What do software practitioners really think about project success: A cross-cultural comparison

Due to the increasing globalization of software development we are interested to discover if there exist significant cultural differences in practitioners’ definition of a successful software project. This study presents the results of a survey in which Chilean software practitioners’ perceptions of project success are compared with previous research with US practitioners. Responses from both groups of practitioners indicate that there is a relationship between team-work and success; our results also indicate that there are similar perceptions related to the importance of job satisfaction and project success. However, Chilean responses suggest that if a practitioner is allowed too much freedom within the work environment, job stress results; this in turn is reflected in increasing demands for both job satisfaction and good environmental conditions. This may indicate the potential for the attribution of failure to conditions outside the team, thus preventing a search for problematic team issues and technical problems. In contrast, the data suggests peer control inside the US teams indicating a less stressful environment.     

Network enforcement as denunciation endorsement? A critical study on legal enforcement in social media

Facing the increasing prevalence of hate speech and other personality rights violations on social media, the legislature tries to improve the law enforcement by involving the social media companies. In 2017, the German Bundestag passed a new law, the Network Enforcement Act (NetzDG), which requires website owners to review the content published on their pages upon it being reported by users and to remove it as soon as possible in the event of a breach of the law. This forces social media operators to establish efficient reporting systems which can create breeding grounds for user denunciation. To get an overview of whether this is really the case, we briefly discuss state surveillance and denunciation and analyse the statistics of content blockings and deletions in five countries (USA, Germany, United Kingdom, Russia and Turkey). In Germany the number of blockings and deletions of content has risen for Facebook, Twitter and YouTube due to the NetzDG, but it has also been found that the majority of reports were unjustified as they did not lead to any restriction or deletion of the content. When comparing the German numbers with those of the other countries investigated, it becomes apparent that after the introduction of the NetzDG in Germany, more content is being blocked and deleted. Also, a comparison of the various laws regulating online content in these countries was conducted. It was found that not only Germany has tightened the regulation of online content and that other countries are also trying to transform the Internet into a more hate free environment.     

实体模型的最佳表示方法

利用几何公差结构块的自由度来表示ＣＡＤ／ＣＡＭ中３Ｄ几何公差的方法，可以直观地、参数化地表示相地参考基准坐标系的公差约束拓扑国。     

用运动合成法实现钻尖的刃磨

将运动合成法用于钻尖刃磨的研究,在分析运动合成机理的过程中,建立了钻尖的位姿方程,应用运动插补实现钻尖的刃磨.该方法提高了钻尖刃磨的自动化程度,保证了刃磨质量.     

胶合式全景环形透镜的设计

介绍了一种新的胶合式全景环形透镜(PAL),改善了全景环形透镜的设计自由度,使全景透镜承担部分校正色差的任务,简化后继透镜组的结构,减少杂散光生成,缩小长焦距全景环形透镜光学系统的体积,并扩大系统的视场.对全景环形透镜的色差和视场进行了理论分析,给出了选择新型全景环形透镜胶合玻璃材料的方法.设计了一个双片胶合式全景环形透镜及其后继转像透镜组,系统焦距为10.3mm,总长170 mm,孔径为f/3.7,PAL最大口径为70mm,光谱范围为0.486-0.656 μm(可见光谱).后继转像镜组由8片透镜构成,系统后焦距(BFL)为17 mm.实验结果证明系统像差校正良好.     

一种数字化多自由度大功率微弧氧化电源的研制

分析了传统的氧化电源在镁合金、铝合金表面处理应用中存在的主要问题,提出了一种应用于镁合金、铝合金微弧氧化的数字化多自由度大功率的双极性不对称脉冲电源。介绍了其工作原理、控制方法、主要结构、试验结果以及现场应用情况。     

提升MIMO干扰信道容量的干扰对齐方案

为提高多用户MIMO干扰信道的容量,提出一种干扰对齐方案。在假设已有天线配置情况不变的条件下,将发送端的原有天线划分为数目相当的2个子组,分别设置不同的天线参数,以消除2个子组天线之间的相关性,从而形成2组独立的传输信道。在接收端将经由2组子信道传输后的接收信号进行合并,间接扩展信号空间维数。基于合并处理后的等效信道传输矩阵,分别利用优化预编码向量夹角和正交投影的方法求解预编码矩阵与联合矩阵,以减少已有干扰对齐方案通过迭代求解所需的运算量。仿真结果表明,在总天线配置情况不变时,该方案可以提高多用户MIMO信道的抗干扰能力。     

Pressure control of hydraulic servo system using proportional control valve

The purpose of this study is to develope a control scheme for the hydraulic servo system which can rapidly control the pressure in a hydraulic cylinder with very short stroke. Compared with the negligible stroke of the cylinder in the system, the flow gain of the proportional pressure control valve constituting the hydraulic servo system is relatively large and the time delay on the response of the valve is quite long. Therefore, the pressure control system, in this study tends to get unstable during operations. Considering the above mentioned characteristics of the system, a two-degree-of-freedom control scheme, composed of the I-PDD²… feedback compensator and the feedforward controller, is proposed. The reference model scheme is used in deciding the parameters of the controllers. The validity of the proposed control scheme is confirmed through the experiments.     

The view of freedom and standardisation among managers in Swedish construction contractor projects

It has been suggested that standardisation improves productivity. Simultaneously, construction contractor project managers are given freedom to run projects as if they were independent firms. If this is a motivating factor for the managers, firms may have to find other ways to improve productivity than to increase standardisation to be able to stimulate their most skilled managers. It could prove important to recognise their need for freedom before they start looking for alternative places of employment.     

基于特征自由度变动的装配误差累积建模研究

利用基于装配功能对于各零件装配特征变动的雅可比矩阵,结合特征自由度和变动理论,建立表示装配功能要求的特征变动与装配零件特征变动联系的数学模型。运用该数学模型,可以定量地表示装配特征的变动对产品装配功能要求的影响,为设计者指出对装配功能影响较大的零件公差并有针对性地对其进行公差分析。