北内环清管过程中清管球滞留问题研究

为保证北内环平稳、高效、安全输送天然气,对其进行清管通球。在清管过程中出现3次清管球滞留情况,针对这些滞留情况,从清管球在管道中的受力情况、清管球在三通处出现形状变化2个方面分析讨论了清管球滞留原因;从建立较大背压发球、增加清管球过盈量、改变三通倾斜方向3个方面来研究解决问题的方法,证明均不符合实际情况;通过对比清管球、皮碗清管器、泡沫清管器3种设备的优缺点,最后选择泡沫清管器为北内环清管最优的清管器材。     

A link-node complementarity model and solution algorithm for dynamic user equilibria with exact flow propagations

In this paper, we propose a link-node complementarity model for the basic deterministic dynamic user equilibrium (DUE) problem with single-user-class and fixed demands. The model complements link-path formulations that have been widely studied for dynamic user equilibria. Under various dynamic network constraints, especially the exact flow propagation constraints, we show that the continuous-time dynamic user equilibrium problem can be formulated as an infinite dimensional mixed complementarity model. The continuous-time model can be further discretized as a finite dimensional non-linear complementarity problem (NCP). The proposed discrete-time model captures the exact flow propagation constraints that were usually approximated in previous studies. By associating link inflow at the beginning of a time interval to travel times at the end of the interval, the resulting discrete-time model is predictive rather than reactive. The solution existence and compactness condition for the proposed model is established under mild assumptions. The model is solved by an iterative algorithm with a relaxed NCP solved at each iteration. Numerical examples are provided to illustrate the proposed model and solution approach. We particularly show why predictive DUE is preferable to reactive DUE from an algorithmic perspective.     

评估设备激励特性的虚拟力方法研究

在结构声传播和声场响应研究中,往往需要以设备的激励特性作为计算模型的输入。若虚拟力作用下的结构响应与真实响应一致,可用虚拟力代替真实激励作为模型输入。文章在前人虚拟力模型的基础上结合改进的分部优化正则化方法,解决测量导纳矩阵的病态问题,提高虚拟力估算精度。文中通过电机模型实验对比了不同正则化方法下虚拟力对结构响应的重构误差,验证文中方法在虚拟力估算中的可行性和准确性。     

用单亲遗传算法求解配送车辆调度问题的研究

建立了配送车辆调度问题的数学模型，针对传统遗传算法对复杂问题搜索效率低，易陷入“早熟收敛”的缺点，构建了求解配送车辆调度问题的单亲遗传算法，并进行了实验计算。计算结果表明，用单亲遗传算法求解配送车辆调度问题，可以取得比传统遗传算法更优的结果。     

Multiple criteria optimization method for the vehicle assignment problem in a bus transportation company

A vehicle assignment problem (VAP) in a road, long‐haul, passenger transportation company with heterogeneous fleet of buses is considered in the paper. The mathematical model of the VAP is formulated in terms of multiobjective, combinatorial optimization. It has a strategic, long‐term character and takes into account four criteria that represent interests of both passengers and the company's management. The decision consists in the definition of weekly operating frequency (number of rides per week) of buses on international routes between Polish and Western European cities. The VAP is solved in a step‐wise procedure. In the first step a sample of efficient (Pareto‐optimal) solutions is generated using an original metaheuristic method called Pareto Memetic Algorithm (PMA). In the second step this sample is reviewed and evaluated by the Decision Maker (DM). In this phase an interactive, multiple criteria analysis method with graphical facilities, called Light Beam Search (LBS), is applied. The method helps the DM to define his/her preferences, direct the search process and select the most satisfactory solution.     

唐山至曹妃甸高速公路工程地质问题及处理技术

唐曹高速公路是河北省滨海地区修建的一条高等级公路,地质条件比较复杂,工程在前期适当加大了投入,从根本上降低了社会成本和环境成本,也减少了公路的后期养护费用,值得同行借鉴.     

三阶非线性方程三点边值问题的奇摄动

讨论了三阶非线性微分方程三点边值问题的奇摄动．利用积分算子和微分不等式技巧,得到了解的存在性、唯一性与渐近估计．结果表明,这种技巧为其它三阶边值问题的研究提出了一种新的思路．     

Solving resource-constrained multiple project scheduling problem using timed colored Petri nets

To solve the resource-constrained multiple project scheduling problem (RCMPSP) more effectively, a method based on timed colored Petri net (TCPN) was proposed. In this methodology, firstly a novel mapping mechanism between traditional network diagram such as CPM (critical path method)/PERT (program evaluation and review technique) and TCPN was presented. Then a primary TCPN (PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism. Meanwhile, the object PTCPN was used to simulate the multiple projects scheduling and to find the approximately optimal value of RCMPSP. Finally, the performance of the proposed approach for solving RCMPSP was validated by executing a mould manufacturing example.     

时间多项式进化算法在旅行商问题中的研究

提出了一种模拟生物遗传的进化算法，并将该算法应用于旅行商问题得到了较好的结果，根据达尔文进化论的优化过程，结合自然选择原则提出了启发式算法，该算法的时间复杂性与快速排序策略相当。在文中利用该算法求解中国旅行商问题得到目前的最佳结果。     

我国企业年金税收政策之我见

阐述了我国企业年金税收政策。分析了目前企业年金税收政策存在问题。指出了现行政策对我国年金发展存在的影响,以期促进我国企业年金的发展。