67 resultados para GRAPH


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分析并比较现有网络安全态势评估方法,从网络拓扑结构出发,引入图论算法和数据挖掘的聚类方法,提出一种针对分布式系统的安全态势评估方法.利用图聚类算法生成分布式系统网络连通图的聚类结果,计算拓扑完整性参考值,作为衡量分布式系统拓扑完整程度的指标,进行安全态势的量化分析.根据该方法实现低人为干预的安全态势评估原型系统,使用网络仿真工具验证了算法正确性和适用性.

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图的划分问题(GPP)是具有广泛应用背景的典型NP-难解问题,高效启发式算法一直是该领域的研究热点.作为设计启发式算法的有力工具,GPP的骨架分析存在理论分析结果匮乏、骨架规模过小等缺陷.文中采用构造偏移GPP实例的技巧,不仅在理论卜证明了获取GPP的骨架是NP-难解的,并且利用一般GPP实例与偏移实例的关系,实现了骨架规模的提高.在此基础上,文中对于目前求解GPP问题最好的算法之一的IBS进行了改进,提出了基于偏移实例的IBS算法(BI-IBS).算法BI-IBS首先构造偏移GPP实例,然后再利用局部最优解交集对它进行归约,最后再求解归约后的规模更小的新实例.实验结果表明,BI-IBS比现有算法在解的质量上有了较显著的提高.文中的工作较完善地解决了GPP的骨架研究存在的问题,所采用的构造偏移实例的技巧对于其它NP-难解问题的骨架理论分析及启发式算法设计亦具有较高的参考价值.

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When a BPEL process is executed,it is necessary to dynamically monitor the process.BPEL is a executable language,which is not suitable for visual monitoring.On the other hand,BPMN is designed to visually describe business process and is more intuitive for monitoring.To visually monitor a BPEL process, transformation from BPEL to BPMN is necessary.However,current study of transformation from BPEL to BPMN does not support the transformation of"link"activity.Besides,no work has been done to add supplementary information into BPMN during transformation.In this paper,we transform nested BPEL process into a flat BPMN process graph without hierarchy through applying a flattening strategy.Especially, we analyze various scenarios of the transformation of link activity,and provide a method to deal with it. Besides,we analyze the mapping between BPEL activities and BPMN graph,through which we found out that some supplementary information cannot automatically obtained from BPEL process.These supplementary information need to be added during transformation.At the end of this paper,we present the structure of our monitoring tool which is based on our transformation algorithm.

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数据流是为解决数字信号处理领域应用程序设计、开发难度大等问题而提出的,和传统的控制流相比,数据流能够更加自然地描述信号处理系统,更加清晰地表达系统的并发性。应用数据流设计的信号处理系统具有较高的性能,采用数据流语言能够大大加速DSP应用程序的设计和开发。同步数据流(Synchronous Data Flow,简称SDF)基于数据流,它和数据流最大的不同在于:SDF的计算单元在编译时刻消耗数据和产生数据的数目固定,这一特点决定了采用SDF设计和建立的模型能够在编译时刻确定调度序列,使得SDF适合用于多速率信号处理系统的建模。模型化多处理器系统Modex是一个面向同步数据流的可视化建模系统,它支持开发人员运用SDF进行可视化建模、为建立的模型生成调度序列、对调度序列进行空间优化、为建立的模型生成面向目标平台的C语言代码、对模型仿真验证、对模型进行资源消耗评估、将模型映射到指定的处理器执行等。 本文介绍Modex系统的两个关键技术:可视化建模和SDF调度序列空间优化的实现和研究。文章着重介绍SDF模型描述语言的定义,图元的构建和组织,图元的图形显示,控制图元的控制器,直接操作图元的命令对象,图元和视图之间的同步机制以及图形编辑器等部分的设计和实现。Modex系统的可视化建模基于GEF(Graphical Editing Framework),为同步数据流建模提供了丰富的可视化编辑操作,同时图元和视图之间松散耦合,可视化建模具有良好的互操作性以及扩展性。文章针对调度序列的空间优化提出了将SAS(Single Appearance Sequence)和非SAS类型调度序列相结合的思想,并基于该思想设计了生成空间优化的非SAS类型调度序列算法IAO(Increase Available Output),并结合EA(Evolutionary Approach)算法实现了面向通用,特别是存在反馈环的SDF模型的空间优化方案SGUTS(Solution for General Graph Using Two Kinds of Sequences)。SGUTS是一个层次化的优化框架,它通过聚集将一个存在反馈的模型分为上层模型和下层模型,然后采用EA、IAO算法分别为这两层模型进行优化,从而得到整个模型的优化结果。SGUTS不仅解决了存在反馈环的SDF模型空间优化问题,而且相比较其他算法,SGUTS取得了较好的优化结果。

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A highly sensitive microstructured polymer optical fiber (MPOF) probe for hydrogen peroxide was made by forming a rhodamine 6G-doped titanium dioxide film on the side walls of array holes in an MPOF. It was found that hydrogen peroxide only has a response to the MPOF probe in a certain concentration of potassium iodide in sulfuric acid solution. The calibration graph of fluorescence intensity versus hydrogen peroxide concentration is linear in the range of 1.6 x 10(-7) mol/L to 9.6 x 10(-5) mol/L. The method, with high sensitivity and a wide linear range, has been applied to the determination of trace amounts of hydrogen peroxide in a few real samples, such as rain water and contact lens disinfectant, with satisfactory results.

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A novel microstructured polymer optical fiber (MPOF) probe for nitrites (NO(2)(-)) detection was made by forming rhodamine 6G (Rh 6G)-doped cellulose acetate (CA) on the side wall of array holes in a MPOF It was found that the MPOF probe only have a response to nitrites in a certain concentration of sulfuric acid solution The calibration graph of fluorescence intensity versus nitrites concentration was linear in the range of 2.0 x 10(-4) g/ml-5.0 x 10(-3) g/ml. The method possesses case of chemical modification, low cost design, and potential for direct integration with existing instrumentation, and has been applied to the determination of nitrites in real samples with satisfactory results. (C) 2010 Elsevier B.V. All rights reserved

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青稞(Hordeum vulgare L.var.nudum Hook.f.),即裸大麦,是兼食用、饲用和酿造于一体的作物,有着重要的利用价值。淀粉是青稞籽粒中含量最多、最重要的碳水化合物,淀粉含量、直支淀粉比将会直接影响淀粉的功能特性,进而影响淀粉的应用领域。我国青藏高原青稞的栽培和食用历史悠久,特色青稞资源极其丰富。目前关于青藏高原青稞淀粉特性的报道还不多见,筛选和培育特色淀粉青稞利于拓展青稞的应用领域, 从而提高其经济价值。 本研究以114份青藏高原青稞品种(系)为实验材料,通过SDS-PAGE对材料的胚乳淀粉颗粒结合蛋白(SGAPs)进行分离,确定各蛋白的分子量大小、组合类型和多态性等。然后按照国标法测试材料的籽粒总淀粉含量和直链淀粉含量,通过微型糊化粘度仪分析相应的淀粉糊化特性,最后使用显微镜观察比较了青稞的淀粉颗粒形态特征。主要结果如下: 1、114种青稞中共分离出20种不同的SGAP条带,条带分子量为35.00~112.39 KDa,分布频率为12.28~97.37%。材料含有的SGAPs条带数从10到14不等,超过一半的材料含11种SGAP条带。20种条带形成16种组合类型,其中西藏地区青稞包含所有16个组合类型,四川地区青稞包含其中12个组合类型。青藏高原青稞籽粒淀粉颗粒结合蛋白的差异很大,遗传多样性丰富。 2、114份青稞的总淀粉含量、直链淀粉含量、直支淀粉比、峰值粘度、糊化温度和峰值温度的变幅分别为51.26~66.70%、14.64~29.74%、0.17~0.42、194~1135BU、58.8~65.2℃和81.4~92.4℃,相应的平均值分别为59.82%、23.60%、0.31、722.30BU、62.1℃和88.8℃。群体在总淀粉含量、直链淀粉含量、直支淀粉比、峰值粘度、糊化温度和峰值温度上的分布具有明显的正态性;所有胚乳淀粉体的淀粉粒都呈复粒结构。对西藏和四川的材料进行了分组比较, 两地区的青稞在直链淀粉含量和直支淀粉比上的差异达到显著水平。 3、筛选出18份具有特殊淀粉特性的青稞品种,其中5份材料的总淀粉含量超过65%,包括NB63-1、NB67、甘孜白六棱、98221-1和NB63;3份材料的直链淀粉含量大于29%,包括藏青85、藏青3号和喜马拉6号;8份材料的直支淀粉比小于0.25,包括99033-6、春青稞、阿坝330、Jan-03、米麦114、396、NB63-1和92013;7份材料的糊化温度低于60℃,同时材料的峰值粘度大于1000BU,并且峰值温度低于90℃,包括足捉春、Jan-03、阿坝330、米麦114、春青稞、20003和阿青5号。 4、各淀粉特性间存在高度相关性。直链淀粉含量和直支淀粉比与糊化温度成极显著正相关,与峰值粘度成极显著负相关,与A型淀粉粒数量和大小呈负相关。不同SGAPs组合的品种之间,淀粉含量和淀粉糊化特性间差异均达显著水平。SGAP2、SGAP5、SGAP6和SGAP7可能对籽粒直链淀粉含量、直支淀粉比和糊化温度有正向效应;SGAP3、SGAP9∼SGAP20可能对峰值粘度有正向效应。 本研究对青藏高原青稞淀粉资源进行了较为全面的评价,对该区青稞淀粉特性有了系统的认识。研究筛选出的特殊青稞品种可作为青稞育种和青稞淀粉工业应用的潜在资源,淀粉特性差异巨大的众多青稞品种也为拓宽青稞应用领域提供了丰富的资源保障。本研究对部分SGAPs在性质上的鉴定和功能上的初步推断为青稞材料的筛选提供了指导,也为品质育种提供了理论参考。 Hulless barley (naked barley, Hordeum vulgare L.) is a short- season, early maturing crop with a wide range of adaptation. It has been attracting more and more attention due to its superior nutrition and extensive industrial applications. Starch is the main ingredient in hulless barley seeds which makes up 65 percent of hulless barley’s dry weight. The ratio of the amylose/amylopectin and the size, shape, distribution of starch granules can affect the physico-chemical and functional properties of starch, which may turn affect its utilizations. The Qinghai-Tibet Plateau, which is located in southwestern China, is a typical area of vertical agricultural ecosystem and one of the barley origin centers with abundant hulless barley resources. There are little reports about hulless barley in Qinghai-Tibet Plateau at present. To screen and cultivate some characteristic hulless barley can improve its value. An improved SDS-PAGE was used to identify SGAPs combination of 114 hulless barley varieties. Starch content (total starch and amylose starch) was determined according to the standard methods GB5006-85 and GB/T 15683 using PerkinElmer M341 Precision Automatic Polarimeter and UV spectrophotometer 755B respectively. The pasting properties were measured by BRABENDER Micrio Visco-Amylo- Graph 803201. The morphology of starch granules were observed and compared with Axioplan 2 Imaging light microscopy. The following were the results obtained: 1. There were 20 major SGAPs presented in 114 varieties, with the molecular weight ranged from 35.00 to 112.39 KDa, and the frequencies ranged from 12.28% to 97.37%. The number of SGAP bands in each accession varied from 10 to 14, more than half of the population had 11 bands. There were 16 distinct SGAP patterns in the 114 varieties, the Tibet hulless barley had all of the 16 types and the Sichuan hulless barley had 12 types. The results indicated the Qinghai-Tibet Plateau hulless barley had a polymorphism of the SGAPs. 2. The ranges of the total starch content, amylose content, Am/Ap, peak viscosity, pasting temperature and peak temperature of the 114 hulless barley were 51.26~66.70%,14.64~29.74%,0.17~0.42,194~1135BU,58.8~65.2 and 81.4℃~92.4, with an average of ℃59.82%, 23.60%, 0.31, 722.30BU, 62.1 and 88.8,℃℃ respectively. The distributions of the total starch content, amylose content, Am/Ap, peak viscosity, pasting temperature and peak temperature were visibly normal school. All of the amyloplasts in endosperm of varieties showed bimodal size distributions.The main starch properties of hulless barley from Tibet and Sichuan were separated and compared, the differences on amylose content and Am/Ap were obvious. 3. Eighteen accessions which had special starch properties were screened out. Five accessions with total starch content beyond 65%, including NB63-1, NB67, Ganzibailiuleng, 98221-1 and NB63; three accessions, Zangqing85, Zangqing3 and Ximala6, with the highest amylose content (>29%); five accessions with Am/Ap less than 0.25, including 99033-6, Chun Qingke, A Ba 330, Jan-03, Mi Mai114, 396, NB63-1 and 92013; seven accessions had a pasting temperature under 60, ℃meanwhile their peak viscosity beyond 1000BU and their peak temperature under 90℃,including Zu Cuochun, Jan-03, A Ba 330, Mi Mai 114, Chun Qingke, 20003 and A Qing 5. 4. There were high correlations between starch properties. Amylose content and Am/Ap were positively correlated to pasting temperature, negatively correlated to peak viscosity, negatively correlated to the number and granule size of A-type granule. Different SGAP combinations caused significant diversities in starch content and pasting properties. SGAP2, SGAP5, SGAP6 and SGAP7 may have positive effect on amylose content, Am/Ap and pasting temperature; SGAP3, SGAP9∼SGAP20 may have positive effect on peak viscosity. Our research made a comprehensive evaluation on the hulless barley starch from the Qinghai-Tibet Plateau, we can get a systemic understanding. Some special accessions were screened out can be used on the hulless barley breeding lines and industries utilization.The combination of the SGAPs may become a criterion to evaluate the hulless barley endosperm starch quality. Consequently, the results will be good information for further studies on the hulless barley.

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In this paper, we revisit the issue of the public goods game (PGG) on a heterogeneous graph. By introducing a new effective topology parameter, 'degree grads' phi, we clearly classify the agents into three kinds, namely, C-0, C-1, and D. The mechanism for the heterogeneous topology promoting cooperation is discussed in detail from the perspective of C0C1D, which reflects the fact that the unreasoning imitation behaviour of C-1 agents, who are 'cheated' by the well-paid C-0 agents inhabiting special positions, stabilizes the formation of the cooperation community. The analytical and simulation results for certain parameters are found to coincide well with each other. The C0C1D case provides a picture of the actual behaviours in real society and thus is potentially of interest.

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数据是地理信息系统 (GIS)应用的核心。现实世界的数据具有普遍的多样性 ,关于 GIS接受不同数据的研究已成为当前 GIS研究中的一个难点和热点。本文根据通用 GIS工具软件 ARC/INFO接受外部空间数据的方式和图形分析软件 Surfer的数据格式特征 ,运用特定的处理方法实现了由 Surfer格式数据向 ARC/ INFO矢量格式数据 (Coverage)的转换 ,使 ARC/ INFO接受外部数据格式的范围拓宽 ,数据处理能力增强。

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针对目前TCG组织定义的远程证明信任链模型在描述基于属性的远程证明时存在的不足,通过对基于属性远程证明过程中的证明请求、可信策略以及可信性评估过程进行抽象,提出了一个新的基于属性的远程证明模型。该模型将传统远程证明中信任链模型扩展为信任图,使得模型能够表达更为灵活的可信策略。还对可信策略的属性可信性判定问题以及可信评估过程终止性问题进行了讨论,给出了相关定理及证明,为可信策略的定义与检查提供了理论基础。基于该模型给出了实现可信网络接入时的可信策略定义,用实例验证了该模型在描述能力方面的增强。

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IEEE Comp Soc, IFIP, Tianjin Normal Univ

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Feature-based image watermarking schemes, which aim to survive various geometric distortions, have attracted great attention in recent years. Existing schemes have shown robustness against rotation, scaling, and translation, but few are resistant to cropping, nonisotropic scaling, random bending attacks (RBAs), and affine transformations. Seo and Yoo present a geometrically invariant image watermarking based on affine covariant regions (ACRs) that provide a certain degree of robustness. To further enhance the robustness, we propose a new image watermarking scheme on the basis of Seo's work, which is insensitive to geometric distortions as well as common image processing operations. Our scheme is mainly composed of three components: 1) feature selection procedure based on graph theoretical clustering algorithm is applied to obtain a set of stable and nonoverlapped ACRs; 2) for each chosen ACR, local normalization, and orientation alignment are performed to generate a geometrically invariant region, which can obviously improve the robustness of the proposed watermarking scheme; and 3) in order to prevent the degradation in image quality caused by the normalization and inverse normalization, indirect inverse normalization is adopted to achieve a good compromise between the imperceptibility and robustness. Experiments are carried out on an image set of 100 images collected from Internet, and the preliminary results demonstrate that the developed method improves the performance over some representative image watermarking approaches in terms of robustness.

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Polyaniline-camphorsulfonic acid (PAN-CSA) composite film on platinum electrode surface has been synthesized via the electrochemical polymerization of aniline in the presence of camphorsulfonic acid (CSA). It was found that the doping of polyaniline (PAN) with CSA extends the electroactivity of PAN in neutral and even in alkaline media. The PAN-CSA composite film coated platinum electrodes are shown to be good electrocatalytic surfaces for the oxidation of ascorbic acid (AA) in phosphate buffer solution (PBS) of pH 7.0. The anodic peak potential of AA shifts from 0.63 V at the bare platinum electrode to 0.34 V at the PAN-CSA composite modified platinum electrode with a greatly enhanced current response. A linear calibration graph is obtained over the AA concentration range of 5-50 mM using cyclic voltammetry. The kinetics of the catalytic reaction are investigated using rotating disk electrode voltammetry and chronoamperometry. The results are explained using the theory of electrocatalytic reactions at chemically modified electrodes. The PAN-CSA composite on the electrode surface shows good reproducibility and stability.