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151.
多Agent系统是当前分布式人工智能研究的热点之一.探讨了单个Agent的结构特征以及多Agent系统的运行机制,结合Visual Prolog5.2和Visual C++6.0提出了一种实现多Agent系统的方案.尝试了多Agent系统背景下Choquet积分在综合评判问题中的应用. 相似文献
153.
SVD去噪技术对构造简单地区,特别是地层近水平的情况下的地震剖面的去噪效果是十分明显的;对于构造复杂地区,该法往往失效。针对这个问题,作者提出了一种新的技术:它将同相轴的自动追踪与SVD去噪技术有机地结合起来;它将一般的SVD方法是针对整个剖面数据体来计算的,改变为针对每一样点的邻区,选择小时窗和小道窗的数据体来计算;它利用数据体的旋转方法,来实现同相轴始终保持水平方向;并采取了其他一系列的技术措施,使SVD方法在构造复杂地区取得了很好的去噪效果 相似文献
154.
证明了描述数直线和坐标平面的连续性的一些命题的等价性,如在坐标平面上,用致密性定理证明Cauchy收敛准则;用Cauchy收敛准则证明闭矩形套定理等,以弥补现行教材之不足. 相似文献
155.
Ray Ison Chris Blackmore Kevin Collins Sue Holwell Ben Iaquinto 《Systemic Practice and Action Research》2014,27(2):91-113
Two systemic inquiries, based on soft systems methodology (SSM), into the potential for using community of practice (CoP) theory by an Australian-government created research and development corporation to change its knowledge management (KM) strategy, are reported. Key staff were engaged in the inquiry into how to build a third-order KM strategy based on CoPs; an exploration of key published work on CoPs yielded four SSM activity models—‘being a community practice system’; ‘doing the work of imagination sub-system’; ‘doing the work of alignment sub-system’ and ‘doing the work of engagement sub-system’. These models can be used as heuristics to aid the purposeful design of CoPs in other settings. SSM, enacted as a systemic inquiry, can be understood as a form of systemic action research, which was well equipped to deal with CoP theory and, when enacted participatively, can generate important systemic insights. The inquiry began the process of fostering an appreciation of third order KM but, on the evidence available, did not lead to on-going commitment to a CoPs-based KM strategy. Future research should acknowledge how the framing of research situations influences the research process, the importance of the design of practice change settings and the limited evidence for purposeful interventions leading to successful CoPs. 相似文献
156.
表面张力是矿物棉生产的重要参数,直接影响到配料和工艺参数的选择.通过实验测量并建立模型预报系统研究了以高炉渣为主要原料制备矿物棉时熔体的表面张力.首先测量了Si O2(40%~60%)-Al2O3(5%~20%)-Ca O(20%~30%)-Mg O(5%)四元系的表面张力,其值处于350~500 m N·m-1之间;然后结合文献报道的表面张力数据,利用人工神经网络技术建立了Si O2(35%~60%)-Al2O3(5%~20%)-Ca O(20%~45%)-Mg O(0~10%)四元渣系的表面张力预报模型.该模型对成分范围内的表面张力预报平均误差为9.32%,预报精度较高,可以预报矿物棉熔体成分范围内的表面张力. 相似文献
157.
许多人认为排污权是一种权利。但基于污染物的性质、权利客体的要求以及污染物减排的目标,排污只是一种客观事实,并不是权利的依据,排污权不是一种权利。因此,排污权也不能有偿使用和交易,只有如此才能更好地减排。 相似文献
158.
针对质子交换膜燃料电池在机械应力下的气-液两相流进行数学模拟研究,建立了一个二维质子交换膜燃料电池非等温两相流多物理场稳态模型. 该模型综合考虑了固体力学、电化学、传热传质以及气液两相流的物理因素,研究了质子交换膜燃料电池在机械应力作用下的两相流分布.计算结果显示:在机械应力作用下,燃料电池肋板下方的多孔介质应力明显大于流道下方的应力,且在肋板和流道交界处下方的气体扩散层会产生明显的应力集中现象;随着电流密度的增加,阴极相对湿度逐渐增加,但阳极相对湿度会减小;液态水仅在阴极产生且主要在肋板下方的多孔介质内形成,其在阴极的饱和度随电流密度的增加而不断增加. 相似文献
159.
Kudernac T Ruangsupapichat N Parschau M Maciá B Katsonis N Harutyunyan SR Ernst KH Feringa BL 《Nature》2011,479(7372):208-211
Propelling single molecules in a controlled manner along an unmodified surface remains extremely challenging because it requires molecules that can use light, chemical or electrical energy to modulate their interaction with the surface in a way that generates motion. Nature's motor proteins have mastered the art of converting conformational changes into directed motion, and have inspired the design of artificial systems such as DNA walkers and light- and redox-driven molecular motors. But although controlled movement of single molecules along a surface has been reported, the molecules in these examples act as passive elements that either diffuse along a preferential direction with equal probability for forward and backward movement or are dragged by an STM tip. Here we present a molecule with four functional units--our previously reported rotary motors--that undergo continuous and defined conformational changes upon sequential electronic and vibrational excitation. Scanning tunnelling microscopy confirms that activation of the conformational changes of the rotors through inelastic electron tunnelling propels the molecule unidirectionally across a Cu(111) surface. The system can be adapted to follow either linear or random surface trajectories or to remain stationary, by tuning the chirality of the individual motor units. Our design provides a starting point for the exploration of more sophisticated molecular mechanical systems with directionally controlled motion. 相似文献
160.
A conserved mechanism of DEAD-box ATPase activation by nucleoporins and InsP6 in mRNA export 总被引:1,自引:0,他引:1
Superfamily 1 and superfamily 2 RNA helicases are ubiquitous messenger-RNA-protein complex (mRNP) remodelling enzymes that have critical roles in all aspects of RNA metabolism. The superfamily 2 DEAD-box ATPase Dbp5 (human DDX19) functions in mRNA export and is thought to remodel mRNPs at the nuclear pore complex (NPC). Dbp5 is localized to the NPC via an interaction with Nup159 (NUP214 in vertebrates) and is locally activated there by Gle1 together with the small-molecule inositol hexakisphosphate (InsP(6)). Local activation of Dbp5 at the NPC by Gle1 is essential for mRNA export in vivo; however, the mechanistic role of Dbp5 in mRNP export is poorly understood and it is not known how Gle1(InsP6) and Nup159 regulate the activity of Dbp5. Here we report, from yeast, structures of Dbp5 in complex with Gle1(InsP6), Nup159/Gle1(InsP6) and RNA. These structures reveal that InsP(6) functions as a small-molecule tether for the Gle1-Dbp5 interaction. Surprisingly, the Gle1(InsP6)-Dbp5 complex is structurally similar to another DEAD-box ATPase complex essential for translation initiation, eIF4G-eIF4A, and we demonstrate that Gle1(InsP6) and eIF4G both activate their DEAD-box partner by stimulating RNA release. Furthermore, Gle1(InsP6) relieves Dbp5 autoregulation and cooperates with Nup159 in stabilizing an open Dbp5 intermediate that precludes RNA binding. These findings explain how Gle1(InsP6), Nup159 and Dbp5 collaborate in mRNA export and provide a general mechanism for DEAD-box ATPase regulation by Gle1/eIF4G-like activators. 相似文献