Convergence of five-point scheme with diagonally dominant characteristic for DLR k−ε model and its application

In this paper, the equivalent equations of DLR k−ε turbulent model in the boundary-fitted curvilinear coordinate are employed. Using the upwind idea that the contribution of the difference coefficients to the main node is positive contribution, and the other nodes are negative contribution or no contribution, new five-point difference schemes with a full diagonally dominant coefficient matrix (5-point-DD difference scheme) are constructed. Finally, taking the $\bar{u}$ equation in the DLR k−ε turbulent model as an example, the mathematical characteristics of the 5-point-DD difference scheme are analyzed, and the uniform boundedness and convergence theorems of the Gauss-Seidel iterative sequence are given. Numerical simulations show that the five-point schemes are strictly diagonally dominant, and the calculated results are in good agreement with the experimental results.     

Detecting overlapping communities in networks via dominant label propagation

Community detection is an important methodology for understanding the intrinsic structure and function of a realworld network.In this paper,we propose an effective and efficient algorithm,called Dominant Label Propagation Algorithm(Abbreviated as DLPA),to detect communities in complex networks.The algorithm simulates a special voting process to detect overlapping and non-overlapping community structure in complex networks simultaneously.Our algorithm is very efficient,since its computational complexity is almost linear to the number of edges in the network.Experimental results on both real-world and synthetic networks show that our algorithm also possesses high accuracies on detecting community structure in networks.     

考虑供应商服务与零售商退货的定价博弈分析

研究由一个供应商和一个零售商组成的二级供应链,由供应商提供产品服务,零售商制定产品零售价,在一个销售周期结束后存在零售商向供应商的退货,退货产生的物流成本由零售商与供应商通过博弈的方式共同分担.基于博弈理论,建立了供应商和零售商以各自利润最大化为目标,以服务水平、零售价和退货为主要影响因素的Nash和Stackelberg博弈.采用数值方法,对这两个博弈进行了求解.得到供应商为零售商分担退货物流成本最优比例、供应商最优服务水平和零售商最优定价策略.研究表明,Nash博弈时的解是唯一的,此时供应商不会分担退货物流成本;Stackelberg博弈时,供应商分担退货物流成本比例依据批发价大小而定.     

判定广义对角占优矩阵的一组新条件(英文)

本文给出了广义对角占优矩阵的新判定条件,改进了近期的相关结果,并用数值例子说明了所得结果判定范围的更加广泛性.     

具一组可修复设备的系统解的适定性和稳定性

研究具一组可修复设备的系统解的适定性和稳定性.使用泛函分析方法,特别是Banach空间上的线性算子理论和C_0半群理论,证明了系统解的适定性以及正解的存在性,证明了系统解的渐近稳定性,指数稳定性以及严格占优本征值的存在性,证实了实际问题中相关假设的合理性.     

板模型具广义边界条件的迁移算子的谱

研究具广义边界条件、非均匀介质、各向异性和连续能量的板模型迁移算子A的谱．证明了K=A-B的相对紧性，在L^1空间研究算子A的谱，以及占优本征值和严格占优本征值．     

广义严格对角占优矩阵与M矩阵的充分判据

In this paper, some criteria for generalized strictly diagonally dominant matrices and M-matrices are given. Some previous results are improved and generalized.     

主导因素法在燃气轮机建模中的应用

燃气轮机具有效率高、排放低、启停迅速、能量密度高等优势,在我国能源结构改善中起重要作用,天然气的大规模利用也为我国燃机技术的应用提供了机遇。而燃气轮机集成度高,高温部件工作环境恶劣,使得电站燃气轮机测点少,可获取现场运行数据有限。本文采用了主导因素法,基于MATLAB平台,建立了简单循环单轴燃气轮机数学模型,并以某典型M701F燃气轮机的现场运行数据进行了模型验证,结果表明本文所建模型可以较准确地反映燃气轮机性能。     

制造商主导下的CLSC物流策略和供应链稳定性

针对制造商主导的闭环供应链系统,考虑物流策略对系统的影响,运用博弈论理论,分析了物流外包和物流自营时制造商和零售商的定价策略、物流策略以及供应链稳定性.分析发现,无论是物流自营还是物流外包,随着补贴的增大,批发价格的单位变动率和单位再制造节约成本的单位变动率相等,但是方向相反.关于物流策略,无论补贴高低,只要fg1或者fg~21,则制造商和零售商在物流策略选择上始终一致,供应链具有长期稳定性.但若fg1fg~2,则制造商和零售商在物流选择上产生分歧,供应链具有不稳定性.     

On a matrix-based measure of the degree of coreness of a node in a network

The paper focuses on the right and left eigenvectors of a network matrix that belong to the largest eigenvalue. It is shown that each of vector entries measures the walk centrality of the corresponding node’s position in the network’s link structure and of the positions of the node’s adjacent nodes; as a result, it indicates to which degree the node can be associated with the structure’s core, i.e., the structural coreness of the node. The relationship between the vectors’ coordinates and the position of the nodes, as well as the actual computation of the coordinates, is based on an iterative computational scheme known as the power method. The paper studies the method’s convergence for networks of different structure. Some possible applications are discussed. The paper also includes a numerical example dealing with a real network of 197 nodes and 780 links.