Display reflectance: Basics,measurement, and rating

Abstract— In this paper, methods and instruments for measurement and evaluation of reflection characteristics are reviewed as needed for research and development of electronic displays and for material and surface modeling with ray‐tracing and rendering software packages. Contrast under ambient illumination and recognizability under daylight illumination are prime development targets in the electronic‐display field, while computation and synthesis of realistic scenes and objects are pushing the need for physical data in computer graphics applications. Three categories of instruments are available for detailed reflection analysis. They are based on (1) gonioscopic (mechanical) and conoscopic (optical) directional scanning, (2) imaging approaches, and (3) on arrangements with variable source or receiver aperture. The capabilities, advantages, and limitations of these methods are introduced and discussed in order to facilitate appropriate selection of methods and instruments. For illustration purposes we present typical results obtained from commercial electronic display screens. A basis for continued widespread implementation and standardization of reflection metrology as required for objective rating and comparison of electronic‐display screen performance under ambient illumination is provided.     

明渠水流泥沙运动水深平均及力矩方程的理论和验证

首次提出了水流泥沙运动水深平均及其力矩方程的概念 ,并从理论上推导出这套方程组。提出水流泥沙运动力矩方程的目的有两个 ,一是在不增加空间维数的情况下可以有效地恢复水流泥沙因子沿水深分布信息 ,克服目前普遍使用的水深平均方程过多地忽略沿水深分布信息的缺点 ;二是增强模型的模拟能力。针对这两个目的是否能真正得到体现 ,分别从理论和实验室资料两个方面对新推导的力矩方程进行了全面的检验。理论验证结果表明 ,一维的力矩方程除了能模拟水深平均的流速和含沙量 ,还能够较好地模拟水流泥沙因子沿水深分布信息 ,这充分说明了一维力矩方程的二维特性。为了检验力矩方程的模拟能力 ,特别选取了一些极端的水流泥沙运动实验 ,如清水冲刷、点源加沙和深槽回淤等。模拟结果表明 ,力矩方程对于这些极端的水沙运动具有较好的模拟能力     

固井声幅-变密度测井的影响因素分析

利用声幅－变密度测井进行固井质量的评价受到诸多因素的影响，各种影响因素对声幅－变密度测井资料的影响作用有较大的差异，根据大量测井资料分析和实验研究，对仪器偏心、测井时间，套管尺寸与重量，地层岩性，气侵、水泥环微间隔等因素的影响作用进行了较为深入的分析，为各种影响因素的识别与校正提出了相应的方法和依据。     

战术弹道导弹落点预报的一种方法

根据椭圆弹道理论，提出了一种可以用于反战术弹道导弹作战的预测弹道及预报落点的方法，给出了算例，并分析了产生误差的原因和对预测结果的影响程度。     

建筑墙体表面传热系数辨识研究

对实验房间南向墙体内表面中心区域的换热过程进行实验，发现当风速在0－5．5m/s之间时，表面传热系数在8－18W（m^2.K）之间波动，而风向对墙体表面传热系数影响不大；用辅助变量法分析墙体表面传热过程，并结合实验推导出墙体表面传热系数。模型的预测结果与实测结果吻合良好。     

MEMS光开关及其与光纤组装方式的研究

光开关是一种在光路中应用极其广泛的光无源器件,可用于扫描、投影、通讯等多种不同的领域,其中用于全光通讯中连接光纤之间的光开关日渐成为人们关注的焦点.高性能、低成本、又能大量生产的MEMS光开关很好地满足了全光网络对器件的要求.本文对这种MEMS光纤光开关的类型、特点以及研究现状进行了介绍,并给出了MEMS光开关与输入输出光纤的组装与自组装以及主要方式.     

糯扎渡水电站机组主保护方案

结合糯扎渡水电站大型机组的发电机结构、发电机中性点引出方式及主接线对发电机主保护方案进行了分析研究，提出了发变组主保护方案，并初步确定了发电机中性点CT配置方案。同时也对主要的后备保护及异常运行保护进行了分析，并提出了设置方案。     

Motion and structure interpretation of an optical switch

This paper focuses on tracking, reconstruction and motion estimation of a well-defined MEMS optical switch from a microscopic view. For out-of-view reconstruction, a homography capable of transforming feature points and feature lines between a microscopic image and a CAD model of the switch is implemented. The homography between two sequential microscopic images is decomposed and factorized for motion estimation. Optical flow has also been explored to provide rough estimations of rotation centre and angle. The paper also illustrates motion parameter optimization principles to deal with uncertainty inherent in micro world. After non-linear optimization, estimation accuracy for rotation angle and rotation centre can reach 0.06° and pixel level, respectively.     

Control of discrete time nonlinear systems with a time-varying structure

In this paper, we present a control methodology for a class of discrete time nonlinear systems that depend on a possibly exogenous scheduling variable. This class of systems consists of an interpolation of nonlinear dynamic equations in strict feedback form, and it may represent systems with a time-varying nonlinear structure. Moreover, this class of systems is able to represent some cases of gain scheduling control, Takagi-Sugeno fuzzy systems, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations. We present two control theorems, one using what we call a “global” approach (akin to traditional backstepping), and a “local” approach, our main result, where backstepping is again used but the control law is an interpolation of local control terms. An aircraft wing rock regulation problem with varying angle of attack is used to illustrate and compare the two approaches.     

方圆坯铸机开发新断面自动化程序的实现

文章介绍了包钢连铸机结晶器液位、喷淋水、热坯压力等主要参数实现自动控制的过程,阐述了上述参数如何根据不同铸坯断面而改变,并针对钢厂开发新断面如何实现参数的切换提出解决办法.