Unified approach to H∞-optimization,Hankel approximation and balanced realization problems

A unified approach is proposed here to solve three problems simultaneously, namely H ∞ -optimization, Hankel approximation and minimal balanced realization for scalar systems. It is shown that all these problems can be reduced to the same standard form wherein merely the singular-value decomposition (SVD) of an easily constructed square matrix is required to establish the final solutions. The formulation is solely in terms of the coefficients of a transfer function and the resulting algorithm can be performed in a very computationally efficient way.     

沥青路面拥包三维指标计算方法

为全面、准确评价沥青路面拥包严重程度,实现三维指标的自动计算,利用室内三维激光检测设备获取高精度、高密度的拥包模型激光点云数据,采用Lowess算法进行数据预处理,再利用RANSAC算法获取拥包下底面轮廓数据,基于HARR矩阵建立拥包三维模型.在此基础上,利用高差法和微元逼近法分别计算了拥包的最大高度、下底面积、隆起体积与行车方向最大坡度等三维指标;对比轻、重两个严重等级的拥包三维指标计算结果,研究激光线纵向间距对指标计算误差的影响规律.结果表明:当激光线纵向间距为0.5 mm时,拥包最大高度、下底面积、隆起体积和行车方向最大坡度的相对误差分别不超过3.28%、2.17%、3.76%和1.97%;随着激光线纵向间距逐渐增大至10 mm,拥包三维重构模型产生部分缺失,导致拥包三维指标相对误差逐渐增大;当间距为5 mm时,三维指标计算最大相对误差分别为3.49%、4.65%和7.11%和7.27%;当间距为10 mm时,隆起体积和行车方向最大坡度的相对误差均超过10%;建议采用三维激光技术对拥包进行检测时,纵向间距设置不大于5 mm,以保证拥包三维指标计算结果准确性.三维指标计算方法可评价拥包严重程度,评估行车安全风险.     

Comparison of batch and continuous oxidation processes for producing carbon fibre based on PAN fibre

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

ASSESSING PHYSICAL PROPERTIES OF RESTRUCTURED BEEF PRODUCTS DURING CONVECTIVE HEATING

Restructured beef roasts are useful alternatives for foodservice or home meal replacement and it is important that uniformity of preparation and quality can be achieved for key markets. Two sizes of restructured beef roasts were heated to various internal temperatures (35–65C) to determine effects on selected physical properties of a _w pH, water-holding capacity (WHC), water absorption (WAC) and moisture content. The a _w was least affected (0.985–0.987), but all other properties were affected by endpoint temperature, slice position (section) and sample depth (location). Moisture content was greatly affected with outer layers having lower values. The pH increased 0.06 to 0.21 units depending on temperature and location. WHC decreased while WAC increased as endpoint temperature increased to 65C, but section and location also had an impact. Before denaturation of meat protein is complete, it appears the physical properties are highly influenced by the product temperature and therefore final quality can be modified by altering endpoint temperature.     

EVALUATION OF THE TOXICITY OF LACTOBACILLUS ACIDOPHILUS LAP5 IN A 28-DAY FEEDING STUDY IN WISTAR RATS

We have previously screened lactic acid bacteria strains from porcine intestine and evaluated their functional properties. We found a strain of Lactobacillus acidophilus LAP5 is with potential for use as human and animal probiotics. However, the safety of the strain in consideration must be evaluated. The present study was conducted to evaluate the toxicity of strain L. acidophilus LAP5 in Wistar rats by dietary administration at concentrations of 2.1 × 10¹¹, 1.05 × 10¹¹ and 4.2 × 10⁹ CFU per kg body weight of rat per day for 28 days. There were no adverse effects on the general condition and behavior, growth, feed and water consumption, hematology, clinical chemistry indexes, organ weights and histopathologic analysis. Results of this study demonstrated that consumption of strain L. acidophilus LAP5 was not associated with any signs of toxicity in Wistar rats even following consumption of large quantities.     

Water Binding Measurement of Meat

A quick technique for measuring cooking yield based on microwave heating was compared with a modified cooked-centrifuge technique for determining water holding capacity and both were compared with the standard raw-press technique for determining water holding capacity. In general the results of the three methods were highly correlated; however, limitations of each method were noted. The effects of additives such as salt, phosphate and binders were evaluated along with the effects of time postmortem and freezing-thawing. The influence of fat was also evaluated and a variety of sausage raw materials were analyzed by the three techniques.     

EFFECT OF DIETARY FIBER ON THE PREVENTION OF LIVER LIPID ACCUMULATION INDUCED BY HIGH POLYUNSATURATED OIL

This study investigated whether dietary fiber can prevent the accumulation of liver lipids due to the ingestion of polyunsaturated oil. Fifteen percent fish oil (FO) was added to the basal diet as a source of polyunsaturated oil. Ten percent cellulose, pectin, guar gum, konjac mannan or gum Arabic was mixed in the diet as a source of dietary fiber. Commercial Purina rat chow was used as a control and a fiber-free (blank) diets were also employed in the study. Each experimental diet was fed to each group of 6 Wistar rats for 8 weeks. Fish oil feeding lowered the plasma triacylglycerols (TG) and cholesterol (CS) levels. Rats fed a fiber-free diet had higher liver weights indicating hepatomegaly and a marked accumulation of liver lipids. With the exception of cellulose and gum Arabic, the inclusion of dietary fiber in FO diets lowered the plasma total lipids and CS; plasma TG was unchanged. Pectin and guar gum enhanced the CS-lowering effect of the FO diet. All of the test fibers, but especially pectin and guar gum, reduced the accumulation of total lipids, TG and CS in rat liver caused by dietary FO. Hepatic glucose-6-phosphate dehydrogenase activity was reduced in rats fed FO, but dietary fiber had no effect on the activity of this enzyme.