含参集值弱向量平衡问题解集映射的半连续性

在线性度量空间中,运用标量化技巧在没有单调性与C-凹性假设下得到了含参集值弱向量平衡问题解集映射上/下半连续性的充分性条件.所得结果改进了已有文献的相应结果,并通过例子验证了所得结果.     

无结构网格有限体积方法及在热对流中的应用研究

首次将无结构三角网格的有限体积方法和压强连接半隐式算法相结合 ,用于求解非平行壁管道中的热对流问题 .并由此分析了化学汽相淀积薄膜生长的均匀性问题 .计算结果对于分析一类管道中热和动量输运现象均有普遍指导意义     

同位网格界面速度插值方法研究

讨论了同位网格下,离散的连续性方程、动量方程及标量方程中控制容积界面上速度的计算方法．分别采用动量插值技术和线性插值技术计算了动量方程和标量方程的离散系数中的界面速度,并将两种方法得到的计算结果进行了比较．指出当采用线性插值技术去计算离散方程系数中的界面速度时,离散系数中的质量残余必须等于0,这样才能保证数值解的准确性和计算的收敛速度．     

参数弱向量平衡问题解集映射的连续性

运用非线性标量化方法, 讨论参数弱向量平衡问题解集映射的上半连续性和下半连续性, 并举例说明了所得结果的正确性.     

重建极性连续统理论的基本定律和原理(Ⅵ)——质量和惯性守恒定律

重建极性连续统理论的耦合型质量和惯性的守恒定律和局部守恒方程以及跳变条件.为此推导出新的变形梯度、线元、面元和体元的物质导数,并给出广义Reynolds输运定理.把这些结果和作者以前推导出的耦合型动量、动量矩和能量的基本定律和有关原理结合在一起就大体上构成极性连续统理论相当完整的耦合型基本定律、局部守恒和均衡方程及原理体系.从此体系可以根据常用的局部化方法给出耦合型的非局部质量和惯性守恒方程以及动量、动量矩和能量均衡方程.     

Hilbert空间中关于变分不等式问题和不动点问题的粘性隐式中点算法

该文在Hilbert空间中研究了关于两个逆强单调算子的一般变分不等式问题和非扩张映射的不动点问题的粘性隐式中点算法,用修改的超梯度方法,在对参数作适当的限制下,得到了强收敛定理,所得结果推广和提高了许多最新文献中的相应结果.     

多元系稀薄气体的输运理论和氮在高温下的输运性质

本文应用Grad的十三矩量方法,讨论有电磁场、重力场作用的多元系稀薄气体中的输运现象,得到了Boltzmann方程的近似解和计算输运系数的公式.所得结果,在特定条件下与Chapman,Enskog与Hirschfelder等人所得的理论结果一致.文中并提出了一个计算部分电离气体电导率的公式。文中还计算了氮气由室温至8000K的粘滞系数、由室温至20000K的导热系数和由8000 K至20000 K的电导率.计算结果与实验结果表明两者符合是基本满意的。     

Hilbert空间上新的变分不等式问题和不动点问题的粘性迭代算法

本文在Hilbert空间上引入了一个新的粘性迭代算法,找到了关于两个逆强单调算子的变分不等式问题的解集与非扩张映射的不动点集的公共元.通过修改的超梯度算法,得到了强收敛定理,也给出了一个数值例子.所得结果改进了许多最新结果.     

Pi-sigma神经网络的带动量项的异步批处理梯度算法收敛性

本文将动量项引入到训练Pi-sigma神经网络的异步批处理的梯度算法中,有效的改善了算法的收敛效率,并从理论上对该算法的收敛性进行研究,给出了误差函数的单调性定理及该算法的弱收敛和强收敛性定理.计算机仿真实验亦验证了带动量项的异步批处理梯度算法的有效性和理论分析的正确性.     

正线性算子的Young型逆不等式的一个改进（英文）

本文研究了正线性算子的Young型逆不等式的问题.利用算子单调函数以及凸函数的性质,获得了若干带有Kantorovich常数的Young型逆不等式标量形式及相对应的正线性算子的Young型逆不等式的改进形式,推广了现有文献中的结论.     

Numerical Simulation of Air Flow in Model Room

Efficient, and appropriate indoor air environment is important issue in building design. Air flow patterns which are formed in the room are mainly depended on its geometrical parameters. Investigation of flow patterns are performed on a relatively simple geometry of model room, with a small obstacle (partition) in it. There are several interesting flow phenomena which are present in the model room: flow through sudden geometry expansion, stagnation flow with lateral boundaries, flow over the obstacle, etc. Since the air velocities are low, it is assumed that flow is incompressible. Numerical calculations of these patterns have been done using RANS modeling approach. For all calculations an extended version of open-source CFD software OpenFOAM was used. Several turbulence models have been used for RANS approach, with special attention on their performance in capturing unsteady flow phenomena. Comparison of obtained numerical results and available experimental results for mean velocities shown good agreement. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Heat and mass transfer in liquid desiccant air-conditioning process at low flow conditions

This paper investigates the transient heat and mass transfer in liquid desiccant air-conditioning process at low flow conditions. Using local volumetric average approach, one-dimensional non-equilibrium heat and mass transfer models are developed to describe the humid air and liquid desiccant interaction at counter flow configuration. Using triethylene glycol solution as desiccant, some experimental studies are completed. Experimental results are used to justify the numerical models. Numerical results are then obtained to demonstrate process characteristics. The models include a transient desiccant flow model for initial liquid desiccant building-up process, empirical wetted specific surface ratio for mass transfer, and heat and mass transfer coefficients. The objective of this research is to develop a process analytical tool for liquid desiccant air-conditioner design.     

Sensitivity analysis for the asymmetric network equilibrium problem

We consider the asymmetric continuous traffic equilibrium network model with fixed demands where the travel cost on each link of the transportation network may depend on the flow on this as well as other links of the network and we perform stability and sensitivity analysis. Assuming that the travel cost functions are monotone we first show that the traffic equlibrium pattern depends continuously upon the assigned travel demands and travel cost functions. We then focus on the delicate question of predicting the direction of the change in the traffic pattern and the incurred travel costs resulting from changes in the travel cost functions and travel demands and attempt to elucidate certain counter intuitive phenomena such as ‘Braess' paradox’. Our analysis depends crucially on the fact that the governing equilibrium conditions can be formulated as a variational inequality. This work was supported by the Program of University Research, U.S. Department of Transportation (Project number DTRS 5680-C-00007).     

A numerical scheme for regularized anisotropic curve shortening flow

Realistic interfacial energy densities are often non-convex, which results in backward parabolic behavior of the corresponding anisotropic curve shortening flow, thereby inducing phenomena such as the formation of corners and facets. Adding a term that is quadratic in the curvature to the interfacial energy yields a regularized evolution equation for the interface, which is fourth-order parabolic. Using a semi-implicit time discretization, we present a variational formulation of this equation, which allows the use of linear finite elements. The resulting linear system is shown to be uniquely solvable. We also present numerical examples.     

A network model for airport common use check-in counter assignments

The purpose of flight to check-in counter assignments is to assign each flight to specific check-in counters where the airline will provide passenger check-in services. The number of common use check-in counters required for daily operations is an important issue closely related to the airport's level of service and system performance. In this study, a new network model is developed for the optimization of common use check-in counter assignments. The goal is to minimize the number of counters required for daily operations. Numerical tests are performed on data for a major Taiwan airport. The obtained results show that the model performs well.     

Geometric evolution equations in critical dimensions

We make a qualitative comparison of phenomena occurring in two different geometric flows: the harmonic map heat flow in two space dimensions and the Yang–Mills heat flow in four space dimensions. Our results are a regularity result for the degree-2 equivariant harmonic map flow, and a blow-up result for an equivariant Yang–Mills-like flow. The results show that qualitatively differing behaviours observed in the two flows can be attributed to the degree of the equivariance.     

Exact analytical solutions for the Poiseuille and Couette-Poiseuille flow of third grade fluid between parallel plates

Exact analytical solutions for the velocity profiles and flow rates have been obtained in explicit forms for the Poiseuille and Couette-Poiseuille flow of a third grade fluid between two parallel plates. These exact solutions match well with their numerical counter parts and are better than the recently developed approximate analytical solutions. Besides, effects of various parameters on the velocity profile and flow rate have been studied.     

Series solutions of nano boundary layer flows by means of the homotopy analysis method

We present here a ‘similar’ solution for the nano boundary layer with nonlinear Navier boundary condition. Three types of flows are considered: (i) the flow past a wedge; (ii) the flow in a convergent channel; (iii) the flow driven by an exponentially-varying outer flows. The resulting differential equations are solved by the homotopy analysis method. Different from the perturbation methods, the present method is independent of small physical parameters so that it is applicable for not only weak but also strong nonlinear flow phenomena. Numerical results are compared with the available exact results to demonstrate the validity of the present solution. The effects of the slip length ?, the index parameters n and m on the velocity profile and the tangential stress are investigated and discussed.     

Applying a non-equilibrium wall function in k–ε turbulent modelling of hydrodynamic circulating flow

Wall bounded flow with severe adverse pressure, separation, reattachment and stagnation has non-equilibrium (NE) exhibition. A wall function in turbulent flow is a remedy to avoid resolving near wall complex phenomena using predetermined functions as boundary conditions. The advantage of this case is permission to use a relatively coarse near wall cells and hence saving CPU time. Standard wall function (SWF) is a semi-empirical function that is just valid for constant shear near wall cell and local equilibrium flow. Popovac and Hanjalic introduced a non-equilibrium wall function as (PWF) with a blending method in v²–f model. To investigate PWF in circulating flow, standard k–ε model that has key role in complex and expensive industrial problems is used in this study. The approach derived by Popovac and Hanjalic retains the functional form of the SWF and can be easily implemented in existing code. Simulation results are validated against direct numerical simulation (DNS) on channel and experimental data on backward facing step (BS) and a sharp U bend flow. Prediction with PWF shows that use of this wall function in k–ε model has not any sensitive change in near equilibrium flow. However, produces an improvement in NE conditions like flow in circulation zones.     

Some results for secondary processes generated by a poisson process

We obtain the moment structure of a general class of random variables generated by a Poisson process. We then apply these relationships to several applied probability models. Among these are queues, counter models and low density traffic flow.