双向自愈环基站视频监控系统的开发应用

本文结合当前江苏移动偏远基站的维护力量分散、远程技术支援体系差、安全防范能力低的实际情况,以基站对实时视频监控的要求为基础,从网络现有资源配置出发,充分挖掘基站远程技术支援手段,提高基站安全防范监控能力的基础上,提出开发基站双向自愈环网视频监控系统的设想,并对该套系统在基站内的应用前景进行了分析探讨。     

Sb掺杂SnO2修饰双电层电容活性炭电极的研究

应用sol-gel浸渍与热处理工艺相结合,在活性炭表面包覆Sb掺杂的SnO2薄膜对电极进行修饰,构成AC-SnO2/KOH/AC-SnO2双电层电容器,测试结果表明,400 mA/g电流密度条件下,修饰后的双电层电容器在0.001～1.5 V相对较高电压区间的放电容量,比AC/KOH/AC双电层电容器在0.001～1.0 V电压区间高36%,但AC-SnO2的单电极比电容仅为AC单电极比电容的91.9%;当电流密度大于400 mA/g,两种电极的大电流性能相当。     

应用共聚焦显微镜观察卵母细胞成熟过程中Cdc42活性变化

Cdc42属于GTP酶家族成员,参与细胞骨架调节和细胞发育,但在细胞分裂过程中的作用所知甚少.以爪蟾卵母细胞为模型,GFP-wGBD(Cdc42活性探针)和罗丹明-微管蛋白作为荧光标记物,采用共聚焦显微镜观察卵母细胞分裂过程中Cdc42活性变化.结果显示卵母细胞中,极体释放数分钟前,纺锤体上方和周边可见微弱的Cdc42活性,2 min～4 min内,活性逐渐增强,随后收缩环形成,胞质分裂发生.胞质分裂完成后,Cdc42活性消失.结果提示Cdc42活性可能与爪蟾卵母细胞胞质分裂有关.     

A modified aperture-synthesis method for super-resolution by a single digital hologram

A modified aperture-synthesis method is reported to improve the resolution of a reconstructed image in digital holography by a single hologram. A series of sub-holograms incoherently overlapped on a CCD are recorded as a single aperture-synthesized digital hologram. The angular division multiplexing is introduced to both the object and the reference path for holographic recording. The final super-resolved image is obtained by synthesizing the several reconstructed images. In the experiment, a two-dimensional transparent USAF resolution test target is used. The result demonstrates that the resolution of the reconstructed image is improved from 16.00 lp/mm to 22.64 lp/mm in the horizontal direction.     

New Signature Waveforms for Multi-rate QS-CDMA System with QPSK Modulation

This paper presents a multi-rate quasi-synchronous CDMA (QS-CDMA) system with QPSK modulation based on the new signature waveforms, namely GPZ-chip waveforms which are constructed by the generalized pairwise Z-complementary (GPZ) codes and optimal chip waveforms. According to the properties of GPZ-chip waveforms, the multiple access interference of different users can be reduced or eliminated. The interferences among different streams of the same user are handled by an optimal (or suboptimal) multi-stream detector(s). The performance of the proposed system is simulated and analyzed in a cellular communication environment consisting of multipath fading. The result shows that the proposed system has similar performance as compared to the single-rate QS-CDMA system employing GPZ codes with one chip waveform due to the properties of multi-stream detection. Also, the proposed system can achieve a significant interference reduction as compared to the multi-rate system employing concatenated WH/m sequence sets with one chip waveform due to the zero correlation zone properties of the GPZ-chip waveforms, thus resulting better BER performance.     

Bandwidth allocation and admission control scheme based on Nash bargaining solution for WiMAX systems

Development of fair and efficient bandwidth allocation and admission control schemes is one of the key issues in the design of IEEE 802.16 broadband wireless access systems in time division multiple access (TDMA) mode. In this article, the problem of bandwidth allocation and admission control is formulated as a Nash bargaining model. The nash bargaining solution (NBS) derived from the cooperative game is adopted to maximize the spectrum utilization. Analysis and simulation results show that there is a unique Pareto optimal bandwidth allocation solution by using NBS among various flows. Furthermore, maximum utility of the system can also be maintained by using the admission control policy with different number of connections and variable channel qualities. The total throughput of the proposed scheme is close to the maximal one, while significantly improving fairness compared to the existing solutions.     

低功耗内容寻址存储器的设计

分析了传统内容寻址存储器(CAM)结构,提出其功耗模型。根据功耗模型,设计了一种适用于以太网MAC地址识别的新型低功耗CAM单元结构及其预充电路。基于SMIC 0.18μm/1.8V工艺库,利用HSPICE平台对电路进行仿真,仿真频率为100MHz。结果表明,64×64的新型CAM阵列平均查找时间为0.8955ns,写入功耗和查找功耗分别为22.61μW/b和4.186μW/b,仅为传统CAM结构的12.58%和37.9%。     

基于QCM的水果中金属离子检测方法研究

以压电石英晶体的波动方程作为理论基础,首先推导了气相条件下石英晶体微天平(QCM)传感器的相位 质量关系式。然后以猕猴桃中Cu2+检测为例,分别测量出QCM传感器对应的频率偏移量及相位偏移量,应用Sauerbrey方程和新推导的相位——质量方程,计算出猕猴桃中Cu2+的含量;最后,将这两种方法的实验结果进行分析比较并进行了相关讨论。结果表明,基于压电QCM相位检测原理的金属离子检测也是一种有效的金属离子检测方法。     

关于可视电话的专利分析

随着芯片技术、传输技术、数字通信、视频编码技术和集成电路技术不断发展并日趋成熟,适合商用和民用的可视电话浮出水面,走上人们的视野.在中国,关于可视电话的专利申请从20世纪90年代初开始出现,到21世纪开始数量上升较快,很明显,各大企业和机构已经纷纷展开了对该技术的专利部署.从可视电话技术的发展现状、专利申请年度分布情况、专利申请的IPC分布、申请人排名、专利申请区域分布等,进行了多视角的专利分析.     

Rate adaptive resource allocation in orthogonal frequency division multiple access system using multi‐objective immune algorithm

Rate adaptive downlink resource allocation in orthogonal frequency division multiple access system is a constraint optimization problem, which is to maximize the minimum data rate of the user subject to constraint that total power cannot exceed a given value. How to handle the constraint is a key issue for constrained optimization problem. Different with the available schemes on constraint handling, the proposed algorithm converts the constraint into an objective. Then, the resource allocation is combined into a multi‐objective optimization problem. An improved multi‐objective optimization algorithm based on artificial immune system is proposed to solve it. The simulation results show that, compared with previous schemes, the proposed algorithm performs remarkable improvement in sum capacity. Copyright © 2013 John Wiley & Sons, Ltd.