Musically Modified Substitution-Box for Clinical Signals Ciphering in Wireless Telecare Medical Communicating Systems

Telecare medical communication system (TMCS) is an essential component in today’s fast moving era. Patients are privileged to have wireless online medical facilities from their remote locations. Probability of noscomial infections is absolutely zero in such wireless TMCS. Data Security of heterogeneous patients during the wireless communication is a big challenge. Patients’ data privacy is highly confidential and need enhanced encryption measures. Intruding leads to the medical data adulterations in such telecare systems. This paper proposes a modified Advanced Encryption Standards (AES) based on the biometric generated key. Binary biometric key were generated from the patients’ fingerprints. S-box of AES has been enhanced by the musical involvement of metaheuristic harmony search algorithm. Clinical electrocardiogram (ECG) signals were carried out to enhance the security mechanism of the TMCS. Different tests were carried on the proposed technique, which in turn gets wise bench-mark outcomes. Statistical analyses were conducted to counterfeit the intruding. This proposed technique is suitable for wireless TCMS with higher degree of patients’ privacy.

     

大器成于变化之际

信息安全这棵绿树在经过了10余年的发展之后,今天不仅绿荫苒苒,而且摘取收获的果实也变得唾手可得。在国家信息化专家咨询委员会不久前主办的“首届国家信息化理论与实践研究高层论坛暨全国信息     

Shaping the digital switch

A procedure is given for shaping 1×2 digital switches on x- or y-cut LiNbO₃/LiTaO₃ for prescribed values of crosstalk in order to reduce the voltage-length product. The method is based on a normal mode analysis using ordinary coupled mode theory parameters and a known solution for shaped branches. A factor of three improvement in voltage-length product is obtained, compared to linear branches     

手机购物露端倪

中国目前约有手机用户4．16亿，约为互联网用户的四倍。面对这样一个庞大的消费市场，一直以互联网用户为目标开展电子商务的亚马逊心动不已。如今，北京消费者若想在亚马逊的全资子公司卓越网上购物，已经不必非得打开电脑、进入网页，在网上完成订单了……[编者按]     

Shaping using variable-size regions

Constellation shaping is extended to provide shaping gains without resorting to high-dimensional constellations. This is accomplished by dividing the constellation into unequally sized constellations, and selecting these constellations on an equiprobable basis. A design example is provided, demonstrating the simplicity and power of the approach     

Pulse Shaping for Differential Offset-QPSK

Pulse shaping is examined as a means to improve the performance of a differential offset quadrature phase-shift keying system in a bandwidth-constrained environment. Through optimization with respect to a composite Nyquist criterion, the derived pulse shapes have comparable performance to a$pi/4$-differential quadrature phase-shift keying in an additive white Gaussian noise (AWGN) channel and better performance in a hard-limited AWGN channel.     

现场直播塑造新闻报道新亮点

现场直播是电视新闻报道的一件"利器",现场直播的最大特点就是将现场的声画同步播出,时效性、现场感强,观众的参与感强。唐山广播电视台直播档节目由最初的电话连线,发展到SNG(卫星新闻采集)直播、移动流媒体的3G直播,突破了时间、地域的限制,方便、快捷,保证现场的情况实时准确地传输到直播间。从技术和内容建设等层面探讨如何做好电视新闻直播。     

超短脉冲的光谱整形

针对激光放大过程中的增益窄化效应 ,采用了窄带干涉滤光片与石英双折射滤光片两种器件对中心波长10 5 3nm ,谱宽 13nm的超短脉冲进行光谱整形。石英晶片的参数由计算机仿真确定。光谱整形的实验结果与数值模拟的结果吻合较好。整形后的光谱形状变为平顶 ,谱宽增加了 2nm。     

Traffic Shaping for Resource-Efficient In-Vehicle Communication

In-vehicle communication has become complex and costly due to the growing number of automotive network systems applied for different data types. In this work, our previously proposed in-vehicle network architecture that is based on Internet Protocol (IP) and full-duplex switched Ethernet (IP/Ethernet) is further investigated for real-time audio and video streaming. Quality-of-service (QoS) and resource usage are analyzed for selected IP/Ethernet-based network topologies. Traffic shaping is used to reduce the required network resources and consequently the cost. A novel traffic shaping algorithm is presented that outperforms other traffic shapers in terms of resource usage when applied to variable bit rate video sources in the proposed double star topology. In addition, a new architecture design is introduced for traffic shaper implementation in switches which operates on a per stream basis. Analytical and simulation results confirm that the proposed network architecture with traffic shaping is well-adapted for in-vehicle communication.      

光束整形技术展现出应用于激光加工业的潜力

透镜阵列光束整形技术在激光材料加工市场崭露头角.LIMO公司的Vitalij Lissotschenko和Paul Harten介绍了半导体激光器直接应用于激光焊接和激光切割领域的状况. 大功率激光光源现已广泛应用于多种材料的加工领域.目前最普遍的应用包括:焊接、钎焊、切割、钻孔、激光退火、微机械、烧蚀以及微光刻等.对于激光材料加工而言,除了选择合适的激光光源外,选取能够产生适当光场剖面的高效能光学元件也至关重要.     

∑—△调制噪声整形的研究

介绍∑－△调制器的基本结构，分析∑－△调制技术对噪声进行整形的基本原理及过采样率、∑－△调制器的级数对整形效果的影响，从中获得了一些有用的结论。     

瓦级半导体激光器光束整形装置

介绍了一种采用光束远场发散角分割的方法 ,利用已有专利的微片棱镜堆光束整形器 ,对瓦级半导体激光器光束整形 ,该装置由半导体激光器、微柱透镜、柱面透镜、微片棱镜堆、聚焦系统和光纤组成 ,该方法可在一定程度上改善整形效果 ,具有结构简单、加工和装配容易的优点     

太赫兹脉冲整形技术研究进展

太赫兹(THz)脉冲整形技术在量子理论、生物医学成像、安全检查、亚毫米波通信等领域都具有重要的学术价值和应用前景。概述了基于飞秒脉冲的整形技术和新型太赫兹辐射材料整形技术,分析了太赫兹脉冲整形器件整形技术目前的研究状况,并对各种整形方法的发展进行了展望。     

改进型统计幅度成形在OFDM中的设计

统计幅度成形(PAS)可使加性高斯白噪声(AWGN)信道以低于香农信道容量的任意速率进行传输。文章讨论了改进型的统计幅度成形,将统计幅度成形与正交频分复用(OFDM)相结合用于频率选择性衰落信道中。相比直接在每个OFDM子信道中使用统计幅度成形,改进型统计幅度成形只使用一个概率分布匹配器(CCDM)来产生成形比特。改进型统计幅度成形缩小了成形间隔,并实现了传输速率的匹配。从仿真结果可以看出,在误码率低于10-3的情况下,相同的误码率改进型成形分布的传输速率比均匀分布的传输速率高0.07 bit/s/Hz,只低于香农限0.24 bit/s/Hz,即证明改进型统计幅度成形比均匀分布能以更高的传输速率可靠的传输数据。     

一种新的UWB脉冲成形方案

本文基于美国联邦通讯委员会FCC对UWB信号的发射功率谱强制规定,提出了一种新的UWB脉冲成形方法-Gaussian-sinc函数波形脉冲.该方法通过方便灵活的参数调整,可以产生完全符合FCC频谱模板要求的极窄脉冲波形.仿真结果表明,该方法产生的UWB系统发射脉冲旁瓣小,频谱利用率高,不需降低整个频段的信号发射功率,就能有效解决共存通信环境下的同频干扰问题.     

带内噪声整形连续时间滤波器

提出了一种带内噪声整形连续时间滤波器,详细分析了滤波器的传输特性和噪声整形原理.采用0.18 μm CMOS工艺,设计了一个4阶巴特沃斯型全差分低通滤波器.仿真结果表明,滤波器的带内增益为10 dB, -3 dB频率为4.5 MHz;输出噪声的理论分析与仿真结果一致;在2.5 V电源电压下,消耗电流为0.8 mA, 带外IIP3为25.3 dBV,带外无杂散动态范围为65.3 dB.     

一种改进的自适应波束赋形算法

为了弥补传统的LMS算法采用固定步长无法解决收敛速度和稳态误差之间矛盾的缺陷,改进了失调系数,提出了一种改进的LMS算法用于求解自适应波束赋形的最佳权值。理论分析证实归一化的LMS算法可以通过采用一个可变因子使瞬时输出误差最小化。仿真结果表明,归一化的LMS算法采用了可变步长比传统LMS算法收敛快,稳态误差和失调相对于LMS都有所改善。     

Quadrature Mismatch Shaping for Digital-to-Analog Converters

Quadrature sigma-delta analog-to-digital converters require a feedback path for both the I and the Q parts of the complex feedback signal. If two separate multibit feedback digital-to-analog converters (DACs) are used, mismatch among the unit DAC elements leads to additional mismatch noise in the output spectrum as well as an I/Q imbalance. This paper proposes new quadrature bandpass (QBP) mismatch shaping techniques. In our approach, the I and Q DACs are merged into one complex DAC, which leads to near-perfect I/Q balance. To select the unit DAC elements of the complex multibit DAC, the well-known butterfly shuffler and tree structure are generalized towards a complex structure, and necessary constraints for their correct functioning are derived. Next, a very efficient first-order QBP shaper implementation is proposed. Finally, the newly presented complex structures are simulated to prove their effectiveness and are compared with each other with respect to performance     

Shaping codes constructed from cost-constrained graphs

We give a general procedure for constructing shaping codes from costly constrained graphs. The codes have finite-state encoders and sliding-block decoders. The shaping codes are in the spirit of Calderbank and Ozarow (1990), where shaping is achieved by nonequiprobable signaling on T subconstellations of a signal constellation Ω. We show how nonequiprobable signaling relates to a costly constrained channel. Khayrallah and Neuhoff developed a procedure for constructing codes with rates close to the capacity-cost function of the general cost-constrained channel, and we use their procedure to construct asynchronous (variable-length to fixed-length) shaping codes. Comparisons are made with shaping codes having comparable gain. The codes presented here are less complex and have lower peak-to-average power and lower constellation expansion ratio