摘要：Owing to the inherent central information processing and resource management ability,the cloud radio access network(C-RAN)is a promising network structure for an intelligent and simplified sixth-generation(6G)wireless ***,to further enhance the capacity and coverage,more radio remote heads(RRHs)as well as high-fidelity and low-latency fronthaul links are required,which may lead to high implementation *** address this issue,we propose to exploit the intelligent reflecting surface(IRS)as an alternative way to enhance the C-RAN,which is a low-cost and energy-efficient ***,we consider the uplink transmission where multi-antenna users communicate with the baseband unit(BBU)pool through multi-antenna RRHs and multiple IRSs are deployed between the users and *** can conduct either point-to-point(P2P)compression or Wyner-Ziv coding to compress the received signals,which are then forwarded to the BBU pool through fronthaul *** investigate the joint design and optimization of user transmit beamformers,IRS passive beamformers,and fronthaul compression noise covariance matrices to maximize the uplink sum rate subject to fronthaul capacity constraints under P2P compression and Wyner-Ziv *** exploiting the Arimoto-Blahut algorithm and semi-definite relaxation(SDR),we propose a successive convex approximation approach to solve non-convex problems,and two iterative algorithms corresponding to P2P compression and Wyner-Ziv coding are *** results verify the performance gain brought about by deploying IRS in C-RAN and the superiority of the proposed joint design.

摘要：为了实现万物互联,6G蜂窝物联网需要提供低功耗、巨连接和广覆盖的无线接入。通过对6G物联网中大规模接入技术的分析和研究,特别是结合物联网业务的偶发特性,设计了一个基于免授权随机接入协议的新型接入架构,以促进在有限频谱资源内实现高效的大规模接入。所提接入架构包括两个阶段,即联合激活检测与信道估计、数据传输。根据数据传输方向的不同,可以分为上行数据传输和下行数据传输两种方案。由于大规模免授权随机接入情况下基站获取的信道信息具有不确定性,同时考虑6G物联网设备的低功耗需求,因此,两种方案都以系统能量效率为优化目标,分别设计了稳健的接入算法。仿真结果证明了所提方案的有效性和稳健性。

摘要：泵送混凝土专家系统 (PTES)是专家系统技术在泵送混凝土工程上的应用 ,阐述了建立泵送混凝土专家系统的意义 ,并结合系统在设计与实现过程中所采用的基本思想和方法 ,主要介绍了 PTES的系统结构、知识表示。

摘要：本研究主要是定量分析跟骨夹与跟骨的相互作用机理,提高器械使用效率和跟骨骨折的治疗效果。由夹棍组件、头部铰链组件、力传导组件、测力传感器及显示仪表和蓝牙无线传输显示模块组成的无线跟骨夹,具备压力实时检测和数据无线传输显示的功能,采用杠杆原理设计,配套多种可更换的头部铰链,精准的力传导结构设计,便于医生发力,轻巧,使用方便,测量精确度高。目前,该跟骨夹已在临床中使用,能够将医生的手法经验生成力学参数指导临床治疗。

摘要：衡桂高速公路混凝土T梁浇铸过程中,混凝土表面出现水纹等质量缺陷。针对这些质量缺陷,通过原材料设计、配合比调整、施工质量控制等措施进行一系列的技术改进,使得衡桂高速公路混凝土的外观质量得到了改进。