Construction of Customized Mass-Stiffness Pairs Using Templates

This paper is a tutorial exposition of the template approach to the construction of customized mass-stiffness pairs for selected applications in structural dynamics. The exposition focuses on adjusting the mass matrix while a separately provided stiffness matrix is kept fixed. Two well known kinetic-energy discretization methods described in finite-element method (FEM) textbooks since the mid-1960s lead to diagonally lumped and consistent mass matrices, respectively. These two models are sufficient to cover many engineering applications. Occasionally, however, they fall short. The gap can be filled with a more general approach that relies on the use of templates. These are algebraic forms that carry free parameters. This approach is discussed in this paper using one-dimensional structural elements as examples. Templates have the virtue of producing a set of mass matrices that satisfy certain a priori constraint conditions such as symmetry, nonnegativity, invariance, and momentum conservation. In particular, the diagonally lumped and consistent versions can be obtained as instances. Thus those standard models are not excluded. Availability of free parameters, however, allows the mass matrix to be customized to special needs, such as high precision vibration frequencies or minimally dispersive wave propagation. An attractive feature of templates for FEM programming is that only one element implementation as module with free parameters is needed, and need not be recoded when the application problem class changes.     

Developing a Traffic Closure Integrated Linear Schedule for Highway Rehabilitation Projects

In recent years, the state departments of transportation have implemented a number of highway rehabilitation projects across the country. These projects differ fundamentally from new highway projects in that they require an uninterrupted flow of traffic throughout both the duration and geometric length of the project. Synchronization of traffic closure with the construction activities is crucial in such projects to avoid the traffic conflicts and prevent idle time for equipment and labor. Although most highway rehabilitation projects involve predominantly linear activities, the techniques of linear scheduling are not readily applicable to highway rehabilitation projects due to the conflict between the workzone and traffic flow. This paper documents the development of a traffic closure integrated linear schedule (TCILS) that addresses both traffic closure and work progress issues. The TCILS generates a single schedule for both the construction activities and the associated traffic closures. Visual and graphical features are also applied in the system, which makes it particularly applicable for highway rehabilitation projects. An actual concrete pavement rehabilitation project using the TCILS is presented as a sample of application. The findings from the sample project, although they are limited, show that the TCILS can be applied to an actual project. With recommended future development, the system is believed to be beneficial for both construction practitioners and academics.     

Using Weibull Analysis for Evaluation of Cost and Schedule Performance

Large amounts of money are lost each year in the construction industry because of poor schedule and cost control. Few contractors specify and follow systematic schedule monitoring practices. Traditionally, the earned value method (EVM) is used to control and monitor schedule performance using the schedule and cost performance indices which compare the budgeted cost of work performed to what was originally scheduled or what is actually expended. This paper presents a statistical approach, namely Weibull analysis, to evaluate stochastically the schedule performance of construction or design projects. The approach can be used in conjunction with the EVM to enhance the evaluation and control of schedule performance. Weibull analysis is a common method for failure analysis and reliability engineering used in a wide range of applications. In this paper, the applicability of Weibull analysis for evaluating and comparing the reliability of the schedule performance of multiple projects is presented. The various steps in the analysis are discussed along with an example in which two projects are analyzed and compared. The authors conclude that Weibull analysis has several advantages and provides a relatively robust and effective method for construction managers to better control and monitor their projects.     

单机架可逆冷轧机轧制规程优化设计

以唐钢冷轧薄板厂1 800 mm单机架可逆冷轧机的2级轧制规程为研究对象,在分析轧制负荷分配对冷轧带钢板形精度影响的基础上,系统研究了冷轧轧制模型,应用最优化方法编制了轧制规程设计程序并付诸工程实践。     

连续退火炉加热制度对IF钢性能的影响

 用IF冷轧带钢制作6组90°热模拟试样,经不同加热退火处理后,比较其平均晶粒度和力学性能。结果表明,经不同加热退火处理后,带钢平均晶粒度和物理性能呈规律性变化。在不影响产品使用性能的情况下,保持相同退火速度,适当降低加热退火温度可节能降耗。     

Optimal Layout Design of a Satellite Module Using a Coevolutionary Method with Heuristic Rules

The layout design of a satellite module belongs to a three-dimensional (3D) packing problem with mutual-conflicting performance constraints. Taking the layout design of a simplified commercial communication satellite as a background, based on the cooperative coevolutionary framework, this paper presents a coevolutionary method with heuristic rules for the optimal layout design of a satellite module. First, a whole satellite module layout problem is decomposed into several sublayout problems according to the multisubphysical structure of a satellite module. Second, a relaxation model is adopted to distribute all objects among subspaces. Third, a coevolutionary genetic algorithm is adopted to solve the detailed layout design within the subspaces. Finally, a heuristic combination-rotation (CR) method is adopted to adjust the constraints to obtain the final whole layout scheme. Compared with the coevolutionary approach and the all-at-once optimization approaches, computational results show that the CR method can improve the computational accuracy of solutions and the proposed heuristic coevolutionary method can produces better solutions within short running times.     

用组态软件实现棒材生产线的轧制表功能

比较了应用组态软件WinCC实现轧钢工艺中轧制表的各种方案之利弊,介绍了用VB脚本和Access数据库结合在马钢(合肥)棒材连轧生产线上的应用,并详细描述了模块化编程思路在轧制表的在线轧制和离线维护操作上的实现过程。     

Comparing Schedule Generation Schemes in Resource-Constrained Project Scheduling Using Elitist Genetic Algorithm

An issue has arisen with regard to which of the schedule generation schemes will perform better for an arbitrary instance of the resource-constrained project scheduling problem (RCPSP), which is one of the most challenging areas in construction engineering and management. No general answer has been given to this issue due to the different mechanisms between the serial scheme and the parallel scheme. In an effort to address this issue, this paper compares the two schemes using a permutation-based Elitist genetic algorithm for the RCPSP. Computational experiments are presented with multiple standard problems. From the results of a paired difference experiment, the algorithm using the serial scheme provides better solutions than the one using the parallel scheme. The results also show that the algorithm with the parallel scheme takes longer to solve each problem than the one using the serial scheme.     

用KH计算法编制铜板带压下规程

提出了编制铜板带压下规程的KH计算法,经过热轧4例和冷轧6例的计算对比,结果表明:KH计算法是可行的,可为今后优化压下规程创造条件,并将产生经济效益。     

借鉴国际经验发展循环经济

介绍了国外有关循环经济的发展状况及相关政策,阐述了我国工业炉窑在发展和促进循环经济方面的作用,并对在发展循环经济中要发挥工业炉窑的作用问题提出了建议.     

Synthesis of Y2O3 ： EU^3 ＋ Hollow Spheres Using Silica as Templates

The Y2O3 ： EU^3 ＋ hollow spheres were synthesized using the template-mediated method. XRD patterns indicated that the broadened diffraction peaks resulted from nanocrystals in Y2O3 ： EU^3 ＋ shells of hollow spheres. XPS spectra showed that the Y2O3 ： EU^3 ＋ shells were linked with silica cores by a Si-O-Y chemical bond. SEM and TEM observations showed that the size of the SiO2/Y2O3 ： EU^3 ＋ core-shell particle was about 100 nm, and the thickness of the Y2O3 ： EU^3 ＋ hollow sphere was less than 5 nm. The photoluminescence spectra of the SIO2/Y2O3 ： EU^3 ＋ core-shell materials and Y2O3 ： EU^3 ＋ hollow spheres had red luminescent properties, and the broadened emission peaks came from nanocrystals composed of the Y2O3 ： EU^3 ＋ shell.     

用组态王开发高炉监控系统

运用“KingView6．0”组态软件的强大功能开发了高炉监控系统，以实现对高炉及热风炉等设备运行状况的实时监测、故障报警、数据报表趋势分析与打印、历史数据记录及查询等功能。应用实践证明。该系统图形界面友好、数据采集准确可靠、操作方便、安全稳定。     

Numerical Simulation of Swirling Flow in Complex Hydroturbine Draft Tube Using Unsteady Statistical Turbulence Models

A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90° elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.     

MDMA and Performance Under a Progressive-Ratio Schedule of Water Delivery.

This study investigated the possible motivational effects of (±)3,4-methylenedioxymethamphetamine (MDMA, ecstasy) in water-deprived rats responding under a progressive-ratio 2 schedule of water delivery. Lower doses (1.0 and 1.8 mg/kg ip) had inconsistent effects on breakpoints and response rates, whereas higher doses (3.2 and 5.6 mg/kg ip) significantly decreased both response measures relative to vehicle control levels. Increasing the level of water restriction significantly increased both response measures, and decreasing restriction significantly decreased both response measures. This study found no evidence that MDMA increased the reinforcing efficacy of water, although prior findings have suggested that the drug might have such an effect. MDMA-induced changes in motor activity may account for the present results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

利用硅灰石制取白炭黑试验研究

介绍了白炭黑的特性和利用硅灰石制取白炭黑的工艺流程及影响因素，并通过提纯得到质量符合橡胶补强要求的白炭黑产品且应用效果较好。     

Canal Structure Automation Rules Using an Accuracy-Based Learning Classifier System, a Genetic Algorithm, and a Hydraulic Simulation Model. II: Results

An accuracy-based learning classifier system (XCS), as described in a companion paper (Part I: Design), was developed and evaluated to produce operational rules for canal gate structures. The XCS was applied together with a genetic algorithm and an unsteady hydraulic simulation model, which was used to predict responses to gate operation rules. In the tested cases, from 100 to 2,000 XCS simulations, each involving thousands of hydraulic simulations, were required to produce satisfactory rules. However, the overall fitness of the set of rules increased monotonically as XCS simulations progressed. Initial fitness started at an arbitrary value, and rules increased in strength by better achieving operational objectives during the training process. Fewer XCS iterations were required to increase the fitness as the rule population evolved. Calculated water depths approached the respective target depths for variable water delivery demand through turnout structures in the simulated canal systems. The water depth achieved stabilization inside a dead band of? ±?8% of the target depth after applying different turnout demand hydrographs to each reach. The calculated depth was inside the dead band 92% of the time in Reach 1, and 73% of the time in Reach 2 for the constant supply experiment. The water depth was inside the dead band 100% of the time in Reach 1, and 76% of the time in Reach 2 for the variable-supply experiment.     

运用Visual FoxPro开发固定资产管理系统

针对葫芦岛有色金属集团有限公司的固定资产管理,运用Visual FoxPro数据库技术,编制固定资产管理系统,借助于计算机技术,对原有的固定资产管理方式进行改变,并为下一步推行整个工厂的系统化管理做好准备.