The effects of time constraints on phonatory stability in normally speaking adult women

Forty normally speaking women sustained /a/ five times in two conditions,untimed and timed. In the untimed condition, phonation began whenever the subject felt ready. The timed task required subjects to begin phonation as quickly as possible after the examiner's signal. Conditions were counterbalanced across subjects. Jitter and shimmer values were obtained on a Kay Elemetrics Computerized Speech Lab (Pine Brook, NJ). Three distinct patterns of change emerged for fitter and shimmer from the untimed to the timed condition, reflecting either decreases, increases, or no change in values. These changes in jitter and shimmer values across conditions are related to a reaction time model of “bias toward accuracy.”     

Heartbeat-related fundamental frequency and amplitude variation in healthy young and elderly male voices

Modulation of the acoustic amplitude and fundamental frequency of a sustained vowel across the heart cycle was examined via signal-averaging. Ten normal young and ten normal elderly men prolonged phonations of the vowel /a/. Consistent with previous studies, the young men's maximal heart-beat-related frequency and amplitude variations averaged 1.0% and 8.4% of their respective means. Such modulation was estimated to account for 6.6% of the absolute jitter and 11.3% of the shimmer measured in these voice samples. The extent of this systematic variation was significantly greater in the older voices, averaging 2.4% of the mean frequency and 15.4% of the mean amplitude and was estimated to account for approximately 12.9% and 15.8% of their mean absolute jitter and shimmer, respectively. This age-related difference is thought to be a manifestation of involutional changes in laryngeal vascular and soft tissues and in ventilatory biomechanics.     

The dual-edge alignment technique with improved spur reduction effects in ring oscillators

In this paper, the technique of dual-edge phase-alignment and its effects on ring oscillators are presented. This technique provides resetting of the built-up jitter at both rising and falling edges of a clean aligning signal named as the reference. Using signals and systems theory, the effect of the technique on the spurs due to the aligning reference signal is completely analyzed. We show that adding properly the dual-edge aligning feature to phase-aligned ring oscillators cause the spurs in the neighborhood of the carrier to disappear. First, the validity of the results obtained from the derived analytical equations is verified through simulations using MATLAB. Then a complete circuit considering realistic models for its components is simulated in TSMC RF CMOS 0.18um process using ADS for further validation.     

激光触发多级多通道开关研究

 研究了200kV激光触发多级多通道开关的运行机理,该开关在直流电压下以四倍频Nd:YAG激光器为触发源进行的实验结果表明：开关触发延迟时间及其抖动随开关电压、激光能量和充气压力上升呈指数下降趋势,对混合气体则随气体密度上升而上升。随透镜焦距的增大延迟时间及其抖动呈上升趋势。该开关实现了多通道放电。     

一种数据时钟恢复电路的研究与设计

提出了一种支持双数据率的数据时钟恢复电路,对电路中的鉴相器、环路滤波器、压控振荡器等进行了详细的分析研究和设计.基于0.18μm CMOS工艺,在电源电压1.8V下对电路进行仿真.仿真结果显示,电路在2.7 Gb/s和1.62 Gb/s随机流下的抖动峰峰值分别为14 ps和12ps,功耗为80 mW.测试结果显示,时钟恢复电路在2.7 Gb/s和1.62 Gb/s随机流下的抖动峰峰值分别为38 ps和27 ps.     

基于抖动测试的AFDX端到端延迟紧性修正

AFDX引入虚拟链路(Virtual Link)实现物理带宽资源的逻辑分隔。由于数据帧的异步到达和多路复用输出造成虚拟链路的时延抖动现象,并最终导致流量端到端延迟分析的不确定性。本文提出了一种基于抖动测试值的网络演算紧缩方法。通过分布式测试,获得虚拟链路在网络中的实际传输抖动,并以此为基础,建立了流量传输精确化模型,通过流量模型的逐级修正,使端到端延迟计算结果逐级精确化。通过将抖动实际值与理论分析结果相结合,提供了网络演算悲观度及其扩散影响度量的直观对比,提高了延迟计算的紧性。