Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn consid...Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the lnternet of Energy Things （IoET） in order to make DSM practicable by basing it on the latest wireless communication technology： the low-power wide-area network （LPWAN）. The primary advantage of LPWAN over general packet radio service （GPRS） and area Internet of Things （loT） is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN tech- nologies of narrow-band Internet of Things （NB-IoT） and Long Range （LORa） technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios.展开更多
基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器...基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器件的研究与应用.本文首先阐述了MRAM的基本原理与发展历程,着重介绍了写入技术的演变以及磁各向异性的改善.然后总结了近期在3个领域的研究成果:(1)学术界开展了大量研究以探讨制备工艺和器件结构等因素对界面垂直磁各向异性的影响;(2)CoFeB-MgO双界面结构被提出,该结构在不增大写入电流的前提下增强了磁隧道结的热稳定性势垒;(3)新兴的自旋轨道矩写入方式引起了广泛的关注,该技术有望解决传统自旋转移矩所面临的速度瓶颈和势垒击穿风险.最后,本文扼要地介绍了STT-MRAM在芯片设计领域的最新进展.展开更多
在6LoWPAN(IPv6 over Low-power Wireless Personal Area Network)的基础上,该文提出应用于物联网的寻址策略,实现基于IEEE 802.15.4协议的底层异构网络与互联网的实时通信。寻址策略包括IPv6地址自动配置和报头压缩。采用的分层地址自...在6LoWPAN(IPv6 over Low-power Wireless Personal Area Network)的基础上,该文提出应用于物联网的寻址策略,实现基于IEEE 802.15.4协议的底层异构网络与互联网的实时通信。寻址策略包括IPv6地址自动配置和报头压缩。采用的分层地址自动配置策略,首先在底层网络内部允许节点使用16位短地址导出的链路本地地址进行数据分组传输,该链路本地地址需通过执行基于分簇的重复地址检测机制保证唯一性;其次,每个底层网络中的Sink节点通过上层IP路由器获取全球路由前缀,并与接口标识符相结合,形成Sink节点的全球地址,实现底层网络与互联网的数据交换。同时,通过在报头压缩编码中植入链路本地地址和全球地址控制位,提出了一种适用于物联网应用的报头压缩方案IIPHC(IoTs IPv6 Header Compression)。如果地址类型为链路本地地址,则采用简单灵活的IIPHC1方案,如果地址类型为全球地址,则采用相对复杂但有效的IIPHC2方案。仿真及测试结果表明,基于6LoWPAN的物联网寻址策略在网络开销、时延、吞吐量、能耗等性能方面存在一定的优越性。展开更多
基金This work was supported by the National High Technology Research and Development Program of China （2014AA051901）, the International S＆T Cooperation Program of China （2014DFG62670）, and the National Natural Science Foundation of China （51207077, 51261130472, and 51577096）. Thanks for the contributions of Dr. Yibao Jiang and Dr. Xiaoshuang Chert on this paper.
文摘Under intense environmental pressure, the global energy sector is promoting the integration of renewable energy into interconnected energy systems. The demand-side management （DSM） of energy systems has drawn considerable industrial and academic attention in attempts to form new flexibilities to respond to variations in renewable energy inputs to the system. However, many DSM concepts are still in the experimental demonstration phase. One of the obstacles to DSM usage is that the current information infrastructure was mainly designed for centralized systems, and does not meet DSM requirements. To overcome this barrier, this paper proposes a novel information infrastructure named the lnternet of Energy Things （IoET） in order to make DSM practicable by basing it on the latest wireless communication technology： the low-power wide-area network （LPWAN）. The primary advantage of LPWAN over general packet radio service （GPRS） and area Internet of Things （loT） is its wide-area coverage, which comes with minimum power consumption and maintenance costs. Against this background, this paper briefly reviews the representative LPWAN tech- nologies of narrow-band Internet of Things （NB-IoT） and Long Range （LORa） technology, and compares them with GPRS and area IoT technology. Next, a wireless-to-cloud architecture is proposed for the IoET, based on the main technical features of LPWAN. Finally, this paper looks forward to the potential of IoET in various DSM application scenarios.
文摘基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器件的研究与应用.本文首先阐述了MRAM的基本原理与发展历程,着重介绍了写入技术的演变以及磁各向异性的改善.然后总结了近期在3个领域的研究成果:(1)学术界开展了大量研究以探讨制备工艺和器件结构等因素对界面垂直磁各向异性的影响;(2)CoFeB-MgO双界面结构被提出,该结构在不增大写入电流的前提下增强了磁隧道结的热稳定性势垒;(3)新兴的自旋轨道矩写入方式引起了广泛的关注,该技术有望解决传统自旋转移矩所面临的速度瓶颈和势垒击穿风险.最后,本文扼要地介绍了STT-MRAM在芯片设计领域的最新进展.
文摘在6LoWPAN(IPv6 over Low-power Wireless Personal Area Network)的基础上,该文提出应用于物联网的寻址策略,实现基于IEEE 802.15.4协议的底层异构网络与互联网的实时通信。寻址策略包括IPv6地址自动配置和报头压缩。采用的分层地址自动配置策略,首先在底层网络内部允许节点使用16位短地址导出的链路本地地址进行数据分组传输,该链路本地地址需通过执行基于分簇的重复地址检测机制保证唯一性;其次,每个底层网络中的Sink节点通过上层IP路由器获取全球路由前缀,并与接口标识符相结合,形成Sink节点的全球地址,实现底层网络与互联网的数据交换。同时,通过在报头压缩编码中植入链路本地地址和全球地址控制位,提出了一种适用于物联网应用的报头压缩方案IIPHC(IoTs IPv6 Header Compression)。如果地址类型为链路本地地址,则采用简单灵活的IIPHC1方案,如果地址类型为全球地址,则采用相对复杂但有效的IIPHC2方案。仿真及测试结果表明,基于6LoWPAN的物联网寻址策略在网络开销、时延、吞吐量、能耗等性能方面存在一定的优越性。
