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81.
R.P. Taleyarkhan J. Lapinskas B. Archambault J.A. Webster T.F. Grimes A. Hagen K. Fisher S. McDeavitt W. Charlton 《Chemical Engineering Research and Design》2013
Spent nuclear fuel chemical reprocessing plants process several 103 kg of spent nuclear fuel, especially Pu isotopes, which present significant potential for terrorism (Note: ∼8 kg Pu constitutes a threat level quantity). This requires detecting actinides in transit, but also, to ensure they are not diverted. Present-day sensors disallow real-time monitoring leading to significantly non-optimal operations. 相似文献
82.
The familiar question, "Who is the client?" has become a distraction from more important ethical questions. By requiring a singular answer, the question obscures the fact that psychologists have ethical obligations toward every party in a case, no matter how many or how named. Making the question plural is not a sufficient solution, because identifying the client(s) should not be treated as an end in itself; it is simply a means of clarifying the nature of the relationship(s) and understanding the accompanying ethical obligations. After exploring the underlying implications for informed consent, confidentiality, and other ethical duties, the author suggests that psychologists adopt an alternative ethical question: "What are my ethical responsibilities to each of the parties in this case?" Finally, a case example illustrates the fact that the old question has several different meanings (and therefore different answers), depending upon whether it is asked as an ethical, clinical, legal, or reimbursement question. The proposed new question avoids such confusion because it is easily identifiable as an ethical question and its meaning is clear. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
83.
Fisher DL Laurie NE Glaser R Connerney K Pollatsek A Duffy SA Brock J 《Human factors》2002,44(2):287-302
Driver education classes were once seen as a remedy for young drivers' overinvolvement in crashes, but research results from the early 1970s were disappointing. Few changes in the content or methods of instruction occurred until recently, but this could change rapidly. Personal computers (PCs) can now present videos or photorealistic simulations of risky, cognitively demanding traffic scenarios that require quick responses without putting the participant at risk. As such programs proliferate, evaluating their effectiveness poses a major challenge. We report the use of a fixed-base driving simulator to study the effects of both experience on the road and PC-based risk awareness training on younger drivers' part-task simulator driving performance in risky traffic scenarios. We ran three groups of drivers on the simulator: one group first trained on the PC (younger, inexperienced drivers) and two groups who received no PC training (younger, inexperienced and experienced drivers). Overall, the younger, inexperienced drivers who were trained on a PC operated their vehicles in risky scenarios in ways that differed measurably from those of the untrained younger, inexperienced drivers and, more important, in ways that we believe would decrease their exposure to risk considering that, on average, their behavior was more similar to the behavior of the untrained, experienced drivers. More research is needed to demonstrate whether these findings apply on the open road to the larger population of younger drivers. However, at least initially, the research suggests that PC-based risk awareness training programs have the potential to reduce the high crash rate among younger, inexperienced drivers. 相似文献
84.
故障现象:制冷正常,但制热时烧熔丝。分析与检测:该空调安装好后,试机时只试了制冷状态,制冷工作正常,却未进行制热试机。后来用户想试一下制热,拨到制热挡,熔断器一开机就跳闸,等合上闸后整机就无任何反应了。最初分析也许是巧合,检查主控板上的熔丝已经烧了,随即更换上了一块线路板,试机制冷正常,但在制热状态立刻烧熔断,判断制热存在严重短路现象。即然制冷正常,制热状态只多一个四通阀线圈用电,检查室外机的接线,原来是安装工错将三跟导线中的黄线接到了地上。 相似文献
85.
Social-network analysis generally helps researchers understand how groups of people interact. In this article the author uses small-scale egocentric social networks, based on volitional, explicit connections, to understand how people manage their personal and group communications. Two research projects using this approach show that such networks can give researchers important insight into the people who communicate online. Soylent, a project based on email, shows several common patterns in social interaction. The Roles project, based on Usenet newsgroups, suggests that various online social spaces can behave very differently from each other. 相似文献
86.
Fisher E. Tabrikian J. Dubnov S. 《IEEE transactions on audio, speech, and language processing》2006,14(2):502-510
In this paper, a novel method for voiced-unvoiced decision within a pitch tracking algorithm is presented. Voiced-unvoiced decision is required for many applications, including modeling for analysis/synthesis, detection of model changes for segmentation purposes and signal characterization for indexing and recognition applications. The proposed method is based on the generalized likelihood ratio test (GLRT) and assumes colored Gaussian noise with unknown covariance. Under voiced hypothesis, a harmonic plus noise model is assumed. The derived method is combined with a maximum a-posteriori probability (MAP) scheme to obtain a pitch and voicing tracking algorithm. The performance of the proposed method is tested using several speech databases for different levels of additive noise and phone speech conditions. Results show that the GLRT is robust to speaker and environmental conditions and performs better than existing algorithms. 相似文献
87.
Multicast networking lets designers use new communication patterns in computer graphics applications. This article introduces multicasting, explains how it differs from more traditional networking, and describes multicasting issues for the application designer 相似文献
88.
The development and application of a new electrochemical device using a computer-aided design strategy is reported. This novel design is based on the flow of electrolyte solution past a microwire electrode situated centrally within a large duct. In the design stage, finite element simulations were employed to evaluate feasible working geometries and mass transport rates. The computer-optimized designs were then exploited to construct experimental devices. Steady-state voltammetric measurements were performed for a reversible one-electron-transfer reaction to establish the experimental relationship between electrolysis current and solution velocity. The experimental results are compared to those predicted numerically, and good agreement is found. The numerical studies are also used to establish an empirical relationship between the mass transport limited current and the volume flow rate, providing a simple and quantitative alternative for workers who would prefer to exploit this device without the need to develop the numerical aspects. 相似文献
89.
Fisher GM Killeen TL Wu Q Reeves JM Hays PB Gault WA Brown S Shepherd GG 《Applied optics》2000,39(24):4284-4291
Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (~86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause. 相似文献
90.
Effects of altering energy and protein supply to dairy cows during the dry period. 1. Intake, body condition, and milk production 总被引:1,自引:0,他引:1
We used 48 Holstein-Friesian cows to investigate the effects of altering energy and protein supply to dry cows. Cows were fed one of three diets for 6 wk prior to parturition: (a) a 60:40 (DM basis) mixture of grass silage with barley straw ad libitum; (b) grass silage ad libitum; or (c) 0.5 kg/d of prairie meal with grass silage ad libitum. The standard lactation diet was a flat-rate allocation of concentrates and grass silage ad libitum. We evaluated dry-period diets using four dry fistulated cows; rumen pH remained high (mean = 6.6) and ammonia concentrations followed N intake. The inclusion of straw reduced apparent ruminal digestion of OM, N, and NDF as well as microbial protein yield, though microbial yield per unit of OM apparently digested in the rumen remained unchanged. Voluntary intake of forage was reduced by the inclusion of straw, while the inclusion of prairie meal had little effect. The decline in intake as calving approached was lower with the silage and straw mix diet. There were large differences in the BW change over the final 5 wk of the dry period, although the opposite effect was seen in early lactation, and differences in BW and body condition score were small by lactation wk 22. Despite the substantial differences in nutrient supply and effects on body reserves, there was little effect of dry-period diet on subsequent performance. Lower forage intakes and yields of protein and lactose were confined to the first month of lactation for cows previously offered straw. 相似文献