A quantitative optimisation model for a horizontal MEMS solid propellant thruster with experimental verification

This paper studies the effect of multiple geometric parameters of a micronozzle on a MEMS solid propellant thruster (MSPT) and establishes a quantitative optimisation model. Influences of the structural parameters of the micronozzle on performance are accurately calculated. The significance and contribution ratio of each parameter are evaluated by F distribution. Correspondingly, a horizontal MSPT is fabricated and tested to prove the optimisation model. In the implementation, a complete microigniter is formed by a single layer of Au, achieving an ultra-low ignition voltage of 2.1 V with an extremely low ignition resistance of 4 Ω.     

Influence of disk curvature on slider attitude under operational shock conditions for a 2.5-in. hard disk drive

Recently, the number of disks in hard disk drives has increased, and the gap between the slider and disk has decreased. These changes make the contact between the ramp and disk easily. External shock and ramp–disk contact can cause change in disk curvature. Such a change in disk curvature affects the air bearing pressure between the slider and disk. However, disk curvature has not been considered in the previous research. Thus, in this study, we investigated the influence of disk curvature on slider dynamics. Disk curvature was calculated from a transient shock analysis, and was then applied to slider dynamic analysis. As a result, disk curvature reduced the shock performance, by decreasing the minimum flying height and increasing the pitch and roll angle of the slider.     

利用内置导轨的清洁机器人垂直运动控制

针对建筑物表面清洁机器人(BFMR)容易受环境和振动影响、运行稳定性差等问题,设计了安全稳定的控制系统.在垂直和水平机器人的对接过程中,利用导轨制动系统抑制冲击,并利用再平层过程补偿机器人内置导轨与建筑物表面导轨之间的定位误差.此外,利用提出的振动抑制系统,根据钢丝绳动态属性的状态估计值,控制钢丝绳的加速度,对环境噪声产生的振动进行抑制,提高垂直机器人垂直运动的稳定性和可靠性.实验结果表明,本文设计的控制系统能够有效降低振动影响,具有可行性.     

IPI:一种基于影响力和兴趣的链接预测算法

链接预测的一个关键问题在于如何合理高效地结合链接属性、节点属性等相关信息以用于预测的目的,针对该问题提出了一种基于节点影响力和兴趣的链接预测算法IPI(Influence Plus Interest),即通过拓扑结构信息来量化用户的影响力,通过文本信息来模拟用户兴趣.结合两类信息对节点间的联系进行打分,得分高的节点对即代表具有较强的联系.在真实数据集上的实验表明,我们提出的方法具有一定的可行性.     

A service recovery method to enhance customer satisfaction with a case study of motion sport game

Service recovery is a concept that involves regaining customer satisfaction and loyalty. Although existing studies have addressed its importance, few service recovery methodologies have been developed. Thus, there is a need to develop a systematic framework that can first detect customer status and then provide appropriate recovery recommendations to ensure customer satisfaction. This study develops such a framework in relation to an individual health maintenance practice. While regular moderate exercise is known to promote good health and help prevent disease, the lack of exercise remains a crucial health issue. This study presents a logistic regression model that uses both physiological data (heart rate and blood pressure) and psychological data (ratings of perceived exertion) to detect the effectiveness of an individual's exercise and to provide sports‐related service recovery suggestions as needed. To implement and assess this service recovery model, the use of a motion gaming system is proposed.     

Safe binary particle swam algorithm for an enhanced unsupervised label refinement in automatic face annotation

Mining web facial images on the internet has become as a profitable and important paradigm towards auto face annotation technique. The unsupervised label refinement (ULR) is an effective method that can fix weakly labeled facial images data which are collected from the internet and included some images with wrong label. In order to improve the correction accuracy of ULR, particle swarm optimization (PSO) and binary particle swarm optimization (BPSO) are used for solving binary constraint optimization task in this study. A novel method named safe binary particle swam optimization (SBPSO) is also proposed to improve BPSO which has the probability over range problem for using the ULR. In addition, SBPSO is also employed for an enhanced ULR (EULR) objective function which is created by modifying the original formula of ULR to improve the accuracy of labeled facial image. An experimental database is queried from IMDb website which collected the actors who were bored in 1950 to 1990. Some error flags are randomly added in the database for the correction tests by different methods. The results showed that the SBPSO Algorithm for the EULR in automatic face annotation have the better label correction rate and convergence effect.     

Intelligent robotic gripper with adaptive grasping force

The on-off control robot gripper is widely employed in pick-and-place operations in Cartesian space for handling hard objects between two positions. Without contact force monitoring, it can not be applied in fragile or soft objects handling. Although, an appropriate grasping force or gripper opening for each target could be searched by trial-and-error process, it needs expensive force/torque sensor or an accurate gripper position controller. It has too expensive and complex control strategy disadvantages for most of industrial applications. In addition, it can not overcome the target slip problem due to mass uncertainty and dynamic factor. Here, an intelligent gripper is designed with embedded distributed control structure for overcoming the uncertainty of object’s mass and soft/hard features. A communication signal is specified to integrate both robot arm and gripper control kernels for executing the robotic position control and gripper force control functions in sequence. An efficient model-free intelligent fuzzy sliding mode control strategy is employed to design the position and force controllers of gripper, respectively. Experimental results of pick-and-place soft and hard objects with grasping force auto-tuning and anti-slip control strategy are shown by pictures to verify the dynamic performance of this distributed control system. The position and force tracking errors are less than 1 mm and 0.1 N, respectively.

     

飞行器性能样机虚拟试验系统研究与实现

为实现航天飞行器研制中性能样机模型的充分利用,提出了飞行器性能样机虚拟试验系统的总体方案,通过试验基础数据库、试验数据管理、验证辅助工具、虚拟试验应用等子系统划分和工作流程设计,提供对虚拟试验的全流程支持。系统突破了试验数据对象化管理、试验流程建模等关键技术,并基于虚拟试验支撑平台VITA完成了相应系统实现,在多个飞行器研制过程中开展了典型应用。     

基于Isolation Forest的并行化异常探测设计

异常探测具有广泛的应用,受到了工业界和学术界的共同关注。在众多异常探测方法中,Isolation Forest算法具有执行效率高、探测准确度好的特点,获得了众多应用。但是,传统Isolation Forest算法难以处理大规模数据。为解决此问题,设计了一种基于云计算平台的算法。具体地,使用Hadoop分布式存储系统和MapReduce分布式计算框架设计并实现了基于Isolation Forest的并行化异常探测算法PIFH。通过将探测模型构建和数据异常评价的过程并行化,提升了PIFH算法探测异常的执行效率,扩展了其应用范围。利用真实世界数据集验证了所提算法的执行效率和可扩展性。