Windkraft, Vögel, Lebensräume – Ergebnisse einer fünfjährigen BACI-Studie zum Einfluss von Windkraftanlagen und Habitatparametern auf Wiesenvögel

Im südlichen Ostfriesland werden seit September 2000 Langzeituntersuchungen zum Konfliktthema „Windkraft und Vögel“ durchgeführt, die auf einen Zeitraum von insgesamt sieben Jahren konzipiert sind. Es werden ausgewählte Ergebnisse aus den ersten fünf Untersuchungsjahren dargestellt. Durchgeführt wurden Bestandserfassungen von Brut- und Gastvögeln, Beobachtungen zu Verhalten und Raumnutzung, Bruterfolgskontrollen und Habitatanalysen. Die Analyse erfolgte u.a. nach dem BACI-Design (Before-After-Control-Impact, Vorher-Nachher-Untersuchung mit Referenzfläche). Die Bestandsveränderungen der untersuchten Arten verliefen unterschiedlich. Bei keiner untersuchten Art fand eine Verlagerung aus den Windparks (500 m Umkreis) in das Referenzgebiet statt. Beim Kiebitz als Brutvogel fand in einem Windpark eine signifikante Bestandsabnahme statt. Beim Vergleich von Brutpaarzahlen und Erwartungswerten, die aus den Beständen des Referenzgebietes abgeleitet wurden, fand sich beim Kiebitz als einziger Art eine signifikante Meidung des Nahbereichs der Anlagen (bis 100 m Entfernung). Beim Kiebitz als Gastvogel fand sich eine hochsignifikante Meidung bis ca. 400 m, die auch durch den Vorher-Nachher-Vergleich bestätigt wird. Raumnutzungsbeobachtungen auf Probeflächen in unterschiedlicher Entfernung zu den Anlagen ergaben hingegen keinen erkennbaren Einfluss. Verhaltensbeobachtungen beim Großen Brachvogel zeigten, dass die Anlagennähe bis ca. 50 m gemieden wurde und dass störungsanfälligere Verhaltensweisen wie Putzen oder Rasten erst ab einer Entfernung von ca. 200 m auftraten. Ein Einfluss der Windparks auf den Bruterfolg von Kiebitz und Uferschnepfe ist aus den bislang vorliegenden Daten nicht erkennbar. Univariate Habitatmodelle ergaben, dass die Nähe zu den Windkraftanlagen nur einen sehr geringen Erklärungsgehalt zur Verteilung der Reviere beiträgt. Andere Parameter, die die Habitatqualität beeinflussen, sind von wesentlich größerer Bedeutung. Multiple Habitatmodelle zeigten, dass Bereiche mit hoher Habitatqualität auch innerhalb von Windparks besiedelt werden, ein Unterschied in der Brutdichte zu Flächen gleicher Qualität im Referenzgebiet bestand nicht. Kiebitze haben jedoch auch bei dieser Analyse den 100 m-Bereich um die Anlagen signifikant gemieden. Bezüglich des Unterschiedes zwischen Brut- und Gastvögeln sowie bezüglich der Reichweite von Scheuchwirkungen besteht eine gute Übereinstimmung mit der Literatur (Übersichten in Hötker et al. 2006, Reichenbach et al. 2004). Die Untersuchungen werden noch bis Ende 2007 fortgesetzt. Schwerpunkte in den beiden letzten Untersuchungsjahren werden die Ausweitung der Bruterfolgskontrollen sowie eine Wiederholung der Habitatanalyse sein, um zeitliche Veränderungen in der Habitatqualität beurteilen und den Bestandsveränderungen der Vögel gegenüberstellen zu können.In autumn 2000, a 7-year investigation on the effects of wind power plants on breeding and staging birds was started in southern Ostfriesland. The study area consists of three sites: win farm Hinrichsfehn, wind farm Fiebing and a reference site without windmills. The analysis follows the BACI design (Before-After-Control-Impact). This paper illustrates the results of the first five study years. The changes in breeding bird densities differed between species for the period of 2001-2005, but in none species we observed a significant translocation of birds from the sites with windmills into the control site. However, in one wind farm we observed a significant decrease in Lapwing breeding numbers with time. The spatial distribution of breeding pairs in relation to the distance of windmills showed no significant differences between actual and expected values for almost all species except Lapwing. With regard to the latter scaring effects of the windmills were observed in both breeding birds (maximum distance: 100 m) and staging individuals (maximum distance: ca. 400 m). Observations on spatial use showed no reduced site use at sampling points close to the windmills as compared to the reference site. Individual-based behavioural observations on two pairs of Curlew did not demonstrate any avoidance of the wind farm, although the close surroundings of the windmills (ca. 50 m) were used less frequently. Preening and roosting behaviour patterns known to be sensitive to disturbances were produced at distances more than 200 m to the windmills. Breeding success in Lapwing and Black-tailed Godwit showed no difference between the wind farms and the reference site. Univariate habitat models indicated that habitat parameters such as vegetation height or openness of the area are more important in determining the distribution of territories than distance to the windmills. Multiple habitat models revealed the importance of habitat quality for bird densities in both, wind farms and reference site. Areas of high quality showed a high breeding bird density in all study sites. However, again the Lapwing was found to avoid the close surroundings (100 m) of a windmill. The results of the present study are in line with earlier investigations (compare Hötker et al. 2006, Reichenbach et al. 2004). In 2007 the study will be continued. In particular, main emphasis will be laid on the analysis of breeding success and the influence of changes in habitat quality on the habitat choice of meadow birds

Simulating Memristive Networks in SystemC-AMS

This chapter presents a solution for the simulation of large memristive networks with SystemC-AMS. SystemC-AMS allows simulating memristors both on analogue level and on digital level to link analogue memristive devices to digital circuits and system level specifications. We investigate the benefits and drawbacks of a SystemC-AMS simulation compared to a simulation in SPICE. We show for the example of a two-layer memristive network emulating an optical flow algorithm by the detection of moving edges that large memristive networks can be simulated with a free available SystemC-AMS simulation environment, whereas free available SPICE simulation environment fails. However, it is also shown that commercial SPICE simulators are superior against current SystemC-AMS implementations concerning the size of simulated memristive networks. However, SystemC-AMS simulations of memristive networks offer both still more flexibility and similar run times compared to commercial SPICE simulators for small-sized memristive networks. The flexibility and the powerfulness of a SystemC-AMS solution is demonstrated for a complex network that solves edge detection, filtering and detecting of moving objects. The possible run times of the memristive network are determined in the SystemC-AMS simulation environment and are compared with an optical flow algorithm on classical hardware like a CPU and a GPU

Implementing Synthetic Aperture Radar Backprojection in Chisel – A Field Report

Chisel is an emerging hardware description language which is especially popular in the RISC-V community. In this report, we evaluate its application in the field of general digital hardware design. A dedicated hardware implementation of a Synthetic Aperture Radar (SAR) processing algorithm is used as an example case for a real-world application. It is targeting a modern high performance FPGA platform. We analyze the difference in code size compared to a VHDL implementation. In contrast to related publications, we classify the code lines into several categories, providing a more detailed view. Overall, the number of lines was reduced by 74% while the amount of boilerplate code was reduced by 83%. Additionally, we report on our experience using Chisel in this practical application. We found the generative concept and the flexibility introduced by modern software paradigms superior to traditional hardware description languages. This increased productivity, especially during timing closure. However, additional programming skills not associated with classic hardware design are required to fully leverage its advantages. We recommend Chisel as a language for all hardware design tasks and expect its popularity to increase in the future

Is Internal Rotation Measurement of the Hip Useful for Ruling in Cam or Pincer Morphology in Asymptomatic Males? A Diagnostic Accuracy Study.

BACKGROUND Cam and pincer morphologies are associated with limited internal rotation. However, the routine clinical examination for hip rotation has limited reliability. A more standardized method of measuring hip rotation might increase test-retest and interobserver reliability and might be useful as a screening test to detect different hip morphologies without the need for imaging. We developed an examination chair to standardize the measurement of internal hip rotation, which improved interobserver reliability. However, the diagnostic test accuracy for this test is unknown. QUESTION/PURPOSE Is a standardized method of determining internal hip rotation using an examination chair useful in detecting cam and pincer morphology with MRI as a reference standard? METHODS A diagnostic test accuracy study was conducted in a sample of asymptomatic males. Using an examination chair with a standardized seated position, internal rotation was measured in 1080 men aged 18 to 21 years who had been conscripted for the Swiss army. The chair prevents compensatory movement by stabilizing the pelvis and the thighs with belts. The force to produce the internal rotation was standardized with a pulley system. Previous results showed that the measurements with the examination chair are similar to clinical assessment but with higher interobserver agreement. A random sample of 430 asymptomatic males was invited to undergo hip MRI. Of those, 244 White European males responded to the invitation and had a mean age of 20 ± 0.7 years and a mean internal rotation of the hip of 33° ± 8.5°. Using MRI as the reference standard, 69% (169 of 244) had a normal hip, 24% (59 of 244) a definite cam morphology (Grades 2 and 3), 3% (8 of 244) an increased acetabular depth, and 3% (8 of 244) a combination of both. One experienced radiologist graded cam morphology as follows: 0 = normal, 1 = mild, 2 = moderate, and 3 = severe. Pincer morphology was defined by increased acetabular depth (≤ 3 mm distance between the center of the femoral neck and the line connecting the anterior and posterior acetabular rims). The intraobserver agreement was substantial (weighted κ of 0.65). A receiver operating characteristic (ROC) curve was fitted, and sensitivity, specificity, and likelihood ratios were estimated for different internal rotation cutoffs. RESULTS For cam morphology, the area under the ROC curve was 0.75 (95% CI 0.67 to 0.82). Internal hip rotation of less than 20° yielded a positive likelihood ratio of 9.57 (sensitivity 0.13, specificity 0.99), and a value of 40° or more resulted in a negative likelihood ratio of 0.36 (sensitivity 0.93, specificity 0.20). The area under the curve for detecting the combination of cam and pincer morphologies was 0.87 (95% CI 0.74 to 1.0). A cutoff of 20° yielded a positive likelihood ratio of 9.03 (sensitivity 0.33, specificity 0.96). CONCLUSION This examination chair showed moderate-to-good diagnostic value to rule in hip cam morphology in White European males. However, at the extremes of the 95% confidence intervals, diagnostic performance would be poor. Nonetheless, we believe this test can contribute to identifying cam morphologies, and we hope that future, larger studies-ideally in more diverse patient populations-will seek to validate this to arrive at more precise estimates of the diagnostic performance of this test. LEVEL OF EVIDENCE Level III, diagnostic study

A Low-Power RRAM Memory Block for Embedded, Multi-Level Weight and Bias Storage in Artificial Neural Networks

Pattern recognition as a computing task is very well suited for machine learning algorithms utilizing artificial neural networks (ANNs). Computing systems using ANNs usually require some sort of data storage to store the weights and bias values for the processing elements of the individual neurons. This paper introduces a memory block using resistive memory cells (RRAM) to realize this weight and bias storage in an embedded and distributed way while also offering programming and multi-level ability. By implementing power gating, overall power consumption is decreased significantly without data loss by taking advantage of the non-volatility of the RRAM technology. Due to the versatility of the peripheral circuitry, the presented memory concept can be adapted to different applications and RRAM technologies

A Versatile, Voltage-Pulse Based Read and Programming Circuit for Multi-Level RRAM Cells

In this work, we present an integrated read and programming circuit for Resistive Random Access Memory (RRAM) cells. Since there are a lot of different RRAM technologies in research and the process variations of this new memory technology often spread over a wide range of electrical properties, the proposed circuit focuses on versatility in order to be adaptable to different cell properties. The circuit is suitable for both read and programming operations based on voltage pulses of flexible length and height. The implemented read method is based on evaluating the voltage drop over a measurement resistor and can distinguish up to eight different states, which are coded in binary, thereby realizing a digitization of the analog memory value. The circuit was fabricated in the 130 nm CMOS process line of IHP. The simulations were done using a physics-based, multi-level RRAM model. The measurement results prove the functionality of the read circuit and the programming system and demonstrate that the read system can distinguish up to eight different states with an overall resistance ratio of 7.9