基于以太网的分布式发电厂电气监控系统实现

提出了一种基于以太网的分布式发电厂电气监控系统（ECS）,系统由间隔层、通信层、系统层组成。间隔层完成继电保护、模拟量和开关量的采集以及断路器的控制;通信层完成所有实时数据的分类转发,并实现与集散控制系统（DCS）的接口通信;系统层实现全厂电气系统信息的集中处理,提供各种站级应用功能。结合工程实践经验,阐述了一种典型的ECS组网方案,并指出了实践中的一些特殊问题及解决方案。     

Scanning and Address Allocation Delays in Vehicular Communications

WLAN-based roadside-to-vehicle communications is an increasingly popular research trend. This paper examines the applicability of WLANs in the Intelligent Transportation Systems with focus on reducing the scanning phase delay and the address allocation delay. The handover delays become intolerable when the indoor WLAN Access Poins are accessed from by the outdoor mobile nodes at vehicular speeds. In this work, we propose a baseline scheme which calls for passively scanning only the orthogonal channels to reduce the scanning phase delay in the overall handover latency. We argue that the interference free orthogonal channels are ideal for conveying time critical information in vehicular environments. Secondly, this paper evaluates the delays incurred by the Dynamic Host Configuration Protocol (DHCP) in the handover process. The focus on establishing the amount of delay contributed by each DHCP phase and make some meaningful comments at the end. The conclusions made in this paper are based on real-world experiments and tests.     

A novel channel-identification method for wireless communication systems

We present a novel dual-channel identification approach for mobile wireless communication systems. Unlike traditional channel-estimation methods that rely on training symbols, we propose a bent-pipe feedback mechanism which requires the mobile station (MS) to send portions of its received signal back to the base station (BS) for wireless channel identification. Using a filter-bank decomposition concept, we introduce an effective algorithm that can identify both the forward and the reverse channels based only on this feedback information. This new method permits transfer of computational burden from the MS to the resource-rich BS, and leads to significant savings in bandwidth-consuming training signals.     

仿鹰眼大视场高分辨智能成像系统研究

由于鹰眼的特殊视觉机制,其具有大视场搜索、远距离探测和高分辨率成像等优点.基于鹰眼视觉原理,针对弹载光电探测平台,探索一种可以在大视场范围进行目标搜索,同时在关键区域进行目标自动定位和高分辨率成像的智能探测方法.在长波红外谱段,设计了五孔径大视场高分辨成像系统.基于Agent智能控制理论,提出了多传感器智能协同控制方案...     

A Generic Construction of Cartesian Authentication Codes

In this paper, a coding-theory construction of Cartesian authentication codes is presented. The construction is a generalization of some known constructions. Within the framework of this generic construction, several classes of authentication codes using certain classes of error-correcting codes are described. The authentication codes presented in this paper are better than known ones with comparable parameters. It is demonstrated that the construction is related to certain combinatorial designs, such as difference matrices and generalized Hadamard matrices     

Cooperative detection and protection for Interest flooding attacks in named data networking

Named data networking (NDN) is a new emerging architecture for future network, which may be a substitute of the current TCP/IP‐based network, for the content‐oriented data request mode becoming the future trend of development. The security of NDN has attracted much attention, as an implementation of next‐generation Internet architecture. Although NDN is immune to most current attack, it cannot resist the distributed denial of service like attack – Interest flooding attack (IFA) – effectively. IFA takes advantages of the forwarding mechanism of NDN, flooding a large number of malicious Interest packets at quite a high rate, and exploits the network resources, which may cause the paralysis of the network. Taking into account the severity of the destruction, we propose an algorithm to counter such new type of attack. We analyze three properties of IFA, and use them to judge and filter Interest packets. Vector space model and Markov model are used in our method to realize a cooperative detection. Meanwhile, we present the retransmission forwarding mechanism to ensure legitimate user request. The ndnSIM module of ns3 is used for the corresponding simulation, and results of the simulation will be given to show the effectiveness of our algorithm. Copyright © 2014 John Wiley & Sons, Ltd.     

Highly Efficient Three Primary Color Organic Single‐Crystal Light‐Emitting Devices with Balanced Carrier Injection and Transport

Organic single crystals have a great potential in the field of organic optoelectronics because of their advantages of high carrier mobility and high thermal stability. However, the application of the organic single crystals in light‐emitting devices (OLEDs) has been limited by single‐layered structure with unbalanced carrier injection and transport. Here, fabrication of a multilayered‐structure crystal‐based OLED constitutes a major step toward balanced carrier injection and transport by introducing an anodic buffer layer and electron transport layer into the device structure. Three primary color single‐crystal‐based OLEDs based on the multilayered structure and molecular doping exhibit a maximum luminance and current efficiency of 820 cd cm^?2 and 0.9 cd A^?1, respectively, which are the highest performance to date for organic single‐crystal‐based OLEDs. This work paves the way toward high‐performance organic optoelectronic devices based on the organic single crystals.     

Secrecy Outage Performance Analysis of DF Cognitive Relay Network With Co-channel Interference

Wireless Personal Communications - In this paper, we investigate the secrecy outage performance of the decode-and-forward cognitive relay network with the existence of the co-channel interference,...     

Efficient and photostable CsPbl2Br solar cells realized by adding PMMA

Organic-inorganic hybrid perovskite materials demonstrate promising applications in high-efficiency perovskite solar cells (PSCs) with a certified power conversion efficiency (PCE) of 25.5％ (https://www.nrel.gov/pv/cell-efficiency.html).However, intrinsically volatile and thermally unstable nature of the organic cations result in poor thermal stability of organic-inorganic hybrid perovskite materials, hampering the commercialization of organic-inorganic hybrid PSCs[1].All-inorganic CsPbl3-xBrx (x =0-3) perovskites have been attracting great attention in recent years because of their higher thermal stability[2].Among the reported CsPbl3-xBrx perovskites, CsPbl2Br bears a reasonable balance between bandgap and phase stability, thus becomes the most extensively studied material[3-15].Though there are many works aiming at achieving high-efficiency CsPbl2Br PSCs, improving the photostability of CsPbl2Br PSCs is another key for commercialization of all-inorganic PSCs.Intriguingly, it has been reported that CsPbl2Br is susceptible to make light-induced phase segregation, i.e.severe segregation of CsPbl2Br to low-bandgap I-rich and wide-bandgap Br-rich domains via ion diffusion, leading to obvious current-voltage hysteresis and decrease of stabilized power output (SPO)[16-20].Such a light-induced phase segregation can be suppressed by optimizing the interface between perovskite layer and charge-transport layer[18, 19].