Neumann型约束Tu流的r矩阵和分离变量

本文发展了适用于Neumann型约束流的r矩阵方法．研究了Neumann型约束Tu流．获得了Neumann型约束Tu流的Lax表示；证明了在Dirac括号下这个Lax算子满足r矩阵关系，从而再次证明了Neumann型约束Tu流是Liouville完全可积的．另外，还利用r矩阵关系，找到了这个Neumann型约束流的一组正则变量，从而把Neumann型约束Tu流线性化．     

双约束孤立子流的可积形变

提出了基于Lax矩阵的构造双约束孤立子流的可积形变的新方法.作为应用,导出了双约束KdV流和双约束mKdV流的可积形变,并给出了这些形变的Lax表示、r-矩阵和守恒积分.     

双约束孤立子流的可积形变

提出了基于Lax矩阵的构造双约束孤立子流的可积形变的新方法.作为应用,导出了双约束KdV流和双约束mKdV流的可积形变,并给出了这些形变的Lax表示、r-矩阵和守恒积分.     

AKNS族与Geng族的规范等价的约束流

先由ＡＫＮＳ族出发用规范变换建立了Ｇｅｎｇ族的约束流及它的第一组守恒积分和Ｌａｘ表示,再用其Ｌａｘ表示建立了Ｇｅｎｇ族约束流的ｒ－矩阵。并且还给出了Ｇｅｎｇ族约束流的第二组守恒积分及其对合性的证明。     

关于AKNS族和一个耦合的MKdV族的规范等价可积系统与r-矩阵

得到了一个新的耦合的MKdV族．通过规范变换，首次从AKNS族中得到耦合的MKdV族的Lax表示、可积系与约束流；利用Lax表示，构造了耦合MKdV族的约束流的γ-矩阵，同时也给出了该方程族约束流的第二组守恒积分与对合性．     

由伴随坐标建立可积约束流

引入伴随坐标，把ＡＫＮＳ族与经典Ｂｏｕｓｓｉｎｅｓｑ族的某些高阶约束流变换到有限维可积 Ｈａｍｉｌ－ｔｏｎｉａｎ系统，并给出这些约束流的经典Ｐｏｉｓｓｏｎ结构和卜矩阵．本文还证明了ＡＫＮＳ族的约束流在Ｌｉｏｕｖｉｌｌｅ意义下是可积的．     

一类受时间约束的广义运输问题的求解

研究一类受时间约束的广义运输问题,将时间约束转化为容量约束,并将该问题转化为标准的最小费用流问题进而求解.该方法能够较快地找到最优运输方案.     

Tu方程族的高阶双约束流的分离变量

本文给出了Tu方程族的高阶双约束流,其自由度为2N＋l。根据通常的办法,利用Lax矩阵仅能引入N＋l对标准分离变量和N＋l个分离变量方程。本文构造出另外N对分离变量及N个分离变量方程。此外,还建立了双约束流和Tu方程族的Jacobi反演问题。     

血液自然分布单位全面血液关系流的实现与维护

在全面关系流管理理论的基础上,研究人体血液自然分布单位组织全面血液关系流的实现与维护.实现关系流应该从关系流的性质、时间约束、血液自然分布单位的状态与行为,以及可行性等方面综合考虑.当全面关系流建立起来后,人体组织就基于血液关系流建立起自然法则,当血液关系流不再适用时,相关的血液自然分布单位需进行关系流的再设计,以适应新的组织行为.     

网络流问题的病态网络分析

对供需运输系统中的网络流问题,由于供需约束或容量配置不合理,有时会出现一种反常现象:对一个最优运输方案来说,即使供需量或容量限制增加,多运了货物,运费反而下降.这种违背常理的现象反映出网络结构的失衡或畸形,迫使最优方案产生扭曲逆转,这种现象可称之为"病态".在运输问题的特殊情形(无容量约束的最小费用流问题),文献中已有过讨论,称为"运输问题悖论",对一般的网络流问题,研究三种类型的病态:供需约束、容量配置及结构上的病态,并给出判定条件和判别算法,最终引导到网络改造问题.     

New hierarchy of integrable system bi-Hamiltonian structure and constrained flows

We have considered the hierarchy of integrable systems associated with the unstable nonlinear Schrodinger equation. The spectral gradient approach and the trace identity are used to derive the bi-Hamiltonian structure of the system. The bi-Hamiltonian property and the square eigenfunctions determined via the spectral gradient approach are then used to construct constrained flows, which is also proved to be derivable from a rational Lax operator. This new Lax operator of the constrained flows is seen to generate the classical r-matrix. Lastly it is also explicitly demonstrated that the different integrals of motion of the constrained flows Poisson commute.     

Binary nonlinearization of spectral problems of the perturbation AKNS systems

The method of nonlinearization of spectral problems is extended to the perturbation AKNS systems, and a new kind of finite-dimensional Hamiltonian systems is obtained. It is shown that the obtained Hamiltonian systems are just the perturbation systems of the well-known constrained AKNS flows and thus their Liouville integrability is established by restoring from the Liouville integrability of the constrained AKNS flows. As a byproduct, the process of binary nonlinearization of spectral problems and the process of perturbation of soliton equations commute in the case of the AKNS hierarchy.     

多向量Kaup-Newell方程的一个可积分解

本文中,我们从一个高阶的方阵谱问题出发得到多向量Kaup-Newell方程的一个可积分解．通过迹恒等式的帮助,得到多向量Kaup-Newell方程族的双哈密顿结构,而且可以发现这个多向量Kaup-Newell方程的时间部分和空间部分的约束流是刘维尔意义下的两个可积哈密顿系统．     

Aggregation-diffusion to constrained interaction: Minimizers & gradient flows in the slow diffusion limit

Inspired by recent work on minimizers and gradient flows of constrained interaction energies, we prove that these energies arise as the slow diffusion limit of well-known aggregation-diffusion energies. We show that minimizers of aggregation-diffusion energies converge to a minimizer of the constrained interaction energy and gradient flows converge to a gradient flow. Our results apply to a range of interaction potentials, including singular attractive and repulsive-attractive power-law potentials. In the process of obtaining the slow diffusion limit, we also extend the well-posedness theory for aggregation-diffusion equations and Wasserstein gradient flows to admit a wide range of nonconvex interaction potentials. We conclude by applying our results to develop a numerical method for constrained interaction energies, which we use to investigate open questions on set valued minimizers.     

Commutativity of the extended KP flows

The commutativity problem of the extended KP hierarchy is analyzed. The compatibility equation of two extended KP flows is constructed, together with its Lax representations involving two extended Lax operators. The resulting theory shows that the extended KP hierarchy is a natural generalization of the KP flows, but does not commute unlike the constrained KP hierarchy. A few particular examples are computed, along with their Lax pairs.     

多分量AKNS方程的新可积分解

从一个任意阶矩阵谱问题出发,多分量AKNS方程的新可积分解被导出.通过利用迹恒等式建立了其双哈密顿结构.同时,证明了空间与时间的约束流在刘维尔意义下是两个完全可积的哈密顿系统.     

Guo族约束流的经典Poisson结构、Lax表示、r-矩阵和Liouville可积性

基于伴随表示,通过引入Ｊａｃｏｂｉ－Ｏｓｔｒｏｇｒａｄｓｋｙ坐标,获得了Ｇｕｏ族约束流的Ｌａｘ表示,Ｐｏｉｓｓｏｎ结构和ｒ－矩阵,最后,借助Ｐｏｉｓｓｏｎ结构和ｒ－矩阵,说明了Ｇｕｏ族约束 是Ｌｉｏｕｖｉｌｌｅ可积的。     

Performance of the heuristic procedures for constrained projects with progress payments

All large scale resource constrained projects involve cash flows occurring during their life cycle. Several recent studies consider the problem of scheduling projects to maximise the net present value (NPV) of these cash flows. Their basic common assumption is that cash flows are mainly associated with specific events and they occur at event realisation times. An alternative assumption, which can be more realistic, is that cash inflows occur periodically, for example every month, as progress payments. This article considers the problem of maximising NPV given the alternative assumption. Three different heuristic rules are developed. The performance of these heuristic rules is analysed through a full factorial experiment with 108 scheduling conditions. The results indicate that three rules provide near-optimal schedules with respect to NPV maximisation while producing time schedules that do not delay the project completion time extensively.