Asymptotically optimal quantizers for detection of i.i.d

The asymptotic probability of error for quantization in maximum-likelihood tests is analyzed. The authors assume quantizers with large numbers of levels generated from a companding function. A theorem that relates the companding function to the asymptotic probability of error is proved. The companding function is then optimized     

Vergleich von Nachweisverfahren für Stutzen in Zylinderschalen unter Innendruck und äußeren Lasten

Various methods for the verification of nozzles in cylindrical shells are described and the results of an example are compared. The example is carried out according to DIN EN 13445‐3, Sect. 16.5, in which the maximum permissible loads from internal pressure, axial force as well as moments in the longitudinal and circumferential direction are calculated. The results are compared with finite element computations performed with a 3D shell model, both with linear‐elastic material behavior and as limit‐load analyzes with ideal‐elastic ideal‐plastic material behavior.     

Asymptotic results for maximum likelihood estimation with an arrayof sensors

In many cases, the maximum likelihood (ML) estimator is consistent and asymptotically normal with covariance equal to the inverse of the Fisher's information matrix. It does not follow, though, that the covariance of the ML estimator approaches the Cramer-Rao lower bound as the sample size increases. However, it is possible to draw such a conclusion for the adaptive array problem in which direction of arrival and signal magnitude are being estimated. Proofs of w-asymptotic efficiency, which comes with a convergence-of-moments condition, and strong consistency (almost-sure convergence) of the ML estimator are given. Strong consistency is also proved for a popular quasi-ML estimator     

Large deviation rate calculations for nonlinear detectors inGaussian noise

An asymptotic analysis based on large deviation theory is presented for three representative nonlinear receivers operating in the presence of Gaussian noise, namely radiometers, differential phase shift keying, and memoryless detectors. En route to the results an extension to the Toeplitz distribution theorem is proved. This extension provides the key to obtaining closed-form expressions for the exponential rate of decrease of the probability of error for the first two detector structures. The solution to the rate constant problem for the memoryless detector is then shown to be given by the solution to a certain nonlinear Hammerstein integral equation. Several examples are presented     

Investigation of the behaviour of cracks in a dissimilar weld

Using the finite-element method the behaviour of an axial and a circumferential crack in a dissimilar weld of the ferritic steel X20 CrMoV 12 1 and the austenitic X10 NiCrAITi 32 20 has been investigated. Stresses due to internal pressure and stresses resulting from temperature cycling due to different thermal expansion coefficients have been calculated. The circumferential crack located within the austenite in the region of maximum longitudinal stress is loaded at its deepest point by a stress intensity factor of 473 The axial crack is loaded up to a stress intensity of 325 N mm^−3/2 not at its deepest point, but within the X20 CrMoV 12 1. The resulting crack growth for both cracks has been estimated and compared with a component test with artificial defects in a dissimilar weld undergoing similar loadings.     

Eine Bruchmechanikprobe und Belastungsvorrichtung zur Bestimmung von Rißzähigkeiten bei überlagerter Normal- und Schubbeanspruchung

A fracture mechanics specimen and loading device for the determination of fracture toughness under superimposed normal and shear modes of loading A simple as well as compact fracture mechanics specimen and a surprisingly uncomplicated loading device is suggested for the determination of fracture toughnesses under loading mode I, loading mode II and mixed loading mode. With this loading device the different loading modes can be applied to the specimen by means of a simple tensile test.     

Installing windows in composite thermal insulation systems / Fenstermontage in Wärmedämm‐Verbundsystemen

According to the German Association for Composite Thermal Insulation Systems, about 780 million m² of composite thermal insulation systems (ETICS) have up to now been installed in both existing and new buildings in Germany ? a trend that is set to continue. Correct window installation in ETICS with a permanent and functional connection to the building fabric requires architects, engineers and contractors to be familiar with the special details of this external wall system [1], [2]. However, experience from expert witness reporting has shown that this is frequently not so and that eliminating any defects subsequently is only possible at great expense.     

Fluorescence histochemistry of the surface epithelium and stroma in the rhesus monkey ovary

The surface epithelium and stromal elements in the ovary of the rhesus monkey were studied with a variety of fluorescence-histochemical procedures to determine the relative distribution of specific chemical moieties. The surface (germinal) epithelium displayed high levels of cytoplasmic RNA and specifically intense fluorescence with methods that demonstrate basic, SH and SS groups of protein. The underlying basement membrane demonstrated an intense reaction when fluorochromed with hydroxynaphthoic acid hydrazide directed toward side-chain carboxyl groups of protein. The fluorescence pattern displayed by the underlying connective tissue was heterogeneous and related to its anatomical localization. It is suggested that this heterogeneity reflects specific, but as yet undefined, chemical differences in the fibrous elements of the ovary.