Fundamental Evaluation of Power Supply and Rectifiers for Wireless Power Transfer Using Magnetic Resonant Coupling

This paper provides a fundamental analysis of a power supply and rectifiers for wireless power transfer using magnetic resonant coupling (MRC). MRC enables efficient wireless power transfer over middle‐range transfer distances. MRC for wireless power transfer should operate at a high frequency in the industry science medical band, such as 13.56 MHz, because the size of the transfer device decreases at higher transfer frequencies. Therefore, the output frequency of the power supply on the transmitting side should be 13.56 MHz. In addition, the rectifier on the receiving side is operated at a high frequency. This paper focuses on the reflected power in the power supply and rectifiers. Thus, the parametric design method is clarified for the power supply, including a low‐pass filter to match the output, the impedance of the power supply with the characteristic impedance of the transmission line. In addition, the effects on the rectifiers of silicon carbide and gallium nitride diodes are confirmed by performing an experiment and a loss analysis.     

重型天车无线遥控技术的应用与探讨

神东煤炭集团公司设备维修中心现有天车存在生产厂家多、控制方式不一、手动操作(有线)容易导致断线和并线的隐患等诸多不利因素。为进一步提升天车运行安全性、系统控制可靠性、人员操作便捷性,便于设备维修保养工作进行,对重型天车无线遥控技术的设计与应用展开探讨。在保留原有功能的前提下,在现有先进无线控制系统上增加无线遥控器,可实现手持遥控器在吊具旁边控制大车、小车和吊钩的起重运行;加装激光报警装置,在2台天车靠近到一定距离时,自动断电来停止天车的运行。天车上安装微机安全、检测、控制系统后,便于扩展天车信息识别、安全监测等功能,该系统具有扩展性强、操作简单、信息化程度高等特点。     

立井井筒安全智能巡检机器人系统的研究

煤矿立井井筒作为矿井通往地面的主要进出口,其周围环境的安全状况以及井筒自身施工质量必须予以足够的重视。为了实时监测记录井筒环境参数、及时对井壁裂纹等状态进行评估和预警,设计了一套立井井筒安全智能巡检机器人系统。以STM32F103ZD为主控制核心,并将提升罐笼作为移动平台,通过高清摄像头和传感器等采集信息,经过WiFi无线传输至上位机,方便工作人员实时查看井筒环境状况以及相关设备运行情况,提高建设期及服役期井筒的安全保障能力。     

基于WaveMesh的煤矿井下无线应力在线监测系统

设计了基于WaveMesh的井下无线应力在线监测系统;系统可在井下完成压力检测并现场显示数据,与监测子站间通过WaveMesh无线通讯技术,可显示每个测点的通讯和压力情况,并将数据通过井下以太环网传送到地面中心站,最终通过监测分析软件实现实时监测和报警。     

J‐divergence‐based Power Allocation in Wireless Sensor Networks with Distributed Detection under Correlated Noises

In this paper, the power allocation problem in a wireless sensor network (WSN) with binary distributed detection is considered. It is assumed that the sensors independently transmit their local decisions to a fusion center (FC) through a slow fading orthogonal multiple access channel (OMAC), where, in every channel, the interferences from other devices are considered as correlated noises. In this channel, the associated power allocation optimization problem with equal power constraint is established between statistical distributions under different hypotheses by using the Jeffrey divergence (J‐divergence) as a performance criterion. It is shown that this criterion for the power allocation problem is more efficient compared to other criteria such as mean square error (MSE). Moreover, several numerical simulations and examples are presented to illustrate the effectiveness of the proposed approach.     

A provable-secure and practical two-party distributed signing protocol for SM2 signature algorithm

Mobile devices are widely used for data access,communications and storage.However,storing a private key for signature and other cryptographic usage on a single mobile device can be challenging,due to its computational limitations.Thus,a number of(t,n)threshold secret sharing schemes designed to minimize private key from leakage have been proposed in the literature.However,existing schemes generally suffer from key reconstruction attack.In this paper,we propose an efficient and secure two-party distributed signing protocol for the SM2 signature algorithm.The latter has been mandated by the Chinese government for all electronic commerce applications.The proposed protocol separates the private key to storage on two devices and can generate a valid signature without the need to reconstruct the entire private key.We prove that our protocol is secure under nonstandard assumption.Then,we implement our protocol using MIRACL Cryptographic SDK to demonstrate that the protocol can be deployed in practice to prevent key disclosure.     

基于序列模型的无线传感网入侵检测系统

随着物联网(IoT)的快速发展，越来越多的IoT节点设备被部署，但伴随而来的安全问题也不可忽视。IoT的网络层节点设备主要通过无线传感网进行通信，其相较于互联网更开放也更容易受到拒绝服务等网络攻击。针对无线传感网面临的网络层安全问题，提出了一种基于序列模型的网络入侵检测系统，对网络层入侵进行检测和报警，具有较高的识别率以及较低的误报率。另外，针对无线传感网节点设备面临的节点主机设备的安全问题，在考虑节点开销的基础上，提出了一种基于简单序列模型的主机入侵检测系统。实验结果表明，针对无线传感网的网络层以及主机层的两个入侵检测系统的准确率都达到了99%以上，误报率在1%左右，达到了工业需求，这两个系统可以全面有效地保护无线传感网安全。     

A survey of 5G technologies: regulatory,standardization and industrial perspectives

In recent years, there have been significant developments in the research on 5th Generation (5G) networks. Several enabling technologies are being explored for the 5G mobile system era. The aim is to evolve a cellular network that is intrinsically flexible and remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. All the stakeholders, such as regulatory bodies, standardization authorities, industrial fora, mobile operators and vendors, must work in unison to bring 5G to fruition. In this paper, we aggregate the 5G-related information coming from the various stakeholders, in order to i) have a comprehensive overview of 5G and ii) to provide a survey of the envisioned 5G technologies; their development thus far from the perspective of those stakeholders will open up new frontiers of services and applications for next-generation wireless networks.     

极端环境下储库控制系统的通信解决方案

在干旱、高温、潮湿、寒冷等环境中使用宽温的自动化产品一般都能达到要求,但在荒野等极端环境中,没有电力供应,没有网络通信的情况时有发生,进而对自动化系统造成致命性的影响。针对该问题,以土耳其地下天然气储库项目为例,提出了使用太阳能供电,运用卫星进行无线通信的方法实现自动化控制系统的正常运行,成功地解决了该问题。     

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.