多车场有时间窗的多车型车辆调度及其禁忌算法研究

本文针对物流配送中的多车场车辆调度问题提出了两种多车场的处理方法，介绍了多车场车辆调度问题中容量、时间窗、多车型等多种约束的处理方法，并且根据具体约束情况设计了禁忌算法，对多车场有时间窗的多车型车辆调度问题加以实现，给出了一个具有代表性的算例试验结果和结果分析，通过试验表明了此方法对优化有时间窗的多车型车辆调度问题的有效性．     

A new volume of fluid method in three dimensions—Part II: Piecewise‐planar interface reconstruction with cubic‐Bézier fit

A new interface reconstruction method in 3D is presented. The method involves a conservative level‐contour reconstruction coupled to a cubic‐Bézier interpolation. The use of the proposed piecewise linear interface calculation (PLIC) reconstruction scheme coupled to a multidimensional time integration provides solutions of second‐order spatial and temporal accuracy. The accuracy and efficiency of the proposed reconstruction algorithm are demonstrated through several tests, whose results are compared with those obtained with other recently proposed methods. An overall improvement in accuracy with respect to other recent methods has been achieved, along with a substantial reduction in the central processing unit time required. Copyright © 2008 John Wiley & Sons, Ltd.     

车辆路径问题的改进遗传算法

提出一种基于遗传算法的求解车辆路径问题的新算法,避免传统遗传算法处理不可行约束条件中惩罚项系数选取不当所出现的问题.同时,通过现实例子分析该算法的优劣性,实验结果表明该算法是一种有效的算法.     

Diffusion of glycosylphosphatidylinositol (GPI)-anchored bovine prion protein (PrP) in supported lipid membranes studied by single-molecule and complementary ensemble methods

In this work cellular bovine prion protein (PrP^c) was incorporated in supported lipid membranes and its lateral diffusion was studied by single-dye tracking (SDT) and a complementary ensemble method, fluorescence recovery after photobleaching (FRAP). PrP^c was purified from calf brain with its native glycosylphosphatidylinositol (GPI) anchor and reconstituted into DMPC lipid vesicles. Homogeneous spreading on solid supports over macroscopic areas was confirmed with fluorescence microscopy. FRAP results demonstrated very high mobile fractions of up to 94%, confirming that most of the GPI-anchored PrP^c are freely diffusive in the fluid supported membrane matrix. Moreover, the lateral diffusivity of PrP^c significantly depends on the pH of the buffer, suggesting that the conformation of PrP^c and thus the frictional drag exerted to the protein molecule (and thus the effective hydrodynamic radius) is influenced by the effective net charge. To complement the ensemble results obtained by FRAP, the statistical variation of lateral diffusion coefficients of individual PrP^c molecules in the supported membranes were measured with SDT. Simulation-based statistical analysis indicated that in addition to the expected statistical scatter there is a significant spread of diffusion coefficients, while the average of the diffusion coefficients of individual proteins obtained by SDT is in excellent agreement with those measured by ensemble FRAP. In further experiments, PrP^c was laterally concentrated in the membrane by the application of tangential electric fields (membrane electrophoresis). However, the equilibrium concentration profile reached after 20 min was different from an exponential gradient. This finding suggests that PrP^c purified from bovine brain possesses non-uniform net charges. As the lateral diffusion coefficient of proteins in two-dimensional lipid membranes sensitively depends upon the frictional drag, the combination of SDT, ensemble FRAP, and membrane electrophoresis can be used as a powerful tool to gain insights into protein–protein binding and oligomer formation that would play a crucial role in infectious protein transmitted diseases such as BSE.     

Temperature-programmed synthesis of micron-sized multi-responsive microgels

A new synthetic protocol for the synthesis of large diameter (2.5 to 5 μm), temperature-, and pH-responsive microgels via aqueous surfactant-free radical precipitation copolymerization is presented. We have found that in this size range, which is not typically attainable using traditional dispersion polymerization approaches, excellent monodispersity and size control are achieved when the synthesis employs a programmed temperature ramp from 45 to 65 °C during the nucleation stage of the polymerization. A combined kinetic and thermodynamic hypothesis for large particle formation under these conditions is described. Particle sizes, volume phase transition temperatures, and pH responsivity were characterized by particle tracking and photon correlation spectroscopy to illustrate their similar behavior to particles made via more traditional routes. These particles have been enabling for various studies in our group where microscopic visualization of the particles is required.     

跟踪测量电视光学系统

电视系统是跟踪和测量飞行目标的主要手段之一。根据使用要求确定了电视跟踪系统中的光学系统主要参数，提出了一个新颖的光学系统方案以实现三个焦距对目标的跟踪和测量，并且对光学系统中各组元焦距的选择进行了讨论，最后给出了设计结果。     

Steady-State Analysis of Target Tracker with Constant Input/Bias Constraint

Navigation and surveillance applications require tracking constant input/bias targets. When the target＇s trajectory follows a constant input/bias constraint, model mismatching caused by conventional tracking algorithms can be handled by a delayed update filter （DUF）. The statistical convergence and stability properties of the delayed update filter were studied to insure the rationality of its steady-state analysis. A steady-state filter gain was then designed for a constant-gain DUF to reduce the computations without much performance loss. Simulations demonstrate the potential of the constant-gain DUF, and the CGDUF is nearly 60% faster than the DUF without much loss in steady-state tracking accuracy.     

最低价中标项目造价监管机制的探讨

通过某国有资金投资工程项目造价实例的测算,指出工程中标后至竣工结算阶段造价管理中存在两大问题：一是结算价超中标价,超过幅度较大;二是结算价少于实际支出,施工企业出现亏损。分析了产生这些问题的原因,尝试性地提出了工程造价跟踪监管体系。     

IMM迭代无迹Kalman粒子滤波目标跟踪算法

针对传统交互式多模型(interactive multiple model,IMM)算法跟踪机动式再入目标精度差和实时性不高的问题,提出一种交互式多模型迭代无迹Kalman粒子滤波算法.该算法在多模型滤波过程中采用改进的粒子滤波算法,通过迭代无迹Kalman滤波融入最新观测信息,进而生成粒子滤波的重要性密度分布,从而提高采样质量,改善滤波算法性能.仿真结果表明,提出的算法相对于交互式多模型粒子滤波算法具有更好的跟踪效果.该算法对提高跟踪机动式再入目标的精度与实时能力具有一定的理论意义.