Associative memory design using overlapping decompositions

Cataloged from PDF version of article.This paper discusses the use of decomposition techniques in the design of associative memories via arti"cial neural networks. In particular, a disjoint decomposition which allows an independent design of lower-dimensional subnetworks and an overlapping decomposition which allows subnetworks to share common parts, are analyzed. It is shown by a simple example that overlapping decompositions may help in certain cases where design by disjoint decompositions fails. With this motivation, an algorithm is provided to synthesize neural networks using the concept of overlapping decompositions. Applications of the proposed design procedure to a benchmark example from the literature and to a pattern recognition problem indicate that it may improve the e!ectiveness of the existing methods. ( 2001 Published by Elsevier Science Ltd

MPLS Automatic Bandwidth Allocation via Adaptive Hysteresis

Cataloged from PDF version of article.MPLS automatic bandwidth allocation (or provisioning) refers to the process of dynamically updating the bandwidth allocation of a label switched path on the basis of actual aggregate traffic demand on this path. Since bandwidth updates require signaling, it is common to limit the rate of updates to reduce signaling costs. In this article, we propose a model-free asynchronous adaptive hysteresis algorithm for MPLS automatic bandwidth allocation under bandwidth update rate constraints. We validate the effectiveness of the proposed approach by comparing it against existing schemes in (i) voice and (ii) data traffic scenarios. The proposed method can also be used in more general GMPLS networks. (C) 2010 Elsevier B.V. All rights reserved

State Aggregation-based Model of Asynchronous Multi-Fiber Optical Switching with Shared Wavelength Converters

Cataloged from PDF version of article.This paper proposes new analytical models to study optical packet switching architectures with multi-fiber interfaces and shared wavelength converters. The multi-fiber extension of the recently proposed Shared-Per-Input-Wavelength (SPIW) scheme is compared against the multi-fiber Shared-Per-Node (SPN) scheme in terms of cost and performance for asynchronous traffic. In addition to using Markov chains and fixed-point iterations for modeling the mono-fiber case, a novel state aggregation technique is proposed to evaluate the packet loss in asynchronous multi-fiber scenario. The accuracy of the performance models is validated by comparison with simulations in a wide variety of scenarios with both balanced and imbalanced input traffic. The proposed analytical models are shown to remarkably capture the actual system behavior in all scenarios we tested. The adoption of multi-fiber interfaces is shown to achieve remarkable savings in the number of wavelength converters employed and their range. In addition, the SPIW solution allows to save, in particular conditions, a significant number of optical gates compared to the SPN solution. Indeed, SPIW allows, if properly dimensioned, potential complexity and cost reduction compared to SPN, while providing similar performance. (C) 2013 Elsevier B.V. All rights reserved

Shared-per-wavelength asynchronous optical packet switching: A comparative analysis

Cataloged from PDF version of article.This paper compares four different architectures for sharing wavelength converters in asynchronous optical packet switches with variable-length packets. The first two architectures are the well-known shared-per-node (SPN) and shared-per-link (SPL) architectures, while the other two are the shared-per-input-wavelength (SPIW) architecture, recently proposed as an optical switch architecture in synchronous context only, which is extended here to the asynchronous scenario, and an original scheme called shared-per-output-wavelength (SPOW) architecture that we propose in the current article. We introduce novel analytical models to evaluate packet loss probabilities for SPIW and SPOW architectures in asynchronous context based on Markov chains and fixed-point iterations for the particular scenario of Poisson input traffic and exponentially distributed packet lengths. The models also account for unbalanced traffic whose impact is thoroughly studied. These models are validated by comparison with simulations which demonstrate that they are remarkably accurate. In terms of performance, the SPOW scheme provides blocking performance very close to the SPN scheme while maintaining almost the same complexity of the space switch, and employing less expensive wavelength converters. On the other hand, the SPIW scheme allows less complexity in terms of number of optical gates required, while it substantially outperforms the widely accepted SPL scheme. The authors therefore believe that the SPIW and SPOW schemes are promising alternatives to the conventional SPN and SPL schemes for the implementation of next-generation optical packet switching systems. 2010 Elsevier B.V. All rights reserved

Effect of nebulized formoterol, ipratropium bromide, and furosemide in combination with fluticasone propionate on arterial blood gases of premature calves with respiratory distress syndrome

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe purpose of this study was to assess the clinical effect of nebulized formoterol (FM), ipratropium bromide (IB) and furosemide (FS) combined with fluticasone propionate (FP) on l ung function in premature calves with Respiratory Distress Syndrome (RDS). Thirty-six premature calves with RDS were randomly assigned to six different treatment groups (D1 to D6). All groups received the standard treatment, including oxygen and support treatment. Calves in D1 received only the standard treatment. The following combinations of nebulized drugs were used for the other groups: D2: FP, D3: FP+FM; D4: FP+IB; D5: FP+FS and D6: FP+IB+FM+FS. The treatment period (72 h) involved the application of FM (15 μg totally/12 h), IB (2 μg/kg/12 h), FS (1 mg/kg/12 h) and FP (15 μg/kg/12 h) for five minutes. A significant increase over time in blood pH, partial pressure of oxygen (PaO2), oxygen saturation (SatO2) and a decrease in partial pressure of carbon dioxide (PaCO2) and lactate were detected in all groups that received nebulized treatment; while in the D1, a significant change was observed only for PaCO2. Calves in D6 had the highest PaO2 and lowest PaCO2 values amongst all groups at the end of treatment. No statistical difference was observed between the Nebulization Groups (NG). Nebulized FM, IB and FS with FP combination in premature calves with RDS, in addition to the standard treatment showed a significant curative effect on lung function

Thrombotic gene polymorphisms and postoperative outcome after coronary artery bypass graft surgery

<p>Abstract</p> <p>Background</p> <p>Emerging perioperative genomics may influence the direction of risk assessment and surgical strategies in cardiac surgery. The aim of this study was to investigate whether single nucleotide polymorphisms (SNP) affect the clinical presentation and predispose to increased risk for postoperative adverse events in patients undergoing coronary artery bypass grafting surgery (CABG).</p> <p>Methods</p> <p>A total of 220 patients undergoing first-time CABG between January 2005 and May 2008 were screened for factor V gene G1691A (FVL), prothrombin/factor II G20210A (PT G20210A), angiotensin I-converting enzyme insertion/deletion (ACE-ins/del) polymorphisms by PCR and Real Time PCR. End points were defined as death, myocardial infarction, stroke, postoperative bleeding, respiratory and renal insufficiency and event-free survival. Patients were compared to assess for any independent association between genotypes for thrombosis and postoperative phenotypes.</p> <p>Results</p> <p>Among 220 patients, the prevalence of the heterozygous FVL mutation was 10.9% (n = 24), and 3.6% (n = 8) were heterozygous carriers of the PT G20210A mutation. Genotype distribution of ACE-ins/del was 16.6%, 51.9%, and 31.5% in genotypes I/I, I/D, and D/D, respectively. FVL and PT G20210A mutations were associated with higher prevalence of totally occluded coronary arteries (p < 0.001). Furthermore the risk of left ventricular aneurysm formation was significantly higher in FVL heterozygote group compared to FVL G1691G (<it>p </it>= 0.002). ACE D/D genotype was associated with hypertension (<it>p </it>= 0.004), peripheral vascular disease (p = 0.006), and previous myocardial infarction (<it>p </it>= 0.007).</p> <p>Conclusions</p> <p>FVL and PT G20210A genotypes had a higher prevalence of totally occluded vessels potentially as a result of atherothrombotic events. However, none of the genotypes investigated were independently associated with mortality.</p

Sustainable use of winter Durum wheat landraces under Mediterranean conditions

This research expected to determine new durum wheat germplasm resistant to biotic and abiotic stress factors. Eighty durum wheat lines selected from eighteen diverse landraces were tested together with eight durum wheat cultivars under reliable yellow rust epidemic during two successive years. Average infection coefficient of populations and cultivars was 32.44 in 2003 and 26.24 in 2004, showing severe epidemic condition which occurred at adult plant stage in 2003. Because of this the number of selected resistant and moderately resistant plant material greatly reduced. According to the yield trial study in which twenty resistant lines selected out of 30 resistant and moderately from sixteen populations were included, only two checks outperformed grand mean (2.48 t ha -1) and two lines selected from landrace population followed these with slightly lower yield difference. On the other hand, there were several lines which performed better than the grand mean of protein content (13.24%), SDS sedimentation (28.40 ml) and semolina color (24.35) and they ranked in the first group including the two checks cultivars. Bi- plot analysis showed that some promising lines with reasonable grain yields, good quality parameters, winter hardiness and drought tolerances among yellow rust resistance durum wheat landraces can be selected for semiarid conditions of Mediterranean countries for sustainable production