Software Defined DCF77 Receiver

This paper shows the solution of time stamp software defined receiver integration into low cost com-mercial devices. The receiver is based on a general pur-pose processor and its analog to digital converter. The amplified signal from a narrow-band antenna is connected to the converter and no complicated filtration has to be used. All signal processing is digitally provided by the processor. During signal reception, the processor stays available for its main tasks and signal processing con-sumes only a small part of its computational power

Efficient Spectral Power Estimation on an Arbitrary Frequency Scale

The Fast Fourier Transform is a very efficient algorithm for the Fourier spectrum estimation, but has the limitation of a linear frequency scale spectrum, which may not be suitable for every system. For example, audio and speech analysis needs a logarithmic frequency scale due to the characteristic of a human’s ear. The Fast Fourier Transform algorithms are not able to efficiently give the desired results and modified techniques have to be used in this case. In the following text a simple technique using the Goertzel algorithm allowing the evaluation of the power spectra on an arbitrary frequency scale will be introduced. Due to its simplicity the algorithm suffers from imperfections which will be discussed and partially solved in this paper. The implementation into real systems and the impact of quantization errors appeared to be critical and have to be dealt with in special cases. The simple method dealing with the quantization error will also be introduced. Finally, the proposed method will be compared to other methods based on its computational demands and its potential speed

Numerische Untersuchungen von Parametereinflüssen des dynamischen Systems auf selbsterregte Reibungsschwingungen

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Increasing ecological multifunctionality during early plant succession

Ecological multifunctionality quantifies the functional performance of various important plant traits and increases with growing structural habitat heterogeneity, number of plant functional traits, and species richness. However, the successional changes in multifunctionality have not been traced so far. We use quantitative plant samples of 1 m2 plots from the first 6 years of initial vegetation dynamics in a German created catchment to infer the temporal changes in plant functional trait space and multifunctionality. Multifunctionality at the plot level was in all study years lower than expected from a random sample of the local pool of potential colonizers and was lowest at intermediate states of succession. In each year species containing a specific set of traits occurred with limited but focused functionality. The observed average low degree of multifunctionality contrasts with recent models predicting a tendency towards maximum multifunctionality during plant community development. However, variability in multifunctionality among plots increased during succession and the respective multifunctionality distribution among plots was increasingly right skewed indicating an excess of plots with relatively high multifunctionality. This relative excess of plots with high multifunctionality might act as an important trigger of community development paving the way for new species and functions to become established

Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem

CITATION: Biber, P. et al. 2013. Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem. Biogeosciences, 10:8283-8303, doi:10.5194/bg-10-8283-2013.The original publication is available at https://www.biogeosciences.netENGLISH ABSTRACT: We investigated surface and vegetation dynamics in the artificial initial ecosystem "Chicken Creek" (Lusatia, Germany) in the years 2006–2011 across a wide spectrum of empirical data. We scrutinized three overarching hypotheses concerning (1) the relations between initial geomorphological and substrate characteristics with surface structure and terrain properties, (2) the effects of the latter on the occurrence of grouped plant species, and (3) vegetation density effects on terrain surface change. Our data comprise and conflate annual vegetation monitoring results, biennial terrestrial laser scans (starting in 2008), annual groundwater levels, and initially measured soil characteristics. The empirical evidence mostly confirms the hypotheses, revealing statistically significant relations for several goal variables: (1) the surface structure properties, local rill density, local relief energy and terrain surface height change; (2) the cover of different plant groups (annual, herbaceous, grass-like, woody, Fabaceae), and local vegetation height; and (3) terrain surface height change showed significant time-dependent relations with a variable that proxies local plant biomass. Additionally, period specific effects (like a calendar-year optimum effect for the occurrence of Fabaceae) were proven. Further and beyond the hypotheses, our findings on the spatiotemporal dynamics during the system's early development grasp processes which generally mark the transition from a geo-hydro-system towards a bio-geo-hydro system (weakening geomorphology effects on substrate surface dynamics, while vegetation effects intensify with time), where pure geomorphology or substrate feedbacks are changing into vegetation–substrate feedback processes.https://www.biogeosciences.net/10/8283/2013/Publisher's versio

Monitoring the formation of structures and patterns during initial development of an artificial catchment

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Between biodiversity conservation and sustainable forest management - A multidisciplinary assessment of the emblematic Bialowieza Forest case

The tension between biodiversity conservation and multipurpose forest management may lead to conflicts. An internationally prominent example is the Bialowieza Forest Massif (BFM), an extensive forest complex with high levels of naturalness. We apply a systematic, multidisciplinary assessment process to review empirical evidence on different dimensions of the BFM conflict. While there is broad consensus that this forest massif is an exceptional place worth conserving and that a way forward is a zonation system combining conservation with management, exactly how this should be done has yet to be agreed upon. Our assessment shows that the key reasons for the BFM controversy go beyond the availability of knowledge on the ecological status of the BFM and include: 1) evidence stemming from different sources, which is often contradictory and prone to different interpretations; 2) knowledge gaps, particularly with regard to socio-economic drivers and beneficiaries as well as uncertainties about future trends; 3) fundamentally different values and priorities among stakeholder groups, resulting in power struggles, and an overall lack of trust. We conclude that evidence-based knowledge alone is insufficient to cope with complex conservation conflicts. While more evidence may help assess the consequences of decisions, the actual management decisions depend on different actors' worldviews, which are rooted in their professional identities and power, and their political and legal realities. This calls for conflict management through a well-organized participatory process organized and supervised by a body deemed legitimate by the groups involved