Static Output Feedback Stabilization: An ILMI Approach

In this note, the static output feedback stabilization problem is addressed using the linear matrix inequality technique. A necessary and sufficient condition for static output feedback stabilizability for linear time-invariant systems is derived in the form of a matrix inequality. The extension of the result to H_∞ control is studied. An iterative LMI (ILMI) algorithm is proposed to compute the feedback gain. Numerical examples are employed to demonstrate the effectiveness and the convergence of the algorithm.     

Mathematical modelling of an aquatic ecosystem I

This paper presents a mathematicfa1 model of an aquatic ecosystem. The model differs from previous models in that it incorporates characteristics of specific phyla of phytaplankton and zooplankton, inter and intra-phyla interaction and limiting nutrient processing by decomposers.     

Discrete calculus of variations

This paper develops the concept of discrete calculus of variations and then demonstrates its application to optimisation problems for discrete systems. The parallels between this concept and classical calculus of variations are stressed throughout.     

A note on the observed and predicted flow patterns around islands— Flat Holm,the Bristol Channel

Abstract

Multispectral scanner (MSS) data from the Natural Environment Research Councils (NERC) aircraft flown over the island of Flat Holm in the Bristol Channel, U.K. have been used in association with a System Probatoire d'Observation de la Terre, high-resolution visible scanner (SPOT HRV) image of the same area to identify the major surface water flow patterns around the island. Theoretical scaling parameters for shallow water flows are used to predict wake form and compared with the MSS and SPOT HRV images. Initial results indicate that the mathematical approach gives a useful approximation to the observed flow patterns though additional information on tidal currents throughout the tidal cycle and detailed bathymetry in the area are required to further the predictive model.     

Preparation and Properties of the Boron Phosphides

The reactions between boron and phosphorus to form the boron phosphides are described. The elements were compacted into pellets and dropped into a preheated reaction zone. The reaction between zinc phosphide and boron also resulted in the formation of the boron phosphides and the complete removal of zinc in the vapor phase. Cubic BP formed initially and decomposed into the rhombohedral B₁₃P₂ above 1130°C. The formation of B₁₃P₂ by decomposition of BP was rapid and complete at 1600°C. Some properties of BP and B13P2 are summarized. The B₁₃P₂ formed by decomposition was a very fine powder and large crystals were grown in metallic melts.     

SCALE‐UP and FIELD TEST of the VACUUM/STEAM/VACUUM SURFACE INTERVENTION PROCESS FOR POULTRY1

The Vacuum/Steam/Vacuum surface intervention pilot plant processor was scaled up to a mobile unit that can be transported to close proximity of chicken processing plants. After several modifications to the mandrel that supports the broiler carcass in the treatment chamber to minimize mechanical damage, the unit was capable of 1.1 log cfu/mL kill of inoculated Listeria innocua and 1.4 log cfu/mL kill of inoculated E. coli K‐12. Field tests achieved 1.4 log kill of E. coli and 1.2 log kill of Campylobacter on freshly processed chicken using 3 cycles and 138C saturated steam. But, there was extensive mechanical damage. the mandrel was modified in the Eastern Regional Research Center pilot plant to eliminate the mechanical damage. With mechanical damage eliminated, the bacteria kill was 1.1–1.5 log of inoculated E. coli K‐12 with a total process time of 1.1 s.     

Designing performance measurement systems for just-in-time operations

Results of a study conducted to understand how performance is evaluated in just-in-time (JIT) operations are reported in this paper. The purpose of the study was to develop a series of propositions concerning the performance criteria, standards, measurement techniques, and reporting methods that are appropriate in JIT environments. Ten propositions are provided.     

Effect of Atmosphere on the Electrical Conductivity of Sodium Tungstophosphate Glasses

The dc electrical conductivity of sodium tungstophosphate glasses was measured as a function of glass composition, melting history, and ambient atmosphere. The color of the glasses was a strong function of both glass composition and melting history. The electrical conductivity was found to be strongly dependent upon the concentration of protons in the surrounding atmosphere. The colorless glasses were found to be electrochromic only so long as protons were present in the atmosphere. A model is suggested to explain these results.