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41.
Aldri L. dos Santos Elias P. Duarte Jr. Glenn M. Keeni 《Journal of Network and Systems Management》2004,12(2):191-213
This paper presents a new clustering architecture for SNMP agents that supports semi-active replication of managed objects. A cluster of agents provides fault-tolerant object functionality: replicated managed objects of a crashed agent of a given cluster may be accessed through a peer cluster. The proposed architecture is structured in three layers. The lower layer corresponds to the managed objects at the network elements. The middle layer contains management entities called clusters that monitor and replicate managed objects. The upper layer allows the definition of management clusters as well as the relationship between clusters. A practical tool was implemented and is presented. The impact of replication on network performance is evaluated as well as a probabilistic analysis of replicated object consistency. 相似文献
42.
The performance of replica master and resolved motion rate control of a large manipulator is evaluated for two tasks. The first task simulates removing parts from a conveyor and stacking them on a pallet. The second task simulates stowing palletized cargo in a container.Related experiments are discussed and the results correlated to this work.Results show the bilateral master to have a distinct performance advantage over resolved motion rate control. The advantage is not as large as reported for small manipulators, however. 相似文献
43.
Walters Glenn D.; McGrath Robert E.; Knight Raymond A. 《Canadian Metallurgical Quarterly》2010,22(1):149
The taxometric method effectively distinguishes between dimensional (1-class) and taxonic (2-class) latent structure, but there is virtually no information on how it responds to polytomous (3-class) latent structure. A Monte Carlo analysis showed that the mean comparison curve fit index (CCFI; Ruscio, Haslam, & Ruscio, 2006) obtained with 3 taxometric procedures—mean above minus below a cut (MAMBAC), maximum covariance (MAXCOV), and latent mode factor analysis (L-Mode)—accurately identified 1-class (dimensional) and 2-class (taxonic) samples and produced taxonic results when applied to 3-class (polytomous) samples. From these results it is concluded that using the simulated data curve approach and averaging across procedures is an effective way of distinguishing between dimensional (1-class) and categorical (2 or more classes) latent structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
Gal Badishi Germano Caronni Idit Keidar Raphael Rom Glenn Scott 《Journal of Parallel and Distributed Computing》2009
Celeste is a robust peer-to-peer object store built on top of a distributed hash table (DHT). Celeste is a working system, developed by Sun Microsystems Laboratories. During the development of Celeste, we faced the challenge of complete object deletion, and moreover, of deleting “files” composed of several different objects. This important problem is not solved by merely deleting meta-data, as there are scenarios in which all file contents must be deleted, e.g., due to a court order. Complete file deletion in a realistic peer-to-peer storage system has not been previously dealt with due to the intricacy of the problem — the system may experience high churn rates, nodes may crash or have intermittent connectivity, and the overlay network may become partitioned at times. We present an algorithm that eventually deletes all file contents, data and meta-data, in the aforementioned complex scenarios. The algorithm is fully functional and has been successfully integrated into Celeste. 相似文献
45.
In order to develop a microbiological baseline of meat produced for domestic consumption in the state of New South Wales, chilled carcases were sampled from 16 abattoirs. Aerobic Plate Counts (APCs) and Escherichia coli counts were obtained from samples taken by sponging sites specified for each species in the Microbiological Guidelines to the Australian meat standard. On beef carcases the mean log10 APC/cm2 was 2.21 and E. coli was detected on 25% of carcases (mean log positives ?0.61/cm2). For sheep carcases corresponding values were 2.4, 53% and log10 -0.06/cm2, respectively. For pig carcases values were 2.81, 63% and log10 -0.23/cm2, respectively. For skin-off goat carcases values were 1.15, 27% and log10 -0.38/cm2, respectively. In the present survey, levels of indicator bacteria on carcases processed via the co-regulatory system operated in Australia were similar to those established in surveys of abattoirs that operate the traditional system overseen by government inspectors. 相似文献
46.
Electromagnetically assisted sheet metal stamping 总被引:3,自引:0,他引:3
A new approach, electromagnetically assisted sheet metal stamping, has been developed to alter strain distribution and improve formability in sheet metal stamping. In this study, this new approach was applied to form a non-symmetric panel from Al 6111-T4. The results show that this new approach greatly increased the draw depth of the formed panel, compared with conventional stamping. A detailed analysis of strain distribution, stretching and draw-in shows that both a more homogeneous strain distribution and enhanced draw-in contribute to producing deeper pans in a single press operation. This work demonstrates the feasibility of electromagnetically assisted sheet metal stamping, which offers a much improved ability to make complex components in a single press stroke as compared to conventional stamping. 相似文献
47.
Glenn Andrea L.; Raine Adrian; Schug Robert A.; Gao Yu; Granger Douglas A. 《Canadian Metallurgical Quarterly》2011,120(2):389
Only a few studies have examined hormones in psychopathy, and results have been mixed. It has been suggested that because hormone systems are highly interconnected, it may be important to examine multiple systems simultaneously to gain a clearer picture of how hormones work together to predispose for a certain construct. In the present study, we attempt to clarify the role of the hormones cortisol and testosterone in psychopathy by examining both hormones in a community sample of 178 adults demonstrating a wide range of psychopathy scores. Results showed that psychopathy scores were associated with an increased ratio of testosterone (baseline) to cortisol responsivity to a stressor. Psychopathy was not associated with either of these measures independently or with baseline cortisol levels. These findings suggest that these highly interconnected hormone systems may work in concert to predispose to psychopathy. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
48.
Walters Glenn D.; Wilson Nick J.; Glover Anthony J. J. 《Canadian Metallurgical Quarterly》2011,23(2):552
In two previous studies on general and violent recidivism (Walters & Heilbrun, 2010; Walters, Knight, Grann, & Dahle, 2008), the summed composite antisocial facet of the Psychopathy Checklist displayed incremental validity relative to the other 3 facets (interpersonal, affective, lifestyle), whereas the other 3 facets generally failed to demonstrate incremental validity relative to the antisocial facet. Because summed composite scores do not account for ordinal item distributions, the 6 Walters et al. (2008) samples were reanalyzed with factor score composites derived from a 4-factor confirmatory factor analysis. The results, however, showed little change from what had been obtained earlier with summed composite scores. Two additional samples not previously included in any incremental validity analyses of the Psychopathy Checklist evidenced a 3-factor structure, with the lifestyle and antisocial facets merged into a single factor. This single factor displayed incremental validity relative to the interpersonal and affective facets, but the reverse was not true regardless of whether summed composite scores or factor score composites were used. A comparison of zero-order correlations from all 8 samples revealed that the antisocial summed composite score predicted significantly better than the summed composite scores for the other 3 facets and that a superordinate factor failed to improve on the performance of either the antisocial summed composite score or the antisocial factor score composite. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
49.
Absence of sterol biosynthesis in oyster tissue culture 总被引:2,自引:0,他引:2
An oyster heart tissue culture was used to investigate the ability of the American oyster (Crassostrea virginica) to synthesize sterols from [14C]acetate. Lipids were extracted from cultured oyster heart cells and no label was found in the purified fatty acid fraction,
90% of which was located in the saturated and monounsaturated fractions. Although these results cannot rule out the possibility
of sterol synthesis in other oyster tissues, this and previous evidence are in support of the hypothesis that the American
oyster is unable to synthesize sterols. 相似文献
50.
Total sterols were analyzed from 28 species of Phytolaccaceae and from 29 species of closely related families—Basellaceae,
Portulaccaceae, Molluginaceae, and Stegnospermataceae. Eighteen of twenty-eight species of Phytolaccaceae contained dominant
Δ7-sterols while six species had dominant Δ5-sterols. Three species had dominant Δ0-sterols. Sterol composition strongly reflected taxonomic position. Nineteen of twenty-nine species from Basellaceae, Portulaccaceae,
Molluginaceae, and Stegnospermataceae contained dominant Δ7-sterols while ten species contained dominant Δ5-sterols. Until recently Δ7-sterols were considered rare in higher plants. It appears that a large number of species in the order Caryophyllales contain
primarily Δ7-sterols. 相似文献