毫米级潜艇形机器人在低雷诺数液体中的3D运动及微操作方法研究

为模拟机器人在人体环境中的3D运动及微操作,提出了毫米级潜艇形机器人在低雷诺数液体中保持水平姿态实现3D运动及执行微操作的方法.首先,设计并加工了潜艇形机器人以及4线圈磁驱动系统,通过COMSOL软件对磁场系统进行了有限元仿真.然后,对机器人在低雷诺数液体环境中的受力情况进行了分析,建立了机器人运动模型并研究了其多种运动模式.机器人在低雷诺数液体中可以保持水平姿态沿设定路线运动,包括垂直上升、对角上升、直角运动、螺旋上升等3D运动,最大运动速度为1.2 mm/s.通过设计的无线能量传输系统将电能引入到小尺度空间,机器人可通过无线电能驱动其前端的夹持器执行夹取、搬运、释放等微操作.     

片上网络二维和三维结构的通信性能分析

芯片集成技术的迅猛发展,使得片上网络从二维向三维扩展成为可能.研究表明三维片上网络因拓扑维度的增加而缩短了通信距离,极大地提升了网络的平均通信性能.本文对比分析了k-ary-2-mesh网络及其对应的三维网络在最差情形下的通信性能,得出了以下结论:三维网络的平均通信性能虽然更优,但受垂直信道影响其最差情形下的通信性能可...     

A workflow for handling heterogeneous 3D models with the TOUGH2 family of codes: Applications to numerical modeling of CO2 geological storage

This paper is addressed to the TOUGH2 user community. It presents a new tool for handling simulations run with the TOUGH2 code with specific application to CO₂ geological storage. This tool is composed of separate FORTRAN subroutines (or modules) that can be run independently, using input and output files in ASCII format for TOUGH2. These modules have been developed specifically for modeling of carbon dioxide geological storage and their use with TOUGH2 and the Equation of State module ECO2N, dedicated to CO₂-water-salt mixture systems, with TOUGHREACT, which is an adaptation of TOUGH2 with ECO2N and geochemical fluid-rock interactions, and with TOUGH2 and the EOS7C module dedicated to CO₂-CH₄ gas mixture is described. The objective is to save time for the pre-processing, execution and visualization of complex geometry for geological system representation. The workflow is rapid and user-friendly and future implementation to other TOUGH2 EOS modules for other contexts (e.g. nuclear waste disposal, geothermal production) is straightforward. Three examples are shown for validation: (i) leakage of CO₂ up through an abandoned well; (ii) 3D reactive transport modeling of CO₂ in a sandy aquifer formation in the Sleipner gas Field, (North Sea, Norway); and (iii) an estimation of enhanced gas recovery technology using CO₂ as the injected and stored gas to produce methane in the K12B Gas Field (North Sea, Denmark).     

Quantitative assessment of the effectiveness of using display techniques with a haptic device for manipulating 3D objects in virtual environments

Quantitative assessment is made of using two display techniques, providing two different levels of depth perception, in conjunction with a haptic device for manipulating 3D objects in virtual environments. The two display techniques are 2D display, and interactive 3D stereoscopic virtual holography display on a zSpace tablet. Experiments were conducted, by several users of different ages and computer training. The experiments involved selected pointing and manipulation tasks. The speed of performing the tasks using the two display techniques were recorded. Statistical analysis of the data is presented. As expected, the use of interactive 3D stereoscopic display resulted in faster performance of the tasks. The improvement in performance was particularly noticeable for the cases wherein the subjects needed to manipulate the haptic arm to reach objects/targets at different depths, and also when the objects/targets were occluded partially by the obstacles.     

Development and evaluation of a 3D mobile application for learning manual therapy in the physiotherapy laboratory

Teaching manual therapy is one of the most relevant issues in a physiotherapy course. However, knowledge of anatomy is considered fundamental for an effective instruction of this topic. Students should be able to refresh this knowledge while practicing manipulative techniques in the teaching laboratory in an efficient way.In this paper, we present a novel anatomy learning application for mobile devices and describe the successful embedding of such tool into a practical manual therapy course in a laboratory. This application provides students with interactive 3D visualizations of medical imaging on easy-to-carry hand-held devices.We also report two evaluations of this tool. The first one was conducted to evaluate the students' and professors' grade of satisfaction when using our tool. The second one was carried out to determine whether the tool has better learning outcomes than standard methods of teaching anatomy.Students and professors rated the proposed m-learning tool very positively. We also found significant relevance in learning outcomes through the use of this tool. We can conclude that the developed application could be a useful tool for studying manual therapy, and that it could be integrated into the existing physiotherapy curricula.     

The impact of goods-classification and landmarks for spatial knowledge and goods-finding in the elderly within a 3D virtual store

Online shopping has become quite popular since its first arrival on the internet. Although numerous studies have been performed to investigate various issues related to the internet store, some research issues relating to the spatial cognition of the elderly (the fastest growing internet group) when exploring a 3D virtual store still await further empirical investigation. The objective of this study was to examine how elderly users acquire spatial knowledge in an on-screen virtual store. Specifically, the impact of different types of landmarks on the acquisition of spatial knowledge was examined. In addition, in this study, goods-classification was seen as an implicit landmark associated with the acquisition of spatial knowledge. Therefore, it is worth observing the impact during the location of the goods and examining the combined effect with landmarks. The experimental results indicated that landmarks are important for the elderly as they attempt to locate goods within a 3D virtual store, no matter what types are used. However, landmarks are not the only resources for constructing spatial knowledge in a 3D virtual store; the classification of goods is also a good resource and may be more important than landmarks. In addition, the combined effect of goods-classification and landmarks in a 2D image would be best for the elderly in terms of acquired spatial cognition and the location of goods within a 3D virtual store.