公路施工中特殊结构物放样的计算方法

桥梁锥形护坡、曲线斜桥梁板等结构物的施工放样在公路施工中非常重要。本文结合实际工作介绍了这两种特殊结构物施工放样的计算方法及计算过程。方法简单实用，可提高工作效率并保证施工放样的精度。     

刚度突变轨道结构的连续地基梁模型基本解及其应用

用刚度突变的连续弹性支承梁模型表示桥梁和路基两种不同类型的轨道支承条件，给出了在力学模型上的任意位置有一集中力作用解析解，具有多个集中荷载作用的结果可以通过叠加得到，此结论可应用于其他刚度突变连续地基梁结构中。还对不同刚度比、不同加载位置时钢轨的应力和位移进行了讨论。     

Assessing the performance of the least developed countries in terms of the Millennium Development Goals

This article presents a proposal for assessing the progress of least developed countries towards the achievement of the Millennium Development Goals over the period 2000–2015. Composite indices are built to perform spatial and temporal benchmarking relying on the P2 Distance method. The results are contrasted with other indices developed under a multi-criterion approach with a double reference point. The main findings are that all the countries have improved their situation and country disparities have been reduced. Cambodia and Ethiopia have registered the best trends and South Sudan and Timor-Leste show the worse performance. Considering the position in the 2015 ranking, Rwanda and Bhutan performed the best, while Somalia and Chad rank in the last position. Having now reached the end of the Millennium Development Goals period, the gap with respect to the world average indicates that much work remains to be done in the 2030 Agenda for Sustainable Development.     

中立型Timoshenko射线方程的强迫振动性

研究了中立型Ｔｉｍｏｓｈｅｎｋｏ射线方程４ｔ４〔ｕ＋λｕ（ｘ，ｔ－τ）〕＋ａ２ｕｔ２－ｂ４ｕ２ｘｔ２＋ｃ４ｕｘ４＋Ｃｘ，ｔ，ｕ，ｕ（ｘ，σ（ｔ））＝ｆ（ｘ，ｔ），（ｘ，ｔ）∈Ｊ×Ｒ＋解的强迫振动性，其中Ｊ＝（０，Ｌ），Ｒ＋＝（０，∞），λ，ａ，ｂ，ｃ为非负常数，τ＞０是常数，ｕ＝ｕ（ｘ，ｔ）．     

A Benchmarking Approach to Forecast Combination

This article is concerned with the development of a statistical model-based approach to optimally combine forecasts derived from an extrapolative model, such as an autoregressive integrated moving average (ARIMA) time series model, with forecasts of a particular characteristic of the same series obtained from independent sources. The methods derived combine the strengths of all forecasting approaches considered in the combination scheme. The implications of the general theory are investigated in the context of some commonly encountered seasonal ARIMA models. An empirical example to illustrate the method is included.     

On hypothesis testing for Poisson processes. Singular cases

ABSTRACT

We consider the problem of hypothesis testing in the situation where the first hypothesis is simple and the second one is local one-sided composite. Wedescribe the choice of the thresholds and the power functions of different tests when the intensity function of the observed inhomogeneous Poisson process has two different types of singularity: cusp and discontinuity. The asymptotic results are illustrated by numerical simulations.     

A Geometric Approach to Nonlinear Econometric Models

Conventional tests for composite hypotheses in minimum distance models can be unreliable when the relationship between the structural and reduced‐form parameters is highly nonlinear. Such nonlinearity may arise for a variety of reasons, including weak identification. In this note, we begin by studying the problem of testing a “curved null” in a finite‐sample Gaussian model. Using the curvature of the model, we develop new finite‐sample bounds on the distribution of minimum‐distance statistics. These bounds allow us to construct tests for composite hypotheses which are uniformly asymptotically valid over a large class of data generating processes and structural models.     

广州市产业结构与就业结构的协调性分析

研究了高速列车与厦深铁路韩江大桥(48+2×80+88+48) m道岔连续梁的空间耦合振动中的桥梁响应问题。以模态坐标法形成结构的动力方程,适用SAP2000形成基本振型并由此获得振型参数,利用Matlab软件编写求解程序,得到了道岔连续梁动力响应的一些成果。     

工程中的间接加载及设计建议

针对工程中均布荷载情况下的间接加载问题，提出计算方法及构造措施，供设计参考。     

游梁式抽油机工作系统计算机仿真分析

针对游梁式抽油机占据着有杆泵采油地面设备的主导地位，但其能耗高一直制约着石油工业的发展的实际,开展了优化游梁式抽油机结构、对游梁式抽油机进行节能改造的研究，成功实现了对游梁式抽油机工作系统的仿真分析。利用MATLAB软件中的动态仿真工具SIMULINK，对游梁式抽油机的3个系统模块，包括原动机、减速器与抽油机主体分别进行建模，进而建立了曲柄平衡游梁式抽油机系统的计算机仿真模型。通过实例的仿真结果与实测数据的对比分析，验证了仿真模型的正确性和合理性，为抽油机节能改造提供了理论依据及实验研究模型。