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31.
32.
An overview of nondestructive evaluation methods 总被引:1,自引:0,他引:1
Marvin Trimm 《Journal of Failure Analysis and Prevention》2003,3(3):17-31
ondestructive evaluation is described as nondestructive testing (NDT), nondestructive inspection (NDI), and nondestructive
examination (NDE). The activities associated with the evaluation include testing, inspection, and examination and primarily
involve looking at (or through) and/or measuring some characteristic of an object. Frequently there is a desire to determine
some characteristic of the object or to determine whether the object contains irregularities, discontinuities, or flaws. These
examinations, inspections, or tests are used to determine the physical soundness of a material without impairing its usefulness.
Nondestructive evaluation is a powerful tool that can help assure safety, quality, and reliability; increase productivity;
decrease liability; protect the environment; and save money. In this article, nondestructive evaluation is represented by
the acronym NDE. 相似文献
33.
The goal of this work is to provide a framework for applications to probabilistically meet latency targets using redundancy and multipath routing. It investigates the amount of redundancy necessary to maximize the probability of constructing a copy of a file F no later than a given delay bound Δ without any reservations. Redundancy is obtained from the information dispersal algorithm (IDA) of Rabin. Specifically, F is broken into b pieces, each of size s, and each piece is sent on one of the several (disjoint) paths from source to destination. Each piece contains some redundant information in such a way that any m≡|F|/s pieces are enough to reconstruct the file. This work presents both analytical and computational results to determine the optimal values of b and s to maximize the success probability. It also examines the impact of various parameters such as the file size, delay bound, loss rate, distance from the destination, on the probabilistic quality of service (QoS) guarantee. This is a novel approach to QoS routing since it does not require any reservations or extra overhead at intermediate nodes and effectively shifts the burden from nodes to links. 相似文献
34.
36 left-handed and 36 right-handed kindergarten children were asked to print after seeing a series of reversible letters and numbers presented individually on slides or flash cards. Regardless of handedness, both groups of Ss found the left–right orientation cues of the same letters and numbers difficult to recall. This challenges a proposal expressed in the "grammar of action" that claims that certain reversal errors in children's printing result from the inappropriate application of the horizontal motor rule, because although left- and right-handed children use this rule, they do so in different ways and therefore should have produced different errors. Another sample of 86 right-handed children from nursery school through Grade 1 was given the same printing task. Findings from this 2nd sample provide an additional challenge to the grammar of action by showing that reversals of the letter N, which are also thought to result from a misapplication of motor rules, decrease in frequency along with reversals of other letters and numbers, instead of increasing as predicted, during the developmental period when the motor rules that are said to be responsible for reversals of this particular letter become more strongly established. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
35.
JR Canvin AP Marvin M Sivakumaran JC Paton GJ Boulnois PW Andrew TJ Mitchell 《Canadian Metallurgical Quarterly》1995,172(1):119-123
Mice were infected intranasally with a serotype 2 pneumococcus, a pneumolysin-negative derivative (PLN-A), or an autolysin-negative derivative (AL-2). Numbers of wild type pneumococci were seen in the lung from approximately 12 h after infection and were first detected in the blood around this time. Immunofluorescent staining of lung sections showed that pneumolysin was produced in vivo. Pneumococcal infection resulted in alteration of the composition of the blood but not the bone marrow. Some of the hematologic changes did not occur after PLN-A. PLN-A had a slower growth rate in the lung and bacteremia was delayed. AL-2 was rapidly cleared from the lungs and was not detected in the blood. These events paralleled the pattern of histology in the lung, with the severity of inflammation reduced with PLN-A and no inflammation or hematologic changes with AL-2. 相似文献
36.
Reviews evidence concerning the congruence of the inductive and deductive models in logic and presents support for this congruence in the context of new test items designed to exemplify general-to-particular induction. Data from the Professional and Administrative Career Examination corroborate the logical foundations of deduction and induction as convergent models. Factor analysis of the items demonstrated factorial convergence, which lends additional support to the postulate of convergence. Implications for the understanding of cognitive processes and for psychometric practice are discussed in relation to such issues as the use of verbal and nonverbal test media, redundancy of measurement, and problem-solving strategies. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
37.
Eighteen sessions of cognitive–behavioral (CB) and 13 sessions of psychodynamic–interpersonal therapy obtained from experienced clinicians in a naturalistic setting were investigated to determine the various therapeutic interventions associated with high and low emotional experiencing (EXP). Clients receiving reflections and acknowledgments, affiliative and noncontrolling interventions, or interventions highlighting nonspecific client content were associated with maintained high EXP. Lengthier interventions and interventions rated as affiliative but moderately controlling were associated with shifts to low EXP. For clients of CB therapists, questions, interventions rated affiliative but controlling, and highlighting minimal emotional content were also associated with shifts to low EXP. Male therapists were associated with clients who maintained high EXP and female therapists were associated with clients who shifted to low EXP. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
Previous research has shown how spatial attention is guided to a target location, but little is understood about how attention is allocated to an event in time. The authors introduce a paradigm to manipulate the sequential structure of visual events independent of responses. They asked whether this temporal context could be implicitly learned and used to guide attention to a relative point in time or location, or both, in space. Experiments show that sequentially structured event durations, event identities, and spatiotemporal event sequences can guide attention to a point in time as well as to a target event's identity and location. Cuing was found to rely heavily on the element immediately preceding the target, although cuing from earlier items also was evident. Learning was implicit in all cases. These results show that the sequential structure of the visual world plays an important role in guiding visual attention to target events. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
39.
40.
A sensor for simultaneous electric and magnetic field measurement has been described by M. Kanda (see ibid., vol.EMC-26, no.3, p.102-10, 1984). It relies upon measuring the voltage across precisely matched loads at opposite sides of a loop antenna. A modification to the theory is presented to account for unmatched loading of the loop. Measured results of wave impedance over a 10-400-MHz range demonstrate the accuracy of the modified theory as well as highlighting a novel calibration technique 相似文献