基于GRA-SPA的城市地下综合管廊PPP项目风险评价研究

为及时发现并合理应对综合管廊PPP项目存在的风险,给政府部门提供投资决策的依据,提出基于集对分析理论的风险评价方法。首先,借助德尔菲法确定初始风险清单,采用主成分分析（PCA）对25个要素指标降维处理,并结合以往研究文献及项目特点构建管廊PPP项目风险评价指标体系; 其次,引入C-OWA算子实现指标赋权,削弱数据极端值造成的不利影响,并建立基于集对分析的风险评价模型,利用灰色关联度确定差异度系数i值,通过联系度的取值评判项目风险等级及发展趋势; 最后,将模型应用到青岛高新区管廊PPP项目实际工程,结果表明该项目风险等级为“中等”,有向较低风险等级发展的趋势,同时验证模型具有可行性与合理性,为综合管廊PPP项目风险评价的理论与实践提供参考。     

Some Properties of Periodogram of Autoregressive Integrated Moving Average Process

Based on the analysis of periodogram, this paper discussed the properties of periodogram of autoregressive integrated moving average process ARIMA(p,1,q), and found that the periodgram of ARIMA(p,1,q) process is dominated by the transfer function of the difference operator, which is the same as the result of Crato. The obtained asymptotically properties of the single random walk process was extended to more complicated autoregressive integrated moving average process.     

危岩变形的灰色预测方法及应用

危岩是山区常见的地质病害之一,危岩变形监测预测是危岩防灾减灾的重要基础。将灰色预测理论应用于危岩变形监测,建立了危岩变形灰色预测模型及残差修正灰色预测模型。以重庆南川甑子危岩为例,以实测危岩累计位移值为原始数据,建立了GM(1,1)灰色预测模型及残差修正预测模型。经精度检验,小误差频率P=1,后验差比值C=0.160243,模型精度等级达到较高水平,比常规危岩预测方法更具有可靠度。     

A new black box analysis of hash functions based on block ciphers

For the 64 most basic ways to construct a hash function H:{0,1} → {0,1}n from a block cipher E:{0,1}n × {0,1}n → {0,1}n, Black et al.provided a formal and quantitative treatment of the 64 constructions, and proved that 20 schemes are collision resistant.This paper improves the upper and lower bounds and make contrast with a hash constructed from a random oracle.These 20 schemes have only one kind of collision resistance upper and lower bounds.In addition, we present new advantages for finding second preimages.     

Automatic artist recognition of songs for advanced retrieval

Automatic recognition of artists is very important in acoustic music indexing, browsing, and contentbased acoustic music retrieving, but synchronously it is still a challenging errand to extract the most representative and salient attributes to depict diversiform artists. In this paper, we developed a novel system to complete the reorganization of artist automatically. The proposed system can efficiently identify the artist's voice of a raw song by analyzing substantive features extracted from both pure music and singing song mixed with accompanying music. The experiments on different genres of songs illustrate that the proposed system is possible.     

Probability-based clustering and its application to WLAN location estimation

Wireless local area networks (WLAN) localization based on received signal strength is becoming an important enabler of location based services. Limited efficiency and accuracy are disadvantages to the deterministic location estimation techniques. The probabilistic techniques show their good accuracy but cost more computation overhead. A Gaussian mixture model based on clustering technique was presented to improve location determination efficiency. The proposed clustering algorithm reduces the number of candidate locations from the whole area to a cluster. Within a cluster, an improved nearest neighbor algorithm was used to estimate user location using signal strength from more access points. Experiments show that the location estimation time is greatly decreased while high accuracy can still be achieved.     

基于模糊神经网络的GM（1，1）模型

在分析GM（1,1）模型建模机理的基础上,提出GM（1,1）模型中参数a,b的一种新算法一模糊神经网络算法,把模糊神经网络应用于灰色系统GM（1,1）模型的建模过程,得到模糊神经网络GM（1,1）模型,并将其运用于民航客运量的预测,结果表明改进后的模型有较好的拟合及预测精度。     

从构建和谐教育浅析体育教师评价的价值取向

社会主义和谐社会是人性健全、追求卓越的社会,其核心是民生．学校是人生观、世界观、价值观的奠基之地,是民生之基．构建和谐教育需要打造一支高素质的教师队伍,使教师队伍首先实现自身的和谐．我们所要建立的体育教师评价其价值取向应是在构建和谐社会总体目标指导下,坚持以人为本、实现教育全面发展、保障师生创造活力得到充分发挥的评价;是把各方面利益关系不断得到有效协调、最能体现和谐的公平和正义作为核心价值取向的评价,其根本着眼点在于实现人的全面发展．评价不仅需要达到教育结构的优化,更需要达到体育教师个体素质的提高目标,因此,我们必须要坚持用改革的办法和发展的思路解决体育教师评价中价值取向的矛盾和问题．     

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在北京市实施公交改革、推动公共交通发展的背景下,以对北京市2006年初的地面公共交通线网评价为基础,应用地理信息系统技术,选取线路长度、线路网密度、线路重复系数、非直线系数、站点密度、平均站距、站点覆盖率等指标,对截至2007年8月已完成的五批大规模地面公交线网调整方案的效果进行了分析,明确了目前地面公共交通线网的总体特征和存在问题,为进一步实施公交线网优化方案、提高公交运行效率提供参考。     

腭穹隆形态对无牙上颌应力分布的三维有限元分析

目的研究腭穹隆形态对无牙上颌应力分布的影响。方法模拟五种咬合状态,对尖、平、凹三种腭穹隆形态无牙上颌的三维有限元模型进行加载。结果在五种加载条件下,三种腭穹隆形态无牙上颌的唇系带切迹区及牙槽嵴顶区为压应力集中区。在所有加载方式下,凹型腭穹隆形态无牙上颌的唇系带切迹区、上腭区及牙槽嵴顶区压应力峰值均高于平型,尖型最低。结论腭穹隆形态对无牙上颌的压应力分布状况无明显影响,对各压应力区应力值大小有影响;无牙上颌压应力的分布及大小与加载方式有关。