On the design of optimal output feedback control systems†

For a linear control system with quadratic performance index the optimal control takes a feedback form of all state variables. However, if there are some states which are not fed in the control system, it is impossible to obtain the optimal feedback control by using the usual mathematical optimization technique such as dynamic programming or the maximum principle.

This paper presents the optimal control of output feedback systems for a quadratic performance index by using a new parameter optimization technique.

Since the optimal feedback gains depend on the initial states in the output feedback control system, two cases where (1) the initial states are known, and (2) the statistical properties of initial states such as mean and covariance matrices are known, are considered here. Furthermore, the proposed method for optimal output feedback control is also applied to sampled-data systems.     

Precise Determination of the 3CaO·SiO2 Cells and Interpretation of Their X-Ray Diffraction Patterns

The cell dimensions of pure triclinic 3CaO·SiO₂ and monoclinic 3CaO·SiO₂ solid solution (54CaO·16SiO₂·Al₂O₃·MgO) were determined and the powder diffraction patterns were indexed by the method of precise measurement of the spacings. The lattice constants are expressed in terms of triclinic or monoclinic cells corresponding to pseudo-orthorhombic cells derived from Jeffery's trigonal cell. The apparent lattice constants for pure 3CaO·SiO₂ are a = 12.195 a.u., b = 7.104 au., c = 25.096 a.u., α= 90°, β= 89°44'γ= 89°44'; for 54CaO·16SiO₂.-Al₂O₃MgO, a = 12.246 a.u., b = 7.045 a.u., c = 24.985 a.u., β= 90°04'. Precise lattice constants of Jeffery's monoclinic lattice for 54CaO.-16SiO₂-Al₂O₃·MgO are derived as a = 33.091 a.u., b = 7.045 a.u., c = 18.546 a.u., β= 94°08'. High-temperature X-ray patterns showed that pure triclinic 3CaO·SiO₂ transformed to a monoclinic form at about 920°C. and then to a trigonal form at about 970°C. Monoclinic 54CaO.16SiO₂·Al₂O₃–MgO transformed to trigonal at about 830°C. These transitions were reversible and reproducible and were accompanied by only slight deformation of the structure forms.     

Kinetic Studies of Eutectoid Decomposition of CuFe5O8

The kinetics and mechanism of eutectoid decomposition of CuFe₅O₈ were studied by X-ray diffractometer, electron probe microanalyzer, and reflecting-light microscope techniques. The isothermal decomposition curves were sigmoidal and the maximum rate of decomposition occurred at ∼600°C. Sigmoidal-type curves indicated that the decomposition proceeded by a process of nucleation and growth. Kinetic data were best expressed by Avrami's equation with n≃2 and n≃4 below and above 850°C, respectively. A "site saturation" mechanism is suggested. Bainite-type and pearlite-type microstructures were observed below and above 800°C, respectively. Grain boundaries were active sites in the nucleation process.     

Effects of Thermal Treatment on Radical-scavenging Activity of Single and Mixed Polyphenolic Compounds

ABSTRACT: Rutin, luteolin, luteolin-7-glucoside, and chlorogenic acid gradually decomposed during heating at 100°C. Even though they rapidly decomposed at 180°C, some decomposition products still had radical-scavenging activity. When rutin was heated in the presence of chlorogenic acid, decomposition of rutin was almost totally inhibited at 100°C, but was reduced at 180°C. These results suggest that the radical-scavenging activity is more stable than the content of original polyphenolic compounds in foods during cooking and processing.     

Project Execution Capability, Organizational Know-how and Conglomerate Corporate Growth in Late Industrialization

In many successful late-industrializing countries in the 20thcentury, business groups with operating units in technologicallyunrelated industries have acted as the microeco-nomic agentof growth. This paper explores why this business form has characterizedcountries which industrialized ‘late’, and why thisform succeeded in the early phases of catching up whereas theadvanced-country conglomerate has had an undistinguished performance.The paper uses internal resource-base theories of the firm toexplore the significance of organizational knowledge and resultingincreasing returns in the group form which, even in mature marketsand especially in late industrialization, constitute a sustainablesource of competitiveness. In the case of late industrializationforeign technology acquisition capability became a necessarycondition for corporate success. In the best diversified businessgroups this capability was transformed into organizational knowhow that provided a key resource in the effectiveness of corporategrowth through diversification. The first two parts of the paperbriefly survey diversified industrial groups in historical contextsand then across a broad array of late-industrializing countries.Then the paper considers why diversification was not prevalentamong firms attempting to catch up in earlier historical periods,why the strategy of leading late industrializing firms was oneof diversification rather than specialization and why theirchosen diversification path was one involving technologist collyunrelated industries. This is followed by the core argumentof the paper about the transformation of technology acquisitioninto a competitive asset and illustrated with evidence fromSouth Korea. Finally, the paper analyzes why the behavior ofthe late industrializing group differs from that of the Americanconglomerate.     

Al_4O_4C的碳热还原合成及其反应动力学

以氧化铝(Al2O3)和石墨(C)为原料,采用碳热还原工艺合成铝氧碳(Al4O4C),借助于X射线衍射仪和场发射扫描电子显微镜研究了加热温度和保温时间对合成铝氧碳(Al4O4C)的影响。结果表明:提高加热温度,可加快Al2O3和C反应生成Al4O4C的反应速率;延长保温时间可增大Al2O3和C反应生成Al4O4C的反应程度。在反应初期主要为固-固反应,Al2O3和C直接接触反应生成Al4O4C和一氧化碳(CO);后期主要为气-固反应,Al2O3和CO气体反应生成Al4O4C和二氧化碳(CO2)。计算得到气-固反应的频率因子和活化能分别为338.66和264.19kJ/mol。     

CARCINOGENICITY TEST OF QUERCETIN AND KAEMPFEROL IN RATS BY ORAL ADMINISTRATION

Quercetin and kaempferol were tested for carcinogenicity in rats of both sexes. In Experiment I, 0.1% quercetin or control diet was given to Fischer 344 rats for 540 days. In experiment II, 0.04% kaempferol or control diet was given to ACI rats for 540 days. In both experiments, most tumors found in the experimental groups were also found in the corresponding control groups, and there were no statistical differences in the incidences of tumors in the experimental groups and the respective control groups. Quercetin and kaempferol were not shown to be carcinogenic to rats under these conditions.