Digital Signal Processing with Interleaved ADC Systems

This paper addresses a problem associated with interleaved ADC systems from the digital signal processing algorithm design perspective. The output streams of an interleaved ADC system are inherently in parallel format. It would be nice if DSP algorithms can be designed to take advantage of the inherently parallel signal streams in the interleaved ADC system without the need of a high speed parallel-to-serial multiplexer. Frequency response of a parallel filter bank is derived. It is found that the overall frequency response is the average of each individual interpolated channel filter plus the aliasing components. The aliasing components come from the deviation of each individual channel from the average response.Results are applied to characterize the gain mismatch of ADC arrays. Sinusoidal response is also investigated. The results can be used to characterize the frequency response mismatch of ADC arrays.Yih-Chyun Jenq received the B.S.E. degree from National Taiwan University, Taipei, Taiwan in 1971, and the M.S.E., M.A., and Ph.D. degrees in Electrical Engineering from Princeton University, Princeton, NJ in 1974, 1975, and 1976, respectively. From 1976 to 1980, he was Assistant Professor of Electrical Engineering at the State University of New York at Stony Brook, Stony Brook, NY. From 1980 to 1984, he was a Member of Technical Staff at AT&T Bell Laboratories, Homdel, NJ. From 1984 to 1990, he was a Research Manager and Principal Engineer at Tektronix Laboratories, Beaverton, OR. In September 1990, he joined the Faculty of the Department of Electrical and Computer Engineering at Portland State University, Portland, OR where he is currently a Full Professor. From 1987 to 1989, Dr. Jenq served as Associate Editor of the IEEE Transactions on Circuits and Systems in charge of Digital Signal Processing. He was the recipient of the 1988 Andrew R. Chi Prize Paper Award of the IEEE Instrumentation and Measurement Society. He holds ten (10) U.S. patents. Dr. Jenq is a fellow of the IEEE.     

人字形波纹片空调冷凝器设计

应用换热模型计算空气流过人字形波纹片管束的换热及R134a在光滑管内的冷凝换热特征。通过样机试验,验证设计方法的可行性。通过研究说明,换热模型可以较好地应用于人字形翅片管式冷凝器的设计。     

黑云母向绿泥石转化过程中微观形态及光性特征

通过偏光显微镜和扫描电子显微镜对砂岩样品的观察，对比研究了黑云母及绿泥石的光学特征及微观形态特征，发现了黑云母向绿泥石蚀变转化过程中光学特征及微观形态特征的变化，有明显波状消光现象。认为通常所见黑云母的波状消光现象可能是由中成岩阶段的矿物交代作用引起的，即叶片状绿泥石交代片状黑云母所致。为砂岩成岩阶段及孔隙演化史划分提供了新的依据。     

A market based active/reactive dispatch including transformer taps and reactor and capacitor banks using Simulated Annealing

This paper describes an optimization model to be used by System Operators in order to validate the economic schedules obtained by Market Operators together with the injections from Bilateral Contracts. These studies will be performed off-line in the day before operation and the developed model is based on adjustment bids submitted by generators and loads and it is used by System Operators if that is necessary to enforce technical or security constraints. This model corresponds to an enhancement of an approach described in a previous paper and it now includes discrete components as transformer taps and reactor and capacitor banks. The resulting mixed integer formulation is solved using Simulated Annealing, a well known metaheuristic specially suited for combinatorial problems. Once the Simulated Annealing converges and the values of the discrete variables are fixed, the resulting non-linear continuous problem is solved using Sequential Linear Programming to get the final solution. The developed model corresponds to an AC version, it includes constraints related with the capability diagram of synchronous generators and variables allowing the computation of the active power required to balance active losses. Finally, the paper includes a Case Study based on the IEEE 118 bus system to illustrate the results that it is possible to obtain and their interest.     

气液界面剪切力对液膜流动稳定性的影响

沿倾斜壁面下降的薄液膜表面受气流剪切力的影响将产生波动,液膜表面的波动特性和力平衡关系决定液膜流动特性和稳定性。基于边界层理论和积分法建立的二维剪切液膜表面波线性稳定性方程,分析了不同情况下剪切力对液膜稳定性的影响。研究表明,正向剪切力为不稳定性因素,反向剪切力为稳定性因素;正向剪切力使临界波数、扰动增长率和波速增大,使临界雷诺数减小;反向剪切力则起相反的作用;与反向剪切力相比,正向剪切力对液膜稳定性的影响相对显著;长波的传播速度受剪切力的影响比短波更大。     

超宽带脉冲信号的一种频域采样和接收方法

对纳秒级的超宽带脉冲信号进行采样需要设计采样速率高达数十GHz,且必须具有较低功耗的超高速模数变换器,提出了一种频域模数变换的方法,使超宽带脉冲信号通过一个频域滤波器组,并采用一组低速模数变换器在频域对脉冲信号并行采样,大大地降低了接收机对前端模数变换器采样速率的要求。并给出了频域同步、频域信道估计和频域解调的设计算法,计算机仿真结果证明了在能够大大降低采样速率的情况下,频域采样超宽带脉冲通信接收机具有和传统时域高速采样接收机相近的误码率性能。     

配网并联电容器的优化分组问题研究

对并联电容器的投资和补偿效果这一矛盾进行分析,建立起使电容器设备投资与因 无功缺额造成的有功网损费用最小的优化模型,并与实际的典型日负荷曲线相配合,求解优化的 电容器分组问题。简单的计算表明,电容器的优化分组可以达到比传统电容器分组方式更好的补 偿效果。     

高效数字信道化IFM接收机的研究

采用一种具有普遍性的推导方法得到基于DFT多相滤波器组的宽带数字信道化接收机高效结构,并且将瞬时测频技术应用于该结构中,提出了一种数字信道化瞬时测频接收机方案。计算机仿真表明:该方案提高了信道化接收机的频率分辨率,能够分辨同时落入一个信道的两个信号,而且运算复杂度低,硬件实现效率高,是能适应现代电子战中密集的信号环境的一种高效侦察接收机方案。     

用滤波器组实现IF的提取;Hardy小波和快速算法

本文提出了一种新的基于滤波器组和复解析小波(Hardy小波)级数展开信号从而提取信号瞬时频率的方法.该方法较传统的Hilbert变换求解析信号的方法比较对更多种类的噪声不敏感,同时较基于连续复解析小波变换的提取瞬频方法有更小的计算量,该方法保留了塔式算法的结构.     

翅片管式蒸发器结霜性能的仿真与实验研究

建立了结霜条件下翅片管蒸发器空气侧流动和换热的分布参数仿真模型,模型考虑了蒸发器结构、霜层厚度以及湿空气状态等参数在气流方向的沿程变化.对冰箱冷冻室蒸发器结霜条件下的动态性能进行了试验研究和数值模拟.结果表明,蒸发器结霜过程中的结霜量、能量传递系数和空气侧压降的计算值和试验值吻合良好,证明模型可以应用于翅片管蒸发器结霜性能的正确预测和优化设计分析.