基于关节力矩的柔性关节机器人的控制策略

由于关节柔性降低了系统的带宽并影响系统的鲁棒稳定性,因此,采用基于关节力矩负反馈的控制策略。通过减小电机端有效惯量的方法可以大大提高系统带宽并增强鲁棒稳定性;在机器人的控制上,采用一种基于全状态反馈的复合控制结构,证明了系统的稳定性,并在现有的机械臂上实现了位置和阻抗控制实验,验证了该控制策略的有效性和可行性。     

一种求解Shubert函数优化问题的演化算法

综合国内外演化计算研究现状,基于热力学中的自由能极小化原理, 设计了一个全新的热力学演化算法,并通过对于Shubert函数优化问题求解的数值试验,测试了热力学演化算法的优良性能,实验结果表明了热力学演化算法求出的解比一般演化算法求出的解更加接近于全局最优。     

A hybrid clustering and graph based algorithm for tagSNP selection

TagSNP selection, which aims to select a small subset of informative single nucleotide polymorphisms (SNPs) to represent the whole large SNP set, has played an important role in current genomic research. Not only can this cut down the cost of genotyping by filtering a large number of redundant SNPs, but also it can accelerate the study of genome-wide disease association. In this paper, we propose a new hybrid method called CMDStagger that combines the ideas of the clustering and the graph algorithm, to find the minimum set of tagSNPs. The proposed algorithm uses the information of the linkage disequilibrium association and the haplotype diversity to reduce the information loss in tagSNP selection, and has no limit of block partition. The approach is tested on eight benchmark datasets from Hapmap and chromosome 5q31. Experimental results show that the algorithm in this paper can reduce the selection time and obtain less tagSNPs with high prediction accuracy. It indicates that this method has better performance than previous ones.     

公选课教学改革的研究和实践

公共选修课设置的目的是为了拓宽学生的知识面,培养学生的多种技能,从而提高学生的综合素质,以期适应社会发展的要求。本文就公共选修课在教学上存在的问题,以"网络实用技术"公共选修课为例,提出具体的改革措施,实践证明,该措施有效地提高公共选修课教学质量。     

面向Si/SiC混合器件逆变器全寿命周期安全工作区的多开关模式主动切换策略

基于硅基绝缘栅双极型晶体管(Si IGBT)和碳化硅金属氧化物半导体场效应管(SiC MOSFET)的Si IGBT/SiC MOSFET混合器件采用多开关模式切换策略可使变换器具备应对复杂工况的能力,然而现有切换策略并未考虑器件疲劳老化对模式切换阈值电流的影响,在混合器件老化进程后期极有可能造成器件热失效,进而严重威胁变换器的可靠运行。基于此,提出了一种面向Si/SiC混合器件逆变器全寿命周期安全工作区的多开关模式主动切换策略。基于器件疲劳老化对逆变器最大安全运行电流的影响规律,设计了考虑老化进程的逆变器安全工作区刻画流程。根据安全工作区刻画结果,提出了适用于混合器件全寿命周期的多开关模式主动切换策略。实验结果表明,该策略能够针对混合器件不同老化程度来动态调整开关模式切换阈值电流,从而在器件全寿命周期内保障逆变器的运行可靠性。     

Boosting the confidence of new product development teams: The role of team boundary spanning,team size and functional diversity

In today's highly interconnected, uncertain and dynamic business environment, team boundary spanning has become an important determinant of the performance of new product development (NPD) projects. Despite the positive evidence supporting the use of boundary spanning activities by NPD teams, little is still known about how boundary spanning teams become high-performance teams. The current study advances research on this subject by examining the mediating effect of team potency on the relationship between team boundary spanning and new product performance, as well as the moderating effects of team size and functional diversity on the relationship between team boundary spanning and team potency. Data from a time-lagged survey study of 140 NPD projects found that team boundary spanning can promote team potency that, in turn, results in greater new product quality and new product creativity. The positive effect of team boundary spanning on team potency was found to be more pronounced for NPD teams of medium size and high levels of functional diversity.     

选择并融合粗细粒度特征的细粒度图像识别

目的 在细粒度图像识别任务中,类内图像姿势方差大,需要找到类内变化小的共性,决定该任务依赖于鉴别性局部的细粒度特征;类间图像局部差异小,需要找到类间更全面的不同,决定该任务还需要多样性局部的粗粒度特征。现有方法主要关注粗细粒度下的局部定位,没有考虑如何选择粗细粒度的特征及如何融合不同粒度的特征。为此,提出一种选择并融合粗细粒度特征的细粒度图像识别方法。方法 设计一个细粒度特征选择模块,通过空间选择和通道选择来突出局部的细粒度鉴别性特征;构建一个粗粒度特征选择模块,基于细粒度模块选择后的局部,挖掘各局部间的语义和位置关系,从而获得为细粒度局部提供补充信息的粗粒度多样性特征;融合这两个模块中提取到的细粒度特征和粗粒度特征,形成互补的粗细粒度表示,以提高细粒度图像识别方法的准确性。结果 在CUB-200-2011（caltech-UCSD birds-200-2011）、Stanford Cars和FGVC-Aircraft（fine-grained visual classification aircraft） 3个公开的标准数据集上进行广泛实验,结果表明,所提方法的识别准确率分别达到90.3%、95.6%和94.8%,明显优于目前主流的细粒度图像识别方法,相较于对比方法中的最好结果,准确率相对提升0.7%、0.5%和1.4%。结论 提出的方法能够提取粗粒度和细粒度两种类型的视觉特征,同时保证特征的鉴别性和多样性,使细粒度图像识别的结果更加精准。     

基于3D路径聚合高分辨率网络的胰腺分割

目的 胰腺的准确分割是胰腺癌识别和分析的重要前提。现有基于深度学习的主流胰腺分割网络大多是编码—解码结构,对特征图采用先降低再增加分辨率的方式,严重丢失了胰腺位置和细节信息,导致分割效果不佳。针对上述问题,提出了基于3D路径聚合高分辨率网络的胰腺分割方法。方法 首先,为了捕获更多3D特征上下文信息,将高分辨率网络中的2D运算拓展为3D运算;其次,提出全分辨特征路径聚合模块,利用连续非线性变换缩小全分辨率输入图像与分割头网络输出特征语义差异的同时,减少茎网络下采样丢失的位置和细节信息对分割结果的影响;最后,提出多尺度特征路径聚合模块,利用渐进自适应特征压缩融合方式,避免低分辨率特征通道过度压缩导致的信息内容损失。结果 在公开胰腺数据集上,提出方法在Dice系数（Dice similarity coefficient,DSC）、Jaccard系数（Jaccard index,JI）、精确率（precision）和召回率（recall）上相比3D高分辨率网络（3D high-resolution net,3DHRNet）分别提升了1.41%、2.09%、2.35%和0.49%,相比具有代表性编码—解码结构的胰腺分割方法,取得了更高的分割精度。结论 本文提出的3D路径聚合高分辨率网络（3D pathaggregation high-resolution network,3DPAHRNet）具有更强的特征位置和细节信息的保留能力,能够显著改善在腹部CT（computed tomography）图像中所占比例较小的胰腺器官的分割结果。开源代码可在https：//github.com/qiuchengjian/PAHRNet3D获得。     

航空机载软件全数字仿真测试系统的设计与实现

针对航空机载软件测试环境与开发环境冲突、测试环境可控性和通用性差、非干预性测试困难的问题,分析了全物理实装测试环境、半实物仿真测试环境的优缺点,研究了全数字仿真测试技术,设计并实现了一种航空机载软件全数字仿真测试系统。该系统由仿真核心平台、仿真工具组件、协同仿真组件和人机交互组件构成,提供了航空机载处理器、内存、外设等多种可重用库。提出了基于底层虚拟机的动态二进制翻译技术、协同仿真时间同步和数据通信机制等关键技术,实现了航空机载软件全数字高速闭环仿真运行。工程实践证明,该系统能达到降低硬件设备的依耐性、简化测试环境搭建的复杂度、提高测试效率约42%的目的。     

Firm diversity and data breach risk: A longitudinal study

Research has extensively investigated the rationale of firm diversity from the economic perspective, but little is known about how such a strategy may affect information security. The present study is the first to examine how firm diversity is relevant to firms’ likelihood to experience data breaches (i.e., data breach risk). Drawing from the strands of literature on information security, diversification, and resource-based view, we propose hypotheses on the relationship between firm diversity and data breach risk, as well as the boundary conditions of this relationship. On the basis of a twelve-year sample of publicly-listed firms, our analysis provides evidence to support the negative association between firm diversity and data breach risk. Our analysis also delineates conditions under which the effects of firm diversity can intervene to reduce the data breach risk invoked, such as under related diversity and when managers are managerially capable. For academics, our research accentuates an intriguing but unexamined benefit of firm diversity because it relates to information security. For practicing professionals, this research highlights the significant impact of firms’ operational structure on information security.