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71.
Yewang Su Baohua Ji Yonggang Huang Kehchih Hwang 《Journal of Materials Science》2007,42(21):8885-8893
Wet adhesion is widely adopted in biological adhesion systems in nature. Wet adhesion is studied in this paper with the focus
on the effect of different contact shapes (flat, concave, convex, and ring-like) on the adhesion force. The evolution of the
liquid bridge between a fiber tip and substrate during the detaching process shows two transition points. The first transition
from the radius-controlled to the contact-angle controlled process is critical to influence the strength and robustness of
adhesion. We show that a concave shape is more effective than a flat one, while a convex shape has no advantage. A ring-like
contact shape has advantages in a hydrophobic environment and on a rough surface. 相似文献
72.
软件无线电中采样率转换技术的实现及在3G中的应用 总被引:1,自引:0,他引:1
目前移动通信标准繁多,且新旧体制混杂,很难做到统一.为了实现互连互通,目前比较可行的方法是采用软件无线电.采样率转换技术是实现互连互通的关键.文中针对第三代移动通信系统(3G)中不同通信体制的带宽、速率要求,根据分级变换的思想,对3G中的CDMA2000和TDSCDMA的采样率转换方案进行了设计,并对3G中的5种制式的采样率转换方案进行了分析比较.实验表明,这一方案可以在采样率变换的高效网络结构基础上进一步降低滤波运算量和存储量. 相似文献
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74.
TD-SCDMA系统基站间干扰分析 总被引:1,自引:0,他引:1
论文以TD-SCDMA通信系统为基础详细分析了TDD系统特有的干扰即基站间干扰问题,同时介绍了基站间干扰分析的具体理论、分析方法和仿真结果,对于TDD系统的实际网络规划和设计具有指导意义。 相似文献
75.
Yanqing Ji Hao Ying John Yen Shizhuo Zhu Daniel C. Barth‐Jones Richard E. Miller R. Michael Massanari 《国际智能系统杂志》2007,22(8):827-845
Discovering unknown adverse drug reactions (ADRs) in postmarketing surveillance as early as possible is highly desirable. Nevertheless, current postmarketing surveillance methods largely rely on spontaneous reports that suffer from serious underreporting, latency, and inconsistent reporting. Thus these methods are not ideal for rapidly identifying rare ADRs. The multiagent systems paradigm is an emerging and effective approach to tackling distributed problems, especially when data sources and knowledge are geographically located in different places and coordination and collaboration are necessary for decision making. In this article, we propose an active, multiagent framework for early detection of ADRs by utilizing electronic patient data distributed across many different sources and locations. In this framework, intelligent agents assist a team of experts based on the well‐known human decision‐making model called Recognition‐Primed Decision (RPD). We generalize the RPD model to a fuzzy RPD model and utilize fuzzy logic technology to not only represent, interpret, and compute imprecise and subjective cues that are commonly encountered in the ADR problem but also to retrieve prior experiences by evaluating the extent of matching between the current situation and a past experience. We describe our preliminary multiagent system design and illustrate its potential benefits for assisting expert teams in early detection of previously unknown ADRs. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 827–845, 2007. 相似文献
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78.
H. Ji J. E. Dolbow 《International journal for numerical methods in engineering》2004,61(14):2508-2535
We consider a problem stemming from recent models of phase transitions in stimulus‐responsive hydrogels, wherein a sharp interface separates swelled and collapsed phases. Extended finite element methods that approximate the local solution with an enriched basis such that the mesh need not explicitly ‘fit’ the interface geometry are emphasized. Attention is focused on the weak enforcement of the normal configurational force balance and various options for evaluating the jump in the normal component of the solute flux at the interface. We show that as the reciprocal interfacial mobility vanishes, it plays the role of a penalty parameter enforcing a pure Dirichlet constraint, eventually triggering oscillations in the interfacial velocity. We also examine alternative formulations employing a Lagrange multiplier to enforce this constraint. It is shown that the most convenient choice of basis for the Lagrange multiplier results in oscillations in the multiplier field and a decrease in accuracy and rate of convergence in local error norms, suggesting a lack of stability in the discrete formulation. Under such conditions, neither the direct evaluation of the gradient of the approximation at the phase interface nor the interpretation of the Lagrange multiplier field provide a robust means to obtain the jump in the normal component of solute flux. Fortunately, the adaptation and use of local, domain‐integral methodologies considerably improves the flux evaluations. Several example problems are presented to compare and contrast the various techniques and methods. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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