基于NPDM的保障系统顶层数据模型研究

介绍了北约产品数据模型(NPDM)的三层体系结构和EXPRESS数据建模语言,着重分析了NPDM顶层数据模型与产品寿命周期的关系,模型中各模式记录的信息内容和模式之间的关系.依据NPDM思想建立了保障系统顶层数据模型,阐述了模型中各模式记录的信息内容,给出了人力与人员、保障设备和保障设施等保障要素的数据结构,为进一步建立保障系统数据模型的打下了基础.     

面向定制化牙科产品的协同设计系统的研究

为了快速设计和制造定制化牙科产品,结合牙科产品的特点,分析了定制化牙科产品协同设计系统中各组织间的协同作用、产品协同设计过程以及协同设计系统的结构;以定制化托槽为例,研究了结合托槽设计及选区激光熔化快速成型的协同设计系统的产品设计制造流程,运用统一建模语言建立了定制化托槽的协同设计过程.实例表明,采用该系统,牙科产品开发商与牙科医生协作实现快速设计并制造定制化产品.     

近红外动脉血液检测中压力对脉搏波的影响

近红外血液检测技术中,透射式光电容积脉搏传感器具有携带有效信息量大的优点,可为动态光谱检测理论提供有效采样数据,但实际应用受到个体差异性的限制.为了克服不同手指端厚度给传感器带来的检测难题,分析了检测结果中压力与直流分量及交流分量之间的关系,通过不同厚度的手指测试实验,指出了存在一个最佳检测区域使得检测到的脉搏波处在最理想状态.     

测量甲烷体积分数的高灵敏度光纤传感器研究

基于气体的红外吸收原理,研究了一种能在复杂环境下测量甲烷气体体积分数的新方法.这种方法可以有效地减小由于光源的不稳定、环境的变化而引起的测量误差.在这种测量方法中设计了一条参考测量光路,此参考测量光路和测量光路同时随环境的变化而变化,通过对待测量气体光路与参考气体测量光路作对比而得出较为准确的待测甲烷气体体积分数.     

冶金规范及工艺卡技术在钢管企业中的应用

首先介绍冶金规范及工艺卡技术的产生与含义,然后从系统需求分析出发,介绍其整体结构、具体内容以及在钢管冶金企业中的地位与应用及其应用效果等。     

基于定子电流小波变换的感应电机速度估计算法的研究

提出一种基于齿槽谐波检测的转速估计算法。首先对感应电机定子电流进行小波变换,得到谱后再利用脊线检测算法提取瞬时频率,然后根据齿槽谐波频率估计转速。将该算法在感应电机无速度传感器直接转矩控制系统中进行了仿真,仿真结果表明,使用小波变换的估计算法不受电机参数的影响,明显提高了电机的转速估计精度,并且在整个转速范围内有效,从而也解决的了在低速范围内,转速估计精度低的问题。     

新型咔唑衍生物密度泛函理论的研究

运用量子化学中的密度泛函和含时密度泛函理论法,计算1种新型咔唑衍生物,以探讨其几何构型、电子结构、前线分子轨道和电子光谱性质。计算结果表明当2-(4-吡啶基)乙烯基的反式构型与咔唑环作用时比顺式稳定,引入取代基后使化合物的HOMO和LUMO之间的能隙降低,吸收光谱红移。电子被激发时,电子从咔唑环向吡啶环转移,说明新型咔唑类化合物具有很好的光学性能,可以作为空穴传输材料。     

SPI success factors within product usability evaluation

This article presents an experience report where we compare 8 years of experience of product related usability testing and evaluation with principles for software process improvement (SPI). In theory the product and the process views are often seen to be complementary, but studies of industry have demonstrated the opposite. Therefore, more empirical studies are needed to understand and improve the present situation. We find areas of close agreement as well as areas where our work illuminates new characteristics. It has been identified that successful SPI is dependent upon being successfully combined with a business orientation. Usability and business orientation also have strong connections although this has not been extensively addressed in SPI publications. Reasons for this could be that usability focuses on product metrics whilst today's SPI mainly focuses on process metrics. Also because today's SPI is dominated by striving towards a standardized, controllable, and predictable software engineering process; whilst successful usability efforts in organisations are more about creating a creative organisational culture advocating a useful product throughout the development and product life cycle. We provide a study and discussion that supports future development when combining usability and product focus with SPI, in particular if these efforts are related to usability process improvement efforts.     

Cops and Robbers from a distance

Cops and Robbers is a pursuit and evasion game played on graphs that has received much attention. We consider an extension of Cops and Robbers, distance k Cops and Robbers, where the cops win if at least one of them is of distance at most k from the robber in G. The cop number of a graph G is the minimum number of cops needed to capture the robber in G. The distance k analogue of the cop number, written c_k(G), equals the minimum number of cops needed to win at a given distance k. We study the parameter c_k from algorithmic, structural, and probabilistic perspectives. We supply a classification result for graphs with bounded c_k(G) values and develop an O(n^2s+3) algorithm for determining if c_k(G)≤s for s fixed. We prove that if s is not fixed, then computing c_k(G) is NP-hard. Upper and lower bounds are found for c_k(G) in terms of the order of G. We prove that

     

A model‐driven decision support system for product risk analysis

Abstract: The paper describes a model‐driven decision support system for risk analysis in product development, based on an European Commission‐funded project. The model can be used to simulate the life cycle of a large batch of products and track products in operation and service phases with consideration of design and manufacturing phases. This provides some useful benefits – in particular, being able to generate composite results when the product life is subject to unpredictable events, which makes the system's behaviour non‐linear. A case study is conducted through a domestic appliance in the field trial from a manufacturing company, and the results indicate that the model can enable developers or manufacturers to understand the behaviour and characteristics of products or systems in the future use and to predict the cost of any changes in the pattern of their life.