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A virtual reality system for arm and hand rehabilitation

Zhiqiang LUO, Chee Kian LIM, I-Ming CHEN, Song Huat YEO

《机械工程前沿(英文)》 2011年 第6卷 第1期   页码 23-32 doi: 10.1007/s11465-011-0202-6

摘要:

This paper presents a virtual reality (VR) system for upper limb rehabilitation. The system incorporates two motion track components, the Arm Suit and the Smart Glove which are composed of a range of the optical linear encoders (OLE) and the inertial measurement units (IMU), and two interactive practice applications designed for driving users to perform the required functional and non-functional motor recovery tasks. We describe the technique details about the two motion track components and the rational to design two practice applications. The experiment results show that, compared with the marker-based tracking system, the Arm Suit can accurately track the elbow and wrist positions. The repeatability of the Smart Glove on measuring the five fingers’ movement can be satisfied. Given the low cost, high accuracy and easy installation, the system thus promises to be a valuable complement to conventional therapeutic programs offered in rehabilitation clinics and at home.

关键词: motion tracking     rehabilitation     optical linear encoder (OLE)     virtual reality    

Optical performance analysis of an innovative linear focus secondary trough solar concentrating system

Xiliang ZHANG, Zhiying CUI, Jianhan ZHANG, Fengwu BAI, Zhifeng WANG

《能源前沿(英文)》 2019年 第13卷 第3期   页码 590-596 doi: 10.1007/s11708-018-0602-y

摘要: The parabolic trough solar concentrating system has been well developed and widely used in commercial solar thermal power plants. However, the conventional system has its drawbacks when connecting receiver tube parts and enhancing the concentration ratio. To overcome those inherent disadvantages, in this paper, an innovative concept of linear focus secondary trough concentrating system was proposed, which consists of a fixed parabolic trough concentrator, one or more heliostats, and a fixed tube receiver. The proposed system not only avoids the end loss and connection problem on the receiver during the tracking process but also opens up the possibility to increase the concentration ratio by enlarging aperture. The design scheme of the proposed system was elaborated in detail in this paper. Besides, the optical performance of the semi and the whole secondary solar trough concentrator was evaluated by using the ray tracing method. This innovative solar concentrating system shows a high application value as a solar energy experimental device.

关键词: secondary parabolic trough solar concentrator     ray tracing method     linear focus     concentration ratio     optical performance    

位移测量光栅干涉仪综述 Special Feature on Precision Measurement and Inst

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

《信息与电子工程前沿(英文)》 2019年 第20卷 第5期   页码 631-654 doi: 10.1631/FITEE.1800708

摘要: 光栅干涉仪是测量精密位移的常用方法。和激光干涉仪相比,光栅干涉仪对空气折射率不敏感且易于实现多自由度测量结构,因此被广泛研究、应用。从光学测量原理角度看,光栅干涉仪历经零差干涉、外差干涉和空间分离式外差干涉3个阶段。与前两者相比,空间分离式外差光栅干涉仪具有能消除光学混叠引起纳米级周期非线性误差的特性,可以获得更高位移测量精度。与此同时,各式各样光栅干涉仪结构被提出,以提高光学细分数、增加量程、提升适用性或实现多自由度位置姿态测量。本文详细总结了近年来增量式位移测量光栅干涉仪的发展,并简述其测量误差相关的研究。

关键词: 光栅干涉仪;光学编码器;位移测量;精密测量    

大相对口径大线视场光学系统的设计

潘君骅

《中国工程科学》 2000年 第2卷 第8期   页码 89-90

摘要:

文章论述了用于红外远距离探测的光学应是全反射式的大相对口径、大视场的离轴非球面系统。给出了一个通光口径为Φ600mm,相对口径1:1.67,线视场为±5°的设计结果。

关键词: 红外探测     相对口径     大视场     离轴系统     非球面    

拓扑优化中采用增材制造填充构件的结构屈曲荷载提升设计 Artical

Anders Clausen, Niels Aage, Ole Sigmund

《工程(英文)》 2016年 第2卷 第2期   页码 250-257 doi: 10.1016/J.ENG.2016.02.006

摘要:

增材制造可实现优质多功能构件所具有的高度复杂几何构型的制备。可以直接制备内含多孔填充的结构部件是其独有特征的一个例证。现有的设计方法还难以充分利用这一设计自由度,直接获得类似结构的设计。本文将展示涂层方法 (coating approach) 的拓扑优化方法来作为多孔填充构件的设计方法,所设计的构件具有显著改进的临界屈曲载荷,从而使得整体结构部件的稳定性增强。传统的柔顺性拓扑优化方法极少在数学模型中考虑构件的屈曲约束,稳定性要求通常要经过后续的校核与改进过程满足。这一后续过程往往只能获得次优设计。本文所展示的方法弥补了传统柔顺性拓扑优化模型中难以考虑构件屈曲约束的缺陷。利用涂层拓扑优化方法与传统柔顺性拓扑优化同时对经典的MBB 梁进行设计,并采用熔丝增材制造技术对设计结果进行了制备。实验结果验证了涂层方法的数学模型的正确性。由于填充材料的性质,在相同条件下,涂层优化得到的多孔填充结构的屈曲载荷比传统优化得到的实体结构高四倍以上。

关键词: 增材制造     填充构件     拓扑优化     屈曲    

病理状态下肠道微生态的调节

王玉兰, 王保红, 吴俊芳, 江向洋, 唐惠儒, Ole H. Nielsen

《工程(英文)》 2017年 第3卷 第1期   页码 83-89 doi: 10.1016/J.ENG.2017.01.013

摘要:

人类微生态是寄居在人体中的微生物聚集体,且主要存在于胃肠道(GIT) 中。肠道微生态随着人体发育而演化,并在人类健康和疾病中起着重要作用。近年来,由于微生态会影响宿主代谢、生理学和免疫系统发育,而且微生态紊乱可能导致许多疾病,其越来越受到人们的关注。肠道微生态可能与恶性肿瘤有一定联系,如胃癌和结直肠癌;也可能与其他一些疾病有关,如非酒精性脂肪肝(NAFLD)、被称为工业化世界“生活方式疾病”的肥胖和糖尿病、冠心病以及中枢神经系统紊乱。虽然分子技术革命为我们更准确地研究肠道微生态提供了必要的工具,但是我们需要更精确地阐明其与某些人类疾病病理变化的关系,明确微生态在不同疾病中的作用是新的治疗策略发展的基础。本文概述了肠道微生态对人类健康的重要影响以及调整肠道菌群结构的潜在用途,如菌群移植用于治疗耐药艰难梭菌(C. difficile) 的感染。通过微生态干预调整肠道区域以改善人类健康的概念虽刚刚兴起,但其治疗意义显著。因此,抑制有害菌、促进有益菌可能会保护人类健康,并且这些努力将为探索发展更加合理的治疗方案打下基础。

关键词: 肠道菌群     疾病     菌群调节    

长大海底隧道——认识并克服运营和施工物流困难问题 Article

Gareth Mainwaring, Tor Ole Olsen

《工程(英文)》 2018年 第4卷 第2期   页码 249-253 doi: 10.1016/j.eng.2018.03.004

摘要:
长大海底隧道尤其是运输用长大海底隧道,并非寻常的基础设施工程。尽管长大海底隧道的设计和施工相当耗时,但一旦建成投运,便可形成重要的越海通道。此类隧道建在海底,会面临独特的挑战,包括一系列施工和运营方面的复杂问题。此类挑战与最终隧道路径缺少中间辅助点有关。地下隧道(如穿越阿尔卑斯山之类山脉的隧道)也面临类似问题。本文将探讨长大海底隧道设计和施工方面的关键问题,并采用其他工程专业所用的成熟技术来提出可能性解决方案。

关键词: 海峡隧道     越海通道     消防和生命安全     竖井     重力结构    

Hybrid embedding and joint training of stacked encoder for opinion question machine reading comprehension

Xiang-zhou Huang, Si-liang Tang, Yin Zhang, Bao-gang Wei,huangxiangzhou@zju.edu.cn,siliang@zju.edu.cn,yinzh@zju.edu.cn

《信息与电子工程前沿(英文)》 2020年 第21卷 第9期   页码 1267-1412 doi: 10.1631/FITEE.1900571

摘要: Opinion question (MRC) requires a machine to answer questions by analyzing corresponding passages. Compared with traditional MRC tasks where the answer to every question is a segment of text in corresponding passages, opinion question MRC is more challenging because the answer to an opinion question may not appear in corresponding passages but needs to be deduced from multiple sentences. In this study, a novel framework based on is proposed to address such problems, in which a new hybrid embedding training method combining text features is used. Furthermore, extra attention and output layers which generate auxiliary losses are introduced to jointly train the stacked recurrent . To deal with imbalance of the dataset, irrelevancy of question and passage is used for . Experimental results show that the proposed method achieves state-of-the-art performance. We are the biweekly champion in the opinion question MRC task in Artificial Intelligence Challenger 2018 (AIC2018).

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 1-31 doi: 10.1007/s11465-020-0602-6

摘要: Optical interferometry is a powerful tool for measuring and characterizing areal surface topography in precision manufacturing. A variety of instruments based on optical interferometry have been developed to meet the measurement needs in various applications, but the existing techniques are simply not enough to meet the ever-increasing requirements in terms of accuracy, speed, robustness, and dynamic range, especially in on-line or on-machine conditions. This paper provides an in-depth perspective of surface topography reconstruction for optical interferometric measurements. Principles, configurations, and applications of typical optical interferometers with different capabilities and limitations are presented. Theoretical background and recent advances of fringe analysis algorithms, including coherence peak sensing and phase-shifting algorithm, are summarized. The new developments in measurement accuracy and repeatability, noise resistance, self-calibration ability, and computational efficiency are discussed. This paper also presents the new challenges that optical interferometry techniques are facing in surface topography measurement. To address these challenges, advanced techniques in image stitching, on-machine measurement, intelligent sampling, parallel computing, and deep learning are explored to improve the functional performance of optical interferometry in future manufacturing metrology.

关键词: surface topography     measurement     optical interferometry     coherence envelope     phase-shifting algorithm    

Design and analysis of linear oscillating motor for linear pump application-magnetic field, dynamics

Zongxia JIAO,Tianyi WANG,Liang YAN

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 351-362 doi: 10.1007/s11465-016-0407-9

摘要:

A linear oscillating motor is an electromagnetic actuator that can achieve short-stroke reciprocating movement directly without auxiliary transmission mechanisms. It has been widely used in linear pump applications as the source of power and motion. However, because of the demand of high power density in a linear actuation system, the performance of linear oscillating motors has been the focus of studies and deserves further research for high power density. In this paper, a general framework of linear oscillating motor design and optimization is addressed in detail, including the electromagnetic, dynamics, and thermal aspects. First, the electromagnetic and dynamics characteristics are modeled to reveal the principle for optimization. Then, optimization and analysis on magnetic structure, resonant system, and thermal features are conducted, which provide the foundation for prototype development. Finally, experimental results are provided for validation. As a whole, this process offers complete guidance for high power density linear oscillating motors in linear pump applications.

关键词: linear oscillating motor     linear pump     magnetic field     motor optimization    

Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 3-17 doi: 10.1007/s11465-017-0408-3

摘要:

It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pa·s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

关键词: precision glass molding     optical lens     constitutive modeling     optimization     manufacturing chain     Industry 4.0    

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

《环境科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 320-324 doi: 10.1007/s11783-009-0030-7

摘要: The best-fit equations of linear and non-linear forms of the two widely used kinetic models, namely pseudo-first-order and pseudo-second-order equations, were compared in this study. The experimental kinetics of methylene blue adsorption on activated carbon was used for this research. Both the correlation coefficient () and the normalized standard deviation Δ(%) were employed as error analysis methods to determine the best-fitting equations. The results show that the non-linear forms of pseudo-first-order and pseudo-second-order models were more suitable than the linear forms for fitting the experimental data. The experimental kinetics may have been distorted by linearization of the linear kinetic equations, and thus, the non-linear forms of kinetic equations should be primarily used to obtain the adsorption parameters. In addition, the Δ(%) method for error analysis may be better to determine the best-fitting model in this case.

关键词: adsorption     pseudo-first order     pseudo-second order     kinetic model     linear method     non-linear method    

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

《中国工程科学》 2001年 第3卷 第9期   页码 86-94

摘要:

综合介绍了近年国外关于低衰耗的色散补偿光纤,非零色散位移光纤,用于恶劣环境的碳涂覆和氮化硅涂覆光纤的研究;光纤带制造技术包括光纤带的结构、涂层、性能、生产工艺,大芯数光纤带状光缆包括层绞式松管、中心松管式、骨架式、干缆芯带状光缆的设计制造技术的最新进展。

关键词: 光纤通信     低衰耗光纤     光纤带     光纤带状光缆    

成像光学工程面临的光学问题

潘君骅

《中国工程科学》 2000年 第2卷 第3期   页码 32-35

摘要:

文章简单论述了现代成像光学主要领域的情况,指出非球面反射系统是发展的必然趋势。讨论了加工与检验方面的基本情况及应着重深人研究的问题。对镜坯材料也提了一点看法。

关键词: 成像光学     非球面反射镜     光学设计     光学加工与检验    

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

《能源前沿(英文)》 2019年 第13卷 第4期   页码 673-683 doi: 10.1007/s11708-019-0630-2

摘要: The optical performance of a receiver has a great influence on the efficiency and stability of a solar thermal power system. Most of the literature focuses on the optical performance of receivers with different geometric shapes, but less research is conducted on the effects of critical geometric parameters. In this paper, the commercial software TracePro was used to investigate the effects of some factors on a conical cavity receiver, such as the conical angle, the number of loops of the helical tube, and the distance between the focal point of the collector and the aperture. These factors affect the optical efficiency, the maximum heat flux density, and the light distribution in the conical cavity. The optical performance of the conical receiver was studied and analyzed using the Monte Carlo ray tracing method. To make a reliable simulation, the helical tube was attached to the inner wall of the cavity in the proposed model. The results showed that the amount of light rays reaching the helical tube increases with the increasing of the conical angle, while the optical efficiency decreases and the maximum heat flux density increases. The increase in the number of loops contributed to an increase in the optical efficiency and a uniform light distribution. The conical cavity receiver had an optimal optical performance when the focal point of the collector was near the aperture.

关键词: parabolic collector     conical cavity receiver     critical geometric parameters     optical performance    

标题 作者 时间 类型 操作

A virtual reality system for arm and hand rehabilitation

Zhiqiang LUO, Chee Kian LIM, I-Ming CHEN, Song Huat YEO

期刊论文

Optical performance analysis of an innovative linear focus secondary trough solar concentrating system

Xiliang ZHANG, Zhiying CUI, Jianhan ZHANG, Fengwu BAI, Zhifeng WANG

期刊论文

位移测量光栅干涉仪综述

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

期刊论文

大相对口径大线视场光学系统的设计

潘君骅

期刊论文

拓扑优化中采用增材制造填充构件的结构屈曲荷载提升设计

Anders Clausen, Niels Aage, Ole Sigmund

期刊论文

病理状态下肠道微生态的调节

王玉兰, 王保红, 吴俊芳, 江向洋, 唐惠儒, Ole H. Nielsen

期刊论文

长大海底隧道——认识并克服运营和施工物流困难问题

Gareth Mainwaring, Tor Ole Olsen

期刊论文

Hybrid embedding and joint training of stacked encoder for opinion question machine reading comprehension

Xiang-zhou Huang, Si-liang Tang, Yin Zhang, Bao-gang Wei,huangxiangzhou@zju.edu.cn,siliang@zju.edu.cn,yinzh@zju.edu.cn

期刊论文

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

期刊论文

Design and analysis of linear oscillating motor for linear pump application-magnetic field, dynamics

Zongxia JIAO,Tianyi WANG,Liang YAN

期刊论文

Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

期刊论文

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

期刊论文

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

期刊论文

成像光学工程面临的光学问题

潘君骅

期刊论文

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

期刊论文