岷江航电犍为枢纽工程库区防护分析及方案选择

岷江航电犍为枢纽工程库区经济条件好,沿河人口稠密,工农业生产发达,水库淹没损失大,为减少淹没损失和减轻移民安置压力,进行防护研究十分必要.文章主要对各淹没敏感点的淹没影响进行分析,论证各敏感点的防护条件,通过技术经济比较,按经济合理的原则提出防护或补偿方案.     

An efficient implementation of the Min-Min heuristic

Min—Min is a popular heuristic for scheduling tasks to heterogeneous computational resources, which has been applied either directly or as part of more sophisticated heuristics. However, for large scenarios such as grid computing platforms, the time complexity of a straightforward implementation of Min—Min, which is quadratic in the number of tasks, may be prohibitive. This has motivated the development of high performance computing (HPC) implementations, and the use of simpler heuristics for the sake of acceptable execution times. We propose a simple algorithm that implements Min—Min requiring only O(mn) operations for scheduling n tasks on m machines. Our experiments show, in practice, that a straightforward sequential implementation of this algorithm significantly outperforms other state of the art implementations of Min—Min, even compared to HPC implementations. In addition, the proposed algorithm is at least as suitable for parallelization as a direct implementation of Min—Min.     

An upper （lower） bound for Max （Min） CSP

The random constraint satisfaction problem(CSP)instances generated by Model RB have been widely used in the field of CSP and have some nice features.In this paper,we consider two optimization versions of CSP,i.e.,the maximum constraint satisfaction problem(Max-CSP)and the minimum satisfaction problem(Min-CSP)of Model RB.The problem of the Max-CSP is how to find an assignment to all the variables such that the maximum number of constraints are satisfied and the problem of Min-CSP is how to find an assignment to all the variables such that the minimum number of constraints are satisfied.We use the first moment method to prove that when r2α(1/p-1)(or p2α/(2α+r)),an upper bound of Max-CSP can be derived.Similarly,we can prove that when r2α(1/p-1)(or p2α/(2α+r)),a lower bound of Min-CSP can be derived.     

基于总体方差最小消去DCT的方块效应

提出基于总体方差最小消去离散余弦变换DCT的方块效应,推导出水平集方程,用最小/最大曲率流替代水平集中的平均曲率流。该方法在平滑噪声和消去方块效应的同时,能保留图像的主要结构特征。后续分割实验结果表明,该方法比均值滤波后的图像有更好的视觉和分割效果。     

Min(N,D)-策略下M/G/1排队系统的离去过程

考虑Min(N,D)-策略下M/G/1排队系统的离去过程.运用全概率分解技术和更新过程理论,从任意初始状态出发,讨论系统在有限时间区间内离去顾客的平均数,得到了离去顾客平均数的瞬态表达式和稳态表达式,并给出了离去过程、服务员状态过程和服务员忙期中的服务更新过程之间的重要关系,该关系揭示了离去过程的随机分解特性:离去顾客的平均数被分解为两部分,一部分是服务员忙的概率,另一部分是服务员忙期中的离去顾客平均数,从而简化了对离去过程的研究.最后,得到了便于有效计算离去顾客平均数的渐近展开式,以及一些特殊情形下的相应结果.在排队网络中,由于一个排队系统的输出即为下游排队系统的输入,希望本文所得结果为排队网络的研究提供有用的信息.     

结构主动多重调谐质量阻尼器(AMTMD)的控制策略

本文提出了一种新控制策略———主动多重调谐质量阻尼器 (AMTMD)。AMTMD控制系统频率呈线性分布。AMTMD中的MTMD保持相同的刚度和阻尼系数但质量变化。基于TMD的工作原理对AMTMD定义了主动控制力构成即保持相同的位移和速度反馈增益系数但变化加速度反馈增益系数。基于结构的广义振型模型 ,导出了设置AMTMD时结构的动力放大系数 (DMF) ,于是AMTMD的优化准则可定义为结构最大动力放大系数最小值的最小化 (Min Min Max DMF)。通过最优搜寻 ,研究了反映AMTMD有效性和鲁棒性的参数。这些参数包括 :频率间隔、平均阻尼比、调谐频率比、总数、质量比和标准化加速度反馈增益系数。为了比较 ,同时考虑了多重调谐质量阻尼器 (MTMD)和主动调谐质量阻尼器 (ATMD)。     

基于多注意力机制的维吾尔语人称代词指代消解

针对深度神经网络模型学习照应语和候选先行语的语义信息忽略了每一个词在句中重要程度, 且无法关注词序列连续性关联和依赖关系等问题, 提出一种结合语境多注意力独立循环神经网络(Contextual multi-attention independently recurrent neural network, CMAIR) 的维吾尔语人称代词指代消解方法. 相比于仅依赖照应语和候选先行语语义信息的深度神经网络, 该方法可以分析上下文语境, 挖掘词序列依赖关系, 提高特征表达能力. 同时, 该方法结合多注意力机制, 关注待消解对多层面语义特征, 弥补了仅依赖内容层面特征的不足, 有效识别人称代词与实体指代关系. 该模型在维吾尔语人称代词指代消解任务中的准确率为90.79 %, 召回率为83.25 %, F值为86.86 %. 实验结果表明, CMAIR模型能显著提升维吾尔语指代消解性能.     

地下坑道综合管线优化方法研究与设计

综合管线优化是指在有限区域内将暖通,给水,排水,强弱电等专业管线合理布置,以满足建筑对取暖,通风,水电等的需求.这是一类复杂的布局问题,需要耗费工程设计人员大量的时间.为了提供一种高效的搜索策略,文中提出了拥挤度的概念,并结合经验知识和降维思想对其进行简化,将问题分解成截面布局、连线、调整三个基本的二维约束满足问题,分别采用最小约束法、智能回溯法和爬山法来求解.最后的仿真实验结果及分析表明,该方法能有效地提高搜索效率,从而缩短了综合管线的设计周期.     

Estimation fusion algorithms in the presence of partially known cross-correlation of local estimation errors

This paper addresses estimation fusion when the cross-correlation of local estimation errors is partially known. The statistical dependence of local estimation errors is first discussed, and then the concept of correlation coefficient is introduced to model the cross-correlation approximately. Two algorithms are proposed. One is based on min–max technique, which minimizes the maximal Mahalanobis distance between two fused estimates. The other one uses the prior distribution of the correlation coefficient and obtains a closed form of estimation fusion with the help of a series of matrix manipulations. Compared with some available algorithms in literature, simulation results demonstrate the effectiveness of the proposed approaches.     

An ACO algorithm for makespan minimization in parallel batch machines with non-identical job sizes and incompatible job families

We study the problem of scheduling a set of N jobs with non-identical job sizes from F different families on a set of M parallel batch machines; the objective is to minimize the makespan. The problem is known to be NP-hard. A meta-heuristic based on Max–Min Ant System (MMAS) is presented. The performance of the algorithm is compared with several previously studied algorithms by computational experiments. According to our results, the average distance between the solutions found by our proposed algorithm and the lower bounds is about 4% less than that of the best of all the compared algorithms, demonstrating that our algorithm outperforms the previously studied algorithms.