Analysis of time-delay systems using an alternative technique

The Taylor delayed operational matrix is first developed. With the introduction of the Taylor product matrix, the Taylor series approximation can be extended to the analysis of time-varying systems. The method is better than that using Walsh series, as demonstrated by numerical examples. The result is quite satisfactory.     

Manoeuvring target tracking in a cluttered environment from noisy images by an adaptive probabilistic data association filter

A new tracking method for estimating motion parameters of a manoeuvring target in a cluttered environment from noisy image sequences is presented. Traditionally, tracking systems have been broadly classified according to (1) moving target with or without manoeuvring, and (2) tracking in a clean (uncluttered) or cluttered environment. The difficulties studied here are those arising from (a) unknown acceleration inducing a randomly updated trajectory, and (b) the disturbance of returns from false alarms or other interfering objects. The probability data association filter (PDAF) is augmented by the semi-Markov process, called the adaptive PDAF, to handle the difficulties. Since the acceleration state applied either by a pilot or by a guidance control system is independent of the appearance of false returns, the treatment of target manoeuvring and false returns are separated into two sub-problems, i.e. the PDAF is applied to govern the disturbance of multiple returns and the semi-Markov process is applied to estimate uncertain accelerations. Three simulation results of variations show small biases from the true trajectory. By comparing with a nearest neighbour standard filter, the proposed tracking system also demonstrates better results.     

新型的电力电子系统单一传感器预测控制技术

该文概述了一种简单且有效的单一传感器预测技术(Single Sensor Estimation Technique，简称SSET)的基本原理及其在电力电子系统中的应用。仅需一个传感器测量电感电流或电感电压，该技术能够为反馈控制、前馈补偿以及参数监控等提供足够的信息，整个系统不需要其他传感器。该文在一个有源功率因数校正器和一个荧光灯的电子镇流器上分别验证了SSET的可行性，实验结果证明SSET能够正确地估算所需的各类变量和参数，从而达到系统控制和参数监控的目的。该技术不仅能够减少传感器的数量，而且可以避免在电力电子系统中使用复杂的电气隔离电路。     

结合可中断合同交易的电力系统随机生产模拟

提出了一种结合可中断电力合同交易的电力系统随机生产模拟方法,其中把可中断电力等效为具有随机停运特性的灵活发电资源.考虑了可中断合同定价模型与合同交货时段系统边际运行成本之间的相关性问题,并采用一种迭代协调算法来加以解决.该方法可用于分析可中断电力合同交易对于系统发电可靠性和经济性的影响,以及考虑系统需求不确定性和发电机组故障的可中断电力合同的系统决策.算例仿真验证了该方法的有效性,并且表明在不确定环境下要求以尽可能小的成本来保证系统适当可靠性水平时,可中断电力合同交易具有重要应用价值.     

PHYSICAL,CHEMICAL, and THERMAL CHARACTERIZATION of WHEAT FLOUR MILLING COPRODUCTS1,2

Hard red winter (HRW) and hard red spring (HRS) wheat milling coproducts (bran, germ, shorts, and red dog) from three commercial flour mills and the Kansas State University pilot mill were evaluated for differences in physical, chemical, and thermal properties. the ranges of bulk density for bran, germ, and red dog determined at three moisture levels were 146.5 to 205.2 kgm^?3, 269.2 to 400.6 kgm^?3, and 298.9 to 398.1 kgm^?3, respectively. the true density ranking order was: red dog >shorts = germ >bran, independently of the moisture level. Red dog had the smallest geometrical mean diameter with the highest variation (coefficient of variation of 23.8%). There was a significant (P < 0.05) difference among wheat blends and milling flows in the thickness of bran and germ at the same particle separation size. the image analysis study determined that the equivalent projected area diameter of bran at the same separation size was significantly (P < 0.05) larger than that of germ. the ratio between the equivalent projected area diameter and the particle thickness were within ranges of 15.7 to 37.6 for bran and 15.5 to 32.2 for germ particles. the chemical composition (ash, protein, lipids and fiber) ranges were determined for each coproduct. Ranges of thermal conductivity for bran, germ, shorts, and red dog were 0.049 to 0.074, 0.054 to 0.0907, 0.057 to 0.076, and 0.063 to 0.080 W(mK)^?1, respectively. Specific heat of coproducts, measured with a differential scanning calorimeter, exhibited a wider range [1.08–1.94 kJ(kgK)^?1] than that observed in whole wheat kernels and wheat flour. the variability observed among the samples was due to the different wheat sources and characteristic milling flows for the flour mills.     

INDUCTION OF APOPTOSIS BY GINSENG SAPONIN METABOLITE IN U937 HUMAN MONOCYTIC LEUKEMIA CELLS

We report the cytotoxicity of the ginseng saponin metabolite, Compound K (20‐O‐D‐glucopyranosyl‐20(S)‐protopanaxadiol, IH901) on various human leukemia cell lines. Compound K had the most effect on U937, a human monocytic leukemia cell line among the tested cell lines. Compound K‐treated U937 cells showed characteristics of apoptosis: an exposure of phosphatidylserine from the inner cell membrane to the outer cell membrane, the formation of apoptotic bodies and DNA fragmentation. Compound K induced apoptosis by up‐regulating Bax, disrupting the mitochondrial membrane potential, and by activating caspase 9 and caspase 3. Therefore, we suggest that Compound K inhibits U937 cell growth by inducing apoptosis through the up‐regulation of Bax and caspase activation.     

IDENTIFICATION OF HURDLES FOR IMPROVING STORAGE STABILITY OF BRAISED KIDNEY BEANS, A KOREAN SEASONED SIDE DISH

The aim of this study was to identify factors affecting the preservation of braised kidney beans, a traditional Korean side dish, to extend its shelf life. The effects of ingredient formulation, refrigerated storage and modified atmosphere packaging on storage stability and/or sensory quality were examined. Count of yeast/mold was selected as a primary quality index from the storage test at 10C. A formulation was found in cooked kidney beans, sugar, soy sauce and corn syrup to provide the retarded microbial growth and affordable sensory quality. The temperature dependence value (Q₁₀) for the shelf life of the stretch-wrapped product was 2.0 for temperatures of 5 to 20C. Modified atmosphere packaging (60% CO₂/40% N₂ or 100% CO₂) extended the shelf life at 10C by 500% (to 36 days) compared to air packaging (6 days) based on criteria of yeast/mold growth. Equations for estimating microbial spoilage and shelf life were derived as function of temperature.

PRACTICAL APPLICATIONS

Microbial growth retardation by ingredient formulation change, chilled storage and high CO₂ modified atmosphere packaging is useful to design the processing, packaging and distribution of the Korean side dish product. Quality change kinetics of yeast/mold growth established can be used for determining shelf life of the product under different storage temperature conditions. Through the scale-up procedure, the knowledge found in this study will be useful for the industrial processing and storage of the seasoned side dishes.     

考虑负荷和风电出力不确定性的输电系统机会约束规划

提出了一种考虑负荷和风电场输出功率不确定性、基于机会约束规划的输电系统规划方法。将Monte Carlo方法与解析的概率潮流计算方法相结合,得到含风电场电网输电线路的有功概率潮流分布。通过改进经典的输电系统规划模型,得到考虑负荷和风电场有功出力的概率分布、基于概率潮流计算的输电系统机会约束规划模型。为了有效求解该模型,设计了一种两步式遗传算法。该方法可以有效处理输电系统规划中的不确定性,并为规划人员提供比传统方法更丰富的信息。算例证明了该方法的有效性。     

Fe-Mn-Si形状记忆合金在不同热机械循环条件下γ→ε马氏体相变的电子显微镜分析

测定了Ｆｅ３３７（ｗｔ）％Ｍｎ５２２（ｗｔ）％Ｓｉ形状记忆合金在不同变量和不同回复温度的热机械循环（简称“训练”）条件下的形状记忆效应（ＳＭＥ）。通过电子显微分析观察到应力诱发马氏体均为薄片层组织。在应变量过大或回复不充分的训练过程中，位错的增殖会破坏这种片层组织并影响晶体学的可逆性，同时使形状记忆效应恶化。