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The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless person-  相似文献   
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The intermetallic compound Mg2Ni has been prepared by the vapour exchange/diffusion reaction of the elements sealed in a stainless steel container. The product has been characterised by powder X-ray diffractometry with Mo-Kα radiation, using step-scanning and profile refinement techniques. The hexagonal unit cell has constants a = 5.2117(4), c = 13.2538(9) A?.  相似文献   
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差分式连续时间电流型CMOS跨导—电容低通滤波器   总被引:1,自引:0,他引:1  
郭静波  戴逸松 《微电子学》1996,26(6):359-362
应用信号流图法对电流系统传递函数直接模拟,提出了一种新颖的差分式连续时间电流模式CMOS跨导-电容低通滤波器的实现方案。由于采用了差分式结构和电流负反馈,整个电路方案具有差分式结构和电流型电路的优点;并且仅使用最少数量的OTA和电容,与数字CMOS工艺兼容,适于全集成。面向实际电路完成了MOS管级的计算机仿真,结果表明,所提出的电路方案正确有效  相似文献   
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Post-harvest loss of resources to microbial competitors affects a number of species of animals, and many of them have evolved behaviors that reduce the likelihood of such loss. We previously described the inhibition ofBacillus psychrophilus by dogwood fruits (Cornus drummondii), which can comprise a significant portion of the winter food cache of the eastern woodrat (Neotoma floridana). The present study is a further investigation of the ability of dogwood fruits to inhibit growth ofB. psychrophilus. Additionally, we tested the antimicrobial activity of dogwood fruits onEscherichia coli andStaphlococcus aureus. Results of our study indicate that fresh fruits inhibit the growth ofB. psychrophilus andS. aureus but notE. coli. However, fruits taken from woodrat dens after four and six months storage inhibited growth of all three species of bacteria. Further, the strength of inhibition increased over the test period. We suggest the presence of an inhibitor allows woodrats to compete effectively for a valuable and limited food resource.  相似文献   
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无线数据通信网发展趋势   总被引:1,自引:0,他引:1  
黄宇红  张必智 《世界电信》1996,9(1):32-34,37
无线数据通信具有两大发展趋势,即低速的广域移动数据网及高速的局域无线数据网。本文介绍了其技术特点、应用情况和市场前景,分析了无线数据通信传输技术、网络结构和媒质接入控制等问题。  相似文献   
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Healthy Aims is a 23- million, four-year project, funded under the EU's information society technology sixth framework program to develop intelligent medical implants and diagnostic systems (www.healthyaims.org). The project has 25 partners from 10 countries, including commercial, clinical, and research groups. This consortium represents a combination of disciplines to design and fabricate new medical devices and components as well as to test them in laboratories and subsequent clinical trials. The project focuses on medical implants for nerve stimulation and diagnostic equipment based on strain-gauge technology.  相似文献   
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In projection-based Virtual Reality (VR) systems, typically only one headtracked user views stereo images rendered from the correct view position. For other users, who are presented a distorted image, moving with the first user's head motion, it is difficult to correctly view and interact with 3D objects in the virtual environment. In close-range VR systems, such as the Virtual Workbench, distortion effects are especially large because objects are within close range and users are relatively far apart. On these systems, multi-user collaboration proves to be difficult. In this paper, we analyze the problem and describe a novel, easy to implement method to prevent and reduce image distortion and its negative effects on close-range interaction task performance. First, our method combines a shared camera model and view distortion compensation. It minimizes the overall distortion for each user, while important user-personal objects such as interaction cursors, rays and controls remain distortion-free. Second, our method retains co-location for interaction techniques to make interaction more consistent. We performed a user experiment on our Virtual Workbench to analyze user performance under distorted view conditions with and without the use of our method. Our findings demonstrate the negative impact of view distortion on task performance and the positive effect our method introduces. This indicates that our method can enhance the multi-user collaboration experience on close-range, projection-based VR systems.  相似文献   
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Abstract. Deciding when to adopt or introduce new information technology (IT) is a relatively difficult problem. This paper presents a method that can be used in many circumstances to evaluate new IT. The model is based on modelling the response of customers and rivals to services provided by IT. The methodology recognizes competitor reactions on two levels: within the local market and actions by rivals in the international market. The model examines behaviour, costs, and benefits over time. Several different types of models are examined, ranging from competitive (Nash) equilibriums to joint ventures. This model is illustrated by examining when banks should implement new technology. The results indicate that large banks can effectively utilize technology as a strategic weapon. Smaller, local banks are more limited in their control of technology. The model reveals some strategic uses that are not evident from existing models.  相似文献   
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