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This article presents a graph-theoretic method for constructing low-density parity-check (LDPC) codes from connected graphs without the requirement of large girth. This method is based on finding a set of paths in a connected graph, which satisfies the constraint that any two paths in the set are either disjoint or cross each other at one and only one vertex. Two trellis-based algorithms for finding these paths are devised. Good LDPC codes of practical lengths are constructed and they perform well with iterative decoding. 相似文献
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New literature results on the liquid equilibria in the three edge binary systems make necessary a reconsideration and correction of liquidus surfaces of the γ and δ solid solutions hitherto outlined in the literature. Therefore, with respect to the critically reinterpreted edge binary systems, the shape of the stable liquidus surface of the γ and δ solid solutions has been newly outlined. 相似文献
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Muzammil Ali Tariq Mahmud Peter John Heggs Mojtaba Ghadiri Dusan Djurdjevic Hossein Ahmadian Luis Martin de Juan Carlos Amador Andrew Bayly 《Chemical Engineering Research and Design》2014
A one-dimensional numerical model for a detergent slurry drying process in a counter-current spray drying tower is developed for the prediction of the gas and droplet/particle temperature profiles within the tower. The model accommodates droplets/particles over a range of sizes. A semi-empirical slurry droplet drying model is integrated with a counter-current tower simulation based on mass, energy and particulate phase momentum balances in order to calculate the drying rate and the particle residence time within the tower. The coupled first order ordinary differential equations for the two phases are solved numerically using the iterative shooting method in an algorithm developed within MATLAB. The predictions of the numerical model are compared with industrial pilot plant data. The results are found to vary significantly with the specified size distribution of the droplets. Despite the simplicity of the model in ignoring the coalescence, agglomeration, wall deposition and re-entrainment, the model gives reasonable agreement with the experimental data. 相似文献
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Near-Shannon-limit quasi-cyclic low-density parity-check codes 总被引:2,自引:0,他引:2
This letter presents two classes of quasi-cyclic low-density parity-check codes that perform close to the Shannon limit. 相似文献
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Djurdjevic D.Z. Benson T.M. Sewell P. Vukovic A. 《Lightwave Technology, Journal of》2004,22(10):2333-2340
The structure-related (SR) finite-difference beam-propagation method is applied to integrated optical couplers employing curved waveguide sections. A general nonorthogonal coordinate system is introduced that matches the local structure geometry, yielding a more accurate analysis with coarser meshes than standard schemes, thus providing significant computational resource savings. Furthermore, the algorithm is easily interfaced with conventional schemes. Examples of curved two-dimensional and three-dimensional directional waveguide couplers are examined to show the advantages and generality of SR schemes as well as to explore the role of the extra degrees of freedom offered by nonorthogonal meshing. 相似文献
6.
Andrija R. Ciric Nevena Ivanovic Milica S. Cvijovic Milena Jelikic-Stankov Ljubinka Joksovic Predrag T. Djurdjevic 《Food Analytical Methods》2014,7(7):1387-1399
In the present work, the rapid RP-HPLC method with UV (DAD) detection for simultaneous quantification of bioflavonoids: quercetin, apigenin, catechin, epicatechin, kaempferol, and luteolin in Brassica oleracea species samples (cauliflower, broccoli, and Brussels sprouts) was developed with the aid of LC-Simulator (ACD Labs® suite) software. A series of extracts obtained with different extraction method were evaluated for antioxidant activity. The optimal conditions for separation and quantification were established after nine scouting runs entered to LC-Simulator software. The optimized separation was achieved on Hypersil GOLD aQ column with isocratic elution and mobile phase composition A:2 % acetic acid in water and B:acetonitrile in 91:9 (v/v %) ratio. The R s values were in the range from 2.6 to 8.00, indicating good selectivity of the method. The obtained results generally show good agreement with published data. Low detection limits (0.02–0.055 μg/mL) were obtained with acceptable recoveries (90–109 %). Total time of analysis was less than 11 min; therefore, the proposed method represents significant improvement over existing methods. Extracts from Brassica vegetables, obtained using different extraction procedures, were studied for their radical scavenging effects. Scavenging of DPPH showed different kinetics at the beginning of the assay period and after 15 min from the initialization of reaction. Different kinetics suggested the presence of polymerized and/or less active antioxidants with different scavenging mechanisms for particular polyphenolic compounds. 相似文献
7.
Johnson Russell E.; Rosen Christopher C.; Djurdjevic Emilija 《Canadian Metallurgical Quarterly》2011,96(4):744
Researchers are often concerned with common method variance (CMV) in cases where it is believed to bias relationships of predictors with criteria. However, CMV may also bias relationships within sets of predictors; this is cause for concern, given the rising popularity of higher order multidimensional constructs. The authors examined the extent to which CMV inflates interrelationships among indicators of higher order constructs and the relationships of those constructs with criteria. To do so, they examined core self-evaluation, a higher order construct comprising self-esteem, generalized self-efficacy, emotional stability, and locus of control. Across 2 studies, the authors systematically applied statistical (Study 1) and procedural (Study 2) CMV remedies to core self-evaluation data collected from multiple samples. Results revealed that the nature of the higher order construct and its relationship with job satisfaction were altered when the CMV remedies were applied. Implications of these findings for higher order constructs are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
8.
Toxic effects due to high aluminum body loads were observed in a number of conditions following ingestion of Al-containing antacids. Bio-availability of aluminum depends not only on the solubility of the ingested salt but also on the physico-chemical properties of the soluble Al complexes formed in body fluids. Amino acids may, upon interaction with Al-salts, form absorbable Al-complexes. Hence, complex formation equilibria between Al(3+) and either, L- histidine or L-tyrosine were studied by glass electrode potentiometric (0.1 mol/L LiCl ionic medium, 298 K), proton NMR and uv spectrophotometric measurements. Non linear least squares treatment of the potentiometric data indicates that in the concentration ranges: 0.5=C(A1)=2.0 ; 1.0=C(His)=10.0; 2.5=PH=6.5, in Al(3+) + His solutions, the following complexes (with log overall stability constants given in parenthesis) are formed: Al(HHis)(3+)(12.21+/-0.08); Al(His)(2+), (7.25+/-0.08); and Al(HHis)His(2+), (20.3+/-0.1). In Al(3+) + Tyr solutions in the concentration range 1.0=C(Tyr)=3.0 mmol/L and ligand to metal concentration ratio from 2:1 to 3:1, in the pH interval from 3.0 to 6.5 the formation of the following complexes was detected: Al(HTyr)(2+), (12.72+/-0.09); Al(Tyr)(2+), (10.16+/-0.03) and Al(OH)(2)Tyr , (2.70+/-0.05). Proton NMR data indicate that in Al(His)(2+) complex histidine acts as a monodentate ligand but its bidentate coordination is possible with carboxylate oxygen and imidazole 1-nitrogen as donors. In Al(HTyr)(3+) complex tyrosine is a monodentate ligand with carboxylate oxygen as donor. The mechanism of the formation of complexes in solution is discussed as well as their possible role in aluminum toxicity. 相似文献
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Isothermal holding tests were carried out in the Fe-Ni-Mo system in the two-phase region between the liquidus (melt) and the solidus (crystal). The δ and γ liquidus surfaces in the iron-rich corner of the Fe-Ni-Fe3Mo2-NiMo subsystem, as well as the position of the peritectic line situated between them, could be very accurately established by the experimentally determined isotherms. Based on these results and on the known liquidus lines in the three boundary binary systems, as well as on the known concentration fields of the Fe3Mo2-NiMo solid solutions, the melting equilibria could be developed with sufficient accuracy in the entire subsystem. 相似文献