On using peak amplitude and rise time for AE source characterization

Acoustic Emission (AE) signals, which are electrical version of acoustic emissions, are usually analysed using a set of signal parameters. The major objective of signal analysis is to study the characteristics of the sources of emissions. Peak amplitude(P _a ) and rise time(R _t ) are two such parameters used for source characterization. In this paper, we theoretically investigate the efficiency ofP _a andR _t to classify and characterize AE sources by modelling the input stress pulse and transducer. Analytical expressions obtained forP _a andR _t clearly indicate their use and efficiency for source characterization. It is believed that these results may be of use to investigators in areas like control systems and signal processing also     

某实时控制系统在QNX上的具体实现

简述了QNX实时操作系统的特点，详细介绍了一实时控制系统在QNX4．25上的具体实现。     

单光子时间分辨在线谱仪系统中的接口电路

本文介绍单光子时间分辨在线谱仪系统中的多道分析器与IBM PC/XT微型计算机接口的工作原理及控制程序。     

Lyapunov‐stable discrete‐time model reference adaptive control

Discrete‐time model reference adaptive control (MRAC) is considered with both least squares and projection algorithm parameter identification. For both cases complete Lyapunov proofs are given for stability and convergence. The results extend the approach of Johansson (Int. J. Control 1989; 50 (3):859–869) to include Lyapunov stability for MRAC when the normalized projection algorithm is used for parameter identification. Copyright © 2005 John Wiley & Sons, Ltd.     

The Effect of Post-Cooking Holding Times on Sensory Assessment of Low- and High-Fat Beefburgers

ABSTRACT: The effect of post-cooking holding-time on sensory assessment of low (89 g/kg) and high (218 g/kg) fat beefburgers was assessed. Burgers were served to panelists approximately 3 or 18 min after cooking. Fat content influenced fattiness, moistness/juiciness and overall appearance (P < 0.05), overall acceptability and overall texture (P< 0.01) and tenderness and crumbliness (p<0.001). Burgers with the higher fat content had higher scores. Holding-time influenced sensory overall appearance only with lower scores at extended holding times (P < 0.01). Treatment differences were small, mostly less than one sensory scale unit. Higher lightness and yellowness values were found for burgers with higher fat contents.     

紧凑型FLC光纤PDL模块

描述了紧凑型FLC（铁电液晶）光纤PDL（光子延迟线）模块的结构和运转特性；分析了插入损失；提出多信道运转时依赖于波长的设计方案。     

液位定量式灌装机的灌装精度概率模型与可靠度计算模型

描述了控制液位定量式灌装机的灌装时间与灌装精度的关系，推导出实际灌装时间的理论计算公式。针对实际存在的各种随机变量对灌装时间的影响，建立了灌装时间的概率模型，提出基于灌装时间随机误差的灌状精度以及灌装精度可靠度概念，并相应建立出灌装精度概率模型与灌装精度可靠度计算模型。     

A novel method of suppressing the inrush current of transformers by using a series‐connected voltage‐source PWM converter

This paper proposes a novel method of suppressing the inrush current of transformers. A small‐rated voltage‐source PWM converter is connected in series to the transformers through a matching transformer. As the connected PWM converter serves as a resistor for the source current, no inrush phenomena occurs. The required rating of the PWM converter, which serves as the damping resistor for the inrush phenomena, is 1/400 that of the main transformers in single‐phase circuits. In three‐phase circuits, it is 1/900. The basic principle of the proposed method is discussed. Digital computer simulation is implemented to confirm the validity and excellent practicability of the proposed method using the PSCAD/EMTDC. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed method can perfectly suppress the inrush phenomena. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(4): 56–65, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20174     

Process Variables, Gelatinized Starch and Moisture Effects on Physical Properties of Mungbean Noodles

The effects of amounts of gelatinized starch and moisture in the final slurry or dough, cooking time, holding time, and holding temperature on physical properties of mungbean noodles were studied. Cooking loss, cutting stress, work to cut, and transparency of noodles were measured. Moisture content of the final slurry or dough, cooking time, and holding temperature were the most important factors that affected physical properties of mungbean noodles. Processing should be done at moisture contents not exceeding 55%, cooking times not longer than 40 set, and holding temperatures not lower than 3° using 5% of total starch as gelatinized starch and holding time of 36 hr.     

方波信号在音频技术中的应用

本文重点介绍了方波依赖在音频测量，设备的维护检测及录音均衡自动调节等音频技术中的应用，并通过对方波信号的频谱特性和方波信号通过线性系统的频域特性的分析，简要说明了方波信号在应用电路中的基本工作原理。