欢迎访问行业研究报告数据库

报告分类

重点报告推荐

当前位置:首页 > 行业导航

找到报告 39653 篇 当前为第 3196 页 共 3966

所属行业:计算机、通信和其他电子设备制造业

  • 31951.陆军团司令部通信网时间序列建模:事件驱动分析

    [信息传输、软件和信息技术服务业,计算机、通信和其他电子设备制造业] [2014-09-26]

    We examine the communication time series of a fully-networked Army coalition command and control organization. The communications and scenario- event data described in this paper were collected at a two-week U.S. Army simulation-based training event. The Mission Command Battle Laboratory at Fort Leavenworth, Kansas, conducted a joint experiment/training exercise focused on the operations of the mission command staff composed of a U.S. Division headquarters (n=51) and subordinate U.K. Brigade headquarters (n=28). The network architecture and digitized nature of the event allowed examination of staff communications in a distributed, network-enabled coalition environment. The participants were active duty Soldiers and officers, organic to their military unit. We used time series analysis to predict the communications record based on an external work variable of the number of important scenario events occurring across time. After taking into account structural features of the time series, we examined the remaining variability in email and phone communications. We found that the exercise scenario events were not a significant predictor of the Divisional communications, which were best fit by an auto-regressive model of order 1. The occurrence of scenario events, however, did predict the Brigade communications time series, which were well fit by a lag dependent variable model. These results demonstrate that Brigade communications responded to and could be predicted by battlefield events, whereas the Division communications were only predicted by their own past values. These results highlight the importance of modeling environmental work events to predict organizational communication time series and suggest that network communications are perhaps increasingly dependent upon battlefield events for lower echelons of command closer to the tactical edge.

    关键词:指挥和控制系统;通信网络;联合军事行动;时间序列分析
  • 31952.表征人工磁导体与传输线模型同相反射带宽的理论极限

    [信息传输、软件和信息技术服务业,计算机、通信和其他电子设备制造业] [2014-09-26]

    We validate through simulation and experiment that artificial magnetic conductors (AMC s) can be well characterized by a transmission line model. The theoretical bandwidth limit of the in-phase reflection can be expressed in terms of the effective RLC parameters from the surface patch and the properties of the substrate. It is found that the existence of effective inductive components will reduce the in-phase reflection bandwidth of the AMC. Furthermore, we propose design strategies to optimize AMC structures with an in-phase reflection bandwidth closer to the theoretical limit.
    关键词:带宽;导线;卫星通信;空间通信;基材
  • 31953.使用复杂独立分量分析的弱同频道干扰通信信号的提取

    [计算机、通信和其他电子设备制造业,信息传输、软件和信息技术服务业] [2014-09-26]

    Independent Component Analysis (ICA) has largely been applied to the biomedical field over the past two decades and only recently extended to the processing of complex non-circular sources. The feasibility and performance of complex ICA to extract a weak co-channel interfering communications signal from a television broadcast signal is investigated in this thesis. The performance of three algorithms, complex maximization of non-Gaussianity (CMN) by Novey et al., RobustICA by Zarzoso et al., and complex fixed-point algorithm (CFPA) by Douglas, over varied interference-to-noise ratios (INR) for a fixed signal-to- interference ratio (SIR) is obtained by simulation. The communication signals examined for the weak interferer are binary phase-shift keying (BPSK), four- level rectangular quadrature amplitude modulation (4-QAM), and 16-level rectangular quadrature amplitude modulation (16-QAM), and the television broadcast signals are North American standard, Advanced Television Systems Committee (ATSC) and European standard, Digital Video Broadcasting - Terrestrial (DVB-T). Improved performance and sensitivity to the prewhitening step present in the ICA implementations are shown as the number of sensors increases.
    关键词:通信和系统;无线电信号;算法;数字录音系统
  • 31954.分布式企业虚拟协作

    [信息传输、软件和信息技术服务业,计算机、通信和其他电子设备制造业] [2014-09-26]

    Breakthroughs in satellite and fiber-optic telecommunication networks and related technologies currently enable almost instantaneous transmission of information across the globe. Many private and public organizations have become used to depending on the global information grid to perform their daily operations. A firm with headquarters in the United States can interact with multiple affiliates and customers located on the other side of the globe in real time. With such technological advances, the need has arisen for virtual collaboration means that allow personnel at geographically diverse sites to interact and communicate effectively. Having the most effective means of virtual collaboration and ensuring they are used in the most effective way are paramount to achieving error-free, real-time communication, a goal that is particularly important for military operations. In this report we address the virtual collaboration needs of organizations whose components have wide geographic distribution, such as U.S. military intelligence organizations or U.S. military operational units.
    关键词:音频会议;协作技术;电脑媒介通讯;会议(通讯)
  • 31955.使用循环功能的通用通信和脉冲压缩雷达波形的调制自动分类

    [计算机、通信和其他电子设备制造业,信息传输、软件和信息技术服务业] [2014-09-26]

    This research develops a feature-based MAP classification system and applies it to classify several common pulse compression radar and communication modulations. All signal parameters are treated as unknown to the classifier system except SNR and the signal carrier frequency. The features are derived from estimated duty cycle, cyclic spectral correlation, and cyclic cumulants. The modulations considered in this research are BPSK, QPSK, 16-QAM, 64-QAM, 8- PSK, and 16-PSK communication modulations, as well as Barker coded, Barker coded, Barker coded, Frank coded, Px49 coded, and LFM pulse compression modulations. Simulations show that average correct signal modulation type classificationC > 90is achieved for SNR > 9dB, average signal modulation family classificationC > 90is achieved for SNR > 1dB, and an average communication versus pulse compression radar modulation classificationC > 90is achieved for SNR > -4dB. Also, it is shown that the classification cation performance using selected input features is sensitive to signal bandwidth but not to carrier frequency. Mismatched bandwidth between training and testing signals caused degraded classification cation ofC 10- 14over the simulated SNR range.
    关键词:自动调制分类阳离子;自动化;通信
  • 31956.基于表面增强拉曼散射的生物传感器

    [计算机、通信和其他电子设备制造业] [2014-09-26]

    Giant Raman scattering in the metal nanostructures that is known as surface-enhanced Raman scattering (SERS) was discovered in the last quarter of the twentieth century. It might be the most important discovery in optics at the end of the century. SERS effect is observed when the investigated substance is deposited onto metal nanoparticles (NPs), clusters of the particles, rough metal surfaces (e.g., chemical etching electrodes), and semi-continuous metal films. SERS has witnessed many successes over the past three decades, owing particularly to its simplicity of use as well as its highly multiplexing capability in biomedical investigations. SERS has emerged as a promising nanosensing technique for in vivo diagnostics. This chapter provides an overview of SERS and its applicability in the field of biosensing. This chapter is divided up as follows: First, the fundamental mechanisms of Raman scattering and SERS are briefly discussed. Second, an assortment of preclinical and clinical SERS applications is discussed. Third, different technologies for SERS-active plasmonic substrate preparation are described. Finally, we consider a new phenomenon associated with the giant enhancement of Raman scattering in the profiled dielectric film.
    关键词:拉曼散射(SERS);生物医学;纳米颗粒
  • 31957.混合型DSRC-PCMS信息系统进行扫雪作业和工作区发展

    [计算机、通信和其他电子设备制造业,信息传输、软件和信息技术服务业] [2014-09-26]

    Congestion and hazardous traffic situations for the drivers on the road can occur around work zones and snowplow operation during the winter season due to low visibility. An information warning system for such environments can improve traffic mobility and thereby driver safety. Intelligent transportation systems (ITS) and other related technologies are being aggressively pursued to devise such automated traffic-information systems. Dedicated short-range communication (DSRC) has been considered as a key enabling wireless communication technology to realize such automated traffic warning systems. DSRC-based traffic-information systems use vehicle-to-vehicle (V2V) and/or vehicle-to-infrastructure (V2I) communication using DSRC technology to acquire and disseminate travel safety information. To take advantage of the disseminated information messages, a vehicle needs to be equipped with DSRC technology.
    关键词:交通安全;通信系统;信息系统
  • 31958.视觉秘密窃听

    [计算机、通信和其他电子设备制造业,信息传输、软件和信息技术服务业] [2014-09-26]

    Private communication may benefit signalers by reducing the costs imposed by potential eavesdroppers such as parasites, predators, prey, or rivals. It is likely that private communication channels are influenced by the evolution of signalers, intended receivers and potential eavesdroppers, but most studies only examine how private communication benefits signalers. Here, we address this shortcoming by examining visual private communication from a potential eavesdropper's perspective. Specifically, we ask if a signaler would face fitness consequences if a potential eavesdropper could detect its signal more clearly. By integrating studies on private communication with those on the evolution of vision, we suggest that published studies find few taxon-based constraints that could keep potential eavesdroppers from detecting most hypothesized forms of visual private communication. However, we find that private signals may persist over evolutionary time if the benefits of detecting a particular signal do not outweigh the functional costs a potential eavesdropper would suffer from evolving the ability to detect it. We also suggest that all undetectable signals are not necessarily private signals: potential eavesdroppers may not benefit from detecting a signal if it co-occurs with signals in other more detectable sensory modalities. In future work, we suggest that researchers consider how the evolution of potential eavesdroppers' sensory systems influences private communication. Specifically, we suggest that examining the fitness correlates and evolution of potential eavesdroppers can help (1) determine the likelihood that private communication channels are stable over evolutionary time, and (2) demonstrate that undetectable signals are private signals by showing that signalers benefit from a reduction in detection by potential eavesdroppers.
    关键词:通信和广播系统;声学探测器;通道;秘密行动
  • 31959.推动全球互联网自由:政策和技术,2013年10月22日

    [信息传输、软件和信息技术服务业,计算机、通信和其他电子设备制造业] [2014-09-26]

    This report provides information about federal and private sector efforts to promote and support global Internet freedom and a description of Internet freedom legislation and hearings from the 113th and 112th Congresses. Three appendixes suggest further reading on this topic and describe censorship and circumvention technologies.
    关键词:互联网;通讯工具;全球市场;大众媒体;社交网络
  • 31960.新兴产业周刊——2014年第35期

    [专用设备制造业,电力、热力、燃气及水生产和供应业,计算机、通信和其他电子设备制造业,医药制造业,水利、环境和公共设施管理业,信息传输、软件和信息技术服务业,汽车制造业,通用设备制造业] [2014-09-26]

    本刊以七大战略性新兴产业——高端装备制造、节能环保、新能源、新材料、新能源汽车、生物、新一代信息技术为研究重点,关注国家高层和各部委的动态,剖析国家和地方的新兴产业政策。本刊设有政策导读、领导讲话、七大战略性新兴产业本周国内外行业动态和重点企业新闻、投资专题四大板块,能够实时监测新兴产业和重点企业动态,把握新兴产业发展方向,研究发展重点,寻求发展机遇。
    关键词:节能环保;新一代信息技术;生物;高端装备制造;新能源;新材料;新能源汽车
首页  上一页  ...  3191  3192  3193  3194  3195  3196  3197  3198  3199  3200  ...  下一页  尾页  
© 2016 武汉世讯达文化传播有限责任公司 版权所有
客服中心

QQ咨询


点击这里给我发消息 客服员


电话咨询


027-87841330


微信公众号




展开客服