Telecom cable is an insulated strand of wires used to transmit high frequency electrical signals over long distances. Previously, telecom signal transmission used only analog signals, which were transferred through metallic wires, mainly copper wires. However, most of the telecom signal transmission in the present scenario incorporates digital signals. The telephone and cable companies still use the same metallic cables along with fiber optic cables, which are more efficient for carrying the digital signal transmission over a long distance with reduced signal loss.

关键词：电信电缆；绝缘链；传输；高频电信号；电信信号传输；模拟信号

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Evaluating the performance claims of wideband communication systems will require a RF channel model that arises from the Navy's needs. U.S. Navy shipboard systems contend with surface and evaporation ducts, which create complex propagation environments that can significantly impact system performance. The work developed under this effort is an automated model that can characterize the effect of anomalous propagation conditions on system performance. The limitations of this model need to be understood so that users can determine the applicability of this model for their needs. Future work for this project includes developing and optimizing the automated model and validating the model based on comparisons to other deterministic models along with a comparison to experimental data. The work presented in this document shows the theory that was used to develop an automated channel model that will be validated in the second year of the effort. The design of a wideband channel sounder was presented and the channel sounder will be used to collect a unique set of channel measurements over long-range paths. The experimental validation test plan was developed and measurements will be collected during the second year of this effort.

关键词：大气；自动模式；射频；船上

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本文分别从2013-2014年中国软件产业发展状况、产业竞争分析、产业发展预测等几个方面进行了分析。

关键词：软件产业；发展状况；产业竞争分析；产业发展预测

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The main purpose of the study is to carry out a correlated study of global and seasonal scintillation morphology in the equatorial region using a coincident observation that occurred on 24 Mar 2000 between the irregularity structure observed by ROCSAT-1 and the scintillation experiment carried out at the Ascension Island. The two sets of data were studied separately first, and then compared correlatively for their causal relationship. The results show the reasonable scintillation level at coincident time to indicate a direct relationship between the irregularity structure and the scintillation in both temporal and amplitude variations. Second, since the ionospheric density irregularities are the source of ionospheric radiowave scintillation that affects space communication and navigation, in-depth investigation for the cause of ionospheric irregularities has been carried out. In conclusion, our analysis indicates that the seeding of deep atmospheric convection represented by OLR for the ionospheric irregularity occurrences has not happened as frequently as it was thought.

关键词：电离层闪烁；大气化学；大气科学；通信和广播系统;

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本文分别从2013-2014年中国软件外包市场概述、产业竞争等几个方面进行了分析。

关键词：软件外包；市场概述；产业竞争分析

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本文分别从2013-2014年中国数据中心市场概况、应用投资预测等几个方面进行了分析。

关键词：数据中心；IT应用；市场概况；应用投资预测

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本文分别从2013-2014年中国商业分析软件市场概述、市场竞争等几个方面进行了分析。

关键词：商业分析软件；市场概述；市场竞争分析

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本文分别从2013-2014年全球软件市场概述、市场竞争格局分析等几个方面进行了分析。

关键词：全球软件；市场概述；竞争格局分析

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A series of tests of the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) pressure cube were conducted during third quarter 2011 at NASA Langley Research Center (LaRC) in the Combined Loads Test facility (COLTS). This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. The AE signals of the later tests are consistent with the final failure progression through two of the pressure cube panels. Calibration tests and damage precursor AE indications, from preliminary checkout pressurizations, indicated areas of concern that eventually failed. Hence those tests have potential for vehicle health monitoring.

关键词：大气压力;失效分析;疲劳（材料）;试验设施

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The phenomenology of imaging in the millimeter-wave (MMW) and submillimeter-wave (SMMW)/terahertz (THz) frequency regimes is investigated and described. The primary factors related to imaging in these frequency regimes are phenomenologically driven and involve trade-offs between spatial (angular) resolution; the impact of atmospheric and obscurant attenuations such as fog, dust, and concealing materials; and system sensitivity requirements. Minimum system sensitivity requirements for adequate imaging in three important military/security scenarios are identified and described in terms of minimum apparent temperature differences between targets and their backgrounds. Mathematical equations for calculating the minimum system sensitivity (noise equivalent power NEP) per root hertz (Hz) required to provide image frames with enough signal-to-noise ratio (SNR) to produce good imagery at video frame rates are derived.

关键词：图像;毫米波;方程;数学;灵敏度;信噪比

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