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.

     

Analysis of the impedance of a coaxial, large-bore copper-vaporlaser

The impedance of the laser head of a 100-W copper-vapor laser is investigated. The laser head is of a coaxial geometry, which is commonly used for longitudinally electrically excited, pulsed-gas lasers. The plasma conductivity is estimated using the available data on plasma parameters. The effect of radial gradient of the gas temperature and electron density is considered. The tube inductance and capacitance are estimated and the combined effect is demonstrated. The skin effect is considered. A method to calculate the exact influence of the skin effect on the tube impedance is presented. The full calculation procedure is demonstrated for the case of a 100-W, 8-cm-diameter, copper-vapor laser. The consequent impedance is used to calculate the laser current under given excitation conditions. Very good agreement exists between the calculated and measured laser current. The metal-sleeve diameter is found that is optimal for power matching     

Temperature control for food in pots on cooking hobs

A control system for the temperature of food in a cooking pot is introduced. The cooking pot is heated on a consumer cooking hob. The temperature of the pot side is used as input for the controller. It is measured by an infrared detector. The infrared detector is a thermopile. The sensor signal is evaluated by a rule-based control algorithm. The system is simple, reliable, and very user friendly. An exact temperature settlement in a consumer hob is available for the first time. The system is used for automatic cooking     

Effect of copper slurry on polishing characteristics

The composition of the polishing solution is optimized by investigating the impact of the WIWNU (the so-called within-wafer-non-uniformity WIWNU) and the removal rate(RR) on the polishing characteristics of copper.The oxidizer concentration is 1 Vol%;the abrasive concentration is 0.8 Vol%;the chelating agent of the solution is 2 Vol%.The working pressure is 1 kPa.The defect on the surface is degraded and the surface is clean after polishing.The removal rate is 289 nm/min and the WIWNU is 0.065.The surface roughness measured by AFM after CMP(chemical mechanical planarization) is 0.22 nm.     

CAN总线接口扩展设计与驱动开发

介绍了一种基于S3C6410的CAN总线接口扩展方案,通过SPI接口对CAN接口进行扩展,并给出具体的硬件电路。重点研究了WINCE系统下独立CAN控制器MCP2515的驱动程序。结合CAN总线技术规范和MCP2515的特点设计了相关的软件代码,编写了CAN流接口驱动程序,实验结果表明,在WINCE系统下能够较好实现CAN总线的通信。     

铜抛光液对片内非均匀性影响的研究

对于低介电常数材料和铜互连结构在低压化学机械抛光中,研发新的抛光液和调整工艺参数是非常必要的。抛光液的研发是减少抛光表面划伤和解决磨料剩余的关键。抛光液组成由片内非均匀性和铜抛光去除速率特性来优化。氧化剂浓度1Vol%;磨料浓度0.8Vol%;螯合剂浓度2Vol%。工作压力1kPa。抛光后表面缺陷减小并且表面干净无污染。去除速率289nm/min,片内非均匀性0.065。化学机械抛光后用原子力测量粗糙度为0.22 nm。     

混合模式AGC设计

该文提出了一种混合模式AGC,在不需要A/D转换器的条件下可以获得较好的线性,同时采用粗调与细调相结合的方法大大地降低了系统的稳定时间。该设计基于1st Silicon 0.25m 标准CMOS工艺,仿真表明,当输入信号幅度在100mV到1.3V范围内变化时,输出信号的幅度为800mV25mV,系统的稳定时间小于3.2s;当输入信号幅度为1V时,输出信号的THD低于－45dB;AGC的最大功耗为10mW。     

一种基于SRD和NLTL的皮秒级脉冲产生电路

提出了一种利用SRD产生窄脉冲信号的方法,对其产生窄脉冲的机理进行了分析和仿真,为了使得脉冲宽度变得更窄,电路采用了NLTL结构,拓展了SRD产生窄脉冲的应用,文中分析了NLTL的工作原理。设计了基于SRD和NLTL的皮秒级脉冲产生电路,给出了测试结果,脉冲宽度为110 ps,幅度为3 V。     

108 GHz 功率放大器模块研制

介绍了105～108 GHz 频段功率放大器模块的设计和制作。模块由波导微带转换、功率芯片及芯片偏置电路组成。讨论了放大模块的设计及加工测试过程,并对模块中的关键技术波导-微带转换进行详细阐述。波导-微带转换采用E面微带探针激励完成。通过理论分析及仿真优化后设计出转换模型并制作出实物进行测试。单个转换在100～110GHz 频段内插入损耗小于0.6 dB,回波小于-10 dB。测试结果表明设计的波导-微带转换具有插入损耗小,工作频段宽的优点。采用此转换制作的功率放大模块在105～108GHz频段上增益大于13dB,输出功率大于200mW,达到预期设计指标。     

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。     

一种新型弹载偶极子天线分析与设计

给出了一种新型结构的弹载偶极子天线,采用基于自补结构的蛇形振子作为辐射器,并用矩量法对振子结构进行优化,采用简化形式的锥形BALUN以实现平衡馈电。测试结果表面该天线具有良好的E面全向特性和宽带特性。主要分析了该天线的辐射特性,最后给出并分析了实测数据。该天线具有结构紧凑、馈电简单、带宽较宽、易于制作等优点。     

轻便型钐镨钴永磁迴路

正 (一)引言 本文介绍3cm波段速调管上使用的均匀场聚焦钐镨钴(Sm Pr Co)永磁迴路。它的磁间隙长度Lg=67.3mm,间隙处均匀区最强场强Bmax=2700 Gs,均匀区的场强波动为4％。SmPrCo磁钢重5kg,磁系统总重量为8.6kg,用于峰值功率为50kw的速调管,获得了满意的结果。电子束通过率达9899％。(二)磁迴路的设计和结果 聚焦磁场决定于电子枪的光学系统、高频互作用区和进入     

基于89C2051单片机控制的数控直流电流源设计

数字化电源的发展,已经形成了一门综合性的学科。在现代化工农业生产、通信、电子仪器仪表、国防事业以及高新技术的装备中,高可靠性、高效率的电源,是不可缺少的设备之一。该设计采用89C2051单片机作为控制单元,利用X9241数字电位器、模/数转换器与恒流源电路部分构成数控可调的恒流电流源,系统中主要应用了数字电位器,它的输出电压作为恒流源部分的参考电压,该电压通过电压跟随器送入恒流源控制电路,从而实现恒流的输出。输出电流的给定由输入键盘来设定,89C2051通过I2C总线方式与X9241实现数据的传输。显示采用4位LED数码管,显示驱动采用软译码方式。     

半导体激光器驱动电路的光功率控制的研究

介绍了数字控制式半导体激光器驱动电路的设计，包括温度控制系统和光功率控制系统。该系统以单片机为核心，结合外围电路，以数字控制技术代替以往的模拟电路，易于控制，精度高。对光功率控制系统也以单片机为核心，配合外围的功率采样电路和电流驱动电路．同时使用PD控制算法，控制电源电流，从而控制激光器光功率输出。在PD参数整定时，采用了工程实验法多次实验调试确定参数。建立数学模型，从而实现软件控制。为了提高控制的精度，把功率范围分为9段，对每一段都整定了一组参数，从而将光功率误差控制在0．02W内。所设计的驱动电路精度高，实时性好，达到了设计要求。     

Analysis of spherical annular microstrip antennas

The spherical annular microstrip antenna is analyzed. The antenna is excited by a coaxial line. The general transmission line model (GTLM) is used to compute the input impedance. The radiating TM₁₂ mode is considered because of its wide band. The effect of the other radiating modes and the nonradiating modes on the TM₁₂ mode is investigated. The effect of different parameters on the input impedance is considered. The radiation patterns are computed using the method of moments     

不同形状连续激光辐照皮肤组织温度场数值模拟

本文基于生物组织热传导方程,分析了连续平顶型激光和连续高斯型激光辐照皮肤组织的热传递规律,建立了更为接近细胞尺寸的三层皮肤组织模型,采用有限元方法对两种不同形状激光作用于皮肤组织时产生的温升情况进行了数值模拟,仿真研究了不同作用时间、不同表面距离和不同深度的皮肤组织温度场分布。结果表明,相同条件下,由连续平顶型激光在组织内部产生的最高温度明显小于高斯型的,主要原因是平顶型激光能量分散,而高斯型能量相对集中。连续高斯型激光辐照组织后产生的温升区域面积和穿透深度均较大,撤去激光后达到初始温度的冷却时间也相应较长。     

基于FPGA的测角脉冲细分电路的设计

对传统的数字化转角测量方法进行了简要介绍,提出了一种能够提高测角分辨率的脉冲细分技术,并结合激光陀螺输出信号对该方法进行了误差分析。接着利用FPGA对此项技术进行了硬件实现,具体描述了电路各部分的工作原理及程序设计,并使用QuartusⅡ软件对电路进行了仿真。最后,对某型激光陀螺输出信号进行周期采样,对电路进行了实验验证。结果表明该技术能够有效提高转角测量分辨率,电路工作稳定,取得了预期的效果。     

某测试转台电控系统设计

给出了测试转台电控系统的组成,着重讨论了伺服控制单元的设计,详细介绍了伺服主控模块的设计和对外接口,分析计算了转台负载力矩,并由此给出了伺服电机的选型,简要介绍了系统的电源设计。最后研制出了测试转台样机,给出了测量误差,对类似工程设计具有一定的参考意义。     

用于白癜风治疗的308nm XeCl准分子激光系统

研制了一台用于白癜风治疗的308nm XeCl准分子激光系统。根据准分子激光器脉冲式放电的特点,设计了推挽式脉冲开关电源。实验研究了激光器脉冲重复频率、工作电压、气体寿命对激光输出能量的影响,并检测了激光输出脉冲能量的稳定性。通过自动反馈控制系统调整激光头放电工作电压实现输出激光能量的稳定。激光采用扩展型紫外液芯光纤传导,得到均匀性良好的治疗光斑,液芯光纤对308nm激光的传输效率约为70%。激光器脉冲重复频率1～200Hz,工作电压18～25kV,输出能量不稳定度小于4%。经光纤输出用于治疗的有效光斑直径22mm,脉冲能量密度2～3mJ/cm2。     

一种小型超宽带微带天线

给出了一种小型化超宽带微带天线,该天线采用微带线对半圆形和矩形组成的阶梯状辐射单元进行馈电,基板背面为相似形缺陷地结构窗口。天线参数采用电磁仿真软件CST进行仿真和优化。所设计的小型化超宽带微带天线相对带宽达144.9%(2.15～13.47GHz),带内回波损耗均在-10dB以下,整个工作频段内天线的增益平均在4dB以上,天线的辐射方向图形状在频带内基本保持不变。该天线具有结构紧凑和形状简单的特点,易于加工和集成。最终实际制作了天线样品,并进行了测试,实测数据与仿真结果吻合良好。实验结果表明该微带天线具有良好的小型化和超宽带特性。