A framework for efficiently mining the organisational perspective of business processes

Process mining aims at discovering processes by extracting knowledge from event logs. Such knowledge may refer to different business process perspectives. The organisational perspective deals, among other things, with the assignment of human resources to process activities. Information about the resources that are involved in process activities can be mined from event logs in order to discover resource assignment conditions, which is valuable for process analysis and redesign. Prior process mining approaches in this context present one of the following issues: (i) they are limited to discovering a restricted set of resource assignment conditions; (ii) they do not aim at providing efficient solutions; or (iii) the discovered process models are difficult to read due to the number of assignment conditions included. In this paper we address these problems and develop an efficient and effective process mining framework that provides extensive support for the discovery of patterns related to resource assignment. The framework is validated in terms of performance and applicability

Mining team compositions for collaborative work in business processes

Process mining aims at discovering processes by extracting knowledge about their different perspectives from event logs. The resource perspective (or organisational perspective) deals, among others, with the assignment of resources to process activities. Mining in relation to this perspective aims to extract rules on resource assignments for the process activities. Prior research in this area is limited by the assumption that only one resource is responsible for each process activity, and hence, collaborative activities are disregarded. In this paper, we leverage this assumption by developing a process mining approach that is able to discover team compositions for collaborative process activities from event logs. We evaluate our novel mining approach in terms of computational performance and practical applicability

Mining Resource Assignments and Teamwork Compositions from Process Logs

Process mining aims at discovering processes by extracting knowledge from event logs. Such knowledge may refer to different business process perspectives. The organisational perspective deals, among other things, with the assignment of human resources to process activities. Information about the resources that are involved in process activities can be mined from event logs in order to discover resource assignment conditions. This is valuable for process analysis and redesign. Prior process mining approaches in this context present one of the following issues: (i) they are limited to discovering a restricted set of resource assignment conditions; (ii) they are not fully efficient; (iii) the discovered process models are difficult to read due to the high number of assignment conditions included; or (iv) they are limited by the assumption that only one resource is responsible for each process activity and hence, collaborative activities are disregarded. To overcome these issues, we present an integrated process mining framework that provides extensive support for the discovery of resource assignment and teamwork patterns

Deep Subduction in Earth history: Seeking for traces in the sedimentary record

Die durch das Absinken von kalter und dichter Lithosphäre angetriebene horizontale Bewegung von tektonischen Platten auf globalem Maßstab ist bekannt als Plattentektonik, ein Hauptprozess der den Austausch zwischen Erdoberfläche und Erdmantel ermöglicht. Demnach hat die Plattentektonik einen starken Einfluss auf geochemische Kreisläufe, die Konvektion des Erdmantels, Wachstumsraten kontinentaler Kruste, sowie thermische und tektonische Regime. Wenn auch unterschiedliche Meinungen vorherrschen, so deuten zahlreiche Hinweise auf die Existenz plattentektonischer Prozesse seit dem Übergang vom Archaikum zum Proterozoikum, vor allem solche die von detritischen Zirkonen abgeleitet wurden. Wie sich jedoch die Plattentektonik von ihrem Beginn zum modernen Regime entwickelt hat, d.h. ab wann kalte und tiefe Subduktion charakterisiert durch Niedrig-Temperatur/Hoch-Druck und Ultrahoch-Druck (UHP) Metamorphose existierte, ist eine stark kontrovers diskutierte Thematik. Insbesondere die Abwesenheit von Blauschiefern und UHP-Gesteinen vom pre-neoproterozoischem Rekord ist ein Hauptargument der Befürworter eines späten Beginns der modernen Plattentektonik. Auf der Suche nach Hinweisen für moderne Plattentektonik in der frühen Erdgeschichte sind wir stark beschränkt durch das lückenhaft erhaltene Archiv von Kristallingesteinen, dessen Repräsentativität für das jeweilig betrachte Zeitintervall zweifelhaft ist, sowie das Nichtvorhandensein geeigneter Methoden um das sedimentäre Archiv auf moderne Subduktionsprozesse zu ergründen. Vor allem detritische Minerale haben das grundsätzliche Potenzial Zeitscheiben der Erdgeschichte mit höherer Repräsentativität zu beproben. Kürzlich wurde eine neuartige Methode etabliert, welche durch die Analyse von Mineral-Einschlüssen in detritischem Granat ermöglicht, erodiertes Material von UHP-Gesteinen aufzuspüren, mit Coesit-Einschlüssen als Indikator. Potentiell schafft dieser Ansatz einen neuen Zugang, um die frühe Erdgeschichte auf Hinweise für tiefe Subduktion zu untersuchen. Allerdings wurde dessen Funktionalität bisher nur für ein kleines Einzugsgebiet in der Western Gneiss Region von Norwegen demonstriert, was die Klärung einiger fundamentaler Fragen bedarf bevor die Methode auf große Gebiete sowie fossile Sedimente und Sedimentgesteine angewendet werden kann. Diese Dissertation präsentiert die Anwendung des neuartigen Ansatzes auf zwei phanerozoische Gebirge und demonstriert: (i) Mineral-Einschlüsse in detritischem Granat sind befähigt UHP-Gesteine aufzuspüren, auch in großen Einzugsgebieten von Flüssen; (ii) zusätzlich zu Coesit, hinterlassen auch Diamant-führende Gesteine ihre Spuren im Detritus in Form von Diamant-Einschlüssen in Granat; und (iii) liefert die Kombination von Mineral-Einschlüssen und Granatchemie neue Einblicke in den UHP-Gesteinszyklus der untersuchten Gebiete. Dies beinhaltet Beweise für eine räumlich deutlich weitreichenderes Auftreten von UHP-Gesteinen im zentralen Erzgebirge von Deutschland als zuvor angenommen, sowie die Einbeziehung von sowohl mafischen als auch felsischen Lithologien. Auch die felsischen Nebengesteine wurden mit einbezogen, die nach bisheriger Meinung nie das Coesit-Stabilitätsfeld erreichten. Während der Exhumierung von UHP-Bedingungen wurden diese teilweise aufgeschmolzen und re-equilibrierten. Daraus wird geschlossen, dass die vorherig beschriebenen UHP-Linsen und die umgebenden Nebengesteine gemeinsam als weitgehend zusammenhängende Platte subduziert wurden, was weitreichende Implikationen für das Verständnis der Dichte-Entwicklung von kontinentaler Kruste während der Subduktion bis zu oder der Exhumierung von UHP-Bedingungen hat. Die Funde von detritischem Coesit-führendem Granat aus dem metamorphen D’Entrecasteaux-Komplex von Papua Neu-Guinea, in Kombination mit co-existierenden Graphit-Einschlüssen, Granatchemie, Schmelzeinschlüssen und elastischer Geothermobarometrie, enthüllen erstmals einen vollständigen UHP-Zyklus. Dieser beinhaltet ein metasedimentäres Ausganggestein gebildet an der Erdoberfläche, welches tief subduziert wurde bis zu UHP-Bedingungen unter Bildung der Coesit-führenden Granate, darauffolgende Exhumierung bis zur Erdoberfläche unter zwischenzeitlich ansteigender Temperatur, wo es schließlich erodiert, transportiert, und die Granate als Strandseife abgelagert wurden. Die große Anzahl an Granaten vom Erzgebirge mit sowohl monomineralischen Coesit-Einschlüssen als auch solchen die teilweise zu Quarz umgewandelt wurden, ermöglichten zudem eine detaillierte Studie der Erhaltungsfaktoren von Coesit. Es wird gezeigt: (iv) eine kleine Einschlussgröße von <9 µm und eine geringe Anzahl pro Granat-Wirtsmineral-Korn reduziert stark das Bruchverhalten des Granats durch sich bildende Überdrücke in den Einschlüssen und somit werden die Einschlüsse von den externen Bedingungen und Fluiden abgeschirmt, was wiederum die monomineralische Erhaltung ermöglicht; (v) bimineralisch erhaltene Coesit/Quarz-Einschlüsse treten durch Bruch des Wirts-Granats spät während der Exhumierung mit Fluiden in Kontakt bei Temperaturen ~330 °C; und (vi) die heterogene Korngrößenverteilung von detritischem Coesit-führenden Granat kann auf die Einschlusshäufigkeit pro Korn zurückgeführt werden. Demnach haben sowohl Granate die von mafischen als auch solche die von felsische Ausgangsgesteinen stammen ursprünglich eine große Kristallgröße, jedoch weisen mafische Granate eine geringe Anzahl an Einschlüssen auf, wodurch diese kaum zerbrechen, während felsische Granate eine variable Anzahl aufzeigen und Einschluss-reiche Kristalle bevorzugt zu kleinen Fragmenten zerbrechen, welches zu einer Anreicherung im feineren Korngrößenbereich führt. Des Weiteren zeigt die Dissertation mehrere methodische Weiterentwicklungen auf, einschließlich: (vii) die höchste Effizienz von aufzuwendender Analysezeit im Vergleich zum gewonnen Informationsgehalt für die Korngrößenfraktion 250–500 µm; (viii) die effiziente Möglichkeit einer geochemischen Vorauswahl und Selektion einzelner Granatkörner basierend auf einem neu entwickelten Diskriminierungs-Modell unter Verwendung einer großen Datenbank und einem Algorithmus für maschinelles Lernen; und (ix) eine alternative Möglichkeit zur Reduktion der vom Benutzer aufzuwendenden Analysezeit durch hyperspektrale Raman Bildgebungsmethoden. Insgesamt führt dies zu der Hauptschlussfolgerung, dass die Analyse von Mineral-Einschlüssen in detritischem Granat ein solides und effizientes Konzept repräsentiert, um die Verbreitung und Eigenschaften von UHP-Gesteinen zur Zeit dessen Freilegung an der Erdoberfläche und Generierung sowie Ablagerung von Sedimenten zu erfassen. Dieses Konzept hat großes Potenzial die ungeklärte Problematik anlässlich des Agierens moderner Plattentektonik auf globalem Maßstab in pre-neoproterozoischer Zeit von einer neuen Perspektive zu ergründen.The global-scale horizontal movement of tectonic plates driven by the sinking of cold and dense lithosphere, known as plate tectonics, is a major process linking the Earth’s surface with mantle. Thus, plate tectonics strongly affect geochemical cycles, mantle convection, crustal growth rates, as well as thermal and tectonic regimes. Numerous hints, particularly from the detrital zircon record, indicate that plate tectonics operate since at least the Archean–Proterozoic transition, although opposing views persist. How plate tectonics evolved on a global-scale from the onset to the modern-style regime, which includes cold and deep subduction defined by low-temperature/high-pressure and ultrahigh-pressure (UHP) metamorphism, is a highly controversial and hotly debated topic in Earth Sciences. Particularly the lack of blueschists and UHP rocks from the pre-Neoproterozoic record represents a key argument for a late onset of modern-style plate tectonics. A main limitation in the search for modern-style plate tectonic regimes in deep time is the fragmentarily preserved crystalline rock record that may or may not be representative for the respective time interval, and the virtual absence of techniques to make use of the sedimentary record that would enable to more representatively investigate subduction regimes through time on a global scale. Recently, a novel method was introduced to trace the erosion of UHP metamorphic rocks by screening mineral inclusion assemblages of detrital garnet for the presence of coesite, and thus potentially opening new avenues to seek for the operation of deep subduction in deep time. However, these findings are restricted to a small catchment in the Western Gneiss Region of Norway, raising some fundamental question to be addressed before applying the concept to ancient sediments. This thesis applies the novel detrital approach to two Phanerozoic orogens, demonstrating that: (i) mineral inclusions in detrital garnet are capable to record UHP rock occurrences, also for regional river catchments; (ii) besides coesite, diamond-grade rocks effectively transfer UHP signatures to the sedimentary record in the form of diamond inclusions; and (iii) combining the information from mineral inclusions and garnet chemistry provides new insights regarding the UHP rock cycle of the study areas. For the central Saxonian Erzgebirge of Germany, this includes evidence for a much wider extent of UHP metamorphism than previously assumed and the involvement of mafic as well as felsic rocks in the UHP cycle. This includes felsic country-rock gneisses that underwent partial melting and re-equilibration during exhumation and have previously been supposed to have reached peak conditions below the coesite stability field. It is concluded that previously described UHP lenses and the surrounding country rocks were subducted as a largely coherent slab, which has important implications to understand the buoyancy development of the subducting/exhuming continental crust of UHP terranes. For the D’Entrecasteaux metamorphic complex of Papua New Guinea, detrital garnet chemistry, coesite co-existing with graphite inclusions, melt inclusions, and elastic geothermobarometry reveal, for the first time, a complete UHP rock cycle starting with a metasedimentary protolith that originated from the Earth surface, deep subduction to UHP conditions, exhumation under increasing temperature conditions, and erosion to form the studied beach placer. In addition, for the Erzgebirge, the large number of monomineralic coesite inclusions and coesite inclusions that partially transformed to quartz enabled a detailed investigation of preservation factors, showing that: (iv) a small size <9 µm and a low frequency of coesite inclusions favors the garnet host to stay intact in spite of inclusion overpressures developing during exhumation, and thus coesite inclusions are shielded from external conditions and fluids, which enables their monomineralic preservation; (v) bimineralic coesite/quartz inclusions ruptured their host garnet at a late stage during exhumation at temperatures of ~330 °C; and (vi) the heterogeneous grain-size distribution of detrital coesite-bearing garnet can be explained by inclusion frequency. Thereby, mafic and felsic UHP garnets are initially large, but mafic garnet contains a low number of inclusions resulting in minor disintegration and enrichment in the coarse fraction, while felsic garnet contains variable amounts of inclusions, whereby coesite-poor grains are enriched in the coarse fraction and coesite-rich grains extensively disintegrated into smaller fragments resulting in an enrichment in the fine fraction. Furthermore, the thesis presents several technical advancements, which include that: (vii) the 250–500 µm grain-size fraction is most efficient in terms of analytical time to invest compared to information value to gain; (viii) based on a newly developed discrimination scheme using a large database and a machine-learning algorithm, garnet chemistry represents an efficient tool to pre-screen and pre-select grains ahead of the time-consuming inclusion analysis; and (ix) hyperspectral Raman imaging provides an alternative to reduce the user-assisted analytical time. In main conclusion, analyzing mineral inclusions in detrital garnet represents a robust and efficient approach to capture the distribution and characteristics of UHP rocks exposed at the surface at the time of sediment generation and deposition. The methodological framework is mature and has a high potential to tackle the issue whether modern-style plate tectonics operated on a global scale in pre-Neoproterozoic times.2022-12-1

Garnet major-element composition as an indicator of host-rock type: a machine learning approach using the random forest classifier

The major-element chemical composition of garnet provides valuable petrogenetic information, particularly in metamorphic rocks. When facing detrital garnet, information about the bulk-rock composition and mineral paragenesis of the initial garnet-bearing host-rock is absent. This prevents the application of chemical thermo-barometric techniques and calls for quantitative empirical approaches. Here we present a garnet host-rock discrimination scheme that is based on a random forest machine-learning algorithm trained on a large dataset of 13,615 chemical analyses of garnet that covers a wide variety of garnet-bearing lithologies. Considering the out-of-bag error, the scheme correctly predicts the original garnet host-rock in (i) > 95% concerning the setting, that is either mantle, metamorphic, igneous, or metasomatic; (ii) > 84% concerning the metamorphic facies, that is either blueschist/greenschist, amphibolite, granulite, or eclogite/ultrahigh-pressure; and (iii) > 93% concerning the host-rock bulk composition, that is either intermediate–felsic/metasedimentary, mafic, ultramafic, alkaline, or calc–silicate. The wide coverage of potential host rocks, the detailed prediction classes, the high discrimination rates, and the successfully tested real-case applications demonstrate that the introduced scheme overcomes many issues related to previous schemes. This highlights the potential of transferring the applied discrimination strategy to the broad range of detrital minerals beyond garnet. For easy and quick usage, a freely accessible web app is provided that guides the user in five steps from garnet composition to prediction results including data visualization.deutsche forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Georg-August-Universität Göttingen (1018)http://134.76.17.86:443/garnetRF

A framework for efficiently mining the organisational perspective of business processes

Process mining aims at discovering processes by extracting knowledge from event logs. Such knowledge may refer to different business process perspectives. The organisational perspective deals, among other things, with the assignment of human resources to process activities. Information about the resources that are involved in process activities can be mined from event logs in order to discover resource assignment conditions, which is valuable for process analysis and redesign. Prior process mining approaches in this context present one of the following issues: (i) they are limited to discovering a restricted set of resource assignment conditions; (ii) they do not aim at providing efficient solutions; or (iii) the discovered process models are difficult to read due to the number of assignment conditions included. In this paper we address these problems and develop an efficient and effective process mining framework that provides extensive support for the discovery of patterns related to resource assignment. The framework is validated in terms of performance and applicability.European Union 1502/89304-01/2012 (KpPQ)Austrian Research Promotion Agency (FFG) 845638 (SHAPE

Inherited Grain‐Size Distributions: Effect on Heavy‐Mineral Assemblages in Modern and Ancient Sediments

AbstractHeavy‐mineral suites are used widely in sandstone provenance and are key when connecting source and sink. When characterizing provenance related signatures, it is essential to understand the different factors that may influence a particular heavy‐mineral assemblage for example, chemical weathering or diagenetic processes. Hydrodynamics, causing size‐density sorting, exert major control on the distribution of heavy minerals. Here, we highlight the effect of grain‐size inheritance, essentially the absence of certain grain sizes within a specific heavy‐mineral species, on two distinct types of sediments. Modern deposits from a high‐energy beach in NW Denmark give an analog for heavily reworked sediment, primarily controlled by hydrodynamic processes. In contrast, three Palaeogene turbidite successions in the Eastern Alps were sampled, presenting a more complex history that includes diagenesis. All samples were processed for their heavy‐mineral compositions using Raman spectroscopy, and several techniques applied to determine the effect of grain‐size inheritance. Results show that (a) even within the hydrodynamically well‐sorted beach and placer deposits, evidence of grain‐size inheritance is apparent, and (b) turbidites of variable heavy‐mineral composition show strong effects of grain‐size inheritance for several mineral species. Moreover, considerable intersample contrasts within single turbidite beds are observed. We enforce the importance of understanding grain‐size inheritance, as well as other processes effecting size‐density relations in clastic sediment that go well beyond purely hydrodynamic control of intrasample heavy‐mineral variability.Plain Language Summary: Heavy minerals are commonly found within sediments and sedimentary rocks and can tell us from which source regions the sediment may have originated. However, it is important to understand that the type, size, and abundance of particular heavy minerals can change depending on factors such as environmental conditions. The size, shape, and density of the heavy minerals also limits when and where they will settle and/or stay. A lack of big or small grains of a particular heavy mineral in the source rocks dictates the size of the minerals deposited; this is known as grain‐size inheritance. Using both ancient and modern sediment, we are looking for traces of grain‐size inheritance. Surprisingly, in all samples investigated we noted effects of grain‐size inheritance, for different heavy‐mineral types. The modern beach sediments, as expected, show more impact of hydraulic processes, but inherited grain sizes are still apparent. Within the ancient examples, grain‐size inheritance is more obvious, with further variations even observed between samples collected from the same area. Having identified this control on grain size, we can highlight the importance of understanding this effect when analyzing clastic sediments.Key Points: Understanding factors that can modify a heavy‐mineral assemblage is fundamental in provenance analysis Heavy minerals of two distinct sedimentary environments were analyzed and compared to their “ideal” hydrodynamically sorted compositions Several heavy‐mineral species of modern and ancient settings were identified to be influenced by grain‐size inheritance from the source https://doi.org/10.25625/MVUIJ

Mining the Organisational Perspective in Agile Business Processes

Agile processes depend on human resources, decisions and expert knowledge, and they are especially versatile and comprise rather complex scenarios. Declarative, i.e., rule-based, process models are wellsuited for modelling these processes. Although there are several mining techniques to discover such declarative process models from event logs, they put less emphasis on the organisational perspective, which speci es how resources are involved in the activities. As a consequence, the resulting models do not specify who should execute which task and with which constraint (like separation of duties) in mind. In this paper, we propose a process mining approach to discover resource-aware, declarative process models. Our speci c contribution is the extraction of complex rules for resource assignment that integrate the control- ow and organisational perspectives. Our experiments demonstrate the expressiveness of the mined rules with a reference to the Work ow Resource Patterns and a real-world use case.Austrian Research Promotion Agency (FFG) 845638 (SHAPE