Performance analysis for geometrical attack on digital image watermarking

We present a technique for irreversible watermarking approach robust to affine transform attacks in camera, biomedical and satellite images stored in the form of monochrome bitmap images. The watermarking approach is based on image normalisation in which both watermark embedding and extraction are carried out with respect to an image normalised to meet a set of predefined moment criteria. The normalisation procedure is invariant to affine transform attacks. The result of watermarking scheme is suitable for public watermarking applications, where the original image is not available for watermark extraction. Here, direct-sequence code division multiple access approach is used to embed multibit text information in DCT and DWT transform domains. The proposed watermarking schemes are robust against various types of attacks such as Gaussian noise, shearing, scaling, rotation, flipping, affine transform, signal processing and JPEG compression. Performance analysis results are measured using image processing metrics.     

Herausforderungen der Regulierung im Bereich der Mobilkommunikation

Mobile communications represent an essential economic factor. More than 6 million mobile subscribers had been active in Austria by the end of 2000. The next mobile generation UMTS is expected to become reality in 2002. To make the operation of mobile communication systems possible and to facilitate competition, numerous regulatory measures are necessary. Important areas of regulation are the coordinated utilization of frequency spectrum, the granting of licences and interconnection of telecommunication networks. In this article the essential aspects of regulation in the area of mobile communications will be discussed.     

Nanometrology for industrial applications

The development of continuously decreasing workpiece tolerances lies in one line with the perspective of nanotechnology. To fulfil metrological demands since about 1982 new high resolution and high precision measuring devices have been developed. These are computerized instruments and the measuring results are very illustrative figures of tested specimens. But the problem of calibration in the nanometric range is still an open question which normally is done only with high uncertainty. New ideas to find a solution for the problem of sufficiently accurate calibrating will make possible that this measurement technique will be used on a broad basis also in industry.     

Übersetzung von Datenflußgraphen in optimierte Assemblerprogramme für Signalprozessoren

The synthesis of efficient programs for digital signal processors with non-homogeneous register sets is still a challenge of compiler design. In this paper, we introduce the concept of a data flow graph compiler for digital signal processors. In a first step, the data flow graph is decomposed into constrained expression trees and represented by trellis trees, which allows to apply a straight-line code generation algorithm whose complexity depends just linearly on the size of the graph. Registers are assigned by taking into account the constraints of multi-function instructions. The execution time of the resulting assembly code is minimized by exploiting instruction level parallelism and memory layout optimizations.     

Dampfkraftwerk St. Andrä Rationalisierung durch Automatisierung

A significant cost factor for the operational management of thermal power plants are personnel costs, the reduction of which was given top priority in the revitalization programme at issue for St. Andrä 2 Thermal Power Plant during the years 1993–1997. Modern control and intrumentation, allowing for a high degree of automation, was an inevitable measure. The first part of this article illustrates the entire course of the project with appertaining objectives, as for instance, general considerations and explanations. The main part describes the actual realization of automation with the TELEPERM M process control system from Siemens.     

Die Karbonatschmelzen-Brennstoffzelle — Grundlagen für den Kraftwerkseinsatz

Conventional energy transforming techniques aiming at power production are based on the Carnot process, in which process heat is supplied by burning fossil combustibles. In the fuel cell, power is generated directly by the fuel, i.e. chemically bound energy, by means of a reversible electrochemical change. As for the stationary use in the energy industry, the Molten Carbonate Fuel Cell (MCFC) pertaining to the high temperature fuel cells is particularly adequate, as the operating temperature in the range of 650 °C allows for an optimal waste heat utilization. In this paper, the bases of MCFCs for the use in power plants is illustrated by the example of the 1 MW pilot project of Kawagoe (Japan) being under construction.     

Spracherkennung mit Hidden Control Neural Networks

Hidden control neural networks (HCN networks) are suitable for a variety of pattern recognition techniques. The speech recognizer described here is built for speaker-independent single-word recognition and is intended to implement user interfaces to control devices via simple word-commands. To evaluate the speech recognizer, it has been applied to minimum pairs. Within a minimum pair two words differ only in a single phoneme. It was achieved to increase the recognition rate while taking those periods of time especially into account, that are found to contain the relevant difference.     

Drahtlose Abfrage von Oberflächenwellen-Identifikationsmarken und Meßwertwandlern

We describe wireless readout of 3 different species of passive surface acoustic wave (SAW) identification tags. and sensors which all are connected to a small antenna for reception of the interrogation signal and transmission of the delayed sensor response.

1. Following the ringing out of SAW resonators using a phase locked loop (PLL) over several microseconds, their resonance-(?Eigne”-)frequencies are determined.
2. The time between some response impulses in a SAW delay line, caused by acoustical reflectors in different distances, accurately is measured by 3 different signal integrating methods.
3. Amplitude variations of the response impulse, due to variations of a capacitance externally connected to the SAW delay line are evaluated.

All methods are used for wireless readout of fixed and adjustable identification codes and sensor measurands e.g. temperature, pressure, mechanical force, torque, deformation, electrical voltage etc.     

Das Laserlöten als Kontaktierungsverfahren für Mikrosensoren

Miniaturized sensor elements (e.g. temperature sensors, flow sensors, gas sensors, humidity sensors, etc.) are frequently carried only by their lead-in wires. Laser soldering provides a possibility to attach relatively thick wires to thin film metallizations on a sensor chip. This paper first discusses theoretical aspects of the dynamic wetting process and the leaching phenomenon. Subsequently, it describes the influence of the substrate material on the soldering parameters (laser power and pulse duration) and analyzes the soldering process by temperature measurements using thin film thermocouples integrated in the soldering pad.