新装卸工艺下双倍场吊的平板小车调度策略

为给高效智能型立体装卸集装箱码头生产调度系统提供1套双倍场吊的平板小车调度策略,以最小化平板小车运行时间为目标,构建动态规划模型,并采用简化算法减少求解模型的时间,使得模型及其求解能够满足实时作业的需要.新工艺下双倍场吊的平板小车调度系统通过减少岸吊和双倍场吊之间的运行距离和等待时间来提高集装箱码头的装卸效率.通过案例分析,新装卸工艺比传统装卸工艺的工作效率提高约7%.     

A comparative analysis of cognitive profiles: Monozygotic and dizygotic reading-disabled twins

Previous twin studies have provided evidence for genetic influences on reading disability (RD) or normal reading ability. The existence of subtypes of RD — each with its characteristic cognitive profile — has been suggested. Whether the etiology of the particular subtypes is genetic is uncertain. The present study examined within-pair comparisons of cognitive profiles (with respect to composites of general reading, symbol processing speed and sequential memory) in RD and control twins. Twin profile analysis were applied to these cognitive composites on 120 pairs of RD and control twins. Results showed a greater monozygotic (MZ) than dizygotic (DZ) resemblance in profiles indicating that individual differences in the patterning of cognitive abilities related to reading are genetically influenced.     

关于狭义二元筛法

建立了新的筛法－狭义二元筛法及与此相关的两个筛函数，并给出了狭义二元筛函数所对应的同余方程组。     

New IT技术驱动下数字孪生图书馆虚实空间融合机理

在New IT新一代技术引导下,用户智能化、数字化的资源服务需求,虚拟现实与泛在感知传感器的融合,将改变传统图书馆的空间形态,推动数字孪生图书馆的诞生。论文通过对孪生图书馆虚实空间样貌、核心要素探讨,依据系统论、全生命周期理念,构建数字孪生图书馆虚实空间多维融合模型和场景融合模型图,并提出孪生图书馆虚实空间模型、数据、服务之间交互融合机制,进而分析虚实空间场景融合的四种模式:空间场景融合、学习场景融合、服务场景融合、文化场景融合。     

关于素数的孪生素数的注记

利用Sundcaram筛法，给出素数的表示，在此基础上得到了关于素和的判别定理和相应筛法。     

双桨双舵船横驶靠泊方案

为提高靠泊安全性、降低靠泊成本、减少靠泊过程中对外力的依赖,基于MMG建模方法建立不同风、流情况下的配备双桨双舵和艏侧推器的船舶自主靠泊数学模型,得出横驶靠泊的左右桨及侧推器的动力配比.在此基础上对某实验船在不同风、流环境条件下的横驶靠泊方案进行研究,并给出具体的靠泊参考方案.     

基于双40英尺集装箱装卸系统的自动化码头堆场计划

为解决双40英尺集装箱装卸系统的自动化码头堆场分配问题,运用多目标规划方法,建立滚动式的集装箱码头出口箱堆场计划模型.此模型在缩短出口箱箱位到相应泊位的总运输距离、平衡各场桥的工作量以及提高双40英尺集装箱装卸率的基础上建立目标函数,以达到提高码头装卸效率和降低码头装卸成本的目的.为了得到模型的可行解并对其进行优化,设计启发式算法和离散粒子群算法流程.最后,通过案例分析验证该堆场计划模型的有效性和实用性.     

平行双孔隧道开挖变形三维数值分析

基于Gibson土建立平行双孔隧道的三维实体结构计算模型,考虑衬砌与周围土体的共同作用,并在盾构开挖面处施加表面力以模拟切削刀盘的推进力效应,分析平行双孔隧道同步开挖及不同滞后距离异步开挖时隧道相互作用所引起的周边土体变形及收敛形式。研究表明,平行双孔隧道异步开挖时,滞后距离对超前开挖隧道周围的竖直沉降影响微小,而对后挖隧道断面竖直沉降以及左右隧道水平位移的影响较大;随两隧道间距的增加,开挖时相互的影响会随之减小。     

同向双螺杆端面内混合模拟

建立了同向自洁双螺杆端面内二维周期性流动的物理模型及数学模型。借助商用有限元软件POLYFLOW叠加网格技术求解得到速度场,基于具有4阶精度的RungeKutta数值积分方法自行开发了流体前锋追踪代码,并对对混合过程动力学进行了数值模拟表征。采用粒子群可视化模拟、Poincaré截面分析、界面演化及界面增长等探讨了混合过程动力学细节,揭示混沌混合作用的尺度。结果表明,传统的同向双螺杆端面内混沌混合与常规的层流混合共存,不同区域的混合效果相差很大。螺槽中部存在8字型准周期运动带,带内混合为常规的层流混合。     

The relationship between homework and the academic progress of children in Spain during compulsory elementary education: A twin fixed-effects approach

Homework has traditionally been considered positive for students’ academic achievement, to the extent that it makes children more responsible while learning. Nevertheless, making students do a large amount of homework has been one of the most criticised practices in recent years. Parental associations have long held the view that Spanish elementary school pupils spend too much time on homework. This situation is so alarming that it has recently caused a ‘homework strike’, which has been supported by many children's parents. Furthermore, being assigned an excessive amount of homework is a serious problem which extends well beyond Spain. In light of this context, this article aims to provide new evidence on the relationship between homework and academic performance. To carry out this research, rich longitudinal census data, together with a twin fixed-effects approach and value-added models, have been used. In this way, we can control for variables that are the same within twins, allowing us to generate a better understanding of the association between homework time and primary children's academic achievement. Our main finding is that homework is not associated with young people's academic achievement (at least within this specific country context).