Qualitativ-quantitative Simulation, ein Instrument zur Analyse nichtlinearer Regelkreise

Qualitative-quantitative simulation is one of the most productive and promising research areas in Artificial Intelligence to emerge in recent years. This method provides an elegant way for an exhaustive analysis of uncertain dynamic systems. The application of the qualitative-quantitative simulation is shown in this paper. The important question about the stability of a quanlitatively described dynamical system is solved by a novel analytic method.     

From categorial to dimensional diagnosis

The concepts of categorical and dimensional assessment approaches and their specific advantages--and disadvantages are described. A combination of both concepts within the framework of Multiple Assessment of Psychiatric Disturbances is proposed. This includes the different levels of behavioural and emotional disturbances, different assessment methods, the situational specificity of behavioural and emotional disturbances and individually tailored and treatment related assessment procedures. Thereby two phases are distinguished. In the first phase basic procedures of the Multiple Assessment of Psychiatric Disturbances are accomplished, which cover a broad spectrum of behavioural and emotional problems. In the second phase a differentiated picture of the-specific disturbance is assessed by using symptom-specific instruments of the Multiple Assessment of Psychiatric Disturbances. In a case report the diagnostic procedure is explained.     

Shaping axisymmetric shells

Assuming constant strains in thickness, the author examines the problem of shaping axisymmetric shells of elastoplastic materials. The results of computer calculations are presented.On the basis of the data obtained in [1] and assuming constant strain through the thickness, we examine the problem of shaping axisymmetric shells made of an elastoplatic material.Translated from Problemy Prochnosti, No. 4, pp. 18–24, April, 1992.     

Preparation of Poly(D,L-Lactide/Glycolide) Nanoparticles of Controlled Particle Size Distribution: Application of Experimental Designs

This study investigates the use of the solvent evaporation method for preparing acid and glycolic acid-based copolymer nanoparticles. Initially, appropriate technological and formulation factors for elaboration of polymeric particles were selected by screening. Most favourable results were obtained using polyvinyl alcohol as a dispersing agent and a high pressure homogenizer to reduce the droplet size of the emulsion initially formed. On the basis of the conclusion thus drawn, a composite rotational experimental design was employed to evaluate the joint influence of three formulation variables (phase volume ratio of the emulsion formed, polymer concentration and homogenization pressure) on the micromeritic properties of the suspension finally obtained (mean particle size, coefficient of variation and polydispersity of the particle size distribution). Analysis of variance corresponding to the experimental design, showed a significant influence of the volume phase ratio and the polymer concentration on the mean particle size and the coefficient of variation, whereas the polydispersity is also affected by the homogenization pressure. Considering this information, a 3² experimental factorial design was then selected to investigate the possible interaction between the phase volume ratio and the concentration of polyvinyl alcohol in the aqueous phase. Analysis of variance and subsequent sequencial regression analysis evidenced last hypothesis providing the way to determine the experimental conditions required to achieve a specific particle size distribution.     

Quantitative NMR spectroscopy by matrix pencil methods

The matrix pencil (MP) method, based on the singular value decomposition (SVD), is applied to quantitative NMR spectroscopy. Its relationship to other SVD-based methods is also presented. Simulations and applications are given to demonstrate the capability of superior performance.©1993 John Wiley & Sons Inc     

A mathematical model for the prediction of temperature in a dry snow layer

A mathematical model for predicting the temperature in a homogeneous layer of dry snow is presented. The model, which is physically based, is capable of predicting diurnal temperature behaviour at the snow surface and at any depth within a snow layer given the variation in a limited set of meteorological parameters over that period. A sensitivity analysis is performed to determine the important parameters in the prediction of snow surface temperatures. These are found to be consistent with simple physical reasoning.     

Mikrobielle Werkstoffzerstörung – Schadensfälle und Gegenmaßnahmen für Kunst- und Naturstoffe: Mikrobielle Zerstörung von Kunststoffen

Microbial deterioration of materials – case histories and countermeasures for plastics and organic and natural materials: Microbial deterioration of plastics Large-scale production of synthetic plastics began in the thirties. The versatility of the new materials was enhanced by new processing technologies and above all by designing special formulations tailored to the different fields of applications. Their increasing universal application was, however, also accompanied by growing records of documented microbial attack. The mechanisms of attack have largely been identified. Damage is commonly caused by surface growth, discolourations and changes of mechanical and electrical properties. National and international test standards have been developed to predict the service life of certain plastics or to evaluate the protection afforded by certain biocides. Several standard methods of test are presented and the criteria for evaluation are critically examined. Finally, the activities of the Plastics Project Group are represented, wich has carried out several international co-operative tests to evaluate the reproducibility of the results of different test methods and has worked out recommendations and improvements.