水电站施工度汛方案优化设计分析

随着经济的发展以及社会的进步,水电站在我国正逐渐得到越来越广泛的应用,在水电站的施工过程中,常常会遇到各种难以预料的情形,这就需要在设计方案的时候根据实际工作中的经验以及通过科学分析等方式得出的可能出现的状况进行种种提前的处理及解决方案。水电站的施工质量之所以需要得到严格把控,因为其质量对于水电站的功能能不能得到最大程度的发挥起着决定性的作用。正是因为上述原因,对于水电站施工必须层层把关,严格按照相关标准来进行,这样才能使得水电站工程的质量以及功能得到有效的保障与实施。本文对水电站施工过程中可能出现的与度汛有关的情形做了相关的总结,并结合实际经验根据度汛方案进行了一定的分析与探讨,希望能对实践起到一定的作用。     

基于动态RBF网络的预测控制在中速磨煤机优化控制的应用

针对大型火电厂直吹式制粉系统的时滞和非线性特点,将基于动态RBF网络模型的预测控制应用于MPS中速磨煤机的优化控制中。通过对M-RAN算法的改进,加快了对非线性系统的辨识速度。建模仿真证明了改进M-RAN算法的有效性和实时性,并结合预测控制解决了系统的时滞问题;应用结果也表明该方法具有良好的动态响应和较强的鲁棒性。     

WRF-LTNGDA: A lightning data assimilation technique implemented in the WRF model for improving precipitation forecasts

This study introduces WRF-LTNGDA, a lightning data assimilation technique implemented in the Weather Research and Forecasting (WRF) model. This technique employs lightning for improving the representation of convection by means of controlling the triggering of the model's convection parameterization scheme. The development and implementation of WRF-LTNGDA was carried out in a framework that could easily allow for its exploitation in real-time forecasting activities. The assimilation algorithm was evaluated over eight precipitation events that took place in Greece in the years 2010–2013. Results clearly show that lightning forcing has a positive impact on model performance. The conducted analysis revealed that the employment of WRF-LTNGDA induces statistically significant improvements in precipitation verification scores, especially for high rainfall accumulations. Separate examination of one of the eight case studies highlighted the overall better agreement between the modelled and observed spatial distribution of precipitation when lightning data assimilation was applied, than in the control simulation.     

Use of polymers for taste-masking pediatric drug products

Many drugs are bitter and overcoming this bitter taste is a major barrier in developing a successful product, especially for pediatric patients. Approaches to mask taste include changing taste perception, creating a physical barrier to separate the drug from interacting with taste buds, and changing drug solubility. This review is focused on polymers and the different ways these materials are used to achieve taste masking. Attention is given to systems that are easily swallowed, as swallowability is another concern in developing palatable products for pediatrics. Variables that should be considered when selecting a taste-masking approach are also presented.     

New privilege-based visual cryptography with arbitrary privilege levels

Recently, Hou et al. introduced a novel (2, n) privilege-based visual cryptography scheme (PVCS) with various privilege levels of shadow images. In this scheme, a shadow with a higher privilege contributes more recovered information, while a lower privileged shadow has the less recovery capability. Moreover, the visual quality of stacked result depends on the total sum of privilege levels for all involved shadows in reconstruction. Unfortunately, the PVC scheme has the inconsistency of the contrast of recovered image and the sum of privilege levels. Accordingly, an enhanced Hou et al.’s (2, n)-PVC scheme (EPVCS) is proposed to solve this inconsistency problem. However, the EPVCS is not a general solution to implement all PVCSs with arbitrary privilege levels, and it also has the unequal whiteness of shadows. In this paper, we first extend Hou et al.’s (2, n)-EPVCS with a correct privilege levels achieving the consistency of the contrast and the sum of privilege levels. Then we construct a (2, n)-PVCS to allow arbitrary privilege levels and provide the equal whiteness for each shadow.     

空心薄壁墩施工技术初探

通过介绍韩家庄1号桥薄壁墩翻转模法的施工,对薄壁墩翻转模施工进行了详细论述,并针对影响高墩施工精度的因素提出了预防措施及质量安全措施,以期指导类似桥梁施工。     

AHP法在水利工程设计方案优选中的应用

以水利工程中某水库除险加固为例,采用层次分析法(AHP)对工程存在的风险进行分析。根据模型中各层次因素的相对重要性差异,定量表示客观现实情况,通过计算确定每一层次全部因素相对重要性权值,得到了各方案相对最高层目标的重要性次序组合权值,为定性问题的定量解决提供了理论依据和方法。计算结果表明:应用AHP法确定方案二最优。     

Feature integration across space, time, and orientation.

The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases—presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space-based models of feature integration cannot be extended to dynamic stimuli. We suggest that feature integration is guided by perceptual grouping operations that maintain the identity of perceptual objects over space and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于航弹的动基座传递对准研究

在几种传递对准方法和航弹传递对准特点的基础上,提出采用速度+姿态传递对准方案.根据实际情况合理简化传递对准数学模型,采用改进的卡尔曼滤波方法分别对速度匹配和姿态匹配子系统误差估计,同时还对陀螺漂移进行估计,然后采用联邦滤波算法对子系统的公共状态进行信息融合得到全局估计,提高系统的计算能力和可靠性.仿真试验表明姿态误差在20'以下,速度误差在0.1m/s以下,该方法适合航弹传递对准要求.