Measurement method and pipe wall misalignment adjustment algorithm of the pipe butting machine

This paper presents a runout measurement method and a novel finite grouping method to predict and optimize the rotational angle and translational displacement of butting pipes to minimize pipe wall misalignment (PWM). This study develops a method to minimize the PWM of the pipes excluding the positions of welding seams. In this method, the measurement data are divided into finite groups and the criteria are created to identify the positions of welding seams and eliminate the effect of the welding seams. Finally, the rotational angle and translational displacement of the butting pipes are optimized to minimize the PWM. A butting machine is designed to implement this method. The machine is benchmarked by a standard smooth pipe to minimize system errors. Three butting experiments have been performed with welded pipes of diameter 406 mm. The comparison shows that the computation results agree with the experimental results very well. The maximum PWMs in three experiments are less than 1.87 mm, which satisfies the butting requirements, that is, a PWM of less than 2.0 mm. Then, the uncertainties of the measurement results are discussed.     

无级气量调节系统在新氢压缩机中的应用

分析齐鲁炼油厂第三柴油加氢装置新氢压缩机增上无级调量系统的可行性,简要介绍无级调量系统的基本原理,阐述新氢压缩机增上无级调量系统的调试和节电效果。     

Simultaneous 2D and 3D perception for stereoscopic displays based on polarized or active shutter glasses

Viewing stereoscopic 3D content is typically enabled either by using polarizing or active shutter glasses. In certain cases, some viewers may not wear viewing glasses and hence, it would be desirable to tune the stereoscopic 3D content so that it could be simultaneously watched with and without viewing glasses. In this paper we propose a video post-processing technique which enables good quality 3D and 2D perception of the same content. This is done through manipulation of one view by making it more similar to the other view to reduce the ghosting artifact perceived without viewing glasses while 3D perception is maintained. The proposed technique includes three steps: disparity selection, contrast adjustment, and low-pass filtering. The proposed approach was evaluated through an extensive series of subjective tests, which also revealed good adjustment parameters to suit viewing with and without viewing glasses with an acceptable 3D and 2D quality, respectively.     

基于MATLAB的GPS网三维平差方法研究

研究了GPS控制网平差模型，探讨了采用MATLAB进行GPS网三维平差的可行性，并结合GPS控制网三维无约束平差实例的结果进行分析。实例证明，基于MATLAB进行GPS网平差具有精度高、编程简单、工作效率高、平差过程清晰等优点。为解决复杂的GPS网平差计算提供了新的便捷途径。     

离心式通风机的安装及使用维护的分析

离心式通风机是除尘通风系统中四大件之一,是一种比较精密的运转机械。安装调试及维护的质量好坏直接会影响风机的性能,使用寿命及经济效果等一系列问题。针对风机的安装、使用维护、调整、主要故障及其产生原因等方面进行分析阐述,以供大家参考。     

谈2013建设工程工程量清单计价规范的变化

介绍了2013《建设工程工程量清单计价规范》的出台背景与形式,对风险分担、招标控制价、投标报价、签约合同价、竣工结算价五个方面内容作了详细研究,指出新规范使中国工程造价进入了全过程精细化管理的新时代。     

基于C#和AutoCAD的Delaunay三角剖分算法的实现

本文是在.net平台下AutoCAD二次开发方面的文章,是对Delaunay三角剖分算法的总结。在算法的编程实现过程中,作者提出了许多新颖的设想,并最终获得了正确的计算结果和理想的时间效率。针对算法实现的整体框架和步骤,几个算法关键点以及算法的时间复杂度方面,文中提供了比较详细的论述。     

Balancing CapEx reduction and network stability with stable routing–virtual topology capacity adjustment (SR–VTCA)

This paper investigates the merits of the SR–VTCA (stable routing–virtual topology capacity adjustment) approach as a mechanism to find a beneficial trade-off between network stability and reduction in capital expenditures (CapEx). These are two main objectives for the entities that own the optical infrastructure, such as network operators (NOs), and those also acting as Internet service providers (ISPs). The SR–VTCA scheme is a novel approach to adapt transparent optical networks to time-varying traffic by adjusting the number of lightpaths between node pairs, while keeping the IP routing unchanged. Lightpath bundling (LB) and anycast (AS) switching are combined in SR–VTCA operation to advertise lightpath additions/removals to the IP layer as mere adjustments (increments or decrements) in the capacity, allowing to keep the IP routing stable, and thus, simplifying control plane operations. On the contrary, a fully-reconfigurable (FR) network design, where IP routing can be also modified, would increase the burden in the control plane, but at a higher CapEx reduction, since the optical infrastructure is used more efficiently. In this work, we investigate the CapEx overprovision introduced by SR–VTCA with respect to a FR scheme. In order to do this, SR–VTCA planning problem is first modeled as a MILP formulation. A heuristic procedure based on traffic domination is then proposed to solve large instances of the problem. Exhaustive experiments are conducted comparing the SR–VTCA solutions obtained by the aforementioned MILP and heuristic proposal with solutions found by other optimization methods presented in the literature to solve the FR planning problem. Finally, the results show that SR–VTCA can achieve similar results to the FR case in terms of CapEx reduction, while a huge number of IP reroutings are saved by maintaining IP stability. Thus, SR–VTCA provides an advantageous balance between CapEx overprovisioning and the control plane overhead associated with IP rerouting.     

An MCFC operation optimization strategy based on PID auto-tuning control

Molten Carbonate Fuel Cell (MCFC) has been emerging as a promising renewable power system. It is still challenging to operate the MCFC to meet its varying demands because of its nonlinearity and complex dynamics. This paper proposes a novel MCFC operation framework based on PID auto-tuning control. A case study is presented to illustrate the applicability of the strategy with some comments.     

A second-order algorithm for curve orthogonal projection onto parametric surface

Repeated use of point projection to find the projection of a curve on a surface is rather inefficient as the iteration procedures in point projection is typically slow. A novel curve projection scheme is proposed for computing the orthogonal projection of a progenitor curve onto a parametric surface. Under this scheme, the projection curve is parameterized using the parameter of the progenitor curve. Differential geometric characteristics of the projection curve are analysed. A marching method with error adjustment is used to calculate the projection curve. Several examples are presented and comparisons are made to demonstrate the effectiveness of the proposed scheme.