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91.
张文  张毅  满毅  陈晓峰 《电信科学》2011,27(8):117-121
提出一种集成共享平台,是一种可对外提供多种基本且可扩展接口,以适应不同接口的应用系统。基于此平台,多个系统之间可以相互调用多种服务,提高服务管理功能的同时进行无障碍的信息交互;及时发现分析系统交互异常信息,实现智能维护管理。当出现新的接口协议时,只需针对所述平台进行一次新接口协议适配器的开发,即可完成新接口的接入,提高了平台开发效率,降低了开发维护成本。本平台将传统的点对点的应用方式改为多对多的总线方式,实现了各系统间简单便捷的信息交互,优化了各系统间的架构,易于管理和维护,减少了接入系统的接口改造工作。  相似文献   
92.
Low conversion-loss millimeter-wave fourth subharmonic (SH) mixer designs are proposed in this paper. A millimeter-wave (35 GHz) fourth SH mixer with four open/shorted stubs is designed and measured. The conversion loss is less than 15 dB within a 2.4-GHz bandwidth. The minimum loss is 11.5 dB at the center frequency. By replacing two of the shunt stubs with a dual-frequency in-line stub consisting of newly developed compact microstrip resonating cells (CMRCs), the performance of the SH mixer is improved significantly. At 35 GHz, the conversion loss of this new fourth SH mixer is as low as 6.1 dB with a 3-dB bandwidth of 6 GHz. The conversion loss in the whole Ka-band (26.5-40 GHz) is less than 16 dB. The proposed fourth SH mixer incorporating with CMRCs provides a low-cost high-performance solution for RF subsystem design.  相似文献   
93.
A novel transistor oscillator incorporating a compact microstrip resonant cell (CMRC) as its terminating resonance is proposed. Adjusting the dimensions of the cell, it is possible that the fundamental frequency can be positively fed back and the second harmonic negatively fed back at the input port of the oscillator. The fundamental output is enhanced with the second harmonic being suppressed. The output power of the proposed CMRC oscillator is 14.7 dBm at 2.5 GHz with 27.1 dB rejection of the second harmonic, outperforming the conventional microstrip termination with a 40% size reduction  相似文献   
94.
当前网络优化工作越来越从KPI指标优化向用户感知优化转变,但是在日常的优化工作中,如何将用户感知与常规的无线环境优化相关联,并通过优化无线环境实现用户感知的提升,仍然是困扰优化人员的难题。对海量实测数据进行覆盖、干扰与数据速率的关联分析,特别关注覆盖、干扰与影响用户体验的下限速率的关系,得到无线环境与数据速率这一重要的内在关联关系,从而确定保证不同业务速率要求的无线环境需求,为网络规划和优化工作提供参考。  相似文献   
95.
调制传递函数(MTF)是评价CCD相机成像系统质量的重要参数,它能真实地反映相机拍摄时的空间频率与图像对比度的关系。CCD相机的MTF测试中最关键的是靶标的选择,它决定了整个系统的测量精度和操作过程的复杂程度。理想的靶标函数是正弦函数,但制作光出射度随正弦波规律变化的分辨率板是非常困难的,因此利用明暗相间、相互平行的黑白条纹分辨率板来代替正弦波分辨率板,提出了测量MTF的方法。重点对CCD相机在奈奎斯特频率处的MTF测试结果进行了分析与评价。  相似文献   
96.
Transition metal oxides are capable of a wide range of work functions. This quality allows them to be used in many applications that involve charge transfer with adsorbed molecules, for example as heterogeneous catalysts, as charge‐injection layers in organic electronics, and as electrodes in fuel cells. Chemical and structural factors can alter transition‐metal oxide work functions, often making their work functions difficult to control. Little is known about the effects of the cation oxidation state and point defects on the oxide work function. It is necessary to understand how such chemical and structural factors affect work functions in order to controllably tune transition metal oxides for desired applications. Here, a correlation between the oxide work function and cation oxidation state is demonstrated. This correlation is attributed to the change in cation electronegativity with oxidation state. A model is presented that relates the work function to the oxygen deficiency for d0 oxides in the limit of dilute oxygen vacancies. It is proposed that the rapid initial decrease in work function, observed for d0 oxides, is caused by an increase in the density of donor‐like defect states. It is also shown that oxides tend to have decreased work functions near a metal/metal‐oxide interface as a consequence of the relationship between defects and work function. These insights provide guidelines for tuning transition metal oxide work functions.  相似文献   
97.
结合射弹发射药温度测量的实际需求,设计了超低功耗射弹药温计,给出了系统结构框图和软件流程,介绍了数字温度传感器TMP100和8引脚微控器PIC12F629,给出PIC12F629对TMP100的控制和数据读取过程,并介绍了系统的硬软件超低功耗设计.  相似文献   
98.
Memory cost is responsible for a large amount of the chip and/or board area of customized video and image processing system realizations. In this paper, we present a novel technique-founded on data-flow analysis which allows one to address the problem of background memory size evaluation for a given nonprocedural algorithm specification, operating on multidimensional signals with affine indexes. Most of the target applications are characterized by a huge number of signals, so a new polyhedral data-flow model operating on groups of scalar signals is proposed. These groups are obtained by a novel analytical partitioning technique, allowing to select a desired granularity, depending on the application complexity. The method incorporates a way to tradeoff memory size with computational and controller complexity  相似文献   
99.
Chen  Zhili  Che  Ruihong  Zhong  Hong  Tian  Miaomiao  Cui  Jie 《Wireless Networks》2019,25(4):1763-1776

Recently, truthful spectrum auctions have been extensively studied to improve spectrum utilization. Furthermore, privacy preservation in truthful spectrum auctions has also been taken into account. However, existing work mainly focuses on privacy-preserving homogenous spectrum auctions, while the case of heterogeneous spectrum auctions is ignored. In this paper, we propose PATH, a privacy-preserving auction for single-sided heterogeneous spectrum allocations. Through organically combining three security techniques: homomorphic encryption, secret sharing and garbled circuit, PATH reveals nothing about buyers’ bids and identities beyond the auction outcome to any participant party. Specifically, PATH not only maintains the properties of truthfulness and spectrum reuse of the underlining auction mechanism TAMES, but also implements the first provably secure solution for single-sided heterogeneous spectrum auctions. Finally, experimental results demonstrate that PATH incurs only limited computation and communication overhead, and it is feasible for large-scale applications.

  相似文献   
100.
运用光刻胶为注模的多次互不干扰金属电镀技术实现了惯性微型电学开关的低温制造与封装.电镀技术的低温过程可使微型开关直接成形于预先制作好的含有电子信号处理电路的基底上,加上同样借助于低温金属电镀技术的基于整个硅晶片的倒装封装,直接形成环绕各个器件的密封腔体.这一技术最终将使得模块化生产成为现实.微型开关的高度和它的密封腔的高度可以分别控制.电子信号可以通过金属互连线进入密封腔体.为了便于设计,建立了一个既简单又相对准确的"弹簧-质量块"模型.以此设计的惯性开关,即使在未封装的常温、常压条件下,均可工作109次以上.本文对密封腔体的强度和密封性,以及金属互连线的可靠性,都作了详细的检测,各项指标均达到其各自的标准.  相似文献   
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