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31.
R.A. Forrest 《Fusion Engineering and Design》2006,81(18):2143-2156
Existing neutron cross section libraries such as EAF-2003 contain a large number of reactions. Of these only a small proportion are significant in the production of the nuclides that dominate activation quantities such as activity or γ-dose rate at various decay times. These reactions were identified in a recent extensive set of calculations on all the elements and reported in the ‘Activation Handbook’. These 1340 reactions are considered here and the set of reactions with no differential or integral data are listed and prioritised. A set of 339 reactions with very limited possibility of measurement are given; these require further study by theoretical calculations. A set of 100 reactions with either discrepant or no data, that might be measurable are listed and are recommended to be the subject of future experimental work. 相似文献
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Many school systems, in both the developed and developing world, are implementing educational technology to assist in student learning. However, there is no clear consensus on how to evaluate these new technologies. This paper proposes a comprehensive methodology for estimating the value of a new educational technology in three steps: benefit analysis, through the administration of a well-designed experiment; cost analysis, which incorporates costs to weigh against the benefits; and feasibility analysis, which introduces real-world concerns that may affect the ability to actually implement the technology. To illustrate the methodology, a case study from Chile is used where portable educational video games were introduced into first and second grade classrooms with the aim of improving learning in mathematics and language. This paper demonstrates the importance of all three steps in the evaluation process and provides a framework for future analyses. 相似文献
34.
在10 ̄(-5)_eV-20MeV中子能量范围内对天然汞的中子核数据进行评价。评价内容包括总的、弹性、去弹、总非弹、30条分立能级、连续非弹、(n,2n)、(n,3n,)、(n,n'P)、(n,n'α)、(n,P)、(n,α)、(n,d)、(n,t)和(n,γ)截面;次级中子角分布;双微分截面(DDCS);γ射线产生数据等。评价根据有效实验数据(至1993年)和UNF-92 ̄[1]理论计算。评价数据以ENDF/B6格式录入中国评价核数据库CENDL-2.1版(MAT=1800),并提供核工程有关部门使用。 相似文献
35.
闫承恂 《数码设计:surface》2012,(7):49-50
文章将广告创意的产生分为准备、分析、顿悟和评估四个阶段,针对每个阶段的工作重点、工作方法进行阐述,涉及到多种思维方式和创意技巧,旨在说明创意不能仅靠天赋,更应源于科学的方法和步骤。 相似文献
36.
介绍并评述人机界面可用性的定义、可用性测试与评估的指标及方法。学术界对于可用性的内涵已基本达成共识,但大多针对不同界面选取不同的测试与评估指标及权重,测试与评估方法也大都停留于主观评价,还未能深入探讨用户与系统交互过程中的内在心理机制。 相似文献
37.
《水科学与水工程》2021,14(4):330-336
The unique structure of a dam complicates safety monitoring. Deformation can provide important information about dam evolution. In contrast to model prediction, actual dam response monitoring data can be used for diagnosis and early warning. Given the poor data mining ability of the conventional methods, it is essential to develop a method for extracting the factors influencing a dam. In this study, a data mining method and a model for evaluation of concrete dam deformation were developed using the evidence theory and a random forest. The model has the advantages of being easily understood, visualization with low complexity of training time, and accurate prediction. The model was applied to an actual concrete dam. The results indicated that the proposed random forest model could be used in analysis of concrete dams. 相似文献
38.
Subjective workload and situation awareness measures, such as the NASA task load index (TLX) and the situational awareness rating technique (SART), are frequently used in human–system evaluation. However, the interpretation of these ratings is debated. In this study, empirical evidence for the measures' theoretical assumptions was investigated by comparing operators' ratings collected immediately after performing a scenario and ratings collected after operators' acquisition through a video review of the scenario, knowledge of actual system states. Eighteen licensed control room operators participated in the simulator study, running 12 relatively challenging scenarios. It was found that the interpretation of TLX items involving introspection remained stable after operators acquired factual scenario knowledge, while the interpretation of items involving the perception of external events, such as situation awareness and performance, depended on the operators' scenario knowledge. The result shows that operators’ ratings could discriminate between mental effort, performance, frustration, and situation awareness. No clear evidence for the SART index as a measure of situation awareness was found. Instead, a subjective situation awareness measure developed for this study was distinct from workload and related to operator performance, showing that this type of measure warrants future investigation of its validity. The study findings help in developing measurement procedures and interpreting subjective measures. Finally, the study reveals that informing operators about the scenario can provide useful subjective ratings of situation awareness and performance. Future research should include procedures for how to inform participants adequately and efficiently in subjective assessments. 相似文献
39.
谷灵康 《自动化与信息工程》2012,(2):13-16,22
本文在充分分析国内外立体显示技术评价方法的基础上,提出了利用视差和分层渲染的方法进行立体显示效果的评价,结果表明其对于自由立体显示评价可以得到较明确的分析结果,最后对研究前景进行了必要的探讨。 相似文献
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