Vectorization and parallelization of a production reactor assembly code

In order to efficiently use new features of supercomputers, production codes, usually written 10 – 20 years ago, must be tailored for modern computer architectures. We have chosen to optimize the CPM-2 code, a production reactor assembly code based on the collision probability transport method. Substantional speedups in the execution times were obtained with the parallel/vector version of the CPM-2 code. In addition, we have developed a new transfer probability method, which removes some of the modelling limitations of the collision probability method encoded in the CPM-2 code, and can fully utilize parallel/vector architecture of a multiprocessor IBM 3090.     

Topological Editing of Cross-Relaxation Networks

We have used the elements of graph theory to describe NMR cross-relaxation networks in macromolecules and to analyze different experiments used for topological editing. We propose a new experiment, block decoupled NOESY (B.D. NOESY), that splits the cross-relaxation network of a macromolecular system into two noninteracting subdomains. Splitting is achieved by arranging for the effective z-components of the magnetization in one subdomain, as viewed from the other subdomain, to be zero. The B.D. NOESY experiment, in favorable cases, can usefully simplify the analysis of cross-relaxation spectra by removing certain ambiguities. We demonstrate the method by separating the aromatic resonances from the rest of the cross-relaxation network of a small globular protein: turkey ovomucoid third domain, M_r 6000. The resulting spectrum provides a clearer picture of cross-relaxation pathways that involve only aromatic or only aliphatic spins. By comparing the B.D. NOESY spectrum with the normal NOESY spectrum, we were able to identify cross peaks that contain contributions from indirect magnetization transfer (spin diffusion) mediated by the aromatic side chains. In the terminology of graph theory, these experiments decompose topological networks of cross-relaxation into two subgraphs, the join of which generates the original graph.     

Cost-optimized switched reluctance motor drive with bipolar currents

The manufacturing cost of switched reluctance motors (SRM) are low due to concentrated stator windings and extremely simple and robust rotor construction, having neither permanent magnets nor the rotor windings. Therefore, the SRM drives have been considered as a promising solution for cost-critical applications where the electronic speed control is needed, such as the appliance drives, HVAC blowers and compressors, drives in commercial and residential buildings and similar. One of the reasons that hindered the SRM drives expansion was the lack of standardized power converters produced in volume. Advantageous SRM power converter topologies have been proposed over the years, however, some of them were utilizing a large number of discrete power components, while the others were leading to a poor utilization of the DC-bus voltage. In this article, a novel SRM drive is proposed, entirely based on standard industrial inverter modules, fully utilizing bus voltage. Besides, due to the pulse polarity alteration, the dwell period can be arbitrarily chosen and can freely overlap defluxing interval in the adjacent phase. Therefore, the applicable voltage reaches theoretical maximum for the given bus voltage, extending in such way the torque-speed region up to the motor-related limits. Proposed topology is functional in the four quadrants and in the field weakening as well. This article includes the operation principles of the proposed solution and continues with practical application on a three-phase SRM. Also, design considerations and experimental results are included, as well as the consideration of the drive cost.     

Improving network security using genetic algorithm approach

With the expansion of Internet and its importance, the types and number of the attacks have also grown making intrusion detection an increasingly important technique. In this work we have realized a misuse detection system based on genetic algorithm (GA) approach. For evolving and testing new rules for intrusion detection the KDD99Cup training and testing dataset were used. To be able to process network data in real time, we have deployed principal component analysis (PCA) to extract the most important features of the data. In that way we were able to keep the high level of detection rates of attacks while speeding up the processing of the data.     

The effects of a new traffic safety law in the Republic of Serbia on driving under the influence of alcohol

The aim of the study presented here has been to see what the effects of the new traffic safety law are, 2 years into its initial implementation, on driving under the influence of alcohol. Until the end of 2009, the legal limit for blood concentration for drivers in Serbia was 0.5 g/l; however, the new traffic safety law stipulates the new limit to be 0.3 g/l. A retrospective autopsy study was performed over a 6-year period (from 2006 to 2011) whose sample covered cases of fatally injured drivers who had died at the scene of the incident, before being admitted to hospital. A total of 161 fatally injured drivers were examined for their blood alcohol concentration. The average age for these drivers was 40.2 ± 15.4 years, with a significant male predominance of 152 men to 9 women (χ² = 152.000, p < 0.001). This study has shown no decrease in the ratio of drivers under the influence of alcohol vs. all drivers (Pearson χ² = 4.415, df = 5, p = 0.491), nor in the number of drivers under the influence of alcohol (Pearson χ² = 6.629, df = 5, p = 0.250), nor a decrease in the mean blood alcohol concentration in drivers (1.72 ± 0.87 vs. 1.68 ± 0.95 g/l, t = 0.177, df = 80, p = 0.860). The conclusion of this study is that the new law has had a limited effect on driving under the influence of alcohol, which still remains one of the major human factors, responsible for road-traffic crashes in Serbia.     

An in-depth analysis of Raman and near-infrared chemical images of common pharmaceutical tablets

This study reports on the application of Raman and near-infrared (NIR) imaging techniques for determining the spatial distribution of all (five) components in a common type of pharmaceutical tablet manufactured in two different ways. Multivariate chemical images were produced as principal component (PC) scores, while univariate images were produced by using the most unique spectra selected by the orthogonal projection approach (OPA), a searching algorithm. Multivariate Raman images were obtained for all five components in both tablets, while only two or three components could be imaged with the NIR instrument. Very interesting PC results are reported that in effect cast doubt on the effectiveness of the established criteria for determining signal-related PCs in the Raman data. PCA has been found to be indispensable for imaging the minor components using the Raman data. Significant similarity between the multivariate and univariate chemical images has been noted despite there being considerable spectral overlap within the Raman and, especially, within the NIR mapping data sets. Gray-scale images are carefully thresholded, which allowed for quantitative comparison of the obtained binarized images. A thorough discussion is given on the problems and approximations needed for producing composite images.     

Influence of the type and degree of alteration of andesite and dacite on the quality and life of asphaltic concrete

This report deals with the influence of alteration processes in andesite and dacite with special reference to those alterations and characteristics of stone having the greatest influence on the quality of asphaltic concrete mixes. Using andesites and dacites with extremely different properties for standard asphaltic mixes has proved that quality of the mixes very much depends on the quality of the stone aggregate used. Properties of stone aggregate of different degree and type of alteration have a significant influence on the rheological characteristics of bitumen. Therefore, special attention has been paid to this influence.     

Blackberry seed extracts and isolated polyphenolic compounds showing protective effect on human lymphocytes DNA

The tentative identification of seed extracts from 3 cultivars of blackberry (blackberry seed extracts [BSEs]) constituents was performed by LC/UV/MS technique. The identified compounds belonged to ellagitannins, galic acid derivatives, and ellagic acid derivatives. Two ellagitannins, Lambertianin C and Sanguiniin H-6, and an ellagic acid derivative, 4-α-L-arabinofuranosylellagic acid, were isolated using semipreparative High-performance liquid chromatography. The structure elucidations were based on high resolution-mass spectrometry and nuclear magnetic resonance studies. The BSEs and 3 isolated pure compounds were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (MN) assay. The frequency of MN was scored in binucleated cells, and nuclear proliferation index was calculated. Among the tested extracts, the seeds of cv. Thornfree at concentration of 1 μg/mL exhibit the most prominent effect decreasing the frequency of MN by 62.4%, when compared with the controls cell cultures. Antioxidant potential of pure ellagitannins cannot explain the strong effect of BSEs. The assumption was that better antioxidant effect of BSEs result from synergistic effects of individual compounds contained in the extracts and/or some minor components possessed strong activity. PraCTICAL APPLICATION: Our results provide evidence of protective effects of BSEs and isolated pure compounds on cytogenetic damages in human lymphocytes. Thus, BSEs could exert beneficial effects in quite a few diseases, because many of the biological actions have been attributed to their antioxidant properties.