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Muller J.,Deutsche Telekom AG | Alt F.,University of Duisburg - Essen | Schmidt A.,University of Duisburg - Essen | Michelis D.,Anhalt University of Applied Sciences
MM'10 - Proceedings of the ACM Multimedia 2010 International Conference | Year: 2010

Digital immersion is moving into public space. Interactive screens and public displays are deployed in urban environments, malls, and shop windows. Inner city areas, airports, train stations and stadiums are experiencing a transformation from traditional to digital displays enabling new forms of multimedia presentation and new user experiences. Imagine a walkway with digital displays that allows a user to immerse herself in her favorite content while moving through public space. In this paper we discuss the fundamentals for creating exciting public displays and multimedia experiences enabling new forms of engagement with digital content. Interaction in public space and with public displays can be categorized in phases, each having specific requirements. Attracting, engaging and motivating the user are central design issues that are addressed in this paper. We provide a comprehensive analysis of the design space explaining mental models and interaction modalities and we conclude a taxonomy for interactive public display from this analysis. Our analysis and the taxonomy are grounded in a large number of research projects, art installations and experience. With our contribution we aim at providing a comprehensive guide for designers and developers of interactive multimedia on public displays. © 2010 ACM.


Maass S.,TU Berlin | Wollny S.,Anhalt University of Applied Sciences | Voigt A.,Otto Von Guericke University of Magdeburg | Kraume M.,TU Berlin
Experiments in Fluids | Year: 2011

An online measurement technique for drop size distribution in stirred tank reactors is needed but has not yet been developed. Different approaches and different techniques have been published as the new standard during the last decade. Three of them (focus beam reflectance measurement, two-dimensional optical reflectance measurement techniques and a fiber optical FBR sensor) are tested, and their results are compared with trustful image analysis results from an in situ microscope. The measurement of drop sizes in liquid/liquid distribution is a major challenge for all tested measurement probes, and none provides exact results for the tested system of pure toluene/water compared to an endoscope. Not only the size analysis but also the change of the size over time gives unreasonable results. The influence of the power input on the drop size distribution was the only reasonable observation in this study. The FBR sensor was not applicable at all to the used system. While all three probes are based on laser back scattering, the general question of the usability of this principle for measuring evolving drop size distributions in liquid/liquid system is asked. The exterior smooth surface of droplets in such systems is leading to strong errors in the measurement of the size of the drops. That leads to widely divergent results. A different measurement principle should be used for online measurements of drop size distributions than laser back scattering. © 2010 Springer-Verlag.


Michelis D.,Anhalt University of Applied Sciences | Muller J.,Deutsche Telekom AG
International Journal of Human-Computer Interaction | Year: 2011

Data are presented from observations of Magical Mirrors, a set of four large public displays with gesture-based interaction installed in downtown Berlin, Germany. The displays show a mirror image of the environment in front of them and react with optical effects to the gestures of the audience. Observations of audience behavior revealed recurring behavioral patterns, like glancing at a first display while passing it, moving the arms to cause some effects, then directly approaching one of the following displays and positioning oneself in the center of the display. This was often followed by positioning oneself in the center of the other displays to explore the possibilities of the different effects, and sometimes by taking photographs or videos. From these observations a framework of interaction with gesture-based public display systems was deduced. It describes the phases of passing by a display, viewing & reacting, subtle interaction, direct interaction, multiple interactions, and follow-up actions. Quantitative data of these behavioral phases was collected by observing 660 passers-by on 2 weekend evenings. This article shows how many passers-by pass the thresholds between these phases. This "Audience Funnel" should provide a framework to encourage systematic investigation of public display systems and enable comparability between different studies. © Taylor & Francis Group, LLC.


Bergmann M.E.H.,Anhalt University of Applied Sciences | Koparal A.S.,Anadolu University | Iourtchouk T.,Anhalt University of Applied Sciences
Critical Reviews in Environmental Science and Technology | Year: 2014

Advanced oxidation processes (AOPs) are widely used and suggested for environmentally oriented applications. New combinations of single methods are described in literature. An overview about methods is given focusing on innovative papers of the previous years. At the same time, there are an increasing number of indications and evident demonstrations that the occurrence of harmful by-products is possible. Chlorate, bromate, and perchlorate belong to these by-products of inorganic nature. Corresponding cases are considered and discussed. By studying electrochemical advanced oxidation processes (EAOPs) it was found that radical generating electrodes show strong tendencies of chlorate and perchlorate formation in aqueous systems containing chloride ions. Also, bromate and perbromate formation is possible. Therefore, the authors propose these components as new inorganic criterions in environmentally oriented water treatment. A new project is described considering electrochemical drinking water disinfection in close cooperation between researchers, health and water treatment officials and cell producers. © 2014 Taylor and Francis Group, LLC.


Kirmer A.,Anhalt University of Applied Sciences | Baasch A.,Anhalt University of Applied Sciences | Tischew S.,Anhalt University of Applied Sciences
Applied Vegetation Science | Year: 2012

Questions: What are the differences in speed and pathway of vegetation development on nutrient-poor, unvegetated slopes sown with low-diversity seed mixtures of cultivars and high-diversity seed mixtures of regional species? And how is the susceptibility of the different sowing treatments to immigration events via seed rain? We compared differences in using a low-diversity seed mixture in comparison with a high-diversity seed mixture, both sown on nutrient-deficient raw soil. We assessed differences of speed and pathway of vegetation development of different variants as well as their susceptibility to immigration events via seed rain. Location: Central German Lignite Mining District. Methods: In December 2004, the trial was established in complete block design with four variants: sowing of a low-diversity seed mixture with three grass cultivars and sowing of a high-diversity seed mixture with 40 herbs and 11 grasses of local provenance, both with and without an additional mulch layer. Vegetation surveys were made between 2005 and 2010. Using generalized linear models (GLM), we tested for treatment effects on species diversity, above-ground biomass, total coverage of vegetation as well as number and coverage of target grassland species. In addition, we estimated Bray-Curtis distances between treatments using non-metric-multidimensional scaling. Results: Sowing of a high-diversity seed mixture clearly accelerated the vegetation development and led to a significantly higher biomass production in the 1st year. On both variants, the additional mulch layer facilitated the establishment of sown species and led to a higher coverage of the herb layer in the 1st year. After 6 yr, the influence of the mulch layer decreased for the benefit of the seed mixture. Despite species exchange between sites, sites sown with different seed mixtures were still dominated by different sets of species in the final year of our study. Whereas high-diversity mixtures sped up vegetation development in the direction of highly diverse semi-natural grasslands, low-diversity mixtures considerably delayed the successional progress. Conclusions: In grassland restoration in surface-mined land, high-diversity mixtures performed similar or even better than low-diversity mixtures of grass cultivars with respect to ecosystem services such as biomass production and ground cover (erosion control). An additional mulch layer considerably accelerated the vegetation development in the 1st years on both sowing variants. In contrast to sowing of low-diversity seed mixtures of grass cultivars, the use of high-diversity seed mixtures of local provenance contributes to the enhancement of local biodiversity. Although target grassland species were able to migrate into the low-diversity sites, this process is slow and only possible when appropriate seed sources are nearby. © 2011 International Association for Vegetation Science.


Conrad M.K.,Anhalt University of Applied Sciences | Tischew S.,Anhalt University of Applied Sciences
Ecological Engineering | Year: 2011

Grassland restoration on arable land is the second most implemented compensation measure in Germany to counteract impacts of infrastructural projects on nature. Most grassland restoration has been carried out using standardized commercial seed mixtures with large amounts of perennial generalists, cultivars and seeds of non-local origin. To evaluate whether this current practice is appropriate for developing regional types of species-rich mesophile grasslands, we analyzed four widely used treatments in a real-world setting (48 plots): (1) sowing a non-site-specific herb-poor mixture; (2) sowing a non-site-specific herb-enriched mixture; (3) sowing a site-specific herb-enriched mixture; and (4) spontaneous regeneration. After up to nine years, restored sites differed from target grasslands in: (1) number of species; (2) abundance and dominance of target species; and (3) dominance structure. Sown fields were dominated by sown species from the beginning. Because most differences were due to increasing cover of a small number of sown species, we found little development toward regional types of species-rich mesophile grasslands. In contrast, species composition on spontaneously regenerated sites changed to a greater degree and showed gradual development toward target grasslands. The limiting factor for successful restoration on all sites was availability of propagules. On sown sites, dominance patterns - particularly of Festuca rubra cultivars - had a negative effect on immigration and development of target species. For future restoration practice, we strongly recommend avoiding standardized commercial non-local seed mixtures. In particular, highly competitive cultivars should never be used. Even spontaneous regeneration should be preferred over standardized mixtures. However, in species-poor environments enrichment with selected species is necessary to reach target state. © 2011 Elsevier B.V.


Hildebrandt C.,Anhalt University of Applied Sciences
Journal of integrative bioinformatics | Year: 2011

Mass spectrometry is an important analytical technology for the identification of metabolites and small compounds by their exact mass. But dozens or hundreds of different compounds may have a similar mass or even the same molecule formula. Further elucidation requires tandem mass spectrometry, which provides the masses of compound fragments, but in silico fragmentation programs require substantial computational resources if applied to large numbers of candidate structures. We present and evaluate an approach to obtain candidates from a relational database which contains 28 million compounds from PubChem. A training phase associates tandem-MS peaks with corresponding fragment structures. For the candidate search, the peaks in a query spectrum are translated to fragment structures, and the candidates are retrieved and sorted by the number of matching fragment structures. In the cross validation the evaluation of the relative ranking positions (RRP) using different sizes of training sets confirms that a larger coverage of training data improves the average RRP from 0.65 to 0.72. Our approach allows downstream algorithms to process candidates in order of importance.


Deubel A.,Anhalt University of Applied Sciences | Hofmann B.,Martin Luther University of Halle Wittenberg | Orzessek D.,Anhalt University of Applied Sciences
Soil and Tillage Research | Year: 2011

Within a long-term tillage trial first laid out in Bernburg, Saxony Anhalt, Germany in 1992, the effect of tillage practice on crop yield, depth distribution and plant availability of P and K, as well as plant nutrient uptake, were investigated.With demand-orientated nitrogen fertilization and pesticide application, yields in both ploughing and conservation tillage treatments were comparable. Extensive management led to a yield decline of 11% and 17% under ploughing and conservation tillage, respectively.Soil samples showed significant P and K stratification under conservation tillage. Calcium-acetate lactate (CAL) soluble P and K concentration in 0-15. cm soil depth increased by 24% and 118%, respectively, without significant decline in deeper soil layers. This led respectively to an increase of 18% and 62%, on average, of the top soil (0-30. cm). Effects on soil pH and lime distribution were negligible. Humus content, which can positively affect nutrient availability, increased from 2.5% to 3.0% in 0-15. cm. Penetration resistance and dry density of top soil were significantly higher under conservation tillage resulting in a large decline of air capacity. This may enhance diffusion and mobilize iron-bound phosphates, but can reduce root penetration, root respiration, and microbial activity.The main reason for the large K accumulation near the soil surface is the relocation of plant residues, which contain only small amounts of phosphorus, from deeper soil layers. Despite higher P and especially K availability according to soil tests, P and K uptake and removal by harvest were equal or even tended to be less, respectively. Under present conditions, nutrients enriched in the uppermost soil layer are used insufficiently. Hence, the need for adjustments of soil sampling and the calculation of fertilization demand for reduced tillage practices should be further investigated. © 2011 Elsevier B.V.


Glaser M.,FraunhoferCenter for Silicon Photovoltaics | Lausch D.,FraunhoferCenter for Silicon Photovoltaics | Lausch D.,Anhalt University of Applied Sciences
Energy Procedia | Year: 2015

The bulk minority carrier lifetime of p-type Cz-silicon material decreases due to light induced degradation caused by the formation of recombination active BO related defects. Regeneration at elevated temperatures under carrier injection is an adequate method for transformation of these BO-related defects into a non-recombination active complex and thus for long term recovery of the minority carrier lifetime. Next to prolonged temperature treatments and carrier injection, the charge state of hydrogen is assumed to play a major role for regeneration. However, the incorporation of hydrogen and especially correctly charged hydrogen has not been proven. The physical mechanism of the regeneration process is not understood yet and still under discussion. So far no physical model explaining the regeneration process is present. For introducing a model explaining the regeneration process we investigate the influence of the concentration of charged hydrogen on the reaction kinetics on the regeneration process. By combining reaction kinetics with statistical mechanics wewill show a quantitative model for BO-regeneration considering the charge state of hydrogen. Comparing experimental and simulated values a good agreement between the experiment and the model is observed. Based on the model we are able to simulate transient defect concentrations during degradation-regenerations cycles over a wide variety of process parameters: temperature and carrier injection, giving an insight into the sophisticated process control for passivating active BO-complexes. Simulation results confirm the incorporation of fast diffusing non-charged hydrogen in the passivation of BO-related defects in cz-silicon solar cells. We conclude that the dissociation of B-H pairs and subsequent diffusion of non-charged hydrogen is the limiting process for regeneration in the material system investigated within this contribution. © 2015 The Authors.


The invention describes a method for eliminating systematical errors in one-way delay (OWD) measurements between two or more computing systems (10) in a communication network. The proposed invention extends the recent state of the art of high-precise OWD measurements, and has the advantage of elimination of the first derivative of the time difference between two computing systems (known as relative clock skew) by means of applying interpolation to one-way delay measurement results at each measurement point between tw reference points. The thus determined interpolation value corresponds to a clock offset and is deducted from the actual measurement result, thereby eliminating the relative clock skew in the measurement result set. This allows for much finer resolution of finding trends and/or over time developments in the measurement result set. The invention further concerns an apparatus to perform the method according to the invention and a corresponding computer program product.

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