带有USB接口的16位立体声数模转换器PCM2702

PCM2702是Burr-Brown公司新近推出的一种带有USB接口的16们立体声数模转换器芯片。文中简要分析了该芯片的性能特点和工作原理,最后给出了PCM2702的典型应用电路。     

Greedy randomized adaptive search procedure for analog test point selection

Analog test point selection (ATPS) is an important problem that arises in the area of analog system testing. This paper formulates the problem as a combinatorial problem and proposes a solution method based on greedy randomized adaptive search procedure (GRASP). The proposed method is an iterative procedure, with each iteration consisting of two phases. The first phase, a construction phase, produces a feasible solution. The second, a local search, seeks for improvement on construction solution. In addition to applying the basic GRASP, the algorithm introduces randomness into both phases including: randomizing the selection of greedy criteria and checking redundant test points in a random order. The former can prevent the algorithm from converging prematurely to local optima, while the latter make the algorithm probably get more than one best solution. The efficiency of the proposed method is proven by two practical analog circuits as well as statistical experiments. Results show that our algorithm, compared with other methods, finds the global minimum set of test points more accurately and more efficiently. Therefore, it is a good solution to optimize ATPS.     

极性小分子对Ni/TiO_2核壳结构电流变液性能的影响

通过力学性能试验、形貌观察,重点研究电流变液的核壳微粒Ni/TiO2用Urea等极性分子修饰对电流变液性能、形貌的影响。结果表明,极性小分子可大幅提高电流变液的性能,对Ni/TiO2/Urea微粒存在一个Urea/Ti临界值,其值的质量分数为30%。     

带约束的复FIR数字滤波器Chebyshev设计算法

本文主要讨论了复FIR数字滤波器的频域不等式约束Chebyshev设计问题.作者首先把文献[1]中的复交错点组定理扩展到有不等式约束的情况,之后根据扩展定理中对最优解特性的描述,并结合复Remez算法[1]及赖晓平的迭代Remez算法[2][3],提出了一种有效的算法来解决频域带不等式约束的复FIR数字滤波器的Chebyshev设计问题.如果问题的解存在,则算法能保证收敛到最优解.作者用MATLAB语言对上述算法进行了实现并做了仿真分析.     

EMBLAZE-VCON公司看好中国视频通信市场的未来发展

通过多年来信息技术和业务的不断发展，人们之间的交流方式变得多种多样，电信用户不再满足于电话形式的语音通信，而希望能够进行更多面对面地交流，所以视频通信近年来得到了迅速发展。以色列EMBLAZE—VCON公司成立十多年来一直致力于网络多媒体即时通信系统的开发、制造和销售，并提供视频通信整体解决方案。EMBLAZE—VCON公司总部设在以色列，目前已经在中国、美国、德国、法国、英国、西班牙等国家设有分公司。     

Privacy-Preserving and Energy-Efficient Continuous Data Aggregation Algorithm in Wireless Sensor Networks

Wireless Personal Communications - Privacy-preserving continuous data aggregation in wireless sensor networks has broad application prospects, such as environmental monitoring, health care, etc....     

Fully Secure Identity Based Key-Insulated Signcryption in the Standard Model

To achieve unforgeability and confidentiality simultaneously, signcryption has been introduced with better efficiency than the signature-then-encryption approach in terms of computational costs and communication overheads. Taking the key leakage into account, it is desirable to design identity-based key-insulated signcryption (ID-KI-SC) scheme to reduce the damage caused by the secret key leakage. In this paper, we have shown that all of the existing ID-KI-SC scheme can not offer either the unforgeability property or the indistinguishability property. Furthermore, an improved scheme along with the formal security proof in the standard model has been suggested in this paper. In view of computational cost and communication overhead, our scheme is amongst the most efficient IB-SC schemes secure in the standard model.     

皮秒拍瓦激光的参数测量系统可靠性分析

皮秒参数测量系统用于提供皮秒拍瓦激光系统的各项状态参数,协助激光系统达到预期的技术指标。针对皮秒拍瓦激光系统的技术指标,皮秒参数测量系统将提供压缩脉冲的能量、脉宽、远场、信噪比等参数。为了判断参数测量系统的工作性能,采用均方根(RMS)误差来描述测量系统的可靠性。经过实验测试,能量测量单元的测量范围为10～1000J,标定实验数据的RMS误差为2.2%。脉宽测量单元的时间测量范围为0.5～18.0ps,时间分辨率为0.07ps,测试数据的RMS误差为3%。远场测量单元的空间测量范围为150倍衍射极限(DL),空间分辨率为0.3倍DL,测试数据的RMS误差为0.15%。信噪比测量单元的时间测量范围为30ps,时间分辨率为0.3ps,动态范围为106。基于拍瓦实验提供的测试数据表明,皮秒参数测量系统能够稳定可靠地提供以上参数的实时测试数据,实现拍瓦装置的运行状态诊断功能。     

Modeling operation and microarchitecture concurrency for communication architectures with application to retargetable simulation

In multiprocessor-based system-on-chips (SOCs), optimizing the communication architecture is often as important as, if not more than, optimizing the computation architecture. While there are mature platforms and techniques for the modeling and evaluation of computation architectures, the same is not true for the communication architectures. A major challenge in modeling the communication architecture is managing the concurrency at multiple levels: at the operation level, multiple communication operations may be active at any time; at the microarchitecture level, several microarchitectural components may be operating in parallel. Further, it is important to be able to clearly specify how the operation-level concurrency maps to the microarchitectural-level concurrency. This paper presents a modeling methodology and a retargetable simulation framework which fill this gap. This framework seeks to facilitate the design space exploration of the communication subsystem through a rigorous modeling approach based on a formal concurrency model, the operation state machine (OSM). Our OSM-based modeling methodology enables the entire system including both the computation and communication architectures to be modeled in a single OSM framework. This allows us to develop a tool set that can synthesize cycle-accurate system simulators for multiprocessing-element SOC prototypes. We show that, by simulation, critical system information such as timing and communication patterns can be obtained and evaluated. Consequently, system-level design choices regarding the communication architecture can be made with high confidence in early stages of design.     

一种基于航海雷达对船舶分型的方法

文章提出了一种通过对航海雷达回波信号进行频域处理来对船舶进行分型的方法.通过离散傅里叶变换提取雷达回波中相对高频成分、相对低频成分和多普勒频率来对船舶进行外形凹凸程度的分型和船舶大小的分型.通过MATLAB仿真,证明此种方法能够达到预想效果.