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Predictive Process Monitoring setzt sich als Hilfsmittel zur Unterstützung der betrieblichen Abläufe in Unternehmen immer mehr durch Die meisten heute verfüg-baren Softwareanwendungen erfordern jedoch ein umfangreiches technisches Know-how des Betreibers und sind daher für die meisten realen Szenarien nicht geeignet. Daher wird in dieser Arbeit eine prototypische Implementierung eines Predictive Process Monitoring Dashboards in Form einer Webanwendung vorgestellt. Das System basiert auf dem von Bartmann et al. (2021) vorgestellten PPM-Camunda-Plugin und ermöglicht es dem Benutzer, auf einfache Weise Metriken, Visualisierungen zur Darstellung dieser Metriken und Dashboards, in denen die Visualisierungen angeordnet werden können, zu erstellen. Ein Usability-Test mit Testnutzern mit unterschiedlichen Computerkenntnissen wird durchgeführt, um die Benutzerfreundlichkeit der Anwendung zu bestätigen.
The diversity within amphibian communities in cultivated areas in Rwanda and within two selected, taxonomically challenging groups, the genera Ptychadena and Hyperolius, were investigated in this thesis. The amphibian community of an agricultural wetland near Butare in southern Rwanda comprised 15 anuran species. Rarefaction and jackknife analyses corroborated that the complete current species richness of the assemblage had been recorded, and the results of acoustic niche analysis suggested species saturation of the community. Surveys at many other Rwandan localities showed that the species recorded in Butare are widespread in cultivated and pristine wetlands. The species were readily distinguishable using morphological, bioacoustic, and molecular (DNA barcoding) features, but only eight of the 15 species could be assigned unambiguously to nominal species. The remaining represented undescribed or currently unrecognized taxa, including three species of Hyperolius, two Phrynobatrachus species, one Ptychadena species, and one species of Amietia. The diversity of the Ridged Frogs in Rwanda was investigated in two studies (Chapters III and IV). Three species of Ptychadena were recorded in wetlands in the catchment of the Nile. They can be distinguished by morphological characters (morphometrics and qualitative features) as well as by their advertisement calls and genetics. The Rwandan species of the P. mascareniensis group was shown to differ from the topotypic population as well as from other genetic lineages in sub-Saharan Africa and an old available name, P. nilotica, was resurrected from synonymy for this lineage. Two further Ptychadena species were identified among voucher specimens from Rwanda deposited in the collection of the RMCA, P. chrysogaster and P. uzungwensis. Morphologically they can be unambiguously distinguished from each other and the three other Rwandan species. A key based on qualitative morphological characters was developed, which allows unequivocal identification of specimens of all species that have been recorded from Rwanda. DNA was isolated from a Rwandan voucher specimen of P. chrysogaster, and the genetic analysis corroborated the species" distinct status.
A species of Hyperolius collected in the Nyungwe National Park was compared to all other Rwandan species of the genus and to morphologically or genetically similar species from neighbouring countries. Its distinct taxonomic status was justified by morphological, bioacoustic, and molecular evidence and it was described as a new species, H. jackie. A species of the H. nasutus group collected at agricultural sites in Rwanda was described as a new species in the course of a revision of the species of the Hyperolius nasutus group. The group was shown to consist of 15 distinct species which can be distinguished from each other genetically, bioacoustically, and morphologically.
The aerial performance, i.e. parachuting, of the Disc-fingered Reed Frog, Hyperolius discodactylus, was described. It represents a novel observation of a behaviour that has been known from a number of Southeast Asian and Neotropical frog species. Parachuting frogs, including H. discodactylus, exhibit certain morphological characteristics and, while airborne, assume a distinct posture which is best-suited for maneuvering in the air. Another study on the species addressed the validity of the taxon H. alticola which had been considered either a synonym of H. discodactylus or a distinct species. Type material of both taxa was re-examined and the status of H. alticola reassessed using morphological data from historic and new collections, call recordings, and molecular data from animals collected on recent expeditions. A northern and a southern genetic clade were identified, a divide that is weakly supported by diverging morphology of the vouchers from the respective localities. No distinction in advertisement call features could be recovered to support this split and both genetic and morphological differences between the two geographic clades are marginal and not always congruent and more likely reflect population-level variation. Therefore it was concluded that H. alticola is not a valid taxon and should be treated as a synonym of H. discodactylus.
On the recognition of human activities and the evaluation of its imitation by robotic systems
(2023)
This thesis addresses the problem of action recognition through the analysis of human motion and the benchmarking of its imitation by robotic systems.
For our action recognition related approaches, we focus on presenting approaches that generalize well across different sensor modalities. We transform multivariate signal streams from various sensors to a common image representation. The action recognition problem on sequential multivariate signal streams can then be reduced to an image classification task for which we utilize recent advances in machine learning. We demonstrate the broad applicability of our approaches formulated as a supervised classification task for action recognition, a semi-supervised classification task for one-shot action recognition, modality fusion and temporal action segmentation.
For action classification, we use an EfficientNet Convolutional Neural Network (CNN) model to classify the image representations of various data modalities. Further, we present approaches for filtering and the fusion of various modalities on a representation level. We extend the approach to be applicable for semi-supervised classification and train a metric-learning model that encodes action similarity. During training, the encoder optimizes the distances in embedding space for self-, positive- and negative-pair similarities. The resulting encoder allows estimating action similarity by calculating distances in embedding space. At training time, no action classes from the test set are used.
Graph Convolutional Network (GCN) generalized the concept of CNNs to non-Euclidean data structures and showed great success for action recognition directly operating on spatio-temporal sequences like skeleton sequences. GCNs have recently shown state-of-the-art performance for skeleton-based action recognition but are currently widely neglected as the foundation for the fusion of various sensor modalities. We propose incorporating additional modalities, like inertial measurements or RGB features, into a skeleton-graph, by proposing fusion on two different dimensionality levels. On a channel dimension, modalities are fused by introducing additional node attributes. On a spatial dimension, additional nodes are incorporated into the skeleton-graph.
Transformer models showed excellent performance in the analysis of sequential data. We formulate the temporal action segmentation task as an object detection task and use a detection transformer model on our proposed motion image representations. Experiments for our action recognition related approaches are executed on large-scale publicly available datasets. Our approaches for action recognition for various modalities, action recognition by fusion of various modalities, and one-shot action recognition demonstrate state-of-the-art results on some datasets.
Finally, we present a hybrid imitation learning benchmark. The benchmark consists of a dataset, metrics, and a simulator integration. The dataset contains RGB-D image sequences of humans performing movements and executing manipulation tasks, as well as the corresponding ground truth. The RGB-D camera is calibrated against a motion-capturing system, and the resulting sequences serve as input for imitation learning approaches. The resulting policy is then executed in the simulated environment on different robots. We propose two metrics to assess the quality of the imitation. The trajectory metric gives insights into how close the execution was to the demonstration. The effect metric describes how close the final state was reached according to the demonstration. The Simitate benchmark can improve the comparability of imitation learning approaches.
In den letzten Jahrzehnten wurde deutlich, dass die Welt mit einer beispiellosen, vom Menschen verursachten Biodiversitätskrise konfrontiert ist. Eine der am stärksten bedrohten Artengruppen stellen dabei die Amphibien dar, so gelten laut IUCN 41% der Amphibienarten als gefährdet. Jedoch können selbst bei Arten die als "least concern" klassifiziert sind Populationsrückgänge auf lokaler Ebene beobachtet werden. Mit einer veränderten Landnutzung und dem Einsatz von Pestiziden sind zwei der Hauptursachen für diese Gefährdung direkt mit intensiver Landwirtschaft verbunden. Daher ist das Wissen um die Situation von Amphibien in der Agrarlandschaft von entscheidender Bedeutung für Schutzmaßnahmen. In der vorliegenden Arbeit wurden Amphibienpopulationen in der durch Weinbau geprägten Gegend um Landau in der Pfalz (Deutschland) im Hinblick auf Lebensraumnutzung, Pestizidexposition, biometrische Merkmale sowie der Alters- und genetischer Populationsstruktur untersucht. Da Agrarflächen oft zur Fragmentierung von Landschaften führen, ging ich der Frage nach ob dies auch auf Weinberge zutrifft und ob eingesetzte Pestizide zur Fragmentierung beitragen, ob also eine chemische Landschaftsfragmentierung vorliegt. Durch die Telemetrierung von Erdkröten (Bufo bufo) konnte ich zeigen, dass diese Art direkt in Weinbergen gefunden werden kann, diese aber generell eher meidet. Die Analyse der genetischen Struktur von Grasfröschen (Rana temporaria) ergab, dass Weinberge als Barriere für Amphibien anzusehen sind. Um herauszufinden, ob Pestizide zu der daraus resultierenden Landschaftsfragmentierung beitragen, führte ich einen Wahlversuch im Labor durch, bei dem ich ein Vermeidungsverhalten gegenüber kontaminierten Böden fand, was zu einer chemischen Landschaftsfragmentierung führen könnte. Durch die Kombination von Telemetriedaten mit Daten über Pestizidanwendungen von lokalen Winzern konnte ich zeigen, dass ein großer Teil der Erdkröten mit Pestiziden in Kontakt kommt. Außerdem konnte gezeigt werden, dass sich die Agrarlandschaft und hier wahrscheinlich Pestizide negativ auf die Fortpflanzungsfähigkeit von Erdkröten auswirkt. Bei der Untersuchung von Fadenmolchen (Lissotriton helveticus) stellte ich fest, dass adulte Molche aus Gewässern in der Agrarlandschaft kleiner sind als Individuen aus Gewässern im Wald. Da kein Unterschied in der Altersstruktur festgestellt werden konnte, könnten diese Größenunterschiede auf suboptimale Bedingungen für Larven und/oder Jungtiere hindeuten, wenngleich Gewässer in der Agrarlandschaft geeignete Lebensräume für adulte Teichmolche sein könnten. Ich komme zu dem Schluss, dass die beste Maßnahme zum Schutz von Amphibien in der Agrarlandschaft eine heterogene Kulturlandschaft mit einem Mosaik aus verschiedenen Lebensräumen wäre, die ohne oder zumindest mit weniger Pestiziden auskommt. Grüne Korridore zwischen Populationen und Teillebensräumen würden es wandernden Individuen ermöglichen, landwirtschaftliche und damit pestizidbelastete Flächen zu vermeiden. Dies würde das Risiko der Pestizidexposition von Amphibien verringern und gleichzeitig die Fragmentierung der Landschaft und damit die Isolation von Populationen verhindern.
Ponds in agricultural landscapes are often used by amphibians as breeding habitat. However, the characteristics of agricultural ponds and especially the surrounding area are usually said to be suboptimal for many amphibian species. Using suboptimal habitats might allow a species’ survival and reproduction, but can have negative consequences at the individual and population level. In the present study, we investigated Palmate Newt (Lissotriton helveticus) populations from an intensive wine-growing region in southern Germany and compared them with populations located in a nearby forested area in terms of biometric traits, age and genetic structure. By analyzing over 900 adult newts from 11 ponds, we could show that newts reproducing in forest ponds were larger than newts reproducing in agricultural ponds. We did not find differences in the newt age and growth rate between habitat types. Therefore, differences in the body size of newts might already existed in larvae and/or juveniles, what might be related to a lower habitat quality for larvae and/or juveniles in the agricultural landscape. Body mass, body condition and sexual dimorphic traits (length of the caudal filament and max. height of the tail) correlated with body size, but no additional effect of the habitat type was found. The analysis of microsatellites revealed a higher genetic diversity in forest ponds. However, no clear sign of inbreeding was observed in any agricultural population, suggesting some degree of gene flow between them. We conclude, that agricultural ponds can be suitable habitats for the Palmate Newt and that conservation effort should aim to preserve them. The observed effects on body size indicate the need to increase the quality of the aquatic and terrestrial habitat for early life stages of this newt species in agricultural landscapes.
This thesis was motivated by the need to advance the knowledge on the variability and dynamics of energy fluxes in lakes and reservoirs, as well as about the physical processes that regulate the fluxes at both the air and water side of the air-water interface.
In the first part, I re-examine how mechanical energy, resulting from its major source – the vertical wind energy flux - distributes into the various types of water motions, including turbulent flows and surface and internal waves. Although only a small fraction of the wind energy flux from the atmosphere is transferred to the water, it is crucial for physical, biogeochemical and ecological processes in lentic ecosystems. Based on extensive air- and water-side measurements collected at two small water bodies (< 10 km2), we estimated the energy fluxes and energy content in surface and in internal waves. Overall, the estimated energy fluxes and energy content agree well with results reported for larger water bodies, suggesting that the energetics driving the water motions in enclosed basins is similar, independently of the basin size. Our findings highlight the importance of the surface waves that receive the largest fraction of the wind energy flux, which strongly nonlinearly increases for wind speeds exceeding 3 m s-1. We found that the existing parameterization of the wave height as a function of wind speed and fetch length did not reproduce the measured wave amplitude in lakes. On average, the highest energy content was observed in basin-scale internal waves, together with high-frequency internal waves exhibiting seasonal variability and varies among the aquatic systems. During our analysis, we discovered the diurnal variability of the energy dissipation rates in the studied lake, suggesting biogenic turbulence generation, which appears to be a widespread phenomenon in lakes and reservoirs.
In the second part of the thesis, I addressed current knowledge gaps related to the bulk transfer coefficients (also known as the drag coefficient, the Stanton number and the Dalton number), which are of a particular importance for the bulk estimation of the surface turbulent fluxes of momentum, sensible and latent heat in the atmospheric boundary layer. Their inaccurate representation may lead to significant errors in flux estimates, affecting, for example, the weather and climate predictions or estimations of the near-surface current velocities in lake hydrodynamic models. Although the bulk transfer coefficients have been extensively studied over the past several decades (mainly in marine and large-lake environments), there has been no systematic analysis of measurements obtained at lakes of different size. A significant increase of the transfer coefficients at low wind speeds (< 3 m s-1) has been observed in several studies, but, to date, it has remained unexplained. We evaluated
the bulk transfer coefficients using flux measurements from 31 lakes and reservoirs. The estimates were generally within the range reported in previous studies for large lakes and oceans. All transfer coefficients increased substantially at low wind speeds, which was found to be associated with the presence of gusts and capillary waves (except the Dalton number). We found that the Stanton number is systematically higher than the Dalton number. This challenges the assumption made in the Bowen-ratio method, which is widely used for estimating evaporation rates from micrometeorological measurements. We found that the variability of the transfer coefficients among the lakes could be associated with lake surface area. In flux parameterizations at lake surfaces, it is recommended to consider variations in the drag coefficient and the Stanton number due to wind gustiness and capillary wave roughness while the Dalton number could be considered as constant at all wind speeds.
In the third part of the thesis, I address the key drivers of the near-surface turbulence that control the gas exchange in a large regulated river. As all inland waters, rivers are an important natural source of greenhouse gases. The effects of the widespread alteration and regulation of river flow for human demands on gas exchange is largely unknown. In particular, the near-surface turbulence in regulated rivers has been rarely measured and its drivers have not been identified. While in lakes and reservoirs, near-surface turbulence is mainly related to atmospheric forcing, in shallow rivers and streams it is generated by bottom friction of the gravity-forced flow. The studied large regulated river represents a transition between these two cases. Atmospheric forcing and gravity were the dominant drivers of the near-surface turbulence for a similar fraction of the measurement period. Based on validated scalings, we derived a simple model for estimating the relative contributions of wind and bottom friction to near-surface turbulence in lotic ecosystems with different flow depths. Large diel variability in the near-surface energy dissipation rates due to flow regulation leads to the same variability in gas exchange. This suggests that estimates of gas fluxes from rivers are biased by measurements performed predominantly during daytime.
In addition, the novelty in all the analyses described above is the use of the turbulent surface fluxes measured directly by the eddy-covariance technique – at the moment of writing, the most advanced method. Overall, this thesis is of a potential interest for a broad range of scientific disciplines, including limnology, micrometeorology and open channel hydraulics.
Binnengewässer spielen eine aktive Rolle im globalen Kohlenstoffkreislauf. Sie nehmen Kohlenstoff von stromaufwärts gelegenen Landmassen auf und transportieren ihn stromabwärts, bis er schließlich den Ozean erreicht. Auf diesem Weg sind vielfältige Prozesse zu beobachten, die zu einer (dauerhaften) Rückhaltung des Kohlenstoffs durch Einlagerung in Sedimenten sowie zu direkter Emission in die Atmosphäre führen. Es ist dringend notwendig diese Kohlenstoffflüsse und ihre anthropogene Veränderung zu quantifizieren. In diesem Zusammenhang muss die Aufmerksamkeit auf ein weit verbreitetes Merkmal von Gewässern gerichtet werden: ihre teilweise Austrocknung. Dies führt dazu, dass ehemals überschwemmte Sedimente in direkten Kontakt mit der Atmosphäre gelangen, genannt „dry inland waters“. Ein Merkmal der „dry inland waters“ sind überproportional hohe Kohlendioxid (CO2)-Emissionen. Diese Erkenntnis beruhte jedoch bisher auf lokalen Fallstudien, und es fehlt an Wissen über die globale Verbreitung und die grundlegenden Mechanismen dieser Emissionen. Vor diesem Hintergrund zielt diese Arbeit darauf ab, das Ausmaß und die Mechanismen der Kohlenstoffemissionen der „dry inland waters“ auf globaler und lokaler Ebene besser zu verstehen und die Auswirkungen von „dry inland waters“ auf den globalen Kohlenstoffkreislauf zu bewerten. Die spezifischen Forschungsfragen dieser Arbeit lauteten: (1) Wie fügen sich gasförmige Kohlenstoffemissionen von „dry inland waters“ in den globalen Kohlenstoffkreislauf und in die globalen Treibhausgasbudgets ein? (2) Welche Auswirkungen haben saisonale und langfristige Austrocknung auf den Kohlenstoffkreislauf von Gewässern? Diese Arbeit hat gezeigt, dass „dry inland waters“im globalen Maßstab unverhältnismäßig große Mengen an CO2 emittieren und dass diese Emissionen in allen Ökosystemen vergleichbaren Mechanismen folgen. Die Quantifizierung der globalen Wasserstandsschwankungen in Stauseen und die globale Berechnung der Kohlenstoffflüsse legen nahe, dass Stauseen mehr Kohlenstoff freisetzen als sie in den Sedimenten einlagern, was das derzeitige Verständnis von Stauseen als Nettokohlenstoffsenken in Frage stellt. Auf lokaler Ebene hat diese Arbeit gezeigt, dass sowohl die heterogenen Emissionsmuster verschiedener typischer Uferbereiche als auch die saisonalen Schwankungen der Kohlenstoffemissionen aus der „drawdown area“ berücksichtigt werden müssen. Darüber hinaus hat diese Arbeit gezeigt, dass die Remobilisierung von Kohlenstoff aus den Sedimenten bei dauerhafter Austrocknung von Gewässern die beobachteten Emissionsraten erklären kann, was die Hypothese einer positiven Rückkopplung zwischen Klimawandel und der Austrocknung von Gewässern unterstützt. Insgesamt unterstreicht die vorliegende Arbeit die Bedeutung der Emissionen aus trockenen Gewässerbereichen für den globalen Kohlenstoffkreislauf von Gewässern.
This study was conducted in Nyungwe National Park (NNP); a biodiversity hotspot Mountain rainforest of high conservation importance in Central Africa, but with little knowledge of its insect communities including butterflies, good indicators of climate change, and forest ecosystem health. The study aimed at availing baseline data on butterfly species diversity and distribution in NNP, for future use in monitoring climate change-driven shifts and the effects of forest fragmentation on the biodiversity of Nyungwe. Butterflies were collected seasonally using fruit-baited traps and hand nets along elevational transects spanning from 1700 m up to 2950 m of altitude. Two hundred forty-two species including 28 endemics to the Albertine Rift and 18 potential local climate change indicators were documented. Species richness and abundance declined with increasing elevation and higher seasonal occurrence was observed during the dry season. This was the first study on the spatial and temporal distribution of butterflies in NNP and further studies could be conducted to add more species and allow a depth understanding of the ecology of Nyungwe butterflies.
These proceedings contain 6 papers presented at the 1st Interdisciplinary Conference on Gamification and Entrepreneurship (StartPlay) 2022. The conference was held at the University of Koblenz-Landau in Koblenz, Germany, on August 05-06, 2022.
Game-Balance Simulation as a Tool for the Evaluation of
Systematically Designed Gamification Strategies
Authors: David Kessing, Manuel Löwer
A Canvas Framework for Gameful Design Concepts
Authors: Max Höllen, Thomas Voit
Gamified Sustainable Entrepreneurship Education –
A digital Educational Escape Room for economy classes
in German High Schools
Authors: Jürgen Frentz, Marie Tuchscherer, Claudia Wiepcke
Playing Positive Psychology: The Development of a
Positive-Psychological Board Game for Team Building
Authors: Leonie Kloep, Anna-Lena Helten, Corinna Peifer
Gamification Design for Goal Activation and Goal Striving
in Digital Marketing and Innovation Management
Authors: Jenny V. Bittner, Christian Wellmann
Gamification of Assembly Routines: Planned User Study
Evaluating a Level System with Customized Feedback
Elements
Authors: Jessica Ulmer, Sebastian Braun, Jörg Wollert