The role of domain knowledge in requirements elicitation via interviews: an exploratory study

Requirements elicitation is the first activity in the requirements engineering process. It includes learning, surfacing, and discovering the requirements of the stakeholders of the developed system. Various elicitation techniques exist to help analysts elicit the requirements from the different stakeholders; the most commonly used technique is the interview. Analysts may have domain knowledge prior to the elicitation process. Such knowledge is commonly assumed to have positive effects on requirements engineering processes, in that it fosters communication, and a mutual understanding of the needs. However, to a minor extent, some negative effects have also been reported. This paper presents an empirical study in which the perceived and actual effects of prior domain knowledge on requirements elicitation via interviews were examined. The results indicate that domain knowledge affects elicitation via interview in two main aspects: communication with the customers and understanding their needs. The findings provide insights as to both the positive and negative effects of domain knowledge on requirements elicitation via interview, as perceived by participants with and without domain knowledge, and show the existence of an actual effect on the course of the interviews. Furthermore, these insights can be utilized in practice to support analysts in the elicitation process and to form requirements analysis teams. They highlight the different contributions that can be provided by analysts with different levels of domain knowledge in requirements analysis teams and the synergy that can be gained by forming heterogeneous teams of analysts.     

基于分层聚类和干扰对齐的MIMO链路调度算法

为了降低干扰对齐所需的处理开销,将链路划分为多个簇分别进行处理成为可行的办法之一。针对现有簇划分算 法中运算复杂度较高的问题,本文提出了一种基于最小信干比的簇划分算法。在此基础上,针对所有簇同时通信造成部分簇内链路接收端信干噪比（Signal to interference plus noise ratio,SINR）较低的问题,本文将以链路为单位的调度问题等效为以簇为单位的调度问题,提出了一种基于层次聚类的簇调度算法。理论与仿真实验结果表明,本文所提出的簇划分算法的运算复杂度明显低于现有算法,且相同条件下的系统平均吞吐量更高。同时,本文提出的基于簇层次聚类的调度算法不同程度地提升了各簇内链路接收端的SINR,系统可根据不同的性能需求进行调度策略选择。     

Comparison of the affinity and selectivity of insoluble fibres and commercial proteins for wine proanthocyanidins

The fining action of commercial proteins and insoluble fibres for wine proanthocyanidin (PA) were compared. Fibres were prepared from fresh apple and grape sources, and their corresponding pomaces. PA removal by fibre was via adsorption, and required a higher dose to achieve a fining effect comparable with proteins. A principal component analysis data model revealed that PA molecular mass was significant in defining the fining response, and reflected changes in the proportion of the dominant terminal PA subunits catechin and epicatechin, but not epicatechin-3-O-gallate. For PA extension subunits, changes in epigallocatechin were inversely correlated with epicatechin and epicatechin-3-O-gallate. Generally, the application of proteins and fibres reduced PA molecular mass. Selectivity for PAs by subunit composition was variable between treatments, but differences were minor. This work demonstrates the potential use of fibres as an alternative to proteins in winemaking. Benefits, and possible limitations of such an approach are discussed.     

溶血磷脂的制备、分离、检测及应用研究进展

溶血磷脂(Lysophospholipids)是磷脂在自然降解或磷脂酶的作用下从1位或2位酯键断裂产生的单链脂肪酰磷脂衍生物,是一类仅含有1条脂肪酸链的甘油磷脂。溶血磷脂具有良好的表面活性、乳化性等性能,应用于食品、医药等行业,也作为信号分子参与生命活动。我国在溶血磷脂方面的研究未达到世界先进水平。综述了溶血磷脂的制备方法、分离提取方法、检测方法以及应用的研究进展,以期对溶血磷脂的研究有所帮助。     

超临界CO2中脂肪酶催化甘油解制备单甘酯的研究进展

论述了超临界CO2条件下脂肪酶催化甘油解制备单甘酯的研究进展,并从反应温度、压力、含水量、底物比例、脂肪酶活性等方面对反应的影响进行了探讨.此法具有反应温度低,产品色泽好,无溶剂残留,操作步骤大大简化等优点,有望成为食品用单甘酯最有潜力的生产方法.     

在线红外光谱法研究聚乙烯基苄基氯的交联反应动力学

利用傅里叶变换红外光谱仪(FTIR)在线追踪聚乙烯基苄基氯(PVBCl)与N,N,N′,N′-四甲基-1,6-己二胺(TMHDA)的交联反应历程,考察了反应时间与温度对交联程度的影响。实验结果表明,随着反应时间的延长,交联程度先迅速增大,而后趋于平缓直至不变;反应温度越高,交联程度越大。对反应进行动力学的研究计算结果显示,该交联反应的反应级数n=4,表观活化能Ea=97.2kJ/mol。     

煤气钢管快速镶接技术的研究报告

1 基本情况上海煤气事业已有130余年历史,随着改革开放燃气大发展,上海城区基本燃气化,地下燃气管道已猛增到8000多公里,其中管网占相当比例,长期以来带气钢管的调换镶接(合拢)施工时,采用钢制套筒,外加棱圈焊接的方法完成的。     

脱胶剂对大豆油脱胶效果及磷脂质量的影响

在以前试验得出的大豆油水化脱胶优化条件的基础上，对含磷脂１．９２％的大豆油水化时分别加入乙酸酐、柠檬酸、过氧化氢、磷酸、乙酸、氯化钠、氢氧化钠。结果是：加乙酸酐得到的脱胶油含磷脂量最低，为０．１５％；加过氧化氢得到的磷脂颜色最浅，为Ｇａｒｄｎｅｒ比色５￣＋，而脱胶油的过氧化值最高；加柠檬酸得到的磷脂丙酮不溶物含量最高，为８２．６％，精炼率也是高，为９７．９％；加磷酸得到的磷脂颜色最深，为Ｇａｒｄｎｅｒ比色９￣＋。     

基于蓝牙通讯技术的远程监测和故障诊断系统

将蓝牙通讯技术运用到工程机械的故障诊断系统中,解决了数据采集和传输困难的问题,实现了无线远程实时检测,并完成了无线通讯和网络通讯的无缝连接,为远程故障诊断提供了通讯保障。实验结果显示该系统稳定、可靠,是较为理想的监测和诊断保障系统。     

加强物理实验教学改革 促进应用型创新人才培养

结合高等教育所面临的挑战及英应时措施,强调物理实验是培养学生实践能力和创新能力的一门重要课程.探讨了教学内容、教学方法的改革,指出了物理实验教学改革对培养应用型创新人才的作用.