Characterizing heterogeneity in vehicular traffic speed using two-step cluster analysis

In order to analyze the heterogeneity in vehicular traffic speed, a new method that integrates cluster analysis and probability distribution function fitting is presented. First, for identifying the optimal number of clusters, the two-step cluster method is applied to analyze actual speed data, which suggests that dividing speed data into two clusters can best reflect the intrinsic patterns of traffic flows. Such information is then taken as guidance in probability distribution function fitting. The normal, skew-normal and skew-t distribution functions are used to fit the probability distribution of each cluster respectively, which suggests that the skew-t distribution has the highest fitting accuracy; the second is skew-normal distribution; the worst is normal distribution. Model analysis results demonstrate that the proposed mixture model has a better fitting and generalization capability than the conventional single model. In addition, the new method is more flexible in terms of data fitting and can provide a more accurate model of speed distribution.

Analytical solution for functionally graded anisotropic cantilever beam under thermal and uniformly distributed load

The bending problem of a functionally graded anisotropic cantilever beam subjected to thermal and uniformly dis-tributed load is investigated,with material parameters being arbitrary functions of the thickness coordinate. The heat conduction problem is treated as a 1D problem through the thickness. Based on the elementary formulations for plane stress problem,the stress function is assumed to be in the form of polynomial of the longitudinal coordinate variable,from which the stresses can be derived. The stress function is then determined completely with the compatibility equation and boundary conditions. A practical example is presented to show the application of the method.

Bending Stresses of Steel Web Tapered Tee Section Cantilevers

Although commonly used, no design method is available for steel web tapered tee section cantilevers. This paper investigates the bending stresses of such beams. Relationships between the maximum compressive stress and the degree of taper were investigated. An analytical model is presented to determine the location of the maximum stress when subjected to a uniformly distributed load or a point load at the free end and was validated using finite element analysis and physical tests. It was found that the maximum stress always occurs at the support when subjected to a uniformly distributed load. When subjected to a point load at the free end and the degree of taper is up to seven, it was found that Miller＇s equation could be used to determine the location of the maximum stress. However, it is shown that when the degree of taper is greater than seven, Miller＇s equation does not accurately predict the location and the analytical model should be used. It was also found that the location of the maximum stress was solely dependent on the degree of taper, while a geometric ratio, fl was required to determine the magnitude of the maximum stress. A simple method that predicts the magnitude of the maximum stress is proposed. The average error in the prediction of the magnitude of the maximum stress is found to be less than 1.0%.

Cauchy-Poisson Problem for a Two-layer Fluid with an Inertial Surface

This paper is concerned with the generation of waves due to initial disturbances at the upper surface of a two-layer fluid, as the upper layer is covered by an inertial surface and the lower layer extends infinitely downwards. The inertial surface is composed of thin but uniform distribution of non-interacting material. In the mathematical analysis, the Fourier and Laplace transform techniques have been utilized to obtain the depressions of the inertial surface and the interface in the form of infinite integrals. For initial disturbances concentrated at a point, the inertial surface depression and the interface depression are evaluated asymptotically for large time and distance by using the method of stationary phase. They are also depicted graphically for two types of initial disturbances and appropriate conclusions are made.

Taxonomy of the lesser jerboa Jaculus jaculus (Dipodidae,Rodentia) based on allozymic and morphological variation

The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown taxonomic status, which are frequently grouped into two taxa： J. jaculus and J. deserti. We assessed the taxonomic status of this taxon in Tunisia using allozymic （phylogenetic analysis of 23 genetic loci encoding 16 enzymatic proteins） and morphological （multivariate analysis of 13 craniodental characters） analyses of 136 J. jaculus specimens collected from seven localities within its distribution range. Allozymic analysis clearly indicated the existence of two distinct groups of J. jaculus, with a mean genetic distance （D） value of 0.99 and FΩ=0.52. Individuals within the two groups did not show any obvious geographical structuration, even within the Matmata locality which represents the meeting point for the two groups where they were found in sympatry. Additionally, morphometric analysis of 13 craniodental characters was clearly separated the two groups. These results were obtained over a very restricted area of the total distribution of J. jaculus and strongly suggest the occurrence of two separate and often sympatric species within the currently accepted J.jaculus in Tunisia： J.jaculus and J. deserti

The analysis for stress-strain characteristics of concrete cutoff wall built in deep cladding foundation

Combined with a proposed homogeneous earth dam in deep cladding foundation, Duncan E-B model is applied to simulate dam-filled material, apply to three-dimensional nonlinear finite element method, attain the stress-strain distribution and alteration in concrete cutoff wall in completion and water storage periods, analysis the stress state in the contact element between concrete cutoff wall and cladding foundation, provide the corresponding measures. The calculation results show that the design of concrete cutoff wall and homogeneous earth dam is reasonable.

10万t／a甲醇装置转化炉烟气偏流问题研究

大庆油田甲醇厂10万t/a甲醇联产7000m^3/h（标态）纯氢装置于1998年10月建成投产。该工程采用低温氧化锌脱硫、饱和塔增湿、一段蒸汽转化、低压合成、三塔精馏的工艺路线，生产甲醇同时从转化气中采用吸附技术提取7000m^3/h（标志）纯氢，供给炼化分公司异构脱蜡装置。

SPHERICAL MEANS, DISTRIBUTIONS AND CONVOLUTION OPERATORS IN CLIFFORD ANALYSIS

New higher dimensional distributions are introduced in the framework of Clifford analysis.They complete the picture already established in previous work, offering unity and structuralclarity. Amongst them are the building blocks of the principal value distribution, involvingspherical harmonics, considered by Horvath and Stein.

A NEW PROCEDURE FOR TESTING NORMALITY BASED ON THE L_2 WASSERSTEIN DISTANCE

This paper proposes a new goodness-of-fit test for normality based on the L~ Wasserstein distance. The authors first construct a probability through the Bootstrap resampling. Although the probability is not distributed uniformly on the interval （0, 1） under the null hypothesis, it is shown that its distribution is free from the unknown parameters, which indicates that such a probability can be taken as the test statistic. It emerges from the simulation study of power that the new test is able to better discriminate between the normal distribution and those distributions with short tails. For such alternatives, it has a substantially better power than existing tests including the Anderson-Darling test and Shapiro-Wilk test, which are two of the best tests for normality. In addition, the sensitivity analysis of tests is also investigated in the presence of moderate perturbation, which shows that the new test is a rather robust test.

Improved simulation method for urban free-space optical links based on the finite Markov state model

An improved method is proposed to simulate the scintillation introduced by the turbulence, based on the finite Markov state model. As a contrast to the literatures, uniformly distributed variables take place during a certain state, which contributes to equivalent simulation of the intensity fluctuations with fewer states than the traditional Markov model. It's also discovered that the proposed Markov model with 20 states provides a satisfactory approximation to the experimental results in the auto-covariance analysis. Moreover, the outage probability and mean fading time are more accurate than those of the traditional Markov model with equivalent states.