Relations between coefficients of the closed-loop characteristic polynomial and output-feedback gains

This paper deals with explicit analytical dependencies between all coefficients of the closed-loop characteristic polynomial and all entries of the output feedback matrix. First, a special kind of non-linear relation that occurs is explained. Next, computationally-efficient formulae are discussed that yield closed-loop characteristic polynomial coefficients with explicit feedback gain dependence. Then it is shown how the closed-loop characteristic polynomial is associated with the transfer function matrix of the open-loop system. Finally, the results obtained are interpreted graph-theoretically.     

DOMAIN APPROXIMATION AND DETERMINISTIC PROGRESSION IN GENETIC CROSSOVER

The fitness difference between two strings is usually neglected by most Genetic Algorithm crossover operators. The neglect of this useful information often results in the less efficient propagation of search trials toward fitness improved regions, and leads to a general increase in the number of function evaluations required to converge to a solution. An alternative crossover strategy is presented in this paper which considers this information, often significantly accelerating and enhancing the search process. The presented strategy involves components of solution domain approximation and the deterministic estimation of the “optimal” genetic composition for progeny. The implementation of this crossover scheme has empirically demonstrated its effectiveness in significantly reducing the required number of function evaluations, and improving solution quality compared with some conventional crossover strategies     

SENSITIVITY OF LISTERIA MONOCYTOGENES TO SPICES AT TWO TEMPERATURES

Thirteen spices were screened for growth inhibition effect against Listeria monocytogenes at 24°C using a concentration gradient plate method. Cloves, and oregano were the two most inhibitory spices with MIC values ranging from 0.5 to 0.7% (W/V). Inhibition was also detected with sage and rosemary (MIC of 0.7 to 1.0%) as well as nutmeg (MIC of 1.1–1.4%). Black pepper, chili, cinnamon, garlic, mustard, paprika, parsley and red pepper at a concentration up to 3.0% did not inhibit the growth of the organisms. The effect of cloves, oregano and sage on the growth and survival of L. monocytogenes Scott A was further tested in tryptic soy broth at both 4 and 24°C. At a concentration of 0.5 or 1.0%, cloves were bactericidal and oregano was bacteriostatic to this organism at both incubation temperatures. Sage at these two concentrations was bactericidal at 4°C and bacteriostatic at 24°C. When tested in sterile meat slurry, a 1.0% level of either cloves or oregano had little effect on the growth of L. monocytogenes Scott A at 4 or 24°C.     

EFFECTS OF SENSORY AND PERCEPTUAL DEPRIVATION ON A BATTERY OF OPEN-ENDED COGNITIVE TASKS.

2 EXPERIMENTS WERE CONDUCTED WITH 43 MALE COLLEGE SS TO TEST THE HYPOTHESIS THAT PERFORMANCE ON OPEN-ENDED COGNITIVE TESTS WILL BE IMPAIRED BY EXPOSURE TO AN IMPOVERISHED SENSORY ENVIRONMENT. THE GUILFORD BATTERY OF CREATIVE THINKING (10 TESTS) WAS ADMINISTERED BEFORE AND AFTER 3 DAYS OF EITHER SENSORY DEPRIVATION (DARKNESS AND SILENCE) OR PERCEPTUAL DEPRIVATION (UNPATTERNED LIGHT AND WHITE NOISE). IN BOTH EXPERIMENTS, NO SIGNIFICANT DIFFERENCES WERE FOUND BETWEEN THE ISOLATED AND CONTROL SS ON ANY OF THE TESTS. HOWEVER, WHEN DATA OF THE 2 EXPERIMENTS WERE COMBINED, THE ISOLATED SS PERFORMED SIGNIFICANTLY WORSE THAN DID CONTROLS ON A TEST OF IDEATIONAL FLUENCY. IT WAS ALSO OBSERVED THAT THE PREEXPERIMENTAL SCORES OF A GROUP OF 6 ISOLATION QUITTERS WERE CONSISTENTLY LOWER, RELATIVE TO THOSE OF THE SUCCESSFUL ISOLATION ENDURERS AND CONTROLS, ON ALL 10 TESTS. ALTHOUGH NONE OF THE DIFFERENCES WERE STATISTICALLY SIGNIFICANT (PROBABLY BECAUSE OF THE SMALL SAMPLE OF QUITTERS), THE RESULTS SUGGEST THAT LOW PREEXPERIMENTAL SCORES ON OPEN-ENDED COGNITIVE TESTS MAY INDICATE ISOLATION INTOLERANCE. (FRENCH SUMMARY) (24 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Algebraic characterization of arbitrary pole assignability by static output feedback”“

Based on the explicit algebraic dependences p — g(F) between the vector p of the closed-loop characteristic-polynomial coefficients and the static output feedback matrix F, the well-known problem of arbitrary pole assignability by static output feedback is considered: local pole assignability is possible if and only if the differential g_* has full rank. Taking advantage of the known analytical dependences of g_*FF on F, new sufficient criteria for global pole assignability are derived. An explicit formula to compute the algebraic submanifold of feedback matrices F for which g_*F does not have full rank is also obtained. If the property of local pole assignability holds, then there exists a smooth submanifold of matrices F each point of which ensures the desired pole assignment. An algorithm by which this smooth submanifold can be computed is outlined. Illustrative examples are discussed in some detail.     

SUSTAINABLE URBAN TRANSPORTATION: A MODEL-BASED APPROACH

Transportation and its environmental impacts are a major component of urban environmental management. At the same time, transportation and mobility are an important part of urban economics and the quality of life. To analyze urban transportation and its environmental impacts, a comprehensive, interdisciplinary approach is needed. No single model can cover the range of spatial and temporal scales and processes involved. This leads to a multi-tiered approach and a cascade of models to describe alternative urban development and transportation scenarios and their multicriteria assessment and comparative analysis. This paper describes the methodology and application examples of Sustainable Urban Transportation (SUTRA) (http://www.ess.co.at/SUTRA/) a City of Tomorrow project under the European Union Energy, Environment and Sustainable Development Research Programme. The primary objective of SUTRA was to develop a consistent and comprehensive model-based approach and planning methodology for the analysis of urban transportation problems and to support design strategies for sustainable cities. This includes an integration of socioeconomic, environmental, and technological concepts including the development, integration, and demonstration of simulation tools to improve scenario design, assessment, and policy-level decision support. Combining an indicator-based approach with simulation models ranging from technoeconomic optimization to street canyon modeling, used for scenario analysis, socioeconomic, and environmental impact assessment, and a web-based public information component, the methodology ranges from awareness building and educational aspects for citizens and stakeholders participating in urban decision-making processes to detailed technical modeling and optimization results for the planning professional. The models employed in SUTRA describe urban development scenarios, their implications for the transportation system, and a range of economic and environmental impacts. Special emphasis was given to emissions and ambient air quality and, in consequence, population exposure and public health consequences, and accidents. The models used range in scale from street-canyon models with time horizons in hours to regional photochemical models considering seasonal patterns, transportation models describing the city and its environs, and technoeconomic models for long-term city-level or regional technological and energy analysis that estimate, inter alia, the market penetration of new transportation technologies over 20- to 30-years planning horizons. The links between the models, as well as the initial scenario assumptions and the overall evaluation framework, are formulated in terms of indicators. The city case studies of the SUTRA project (Buenos Aires, Gdansk, Genoa, Geneva, Lisbon, Tel Aviv, and Thessaloniki) differ widely in terms of culture, environmental conditions, size, economic structure, social composition, and demography. The modeling approach developed was tested against this range of cities of ensure general applicability and at the same time to provide data for a comparative analysis of the scenarios explored.     

RELATIONSHIPS OF COLOR, VISCOSITY, ORGANIC ACID PROFILES AND ASCORBIC ACID CONTENT TO ADDITION OF ORGANIC ACIDS AND SALT IN TOMATO JUICE

Malate and citrate acidified juices produced statistically similar results for pH and titratable acidity (TA), but these acidified juices were significantly different from nonacidified juice when comparing pH and TA. During storage time, the pattern of the pH and TA curves, regardless of acidification, were similar. Salted juice exhibited a significantly higher ascorbic acid content and greater viscosity than did the unsalted juice during storage. The organic acids citric, lactic, malic, and pyrocarboxylic increased immediately after heat processing for commercial sterility, while the presence of salt in this juice lowered these same organic acids. There was minimal correlation of the organic acids or the summation of the acids equivalents of all the organic acids to the titratable acidity or pH of the juices. Juices acidified with malate or citrate did not consistently display an increased level of that specific acid after processing and storage.     

Geotechnical properties of some organoclays

The engineering characteristics of clay are dependant on its mineral and chemical structure. When the clay soils interacted with water, their volume and shear strength and compressibility properties change gradually. Large amount of decrease in terms of the shear strength of clay soils due to swelling is observed. In order to solve these problems, the stabilization of clay soils using chemical additives is a prevalent subject of research. In view of this, previous research studies have employed surface active surfactants to modify the fundamental properties of soft clays. In this study, surfactant–clay complexes (organoclays) were developed using a raw clay modification with four surfactants and their geotechnical properties were determined in laboratory conditions. Two of the surfactants are cationic (cetyl trimethyl ammonium chloride, denoted as CTAC and quaternised ethoxylated fatty amine, denoted as QEFA) and the others are anionic (linear alkylbenzene sulphonic acid, denoted as LABSA and sodium lauryl ether sulfate, denoted as SLES). The experimental results indicated that the geotechnical properties of organoclays show significant change when compared to those of natural clay. The specific gravities, unconfined compression strengths and maximum dry densities of all organoclays were decreased. Optimum moisture content and swelling pressure values were decreased in cationic surfactant modified clays. However, the optimum moisture content and swelling pressure values of anionic surfactant clays are increased. A direct shear test was performed to determine the shear strength of organoclays. The test results also showed that the internal friction angles of organoclays were increased. Additionally, the change in the hydraulic conductivity was found to be insignificant.