Random switching techniques for inverter control

New techniques which dramatically reduce acoustic noise by randomising the inverter switching frequency for inverter control are presented. It is shown that the proposed techniques combine the advantages of conventional pulsewidth modulation (PWM) techniques based on regular-sampling techniques and random PWM techniques     

Nuclear waste management in the US: The Nuclear Waste Technical Review Board's perspective

The US program for the management and disposal of commercial spent nuclear fuel and high level waste is in a period of potential programmatic, regulatory, and legislative change. Proposals currently being considered by the US Congress would authorize the development of a storage facility as soon as possible adjacent to the potential repository site at Yucca Mountain. The legislation also would establish regulatory requirements for a permanent repository at an individual dose limit of 1 mSv year⁻¹ (100 mrem year⁻¹) for the average person living near the repository. Concurrently, the fiscal year 1996 appropriation to characterize the Yucca Mountain site has been reduced by approximately 40%. These initiatives portend possible changes in the focus of the US program, including a fundamental shift in priority from permanent disposal to temporary storage, and a change in the approach to licensing a potential repository at the Yucca Mountain site. This paper provides the perspective of the members of the Nuclear Waste Technical Review Board on the impact these developments could have on the future of the US program. It discusses the Board's opinion on how to address the issues these and other developments raise in a way which moves the US civilian radioactive waste management program forward.     

Refinements in validity generalization methods: Implications for the situational specificity hypothesis.

Using a large database, this study examined 3 refinements of validity generalization procedures: (1) a more accurate procedure for correcting the residual standard deviation (SD) for range restriction to estimate SDp, (2) use of r? instead of study-observed rs in the formula for sampling error variance, and (3) removal of non-Pearson rs. The 1st procedure does not affect the amount of variance accounted for by artifacts. The addition of the 2nd and 3rd procedures increased the mean percentage of validity variance accounted for by artifacts from 70 to 82%, a 17% increase. The cumulative addition of all 3 procedures decreased the mean SDp estimate from .150 to .106, a 29% decrease. Six additional variance-producing artifacts were identified that could not be corrected for. In light of these it was concluded that the obtained estimates of mean SDp and mean validity variance accounted for were consistent with the hypothesis that the true mean SDp value is close to zero. These findings provide further evidence against the situational specificity hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming after severe closed head trauma: Automatic and attentional processes.

The 2-process theory of semantic priming (J. H. Neely, 1977; M. I. Posner and C. R. Snyder, 1975) was used to determine the maintenance of automatic processes after severe closed head injury (CHI) and to determine whether processes that demand attention suffer a deficit. Ss with severe CHI (N?=?18,?>?2 yrs postinjury) and 18 matched control Ss completed a lexical decision task in which a category prime was followed by a target. Automatic and attentional priming were determined by orthogonally varying prime–target relatedness, expectancy, and stimulus onset asynchrony. Although the CHI Ss had slower reaction times (RTs) overall, there were no significant group differences in the magnitude of either the automatic or attentional component of semantic priming. The present results indicate the integrity of semantic processes and normal semantic priming in long-term patients with severe CHI. The results are discussed in relation to an attentional resource hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)