可穿戴计算机所处的人体振动环境研究

可穿戴计算机所提供的全新的人机交互模式，决定了人体环境即为其工作环境。人体在运动时会产生振动，可穿戴计算机长期在振动环境下使用，其电气性能与可穿戴性能都会受到影响。对走动和跑动两种状态下人体适于放置可穿戴计算机的部位所产生的振动进行了测试和评估。有5名男生参加了测试，被测部位包括人体的上臂、前胸、腹部、腰部和大腿，对每一被测部位在水平方向和竖直方向上产生的振动进行了测试。通过对测试数据在时域和频域上的分析，得到了人体振动环境的特征。     

基于多感官交互的阿尔茨海默老人智能穿戴产品设计研究

目的 研究听觉、触觉与视觉多感官刺激因素介入阿尔茨海默病老人护理的反馈效果,借助智能软硬件技术增强其对音乐的感知,设计多感官交互的老人智能穿戴产品。方法 根据感知替换及通感原理,创建能够将音乐转化为振动及视觉信息的感官替代方法,并通过实验测试分别验证听–触觉和听–触–视觉两类多感官交互原型的可行性。结果 在融合听–触觉的基础上加入视觉设计,可以更好地激发老人的言语行为能力。在收集被试者使用反馈分析结论的基础上设计了一款指尖振动音乐可穿戴设备——指尖钢琴,通过提供以触觉、听觉、视觉融合的多感官体验来促进患者的主动行为。结论 多感官交互产品的设计对改善阿尔茨海默病患者的情绪和主动行为具有一定的效果,对老年患者身体健康和生活质量的提高具有积极意义。     

微型整体式斯特林制冷机系统的计算机仿真优化研究

从热动力学的角度,采用计算机辅助工程设计的方法对微型整体式斯特林制冷机进行整机系统的数值仿真,建立了系统计算机仿真模型,得到了不同行程配比下的内部流动状态,结果与实验得到的数据吻合得较好;从计算和实验两个角度分析了两者行程配比变化同整机性能之间的关系,为旋转式微型斯特林制冷机的几何结构设计提供了重要的参考依据.     

多核下基于远程直接内存访问的高效远程过程调用研究

针对目前基于远程直接内存访问(RDMA)的远程过程调用(RPC)设计在多核背景下存在的性能和扩展性问题,提出了一种新的基于RDMA Write的高效RPC设计方法并对网络文件系统(NFS)提供了支持.重点就设计中的安全性问题和内存管理机制进行了分析,并针对内存有效利用提出了被动和主动两种回收机制.测试结果表明,这种新的...     

基于拓扑数据分析的驾驶疲劳EEG数据处理与优化分析研究

为提高驾驶疲劳脑电(EEG)数据处理与分析的准确性和鲁棒性,提出一种基于拓扑数据分析(TDA)的驾驶人疲劳脑电分析方法。首先利用汽车性能虚拟仿真平台开展驾驶实验,通过驾驶人状态反馈和面部特征视频,标记脑电数据,形成清醒和疲劳二分数据集。之后利用EEGLAB预处理数据,剔除噪声并保留0.3～30 Hz频带,直接从时域EEG数据中提取拓扑特征。此外还提取了经典频域特征α波能量和α/β用于对比分析。最后使用支持向量机进行分类。结果表明,基于持久同源(PH)的拓扑特征取得了高达88.7%的准确率和91.4%的召回率,与经典频域特征性能相当,且对脑电伪影的鲁棒性明显更好,在未剔除EEG伪影的情况下仍取得了87.4%的准确率和89.7%的召回率。综上所述,本文提出的用于驾驶疲劳脑电信号处理与分析的TDA方法抗干扰特性好、处理成本低、经济性高,有助于稳定、高效地处理驾驶人脑电数据并检测驾驶疲劳状态,具有较大的科学实际应用价值。     

塑料模标准件、通用件计算机辅助工艺的设计与研究

论述了塑料模具标准件、通用件制造工艺数据库的开发过程.利用C++编程实现对数据库的检索、管理及用户界面设计,利用SQL Server建立工艺数据库,运用API编程技术完成工序图生成和编辑,采用ADO技术对数据库进行访问,以及系统的功能.     

复杂产品的多学科鲁棒协同设计优化方法研究

为了处理好复杂产品各子系统之间的耦合关系以及各子系统的异构性问题,以协同优化(CO)算法为基础,结合系统不确定分析(SUA)方法和近似不确定传播(IUP)方法,构建了多学科鲁棒协同设计优化算法框架.在设计变量的不确定性能够被概率分布函数描述的情况下,此算法框架能够解决复杂产品的设计优化问题.通过对梳齿式微加速度计的多学科鲁棒协同优化设计算例的计算,验证了此算法在输入参数存在微小扰动的情况下能够有效提高设计解的鲁棒性.     

计算机辅助工艺规程设计系统的体系结构研究

在现代机械制造业中,计算机辅助工艺规程设计(computer aided process planning,简称CAPP)具有重要的理论意义和实际需求。本文旨在建立一个适合企业实际需要的、完善的CAPP系统体系结构,重点在CAPP体系结构理论方面的研究,并在此基础上提出适应应用环境变化的工艺规划方法和能够被企业接受的CAPP系统开发的模式。     

计算机中央处理器液体自循环散热器的试验研究

介绍了一种液体自循环散热器,对研制的原型机进行了比较全面的试验研究.试验结果表明该散热器具有无耗能、无噪声等显著优点,非常适合计算机中央处理器(CPU)使用.可以满足现有的主流计算机CPU的散热要求.与风冷散热器相比较,使用该散热器后,计算机的耗电量和噪声都有明显降低.     

红景天苷在玻碳电极上的伏安行为研究

采用循环伏安法,线性扫描伏安法,微分脉冲伏安法等现代电化学技术研究红景天苷在玻碳电极(GCE)上的电化学行为。在p H=9.0的B–R缓冲液中,红景天苷在0.48V(vs.Ag/Agcl)电位处产生一灵敏的微分脉冲阳极氧化峰。峰电流与红景天苷的浓度在5×10-7mol/L~2×10-5mol/L范围内呈良好的线性关系,检测限为5.5×10-9mol/L。建立了一种简单、快速、灵敏的测定红景天苷的电化学分析方法,该法成功应用于鼠血清和人尿样中红景天苷的测定。     

A wearable computer for physiotherapeutic scoliosis treatment

A posture monitoring system for the treatment of idiopathic scoliosis using electromagnetic and accelerometer technology is discussed. Distributed processors are used to allow parallel execution of data collection. The system is carried by the patient and provides feedback to allow correction of posture during daily activities.     

Strain-sensing fabrics for wearable kinaesthetic-like systems

In recent years, an innovative technology based on polymeric conductors and semiconductors has undergone rapid growth. These materials offer several advantages with respect to metals and inorganic conductors: lightness, large elasticity and resilience, resistance to corrosion, flexibility, impact strength, etc. These properties are suitable for implementing wearable devices. In particular, a sensitive glove able to detect the position and the motion of fingers and a sensorized leotard have been developed. Here, the characterization of the strain-sensing fabric is presented. In the first section, the polymerization process used to realize the strain sensor is described. Then, the thermal and mechanical transduction properties of the strain sensor are investigated and a geometrical parameter to invariantly codify the sensor response during aging is proposed. Finally, a brief outline of ongoing applications is reported.     

Standards for safety related computer systems

This paper discusses current activities and future requirements for standards concerning safety related computer systems. It considers the importance of the safety related computer system market and the significance of standards is discussed before providing a brief review of current safety related standardisation activities. The idea of standards frameworks is elaborated and illustrated with the UK SafeIT proposals. There follows a discussion of the way ahead in safety standardisation and issues identified that have to be addressed in developing policy in this area.     

Reliable timing systems for computer controlled accelerators

Over the past decade the use of computers has set new standards for control systems of accelerators with ever increasing complexity coupled with stringent reliability criteria. In fact, with very slow cycling machines or storage rings any erratic operation or timing pulse will cause the loss of precious particles and waste hours of time and effort of preparation. Thus, for the CERN linac and LEAR (Low Energy Antiproton Ring) timing system reliability becomes a crucial factor in the sense that all components must operate practically without fault for very long periods compared to the effective machine cycle. This has been achieved by careful selection of components and design well below thermal and electrical limits, using error detection and correction where possible, as well as developing “safe” decoding techniques for serial data trains. Further, consistent structuring had to be applied in order to obtain simple and flexible modular configurations with very few components on critical paths and to minimize the exchange of information to synchronize accelerators. In addition, this structuring allows the development of efficient strategies for on-line and off-line fault diagnostics. As a result, the timing system for Linac 2 has, so far, been operating without fault for three years, the one for LEAR more than one year since its final debugging.     

Solution of linear equations for small computer systems

A solution technique, based on Gauss elimination, is described which can solve symmetric or unsymmetric matrices on computers with small core and disk requirement capabilities. The method is related to frontal techniques in that renumbering of the nodes, such as in a finite element mesh, is not required, and the elimination is performed immediately after the equations for a particular node have been fully summed. Only two rows of the matrix need be on core at any step of the solution, but for more efficiency, the program presented here requires all the equations associated with two nodes to be on core. Minimum disk storage is achieved by storing only nonzero entries of the matrix, a single pointing vector for each node, regardless of the number of degrees-of-freedom, and the use of a single sequential file. Special care is taken of the boundary nodes where only the diagonal and the right-hand-side vector are stored. Assembly and elimination for these nodes are avoided completely. The performance of the program is compared with both symmetric and nonsymmetric frontal routines and is shown to be acceptable. The major merit of the method lies in the fact that it can be implemented on small minicomputers. The reduction of core and disk storage inevitably increases the solution time, but the decrease in the output file size also makes the back-substitution and resolution processes more efficient. In some cases, the total solution time can be shorter than for the frontal method due to this property.     

Multi-class queueing models for performance analysis of computer systems

Queueing models, networks of queues in particular, have been found especially useful for estimating the performance of computer systems. Networks of queues with multiple customer classes provide a flexible framework for modelling computer systems, where a rich set of analytical results and techniques are available. When because of the complexity of the system being modelled the analytical results cannot be applied directly, they often point to fairly accurate approximation schemes. In this paper, we present a brief survey of some of the important results and techniques from the theory of multi-class queueing networks. We also present a case study to illustrate how these results and techniques are used in a real-life situation where many of the modelling constraints are violated.     

Fault‐tolerant procedures for redundant computer systems

Real‐time computer systems deployed in life‐critical control applications must be designed to meet stringent reliability specifications. The minimum acceptable degree of reliability for systems of this type is ‘7 nines’, which is not generally achieved. This paper aims at contributing to the achievement of that degree of reliability. To this end, this paper proposes a classification scheme of the fault‐tolerant procedures for redundant computer systems (RCSs). The proposed classification scheme is developed on the basis of the number of counteracted fault types. Table I is created to relate the characteristics of the RCSs to the characteristics of the fault‐tolerant procedures. A selection algorithm is proposed, which allows designers to select the optimal type of fault‐tolerant procedures according to the system characteristics and capabilities. The fault‐tolerant procedure, which is selected by this algorithm, provides the required degree of reliability for a given RCS. According to the proposed graphical model only a part of the fault‐tolerant procedure is executed depending on the absence or presence (type and sort) of faults. The proposed methods allow designers to counteract Byzantine and non‐Byzantine fault types during degradation of RCSs from N to 3, and only the non‐Byzantine fault type during degradation from 3 to 1 with optimal checkpoint time period. Copyright © 2008 John Wiley & Sons, Ltd.     

A new rescheduling method for computer based scheduling systems

Providing a powerful interactive tool for the scheduler to quickly and easily react to the inevitable rescheduling changes is mandatory in today's complex and flexible manufacturing environment. The conventional approaches either employ the regeneration method, which results in unsatisfactory response times, or use. methods that require too much manual intervention for editing operations to be changed. A new rescheduling method is proposed in this paper which addresses these problems. The fundamental scheme of this rescheduling method is based on a scheduling graph as well as concepts of time effect and relationship effect. The scheduling graph is an alternative representation structure of a schedule Gantt chart. The time effect and relationship effect provide functions of (1) identifying those operations that require revision, (2) revising those identified affected operations (via a partial change of the scheduling graph structure) and (3) updating starting and ending times of those revised operations. The rescheduling method both reduces manual intervention of rescheduling to a minimum and permits net change (opposite to regeneration) rescheduling to be achievable. This rescheduling method can be embedded in current computer assistance scheduling systems so as to enhance their effectiveness.