面向航空通信应用的边沿触发器教学设计

研究和分析了面向航空通信应用的边沿触发器教学设计。以边沿触发电路实现原理为核心,引导边沿触发机制的探究式学习；以航空机载网络通信为具体应用背景,引入科学研究和工程实现中实际问题,设计曼切斯特码检测系统实验；使得边沿触发器教学成为“知识再创造”的过程和创新实践的新载体,以期培养新工科背景下的独立、创新和实践精神。     

Research on orbital angular momentum communication technology

As the good orthogonality between the different modes of orbital angular momentum (OAM),the application of OAM technology in wireless communication has gained increasing popularity in recent years with great potential for capacity improvement.OAM-based wireless communication technology can effectively improve spectrum utilization,but also brings some challenges.Firstly,the research status and progress of OAM technology in the field of wireless communication were introduced and the relationship between OAM and MIMO technology was compared and analyzed combined with the basic principle of OAM.Moreover,the dispute “Does OAM provides a new dimension?” was concluded.Then,the generation and reception methods of OAM were summarized.The key techniques and application fields were overviewed.Finally,the challenges of the technology in practical application were analyzed and the future development trends and follow-up research directions were point out,which would provide a reference and help for the research in this field.     

ICT and cities revisited

This paper tests whether or not adoption of information and communication technologies (ICT) has offset agglomeration benefits and led to more dispersed spatial structures worldwide. The paper returns to Ioannides et al. (2008) and confirms, first by relying on the Pareto (Zipf) coefficient of the city size distribution as a proxy of spatial dispersion, that the diffusion of fixed telephony has caused more dispersed urban structures worldwide, in other words, greater urban decentralization. Similar causal effects are established for mobile telephony, which are novel, and the internet, which extend previous research. They are confirmed for such alternative measures of dispersion as the Gini coefficient, the Herfindahl index, and the coefficient of variation.     

基于 GA-SVM 算法的通信网络入侵信号自动识别技术

针对当前通信系统入侵行为自动识别技术存在入侵信号样本识别成功率较低、误识别率和漏识别率较高的问题,提出基于 GA-SVM 算法的通信网络入侵信号自动识别技术。利用混沌原理提取通信网络入侵的非平稳信号时域特征,并凭借自回归模型提取对应频域特征,捕捉邻域入侵信号间的非线性时空动作频率,评价相邻行为间的状态关联性,预测入侵信号后续行为,完成入侵信号的识别。实验表明,所提方法识别精度高、误识别率较低,漏识别率非常低,具有可应用于实际的理论价值。     

Political YouTube Channel Reputation (PYCR): Development and validation of a multidimensional scale

Although YouTube is driving change in the news and information environment and earning a reputation as an alternative media, there is a lack of research examining what determines people’s reputational judgments on YouTube’s political channels. Based on in-depth interviews with 32 experts and empirical findings from 380 adults, this research identified factors that impact YouTube users’ reputation perception of political channels and developed a scale. The results showed that the Political YouTube Channel Reputation (PYCR) scale comprises four distinctive dimensions: news credibility, political ideology, user-oriented communication, and quality management. The reliability and validity of the scale were assessed, using exploratory and confirmatory analyses and construct validity. The PYCR scale has a variety of potential applications for users, political influencers, and YouTube, and it can serve as a theoretical framework for future empirical research in this novel and emerging area.     

跨学科对话的思考——以“初诣”传统与明治神宫营建关系的讨论为例

于文化的合流,是景观学科与文化人类学对话的基础。但如何规避静态文化表象的陷阱,统合宏观与微观视角是今后工作的课题。从这一问题意识出发,通过讨论日本初诣传统与明治神宫营建之间的互动关系,揭示影响景观生成的多种互动因素,同时提示对景观实践本身的关注为未来跨学科对话提供新可能。被视为日本传统的初诣的确立与明治神宫的营建,其互相成就的动态发展过程展示了"空间"与"场所"的"调和",并体现了对景观实践反身性思考的重要性。明治神宫的林苑营建,在争议中确立"森林美学",创造了初诣亲身体验的物质性基础。明治神宫背后的美学价值的建立与初诣传统的确立,共同传达了在日本近代化进程中,其遭遇西方文化冲击时对自我的求索。     

Is job performance conditioned by work-from-home demands and resources?

Substantial research has been dedicated to describing remote work, yet the understanding of working from home since the Covid-19 pandemic remains rather limited. While recognising the necessity for exploring employees' perceptions and interaction with technology as the ultimate requirement for a functional work-from-home, this study observes the factors that would determine job performance. Thus, adhering to the Job Demands-Resources theory, we argue that employees' ICT (Information and Communication Technologies) anxiety and smartphone addiction can inhibit their work progress by provoking interruptions in the course and reducing the efficacy, further affecting performance. PLS-SEM (Partial Least Squares - Structural Equation Modelling) was employed to analyse the data collected by 363 employees working from home due to Covid-19 restrictive measures. The results reveal that employees’ reluctance and apprehensiveness related to the use of ICT and their dependency on smartphone usage act as distractions that impact the efficient achievement of work goals. The ensued findings valuably contribute to the relevant body of knowledge, while the implications offer helpful strategies for improving work-from-home. Finally, companies must simplify the transition to the home office, providing employees with job management and tools to ensure uninterrupted and productive working processes.     

Petahertz communication: Harmonizing optical spectra for wireless communications

With the rapid deployment of Next-Generation Networks (NGN), the research community has initiated discussions on an entirely new suite of optical enabling techniques. To pave the way for the development of future wireless networks, this article aims to unify the existing infrared, visible light, and ultraviolet subbands while also exploring the potential of the Petahertz (PHz) band to support extremely bandwidth-thirsty telepresence style applications. Our focus is on the emerging Petahertz Communication (PetaCom) framework, scenario-dependent propagation channels, modulation schemes, system performance, multiple access techniques, and networking. We conclude with a range of PetaCom challenges and open research issues.     

基于5G边缘云的港口统一通信方案研究与实践

5G边缘云具有分布式、灵活组网、快速部署和本地流量分流等优势，在港口等垂直工业领域有很广泛的应用前景，同时对实现港口统一通信也提出了一定的要求。在研究基于5G边缘云的港口统一通信架构的基础上，提出了针对港口现场全域各类要素实现全面感知、支撑自动化业务改造的5G边缘云功能框架。此功能框架能很好地适用于港口场景的有线无线网络融合的统一承载，可作为目前复杂环境下的港口网络统一通信的网络基础设施。最后在某港口码头上对该方案进行了实际验证。     

冰下单载波水声通信试验研究

北极地区战略地位的提高促进了极区各种应用的快速发展，冰下水声通信成为其中一个热点问题。为了研究冰下单载波水声通信性能，在黄海冰区开展冰下试验。重点分析了内嵌锁相环的多通道判决反馈均衡(Multi-channelDecision Feedback Equalization, M-DFE)技术在冰下水声通信中抗多途时延的能力，研究比较了改进比例归一化最小均方(Improved Proportional normalized Least Mean Square, IPNLMS)算法和递归最小二乘(Recursive Least Squares,RLS)算法的均衡性能。试验结果表明IPNLMS和RLS都能克服信道多途效应带来的影响。在牺牲计算复杂度的前提下，RLS具有更好的均衡效果，M-DFE在冰下环境中能够有效消除码间干扰。