Prefix Imputation of Orphan Events in Event Stream Processing

In the context of process mining, event logs consist of process instances called cases. Conformance checking is a process mining task that inspects whether a log file is conformant with an existing process model. This inspection is additionally quantifying the conformance in an explainable manner. Online conformance checking processes streaming event logs by having precise insights into the running cases and timely mitigating non-conformance, if any. State-of-the-art online conformance checking approaches bound the memory by either delimiting storage of the events per case or limiting the number of cases to a specific window width. The former technique still requires unbounded memory as the number of cases to store is unlimited, while the latter technique forgets running, not yet concluded, cases to conform to the limited window width. Consequently, the processing system may later encounter events that represent some intermediate activity as per the process model and for which the relevant case has been forgotten, to be referred to as orphan events. The naïve approach to cope with an orphan event is to either neglect its relevant case for conformance checking or treat it as an altogether new case. However, this might result in misleading process insights, for instance, overestimated non-conformance. In order to bound memory yet effectively incorporate the orphan events into processing, we propose an imputation of missing-prefix approach for such orphan events. Our approach utilizes the existing process model for imputing the missing prefix. Furthermore, we leverage the case storage management to increase the accuracy of the prefix prediction. We propose a systematic forgetting mechanism that distinguishes and forgets the cases that can be reliably regenerated as prefix upon receipt of their future orphan event. We evaluate the efficacy of our proposed approach through multiple experiments with synthetic and three real event logs while simulating a streaming setting. Our approach achieves considerably higher realistic conformance statistics than the state of the art while requiring the same storage.</p

Conformance checking of process event streams with constraints on data retention

Conformance checking (CC) techniques in process mining determine the conformity of cases, by means of their event sequences, with respect to a business process model. Online conformance checking (OCC) techniques perform such analysis for cases in event streams. Cases in streams may essentially not be concluded. Therefore, OCC techniques usually neglect the memory limitation and store all the observed cases whether seemingly concluded or unconcluded. Such indefinite storage of cases is inconsistent with the spirit of privacy regulations, such as GDPR, which advocate the retention of minimal data for a definite period of time. Catering to the aforementioned constraints, we propose two classes of novel approaches that partially or fully forget cases but can still properly estimate the conformance of their future events. All our proposed approaches bound the number of cases in memory and forget those in excess of the defined limit on the basis of prudent forgetting criteria. One class of these proposed approaches retains a meaningful summary of the forgotten events in order to resume the CC of their cases in the future, while the other class leverages classification for this purpose. We highlight the effectiveness of all our proposed approaches compared to a state of the art OCC technique lacking any forgetting mechanism through experiments using real-life as well as synthetic event data under a streaming setting. Our approaches substantially reduce the amount of data required to be retained while minimally impacting the accuracy of the conformance statistics

Measuring the impact of COVID-19 on hospital care pathways

Care pathways in hospitals around the world reported significant disruption during the recent COVID-19 pandemic but measuring the actual impact is more problematic. Process mining can be useful for hospital management to measure the conformance of real-life care to what might be considered normal operations. In this study, we aim to demonstrate that process mining can be used to investigate process changes associated with complex disruptive events. We studied perturbations to accident and emergency (A &E) and maternity pathways in a UK public hospital during the COVID-19 pandemic. Co-incidentally the hospital had implemented a Command Centre approach for patient-flow management affording an opportunity to study both the planned improvement and the disruption due to the pandemic. Our study proposes and demonstrates a method for measuring and investigating the impact of such planned and unplanned disruptions affecting hospital care pathways. We found that during the pandemic, both A &E and maternity pathways had measurable reductions in the mean length of stay and a measurable drop in the percentage of pathways conforming to normative models. There were no distinctive patterns of monthly mean values of length of stay nor conformance throughout the phases of the installation of the hospital’s new Command Centre approach. Due to a deficit in the available A &E data, the findings for A &E pathways could not be interpreted

Research Paper: Process Mining and Synthetic Health Data: Reflections and Lessons Learnt

Analysing the treatment pathways in real-world health data can provide valuable insight for clinicians and decision-makers. However, the procedures for acquiring real-world data for research can be restrictive, time-consuming and risks disclosing identifiable information. Synthetic data might enable representative analysis without direct access to sensitive data. In the first part of our paper, we propose an approach for grading synthetic data for process analysis based on its fidelity to relationships found in real-world data. In the second part, we apply our grading approach by assessing cancer patient pathways in a synthetic healthcare dataset (The Simulacrum provided by the English National Cancer Registration and Analysis Service) using process mining. Visualisations of the patient pathways within the synthetic data appear plausible, showing relationships between events confirmed in the underlying non-synthetic data. Data quality issues are also present within the synthetic data which reflect real-world problems and artefacts from the synthetic dataset’s creation. Process mining of synthetic data in healthcare is an emerging field with novel challenges. We conclude that researchers should be aware of the risks when extrapolating results produced from research on synthetic data to real-world scenarios and assess findings with analysts who are able to view the underlying data

Controls on mineralisation in the Cadeby formation (lower magnesian linestone)

Several distinct low grade assemblages of baryte and/or base metal sulphides are present within the Cadeby Formation at outcrop', each assemblage being restricted to a certain geographical area and, s betimes, one stratigraphic horizon. Although some occurrences are fault controlled, the majority have a stratigraphic control related to both carbonate facies and diagenetic history. High energy carbonate facies and bryozoan patch reefs are devoid of mineralization, whereas lower energy facies may host stratiform sulphides and baryte. Mineralization is also related to former displacive evaporites, either by direct replacement or by precipitation in voids resultant from evaporite dissolution. Diagenesis is complex with different mechanisms of dolomitization, evaporite replacement and dedolomitization; mineralization is related to early diagenesis at some localities. The spatial occurrences of mineralized localities suggests an underlying structural control linked with basement tectonics. Although isotope determinations indicate most sulphur has derived from interbedded evaporites, metals may have been introduced through basement fractures, be derived from within the formation or related to Kupferschiefer/Marl Slate mineralization. No common origin for the Permian mineral occurrences therefore exists

A Pilot Study of Wichita Indian Archeology and Ethnohistory

In 1965 several anthropologists drew up plans for a one-year pilot study of the archeology and ethnohistory of the Wichita Indian tribes. After financial support had been generously provided by the National Science Foundation, the proposed research was carried out. This is a report on the results of that study. The pilot study was designed to: a) obtain a body of field data from the components of the Spanish Fort sites, the largest and best=documented of the historic Wichita sites in the Red River area; b) make test excavations at several other sites in order that a problem=oriented program of future research can be accurately planned; c) attempt to locate, by field reconnaissance, sites that relate to the Wichita occupation of the southern plains on both the historic and prehistoric time levels; d) make a survey of available ethnohistorical data in order (1) to compile a bibliography of documentary materials relevant to Wichita ethnohistory, (2) to make a detailed study of documents that relate specifically to the excavations being carried out at Spanish Fort and at the sites being tested, (3) to seek information that might lead to the field locations of other Wichita sites, and (4) to appraise those sources best suited for more extended examination. The co-investigators of the project were Tyler Bastian of the Museum of the Great Plains, Robert E. Bell of The University of Oklahoma, Edward B. Jelks of Southern Methodist University, and W.W. Newcomb of the Texas Memorial Museum at The University of Texas. Bastian supervised the archeological field work in Oklahoma under the direction of Bell. Jelks directed the archeological work in Texas. Newcomb directed the ethnohistorical research. Marvin E. Tong of the Museum of the Great Plains served the project as general coordinator. The main part of the ethnohistorical study consisted of a thorough search of the archives at The University of Texas for documents relating to Wichita ethnohistory. The archeological work included extensive excavations at the Longest Site in Oklahoma and at the Upper Tucker and Coyote Sites in Texas. More limited excavations were carried out at the Glass and Gas Plant Sites in Texas. Several other archeological sites were visited but not excavated beyond a test pit or two: the Devils Canyon and Wilson Springs Sites in Oklahoma, and the Gilbert, Stone, Vinson, and Womack Sites in Texas. An effort was also made to locate several sites in Oklahoma and Texas which were reported in historical documents but which had not been located in the field. After the library research and the archeological field work had been completed, a brief, general report could have been prepared to satisfy our contractual obligation to the National Science Foundation. It was felt, however, that the data which had been collected would be of interest to archeologists and ethnohistorians and, if possible, it should be made available to them in some detail without delay. Consequently, a series of descriptive papers was prepared instead of a summary report. Those papers are presented here

The Toarcian Posidonia Shale at Salem (North Alpine Foreland Basin; South Germany): hydrocarbon potential and paleogeography

The Posidonia Shale in the basement of the North Alpine Foreland Basin of southwestern Germany represents an important archive for environmental changes during the Toarcian oceanic anoxic event and the associated carbon isotope excursion (T-CIE). It is also an important hydrocarbon source rock. In the Salem borehole, the Posidonia Shale is ~ 10 m thick. The lower 7.5 m (1763.5–1756.0 m) of the Posidonian Shale and the uppermost part of the underlying Amaltheenton Formation were cored and studied using a total of 62 samples. Rock–Eval, palynological, maceral, biomarker and carbon isotope data were collected to assess variations in environmental conditions and to quantify the source rock potential. In contrast to most other Toarcian sections in southwest Germany, TOC contents are high in sediments deposited during the T-CIE, but reach a peak in post-CIE sediments. Biomarker ratios suggest that this reflects strong oxygen-depletion during the T-CIE (elegantulum to lower elegans subzones), but also during the falciferum Subzone, which is also reflected by a prolonged dinoflagellate cyst blackout. While sediments of the tenuicostatum Zone to the elegans Subzone are thinner than in neighbouring sections (e.g., Dotternhausen), sediments of the falciferum Subzone are unusually thick, suggesting that increased subsidence might have contributed to anoxia. The T-CIE interval is very thin (0.75 m). δ$^{13}$C values of n-alkanes show that the maximum negative isotope shift predates the strongest basin restriction during the T-CIE and that the carbon isotope shift is recorded earlier for aquatic than for terrigenous organisms. In Salem, the Posidonia Shale is thermally mature and highly oil-prone. The residual source petroleum potential is about 0.8 tHC/m$^{2}$. Graphical Abstrac

\u27Code\u27 and the Slow Erosion of Privacy

The notion of software code replacing legal code as a mechanism to control human behavior-- code as law --is often illustrated with examples in intellectual property and freedom of speech. This Article examines the neglected issue of the impact of code as law on privacy. To what extent is privacy-related code being used, either to undermine or to enhance privacy? On the basis of cases in the domains of law enforcement, national security, E-government, and commerce, it is concluded that technology rarely incorporates specific privacy-related norms. At the same time, however, technology very often does have clear effects on privacy, as it affects the reasonable expectation of privacy. Technology usually makes privacy violations easier. Particularly information technology is much more a technology of control than it is a technology of freedom. Privacy-enhancing technologies (PETs) have yet to be implemented on any serious scale. The consequent eroding effect of technology on privacy is a slow, hardly perceptible process. If one is to stop this almost natural process, a concerted effort is called for, possibly in the form of privacy impact assessments, enhanced control mechanisms, and awareness-raising

Aluminium: Flexible and Light, Towards Sustainable Cities

Aluminium: Flexible and Light is book four in the Towards Sustainable Cities series. It demonstrates the flexibility of aluminium in the many production and fabrication processes that can be used to transform and deploy this light and durable metal, from casting, roll forming, extruding, spinning and direct digital printing. Fabrication processes include: laser and water jet cutting, welding, friction stir welding. The role of aluminium in creating thermally efficient yet highly transparent glazing systems is discussed. Key case studies demonstrating and quantifying the carbon savings arising from the specification of aluminium based architecture include: Kielder Probes by sixteen*(makers), Guy’s Hospital Tower by Penoyre & Prasad, dlr Lexicon by Carr Cotter & Naessens, i360 by Marks Barfield Architects and the Large Hadron Collider at CERN. Included in this book is the first complete history of the use of aluminium in bridge construction from 1933 to the second decade of the twenty-first century

\u27Code\u27 and the Slow Erosion of Privacy

The notion of software code replacing legal code as a mechanism to control human behavior-- code as law --is often illustrated with examples in intellectual property and freedom of speech. This Article examines the neglected issue of the impact of code as law on privacy. To what extent is privacy-related code being used, either to undermine or to enhance privacy? On the basis of cases in the domains of law enforcement, national security, E-government, and commerce, it is concluded that technology rarely incorporates specific privacy-related norms. At the same time, however, technology very often does have clear effects on privacy, as it affects the reasonable expectation of privacy. Technology usually makes privacy violations easier. Particularly information technology is much more a technology of control than it is a technology of freedom. Privacy-enhancing technologies (PETs) have yet to be implemented on any serious scale. The consequent eroding effect of technology on privacy is a slow, hardly perceptible process. If one is to stop this almost natural process, a concerted effort is called for, possibly in the form of privacy impact assessments, enhanced control mechanisms, and awareness-raising