离散问题

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。

This paper proposes an universal e-cash system based on partially blind signature which can be divided to small pieces of arbitrary number one time, so-called single-divisibility.

针对通用电子现金系统的难点在于其可分性，本文提出的方案以SK00系统为基础，实现其转移性(SK00公开问题)，并给商家颁发电子执照行使银行的部分职能，进而提出了一个显式可分(即一次性任意分割电子现金)的离线电子货币系统；同时利用以前的技术实现了一个采用树型结构的可分电子现金系统，并比较了这两个方案和以前方案的效率；二者安全性基于离散对数问题和强无碰撞Hash函数安全性；最后本文利用代理签名给出了一个新的部分盲签名方案。

Finite Element Method is an important means of engineering subject and has been proved to be a common method in many subjects. However, disadvantages still remained. During the structural analysis, large amount of high-order units were used in order to ensure the precision of arithmetic solution when using Finite Element Method to do discrete processing. This will cause high order of coefficient matrix of corresponding equation group.

有限元方法是工程学科的重要工具，被证明为在许多科学和工程领域中连续物理系统模拟的一种普遍方法，但缺点是随着工程结构分析问题越来越复杂，在结构分析中，为保证数值解的精度，在使用有限元方法离散处理时，往往要用大量的高阶单元将结构剖分得很密，这时相应的代数方程组的系数矩阵的阶数很高，即使用目前速度最快的串行机来进行求解，费时仍然太多且问题的规模受到内存容量的限制。

The key idea is to reduce the global stability problem to the asymptotic stability of an uncertain discrete-time system.

主要思想是将所研究的极限环的全局稳定性问题转化为不确定离散系统的渐近稳定性问题。

By means of generalized Lyapunov function and linear matrix inequality,the asymptotical stability with zero solution is studied for the system,and a sufficient condition is given such that the system is asymptotically stable with zero solution and also a H∞ norm constraint .

针对非线性离散广义系统研究了状态反馈H∞控制器的设计问题，利用广义Lyapunov函数和线性矩阵不等式，首先对系统的零解渐近稳定问题进行了研究，并在此基础上给出了系统的零解渐近稳定且具有H∞范数约束的充分条件，之后设计了状态反馈H∞控制器，使闭环系统具有同样的性能，最后给出了数值算例说明本文结论的有效性和可行性

With the new concept,the problem of variable structure control of 2D discrete system is transferred to the problem of seeking a sliding model with good sporting character and attractability. The concrete design schemes of the imitative sliding model and variable structure controller are also put forward. And the concrete expression of the time T in ε-neighborhood of reaching switch manifold is obtained. The difficulty of applying the existing methods to MIMO systems is overcome.

在新概念之下，将2D离散系统的变结构控制问题转化为寻找一个既具有良好的运动品质又具有吸引性的滑动模问题，给出了滑动模及变结构控制器的设计方案，并且获得了达到切换流形的ε领域的时间T的具体表达式，克服了已有方法难以应用到多输入—多输出系统上的困难。

Firstly establishing mechanical model of casing structure , and then processing casing forces analysis using space finite-element method and superposition method(put structure stress and outer force stress together), it computes the stress of casing in three dimensions, and gets the internal force and transmutation. The structure of casing-coadjutor is computed overlaply and the question of contact is solved. In the aspect of design, it provides the mixed integer-discrete variable optimization method of casing cross section size and coadjutor layout.

本文就上述两个问题的最优化设计展开研究，首先建立了套管结构的力学模型，进行套管的受力分析，用了空间有限元法和叠加法(结构应力和外载应力相叠加)，对套管进行三维计算，确定结构的内力和变形，对套管—扶正器结构进行整体的叠代计算，解决接触问题；在设计方面，提出了解决套管截面尺寸参数和扶正器布局的混合整数—离散变量优化方法。

The book covers such topics as the problem of collinearity in multiple regression, dealing with outlying and influential data, non-normality of errors, non-constant error variance and the problems and opportunities presented by discrete data.

本书内容涵盖了在多重共线性回归问题等议题，与外围和有影响的数据，非错误，非正常常数误差方差的问题和离散数据处理带来的机遇。

Then, according to Radau collocation method, the dynamic optimization problem is converted to a nonlinear programming one that contains continuous and discrete variables.

根据Radau配置法将动态优化问题转化为连续变量与离散变量并存的非线性规划问题。

According to Radau collocation method,the dynamic optimization problem can be converted to a nonlinear programming problem which contains both continuous and discrete variables.

根据Radau配置法将动态优化问题转化为连续变量与离散变量并存的非线性规划问题。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。