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1.
《Ceramics International》2022,48(1):10-21
Pc-WLEDs are considered to play a spectacular role in future generation light sources in view of their outstanding energy efficiency. In this regard, Eu3+ activated BaY2ZnO5 phosphor was prepared and investigated by XRD, PL and SEM analyses. Rietveld refinement analysis was carried out to confirm the structure of the synthesized phosphor. The prepared phosphor shows an intense red emission around 627 nm under excitation by near UV light. The 5D0-7F2 transition intensity of the prepared phosphor is three times higher compared to the commercial (Y,Gd)BO3:Eu3+ red phosphor. The CIE colour coordinates of BaY2ZnO5:Eu3+ (9mol%) phosphor corresponds to be (0.6169, 0.3742) and it has a high 97.9 % colour purity. The obtained results reveal the utility of BaY2ZnO5:Eu3+ phosphor as an efficient red component in WLEDs, anti-counterfeiting and fingerprint detection applications. 相似文献
2.
Smartphones are being used and relied on by people more than ever before. The open connectivity brings with it great convenience and leads to a variety of risks that cannot be overlooked. Smartphone vendors, security policy designers, and security application providers have put a variety of practical efforts to secure smartphones, and researchers have conducted extensive research on threat sources, security techniques, and user security behaviors. Regrettably, smartphone users do not pay enough attention to mobile security, making many efforts futile. This study identifies this gap between technology affordance and user requirements, and attempts to investigate the asymmetric perceptions toward security features between developers and users, between users and users, as well as between different security features. These asymmetric perceptions include perceptions of quality, perceptions of importance, and perceptions of satisfaction. After scoping the range of smartphone security features, this study conducts an improved Kano-based method and exhaustively analyzes the 245 collected samples using correspondence analysis and importance satisfaction analysis. The 14 security features of the smartphone are divided into four Kano quality types and the perceived quality differences between developers and users are compared. Correspondence analysis is utilized to capture the relationship between the perceived importance of security features across different groups of respondents, and results of importance-satisfaction analysis provide the basis for the developmental path and resource reallocation strategy of security features. This article offers new insights for researchers as well as practitioners of smartphone security. 相似文献
3.
Software updates are an important topic for increasingly software dependent and automated automotive systems. Besides ongoing technical developments, there are also regulatory requirements in development for such systems. We present here an overview of the automotive domain and the particular requirements on update systems, identify potentially suitable update frameworks and evaluate them based on automotive requirements. A focus is on a holistic view of requirements, considering safety, security, and availability. 相似文献
4.
Recently, the Tactile Internet (TI) becomes a new era of the Internet. The TI provides ultra-reliable, ultra-responsive and intelligent network connectivity for delivering real-time control and physical haptic experiences from a remote location. The TI provides a different feeling to human–machine interaction by implementing the real-time interactive systems. In this review article, we discuss a generalized authentication model which can be used to perform authentication procedure among different communicating parties in order to secure remote surgery in the TI environment. By using the proposed authentication model, an authentication protocol can be designed so that an authenticated surgeon can use the robot/robotic arms to perform the surgery securely as well as remotely. Since the application is very critical, the important instructions provided by the surgeon to the robot/robotic arms must not be leaked in between the communication during the surgical procedure. To deal with this emerging research area, a secure mutual user authentication mechanism should be provided between a remote surgeon and the robot/robotic arms so that they can communicate securely using the established session key among them. Further, several security issues and challenges for such kind of communication are also discussed in this article. Finally, we discuss few points that need to be considered as future research works that are related to authentication for securing remote surgery in the TI environment. 相似文献
5.
化石能源的利用弊端下能源安全问题日趋复杂化,成为全球共同的挑战。能源体系的清洁、低碳化转型是破解能源安全问题的关键,这主要是由于能源转型促进了三大转变,加强了能源安全:发展模式由资源依赖转向技术依赖,为共享的能源安全奠定了基础;能源生产由矿物开采转向装备制造,创造了新的经济机遇;能源消费进入电气化时代,保障了可持续能源安全。在此背景下,中国必须坚定能源转型的基本路线,正确把握能源安全的新形势,推动落实全球能源安全的“三大转变”,为国际社会,尤其是其他发展中国家提供必要的、可行的能源转型中国方案。 相似文献
6.
随着社会的不断发展,矿产资源为我国带来了巨大的经济效益,并在社会经济发展中占有重要的地位。但在矿山资源开发的过程中,威胁人身安全的事故经常发生。因此,本文对探矿工程安全措施进行了研究和分析。 相似文献
7.
《Information & Management》2020,57(4):103218
As social media continues to transform firm–customer interactions, firms must leverage customer reactions to generate actionable insights, especially in contexts (e.g., crisis events) where customer reactions are critical. Using the justice theory, we categorize customer reactions of two firms, Home Depot and Target, during the time-frame of a security hack to understand key themes/topics. We then map the themes/topics to customer sentiments in those reactions. We found that customers associate justice with simple procedures than the experience of dealing with the firm. In addition, it is critical for firms to carefully assess and control customer sentiments on social media during crisis events. 相似文献
8.
A directional control method (DCM) for power flows on a set of interface lines between two regions of power system considering static voltage stability margin is developed in this paper. A surface approximation approach is firstly used to obtain the relationship between the interface flow solution and the generation direction of generator (the portion of generation variation in each participating generator to satisfy the desired power increase on the interface and the system loss). Then, an optimization model is built to determine the optimum dispatching scheme of generators. This method not only can control the total power on the interface to satisfy the power demand but also can realize the directional control of power on each interface line based on the needs of operation. The proposed DCM is further extended to determine the optimum dispatching scheme of generators for maximizing the interface flow margin (IFM), which is the active power margin of the key transmission lines between two regions of power system constrained by static voltage stability. A modified continuation power flow (MCPF) is used to show and evaluate the impacts of the DCM on the IFM. The New England 39-bus system and the IEEE 300-bus system have been employed to verify the effectiveness of the DCM. 相似文献
9.
安全管理平台(SMP)是实现安全管理工作常态化运行的技术支撑平台,在实际应用中需要实时处理来自安全设备所产生的海量日志信息。为解决现有SMP中海量日志查询效率低下的问题,设计基于云计算的SMP日志存储分析系统。基于Hive的任务转化模式,利用Hadoop架构的分布式文件系统和MapReduce并行编程模型,实现海量SMP日志的有效存储与查询。实验结果表明,与基于关系数据的多表关联查询方法相比,该系统使得SMP日志的平均查询效率提高约90%,并能加快SMP集中管控的整体响应速度。 相似文献
10.
Various intrusion detection systems (IDSs) have been proposed in recent years to provide safe and reliable services in cloud computing. However, few of them have considered the existence of service attackers who can adapt their attacking strategies to the topology-varying environment and service providers’ strategies. In this paper, we investigate the security and dependability mechanism when service providers are facing service attacks of software and hardware, and propose a stochastic evolutionary coalition game (SECG) framework for secure and reliable defenses in virtual sensor services. At each stage of the game, service providers observe the resource availability, the quality of service (QoS), and the attackers’ strategies from cloud monitoring systems (CMSs) and IDSs. According to these observations, they will decide how evolutionary coalitions should be dynamically formed for reliable virtual-sensor-service composites to deliver data and how to adaptively defend in the face of uncertain attack strategies. Using the evolutionary coalition game, virtual-sensor-service nodes can form a reliable service composite by a reliability update function. With the Markov chain constructed, virtual-sensor-service nodes can gradually learn the optimal strategy and evolutionary coalition structure through the minimax-Q learning, which maximizes the expected sum of discounted payoffs defined as QoS for virtual-sensor-service composites. The proposed SECG strategy in the virtual-sensor-service attack-defense game is shown to achieve much better performance than strategies obtained from the evolutionary coalition game or stochastic game, which only maximizes each stage's payoff and optimizes a defense strategy of stochastic evolutionary, since it successfully accommodates the environment dynamics and the strategic behavior of the service attackers. 相似文献