlis. Harmonic currents in equipments can cause them to experience overheating and increased losses, while harmonic voltage produces magnetic fields rotating at a speed corresponding to the harmonic frequency. This also results in equipments heating, mechanical vibrations and noise, reduced efficiency, reduced life, and voltage stress on insulation of equipment windings. The loads in this research are computers, Compact Fluorescent Lamps CFLs), Air Conditions and printers,which all of the loads are harmonic significant The instrument to measure and monitoring is Fluke 435 Power Quality Analyzer. With the operation of varying nonlinear loads, the injected harmonic current magnitudes and phase angles vary in a random way. This research offers the advantage of providing the utility a wealth of information on the effects of harmonics in their equipments. This will subsequently make them aware of the causes of increased cost and reduced efficiency that may be experienced by using these equipments. This paper describes the investigation cost of harmonic effect as THD, and harmonic energy losses cost. Keywords: harmonics, nonlinear loads, Energy losses cost, THD.
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