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961.
恒负温与变负温养护制度对混凝土性能的影响研究 总被引:4,自引:0,他引:4
实验及实际工程表明,在自然及人工变负温环境中掺防冻剂混凝土的强度远高于在恒负温养护下的强度。就恒负温及变负温(人工、自然)养护制度下的掺防冻剂混凝土的性能进行对比研究,并分析负温混凝土显微结构,为改进掺防冻剂混凝土评价方法提供实验及理论基础。 相似文献
962.
混凝土材料的拓扑学特征及分形特征的评价 总被引:6,自引:0,他引:6
在分析比较了拓扑空间、分形空间以及拓扑维数、分形维数的基础上,用拓扑学和分形理论评价了混凝土材料的超细掺合料颗粒特征、粗集料表面特征、混凝土断裂表面和水泥石断裂表面特征以及混凝土孔隙显微结构等特征;研究表明对于超细硅灰、轻集料、卵石以及水泥石断裂表面可以用拓扑学的理论进行抽象化处理,对于超细粉煤灰、碎石、混凝土断裂表面以及孔隙显微结构等几何特征,采用分形理论是十分有效的,其分形维数大于它的拓扑维数,小于它的空间维数,符合相应的自然规律。 相似文献
963.
提出了一种利用简化潮流雅可比矩阵来缩短牛顿-拉夫逊潮流计算收敛时间的方法,并通过算例验证了其有效性。 相似文献
964.
Adrian David Cheok Xubo Yang Zhou Zhi Ying Mark Billinghurst Hirokazu Kato 《Personal and Ubiquitous Computing》2002,6(5-6):430-442
This paper presents a novel computer entertainment system which recaptures human touch and physical interaction with the
real-world environment as essential elements of the game play, whilst also maintaining the exciting fantasy features of traditional
computer entertainment. Our system called ‘Touch-Space’ is an embodied (ubiquitous, tangible, and social) computing based
Mixed Reality (MR) game space which regains the physical and social aspects of traditional game play. In this novel game space,
the real-world environment is an essential and intrinsic game element, and the human’s physical context influences the game
play. It also provides the full spectrum of game interaction experience ranging from the real physical environment (human
to human and human to physical world interaction), to augmented reality, to the virtual environment. It allows tangible interactions
between players and virtual objects, and collaborations between players in different levels of reality. Thus, the system re-invigorates
computer entertainment systems with social human-to-human and human-to-physical touch interactions.
Correspondence to: Professor A. Cheok, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. Email: adriancheok@nus.edu.sg 相似文献
965.
966.
The current trend in constructing high-performance computing systems is to connect a large number of machines via a fast interconnect or a large-scale network such as the Internet. This approach relies on the performance of the interconnect (or Internet) to enable fast, large-scale distributed computing. A detailed understanding of the communication traffic is required in order to optimize the operation of the entire system. Network researchers traditionally monitor traffic in the network to gain the insight necessary to optimize network operations. Recent work suggests additional insight can be obtained by also monitoring traffic at the application level. The Monitor for Application-Generated Network Traffic toolkit (MAGNeT) we describe here monitors application traffic patterns in production systems, thus enabling more highly optimized networks and interconnects for the next generation of high-performance computing systems. 相似文献
967.
Abstract. In an increasingly dynamic business environment characterized by fast cycle times, shifting markets and unstable technology, a business organization’s survival hinges on its ability to align IT capabilities with business goals. To facilitate the successful introduction of new IT applications, issues of project risk must be addressed, and the expectations of multiple stakeholders must be managed appropriately. To the extent that users and developers may harbour different perceptions regarding project risk, areas of conflict may arise. By understanding the differences in how users and project managers perceive the risks, insights can be gained that may help to ensure the successful delivery of systems. Prior research has focused on the project manager’s perspective of IT project risk. This paper explores the issue of IT project risk from the user perspective and compares it with risk perceptions of project managers. A Delphi study reveals that these two stakeholder groups have different perceptions of risk factors. Through comparison with a previous study on project manager risk perceptions, zones of concordance and discordance that must be reconciled are identified. 相似文献
968.
回顾了电压稳定的基本概念 ,提出了一种静态等值的新方法 ;同时提出了利用该方法的静态等值结果 ,快速绘制P V、Q V曲线的方法。数字仿真结果表明 ,该方法与实际潮流计算绘制的P V、Q V曲线在上半支和鼻形点附近均吻合得很好 ,从而验证了该方法的有效性。 相似文献
969.
970.
Traditional executive information systems (EIS) user support tends to focus on technical support rather than information support. Letting executives use EIS directly for strategic information has not been successful. Adopting a combined method of case study and survey, this study explored and examined the role of information support functions from U.K. executives' point of view. It found that the use of information specialists for external information scanning, information refining, and information reporting has been perceived as important to support executives in acquiring strategic information. However, information specialists' knowledge and capability in sensing and interpreting information, executive culture, the cost of establishing such a support role are the main concerns of executives. the paper suggests that EIS users need information support, as opposed to technical support. To be effective and successful, managers' knowledge in sensing, interpreting, and using information should be elicited and shared among information specialists in light of knowledge management. 相似文献