面向长距离量子通信的双光子关联成像技术

量子时域鬼成像利用光子对的时间-频率关联性实现了50km光纤链路上的图像传送,有望应用于量子通信的协议中。然而,现有方案的成像质量较差,成像速度较慢,因此其应用性在一定程度上受到了限制。文章对已有成像方案进行了较大的改进,利用可编程滤波器数字设定待成像信息,进而实现了二维图像信息的自动化实时传送。实验结果证明,改进方案的成像质量和速度均有显著改善,有利于推动量子关联成像在量子通信领域的应用。     

Consumers’ willingness to pay for upcycled foods

Research on food waste reduction suggests that solutions aimed at reducing waste early in the consumption cycle are the most impactful. Based on this premise, food research labs and food manufacturers have started creating and selling foods made from food ingredients that are generally discarded. Such foods, termed upcycled foods, are safe for human consumption and provide a promising solution to reduce food waste. However, the commercial success of this new category of foods will depend on consumers’ acceptance. This research examines a key indicator of acceptance – consumers’ willingness to pay. We find that although consumers are willing to pay less for upcycled foods compared to conventional alternatives, messaging increases consumers’ willingness to pay. Specifically, we find that rational messaging is more effective than emotional messaging. Overall, our findings suggest that upcycled foods may command good acceptance among consumers.     

可重构智能表面辅助的四元数调制无线通信系统

四元数调制(Quaternion Modulation,QMod)是一种新型高传输速率的极化调制(Polarized Modulation,PMod)技术,是未来卫星通信系统中极具潜力的多元调制方案之一。QMod将数据块分成4块,其中两块是传输数据信号,另外两块则映射到极化状态部分。每个极化状态块均有一位比特,那么它们可以产生4个极化状态组合。这些状态组合可以用来确定传输数据块在四元数4个不同维度中的位置,从而获得两位额外的传输比特。相比于传统的PMod技术,QMod有着更高的频谱效率。为了进一步挖掘QMod的潜力,介绍了由可重构智能表面(Reconfigurable Intelligent Surface,RIS)辅助的QMod系统,同时推导了该系统的平均误码率理论上界,并在瑞利信道下进行了BER性能仿真。仿真结果表明,RIS辅助的PMod或者QMod系统即便在较低的SNR情况下仍有良好的BER性能,并且随着RIS单元数的增多,其BER性能会逐步提升。     

Modeling Smart Grid neighborhoods with the ENERsip ontology

The electricity consumption in the buildings sector has been steadily increasing during the last decade, up to the point that energy efficiency in this sector has become a major problem for governments, utilities, customers, and the environment. The foreseen high penetration of distributed micro-generation facilities based on renewables can help to reduce the environmental footprint of buildings and households, although the complexity of managing effectively the electric grid increases dramatically under these conditions. The IEEE 2030 standard for interoperability in the Smart Grid remarks upon the importance of well-defined data models in such complex scenarios and puts emphasis on the benefits of ontologies and OWL (Web Ontology Language) for this purpose. This paper presents an OWL-based ontology that formally defines the vocabulary and taxonomy and captures the engineering and business semantics of this domain of knowledge (i.e., energy efficiency in the so-called nZEN – nearly Zero-Energy Neighborhoods). This ontology has been defined under the scope of the EU (European Union) research project ENERsip. The paper also highlights the main benefits the ontology brought to all the phases of the project life cycle, as well as how future work can make the most out of it.     

Secure and reliable data communication in developing regions and rural areas

Nowadays, despite the ever increasing need of people for staying “connected” at any time and everywhere, in many areas of the world data connection is extremely expensive or even absent. The Global System for Mobile Communication (GSM) network virtually covers all the populated areas of the world and on average, the entire world population have a handheld device capable of accessing at least the GSM services. Therefore, it makes sense to consider the Short Message Service (SMS) as the most popular wireless data service for such devices. In this work, we exploit the SMS as mechanism for data transfer, especially in scenarios where there is no other network coverage than GSM, such as in rural areas and developing regions. In particular, we propose a framework, based on the SMS as transport facility, which enables secure end-to-end data communication in a ubiquitous and pervasive manner. Moreover, we investigated how, by using compression techniques, the overall processing and transmission efforts needed for secure data communication can be effectively reduced, with the obvious consequences also in terms of energy consumption on the involved devices. Finally, we successfully tested the effectiveness of the proposed framework within the context of a proof of concept implementation.     

Towards efficient device-to-device multicast content delivery with social awareness

Frequent content retrieval leads to significant energy consumption in cellular networks. Thereby, device-to-device (D2D) communication is used for proximal content delivery. Be aware that social friends may have common content interests, D2D content delivery is further improved by considering social network. However, how to implement efficient D2D multicast with the aid of social relationship needs further consideration. In this paper, with a proposed architecture on combined networks, the cooperation range of content sharing is investigated for D2D multicast to minimize the average energy consumption of serving a content request. Based on combined networks, a cooperation group formation scheme is proposed. Simulation results verify our analyzes and the advantage of proposed scheme.     

以用户为中心的可见光通信协作传输中训练资源分配算法

以用户为中心的可见光通信协作传输是近年来出现的新架构,这导致虚拟小区之间出现重叠。为避免导频污染问题,每个虚拟小区中的光接入点(AP)或者虚拟小区中选择相同AP的用户发送的训练序列应该是正交的。针对可见光通信中以用户为中心的协作网络,研究训练资源的正交分配问题,提出了一种新的导频分配算法,联合导频分配和用户选择问题,以期最大限度地增加虚拟小区内可被接入的用户数。分析和仿真结果表明,该导频分配方案可以有效改善导频污染问题,提高训练资源利用率,并且相比已有的导频分配方案,性能有所改进。     

无线语音数据通讯系统在云冈矿薄煤层工作面的应用

为了提高大同煤矿集团云冈矿薄煤层工作面的工作效率,降低工作面机电设备与电缆维护难度,开发了一种无线语音数据通讯系统。工业性试验结果表明,该系统无线覆盖无盲区,数据传输流畅,通信误码率≤10-6,语音信号清晰无杂音,设备易于安装维护,满足了工作面综采队的无线语音数据通讯需求。     

IP可视电话系统在企业中的应用

随着IP网络迅猛发展,IP可视电话愈来愈受世人青睐.本文介绍了P可视电话的核心技术--VoIP视频通信的概念和技术原理及其网络构成,以及实现VoIP系统的关键技术,并介绍了企业IP可视电话系统的一个应用实例.     

基于运动蓄电的智能温控衣设计

针对目前市场上的温控衣只能通过市电充电,导致在寒冷的边疆等充电不便的条件下不能长时间使用的现状,设计了一种能运动蓄电、手机调温的智能温控衣。运动蓄电采用人体运动切割磁感线,产生电能给蓄电池充电;手机调温采用蓝牙通信技术,实现温控衣与智能手机的通信;STM32芯片作为控制核心,利用增量式PID算法使温控衣的温度始终保持在用户所设定的温度。测试结果表明,当运动速度达到2m/s(>2m/s)时,机械能转换电能的效率达到(超过)电源适配器充电的效果,解决了温控衣仅依赖市电充电的问题。