离散

Based on integral transformation, analytical solution for the wave transmission equations in 1-D inhomogeneous media is derived. By dividing the media into layers and considering the continuous conditions between the interfaces, the transfer matrix of amplitude of waves is obtained.

利用积分变换，用解析方法求解了一维非均匀区域的不同性质对弹性波传播时波幅变化的影响；将非均匀区域离散成均匀的薄层，结合相邻层的连续条件，建立了数值解法的波幅传递矩阵。

The main work and the originality points of this dissertation could be concluded as the following parts:(1) To analyze systematically the mathematical model of LES of air flow in great space, under the case of isothermal and non-isothermal, as well as the combined action of buoyancy and strain. Some basic problems are studied about the LES application into airflow simulation of great space, such as boundary conditions, spatial difference scheme and time advancing scheme, time step etc., which creates the basis for the LES application to indoor airflow simulation.(2) Both the instantaneous and time averaged flow field of great space with multiple jets under isothermal and non-isothermal cases are explored with large eddy simulation method, and also discussed the dynamic characteristics and the law of fluidflow in the great space.(3) Based on the results of LES of the great space and the Fanger thermal comfort indexes, it is brought forward the concept of the series of dynamic thermal comfort evaluating indexes, which could be divided into thermal comfort index with time averaged properties PD, PPD, PMV, thermal comfort index with instantaneous properties IPD, IPPD, IPMV, and time averaged thermal comfort indexes TAPD, TAPPD, TAPMV, and transient situations time averaged thermal comfort indexes TTAPD, TTAPPD, TTAPMV. The differences among them and the calculation methods are discussed, and the four kinds of indexes are calculated with the thermal comfort index PD as an example.(4) Based on the LES results it is discussed the hot air stratification phenomena in air-conditioned buildings in the case with air supply and return registers on the ceiling and the case on the sidewall. The fundamentals of the hot air stratification are studied and the relations of estimating hot air stratification are brought forward.(5) With the advanced apparatus such as hot wire film anemometer IFA300 and laser particle field anemoscope, corresponding model test and site measurements have been done, which are compared with the simulation results and LES is proved a very promising method in air flow simulation indoor.

本文主要工作既创新点体现在以下几个方面：(1)系统分析了等温、非等温和考虑剪切力与浮升力综合作用的高大空间大涡模拟数学模型，并研究了高大空间大涡模拟在室内气流仿真应用中的一些基本问题，如边界条件、空间离散格式和时间推进格式、时间步长选择等问题，为大涡模拟在室内气流计算中的广泛应用打下了基础；(2)首次用大涡模拟方法研究了高雷诺数下高大空间多射流在等温、非等温情况下的瞬时流场和时均流场分布，并探讨了多射流流场的动态特性和流动规律；(3)基于大涡模拟的动态仿真结果和Fanger的热舒适指标，首次系统地提出了动态热舒适评价指标体系的概念：即基于时间平均参数的热舒适指标PD、PPD、PMV；基于瞬时参数的瞬时热指标IPD、IPPD、IPMV；基于时间平均热舒适指标TAPD、TAPPD、TAPMV；以及沿行动迹线的时间平均热舒适指标TTAPD、TTAPPD、TTAPMV，并分析了四类热舒适指标的差异性和计算方法，还以PD值为例对四类指标分别进行了计算；(4)基于数十种工况下空调房间大涡模拟的结果，研究了空调建筑上送上回和侧送侧回两种情况下热分层现象，并探讨了热分层的基本规律，首次提出了避免热分层现象的判断公式；(5)在暖通空调领域，首次使用IFA300热线风速仪、激光粒子速度场仪等先进设备，完成了与大涡模拟相对应的模型试验，并把实测结果与仿真结果进行了对比，说明LES在室内气流仿真方面是一种很有前景的方法。

Aim To study the effects of walk-off angle on the coefficients of reflection and transmission.

目的 研究离散角对反射与透射系数的影响。

When 527nm laser interacted with Al targets, the dispersion of angular distribution of scattered lights was serious.

激光辐照铝盘靶时，散射光能量分布的离散性较大。

It is noted that the index of angular dispersion for both sexes was smaller,and the mean angular deviation was bigger,which was close to the mean angle by the circular distribution.

但需注意的是，经圆形分布分析，男、女性的角度离散程度指标r均较小，S较大。

Application of discrete-ordinate method in calculation of light angular distribution in biological tissue［J］.

离散坐标法在计算生物组织内光场空间角分布中的应用［J］。

Based on global coupling, a method which can induce both synchronization and anti-synchronization by constructing coupled chaotic system with identical antisymmetric chaotic systems was presented.

提出在具有反对称性的等同混沌子系统中，利用全局耦合实现同步与反同步共存的一般方法，论证了其在离散系统和连续系统上的适用条件。

In discrete-time linear system, apriori H〓 filtering, aposteriori H〓 filtering, L〓 apriori filtering with an H〓 error bound, L〓 aposteriori filtering with an H〓 error bound, robust H〓 apriori filtering, robust apriori L〓 filtering, and robust aposteriori L〓 filtering to noise inputting matrix uncertainty system are considered.

对离散线性系统，研究了确定性系统的H〓验前滤波和验后滤波、H〓约束下的L〓验前滤波及验后滤波、不确定性系统的H〓验前滤波、鲁棒L〓验前滤波及噪声输入矩阵不确定性情况下的鲁棒L〓验后滤波。

Variable structure control of discrete-time systems and its applications in power electronic apparatus are discussed in this paper.

本文探讨了离散系统的变结构控制及其在电力电子装置中的应用。

Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.

在此基础上，(1)结合连续小波变换的特点和卷积的微分性质，提出了使用Gaussian函数的一阶和二阶导数，Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法，与其他导数计算方法(包括数字微分法，多项式滤波法，Fourier变换法和离散小波变换法)相比，本法简单便捷，计算速度快，对于噪声含量较高的信号(S/N为5)，只要适当调节尺度即可获得比较满意的结果。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。