Error analysis of fixed-point prediction with coloured measurement noise

The main purpose of this paper is the error analysis of the fixed-point prediction for the linear continuous-time system with the coloured measurement noise. In the first part of this paper we derive an algorithm for the fixed-point prediction with the coloured measurement, noise from the given system. The remaining part presents the error analysis of the fixed-point prediction due to two causes, one of which is misidentifying the coefficients of the system and the covariances of the noises and the other of simplifying the coloured measurement noise by a white measurement noise. For the above cases two differential equations are obtained which govern the actual covariances regarded as the error quantities.     

Parameter identification for a two-dimensional image fieId†

This paper presents a new approach to image enhancement based on a maximum likelihood identification method. It is assumed that the images are corrupted by a white gaussian noise field. A two-dimensional extension of the classical ARMA model is developed as a mathematical model for the image fields. Since the maximum likelihood identification leads to a parametric optimization problem, Davidon's algorithm is applied for numerical solutions. The advantage of the present method is that the enhanced images based on the predicted estimates are directly obtained from the noise-corruptod images, so that the autocovariance function of the original image is not required. To improve the quality of the enhanced images, a filtering algorithm is also derived. Digital simulation studies are carried out for various artificial images to show the feasibility of this approach.     

BEHAVIOR OF A MINUTE AMOUNT OF DIETHYL SULFIDE IN HYDROCARBON DISTILLATION

Vapor-liquid equilibria of 2,2,4-trimethylpentane(T)-hexane(H), T-cyclohexane(C) and T-methylcycIo-hexane(M) systems containing a minute amount of diethyl sulfide(D) were measured at atmospheric pressure. Continuous distillation experiments of the above systems were carried out in an Oldershaw type column. The Murphree vapor efficiencies of the major and the trace components were obtained.

In the T-H-D system, in which the trace component is a typical “intermediate volatility” component, the Murphree vapor efficiency of the trace component varies remarkably and exhibits an unreasonable value, in contrast to that in T-C-D and M-T-D systems.     

Retort Temperature Profile for Optimum Quality during Conduction-Heating of Foods in Retortable Pouches

The optimal control theory was used to determine the optimum retort temperature profile for quality retention at a given level of sterilizing value in conduction-heating of foods in retortable pouches. The cook-value (C-value) was employed to describe quality changes. Optimization was considered to be a constrained optimal control problem with unspecified terminal time, and it was solved numerically, using the conjugate gradient minimization method. Optimum retort temperature profiles were determined for the volume average and surface C-values for browning reactions. Final C-value for volume average decreased by 10% as compared with that for optimum constant retort temperature, and the value for surface decreased by 30%. This method may be applicable to heat sterilization of canned foods as well.     

PARTIAL PURIFICATION AND PROPERTIES OF PUMPKIN LIPOXYGENASE WITH CAROTENE-BLEACHING ACTIVITY

From locally grown pumpkins, an active lipoxygenase preparation with an active carotene-bleaching factor was partially purified by ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. The enzyme had a pH optimum at 6.5 and was inactive at pH below 3 and above 10. The maximum activity occurred at 30°C. The apparent K_m determined in the presence of linoleate was 0.33 × 10^?3 M. The heavy metals Hg²⁺, Cu²⁺, Co²⁺, and Fe³⁺ were effective inhibitors of this enzyme. Cyanide, fluoride, and L-ascorbic acid also inhibited lipoxygenase activity. Carotene-bleaching activities operated strongly on the lipoxygenase fraction and slightly on the denatured lipoxygenase and hemoproteins treated with heat.     

一株耐盐菌EC51的生长特性及其系统发育分析

从大连市普兰店盐场盐池底部的淤泥中筛选出一株耐盐菌EC51,研究了分离菌株的形态和生长特性,该菌株为革兰氏阳性杆状菌.以其16S rDNA 序列相似性为基础构建系统发育树.结果表明,EC51与Bacillus Pumilus的相似性达到99%.耐盐菌EC51的渗透压补偿溶质（Ectoine）生成情况实验表明,用含2 mol/L NaCl的肉汤培养基,在30 ℃条件下培养48 h,诱导生成Ectoine为197.8 mg/L.