钢管无损检测中的磁致伸缩导波技术试验研究

为了研究磁致伸缩导波技术对输气和输液钢管缺陷的无损检测能力,基于磁致伸缩导波检测技术,设计了磁致伸缩导波检测装置。在同一频率下分别对4根充气和充液管道不同位置的已知缺陷进行导波无损检测试验,其方法是主机产生特定大功率信号,输入到激励传感器,磁致伸缩效应在管道中产生导波,对采集信号进行数据处理,判断管道已知的焊缝及法兰有无及位置。试验结果验证了磁致伸缩导波技术对输气和输液管道无损检测的可行性,证明了该技术能够较好地检测到充气直管焊缝、法兰及支撑结构等管道突变缺陷及位置,但较难应用于弯管的检测,充液管道能够被检出缺陷,但较输气管道的衰减大,检测距离将大幅衰减。     

波浪作用下的海底管道溢油扩散运移规律

为了最大程度减少溢油事故造成的环境污染及经济损失,对海底管道溢油扩散行为的影响因素进行研究.首先,利用流体力学软件建立了波浪条件下的二维有风模型,并进行了验证.其次,通过二维有风模型进行溢油模拟,分析讨论了原油密度、海浪波长、水面风速等因素对溢油扩散的影响.研究结果表明:1)建立的二维有风模型模拟结果比现有文献中模型更...     

全金属定向宽波束L波段干扰机天线阵列设计

为了提升干扰机天线的功率容量、工作带宽和方位辐射覆盖角度，分析归纳了地面设备对空中目标的卫星导航干扰天线设计需求，提出采用顶端加载折叠、加载金属背板的单极子天线作为阵元，设计了1×4线形排列的天线阵列。采用HFSS有限元仿真分析该天线阵列的性能指标，通过观察S参数中S₁₁随天线各调谐参数的变化，进行优化设计分析。结果表明：天线的输入参数对于结构参数变化均会产生一定的影响，但大多数参数的变化对整个带宽的影响并不是很大，而天线距离底板较近则会产生新的频点；提出的天线阵列经过优化后，方位角宽度为158°,俯仰角宽度为26°,最大增益达到9.4 dB,能够实现宽频段、宽角度的定向集中辐射。所设计的全金属宽波束L波段干扰机天线阵列具备结构简单、小型化的特点，十分适合地面卫星导航干扰机天线应用，可为低慢小无人机的一体化干扰天线设计提供借鉴。     

Urban wireless traffic evolution: The role of new devices and the effect of policy

The emergence of new wireless technologies, such as the Internet of Things, allows digitalizing new and diverse urban activities. Thus, wireless traffic grows in volume and complexity, making prediction, investment planning, and regulation increasingly difficult. This article characterizes urban wireless traffic evolution, supporting operators to drive mobile network evolution and policymakers to increase national and local competitiveness. We propose a holistic method that widens previous research scope, including new devices and the effect of policy from multiple government levels. We provide an analytical formulation that combines existing complementary methods on traffic evolution research and diverse data sources. Results for a centric area of Helsinki during 2020–2030 indicate that daily volumes increase, albeit a surprisingly large part of the traffic continues to be generated by smartphones. Machine traffic gains importance, driven by surveillance video cameras and connected cars. While camera traffic is sensitive to law enforcement policies and data regulation, car traffic is less affected by transport electrification policy. High-priority traffic remains small, even under encouraging autonomous vehicle policies. Based on peak hour results, we suggest that 5G small cells might be needed around 2025, albeit the utilization of novel radio technology and additional mid-band spectrum could delay this need until 2029. We argue that mobile network operators inevitably need to cooperate in constructing a single, shared small cell network to mitigate the high deployment costs of massively deploying small cells. We also provide guidance to local and national policymakers for IoT-enabled competitive gains via the mitigation of five bottlenecks. For example, local monopolies for mmWave connectivity should be facilitated on space-limited urban furniture or risk an eventual capacity crunch, slowing down digitalization.     

Human–machine trans roles conflict in the organization: How sensitive are customers to intelligent robots replacing the human workforce?

In organizations facing digital transformation, intelligent technologies are starting to replace the human workforce. At present, managers delegate tasks to an artificial agent and rarely consider the customer reception of such decisions. This arouses tensions between the main stakeholders of the organization. This paper shows that the rash adaptation of the digital workforce may be perceived as an irresponsible innovation that brings negative consequences for companies. If a task is regarded by customers as dedicated to humans, and managers delegate it to machines, a new type of conflict – human-machine trans roles conflict (HMTRC), appears. This paper intends to show that customers are sensitive to HMTRC. This research uses quantitative methods and consists of three stages. First, people were asked to indicate which tasks in an organization should be performed by (a) humans and (b) machines. According to these results, two leaflets for customers were designed (low vs. high HMTRC). In the second stage, standard procedures were used to construct a scale measuring customer reactions to HMTRC on three dimensions: cognitive, emotional and behavioural. Ultimately, the scale and two leaflets were used to check how customers react to different intensities of HMTRC. The research results show that customers are aware when HMTRC occurs and perceive it negatively (cognitive response). Moreover, it evokes negative emotions (emotional response) and prompts customers to take action against the company in which this conflict takes place (behavioural response). The practical contribution of this research is the three-dimensional scale. It may predict customers' reactions to task delegation with different intensities of HMTRC and help build a technologically sustainable organization.     

唐山市规划区土体剪切波速与深度的相关性分析

针对唐山地区岩土勘察及地震工程中剪切波速随深度的经验值尚无通用标准的问题，对规划区209个钻孔剪切波速数据进行研究，通过回归分析法，建立不同地质分区和岩性条件下的回归分析模型，利用决定系数R2检验数据的拟合度，提出研究区的最优回归方程，并利用实际钻孔资料进行验证。结果表明，此次工作建立的回归方程式更准确、精度更高，可成为研究区工程开发建设的重要依据，并在节约成本、缩短工期等方面起到积极作用。     

改进萤火虫算法在Okumura-Hata模型修正中的应用

针对Okumura-Hata模型在不同区域对电波传播衰减的预测与实测难以匹配的问题，提出了一种Okumura-Hata模型修正方法。提取Okumura-Hata模型的各参数作为带约束条件的优化变量，以预测值与实测值的均方根误差和平均误差的加权和构造适应度函数，运用萤火虫算法进行优化实现Okumura-Hata模型在西安市区的本地化。在萤火虫算法中引入了“基因突变”和“优胜劣汰”操作，形成了一种改进型算法。基于大量实测数据的模型修正结果表明，所提方法可使电波损耗的预测值与实测值的均方根误差达到理论最小值9.585 9 dB，具有可行性。与基本萤火虫算法相比，改进的算法全局搜索能力更强，收敛速度更快。     

Automation and the future of work: A social shaping of technology approach

Recent years have seen enormous attention paid to automation and its potential implications for the future of work. This study rejects unhelpful speculation and, instead, poses the question ‘what is shaping automation and its predicted effects?’ In contrast to the technological determinism framing much of the current debate, this study utilises the social shaping of technology (SST) approach, a theoretically informed body of research largely overlooked by sociology of work scholars. Compared with mainstream commentary, which treats technology as separate from the social world, SST facilitates examination of how the development and use of technology are shaped by broader socioeconomic concerns and politics. The analysis presented is based on an understanding of how technology is shaped by existing technology, economics, social relations, gender and the state.