基于小波变换和时间序列的网络流量预测模型

随着互联网规模和应用的扩大,网络数据流量呈现出复杂多分形性的特点,针对这个特性,构建了基于小波分析和ARMA模型的网络流量预测模型,用Mallat算法将原始流量数据分解为4个分层数据,对各层数据用ARMA模型进行预测,再将各层预测数据重组为预测的网络流量.采用真实数据进行仿真的试验表明,基于小波分析和ARMA相结合的网络流量预测模型的预测结果具有较高的准确度,并在网络管理和优化中具有重要实用价值.

Elastic envelope inversion using multicomponent seismic data with filtered-out low frequencies

The absence of low-frequency information in seismic data is one of the most difficult problems in elastic full waveform inversion. Without low-frequency data, it is difficult to recover the long-wavelength components of subsurface models and the inversion converges to local minima. To solve this problem, the elastic envelope inversion method is introduced. Based on the elastic envelope operator that is capable of retrieving low- frequency signals hidden in multicomponent data, the proposed method uses the envelope of multicomponent seismic signals to construct a misfit function and then recover the long- wavelength components of the subsurface model. Numerical tests verify that the elastic envelope method reduces the inversion nonlinearity and provides better starting models for the subsequent conventional elastic full waveform inversion and elastic depth migration, even when low frequencies are missing in multicomponent data and the starting model is far from the true model. Numerical tests also suggest that the proposed method is more effective in reconstructing the long-wavelength components of the S-wave velocity model. The inversion of synthetic data based on the Marmousi-2 model shows that the resolution of conventional elastic full waveform inversion improves after using the starting model obtained using the elastic envelope method. Finally, the limitations of the elastic envelope inversion method are discussed.

Long memory of price-volume correlation in metal futures market based on fractal features

An empirical test on long memory between price and trading volume of China metals futures market was given with MF-DCCA method. The empirical results show that long memory feature with a certain period exists in price-volume correlation and a fittther proof was given by analyzing the source of multifractal feature. The empirical results suggest that it is of important practical significance to bring the fractal market theory and other nonlinear theory into the analysis and explanation of the behavior in metal futures market.

Morphological Diversity Analysis of Red-seed Watermelon (Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao) Germplasm Resources

[Objective] This study aimed to analyze the morphological diversity of red- seed watermelon （Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao） germplasm resources. [Method] Multiple cluster analysis and principal components analysis on the morphological traits of 51 red-seed watermelon germplasm resources were carried out. [Result] The coefficient of variations （CVs） of 39 morphological traits in 51 red-seed watermelon idioplasm resources ranged from 5.37% to 66.95%, with an average of 22.87%. The average of Shannon diversity information indices was 1.55. Among them, the Shannon diversity information index of seed length was the highest （2.16） and that of seed shell figure pattern was the lowest （0.32）. In ad- dition, the morphological diversity information indices of quantity characters were higher than that of quality characters. The principal components analysis revealed that the variance contribution rates of the first, second and third principal compo- nents were 19.49%, 15.32% and 9.55%, respectively. Cluster analysis divided the 51 materials into three broad branches based on the morphological traits. There was only one material in the fist branch and two in the second branch, and all the three materials were wild. The other 48 materials were divided into the third branch and all of them were cultivars. [Conclusion] This study provided a theoretical basis for the protection and utilization of red-seed watermelon resources.

Investigation of Dynamic Behavior in 1D Non-uniform Granular System

We present a non-uniform granular system in one-dimensional case, whose granularity distribution has the fractal characteristic. The particles are subject to inelastic mutual collisions and obey Langevin equation between collisions. By Monte Carlo simulation we study the dynamic actions of the system. Far from the equilibrium, i.e., τ 〉〉 τe, the results of simulation indicate that the inhomogeneity of the system and the inelasticity of the particles have great influences on the dynamic properties of the system, and correspondingly the influence of the inhomogeneity is more significant.

Hawk mimicry and the evolution of polymorphic cuckoos

The resemblance of some parasitic cuckoos to Accipiter hawks has been known since ancient times. Recent experiments show that the hawk-like features of Common Cuckoos (Cuculus canorus) facilitate access to Reed Warbler (Acrocephalus scirpaceus) host nests. However, social information alerts hosts to see through the cuckoo’s mimetic disguise. In turn, this has promoted the evolution of a cuckoo polymorphism to thwart host recognition. Here we show by comparative analyses that parasitic cuckoos with hawk-like features (yellow eyes, barred underparts, yellow legs) are more likely to be polymorphic (29% of species) than those without (8% of species). Phylogenetic analyses confirm correlated evolution of hawk-like features and cuckoo polymorphism. We suggest that mimicry dynamics are particularly likely to promote the evolution of various guises in parasitic cuckoos to beat host defences.

Spatial distribution of mountainous regions and classifications of economic development in China

China is a mountainous country with a great diversity of landform and geomorphology.This diversity underlines the need for regionalization and classification.This study defines the mountain terrains and regions with three criteria-elevation,relative height,and slope,and examines the extent of mountainous regions by using county as the basic administrative unit.According to the three parameters of economic base,resident income and development potential,we classified the economic development level in mountainous regions of China.The findings reveal that the extent of the mountainous region accounts for 74.9% of the China's Mainland's total area.The economic development of mountainous regions in China is classified into 4 main types and 23 subtypes.

Multi-scale interactions in interpersonal coordination

Background:Interpersonal coordination is an essential aspect of daily life,and crucial to performance in cooperative and competitive team sports.While empirical research has investigated interpersonal coordination using a wide variety of analytical tools and frameworks,to date very few studies have employed multifractal techniques to study the nature of interpersonal coordination across multiple spatiotemporal scales.In the present study we address this gap.Methods:We investigated the dynamics of a simple dyadic interpersonal coordination task where each participant manually controlled a virtual object in relation to that of his or her partner.We tested whether the resulting hand-movement time series exhibits multi-scale properties and whether those properties are associated with successful performance.Results:Using the formalism of multifractals,we show that the performance on the coordination task is strongly multi-scale,and that the multi-scale properties appear to arise from interaction-dominant dynamics.Further,we find that the measure of across-scale interactions,multifractal spectrum width,predicts successful performance at the level of the dyad.Conclusion:The results are discussed with respect to the implications of multifractals and interaction-dominance for understanding control in an interpersonal context.

Multifractal Characteristics of Intermittent Turbulence in the Urban Canopy Layer

The multifractality of energy and thermal dissipation of fully developed intermittent turbulence is investigated in the urban canopy layer under unstable conditions by the singularity spectrum for the fractal dimensions of sets of singularities characterizing multifractals. In order to obtain high-order moment properties of smallscale turbulent dissipation in the inertial range, an ultrasonic anemometer with a high sampling frequency of 100 Hz was used. The authors found that the turbulent signal could be singular everywhere. Moreover, the singular exponents of energy and thermal dissipation rates are most frequently encountered at around 0.2, which is significantly smaller than the singular exponents for a wind tunnel at a moderate Reynolds number. The evidence indicates a higher intermittency of turbulence in the urban canopy layer at a high Reynolds number, which is demonstrated by the data with high temporal resolution. Furthermore, the temperature field is more intermittent than the velocity field. In addition, a large amount of samples could be used for verification of the results.

A new self-adaptive remeshing approach

This paper proposes a self-adaptive approach to converting irregular genus-O meshes into those with subdivision connectivity. To assure a maximal utilization of the multiresolution techniques on the remesh, we map the original mesh onto the unit sphere and construct a base mesh with only four vertices. We also introduce a self-adaptive relocation operation, which is used to adapt the vertex distribution of the spherical subdivision mesh to that of the parameterized mesh, to improve the visual appearance of the remesh. The experimental results show that our method can not only make the number of irregular vertices in the remesh as small as possible, but also preserve the details of the original mesh well.

A Preliminary Phylogenetic Analysis of Luidia (Paxillosida: Luidiidae) from Chinese Waters with Cytochrome Oxidase Subunit I (COI) Sequences

Luidia Forbes （Paxillosida： Luidiidae） are common soft bottom sea stars with 49 described species. Because of substan- tial morphological diversity, the taxonomy of the genus is complex and hasn＇t been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of tyro- chrome oxidase subunit I （COI） gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetie relationships. The molecular phy- logeny exhibited three main clades, each with strong bootstrap support： Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species （L. quinaria von Martens, L. yesoensis Goto, L. ehangi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray） from Chinese waters; and Clade C including L. maculata Miiller ＆ Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alter- nata-Group assigned by D6derlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to rec- ognize them as separate species. Cryptic species may exist in ＇Luidia quinaria＇ from the Yellow Sea and the Sea of Japan. Meaning- ful morphological characters need further investigation in Luidia.

A method for choice of optimum scale on land use monitoring in Tarim River Basin

Optimal scale is one of the important issues in ecology and geography.Based on land-use data of the Tarim River Basin in Xinjiang of China in the 1950s,regarding the area of land use types as the parameter in scale selecting,the histograms of the patches in area are charted.Then,by reinforcing the normalized scale variances(NSV) with 3 landscape indi-ces,the scale characteristics of land use in the Tarim River Basin can be summarized.(1) NSV in the Tarim River up to a maximum at scale of 1:50,000 which is considered appropriate for the Tarim River.(2) Diversity indices of saline land are consistent with NSV's.Diversity indices and NSV of sandy land showed that the appropriate scale is in the same scale domain.There is a significant difference between diversity indices and NSV of forestland and shrub-land.(3) Fractal dimension of sandy land and saline land showed a hierarchical structure at a scale of 1:10,000.Fractal dimension of forestland and shrubland are distributed under the same hierarchical structure in the region.

资产组合优化的多分形模型及实证分析

将马尔科夫转换多分形模型引入均值-CVaR框架,构建资产组合优化的多分形模型,并给出最优组合投资策略的求解步骤.实证分析结果表明,基于多分形模型的组合策略在描述性统计分析、风险调整收益分析、经济表现分析以及策略稳定性分析中的表现均优于基于CCC-GARCH模型的组合策略,考虑多分形性确实有助于改善资产组合策略.文章所构建的模型和实证结果为资产组合投资实践提供了有益的参考.

MULTIPLICITY-PRESERVING TRIANGULAR SET DECOMPOSITION OF TWO POLYNOMIALS

In this paper, a multiplicity-preserving triangular set decomposition algorithm is proposed for a system of two polynomials, which involves only computing the primitive polynomial remainder sequence of two polynomials once and certain GCD computations. The algorithm decomposes the unmixed variety defined by two polynomials into square free and disjoint （for non-vertical components, see Definition 4） algebraic cycles represented by triangular sets which may have negative multiplicities. Thus, the authors can count the multiplicities of the non-vertical components. In the bivariate case, the amthors give a complete algorithm to decompose tile system into zeros represented by triangular sets with multiplicities. The authors also analyze the complexity of the algorithm in the bivariate ease. The authors implement the algorithm and show the effectiveness of the method with extensive experiments.

Temperature Properties in Polydisperse Granular Mixtures

Numerical simulations are employed to consider the problem of determining the granular temperatures of the species of a homogeneous heated granular mixture with a power-law size distribution. The partial granular temperature ratios are studied as functions of the fractal dimension D, the restitution coefflcient e, the rescaled viscosity time, the average occupied area fraction φ, the total particle number N and the number fraction. Different species of particles in a power-law system typically do not have the same mean kinetic energy, namely the granular temperature. It is found that the extent of nonequipartition of kinetic energy is determined by the fractal dimension D, the restitution coemcient e and the rescaled viscosity time, while is insensitive to the total particle number N, the area fraction φ and the number fraction.

Joint Multifractal Analysis of Scaling Relationships Between Soil Water-Retention Parameters and Soil Texture

Soil water-retention characteristics at measurement scales are generally different from those at application scales, and there is scale disparity between them and soil physical properties. The relationships between two water-retention parameters, the scaling parameter related to the inverse of the air-entry pressure （avG, cm- 1） and the curve shape factor related to soil pore-size distribution （n） of the van Genuchten water-retention equation, and soil texture （sand, silt, and clay contents） were examined at multiple scales. One hundred twenty-eight undisturbed soil samples were collected from a 640-m transect located in Fuxin, China. Soil water-retention curves were measured and the van Genuchten parameters were obtained by curve fitting. The relationships between the two parameters and soil texture at the observed scale and at multiple scales were evaluated using Pearson correlation and joint multifractal analyses, respectively. The results of Pearson correlation analysis showed that the parameter c^vG was significantly correlated with sand, silt, and clay contents at the observed scale. Joint multifractal analyses, however, indicated that the parameter ~vG was not correlated with silt and sand contents at multiple scales. The parameter n was positively correlated with clay content at multiple scales. Sand content was significantly correlated with the parameter n at the observed scale but not at multiple scales. Clay contents were strongly correlated to both water-retention parameters because clay content was relatively low in the soil studied, indicating that water retention was dominated by clay content in the field of this study at all scales. These suggested that multiple-scale analyses were necessary to fully grasp the spatial variability of soil water-retention characteristics.