一个非线性偏微分方程广义解的存在性

本文是利用h-半连续的单调算子的理论证明一个非线性偏微分方程解的存在性。     

在油藏岩中驱替化学溶液模拟方程的差分方法

讨论了将一些不可压缩的可混化学溶液去驱替油藏岩中的石油这一模拟过程的边值问题，提出了解决这一类问题的两种差分格式及其算法，并给出了其收敛条件。     

用算子展开法求解 Fredholm 积分方程

提供了另一种求解积分方程的方法。利用 Hilbert 空间来研究 Fredholm 积分算子,并证明了可利用一组标准正交基将 Fredholn 积分算子展开,从而使积分方程得到简化。应用这一方法给出了一般第二类 Fredholm 积分方程的严格解析解。文中还对具体积分方程进行了求解并与严格解和其它方法所得的解进行了比较,结果吻合得很好。     

D-optimal designs for combined polynomial and trigonometric regression on a partial circle

Consider the D-optimal designs for a combined polynomial and trigonometric regression on a partial circle. It is shown that the optimal design is equally supported and the structure of the optimal design depends only on the length of the design interval and the support points are analytic functions of this parameter. Moreover, the Taylor expansion of the optimal support points can be determined efficiently by a recursive procedure. Examples are presented to illustrate the procedures for computing the optimal designs.     

Sieve Estimation of Time-Varying Panel Data Models With Latent Structures

We propose a heterogeneous time-varying panel data model with a latent group structure that allows the coefficients to vary over both individuals and time. We assume that the coefficients change smoothly over time and form different unobserved groups. When treated as smooth functions of time, the individual functional coefficients are heterogeneous across groups but homogeneous within a group. We propose a penalized-sieve-estimation-based classifier-Lasso (C-Lasso) procedure to identify the individuals’ membership and to estimate the group-specific functional coefficients in a single step. The classification exhibits the desirable property of uniform consistency. The C-Lasso estimators and their post-Lasso versions achieve the oracle property so that the group-specific functional coefficients can be estimated as well as if the individuals’ membership were known. Several extensions are discussed. Simulations demonstrate excellent finite sample performance of the approach in both classification and estimation. We apply our method to study the heterogeneous trending behavior of GDP per capita across 91 countries for the period 1960–2012 and find four latent groups.     

基于HTFWGBM算子的供应商选择模型研究

由于供应商选择中的的复杂性与不确定性以及人类认知的有限性，从而导致信息融合失真和决策结果不准确的情况。针对决策属性以犹豫三角模糊数（HTFN）给出的供应商的选择问题，本文提出一种基于HTFGWBM算子的决策算法。首先，针对犹豫三角模糊数和几何Bonferroni平均算子理论，分别定义了犹豫三角模糊几何Bonferroni平均（HTFGBM）算子和犹豫三角模糊几何加权Bonferroni平均（HTFGWBM）算子，同时分别研究了算子的幂等性，置换不变性，单调性和有界性等性质。其次，基于HTFGWBM算子构建新型犹豫多属性决策模型，结合HTFN排序方法进行备选供应商排序。最后通过算南水北调中线工程中的供应商选择实例证明了决策模型的可行性与有效性。结果表明，通过调整模型参数，模型具有一定的延展性和容错能力，能够很好的进行科学决策。     

Modelling activity times by hybrid synthetic method

Uncertain (manual) activity times impact a number of manufacturing system modules: plant and layout design, capacity analysis, operator assignment, process planning, scheduling and simulation. Direct observation cannot be used for non-existent production lines. A hybrid direct observation/synthetic method derived from Method Time Measurement available in industry is proposed. To determine accurate activity times required by heuristics and metaheuristics optimisation, manufacturing system modules are modelled by MILP and operator efficiency parameters are used for time standardisation. Among human factors considered are skill and ergonomics. Application to the sterilisation of reusable medical devices is extensively described. Experimental data taken from observation on the field and a worst-case date have shown the model direct applicability for professionals also to non-manufacturing cases.