Development and validation of a biodynamic model for predicting multi-finger movements in cylinder-grasping tasks †

This article describes the development and validation of a model for predicting multi-finger movements in grasping activities. The model builds upon a newly proposed approach that incorporates forward dynamics and a system identification procedure, and is amenable to empirical tests. A database of multi-fingered grasping movements performed by 28 subjects was established and divided into four sets, one for model development and three for model validation. In the development phase, model parameter values were estimated by the iterative system identification procedure through a physics-based heuristic algorithm. The estimated parameter values were then statistically synthesised and integrated into the prediction model. In the validation phase, the model was applied to three novel datasets containing different grasping movements involving objects of varied sizes and different subjects. The results demonstrated the model's ability to predict hand prehensile movements with error magnitudes comparable to the inter-person variability in performing such movements. New insights into the control of multi-fingered hand prehensile movements at the systems and joint levels emerged from the model development and validation process. The current study contributes to building a foundation for long-term development of realistic biodynamic simulation of multi-finger hand movements. Such simulation capabilities will aid in design of hand-operated tools, devices or hand-intensive work for proactive ergonomics and in evaluation as well as treatment of functional impairment of the hand.     

大学生志愿服务现状调查与动力机制构建——基于江西部分高校的调查

就大学生志愿服务问题对江西部分高校展开调查,依据调查结果,运用系统动力学方法对大学生志愿服务进行因果关系分析,最后构建出大学生志愿服务的动力机制:完善信息管理系统;健全组织管理体系;构建基础培训和专业培训融合的培训体系;拓展服务活动的深度与广度;制订基于学生需求导向为动机的激励制度;改进经费筹管和法律保护。     

ZigBee在动态血压监测中的应用研究

我国已成为世界上高血压危害最严重的国家之一,在全国范围大力开展高血压病的防治,积极治疗高血压病患者,已经刻不容缓.通过研究ZigBee技术,提出了以ZigBee无线传感器网络为核心,以以太网为骨干网,采用CC2430芯片为血压传感器控制核心的动态血压测量方案,系统测量的收缩压、舒张压误差范围均小于5mmHg.试验证明,系统能够实时监测患者的血压变化,工作稳定可靠,具有较高的实用性和市场价值.     

基于遗传算法的关联议题并发谈判

基于遗传算法的并发谈判在电子商务应用中具有独特的优势,但已有的研究尚未考虑议题之间的相关性、动态权重的变化规则依赖于对手信息的获取,极大地限制了其使用价值.对此,提出议题分组的方法以解决议题的相关性问题,而议题权重的变化则采取从历史资源中发掘知识的方法进行动态调整.构建了基于遗传算法的关联性议题并发谈判模型,给出了模型的形式化描述、谈判算法设计和动态权重更新方案.通过对模型的实验和比较分析,证实了该方案能够更方便地满足用户谈判的多样性需求,解决谈判中议题关联性的问题,而且能够快速、有效地得出最优谈判结果.     

动态可重构环境下循环计算的位宽优化

动态可重构技术允许根据计算的运行时情况对硬件处理单元进行重构，使其位宽适合计算的需要。而且，对代表计算密集型任务的循环计算进行位宽的动态优化可达到提高处理性能，减少所消耗的芯片资源和功耗的目的。本文构造了一个处理框架对循环计算的位宽进行动态的优化，包括对循环计算的位宽变化情况进行理论和运行时的分析，以及构造1个位宽管理算法选择重构的时机和对配置文件进行调度。通过对实验结果的分析，证明了我们的方案具有较好的性能。     

提高变压器抗短路强度的措施

变压器对抗短路强度的要求是很高的。文中介绍了变压器短路时的电动力的作用情况，结合单位实际情况介绍了提高变压器抗短路能力的措施。     

Observation and computer simulation of multicomponent chemical short-range order （MCSRO） for the bulk metallic glasses

The atomic configuration of chemical short-range order (CSRO) for the Zr-base metallic glasses was investigated by using nano-diffraction and high resolution transmission electronic microscopy (HRTEM) technology with a beam size of 0.5 rim. It is illustrated that the pattern of atomic configuration of CSRO might have various compound counterparts because of the chemical interaction of bonding atoms. Some atomic configuration of MCSRO is similar to the icosahedral structure with 10-fold symmetry of very weak spots. In deed, the nano-beam technology could clearly detect the evolution of atomic configuration in nanometer scale during the transformation from the metallic melt to the primary crystallization. The local atomic configuration of CSRO is also investigated by molecular dynamics simulation (MD) for the Zr2Ni compound in a wider temperature range. The CSRO in the melt could be pictorially demonstrated as distorted coordination polyhedron of the compound structure and/or the structure similar to cubo-octahedron analogs. The MD simulation illustrates that the atomic packing of long-range order disappears just above the melting point, but the chemical interaction of bonding atoms still exists that leads to form the various CSRO with the atomic configuration similar to stable or metastable unit cell of Zr2Ni compound. The icosahedral polyhedron became more abundance as the overheating temperature was raised.     

Java虚拟机中类装载机制的原理分析与应用研究

Java类的动态装载机制是Java虚拟机的一项核心技术,可以在运行时刻动态地加载或替换系统的某些功能模块,而不影响系统其它功能模块的正常运行。本文介绍了Java虚拟机中类的动态装载机制的原理、实现及应用,分析了类装载器的结构、用途,阐述了利用自定义类装载器装载并执行Java类的过程。     

微振动对空间实验室微重力环境的影响研究

针对大型刚柔组合体空间结构(空间实验室)的特点,建立系统的动力学方程,并对机柜内设备、太阳阵的转动、宇航员活动产生的激扰力进行了简化。利用计算机建立组合体的简化模型,对空间组合体在各种微振动激扰下的加速度响应进行了仿真研究,并将这些仿真结果用于空间实验室微重力环境的预测。     

生成黑盒测试数据的设计思想在学生成绩管理系统中的实现

黑金测试是数据库应用系统测试的常用方法，而生成大量测试数据则是进行黑金测试的前提。如果能使用“数据生成”工具生成大量模拟测试数据，将提高数据库应用系统的测试效率和测试质量。本文主要提出了生成黑金测试数据的设计思想，并基于这一思想开发了“学生成绩管理系统”的数据生成工具。