Multiple attribute decision making method based on trapezoid fuzzy linguistic variables

The problem of multiple attribute decision making under fuzzy linguistic environments, in which decision makers can only provide their preferences （attribute values）in the form of trapezoid fuzzy linguistic variables（TFLV）, is studied. The formula of the degree of possibility between two TFLVs is defined, and some of its characteristics are studied. Based on the degree of possibility of fuzzy linguistic variables, an approach to ranking the decision alternatives in multiple attribute decision making with TFLV is developed. The trapezoid fuzzy linguistic weighted averaging （TFLWA） operator method is utilized to aggregate the decision information, and then all the alternatives are ranked by comparing the degree of possibility of TFLV. The method can carry out linguistic computation processes easily without loss of linguistic information, and thus makes the decision results reasonable and effective. Finally, the implementation process of the proposed method is illustrated and analyzed by a practical example.

网格曲面的三种典型参数化方法的分析与比较

根据模型上相邻三角面的关系,采用广度优先策略依次为每个三角面指定纹理坐标。对于具有约束面的搜索与映射过程,首先使相邻面有最小的纹理误差,最后采用图的分割技术将纹理拼接成一个连续的整体。该算法适用于任意曲面和多种纹理。

(0,2)型张量场诱导的线性变换的显表达式提取方法

对于黎曼流形(M,g)上(0,2)型光滑张量场R诱导出的线性变换R*:X(M)→X(M),其隐表达式为g(R*(X),Y)=S(X,Y),X,Y∈X(M),研究了从局部上提取出R*(X)的显表达式的方法.提出一种所谓g正定提取方法,并将这种方法进一步应用到度量保形变换下的线性变换Φ*(X),L*(X).

多尺度显著性区域提取的模板匹配

针对模板匹配过程中强遮挡、剧烈背景变化及物体非刚性形变等难题,本文提出了一种基于多尺度显著性区域提取的模板匹配算法。算法采用多尺度-显著性特征并行提取的方式:一方面利用空间金字塔模型将参考图像中的模板和待匹配图像中的目标区域分割成不同尺度的网格,采用可形变多相似性度量方法(Deformable Diversity Similarity,DDIS)计算不同尺度下的匹配得分;同时,算法提取模板区域的显著性区域图,形成模板区域的显著性得分;随后,利用显著性得分对不同尺度的匹配得分进行加权融合,在融合得到的匹配得分图上寻找最佳匹配区域。算法与取得目前最好结果的DDIS方法相比,AUC(Area Under Curve)指标提升2.9%。实验结果表明,显著性区域提取使匹配方法更加关注目标物体,削弱背景及遮挡物体对其影响,从而增强模板匹配方法对于背景变化及遮挡的抵抗能力。另外,空间金字塔模型能够增强模板匹配方法对于物体不同尺度下的特征提取,如物体的局部轮廓及结构特征等。二者结合有效地提高了匹配精度。

Shape Optimal System for Linear Elastic Structures

An integrated system FSOP2D,including modules for the shape optimal modeling,structural analysis,sensitivity analysis,optimal method library and post- processing,is developed.By selecting fictitious loads as the design variables that has a linear relationship with the grid point locations and using design sensitivity analysis of the domain method,it is easier to solve the velocity field.In the course of optimal iterations,mesh distortion is kept to a minimum,sensitivity derivatives of object function,stress constraints and displacement constraints are derived.Computation of sensitivity analysis is achieved in the system.Two engineering examples are used to prove the system's effectiveness,the optimal results can successfully be obtained by lesser number of iterations.

Grain structure and tensile property of Al-Li alloy sheet caused by different cold rolling reduction

The effect of cold rolling reduction(50%-90%)on the grain structures of solutionized 1445 Al-Li alloy sheet at525-575 ℃ was investigated through electron backscatter diffraction(EBSD).Although the solutionization temperature is elevated to 575 ℃,the sheet is not completely recrystallized.The main recrystallization model is subgrain coalescence and growth,and the non-recrystallization is due to the formed nano-sized Al3(Sc,Zr)dispersoids,which pin the grain boundaries,subgrain boundaries and dislocations.With increasing the cold rolling reduction,the fraction and size of the recrystallized grains in the sheet solutionized at525 ℃ are decreased,but the fraction of the subgrains is increased,leading to a decrease in the fraction of the deformed structures.Meanwhile,the number fraction of high-angle boundaries(HABs)is increased.Due to the decreased fraction of the deformed structures and increased fraction of the HABs,the T8-aged 1445 Al-Li alloy sheet displays a decrease trend in the strength and heterogeneity with increasing the cold rolling reduction.At higher solutionization temperature of 575 ℃,the fraction of the recrystallized grains and their size are obviously increased.

Slope analysis based on local strength reduction method and variable-modulus elasto-plastic model

Employing an ideal elasto-plastic model,the typically used strength reduction method reduced the strength of all soil elements of a slope.Therefore,this method was called the global strength reduction method(GSRM).However,the deformation field obtained by GSRM could not reflect the real deformation of a slope when the slope became unstable.For most slopes,failure occurs once the strength of some regional soil is sufficiently weakened; thus,the local strength reduction method(LSRM)was proposed to analyze slope stability.In contrast with GSRM,LSRM only reduces the strength of local soil,while the strength of other soil remains unchanged.Therefore,deformation by LSRM is more reasonable than that by GSRM.In addition,the accuracy of the slope's deformation depends on the constitutive model to a large degree,and the variable-modulus elasto-plastic model was thus adopted.This constitutive model was an improvement of the Duncan–Chang model,which modified soil's deformation modulus according to stress level,and it thus better reflected the plastic feature of soil.Most importantly,the parameters of the variable-modulus elasto-plastic model could be determined through in-situ tests,and parameters determination by plate loading test and pressuremeter test were introduced.Therefore,it is easy to put this model into practice.Finally,LSRM and the variable-modulus elasto-plastic model were used to analyze Egongdai ancient landslide.Safety factor,deformation field,and optimal reinforcement measures for Egongdai ancient landslide were obtained based on the proposed method.

Effects of curing under step-by-step load on mechanical and deformation properties of cemented gangue backfill column

A step-by-step load was utilized to mimic the load history of the backfill column in the in-situ curing process.The inner damage of the specimen during curing and uniaxial compressive testing was monitored by electrical resistivity and ultrasonic equipment.Results show that:1)Uniaxial compressive strength(UCS)and elastic modulus(EM)of the samples curing under pressure are higher than those of the control samples without pressure,ranging in ratio from 0.5%to 20.2%and 7.1%to 52.3%,respectively,and are influenced by the initial loading age(ILA)and stress strength ratio(SSR).The SSR during curing should not exceed 80%.2)The earlier the ILA is,the higher the total strain becomes.The higher the SSR applies,the larger the total strain gets.The creep strain increases with the increase of SSR and can be described by Burger’s viscoelastic creep model.When SSR is less than 80%,the earlier the ILA is,the smaller the creep strain becomes after the last step-loading.3)The stability of the early age backfill column under pressure can be monitored based on the change of ultrasonic pulse velocity(UPV)and electrical resistivity.

Totally Geodesic Invariant Subm anifolds of Contact Metric Manifold

The purpose of this paper is to give a sufficient and necessary condition of totally geodesic on invariant submanifold of contact metric manifold and is to generalize the results in [3] and [4].

Thermal deformation analysis of the composite material satellite antenna

Controlling the thermal deformation is a crucial index for the design of the satellite antenna. To calculate and measure the satellite antenna’s thermal deformation is also an important step for the design of satellite antenna. Based on the foundation of equivalent assumption, the thermal deformation of the parabolic satellite antenna was analyzed by the finite element method for different design project. The best design project that had the minimum of the thermal deformation could be obtained through changing the lay-angle, lay-layers and lay-thickness of each layer. Results show the asymmetry structure has the minimum of thermal deformation. This paper may provide useful information for the further investigation on the coupling of thermal-stress structure.

Deexcitation Energy of Superdeformed Secondary Minima as a Probe to Density Dependence of Symmetry Energy

Deexcitation energies of superdeformed secondary minima of odd-odd A u and T1 isotopes are investigated with the relativistic mean field （RMF） model where the isoscalar-isovector coupling is included to change the symmetry energy. It is verified by the theoretical analysis and numerical results that the deexcitation energies of superdeformed secondary minima relative to the ground states in these heavy nuclei are sensitive to differences in the symmetry energy. In particular, the linear correlation between the deexeitation energies of odd-odd Au and T1 isotopes and the neutron skin thickness in 208Pb is established. Moreover, explorations are extended to superdeformed candidates of other mass regions. It is found that the linear correlation can even be established between the deexcitation energies and the symmetry pressure at subsaturation density. These indicate that deexcitation energies can serve as a probe to the density dependence of the symmetry energy.

The deformation of Poincar subgroups concerning very special relativity

We investigate here various kinds of semi-product subgroups of Poincar6 group in the scheme of Cohen-Glashow＇s very special relativity along the deformation approach by Gibbons- Gomis-Pope. For each proper Poincar6 subgroup which is a semi-product of proper lorentz group with the spacetime translation group T（4）, we investigate all possible deformations and obtain all the possible natural representations inherited from the 5 - d representation of Poincar6 group. We find from the obtained natural representation that rotation operation may have additional accompanied scale transformation when the original Lorentz subgroup is deformed and the boost operation gets the additional accompanied scale transformation in all the deformation cases. The additional accompanied scale transformation has a strong constrain on the possible invariant metric function of the corresponding geometry and the field theories in the spacetime with the corresponding geometry.

Deformation dependence of symmetry energy coefficients of nuclei

Based on the semi-classical Thomas-Fermi approximation together with the Skyrme energy-density functional, we study the deformation dependence of symmetry energy coefficients of finite nuclei. The symmetry energy coefficients of nuclei with mass number A = 40, 100, 150, 208 are extracted from two-parameter parabola fitting to the calculated energy per particle. We find that the symmetry energy coefficients decrease with the increase of nuclear quadrupole deformations, which is mainly due to the isospin dependence of the difference between the proton and neutron surface diffuseness. Large deformations of nuclei can cause the change of the symmetry energy coefficient by about 0.5 Me V and the influence of nuclear deformations on the symmetry energy coefficients is more evident for light and intermediate nuclei.

On the quasidiagonality of Roe algebras

Let X be a noncompact discrete metric space with bounded geometry. Associated with X are two C*-algebras, the so-called uniform Roe algebra B*(X) and coarse Roe algebra C*(X), which arose from the index theory on noncompact complete Riemannian manifolds. In this paper, we describe the quasidiagonality of B*(X) and C*(X) in terms of coarse geometric invariants. Some necessary and suficient conditions are given, which involve the Fredholm index and coarse connectedness of metric spaces.

Dual mean Minkowski measures of symmetry for convex bodies

We introduce and study a sequence of geometric invariants for convex bodies in finite-dimensional spaces, which is in a sense dual to the sequence of mean Minkowski measures of symmetry proposed by the second author. It turns out that the sequence introduced in this paper shares many nice properties with the sequence of mean Minkowski measures, such as the sub-arithmeticity and the upper-additivity. More meaningfully, it is shown that this new sequence of geometric invariants, in contrast to the sequence of mean Minkowski measures which provides information on the shapes of lower dimensional sections of a convex body, provides information on the shapes of orthogonal projections of a convex body. The relations of these new invariants to the well-known Minkowski measure of asymmetry and their further applications are discussed as well.