基于Hermite插值的管片拼装机轨迹规划

盾构施工中,管片拼装机需要先完成一环的拼装,才能往前进行推进。目前管片拼装机工作效率较低,直接影响着掘进速度。为了提高管片拼装机的拼装效率,结合Hermite插值算法提出一种新的拼装轨迹规划方法,通过各动作始末两点进行Hermite插值,构造出五次多项式,通过加速度、功率等约束解出各具体解。选取用时最长的作为时间基准,重新构造其余五次多项式。在降低启动冲击的同时,将管片拼装机的拼装效率提升了近一倍。     

斜坡稳定性安全系数的统一解

斜坡是山区、冻土地区,以及黄土地区广泛发育的一类地质形态.斜坡具有滑动深度小、滑动面易于确定、易受降雨和滑动面上水分影响的浅层滑坡特点.一般地,将地下水流线概化成与斜坡互相平行的直线和流线相互平行的水平线.从两类特殊渗流条件下的孔隙水压力入手,应用有效应力原理得出了无限斜坡稳定性安全系数的统一解,并通过工程实例对所得出的统一解进行了验证.文中提出的考虑渗流影响的无限斜坡稳定性分析方法对类似滑坡分析有一定的参考价值,尤其对于复杂渗流条件下的、流场研究程度较高的重要道路工程地段及桥涵附近边坡稳定性分析、坝基抗滑稳定性分析与验算等问题的研究具有实践指导意义.     

单层带孔玻璃板孔边破坏应力的试验研究

玻璃面板的强度设计中 ,带孔玻璃板孔边的破坏应力至今尚没有方便的公式来计算 ,目前设计中孔边应力一般不予计算 ,然而孔边应力恰是强度设计中应力控制的一个关键点。在试验的基础上 ,通过曲线拟合和插值的方法得到了带孔玻璃板的孔边破坏应力 ,为点支承玻璃板的设计提供了参考。     

以青岛空间环境为例塑造山水城市空间形态

在分析青岛城市空间环境特色和近年来发展建设的基础上,应用山水城市的概念,对城市空间形态由宏观到微观进行初步研究探索,用以指导城市的实际规划和建设。     

用样条函数构成室外逐时温度的插值方法及其误差估计

建筑空调的全年能耗分析以及空调系统的动态模拟,都需要输入全年逐时气象数据.作者在构成“建筑空调能耗分析用气象资料”时,采用气象站每天八次的定时观测气温值,用样条函数方法插值确定逐时室外温度值.本文对样条函数插值方法,以及端点条件对插值误差的影响进行分析,井介绍减少插值误差的方法.     

中外居住郊区化对比

详细地阐述了居住郊区化的发展过程及经验，就我国居住郊区化的现状及郊区化进程中存在的问题进行了探讨，对中外居住郊区化的发展进行了比较研究，以借鉴西方发达国家的经验，更好地做好我国大城市郊区住宅的建设。     

An emission-weighted proximity model for air pollution exposure assessment

Background

Among the most common spatial models for estimating personal exposure are Traditional Proximity Models (TPMs). Though TPMs are straightforward to configure and interpret, they are prone to extensive errors in exposure estimates and do not provide prospective estimates.

Method

To resolve these inherent problems with TPMs, we introduce here a novel Emission Weighted Proximity Model (EWPM) to improve the TPM, which takes into consideration the emissions from all sources potentially influencing the receptors. EWPM performance was evaluated by comparing the normalized exposure risk values of sulfur dioxide (SO₂) calculated by EWPM with those calculated by TPM and monitored observations over a one-year period in two large Texas counties. In order to investigate whether the limitations of TPM in potential exposure risk prediction without recorded incidence can be overcome, we also introduce a hybrid framework, a ‘Geo-statistical EWPM’. Geo-statistical EWPM is a synthesis of Ordinary Kriging Geo-statistical interpolation and EWPM. The prediction results are presented as two potential exposure risk prediction maps. The performance of these two exposure maps in predicting individual SO₂ exposure risk was validated with 10 virtual cases in prospective exposure scenarios.

Results

Risk values for EWPM were clearly more agreeable with the observed concentrations than those from TPM. Over the entire study area, the mean SO₂ exposure risk from EWPM was higher relative to TPM (1.00 vs. 0.91). The mean bias of the exposure risk values of 10 virtual cases between EWPM and ‘Geo-statistical EWPM’ are much smaller than those between TPM and ‘Geo-statistical TPM’ (5.12 vs. 24.63).

Conclusion

EWPM appears to more accurately portray individual exposure relative to TPM. The ‘Geo-statistical EWPM’ effectively augments the role of the standard proximity model and makes it possible to predict individual risk in future exposure scenarios resulting in adverse health effects from environmental pollution.     

锦绣中华百艺广场大跨度挑棚结构设计研究

深圳锦绣中华百艺广场挑棚结构采用四边形空间钢管桁架和斜拉索组合的杂交结构,钢管桁架最大悬挑长度为32m。为了加强结构在风荷载作用下的整体稳定,通过反复调整承重索和稳定索的内力和桁架的截面,对结构进行了强度和刚度的优化设计。介绍了该结构的风洞试验结果,结构计算、设计及主要构造措施,并给出了在荷载作用下的结构反应和受力特点。     

数字地价模型建立过程中的插值方法研究——以上海内环线地区为例

对反距离加权平均(IDW)插值法和克立格(Kriging)插值法两种空间插值方法在数字地价模型(DLPM)建立过程中的插值效果进行比较研究,采用上海内环线地区内的实际样本点数据进行有关实证分析。利用空间插值软件Surfer8.0对上海内环线地区内地价样本点使用上述两种不同的插值方法插值生成不同的插值结果文件,再利用GIS软件MapInfo7.5把插值结果文件生成数字地价栅格专题图,最后用随机选取的验证点对不同的插值结果进行比较分析。研究结果表明:反距离加权平均(IDW)插值法比克立格(Kriging)插值法插值效果更佳,其插值结果更加接近实际地价分布,而且,反距离加权平均(IDW)插值法属于确定性插值法,也简单、易操作,样本点处的插值结果也可以更好的接近样本点的实际地价值,使得数字地价模型(DLPM)的建立更加可靠、可行。     

A meshfree model without shear-locking for free vibration analysis of first-order shear deformable plates

Difficulty in imposing essential boundary conditions in the standard element-free Galerkin method (EFG) is due to the lack of Kronecker’s delta function property of shape functions generated by moving least square approximation (MLS). In this paper, we further apply a meshfree model based on the moving Kriging interpolation method (MK) to free vibration analysis of first-order shear deformable plates. The deflection and two rotation field variables of plate are approximated by the MK method, which is employed to construct the shape functions having the delta function property. With this approach, the drawback in enforcement of the boundary conditions caused by the MLS is now avoided. The present formulation is based on the first-order shear deformation plate theory (FSDT) associated with an effective elimination of the shear-locking phenomenon completely, and hence the approach is applicable to both moderately thick and thin plates. Numerical examples considering various aspect ratios and different boundaries are examined and solutions on natural frequencies obtained by the present method are then compared with existing reference solutions, and very good agreements are observed.