Cloud Dynamic Scheduling for Multimedia Data Encryption Using Tabu Search Algorithm

The cloud computing is interlinked with recent and out-dated technology. The cloud data storage industry is earning billion and millions of money through this technology. The cloud remote server storage is on-demand technology. The cloud users are expecting higher quality in minimal cost. The quality of service is playing a vital role in any latest technology. The cloud user always depends on thirty party service providers. This service provider is facing higher competition. The customer is choosing a service based on two parameters one is security and another one is cost. The reason behind this is all our personal data is stored on some third party server. The customer is expecting higher security level. The service provider is choosing many techniques for data security, best one is encryption mechanism. This encryption method is having many algorithms. Then again one problem is raised, that is which algorithm is best for encryption. The prediction of algorithm is one of major task. Each and every algorithm is having unique advantage. The algorithm performance is varying depends on file type. The proposed method of this article is to solve this encryption algorithm selection problem by using tabu search concept. The proposed method is to ensure best encryption method to reducing the average encode and decode time in multimedia data. The local search scheduling concept is to schedule the encryption algorithm and store that data in local memory table. The quality of service is improved by using proposed scheduling technique.

     

A distributed fixed-step power control algorithm with quantizationand active link quality protection

A distributed fixed-step power control algorithm is presented. It is a simple feedback adjustment algorithm using only local information. In the ideal case where there is no power constraint, it is guaranteed that existing users will not be dropped due to admission of new users. If it is infeasible to accommodate all of them, the new user will be blocked. When the constraint on the maximum power is imposed, it is shown by simulation that blocking a new call is more probable than dropping any existing calls, if the capacity is exceeded. Besides, its convergence property is demonstrated. The convergence rate, which depends on the step size, is studied through simulation. In addition, the issue of power quantization is addressed     

Piezoelectric Transducer-Controlled Dual-Mode Switchable Bandpass Filter

A piezoelectric transducer-controlled dual-mode switchable bandpass filter is introduced. A piezoelectric transducer is used to lift up or pull down the attached dielectric substrate perturbation. When the dielectric substrate is pulled down, the perturbation excites dual modes and the dual-mode filter is on. The return loss is better than 10 dB and the insertion loss is less than 3 dB from 2.92 to 3 GHz. When the dielectric substrate is lifted up, the dual-mode resonator is unperturbed and the dual-mode filter is off. The isolation is 21 dB at 3 GHz. The on-off ratio is 18 dB     

Ka频段上变频模块设计

论述一种Ka频段上变频模块设计,对模块的杂散和相位噪声性能做了分析,根据分析结果,设计出合理的变频方案。滤波器采用Ansoft Designer和HFSS软件协同仿真,薄膜工艺制作,获得足够的杂散抑制度从而实现低杂散。应用取样锁相技术合成了相位噪声极低的27 GHz本振。对波导—微带过渡结构进行仿真,并给出仿真结果。从测试结果表明,模块设计实现了低杂散和低相位噪声。     

EMD分解区域的数据研究

本文介绍了一种新的非线性、非平稳信号的处理方法—HHT方法,并运用此方法对地震波进行了理论分析,详细研究了其中的EMD方法及其实现过程;通过大量的数据分析,总结了这一方法的优越性,指出其具有良好筛分及不可良好筛分的适用数值范围,并总结了其中蕴涵的规律。当组合简谐波的频率固定,A2/A1很小,超过某一限值时;或者A2/A1很大,超过某一限值时,数据值不能用EMD方法进行筛分。当组合简谐波的幅值比A2/A1固定不变,而频率变化时,当f2/f1很小时,如超过某一限值;或者f2很接近f1,f2/f1超过某一限值时,数据y值不能用EMD方法进行筛分。      

便携式智能油气检测仪设计

为了防备油气浓度超标造成的安全事故,研制了便携式智能油气检测仪。采用接触燃烧式气敏传感器进行油气检测,并增加补偿元件。用电桥电路作为测量电路,用双端输入方式连接电桥与运算放大器,对所采集的信号作放大、补偿处理。采用集成电路A/D芯片进行信号A/D转换,并在LCD数字显示屏上显示油气浓度值。设计报警电路,用C＋＋语言设计软件,采用单片机进行系统控制。气敏元件的误差补偿和数字化浓度检测有创新。该检测仪适用于石油、天燃汽等储运和使用场所。     

激光冲击抗金属疲劳断裂的激光参数优化试验研究

描述了激光冲击参数对２０２４－Ｔ６２铝合金疲劳寿命的影响．当激光脉宽为５０ｎｓ时．试件表面产生有害的热损伤，疲劳寿命无显著性差别．当激光脉宽为１３ｎｓ时．试件表面未产生足够的塑性变形，疲劳寿命提高幅度不大．当激光脉宽为３０ｎｓ时，试件表面形成微凹致密的光亮冲击区．疲劳寿命获得大幅度提高，在９５％的置信度下．激光冲击试件的中值疲劳寿命是来冲击试件的４．２～８．１倍．     

双生物识别图象的光学加密方法研究

本文提出了一种将两幅生物识别图象通过一套光学系统进行同时加密的方法。该方法先将一幅图象转换为纯相位和进行纯相位编码,再对另一幅图象编码,然后经过4f光学系统作频率域纯相位编码,并利用与编码过程类似的方法进行解码。可以证明该方法的编码图象为恒定的白噪声。解码过程具有鲁棒性,相位部分图象加密的安全性要高于振幅部分图象的加密。并分析了加性高斯噪声对解码图象的影响     

积分求解闪光灯电阻功率

工业闪光灯大量应用于智能交通工程,直接由交流220V供电,为达到宽场景、高亮度,需要使用较大电解电容,充电过程中限流电阻消耗功率较大,合适的电阻功率选取对于闪光灯可靠性和寿命有着决定性影响。由于输入信号是正弦波,半波充电过程非恒流或恒压,电阻功率计算比较复杂。通过积分方法,求得了闪光灯充电限流电阻的最大功率和最大电流,并得到了实物测量验证,产品可靠性得到了很好保证。     

碳基吸收体被动锁模大功率皮秒激光器

采用垂直蒸发法分别在玻璃和石英衬底上淀积单壁碳纳米管和氧化石墨烯材料来制作碳基可饱和吸收体。利用单壁碳纳米管作为饱和吸收体,实现了Nd:YVO4激光器被动锁模,最高输出功率为3.6 W,斜率效率为31%,脉冲宽度为7.6ps,重复频率为75MHz。利用氧化石墨烯作为可饱和吸收体,实现了Nd:GdVO4激光器被动锁模,最大输出功率为1.1W,斜率效率为11.3%,脉冲宽度为4.5ps,重复频率为70MHz。     

A quantitative analysis of SNR in the short-time Fourier transformdomain for multicomponent signals

A quantitative analysis is given for the signal-to-noise ratio (SNR) in the short-time Fourier transform domain for multicomponent signals in additive white noise. It is shown that the SNR is increased on the order of O(N/K), where K is the number of components of a signal, N/T is the sampling rate, and T is the window size. The SNR increase rate is optimal for given K. For this result, the SNR definition is generalized, which is suitable for signals not only in the time domain but also in other domains. This theory is illustrated by one numerical example     

基于MEMS开关的ET OFDM高效率PA设计

本文研究了基于MEMS开关的ET结构OFDM功率放大器,采用预失真功率放大器的结构可提高功率放大器效率。分析OFDM的发射标准,利用低损耗,高隔离度的MEMS开关来实现ET结构电压选择。利用GaN HEMT（Heterostructure Field—Effect Transistors）RF3821晶体管建立了基于MEMS开关的ET结构的PA模型,进行了实际电路设计,并利用了ADS软件进行仿真分析,输入1W的OFDM信号时,漏极效率为52％,EVM约为2．94％,输出功率为50W,增益为13dB．该功率放大器完全可以应用于OFDM系统中。     

Low-voltage low-power CMOS RF low noise amplifier

In this paper, a 1 V, 2 GHz CMOS low-noise amplifier (LNA) was developed intended for use in the front-end receiver. The circuit is simulated in standard $0.25\mathrm{\mu }\mathrm{m}$ CMOS MOSIS. The LNA gain is 25.675 dB, noise figure (NF) is 4 dB, reverse isolation $(S_{12})$ is $-134.3\mathrm{dB}$, input return loss $(S_{11})$ is $-14.6\mathrm{dB}$, output return loss $(S_{22})$ is $-13.34\mathrm{dB}$, and the power consumption is 5.13 mA from a single 1 V power supply. One of the features of the proposed design is using a three-component cascode limitation, one of it is a transistor, to reduce the supply voltage.     

准恒频电流滞环控制的死区补偿

详细分析了逆变器的死区效应,结合变环宽准恒频滞环控制的特点,本文采用按电流极性对脉冲给予补偿的方法,并对环宽进行修正。另外针对零电流箝位现象和滞环控制本身造成的过零点附近电流极性难以检测的问题,采用零电流附近极性给定策略;针对峰值处占空比为1的情况,通过对环宽进行限幅,减小电压波形的畸变。仿真和实验验证了该方案的可行性...