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41.
WM平台下反病毒软件的设计与实现 总被引:1,自引:0,他引:1
手机病毒的不断增多给用户带来很大的威胁,针对Windows Mobile平台给出一款反病毒软件。在软件中设计和实现一种快速、精确的病毒扫描引擎,并利用Windows Mobile平台的文件系统过滤器实现存储管理器下文件的实时监控和病毒扫描。 相似文献
42.
Today, due to the availability of free remote sensing data, efficient algorithms for image classification and increased connectivity and computing power, together with international policy initiatives, such as the United Nations Programme on Reducing Emissions from Deforestation and Forest Degradation (UN-REDD), more and more countries are investing in their own national forest monitoring schemes. However, tropical forests remain under threat worldwide. Recently, a citizen science project that enables citizens around the globe to be involved in forest monitoring tasks has been proposed, called “ForestWatchers” (www.forestwatchers.net). Its main goal is to allow volunteers (many of them with no scientific training) around the globe, with their own smartphones, tablets and notebooks, review satellite images of forested regions and confirm whether automatic assignments of forested and deforested regions are correct. Inspected images are then sent to a central database where the results are integrated to generate up-to-date deforestation maps. This approach offers a low-cost way to both strengthen the scientific infrastructure and engage members of the public in science. Here, we describe the methods developed within the scope of the ForestWatchers project to assess the volunteers’ performance. These tools have been evaluated with data of two of the project’s preliminary tasks. The first, called “BestTile”, asks volunteers to select which of several images of the same area has the least cloud cover, while in the second, called “Deforestation”, volunteers draw polygons on satellite images delimiting areas they believe have been deforested. The results from more than 500 volunteers show that using simple statistical tests, it is possible to achieve a triple goal: to increase the overall efficiency of the data collecting tasks by reducing the required number of volunteers per task, to identify malicious behavior and outliers, and to motivate volunteers to continue their contributions. 相似文献
43.
为了减少直线结构Sagnac分布式光纤传感系统的定位误差,提出一种多级零频点的优化方法,通过分析直线结构Sagnac分布式光纤传感定位原理,确定固定的采样速率下离散化是造成定位误差大的原因.并分析得出振动信号频域曲线会周期出现多个零频点,进而对振动定位的多级零频点优化方法进行了理论推导,阐明高倍零频点下的定位误差会有效减小.通过实验验证表明,在总长为11.769 km的传感光纤上,优化后的定位方法在不改变采样速率下可保证定位误差提升到±20 m范围内,可以基本满足系统对外界振动信号进行精确定位的要求. 相似文献
44.
Jesus Nuevo Luis M. Bergasa David F. Llorca Manuel Ocaña 《Image and vision computing》2011,29(4):209-218
This paper describes an active model with a robust texture model built on-line. The model uses one camera and it is able to operate without active illumination. The texture model is defined by a series of clusters, which are built in a video sequence using previously encountered samples. This model is used to search for the corresponding element in the following frames. An on-line clustering method, named leaderP is described and evaluated on an application of face tracking. A 20-point shape model is used. This model is built offline, and a robust fitting function is used to restrict the position of the points. Our proposal is to serve as one of the stages in a driver monitoring system. To test it, a new set of sequences of drivers recorded outdoors and in a realistic simulator has been compiled. Experimental results for typical outdoor driving scenarios, with frequent head movement, turns and occlusions are presented. Our approach is tested and compared with the Simultaneous Modeling and Tracking (SMAT) [1], and the recently presented Stacked Trimmed Active Shape Model (STASM) [2], and shows better results than SMAT and similar fitting error levels to STASM, with much faster execution times and improved robustness. 相似文献
45.
46.
基于ZigBee技术的远端通信站监控系统及其实现 总被引:1,自引:0,他引:1
提出了一种基于ZigBee技术的远端通信站环境监控系统设计方案。包括系统结构、Zigbee通信接口、单片微处理器、温度采集等模块的软硬件设计。此方案设计的监测系统已在某远端无人小型频谱监测站使用。 相似文献
47.
Identification of statistical patterns from observed time series of spatially distributed sensor data is critical for performance monitoring and decision making in human-engineered complex systems, such as electric power generation, petrochemical, and networked transportation. This paper presents an information-theoretic approach to identification of statistical patterns in such systems, where the main objective is to enhance structural integrity and operation reliability. The core concept of pattern identification is built upon the principles of Symbolic Dynamics, Automata Theory, and Information Theory. To this end, a symbolic time series analysis method has been formulated and experimentally validated on a special-purpose test apparatus that is designed for data acquisition and real-time analysis of fatigue damage in polycrystalline alloys. 相似文献
48.
《Ergonomics》2012,55(5):663-670
The aim of this study was to compare estimation of energy expenditure (EE) in working environments, either from accelerometry or from an individual oxygen consumption/heart rate ([Vdot]O2/HR) regression curve. The study participants were 46 volunteer workers aged 27±6 years old. A significant correlation between EE predicted by the [Vdot]O2/HR curve and the accelerometer was observed (r=0.78, p <0.01). However, more disparities were observed between the two methods when the mean job intensity was not within 16% and 23% higher than resting HR. The accelerometer overestimated by a mean of 34.4% the prediction by [Vdot]O2/HR regression if the intensity of the task was lower than a total of 1000 kcal/shift and underestimated the prediction by a mean of –24.9% if EE estimation of the work shift was higher than a total of 1500 kcal/shift. Despite a high correlation between both methods in the whole group, EE evaluated by accelerometry does not correspond to EE predicted by the [Vdot]O2/HR regression curves when evaluated individually. 相似文献
49.
50.
以不可压缩黏性流体的Navier-Stokes方程为控制方程,采用RNG k-ε湍流模型,利用VOF方法追踪运动的自由表面的方法,建立了三维数值波浪与振动柱体相互作用的模型.基于经典绕射理论验证了波浪绕固定柱体传播的数值模型的可靠性,再采用动边界技术赋予柱体振动规律,研究受控振动柱体对波浪传播的影响,并通过控制柱体初始振动相位变化,系统地给出了在柱体振动的不同初始相位下柱体前后波浪变化的规律. 相似文献