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本文针对多通道线性系统,给出了Luenberger形式的观测器,讨论了其收敛的条件,利用多通道线性系统特征结构配置理论,给出了设计的方法,并给出了实例和仿真结果。 相似文献
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本文论述了计算机辅助逻辑模拟的基本方法,给出了门级逻辑模拟算法,并在IBMPC-286上编程实现。文中对算法进行了分析。给出算法的时间和空间复杂度。最后给出实例,实践表明,使用本文给出的算法可取得与实际吻合的模拟结果。 相似文献
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陈锐 《计算机技术与发展》2006,16(8):30-34
在多维数据压缩的基础上,提出了多维数据的CUBE计算方法。首先给出了无限内存算法,其次给出了一个不完全立方体算法,最后给出了完整立方体的计算方法。并与其他CUBE算法作了比较。 相似文献
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本指出了《单片机系统的加密技术》一中的四个理论性错误,给出了理论证明和分析,好其好的加密方法给出了理论上保密性能的分布,并给出了一种较好的加密算法。 相似文献
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基于AI的主动数据挖掘技术在网络故障管理中的应用 总被引:3,自引:0,他引:3
讨论了基于人工智能的主动空间数据挖掘技术在故障管理中的应用,给出了一个应用模型,其中主动空间数据挖掘技术主要体现在数据融合,数据挖掘和知识发现的过程中,文中首先给出了规则定义和触发器定义,并对专家系统的知识发现过程给出了基于时间窗口的告警关联算法,最后给出了在仿真环境下的系统性能测试分析,模型实现和分析数据表明该模型是的可行的。 相似文献
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基于逆向FD超图的属性闭包求解算法研究 总被引:4,自引:0,他引:4
本文对文⑴进行深入分析的基础上给出了正向FD超图、逆向FD超图,给出了正向、逆向超图的相互转换算法,并对属性闭包的求法进行了研究,给出了求解关系模式属性闭包的新算法。 相似文献
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Spatial heterogeneity in ecosystem functioning is a key component of ecological variability requiring special attention in the context of global change. A large history of human use has produced high physiognomic heterogeneity in Mediterranean ecosystems. However, the consequences for ecosystem functioning remain insufficiently understood. We analyzed spectral indicators of matter and energy fluxes in the land surface to classify the functional ecosystem heterogeneity in a Mediterranean region covering different management histories and protection types. We specifically analyzed the spatial variability in seasonal and annual patterns in the Normalized Difference Vegetation Index (NDVI), surface temperature (Ts) and albedo from five Landsat ETM images. Then we classified numerically this variability into ecosystem functional types (EFTs) and explored their seasonal dynamics in terms of photosynthetic radiation absorption and evapotranspiration. We identified eight main EFTs with ecologically relevant differences including contrasting dynamics in fPAR seasonality, great variation in incoming radiation reflection and differing evapotranspiration rates, particularly during the water-limitation period. Functional variability in natural vegetation mostly consisted in dissimilar annual rates of NDVI and albedo, whereas differences in seasonality were more evident in transformed areas. Similarly, the spatial distribution of EFTs was partly associated to protection, with two EFTs exclusive of protected areas and comparatively higher functional diversity in humanized areas. Landform effects on water availability in protected areas and human activities under different ecological settings were seemingly responsible for the large functional diversity of the region. We advocate for the explicit incorporation of multifunctional ecosystem heterogeneity in ecosystem management and monitoring designs. 相似文献
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生物组织光声成像技术综述 总被引:1,自引:0,他引:1
光声成像是一种低功率、非电离的成像方式,既具有声学方法对深层组织成像分辨率高的优点,又具有光学方法在功能成像、分子成像方面具有高对比度的优势。本文回顾了近年来,光声成像技术在生物医学领域的研究进展,介绍了光声成像的基本成像原理。以此为基础,本文介绍了光声成像的两种主要成像方案:光声断层成像和光声显微镜,并且讨论了光声成像在获取生物组织化学成分信息和微结构信息方面的优越性;最后,本文对光声成像技术的优点和应用前景进行了总结。 相似文献
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Abstract Information and Communication Technologies (ICT) are now widespread in Australian schools but with variation in how, where, when and how much they are used. Computers may be located in a computer laboratory, distributed throughout the school, or students may use their own laptop computers. IT may be a subject in its own right or ICT may be used across all areas of the curriculum. It is how ICT is used in the school setting that is important in providing students with the skills to be participate in a 'knowledge society'. This paper examines the ways in which information and communication technologies influence teaching and learning in five Australian schools. Data were gathered through observation, interviews and document analysis in schools operating at the elementary and secondary grades in relatively technology rich environments. Each of the schools participated in the Australian component of the Second Information Technology in Education Study – Module 2 (SITES-M2) of innovative pedagogical practices. Several of the studies were of specific projects where ICT was the key enabler of the learning programme. Others focused on an entire school's approach to ICT as an agent for changed approaches to learning. 相似文献
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Data on health and lifestyle from the Naval service cohort study of occupational stress form the background to a discussion of employee health and the sustainability of a healthy workforce in relation to secular changes – in particular, the increasing prevalence of obesity. One thousand two hundred and forty-one Naval personnel returned questionnaires in 2007 and 2011 and reported their body mass index (BMI), alcohol consumption and smoking, general health and health conditions such as back pain and high blood pressure on both occasions. Health risk due to high BMI and waist circumference in 2011 was predicted by low participation in exercise in 2007. Those performing physically demanding work in 2007 were more likely to be in the ‘no risk’ category in 2011. High BMI in 2007 was associated with the development of back pain, musculoskeletal conditions and high blood pressure in 2011. The findings are discussed in relation to two aspects of sustainability: the sustainability of current ergonomics practice in relation to health and safety; and the role of ergonomics in sustaining a healthy and productive workforce. Practitioner Summary: Evidence is presented for the benefits of exercise in sustaining employee health and for an association between a high BMI and a number of common health complaints that have traditionally been tackled through workplace ergonomics. This evidence can be used to support the development of workplace design concepts that promote physical activity. 相似文献
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自定义位图在激光传输仿真中的应用 总被引:1,自引:0,他引:1
提出了一种在激光大气传输仿真中创建和实时显示自定义位图的方法。它将数值仿真中得到的激光能量数据在VC++中以位图的形式显示出来,使人能直观、准确、及时地感受到整个仿真过程中激光能量的变化及分布情况。该方法可依据数值仿真结果自主设计调色板、创建和绘制DIB位图,且方便、快捷,能满足仿真的实时性要求。 相似文献
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Mohammad Ali Badamchizadeh Sohrab Khanmohammadi Gasem Alizadeh Ali Aghagolzade 《International Journal of Control, Automation and Systems》2009,7(3):331-339
Considering an infinite number of eigenvalues for time delay systems, it is difficult to determine their stability. We have
developed a new approach for the stability test of time delay nonlinear hybrid systems. Construction of Lyapunov functions
for hybrid systems is generally a difficult task, but once these functions are found, stability’s analysis of the system is
straight-forward. In this paper both delay-independent and delay-dependent stability tests are proposed, based on the construction
of appropriate Lyapunov-Krasovskii functionals. The methodology is based on the sum of squares decomposition of multivariate
polynomials and the algorithmic construction is achieved through the use of semidefinite programming. The reduction techniques
provide numerical solution of large-scale instances; otherwise they will be computationally infeasible to solve. The introduced
method can be used for hybrid systems with linear or nonlinear vector fields. Finally simulation results show the correctness
and validity of the designed method.
Recommended by Editorial Board member Young Soo Suh under the direction of Editor Jae Weon Choi. The authors wish to express
their thanks to Dr. A. Papachristodoulou and Dr. M. Peet for their helpful comments and suggestions.
Mohammad Ali Badamchizadeh was born in Tabriz, Iran, in December 1975. He received the B.S. degree in Electrical Engineering from University of Tabriz
in 1998 and the M.Sc. degree in Control Engineering from University of Tabriz in 2001. He received the Ph.D. degree in Control
Engineering from University of Tabriz in 2007. He is now an Assistant Professor in the Faculty of Electrical and Computer
Engineering at University of Tabriz. His research interests include Hybrid dynamical systems, Stability of systems, Time delay
systems, Robot path planning.
Sohrab Khanmohammadi received the B.S. degree in Industrial Engineering from Sharif University, Iran in 1977 and the M.Sc. degree in Automatic
from University Paul Sabatie, France in 1980 and the Ph.D. degree in Automatic from National University, ENSAE, France in
1983. He is now a Professor of Electrical Engineering at University of Tabriz. His research interests are Fuzzy control, Artificial
Intelligence applications in control and simulation on industrial systems and human behavior.
Gasem Alizadeh was born in Tabriz, Iran in 1967. He received the B.S. degree in Electrical Engineering from Sharif University, Iran in 1990
and the M.Sc. degree from Khajeh Nasir Toosi University, Iran in 1993 and the Ph.D. degree in Electrical Engineering from
Tarbiat Modarres University, Iran in 1998. From 1998, he is a Member of University of Tabriz in Iran. His research interests
are robust and optimal control, guidance, navigation and adaptive control.
Ali Aghagolzadeh was born in Babol, Iran. He received the B.S. degree in Electrical Engineering in 1985 from University of Tabriz, Tabriz,
Iran, and the M.Sc. degree in Electrical Engineering in 1988 from the Illinois Institute of Technology, Chicago, IL. He also
attended the School of Electrical Engineering at Purdue University in August 1998 where he was also employed as a part-time
research assistant and received the Ph.D. degree in 1991. He is currently an Associate Professor of Electrical Engineering
at University of Tabriz, Tabriz, Iran. His research interests include digital signal and image processing, image coding and
communication, computer vision, and image analysis. 相似文献
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Summary Algorithms for mutual exclusion that adapt to the current degree of contention are developed. Afilter and a leader election algorithm form the basic building blocks. The algorithms achieve system response times that are independent of the total number of processes and governed instead by the current degree of contention. The final algorithm achieves a constant amortized system response time.
Manhoi Choy was born in 1967 in Hong Kong. He received his B.Sc. in Electrical and Electronic Engineerings from the University of Hong Kong in 1989, and his M.Sc. in Computer Science from the University of California at Santa Barbara in 1991. Currently, he is working on his Ph.D. in Computer Science at the University of California at Santa Barbara. His research interests are in the areas of parallel and distributed systems, and distributed algorithms.
Ambuj K. Singh is an Assistant Professor in the Department of Computer Science at the University of California, Santa Barbara. He received a Ph.D. in Computer Science from the University of Texas at Austin in 1989, an M.S. in Computer Science from Iowa State University in 1984, and a B.Tech. from the Indian Institute of Technology at Kharagpur in 1982. His research interests are in the areas of adaptive resource allocation, concurrent program development, and distributed shared memory.A preliminary version of the paper appeared in the 12th Annual ACM Symposium on Principles of Distributed ComputingWork supported in part by NSF grants CCR-9008628 and CCR-9223094 相似文献
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以全国森林覆盖率最高的福建省为研究对象,利用2000~2017年夏季的MODIS EVI植被指数数据和气象与非气象因子进行协同分析,以揭示近17年福建植被的时空变化及其影响因子。结果表明:研究期内福建的EVI均值整体上升,从2000年的0.454上升至2017年的0.505,17 a间上升了11.2%,表明福建省的植被整体处于变好的状态,且在中部和西南部的变化最明显。相关分析表明,在研究期内,气象因子(气温和降水)对EVI变化的影响不显著,植被的变好主要为非气象因子的作用。EVI的提高主要得益于2003年福建省建设生态省后森林覆盖率的提高,并和2012年开始的水土流失治理有明显关系,这说明人类活动的积极作用对福建植被的变好起到了关键的作用。 相似文献
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Abstract The term 'desktop publishing' has received much media coverage in recent months in both the commercial and educational press. School-based 'desktop publishing' packages are at the moment poor imitations of full-specification systems. This paper discusses the state of desktop publishing in education today and demonstrates the weaknesses of the systems available for use in the classroom. The skills required for desktop publishing are interrelated in a complex way and cannot be presented in a hierarchical fashion. A model of the functional processes involved is suggested in the paper and analysed in terms of the skills required. 相似文献
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Toshihiro Sakamoto Nhan Van Nguyen Hiroyuki Ohno Naoki Ishitsuka Masayuki Yokozawa 《Remote sensing of environment》2006,100(1):1-16
Multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data was used to estimate the spatial distribution of heading date and rice-cropping system employed in the Mekong Delta relative to seasonal changes in water resources in 2002 and 2003. We improved a Wavelet-based Filter for determining Crop Phenology (WFCP) and developed a Wavelet-based Filter for evaluating the spatial distribution of Cropping Systems (WFCS) to the interpretation of MODIS time-series data to determine the spatial distribution of rice phenology and various rice-cropping systems from the seasonal Enhanced Vegetation Index (EVI) data. The findings correspond well the physical characteristics of the cropping system in the Mekong Delta, which have changed over time in response to localized and seasonal changes in water resources. One such example is the double-irrigated rice-cropping system commonly employed in the upper Mekong Delta in the dry season to avoid damage due to the subsequent floods. The shortage of suitable irrigation water and intrusion of saline water in the coastal regions during the dry season has constrained the practice dry-season cropping and has meant that the double- and single-rainfed rice-cropping systems are employed in the rainy season. A triple-irrigated rice-cropping system is used in the central part of the Mekong Delta which is located midway between the flood-prone and salinity intrusion areas. Analysis of annual changes in the rice cropping systems between 2002 and 2003 showed that the triple-cropped rice expanded to the flood- and salinity-intrusion areas. This expansion indicates that the implementation of measures to limit the extent of flooding and salinity intrusion by improved farming technologies and improvements in land management. The heading dates in the upper Mekong Delta in 2003 were earlier than in 2002 by approximately 20 to 30 days. The reasons for this would be due to decreased flood runoff in 2002 compared to 2001, and implementation of government policies regarding early sowing of dry-season crops. Subsequent analysis of the MODIS data confirmed that the spatial distribution of rice-cropping systems was closely related to seasonal changes in river runoff regime in the Mekong Delta. 相似文献