Georg Fischer

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Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six(More)
In this paper, we present the analysis, design, and implementation of an integrated power distributed amplifier (DA), fabricated in a low-cost 0.25-mum SiGe BiCMOS technology. The circuit consists of four novel inductively peaked cascode gain cells, which are capacitively coupled to the base line for power optimization and bandwidth enhancement. Due to the(More)
The diameter of columnar joints forming in cooling basalt and drying starch increases with decreasing growth rate. This observation can be reproduced with a linear-elastic three-dimensional fracture mechanics bifurcation analysis, which has been done for a periodic array of hexagonal columnar joints by considering a bifurcation mode compatible with(More)
The myrmicine genus Pheidole Westwood is revised for the smaller islands of the Southwest Indian Ocean: Comoros, Juan de Nova Island, Mauritius, Mayotte, Reunion, and the Seychelles. Descriptions and keys are provided for the thirteen species on these islands of which seven are newly described: P. decepticon sp. n., P. dodo sp. n., P. komori sp. n, P. loki(More)
This paper briefly reviews common state-of-the-art architectures of voltage regulators and their applicability to RFID. After that the design of a Low Drop-out (LDO) regulator using active resistances is presented, especially suitable for RFID applications. The chip is designed based on a 0.13 µm CMOS technology.
DICOM 3 is a very elaborate standard for the communication between medical image devices. It is published in several parts by the National Electrical Manufacturers Association (NEMA). To adequately visualize the data structure defined in parts 3, 5 and 6 of the DICOM standard, we implemented the web based Dicom Search Engine (DicoSE). It allows for querying(More)
Base station costs are dominated by the cost of radio frequency (RF) units, that is, the duplexers, the power amplifiers, and the radio cards. But Moore’s law is not applicable to these components. It only applies to the digital processing units of a base station, such as the baseband processing, line interface, and central control cards. The continuous(More)