Structured system models Part 3. An application to feedback compensator design

The controllability and observability indices are studied and applied to the feedback compensator design. The compensator design method uses polynomial matrices as system models. As the main result, a new algorithm is introduced for the construction of a first candidate for the feedback compensator. A new algorithm is also given for constructing a state-space model from polynomial matrix models. Such a realization is needed if there is originally only a polynomial matrix model for the system.     

Structured system models Part 2. Directed graphs and boolean matrices

Parameterized system models and their augmented controllability indices are studied. Analytically parameterized system models arc shown to have generic index lists, i.e. lists which arc actual lists for all parameter values except those in a proper analytic variety. For structured system models, as a subset of analytically parameterized system models, there exists a known graph-theoretic method for determining the Hermite indices. A new method for examining both Hermite and Kronecker indices is introduced. The method is based on a necessary graph-theoretic condition for the examined columns of the controllability matrix to be linearly independent. Additional sufficient conditions are given to complete the method. The given graph-theoretic results are also expressed using boolean matrices associated with graphs.     

Formation of Biogenic Amines during Ripening of Dry Sausages as Affected by Starter Culture and Thawing Time of Raw Materials

Raw materials affect formation of biogenic amines in dry sausages. Effects of thawing time of raw materials and amine-negative starter culture on amine formation were studied on a pilot scale. The levels of biogenic amines, precursor amino acids, pH, water activity, and microbial counts were measured. Use of starter culture significantly decreased levels of histamine, tyramine and cadaverine formed. The effect of thawing time on formation of biogenic amines was dependent on the use of starter culture.     

基于原子力显微镜的沥青微观结构研究

采用原子力显微镜和均方根粗糙度参数研究了沥青种类、短期老化以及制样过程中冷却速率对沥青微观结构的影响。结果表明,不同沥青的蜂状结构尺寸、数量不尽相同,对短期老化的敏感性也不相同,而制样过程中冷却速率对蜂状结构的影响十分显著;同时,在沥青表面应力松弛过程中,不同区域的蜡链排列倾角存在差异是蜂状结构呈正弦波形式(波长约为500nm)的原因。根据相分离理论分析实验现象后得出,沥青质及胶质与蜡之间的相互作用是影响沥青相分离行为的重要因素。     

ON SENSITIVITY ANALYSIS AND OPTIMAL DESIGN OF SPECIALLY ORTHOTROPIC LAMINATES

Sensitivity analysis with respect to fibre orientation as well as to ply thickness is performed for specially orthotropic laminates. Eigenfrequencies, buckling load and displacement are all related to the same non-dimensional functional, which is therefore taken as the objective for our optimization.

If the laminates are assumed to be made of plies of the same material, then closed form results are obtainable, and it is essential that these results are well understood. For more advanced models the main parameters will be same and so will the main aspects of the sensitivity analysis.

The principal conclusions of this unconstrained optimization are that the optimal fibre orientation depends mainly on the displacement mode and that the problem of optimal thickness distribution is not well-defined.