R-型聚类中基于Gamma-test的一种新度量

对R-型聚类分析的度量进行了研究,提出了一种基于Gamma-test理论的新度量.给出了新度量的5种不同定义方式,对各定义的性质进行了讨论.并将其应用于经典的系统聚类法,对所得的聚类结果与用相关系数作为度量所得的结果进行比较,分析了各定义的优劣,得出了最有效的新度量定义.

叶在扬对中西度量衡的研究与清末度量衡的改制——以《度量衡新议》为中心

清末度政混乱,对国家经济、社会发展诸方面造成很大阻碍。随着新政的陆续出台,清政府颁布《度量权衡画一制度图说总表推行章程》。在此之前,学者对度量衡划一呼声虽高,但少有系统研究中西度量衡的著作,晚清学者叶在扬所著《度量衡新议》是唯一的一部研究专著。该书在对中西度量衡对比研究的基础上,重新探讨了度量衡基准,拟定和设计了度量权衡单位、器具,具有一定的创新性和探索价值。文章对叶在扬的相关工作进行了梳理和考证,详细分析其拟定度量衡新制的数理原理及其合理性与实效性不足的弊端;对其工作在清末度量衡改制中产生的影响进行了探讨,指出1908年清廷颁布的《度量权衡画一制度图说总表推行章程》直接参考了叶在扬的《度量衡新议》,并推测叶在扬本人也可能参与了章程的起草。

Vague集(值)之间的新相似度量

提出Vague集(值)之间的新相似度量,给出一个区间值数据向Vague值数据的转化公式。农业领域的应用实例进一步表明这些公式是实用的。

椭圆定形曲线拟合问题若干新型算法

针对一类特殊的参数辨识问题——椭圆定形曲线拟合问题 ,对原有的几何距离法提出了进化算法的求解方案 .基于反问题的求解思想给出了一种新的椭圆拟合度量 ,和原有度量相比 ,它既反映了拟合曲线的弯曲特性又便于数值求解 ,在该度量基础上构造出一种新型算法——加权新度量法 .数值模拟结果表明 ,提出的新方法是有效的。

小学阶段“对顶角相等”的教学思考——以四年级上册“角的度量”相关习题为例

＂对顶角相等＂本是九年义务教育阶段人教版教材七年级下册的内容,拿出来放在这里讨论,可能相当一部分老师会很诧异,觉得小学阶段不可能有。我们不妨来对小学数学人教实验版（2001）教材和人教2011版教材的这一单元做一对比。通过对比,教师可以发现两种教材都有这种题型,而且修订完善后的人教2011版教材在已有的基础上延伸地保留了它,可见这种题型在新课程中所占的地位。那在实际的教学中如何讲解呢？

椭圆拟合算法在表面形貌测量中的应用

本文研究了椭圆曲线拟合的各种方法。从拟合质量、计算复杂度等方面,对每种拟合方法进行了分析和对比,并且分别对基于像散法的光探针式表面形貌测量系统图像中的椭圆进行曲线拟合,从中确定出最适合的拟合方法-加权新度量法。实验与仿真结果表明,用该拟合方法确定椭圆参数是可行的,逼近效果较好且具有较强的抗噪性。

90年代度量贸易开放度的新方法及其启示

长期以来 ,怎样度量贸易开放度 ,国内外一直存在不同的看法。本文在介绍和归纳了战后各种度量方法的基础上 ,重点就 2 0世纪 90年代以来国外贸易开放度度量方法的最新进展作了系统和深入的分析 ;然后根据上述新进展所折射出的政策含义 ,结合当前我国贸易开放实践 。

基于QPSO的数据聚类及在图像颜色分割中的应用

聚类算法在数据分析、数据挖掘等许多地方有广泛的应用,探索了基于QPSO的数据聚类及其在图像分割中的应用,提出了一种新的距离度量的聚类算法,在分析PSO聚类算法的基础上提出了QPSO聚类算法,给出了相应的实验结果和算法讨论。

基于QPSO数据聚类的图像颜色分割

聚类算法在数据分析及数据挖掘等许多领域有广泛应用,在聚类方法中引入一种新的距离度量标准替代传统的Eu-clidean距离度量标准以提高其健壮性,并在此基础上提出基于粒子群算法(Particle Swarm Optimization,简称PSO)的聚类方法和基于量子行为的微粒群优化算法(Quantum-behaved Particle Swarm Optimization,简称QPSO)的聚类方法,然后将两种聚类方法应用于图像分割。实验结果表明,基于QPSO的聚类方法性能优于基于PSO的聚类方法。

基于量子行为的微粒群优化算法的数据聚类

在PSO聚类算法的基础上,提出了基于量子行为的微粒群优化算法(QPSO)的数据聚类。QPSO算法不仅参数个数少、随机性强,并且能覆盖所有解空间,保证算法的全局收敛。PSO与QPSO算法的不同在于聚类中心的进化上,实验中用到四个数据集比较的结果,证明了QPSO优于PSO聚类方法。在聚类过程中使用了一种新的度量代替Euclidean标准,实验证明了新的度量方法比Euclidean标准更具有健壮性,聚类的结果更精确。

基于Kalman滤波和改进的Mean Shift算法的目标跟踪

Mean Shift算法因为简单性和稳定性在目标跟踪中得到广泛应用,但是当目标和背景的颜色模型比较接近时,传统的Mean Shift算法由于缺少空间信息,且经典的相似性度量函数不易区别,导致跟踪失败。为了克服上述缺点,采用基于空间颜色特征和新的相似性度量的Mean Shift算法,并提出一种融合Kalman滤波器和改进的Mean Shift算法的目标跟踪方法。首先,利用改进的Mean Shift算法计算出当前帧中目标的准确位置,然后使用Kalman滤波器去预测下一个初始搜索位置,用于下一帧中Mean Shift迭代,最后实现对目标的跟踪。实验结果表明,该算法可以准确地跟踪目标,并且跟踪的准确率优于传统的Mean Shift算法或者Kalman和传统Mean shift的融合算法。

Olfactory ensheathing cells promote nerve regeneration and functional recovery after facial nerve defects

Olfactory ensheathing cells from the olfactory bulb and olfactory mucosa have been tbund to increase axonal sprouting and pathfinding and promote the recovery of vibrissae motor performance in facial nerve transection injured rats. However, it is not yet clear whether olfactory ensheathing cells promote the reparation of facial nerve defects in rats. In this study, a collagen sponge and silicone tube neural conduit was implanted into the 6-mm defect of the buccal branch of the facial nerve in adult rats. Olfactory ensheathing cells isolated from the olfactory bulb of newborn Sprague-Dawley rats were injected into the neural conduits connecting the ends of tile broken nerves, the morphology and function of the regenerated nerves were compared between the rats implanted with olfactory ensheathing cells with the rats injected with saline. Facial paralysis was assessed. Nerve electrography was used to measure facial nerve-induced action potentials. Visual inspection, anatomical microscopy and hematoxylin-eosin staining were used to assess the histomorphology around the trans planted neural conduit and the morphology of the regenerated nerve. Using fluorogold retrograde tracing, toluidine blue staining and lead uranyl acetate staining, we also measured the number of neurons in the anterior exterior lateral f：acial nerve motor nucleus, the number of myelinated nerve fibers, and nerve fiber diameter and myelin sheath thickness, respectively. After surgery, olfactory ensheathing cells de- creased facial paralysis and the latency of the facial nerve-induced action potentials. There were no differences in the general morphology of the regenerating nerves between the rats implanted with olfactory ensheathing cells and the rats injected with saline. Between-group results showed that olfactory ensheathing cell treatment increased the number of regenerated neurons, improved nerve fiber morphology, and increased the number of myelinated nerve fibers, nerve fiber diameter, and myelin sheath thickness. In conclusion, implantation of olfactory ensheathing cells can promote regeneration and functional recovery after facial nerve damage in rats.

Performance of Inner-core Supersonic Gas Separation Device with Droplet Enlargement Method

To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a method of droplet enlargement was applied. A series of experiments were carried out in the improved separation device under various conditions, using air-ethanol vapor as the medium and micro water droplets as nucleation cen- ters. The effects of the inlet pressure, temperature and relative humidity, the swirling intensity, and mass flow rate of water on the separation performance were investigated. The separation was improved by increasing the inlet pressure and relative humidity. With the decrease of swirling intensity and mass flow rate of water, the separation efficiency increased first and then decreased. The inlet temperature had a slight effect on the separation. The results showed that the separation performance was effectively improved using the proposed structure and method, and the best separation in this study was obtained with the ethanol removal rate about 55% and dew point depression 27 K. The addition of water had little pollution to the air-ethanol vapor system since the water carry-over rate was within the range of -2 %-0 in most cases.

Influence of moisture content on shearing strength of unsaturated undisturbed quaternary system middle pleistocene

The unsaturated undisturbed quaternary system middle pleistocene loess,a typical unsaturated soil,often occurs in the implementation of western development strategy.To obtain the shearing strength characteristics of this unsaturated undisturbed loess,based on the analysis of mineral composition,the triaxial shear test of undisturbed quaternary system middle pleistocene loess under different moisture contents is conducted with the specialized triaxial instrument for unsaturated soil.The test results show that the mainly mineral composition of undisturbed quaternary system middle pleistocene loess is quartz and albite.Under the same confining pressure,the matric suction increases with the decrease of moisture content.The smaller the moisture content,the larger the matric suction;the higher the moisture content,the lower the matric suction.Under the same moisture content,the matric suction increases with the confining pressure and reaches a maximum when the confining pressure is 100 kPa,and then decreases with the increase of confining pressure.This phenomenon is closely related to the grain contact tightness of soil mass under high confining pressure.According to the triaxial test of loess,the sample of loess experiences 4 stages from loading to failure:1) compaction stage;2) compression stage;3) microcrack developing stage;4) shear failure stage.The test sample is of brittle failure(weak softening)under low moisture content and confining pressure.With the decrease of matric suction and the increase of consolidated confining pressure,the stress-strain curve changes from softening type to ideal plastic type.In the shearing strength parameters of unsaturated undisturbed loess,the influence of moisture content on internal friction angle is small,but that on cohesive force is obvious.Therefore,the shearing strength of unsaturated undisturbed loess is higher than that of saturated undisturbed loess and varies with the moisture content.

Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years

Previous studies carried out in the East China Sea （ECS） mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon （EAWM）. The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size （Mz） of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River （DTSD）. Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment.

Finite element model updating for large span spatial steel structure considering uncertainties

In order to establish the baseline finite element model for structural health monitoring,a new method of model updating was proposed after analyzing the uncertainties of measured data and the error of finite element model.In the new method,the finite element model was replaced by the multi-output support vector regression machine(MSVR).The interval variables of the measured frequency were sampled by Latin hypercube sampling method.The samples of frequency were regarded as the inputs of the trained MSVR.The outputs of MSVR were the target values of design parameters.The steel structure of National Aquatic Center for Beijing Olympic Games was introduced as a case for finite element model updating.The results show that the proposed method can avoid solving the problem of complicated calculation.Both the estimated values and associated uncertainties of the structure parameters can be obtained by the method.The static and dynamic characteristics of the updated finite element model are in good agreement with the measured data.

Innovate Project Supervision System for Higher Engineering Construction Quality

With rapid development of PetroChina＇s Qinghai Oilfield, engineering construction quality becomes more and more important in infrastructure construction of the oilfield. Generally speaking, engineering construction quality is related both to national economic development and safety of people and assets. To turn a design map into a materialized object, the construction project involves a large number of elements, such as design, materials, machinery, landform, geological factors, meteorological factors, construction process, technological measures and supervision system. Therefore, quality control holds the key to a construction project.

Comparing the VGCG model as the unification of dark sectors with observations

Current observations indicate that 95% of the energy density in the universe is the unknown dark component.The dark component is considered composed of two fluids:dark matter and dark energy.Or it is a mixture of these two dark components,i.e.,one can consider it an exotic unknown dark fluid.With this consideration,the variable generalized Chaplygin gas(VGCG)model is studied with not dividing the unknown fluid into dark matter and dark energy parts in this paper.By using the Markov Chain Monte Carlo method,the VGCG model as the unification of dark sectors is constrained,and the constraint results on the VGCG model parameters are,n=0.00057+0.0001+0.0009-0.0006-0.0006,α=0.0015+0.0003+0.0017-0.0015-0.0015and B s=0.778+0.016+0.030-0.016-0.035,obtained by the cosmic microwave background data from the 7-year WMAP full data points,the baryon acoustic oscillation data from Sloan Digital Sky Survey(SDSS)and 2-degree Field Galaxy Redshift(2dFGRS)survey,and the Union2 type Ia supernova data with systematic errors.At last,according to the evolution of deceleration parameter it is shown that an expanded universe from deceleration to acceleration can be obtained in VGCG cosmology.

Highly densified carbon electrode materials towards practical supercapacitor devices

Supercapacitors are expected to bridge the gap between conventional electrostatic capacitors and batteries, but have not found significant application in primary energy devices, partly due to some unsolved problems in the elec- trode materials. A wide range of novel materials such as novel carbons have been investigated to increase the energy den- sity of the electrodes and the volumetric merits of the materi- als need to be specifically considered and evaluated, towards the practical application of these novel materials. In obser- vation of the intense research activity to improve the volu- metric performance of carbon electrodes, the density or mass loading is particularly important and shall be further opti- mized, both for commercially applied activated carbons and in novel carbon electrode materials such as graphene. In this review, we presented a brief overview of the recent progress in improving the volumetric performance of carbon-based su- percapacitor electrodes, particularly highlighting the devel- opment of densified electrodes by various technical strategies including the controlled assembly of carbon building blocks, developing carbon based hybrid composites and constructing micro- supercapacitors.

Latitudinal and climatic distributions of 3D craniofacial features among Holocene populations

The geographical and climatic patterning in craniofacial morphology among recent hominids has been regarded as relatively reliable evidence of environmental adaptation and natural selection,which is largely attributed to thermoregulation.However,the relative influence of genetic and environmental factors on craniofacial features is unclear.Our study employed 3D laser scanning techniques to evaluate the association between geographical(latitude),climatic(annual temperature)factors,and 3D craniofacial measurements in 18 recent populations through bivariate correlation analysis.Significant correlations were found among braincase surface area,zygomatic bone surface area,cranial-facial index(facial surface area relative to braincase surface area)and local temperature,and a clear latitudinal gradient was also found in variation of braincase surface area.No significant correlations were found between zygomatic bone surface area,cranial-facial index and latitude.Our analysis supports the idea that the braincase functions as a radiator and is closely related to direct sunlight.We also suggest that absolute/relative craniofacial surface area varies consistently with predictions derived from Bergmann’s Rule.The mosaic craniofacial traits of American Indians may reflect retention of cold-derived,ancestral features,as well as a response to a slightly warmer climate.Because different craniofacial regions preserve environmental/genetic signatures differentially,caution is suggested when craniofacial anatomy is used for phylogenetic reconstruction and functional-morphological analysis.