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71.
Structural and Multidisciplinary Optimization - The ubiquitous uncertainties presented in the input factors (e.g., material properties and loads) commonly lead to occasional failure of mechanical...  相似文献   
72.
网络机器人(Web Robo)t是一种自动化获取网页数据的程序。实践中使用对特定主题感兴趣的网络机器人获取数据,与数据库中数据进行比对,得出有用的结果。  相似文献   
73.
Active worms have posed a major security threat to the Internet and many research efforts have focused on them. However, defending against them remains challenging due to their continuous evolution. In this paper, we study a new class of defense-oriented evolved worms, the Varying Scan Rate worm (the VSR worm in short). In order to circumvent detection by existing worm detection schemes, the VSR worm deliberately varies its scan rate according to these schemes’ weaknesses. To counteract the VSR worm, we design a new worm-detection scheme, the attack-target Distribution Entropy-based Dynamic detection scheme (DED detection for short). DED detection utilizes the attack-target distribution and robust statistical feature in conjunction with dynamic decision adaptation to distinguish worm-scan traffic from non-worm-scan traffic. We present a comparatively complete space of detection schemes and conduct extensive performance evaluations on the DED detection scheme compared with other schemes, using real-world Internet traces as background scan traffic. Our data clearly demonstrate the effectiveness of the DED detection scheme in detecting both the VSR worm and the traditional worm.  相似文献   
74.
<正>目前,嵌入式技术日益成熟并越来越广泛地应用于工业自动化、医疗监测、通信、汽车电子、生活娱乐等各个领域。迄今为止,只要我们目之能及,嵌入式系统已经"无处不在"、"无所不能"。嵌入式技术在中国有着巨大的发展潜力和市场需求,中国嵌入式市场朝气蓬勃,发展  相似文献   
75.
<正>一直以来,基于传感器的系统电路的设计不仅极为耗时、复杂,而且需要针对每个系统开发专用的设计方案。从伊始的挑选传感器、搜索并分析元器件、评估系统性能,到线路布局及电路板装配、核实设计,直至最终的系统建模,很多工程师都要花费几周甚至几个月的时间才能成功开发出一款定制的模拟传感器解决方案,这无疑成为困扰众多工程师的一大难题。  相似文献   
76.
指出在Windos98操作系统下远程维护的必要性,并从理论上分析了实现远程维护的可能性,最后给出实现远程维护的两种方法。  相似文献   
77.
Ultra-thin membrane with nanoscale through hole has great potential in biomedical applications, where precise controllability of porosity, pore size and film thickness is urgently required. The present work proposed a cost-effective way to prepare the ultra-thin nanoporous film with a promising controllability. Monodispersed nanoparticle, rather than photoresist, is used as the sacrificial material for this new lift-off process. By releasing the particles, holes can be achieved with predeter-mined characters. A 110 nm-thick nanoporous aluminum film with well-controlled pore's diameter was successfully fabricated to validate the technique. The technique has wider process window and better applicability than other nanofabrication methods.  相似文献   
78.
Evaluation of renal vasculature was necessary for preoperative donor assessment in living donor kidney transplantation, and the ability to view the vascular imaging in three-dimensional (3D) space should be helpful undoubtedly. Considering the widespread use of personal computer (PC) systems, we aimed to find a handy way to display the anatomy of the renal arterial and venous systems of potential donors on PC-Windows platform. Ten living-related donors were included in this study. Serial computed tomography (CT) images were loaded into Amira 3.1 running on a PC with Windows XP. Following image crop, segmentation and 3D reconstruction, we got the 3D images and the video clips. According to the displays which were confirmed by latter intraoperative findings, eight donors had single renal vessels, one had a left accessory renal artery and one had a right accessory renal artery. This project offered a new approach to evaluate the renal vessel anatomy in living donor kidney transplantation, and it was favorable for accuracy and popularizing.  相似文献   
79.
消除485总线噪声影响的应用一例   总被引:7,自引:0,他引:7  
就一实例说明如何通过软件设计的方法来消除系统中存在的各种噪声,保证系统的正常运行。  相似文献   
80.
We show that it is possible to collect data that are useful for collaborative filtering (CF) using an autonomous Web spider. In CF, entities are recommended to a new user based on the stated preferences of other, similar users. We describe a CF spider that collects from the Web lists of semantically related entities. These lists can then be used by existing CF algorithms by encoding them as ‘pseudo-users'. Importantly, the spider can collect useful data without pre-programmed knowledge about the format of particular pages or particular sites. Instead, the CF spider uses commercial Web-search engines to find pages likely to contain lists in the domain of interest, and then applies previously proposed heuristics to extract lists from these pages. We show that data collected by this spider are nearly as effective for CF as data collected from real users, and more effective than data collected by two plausible hand-programmed spiders. In some cases, autonomously spidered data can also be combined with actual user data to improve performance.  相似文献   
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