Superconvergence of nonconforming finite element penalty scheme for Stokes problem using L^2 projection method

A modified penalty scheme is discussed for solving the Stokes problem with the Crouzeix-Raviart type nonconforming linear triangular finite element. By the L^2 projection method, the superconvergence results for the velocity and pressure are obtained with a penalty parameter larger than that of the classical penalty scheme. The numerical experiments are carried out to confirm the theoretical results.

GEOMETRIC CONSTRUCTION OF ASSOCIATION SCHEMES FROM DEGENERATE QUADRICS INPROJECTIVE SPACES PG(2ν+δ+ι-1, Fq) FOR q ODD

Let Fq be a finite field with q elements, where q is a power of an odd prime,In this paperl the authors consider a projective space PG(2v + δ + l, Fq) with dimension 2v + δ + l, partitioned into an affine space AG(2v + δ + l, Fq) of dimension 2v + δ + l and a hyperplane H = PG(2v + δ + l - 1, Fq) of dimension 2v + δ + l - 1 at infinity, where l ≠0.The points of the hyperplane H are next partitioned into four subsets. A pair of points a and b of the affine space is defined to belong to class i if the line ab meets the subsct i of H. Finally, a family of four-class association schemes are constructed, and parameters are also computed.

A Genetic Fuzzy Analytical Hierarchy Process Based Projection Pursuit Method for Selecting Schemes of Water Transportation Projects

The optimal selection of schemes of water transportation projects is a process of choosing a relatively optimal scheme from a number of schemes of water transportation programming and management projects, which is of importance in both theory and practice in water resource systems engineering. In order to achieve consistency and eliminate the dimensions of fuzzy qualitative and fuzzy quantitative evaluation indexes, to determine the weights of the indexes objectively, and to increase the differences among the comprehensive evaluation index values of water transportation project schemes, a projection pursuit method, named FPRM-PP for short, was developed in this work for selecting the optimal water transportation project scheme based on the fuzzy preference relation matrix. The research results show that FPRM-PP is intuitive and practical, the correction range of the fuzzy rained is both stable and accurate; preference relation matrix A it produces is relatively small, and the result obtherefore FPRM-PP can be widely used in the optimal selection of different multi-factor decision-making schemes.

Design of Water Disinfection Scheme for Rural Drinking Water Safety Project

As further promotion of the rural drinking water safety project in whole country, small villages in vast countryside have been or will be equipped with safety drinking water project. We analyzed necessity of the rural drinking water disinfection, discussed disinfection method suitable for rural drinking water characteristics, and put forward disinfection schemes for different water supply sources.

Eco-environmental benefit assessment of China's South-North Water Transfer Scheme——the middle route project

This paper assess the eco-environmental benefits that may come from the middle route project of China's South-North Water Transfer Scheme(SNWT) with principles and methods of eco-economics and planning reports of SNWT's middle route project. Some benefits were calculated in monetary units. To make sure that the results can be comparable with normal monetary indices, concrete assessment objects and the parameters are prudently selected according to the major characteristics of the project and its water import region. Primary assessment revealed that in different project construction stages, the benefit could be more than 13 07 billion RMB Yuan in 2010 and 19 79 billion RMB Yuan in 2030, respectively. The monetary value tends to increase with social-economic development. To realize these potential benefits, however, calls for more endeavors.

Selection method of risk response schemes for mining project based on fuzzy preference relations

To overcome the subjectivity of experts in the process of risk response scheme selection, according to the theory of group decision making, a selection method and flow of the risk response schemes for a mining project was proposed based on fuzzy preference relation and consistency induced ordered weighted averaging (C-IOWA) operator,which can overcome the loss of information in the process of group decision making to a great degree, and improve its efficiency and quality.A numeric example was introduced to illustrate the application of the method, also validating the method as scientific and practicable.

Velocity Projection with Upwind Scheme Based on the Discontinuous Galerkin Methods for the Two Phase Flow Problem

The upwind scheme is very important in the numerical approximation of some problems such as the convection dominated problem, the two-phase flow problem, and so on. For the fractional flow formulation of the two-phase flow problem, the Penalty Discontinuous Galerkin (PDG) methods combined with the upwind scheme are usually used to solve the phase pressure equation. In this case, unless the upwind scheme is taken into consideration in the velocity reconstruction, the local mass balance cannot hold exactly. In this paper, we present a scheme of velocity reconstruction in some H(div) spaces with considering the upwind scheme totally. Furthermore, the different ways to calculate the nonlinear coefficients may have distinct and significant effects, which have been investigated by some authors. We propose a new algorithm to obtain a more effective and stable approximation of the coefficients under the consideration of the upwind scheme.

Estimating minimum ecological water required of the western route first stage project of China＇s south-to-north water transfer scheme for water exporting rivers

It is well known that there is abundant water resources in basin of the Yangtze River, the first largest river in China, which is mainly located in Southern China. However, water resources is very scarce in the basin of the Yellow River, which is mainly located in Northern China. So the western route project of south-north water transfer scheme （WRP-SNWTS） aims to transfer water from the Yangtze River to the Yellow River. The area of WRP-SNWT, located in the upper reaches of the Yangtze River and the main areas of Sichuan and the marginal areas of the Qinghai-Tibet Plateau, has sufficient water resources but fragile ecology and environment. Therefore, it is necessary for WRP-SNWT to analyze the ecology water required. Based on the planning principles of from low elevation to high elevation, from small to large, from short to long and from easy to difficulty, the WRP-SNWT will be constructed through three stage projects. The western route first stage project of the south-north water transfer scheme （WRFST-SNWTS） is planned to transfer 4×10^9m^3/a from six tributaries of the Yalong river and from Dadu river to Jiaqu of Yellow River.. Daqu river and Niqu river are the branches of Xianshui river. Sequ river, Duke river, Make river and Ake river are the branches of Dadu river, which account for 65-70% of the total river run-off. It need more research and the rest run-off can satisfy channel ecology water required. According to analysis ecological water required which mainly satisfy for aquicolous biology in water-exporting region, such as low air temperature. Fish and aquicolous biology main living from May to August, and rivers are iced up from December to March of next year, ecology water required mainly for fish and aquicolous biology. The flow criterion of Tennant method is modified. The ecology water required of WRFSP-SNWTS is estimated by the flow data of Zhuwo gauging station, Zhuba gauging station, Chuosijia gauging station and Zumuzu gauging station. The result show that the ecology water required calculated by modified Tennant less 1 l percent than that of Tennant. This estimating result can supply more water resources for transferring to Yellow River. Meanwhile, this can supply gist for research transferring water of WRFSP-SNWTS.

菏兰铁路引入兰考南站方案研究

研究目的:设计方案比选是一个多目标、多因素、多层次的系统工程。因引入新增线路,结合预测运量,既有线路的通过能力远期已趋于饱和,需进行各方案的优缺点分析,并合理选择引入方案。本文通过菏兰铁路引入兰考南站方案研究,选择合理的引入方案,确定合理的线路走向,达到降低工程难度和节省投资的目的。研究结论:(1)本文通过对运输组织、技术经济、车站咽喉疏解近期工程、同步实施线下工程、已实施工程等诸多方面的研究,结合河南省最新城际铁路网规划,分析各方案的优缺点,确定出相对优化的推荐方案,即上下行联络线分别在东西咽喉疏解方案;(2)通过运营条件、线路长度、工程投资等诸多方面的分析,结合沿线村镇分布、联络线设置条件等因素,对引入兰考南站线路方案进行了研究,推荐东绕仪封乡以R=3 000 m限速引入兰考南站方案;(3)本文研究可为类似项目的方案比选奠定理论基础,具有一定的参考价值。

风电叶片铺层三维激光投影系统标定方案

为提高风电叶片复合材料多层铺贴的质量与效率,文中设计了一套视觉辅助自动标定的三维激光投影系统。系统采用全反射镜作为标靶,引入红外相机,建立视觉辅助的投影系统模型,利用相机与激光振镜间图像的单应性关系,标定二者之间的转换关系,并由此解算投影标靶在振镜投影坐标系的位姿,最后利用奇异值分解的方法求解激光振镜的投影矩阵。通过自主搭建三维激光投影系统实验平台,以投影幕布和网格纸作为投影面进行重投影试验,证明系统的可行性。实验结果表明,系统可以实现三维激光投影系统的自动标定,在投影距离为3 m的情况下,投影精度达到3.3 mm。

复杂地质条件下南疆某水库工程枢纽布置比选探讨

笔者以南疆某水库工程为例,对复杂地形地质条件下枢纽布置方案比选进行探讨。通过分析存在的不良地质情况,考虑泄水建筑物在高水头、高流速运行下的结构安全及右岸高边坡问题,拟定了3个枢纽布置方案。从地形地质条件、枢纽布置、水力学条件、运行管理、工程施工、工程投资等方面进行比较分析,选择合理紧凑的枢纽布置方案,为类似工程提供一定的参考。

对某城乡供水工程自动化控制的设计和应用研究

城乡供水自动化是解决农村饮水安全的重要措施,能够有效保证供水工程的管理决策能力和应用服务水平。总结了某城乡供水项目中自动化控制的设计和应用,不仅能有效的弥补水利工程建设过程中存在的不足,此外在实现水利工程长远发展、提高水利工程管理水平中也发挥了重要性作用,可以实现城乡供水后期运行中节水、减员、降本、增效的功能优势,推动了城乡供水的均等化服务,有效巩固当地的脱贫攻坚工作。

医院电力系统技改方案设计与实践——以江苏省苏北人民医院为例

以江苏省苏北人民医院电力系统技改项目为研究对象,运用管理工具从计划、实施、检查和处理四个维度分析医院电力系统技改项目的要点,设计了技改方案并成功实施,持续提升了医院供电能力。技改项目顺利实施得益于管理工具在医院电力系统技改方案中的应用,可为同类技改项目提供新思路。

基于数值模拟的平原河网水质改善精准化引水方案研究

为探究引水工程对杭嘉湖平原河网城镇化地区的水质改善效果,以海宁市洛塘河圩区平原河网水系为例,针对平原河网水系流通性差与河流污染状况,通过MIKE11建立了洛塘河圩区河网水系的水动力水质耦合模型,提出并模拟不同引水方案,分析研究其影响机理,对不同方案的引水作用过程及其效果进行综合分析和比较。结果表明,合理选择引水地点和增加引水量对圩区水质改善作用明显,但相同情况下对初始浓度高的月份改善作用较弱;采用引水启停调度方案,短时间高流量间歇性引水,可更经济科学地使河网水质达到设计目标标准。研究结果可为平原河网区域水系综合整治提供参考依据。

瓦斯隧道施工通风风机选型及经济研究

为准确掌握隧道施工通风造价投资情况,保证隧道施工过程成本的有效管控,依托某隧道现场施工,计算分析了两种隧道在不同海拔下的需风量、管路阻力及风机配置情况,并根据不同隧道风机配置的不同引起的铁路工程定额基价的不同,详细阐述了通风成本造价投资的差异,得出了以下结论:1)不同隧道间风机供风量差异较大,风机功率相差约20%,因此在现场施工过程中应根据实际情况计算风机输入功率并合理配置风机;2)风机功率差与每昼夜通风时间差导致通风机械台班单价以及台班数量存在差异,瓦斯工区较非瓦斯工区增加82.18万元。3)随着海拔的升高,风机供风量增幅较为显著,两种隧道的通风费用增幅分别为78.4%和89.1%,均有较大增幅,因此高原地区隧道施工时还需更为严格地控制通风成本。

新疆车尔臣河取水水源工程布置及方案比选分析

取水可靠性是引水工程正常运行的主要影响因素,合理选择取水水源位置是确保取水可靠性的前提。文章通过对新疆车尔臣河取水水源工程现状的调查梳理,总结研判取水工程存在的主要问题,本着取水水源含沙量应分别满足灌溉和城乡用水需求的原则,从工程建设投资、工程“等效益”等方面进行引水水源方案比选,分析推荐的水源的安全可靠性和取水水量的保障率,以及方案布局的优缺点,可为多泥沙河流引水水源布置提供技术支撑,为类似工程提供借鉴。

扩建LNG接收站火炬方案比选

规模化扩建的LNG接收站火炬系统设计方案主要有新增火炬和原有火炬系统改造两种,在互联互通的需求下,通过泄放量核算对现有火炬剩余能力进行校核,在剩余能力不满足泄放需求时,应通过压降核算、经济、安全及技术等多方面的比选综合确定最优方案。以国内某接收站二期项目为依托,对LNG接收站扩建项目的火炬系统配置方案进行比选研究。基于对现有工程、本期建设规模及远期规划进行泄放量核算,并通过HYSYS仿真模拟对新增火炬和依托一期火炬系统改造两种方案进行火炬管网压降核算。综合考虑本期及远期的火炬泄放需求,优选分期新增火炬的设计方案,单台火炬处理能力80 t/h,并新建D1168 mm×12.7mm火炬管道以满足储罐26 kPa(G)泄放压力下的需求。

“三环节分析”及其在水土保持方案编制中的应用

管道项目是水土保持方案编制中难度最大的项目之一,科学地分析管道项目中的重要环节是做好水土保持方案编制的基础和关键。通过总结前人的成果和自身的工作经验,结合管道项目具有水土保持功能的特点,提出了“三环节分析”理论,有针对性地补充和完善了水土保持防治措施。项目实施后,水土流失能得到全面的控制和治理,为此类工程水土保持方案的编制提供了新的思路和方法。

水电工程设计方案投资比选效率影响因素及提升策略研究

水电工程设计阶段周期长、时间跨度大、涉及专业多,且设计方案不断更新变化,提高设计方案的投资比选效率可较快地确定各方案投资,为工程设计方案决策提供依据,有效缩短设计周期,同时方案合理的投资比选也能减少后期施工阶段由于设计变更和工程返工对工程投资的影响。基于ISM模型,从项目外部和内部识别水电工程设计方案投资比选效率的影响因素,构建影响因素层级关系模型并针对性提出比选效率提升策略。模型结果显示,政策法规体系,项目复杂性是影响比选效率的根本原因,项目设计周期是影响比选效率的直接原因,也是其余因素作用之后的直接表现形式。