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11.
Pulsed Field Magnetometers (PFMs) offer a method for high speed full loop characterisation of hard magnetic materials. As there is no dependency on iron to close a circuit, the repeatability of the technique is good. By utilising Peltier effect techniques to control the temperature of the measurement coil systems employed in a Pulsed Field Magnetometer, the level of repeatability of measurements can be significantly improved.  相似文献   
12.
This paper presents an efficient face segmentation algorithm based on binary partition tree. Skin-like regions are first obtained by integrating the results of pixel classification and watershed segmentation. Facial features are extracted by the techniques of valley detection and entropic thresholding, and are used to refine the skin-like regions. In order to segment the facial regions from the skin-like regions, a novel region merging algorithm is proposed by considering the impact of the common border ratio between adjacent regions, and the binary partition tree is used to represent the whole region merging process. Then the facial likeness of each node in the binary partition tree is evaluated using a set of fuzzy membership functions devised for a number of facial primitives of geometrical, elliptical and facial features. Finally, an efficient algorithm of node selecting in the binary partition tree is proposed for the final face segmentation, which can exactly segment the faces without any underlying assumption. The performance of the proposed face segmentation algorithm is demonstrated by experimental results carried out on a variety of images in different scenarios.  相似文献   
13.
《Computer Networks》2007,51(3):699-711
We consider in this paper a WCDMA system with two types of calls: real time (RT) calls that have dedicated resources, and data non-real time (NRT) calls that are treated using a time-shared channel (such as the HDR or the HSDPA). We consider reservation of some resources for the NRT traffic and assume that this traffic is further assigned the resources left over from the RT traffic. The grade of service (GoS) of RT traffic is also controlled in order to allow for handling more RT calls during congestion periods, at the cost of degraded transmission rates. We consider both the downlink (with and without macrodiversity) as well as the uplink and study the blocking probabilities of RT traffic as well as the expected sojourn time of NRT traffic. We further study the conditional expected sojourn time of a data connection given its size and the state of the system. Finally, we extend our framework to handle handover calls.  相似文献   
14.
《Computer Networks》2007,51(9):2234-2248
Smart cards are secure tokens that have provided security services to a wide range of applications for over thirty years. Along with other technology advances, smart card technology has changed dramatically as well. However, its communication standards, largely unchanged, do not match with those of mainstream computing, which has limited its success in the Internet age. For nearly a decade, researchers have sought to connect smart cards to the Internet. The benefits are plentiful, including providing services over the Internet and eliminating smart card specific infrastructure. A key to this quest is to equip smart cards with a secure and effective networking capability. Various approaches have been taken to find this key. There is still much work to do. This paper reviews years of research in this area, looks at the state of the art, and analyzes and compares various networking options for smart cards. Furthermore, the paper outlines remaining technical challenges for making smart cards a part of the Internet world.  相似文献   
15.
Based on a polynomial operator approach, a new sparse controller structure is derived, which is actually an improved version of the recently proposed structure [Li, G. (2004). A polynomial-operator-based DFIIt structure for IIR filters. IEEE Transactions on Circuits and Systems II, 51, 147-151]. The performance of the proposed structure is analyzed by deriving the corresponding expression of roundoff noise gain and the problem of finding optimized sparse structures is solved efficiently with a genetic algorithm (GA). A numerical example is given, which shows that the newly developed structure can achieve much better performance than some well-known structures and particularly outperforms the traditional optimal fully parametrized realization greatly in terms of reducing roundoff noise and implementation complexity.  相似文献   
16.
《Computer Communications》2007,30(1):132-143
In the paper, we proposed a resource allocation method employing maximal compatible cliques to make use of channel bandwidth as efficiently as possible in a TD-CDMA system. Furthermore, the strength of beacon signals was also measured to decide whether or not to reserve resources for hand-off users, in order to reduce their dropping probabilities. Finally, we conducted several experiments to validate that our method could make use of the finite resources efficiently, thereby revealing better blocking probabilities and dropping probabilities than other methods.  相似文献   
17.
This paper concerns the stability analysis problem of discrete linear systems with state saturation using a saturation-dependent Lyapunov functional.We introduce a free matrix characterized by the sum of the absolute value of each elements for each row less than 1,which makes the state with saturation constraint reside in a convex polyhedron.A saturation-dependent Lyapunov functional is then designed to obtain a sufficient condition for such systems to be globally asymptotically stable.Based on this stability criterion,the state feedback control law synthesis problem is also studied.The obtained results are formulated in terms of bilinear matrix inequalities that can be solved by the presented iterative linear matrix inequality algorithm.Two numerical examples are used to demonstrate the effectiveness of the proposed method.  相似文献   
18.
19.
介绍了语义分析的发展现状。针对目前解释器语义分析效率较低的问题,并结合工业机器人控制系统的特点,研究了利用语法分析栈来实现工业机器人解释器语义分析的方法,并实现了工业机器人编程语言IRL的语义分析。基于该方法的解释器在Visual Studio2005平台上用C++实现,生成的目标代码运行于WinCE嵌入式系统。实验结果证明了该方法的正确性和高效性。  相似文献   
20.
传统遗传算法的选择策略缺乏多样性保护机制,易出现早熟收敛。为解决智能组卷问题,采取小生境技术完成遗传操作中的种群进化机制。利用个体浓度的大小,设置自适应变异算子,保证种群多样性,防止种群陷入局部收敛;增加阈值以保证算法在接近最优解时回归到自适应遗传算法,简化算法计算量,加快算法的收敛速度。本文提出一种自适应与小生境技术复合遗传算法,来均衡算法的全局搜索和局部快速开发能力。最后,实例验证了所提算法的有效性。  相似文献   
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