Decomposition Theorems for Semi-order Fuzzy Supermartingales and Submartingales

Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-composition theorems of standard martingale theory tosemi - order fuzzy supermaringales and submartingales.The structure of semi - order fuzzy supermaringales andsubmartingales and the conditions of that they has Doobdecomposition (resp. Riesz decomposition) are discussedin detail.

Semi-order Fuzzy Supermartingales and Submartingales

There are some mathematical models(see Example2.4)and analogous results in standard martingale theorywhich can not be described by the usual fuzzy martingaletheory because of the lack of corresponding semi-orderin the fuzzy number space(E^n,D).In this paper,asuitable semi-order in the fuzzy number space(E^n,D)and the semi-order fuzzy supermartingale and submar-tingale are introduced,the charaterlstics of semi-ordersupermartingales and submartingales,as well as theDood’s stopping theorem for them(the bounded stoppingtimes theorem and the general stopping times theoremfor a class of closable semi-order fuzzy supermartin-gales and submartingales)are established.

偏序半群的商序同态研究

通过偏序半群的商半拟序、商半拟链和正则同余,研究了偏序半群的商序同态,给出了偏序半群的商序同态基本定理。同时,讨论了偏序半群的商半拟序与商序同态之间的关系,给出了由偏序半群S到T的商序同态φ构造S的商半拟序ρ_φ的方法以及S的一个商半拟序ρ?ρ_φ的充分必要条件,并得到了一些重要结论。

基于高阶半解析移动脉动源法的船舶波浪增阻数值计算研究

在三维势流理论框架下,以移动脉动源格林函数为核函数构建边界积分方程,采用九节点高阶曲面单元进行离散求解速度势,建立了波浪中航行船舶运动响应和波浪增阻的计算模型.为了避免数值计算的不稳定,积分方程中的影响系数采用了半解析公式进行计算.求解波浪增阻时,采用将辐射能量法、Salvensen法和短波半经验公式相结合的混合法,以便能够在全频率范围内得到令人满意的结果.在此基础上,自主开发数值程序对不同船型在不同频率、航速下的运动响应和波浪增阻进行预报.通过将预报值与试验及其它数值方法的结果进行对比发现,文中方法的数值结果与试验值吻合良好,对于不同船型和工况均有着良好的适用性;相比传统基于数值求积公式的移动脉动源法,高阶半解析移动脉动源法计算更为稳定(尤其对于存在外飘的船型),且由于采用了高阶格式,在共振频率附近的预报精度比常值元法更高.

具有混合约束半无限规划的高阶(ϕ,ρ)-V-不变凸性和对偶性

在半无限规划问题中,凸性的推广和对偶模型的建立是两个非常重要的组成部分.本文引入一类高阶(ϕ,ρ)-V-不变凸函数,并在高阶(ϕ,ρ)-V-不变凸性的假设下,研究一类具有混合约束的半无限规划问题,构造Wolfe型和Mond-Weir型对偶,得到相应的弱、强和严格逆对偶定理.

非光滑半无限多目标优化的高阶KKT最优性充分条件

考虑了一类非光滑半无限多目标优化问题.利用高阶Studniarski下导数,得到了问题的严格局部有效解的高阶弱KKT最优性充分条件.进一步地,若假设该最优性条件中目标函数相关的乘子均大于零,则得到严格局部Borwein真有效解的高阶强KKT充分条件.这些充分条件适用于处理无任何凸性假设下的问题.

基于半量子安全直接通信的量子拍卖协议

针对现有量子密封拍卖协议中存在的报价隐私保护不够、恶意竞标者与第三方共谋等问题,提出了一种基于半量子安全直接通信的量子密封投标拍卖协议。该协议采用半量子安全直接通信,通信时拍卖方仅需拥有测量和反射粒子的能力;通过对投标方报价的保序加密,实现对报价的隐私保护;利用隐私比较,在无第三方参与的情况下,拍卖方也能比较保序加密后的报价信息。理论分析表明面对截获-重发、受控非门(CNOT)、相位反转、共谋等攻击时,所提出协议仍具有较高的安全性,且与同类型量子拍卖协议相比,新协议通信效率不受投标人数的影响。

小说《天龙八部》的“生命实践诠释学”——以逍遥派为例

以金庸小说《天龙八部》中逍遥派情节为例,从理论与实践两方面诠释了逍遥派与老庄玄思、道家哲学的嬗变顺承关系,即秉承自然观与隐逸之道,立身行事遗世越俗、卓诡不伦,由此生成“守自然、卧东山、游浊世”的终极诠释,体现了金庸以自身哲思对老庄之道的生动诠释与现实雕琢,即“生命实践诠释学”。此外,通过分析逍遥三老“畸人”的特征,揭示了金庸将西方反讽哲学与老庄之戏谑意识及讥嘲情趣相融合的独特艺术创造,这亦是金庸对人性纷繁多面与老庄生命哲学奥义的革新探索与反向诠释。

面向海上风电仿真的永磁同步发电机电磁暂态等效建模方法

海上风电的建模与仿真是构建新能源为主体的新型电力系统的关键支撑技术。永磁同步发电机(PMSG)作为直驱或半直驱机型的核心元件,现有模型存在一定的局限性:商业软件提供的灰箱模型无法得知建模原理,开放程度不够,限制了风电机组应用高效电磁暂态建模算法与并行加速算法;目前常用的PMSG建模方法无法生成接口与外电路连接;PMSG是同步发电机的一种,而同步发电机有不同阶数的数学模型,现有模型不便更改。针对上述问题,该文提出阶数可选的PMSG电磁暂态等效建模方法。首先对发电机电压、磁链方程进行离散化;然后通过单步长延时消除代数环,重构PMSG模型,推导得到其诺顿等效电路并构建模型整体仿真框架;最后,在RTDS仿真平台中进行仿真分析。结果表明四阶、二阶模型在场站级仿真具有适用性,而六阶模型实现了对基准模型的多工况高度拟合,平均相对误差小于4%,能够同时满足场站级与机组内部各仿真需求。

基于联邦学习的自助取货机远程下单数据共享方法

研究了基于联邦学习的自助取货机远程下单数据共享方法。精准有效共享自助取货机各端口运营中的下单数据,为有效分析各端口营销差异、保障其合理运营提供依据。运用自编码神经网络改进基础联邦学习模型,获得半监督联邦学习模型,结合增量加权训练该模型后,运用训练后的半监督联邦学习模型共享各自助取货机端口的远程下单数据。结果显示,该方法可有效共享各远程自助取货机端口的下单数据,依据共享数据可有效分析出各端口不同时段的畅销品类;当共享中存在无标记数据端口,且通信轮数较低时,该方法的共享精度略受影响,而通信轮数到达一定数量后,该方法的共享精度稳定不受此因素干扰;当共享中存在端口新增下单数据时,新增的下单数据量对该方法的共享精度几乎无影响。

广州市预制菜市场调查——以鸡肉半成品为例

随着预制菜产业的快速发展,开展与预制菜行业发展相关的学术研究和实践,具有重要的现实意义。预制菜中占比最大的是鸡肉半成品,为研究其市场情况,本文以广州市年轻消费者为研究对象,以问卷调查数据为基础,运用聚类分析、多重对应分析、多元有序logtic回归分析等方法进行研究、检验。结果显示:(1)对于鸡肉加工类产品,年轻消费者重视营销与食品安全;(2)主要消费人群对于产品的要求较高,同时主力顾客产品的态度很低,认为产品的品牌不够硬、烹饪不方便。基于此,本文建议:(1)鸡肉加工类产品要确保食品安全;(2)破圈营销提升品牌大众认知度;(3)树立品牌形象,满足消费者的产品要求。本文通过研究具体分析了广州地区鸡肉半成品的市场情况并形成相关建议,以期助力于广州预制菜市场的健康发展。

An improved semi-implicit direct kinetics method for transient analysis of nuclear reactors

Semi-implicit direct kinetics(SIDK)is an innovative method for the temporal discretization of neutronic equations proposed by J.Banfield.The key approximation of the SIDK method is to substitute a timeaveraged quantity for the fission source term in the delayed neutron differential equations.Hence,these equations are decoupled from prompt neutron equations and an explicit analytical representation of precursor groups is obtained,which leads to a significant reduction in computational cost.As the fission source is not known in a time step,the original study suggested using a constant quantity pertaining to the previous time step for this purpose,and a reduction in the size of the time step was proposed to lessen the imposed errors.However,this remedy notably diminishes the main advantage of the SIDK method.We discerned that if the original method is properly introduced into the algorithm of the point-implicit solver along with some modifications,the mentioned drawbacks will be mitigated adequately.To test this idea,a novel multigroup,multi-dimensional diffusion code using the finitevolume method and a point-implicit solver is developed which works in both transient and steady states.In addition to the SIDK,two other kinetic methods,i.e.,direct kinetics and higher-order backward discretization,are programmed into the diffusion code for comparison with the proposed model.The final code is tested at different conditions of two well-known transient benchmark problems.Results indicate that while the accuracy of the improved SIDK is closely comparable with the best available kinetic methods,it reduces the total time required for computation by up to 24%.

Heat transfer of nanofluids considering nanoparticle migration and second-order slip velocity

The heat transfer of a magnetohydrodynamics nanofluid inside an annulus considering the second-order slip condition and nanoparticle migration is theoret-ically investigated. A second-order slip condition, which appropriately represents the non-equilibrium region near the interface, is prescribed rather than the no-slip condition and the linear Navier slip condition. To impose different temperature gradients, the outer wall is subjected to q2, the inner wall is subjected to q1, and q1 〉 q2. A modified two-component four-equation non-homogeneous equilibrium model is employed for the nanofiuid, which have been reduced to two-point ordinary boundary value differential equations in the consideration of the thermally and hydrodynamically fully developed flow. The homotopy analysis method （HAM） is employed to solve the equations, and the h-curves are plotted to verify the accuracy and efficiency of the solutions. Moreover, the effects of the physical factors on the flow and heat transfer are discussed in detail, and the semi-analytical relation between NUB and NBT is obtained.

EXACT BOUNDARY CONTROLLABILITY FOR HIGHER ORDER QUASILINEAR HYPERBOLIC EQUATIONS

By means of the existence and uniqueness of semi-global C1 solution to the mixed initial-boundary value problem with general nonlinear boundary conditions for first order quasilinear hyperbolic systems with zero eigenvalues,the local exact boundary controllability for higher order quasilinear hyperbolic equations is established.

A Semi-Vectorial Hybrid Morphological Segmentation of Multicomponent Images Based on Multithreshold Analysis of Multidimensional Compact Histogram

In this work, we propose an original approach of semi-vectorial hybrid morphological segmentation for multicomponent images or multidimensional data by analyzing compact multidimensional histograms based on different orders. Its principle consists first of segment marginally each component of the multicomponent image into different numbers of classes fixed at K. The segmentation of each component of the image uses a scalar segmentation strategy by histogram analysis;we mainly count the methods by searching for peaks or modes of the histogram and those based on a multi-thresholding of the histogram. It is the latter that we have used in this paper, it relies particularly on the multi-thresholding method of OTSU. Then, in the case where i) each component of the image admits exactly K classes, K vector thresholds are constructed by an optimal pairing of which each component of the vector thresholds are those resulting from the marginal segmentations. In addition, the multidimensional compact histogram of the multicomponent image is computed and the attribute tuples or ‘colors’ of the histogram are ordered relative to the threshold vectors to produce (K + 1) intervals in the partial order giving rise to a segmentation of the multidimensional histogram into K classes. The remaining colors of the histogram are assigned to the closest class relative to their center of gravity. ii) In the contrary case, a vectorial spatial matching between the classes of the scalar components of the image is produced to obtain an over-segmentation, then an interclass fusion is performed to obtain a maximum of K classes. Indeed, the relevance of our segmentation method has been highlighted in relation to other methods, such as K-means, using unsupervised and supervised quantitative segmentation evaluation criteria. So the robustness of our method relatively to noise has been tested.

A direct proof of uniqueness of square-root of a positive semi-definite tensor

Understanding of the basic properties of the positive semi-definite tensor is a prerequisite for its extensive applications in theoretical and practical fields, especially for its square-root. Uniqueness of the square-root of a positive semi-definite tensor is proven in this paper without resorting to the notion of eigenvalues, eigenvectors and the spectral decomposition of the second-order symmetric tensor.

The Symbolic OBDD Algorithm for Finding Optimal Semi-matching in Bipartite Graphs

The optimal semi-matching problem is one relaxing form of the maximum cardinality matching problems in bipartite graphs, and finds its applications in load balancing. Ordered binary decision diagram (OBDD) is a canonical form to represent and manipulate Boolean functions efficiently. OBDD-based symbolic algorithms appear to give improved results for large-scale combinatorial optimization problems by searching nodes and edges implicitly. We present novel symbolic OBDD formulation and algorithm for the optimal semi-matching problem in bipartite graphs. The symbolic algorithm is initialized by heuristic searching initial matching and then iterates through generating residual network, building layered network, backward traversing node-disjoint augmenting paths, and updating semi-matching. It does not require explicit enumeration of the nodes and edges, and therefore can handle many complex executions in each step. Our simulations show that symbolic algorithm has better performance, especially on dense and large graphs.

Conservative and Easily Implemented Finite Volume Semi-Lagrangian WENO Methods for 1D and 2D Hyperbolic Conservation Laws

The paper is devised to propose finite volume semi-Lagrange scheme for approximating linear and nonlinear hyperbolic conservation laws. Based on the idea of semi-Lagrangian scheme, we transform the integration of flux in time into the integration in space. Compared with the traditional semi-Lagrange scheme, the scheme devised here tries to directly evaluate the average fluxes along cell edges. It is this difference that makes the scheme in this paper simple to implement and easily extend to nonlinear cases. The procedure of evaluation of the average fluxes only depends on the high-order spatial interpolation. Hence the scheme can be implemented as long as the spatial interpolation is available, and no additional temporal discretization is needed. In this paper, the high-order spatial discretization is chosen to be the classical 5th-order weighted essentially non-oscillatory spatial interpolation. In the end, 1D and 2D numerical results show that this method is rather robust. In addition, to exhibit the numerical resolution and efficiency of the proposed scheme, the numerical solutions of the classical 5th-order WENO scheme combined with the 3rd-order Runge-Kutta temporal discretization (WENOJS) are chosen as the reference. We find that the scheme proposed in the paper generates comparable solutions with that of WENOJS, but with less CPU time.

永磁直线同步电机自适应分数阶终端滑模控制

针对永磁直线同步电机的位置跟踪性能易受负载扰动、动子质量变化等不确定性的影响,提出一种基于半正定屏障函数的自适应分数阶终端滑模控制策略。首先,采用分数阶终端滑模控制方法来抑制不确定性对系统的影响,保证了跟踪误差在有限时间收敛,且能够有效地减小系统稳态误差。然后,为了进一步改善系统鲁棒跟踪性能,设计基于半正定屏障函数的自适应控制对不确定扰动的上界进行估计,避免了控制增益的过高估计且削弱了系统抖振。此外,该自适应策略在不需要外界扰动先验信息的情况下,可以使得系统误差收敛到一个预定的零邻域内。最后,实验结果表明,该策略提高了系统的跟踪精度,对负载扰动和附加有效载荷具有较强鲁棒性。

基于数据挖掘的输电断面动态极限传输功率在线构建方法

随着风电等间歇性新能源的大规模并网,电网运行状态变化频繁,传统基于典型运行方式计算的输电断面极限传输功率(Total Transfer Capability,TTC)适用性降低。文中提出一种基于数据挖掘的输电断面动态TTC在线构建方法。首先,基于风电和负荷的超短期预测及预测误差的高阶不确定性,采样生成“风电-负荷”二维数组及相应运行状态集,对部分运行状态计算其TTC,获得用于构建输电断面动态TTC的有标记/无标记知识库;然后,通过混合互信息法选择出与TTC存在强关联的特征属性;最后,利用半监督协同训练,建立TTC偏差与特征属性之间的定量关系,进而得到输电断面动态TTC。算例验证表明,该方法不仅能够基于超短期预测及预测误差的不确定性准确估计输电断面TTC,而且能够量化提供提高TTC的调度信息,同时,采用半监督数据挖掘技术,减少了计算TTC的次数,构建动态TTC速度快,能够较好的适应在线运行方式。