设计余弦调制QMF组的一种新方法

通过适当矩阵变换，本文首先将精确重建余弦调制正交镜像滤波器组的设计转化为一种带约束的非线性优化问题，它是一种带二次型约束的最小二乘（ＱＣＬＳ）优化问题，然后，我们提出了一种变参量的罚函数方法来有效求解该类ＱＣＬＳ优化问题，通过直接采用原型滤波器系数为优化变量，我们构造了一个特殊的凸函数作优化代价函数，故可获得该问题的全局最小点，最后，采用本文提出的设计方法进行了一个具体实例设计，结果表明我们的方法     

竞争型脉冲耦合神经网络及用于多约束QoS路由求解

在脉冲耦合神经网络的基础上提出了竞争型脉冲耦合神经网络模型,分析了该模型用于求解网络最短路由时的脉冲波传播特性,并提出了脉冲波任务的产生、分解和状态转换理论,在模型中实现了脉冲波的多约束传播,成功地应用于网络多约束QoS路由问题的求解,并可得到全局最优解.仿真实验表明,与其他算法相比,该方法的计算迭代次数最少,且减少较多;而且迭代次数只与网络路由图中源点与目的点之间的最优QoS路由长度有关,而与节点数、链路数和网络的分布构成复杂性无关,体现出较好的计算性能和优势.     

西汉水流域规划中的GPS数据处理

介绍了西汉水流域规划测量中的GPS数据处理过程,包括基线解算与自由网平差、高斯面的约束平差、工程面上的平差和GPS高程拟合.     

A new scheduling technique for the resource–constrained project scheduling problem with discounted cash flows

In this paper, we discuss the resource–constrained project scheduling problem with discounted cash flows. We introduce a new schedule construction technique which moves sets of activities to improve the project net present value and consists of two steps. In particular, the inclusion of individual activities into sets, which are then moved together, is crucial in both steps. The first step groups the activities based on the predecessors and successors in the project network, and adds these activities to a set based on their finish time and cash flow. The second step on the contrary does so based on the neighbouring activities in the schedule, which may but need not include precedence related activities. The proposed scheduling method is implemented in a genetic algorithm metaheuristic and we employ a penalty function to improve the algorithm’s feasibility with respect to a tight deadline. All steps of the proposed solution methodology are tested in detail and an extensive computational experiment shows that our results are competitive with existing work.     

基于MATLAB的GPS网三维平差方法研究

研究了GPS控制网平差模型，探讨了采用MATLAB进行GPS网三维平差的可行性，并结合GPS控制网三维无约束平差实例的结果进行分析。实例证明，基于MATLAB进行GPS网平差具有精度高、编程简单、工作效率高、平差过程清晰等优点。为解决复杂的GPS网平差计算提供了新的便捷途径。     

Energy-saving generation dispatch toward a sustainable electric power industry in China

Energy shortages, climate change and environmental pollution are critical issues that the entire world is faced with currently. To tackle the challenge and realize sustainable development, the Chinese government launched the Energy-Saving Generation Dispatch (ESGD) in 2007. In the ESGD scheme, generating units are dispatched based on fuel consumption rates and pollutant emission intensities from low to high. However, annual generation quotas still widely exist. With the mandatory shutdown of small-capacity and low-efficiency thermal generating units in 2006–2010, most of the currently running thermal generating units are large-capacity and highly efficient units. The additional improvement of the overall energy efficiency under this situation is a key problem for the Chinese electric power industry. To this end, a new type of ESGD framework is designed in this paper. Sequential coordination among yearly, monthly, day-ahead and real-time generation schedules is proposed. Based on the framework, the corresponding models are formulated. Empirical analysis is conducted using the realistic data obtained from the Guangdong Power Grid Corporation. Four generation dispatch modes are compared. The results indicate that the proposed ESGD mode can further reduce energy consumption and pollutant emissions. Hopefully, this paper can provide a valuable reference for policy making in the Chinese power sector.     

A constrained‐optimization methodology for the detection phase in contact mechanics simulations

The detection phase in computational contact mechanics can be subdivided into a global search and a local detection. When potential contact is detected by the former, a rigorous local detection determines which surface elements come or may come in contact in the current increment. We first introduce a rigorous definition of the closest point for non‐differentiable lower‐dimensional manifolds. We then simplify the detection by formulating an optimization problem subject to inequality constraints. The formulation is then solved using different techniques from the field of mathematical optimization, for both linear and quadratic finite element meshes. The resulting general and robust detection scheme is tested on a set of problems and compared with other techniques commonly used in computational geometry. Copyright © 2013 John Wiley & Sons, Ltd.     

Estimating intravoxel fiber architecture using constrained compressed sensing combined with multitensor adaptive smoothing

In diffusion magnetic resonance imaging (dMRI), the accuracy of fiber tracking and analysis depends directly on that of intravoxel fiber architecture reconstruction. Several methods have been proposed that estimate intravoxel fiber architecture using low angular resolution acquisitions owing to their shorter acquisition time and relatively low b‐values. But these methods are highly sensitive to noise. We propose an approach to estimating intravoxel fiber architecture in low angular resolution dMRI. The method consists in using a constrained compressed sensing (CCS) method, also known as crossing fiber angular resolution of intravoxel architecture (CFARI) technique, in combination with multitensor adaptive smoothing in which a diffusion‐weighted (DW) image smoothing scheme is constructed according to the properties of the multitensor field estimated using CFARI. The results on synthetic, physical phantom and real brain DW images show that the proposed method is able to better resolve fiber architectures while correctly preserving image edge information, which provides a new tool for investigating the microstructures of biological tissues and for fiber tractography. © 2015 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 25, 285–296, 2015     

基于约束最小二乘的纯方位多站被动跟踪算法

纯方位单站目标被动跟踪需要观测站作机动才能满足可观测条件,导致跟踪算法收敛时间较长。基于纯方位多站被动跟踪算法可以解决算法收敛时间较长的问题,文中提出了一种约束最小二乘算法用于纯方位多站被动跟踪,它首先为最小二乘算法引入约束条件,利用矩阵最小特征值所对应的特征向量,解决了EKF 算法需要初值的问题,避免了滤波的发散,同时也极大地减小了最小二乘估计的偏置。仿真表明,这种算法能够渐进地逼近估计误差的下限,并且其精度有所增加,是一种渐进、稳定以及近似无偏的估计算法。     

A framework of critical resource chain for project schedule analysis

Analysing a schedule is beneficial to help stakeholders understand the scheduled project. Project schedules, which create time plans based on the critical path method (CPM) or on resource‐constrained project scheduling problem (RCPSP) optimization, are targets herein. The Theory of Constraints (TOC) treats a schedule as a system. Schedule elements are suspected constraints and a goal depends on the schedule creation policy. Resource information is further surveyed herein to identify true constraints. A framework is proposed to integrate identified constraints on a schedule, and the critical resource chain concept is introduced. Three scenarios illustrate the proposed framework under different scheduling considerations. Results explain schedule constraints, and several schedule analysis issues are discussed.